| 摘要 |
The plastic piston body(16) comprises a circumferential wall(18) and two closed end faces(17a,17b) and is made of two identical beaker shaped body halves(32a,32b). The body halves are coaxially aligned with each other with the open ends facing each other and connected by a material joint at the interface(33) between them. The material joint between the two injection molded body halves(32a,32b) is produced by welding, preferably by friction welding. The outer surface of the circumferential wall(18) has axially spaced annular collars(26a,26b), pairs of which form annular recesses(25) for holding a sealing ring(23) coaxial with the piston body(16). Each seal is snap fitted into a recess. The circumferential wall of the complete piston body has no holes and near the end walls(17a,17b) has at least one annular recess for holding an annular driving component(28). Independent claims are included for: (1) a method for manufacturing the piston in which two identical beaker-shaped body halves(32a,32b) are injection molded in plastic, aligned coaxially with each other with the exposed end faces(37) of the circumferential side walls facing each other and then joined together with a material connection at the mating interface(33) during contact between the body halves and/or after contact with each other; (2) a valve for fluid stream control incorporating the claimed control piston. |
