外文翻译-机械设计
机械设计外文翻译--车床和铣床
中文4285字附录1LATHES & MILLINGA shop that is equipped with a milling machine and an engine lathe can machine almost any type of product of suitable size.The basic machines that are designed primarily to do turning，facing and boring are called lathes. Very little turning is done on other types of machine tools，and none can do it with equal facility. Because lathe can do boring，facing，drilling，and reaming in addition to turning，their versatility permits several operations to be performed with a single setup of the workpiece. This accounts for the fact that lathes of various types are more widely used in manufacturing than any other machine tool.Lathes in various forms have existed for more than two thousand years. Modern lathes date from about 1797，when Henry Maudsley developed one with a leads crew. It provided controlled，mechanical feed of the tool. This ingenious Englishman also developed a change gear system that could connect the motions of the spindle and leadscrew and thus enable threads to be cut.Lathe Construction.The essential components of a lathe are depicted in the block diagram of picture. These are the bed，headstock assembly，tailstock assembly，carriage assembly，quick-change gearbox，and the leadscrew and feed rod.The bed is the back bone of a lathe. It usually is made of well-normalized or aged gray or nodular cast iron and provides a 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. Because several other components are mounted and/or move on the ways they must be made with precision to assure accuracy of alignment. Similarly，proper precaution should betaken 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 ways on most modern lathes are surface hardened tooffer greater resistance to wear and abrasion.The headstock is mounted in a fixed position on the inner ways at one end of the lathe bed. It provides a powered means of rotating the work at various speeds. It consists，essentially，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 eight to eighteen 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. Along- itudinal hole extends through the spindle so that long bar stock can be fed through it. The size of this hole is an important size dimension of a lathe because it determines the maximum size of bar stock that can be machined when the material must be fed through the spindle.The inner end of the spindle protrudes from the gear box and contains a means for mounting various types of chucks，face plates，and dog plates on it. Whereas small lathes often employ a threaded section to which the chucks are screwed，most large lathes utilize either cam-lock or key-drive taper noses. These provide a large-diameter taper that assures the accurate alignment of the chuck，and a mechanism that permits the chuck or face plate to be locked or unlocked in position without the necessity of having to rotate these heavy attachments.Power is supplied to the spindle by means of an electric motor through a V-belt or silent-chain drive. Most modern lathes have motors of from 5 to15 horsepower to provide adequate power for carbide and ceramic tools at their high cutting speeds.The tailstock 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. Thistransverse motion permits aligning the tailstock and headstock spindles and provides a method of turning tapers. The third major component of the assembly is the tailstock quill. This is a hollow steel cylinder，usually about2 to3 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 open end of the quill hole terminates in a Morse taper in which a lathe center，or various tools such as drills，can be held. A graduated scale，several inches in length，usually is engraved on the outside of the quill to aid in controlling its motion in and out of the upper casting. A locking device permits clamping the quill in any desired position.The carriage assembly provides the means for mounting and moving cutting tools. The carriage is a relatively flat H-shaped casting that rests and moves on the outer set of ways on the bed. The transverse bar of the carriage contains ways on which the cross slide is mounted and can be moved by means of a feed screw that is controlled by a small hand wheel and a graduated dial. Through the cross slide a means is provided for moving the lathe tool in the direction normal to the axis of rotation of the work.On most lathes the tool post actually is mounted on a compound rest. This consists of abase，which is mounted on the cross slide so that it can be pivoted about a vertical axis，and an upper casting. The upper casting is mounted on ways on this base so that it can be moved back and forth and controlled by means of a short lead screw operated by a hand wheel and a calibrated dial.Manual and powered motion for the carriage，and powered motion for the cross slide，is provided by mechanisms within the apron，attached to the front of the carriage. Manual movement of the carriage along the bed is effected by turning a hand wheel on the front of the apron，which is geared to a pinion on the back side. This pinion engages a rack that is attached beneath the upper front edge of the bed in an inverted position.To impart powered movement to the carriage and cross slide，a rotating feed rod is provided. The feed rod，which contains a keyway through out most of its length，passes through the two reversing bevel pinions and is keyed to them . Either pinioncam be brought into mesh with amating bevel gear by means of the reversing lever on the front of the apron and thus provide “forward” or “reverse” power to the carriage. Suitable clutches connect either the rack pinion orthe cross-slide screw to provide longitudinal motion of the carriage or transverse motion of cross slide.For cutting threads，a second means of longitudinal drive is provided by a lead screw. Whereas motion of the carriage when driven by the feed-rod mechanism takes place through a friction clutch in which slippage is possible，motion through the lead screw is by a direct，mechanical connection between the apron and the lead screw. This is achieved by a split nut. By means of a clamping lever on the front of the apron，the split nut can be closed around the lead screw. With the split nut closed，the carriage is moved along the lead screw by direct drive without possibility of slippage.Modern lathes have a quick-change gear box. The input end of this gearbox is driven from the lathe spindle by means of suitable gearing. The out put end of the gear box is connected to the feed rod and lead screw. Thus，through this gear train，leading from the spindle to the quick-change gearbox，thence to the lead screw and feed rod，and then to the carriage，the cutting tool can be made to move a specific distance，either longitudinally or transversely，for each revolution of the spindle. A typical lathe provides，through the feed rod，forty-eight feeds ranging from 0.002 inch to0.118 inch per revolution of the spindle，and，through the lead screw，leads for cutting forty-eight different threads from 1.5 to 92perinch.On some older and some cheaper lathes，one or two gears in the gear train between the spindle and the change gear box must be changed in order to obtain a full range of threads and feeds.Milling is a basic machining process in which the surface is generated by the progressive formation and removal of chips of material from the workpiece as it is fed to a rotating cutter in a direction perpendicular to the axis of the cutter. .In some cases the workpiece is stationary and the cutter is fed to the work. In most instances a multiple-tooth cutter is used so that the metal removal rate is high，and frequently the desired surface is obtained in a single pass of the work.The tool used in milling is known as a milling cutter. It usually consists of a cylindrical body which rotates on its axis and contains equally spaced peripheral teeth that intermittently engage and cut the workpiece. In some cases the teeth extend part way across one or both ends of the cylinder.Because the milling principle provides rapid metal removal and can produce good surface finish，it is particularly well-suited for mass-production work，and excellent milling machines have been developed for this purpose. However，very accurate and versatile milling machines of a general-purpose nature also have been developed that are widely used in job-shop and tool and die work. A shop that is equipped with a milling machine and an engine lathe can machine almost any type of product of suitable size.Types of Milling Operations. Milling operations can be classified into two broad categories，each of which has several variations：1.In peripheral milling a surface is generated by teeth located in the periphery of the cutter body；the surface is parallel with the axis of rotation of the cutter. Both flat and formed surfaces can be produced by this method. The cross section of the resulting surface corresponds to the axial contour of the cutter. This procedure often is called slab milling.1.In face milling the generated flat surface is at right angles to the cutteraxis and is thecombined result of the actions of the portions of the teeth located on both the periphery and thewith the face portions providing a finishing action.The basic concepts of peripheral and face milling are illustrated in Fig. Peripheral milling operations usually are performed on machines having horizontal spindles，whereas face milling is done on both horizontal-and vertical-spindle machines.Surface Generation in Milling. Surfaces can be generated in milling by two distinctly different methods depicted in Fig. Note that in up milling the cutter rotatesagainst the direction of feed the workpiece，whereas in down milling the rotation is in the same direction as the feed .As shown in Fig., the method of chip formation is quite different in the two cases. In up milling the c hip is very thin at the beginning, where the tooth first contacts the work，and increases in thickness, be-coming a maximum where the tooth leaves the work. The cutter tends to push the work along and lift it upward from the table. This action tends to eliminate any effect of looseness in the feed screw and nut of the milling machine table and results in a smooth cut. However, the action also tends to loosen the work from the clamping device so that greater clamping forcers must be employed. In addition, the smoothness of the generated surface depends greatly on the sharpness of the cutting edges.In down milling，maximum chip thickness occurs close to the point at which the tooth contacts the work. Because the relative motion tends to pull the workpiece into the cutter，all possibility of looseness in the table feed screw must be eliminated if down milling is to be used. It should never be attempted on machines that are not designed for this type of milling. In as mush as the material yields in approximately a tangential direction at the end of the tooth engagement，there is much less tendency for the machined surface to show tooth marks than when up milling is used. Another consider able advantage of down milling is that the cutting force tends to hold the work against the machine table，permitting lower clamping force to be employed. This is particularly advantageous when milling thin workpiece or when taking heavy cuts.Sometimes a disadvantage of down milling is that the cutter teeth strike against the surface of the work at the beginning of each chip. When the workpiece has a hard surface，such as castings do，this may cause the teeth to dull rapidly.Milling Cutters. Milling cutters can be classified several ways. One method is to group them into two broad classes，based on tooth relief，as follows：1. Profile-cutters have relief provided on each tooth by grinding a small land back of the cutting edge. The cutting edge may be straight or curved.2.In form or cam-relieved cutters the cross section of each tooth is an eccentric curve behind the cutting edge，thus providing relief. All sections of the eccentric relief，parallel with the cutting edge，must have the same contour as the cutting edge. Cutters of this type are sharpened by grinding only the face of the teeth，with the contour of the cutting edge thus remaining unchanged.Another useful method of classification is according to the method of mounting the cutter. Arbor cutters are those that have a center hole so they can be mounted on an arbor. Shank cutters have either tapered or straight integral shank. Those with tapered shanks can be mounted directly in the milling machine spindle，whereas straight-shank cutters are held in a chuck. Facing cuttersusually are bolted to the end of a stub arbor.Types of Milling Cutters. Plain milling cutters are cylindrical or disk-shaped，having straight or helical teeth on the periphery. They are used for milling flat surfaces. This type of operation is called plain or slab milling. Each tooth in a helical cutter engages the work gradually，and usually more than one tooth cuts at a given time. This reduces shock and chattering tendencies and promotes a smoother surface. Consequently，this type of cutter usually is preferred over one with straight teeth. Side milling cutters are similar to plain milling cutters except that the teeth extend radially part way across one or both ends of the cylinder toward the center. The teeth may be either straight or helical. Frequently these cutters are relatively narrow，being disklike in shape. Two or more side milling cutters often are spaced on an arbor to make simultaneous，parallel cuts，in an operation called straddle milling.Interlocking slotting cutters consist of two cutters similar to side mills，but made to operate as a unit for milling slots. The two cutters are adjusted to the desired width by inserting shims between them.Staggered-tooth milling cutters are narrow cylindrical cutters having staggered teeth，and with alternate teeth having opposite helix angles. They are ground to cut only on the periphery，but each tooth also has chip clearance ground on the protruding side. These cutters have a free cutting action that makes them particularly effective in milling deep slots. Metal-slitting saws are thin，plain milling cutters，usually from 1/32 to 3/16 inch thick，which have their sides slightly“dished”to provide clearance and prevent binding. They usually have more teeth per inch of diameter than ordinaryplain milling cutters and are used for milling deep，narrow slots and for cutting-off operations.附录2车床和铣床车间里拥有一台车床和一台普通铣床就能加工出具有适合尺寸的各种产品。
机械专业毕业设计外文翻译10
翻译部分英文部分ADV ANCED MACHINING PROCESSESAs the hardware of an advanced technology becomes more complex, new and visionary approaches to the processing of materials into useful products come into common use. This has been the trend in machining processes in recent years.. Advanced methods of machine control as well as completely different methods of shaping materials have permitted the mechanical designer to proceed in directions that would have been totally impossible only a few years ago.Parallel development in other technologies such as electronics and computers have made available to the machine tool designer methods and processes that can permit a machine tool to far exceed the capabilities of the most experienced machinist.In this section we will look at CNC machining using chip-making cutting tools. CNC controllers are used to drive and control a great variety of machines and mechanisms, Some examples would be routers in wood working; lasers, plasma-arc, flame cutting, and waterjets for cutting of steel plate; and controlling of robots in manufacturing and assembly. This section is only an overview and cannot take the place of a programming manual for a specific machine tool. Because of the tremendous growth in numbers and capability of comp uters ,changes in machine controls are rapidly and constantly taking place. The exciting part of this evolution in machine controls is that programming becomeseasier with each new advanced in this technology.Advantages of Numerical ControlA manually operated machine tool may have the same physical characteristics as a CNC machine, such as size and horsepower. The principles of metal removal are the same. The big gain comes from the computer controlling the machining axes movements. CNC-controlled machine tools can be as simple as a 2-axis drilling machining center (Figure O-1). With a dual spindle machining center, the low RPM, high horsepower spindle gives high metal removal rates. The high RPM spindle allows the efficient use of high cutting speed tools such as diamonds and small diameter cutters (Figure O-2). The cutting tools that remove materials are standard tools such as milling cutters, drills, boring tools, or lathe tools depending on the type of machine used. Cutting speeds and feeds need to be correct as in any other machining operation. The greatest advantage in CNC machining comes from the unerring and rapid positioning movements possible. A CNC machine does dot stop at the end of a cut to plan its next move; it does not get fatigued; it is capable of uninterrupted machining error free, hour after hour. A machine tool is productive only while it is making chips.Since the chip-making process is controlled by the proper feeds and speeds, time savings can be achieved by faster rapid feed rates. Rapid feeds have increased from 60 to 200 to 400 and are now often approaching 1000 inches per minute (IPM). These high feed rates can pose a safety hazard to anyone within the working envelope of the machine tool.Complex contoured shapes were extremely difficult to product prior to CNC machining .CNC has made the machining of these shapes economically feasible. Design changes on a part are relatively easy to make by changing the program that directs the machine tool.A CNC machine produces parts with high dimensional accuracy and close tolerances without taking extra time or special precautions, CNC machines generally need less complex work-holding fixtures, which saves time by getting the parts machined sooner. Once a program is ready and production parts, each part will take exactly the same amount of time as the previous one. This repeatability allows for a very precise control of production costs. Another advantage of CNC machining is the elimination of large inventories; parts can be machined as needs .In conventional production often a great number of parts must be made at the same time to be cost effective. With CNC even one piece can be machined economically .In many instances, a CNC machine can perform in one setup the same operations that would require several conventional machines.With modern CNC machine tools a trained machinist can program and product even a single part economically .CNC machine tools are used in small and large machining facilities and range in size from tabletop models to huge machining centers. In a facility with many CNC tools, programming is usually done by CNC programmers away from the CNC tools. The machine control unit (MCU) on the machine is then used mostly for small program changes or corrections. Manufacturing with CNC tools usually requires three categories of persons. The first is the programmer, who is responsible for developing machine-ready code. The next person involved is the setup person, who loads the raw stork into the MCU, checks that the co rrect tools are loaded, and makes the first part. The third person is the machine and unloads the finished parts. In a small company, one person is expected to perform all three of these tasks.CNC controls are generally divided into two basic categories. One uses a ward address format with coded inputs such as G and M codes. The other users a conversational input; conversational input is also called user-friendly or prompted input. Later in this section examples of each of these programming formats in machining applications will be describes.CAM and CNCCAM systems have changed the job of the CNC programmer from one manually producing CNC code to one maximizing the output of CNC machines. Since CNC machine tools are made by a great number of manufacturers, many different CNC control units are in use. Control units from different manufacturers use a variety of program formats and codes. Many CNC code words are identical for different controllers, but a great number vary from one to another.To produce an identical part on CNC machine tools with different controllers such as one by FANCU, OKUMA or DYNAPATH, would require completely different CNC codes. Each manufacturer is constantly improving and updating its CNC controllers. These improvements often include additional code words plus changes in how the existing code works.A CAM systems allows the CNC programmer to concentrate on the creation of an efficient machining process, rather then relearning changed code formats. A CNC programmer looks atthe print of a part and then plans the sequence of machining operations necessary to make it (Figure O-3). This plan includes everything, from the selection of possible CNC machine tools, to which tooling to use, to how the part is held while machining takes place. The CNC programmer has to have a thorough understanding of all the capacities and limitations of the CNC machine tools that a program is to be made for. Machine specifications such as horsepower, maximum spindle speeds, workpiece weight and size limitations, and tool changer capacity are just some of the considerations that affect programming.Another area of major importance to the programmer is the knowledge of machining processes. An example would be the selection of the surface finish requirement specified in the part print. The sequence of machining processes is critical to obtain acceptable results. Cutting tool limitations have to be considered and this requires knowledge of cutting tool materials, tool types, and application recommendations.A good programmer will spend a considerable amount of time in researching the rapidly growing volume of new and improved tools and tool materials. Often the tool that was on the cutting edge of technology just two years ago is now obsolete. Information on new tools can come from catalogs or tool manufacturers' tooling engineers. Help in tool selection or optimum tool working conditions can also be obtained from tool manufacturer software. Examples would be Kennametal's "TOOLPRO", software designed to help select the best tool grade, speed, and feed rates for different work materials in turning application. Another very important feature of "TOOLPRO" is the display of the horsepower requirement for each machining selection. This allow the programmer to select a combination of cutting speed, feed rate, and depth of cut that equals the machine's maximum horsepower for roughing cuts. For a finishing cut, the smallest diameter of the part being machined is selected and then the cutting speed varied until the RPM is equal to the maximum RPM of the machine. This helps in maximizing machining efficiency. Knowing the horsepower requirement for a cut is critical if more than one tool is cutting at the same time.Software for a machining center application would be Ingersoll Tool Company's "Actual Chip Thickness", a program used to calculate the chip thickness in relation to feed-per-tooth for a milling cutter, especially during a shallow finishing cut. Ingersoll's "Rigidity Analysis" software ealculates tool deflection for end mills as a function of tool stiffness and tool force.To this point we looked at some general qualifications that a programmer should possess. Now we examine how a CAM system works. Point Control Company's SmartCam system uses the following approach. First, the programmer makes a mental model of the part to be machined. This includes the kind of machining to be performed-turning or milling. Then the part print is studied to develop a machining sequence, roughing and finishing cuts, drilling, tapping, and boring operations. What work-holding device is to be used, a vise or fixture or clamps? After these considerations, computer input can be started. First comes the creation of a JOBPLAN. This JOBPLAN consists of entries such as inch or metric units, machine type, part ID, type of workpiece material, setup notes, and a description of the required tools.This line of information describes the tool by number, type, and size and includes theappropriate cutting speed and feed rate. After all the selected tools are entered, the file is saved.The second programming step is the making of the part. This represents a graphic modeling of the projected machining operation. After selecting a tool from the prepared JOBPLAN, parameters for the cutting operation are entered. For a drill, once the coordinate location of the hole and the depth are given, a circle appears on that spot. If the location is incorrect, the UNDO command erases this entry and allows you to give new values for this operation. When an end mill is being used, cutting movements (toolpath) are usually defined as lines and arcs. As a line is programmed, the toolpath is graphically displayed and errors can be corrected instantly.At any time during programming, the command SHOWPATH will show the actual toolpath for each of the programmed tools. The tools will be displayed in the sequence in which they will be used during actual machining. If the sequence of a tool movement needs to be changed, a few keystrokes will to that.Sometimes in CAM the programming sequence is different from the actual machining order. An example would be the machining of a pocket in a part. With CAM, the finished pocket outline is programmed first, then this outline is used to define the ro ughing cuts to machine the pocket. The