| 摘要 |
PROBLEM TO BE SOLVED: To provide an exhaust passage structure for an internal combustion engine, capable of early activating an exhaust emission control catalyst while suppressing heat loss due to the contact of exhaust gas with a cylinder head, avoiding the interference with sensors directly attached to the cylinder head, and maintaining the detecting accuracy of the sensors.SOLUTION: The exhaust passage structure for the internal combustion engine has: an exhaust port 42 formed as an exhaust passage 6 in a cylinder head 33; an exhaust pipe 5 connected to the exhaust port; an exhaust emission control catalyst 9 provided in the exhaust pipe; an exhaust gas sensor 8 having a sensor part 8a projecting into the exhaust passage, and mounted to the cylinder head; and a cylindrical inner pipe 7 inserted at its upstream end 7a into the exhaust port and at its downstream end 7b into the exhaust pipe to construct the exhaust passage. The upstream end of the inner pipe is located in the exhaust passage upstream of the sensor part. In the inner pipe, sensor avoiding parts 70A, 70B, 70C are formed to avoid the sensor part. The sensor part is arranged projecting from the sensor avoiding parts of the inner pipe in the inward direction of the inner pipe.SELECTED DRAWING: Figure 2 |
