R180柴油机曲轴工艺及夹具外文文献翻译、中英文翻译、外文翻译
机械加工工艺夹具类外文翻译、中英文翻译、外文文献翻译
附录翻译部分Lathe and TurningThe Lathe and Its ConstructionA lathe is a machine tool used primarily for producing surfaces of revolution flat edges. Based on their purpose ,construction , number of tools that can simultaneously be mounted , and degree of automation ,lathes or, more accurately, lathe-type machine tools can be classified as follows:(1) Engine lathes(2) Toolroom lathes(3) Turret lathes(4) Vertical turning and boring mills(5) Automatic lathes(6) Special-purpose lathesIn spite of that diversity of lathe-type machine tools, they all have all have common features with respect to construction and principle of operation .These features can best be illustrated by considering the commonly used representative type, the engine lathe. Following is a description of each of the main elements of an engine lathe , which is shown in Fig.11.1.Lathe bed . The lathe bed is the main frame , involving a horizontal beam on two vertical supporis. It is usually made of grey or nodular cast iron to damp vibrations and is made by casting . It has guideways to allow the carriage to slide easily lengthwise. The height of the lathe bed should be appropriate to enable the technician to do his or her jib easily and comfortably.Headstock. The headstock is fixed at the left hand side of the lathe bed and includes the spindle whose axis is parallel to the guideways (the silde surface of the bed) . The spindle is driven through the gearbox , which is housed within the headstock. The function of the gearbox is to provide a number of different spindle speeds (usually 6 up to 18 speeds) . Some modern lathes have headstocks with infinitely variable spindle speeds, which employ frictional , electrical , or hydraulic drives.The spindle is always hollow , I .e ,it has a through hole extending lengthwise. Bar stocks can be fed througth that hole if continous production is adopted . A lso , that hole has a taperedsurface to allow mounting a plain lathe center . The outer surface of the spindle is threaded to allow mounting of a chuck , a face plate , or the like .Tailstock . The tailstock assembly consists basically of three parts , its lower base, an intermediate part, and the quill . The lower base is a casting that can slide on the lathe bed along the guidewayes , and it has a clamping device to enable locking the entire tailstock at any desired location , depending upon the length of the workpiece . The intermediate parte is a casting that can be moved transversely to enable alignment of the axis of the the tailstock with that of the headstock . The third part, the quill, is a hardened steel tube, which can be moved longitudinally in and out of the intermediate part as required . This is achieved through the use of a handwheel and a screw , around which a nut fixed to the quill is can be locked at any point along its travel path by means of a clamping device.The carriage. The main function of the carriage is mounting of the cutting tools and generating longitudinal and /or cross feeds. It is actually an H-shaped block that slides on the lathe bed between the headstock and tailstock while being guided by the V-shaped guideways of the bed . The carriage can be moved either manually or mechanically by means of the apron and either the feed rod or the lead screw.When cutting screw threads, power is provided to the gearbox of the apron by the lead screw. In all other turning operations, it is the feed rod that drives the carriage. The lead screw goes through a pair o half nuts , which are fixed to the rear of the apron . When actuating a certain lever, the half nuts are clamped together and engage with the rotating lead screw as a single nut, which is fed , together with carriage, along the bed . when the lever is disengaged , the half nuts are released and the carriage stops. On the other hand , when the feed rod is used, it supplies power to the apron through a wrom gear . The latter is keyed to feed rod and travels with the apron along the feed rod , which has a keyway extending to cover its whole length. A modern lathe usually has a quick-change gearbox located under the headstock and driven from the spindle through a train of gears. It is connected to both the feed rod and the lead screw and enables selecting a variety of feeds easily and rapidly by simply shifting the appropriate levers, the quick-change gearbox is employed in plain turning, facing and thread cutting operations. Since that gearbox is linked to spindle, the distance that the apron (and the cutting tool) travels for each revolution of the spindle can be controlled and is referred to as the feed.Lathe Cutting ToolsThe shape and geometry of the lathe tools depend upon the purpose for which they are employed. Turning tools can be classified into tow main groups,namely,external cutting tools andinternal cutting tools , Each of these groups include the following types of tools: Turning tools. Turing tools can be either finishing or rough turning tools . Rough turning tools have small nose radii and are used for obtaining the final required dimensions with good surface finish by marking slight depth of cut . Rough turning tools can be right –hand or left-hand types, depending upon the direction of feed. They can have straight, bent, or offset shanks.Facing tools . Facing tools are employed in facing operations for machining plane side or end surfaces. There are tools for machining left-hand-side surfaces and tools for right-hand-side surfaces. Those side surfaces are generated through the use of the cross feed, contrary to turning operations, where the usual longitudinal feed is used.Cutoff tools. Cutoff tools ,which are sometimes called parting tools, serve to separate the workpiece into parts and/or machine external annual grooves.Thread-cutting tools. Thread-cutting tools have either triangular, square, or tranpezoidal cutting edges, depending upon the cross section of the desired thread .Also , the plane angles of these tools must always be identical to those of the thread forms. Thread-cutting tools have straight shanks for external thread cutting and are of the bent-shank type when cutting internal threads .Form tools. Form tools have edges especially manufactured to take a certain form, which is opposite to the desired shape of the machined workpiece . An HSS tools is usually made in the form of a single piece ,contrary to cemented carbides or ceramic , which are made in the form of tipes. The latter are brazed or mechanically fastened to steel shanks. Fig.1indicates an arrangement of this latter type, which includes the carbide tip , the chip breaker ,the pad ,the clamping screw (with a washer and a nut ) , and the shank.. As the name suggests, the function of the chip breaker is to break long chips every now and then , thus preventing the formation of very long twisted ribbons that may cause problems during the machining operations . The carbide tips ( or ceramic tips ) can have different shapes, depending upon the machining operations for which they are to be employed . The tips can either be solid or with a central through hole ,depending on whether brazing or mechanical clamping is employed for mounting the tip on the shank.Fig.1Lathe OperationsIn the following section , we discuss the various machining operations that can be performed on a conventional engine lathe. It must be borne in mind , however , that modern computerized numerically controlled lathes have more capabiblities and do other operations ,such as contouring , for example . Following are conventional lathe operations.Cylindrical turning . Cylindrical turning is the the simplest and the most common of all lathe operations . A single full turn of the workpiece generate a circle whose center falls on the lathe axis; this motion is then reproduced numerous times as a result of the axial feed motion of the tool. The resulting machining marks are , therefore ,a helix having a very small pitch, which is equal to the feed . Consequently , the machined surface is always cylindrical.The axial feed is provided by the carriage or the compound rest , either manually or automatically, whereas the depths of cuts is controlled by the cross slide . In roughing cuts , it is recommended that large depths of cuts (up to 0.25 in. or 6 mm, depending upon the workpiece material) and smaller feeds would be used. On the other hand , very fine feeds, smaller depth of cut (less than 0.05in. , or 0.4 mm) , and high cutting speeds are preferred for finishing cuts.Facing . The result of a facing operation is a flat surface that is either the whole end surface of the workpiece or an annular intermediate surface like a shoulder . During a facing operation ,feed is provided by the cross slide, whereas the depth of cut is controlled by the carriage or compound rest . Facing can be carried out either from the periphery in ward or from the center of the workpiece outward . It is obvious that the machining marks in both cases tack the form of a spiral. Usually, it is preferred to clamp the carriage during a facing operation, since the cutting force tends to push the tool ( and , of course , the whole carriage ) away from the workpiece . In most facing operations , the workpiece is held in a chuck or on a face plate.Groove cutting. In cut-off and groove-cutting operations ,only cross feed of the tool isemployed. The cut-off and grooving tools , which were previously discussed, are employed.Boring and internal turning . Boring and internal are performed on the internal surfaces by a boring bar or suitable internal workpiece is solid, a drilling operation must be performed first . The drilling tool is held in the tailstock, and latter is then fed against the workpiece.Taper turning . Taper turning is achieved by driving the tool in a direction that is not paralled to the lathe axis but inclined to it with an angle that is equal to the desired angle of the taper . Following are the different methods used in taper-turning practice:（1）Rotating the disc of the compound rest with an angle to half the apex angle of the cone . Feed is manually provided by cranking the handle of the compound rest . This method is recommended for taper turning of external and internal surfaces when the taper angle is relatively large.（2）Employing special form tools for external , very short ,conical surfaces . The width of the workpiece must be slightly smaller than that of the tool ,and the workpiece is usually held in a chuck or clamped on a face plate . I n this case , only the cross feed is used during the machining process and the carriage is clamped to the machine bed .（3）Offsetting the tailstock center . This method is employed for esternal tamper turning of long workpiece that are required to have small tamper angles (less than 8 ) . The workpiece is mounted between the two centers ; then the tailstock center is shifted a distance S in the direction normal to the lathe axis.（4）Using the taper-turning attachment . This method is used for turning very long workpoece , when the length is larger than the whole stroke of the compound rest . The procedure followed in such cases involves complete disengagement of the cross slide from the carriage , which is then guided by the taper-turning attachment . During this process, the automatic axial feed can be used as usual . This method is recommend for very long workpiece with a small cone angle , i.e. , 8 through 10 .Thread cutting . When performing thread cutting , the axial feed must be kept at a constant rate , which is dependent upon the rotational speed (rpm) of the workpiece . The relationship between both is determined primarily by the desired pitch of the thread to be cut .As previously mentioned , the axial feed is automatically generated when cutting a thread by means of the lead screw , which drives the carriage . When the lead screw rotates a single revolution, the carriage travels a distance equal to the pitch of the lead screw rotates a single revolutional speed of the lead screw is equal to that of the spindle ( i. e . , that of the workpiece ),the pitch of the resulting cut thread is exactly to that of the lead screw . The pitch of the resulting thread being cut therefore always depends upon the ratio of the rotational speeds of the lead scew and the spindle :workpiece of pitch screw lead the of Pitch Desired = screwlead of workpiece the of rpm rpm = spindle-to-carriage gearing ratio This equation is usefully in determining the kinematic linkage between the lathe spindle and the lead screw and enables proper selection of the gear train between them .In thread cutting operations , the workpiece can either be held in the chuck or mounted between the two lathe centers for relatively long workpiece . The form of the tool used must exactly coincide with the profile the thread to be cut , I . e . , triangular tools must be used for triangular threads , and so on .Knurling . knurling is mainly a forming operation in which no chips are prodyced . Tt involves pressing two hardened rolls with rough filelike surfaces against the rotating workpiece to cause plastic deformation of the workpiece metal.Knurling is carried out to produce rough , cylindrical ( or concile )surfaces , which are usually used as handles . Sometimes , surfaces are knurled just for the sake of decoration ; there are different types of patterns of knurls from which to choose .Cutting Speeds and FeedsThe cutting speed , which is usually given in surface feet per minute (SFM), is the number of feet traveled in circumferential direction by a given point on the surface (being cut ) of the workpiece in one minute . The relationship between the surface speed and rpm can be given by the following equation :SMF=πDNWhereD= the diameter of the workpiece in feetN=the rpmThe surface cutting speed is dependent primarily upon the machined as well as the material of the cutting and can be obtained from handbooks , information provided by cutting tool manufacturera , and the like . generally , the SFM is taken as 100 when machining cold-rolled or mild steel ,as 50 when machining tougher metals , and as 200 when machining sofer materials . For aluminum ,the SFMis usually taken as 400 or above . There are also other variables that affect the optimal value of the surface cutting speed . These include the toolgeometry, the type of lubricant or coolant , the feed , and the depth of cut . As soon as the cutting sped is decided upon , the rotational speed (rpm) of the spindle can be obtained as follows :N = DSFW π The selection of a suitable feed depends upon many factors , such as the required surface finish , the depth of cut , and the geometry of the tool used . Finer feeds produce better surface finish ,whereas higher feeds reduce the machining time during which the tool is in direct contact with the workpiece . Therefore ,it is generally recommended to use high feeds for roughing operations and finer feeds for finishing operations. Again, recommend values for feeds , which can be taken as guidelines , are found in handbooks and information booklets provided by cutting tool manufacturers.Here I want to introduce the drilling:Drilling involves producing through or blind holes in a workpiece by forcing a tool , which rotates around its axis , against the workpiece .Consequently , the range of cutting from that axis of rotation is equal to the radius of the required hole .In practice , two symmetrical cutting edges that rotate about the same axis are employed .Drilling operations can be carried out by using either hand drills or drilling machines . The latter differ in size and construction . nevertheless , the tool always rotates around its axis while the workpiece is kept firmly fixed . this is contrary to drilling on a lathe .Cutting Tool for Drilling OperationsIn drilling operations , a cylindrical rotary-end cutting , called a drill , is employed . The drill can have either one or more cutting edges and corresponding flutes , which can be straight or helical . the function of the flutes is to provide outlet passages for the chips generated during the drilling operation and to allow lubricants and coolants to reach the cutting edges and the surface being machined . Following is a survey of the commonly used drills.Twist drill . The twist drill is the most common type of drill .It has two cutting edges and two helical flutes that continue over the length of the drill body , The drill also consist of a neck and a shake that can be either straight or tapered .In the latter case , the shank is fitted by the wedge action into the tapered socket of the spindle and has a tang , which goes into a slot in the spindle socket ,thus acting as a solid means for transmitting rotation . On the other hand , straight –shank drills are held in a drill chuck that is , in turn , fitted into the spindle socket in the same way as tapered shank drills.The two cutting edges are referred to as the lips , and are connected together by a wedge , which is a chisel-like edge . The twist drill also has two margins , which enable proper guidance and locating of the drill while it is in operation . The tool point angle (TPA) is formed by the lips and is chosen based on the properties of the material to be cut . The usual TAP for commercial drills is 118 , which is appropriate for drilling low-carbon steels and cast irons . For harder and tougher metals , such as hardened steel , brasss and bronze , larger TPAs (130 OR 140 ) give better performance . The helix angle of the flutes of the commonly used twist drills ranges between 24 and 30 . When drilling copper or soft plastics , higher values for the helix angle are recommended (between 35 and 45).Twist drills are usually made of high speed steel ,although carbide tipped drills are also available . The size of twist drills used in industrial range from 0.01 up to 3.25 in . (i.e.0.25 up to 80 mm ) .Core drills . A core drill consists of the chamfer , body , neck ,and shank . This type of drill may be have either three or four flutes and an equal number of margins , which ensure superior guidance , thus resulting in high machining accuracy . It can also be seen in Fig 12.2 that a core drill has flat end . The chamfer can have three or four cutting edges or lips , and the lip angle may vary between 90 and 120 . Core drills are employed for enlarging previously made holes and not for originating holes . This type of drill is characterized by greater productivity , high machining accuracy , and superior quality of the drilled surfaces .Gun drills . Gun drills are used for drilling deep holes . All gun drills are straight fluted , and each has a single cutting edge . A hole in the body acts as a conduit to transmit coolant under considerable pressure to the tip of the drill .There are two kinds of gun drills , namely , the center cut gun drill used for drilling blind holes and the trepanning drill . The latter has a cylindrical groove at its center , thus generating a solid core , which guides the tool as it proceeds during the drilling operation.Spade drills . Spade drills are used for drilling large holes of 3.5 in .(90 mm ) or more . Their design results in a marked saving in cost of the tool as well as a tangible reduction in its weight , which facilitates its handling . moreover , this type of drill is easy to be ground .[13]车床和车削车床及它的结构车床是一个主要用来生产旋转表面和端面的机床。
R180柴油机曲轴工艺设计及夹具设计毕业设计说明书
R180柴油机曲轴工艺设计及夹具设计毕业设计说明书摘要 1 Abstract 20 引言 11 R180柴油机曲轴工艺设计 3 1.1 分析零件图 31.2 确定生产类型 31.3 确定毛坯 31.4 机械加工工艺过程设计 31.5 选择加工设备与工艺装备 61.6 确定工序尺寸 71.7 确定切削用量及时刻定额 91.8 填写工艺规程卡 152.1 明确设计任务、收集分析原始资料 162.2 确定夹具的结构方案 172.3 绘制夹具结构草图 193 R180柴油机曲轴第二套夹具设计 21 3.1 明确设计任务、收集分析原始资料 213.2 确定夹具的结构方案 223.3 夹具定位误差分析 223.4 拟订夹具总装图的尺寸、公差与配合及技术要求 223.5 绘制夹具总装图 234 结论 24致谢 25参考文献 26附件清单 27摘要本文要紧介绍了R180柴油机曲轴工艺设计及其中两道工序的夹具设计。
本文作者是在保证产品质量、提高生产率、降低成本、充分利用现有生产条件、保证工人具有良好而安全劳动条件的前提下进行设计的。
在工艺设计中，作者结合实际进行理论设计，对曲轴传统生产工艺进行了改进，优化了工艺过程和工艺装备，使曲轴的生产加工更经济、合理。
在夹具设计部分，作者在收集加工所用机床、刀具及辅助工具等有关资料后，对工件材料、结构特点、技术要求及工艺分析的基础上，按照夹具设计步骤设计出符合曲轴生产工艺及夹具制造要求的夹具。
关键词：柴油机曲轴工艺夹具AbstractThis text introduce R180 diesel engine crankshaft technological design and two of them jig of process design mainly. The author of this text is guaranteeing product quality, boost productivity, lower costs, utilize existing working condition, guaranteeing worker to have good work prerequisite of terms to design . In technological design, the author combine carrying on theory design, improve the traditional production technology of the crankshaft actually, optimize craft course and craft equip, enable economy rational even more of production and processing of the crankshaft. Designing in the jig , the author collect the relevant materials, such as lathe, cutter and handling tool，etc. At the foundation of the analyse of work piece material, specification requirement and craft, and make jig of request according to jig measure design and cankshaft production technology and jig.Keywords : Diesel engine Crankshaft Technology Jig0 引言全套图纸及更多设计请联系QQ：360702501本次毕业设计是关于R180柴油机曲轴的工艺设计及其中两道工序的夹具设计。
机械加工工艺装备夹具外文文献翻译、中英文翻译、外文翻译
