| 摘要 |
PROBLEM TO BE SOLVED: To improve air permeability of a ventilation path in a noise reduction device for the ventilation path, which suppresses propagation of noise from a noise source disposed within the ventilation path.SOLUTION: A plurality of tubular ducts 4 which are opened between a noise source 2 located at one side of a ventilation path configuration 1 for guiding gas and a release part 3 for gas located at the other side are disposed side by side in a planar shape while aligning the aperture sides thereof, and each of the ducts 4 includes an expansion chamber 5, the duct diameter of which is expanded partially, such that an expansion type muffler is obtained. Therefore, while keeping a ventilation path, propagation of noise generated in the noise source 2 to the release part 3 is suppressed. An outer shape of a portion of the expansion chamber 5 is made polygonal other than a circular shape and formed in such a manner that, when the plurality of ducts 4 are disposed side by side in the planar shape, outer surfaces of the expansion chambers 5 are brought into tight contact with each other. Any gap is not formed between the neighboring ducts 4 and together with the outer shape of the expansion chambers 5, an opening diameter of the ducts 4 can be expanded just by the gap, thereby obtaining a noise reduction device for the ventilation path in which gas permeability in the ventilation path configuration 1 can be more improved. |
