Method for manufacturing acoustic sound insulation material

Abstract

To provide a method for manufacturing an acoustic sound insulation material that can improve sound insulation performance without requiring installation of a partition.SOLUTION: A method for manufacturing an acoustic sound insulation material 10 by extruding an acoustic tube 12 includes extruding the acoustic tube 12 in a width direction, and sealing an end face of the acoustic tube 12 in an extrusion direction (a width direction) (using a sealing plate 14 or the like).SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a method for manufacturing an acoustic sound insulation material.

Background Art

[0002] There are several solutions for managing or reducing noise. For example, in one solution, acoustic tubes (such as Helmholtz resonators and acoustic metamaterials) are used. The acoustic tubes utilize the internal resonance of the structure to form an acoustic (resonant) sound insulation material that cancels out noise.

[0003] For example, Patent Document 1 discloses a sound insulation structure having an opening, in which a plurality of acoustic tubes (the ends of which are closed) are provided side by side from the side surface of the opening toward the inside of the sound insulation structure main body, and the acoustic impedance on the side surface of the opening is configured to be zero by adjusting the lengths of these acoustic tubes, and a sound insulation structure in which the plurality of acoustic tubes are integrally formed by plastic working a metal material.

[0004] Also, as another structure, a resonant sound insulation material as shown in FIG. 3 has already been proposed by the present inventors. The conventional sound insulation material 110 shown in FIG. 3 includes a plurality of acoustic tubes (acoustic scatterers) 112 for absorbing a target sound, and each acoustic tube 112 includes a housing 113 that defines a channel 113c having an open end and a terminal end consisting of an internal space 113s. The terminal end (internal space 113s) of the channel 113c extends along the length (height direction) of the housing 113. The plurality of acoustic tubes 112 are stacked in the length direction. Further, each acoustic tube 112 includes one or a plurality of spacers (hereinafter also referred to as partitions) 114 that subdivide the channel 113c along the length (height direction) of the housing 113 (between adjacent acoustic tubes).

[0005] Even if a cross-sectional design for sound insulation of the target frequency is carried out using a resonance type sound insulation material as shown in Fig. 3, when the sound insulation material is long, three-dimensional resonance modes are affected and the target sound insulation characteristics cannot be obtained. By using a spacer (partition) to make the resonance type sound insulation material a length at which resonance modes do not occur, the effect as designed can be obtained.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] For the above resonance type sound insulation material, it is necessary to provide a partition to achieve the target length. However, since resonance waves do not occur in the partition part in the acoustic tube, the passing noise cannot be canceled out in antiphase, resulting in a decrease in sound insulation performance.

[0008] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method for manufacturing an acoustic type sound insulation material that does not require a partition and can improve sound insulation performance.

Means for Solving the Problems

[0009] To solve the above problems, the present invention is a method for manufacturing an acoustic type sound insulation material by extrusion molding an acoustic tube, characterized in that extrusion molding is performed in the width direction of the acoustic tube and the end face in the extrusion direction of the acoustic tube is sealed.

Effects of the Invention

[0010] According to the present invention, it is not necessary to provide a partition, and sound insulation performance can be improved.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Mode for Carrying Out the Invention

[0012] Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings.

[0013] In this embodiment, a method for manufacturing an acoustic soundproof material (such as a Helmholtz resonator or an acoustic metamaterial) that cancels noise by utilizing the internal resonance of a structure is proposed. In the conventional method (FIG. 3), in order to ensure the soundproof performance of the acoustic metamaterial arranged on the fence, it is proposed that the soundproof performance can be ensured by installing a partition. However, this method has the demerits that the process of installing the partition increases and that the soundproof performance is not uniform due to the volume of the partition, resulting in a decrease in the overall soundproof performance. In this embodiment, a method for manufacturing an acoustic soundproof material that solves the problems of the process and non-uniform soundproof performance caused by the installation of the partition is proposed.

[0014] Prior to the description of the method for manufacturing an acoustic soundproof material according to the method of this embodiment, the method for manufacturing an acoustic soundproof material according to the conventional method and its problems or issues will be outlined with reference to FIG. 3.

[0015] In the conventional method of FIG. 3, the sound insulation material 110 is manufactured by first producing an elongated (long in the height direction) housing structure 113A (FIG. 3(A)(a)). The housing structure 113A is produced by extruding the material in the height direction. The housing structure 113A includes a channel having an open end extending along the length (height direction) and a terminal end consisting of an internal space. The housing structure 113A (i.e., the housing 113 described later) is made of an acoustically hard material such as metal (e.g., aluminum), glass, plastic, or ceramic.

