JP7315841B2 - Structure - Google Patents

Description

TECHNICAL FIELD The present invention relates to a structure having high sound absorption performance. The structure of the present invention is suitably used as an interior material for automobiles.

Patent Literature 1 discloses a sound-absorbing type soundproofing material for automobiles, which is provided on the floor surface of the passenger compartment or the like in order to make the passenger compartment of the automobile quieter. The sound absorbing type sound insulating material for automobiles described in Patent Document 1 includes a first sound absorbing layer and a second sound absorbing layer made of a fiber material such as felt or glass wool or an expandable synthetic resin material such as urethane foam, and a predetermined basis weight and ventilation. and an intermediate layer made of a nonwoven fabric having a degree of elasticity.

Japanese Patent Application Laid-Open No. 2003-19930

In some cases, a sound absorbing material having a configuration different from that of Patent Document 1 is desired.

The present invention has been made in view of such circumstances, and provides a structure having excellent sound absorption.

According to the present invention, there is provided a structure comprising a hollow molded body and a fibrous sound absorbing body, wherein the hollow molded body has an outer wall and an inner wall spaced apart from each other, and the fibrous sound absorbing body is attached to the inner wall, the outer wall having an outer wall opening, the inner wall having an inner wall opening, the outer wall opening and the inner wall opening communicating with each other A structure is provided that is arranged to.

Since the structure of the present invention has the above configuration, it has excellent sound absorption.

Various embodiments of the present invention are illustrated below. The embodiments shown below can be combined with each other.
Preferably, the structure as described above, wherein the area of the inner wall opening is smaller than the area of the outer wall opening.
Preferably, a structure as described above, wherein the number of said inner wall openings is greater than the number of said outer wall openings.
Preferably, the structure described above includes an adhesive sheet, the fibrous sound absorber is attached to the inner wall via the adhesive sheet, and the adhesive sheet communicates with the inner wall opening. A structure comprising an adhesive sheet opening.
Preferably, in the structure described above, the fibrous sound absorber is a structure without openings.
Preferably, in the structure described above, the hollow molded body comprises a plurality of hollow chambers separated from each other by ribs, and the plurality of hollow chambers are respectively connected to the outer wall opening and the inner wall opening. A structure comprising a part.
Preferably, a structure as described above, wherein said structure is a motor vehicle interior trim and said outer wall is arranged to face the exterior of said motor vehicle.

2 is an exploded perspective view of the structure 1; FIG. 2 is an enlarged view of area A in FIG. 1; FIG. 2 is an exploded perspective view of the structure 1 of FIG. 1 viewed from the side of an outer wall 2a; FIG. Fig. 2 is a perspective view of a hollow molded body 2 extracted from the structure 1 of Fig. 1; 2 is a perspective plan view of the structure 1 of FIG. 1; FIG. FIG. 6 is a cross-sectional view taken along the line AA in FIG. 5;

Embodiments of the present invention will be described below. Various features shown in the embodiments shown below can be combined with each other. In addition, the invention is established independently for each feature.

As shown in FIG. 1, a structure 1 according to one embodiment of the present invention includes a hollow molded body 2, an adhesive sheet 3, and a fibrous sound absorber 4. As shown in FIG. This structure 1 is preferably an automobile interior material, such as a floor panel, and has a certain degree of rigidity. The structure 1 of this embodiment is characterized in that the sound absorbing property is enhanced without impairing the function as an automobile interior material.

As shown in FIG. 2, the hollow molded body 2 has an outer wall 2a and an inner wall 2b that are spaced apart from each other. The structure 1 is envisioned with the outer wall 2a facing the noise (sound wave) source. When the structure 1 is an automobile interior material, the outer wall 2a is arranged toward the outside of the automobile. This suppresses noise from outside the vehicle from being transmitted to the interior space of the vehicle. A hollow portion 2f is provided between the outer wall 2a and the inner wall 2b. The outer wall 2a and the inner wall 2b are connected by a peripheral wall 2c. The thickness of the outer wall 2a and inner wall 2b is, for example, 0.5 to 4 mm, preferably 1 to 3 mm. .5, 3.0, 3.5, 4.0 mm, and may be in the range between any two of the values exemplified herein. The hollow molded body 2 is preferably made of polyolefin such as polyethylene or polypropylene.

