Nabco Limited

Akira Matuo

Takeshi Kaneko

A fluid pressure control valve apparatus, including a main body in which an input opening is formed in communication with a master cylinder and an output opening is formed in communication with a wheel cylinder. A stepped bore in the main body communicates with the openings, the bore being enlarged in the direction towards the input side. A cover member is inserted into the input opening and a stepped piston sidably fits into the bore and extends between a through hole of the cover member and the output opening side of the bore. A path in the piston has one end communicating with the through hole of the cover member and another end communicating with the output opening side. A valve seat formed at the one end of the path and a valve body are arranged in a valve chamber formed in the through hole of the cover member. A valve spring urges the valve body toward the valve seat and a retainer member supports one end of the valve spring. A pre-loaded spring urges the piston in a direction to separate from the valve body. An annular thin projecting portion formed integrally with the main body at the input opening side projects outwards from the end of the cover member and the cover member is fixed to the main body by deforming the projecting portion towards the cover member. An outer circumferential portion of the retainer member is held between the deformed projecting portion and the cover member.

Fluid pressure control valve apparatus

A brake booster having separately formed valve bodies for the vacuum valve and the atmospheric valve, which minimizes an invalid portion of the operation stroke. There is provided a cylindrical inner member 800 air-tightly and slidably fitted in the internal bore of a hub portion 52 of a servo piston 50. The inner member 800 is biased backwardly by a spring 850. The inner member 800 has at its front end a valve body 510 of the vacuum valve 500. The rear end of the inner member 800 is caused to be abutted with the atmospheric air valve body 710 side of the atmospheric air valve 700 under the effect of force of the spring 850.

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Yokohama, Japan

Akira Matuo