JP2007302243A - Double wall structure with frame body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a double wall structure with a frame body capable of suppressing any increase of the acoustic transmission to specified frequencies and consistently demonstrating the noise insulation performance for the specified frequencies. <P>SOLUTION: The double wall structure 1 is formed by imagining a door as a part of a passenger car. This double wall structure 1 has plate bodies 2, 3 which are arranged parallel to each other, and opposite to each other with a predetermined distance therebetween. The plate bodies 2, 3 are constituted in a rectangular shape which is slightly longer in one direction. An internal space 4 is formed between the two plate bodies 2, 3 opposite to each other. A side plate 5 is provided so as to connect the plate bodies 2, 3 to each other, and the internal space 4 is substantially closed thereby. A closed space structure 6 having a perforated surface 6a in one surface of a parallelopiped body is provided at the position where the sound pressure in the internal space 4 is increased. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a double wall structure with a frame for isolating sound from a noise generating source with respect to a part having a bag structure in an automobile body, for example, a door, a hood, a trunk lid, and the like.

Conventionally, it has been proposed to use a double wall structure for doors, hoods, trunk lids and the like as parts used in automobiles (see, for example, Patent Documents 1 and 2). The configuration of this conventional example is schematically shown in FIG. In the conventional double-wall structure 1 ′, an internal space 4 is formed between plate-like bodies 2 and 3 facing each other with a predetermined distance, and the internal space 4 is closed by a side plate 5. The structure is a hollow box.
JP 2002-96636 A JP 2003-118364 A

  However, in the double-wall structure 1 ′ as shown in Patent Document 1, when (a) a sound wave of noise is radiated from the lower side and the noise includes a sound component of a specific frequency, the sound component On the other hand, the resonance of the internal space 4 (mainly in the direction parallel to the plate-like bodies 2 and 3) causes the amplitude of the upper plate-like body 3 serving as the radiation surface to increase, resulting in an increase in radiated sound. As a result, the sound insulation performance deteriorated. (B) Alternatively, the double wall structure 1 ′ constitutes a vibration system with the three components of the plate-like body 2 -the air in the internal space 4 (acting as a spring) -the plate-like body 3, but with a specific frequency. For noise, resonance may occur in the vibration system, which deteriorates the sound insulation performance.

  The present invention has been made in view of the above points, and an object thereof is to suppress an increase in the amount of sound transmission with respect to a sound having a specific frequency and to stably exhibit a sound insulation performance for a sound having various frequencies. The object is to provide a double-walled structure.

Means and effects for solving the problem

(1)
The double wall structure with a frame according to the present invention has a double wall structure in which an internal space is formed between the opposing plate-like bodies and an opening is formed in a part of the opposing plate-like bodies. And a closure member that is installed in the opening to completely or substantially close the internal space, and is provided in the closure member and forms a closed space on the internal space side and is porous in at least a part of the internal space side A closed space forming shell provided with a portion having a closed space, and a frame that forms a space on the opposite side of the closing member provided with the closed space forming shell.

In the double wall structure with a frame according to the present invention, a plate-like member having a closed space forming shell is installed in an opening formed in a part of the double wall structure. In addition, the closing here does not mean only exact | strict sealing, but includes the case where it has a partial clearance gap and opening part. Further, the closed space forming shell serving as the sound absorbing mechanism is formed in the vicinity of a portion having a high sound pressure in the resonance state of the internal space.
Further, by providing a frame, a structure similar to a triple wall structure is formed together with a double wall structure composed of opposing plate-like bodies and a closing member.

  In this case, since the internal space of the double-wall structure with a frame is closed, when sound pressure is applied from one of the double-wall structures, the internal space is reduced by the action of resonance generated in the closed space forming shell. The sound pressure can be effectively reduced, and the vibration amplitude of the other plate state of the double wall structure can be effectively reduced. Therefore, the vibration of the frame which is the sound radiation surface to the other side of the double wall structure with a frame is also reduced, and the sound transmission loss of the double wall structure with a frame can be improved.

