JPS5963314A - Noise suppressor - Google Patents

Abstract

PURPOSE:To reduce the noise level in a range of wide frequency range by forming two expansion parts and one contraction part which are made of a member through which air is allowed to partially pass, inside a noise suppressor and defining a resonant space at the contracted part. CONSTITUTION:The external casing 1 of a noise suppressor is made of zinc iron board, for example, having one millimeter thickness and involves a buffle cone 2 made of punched metal or the like through which air is allowed to apartially pass. Lamination 3 of long-fiber glass wool is formed on the surface of the buffle cone 2. A resonant space 5 is defined between the external casing 1 and a molded member 4 which is mounted inside the external casing and made of the same punched metal or the like. Lamination of short-fiber glass wool is formed on the internal wall of the external casing 1 except the surface of the resonant space 5.

Description

[Detailed description of the invention] The present invention provides a novel sound deadening device (Vl).

Dry Iff: Noise generated from a mechanical device such as a compressor or a fan is emitted from a furnace discharge port or an air conditioner discharge port. Various types of muffling devices have been developed to remove such noise, but since the noise l/c generated from the mechanical devices mentioned above includes components that fall within a wide range of frequencies, However, it is not possible to sufficiently reduce the noise level. The present invention has been devised in view of these shortcomings in the prior art, and its purpose is to provide a muffling device with a muffling section that utilizes a resonance effect, thereby achieving sound muffling with excellent muffling characteristics over a required frequency range. You are on your way to getting the equipment.

A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a side sectional view of an embodiment of a silencer according to the present invention.
Therefore, 1 in the figure indicates the outer box. This outer box J is, for example, l
Made of mm thick galvanized iron plate. In addition, 2 is a buckle cone made of a material such as punching metal (which can partially circulate KQ air), and its surface has a length e and a layer 3 of fiber glass is formed. 4 in the figure is a baffle cone. A resonance space 5 is formed between this molded member 4 and the outer box 1 using a molded member made of punched metal similar to 2.

In addition, the resonance space 50 is excluded (the inner wall of the outer box 1 is covered with a layer 6 of short fiber glass coated with a surface scattering prevention coating).
is formed. Note that the width a of the silencer is wider than the width of the input opening and the width C of the output opening.Next, the function of the silencer shown in FIG. 1 will be explained. The air containing noise flowing in through the population area d
It expands and depressurizes. In the middle part e and d (
・After being contracted by −C, it expands by °C into the rear chamber f. After that, external penis is supplied through the opening of the outlet part. That is, the air flowing in through the inlet opening repeats expansion and contraction (directing toward the outlet opening DK. During this time, frequency components below, for example, 5 (10 ■ I7) are reduced. Since the inner wall of the device and the outer wall of the baffle cone 2 are provided with layers 3 and 6 of short fiber glass wool, sound waves having a frequency of, for example, 1000 Hz or higher are absorbed by the short fiber glass wool layers 3 and 6.

Furthermore, since the internal space of the Z full cone 2 formed of en-ching metal forms a resonant space, approximately 500~
Noise with a frequency between L (l n OJj7 resonates in the internal space of the Noctful Cone 2 and also resonates with the resonance space "5". Therefore, it is efficient (noise energy is converted into vibration and thermal energy). Figure 2 is a side sectional view of a muffler according to another embodiment of the present invention. The distance Nf is small and the width a is wide.Therefore, the resonance space 2'.

The volume of 51 should also be adjusted in consideration of the overall sound absorption characteristics.

In addition, if the human-powered air contains high noise of l/bel at a specific frequency, it is also possible to design the system to particularly reduce the noise at this frequency.

As described above, since the present invention provides a sound absorbing section that utilizes the resonance effect, it is possible to obtain a sound muffling device M' having the required sound absorbing characteristics.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view of an embodiment of a silencer according to the present invention;
FIG. 2 is a side sectional view of another embodiment of the silencer i according to the present invention. Here, 1...Outer box, 2...Nonotsu full corn, 3
．． 6... Layer of short fiber glass core, 5... Resonance space. Patent mFrn Representative of Asahi Kiki Co., Ltd. Patent attorney Yasunori Inuzuka

Claims (1)

[Scope of Claims] 1. A silencer comprising a resonant space partially constructed of a member through which air can circulate. 2. A silencer as claimed in claim 1, comprising two expansion sections and one contraction section. 3. The muffling device according to claim 2, wherein a resonance space is formed in the contracted portion. 4. The muffling device according to claim 3, characterized in that one expansion part is provided with a baffle cone having a cone-shaped part with a resonant space formed inside. 5. The muffling device according to claim 4, excluding the resonance space (even if a layer of short fiber glass core is formed in the portion facing the passage! It is a feature).