JP2001249666A - Sound absorbing and sound insulating structure and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sound absorbing and sound insulating structure which has a high sound absorption characteristic over a wide frequency range, is light in weight and has good rigidity and a method for manufacturing the sound absorbing and sound insulating structure which is capable of controlling the structure so as to have the sound absorption characteristic. SOLUTION: This sound absorbing and sound insulating structure has a resin molding having a plurality of closed blind cavities having apertures on the front or rear surface and a sound absorbing material and is formed by packing the sound absorbing material into the blind cavities and/or coating the same with the sound absorbing material. The sound absorbing and sound insulating structure described above is provided with air layers between the coated sound absorbing material and the surface where the apertures exist. When the sound absorbing and sound insulating structure formed by packing the sound absorbing material into the blind cavities is manufactured, the pressure in the blind cavities is reduced to pack the sound absorbing material therein. The sound absorbing material is pressurized and packed into the blind cavities.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sound-absorbing and sound-insulating structure, and more particularly, to a resin molded article having a plurality of independent blind cavities having openings on the front surface or the back surface. The present invention relates to a sound-absorbing / sound-insulating structure formed by filling and / or covering a material, and a method for manufacturing the same. The sound-absorbing and sound-insulating structure of the present invention has high sound-absorbing characteristics in a wide frequency range, is lightweight and has good rigidity, and can be controlled to have desired sound-absorbing characteristics in the production method of the present invention.
Such a sound absorbing / insulating structure is suitable, for example, as an outer plate material or an interior material for an automobile.

[0002]

2. Description of the Related Art Heretofore, a sound absorbing / sound insulating structure using a lightweight resin molded body having a sound absorbing characteristic (resonant sound absorbing mechanism) has required an extremely large volume like a resonator (resonator). Was. For this reason, it was not possible to install such a sound absorbing / sound insulating structure in a small space or a site where it is impossible to secure a sufficient space. In addition, one resonator having a large volume has one sound absorption peak, and in order to obtain sound absorption performance in a wide frequency range, it is necessary to prepare several resonators with different volumes. Further, a sheet-shaped molded product represented by an outer plate material or an interior material is often formed by a blow molding method which is relatively easy to form. However, such blow molding gives a blind cavity to the sheet-shaped molded product. It was impossible.

On the other hand, Japanese Patent Application Laid-Open No. 10-018471 discloses a technique for providing a sheet-shaped resin molded article with sound absorbing / sound insulating properties utilizing a resonance sound absorbing mechanism and controlling the sound absorbing properties. Suction-molded laminated
A sound insulation structure is disclosed. Further, Japanese Patent Application Laid-Open No.
No. 024 discloses a sound absorbing / sound insulating structure in which a plurality of perforated plates are stacked.

[0004]

However, in these sound absorbing and sound insulating structures, since a hollow portion is formed as a laminate, a procedure of bonding and welding is required separately from the forming. Was. Further, in these sound absorbing and sound insulating structures, there is a problem that it is necessary to prepare many spaces of different sizes in order to obtain sound absorbing performance in a wide frequency range.

The present invention has been made in view of the above-mentioned problems of the prior art, and an object of the present invention is to provide a light-absorbing material having high sound absorbing characteristics in a wide frequency range, light weight and good rigidity. An object of the present invention is to provide a sound insulating structure and a method for manufacturing the sound absorbing and sound insulating structure that can be controlled to have sound absorbing characteristics.

[0006]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, by filling and / or coating a sound absorbing material into a blind cavity provided in a resin molded article. The inventors have found that the above problems can be solved, and have completed the present invention.

That is, the sound absorbing and sound insulating structure of the present invention is a sound absorbing and sound insulating structure provided with a resin molded body having a plurality of independent blind cavities having openings on the front surface or the back surface, and a sound absorbing material. The sound absorbing material is filled and / or covered in the blind cavity.

The preferred embodiment of the sound-absorbing / sound insulating structure of the present invention is represented by the following formula (1).

[0009]

(Equation 2)

(In the formula, _fr is the resonance sound absorption peak frequency [Hz], c is the sound velocity [m / s], d is the opening diameter [mm], D is the distance between the opening center points [mm]. , L is the depth [mm] of the blind cavity and t is the depth of the surface layer [mm]
Is satisfied).