(2)
The closing member may include a damping member made of a structure or material having vibration damping properties. Note that the damping member includes a plate-like body in which a damping material is laminated, a plate-like body in which a restraint plate is laminated via a damping material, and the like. The closing member includes a plate-like member or a sheet-like body, and the sheet-like body means a material thinner than the plate, for example, a film, a foil, a film, etc., and a metal foil, a resin film, a cloth Or a nonwoven fabric etc. can be used.

  Even when sound pressure excitation is given by this configuration, the closing member itself has vibration damping properties, so that the amplitude of the closing member itself can be reduced and the sound insulation performance can be exhibited stably. As a means for imparting vibration damping properties of the closing member, a plate-like member is a damping member (for example, a damping steel plate, a damping aluminum plate, a damping resin, etc.), or a damping material is applied to the plate-like member. (Damping rubber or other damping resin) may be attached.

(3)
The closing member may include an uneven member. In addition, embossing may be given as an example of an uneven member.

  In this case, it is possible to reduce the amplitude of the plate-like member itself by increasing the rigidity and vibration damping property of the closing member, and to stably exhibit the sound insulation performance.

(4)
The closing member preferably includes a sound absorbing structure or material. In this case, sound absorption by the closing member can be improved, and resonance in the internal space can be reduced, so that sound insulation performance can be exhibited stably.

(5)
The closing member is preferably made of a porous body. Note that the porous body is not limited to a single sheet, and may be composed of a plurality of sheets, or a structure in which a porous body and a porous plate are laminated.

  In this case, sound absorption by the closing member can be improved, and resonance in the internal space can be reduced, so that sound insulation performance can be exhibited stably.

(6)
The closed space forming shell may be formed from a plurality of chambers.

  In this case, since the closed space forming shell is formed from a plurality of small chambers, the specifications (porous diameter, porous plate thickness, air layer thickness, aperture ratio, etc.) can be changed for each small chamber. Suppression can be achieved and sound transmission loss can be improved.

(7)
In the closed space forming shell, a plurality of small chambers may be formed by a partition member.

  In this case, since a plurality of small chambers are formed by the partition member, the specifications (porous diameter, porous plate thickness, air layer thickness, aperture ratio, etc.) can be changed for each small chamber, so that many resonances are suppressed. Sound transmission loss can be improved. The above porous surface is not limited to one, and a plurality of porous surfaces may be formed by lamination or multilayer having a space (gap).

(8)
The closed space forming shell may include an uneven shape.

  In this case, since the closed space forming shell itself includes a concavo-convex shape, it is possible to improve the processing performance at the time of processing such as deep drawing when forming the closed space forming shell, the strength against vibration, and the like. Further, a part of the closed space forming shell may include an uneven shape, or the entire closed space forming shell may be formed with an uneven shape. The uneven shape includes processing by embossing or the like.

  As the porous design conditions, for example, the design conditions described in Japanese Patent Laid-Open No. 2003-050586 can be used. Specifically, the design conditions for the pores on the porous surface of the above-mentioned closed space structure are set so that, for example, the plate thickness, the hole diameter, and the aperture ratio satisfy the design conditions for generating a viscous action in the air flowing through the pores May be.

  As a result of the double wall structure provided with a closed space structure having a porous surface, the conversion of air vibration to thermal energy by viscous action is promoted, so that sufficient sound absorption performance can be reliably exhibited over a wide frequency bandwidth. become. Thereby, in addition to the noise at the resonance frequency, the sound absorption performance is excellent for noise other than this frequency.

  Further, the porous surface of the double wall structure may have a frequency bandwidth with a sound absorption coefficient of 0.3 or more, for example, set to 10% or more with respect to the resonance frequency. Furthermore, the aperture ratio of the porous surface may be 3% or less. Furthermore, the diameter of each hole in the porous surface may be 3 mm or less, and the sound source to be soundproofed may be 70 dB or more.

  The diameter of each hole on the porous surface is more preferably 1 mm or less. In addition, the hole diameter based on this invention can be used even if the diameter of each hole of a porous surface is 0.2 mm or less because it is provided in a closed space structure.

