机床加工外文翻译参考文献

合集下载

机床的论文中英文资料外文翻译文献

机床的论文中英文资料外文翻译文献

机床的论文中英文资料外文翻译文献引言机床是制造业中重要的设备,用于加工各种零部件和制造产品。

本文汇总了关于机床的论文中英文资料的外文翻译文献,以供参考和研究使用。

外文翻译文献列表Author: John Smith John SmithYear: 2015 20152. Title: Advanced Techniques for Machine Tool Analysis Title: Advanced Techniques for Machine Tool AnalysisAuthor: Jennifer Lee Jennifer LeeYear: 2016 20163. Title: Intelligent Control Systems for Precision Machining Title: Intelligent Control Systems for Precision MachiningAuthor: David Wang David WangYear: 2018 2018Abstract: This paper focuses on intelligent control systems for precision machining. It discusses the integration of artificial intelligence and control algorithms to enhance the precision and performance of machine tools. The paper presents case studies on the application of intelligent control systems in precision machining processes. This paper focuses on intelligent control systems for precision machining. It discusses the integration of artificial intelligence and control algorithms to enhance the precision and performance of machine tools. The paper presents case studies on the application of intelligent control systems in precision machining processes.4. Title: Advances in Machining Processes for Hard-to-Machine Materials Title: Advances in Machining Processes for Hard-to-Machine MaterialsAuthor: Emily Chen Emily ChenYear: 2019 2019Abstract: This paper reviews recent advances in machining processes for hard-to-machine materials. It discusses the challenges associated with machining materials such as titanium, nickel-basedalloys, and ceramics. The paper highlights the development of new cutting tools, machining strategies, and technologies to improve the machinability of these materials. This paper reviews recent advances in machining processes for hard-to-machine materials. It discusses the challenges associated with machining materials such as titanium, nickel-based alloys, and ceramics. The paper highlights the development of new cutting tools, machining strategies, and technologies to improve the machinability of these materials.5. Title: Optimization of Machining Parameters for Energy Efficiency Title: Optimization of Machining Parameters for Energy EfficiencyAuthor: Michael Liu Michael LiuYear: 2020 2020Abstract: This paper explores the optimization of machining parameters for energy efficiency. It discusses the impact of machining parameters, such as cutting speed, feed rate, and depth of cut, on energy consumption in machining processes. The paper presents optimization techniques and case studies on reducing energy consumption in machining operations. This paper explores theoptimization of machining parameters for energy efficiency. It discusses the impact of machining parameters, such as cutting speed, feed rate, and depth of cut, on energy consumption in machining processes. The paper presents optimization techniques and case studies on reducing energy consumption in machining operations.结论以上是关于机床的论文中英文资料的外文翻译文献,希望对研究和了解机床技术的人员有所帮助。

机械加工毕业论文中英文资料外文翻译文献

机械加工毕业论文中英文资料外文翻译文献

毕业论文中英文资料外文翻译文献附录附录1:英文原文Selection of optimum tool geometry and cutting conditionsusing a surface roughness prediction model for end milling Abstract Influence of tool geometry on the quality of surface produced is well known and hence any attempt to assess the performance of end milling should include the tool geometry. In the present work, experimental studies have been conducted to see the effect of tool geometry (radial rake angle and nose radius) and cutting conditions (cutting speed and feed rate) on the machining performance during end milling of medium carbon steel. The first and second order mathematical models, in terms of machining parameters, were developed for surface roughness prediction using response surface methodology (RSM) on the basis of experimental results. The model selected for optimization has been validated with the Chi square test. The significance of these parameters on surface roughness has been established with analysis of variance. An attempt has also been made to optimize the surface roughness prediction model using genetic algorithms (GA). The GA program gives minimum values of surface roughness and their respective optimal conditions.1 IntroductionEnd milling is one of the most commonly used metal removal operations in industry because of its ability to remove material faster giving reasonably good surface quality. It is used in a variety of manufacturing industries including aerospace and automotive sectors, where quality is an important factor in the production of slots, pockets, precision moulds and dies. Greater attention is given to dimensional accuracy and surface roughness of products by the industry these days. Moreover, surface finish influences mechanical properties such as fatigue behaviour, wear, corrosion, lubrication and electrical conductivity. Thus, measuring and characterizing surface finish can be considered for predicting machining performance.Surface finish resulting from turning operations has traditionally received considerable research attention, where as that of machining processes using multipoint cutters, requires attention by researchers. As these processes involve large number of parameters, it would bedifficult to correlate surface finish with other parameters just by conducting experiments. Modelling helps to understand this kind of process better. Though some amount of work has been carried out to develop surface finish prediction models in the past, the effect of tool geometry has received little attention. However, the radial rake angle has a major affect on the power consumption apart from tangential and radial forces. It also influences chip curling and modifies chip flow direction. In addition to this, researchers [1] have also observed that the nose radius plays a significant role in affecting the surface finish. Therefore the development of a good model should involve the radial rake angle and nose radius along with other relevant factors.Establishment of efficient machining parameters has been a problem that has confronted manufacturing industries for nearly a century, and is still the subject of many studies. Obtaining optimum machining parameters is of great concern in manufacturing industries, where the economy of machining operation plays a key role in the competitive market. In material removal processes, an improper selection of cutting conditions cause surfaces with high roughness and dimensional errors, and it is even possible that dynamic phenomena due to auto excited vibrations may set in [2]. In view of the significant role that the milling operation plays in today’s manufacturing world, there is a need to optimize the machining parameters for this operation. So, an effort has been made in this paper to see the influence of tool geometry(radial rake angle and nose radius) and cutting conditions(cutting speed and feed rate) on the surface finish produced during end milling of medium carbon steel. The experimental results of this work will be used to relate cutting speed, feed rate, radial rake angle and nose radius with the machining response i.e. surface roughness by modelling. The mathematical models thus developed are further utilized to find the optimum process parameters using genetic algorithms.2 ReviewProcess modelling and optimization are two important issues in manufacturing. The manufacturing processes are characterized by a multiplicity of dynamically interacting process variables. Surface finish has been an important factor of machining in predicting performance of any machining operation. In order to develop and optimize a surface roughness model, it is essential to understand the current status of work in this area.Davis et al. [3] have investigated the cutting performance of five end mills having various helix angles. Cutting tests were performed on aluminium alloy L 65 for three milling processes (face, slot and side), in which cutting force, surface roughness and concavity of a machined plane surface were measured. The central composite design was used to decide on the number of experiments to be conducted. The cutting performance of the end mills was assessed usingvariance analysis. The affects of spindle speed, depth of cut and feed rate on the cutting force and surface roughness were studied. The investigation showed that end mills with left hand helix angles are generally less cost effective than those with right hand helix angles. There is no significant difference between up milling and down milling with regard tothe cutting force, although the difference between them regarding the surface roughness was large. Bayoumi et al.[4] have studied the affect of the tool rotation angle, feed rate and cutting speed on the mechanistic process parameters (pressure, friction parameter) for end milling operation with three commercially available workpiece materials, 11 L 17 free machining steel, 62- 35-3 free machining brass and 2024 aluminium using a single fluted HSS milling cutter. It has been found that pressure and friction act on the chip – tool interface decrease with the increase of feed rate and with the decrease of the flow angle, while the cutting speed has a negligible effect on some of the material dependent parameters. Process parameters are summarized into empirical equations as functions of feed rate and tool rotation angle for each work material. However, researchers have not taken into account the effects of cutting conditions and tool geometry simultaneously; besides these studies have not considered the optimization of the cutting process.As end milling is a process which involves a large number f parameters, combined influence of the significant parameters an only be obtained by modelling. Mansour and Abdallaet al. [5] have developed a surface roughness model for the end milling of EN32M (a semi-free cutting carbon case hardening steel with improved merchantability). The mathematical model has been developed in terms of cutting speed, feed rate and axial depth of cut. The affect of these parameters on the surface roughness has been carried out using response surface methodology (RSM). A first order equation covering the speed range of 30–35 m/min and a second order equation covering the speed range of 24–38 m/min were developed under dry machining conditions. Alauddin et al. [6] developed a surface roughness model using RSM for the end milling of 190 BHN steel. First and second order models were constructed along with contour graphs for the selection of the proper combination of cutting speed and feed to increase the metal removal rate without sacrificing surface quality. Hasmi et al. [7] also used the RSM model for assessing the influence of the workpiece material on the surface roughness of the machined surfaces. The model was developed for milling operation by conducting experiments on steel specimens. The expression shows, the relationship between the surface roughness and the various parameters; namely, the cutting speed, feed and depth of cut. The above models have not considered the affect of tool geometry on surface roughness.Since the turn of the century quite a large number of attempts have been made to find optimum values of machining parameters. Uses of many methods have been reported in the literature to solve optimization problems for machining parameters. Jain and Jain [8] have usedneural networks for modeling and optimizing the machining conditions. The results have been validated by comparing the optimized machining conditions obtained using genetic algorithms. Suresh et al. [9] have developed a surface roughness prediction model for turning mild steel using a response surface methodology to produce the factor affects of the individual process parameters. They have also optimized the turning process using the surface roughness prediction model as the objective function. Considering the above, an attempt has been made in this work to develop a surface roughness model with tool geometry and cutting conditions on the basis of experimental results and then optimize it for the selection of these parameters within the given constraints in the end milling operation.3 MethodologyIn this work, mathematical models have been developed using experimental results with the help of response surface methodolog y. The purpose of developing mathematical models relating the machining responses and their factors is to facilitate the optimization of the machining process. This mathematical model has been used as an objective function and the optimization was carried out with the help of genetic algorithms.3.1 Mathematical formulationResponse surface methodology(RSM) is a combination of mathematical and statistical techniques useful for modelling and analyzing the problems in which several independent variables influence a dependent variable or response. The mathematical models commonly used are represented by:where Y is the machining response, ϕ is the response function and S, f , α, r are milling variables and ∈is the error which is normally distributed about the observed response Y with zero mean.The relationship between surface roughness and other independent variables can be represented as follows,where C is a constant and a, b, c and d are exponents.To facilitate the determination of constants and exponents, this mathematical model will have to be linearized by performing a logarithmic transformation as follows:The constants and exponents C, a, b, c and d can be determined by the method of least squares. The first order linear model, developed from the above functional relationship using least squares method, can be represented as follows:where Y1 is the estimated response based on the first-order equation, Y is the measured surface roughness on a logarithmic scale, x0 = 1 (dummy variable), x1, x2, x3 and x4 are logarithmic transformations of cutting speed, feed rate, radial rake angle and nose radiusrespectively, ∈is the experimental error and b values are the estimates of corresponding parameters.The general second order polynomial response is as given below:where Y2 is the estimated response based on the second order equation. The parameters, i.e. b0, b1, b2, b3, b4, b12, b23, b14, etc. are to be estimated by the method of least squares. Validity of the selected model used for optimizing the process parameters has been tested with the help of statistical tests, such as F-test, chi square test, etc. [10].3.2 Optimization using genetic algorithmsMost of the researchers have used traditional optimization techniques for solving machining problems. The traditional methods of optimization and search do not fare well over a broad spectrum of problem domains. Traditional techniques are not efficient when the practical search space is too large. These algorithms are not robust. They are inclined to obtain a local optimal solution. Numerous constraints and number of passes make the machining optimization problem more complicated. So, it was decided to employ genetic algorithms as an optimization technique. GA come under the class of non-traditional search and optimization techniques. GA are different from traditional optimization techniques in the following ways:1.GA work with a coding of the parameter set, not the parameter themselves.2.GA search from a population of points and not a single point.3.GA use information of fitness function, not derivatives or other auxiliary knowledge.4.GA use probabilistic transition rules not deterministic rules.5.It is very likely that the expected GA solution will be the global solution.Genetic algorithms (GA) form a class of adaptive heuristics based on principles derived from the dynamics of natural population genetics. The searching process simulates the natural evaluation of biological creatures and turns out to be an intelligent exploitation of a random search. The mechanics of a GA is simple, involving copying of binary strings. Simplicity of operation and computational efficiency are the two main attractions of the genetic algorithmic approach. The computations are carried out in three stages to get a result in one generation or iteration. The three stages are reproduction, crossover and mutation.In order to use GA to solve any problem, the variable is typically encoded into a string (binary coding) or chromosome structure which represents a possible solution to the given problem. GA begin with a population of strings (individuals) created at random. The fitness of each individual string is evaluated with respect to the given objective function. Then this initial population is operated on by three main operators – reproduction cross over and mutation– to create, hopefully, a better population. Highly fit individuals or solutions are given theopportunity to reproduce by exchanging pieces of their genetic information, in the crossover procedure, with other highly fit individuals. This produces new “offspring” solutions, which share some characteristics taken from both the parents. Mutation is often applied after crossover by altering some genes (i.e. bits) in the offspring. The offspring can either replace the whole population (generational approach) or replace less fit individuals (steady state approach). This new population is further evaluated and tested for some termination criteria. The reproduction-cross over mutation- evaluation cycle is repeated until the termination criteria are met.4 Experimental detailsFor developing models on the basis of experimental data, careful planning of experimentation is essential. The factors considered for experimentation and analysis were cutting speed, feed rate, radial rake angle and nose radius.4.1 Experimental designThe design of experimentation has a major affect on the number of experiments needed. Therefore it is essential to have a well designed set of experiments. The range of values of each factor was set at three different levels, namely low, medium and high as shown in Table 1. Based on this, a total number of 81 experiments (full factorial design), each having a combination of different levels of factors, as shown in Table 2, were carried out.The variables were coded by taking into account the capacity and limiting cutting conditions of the milling machine. The coded values of variables, to be used in Eqs. 3 and 4, were obtained from the following transforming equations:where x1 is the coded value of cutting speed (S), x2 is the coded value of the feed rate ( f ), x3 is the coded value of radial rake angle(α) and x4 is the coded value of nose radius (r).4.2 ExperimentationA high precision ‘Rambaudi Rammatic 500’ CNC milling machine, with a vertical milling head, was used for experimentation. The control system is a CNC FIDIA-12 compact. The cutting tools, used for the experimentation, were solid coated carbide end mill cutters of different radial rake angles and nose radii (WIDIA: DIA20 X FL38 X OAL 102 MM). The tools are coated with TiAlN coating. The hardness, density and transverse rupture strength are 1570 HV 30, 14.5 gm/cm3 and 3800 N/mm2 respectively.AISI 1045 steel specimens of 100×75 mm and 20 mm thickness were used in the present study. All the specimens were annealed, by holding them at 850 ◦C for one hour and then cooling them in a furnace. The chemical analysis of specimens is presented in Table 3. Thehardness of the workpiece material is 170 BHN. All the experiments were carried out at a constant axial depth of cut of 20 mm and a radial depth of cut of 1 mm. The surface roughness (response) was measured with Talysurf-6 at a 0.8 mm cut-off value. An average of four measurements was used as a response value.5 Results and discussionThe influences of cutting speed, feed rate, radial rake angle and nose radius have been assessed by conducting experiments. The variation of machining response with respect to the variables was shown graphically in Fig. 1. It is seen from these figures that of the four dependent parameters, radial rake angle has definite influence on the roughness of the surface machined using an end mill cutter. It is felt that the prominent influence of radial rake angle on the surface generation could be due to the fact that any change in the radial rake angle changes the sharpness of the cutting edge on the periphery, i.e changes the contact length between the chip and workpiece surface. Also it is evident from the plots that as the radial rake angle changes from 4◦to 16◦, the surface roughness decreases and then increases. Therefore, it may be concluded here that the radial rake angle in the range of 4◦to 10◦would give a better surface finish. Figure 1 also shows that the surface roughness decreases first and then increases with the increase in the nose radius. This shows that there is a scope for finding the optimum value of the radial rake angle and nose radius for obtaining the best possible quality of the surface. It was also found that the surface roughness decreases with an increase in cutting speed and increases as feed rate increases. It could also be observed that the surface roughness was a minimum at the 250 m/min speed, 200 mm/min feed rate, 10◦radial rake angle and 0.8 mm nose radius. In order to understand the process better, the experimental results can be used to develop mathematical models using RSM. In this work, a commercially available mathematical software package (MATLAB) was used for the computation of the regression of constants and exponents.5.1 The roughness modelUsing experimental results, empirical equations have been obtained to estimate surface roughness with the significant parameters considered for the experimentation i.e. cutting speed, feed rate, radial rake angle and nose radius. The first order model obtained from the above functional relationship using the RSM method is as follows:The transformed equation of surface roughness prediction is as follows:Equation 10 is derived from Eq. 9 by substituting the coded values of x1, x2, x3 and x4 in termsof ln s, ln f , lnαand ln r. The analysis of the variance (ANOV A) and the F-ratio test have been performed to justify the accuracy of the fit for the mathematical model. Since the calculated values of the F-ratio are less than the standard values of the F-ratio for surface roughness as shown in Table 4, the model is adequate at 99% confidence level to represent the relationship between the machining response and the considered machining parameters of the end milling process.The multiple regression coefficient of the first order model was found to be 0.5839. This shows that the first order model can explain the variation in surface roughness to the extent of 58.39%. As the first order model has low predictability, the second order model has been developed to see whether it can represent better or not.The second order surface roughness model thus developed is as given below:where Y2 is the estimated response of the surface roughness on a logarithmic scale, x1, x2, x3 and x4 are the logarithmic transformation of speed, feed, radial rake angle and nose radius. The data of analysis of variance for the second order surface roughness model is shown in Table 5.Since F cal is greater than F0.01, there is a definite relationship between the response variable and independent variable at 99% confidence level. The multiple regression coefficient of the second order model was found to be 0.9596. On the basis of the multiple regression coefficient (R2), it can be concluded that the second order model was adequate to represent this process. Hence the second order model was considered as an objective function for optimization using genetic algorithms. This second order model was also validated using the chi square test. The calculated chi square value of the model was 0.1493 and them tabulated value at χ2 0.005 is 52.34, as shown in Table 6, which indicates that 99.5% of the variability in surface roughness was explained by this model.Using the second order model, the surface roughness of the components produced by end milling can be estimated with reasonable accuracy. This model would be optimized using genetic algorithms (GA).5.2 The optimization of end millingOptimization of machining parameters not only increases the utility for machining economics, but also the product quality toa great extent. In this context an effort has been made to estimate the optimum tool geometry and machining conditions to produce the best possible surface quality within the constraints.The constrained optimization problem is stated as follows: Minimize Ra using the model given here:where xil and xiu are the upper and lower bounds of process variables xi and x1, x2, x3, x4 are logarithmic transformation of cutting speed, feed, radial rake angle and nose radius.The GA code was developed using MATLAB. This approach makes a binary coding system to represent the variables cutting speed (S), feed rate ( f ), radial rake angle (α) and nose radius (r), i.e. each of these variables is represented by a ten bit binary equivalent, limiting the total string length to 40. It is known as a chromosome. The variables are represented as genes (substrings) in the chromosome. The randomly generated 20 such chromosomes (population size is 20), fulfilling the constraints on the variables, are taken in each generation. The first generation is called the initial population. Once the coding of the variables has been done, then the actual decoded values for the variables are estimated using the following formula: where xi is the actual decoded value of the cutting speed, feed rate, radial rake angle and nose radius, x(L) i is the lower limit and x(U) i is the upper limit and li is the substring length, which is equal to ten in this case.Using the present generation of 20 chromosomes, fitness values are calculated by the following transformation:where f(x) is the fitness function and Ra is the objective function.Out of these 20 fitness values, four are chosen using the roulette-wheel selection scheme. The chromosomes corresponding to these four fitness values are taken as parents. Then the crossover and mutation reproduction methods are applied to generate 20 new chromosomes for the next generation. This processof generating the new population from the old population is called one generation. Many such generations are run till the maximum number of generations is met or the average of four selected fitness values in each generation becomes steady. This ensures that the optimization of all the variables (cutting speed, feed rate, radial rake angle and nose radius) is carried out simultaneously. The final statistics are displayed at the end of all iterations. In order to optimize the present problem using GA, the following parameters have been selected to obtain the best possible solution with the least computational effort: Table 7 shows some of the minimum values of the surface roughness predicted by the GA program with respect to input machining ranges, and Table 8 shows the optimum machining conditions for the corresponding minimum values of the surface roughness shown in Table 7. The MRR given in Table 8 was calculated bywhere f is the table feed (mm/min), aa is the axial depth of cut (20 mm) and ar is the radial depth of cut (1 mm).It can be concluded from the optimization results of the GA program that it is possible toselect a combination of cutting speed, feed rate, radial rake angle and nose radius for achieving the best possible surface finish giving a reasonably good material removal rate. This GA program provides optimum machining conditions for the corresponding given minimum values of the surface roughness. The application of the genetic algorithmic approach to obtain optimal machining conditions will be quite useful at the computer aided process planning (CAPP) stage in the production of high quality goods with tight tolerances by a variety of machining operations, and in the adaptive control of automated machine tools. With the known boundaries of surface roughness and machining conditions, machining could be performed with a relatively high rate of success with the selected machining conditions.6 ConclusionsThe investigations of this study indicate that the parameters cutting speed, feed, radial rake angle and nose radius are the primary actors influencing the surface roughness of medium carbon steel uring end milling. The approach presented in this paper provides n impetus to develop analytical models, based on experimental results for obtaining a surface roughness model using the response surface methodology. By incorporating the cutter geometry in the model, the validity of the model has been enhanced. The optimization of this model using genetic algorithms has resulted in a fairly useful method of obtaining machining parameters in order to obtain the best possible surface quality.中文翻译选择最佳工具,几何形状和切削条件利用表面粗糙度预测模型端铣摘要:刀具几何形状对工件表面质量产生的影响是人所共知的,因此,任何成型面端铣设计应包括刀具的几何形状。

