JP2002249132A - Spring structural resin pallet and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin pallet having high impact-absorbing capability, load resistance, and durability and also convenient for storage or the like. SOLUTION: The pallet 30 has a three-dimensional structure with a clearance of predetermined volumetric density in which some adjacent random looped or curled lines of the continuous lines of thermoplastic resin and/or short lines are adjoined. Fork insertion openings 23, 23 of recessed shapes are formed between adjacent beams 21, 21, 21 or blocks in a way that the width of each opening is made wider than that of each beam or block.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin pallet having a spring structure and a method for manufacturing the same, and more particularly, to a shock-resistant, load-resistant, and durable cushioning material having a long life, light weight, and simple manufacturing. The present invention relates to an inexpensive resin pallet having a spring structure and a method for manufacturing the same.

[0002]

2. Description of the Related Art Pallets used for transshipping or transporting goods by forklift are light in weight, articles having a large surface friction coefficient are not slippery, and water adhering to the surface is immediately absorbed. In general, wood is often used because of the lack of water on the goods.

This wooden pallet nails between the upper end and the lower end of a plurality of wooden digits arranged in parallel at a predetermined interval in the width direction of the pallet, and a rectangular parallelepiped leg (block) used in place of the digit. The pallet is connected to the pallet by connecting it with a deck board made of a wooden board by screwing or screwing, etc., and inserting the fork of a forklift etc. It is formed (see FIG. 10).

[0004] In this specification, in accordance with the terms of JIS Z 0106, the length of a pallet is defined as the length of a pallet or a pallet in the longitudinal direction of the pallet or the one without a pallet or a pallet. In this case, the total length of the pallet in the direction in which the dimension of the surface is shorter is referred to. In addition, the description will be made assuming that the vertical dimension of the pallet is the pallet height.

[0005]

The most frequently used wooden pallets at present are the advantages of low production cost and a certain strength, but the disadvantages are the large weight and high water content. It is easy to corrode, so it is easy to corrode and its life is short. In addition, since it is easily soiled at an early stage, it is difficult to use it in the food industry and the pharmaceutical industry. Furthermore, when the pallets are leaned against the pallets, there is a problem that the lower end of the pallets which absorb and contain a large amount of rainwater is corroded quickly.

On the other hand, a plastic pallet has a complicated rib structure in order to reduce the weight, and is manufactured by separately injection-molding the upper and lower surfaces of the pallet and then fusing the upper and lower surfaces thereof, and has a long life. It has the advantage of being hard to get dirty, but its cost is much higher than wooden pallets.
Does not have durability and impact strength.

[0007] That is, the conventional plastic pallet has a rib structure in order to increase the strength while reducing the weight with a plastic having a specific gravity heavier than wood. Although it has a long life, it has the disadvantage that it deforms or cracks during long-term use.

On the other hand, steel pallets have very high strength, but are heavy and have the drawback of being corroded by rust.

Further, since the pallets configured as described above have a relatively high height, a relatively large storage space is required when they are stacked and stored.

[0010] The present invention solves the above-mentioned problems, and differs from a conventional resin pallet because of its spring structure.
Stress concentration does not occur, it can withstand long-term use, and in manufacturing, and because conventional plastic pallets are complex shapes, molding is injection, injection compression, or extrusion compression, and each part is a corresponding mold However, in the present invention, it can be easily manufactured with one molding machine and a molding die, and has desired properties, particularly high impact resistance. It is an object of the present invention to provide a pallet having the property and load resistance.

Another object of the present invention is to provide a lightweight resin pallet having desired physical properties such as load resistance and impact resistance and having a rib structure.

Yet another object of the present invention is to provide a stack,
Another object of the present invention is to provide a resin pallet that can be compactly stored when stacked and stored in a relatively narrow storage place.

[0013]

In order to achieve the above-mentioned object, the resin pallet 30 of the present invention comprises a continuous line and / or a short line of thermoplastic resin in a random loop or a curl between adjacent lines. Are formed in a three-dimensional structure having voids of a predetermined bulk density formed by contact entanglement, and are formed between adjacent digits 21 or blocks with a width and an interval at which the digits 21 or blocks can be fitted. A groove-shaped fork insertion port 23 is formed (claim 1).

