| 摘要 |
PROBLEM TO BE SOLVED: To prevent condensation of steam in exhaust gas which is caused by excessively cooling exhaust gas flowing in an exhaust passage, to prevent an oxygen sensor installed in the exhaust passage from getting wet, and to improve the durability thereof.SOLUTION: A combustion chamber surrounding water jacket 65 and an exhaust port surrounding water jacket 66 are respectively formed in a cylinder head 31 of an engine, and a cylinder surrounding water jacket 67 and an exhaust passage surrounding water jacket 68 are respectively formed in a cylinder block 30 of the engine. The water jackets are connected so that cooling water taken from a water inlet 61 and introduced into a water supply passage 62 flows through the combustion chamber surrounding water jacket 65, the exhaust port surrounding water jacket 66, the cylinder surrounding water jacket 67 and the exhaust passage surrounding water jacket 68 in this order.SELECTED DRAWING: Figure 4 |
