| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide the shape of a piston capable of preventing the cracking on a clutch pressing part 22 in pressing or mold releasing, and the breakage of press mold, in the piston 1 for an automatic transmission wherein a piston main body 2 molded by sheet metal press, is mounted, the piston main body 2 has the circular clutch pressing part 22 for pressing a clutch plate 8, and the clutch pressing part 22 integrally has an inner peripheral wall 22a, an end wall 22b and an outer peripheral wall 22c, and has the shape projecting in the clutch plate direction. <P>SOLUTION: One or both of the inner peripheral wall 22a and the outer peripheral wall 22c of the clutch pressing part 22 are formed into a conical taper face in sheet metal press, whereby the internal stress generated in pressing and the sliding resistance generated in mold releasing can be reduced. <P>COPYRIGHT: (C)2005,JPO&NCIPI</p> |
