JP2013244977A - Pallet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pallet capable of storing cargos stacked on the pallet in a transport container as they are to improve workability of cargo handling and transport efficiency.SOLUTION: A pallet 40 which is stored in a transport container while a cargo 12 is loaded, includes: a flat upper face sheet 42 forming a loading face 41; and a bottom face sheet 43 for being placed on a bed of the transport container. The bottom face sheet 43 includes: thin plate parts 46 which are placed on right and left fork inserting parts of the transport container; a thick plate part 47 which projects downward from the thin plate parts 46 and formed between the right and left thin plate parts 46 for fitting to a space of the transport container; and right and left fork inserting parts 48 which are spaces formed both right and left sides of the thick plate part 47 by steps between the right and left thin plate parts 46 and the thick plate part 47, and which is used for inserting right and left forks 11 when the thick plate part 47 is grounded.

Description

  The present invention relates to a pallet, and relates to a pallet that is stored in a shipping container in a state in which a load is loaded.

  Various pallets represented by so-called flat pallets are widely used as cargo beds used in logistics (see, for example, Patent Document 1).

  Generally, a forklift insertion hole is provided on the side of the pallet. By inserting the fork of the forklift into this insertion hole and transporting and lifting the pallet, it is possible to move the cargo while it is stacked on the pallet, load it on the transportation vehicle, or lower it from the transportation vehicle. .

  Thus, in the cargo handling using the pallet, the cargo stacked on the pallet can be handled as one unit (so-called unit load), and the workability and transportation efficiency of the cargo handling can be improved.

  By the way, when a transport vehicle travels on an unpaved road and there is a possibility that the load stacked on the pallet may collapse, it may be obliged to store the load in a sturdy transport container.

  When storing the luggage in the shipping container, if the luggage stacked on the pallet is destroyed, it is necessary to pile up the broken luggage one by one in the shipping container, which is very troublesome. For this reason, it is preferable to store the luggage in the shipping container while being stacked on the pallet.

JP 2010-120678 A

  However, the conventional pallet needs a sufficient thickness to form the insertion hole for the forklift, and the cargo becomes bulky in the transport container by this thickness. For this reason, there may be a problem that the luggage cannot be stored in the shipping container or the height of the luggage exceeds the limit height. In such a case, in order to reduce the height of the load, it is necessary to lower a part of the load stacked on the pallet, which lowers the transportation efficiency.

  The present invention has been made in view of such circumstances, and an object of the present invention is to be able to store the cargo stacked on the pallet in the transport container as it is, and to improve the workability and transport efficiency of cargo handling. It is to provide a pallet that can.

The present invention is grasped by the following composition.
The pallet of the present invention has a left and right fork insertion part for inserting the left and right forks of a forklift, and a transport container having a space part formed between the left and right fork insertion parts and opened upward, A pallet that is stored in a state in which a load is loaded, and has a top surface portion that forms a loading surface on which the load is loaded, and a bottom surface portion that is placed on the loading platform, The left and right thin plate portions placed on the left and right fork insertion portions, and the thick plate portions that are formed between the left and right thin plate portions so as to protrude downward from the left and right thin plate portions and fit into the space portion, Left and right fork insertion portions, which are spaces formed on the left and right sides of the thick plate portion by steps of the left and right thin plate portions and the thick plate portion and into which the left and right forks are inserted when the thick plate portion is grounded; To have And butterflies.

  With this configuration, the pallet can be transported by a forklift by inserting the left and right forks into the left and right fork insertion portions formed by steps between the thin plate portion and the thick plate portion. Thereby, since the thin plate portion can be formed as thin as possible, when placing the pallet on the loading platform of the transport container, the thin plate portion formed on the fork insertion portion of the transport container must be placed. Can do. As a result, in the shipping container, the loading surface of the pallet can be lowered, and the height of the storage space in the shipping container can be increased.

  The pallet according to the present invention is a hollow molded body formed of a synthetic resin and having a hollow portion between the upper surface portion and the bottom surface portion.

  With this configuration, the durability of the pallet can be increased and the weight of the pallet can be reduced.

  According to the pallet of the present invention, the cargo stacked on the pallet can be stored in the shipping container as it is, and the workability of the cargo handling and the transportation efficiency can be improved.