外语文献翻译摘自: 《制造工程与技术（机加工）》（英文版）《Manufacturing Engineering and Technology —Machining 》机械工业出版社 2004年3月第1版 页—564560P美 s. 卡尔帕基安(Serope kalpakjian)s.r 施密德(Steven R.Schmid) 著原文：20.9 MACHINABILITYThe machinability of a material usually defined in terms of four factors:1、Surface finish and integrity of the machined part; 2、Tool life obtained; 3、Force and power requirements; 4、 Chip control.Thus, good machinability good surface finish and integrity, long tool life, and low force And power requirements. As for chip control, long and thin (stringy) cured chips, if not broken up, can severely interfere with the cutting operation by becoming entangled in the cutting zone.Because of the complex nature of cutting operations, it is difficult to establish relationships that quantitatively define the machinability of a material. Inmanufacturing plants, tool life and surface roughness are generally considered to be the most important factors in machinability. Although not used much any more, approximate machinability ratings are available in the example below.20.9.1 Machinability Of SteelsBecause steels are among the most important engineering materials (as noted in Chapter 5), their machinability has been studied extensively. The machinability of steels has been mainly improved by adding lead and sulfur to obtain so-called free-machining steels.Resulfurized and Rephosphorized steels. Sulfur in steels forms manganese sulfide inclusions (second-phase particles), which act as stress raisers in the primaryshear zone. As a result, the chips produced break up easily and are small; this improves machinability. The size, shape, distribution, and concentration of these inclusions significantly influence machinability. Elements such as tellurium and selenium, which are both chemically similar to sulfur, act as inclusion modifiers in resulfurized steels.Phosphorus in steels has two major effects. It strengthens the ferrite, causing increased hardness. Harder steels result in better chip formation and surface finish. Note that soft steels can be difficult to machine, with built-up edge formation and poor surface finish. The second effect is that increased hardness causes the formation of short chips instead of continuous stringy ones, thereby improving machinability.Leaded Steels. A high percentage of lead in steels solidifies at the tip of manganese sulfide inclusions. In non-resulfurized grades of steel, lead takes the form of dispersed fine particles. Lead is insoluble in iron, copper, and aluminum and their alloys. Because of its low shear strength, therefore, lead acts as a solid lubricant (Section 32.11) and is smeared over the tool-chip interface during cutting. This behavior has been verified by the presence of high concentrations of lead on thetool-side face of chips when machining leaded steels.When the temperature is sufficiently high-for instance, at high cutting speeds and feeds (Section 20.6)—the lead melts directly in front of the tool, acting as a liquid lubricant. In addition to this effect, lead lowers the shear stress in the primary shear zone, reducing cutting forces and power consumption. Lead can be used in every grade of steel, such as 10xx, 11xx, 12xx, 41xx, etc. Leaded steels are identified by the letter L between the second and third numerals (for example, 10L45). (Note that in stainless steels, similar use of the letter L means “low carbon,” a condition that improves their corrosion resistance.)However, because lead is a well-known toxin and a pollutant, there are serious environmental concerns about its use in steels (estimated at 4500 tons of lead consumption every year in the production of steels). Consequently, there is a continuing trend toward eliminating the use of lead in steels (lead-free steels). Bismuth and tin are now being investigated as possible substitutes for lead in steels.Calcium-Deoxidized Steels. An important development is calcium-deoxidized steels, in which oxide flakes of calcium silicates (CaSo) are formed. These flakes, in turn, reduce the strength of the secondary shear zone, decreasing tool-chip interfaceand wear. Temperature is correspondingly reduced. Consequently, these steels produce less crater wear, especially at high cutting speeds.Stainless Steels. Austenitic (300 series) steels are generally difficult to machine. Chatter can be s problem, necessitating machine tools with high stiffness. However, ferritic stainless steels (also 300 series) have good machinability. Martensitic (400 series) steels are abrasive, tend to form a built-up edge, and require tool materials with high hot hardness and crater-wear resistance. Precipitation-hardening stainless steels are strong and abrasive, requiring hard and abrasion-resistant tool materials.The Effects of Other Elements in Steels on Machinability. The presence of aluminum and silicon in steels is always harmful because these elements combine with oxygen to form aluminum oxide and silicates, which are hard and abrasive. These compounds increase tool wear and reduce machinability. It is essential to produce and use clean steels.Carbon and manganese have various effects on the machinability of steels, depending on their composition. Plain low-carbon steels (less than 0.15% C) can produce poor surface finish by forming a built-up edge. Cast steels are more abrasive, although their machinability is similar to that of wrought steels. Tool and die steels are very difficult to machine and usually require annealing prior to machining. Machinability of most steels is improved by cold working, which hardens the material and reduces the tendency for built-up edge formation.Other alloying elements, such as nickel, chromium, molybdenum, and vanadium, which improve the properties of steels, generally reduce machinability. The effect of boron is negligible. Gaseous elements such as hydrogen and nitrogen can have particularly detrimental effects on the properties of steel. Oxygen has been shown to have a strong effect on the aspect ratio of the manganese sulfide inclusions; the higher the oxygen content, the lower the aspect ratio and the higher the machinability.In selecting various elements to improve machinability, we should consider the possible detrimental effects of these elements on the properties and strength of the machined part in service. At elevated temperatures, for example, lead causes embrittlement of steels (liquid-metal embrittlement, hot shortness; see Section 1.4.3), although at room temperature it has no effect on mechanical properties.Sulfur can severely reduce the hot workability of steels, because of the formation of iron sulfide, unless sufficient manganese is present to prevent such formation. Atroom temperature, the mechanical properties of resulfurized steels depend on the orientation of the deformed manganese sulfide inclusions (anisotropy). Rephosphorized steels are significantly less ductile, and are produced solely to improve machinability.20.9.2 Machinability of Various Other MetalsAluminum is generally very easy to machine, although the softer grades tend to form a built-up edge, resulting in poor surface finish. High cutting speeds, high rake angles, and high relief angles are recommended. Wrought aluminum alloys with high silicon content and cast aluminum alloys may be abrasive; they require harder tool materials. Dimensional tolerance control may be a problem in machining aluminum, since it has a high thermal coefficient of expansion and a relatively low elastic modulus.Beryllium is similar to cast irons. Because it is more abrasive and toxic, though, it requires machining in a controlled environment.Cast gray irons are generally machinable but are. Free carbides in castings reduce their machinability and cause tool chipping or fracture, necessitating tools with high toughness. Nodular and malleable irons are machinable with hard tool materials.Cobalt-based alloys are abrasive and highly work-hardening. They require sharp, abrasion-resistant tool materials and low feeds and speeds.Wrought copper can be difficult to machine because of built-up edge formation, although cast copper alloys are easy to machine. Brasses are easy to machine, especially with the addition pf lead (leaded free-machining brass). Bronzes are more difficult to machine than brass.Magnesium is very easy to machine, with good surface finish and prolonged tool life. However care should be exercised because of its high rate of oxidation and the danger of fire (the element is pyrophoric).Molybdenum is ductile and work-hardening, so it can produce poor surface finish. Sharp tools are necessary.Nickel-based alloys are work-hardening, abrasive, and strong at high temperatures. Their machinability is similar to that of stainless steels.Tantalum is very work-hardening, ductile, and soft. It produces a poor surfacefinish; tool wear is high.Titanium and its alloys have poor thermal conductivity (indeed, the lowest of all metals), causing significant temperature rise and built-up edge; they can be difficult to machine.Tungsten is brittle, strong, and very abrasive, so its machinability is low,although it greatly improves at elevated temperatures.Zirconium has good machinability. It requires a coolant-type cutting fluid,however, because of the explosion and fire.20.9.3 Machinability of Various MaterialsGraphite is abrasive; it requires hard, abrasion-resistant, sharp tools.Thermoplastics generally have low thermal conductivity, low elastic modulus, and low softening temperature. Consequently, machining them requires tools with positive rake angles (to reduce cutting forces), large relief angles, small depths of cut and feed, relatively high speeds, andproper support of the workpiece. Tools should be sharp.External cooling of the cutting zone may be necessary to keep the chips from becoming “gummy” and sticking to the tools. Cooling can usually be achieved with a jet of air, vapor mist, or water-soluble oils. Residual stresses may develop during machining. To relieve these stresses, machined parts can be annealed for a period of time at temperatures ranging from C ︒80 to C ︒160 (F ︒175to F ︒315), and then cooled slowly and uniformly to room temperature.Thermosetting plastics are brittle and sensitive to thermal gradients duringcutting. Their machinability is generally similar to that of thermoplastics.Because of the fibers present, reinforced plastics are very abrasive and aredifficult to machine. Fiber tearing, pulling, and edge delamination are significant problems; they can lead to severe reduction in the load-carrying capacity of the component. Furthermore, machining of these materials requires careful removal of machining debris to avoid contact with and inhaling of the fibers.The machinability of ceramics has improved steadily with the development of nanoceramics (Section 8.2.5) and with the selection of appropriate processing parameters, such as ductile-regime cutting (Section 22.4.2).Metal-matrix and ceramic-matrix composites can be difficult to machine, depending on the properties of the individual components, i.e., reinforcing or whiskers, as well as the matrix material.20.9.4 Thermally Assisted MachiningMetals and alloys that are difficult to machine at room temperature can be machined more easily at elevated temperatures. In thermally assisted machining (hot machining), the source of heat—a torch, induction coil, high-energy beam (such as laser or electron beam), or plasma arc—is forces, (b) increased tool life, (c) use of inexpensive cutting-tool materials, (d) higher material-removal rates, and (e) reduced tendency for vibration and chatter.It may be difficult to heat and maintain a uniform temperature distribution within the workpiece. Also, the original microstructure of the workpiece may be adversely affected by elevated temperatures. Most applications of hot machining are in the turning of high-strength metals and alloys, although experiments are in progress to machine ceramics such as silicon nitride.SUMMARYMachinability is usually defined in terms of surface finish, tool life, force and power requirements, and chip control. Machinability of materials depends not only on their intrinsic properties and microstructure, but also on proper selection and control of process variables.译文：20.9 可机加工性一种材料的可机加工性通常以四种因素的方式定义：1、分的表面光洁性和表面完整性。
机械加工零件的工艺及夹具设计方案(中英文对照)
机械加工零件的工艺及夹具设计摘要：本文对机械加工零件的结构和工艺进行了分析，确定了机械加工工艺路线，夹具在机械加工中所占的地位和重要性，以及夹具设计。
随着科学的日益发展进步和国家产业政策的调整,工程机械行业已成为没有政策壁垒的完全竞争行业关键词：技术背景/发展趋势/工序/定位方案1 机械加工历史背景及其意义机械制造业是一个古老而永远充满生命力的行业。
随着现代工业的发展，对机械产品的要求越来越高，机械制造工艺也在日新月异地发展。
自新中国成立以来，我国的制造技术与制造业得到了长足发展，一个具有相当规模和一定技术基础的机械工业体系基本形成。
改革开放二十多年来，我国制造业充分利用国内国外两方面的技术资源，有计划地推进企业的技术改造，引导企业走依靠科技进步的道路，使制造技术、产品质量和水平及经济效益发生了显著变化，为推动国民经济的发展做出了很大的贡献。
尽管我国制造业的综合技术水平有了大幅度提高，但与工业发达国家相比，仍存在阶段性差距。
进入二十一世纪，我国发展经济的主导产业仍然是制造业，特别是在我国加入世贸组织后，世界的制造中心就从发达国家迁移到了亚洲，我国有廉价的劳动力和广大的消费市场，因此，我国工业要想发展，就需要有相应的技术和设备来支持。
机械工业是国民经济的装备工业；是科学技术物化的基础；是高新技术产业化的载体；是国防建设的基础；是实现经济快速增长的重要支柱；也是为提高人民生活质量、提供消费类机电产品的供应工业。
它对国民经济运行的质量和效益、产业结构的调整和优化具有极其重要的作用。
2 机械行业的现状及发展趋势随着社会的发展，各种机械逐渐运用到各个行业中，不管是在农用、军用、工用等方面，离开了机械的操作就谈不上效率，因此，从某中角度上来说，一个国家的经济实力、社会地位，和机械行业的发展是密不可分的。
各工业化国家经济发展的历程表明，没有强大的装备制造业，就不可能实现国民经济的工业化、现代化和信息化[3]。
柴油发动机喷射系统外文文献翻译、中英文翻译、外文翻译
译文标题柴油发动机喷射系统柴油发动机喷射系统 原文标题Diesel engine injection system 作 者Jeff Daniels 译 名 杰夫杰夫 丹尼斯丹尼斯 国 籍 美国美国原文出处 Automotive Design Asia 摘要：柴油喷射压力已提高到2000巴汽油直喷和压电技术都变得越来越常见因为燃油供给系统在不断地改革。
为燃油供给系统在不断地改革。
大约在过去的五年中汽车燃油供给技术发生了一场革命其中变化最大的是柴油发动机在直喷柴油机上运用了共轨系统该系统安装有压电式喷油器现在正受到人们越来越多的关注。
在汽油发动机方面现在也有往直喷技术发展的趋势但这种趋势逐渐趋缓而且并没有都往这个方向发展也有其它新的技术诸如空气引射技术但受材料方面的影响进展也较缓慢。
材料方面的影响进展也较缓慢。
关键词：燃油供给系统燃油供给系统 共轨系统共轨系统共轨系统 压电式喷油器压电式喷油器Abstract: the fuel injection pressure has increased to 2000 bar gasoline direct injection and piezoelectric technology is becoming more common because of fuel supply system in constant reform.About in the past five years automotive fuel oil supply technology was a revolution is one of the biggest changes in diesel engine on the direct injection diesel engine using common rail system is the system equipped with piezoelectric injector is now more and more attention by people. In gasoline engine now has to the trend of the development of the direct injection technology but the trend is gradually slow and not toward this direction also have other new technology such as air ejector technology but also affected by the material aspects of the progress is relatively slow.Keywords:fuel oil supply system Common rail system Piezoelectric injectors1喷射系统发展任何燃油供给系统最基本的功能是向每个汽缸供给足够的燃油通过这种方式任何燃油供给系统最基本的功能是向每个汽缸供给足够的燃油通过这种方式与吸进来的空气混合并燃烧当然燃烧得越完全越好。
R180柴油机曲轴工艺及夹具外文文献翻译、中英文翻译、外文翻译
中国地质大学长城学院本科毕业设计外文资料翻译系别：工程技术系专业：机械设计制造及其自动化姓名：刘庆鹏学号： 05211602年月日外文资料翻译原文R180柴油机曲轴工艺设计及夹具设计一、研究目的及意义曲轴是柴油机的关键零部件之一，主要用于往复运动的机械中，与连杆配合将作用在活塞上的气体压力变为旋转的动力。
而随着机械化生产逐渐成为当今主流，传统的制造工艺已经不能满足人们的需求。
结合实际进行理论分析，在保证产品质量，提高生产效率，降低生产成本的的前提下，对R180柴油机曲轴工艺进行优化设计。
二、R180曲轴工艺现状从目前的整体水平来看，R180柴油机曲轴基本都是两种材质：一是钢锻曲轴；二是球墨铸铁曲轴。
根据材质选择的不同，其生产方式也不同。
为了保证生产精度，铸造方式生产的曲轴已经广泛运用于R180柴油机的运行。
球墨铸铁具有良好的切削性能，并且可以进行各种热处理以及表面强化处理，故球墨铸铁被广泛运用于曲轴的生产。
但是，曲轴毛坯的铸造工艺生产效率低下，工艺装备参差不齐，性能不够稳定、精度低、报废率高居不下，这一系列的问题都需要优化。
从目前整体水平来看, 毛坯的铸造工艺存在生产效率低，工艺装备落后，毛坯机械性能不稳定、精度低、废品率高等问题。
从以下几个工艺环节采取措施对提高曲轴质量具有普遍意义。
①熔炼国内外一致认为,高温低硫纯净铁水的获得是生产高质量球铁的关键所在。
为获得高温低硫磷的纯净铁水，可用冲天炉熔化铁水，经炉外脱硫，然后在感应电炉中升温并调整成分。
②球化处理③孕育处理冲天炉熔化球铁原铁水,对铜钼合金球铁采用二次孕育。
这对于防止孕育衰退，改善石墨形态，细化石墨及保证高强度球铁机械性能具有重要作用。
④合金化配合好铜和钼的比例对形成珠光体组织十分有利,可提高球铁的强度,而且铜和钼还可大大降低球铁件对壁厚的敏感性。
⑤造型工艺气流冲击造型工艺优于粘土砂造型工艺，可获得高精度的曲轴铸件，该工艺制作的砂型具有无反弹变形量的特点,这对于多拐曲轴尤为重要。
(完整版)机械类外文文献翻译
文献翻译英文原文：NOVEL METHOD OF REALIZING THE OPTIMAL TRANSMISSION OF THE CRANK-AND-ROCKER MECHANISM DESIGN Abstract: A novel method of realizing the optimal transmission of the crank-and-rocker mechanism is presented. The optimal combination design is made by finding the related optimal transmission parameters. The diagram of the optimal transmission is drawn. In the diagram, the relation among minimum transmission angle, the coefficient of travel speed variation, the oscillating angle of the rocker and the length of the bars is shown, concisely, conveniently and directly. The method possesses the main characteristic. That it is to achieve the optimal transmission parameters under the transmission angle by directly choosing in the diagram, according to the given requirements. The characteristics of the mechanical transmission can be improved to gain the optimal transmission effect by the method. Especially, the method is simple and convenient in practical use.Keywords：Crank-and-rocker mechanism, Optimal transmission angle, Coefficient of travel speed variationINTRODUCTIONBy conventional method of the crank-and-rocker design, it is very difficult to realize the optimal combination between the various parameters for optimal transmission. The figure-table design method introduced in this paper can help achieve this goal. With given conditions, we can, by only consulting the designing figures and tables, get the relations between every parameter and another of the designed crank-and-rocker mechanism. Thus the optimal transmission can be realized.The concerned designing theory and method, as well as the real cases of its application will be introduced later respectively.1ESTABLISHMENT OF DIAGRAM FOR OPTIMAL TRANSMISSION DESIGNIt is always one of the most important indexes that designers pursue to improve the efficiency and property of the transmission. The crank-and-rocker mechanism is widely used in the mechanical transmission. How to improve work ability and reduce unnecessary power losses is directly related to the coefficient of travel speed variation, the oscillating angle of the rocker and the ratio of the crank and rocker. The reasonable combination of these parameters takes an important effect on the efficiency and property of the mechanism, which mainly indicates in the evaluation of the minimum transmission angle.The aim realizing the optimal transmission of the mechanism is how to find themaximum of the minimum transmission angle. The design parameters are reasonably combined by the method of lessening constraints gradually and optimizing separately. Consequently, the complete constraint field realizing the optimal transmission is established.The following steps are taken in the usual design method. Firstly, the initial values of the length of rocker 3l and the oscillating angle of rocker ϕ are given. Then the value of the coefficient of travel speed variation K is chosen in the permitted range. Meanwhile, the coordinate of the fixed hinge of crank A possibly realized is calculated corresponding to value K .1.1 Length of bars of crank and rocker mechanismAs shown in Fig.1, left arc G C 2 is the permitted field of point A . Thecoordinates of point A are chosen by small step from point 2C to point G .The coordinates of point A are 02h y y c A -= (1)22A A y R x -= (2)where 0h , the step, is increased by small increment within range(0,H ). If the smaller the chosen step is, the higher the computational precision will be. R is the radius of the design circle. d is the distance from 2C to G .2cos )2cos(22cos 33ϕθϕϕ⎥⎦⎤⎢⎣⎡--+=l R l d (3) Calculating the length of arc 1AC and 2AC , the length of the bars of themechanism corresponding to point A is obtained [1,2].1.2 Minimum transmission angle min γMinimum transmission angle min γ(see Fig.2) is determined by the equations [3]322142322min 2)(cos l l l l l l --+=γ (4) 322142322max 2)(cos l l l l l l +-+=γ (5) max min180γγ-︒=' (6) where 1l ——Length of crank(mm)2l ——Length of connecting bar(mm)3l ——Length of rocker(mm)4l ——Length of machine frame(mm)Firstly, we choose minimum comparing min γ with minγ'. And then we record all values of min γ greater than or equal to ︒40 and choose the maximum of them.Secondly, we find the maximum of min γ corresponding to any oscillating angle ϕ which is chosen by small step in the permitted range (maximum of min γ is different oscillating angle ϕ and the coefficient of travel speed variation K ).Finally, we change the length of rockerl by small step similarly. Thus we3γcorresponding to the different length of bars, may obtain the maximum ofmindifferent oscillating angle ϕand the coefficient of travel speed variation K.Fig.3 is accomplished from Table for the purpose of diagram design.It is worth pointing out that whatever the length of rocker 3l is evaluated, the location that the maximum of min γ arises is only related to the ratio of the length of rocker and the length of machine frame 3l /4l , while independent of 3l .2 DESIGN METHOD2.1 Realizing the optimal transmission design given the coefficient of travelspeed variation and the maximum oscillating angle of the rockerThe design procedure is as follows.(1) According to given K and ϕ, taken account to the formula the extreme included angle θ is found. The corresponding ratio of the length of bars 3l /4l is obtained consulting Fig.3.︒⨯+-=18011K K θ (7) (2) Choose the length of rocker 3l according to the work requirement, the length of the machine frame is obtained from the ratio 3l /4l .(3) Choose the centre of fixed hinge D as the vertex arbitrarily, and plot an isosceles triangle, the side of which is equal to the length of rocker 3l (see Fig.4), andϕ=∠21DC C . Then plot 212C C M C ⊥, draw N C 1, and make angleθ-︒=∠9012N C C . Thus the point of intersection of M C 2 and N C 1 is gained. Finally, draw the circumcircle of triangle 21C PC ∆.(4) Plot an arc with point D as the centre of the circle, 4l as the radius. The arc intersections arc G C 2 at point A . Point A is just the centre of the fixed hinge of the crank.Therefore, from the length of the crank2/)(211AC AC l -= (8)and the length of the connecting bar112l AC l -= (9)we will obtain the crank and rocker mechanism consisted of 1l , 2l , 3l , and 4l .Thus the optimal transmission property is realized under given conditions.2.2 Realizing the optimal transmission design given the length of the rocker (or the length of the machine frame) and the coefficient of travel speed variationWe take the following steps.(1) The appropriate ratio of the bars 3l /4l can be chosen according to given K . Furthermore, we find the length of machine frame 4l (the length of rocker 3l ).(2) The corresponding oscillating angle of the rocker can be obtained consulting Fig.3. And we calculate the extreme included angle θ.Then repeat (3) and (4) in section 2.13 DESIGN EXAMPLEThe known conditions are that the coefficient of travel speed variation1818.1=K and maximum oscillating angle ︒=40ϕ. The crankandrockermechanism realizing the optimal transmission is designed by the diagram solution method presented above.First, with Eq.(7), we can calculate the extreme included angle ︒=15θ. Then, we find 93.0/43=l l consulting Fig.3 according to the values of θ and ϕ.If evaluate 503=l mm, then we will obtain 76.5393.0/504==l mm. Next, draw sketch(omitted).As result, the length of bars is 161=l mm,462=l mm,503=l mm,76.534=l mm.The minimum transmission angle is︒=--+=3698.462)(arccos 322142322min l l l l l l γ The results obtained by computer are 2227.161=l mm, 5093.442=l mm, 0000.503=l mm, 8986.534=l mm.Provided that the figure design is carried under the condition of the Auto CAD circumstances, very precise design results can be achieved.4 CONCLUSIONSA novel approach of diagram solution can realize the optimal transmission of the crank-and-rocker mechanism. The method is simple and convenient in the practical use. In conventional design of mechanism, taking 0.1 mm as the value of effective the precision of the component sizes will be enough.译文：认识曲柄摇臂机构设计的最优传动方法摘要：一种曲柄摇臂机构设计的最优传动的方法被提出。
