Improvement of form accuracy in internal grinding using a slender grinding wheel: Prediction of the suitable moment of the wheel retraction in the plunge internal grinding

An internal surface of a deep hole is finished by internal grinding. Although the grinding wheel is fed to the axial direction of the workpiecc with oscillation in the conventional internal grinding, the end of the wheel wears out. To prevent the intensive wheel wear, we proposed a new internal grinding method. In this method, the grinding wheel was fed to the radial direction and the plunge grinding was carried out by a slender grinding wheel. In this method, the grinding wheel should be retracted at the suitable moment to reduce the internal form error of the ground workpiecc. The main cause of the form error is elastic deformation of the grinding wheel, and the wheel runout is also an error factor. The form error of the workpiece was improved with considering two kinds of error factor in the plunge internal grinding with a slender grinding wheel. Furthermore, the profile of the grinding wheel was modified to shorten the grinding cycle time.