| 摘要 |
An exhaust gas recirculation system for an internal combustion engine employs a recirculation control valve in a passageway connecting the engine exhaust passage to the engine intake passage downstream from the throttle valve. An air conduit having an air control valve therein furnishes atmospheric air to the intake passage downstream from the throttle valve. Vacuum responsive actuators are provided for each of the control valves and they are operated by vacuum pressure regulated by a regulating valve, which is itself responsive to differential pressure between vacuum intensity in the intake passage upstream from said throttle valve and modified atmospheric pressure. The modified atmospheric pressure is obtained downstream from a variable throttling valve mounted in a bypass passage connected to the air conduit upstream and downstream with respect to a restriction therein. If atmospheric pressure correction is required, a sealed flexible bellows surrounded by atmospheric pressure may be connected to influence the operation of the variable throttling valve. |
