JP2011079530A - Pallet made of synthetic resin - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a baggage from being attached with a mark of an opening part. <P>SOLUTION: A pallet made of a synthetic resin has an upper side deck board 2 and a lower side deck board 3 arranged as opposed to each other, and a plurality of beam parts 4 for connecting the upper side deck board 2 and the lower side deck board 3 and arranged in parallel at certain intervals each other, and an opening part 7 penetrating through the thickness direction is formed between the beam parts 4 of the lower side deck board. In the opening part 7, the edge part 7a positioned on the outer face side of the lower side deck board 3 is curved into a circular arc shape on a cross-section intersecting orthogonally to the edge part 7a. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a synthetic resin pallet that is used for carrying and storing various articles on a loading surface.

Conventionally, a synthetic resin pallet used for transporting and storing articles has been used.
As such a synthetic resin pallet, there is a pallet generally constituted by an upper deck board and a lower deck board arranged in parallel to each other and a plurality of girders connecting the upper deck board and the lower deck board. There are two types of synthetic resin pallets, one that is integrally formed and one that is formed by dividing the pallet into two substantially central portions at the upper and lower portions of the girders, but by joining the girders together.
There is also a so-called skid pallet composed of only a deck board and a girder.

For example, in the synthetic resin pallet described in Patent Documents 1 and 2, an insertion hole is formed through two opposing side surfaces between the upper deck board and the lower deck board. A fork lift or a pallet truck fork is inserted into the insertion hole when the synthetic resin pallet is conveyed.
A plurality of openings communicating with the insertion hole are formed between the beam portions of the lower deck board. This opening is for the wheels of the pallet truck to fall and be exposed to the lower surface side when the pallet truck is inserted into the insertion opening.

JP 2006-36331 A JP 2003-1555035 A

However, in the synthetic resin pallets described in Patent Documents 1 and 2, since the edge of the opening of the lower deck board is formed in a square shape, the upper part of the load is stacked with the load placed on the upper part. When a synthetic resin pallet is placed on the bag, the edge of the opening may be marked on the load due to the vertical load.
For example, when a package is packed in cardboard, the cardboard is partially recessed along the edge of the opening. In addition, it is inconvenient that a veneer plate or the like must be sandwiched between the load and the synthetic resin pallet so as not to leave a mark on the opening.

  The present invention has been made in view of the above-described circumstances, and provides a synthetic resin pallet capable of suppressing the edge of the opening from making a mark on the lower luggage when placed on the luggage. With the goal.

In order to achieve the above object, a synthetic resin pallet according to the present invention comprises an upper deck board and a lower deck board that are arranged to face each other, and are arranged in parallel at a distance from each other. A synthetic resin pallet having a plurality of girders for connecting boards, and an opening penetrating in the thickness direction between the girders of the lower deck board, wherein the opening is an edge At least a part of the lower end of each of the two is curved in an arc shape in a cross section perpendicular to the edge.
In the present invention, the opening is curved in an arc shape in the cross section orthogonal to the edge at the lower end of the edge, so that when the synthetic resin pallet is placed on the upper side of the luggage, the edge of the opening Since the lower end of the door does not come into contact with the load at the corner, it is possible to suppress the edge of the opening from making a mark on the lower load.

Moreover, in the synthetic resin pallet according to the present invention, the opening has an edge that extends in the extending direction of the spar formed by a part of the spar, and the spar that forms the opening. A strip-shaped reinforcing band extending in the extending direction of the girder portion is provided on the bottom surface of the girder.
In the present invention, the rigidity of the synthetic resin pallet can be increased by providing a band-shaped reinforcing band extending in the extending direction of the beam portion on the bottom surface of the beam portion forming the opening.

In the synthetic resin pallet according to the present invention, it is preferable that the reinforcing band is separated from a neutral axis of the synthetic resin pallet.
In the present invention, since the reinforcing band is separated from the neutral axis of the synthetic resin pallet, as is generally known in material mechanics, compared to the case where the reinforcing band is provided at a position close to the neutral axis. Thus, the moment of inertia of the cross section can be increased, and the rigidity of the plastic pallet can be increased.

Moreover, in the synthetic resin pallet according to the present invention, the reinforcing band may be formed with a hollow portion into which gas is injected.
In the present invention, since the hollow portion into which the gas is injected is formed inside the reinforcing band, the weight of the synthetic resin pallet can be reduced and the manufacturing cost can be reduced. It is possible to increase the productivity by preventing the molding distortion caused by the above.

