JPS6233705Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a synthetic resin pallet. More specifically, the present invention relates to an improvement in a synthetic resin pallet in which pallet forming members constituting a part of the pallet are welded to each other to be integrated.

Conventionally, this type of synthetic resin pallet was
It is molded in one step using a method such as injection molding (for example, U.S. Patent No. 3,603,272), or it is molded by dividing the pallet into a plurality of pallet forming members, which are then mechanically connected using bolts and nuts. things (for example, West German Published Patent Specification No. 1756384,
(U.S. Pat. No. 3,667,403), those bonded with an adhesive (for example, Japanese Patent Publication No. 46-39529), and those assembled and integrated by heat welding (for example, Japanese Patent Publication No. 53-18776).

However, the method of molding in one step as described above (for example, US Patent Specification No.
No. 3603272) requires a large injection molding machine, etc., and also requires a mold with a slide core. For example, West German Published Patent Specification No. 1756384, U.S. Patent Specification No.
No. 3667403), etc., when the pallet is bent during use, stress concentrates on the parts connected by bolts and nuts, which causes strength problems. Also, those assembled by bonding with adhesive (for example,
No.) has the problem that the strength of the joint is weak.

Assuming that the above problems do not occur,
As shown in FIG. 9, a synthetic resin pallet 10 is
There is one in which the upper and lower pallet forming members 10a and 10b, which are horizontally divided, are assembled and integrated by heat welding (for example, Japanese Patent Publication No. 53-18776), and according to this, the molding machine and mold can be made smaller. The structure is simple, stress is not concentrated in a part of the joint during use, and the strength of the joint is good. On the other hand, synthetic resin molded products shrink after molding, and the pallet forming members 10a,
10b, the deck board 14 in particular has large shrinkage values in the width and length directions, and there are differences in shrinkage for each molded product, so if welded without any correction, the welding positions of the pallet forming members 10a and 10b will shift and the welded part will be There are problems such as reduced strength and impossibility of assembly.

The pallet of the present invention belongs to the above-mentioned pallet in which a plurality of pallet forming members are assembled and integrated by heat welding, but the pallet of the above-mentioned Japanese Patent Publication Showa
The pallet is not divided only in the horizontal direction as disclosed in No. It cannot be said that these technologies can be compared.

The inventors of the present invention have conducted intensive studies with the aim of obtaining a pallet that avoids the problems of the aforementioned pallets that are assembled by heat welding, such as a decrease in strength due to misalignment of the welding position and the impossibility of assembling. The present invention solves the problem by assembling pallet forming members that are divided approximately at the vertical and horizontal centers of the planar shape of the pallet by heat welding, and providing an extension at the welded portion of the pallet forming members. completed.

That is, the gist of the present invention is that the pallet is formed by forming a pallet forming member that is divided approximately at the center in the vertical and horizontal directions of the planar shape of the pallet, and by welding the welded parts located on the sides of the pallet forming member. The present invention relates to a synthetic resin pallet characterized in that an extending portion is provided at a welded portion of the pallet forming member.

The synthetic resins used to form the synthetic resin pallets of the present invention include olefinic resins such as polyethylene, polypropylene, ethylene-propylene copolymer, polybutene-1, ethylene-vinyl acetate copolymer, polystyrene, and styrene-acrylonitrile. Copolymers, styrene resins such as acrylonitrile-butadiene-styrene terpolymer, polyvinyl chloride, polyvinylidene chloride, vinyl chloride resins such as vinyl chloride-vinyl acetate copolymer, nylon 6, nylon 6-6 , nylon 6-
10, ordinary thermoplastic synthetic resins such as polyamide resins such as nylon-11 and nylon-12,
These thermoplastic synthetic resins may be used alone or in combination.

In addition, additives such as antioxidants, ultraviolet absorbers, heat stabilizers, antistatic agents, flame retardants, blowing agents, dyes, pigments, organic fillers, and inorganic fillers are added to these thermoplastic synthetic resins. Of course, it is okay to do so.

An example of the synthetic resin pallet of the present invention will be described below with reference to the drawings, but the present invention is not limited to the following description unless it exceeds the gist thereof.

