| 摘要 |
PURPOSE:To recirculate an optimum volume of exhaust gas according to an operating condition by controlling a negative pressure value transmitted to a negative pressure chamber of EGR control valve by a throttle valve opening and an exhaust gas concentration for an exhaust gas recirculation system. CONSTITUTION:Intake/exhaust pipes 2 and 3 of internal combustion engine 1 are communicated with exhaust gas reflux tubes 6 and 13 having an EGR valve 5. One side of a negative pressure tube 20 of a negative pressure chamber 17 of EGR valve 5 is communicating with the intake pipe locating at upper stream of a throttle valve 4, other side thereof being communicating with an intake pipe 2 locating at downsteam of throttle valve 4 through a regulator 9. A regulator 9 is provided with a diaphragm 10 for varying the force of spring 14 of magnet valte 100 which regulates change-over valve 23 and change-over valve 23. Then, the magnet valve 100 is regulated by a computer 103 which receives an opening signal of throttle valve 4 and a signal of concentration sensor 106, and the exhaust gas pressure of reflux tube 6 is acturaing on the bottom chamber 11 of diaphragm 10. |
