JPH0130696B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a synthetic resin pallet in which a metal core is embedded for reinforcing the synthetic resin pallet.

In recent years, synthetic resin pallets have come into use in place of wooden pallets.

However, although synthetic resin pallets have various advantages over wooden pallets, they have the disadvantage that their bending strength is lower than that of wooden pallets. Therefore, in order to improve this bending strength, a synthetic resin pallet containing a metal core (hereinafter referred to as a pallet with a metal core) was developed. What is required of a pallet with a metal core is that it be as light as possible and that the metal core not be exposed on the surface of the pallet. If the metal core is exposed on the surface of the pallet, not only will the metal core rust and become unhygienic, but if the corrosion progresses, the portion may break under the load pressure, leading to an unexpected accident.

Pallets with a metal core that have already been developed are mainly formed by foam molding, rotational molding, or in some cases, injection molding, and generally have the functions of the metal core pallet. However, it was still insufficient in the following points.

First, the first drawback is that foam molding and rotational molding are limited to pallets with simple shapes, and it is difficult to mold pallets with complex shapes that perform various functions. For example, it has not been possible to construct a pallet with multiple rib structures that have minimal material and weight without reducing strength. Although the injection molding method does not have the above drawbacks, it has the second drawback described below.

The second drawback is that the method of holding the metal core in place during molding involves using a special metal member that can be removed after molding, and then filling the space with plastic material after removing the member, or using a pallet. Methods have been adopted in which the metal core is held in place within the mold using a plastic material that is compatible with the material of the main body, but these methods require extra steps and materials, making the molding cost relatively high. There was a drawback.

The pallet according to the invention overcomes all the above-mentioned drawbacks. The present invention will be explained below with reference to the drawings.

FIG. 1 shows the appearance of a pallet according to the invention,
The pallet has an upper piece 1 and a lower piece 2 joined together at the joint surface A-A'. 3 is a fork insertion hole.

FIG. 2 shows the lower piece 2 of the pallet shown in FIG. 1 with the inside facing up. A large number of projecting frames 8, which are open only on the upper surface, and which are constructed in cooperation with the side wall 5 or the standing wall 7, and a metal core 9, which is not shown in FIG. 2 but shown in the cross-sectional views of FIGS. 3 and 4. are partially exposed 10 within the projecting frame 8 and are buried in a direction perpendicular to the fork insertion hole 3.

The upper piece 1 (not shown) is also provided with a protruding frame 8, which is similar to the protruding frame 8 of the lower piece 2 shown in FIG.
It is provided in the same shape and in a symmetrical position. The same applies to side walls, front and rear walls, vertical walls, etc.

By joining such upper piece 1 and lower piece 2 with their inner sides facing each other, a pallet as shown in FIG. 1 can be obtained.

As described above, according to the present invention, a finished product can be obtained by molding the upper and lower pieces separately and then joining them, and each piece can be molded by injection molding, foam molding, or rotational molding. However, it is determined based on the economic effect, function to be performed, and shape of each material.

The optimum method for embedding the metal core in the method of the present invention is to apply magnetic force to the male mold forming the core part of the protruding frame 8, and to attach the metal core to the tip of the mold.
This is a method of molding by strongly adsorbing. In the upper piece 1 or the lower piece 2 formed by this method, a part of the metal core 9 is exposed only in the protruding frame 8, and the other part is exposed in the lower surface 4 of the lower piece 2 or in the upper piece 1 (not shown). It is completely buried within the top surface.

Since the upper piece 1 and the lower piece 2 are formed in a symmetrical shape, if the upper piece 1 and the lower piece 2 are joined by heat fusion or, in some cases, mechanical means such as bolts,
Since the protruding frames 8 of the upper piece 1 and the protruding frames 8 of the lower piece 2 are joined with their open surfaces facing each other, the space surrounded by the upper and lower protruding frames 8 becomes a completely closed room. In this way, the metal core, which was partially exposed during the molding of the upper piece 1 and the lower piece 2, is completely isolated from the outside air in the completed pallet, and the problem of rust and hygiene is extremely effectively solved. be done.

Note that an iron pipe is effective for the metal core 9 in terms of strength, weight, and cost. In this case, both ends are capped to prevent synthetic resin from flowing into the pipe during molding.

Further, the metal core 9 may be embedded in both the upper piece and the lower piece, or may be embedded only in either the upper piece or the lower piece. However, even if the metal core is buried in only one side, the protruding frame 8 must be provided on both the upper and lower pieces.

Furthermore, although the orientation of the metal core 9 is perpendicular to the fork insertion hole 3 in the illustrated embodiment, it is not necessarily limited to this method, and may be oriented parallel to the insertion hole 3.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a pallet manufactured according to the present invention, FIG. 2 is a perspective view of a lower piece constituting the same pallet, FIG.
The figure is a sectional view taken along the same line. In the figure, 1 is the upper piece, 2 is the lower piece, 3 is the fork insertion hole, 4 is the bottom of the lower piece,
5 is a side wall, 6 is a front and rear wall, 7 is a standing wall, 8 is a protruding frame,
Reference numeral 9 indicates a metal core.

Claims (1)

[Claims] 1. In a method of manufacturing a synthetic resin pallet by joining an upper piece and a lower piece, a plurality of protruding frames with only the upper surfaces open are provided at symmetrical positions on the inside of each upper and lower piece, and the above-mentioned plurality of protruding frames are provided on the upper and lower pieces or either one of the pieces. A bar-shaped metal core is buried in an appropriate number of positions where the protruding frames are stacked linearly, with a part exposed within the protruding frames,
A method for manufacturing a synthetic resin pallet with a metal core, characterized in that the upper and lower pieces are joined together and the exposed portion of the metal piece is hermetically sealed in a closed chamber formed by two joined protruding frames.