In another preferred embodiment of the present invention, the sound absorbing material is coated on the blind cavity, and an air layer is provided between the coated sound absorbing material and the surface where the opening is present. Is provided.

Further, the method of manufacturing a sound-absorbing and sound-insulating structure according to the present invention is characterized in that, when manufacturing the above-mentioned sound-absorbing and sound-insulating structure, the sound-absorbing material is filled in the blind cavity. The inside of the blind cavity is decompressed, and the sound absorbing material is filled.

The method of manufacturing a sound-absorbing and sound-insulating structure according to the present invention is directed to manufacturing the sound-absorbing and sound-insulating structure, wherein the sound-absorbing material is filled in the blind cavity. The inside is filled with the above sound absorbing material under pressure.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the sound absorbing and sound insulating structure of the present invention will be described in detail. As described above, the sound-absorbing and sound-insulating structure of the present invention includes a resin molded body having a plurality of independent blind cavities having openings on the front surface or the back surface, and a sound-absorbing material.

Here, the resin constituting the portion other than the blind cavity in the resin molded body, that is, the raw material resin constituting the resin molded body, may be a resin which has fluidity during hot molding, and may be a thermoplastic resin. Any of a resin and a thermosetting resin can be used. In particular, it is preferable to use a thermoplastic resin which can easily adjust the viscosity of the resin by heating and can easily set the formation time of a blind cavity having an opening.

The use of a thermoplastic resin makes it easy to set the time for forming a blind cavity. Therefore, a thermoplastic resin generally used in general injection molding, injection compression molding, compression molding, extrusion molding, stamping molding and the like is used. Specifically, polyolefin resins such as polyethylene and polypropylene, polystyrene, polycarbonate, acrylonitrile-styrene-butadiene block copolymer, general thermoplastic resins such as nylon, ethylene-propylene block copolymer, styrene Examples thereof include thermoplastic elastomers such as butadiene block copolymers, and polymer alloys thereof.

On the other hand, when a thermosetting resin is used, curability can be adjusted by selecting a catalyst type, a catalyst amount, a heating temperature, and the like. These thermoplastic resins and thermosetting resins include talc, glass beads, silicon oxide, coloring pigments, metal powder, calcium carbonate, glass fibers, polyamide fibers, carbon fibers, light stabilizers, lubricants, antistatic agents. ,
Various additives such as a filler such as an antioxidant and a fiber reinforcing agent can be appropriately added.

Further, a plurality of blind cavities provided in the resin molded body exist independently of each other, and the openings of these blind cavities face the front surface or the back surface of the resin molded body. In other words, such a blind cavity is, in the fat molding,
It means a cavity that does not penetrate between the front surface and the back surface, and the blind cavities are not in contact with each other, each forming an independent space. The blind cavity typically extends and expands in a direction from the surface (front surface or back surface) where the opening is present (surface or back surface) to the opposite surface (back surface or front surface). It has an elliptical spherical shape, eggplant-shaped or naked bulb-shaped hole shape. In this specification, any one surface of the resin molded body is referred to as a “front surface”, and the other surface is referred to as a “back surface”.
The two are not essentially different from each other, and are for convenience of explanation. Even if both are described interchangeably, it goes without saying that they belong to the scope of the present invention.

Further, as the above-mentioned sound absorbing material, any material can be used as long as it can impart desired sound absorbing characteristics.
It is preferable to use an inorganic fiber or a foam or a foam material as the sound absorbing material. Specifically, PET, PBT, PE
Examples include organic fibers such as N and felt, inorganic fibers such as glass-based materials, foams and foams such as urethane, PP, and epoxy, and natural fibers such as cotton. It should be noted that a sound absorbing material in which these are arbitrarily combined may be used.

Here, a mold and a molding method for molding the resin molded article having the blind cavity will be described with reference to the drawings.

FIGS. 1 and 2 show one embodiment of a mold for molding a resin molded body. 1 shows a state before the material resin is injected, and FIG. 2 shows a state where the material resin is injected into the cavity and a pressure medium (heated compressed air) is injected to form a blind cavity. Is shown.

