CONTROL VALVE ACTUATOR

摘要

A vacuum booster (12) having a control valve (66) independently actuatable by a manual input applied to an operator pedal assembly (16) to effect a brake application or by a traction control force derived from a signal developed by a controller (35) to selectively apply brake force to synchronize rotational spin of the wheels of a vehicle. An input rod (76) connected to the control valve (66) has a housing (75) attached thereto with a traction control chamber (117) therein. A sleeve (78) which surrounds the input rod (76) has a first flange (110) that engages a shoulder (102) on the input rod (76) and a second flange (98) that is connected to a diaphragm (92) retained in the traction control chamber (117). A return spring (116) acts on the first flange (110) to urge the second flange (98) and diaphragm (92) against a stop (84) in the housing (75). In response to an input signal the controller (35) allows vacuum to be communicated to the traction control chamber (117) to create a traction control pressure differential. The traction control pressure differential acts on the diaphragm (92) to develop a force which is applied to the second flange (98) to compress the return spring (116) and permit a pressure differential to move the control valve (66) and permit environmental air to create an operational pressure differential to develop a traction control output force. The traction control output force pressurizes fluid in the master cylinder (14) which is selectively applied to the wheel brakes to synchronize the rotational spin of the wheels.