The spring structure resin pallet 30 is
When the high-density portion H is formed by increasing the bulk density of the three-dimensional structure, and the high-density portion H is formed with the longitudinal direction between both ends of the pallet 30 in the length direction (the high-density portions 42 and 4).
(3, 44), the longitudinal direction is formed between both ends of the pallet in the width direction (high-density portions 33, 34, 35), and at least the outer peripheral position in the width direction cross section of the pallet 30 (the pallet A flat portion M having a bulk density equal to or less than the high-density portion is formed at a position forming a peripheral edge (claim 2).

The continuous filaments and / or the short filaments may be formed of a thermoplastic elastomer (claim 3), and have a wire diameter of 0.1 to 3.0 mm, preferably 0.1 to 3.0 mm.
It is 3 to 0.7 mm (claim 4).

Further, the bulk density of the three-dimensional structure can be preferably 0.1 to 0.9 g / cm ³ (Claim 5).

A portion other than the high-density portion H and the flat portion M is replaced with a rough portion L having a bulk density equal to or less than the flat portion M.
(Claim 6).

The diameter of the continuous filament and / or the short filament of the rough portion L is 0.1 to 3.0 mm, preferably 0.7 to 3.0 mm.
1.5 mm, and the bulk density of the three-dimensional structure is 0.01 to 0.1 g / cm ³ , preferably 0.02 to 0.1 g / cm ³ .
It can be 0.05 g / cm ³ (claim 7).

Furthermore, the two resin pallets 30 having the spring structure formed as described above may be connected to each other by overlapping the digits 21 or the bottoms of the blocks to form a double-sided pallet. .

Further, the method for manufacturing a resin pallet having a spring structure according to the present invention is characterized in that a thermoplastic resin and / or a thermoplastic elastomer is melt-extruded into a plurality of filaments, and a random loop of continuous filaments or adjacent filaments of curl are formed. To form a pallet consisting of a three-dimensional structure having voids of a predetermined bulk density by contact entanglement assembly, the melt-extruded continuous filaments are arranged opposite to each other at predetermined intervals, for example, a take-up roll 1
4a, 14b, while being sandwiched between the holding bodies, it is pulled to form a predetermined thickness, and one of the holding bodies (the take-up roll 14a) is provided with a ridge 141 whose length is the extrusion direction of the continuous filament. The grooved fork insertion openings 23, 23 are formed in the portions sandwiched by the formation portions of the ridges 141.
Is formed (claim 9).

A forming die 12 for extruding the continuous filament.
In addition, a non-formed portion of the injection port 18 may be provided corresponding to the formation position of the fork insertion ports 23, 23 (claim 10).

Further, for example, by attaching to the forming die 12, the shape of the insertion ports 23, 23 is formed in front of the continuous filament in the injection direction and in correspondence with the formation positions of the fork insertion ports 23, 23. Cores 17, 17 having a shape corresponding to
Can be arranged (claim 11).

When the continuous filament is taken, the bulk density of the formed three-dimensional structure is changed by changing the take-up speed, and the high-density portion H (33) having a predetermined width and a high bulk density in the direction orthogonal to the take-up direction. , 34, 35) can also be formed (claim 12).

The injection openings 18 of the molding die 12 for injecting the continuous filaments are formed densely at predetermined intervals in the width direction of the pallet to be formed, and the height of the bulk density is high in the length direction of the pallet 30 to be formed. Density portions H (42, 43, 44) can also be formed (claim 13).

Further, the injection port 18 formed at least on the outer peripheral side of the molding die 12 is connected to the high-density portion H.
It is also possible to form the flat portion M having the following density so as to form the flat portion M having a bulk density equal to or less than the high-density portion.

At a position other than the position where the high-density portion H and the flat portion M are formed, the injection port 18 has a density equal to or lower than the flat portion M.
And a rough portion L having a bulk density equal to or lower than the flat portion M can be formed in a portion other than the high-density portion H and the flat portion M (claim 15).

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described below with reference to the accompanying drawings.

