| 摘要 |
PURPOSE:To mitigage a shock when a switching valve is opened/closed by dividing multiple cylinders into multiple cylinder groups and staggering the set areas of the switching valve opened at a high load for each cylinder group. CONSTITUTION:Two intake valves 1A, 1B are provided for each cylinder 4, and a switching valve 3 is provided on an intake port 2A of one of them. Two cylinders out of four cylinders are formed in one group respectively, and the switching valve 3 of the two cylinders is driven to be opened/closed by one shaft 21A, 21B respectively. In a control circuit 28, a selector valve 24 is switched to the negative-pressure tank 27 side at a predetermined high load, immediately a negative-pressure actuator 23A is activated and the switching valve 3 is opened, the high load is transmitted to the actuator 23B side via a negative-voltage delay throttle 25, thus the actuator 23B is actuated after a predetermined time, and the switching valve 3 of the other cylinder group is opened. |
