Patent ID: 6026791
Filing Date: 2000-02-22
Classification: F02B,F02M,Y02T

Abstract:
A control valve for an EGR system for an internal combustion engine comprising:an EGR valve having a variable pressure actuator for operating a valve poppet to meter EGR flow from an exhaust flow line to an EGR flow line, the pressure actuator having a pressure port, the pressure actuator responsive to pressure in the pressure port;a differential pressure controller havinga first pressure port connected to the exhaust flow line and a second pressure port connected to the EGR flow line,a proportional electrical solenoid connected to a piston in a cylinder forming a first chamber on a first side of the piston communicating with the first pressure port and a second chamber on a second side of the piston communicating with the second pressure port,a shaft connected to the piston and containing an orifice, the shaft movable with the piston to position an inlet of the orifice adjacent a pressure source in a first position of the piston induced by lower pressure in the first pressure port than the second pressure port and the inlet of said orifice positioned adjacent a pressure vent in a second position of the piston induced by higher pressure in the first pressure port than the second pressure port, an outlet of said orifice connected to the variable pressure actuator pressure port;means connected to the shaft for balancing the electrical solenoid and piston; andmeans for providing a control signal to the proportional electrical solenoid.