外文翻译--发动机曲轴复合加工技术成为发展趋势.doc

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1、外文翻译Crank the engine of development of processing technology trendsAfter entering the 21st century, the engine crankshaft manufacture process, tools in all aspects. Leadership for nearly half a century of many knives cutting process and manual process, due to the low and the poor flexible machining

2、precision, is gradually from the stage of history. High-speed, high efficient compound processing technology and equipment quickly into the automobile and automobile parts manufacturing, high efficient compound processing technology in the crankshaft production process in a degree of application, an

3、d will be the inevitable developing trend.The crankshaft processing technology and equipment statusAt present, the domestic older crankshaft production by ordinary machine and the most special machine, production efficiency and automation is relatively low. Balancing device generally adopted the cra

4、nkshaft lathe cutting knife shaft neck and neck connecting shaft, working procedure quality stability, easy to produce large processing stress, difficult to achieve reasonable limits.but. Widely used as ordinary precision MQ8260 crankshaft grinding machine for the coarse grinding and fine grinding,

5、polishing, grinding, usually by artificial operation, the processing quality instability, dimension tolerance.One of the main characteristics of old line is too common, processing equipment, ductile iron crankshaft assembly line has 35 to 40 sets of equipment. The author examines the domestic a cran

6、kshaft forging steel production, the neck and the milling spindles and nc precise neck connecting shaft neck and neck car after a number of processes to finishing processes. Grinding side So this line of more than 60 sets of equipment, product line, site turnaround occupied large area, the productio

7、n efficiency is completely by multiple devices decomposition processes and allowance to improve.But todays car engine crankshaft manufacture is facing the following problemsIt is based on the above situation, since the beginning of the 21st century, high-speed, high precision, high efficient compoun

8、d processing technology and equipment in automobile crankshaft manufacture rapidly, production efficiency improved, so the crankshaft production line production equipment engine number was reduced. The author once in a car engine crankshaft production line equipment, including heat treatment, surfac

9、e strengthening) only 13 equipment, product line, short cycle of high efficiency, easy machining quality control.The crankshaft compound machining technology developmentIn the late 1980s, Germany BOEHRINGER company and HELLER company developed perfect crankshaft car - car pulled machine, this proces

10、s is turning process and crankshaft crankshaft wheeled craft perfect combination, high production efficiency and machining precision, good flexibility, high automation degree, in short time, especially for the sword of the crankshaft is heavy cutting groove, processing can be directly after the cran

11、kshaft jingmo, save the coarse grinding process. Therefore, the crankshaft car - car pull processing technology is an international popular in balancing the crankshaft processing.In the mid 1990s appeared new CNC milling machine makes the crankshaft high-speed balancing process and the crankshaft on

12、 a new step. CNC milling and CNC within the crankshaft speed milling, internal and external crankshaft mill has disadvantages: not easy to knife and cutting speed is low (usually less than 160m/min), the cutting time longer, more investment, circulation machine for a long time. And CNC milling speed

13、, has the following advantages of the crankshaft, high speed cutting ($350m/min), cutting time is shorter, process cycle time is shorter, cutting force is lesser, low temperature workpiece, the tool life, high in fewer knife, machining accuracy is higher, flexible better. Therefore, CNC milling is o

14、utside the crankshaft high-speed balancing the development direction of the crankshaft. According to expert introduction, crankshaft car, car, suitable for shaft neck is heavy cutting groove, the balance blocks side of the crankshaft; without processing But the milling process is not high axial have

15、 heavy cutting slots of the crankshaft. The milling machine for Germany BOEHRINGER company VDF 315 OM - 4 with the high-speed milling machine, it is specially designed for the German BOEHRINGER automobile engine crankshaft design and manufacture of CNC milling machine, the flexible application of wo

16、rkpiece and milling equipment for servo control technology, can a year-end clamping dont change the crankshaft rotary center, and following the crankshaft connecting shaft neck milling. VDF 315 OM - 4 with high-speed milling and integration of the composite structure of bed, workpiece, electronic sy

17、nchronization driver ends with dry cutting machining, high precision, high efficient cutting, This machine use 840D CNC control system, SIEMENS through input parts of basic parameters can be automatically generate processing procedure, can be processed in length and diameter of 4.5-700mm 380mm in al

