HYDRAULIC BRAKE SYSTEM WITH A PRIMING PUMP FOR MOTOR VEHICLES

摘要

In order to avoid difficulties occuring at low temperatures when the viscosity of the hydraulic fluid is high, in a brake system suitable for automatic braking, the invention proposes that, when an automatic braking operation takes place, hydraulic fluid is supplied by a pumping pump (11) located in such a position that it draws fluid out of the reservoir (2) and pumps it into the brake line (5) at a junction point as far from the master cylinder (1) as possible. This junction point is as close as possible to the suction side of the return pump (22). The large distance between the master cylinder (1) and the point where the pressure line (14) joins the brake line (5) makes it unnecessary to fit any additional throttle elements in order to prevent fluid flowing back into the reservoir (2). Only when the change over valve (24) on the suction side of the return pump (22) is closed after an automatic braking operation has ended is it necessary to reduce the residual pressure since the priming pump (11) continues to run. This reduction in residual pressure takes places automatically in the braking system proposed since the hydraulic connecting line to the master cylinder and hence to the reservoir (2) is open.