[Example 1 (FIG. 1)] (Three-dimensional structure) In the present invention, the resin pallet is made of a continuous line and / or a short line of thermoplastic resin in a random loop or adjacent lines of curl. And a three-dimensional structure having voids of a predetermined bulk density formed by contact entanglement.

Such a three-dimensional structure is melted and extruded at a predetermined extrusion speed by, for example, a molding die having a plurality of injection ports or the like, and the thermoplastic elastomer is taken out by a take-off machine 13 which will be described later. ,
Preferably, a solid or hollow continuous filament of 570 to 14,300 denier is formed, and a loop having a diameter of, for example, 1 to 10 mm, preferably 1 to 5 mm is formed in the molten filament. Forming a random loop by contact entanglement with water in the water,
And the resin pallet 30 is formed.

(Forming Die) FIGS. 4A to 4C show an example of a forming die used for manufacturing the above-described three-dimensional structure. The molding die 12 shown in FIGS. 4A to 4C has a large number of injection ports 18 through which the molten resin introduced through the extruder 10 is injected, and passes through the injection ports 18. The injected resin material is injected as continuous filaments, and the filaments form random loops or curls and are welded and entangled with each other to form a three-dimensional structure by taking-off by a take-off machine 13 described later. Is done.

In the present embodiment, the forming die 12
Fork insertion port 23 of spring structure resin pallet 30
Is provided with a core 17 projecting in the injection direction of the continuous filament, and since the injection port 18 is not formed at the position where the core 17 is formed [FIG. ) And FIG. 4 (C))], since the filament is not injected at this portion and the formation of the three-dimensional structure is hindered at the position where the core 17 is arranged. The structure has a concave portion at the position where the cores 17 and 17 are formed, and this concave portion is a position where a fork such as a forklift is formed after the resin pallet is formed.

In the production of the resin pallet of the present invention, the core is not essential, for example, as shown in FIG.
In the forming die 12 shown in FIGS. 4A to 4C, a molding die having no core 17 can be used. For example, the formation position of the core 17, that is, the resin pallet 30 is formed. When a molding die is used in which the injection port 18 is not formed at the position where the insertion port 23 is formed, or when the injection port 18 is formed at the portion where the insertion port 23 is formed.
May be closed by, for example, a padding or the like, so that continuous filaments are not injected in this portion.

In addition, the resin pallet 30 of the present invention can be manufactured by using not only the cores 17 and 17 but also a molding die having no portion where the injection port 18 is not formed. Even in this case, when a continuous filament injected by a take-off machine described below is formed into a predetermined shape, a concave portion having a predetermined width is formed in the take-off direction, and the concave portion allows the insertion port 23 of the fork to be formed. It is formed in the length direction of the resin pallet.

However, in order to form the insertion port properly and accurately, it is preferable to manufacture a resin pallet using a molding die having the above-described core.

The injection port 18 formed in the molding die 12
Are centered at both ends in the width direction of the resin pallet 30 [FIG.
In FIG. 4 (C), it is densely formed at a position H ′ indicated by a one-dot chain line, and the outer periphery of a portion where the injection port 18 of the molding die 12 is formed [a position indicated by a two-dot chain line in FIG. M ′], it is formed at a high density next to H ′, and is formed in a rough state in the remaining portion [L ′ in FIG. 4C].

The diameter of the continuous filament and / or the short filament injected by the molding die 12 is, for example, 0.1 to 0.1 mm.
It is 3.0 mm, preferably 0.3-0.7 mm.

The continuous and / or short filaments are preferably made of a thermoplastic elastomer, for example, polypropylene, polyester, nylon or PVC elastomer.

When continuous filaments are injected by using the molding die 12 having the injection port 18 formed as described above, the high-density portion H (42,
43, 44) are formed at regular intervals in the width direction of the resin pallet 30 (see FIG. 1 (E)).
43, 44), the resin pallet 30 is reinforced.

Further, a portion (M ') located at the outer periphery of the portion where the injection port 18 is formed and where the injection port 18 is arranged at an intermediate density.
The high density portion 42,
Although the density is lower than 43 and 44, a flat portion M having a higher density than other portions is formed.

