JPS589868Y2 - Synthetic resin pallet - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a synthetic resin pallet for a forklift used when transporting, moving, and storing articles.

Traditionally, wood has been commonly used as the material for pallets for forklifts, but due to the shortage of wood resources, the supply has not been stable. Pallets made of recycled wood have drawbacks such as poor chemical resistance and complicated manufacturing.

! There are also metal pallets, but they are expensive, so recently plastic pallets have been tried.

However, as is well known, a pallet for a forklift usually has a structure in which two deck boards are joined at both side edges and in the middle with parallel girders, and forks are installed in the spaces between the girders. Due to the nature of the synthetic resin, the bending strength of the deck board on synthetic resin pallets is lower than that of conventional wooden or metal pallets, so it is difficult to insert the fork of a forklift into the synthetic resin pallet. During transportation or movement, the pallet bends significantly, causing the load to collapse.

In addition, as mentioned above, pallets for forklifts are hollow bodies with fork insertion ports, so when molding thermoplastic synthetic resin in one step, for example by injection molding, it is necessary to use a metal plate with a slide core. Requires a mold.

In the past, this mold was huge, and a huge injection molding machine was required for molding, and the pallets manufactured in this way were extremely expensive due to the initial cost and maintenance cost of the molding machine.

Furthermore, the above-mentioned drawbacks cannot be overcome by methods such as compression molding and extrusion molding, and it is difficult to obtain synthetic resin pallets with bending strength comparable to wooden or metal pallets.

This idea was developed in consideration of the above points, and is a forklift pallet made of thermoplastic synthetic resin that can be easily molded at low cost using various conventional molding methods, and has extremely high structural strength. It provides:

This idea will be explained below.

Fig. 1 is a plan view showing one embodiment of this invention, Fig. 2 is a partially sectional side view taken along line A-A in Fig. 1, and Fig. 3 is a plan view showing an embodiment of the invention.
It is a partially sectional front view taken along the line BB in the figure.

In these figures, 1 is a pallet, 1a and Ib are pallet forming members, 2 is a deck board, 3 is a girder, 4 is a vertical rib, 5 is a flat plate part, and 6 is a substantially waveform consisting of the vertical ribs 4 and the flat plate part 5. Section I is a reinforcing vertical rib.

Next, in FIG. 4, the pallet forming member 1a is moved to the girder forming member 3'.
Figure 5 is a partial bottom view seen from the welded part side of Figure 4.
FIG. 6 is a partially sectional side view taken along line C, and FIG. 6 is a front view of FIG. 4.

The pallet 1 shown in FIG. 1 consists of two upper and lower pallet forming members 1a and Ib, and has fork insertion holes on two opposing sides.

The pallet forming members 1a, lb are formed by a deck board 2 and a girder forming member 3' integrally provided on the deck board 2.

The deck board 2 has a plurality of vertical ribs 4 and above the vertical ribs 4,
It has a substantially corrugated portion 6 formed by flat plate portions 5 which are alternately connected at the bottom.

The substantially corrugated portion 6 is provided at least near the end of the fork insertion hole of the pallet 1, and the vertical ribs 4 of the substantially corrugated portion 6 are oriented in a direction that intersects the fork insertion direction.

In the case of a two-way pallet 1 as shown in FIG. 1, the entire surface of the deck board 2 may be made into such a substantially corrugated portion 6, or only the vicinity of the end of the fork insertion hole may be provided with this substantially corrugated portion 6. Of course, the other parts may have any other structure.

Next, the ribs that make up the deck board 2 will be described.

Ribs have various cross-sectional shapes, such as 1-shaped, machined, and ■-shaped.
(However, in the case of non-foamed molded products, the maximum
ran ), ■ When the moment of inertia of each rib is compared under these constant conditions, where the rib height is constant, the one with a ■ shape is the largest.

However, the ■-shaped rib cannot be used because the cross-sectional shape of the rib forming the deck board 2 is similar to that of a molded upper plate.

For this reason, a substantially corrugated portion 6 is formed in a part of the deck board 2 in order to have a simple structure and to have a moment of inertia comparable to that of a rib having an I-shaped cross section.

In other words, this is because when the moment of inertia of area is large, the deflection against load is small.

In the substantially corrugated portion 6, the wall thickness of the vertical ribs 4 constituting the substantially corrugated portion 6 is 3 to 6 rrrrrL1, and the pitch between the center lines of the vertical ribs 4 is 10 m or 3 times the height of the vertical ribs! The height of the vertical rib 4 is preferably 15rrrIn or twice the height of the vertical rib 4.