18、l kinds of crankshaft connecting within its axis, 0.02 mm diameter error for.By comparison, balancing the popular process of crankshaft is: by car and main journal and high-speed milling process, the neck and the high speed milling speed servo tend to outside, adopt dry milling machining. Because th

19、e overseas such equipment, product processing cost price is expensive, some domestic tool manufacturers (e.g., qinghai second machine manufacturing Co., LTD) successively developed nc crankshaft lathe, milling machine, high-speed nc crankshaft lathe, nc crankshaft car special machine.The crankshaft

20、grinding precision CNC cylindrical grinder with domestic situation has quite common, product processing precision has considerable improvement. To meet the increasing demands of the crankshaft, crankshaft grinding machining forward high requirements. In addition to modern crankshaft grinding machine

21、 with high static, dynamic stiffness and high machining accuracy, still require a high grinding efficiency and more flexible. In recent years, the more the requirement of crankshaft grinding machine with stable machining precision of the crankshaft grinding machine, therefore, provided the process c

22、apability coefficient, which means 1.67 experiment.it Cp requirement of crankshaft grinding machine processing tolerance than the crankshaft given half of tolerance. With modern drive and control technology, measurement and control (cubicborazin CBN grinding and advanced machine), the application of

23、 components for crankshaft grinding high-precision grinding efficiency, created conditions. As a kind of connecting with the grinding process neck. It reflects the comprehensive application of these new technologies specific results achieved. With this technology can significantly improve grinding c

24、rankshaft connecting the grinding efficiency, neck and flexible machining precision machining. On the neck for connecting with the crankshaft grinding, with spindle rotation axis, neck for clamping down at once and for all the neck. Connecting grinding In grinding process, grinding head swinging int

25、o to realize reciprocating the eccentric, tracking the connecting rod neck for turning grinding. To realize the X axis with grinding, but must have high dynamic performance, still must have enough, to ensure the tracking accuracy requirements of neck connecting shape tolerance. The application of CB

26、N wheels is connecting with neck important condition of grinding. Due to the high resistance CBN wheels in the grinding process, the diameter of the grinding wheel is almost constant, a dressing grinding 600-800 can crank. CBN wheels can also adopts high grinding speed, in general can adopt the cran

27、kshaft grinding up to 120 140m/s grinding speed, high grinding efficiency. Fixture systemFixture first appeared in the 18th century fixture later. Along with the science and technology unceasing progress, already from a fixture auxiliary tool development becomes a complete range of process equipment

28、. 1 The machine tools fixtureThe international association for the study of the production of statistics shows that in the present, and small batch production of workpiece varieties of workpiece species varieties has total 85%. Modern production requirements of products manufactured by enterprises,

29、in order to adapt to the frequently update market demand and competition. However, general enterprises are still used the traditional special jig, usually in a medium production capacity of the plant, to have about 10,000 sets of even special jig, On the other hand, in many varieties of production e

30、nterprises, every 3 4 years will update 50 80% special jig and fixture actual wear only for 10-20%. Especially in recent years, nc machine tools and machining center, the group technology, flexible manufacturing systems (FMS) new processing technology, the application of the machine tools fixture to

31、 put forward new requirements as follows: 1) can be quickly and easily equipment production of new products, to shorten the production preparation period, lower production cost, 2) can have a group of clamping workpiece similarity characteristics, 3) could be used for precision machining precision m

32、achine tool fixtures, 4) to be applicable to all kinds of modern manufacturing technology of the new type of machine tool fixtures, 5) adopts hydraulic power station with such as high clamping device, to further reduce the labor intensity and improve labor productivity,To improve the standardization

33、 of the machine tools fixture. 2 the development direction of modern the machine tools fixtureThe development direction of modern the machine tools fixture is mainly for standardization, precision and efficiency and flexibility in four aspects.The standardization of the machine tools fixture standar

34、dization and generalization is two aspects. At present already fixture parts and components of the national standard (GB / : T2148 T2259-91 and general-purpose fixture, modular fixture standard etc. The standardization of the machine tools fixture, fixture commercialized, shorten production preparat

35、ion period, lower the total cost of production. (2) precision mechanical products with the increasing accuracy, certainly will raise the accuracy requirement of the fixtures. Precision toolings structure types, such as many more precision indexing gear disk, the degree of accuracy 0.1mm ; the third

