JPH08155976A - Seal structure of skin side surface part in integral foam molding - Google Patents

Abstract

PURPOSE: To provide the seal structure of a skin side surface part capable of efficiently preventing the leakage of foam from the skin side surface part when the foam is integrally molded along with a skin and a core to obtain a plastic molded product fitted with a pad having good appearance and quality. CONSTITUTION: A skin 21 is arranged to a pad housing part 13 entirely or partially surrounded by the side wall 12 formed to a core 11 so that the side surface part 22 of the skin 21 almost comes into contact with the side wall of the pad housing part 13 and a foamable raw material P is foamed within the pad housing part to perform integral foam molding. In this foam molding, an elastic seal material 25 is provided to the skin side surface part 22 being in contact with the side wall of the pad housing part 13 and, at the time of foaming, the skin side surface part 22 is bonded to the side wall of the pad housing part 13 under pressure through a elastic seal material 25.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a skin side surface seal structure in integral foam molding.

[0002]

2. Description of the Related Art A plastic molded product with a pad having a pad having a skin adhered to the surface of a foam on the surface of the core is used in various fields such as interior parts of automobiles or furniture. For example, in the instrument panel of the automobile, as shown in FIG. 5, the pad 42 is partially provided on the surface of the core 41, or the pad is provided on the entire surface of the core, as shown in FIG. The one provided is used.

In recent years, an integrated foam molding method has been proposed as a simple method for producing the above-mentioned plastic molded product with a pad, in which the foam of the pad is molded and the foam is integrated with the skin and the core. As shown in FIG. 6, the integral foam molding method uses a sidewall 5 formed on a predetermined portion.
Pad accommodating portion 52 which is entirely or partially surrounded by 1.
While disposing the core 53 including the core 53 on the upper mold 61, the outer mold 72 having the side surface portion 71 formed on the edge thereof is disposed on the lower mold 6 so that the side surface portion 71 substantially contacts the side wall 51 of the pad accommodating portion 52.
2, the foaming raw material P such as polyurethane is foamed between the inner surface of the pad accommodating portion 52 and the skin 72, and the foamed product is integrated with the core 53 and the skin 72.

In this integral foam molding method, as shown in FIG. 7, the foaming raw material P fills the space between the core 53 and the skin 72 while generating a foaming gas as the foaming reaction proceeds.
Therefore, due to the increased pressure between the core 53 and the skin 72 due to the foaming gas, and the foam (foaming raw material) filled between the core 53 and the skin 72, the side surface portion 71 of the skin becomes a pad accommodating portion as indicated by a chain line. The foam is pressed against the side wall 51 and tightly sealed to prevent the foam from leaking from the side surface portion 71 of the skin. The foam is integrated with the skin and the core by the self-adhesiveness generated when the foaming raw material P is foamed.

However, in the integral foam molding method,
Since the tip of the side surface portion of the epidermis is the open end 73, the rigidity of the side surface portion 71 is low, and the side surface portion 71 of the epidermis is deformed by waviness or the like during storage of the epidermis or when the epidermis is placed in a mold. Is likely to occur. When the integral foam molding is performed using the deformed skin, as shown in FIG. 8, the side surface 71 of the skin 72 and the side wall 5 of the pad accommodating portion of the core 53 are formed.
A gap S is generated between the two to easily cause a seal defect. As a result, the foam (foaming raw material) leaks from the gap S and adheres to the surface of the skin 72, or the foam of the pad lacks due to defective filling due to the leak, resulting in appearance or quality of the molded product. There is a problem that causes a drop. In particular, as understood from FIG. 5, when the pad 42 is arranged on the surface of the core 41 (reference numeral 51 in FIG. 7), the foaming raw material is applied to the core 41 (51) or the skin of the pad 42 from the boundary portion 43. Leakage above (reference numeral 72 in FIG. 7) is a fatal decorative defect. Moreover, the deformation habit once attached to the side surface of the epidermis hardly returns even when the epidermis is heated, so that the above problem was not easily solved.

[0006]

SUMMARY OF THE INVENTION Therefore, the present invention
When the foam is integrally molded with the skin and core, it is possible to effectively prevent the foam from leaking from the side surface of the skin, and a padded plastic molded product with good appearance and quality can be obtained. Is to provide.

According to the present invention, the pad accommodating portion, which is entirely or partially surrounded by the side wall formed in the predetermined portion of the core,
The skin is arranged such that the side surface of the edge thereof is substantially in contact with the side wall of the pad accommodating portion, and in integral foam molding in which the foaming raw material is foamed in the pad accommodating portion, the skin side surface portion is in contact with the side wall of the pad accommodating portion. The present invention relates to a skin side surface sealing structure in integral foam molding, characterized in that an elastic seal material is provided and the skin side surface part is pressed against the side wall of the pad accommodating portion via the elastic seal material during the foaming.