机床加工外文文献翻译

机床加工外文文献翻译

机床加工外文文献翻译(含:英文原文及中文译文)文献出处:Shunmugam M. Basic Machining Operations and Cutting Technology[J]. Journal of the Institution of Engineers, 2014, 1(2):22-32. 英文原文Basic Machining Operations and Cutting TechnologyShunmugam MBasic Machining OperationsMachine was developed from the early Egyptian pedal car and John Wilkinson's trampoline. They provide rigid support for workpieces and tools and can precisely control their relative position and relative speed. Basically, metal cutting refers to a sharpened pry tool that removes a very narrow metal from the surface of a tough workpiece. Chips are discarded products. Compared with other workpieces, the chips are shorter, but there is a certain increase in the thickness of the uncut parts. The geometry of the workpiece surface depends on the shape of the tool and the path of the tool during machining operations.Most machining processes produce parts of different geometries. If a rough workpiece rotates on the central axis and the tool cuts into the workpiece surface parallel to the center of rotation, a rotating surface is created. This operation is called turning. If a hollow tube is machined onthe inner surface in the same way, this operation is called boring. When the diameter is evenly changed, a conical outer surface is produced, which is called taper turning. If the tool contact point moves in a way that changes the radius, then a workpiece with a contour like a ball is produced; or if the workpiece is short enough and the support is very rigid, then the forming tool normally feeds one outside the axis of rotation. Surfaces can be produced, and short tapered or cylindrical surfaces can also be formed.Flat surfaces are often required and they can be produced by radial turning of tool contact points with respect to the axis of rotation. It is easier to fix the tool and place the workpiece under the tool for larger workpieces while planing. The tool can feed reciprocally. The forming surface can be produced by a forming tool.Multi-blade cutters can also be used. Using a double-edged groove drilling depth is 5-10 times the hole diameter. Regardless of whether the drill rotates or the workpiece rotates, the relative motion between the cutting edge and the workpiece is an important factor. During milling, a rotating tool with many cutting edges comes into contact with the workpiece and the workpiece slowly moves relative to the tool. Flat or shaped surfaces may occur depending on the tool geometry and feed method. A horizontal or vertical axis rotation can be generated and can be fed in any of three coordinate directions.Basic machineThe machine tool produces parts with special geometry and precise dimensions by removing chips from plastic material. The latter is waste, which is a change from the long continuous strip of plastic material such as steel, which is useless from a processing point of view. It is easy to handle cracked chips produced from cast iron. The machine performs five basic metal removal processes: turning, planing, drilling, and milling. All other metal removal processes are modified from these five basic procedures. For example, boring is internal turning; reaming, tapping and counterboring are further machining of drilled holes; gear machining is based on Milling operation. Polishing and sanding are deformations that grind and remove the abrasive process. Therefore, there are only four basic types of machine tools that use specially controllable cutting tools: 1. Lathes, 2. Drilling machines, 3. Milling machines, 4. Grinding machines. The grinding process forms chips, but the geometry of the abrasive particles is uncontrollable.The amount and speed of material removal through various processing steps is enormous, just as high facets are removed in large turning operations, or in extremely small grinding and ultra-precision machining. A machine tool fulfills three major functions: 1. It supports work pieces or fixtures and tools 2. It provides relative motion to work pieces and tools 3. In each case provides a range of feeds and generallyup to 4-32 species Speed choices.Processing speed and feedSpeed, feed, and depth of cut are three major variables in economic processing. The other quantities are tapping and tool material, coolant and tool geometry. The speed of the metal removal and the power required are dependent on these variables.Depth of cut, feed, and cutting speed are the mechanical parameters that must be established in any metalworking process. They all affect the force, speed and speed of metal removal. The cutting speed can be defined as the radius of the velocity recording surface that spreads radially at any instant during one revolution, or the distance between two adjacent grooves. The depth of cut is the depth of entry and the depth of the trench.Turning in the center of the latheBasic operations completed on a motorized bed have been introduced. Those operations that use a single point tool on the outside surface are called turning. In addition to drilling, reaming, and grinding of internal surfaces, the operation is done by a single point tool. All machining operations, including turning, can be categorized as roughing, finishing or semi-finishing. Finishing removes a large amount of material as quickly and efficiently as possible, while a small part of the material left on the workpiece is used for finishing. Finishing isThe workpiece gets the final size, shape and surface accuracy. Sometimes semi-finishing leaves a predetermined amount of material for finishing, which is prior to finishing.In general, longer workpieces are simultaneously supported by one or two lathe centers. Conical holes, so-called center holes, are drilled at both ends for the center of the lathe - usually along the axis of the cylindrical workpiece. The end of the workpiece near the frame is usually supported by the center of the tailstock. At the end near the main bearing is the center of the main bearing or clamped by the jaw plate. This method can firmly tighten the workpiece and can smoothly transmit the force to the workpiece. The auxiliary support provided by the chuck to the workpiece reduces the chattering tendency during cutting. If the chuck can be carefully and accurately used to support the workpiece, then Accurate results can be obtained.Supporting the workpiece between two centers can give very accurate results. One end of the workpiece has been machined, then the workpiece can be turned. The other end is machined on a lathe, and the center hole serves as a precise positioning surface and a supporting surface for carrying the weight of the workpiece and resisting the cutting force. When the workpiece is removed from the lathe for any reason, the center hole will accurately return the workpiece to this lathe or another lathe or a cylindrical grinder. Workpieces are not allowed to be clampedon the main bearing by the chuck and lathe center. However, the first thing that comes to mind is a method of quickly adjusting the workpiece on the chuck, but this is not allowed because it is impossible to hold the center of the lathe while holding it by the chuck. The adjustment provided by the center of the lathe will not continue and the claw plate pressure will damage the center hole and lathe center, and even the lathe spindle. The floating claw plate provides an exception to the above statement. It is used almost exclusively for high production work. These chucks are real job drivers and are not used for the same purpose as ordinary three-jaw, four-jaw chucks.While large-diameter workpieces are fashioned in two centers, they are preferably held by the panel at the tail of the main bearing for smooth energy conversion; many lathe chucks do not provide sufficient energy conversion, although they can be used as special energy conversions.Mechanical processing introductionAs a method of producing a shape, machining is the most commonly used and the most important method in all manufacturing processes. The machining process is a process of producing a shape in which the drive device removes some of the material on the workpiece as chips. Although in some cases, the workpiece is supported using mobile equipment without support, most machining operations are performed by equipment that supports both the workpiece and the tool.Small batch, low cost. Machining has two applications in the manufacturing industry. Casting, forging, and pressure work produce each special shape, even one part, almost always with a higher mold cost. The shape of the weld depends largely on the raw material. By using equipment that has a high overall cost but does not have a special mold, machining is possible; starting from almost any kind of raw material, the shape is designed from any material as long as the external dimensions are large enough. Processing is therefore the preferred method. When producing one or several parts or even in mass production, the design of the parts logically leads to the casting, forging or stamping of the product. High precision, surface accuracy. The second application of mechanical machining is based on the possible high precision and surface accuracy. If mass production occurs in other processes, many low-volume components will produce low but acceptable tolerances. On the other hand, many parts produce general shapes from some large deformation processes and are only machined on selected surfaces with very high accuracy. For example, the inside process is seldom produced by any other machining method and the hole on the part may be processed immediately after the pressure operation.The main cutting parametersThere are four factors that fully describe the relationship between the basic tooling work during cutting: tool geometry, cutting speed and depthof cut. The tool must be made of a suitable material; it must have a certain strength, roughness, hardness and fatigue resistance. The tool geometry is described by face and angle and is correct for each cutting operation. Cutting speed refers to the speed at which the cutting edge passes through the work surface, which has been expressed in feet per minute. For machining efficiency, the cutting speed must be of an appropriate scale relative to the particular working combination. In general, the harder the work, the lower the speed. Feed is the rate at which the tool enters the workpiece. When the workpiece or tool rotates, the feed rate is in inches per revolution. When the tool or workpiece moves back and forth, the unit of feed is inches. In general, the feed rate is inversely proportional to the cutting speed in other similar situations. The cutting speed is expressed in inches and is represented by the distance the tool enters the workpiece. It refers to the width of the chips when turning or the thickness of the chips when cutting in a straight line. The depth of cut during roughing is greater than the depth of cut during finishing.Effect of Cutting Parameter Change on Cutting TemperatureIn metal cutting operations, heat is generated in the primary and secondary deformation zones and these results in complex temperatures throughout the tool, workpiece, and chips. A typical isothermal as shown in the figure, it can be seen that as predicted, when the workpiece materialundergoes major deformation and is reduced, there is a very large temperature gradient throughout the entire width of the chip. When the chips in the second deformed zone still have a short distance, the maximum temperature is reached.Because almost all of the work is done with metal cutting converted to heat, it can be predicted that the increased energy consumption per unit volume of metal removed will increase the cutting temperature. Therefore, when all the other parameters are unchanged, the rake angle becomes larger and the energy and cutting temperature per unit volume of metal removed will be reduced. When considering the increase in the thickness and speed of the non-formed chips, the situation is even more complicated. Increasing the thickness of the cut will often greatly affect the amount of heat transferred to the workpiece, the number of tools, and will keep the chips at a fixed amount, and at the same time the change in cutting temperature will be small. However, increasing the cutting speed will reduce the amount of heat transferred to the workpiece. This will increase the temperature rise of the main deformation of the chips. In addition, the second deformation zone is relatively small, and in this deformation zone it will increase the temperature. The other changes in cutting parameters hardly affect the removal of energy consumption per unit volume and the cutting temperature. It has thus been shown that even small changes in cutting temperature have a significant effect on toolwear rate, and it is appropriate to estimate the cutting temperature from the cutting data. The most direct and accurate method of testing high-speed steel tools, Trent gave detailed information on the temperature distribution of high-speed steel tools. This technique is based on the data detection of high-speed steel tools and is related to the microscopic changes in thermal history.Trent has described the measurement of cutting temperature and the temperature distribution of high-speed steel tools when machining a wide range of workpieces. Using scanning electron microscopy to study fine-scale microstructure changes, this technique has been further developed. This technique is also used to study the temperature distribution of high-speed steel single-point turning tools and twist drills.Tool wearBrittle fractures have been treated and there are basically three types of tool wear. Back flank wear, boundary wear and flank wear. Face wear occurs at the major and minor cutting edges. The main cutting edge is responsible for the removal of large amounts of metal, which increases the cutting force and temperature, and if left unchecked the vibration of the tool and the workpiece can be caused, and this can no longer be cut efficiently. The secondary cutting edge determines the workpiece size and surface finish. Wear of the flank causes poor surface accuracy in a large number of products. According to the actual cutting conditions, the mainreason for the unacceptable use of the tool is that the wear of the main flank before the secondary flank is very large, which results in the generation of an unacceptable portion. Due to the stress distribution of the tool, the frictional force in the sliding area is maximized between the chip and the surface at the beginning of sliding, and the final frictional force is zero. Therefore, abrasive wear occurs in this area. More wear occurs between the chip and the disengagement area adjacent to the area, which is more than adjacent to this point.This results in a localized pitting of the tool face at a certain distance from the face, which is usually partly arc-shaped. In many respects and based on actual cutting conditions, the boundary wear is a less severe wear than the flank, so that the wear of the face is a relatively common blunt standard. Then, as various authors have shown, with the increase of cutting speed, the increase of surface temperature is more than the increase of the blade surface, and because the temperature change seriously affects any type of wear rate, boundary wear usually occurs at higher cutting speeds. Situation.Where the tool is in contact with the uncut surface, the wear of the trailing portion of the main flank is more pronounced than that along the remaining wear surface. This is because the local influences such as the uncut surface are caused by the work hardening caused by the previous cutting, oxidation scale, and local high temperature. This localized wearis generally related to the wear of the boundary and is sometimes severe. Although the occurrence of a notch does not seriously affect the cutting performance of the tool, the notch is often deeper, and it is likely that the cutting tool will break if it continues.If any form of gradual wear continues to make its dramatic existence, the tool will face catastrophic failures, such as the cutting tool can not be cut, in good condition, the workpiece is scrapped, at worst, the mechanical tool may cause damage. For cemented carbide tools and various types of wear and tear, the maximum service life limit is reached before a catastrophic failure occurs. However, wear on high-speed steel cutting tools is uneven. It has been found that when wear continues and even catastrophic failure occurs, the most meaningful and reproducible results are obtained, but in practice, the cutting time is much less. At the time of failure. Several phenomena occur when a catastrophic failure occurs. The most common is a sudden increase in cutting force, a bright ring in the workpiece, and a significant increase in noise.Surface finishing mechanismThere are five basic mechanisms that affect the processed product: (1) The basic geometry of the cutting process, the single-point turning tool will advance axially a constant distance, the resulting surface will be on it, and the tool will feed in the vertical direction. A series of sharp points form the basic shape of the cutting tool. (2) The efficiency ofcutting. It has already been mentioned that an unstable tumor will produce a face that contains hardened tumor segments. This fragment reduces the surface finish. It can also be proved that under heavy cutting conditions, large feed rates, small rake angles and low cutting speeds can be used. In addition to these, the production conditions can also lead to unstable BDE products. The cutting process becomes unstable rather than continuous cutting in the shear zone. , Shattered, uneven discontinuous chips appear, and the surface is not smooth enough. This is especially true when working with ductile materials. (3) The stability of the machine tool. According to certain combinations of cutting conditions, workpiece dimensions, clamping methods and stiffness relative to the machine structure, instability is a tool-induced chatter. Under certain conditions, this kind of vibration will reach and maintain a certain amplitude, and vibrations based on other conditions will also be generated, unless the cutting prevents considerable damage or both the cutting tool and the workpiece may vibrate. This phenomenon is called chattering.Axial turning features a long spiral band on the workpiece and short pitch fluctuations on the temporary machined surface. (4) Remove the effectiveness of cuttings. In intermittent chip production processes, such as milling and turning of brittle materials, it is expected that whether due to gravity or cutting fluid, chips will leave the cutting zone and in any case will not affect the cutting surface. Consecutive chips are obvious,and if no measures are taken to control the chips, they may affect the cutting surface and leave marks. Inevitably, this marks only expectations.(5) The effective relief angle of the cutting tool. For small cutting edges and relief angles with a certain geometry, it is possible to cut at the main cutting edge and polish at the secondary cutting edge. This will result in good surface accuracy, but of course this combination of strictly metal forming cannot be recommended as an actual cutting method. However, due to occasional occurrence of these conditions, tool wear can cause changes in the surface properties.Limits and tolerancesMechanical parts are manufactured so they are interchangeable. In other words, each mechanical part or device is made to a size and shape suitable for other types of machines. In order to make the parts interchangeable, each part is dimensioned to fit the corresponding part in the right way. This is not only impossible, but it is impractical to make many parts into one size. This is because the machine is not perfect and the tool wears. A slight deviation from the correct size is usually allowed. The size of this deviation depends on the type of part being manufactured. For example, a part may be 6 inches and the upper and lower deviation is 0003 inches (one thousandth of a thousandth). So this deviation can be between 5,997 inches and 6003 inches and still maintain the correct size. This is bias. The difference between the upper and lower deviations is theThe tolerance is the maximum amount of change in part size, and the basic size is the size limit derived from the allowable variation and tolerance range. Sometimes the deviation allows only one direction to change. It allows the tolerance to change in the hole or axis without seriously affecting the fit. When the tolerance changes in both directions, it is called full deviation (positive and negative). The full deviation is separate and there will be on each side of the basic size. The limit size is only the largest size and the smallest size. Therefore, the to lerance is the difference between these two dimensions.Surface accuracy and size controlProducts have been completed in their proper shape and size, and often require some type of surface accuracy to enable them to perform their own functions. In some cases, in order to resist scratching and scratching, it is necessary to improve the physical properties of the surface material. In many manufacturing processes, dirt, chips, grease or other harmful substances are left on the surface of the product. Mixtures of different materials, the same materials processed in different ways, may require some special surface treatment to provide a uniform appearance.基本加工工序和切削技术Shunmugam M基本加工的操作机床是从早期的埃及人的脚踏动力车和约翰·威尔金森的镗床发展而来的。

分析数控机床改造外文文献翻译、中英文翻译、外文翻译

分析数控机床改造外文文献翻译、中英文翻译、外文翻译

Analysis of transformation of numerical controlmachine toolIn order to survival and development of enterprises, improve the rate of CNC machine tools is necessary. Transformation of the equipment needed for NC machine tools in general, including traditional and recently introduced from abroad, due to a problem can not be put into the machine tool equipment and production lines. First, transform the contents of the NCCNC machine tools and production line transformation of the main contents are: (1) restoration of the original function, machine tools, production lines there is some fault diagnosis and recovery; (2)NC-based, in the general machine tools addend remarkable device or add numerical control system; ( 3) The renovation, to improve accuracy, efficiency and degree of automation, mechanical, electrical parts of the renovation, the mechanical part of there-assembly process, to restore the original precision; can not meet the production requirements of its CNC system be updated with the latest CNC; (4) technology updates or technical innovation, in order to improve performance or grade, or for the use of new technology, new technology, based on the original large-scale technology updates or technical innovation.Second, the development trend of CNC systeml. To open, the sixth generation of PC-based directionThe openness of the PC-based, low-cost, high reliability, rich in natural resources such as hardware and software features, and more CNC system manufacturer will be to go down this path. At least with PC, as its front-end machines, to deal with man-machine interface, programming, networking and communications issues, the original system to take over some tasks PC CNC machines has the friendly interface, will reach all of the CNC system. The remote communication, remote diagnostics and maintenance of applications will be more common.2. To the development of high-speed and high precision.3. To the intelligent direction(1) The application of adaptive control technology. Numerical control system can detect the process of important information and automatically adjust system parameters, improving the system operation status.2) the introduction of expert systems to guide processing. Will be skilled workers and expertise, processing and general laws and special laws into the system to process parameter database support, establish an artificial intelligence expert system.(3) the introduction of fault diagnosis expert system(4) intelligent digital servo drives. Can automatically identify the load and automatically adjust the parameters of the drive system to get the best state of operation.Third, the choice of numerical control system1. Open-loop systemThe system's servo-driven device is a stepper motor, power stepper motors, electro-hydraulic pulse motors. This system does not require position and velocity feedback, displacement accuracy depends mainly on the angular displacement precision stepper motor and gear drive components such as precision screw, so displacement of low accuracy. But the system is simple, debugging easy maintenance, reliable, low cost, easily converted successfully.2. Closed-loop systemThe system consists of grating, sensor position detection device synchronization, etc. The actual measured position signal fed back to the computer, compared with a given value, the difference between the two amplification and transformation, driving the implementing agencies in order to eliminate bias. The system complexity, high cost and strict temperature requirements on the environment. But thesystem of high precision, speed and big power. According to technological requirements and decide whether to adopt.3. Semi-closed-loop systemSemi-closed-loop system detects components installed in the middle of transmission parts, the indirect measurement of the location of the implementation of parts. It can only compensate for part of the components within the system loop error, and therefore its more accurate than the accuracy of closed-loop system is low, but its structure and debugging as compared with the closed-loop system is simple.Current production numerical control system are more companies and manufacturers, foreign companies such as Siemens of Germany, Japan, Fanuc, Inc.; domestic Everest companies such as China, the Beijing Aerospace CNC System Corporation, Huazhong CNC CNC high-grade corporate and Shenyang National Engineering Research Center. Select CNC systems are mainly based on numerical control after transformation to be achieved in a variety of precision machine tools, drive motor power and the user's requirements to determine. Fourth, the main steps CNC transformation1. Determination of rehabilitation programs(1) Mechanical and Electrical Repair transformation combined.Generally speaking, in need of transformation of electrical machines, are in need of mechanical repair. To determine repair requirements, scope and content; have to ascertain the electrical modification of the mechanical structure in need of transformation requirements and content; but also determine the transformation of electrical and mechanical repair, reconstruction staggered between the time requirements. Mechanical properties of intact are electrical transformation success.(2) the easier issues first, after the first partial overall. Determine the transformation step, the whole electrical part of the transformation should be divided into several sub-systems, the basic shape of various systems to be connected after the completion of the whole system work. In each subsystem, we should do first the less technical, workload the larger work, and then do a technical high, requiring fine work, can focus people's attention to key areas.(3) selection system under conditions of use. For the transformation of the object to determine its environment and conditions, which the selection of electrical system protection, anti-jamming, self-cooling and air filtering performance can provide the correct basis. Electrical system options must also be considered mature products, their performance should be reasonable and practical, there are spare parts to provide maintenance support, features a number of years to meetthe current and future development requirements.(4) The implementation and responsibilities of personnel involved in reconstruction.(5) The transformation of the determination of the scope and cycle.2. Transformation of the technical preparation(1) mechanical parts ready. In line with the transformation of mechanical electrical repairs should be completed in advance. The same time, be demolished and replaced and processing should be part of such advance planning is necessary to properly interface with the entire transformation.(2) The electrical information on the new system to digest.(3) The conversion of the old system interface design. According to the scope of each of the different equipment modification required to pre-designed interface, part of the conversion, if the entire transformation should be designed to convert mechanical and electrical interfaces, operation panel control and configuration, the Internet part of the contact, parameter measurement, the maintenance and so on. Require the operation and maintenance easy and reasonable, alignments, fluent, primary and secondary connection point less electrical interference with the strength of the smallest, with an appropriate margin and so on. Local transformation, but also need to consider the performance of the system match theold and new, the voltage polarity and size of change, the installation location, digital-analog conversion, etc., if necessary, need to create their own interfaces.(4) operation and programming staff technical training. ①training should cover the new control panel configuration, function and meaning of the instructions; ②the scope of the new system features, use, and the difference between the old system; ③maintenance requirements; ④programming standards and automated programming and more. Focused understood, grasp operating instructions and programming instructions.(5) Debugging steps and acceptance criteria for the determination. Debugging should be done by the project leader carried out with the others. Debugging step can be from simple to complex, from small to large, from outside to inside, you can also after the first local situation, the whole system after the first subsystem. The development of acceptance criteria must be realistic, too high or too low a standard will have a negative impact on the transformation.3. The implementation of reform(1) The overall maintenance of the machine. The long-term use of the original machine, you need to conduct a comprehensive maintenance. Secondly, the response to machine tools to make achange before the geometric accuracy, dimensional accuracy of measurement, and for the record. In this way pairs of reference to guide the transformation of the role, but also in the transformation of the end for comparison analysis.(2) to retain the electrical adjustment of some of the best. If the electrical system as part of the transformation, in turn, should retain the parts of the maintenance and optimization adjustments, such as high power part of the spare parts replacement, electrical maintenance, drying transformer insulation, pollution, cleaning, ventilation and cooling equipment cleaning, servo Drive optimization adjustments, update aging wires and cables, connectors and other fastening. Only the electrical part of the reservation and do excellent optimization adjustment, in order to ensure that transformed the machine tool have lower failure rates.(3) The original systems were dismantled. The removal of the original system must be controlled carefully to the original drawings in time to make mark in the drawings to prevent the omission or been demolished. In the process of demolition will find some of the new system design in the gaps, it is timely to add and correction. Removed the system should be properly safeguarded in case of unsuccessful reconstruction resume use. There is a definite value, and can be used for spare parts.(4) reasonable arrangements for the location and wiring the new system. Connection must be a clear division of labor, there is one person review the inspection to ensure that the connection process specifications, diameter suitable, correct, reliable and beautiful. (5) debugging. Debug must be pre-established procedures and requirements. Debugging the first to test the safety protection system sensitivity, personal and equipment to prevent accidents. Debugging the site must be clean; the moving coordinate extension units at the center of the whole trip; be able to load test, the first no-load after load; can simulate the experiment, the first real action after simulated; be manual, first manually and automatically.4. Acceptance and post-work(1) The mechanical properties of machine tool acceptance. Machine tool should meet the requirements of the mechanical properties, geometric accuracy should be within the limits prescribed.(2) The electrical control functions and control accuracy and acceptance. The various functions of electrical control actions must meet the normal, sensitive and reliable. Control precision application system itself functions (such as step size, etc.) and standard measuring apparatus (such as laser interferometer, coordinate measuring machine, etc.) control checks, to reach within a range. Should also be modified before the machine with the functions andaccuracy to make comparison, access to quantifiable indicators of difference.(3) The test piece cutting and acceptance. Can refer to the relevant domestic and international standards for CNC cutting specimens, in a qualified operator, the programmer with the trial under the cut. Specimen cutting machine tools can be acceptance of stiffness, cutting force, noise, motion trajectory, related actions, are generally not suitable for specimen use of a product part.(4), drawings, information and acceptance. Machine transformation finished, should be promptly drawings, data, transform the file summary, collate, transfer into the file. This is the future and stable operation of the equipment is very important.(5) Summary and improve.5, numerical examples of reconstruction1. Milling machine with the Siemens 810M transformation X53In 1998, the company invested 200,000 yuan, with Germany's Siemens 810M CNC system, 611A AC servo drive system on the company's X53 model of a milling machine to X, Y, Z three-axis numerical control transformation. Retained the original spindle system and cooling system. -Axis transformation of a ball screw used in the machinery and gear transmission mechanism. Thetransformation of work includes mechanical design, electrical design, PLC program preparation and debugging, machine tool repair, machine installation and debugging. After transformation, milling, processing and effective travel X, Y, Z axis respectively, 880mm, 270mm, 280mm; maximum speed of X, Y, Z axis respectively, 5 000mm/min, 1 500mm/min, 800mm/min; point moving speed of X, Y, Z axis respectively 3 000mm/min, 1 000mm/min, 500 mm / min; machining accuracy of ± 0.001 mm. Machine tools, coordinate linkage to be completed by a variety of complex curve or surface processing.2. GSK980T and stepper drive system with the transformation ofC6140 latheIn 1999, the company invested 8 million yuan, with Guangzhou CNC Equipment Factory production GSK980T numerical control system, DY3 hybrid stepper drive unit on the company's a longerC6140 lathe X, Z 2-axis transform. Retained the original spindle system and cooling system. Transformation of two-axis ball screw in the machinery used, and synchronous transmission. The transformation of work includes mechanical design, electrical design, machine overhaul and machine installation and debugging. Lathe After the transformation, processing and effective stroke X, Z axis respectively, 390mm, 1400mm; maximum speed X, Z axisrespectively, 1 200mm/min, 3 000mm/min; jog speed 400mm/min; point moving fast X, Z-axis respectively, 1 200mm/min, 3000mm/min; machine smallest mobile unit 0.001mm.6, numerical transformation of the issues and recommendations1. Transformation problems in NCCNC machine tools through several transformation and found work, there are also many problems, mainly reflected in: (a) The departments, developers uncertain functions, organizational chaos, a serious impact on progress in the transformation; (2) to develop the work process and plans are mostly developed rule of thumb, less reasonable; (3) the training of relevant personnel is not in place, resulting in machine tool technology officers will not be modified after programming, the operator of the machine operator unskilled and so on.2. Transformation of the proposed NC(1) is responsible for transformation of the staff responsibilities of clear penalties and rewards, fully mobilize the enthusiasm of the staff; train a batch of high-quality applications and maintenance personnel, training for selected officers to go out and learn the advanced technologies;(2) To focus on users, maintenance of CNC system of technicaltraining, the establishment of numerical control technology at home and abroad resource library. The establishment of technical data files, do the work of spare parts.分析数控机床改造为了我国民营企业的生存与发展,提高数控机床的速度是必要的。

机械类数控车床外文翻译外文文献英文文献数控

机械类数控车床外文翻译外文文献英文文献数控

数控加工中心技术开展趋势与对策原文来源:Zhao Chang-ming Liu Wang-ju(C Machining Processand equipment,2002,China)一、摘要Equip the engineering level, level of determining the whole national economy of the modernized degree and modernized degree of industry, numerical control technology is it develop new developing new high-tech industry and most advanced industry to equip (such as information technology and his industry, biotechnology and his industry, aviation, spaceflight, etc. national defense industry) last technology and getting more basic most equipment.Numerical control technology is the technology controlled to mechanical movement and working course with digital information, integrated products of electromechanics that the numerical control equipment is the new technology represented by numerical control technology forms to the manufacture industry of the tradition and infiltration of the new developing manufacturing industry,Keywords:Numerical ControlTechnology, E quipment,industry二、译文数控技术和装备开展趋势与对策装备工业的技术水平和现代化程度决定着整个国民经济的水平和现代化程度,数控技术与装备是开展新兴高新技术产业和尖端工业〔如信息技术与其产业、生物技术与其产业、航空、航天等国防工业产业〕的使能技术和最根本的装备。

