机械加工塑料齿廓偏差影像法测量及抽样特性

Projection measurement of machining plastic gear tooth contour error & sampling inspection characteristics

应用影像法,对机械加工的渐开线塑料齿轮齿廓偏差进行测量。由于塑料齿轮在机械加工中受机械应力和热应力影响较大,而导致齿廓应变较大,为精确反映塑料齿轮的齿廓偏差,并判定塑料齿轮齿廓公差的精度等级,对测量中出现的回转偏心误差、回转分度误差、瞄准示值误差和重复性测量误差进行了不确定度的A类和B类综合评定。并通过统计控制方法中的极差控制图进行分析,得到相同的评定结果。利用对塑料齿轮单齿齿廓偏差的检验,结合随机抽样检验的原理,对塑料齿轮齿廓精度等级进行了判定。最终得出机械加工塑料齿轮,齿形误差较大,超出国标中规定的齿轮精度等级的范围,适合实验室模型展示而不适合用作工业齿轮的结论。

Applying projection method, machining involute plastic gear tooth contour error is measured. As plastic gear tooth contour is much influenced by mechanical stress and thermal stress in machining, thus causing more tooth contour strain, to reflect precisely the measuring resuh of plastic gear tooth contour error, and confirm the precision level of it, the rotation bias er- ror, rotation division error, aiming indication error and repeating measuring error are appraised by A series uncertainty and B se- ries uncertainty. Through analysis by the statistic range controlling chart, a common conclusion is reached. Combining single plastic tooth contour error measurement with random sampling inspection, the precision level of plastic gear contour is confirmed, which is out of the range of GB gear tooth contour precision standards. Thus, plastic gear by machining is more used in display in laboratory than in industry.