THROTTLE BODY AND METHOD OF MANUFACTURING SAME

摘要

A stepped section (11) composed of convex-shaped steps (11a) is formed on an outer peripheral wall of a throttle body (10) which surrounds a throttle valve. The throttle body (10) is formed from a resin material, in which glass fibers or carbon fibers are mixed for increased strength. A concave-shaped portion is formed at a position where a molding die corresponds to the steps (11a), and when passing through the concave-shaped portion, a flow of the resin material is disturbed, so that the fiber material mixed is randomly disturbed in orientation. Random disturbance in orientation of the fiber material is generated unitarily on a circumference of the throttle body (10), on which the stepped section (11) is formed. Accordingly, the throttle body (10) exhibits isotropy when experiencing thermal expansion or shrinkage, so that it is possible to prevent variations in clearance defined between an outer peripheral edge of the throttle valve and an inner wall of the throttle body (10).