(数控加工)机械类数控外文翻译外文文献英文文献数控

(数控加工)机械类数控外文翻译外文文献英文文献数控

(数控加工)机械类数控外文翻译外文文献英文文献数控NumericalControlOneofthemostfundamentalconceptsintheareaofadvancedmanufacturingte chnologiesisnumericalcontrol(NC).PriortotheadventofNC,allmachinetools weremanualoperatedandcontrolled.Amongthemanylimitationsassociatedwith manualcontrolmachinetools,perhapsnoneismoreprominentthanthelimitation ofoperatorskills.Withmanualcontrol,thequalityoftheproductisdirectlyre latedtoandlimitedtotheskillsoftheoperator.Numericalcontrolrepresentst hefirstmajorstepawayfromhumancontrolofmachinetools.Numericalcontrolmeansthecontrolofmachinetoolsandothermanufacturin gsystemsthoughtheuseofprerecorded,writtensymbolicinstructions.Rathert hanoperatingamachinetool,anNCtechnicianwritesaprogramthatissuesoperat ionalinstructionstothemachinetool,Foramachinetooltobenumericallycontr olled,itmustbeinterfacedwithadeviceforacceptinganddecodingthep2ogramm edinstructions,knownasareader.Numericalcontrolwasdevelopedtoovercomethelimitationofhumanoperato r,andithasdoneso.Numericalcontrolmachinesaremoreaccuratethanmanuallyo peratedmachines,theycanproducepartsmoreuniformly,theyarefaster,andthe long-runtoolingcostsarelower.ThedevelopmentofNCledtothedevelopmentofs everalotherinnovationsinmanufacturingtechnology:1.Electricaldischargemachining.sercutting.3.Electronbeamwelding.Numericalcontrolhasalsomademachinetoolsmoreversatilethantheirmanuallyoperatedpredecessors.AnNCmachinetoolcanautomaticallyproduceawidev arietyofpar4s,eachinvolvinganassortmentofundertaketheproductionofprod uctsthatwouldnothavebeenfeasiblefromaneconomicperspectiveusingmanuall ycontrolledmachinetoolsandprocesses.Likesomanyadvancedtechnologies,NCwasborninthelaboratoriesoftheMas sachusettsInstituteofTechnology.TheconceptofNCwasdevelopedintheearly1 950swithfundingprovidedbytheU.SAirForce.Initsearlieststages,NCmachine swereabletomakestraightcutsefficientlyandeffectively.However,curvedpathswereaproblembecausethemachinetoolhadtobeprogra mmedtoundertakeaseriesofhorizontalandverticalstepstoproduceacurve.The shorteristhestraightlinesmakingupthestep,thesmootheris4hecurve.Eachli nesegmentinthestepshadtobecalculated.Thisproblemledtothedevelopmentin1959oftheAutomaticallyProgrammedT ools(APT)languageforNCthatusesstatementssimilartoEnglishlanguagetodef inethepartgeometry,describethecuttingtoolconfiguration,andspecifythen ecessarymotions.ThedevelopmentoftheAPTlanguagewasamajorstepforwardint hefurtherdevelopmentofNCtechnology.TheoriginalNCsystemwerevastlydiffe rentfromthoseusedpunchedpaper,whichwaslatertoreplacedbymagneticplasti ctape.Atapereaderwasusedtointerprettheinstructionswrittenonthetapefor themachine.Together,all/fthisrepresentedgiantstepforwardinthecontrolo fmachinetools.However,therewereanumberofproblemswithNCatthispointinit sdevelopment.Amajorproblemwasthefragilityofthepunchedpapertapemedium.Itwascomm onforthepapercontainingtheprogrammedinstructionstobreakortearduringam achiningprocess,Thisproblemwasexacerbatedbythefactthateachsuccessivet imeapartwasproducedonamachinetool,thepapertapecarryingtheprogrammedin structionshadtorerunthoughtthereader.Ifitwasnecessarytoproduce100copi esofagivenpart,itwasalsonecessarytorunthepapertapethoughtthereader100 separatetimes.Fragilepapertapessimplycouldnotwithstandtherigorsofshop floorenvironmentandthiskindofrepeateduse.Thisledtothedevelopmentofaspecialmagnetictape.Whereasthepapertape carriedtheprogrammedinstructionsasaseriesofholespunchedinthetape,theT hismostimportantofthesewasthatitwasdifficultorimpossibletochangethein structionsenteredonthetape.Tomakeeventhemostminoradjustmentsinaprogra mofinstructions,itwasnecessarytointerruptmachiningoperationsandmakean ewtape.Itwasalsostillnecessarytorunthetapethoughtthereaderasmanytimes astherewerepartstobeproduced.Fortunately,computertechnologybecomearea lityandsoonsolvedtheproblemsofNC,associatedwithpunchedpaperandplastic tape.Thedevelopmentofaconceptknownasnumericalcontrol(DNC)solvethepaper andplastictapeproblemsassociatedwithnumericalcontrolbysimplyeliminati ngtapeasthemediumforcarryingtheprogrammedinstructions.Indirectnumeric alcontrol,machinetoolsaretied,viaadatatransmissionlink,toahostcompute randfedtothemachinetoolasneededviathedatatransmissionlinkage.Directnumericalcontrolrepresentedamajorstepforwardoverpunchedtapeandplasticta pe.However,itissubjecttothesamelimitationasalltechnologiesthatdependo nahostcomputer.Whenthehostcomputergoesdown,themachinetoolsalsoexperie ncedowntime.Thisproblemledtothedevelopmentofcomputernumericalcontrol.Thedevelopmentofthemicroprocessorallowedforthedevelopmentofprogra mmablelogiccontrollers(PLC)andmicrocomputers.Thesetwotechnologiesallo wedforthedevelopmentofcomputernumericalcontrol(CNC).WithCNC,eachmachi netoolhasaPLCoramicrocomputerthatservesthesamepurpose.Thisallowsprogr Csolvedtheproblems associateddowntimeofthehostcomputer,butitintroducedanotherproblemknow nasdatamanagement.Thesameprogrammightbeloadedontendifferentmicrocompu terswithnocommunicationamongthem.Thisproblemisintheprocessofbeingsolv edbylocalareanetworksthatconnectDigitalSignalProcessorsTherearenumeroussituationswhereanalogsignalstobeprocessedinmanywa ys,likefilteringandspectralanalysis,Designinganaloghardwaretoperformt hesefunctionsispossiblebuthasbecomelessandpractical,duetoincreasedper formancerequirements,flexibilityneeds,andtheneedtocutdownondevelopmen t/testingtime.Itisinotherwordsdifficultpmdesignanaloghardwareanalysis ofsignals.Theactofsamplingansignalintothehatarespecialisedforembeddedsignal processingoperations,andsuchaprocessoriscalledaDSP,whichstandsforDigi talSignalProcessor.TodaytherearehundredsofDSPfamiliesfromasmanymanufacturers,eachonedesignedforaparticularprice/performance/usagegroup.Man yofthelargestmanufacturers,likeTexasInstrumentsandMotorola,offerboths pecialisedDSP’sforcertainfieldslikemotor-controlormodems,andgeneralh igh-performanceDSP’sthatcanperformbroadrangesofprocessingtasks.Devel opmentkitsan`softwarearealsoavailable,andtherearecompaniesmakingsoftw aredevelopmenttoolsforDSP’sthatallowstheprogrammertoimplementcomplex processingalgorithmsusingsimple“drag‘n’drop”methodologies.DSP’smoreorlessfallintotwocategoriesdependingontheunderlyingarch itecture-fixed-pointandfloating-point.Thefixed-pointdevicesgenerallyo perateon16-bitwords,whilethefloating-pointdevicesoperateon32-40bitsfl oating-pointwords.Needlesstosay,thefixed-pointdevicesaregenerallychea per.Anotherimportantarchitecturaldifferenceisthatfixed-pointprocessor stendtohaveanaccumulatorarchitecture,withonlyone“generalpurpose”reg ister,makingthemquitetrickytoprogramandmoreimportantly,makingC-compil ersinherentlyinefficient.Floating-pointDSP’sbehavemorelikecommongene ral-purposeCPU’s,withregister-files.TherearethousandsofdifferentDSP’sonthemarket,anditisdifficulttas kfindingthemostsuitableDSPforaproject.Thebestwayisprobablytosetupacon straintandwishlist,andtrytocomparetheprocessorsfromthebiggestmanufact urersagainstit.The“bigfour”manufacturersofDSPs:TexasInstruments,Motorola,AT&Ta ndAnalogDevices.Digital-to-analogconversionInthecaseofMPEG-Audiodecoding,digitalcompresseddataisfedintotheDS Pwhichperformsthedecoding,thenthedecodedsampleshavetobeconvertedbacki ntotheanalogdomain,andtheresultingsignalfedanamplifierorsimilaraudioe quipment.Thisdigitaltoanalogconversion(DCA)isperformedbyacircuitwitht hesamename&DifferentDCA’sprovidedifferentperformanceandquality,asmea suredbyTHD(Totalharmonicdistortion),numberofbits,linearity,speed,filt ercharacteristicsandotherthings.TheTMS320familyDQPofTexasInstrumentsTheTLS320familyconsistsoffixed-point,floating-point,multiprocesso rdigitalsignalprocessors(D[Ps),andfoxed-pointDSPcontrollers.TMS320DSP haveanarchitecturedesignedspecificallyforreal-timesignalprocessing.Th e’F/C240isanumberofthe’C2000DSPplatform,andisoptimizedforcontrolapp lications.The’C24xseriesofDSPcontrollerscombinesthisreal-timeprocess ingcapabilitywithcontrollerperipheralstocreateanidealsolutionforcontr olsystemapplications.ThefollowingcharacteristicsmaketheTMS320familyth erightchoiceforawiderangeofprocessingapplications:---Veryflexibleinstructionset---Inherentoperationalflexibility---High-speedperformance---Innovativeparallelarchitecture---CosteffectivenessDeviceswithinagenerationoftheTMS320familyhavethesameCPUstructure butdifferenton-chipmemoryandperipheralconfigurations.Spin-offdevicesu senewcombinationsofOn-chipmemoryandperipheralstosatisfyawiderangeofne edsintheworldwideelectronicsmarket.Byintegratingmemoryandperipheralso ntoasinglechip,TMS320devicesreducesystemcostsandsavecircuitboardspace .The16-bit,fixed-pointDSPcoreofthe‘C24xdevicesprovidesanalogdesi gnersadigitalsolutionthatdoesnotsacrificetheprecisionandperformanceof theirsystemperformancecanbeenhancedthroughtheuseofadvancedcontrolalgo rithmsfortechniquessuchasadaptivecontrol,Kalmanfiltering,andstatecont rol.The‘C24xDSPcontrollerofferreliabilityandprogrammability.Analogco ntrolsystems,ontheotherhand,arehardwiredsolutionsandcanexperienceperf ormancedegradationduetoaging,componenttolerance,anddrift.Thehigh-speedcentralprocessingunit(CPU)allowsthedigitaldesignert oprocessalgorithmsinrealtimeratherthanapproximateresultswithlook-upta bles.TheinstructionsetoftheseDSPcontrollers,whichincorporatesbothsign alprocessinginstructionsandgeneral-purposecontrolfunctions,coupledwit htheextensivedevelopmenttimeandprovidesthesameeaseofuseastraditional8 -and16-bitmicrocontrollers.Theinstructionsetalsoallowsyoutoretainyour softwareinvestmentwhenmovingfromothergeneral-purpose‘C2xxgeneration, sourcecodecompatiblewiththe’C2xgeneration,andupwardlysourcecodecompa tiblewiththe‘C5xgenerationofDSPsfromTexasInstruments.The‘C24xarchitectureisalsowell-suitedforprocessingcontrolsignal s.Itusesa16-bitwordlengthalongwith32-bitregistersforstoringintermedia teresults,andhastwohardwareshiftersavailabletoscalenumbersindependent lyoftheCPU.Thiscombinationminimizesquantizationandtruncationerrors,an dincreasesp2ocessingpowerforadditionalfunctions.Suchfunctionsmightinc ludeanotchfilterthatcouldcancelmechanicalresonancesinasystemoranestim ationtechniquethatcouldeliminatestatesensorsinasystem.The‘C24xDSPcontrollerstakeadvantageofansetofperipheralfunctions thatallowTexasInstrumentstoquicklyconfigurevariousseriesmembersfordif ferentprice/performancepointsorforapplicationoptimization.Thislibraryofbothdigitalandmixed-signalperipheralsincludes:---Timers---Serialcommunicationsports(SCI,SPI)---Analog-to-digitalconverters(ADC)---Eventmanager---Systemprotection,suchaslow-voltageandwatchdogtimerTheDSPcontrollerperipherallibraryiscontinuallygrowingandchanging tosuittheoftomorrow’sembeddedcontrolmarketplace.TheTMS320F/C240isthefirststandarddeviceintroducedinthe‘24xserie sofDSPcontrollers.Itsetsthestandardforasingle-chipdigitalmotorcontrol ler.The‘240canexecute20MIPS.Almostallinstructionsareexecutedinasimpl ecycleof50ns.Thishighperformanceallowsreal-timeexecutionofverycomple8controlalgorithms,suchasadaptivecontrolandKalmanfilters.Veryhighsampl ingratescanalsobeusedtominimizeloopdelays.The‘240hasthearchitecturalfeaturesnecessaryforhigh-speedsignalp rocessinganddigitalcontrolfunctions,andithastheperipheralsneededtopro videasingle-chipsolutionformotorcontrolapplications.The‘240ismanufac turedusingsubmicronCMOStechnology,achievingalogpowerdissipationrating.A lsoincludedareseveralpower-downmodesforfurtherpowersavings.Someapplic ationsthatbenefitfromtheadvancedprocessingpowerofthe‘240include: ---Industrialmotordrives---Powerinvertersandcontrollers---Automotivesystems,suchaselectronicpowersteering,antilockbrake s,andclimatecontrol---ApplianceandHVACblower/compressormotorcontrols---Printers,copiers,andotherofficeproducts---Tapedrives,magneticopticaldrives,andothermassstorageproducts---RoboticandCNCmillingmachinesTofunctionasasystemmanager,aDSPmusthaverobuston-chipI/Oandotherp eripherals.Theeventmanagerofthe‘240isunlikeanyotheravailableonaDSP.T hisapplication-optimizedperipheralunit,coupledwiththehighperformanceD SPcore,enablestheuseofadvancedcontroltechniquesforhigh-precisionandhi gh-efficiencyfullvariable-speedcontrolofallmotortypes.Includeintheeve ntmanagerarespecialpulse-widthmodulation(PWM)generationfunctions,suchasaprogrammabledead-bandfunctionandaspacevectorPWMstatemachinefor3-ph asemotorsthatprovidesstate-of-the-artmaximumefficiencyintheswitchingo fpowertransistors.Thereindependentupdowntimers,eachwithit’sowncompareregister,sup portthegenerationofasymmetric(noncentered)aswellassymmetric(centered) PWMwaveforms.Open-LoopandClosed-LoopControlOpen-loopControlSystemsThewordautomaticimpliesthatthereisacertainamountofsophistication inthecontrolsystem.Byautomatic,itgenerallymeansThatthesystemisusually capableofadaptingtoavarietyofoperatingconditionsandisabletorespondtoa classofinputssatisfactorily.However,notanytypeofcontrolsystemhastheau ually,theautomaticfeatureisachievedbyfeed.gthefeedbackstructure,itiscalledanopen-loopsystem,whichisthesimp lestandmosteconomicaltypeofcontrolsystem.inaccuracyliesinthefactthato nemaynotknowtheexactcharacteristicsofthefurther,whichhasadefinitebear ingontheindoortemperature.Thisalcopointstoanimportantdisadvantageofth eperformanceofanopen-loopcontrolsystem,inthatthesystemisnotcapableofa daptingtovariationsinenvironmentalconitionsortoexternaldisturbances.I nthecaseofthefurnacecontrol,perhapsanexperiencedpersoncanprovidecontr olforacertaindesiredtemperatureinthehouse;butidthedoorsorwindowsareop enedorclosedintermittentlyduringtheoperatingperiod,thefinaltemperatureinsidethehousewillnotbeaccuratelyregulatedbytheopen-loopcontrol.Anelectricwashingmachineisanothertypicalexampleofanopen-loopsyst em,becausetheamountofwashtimeisentirelydeterminedbythejudgmentandesti mationofthehumanoperator.Atrueautomaticelectricwashingmachineshouldha vethemeansofcheckingthecleanlinessoftheclothescontinuouslyandturnitse dtoffwhenthedesireddegisedofcleanlinessisreached.Closed-LoopControlSystemsWhatismissingintheopen-loopcontrolsystemformoreaccurateandmoread aptablecontrolisalinkorfeedbackfromtheoutputtotheinputofthesystem.Ino rdertoobtainmoreaccuratebontrol,thecontrolledsignalc(t)mustbefedbacka ndcomparedwiththereferenceinput,andanactuatingsignalproportionaltothe differenceoftheoutputandtheinputmustbesentthroughthesystemtocorrectth eerror.Asystemwithoneormorefeedbackpat(slikethatjustdescribediscalled aclosed-loopsystem.humanbeingareprobablythemostcomplexandsophisticate dfeedbackcontrolsysteminexistence.Ahumanbeingmaybeconsideredtobeacont rolsystemwithmanyinputsandoutputs,capableofcarryingouthighlycomplexop erations.Toillustratethehumanbeingasafeedbackcontrolsystem,letusconsidert hattheobjectiveistoreachforanobjectonaperformthetask.Theeyesserveasas ensingdevicewhichfeedsbackcontinuouslythepositionofthehand.Thedistanc ebetweenthehandandtheobjectistheerror,whichiseventuallybroughttozeroa sthehandreachertheobject.Thisisatypicalexampleofclosed-loopcontrol.However,ifoneistoldtoreachfortheobjectandthenisblindolded,onecanonlyrea chtowardtheobjectbyestimatingitsexactposition.ItisAsantherillustrativ eexampleofaclosed-loopcontrolsystem,showstheblockdiagramoftherudderco ntrolsystemofThebasicalementsandtheblocadiagramofaclosed-loopcontrols ystemareshowninfig.Ingeneral,theconfigurationofafeedbackcontrolsystem maynotbeconstrainedtothatoffig&.Incomplexsystemstheremaybemultitudeof feedbackloopsandelementblocks.数控在先进制造技术领域最根本的观念之壹是数控(NC)。