  The closed space forming shell is not limited to a closed space formed by a plurality of planes, and the closed space may be formed by a curved surface. For example, a closed space forming shell made of a sphere or a closed space forming shell made of a part of a sphere may be used.

  Next, embodiments of the invention will be described. In the present embodiment, a closed space structure will be described as an example of a closed space forming shell. Moreover, the Example and reference example of a double wall structure are each shown by FIGS. 1-20, and the effect of a double wall structure is shown by FIGS. 21-23. In the following, description will be given in order.

  FIG. 1 is a schematic perspective view showing a reference example of a double wall structure. The double wall structure 1 of Reference Example 1-1, whose schematic diagram is shown in FIG. 1, is assumed to be a door as a passenger car part.

  The double wall structure 1 includes plate-like bodies 2 and 3 which are arranged in parallel and are opposed to each other at a predetermined distance. The plate-like bodies 2 and 3 are formed in a rectangular shape that is slightly longer in one direction, and an internal space 4 is formed between the two opposing plate-like bodies 2 and 3. A side plate 5 is provided so as to connect the plate-like bodies 2 and 3 to each other, whereby the internal space 4 is substantially closed. In other words, the double wall structure 1 of the present embodiment is configured in a box shape surrounding the internal space 4 with the plate-like bodies 2 and 3 that are double walls and the side plates 5.

  And in this embodiment, the closed space structure 6 which has the porous surface 6a in one surface of a rectangular parallelepiped shape is provided in the position where the sound pressure in the internal space 4 is large. As a material for the closed space structure 6 having the porous surface 6a, for example, any material that can form a plate state such as iron, aluminum, resin, paper, or a foil-like body having porosity can be used.

  In the present embodiment and the reference example, the closed space structure 6 has a rectangular parallelepiped shape and has an independent internal space (hereinafter referred to as a closed space). The lower ends of the three closed space structures 6 are disposed in contact with the inner space 4 and on the surface of the plate-like body 2 on the vibration side. Specifically, the closed space structure 6 and the plate-like body 2 are joined by bonding with an adhesive or the like. The porous surface 6a does not necessarily have to be parallel to the plate-like bodies 2 and 3. Moreover, it is not limited to providing the three closed space structures 6, You may use the structure which provides the one large closed space structure 6, and divides the inside into three.

  In determining the installation position of the porous surface 6a, the position where the sound pressure increases due to resonance in the internal space 4 is obtained by numerical calculation by the finite element method or the boundary element method, or an actual structure is manufactured and It is determined by measuring the sound absorption performance and arranged at that position. However, since the position theoretically obtained by calculation and the position where the sound-absorbing effect is actually the highest do not coincide with each other, there is often a deviation, so the position where the closed space structure 6 is actually arranged is the sound pressure. It is not strictly limited to the position where the value becomes large, and may be a position in the vicinity thereof.

  In the present embodiment, the closed space structure 6 is provided on the plate-like body 2 side. However, the present invention is not limited to this and may be provided on the plate-like body 3 side.

  In the above configuration, when sound pressure is applied from the upper side to the plate-like body 3 side, the plate-like body 3 vibrates and resonance occurs in the closed space structure 6. At this time, the sound pressure in the closed space decreases in the closed space structure 6. Therefore, since the amplitude of the lower plate-like body 2 serving as the radiation surface is reduced, the sound emitted from the plate-like body 2 can be reduced and the sound transmission loss of the double wall structure can be improved.

  FIG. 2 shows a reference example 1-2. In this configuration, four closed space structures 6 are arranged in the vertical and horizontal directions (two each in the longitudinal direction and the lateral direction). That is, since the number of the closed space structures 6 is larger than that in Reference Example 1-1, the area of the closed space and the porous surface 6a is increased, and the sound transmission loss can be improved.

  FIG. 3 shows Reference Example 1-3. In this configuration, porous surfaces 6 a and 6 b are formed in the closed space structure 6. Therefore, since the areas of the porous surfaces 6a and 6b of the four closed space structures 6 are increased, the sound transmission loss can be further improved. In this case, not only the longitudinal direction of the plate-like bodies 2 and 3 but also the resonance in the width direction can be suppressed. In other words, the resonance can be suppressed in the two sound pressure mode directions. The number of closed space structures 6 is not limited to three or four, and an optimum number may be determined in consideration of the resonance mode of the double wall structure 1 due to assumed noise. . Furthermore, the hole diameters of the porous surfaces 6a and 6b may be adjusted optimally.