Although the flat portion M is not as dense as the high-density portion H, the bulk density of the three-dimensional structure is relatively high, so that the desired strength of the resin pallet 30 is maintained and a load is placed. Since necessary flatness can be ensured and a desired gap is provided, good water drainage can be obtained even when wet with water.

Further, of the three-dimensional structure, the portion formed by the continuous filament injected through the portion (L ') where the density of the injection port 18 is the coarsest is the most of the three portions. It is formed coarsely and provides a lightweight resin pallet and good drainage performance.

(Taking-off machine) FIGS. 5A to 5 show an example of the taking-up machine 13 which takes out the continuous filament injected through the above-mentioned forming die and forms it into a predetermined shape to form a resin pallet.
It is shown in (C).

The take-off machine 13 is provided with the above-described forming die 12.
To control the take-up speed of the continuous filaments ejected through the device, thereby forming a loop or a curl in the ejected continuous filaments to form a three-dimensional structure. As a result, the injected continuous filament is drawn in a state close to a straight line to form a three-dimensional structure having a low bulk density, and a loop or a curl is formed densely by lowering the pulling speed, thereby reducing the bulk. A three-dimensional structure with a high density is formed.

The take-up machine 13 changes the take-up speed at a predetermined timing so that a continuous line is formed at predetermined intervals in the length direction of the formed resin pallet 30 and the width direction of the resin pallet 30 as the length direction. It is possible to form a high-density portion H (33, 34, 35) in which the stripes are densely formed and a rough portion L in which the density of the continuous filaments is low. At least some of the joints are melt bonded to each other.

In the present embodiment, a timing for reducing the take-up speed three times during the take-up process of one resin pallet 30 is provided. A high-density portion H (33, 34, 35) is formed in which the length direction is the width direction of 30.

For example, a pallet unit 30 defined by the JIS standard
In the resin pallet 30 shown in FIGS. 1A to 1E showing the first embodiment, the width direction of the resin pallet 30 is adjusted in the length direction by adjusting the take-up speed of the take-up machine 13 at the length interval. High-density portion H (33 to 35)
The rough part L formed between (33-35) is formed.

As described above, the portion H having a large bulk density at the time of low-speed pick-up, that is, the high-density portion and the rough portion L other than the high-density at the time of high-speed pick-up are formed in the width direction of the resin pallet 30 to be formed. Can be formed as a length direction to form a three-dimensional structure having a predetermined thickness alternately formed.

The take-up rolls 14a, 14 of the take-up machine 13
5B is formed by a pair of take-off rolls 14a and 14b opposed to each other with a predetermined interval corresponding to the height of the resin pallet 30 formed as shown in FIGS. 5A to 5C. In the present embodiment, contact portions with the injected continuous filaments are formed as take-up rolls 14a and 14b formed with the conveyor belts 142 and 143 so that the continuous filaments that are taken over a longer distance can be clamped. I have.

On the surface of the conveyor belt 142 of one of the take-up rolls 14a and 14b (14a), a portion corresponding to the formation position of the fork insertion port 23 is formed in the shape of the fork insertion port 23 formed. Corrugated ridge 1
41 and 141 are provided.

Therefore, the continuous linear member is sandwiched between the conveyor belt 142 having the convex portions 141 and 141 formed thereon and the flat conveyor belt 143 having no convex portions 141 and 141 formed, and is drawn at a predetermined speed. As a result, a concave portion corresponding to the shape of the protrusions 141, 141 is formed on one surface of the formed resin pallet 30, and the concave portion becomes the fork insertion ports 23, 23 of the resin pallet 30.

In this embodiment, the above-mentioned ridge 1 is used.
An example is shown in which only the conveyor belts 41 and 141 are provided so that the rotation direction of the conveyor belt is the length direction. For example, when the resin pallet to be formed is a four-sided pallet, a direction perpendicular to the ridges 141 and 141 is used. May be further formed on the surface of the conveyor belt, and a lattice-shaped groove may be formed on the formed resin pallet. In this case, the above-mentioned digit 21 is divided in the length direction to form a “block”.

