JP3025162B2 - Skin side seal structure in integral foam molding - Google Patents

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 sealing structure in integral foam molding.

[0002]

2. Description of the Related Art Pad-mounted plastic molded articles having a pad having a core surface adhered to a foam surface have been used in various fields such as interior parts of automobiles and furniture. For example, in the instrument panel of the automobile, as shown in FIG. 5, depending on the design of the automobile, a pad 42 is partially provided on the surface of a core 41, or a pad is provided on the entire surface of the core. The provided one is used.

In recent years, as a simple method for producing the above-mentioned padded plastic molded article, an integral foam molding method has been proposed in which a foam of a pad is molded and the foam is integrated with a skin and a core. In the integral foam molding method, as shown in FIG.
The pad accommodating portion 52 which is entirely or partially surrounded by 1
Is disposed on the upper die 61, and the outer skin 72 having the side surface 71 formed on the edge is placed on the lower die 6 such that the side surface 71 is substantially in contact with the side wall 51 of the pad accommodating portion 52.
2, a foaming material P such as polyurethane is foamed between the inner surface of the pad accommodating portion 52 and the skin 72, and the resulting foam is integrated with the core 53 and the skin 72.

In this integral foam molding method, as shown in FIG. 7, a foaming material P fills a space between a core 53 and a skin 72 while generating a foaming gas as the foaming reaction proceeds.
Therefore, the pressure between the core 53 and the skin 72 increased by the foaming gas and the foam (foaming material) filled between the core 53 and the skin 72 cause the side surface portion 71 of the skin to be in the pad accommodating portion as shown by a chain line. The foam is pressed against the side wall 51 to tightly seal it, thereby preventing the foam from leaking from the side portion 71 of the skin. The integration of the foam with the skin and the core is performed by self-adhesion or the like generated when the foaming raw material P is foamed.

However, in the integral foam molding method,
Since the end of the side surface of the skin is an open end 73, the rigidity of the side surface 71 is low, and the side surface 71 of the skin is deformed by waving or the like during storage of the skin or when placing the skin in a mold. Tends to occur. Then, 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, and sealing failure is likely to occur. As a result, the foam (foam raw material) leaks from the gap S and adheres to the surface of the skin 72, or the foam of the pad becomes underfilled due to poor filling due to the leak, and the appearance or quality of the molded product is reduced. There is a problem that causes reduction. In particular, as understood from FIG. 5, when the pad 42 is arranged on the surface of the core 41 (the reference numeral 51 in FIG. 7), the foaming material flows from the boundary 43 onto the core 41 (51) or the skin of the pad 42. Leaking up (reference numeral 72 in FIG. 7) is a fatal decorative defect. In addition, since the deformation habit once attached to the side surface of the skin is hardly restored by heating the skin, the problem is not easily solved.

[0006]

SUMMARY OF THE INVENTION Therefore, the present invention
When the foam is integrally molded with the skin and the core, the sealing structure on the side of the skin can effectively prevent the leakage of the foam from the side of the skin and obtain a plastic molded product with a good appearance and quality. It is intended to provide.

According to the present invention, a side formed on a predetermined portion of a core is provided.
Pad accommodating part surrounded all or part by the wallInside
And put the epidermis on the side of the edgeOutsideIs the side of the pad housing
wallInsideAnd the pad housing portion
In the integral foam molding for foaming the foaming material within,
Side wall of pad housingInsideOf the side of the epidermis in contact withOutsideBullet
An elastic sealing material is provided, and the elastic sealing material is interposed at the time of foaming.
And the side of the skinOutsideThe pad housing side wallInsideCrimp to
The skin side in integral foam molding characterized by
Pertaining to a part seal structure.

