| Usually, crankshafts have to be ground using several positioning and clamping operations because of the differences in axes orientations of the journal and the connecting rod journal. In the operation, there are many problems such as relatively excessive errors of positioning and clamping, low productivity, large investment of equipment and workshops, long period in the adjustment of the machine tool and fixtures and poor surface finish of the ground part etc. From analying the mentioned shortcomings, a new grinding principle named 2-coordinate linkage grinding is studied, which allows both connecting rod journal and journal of the crankshaft to be ground in only one positioning and clamping operation. Theory of 2-coordinate linkage grinding and some key techniques in the realization and application of this new method are focused on.A mathematical model of machining in the 2-coordinate linkage grinding is established according to the principle of constant rotated speed of grinding. Taking the problems of the constant rotated speed model into carefully considered, the mathematical model of removal rate of grinding of 2-coordinate linkage is presented. Base on this model, errors of the variation of diameters of grinding wheel, motion and grinding forces.The NC interpolation algorithms of the special curve, which is formed the rotational motion of crankshaft and to-and-fro motion of grinding wheel in the grinding, and a corresponding controlling strategy of interpolation are studied.Based on theoretical studies mentioned above, preliminary researches on NC machining simulation concerning the machining process are carried out. The simulation of machining state in the grinding is studied to have a check on the validity of machining state. Programming a module of errors analysis to deal with repeated and complicated calculations. According to FANUC-Oi CNC system, programming a post processing module to create the NC code of product machining.
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