| 摘要 |
PURPOSE:To improve the charging efficiency by setting the valve opening timing of a supercharger side suction valve close to the position where the rate of increase of the cylinder capacity in suction cycle becomes max., in an engine which is equipped with an intake passage equipped with a supercharger and a natural air intake passage and inhales each gas from each suction valve. CONSTITUTION:Each cylinder 8 is equipped with a port 2a into which the pressurized air is supplied from a supercharger 9 and a port 1a for natural-air feed, and suction valves 12 and 7 are installed onto the ports 2a and 1a, respectively. The valve opening timing for the supercharger side suction valve 12 is set at a crank angle of 45 deg. where the rate of increase of the cylinder capacity becomes max. in the suction cycle in which a piston lowers or a little before said crank angle. Therefore, the supercharged air is inhaled at the time when the flow passage of the natural inhaled air is sufficiently high, and the blowing- off into a natural inhaled air passage is prevented, and charging efficiency can be improved. |
