JPS6114970B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing an elastic bumper for an automobile equipped with a decorative molding.

In recent years, from the viewpoint of good cushioning performance as automobile bumpers, resilience after impact, and safety against other objects, elastic materials made of elastic materials such as rubber or synthetic resin have been used instead of conventional metal bumpers. Bumpers have come into use. Since this elastic bumper is made of a material such as rubber or synthetic resin, it cannot have the metallic appearance of conventional metal bumpers. Alternatively, it has been proposed to attach a decorative molding body having a decorative surface such as a metal vapor deposited layer. By the way, methods for attaching the decorative molding body to the surface of this elastic bumper include, for example, fitting the molding body into a recess provided on the surface of the elastic bumper, or bonding the molding body to the surface of the elastic bumper with an adhesive. A so-called in-mold integral molding method has been proposed, in which a molding body is installed in a mold for forming a bumper or an elastic bumper, and is attached integrally with the molding of the elastic bumper. Among these methods, the above-mentioned in-mold integral molding method is simpler in terms of process than other methods, and since the molding body is embedded in the bumper body, it creates a sense of unity and is easy to install on this type of bumper. This is an excellent method and is expected to be effective, but in the case of this in-mold integral molding, firstly, the molding body is affected by the flow direction of the molding material such as rubber or synthetic resin during molding. There was a risk that the molding material would be misaligned, and secondly, the molding material would wrap around and adhere to the decorative surface of the molding body, resulting in staining of the decorative surface, which was a fatal technical problem.

This invention was proposed to solve the above-mentioned technical problems in in-mold integral molding, and its gist is that a decorative surface is provided in the front part of an elastic bumper mold. and after providing a fixing groove having a width equal to or slightly smaller than the width of the decorative surface of the decorative molding body having embedded legs formed on the back side, and making the front part of the decorative molding body sandwich in the fixing groove. By injecting molding material into a mold and molding a bumper integrally embedded with the embedded legs of the decorative molding body, the molding body is positioned and the molding material is applied to the decorative side of the molding body. Its characteristics are that it prevents wraparound and protects the decorative surface.

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view of an elastic bumper 1 with a decorative molding body 2 attached thereto. Although the structure of the elastic bumper 1 is not shown, a semi-rigid synthetic resin foam, which serves as a shock absorbing element, is attached to a support frame on the vehicle side, and the elastic bumper is installed so as to cover the shock absorbing element or integrally with it. Some are equipped with a shock absorbing element, or the shock absorbing element is an air chamber, and the elasticity of the air is used for the shock absorbing effect. In the present invention, the elastic bumper or bumper body refers to an exterior portion made of rubber or synthetic resin that forms the outermost exterior of the bumper assembly as described above and substantially defines the bumper shape.

As shown in FIG. 2, the decorative molding body 2 is composed of a decorative surface 3 and a base layer 4.
is made of various synthetic resin materials commonly used for what is called a mold material, such as soft vinyl chloride resin, rubber, etc., and has a decorative surface 3 made of metal foil, metal vapor deposited layer, etc. on its upper surface side. The decorative molding body 2 used in this invention has a decorative surface 4 on the front part and an embedded leg part 6 on the back side. The shape of the embedded leg portion 6 may be an L-shaped cross section at the side end as shown in FIG. 2, or a linear leg portion as shown in FIG. 4, which will be described later. An appropriately shaped implantation leg can be formed.

