Abstract:
The invention relates to a hydraulic vehicle brake system with a master cylinder, with two brake circuits (I, II), with wheel brakes connected to the brake circuits (I, II), and with a wheel slip regulator device disposed between the master cylinder and the wheel brakes, which device has at least one brake pressure modulation valve device and at least one high pressure pump, and with a pump unit associated with this high pressure pump. In the automatic braking operation by means of at least one of the high pressure pumps, the pump unit is used for supplying hydraulic fluid to the high pressure pump. The pump unit has a low pressure pump in the form of a gear pump. To limit the pressure at an outlet of the low pressure pump at least one return flow conduit is provided between this outlet and an inlet, which conduit, in a manner according to the invention constitutes a throttle by which the choice of its cross section, which throttle is for controlling at least one return flow which increases with increasing pressure at the outlet and as a result achieves the pressure limiting. The hydraulic vehicle brake system can be used for cars, minibuses, and small trucks.
Abstract:
A vehicle hydraulic brake system having brake pressure modulation valve assemblies, between a dual-circuit master cylinder and wheel brakes of vehicle wheels. The pump device is embodied as a low-pressure pump with the brake pressure modulation valve assemblies be assigned a first and second return pump and that in the automatic braking mode the first pressure chamber is made to communicate with a first return pump and the second pressure chamber is made to communicate with the second return pump, on the inlet side in both cases. The low-pressure pump, in the automatic braking mode, generates charge pressure for the return pumps that is substantially below a maximum brake pressure, and the return pumps generate the maximum projected brake pressure and serve, in the additionally possible anti-lock mode, to return pressure fluid from the wheel brakes to the master cylinder. The vehicle brake system is an inexpensive low-pressure pump that offers a high possible capacity of the return pumps in the automatic braking mode.