ANTI-LOCK BRAKING FOR A VEHICLE WITH STEERABLE WHEELS

摘要

In an anti-lock braking system for a commercial road vehicle trailer with compressed air brakes and including a self-steer axle with such brakes, an electronic control unit ECU 16 selectively controls respective brake pressures to each side of another braking axle according to differential rolling surface adhesion to reduce skidding by way of respective pressure modulators 6L, 6R. The output pressures from these modulators are additionally applied directly via an axle control valve 15 to brake actuators of the wheels of the self-steer axle and the axle control valve has means Fig 2 which responds to a pressure differential between output pressures of the modulators during anti-lock control to isolate the higher of said modulator outputs from the respective self-steer axle wheel brakes to thereby provide reduced equal brake pressures to the self-steer wheels corresponding to the modulator pressure at the low adhesion side of the other axle.