JPS589867Y2 - Synthetic resin pallet - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a synthetic resin pallet used to load articles and insert a fork such as a forklift for transportation, movement, storage, etc.

Conventionally, this type of pallet usually has two upper and lower deck boards, and parallel girders are provided at both end edges and the middle of each of the deck boards, and a fork for inserting a fork into the space between the girders. It is said to have a hole-shaped structure.

In general, methods for manufacturing such pallets using synthetic resin include, for example, manufacturing the pallet in one step using injection molding, or molding each part of the pallet, such as the deck board and girder, separately and then molding the pallet separately. It is assembled using bolts, nuts, or other appropriate coupling tools, or by bonding with an adhesive or melting.

However, when manufacturing pallets using synthetic resin, even if the pallet is made in one process or each part is made separately and assembled, it is not possible to avoid the constraints of molding synthetic resin. First, this appeared to be a constraint on the shape and structure of synthetic resin pallets.

In other words, regarding these constraints, injection molding is often used as a molding method generally used when manufacturing synthetic resin pallets, but this injection molding does not fit the desired shape into a metal mold (mold). In this method, a molten synthetic resin is introduced into the space, cooled, and then the mold is opened and the molded product is taken out to obtain the product.

In this injection molding, when opening the mold and taking out the molded product, the molded product must have a certain level of strength because it is in close contact with the mold. The thickness must be greater than a certain level.

Therefore, synthetic resin pallets have the disadvantage that some parts have a wall thickness greater than the required strength and breakage, making the synthetic resin used as a raw material uneconomical.

In particular, when this synthetic resin pallet is molded into parts and later assembled by welding, the welded parts may shift slightly, and the wall thickness must be increased to take into account poor welding due to this shift. , this drawback was noticeable.

This invention was made in order to eliminate the above-mentioned drawbacks, and by making the beams of the synthetic resin pallet have a special structure, it is possible to reduce the weight without reducing the strength.

This idea will be explained below.

Figures 1 to 3 show an embodiment of this invention. Figure 1 is a perspective view of a two-way synthetic resin pallet, Figure 2 is a perspective view of the lower pallet forming member, and Figure 3 is a perspective view of a two-way synthetic resin pallet. FIG. 2 is a side view showing the shape of a hole in the side surface of the girder.

In these figures, 1 is a synthetic resin pallet (hereinafter referred to as a pallet), 1a is an upper pallet forming member, 1b is a lower pallet forming member, 2 is an upper deck board, 2' is a lower deck board, and 3 is the upper and lower part. Girders 3a and 3b are girder forming members of the upper and lower pallet forming members 1a and 1b, and 4 is a circular or elliptical girder provided parallel to each other at both end edges and the middle part of the deck boards 2 and 21. Hole 5 is a fork insertion port.

The pallet 1 has upper and lower pallet forming members 1a and 1.
b is integrally formed by welding the upper and lower opposing surfaces of the respective girder forming members 3a and 3b to each other.

When welding the pallet forming members 1a, 1b, if the pallet forming members 1a, 1b are not properly aligned, the welded portions will shift, the welded area will decrease, and the strength of the pallet 1 will decrease.

There is no need to worry about this if the positioning can be done perfectly, but if the synthetic resin molded product, that is, the pallet forming member 1a,
lb has a large shrinkage after molding, and for large objects like pallet 1, the dimensions usually differ slightly depending on the molded product.

Therefore, in order to absorb the deviation of the welded part caused by this dimensional difference and achieve good welding, the thickness of the girder forming members 3a and 3b that will become the welded part must be made thicker than the strength required for the girder 3 of the pallet 1. This also increases the amount of material used and the weight.

Therefore, in order to reduce the amount of materials used and the weight, round holes 4 are provided at specific positions in the girder 3.

The holes 4 are provided at positions where welding can be performed satisfactorily without reducing the strength of the pallet, and where the amount of material used can be reduced by a large amount.

This position is the center line N in the height direction of the girder of the pallet 1, that is, the height H of the pallet 1 as shown in FIG.
From the thickness dl of the upper and lower deck boards 2゜2',
1/2 of the height h of digit 3 minus d2 (d1=d2)
This is the position where a circular hole 4 having its center on the center line N or an oval hole 4 having both focal points is located.

If the shapes and structures of the upper and lower pallet forming members 1a and 1b are the same as shown in FIG. 1 and FIG. Both coincide with the so-called neutral axis (the neutral axis is calculated by calculating the position where the stress is zero based on the formula for a beam supported at two points), where the bending stress of the button when pallet 1 is used is zero. Therefore, there is no difference in the strength of the pallet 1, and the pallet forming members 1 a t 1 b
It is easy and preferable to form the hole 4 therein.

