Engine exhaust gas recirculation control mechanism

摘要

A turbocharged or supercharged engine is provided with a vacuum actuated control device for an exhaust gas recirculation valve. A venturi throat in the engine air intake passage generates a vacuum in response to air flow through the throat. The vacuum is varied according to variations in the air flow rate throughout the throat, such that the vacuum can be applied to a piston for adjusting the position of a metering valve in an exhaust gas recirculation passage. The vacuum controlled valve enables the gas recirculation rate to be varied as a function of the air flow rate through the engine air intake passage.