Patent ID: 6467266
Filing Date: 2002-10-22
Classification: B60T

Abstract:
A brake booster comprising at least a housing, an input shaft which is actuated by an operational input applied through an operation of brake operating means, and a control valve which is disposed in said housing and is operated by an actuation of said input shaft to regulate a pressure of a pressure source according to the operational input of said brake operating means to output a regulated pressure, whereinsaid control valve has at least a first valve element and a second valve element, said first valve element is moved relative to said second valve element by the actuation of said input shaft and is subjected to an output pressure of said control valve in a direction opposite to an actuating force of said input shaft, and said second valve element is fixed to said housing, said brake booster further comprising operational input converting means which is disposed between said input shaft and said first valve element and at least partially displaced by the input of said input shaft to convert the operational input of said brake operating means to actuating force for operating said first valve element according to the operational input, and characteristic varying means for allowing input and output characteristics to be varied, said characteristic varying means having a pressure regulating valve which regulates the output pressure of said control valve or the pressure of said pressure source to output the regulated pressure that acts on said first valve element in a direction opposite to the actuating force of the input shaft.