FEEDBACK-CONTROLLED POWER-ASSISTED BRAKING SYSTEM

摘要

A motor vehicle power-assisted braking system including a master cylinder (200) for generating an increase in brake fluid pressure in at least one wheel brake (300), and a pneumatic brake servo (100) controllable by applying an input force (F2) to a control rod (26) to actuate the master cylinder. The main hydraulic piston (30) of the master cylinder (200) itself comprises a hollow movable cylinder (32) within which is sealingly and axially slidable a feedback piston (34) to which at least said input force (F2) may be applied. Resilient means (46) exert a resilient force between the feedback piston (34) and the movable cylinder (32) and bias the feedback piston (34) towards the master cylinder (200). Said feedback piston (34) defines, inside said movable cylinder (32), a feedback chamber (36) which is isolated from the inner space (V) of the master cylinder (200), and in which the prevailing hydraulic pressure is that provided by at least one sensor (G, G') sensitive to the changes in at least one physical quantity in response to the changes in the input force (F2).