| 摘要 |
PURPOSE:To perform an EGR control for a vehicle with an automatic speed change gear, by supplying a negative pressure to a negative pressure control valve having priority to a range switch when a large negative pressure is generated for a considerablly long time in a suction pipe. CONSTITUTION:A negative pressure chamber 5a of an EGR valve, connected to an exhaust gas recycling vessel 4, is connected to an EGR port 10 opened to a carburetor ventilation channel 1a near a carburetor throttle valve 9 through an EGR modulator 7 and a BVSV (temperature detection negative pressure valve) 8. The engine is sufficiently warmed up, thereby opening the BVSV 8. When a range switch 18 is open, the negative pressure detected by a sensing port 16, is transmitted to a negative pressure chamber 13a of a negative pressure valve 13 through a VSV (vucuum switching valve) 15 and a first VTV14, thereby closing the valve 13. Under this condition, the negative pressure detected by the EGR port 10 is transmitted to the negative chamber 5a of the EGR valve 5, thereby actuating the EGR valve 5 to have the EGR operation carried out. |
