Development of Rapid In-process Measurement of Surface Roughness for In-line Total Check of Surface Quality

表面光洁度一般由表面粗糙度测试仪测量，其示踪笔速度较低，为零点几毫米每秒。因此，该批生产的所有零件的表面光洁度都是根据验收抽样中少数零件的测量结果来判断的。提出了利用旋转磨削工件热电效应进行表面光洁度的新型机器测量技术，并开发了表面光洁度的快速机器测量系统。在磨削过程中，工件表面的温升影响传感器的输出，该传感器具有一对平行的独立的热电偶线，并具有一定的张力。为了利用工件表面温升抵消信号分量，提取估计表面粗糙度的分量，我们开发了两种抵消方法，并对其有效性进行了实验研究。结果，我们成功地测量了外圆插拔磨削过程中表面粗糙度的变化。其他结论如下。1. 所开发的带有热电偶导线的接触式传感器的输出与表面光洁度近似呈线性关系。灵敏度随测量速度和工件外围速度的增加而提高，系统在测量速度下获得的表面光洁度约为表面粗糙度测试仪的两千倍。3. 采用较粗的热电偶导线提高了传感器的灵敏度。4. 该测量系统需要施加很大的测量负荷，使热电偶导线与工件表面保持稳定的接触。此外，测量负载0.98 N时的灵敏度高于0.29N时的灵敏度。

The surface finish is generally measured by the surface roughness tester with lower tracing stylus speed of zero point several millimeters per second. Therefore, the surface finish of all parts manufactured in the lot is judged based on the measured results of only few parts by the acceptance sampling. We propose the novel on machine measurement technique of surface finish with the thermoelectric effect for rotating ground workpiece and the rapid on machine measurement system of surface finish is developed. In a grinding process, the temperature-rise of workpiece surface affects the output of developed sensor, which has a pair of parallel separate thermocouple wires with a certain tension. In order to cancel the signal component by a temperature-rise of workpiece surface for an extraction of component estimating surface roughness, we developed two kinds of cancellation methods and experimentally investigated their availability As a result, we have successfully measured a variation of surface roughness in a cylindrical plunge grinding process. Other conclusions are follows. 1. The output from the developed contact sensor with thermocouple wires approximately has the liner relationship with surface finish 2. The sensitivity improves with an increase of measuring speed, peripheral speed of workpiece, and the system can obtain the surface finish at the measuring speed which is about two thousands times as large as that of surface roughness tester. 3. The sensitivity improves by use of thicker thermocouple wires of sensor. 4. It is necessary for this measurement system to apply the measuring load so large that thermocouple wires keep steady contact with workpiece surface. In addition, the sensitivity at 0.98 N in measuring load is higher than that at 0.29N.