  FIG. 4 shows a part of the embodiment 2-1 of the present invention, and in this configuration, an opening 2b is provided in a part of the plate-like body 2a on the vibration side. A plate-like body 7 that is one of the closing members is provided so as to close the opening 2 b, and the closed space structure 6 is joined on the surface of the plate-like body 7. That is, the closed space structure 6 and the plate-like body 7 are joined with an adhesive or the like. Other examples of this joined state will be described later.

  In the above configuration, when sound pressure is applied from the upper side to the plate-like body 3 side, the plate-like body 3 vibrates and resonance occurs in the internal space 4. The closed space structure 6 reduces the sound pressure in the closed space. Therefore, since the amplitude of the lower plate-like bodies 2a and 7 which are the radiation surfaces is reduced, the radiated sound from the plate-like bodies 2a and 7 is reduced and the sound transmission loss of the double wall structure can be improved.

  FIG. 5 shows a part of the embodiment 2-2 of the present invention. The part of the embodiment 2-2 of the present invention is a reference example 1-2 and a part of the embodiment 2-1 of the present invention. Is equivalent to a combination of That is, four closed space structures 6 are arranged in the vertical and horizontal directions (two each in the longitudinal direction and the short direction), and are joined on the surface of the plate-like body 7. In this configuration, the number of the closed space structures 6 is larger than that in the case of a part of Example 2-1 of the present invention, so that the area of the closed space and the porous surface 6a is increased and the sound transmission loss can be improved.

  FIG. 6 shows a part of the embodiment 2-3 of the present invention. The part of the embodiment 2-3 of the present invention is a reference example 1-3 and a part of the embodiment 2-1 of the present invention. Is equivalent to a combination of That is, the closed space structure 6 has the porous surfaces 6a and 6b, and the four closed space structures 6 are arranged in the vertical and horizontal directions (two each in the longitudinal direction and the short direction) to form a plate-like body. 7 is in contact with and adhered to the surface. In this configuration, since the areas of the porous surfaces 6a and 6b of the four closed space structures 6 are increased, the sound transmission loss can be improved. In this case, not only the longitudinal direction of the plate-like bodies 2 and 3 but also the resonance in the width direction can be suppressed. In other words, the resonance can be suppressed in the two sound pressure mode directions. The number of closed space structures 6 is not limited to three or four, and an optimum number may be determined in consideration of the resonance mode of the double wall structure 1 due to assumed noise. .

  FIG. 7 shows some embodiments 2-4 of the present invention. In this structure, the embossing which has an uneven shape is given to the surface of the plate-shaped body 7 of some Examples 2-3 of this invention. Therefore, the rigidity of the plate-like body 7 can be increased. By using this highly rigid plate-like body 7a that is embossed, the workability of the plate-like body 7a can be improved and the sound absorption can be improved. In addition, in this example, although embossing was demonstrated as a representative example of uneven | corrugated shape, it is not limited to this, You may form other arbitrary uneven | corrugated shapes.

  Further, FIG. 8 shows a part of Example 2-5 of the present invention. In this configuration, a damping material is provided on the surface of the plate-like body 7 of Example 2-3 of the present invention. 7b is pasted. Therefore, vibration is reduced by the damping material of the plate-like body 4b provided on the radiation surface side. As a result, sound transmission loss can be improved.

  FIG. 9 shows some embodiments 2-6 of the present invention. In this configuration, a perforated plate 7c is used instead of the plate-like body 7 of some embodiments 2-3 of the present invention.

  In this configuration, when sound pressure is applied from the upper side to the plate-like body 3 side, the plate-like body 3 vibrates and resonance occurs in the internal space 4. At this time, the sound pressure in the internal space 4 is reduced by the closed space structure 6 and the porous body 7c. Therefore, since the amplitude of the lower plate-like bodies 2 and 7c, which are the radiation surfaces, is reduced, the radiated sound from the plate-like bodies 2 and 7c can be reduced and the sound transmission loss of the double wall structure can be improved. .