[0016] Next, the housing 113 is produced by cutting the housing structure 113A in the height direction to a predetermined length L (FIG. 3(A)(b)). The predetermined length L is a length at which resonance modes do not occur (e.g., 0.58 times or less the wavelength of the target frequency). The housing 113 includes a channel 113c having an open end extending along the length (height direction) and a terminal end consisting of an internal space 113s. Also, the acoustic tube 112 is produced by sealing the upper and lower end faces of the housing 113 after cutting (FIG. 3(A)(b)). In the illustrated example, the upper and lower end faces of the housing 113 after cutting are sealed by adhering (fixing) a partition 114 using an adhesive. However, the housing 113 and the partition 114 may be fixed using other manufacturing techniques such as welding depending on the materials. Also, the upper and lower end faces of the housing 113 after cutting may be sealed by embedding a resin or the like (resin embedding). The partition 114 of this acoustic tube 112 subdivides the channel 113c along the height direction of the housing 113. The partition 114 is made of an acoustically hard material such as metal (e.g., aluminum), glass, plastic, or ceramic. The housing 113 and the partition 114 may be made of the same material or different materials.

[0017] Then, by stacking the acoustic tubes 112 in the height direction (the direction in which the channel 113c of the housing 113 extends), an elongated (long in the height direction) sound insulation material 110 is manufactured ((c) in Fig. 3(A)). In the illustrated example, the acoustic tubes 112 (their partitions 114) are fixed by adhering them to each other using an adhesive, but other manufacturing techniques such as welding may be used for fixing depending on the material.

[0018] Also, the elongated bar-shaped sound insulation materials 110 are arranged on a shelf (side by side at a predetermined interval in the width direction) to manufacture a sound insulation wall 115 (Fig. 3(B)).

[0019] The sound insulation material 110 manufactured by the above-described conventional method includes a plurality of acoustic tubes 112 stacked and fixed (adhered, etc.) along the height direction (arranged along the height direction). Each acoustic tube 112 includes a housing 113 having a channel 113c with an open end extending along the height direction and a terminal end including an internal space 113s. Also, each acoustic tube 112 includes a partition 114 that seals the upper and lower end faces of the housing 113. The length L in the height direction of the housing 113 (the interval between the partitions 114) is a length at which a resonance mode does not occur (for example, 0.58 times or less the wavelength of the target frequency).

[0020] Even if a cross-sectional design for sound insulation of the target frequency is performed with a resonance-type sound insulation material as shown in Fig. 3, when the sound insulation material is long, a three-dimensional resonance mode affects it, and the target sound insulation characteristics cannot be obtained. By setting the resonance-type sound insulation material with partitions to a length at which a resonance mode does not occur (for example, 0.58 times or less the wavelength of the target frequency), the effect as designed can be obtained.

[0021] However, since an acoustic soundproofing material on a fence requires the installation of partitions (at intervals of 0.58 times or less the wavelength of the soundproofing frequency), there are the following two problems. That is, since processes such as cutting the extruded material, sealing both ends of the housing (such as resin filling or sealing with an adhesive and a metal plate), stacking and bonding of each acoustic tube occur, the number of processes for installing partitions increases. In addition, since resonance waves do not occur in the acoustic tubes at the partition parts, the noise passing through cannot be canceled out in antiphase, resulting in a decrease in soundproofing performance. Since sound diffracts, sound leaks out from that part (≈ the state where there is a hole in the wall), and the soundproofing performance of the entire soundproof wall decreases (see Fig. 3(B)).

[0022] A method for manufacturing an acoustic soundproofing material according to the method of the present embodiment that solves the above problems or issues will be described with reference to Fig. 1.

[0023] In the method of the present embodiment, the soundproofing material 10 is manufactured by first producing an elongated (long in the height direction) housing structure 13A (Fig. 1(A)(a)). The housing structure 13A is produced by extruding the material in the width direction. The housing structure 13A includes a plurality of channels in the height direction that have open ends extending along the width direction and terminations including internal spaces. That is, in the present embodiment, the housing structure 13A includes a housing 13 including a channel 13c having an open end extending along the width direction and a termination including an internal space 13s, and a plurality of such housings 13 are provided along the height direction. In the present embodiment, the housing structure 13A is produced by cutting the extruded material to a predetermined length L in the width direction (extrusion direction). The predetermined length L is a length at which resonance modes do not occur (for example, 0.58 times or less the wavelength of the target frequency). The housing structure 13A (that is, the housing 13) is made of an acoustically hard material such as metal (such as aluminum), glass, plastic, or ceramic.