It is an exploded view of the container unit using the pallet of the embodiment concerning the present invention. It is AA sectional view taken on the line of FIG. 1, and is sectional drawing of the pallet of embodiment. It is the perspective view which looked at the pallet of the embodiment from the bottom side. It is a bottom view of the pallet of an embodiment. It is operation | movement explanatory drawing of a container unit. FIG. 6 is a cross-sectional view taken along line BB in FIG. It is operation | movement explanatory drawing of the palette of a comparative example. It is a top view of the pallet for demonstrating the basic model used for analysis, (a) is a figure explaining the main dimension of a basic model and the load conditions of analysis A and B, (b) is the load condition of analysis C. It is a figure explaining.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention (hereinafter referred to as embodiments) will be described in detail with reference to the accompanying drawings. Note that the same number is assigned to the same element throughout the description of the embodiment. The drawings are viewed in the direction of the reference numerals. Further, in the embodiment, “up”, “down”, “front”, “rear”, “left”, “right” respectively indicate directions when facing the forklift from the transport container side or the pallet side. Show.

First, the container unit including the pallet of the embodiment will be described.
FIG. 1 is an exploded view of the container unit.

  As shown in FIG. 1, the container unit 10 includes a shipping container 20 and a pallet 40. The transport container 20 is formed in a substantially rectangular parallelepiped shape and includes a loading platform 21, a front frame 22, a rear frame 23, and a pair of side frames 25. The loading platform 21, the front frame 22, the rear frame 23, and the pair of side frames 25 are each a frame body having a substantially rectangular shape or a substantially square shape, and includes a metal rod member, a cylindrical member, or the like.

  The loading platform 21 constitutes the bottom of the transport container 20 and includes left and right fork insertion portions 26 for inserting the left and right forks 11 of the forklift, and a space portion 27 formed between the left and right fork insertion portions 26. Have.

  The fork insertion part 26 is a rectangular tube-like member that extends in the insertion direction (front-rear direction) of the fork 11 in the loading platform 21, and has an insertion hole 26a. The insertion hole 26a is formed in a shape that matches the cross-sectional shape of the fork 11, and is formed in a flat shape (here, substantially rectangular shape) that is long in the left-right direction.

  The space portion 27 is formed between the opposing surfaces of the left and right fork insertion portions 26 and is open upward and downward. A connecting member 28 extending in the left-right direction is disposed in the space portion 27. In this example, the opposing surfaces of the left and right fork insertion portions 26 are connected by a plurality of (for example, two) connecting members 28 to increase the rigidity of the loading platform 21.

  The front frame 22, the rear frame 23, and the side frame 25 are reinforced by a reinforcing member 31a extending in the vertical direction and a reinforcing member 31b extending in a staggered manner. The front frame 22, the rear frame 23, and the side frame 25 can be configured to be detachable from other adjacent frames and the loading platform 21, respectively. The means for attaching and detaching the front frame 22, the rear frame 23, and the side frame 25 can be selected from various attachment means such as fitting and screwing.

  1, the state which removed the front frame 22 from the loading platform 21 and the side frame 25 is shown. In this example, a support member 32 is provided at the front end of the loading platform 21 so as to connect the upper surfaces of the left and right fork insertion portions 26, and the front frame 22 is configured to be detachable from the support member 32 and the side frame 25. Yes.

  The pallet 40 is formed in a rectangular shape or a square shape in a plan view, and is stored in the transport container 20 in a state where the luggage 12 is loaded on the transport container 20. The pallet 40 includes a planar upper surface sheet (corresponding to the upper surface part) 42 that forms the stacking surface 41 of the luggage 12, and a bottom surface sheet (corresponding to the bottom surface part) 43 placed on the loading platform 21 of the transport container 20. And have.

Next, the structure of each part of the pallet 40 is demonstrated in detail based on FIGS.
As shown in FIG. 2, the pallet 40 has a hollow portion 45 between the upper surface side sheet 42 and the lower surface side sheet 43. The bottom surface side sheet 43 is a thin plate portion (a portion corresponding to the range of the reference numeral 46 (hereinafter referred to as the thin plate portion 46)) provided at the left and right end portions and a thick plate portion formed between the left and right thin plate portions 46 ( A portion corresponding to the range of reference numeral 47 (hereinafter, referred to as a thick plate portion 47), and left and right thin plate portions 46 and left and right fork insertion portions 48 formed by steps of the thick plate portion 47 are included.

