Anti-lock brake system with traction slip control

Abstract

An anti-lock brake system with traction slip control comprising a pedal-actuated, auxiliary-force-assisted braking pressure generator (1) having a master cylinder (2), to which the wheel brakes (31, 32, 33, 34) are connected by way of main brake lines (62, 63) of auxiliary-pressure hydraulic pumps (21, 26), and of wheel sensors (S1, S2, S3, S4) and electronic circuits (28) for determining the wheel rotational behavior and for generating electric braking-pressure control signals. For the purpose of brake slip control, the signals control electromagnetically actuatable pressure-fluid inlet valves (24, 25, 29, 30) and outlet valves (22, 23, 35, 36) inserted into the pressure-fluid lines. The pistons (6, 7) of the master cylinder (2) are furnished with central control valves (10, 11) and the brake lines (62, 63) communicate with the motively driven pumps (21, 26) by way of supply lines (45, 46) in which non-return valves (38, 39) are arranged. A valve (87) is inserted into the one supply lines ( 45), through which pressure fluid is delivered into the brake circuits (62, 63) for the purpose of traction slip control. The portion of the supply line (45) interconnecting the pumps (21, 26) and the valve (87) communicates by way of a bypass line (95) with the main brake lines (62). Each pressure-relief valve (82) is interposed into the bypass lines (95) which permits the delivery of pressure fluid into the main brake lines (62) after a nominal pressure is exceeded, but which precludes pressure fluid flow in opposite direction. A pressure-fluid accumulator (76) is in communication with the bypass line (95) into which fluid is supplied by the pump (21) until attainment of the nominal pressure. The accumulator (76) also is in communication with the supply line (46) by way of a branch line (101).