US 4,568,130 AGranted

Vehicle wheel controlled anti-brake lock braking system

AssigneeRobert Bosch GmbH

InventorHeinz Leiber

Life of this patent

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Abstract

To prevent loss of brake fluid in a closed brake fluid circuit including an automatic brake anti-lock system having an automatic brake anti-lock evaluation stage (ABS), and brake fluid control valves (9-12; 40-42) controllable by the ABS stage for pressure build-up, pressure maintenance, and pressure drop, respectively, a feed valve (15, 43) is provided coupled to a source (6, 8) of pressurized brake fluid, preferably to a pilot valve which is operated by the operator brake pedal in a pilot valve chamber (6), the feed valve being hydraulically operatively connected to the pressure inlet connections of the control valve means, the feed valve being electrically connected to the ABS evaluation stage and operated, upon energization thereof, to supply pressurized brake fluid when the ABS unit responds, indicative of skidding or incipient locking of a brake. A hydraulic choke (15a, 43a) is interposed in the connection between the feed valve and the respective control valves (9-12; 40-42). To maintain separation of braking circuits (I, II), a distributor unit with check valves is provided so that pressurized brake fluid is separately fed to the respective brake circuits.

Claims7

Dependent claims

Vehicle wheel controlled anti-brake lock braking system having

an anti-brake lock system evaluation stage (ABS) coupled to receive wheel operation signals (W);
a source (6, 8) of pressurized brake fluid;
a main brake cylinder (1) having dual output brake fluid circuits (I, II) emanating therefrom, each brake fluid circuit including at least one brake fluid control valve means (9, 10;
11, 12;
40, 41, 42) controllable in at least two modes:
(1) increase of brake fluid pressure level affecting brake fluid pressure in at least one wheel or an axle of the vehicle,
(2) drainage of brake fluid to drop brake fluid pressure affecting at least one wheel or an axle of the vehicle,
a feed valve (15, 43) coupled to the source (6, 8) of pressurized brake fluid and to the pressure input connections of the brake fluid control valve means (9, 10, 11, 12;
40, 41, 42), said feed valve being operatively connected to and controlled by the automatic anti-brake lock system evaluation stage (ABS) to supply pressurized brake fluid thereto;
and a hydraulic choke (15a, 43a) interposed in the connection between the feed valve (15, 43) and the respective control valve means (9-12;
40-42);
wherein the feed valve (15, 43) is connected to the main brake cylinder (1) to receive pressurized brake fluid therefrom,
and the main brake cylinder is connected to receive pressurized brake fluid from said source (6, 8).

10 more elements

Dependencies are inferred from the claim text.

Facts

Application: 06/620,458Filed 14 Jun 1984
Granted: 4 Feb 1986
Term ends: Not estimatedThe source records don’t support an estimate.

Classification7 codes

B60T 13/14
The fluid being liquid: using accumulators or reservoirs fed by pumps
B60T 8/1764
Brake regulation specially adapted to prevent excessive wheel slip during vehicle deceleration, e.g. ABS: regulation during travel on surface with…
B60T 8/3615
Including a pilot valve responding to an electromagnetic force: electromagnetic valves specially adapted for anti-lock brake and traction control…
B60T 8/445
Co-operating with a power-assist booster means associated with a master cylinder for controlling the release and reapplication of brake pressure…:…