Patent ID: 8851957

Claim:
A grinding method of a multifunction grinding machine grinding predetermined positions of a workpiece by a plurality of grinding wheels during driving said workpiece by driving pins contacting with said workpiece, said multifunction grinding machine including a pair of spindle equipment, each of said pair of spindle equipment includes a centering member accommodated in a spindle housing and shifted along a spindle rotational axis in relative to said spindle housing, and a driving pin mounted on a spindle in said spindle housing to be rotated around said spindle rotational axis at a position of a predetermined distance from said spindle rotational axis and projected along said spindle rotational axis direction, said pair of spindle equipment are disposed in a way that said centering members are oppositely faced each other; a grinding wheel at one side grinding one end portion of said workpiece and; a grinding wheel at the other side grinding the other end portion of said workpiece, said grinding method comprising: a holding step to hold said workpiece by said centering members of said one pair of spindle equipment; a shifting step to one direction to shift simultaneously both of said centering members to one side of said spindle rotational axis to a position where said driving pin of said spindle equipment at one side can drive said workpiece and said driving pin of said spindle equipment at the other side cannot drive said workpiece in maintaining to hold said workpiece by said two centering members; a facing step to said other grinding wheel to face said grinding wheel at the other side to the other end portion of said workpiece; a grinding step for the other end portion to rotate said workpiece by rotating said driving pin of said spindle equipment at one side, and to grind the other end portion of said workpiece by sliding said grinding wheel at the other side faced to said workpiece in relative to said workpiece; a shifting step to the other direction to retract said grinding wheel at the other side from said workpiece, to stop the rotation of said driving pin of said spindle equipment at one side, and to shift simultaneously both of said centering members to the other side of said spindle rotational axis to a position where said driving pin of said spindle equipment at the other side can drive said workpiece and said driving pin of said spindle equipment at one side cannot drive said workpiece; a facing step to said one grinding wheel to face said grinding wheel at one side to one end portion of said workpiece; and a grinding step for one end portion to rotate said workpiece by rotating said driving pin of said spindle equipment at the other side, and to grind one end portion of said workpiece by sliding said grinding wheel at the one side faced to said workpiece in relative to said workpiece.