圆柱面凸轮螺旋槽加工精度的影响因素与解决方案

在机械加工中,工件的加工精度是其加工质量的核心,影响数控机床工件轮廓加工精度的因素很多,文中以圆柱面凸轮螺旋槽零件的铣削加工为例,介绍了影响其加工精度的几个主要因素,通过对其影响因素及误差来源进行分析,有针对性地提出了凸轮螺旋槽加工的解决措施,从而提高了工件的加工精度.     

车削加工中影响工件加工因素分析

在车削加工中有很多因素影响着零件的加工质量,根据实际工作中积累的经验,试通过影响工件加工因素的分析,从而提高车削加工质量及工件精度。     

基于S型检验试件的数控机床动态性能辨识新方法

五轴数控机床动态性能是影响工件加工质量的重要因素,S型试件作为校验机床动态性能的检验试件,在实际应用中取得了一定成果.为进一步确定机床的加工状态,提高工件加工质量,提出了一种基于S型试件切削的五轴数控机床动态因素辨识方法.综合采用了多体运动学、模糊理论、BP神经网络理论对机床动态因素进行辨识.该方法可以用于评估数控机床的动态性能,通过误差溯源给出的机床动态因素,可用于指导机床的维修和调整,保障关键工件的数控加工质量.     

浅析影响数控年床加工精度的因素

在机械加工过程中,经常有很多因素影响工件的加工质量,为使工件达到所要求的质量要求,在加工前就必须将各种影响加工精度的因素考虑进去,也就是要对影响机械加工精度的因素进行分析,并提出相应的解决方案。本文结合自己的实践经验,就影响数控车床的机械加工精度因素做一下分析。     

浅析机械加工精度的影响因素及提高措施

在机械加工过程中,有很多因素影响工件的最终加工质量,工件的加工质量要求及减少各种因素对加工精度的影响是机械加工前必须考虑的事情。通过分析影响机械加工精度的主要因素,结合多年的工作实践,有针对性地提出提高机械加工精度的对策措施。     

论机械加工误差及提升精度的措施

在进行机械加工之时，工件的最终加工质量会受到诸多因素的影响，因此，在加工之前，就需要考虑到如何去提升加工精度，确保工件能够达到加工的质量要求。本文首先分析了机械加工误差出现的原因，然后提出具体的加工精度提升方式，希望能够提升所有工件加工的质量。     

数控电火花线切割走丝路线的选择及优化

数控电火花线切割加工是实现工件尺寸加工的一种电加工技术,是模具加工的常用加工方法之一,对电火花线切割各项工艺指标中,影响加工质量因素很多,而加工路线的选择将直接影响零件变形的大小并影响加工精度.     

某航天型号轴类工件的ELID精密磨削加工工艺技术研究

为了探究SiCp/Al复合材料轴类工件精密加工的新途径,采用ELID精密超精密磨削加工技术,对其进行精密加工试验,并分析加工机理及试验影响因素。试验结果表明:砂轮转速、进给量、磨削深度和进给速度是影响表面加工质量的主要因素。当砂轮转速在1 500 r/min、磨削深度是3μm和进给量为0. 25μm时,磨削效果最佳,可以有效地提高加工效率,改善工件表面加工质量,得表面粗糙度R_a为0. 163μm、圆柱度为0. 85μm的已加工表面。     

数控加工振动波纹的消除技术研究

切削加工的振动(颤振)问题仍是机加工生产中提高生产效率及产品质量的主要限制因素,它不仅会使生产率和工件加工精度下降,还会使刀具与机床设备损坏.数控加工中,产生加工波纹的主要因素是机床工件系统的振动为提高零件的表面加工质量,提高产品的质量,必须解决加工中的振动.为此,本文建立了一种包括机床的机座、机身、刀具、工件、夹具的振动模型,利用有限元技术解决由于机床振动产生的加工质量问题.     

汽车轮毂柔性加工夹具的定位误差分析

定位误差分析是夹具设计过程中的重要环节,直接影响到被加工工件的加工质量和生产成本.针对所设计的汽车轮毂柔性加工夹具,提出一种夹具误差映射模型;建立了机床坐标系、轮毂加工夹具坐标系和工件坐标系,得出了夹具定位元件尺寸公差和工件位置与姿态误差之间的函数关系.在忽略其他影响因素(如切削温度、变形、刀具和机床加工精度等)对轮毂...     

