Abstract: The invention relates to a hydraulic brake system of a vehicle comprising one wheel brake valve preceding each wheel brake cylinder and one return feed pump connected parallel to each of the wheel brake valves and connected to the suction sides of the wheel brake cylinders. For anti-lock control, the return feed pump is put into operation, and by clocked triggering of a wheel brake valve of a vehicle wheel that is tending to lock, the brake fluid pressure in the wheel brake cylinder of this vehicle wheel is modulated. To realize a traction control device, the invention sets forth a switchover valve in a brake line from the master brake cylinder to the wheel brake cylinder of a driven vehicle wheel.

Abstract: The invention is based on a dual-circuit anti-lock vehicle brake system (10) with a tandem master cylinder (12), a switchover valve (14) following the latter, a brake pressure modulation valve assembly (18, 20) that has a brake pressure buildup valve (18) and a brake pressure reduction valve (20) for each wheel brake cylinder (16), and a return pump (24). To enable building up brake pressure rapidly for vehicle dynamics control, the invention proposes one additional pump (28) in each brake circuit (I, II), whose intake side is connected directly to the master cylinder (12) and which feeds in the direction of the wheel brake cylinders (16) connected to to this brake circuit (I, II). As a result, a brake pressure buildup is possible in each wheel brake cylinder (16), even when the master cylinder (12) is not actuated, which buildup can be modulated for individual wheels in a manner known per se.

Abstract: A hydraulic brake system for a vehicle with an anti-lock arrangement operable by wheel brake pressures are individually variable in front wheel brakes and rear wheel brakes, connected to diagonal brake circuits, of a four-wheeled vehicle, in order to reduce or eliminate a threat of wheel locking. The anti-lock arrangement has at least one return pump per brake circuit. The anti-lock arrangement is equipped with a total of four electrically controllable valves. In each of the brake circuits I, II there is one first valve between the master cylinder and a front wheel brake and one second valve between the master cylinder and the rear wheel brake. All the valves are embodied as normally open valves and are electrically closable. Inlets of each of the return pumps communicate directly with the respective front wheel brakes and indirectly with the rear wheel brakes through throttles. Check valves that open toward the inlets of the return pumps are provided in series with the throttles.

Abstract: The brake system includes a first and a second diagonal brake circuit distribution. A first 2/2-way valve is located in a first line between a master cylinder and a wheel brake cylinder of the front axle. On the wheel brake side, a second line, in which a second 2/2-way valve is disposed, branches off from the first line, leading to a wheel brake cylinder of the rear axle. A third line originates between the second multiposition valve and the wheel brake cylinder and has a pump, with which pressure fluid can be fed from the wheel brake cylinders to the master cylinder. Brake force distribution that is dependent on the dynamic axle load shifting, and within limits, individual-wheel brake pressure control if wheel locking threatens, are thus made possible.

Abstract: Only the brake pressures at the front wheels are controlled individually. For this purpose, the speeds of rotation of the front wheels are detected. The brake pressure at the rear wheels is controlled jointly for both rear wheels and no detection of the speed of rotation is provided at the rear wheels. However, the brake line leading to the rear-wheel brakes has inserted into it a 2/2-way valve which can be moved into its shut-off position as a function of the brake-force distribution determined as a function of the loading and then holds the rear-axle brake pressure constant.