微型电机轴搓碾校直机的设计

介绍了一种平板搓碾校直机的设计与计算。这种校直机不同于常见的多辊双曲线辊子校直机和辊轮精密校直机，它变传统的通过连续不断的快速局部挤压、变形来校直轴类工件为对轴类工件整体搓碾挤压进行校直。这种搓碾挤压校直方式特别适用于微型电机轴这样的直径微小的短轴。     

PCI-1716数据采集卡在校直测控系统中的应用

应用研华PCI-1716多功能数据采集卡和32位动态链接(DLL)驱动程序接口,在VB平台上实现对PCI-1716数据采集卡的驱动和控制;根据汽车转向器扭力杆校直系统的要求,采集轴旋转过程中位移传感器检测的轴截面外圆周最大径向跳动量对应的电信号,实现实时数据采集、分析和处理,并完成校直系统的各项测量和控制任务。实验表明,该系统能快速高效地进行数据采集,计算矫正量、实施校直,并直观输出校直结果。系统界面友好,操作方便,结果可靠。     

自重引起的挠度对曲轴跳动量测量的影响

在发动机传动装置中,曲轴是极为重要的零件之一,由于其形状和结构的复杂,加工后的成品通常存在较大的径向跳动,而导致挠曲变形,为保证曲轴的性能,需要对其进行校直。跳动量的测量是校直工艺中相当重要的一个环节,但跳动量的测量往往会受到曲轴自重引起的挠度的影响,为此,文中提出了一种综合利用有限元分析和插值计算的方法,来去除自重影响,从而实现曲轴跳动量的精确测量,为校直工艺参数的准确确定进而开发出精密曲轴校直机奠定了坚实的基础。     

自动校直机的自主开发及其在现代汽车制造业中的应用

以BUM系列校直机为例,阐述了轴类零件自动校直机的工作原理和技术特点,重点介绍了该系列校直机对于由工件缺陷引起的假性弯曲的处理方法和防止校直过程中工件断裂的声发射检测功能.展现了轴类自动校直机在现代汽车制造业的应用前景.     

全自动卧式校直机误差分析及补偿

利用金属塑性变形后产生残余变形的原理对发生弯曲变形的工件主动加载可实现轴类零件的精确校直.在借鉴现有的门式结构和C型结构校直机基础上提出一种全新的四导柱卧式原理样机,样机机构运动由4个步进电机驱动,兼具工件尺寸检测和校直加工功能,便于实现自动化控制.本文重点分析了原理样机的加工安装误差对工件测量精度的影响和结构刚度对校直行程的影响,给出了校直行程误差补偿模型.原理样机实验表明,校直控制精度可达0.05mm.     

轴类零件校直的预留量计算

由于在实际生产中压下某一弯曲位置会对其他弯曲位置有很大的影响,造成反复多次下压,影响工作效率,从而不能适应大批量生产的要求,也不能满足对校直精度越来越高的要求.本文针对这一问题,运用空间几何和轴变形理论作为基础来研究对弯曲轴类零件校直时确定校直预留量的计算方法,来达到一次或者仅用几次校直使零件满足精度要求.实验证明这种算法加快了生产节拍,从而提高效率.     

轴类零件校直的预留量计算

由于在实际生产中压下某一弯曲位置会对其他弯曲位置有很大的影响，造成反复多次下压，影响工作效率，从而不能适应大批量生产的要求，也不能满足对校直精度越来越高的要求。本文针对这一问题，运用空间几何和轴变形理论作为基础来研究对弯曲轴类零件校直时确定校直预留量的计算方法，来达到一次或者仅用几次校直使零件满足精度要求。实验证明这种算法加快了生产节拍，从而提高效率。     

轴类工件中心孔的加工

轴类工件中心孔的加工济南汽车制造总厂陆靖一、问题的提出由于轴类工件的中心孔精度问题，造成轴类工件径向跳动超差，在轴类工件径向跳动不允许大于３丝处，一般跳动８丝之多，有的甚至跳动达１０余丝。这一问题在较长的时期内未能解决，为此曾提出以磨床精加工中心孔．...     