机械加工夹具外文翻译、加工基础外文文献翻译、中英文翻译
山东轻工业学院中英文翻译院系名称学生姓名专业班级指导教师二○**年五月十日Introduction of MachiningHave a shape as a processing method, all machining process for the production of the most commonly used and most important method. Machining process is a process generated shape, in this process, Drivers device on the workpiece material to be in the form of chip removal. Although in some occasions, the workpiece under no circumstances, the use of mobile equipment to the processing, however, the majority of the machining is not only supporting the workpiece also supporting tools and equipment to complete.Machining know the process has two aspects. Small group of low-cost production. For casting, forging and machining pressure, every production of a specific shape of the workpiece, even a spare part, almost have to spend the high cost of processing. Welding to rely on the shape of the structure, to a large extent, depend on effective in the form of raw materials. In general, through the use of expensive equipment and without special processing conditions, can be almost any type of raw materials, mechanical processing to convert the raw materials processed into the arbitrary shape of the structure, as long as the external dimensions large enough, it is possible. Because of a production of spare parts, even when the parts and structure of the production batch sizes are suitable for the original casting, Forging or pressure processing to produce, but usually prefer machining.Strict precision and good surface finish, machining the second purpose is the establishment of the high precision and surface finish possible on the basis of. Many parts, if any other means of production belonging to the large-scale production, Well Machining is a low-tolerance and can meet the requirements of small batch production. Besides, many parts on the production and processing of coarse process to improve its general shape of the surface. It is only necessary precision and chooses only the surface machining. For instance, thread, in addition to mechanical processing, almost no other processing method for processing. Another example is the blacksmith pieces keyhole processing, as well as training to be conducted immediately after the mechanical completion of the processing.Primary Cutting ParametersCutting the work piece and tool based on the basic relationship between the following four elements to fully describe: the tool geometry, cutting speed, feed rate, depth and penetration of a cutting tool.Cutting Tools must be of a suitable material to manufacture, it must be strong, tough, hard and wear-resistant. Tool geometry -- to the tip plane and cutter angle characteristics -- for each cutting process must be correct.Cutting speed is the cutting edge of work piece surface rate; it is inches per minute to show. In order to effectively processing, and cutting speed must adapt to the level of specific parts -- with knives. Generally, the more hard work piece material, the lower the rate.Progressive Tool to speed is cut into the work piece speed. If the work piece or tool for rotating movement, feed rate per round over the number of inches to the measurement. When the work piece or tool for reciprocating movement and feed rate on each trip through the measurement of inches. Generally, in other conditions, feed rate and cutting speed is inversely proportional to。
R180柴油机曲轴工艺设计及夹具设计毕业设计说明书
R180柴油机曲轴⼯艺设计及夹具设计毕业设计说明书R180柴油机曲轴⼯艺设计及夹具设计毕业设计说明书摘要 1 Abstract 20 引⾔ 11 R180柴油机曲轴⼯艺设计 3 1.1 分析零件图 31.2 确定⽣产类型 31.3 确定⽑坯 31.4 机械加⼯⼯艺过程设计 31.5 选择加⼯设备与⼯艺装备 61.6 确定⼯序尺⼨ 71.7 确定切削⽤量及时刻定额 91.8 填写⼯艺规程卡 152.1 明确设计任务、收集分析原始资料 162.2 确定夹具的结构⽅案 172.3 绘制夹具结构草图 193 R180柴油机曲轴第⼆套夹具设计 21 3.1 明确设计任务、收集分析原始资料 213.2 确定夹具的结构⽅案 223.3 夹具定位误差分析 223.4 拟订夹具总装图的尺⼨、公差与配合及技术要求 223.5 绘制夹具总装图 234 结论 24致谢 25参考⽂献 26附件清单 27摘要本⽂要紧介绍了R180柴油机曲轴⼯艺设计及其中两道⼯序的夹具设计。
本⽂作者是在保证产品质量、提⾼⽣产率、降低成本、充分利⽤现有⽣产条件、保证⼯⼈具有良好⽽安全劳动条件的前提下进⾏设计的。
在⼯艺设计中，作者结合实际进⾏理论设计，对曲轴传统⽣产⼯艺进⾏了改进，优化了⼯艺过程和⼯艺装备，使曲轴的⽣产加⼯更经济、合理。
在夹具设计部分，作者在收集加⼯所⽤机床、⼑具及辅助⼯具等有关资料后，对⼯件材料、结构特点、技术要求及⼯艺分析的基础上，按照夹具设计步骤设计出符合曲轴⽣产⼯艺及夹具制造要求的夹具。
关键词：柴油机曲轴⼯艺夹具AbstractThis text introduce R180 diesel engine crankshaft technological design and two of them jig of process design mainly. The author of this text is guaranteeing product quality, boost productivity, lower costs, utilize existing working condition, guaranteeing worker to have good work prerequisite of terms to design . In technological design, the author combine carrying on theory design, improve the traditional production technology of the crankshaft actually, optimize craft course and craft equip, enable economy rational even more of production and processing of the crankshaft. Designing in the jig , the author collect the relevant materials, such as lathe, cutter and handling tool，etc. At the foundation of the analyse of work piece material, specification requirement and craft, and make jig of request according to jig measure design and cankshaftproduction technology and jig.Keywords : Diesel engine Crankshaft Technology Jig0 引⾔全套图纸及更多设计请联系QQ：360702501本次毕业设计是关于R180柴油机曲轴的⼯艺设计及其中两道⼯序的夹具设计。
中英文文献翻译-切削加工工序和夹具设计
英文原文Cutting process and fixture designMachine tools have evolved from the early foot-powered lathes of the Egyptians and John Wilkinson's boring mill. They are designed to provide rigid support for both the workpiece and the cutting tool and can precisely control their relative positions and the velocity of the tool with respect to the workpiece. Basically, in metal cutting, a sharpened wedge-shaped tool removes a rather narrow strip of metal from the surface of a ductile workpiece in the form of a severely deformed chip. The chip is a waste product that is considerably shorter than the workpiece from which it came but with a corresponding increase in thickness of the uncut chip. The geometrical shape of workpiece depends on the shape of the tool and its path during the machining operation.Most machining operations produce parts of differing geometry. If a rough cylindrical workpiece revolves about a central axis and the tool penetrates beneath its surface and travels parallel to the center of rotation, a surface of revolution is produced, and the operation is called turning. If a hollow tube is machined on the inside in a similar manner, the operation is called boring. Producing an external conical surface uniformly varying diameter is called taper turning, if the tool point travels in a path of varying radius, a contoured surface like that of a bowling pin can be produced; or, if the piece is short enough and the support is sufficiently rigid, a contoured surface could be produced by feeding a shaped tool normal to the axis of rotation. Short tapered or cylindrical surfaces could also be contour formed.Flat or plane surfaces are frequently required. They can be generated by radial turning or facing, in which the tool point moves normal to the axis of rotation. In other cases, it is more convenient to hold the workpiece steady and reciprocate the tool across it in a series of straight-line cuts with a crosswise feed increment before each cutting stroke. This operation is called planning and is carried out on a shaper. For larger pieces it is easier to keep the tool stationary and draw the workpiece under it as in planning. The tool is fed at each reciprocation. Contoured surfaces can be produced by using shaped tools.Multiple-edged tools can also be used. Drilling uses a twin-edged fluted tool for holes with depths up to 5 to 10 times the drill diameter. Whether thedrill turns or the workpiece rotates, relative motion between the cutting edge and the workpiece is the important factor. In milling operations a rotary cutter with a number of cutting edges engages the workpiece. Which moves slowly with respect to the cutter. Plane or contoured surfaces may be produced, depending on the geometry of the cutter and the type of feed. Horizontal or vertical axes of rotation may be used, and the feed of the workpiece may be in any of the three coordinate directions.Basic Machine ToolsMachine tools are used to produce a part of a specified geometrical shape and precise I size by removing metal from a ductile material in the form of chips. The latter are a waste product and vary from long continuous ribbons of a ductile material such as steel, which are undesirable from a disposal point of view, to easily handled well-broken chips resulting from cast iron. Machine tools perform five basic metal-removal processes: I turning, planning, drilling, milling, and grinding. All other metal-removal processes are modifications of these five basic processes. For example, boring is internal turning; reaming, tapping, and counter boring modify drilled holes and are related to drilling; bobbing and gear cutting are fundamentally milling operations; hack sawing and broaching are a form of planning and honing; lapping, super finishing. Polishing and buffing are variants of grinding or abrasive removal operations. Therefore, there are only four types of basic machine tools, which use cutting tools of specific controllable geometry: 1. lathes, 2. planers, 3. drilling machines, and 4. milling machines. The grinding process forms chips, but the geometry of the abrasive grain is uncontrollable.The amount and rate of material removed by the various machining processes may be I large, as in heavy turning operations, or extremely small, as in lapping or super finishing operations where only the high spots of a surface are removed.A machine tool performs three major functions: 1. it rigidly supports the workpiece or its holder and the cutting tool; 2. it provides relative motion between the workpiece and the cutting tool; 3. it provides a range of feeds and speeds usually ranging from 4 to 32 choices in each case.Speed and Feeds in MachiningSpeeds, feeds, and depth of cut are the three major variables for economical machining. Other variables are the work and tool materials, coolant and geometry of the cutting tool. The rate of metal removal and power required for machining depend upon these variables.The depth of cut, feed, and cutting speed are machine settings that must be established in any metal-cutting operation. They all affect the forces, the power, and the rate of metal removal. They can be defined by comparing them to the needle and record of a phonograph. The cutting speed (V) is represented by the velocity of- the record surface relative to the needle in the tone arm at any instant. Feed is represented by the advance of the needle radially inward per revolution, or is the difference in position between two adjacent grooves. The depth of cut is the penetration of the needle into the record or the depth of the grooves.Turning on Lathe CentersThe basic operations performed on an engine lathe are illustrated. Those operations performed on external surfaces with a single point cutting tool are called turning. Except for drilling, reaming, and lapping, the operations on internal surfaces are also performed by a single point cutting tool.All machining operations, including turning and boring, can be classified as roughing, finishing, or semi-finishing. The objective of a roughing operation is to remove the bulk of the material as rapidly and as efficiently as possible, while leaving a small amount of material on the work-piece for the finishing operation. Finishing operations are performed to obtain the final size, shape, and surface finish on the workpiece. Sometimes a semi-finishing operation will precede the finishing operation to leave a small predetermined and uniform amount of stock on the work-piece to be removed by the finishing operation.Generally, longer workpieces are turned while supported on one or two lathe centers. Cone shaped holes, called center holes, which fit the lathe centers are drilled in the ends of the workpiece-usually along the axis of the cylindrical part. The end of the workpiece adjacent to the tailstock is always supported by a tailstock center, while the end near the headstock may be supported by a headstock center or held in a chuck. The headstock end of the workpiece may be held in a four-jaw chuck, or in a type chuck. This method holds the workpiece firmly and transfers the power to the workpiece smoothly; the additional support to the workpiece provided by the chuck lessens the tendency for chatter to occur when cutting. Precise results can be obtained with this method if care is taken to hold the workpiece accurately in the chuck.Very precise results can be obtained by supporting the workpiece between two centers. A lathe dog is clamped to the workpiece; together they are driven by a driver plate mounted on the spindle nose. One end of the Workpiece is mecained;then the workpiece can be turned around in the lathe to machine the other end. The center holes in the workpiece serve as precise locating surfaces as well as bearing surfaces to carry the weight of the workpiece and to resist the cutting forces. After the workpiece has been removed from the lathe for any reason, the center holes will accurately align the workpiece back in the lathe or in another lathe, or in a cylindrical grinding machine. The workpiece must never be held at the headstock end by both a chuck and a lathe center. While at first thought this seems like a quick method of aligning the workpiece in the chuck, this must not be done because it is not possible to press evenly with the jaws against the workpiece while it is also supported by the center. The alignment provided by the center will not be maintained and the pressure of the jaws may damage the center hole, the lathe center, and perhaps even the lathe spindle. Compensating or floating jaw chucks used almost exclusively on high production work provide an exception to the statements made above. These chucks are really work drivers and cannot be used for the same purpose as ordinary three or four-jaw chucks.While very large diameter workpieces are sometimes mounted on two centers, they are preferably held at the headstock end by faceplate jaws to obtain the smooth power transmission; moreover, large lathe dogs that are adequate to transmit the power not generally available, although they can be made as a special. Faceplatejaws are like chuck jaws except that they are mounted on a faceplate, which has less overhang from the spindle bearings than a large chuck would have.I ntroduction of MachiningMachining as a shape-producing method is the most universally used and the most important of all manufacturing processes. Machining is a shape-producing process in which a power-driven device causes material to be removed in chip form. Most machining is done with equipment that supports both the work piece and cutting tool although in some cases portable equipment is used with unsupported workpiece.Low setup cost for small Quantities. Machining has two applications in manufacturing. For casting, forging, and press working, each specific shape to be produced, even one part, nearly always has a high tooling cost. The shapes that may he produced by welding depend to a large degree on the shapes of raw material that are available. By making use of generally high cost equipment but without special tooling, it is possible, by machining; to start with nearly any form of raw material, so tong as the exterior dimensions are great enough, and produce any desired shape from any material. Therefore .machining is usually the preferred method for producing one or a few parts, even when the design of the part would logically lead to casting, forging or press working if a high quantity were to be produced.Close accuracies, good finishes. The second application for machining is based on the high accuracies and surface finishes possible. Many of the parts machined in low quantities would be produced with lower but acceptable tolerances if produced in high quantities by some other process. On the other hand, many parts are given their general shapes by some high quantity deformation process and machined only on selected surfaces where high accuracies are needed. Internal threads, for example, are seldom produced by any means other than machining and small holes in press worked parts may be machined following the press working operations.Primary Cutting ParametersThe basic tool-work relationship in cutting is adequately described by means of four factors: tool geometry, cutting speed, feed, and depth of cut.The cutting tool must be made of an appropriate material; it must be strong, tough, hard, and wear resistant. The tool s geometry characterized by planes and angles, must be correct for each cutting operation. Cutting speed is the rate at which the work surface passes by the cutting edge. It may be expressed in feet per minute.For efficient machining the cutting speed must be of a magnitude appropriate to the particular work-tool combination. In general, the harder the work material, the slower the speed.Feed is the rate at which the cutting tool advances into the workpiece. "Where the workpiece or the tool rotates, feed is measured in inches per revolution. When the tool or the work reciprocates, feed is measured in inches per stroke, Generally, feed varies inversely with cutting speed for otherwise similar conditions.The depth of cut, measured inches is the distance the tool is set into the work. It is the width of the chip in turning or the thickness of the chip in a rectilinear cut. In roughing operations, the depth of cut can be larger than for finishing operations.The Effect of Changes in Cutting Parameters on Cutting TemperaturesIn metal cutting operations heat is generated in the primary and secondary deformation zones and these results in a complex temperature distribution throughout the tool, workpiece and chip. A typical set of isotherms is shown in figure where it can be seen that, as could be expected, there is a very large temperature gradient throughout the width of the chip as the workpiece material is sheared in primary deformation and there is a further large temperature in the chip adjacent to the face as the chip is sheared in secondary deformation. This leads to a maximum cutting temperature a short distance up the face from the cutting edge and a small distance into the chip.Since virtually all the work done in metal cutting is converted into heat, it could be expected that factors which increase the power consumed per unit volume of metal removed will increase the cutting temperature. Thus an increase in the rake angle, all other parameters remaining constant, will reduce the power per unit volume of metal removed and the cutting temperatures will reduce. When considering increase in unreformed chip thickness and cutting speed the situation is more complex. An increase in undeformed chip thicknesstends to be a scale