The bulk density of the three-dimensional structure thus formed is 0.01 to 0.1 g / cm ³ , preferably 0.02 to 0.05 in the rough portion L, and the high density portion H 0.3 ~
0.9 g / cm ³ , preferably 0.5 to 0.7 g / cm ³
It is. The middle flat portion M is 0.1 to 0.9 g / cm ³ ,
Preferably, a 0.3 to 0.7 g / cm ^3.

The porosity of the three-dimensional structure is determined by the roughness L
88-99%, preferably 94-98%, especially 9
4 to 96%, 0 to 66% in the high density portion H, preferably 2
It is 2 to 44%, especially 20 to 30%. In the flat part M,
It is located at an intermediate value between the two.

Here, the porosity is represented by the following equation. Porosity = (1−bulk density / resin specific gravity) × 100

After the completion of the take-off corresponding to the length of each of the pallets 30 at the time of the take-off, the take-up speed is further increased for a predetermined time as compared with the formation of the rough portion L, so that each fiber becomes substantially linear. The cutting portion F is formed, and the resin pallets formed in a state where the plurality of resin pallets 30, 30,... Are connected are cut by the cutting device 19 at the cutting portion F, thereby continuously forming the resin pallets. , The individual resin pallets 30 can be collected (see FIG. 2).

(Cutting Apparatus) FIG. 3 shows a manufacturing apparatus constructed so that continuously manufactured resin pallets 30, 30,... Can be cut in the bus 15 and collected as individual resin pallets 30. The cutting device 1
Reference numeral 9 denotes a transport device 11 which is located near the lower part of the take-up machine 13 and is provided on the opposite side wall of the bus 15 with a conveyor provided with a large number of locking projections which are inserted into gaps of the pallet alone cut at the cutting site F. ing. In the figure, 25 is a water absorption valve,
26 is a drain valve.

(Others) The three-dimensional structure cut at the cutting portion F as described above can be used as it is as a resin pallet as it is. After the shape is adjusted, the resin pallet 30 may be used.

(Manufacturing Method) In the manufacturing method of the spring-structured resin pallet 30 of the present invention, as shown in FIG.
A raw material resin, for example, an elastomer of polypropylene is charged from a hopper of the extruder 10, melt-kneaded, and extruded from a number of injection ports 18 having a predetermined diameter provided in a forming die 12, and a take-up roll of a take-up machine 13 in a bus 15. 14
The thickness and the bulk density are set between a and 14b, and while being randomly formed into a curl or a loop, they are solidified in the water of the bath 15, taken out by the winders 16, 16, and cut by the cutting device 19 as described above. It is cut at the portion F and taken out as a resin pallet 30 having a spring structure.

As an example, the raw resin is charged from a hopper of a single-screw extruder having a diameter of 65 mm, the molten resin is discharged from a molding die, and the resin is picked up by a picking machine 13 at a predetermined picking speed pattern.

The resin material heated and melted by the extrusion by the extruder 10 is discharged from a number of injection ports 18 provided in the forming die 12 to form a solid or hollow continuous filament having a predetermined wire diameter. Take-off machine 13 for ejected continuous filament
By forming a loop or a curl in the melted filament by taking a pattern with a predetermined take-up speed,
While forming a random loop by contacting and entanglement of this filament with an adjacent filament in water, the pulling speed of the pulling machine 13 is adjusted to a low speed at predetermined intervals by the pulling machine 13 in water, for example, , Take-up rolls 14a, 1
If the take-up speed of 4b is set to a low speed within a set time at predetermined intervals by a timer, the formed resin pallet 30 alternates between a high-density portion H having a high bulk density and a coarse portion L having a low bulk density in the longitudinal direction. This high-density portion H acts as a member for improving the strength of the pallet, like the rib in the conventional resin pallet.

In the above-described take-up machine 13, one of the take-up rolls 14a has a ridge 141, 141 formed at a portion corresponding to the position where the fork insertion port 23 is formed. , 14b, a concave portion corresponding to the shape of the ridges 141, 141 is continuously formed in the take-up length direction, and the concave portion is formed in the fork insertion port 2 in the resin pallet 30.
3,23.

In particular, when the continuous filament is discharged by using the forming die having the core 17 as described above, the formation of the fork insertion ports 23, 23 can be made easier and more reliable.

