JPS6225496B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention mainly relates to an improvement in a high frequency bonding method used in manufacturing automobile door interior materials and the like.

By the way, interior materials for automobile doors are required to have a certain degree of mechanical strength, cushioning properties, and decorative properties.
For this reason, the above-mentioned normal interior materials are made of hardboard as the foundation material, urethane sponge as the cushioning material,
It is composed of a vinyl leather or sheet as a decorative member or a woven fabric of synthetic or natural fibers, and these three materials are integrated into a polymerized structure.

In manufacturing such interior materials, in order to efficiently polymerize and integrate the three types of components mentioned above, a method is adopted in which each component is melted and bonded in dots or lines using high-frequency dielectric heat generation. In order to improve the adhesion, members made of materials other than vinyl are usually coated with vinyl in advance on their mating surfaces.

However, in high-frequency bonding in this case, a considerably large amount of high-frequency power is used depending on the material and size of each of the above-mentioned members, so that the following problems arise. In other words, if the power supply is set high to ensure sufficient adhesion, the heating time can be shortened, but when the power is supplied, sparks are generated from the electrodes pressurizing each member, causing damage to the members, especially decorative members. This often results in damage to the interior of the product, thus rendering the product interior material defective. Also, if the power supply is set conservatively to avoid sparks,
This time, even if the heating time is increased, the adhesion becomes insufficient and the product is likely to be defective.

In order to deal with this problem, conventionally, the supplied power has been set approximately halfway between a value below which adhesion would be incomplete and a value at which sparks may occur. For example, if the supplied power is indicated by the dashed line A in Figure 5,
If the setting is 20Kw, as shown in , the adhesion becomes incomplete, and if the setting is 30Kw, as shown by the broken line B, sparks occur, then the setting is set to 25Kw, which is the middle between them, as shown by the solid line C. In this figure, Tr is the rise time of the supplied power,
Th is the heating time, and Tc is the cooling time immediately after heating.

However, such conventional measures are only ambiguous compromise solutions and do not fully solve the above-mentioned problems, and therefore may still cause sparks or cause insufficient adhesion. .

On the other hand, the above-mentioned undesirable sparks often occur when the entire tip of the electrode that presses the member to be bonded does not completely contact the member. In other words, high-frequency power tends to concentrate at the part of the electrode tip that is not in contact with the above-mentioned member, and this tendency is particularly strong at the edged end of the tip, which causes sparks. .
Therefore, in order to prevent the generation of sparks, it is sufficient to bring the entire tip of the electrode into complete contact with the above-mentioned member.
However, in reality, it is difficult to always achieve perfect contact due to the aforementioned warpage of the base member and uneven thickness of the decorative member, especially when the decorative member is made of two or more types of materials joined together. In the case of a joint, a step occurs at this seam, so it is almost impossible to achieve complete contact at this point.

In view of the above-mentioned circumstances, the present invention aims to improve high-frequency adhesion when producing interior materials for automobile doors or interior materials having a similar structure, by increasing the amount of high-frequency power supplied to electrodes. The power is changed during heating, making the power weaker in the first half and stronger in the second half, so that complete contact of the entire electrode tip can be achieved in the first half, and sufficient adhesion can be achieved in the second half. be. The details will be explained below with reference to the drawings.

First, to explain the general outline of a general high-frequency bonding device, as shown in Fig. 1, there is a pair of upper and lower surface plates 1 and 2 facing each other. It is supported so that it can be raised and lowered at any time. An electrode 4 which also serves as a mold is attached to the lower side of the surface plate 1, and the surface plate 2 also serves as the other electrode to be paired with this electrode. Note that both of these electrodes are appropriately connected to a high frequency power source 5, so that set high frequency power is supplied at any time.

Next, the interior material to which the method of the present invention is applied is shown in FIG. As shown in FIG. 1, this interior material 6 includes a plate-shaped base member 7 made of a relatively hard material such as hardboard, and a buffer member 8 made of an elastic material such as urethane sponge.
and a decorative member 9 made of vinyl leather or sheet or woven fabric of synthetic or natural fibers, etc. In the embodiment shown in FIG. 3, two different materials 9a and 9b are used as the decorative member 9.
A combination of these is used.

Such interior material 6 is manufactured using the above-mentioned apparatus in the following manner. First, as shown in FIG. 1, the base member 7 is placed on the lower surface plate 2, and the buffer member 8 and the decorative member 9 are sequentially placed on top of it. Next, the upper surface plate 1 is lowered, and the electrode 4 on the lower surface of the plate, which also serves as a mold, pressurizes each of the members 7, 8, 9, and at the same time, between this electrode and the lower surface plate 2. When high-frequency power is supplied, the parts of each member that are pressurized by the electrode 4 are heated by their own dielectric heat generation,
The above-mentioned pressurized parts of the coating layer of the member other than the base member 7 and the other members 8 and 9 are softened, some of them melt, and the three members are bonded 10 to each other.