roughing cuts are computer generated from inputs such as depth and width of cut and how much material to leave for the finish cut. Different roughing patterns can be tried out to allow the programmer to select the most efllcient one for the actual machining cuts. Since each tool is represented by a different color, it is easy to observe the toolpath made by each one.A CAM system lets the programmer view the graphics model from varying angles, such as a top, front, side, or isometric view. A toolpath that looks correct from a top view, may show from a front view that the depth of the cutting tool is incorrect. Changes can easily be made and seen immediately.When the toolpath and the sequence of operations are satisfactory, machine ready code has to be made. This is as easy as specifying the CNC machine that is to be used to machine the part. The code generator for that specific CNC machin e during processing accesses four different files. The JOBPLAN file for the tool information and the GRAPHICE file for the toolpath and cutting sequence. It also uses the MACHINE DEFINE file which defines the CNC code words for that specific machine. This file also supplies data for maximum feed rates, RPM, toolchange times, and so on. The fourth file taking part in the code generating process is the TEMPLATE file. This file acts like a ruler that produces the CNC code with all of its parts in the right place and sequence. When the code generation is complete, a projected machining time is displayed. This time is calculated from values such as feed rates and distances traveled, noncutting movements at maximum feed rates between points, tool change times, and so on. The projected machining time can be revised by changing tooling to allow for higher metal removal rates or creating a more efficient toolpath. This display of total time required can also be used to estimate production costs. If more then one CNC machine tool is available to machine this part, making code and comparing the machining time may show that one machine is more efficient than the others.CAD/CAMAnother method of creating toolpath is with the use of a Computer-aided Drafting (CAD) file. Most machine drawings are created using computers with the description and part geometry stored in the computer database. SmartCAM, though its CAM CONNECTION, will read a CAD file and transfer its geometry represents the part profile, holes, and so on. The programmer still needs to prepare a JOBPLAN with all the necessary tools, but instead of programming a profile line by line, now only a tool has to be assigned to an existing profile. Again, using the SHOWPA TH function will display the toolpath for each tool and their sequence. Constant research and developments in CAD/CAM interaction will change how they work with each other. Some CAD and CAM programs, if loaded on the same computer, make it possible to switch between the two with a few keystrokes, designing and programming at the same time.The work area around the machine needs to be kept clean and clear of obstructions to prevent slipping or tripping. Machine surfaces should not be used as worktables. Use proper lifting methods to handle heavy workpieces, fixtures, or heavy cutting tools. Make measurements only when the spindle has come to a complete standstill. Chips should never be handled with bare hands.Before starting the machine make sure that the work-holding device and the workpiece are securely fastened. When changing cutting tools, protect the workpiece being machined from damage, and protect your hands from sharp cutting edges. Use only sharp cutting tools. Check that cutting tools are installed correctly and securely.Do not operate any machine controls unless you understand their function and what the y will do.The Early Development Of Numerically Controlled Machine ToolsThe highly sophisticated CNC machine tools of today, in the vast and diverse range found throughout the field of manufacturing processing, started from very humble beginnings in a number of the major industrialized countries. Some of the earliest research and development work in this field was completed in USA and a mention will be made of the UK's contribution to this numerical control development.A major problem occurred just after the Second World War, in that progress in all areas of military and commercial development had been so rapid that the levels of automation and accuracy required by the modern industrialized world could not be attained from the lab our intensive machines in use at that time. The question was how to overcome the disadvantages of conventional plant and current manning levels. It is generally ackonwledged that the earliest work into numerical control was the study commissioned in 1947 by the US governme nt. The study's conclusion was that the metal cutting industry throughout the entire country could not copy with the demands of the American Air Force, let alone the rest of industry! As a direct result of the survey, the US Air Force contracted the Persons Corporation to see if they could develop a flexible, dynamic, manufacturing system which would maximize productivity. TheMassachusetts Institute of Technology (MIT) was sub-contracted into this research and development by the Parsons Corporation, during the period 1949-1951,and jointly they developed the first control system which could be adapted to a wide range of machine tools. The Cincinnati Machine Tool Company converted one of their standard 28 inch "Hydro-Tel" milling machines or a three-axis automatic milling made use of a servo-mechanism for the drive system on the axes. This machine made use of a servomechanism for the drive system on the axes, which controlled the table positioning, cross-slide and spindle head. The machine cab be classified as the first truly three axis continuous path machine tool and it was able to generate a required shape, or curve, by simultaneous slide way motions, if necessary.At about the same times as these American advances in machine tool control were taking Place, Alfred Herbert Limited in the United Kingdom had their first Mutinous path control system which became available in 1956.Over the next few years in both the USA and Europe, further development work occurred. These early numerical control developments were principally for the aerospace industry, where it was necessary to cut complex geometric shapes such as airframe components and turbine blades. In parallel with this development of sophisticated control systems for aerospace requirements, a point-to-point controller was developed for more general machining applications. These less sophisticated point-to-point machines were considerably cheaper than their more complex continuous path cousins and were used when only positional accuracy was necessary. As an example of point-to-point motion on a machine tool for drilling operations, the typical movement might be fast traverse of the work piece under the drill's position-after drilling the hole, anther rapid move takes place to the next hole's position-after retraction of the drill. Of course, the rapid motion of the slideways could be achieved by each axis in a sequential and independent manner, or simultaneously. If a separate control was utilisec for each axis, the former method of table travel was less esse ntial to avoid any backlash in the system to obtain the required degree of positional accuracy and so it was necessary that the approach direction to the next point was always the same.The earliest examples of these cheaper point-to-point machines usually did not use recalculating ball screws; this meant that the motions would be sluggish, and sliderways would inevitably suffer from backlash, but more will be said about this topic later in the chapter.The early NC machines were, in the main, based upon a modified milling machine with this concept of control being utilized on turning, punching, grinding and a whole host of other machine tools later. Towards the end of the 1950s,hydrostatic slideways were often incorporated for machine tools of highly precision, which to sonic extent overcame the section problem associated with conventional slideway response, whiles averaging-out slideway inaccuracy brought about a much increased preasion in the machine tool and improved their control characteristics allows "concept of the machining center" was the product of this early work, as it allowed the machine to manufacture a range of components using a wide variety of machining processes at a single set-up, without transfer of workpieces to other variety machine tools. A machining center differed conceptually in its design from that of a milling machine, In that thecutting tools could be changed automatically by the transfer machanism, or selector, from the magazine to spindle, or vice versa.In this ductively and the automatic tool changing feature enabled the machining center to productively and efficiently machine a range of components, by replacing old tools for new, or reselecting the next cutter whilst the current machining process is in cycle.In the mid 1960s,a UK company, Molins, introduced their unique "System 24" which was meant represent the ability of a system to machine for 24 hours per day. It could be thought of as a "machining complex" which allowed a series of NC single purpose machine tools to be linked by a computerized conveyor system. This conveyor allowed the work pieces to be palletized and then directed to as machine tool as necessary. This was an early, but admirable, attempt at a form of Flexible manufacturing System concept, but was unfortunately doomed to failure. Its principal weakness was that only a small proportion of component varieties could be machine at any instant and that even fewer work pieces required the same operations to be performed on them. These factors meant that the utilization level was low, coupled to the fact that the machine tools were expensive and allowed frequent production bottlenecks of work-in-progress to arise, which further slowed down the whole operation.The early to mid-1970s was a time of revolutionary in the area of machine tool controller development, when the term computerized numerical control (CNC) became a reality. This new breed of controllers gave a company the ability to change work piece geometries, together with programs, easily with the minimum of development and lead time, allowing it to be economically viable to machine small batches, or even one-off successfully. The dream of allowing a computerized numerical controller the flexibility and ease of program editing in a production environment became a reality when two ralated factors occurred.These were:the development of integrated circuits, which reduces electronics circuit size, giving better maintenance and allowing more standardization of desing; that general purpose computers were reduced in size coupled to the fact that their cost of production had fallen considerably.The multipie benefits of cheaper electorics with greater reliability have result in the CNC fitted to the machine tools today, with the power and sophistication progtessing considerably in the last few years, allowing an almost artificial intelligence(AI) to the latest systems. Over the years, the machine tools builders have produced a large diversity in the range of applications of CNC and just some of those development will be reviewed in V olume Ⅲ。
机械设计外文文献翻译、中英文翻译
机械设计外文文献翻译、中英文翻译unavailable。
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the designer must define the problem and XXX。
ideas and concepts are generated。
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and refined until the best one is XXX。
XXX.XXX。
assembly。
XXX.During the preliminary design stage。
it is important to allow design XXX if some ideas may seem impractical。
they can be corrected early on in the design process。
机械设计外文翻译--机器人
Robotthe industrial robot is a tool that is used in the manufacturing environment to increase productivity.It can perform jobs that mights be hazardous to the human worker.One of the first industrial robots was used to replace the nuclear power plants.The industrial robot can also operate on the assembly line such as placing electronic components on a printed circuit board .Thus ,the human worker can be relieved of the routine operation of this tedious task .Robots can also be programmed to defuse bombs,to serve the handicapped ,and to perform functions in numerous applications in our society.A robot is a reprogrammable,multifunctional manipulator designed to more parts,materials tools or special devices through variable pregrammed locations for the performance of a variety of different tasks.Preprogrammed locations are paths that the robot must follow to accomplish work.At some of these locations ,the robot will stop and perform some operation,such as assembly of parts,spray painting,or welding.These ppreprogrammed locations are stored in the robot’s memory and are recalled later for continous operation.Furthermore,these preprogrammed locations,as well as other program data,can be changed later as the work requirements change .Thus ,with regard to this programming feature,an industrial robot is very much like a computer.The robotic system can also control the work cell of the operating robot.The work cell of the robot is the total enviroment in which the robot must perform its task.Included within this cell may be the robot manipulator,controller,a work table ,safety features,or a conveyor.In addition, signals from outside device can communicate with the robot.The manipulator,which does the physical work of the robotic system,consists of two sections:the mechanical section and the attached appendage.The manipulator also has a base to which the appendages are attached.The base of the manipulator is usually fixed to the floor of the work area.Sometimes,through,the base may be movable.In this case,the base is attached to either a rail or a track,allowing the manipulator to be moved from one location to another.the manipulator is mainly composed of the hand and the motion. The hand is uses for to grasp holds the work piece (or tool) the part, according to is grasped holds the thing shape, the size, the weight, the material and the work request has many kinds of structural styles, like the clamp, therequest hold and the adsorption and so on. The motion, causes the hand to complete each kind of rotation (swinging), the migration or the compound motion realizes the stipulation movement, changes is grasped holds the thing position and the posture. Motion's fluctuation, the expansion, revolving and so on independence movement way, is called manipulator's degree-of-freedom. In order to capture in the space the optional position and the position object, must have 6 degrees-of-freedom. The degree-of-freedom is the key parameter which the manipulator designs. The degree-of-freedom are more, manipulator's flexibility is bigger, the versatility is broader, its structure is also more complex. Generally the special-purpose manipulator has 2~3 degrees-of-freedom.The appendage is the arm of the robot.It can be either a straight,movable arm or a jointed arm and gives the manipulator its various axes of motion.The jointed arm is also known as an articulated arm.At the end of the arm,a wrist is connected.The wrist is made up of additional axes and a wrist flange.The wrist flange allows therobot user to connectdifferent tooling to the wrist for different jobs.The manipulator’saxes allow it to perform work within acertain area.This area is called the work cell of the robot,and its size corresponds to the size of the manipulator.As the robot’physical size increases,the size of the work cell must also increase.The movement of the manipulator is controlled by actuators, or drive system can use electric,hydraulic,or pneumatic power.The energy developed by the drive system is convered to mechanical power by various mechanical drive systems.The drive systems are coupled through mechanical linkages.These linkages,in turn,drive the different axes of the robot. The mechanical linkages may be composed of chains,geas,and ball screws.The controller is used to control the robot manipulator’movements as well as to control peripheral components within the work cell.The user can program themovements of the manipulator into the controller through the use of a hand-held teach pendant.This information is stored in the memory of the controller for later recall.The controller is also required to communicate with peripheral equipment within the work cell.For example,a controller has an input line.When the machine cycle is completed,the input line turns on ,telling the controller to position the manipulator so that it can pick up the finished part.Then ,a new part is picked up by the manipulator and placed into the machine.Next,the controller signals the machine to start operation.The controller can be made from mechanically operated drums that step through a sequence of events.This type of controller operates with simple robotic system.The controllers found on the majority of robotic systems are more complex devices and represent state-of-the-art electronics.That is,they are microprocessor-operated.This power allows the controller to be very flexible in its operation.The controller can send electric signals over communication lines.This two- way communication between the robot manipulator and the controller maintains a constant update of the location and the operation of the system.The controller also has the job of communicating with the different plant computer.The communication link establishes the robot as part of a computer-assisted manufacturing(CAM)system.The microprocessor-based systems operate in conjunction with solid-state memory devices.These memory devices may be magnetic bubbles,random-access memory,floppy disk,or magnetic tape.The power supply is the unit that supplies power to the controller and the manipulator.Two types of power are delived to the robotic system.One type of power is the Acpower for operation of the controller.The other type of power is used for driving the various axes of the manipulator.For example,if the robot manipulator is controlled by hydraulic or pneumatic drives,control signals are sent to these devices,causing motion of the robot.Industrial robots vary widely in size ，shape，number of axes，degrees of freedom，and design configuration .Each factor influences the dimensions of the robot’s working envelop or the volume of space within which it can move and perform its designated task.A broader classification of robots can been described as below.Fixed-and Variable-Sequence Robots .The fixed-sequence robot(also called a pick-and place robot)is programmed for a specific sequence of operqtions.Its movements are from point to point ,and the cycle is repeated continuously.The variable-sequence robot can be programmed for a specific sequence of operations but can be reprogrammed to perform another sequence of operation.Playback Robot.An operator leads or walks the playback robot and its end effector through the deired path .The robot memorizes and records the path and sequence of motions and can repeat them continually without any further action or guidance by the operator.Numerically Controlled Robot.The numerically cantrolled robot is programmed and operatedmuch like a numerically controlled machine .The robot is servocontrolled by digital data ,and its sequence of movements can be changed with relative ease.Intelligent Robot.[3]The intelligent robot is capable of performing some of the functions and tasks carried out by human beings .It is equipped with a variety of sensors with visual and tactile capabilities.机器人工业机器人是一种提高制造业生产力的工具，它可以承担那些对人类可能有危险的工作。
机械工程外文翻译
外文资料原文及译文学院：机电工程学院专业：机械设计制造及其自动化班级：学号：姓名：Mechanical engineering1.The porfile of mechanical engineeringEngingeering is a branch of mechanical engineerig,itstudies mechanical and power generation especially power and movement.2.The history of mechanical engineering18th century later periods,the steam engine invention hasprovided a main power fountainhead for the industrialrevolution,enormously impelled each kind of mechznicalbiting.Thus,an important branch of a new Engineering –separated from the civil engineering tools and machines on thebranch-developed together with Birmingham and the establishment of the Associantion of Mechanical Engineers in1847 had been officially recognized.The mechanicalengineering already mainly used in by trial and error methodmechanic application technological development intoprofessional engineer the scientific method of which in theresearch,the design and the realm of production used .From themost broad perspective,the demend continuously to enhance theefficiencey of mechanical engineers improve the quality of work,and asked him to accept the history of the high degreeof education and training.Machine operation to stress not onlyeconomic but also infrastructure costs to an absolute minimun.3.The field of mechanical engineeringThe commodity machinery development in the develop country,in the high level material life very great degree is decided each kind of which can realize in the mechanical engineering.Mechanical engineers unceasingly will invent the machine next life to produce the commodity,unceasingly will develop the accuracy and the complexity more and more high machine tools produces the machine.The main clues of the mechanical development is:In order to enhance the excellent in quality and reasonable in price produce to increase the precision as well as to reduce the production cost.This three requirements promoted the complex control system development.The most successful machine manufacture is its machine and the control system close fusion,whether such control system is essentially mechanical or electronic.The modernized car engin production transmission line(conveyer belt)is a series of complex productions craft mechanization very good example.The people are in the process of development in order to enable further automation of the production machinery ,the use of a computer to store and handle large volumes of data,the data is a multifunctional machine toolsnecessary for the production of spare parts.One of the objectives is to fully automated production workshop,three rotation,but only one officer per day to operate.The development of production for mechanical machinery must have adequate power supply.Steam engine first provided the heat to generate power using practical methods in the old human,wind and hydropower,an increase of engin .New mechanical engineering industry is one of the challenges faced by the initial increase thermal effciency and power,which is as big steam turbine and the development of joint steam boilers basically achieved.20th century,turbine generators to provide impetus has been sustained and rapid growth,while thermal efficiency is steady growth,and large power plants per kW capital consumption is also declining.Finally,mechanical engineers have nuclear energy.This requires the application of nuclear energy particularly high reliability and security, which requires solving many new rge power plants and the nuclear power plant control systems have become highly complex electroonics,fluid,electricity,water and mechanical parts networks All in all areas related to the mechanical engineers.Small internal combustion engine,both to the type (petrol and diesel machines)or rotary-type(gas turbines andMong Kerr machine),as well as their broad application in the field of transport should also due to mechanical enginerrs.Throughout the transport,both in the air and space,or in the terrestrial and marine,mechanial engineers created a variety of equipment and power devices to their increasing cooperation with electrical engineers,especially in the development of appropration control systems.Mechanical engineers in the development of military weapons technology and civil war ,needs a similar,though its purpose is to enhance rather than destroy their productivity.However.War needs a lot of resources to make the area of techonlogy,many have a far-reaching development in peacetime efficiency.Jet aircraft and nuclear reactors are well known examples.The Biological engineering,mechanical engineering biotechnology is a relatively new and different areas,it provides for the replacement of the machine or increase the body functions as well as for medical equipment.Artficial limbs have been developed and have such a strong movement and touch response function of the human body.In the development of artificial organ transplant is rapid,complex cardiac machines and similar equipment to enable increasingly complex surgery,and injuries and ill patients life functions can besustained.Some enviromental control mechanical engineers through the initial efforts to drainage or irrigation pumping to the land and to mine and ventilation to control the human environment.Modern refrigeration and air-conditioning plant commonaly used reverse heat engine,where the heat from the engine from cold places to more external heat.Many mechanical engineering products,as well as other leading technology development city have side effects on the environment,producing noise,water and air pollution caused,destroyed land and landscape.Improve productivity and diver too fast in the commodity,that the renewable natural forces keep pace.For mechanical engineers and others,environmental control is rapidly developing area,which includes a possible development and production of small quantities of pollutants machine sequnce,and the development of new equipment and teachnology has been to