  According to the present invention, since the lower end of the edge of the opening is curved in an arc shape, the edge of the opening marks the luggage when the synthetic resin pallet is placed on the upper side of the luggage. Since this can be suppressed, a pallet made of synthetic resin suitable for stacking can be obtained.

It is a perspective view which shows an example of the synthetic resin pallets by 1st embodiment of this invention. It is a perspective view which shows the back side of the synthetic resin pallets shown in FIG. It is an AA line end view of FIG. It is the BB sectional view taken on the line of FIG. FIG. 4 is a partially enlarged view of FIG. 3. (A) is a figure explaining the arrangement | positioning of a reinforcement band with the top view of a lower deck board, (b) is a figure which shows other arrangement | positioning of a reinforcement band. It is a figure explaining the cross-sectional shape of a reinforcement belt. (A) is a figure which shows a mode that the synthetic resin pallet by 1st embodiment was loaded on the upper side of a load, (b) is a figure which shows a mode that the conventional synthetic resin pallet was loaded on the upper side of a load. (A) is a figure which shows an example of the synthetic resin pallets by 2nd embodiment of this invention, (b) is the elements on larger scale of (a). (A) is a figure which shows the other shape of a reinforcement belt | band | zone, (b) is a figure which shows another shape of a reinforcement belt | band | zone. (A) is a figure which shows an example of the synthetic resin pallets by the modification of 1st Embodiment of this invention, (b) is the elements on larger scale of (a).

Hereinafter, a synthetic resin pallet according to a first embodiment of the present invention will be described with reference to FIGS.
As shown in FIGS. 1 to 4, the synthetic resin pallet 1 according to the first embodiment includes an upper deck board 2 and a lower deck board 3 which are arranged to face each other in the vertical direction, and an upper deck board 2 and a lower deck. The deck board 3 is connected to each other and includes three substantially columnar beam portions 4 arranged in parallel with a predetermined distance from each other, and is formed in a substantially rectangular parallelepiped shape as a whole.
In the present embodiment, the vertical direction in FIG. 1 will be described as the upper side and the lower side, and the extending direction of the beam portion 4 will be described as the beam direction.

The synthetic resin pallet 1 has a pair of insertion holes 5 formed between the beam portions 4 and extending in parallel to each other in the beam direction.
These insertion holes 5 penetrate two opposing side surfaces between the upper deck board 2 and the lower deck board 3 and have both ends in the width direction orthogonal to the extending direction substantially the entire length in the extending direction. It is formed so as to be sandwiched between adjacent beam portions 4. And as shown in FIG. 3, these insertion holes 5 are made into the substantially rectangular hole shape where the cross-sectional shape orthogonal to the extension direction was flattened.
The synthetic resin pallet 1 is a two-way insertion type synthetic resin pallet in which a fork lift or a fork of a pallet truck is inserted into the insertion hole 5 when being conveyed. The insertion hole 5 is formed to have a strength (withstand load) with respect to weight substantially uniformly over substantially the entire length in the extending direction.

The synthetic resin pallet 1 is formed by injection molding or the like using a material mainly composed of a polyolefin resin such as polyethylene, polypropylene or ethylene-propylene copolymer, or a thermoplastic resin such as polystyrene. Moreover, the synthetic resin pallet 1 formed in this way has a certain degree of elasticity. For example, when polypropylene is used, the flexural modulus is 0.8 × 10 ⁴ kg / cm˜1. 5 × is a ¹⁰ 4 kg / cm, in the case of using the high-density polyethylene, its flexural modulus is a ^{0.4 × 10 4 kg / cm~1.1 ×} 10 4 kg / cm.

  As shown in FIGS. 2 to 4, the upper deck board 2 has reinforcing ribs 6 that cross in the vertical and horizontal directions on the surface facing inward (downward) and facing the insertion hole 5 between the adjacent beam portions 4. It is arranged. The reinforcing rib 6 has a substantially plate-like shape that protrudes inward of the upper deck board 2 and extends. The reinforcing ribs 6 extend in a direction orthogonal to the girder direction and in a direction parallel to the girder direction, and are formed in a lattice shape in plan view.

  As shown in FIGS. 2 and 3, the lower deck board 3 has an opening 7 having a square shape in plan view on the bottom plate 11. Two openings 7 are formed between the beam portions 4 and communicate with the insertion hole 5. This opening 7 is for the wheel of the pallet truck to fall when the pallet truck is inserted into the insertion hole 5 and exposed to the lower surface side.

