| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a technology for forging, which can form an inner spline without forming a prepared hole when forging a product having a gear and the inner spline. <P>SOLUTION: In a method for forging, a forging step S1 includes a cold forging step S40 in which a workpiece W that is configured by forming a rough gear R of a parking gear 4 in the outer periphery of a columnar member in a hot forging step S10, is shaped into a product shape by cold forging. The cold forging step S40 includes: a shaping step S41 of finishing the rough gear R into the parking gear 4 and also shaping a bottomed recess and the inner spline 5 formed in the inner periphery of the recess in the workpiece W by extrusion; and a punching step S42 of punching a waste shaft X generated in the bottom of the recess to obtain a product shape of a pulley part 2 by extrusion. <P>COPYRIGHT: (C)2012,JPO&INPIT</p> |
