| 摘要 |
PURPOSE:To aim at reducing exhaust noise, by providing a horizontal partition plate having a short downstream end in the direction of an exhaust stream, in a port insert which is fitted in an exhaust passage section communicated with an exhaust port and formed in a rotor casing. CONSTITUTION:A through-hole 9 which is composed of a seat hole section 9a extending inward from the outer surface 1b of a rotor housing, an inclined hole section 9b and a parallel hole section 9b nearest to an inner peripheral surface 4, is formed in an exhaust port 7 wich is formed in the rotor housing 1, and is fitted therein with a port insert 8 which is provided therein with a horizontal partition plate 16 which divides leading and trailing side exhaust passages 20, 21. In this arrangement, the downstream side section of the horizontal plate 16 is shorter than the exhaust passage section of the rotor housing 1. With this arrangement, the area of the partition plate 16 which are made into contact with exhaust gas may be made as small as possible to reduce exhaust noise. |
