US 6,637,201 B2Granted

Master cylinder

AssigneeBosch Braking Systems Co., Ltd.

InventorsJunichi Hirayama, Kunihiro Chiba, Shusaku Chiba

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Abstract

A throttle valve mechanism having a throttle function of throttling the flow of working fluid from a pressure delivering chamber to a reservoir at the operation time of the piston of a master cylinder, a valve function of allowing the working fluid to flow from the reservoir to the pressure delivering chamber by opening the valve at the return time of the piston, and a relief valve function of allowing a large quantity of working fluid to flow from the pressure delivering chamber to the reservoir is disposed in a fluid passage for connecting the master cylinder to the reservoir. The master cylinder can decrease the quantity of working fluid flowing to the reservoir at the time of operation start of the master cylinder, and can respond to the fluctuations in fluid pressure quickly when a traction control unit, an automobile stability control unit, etc. are released.

Claims5

Dependent claims

A master cylinder comprising:

a cylinder body;
a piston disposed slidably in a cylinder bore formed in said cylinder body;
a pressure delivering chamber defined by said piston and said cylinder body;
a fluid passage connecting said pressure delivering chamber to a reservoir for resupplying a working fluid to said pressure delivering chamber;
an output port connecting said pressure delivery chamber and said fluid passage for discharging a working fluid pressurized at the operation time of said piston from said pressure delivery chamber;
and
a throttle valve mechanism disposed in said fluid passage and having a throttle function of throttling the flow of a working fluid from said pressure delivering chamber to said reservoir at the operation time of said piston, a valve function of allowing the working fluid to flow from said reservoir to said pressure delivering chamber by opening the valve at the return time of said piston, and a relief valve function of allowing the working fluid to flow from said pressure delivering chamber to said reservoir.

4 more elements

Dependencies are inferred from the claim text.