As shown in FIGS. 2 to 5, in the bottom plate 11 in which the opening 7 is formed, the edge 7a of the opening 7 is curved in an arc shape in a cross section in a direction perpendicular to the edge 7a, and R is formed. Has been.
The radius of R is 5 mm or more, preferably 5 to 10 mm. In the present embodiment, the radius dimension of R is 5 mm.
As shown in FIG. 3, the opening 7 is formed by the spar 4, the spar 4 side of the edge 7 a being continuous with the side plate 12 constituting the spar 4. At this time, R formed on the edge portion 7 a may be formed continuously on the side plate 12.
In addition, it is not necessary to make all the radius of R of the continuous edge 7a into the same dimension, and it is good also as a partially different dimension. Moreover, the part in which R is formed in the continuous edge part 7a, and the part in which it is not formed may be mixed. For example, the radius dimension of R and the presence or absence of R may be changed depending on the extending direction of the edge 7a. For example, the radius of R and the presence or absence of R may be changed between the edge 7a that is continuous with the side plate 12 and extends in the spar direction and the edge 7a that extends in the direction orthogonal to the spar direction.

As shown in FIGS. 3 and 5, the lower deck board 3 is formed with a band-shaped reinforcing band 14 that protrudes upward from this surface on the surface facing the inner side (upward) of the bottom plate 11. The reinforcing band 14 is formed in the girder 4 so as to extend in the extending direction of the girder 4. The reinforcing band 14 may be provided in a portion where the R of the edge portion 7a of the bottom plate 11 is finished.
As shown in FIG. 6A, the reinforcing band 14 may be formed in the entire region in the spar direction, and as shown in FIG. 6B, at least the side of the opening 7 on the spar portion 4 side. The opening 7 may be formed together with the length in the digit direction.

As shown in FIG. 5, the thickness t1 of the reinforcing band 14 is preferably 0.1 mm or more in order to exhibit the reinforcing performance, and is preferably 10 mm or less from the viewpoint of weight reduction. In the case of foam molding, a thick setting range of 5 to 10 mm is preferable.
Generally, since the thickness t2 in the girder 4 of the bottom plate 11 is about 3 to 5 mm, the combined thickness (t1 + t2) of the reinforcing band 14 and the bottom plate 11 is about 3.1 to 15 mm. By providing an upper limit to the thickness t1 of the reinforcing band 14 and increasing the distance from the neutral axis, the secondary moment of section can be increased efficiently and the rigidity can be increased, and molding distortion due to sink marks during the molding of synthetic resin can occur. Can improve productivity.

Further, as shown in FIG. 7, the thickness of the side plate 12 of the girder 4 is reduced in this embodiment as compared with the conventional lower deck board 43 in which R is not formed on the edge 7 a of the opening 7. It is formed as follows. In this embodiment, the side plate 12 of the girder 4 is thinner than the conventional lower deck board 43, and the strength is reduced because the R is formed on the edge 7a of the opening 7. A belt 14 is provided to increase the strength.
Compared with the conventional lower deck board, the lower deck board 3 of the present embodiment has a reduced volume due to the thickness of the side plate 12 of the girder 4 being thin and R being formed at the edge 7a of the opening 7. Therefore, it is preferable that the reduced volume and the volume of the reinforcing band 14 be the same or less.

Here, when the reinforcing band 14 is formed on the side of the opening 7 to the same length as the length of the opening 7 in the spar direction, and a continuous R is formed on the edge 7 a of the opening 7 and the side plate 12. The shape of the reinforcing band 14 will be described.
Compared with the cross-sectional area difference (area 40 in the figure) in the plane perpendicular to the girder direction between the conventional lower deck board 43 and the lower deck board 3 according to the present embodiment as shown in FIG. The cross-sectional shape of the reinforcing band 14 is set so that the cross-sectional area is the same or less.
Since the thickness t1 of the reinforcing band 14 is set as described above, the width w1 dimension can be determined by dividing the area of the region 40 by the thickness t1.

Further, as shown in FIG. 3, the reinforcing band 14 is preferably provided at a position away from the neutral shaft 15 of the synthetic resin pallet 1, and is provided on the bottom plate 11 of the lower deck board 3 in the present embodiment. Therefore, it is provided at a position farthest from the neutral shaft 15.
The neutral shaft 15 is a surface in which neither a compressive stress nor a tensile stress is generated in the synthetic resin pallet 1 when a vertical load acts on the synthetic resin pallet 1 to cause bending. By assigning the reinforcing band 14 at a position away from the neutral shaft 15, the sectional area of the surface of the synthetic resin pallet 1 perpendicular to the beam direction is assigned to the cross-sectional area of the reinforcing band 14 at a position away from the neutral shaft 15. Therefore, the cross-sectional secondary moment can be increased as compared with the case where the reinforcing band 14 having the same shape is provided near the neutral shaft 15 such as the side plate 12 of the girder 4.
In the present embodiment, the reinforcing band 14 is provided on the bottom plate 11 of the lower deck board 3. However, if the synthetic resin pallet 1 satisfies a desired strength, it is provided on the side plate 12 of the girder 4. May be.