A random curl or a loop is formed in the continuous filament injected from the molding die 12 in this way, and fork insertion ports 23, 23 are formed and solidified in water. The resin pallet 30 is taken out by the 16 take-up rolls.

The take-up roll 14 of the take-up machine 13 in the bus 15
The thickness and the bulk density are set between a and 14b, and the portion that becomes the resin pallet 30 at the time of the above-mentioned take-off is formed at the time of molding.
Since it cannot be bent by a roll, it is bent at the cut portion F which is formed coarsely, and is thereby pulled up from the water.

In the example in which the cutting device 19 shown in FIG. 3 is provided underwater, the resin pallet alone cut at the cutting portion F by the cutting device 19 disposed below and near the take-off machine 13 is: Each of the resin pallets is taken out of the bus by a transfer device provided on the opposite side wall of the bus to obtain a single resin pallet.

As described above, in the present embodiment, the following resin pallets were obtained by the above-described method. Pallet only 900 x 900 x 115 mmWeight 8 kg Fork slot width 250 x 900 x 60 mm

The resin pallet 30 formed as described above
As described above, not only can it be manufactured relatively easily with one molding machine and molding die, but also because of the spring structure, stress concentration does not occur, it can withstand long-term use, and the desired properties, particularly high It has impact resistance and load resistance.

Further, according to the above-described shape, when the two pallets are stacked and stored, for example, the bottoms of the two pallets alone are opposed to each other so that the fork difference of one of the resin pallets is as shown in FIG. The digits 21 and 21 of the other resin pallet are fitted into the inlets 23 and 23, and the thickness when they are overlapped can be reduced.

Therefore, the number of storage locations can be reduced, and the pallet in which the digits 21 and 21 are fitted and combined is less likely to collapse.

[Embodiment 2 (FIG. 7)] FIG. 7 shows that the resin pallet 30 formed as described above
This is an example in which the bottoms of the upper and lower parts 21 and 21 are arranged so as to face each other up and down, and the digits are connected to each other via a connecting member such as a bolt to form a double-sided resin pallet.

As described above, the two resin pallets 30, 3
By connecting the single pallets, a double-sided pallet can be easily formed, and it can also be used as a single-sided pallet according to the application.

For storage, etc., bolts are removed and each is disassembled into individual resin pallets.
There is an advantage that the space required for storage can be reduced by stacking two pallets alone with their bottoms facing each other.

[Embodiment 3 (FIG. 8)] The resin pallet of this embodiment has a hollow portion 36 penetrating through the digits 21, 21 and 21 in the longitudinal direction. It is manufactured by a molding die configured to meet the requirements.

Further, in the embodiment shown in FIGS. 1A to 1E, the high-density portions H (in the length direction) provided at equal intervals at both ends and the center of the pallet in the width direction. 42,4
Instead of the flat portions M forming the upper walls of the fork insertion ports 23, and the flat portions M on the surface of the deck board 52 forming the upper end of the resin pallet 30, four high-density portions H are provided instead of the flat portions M, 3, 44). The ribs 37 are formed to further reduce the weight of the resin pallet 30.

Further, the high-density portion H in the width direction of the pallet
However, two more are added to the three resin pallets shown in FIGS. 1A to 1E, and the high-density portions H (33, 34,
The high-density portions 33 'and 35' are provided at intermediate positions of 35), respectively, and are reinforced.

The sizes of the resin pallets shown in FIGS. 5A to 5F are as follows as an example. Pallet only Width 1100 x length 1100 x thickness 150 mm Weight 13 kg Fork slot width 250 x length 1100 x thickness 70 mm

In the resin pallet 30 of the third embodiment, as shown in FIG.
The resin pallets of the double-sided use type can also be formed by superimposing 30.

[Embodiment 4 (FIG. 9)] Embodiment 4 shows a production example in which the height of the pallet is lower than that of the pallet of Embodiment 3, and the point that the hollow portion 36 is provided is described above. 5 (A) to 5 (F).

In this embodiment, the high-density portions H (42, 44) are provided near the opposite ends of the pallet in the width direction as the high-density portions H forming the longitudinal direction of the pallet. 1A to 1E, except that the high-density portion H (42, 44) is formed to be thinner than the pallet of the first embodiment.