[0008]

The skin side surface portion provided with the elastic sealing material is reinforced by the elastic sealing material, so that the skin side surface portion is less likely to be deformed by waving or the like when it is arranged on a split mold surface. Therefore, when the outer surface of the side surface of the skin is pressed against the inner surface of the side wall of the pad accommodating portion via the elastic sealing material by the foam and the foaming pressure filled between the skin and the core,
The outer surface of the skin side portion is in close contact with the inner surface of the side wall of the pad accommodating portion without any gap via the elastic sealing material, and the skin side portion is well sealed. Further, even if the skin side surface is slightly deformed, the elastic sealing material is elastically deformed and absorbs the deformation of the skin side surface.
The outer surface of the can in close contact with the inner surface of the side wall of the pad housing part, can be satisfactorily sealed between inner surface of the side wall of the outer surface and the pad housing portion of the skin side portion.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a cross-sectional view of a molding die showing an integrated molding of a padded plastic molded product using the sealing structure of the present invention. FIG. FIG. 4 is an enlarged sectional view of a main part of a molding die showing a sealing 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 pads on one entire surface, 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 the like, or a plastic having high shape retention such as fiber-reinforced plastic. In addition, the core 11 of this embodiment has an injection port 14 for injecting (closed injection) the liquid foaming material into the pad housing 13 with the mold closed.
Are formed so as to penetrate the inside and outside. The core 11
May have a pad accommodating part in a part like the core shown in FIG. 6, and the side wall 12 does not surround the entire periphery of the pad accommodating part 13 but partially surrounds it. Is also good. That is, the pad housing 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 in a desired shape by vacuum molding or slash molding or the like, and has a side portion 22 bent to the back side at the edge. The side surface portion 22 is a pad accommodating portion 13 of the core 11.
It is formed so as to fit into.

As can be better understood from FIG. 3 which shows a part of the skin 21 on the outer surface of the skin side 22, a necessary portion of the outer surface of the side 22, that is, the pad accommodating portion of the core is provided. A string-shaped elastic sealing material 25 is provided on a portion in contact with the inner surface of the side wall 12 by bonding or the like along the open end 23 on the outer surface of the side surface portion 22. This elastic sealing material 2
5 is to increase the rigidity of the skin side portion 22 to prevent the skin side portion 22 from being deformed by waving or the like when placing the skin 21 on the molding die and closing the molding die, This is for sealing between the outer surface of the skin side surface portion 22 and the inner surface of the side wall 12 of the pad housing portion 13 of the core 11 during foaming. The material of the elastic sealing material 25 is made of an elastic material such as a soft foam such as a polyurethane foam, a nonwoven fabric, or a foam-type hot melt resin. In addition, the elastic sealing material 25 is applied to the surface 2 of the skin 21.
Preferably, it is provided near the open end 23 of the side surface portion 22 that is far from the position 4. By doing so, the rigidity of the open end 23 of the skin side surface portion 22 is further increased, and the sealing performance is further enhanced, and the elastic sealing material 25 is not visible from the surface side of the skin 21 to further improve the appearance of the molded product. be able to. As an example, a cord-like polyurethane foam having a cross section of 2 mm × 2 mm is placed 3 mm from the open end 23 of the skin side 22.
The example provided at a position above mm is given. The number of the elastic seal members 25 is not limited to one as in this embodiment, and two or more elastic seal members may be provided in parallel. Then, the rigidity of the skin side surface portion 22 is further increased, and the effect of preventing deformation of the side surface portion 22 such as waving can be further enhanced.

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

Due to the closed mold, the skin 21 is formed on the side 22
Is fitted in the pad accommodating portion 13 of the core 11 to cover the pad accommodating portion 13. At this time, epidermis 2
The outer surface of the side portion 22 of the first side is inside the side wall 12 of the pad housing portion 13
Surface or the open end 23 at the tip is
It will be slightly away from the inner surface . However, the skin 21
Since the rigidity of the side surface portion 22 is increased by the elastic sealing material 25, deformation such as waving is unlikely to occur when the skin 21 is arranged and when the mold is closed, and the outer surface of the side surface 22 of the skin 21 and the side wall 12 of the pad housing portion 13 are formed. There is no irregular gap between the inner surfaces .

