METHOD OF MANUFACTURING THROTTLE BODY

摘要

PROBLEM TO BE SOLVED: To provide a method of manufacturing a throttle body which can prevent defect of the throttle body even when a gate mark projection is broken off. SOLUTION: The throttle body 2 includes a cylindrical bore wall part 3 of which an internal space serves as an air intake passage, and is formed by injection molding. The bore wall part 3 includes a small-diameter part 3a and a large-diameter part 3b continuously formed through a step part 3c as an inclined surface. A base seat 15 is projected from the step part 3c, and then an injection gate 45 is communicated with the base seat 15. The base seat 15 and the injection gate 45 has a bell shape having a corner part. The base seat 15 extends from the small diameter part 3a to the large diameter part 3b, and an inner circumference surface 15b of the base seat 15 is leveled with the small diameter part 3a. A side surface 15a of the base seat 15 is an oblique surface extending from an injection gate 45 side to the bore wall part 3. After molten resin is cured, the gate mark projection 25 is broken off. COPYRIGHT: (C)2011,JPO&INPIT