The height of the vertical rib 4 is approximately 15 to 60 m.

Further, the thickness of the flat plate portion 5 constituting the substantially corrugated portion 6 is 4 to 7 r.
rarL, which is usually at least 1 thicker than the wall thickness of the vertical rib 4.
rn! It is configured to be n thick.

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 ethylene-zoropylene copolymers, polystyrene, acrylonitrile-styrene copolymers, acrylonitrile-styrene-butadiene terpolymers, polyvinyl chloride, and the like.

These synthetic resins are used for the 11 pallet forming members Ia,
1b, or a composition obtained by kneading a known blowing agent such as a volatile blowing agent or a pyrolytic blowing agent may be used for producing the pallet forming members 1a and 1b.

Pallet forming members 1a, 1b manufactured from this composition
is a foam with a low magnification, and the surface layer is a non-foamed layer, which is preferable from the viewpoint of both the weight and strength of the pallet 1.

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

Next, in order to manufacture the pallet 1 of this invention, the pallet forming members 1a and 1b are made of the above-mentioned thermoplastic synthetic resin using an ordinary mold and by a commonly used molding method such as injection molding or cast molding. are manufactured separately.

Since the opposing surfaces of the girder forming members 3' of the pallet forming members 1a and 1b obtained in this way have the same shape, they are welded to each other over the entire surface, and the pallet forming members 1a and 1b
complete.

The most common method for welding the pallet forming members 1a and 1b is to weld them by bringing the welding surfaces of the girder forming members 3' of the pallet forming members 1a, b and 1b into contact with the surface of a heating plate, respectively. melt the surface,
Next, the heating plate is removed, and the welding surfaces of the spar forming members 3' of the pallet forming member 1a and the welding surfaces of the spar forming members 3' of the pallet forming member 1b, which are in a molten state, are crimped and then cooled.

As the heating plate, a metal plate coated with Teflon is used, for example, and is maintained at a temperature higher than the melting point of the materials forming the pallet forming members 1a, 1b.

Next, FIG. 7 shows when the girder 3 of the pallet 1 is constructed by welding the girder forming members 3' of the pallet forming members 1a and 1b, and the welding protrudes from the surface of the girder 3. .

The pallet forming members 1a, 1b are made so that the protruding parts do not protrude further outward from the outer surface position of the girder 3.
It is preferable to provide a stepped portion 3a on the outer surface of the girder joint on the outer periphery of the spar, and in this way, the work of removing this burr can be omitted.

Next, FIG. 8 shows a cross section of an example of the substantially corrugated portion 6 constituting the deck board 2 of the pallet 1. As shown in FIG.

The substantially corrugated portion 6 is composed of a vertical rib 4 and a flat plate portion 5, and the vertical rib 4 is provided near the end of the fork insertion hole of the pallet 1 in a direction perpendicular to the fork insertion direction.

In addition, the vertical ribs 4 of the substantially corrugated portion 6 shown in FIG. Horizontal openings may be provided in the ribs 4 and the reinforcing vertical ribs I.

Furthermore, the vertical ribs 4 shown in FIG. 8 have a trapezoidal cross-sectional shape, with the upper wall thickness being thinner and the lower wall thickness being thicker, which is a preferable structure for improving the creep resistance characteristics of the pallet 1. It is.

The wall thickness is made thicker on the tensile stress side and thinner on the compressive stress side.

Buttons and T indicate reinforcing vertical ribs of the vertical ribs 4 of the substantially corrugated portion 6.

Next, an example of a case where the pallet according to this invention is constructed in a four-way configuration will be explained.

FIG. 9 is a plan view showing an example of a four-sided pallet according to this invention, FIG. 10 is a sectional front view taken along line D-D in FIG. 9, and FIG. 11 is a front view taken along line E-E in FIG. 9. Fig. 12 is a front view of the FF section in Fig. 10 (the left half is omitted because it is symmetrical with the right half) Fig. 13 is a side view of the GG section in Fig. 12, and Fig. 14 is a cross-sectional side view of Fig. 12. It is a HH cross-sectional side view.

Note that the reference numerals in the figures indicate the same parts as in FIGS. 1 to 8.

This four-sided pallet 1 consists of an upper hexagram and a lower pallet forming member 1a, 1b, and each side is provided with a fork insertion hole.

