Exhaust gas recirculation system
AssigneeNissan Motor Co., Ltd.
InventorTetsuya Harada
Life of this patent
Estimating the term…
Abstract
An additional vacuum servo is provided to be associated with a vacuum servo of an air supply control valve controlling the amount of atmospheric air fed into a vacuum actuator of an EGR control valve and is operable, in response to the vacuum in the vacuum actuator reduced by the fed atmospheric air, to minutely adjust the degree of opening of the air supply control valve to minutely adjust the amount of the atmospheric air fed into the vacuum actuator.
Claims10
An exhaust gas recirculation system for an internal combustion engine, comprising an exhaust gas recirculation (EGR) passageway for feeding exhaust gases of said engine into an intake passageway of said engine, an exhaust gas recirculation (EGR) control valve disposed in said EGR passageway, a vacuum actuator operatively connected to said EGR control valve and having a first vacuum chamber subjected to the vacuum in said intake passageway adjacent to a throttle valve rotatably mounted therein, said EGR control valve being operable in response to the vacuum in said first vacuum chamber to control the amount of the engine exhaust gases fed into said intake passageway, passage means communicating with the atmosphere and with said first vacuum chamber to feed atmospheric air thereinto to reduce the vacuum in said first vacuum chamber, an air supply control valve associated with said passage means, a vacuum servo operatively connected to said air supply control valve and having a second vacuum chamber subjected to an intake passageway vacuum in said intake passageway downstream of said throttle valve, said air supply control valve being operable in response to the vacuum in said second vauum chamber to control the amount of atmospheric air fed into said first vacuum chamber, and operating means operatively connected to said air supply control valve and operable in response to the vacuum in said first vacuum chamber reduced by said atmospheric air fed to minutely adjust the degree of opening of said air supply control valve to minutely adjust the amount of atmospheric air fed into said first vacuum chamber to thereby make it possible for said EGR control valve to meter the amount of said engine exhaust gases fed into said intake passageway to a predetermined ratio to the amount of air drawn into said engine.
A combination of an internal combustion engine and an exhaust gas recirculation (EGR) system, said engine including an intake passageway having a throttle valve rotatably mounted therein and an exhaust gas passageway, said EGR system comprising an exhaust gas recirculation (EGR) passageway interconnecting said exhaust gas passageway and said intake passageway to feed exhaust gases of said engine thereinto, an exhaust gas recirculation (EGR) control valve disposed in said EGR passageway, a vacuum actuator operatively connected to said EGR control valve and having a first vacuum chamber, first passage means interconnecting said first vacuum chamber and said intake passageway adjacent to said throttle valve, said EGR control valve being operable in response to the vacuum in said first vacuum chamber to control the amount of the engine exhaust gases fed into said intake passageway, second passage means communicating with the atmosphere and with said first passage means to feed atmospheric air thereinto to reduce the vacuum in said first vacuum chamber, an air supply control valve associated with said second passage means, a vacuum servo operatively connected to said air supply control valve and having a second vacuum chamber communicating with said intake passageway downstream of said throttle valve, said air supply control valve being operable in response to the vacuum in said second vacuum chamber to control the amount of atmospheric air fed into said first passage means, and operating means operatively connected to said air supply control valve and operable in response to the vacuum in said first passage means reduced by said atmospheric air fed to minutely adjust the degree of opening of said air supply control valve to minutely adjust the amount of atmospheric air fed into said first vacuum chamber to thereby make it possible for said EGR control valve to meter the amount of said engine exhaust gases fed into said intake passagey to a predetermined ratio to the amount of air drawn into said engine.
Dependencies are inferred from the claim text.