PURPOSE: To shorten working time, to ease machining work, and to stabilize the quality of work by intermittently sending a curved raw material, measuring the dimension of grinding parts in advance of machining, figuring out grinding conditions based on this measurement, grinding the material with a grinding wheel under the conditions thus figured out, measuring the ground parts after the grinding, and correcting these grinding conditions based on grinding wheel wear data obtained through this measurement.

CONSTITUTION: Curved raw material is supplied by a raw material supplying mechanism 10 to a clamping mechanism 3 of a sending mechanism 1 one after the other and is sent intermittently by the sending mechanism 1. In advance of machining, the dimension of each part to be ground of this raw material is measured by a shape measuring means 5, and, based on these measurement data, the grinding conditions are figured out by the a computing means 6. Based on these grinding conditions, respective working heads H1 to H11 grind the grinding parts of the curved raw material in turn by using each grinding wheel. After the grinding work, the dimension of the ground parts of the curved raw material is measured by a finish shape checking means 8, and, the grinding wheel wear data are computed from these measurement data by the finish shape checking means 8. In addition, based on these wear data, the grinding conditions are corrected by a wear correcting means 9 one by one.