| 摘要 |
<p>PROBLEM TO BE SOLVED: To suppress a vibration generated to the peripheral wall by the action of an inner flowing water, and to reduce the noise in a specific frequency scope resulting from the vibration, so as to obtain the feeling of a good noise reducing effect, by providing a noise reducing device at an adequate position of a drain piping. SOLUTION: In a drain collecting pipe 1 used by connecting lateral pipings C and D on the way in the pipe axial direction of a pipe made in the vertical direction, a vibration damping body 2 is provided at the position lower than connecting pipes 12 and 13 in order to connect the lateral pipings C and D, and at the outer side of the peripheral wall of a diameter contraction pipe 11 furnishing a flow straightening plate at the inside. By the action of the damping body 2, the vibration of the peripheral wall of the diameter contraction pipe 11 is suppressed, and a noise in the frequency scope from 2 kHz to 5 kHz resulting from the vibration, that is, the noise of frequency scope entered to the ear of a person easily, is reduced.</p> |