[0008]

Since the side surface portion of the skin provided with the elastic seal material is reinforced by the elastic seal material, the side surface portion of the skin is less likely to be deformed such as corrugated when it is arranged on the mold surface of the split mold. Therefore, when the side surface of the skin is pressed against the side wall of the pad accommodating portion via the elastic seal material by the foam filled in the skin and the core and the foaming pressure thereof, the side surface of the skin does not have a gap via the elastic seal material. It adheres closely to the side wall of the pad housing, and seals the side surface of the skin well. Further, even if there is some deformation in the skin side surface portion, the elastic seal material elastically deforms and absorbs the deformation of the skin side surface portion. Can be closely adhered to and the side surface portion of the skin and the side wall of the pad accommodating portion can be well sealed.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is a cross-sectional view of a molding die when integrally molding a plastic molded product with a pad by using the seal structure of the present invention, FIG. 2 is an enlarged cross-sectional view of a main portion of the molding die showing the foaming process, and FIG. FIG. 4 is an enlarged cross-sectional view of a main part of a molding die showing a sealed state at the time of foaming, and FIG. 4 is a partial perspective view showing an example of a skin used in the present invention.

First, the core 11 and the skin 21 used in this embodiment will be described. The core 11 shown in FIG.
It is for molding a plastic molded product having a pad on the entire surface on one side, and has a pad accommodating portion 13 surrounded by a side wall 12. The material of the core 11 is made of a hard plastic such as ABS resin (acrylonitrile-butadiene-styrene resin), polypropylene, or a plastic having a high shape retention property such as a fiber reinforced plastic. Further, in the core 11 of this embodiment, an injection port 14 for injecting a liquid foaming raw material (closed injection) into the pad accommodating portion 13 with the molding die closed is provided with a pad accommodating portion 13.
Is formed so as to penetrate the inside and outside. The core 11
May have a pad accommodating portion in a part like the core shown in FIG. 6, and the side wall 12 does not enclose the entire periphery of the pad accommodating portion 13 but partially encloses it. Good. That is, the pad accommodating portion may be configured without providing the side wall in the portion that becomes the invisible portion.

The skin 21 is made of plastic leather or the like formed into a desired shape by vacuum molding or slush molding, and has a side surface portion 22 bent toward the back surface at the edge. The side surface portion 22 is the pad accommodating portion 13 of the core 11.
Is formed so as to fit in.

On the outer surface of the side surface portion 22 of the skin, as can be better understood from FIG. 4 showing a part of the skin 21 in an enlarged manner, a necessary portion of the side surface portion 22, that is, a pad accommodating portion of the core is formed. A string-shaped elastic seal member 25 is provided along the open end 23 of the side surface portion 22 by adhesion or the like at a portion in contact with the side wall 12. The elastic sealing material 25 enhances the rigidity of the skin side surface portion 22 and prevents the skin side surface portion 22 from being deformed such as waviness when the skin 21 is placed in the molding die and when the molding die is closed. When the liquid foaming raw material is foamed, it is interposed between the skin side surface portion 22 and the side wall 12 of the pad accommodating portion 13 of the core 11 for sealing. The material of the elastic sealing material 25 is made of a material having elasticity such as a soft foam such as polyurethane foam, a non-woven fabric, or a foam type hot melt resin. Further, it is preferable that the elastic sealing material 25 is provided near the open end 23 of the side surface portion 22 which is located far from the surface 24 of the skin 21. Then, the rigidity of the open end 23 of the outer skin side surface portion 22 is further enhanced, the sealing property is further enhanced, and the elastic sealing material 25 is not visible from the surface side of the outer skin 21, further improving the appearance of the molded product. be able to. As an example, an example in which a string-shaped polyurethane foam having a cross section of 2 mm × 2 mm is provided at a position 3 mm above the open end 23 of the skin side surface part 22 will be given. The elastic sealing material 25 is not limited to one as in this embodiment, but two or more elastic sealing materials 25 may be provided in parallel. By doing so, the rigidity of the skin side surface portion 22 is further increased, and the side surface portion 22
The effect of preventing deformation such as waviness can be further enhanced.

The core 11 is placed on the die surface of the upper die 31 of the die, while the skin 21 is placed on the die surface of the lower die 33 and the die is closed. At that time, the core 11 is attached to the mold surface of the upper mold 31 with the side wall 12 of the pad accommodating portion 13 facing the lower mold 33. The core 11 is attached by using a clip or the like (not shown) provided on the mold surface of the upper mold 31.
Further, the outer skin 21 faces the pad housing portion 13 of the core 11 on the lower mold 33 die surface, the back surface of the outer skin 21 faces the upper die 31 side, and the side surface portion 22 of the outer skin 21 is closed by the closing die. It is arranged so as to fit into the pad accommodating portion 13 of the core 11. In order to facilitate the positioning of the outer skin 21 at that time, it is preferable that a lower surface of the lower die 33 is provided with a step between the outer skin placement surface 34 and the surrounding die surface. Reference numeral 35 is a cavity formed between the upper mold 31 and the lower mold 33.

