JP3488335B2 - Manufacturing method of soundproof structure - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for manufacturing a soundproof structure.
For more information on the law , instrument panel of the car,
The present invention relates to a method for manufacturing a soundproof structure capable of preventing noise in the engine room and noise outside the vehicle from entering the vehicle interior by using it for an interior product having a cushioning property such as a door trim.

[0002]

2. Description of the Related Art For example, as shown in FIG. 7, an instrument panel of an automobile has a plate-like base material 300 made of ABS resin, a skin 301 made of polyvinyl chloride or the like, a skin 301 and a base. It is composed of a foam material 302 such as polyurethane formed between the material 300 and the material. The base material 300 gives rigidity, and the foam 302 and the skin 301 give good tactile sensation and appearance.

In recent years, a sound absorbing member 303 such as felt or slab urethane is joined to the back surface of the base material 300 to prevent noise from the engine room or the like from entering the vehicle interior by the sound absorbing member 303. Has also been done. That is, by providing such a porous sound absorbing member 303, the sound waves that have reached the sound absorbing member 303 are scattered, and the sound energy is converted into thermal energy in the numerous holes on the surface of the sound absorbing member 303. Sound waves decay or disappear.

To manufacture such an instrument panel, first, a base material 300 having a predetermined shape is formed by injection molding or compression molding, and a skin 301 having a predetermined shape is formed by vacuum molding or the like. Next, the base material 300 and the skin 30
1 is placed in a molding die, and a foam resin is injected between the base material 300 and the skin 301 to perform foam molding. The skin 301 is pressed against the mold surface by the foaming pressure of the foamed resin to be shaped, and the foam 302 having a predetermined shape is integrally bonded to the skin 301 and the base material 300.

After the mold is released from the mold, an extra skin is trimmed and a sheet-shaped sound absorbing member 303 is joined to the back side of the base material 300 with a double-sided tape or an adhesive.

[0006]

As described above, the sound absorbing member 303 is formed by adhering it after forming the instrument panel. Therefore, the sound absorbing member 303
The step of adhering the sound absorbing member 303 is required as compared with the case of manufacturing an instrument panel having no sound. However, the instrument panel is a large molded product,
Also, positioning the bonding position is not easy, so
The positioning accuracy is not stable and the number of bonding steps is large.

Further, the substrate 30 of the instrument panel
On the back side of 0, protrusions 3 such as mounting bosses and reinforcing ribs
Since a large number of 04 are projected, the sound absorbing member 303 has projections 3
It is necessary to provide notches and through holes for avoiding interference with 04 and to bond them, and the number of steps is further increased. In addition, there is a problem that it is difficult to bond the sound absorbing member 303 to some parts, and a sufficient soundproof effect cannot be obtained.

The present invention has been made in view of such circumstances, and the number of steps is reduced by integrally forming a sound absorbing member at the time of forming a foam or forming a sound absorbing layer at the same time of forming a foam. At the same time, the purpose is to further improve the soundproofing characteristics.

[0009]

The method of manufacturing a soundproof structure according to claim 1 for solving the above-mentioned problems is characterized in that
Place the sound absorbing member on the mold surface of the split mold and
Arrange a plate-shaped substrate with through holes that penetrate the front and back on the surface,
And an arranging step of arranging the epidermis on the mold surface of the other split mold,
The split mold is closed and a resin foam is injected between the base material and the skin.
Molding work to form a foam layer that integrally joins the material and the skin
The foamed resin is formed by foaming through the through holes.
Intrudes between the material and the sound absorbing member, and the sound absorbing member is integrated with the base material.
It is to form an adhesive layer to be bonded to. This manufacturing method
The soundproof structure obtained by means of the following is a plate-shaped base material having through holes penetrating the front and back, a foam body integrally formed on the surface of the base material, and a skin laminated integrally on the surface of the foam body. Layers and
A sound absorbing member disposed on at least a part of the back surface side of the base material, and an adhesive layer that is interposed between the sound absorbing member and the base material and integrally joins the sound absorbing member and the base material, and is bonded to the foam. The layer is an integral foam body integrated through a through hole .