36、turning precision for the high precision, o.d.meter for mounting 5 muon m.(3) is mainly used to reduce highlyeffective efficient fixtures processing time and auxiliary time of basic, in order to improve productivity and reduce labor intensity. Common highlyeffective clip clamps, automatic high-speed

37、 fixture and clamping force.on device fixture etc. For example, in the use of electric machine jaw vice clamping work-piece, can improve the efficiency of about five times, In the third claw using high-speed lathe, can assure card from chuck claws in test speed for 9000r/min conditions can still fir

38、mly clamping workpiece, thereby cutting speed increase. Currently, except in the production line, automatic line configure corresponding efficient, automatic fixtures, nc machine tools, especially in machining center appeared on the various automatic clamping work-piece jig automatic replacement and

39、 fixture device, give full play to the efficiency of nc machine tools. (4) flexible，of the machine tools fixture flexible and adaptable machine, it is similar to the flexibility to the machine tools fixture through adjustment, etc, in order to adapt to the combination of process variables. Process v

40、ariable factors include: production batch process characteristic, shape and size of workpiece, etc. Has the characteristics of new jig flexibility are mainly: modular fixture, general adjustable clamp, group clamps, modular fixture, CNC jig, etc. In order to adapt to the modern machinery industry ma

41、ny varieties, and the need for mass production, expand the degree of flexibility, change the fixture structure of special jig for detachable down adjustable structure, development, is the current fixture structure clamp the main development direction 发动机曲轴复合加工技术成为发展趋势进入21世纪以后，发动机曲轴在制造工艺、刀具等方面都发生了巨大的

42、变化。领导了近半个多世纪的多刀车削工艺和手工磨削工艺，由于加工精度低和柔性差等原因，正在逐步退出历史舞台。高速、高效的复合加工技术及装备迅速进入汽车及零部件制造业，高速高效复合加工技术在曲轴加工生产中已有相当程度的应用，并将是其必然发展趋势。 曲轴加工技术设备现状 目前，国内较陈旧的曲轴生产线多数由普通机床和专用机床组成，生产效率和自动化程度相对较低。粗加工设备一般采用多刀车床车削曲轴主轴颈及连杆轴颈，工序质量稳定性差，容易产生较大的加工应力，难以达到合理的加工余量。精加工普遍采用MQ8260等普通曲轴磨床进行粗磨、半精磨、精磨、抛光，通常靠人工操作，加工质量不稳，尺寸一致性差。老式生产线一个

43、主要的特点就是普通设备太多，按加工球墨铸铁曲轴来计算，一条生产线有3540台设备。笔者曾考查过国内某一锻钢曲轴生产线，粗加工采用普通外铣加工主轴颈和连杆颈，然后数控精车主轴颈和连杆颈，再经过多道工序的磨削方转入精加工工序。所以这条生产线设备达60多台，导致产品周转线长、场地占用面积大，其生产效率完全是靠多台设备分解工序和余量来提高的。而当今的汽车发动机曲轴制造业面临的却是以下几个问题 正是基于以上情况，进入21世纪以来，高速、高精、高效的复合加工技术及装备在汽车曲轴制造业中得到了迅速的应用，生产效率得到了很大提高，因此发动机曲轴生产线中生产设备数量得以减少。笔者曾在某一轿车发动机曲轴生产线看到

44、，全线设备（包括热处理、表面强化）只有13台设备左右，产品周转线短、加工效率高、易于质量控制管理。曲轴复合加工技术的发展20世纪80年代后期，德国BOEHRINGER公司和HELLER公司开发出了完善的曲轴车车拉机床，该加工工艺是将曲轴车削工艺与曲轴车拉工艺完美结合，生产效率高、加工精度好、柔性强、自动化程度高、换刀时间短，特别适合有沉割槽曲轴的加工，加工后曲轴可直接进行精磨，省去粗磨工序。因此，曲轴车车拉加工工艺是目前国际上曲轴粗加工中流行的加工工艺之一。20世纪90年代中期出现的新型CNC高速曲轴外铣机床使曲轴粗加工工艺又上了一个新台阶。CNC曲轴内铣与CNC高速曲轴外铣对比，内铣存在以下