reduce and eliminate pollution.4.The role of mechanical engineeringThere are four generic mechanical engineers in common to the above all domains function.The 1st function is the understanding and the research mechanical science foundation.It includes the power and movement of therelationship dynamics For example,in the vibration and movement of the relationship;Automatic control;Study of the various forms of heart,energy,power relations between the thermodynamic;Fluidflows; Heat transfer; Lubricant;And material properties.The 2nd function will be conducts the research,the desing and the development,this function in turn attempts to carry on the essential change to satisfy current and the future needs.This not only calls for a clear understanding of mechanical science,and have to break down into basic elements of a complex system capacity.But also the need for synthetic and innovative inventions.The 3rd function is produces the product and the power,include plan,operation and maintenance.Its goal lies in the maintenance either enhances the enterprise or the organization longer-tern and survivabilaty prestige at the same time,produces the greatest value by the least investments and the consumption.The 4th function is mechanical engineer’s coordinated function,including the management,the consultation,as well as carries on the market marking in certain situation.In all these function,one kind unceasingly to use the science for a long time the method,but is not traditional orthe intuition method tendency,this is a mechanical engineering skill aspect which unceasingly grows.These new rationalization means typical names include:The operations research,the engineering economics,the logical law problem analysis(is called PABLA) However,creativity is not rationalization.As in other areas,in mechanical engineering, to take unexpected and important way to bring about a new capacity,still has a personal,marked characteristice.5.The design of mechanical engineeringThe design of mechanical is the design has the mechanical property the thing or the system,such as:the instrument and the measuring appliance in very many situations,the machine design must use the knowledge of discipline the and so on mathematics,materials science and mechanics.Mechanical engineering desgin includeing all mechanical desgin,but it was a study,because it also includes all the branches of mechsnical engineering,such as thermodynamics all hydrodynamics in the basic disciplines needed,in the mechanical engineering design of the initial stude or mechanical design.Design stages.The entire desgin process from start to finish,in the process,a demand that is designed for it and decided to do the start.After a lot of repetition,thefinal meet this demand by the end of the design procees and the plan.Design considerations.Sometimes in a system is to decide which parts needs intensity parts of geometric shapes and size an important factor in this context that we must consider that the intensity is an important factor in the design.When we use expression design considerations,we design parts that may affect the entire system design features.In the circumstances specified in the design,usually for a series of such functions must be taken into account.Howeever,to correct purposes,we should recognize that,in many cases the design of important design considerations are not calculated or test can determine the components or systems.Especially students,wheen in need to make important decisions in the design and conduct of any operation that can not be the case,they are often confused.These are not special,they occur every day,imagine,for example,a medical laboratory in the mechanical design,from marketing perspective,people have high expectations from the strength and relevance of impression.Thick,and heavy parts installed together:to produce a solid impression machines.And sometimes machinery and spare parts from the design style is the point and not the other point of view.Our purpose is to make those you do notbe misled to believe that every design decision will need reasonable mathematical methods.Manufacturing refers to the raw meterials into finished products in the enterprise.Create three distinct phases.They are:input,processing exprot.The first phase includes the production of all products in line with market needs essential.First there must be the demand for the product,the necessary materials,while also needs such as energy,time,human knowledge and technology resourcess . Finall,the need for funds to obtain all the other resources. Lose one stage after the second phase of the resources of the processes to be distributed.Processing of raw materials into finished products of these processes.To complete the design,based on the design,and then develop plans.Plan implemented through various production processes.Management of resources and processes to ensure efficiency and productivity.For example,we must carefully manage resources to ensure proper use of funds.Finally,people are talking about the product market was cast.Stage is the final stage of exporting finished or stage.Once finished just purchased,it must be delivered to the users.According to product performance,installation and may have to conduct furtherdebugging in addition,some products,especially those very complex products User training is necessary.6.The processes of materials and maunfacturingHere said engineering materials into two main categories:metals and non-ferrous,high-performance alloys and power metals.Non-metallic futher divided into plastice,synthetic rubber,composite materials and ceramics.It said the production proccess is divided into several major process,includingshape,forging,casting/ founding,heat treatment,fixed/connections ,measurement/ quality control and materal cutting.These processes can be further divide into each other’s craft.Various stages of the development of the manufacturing industry Over the years,the manufacturing process has four distinct stages of development, despite the overlap.These stages are:The first phase is artisanal,the second Phase is mechanization.The third phase is automation the forth Phase is integrated.When mankind initial processing of raw materials into finished products will be,they use manual processes.Each with their hands and what are the tools manuslly produced.This is totally integrated production take shape.A person needs indentification,collection materials,the design of a productto meet that demand,the production of such products and use it.From beginning to end,everything is focused on doing the work of the human ter in the industrial revolution introduced mechanized production process,people began to use machines to complete the work accomplished previously manual. This led to the specialization.Specialization in turn reduce the manufacture of integrated factors.In this stage of development,manufacturing workers can see their production as a whole represent a specific piece of the part of the production process.One can not say that their work is how to cope with the entire production process,or how they were loaded onto a production of parts finished.Development of manufacting processes is the next phase of the selection process automation.This is a computer-controlled machinery and processes.At this stage,automation island began to emerge in the workshop lane.Each island represents a clear production process or a group of processes.Although these automated isolated island within the island did raise the productivity of indivdual processes,but the overall productivity are often not change.This is because the island is not caught in other automated production process middle,but not synchronous with them .The ultimate result is the efficient working fast parkedthrough automated processes,but is part of the stagnation in wages down,causing bottlenecks.To better understand this problem,you can imagine the traffic in the peak driving a red light from the red Service Department to the next scene. Occasionally you will find a lot less cars,more than being slow-moving vehicles,but the results can be found by the next red light Brance.In short you real effect was to accelerate the speed of a red Department obstruction offset.If you and other drivers can change your speed and red light simultaneously.Will advance faster.Then,all cars will be consistent,sommth operation,the final everyone forward faster.In the workshop where the demand for stable synchronization of streamlined production,and promoted integration of manufacturing development.This is a still evolving technology.Fully integrated in the circumstances,is a computer-controllrd machinery and processing.integrated is completed through computer.For example in the preceding paragraph simulation problems,the computer will allow all road vehicles compatible with the change in red.So that everyone can steady traffic.Scientific analysis of movement,timing and mechanics of the disciplines is that it is composed of two pater:staticsand dynamics.Statics analyzed static system that is in the system,the time is not taken into account,research and analysis over time and dynamics of the system change.Dynameics from the two componets.Euler in 1775 will be the first time two different branches: Rigid body movement studies can conveniently divided into two parts:geometric and mechanics.The first part is without taking into account the reasons for the downward movement study rigid body from a designated location to another point of the movement,and must use the formula to reflect the actual,the formula would determine the rigid body every point position. Therefore,this study only on the geometry and,more specifically,on the entities from excision.Obviously,the first part of the school and was part of a mechanical separation from the principles of dynamics to study movement,which is more than the two parts together into a lot easier.Dynamics of the two parts are subsequently divided into two separate disciplines,kinematic and dynamics,a study of movement and the movement strength.Therefore,the primary issue is the design of mechanical systems understand its kinematic.Kinematic studies movement,rather than a study of its impact.In a more precise kinematic studies position,displacement,rotation,speed,velocity and acceleration of disciplines,for esample,or planets orbiting research campaing is a paradigm.In the above quotation content should be pay attention that the content of the Euler dynamics into kinematic and rigid body dynamics is based on the assumption that they are based on research.In this very important basis to allow for the treatment of two separate disciplines.For soft body,soft body shape and even their own soft objects in the campaign depends on the role of power in their possession.In such cases,should also study the power and movement,and therefore to a large extent the analysis of the increased complexity.Fortunately, despite the real machine parts may be involved are more or less the design of machines,usually with heavy material designed to bend down to the lowest parts.Therefore,when the kinematic analysis of the performance of machines,it is often assumed that bend is negligible,spare parts are hard,but when the load is known,in the end analysis engine,re-engineering parts to confirm this assnmption.机械工程1.机械工程简介机械工程是工程学的一个分支，它研究机械和动力的产，尤其是力和动力。
机械专业毕业设计外文翻译1
本科毕业设计（本科毕业论文）外文文献及译文文献、资料题目：High-rise Tower Crane designed文献、资料来源：期刊（著作、网络等）文献、资料发表（出版）日期：2000.3.25院（部）：机电工程学院专业：机电工程及自动化High-rise Tower Crane designed under Turbulent Winds At present, construction of tower cranes is an important transport operations lifting equipment, tower crane accident the people's livelihood, major hazards, and is currently a large number of tower crane drivers although there are job permits, due to the lack of means to monitor and review the actual work of a serious violation . Strengthen the inspection and assessment is very important. Tower crane tipping the cause of the accident can be divided into two aspects: on the one hand, as a result of the management of tower cranes in place, illegal operation, illegal overloading inclined cable-stayed suspended widespread phenomenon; Second, because of the tower crane safety can not be found in time For example,Took place in the tower crane foundation tilt, micro-cracks appear critical weld, bolts loosening the case of failure to make timely inspection, maintenance, resulting in the continued use of tower cranes in the process of further deterioration of the potential defect, eventually leading to the tower crane tipping. The current limit of tower crane and the black box and can not be found to connect slewing tower and high-strength bolts loosening tightened after the phenomenon is not timely, not tower verticality of the axis line of the lateral-line real-time measurement, do not have to fight the anti-rotation vehicles, lifting bodies plummeted Meng Fang, hook hoists inclined cable is a timely reminder and record of the function, the wind can not be contained in the state of suspended operation to prevent tipping on the necessary tips on site there is a general phenomenon of the overloaded overturning of the whole security risks can not be accurately given a reminder and so on, all of which the lease on the tower crane, use, management problems,Through the use of tower crane anti-tipping monitor to be resolved. Tower crane anti-tipping Monitor is a new high-tech security monitoring equipment, and its principle for the use of machine vision technology and image processing technology to achieve the measurement of the tilt tower, tower crane on the work of state or non-working state of a variety of reasons angle of the tower caused by the critical state to achieve the alarm, prompt drivers to stop illegal operation, a computer chip at the same time on the work of the state of tower crane be recorded. Tower crane at least 1 day overload condition occurs, a maximum number of days to reach 23 overloading, the driver to operate the process of playing the anti-car, stop hanging urgency, such as cable-stayed suspended oblique phenomenon often, after verification and education, to avoid the possible occurrence of fatal accidents. Wind conditions in the anti-tipping is particularly important, tower cranes sometimes connected with the pin hole and pin do not meet design requirements, to connect high-strength bolts are not loose in time after the tightening of the phenomenon, through timely maintenance in time after the tightening of the phenomenon, through timely maintenance and remedial measures to ensure that the safe and reliable construction progress. Reduced lateral line tower vertical axis measuring the number of degrees,Observation tower angle driver to go to work and organize the data once a month to ensure that the lateral body axis vertical line to meet the requirements, do not have to every time and professionals must be completed by Theodolite tower vertical axismeasuring the lateral line, simplified the management link. Data logging function to ensure that responsibility for the accident that the scientific nature to improve the management of data records for the tower crane tower crane life prediction and diagnosis of steel structures intact state data provides a basis for scientific management and proactive prevention of possible accidents, the most important thing is, if the joint use of the black box can be easily and realistically meet the current provisions of the country's related industries. Tower crane safety management at the scene of great importance occurred in the construction process should be to repair damaged steel, usually have to do a good job in the steel tower crane maintenance work and found that damage to steel structures, we must rule out potential causes of accidents, to ensure safety in production carried out smoothly. Tower crane in the building construction has become essential to the construction of mechanical equipment, tower crane at the construction site in the management of safety in production is extremely important. A long time, people in the maintenance of tower crane, only to drive attention to the conservation and electrical equipment at the expense of inspection and repair of steel structures, to bring all kinds of construction accidents.Conclusion: The tower crane anti-tipping trial monitor to eliminate potential causes of accidents to provide accurate and timely information, the tower crane to ensure the smooth development of the leasing business, the decision is correct, and should further strengthen and standardize the use of the environment (including new staff training and development of data processing system, etc.).The first construction cranes were probably invented by the Ancient Greeks and were powered by men or beasts of burden, such as donkeys. These cranes were used for the construction of tall buildings. Larger cranes were later developed, employing the use of human treadwheels, permitting the lifting of heavier weights. In the High Middle Ages, harbour cranes were introduced to load and unload ships and assist with their construction – some were built into stone towers for extra strength and stability. The earliest cranes were constructed from wood, but cast iron and steel took over with the coming of the Industrial Revolution.For many centuries, power was supplied by the physical exertion of men or animals, although hoists in watermills and windmills could be driven by the harnessed natural power. The first 'mechanical' power was provided by steam engines, the earliest steam crane being introduced in the 18th or 19th century, with many remaining in use well into the late 20th century. Modern cranes usually use internal combustion engines or electric motors and hydraulic systems to provide a much greater lifting capability than was previously possible, although manual cranes are still utilised where the provision of power would be uneconomic.Cranes exist in an enormous variety of forms – each tailored to a specific use. Sizes range from the smallest jib cranes, used inside workshops, to the tallest tower cranes,used for constructing high buildings, and the largest floating cranes, used to build oil rigs and salvage sunken ships.This article also covers lifting machines that do not strictly fit the above definition of a crane, but are generally known as cranes, such as stacker cranes and loader cranes.The crane for lifting heavy loads was invented by the Ancient Greeks in the late 6th century BC. The archaeological record shows that no later than c.515 BC distinctive cuttings for both lifting tongs and lewis irons begin to appear on stone blocks of Greek temples. Since these holes point at the use of a lifting device, and since they are to be found either above the center of gravity of the block, or in pairs equidistant from a point over the center of gravity, they are regarded by archaeologists as the positive evidence required for the existence of the crane.The introduction of the winch and pulley hoist soon lead to a widespread replacement of ramps as the main means of vertical motion. For the next two hundred years, Greek building sites witnessed a sharp drop in the weights handled, as the new lifting technique made the use of several smaller stones more practical than of fewer larger ones. In contrast to the archaic period with its tendency to ever-increasing block sizes, Greek temples of the classical age like the Parthenon invariably featured stone blocks weighing less than 15-20 tons. Also, the practice of erecting large monolithic columns was practically abandoned in favour of using several column drums.Although the exact circumstances of the shift from the ramp to the crane technology remain unclear, it has been argued that the volatile social and political conditions of Greece were more suitable to the employment of small, professional construction teams than of large bodies of unskilled labour, making the crane more preferable to the Greek polis than the more labour-intensive ramp which had been the norm in the autocratic societies of Egypt or Assyria.The first unequivocal literary evidence for the existence of the compound pulley system appears in the Mechanical Problems (Mech. 18, 853a32-853b13) attributed to Aristotle (384-322 BC), but perhaps composed at a slightly later date. Around the same time, block sizes at Greek temples began to match their archaic predecessors again, indicating that the more sophisticated compound pulley must have found its way to Greek construction sites by then.During the High Middle Ages, the treadwheel crane was reintroduced on a large scale after the technology had fallen into disuse in western Europe with the demise of the Western Roman Empire. The earliest reference to a treadwheel (magna rota) reappears in archival literature in France about 1225, followed by an illuminated depiction in a manuscript of probably also French origin dating to 1240. In navigation, the earliest uses of harbor cranes are documented for Utrecht in 1244, Antwerp in 1263, Brugge in 1288 and Hamburg in 1291, while in England the treadwheel is not recorded before 1331.Generally, vertical transport could be done more safely and inexpensively by cranes than by customary methods. Typical areas of application were harbors, mines, and, in particular, building sites where the treadwheel crane played a pivotal role in the construction of the lofty Gothic cathedrals. Nevertheless, both archival and pictorial sources of the time suggest that newly introduced machines like treadwheels or wheelbarrows did not completely replace more labor-intensive methods like ladders, hods and handbarrows. Rather, old and new machinery continued to coexist on medieval construction sites and harbors.Apart from treadwheels, medieval depictions also show cranes to be powered manually by windlasses with radiating spokes, cranks and by the 15th century also by windlasses shaped like a ship's wheel. To smooth out irregularities of impulse and get over 'dead-spots' in the lifting process flywheels are known to be in use as early as 1123.The exact process by which the treadwheel crane was reintroduced is not recorded, although its return to construction sites has undoubtedly to be viewed in close connection with the simultaneous rise of Gothic architecture. The reappearance of the treadwheel crane may have resulted from a technological development of the windlass from which the treadwheel structurally and mechanically evolved. Alternatively, the medieval treadwheel may represent a deliberate reinvention of its Roman counterpart drawn from Vitruvius' De architectura which was available in many monastic libraries. Its reintroduction may have been inspired, as well, by the observation of the labor-saving qualities of the waterwheel with which early treadwheels shared many structural similarities.In contrast to modern cranes, medieval cranes and hoists - much like their counterparts in Greece and Rome - were primarily capable of a vertical lift, and not used to move loads for a considerable distance horizontally as well. Accordingly, lifting work was organized at the workplace in a different way than today. In building construction, for example, it is assumed that the crane lifted the stone blocks either from the bottom directly into place, or from a place opposite the centre of the wall from where it could deliver the blocks for two teams working at each end of the wall. Additionally, the crane master who usually gave orders at the treadwheel workers from outside the crane was able to manipulate the movement laterally by a small rope attached to the load. Slewing cranes which allowed a rotation of the load and were thus particularly suited for dockside work appeared as early as 1340. While ashlar blocks were directly lifted by sling, lewis or devil's clamp (German Teufelskralle), other objects were placed before in containers like pallets, baskets, wooden boxes or barrels.It is noteworthy that medieval cranes rarely featured ratchets or brakes to forestall the load from running backward.[25] This curious absence is explained by the high friction force exercised by medieval treadwheels which normally prevented the wheel from accelerating beyond control.目前，塔式起重机是建筑工程进行起重运输作业的重要设备，塔机事故关系国计民生、危害重大，而目前众多的塔机司机虽然有上岗证，由于缺少监督和复核手段，实际工作中违规严重。
机械专业毕业设计外文翻译--机械传动系统介绍