[0024] Next, the acoustic tube 12 is fabricated by sealing the end faces in the width direction (extrusion direction) of the housing structures 13A (the housings 13 arranged side by side in the height direction) (Fig. 1(A)(b)). In the present embodiment, the end faces in the width direction (extrusion direction) of the housing structures 13A (the housings 13) are sealed by adhering (fixing) a sealing plate 14 using an adhesive. However, the housing structures 13A (the housings 13) and the sealing plate 14 may be fixed using other manufacturing techniques such as welding depending on the materials. Also, the end faces in the width direction (extrusion direction) of the housing structures 13A (the housings 13) may be sealed by embedding resin or the like (resin embedding). Further, the sealing plate 14 of this acoustic tube 12 may have a shape that seals the end faces of each housing 13 of the housing structure 13A, or may have a shape that seals the end faces of a plurality of housings 13 of the housing structure 13A together as shown in the figure. The sealing plate 14 is made of an acoustically hard material such as metal like aluminum, glass, plastic, or ceramic. The housing 13 and the sealing plate 14 may be made of the same material or different materials. By fabricating a plurality of acoustic tubes 12 along the height direction, an elongated (long in the height direction) sound insulation material 10 is fabricated (Fig. 1(A)(b)).

[0025] Also, the elongated bar-shaped sound insulation materials 10 are arranged on a shelf (side by side in the width direction at a predetermined interval) to fabricate a sound insulation wall 15 (Fig. 1(B)).

[0026] The sound insulation material 10 manufactured by the method of the above-described embodiment includes a plurality of acoustic tubes 12 integrally formed (arranged) along the height direction. Each acoustic tube 12 includes a housing 13 having a channel 13c having an open end extending along the width direction and a terminal end including an internal space 13s. Also, each acoustic tube 12 includes a sealing plate 14 that seals the end face in the width direction of the housing 13. The length L in the width direction of the housing 13 (the interval between the sealing plates 14) is a length at which a resonance mode does not occur (for example, 0.58 times or less of the wavelength of the target frequency).

[0027] That is, in the method of this embodiment, the housing 13 of the acoustic tube 12 is extruded in the width direction using a material such as metal or resin, cut to a predetermined length (0.58 times or less the wavelength of the target frequency), and the end faces in the width direction (extrusion direction) of the housing 13 of the acoustic tube 12 are sealed. Then, the rod-shaped sound insulation materials 10 are arranged on the grid to produce the sound insulation wall 15.

[0028] With this configuration, in the method of this embodiment, since there is no need to provide (insert) a partition, the manufacturing process can be simplified, and the uniformity of the sound insulation performance can be ensured (that is, the sound insulation performance can be improved) (see Fig. 1(B)).

[0029] As described above, the manufacturing method of the acoustic type sound insulation material 10 of this embodiment is a manufacturing method of the acoustic type sound insulation material 10 that extrudes the acoustic tube 12, extrudes it in the width direction of the acoustic tube 12, and seals the end faces in the extrusion direction (width direction) of the acoustic tube 12 (with a sealing plate 14 or the like).

[0030] According to this embodiment, there is no need to provide a partition, and the sound insulation performance can be improved.

[0031] In addition, in the above-described embodiment, the rod-shaped sound insulation materials 10 are arranged on the shelf (side by side in the width direction at a predetermined interval) to form the sound insulation wall 15, but the sound insulation wall 15 may be formed by laying the rod-shaped sound insulation materials 10 on their sides and arranging them side by side in the height direction at a predetermined interval.

[0032] Also, the shapes of each part such as the internal space 13s, the channel 13c, and the outer shape of the housing 13 of the acoustic tube 12 can be any shape according to the frequency to be sound-insulated. For example, instead of the shape (dimensions) shown in Fig. 2(A), the internal space 13s and the channel 13c of the housing 13 of the acoustic tube 12 may have the shape (dimensions) shown in Fig. 2(B).

[0033] In addition, the housing structure 13A (the housing 13 of the acoustic tube 12) for manufacturing the sound insulation material 10 may be formed using other manufacturing techniques such as 3D printing and casting instead of extrusion molding.

[0034] Note that the present invention is not limited to the above-described embodiments, and can be appropriately modified without departing from the object of the present invention.

Industrial Applicability

[0035] The present invention can be used in various industries such as the automotive industry, the industries of daily necessities and consumer goods, the construction industry, and the materials industry.

Explanation of Signs

[0036] 10 Acoustic sound insulation material, 12 Acoustic tube, 13 Housing, 13A Housing component, 14 Sealing plate, 15 Sound insulation wall, 110 Acoustic sound insulation material, 112 Acoustic tube, 113 Housing, 113A Housing component, 114 Partition, 115 Sound insulation wall

Claims

【Claim 1】 A method for manufacturing an acoustic sound insulation material by extruding an acoustic tube, The method for manufacturing an acoustic sound insulation material is to extrude in the width direction of the acoustic tube and seal the end face of the acoustic tube in the extrusion direction.

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