| 摘要 |
PURPOSE:To improve the durability of a switching means by constructing a change valve provided in an exhaust passage at the down stream of a supercharger turbine when the number of exhaust gas turbo type superchargers which should operate in response to the speed of revolution of an engine is changeably controlled by the switching means. CONSTITUTION:The respective exhaust port 3 of two groups of cylinders consisting of three cylinders respectively the firing order of which is discontinuous is connected to the first and collecting portion X1, X2 formed by a partition wall 32e in an in-line 6 cylinder engine. Respective collecting portion X1, X2 is connected to the exhaust gas introducing ports of the first and the second supercharger 22, 23 via branching exhaust passages 33, 34. In this case, a change valve 35 is provided at a branching exhaust passage 37 where exhaust gas passes through after it passes through a turbine 23b. Meantime, the change valve 35 is opening/closing-controlled to operate only a supercharger 22 at the time of a low speed, and to operate both supercharger 22, 23 at the time of a high speed. Accordingly, a chance to contact with dirty exhaust gas in a high temperature and a high pressure is reduced to improve its durability. |