Next, the operation when the synthetic resin pallet 1 according to the first embodiment is placed on a load will be described.
As shown in FIG. 8A, the luggage C is, for example, an article packed with cardboard, and a synthetic resin in which another luggage C is placed on the upper side of the synthetic resin pallet 1 on which the luggage C is placed. The made pallet 1 is loaded.
At this time, the bottom plate 11 of the lower deck board 3 is in contact with the upper surface of the load C, and a vertical load is transmitted from the bottom plate 11 to the load C.

At this time, as in the conventional lower deck board 43 shown in FIG. 8B, if the edge 47a of the opening 47 is formed in a square shape, the load concentrates from the edge 47a and is transmitted to the cardboard. Therefore, the edge 47a presses the load C, and the trace of the opening 7 remains on the cardboard.
Usually, there are various corrugated wave pitches p1 of 3 mm to 5 mm. Particularly, the corrugated cardboard of 3 mm thickness often used for the corrugated cardboard box has a corrugated cross-sectional wave pitch p1 of about 5 mm. The edge 47a fits between the wave pitches p1 to crush the waves and leave a mark on the cardboard.

On the other hand, in the first embodiment, as shown in FIG. 8A, R is formed on the edge 7a of the opening 7, so that the load from the edge 47a is dispersed to the cardboard. Since transmission is performed, concentration of the load of the load C on one wave of corrugated cardboard is avoided, and it is possible to prevent the load C from being pressed like a rectangular edge 47a shown in FIG. Cavities are reduced. Further, since the radius of R of the edge portion 7a is not less than 5 mm, the edge portion 7a does not easily fit between the corrugated cardboard wave pitches p1, which is about 5 mm. It can suppress putting on.
For this reason, in this embodiment, the radius of R is set to 5 mm. In consideration of the strength of the edge portion 7a, the thickness is preferably 10 mm or less.

Thus, the R dimension of the edge 7a is preferably set to be equal to or larger than the corrugated wave pitch p1.
Depending on how the luggage C is arranged, the corrugated wave pitch p1 and the wave direction (left and right direction in FIG. 8A) and the R forming direction of the edge 7a (left and right direction in FIG. 8A) and Therefore, the dimension of R may be changed according to the corrugated wave pitch p1 and the wave direction.
For example, when the edge portion 7a has a portion where the R forming direction is parallel to the corrugated wave direction and a portion orthogonal to the corrugated wave direction, the R forming direction is parallel to the corrugated wave direction. If the R dimension of the edge 7a of the portion to be larger than the corrugated wave pitch p1, the dimension of the edge 7aR of the portion where the R forming direction is orthogonal to the corrugated wave direction is greater than the wave pitch p1. May be larger or smaller, and R may not be formed in this portion.
However, since the corrugated cardboard wave formation direction and the edge formation direction R formation direction are different depending on the arrangement of the load C, in order to be able to use in any case, all the edges are used. It is preferable that R of the part 7a has the same radius.

  In addition, although the present Example demonstrated as having loaded the goods C packed in the corrugated cardboard on the synthetic resin pallet 1, it is not restricted to this, It can respond to mounting of various goods.

Next, effects of the synthetic resin pallet 1 according to the first embodiment will be described.
According to the synthetic resin pallet 1 according to the first embodiment described above, the opening 7 of the lower deck board 3 is loaded on the upper side of the load C because the edge 7a is curved and the R is formed. In this case, the edge 7a of the opening 7 presses the load C and has an effect of suppressing the opening 7 from being marked.
Further, since the reinforcing band 14 is formed at a position away from the neutral shaft 15 of the synthetic resin pallet 1, compared with the case where the reinforcing band 14 having the same cross-sectional shape is formed near the neutral shaft 15, the synthetic resin. The secondary moment of section of the pallet 1 can be increased, and the strength of the synthetic resin pallet 1 can be increased.

  Further, the reinforcing band 14 has a difference between the volume of the conventional lower deck board in which R is not formed at the edge portion and the volume of the girder portion of the lower deck board 3 which is reduced by forming R at the edge portion 7a. By determining the shape so as to have the same volume or less than the above, even if the reinforcing band 14 is installed, the weight of the synthetic resin pallet 1 is not increased as compared with the conventional case. Moreover, since the amount of resin does not increase by disposing the reinforcing band 14, the cost can be reduced.