The hollow molded body 2 is preferably formed by parison blowing or vacuum forming. A parison is formed by extrusion of molten resin. The parison may be cylindrical or sheet-shaped, and preferably consists of a pair of resin sheets. When the parison is composed of a pair of resin sheets, the uniformity of the thickness of the hollow molded body 2 is excellent, so that the volume of the hollow portion 2f can be increased by reducing the thickness of the whole, thereby improving the sound absorbing performance.

The outer wall 2a and the inner wall 2b respectively have an outer wall opening 2a1 and an inner wall opening 2b1. The openings 2a1 and 2b1 are preferably circular. The openings 2a1 and 2b1 are arranged so as to communicate with each other. According to such a configuration, sound waves entering the hollow portion 2f from the outer wall opening portion 2a1 are attenuated in the hollow portion 2f, so that sound absorption is enhanced. The openings 2a1 and 2b1 can be formed by drilling holes in the chuck 2 using a drill or the like.

The fibrous sound absorber 4 is attached to the inner wall 2b. The fibrous sound absorber 4 is preferably attached to the inner wall 2b via the adhesive sheet 3, but may be attached to the inner wall 2b by means such as an adhesive or welding. In either case, the fibrous sound absorber 4 is preferably attached to the inner wall 2b so as to communicate with the inner wall opening 2b1. This allows attenuation of sound waves over a wide range of frequencies.

The area of inner wall opening 2b1 is preferably smaller than the area of outer wall opening 2a1. The number of inner wall openings 2b1 is preferably greater than the number of outer wall openings 2a1. The total area of inner wall openings 2b1 is preferably smaller than the total area of outer wall openings 2a1. As a result, sound waves entering the hollow portion 2f from the outer wall opening portion 2a1 remain in the hollow portion 2f and are easily attenuated. Also, sound waves are attenuated by friction between the inner peripheral surfaces of the openings 2a1 and 2b1 and the air, but since the areas of the openings 2a1 and 2b1 are different from each other, sound waves of a wide range of frequencies can be attenuated. Furthermore, if the area of the inner wall opening 2b1 is too large, there is a risk of impairing the function as an automobile interior material, but in this embodiment, such a risk is minimized.

The value of (the area of the inner wall opening 2b1/the area of the outer wall opening 2a1) is, for example, 0.01 to 0.5. 0.2, 0.3, 0.4, 0.5, and may be in the range between any two of the values exemplified herein. In this embodiment, this value is 1/9. The value of (the number of inner wall openings 2b1/the number of outer wall openings 2a1) is, for example, 2 to 10, specifically, for example, 2, 3, 4, 5, 6, 7, 8, 9, 10 and may range between any two of the numbers exemplified here. In this embodiment, this value is four. The value of (total area of inner wall opening 2b1/total area of outer wall opening 2a1) is, for example, 0.02 to 0.9. 1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9 and within a range between any two of the numerical values exemplified herein may be In the present embodiment, this value is 4/9. The total area of inner wall openings 2b1 is the total area of one or more inner wall openings 2b1. The same applies to the total area of the outer wall openings 2a1.

As shown in FIG. 3, the hollow molded body 2 preferably has a plurality of hollow chambers 2e partitioned by ribs 2d. This increases stiffness. The ribs 2d are provided so as to extend in the vertical direction and the horizontal direction, and the plurality of hollow chambers 2e are arranged in a grid pattern. As shown in FIG. 5, each hollow chamber 2e preferably has a rectangular shape with rounded corners in plan view. The rib 2d is formed by recessing the outer wall 2a and welding the tip of the rib 2d to the inner wall 2b. For this reason, the outer wall 2a is uneven as shown in FIG. 3, and the inner wall 2b is flat. Therefore, it is easy to attach the fibrous sound absorber 4 to the inner wall 2b. In addition, the rib 2d may be an inner rib in which the side surfaces of the rib 2d are welded together. In this case, the outer wall 2a can also be flat. In addition, if inner ribs are used, the volume of the hollow chamber 2e can be increased and the sound absorption performance can be enhanced.

As shown in FIGS. 2 and 5, each hollow chamber 2e preferably has openings 2a1 and 2b1. The opening 2a1 is preferably arranged in the center of the hollow chamber 2e. Opening 2b1 is preferably arranged to surround opening 2a1 in plan view. The above description of the relationship between the openings 2a1 and 2b1 of the hollow molded body 2 also applies to each hollow chamber 2e. For example, as shown in FIG. 5, the number of inner wall openings 2b1 included in each hollow chamber 2e is preferably greater than the number of outer wall openings 2a1 included in each hollow chamber 2e. is preferably smaller than the total area of the outer wall openings 2a1 included in each hollow chamber 2e. This further increases sound absorption. In addition, the ratio of the diameter of the openings 2a1 to the pitch of the ribs 2d is preferably 0.1 to 0.6, specifically, for example, 0.1, 0.2, 0.3, 0.4, 0 .5, 0.6, and may be in the range between any two of the numbers exemplified herein. In this embodiment, this value is 0.25.