In FIGS. 1 and 2, the molding die is
A cavity defined by a concave portion of the movable mold 2 and a convex portion of the fixed mold 1 is provided on a back surface forming wall portion 1a having a movable mold 2 and a fixed mold 1 and forming a convex portion of the fixed mold 1. 4 to raw resin 12
And a pressure medium injection part 5 for injecting a pressure medium into the cavity 4 are separately provided. The pressure medium injection unit 5 is connected via a gas chamber 3 to a gas cylinder 7, a pressure adjustment valve 8, a control valve 9 capable of controlling injection time, and a heating device 10. On the other hand, the resin injection port 6 passes through the center of the fixed mold 1 and is connected to a raw resin system (not shown).

When molding a resin molded body using the above-described molding die, first, the pressure medium path 14 of the pressure medium injection section 5 is heated to a temperature near the melting temperature of the raw material resin 12.
Next, during or after filling the raw material resin 12 into the cavity 4, a heated pressure medium is injected from the gas chamber 3 to form the blind cavity 11 in the raw material resin 12. At this time,
Since the pressure medium is injected in the direction from the back surface forming wall portion 1 a to the recess standing wall 2 a (back surface forming wall portion) of the movable mold, the opening of the blind cavity 11 is formed on the back surface of the resin molded body (raw material resin) 12. 15 will be formed. In addition, the movable mold 2 is displaced in the injection direction during injection of the pressure medium, and promotes formation of the blind cavity 11. After injecting a pressure medium and forming the desired blind cavity 11 in the raw resin 12, the raw resin 12 is solidified (cooled).
Then, the resin molded body 12 is obtained by releasing from the molding die. The filling amount of the raw material resin 12 can be set in consideration of the total volume of the resin molded product (sheet-like porous resin molded product) to be obtained and the total volume of the blind cavity 11.
It is effective to mold the resin molded body as described above because the resin molded body having the blind cavity can be molded in one step.

In the above molding method, the fluidity of the raw material resin 12 can be increased by using a heating device, and in this case, the blind cavity 11 can be formed more freely.
Further, a mold having a structure other than the above mold can be used as long as a desired resin molded body can be obtained. A mold using an injection molding method, a pressurized gas compression molding method, or the like is more preferable. Furthermore, in the above molding die, the diameter of the pressure medium flow path,
The shape and volume of the blind cavity can be controlled by appropriately changing / combining the protrusion of the pressure medium injection part, the gas chamber, the pressure medium storage chamber, the tip shape, the arrangement position, and the gas pressure of the pressure medium injection part. The shape of 11 may be a circle, an ellipse, a polygon, or the like (FIG. 2). The pressure medium injection unit 5
The arrangement interval and the existence ratio of the (pressure medium ejection ports) are partially biased so that the openings 15 of the blind cavities can be uniformly distributed on the back surface of the resin molded body, or densely distributed on a part of the back surface. For example, they can be distributed non-uniformly according to the desired sound absorption / sound insulation, partial rigidity, and lightness. Furthermore,
The thickness of the resin surrounded by the blind cavities 11, that is, the resin corresponding to the reinforcing ribs (the resin thickness between adjacent blind cavities) can be controlled by adjusting the position and density of the blind cavities. This makes it possible to adjust sink marks, warpage, and variations in rigidity of the obtained sheet-like molded body.

Next, in the present invention, a sound absorbing / insulating structure is formed by filling and / or covering a sound absorbing material in a blind cavity of the resin molded body. Thereby, the sound absorbing and sound insulating structure can exhibit more excellent sound absorbing characteristics. The sound absorbing performance can be improved by adjusting the density, type, amount, and composition of the sound absorbing material to be filled and / or coated.

The sound absorption characteristics are defined by the resonance of the air mass from the neck of the blind cavity, that is, the opening to the deepest portion of the surface layer depth t (FIG. 5), and the air spring component inside the blind cavity. Absorption of vertical, oblique, and random incident sounds by utilizing the phenomenon is referred to as "resonance sound absorption mechanism" formed in the sound absorbing / insulating structure.
Here, for example, in the sound-absorbing / insulating structure, the whole spring when the sound-absorbing fiber is used as the sound-absorbing material is not uniquely determined only by the fiber spring, but is also affected by the air spring. This air spring has a higher spring constant because the more the airflow resistance, the more difficult it is for air to move through the sound absorbing material. As a result, the sound absorbing performance of the sound absorbing / sound insulating structure tends to deteriorate.

