| 摘要 |
PURPOSE:To prevent the back flow of the intake air at the time of the actuation start of a secondary side supercharger by constituting the captioned structure so that the intake air is sucked from a secondary side intake passage utilizing the intake air flow in a primary side intake passage in the structure in which superchargers are arranged respectively in the primary and secondary side intake passages arranged in a row. CONSTITUTION:The intake passage 3 of an engine 1 is branched to branch intake passages 3a and 3b at the downstream side of an air flow meter 4, and their downstream sides are joined at the upstream side of an intercooler 5. Blowers Cp and Cs of primary and secondary side turbosuperchargers 9 and 10 are correspondingly arranged to passages 3a and 3b, and the passages 3a and 3b at the downstream side of the blowers Cp and Cs are connected to a common intake passage 3 of the downstream at a confluence part X. At this time, the upstream side from the part X is set so as to be in the same direction as the intake air flow direction to the utmost in the downstream from the part X, and when the intake cut valve 21 provided in the secondary side passage 3b is opened, the intake air within the passage 3b is made to be suctioned by the fast intake air flow from the passage 3a. |
