| 摘要 |
<p>PURPOSE:To keep off a cylinder noise in neutral without entailing any drop in engine output in time of engine driving, by coupling each of suction air passages with a coupling passage, while closing the coupling passage in the neutral by means of a shift operating mechanism. CONSTITUTION:When a shift operating mechanism 32 is in a neutral N position, a neutral lamp 36 is lighted for indication. Therefore, at an electric circuit 34 being coupled with the neutral lamp 36, an electric current flows, turning a solenoid valve 30 to ON. Accordingly, a valve body 28 of a neutral valve 30 is promected outward, closing a coupling passage, whereby both first and second suction air passages 12 and 16 are intercepted, checking the propagation of a pressure wave acting on each cylinder, thus the generation of a cylinder noise is preventable from occurring. On the other hand, when the shift operating mechanism 32 is in a position other than the neutral or in time of engine driving, the neutral lamp 36 is no longer lighted and indicated and thereby the valve body 28 opens the coupling passage 24. With this constitution, the cylinder noise can be kept back from occurring owing to a dynamic effect of the coupling passage 24.</p> |