Therefore, as the sound absorbing material, it is preferable to use organic fibers, inorganic fibers, foams and foam materials as described above. When a foam or a foam material is used, a foam having a foaming ratio of about 10 to 50 times or a foaming ratio of 10 to 50 times is used.
It is desirable to use a foam material of about 50 times. With these sound absorbing materials, the overall spring of the sound absorbing material becomes too large,
This is effective because the sound insulation performance can be prevented from lowering.

The sound absorbing / sound insulating structure according to the present invention,
In the method for manufacturing a sound-absorbing / insulating structure in which the sound absorbing material is filled in the blind cavity, the inside of the blind cavity is depressurized and the sound absorbing material is filled. In another manufacturing method of the present invention, a sound absorbing material is pressurized and filled into the blind cavity to manufacture an upper air absorbing / sound insulating structure. For example, a method of filling using an apparatus as shown in FIGS. 6 and 7 can be mentioned. 8 and 9 show examples of blind cavities filled with a sound absorbing material by these filling methods. The sound absorbing material can be filled by combining these filling methods.

FIG. 6 shows the suction port 18 and the sound absorbing material filling port 16.
6 shows a method of filling a sound absorbing material using a filling device 19 having a. First, the suction port 18 faces the surface of the resin molded body where the opening 15 is present, and the suction port 18 and the opening 15 are brought into close contact with each other and communicate with each other. Next, the inside of the blind cavity 11 is depressurized by sucking the air in the blind cavity 11 from the suction port 18. Thereafter, the filling device 19 is moved in the direction of the arrow (left).
To make the sound absorbing material filling port 1 closely contact and communicate with the opening 15.
The sound absorbing material 16 is filled into the blind cavity 11 from 6a. At this time, since the inside of the blind cavity 11 is decompressed, the sound absorbing material 16 is sucked into the blind cavity 11 and can be quickly filled. When the molding die shown in FIGS. 1 and 2 is used, the suction port 18 can be used together with the pressure medium injection unit 5.

FIG. 7 shows a method of filling the interior of the blind cavity with the sound absorbing material 16 under pressure using the press fitting device 20. When this device is used, it is preferable to provide a gap between the sound absorbing material filling port 16a and the opening 15 to allow air inside the blind cavity to escape during pressure filling.

Next, the sound absorbing and sound insulating structure of the present invention includes:
As shown in FIG. 8 or FIG. 9, a sound absorbing / insulating structure in which the opening existing surface is covered with a sound absorbing material 16 can be exemplified. In these sound absorbing / sound insulating structures, it is preferable that the sound absorbing material 16 is bonded or fused to the opening existing surface.
Examples of the method of bonding or fusing include a coating method, a hot stamping method, and a vibration fusing method. Also, an epoxy-based, acrylic-based, cyanoacrylate-based adhesive, or the like can be used as the adhesive, or the sound absorbing material itself can be fused. Further, it is sufficient that the sound absorbing material 16 is covered at least in the opening 15, but it is desirable to appropriately change the thickness and amount of the coating according to the resonance sound absorbing mechanism desired to be exhibited in the sound absorbing and sound insulating structure.

The sound absorbing / sound insulating structure shown in FIG. 8 is formed by covering the entire surface where the opening exists with a sound absorbing material 16.
Further, as shown in FIG. 9, a sound absorbing material 16 is coated on the blind cavity 11, and an air layer 17 (hollow portion) is provided between the coated sound absorbing material 16 and the surface where the opening 15 exists. -It can be a sound insulation structure. In such a sound absorbing and sound insulating structure, the size and shape of the air layer 17 can be changed at any time, and in particular, as in the sound absorbing and sound insulating structure shown in FIG. Is desirable. By providing the air layer 17, the sound absorption coefficient can be improved. In addition, it is also possible to impart strength to the sound absorbing material itself by dividing the sound absorbing material into blind cavities. When the sound absorbing material is covered, the blind cavity may or may not be filled with the sound absorbing material, but it is particularly preferable that the blind cavity is filled with the sound absorbing material. Can be improved. In addition, when filling the inside of the blind cavity with the sound absorbing material, and covering the sound absorbing material on the opening existing surface, the sound absorbing material used is not limited to the same type,
Different types may be used. Further, the sound absorbing material can be changed for each blind cavity.