Transmission System introducedThe important position of the wheel gear and shaft can’t falter in traditional machine and modern machines. The wheel gear and shafts mainly install the direction that delivers the dint at the principal axis box. The passing to process to make them can is divided into many model numbers, used for many situations respectively. so we must be the multilayers to the understanding of the wheel gear and shaft in many ways.In the force analysis of spur gears, the forces are assumed to act in a single plane. We shall study gears in which the forces have three dimensions. The reason for this, in the case of helical gears, is that the teeth are not parallel to the axis of rotation. And in the case of bevel gears, the rotational axes are not parallel to each other. There are also other reasons, as we shall learn.Helical gears are used to transmit motion between parallel shafts. The helix angle is the same on each gear, but one gear must have a right-hand helix and the other a left-hand helix. The shape of the tooth is an involute helicoid. If a piece of paper cut in the shape of a parallelogram is wrapped around a cylinder, the angular edge of the paper becomes a helix. If we unwind this paper, each point on the angular edge generates an involute curve. The surface obtained when every point on the edge generates an involute is called an involute helicoids.The initial contact of spur-gear teeth is a line extending all the way across the face of the tooth. The initial contact of helical gear teeth is a point, which changes into a line as line as the teeth come into more engagement. In spur gears the line of contact is parallel to the axis of the rotation; in helical gears, the line is diagonal across the face of the tooth. It is this gradual of the teeth and the smooth transfer of load from one tooth to another, which give helical gears the ability to transmit heavy loads at high speeds. Helical gears subject the shaft bearings to both radial and thrust loads. When the thrust loads become high or are objectionable for other reasons, it may be desirable to use double helical gears. A double helical gear (herringbone) is equivalent to two helical gears of opposite hand, mounted side by side on the same shaft. They develop opposite thrust reactions and thus cancel out the thrust load. When two or more single helical gears are mounted on the same shaft, the hand of the gears should be selected so as to produce the minimum thrust load.Crossed-helical, or spiral, gears are those in which the shaft centerlines are neither parallel nor interesting. The teeth of crossed-helical fears have point contact with each other which changes to line contact as the gears wear in. for this reason they will carry out very small loads and are mainly for instrumental applications, and are definitely not recommended for use in the transmission of power. There is on difference between a crossed helical gear and a helical gear until they are mounted in mesh with each other. They are manufactured in the same way. A pair of meshed crossed helical gears usually have the same hand; that is, a right-hand driver goes with a right-hand driven. In the design of crossed-helical gears, the minimum sliding velocity is obtained when the helix angle are equal. However, when the helix angle are not equal, the gear with the larger helix angle should be used as the driver if both gears have the same hand.Worm gears are similar to crossed helical gears. The pinion or worm has a small number of teeth, usually one to four, and since they completely wrap around the pitch cylinder they are called threads. Its mating gear is called a worm gear, which is not a true helical gear. A worm and worm gear are used to provide a high angular-velocity reduction between nonintersecting shafts which are usually at right angle. The worm gear is not a helical gear because its face is made concave to fit the curvature of the worm in order to provide line contact instead of point contact. However, a disadvantage of worm gearing is the high sliding velocities across the teeth, the same as with crossed helical gears.Worm gearing are either single or double enveloping. A single-enveloping gearing is one in which the gear wraps around or partially encloses the worm. A gearing in which each element partially encloses the other is, of course, a double-enveloping worm gearing. The important difference between the two is that area contact exists between the teeth of double-enveloping gears while only line contact between those of single-enveloping gears. The worm and worm gear of a set have the same hand of helix as for crossed helical gears, but the helix angles are usually quite different. The helix angle on the worm is generally quite large, and that on the gear very small. Because of this, it is usual to specify the lead angle on the worm, which is the complement of the worm helix angle, and the helix angle on the gear; the two angles ate equal for a 90-deg. Shaft angle.When gears are to be used to transmit motion between intersecting shaft, some ofbevel gear is required. Although bevel gear are usually made for a shaft angle of 90 deg. They may be produced for almost any shaft angle. The teeth may be cast, milled, or generated. Only the generated teeth may be classed as accurate. In a typical bevel gear mounting, one of the gear is often mounted outboard of the bearing this means that shaft deflection can be more pronounced and have a greater effect in the contact of teeth. Another difficulty, which occurs in predicting the stress in bevel-gear teeth, is the fact the teeth are tapered.Straight bevel gears are easy to design and simple to manufacture and give very good results in service if they are mounted accurately and positively. As in the case of squrgears, however, they become noisy at higher values of the pitch-line velocity. In these cases it is often good design practice to go to the spiral bevel gear, which is the bevel counterpart of the helical gear. As in the case of helical gears, spiral bevel gears give a much smoother tooth action than straight bevel gears, and hence are useful where high speed are encountered.It is frequently desirable, as in the case of automotive differential applications, to have gearing similar to bevel gears but with the shaft offset Such gears are called hypoid gears because their pitch surfaces are hyperboloids of revolution The tooth action between such gears is a combination of rolling and has much in common with that of worm gears.A shaft is a rotating or stationary member usually of circular cross section, having mounted upon it such elementsas gears pulleys flywheels, cranks sprockets and other power-transmission elements Shaft may be subjected to bending tension compression or torsional loads acting singly or in combination with one another .When they are combined one may expect to find both static and fatigue strength to be important design considerations since a single shaft may be subjected to static stresses completely reversed, and repeated stresses, all acting at the same timeThe word “shaft” covers numerous wariations, such as axles and spindles. Anaxle is a shaft, wither stationary or rotating nor subjected to torsion load. Ashirt rotating shaft is often called a spindle.When either the lateral or the tosional deflection of shaft must be held to close limits, the shaft must be sized on the basis of deflection before analyzing the stresses The reasonfor this is that if the shift is made stiff enough so that the deflection is not too large, it is probable that the resulting stresses will be safe. But by no means should the designer assume that they are within acceptable limits. Whenever possible the power-transmission elements such as gears or pullets, should be located close to the supporting bearings. This reduces the bending moment, and hence the deflection and bending stress.Although the von Mises-Hencky-Goodman method is difficult to use in design of shaft, it probably come closest to predicting actual failure. Thus it is a good way of checking a shaft that has already been designed or of discovering why a particular shaft that has already been designed or of discovering why a particular shaft has failed in service. Furthermore, there are a considerable number of shaft-design problems in which the dimension are pretty well limited by other considerations, such as rigidity, and it is only necessary for the designer to discover something about the fillet sizes, heat-treatment, and surface finish and whether or not shot peening is necessary in order to achieve the required life and reliability.Because of the similarity of their functions, clutches and brakes are treated together. In a simplified dynamic representation of a friction clutch, or brake, two inertias I1and I2 traveling at the respective angular velocities W1 and W2, one of which may be zero in the case of brake, are to be brought to the same speed by engaging the clutch or brake. Slippage occurs because the two elements are running at different speeds and energy is dissipated during actuation, resulting in a temperature rise. In analyzing the performance of these devices we shall be interested in the actuating force, the torque transmitted, the energy loss and the temperature rise. The torque transmitted is related to the actuating force, the coefficient of friction, and the geometry of the clutch or brake. This is problem in static, which will have to be studied separately for each geometric configuration. However, temperature rise is related to energy loss and can be studied without regard to the type of brake or clutch because the geometry of interest is the hear-dissipating surfaces. The various types of clutches and brakes may be classified as fallows:Rim type with internally expanding shoesRim type with internally contracting shoesBand typeDisk or axial typeCone typeMiscellaneous typeThe analysis of all type of friction clutches and brakes use the same general procedure. The following step are necessary:1. Assume or determine the distribution of pressure on the frictionalsurfaces.2. Find a relation between the maximum pressure and the pressure at any point3. apply the condition of statical equilibrium to find (a) the actuating force, (b) the torque, and (c) the support reactions.Miscellaneous clutches include several type, such as the positive-contact clutches, overload-release clutches, overrunning clutches, magnetic fluid clutches, and others.A positive-contact clutch consists of a shift lever and two jaws. The greatest differences between the various types of positive clutches are concerned with the design of the jaws. To provide a longer period of time for shift action during engagement, the jaws may be ratchet-shaped, or gear-tooth-shaped. Sometimes a great many teeth or jaws re used, and they may be cut either circumferentially, so that they engage by cylindrical mating, or on the faces of the mating elements.Although positive clutches are not used to the extent the frictional-contact type, they do have important applications where synchronous operation is required.Devices such as linear driver or motor-operated screw drivers must run to definite limit and then come to a stop. An over load-release rype of clutch is required for these applications. These clutches are usually spring-loaded so as to release at a predetermined toque. The clicking sound which is heard when the overload point is reached is considered to be a desirable signal.An overrunning clutch or coupling permits the driven member of a machine to “freewheel” or “overrun” because the driver is stopped or because another source of power increase the speed of the driven. This type of clutch usually uses rollers or balls mounted between an outer sleeve and an inner member having flats machined around the periphery. Driving action is obtained by wedding the rollers between the sleeve and the flats. The clutch is therefore equivalent to a pawl and ratchet with an infinite number of teeth.Magnetic fluid clutch or brake is a relatively new development which has two parallel magnetic plates. Between these plates is a lubricated magnetic powder mixture. An electromagnetic coil is inserted somewhere in the magnetic circuit. Bu varying the excitation to this coil, the shearing strength of the magnetic fluid mixture may be accurately controlled. Thus any condition from a full slip to a frozen lockup may be obtained.机械传动系统介绍在传统机械和现代机械中齿轮和轴的重要地位是不可动摇的。
机械工程毕业设计外文翻译
毕业设计论文外文资料原文及译文学院：机电工程学院专业：机械设计制造及其自动化班级：学号：姓名：Mechanical engineering1.The porfile of mechanical engineeringEngingeering is a branch of mechanical engineerig,it studies mechanical and power generation especially power and movement.2.The history of mechanical engineering18th century later periods,the steam engine invention has provided a main power fountainhead for the industrial revolution,enormously impelled each kind of mechznical biting.Thus,an important branch of a new Engineering – separated from the civil engineering tools and machines on the branch-developed together with Birmingham and the establishment of the Associantion of Mechanical Engineers in 1847 had been officially recognized.The mechanical engineering already mainly used in by trial and error method mechanic application technological development into professional engineer the scientific method of which in the research,the design and the realm of production used .From the most broad perspective,the demend continuously to enhance the efficiencey of mechanical engineers improve the quality ofwork,and asked him to accept the history of the high degree of education and training.Machine operation to stress not only economic but also infrastructure costs to an absolute minimun.3.The field of mechanical engineeringThe commodity machinery development in the develop country,in the high level material life very great degree is decided each kind of which can realize in the mechanical engineering.Mechanical engineers unceasingly will invent the machine next life to produce the commodity,unceasingly will develop the accuracy and the complexity more and more high machine tools produces the machine.The main clues of the mechanical development is:In order to enhance the excellent in quality and reasonable in price produce to increase the precision as well as to reduce the production cost.This three requirements promoted the complex control system development.The most successful machine manufacture is its machine and the control system close fusion,whether such control system is essentially mechanical or electronic.The modernized car engin production transmission line(conveyer belt)is a series of complex productions craft mechanizationvery good example.The people are in the process of development in order to enable further automation of the production machinery ,the use of a computer to store and handle large volumes of data,the data is a multifunctional machine tools necessary for the production of spare parts.One of the objectives is to fully automated production workshop,three rotation,but only one officer per day to operate.The development of production for mechanical machinery must have adequate power supply.Steam engine first provided the heat to generate power using practical methods in the old human,wind and hydropower,an increase of engin .New mechanical engineering industry is one of the challenges faced by the initial increase thermal effciency and power,which is as big steam turbine and the development of joint steam boilers basically achieved.20th century,turbine generators to provide impetus has been sustained and rapid growth,while thermal efficiency is steady growth,and large power plants per kW capital consumption is also declining.Finally,mechanical engineers have nuclear energy.This requires the application of nuclear energy particularly high reliability and security,which requires solving many new rge power plants and the nuclear power plant control systems have become highly complex electroonics,fluid,electricity,water and mechanical parts networks All in all areas related to the mechanical engineers.Small internal combustion engine,both to the type (petrol and diesel machines)or rotary-type(gas turbines and Mong Kerr machine),as well as their broad application in the field of transport should also due to mechanical enginerrs.Throughout the transport,both in the air and space,or in the terrestrial and marine,mechanial engineers created a variety of equipment and power devices to their increasing cooperation with electrical engineers,especially in the development of appropration control systems.Mechanical engineers in the development of military weapons technology and civil war ,needs a similar,though its purpose is to enhance rather than destroy their productivity.However.War needs a lot of resources to make the area of techonlogy,many have a far-reaching development in peacetime efficiency.Jet aircraft and nuclear reactors are well known examples.The Biological engineering,mechanical engineering biotechnology is a relatively new and different areas,it provides for the replacement of the machine or increase thebody functions as well as for medical equipment.Artficial limbs have been developed and have such a strong movement and touch response function of the human body.In the development of artificial organ transplant is rapid,complex cardiac machines and similar equipment to enable increasingly complex surgery,and injuries and ill patients life functions can be sustained.Some enviromental control mechanical engineers through the initial efforts to drainage or irrigation pumping to the land and to mine and ventilation to control the human environment.Modern refrigeration and air-conditioning plant commonaly used reverse heat engine,where the heat from the engine from cold places to more external heat.Many mechanical engineering products,as well as other leading technology development city have side effects on the environment,producing noise,water and air pollution caused,destroyed land and landscape.Improve productivity and diver too fast in the commodity,that the renewable naturalforces keep pace.For mechanical engineers and others,environmental control is rapidly developing area,which includes a possible development and production of small quantities of pollutants machine sequnce,and the development of new equipment and teachnology has been to reduce and eliminate pollution.4.The role of mechanical engineeringThere are four generic mechanical engineers in common to the above all domains function.The 1st function is the understanding and the research mechanical science foundation.It includes the power and movement of the relationship dynamics For example,in the vibration and movement of the relationship;Automatic control;Study of the various forms of heart,energy,power relations between the thermodynamic;Fluidflows; Heat transfer; Lubricant;And material properties.The 2nd function will be conducts the research,the desing and the development,this function in turn attempts to carry on the essential change to satisfy current and the future needs.This not only calls for a clear understanding of mechanical science,and have to breakdown into basic elements of a complex system capacity.But also the need for synthetic and innovative inventions.The 3rd function is produces the product and the power,include plan,operation and maintenance.Its goal lies in the maintenance eitherenhances the enterprise or the organization longer-tern and survivabilaty prestige at the same time,produces the greatest value by the least investments and the consumption.The 4th function is mechanical engineer’s coordinated function,including the management,the consultation,as well as carries on the market marking in certain situation.In all these function,one kind unceasingly to use the science for a long time the method,but is not traditional or the intuition method tendency,this is a mechanical engineering skill aspect which unceasingly grows.These new rationalization means typical names include:The operations research,the engineering economics,the logical law problem analysis(is called PABLA) However,creativity is not rationalization.As in other areas,in mechanical engineering,to take unexpected and important way to bring about a new capacity,still has a personal,marked characteristice.5.The design of mechanical engineeringThe design of mechanical is the design has the mechanical property the thing or the system,such as:the instrument and the measuring appliance in very many situations,the machine design must use the knowledge of discipline the and so on mathematics,materials science and mechanics.Mechanical engineering desgin includeing all mechanical desgin,but it was a study,because it also includes all the branches of mechsnical engineering,such as thermodynamics all hydrodynamics in the basic disciplines needed,in the mechanical engineering design of the initial stude or mechanical design.Design stages.The entire desgin process from start to finish,in the process,a demand that is designed for it and decided to do the start.After a lot of repetition,the final meet this demand by the end of the design procees and the plan.Design considerations.Sometimes in a system is to decide which parts needs intensity parts of geometric shapesand size an important factor in this context that we must consider that the intensity is an important factor in the design.When we use expression design considerations,we design parts that may affect the entire system design features.In the circumstances specified in the design,usually for a series of such functions must be taken into account.Howeever,to correct purposes,we should recognize that,in many cases thedesign of important design considerations are not calculated or test can determine the components or systems.Especially students,wheen in need to make important decisions in the design and conduct of any operation that can not be the case,they are often confused.These are not special,they occur every day,imagine,for example,a medical laboratory in the mechanical design,from marketing perspective,people have high expectations from the strength and relevance of impression.Thick,and heavy parts installed together:to produce a solid impression machines.And sometimes machinery and spare parts from the design style is the point and not the other point of view.Our purpose is to make those you do not be misled to believe that every design decision will needreasonable mathematical methods.Manufacturing refers to the raw meterials into finished products in the enterprise.Create three distinct phases.They are:input,processing exprot.The first phase includes the production of all products in line with market needs essential.First there must be the demand for the product,the necessary materials,while also needs such as energy,time,human knowledge and technology resourcess .Finall,the need for funds to obtain all the other resources. Lose one stage after the second phase of the resources of the processes to be distributed.Processing of raw materials into finished products of these processes.To complete the design,based on the design,and then develop plans.Plan implemented through various production processes.Management of resources and processes to ensure efficiency and productivity.For example,we must carefully manage resources to ensure proper use of funds.Finally,people are talking about the product market was cast.Stage is the final stage of exporting finished or stage.Once finished just purchased,it must be delivered to the users.According to product performance,installation and may have to conduct further debugging in addition,some products,especially those very complex products User training is necessary.6.The processes of materials and maunfacturingHere said engineering materials into two main categories:metals and non-ferrous,high-performance alloys and power metals.Non-metallic futher divided into plastice,synthetic rubber,composite materials and ceramics.It said the productionproccess is divided into several major process,includingshape,forging,casting/ founding,heat treatment,fixed/connections ,measurement/ quality control and materal cutting.These processes can be further divide into each other’s craft.Various stages of the development of the manufacturing industry Over the years,the manufacturing process has four distinct stages of development, despite the overlap.These stages are:The first phase is artisanal,the second Phase is mechanization.The third phase is automation the forth Phase is integrated.When mankind initial processing of raw materials into finished products will be,they use manual processes.Each with their hands and what are the tools manuslly produced.This is totally integrated production take shape.A person needs indentification,collection materials,the design of a product to meet that demand,the production of such products and use it.From beginning to end,everything is focused on doing the work of the human ter in the industrial revolution introduced mechanized production process,people began to use machines to complete the work accomplished previously manual. This led to the specialization.Specialization in turn reduce the manufacture of integrated factors.In this stage of development,manufacturing workers can see their production as a whole represent a specific piece of the part of the production process.One can not say that their work is how to cope with the entire production process,or how they were loaded onto a production of parts finished.Development of manufacting processes is the next phase of the selection process automation.This is a computer-controlled machinery and processes.At this stage,automation island began to emerge in the workshop lane.Each island represents a clear production process or a group of processes.Although these automated isolated island within the island did raise the productivity of indivdual processes,but the overall productivity are often not change.This is because the island is not caught in other automated production process middle,but not synchronous with them .The ultimate result is the efficient working fast parked through automated processes,but is part of the stagnation in wages down,causing bottlenecks.To better understand this problem,you can imagine the traffic in the peak driving a red light from the red Service Department to the next scene. Occasionally you will find a lot less cars,more than being slow-moving vehicles,but the results can be found by thenext red light Brance.In short you real effect was to accelerate the speed of a red Department obstruction offset.If you and other drivers can change your speed and red light simultaneously.Will advance faster.Then,all cars will be consistent,sommth operation,the final everyone forward faster.In the workshop where the demand for stable synchronization of streamlined production,and promoted integration of manufacturing development.This is a still evolving technology.Fully integrated in the circumstances,is a computer-controllrd machinery and processing.integrated is completed through computer.For example in the preceding paragraph simulation problems,the computer will allow all road vehicles compatible with the change in red.So that everyone can steady traffic.Scientific analysis of movement,timing and mechanics of the disciplines is that it is composed of two pater:statics and dynamics.Statics analyzed static system that is in the system,the time is not taken into account,research and analysis over time and dynamics of the system change.Dynameics from the two componets.Euler in 1775 will be the first time two different branches: Rigid body movement studies can conveniently divided into two parts:geometric and mechanics.The first part is without taking into account the reasons for the downward movement study rigid body from a designated location to another point of the movement,and must use the formula to reflect the actual,the formula would determine the rigid body every point position. Therefore,this study only on the geometry and,more specifically,on the entities from excision.Obviously,the first part of the school and was part of a mechanical separation from the principles of dynamics to study movement,which is more than the two parts together into a lot easier.Dynamics of the two parts are subsequently divided into two separate disciplines,kinematic and dynamics,a study of movement and the movement strength.Therefore,the primary issue is the design of mechanical systems understand its kinematic.Kinematic studies movement,rather than a study of its impact.In a more precise kinematic studies position,displacement,rotation, speed,velocity and acceleration of disciplines,for esample,or planets orbiting research campaing is a paradigm.In the above quotation content should be pay attention that the content of the Euler dynamics into kinematic and rigid body dynamics is based on the assumptionthat they are based on research.In this very important basis to allow for the treatment of two separate disciplines.For soft body,soft body shape and even their own soft objects in the campaign depends on the role of power in their possession.In such cases,should also study the power and movement,and therefore to a large extent the analysis of the increased complexity.Fortunately, despite the real machine parts may be involved are more or less the design of machines,usually with heavy material designed to bend down to the lowest parts.Therefore,when the kinematic analysis of the performance of machines,it is often assumed that bend is negligible,spare parts are hard,but when the load is known,in the end analysis engine,re-engineering parts to confirm this assnmption.机械工程1.机械工程简介机械工程是工程学的一个分支，它研究机械和动力的产，尤其是力和动力。
