In-process roundness measurement system for cylindrical machine parts of small diameter w|th run-out error compensation

本课题的研究目标是开发一种既能评价车削圆柱件圆度又能评价车床主轴转动误差的过程测量系统，该系统的目标测量精度为亚微米级，被测圆柱件直径小于2mm。所开发的系统由测量仪器、信号处理设备和数据分析系统组成。该系统的测量仪器由三个光学传感单元组成。每个单元都有一个平行的光束和双光电二极管来检测光束的不对称功率分布，在三束光束的交叉处设置一个圆柱旋转的工作，其中两束是正交的。从相关双光电二极管的差分信号可以检测到垂直于各光束轴的工作位移。然后利用这两个正交的传感单元将工件的跳动轨迹绘制为Lisajous图形。对于工件本身的圆度测量，采用了所谓的v块法。两个传感单元可视为光学虚拟v块，其余传感单元可视为切向式位移传感器。测量实验采用直径为1mm的圆柱零件，转速为300 rpm。结果表明，该系统得到的圆度曲线与商用仪器测得的圆度曲线在每转波动数（UPR）上基本一致。对包含在跳动轨迹中的形状误差进行了有效补偿。当采用主要包含3阶UPR振幅的小圆柱部分时，补偿前的跳动轨迹为与仿真结果相似的方形轨迹。径向圆跳动值为1.24μn。利用实测圆度轮廓进行补偿后，圆角变为圆角，圆度跳动减小到0.71μm。因此，可以确定所开发的系统是跳动轨迹中圆柱零件圆度轮廓不受影响的跳动误差测量系统。少

An objective of our study is to develop an in-process measurement system which can evaluate both the roundness of turned cylindrical part and the rotational error of lathe spindle, Cylindrical parts to be measured are smaller than 2 mm in diameter and the target measurement accuracy of the system is the range of sub-micrometer. The Developed system is composed of measurement instrument, signal processing equipment and data analysis system. The measuring instrument of the developed system consists of three optical sensing units. Each unit has a parallel light beam and twin photo diodes to detect the asymmetrical beam power distribution, A cylindrically turned work is set within the crossing of the three light beams, where two of them are orthogonal. The work displacement perpendicular to each beam axis can be detected from the difference signal of the related twin photo diodes. Then the run-out locus of the work can be drawn as a Lisajous figure using the two orthogonal sensing units.As … More to the roundness measurement of the work itself, so-called V-block method was adopted. The two sensing units may be regarded as an optical virtual V-block and the remaining sensing unit as a tangential type displacement sensor.The measurement experiment was carried out with turned cylindrical part of 1mm in diameter at 300 rpm. As a result, the roundness profile by developed system is in rough agreement with the roundness profile by commercial instrument in undulation per revolution (UPR). The form error which was included in the run-out locus was effectively compensated. The run-out locus before the compensation was the square locus which was similar to simulation result, when small cylindrical part which mainly contains amplitude of 3rd UPR were used. Then, the value of radial circular run-out was 1.24μn. As a result of compensation using the measured roundness profile, the square corner became round, and the value of circular run-out decreased to 0.71μm. Consequently, it was able to be confirmed that the developed system was the run-out error measuring system in which the roundness profile of the cylindrical part did not influence in the run-out locus. Less