The sound-absorbing and sound-insulating structure according to the present invention is 100
It is preferred to have the Hz~10kHz resonance sound absorption peak frequency _{f r.} If it is less than 100 Hz, the volume of the blind cavity becomes large, and it becomes difficult to mold the resin molded article into a sheet shape, and if it exceeds 10 kHz, other methods using a large amount of fiber-made sound absorbing material may be effective. . It is needless to say that when the blind cavity is provided with a bias as described above, the sound absorbing and sound insulating characteristics of the sound absorbing and sound insulating structure partially appear.

Further, the intake and sound insulation structure of the present invention, resonance as sound absorption peak frequency _{f r} is 100 Hz to 10 kHz, the sound speed, aperture diameter, aperture center point distance, depth and the surface layer portion of the blind cavity It is preferable to set the depth. In this case, it is effective because a sound absorbing and sound insulating structure having a desired resonance sound absorbing frequency can be obtained. Specifically, it is preferable that the above-mentioned sound absorbing / sound insulating structure satisfies the relationship represented by the following expression (1). Any sound-absorbing and sound-insulating structure made of a resin molded body satisfying the formula (1) can have excellent sound-absorbing characteristics.

[0035]

(Equation 3)

[0036] Here, _{f r} in the formula is the resonance sound absorption peak frequency [Hz], c is sound velocity [m / s], d is the aperture diameter [mm], D the distance between the above aperture center point [ mm],
L is the depth of the blind cavity [mm] and t is the surface layer depth [m
m]. As shown in FIGS. 4 and 5, the surface layer thickness t refers to the distance between the shoulder where the opening of the blind cavity is enlarged and the surface of the molded body, and the distance D between the opening center points is defined as: It refers to the distance between the center points of the openings between adjacent blind cavities. X is the thickness of the resin molded body.

[0037]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in more detail with reference to the drawings by way of examples and comparative examples, but the present invention is not limited to these examples.

The resin moldings used in Examples and Comparative Examples were molded by the following molding die and molding method. (1) Mold for Molding Resin Mold A mold having the structure shown in FIG. 1, and a fixed mold 1 is provided with a gas injection nozzle having a heating mechanism. The internal volume of the gas chamber was about 3 cm ³ . The volume in the cavity is 1
It could be displaced in the range of 00 × 100 × 3 (before variable) to 10 (after variable) mm. Nozzle for pressurized gas injection is φ6mm
A gas outlet having an inner diameter of 50 μm and no check valve was used (Fig. 3), and about 12 nozzles were arranged at equal intervals of 5 mm in the center of the opening forming surface (back surface) forming wall. did. Flat nozzles were used for the tips of the nozzles.

(2) Method of Forming Resin Molded Body The above-mentioned molding die was set in an injection molding machine having a mold clamping pressure of 110 t. A polystyrene resin (trade name: G120K, manufactured by Nippon Polystyrene Co., Ltd.) melted into the cavity from the resin injection portion of the fixed mold was injection-molded at a resin temperature of 200 ° C. The mold temperature was 60 ° C., the resin was filled in the cavity, the thickness of the cavity was increased from 3 mm to 6 mm, molded, cooled, and taken out to obtain a resin molded body. In addition, the gas uses heated compressed air, and is used at the inlet of the gas supply system.
0 ° C.

Example 1 The thickness X of the resin molded product was 6 mm,
A resin molded body having blind cavities with an opening diameter d of 3 mm and a hole depth L of 3 mm was molded, and PET fibers 3 were placed in each blind cavity.
A sound absorbing / sound insulating structure filled with 00 g / m ³ (3 denier) was manufactured. Table 1 shows the conditions of the sound absorbing mechanism of this sound absorbing and sound insulating structure and whether or not it can be formed.

