WORKPIECE MACHINING DEVICE

摘要

Provided is a workpiece machining device that has: a center drum that can rotate around a rotation shaft and has at least one first groove formed in the shaft direction in the outer peripheral surface; a carrier that has a holding hole into which a workpiece to be machined is inserted and held; an upper surface plate and a lower surface plate that can rotate around the rotation shaft in a state in which the carrier holding the workpiece is interposed between the upper surface plate and the lower surface plate; and at least one hook that is attached to the inner peripheral part of the upper surface plate and can move a tip part inserted into a first groove along the first groove. The center drum has at least one second groove formed in the shaft direction in the outer peripheral surface. The second groove has a different length than the first groove, and has a support surface that supports the hook from below at a position at which the upper surface plate is above the position at which the workpiece is machined. As a result, when the upper surface plate is stopped at a position that is above the position at which the workpiece is machined, the upper surface plate can be maintained at horizontal even when a force in the vertical direction acts on a grinding surface of the upper surface plate.