JPS5924018B2 - mall - Google Patents

Abstract

PURPOSE:To convert pressing force into bonding force effectively by providing a convex part at the bottom part of the bead, forming a small room between the same and the side part of the bead and thereby lessening the bending moment due to the pressing force of the bead to eliminate the floating of the end part thereof. CONSTITUTION:The convex part 8 is provided at the bottom part of the bead and the small room 9 is formed between the same and the side part 6 of the bead and filled up with a foamed substance in the same way as in the hollow part of the bead. Therefore, the pressing force applied on the upper surface of the bead is transmitted to the bottom surface through the intermediary of the convex part, while the bending moment MF acting on the end part of the bead acts around a supporting point Q, and thus floating up force for the end part is lessened. Therefore, the pressing force is converted effectively into the bonding force.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a protective and decorative molding made of synthetic resin or rubber.

More specifically, it is a molding that has an internal foamed part (hereinafter referred to as foamed part) with an adhesive layer formed on the back surface, and is designed to take full advantage of the adhesive strength of the adhesive layer and prevent poor adhesion. Regarding.

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 weight reduction, cushioning properties, absorption of impact stress, and material saving.

In particular, moldings used in automobiles have tended to become larger in recent years, and when they become larger, they require a certain degree of hardness and strength even if the inside is hollow, and there are restrictions on the shape of the material, so they weigh less. An increase in the adhesive strength is unavoidable, leading to a future decrease in the adhesion 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 the usage conditions and environment, so expansion, contraction, vibration, etc. of the moldings act greatly in proportion to the size of the moldings. , the following facts were found.

That is, as shown in FIG. 4, the conventional general hollow molding 11 has a hollow part 13 formed inside the molding body 12,
An adhesive layer 14 is provided on the back surface.

The molding body 12 has a surface portion 15, a side portion 16, and a bottom portion 17.
Consisting of

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 (・leaning) as shown in FIG. 5, and the pressing force for adhesion is reduced. The reason for this can be explained as follows.

In FIG. 6, the pressing force with a roll or the like is the pressing force acting in the vertical direction when pressed, and the bending moment MF acts between the surface portion 15 and the side portion 16.

With respect to this pressure bonding force and bending moment, a reaction force W and a moment M of the reaction force are applied to the adhesive layer 14 of the bottom part 17 toward the surface side.
W works.

If the pressure force F and the reaction force W are on a straight line, or if the reaction force W is on the MF side, the bending moment M
F and the reaction force moment MW are suppressed and reduced, and the pressing force applied to the molding upper surface part 15 is properly transmitted to the adhesive layer 14, and sufficient adhesive force is obtained.However, in the opposite case, the bending moment is As the molding increases, most of the pressing force on the molding becomes a bending moment and a reaction force moment, and as a result, the end of the main body of the molding curves and lifts up as shown in Figure 5, and sufficient adhesive force is not transmitted to the adhesive layer. ,
This will result in poor adhesion.

Furthermore, regarding this point, we will focus on the pressing force and bending moment and explain in detail based on the diagrams shown in Figs. 7 and 8. The pressing force when pressing with a roll etc. The bending moment MF occurs at Q.

Here, the pressure force F is the surface pressure cloth (arrow) as shown in Figure 7.
becomes.

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.

fwdX+F=0 In other words, the sum of the integral of the surface pressure and the pressing force is O.

At this time, the relationship between the bending moment MF and the surface pressure balanced against it is f w x d x +MF=0.

In other words, the sum of the bending moment and the counterbalancing pressure is 0.
becomes.

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. Power(
Negative pressure) acts as a force in the direction of separating the molding from the adhesive.

Therefore, in conventional hollow or internal foam moldings, when adding the surface pressure distribution corresponding to the pressure bonding force and the surface pressure distribution that balances the bending moment, at the point of application P, the bending moment is The balanced surface pressure is O, and all of the surface pressure (positive pressure) against the crimping force becomes the adhesive force, but as you get closer to the edge of the molding side, the surface pressure (positive pressure) against the crimping force decreases. , the surface pressure (negative pressure) that balances the bending moment increases, so the pressure that contributes to the adhesive force decreases significantly, and the surface pressure distribution (positive pressure) with respect to the crimping force at the edges almost disappears. There is only surface pressure (negative pressure) that balances the bending moment.

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, this invention makes the vertical force applied to the molding during pressing, that is, the bottom of the pressure force, as thick as possible to reduce the bending moment, offsets the bending moment with the reaction force W, and contributes the reaction force to the adhesive force. It is an object of the present invention to provide an internally foamed molding in which pressing force on the molding is effectively converted into adhesive force by allowing the molding to be generated in the direction of the foaming.

That is, the gist of the present invention is to provide a synthetic resin molding comprising a front surface, a bottom having an adhesive layer on the back, a side, and an internal foamed section provided at least on the inner surface of the front. A convex part is provided on one or both sides of the bottom of the mold, and a hollow or foam-filled small chamber is formed between the convex part and the side part of the mold. The molding is characterized in that the upper part of the convex part and the small chamber are connected to each other by a hollow part or a foamed material.

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, in which a molding 1 is a main body 2.
and an adhesive layer 4, and the main body 2 is composed of a surface portion 5, a side portion 6, and a bottom portion 7 so as to surround the foamed portion 3.

Semicircular convex portions 8 are protruded from both sides of the bottom portion 7, and the side portions 6
are connected to each other with approximately the same thickness as the surface portion 5, and this side portion 6
A small chamber 9 is formed between the convex portion 8 and the convex portion 8 .