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

The injected foaming material P fills the pad housing 13 while initiating a foaming reaction to form a foam. Then, when the foam (liquid foaming raw material P) reaches the side surface portion 22 of the skin as shown by a chain line in FIG. 2, the skin side portion 22 is pushed toward the inner surface of the side wall 12 of the pad accommodating portion 13, and FIG. As shown in the figure, the elastic sealing material 25 on the outer surface of the side surface portion 22 is pressed against the inner surface of the side wall 12 of the pad housing portion 13 to seal between the outer surface of the skin side surface portion 22 and the inner surface of the side wall 12 of the pad housing portion 13. At this time, the skin side portion 22 is made of an elastic sealing material 25.
As a result, the elastic sealing material 25 is compressed by its elasticity and closely adheres to the inner surface of the side wall 12 of the pad accommodating portion 13, so that the outer surface of the side surface 22 of the skin 21 and the side wall of the pad accommodating portion 13 are formed. The sealing between the inner surfaces 12 is reliably performed, and leakage of the foam (foaming material) from the side surface portion 22 of the skin 21 to the outside of the skin 21 is prevented. The foam and the skin 21 adhere to each other due to the self-adhesiveness of the foam (foaming material P) generated at the time of the foaming to form a pad, and the foam further adheres to the core 11.

Thereafter, if the mold is opened and the molded product is taken out, a desired plastic molded product with a pad is obtained.
The obtained molded product is, as described above, the side portion 22 of the skin 21.
Since the outer surface and the inner surface of the side wall 12 of the pad accommodating portion 13 of the core 11 are sealed and foamed, the foam does not leak from the skin side surface portion 22 and the appearance is good. In the case where the elastic sealing material 25 is provided near the open end 23 of the skin side surface portion 22, the elastic sealing material 25 is located deep between the outer surface of the skin side surface portion 22 and the inner surface of the side wall 12 of the pad accommodating portion 13 of the core 11. Since it is not visible from the outside, the appearance of the joint between the pad and the core is good.

In the above-described embodiment, the closed injection in which the liquid foaming material is injected after the mold is closed has been described. However, the liquid foaming material is injected in a state in which the mold is opened, and then the open injection is performed in which the mold is closed. It is natural that the seal structure of the present invention can be used also in the case of (1).

[0019]

As shown and described above, according to the sealing 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 outer surface of the side surface portion of the skin, and the skin is formed into a mold. This prevents the side surface of the skin from being deformed, such as waving, when it is placed in the mold and when the mold is closed. Moreover, since the elastic sealing material adheres to the inner surface of the side wall of the pad receiving portion of the core due to its elasticity when the foaming material is foamed, the sealing property between the outer surface of the skin side surface portion and the inner surface of the side wall of the pad receiving portion can be improved, A plastic molded product with a good appearance without leakage or the like can be obtained.

[Brief description of the 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 a sealing structure of the present invention.

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

FIG. 3 is an enlarged sectional view of a main part of a molding die showing a sealing state at the time of foaming.

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

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

FIG. 6 is a sectional view of a molding die showing a conventional sealing structure at the time of integral foam molding.

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

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

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Core 12 Side wall 13 Pad accommodating part 21 Skin 22 Skin side surface 25 Elastic sealing material P Foaming material

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-6-23767 (JP, A) JP-A 63-132716 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B29C 39/00-39/44 B60K 37/00

Claims (1)

(57) [Claims] To 1. A within pad housing portion all around or partly surrounded by the formation sidewall in a predetermined portion of the core, so that the side external surface of the edge of the skin contact substantially with the inner surface of the side wall of the pad housing part In the integral foam molding for foaming the foaming material in the pad accommodating portion, an elastic sealing material is provided on an outer surface of a skin side portion that is in contact with an inner surface of a side wall of the pad accommodating portion. A skin side surface sealing structure in integral foam molding, wherein an outer surface of a skin side portion is pressed against an inner surface of a side wall of a pad housing portion via a sealing material.