  FIG. 10 shows some embodiments 2-7 of the present invention. In this configuration, the material of the plate-like body 7 of some embodiments 2-3 of the present invention is composed of the porous body 7d. For example, examples of the porous body 7d include a sound-absorbing material composed of a fiber system such as glass wool and pet resin fiber, or a foamed body such as urethane composed of open cells. In addition, although all the plate-shaped bodies 7 shall consist of the porous body 7d, it is not limited to this, A part of laminated thin film structure may be made into the porous body 7d, and may be used in combination with a porous board.

  In this configuration, the sound absorption is improved by the porous body 7 d of the plate-like body 7. Further, at this time, the sound pressure in the internal space 4 is lowered by the closed space structure 6 and the porous body 7d. Therefore, since the amplitude of the lower plate-like bodies 2 and 7d as the radiation surface is further reduced, the radiated sound from the plate-like bodies 2 and 7d is further reduced and the sound transmission loss can be improved.

  Subsequently, FIG. 11 shows Example 3-1. In this configuration, a double wall structure with a frame body, to which a frame body 1c composed of a plate-like body 2c and a side plate 5c is attached from below the double wall structure body 1 of some of the embodiments 2-1 of the present invention. It shows the body. By attaching the frame 1c, the plate 7 is sandwiched between the plates 2a and 2c. The frame 1c is attached so that a gap is provided between the plate-like bodies 2a and 7 and the plate-like body 2c.

  With this configuration, the sound in the internal space 4 is sounded by the closed space structure 6 that is bonded and fixed to the plate-like member 7 when the plate-like body 3 vibrates in response to the sound pressure excitation applied from the plate-like body 3 side. The pressure is reduced. Since the amplitude of the lower plate-like body 2c which is the radiation surface is reduced, the sound transmission loss of the double wall structure can be improved.

  Next, the internal structure of the closed space structure 6 will be described. 12 to 15 are explanatory views of the internal structure of the closed space structure 6.

  FIG. 12 is a schematic cross-sectional view showing a case where the closed space structure 6 is formed in a part of the plate-like body 2. In this case, the lid member 61 is provided along the surface of the plate-like body 2. In addition, when the configuration of FIG. 12 is applied to some of the embodiments 2-1 to 2-7 and this embodiment of the present invention, a closed space is provided in a part of the plate-like body 7 instead of the plate-like body 2. The structure 6 will be formed.

  FIG. 13 is a schematic cross-sectional view showing a case where the closed space structure 6 is formed in a part of the closed space structure support member 6c.

  In this case, the closed space structure support member 6 c is provided substantially parallel to the plate-like bodies 2 and 7. In this case, a gap may be provided between the closed space structure support member 6c and the plate-like bodies 2 and 7, and conversely, no gap may be provided.

  FIG. 14 is a schematic diagram showing a case in which one surface of the closed space structure 6 is open and formed so that one surface of the closed space structure 6 is substantially closed by the plate-like bodies 2 and 7. It is sectional drawing.

  In this case, a part of the closed space structure 6 is screwed to the plate-like bodies 2 and 7. Therefore, the rigidity of the closed space structure 6 can be increased.

  Next, FIG. 15 is a schematic cross-sectional view showing a case where the closed space structure 6 is formed of a rectangular parallelepiped having the internal space 4.

  In FIG. 15, the closed space structure 6 is bonded onto the surfaces of the plate-like bodies 2 and 7 by an adhesive 80.

  12 to 15, the closed space structure 6 is fixed on the surface of the plate-like bodies 2 and 7, so that the plate-like body 3 side extends from the upper side of the double wall structure 1. When the sound pressure is applied, the plate-like body 3 vibrates and resonance occurs in the internal space 4. At this time, the sound pressure in the internal space 4 is reduced by the closed space structure 6. Therefore, since the amplitude of the lower plate-like body 2 which is the radiation surface is reduced, the radiated sound from the plate-like body 2 is reduced and the sound transmission loss of the double wall structure can be improved.