3 and 4 show an embodiment of the invention. That is, the elastic bumper molds 10 and 11
A fixing groove 15 for clamping the decorative molding body 2 is provided in the lower die 10. This fixing groove 15 serves to position the decorative molding body 2 attached to the surface of the bumper main body by sandwiching the decorative molding body, and at the same time, when molding the elastic bumper, the molding material such as rubber or synthetic resin is Since this is to prevent it from going around the decorative surface 3 on the surface of the body 2, it is necessary to fit the side surface of the molded body 2 and firmly clamp the front part including the decorative surface. Therefore, the width of the fixing groove 15 is required to be equal to or slightly smaller than the width S of the decorative surface of the molding body 2. If the side surface of the molding body has elasticity due to the material of the base layer 4 of the molding body 2 or its cross-sectional shape, the width of the fixing groove 15 can be made smaller than the width S of the decorative surface by utilizing the elasticity. urge Conversely, in the case of a molded body 2 with low elasticity, the width of the fixing groove 15 will be approximately the same or slightly smaller. Note that the fixing groove 15 is located within the mold.
It may be formed by providing protrusions 12, 12' (see FIG. 3), or by drilling grooves in the mold itself (see FIG. 4). This problem is determined by whether the decorative molding body is embedded inside the bumper or protrudes outward from the bumper.

After the decorative molding body 2 is held in the fixing groove 15 in the mold, the bumper body 1 is molded. 5 in the diagram
indicates a molding material such as resin that forms the bumper body 1. In this molding step, it is optional whether the decorative molding body 2 and the bumper body 1 are fixedly attached to each other or not. That is, in the normal case, the bumper body 1
The molding material 5, such as a resin forming the bumper body, and the molding body 2 have a structure in which they are integrally fixed to the bumper body at their contact surfaces due to the adhesive force of the molding material 5 when it hardens. On the other hand, the entire part of the molding body 2 that comes into contact with the molding material 5 is coated with a drug that has a mold release effect, such as paraffin wax or silicone oil, or at least the part that comes into contact with the molding material 5 is made of the same material. By taking mold release means such as forming with an incompatible substance such as polyethylene resin, polypropylene resin, polyfluoroethylene resin, etc., adhesion between the two is prevented during molding, and the molding body 2 is kept in a slidable state. It is also possible to hold. In other words, after the bumper body 1 is molded, the decorative molding body 2 is configured in a fitted state with the bumper body 1, and by configuring it in this way, the bumper body 1 is formed. Differences in dimensional changes due to differences in thermal expansion between the materials forming the molding body 2 can be absorbed by the sliding movement of the molding body 2, and also when an impact is applied to the bumper body 1, This is an extremely effective means for preventing stress concentration and preventing cracks and destruction of the molding body 2. Furthermore, remove
Replacement is also easy.

As described above, in the manufacturing method according to the present invention, the molding body is held in the fixing groove provided in the bumper mold, so that the molding material such as rubber or synthetic resin flows during bumper molding. There is no concern that the molding body will be misaligned, and since the fixing groove has a width that is the same as or slightly smaller than the width S of the decorative surface of the molding body, the side surface of the molding body can be firmly held. It is possible to prevent the resin from going around or adhering to the surface of the molding body during clamping and molding. Further, since embedded leg portions are formed on the back surface of the decorative molding body and are embedded within the bumper, the molding body can be securely attached to the bumper. As described above, according to the present invention, it is possible to easily obtain an automobile bumper equipped with a decorative molding body having a beautiful outer surface through extremely simple steps.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of an elastic bumper for an automobile equipped with a decorative molding body, Fig. 2 is a partial perspective view of the decorative molding body, and Fig. 3 is an explanation of bumper molding showing an embodiment of the present invention. 4 are explanatory diagrams of main parts of another embodiment. 1... Bumper body, 2... Decorative molding body, 3...
... Decorative surface, 4... Base layer, 5... Molding material, 6...
...Embedded leg part, 10, 11...Mold, 12, 1
2'...protrusion, 15...fixing groove.

Claims (1)

[Claims] 1. A fixing groove having a width equal to or slightly smaller than the width S of the decorative surface of the decorative molding body having a decorative surface on the front and embedded legs on the back side is provided in the mold of the elastic bumper. A decoration characterized in that, after the front part of the decorative molding body is clamped in the fixing groove, a molding material is injected into a mold to mold a bumper in which the embedded legs of the decorative molding body are integrally embedded. A method of manufacturing an elastic bumper for an automobile equipped with a molding body.