FIG. 4 shows another embodiment of this invention, in which the pallet 1 has upper and lower pallet molding members 1a and 1.
It is a nail surface view when the shape of b is different.

Referring to FIG. 4, a hole 4 is provided on the side where the fork insertion port 5 is provided, that is, on the side surface of the girder 3 facing the pallet 1 placement.

In this case as well, the position where the hole 4 is provided is at the height H of the pallet 1.
From the thickness dl of the upper deck board 2, 2'.

This is the position where the circular or bifocal-shaped oval hole 4 having its center is on the center line N of 1/2 of the height h of the girder 3 after subtracting d 2 (d 14ci 2 ).

The folded pallet 1 shown in FIG. 4 has the welded portion obliquely with respect to the center line N, which is preferable because it increases the area of the welded portion.

FIG. 5 is a partially enlarged perspective view showing still another embodiment of this invention in which the central axis N of the four-way pallet 1, which is attached to the claw surface and the center axis N of the button in the height direction of the side girder 3, is different for each surface. It is.

As shown in Fig. 5, the centers of the holes 4 are positioned on the respective central axes N, and since the welded parts are shifted between the surface and the side of the pallet 1, the welded parts at the corners of the pallet 1 are centered. It should be provided obliquely to the axis N.

In addition, damage to pallet 1 due to external impact, etc.
When used in a place where there is a high possibility of ingress of dirt, water, etc., the holes 4 may be provided on the side of the girder 3 inside the pallet 1, as shown in FIG.

It should be noted that the total area of the holes 4 should be set within the range of 10 to 60 times the total area of the girder 3, preferably within the range of tL<U15 to 35%, and if the total area of the holes 4 exceeds the above range, The area of the girder 3 decreases and the strength of the pallet 1 decreases, and below the above range, the effect of reducing the weight of the pallet 1 is small.

Next, all thermoplastic synthetic resins are used as the synthetic resin for manufacturing the pallet 1 of this invention.

Examples include polyethylene, polypropylene, polyolefin resins such as engineered styrene-propylene copolymers, polystyrene, acrylonitrile-styrene copolymers, acrylonitrile-styrene-butadiene terpolymers, polyvinyl chloride, and the like.

These synthetic resins may be used for manufacturing the lower pallet forming members 1a and Ib, but as a composition in which a known blowing agent such as a volatile blowing agent or a pyrolytic blowing agent is kneaded with the synthetic resin, It can also be used to manufacture upper and lower pallet forming members 1a and Ib.

Upper and lower pallet forming member 1 manufactured from this composition
A and 1b are foams with a low magnification, and the surface layer is non-foamed, which is preferable from the viewpoint of both the weight and strength of the pallet 1.

Additionally, commonly used additives such as fillers, pigments, and plasticizers can be added to the synthetic resin, if necessary.

As explained above, according to this invention, by making an appropriate number of holes on the side of the girder of the pallet, the pallet can be made lightweight, and when used in a cold storage warehouse, air circulation during storage can be reduced. It has various advantages, such as the holes can be used as hand holes to easily move the pallet, and the materials used can be saved, so it can be used for receiving pictures.

Furthermore, although the pallet of this invention has a structure in which the upper and lower pallet forming members are welded together as described above, it is of course not limited to this structure, and may be molded integrally by injection molding. The present invention can be applied to pallets that have a structure in which each member is manufactured individually and then assembled into one body by welding or mechanical bonding.

[Brief explanation of drawings]

Figures 1 to 3 show an embodiment of this invention. Figure 1 is a perspective view of a two-way synthetic resin pallet, Figure 2 is a perspective view of the lower pallet forming member, and Figure 3 is a perspective view of a two-way synthetic resin pallet. Figure 4 is a side view showing the shape of a hole in the side of the girder, Figure 4 is a side view showing another embodiment of this invention, and Figure 5 is a composite of a four-way insert showing still another embodiment of this invention. It is a partial perspective view of a resin pallet. In the figure, 1 is a pallet), 1a and 1b are upper button and lower pallet forming members, 2 and 2' are upper and lower deck boards, 3 is a girder, 3a and 3b are girder forming members, 4 is a hole, and 5 is a fork difference. Entrance, N is the center line.

Claims (1)

[Scope of utility model registration request] Facing a synthetic resin pallet consisting of two upper and lower deck boards and girders provided parallel to each other at both end edges and the middle of each of the deck boards, insert the girder in the height direction of the girder. A synthetic resin pallet characterized by having a circular hole with its center on the center line or an oval hole with both focal points.