  The left and right thin plate portions 46 are placed on the left and right fork insertion portions 26 (see FIG. 1) when the pallet 40 is placed on the loading platform 21 (see FIG. 1) of the shipping container. The thin plate portion 46 is provided with a plurality of first recesses 51 that are recessed from the bottom surface side sheet 43 side to the top surface side sheet 42 side. The 1st recessed part 51 is formed in arbitrary forms (for example, substantially truncated cone shape diameter-reduced toward upper direction), and an upper end part is welded to the back surface of the upper surface side sheet | seat 42. As shown in FIG. By forming the first recess 51, the first rib 52 is formed around the first recess 51. The first rib 52 reinforces the thin plate portion 46 by connecting the bottom sheet 43 and the top sheet 42 in the thickness direction.

  The thickness T of the thick plate portion 47 is set to be larger than the thickness t of the thin plate portion 46, and the thick plate portion 47 projects downward from the left and right thin plate portions 46. The bottom surface of the thick plate portion 47 forms a grounding surface that contacts the ground or the like. The thick plate portion 47 is fitted into the space portion 27 (see FIG. 1) when the pallet 40 is placed on the loading platform 21 (see FIG. 1) of the shipping container. The width in the left-right direction of the thick plate portion 47 is set to be approximately the same as or slightly smaller than the separation distance P of the forks 11.

  As shown in FIG. 3, the thick plate portion 47 is configured by a plurality (three in this case) of protruding portions 53 arranged in the front-rear direction. Each of the plurality of overhang portions 53 is formed in a substantially rectangular shape when viewed from the bottom. Each overhang 53 is provided with a plurality of (here, two) second recesses 55 arranged in the left-right direction. The second recessed portion 55 is formed to be recessed from the bottom surface side sheet 43 side to the top surface side sheet 42 side, and the upper end portion is welded to the back surface of the top surface side sheet 42. The shape of the 2nd recessed part 55 can be selected from arbitrary forms, and in this example, it forms in the form which combined the several substantially frustoconical recessed part diameter-reduced upwards. By forming the second recess 55, a second rib 56 (see FIG. 2) is formed around the second recess 55. The second rib 56 (see FIG. 2) reinforces the thick plate portion 47 by connecting the bottom surface side sheet 43 and the top surface side sheet 42 in the overhang portion 53 in the thickness direction.

  In the present embodiment, the hollow portion 45 (see FIG. 2) is formed between the bottom surface side sheet 43 and the top surface side sheet 42 to reduce the weight of the pallet 40, and the first rib 52 (see FIG. 2) and By providing the second rib 56 (see FIG. 2), the strength of the pallet 40 reduced in weight is increased.

  As shown in FIG. 4, a gap 57 is provided between two adjacent protruding portions 53. In the gap 57, when the pallet 40 is placed on the loading platform 21 (see FIG. 1) of the shipping container, the connecting member 28 (see FIG. 1) is fitted. Thereby, the thick plate portion 47 can be satisfactorily fitted into the space portion 27 (see FIG. 1) without the thick plate portion 47 interfering with the connecting member 28 (see FIG. 1).

  Further, inside the pallet 40, a plurality (four in this case) of reinforcing members 58 extending in the left-right direction are built in along the front edge of the pallet 40, the rear edge of the pallet 40, and the gap 57. The reinforcing member 58 is, for example, a metal bar member, and is inserted from the side surface of the pallet 40.

  Returning to FIG. As shown in FIG. 2, the left and right fork insertion portions 48 are spaces formed on the left and right sides of the thick plate portion 47 by the step between the left and right thin plate portions 46 and the thick plate portion 47. That is, the fork insertion portion 48 is a space corresponding to the difference (T−t) between the thickness T of the thick plate portion 47 and the thickness t of the thin plate portion 46, and is formed to open forward, rearward, downward and outward. When the thick plate portion 47 comes into contact with the ground or the like, the left and right forks 11 are inserted.

  By inserting the left and right forks 11 into the left and right fork insertion portions 48, the pallet 40 can be transported and lifted in the same manner as a normal flat pallet. For this reason, in the pallet 40, it is not necessary to separately form a hole for inserting the fork 11, and the thin plate portion 46 can be formed as thin as possible.

