| 摘要 |
PURPOSE: To prevent a throttle valve from being fixed by opening an auxiliary air path outlet in a main air intake path bore for auxiliary air flow flowing from the outlet to the main air intake path in the direction of swirl flow. CONSTITUTION: Deposit components which are led into an air intake path by an exhaust gas recirculation system and a crankcase emission control system float in a boundary part between the outer peripheral edge of a throttle valve 2 and the inner wall surface of a main air intake path 4. The deposit components become easier to adhere according to the pressure conditions in the main air intake path 4. Also an auxiliary air path outlet 21 of an auxiliary air path 5 is opened in the downstream of the throttle valve 2 inside the main air intake path 4 at one part which remotes mostly from a valve shaft 3 of the fully closed throttle valve 2 in the tangential direction of an air intake path bore. Thus air flow flowing from the auxiliary air path outlet 21 to the main air intake path 4 is swirled in the arrow direction along the boundary part so as to increase a ratio at which the deposit components are blow out. |