轴类工件的校直参数在线检测方法的研究

研究大批量生产轴类工件进行自动校直工艺的校直参数的在线检测方法,给出检测原理模型和检测装置结构,提出两种基准轴线的确定方法及其修正参数的数学模型,并成功地运用在我们研制的YH40-25型250kN精密校直液压机上。     

升降支座

这种升降支座如同千斤顶一样,它主要用于支承轴类零件的,如图1。在检测轴类工件的跳动量时,将工件的基准部位放在两个升降支座的滚子上,用千分表测量欲检部位,旋转着工件就可测出工件的跳动量值。这样比使用V形铁检测稳定,工件转动轻快,因为工件     

中小型轴类零件旋转弯曲矫直工艺数值模拟研究

直线度是轴类零件重要的质量参数之一,矫直是轴生产过程中的一道必要工序。针对现有矫直工艺的局限性,提出中小型轴类零件旋转弯曲矫直工艺。基于通用有限元软件LS-DYNA,使用Y-U强化模型对工艺过程进行了数值模拟研究,揭示其矫直机理,探究各因素对矫直效果的影响。研究结果表明,矫直过程中材料任意质点应力均经历多次的正负交替变化,在逐渐卸载过程中使轴向任意微段的曲率逐渐趋近于零,实现其矫直。残余挠度随着弯曲量的增加而降低,当弹区比达到0.2时,残余挠度达到了最小。随着旋转速度的增加,残余挠度先减小再增大,当旋转速度与弯曲量的比值为125r/rad时,矫直效果较好。长径比、初始挠度(大小及挠曲形式)以及初始残余应力对矫直效果影响较小,采用相同的工艺参数均取得了良好的矫直效果。数值模拟结果验证了工艺的可行性,无需经过复杂的初始挠度测量,光轴和阶梯轴矫直后残余挠度均在0.1mm以内。     

六方水泵传动轴的直线度测量与校直方法研究

采用激光位移传感器对六方水泵轴的直线度进行直接检测,引入效率极高的矢量校直方法,开拓出对具有直线度要求的工件进行检测与校直的新途径,并采用反向法进行机床自身导轨误差分离,极大地提高了相同硬件条件下的检测精度。     

外圆切入磨削加工精度的研究

在考虑砂轮磨损和磨削能力变化的情况下,建立了磨削过程中工艺系统弹性变形微分方程式。分析了磨削过程中基本尺寸参数及工件原始形状误差的变化规律。并对磨削过程基本尺寸参数的变化及工件原始形状误差的纠正进行了试验研究。同时,带考察了切入进给速度对工件残余形状误差的影响。     

轴交角误差对内齿轮刮齿加工精度的影响分析

针对内齿轮刮齿加工过程中,由于轴交角误差的存在而影响齿轮加工精度的问题,为了提高刮齿机的加工精度,首先建立了无进给、刀具进给和工件进给三种运动方式下刀具与工件之间的运动学模型;其次,通过分析不同轴交角误差方向下刀具和工件之间的相对运动关系,研究了内齿轮齿廓加工误差的产生机理;然后,通过建立多因素耦合关系模型,分析了不同轴交角误差方向对刮齿加工误差的影响程度,获得了最佳的轴向进给方式和轴交角误差方向;最后,通过样机试切实验验证了理论分析的有效性,样机满足6级加工精度要求。     

A numerical study of the effects of cutter runout on milling process geometry based on true tooth trajectory

Cutter runout is a common phenomenon affecting the cutting performances in milling operations. To date, most of the milling process models considering cutter runout were established based on the circular tooth path approximation, which brought errors into the runout estimation. In this paper, a new approach is presented for modelling the milling process geometry with cutter runout based on the true tooth trajectory of cutter in milling. The mathematical relationship between the trajectories generated by successive cutter teeth with runout is analysed. The milling process geometrical parameters, including the instantaneous undeformed chip thickness, the entry and exit angles of a cutting tooth, and the ideal peripheral machined workpiece surface roughness, are modelled according to the true tooth trajectories. Numerical method is used to solve the derived transcendental equations. A simulation study of the effects of cutter runout on milling process geometry is conducted using the models. It was found that the change of cutter radius for a tooth relative to its preceding one is the most important factor in evaluating the effects of cutter runout.     