effect where the amounts of heat which pass to the workpiece, the tool and chip remain in fixed proportions and the changes in cutting temperature tend to be small. Increase in cutting speed; however, reduce the amount of heat which passes into the workpiece and this increase the temperature rise of the chip m primary deformation. Further, the secondary deformation zone tends to be smaller and this has the effect of increasing the temperatures in this zone. Other changes in cutting parameters have virtually no effect on the power consumed per unit volume of metal removed and consequently have virtually no effect on the cutting temperatures. Since it has been shown that even small changes in cutting temperature have a significant effect on tool wear rate it is appropriate to indicate how cutting temperatures can be assessed from cutting data.The most direct and accurate method for measuring temperatures in high -speed-steel cutting tools is that of Wright &. Trent which also yields detailed information on temperature distributions in high-speed-steel cutting tools. The technique is based on the metallographic examination of sectioned high-speed-steel tools which relates microstructure changes to thermal history.Trent has described measurements of cutting temperatures and temperature distributions for high-speed-steel tools when machining a wide range of workpiece materials. This technique has been further developed by using scanning electron microscopy to study fine-scale microstructure changes arising from over tempering of the tempered martens tic matrix of various high-speed-steels. This technique has also been used to study temperature distributions in both high-speed -steel single point turning tools and twist drills.Wears of Cutting ToolDiscounting brittle fracture and edge chipping, which have already been dealt with, tool wear is basically of three types. Flank wear, crater wear, and notch wear. Flank wear occurs on both the major and the minor cutting edges. On the major cutting edge, which is responsible for bulk metal removal, these results in increased cutting forces and higher temperatures which if left unchecked can lead to vibration of the tool and workpiece and a condition where efficient cutting can no longer take place. On the minor cutting edge, which determines workpiece size and surface finish, flank wear can result in an over sized product which has poor surface finish. Under most practical cutting conditions, the tool will fail due to major flank wear before the minor flank wear is sufficiently large to result in the manufacture of an unacceptable component.Because of the stress distribution on the tool face, the frictional stress in the region of sliding contact between the chip and the face is at a maximum at the start of the sliding contact region and is zero at the end. Thus abrasive wear takes place in this region with more wear taking place adjacent to the seizure region than adjacent to the point at which the chip loses contact with the face. This result in localized pitting of the tool face some distance up the face which is usually referred to as catering and which normally has a section in the form of a circular arc. In many respects and for practical cutting conditions, crater wear is a less severe form of wear than flank wear and consequently flank wear is a more common tool failure criterion. However, since various authors have shown that the temperature on the face increases more rapidly with increasing cutting speed than the temperature on the flank, and since the rate of wear of any type is significantly affected by changes in temperature, crater wear usually occurs at high cutting speeds.At the end of the major flank wear land where the tool is in contact with the uncut workpiece surface it is common for the flank wear to be more pronounced than along the rest of the wear land. This is because of localised effects such as a hardened layer on the uncut surface caused by work hardening introduced by a previous cut, an oxide scale, and localised high temperatures resulting from the edge effect. This localised wear is usually referred to as notch wear and occasionally is very severe. Although the presence of the notch will not significantly affect the cutting properties of the tool, the notch is often relatively deep and if cutting were to continue there would be a good chance that the tool would fracture.If any form of progressive wear allowed to continue, dramatically and the tool would fail catastrophically, i. e. the tool would be no longer capable of cutting and, at best, the workpiece would be scrapped whilst, at worst, damage could be caused to the machine tool. For carbide cutting tools and for all types of wear, the tool is said to have reached the end of its useful life long before the onset of catastrophic failure. For high-speed-steel cutting tools, however, where the wear tends to be non-uniform it has been found that the most meaningful and reproducible results can be obtained when the wear is allowed to continue to the onset ofcatastrophic failure even though, of course, in practice a cutting time far less than that to failure would be used. The onset of catastrophic failure is characterized by one of several phenomena, the most common being a sudden increase in cutting force, the presence of burnished rings on the workpiece, and a significant increase in the noise level.Mechanism of Surface Finish ProductionThere are basically five mechanisms which contribute to the production of a surface which have been machined. These are:(l) The basic geometry of the cutting process. In, for example, single point turning the tool will advance a constant distance axially per revolution of the work price and the resultant surface will have on it, when viewed perpendicularly to the direction of tool feed motion, a series of cusps which will have a basic form which replicates the shape of the tool in cut.(2) The efficiency of the cutting operation. It has already been mentioned that cutting with unstable built-up-edges will produce a surface which contains hard built-up-edge fragments which will result in a degradation of the surface finish. It can also be demonstrated that cutting under adverse conditions such as apply when using large feeds small rake angles and low cutting speeds, besides producing conditions which lead to unstable built-up-edge production, the cutting process itself can become unstable and instead of continuous shear occurring in the shear zone, tearing takes place, discontinuous chips of uneven thickness are produced, and the resultant surface is poor. This situation is particularly noticeable when machining very ductile materials such as copper and aluminum.(3) The stability of the machine tool. Under some combinations of cutting conditions; workpiece size, method of clamping ,and cutting tool rigidity relative to the machine tool structure, instability can be set up in the tool which causes it to vibrate. Under some conditions this vibration will reach and maintain steady amplitude whilst under other conditions the vibration will built up and unless cutting is stopped considerable damage to both the cutting tool and workpiece may occur. This phenomenon is known as chatter and in axial turning is characterized by long pitch helical bands on the workpiece surface and short pitch undulations on the transient machined surface.(4)The effectiveness of removing swarf. In discontinuous chip production machining, such as milling or turning of brittle materials, it is expected that the chip (swarf) will leave the cutting zone either under gravity or with the assistance of a jet of cutting fluid and that they will not influence the cut surface in any way. However, when continuous chip production is evident, unless steps are taken to control the swarf it is likely that it will impinge on the cut surface and mark it. Inevitably, this marking besides looking.(5)The effective clearance angle on the cutting tool. For certain geometries of minor cutting edge relief and clearance angles it is possible to cut on the major cutting edge and burnish on the minor cutting edge. This can produce a good surface finish but, of course, it is strictly a combination of metal cutting and metal forming and is not to be recommended as a practical cutting method. However, due to cutting tool wear, these conditions occasionally arise and lead to a marked change in the surface characteristics.Limits and TolerancesMachine parts are manufactured so they are interchangeable. In other words, each part of a machine or mechanism is made to a certain size and shape so will fit into any other machine or mechanism of the same type. To make the part interchangeable, each individual part must be made to a size that will fit the mating part in the correct way. It is not only impossible, but also impractical to make many parts to an exact size. This is because machines are not perfect, and the tools become worn. A slight variation from the exact size is always allowed. The amount of this variation depends on the kind of part being manufactured. For examples part might be made 6 in. long with a variation allowed of 0.003 (three-thousandths) in. above and below this size. Therefore, the part could be 5.997 to 6.003 in. and still be the correct size. These are known as the limits. The difference between upper and lower limits is called the tolerance.A tolerance is the total permissible variation in the size of a part.The basic size is that size from which limits of size arc derived by the application of allowances and tolerances.Sometimes the limit is allowed in only one direction. This is known as unilateral tolerance.Unilateral to learning is a system of dimensioning where the tolerance (that is variation) is shown in only one direction from the nominal size. Unilateral to learning allow the changing of tolerance on a hole or shaft without seriously affecting the fit.When the tolerance is in both directions from the basic size it is known as a bilateral tolerance (plus and minus).Bilateral to learning is a system of dimensioning where the tolerance (that is variation) is split and is shown on either side of the nominal size. Limit dimensioning is a system of dimensioning where only the maximum and minimum dimensions arc shown. Thus, the tolerance is the difference between these two dimensions.Surface Finishing and Dimensional ControlProducts that have been completed to their proper shape and size frequently require some type of surface finishing to enable them to satisfactorily fulfill their function. In some cases, it is necessary to improve the physical properties of the surface material for resistance to penetration or abrasion. In many manufacturing processes, the product surface is left with dirt .chips, grease, or other harmful material upon it. Assemblies that are made of different materials, or from the same materials processed in different manners, may require some special surface treatment to provide uniformity of appearance.Surface finishing may sometimes become an intermediate step processing. For instance, cleaning and polishing are usually essential before any kind of plating process. Some of the cleaning procedures are also used for improving surface smoothness on mating parts and for removing burrs and sharp corners, which might be harmful in later use. Another important need for surface finishing is for corrosion protection in a variety of: environments. The type of protection procedure will depend largely upon the anticipated exposure, with due consideration to the material being protected and the economic factors involved.Satisfying the above objectives necessitates the use of main surface-finishing methods that involve chemical change of the surface mechanical work affecting surface properties, cleaning by a variety of methods, and the application of protective coatings, organic and metallic.In the early days of engineering, the mating of parts was achieved by machining one part as nearly as possible to the required size, machining the mating part nearly to size, and then completing its machining, continually offering the other part to it, until the desired relationship was obtained. If it was inconvenient to offer one part to the other part during machining, the final work was done at the bench by a fitter, who scraped the mating parts until the desired fit was obtained, the fitter therefore being a 'fitter' in the literal sense. J It is obvious that the two parts would have to remain together, and m the event of one having to be replaced, the fitting would have to be done all over again. In these days, we expect to be able to purchase a replacement for a broken part, and for it to function correctly without the need for scraping and other fitting operations.When one part can be used 'off the shelf' to replace another of the same dimension and material specification, the parts are said to be interchangeable. A system of interchangeability usually lowers the production costs as there is no need for an expensive, 'fiddling' operation, and it benefits the customer in the event of the need to replace worn parts.Automatic Fixture DesignTraditional synchronous grippers for assembly equipment move parts to the gripper center-line, assuring that the parts will be in a known position after they arc picked from a conveyor or nest. However, in some applications, forcing the part to the center-line may damage cither the part or equipment. When the part is delicate and a small collision can result in scrap, when its location is fixed by a machine spindle , or when tolerances are tight, it is preferable to make a gripper comply with the position of the part, rather than the other way around. For these tasks, zaytran Inc. Of Elyria, Ohio, has created the GPN series of non- synchronous, compliant grippers. Because the force and synchronizations systems of the grippers are independent, the synchronization system can be replaced by a precision slide system without affecting gripper force. Gripper sizes range from 51b gripping force and 0.2 in. stroke to 40Glb gripping force and 6in stroke. Grippers。
曲轴的加工工艺及夹具设计外文翻译
毕业设计外文翻译题目曲轴的加工工艺及夹具设计学院航海学院专业轮机工程学生佟宝诚学号********指导教师彭中波重庆交通大学2014年Proceedings of IMECE20082008 ASME International Mechanical Engineering Congress and ExpositionOctober 31-November 6, 2008, Boston, Massachusetts, USAIMECE2008-67447MULTI-OBJECTIVE SYSTEM OPTIMIZATION OF ENGINE CRANKSHAFTS USINGAN INTEGRATION APPROACHAlbert Albers/IPEK Institute of Product DevelopmentUniversity of Karlsruhe GermanyNoel Leon/CIDyT Center for Innovation andDesignMonterrey Institute of Technology,MexicoHumberto Aguayo/CIDyT Center forInnovation and Design,Monterrey Institute ofTechnology, MexicoThomas Maier/IPEK Institute of Product DevelopmentUniversity of Karlsruhe GermanyABSTRACTThe ever increasing computer capabilities allow faster analysis in the field of Computer Aided Design and Engineering (CAD & CAE). CAD and CAE systems are currently used in Parametric and Structural Optimization to find optimal topologies and shapes of given parts under certain conditions. This paper describes a general strategy to optimize the balance of a crankshaft, using CAD and CAE software integrated with Genetic Algorithms (GAs) via programming in Java. An introduction to the groundings of this strategy is made among different tools used for its implementation. The analyzed crankshaft is modeled in commercial parametric 3D CAD software. CAD is used for evaluating the fitness function (the balance) and to make geometric modifications. CAE is used for evaluating dynamic restrictions (the eigenfrequencies). A Java interface is programmed to link the CAD model to the CAE software and to the genetic algorithms. In order to make geometry modifications toour case study, it was decided to substitute the profile of the counterweights with splines from its original “arc-shaped” design. The variation of the splined profile via control points results in an imbalanceresponse. The imbalance of the crankshaft was defined as an independent objective function during a first approach, followed by a Pareto optimization of the imbalance from both correction planes, plus the curvature of the profile of the counterweights as restrictions for material flow during forging. The natural frequency was considered as an additional objective function during a second approach. The optimization process runs fully automated and the CAD program is on hold waiting for new set of parameters to receive and process, saving computing time, which is otherwise lost during the repeated startup of the cad application.The development of engine crankshafts is subject to a continuous evolution due to market pressures. Fast market developments push the increase of power, fuel economy, durability and reliability of combustion engines, and calls for reduction of size, weight, vibration and noise, cost, etc. Optimized engine components are therefore required if competitive designs must be attained. Due to this conditions, crankshafts, which are one of the most analyzed engine components, are required to be improved [1]. One of these improvements relies on material composition, as companies that develop combustion engines have expressed their intentions to change actual nodular steel crankshafts from their engines, to forged steel crankshafts. Another important direction of improvement is the optimization of its geometrical characteristics. In particular for this paper is the imbalance, first Eigen-frequency and the forge-ability. Analytical tools can greatly enhance the understanding of the physical phenomena associated with the mentioned characteristics and can be automated to do programmed tasks that an engineer requires for optimizing a design [2].The goals of the present research are: to construct a strategy for the development of engine crankshafts based on the integration of: CAD and CAE (Computer Aided Design &Engineering) software to model and evaluate functionalparameters, Genetic Algorithms as the optimization method, the use of splines for shape construction and Java language programming for integration of the systems. Structural optimization under these conditions allows computers to work in anautomated environment and the designer to speed up and improve the traditional design process. The specific requirements to be satisfied by the strategies are: Approach the target of imbalance of a V6 engine crankshaft, without affecting either its weight or itsmanufacturability.Develop interface programming that allows integration of the different software: CAD for modeling and geometric evaluations, CAE for simulation analysis and evaluation ,Genetic Algorithms for optimization and search for alternatives .Obtain new design concepts for the shape of the counterweights that help the designer to develop a better crankshaft in terms of functionality more rapidly than with the use of a “manual” approachShape optimization with genetic algorithmsGenetic Algorithms (GAs) are adaptive heuristic search algorithms (stochastic search techniques) based on the ideas of evolutionary natural selection and genetics [3]. Shape optimization based on genetic algorithm (GA), or based on evolutionary algorithms (EA) in general, is a relatively new area of research. The foundations of GAs can be found in a few articles published before 1990 [4]. After 1995 a large number of articles about investigation and applications have been published, including a great amount of GA-based geometrical boundary shape optimization cases. The interest towards research in evolutionary shape optimization techniques has just started to grow, including one of the most promising areas for EA-based shape optimization applications: mechanical engineering. There are applications for shape determination during design of machine components and for optimization of functional performance of these the components, e.g. antennas [5], turbine blades [6], etc. In the ield of mechanical engineering, methods for structural and topological optimization based on evolutionary algorithms are used to obtain optimal geometric solutions that were commonly approached only by costly and time consuming iterative process. Some examples are the computer design and optimization of cam shapes for diesel engines [7]. In this case the objective of the cam design was to minimize the vibrations of the system and to make smooth changes to a splined profile.In this article the shape optimization of a crankshaft is discussed, with focus on the geometrical development of the counterweights. The GAs are integrated with CAD and CAE systems that are currently used in Parametric and Structural Optimization to find optimal topologies and shapes of givenparts under certain conditions. Advanced CAD and CAE software have their own optimization capabilities, but are often limited to some local search algorithms, so it is decided to use genetic algorithms, such as those integrated in DAKOTA (Design Analysis Kit for Optimization Applications) [8] developed at Sandia Laboratories. DAKOTA is an optimization framework with the original goal ofproviding a common set of optimization algorithms for engineers who need to solve structural and design problems, including Genetic Algorithms. In order to make such integration, it is necessary to develop an interface to link the GAs to the CAD models and to the CAE analysis. This paper presents an approach to this task an also some approaches that can be used to build up a strategy on crankshaft design anddevelopment.Multi-objective considerations of crankshaft performanceThe crankshaft can be considered an element from where different objective functions can be derived to form an optimization problem. They represent functionalities and restrictions that are analyzed with software tools during the design process. These objective function are to be optimized (minimized or maximized) by variation of the geometry. The selected goal of the crankshaft design is to reach the imbalance target and reducing its weight and/or increasing its first eigenfrequency. The design of the crankshaft is inherently a multiobjective optimization (MO) problem. The imbalance is measured in both sides of the crankshaft so the problem is to optimize the components of a vector-valued objective function consisting of both imbalances [9]. Unlike the single-objective optimization, the solution to this problem is not a single point, but a family of points known as the Pareto-optimal set. Each point in this set is optimal in the sense that no improvement can be achieved in one objective component that does not lead to degradation in at least one of the remaining components [10].The objective functions of imbalance are also highly nonlinear. Auxiliaryinformation, like the derivatives of the objective function, is not available. The fitness-function is available only in the form of a computer model of the crankshaft, not in analytical form. Since in general our approach requires taking the objective function as a black box, and only the availability of the objective function value can be guaranteed, no further assumptions were considered. The Pareto-based optimization method, known as the Multiple Objective Genetic Algorithm (MOGA) [11], is used in the present MO problem, to finding the Pareto front among these two fitness functions.In GA’s, the natural parameter se t of the optimization problem is coded as afinite-length string. Traditionally, GA’s use binary numbers to represent such strings: a string has a finite length and each bit of a string can be either 0 or 1. By maintaining a population of solutions, GA’s c an search for many Pareto-optimal solutions in parallel. This characteristic makes GA’s very attractive for solving MO problems. The following two features are desired to solve MO problems successfully:1) the solutions obtained are Pareto-optimal and2) they are uniformly sampled from the Pareto-optimal set.NOMENCLATURECAD: Computer Aided Design; GAs: Genetic Algorithms; EA: Evolutionary Algorithms; MO: Multi-objective; MOGA: Multi-objective Genetic Algorithm; CW: Counterweight; FEM: Finite Element Method.OPTIMIZATION OF BALANCE WITH GEOMETRICALFig. 