JPH0592486A - Method for manufacturing article having foam layer - Google Patents

Abstract

(57) [Summary] (Modified) [Purpose] A foam layer is disposed on the mold surface and a reinforcing layer is integrally molded to form an adherend, and at the same time, the appearance is prevented from being impaired. A skin material composed of a foam layer 21 and a skin layer 22 formed integrally on the surface of the foam layer 21 is arranged on a mold surface, and a resin reinforcing layer is formed on the back surface side of the foam layer 21 to form a cover. The forming step for forming the adhesive material 2 and one of the adherend material 2 and the base material are vibrated at a low frequency while the base material is in contact with the reinforcing layer 20, and the adherend material and the base material are welded and integrated. The method for producing an article having a foam layer 21 is characterized in that a reinforcing layer is formed in a portion of the adherend 2 excluding a corner portion in the forming step.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing gripping articles such as assist grips and seat grips of automobiles, or articles such as armrests having a foam layer and having a soft feeling.

[0002]

2. Description of the Related Art An interior of an automobile or the like is provided with an assist grip for supporting an occupant's body. As shown in FIG. 6, this assist grip has a grip portion 100.
And a mounting portion 101 extending from both ends of the grip portion 100, and the mounting portion 101 is fixed to the vehicle body with screws or the like.

Conventionally, a molded article made of resin has been used for this assist grip, but the feel when gripped is hard and it cannot be said that it has a good appearance. Therefore, in recent years, an assist grip having a foam layer has been generally used. Such an assist grip is composed of a resin base material required to maintain strength and a foam layer coated on the surface of the base material. The foam layer surface is covered with an integral skin layer. Is normal. The foam layer is generally provided on the grip portion, and the base material projects from both ends of the grip portion to form an attachment portion. Also, in terms of appearance, the surface of the grip part and the surface of the mounting part are
It is usually continuous so that they have almost the same surface.

As a method of manufacturing an assist grip having such a foam layer, a base material having a small diameter portion is first formed in a central portion, and a soft material made of a foaming layer and a skin layer is separately formed by a laminating method or the like to have a small diameter. The grip portion is formed by winding the end portion of the soft material around the portion. Since it is not preferable for the grip portion to move relative to the base material, the base material and the foam layer are integrally fixed by adhesion or the like.

[0005]

The conventional method for manufacturing an assist grip described above has a problem that a bonding step and a sewing step are required to form the grip portion, resulting in a large number of steps. Therefore, the inventors of the present application have previously applied for a manufacturing method in which the grip portion is formed by utilizing the vibration welding method (Japanese Patent Application No. 2-291282). According to this manufacturing method, an adherend composed of a resin reinforcement layer and a foam layer having a skin integrally formed on the surface of the reinforcement layer is held from the foam layer side, and is formed from a resin that can be welded to the reinforcement layer. In this method, the base material is vibrated at a low frequency while being in contact with the reinforcing layer, and the reinforcing layer and the base material are vibration-welded and integrally joined. According to this method, even if the gap between the base material and the adherend is eliminated, the elastic deformation of the foam layer can ensure the amplitude during vibration welding, thus improving the appearance.

By the way, in forming the adherend in this method, it is convenient to dispose the foam layer on the mold surface and form the reinforcing layer by compression molding or the like. However, if the resin protrudes from the foam layer during molding, the amplitude during vibration welding cannot be ensured, and the welding is hindered. Also, if the reinforcing layer is formed in a shape that is slightly smaller than the foam layer, the amplitude will be secured and welding will not be hindered, but the end of the foam layer will rise from the base material after being welded or peeled off from the base material, and it will look good. bad. Further, in the compression molding, the foam layer contacting the reinforcement layer is partially melted, and the thickness of the foam layer may be partially different due to the presence or absence of the reinforcement layer. In such a case, there is a problem that the amount of springback of the foamed layer after compression molding is different, and a step is formed on the surface of the skin to impair the appearance.

The present invention has been made in view of the above circumstances, and a foam layer is disposed on a mold surface to integrally form a reinforcing layer to form an adherend and prevent deterioration of appearance. The purpose is to do.

