Cam grinding machine with workpiece speed control

摘要

A cam grinding machine is provided wherein a wheel head is fed toward a rocking table carrying a work spindle so as to grind a cam roughly in a first step and finely in a second step successive thereto, and a speed-switchable motor is operated in such a way as to drive the work spindle and the rocking table at a fast speed in the first step and at a slow speed in the second step. The grinding machine is further provided with a motor control circuit which is arranged to switch the motor from the fast speed to the slow speed, with a delay of time that is required for the cam to rotate at least one revolution after the switching of the grinding step from the first step to the second one, so that an excessive infeed caused by the spring-back action of the cam can be reduced.