CAP SEAL STRUCTURE IN RESERVOIR TANK FOR MASTER CYLINDER

摘要

A reservoir tank includes a cap, a strainer, and a cap seal which is attached to the cap so as to prevent hydraulic fluid in the reservoir tank from leaking out. The cap seal is integrally formed with a cylindrical projection which is adapted to be pressed in resilient engagement with the outer periphery of the strainer, so that an inner space within the strainer defined by the inner side of the cap, the cap seal, the wall of the strainer, and the surface of the hydraulic fluid is separated by the projection from an outer space defined by the wall of the reservoir tank, the wall of the strainer and the surface of the hydraulic fluid. A tip of the projection of the cap seal is lower than the lower end of a thread portion of the cap when the cap engages with the reservoir tank. Therefore, hydraulic fluid adhering to an inner part of the cap and the cap seal does not drip and adhere to the thread portion of the cap. Furthermore, there is provided at the outer periphery of the strainer a passage comprising radial and vertical channels through which the outer space is communicated with the inner space, so that air retained in the outer space can escape into the inner space.