| 摘要 |
A control valve for an EGR system employs a variable pressure actuator connected to a valve for metering EGR flow and a differential pressure valve connected to supply actuation pressure to the actuator. The differential pressure valve incorporates a proportional solenoid connected to a pressure balancing piston which receives EGR pressure on one side and exhaust flow pressure on the other. The piston is connected to a shaft having an orifice positionable adjacent a pressure source in a first position and a pressure vent in a second position, an outlet of the orifice communicating with the pressure actuator. EGR control is accomplished by providing a signal to the proportional solenoid which shifts the pressure balance point for the piston. |
