MANUFACTURE OF CLUTCH PISTON

摘要

PURPOSE: To finish a sizing surface at a high precision by forming clearance groove on the sizing surface of a preform forged product, pressing the preform forged product in the axial direction and fluidizing pads to the clearance groove. CONSTITUTION: A columnar cut blank is formed by cutting a steel round bar material to a specific length. A shot peening is applied to the cut blank. The cut blank is heated and formed to a forged blank by the forging formation. The forged blank is formed to an intermediate blank to from the clearance groove 6 on the sizing surface 5. A through hole 10 is worked to the intermediate blank by a blanking process to obtain the preform forged product 21. The preform forged product 21 is clamped and pressed by a sizing device to forme a sizing product. At that time, the pads are fluidized to the clearance groove 6 to finish the sizing surface 5 at a higher precision. The man-hour of succeeding cutting process can be reduced.