| 摘要 |
PURPOSE:To improve the drivability of a vehicle, by providing a check valve for keeping negative pressure for operating a vacuum motor, and a thermosensitive valve for eliminating the negative pressure, to enhance the performance of an engine. CONSTITUTION:A warm air intake passage 22 and a cold air intake passage 23 are connected to each other upstream to a carburetor 18 in the intake passage 15 of an engine. A changeover valve 24 is provided between the connected portions of the passages 22, 23. A check valve 40 for keeping negative pressure for operating a vacuum motor 28 is provided for a negative pressure pipe 30 which connects a vacuum motor operating negative pressure takeout portion and a thermal valve 31 to each other. A thermosensitive valve 41, which removes the vacuum motor operating negative pressure when the temperature of external air is higher than a set level, is provided in parallel with the check valve 40. As a result, the performance of the engine is enhanced to improve the drivability of a vehicle. |
