To excellently send exhaust gas in an engine exhaust passage into a crankcase, while restraining deterioration in engine oil.
An auxiliary catalyst 13 and a main catalyst 15 are arranged in the engine exhaust passage. The inside of an exhaust pipe 14 on the upstream side of the main catalyst 15 which is the downstream side of the auxiliary catalyst 13 is successively connected to the inside of the crankcase 20 via an upstream side communicating passage 17u, an introduction control valve 18 and a common communicating passage 19. The inside of an exhaust pipe 16 on the downstream side of the main catalyst 15 is successively connected to the inside of the crankcase 20 via a downstream side communicating passage 17d, the introduction control valve 18 and the common communicating passage 19. A rate of an exhaust gas quantity introduced via the upstream side communicating passage 17u and an exhaust gas quantity introduced via the downstream side communicating passage 17d is changed according to an engine operation state by controlling the introduction control valve 18. Blow-by gas in the crankcase 20 is substituted by the introduced exhaust gas.
| JPH0583313U | 1993-11-12 | |||
| JP2005248927A | 2005-09-15 | |||
| JPH0979022A | 1997-03-25 | |||
| JPH08504912A | 1996-05-28 |
Jun Tsuruta
Tetsuro Shimada
Shinji Mitsuhashi
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