Air intake device for engine

Abstract

An air intake device for an engine is provided that includes a bypass () connected to an air intake path () while bypassing a throttle valve (), and a bypass valve (V) for controlling the degree of opening of the bypass (), the bypass valve (V) being formed from a tubular valve chamber () having its interior opening on the upstream side of the bypass () and having an inner face with a metering hole () opening toward the downstream side of the bypass (), and a valve body () slidably but non-rotatably fitted into the valve chamber () and opening and closing the metering hole (), wherein an inner face (A) of the valve chamber () on which the metering hole () opens and an outer face (B) of the valve body () opposing the inner face (A) and covering the metering hole () are formed in the same shape so as to enable them to be in intimate contact with each other, and other inner (A) and outer faces (B) of the valve chamber () and the valve body () are formed so that there is a gap (g) therebetween. This enables the valve body to be reliably in intimate contact with the inner side face of the valve chamber on which the metering hole opens while guaranteeing smooth sliding of the valve body in the valve chamber in the bypass, thus preventing leaked air from flowing into the metering hole.