机械设计外文翻译(中英文)
Machine design theoryThe machine design is through designs the new product or improves the old product to meet the human need the application technical science. It involves the project technology each domain, mainly studies the product the size, the shape and the detailed structure basic idea, but also must study the product the personnel which in aspect the and so on manufacture, sale and use question.Carries on each kind of machine design work to be usually called designs the personnel or machine design engineer. The machine design is a creative work. Project engineer not only must have the creativity in the work, but also must in aspect and so on mechanical drawing, kinematics, engineerig material, materials mechanics and machine manufacture technology has the deep elementary knowledge.If front sues, the machine design goal is the production can meet the human need the product. The invention, the discovery and technical knowledge itself certainly not necessarily can bring the advantage to the humanity, only has when they are applied can produce on the product the benefit. Thus, should realize to carries on before the design in a specific product, must first determine whether the people do need this kind of productMust regard as the machine design is the machine design personnel carries on using creative ability the product design, the system analysis and a formulation product manufacture technology good opportunity. Grasps the project elementary knowledge to have to memorize some data and the formula is more important than. The merely service data and the formula is insufficient to the completely decision which makes in a good design needs. On the other hand, should be earnest precisely carries on all operations. For example, even if places wrong a decimal point position, also can cause the correct design to turn wrongly.A good design personnel should dare to propose the new idea, moreover is willing to undertake the certain risk, when the new method is not suitable, use original method. Therefore, designs the personnel to have to have to have the patience, because spendsthe time and the endeavor certainly cannot guarantee brings successfully. A brand-new design, the request screen abandons obsoletely many, knows very well the method for the people. Because many person of conservativeness, does this certainly is not an easy matter. A mechanical designer should unceasingly explore the improvement existing product the method, should earnestly choose originally, the process confirmation principle of design in this process, with has not unified it after the confirmation new idea.Newly designs itself can have the question occurrence which many flaws and has not been able to expect, only has after these flaws and the question are solved, can manifest new goods come into the market the product superiority. Therefore, a performance superior product is born at the same time, also is following a higher risk. Should emphasize, if designs itself does not request to use the brand-new method, is not unnecessary merely for the goal which transform to use the new method.In the design preliminary stage, should allow to design the personnel fully to display the creativity, not each kind of restraint. Even if has had many impractical ideas, also can in the design early time, namely in front of the plan blueprint is corrected. Only then, only then does not send to stops up the innovation the mentality. Usually, must propose several sets of design proposals, then perform the comparison. Has the possibility very much in the plan which finally designated, has used certain not in plan some ideas which accepts.How does the psychologist frequently discuss causes the machine which the people adapts them to operate. Designs personnel''s basic responsibility is diligently causes the machine to adapt the people. This certainly is not an easy work, because certainly does not have to all people to say in fact all is the most superior operating area and the operating process.Another important question, project engineer must be able to carry on the exchange and the consultation with other concerned personnel. In the initial stage, designs the personnel to have to carry on the exchange and the consultation on the preliminary design with the administrative personnel, and is approved. This generally is through the oral discussion, the schematic diagram and the writing material carries on. In order to carry on the effective exchange, needs to solve the following problem:(1) designs whether this product truly does need for the people? Whether there is competitive ability(2) does this product compare with other companies'' existing similar products?(3) produces this kind of product is whether economical?(4) product service is whether convenient?(5) product whether there is sale? Whether may gain?Only has the time to be able to produce the correct answer to above question. But, the product design, the manufacture and the sale only can in carry on to the above question preliminary affirmation answer foundation in. Project engineer also should through the detail drawing and the assembly drawing, carries on the consultation together with the branch of manufacture to the finally design proposal.Usually, can have some problem in the manufacture process. Possibly can request to some components size or the common difference makes some changes, causes the components the production to change easily. But, in the project change must have to pass through designs the personnel to authorize, guaranteed cannot damage the product the function. Sometimes, when in front of product assembly or in the packing foreign shipment experiment only then discovers in the design some kind of flaw. These instances exactly showed the design is a dynamic process. Always has a better method to complete the design work, designs the personnel to be supposed unceasingly diligently, seeks these better method.Recent year, the engineerig material choice already appeared importantly. In addition, the choice process should be to the material continuously the unceasing again appraisal process. The new material unceasingly appears, but some original materials can obtain the quantity possibly can reduce. The environmental pollution, material recycling aspect and so on use, worker''s health and security frequently can attach the new limiting condition to the choice of material. In order to reduce the weight or saves the energy, possibly can request the use different material. Comes from domestic and international competition, to product service maintenance convenience request enhancement and customer''s aspect the and so on feedback pressure, can urge the people to carry on to the material reappraises. Because the material does not select when created the product responsibility lawsuit, has already had the profoundinfluence. In addition, the material and between the material processing interdependence is already known by the people clearly. Therefore, in order to can and guarantees the quality in the reasonable cost under the premise to obtain satisfaction the result, project engineer makes engineers all to have earnestly carefully to choose, the determination and the use material.Makes any product the first step of work all is designs. Designs usually may divide into several explicit stages: (a) preliminary design; (b) functional design; (c) production design. In the preliminary design stage, the designer emphatically considered the product should have function. Usually must conceive and consider several plans, then decided this kind of thought is whether feasible; If is feasible, then should makes the further improvement to or several plans. In this stage, the question which only must consider about the choice of material is: Whether has the performance to conform to the request material to be possible to supply the choice; If no, whether has a bigger assurance all permits in the cost and the time in the limit develops one kind of new material.In the functional design and the engineering design stage, needs to make a practical feasible design. Must draw up the quite complete blueprint in this stage, chooses and determines each kind of components the material. Usually must make the prototype or the working model, and carries on the experiment to it, the appraisal product function, the reliability, the outward appearance and the service maintenance and so on. Although this kind of experiment possibly can indicate, enters in the product to the production base in front of, should replace certain materials, but, absolutely cannot this point take not earnestly chooses the material the excuse. Should unify the product the function, earnestly carefully considers the product the outward appearance, the cost and the reliability. Has the achievement very much the company when manufacture all prototypes, selects the material should the material which uses with its production in be same, and uses the similar manufacture technology as far as possible. Like this has the advantage very much to the company. The function complete prototype if cannot act according to the anticipated sales volume economically to make, or is prototypical and the official production installment has in the quality and the reliable aspect is very greatly different, then this kind of prototypedoes not have the great value. Project engineer is best can completely complete the material in this stage the analysis, the choice and the determination work, but is not remains it to the production design stage does. Because, is carries on in the production design stage material replacement by other people, these people are inferior to project engineer to the product all functions understanding. In the production design stage, is should completely determine with the material related main question the material, causes them to adapt with the existing equipment, can use the existing equipment economically to carry on the processing, moreover the material quantity can quite be easy to guarantee the supply.In the manufacture process, inevitably can appear to uses the material to make some changes the situation. The experience indicated that, may use certain cheap materials to take the substitute. However, in the majority situation, in will carry on the production later to change the material to have in to start before the production to change the price which the material will spend to have to be higher than. Completes the choice of material work in the design stage, may avoid the most such situations. Started after the production manufacture to appear has been possible to supply the use the new material is replaces the material the most common reason. Certainly, these new materials possibly reduce the cost, the improvement product performance. But, must carry on the earnest appraisal to the new material, guarantees its all performance all to answer the purpose. Must remember that, the new material performance and the reliable very few pictures materials on hand such understood for the people. The majority of products expiration and the product accident caused by negligence case is because in selects the new material to take in front of substitution material, not truly understood their long-term operational performance causes.The product responsibility lawsuit forces designs the personnel and the company when the choice material, uses the best procedure. In the material process, five most common questions are: (a) did not understand or cannot use about the material application aspect most newly the best information paper; (b) has not been able to foresee and to consider the dusk year possible reasonable use (for example to have the possibility, designs the personnel also to be supposed further to forecast and the consideration because product application method not when creates consequence.ecent years many products responsibilities lawsuit case, because wrongly uses theplaintiff which the product receives the injury to accuse produces the factory, and wins the decision); (c) uses the material data not entire perhaps some data are indefinite, works as its long-term performance data is the like this time in particular;(d) the quality control method is not suitable and not after the confirmation; (e) the personnel which completely is not competent for the post by some chooses the material.Through to the above five questions analysis, may obtain these questions is does not have the sufficient reason existence the conclusion. May for avoid these questions to these questions research analyses the appearance indicating the direction. Although uses the best choice of material method not to be able to avoid having the product responsibility lawsuit, designs the personnel and the industry carries on the choice of material according to the suitable procedure, may greatly reduce the lawsuit the quantity.May see from the above discussion, the choice material people should to the material nature, the characteristic and the processing method have comprehensive and thebasic understanding.翻译：机械设计理论机械设计，通过设计新产品或改进老产品，以满足人类需要的应用技术科学。
AxeBot机器人：全方位自主移动机器人的机械设计 毕业论文外文翻译
AxeBot Robot: The Mechanical Design for an Autonomous Omni directional Mobile RobotTiago P. do Nascimento, Augusto Loureiro da Costa, Cristiane Correa Paim Post-graduation Program in Electrical EngineeringUniversidade Federal da BahiaSalvador, Bahia, Brasiltiagopn@, augusto.loureiro@ufba.br, cpaim@ufba.brAbstractThe AxeBot robot‟s mechanical design, a fully autonomous mobile robot, for the RoboCup Small Size League, is presented in this paper. The AxeBot robot uses three omnidirectional wheels for movement and is equipped by a shooting device for shooting the ball in different directions. Once the AxeBot robot is a fully autonomous mobile robot all the sensors, engines, servos, batteries, and the computer system, must be embedded on. The project can be separated in four different parts: the chassis design, the wheel design, the shooting device design and the overall assembly which makes a shell design possible to cover the whole robot. The AxeBot mechanical design brings up a new chassis concept for three wheels omnidirectional robot, also present a new shooting device, and finally present AxeBots prototype assembly.1. IntroductionThe RoboCup Initiative is an international research group whose aims are to promote the fields of Robotics and Artificial Intelligence. A standard challenge, a soccer match performed by autonomous robot teams, was proposed in 1996 [1]. Initially with three different leagues 2D: Robot Soccer Simulation league, Small Size Robot league, and Middle Size Robot league. Nowadays these leagues have been increased up to: Four-Legged League, Humanoid League, Middle Size League, RoboCup Junior Soccer, Small Size League, Soccer Simulation, Standard Robot League. Also, another challenge, the RoboCup Rescue was proposed in 1999 to show that the result from the robot soccer research could be directly applied on a real world problem like a disaster rescue made by robots. Through the integration of technology and advanced computer algorithms, the goal of RoboCup is to build a team of humanoid robots that can beat the current World Cup champions by the year 2050. The AxeBot uses three omnidirectional wheels, positioned on a circle with an angle of 120o among each wheel, to move in different directions. Three Maxxon A-22 motors are used to drive the omnidirectional wheels, one motor per wheel. These motors are controlled by two Brainstem Moto 1.0 and a cascade controller made to control the robot trajectory [2] [3]. The AxeBot also holds a shooting device to kick the ball in different directions, a Vision System with a CMUCam Plus and GP202 Infra-red sensor [4], a embedded Computer System based on StrongArm, called StarGate Kit and a IEEE 802.11 wireless network card. This work presents the mechanical project to enclose these equipments into an fully autonomous omnidirectional robot calledAxeBot. The complete AxeBot dynamics and kinematics model can be found in [5], this model was used to specify some mechanical parameter, like the wheel diameter.2. The ChassisThe chassis of the robot is the frame to which all other components can be attached, directly or indirectly. Therefore the chassis must be strong enough to carry the weight of all parts when the robot is in rest o in movement. The chassis has to withstand the forces on it, caused by the acceleration of the robot as well. Another important requirement of the chassis is that it fixes all components in a stiff way, so that there will be small relative displacements of the components within the robot, during acceleration and deceleration. This is particular important for the three driving motors, which are positioned on the ground plane with an angle of 120o between each motor. The performance of the control of the robot is dependent on a precise and stiff placement of the motors [6]. The chassis has to be strong enough also to withstand a collision of the robotagainst the wall or against another robot, with the highest possible impact velocity that can occur. Finally the chassis has to be built with the smallest amount of material. At first to reduce the costs, and to minimize the total weight of the robot. Less weight requires less power to accelerate. So with the same motors, less weight gives you more acceleration. This is of course only true, when all the power generated by the motors can be transferred, via the wheels, to the ground. In other words, the wheels must have enough traction that there will be no slip between the wheels and the ground [7].2.1. MaterialFiberglass was used to build the chassis. This choice is purely financial, because the material is not expensive (although it is strong) and there is no need to hire a professional constructor. The building of all the chassis (six in total) can be done by the team members themselves. Only the moulds have to be built by a professional. The upper and lower chassis can be made using one mould that can be adjusted to produce the different chassis.2.2. DesignThe primary goal of the design is the fixation of the motors in the desired positions. Therefore a ground plate with 3 slots for the motors is modeled. At the front side each motor can be attached to the chassis. At the rim of the ground plate an edge is attached to give the chassis more torsion stiffness. This edge can also be used for attaching other components of the robot, like the covering shell. Also there is a cutout to create space for the shooting device of the robot. In section 5 the design of this device will be discussed. However no final design will be presented and therefore we stick with this assumption that the shooting device needs these cutouts. All edges are rounded, because this will make the construction of the easier part. The final part, the lower chassis, is shown in the figure below. This part is modeled in Solid Edge. To get a stiffer and stronger chassis, a second chassis part, the upper chassis, is modeled. This is almost an exact copy of the first part, only now there are 3 cutouts that provide more space for placing the components of the robot. These cutouts also save some material and therefore weight. The both parts are This sandwich construction gives thewhole chassis more stiffness, and so the total thickness of both the chassis can probably be lower than using one chassis part.Figure 1: Lower chassisFigure 2: Upper and lower chassis attached to each other2.3. Chassis mouldTo build these parts, a mould was made. This is just a negative of the actual robot parts. In figure 3 the mould of the upper chassis. To change this mould in the mould for the lower chassis, where the ground plate does not have holes, the indicated pieces (with white stripes) and the not indicated left piece (symmetric to the most right part) should be lowered 4 mm. For the upper and lower chassis, the basis mould is exactly the same. Only piece one and two are different for the two chassis, the motor piece and the shooting system piece are the same.Figure 3: Chassis mould3. WheelsThe AxeBot robot is equipped with three wheels positioned on a circle with an angle of 120°among attached to each other as shown in the picture below.each wheel. These wheels have to enable the omnidirectionality of the AxeBot robot. This means that the wheels have to be able to let the robot make two translational movements (in x and y-direction, see figure 4) without rotating the robot around its z-axis (the axis perpendicular to the y and x-axis, that is rotation in figure 4). The wheels have also to enable a rotation of the total robot around the z-axis.Figure 4: AxeBot wheels positionsNevertheless, the wheels have to be as small and light as possible to minimize weight and moment of inertia but still remain usable and manageable. The wheels are based on an existing design of an omnidirectional wheel from the Cornell Robot 2003 [8]. Figure 5 shows an exploded view the final version of a wheel. The two shells are connected to each other by screws and hold every part on the right place. The hub is also attached to the shells by screws. The hub is mounted on the output axle of a motor by a screw to transfer the rotational output of a motor to the wheel. The rings of the rollers are in contact with the floor. A roller can rotate around its roller axle.As mentioned above, the wheel has to enable two translations (x and y, see figure 4) without rotating around its z-axis. The whole wheel ensures one translation by rotating around the output shaft of the motors while the rollers ensure the other translation. Combining these translations on a proper way a robot can move anywhere in a plane or make a rotation.3.1. RingThe ring is the only part of the wheel that is in contact with the floor. Note that a wheel can also be in contact with the floor by two rings. To obtain maximum grip (no slip) the Cornell Robot 2003 team first developed rollers without rings. The rollers had sharp edges to cut into the carpet of the football fieldfor maximum grip. This however ruined the carpet and rubber rings were added in the design to obtain maximum grip without ruining the carpet. The rings are circular with a circular profile.Figure 5: Exploded view of the wheelTherefore the rubber rings are also used for the AxeBot 2006. Rubber rings can be bought in several sizes and since they are highly elastic it wasn‟t difficult to find a ring of a right size. Since there are more than one …right sizes‟ and the geometry of the ring is that simple, no technical drawing of the ring was made.3.2. RollerThe geometry of the rollers may not restrict the rotation of the roller and should enable the placement of the rubber ring, without the ring falling off. This can be easily obtained (see drawings). The only problem is friction with their axles and with the