Forming method of throttle apparatus for internal combustion engine

摘要

A throttle valve and the throttle body are formed substantially simultaneously in the same dies. The melted resin is injected in to a cavity through a pair of valve gates. The valve gates are symmetrically located with respect to the throttle valve shaft. A deformation of the throttle valve can be avoided because a stress concentration on the metal shaft of the throttle valve is reduced in opening the dies.