1: Imbalance graph from the original crankshaft DesignCrankshaft shape parameterizationIn order to make geometry modifications it is decided to substitute the current shape design of the crankshaft under analysis, from the original “arc-shaped” design representation of the counterweight’s profile, to a profile using spline curvesThe figure 2 shows a counterweight profile of the crankshaft.Fig. 2: Profile of a counterweight represented by a splineOptimization StrategiesThe general procedure of the strategy is described below. During the optimization loop the CAD software is automatically controlled by an optimization algorithm, i.e. by a Genetic Algorithms (GA). The y coordinates of the control points that define the splined profile of the crankshaft can be parametrically manipulated thanks to an interface programmed in JAVA. The splined profiles allow shapes to be changed by genetic algorithms because the codified control points of the splines play the role of genes. The Java interface allows the CAD software to run continually with the crankshaft model loaded in the computer memory, so that every time an individual is generated the geometry automatically adapts to the new set of parameters.Fig. 3: Profile Shapes of CW1, CW2, CW8 and CW9 from an individual in the Pareto FrontierA corresponding constraint to the optimization strategy is formulated next. An additional objective function was added: the measure of the curvature of all the splines from the profiles of counterweights. As it is known, the curvature is theinverse of the radius of an inscribed circle of the curve. In this case it was decided to integrate into the geometry the required inscribed circles and analysis features to extract the maximum curvature along the profiles of the four varyingFig. 4: Curvature in CW9 profile showing an improvedCurvatureIn the second part of this paper an additional evaluation is going to be introduced: the dynamic response of the crankshaft in order to control the first eigen frequency, with the aim of not affecting the weight. As in this first approach, the GA is going to be used to produce automatically alternative crankshaft shapes for the FEM simulator program, to run the simulator, and finally to e valuate the counterweight’s shapes on the basis of the FEM output data.SUMMARY AND CONCLUSIONSThe use of the Java interface allowed the integration of the genetic algorithm to the CAD software, in the first part of the paper, an optimization of the imbalance of a crankshaft was performed. It was possible the development of a Pareto frontier to find the closest-to-target individual. But the shapes of the counterweights were not so suitable for forging, for that reason it was necessary to introduce an additional objective function to improve the curvature of the counterweights profile. A further integration with the CAE software, as described in the second part, was performed. It was possible to improve some shapes of the crankshaft but with not so good imbalance results. The development of a new graph with the additional firsteigen-frequency objective was plotted, from which important conclusions were extracted: It is necessary to prevent the sharp edges of the counterweight’s shape byadding extra restrictions as curvature of shapes.Simulation of the forging process is required in order to define a relationship between good shapes-curvature and manufacturability. This becomes significantly important when a proposed design outside the initial shape restrictions needs to be justified in order not to affect forge ability.This paper defined the basis and the beginning of a strategy for developing crankshafts that will include the manufacturability and functionality to compile a whole Multiobjective System Optimization.ACKNOWLEDGMENTSThe authors acknowledge the support received from Tecnológico de Monterrey through Grant No. CAT043 to carry out the research reported in this paper.REFERENCES[1] Z.P. Mourelatos, “A crankshaft system model for structural dynamic analysis of internal combustion engines,” Computers & Structures, vol. 79, 2001, pp.2009-2027.[2] P. Bentley, Evolutionary Design by Computers, USA:Morgan Kaufmann, 1999.[3] D.E. Goldberg, Genetic Algorithms in Search ,Optimization and Machine Learning, USA: Addison-Wesley Longman Publishing Co., 1989.[4] C.A. Coello Coello, “A Comprehensive Survey of Evolutionary-Based Multi-objective Optimization Techniques,” Knowledge and Information Systems, vol.1, 1999, pp. 129-156.[5] B.E. Cohanim, J.N. Hew itt, and O. de Weck, “TheDesign of Radio Telescope Array Configurations using Multiobjective Optimization: Imaging Performance versus Cable Length,” astro-ph/0405183, 2004, pp. 1-42;[6] M. Olhofer, Yaochu Jin, and B. Sendh off, “Adaptiveen coding for aerodynamic shape optimization using evolution strategies,” Evolutionary Computation, Seoul: 2001, pp. 576-583.[7] J. Lampinen, “Cam shape optimization by genetical gorithm,” Computer-Aided Design, vol. 35, 2003, pp.727-737.[8] M. Eldred et al., DAKOTA, A Multilevel ParallelObject-Oriented Framework for Design Optimization, Parameter Estimation, Uncertainty Quantification, andSensitivity Analysis. Reference Manual, USA: Sandia Laboratories, 2002.[9] Y. Kang et al., “An accuracy improvement for balanci ng crankshafts,” Mechanism andMachine Theory, vol. 38,2003, pp. 1449-1467.[10] S. Obayashi, T. Tsukahara, and T. Nakamura,“Multiobjective genetic algorithm applied toaerodynamic design of cascade airfoils,” Industrial Electronics, IEEE Transactions on, vol. 47, 2000, pp.211-216.[11] C.M. Fonseca and P.J. Fleming, “An Overview of Evolutionary Algorithms in Multiobjective Optimization,” Evolutionary Computation, vol. 3, 1995,pp. 1-16[12] - ., “Comparison of Strategies forthe Optimization/Innovation o f Crankshaft Balance,”T rends in Computer Aided Innovation, USA: Springer,2007, pp. 201-210.[13] S. Rao, M echanical vibrations, USA: Addison-Wesley,1990.[14] C.A. Coello Coello, A n empirical study of evolutionary techniques for multi-objective optimization in engineering design, USA: Tulane University, 1996.[15] N. Leon-Rovira et al., “Automatic Shape Variations in3d CAD Environments,” 1st IFIP-TC5 Working Conference on Computer Aided Innovation, Germany:2005, pp. 200-210.[16] R.E. Smith, B.A. Dike, and S.A. Stegmann, “Fitness inheritance in genetic algorithms,”A CM symposium on Applied computing, USA: ACM, 1995, pp. 345-350.IMECE2008学报2008年ASME国际机械工程国会和博览会2008年10月31-11月6日，波斯顿，马赛诸塞州，美国IMECE2008-67447适用于多目标系统优化发动机曲轴（阿尔伯特·阿尔伯斯/ IPEK产品开发研究所，德国卡尔斯鲁厄大学；诺埃尔利昂/ CIDyT创新中心和设计，墨西哥蒙特雷理工学院；温贝托Aguayo / CIDyT创新中心和设计，墨西哥蒙特雷理工学院；托马斯•迈尔/ IPEK产品开发研究所，德国卡尔斯鲁厄大学）随着计算机的功能不断增加，计算机辅助设计与工程(CAD和CAE)也不断加强。
中英文文献翻译-曲轴的工作条件和设计要求
附录Crankshaft design requirements andworking conditionsCrankshaft is in constant cyclical changes in the gas pressure, reciprocating and rotating motion of the inertial force and the quality of their work under the joint action of the moment, so that both the torsion and bending the crankshaft, resulting in fatigue, stress state; internal imbalance of the engine crankshaft also withstand bending moment and shear force; not taken measures to make the crankshaft torsional vibration damping effect may also be a large amplitude torsional elastic torque. These loads are cross degeneration, may cause fatigue failure of the crankshaft. Practice shows that the bending has a decisive role in bending fatigue failure is the main failure modes. Therefore, the structural strength of the crankshaft bending fatigue strength is the focus, the crankshaft is designed to be committed to improving the fatigue strength of the crankshaft.Crankshaft complex shape, stress concentration is very serious, especially in the connecting rod journal and the crank arm of the fillet and lubricants at the stress concentration near the exit hole is particularly prominent. Common crankshaft fracture, fatigue crack begins with fillet and the hole place. Figure 7-1 shows the crankshaft bending fatigue and fatigue failure of the reverse situation. Root bending fatigue cracks in the surface of the fillet from the journal at the development of the crank, the crank is basically broken into 450; torsion fatigue damage is usually bad from the machining start hole edge, about 450 cut into the crank pin. Therefore, in the design of the crankshaft, pay special attention to finding ways to ease stress concentration, strengthen the stress concentration.Crankshaft journal at a very high ratio of pressure to a large relative velocity of sliding friction in the bearings in place. The bearings in the actual operation conditions changed conditions does not always guarantee a liquid friction, especially when the oil is not clean, the journal was a strong abrasive wear surface, making the actual life of the crankshaft greatly reduced. Therefore, the design, to wear to the friction surface, and the appropriate material bearing a good match.Crank in the crankshaft is the central link, the stiffness is very important. If the crankshaft bending stiffness, then the possible occurrence of more severe bending, the piston rod and bearing deterioration in working conditions greatly affect the reliability of these parts work and durability, even the crankcase is too large and the local stress cracking. Crankshaft's torsional stiffness is poor, the working speed range may be a strong torsional vibration. Ranging from noise, such as transmission gear on the crank to accelerate the wear; while in the crankshaft fracture. Therefore, the design should ensure it has the highest possible bending stiffness and torsional stiffness.As the crankshaft by the power complex, geometric cross-section shape is rather special, in the design, has yet to reflect the objective reality of a theoretical formula for Universal.Therefore, the current design of the crankshaft design relies mainly on experience.曲轴的工作条件和设计要求曲轴是在不断周期性变化的气体压力、往复和旋转运动质量的惯性力以及它们的力矩共同作用下工作的，从而使曲轴既扭转又弯曲，产生疲劳应力状态；对内不平衡的发动机曲轴还承受内弯矩和剪力；未采取扭转振动减振措施使曲轴还可能作用着幅值较大的扭转振动弹性力矩。
曲轴加工的技术要求及发展方向外文翻译
外文资料The crank processes specification anddevelopment directionThe crank processes specificationThe crank specification is very high, its machine-finishing technological process different and the crank complex degree has the very big difference along with the production guiding principle, but includes following several main stages generally: Localization datum processing; Thick, lathe finishing and rough grinding each host neck and other outer annuluses; Che Lianjing; Drills the oil hole; Correct grinding each host neck and other outer annuluses; Correct grinding Lian Jing; Big, capitellum and key slot processing; Journal surface treatment; Transient equilibrium; Super finishing various journals.May see, the main neck or Lian Jing the turning working procedure all separates with the grinding working procedure, is often middle arrangement some different machined surfaces or the heterogeneity working procedure. After the rough machining can have the distortion, therefore the normal force reduces gradually; Because simultaneously thick, the precision work working procedure carries on separately before, the latter working procedure has the possibility to eliminate the working procedure error, finally obtains the very high precision and the very low roughness. Thick, the precision work separates, and arranges the alignment working procedure behind the cutting force big working procedure, guarantees the processing precision.In order to reduce the distortion which the cutting force causes, guaranteed when precision work precision request, correct grinding various journals, uses the single grinding wheel in turn grinding generally.The journal processing requests high, the main neck and the neck uses continually processes many times.Crank machining development directionAlong with our country numerical control engine bed unceasing increase, the crank rough machining will be widespread uses in the numerical control lathe, the numerical control the milling machine, the numerical control vehicle broaching machine and so on the advanced equipment to the main journal, the connecting rod journal carries on the numerical control turning, in the milling, the vehicle - broaching processing, by will effectively reduce the amount of deformity which the crank willprocess. The crank precision work will be widespread uses the CNC control the crankshaft grinding to carry on the correct grinding processing to its journal, this kind of grinder will provide grinding wheel automatic function requests and so on transient equilibrium installment, center rest automatic tracking unit, automatic survey, self-compensating system, grinding wheel automatic conditioning, permanent link speed, will guarantee the grinding quality the stability.In order to satisfy the processing request which the crank enhances day by day, set the very high request to the crankshaft grinding. The modern crankshaft grinding except must have the very high static state, the dynamic rigidity and outside the very high processing precision, but also requests to have the very high grinding efficiency and more flexibilities. In recent years, requested the crankshaft grinding to have the stable processing precision, for this, had stipulated to the crankshaft grinding process capability coefficient Cp≥1.67, this meant reques ted the crankshaft grinding the actual processing common difference to have the common difference which assigned compared to the crank small one half. Along with the modern actuation and the control technology, the survey control, CBN (cubic boron nitride) the grinding wheel and the advanced engine bed part application, for the crankshaft grinding high accuracy, the highly effective abrasive machining has created the condition. One kind calls it the connecting rod neck follow-up grinding craft. Has manifested these new technical synthesis application concrete achievement. This kind of follow-up grinding craft may obviously enhance the crank connecting rod neck the grinding efficiency, the processing precision and the processing flexibility. When carries on the follow-up grinding to the connecting rod neck, the crank take the main journal as the spool thread carries on revolving, and clamps the grinding all connecting rod neck in an attire. In the grinding process, the wheelhead realization reciprocation swing feed, tracks the biased rotation connecting rod neck to carry on the abrasive machining. Must realize the follow-up grinding, X axis besides must have the high dynamic performance, but also must have the enough tracking accuracy, guarantees the shape common difference which the connecting rod neck requests. The CBN grinding wheel application realizes the connecting rod neck follow-up grinding important condition. Because the CBN grinding wheel resistance to wear is high, in the grinding process medium plain emery wheel diameter is nearly invariable, a conditioning may the grinding 600~800 cranks. The CBN grinding wheel also may use the very high grinding speed, may use generally on the crankshaft grinding reaches as high as the120~140m/s grinding speed, the grinding efficiency is very high.Connecting rod processing and trend of development Connecting rod processing methodThe connecting rod decomposes (also called connecting rod breaks) the technical principle uses the material break theory, first artificial has the whole forging connecting rod semi finished materials big end of hole the fissure, forms the initial break source, then expands with the specific method control fissure, achieved the connecting rod The decomposition processing process enable the decomposition the connecting rod cap, the pole adjoining plane to have the complete meshing jig-saw patterned structure, guaranteed the adjoining plane precise docking, tallies, does not need to carry on the adjoining plane again the processing, simultaneously simplified the connecting rod bolt hole structural design and the whole processing craft, has the processing working procedure few, the economical precision work equipment, the nodal wood energy conservation, the product quality high, the production cost low status merit. Main body and the connecting rod cap separate goal.Trend of developmentAt present, the drop for and the die casting connecting rod host, the important status, are facing the powder to forge the steel connecting rod and a powder agglutination steel connecting rod forming craft challenge. Speaking of the domestic present situation, although the powder metallurgy forging industry had certain development, but must provide the mass and the high grade powder metallurgy forging is not mature. Moreover involves the equipment to renew, aspect expense questions and so on technical change, in next one, in long time, domestically produced connecting rod production also by drop forging craft primarily.The connecting rod is one of internal combustion engine main spare parts, its reducing socket two sizes and the shape position errors have many requests, for example: Diameter, roundness, cylindricity, center distance, parallelism, hole and end surface verticality and so on. How does these erroneous project produce the scene in the workshop to examine, always is in the internal combustion engine profession a quite difficult question.In the connecting rod production, domestic mainly has following several examination method at present: With the spindle survey, namely puts on the spindle in connecting rod two, with the aid of in V shape block, plate, dial guage survey.Because the spindle needs to load and unload, therefore between the hole axis has the gap, the measuring accuracy is very low.中文翻译曲轴加工的技术要求及发展方向曲轴加工的技术要求曲轴的技术要求是很高的，其机械加工工艺过程随生产纲领的不同和曲轴的复杂程度而有很大的区别，但一般均包括以下几个主要阶段：定位基准的加工；粗、精车和粗磨各主颈及其它外圆；车连颈；钻油孔；精磨各主颈及其他外圆；精磨连颈；大、小头及键槽加工；轴颈表面处理；动平衡；超精加工各轴颈。
轴类加工工艺外文翻译、中英文翻译、外文文献翻译
