| 摘要 |
PURPOSE:To provide smooth and positive operation and simplify constitution by providing a bypass parallel to a throttle valve in an intake path of an engine and arranging respective temperature responsive and pressure responsive type controlling valves parallel to the bypass to control intake air amount. CONSTITUTION:An intake path 1 is formed with a bypass 3 communicating to the upstream and downstream sides of a throttle valve 2. In this bypass 3 are provided in parallel a temperature responsive type controlling valve 4 closed by temperature rise of an engine and a pressure responsive type controlling valve 5 opened by relatively small negative intake pressure in the starting operation of the engine and closed by relatively large negative intake pressure in the complete combustion of the engine. Then, the controlling valve 4 is provided at the rear side of a valve body 4b opposed to a valve seat 4a with an operating rod 4d and a temperature responsive member 4e through a spring 4c. Also, the controlling valve 5 is provided between front and rear valve seats 5a, 5b with a valve body 5d urged rearward by a spring 5c and forward by the negative intake pressure. |
