Exhaust gas recirculation control device

Claim 1

In an exhaust gas recirculation system having a recirculation conduit to recirculate a portion of exhaust gases from the exhaust system of an internal combustion engine to the intake system thereof having a carburetor, a vacuum actuated exhaust gas flow metering valve normally closing the recirculation conduit; a diaphragm device operatively connected to the metering valve and a vacuum conduit connecting the spring loaded side of said diaphragm device to the intake manifold for actuation of the diaphragm device by the intake manifold vacuum to operate the metering valve, a modulating device comprising a casing interposed in and having a chamber forming part of said vacuum conduit, said chamber having an air bleed port opening tO the atmosphere; an air bleed valve for closing said air bleed port; a spring loaded diaphragm having its spring loaded side connected to the venturi of the carburetor and the opposite side connected to the exhaust system, said spring loaded diaphragm being operatively connected to said air bleed valve such that said air bleed valve is urged toward such air bleed port to decrease air flow through said air bleed port as the magnitude of the venturi vacuum increases.