ShaftSolid shafts. As a machine component a shaft is commonly a cylindrical bar that supports and rotates with devices for receiving and delivering rotary motion and torque .The crankshaft of a reciprocating engine receive its rotary motion from each of the cranks, via the pistons and connecting roads (the slider-crank mechanisms), and delivers it by means of couplings, gears, chains or belts to the transmission, camshaft, pumps, and other devices. The camshafts, driven by a gear or chain from the crankshaft, has only one receiver or input, but each cam on the shaft delivers rotary motion to the valve-actuating mechanisms.An axle is usually defined as a stationary cylindrical member on which wheels and pulleys can rotate, but the rotating shafts that drive the rear wheels of an automobile are also called axles, no doubt a carryover from horse-and-buggy days. It is common practice to speak short shafts on machines as spindles, especially tool-carrying or work-carrying shafts on machine tools.In the days when all machines in a shop were driven by one large electric motor or prime mover, it was necessary to have long line shafts running length of the shop and supplying power, by belt, to shorter couter shafts, jack shafts, or head shafts. These lineshafts were assembled form separate lengths of shafting clampled together by rigid couplings. Although it is usually more convenient to drive each machine with a separate electric motor, and the present-day trend is in this direction, there are still some oil engine receives its rotary motion from each of the cranks, via the pistons and connecting roads (the slider-crank mechanisms) , and delivers it by means of couplings, gears, chains or belts to the transmission, camshaft, pumps, and other devices. The camshafts, driven by a gear or chain from the crankshaft, has only one receiver or input, but each cam on the shaft delivers rotary motion to the valve-actuating mechanisms.An axle is usually defined as a stationary cylindrical member on which wheels and pulleys can rotate, but the rotating shafts that drive the rear wheels of an automobile are also called axles, no doubt a carryover from horse-and-buggy days. It is common practice to speak short shafts on machines as spindles, especially tool-carrying or work-carrying shafts on machine tools.In the days when all machines in a shop were driven by one large electric motor or prime mover, it was necessary to have long line shafts running length of the shop and supplying power, by belt, to shorter coutershafts, jackshafts, or headshafts. These line shafts were assembled form separatelengths of shafting clampled together by rigid couplings. Although it is usually more convenient to drive each machine with a separate electric motor, and the present-day trend is in this direction, there are still some situation in which a group drive is more economical.A single-throw crankshaft that could be used in a single-cylinder reciprocating engine or pump is shown in Figure 21. The journals A andB rotate in the main bearings,C is the crankpin that fits in a bearing on the end of the connecting rod and moves on a circle of radius R about the main bearings, whileD andE are the cheeks or webs.The throw R is one half the stroks of the piston, which is connected, by the wrist pin, to the other end of the connecting rod and guided so as to move on a straight path passing throw the axis XX. On a multiple-cylinder engine the crankshaft has multiple throws---eight for a straight eight and for a V-8---arranged in a suitable angular relationship.Stress and strains. In operation, shafts are subjected to a shearing stress, whose magnitude depends on the torque and the dimensions of the cross section. This stress is a measure of resistance that the shaft material offers to the applied torque. All shafts that transmit a torque are subjected to torsional shearing stresses.In addition to the shearing stresses, twisted shafts are also subjected to shearing distortions. The distorted state is usually defined by the angle of twist per unit length; i.e., the retation of one cross section of a shaft relative to another cross section at a unit distance from it.Shafts that carry gears and pulleys are bent as well as twisted, and the magniude of the bending stresses, which are tensile on the convex side of the bend and compressive on the concave side, will depend on the load, the distance between the bearings of the shaft cross section.The combination of bending and twisting produces a state of stress in the shaft that is more complex than the state of pure shears produced by torsion alone or the state of tension-compression produced by bending alone.To the designer of shaft it is important to know if the shaft is likely to fail because of an excessive normal stress. If a piece of chalk is twisted, it will invariably rupture on a plane at about 45 degrees to the axis. This is because the maximum tensile stresses act on this plane, and chalk is weak in tension. Steel shafting is usually designed so that the maximum shearing stress produced by bending and torsion is less than a specified maximum.Shafts with circular cross sections are easier to produce in the steel mill, easier to machine, andeasier to support in bearings than shafts with other cross section; there is seldom any need for using noncircular shapes. In addition, the strength and stiffness, both in bending and torsion, are more easily calculated for circular shafts. Lastly, for a given amount of materials the circular shafts has the smallest maximum shearing stress for a given torque, and the highest torsional rigidity.The shearing in a circular shaft is highest at the surface and drops off to zero at the axis. This means that most of the torque is carried by the material on and near the surface.Critical speeds. In the same way that a violin string vibrates when stroked with a bow, a cylindrical shaft suspended between two bearings has a natural frequency of lateral vibration. If the speed of revolution of the shaft coincides with the natural frequency, the shaft experience a whirling critical speed and become noisy. These speeds are more likely to occur with long, flexible shafts than with short, stiff ones. The natural frequency of a shaft can be raised by increasing its stiffness.If a slender rod is fixed to the ceiling ta one end and supports a heavy disk at the other end, the disk will oscillate back and forth around the rod axis like a torsion pendulum if given an initial twist and let go. The frequency of the oscillations will depend on the torsional stiffness of the rod and the weight of the disk; the stiffer the rod and the lighter the disk the higher the frequency. Similar torsional oscillations can occur in the crankshafts of reciprocating engines, particularly those with many crank throws and a heavy flywheel. Each crank throw and part of the associated connecting rod acts like a small flywheel, and for the crankshaft as a whole, there are a number of ways or modes in which there small flywheels can oscillate back and forth around the shaft axis in opposition to one another and to the main flywheel. For each of these modes there corresponds a natural frequency of oscillation.When the engine is operating the torques delivered to the crankshaft by the connecting rods fluctuate, and if the crankshaft speed is such that these fluctuating impulses are delivered at a speed corresponding to one of the natural torsional frequencies of the shaft, torsional oscillations will be superimposed on the rotary motion of the shafts. Such speed are known as torsional critical speeds, and they can cause shaft failures. A number of devices to control the oscillations of crankshafts have been invented.Flexible shafts. A flexible shaft consists of a number of superimposed tightly wound right-and left-hand layers of helically wound wires wrapped about a single center wire or mandrel. The shaft is connected to source of power and the driven member by special fittings attached to the end of theshaft. Flexible easings of metallic or nonmetallic materials, which guide and protect the shaft and retain the lubricant, are also available. Compared with solid shafts, flexible shafts can be bent to much smaller radii without being overstressed.For transmitting power around corners and for considerable distances flexible shafts are usually cheaper and more convenient than belts, chains, or gears. Most speedometers on automobiles are driven by flexible shafts running from the transmission to the dashboard. When a valve, a switch, or other control devices is in a hard-to-reach location, it can be operated by a flexible shaft from a more convenient position. For portable tools such as sanders, grinders, and drilling machines, flexible shafts are practically indispensable.KEY, SPLINES AND PINSKeys, splines, and pins. When power is being transmitted from a machine member such as a coupling, a gear, a flywheel, or a pulley to the shaft on which it is mounted, means must be provided for preventing relative motion between the shaft and the member. On helical and bevel gears, relative movement along the shaft caused by the thrust(axial) loads is prevented by a step in the shaft or by having the gear contact the bearing directly or through a tubular spacer. When axial loads are incidental and of small magnitude, the members are kept from sliding along the shaft by means of a set screw. The primary purpose of keys, splines, and pins is to prevent relative rotary movement.A commonly used type of key has a square cross section and is sunk half in the shaft and half in the hub of the other member. If the key is made of steel(which is commonly the case)of the same strength as the shaft and has a width and depth equal to one fourth of the shaft diameter(this proportion is closely approximated in practice) then it will have the same torque capacity as the solid shaft if its length is 1.57 times that of the shaft diameter. Another common type of key has a rectangular cross section with a depth to width ratio of 0.75. Both of these keys may either be straight or tapered in depth. The straight keys fit snugly on the sides of the key ways only, the tapered keys on all sides. Gib-head keys are tapered keys with a projection on one end to facilitate removal.Woodruff keys are widely used on machine tools and motor vehicles. The key is a segment of adisk and fits in a keyway in the shaft that is with a special milling cutter. Though the extra depth of these keys weakens the shaft considerably, it prevents any tendency of the key to rotate or move axially. Woodruff keys are particularly suitable for tapering shaft ends.Because they weaken the shafts less, keys with straight or tapered circular cross sections are sometimes used in place of square and rectangular keys, but the keyways, half in the shaft and half in the shaft and half in the hub, must be cut with a drill after assembly,and interchangeability of parts is practically impossible. When a large gear blank is made by shrinking a high-strength rim on a cheaper cast center, circular keys, snugly fitted, are frequently used to ensure a permanent connection.Splines are permanent keys integral with the shaft, fitting in keyways cut in the hub. The dimensions of splined fittings are standardized for both permanent (press) fits and sliding fits. The teeth have either straight or involute profiles;the latter are stronger, more easily measured, and have a self-centring action when twisted.Tapered circular pins can be used to restrain shaft-mounted members from both axial and rotary movement. The pin fits snugly in a reamed tapered hole that is perpendicular to the shaft surface. A number of straight pins that grip by deforming elastically or plastically when driven into straight holes are commercially available.All the keys and pins that have been described are standard driving devices. In some cases they inadequate, and unorthodox means must be employed. For driving small gear in which there is no room between the bore and the roots of the teeth for a longitudinal keyway, a transverse radial slot on the end of the gear can be made to fit a radial protuberance on the shaft. For transmitting moderate loads, a cheaper and effective connection can be made by forming a series of longitudinal serrations on the shaft with a knurling tool and pressing the shaft into the hole in the driven member, it will cut grooves in the hole and provide, in effect, a press-fitted splined connection. Press and shrink fits are also used, and they can provide surprisingly firm connections, but the dimensions of the connected member must be closely controlled.轴实心轴轴作为机械零件通常是一根圆柱形杆，用来支撑部件并随部件一起转动以接受和传递转动和扭矩。
柴油机外文文献翻译资料
文献出处：Chauhan B S, Kumar N, Cho H M. A study on the performance and emission of a diesel engine fueled with Jatropha biodiesel oil and its blends[J]. Energy, 2012, 37(1): 616-622.A study on the performance and emission of a diesel engine fueled with Jatrophabiodiesel oil and its blendsChauhan B S, Kumar N, Cho H MAbstractBiodiesel either in neat form or as a mixture with diesel fuel is widely investigated to solve the twin problem of depletion of fossil fuels and environmental degradation. The main objective of the present study is to compare performance, emission and combustion characteristics of biodiesel derived from non edible Jatropha oil in a dual fuel diesel engine with base line results of diesel fuel. The performance parameters evaluated were: brake thermal efficiency, brake specific fuel consumption, power output. As a part of combustion study, in-cylinder pressure, rate of pressure rise and heat release rates were evaluated. The emission parameters such as carbon monoxide, carbon dioxide, un-burnt hydrocarbon, oxides of nitrogen and smoke opacity with the different fuels were also measured and compared with base line results. The different properties of Jatropha oil after transestrification were within acceptable limits of standards as set by many countries. The brake thermal efficiency of Jatropha methyl ester and its blends with diesel were lower than diesel and brake specific energy consumption was found to be higher. However, HC, CO and CO2 and smoke were found to be lower with Jatropha biodiesel fuel. NOx emissions on Jatropha biodiesel and its blend were higher than Diesel. The results from the experiments suggest that biodiesel derived from non edible oil like Jatropha could be a good substitute to diesel fuel in diesel engine in the near future as far as decentralized energy production is concerned. In view of comparable engine performance and reduction in most of the engine emissions, it can be concluded and biodiesel derived from Jatropha and its blends could be used in a conventional diesel engine without any modification.Keywords: Biodiesel; Brake thermal efficiency; Exhaust missions; Transesterification 1. IntroductionIn the wake of current energy scenario, major research is focused on sustainable energy solution with major emphasis on energy efficiency and use of renewable energy sources. Diesel engines have proven their utility in the transportation and power sectors due to their higher efficiency and ruggedness. They are also potential sources of decentralized energy generation for small electrification plant. However, concerns about long-term availability of petroleum diesel and the stringent environmental norms have mandated the search for a renewable alternative to diesel fuel to address these problems. Liquid bio-origin fuels are renewable fuels coming from biological sources and have proved to be a good substitute for petroleum derived oil in transportation and small energy needs. These fuels are gaining worldwide acceptance as a solution for problem of environmental degradation, energy security, restricting import, rural employment and agricultural economy. A large variety of alternative fuels are considered potential substitute to petroleum based diesel, however, modification, handling and transportation, ease of production, and investment cost are some of the important parameters that should be considered before using an alternative fuel in an existing diesel engine. The modification required in the engine design need to be made in such a way so as to minimize the investment cost in the engine modification [3].Over the past few years, huge fluctuation in oil prices have been seen, reaching to record $147.27 in 2008 of and then falling back again to $33.87 in December 2008. Even so, over the whole of 2009, the average oil price was still between $60 and $80 per barrel. In 2009, the total level of annual investment in clean energy was $145 billion, only a 6.5% drop from the record previous year, while the global wind power market grew by an annual 41.5%. Oil remains the highest consumed source of energy in the world. Today, renewable energy sources account for 13% of the world’s primary energy demand. Biomass, which is mostly used in the heat sector, is the main source of renewable energy. The share of renewable energies for electricity generation is 18%, while their contribution to heat supply is around 24%. About 80% of the primary energy supply today still comes from fossil fuels . In the light of above, there is an urgent need to reduce dependence on petroleum derived fuels for better economy andenvironment. The most promising liquid biofuels closest to being competitive in current markets without subsidy, are ethanol, methanol, vegetable oils and biodiesel. They have been utilized either in one form or another for more than one hundred years. The search for alternative fuel over conventional petroleum based fuels has been subjected to various studies throughout the world. Thermodynamic tests, based on engine performance evaluation have established the feasibility of using a variety of alternative fuels such as hydrogen, alcohols, biogas, producer gas and host of vegetable oils. Biodiesel is considered a sustainable substitute to diesel fuel due to its renewable nature and positive environmental impact.Depending upon the availability and production capabilities, biodiesel is derived from a large variety of oilseed. Biodiesel derived from soybean oil is of primary interest in the United States while many European countries are concerned with rapeseed oil, and countries with tropical climate prefer to utilize coconut oil or palm oil. In India, around 450 types of oil bearing crops are available for use as energy crops, and the efforts must be put to increase the yield and oil content of these crops. In this context, it is essential to promote the use of non-edible vegetable oil derived fuels either as a substitute or an extender of fossil fuels which would bring energy crops on the forefront in energy scenario. Considering the important parameters such as energy security, green house emission, fast depletion of fossil fuel reserve and potential utilization in existing diesel engine with no or minimum design modification, biodiesel is considered most promising renewable fuel for mankind and environment. In the present study, non edible vegetable oil derived from Jatropha plant was transesterified and major physico-chemical properties were evaluated in accordance with ASTM standards. Further, a compression ignition engine was fuelled with Jatropha methyl ester and its blends with diesel and performance, combustion and emissions characteristics were evaluated to find out their suitability as a diesel engine fuel. The study of combustion characteristics was carried with the help of pressure - crank angle and heat release rate diagrams. The results were compared with those from the diesel fuel.2. Non edible Jatropha biodiesel as a potential substitute for diesel fuelIn recent years, systematic efforts have been made by several researchers to use vegetable oils derived fuels in diesel engines. The oil tested included a number of different raw and processed vegetable oils like rapeseed oil, sunflower oil, palm oil, soybean oil etc. Pascal et al. studied palm oil in CI engines with waste cooking oil, which were converted into esters by a transestrification process. The brake thermal efficiency increases for the PO/Diesel blends. HC emissions for all those fuels except for the PO/Diesel blends are found lower, while CO emissions rise for all types of fuels. NOx emissions were higher at low load, but lower at full load. Gumus et al. in the study transesterified apricot seed kernel oil with methanol using potassium hydroxide as catalyst to obtain apricot seed kernel oil methyl ester. Neat apricot seed kernel oil methyl ester and its blends with diesel fuel were tested in a compression ignition diesel engine to evaluate performance and emissions parameters. Kegl ] discussed the influence of rapeseed biodiesel on the injection, spray and engine characteristics with the aim to reduce harmful emissions. The results indicate that by using biodiesel, harmful emissions can be reduced to some extent by adjusting the injection pump timing properly. Sahoo et al. used non-edible filtered high viscous and high acid value polanga oil based mono esters blended with high speed diesel as a substitute of diesel in a single cylinder diesel engine. Agarwal et al. found that biodiesel-fueled engines