| 摘要 |
PROBLEM TO BE SOLVED: To provide an idle speed control valve which stably regulates assist air amount flowing through a bypass passage and improves responsibility and reliability. SOLUTION: An idle speed control valve 21 is constituted to include a control valve case 22 formed in a throttle body 4 and a casing 23. A stepping motor 24 for rotating a screw shaft 25 is provided in the casing 23, and the screw shaft 25 is provided with a valve element 26 axially displaced by the rotation. A spring 27 which offsets backlash between the screw shaft 25 and the valve element 26 and acts the valve element 26 to its opening direction is provided between the valve element 26 and the control valve case 22 on the valve seat 22C side. Thus, spring force of the spring 27 helps the stepping motor 24 to open the valve element 26 and facilitates valve opening operation. |
