| 摘要 |
PURPOSE:To enable the airtight state in full closing to be kept even if the dimensional precision of a throttle valve body is made rough. CONSTITUTION:Hemispherical projecting lines 7a, 7b are so provided as to extending from upper and lower intake passage walls of a valve shaft 2 to the intake passage center direction. Rubber seal members 8, 8 are fixed in the position to face the projecting streaks 7b, 7b of a plate valve 1. Projecting streaks are provided on the rubber seal members 8 and so arranged as to be brought in light-contact with the projecting streaks of the intake passage in a state where the projecting streak is inclined in the full closed position of the plate valve 1. These projecting streaks receive moment by pressure difference between the upstream and the downstream of the intake passage and is brought in pressure-contact with the projecting streak 7b, 7b of the intake passage, thereby airtightness of the plate valve 1 is secured. |
