Patent ID: 6164070
Filing Date: 2000-12-26
Classification: B60T

Abstract:
A hydraulic pressure type booster comprising:a hydraulic pressure source for generating hydraulic pressure;a reservoir for storing hydraulic fluid;an input shaft operated upon inputting power;a control valve operated by said input shaft;a power chamber, being shut off from said hydraulic pressure source and communicated with said reservoir when said control valve is not operated, and being shut off from said reservoir and communicated with said hydraulic pressure source when said control valve is operated, so that hydraulic pressure is introduced into said power chamber from said hydraulic pressure source;a power piston operated by hydraulic pressure in said power chamber, said control valve being disposed in said power piston;a collar engaged in a first hole formed in said power piston; anda valve seat member engaged in said first hole,said control valve including:a valve body which is slidably guided and supported by said collar;a valve supported by said valve body;a first valve seat, said first valve seat being formed in said valve seat member, said valve being seated to and unseated from said first valve seat, said valve being seated to said first valve seat so that said hydraulic pressure source and said power chamber are shut off from each other when said control valve is not operated, said valve being unseated from said first valve seat so that said hydraulic pressure source and said power chamber are communicated with each other when said control valve is operated; anda second valve seat is disposed in a cylindrical member connected with said input shaft, said valve being seated to and unseated from said second valve seat, said valve being unseated from said second valve seat so that said power chamber and said reservoir is communicated with each other when said control valve is not operated, said valve being seated to said second valve seat so that said power chamber and said reservoir is shut off from each other when said control valve is operated;wherein said power chamber is formed when a second hole in a housing is closed by a plug, andwherein at least two of said collar, valve seat member and plug are press-fitted into corresponding holes.