(Example 2) The thickness X of the resin molded product was 6 mm,
A resin molded body having blind cavities with an opening diameter d of 3 mm and a hole depth L of 3 mm was molded, and a 300 g / m ³ (3 denier) · 10 t PET fiber was coated on the surface where each blind cavity had an opening.・ The sound insulation structure was manufactured. Table 1 shows the conditions of the sound absorbing mechanism of this sound absorbing and sound insulating structure and whether or not it can be formed.

Example 3 When the thickness X of the resin molded product was 6 mm,
A resin molded body having blind cavities with an opening diameter d of 3 mm and a hole depth L of 3 mm was molded, and PET fibers 3 were placed in each blind cavity.
Packed 200 g ^{/ m} 3 (the 3 denier), was prepared intake and sound insulation structure coated with PET fibers 300 g ^{/ m} 3 (3 denier), 10t in the opening existing surface (Figure 8). Table 1 shows the conditions of the sound absorbing mechanism of this sound absorbing and sound insulating structure and whether or not it can be formed.

Example 4 The thickness X of the resin molded product was 6 mm,
A resin molded body having blind cavities with an opening diameter d of 3 mm and a hole depth L of 3 mm was molded, and PET fibers 3 were placed in each blind cavity.
200 g ^{/ m} 3 was filled with (3 denier), opening existing surface on PET fiber 300 g ^{/ m} 3 (3 denier) · 10t openings blind cavity and 5mm air layer between the PET fibers (hollow portion) (FIG. 9). Table 1 shows the conditions of the sound absorbing mechanism of this sound absorbing and sound insulating structure and whether or not it can be formed.

(Example 5) The thickness X of the resin molded product was 6 mm,
A resin molded body having blind cavities with an opening diameter d of 3 mm and a hole depth L of 3 mm was molded, and each blind cavity had a foaming ratio of 3
A urethane foam of communicating cells was filled at 0 times, and a 10-t urethane foam was also coated on the surface where the opening existed to produce a sound absorbing / sound insulating structure. Table 1 shows the conditions of the sound absorbing mechanism of this sound absorbing and sound insulating structure and whether or not it can be formed.

Comparative Example 1 A sheet-like resin molded product was obtained by repeating the same operation as in Example 1 except that no blind cavity was provided and the sound absorbing material was not covered. Table 1 shows whether or not the resin molded body can be molded.

(Comparative Example 2) A resin molded body was obtained by repeating the same operation as in Example 1 except that the sound absorbing material was not filled and covered. Table 1 shows the conditions of the sound absorbing mechanism of this resin molded body and whether or not it can be molded.

(3) Evaluation The normal sound absorption coefficient and the presence / absence of sink marks were evaluated for the sound absorbing and sound insulating structures and the resin moldings obtained in Examples 1 to 5 and Comparative Examples 1 and 2. Normal incidence sound absorption coefficient Measured according to JIS A 1405. The results are shown in Table 2 and a graph (FIG. 10). The presence or absence of sink marks was evaluated by visually observing the appearance of the 12 sound-absorbing and sound-insulating structures and the 12 resin moldings.

[0048]

[Table 1]

[0049]

[Table 2]

As shown in Table 2 and the graph (FIG. 10),
It is understood that within the range of the present invention, the sound absorbing performance of the sound absorbing / sound insulating structure can be improved, and the sound absorbing performance can be provided in accordance with a desired frequency band. On the other hand, in the comparative example, since the resin molded body having a configuration outside the scope of the present invention was used, no sound absorbing performance was obtained (Comparative Example 1), and even when the sound absorbing performance was obtained, the sound absorbing performance was lower than that of the example. It turns out that it falls remarkably (comparative example 2).

[0051]

As described above, according to the present invention, the sound-absorbing material is filled in the blind cavity provided in the resin molded body and / or
Or a method of manufacturing a sound-absorbing and sound-insulating structure that has high sound-absorbing characteristics in a wide frequency range, is lightweight and has good rigidity, and a sound-absorbing and sound-insulating structure that can be controlled to have sound absorbing characteristics. Can be provided.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing an example of a mold for molding a resin molded body (before resin injection).

FIG. 2 is a side sectional view showing an example of a mold for molding a resin molded body (after resin injection).

