JPH0150631B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to an engine hood, and more particularly to an engine hood made of synthetic resin and provided with electromagnetic shielding.

BACKGROUND OF THE INVENTION It is well known that in recent years, fuel efficiency has been attracting attention as an item for evaluating the performance of automobiles. Therefore, in order to improve fuel efficiency, efforts are being made to reduce the weight of vehicle bodies in addition to improving engines, etc., and as part of this effort, engine hoods are made of synthetic resin such as fiber reinforced plastic (FRP). There is. If the engine hood is made of synthetic resin, there are many sources of electrical noise in the engine room, such as electrical equipment and auxiliary motors, and synthetic resin is not conductive, so it may cause radio interference. Electromagnetic interference occurs, such as radio noise or malfunction of electronic equipment in the engine room.

Therefore, conventionally, as a countermeasure against electromagnetic interference,
The inner surface of a synthetic resin engine hood is coated with a conductive material such as aluminum foil or wire mesh, or the surface is treated with electromagnetic shielding paint.

Problems to be Solved by the Invention However, in a structure in which a conductive material such as Al foil or wire mesh is attached to the inner surface of the engine hood, the inner surface of the engine hood is an inner panel (inner plate) for reinforcement.
Since the surface is uneven due to the engine hood, the conductive material must be installed along the unevenness, otherwise a portion of the conductive material will be floating above the inner surface of the engine hood. In order to prevent the conductive material from bending significantly and breakage at the floating parts, it must be made somewhat thick. In any case, the structure on which the conductive material is attached does not have a smooth surface, which makes it look bad, and if it is thickened to prevent breakage, its weight increases, and the engine hood is made of synthetic resin. There was a problem that undermined the original purpose of the project. On the other hand, in a structure in which surface treatment is performed using electromagnetic shielding paint or the like, the treatment agent itself is expensive, and the work process becomes complicated, resulting in a problem of rising manufacturing costs.

In view of the above circumstances, this invention can reliably shield electromagnetic waves and has a good appearance.
It is an object of the present invention to provide an engine hood made of synthetic resin that is inexpensive and has no fear of increasing weight.

Means for Solving the Problems In order to achieve the above object, the present invention includes a thin conductive material such as metal foil for electromagnetic shielding, which is sandwiched between an outer panel and an inner panel made of synthetic resin. In addition, an opening is provided in the conductive material at least at a location corresponding to the adhesive portion between the outer plate and the inner plate.

Function: Therefore, in this invention, electromagnetic waves are reliably shielded by the conductive material interposed between the outer plate and the inner plate. In addition, since the conductive material is in close contact with the inner surface of the outer panel, which is almost flat, it can be extremely thin.Furthermore, the conductive material is hidden by the inner panel, so it looks good and does not particularly increase weight. Can be done without engine hood.
Furthermore, since the outer panel and the inner panel are bonded together through the openings in the conductive material, a sufficient bonding area is ensured, and the outer panel and the inner panel are reliably bonded.

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a partial cross-sectional view of an engine hood 1 according to the present invention, FIG. 2 is a plan view of the engine hood 1 showing the cross-sectional area, and FIG. 3 is a partially exploded perspective view. , the engine hood 1 shown here has an outer panel 2 made of synthetic resin with an inner surface including:
It has a structure in which an inner plate 3 also made of synthetic resin is adhered, and a thin conductive material 4 is sandwiched between the outer plate 2 and the inner plate 3. The outer panel 2 forms the exterior, and is formed into a shape based on the design of the body. The inner plate 3 is mainly used for reinforcement, and has hollow protrusions (ribs) 5 with convex cross sections formed at necessary locations according to the overall shape of the engine hood 1. A thin film 6 for concealment is formed between the two. The thickness of the thin film 6 is, for example, about 0.5 to 1.5 mm, whereas the thickness of other parts can be about 2.0 to 3.0 mm. This can be set by making it made of resin. The material for these outer panels 2 and inner panels 3 is FRP such as sheet molding compound (SMC).
In addition, various thermoplastic resins, urethanes, etc. can be used, and compression molding, injection molding, etc. can be used as the manufacturing method.

