Patent ID: 6679503
Filing Date: 2004-01-20
Classification: B23B,Y10T

Abstract:
Chuck unit for machine tool, capable of holding a workpiece, being installed on a spindle rotatably supported, comprising: a main body being free to rotate and drive with an axial center as its center; two or more sliding members provided on said main body, being free to move in a radial direction with respect to said axial center of said main body through sliding member driving means; workpiece holding member provided on said each sliding member, being capable of moving together with said sliding member; a plurality of workpiece holding rods provided on said workpiece holding member, being free to move and drive in said radial direction with said axial center as its center; said workpiece holding rod provided being free to move and drive by a fluid cylinder driving means; said fluid cylinder driving means having a cylinder formed in said each workpiece holding member; said workpiece holding rod being engaged with said cylinder being free to move and reciprocate; member moving mechanism provided between said sliding member and said workpiece holding member such that said respective workpiece holding members are free to independently move and drive in said radial direction with said axial center as its center by said member moving mechanism; said member moving mechanism having a adjustable screw mechanism rotatably provided between said sliding member and said workpiece holding member such that said workpiece holding member is free to move and drive with respect to said sliding member in said radial direction with said axial center of said main body as its center by operating said adjustable screw mechanism; said adjustable screw mechanism having a screw operation portion, operable by a rotating operation jig, rotatably provided at said machine tool, on an outer periphery side of said chuck unit; and a workpiece end face abutting means provided at said main body, being free to move, drive and fix in said axial direction of said main body, and a workpiece end face abutting face formed at an top end of said workpiece end face abutting means at right angle with respect to said axial center direction of said main body.