To provide a branch duct silencer with which a sufficient silencing effect can be obtained simply by adding branch pipes to an existing duct.
The branch duct silencer is equipped with main piping 20 arranged between a noise source S and a position G for sound reduction target and the first to the third branch pipes 30, 40 and 50 connected at both ends to the main piping 20. The first branch pipe 30 is so set that the difference δ1 between the length of the main piping 20 from a position 21 to a position 22 attains the first length which is the same as the half wavelength of the sound to be silenced of the noise source S. The difference δ2 between the length of the main piping 20 from a position 23 to a position 24 and the length of the second branch pipe 40 is (1/2) times of δ1 and the difference δ3 between the length of the main piping 20 from a position 25 to a position 26 is (1/4) times of δ1.
| JP2003239717 | SILENCER |
| WO/2016/026890 | VEHICLE NOISE SUPPRESSION METHOD |
| WO/2019/025774 | METHOD AND APPARATUS FOR ENHANCING VEHICLE SOUND AND/OR VIBRATIONS |
EBATO AKIHIKO
KUNO KATSUMI
Satoshi Kono
Makoto Nakamura
Kurata Masatoshi
Sadao Muramatsu
Ryo Hashimoto