| 摘要 |
PROBLEM TO BE SOLVED: To provide an exhaust noise control device for an internal combustion engine for controlling the noise of the exhaust gas discharged from an engine by utilizing a route difference of a bypass pipe. SOLUTION: This exhaust noise control device for an internal combustion engine has an exhaust pipe 60 for discharging the exhaust gas of the engine 50 outside, a bypass pipe 70 having a flexible length, divided from the exhaust pipe 60 for separation, formed of U-shape parts and inverted U-shape parts each other, an actuator 80 having an operation rod 80 connected to the bypass pipe 70 to change the length of the bypass pipe 70, and a control unit 90 for controlling the actuator 80. With the structure that the bypass pipe 70 is formed of the U-shape parts and the inverted U-shape parts each other, a location space for the bypass pipe 70 is reduced to the minimum, and while the flexible length of the bypass pipe 70 can be formed long to appropriately reduce the noise in a low-frequency range. A separate means for adjusting the length of the exhaust pipe is provided in the exhaust pipe to widen a length difference between the bypass passage 70, and the noise can be controlled over a wide range. |
