Patent ID: 6334806
Filing Date: 2002-01-01
Classification: B24B

Abstract:
A machine tool for simultaneously grinding two pin portions of a rotating crankshaft, comprising:a bed; a main spindle and a tailstock mounted on said bed, that rotatably support the crankshaft around a center axis of journal portions of the crankshaft as a rotational axis; a first table movably provided on said bed in a first direction parallel to the rotational axis of the crankshaft; a first wheel head movably provided on said bed in a second direction perpendicular to the first direction, that supports a first grinding wheel; a second table movably provided on said bed in the first direction; a second wheel head movably provided on said bed in the second direction, that supports a second grinding wheel; a numerical control unit that respectively controls relative motions between a rotation of the crankshaft and a movement of said first wheel head and between the rotation of the crankshaft and a movement of said second wheel head; a memory provided in said numerical control unit, that stores pin portion data as a combination of the two pin portions to be simultaneously ground whose rotational phase are different from each other; a table memorized in said memory, that stores a corresponding relationship between the pin portion data and a variety of the crankshafts; and designation means for designating one of the crankshafts to be machined, wherein the respective two pin portions of the designated rotating crankshaft are simultaneously ground by said first and second grinding wheels in accordance with the pin portion data stored in said memory.