[0008]

A method for manufacturing an article having a foam layer according to the present invention, which solves the above-mentioned problems, is a method of molding a skin material comprising a foam layer and a skin layer integrally formed on the surface of the foam layer. The molding process of arranging on the surface and forming the adherend by forming the resin reinforcement layer on the back side opposite to the skin layer of the foam layer, and the reinforcement layer and the base material formed from the resin that can be welded In a state of being brought into contact with the layer, one of the adherend and the base material is vibrated at a low frequency to vibrate the adherend and the base material, and the vibration welding step of integrally joining the foamed layer is provided. The method for manufacturing an article is characterized in that a reinforcing layer is formed in a portion of the adherend excluding a corner portion in the molding step.

The forming step is a step of forming an adherend. Here, the adherend is composed of a skin material including a foam layer and a skin layer, and a resin reinforcing layer. For the foam layer, a conventionally known foam sheet such as polyurethane foam and vinyl chloride foam can be used. Further, as the skin layer, those conventionally used as a skin such as leather, vinyl chloride resin, and woven fabric can be used. The skin material is obtained by integrally laminating the foam layer and the skin layer, and it is convenient to laminate the skin material by, for example, a laminating method.

Then, in the molding step, this skin material is placed on the mold surface, and a reinforcing layer is integrally formed on the back surface side of the foam layer opposite to the skin layer by in-mold molding. Here, in the present invention, the reinforcing layer is formed in the portion excluding the corners of the foam layer. That is, when the skin material has a substantially rectangular shape, the reinforcing layer is formed on the portions excluding the four corners. Further, when the skin material has a substantially triangular shape, the reinforcing layer is formed on the portions excluding the three corners. As a result, the resin is prevented from squeezing out from the corners where the resin is most likely to squeeze out, and an adherend having no resin squeezing out can be formed. As the molding means in the molding step, compression molding, injection compression molding or the like can be used.

In the vibration welding process, the adherend and the base material are integrally fixed by vibration welding. Here, in this step, it is desirable to perform vibration welding by fixing the adherend and vibrating the base material at a low frequency. Although it is possible to vibrate and adhere the adherend, vibration is partially absorbed by the foam layer, which impedes the transmission of vibration energy, resulting in insufficient welding strength and long welding times. .. The low frequency is used because it is difficult to weld through the foam layer by ultrasonic welding or the like. By vibrating the base material at a low frequency, there is little attenuation, and welding can be performed with high strength in a short time.

[0012]

In the manufacturing method of the present invention, the reinforcing layer is formed in the portion of the skin material excluding the corners in the molding step. That is, in the molding step, the resin is prevented from squeezing out from the corners where the resin is most likely to squeeze out. Therefore, at the time of vibration welding, since the amplitude is secured by the deformation of the foam layer, high welding strength can be obtained, and a gap between the adherend and the base material after welding can be eliminated.

Further, even if there is a difference in the amount of springback due to the presence or absence of the foamed layer, it is only in the corners and is hardly noticeable, so the appearance is not impaired. Since the reinforcing layer is present at the ends of the adherend excluding the corners, the skin material is prevented from rising or peeling after welding.

[0014]

EXAMPLES The present invention will be specifically described below with reference to examples. Figure 1
2 shows the assist grip manufactured in this embodiment. The assist grip is composed of a base material 1 and an adherend 2. The base material 1 is made of polypropylene mixed with a filler, a pigment and the like, and is formed by injection molding. This base material 1 has a small-diameter portion 10 having an elliptical cross-section formed in the central grip portion, and mounting portions 11 to be mounted on the vehicle body are formed on both sides of the small-diameter portion 10.

The adherend 2 has a reinforcing layer 20 made of polypropylene and a foaming layer 21 made of urethane foam integrally coated on the surface of the reinforcing layer 20, as shown in a plan view of the back surface side in FIG. And a skin layer 22 made of vinyl chloride resin that is integrally covered on the surface of the foam layer 21. The skin layer 22 is formed in a half-shape, and a pair of two covers the entire small-diameter portion 10. A plurality of ribs 23 extending in the axial direction of the small diameter portion 10 are provided on the surface of the reinforcing layer 20, and the tips of the ribs 23 are welded to the surface of the small diameter portion 10 so that the base material 1 and the adherend 2 are integrated. Is joined to. Further, there are notches 24 at the four corners of the reinforcing layer 20, and the notches 24 at the reinforcing layer 2
A stiffness of 0 is avoided.

