動圧を利用した湿式研削における砥石摩耗のインプロセス測定 １ 測定原理

Abstract

In order to realize precision grinding, in-process measurement of grinding wheel wear is required. No method for the inprocess measurement of the wear of a grinding wheel with high accuracy in wet condition has been studied because grinding fluid causes a difficulty in measurement. In this paper, a measurement method by hydrodynamic pressure around the grinding wheel caused by grinding fluid is proposed for measuring the wear amount of a grinding wheel. A pressure sensor is set around a grinding wheel. The grinding fluid is supplied to the gap between the grinding wheel and the sensor. Because the viscous fluid is dragged into the clearance between a grinding wheel and a pressure sensor, the hydrodynamic pressure is generated. The relation among hydrodynamic pressure, gap distance and rotational frequency is examined. With the increase in gap distance between the sensor and the disk, the hydrodynamic pressure decreases. By using the measured hydrodynamic pressure, the distance between the sensor in the gap and the grinding wheel can be calculated so that the grinding wheel wear can be measured. The maximum error in using grinding wheels is less than 2 μm in dispersion. By calibrating the relation between hydrodynamic pressure and a gap distance, the measurement can be made towards the actual grinding wheel.