This small chamber 9 communicates with the foaming part 3 at the upper part of the convex part 8 and is filled with the same foam as the foaming part.

The molding body 2 is formed by extrusion molding, for example, from vinyl chloride resin, but the material, molding method, etc. are particularly limited as long as it has elasticity suitable for the purpose and use.

The foam portion 3 may be any foam that has resilience and flexibility, and may be made of urethane, vinyl chloride resin, polyolefin resin, etc., and may be extruded integrally with the mold body 2 or formed separately. The molded foam part is integrated with the mold body by gluing or welding, or 53jlCB
It is constructed by a method such as inserting a molded foamed part into the molding body.

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 point different from the embodiment of FIG. 1 of the molding 1a is that the convex portion 8a is triangular.

Accordingly, the shape of the small chamber 9a is also different, and the volume is larger.

The groove 10 recessed in the surface portion is a decorative recess.

Next, we will discuss the operation of the molding of this invention when installing it (the third
This will be explained based on the diagram.

The molding 1 is pressed onto the adherend A with a presser jig B such as a roll, thereby adhering the molding 1 to the adherend A with a tacky adhesive that is the adhesive layer 4 on the back side.

At this time, the mold of the present invention does not have a thick side part 6 like the conventional mold, but has a thin small chamber 9 containing a foam.
Since the convex portions 8 are formed at both ends of the bottom portion 7 through
, resulting in a force in the vertical direction, that is, a pressing force F.

In addition, at this time, since the surface part 5 and the side part 6 are thin and connected and have a small chamber 9 containing the foam, the fulcrum of the bending moment due to the pressing force of the surface part 5 is the side part. Move to the bottom of 6.

Therefore, the surface pressure generated by this bending moment acts in the opposite direction to that of conventional hollow or internal foam moldings and contributes to adhesive force, so the pressure force is increased and the pressing force on the molding acts 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 1 show action diagrams similar to those in the conventional case regarding the pressing force and bending moment that act on the molding of this invention.
Shown in Figure 0.

The pressing 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 is as shown in the figure on the molding surface side (positive direction) with the peak at the force application point P. The pressure W decays on both sides.

The relationship between crimp force F and surface pressure W is as described above. fwdx+F=0 The relational expression holds true.

Further, the bending motion (MF) works as shown in FIG. 10 with the lower part Q of the molding side portion 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 O, and its value acts on the molding surface portion (in the positive direction).

The integral of this surface pressure is the reaction force [-ment, and the relationship between the bending moment MF and the surface pressure W is based on the same relational expression fwxdx-+-MF=0 as described above.

As can be seen from FIGS. 9 and 10, in the molding of the present invention, the contact pressure W, L, and displacement that balance the bending moment due to the pressing force act in the direction of the mold surface, that is, in the positive direction, so that the sum of are added together and all contribute as pressure to increase the adhesive strength.

Therefore, the pressure-sensitive double-sided adhesive tape of the adhesive layer can fully exhibit its function, and it is possible to obtain strong adhesive force without producing the 71 eggplant effect.

Note that even if an adhesive layer is formed on the back side of the foamed part 3 in the middle of the bottom, unlike solid beer (・sufficient adhesive strength cannot be obtained)
Therefore, it is recommended to design the adhesive strength 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.

Furthermore, the bottom part from which this adhesive layer has been removed does not substantially have a sufficient function as a molding. It is also possible to leave only the convex part 8b with the formed part and remove the middle bottom part (.

In addition, depending on the usage condition of the molding, it may be sufficient to form the convex part on one side rather than on both sides as in the above example, and in the case of a large molding, the convex part may be formed on the center part as appropriate in addition to both sides. A convex portion can be formed.

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.

Furthermore, since it has an internal foamed part, it can maintain its shape even if the wall thickness of the surface part is made thinner compared to a hollow molding, which reduces weight and prevents deformation due to temperature changes, especially in high-temperature environments. I can do it.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing one embodiment of the mall of this invention;
The figure is a cross-sectional view showing another embodiment, and FIG. 3 is a cross-sectional view showing the behavior of the molding in accordance with the present invention when bonded using the crimping jig.
Figure 4 is a sectional view of a conventional hollow molding, Figure 5 is a sectional view showing the behavior of a conventional molding when bonded with a crimping jig, and Figure 6 is a sectional view of a conventional hollow molding.
The figure is a model diagram 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, and Figure 8 is also a diagram showing the bending moment and the contact pressure balanced against it. FIG. 9 is a diagram showing the relationship between the pressure bonding force of the molding of the present invention and the surface pressure distribution thereof.
FIG. 10 is a diagram showing the relationship between the bending moment and the surface pressure distribution balanced thereto, and FIGS. 11 and 12 are sectional views showing still another embodiment of the present invention. 11.1a... Molding, 2... Main body, 3... Foaming part, 5... Surface part, 6... Side part, 7... Bottom part, 8
．． 8a, 8b... Convex portion, 9, 9a... Small chamber, 4, 1
4...Adhesive layer.

Claims (1)

[Claims] 1 In a synthetic resin molding consisting of a front surface part, a bottom part with an adhesive layer on the back surface, a side part, and an internal foamed part provided at least on the inner surface of the front surface part, the side part has a wall thickness along the surface part. A convex portion is provided protrudingly on one or both sides of the bottom of the mold, a hollow or foam-filled small chamber is formed between the convex portion and the side portion of the mold, and the internal foamed portion and the small chamber are connected to the convex portion. A molding characterized in that the upper part of the molding is hollow or communicates with a foam.