The manufacturing method of this embodiment for manufacturing the above assist grip will be described below. (1) Molding Step FIGS. 4 and 5 show the mold used in the molding step. This mold is an injection compression molding mold composed of a lower mold 3 and an upper mold 4. The lower mold 3 holds a slide core 30 which is movable in the mold opening / closing direction (arrow direction in FIG. 4). The slide core 30 has a pair of convex portions 31 forming the cutout portion 24 of the reinforcing layer 20, and is provided on each of the left and right sides of the cavity.

The adherend 2 is formed by using the above mold. First, the skin material 200 in which the foam layer 21 and the skin layer 22 are integrally laminated and shaped into a box with a shallow bottom is prepared. The skin material 200 can be formed by laminating by a normal laminating method or the like and shaping by vacuum forming or the like. Both ends of the skin material 200 are connected to the protrusions 31 of the slide core 30.
It is sandwiched between the lower mold 3 and the lower mold 3, and the upper mold 4 is clamped to move the slide core 30. As a result, the skin material 2
00 is held in contact with the mold surface of the lower mold 3 as shown in FIG. 5, and injection compression molding is performed. At this time, the convex portion 3
The resin does not rotate in the four corners where 1 exists, and as a result, there is no protrusion, and cutout portions 24 are formed in those portions. Then, the reinforcing layer 20 integrally joined to the skin material 200 is molded to form the adherend 2. At the position of the cutout portion 24, the amount of springback of the skin material 200 is larger than that of the other portions, but since the area is small and the corner portion of the skin material 200 has a large rigidity, the appearance failure may occur. Don't (2) Vibration welding step The pair of left and right adherends 2 formed as described above is attached to the small-diameter portion 10 of the separately molded base material 1 in a tubular shape, and the adherend 2 is in that state. Then, it is pressed and held by the pressing jig from the skin layer 22 side. Then, the substrate 1 has an amplitude of 800 μm,
Vibrates at a low frequency of 200 Hz. The vibration direction is parallel to the extending direction of the ribs 23 of the reinforcing layer 20.

At this time, at both end surfaces of the adherend 2, the covered skin material 200 is compressed by the walls of the end portions of the small diameter portion 10 to secure the amplitude, and the base material 1 and the adherend 2 rub. It is welded together by heat. Also, on both end surfaces of the adherend 2,
Due to the elasticity of the foam layer 21 of the skin material 200, it is in close contact with the base material 1 over the entire circumference, and there is no gap and it looks good. Further, at the four corners of both end surfaces of the adherend 2, the resin skin material 20 is used in the molding process.
Since the protrusion from 0 is prevented, a sufficient amplitude at the time of vibration welding can be ensured and reliable welding can be performed.

In the assist grip obtained in this embodiment, the reinforcing layer 20 is not formed only in the notches 24 at the four corners. Therefore, there is no problem that the end portion of the adherend 2 is lifted or peeled off, the appearance is improved and the welding strength is high.

[Brief description of drawings]

FIG. 1 is a front view of an assist grip obtained in an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a plan view of a main part on the back surface side of the adherend obtained in one example of the present invention.

FIG. 4 is a perspective view of a main part of a lower die of a molding die used in one embodiment of the present invention.

FIG. 5 is a schematic cross-sectional view of the molding die used in the embodiment of the present invention when the die is clamped.

FIG. 6 is a perspective view of the assist grip when in use.

[Explanation of symbols]

1: base material 2: adherend 3: lower mold
4: Upper mold 10: Small diameter part 11: Mounting part 20: Reinforcing layer
21: Foam layer 22: Skin layer 23: Rib 24: Notch

Continuation of the front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display location B32B 27/12 7258-4F // B29K 105: 04 105: 06 B29L 31:58 4F

Claims (1)

[Claims] 1. A skin material comprising a foam layer and a skin layer integrally formed on the surface of the foam layer is disposed on a mold surface, and a resin material is provided on the back surface side of the foam layer opposite to the skin layer. A forming step of forming a reinforcement layer to form an adherend, and a base material formed of a resin that can be welded to the reinforcement layer in contact with the reinforcement layer and the adherend and the base material. A method for producing an article having a foamed layer, the method comprising: vibrating one of which is vibrated at a low frequency to weld and adhere the adherend and the base material integrally to each other. A method for producing an article having a foam layer, which comprises forming the reinforcing layer on a portion of the adherend excluding the corners.