Next, other embodiments will be described with reference to the accompanying drawings. However, the same or similar members and parts as those of the above-described first embodiment are denoted by the same reference numerals, and description thereof is omitted. A configuration different from the embodiment will be described.
As shown in FIGS. 9A and 9B, in the synthetic resin pallet 21 according to the second embodiment, a hollow portion that extends in the axial direction inside the reinforcing band 34 and into which the gas G is injected. 34a is formed.

When the lower deck board 23 is molded, the hollow portion 34a is filled with molten resin in the mold, and is inactive from the gas gate portion provided on the back surface or the front surface of the lower deck board 23 after a predetermined delay time has elapsed. By injecting gas into the reinforcing band 34, the gas is formed in the reinforcing band 34.
For example, nitrogen gas, which is a kind of inert gas, is used as the gas injected from the gas gate portion.
The reinforcing band 34 is preferably provided so as not to overlap with R at the edge 37a of the opening 37, and may be provided at a portion where the R of the bottom plate 31 ends. Thus, by providing the reinforcement band 34, the hollow part 34a is not formed in the edge part 37a, but it can prevent that the intensity | strength of the edge part 34a falls.

The synthetic resin pallet 21 according to the second embodiment has the same effect as that of the first embodiment, and includes the hollow portion 34a into which the gas G is injected into the reinforcing band 34. Weight reduction and manufacturing cost reduction can be achieved.
Further, since the hollow portion 34a is formed in the reinforcing band 34, the reinforcing distortion 34 and the bottom plate 31 do not cause molding distortion due to sink marks when the synthetic resin is molded.

As mentioned above, although embodiment of the synthetic resin pallets by this invention was described, this invention is not limited to said embodiment, In the range which does not deviate from the meaning, it can change suitably.
For example, in the above-described embodiment, the reinforcing band 14 has a thickness of the side plate 12 of the girder 4 that is thinner than the volume of the conventional lower deck board in which R is not formed at the edge, and the edge 7a. The shape is determined so as to be the same or smaller than the difference from the volume of the lower deck board 3 that is reduced by the formation of R, but other shapes may be used.
Further, the cross section of the reinforcing band 14 is not limited to a substantially rectangular shape as shown in FIG. 5, and the surface may be arcuate as shown in FIG. Further, as shown in FIG. 10B, a plurality of ribs 14a may be arranged at a predetermined interval between adjacent ribs 14a and installed as one reinforcing band 14. For example, in the reinforcing band 14 shown in FIG. 10B, four ribs 14a having a width w2 of about 5 mm and an interval between adjacent ribs 14a of 3 mm are arranged, and the width w1 is about 30 mm. It is good. The reinforcing band 14 shown in FIG. 10B having the dimensions described above obtains substantially the same reinforcing effect as the reinforcing band 14 shown in FIG. 10A has a thickness of about 5 mm and a width of about 20 mm. Can do.
In the above-described embodiment, the reinforcing band 14 is disposed on the bottom plate 11. However, the reinforcing band 14 may not be disposed, and instead of the reinforcing band 14, FIG. As shown in (b), the bottom plate 51 may be provided with ribs 52 protruding upward from the bottom plate 51 and extending in the girder direction. The extending direction of the rib 52 may be other than the girder direction, and may extend in a plurality of directions.

1,21 Synthetic resin pallet 2 Upper deck board 3 Lower deck board 4 Girder 7, 37 Opening 7a, 37a Edge 14, 34 Reinforcement band
15 Neutral shaft 34a Hollow part

Claims (4)

An upper deck board and a lower deck board arranged opposite to each other;
A plurality of girders that are arranged in parallel and spaced apart from each other to connect the upper deck board and the lower deck board, and there is an opening that penetrates between the girders of the lower deck board in the thickness direction. A formed plastic pallet,
The opening portion is a synthetic resin pallet characterized in that at least a part of a lower end portion of an edge portion is curved in an arc shape in a cross section orthogonal to the edge portion.   In the opening, an edge extending in the extending direction of the beam part is formed by a part of the beam part, and a bottom surface of the beam part forming the opening is formed in the extending direction of the beam part. The synthetic resin pallet according to claim 1, further comprising an extending band-shaped reinforcing band.   The synthetic resin pallet according to claim 2, wherein the reinforcing band is separated from a neutral axis of the synthetic resin pallet. The synthetic resin pallet according to claim 2 or 3, wherein the reinforcing band has a hollow portion into which gas is injected.

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