Patent ID: 7107683
Filing Date: 2006-09-19
Classification: B29C,B29L,F02D,Y10T

Abstract:
1. A forming method of a throttle apparatus for an internal combustion engine, the throttle apparatus including a substantially tubular throttle body and a substantially disc-shaped throttle valve, the throttle valve having an axis around which the throttle valve rotate in the tubular throttle body between a close position and an open position, the throttle valve and the throttle body being molded substantially simultaneously in same molding dies in such a manner that the throttle valve is rotated by a predetermined angle with respect to a full closed position in which the throttle valve and the throttle body define a minimum gap therebetween, the forming method of the throttle apparatus, comprising: clamping a pair of molding dies to form a body cavity and a valve cavity therein, the body cavity being for molding a throttle body and the valve cavity being for molding a throttle valve in such a manner that the throttle valve is rotated by a predetermined angle with respect to a full closed position, so that the throttle valve is not in contact with an inner bore surface of the throttle body; and substantially simultaneously injecting a melted material into the body cavity and the valve cavity, wherein a rotational shaft rotating with the throttle valve is insert molded in the throttle valve, an insert part rotatably supporting an end of the rotational shaft is insert molded in the throttle body, and a shaft holding portion supporting the rotational shaft is provided in the molding dies, the shaft holding portion being continuously in contact with the outer surface of the rotational shaft between an axial end of the throttle valve and the insert part, said shaft holding portion defining a gap between the axial end of the throttle valve and the throttle body.