The adhesive sheet 3 preferably has an adhesive sheet opening 3a communicating with the inner wall opening 2b1. The pressure-sensitive adhesive sheet openings 3 a are uniformly distributed over the entire surface of the pressure-sensitive adhesive sheet 3 . In this case, the fibrous sound absorber 4 reliably communicates with the inner wall opening 2b1 through the adhesive sheet opening 3a. The area of each adhesive sheet opening 3a is preferably smaller than the area of each inner wall opening 2b1. The number of adhesive sheet openings 3a is preferably greater than the number of inner wall openings 2b1. The total area of the adhesive sheet openings 3a is preferably smaller than the total area of the inner wall openings 2b1. It is preferable that a plurality of adhesive sheet openings 3a face each inner wall opening 2b1. As a result, the inner wall opening 2b1 and the fibrous sound absorber 4 are reliably communicated with each other. The value of (area of adhesive sheet opening 3a/area of inner wall opening 2b1) is, for example, 0.01 to 0.5, specifically, for example, 0.01, 0.05, 0.1, 0.2, 0.3, 0.4, 0.5, and may be in the range between any two of the values exemplified herein. The value of (the number of adhesive sheet openings 3a/the number of inner wall openings 2b1) is, for example, 2 to 10, specifically, for example, 2, 3, 4, 5, 6, 7, 8, 9, 10 and may range between any two of the numbers exemplified herein. The value of (total area of pressure-sensitive adhesive sheet openings 3a/total area of inner wall openings 2b1) is, for example, 0.02 to 0.9, and specifically, for example, 0.02, 0.05, 0.02, 0.05, 0.05, 0.02, 0.05, 0.05, 0.02, 0.05, 0.02, 0.05, 0.05, 0.02, 0.05, 0.05. 1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9 and within a range between any two of the numerical values exemplified herein may be

The fibrous sound absorber 4 is made of nonwoven fabric, for example. The fibrous sound absorber 4 preferably has no openings. In this case, since the hollow portion 2f becomes a closed space closed on the fibrous sound absorber 4 side, the sound absorption performance is enhanced. Here, the "opening" refers to a portion formed by partially cutting out the fibrous sound absorber 4, and does not include microscopic gaps between fibers included in the fibrous sound absorber 4.

Reference Signs List 1: Structure 2: Hollow molding 2a: Outer wall 2a1: Outer wall opening 2b: Inner wall 2b1: Inner wall opening 2c: Surrounding wall 2d: Rib 2e: Hollow chamber 2f: Hollow portion 3: Adhesive sheet 3a: Adhesive sheet opening 4: fibrous sound absorber

Claims (7)

A structure comprising a hollow molded body and a fibrous sound absorbing body,
The hollow molded body has an outer wall and an inner wall spaced apart from each other , and a plurality of hollow chambers separated from each other by ribs ,
The rib is formed by recessing the outer wall,
The fibrous sound absorber is attached to the inner wall,
the outer wall having an outer wall opening;
the inner wall having an inner wall opening;
A structure wherein said outer wall opening and said inner wall opening are arranged to communicate with each other. The structure of claim 1, comprising:
The structure, wherein the area of the inner wall opening is smaller than the area of the outer wall opening. A structure according to claim 1 or claim 2,
The structure, wherein the number of inner wall openings is greater than the number of outer wall openings. A structure according to any one of claims 1 to 3,
Equipped with an adhesive sheet,
The fibrous sound absorber is attached to the inner wall via the adhesive sheet,
The structure, wherein the adhesive sheet has an adhesive sheet opening that communicates with the inner wall opening. A structure according to any one of claims 1 to 4,
The structure body, wherein the fibrous sound absorber does not have an opening. A structure according to any one of claims 1 to 5,
A structure, wherein each of said plurality of hollow chambers comprises said outer wall opening and said inner wall opening. A structure according to any one of claims 1 to 6,
The structure is an automotive interior material,
A structure, wherein said outer wall is positioned facing out of said motor vehicle.