| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To control actuators 16 and 18 to open and close an exhaust cut valve 15 and an exhaust bypass valve 17 so that both a main exhaust passage 9 and an exhaust bypass passage 10 are prevented from fully closed. <P>SOLUTION: Constitution is made such that the exhaust cut valve 15 is opened when a negative pressure working chamber 38 of an actuator 18 for operating the exhaust cut valve is at an atmospheric pressure and when at a negative pressure, the exhaust cut valve 15 is closed. Constitution is made such that when a negative pressure working chamber 33 of an actuator 18 for operating an exhaust bypass valve is at an atmospheric pressure, an exhaust bypass valve 17 is closed and when at a negative pressure, the exhaust bypass valve 17 is opened. Negative pressure routes 23-25 are provided such that by an electromagnetic three way solenoid valve 19, a negative pressure or an atmospheric pressure is fed in series in the order of the actuator 18 for operating the exhaust bypass valve and the actuator 16 for operating the exhaust cut valve through the negative pressure routes. <P>COPYRIGHT: (C)2004,JPO&NCIPI</p> |
