PURPOSE: To raise intake efficiency and also prevent fluctuation of air quantity in the low rotation region by controlling intake control valves located in plural feed paths communicating to respective cylinders to switch the three, i.e., fully open, semi-open and fully closed positions according to the operation state of an engine.
CONSTITUTION: In a four-cylinder engine in which an intake valve 11 and an exhaust valve 12 are provided in each cylinder, an intake control valve 2 is provided within a manifold 13 upstream of the respective intake valve 11. A pressure regulating valve 14 is provided on the upstream side of the intake control valves 2 to regulate the pressure of intake air each cylinder through the opening degree of the intake control valve 2. The pressure regulating valve 14 and the intake control valve 2 are opened and closed by means of a control circuit 3 incorporating a computer 31. That is, in the case of high engine rotation, at the initiation of the suction stroke, the intake control valve 2 is so controlled as to be from the fully open to the fully closed state in overlap timing between the intake exhaust valves 11, 12, and in the low rotation, light load region, is so controlled to be from the semi-open to the fully closed state.
NOMURA YURIO
NOMURA SHIGEO
HATTORI ISAO