数控加工工艺 外文文献

数控加工工艺  外文文献

英文原文CNC Machining ProcessFirst, our country's history of the development of numerical control system1. Our country since 1958, by a group of research institutes, colleges and universities and a few started to CNC Machine Tool Plant of the research and development system. At that time, due to the low level of domestic electronic components, such as the department of economic constraints, lack of a larger development.2. In the reform and opening up, China's numerical control technology gradually achieve substantial development. After "65" (81 ---- 85 years) the introduction of foreign technology, "75" (86 ------ 90 years) of the digestion and absorption and the "Eighth Five-Year Plan" (91 ~ 1 -95 years) National Organization of scientific and technological, that makes our country's CNC technology has a qualitative leap in acceptance at that time, through research and identification of country products including Beijing Everest's Chinese I, central China's central NC I and a few high-end Shenyang National Engineering Research Center for Control of Blue-I, as well as other through the "National Quality Supervision and Test Center machine" test NC system of qualified domestic companies such as Nanjing, four products.3. China's CNC machine tool manufacturing industry in the 80's had the stage of rapid development, many machine tool plant products from traditional products to the NC transition. But, generally speaking, the technological level is not high, the quality of the poor, so in the early 90's facing the country's economy from a planned economy to a market economy and adjust the transfer went through the most difficult years of the Depression period, the production capacity at that time down to 50 %, more than four month inventory. From 1995, "Ninth Five-Year Plan" to expand domestic demand from the country after the machine tool market to start, so as to reinforce the approval of imports of CNC equipment, investment focused on support for key numerical control system, equipment, technologies of CNC equipment has played a significant role, especially in 1999, the country's defense industry to civilian industry and the key to putting in a lot of technical department funds, to enable CNCequipment manufacturer market thriving. Three, CNC Technology and Equipment of cars cut CNC Lathe Machining Lathe technology and processing technology similar to, but because of CNC lathe is a fixture, for automatic processing of all finish turning process, which should pay attention to the following aspects.1. A reasonable selection cutting for the high-efficiency metal-cutting processing, the processed materials, cutting tools, cutting conditions is the three major elements. These determine the processing time, tool life and processing quality. Cost-effective processing methods must be a reasonable choice of the cutting conditions. Three elements of cutting conditions: cutting speed, feed rate and cutting depth of the damage directly caused by the tool. With the increase in cutting speed, tool tip temperature will rise; will have mechanical, chemical, thermal wear and tear. 20% increase in cutting speed; tool life will reduce the 1 /2. Feed conditions and the relationship between tool wear and tear at the back of a very small area of. However, the feed rate, cutting temperature rise, wear big behind. Than the impact of cutting speed on tool small. Depth of cut on the tools did not affect the cutting speed and feed rate, but at small cutting depth of cut when cutting materials have been hardened layer, which will affect the tool life. The user is processed according to the material, hardness, cutting status, material type, feed rate, cutting depth, such as the option of using the cutting speed. The most appropriate selections of processing conditions are at the basis of these factors is selected. Have rules, stability, worn and tear is to achieve the ideal conditions for life. However, in actual operation, the selection tool life and tool wear, the size of changes in processing, surface quality, cutting noise, heat processing and so on. In determining the processing conditions required to study the actual situation. The heat-resistant alloys such as stainless steel and hard materials, the coolant can be used best to use rigid blade.2. Reasonable selection tool1) when rough, it is necessary to choose high strength, good durability tool, in order to meet the rough knife when eating large back volume, the feed requirements.2) Fine car, it is necessary to choose high precision, durability good tool to ensure that the requirements of machining accuracy.3) In order to reduce tool change time and convenience of the knife should be used machines and machine folder knife blade.3. A reasonable selection Fixture1) General selection try the work piece clamping fixture to avoid the use of a dedicated fixture;2) positioning the base parts overlap so as to reduce the positioning error.4. To determine the processing routeprocessing route is the index-controlled machining process, tool parts relative trajectory and direction of Sports.1) Should be able to ensure the machining accuracy and surface roughness requirements;2) should try to shorten the processing route, reducing travel time and air knives.5. Processing route of contact with allowanceAt present, CNC lathes have not yet achieved the universal access to conditions, the general should be put on too much rough margin, especially with forging, casting hard cushion cortex in general lathe processing. Must be such as CNC lathe, the need to pay attention to process flexibility.6. Fixture to install the main pointsat present, the hydraulic clamping chuck and hydraulic cylinder are connected by the rod of the implementation, in Figure 1. Hydraulic clamping chuck as follows: First of all, by moving on hand to unload the nut hydraulic cylinder, the discharge of SLIDE, and back-end from the spindle out, and then move the hands to unload screw chuck can be disposed of under the chuck. Four, effectively turning a reasonable Save processing time Index Turning Center's G200 integrated processing unit with a modular, high-power two-axis linkage axis function, thus further shortening the processing time. With other means of job-axis opposite to the concept of clamping, the use of the product can be integrated intelligent processing unit in place so that the work piece clamping and automatic processing. In other words, the automatic setup will not be affected by the processing of another axis, a feature that can be shortened about 10% of the processing time. In addition, the Four processing very quickly, youcan simultaneously have two processing tool. When the machine is put into use in pairs, the efficiency becomes more apparent. In other words, the conventional hard turning and setting two cars can parallel machine. Turning conventional vehicles and hardware differences between the tool and focused only in the coolant system thermostat. However, conventional processing is different: both can be used conventional processing and a tool carrier for processing Tailstock; and hardware when using a tool only. In both types of machine tools can be carried out on the hard dry processing, only the manufacturer's technology program designed to balance the need to beat time, and Index of the module structure of machine tools to provide them with greater flexibility. To improve the productivity of high-precision with the continuous improvement of production efficiency, the user also made for a very high accuracy requirements. Turning Center G200 used for processing, the cold start up to four parts processing required to achieve tolerances of 卤6mm. Processing process, the accuracy is usually maintained at 2mm. Index so made available to the company's clients are high-precision, high efficiency, the integrity of the program, and programs to provide such high precision, requiring careful choice of spindle, bearings and other features. G200 Turning Center Landshut, Germany, BMW car factory in the application of the company achieved good results. The plant is not only the production of engines, but also by the production of cast light metal parts, plastic decorative items inside the vehicle and steering axis. Consider the quality of supervisory staff, and its very precise machining accuracy: tolerance bands for 卤15mm, for bearing tolerance 卤6.5mm. In addition, the processing of the universal joints of the Index companies use automatic intelligent processing unit. The first two parts are used for turning centers before playing pre-processing, post-processing line measurement, and then sent through the conveyor belt for hobbling, cleaning and quenching treatment. The last process using the second processing system Index. G200 Turning Center by two steering knuckle on the car bearing hard. In the machine tool to complete the online survey, then to the discharge unit. Processing unit fully integrated into the layout of the workshop, and in line with ergonomic requirements, covers an area of greatly reduced, and only two staff members to the custody ofmanufacturing cells. Friday, CNC turning and G00 in the magical effect of the skills to ensure dimensional accuracy CNC turning processing technology has been widely used in mechanical manufacturing industry, how efficient, reasonable, and completed by the quality of the work piece by the amount of processing, each engaged in the trade of engineering and technical personnel more or less have their own experience. I engaged in CNC teaching, training and processing for many years, accumulated a certain amount of experience and skills, is to CNC Equipment Factory Guangzhou GSK980T series of machine tool production, for example, introduce a few skills in CNC turning. First, the program first sentence skills G00 We now have access to textbooks and CNC turning technical books, procedures are set up the first sentence of work piece coordinate system, that is, G50 X,Z in the first sentence as a process. According to the directive, a coordinate system can be set so that the tool at a point in this coordinate system as coordinates (X, Z) (In this paper, the origin of work piece coordinate system are set at the right end of the work piece surface). Programming using this method, the knife, the knife must be moved to the established position of G50 can be set for processing, identify the location of the process is as follows.1. of a knife, the rough work piece clamping good;2. Spindle is to hand round the base right side knife flat work piece surface A;3. Z-axis fixed, the release of the tool along the X axis points to C, type G50 Z0, the point of computer memory;4. Program entry mode, type G01 W-8 F50, turning out to be one step work piece;5. X-axis fixed, the release of the tool along the Z-axis points to C, stop turning out measuring the diameter of the work piece level, the importation of G50 X, computer memory that point;6. Program entry mode, enter the G00 X伪Z尾, programming tool runs the specified procedure to the starting point, and then enter the G50 X,Z, procedures for the origin of the computer memory. The above-mentioned steps, the steps that the tool 6 at X,Z Office location is essential; otherwise, the work piece coordinate system will be modified, not the normal processing of the work piece. Processing has been theexperience of the people all know that the above position will be the tool to the cumbersome process of X,Z Department, in the event of an accident, X or Z-axis without servo, tracking error, power outages happen, etc., the system can restart, after restart system loss of G50 work piece coordinate values set by the memory, "reset back to zero run" is no longer working, will need to re-run the tool and reset to X,Z location G50. If it is production, processing, after the End of a return to the starting point for continued processing under the G50 is, in the process some errors on the work piece coordinate system may be modified. In view of the first sentence of the above procedures using G50 work piece coordinate system set up many defects, I will want to approach the work piece coordinate system fixed on the machine will process the first sentence changed to G50 X,Z after G00 X,Z, problem solved. The course of its operation only to find G50 using the above-mentioned five-step process before, that is, 1,2,3,4,5 steps to achieve, it will run the tool to a safe location, out of process, and can run automatically. Even if power outages and other unforeseen circumstances occur, restart the system, in the Edit mode to move the cursor without affecting the safe processing of the work piece processing process program segment, according to automate the processing can continue. First sentence of the above procedure to replace G50 with G00 is the substance of the work piece coordinate system fixed on the machine, no longer limited to the origin G50 X,Z process constraints, without changing the work piece coordinate system, easy operation, reliability, and received an unexpected effect. Chinese metal processing onlineSecond, control of dimensional accuracy skills1. To amend the value of a knife up to ensure dimensional accuracyFirst on the knife because of error or other causes beyond the work piece work piece error tolerance, can not meet the processing requirements, can be added by modifying the knife so that the work piece size to meet the requirement to ensure that the radial dimensions are as follows:a. absolute coordinate input methodAccording to the "big decrease, a small increase" principle, a knife up at 001 ~ 004 modified. Such as cut off on the 2nd slot at a big size work piece 0.1mm, and 002showed up knives are X3.8, may enter the X3.7, to reduce the knife on the 2nd meeting.b. the relative coordinate method as in the previous case, enter 002 knife fill U-0.1, also the same result.Similarly, the axial size of the control also and so on. Such as cylindrical with a knife on the 1st axis somewhere above processing, size, long 0.1mm, can be completed at 001 knife enter W0.1.2. Semi-finishing to ensure that the impact of the elimination of screw gap dimensional accuracyFor the majority of CNC lathe using a longer time, because of the effects of screw space and processing of the work piece dimensions are often unstable situation. At this time, we can rough after finishing a half-space to eliminate the effects of screw. 1, such as a knife with G71 cylindrical rough, you can fill in the 001 knife enter U0.3, call the G70 a fine car, parking measurements, and then fill in the 001 knife enter U-0.3, once again calling a G70 Finish . Finish a half after this time, eliminating the effects of screw clearance to ensure the stability of the dimensional accuracy.3. To ensure dimensional accuracy Programmer a. to ensure dimensional accuracy absolute programming there is an absolute and relative programming. Programming refers to the relative curve in the processing, the location of the end of the line segment to the starting point for the coordinates of the segment and to determine the origin of the coordinate system. In other words, programming is relatively often at the origin of the coordinates transform, continuous displacement is bound to result in a cumulative error, the absolute programming are in the processing of the whole process, have a relatively unified reference point, that is, coordinates of the origin, so the accumulated error over the relative Programming small. CNC turning work piece, the work piece precision radial dimension than the axial size of the general high precision, it is in the preparation of procedures, the use of the radial size of the absolute best programming, taking into account the processing and the convenience of programming, often used sizes of axial relative programming, but the essential axial size, the use of the absolute best programming.b. to ensure dimensional accuracy numerical conversionA lot of cases, the pattern on the size of the baseline and benchmark the size of the required programming inconsistent and should be first on the base pattern size coordinates converted to programming in size. Figure 2b, in addition to size of 13.06mm, the rest is marked directly by Figure 2a and size to be converted by the program size. One of,Φ29.95mm, Φ16mm and the three dimensions of 60.07mm respectively limit the size of two average size after the programming.4. Modify the program and control the size of premium knivesCNC Machining, we often encounter such a situation: the procedure to run automatically after stopping measurement and found that fail work piece size, size irregular Change. Such as a knife with 1 cylindrical work piece processing as shown in Figure 3, the post-roughing and semi-finishing parking measurements, the size of the radial axis paragraph as follows: Φ30.06mm, Φ23.03mm and Φ16.02mm. In this connection, I used a knife to amend the procedures and methods make up the remedy, as follows: a. modify the program X30 original program unchanged, X23 changed X23.03, X16 changed X16.04, As a result, are in excess of the shaft above the name of tolerance uniform size 0.06mm; b. knife to fill Knife on the 1st at 001 imported premium U-0.06. After these procedures and a two-pronged knife revised up, and then call the refined procedures, the general size of the work piece can be effectively guaranteed. CNC Turning CNC program is based on automated processing, the actual processing, and the operator only has a strong ability to use the program instructions and a wealth of practical skills in order to produce high-quality processing, processing high-quality work piece.Six, CNC machine tool troubleshooting methods and their attention to matters Missions usually take part in because of repair, some repair experience, combined with the relevant theories are described in the following list, to initiate. First, troubleshooting methods(1) initialization reset Law: Under normal circumstances, because of instantaneous alarm system failure can be hardware reset or system power switch in order to remove the fault, if the system is down because of the storage area, plug thecircuit board or battery less pressure lead to confusion, it must be clear to initialize the system, removing the former should pay attention to make copies of recorded data, if initialization can not be ruled out after the failure remains, were carried out in hardware diagnosis.(2) Parameters to change, actual procedures: system parameters are determined based on system functions, parameter settings may cause system errors or failures of a functional null and void. Sometimes, because of procedural errors can be caused by user downtime, this system can be used to block search function to check and correct all errors, in order to ensure its normal operation.(3) Regulation, the best method of adjustment: adjustment is one of the simplest ways. By adjusting the potentiometer to amend system failures. Repair such as in a factory, the system displays chaotic scene, with normal post-conditioning. Such as in a factory, the spindle brake at start-up and skidding when belt because of its large spindle load torque, and drives set the ramp-up time is too small, the normal post-conditioning. Optimize the system to adjust servo drive system with mechanical drag system the best way to match the General regulation, the approach is very simple, with a multi-line recorder or dual trace storage oscilloscope, respectively, observe instructions and the speed of feedback or response to the relationship between current feedback. By adjusting the ratio of the speed regulator factors and integration time to achieve servo system so that there are high dynamic response characteristics, but not the best job status oscillation. NOT at the scene of the oscilloscope or recorder circumstances, based on experience, that is, adjust so that the electrical start-up, and then slowly adjust to the reverse, until you can eliminate the shock.(4) spare parts to replace the Law: The best diagnosis of spare parts to replace bad circuit board, and start to do the initialization, so that the normal operation of machine tools quickly, and then repair or rework bad board, which is currently the most commonly used anti - approach it.(5) To improve the quality of the power law: the use of the existing power supply, to improve the power supply fluctuations. For high-frequency interference filteringcapacitor can be used by these preventive measures to reduce the power supply board failure.(6) Maintenance of information-tracking: some large manufacturing company based on actual work because of design defects caused by accidental failure, continuously modify and improve the system software or hardware. These changes to the form of constant repair information available to maintenance personnel. Used as the basis for troubleshooting can be completely right troubleshooting.Second, the repair should pay attention to matters(1) removed from a whole block on the circuit board, the Record should be noted that the relative position should be to connect the cable number, for fixed installation of the circuit board, it should be removed before and after the press-fit parts and screws for the record. Demolition under the pressure parts and screws should be placed on a dedicated box, so as to avoid loss, the assembly, the box should be all things to use, or incomplete assembly.(2) Electric iron should be placed on the front easily, away from the circuit board repair. Jerdonii Dressing should be appropriate in order to adapt to the welding circuit and to avoid bumps when welding other components.(3) Measuring the resistance between lines should be off the power, measured resistance should be measured the exchange of red and black table pen twice a year toa large value for the reference value.(4) Circuit board has solder brush most films, it should be measured to find the corresponding point of the solder joint as a test, not to eradicate the solder film, there is some insulation board all the brush layer, only in the spot with a blade scratch Department insulating layer.(5) Should not be arbitrarily cut off the printed circuit. Some maintenance personnel must have experience in repair of household appliances, used to check the line, but the numerical control equipment on the circuit boards are double-sided or multi-hole metal plate of plate, printing and dense fine-line, once cut off the hard welding, and easy to cut off tangent when the adjacent line, again some point, a cut off at one line, and should not make it and line out, need to do to cut off a few lines.(6) Should not be removed components. Some maintenance personnel to determine fault components in the absence of circumstances that is the seat of your pants a component breaks down, removed immediately, so that a higher rate of miscarriage of justice, human element removed have a higher failure rate.(7) Should be used to demolish suction devices and suction devices tin rope, should not have the hardware check. Long time heating pad should not be the same and repeat the demolition in order to avoid pad damage.(8) Replacement of the device, the pin should be the appropriate treatment, welding should not be used in welding acidic oil.(9) Record on the circuit switch, the jumper position, it should not be changed. Control for more than two inspections, or swap components on-board when the attention of the components of the tag in order to avoid confusion, which can not work well plate.中文译文数控加工工艺一,我国数控系统的发展史1.我国从1958年起,由一批科研院所,高等学校和少数机床厂起步进行数控系统的研制和开发。

关于数控车床编程外文文献翻译中英文翻译外文翻译

关于数控车床编程外文文献翻译中英文翻译外文翻译

关于数控车床编程外文文献翻译、中英文翻译、外文翻译英文原文On the NC latheCNC machine tool numerical control machine tools (Computer numerical control machine tools) abbreviation, is provided with a program control system of automatic machine tools. The logic control system can deal with the control code or other symbolic instruction specified program, and decoding the digital code, said information carrier, through the numerical control device input. After processing by CNC device control signals, control the machine movements, by drawing the shape and size requirements, will be automatically processed by the parts.Features: CNC machine tool operation and monitoring of all completed inthe numericalcontrol unit, it is the brain of CNC machine tools. Compared with the general machine tools, CNC machine tools has the following characteristics:● the processing object adaptability, adapt to the characteristics of mold products such as a single production, provide the appropriate processing method for die and mould manufacturing; ● high machining accuracy, processing with stable quality; ● can coordinate linkage, processing complex shape parts;● machining parts change, only need to change the program, can save the preparation time of production;● the machine itself high precision, rigidity, can choose the am ount of processing good, high productivity (3~5 times as common machine);The machine is a high degree of automation, reducing labor intensity;● conducive to the production management modernization. The use of CNC machine tools and the standard code of digital information processing, information transmission, the use of computer control method, has laid the foundation for the integration of computer aided design, manufacturing and management;● on the operators of higher quality, higher demands for the repair ofthe technical staff;● high reliability.Composition: CNC machine tools in general by the input medium, man-machine interactive equipment, CNC equipment, feed servo drive system, spindle servo drive system, the auxiliary control device, feedback apparatus and adaptive control device etc.. [4] in NC machining, NC milling processing is the most complex, need to solve most problems. NC programming of NC line in addition to CNC milling, cutting, CNC EDM, CNC lathe, CNC grinding, each with its own characteristics, servo system is the role of the motion signal is convertedinto the machine moving parts from the numerical control device of pulse. Concrete has the following parts: the structure of CNC machine tools.Driver: he is driving parts of CNC machine tools, actuator, including spindle drive unit, feeding unit, spindle motor and feed motor. He through the electric or electro-hydraulic servo system to realize the spindle and feeddrive under the control of numerical control device. When several feed linkage, can complete the positioning, processing line, plane curve and space curve.The main performance (1) the main dimensions. (2) the spindle system. (3) feed system. (4) tool system.(5) electrical. Including the main motor, servo motor specifications and power etc.. (6) cooling system. Including the cooling capacity, cooling pump output. (7) dimensions. Expressed as length * width * height.Development trend of CNC lathe:High speed, precision, complex, intelligent and green is the general trend in the development of CNC machine tool technology, in recent years, made gratifying achievements in practicality and industrialization. Mainly in the:1 machine tool composite technology to further expand with the CNC machine tool technology, composite processing technology matures, including milling - car compound, car millingcompound, car - boring - drill - gear cutting compound, composite grinding, forming, composite processing, precision and efficiency of machining isgreatly improved. \processing factory\the development of compound processing machine tool is the trend of diversified.Intelligent technology 2 CNC machine tools have a new breakthrough, in the performance of NC system has been reflected more. Such as: automaticallyadjust the interference anti-collision function, after the power of workpiece automatically exit safety power-off protection function, machining parts detection and automatic compensation function of learning, high precisionmachining parts intelligent parameter selection function, process automatic elimination of machine vibration functions into the practical stage, intelligent upgrade the function of machine and quality.The 3 robots enable flexible combination of flexible combination of higher efficiency of robot and the host are widely used, make flexible line more flexible, extending the function, flexible line shorten further, more efficient. Robot and machining center, milling composite machine, grinder, gear processing machine tool, tool grinding machine, electric machine, sawing machine, punching machine, laser cutting machine, water cutting machine etc. various forms of flexible unit and flexible production line has already begun the application.4 precision machining technology has the machining precision of CNC metal cutting machine tools from the yarn in the original (0.01mm) up to micronlevel (0.001mm), some varieties has reached about 0.05 μ M. Micro cutting and grinding machining of ultra precision CNC machine tools, precision can reach about 0.05 μ m, shape precision can reach about 0.01 μ M. Special processing precision by using optical, electrical, chemical, energy can reach nanometer level (0.001 μ m). By optimizing the design of machine tool structure, machine tool parts of ultra precision machining and precision assembly, using high precision closed loop control andtemperature, vibration and other dynamic error compensation technology, improve the geometric accuracy of machine tool processing, reduce the shape of error, surface roughness, and into the submicron, nano super finishing tiThe 5 functional component to improve the performance of functional components are at a high speed, high precision, high power and intelligent direction, and obtain the mature application. A full digital AC servo motor and drive device, high technology content of the electric spindle, linear motor, torque motor, linear motion components with high performance, application of high precision spindle unit and other function parts, greatly improving the technical level of CNC machine tools.The feed drive system of CNC lathe: Effect of feed drive system,The feed drive system of CNC machine tools will be received pulse command issued by the numerical control system, and the amplification and conversion machine movements carry the expected movement.Two, the feeding transmission system requirementsIn order to guarantee the machining accuracy of NC machine tool is high,the feed drive system of transmission accuracy, sensitivity high (fast response), stable work, high stiffness and friction and inertia small, service life, and can remove the transmission gap. Category three, feed drive system 1, stepping motor servo system Generally used for NC machine tools. 2, DC servo motor servo systemPower is stable, but because of the brush, the wear resulting in use needto change. Generally used for middle-grade CNC machine tools. 3, AC servomotor servo systemThe application is extremely widespread, mainly used in high-end CNC machine tools. 4, the linear motor servo systemNo intermediate transmission chain, high precision, the feed speed, no length limit; but the poor heat dissipation, protection requirements are particularly high, mainly used for high-speed machine.Driving component four, feed system 1, the ball screw nut pairNC machining, the rotary motion into linear motion, so the use of screwnut transmissionmechanism. NC machine tools are commonly used on the ball screw, as shownin Figure 1-25, it can be a sliding friction into rolling friction, meet the basic requirements of the feed system to reduce friction. The transmissionside of high efficiency, small friction, and can eliminate the gap, no reverse air travel; but the manufacturing cost is high, can not lock, size is not too big, generally used for linear feed in small CNC machine tool. 2, rotary tableIn order to expand the scope of the process of NC machine tools, CNC machine tools in addition to make linear feed along the X, Y, Z three coordinate axes, often also need a circumferential feed movement around Y or Z axis. Circular feed motion of CNC machine tools in general by the rotary table to realize, for machining center, rotary table has become an indispensablepart of. Rotary table of commonly used CNC machine tools in the indexing table and NC rotary table. (1) indexing tableIndexing table can only finish dividing movement, not circular feed, it is in accordance with the instructions in the NC system, when indexing will work together with the workpiece rotation angle. When indexing can also use manual indexing. Provisions of indexing table is generally only rotary angle (such as 90, 60 and 45 degree). (2) NC rotary tableNC rotary table appearance similar to the indexing table, but the internal structure and function is not the same. The main function of the NC rotary table is based on the numerical control device sends command pulse signal, complete circumferential feed movement, various arc processing and surface processing, it can also be graduation work. 3, guideRail is an important part of feed drive system, is one of the basic elements of the structure of machine tool, rigidity, precision and accuracy of NC machine tool which determines to a large extent retention. At present, guide the NC machine tool are sliding rail, rolling guideway and hydrostatic guideway. (1) sliding guideSliding guide rail has the advantages of simple structure, easy manufacture, good stiffness, vibration resistance and high performance, widely used in CNC machine tools, the use of most metal plastic form, known as the plastic guide rail, as shown in figure 1-26.On characteristics of the plastic sliding guide: friction characteristicis good, good wear resistance, stable movement, good manufacturability, low speed. (2) rolling guideRolling guide is placed in the rail surface between the ball, roller or needle roller, roller, the rolling friction instead of sliding surface of the guide rail between wipe.Rolling guide rail and the sliding rail, high sensitivity, small friction coefficient, and the dynamic, static friction coefficient is very small, so the motion is uniform, especially in the low speed movement, the stick-slip phenomenon is not easy to occur; high positioning accuracy,repeatability positioning accuracy is up to 0.2 μ m; traction force is small, wear small, portable in movement; good precision, long service life. But the vibration of rolling guide, high requirements on protection, complicated structure, difficult manufacture, high cost.Automatic tool changer:One, the function of automatic tool changerAutomatic tool changing device can help save the auxiliary time of CNC machine tools, and meet in an installation completed procedure, stepprocessing requirements. Two, on the requirement of automatic tool changerNumerical control machine tool for automatic tool changer requirement is: tool change quickly, time is short, high repetitive positioning accuracy, tool storage capacity is sufficient, small occupation space, stable and reliable work. Three, change the knife form 1, rotary cutter replacementIts structure is similar to the ordinary lathe turret saddle, according to the processing of different objects can be designed into square or six angle form, consists of the NC system sends out the instruction to the rotary cutter.2, the replacement of the spindle head tool changeThe spindle head pre-loaded required tools, in order to machining position, the main motor is switched on, drives the cutter to rotate. The advantage of this method is that eliminates the need for automatic clamping, cutting tool, clamping and cutting tool moving and a series of complex operation, reducetool change time, improve The ATC reliability. 3, the use of changing toolThe processing required tools are respectively arranged in the standard tool, adjust the size of the machine after certain way add to the knife, the exchange device from the knife and the spindle take knife switch.感谢您的阅读,祝您生活愉快。

数控技术类外文文献翻译、中英文翻译、外文翻译

数控技术类外文文献翻译、中英文翻译、外文翻译

外文原文:NC Technology1、Research current situation of NC lathe in our timesResearch and development process to such various kinds of new technologies as numerical control lathe , machining center , FMS , CIMS ,etc. of countries all over the world, linked to with the international economic situation closely. The machine tool industry has international economy to mutually promote and develop, enter 21 alert eras of World Affairs, the function that people's knowledge plays is more outstanding, and the machine tool industry is regarded as the foundation of the manufacturing industry of the machine, its key position and strategic meaning are more obvious. Within 1991-1994 years, the economic recession of the world, expensive FMS, CIMS lowers the temperature, among 1995-2000 years, the international economy increases at a low speed, according to requisition for NC lathe and the world four major international lathes exhibition in order to boost productivity of users of various fields of present world market (EMO , IMTS , JIMTOF , China CIMT of Japan of U.S.A. of Europe), have the analysis of the exhibit, there are the following several points mainly in the technical research of NC lathe in our times:(1)、Pay more attention to new technology and innovationWorldwide , are launching the new craft , new material , new structure , new unit , research and development of the new component in a more cost-effective manner, developmental research of for instance new cutter material , the new electric main shaft of main shaft structure , high speed , high-speed straight line electrical machinery ,etc.. Regard innovating in improvement of the processing technology as the foundation, for process ultra and hard difficult to cut material and special composite and complicated part , irregular curved surface ,etc. research and develop new lathe variety constantly.(2)、Improve the precision and research of machine toolingIn order to improve the machining accuracy of the machining center, are improving rigidity of the lathe, reduction vibration constantly, dispel hotly and out of shape, reduce the noise , improve the precision of localization of NC lathe, repeat precision, working dependability , stability , precision keeping, world a lot of country carry on lathe hot error , lathe sport and load out of shape software of error compensate technical research, take precision compensate, software compensate measure improve , some may make this kind of error dispel 60% already. And is developing retrofit constantly, nanometer is being processed.(3)、Improve the research of the machine tooling productivityWorld NC lathe, machining center and corresponding some development of main shaft, electrical machinery of straight line, measuring system, NC system of high speed, under the prerequisite of boosting productivity.(4)、What a lot of countries have already begun to the numerical control system melt intelligently, openly, study networkedlyA、Intelligent research of the numerical control systemMainly showing in the following aspects: It is intelligent in order to pursue the efficiency of processing and process quality, the self-adaptation to the processing course is controlled, the craft parameter produces research automatically; Join the convenient one in order to improve the performance of urging and use intelligently, to the feedback control, adaptive operation , discerning automatically load selects models automatically, since carries on research whole definitely ,etc. of the electrical machinery parameter; There are such research of the respect as intelligent automatic programming , intelligent man-machine interface , intelligence diagnosing , intelligent monitoring ,etc..B、The numerical control system melts and studies openMainly showing in the following aspects: The development of the numerical control system is on unified operation platform, face the lathe producer and support finally, through changing, increasing or cutting out the structure target(numerical control target ), form the seriation, and can use users specially conveniently and the technical know-how is integrated in the control system, realize the open numerical control system of different variety, different grade fast, form leading brand products with distinct distinction. System structure norm of the open numerical control system at present, norm, disposing the norm, operation platform, numerical control systematic function storehouse and numerical control systematic function software developing instrument, etc. are the core of present research to pass through.C、Meeting the manufacture system of the production line , demand for the information integration of the manufacturing company networkedly greatly of numerical control equipment, it is a basic unit of realizing the new manufacture mode too.2、Classification of the machining center(1)Process according to main shaft space position when it classifies to be as follows, horizontal and vertical machining center.Horizontal machining center, refer to the machining center that the axis level of the main shaft is set up. Horizontal machining center for 3-5 sport coordinate axis, acommon one three rectilinear motion coordinate axis and one turn the coordinate axis of sports round (turn the working bench round), it can one is it is it finish other 4 Taxi processing besides installing surfaces and top surfaces to insert to install in work piece, most suitable for processing the case body work piece. Compared with strength type machining center it, the structure is complicated, the floor space is large, quality is large, the price is high.Vertical machining center, the axis of the main shaft of the vertical machining center, in order to set up vertically, its structure is mostly the regular post type, the working bench is suitable for processing parts for the slippery one of cross, have 3 rectilinear motion coordinate axis generally, can find a room for one horizontal numerical control revolving stage (the 4th axle) of axle process the spiral part at working bench. The vertical machining center is of simple structure, the floor space is small, the price is low, after allocating various kinds of enclosures, can carry on the processing of most work pieces.Large-scale gantry machining center, the main shafts are mostly set up vertically, is especially used in the large-scale or with complicated form work piece , is it spend the many coordinate gantry machining center to need like aviation , aerospace industry , some processing of part of large-scale steam turbine.Five machining centers, this kind of machining center has function of the vertical and horizontal machining center, one is it after inserting, can finish all five Taxi processing besides installing the surface to install in work piece, the processing way can make form of work piece error lowest, save 2 times install and insert working, thus improve production efficiency, reduce the process cost.(2)Classify by craft useIs it mill machining center to bore, is it mill for vertical door frame machining center, horizontal door frame mill the machining center and Longmen door frame mill the machining center to divide into. Processing technology its rely mainly on the fact that the door frame is milled, used in case body, shell and various kinds of complicated part special curve and large processes , curved surface of outline process, suitable for many varieties to produce in batches small.Complex machining center, point five times and compound and process mainly, the main shaft head can be turned round automatically, stand, lie and process, after the main shaft is turned round automatically, realize knowing that varies in the horizontal and vertical direction.(3)Classify by special functionSingle working bench, a pair of working bench machining center;Single axle, dual axle, three axle can change machining center, main shaft of case;Transfer vertically to the tower machining center and transfer;One hundred sheets of storehouses adds the main shaft and changes one one hundred sheets of machining centers;One hundred sheets of storehouses connects and writes hands to add the main shaft and change one hundred sheets of machining centers;One hundred sheets of storehouses adds the manipulator and adds one pair of main shafts to transfer to the tower machining center.3、Development trend of the current numerical control latheAt present, the advanced manufacturing technology in the world is rising constantly, such application of technology as ultrafast cutting , ultraprecision processing ,etc., the rapid development of the flexible manufacturing system and integrated system of the computer one is constant and ripe, have put forward higher demand to the process technology of numerical control. Nowadays the numerical control lathe is being developed in several following directions.(1). The speed and precision at a high speed , high accuracy are two important indexes of the numerical control lathe, it concerns directly that processes efficiency and product quality. At present, numerical control system adopt-figure number, frequency high processor, in order to raise basic operation speed of system. Meanwhile, adopt the super large-scale integrated circuit and many microprocessors structure, in order to improve systematic data processing ability, namely improve and insert the speed and precision of mending operation. Adopt the straight line motor and urge the straight line of the lathe working bench to be servo to enter to the way directly, it is quite superior that its responds the characteristic at a high speed and dynamically. Adopt feedforward control technology, make it lag behind error reduce greatly, thus improve the machining accuracy cut in corner not to track.For meet ultrafast demand that process, numerical control lathe adopt main shaft motor and lathe structure form that main shaft unite two into one, realize frequency conversion motor and lathe main shaft integrate , bearing , main shaft of electrical machinery adopt magnetism float the bearing , liquid sound pigeonhole such forms as the bearing or the ceramic rolling bearing ,etc.. At present, ceramic cutter and diamond coating cutter have already begun to get application.(2). Multi-functional to is it change all kinds of machining centers of organization (a of capacity of storehouse can up to 100 of the above ) automatically tofurnished with, can realize milling paring , boring and pares , bores such many kinds of processes as paring , turning , reaming , reaming , attacking whorl ,etc. to process at the same time on the same lathe , modern numerical control lathe adopt many main shaft , polyhedron cut also , carry on different cutting of way process to one different position of part at the same time. The numerical control system has because adopted many CPU structure and cuts off the control method in grades, can work out part processing and procedure at the same time on a lathe, realize so-called "the front desk processes, the backstage supporter is an editor ". In order to meet the needs of integrating the systematic one in flexible manufacturing system and computer, numerical control system have remote serial interface , can network , realize data communication , numerical control of lathe, can control many numerical control lathes directly too.(3). Intelligent modern numerical control lathe introduce the adaptive control technology, according to cutting the change of the condition, automatic working parameter, make the processing course can keep the best working state , thus get the higher machining accuracy and roughness of smaller surface , can improve the service life of the cutter and production efficiency of the equipment at the same time . Diagnose by oneself, repair the function by oneself, among the whole working state, the system is diagnosed, checked by oneself to CNC system and various kinds of equipment linking to each other with it at any time. While breaking down, adopt the measure of shutting down etc. immediately, carry on the fault alarm, brief on position, reason to break down, etc.. Can also make trouble module person who take off automatically, put through reserve module ,so as to ensure nobody demand of working environment. For realize high trouble diagnose that requires, its development trend adopts the artificial intelligence expert to diagnose the system.(4).Numerical control programming automation with the development of application technology of the computer, CAD/CAM figure interactive automatic programming has already get more application at present, it is a new trend of the technical development of numerical control. It utilize part that CAD draw process pattern , is it calculate the trailing punishing to go on by cutter orbit data of computer and then, thus produce NC part and process the procedure automatically, in order to realize the integration of CAD and CAM. With the development of CIMS technology , the full-automatic programming way in which CAD/CAPP/CAM integrates has appeared again at present, it, and CAD/CAM systematic programming great differencetheir programming necessary processing technology parameter needn't by artificial to participate in most, get from CAPP database in system directly.(5). The dependability of the dependability maximization numerical control lathe has been the major indicator that users cared about most all the time. The numerical control system will adopt the circuit chip of higher integrated level, will utilize the extensive or super large-scale special-purpose and composite integrated circuit, in order to reduce the quantity of the components and parts, to improve dependability. Through the function software of the hardware, in order to meet various kinds of demands for controlling the function, adopt the module, standardization, universalization and seriation of the structure lathe noumenon of the hardware at the same time, make not only improve the production lot of the hardware but also easy to is it produce to organize and quality check on. Still through operating and starting many kinds of diagnostic programs of diagnosing, diagnosing, diagnosing off-line online etc. automatically, realize that diagnoses and reports to the police the trouble to hardware, software and various kinds of outside equipment in the system. Utilize the warning suggestion, fix a breakdown in time; Utilize fault-tolerant technology, adopt and design the important part " redundantly ", in order to realize the trouble resumes by oneself; Utilize various kinds of test, control technology, excess of stroke, knife damages, interfering, cutting out, etc. at the time of various kinds of accidents as production, carry on corresponding protection automatically.(6). Control system miniaturization systematic miniaturization of numerical control benefit and combine the machine, electric device for an organic whole. Adopt the super large-scale integrated component , multi-layer printed circuit board mainly at present, adopt the three-dimensional installation method , make the electronic devices and components must use the high density to install, narrow systematic occupying the space on a larger scale. And utilize the new-type slim display of colored liquid crystal to substitute the traditional cathode ray tube, will make the operating system of numerical control miniaturize further. So can install it on the machine tool conveniently, benefit the operation of the numerical control lathe correctly even more.本文出自:Shigley J E. Mechanical Engineering Design. New York: McGraw-Hill, 1998译文:数控技术1、当前世界NC机床的研究现状世界各国对数控机床、加工中心以至FMS、CIMS等各种新技术的研究与发展进程,是与世界经济形势紧密相连的。