[0010]

[0011]

Further , the manufacture of the soundproof structure according to claim 2.
The feature of the method is that a plate-shaped base material having through holes penetrating the front and back is arranged so as to cover the sub-cavity formed on the mold surface of one split mold, and a skin is arranged on the mold surface of the other split mold. And a molding step of closing the split mold and injecting a foam resin between the base material and the skin to form a foam that integrally joins the base material and the skin, and the foam resin penetrates by foaming. The purpose is to fill the sub-cavity through the holes and form a sound absorbing layer that holds the base material together with the foam. This manufacturing
The soundproof structure obtained by the method has a penetration that penetrates the front and back.
A plate-shaped base material with holes and is integrally formed on the surface of the base material.
Foam and a skin that is integrally laminated to the surface of the foam
And a sound absorbing layer formed on at least a part of the back surface side of the base material
The foam and sound absorbing layer are integrated through the through hole.
It is an integrated foam.

[0013]

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION In the soundproof structure obtained by the present invention, the presence of the sound absorbing member and the sound absorbing layer prevents the noise transmitted to the surface side where the sound absorbing member and the sound absorbing layer are present from transmitting to the skin side . The sound absorbing member is integrally joined to the back surface side of the base material by the adhesive layer. Further, the adhesive layer is formed by the foamed resin penetrating between the base material and the sound absorbing member on the back surface side of the base material through the through hole during the formation of the foamed body.

That is, the adhesive layer is a foam integrated with the foam, and the adhesive layer itself has a sound absorbing property. Further, even if there are bosses and ribs on the back surface of the base material and it is difficult to provide the sound absorbing member, only the adhesive layer can be sufficiently formed. Therefore, the sound absorbing characteristics are improved as compared with the conventional one in which the sound absorbing member is joined with a double-sided tape or the like. In the manufacturing method according to the first aspect of the present invention for manufacturing the soundproof structure, the base material, the skin and the sound absorbing member are arranged in the mold to integrally form the foam. That is, the foamed resin penetrates between the base material and the sound absorbing member through the through hole of the base material to form an adhesive layer to bond the sound absorbing member to the base material.

Therefore, according to this manufacturing method, the step of joining the sound absorbing member in the conventional subsequent step can be omitted, and the number of steps can be reduced. As the foam, polyurethane is generally used as in the conventional case. The foaming density can be appropriately selected according to the desired tactile sensation. The skin is not particularly limited, such as polyvinyl chloride and woven cloth. Further, as the sound absorbing member, the same material as the conventional one such as felt or slab urethane can be used. The sound absorbing member may be arranged on the entire back surface of the base material or may be arranged partially.

And in the manufacturing method according to claim 2 ,
The foamed resin is spread by foaming to the back side of the substrate through the through hole.
To form a sound absorbing layer that holds the base material together with the foam.
It In the resulting soundproofing structure, the sound absorbing layer and the foam are integrated foams that are integrated through the through holes, and may be the same material or different materials. It is desirable to form at least the sound absorbing layer from a soft foam having excellent sound absorbing properties.

That is, since the sound absorbing layer is formed by molding at the time of forming the foam, the step of joining a sound absorbing member such as felt unlike the conventional case is unnecessary. Further, even if there are bosses or ribs on the back surface side of the base material, the sound absorbing layer can be formed freely at a desired position and with a free thickness. Further, since the mold surface shape is transferred to the surface of the sound absorbing layer, the surface can be freely formed into a shape suitable for sound absorption, and the sound absorbing characteristics can be further improved.

As the foam, polyurethane is generally used as in the conventional case. The foaming density can be appropriately selected according to the desired tactile sensation. The skin is not particularly limited, such as polyvinyl chloride and woven cloth.

Therefore, in this soundproof instrument panel, the number of steps for joining a sound absorbing member such as felt after manufacturing the instrument panel as in the conventional case is not required, and the cost can be reduced. The sound absorbing layer absorbs noise from the engine room, so that the noise is prevented from entering the vehicle interior.