shells.The geometry of the rollers can influence the friction with the shells and the friction with its roller axle. To minimize the possibility of wear on the contact area between the roller and the roller axle, this contact area should be as big as possible.When the torque of the motor is transferred through a roller to the ground (driving the robot), the roller that is on the ground is pressed against the shells. It will occur often that, in this situation, the desired driving direction also requires a rotation of the roller (then the summation of the two translational movements will results in the desired driving direction). The rotating roller is, in this situation, pressed against the shells which, in some cases, can result in wear of the roller and or the shells. This depends on the material of the roller, the material of the shell, the magnitude of the force which presses the surfaces on each other (in this case it is the torque of the motor) and the geometry of both contact surfaces. Only the materials and geometry can be chosen in the design process of the wheels.A small contact area results in low friction but possible wear of one of the two surfaces and though materials have to be used to avoid wear. A large contact area will not cause wear but will result in a large friction force. An optimum for the contact area and the materials has to be found. The geometry has to be machinable also. Problems that are mentioned above did not occur with the design of the rollers of the Cornell Robot 2003. Therefore the same geometry for the rollers is used for the AxeBot.The Cornell Robot 2003 team designed a wheel with 15 rollers that worked very well. Therefore also 15 rollers are used in each wheel of the AxeBot 2006.The prototypes of the wheels of the Cornell Robot 2003 first had Delrin rollers to minimize friction and weight. Delrin is a kind of plastic which is used with moving contact surfaces because of its low friction coefficients with other materials. After a few test with the prototype robot it became clear that the Delrin-rollers easily broke with a collision. Therefore the Cornell Robot 2003 was equipped with aluminum rollers. These were strong enough to withstand collisions and aluminum has a low density (compared to other metals).However, during other prototype tests of the Cornell Robot 2003 team some aluminum residue built up on the steel rollers axles. The Cornell Robot 2003 did not encounter problems due to the wearing of the aluminum rollers, but to optimize the design of the AxeBot wheels this problem was solved.To avoid wearing of the aluminum rollers other material for the axles can be used or the rollers can be made of a tougher material. After a few calculations it became clear that roller axles of Delrin (to reduce the friction) are strong enough (see the section about the axles), but it is not possible to produce thin bars of Delrin. Therefore steel axles are used, the same material as the roller axles of the Cornell Robot 2003.So to avoid wear of the rollers a more though material than aluminum has to be used for the rollers. Steel is more though and an easily obtainable and cheap material. Adisadvantage of steel compared to aluminum is its higher density. This will increase the moment of the inertia which …costs‟ more torque of the motor. The total moment of inertia of a wheel with steel rollers is 1.39×10−4kgm2 and the moment of inertia of a wheel with aluminum rollers is 1.30×10−4kgm2. Using steel rollers instead of aluminum rollers would increase the moment of inertia by 7 this increase is neglectable small and steel rollers can be used.Concerning friction, using steel rollers and steel axles is also better than using aluminum rollers and steel axles since the friction-coefficient between steel and steel is lower than that between steel and aluminum. A lubricant can also be used to even more reduce friction.3.3. Roller axleAs mentioned above, the use of Delrin for the roller axles was investigated since it would reduce the wear of the aluminum rollers. In a static situation was calculated whether Delrin axles of 2.4 mm diameter would be strong enough. This was also done in a dynamical situation (dropping the robot on the floor and landing on one roller), but without using a Finite Element Method this did not result in realistic results. When the total weight of 3.5 kg of one AxeBot 2006 would completely be on one roller axle this would result in a shear stress in the axle.In this situation the shear stress can be calculated by dividing the force on the axle (due to the weight of the AxeBot) by the area of the shear plane. The area of the shear plane is of course the area of a circle with a radius similar to the radius of the axles. Note that the weight of the AxeBot has to be divided by two since there are two shear planes in one axle.The magnitude of the shear stress would be 3.8 MPa. Delrin starts to plastically deform in due to shear at around 44 MPa. Statically, Delrin axles would be strong enough.However, this calculation was not necessary it became clear that it is not possible to produce Delrin bars of 2.5 mm (diameter). Therefore steel axles will be used (aluminum axles would result in more friction). To reduce friction, the axles were coated with a lubricant like carbon. Lubricants like carbon are easily available.The Cornell robot team 2003 documentation does not mention problems of wear of their polycarbonate shells due to their steel roller axles. As one can be read further down this section, the shells of the AxeBot wheels will be made of aluminum or polycarbonate. The coefficient of friction between aluminum (shells) and steel (axles) and between polycarbonate (shells) and steel (axles) are of equal sizes (about 0.45 [-]). Also, the geometry of the wheels of the Cornell robot and the AxeBot are almost the same. Therefore it is most likely that wearing due to friction will not be a problem with steel roller axles and polycarbonate or aluminum shells.Production the axles can easily be made out of a steel bar. Depending on the available diameters of steel bars, the diameter of the axles could be adjusted. The edges of the axles are rounded to avoid sharp corners.3.4. HubThe hub connects the wheel to the axle of the motor. A M2-bolt can be used for this purpose, the hole in the hub where this bolt will be placed is dimensioned 1.5 mm indiameter so screw thread can be made to fit in the M2-bolt. The hub is connected to the shells by three M3-screws. Corresponding holes of 2.5 mm will be made in the hub and the shells. The geometry of the hub can be changed to facilitate the production process. The hub can be made out of aluminum or polycarbonate, both light materials. To investigate the option (and price) of injection moulding the hub out of polycarbonate a sketch of a design for a mould has been made.3.5. ShellsAlmost the all geometry of the shells of the Cornell Robot 2003 is used. Only little changes in the slots for the rollers of the axles have been made to facilitate the production process of the shells. In the section about the production of the shells a different design for the slots of the axles is presented to make the production of the shells easily.The shells can be made out of aluminum or a though, light plastic like polycarbonate. The Cornell Robot had shells of polycarbonate. The best machinable material is preferred, and the one used on the AxeBot‟s shell. Wh en using a plastic that can be injection molded, molds have been designed to check the prices of injection moulding.4. Shooting DeviceThis design consists of a vertical arm (the kick arm), that can swing around an axle which is fixed to the robot. This movement will be actuated by one of the two servos, the kicking servo, that is also fixed to the robot. The other servo, the directional servo, is attached to the bottom of the kick arm (the servosocket). A pendulum-like system is formed, so a large mass is concentrated in the lower part of a rotating arm. The kicking servo has a kicking plate attached to it which can rotate and thereby makes it possible to shoot in different directions. The kicking plate can be positioned very accurately since servos are designed for these kinds of tasks. The kicking plate is also connected to the servosocket. Therefore the collision force between the ball and the kicking plate will be guided to and divided by these two connection points. There will be less bending in the kicking platethen with one connection point and smaller reaction forces will act on the connection points.Figure 6: The AxeBot shooting device5. Shell and AxeBot AssemblyThe shell is the cover of the total robot. It will be made from fiberglass as well, for the same reasons as stated in the section about the chassis. In the figure below the design of the shell is shown. There are cutouts to make room for the wheels as well as for the shooting device. The diameter of the shell is 178 mm. Because the maximum allowable diameter is 180 mm, a margin of 2 mm is created.On top of the shell a vision system will be mounted. For the sake of compactness of the robot the height should be as small as possible, with all the parts fitting in. Thismould can be built with the simple milling machine that is available.To assemble the robot the most important demand is to obtain a total centre of gravity that has the lowest possible position in the robot. This will give the robot positive driving abilities. Another demand is of course that all the parts fit in the maximum height of 150 mm.To check this, all the parts of the robot have been modeled in Solid Edge. In figure 7 an exploded view of the total robot assembly is shown.The robot consists of an upper and lower chassis. Three motors with three omnidirectional wheels are attached to it. On the bottom of the robot, the two battery packs are placed, because these parts have the largest mass. The three motor processors are attached to two general processors. Also the overall processor with the data-transfer-unit is assembled. The latter parts are assembled in a way that is most compact. With this assembly it is possible for all parts to fit in a shell with height of 100 mm.A model for the shell of the robot is designed. Also a molt to produce these parts is modeled. It is possible to produce this model by using the milling machine that is available at the university. The assembly of all the parts, except the shooting device, shows that a shell height of 100 mm is possible.Figure 7: Exploded view of the total robot assemblyFigure 8: Total robot assembly6. ConclusionThe AxeBot mechanical design, a fully autonomous mobile robot, for the RoboCup Small Size League, was presented in this paper. This mechanical design brings up a new concept of chassis for three wheels omnidirectional mobile for RoboCup F-180 league, that can be built easily and cheap. Also a new effectuator mobile robot design for RoboCup F-180 league is presented here. This new effectuator allows the mobile robot to shoot the ball in different directions, instead of just shoot a head like the othershooting devices. Finally the mechanical project presented here encloses all part, sensor, actuators, effectuator, computer systems, wheels, chassis and cover shell into the AxeBot prototype. The AxeBot robot was concept for academical proposes, using the robot soccer as a laboratory to research in Autonomous Mobile Robots, Artificial Intelligence and related areas. Looking forward, in a few months, four more AxeBots are expected to be built like the two in figure 9. These robots will form the MecaTeam F-180, and height of 100 mm is possible.will support our research in to multi-robot systems, as it can be seen in figure 9 below.Figure 9: AxeBot photo7. References[1] Kitano, H. “Robocup: The robot world cup initiative”. In: Proc. of The First International Conference on Autonomous Agent (Agents-97)). Marina del Ray, The ACM Press. 1997.[2] Franco, A. C. “Geração e controle de tra jetória de robôs móveis omni-direcionais”, Master‟s thesis, Programa de Pós-Graduação Mecatrônica, UFBA. 2007.[3] PIRES, E. J. S.; MACHADO, J. A. T.; OLIVEIRA, P. B. de M. “Robot trajectory planning using multi-objective genetic algorithm optimization”. In: DEB, K. et al. (Ed.). GECCO (1). [S.l.]: Springer, 2004. (Lecture Notes in Computer Science, v. 3102), p.615-626. ISBN 3-540-22344-4.[4] Oliveira, L. R., Costa, A. L., Schnitman, L. and Souza, J. “An architecture of sensor fusion for spatial locat ion of objects in mobile robotics”, in B. H. Spring-Verlag (ed.), Encontro Português de Inteligência Artificial, EPIA‟2005, Covilhã, 2005. pp. 462–473.[5] Nascimento, T. P., Costa, A. L., Paim, C. C. “Uma abordagem multivariável para modelagem de robôs móveis omnidirecionais”, XVI CBA - Congresso Brasileiro de Automação. 2008.[6] ANGELES, J. “Fundamentals of Robotic Mechanical Systems: Theory, Methods, and Algorithms”. 2. ed. New York: Springer-Verlag New York, Inc., 2003. [7] B. Carter, M. Good, M. Dorohoff, J. Lew, R. L. W. II, and P. Gallina, “Mechanical design and modeling of an omni-directional robocup player,” in Proceedings RoboCup 2001 International Symposium, (Athens, Ohio), pp. 1–10, 2001.[8] Anderson, G., Chang, C., Chung, D., Evansic, L., Law, H., Richardson, S., Robers, J., Sterk, K. and Yim, J. 2003 cornell robocup, mechanical group final documentation, Technical report, /. 2003.翻译：AxeBot机器人：全方位自主移动机器人的机械设计摘要:这篇文章中介绍了一个用来参与机器人世界杯小尺寸等级比赛的完全自主移动AxeBot机器人的机械设计。
机械设计毕业论文外文翻译--机械产品方案的现代设计方法及发展趋势
Mechanical products of modern designmethodology and the programme trendsSummary: According to the current domestic and international product design, mechanical design scholars of the main features of thinking, product design methods summarized as a systematic programme, modular structure, based on product knowledge and wisdom of the four types. That the four methods of the organic link between features and its proposed product design computer programmes to achieve endeavors.Keyword:mechanical products; Programme design; TrendsIntroductionWith The rapid development of science and technology, the functional requirements of a growing number of products and complexity increase, shortened life expectancy, upgrading speed, the design of the products, particularly machinery products programme design are in urgent need .At present, computer-aided product design drawings, design calculations, processing manufacturing, production planning has been a relatively broad and in-depth study, but results and product development programme of the early computer-aided design falls far short of the design requirements. To this end, the author read a lot of literature on the basis of summarizing the design scholars and the methods used for programme design, and discussed ways of the organic link between the computer and mechanical products for programme design trends. Under the current design scholars and mechanical products used in the design of programmes of the main features of methods, the modern design of the programme approach can be summarized as the following four types:1. Systematic design methodologyThe main features of a systematic design methodology: design by several design elements as a system, the independence of each design element, the presence of various elements of the organic link between each element, and is layered, all elements of the design System design can achieve the required tasks. Systematic design concepts in the 1970s by the German scholar, Professor Paul and Baits, their theoretical system based on the general pattern set design, by design, should be rational. German Engineers in the design concepts on the basis ofcriteria developed VDI2221 "technical system design methodology and product development. Mechanical product development programmer design process model basically follows German standards VDI2221 design. In addition, many of our scholars in product design and programmer design was cited for the systematic design and other developed countries, including a representative is:(1) The user needs to be functional as a product of conception, design and structural components design, process planning, operational control of the foundation, from the macro-product development process starting, the use of qualitative methods of functional layout, systematic information to users needs rational and effective products into all stages of development objectives and technical control of the operations.(2) See product as the level of product life systems of organisms, and by systems theory to life the product design process can be divided effectively as demand levels, the achievement of the functional requirements of the specific design and product concept level. At the same time the use of life chart at abstract expression products functional requirements, and form the architecture of the products system.(3) Mechanical design system science applications into two basic issues: First, the design of products as a system to deal with, the best set of its components (modules) and their interrelationship; Second, product design process as a system, according to the design goals, and correctly, reasonably identify the various aspects of the design work and various design stages. Since each of the designers study and consider the perspective of the different focus, programmer design specific research methods are used to exist. The following are examples of some representative systematic design methods.1.1 "design analysis and guidance system"Kaleit with clear graphic description of levels of functional structures and related products abstract information systems achieved structural, functional relations graphics, modeling, and the functional connectivity between the layers. Will be designed into two complementary methods and the exchange of information, analytical methods used Nissans information can be used graphic symbols, a rich semantic model structure, can be described integration conditions, can be divided type, can be achieved in relations between the arbitrarycharacteristics, design methodology Xie and information technology integration, achieved design process information among different abstract level of relations graphics modeling. Documentation [11] network design will proceed as a design tool in the development of reactive ask semantic network design, the use of nodes and a network of lines to describe design nodes that components of the module (such as design tasks, functions, components or processing equipment), and lines to adjust the definition of nodes between different semantic relations, The design process for all the activities and results of a pre-established models for early design requirements definition to the specific description of each structure can be expressed by the relationship between the definition, computer-aided deplaning process to achieve a leap from abstract to concrete.1.2 Linkage chart lawIntegral components of the system can be divide into a functional energy, energy consumption, changing energy forms, such as various types of energy transmission, and a plan to borrow the functional components express their hope that will be based on a functional model and get a map of achieving functional structure of the automatic generation and functional structure with a map button automatic conversion, Kin seek Hop chart produced by the various design options to law.2. Structural modular design methodologyPlanning products from the perspective of: definition design tasks to the functional structure of products based products have been quoted solution (such as a spare parts components, etc.) to describe the design task of decomposition mandate to consider each sub-task existence counterpart solution of products, so that products can be in the planning stage for the elimination of the design tasks that may exist contradictions, Early projections production, costs and the development of the planned revision of the design process, thus increasing design efficiency and the reliability of the design, while also reducing the cost of new products. Feldman task to design the functions of the product mix is divided into four, (1) products → (2) functional composition→ (3) The main function of components → (4) functional components. Feature-oriented applications using structured catalogue of functional components that is more specific qualitative and quantitative description. At the same time developed a design suitablefor product development and early software tools used by early Start. Most of the functions that can be used for mechanical products have been solution, and with only a few new functions solution dedicated, specialized in the mechanical design of a functional product mix, dedicated machinery for the evaluation of the design, manufacture wind-very favorable. According to the connectivity features of mechanical parts will be consolidated into its four types:1) A direct positioning components, and since there is a readjustment of the components;2) Structure with the combination of common;3) Of a nest and the nest-style structure of the links-style components;4) A modular structure and modular components connectivity. And the use of symbols that prospective typical components and the inter-linking components rules, thus achieving connectivity between the components of the algorithms and concepts visualization.3. The characteristics of knowledge-based products in the designmethodologyDesign methods based on product characteristics knowledge of the main features: a computer language to describe the identification and design of products features experts in the field of knowledge and experience, knowledge base and establish the corresponding reasoning machine to use the storage areas have knowledge of the reasoning mechanism and the establishment of the programmer to achieve computer-assisted design products. Mechanical systems design of the programmer is based on products of the main features, and design experts in the field of knowledge and experience on the volume and decision-making, complete body type, a few integrated. Computer-aided design stage to achieve this, we must study the automatic acquisition of knowledge, expression, integration, coordination, management and use. To this end, and scholars in mechanical systems design knowledge of programmed design automated processing done a lot of research work, the methods used can be summarized in the following few.3.1 Coding methodAccording to motion transform (called functional element) the organization classified, and use codes to describe the types of institutions and function element, which has led to theestablishment of "body system programmer design expert systems" knowledge base. On this basis, binary logic of combining theory with vague integrated judge the establishment of the "expert system" reasoning mechanisms, and dedicated spaces for the four programmers designed machine tools. Use of biological evolutionary theory, through natural selection and sexual reproduction to enable organisms to the principles of evolution, in programmed design agencies, the use of network theory approach will map the structure of institutions for topography expression, and through the coding technology, the body structure and functions into individual chromosome number string of binary system, and prepared in accordance with design requirements to value use of biological evolution theory breeding control mechanism through selection, overlapping and sudden variations, and other means to eliminate low value-not to be very adaptive in the evolutionary process of the individual optimal, the best design for the agency.3.2 design catalogue methodConstruction of the "functional modules", "functional element" and "body group" - progression-style design catalogue, and this three-tiered progression of the design principles of the programmed catalogue as a mechanical transmission systems design knowledge base and the development of intelligent design aids.4. Intelligent design methodologyIntelligent design methodology is the main features: design methodology based on the theory that through 3D graphics software, intelligent design software and virtual reality technology, and multimedia, hypermedia tools for product development design, the idea expressed products, product description of the structure. In the use of mathematical systems theory, taking into a systems engineering theory, product design and system development methodologies VDI2221 technology, developed for use in the initial design of multimedia products developed software Muse.机械产品方案的现代设计方法及发展趋势摘要：根据目前国内外设计学者进行机械产品设计时的主要思维特点，将产品方案的设计方法概括为系统化、结构模块化、基于产品特征知识和智能四种类型。
机械设计制造及其自动化毕业论文中英文资料外文翻译