produce less carbon monoxide, unburned hydrocarbon, and particulate emissions compared to mineral diesel fuel but higher NOx emissions. Canakci and studied and compared the combustion characteristics and emissions of petroleum diesel and biodiesel from soybean oil. He found significant reductions in PM, CO, and unburned HC, while NOx increased with soybean biodiesel. Fen et al. prepared biodiesel through transestrification from wasted cooking oil and tested it in diesel engine and concluded that B20 and B50 are the optimum fuel blends.Tsolakis et al. studied the effects of rapeseed methyl ester and different diesel/RME blends o n the diesel engine’s NOx emissions, smoke, fuel consumption, engine efficiency, cylinder pressure and net heat release rate and reported increased NOx emissions. When similar percentages (% by volume) of exhaust gas recirculation (EGR) are used in the cases of diesel and RME, NOx emissions are reduced to similarvalues, but the smoke emissions are significantly lower in the case of RME. The retardation of the injection timing in the case of pure RME and 50/50 (by volume) blend with diesel resulted in further reduction of NOx at a cost of small increases of smoke and fuel consumption. Lin et al. studied biodiesel from waste cooking oil as an economical source and thus an effective strategy for reducing the raw material cost. Using waste cooking oil and diesel blends decreases PAHs by 7.53%–37.5%, particulate matter by 5.29%–8.32%, total hydrocarbons by 10.5%–36.0%, and carbon monoxide by 3.33%–13.1% as compared to using ULSD. Bueno et al. studied the engine performance impact of soybean oil ethyl ester blending into diesel fuel and reported an average increase of 4.16% in brake thermal efficiency with B20 blend. Under the same conditions, an average gain of 1.15% in brake power and a reduction of 1.73% in specific fuel consumption with B10 blend were observed. Macor et al. observed a drastic reduction in CO and PM emissions while using biodiesel with respect to home heating oil. The PAHs contained in PM, in case of biodiesel were nearly 13 times less toxic than the oil; formaldehyde on the contrary, was nearly double for biodiesel. The VOCs were very low for both the fuels. The results show that there may be benefits in using biodiesel in home heating or in industrial processes. Taymaz et al. studied the engine performance and exhaust emissions of a diesel direct injection engine using mixed palm olein/Soybean vegetable oil ethyl ester. Torque and brake power output of the engine which uses biodiesel, were slightly lower and specific fuel consumption was higher in comparison to Diesel. Decrease in CO and HC, CO2 emissions, indicates an advantage of exhaust emissions with those of diesel fuel, however, NO and NOx emissions were higher with the biodiesels.The use of edible vegetable oils and animal fats for biodiesel production has recently been of great concern because they compete with human food chain. As the demand for vegetable oils for food has increased tremendously in recent years, it is impossible to justify the use of these oils as fuel use for purpose of biodiesel production. Moreover, these oils would be more expensive to use as fuels. Hence, the contribution(完整文献请到百度文库) of non-edible oils such as Jatropha will be significant for biodiesel production. The adaptation of Jatropha oil to the diesel enginecould be done by using neat Jatropha oil by a dual tank approach, blending the Jatropha oil with diesel and producing methyl or ethyl esters through transestrification process.Petroleum diesel fuel is made up of hundreds of different hydrocarbon chains and contains aromatic hydrocarbons, sulfur and crude oil residue contaminants. However, the chemical composition of biodiesel is different from that of petroleum based diesel fuel. The normal structure of hydrocarbon is preferred for better ignition quality. Biodiesel hydrocarbon chains are generally 16–20 carbons in length and contain oxygen at one end. Biodiesel contains about 10% oxygen by weight, which results in poor oxidation stability . Biodiesel does not contain any sulfur, aromatic hydrocarbons, metals or crude oil residues. Fats and oils are primarily water-insoluble that are made up of 1 mol of glycerol and 3 mol of fatty acids and are commonly referred to as triglycerides. Fatty acids vary in carbon chain length and in the number of unsaturated bonds. The fatty acids found in vegetable oils are summarized in. Some of the properties of vegetable oils are different from animal fats because of their origin. Oil from algae, bacteria and fungi also has also been investigated ]. Vegetable oils consist of 97% triglycerides and 3% as di- and mono glycerides ]. The process of converting vegetable oil into biodiesel fuel is called transestrification. Chemically, transestrification means the reaction of triglyceride molecule with methyl alcohol in presence of catalyst at selected temperature producing glycerin and fatty acid methyl esters. The reaction is shown in . Because the reaction is reversible, excess alcohol is used to shift the equilibrium to the products side. To complete a transestrification stoichiometrically, a 3:1 molar ratio of alcohol to triglycerides is needed. In practice, the ratio needs to be higher to drive the equilibrium to a maximum ester yield. R, R′ and R″ are the alkyl groups of different carbon chain lengths .Table 1.Chemical structure of common fatty acids.Boiling points and melting points of the fatty acids, methyl esters, mono-, di- and triglycerides increases as the number of carbon atoms in the carbon chain increase, but decrease with increase in the number of double bonds . The melting points increase in the order of triglycerides, diglycerides and mono glycerides due to thepolarity of the molecules and hydrogen bonding. The oil samples were subjected to several property tests in accordance with different ASTM standards. The fatty acid composition of Jatropha methyl ester evaluated with the help of gas chromatograph is shown in F i g. 2. The results suggest that unsaturated fatty acid is more than saturated fatty acid in Jatropha biodiesel.The greatest difference in using Jatropha oil as compared to diesel is the higher viscosity which could contribute to higher carbon deposit in the engines and also cause some durability problems. However, the high cetane number and calorific value that is approximately equal to diesel fuel make it possible to use Jatropha oil in diesel engines. Additionally, the high flash point of Jatropha oil makes it safer to store, use and handle than petroleum diesel; 210 °C is the temperature at which it will ignite when exposed to a flame while diesel is only 45–55 °C. Their heating value lies in the range of 39–40 MJ/kg, which is comparatively lower than that of diesel fuels (about 45 MJ/kg). This is because of the presence of chemically bonded oxygen in vegetable oils lowers the heating value by about 10%. The cetane number is in the range of 32–40, while the iodine value ranges from 0 to 200, depending on unsaturation. The cloud and pour point of vegetable oils is higher than that of diesel fuel [21]. The different physico-chemical properties of diesel and Jatropha biodiesel are summarized in Table 2.Table 2.Physico-chemical properties of diesel and Jatropha biodiesel oil.3. Experimental setupA Kirloskar make, single cylinder, air cooled, direct injection, DAF 8 model diesel engine was selected for the present research work, which is primarily used for agricultural activities and household electricity generations. It was a single cylinder, naturally aspirated, vertical, air-cooled engine. The detailed technical specifications of the engine are given in Table 3. The schematic diagram of the experimental setup along with all instrumentation is shown in Fig. 3. The engine trial was conducted asspecified by IS: 10,000. The main parameters desired from the engine were power produced by the engines, engine speed (rpm), fuel consumption, exhaust gas temperature, exhaust gas analysis, crank angle measurement by crankshaft encoder, in-cylinder gas pressure measurement and heat release rate by using pressure transducers. The transducer and thermocouples were fitted at the suitable positions to measure the readings at different engine loadings. The fuel injection system was a traditional system consisting of a single hole pintle nozzle which inject the fuel at 200–205 bar.Table 3.Specification of the diesel engine.After finalizing the procedure for data collection and procurement of the desired instruments, they were put on a panel board. One burette with stop cock and a two way valves was mounted on the front side of the panel for fuel flow measurements and selecting between both diesel fuel and biodiesel. The two fuel tanks of 10 Lcapacity were mounted for storing the fuels on the rear side of the panel at highest position. A VL 437 smoke meter and A VL Di Gas Analyzer were used for the measurements of various exhaust gas parameters. The accuracy and reproducibility of the instrument was ±1% of full scale reading. The detector was a Selenium photocell with diameter 45 mm. Its maximum sensitivity in light was within the frequency range of 550–570 nm. Below 430 nm and above 680 nm, the sensitivity of the instrument was less than 4% related to the maximum sensitivity. The measurement principle for CO, HC, CO2 was infrared measurement and for NO and O2 it was electrochemical measurement. The data acquisition and combustion analysis was done through the software ‘engine-soft’ provided by Apex Technologies a nd this was also used to decompose the extreme data from the readouts of the measuring devices. At the steady state condition, the data collected was repeated to take the average so as to minimize the effect of fluctuations. For switching the engine from diesel to biodiesel, a two way valve was provided on the control panel. Both the fuels from the two tanks could be feed to the engine through this valve separately. The fuel from the valve entered into the engine through the fuel measuring unit. The fuel from fuel measuring unit then entered in to the fuel filter before entering to the engine. The engine was loaded in the range of no load, 20%, 40%, 60%, 80% and 100% load. The performance, combustion and emission characteristics of neat biodiesel and different blends of biodiesel and diesel (5%, 10%, 20%, 30%) were evaluated and compared with diesel fuel.4. Result and discussionsIn this study, analysis of combustion characteristic of Jatropha biodiesel and diesel were carried out. It is clear from Fig. 4 and Fig. 5 that ignition of fuel starts earlier for biodiesel based fuels in comparison to diesel fuel. Maximum cylinder gas pressure was found to be lower for biodiesel based fuels. In diesel engine, cylinder pressure depends on the burnt fuel fraction during the premixed burning phase i.e., initial stage of combustion. Cylinder pressure characterizes the ability of the fuel to mix well with air and burn. High peak pressure and maximum rate of pressure rise correspond to large amount of fuel burnt in premixed combustion stage. It may be dueto higher cetane index of Jatropha biodiesel resulting in shorter ignition delay and more fuel burnt in diffusion stage.The ignition delay in a diesel engine is defined as the time between the start of fuel injection and the onset of combustion. Rapid premixed burning followed by diffusion combustion is typical for naturally aspirated diesel engines. After the ignition delay period, the premixed fuel air mixture burns rapidly releasing heat at a very rapid rate, after which diffusion combustion takes place, where the burning rate is controlled by the availability of combustible fuel-air mixture. The ignition quality of a fuel is usually characterized by its cetane number or cetane index. Higher cetane index/number generally means shorter ignition delay. In the entire set of test, it was found that biodiesel has higher cetane index than conventional diesel fuel. Shorter ignition delay causes lower peak heat release rate to lower accumulation of the fuel. Therefore premixed combustion heat release is higher for diesel, which is responsible for higher peak pressure and higher rate of pressure rise in comparison to biodiesel. The ignition delay depends on fuel viscosity with result in poor atomization, slower mixing, increased mixing and reduced cone angle. Higher engine speed leads to faster mixing between fuel and air and shorter ignition occur.The variation of brake thermal efficiency (BTE) with respect to mean effective pressure is shown in the Fig. 6. From the test results of Jatropha derived biodiesel and their blends in the ratio of 5%, 10%, 20%, 30% and mineral diesel, it was observed that initially with increasing brake power, the brake thermal efficiency of Jatropha biodiesel and its blends also increases together with diesel. The brake thermal efficiencies of the Jatropha biodiesel oil and its blends were found to be lower than diesel fuel throughout the entire range. The possible reasons for this reduction are lower calorific value and increase in fuel consumption of JME and its blends as compared to diesel fuel.The brake specific fuel consumptions (BSFC) in case of Jatropha biodiesel and its blends were also found to be higher than diesel fuel as evident from the Fig. 7. This is mainly due to the combined effects of the relative fuel density, viscosity and heating value of the blends. The higher density of Jatropha biodiesel has led to more dischargeof fuel for the same displacement of the plunger in the fuel injection pump, thereby increasing the specific fuel consumption. The results obtained during the test shows that the brake specific consumption of Jatropha methyl ester and its blends, when used in an unmodified diesel engine was higher than the diesel fuel.The variations of BSEC with respect to change in brake mean effective pressure (BMEP) for Jatropha methyl ester, its blends and diesel fuels is shown in the Fig. 8. It is clear from the figure that the brake specific energy consumption of Jatropha biodiesel and its blends is higher than diesel which is due to high density and low calorific value of the fuel.Fig. 9 shows the variation of exhaust temperature with brake mean effective pressure of diesel fuel and Jatropha biodiesel and its blends. It shows that the exhaust gas temperature increased with increase in brake power in all cases. The highest value of exhaust gas temperature of 505 °C was observed with the Jatropha biodiesel, whereas the corresponding value with diesel was found to be 610 °C. This is due to the poor combustion characteristics of the Jatropha biodiesel and its blends because of its viscosity variation.The variation in CO2 emissions is shown in the Fig. 10. In the range of whole engine load, the CO2 emissions of diesel fuel are lower than that of Jatropha biodiesel and its blended fuels. This is because biodiesel contains oxygen element, the carbon content is relatively lower in the same volume of fuel consumed at the same engine load and consequently the CO2 emissions from the vegetable oil and its blends are lower. The result shows that there was a slight increase in CO2 emissions when using Jatropha biodiesel and its blends.Within the whole experimental range, the CO emission from the Jatropha methyl ester and its blends is lower than neat diesel fuel as shown in the Fig. 11. With increase in biodiesel percentage in biodiesel-diesel blends, CO decreases, as biodiesel is oxygenated fuel and contains oxygen which helps for complete combustion. Hence CO emission decreases with increasing biodiesel percentage in fuel.The values of unburned hydrocarbon emission from the diesel engine in case of Jatropha methyl ester and its blends is less than diesel fuel as evident from the HCemissions are lower at partial load, but tend to increase at higher loads for both the fuels. This is due to lack of oxygen resulting from engine operation at higher equivalence ratio. Thus, high percentage of oxygen leads to low HC.The variation of NOx emissions from Jatropha methyl ester and its blends with respect to diesel fuel are shown in The NOx emissions increased with the increasing engine load, due to a higher combustion temperature. The most important factor for the emissions of NOx is the combustion temperature in the engine cylinder and the local stoichiometric of the mixture. It can be seen that within the entire range of loading, the NOx emissions from the Jatropha biodiesel and its blends are higher than that of diesel fuel. The increase in the NOx emissions is from 2110 ppm to 3129 ppm at full load. The shorter ignition delay and the increased amount of biodiesel undergoing premixed combustion results in higher cylinder pressure and hence temperature. The rate of formation of NOx emissions in diesel engines is primarily a function of flame temperature, which is closely related to the peak cylinder pressure and hence temperature the higher density of biodiesel compared to diesel fuel in conjunction with the increased injection pressure, results in the delivery of a higher amount of fuel at the same injection setting conditions. Combustion, therefore, takes place over a shorter period of time, and this possibly allows less time for cooling by heat transfer and dilution. The above-described trends can explain the higher NOx formation associated with the combustion of biodiesel.Variation of NOX with brake mean effective pressure.Fig. 14 shows the variation of the smoke opacity of Diesel and Jatropha methyl esters and its blends at different brake mean effective pressure (bmep). It can be observed that the smoke density reduced with the use of biodiesel in comparison to the diesel, it can be seen that at low load, the smoke density is somewhat lower for all blends as the load on the engine increases the smoke density increases. Within most of the experimental range, the smoke opacity from the Jatropha methyl ester and its blends is lower than diesel fuel. This is possible because of the higher cetane index and inbuilt oxygen of biodiesel fuel which results in better combustion resulting inreduction in smoke opacity.5. ConclusionThe present study was carried on an unmodified diesel engine which was converted to run on a dual mode operation. The main objective of the present investigation was to evaluate suitability of biodiesel production from Jatropha curcas oil as a fuel for Diesel engine, to evaluate the performance, combustion and emission characteristics of the engine. After transesterification of Jatropha oil, its kinematic viscosity and specific gravity get reduced. Higher flash point of Jatropha methyl ester and its blends than diesel fuel, suggests their safe storage and handling. The biodiesel from Jatropha oil has higher density but lower calorific value than that of diesel, however, the difference is not significantly higher. The kinematic viscosity of biodiesel derived from Jatropha oil is higher than that of diesel. The experimental results show that the engine performance with biodiesel of Jatropha and its blends were comparable to the performance with diesel fuel. The oxides of nitrogen from Jatropha biodiesel during the whole range of experiment were higher than diesel fuel. While running the engine with biodiesel and its blends, emissions such as CO, smoke density and HC were reduced as compared to diesel. These reductions of emissions could be due to complete combustion of fuel. The results from the experiments suggest that biodiesel from non edible oil like Jatropha could be a good substitute fuel for diesel engine in the near future as far as decentralized energy production is concerned.In view of comparable engine performance and reduction in most of the engine emissions, it can be concluded and biodiesel derived from Jatropha and its blends could be used in a conventional diesel engine without any modification. However there are various parameters which can be evaluated in future such as the prediction of best blend with respect to the various engine parameters by varying spray time of fuel using common-rail fuel injection.。
柴油机-外文翻译
