| 摘要 |
PROBLEM TO BE SOLVED: To dispense with a special space for a catalyst, install an exhaust emission control device in the vicinity of an eninge in an exhaust passage, and improve the exhaust gas purifying efficiency by providing a wall surface catalyst part having a catalyst material on the surface of the inner wall surface in an exhaust passage of an engine. SOLUTION: A exhaust passage 4 of an engine 1 for a vehicle includes in order from the upstream, an exhaust manifold 10, a first exhaust pipe 20, a turbo 5, a second exhaust pipe 40, and a main catalyst 6. The exhaust manifold 10 is so constructed that the inner wall surface 11 is a waveform in a longitudinal section and has a projecting part 11a, a catalyst material 50 is born on the whole surface of the inner wall surface 11, thereby forming a wall surface catalyst part 52 coated with a catalyst layer 51. Thus, a catalyst function is given to the exhaust manifold 10 to purify the exhaust gas passed through the exhaust manifold 10. The catalyst layer 51 is set to have a thickness of 30-100 μm and the catalyst material 50 is formed by dispersing noble metal containing platinum or the like as fine particles in the surface of the alumina or the like. |