On the other hand, the conductive material 4 is for shielding electromagnetic waves, and various metal sheets or metal foils can be used. In particular, from the point of view of cost, flexibility, workability, rust resistance, etc., Al foil is suitable, and its thickness is 30~
If the thickness is about 100 μm, workability will be even better in terms of breaking strength and flexibility. Furthermore, the conductive material 4 is attached to almost the entire inner surface of the outer panel 2, whereas the inner panel 3 is partially bonded to the outer panel 2. Therefore, in order to secure the bonding area, the conductive material 4 is An opening 7 is formed in a portion corresponding to the adhesive portion between the inner plate 3 and the outer plate 2. The opening 7 may be a large number of round holes shown in FIG. 4A, a large number of long holes shown in FIG. 4B, or a large rectangular hole punched out as shown in FIG. 4C, or even a large rectangular hole shown in FIG. As shown in D, a diamond-shaped hole or the like can be adopted by using Al foil lath as the conductive material 4. In addition,
If Al foil lath is used, openings 7 will be provided throughout, and depending on the size of the mesh, the adhesion area will increase, but the shielding properties may decrease. Select a mesh of appropriate size.

And an adhesive 8 that integrates the outer panel 2 and the inner panel 3
As the adhesive, various structural adhesives such as urethane, epoxy, or acrylic are used.

Therefore, according to the above engine hood 1,
Electromagnetic waves can be reliably shielded by electrically connecting the conductive material 4 to another suitable metal plate constituting the body. Also, the conductive material 4 is the outer panel 2
Since the conductive material 4 is sandwiched between the inner plate 3 and the inner plate 3, it can be made extremely thin without degrading the electromagnetic wave shielding properties.Furthermore, the conductive material 4 is completely hidden by the thin film 6 of the inner plate, making it lightweight. It is possible to provide an engine hood with a good appearance without impairing its appearance.

Effects of the Invention As is clear from the above explanation, according to the present invention, since the conductive material is interposed between the outer plate and the inner plate, electromagnetic waves can be reliably shielded, and the conductive material can be interposed between the outer plate and the inner plate. Because it can be made extremely thin, weight reduction is not compromised, and since most of the conductive material is hidden by the inner plate, the appearance is not compromised, and especially the strength of the inner plate. If a thin film is integrally formed in areas where it is not required, not only the conductive material but also the protruding portion of the adhesive can be hidden, making it possible to improve the appearance better than ever before. Furthermore, the present invention can be manufactured at low cost since commonly used materials and processes can be used. In addition, in this invention, the apertures are provided in the conductive material to ensure the adhesion area between the outer panel and the inner panel, thereby preventing a decrease in adhesive strength due to the interposition of the conductive material between the outer panel and the inner panel. In addition, an engine hood with excellent strength can be obtained. In addition, since it is essentially point bonding, if the thickness of the outer panel is made thinner to reduce weight, sink marks (surface irregularities) may occur on the bonding surface of the outer panel due to curing and shrinkage of the adhesive. This can be effectively prevented from occurring.

[Brief explanation of drawings]

FIG. 1 is a partial cross-sectional view showing one embodiment of the present invention, FIG.
FIGS. 4A to 4D are exploded perspective views of the parts shown in the figure, and partial plan views showing examples of the shapes of the openings in the inner plate, respectively. DESCRIPTION OF SYMBOLS 1... Engine hood, 2... Outer plate, 3... Inner plate, 4... Conductive material, 7... Opening part, 8... Adhesive.

Claims (1)

[Claims] 1. A thin conductive material for electromagnetic wave shielding is interposed between the synthetic resin outer panel and the synthetic resin inner panel, and at least a portion of the conductive material corresponding to the bonded portion between the outer panel and the inner panel is provided. A synthetic resin engine hood characterized by being provided with an opening for securing an adhesive area.