Computer-Aided Thread Grinding without Form Dressing with Monitoring System to Prevent Wheel Interference.

Abstract

A previous report proposed a computer-aided thread grinding method for generating helicoid without form dressing, using a standard-shaped grinding wheel independent of the final helicoid. The method uses a simple conical or plain wheel, without limitations of the diameter and base angle. The wheel axis is set three-dimensionally at the optimum computed angle of inclination. When the wheelthickness is large or the thread pitch is small, there is a risk of interference between the back of the wheel and helical surface opposing the helical surface being ground. When the grinding wheel is fed radially to the thread with a small thread pressure angle, there is also a risk of deformation of the helical surface generated. This report introduces a monitoring system to the original computer-aided thread grinding method, for protection against undesirable wheel interference, considering an axial displacement of the wheel and the maximum allowable displacement. The investigation shows that the monitoring system is effective to determine limits of thread dimensions without undesirable wheelinterference.