HYDRAULIC APPARATUS, SYSTEM AND METHOD FOR POSITIONING AN ENGINE EXHAUST FLOW CONTROL VALVE

摘要

A hydraulic assembly and method for use with an vehicle engine exhaust flow control valve for controlling flow to at least one intake supply. The assembly has an actuator, such as a spring return piston cylinder (12), for positioning the control valve. An inlet passage (9), communicating with the cylinder, is arranged for supplying hydraulic fluid to a side of the actuator and a drain is arranged for draining the hydraulic fluid from the side of the actuator. An on-off type hydraulic valve (17), communicating with the drain, is operably coupled to the cylinder for controlling communication of the hydraulic fluid from the cylinder side to the drain. When the hydraulic assembly is in use, the pressure of hydraulic fluid acting on the actuator is adjustable by operation of the on-off type valve thereby to control movement of the actuator and, in turn, movement of the control valve.