PISTON FOR AUTOMATIC TRANSMISSION

PROBLEM TO BE SOLVED: To prevent the occurrence of damage in a rubber-like elastic body when fitting a seal ring to a piston body, when assembling a piston, in the piston of a type of fitting by separately manufacturing the piston body and the seal ring. SOLUTION: This piston 11 has the seal ring 31 suitable for a shoulder step part 22 of the piston body 21 having an end surface 23 in the axial direction and a cylindrical peripheral surface 24. The seal ring 31 has a metallic ring 32 by press molding and the rubber-like elastic body 41 laid on the metallic ring 32. The metallic ring 32 has a cylindrical part 33 suitable for the cylindrical peripheral surface 24 and a plane part 34 integrally molded in the cylindrical part 33 and opposed to the end surface 23 in the axial direction. A metallic claw 36 brought into close contact with the end surface 23 in the axial direction of the shoulder step part 22, is integrally molded in an end part in the radial direction of the plane part 34. A metal exposed surface 37 uncovered with the rubber-like elastic body 41 is arranged as a pressing object part in assembling on an outside end surface 34a of the plane part 34. COPYRIGHT: (C)2010,JPO&INPIT