| 摘要 |
PROBLEM TO BE SOLVED: To provide a strong gas flow while assuring a large residual intake air path area without being restricted by an intake flow control valve 4. SOLUTION: A butterfly valve type intake flow control valve 4 having a tabular valve element 6 installed on a rotating shaft 5 connected to an actuator is provided in an intake air path 3 in the upstream of an intake air port 2. An opening part 7 is formed by cutting at one end edge of the valve element through the center of the rotating shaft 5 and in a full close position, the other end edge 6a is formed so that a clearance Δ of approx. 0.3 to 0.5 mm remains from the inner wall surface of the intake air path 3. In the operating conditions to intensify a turbulence, the valve element 6 is used in the state of being opened by a specified angle θ of approx. 10 to 25 deg. from the full close position. Because a jet flow G2 branched from the end edge 6a presses an intake main flow G1 from the opening part 7 against the wall surface a gas flow in a cylinder is further intensified. |