The upper button and lower pallet forming members 1a and 1b are the deck board 2 and the girder forming members 3 integrally provided at the four corners of the deck board 2, the middle part of the peripheral part, and the center part, respectively.
It is formed from '.

In addition, the deck boards 2, 2 of the upper and lower pallet forming members 1a, Ib are formed by a plurality of continuous substantially corrugated portions 6, which are interspersed with girder forming members 3/, 3/, . . . The reinforcing vertical ribs 7 are integrally arranged in parallel in a direction perpendicular to the approximately corrugated portion 6 and formed in a circular shape.

In addition, inside each of the four rectangular parts that are buttoned in the space of the table-shaped part of the deck board 2 of the upper pallet forming member 1a, a plurality of reinforcing vertical bars 7''7 are arranged in succession from two directions. .

In other words, in the part of the pallet 1 into which the fork is inserted, the vertical rib 4 is provided in the fork insertion direction in the part where the fork is inserted only in either the vertical or horizontal direction. The part into which the fork is inserted has a structure in which reinforcing vertical lips I are provided vertically and horizontally.

Therefore, no matter which direction the fork is inserted, the cross-sectional shapes of the substantially corrugated portions 6 are evenly distributed, so that there is no difference in strength and deflection.

As for the button on the lower pallet forming member 1b, each of the four rectangular portions in the table-shaped portion of the deck board 2 has hollow holes inside.

As explained above, this invention has a structure with a large moment of inertia because the deck board of the pallet, which serves as the loading surface for cargo, has a substantially corrugated section. Since they are provided continuously in the direction perpendicular to the direction in which the forks are inserted into the pallet (approximately perpendicular to the direction in which the pallet is inserted), they are strong enough to withstand the load of the loaded object and have less deflection, and the number of lips is also lower than that of conventional ones. can be reduced compared to .

Therefore, the pallet has less deflection when transporting and transporting cargo, has excellent impact resistance, water resistance, and chemical resistance, and is easier to manufacture than ■-shaped ribs, making it lighter and cheaper to manufacture. It has various advantages.

[Brief explanation of drawings]

Fig. 1 is a plan view showing one embodiment of this invention, Fig. 2 is a partially sectional side view taken along line A-A in Fig. 1, and Fig. 3 is a plan view showing an embodiment of the invention.
4 is a partial bottom view of the pallet forming member seen from the welded part side of the girder forming member; FIG. 5 is a partial cross-sectional front view taken along line B-B in the figure; FIG. 5 is a partial cross-sectional view taken along line C-C in FIG. cross-sectional side view,
Fig. 6 is a front view of Fig. 4, Fig. 7 is an enlarged cross-sectional view showing the stepped portion of the girder joint, and Fig. 8 is a cross-sectional view of an example of the substantially corrugated portion constituting the deck board of the pallet of this invention. figure,
FIG. 9 is a plan view showing an example of a four-sided pallet according to this invention, FIG. 10 is a sectional front view taken along line D-D in FIG. 9, and FIG. 11 is a front view taken along line E-E in FIG. 9. Fig. 12 is a cross-sectional plan view taken along line FF in Fig. 10 (the left half is omitted because it is symmetrical with the right half), Fig. 13 is a side view taken along line GG in Fig. 12,
FIG. 14 is a cross-sectional side view taken along line HH in FIG. 12. In the figure, 1 is a pallet, 1a and 1b are pallet forming members,
2 is a deck board, 3 is a girder, 3' is a girder forming member, 4 is a vertical rib, 5 is a flat plate portion, 6 is a substantially corrugated portion, and 7 is a reinforcing vertical lip.

Claims (3)

[Scope of utility model registration request] (1) A pallet formed by welding together upper and lower two pallet forming members made of thermoplastic synthetic resin, the pallet forming members being a deck board and a girder forming member integrally provided on the inner surface of the deck board. The deck board has a substantially corrugated portion formed by a plurality of vertical ribs and flat plate portions alternately connecting the upper and lower portions of the vertical ribs, and the generally corrugated portion is formed of at least one of the pallets. A synthetic resin bullet, characterized in that a vertical rib having a substantially wave-shaped portion is provided near the end of a fork insertion hole so as to intersect with the direction in which the fork is inserted. (2) The synthetic resin pallet according to claim 1, which is a registered utility model, characterized in that a plurality of reinforcing vertical ribs are provided in directions alternating with the vertical ribs of the substantially corrugated portion. (3) The synthetic resin pallet according to claim (1), wherein the vertical ribs of the substantially corrugated portion have a trapezoidal cross-sectional shape.