Intake manifold for use in air intake system of four-cylinder engine, has valve housing, lower port and upper port connected with each other in single piece so that housing lies between ports

摘要

The manifold (10) has a switching valve (41) arranged in a switching valve housing (40). The valve housing, a lower port (20) and an upper port (30) are connected with each other in a single piece so that the housing lies between the ports. An intake passage is formed in the upper port and the housing. Another intake passage is formed in the lower port and a part of the upper port and the housing. The switching valve is arranged in the former passage to change flow passage of air between the passages according to an operating condition of a four-cylinder engine.