To provide a workpiece gripping device which eliminates offset of a chuck arranged inside a spindle to the extent possible without increasing production costs of an automatic lathe, the offset sometimes occurring at the chuck during rotation of the spindle.
The workpiece gripping device 10 is comprised of the cylindrical chuck 16 having an openable/closable gripping portion 14, a cylindrical working member 18 for housing the chuck 16 in a relatively movable manner along an axial direction, and the cylindrical spindle 12 for housing the working member 18 in a relatively movable manner along the axial direction. A cylindrical spindle 32 of the working member 18 has an outer peripheral surface 32c which has a plurality of projected surfaces 44 (46) dispersively arranged thereon and faces the spindle 12, and therefore the working member is slidably abutted and borne on a spindle inner peripheral surface 12a partially by the projected surfaces 44 (46). A cylindrical body 20 of the chuck 16 has an outer peripheral surface 20c which has a plurality of second projected surfaces 62, 64 dispersively arranged thereon and faces the cylindrical main body 32 of the working member 18, and therefore the chuck is slidably abutted and borne on an inner peripheral surface 32b of the cylindrical main body of the working member 18 partially by the second projected surfaces 62, 64.
SASE YOSHIICHI
Jun Tsuruta
Masaya Nishiyama
Higuchi Souji