磨削温度场的有限元模拟及仿真

金刚石砂轮磨削结构陶瓷过程中,所产生的磨削热是影响工件表面质量的关键因素之一,而磨削参数对工件表层温度分布有重要影响。本文采用有限元法,通过两种陶瓷材料对比分析,运用ANSYS软件对磨削温度场进行了仿真研究,利用仿真模型对影响因素作了分析。     

多线切割机过程张紧力控制的研究

多线切割机过程张紧力是影响切割线运动状态的重要因素之一,对加工件表面质量和加工精度及切割线寿命都有着重要影响。对过程张紧力的特点及其影响因素进行了分析,通过采用磁场力来合理的控制过程张紧力,是改善加工件加工质量及提高钢线寿命的有效途径。     

影响弹性膜片对工件定心精度因素分析

在机床夹具设计时,弹性膜片的设计对工件的定心精度有着重要的影响。从弹性膜片的设计方面考虑,提出了弹性膜片设计时影响定位传动精度的因素,为弹性膜片设计时提高定位精度提供参考。     

An Integrated Model of a Fixture-Workpiece System for Surface Quality Prediction

Surface quality is a major factor affecting the performance of a component. The machined surface quality is strongly influenced by the external loads during the fixturing and machining processes. In machining process development, it is highly desirable to predict the quality of a machined surface. For this purpose, an integrated finite element analysis (FEA) model of the entire fixture–workpiece system is developed to investigate the influence of clamping preload and machining force on the surface quality of the machined workpiece. The effects of fixture and machine table compliance (from experimental data), and the workpiece and its locators/clamps contact interaction, and forced vibration, on the machined surface quality are taken into account. This simulation model provides a better understanding of the causes of surface error and a more realistic prediction of the machined surface quality. The deck face of a V-type engine block subjected to fixture clamping and a face milling operation is given as an example. A comparison between the simulation result and experimental data shows a reasonable agreement.     

A study on the magneto-assisted spiral polishing on the inner wall of the bore with magnetic hot melt adhesive particles (MHMA particles)

The spiral polishing mechanism employed a fast turning screw rod to drive the abrasive for workpiece surface polishing. In this study, the powerful ring magnet installed around the workpiece would attract the self-developed magnetic hot melt adhesive particles (MHMA particles) during the process of polishing, driving the SiC particles against the workpiece, the inner wall of the bore. At the same time, the flexibility of MHMA particles helped improve the surface quality of the bore by preventing the SiC particles from heavily scratching it. The effects of magnetic flux density, size and concentration of SiC particles, concentration of MHMA particles, viscosity of silicone oil, revolution speed of the spindle as well as machining time and machining gap on operation temperature, slurry viscosity, surface roughness, and material removal were discussed and the best parameter combination was identified based on the results of the experiment. The effects of each machining parameter on the finished surface topography of the workpiece were also examined. Both analysis of variance and F-test indicated that magnetic flux density and the concentration of MHMA particles were the two most important variables affecting the surface roughness. In other words, magnetic force helped improve spiral polishing. Furthermore, the results showed that adding new MHMA particles to the slurry greatly improved the surface quality, at a rate of 90 %, and reduced the workpiece surface roughness from 0.9 μm down to 0.094 μm.     

超声振动磨削陶瓷的温度场特性研究

采用人工热电偶法,通过普通磨削和超声振动磨削对比实验,对陶瓷材料ZrO2平面磨削的温度场进行了实验研究。并对磨削参数与磨削温度的关系,进行了理论分析及实验验证。结论表明:距磨削表面越远,其磨削温度的峰值越远离热源;增大磨削深度、提高磨削速度和工作台进给速度都会使工件表面温度升高。正交试验表明,磨削深度对温度场的影响较大。普通磨削时工件表层的温度较高,易发生磨削烧伤,采用超声复合磨削能有效降低工件表层温度。     

基于ANSYS的单磨粒与工件接触摩擦的研究

磨粒与工件的摩擦状况是直接影响抛光过程及抛光质量的重要因素。根据单磨粒对工件表面接触压力的实验数据,利用ANSYS有限元分析软件,研究了单磨粒对工件表面的接触压力和摩擦力,结果表明,磨粒与工件间的摩擦边界条件更接近粘着摩擦。     

Modeling of positional variability of a fixtured workpiece due to locating errors

In manufacturing practice, fixtures play an important role in locating and restraining a workpiece. It is clear that locating error is one of the factors that significantly contribute to workpiece quality in the early stage of machining. In this study, we develop a mathematical model that is able to predict geometric variation of a resultant-machined surface when the tolerance of a datum feature is given. A model for a 2-D scheme was initially established that subsequently expanded to a more realistic case in a 3-D scenario. Results from the model show that when variability of a datum feature is allowed, a paraboloid-shaped variational function of a machined surface is detected.     

Some investigations into development of nozzle and suction system for air blast shot peening machine

Shot peening is an important surface enhancement process, which helps in assuring satisfactory fatigue life and reliability of the automotive, aerospace and marine components. One of the most important factors affecting shot peening performance is the type of shot peening machine. This paper presents an innovative design of a laboratory-based air blast shot peening machine. This machine has a vertical nozzle suction system to take the advantage of gravity feed as well as the feed created by suction of the pressurized air. Special attention was paid to the design of the nozzle and the mixing chamber so as to obtain adequate suction of shots. The performance of the machine was evaluated by carrying out various shot peening tests on AISI 1045 steel specimens. The tests included microscopic examination of coverage with ×10 magnification lens, fatigue and wear resistance. The wear resistance of the peened AISI 1045 material increased by 3.5 times the unpeened one. The fatigue tests showed improvement in fatigue life of the workpiece up to about four times. Besides, there was an increase in yield and torsional strength of the workpiece by about 1.5 times.