Grinding method and grinding machine with controlled grinding force

A grinding method with controlled grinding force in rough grinding operation and finish grinding operation, said grinding method comprising:

• the process of detecting a grinding velocity and a grinding force during the rough and finish grinding operations,
• obtaining for each machining cycle a threshold force F.sub.0 and a grinding wheel sharpness coefficient K out of the detected rough and finish grinding velocities and the detected rough and finish grinding forces using the following equations (1), (2):
• ##EQU3## wherein:
• V.sub.r :
• detected grinding velocity in rough grinding cycle,
• V.sub.f :
• detected grinding velocity in finish grinding cycle,
• F.sub.r :
• detected grinding force in rough grinding cycle,
• F.sub.f :
• detected grinding force in finish grinding cycle,
• D:
• workpiece diameter,
• W:
• width of grinding,
• calculating rough and finish grinding force command values F.sub.r1, F.sub.f1 out of the threshold force F.sub.0, the grinding wheel sharpness coefficient K and target grinding velocities V.sub.r1, V.sub.f1 which have been preset, for rough and finish grinding using the following equations (3), (4):
• ##EQU4## obtaining the difference in signals between the detected grinding forces F.sub.r, F.sub.f and the grinding force command values F.sub.r1, F.sub.f1 for rough and finish grinding cycles respectively, and
• controlling each grinding wheel feeds in rough and finish grinding cycles in a manner to make said difference in signals become substantially zero and to make detected grinding forces F.sub.r, F.sub.f agree with said grinding force command values F.sub.r1, F.sub.f1 respectively.