Hydraulic brake system with anti-skid system and traction control for a vehicle

Claim 1

A hydraulic vehicle brake system (10) with an anti-skid system and traction control, having a master brake cylinder (11) that generates a brake pressure, from which cylinder a brake line (13, 23) leads to at least one wheel brake cylinder (15), a pressure control valve assembly (31), connected to the brake line (13, 23), for pressure buildup, pressure holding and pressure reduction in the wheel brake cylinder (15), a return pump (41), driven by an electric drive motor (46), for pumping brake fluid out of the wheel brake cylinder (15) when the anti-skid system becomes operative and to pump brake fluid into the wheel brake cylinder (15) when the traction control becomes operative, a precharging pump (54) for drawing brake fluid from a supply tank (12) and pumping it to an inlet of the return pump 41 when traction control becomes operative, and a valve (56) is disposed in a line (55) that extends between the precharging pump (54) and a line (28) that leads from the pressure control valve assembly (31) to the inlet of the return pump (41), the return pump (41) and the precharging pump (54) have a common drive motor (46) and are driven simultaneously; and said valve (56) is embodied as a 2/2-way valve, which when the anti-skid system becomes operative prevents an exchange of brake fluid between the precharging pump (54) and the return pump (41), but when the traction control becomes operative enables the pumping of brake fluid from the precharging pump (54) to the return pump (41) when the pressure control valve assembly (31) is switched to pressure buildup.