机械设计创造及其自动化毕业论文外文文献翻译INTEGRATION OF MACHINERY译文题目专业机械设计创造及其自动化外文资料翻译INTEGRATION OF MACHINERY（From ELECTRICAL AND MACHINERY INDUSTRY）ABSTRACTMachinery was the modern science and technology development inevitable result, this article has summarized the integration of machinery technology basic outline and the development background .Summarized the domestic and foreign integration of machinery technology present situation, has analyzed the integration of machinery technology trend of development.Key word： integration of machinery ，technology， present situation ，product t，echnique of manufacture ，trend of development0. Introduction modern science and technology unceasing development, impelled different discipline intersecting enormously with the seepage, has caused the project domain technological revolution and the transformation .In mechanical engineering domain, because the microelectronic technology and the computer technology rapid development and forms to the mechanical industry seepage the integration of machinery, caused the mechanical industry the technical structure, the product organization, the function and the constitution, the production method and the management systemof by machinery for the characteristic integration ofdevelopment phase.1. Integration of machinery outline integration of machinery is refers in the organization new owner function, the power function, in the information processing function and the control function introduces the electronic technology, unifies the system the mechanism and the computerization design and the software which constitutes always to call. The integration of machinery development also has become one to have until now own system new discipline, not only develops along with the science and technology, but also entrusts with the new content .But its basic characteristic may summarize is: The integration of machinery is embarks from the system viewpoint, synthesis community technologies and so on utilization mechanical technology, microelectronic technology, automatic control technology, computer technology, information technology, sensing observation and control technology, electric power electronic technology, connection technology, information conversion technology as well as software programming technology, according to the system function goal and the optimized organization goal, reasonable disposition and the layout various functions unit, in multi-purpose, high grade, redundant reliable, in the low energy consumption significance realize the specific function value, and causes the overall system optimization the systems engineering technology .From this produces functional system, then becomes an integration of machinery systematic or the integration of machinery product. Therefore, of coveringtechnology is based on the above community technology organic fusion one kind of comprehensive technology, but is not mechanical technical, the microelectronic technology as well as other new technical simple combination, pieces together .This is the integration of machinery and the machinery adds the machinery electrification which the electricity forms in the concept basic difference .The mechanical engineering technology has the merely technical to develop the machinery electrification, still was the traditional machinery, its main function still was replaces with the enlargement physical strength .But after develops the integration of machinery, micro electron installment besides may substitute for certain mechanical parts the original function, but also can entrust with many new functions,like the automatic detection, the automatic reduction information, demonstrate the record, the automatic control and the control automatic diagnosis and the protection automatically and so on .Not only namely the integration of machinery product is human's hand and body extending, human's sense organ and the brains look, has the intellectualized characteristic is the integration of machinery and the machinery electrification distinguishes in the function essence.2. Integration of machinery development condition integration of machinery development may divide into 3 stages roughly.20th century 60's before for the first stage, this stage is called the initial stage .In this time, the people determination not on own initiative uses the electronic technology the preliminary achievement to consummate the mechanical product the performance .Specially in Second World War period, the war has stimulated the mechanical product and the electronic technology union, these mechanical and electrical union military technology, postwar transfers civilly, to postwar economical restoration positive function .Developed and the development at that time generally speaking also is at the spontaneouscondition .Because at that time the electronic technology development not yet achieved certain level, mechanical technical and electronic technology union also not impossible widespread and thorough development, already developed the product was also unable to promote massively. The 20th century 70~80 ages for the second stage, may be called the vigorous development stage .This time, the computer technology, the control technology, the communication development, has laid the technology base for the integration of machinery development . Large-scale, ultra large scale integrated circuit and microcomputer swift and violent development, has provided the full material base for the integration of machinery development .This time characteristic is :①A mechatronics word first generally is accepted in Japan, probably obtains the quite widespread acknowledgment to 1980s last stages in the worldwide scale ;②The integration of machinery technology and the product obtained the enormous development ;③The various countries start to the integration of machinery technology and the product give the very big attention and the support. 1990s later periods, started the integration of machinery technology the new stagewhich makes great strides forward to the intellectualized direction, the integration of machinery enters the thorough development time .At the same time, optics, the communication and so on entered the integration of machinery, processes the technology also zhan to appear tiny in the integration of machinery the foot, appeared the light integration of machinery and the micro integration of machinery and so on the new branch; On the other hand to the integration of machinery system modeling design, the analysis and the integrated method, the integration of machinery discipline system and the trend of development has all conducted the thorough research .At the same time, because the hugeprogress which domains and so on artificial intelligence technology, neural network technology and optical fiber technology obtain, opened the development vast world for the integration of machinery technology .These research, will urge the integration of machinery further to establish the integrity the foundation and forms the integrity gradually the scientific system. Our country is only then starts from the beginning of 1980s in this aspect to study with the application .The State Councilsummary had considered fully on international the influence which and possibly brought from this about the integration of machinery technology developmenttrend .Many universities, colleges and institutes, the development facility and some large and middle scale enterprises have done the massive work to this technical development and the application, does not yield certain result, but and so on the advanced countries compared with Japan still has the suitable disparity.3. Integration of machinery trend of development integrations of machinery are the collection machinery, the electron, optics, the control, the computer, the information and so on the multi-disciplinary overlapping syntheses, its development and the progress rely on and promote the correlation technology development and the progress .Therefore, the integration of machinery main development direction is as follows:3.1 Intellectualized intellectualizations are 21st century integration of machinery technological development important development directions .Theartificial intelligence obtains day by day in the integration of machinery constructor's research takes, the robot and the numerical control engine bedis to the machine behavior description, is in the control theory foundation, the absorption artificial intelligence, the operations research, the computer science, the fuzzy mathematics, the psychology, the physiology and the chaos dynamics and so on the new thought, the new method, simulate the human intelligence, enable it to have abilities and so on judgment inference, logical thinking, independent decision-making, obtains the higher control goal in order to .Indeed, enable the integration of machinery product to have with the human identical intelligence, is not impossible, also is nonessential .But, the high performance, the high speed microprocessor enable the integration of machinery product to have preliminary intelligent or human's partial intelligences, then is completely possible and essential.In the modern manufacture process, the information has become the control manufacture industry the determining factor, moreover is the most active actuation factor .Enhances the manufacture system information-handling capacity to become the modern manufacture science development a key point .As a result of the manufacture system information organization and structure multi-level, makes the information the gain, the integration and the fusion presents draws up the character, information measure multi-dimensional, as well as information organization's multi-level .In the manufacture information structural model, manufacture information uniform restraint, dissemination processing and magnanimous data aspects and so on manufacture knowledge library management, all also wait for further break through.Each kind of artificial intelligence tool and the computation intelligence method promoted the manufacture intelligence development in the manufacture widespread application .A kind based on the biological evolution algorithm computation intelligent agent, in includes thescheduling problem in the combination optimization solution area of technology, receives the more and more universal attention, hopefully completes the combination optimization question when the manufacture the solution speed and the solution precision aspect breaks through the question scale in pairs the restriction .The manufacture intelligence also displays in: The intelligent dispatch, the intelligent design, the intelligent processing, the robot study, the intelligent control, the intelligent craft plan, the intelligent diagnosis and so on are various These question key breakthrough, may form the product innovation the basic research system. Between 2 modern mechanical engineering front science different science overlapping fusion will have the new science accumulation, the economical development and society's progress has had the new request and the expectation to the science and technology, thus will form the front science .The front science also has solved and between the solution scientific question border area .The front science has the obvious time domain, the domain and the dynamic characteristic .The project front science distinguished in the general basic science important characteristic is it has covered the key science and technology question which the project actual appeared.Manufacture system is a complex large-scale system, for satisfies the manufacture system agility, the fast response and fast reorganization ability, must profit from the information science, the life sciences and the social sciences and so on the multi-disciplinary research results, the exploration manufacture system new architecture, the manufacture pattern and the manufacture system effective operational mechanism .Makes the system optimization the organizational structure and the good movement condition is makes the system modeling , the simulation and the optimized essential target .Not only the manufacture system new architecture to makes the enterprise the agility and may reorganize ability to the demand response ability to have the vital significance, moreover to made the enterprise first floor production equipment the flexibility and may dynamic reorganization ability set a higher request .The biological manufacture view more and more many is introduced the manufacture system, satisfies the manufacture system new request.The study organizes and circulates method and technique of complicated system from the biological phenomenon, is a valid exit which will solve many hard nut to cracks that manufacturing industry face from now on currently .Imitating to living what manufacturing point is mimicry living creature organ of from the organization, from match more, from growth with from evolution etc. function structure and circulate mode of a kind of manufacturing system and manufacturing process.The manufacturing drives in the mechanism under, continuously by one's own perfect raise on organizing structure and circulating mode and thus to adapt the process of[with] ability for the environment .For from descend but the last product proceed together a design and make a craft rules the auto of the distance born, produce system of dynamic state reorganization and product and manufacturing the system tend automatically excellent provided theories foundation and carry out acondition .Imitate to living a manufacturing to belong to manufacturing science and life science of"the far good luck is miscellaneous to hand over", it will produce to the manufacturing industry for 21 centuries huge of influence .机电一体化摘要机电一体化是现代科学技术发展的必然结果,本文简述了机电一体化技术的基本概要和发展背景。
机械专业毕业设计外文翻译--选择最佳工具,几何形状和切削条件
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 be difficult 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 powerconsumption 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 using variance 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 used neural 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 theobjective 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 radius respectively, ∈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 ofthe 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 the opportunity 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 andtested 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. The hardness 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 terms of ln s, ln f , lnαand ln r. The analysis of the variance (ANOVA) 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 of58.39%. 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), fulfillingthe 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 to select 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。
机械设计制造及其自动化毕业设计外文翻译
英文原文名Automatic production line PLC control中文译文：自动化生产线自动上料站的PLC控制自动生产线是由工件传送系统和控制系统，将一组自动机床和辅助设备按照工艺顺序联结起来，自动完成产品全部或部分制造过程的生产系统，简称自动线。
二十世纪20年代，随着汽车、滚动轴承、小电机和缝纫机和其他工业发展,机械制造业开始出现在自动生产线,第一个是组合机床自动线。
在20世纪20年代,第一次出现在汽车工业流水生产线和半自动生产线,然后发展成自动生产线。
第二次世界大战后,在机械制造工业发达国家,自动生产线的数量急剧增加。
采用自动生产线生产的产品应该足够大,产品设计和技术应该是先进的、稳定的和可靠的,基本上保持了很长一段时间维持不变。
自动线用于大,大规模生产可以提高劳动生产率,稳定和提高产品质量,改善劳动条件,降低生产区域,降低生产成本,缩短生产周期,保证生产平衡、显著的经济效益。
自动生产线的一个干预指定的程序或命令自动操作或控制的过程,我们的目标是稳定、准确、快速。
自动化技术广泛用于工业、农业、军事、科学研究、交通运输、商业、医疗、服务和家庭,等自动化生产线不仅可以使人们从繁重的体力劳动、部分脑力劳动以及恶劣、危险的工作环境,能扩大人的器官功能,极大地提高劳动生产率,提高人们认识世界的能力,可以改变世界。
下面我说下它的应用范围：机械制造业中有铸造、锻造、冲压、热处理、焊接、切削加工和机械装配等自动线，也有包括不同性质的工序，如毛坯制造、加工、装配、检验和包装等的综合自动线。
加工自动线发展最快,应用最广泛的机械制造。
主要包括:用于处理盒、外壳、各种各样的部件,如组合机床自动线;用于加工轴、盘部分,由通用、专业化、或自动机器自动专线;转子加工自动线;转子自动线加工过程简单、小零件等。
1.确保节拍时间:无论什么样的产品,都必须完成的时间生产。
2.单元过程:只有一个产品,单位部分处理、组装、加工和材料。
外文翻译--机械设计简介
外文原文Introduction to Mechanical DesignMechanical design is the application of science and technology to devise new or improved products for the purpose of satisfying human needs. It is a vast field of engineering technology which not only concerns itself with the original conception of the product in terms of its size, shape and construction details, but also considers the various factors involved in the manufacture, marketing and use of the product.People who perform the various functions of mechanical design are typically called designers, or design engineers. Mechanical design is basically a creative activity. However, in addition to being innovative, a design engineer must also have a solid background in the areas of mechanical drawing, kinematics, dynamics, materials engineering, strength of materials and manufacturing processes.As stated previously, the purpose of mechanical design is to produce a product which will serve a need for man. Inventions, discoveries and scientific knowledge by themselves do not necessarily benefit people; only if they are incorporated into a designed product will a benefit be derived. It should be recognized, therefore, that a human need must be identified before a particular product is designed.Mechanical design should be considered to be an opportunity to use innovative talents to envision a design of a product, to analyze the system and then make sound judgments on how the product is to be manufactured. It is important to understand the fundamentals of engineering rather than memorize mere facts and equations. There are no facts or equations which alone can be used to provide all the correct decisions required to produce a good design. On the other hand, any calculation made must be done with the utmost care and precision. For example, if a decimal point is misplaced, a otherwise acceptable design may mot function.Good designs require trying mew ideas and being willing to take a certain amount of risk, knowing that if the mew idea does not work the existing method can bereinstated. Thus a designer must have patience, since there is no assurance of success for the time and effort expended. Creating a completely new design generally requires that many old and well-established methods be thrust aside. This is not easy since many people cling to familiar ideas, techniques and attitudes. A design engineer should constantly search for ways to improve an existing product and must decide what old, proven concepts should be used and what new, untried ideas should be incorporated.New designs generally have “bugs” or unforeseen which must be worked out before the superior characteristics of the new designs can be enjoyed. Thus there is a chance for a superior product, but only at higher risk. It should be emphasized that, if a design does not warrant radical new methods, such methods should not be applied merely for the sake of change.During the beginning stages of design, creativity should be allowed to flourish without a great number of constraints. Even though many impractical ideas may arise, it is usually easy to eliminate then in the early stages of design before firm details are required by manufacturing. In this way, Innovative ideas are not inhibited. Quite often, more than one design is developed, up to the point where they can be compared against each other. It is entirely possible that the design which is ultimately accepted will use ideas existing in one of the rejected designs that did not show as much overall promise.Psychologists frequently talk about trying to fit people to the machines they operate. It is essentially the responsibility of the engineer to strive to fit machines to people. This is not an easy task, since there is really no average person for which certain operating dimensions and procedures are optimum.Another important point which should be recognized is that a design engineer must be able to communicate ideas to other people if they ate to be incorporated. Communicating the design to others is the final, vital step in the design process. Undoubtedly many great designs, inventions, and creative works have been lost to mankind simply because the originators were unable or unable or unwilling to explain their accomplishments to others. Presentation is a selling job. The engineer whenpresenting a new solution to administrative, management, or supervisory persons, is attempting to sell or to prove to them that this solution is a better one. Unless this can be done successfully, the time and effort spent on obtaining the solution have been largely wasted.Basically, there ate only three means of communication available to us. These are the written, the oral, and the graphical forms. Therefore the successful engineer will be technically competent and versatile in all three forms of communication. A technically competent person who lacks ability in any one of these forms is severely handicapped. If ability in all three forms is lacking, no one will ever know how competent that person is!The competent engineer should not be afraid of the possibility of not succeeding in a presentation. In fact, occasional failure should be expected because failure or criticism seems to accompany every really creative idea. There is a great deal to learn from a failure, and the greatest gains ate obtained by those wiling to risk defeat. In the final analysis, the real failure would lie in decoding not to make the presentation at all. To communicate effectively, the following questions must be answered:1、Does the design really serve a human need?2、Will it be competitive with existing products of rival companies?3、It is economical to profit?4、Can it be readily maintained?5、Will it sell and make a profit?Only time will provide the true answers to the preceding questions, but the product should be designed, manufactured and marketed only with initial affirmative answers. The design engineer also must communicate the finalized design to manufacturing through the use of detail and assembly drawings.Quite often, a problem will occur during the manufacturing cycle. It may be that a exchange is required in the dimensioning or tolerancing of a part so that it can be more readily produced. This falls in the category of engineering changes which must be approved by the design engineer so that the product function will not be adversely affected. In other cases, a deficiency in the design may appear during assembly ortesting just prior to shipping.Engineering design is a systematic process by which solutions to the needs of humankind are obtained. The process is applied to problems (needs) of varying complexity. For example, mechanical engineers will use the design process to find an effective, efficient method to convert reciprocating motion to circular motion for the drive train in an internal combustion engine; electrical engineers will use the process to design electrical generating systems using falling water as the power source; and materials engineers use the process to design ablative materials which enable astronauts to safely the earth’s atmosphere.The va st majority of complex problems in today’s high technology society depend for solution not on a single engineering discipline, but on teams of engineers, scientists, environmentalists, economists, sociologists, and legal personnel. Solutions are not only dependent upon the appropriate applications of technology but also upon public sentiment, government regulations and political influence. As engineers we are empowered with the technical expertise to develop new and improved products and systems, but at the same time we must be increasingly aware of the impact of our actions on society and the environment in general and work conscientiously toward the best solution in view of all relevant factors.Design is the culmination of the engineering educational process; it is the salient feature that distinguishes engineering from other professions.A formal definition of engineering design is found in the curriculum guidelines of the Accreditation Board for Engineering and Technology (AENT). ABEN accredits curricula in engineering schools and derives its membership from the various engineering professional societies. Each accredited curriculum has a well-deigned design component which falls within the ABEN guideline. The ABEN statement on design reads as follows:Engineering design is the process of devising a system, component, or process to meet desired needs. It is a decision making process (often iterative ), in which the basic sciences, mathematic, and engineering sciences are applied to convert resources optimally to meet a stated objective. Among the fundamental elements of the designprocess are the establishment of objectives and criteria, synthesis, analysis, construction, testing, and evaluation. The engineering design component of a curriculum must include most of the following features: development of student creativity, use of open-ended problems, development and use of modern design theory mad methodology, formulation of design problem statements and specifications, consideration of alternative solutions, feasibility considerations, production processes, concurrent engineering design, and detailed system descriptions. Further, it is essential to include a variety of realistic constraints such as economic factors, safety, reliability, aesthetics, ethics, and social impact.If anything can be said about the last half of the twentieth century, it is that we have had an explosion of information. The amount of data that can be uncovered on most subjects is overwhelming. People in the upper levels of most organizations have assistants who condense most of the things that they must read, hear, or watch. When you begin a search for information, be prepared to scan many of your sources and document their location so that you can find them easily if the date subsequently appear to be important.Some of the sources that are available include the following:1、Exiting solutions. Much can be learned from the current status of solutions toa specific need if actual products can be located, studied and, in some cases, purchased for detailed analysis. An improved solution or an innovative new solution new solution cannot be found unless the existing solutions are thoroughly understood.2、Your library. Many universities have courses that teach you how to use your library. Such courses are easy when you compare them with those in chemistry and calculus, but their importance should not be underestimated. There are many sources in the library that can lead you to the information that you are seeking. You may find what you need in an index such as the Engineering Index. There are many other indexes that provide specialized information. The nature of your problem will direct which ones may be helpful to you. Don’t hesitate to ask for assistance from the librarian. You should use to advantage the computer databases found in libraries and often available through CD-ROM technology.3、Professional organizations. The American Society of Mechanical Engineers isa technical society that will be of interest to students majoring in mechanical engineering. Each major in your college is associated with not one but often several such societies. The National Society of Professional Engineers is an organization that most engineering students well eventually join, as well as at least one technical society such as the society of manufacturing engineers, the American Society of civil engineers (ASCE), or any one of dozens that serve the technical interests of the host of specialties with which professional practices seem most closely associated. May engineers are members of several associations and societies.4、Trade journals. They are published by the hundreds, usually specializing in certain classes of products and services. Money and economics are part of engineering design and decision making. We live in a society that is based on economics and competition. It is no doubt true that many good ideas never get tried because they are deemed to be economically infeasible. Most of us have been aware of this condition in our daily lives. We started with our parents explaining why we could not have some item that we wanted because it cost too much. Likewise, we will not put some very desirable component into our designs because the value gained will not return enough profit in relation to its cost.Industry is continually looking for new products of all types. Some are desired because the current product is not competing well in the marketplace. Others are tried simply because it appears that people will buy them. How do manufacturers know that a new product will be popular? They seldom know with certainty. Statistics is an important consideration in market analysis. Most of you will find that probability and statistics are an integral part of your chosen engineering curriculum. The techniques of this area of mathematics allow us to make inferences about how large groups of people react based on the reactions of a few.中文译文机械设计简介机械设计是为了满足人类需要而制定出的新产品或者改进旧产品时对科学与技术的应用。