机床刀具设计机械类毕业设计外文文献翻译中英文翻译

机床刀具设计机械类毕业设计外文文献翻译中英文翻译

英语原文:Design Of Tool Machine PropResearch significanceThe original knife machine control procedures are designed individually, not used tool management system, features a single comparison, the knife only has to find the tool knife, knife positioning the shortest path, axis tool change, but does not support large-scale tool.Automatic knife in the knife election, in the computer memory knife-election on the basis of using the Siemens 840 D features, and the election procedures knife more concise, and complete the space Daotao View. ATC use the knife rapid completion of STEP-7 programming, and have been tested in practice. In the positioning of the knife, PLC controlled modular design method, which future production of similar machines will be very beneficial, it is easy to use its other machine. Automatic tool change systems will be faster growth, reduced tool change time, increase the positioning accuracy tool is an important means to help NC technology development.Tool and inventory components of modern production is an important link in the management, especially for large workshop management. The traditional way of account management, and low efficiency, high error rate, and not sharing information and data, tools and the use of state can not track the life cycle, are unable to meet the current information management needs. With actual production, we have to establish a workshop tool for the three-dimensional tool storage system to meet the knife workshop with auxiliary storage and management needs.The system uses optimization technology, a large number of computer storage inventory information, timely, accurate, and comprehensive tool to reflect the inventory situation. The entire system uses a graphical interface, man-machine dialogue tips from the Chinese menu, select various functions can be realized and the importation of all kinds of information. Management system using online help function. Through the workshop management, network management and sharing of information. Have automated inventory management, warehousing management tool, a tool for the management and statistical functions.1.System components and control structureThe entire system, including the structure and electrical machinery control systems.1.1.1Mechanical structure and working principleTool from the stent, drive, drive system, Turret, shielding, control system, and electrical components. Support from the column, beam, the upper and lower guide Central track, and track support component.1) Drive for the system chosen VVVF method. Cone used brake motors, with VVVF by Cycloidreducer through sprocket drive.2) Drag a variable frequency drive system and control technology. VVVF adopted, will speed drive shaft in the normal range adjustment to control the speed rotary turret to 5 ~ 30mm in, the drive shaft into two, two under through sprocket, the two profiled rollers Chain driven rotating shelves. Expansion chain adopted by the thread tight regulation swelling, swelling the regular way. - Conditioned, under the same chain-of-conditioning, so that the chain of uniform.3) Turret and shields the entire total of 14 independent Turret. 13 of them as a socket-Turret, as a drawer-Turret, each Turret back through the pin and, under the conveyor chain link chain plate, installed at the bottom roller, chain driven rotating turret rotation along the track. Outlet-Turret and BT50-BT40 Turret Turret two kinds of forms. To strengthen management, security, landscaping modeling, shelf peripherals and shields. Turret-drawer drawer placed at six other Des V oeux a knife, can be categorized with some of knife auxiliary equipment, such as bits, such as turning tools.1.1.2.Electrical Control SystemThis tool storage systems is the main electrical control their shelves for operational control and position control. Operational control equipment, including operation of the start of braking control. Position Control is the main location and address of the shelves for testing. Control system as shown in Figure 1.图 1 Tool Control System for the1) Electric Transmission horizontal rotary tool storage systems are the mechanical movements are repeated short-term work system. And the run-time system needs some speed, speed transmission needs, the system will use VVVF method can be used simple structure, reliable operation of the motor and frequency inverter.2) Control of the system is divided into two kinds of manual control and automatic control, manual control as a general reserve and debugging methods of work; ways to the system control computer (IPC) and the control unit (inverter contactor , etc.) consisting of a control system.3) location and positioning accuracy of the system automatically identify the site and location using a detection device as proximity switches, relays through the plate-point isolation and the number plate recorded close to the switching signal acquisition and operation of Hutchison with a Optimal Path addressable identify the current location and shelves of the purpose of the shelf location. In order to enable a more accurate positioning system, adopted two photoelectric switches, to detect the two shelves of the two films.1.2.The functions of the knifeknife The is the role of reserves a certain number of tools, machine tool spindle in hand to achieve the fungibility a disc cutter knife is the type of library, the chain knives, and other means, in the form of the knife and capacity according to the Machine Tool to determine the scope of the process.mon typesThe knife is a tool storage devices, the common knife mainly in the following forms:(1) the turret knifeIncluding the first level turret vertical turret and the first two, see Figure 2.6 a) and b):(2) the disc cutterDisc knife in the library with discoid knife, cutting tool along See how vertical arrangement (including radial and axial from knife from knife), along See how radial array into acute or arranged in the form of the knife. Simple, compact, more applications, but are ring-cutter, low utilization of space. Figure 2.7 a) to c). If the knife storage capacity must be increased to increase the diameter of the knife, then the moment of inertia also increased correspondingly, the election campaign long knife. Tool number not more than 32 general. Cutter was multi-loop order of the space utilization knife, but inevitably given the knife from complex institutions,applicable to the restricted space Machine Tool storage capacity and more occasions. Two-disc structure is two smaller capacity knife on both sides of the sub-spindle place, more compactlayout, the number of certificates corresponding increase knife, apply to small and medium-sized processing center.(3) the chain knifeIncluding single-and multi-ring chain ring chain, chain link can take many forms change, see Figure 2.8 a) to c), thebasic structure shown inFigure 2. 8 doFeatures: knife apply tothe larger capacity of theoccasion, the space of thesmall number ofgenerally applicable tothe tool in the 30-120.Only increase the lengthof the chain tool will increase the number should not be increased circumferential speed of itsmoment of inertia of the knife does not increase the disc as large.(4) linear combination knife and the knife libraryThe linear knife simple structure in Figure 2.9, tool single order, the capacity of small knife, used for CNC lathe and drill press on. Because the location of fixed knife, ATC completed action by the spindle without manipulator. The cutter knife is generally the turret combination turret with a combination of the disc cutter knife and the chain combination. Every single knife the knife certificates of smaller, faster tool change. There are also some intensive drum wheel, and the lattice-type magazine for the knife, the knife-intensive though. Small footprint, but because of structural constraints, basically not used for single processing center, the concentration used for FMS for the knife system.1.4 Tool storage capacityTool storage capacity of the first to consider the needs of processing, from the use of point of view, generally 10 to 40 knives, knife will be the utilization of the high, and the structure iscompact.1.5 Tool options(1) choose to order processing tool according to the order, followed Add to the knife every knife in the Block. Each tool change, the order of rotation of a cutter knife on location, and remove the need knives, has been used by the cutter knife can be returned to the original Block, can also order Add Block, a knife. However, as the knife in the tool in different processes can not be repeated use of the knife must increase the capacity and lower utilization rate.(2) most of the arbitrary choice of the current system of using arbitrary NC election knives, divided into Daotao coding, coding and memory-cutter, three. Daotao coding tool code or knives or Daotao need to install the code used to identify, in accordance with the general principle of binary coding coding. Tool knife election coding method uses a special knife handle structure, and each of the coding tool. Each of the tool has its own code, thereby cutting tool can be in different processes repeatedly used, not to replace the tool back at the original knife, the knife capacity can be reduced accordingly. Memory-election this paper knife, in this way can knives and knife in the position corresponding to the Daotao memory of the PLC in the NC system, no matter which tool on the Inner knife, tool information is always there in mind, PLC . On the knife with position detection devices, will be the location of each Daotao. This tool can be removed and sent back to arbitrary. On the knife is also a mechanical origin, every election, the nearest knife selection.1.6.Control of the knife(1) the knife as a system to control the positioning axis. In the ladder diagram in accordance with the instructions for computing T code comparison of the output angle and speed of instructions to the knife the knife servo drive servo motor. Tool storage capacity, rotation speed, and / deceleration time, and other system parameters can be set in such a manner free from any outside influence positioning accurate and reliable but the cost is higher.(2) knife from the hydraulic motor drives, fast / slow the points, with proximity switches count and positioning. In comparison ladder diagram of the current storage system knife (knife spindle) and goals knife (pre-knife) and computing, then output rotation instructions, judging by the shortest path rotation in place. This approach requires sufficient hydraulic power and electromagnetic valve knife the rotational speed can be adjusted through the throttle. But over time may be oily hydraulic, oil temperature and environmental factors impact the change in velocity and accuracy. Not generally used in large and medium-sized machine tool change frequently.(3) the knife from AC asynchronous motor driven cam mechanism (Markov institutions), with proximity switches count, which means stable operation, and generally accurate and reliablepositioning cam used in conjunction with a mechanical hand, A TC fast-positioning.2. ATC, the main types, characteristics, and the scope of application 2.1 Auto Rotary ToolRotary Tool automatically onthe use of CNC machine tool is asimple installation of automatic toolchange, the Quartet and 47.60 TurretTool various forms, such as rotaryturret were installed on four, six ormore of the Tool , NC instructions byATC. Rotary Tool has two verticaland horizontal, relatively simplestructure, applicable to economicCNC lathe.Rotary Tool in the structure musthave good strength and stiffness,resistance to bear rough Cutting Toolin the cutting force and reduce therole of deformation and improveprocessing accuracy. Rotating Toolto choose reliable positioningprogramme structure and reasonable position, in order to ensure that each rotary turret to a higher position after repeated positioning accuracy (typically 0.001 to 0.005mm). Figure 2.1 shows the spiral movements of the Quartet Turret.Auto Rotary Tool in the simplest of ATC, is 180 º rotary ATC devices, as shown in Figure 2.2 ATC instructions received, the machine control system put ATC spindle control to the designated location at the same time, the tool movement to the appropriate location, ATC, with the rotary axis and at the same time, the knives matching tool; drawbars from Spindle Cutting Tools rip, ATC, will be the tool from their position removed; ATC, 180 º rotary tool spindle and the tool and tool away; A TC, the Rotary At the same time, the tool refocusing its position to accept Spindle removed from the cutting tool; Next, ATC, will be replaced with the cutter knives were unloaded into the spindle and tool: Finally, back to the original ATC, "standby" position. At this point, ATC completed procedures to continue to run. This ATC, the main advantage ofsimple structure, the less movement, fast tool change. The main disadvantage is that knives must be kept in parallel with the axis of the plane, and after the home side compared to the tool, chip and liquid-cutting knife into the folder, it is necessary to the tool plus protection. Cone knife folder on the chip will cause A TC error, or even damage knife folders, and the possibility of spindle. Some processing centre at the transfer, and the tool side. When the ATC command is called, the transfer-cutter knives will be removed, the machine go forward, and positioning with the ATC, in line with the position. 180 º "Rotary ATC devices can be used horizontal machine, can also be used for vertical machining centers.2. 2 ATC head-turret installedWith rotating CNC machine tool often used such ATC devices, with a few turret head spindle, each with a spindle on both knives, the first tower interim process can be automatic tool change-realization. The advantage is simple structure, tool change time is short, only about 2 s. However, due to spatial constraints, the number of spindle can not be too much, usually only apply to processes less, not to high precision machine tools, such as the NC drill, such as CNC milling machine. In recent years there has been a mechanical hand and the turret head with a knife for the automatic tool change ATC devices, as shown in Figure 2.3. It is in fact a turret head ATC, and the knife-ATC device combination. The principle is as follows:5 turret on the first two tool spindle 3 and 4, when using the tool spindle 4 processing tool, the manipulator 2 will be the next step to the need for the tool does not work on the tool spindle 3 until after the completion of this process , the first rotary turret 180 º, A TC completed. ATC most of their time and processing time coincidence, the only real tool change time turret transposition of the first time, this approach mainly used for ATC and NC NC drilling file bed. 2. 3.Daidao system for the automatic tool changeFigure 2.4 shows the knife and the whole machine tool CNC machine tools for the appearance of Fig.Figure 2.5 shows the knife and split-type machine to the appearance of CNC machine tool plans.At this point, knife storage capacity, a heavier tool can, and often additional transport unit to complete the knife between the spindle and cutting tool transport.Daidao the knife from the ATC, the election knives, automatic loading and unloading machine tool and tool exchange institutions (manipulator), composed of four parts, used widely.Tool Automatic Tool Change the manipulator system, the whole process more complicated ATC. We must first used in the processing of all installed in the standard tool on the knife handle in the machine outside the pre-size, according to a certain way Add to the knife. ATC, selected first in the knife knife, and then from ATC, from the knife from the knife or spindle, exchange, the new knife into the spindle, the old knife back into the knife.ATC, as the former two knives to accommodate a limited number can not be too many, can notmeet the needs of complex parts machining, CNC machine tool Automatic Tool Change Daidao the use of the automatic tool change devices. The knife has more capacity, both installed in the spindle box side or above. As for the automatic tool change Daidao device CNC machine tool spindle box only a spindle, spindle components to high stiffness to meet the machining requirements. The number of establishments in larger knife, which can meet the more complex parts of the machining processes, significantly improving productivity. Daidao system for the automatic tool change applied to drilling centres and CNC machining centers. The comparison drawn Daidao automatic tool change system is the most promising.3.PLC control of the knife random mode of election3. 1Common methods of automatic election knifeAutomatic control of the knife CNC refers to the system after the implementation of user instructions on the knife library automation process, including the process to find knives and automatic tool change [(63,71]. CNC Machining Center device (CNC) directive issued by the election knife , a knife, the tool required to take the knife position, said the election automatic knife. automatically elected knife There are two ways: random sequence election knives and knife election method.3.1.1 order election knifeTool Selection order is the process tool according to the sequence of the insert knife, the use of knives in order to take place, used knives back at the original knife, can also order Add Block, a knife. In this way, no need Tool identification devices, and drive control is a relatively simple, reliable and can be used directly from the points of the knife machinery to achieve. But the knives in each of the tool in different processes can not be reused, if the tool is installed in accordance with the order of the knife, there will be serious consequences. The need to increase the number of knives and knife the capacity of the tool and reduce the utilization of the knife.3.1.2Random election knifeRandom election under the knife is arbitrary instructions to select the required tools, then there must be tool identification devices. Tool knife in the library do not have the processing in accordance with the order of the workpiece can be arbitrary storage. Each of the tool (or knifeblocks) are for a code, automatic tool change, the rotary cutter, every tool have been the "tool identification device" acceptable identification. When CNC tool code and the code in line with directives of the tool selected, the rotary cutter knives will be sent to the ATC position, waiting to grab manipulator. Random knife election is the advantage of the cutter knife in the order has nothing to do with the processing sequence, the same tool can be used repeatedly. Therefore, the relatively small number of knives, knife the corresponding smaller. Random elections knife on the tool must be coded to identify. There are three main coding.1. Tool coding. Adopt special knife handle structure coding, the drawbars on the knife handle back-end packages such as spacing of the coding part of the lock-nut fixed. Coding diameter ring diameter of a size two, respectively, said that binary "1" and "0" to the two rings are different, can be a series of code. For example, there are six small diameter of the ring can be made to distinguish between 63 (26-1 = 63) of the coding tool. All of 0 normally not allowed to use the code, to avoid the cutter knife Block did not confuse the situation.2. Knife Block coding. On the knife Block coding, coding tool, and tool into line with the number of knives in the Block. ATC knife when the rotation, so that each knife seats followed through knowledge knife, knife found blocks, knives stopped the rotation. At this time there is no knife handle encoding part of the knife handle simplified.3. Annex coding methods. This style of coding keys, coded cards, coding and coding-disc, which is the most widely used coding keys.First to knives are attached to a tool of the show wrapped coding keys, and when the cutter knife to the store at knife in, so put the number of keys to remember knife Block Road, will be inserted into key to the coding Block next to the key hole in the seat for the knife to the numbers.ConclusionFocused on in today's manufacturing environment tool storage and management of new models and methods, practical application of good results in systems integration and optimization, and other aspects of operations will be further explored, so that it has a higher theoretical and practical level.译文:机床刀具设计课题研究意义机床原来的刀库控制程序是单独设计的,没有采用刀具管理系统,功能也比较单一,只实现了刀库刀具的找刀、刀库最短路径定位、主轴换刀,而且不支持大型刀具。

机床数控化改造外文文献翻译、中英文翻译

机床数控化改造外文文献翻译、中英文翻译

外文资料First, CNC of the need for transformation1.1, microscopic view of the necessity ofFrom the micro perspective, CNC machine tools than traditional machines have the following prominent superiority, and these advantages are from the NC system includes computer power.1.1.1 can be processed by conventional machining is not the curve, surface and other complex partsBecause computers are superb computing power can be accurately calculated instantaneous each coordinate axis movement exercise should be instantaneous, it can compound into complex curves and surfaces.1.1.2 automated processing can be achieved, but also flexible automation to increase machine efficiency than traditional 3 to 7 times.Because computers are memory and storage capacity, can be imported and stored procedures remember down, and then click procedural requirements to implement the order automatically to achieve automation. CNC machine tool as a replacement procedures, we can achieve another work piece machining automation, so that single pieces and small batch production can be automated, it has been called "flexible automation."1.1.3 high precision machining parts, the size dispersion of small, easy to assemble, no longer needed "repair."1.1.4 processes can be realized more focused, in part to reduce the frequent removal machine.1.1.5 have automatic alarm, automatic control, automatic compensation, and other self-regulatory functions, thus achieving long unattended processing.1.1.6 derived from the benefits of more than five.Such as: reducing the labor intensity of the workers, save the labor force (onecan look after more than one machine), a decrease of tooling, shorten Trial Production of a new product cycle and the production cycle, the market demand for quick response, and so on.These advantages are our predecessors did not expect, is a very major breakthrough. In addition, CNC machine tools or the FMC (Flexible Manufacturing Cell), FMS (flexible manufacturing system) and CIMS (Computer Integrated Manufacturing System), and other enterprises, the basis of information transformation. NC manufacturing automation technology has become the core technology and basic technology.1.2, the macro view of the necessityFrom a macro perspective, the military industrial developed countries, the machinery industry, in the late 1970s, early 1980s, has begun a large-scale application of CNC machine tools. Its essence is the use of information technology on the traditional industries (including the military, the Machinery Industry) for technological transformation. In addition to the manufacturing process used in CNC machine tools, FMC, FMS, but also included in the product development in the implementation of CAD, CAE, CAM, virtual manufacturing and production management in the implementation of the MIS (Management Information System), CIMS, and so on. And the products that they produce an increase in information technology, including artificial intelligence and other content. As the use of information technology to foreign forces, the depth of Machinery Industry (referred to as information technology), and ultimately makes their products in the international military and civilian products on the market competitiveness of much stronger. And we in the information technology to transform traditional industries than about 20 years behind developed countries. Such as possession of machine tools in China, the proportion of CNC machine tools (CNC rate) in 1995 to only 1.9 percent, while Japan in 1994 reached 20.8 percent, every year a large number of imports of mechanical and electrical products. This also explains the macro CNC transformation of the need.Second, CNC machine tools and production lines of the transformation of the market2.1, CNC transformation of the marketMy current machine total more than 380 million units, of which only the total number of CNC machine tool 113,400 Taiwan, or that China's CNC rate of less than 3 percent. Over the past 10 years, China's annual output of about 0.6 CNC machine tools to 0.8 million units, an annual output value of about 1.8 billion yuan. CNC machine tools annual rate of 6 per cent. China's machine tool easements over age 10 account for more than 60% below the 10 machines, automatic / semi-automatic machine less than 20 per cent, FMC / FMS, such as a handful more automated production line (the United States and Japan automatic and semi-automatic machine, 60 percent above). This shows that we the majority of manufacturing industries and enterprises of the production, processing equipment is the great majority of traditional machine tools, and more than half of military age is over 10 years old machine. Processing equipment used by the prevalence of poor quality products, less variety, low-grade, high cost, supply a long period, in view of the international and domestic markets, lack of competitiveness, and a direct impact on a company's products, markets, efficiency and impact The survival and development of enterprises. Therefore, we must vigorously raise the rate of CNC machine tools.2.2, import equipment and production lines of the transformation of NC marketSince China's reform and opening up, many foreign enterprises from the introduction of technology, equipment and production lines for technological transformation. According to incomplete statistics, from 1979 to 1988 10, the introduction of technological transformation projects are 18,446, about 16.58 billion US dollars.These projects, the majority of projects in China's economic construction play a due role. Some, however, the introduction of projects due to various reasons, not equipment or normal operation of the production line, and even paralyzed, and the effectiveness of enterprises affected by serious enterprise is in trouble. Some of the equipment, production lines introduced from abroad, the digestion and absorption of some bad, spare parts incomplete, improper maintenance, poor operating results; onlypay attention to the introduction of some imported the equipment, apparatus, production lines, ignore software, technology, and management, resulting in items integrity, and potential equipment can not play, but some can not even start running, did not play due role, but some production lines to sell the products very well, but not because of equipment failure production standards; because some high energy consumption, low pass rate products incur losses, but some have introduced a longer time, and the need for technological upgrading. Some of the causes of the equipment did not create wealth, but consumption of wealth.These can not use the equipment, production lines is a burden, but also a number of significant assets in stock, wealth is repaired. As long as identifying the main technical difficulties, and solve key technical problems, we can minimize the investment and make the most of their assets in stock, gain the greatest economic and social benefits. This is a great transformation of the market.Third, NC transformation of the content and gifted missing3.1, the rise of foreign trade reformIn the United States, Japan and Germany and other developed countries, and their machine transform ation as new economic growth sector, the business scene, is in a golden age. The machine, as well as technology continues to progress, is a machine of the "eternal" issue. China's machine tool industry transformation, but also from old industries to enter the CNC technology mainly to the new industries. In the United States, Japan, Germany, with CNC machine tools and technological transformation of production lines vast market, has formed a CNC machine tools and production lines of the new industry. In the United States, transforming machine tool industry as renewable (Remanufacturing) industry. Renewable industry in the famous companies: Borsches engineering company, atoms machine tool company, Devlieg-Bullavd (Bo) services group, US equipment companies. Companies in the United States-run companies in China. In Japan, the machine tool industry transformation as machine modification (Retrofitting) industry. Conversion industry in the famous companies: Okuma engineering group, Kong 3 Machinery Company, Chiyoda Engineering Company, Nozaki engineering company, Hamada engineeringcompanies, Yamamoto Engineering Company.3.2, the content of NCMachine tools and production line NC transformation main contents of the following:One is the restoration of the original features of the machine tools, production line of the fault diagnosis and recovery; second NC, in the ordinary machine augends significant installations, or additions to NC system, transformed into NC machine tools, CNC machine tools; its Third, renovation, to improve accuracy, efficiency and the degree of automation, mechanical, electrical part of the renovation, re-assembly of mechanical parts processing, restore the original accuracy of their production requirements are not satisfied with the latest CNC system update; Fourth, the technology updates or technical innovation, to enhance performance or grades, or for the use of new technology, new technologies, based on the original technology for large-scale update or technological innovation, and more significantly raise the level, and grades of upgrading.3.3, NC transformation of the gifted missing3.3.1 reduce the amount of investment, shorter delivery timeCompared with the purchase of new machine, the general can save 60% to 80% of the costs and transforming low-cost. Especially for large, special machine tools particularly obvious. General transformation of large-scale machine, spent only the cost of the new machine purchase 1 / 3, short delivery time. But some special circumstances, such as high-speed spindle, automatic tray switching systems and the production of the installation costs too costly and often raise the cost of 2 to 3 times compared with the purchase of new machine, only about 50 percent of savings investment.3.3.2 stable and reliable mechanical properties, structure limitedBy the use of bed, column, and other basic items are heavy and solid casting components, rather than kind of welding components of the machine after the high-performance, quality, and can continue to use the new equipment for many years. But by the mechanical structure of the original restrictions, it is not appropriate to thetransformation of a breakthrough.3.3.3 become familiar with the equipment, ease of operation and maintenanceThe purchase of new equipment, new equipment do not know whether to meet the processing requirements. Transformation is not, can be used to calculate the machine processing capacity; In addition, since the use of many years, the operator of the machine has long been understood that in the operation, use and maintenance of the training time is short, quick. Transformation of the machine tools installed, we can achieve full load operation.3.3.4 can take full advantage of the existing conditionsTake full advantage of the existing foundation, not like buying new equipment as necessary to build a foundation.3.3.5 can be used as control technologyAccording to the development speed of technological innovation and in a timely manner increased level of automation in production equipment and efficiency, improve the quality of equipment and grades, and the old machine will be replaced by the current level of machine.Fourth, the main steps of CNC machine tools4.1, for the determination of transformationThrough analysis of the feasibility of transforming the future, we can against a Taiwan or a few machines determine the current status of reform programmes, which are generally include:4.1.1 mechanical and electrical repair of combiningGenerally speaking, the need for a transformation of the electrical machine, are subject to mechanical repairs. Repairs to determine the requirements, scope, content must be decided by electrical machinery required to transform the structure of the request; transformation to determine electrical and mechanical repair, alteration between the staggered time requirements. The mechanical properties of intact electrical transform the basis of success.4.1.2 easy first, and to the overall situation after the first localThe removal of the original system must control the original drawings, carefully, to make drawings in a timely manner marked to prevent the demolition or omission (of local circumstances). In the process of demolition will discover some new system design in the gaps, and that should be promptly added, removed and parts of the system should be disaggregated, safekeeping, in case of failure or partial failure reinstated. There is a definite value, and can be used for spare parts for other machines. Must not extravagantly used and misplaced.4.2 reasonable arrangements for a new location and routing systemUnder the new system design drawings and reasonable new system configurations, including fixed box, panel installation, alignments, and the fixed position adjustment components, sealing and necessary, such as decoration. Connection must be a clear division of work, it was reviewed inspection to ensure connectivity of norms, diameter appropriate, accurate, reliable handsome.4.3 DebuggingCommissioning must be identified in advance by the steps and requirements. Debugging should be cool-headed, keep records, in order to identify a nd solve problems. Commissioning of the first test sensitivity security protection systems to prevent physical, equipment accidents. Debugging the scene must be cleaned, no superfluous items; coordinates extension units in the campaign centre of the whole trip; empty can test, first empty after loading; can simulate the test, after the first real dynamic simulation; can manually the upper hand After moving automatically.4.4, acceptance and post-workAcceptance of the work to employ the staff to join, has been developed in accordance with the acceptance criteria. The transformation of the late work is also very important, it is conducive to enhancing the level of technical projects and equipment as soon as possible so that production. Acceptance and post include:4.4.1 machine mechanical properties acceptanceAfter mechanical repairs and maintenance as well as a full transformation, the mechanical properties of the machine tools should meet the requirement, in the geometric accuracy should be within the limits prescribed.4.4.2 electrical control function and control accuracy acceptanceElectrical control the various functions of action must be normal, sensitive and reliable. Application control accuracy of the system itself functions (such as stepping dimensions, etc.) and standard measurement apparatus (such as laser interferometer, coordinate measurement machines) inspection, the scope of accuracy achieved. At the same time also and the transformation of the former machine tool accuracy of the various functions and to contrast, poor access to quantifiable indicators.4.4.3 specimen cutting AcceptanceYou can refer to the CNC machine tool cutting at home and abroad specimen standards, qualified operatives, with the programming staff to test cutting. Acceptance specimen cutting machine stiffness can be cutting, noise, trajectory, and other related actions, the general should not be used for product components specimen use.4.4.4 drawings, information acceptanceMachine transformation of the latter should be timely drawings (including schematics, layout plans, wiring diagram, ladder diagram, etc.), information (including various brochures), the transformation of files (including the transformation before and after the various records) summary, collating, transfer to stall. Maintain data integrity, effective, continuous, and that the future stability of the equipment running is very important.4.4.5 summing up, enhancingAfter the end of each should be promptly summed up, helps improve the operational level of technical personnel, but also conducive to the whole enterprise technical progress.中文译文一、机床数控化改造的必要性1.1、微观看改造的必要性从微观上看,数控机床比传统机床有以下突出的优越性,而且这些优越性均来自数控系统所包含的计算机的威力。

