INTAKE DEVICE FOR ENGINE

PURPOSE:To perform resonance supercharge under wide rotary range of engine by setting such that one of two paths communicating between surge tanks will achieve gas resonance under low and high rotary regions while the other will achieve under intermediate rotary region. CONSTITUTION:Under operation of engine, the outputs from a rotation sensor 14 and a negative pressure sensor 15 are provided to a control circuit 16 which will provide a signal to an actuator 13 thus to open/close a changeover valve 12. Here, said valve 12 is closed under heavy load low rotation region to produce the primary resonance of intake air in a surge tank 1 with primary inherent frequency to be determined by the shape of first communication path 9 thus to perform resonance supercharge to each cylinder with high efficiency. Under heavy load intermediate rotary region, said valve 12 is opened to produce primary resonance of the intake air with primary inherent frequency to be determined by the shape of second communication path 10. While under low load region, said valve 12 is closed continuously to feed the intake air between both chambers 3, 4 of surge tank 1 thus to feed approximately same amount of intake air to each cylinder.