精密机械加工工艺设计外文文献翻译
精密机械加工工艺设计外文文献翻译In the process of machining。
the XXX cutting force。
centrifugal force。
inertia force。
etc。
In order to ensure that the workpiece XXX external forces。
XXX displacement。
XXX workpiece.XXX Clamping DeviceThere are many types of clamping devices。
but their XXX.1.Power DeviceThe source of clamping force XXX force。
The device that can generate force is called the power device of the XXX used power devices include pneumatic devices。
hydraulic devices。
electric devices。
ic devices。
gas-liquid linkage devices。
XXX。
it does not have a power device.2.Clamping PartThe part that accepts and transfers the original force and transforms it into clamping force and performs XXX consists of the following mechanisms:1) Mechanisms that accept the original force。
such as handles。
nuts。
and mechanisms used to connect the XXX.2) Intermediate force transfer mechanisms。
机械毕业设计英文外文翻译213机械设计基础
附录(外文翻译——原文)Fundamentals of Mechanical DesignMechanical design means the design of things and systems of a mechanical nature—machines, products, structures, devices, and instruments. For the most part mechanical design utilizes mathematics, the materials sciences, and the engineering-mechanics sciences.The total design process is of interest to us. How does it begin? Does the engineer simply sit down at his desk with a blank sheet of paper? And, as he jots down some ideas, what happens next? What factors influence or control the decisions which have to be made? Finally, then, how does this design process end?Sometimes, but not always, design begins when an engineer recognizes a need and decides to do something about it. Recognition of the need and phrasing it in so many words often constitute a highly creative act because the need may be only a vague discontent, a feeling of uneasiness, of a sensing that something is not right.The need is usually not evident at all. For example, the need to do something about a food-packaging machine may be indicated by the noise level, by the variations in package weight, and by slight but perceptible variations in the quality of the packaging or wrap.There is a distinct difference between the statement of the need and the identification of the problem. which follows this statement. The problem is more specific. If the need is for cleaner air, the problem might be that of reducing the dust discharge from power-plant stacks, or reducing the quantity of irritants from automotive exhausts.Definition of the problem must include all the specifications for the thing that is to be designed. The specifications are the input and output quantities, the characteristics of the space the thing must occupy and all the limitations on these quantities. We can regard the thing to be designed as something in a black box. In this case we must specify the inputs and outputs of the box together with their characteristics and limitations. The specifications define the cost, the number to be manufactured, the expected life, the range, the operating temperature, and the reliability.There are many implied specifications which result either from the designer's particular environment or from the nature of the problem itself. The manufacturing processes which are available, together with the facilities of a certain plant, constitute restrictions on a designer's freedom, and hence are a part of the implied specifications. A small plant, for instance, may not own cold-working machinery. Knowing this, the designer selects other metal-processing methods which can be performed in the plant. The labor skills available and the competitive situation also constitute implied specifications.After the problem has been defined and a set of written and implied specifications has been obtained, the next step in design is the synthesis of an optimum solution. Now synthesis cannot take place without both analysis and optimization because the system under design must be analyzed to determine whether the performance complies with the specifications.The design is an iterative process in which we proceed through several steps, evaluate theresults, and then return to an earlier phase of the procedure. Thus we may synthesize several components of a system, analyze and optimize them, and return to synthesis to see what effect this has on the remaining parts of the system. Both analysis and optimization require that we construct or devise abstract models of the system which will admit some form of mathematical analysis. We call these models mathematical models. In creating them it is our hope that we can find one which will simulate the real physical system very well.Evaluation is a significant phase of the total design process. Evaluation is the final proof of a successful design, which usually involves the testing of a prototype in the laboratory. Here we wish to discover if the design really satisfies the need or needs. Is it reliable? Will it compete successfully with similar products? Is it economical to manufacture and to use? Is it easily maintained and adjusted? Can a profit be made from its sale or use?Communicating the design to others is the final, vital step in the design process. Undoubtedly many great designs, inventions, and creative works have been lost to mankind simply because the originators were unable or unwilling to explain their accomplishments to others. Presentation is a selling job. The engineer, when presenting a new solution to administrative, management, or supervisory persons, is attempting to sell or to prove to them that this solution is a better one. Unless this can be done successfully, the time and effort spent on obtaining the solution have been largely wasted.Basically, there are only three means of communication available to us. There are the written, the oral, and the graphical forms. Therefore the successful engineer will be technically competent and versatile in all three forms of communication. A technically competent person who lacks ability in any one of these forms is severely handicapped. If ability in all three forms is lacking, no one will ever know how competent that person is!The competent engineer should not be afraid of the possibility of not succeeding in a presentation. In fact, occasional failure should be expected because failure or criticism seems to accompany every really creative idea. There is a great to be learned from a failure, and the greatest gains are obtained by those willing to risk defeat. In the find analysis, the real failure would lie in deciding not to make the presentation at all.Introduction to Machine DesignMachine design is the application of science and technology to devise new or improved products for the purpose of satisfying human needs. It is a vast field of engineering technology which not only concerns itself with the original conception of the product in terms of its size, shape and construction details, but also considers the various factors involved in the manufacture, marketing and use of the product.People who perform the various functions of machine design are typically called designers, or design engineers. Machine design is basically a creative activity. However, in addition to being innovative, a design engineer must also have a solid background in the areas of mechanical drawing, kinematics, dynamics, materials engineering, strength of materials and manufacturing processes.As stated previously, the purpose of machine design is to produce a product which will serve a need for man. Inventions, discoveries and scientific knowledge by themselves do not necessarily benefit people; only if they are incorporated into a designed product will a benefit be derived. It should be recognized, therefore, that a human need must be identified before a particular product is designed.Machine design should be considered to be an opportunity to use innovative talents to envision a design of a product is to be manufactured. It is important to understand the fundamentals of engineering rather than memorize mere facts and equations. There are no facts or equations which alone can be used to provide all the correct decisions to produce a good design. On the other hand, any calculations made must be done with the utmost care and precision. For example, if a decimal point is misplaced, an otherwise acceptable design may not function.Good designs require trying new ideas and being willing to take a certain amount of risk, knowing that is the new idea does not work the existing method can be reinstated. Thus a designer must have patience, since there is no assurance of success for the time and effort expended. Creating a completely new design generally requires that many old and well-established methods be thrust aside. This is not easy since many people cling to familiar ideas, techniques and attitudes. A design engineer should constantly search for ways to improve an existing product and must decide what old, proven concepts should be used and what new, untried ideas should be incorporated.New designs generally have “bugs” or unforeseen problems which mu st be worked out before the superior characteristics of the new designs can be enjoyed. Thus there is a chance for a superior product, but only at higher risk. It should be emphasized that, if a design does not warrant radical new methods, such methods should not be applied merely for the sake of change.During the beginning stages of design, creativity should be allowed to flourish without a great number of constraints. Even though many impractical ideas may arise, it is usually easy to eliminate them in the early stages of design before firm details are required by manufacturing. In this way, innovative ideas are not inhibited. Quite often, more than one design is developed, up to the point where they can be compared against each other. It is entirely possible that the design which ultimately accepted will use ideas existing in one of the rejected designs that did not show as much overall promise.Psychologists frequently talk about trying to fit people to the machines they operate. It is essentially the responsibility of the design engineer to strive to fit machines to people. This is not an easy task, since there is really no average person for which certain operating dimensions and procedures are optimum.Another important point which should be recognized is that a design engineer must be able to communicate ideas to other people if they are to be incorporated. Initially the designer must communicate a preliminary design to get management approval. This is usually done by verbal discussions in conjunction with drawing layouts and written material. To communicate effectively, the following questions must be answered:(1)Does the design really serve a human need?(2)Will it be competitive with existing products of rival companies?(3)Is it economical to produce?(4)Can it be readily maintained?(5)Will it sell and make a profit?Only time will provide the true answers to the preceding questions, but the product should be designed, manufactured and marketed only with initial affirmative answers. The design engineer also must communicate the finalized design to manufacturing through the use of detailand assembly drawings.Quite often, a problem well occur during the manufacturing cycle. It may be that a change is required in the dimensioning or tolerancing of a part so that it can be more readily produced. This falls in the category of engineering changes which must be approved by the design engineer so that the product function will not be adversely affected. In other cases, a deficiency in the design may appear during assembly or testing just prior to shipping. These realities simply bear out the fact that design is a living process. There is always a better way to do it and the designer should constantly strive towards finding that better way.MachiningTurning The 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 and accuracy, are now at the designer's fingertips with production speeds 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, in terms of ability to repeat accurately and rapidly. Applying 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 turret 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 to set up on the turret lathe than on the automatic screw machine. Quantities less than 1000 parts may be more economical to set up on the turret lathe 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 upon material turned, tooling ,and fees and speeds employed, minimum tolerances that can be held on automatic tracer lathes are not necessarily the most economical tolerances.Is some case, 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.Milling With the exceptions of turning and drilling, milling is undoubtedly the most widely used method of removing metal. Well suited and readily adapted to the economical production of any quantity of parts, the almost unlimited versatility of the milling process merits the attention and consideration of designers seriously concerned with the manufacture of their product.As in any other process, parts that have to be milled should be designed with economical tolerances that can be achieved in production milling. If the part is designed with tolerances finer than necessary, additional operations will have to be added to achieve these tolerances——and this will increase the cost of the part.Grinding Grinding is one of the most widely used methods of finishing parts to extremely close tolerances and low surface roughness. Currently, there are grinders for almost for almost every type of grinding operation. Particular design features of a part dictate to a large degree the type of grinding machine required. Where processing costs are excessive, parts redesigned to utilize a less expensive, higher output grinding method may be well worthwhile. For example, wherever possible the production economy of centerless grinding should be taken advantage of by proper design consideration.Although grinding is usually considered a finishing operation, it is often employed as a complete machining process on work which can be ground down from rough condition without being turned or otherwise machined. Thus many types of forgings and other parts are finished completely with the grinding wheel at appreciable savings of time and expense.Classes of grinding machines include the following: cylindrical grinders, centerless grinders, internal grinders, surface grinders, and tool and cutter grinders.The cylindrical and centerless grinders are for straight cylindrical or taper work; thus splines, shafts, and similar parts are ground on cylindrical machines either of the common-center type or the centerless machine.Thread grinders are used for grinding precision threads for thread gages, and threads on precision parts where the concentricity between the diameter of the shaft and the pitch diameter of the thread must be held to close tolerances.The internal grinders are used for grinding of precision holes, cylinder bores, and similar operations where bores of all kinds are to be finished.The surface grinders are for finishing all kinds of flat work, or work with plain surfaces which may be operated upon either by the edge of a wheel or by the face of a grinding wheel. These machines may have reciprocating or rotating tables.(外文翻译——汉文)机械设计基础机械设计基础是指机械装置和机械系统——机器、产品、结构、设备和仪器的设计。
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机械设计摘要机器是机构与其他零件的组合，为了有益的用途而转换、传递或利用能量、力或者运动实例有发动机、涡轮、车辆、卷扬机、印刷机、洗衣机和电影摄影机.许多适用于机器设计的原理和力法也适用于不是真正机器的制成品，从轮毂盖和档案橱柜到仪表和核压力容器。
“机械设计”这一术语比“机器设计”更为广义，它包括机器设计。
而对于某些仪器，如用以确定热、流动线路和体积的热力以及流体方面的问题要单独考虑。
但是，在机械设计时要考虑运动和结构方面的问题以及保存和封装的规定。
在机械工程领域以及其他工程领域应用机械设计，都需要诸如开关、凸轮、阀门、容器和搅拌器等机械装置。
关键词：机械设计机构设计过程工差设计过程设计始于真正的或想象的需要。
现有的仪器可能需要在耐用性、效率、重量、速度或成本上加以改进。
可能需要新的仪器来完成以前由人做的功能，如装配或保养。
目标全部或部分地确定后，设计的下一步就是构思能够完成所需功能的机构及其布置为此，徒手画草图价值极大，它不但作为一个人想法的记录和与其他人讨论的辅助手段，而且尤其适于与自己的想法交流，作为创造性思路的兴奋剂还需要有关于部件的广泛知识，因为一台新机器常常由熟知的各类零件重新安排或替换而成，也许改变了尺寸和材料。
无论在构思过程中还是之后，一个设计者都会进行快速或粗略的计算或分析以确定一般尺寸和可行性。
当些关于所需或可用空间量的想法确定后，可以开始按比例画草图。
最后，一项基于功能和可靠性的设计完成了，就可以制造样机了。
如果测试满意，而且如果装置要大量生产，就要对最初的设计进行一定的修改以确保以较低成本大量生产。
在随后几年的制造和使用期间，设计有可能因构思了新想法或者基于测试和经验基础上的进一步分析所显示的改变而改变。
销售吸引力、客户满意度和制造成本都与设计有关，设计能力与工程投资的成功密切相关。
一些设计准则在这一部分，有人建议运用创造性的态度进行的分析，这种分析可以引起重大改进以及对备用产品的构思和完善，也许产品功能更多、更经济、更耐用。
创造阶段无须是最初和独立的阶段。
虽然分析人员可能并不负责整个设计，但是他不仅仅是能从数字上提出要他解决的问题的正确答案，不仅仅是给出应力值、尺寸或者工作限制。
他可以提出更广泛的见解，以便改进规范或方案。
由于在分析前或分析过程中，他会熟悉装置及其工作条件，他就处于一个构思备选方案的有利位置。
最好他能提出建议改变形状来消除力矩或应力集中，而不是允许构建具有大截面和过多动态载荷的机构最好是他报废他的细致的设计而不是后来看到机械报废。
为了激发创造性思维，建议设计人员和分析人员使用以下准则。
前6条准则尤其适用于分析人员，虽然他可能涉及到所有这10项。
1.创造性地利用所需的物理性能并控制不需要的。
2.认识实用载荷及其重要性。
3.预先考虑没有作用的载荷。
4.发明更有利的加载条件。
5.提供最小重量的最有利的应力分布和刚性。
6.用基本方程计算比例并使尺寸最优化。
7.选取材料以获得性能组合。
8.在备件和集成零件间仔细选择。
9.修改功能设计以适应生产过程和降低成本。
10.考虑装配中使部件精确定位和互不干扰。
机械设计整个机械设计是一个复杂的过程。
设计人员必须在这样的领域，如静力学、运动学、动力学和材料力学具有良好的素养，此外，还必须熟悉制造材料和制造工艺。
设计人员必须能够组合所有相关的事实，进行训渭、制作草图和制图来把制造要求传递到车间。
任何产品设计的第一步工作之一是选择用于制造每个部件的材料。
今天的设计人员可得到无数的。
在选择时，产品的功能、外观、材料成本和制造成本都很重要。
在任何计算之前必须仔细评估材料的性能。
有必要仔细计算以确保设计的有效性.计算从不出现在图上,而是由十各种原因被存起来。
一旦任何一个部件失效，就要弄清楚在最初设计这个有缺陷的零件时做了什么；而且，从对过去的项目的计算中可以获得一份经验文件。
当需要类似的设计时，过去的记录会有极大的帮助。
计算（和图上尺寸）的检查最为重要。
一个小数点放错位置可以毁掉一个本来可以接受的项目。
例如，如果一个人要设计一个能支撑100磅的托架，而它本应该能支撑1000磅，结果肯定会失败。
必须检查再检查设计工作的方方面面。
计算机对于工作人员来讲是一个很有用的工具，可以减轻乏味的计算并且对现有数据提供扩展分析。
基于计算机性能的交互系统使计算机辅助设计（CAD）和计算机辅助制造（CAM)成为可能。
通过这样的系统，就可能把一个初步构思传送到打孔纸带用于数字加工控制而无须绘制正式的施工图。
实验室测试、模型和样机对于机械设计很有帮助。
实验室提供了很多建立基本概念所需的信息，然而，还可用它们获得一些关于产品在现场会如何工作的认识最后，一个成功的设计人员应尽最大努力跟上时代步伐。
每天都会出现新材料和生产方法。
绘图和设计人员如果不熟悉现代方法和材料就可能失去作用。
一个好的设计人员应经常阅读技术期刊以跟上新的发展工程工差固体由其表面边界确定界限。
典型地，设计人员给一个零件指定公称尺寸以使其满足其需要。
实际上由于表面不规则以及固有的表面粗糙度，各个零件不能重复地做成公称尺寸必须允许尺寸有一些变化以确保能够制造。
但是，所允许的变化一定不能太大以至于使装配件的性能变差。
单个零件所允许的变化称为公差。
公差这一术语不仅适用于由制造工艺产生的部件尺寸的可以接受的范围，而且适用于机械或加工的输出。
例如，一个给定型号的内燃机的功率每台都有所变化。
实际上，我们常常发现这种变化模型会是频率分布曲线，例如t.态分布（又叫高斯分布）。
设计人员的工作之一就是给一个零件指定尺寸和允许的变化，这个值能够产生可以接受的性能。
零件公差当图中没有指定确切尺寸时，大多数组织都有适用于尺寸的通用公差。
对于加工尺寸，通用公差可能是±0.5毫米。
因此，被指定为15.0毫米的尺寸的范围可以是14.5毫米到15.5毫米之间。
其他通用公差可以适用于如角度、钻孔和冲孔，铸件、锻件、焊缝和焊角等情形。
在给一个零件指定公差时，可以参考以前的图或一般的工程实践。
典型的公差被指定为英武成JSO标准所定义的幅度。
对于一个给定公差，比如H7/s6，对于正在研究的零件尺寸就有一组与图表对应的数值可用。
下面这段将给出关于装入孔内的轴或柱形配合的具体例子。
孔和轴的标准配合一项标准的工程工作是确定一个柱形零件的公差，比如安装在一个相应的筒形零件或孔内的．或者是在其内部旋转的轴配合的松紧取决于应用例如，一个定位在轴上的齿轮就需要“紧”的静配合，这里轴的直径实际上比齿轮毅的内径稍微大一些以便能传递所需的扭矩。
再者，滑动轴承的直径必须大于轴的直径以使其旋转。
假定从经济上讲不能把部件制造成精确的尺寸，轴和孔尺寸上的大小变化就必须确定。
但是，变化的范围不应太大以免装配时受损为了不至于有无穷无尽的被指定的公差尺寸，已经制定了国家和国际标准确定了公差带，比如hll/cll。
为了使用这一资料，给出了传统公差使用中的定义。
通常使用的是基孔制，因为这会使公司内部所需的钻头、绞刀、拉刀和计量工具种类的减少。
尺寸：以专用单位表示尺寸数字值的数。
实际尺寸：通过测量得到的部件尺寸。
尺寸极限：零件允许的最大和最小尺寸。
最大尺寸极限：两个尺寸极限中较大的。
最小尺寸极限：两个尺寸极限中较小的基本尺寸：用以固定尺寸极限的参考尺寸偏差：一个尺寸与其对应的基本尺寸的代数差实际偏差：实际尺寸与其对应的基本尺寸的代数差。
上偏差：最大尺寸极限与其对应的基本尺寸的代数差下偏差：最小尺寸极限与其对应的基本尺寸的代数差公差：最大尺寸极限与最小尺寸极限的差值。
轴：指定一个部件所有外部特征的惯用术语孔：指定一个部件所有内部特征的惯用术语。
初步设计产生满足指定需求的解决方案。
初步设计可以代表组成整个系统的所有子系统和零部件的总和。
Ion和Smith把初步设计描述为由一系列形成和评估阶段组成的一个反复的过程，各阶段合在一起形成好的解决方案。
在反复的每一阶段，构思更加详细，可以更全面的评估。
产生尽可能多的或经济便利的构思和想法是重要的。
有一种诱惑，让你接受第一个有希望的构思并进行详细的设计直到最终产品。
应该抵抗这种诱惑，因为这样结果总会更好些。
值得一提的是，或早或晚你的设计会不得不与那些来自其他制造商的设计竞争，因此产生研制的思想应谨慎。
产生了想法和构思后，下一步就是对它们进行评估并选择最佳构思．一种评估方法是使用列表矩阵。
矩阵由一系列准则组成．构思必须借助它们打分。
如果合适，准则的重要性可以加权，最适合的构思会具有最高总分。
这一方法提供了组织的评估技术．而且使团队内的个人很难推行他们自己的不合理的想法。
产生了初步的解决方案，下一步就是表达它们，以便它们能与所有涉及总体设计过程的人交流实际上，这一步可以采用绘制草图或三维模型的形式，既可是物理模型也可是计算机生成的模型。
到总草图己经完成并进行计算来确定解决方案对于产品设计规范的兼容性时，细节设计阶段的基础就已建立起来了。
Mechanical DesignAbstract:A machine is a combination of mechanisms and other components which transforms, transmits, or utilizes energy, force, or motion for a useful purpose. Examples are engines, turbines, vehicles, hoists, printing presses, washing machines, and movie cameras. Many of the principles and methods of design that apply to machines also apply to manufactured articles that are not true machines, from hub caps and filing cabinets to instruments and nuclear pressure vessels. The term "mechanical design" is used in a broader sense than "machine design" to include their design. For some apparatus, the thermal and fluid aspects that determine the requirements of heat, flow path, and volume are separately considered. However, the motion and structural aspects and the provisions for retention and enclosure are considerations in mechanical design. Applications occur in the field of mechanical engineering, and in other engineering fields as well, all of which require mechanical devices, such as switches, cams, valves, vessels, and mixers.Keywords: Mechanical Designmechanisms Design Process ToleranceDesign processThe design begins from real of or the demand of imagination.The existing instrument may need to take in to improve on the enduring, efficiency, weight, speed or the cost.May need new instrument to complete before function done by person, such as Assemble or maintain.The target is all or partly after making sure, design of the next move is to conceive outline the organization that can complete the function needed and it arranges for this, drawing grass diagram to be worth barehanded biggest, it isn't only one personal record of viewpoint with with others discussion of assistance means, and be suitable for to communicate with own viewpoint particularly, is the stimulant which creates sex way of thinking to still need 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Last deviation:The biggest size extreme limit with it to should of the algebra of basic size badDescend deviation:Most baby size extreme limit with it to should of the algebra of basic size badBusiness trip:The biggest size extreme limit with most the bad value of baby size extreme limit.Stalk:Specifying an exterior characteristics with all parts consistently uses technical termBore:Specify a parts all internal characteristics to consistently use technical term.The initial design creation satisfies appointed demanding solution.The initial design can represent all sub- systems of constituting the whole system with the total of zero partses.Ion and Smith describe an initial design for is become by a series and evaluate a stage to constitute of an iterative process, each stage matches together to become a good solution.At each iterative stage conceive outline more in detail, can more overall valuation.Produce possibly many of or the economy is convenient of conceive outline and the viewpoint is important.There is 1 kind to lure, let you accept the first hopeful conceive outline and carry on a detailed design until end product.Should resist this kind of come-on, because of so as a result the head quarter is more quite a few.Well worth mentioning BE, or early or late your design would have to with those designs competitions which come from other manufactories, so the creation develop of the thoughts should be careful.Is to them to carry on valuation to combine choice next move after producing viewpoint and conceiving outline the best conceive outline.a kind of valuation method is to use row watch matrix.The matrix cons titutes to°from a series of standard. conceive outline have to ask for help them to beat a cent.If suitable, the importance of the standard can add power, conceiving outline most in keeping withly will have a tallest total cent.This method provided a built-up valuation technique. and make personal viewpoint that can hardly promote their own absurdity in the team.Produced the solution of first step, the next move was to express them, in order to they ability and all involve total design process of the persons communicate actually, this one step can adopt forms of drawing the grass diagram or 3D models, since but physical model also but the calculator born model. 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