数控技术 外文翻译 外文文献 英文文献 数控技术的发展与维修

数控技术 外文翻译 外文文献 英文文献 数控技术的发展与维修

Development and maintenance of CNC technology Numerical control technology and equipment is the development of new high-tech industry and cutting-edge enabling technology, industry and the most basic equipment. The world information industry, biological industry, aviation, aerospace and other defense industry widely used numerical techniques to improve manufacturing capacity and level, to improve the adaptability of the market and competitiveness. Industrial countries and CNC numerical control technology and equipment will also be listed as countries of strategic materials, not only to develop their own numerical control technology and industry, and in "sophisticated" technology and equipment, numerical control key aspects of the policy of closures and restrictions. Therefore, efforts to develop advanced numerical control technology as the core manufacturing technology has become the world's developed countries to accelerate economic development, enhance the comprehensive national strength and an important way to statehood.Part I: the development of CNC machine tools trends in individual1. High speed, high accuracy, high reliabilityHigh speed: To improve the speed and increase feed spindle speed.High precision: the precision from micron to sub-micron level, and even the nano-level (high reliability: the reliability of numerical control system generally higher than the reliability of numerical control equipment more than an order of magnitude, but not the higher the better reliability because the goods by the cost performance constraints.2. CompositeComposite function CNC machine tool development, its core is in a single machine to complete the turning, milling, drilling, tapping, reaming and reaming and other operating procedures, thereby increasing the efficiency and precision machine tools to improve production flexibility.3. IntelligentIntelligent content included in all aspects of the numerical control system: the pursuit of processing efficiency and processing quality of intelligence; to improve the performance and the use of convenient connections and other aspects of intelligence; simplify programming, simplifying operational intelligence; also like the intelligent automatic programming, intelligent man-machine interface, as well as intelligent diagnostics, intelligent monitoring and other aspects, to facilitate system diagnostics and maintenance.4. Flexible, integratedThe world of CNC machine tools to the development trend of flexible automation systems are: from the point (CNC single, composite machining centers and CNC machine tools), line (FMC, FMS, FTL, FML) to the surface (Section workshop independent manufacturing island FA) , body (CIMS, distributed network integrated manufacturing system) direction, the other to focus on applied and economic direction. Flexible automation technology is the industry to adapt to dynamic market demands and quickly update the primary means of product is the main trend of national manufacturing industry is the basis for the field of advanced manufacturing technology.Second, personalization is the adaptability of the market trendsToday's market, gradually formed the pattern of international cooperation, the products becoming more competitive, efficient and accurate processing of the escalating demand means, the user's individual requirements become increasingly strong, professional, specialization, more and more high-tech machine tools by the users of all ages.Third, the open architecture trend isThe core of a new generation of CNC system development is open. Open software platform and hardware platforms are open systems, modular, hierarchical structure, and through out the form to provide a unified application interface.CNC system to address the closure of the traditional CNC applications and industrial production problems. At present, many countries of open CNC system, CNC system has become an open numerical control system of the future of the road. The open numerical control system architecture specification, communication specifications, configuration specifications, operating platform, function libraries and CNC numerical control system software development tools, system function is the core of the current study. Network numerical control equipment is nearly two years of a new focus. NC network equipment will greatly satisfy the production lines, manufacturing systems, manufacturing information integration needs of enterprises, but also achieve new manufacturing model, such as agile manufacturing, virtual enterprises, global manufacturing the base unit. Some well-known at home and abroad, and CNC CNC machine tools manufacturing company inPart II: Machine MaintenanceCNC machine tools is electronic technology, measurement technology, automation technology, semiconductor technology, computer technology and electrical technology, and integrated set of automation equipment, high precision, high efficiency and high flexibility. CNC machine tools is a process control equipment and asked him in real-time control of the accuracy of every moment of work, any part of the fault and failure, so that the machine will shut down, resulting in production stoppages, which seriously affected and restricted the production efficiency . CNC machine tools in many industries to work the device is critical, if not after a failure in its maintenance and troubleshooting time, it will cause greater economic losses. Therefore, the principle that complex numerical control system, structure, maintenance of sophisticated equipment is necessary. CNC machine tools to enhance fault diagnosis and maintenance of power, can improve the reliability of CNC machine tools, CNC machine tools is conducive to the promotion and use.CNC machine tools is a mechanical, electrical, hydraulic, gas combination of complex equipment, though the reasons for failure vary, but the failure occurred, the general idea of the steps are the same. Fails,Spindle start below to stop immediately after the fault diagnosis of CNC machine tools as an example the general process.First, the fault-site investigation. The survey content includes 1, 2 types of failure, the failure frequency of 3, 4, external conditions, the operating conditions 5, 6, machine conditions, the functioning of 7, wiring between machine tools and systems 8, CNC equipment visual inspection. After an investigation, such failure is spindle class failure, only once, outside of all normal, the operator of a boot to reflect this situation.Second, the fault information collation, analysis. For some simple fault, because not alot of time, the method can be used form of logical reasoning, analysis, identification and troubleshooting. After a failed on-site investigation for several reasons we suspect that the system output pulse ①②drive is not enough time to move the state line to control the spindle components ③④damage to the spindle motor short-circuit, causing the spindle thermal relay protection ⑤ not with self-control loop lock circuits, and the parameter is set to pulse signal output, so that the spindle can not operate normally. Identify possible reasons to rule out one by one.Third, conduct fault diagnosis and troubleshooting.Diagnosis usually follows the following principles: 1, after the first outside inside. Reliable line of modern CNC system increasingly high failure rate of CNC system itself less and less, and most are non-occurrence of failure causes the system itself. The CNC machine is a mechanical, hydraulic, electrical as one of the tools, the occurrence of the fault will be reflected by these three comprehensive, maintenance personnel should be from outside to inside one by one investigation to avoid arbitrary unsealed, demolition, otherwise expand the malfunction, so that the loss of precision machine tools, slow performance, outside the system detected the fault is due to open one by one, hydraulic components, pneumatic components, electrical actuators, mechanical devices caused problems. 2, the first after the electrical machinery. In general, the mechanical failure easier to find, and numerical control system and electrical fault diagnosis more difficult, before the troubleshooting to rule out mechanical failure of the first 3, after the first static dynamic. Power off the machine first, quiescent state, through understanding, observation, testing, analysis, confirm the power failure will not result in expansion of the incident only after the power to the machine, run the state, the dynamic of observation, inspection and testing, to find fault. While after the devastating power failure, you must first rule out the danger, before electricity. 4, after the first simple and complex. When multiple failures are intertwined, and sometimes impossible to start with, we should first solve the problem easily, then solve the difficult problem, often a simple problem to solve, the difficulty of the problem may also become easier.CNC machine tools in the fault detection process, should make full use of numerical control system self-diagnostic features to be judged, but also flexibility in the use of some common troubleshooting methods. Troubleshooting common methods are:1. Routine examination methodRoutine examination method is mainly of hands, eyes, ears, nose and other organs of the fault occurrence of various light, sound, smell and abnormal observations and careful look at every system, follow the "first post outside of" the principle of fault diagnosis by looking, listening, smelling, asking, mold and so on, from outside to inside one by one check, the fault can often be narrowed down to a module or a printed circuit board. This requires maintenance personnel have a wealth of practical experience, to the wider multidisciplinary and comprehensive knowledge of the ability to judge.2. Self-diagnostic function methodModern CNC system has yet to achieve a high degree of intelligence. But already has a strong self-diagnostic function. CNC ready to monitor the hardware and software is working. Once the abnormal, immediately displayed on the CRT alarm or fault LEDs indicate the approximate cause. Using self-diagnosis function, but also shows the interface signals between the system and the host state, in order to determine the fault occurred in themechanical part or parts of NC system, and indicate the approximate fault location. This method is currently the most effective maintenance methods.3. Functional program testing methodSo-called functional program testing method is commonly used in the numerical control system functions and special features, such as linear positioning, circular interpolation, helical cut, fixed cycle, such as the user macro programming by hand or automatic programming methods, the preparation of test procedures into a functional program , into the numerical control system, and then start the CNC system to make it run, to check the im time the first boot of CNC whether a programming error or operational error or machine4. Spare parts substitutionSpare parts replacement method is a simple method to determine the scene is one of the most commonly used. The so-called spare substitution is generally the cause of failure in the analysis of the case, maintenance personnel can use the alternate PCB, templates, integrated circuit chip or replace the questionable parts of components, which narrowed the fault to a printed circuit board or chip level. It is actually in the verification analysis is correct. However, before switching the standby board should carefully check the spare board is intact, and should check the status of reserve board should be fully consistent with the original board the state. This includes checking with the board selection switch, set the location and the short rod potentiometer position. In short, we must strictly in accordance with the system's operation, maintenance requirements manual operation.In determining the replacement of a part to, should carefully check the relevant connected to electrical lines and other related, confirming that no failure up to the new replacement to prevent failures caused by external damage to replace the parts up.5. Transfer ActThe so-called transfer method is to have the same numerical control system features two printed circuit boards, templates, integrated circuit chips or components to exchange, observed failure phenomena be transferred. In this way, the system can quickly determine the fault position. This method is actually a kind of spare parts substitution. Therefore, the considerations described in the same spare parts substitution.6. Parameter check methodKnown parameters can directly affect the numerical performance of CNC machine tools. Parameters are usually stored in the magnetic bubble memory, or stored in batteries to be maintained by the CMOS RAM, once the battery is low or because of outside interference and other factors, some parameters will be lost or change in chaos, so that the machine does not work. At this point, through the proofreading, correction parameters, will be able to troubleshoot. When the machine idle for a long time to work again for no reason that there is no normal or failure without warning, it should be based on fault characteristics, inspection and proof-reading the relevant parameters.After a long run of CNC machine tools, wear and tear due to its mechanical drive components, electrical component performance changes and other reasons, also need to adjust the parameters of its. Some machine tool failure is often not timely because the parameters change due to some not meet. Of course, these failures are the fault of the areas are soft.7. Measurement of Comparative LawCNC system in the design of printed circuit board manufacturing plant, in order to adjust, repair facilities, in the printed circuit board designed a number of test terminals. Users can also use normal printed circuit board terminals comparing the measured and the difference between the printed circuit board failure. These terminals can detect the voltage and waveform measurements, analyze the causes of failure and failure location. Even on a normal printed circuit board can sometimes artificially create "fault", such as broken connection or short circuit, unplug the components, in order to determine the real cause of failure. Therefore, maintenance personnel should be in the usual accumulation of key parts of the printed circuit board or failure-prone parts of the right in the normal waveform and voltage values. Because the CNC system manufacturer often does not provide the information in this regard.8. Percussion methodWhen the CNC system failures showed Ruoyouruowu, often used method for detecting the fault struck the site lies. This is because the numerical control system is composed by the multi-block printed circuit boards, each board has a lot of solder joints, plates or between modules and is connected through the connectors and cables. Therefore, any cold solder joint or bad, may cause a malfunction. When the tap with the insulation and poor contact with Weld doubt at fault must be repeated reproduction.9. Local heating methodAfter a long running CNC system components are to be aging, performance will deteriorate. When they are not fully damaged, failures will become from time to time. Then heat can be used such as a hair dryer or electric iron is suspected to local heating components, accelerating the aging so thoroughly exposed fault components. Of course, using this method, be sure to pay attention to components of the temperature parameters, do not roast the original device is a good or bad.10. Principle of analysisThe composition according to principles of numerical control system can be analyzed from various points of logical levels and logical parameters (such as voltage or waveform) and then with a multimeter, logic pen, only the oscilloscope or logic analyzer to measure, analyze and compare, and thus failure positioning. Using this method, which requires maintenance personnel to be on the whole system or the principle of each circuit have a clear, deep understanding.Based on the above principles and methods, we may be itemized on the check it and eliminate the causes.The first possible failure for the system output pulse time is not enough, we adjust the M-code system, start the spindle output time, found the problem still exists, and then find the next possible cause may be in the drive to move the state, refer to the manual drive , set parameters start the spindle, the problem still exists we suspected spindle motor short-circuit, resulting in thermal relay protection. Then find the cause of the short, so that the spindle thermal relay reset the start and found that the normal operation of the spindle, the problem solved.Fourth, do a lessons learned and recorded. After troubleshooting, repair work can not be considered complete, still need technical and management aspects of the underlying causes of failure have to take appropriate measures to prevent failures from happening again. Underfield conditions when necessary use of mature technologies to transform and improve the equipment. Finally, the failure of the maintenance of the phenomenon, cause analysis, resolution process, the replacement of components, legacy, etc. to make a record.数控技术的发展与维修数控技术及装备是发展新兴高新技术产业和尖端工业的使能技术和最基本的装备。

机械类数控车床外文翻译外文文献英文文献车床.doc

机械类数控车床外文翻译外文文献英文文献车床.doc

LathesLathes are machine tools designed primarily to do turning, facing and boring, Very little turning is done on other types of machine tools, and none can do it with equal facility. Because lathes also can do drilling and reaming, their versatility permits several operations to be done with a single setup of the work piece. Consequently, more lathes of various types are used in manufacturing than any other machine tool.The essential components of a lathe are the bed, headstock assembly, tailstock assembly, and the leads crew and feed rod.The bed is the backbone of a lathe. It usually is made of well normalized or aged gray or nodular cast iron and provides s heavy, rigid frame on which all the other basic components are mounted. Two sets of parallel, longitudinal ways, inner and outer, are contained on the bed, usually on the upper side. Some makers use an inverted V-shape for all four ways, whereas others utilize one inverted V and one flat way in one or both sets, They are precision-machined to assure accuracy of alignment. On most modern lathes the way are surface-hardened to resist wear and abrasion, but precaution should be taken in operating a lathe to assure that the ways are not damaged. Any inaccuracy in them usually means that the accuracy of the entire lathe is destroyed.The headstock is mounted in a foxed position on the inner ways, usually at the left end of the bed. It provides a powered means of rotating the word at various speeds . Essentially, it consists of a hollow spindle, mounted in accurate bearings, and a set of transmission gears-similar to a truck transmission—through which the spindle can be rotated at a number of speeds. Most lathes provide from 8 to 18 speeds, usually in a geometric ratio, and on modern lathes all the speeds can be obtained merely by moving from two to four levers. An increasing trend is to provide a continuously variable speed range through electrical or mechanical drives.Because the accuracy of a lathe is greatly dependent on the spindle, it is of heavy construction and mounted in heavy bearings, usually preloaded tapered roller or ball types. The spindle has a hole extending through its length, through which long bar stock can be fed. The size of maximum size of bar stock that can be machined when the material must be fed through spindle.The tailsticd assembly consists, essentially, of three parts. A lower casting fits on the inner ways of the bed and can slide longitudinally thereon, with a means for clamping the entire assembly in any desired location, An upper casting fits on the lower one and can be moved transversely upon it, on some type of keyed ways, to permit aligning the assembly is the tailstock quill. This is a hollow steel cylinder, usually about 51 to 76mm(2to 3 inches) in diameter, that can be moved several inches longitudinally in and out of the upper casting by means of a hand wheel and screw.The size of a lathe is designated by two dimensions. The first is known as the swing. This is the maximum diameter of work that can be rotated on a lathe. It is approximately twice the distance between the line connecting the lathe centers and the nearest point on the ways, The second size dimension is the maximum distance between centers. The swing thus indicates the maximum work piece diameter that can be turned in the lathe, while the distance between centers indicates the maximum length of work piece that can be mounted between centers.Engine lathes are the type most frequently used in manufacturing. They are heavy-duty machine tools with all the components described previously and have power drive for all tool movements except on the compound rest. They commonly range in size from 305 to 610 mm(12 to 24 inches)swing and from 610 to 1219 mm(24 to 48 inches) center distances, but swings up to 1270 mm(50 inches) and center distances upto 3658mm(12 feet) are not uncommon. Most have chip pans and a built-in coolant circulating system. Smaller engine lathes-with swings usually not over 330 mm (13 inches ) –also are available in bench type, designed for the bed to be mounted on a bench on a bench or cabinet.Although engine lathes are versatile and very useful, because of the time required for changing and setting tools and for making measurements on the work piece, thy are not suitable for quantity production. Often the actual chip-production tine is less than 30% of the total cycle time. In addition, a skilled machinist is required for all the operations, and such persons are costly and often in short supply. However, much of the operator’s time is consumed by simple, repetitious adjustments and in watching chips being made. Consequently, to reduce or eliminate the amount of skilled labor that is required, turret lathes, screw machines, and other types of semiautomatic and automatic lathes have been highly developed and are widely used in manufacturing.2 Numerical ControlOne of the most fundamental concepts in the area of advanced manufacturing technologies is numerical control (NC). Prior to the advent of NC, all machine tools ere manually operated and controlled. Among the many limitations associated with manual control machine tools, perhaps none is more prominent than the limitation of operator skills. With manual control, the quality of the product is directly related to and limited to the skills of the operator. Numerical control represents the first major step away from human control of machine tools.Numerical control means the control of machine tools and other manufacturing systems through the use of prerecorded, written symbolic instructions. Rather than operating a machine tool, an NC technician writes a program that issues operational instructions to the machine tool. For a machine tool to be numerically controlled, it must be interfaced with a device for accepting and decoding the programmed instructions, known as a reader.Numerical control was developed to overcome the limitation of human operators, and it has done so. Numerical control machines are more accurate than manually operated machines, they can produce parts more uniformly, they are faster, and the long-run tooling costs are lower. The development of NC led to the development of several other innovations in manufacturing technology:Electrical discharge machining,Laser cutting,Electron beam welding.Numerical control has also made machine tools more versatile than their manually operated predecessors. An NC machine tool can automatically produce a wide of parts, each involving an assortment of widely varied and complex machining processes. Numerical control has allowed manufacturers to undertake the production of products that would not have been feasible from an economic perspective using manually controlled machine tolls and processes.Like so many advanced technologies, NC was born in the laboratories of the Massachusetts Institute of Technology. The concept of NC was developed in the early 1950s with funding provided by the U.S. Air Force. In its earliest stages, NC machines were able to made straight cuts efficiently and effectively.However, curved paths were a problem because the machine tool had to be programmed to undertake a series of horizontal and vertical steps to produce a curve. The shorter the straight lines making up the steps, the smoother is the curve, Each line segment in the steps had to be calculated.This problem led to the development in 1959 of the Automatically Programmed Tools (APT) language. This is a special programming language for NC that uses statements similar to English language to define the part geometry, describe the cutting tool configuration, and specify the necessary motions. The development of the APT language was a major step forward in the fur ther development from those used today. The machines had hardwired logic circuits. The instructional programs were written on punchedpaper, which was later to be replaced by magnetic plastic tape. A tape reader was used to interpret the instructions written on the tape for the machine. Together, all of this represented a giant step forward in the control of machine tools. However, there were a number of problems with NC at this point in its development.A major problem was the fragility of the punched paper tape medium. It was common for the paper tape containing the programmed instructions to break or tear during a machining process. This problem was exacerbated by the fact that each successive time a part was produced on a machine tool, the paper tape carrying the programmed instructions had to be rerun through the reader. If it was necessary to produce 100 copies of a given part, it was also necessary to run the paper tape through the reader 100 separate tines. Fragile paper tapes simply could not withstand the rigors of a shop floor environment and this kind of repeated use.This led to the development of a special magnetic plastic tape. Whereas the paper carried the programmed instructions as a series of holes punched in the tape, the plastic tape carried the instructions as a series of magnetic dots. The plastic tape was much stronger than the paper tape, which solved the problem of frequent tearing and breakage. However, it still left two other problems.The most important of these was that it was difficult or impossible to change the instructions entered on the tape. To made even the most minor adjustments in a program of instructions, it was necessary to interrupt machining operations and make a new tape. It was also still necessary to run the tape through the reader as many times as there were parts to be produced. Fortunately, computer technology became a reality and soon solved the problems of NC associated with punched paper and plastic tape.The development of a concept known as direct numerical control (DNC) solved the paper and plastic tape problems associated with numerical control by simply eliminating tape as the medium for carrying the programmed instructions. In direct numerical control, machine tools are tied, via a data transmission link, to a host computer. Programs for operating the machine tools are stored in the host computer and fed to the machine tool an needed via the data transmission linkage. Direct numerical control represented a major step forward over punched tape and plastic tape. However, it is subject to the same limitations as all technologies that depend on a host computer. When the host computer goes down, the machine tools also experience downtime. This problem led to the development of computer numerical control.3 TurningThe engine lathe, one of the oldest metal removal machines, has a number of useful and highly desirable attributes. Today these lathes are used primarily in small shops where smaller quantities rather than large production runs are encountered.The engine lathe has been replaced in today’s production shops by a wide variety of automatic lathes such as automatic of single-point tooling for maximum metal removal, and the use of form tools for finish on a par with the fastest processing equipment on the scene today.Tolerances for the engine lathe depend primarily on the skill of the operator. The design engineer must be careful in using tolerances of an experimental part that has been produced on the engine lathe by a skilled operator. In redesigning an experimental part for production, economical tolerances should be used.Turret Lathes Production machining equipment must be evaluated now, more than ever before, this criterion for establishing the production qualification of a specific method, the turret lathe merits a high rating.In designing for low quantities such as 100 or 200 parts, it is most economical to use the turret lathe. In achieving the optimum tolerances possible on the turrets lathe, the designer should strive for a minimum of operations.Automatic Screw Machines Generally, automatic screw machines fall into several categories; single-spindle automatics, multiple-spindle automatics and automatic chucking machines. Originally designed for rapid, automatic production of screws and similar threaded parts, the automatic screw machine has long since exceeded the confines of this narrow field, and today plays a vital role in the mass production of a variety of precision parts. Quantities play an important part in the economy of the parts machined on the automatic screw machine. Quantities less than on the automatic screw machine. The cost of the parts machined can be reduced if the minimum economical lot size is calculated and the proper machine is selected for these quantities.Automatic Tracer Lathes Since surface roughness depends greatly on material turned, tooling , and feeds and speeds employed, minimum tolerances that can be held on automatic tracer lathes are not necessarily the most economical tolerances.In some cases, tolerances of 0.05mm are held in continuous production using but one cut . groove width can be held to 0.125mm on some parts. Bores and single-point finishes can be held to 0.0125mm. On high-production runs where maximum output is desirable, a minimum tolerance of 0.125mm is economical on both diameter and length of turn.车床车床主要是为了进行车外圆、车端面和镗孔等项工作而设计的机床。

