| 摘要 |
<p>PURPOSE:To reduce noise ranging from low frequency to high frequency through a simple and compact device by forming a hydraulic sound reducing device, to reduce hydraulic sound in a construction machine or the like, of a long and a short two closed pipe branched from the outlet piping of a hydraulic pump. CONSTITUTION:In a hydraulic device composed of a hydraulic pump 2, a control valve 3 and a hydraulic cylinder 4 which are connected through piping 5, 6, a hydraulic sound reducing device 1 is provided in a part of the outlet piping 5 of the hydraulic pump 2. The hydraulic sound reducing device 1 is composed of a long and a short two closed pipe 7, 8 branched from the piping 5. Low frequency (for example, 350Hz) sound caused by hydraulic pulsation occurring during the maximum load is absorbed by the long closed pipe 7, and high frequency (for example, 575Hz) sound caused by the hydraulic pulsation during noload is absorbed by the short closed pipe 8.</p> |