[0021]

EXAMPLES The present invention will be specifically described below with reference to examples. (Embodiment 1) FIG. 1 is a sectional view of a soundproof instrument panel manufactured by the manufacturing method of this embodiment. This soundproof instrument panel comprises a plate-shaped base material 1 made of ABS resin, a polyurethane foam 2 formed on the front surface side of the base material 1, and a poly-carbon resin integrally coated on the surface of the foam 2. The skin 3 made of vinyl chloride, the adhesive layer 4 made of polyurethane formed on the back surface side of the base material 1, and the base material 1 via the adhesive layer 4.
The sound absorbing member 5 made of felt and joined to the.

A plurality of through-holes 10 penetrating the front and back are formed in the base material 1, and the adhesive layer 4 and the foam 2 are integrally connected through the through-holes 10. Hereinafter, the manufacturing method will be described to replace the detailed description of the structure of the soundproof instrument panel. First, the base material 1 having a predetermined shape is formed by injection molding. On the other hand, the skin 3 is formed by vacuum forming. Further, the felt is cut into a predetermined shape to form the sound absorbing member 5.

Next, a mold as shown in FIG. 2 is prepared, the outer skin 3 is placed on the mold surface of the lower mold 100, and the upper mold 20.
The sound absorbing member 5 and the base material 1 are arranged on the mold surface of 0. Then, a predetermined amount of the foamed resin 20 is injected into the concave skin 3, and the upper mold 20
0 is rocked and clamped with the lower mold 100. Foam resin 20
When the foam expands and the volume expands, the foamed resin 20 enters from the through hole 10 of the base material 1 and enters between the sound absorbing member 5 and the base material 1 to bond the sound absorbing member 5 to the base material 1. Is formed. The foamed resin 20 presses the skin 3 against the mold surface of the lower mold 200 to shape it into a predetermined shape.

As a result, the foam body 2 integrally formed with the base material 1 and the surface skin 3 is formed, and the excess surface skin 3 is trimmed after the mold release. Therefore, according to the manufacturing method of the present embodiment, since the sound absorbing member 5 is joined to the base material 1 at the same time when the foam 2 is molded by the adhesive layer 4, the step of adhering the sound absorbing member 5 in a later step can be omitted, and the number of steps Can be greatly reduced.

Further, in the obtained instrument panel, the adhesive layer 4 also has a sound absorbing property because it is a porous body. Therefore, noise is absorbed by both the sound absorbing member 5 and the adhesive layer 4, and the sound absorbing characteristics are improved. Moreover, even in a place where it is difficult to provide the sound absorbing member 5 due to the presence of the boss and the rib,
By properly forming the through holes 10, the adhesive layer 4 having sound absorbing characteristics can be formed. Therefore, the sound absorption characteristics are further improved as compared with the conventional case.

(Embodiment 2) FIG. 3 shows a cross-sectional view of a main part of a soundproof instrument panel formed in this embodiment. This soundproof instrument panel comprises a plate-shaped base material 1 made of ABS resin, a polyurethane foam 2 formed on the front surface side of the base material 1, and a poly-carbon resin integrally coated on the surface of the foam 2. It is composed of a vinyl chloride skin 3 and a polyurethane sound absorbing layer 51 formed on the back surface side of the substrate 1.

The foam 2 and the sound absorbing layer 51 are made of the same material and are connected to each other through the through hole 10. Further, conical peaks 52 and valleys 53 are alternately formed in a checkered pattern on the surface of the sound absorbing layer 51, whereby the sound absorbing characteristics are enhanced. This soundproof instrument panel was manufactured as shown in FIG. First, the base material 1 having a predetermined shape is formed by injection molding. On the other hand, the skin 3 is formed by vacuum forming. Next, the skin 3 is placed on the die surface of the lower die 100, and the base material 1 is placed on the die surface of the upper die 200. At this time, between the die surface of the upper die 200 and the base material 1, a sub-cavity 201 is formed which is in communication with the main cavity via the through hole 10 and has an irregular shape on the die surface. Then, a predetermined amount of the foamed resin 20 is injected into the concave skin 3, and the upper mold 200 is swung to clamp the lower mold 100.