FIG. 3 is a side sectional view showing an example of a pressure medium injection unit.

FIG. 4 is a plan view showing an opening present surface of a resin molded product (blind cavity).

FIG. 5 is a cross-sectional view taken along line AA showing a shape of a blind cavity of the resin molded product shown in FIG.

FIG. 6 is a side sectional view showing an example of a device for filling the sound absorbing material by reducing the pressure inside the blind cavity.

FIG. 7 is a side sectional view showing an example of an apparatus for pressurizing and filling a sound absorbing material into a blind cavity.

FIG. 8 is a side sectional view showing an example of a sound absorbing and sound insulating structure filled and covered with a sound absorbing material.

FIG. 9 is a side sectional view showing an example of a sound absorbing / sound insulating structure (with an air layer) filled and covered with a sound absorbing material.

FIG. 10 is a graph showing sound absorption coefficient measurement results.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fixed mold 1a Back molding wall 2 Movable mold 2a Surface molding wall 3 Gas chamber 4 Cavity 5 Pressure medium injection part (nozzle for pressurized gas injection) 6 Resin injection port 7 Gas cylinder 8 Pressure control valve 9 Control valve 10 Heating device 11 Blind cavity 12 Resin molded body 13 Gas outlet 14 Gas path 15 Blind cavity opening 16 Sound absorbing material 16a Sound absorbing material filling port 17 Air layer (hollow portion) 18 Suction port 19 Filling device 20 Press-in device

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Noriyoshi Torii 2 Takara-cho, Kanagawa-ku, Yokohama-shi, Kanagawa Prefecture Nissan Motor Co., Ltd. (72) Inventor Koichi Handa 2 Takara-cho 2 Kanagawa-ku, Yokohama-shi, Kanagawa Nissan Motor Co., Ltd. Terms (reference) 2E001 DF02 DF04 GA07 GA20 GA28 GA82 HA31 HD01 HD03 HD11 HD14 JA07 JA22 JA29 JB01 JC08 JD04 LA04 3D023 BA02 BA03 BB01 BB21 BB30 BC01 BE20 5D061 AA06 AA11 AA22 AA26 BB02 BB21 DD11

Claims (8)

[Claims] 1. A sound-absorbing and sound-insulating structure comprising: a resin molded body having a plurality of independent blind cavities having openings on a front surface or a back surface; and a sound-absorbing material. A sound absorbing / sound insulating structure characterized by being filled and / or coated on a substrate. 2. A 100Hz~10kHz have a resonant sound absorption peak frequency _{(f r),} characterized in claim 1 intake and sound insulation structure according. 3. The following equation (1): _{(F r} is the resonant sound absorption peak frequency in the formula [Hz], c
Is the sound speed [m / s], d is the opening diameter [mm], D is the distance between the opening center points [mm], L is the depth of the blind cavity [mm], and t is the surface layer depth [mm]. The sound absorbing and sound insulating structure according to claim 1 or 2, wherein a relationship represented by the following formula is satisfied. 4. The sound absorbing material according to claim 1, wherein the sound absorbing material is an organic fiber and / or an inorganic fiber.
The sound-absorbing and sound-insulating structures described in the two items. 5. The sound absorbing and sound insulating structure according to claim 1, wherein the sound absorbing material is a foam and / or a foam. 6. The sound absorbing material according to claim 1, wherein said blind cavity is covered with said sound absorbing material, and an air layer is provided between said covered sound absorbing material and a surface where said opening exists. The sound absorbing / sound insulating structure according to any one of the above items. 7. The sound-absorbing and sound-insulating structure according to any one of claims 1 to 6, wherein the sound-absorbing material is filled in the blind cavity, and the blind and sound-insulating structure is manufactured. A method for producing a sound-absorbing and sound-insulating structure, comprising reducing the pressure inside a cavity and filling the sound-absorbing material. 8. The sound-absorbing and sound-insulating structure according to any one of claims 1 to 6, wherein the blind and sound-insulating structure in which the sound-absorbing material is filled in the blind cavity is provided. A method for producing a sound-absorbing and sound-insulating structure, characterized by filling the inside of a cavity with the above-mentioned sound-absorbing material under pressure.