However, during this bonding, the tip of the electrode 4 that applies pressure to each of the members 7, 8, and 9 does not necessarily come into complete contact with the decorative member 9 located on the top, and may partially contact incompletely. It may happen.
In particular, when the decorative member 9 is made by joining two kinds of materials 9a and 9b as shown in FIG. 3, there are steps 12 and 13 at the seam 11 as shown in FIG. When pressurized, as shown in FIG. 2, a portion 12' of incomplete contact is created between the tip of the electrode and a space 13' is also created between it and the buffer member 8. Therefore, if high-frequency power is supplied in this state, there is a risk that sparks will occur in the above-mentioned portion 12', and poor adhesion will occur in the void 13'.

Therefore, the present invention deals with this point as shown in FIG.

That is, with the electrode 4 pressurizing each member 7, 8, and 9 as shown in FIG. 3, first, a weak high-frequency power of, for example, 20 Kw that does not generate sparks is supplied to heat the member for a time of Tha. . Then, the pressurized parts of the members 8 and 9 other than the base member 7 soften and deform to fill the space 12' and the void 13' near the seam 11, as shown in FIG. Even though the decorative member 9 has steps 12 and 13, the entire tip of the electrode 4 is brought into complete contact therewith, and the member is also brought into close contact with the buffer member 8 without any gaps. Further, the decorative member 9 is made of only one type of material,
Therefore, although the above-mentioned steps 12 and 13 do not exist, there are cases where the entire tips of the electrodes 4 cannot be brought into complete contact due to uneven thickness or other reasons, or when the decorative member 9 is woven. Even in cases where the electrode 4 is made of cloth and therefore gaps between the fibers prevent complete contact of the entire electrode tip,
Similarly, the entire tip is brought into complete contact with the decorative member 9, and the member is brought into close contact with the cushioning member 8 without any gaps. Of course, at this time, the coating layer of the base member 7 also softens.

Next, under such conditions, high-frequency power of, for example, 30 Kw, which is so strong that conventionally there would have been a risk of spark generation, is supplied to heat the material for a Thb period. However, at this time, the entire tip of the electrode 4 is in complete contact with the decorative member 9, and since there is no gap between the members 7, 8, and 9 at least in the pressurized parts, each of these members is free from sparks. Adhesion is sufficient without any generation.

In Fig. 4, Tra and Trb are the rise times of the supplied power, and Tc is the cooling time immediately after heating, during which time the newly bonded members were pressurized by the electrode 4. The bond remains in place and its adhesive state is fixed.

By the way, in the above embodiment, the electrode 4 which also serves as a mold
Although the present invention has been described as being applicable to a type of high-frequency adhesive device in which the electrode 4 is attached to the upper surface plate 1 and the lower surface plate 2 also serves as the other electrode, Of course, it is possible to implement the method in exactly the same manner for a type of high-frequency adhesive device in which the electrode is mounted upward on the lower surface plate 2, and the upper surface plate 1 also serves as the other electrode. . That is, among the door interior materials to which the present invention is directed, particularly for automobile door interior materials, elongated decorative moldings are often bonded to various parts of the surface of the decorative member 9 at the same time. teeth,
A high-frequency bonding device of the type in which the electrode 4 is mounted upwardly on the lower surface plate 2 as described above is rather more commonly used, but the present invention can be implemented with such a device as well.

As described above, the present invention relates to high-frequency bonding when producing the above-mentioned interior materials, by changing the strength of the high-frequency power supplied for heating during the heating process, and making the strength of the high-frequency power supplied for heating so weak that it does not generate sparks in the first half. Then, in the second half, a stronger electric power is supplied to bring the entire tip of the electrode into contact with the component of the interior material, and then to ensure sufficient adhesion of the component. Therefore, according to the bonding method of the present invention, each constituent member can be bonded well without the risk of generating sparks during the production of the above-mentioned interior material, and damage to decorative components caused by the sparks can be avoided. It is possible to reliably prevent the occurrence of defective products due to insufficiency.

[Brief explanation of the drawing]

Figure 1 is a front view schematically showing the high frequency bonding device;
Fig. 2 is a front view of the interior material to which the present invention is applied, Fig. 3 is an enlarged model diagram showing the embodiments of the present invention in the order of steps, and Fig. 4 is the high-frequency wave supplied in the above embodiments. Graph showing an example of power. FIG. 5 is a graph showing an example of high frequency power supplied in the conventional example. 1... Upper surface plate, 2... Lower surface plate, 4... Electrode, 5... High frequency power source, 6... Interior material, 7...
Foundation member, 8...Buffer member, 9...Decoration member, 1
0...Adhesive part.

Claims (1)

[Claims] 1. Regarding interior materials in which a plate-shaped base member, a cushioning member, and a decorative member are bonded in places and integrated by polymerization, in the high-frequency bonding method applied to the above-mentioned bonding of each of these members, the above-mentioned each member is overlapped. A lower surface plate that also serves as one electrode for placing the parts together, and a mold that is attached to the lower side of the upper surface plate that can be raised and lowered at any time toward the surface plate to pressurize each of the above members. The first electrode is supplied with high-frequency power that is weak enough that there is no risk of sparking, and then high-frequency power that is strong enough to ensure sufficient adhesion is supplied between the electrode and the other electrode. A high-frequency bonding method for automobile door interior materials, etc.