Further, in the first embodiment, as shown in FIG. 9E, the fork insertion port 23 is not provided with the high-density portion 43 in the length direction formed in the center of the pallet in the width direction.
, A high-density portion H connecting between the upper ends of the upper portion and the flat portion M forming the upper end of the deck board 52 of the pallet,
38.

As for the high-density portions H forming the width direction of the pallet 30 as the length direction, four high-density portions H (33, 33'3), one more than the three pallets of the first embodiment.
5 ', 35), but by reducing the thickness, the required strength is maintained and the weight is reduced.

The sizes of the pallets in the embodiment shown in FIGS. 9A to 9E are as follows as an example. Pallet only Width 1100 x length 1100 x thickness 115 mm Weight 7 kg Fork slot width 250 x length 1100 x thickness 60 mm

[0083]

According to the structure of the present invention described above, according to the resin pallet of the present invention, unlike the conventional resin pallet, stress concentration does not occur due to the spring structure, so that it can withstand long-term use and can be manufactured in a long time. In addition, conventional plastic pallets have complicated shapes, so molding is performed by injection,
Injection compression or extrusion compression is required, and each part is molded with a corresponding mold, and work such as heat fusion and assembly is required.
A pallet having desired properties, particularly high impact resistance and load resistance, could be easily produced with a stand molding machine and a molding die.

Further, the present invention was able to provide a lightweight resin pallet having desired physical properties such as load resistance and impact resistance and having a rib structure.

Further, according to the resin pallet of the present invention,
It can be stored compactly when stored in a stack or in an overlapping manner, and thus can be stored in a relatively small storage space.

[Brief description of the drawings]

FIG. 1 is a view of a pallet showing an embodiment of the present invention, wherein (A) is a plan view, (B) is a left side view, and (C) is FIG.
FIG. 1A is a sectional view taken along line AA, and FIG. 1D is a sectional view taken along line BB in FIG.
FIG. 1E is a cross-sectional view taken along line CC of FIG.

FIG. 2 is a schematic diagram showing the entire manufacturing apparatus.

FIG. 3 is a schematic diagram showing the whole of another manufacturing apparatus.

4A and 4B show a molding die, wherein FIG. 4A is a front view, FIG. 4B is a partially enlarged view of a cross section taken along line AA of FIG. 4A, and FIG.
FIG. 5 is a sectional view taken along line AA of FIG.

5 (A) is a plan view, FIG. 5 (B) is a front view, and FIG. 5 (C) is a left side view showing a use state.

FIG. 6 is a sectional view of the resin pallet in a stored state.

FIG. 7 is an exploded cross-sectional view of a double-sided pallet formed by polymerizing two resin pallets.

8A and 8B are diagrams of a pallet showing another embodiment of the present invention, wherein FIG. 8A is a plan view, FIG. 8B is a left side view, and FIG.
FIG. 8A is a sectional view taken along line AA, and FIG. 8D is a sectional view taken along line BB in FIG.
FIG. 8E is a cross-sectional view taken along line CC of FIG. 8A.

9A and 9B are diagrams of a pallet showing another embodiment of the present invention, wherein FIG. 9A is a plan view, FIG. 9B is a left side view, and FIG.
9A is a sectional view taken along line AA, and FIG. 9D is a sectional view taken along line BB in FIG.
FIG. 9E is a cross-sectional view taken along line CC of FIG.

FIG. 10 is an explanatory view showing a conventional flat pallet.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Extruder 11 Conveyor 12 Forming die 13 Take-up machine 14 (14a, 14b) Take-up roll 141 Convex ridge 142, 143 Conveyor belt 15 Bus 16 Winder 17 Core body 18 Injection port 19 Cutting device F Cutting part L Rough part H High density part M Flat part 21 Digit 23 Fork insertion port 25 Water supply valve 26 Drain valve 30 Spring resin pallet 33,34,35 High density part (width direction) 36 Hollow part 37,38 Rib 42,43,44 Height Density part (length direction) 52 Deck board

Claims (15)