大型整体结构件数控加工变形的安全校形理论研究

研究了整体结构件校正需要满足的基本曲率关系，进而分析了曲率与弯矩的关系。建立了校正整体结构件弯曲变形的弯矩方程和校正曲率方程。为了便于生产操作，给出了校正工件的加工变形所需压下位移量的计算公式。研究了安全校形参数阀值。     

Cutter workpiece engagement region and surface topography prediction in five-axis ball-end milling

Based on the machining tool path and the true trajectory equation of the cutting edge relative to the workpiece, the engagement region between the cutter and workpiece is analyzed and a new model is developed for the numerical simulation of the machined surface topography in a multiaxis ball-end milling process. The influence of machining parameters such as the feed per tooth, the radial depth of cut, the angle orientation tool, the cutter runout, and the tool deflection upon the topography are taken into account in the model. Based on the cutter workpiece engagement, the cutting force model is established. The tool deflections are extracted and used in the surface topography model for simulation. The predicted force profiles were compared to the measured ones. A reasonable agreement between the experimental and the predicted results was found.     

An improved methodology for the experimental evaluation of tool runout in peripheral milling

The modeling of cutting forces plays an important role in the progress of research and technology in most machining processes. In particular, peripheral milling is a cutting process difficult to model due to the large number of variables involved. Among these variables, tool runout affects process performance by modifying milling force patterns, shortening the tool life and machine components, and by degrading workpiece quality. In this paper, a methodology to evaluate tool runout in peripheral milling is presented. The use of a boring toolholder is proposed to make controllable changes in the tool offset that modifies tool runout. In addition, the proposed methodology has been validated by means of a piezoactuator-based system that allows tool runout compensation through controlling workpiece displacement. Experimental and simulated results presented in this paper reveal the practical applications of this methodology for researchers and engineers involved in the practice of milling and its modeling.     

新型点磨削砂轮磨削参数对磨削温度影响研究

提出了一种带有粗磨区倾角θ的陶瓷结合剂CBN点磨削砂轮,这种新型砂轮具有磨除率高、加工精度好等优点。研究了磨削热产生与分配理论和红外测温原理。分别用不同θ角的砂轮在一系列磨削参数条件下磨削QT700材料的阶梯轴,用Thermovision A40M热像仪测量砂轮磨削工件时接触区的平均温度,得出了偏转角α、磨削深度ap、工件轴向进给速度vf和砂轮速度vs在磨削过程中对磨削温度的影响规律,并且比较了在同一组磨削参数下,三种不同θ角砂轮对磨削温度的影响情况。     

Theoretical modelling of cutting forces in helical end milling with cutter runout

A theoretical cutting force model for helical end milling with cutter runout is developed using a predictive machining theory, which predicts cutting forces from the input data of workpiece material properties, tool geometry and cutting conditions. In the model, a helical end milling cutter is discretized into a number of slices along the cutter axis to account for the helix angle effect. The cutting action for a tooth segment in the first slice is modelled as oblique cutting with end cutting edge effect and tool nose radius effect, whereas the cutting actions of other slices are modelled as oblique cutting without end cutting edge effect and tool nose radius effect. The influence of cutter runout on chip load is considered based on the true tooth trajectories. The total cutting force is the sum of the forces at all the cutting slices of the cutter. The model is verified with experimental milling tests.