JPS6311178B2 - - Google Patents

Description

[Detailed Description of the Invention] This invention provides protection made of synthetic resin or rubber, etc.
Concerning decorative moldings. More specifically, the present invention relates to a hollow molding having an adhesive layer formed on the back surface of the molding body, which makes full use of the adhesive force of the adhesive layer to prevent poor adhesion.

2. Description of the Related Art Hollow moldings, in which the inside of the molding body is hollow, are used in automobile moldings and the like for the purpose of reducing weight, cushioning properties, absorbing impact stress, and saving materials.

Particularly in recent years, there has been a tendency for moldings used in automobiles to become larger, and as they grow larger, they require a certain degree of hardness and strength even if the interior is hollow, and there are restrictions on the shape of the material, which increases weight. This was unavoidable, and this resulted in a decrease in the adhesive strength of the adhesive layer. Note that the adhesive layer of the molding is usually attached using a double-sided adhesive tape.

When this hollow molding is enlarged, the adhesive force decreases significantly, especially in automobiles. This is because automobiles are significantly affected by thermal changes such as high and low temperatures and vibrations due to usage conditions and environments, so expansion/contraction of the molding, vibration, etc. act greatly in proportion to the size of the molding. , the following facts were found.

That is, as shown in FIG. 4, a conventional general hollow molding 11 has a hollow part 13 formed inside a molding body 12, and an adhesive layer 14 is provided on the back surface. The molding body 12 has a surface portion 15 and a side portion 1.
6, and a bottom part 17. When such a hollow molding 11 is pressed with a jig such as a roll in order to adhere to an adherend, both ends become floating as shown in Fig. 5, and the pressing force for adhesion is insufficient. do not participate in The reason for this can be explained as follows.

In Figure 6, the pressing force with rolls etc. is the pressing force F acting in the vertical direction when pressing and the bending moment.
MF acts between the surface portion 15 and the side portion 16. In response to this pressing force and bending moment, a reaction force W and a moment MW of the reaction force act on the adhesive layer 14 of the bottom part 17 toward the surface side. When the application points of the pressing force F and the reaction force W are in a straight line, or when the reaction force W is on the bending moment MF side, the bending moment MF and the reaction force moment MW are suppressed, become smaller, and are applied to the molding upper surface part 15. The pressing force is properly transmitted to the adhesive layer 14 and sufficient adhesive force is obtained, but in the opposite case, the bending moment becomes large and most of the pressing force on the molding becomes a bending moment and a reaction force moment. As a result, the main body end of the molding
As shown in the figure, it curves and lifts up, and sufficient adhesive force is not transmitted to the adhesive layer, resulting in poor adhesion. Furthermore, regarding this point, focusing on the pressing force and bending moment, and explaining in detail based on the diagrams shown in FIGS. 7 and 8, the pressing force when pressing with a roll etc. This is the bending moment MF at Q. Here is the crimp force F
becomes a surface pressure distribution (arrow) as shown in FIG.
The surface pressure W attenuates as it goes from the force application point to the side end of the molding. On the side with a hollow part, almost no surface pressure is applied and it is ignored. At this time, the following relational expression holds between the pressing force F and the surface pressure W.

∫wdx+F=0 In other words, the sum of the integrated surface pressure and the pressing force is 0. At this time, the relationship between the bending moment MF and the surface pressure balanced against it is ∫wxdx+MF=0. In other words, the sum of the bending moment and the counterbalance pressure is zero.

