Vehicle servo assisted clutch - with servo piston coupled to clutch pedal and operating in different modes

摘要

The clutch pedal (12) operates the clutch master cylinder (17) via one lever arm (16b) and is connected to a servo cylinder (20) with a second lever arm (16a). The servo cylinder is pneumatically operated and operates in three distinct phases w.r.t. clutch pedal movement. Initially the servo pressure rises with clutch pedal movement until an operating pressure is reached, which remains constant with increasing clutch pedal movement. The last phase operates on a reducing servo pressure so that the driver does not press the pedal hard against the end stop. The pedal is thus easy to operate and provides some amount of 'feel' over the constant pressure phase, in which only the clutch pedal spring pressure changes.