| 摘要 |
PROBLEM TO BE SOLVED: To provide a helmholtz resonator type muffler capable of further improving muffling effect without offsetting resonance vibration frequency from frequency of muffling target sound.SOLUTION: The helmholtz resonator type muffler comprises a cavity part and a communication hole 18a communicating the cavity part to the outside. The communication hole 18a has a notch part 18c on an inner peripheral surface 18b of a shell 18 so as to enhance viscosity resistance generated between air in the communication hole 18a which is vibrating and a surface of the communication hole 18a. |