The surface pressure when Figures 7 and 8 are combined becomes the pressure involved in adhesion of the adhesive layer, and the pressure acting in the direction of the back side of the molding is positive pressure that directly contributes to the adhesive force and acts on the opposite side. The force (negative pressure) acts in the direction of separating the molding from the adhesive. Therefore, in conventional hollow moldings, when adding the surface pressure distribution corresponding to the crimping force and the surface pressure distribution that balances the bending moment, at the force application point P, the bending moment is balanced because the fulcrum Q of the bending moment is at the bottom. The surface pressure is 0, and the surface pressure (positive pressure) relative to the crimping force is all the adhesive force, but as you go to the edge of the side of the molding, the surface pressure (positive pressure) relative to the crimping force decreases. , as the surface pressure (negative pressure) that balances the bending moment increases, the pressure that contributes to adhesive force decreases significantly, and at the edges, the surface pressure distribution (positive pressure) with respect to the bonding force almost disappears, and the surface pressure that balances the bending moment decreases significantly. Only the matching surface pressure (negative pressure) is required. Therefore, the pressure that contributes to adhesive force becomes negative pressure, which becomes a peeling force as opposed to adhesion. For this reason, the end portions of the side portions of the molding end up rising as described above.

In view of the above, the present invention maximizes the vertical force applied to the molding during pressing, that is, the pressure force, reduces the bending moment, offsets the bending moment with the reaction force W, and converts the reaction moment into adhesive force. It is an object of the present invention to provide a hollow molding in which pressing force on the molding is effectively converted into adhesive force by generating it in a contributing direction.

That is, the gist of the present invention is to provide a molding comprising a surface part, a bottom part, a side part, and a hollow part, in which an adhesive layer is formed on the back surface of the molding body, in which the side part is continuous with a thin wall having approximately the same thickness as the surface part. A convex part whose width increases toward the bottom part of the mold is provided on both sides of the mold longitudinally, and a groove is formed between the convex part and the side part of the mold, and the hollow part and the groove are formed. The molding is characterized in that the convex portion communicates with the upper portion thereof.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The mold of the present invention will be described below based on embodiments shown in the drawings.

FIG. 1 shows an embodiment of the present invention.
consists of a molding body 2 and an adhesive layer 4, and the molding body 2 has a surface part 5, a side part 6,
It consists of a bottom part 7. Semicircular convex portions 8 are provided on both sides of the bottom portion 7 to protrude along the longitudinal direction of the molding 1, and the side portions 6 are continuous with the surface portion 5 with approximately the same wall thickness.
A groove 9 is formed between the side portion 6 and the convex portion 8. This groove 9 communicates with the hollow part 3 at the upper part of the convex part 8. This molding body 2 is made of vinyl chloride resin by extrusion molding, for example.
The material, molding method, etc. are not particularly limited as long as the material has elasticity suitable for the purpose.

The adhesive layer 4 is preferably a butyl rubber tape (usually referred to as a double-sided adhesive tape) having adhesive adhesive applied on both sides, but is not particularly limited thereto.

FIG. 2 shows another embodiment of the present invention, and the basic difference from the embodiment of FIG. 1 of the molding 1a is that the convex portion 8a is triangular. Along with this, the shape of the groove 9a is also different, and a larger space is formed. The groove 10 recessed in the surface portion is a decorative recess.

Note that the shape of the convex portion is such that the width increases toward the bottom, as in each of the above embodiments.

Next, the operation of the molding according to the present invention when attached will be explained based on FIG. 3. Molding 1 to adherend A
By pressing with a presser foot B such as a roll, the adhesive layer 4 on the back surface is bonded with a tacky adhesive. At this time, in the molding of the present invention, the side portions 6 are not thick like conventional moldings, but are thin, and the convex portions 8 are formed at both ends of the bottom portion 7 via the grooves 9, so that the surface portion 5 is thin. Due to the pressing force applied to the end portion, the surface portion 5 comes into contact with the convex portion 8, resulting in a vertical force, that is, a pressing force F. Further, at this time, since the surface portion 5 and the side portion 6 are connected through a thin wall and have the groove 9, the fulcrum of the bending moment due to the pressing force of the surface portion 5 is shifted to the lower part of the side portion 6. Therefore, the surface pressure generated by this bending moment acts in the opposite direction to that of conventional hollow moldings and contributes to adhesive force, increasing the pressing force and allowing the pressing force on the molding to act extremely efficiently as adhesive force. , it is possible to fully utilize the adhesive strength of the adhesive layer to obtain reliable adhesive strength.