Fig. 1 is a perspective view showing an example of the pallet of the present invention, Fig. 2 A, B, and C are respectively a plan view, a front view, and a side view of the pallet shown in Fig. 1, and Fig. 3 is the same as Fig. 1. The back view of the pallet shown in FIG. 4 is a sectional view taken along the line A-A in FIG. 7 is a perspective view of an example of a pallet forming member used when constructing a four-way pallet according to the invention; FIG. 7A is a plan view of the pallet forming member shown in FIG. 6; FIG. 7B is a front view; and FIG. 8A is a sectional view taken along the line DD in FIG. 7A, and FIG. 8B is a sectional view taken along the line E-E in FIG. 7B.

In the figure, 1 is a synthetic resin pallet, 1a to 1d are pallet forming members, 2 is a welded part, 3 is an extension part, 4 is a deck board, 5 is a girder, 6 is a rib, and 7 is a fork insertion hole. .

The synthetic resin pallet 1 of the present invention is formed by welding pallet forming members 1a to 1d that are divided approximately at the longitudinal and lateral center of the planar shape.

1c located in a symmetrical position to the pallet forming member 1a
have the same shape, and the pallet forming members 1b and 1d
The same is true.

The pallet forming members 1a to 1d are welded together at opposing sides. This part is called the welded part 2. The shapes of the side portions of the pallet forming members located in the welded portion 2 are the same shape or substantially the same shape.

The welding in the welded parts 2 is carried out, for example, by pressing the welded parts 2 of the pallet forming members 1a to 1d facing each other against a heating plate that has a built-in electric heater or the like and is in a heated state, thereby melting the pallet forming members in a molten state. This is done by so-called butt welding in which the side parts 1a to 1d are pressed against each other to face each other. In addition to this butt welding, hot air welding can also be performed, in which hot air is blown to melt the welding part and the welding rod, and the welding rod is embedded and welded, but the welding efficiency is
Butt welding is preferably used in terms of efficiency.

Further, the welding order of the pallet forming members 1a to 1d is not particularly limited, and for example, the welding order of the pallet forming members 1a to 1d is
A method of welding and integrating all a to 1d at once, 1
Welding of a and 1d or 1d and 1c and 1d or 1
A method is adopted in which the welding step b is performed and then the two welded parts are welded together.

The synthetic resin pallet 1 of the present invention is integrated by welding as described above, but the pallet forming members 1a to 1 are
In order to increase the welding area of the welding part 2, an extension part 3 is provided in the welding part 2 where the welding of d is performed.

The extending portion 3 includes deck boards 4, girders 5, and ribs 6 that form the welded portions 2 of the pallet forming members 1a to 1d.
It is provided on the side of the deck board 4, girder 5, rib 6, etc., and is provided so as to protrude substantially perpendicularly to the deck board 4, girder 5, rib 6, etc. That is, deck board 4, digit 5,
The rib 6 and the like and the extending portion 3 form a substantially L-shape or a substantially T-shape in cross-section (the fourth
(see figure).

When provided on the deck board 4, the extending portion 3 is provided so as to protrude inward from the pallet 1, and when provided on the girder 5, rib 6, etc., it is provided so as to protrude laterally. It is desirable that the extension part 3 is provided so as to extend toward the outer surface of the synthetic resin pallet 1 or the inside of the fork insertion hole 7, so that cargo or forks such as a forklift can be easily removed. Since there is a risk that the extending portion 3 may be destroyed by contact, it is important to select the location where the extending portion 3 is provided depending on the structure of the pallet.

Furthermore, it is more effective to provide the extending portions 3 on the beams 5 and ribs 6 provided perpendicularly to the deck board 4 rather than on the deck board 4. This is because the pallet forming members 1a to 1d have a planar shape.
The difference in shrinkage when molding d by injection molding etc.
This is because since it appears largely in the lateral direction, when the pallet forming members 1a to 1d are butted against each other, there is a large deviation in the lateral direction. If the extending portions 3 are provided on the beams 5 and the ribs 6, poor welding between the pallet forming members 1a to 1d will not occur.