diesel engine electronic control technology developmentElectronically controlled diesel engine technology started in the 20th century, 70s, 80s since the 20th century, the United Kingdom Lucas company, Robert Bosch GmbH of Germany, Mercedes-Benz Motor Company, American General Detroit Diesel Corporation, Cummins Inc., Caterpillar Inc., Japan 50 Ling Motor Co. and Komatsu Ltd. are competing to develop new products and market to meet the increasingly stringent emissions regulations.Because diesel engines have high torque, high-life, low fuel consumption and low emissions characteristics of diesel engine vehicles and solving the energy problem of construction machinery the most realistic and most reliable means. Therefore the use of diesel engines has become an increasingly widespread, more and more quantity. At the same time, the power of diesel engine performance, economic performance, emission control and noise pollution are also getting higher and higher. To rely on traditional mechanical control fuel injection system has been unable to meet the above requirements, but also difficult to achieve fuel injection quantity, injection pressure and injection timing fully functioning in accordance with the best working condition requirements. In recent years, with computer technology, sensor technology and information technology is developing rapidly, so that the reliability of electronic products, cost, size, etc. to all diesel engines to meet the requirements for electronic control and electronically controlled fuel injection easy to achieve.In fact, diesel exhaust CO and HC than gasoline engines much less, NOX emissions and gasoline engine similar to, but more exhaust particles, which is related to diesel engine combustion mechanism. Diesel is a non-homogeneous combustion, combustible mixture formed a very short time, and combustible gas mixture formation and combustion process interlaced together. Diesel Fuel Injection through the analysis of the law to be: the atomization of fuel injected into the quality of the gas flow inside the cylinder and combustion chamber shape, etc.directly affect the progress of the combustion process, as well as the generation of harmful emissions. Improve atomization of diesel fuel injection pressure and the effect of the use of pre-injection, such as sub-jet can effectively improve the emissions.After years of research and new technology applications, second generation of the development of the electronic control fuel injection system. In use\"position control\" of the first generation of electronic control fuel injection system, keep the basic composition and structure of traditional fuel injection system, only the original mechanical fuel pump and mechanical control components with electronically controlled fuel injection pump and its control parts replaced, by setting the control system, to improve control accuracy and response speed of diesel engine structure almost do not need to change, the production of good inheritance, easy to upgrade to the existing diesel engine. The disadvantage is that the position control system frequency response is slow, the control frequency is low, control the degree of freedom control precision is not high enough, injection pressure control alone. In the \"time control\" of the first generation of electronic control fuel injection system, basic retain the traditional composition and structure of the fuel injection system, control system, by setting the formation of high frequency control system, digital, determined by the solenoid valve closing time and closed time cycle for oil (spray) quantity and injection timing, the control degree of freedom and control accuracy are incomparable \"position control\", its technical difficulty is how to speed up the need to bulk oil the response speed of high-speed solenoid valve, fuel injection pressure are not independent control at the same time. The first generation of electronic control fuel injection system, including electric inline pump part and electric control system and electric control distribution pump system monomer pump fuel injection system or electric pump nozzle injection system. But whatever electronic control system development, overall, electronic control of diesel engine is the most important thing to the electronic control of fuel injection system, implementation of fuel injection and injection timing with the operating conditions of real time control, controlled fuel injection system is the object. It applies various sensors, real-time detection of diesel engine operating parameters, including speed, temperature, pressure, etc., make them synchronouslyinput computer, and the parameters of the advance has been stored in the computer value or operation of the fuel injection quantity, injection timing pulse spectrum is used in the comparison. After processing and calculation, according to the operation need to be the best to control the output and the executing agency, driving the corresponding part of the diesel engine, diesel engine operating conditions to achieve the best.diesel engine with the past very different from the status quo. Modern diesel engines generally use electric controlled injection, high pressure common rail, turbo-charged in the cold technology, in terms of weight, noise, smoke, etc. has made a major breakthrough, reaching the level of gasoline. With the increasingly stringent international emission control standards (such as Europe, Ⅳ, Ⅴ standard) the promulgation and implementation, whether it is gasoline or diesel engines are faced with severe challenges, the solution is the use of electronically controlled fuel injection technology. Now, the diesel engine electronic control technology developed at the application rate has reached more than 60%.柴油机电子控制技术的发展状况柴油机电子控制技术始于20世纪70年代，20世纪80年代以来，英国卢卡斯公司、德国博世公司、奔驰汽车公司、美国通用的底特律柴油机公司、康明斯公司、卡特彼勒公司、日本五十铃汽车公司及小松制作所等都竞相开发新产品并投放市场，以满足日益严格的排放法规要求。
曲轴加工的技术要求及发展方向——外文翻译、中英文翻译
外文资料The crank processes specification anddevelopment directionThe crank processes specificationThe crank specification is very high, its machine-finishing technological process different and the crank complex degree has the very big difference along with the production guiding principle, but includes following several main stages generally: Localization datum processing; Thick, lathe finishing and rough grinding each host neck and other outer annuluses; Che Lianjing; Drills the oil hole; Correct grinding each host neck and other outer annuluses; Correct grinding Lian Jing; Big, capitellum and key slot processing; Journal surface treatment; Transient equilibrium; Super finishing various journals.May see, the main neck or Lian Jing the turning working procedure all separates with the grinding working procedure, is often middle arrangement some different machined surfaces or the heterogeneity working procedure. After the rough machining can have the distortion, therefore the normal force reduces gradually; Because simultaneously thick, the precision work working procedure carries on separately before, the latter working procedure has the possibility to eliminate the working procedure error, finally obtains the very high precision and the very low roughness. Thick, the precision work separates, and arranges the alignment working procedure behind the cutting force big working procedure, guarantees the processing precision.In order to reduce the distortion which the cutting force causes, guaranteed when precision work precision request, correct grinding various journals, uses the single grinding wheel in turn grinding generally.The journal processing requests high, the main neck and the neck uses continually processes many times.Crank machining development directionAlong with our country numerical control engine bed unceasing increase, the crank rough machining will be widespread uses in the numerical control lathe, the numerical control the milling machine, the numerical control vehicle broaching machine and so on the advanced equipment to the main journal, the connecting rod journal carries on the numerical control turning, in the milling, the vehicle - broaching processing, by will effectively reduce the amount of deformity which the crank willprocess. The crank precision work will be widespread uses the CNC control the crankshaft grinding to carry on the correct grinding processing to its journal, this kind of grinder will provide grinding wheel automatic function requests and so on transient equilibrium installment, center rest automatic tracking unit, automatic survey, self-compensating system, grinding wheel automatic conditioning, permanent link speed, will guarantee the grinding quality the stability.In order to satisfy the processing request which the crank enhances day by day, set the very high request to the crankshaft grinding. The modern crankshaft grinding except must have the very high static state, the dynamic rigidity and outside the very high processing precision, but also requests to have the very high grinding efficiency and more flexibilities. In recent years, requested the crankshaft grinding to have the stable processing precision, for this, had stipulated to the crankshaft grinding process capability coefficient Cp≥1.67, this meant reques ted the crankshaft grinding the actual processing common difference to have the common difference which assigned compared to the crank small one half. Along with the modern actuation and the control technology, the survey control, CBN (cubic boron nitride) the grinding wheel and the advanced engine bed part application, for the crankshaft grinding high accuracy, the highly effective abrasive machining has created the condition. One kind calls it the connecting rod neck follow-up grinding craft. Has manifested these new technical synthesis application concrete achievement. This kind of follow-up grinding craft may obviously enhance the crank connecting rod neck the grinding efficiency, the processing precision and the processing flexibility. When carries on the follow-up grinding to the connecting rod neck, the crank take the main journal as the spool thread carries on revolving, and clamps the grinding all connecting rod neck in an attire. In the grinding process, the wheelhead realization reciprocation swing feed, tracks the biased rotation connecting rod neck to carry on the abrasive machining. Must realize the follow-up grinding, X axis besides must have the high dynamic performance, but also must have the enough tracking accuracy, guarantees the shape common difference which the connecting rod neck requests. The CBN grinding wheel application realizes the connecting rod neck follow-up grinding important condition. Because the CBN grinding wheel resistance to wear is high, in the grinding process medium plain emery wheel diameter is nearly invariable, a conditioning may the grinding 600~800 cranks. The CBN grinding wheel also may use the very high grinding speed, may use generally on the crankshaft grinding reaches as high as the120~140m/s grinding speed, the grinding efficiency is very high.Connecting rod processing and trend of development Connecting rod processing methodThe connecting rod decomposes (also called connecting rod breaks) the technical principle uses the material break theory, first artificial has the whole forging connecting rod semi finished materials big end of hole the fissure, forms the initial break source, then expands with the specific method control fissure, achieved the connecting rod The decomposition processing process enable the decomposition the connecting rod cap, the pole adjoining plane to have the complete meshing jig-saw patterned structure, guaranteed the adjoining plane precise docking, tallies, does not need to carry on the adjoining plane again the processing, simultaneously simplified the connecting rod bolt hole structural design and the whole processing craft, has the processing working procedure few, the economical precision work equipment, the nodal wood energy conservation, the product quality high, the production cost low status merit. Main body and the connecting rod cap separate goal.Trend of developmentAt present, the drop for and the die casting connecting rod host, the important status, are facing the powder to forge the steel connecting rod and a powder agglutination steel connecting rod forming craft challenge. Speaking of the domestic present situation, although the powder metallurgy forging industry had certain development, but must provide the mass and the high grade powder metallurgy forging is not mature. Moreover involves the equipment to renew, aspect expense questions and so on technical change, in next one, in long time, domestically produced connecting rod production also by drop forging craft primarily.The connecting rod is one of internal combustion engine main spare parts, its reducing socket two sizes and the shape position errors have many requests, for example: Diameter, roundness, cylindricity, center distance, parallelism, hole and end surface verticality and so on. How does these erroneous project produce the scene in the workshop to examine, always is in the internal combustion engine profession a quite difficult question.In the connecting rod production, domestic mainly has following several examination method at present: With the spindle survey, namely puts on the spindle in connecting rod two, with the aid of in V shape block, plate, dial guage survey.Because the spindle needs to load and unload, therefore between the hole axis has the gap, the measuring accuracy is very low.中文翻译曲轴加工的技术要求及发展方向曲轴加工的技术要求曲轴的技术要求是很高的，其机械加工工艺过程随生产纲领的不同和曲轴的复杂程度而有很大的区别，但一般均包括以下几个主要阶段：定位基准的加工；粗、精车和粗磨各主颈及其它外圆；车连颈；钻油孔；精磨各主颈及其他外圆；精磨连颈；大、小头及键槽加工；轴颈表面处理；动平衡；超精加工各轴颈。
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中国地质大学长城学院本科毕业设计外文资料翻译系别：工程技术系专业：机械设计制造及其自动化姓名：刘庆鹏学号： 05211602年月日外文资料翻译原文R180柴油机曲轴工艺设计及夹具设计一、研究目的及意义曲轴是柴油机的关键零部件之一，主要用于往复运动的机械中，与连杆配合将作用在活塞上的气体压力变为旋转的动力。
而随着机械化生产逐渐成为当今主流，传统的制造工艺已经不能满足人们的需求。
结合实际进行理论分析，在保证产品质量，提高生产效率，降低生产成本的的前提下，对R180柴油机曲轴工艺进行优化设计。
二、R180曲轴工艺现状从目前的整体水平来看，R180柴油机曲轴基本都是两种材质：一是钢锻曲轴；二是球墨铸铁曲轴。
根据材质选择的不同，其生产方式也不同。
为了保证生产精度，铸造方式生产的曲轴已经广泛运用于R180柴油机的运行。
球墨铸铁具有良好的切削性能，并且可以进行各种热处理以及表面强化处理，故球墨铸铁被广泛运用于曲轴的生产。
但是，曲轴毛坯的铸造工艺生产效率低下，工艺装备参差不齐，性能不够稳定、精度低、报废率高居不下，这一系列的问题都需要优化。
从目前整体水平来看, 毛坯的铸造工艺存在生产效率低，工艺装备落后，毛坯机械性能不稳定、精度低、废品率高等问题。
从以下几个工艺环节采取措施对提高曲轴质量具有普遍意义。
①熔炼国内外一致认为,高温低硫纯净铁水的获得是生产高质量球铁的关键所在。
为获得高温低硫磷的纯净铁水，可用冲天炉熔化铁水，经炉外脱硫，然后在感应电炉中升温并调整成分。
②球化处理③孕育处理冲天炉熔化球铁原铁水,对铜钼合金球铁采用二次孕育。
这对于防止孕育衰退，改善石墨形态，细化石墨及保证高强度球铁机械性能具有重要作用。
④合金化配合好铜和钼的比例对形成珠光体组织十分有利,可提高球铁的强度,而且铜和钼还可大大降低球铁件对壁厚的敏感性。
⑤造型工艺气流冲击造型工艺优于粘土砂造型工艺，可获得高精度的曲轴铸件，该工艺制作的砂型具有无反弹变形量的特点,这对于多拐曲轴尤为重要。
⑥浇注冷却工艺采用立浇—立冷，斜浇—斜冷、斜浇—反斜冷三种浇注方式较为理想,其中后一种最好。
斜浇—反斜冷的优点是：型腔排气充分，铁水充型平稳，浇注系统撇渣效果好，冒口对铸件的补缩效果好，适应大批量流水线生产。
目前，国内大部分专业厂家普遍采用普通机床和专用组合机床组成的流水线生产，生产效率、自动化程度较低。
曲轴的关键技术项目仍与国外相差1～2个数量级。
国外的机加工工艺大致可归纳为如下几个特点。
①广泛采用数控技术和自动线，生产线一般由几段独立的自动化生产单元组成，具有很高的灵活性和适应性。
采用龙门式自动上下料，集放式机动滚道传输，切削液分粗加工与精加工两段集中供应和回收处理。
②曲轴的主要加工工序基准中心孔，一般采用质量定心加工方式，这样在静平衡时，加工量很少。
③轴颈的粗加工一般采用数控铣削或车拉工艺。
工序质量可达到国内粗磨后的水平，且切削变形小、效率高。
铣削和车拉是曲轴粗加工的发展方向。
④国外的曲轴磨床均采用CNC控制技术，具有自动进给、自动修正砂轮、自动补偿和自动分度功能，使曲轴的磨削精度和效率显著提高。
⑤油孔的加工采用鼓轮钻床和自动线，近几年随着枪钻技术的应用，油孔的加工大多已采用枪钻自动线钻孔—修缘—抛光。
⑥曲轴的抛光采用CNC 控制的砂带抛光机，所有轴颈一次抛光只需20多秒，粗糙度可达Ra0.4以下，大大减小了发动机的磨合期。
⑦动平衡一般采用CNC控制的综合平衡机，测量、修正一次完成。
⑧检验一般在生产线上配备MARPOSS或HOMWORK综合检测机，实现在线检测，对曲轴的几乎所有机加工项目均可一次完成检测、显示和打印。
⑨曲轴的清洗采用专用精洗机定点定位清洗，保证了曲轴清洁度要求。
⑩广泛采用了轴颈过渡圆角滚压技术。
专用圆角滚压机自动控制，对所有轴颈圆角进行一次滚压，而且滚压力和滚压角度可自动调节，使圆角处产生最佳的残余压应力，提高了曲轴的疲劳强度。
曲轴热处理的关键技术是表面强化处理。
一般均正火处理，为表面处理作好组织准备。
表面强化处理一般采用感应淬火或氮化工艺，少数厂家还引进了圆角淬火技术和设备。
球铁曲轴具有诸多优点，国内外广泛采用。
但整体水平与国外还有相当差距，除生产规模小、管理落后外，主要差距仍是制造工艺的落后。
借鉴国外的先进技术和工艺方法是提高我国曲轴制造水平的捷径。
外文资料翻译译文1.the purpose and significanceCrankshaft is one of the key components of diesel engines, mainly for reciprocating machinery, and the link will be acting on the piston with the gas pressure into motivation rotation. With mechanized production gradually become mainstream, conventional manufacturing processes can not meet people's needs. Actual theoretical analysis, to ensure product quality, increase productivity, reduce production costs under the premise of R180 diesel engine crankshaft technology to optimize the design.2.R180 Status crankshaft technologyFrom the current point of view the overall level, R180 diesel engine crankshaft are basically two materials: one is forging steel crankshaft; two ductile iron crankshaft. Depending on the choice of materials, their production in different ways. In order to ensure the production of precision casting way to produce the crankshaft has been widely used to run R180 diesel engine. Ductile iron has good cutting, and can be a variety of heat treatment and surface hardening process, it is widely used in nodular cast iron crankshaft production. However, the crankshaft casting production inefficiencies, process equipment varies, an unstable, low accuracy, scrap rate remains high, this series of questions needs to be optimized.From the current overall level, the presence of low productivity, backward technology and equipment, rough mechanical properties of instability, low accuracy, scrap rate and other issues blank casting process. Take measures from the following step of the process to improve the quality of the crankshaft has universal significance.① smelting and abroad agreed that the high temperature molten sulfur to obtain pure is the key to producing high-quality ductile iron. In order to obtain high-temperature low-parathion pure molten iron, can be used to melt iron cupola, the furnace desulfurization, then warmed in an induction furnace and adjust ingredients. ② ball handling ③ inoculation of ductile iron melting cupola base iron, ductile iron alloy of copper and molybdenum using second inoculation. This is to prevent breeding ofrecession, to improve the graphite morphology, refined graphite and ensure the mechanical properties of high strength ductile iron plays an important role. ④ alloyed with a good proportion of copper and molybdenum is very favorable for the formation of pearlite structure can improve the strength of ductile iron, and copper and molybdenum also greatly reduce the sensitivity of ductile iron pieces of wall thickness.⑤molding process air impact molding process is better than clay sand molding process, the obtained precision casting crankshaft, the fabrication of sand with no rebound deformation characteristics, which is particularly important for multi-throw crankshaft. ⑥pouring cooling process using Li pouring - stand the cold, pouring oblique - oblique cold, oblique pouring - pouring in three ways backslash cold ideal, after one of the best of them. Oblique pouring - backslash cold advantages are: exhaust cavity full of molten filling smooth, good gating system skimming effect, casting riser effect of feeding a good, adapt to large-volume production lines.Currently, the most widely used professional factory assembly line production of general machine tools and special combination of machine components, production efficiency, low degree of automation. Key technology projects with foreign crankshaft still a difference of 1 to 2 orders of magnitude. Foreign machining process can be broadly grouped into the following characteristics. ①extensive use of CNC technology and automatic line, production line generally consists of paragraphs independent automated production unit, has a high degree of flexibility and adaptability.Gantry automatic loading and unloading, Drop motorized roller transmission, coolant roughing and finishing two points focus on the supply and recycling. The principal processes reference center hole ② crank, the general quality of the centering processing methods, so that when the static equilibrium, processing small amounts. ③ journal roughing general use of CNC milling or broaching process. Step up to the level of quality kibble after domestic and cutting deformation, high efficiency. Milling and broaching crankshaft rough direction of development.④abroad crankshaft grinding machine adopts CNC control technology, with automatic feed, automatic correction wheel, automatic compensation and automatic indexing features that make the crankshaft grinding accuracy and efficiency improved significantly. ⑤hole machining using drum drilling and automatic line, in recent years, with the application of gun drilling technology has been used mostly processed hole gun drilling automatic line drilling - repair edge - polishing. ⑥crankshaft polishing using CNC-controlled belt polishing machine, a polishing all journal just over 20 seconds, roughness up Ra0.4 less, greatly reducing the run-in period of the engine. ⑦ balancing the general overall balance CNC machine control, measurement, correction once completed. ⑧general inspection on the production line with MARPOSS or HOMWORK comprehensive testing machine, line measurement ofcrankshaft machining almost all projects can be a complete inspection, display and printing.⑨crank cleaning using special fine cleaning machine fixed positioning cleaning to ensure cleanliness requirements crankshaft. ⑩extensive use of journal fillet rolling technology. Special fillet rolling machine automatic control of all journal fillet once rolling, and rolling force and rolling angle can be adjusted automatically, so fillet to produce the best residual compressive stress and improve fatigue strength of the crankshaft.The key technology is the crankshaft surface hardening heat treatment. Generally normalizing, make organizational preparations for the surface treatment. Surface Treatment generally use induction hardening or nitriding process, a few manufacturers have also introduced a rounded quenching technology and equipment.Ductile iron crankshaft has many advantages, widely used at home and abroad. But the overall level and that there is a considerable gap, with the exception of small production scale, poor management, the main gap is still lagging behind the manufacturing process. Learn from foreign advanced technology and technology is to increase the level of the crankshaft manufacturing shortcut.。