| 摘要 |
PROBLEM TO BE SOLVED: To provide an intake air flow control device including a flow regulating valve provided with a valve shaft disposed transversely across an intake duct of a throttle body and a plate-like valve body coupled to the valve shaft so as to rotate integrally with the valve shaft, enabling an intake duct peripheral wall to act as stopper means for defining a minimum valve opening degree of the flow regulating valve to suppress the abrasion of the peripheral wall while achieving a simplified structure and the reduced resistance of intake air during valve opening.SOLUTION: For a flow regulating valve V2, only a circular-arc outer peripheral edge portion 20c, on one side relative to a valve shaft j2, of a valve body b2 is brought into contact with a peripheral wall of an intake duct 2 when the flow regulating valve V2 rotates up to a predetermined position, thereby defining a minimum valve opening degree, the circular-arc outer peripheral edge portion 20c contacts the peripheral wall in a predetermined region continuous with the valve body b2 in the circumferential direction of the valve body b2 by at least riding over a virtual plane f' orthogonal to the valve shaft j2 and passing through a center line of the intake duct 2, and a contact surface, which contacts with the peripheral wall, of the circular-arc outer peripheral edge portion 20c is formed into a round surface r having a circular arc cross-section.SELECTED DRAWING: Figure 3 |