FIGS. 9 and 10 show action diagrams similar to those in the conventional case regarding the pressing force and bending moment acting on the molding of the present invention.

The pressure force F due to the pressing force applied from the molding surface is applied to the force application point P at the top of the convex part 8, and the surface pressure distribution thereon increases as the width of the convex part 8 approaches the bottom part 7, so it is localized. Instead, the pressure W is attenuated on both sides with a peak at the force application point P on the molding surface side (positive direction) as shown in the figure. Crimping force F and surface pressure W
As mentioned above, the relational expression ∫wdx+F=0 holds true.

Further, the bending moment MF acts as shown in FIG. 10 using the lower part Q of the molding side part 6 as a fulcrum. That is, the surface pressure W increases toward the convex portion 8, which is the inner side of the molding, with the position of the fulcrum Q as 0, and its value acts on the molding surface portion (in the positive direction). The integral of this surface pressure is the moment of reaction force, and the bending moment MF
The relationship between and the surface pressure W is based on the same relational expression as above: ∫wxdx+MF=0.

As can be seen from FIGS. 9 and 10, in the molding of this invention, the crimping force F due to the pressing force and the surface pressure W balanced against the bending moment both act in the direction of the molding surface, that is, in the positive direction, so the sum of these forces is Added together, they all contribute as pressure to increase adhesion. Therefore, the pressure-sensitive double-sided adhesive tape of the adhesive layer can fully exhibit its function, and it becomes possible to obtain strong adhesive force without producing any negative effects.

Note that even if an adhesive layer is formed on the back surface of the hollow part 3 in the middle of the bottom, almost no adhesive force is obtained, so
The adhesive strength is designed in advance so that adhesive strength can be obtained only at both ends where the convex portion 8 is formed without providing an adhesive layer. Further, since the bottom portion from which the adhesive layer has been removed does not substantially have any particular function as a molding, only the convex portions having the adhesive layer formed on the surface may be left and the intermediate bottom portion may be removed.

Since the molding of this invention has the above-mentioned structure, the pressing force when adhering the molding to the adherend can be very effectively converted into adhesive force, and sufficient adhesive strength can be obtained. It is possible to provide a hollow molding having adhesive strength that can sufficiently withstand temperature changes and vibrations.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing one embodiment of the molding of the present invention, FIG. 2 is a cross-sectional view of another embodiment, and FIG. 3 is a cross-sectional view showing the behavior of the molding of the present invention when bonded with a crimping jig. Fig. 4 is a cross-sectional view of a conventional hollow molding, Fig. 5 is a cross-sectional view showing the behavior of a conventional molding during adhesion using a crimping tool, and Fig. 6 is a model showing the force relationship due to the pressing force of the molding. Figure 7 is a diagram showing the relationship between the crimp force of a conventional molding and the contact pressure distribution, Figure 8 is a diagram showing the relationship between the bending moment and the contact pressure distribution balanced against it, and Figure 9 is a diagram showing the relationship between the bending moment and the contact pressure distribution in balance with it. FIG. 10 is a diagram showing the relationship between the compression force of the molding and the distribution of surface pressure corresponding thereto, and FIG. 10 is a diagram showing the relationship between the bending moment and the distribution of surface pressure balanced therewith. 1, 1a...Mall, 2...Mall body, 3...
...Hollow part, 4, 14...Adhesive layer, 5...Surface part, 6...Side part, 7...Bottom part, 8, 8a...Convex part, 9,9a...Groove.

Claims (1)

[Claims] 1. In a molding that consists of a surface part, a bottom part, a side part and a hollow part, and an adhesive layer is formed on the back side of the molding body, the side part is connected with a thin wall that is approximately the same thickness as the surface part, and a A convex part whose width increases toward the bottom part is provided protruding along the longitudinal direction of the molding, a groove is formed between the convex part and the side part of the molding, and the hollow part and the groove are formed at the upper part of the convex part. A mall that is characterized by being interconnected.