基于坐标反推法的偏心轮轴升程测量

采用极坐标测量仪、三坐标测量机等通用型测量仪对偏心轮轴进行坐标测量,其主要配备的都是球形测头,无法直接测得偏心轮轴从动件所对应的升程及升程误差。针对此问题提出了一种基于坐标反推法的偏心轮轴升程测量方法。详细介绍了偏心轮轴的结构、对应不同测头的理论升程计算方法。推导了偏心轮轴表面轮廓点坐标反推平面测头、滚子测头和刀口测头的升程模型公式,利用最小二乘圆圆心和回转中心点确定了偏心圆轮的“桃尖”位置。在一台极坐标测量仪上进行了偏心轮轴测量实验,实验结果表明:基于坐标反推法的升程测量方法是有效的,对应3种测头的坐标反推升程与理论升程的差值分别为0.87, 0.90及0.90μm,基于坐标反推的升程能够更准确反映从动件实际运动规律。

Measurement of Eccentric Wheel Shaft Lift Based on Coordinate Inversion Method

General-purpose measuring instruments such as polar coordinate measuring instrument and coordinate measuring machine can carry out coordinate measurement on the eccentric wheel shaft, they are mainly equipped with spherical probes, which cannot directly measure the lift and lift error corresponding to the eccentric wheel shaft follower.To solve this problem, a measurement method of eccentric wheel shaft based on coordinate inversion method is proposed.The structure of eccentric wheel shaft and the calculation method of theoretical lift for different probes are introduced in detail.The lift model formulas of the plane probe, roller probe and knife-edge probe are deduced by the coordinates of the surface contour point of the eccentric wheel shaft.The center of the circle of least squares and the center of rotation are used to determine the position of the "peach tip" of the eccenter.An eccentric wheel shaft measurement experiment is carried out on a polar coordinate measuring instrument.The experimental results show that the lift measurement method based on the coordinate inversion method is effective, the difference between the coordinate inverse lift and theoretical lift corresponding to the three kinds of probes is 0.87, 0.90 and 0.90μm, the lift based on coordinate inversion can more accurately reflect the actual motion law of the follower.