PASSAGE CONTROL DEVICE FOR HELICAL TYPE SUCTION PORT

摘要

PURPOSE:To ensure the high charging efficiency during a high speed operation by providing a closing valve which is opened when the intake air volume exceeds a predetermined value at a branch path provided on a helical type suction port of an engine provided with a helical type suction port and the second suction port. CONSTITUTION:During a low speed and low load operation of an engine, solenoids 40, 48 ae de-energized and a negative pressure is applied in negative pressure chambers 35, 44, a rotary valve 18 and a suction cutoff valve 28 are closed, and the intake air is fed through a helical type suction port 6a to generate a strong eddy current in a combustion chamber 4. Next, as the engine is operated at a medium speed and a medium load, the solenoid 48 is energized, thus connecting the negative pressure chamber 44 to the atmosphere and fully opening the suction cutoff valve 28, then air is fed through the second suction port 6b too, and the eddy current from the port 6a is weakened. Next, as the engine is operated at a high speed and a high load, the solenoid 40 is energized, thus connecting the negative pressure chamber 35 to the atmosphere and fully opening the rotary valve 18, then a large amount of air is fed into a volute section through a branch path 14, thereby the high charging efficiency can be ensured.