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1、本科毕业设计（本科毕业论文）外文文献及译文文献、资料题目：The Processing Of Slender Shaft文献、资料来源：期刊（著作、网络等）文献、资料发表（出版）日期：2010.7院 （部）： 机电工程学院专 业： 机械工程及自动化班 级： 姓 名： 学 号： 指导教师： 翻译日期： 外文文献：The Processing Of Slender Shaft Diameter and length which is more than 1:20 called the slender shaft axiso In cutting force,cutting heat and the
2、 effects of vibration,the slender transverse axis bending easily lose their accuracy,therefore,Turning to reverse progress,when we use the center rest and follower rest reasonably,in addition to the best tool geometric parameters,cutting the amount of a series of effective technological measures,we
3、can achieve the processing requirements.Mechanical analysis is carried out to the deformation of workpiece when turning slender shafts in the normal and reversed direction under two different conditions of clamping.Mathematical models are set up for the calculation of bending deformation resulting f
4、rom cutting force.An example is given to show that bending deformation and the resulting machining error in conditions of reversed turning is much less than that in normal turning.The result has been verified by experiments.Due to the high length-to-diameter ratio of slender shaft,workpiece flexural
5、 deformation and vibration are frequently encountered during cylindrical turning of slender shaft. Thus, turning slender shaft is still a well-known difficult technical problem. Today, this problem is solved basically by empirical workmanship of the operator. This results in the fact that a demandin
6、g technical level of the lathe operator is essential for turning of slender shaft. And the productivity is very low.In order to solve the problem of slender shaft that generate bending deformation and impact seriously on processing quality due to a big slenderness ratio,poor rigidity and turning for
7、ces,the method of slender shaft manufacturing with double-tool turning in lathe is introduced.The model is built based on elementary theory of beam.The lateral displacement of slender shaft is ansysed utilizing finite element(FE) methodThe high precision slender shafts are used very widely in variou
8、s precision machine equipments and apparatus,but its processing is very complicated,and has uncertain precision and low efficiency.Based on the adaptive control system, the system to processing the slender shafts with high precision and efficiency under the NC environment was put forward,which can p
9、rocess diversified slender shafts with various precisions.Turning of slender shaft is difficulty in mechanical processing.The theoretical formula of machining error in turning of slender shaft is derived.The error distributing graph is obtained by computing.The research provides theoretical referenc
10、es for predict machining error in turning of slender shaft.The processing characteristics of the slender shaft: the Hardness of the slender shaft is poor,when Improper turning is Incorrect, It is easy for the role of cutting force and gravity generated bending deformation, vibration, thus affecting
11、the machining accuracy and surface roughness. The thermal diffusion of Slender Shaft is poor ,Under the action of the cutting heat resulting considerable expansion of the line,If a fixed support at both ends of the shaft, the workpiece will stretch and bend. Because the shaft is longer, a tool path
12、use long time, tool wear large, thus affecting the precision of the geometry of parts. Since using the tool holder to turning Slender Shaft if the support block supporting the workpiece on the part of the two pressure Bushi Dang Will affect the machining accuracy. If the parts which are used to supp
