Cam grinding apparatus with means to maintain the grinding speed constant

摘要

A cam grinding apparatus has a base member, a rocking bar rockably mounted on the base member, a master cam shaft rotatably mounted on the rocking bar, and a drive motor for driving the master cam shaft in rotation. A cam shaft to be ground is supported by the master cam shaft so as to have the cam section thereof ground by a grindstone while being rocked by the rocking bar and rotated by the master cam shaft. There is provided at least one device for detecting the rotational angle of the drive motor and for detecting the phase angle of the rocking bar. The apparatus has a rotational speed command device responsive to output signals from the detecting for generating a step-like voltage waveform representing a desired rotational speed of the drive motor, and a rotational speed control device responsive to the step-like voltage waveform for controlling the rotational speed of the drive motor so that the circumferential speed of the cam section of the cam shaft at the contact point between the cam section and the grind stone can be kept substantially constant.