Development of a grinding force dynamometer based on wheel shaft deflection for a grinding center

In order to develop a practical grinding force inproccss measuring system for a grinding center, dynamometer based on wheel shaft deflection is proposed in this paper. The dynamometer detects the elastic deflection of the grinding wheel shaft due to grinding by 3 eddy current non-contact micrometers arranged around the wheel shaft. The grinding force measuring characteristics are compared between the dynamometer and piezoelectric dynamometer fixed on the machine table with the workpiece. The grinding force is measured in contour grinding of hardened steel on a grinding center using a CBN wheel. Main conclusions obtained are as follows: (1) It is made clear that the dynamometer has the practical performance for measuring grinding force on the grinding center. (2) In the case of measuring grinding force by the piezoelectric dynamometer, the output values might be superposed by noise, which is caused by heat conducted through the workpiece into the dynamometer. (3) Even if the radius ratios in sections to be ground are the same, there exist differences of grinding forces, and it means that the amount of depth of cut is possibly influenced by the grinding heat.