13、orting the workpiece have inappropriate pressure on the workpiece,It will affect the machining accuracy .If the pressure is too large or no contact, it does not work and can Not increase the stiffness of parts. If the pressure is too large, the part is pressed to the lathe, the cutting depth increas
14、es, the diameter will be smaller, As with the tool holder to move, the support block supporting the small-diameter cylindrical Department, from the supporting block and the workpiece, cutting out will get out of the workpiece, the cutting depth decreases, turning out the diameter of the larger, late
15、r with the knife and With the large-diameter circle, pressing the workpiece to the lathe again, so that the diameter of a smaller car, so there is continuous change in the law, the thin parts will cars into a bambooshape. Caused by machine tool, workpiece, cutting tool technology system adverse to c
16、utting rigid difficult, not easy to get a good surface roughness and geometrical accuracy.This paper discussed the influencing factors of machining accuracy of slender shaft,and put forward some measures of improving the machining accuracy from the aspects of instal-lation way,cutting tool angle,cut
17、ting parameters and new processing methods.We explore through practice, using a variety of turning devices. such as three-bearing block with the knife, flexible active thimble, pads, bearing bracket,we can use Turning by reverse feeding with the best tool geometry Parameters, cutting and a series of
18、 effective measures. It improves the stiffness of fine long axis and to meet the processing requirements so that the processing of the slender shaft is more be better, the surface roughness will be Ra3.2 above, the taper length of 4m error in the workpiece, only 0.04mm, ovality is 0.01mm , the curva
19、ture is only 0.15mm. nd efficiency greatly increased.The characteristic of slender shaft processing and the cause of its deformation together with the solutions were analyzed and proposed for improving the quality of the slender shaft processing technology.中文译文：细长轴加工工艺直径与长度之比大于1:20的轴称为细长轴。在切削力、切削热和振
20、动的作用下,横置的细长轴很容易弯曲变形而丧失精度,因此,采用反向进给车削,配合中心架和跟刀架的合理使用,加之以最佳的刀具几何参数、切削用量等一系列有效的工艺措施,就可以达到加工要求。针对轴的车削加工,分别对在2种不同装夹条件下进行正向切削和逆向切削时的工件变形进行了力学分析,建立了在切削力作用下产生弯曲变形的解析模型。具体算例表明:逆向切削时工件的弯曲变形以及由此引起的加工误差远小于同等条件下正向切削的变形和误差车削细长轴时,由于长径比大,在切削力作用下会产生弯曲变形与振动,故细长轴的车削加工目前仍是一个工艺难题。当前该问题的解决主要靠操作者的经验,因此对工人的技术水平要求很高,且效率很低.为
21、了解决细长轴零件由于长径比大、刚性差,受切削力作用易产生弯曲变形,严重影响加工质量的问题,提出了双车刀同时切削的方法,运用梁理论建立模型,采用有限元法分析了细长轴的横向位移;经实践得出,双刀车削方法能有效的提高加工精度和车削工作效率,降低单位能耗;并介绍了刀具安装难点与解决方法。高精度细长轴在精密机械设备和仪器仪表中使用很多。针对现有加工手段存在工序复杂、精度不易保证、加工效率低下等缺点,提出了基于自适应控制思想的高精度细长轴高效数控加工系统的解决方案。采用该系统可以很方便高效地加工出各种高精度细长轴。在控制好数控随动支架的位移精度和检测系统的精度的前提下,还可以实现超高精度、超长细长轴的高效
22、自动加工。细长轴的车削加工是机械加工中的难点,在理论上推导出了车削细长轴时产生的加工误差公式,通过计算得到了误差的分布曲线图,为正确地预测加工误差提供了理论上的依据。超细长轴车削的工艺特点：超细长轴刚性很差，车削时装夹不当，很容易因切削力及重力的作用而产生弯曲变形，产生振动，从而影响加工精度和表面粗糙度。超细长轴的热扩散性能差，在切削热作用下，会产生相当的的线膨胀。如果轴的两端为固定支承，则工件会因伸长而顶弯。由于轴较长，一次走刀时间长，刀具磨损大，从而影响零件的几何形状精度.车超细长轴时由于使用跟刀架，若支承工件的两个支承块对零件压力不适当，会影响加工精度。若压力过大或不接触，就不起作用，不
23、能提高零件的刚度，若压力过大，零件被压向车刀，切削深度增加，车出的直径就小，当跟刀架继续移动后，支承块支承在小直径外圆处，支承块与工件脱离，切削李使工件向外让开，切削深度减小，车出的直径变大，以后跟刀架又跟到大直径园上，又把工件压向车刀，使车出的直径变小，这样连续有规律的变化，就会把细长的工件车成“竹节”形。造成机床、工件、刀具工艺系统的刚性不良给切削加工带来困难，不易获得良好的表面粗糙度和几何精度。讨论了影响细长轴加工精度的因素并从装夹方式、刀具角度、切削用量,以及新加工方法等方面阐述了提高细长轴加工精度的措施。我们在实践中，经过不断摸索，采用各种车削装置：如三支承块跟刀架、弹性活络顶针、垫块、托架支承，车削中采用反向进给车削，配合以最佳的刀具几何参数、切削用量。等一系列有效措施。提高了超细长轴的刚性，满足了加工要求，使的加工的超细长轴效果良好，表面粗糙度达到Ra3.2以上，锥度误差在工件全长4m中仅0.04mm，椭圆度0.01mm，弯曲度仅为0.15mm。且工效大大提高。分析了细长轴加工的特点及引起变形的主要原因,并从工艺方面入手提出具体解决办法,以提高细长轴的加工质量。