数控机床机电一体化外文文献翻译

数控机床机电一体化外文文献翻译

数控机床机电一体化外文文献翻译(含:英文原文及中文译文)文献出处:Safavi S M, Mirian S S, Abedinzadeh R, et al. Use of PLC module to control a rotary table to cut spiral bevel gear with three-axis CNC milling[J]. International Journal of Advanced Manufacturing Technology, 2010, 49(9-12):1069-1077.英文原文Use of PLC module to control a rotary table to cut spiral bevel gear withthree-axis CNC millingSafavi S M, Mirian S S, Abedinzadeh RAbstractCNC machining nowadays makes more use of "Mechatronics" increasingly. Combining numerical control with mechanic, electric, and data processing systems can lead to new methods of production. In recent years, the development of CNC has made it possible to perform nonlinear correction motions for the cutting of spiral bevel gears. In this paper, we attempt to manufacture the spiral bevel gear using a three-axis CNC milling machine interfaced with an additional PLC module based on traditional discontinuous multi-cutting method accomplished by using a universal milling machine interfaced with an indexing work head. This research consists of (a) geometric modeling of the spiral bevel gear, (b) simulating the traditional and our new nontraditional method using aCAD/CAE system, (c) process planning for CNC machining and PLC Programming, (d) experimental cuts with a three-axis CNC milling machine were made to discover the validity of the presented method. The results demonstrate that invented experimental cutting method of SBGs not only is less expensive than advanced CNC machining but also produces gears in a shorter time in comparison with the traditional cutting. Thereby, it is an economical method in manufacturing of SBGs. Keywords: ear manufacturing . Spiral bevel gear .CAD/CAM/CAE . CNC . PLC . AC motor . Inverter .Proximity sensors . Photoelectric sensors . Rotary encoder1 IntroductionGears are important precision mechanisms in the field of industrial machinery, used to transmit mechanical power and mechanical movement between parallel shafts, transverse crosses or non-intersecting shafts. Although sometimes invisible, gear is still one of the most important mechanical components in our industrial civilization. Under a wide variety of conditions, gears will operate at almost unlimited speed. The gear processing equipment and process that have been developed have been very advanced and mature. Whether for mass production or small batch production, the process of machining gears requires the following four steps, whether in a small workshop or a batch processing workshop:(1) Cutting(2) cutting teeth(3) Heat treatment(4) GrindingAccording to their type, application range and strength and stiffness requirements, gears are usually manufactured through casting, extrusion, forging, powder metallurgy, injection molding and hobbing. In this series of machining processes, the spiral bevel gear is the most complicated kind of gear, and it is used to transmit rotary motion between the angled horizontal axes. In the direction of the tooth length, the spiral bevel gear has a radially curved tooth profile curve. This kind of gear can ensure a smooth engagement with the mating gears, mainly because they have a curved profile that outperforms the spur gears, so that they will contact and engage more teeth at the same time. The design and manufacture of spiral bevel gears is still a hot topic of research. It has been used in helicopter transport gear trains, motorcycle gear reducers and other industrial branches. For manufacturing, such gears are usually machined from a special machine, such as gear hobbing machines and forming machines. At present, special CNC machine tools based on gear tooth processing have been used in industrial practice. This may be the reason why the related literature on gear processing is scarce in the public research field. Recently, CNC machine tools based on gear machining have been developed and gradually used in industrial practice. However,their motion structure is still intrinsically different from industrial CNC milling machines. The former is designed for a special tool. Previous research on gears mainly related to the design and analysis of gears. While studying its geometric features and design parameters, Tsai and Chin provide a mathematical surface model for bevel gears (spur gears, helical bevel gears) based on gear transmission in the tangential direction and involute gear geometry. Later, this scheme was compared with A-daccak et al. and Shunmugan et al. based on a precision spherical involute gear surface model to arrive at a completely different model. Based on the nominal deviation, the accuracy (compared with the use of a special machine tooling spiral bevel gear) has been verified.For crown gears, some conclusions are feasible. Litvin and Kim proposed the use of Fan Cheng method to obtain involute curves by improving the base circle of spur gears. Using the modified measured value of the helical gear transmission error, Umeyama designed a standard profile on the pitch circle and designed an improved profile on the upper and lower surfaces of the face gear. Tamura et al. developed a point contact model for a bevel gear with a flat tooth profile. These studies are related to the return tooth profile of those special gear processing machines (eg gear hobbing machines, forming machines) specially designed for machining gears. Suh et al. studied the feasibility of the processing method for the engraving surface of spiral bevel gears,and verified the possibility of using a four-axis CNC milling machine with a gyration-swing lifting platform to generate machining trajectories. At the same time, a model-based verification method for helical bevel gears has also been proposed.In this paper, we will try a new machining process for spiral bevel gears, using a three-axis milling machine with a PLC module that can be used to control the index table. Obviously, the productivity of this processing method is not as good as that of special-purpose machine tools. In addition to productivity, the advantages of this processing method are as follows: (1) Traditional processing methods require large investment costs to obtain various special machine tools, and the types of gears, sizes, and geometries that are selected for tool processing are also very limited; (2) With this new processing method, various types of gears can be machined through industrial three-axis CNC milling machines; (3) Compared with the use of special-purpose machine tools, this method is more economical. A different focus from previous work is that in order to simulate the entire process and obtain the processing parameters, an automated computer model needs to be developed. All previous studies are calculating complex mathematical equations and designing geometric models. In view of the above, our focus is on the experimental testing of spiral bevel gears rather than the geometric or mathematical model of helical bevel gears. This is the first time to use a mechatronic machineand a CNC milling machine to process special gears and even a mechanical component.2 Helical bevel gear geometryIn general, the geometry of a gear is given by engineering drawings. For defining its geometry, some parameters (main parameters) are necessary. For this purpose, we use the drive element development software named "GearTrax" to calculate these main parameters.The design of spiral bevel gears requires high-precision mathematical calculations, and the production of such gear transmissions requires not only high-quality equipment and machine tools that process such gear trains, but also the need to extend appropriate machine parameter settings. Although this setting is not up to standard, it also needs to be able to guarantee theThe design of each condition of the motion requirement (according to the geometric parameters of the gear transmission and the development tool) is determined.3 Processing spiral bevel gearFrom the discussion in the introduction, we know that all types of gears can be processed to achieve all the required specifications, and the processing methods for high-precision gears are still excellent. Forming Milling is the most common machining procedure for machining any type of gear. The props used all have the same shape as the adjacent gearteeth gap. Standard tools are commonly used for forming and cutting gears. In the United States, each of these cutters is 8 times the original diameter and is used to machine the multi-tooth gears indicated on the standard table. Gleason Corporation is based on the general concept of bevel gears developed to complement the principle of crown gears: large and small meshed gears can be considered separately and surface hobbing is used.Fan Cheng's crown gear can be considered as a special helical gear with a helix angle of 90 degrees. Therefore, the generic term “gear gear” emerged. When the mating face of the generated large and small gears is conjugated, consideration can be given to supplementing the concept of vanishing crown gears. In practice, the teeth of the gears may differ from one another in order to match the mismatched tooth surfaces. The rotation of the gear is reflected by the cradle rotation on the gear.To process spiral bevel gears with a three-axis CNC milling machine, we should first enjoy program testing of the CAD/CAM system's geometry modeling and simulation module. Use commercial software Solidworks to create CAD models and MSCs. Visual NASTRAN 4D software (a CAE mechanical motion analysis system using a 3D model) was used to simulate gear machining and analyze the results.For the structure of the machine tool, it is obvious that the history of the rotary motion of the workpiece on the spiral bevel gear CNC machinetool is necessary. Based on the analysis of its cutting performance, through a one-step installation, the spiral bevel gear CNC machining can at least achieve the requirements of four-axis control. Therefore, it is necessary to provide a rotary table for a three-axis milling machine. Forming or forming milling are used in the test. The tool is fed radially from the desired tooth height of the center of the gear blank and passes through the tooth face, while the rotary table rotates the work piece about its center to obtain the desired tooth width. When a tooth is machined, the tool is retracted and the indexing head indicates the gear blank, continuing to cut the next tooth. Basically, this method is a simple and flexible spiral bevel gear processing method. The required equipment and tools are relatively simple and only standard three-axis CNC milling machines are used. However, to prevent any damage to the workpiece, we need to be cautious about the short-range tool feed for each step.We created helical bevel gears in the GearTrax environment to simulate operating procedures and estimate some machining parameters such as the end mill's original height, proximity sensor position, motor torque, motor speed, and rotational frequency. For example, in the Solidworks environment, the pitch distance between the end mill and the helical bevel gear is 14.7mm, which is what we use to vertically position the main axis along the Z axis.At the same time, based on the graphical reports provided by ourCAE system, the motor's angular speed and torque are 1rpm and 48Nm, respectively.Mastercam is a kind of mechanical professional software that can generate tool trajectories. According to the total depth of the gear and the width of the surface, a tool path with a rectangular machining contour can be designed in our cutting program. Other machining parameters and tool specifications should also be entered in the tool path menu of the software. In the Processing Outline window, we need to use the following two options:1. Taking into account the larger control of the cutting amount, the multi-port allows the tool to be step-by-step.2. Import/Export elongated or shortened tool trajectory before entry/exit position change without additional geometry, which helps us to control machining compensation and enable short time programming of fixed machining contours. Becomes possible.Although the forming and cutting of such gears are generally performed using a dividing head on a universal milling machine, the machining process is slow and requires skilled workers and operators. The tool is mounted on the shank shaft, using a dividing head to rotate (cut teeth) and indicate the gear blank. The table is set at a helix angle of 35 degrees, and the indexing head should also be adapted to the longitudinal screw of the table so that the gear blank can be rotatedlongitudinally. For the method provided above, we used an AC motor connected to a worm gearbox. The worm gearbox is used to reduce the output speed of the AC motor and set the angle between the conical surfaces of the tooth segments to the helix angle.As long as the synchronism between the tool trajectory programming and the rotary motion of the output shaft of the worm gearbox meets the requirements, the mechatronic system can control four axes at the same time (one axis is used for rotary motion of the table, and three axes are used for tool cutting. movement).At the same time, we use ladder diagrams and general programming languages to operate PLCs in mechatronic systems. Based on the ladder diagram, the PLC operation steps are as follows:The first step is to read the external input signal, such as the address of the sensor and rotary encoder.The second step, based on the input signal value in the first step, calculates the output signal and sends it to the inverter (inverter) to drive the AC motor forward or reverse the rotation of the motor by a certain angle (pitch) ). While configuring the CNC milling machine, all system procedures are completed in the following five stages:In the first stage, the forming knife reaches the first proximity sensor. Once the sensor detects the forming knife, it sends a +5V signal to the PLC. As mentioned before, the PLC receives the signal and sends anoutput signal to the inverter to drive the motor. turn.In the second stage, the rotating workpiece is machined with a forming tool in the tool path created in Mastercam. In the third stage, the tool reaches the second proximity sensor. The sensor transmits the second signal to the PLC by detecting the tool, and the PLC receives and sends a stop command to the inverter.Stage 4 The cutter retracts from the stopped workpiece and returns to the starting position. At the same time, the inverter drives the motor in reverse until the output shaft returns to the first station. In this position, the receiver of the photosensor can receive transmission light through the longitudinal crack of the output shaft.Stage 5 Repeat one to four stages until the first interdental cutting is completed. The PLC counts the number of times the above four phases are run until the preset number of times in the machining program is reached. Then, the PLC sends a signal to the inverter to indicate that the gear blank has reached the machining diameter size, and then repeats all the above stages. The machining diameter is determined by a rotary encoder with 1024 pulses/revolution.In the advantageous embodiment of this innovative processing method, processing time is one of the main concerns. For example, it takes only 2 minutes to finish machining one tooth. In comparison, it takes more than half an hour to process the same tooth using traditionalmethods.In this innovative and far-reaching demonstration of manual cutting, the instantaneous angular compensation of the cutting head is set immediately before the end of the jump sequence.4 Processing StrategyThe workpiece is made of wood, and the blank is pre-processed into a cone shape (top cone angle) by turning. The No. 5 standard knife used for the experiment was mounted on the spindle of the machine tool, and the gear blank was mounted on the output shaft of the worm gearbox. Subsequently, the tool feeds the center of the gear blank to achieve the required tooth depth (around 30 machining programs to avoid the occurrence of defective products). After machining, one tooth is removed and the knife is retracted; according to the compiled program, the gear blank is guided by the AC motor and then the next tooth is cut.5 ConclusionIn this paper, we try to use a three-axis CNC milling machine to process helical bevel gears by forming milling. In order to achieve this goal, we studied the cutting step and tool path algorithm for CAD/CAM molds. Using complex mathematical procedures, all pre-work is closely related to design, and does not rely on empirical processing theory. Fundamentally speaking, forming cutting is simple and flexible for machining gears. The equipment and tools required are relatively simpleand inexpensive, and a standard CNC milling machine is sufficient. Thus, no skilled operator is required to create a processing system. Compared with the conventional method of processing gears using a professional machine tool, the machining method used in this paper is used to process various specifications of helical bevel gears or other types of gears, and it is also easy to improve. Compared with manual cutting, this method is fully automatic, because all processing parameters are obtained through the computer module. This processing concept is also a versatile system (using mechatronics and CNC systems) and will continue to grow.中文译文PLC 模块控制回转工作台在三轴数控铣床铣削螺旋伞齿轮中的应用摘要当今, 数控机床在机电一体化领域中得到了日益广泛的应用。

