Precision Grinding Cycles

Abstract

Grinding cycle is the term used to designate the input parameters imposed on a grinding machine to produce the desired output. Those machine input parameters—viz., wheel speed, work speed, feedrate, etc.—were discussed in Chapter 1 and are illustrated in Fig. 1.2. The output variables on the finished workpiece—viz., size, taper and form errors, surface finish deviations, thermal damage and cycle time—are also illustrated in Fig. 1.2. The selection of the proper combination of machine input parameters to produce the desired output often requires considerable expertise, especially when high-quality output is desired in a short cycle time. The grinding of the bore of automotive valve lifters at high production rates to stringent requirements on size, taper and surface finish illustrates the difficulty in obtaining fast production cycles while maintaining close tolerances. A reduction in cycle time of 1 second is worth about $1,000,000 per year. However, the quality deteriorates if the cycle is sped up beyond a certain limit. This chapter deals with the various factors governing the grind cycle input parameters and their relation to output quality.