Due to the closed mold, the skin 21 has a side surface portion 22.
Is fitted into the pad accommodating portion 13 of the core 11, and the pad accommodating portion 13 is covered. At this time, the epidermis 21
The side surface portion 22 contacts the side wall 12 of the pad accommodating portion 13, or the open end 23 of the tip is slightly separated from the side wall 12. However, the side surface portion 22 of the skin 21
Since the rigidity is increased by the elastic sealing material 25,
Deformation such as waviness is unlikely to occur when the outer skin 21 is arranged and closed, and an irregular gap is not formed between the side surface portion 22 of the outer skin 21 and the side wall 12 of the pad accommodating portion 13.

Next, a liquid foaming raw material P such as a polyurethane raw material is injected from the injection nozzle N of the foaming device set in the nozzle injection part 36 of the upper die 31 between the core 11 and the skin 21 through the injection port 14 of the core. To do.

The injected foaming raw material P fills the pad accommodating portion 13 while initiating a foaming reaction to form a foam. When the foam (liquid foaming raw material P) reaches the side surface portion 22 of the skin as shown by the chain line in FIG. 2, the skin side surface portion 22 is pushed to the side wall 12 side of the pad accommodating portion 13 and shown in FIG. As described above, the elastic sealing material 25 of the side surface portion 22 is pressed against the side wall 12 of the pad accommodating portion 13 to seal between the skin side surface portion 22 and the side wall 12 of the pad accommodating portion 13. At this time, the skin side surface portion 22 is in a state of less waviness due to the elastic seal material 25, and the elastic seal material 25 is compressed by its elasticity and adheres tightly to the side wall 12 of the pad accommodating portion 13. Side surface portion 22 and pad accommodating portion 1
The side walls 12 of 3 are reliably sealed, and the foam (foaming raw material) is prevented from leaking out of the skin 21 from the side surface portion 22 of the skin 21. Then, due to the self-adhesiveness of the foam (foaming raw material P) generated at the time of foaming, the foam and the outer skin 21 are bonded to each other to form a pad, and the foam is the core 11
Glue with.

Thereafter, the molding die is opened and the molded product is taken out to obtain a desired plastic molded product with a pad.
The obtained molded product has the side surface portion 22 of the skin 21 as described above.
Since the space between the side wall 12 of the pad accommodating portion 13 of the core 11 is sealed and foam-molded, the foam does not leak from the skin side surface portion 22 and the appearance is good. In addition, the elastic sealing material 25 is attached to the open end 2 of the skin side surface portion 22.
The one provided near 3 has the elastic sealing material 25 located deeply between the skin side surface portion 22 and the side wall 12 of the pad accommodating portion 13 of the core 11 and cannot be seen from the outside. Is good.

In the above-mentioned embodiment, the closed injection in which the liquid foaming raw material is injected after the molding die is closed is shown. However, the liquid foaming raw material is injected with the molding die opened, and then the open injection is performed. Of course, in this case as well, the seal structure of the present invention can be used.

[0019]

As shown and described above, according to the seal structure in the integral foam molding of the present invention, the rigidity of the side surface portion is increased by the elastic sealing material provided on the side surface portion of the skin, and the skin is placed on the molding die. It is possible to prevent the side surface portion of the epidermis from being deformed such as corrugated during the molding and the closing of the mold. Moreover, since the elastic sealing material adheres to the side wall of the pad accommodating portion of the core due to its elasticity during foaming of the foaming raw material, it is possible to enhance the sealing property between the side surface portion of the skin and the side wall of the pad accommodating portion, thereby preventing the foam from leaking. A padded plastic molded product with a good appearance can be obtained.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a molding die showing a case where a plastic molded product with a pad is integrally molded using the seal structure of the present invention.

FIG. 2 is an enlarged cross-sectional view of a main part of a molding die showing the foaming process.

FIG. 3 is an enlarged cross-sectional view of a main part of a molding die showing a sealed state during foaming.

FIG. 4 is a partial perspective view showing an example of an epidermis used in the present invention.

FIG. 5 is a perspective view showing an example of a plastic molded product with a pad.

FIG. 6 is a cross-sectional view of a molding die showing a conventional seal structure during integral foam molding.

FIG. 7 is an enlarged cross-sectional view of a main part thereof.

FIG. 8 is a partially cutaway perspective view showing a deformed state of a side surface portion of a skin in a conventional seal structure.

[Explanation of symbols]

 11 Core 12 Side Wall 13 Pad Housing 21 Skin 22 Side of Skin 25 Elastic Seal Material P Foaming Raw Material

Claims (1)

[Claims] 1. A pad accommodating portion, which is wholly or partially surrounded by a side wall formed in a predetermined part of a core, is arranged such that a side surface portion of its skin is substantially in contact with a side wall of the pad accommodating portion. Then, in the integral foam molding in which the foaming raw material is foamed in the pad accommodating portion, an elastic seal material is provided on the skin side surface portion in contact with the side wall of the pad accommodating portion, and the skin side surface portion is padded via the elastic seal material during the foaming. A skin side surface seal structure in integral foam molding, which is pressure-bonded to a side wall of a housing portion.