| 摘要 |
PURPOSE:To reduce the resistance to exhaust-gas flow and to reduce low-frequency noises, by forming a tank at an intermediate portion of an exhaust pipe, and charging a resistor to the sound wave in a branch pipe opened in the exhaust pipe. CONSTITUTION:A silencer 20 has a tank 22 into which exhaust gas is introduced from an exhaust pipe 21 and a branch pipe 24 disposed in the vicinity of the tank 22 to extend from a downstream-side exhaust pipe 23. One end of the branch pipe 24 is opened in the downstream-side exhaust pipe 23 while the other end of the branch pipe 24 is closed. A resistor 25 to the sound wave (for instance, a porous material, many orifices or fiber) is charged uniformly in the branch pipe 24. In the above arrangement, it is preferable that the length of the branch pipe 24 is equal to or longer than 1/4 of the wave length of the exhaust noises to be silenced. |
