| 摘要 |
PROBLEM TO BE SOLVED: To enhance a damping effect on noise even if the frequency of the noise varies when a working machine is in operation.SOLUTION: In a working machine 10, a working part 14 of which at least a portion is housed in a housing part 11 is rotated by a power source 15. In the working machine, a silencing chamber 40 is provided. The silencing chamber includes an opening part 41 that opens in the housing part. In the opening part, an opening area adjusting part 50 for adjusting an opening area Ao of the opening part is provided. The opening area adjusting part automatically adjusts the opening area depending on a rotational speed Nr of a power system 51. |