[Claims] 1. A three-dimensional structure having voids of a predetermined bulk density, comprising a continuous loop and / or a short loop of a thermoplastic resin and a random loop or a curl of adjacent filaments in contact with each other. A resin pallet having a spring structure, characterized in that a groove-shaped fork insertion opening is formed between adjacent blocks or blocks and has a width and an interval capable of fitting the blocks or blocks. . 2. The resin pallet having a spring structure includes a high-density portion formed by increasing the bulk density of the three-dimensional structure, and the high-density portion is formed with a longitudinal direction between both ends of the pallet in the length direction. A spring formed between the both ends of the pallet in the width direction as a length direction, and a flat portion having a bulk density equal to or less than the high density portion is formed at least at an outer peripheral position in a cross section of the pallet in the width direction. Structural resin pallets. 3. The resin pallet having a spring structure according to claim 1, wherein the continuous filament and / or the short filament are made of a thermoplastic elastomer. 4. The method according to claim 1, wherein the diameter of the continuous filament and / or the short filament is 0.1 to 3.0 mm, preferably 0.3 to 0.7 mm. A resin pallet with a spring structure as described in the item. 5. The bulk density of the three-dimensional structure is 0.1 to 5.
The resin pallet having a spring structure according to claim 1, wherein the resin pallet has a weight of 0.9 g / cm ³ . 6. A part other than the high-density part and the flat part is a rough part having a bulk density equal to or less than the flat part.
A resin pallet having a spring structure according to any one of claims 1 to 5. 7. The continuous filament and / or the short filament of the rough part have a wire diameter of 0.1 to 3.0 mm, preferably 0.7 to 1.5 mm.
And the bulk density of the three-dimensional structure is 0.01 to 0.1 g /
The resin pallet having a spring structure according to claim 6, wherein the pallet has a cm ³ , preferably 0.02 to 0.05 g / cm ³ . 8. A resin pallet having a spring structure, wherein two resin pallets having a spring structure according to any one of claims 1 to 7 are connected by overlapping each other with a digit or a block bottom. 9. A thermoplastic resin and / or thermoplastic elastomer is melt-extruded into a plurality of filaments, and random filaments of continuous filaments or filaments adjacent to curls are entangled with each other to form a predetermined bulk density. In forming a pallet composed of a three-dimensional structure having voids, the melt-extruded continuous filaments are pulled out while being sandwiched between sandwiching members arranged at predetermined intervals to form a predetermined thickness, and On one side of the body, a ridge having a length in the extrusion direction of the continuous filament is formed, and a groove-shaped fork insertion port is formed in a portion sandwiched by the ridge forming portion. Method for manufacturing a resin pallet having a spring structure. 10. The spring structure according to claim 9, wherein a non-forming portion of an injection port is provided in a forming die for extruding the continuous filament, corresponding to a formation position of the fork insertion port. Manufacturing method for resin pallets. 11. A core body having a shape corresponding to the shape of the insertion port is disposed in front of the continuous filament in the injection direction and corresponding to a position where the fork insertion port is formed. The method for manufacturing a resin pallet having a spring structure according to claim 9 or 10. 12. A high-density portion having a predetermined width and a high bulk density in a direction perpendicular to the take-off direction by changing the take-up speed and changing the bulk density of the formed three-dimensional structure when taking up the continuous filament. 9. The method according to claim 9, wherein the first member is formed.
A method for manufacturing a resin pallet having a spring structure according to any one of the preceding claims. 13. An injection port for injecting the continuous filament is formed densely at a predetermined position of a forming die, and a high-density portion having a high bulk density is formed in a length direction of a formed pallet. A method of manufacturing a resin pallet having a spring structure according to claim 9. 14. An injection port formed at least on the outer peripheral side of the molding die is arranged at a density equal to or less than the high-density portion, and a flat portion having a bulk density equal to or less than the high-density portion is formed. The method for producing a resin pallet having a spring structure according to any one of claims 9 to 13, wherein 15. An injection port is formed at a position other than the position where the high-density portion and the flat portion are formed at a density lower than the flat portion, and a bulk density lower than the flat portion is formed at a portion other than the high-density portion and the flat portion. The method for manufacturing a resin pallet having a spring structure according to claim 14, wherein a rough portion is formed.