Sealing device

Abstract

A sealing device (1) in which, even when a seal member (6) having a core metal (4) and a sealing section (5) is fitted on a piston member (3) that axially reciprocates in a bottomed circular cylinder (2), force required for the fitting can be suppressed to a low level and as a result the core metal (4) of the seal member (6) is not deformed. The wall thickness of a circular cylindrical portion (42), fitted on the piston member (3), of the core metal (4) is reduced to provide the circular cylindrical portion with spring properties. Alternately, slits (44) are equally arranged on the circumference of the circular cylindrical portion (42) of the core metal (4) or, alternatively, the circular cylinder portion (42) is constructed from claws (45).

Description

technical field [0001] The present invention relates to a sealing device which ensures sealing performance by providing a sealing element on a piston element which is controlled by oil pressure to reciprocate in a cylinder. Background technique [0002] Due to the recent multi-stage trend of automatic transmissions such as ATs and CVTs for automobiles, there is a space constraint in the axial direction in the FF type (front-wheel drive type), especially in large-capacity ATs, BPS (Bonded Piston Seal) has a large size trend. In the prior art, in order to vulcanize and bond the sealing part to the piston element, when the size of the BPS is increased, the mold for vulcanization and bonding is also increased in size, so there is a problem that the manufacturing cost increases. [0003] As a solution to this problem, Patent Document 1 below proposes to separate only the sealing portion from the piston element, and to fit the sealing element obtained by vulcanizing the sealing p...

AI Technical Summary

Problems solved by technology

[0004] However, as shown in FIG. 9, in order to install the sealing member 101 on the piston member 102, the core 104 bonded with the sealing portion 103 is fitted to the piston member 102. Since the thickness t of the core 104 0 The thickness of the flange part 104a and the cylindrical part 104b is the same, the fitting installation force when fitting the core 104 to the piston element 102 is large, and the fitting installation force itself has a large deviation, so the core 104 is deformed The problem

[0005] In addition, in order to control the deviation of the fitting and mounting force, it is necessary to strictly control the tolerance of the fitting dimension of the piston element and the core, so it is necessary to add processing steps such as turning, and the processing accuracy must also be improved, which will cause the problem of increased manufacturing costs.

In addition, when the fitting and mounting force is large, the output power of the auxiliary equipment for fitting the core to the piston element also increases, and there is also a problem that the manufacturing cost increases.

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