Title:
ACTIVE MUFFLER
Document Type and Number:
Japanese Patent JP3507522
Kind Code:
B2
Abstract:
PURPOSE: To reduce the occurrence of a turbulent flow noise by providing a speaker generating a sound wave with an opposite phase on the inside wall surface of a duct and arranging a planar porous elastic body on the sectional part of the duct in an upstream side.
CONSTITUTION: This device is constituted of a wire netting 1 with sufficient large meshes attached to the sectional part of the duct 102 in the upstream side from the position of a first microphone 103 and the planar porous elastic body 2 arranged on the surface of the wire netting 1. In such a case, though air blown out from a blower 101 possesses irregular pulsation and a large eddy and large disturbance, and the distribution in wind velocity in the duct 102 is non-uniform, the irregular pulsation and the large eddy and the large disturbance are reduced when the air passes through the planar porous elastic body 2, and the flow of the air is stabilized in the downstream side from the planar porous elastic body 2.
Inventors:
Hironari Ogata
Yano Chie
Yano Chie
Application Number:
JP9112593A
Publication Date:
March 15, 2004
Filing Date:
April 19, 1993
Export Citation:
Assignee:
Matsushita Ecosystems Co., Ltd.
International Classes:
E04B1/86; F01N1/00; F24F13/02; G10K11/16; G10K11/178; H04R3/00; (IPC1-7): G10K11/178; E04B1/86; F01N1/00; F24F13/02; G10K11/16
Domestic Patent References:
| JP3237208A | ||||
| JP5188976A | ||||
| JP2192541A | ||||
| JP475398U | ||||
| JP58239U | ||||
| JP336299U |
Attorney, Agent or Firm:
Fumio Iwahashi (2 others)
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