Here, an example of manufacturing the pallet 40 will be described.
The pallet 40 can be manufactured from various materials, but considering durability and weight reduction, the pallet 40 is preferably a hollow molded body formed of a synthetic resin. For example, the resin-made pallet 40 including the upper surface side sheet 42, the lower surface side sheet 43, and the hollow portion 45 can be obtained by blow molding. More specifically, a pair of split molds for forming the top sheet 42 and the bottom sheet 43 are used, and a molten cylindrical parison is formed in a cavity formed between the pair of split molds. A hollow molded body having a hollow portion 45 between the upper surface side sheet 42 and the lower surface side sheet 43 is formed by extruding and applying blowing pressure to the parison. Under the present circumstances, the 1st recessed part 51 and the 2nd recessed part 55 can be shape | molded by providing a convex part suitably in the metal mold | die molding surface which shape | molds the bottom face side sheet | seat 43. FIG. The molding material can be selected from various synthetic resins including polyolefin resins such as polypropylene and polyethylene.

  In addition, shaping | molding of a hollow molded object is not specifically limited to blow molding. For example, instead of the cylindrical parison, two molten sheets are arranged between a pair of split molds, and the sealed space between the sheets and the split molds is sucked, whereby the upper surface side sheet 42 is placed. A resin pallet 40 having a hollow portion 45 between the base plate 43 and the bottom sheet 43 may be formed. In such a molding method, since it is easy to put a foam material or the like as a core material between two sheets, a pallet 40 with higher rigidity can be obtained.

The operation and effect of the pallet 40 described above will be described with reference to FIGS.
As shown in FIG. 5, the pallet 40 with the load 12 stacked on the loading surface 41 is transported by a forklift and placed on the loading platform 21 of the transport container 20 (arrow (1)). Then, the front frame 22 is attached to the support member 32 and the left and right side frames 25 (arrow (2)).

  As shown in FIG. 6, a thin plate portion 46 formed as thin as possible is placed on the fork insertion portion 26 of the shipping container 20. Further, a thick thick plate portion 47 is fitted in the space portion 27 of the shipping container 20. As a result, in the shipping container 20, the position of the loading surface 41 can be lowered, and the height of the storage space in the shipping container 20 (the dimension indicated by the symbol H) can be increased.

  On the other hand, as shown in FIG. 7, when the conventional pallet 100 is stored in the shipping container 20, the fork insertion hole 101 simply overlaps with the fork insertion portion 26. For this reason, since the position of the stacking surface 102 is increased by the amount corresponding to the thickness t1 of the pallet 100, the height of the storage space in the transport container 20 (the dimension indicated by reference numeral H1) is small. Therefore, there is a problem that the luggage 12 does not enter the shipping container 20 or the height of the luggage 12 exceeds the limit height.

  In this regard, in the pallet 40 of the embodiment, as shown in FIG. 6, the height H of the storage space in the shipping container 20 can be increased, so that the luggage 12 stacked on the pallet 40 can be left as it is. It can be stored in the shipping container 20.

  Moreover, if the pallet 40 is comprised with the hollow molded object which consists of synthetic resins, durability of the pallet 40 can be improved and weight reduction of the pallet 40 can be implement | achieved.

(Analysis example)
In order to investigate the strength of the pallet 40 of the embodiment, an analysis model of the pallet 40 was set, and strength analysis was performed by CAE (Computer Aided Engineering). Details will be described below.

Analysis condition / basic model As shown in FIG. 8A, the basic model M used for the analysis was set in the same form as the pallet 40 (see FIG. 3). In the basic model M, the pallet width W was set to 1070 (mm) and the depth L was set to 1090 (mm). However, actually, considering the symmetrical shape of the basic model M, the strength analysis was performed using a 1/4 model of the basic model M (portion schematically shown by oblique lines) m.
Material conditions The material of the model m (excluding the reinforcing member 58) was set to polyethylene, and the material of the reinforcing member 58 was set to steel. Table 1 shows the physical properties of the set polyethylene and steel.

○ Analysis A to C
Assuming actual usage conditions of the pallet 40, three types of analyzes A to C with different load conditions were set. In each of the analyzes A to C, the maximum displacement of the loading surface 41 and the maximum stress generated in the model m / reinforcing member 58 were obtained.

・ Analysis A
In the analysis A, it is assumed that the load 3 (ton) is evenly applied to the load surface 41 of the pallet 40 placed on the flat ground. The load condition was such that a load of 3 (ton) / 4 = 750 (kg) was uniformly applied to the entire loading surface 41 of the model m.

