초록 ▼

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. Th

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. The anti-lock arrangement creates the possibility that in the anti-lock mode, for instance in travel on an icy road, rear wheel brake pressures may be higher than front wheel brake pressures, to improve the braking action.

대표청구항 ▼

[ We claim:] [1.] A hydraulic brake system for a vehicle comprising a dual-circuit master cylinder, two brake circuits (I, II) in diagonal configuration for two front wheel brakes (7, 8) and two rear wheel brakes (11, 12), an anti-lock system built into the brake circuits in which each brake circuit

[ We claim:] [1.] A hydraulic brake system for a vehicle comprising a dual-circuit master cylinder, two brake circuits (I, II) in diagonal configuration for two front wheel brakes (7, 8) and two rear wheel brakes (11, 12), an anti-lock system built into the brake circuits in which each brake circuit has one return pump (32, 33) with an inlet and an outlet and one first (28, 29) and one second (30, 31) electrically controllable valve that are normally open, the first valve being disposed between the master cylinder and a respective front wheel brake and the second valve communicating with a respective rear wheel brake, the second valves (30, 31; 30b, 31b; 30d, 31d) are disposed between the rear wheel brakes (11, 12) and the master cylinder (2), and that the rear wheel brakes (11, 12) communicate via throttles (35, 36) with the inlet to each of the return pumps (32, 33), and via check valves (37, 38) that open in a direction of the inlet of a respective return pump (32, 33), said check valves (37, 38) are placed in series with each throttle (35, 36), and a second check valve (49) in the input line to the pump (32, 33), said hydraulic brake system having a control unit (16), which in normal braking operation is used to close at least one of said second valves (30, 31; 30b, 31b; 30d, 31d) as soon as a preselected brake slip magnitude is reached by a respective rear wheel.