TABLE OF CONTENTS Grinding processes considered up to this point are of the fixed-feed type, with the depth of cut or infeed rate being a controlled input parameter. Forces developed between the wheel and the workpiece cause elastic deflection of the grinding system, such that the true infeed is less than the input infeed. Changes in the controlled infeed rate during the grinding cycle, such as at the beginning and end of a grinding cycle (spark-out), are accompanied by grinding transients which depend mainly on the stiffness of the grinding system and the forces developed. Grinding transients of this type are discussed in Chapter 12.
While most grinding operations are of the fixed-feed type, some machines operate with controlled normal force instead. In this case, the normal force is input to the process, and the infeed or removal rate is an output or consequence of the process. Controlled-force grinding was originally introduced almost 50 years ago [60], and it has been extensively studied [60 67]. One particular advantage of controlled-force grinding is that it minimizes transient effects at the start of a grinding cycle, which is especially important for 'soft' grinding systems having low stiffnesses [62]. For this reason, controlled-force grinding was often selected for precision internal grinding, since the shaft supporting the grinding wheel in such machines limits the stiffness of the grinding system.
The effect of the normal force of the removal rate in controlled-force grinding with conventional abrasive wheels can be analyzed from the force relationships in section...
