摘要 |
PROBLEM TO BE SOLVED: To shorten a development period by narrowing a clearance between an outer circumference of a throttle valve and an air duct inner circumference of a throttle body as possible and securing a rotating operation of the throttle valve when an air flow control device composed of the throttle boxy and the throttle valve is made of a resin material. SOLUTION: An air flow control device comprises a throttle body 11 made of a composite material, base material of which is a synthetic resin, a throttle valve 12 which has a plate surface 12a and a profile 12b which is formed to fit to an air duct 11a, a throttle shaft 13 supporting the throttle valve, and a bearing 14 supporting the throttle shaft to be rotatable, wherein a molding shrinkage rate,to a spreading direction of the place surface 12a of the composite material which forms the throttle valve is larger than a molding shrinkage to a direction crossing the air duct 11a of the composite material which forms the throttle body 11. |