| 摘要 |
PURPOSE:To make an effective cross section for an exhaust passage expandable as well as to aim at improvement in a rate of fuel consumption in lowering temperature and exhaust pressure of exhaust gas, by installing an interconnecting passage, interconnecting an interval between respective independent exhaust passages, at the more upstream side than a centralized part of these plural independent exhaust passages. CONSTITUTION:Each one end of an exhaust passage 24 is interconnected to each exhaust port 16 of each of cylinders #1-#4 separately, and it is provided with plural independent exhaust passages 26a-26b, where each other end is centralized so as to be mutually converged. In this case, these independent exhaust passages 26a-26d are interconnected with one another by an interconnecting passage 28 at the more upstream side of the converging part, namely at a position near to the exhaust port 16. And, at the time of, for example, high speed, high load driving of an engine, each of interconnecting control vales 30 installed in the converging part with these independent exhaust passages 26a-26d in the interconnecting passage 28 is opened. With this constiution, an effective cross section of the exhaust passage 24 is expanded wide, and passage resistance, exhaust pressure and temperature of exhaust gas are all lowered. Accordingly, a rate of fuel consumption at the time of high speed, high load is abatable.
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