45、缺点：不容易对刀、切削速度较低（通常不大于160m/min）、非切削时间较长、机床投资较多、工序循环时间较长。而CNC高速曲轴外铣具有以下优点：切削速度高（可高达350m/min）、切削时间较短、工序循环时间较短、切削力较小、工件温升较低、刀具寿命高、换刀次数少，加工精度更高、柔性更好。因此，CNC高速曲轴外铣将是曲轴粗加工的发展方向。据专家介绍，曲轴车车拉机床特别适合于轴颈有沉割槽、平衡块侧面不用加工的曲轴；而高速外铣则不能加工轴向有沉割槽的曲轴。该铣床为德国BOEHRINGER公司的VDF 315 OM-4高速随动外铣床，它是德国BOEHRINGER公司专为汽车发动机曲轴设计制造的柔性数控

46、铣床，该设备应用工件回转和铣刀进给伺服连动控制技术，可以一次装夹不改变曲轴回转中心，并随动跟踪铣削曲轴的连杆轴颈。VDF 315 OM-4高速随动外铣采用复合材料一体化结构床身，工件两端电子同步旋转驱动，具有干式切削、加工精度高、切削效率高等特点；该铣床使用SIEMENS 840D CNC控制系统，通过输入零件的基本参数即可自动生成加工程序，可以加工长度在450700mm、回转直径在380mm以内的各种曲轴，连杆轴颈直径误差为0.02mm。 由上可以看出，曲轴粗加工比较流行的工艺是：主轴颈采用车拉工艺和高速外铣，连杆颈采用高速外铣，而且倾向于高速随动外铣，全部采用干式切削。由于国外此类设备价格

47、昂贵，产品加工成本很高，国内一些机床生产厂家（如青海第二机床制造有限责任公司）相继开发出了数控曲轴车床、数控高速曲轴铣床，数控曲轴车拉机床等专用机床。 曲轴精加工采用国内数控磨床磨削情况已相当普遍，产品加工精度已有相当程度的提高。为满足曲轴日益提高的加工要求，对曲轴磨床提出了很高的要求。现代曲轴磨床除了要有很高的静态、动态刚度和很高的加工精度外，还要求有很高的磨削效率和更多的柔性。近年来，更要求曲轴磨床具有稳定的加工精度，为此，对曲轴磨床的工序能力系数规定了Cp1.67，这意味着要求曲轴磨床的实际加工公差要比曲轴给定的公差小一半。随着现代驱动和控制技术、测量控制、CBN（立方氮化硼）砂轮和先进

48、的机床部件的应用，为曲轴磨床的高精度、高效磨削加工创造了条件。一种称之为连杆颈随动磨削的工艺。正是体现了这些新技术综合应用的具体成果。这种随动磨削工艺可显著地提高曲轴连杆颈的磨削效率、加工精度和加工柔性。在对连杆颈进行随动磨削时，曲轴以主轴颈为轴线进行旋转，并在一次装夹下磨削所有连杆颈。在磨削过程中，磨头实现往复摆动进给，跟踪着偏心回转的连杆颈进行磨削加工。要实现随动磨削，X轴除了必须具有高的动态性能外，还必须具有足够的跟踪精度，以确保连杆颈所要求的形状公差。CBN砂轮的应用是实现连杆颈随动磨削的重要条件。由于CBN砂轮耐磨性高，在磨削过程中砂轮的直径几乎是不变的，一次修整可磨削600800条

49、曲轴。CBN砂轮还可以采用很高的磨削速度，在曲轴磨床上一般可采用高达120140m/s的磨削速度，磨削效率很高。 机床夹具夹具最早出现在18世纪后期。随着科学技术的不断进步，夹具已从一种辅助工具发展成为门类齐全的工艺装备。1机床夹具的现状国际生产研究协会的统计表明，目前中、小批多品种生产的工件品种已占工件种类总数的85左右。现代生产要求企业所制造的产品品种经常更新换代，以适应市场的需求与竞争。然而，一般企业都仍习惯于大量采用传统的专用夹具，一般在具有中等生产能力的工厂里，约拥有数千甚至近万套专用夹具；另一方面，在多品种生产的企业中，每隔34年就要更新5080左右专用夹具，而夹具的实际磨损量仅为1020左右。特别是近年来，数控机床、加工中心、成组技术、柔性制造系统（FMS）等新加工技术的应用，对机床夹具提出了如下新的要求：