JPH0336700B2 - - Google Patents

Description

[Detailed Description of the Invention] <<Field of the Invention>> The present invention relates to a reinforcing structure for automobile interior materials, and particularly to a structure for preventing deformation and protrusion of beam ends due to resin shrinkage during press molding of interior materials. .

≪Prior art and its problems≫ In interior materials that need to have sufficient resistance in the direction of loading, such as rear parcels for automobiles, one or more reinforcing layers are installed along the width direction on the back side of the interior material. The beams are integrated.

In addition, if the main body of the rear parcel is made of synthetic resin such as polypropylene composite resin, one way to integrate it is to place a resin material of the same or different material as the board material at the bottom of the beam. By applying pressure through cold press molding, the resin material and the main body portion are integrally joined to surround the outer periphery of the beam. This eliminates the deterioration in appearance caused by beams being exposed on the back surface when the rear parcel is opened.

However, with this structure, resin shrinkage during press molding causes the main body of the rear parcel to be distorted or both ends of the beams to break through the resin material, causing a decrease in yield.

<<Object of the Invention>> The object of the present invention is to prevent distortion or protrusion of beams during press molding or after press molding in interior materials as described above, and to improve yield.

<<Structure and Effects of the Invention>> In order to achieve the above object, the present invention divides a reinforcing beam into three in the longitudinal direction, and slidably fits the left and right reinforcing pieces to the joint ends of the central reinforcing piece. It is characterized by a combination of

According to the above structure, when the resin contracts during press molding or after press molding, the left and right reinforcing pieces resist the internal stress and slide into the center reinforcing piece, causing the molded product to shrink. Since flatness is maintained and at the same time the ends of the beams do not break through the resin material, the appearance of the product is not impaired and the product yield can be improved.

<<Example>> Fig. 1 shows a beam to which the present invention is applied, and Fig. 2 shows a cross section of a rear parcel in which the beam is integrated.

In the figure, the beam consists of a central reinforcing piece 1 and left and right reinforcing pieces 2, 2.

The central reinforcing piece 1 is a hollow rigid body having a substantially trapezoidal cross section. The left and right reinforcing pieces 2 are hollow rigid bodies having similar shapes, and one end portion 2a of the left and right reinforcing pieces 2 is flattened.

Further, the joining ends 2b of the left and right reinforcing pieces 2 are fitted into openings 1a at both ends formed in the center piece 1.

Although this fitting margin differs depending on the heat shrinkage that occurs during molding of the rear parcel, the left and right reinforcing pieces 2 have a sufficient fitting margin with respect to the central reinforcing piece 1, and are in a tight fit state. This provides sufficient resistance against loading.

Each reinforcing piece 1, 2 is attached to the rear parcel body 3.
The outer periphery is completely surrounded by a resin material 4 made of the same material as the main body 3, and the resin material 4 and the main body 3 side are heat-fused during press molding. As they wear clothes, they become integrated.

Figures 3a and 3b show the order of forming the rear parcel constructed as described above. First, the rear parcel is heated,
The resin material 4 in a semi-molten state was placed in the groove 10a formed on the lower mold 10 into which each reinforcing piece was inserted, and the joined reinforcing pieces 1 and 2 were placed in the groove 10a, and the resin material 4 was also heated and plasticized. A resin board 3' constituting the rear parcel body 3 is placed on the lower mold 10.

Next, when the upper mold 11 is engaged with the lower mold 10 and sufficient pressure is applied, the thermoplasticized resin board 3' and the resin material 4 surround each of the reinforcing pieces 1 and 2. The joined ends are fused together and integrated.

Next, after cooling, the upper mold 11 is raised and the rear parcel is removed from the lower mold 10 to obtain a rear parcel in which the reinforcing pieces 1 and 2 shown in FIG. 2 are integrated.

During the molding process or after molding, the resin cooled in the mold contracts in the direction shown by the arrow in FIG. 2 due to resin contraction accompanying the cooling.

This stress causes the left and right reinforcing pieces 2 to enter into the center reinforcing piece 1, so that the ends 2a of the left and right reinforcing pieces do not break through the surrounding area of the resin material, and the left and right reinforcing pieces 2, the fitting margin for the central reinforcing piece 1 increases, and as the fitting margin increases, each reinforcing piece 1 and 2 self-correct so that they are on the same straight line.

Therefore, the internal stress caused by resin contraction after or during molding does not act as a force that bends the reinforcing piece, but acts as an action to straighten the reinforcing piece.

[Brief explanation of the drawing]

Figure 1 is a perspective view of a beam to which this invention is applied, Figure 2 is a perspective view of a beam to which this invention is applied;
The figure is a partial perspective view showing a rear parcel in which the beams are integrated, and FIGS. 3a and 3b are explanatory diagrams showing the order of forming the rear parcel. 1...Central reinforcement piece, 2...Right and left reinforcement pieces, 3...
Rear parcel body, 4...resin material.

Claims (1)

[Claims] 1. An automobile interior material in which a reinforcing beam is arranged on the back side of a synthetic resin board material, and the outer periphery of the beam is surrounded by a resin material and press-formed as one body, and the beam is formed in a longitudinal direction. 1. A reinforcing structure for an automobile interior material, which is divided into three parts, and left and right reinforcing pieces are slidably fitted to the joining ends of the central reinforcing piece.