When the foamed resin 20 foams and expands in volume, the foamed resin 20 fills the inside of the sub-cavity 201 from the through hole 10 of the substrate 1 to form the sound absorbing layer 51. The foamed resin 20 presses the skin 3 against the mold surface of the lower mold 200 to shape it into a predetermined shape. That is, in this embodiment, since the sound absorbing layer 51 is formed at the same time as the foamed body 2, the step of adhering the sound absorbing member in a later step as in the conventional case is unnecessary. Further, as shown in FIG. 3, even if the boss 11 or the like exists on the base material 1, the through hole 1
By properly providing 0, the sound absorbing layer 51 can be freely formed at a predetermined position of the base material 1. Furthermore, the sound absorbing layer 5
Since 1 is formed by molding, its surface shape can be freely designed, and the sound absorbing characteristics can be easily enhanced.

(Embodiment 3) This embodiment is the same as Embodiment 2 except that the surface shape of the sound absorbing layer 51 is different as shown in FIG. That is, on the surface of the sound absorbing layer 51, a large number of holes 54 having a narrow inlet and a large inside are formed. The holes 54 have high sound absorption characteristics based on Helmholtz's resonance theory, and further prevent noise from entering the vehicle interior. By designing the shape of the holes 54 as desired, the frequency of sound that can be absorbed can be set as desired.

In order to form the holes 54, convex portions are formed on the mold surface of the sub-cavity 201, and the convex portions and the holes 54 are undercut. However, since the sound absorbing layer 51 is a foam, it can be easily deformed and easily released from the mold. (Embodiment 4) In this embodiment, as shown in FIG.
Example 2 except that a grain 55 is formed on the surface of
It has the same configuration as. Even if the grain 55 is formed in this way, high sound absorption characteristics can be obtained.

[0031]

That is, the method of manufacturing the soundproof structure of the present invention
According to the method, the step of adhering the sound absorbing member in the subsequent step is unnecessary.
Therefore, the man-hours can be greatly reduced and the cost is low.
Can be reduced. And by the obtained soundproof structure
In this case , the sound absorbing layer can be provided at an arbitrary position on the back surface of the base material regardless of the presence of the boss and the rib, so that the soundproof performance is improved.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of essential parts of a soundproof instrument panel obtained in an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a molding die used in one embodiment of the present invention when injecting a foamed resin.

FIG. 3 is a cross-sectional view of essential parts of a soundproof instrument panel obtained in a second embodiment of the present invention.

FIG. 4 is a cross-sectional view showing a molding die used in a second embodiment of the present invention when injecting a foamed resin.

FIG. 5 is a cross-sectional view of essential parts of a soundproof instrument panel obtained in a third embodiment of the present invention.

FIG. 6 is a cross-sectional view of essential parts of a soundproof instrument panel obtained in a fourth embodiment of the present invention.

FIG. 7 is a sectional view of a conventional soundproof instrument panel.

[Explanation of symbols]

1: Substrate 2: Foam 3:
Skin 4: Adhesive layer 5: Sound absorbing member 10:
Through hole 11: Protrusion 20: Foam resin 5
1: Sound absorption layer

Continuation of front page (56) References JP-A-5-200921 (JP, A) JP-A-61-69416 (JP, A) Actual development Shou-53-36301 (JP, U) (58) Fields investigated (Int .Cl. ⁷ , DB name) G10K 11/172 B32B 5/32

Claims (2)

(57) [Claims] 1. A sound absorbing member is arranged on the mold surface of one of the split molds, and a plate-shaped substrate having through holes penetrating through the front and back is arranged on the surface of the sound absorbing member, and the mold face of the other split mold. An arranging step of arranging a skin on the base, and a molding step of closing the split mold to inject a foaming resin between the base material and the epidermis to form a foam layer for integrally bonding the base material and the epidermis. The foamed resin infiltrates between the base material and the sound absorbing member through the through hole by foaming to form an adhesive layer that integrally joins the sound absorbing member to the base material. And a method for manufacturing a soundproof structure. 2. A plate-shaped base material having through-holes penetrating the front and back so as to cover a sub-cavity formed on the mold surface of one split mold, and a skin is arranged on the mold surface of the other split mold. And a molding step of closing the split mold and injecting a foaming resin between the base material and the skin to form a foam that integrally joins the base material and the skin. A method of manufacturing a soundproofing structure, wherein foamed resin fills the sub-cavity through the through-hole by foaming to form a sound absorbing layer that sandwiches the base material together with the foamed body.