・ Analysis B
In the analysis B, it is assumed that the pallet 40 in which the loading load 3 (ton) is uniformly applied to the entire loading surface 41 is lifted by the two forks 11. The load condition was such that a load of 3 (ton) / 4 = 750 (kg) was uniformly applied to the entire loading surface 41 of the model m. Here, the width W1 of the fork 11 is 125 (mm), the separation distance P between the two forks 11 is 650 (mm), the approach distance L1 of the fork 11 to the basic model M is 920 (mm), and the model of the fork 11 The approach distance L2 to m was set to 375 (mm).

・ Analysis C
In the analysis C, it is assumed that the pallet 40 in which the loading load 333 (kg) is applied to the central portion of the loading surface 41 is lifted by the two forks 11. Here, as shown in FIG. 8B, the central portion of the loading surface 41 is a central region C1 when the loading surface 41 is divided into nine in a lattice shape in accordance with the loading pattern of the lowermost package. . The load condition was such that a loading load of 333 (kg) /4=83.3 (kg) was applied to the region C2 included in the central region C1 in the model m (see FIG. 8A). Various dimensions related to the fork 11 were set to the same dimensions as in the analysis B.

Results / Analysis Results A to C are shown in Table 2.

  As shown in Table 2, even in the analysis C assuming the most severe use conditions, the maximum displacement of the loading surface 41 is suppressed to 4.6 (mm), and the model m has high strength. It was recognized that

  In addition, the maximum stress generated in the model m composed of polyethylene was around 20 (MPa) in any of the analyzes A to C, and there was no significant difference due to the difference in load conditions. On the other hand, the maximum stress generated in the reinforcing member 58 showed a high value in analyzes B and C assuming severe use conditions. From this result, it was confirmed that the reinforcing function of the reinforcing member 58 worked effectively, and thereby the stress generated in the pallet 40 was suppressed.

  From the result of the strength analysis by CAE, it was confirmed that the pallet 40 of the embodiment is excellent in load resistance and that the load resistance can be further improved by using the reinforcing member 58.

  As mentioned above, although this invention was demonstrated using embodiment, it cannot be overemphasized that the technical scope of this invention is not limited to the range as described in the said embodiment. It will be apparent to those skilled in the art that various modifications or improvements can be added to the above-described embodiments. Further, it is apparent from the scope of the claims that the embodiments added with such changes or improvements can be included in the technical scope of the present invention.

  For example, in the above-described embodiment, the example in which the pallet of the present invention is applied to the shipping container 20 including the loading platform 21, the front frame 22, the rear frame 23, and the pair of side frames 25 has been described. Can be applied to various transport containers having a space between the left and right fork insertion portions.

  In the embodiment, each of the upper surface portion and the bottom surface portion of the pallet according to the present invention is configured by the upper surface side sheet 42 and the bottom surface side sheet 43, but the upper surface portion and the bottom surface portion according to the present invention are the upper surface of the hollow molded body. The sheet forming the bottom surface is not particularly limited, and may be, for example, an upper part and a lower part of a pallet made of a solid resin molded body.

11 Luggage 20 Transport container 21 Loading platform 26 Fork insertion portion 27 Space portion 40 Pallet 41 Loading surface 42 Upper surface side sheet (upper surface portion)
43 Bottom sheet (bottom)
45 Hollow part 46 Thin plate part 47 Thick plate part 48 Fork insertion part

Claims (2)

A state in which a load is loaded on a shipping container having a left and right fork insertion portion for inserting left and right forks of a forklift and a space portion formed between the left and right fork insertion portions and opened upward. A pallet stored in
An upper surface portion that forms a loading surface on which the load is loaded; and a bottom surface portion that is placed on the loading platform;
The bottom surface portion is formed between the left and right thin plate portions placed on the left and right fork insertion portions and the left and right thin plate portions so as to protrude downward from the left and right thin plate portions and fits into the space portion. A space formed on the left and right sides of the thick plate portion by the thick plate portion and the steps of the left and right thin plate portions and the thick plate portion, and the left and right forks to be inserted when the thick plate portion is grounded And a fork insertion portion.   The pallet according to claim 1, wherein the pallet is a hollow molded body that is formed of a synthetic resin and has a hollow portion between the upper surface portion and the bottom surface portion.

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