US 4,904,026 AGranted

Brake system

AssigneeRobert Bosch GmbH

InventorsWolfgang Bernhardt, Michael Tischer

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Abstract

A brake system having a master brake cylinder with at least one piston in a stepped bore in which the piston is acted upon at one end by a piston rod and on the other end defines a pressure chamber, from which an outlet or a brake line leads to wheel brake cylinders of at least one brake circuit. The pressure chamber, or the brake line discharging from this pressure chamber communicates on the one hand with a compensation chamber and on the other with an annular chamber, the volumes of both these chambers being variable contrarily by movement of the piston. The connection between the pressure chamber and the compensation chamber is interrupted by a valve, and a connection is then established with a fluid reservoir. A suitable amount of fluid can then be transported from this fluid reservoir into the compensation chamber by means of a return pump.

Claims20

Dependent claims

A brake system comprising a master brake cylinder, a cylinder housing (1), a stepped bore (2) in said cylinder housing, a piston (10) in said stepped bore, a piston rod (7) acted upon on one end by a brake pedal, said piston rod contacts one end of said piston, a slide ring (12) surrounding said piston (10), a ring flange (25) on said piston, a variable annular chamber (26) surrounding said piston between said slide ring (12) and said ring flange, a fluid return pump;

a compensation chamber (30) which surrounds said piston and communicates directly with a fluid outlet of said fluid return pump, a pressure chamber (22) acted on by said piston in said stepped bore, an outlet connection (36) from said pressure chamber to a brake line (37) in which said brake line leads to wheel brake cylinders of at least one brake circuit, said pressure chamber (22) communicates on one end with said annular chamber (26) and said brake line (37) communicates with a compensation chamber (30), the volumes of said pressure chamber (22) and said annular chamber (26) being variable relative to one another by a movement of said piston (10), and a fluid switching valve (40) connected with said brake line (37) between said pressure chamber (22) and said compensation chamber (30), by way of which in a second position valve fluid flow is blockable.

a fluid return pump (46) connected to said compensation chamber, a pressure chamber (22) acted on by said piston in said stepped bore, an outlet connection (36) from said pressure chamber to a brake line (37) which leads to wheel brake cylinders of at least one brake circuit, said pressure chamber (22) communicates on one end with said annular Chamber (26) and said brake line (37) communicates with a compensation chamber (30), the volumes of said pressure chamber (22) and said annular chamber (26) being variable relative to one another by a movement of said piston (10), a fluid switching valve (40) connected with said brake line (37) between said pressure chamber (22) and said compensation chamber (30), by way of which in a second position valve fluid flow is blockable, and said fluid switching valve (40) being switchable to a third switching position which blocks the connection between the pressure chamber (22) and the compensation chamber (30) while connecting said pressure chamber (22) via said fluid return pump (46) with said compensation chamber (30).

Dependencies are inferred from the claim text.