| 摘要 |
PURPOSE:To reduce the exhaust quantity of nitrogen oxides without deteriorating the operation performance of an engine, by providing a control circuit which calculates desired values on the basis of the signals of an engine sensor and an opening degree sensor to regulate solenoid valves for controlling the negative pressure of an intake pipe and the atmospheric pressure. CONSTITUTION:An exhaust gas recycling equipment for returning some of exhaust gas from an exhaust pipe 5 to the intake line of an engine 1 comprises recycling pipes 6, 7 and an exhaust control valve 10 installed between the pipes. The exhaust control valve 10 is a diaphragm unit having a pressure chamber 14 to which control pressure is conducted. The negative pressure in an intake pipe downstream to a throttle valve 3 is modified by a pressure compensator 30 to obtain the control pressure. The compensator 30 comprises a first solenoid valve 21 in a negative pressure pipe 31 and a second slenoid valve 22 in an atmospheric pressure pipe 33. These solenoid valves 21, 22 are appropriately regulated by a control circuit 28 on the basis of the outputs of an intake pipe negative pressure sensor 24 and an electromagnetic pickup 27 which detects the rotational frequency. |