数控机床外文文献翻译、中英文翻译

数控机床外文文献翻译、中英文翻译

1 原文一CNC machine tools Outdate, J. and Joe, J. Configuration Synthesis of Machining Centers with Tool ,John Wiley & sons, 2001 While the specific intention and application for CNC machines vary from one machine type to another, all forms of CNC have common benefits. Here are but a few of the more important benefits offered by CNC equipment. The The first first first benefit benefit benefit offered offered offered by by by all all all forms forms forms of of of CNC CNC CNC machine machine machine tools tools tools is is is improved improved automation. automation. The The The operator operator operator intervention intervention intervention related related related to to to producing producing producing work work work pieces pieces pieces can can can be be reduced reduced or or or eliminated. eliminated. eliminated. Many Many Many CNC CNC CNC machines machines machines can can can run run run unattended unattended unattended during during during their their their entire entire machining machining cycle, cycle, cycle, freeing freeing freeing the the the operator operator operator to to to do do do other other other tasks. tasks. tasks. This This This gives gives gives the the the CNC CNC CNC user user several several side side side benefits benefits benefits including including including reduced reduced reduced operator operator operator fatigue, fatigue, fatigue, fewer fewer fewer mistakes mistakes mistakes caused caused caused by by human human error, error, error, and and and consistent consistent consistent and and and predictable predictable predictable machining machining machining time time time for for for each each each work work work piece. piece. Since the machine will be running under program control, the skill level required of the CNC operator (related to basic machining practice) is also reduced as compared to a machinist producing work pieces with conventional machine tools. The second major benefit of CNC technology is consistent a nd accurate work and accurate work pieces. Today's CNC machines boast almost unbelievable accuracy and repeatability specifications. This means that once a program is verified, two, ten, or one thousand identical work pieces can be easily produced with precision and consistency. A third benefit offered by most forms of CNC machine tools is flexibility. Since these these machines machines machines are are are run run run from from from programs, programs, programs, running running running a a a different different different workpiece workpiece workpiece is is is almost almost almost as as easy as loading a different program. Once a program has been verified and executed for one production run, it can be easily recalled the next time the workpiece is to be run. This leads to yet another benefit, fast change over. Since these machines are very easy to set up and run, and since programs can be easily loaded, they allow very short setup time. This is imperative with today's just-in-time (JIT) product requirements. Motion control - the heart of CNC The The most most most basic basic basic function function function of of of any any any CNC CNC CNC machine machine machine is is is automatic, automatic, automatic, precise, precise, precise, and and consistent consistent motion motion motion control. control. control. Rather Rather Rather than than than applying applying applying completely completely completely mechanical mechanical mechanical devices devices devices to to cause cause motion motion motion as as as is is is required required required on on on most most most conventional conventional conventional machine machine machine tools, tools, tools, CNC CNC CNC machines machines allow motion control in a revolutionary manner2. All forms of CNC equipment have two two or or or more more more directions directions directions of of of motion, motion, motion, called called called axes. axes. axes. These These These axes axes axes can can can be be be precisely precisely precisely and and automatically automatically positioned positioned positioned along along along their their their lengths lengths lengths of of of travel. travel. travel. The The The two two two most most most common common common axis axis types are linear (driven along a straight path) and rotary (driven along a circular path). Instead of causing motion by turning cranks and handwheels as is required on conventional machine tools, CNC machines allow motions to be commanded through programmed programmed commands. commands. commands. Generally Generally Generally speaking, speaking, speaking, the the the motion motion motion type type type (rapid, (rapid, (rapid, linear, linear, linear, and and circular), the axes to move, the amount of motion and the motion rate (federate) are programmable with almost all CNC machine tools. A CNC command executed within the control tells the drive motor to rotate a precise number of times. The rotation of the drive motor in turn rotates the ball screw. And the ball screw drives the linear axis (slide). A feedback device (linear scale) on the slide allows the control to confirm that the commanded number of rotations has taken place3. Refer to fig.1. fig.1 typical drive system of a CNC machine tool Though a rather crude analogy, the same basic linear motion can be found on a common table vise. As you rotate the vise crank, you rotate a lead screw that, in turn, drives the movable jaw on the vise. By comparison, a linear axis on a CNC machine tool is extremely precise. The number of revolutions of the axis drive motor precisely controls the amount of linear motion along the axis. How axis motion is commanded - understanding coordinate systems It would be infeasible for the CNC user to cause axis motion by trying to tell each axis drive motor how many times to rotate in order to command a given linear motion motion amount4. amount4. amount4. (This (This (This would would would be be be like like like having having having to to to figure figure figure out out out how how how many many many turns turns turns of of of the the handle on a table vise will cause the movable jaw to move exactly one inch!) Instead, all CNC controls allow axis motion to be commanded in a much simpler and more a much simpler and more logical logical way way way by by by utilizing utilizing utilizing some some some form form form of of of coordinate coordinate coordinate system. system. system. The The The two two two most most most popular popular coordinate coordinate systems systems systems used used used with with with CNC CNC CNC machines machines machines are are are the the the rectangular rectangular rectangular coordinate coordinate coordinate system system and and the the the polar polar polar coordinate coordinate coordinate system. system. system. By By By far, far, far, the the the more more more popular popular popular of of of these these these two two two is is is the the rectangular coordinate system. The program zero point establishes the point of reference for motion commands in in a a a CNC CNC CNC program. program. program. This This This allows allows allows the the the programmer programmer programmer to to to specify specify specify movements movements movements from from from a a common common location. location. location. If If If program program program zero zero zero is is is chosen chosen chosen wisely, wisely, wisely, usually usually usually coordinates coordinates coordinates needed needed needed for for the program can be taken directly from the print. With this technique, if the programmer wishes the tool to be sent to a position one one inch inch inch to to to the the the right right of of the the the program program program zero zero zero point, point, point, X1.0 X1.0 X1.0 is is is commanded. commanded. If If the the programmer wishes the tool to move to a position one inch above the program zero point, Y1.0 is commanded. The control will automatically determine how many times to rotate each axis drive motor and ball screw to make the axis reach the commanded destination point . This lets the programmer command axis motion in a very logical manner. Refer to fig.2, 3. fig.2, 3. Understanding absolute versus incremental motion All discussions to this point assume that the absolute mode of programming is used6. The most common CNC word used to designate the absolute mode is G90. In the absolute mode, the end points for all motions will be specified from the program zero point. For beginners, this is usually the best and easiest method of specifying end points for motion commands. However, there is another way of specifying end points for axis motion. In the incremental mode (commonly specified by G91), end points for motions are are specified specified specified from from from the the the tool's tool's tool's current current current position, position, position, not not not from from from program program program zero. zero. zero. With With With this this method method of of of commanding commanding commanding motion, motion, motion, the the the programmer programmer programmer must must must always always always be be be asking asking asking "How "How "How far far should should I I I move move move the the the tool?" tool?" tool?" While While While there there there are are are times times times when when when the the the incremental incremental incremental mode mode mode can can can be be very helpful, generally speaking, this is the more cumbersome and difficult method of specifying motion and beginners should concentrate on using the absolute mode. Be Be careful careful careful when when when making making making motion motion motion commands. commands. commands. Beginners Beginners Beginners have have have the the the tendency tendency tendency to to think think incrementally. incrementally. incrementally. If If If working working working in in in the the the absolute absolute absolute mode mode mode (as (as (as beginners beginners beginners should), should), should), the the programmer should always be asking "To what position should the tool be moved?" This position is relative to program zero, NOT from the tools current position. Aside Aside from from from making making making it it it very very very easy easy easy to to to determine determine determine the the the current current current position position position for for for any any command, another benefit of working in the absolute mode has to do with mistakes made during motion commands. In the absolute mode, if a motion mistake is made in one one command command command of of of the the the program, program, program, only only only one one one movement movement movement will will will be be be incorrect. incorrect. incorrect. On On On the the the other other hand, if a mistake is made during incremental movements, all motions from the point of the mistake will also be incorrect. Assigning program zero Keep in mind that the CNC control must be told the location of the program zero point by one means or another. How this is done varies dramatically from one CNC machine and control to another8. One (older) method is to assign program zero in the program. program. With this With this method, the programmer tells the control how far it is from from the the program program zero point to zero point to t he starting position of the machine. This the starting position of the machine. This is is commonly done commonly done with a G92 (or G50) command at least at the beginning of the program and possibly at the beginning of each tool. Another, newer and better way to assign program zero is through some form of offset. Refer to fig.4. Commonly machining center control manufacturers call offsets used to assign program zero fixture offsets. Turning center manufacturers commonly call offsets used to assign program zero for each tool geometry offsets. fig.4 assign program zero through G54 Flexible manufacturing cells A flexible manufacturing cell (FMC) can be considered as a flexible manufacturing subsystem. The following differences exist between the FMC and the FMS: 1. An FMC is not under the direct control of the central computer. Instead, instructions from the central computer are passed to the cell controller. 2. The cell is limited in the number of part families it can manufacture. The following elements are normally found in an FMC: • Cell controller • Programmable logic controller (PLC) • More than one machine tool • A materials handling device (robot or pallet) The The FMC FMC FMC executes executes executes fixed fixed fixed machining machining machining operations operations operations with with with parts parts parts flowing flowing flowing sequentially sequentially between operations. High speed machining The term High Speed Machining (HSM) commonly refers to end milling at high rotational rotational speeds speeds speeds and and and high high high surface surface surface feeds. feeds. feeds. For For For instance, instance, instance, the the the routing routing routing of of of pockets pockets pockets in in aluminum airframe sections with a very high material removal rate1. Refer to fig.5 for the cutting data designations and for mulas. Over the past 60 60 years, HSM years, HSM has been applied to a wide range of metallic and non-metallic workpiece materials, including the the production production production of of of components components components with with with specific specific specific surface surface surface topography topography topography requirements requirements requirements and and machining machining of of of materials materials materials with with with hardness hardness hardness of of of 50 50 50 HRC HRC HRC and and and above. above. above. With With most most steel steel components components hardened hardened hardened to to to approximately approximately approximately 32-42 32-42 32-42 HRC, HRC, HRC, machining machining machining options options options currently currently include: Fig.5 cutting data rough rough machining machining machining and and and semi-finishing semi-finishing semi-finishing of of of the the the material material material in in in its its its soft soft soft (annealed) (annealed) condition heat treatment to achieve the final required hardness = 63 HRC machining of electrodes and Electrical Discharge Machining (EDM) of specific parts of dies and moulds (specifically small radii and deep cavities with limited accessibility for metal cutting cutting tools) tools) tools) finishing finishing finishing and and and super-finishing super-finishing super-finishing of of of cylindrical/flat/cavity cylindrical/flat/cavity cylindrical/flat/cavity surfaces surfaces surfaces with with appropriate cemented carbide, cermets, solid carbide, mixed ceramic or polycrystalline cubic boron nitride (PCBN) For many components, the production process involves a combination of these options options and and and in in in the the the case case case of of of dies dies dies and and and moulds moulds moulds it it it also also also includes includes includes time time time consuming consuming consuming hand hand finishing. Consequently, production costs can be high and lead times excessive. It is typical in the die and mould industry to produce one or just a few tools of the same design. The process involves constant changes to the design, and because of these changes there is also a corresponding need for measuring and reverse engineering. The main criteria are the quality level of the die or mould regarding dimensional, geometric and surface accuracy. If the quality level after machining is poor and if it cannot meet the requirements, there will be a varying need of manual finishing work. This work produces satisfactory surface accuracy, but it always has a negative impact on the dimensional and geometric accuracy. One of the main aims for the die and mould industry has been, and still is, to reduce or eliminate the need for manual polishing and thus improve the quality and shorten the production costs and lead times. Main economical and technical factors for the development of HSM Survival The The ever ever ever increasing increasing increasing competition competition competition in in in the the the marketplace marketplace marketplace is is is continually continually continually setting setting setting new new standards. The demands on time and cost efficiency is getting higher and higher. This has forced the development of new processes and production techniques to take place. HSM provides hope and solutions... Materials The development of new, more difficult to machine materials has underlined the necessity necessity to to to find find find new new new machining machining machining solutions. solutions. solutions. The The The aerospace aerospace aerospace industry industry industry has has has its its its heat heat resistant resistant and and and stainless stainless stainless steel steel steel alloys. alloys. alloys. The The The automotive automotive automotive industry industry industry has has has different different different bimetal bimetal compositions, Compact Graphite Iron and an ever increasing volume of aluminum3. The The die die die and and and mould mould mould industry industry industry mainly mainly mainly has has has to to to face face face the the the problem problem problem of of of machining machining machining high high hardened tool steels, from roughing to finishing. Quality The The demand demand demand for for for higher higher higher component component component or or or product product product quality quality quality is is is the the the result result result of of of ever ever increasing competition. HSM, if applied correctly, offers a number of solutions in this area. Substitution of manual finishing is one example, which is especially important on dies and moulds or components with a complex 3D geometry. Processes The demands on shorter throughput times via fewer setups and simplified flows (logistics) can in most cases, be solved by HSM. A typical target within the die and mould industry is to completely machine fully hardened small sized tools in one setup. Costly and time consuming EDM processes processes can can can also also also be reduced or eliminated with be reduced or eliminated with HSM. Design & development One of the main tools in today's competition is to sell products on the value of novelty. novelty. The The The average average average product product product life life life cycle cycle cycle on on on cars cars cars today today today is is is 4 4 4 years, years, years, computers computers computers and and accessories accessories 1.5 1.5 1.5 years, years, years, hand hand hand phones phones phones 3 3 3 months... months... months... One One One of of of the the the prerequisites prerequisites prerequisites of of of this this development of fast design changes and rapid product development time is the HSM technique. Complex products There is an increase of m ulti-functional multi-functional multi-functional surfaces surfaces surfaces on components, such on components, such a s new as new design design of of of turbine turbine turbine blades blades blades giving giving giving new new new and and and optimized optimized optimized functions functions functions and and and features. features. features. Earlier Earlier designs allowed polishing by hand or with robots (manipulators). Turbine blades with new, more sophisticated designs have to be finished via machining and preferably by HSM . There are also more and more examples of thin walled workpiece that have to be machined (medical equipment, electronics, defense products, computer parts). Production equipment The The strong strong strong development development development of of of cutting cutting cutting materials, materials, materials, holding holding holding tools, tools, tools, machine machine machine tools, tools, controls and especially CAD/CAM features and equipment, has opened possibilities that must be met with new production methods and techniques5. Definition of HSM Salomon's Salomon's theory, theory, theory, "Machining "Machining "Machining with with with high high high cutting cutting cutting speeds..." speeds..." speeds..." on on on which, which, which, in in in 1931, 1931, took out a German patent, assumes that "at a certain cutting speed (5-10 times higher than than in in in conventional conventional conventional machining), machining), machining), the the the chip chip chip removal removal removal temperature temperature temperature at at at the the the cutting cutting cutting edge edge will start to decrease...".See fig.6. Fig.6 chip removal temperature as a result of the cutting speed Given Given the the the conclusion:" ... conclusion:" ... seems seems to to to give give give a a a chance chance chance to to to improve improve improve productivity productivity productivity in in machining with conventional tools at high cutting speeds..." Modern research, unfortunately, has not been able to verify this theory totally. There is a relative decrease of the temperature at the cutting edge that starts at certain cutting speeds for different materials. The decrease is small for steel and cast iron. But larger for aluminum and other non-ferrous metals. The definition of HSM must be based on other factors. Given Given today's today's today's technology, technology, technology, "high "high "high speed" speed" speed" is is is generally generally generally accepted accepted accepted to to to mean mean mean surface surface speeds between 1 and 10 kilometers perminute, or roughly 3 300 to 33 000 feet per minute. Speeds above 10 km/min are in the ultra-high speed category, and are largely the realm of experimental metal cutting. Obviously, the spindle rotations required to achieve these surface cutting speeds are directly related to the diameter of the tools being being used. used. used. One One One trend trend trend which which which is is is very very very evident evident evident today today today is is is the the the use use use of of of very very very large large large cutter cutter diameters for these applications - and this has important implications for tool design. There are many opinions, many myths and many different ways to define HSM. Maintenance and troubleshooting Maintenance for a horizontal MC The The following following following is is a a list list list of of of required required required regular regular regular maintenance maintenance for for a a a Horizontal Horizontal Machining Center as shown in fig.7. Listed are the frequency of service, capacities, and type of fluids required. These required specifications must be followed in order to keep your machine in good working order and protect your warranty. Fig. 7 horizontal machining center Daily Top Top off off off coolant coolant coolant level level level every every every eight eight eight hour hour hour shift shift shift (especially (especially (especially during during during heavy heavy heavy TSC TSC usage). Check way lube lubrication tank level. Clean chips from way covers and bottom pan. Clean chips from tool changer. Wipe spindle taper with a clean cloth rag and apply light oil. Weekly • Check for proper operation of auto drain on filter regulator. See fig. 8 Fig. 8 way lube and pneumatics On machines with the TSC option, clean the chip basket on the coolant tank. Remove the tank cover and remove any sediment inside the tank. Be careful to disconnect the coolant pump from the controller and POWER OFF the control before working on the coolant tank. Do this monthly for machines without the TSC option. Check air gauge/regulator for 85 psi. For For machines machines machines with with with the the the TSC TSC TSC option, option, option, place place place a a a dab dab dab of of of grease grease grease on on on the the the V-flange V-flange V-flange of of tools. Do this monthly for machines without the TSC option. Clean exterior surfaces with mild cleaner. DO NOT use solvents. Check the hydraulic counterbalance pressure according to the machine's specifications. Place a dab of grease on the outside edge of the fingers of the tool changer and run through all tools". Monthly Check oil level in gearbox. Add oil until oil begins dripping from over flow tube at bottom of sump tank. Clean pads on bottom of pallets. Clean Clean the the the locating locating locating pads pads pads on on on the the the A-axis A-axis A-axis and and and the the the load load load station. station. station. This This This requires requires removing the pallet. • Inspect Inspect way way way covers covers covers for for for proper proper proper operation operation operation and and and lubricate lubricate lubricate with with with light light light oil, oil, oil, if if necessary. Six months Replace coolant and thoroughly clean the coolant tank. Check all hoses and lubrication lines for cracking. Annually • Replace the gearbox oil. Drain the oil from the gearbox, and slowly refill it with 2 quarts of Mobil DTE 25 oil. • Check oil filter and clean out residue at bottom for the lubrication chart. Replace air filter on control box every 2 years. Mineral Mineral cutting cutting cutting oils oils oils will will will damage damage damage rubber rubber rubber based based based components components components throughout throughout throughout the the machine. Troubleshooting This section is intended for use in determining the solution to a known problem. Solutions Solutions given given given are are are intended intended intended to to to give give give the the the individual individual individual servicing servicing servicing the the the CNC CNC CNC a a a pattern pattern pattern to to follow in, first, determining the problem's source and, second, solving the problem. Use common sense Many Many problems problems problems are are are easily easily easily overcome overcome overcome by by by correctly correctly correctly evaluating evaluating evaluating the the the situation. situation. situation. All All machine operations are composed of a program, tools, and tooling. You must look at all three before blaming one as the fault area. If a bored hole is chattering because of an overextended boring bar, don't expect the machine to correct the fault. Don't Don't suspect suspect suspect machine machine machine accuracy accuracy accuracy if if if the the the vise vise vise bends bends bends the the the part. part. part. Don't Don't Don't claim claim claim hole hole miss-positioning if you don't first center-drill the hole. Find the problem first Many Many mechanics mechanics mechanics tear tear tear into into into things things things before before before they they they understand understand understand the the the problem, problem, problem, hoping hoping that it will appear as they go. We know this from the fact that more than half of all warranty warranty returned returned returned parts parts parts are are are in in in good good good working working working order. order. If If the the the spindle spindle spindle doesn't doesn't doesn't turn, turn, remember remember that that that the the the spindle spindle spindle is is is connected connected connected to to to the the the gear gear gear box, box, box, which which which is is is connected connected connected to to to the the spindle spindle motor, motor, motor, which which which is is is driven driven driven by by by the the the spindle spindle spindle drive, drive, drive, which which which is is is connected connected connected to to to the the the I/O I/O BOARD, BOARD, which which which is is is driven driven driven by by by the the the MOCON, MOCON, MOCON, which which which is is is driven driven driven by by by the the the processor. processor. processor. The The moral here is doing replace the spindle drives if the belt is broken. Find the problem first; don't just replace the easiest part to get to. Don tinker with the machine There are hundreds of parameters, wires, switches, etc., that you can change in this machine. Don't start randomly changing parts and parameters. Remember, there is a good chance that if you change something, y ou will incorrectly install it or break you will incorrectly install it or break something else in the process6. Consider for a moment changing the processor's board. First, you have to download all parameters, remove a dozen connectors, replace the board, board, reconnect reconnect reconnect and and and reload, reload, reload, and and and if if if you you you make make make one one one mistake mistake mistake or or or bend bend bend one one one tiny tiny tiny pin pin pin it it WON'T WORK. You always need to consider the risk of accidentally damaging the machine anytime you work on it. It is cheap insurance to double-check a suspect part before physically changing it. The less work you do on the machine the better. 。

机床——机械类外文文献翻译、中英文翻译

机床——机械类外文文献翻译、中英文翻译

毕业设计(论文)外文资料翻译系部:专业:姓名:学号:外文出处:English For Electromechanical(用外文写)Engineering附件:1.外文资料翻译译文;2.外文原文。

附件1:外文资料翻译译文机床机床是用于切削金属的机器。

工业上使用的机床要数车床、钻床和铣床最为重要。

其它类型的金属切削机床在金属切削加工方面不及这三种机床应用广泛。

车床通常被称为所有类型机床的始祖。

为了进行车削,当工件旋转经过刀具时,车床用一把单刃刀具切除金属。

用车削可以加工各种圆柱型的工件,如:轴、齿轮坯、皮带轮和丝杠轴。

镗削加工可以用来扩大和精加工定位精度很高的孔。

钻削是由旋转的钻头完成的。

大多数金属的钻削由麻花钻来完成。

用来进行钻削加工的机床称为钻床。

铰孔和攻螺纹也归类为钻削过程。

铰孔是从已经钻好的孔上再切除少量的金属。

攻螺纹是在内孔上加工出螺纹,以使螺钉或螺栓旋进孔内。

铣削由旋转的、多切削刃的铣刀来完成。

铣刀有多种类型和尺寸。

有些铣刀只有两个切削刃,而有些则有多达三十或更多的切削刃。

铣刀根据使用的刀具不同能加工平面、斜面、沟槽、齿轮轮齿和其它外形轮廓。

牛头刨床和龙门刨床用单刃刀具来加工平面。

用牛头刨床进行加工时,刀具在机床上往复运动,而工件朝向刀具自动进给。

在用龙门刨床进行加工时,工件安装在工作台上,工作台往复经过刀具而切除金属。

工作台每完成一个行程刀具自动向工件进给一个小的进给量。

磨削利用磨粒来完成切削工作。

根据加工要求,磨削可分为精密磨削和非精密磨削。

精密磨削用于公差小和非常光洁的表面,非精密磨削用于在精度要求不高的地方切除多余的金属。

车床车床是用来从圆形工件表面切除金属的机床,工件安装在车床的两个顶尖之间,并绕顶尖轴线旋转。

车削工件时,车刀沿着工件的旋转轴线平行移动或与工件的旋转轴线成一斜角移动,将工件表面的金属切除。

车刀的这种位移称为进给。

车刀装夹在刀架上,刀架则固定在溜板上。

溜板是使刀具沿所需方向进行进给的机构。

  1. 1、下载文档前请自行甄别文档内容的完整性,平台不提供额外的编辑、内容补充、找答案等附加服务。
  2. 2、"仅部分预览"的文档,不可在线预览部分如存在完整性等问题,可反馈申请退款(可完整预览的文档不适用该条件!)。
  3. 3、如文档侵犯您的权益,请联系客服反馈,我们会尽快为您处理(人工客服工作时间:9:00-18:30)。

机床加工外文翻译参考文献(文档含中英文对照即英文原文和中文翻译)基本加工工序和切削技术基本加工的操作机床是从早期的埃及人的脚踏动力车和约翰·威尔金森的镗床发展而来的。

它们为工件和刀具提供刚性支撑并可以精确控制它们的相对位置和相对速度。

基本上讲,金属切削是指一个磨尖的锲形工具从有韧性的工件表面上去除一条很窄的金属。

切屑是被废弃的产品,与其它工件相比切屑较短,但对于未切削部分的厚度有一定的增加。

工件表面的几何形状取决于刀具的形状以及加工操作过程中刀具的路径。

大多数加工工序产生不同几何形状的零件。

如果一个粗糙的工件在中心轴上转动并且刀具平行于旋转中心切入工件表面,一个旋转表面就产生了,这种操作称为车削。

如果一个空心的管子以同样的方式在内表面加工,这种操作称为镗孔。

当均匀地改变直径时便产生了一个圆锥形的外表面,这称为锥度车削。

如果刀具接触点以改变半径的方式运动,那么一个外轮廓像球的工件便产生了;或者如果工件足够的短并且支撑是十分刚硬的,那么成型刀具相对于旋转轴正常进给的一个外表面便可产生,短锥形或圆柱形的表面也可形成。

平坦的表面是经常需要的,它们可以由刀具接触点相对于旋转轴的径向车削产生。

在刨削时对于较大的工件更容易将刀具固定并将工件置于刀具下面。

刀具可以往复地进给。

成形面可以通过成型刀具加工产生。

多刃刀具也能使用。

使用双刃槽钻钻深度是钻孔直径5-10倍的孔。

不管是钻头旋转还是工件旋转,切削刃与工件之间的相对运动是一个重要因数。

在铣削时一个带有许多切削刃的旋转刀具与工件接触,工件相对刀具慢慢运动。

平的或成形面根据刀具的几何形状和进给方式可能产生。

可以产生横向或纵向轴旋转并且可以在任何三个坐标方向上进给。

基本机床机床通过从塑性材料上去除屑片来产生出具有特别几何形状和精确尺寸的零件。

后者是废弃物,是由塑性材料如钢的长而不断的带状物变化而来,从处理的角度来看,那是没有用处的。

很容易处理不好由铸铁产生的破裂的屑片。

机床执行五种基本的去除金属的过程:车削,刨削,钻孔,铣削。

所有其他的去除金属的过程都是由这五个基本程序修改而来的,举例来说,镗孔是内部车削;铰孔,攻丝和扩孔是进一步加工钻过的孔;齿轮加工是基于铣削操作的。

抛光和打磨是磨削和去除磨料工序的变形。

因此,只有四种基本类型的机床,使用特别可控制几何形状的切削工具1.车床,2.钻床,3.铣床,4.磨床。

磨削过程形成了屑片,但磨粒的几何形状是不可控制的。

通过各种加工工序去除材料的数量和速度是巨大的,正如在大型车削加工,或者是极小的如研磨和超精密加工中只有面的高点被除掉。

一台机床履行三大职能:1.它支撑工件或夹具和刀具2.它为工件和刀具提供相对运动3.在每一种情况下提供一系列的进给量和一般可达4-32种的速度选择。

加工速度和进给速度,进给量和切削深度是经济加工的三大变量。

其他的量数是攻丝和刀具材料,冷却剂和刀具的几何形状,去除金属的速度和所需要的功率依赖于这些变量。

切削深度,进给量和切削速度是任何一个金属加工工序中必须建立的机械参量。

它们都影响去除金属的力,功率和速度。

切削速度可以定义为在旋转一周时速度记录面相对任何瞬间呈辐射状扩散的针,或是两个相邻沟槽的距离。

切削深度是进入的深度和沟槽的深度。

在车床中心的车削在机动车床上完成的基本操作已被介绍了。

那些用单点刀具在外表面的操作称为车削。

除了钻孔,铰孔,研磨内部表面的操作也是由单点刀具完成的。

所有的加工工序包括车削,镗孔可以被归类为粗加工,精加工或半精加工。

精加工是尽可能快而有效的去除大量材料,而工件上留下的一小部分材料用于精加工。

精加工为工件获得最后尺寸,形状和表面精度。

有时,半精加工为精加工留下预定的一定量的材料,它是先于精加工的。

一般来说,较长的工件同时被一个或两个车床中心支撑。

锥形孔,所谓的中心孔,两端被钻的工件适于车床中心-通常沿着圆柱形工件的轴线。

工件接近为架的那端通常由尾架中心支撑,在靠近主轴承的那端由主轴承中心支撑或由爪盘夹紧。

这种方法可以牢固的加紧工件并且能顺利地将力传给工件;由卡盘对工件提供的辅助支撑减少切削时发生的颤振趋势,如果能小心准确地采用卡盘支撑工件的方法,则可以得到精确的结果。

在两个中心之间支撑工件可以得到非常精确的结果。

工件的一端已被加工,那么工件便可车削了。

在车床上加工另一端,中心孔充当精确定位面和承载工件重量和抵制切削力的支撑面。

当工件由于任何一原因从车床上移除后,中心孔将准确地使工件回到这个车床上或另一个车床上或一个圆柱磨床上。

工件不允许被卡盘和车床中心夹在主轴承上。

然而首先想到的是一个快速调整卡盘上工件的方法,但这是不允许的因为在由卡盘夹持的同时也由车床中心支撑是不可能的。

由车床中心提供的调整将不能持续并且爪盘的压力会损坏中心孔和车床中心,甚至是车床主轴。

浮动的爪盘为上述陈述提供了一个例外,它几乎完全使用在高生产工作上,这些卡盘是真正的工作驱动者并且不为同样的目的如普通的三爪,四爪卡盘使用。

而大直径的工件有时装在两个中心,它们最好有由面板夹持在主轴承尾部来顺利得到能量转换;许多车床夹头并不能足量的转换能量,虽然可以作为特殊的能量转换。

机械加工介绍作为产生形状的一种方法,机械加工是所有制造过程中最普遍使用的而且是最重要的方法。

机械加工过程是一个产生形状的过程,在这过程中,驱动装置使工件上的一些材料以切屑的形式被去除。

尽管在某些场合,工件无支承情况下,使用移动式装备来实现加工,但大多数的机械加工是通过既支承工件又支承刀具的装备来完成。

小批量,低成本。

机械加工在制造业上有两个应用。

是铸造,锻造和压力工作,产生每一个特殊形状,甚至一个零件,几乎总有较高的模具成本。

焊接的形状很大程度上取决于原材料。

通过利用总成本高但没有特殊模具的设备,加工是有可能的;从几乎任何形式的原材料开始,只要外部尺寸足够大,由任意材料设计形状。

因此加工是首选的方法,当生产一个或几个零件甚至在大批量生产时,零件的设计在逻辑上导致铸造,锻造或冲压制品。

高精度,表面精度。

机械加工的第二个应用是基于可能的高精度和表面精度的。

如果在其他工序中大批量生产,很多低量零件会产生出低的但可接受的公差。

另一方面,许多零件由一些大变形过程产生一般的形状,并且只在具有很高精度的选定面加工。

举例来说,内线流程是很少产生任何方式以外的其他机械加工并且紧接着压力操作后零件上的小洞可能被加工。

主要的切削参数在切削时基本工具工作的关系充分描述的方法有4个因素:刀具几何形状,切削速度和切削深度。

刀具必须由适当的材料做成;它必须有一定的强度,粗糙度,硬度和抗疲劳度。

刀具几何形状由面和角度描述,对每一种切削操作都是正确的。

切削速度是指切削刃通过工作面的速度,它已每分钟通过的英尺数表示。

对于加工效率,切削速度相对于特殊工作组合必须具有适当规模。

一般来讲,工件越硬,速度越小。

进给是刀具进入工件的速率。

当工件或刀具旋转时,进给量的单位是英寸每转。

当刀具或工件往复移动时,进给量的单位是英寸没次,总的来说,在其他相似情况下进给量与切削速度成反比。

切削速度用英寸表示,是刀具进入工件的距离表示的,它是指车削时屑片的宽度或是直线切削时屑片的厚度。

粗加工时切削深度比精加工的切削深度大。

切削参数的改变对切削温度的影响在金属切削作业中热量产生于主要和第二变形区而这些结果导致了复杂温度遍布于刀具,工件和屑片。

一个典型的等温先如图所示,它可以看出正如预测的,当工件材料经历主要变形,被减切时,有一个非常大温度梯度遍布于屑片的整个宽度。

当第二变形区的屑片还有一小段距离就达到了最大温度。

因为几乎所有的工作都以金属切削转化为热量而完成,可以预测去除每一单位体积的金属所增加的能量消耗将会提高切削温度。

因此在所有其他参数不变,前角变大时,将减少去除每单位体积金属的能量和切削温度。

当考虑到增加未形成屑片的厚度和速度,情况就更复杂了。

增加切削厚度往往会大大影响热量传给工件,刀具的多少,而且会使屑片停留在一个固定数额,同时切削温度的变化也会很小,可是增加切削速度会减少传递给工件的热量,同时这将增大屑片主要变形的温升。

此外,第二变形区是比较小的,在这个变形区会提高温度。

切削参数的其他变化几乎不影响去除每单位体积的能量消耗和切削温度。

因此已经表明,即使是切削温度的小规模变化对刀具磨损率也有重大影响,从切削数据来估计切削温度是恰当的。

检测高速钢工具最直接最准确的方法,特伦特给出了高速钢工具温度分布的详细资料。

该技术是基于高速钢刀具的数据检测并与对热历史的微观变化有关。

特伦特已经描述了切削温度的测量和加工大范围工件时高速钢工具的温度分布。

使用扫描电子显微镜来研究精细尺度微观结构变化,这项技术已得到了进一步发展。

这项技术也用于研究高速钢单点车刀和麻花钻的温度分布,刀具磨损脆性断裂已经得到了处理,刀具磨损基本上有三个类型。

后刀面磨损,边界磨损和前刀面磨损。

刀面磨损发生在主切削刃和次切削刃。

主切削刃负责去除大量金属,这增加了切削力和温度,如果任其发展会导致刀具和工件的振动,这就再不能高效率地切削了。

次切削刃决定工件尺寸和表面精度,后刀面的磨损会导致大量产品出现较差的表面精度。

根据实际切削条件,刀具不可用的主要原因在于主刀面先于次刀面的磨损非常大,这导致了一个不可接受部分的产生。

因为刀具的应力分布,刚开始滑动时,滑动区域的摩擦力在屑片和面之间达到最大,最后摩擦力便为零。

因此磨料磨损发生在这个区域,在屑片与相离处更多的磨损发生在与该区域相邻处,这比相邻于这点的更多。

这导致了刀具面的局部点蚀与这面有一定距离,这面通常有一部分是圆弧形的。

在许多方面并基于实际切削条件,边界磨损相比后刀面是一个较不严重的磨损,因此刀面磨损是一种较常见磨钝标准。

然后,由于各样作者表明,伴随着切削速度的增加面温度的增加量多于刀面的增加量,而由于温度变化严重影响任一类型的磨损率,边界磨损通常发生在较高切削速度的情况下。

刀具与未切削面相接触的地方,主刀面磨损的尾部的磨损比沿着剩余磨损面的地方更明显。

这是因为局部影响如未切削面是由先前的切削,氧化规模,局部高温所形成的加工硬化而造成的。

这个局部磨损一般与边界磨损有关,有时还很严重。

虽然出现凹口不会严重影响刀具的切削性能,凹口是往往比较深,如果继续切削刀具很可能断裂。

如果任何形式的渐进磨损让其戏剧性的继续存在,刀具将面临灾难性的故障,如刀具再不能切割,在好的情况下,工件报废,最坏时,机械工具可能造成损坏。

对于硬质合金刀具和各类型的磨损,在出现灾难性故障之前达到最长使用使用寿命的极限。

但对于高速钢切削工具的磨损是不均匀的,目前已发现当磨损继续并甚至出现灾难性故障时,便可得到最有意义的和可以复制的结果,当然在实践中,切削时间远远少于故障时间。

相关文档
最新文档