| 摘要 |
PURPOSE:To obtain sufficient engine output during high speed and heavy load operation of engine by opening an opening/closing valve when the air intake quantity, engine load and engine speed are larger than predetermined values. CONSTITUTION:When the temperature of engine cooling water is high and the air intake quantity is small, and also an engine is in low speed and light load operation after completion of warming up, since a solenoid 48 is deenergized, a valve 46 closes an atmospheric air port 41. When the negative pressure in a surge tank 26 grows high, said negative pressure through a check valve 45 moves a diaphragm 33 toward the negative pressure chamber 36 side and an entrance part of a bypass passage is closed. When the temperature of the engine cooling water is high and the air intake quantity is large, and also the engine is in high speed and heavy load operation after completion of warming up, the solenoid 48 is energized and the valve 46 opens the atmospheric air port 41, therefore, the negative pressure chamber 36 comes to have the atmospheric air pressure, a rotary valve 19 opening the bypass passage. In case the temperature of engine cooling water is low, the solenoid 48 is energized before completion of warming up. |
