Exhaust gas recirculation system with an auxiliary valve
AssigneeToyota Jidosha Kogyo Kabushiki Kaisha
InventorMasaaki Tanaka
Life of this patent
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Abstract
In an internal combustion engine which incorporates an exhaust gas recirculation system which has an exhaust gas recirculation flow control valve provided at a middle position of the exhaust gas recirculation passage, the control valve being operated depending upon comparison between target and actual values of a control parameter with regard to the amount of exhaust gas recirculation, an auxiliary valve is provided in the exhaust gas recirculation passage in series with the exhaust gas recirculation flow control valve so as to control the cross-sectional area of the exhaust gas recirculation passage in accordance with the opening amount of the throttle valve provided in the intake passage of the engine.
Claims5
An exhaust gas recirculation control system for an engine which has an intake passage which incorporates a throttle valve, and an exhaust passage, comprising:
- an exhaust gas recirculation passage which joins between said exhaust passage and said intake passage;
- means to detect engine operating parameters;
- an exhaust gas recirculation flow control valve, provided at a middle portion of said exhaust gas recirculating passage, so as to control the cross-sectional area of said exhaust gas recirculation passage according to a control signal;
- a computing controller comprising a memory means which is adapted to store target values of a control parameter corresponding to opening amounts of said exhaust gas recirculation flow control valve which provide the most desirable amounts of exhaust gas recirculation under various engine operating conditions determined by combinations of said engine operating parameters, wherein said computing contoller computes the target value of said control parameter based upon said engine operating parameters and compares said target value with the actual value of said control parameter and based thereupon produces said control signal;
- and
- an auxiliary valve located in said exhaust gas recirculation passage which is linked with said throttle valve and controls the cross-sectional area of said exhaust gas recirculation passage in relation to the opening amount of said throttle valve.
Dependencies are inferred from the claim text.