| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an intake and exhaust device of a multi-cylinder engine capable of increasing an engine output by further increasing an intake amount with a simple structure. <P>SOLUTION: An independent exhaust passage 52 connected to an exhaust port 18 of a plurality of cylinders 12 and a manifold part 56a connected to each independent exhaust passage 52 have a shape such that a negative pressure is generated in the exhaust port 18 connected to another adjacent independent exhaust passage 52 by ejector effect as exhaust from each cylinder 12 is discharged to the manifold part 56a. An overlap duration of one cylinder 12 having a contiguous exhaust order and a valve-opening start timing of an exhaust valve 20 of the other cylinder 12 are overlapped with each other. The valve-opening start timing of the exhaust valve 20 is advanced with the increase in engine rotation speed so that the timing when the negative pressure generated in the exhaust port 18 of the one cylinder 12 by the exhaust discharged from the other cylinder 12 becomes maximum overlaps with the overlap duration of the one cylinder 12. <P>COPYRIGHT: (C)2012,JPO&INPIT |