Furthermore, the extending portions 3 provided on the girders 5 and ribs 6 are
This is also preferable because it is a direction suitable for reinforcing the welded portion 2 against the bending stress that the pallet receives when the pallet is used with cargo placed thereon.

As mentioned above, the extension part 3 is provided in the weld part 2, and its size is the area of the weld part 2 when the extension part 3 of the pallet forming members 1a to 1d is not provided. It is desirable to set it so that it is 1.2 times or more. The area of welded part 2 is the same as the original area.
If it is less than 1.2 times, it is not possible to prevent welding defects due to misalignment of the welded portion or to improve the strength of the welded portion 2.

Note that the upper limit of the size of the extending portion 3 is such that it extends over the entire side portion of the pallet forming members 1a to 1d, excluding locations where holes such as the fork insertion holes 7 are required to be opened.

In addition, the thickness of the extension part 3 is the thickness of the deck board 4, the girder 5,
The thickness may be about 1/2 of the thickness of the ribs 6, etc., but it is usually desirable to have a thickness about the same as these.

In any case, the location, size, thickness, etc. of the extending portion 3 will depend on the required strength of the pallet to be obtained.
It is determined by considering the difference in shrinkage of the pallet forming members 1a to 1d.

Although FIGS. 1 to 5 illustrate a two-way pallet and FIGS. 6 to 8 illustrate a four-way pallet, the structure of the extending portion 3 is the same.

Further, the palette of the present invention is, for example, shown in Figs.
In addition to the one divided approximately at the center in the vertical and horizontal directions in the plane shape shown in Fig. 8, the pallet forming member (divided into eight pieces) is further divided in the horizontal direction (divided into upper and lower parts). It may also be made up of divided pallet forming members).

When welding these eight divided pallet forming members, the horizontal welding portion may or may not be provided with an extending portion. This is because the horizontal welds are substantially perpendicular to the direction of bending stress applied when the pallet is used, so it is thought that the influence of stress is small.

In this way, the synthetic resin pallet of the present invention is
Since the molding is performed by dividing into a plurality of pallet forming members, the molding machine can be small and it is very economical.

In addition, since the extension part is provided in the welding part, the welding area increases, which is very favorable for the strength of the pallet, and since the welding is carried out approximately in the vertical and horizontal center of the planar shape of the pallet, for example, Even if the pallet forming parts shrink or deform to some extent, the dimensions can be regulated during welding, making it possible to efficiently manufacture homogeneous synthetic resin pallets with good dimensional accuracy. be effective. In addition, it has the unique effect of preventing a decrease in the strength of the pallet due to misalignment of the welded parts between the pallet forming members.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing an example of the pallet of the present invention, Fig. 2 A, B, and C are respectively a plan view, a front view, and a side view of the pallet shown in Fig. 1, and Fig. 3 is the same as Fig. 1. The back view of the pallet shown in FIG. 4 is a sectional view taken along the line A-A in FIG. 7 is a perspective view of an example of a pallet forming member used when constructing a four-way pallet according to the invention; FIG. 7A is a plan view of the pallet forming member shown in FIG. 6; FIG. 7B is a front view; and FIG. 8A is a sectional view taken along the line DD in FIG. 7A, and FIG. 8B is a sectional view taken along the line E-E in FIG. 7B. Further, FIG. 9 is a perspective view showing an example of the structure of a conventional pallet. In the figure, 1 is a synthetic resin pallet, 1a to 1d are pallet forming members, 2 is a welded part, 3 is an extension part, 4 is a deck board, 5 is a girder, 6 is a rib, and 7 is a fork insertion hole.

Claims (1)

[Claims for Utility Model Registration] (1) Consisting of a pallet forming member divided approximately at the vertical and horizontal center of the planar shape of the pallet, the welded portions located on the sides of the pallet forming member being welded together. 1. A pallet made of synthetic resin, characterized in that an extending portion is provided at a welded portion of the pallet forming member. (2) The synthetic resin pallet according to claim 1, wherein the welded portion has a substantially L-shaped cross-section. (3) The synthetic resin pallet according to claim 1 of the utility model registration claim, wherein the cross-sectional shape of the welded portion is approximately T-shaped.