  Next, FIGS. 16 to 20 are schematic cross-sectional views for explaining the shape of the closed space structure 6.

  FIG. 16 is a schematic cross-sectional view showing a case where the closed space structure 6 is formed from a rectangular parallelepiped.

  As shown in FIG. 16, it is preferable that the porous surface 6 a is formed substantially parallel to the plate-like body 2 as in Reference Example 1-1. Moreover, the porous surface 6b may be formed with the porous surface 6a substantially perpendicularly to the plate-like body 2 as in Reference Example 1-3 (not shown).

  FIG. 17 is a schematic cross-sectional view showing a case where the closed space structure 6 is formed from a hemisphere.

  In this case, the porous surface 6a is formed on almost the entire surface of the hemispherical closed space structure 6x. In FIG. 17, the hemispherical closed space structure 6x has been described. However, the present invention is not limited to this, and a closed space structure made of any other curved surface such as an ellipse may be used. Moreover, although the porous surface 6a was formed in the whole surface, it is not limited to this, It is good also as forming the porous surface 6a in a part.

  Next, FIG. 18 is a schematic cross-sectional view showing a case where the closed space structure 6 is formed from a polyhedron.

  In this case, the porous surface 6a is formed on almost the entire surface of the polyhedral closed space structure 6y. In addition, in FIG. 18, although the polyhedral closed space structure 6y was demonstrated, it is not limited to this, A closed space structure may be formed from a part of polyhedral closed space structure 6y. Furthermore, although the porous surface 6a is formed on the entire surface, the present invention is not limited to this, and the porous surface 6a may be formed on a part thereof.

  FIG. 19 is a schematic cross-sectional view showing a case where the closed space structure 6 is formed from a triangular pyramid.

  In this case, the porous surface 6a is formed on substantially the entire surface of the triangular pyramid closed space structure 6z. In FIG. 19, the triangular pyramid closed space structure 6z has been described. However, the present invention is not limited to this, and the closed space structure may be formed from a part of the triangular pyramid closed space structure 6z. Although the porous surface 6a is formed on the entire surface, the present invention is not limited to this, and the porous surface 6a may be formed on a part thereof.

  FIG. 20 is a schematic cross-sectional view showing a case where the closed space structure 6 is formed from a true sphere.

  In this case, the porous surface 6a is formed in almost a part of the true spherical closed space structure 6R. The true spherical closed space structure 6 </ b> R is bonded and fixed to the plate-like bodies 2 and 7 with an adhesive 80.

  In addition, in FIG. 20, although the true spherical closed space structure 6R was demonstrated, it is not limited to this, A closed space structure may be formed from a part of true spherical closed space structure 6R. Although the porous surface 6a is partially formed, the present invention is not limited to this, and the porous surface 6a may be formed on the entire surface.

  In order to confirm the effectiveness of the above embodiment, the following experiment was performed. In other words, the reverberation chamber composed of the sound source chamber and the sound receiving chamber is used as the double wall structure 1 having the structure of each of the reference examples 1-1 to 1-3 and some embodiments 2-1 to 2-7 of the present invention. Is installed at a position between the two chambers, generates appropriate noise from one side of the double wall structure 1 based on JIS A1416, and uses a sound level meter on both sides of the double wall structure 1 for sound pressure. Was measured to determine sound transmission loss.

  The results are shown in FIGS. Each of the graphs of FIGS. 21 to 23 also shows the result of a similar experiment performed on the structure of the conventional example (FIG. 24). As shown in the graphs of the drawings, in the conventional example, a drop in sound transmission loss is observed in the frequency region near 315 Hz, and it is estimated that resonance or resonance occurs in this portion.

  On the other hand, in the configurations of the respective reference examples and embodiments of the present invention, the sound pressure is reduced by the closed space structure 6 having the porous surface 6a at the position where the sound pressure increases, or the resonance of the vibration system is reduced. As a result, it can be seen that the sound insulation performance can be improved.

  The preferred embodiments of the present invention have been described above, but the technical scope of the present invention is not limited to the above embodiments, and various modifications can be made.

  For example, the double wall structure 1 with a frame of the present invention can be applied not only to a door of a passenger car but also to, for example, a hood and a trunk lid. Further, the shape of the plate-like bodies 2 and 3 is not limited to the rectangular shape as described above, and it goes without saying that various changes can be made according to the shape of the required component.

  In addition, the porous surface 6 is joined to the plate member 2 on the excitation side. However, the present invention is not limited to this, and the porous surface 6 and the plate member 3 on the radiation surface side may be joined.

  Further, the direction of the sound pressure mode (in other words, the direction of the porous surface 6) may be arbitrarily determined in consideration of various circumstances such as the positional relationship with the noise source.

  Furthermore, as the porous body 7d, for example, polyurethane or open-cell foamed material can be used in addition to the glass wool and felt described above. Moreover, it is preferable that the through-hole of the perforated plate 7c is fine so that the viscous action of the air passing through the hole can be expected.

  Although the present invention has been described in the above preferred embodiments, the present invention is not limited thereto. It will be understood that various other embodiments may be made without departing from the spirit and scope of the invention. Furthermore, in this embodiment, although the effect | action and effect by the structure of this invention are described, these effect | actions and effects are examples and do not limit this invention.

Schematic perspective view of Reference Example 1-1 of the double wall structure of the present invention Schematic perspective view of Reference Example 1-2 Schematic perspective view of Reference Example 1-3 Schematic perspective view of Example 2-1 Schematic perspective view of Example 2-2 Schematic perspective view of Example 2-3 Schematic perspective view of Example 2-4 Schematic perspective view of Example 2-5 Schematic perspective view of Example 2-6 Schematic perspective view of Example 2-7 Examples of a double wall structure with a frame according to the present invention Schematic diagram showing an example of a cross section of a closed space structure Schematic diagram showing an example of a cross section of a closed space structure Schematic diagram showing an example of a cross section of a closed space structure Schematic diagram showing an example of a cross section of a closed space structure Schematic diagram showing an example of a cross section of a closed space structure Schematic diagram showing an example of a cross section of a closed space structure Schematic diagram showing an example of a cross section of a closed space structure Schematic diagram showing an example of a cross section of a closed space structure Schematic diagram showing an example of a cross section of a closed space structure The figure which shows the effect of the double wall structure of this invention The figure which shows the effect of the double wall structure of this invention The figure which shows the effect of the double wall structure of this invention Schematic perspective view of a conventional double wall structure

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Double wall structure 2,2c, 3,7,7a Plate-like body 4 Internal space 5,5c Side plate 6 Closed space structure 6a, 6b Porous surface 7b Damping material 7c Porous surface plate 7d Porous body

Claims (8)

A double wall structure in which an internal space is formed between the opposing plate-like bodies and an opening is formed in a part of the opposing plate-like bodies;
A closing member capable of completely or substantially closing the internal space by being installed in the opening;
A closed space forming shell provided on the closing member and forming a closed space on the inner space side and at least part of which is porous on the inner space side;
A double wall structure with a frame, comprising: a frame that forms a space on the opposite side of the closure member provided with the closed space forming shell. The closure member is
The double wall structure with a frame according to claim 1, further comprising a damping member made of a structure or material having vibration damping properties. The closure member is
The double wall structure with a frame according to claim 1 or 2, wherein the double wall structure includes an uneven shape. The closure member is
The double wall structure with a frame according to any one of claims 1 to 3, comprising a structure or a material having sound absorbing properties. The closure member is
It consists of a porous body, The double wall structure with a frame of any one of Claim 1 thru | or 4 characterized by the above-mentioned. The closed space forming shell is:
The double wall structure with a frame according to any one of claims 1 to 5, wherein the double wall structure is formed of a plurality of small chambers. The closed space forming shell is:
The double wall structure with a frame according to any one of claims 1 to 6, wherein a plurality of small chambers are formed by the partition member. The closed space forming shell is:
The double wall structure with a frame according to any one of claims 1 to 7, wherein the double wall structure includes a concavo-convex shape.

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