Pallet

Abstract

To provide a pallet which has stable shape quality.SOLUTION: A pallet 10 has such a cylindrical structure that a plurality of side girder parts 20 positioned on both sides of a pair of fork insertion paths 90 penetrate in a vertical direction and have widths of 50 [mm] or less, wherein a middle position in a vertical direction of inward side walls 21 of the respective side girder parts 20 approaches a position closer to the outward side wall 22 than the end so that intervals between the inward side walls 21 and outward side walls 22 become narrower at a position closer to the middle position than the end in the vertical direction.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a resin pallet and a method for manufacturing the same. [Background technology]

[0002] A known type of pallet has multiple reinforcing walls arranged in parallel to bridge the upper and lower openings of the cylindrical wall that forms the outer shell of the girder, with the upper and lower reinforcing walls arranged in a staggered pattern (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 10-35669 A (Figs. 1 and 2, paragraph

[0013] ) Summary of the Invention [Problem to be solved by the invention]

[0004] However, there is a demand for downsizing of pallets so that multiple pallets can be laid out efficiently, and in order to meet this demand, it is necessary to reduce the width of the side girders by moving the outer surfaces of multiple side girders on both sides of a pair of fork insertion paths inward. However, if the width of the side girders is reduced while keeping the structure of the conventional pallet described above, the protrusions of the mold for molding the inside of the side girders become elongated and deformed by the resin pressure during molding, which can cause problems such as variation in the shape of the pallet. Therefore, the present disclosure provides a technology for stabilizing the shape quality of the pallet. [Means for solving the problem]

[0005] The invention of claim 1, made to solve the above problem, is a resin pallet in which a plurality of side girders located on both sides of a pair of fork insertion paths when a pair of forks of a hand lifter or forklift are inserted between a plurality of girders from a first horizontal direction form a cylindrical structure that penetrates in the vertical direction and has a width of 50 mm or less in a second horizontal direction perpendicular to the first horizontal direction, and in which the vertical midpoint of the inward side wall is closer to the outward side wall than the ends so that the distance between the inward side wall and the outward side wall facing each other in the second horizontal direction of each of the side girders is narrower at the midpoint than the vertical ends.

[0006] The invention of claim 2 is a pallet as described in claim 1, in which an intermediate region of the inward side wall located to the side of the fork insertion path is offset toward the outward side wall more than an upper region located above.

[0007] The invention of claim 3 is a pallet as described in claim 2, which has a curved portion between the upper region and the middle region of the inward side wall so that the upper corner of the fork insertion path on the side girder side when viewed from the first horizontal direction has an R-chamfered shape.

[0008] The invention of claim 4 is a pallet as described in claim 2 or 3, wherein the multiple girder portions are arranged in three rows and three columns, the lower ends of adjacent girder portions in the second horizontal direction are connected by a lower end connecting wall, the upper corners of the pair of fork insertion paths viewed from the first horizontal direction have an R-chamfered shape at the middle portion in the first horizontal direction and have pin-angle shapes at both ends in the first horizontal direction, and the lower corners of the pair of fork insertion paths viewed from the first horizontal direction have an R-chamfered shape at the middle portion and both ends in the first horizontal direction.

[0009] The invention of claim 5 is a pallet described in any one of claims 1 to 4, wherein only one of the sides of the inward side wall, either above or below a middle region located on the side of the fork insertion path, is offset away from the outward side wall, and the parting line of the mold is located inside the side girder portion, toward the other side, either above or below the middle region.

[0010] The invention of claim 6 is a resin pallet in which a number of side girders located on both sides of a pair of fork insertion paths when a pair of forks of a hand lifter or forklift are inserted between a number of girders from a first horizontal direction form a cylindrical structure that penetrates in the vertical direction and has a width of 50 mm or less in a second horizontal direction perpendicular to the first horizontal direction, and in which the vertical middle portion is carved out by the fork insertion paths.

[0011] The invention of claim 7 is a method for manufacturing a pallet using a resin injection molding mold to manufacture a pallet having a cylindrical structure in which a plurality of side girders located on both sides of a pair of fork insertion paths when a pair of forks of a hand lifter or forklift are inserted between a plurality of girders from a first horizontal direction penetrate in the vertical direction and have a width of 50 mm or less in a second horizontal direction perpendicular to the first horizontal direction, wherein a first molding protrusion protruding from a first mold and a second molding protrusion protruding from the second mold are made to have a thicker base end than a tip in order to form the inner surface of the side girders of a first and second mold that face each other in the mold opening direction of the injection molding mold, and the tip faces of the first molding protrusion and the second molding protrusion are abutted against each other at a vertical midpoint within the side girders. Effect of the Invention

[0012] In the pallets of claims 1 and 6, the side girders on both sides of a pair of fork insertion paths extending in the first horizontal direction have a width in the second horizontal direction of 50 mm or less, so that the width of the entire pallet (width in the second horizontal direction) can be reduced by 100 mm or more compared to a general conventional pallet whose width is 100 mm or more, and the pallet can be laid out efficiently. In addition, in order to mold the inner surface of the side girders, it was necessary to provide an elongated molding protrusion of approximately the same height as the total height of the side girders in the conventional injection molding die, but the pallets of claims 1 and 6 of the present disclosure have a cylindrical structure in which the side girders penetrate in the vertical direction, so that the molding protrusions for molding the inner surface of the side girders can be divided into a first molding protrusion and a second molding protrusion that face each other in the mold opening direction of the injection molding die, and can be made shorter than conventional ones.

[0013] This suppresses deformation of the first and second molded protrusions due to resin pressure, stabilizing the shape quality of the pallet. Moreover, in claim 1, the vertical midpoint of the inward side wall is closer to the outward side wall than the end so that the distance between the inward side wall and the outward side wall facing each other in the second horizontal direction of each side girder is narrower at the midpoint than at the vertical end of the side girder, so that the first molded protrusion or the second molded protrusion can be made thicker at the base end than at the tip end. Also, in claim 6, the vertical midpoint is hollowed out by the fork insertion passage, so that the first molded protrusion and the second molded protrusion can be made thicker at the base end than at the tip end. These also increase the bending strength of the first molded protrusion and the second molded protrusion, suppressing deformation of the molded protrusions due to resin pressure, stabilizing the shape quality of the pallet.

[0014] The width of the pallet can be reduced by having the fork insertion passage bite into the side girder to a position where the middle region of the inward sidewall located to the side of the fork insertion passage is offset toward the outward sidewall from the upper region located at the top, as in the pallet of claim 2. In this case, if a curved portion is provided between the upper region and middle region of the inward sidewall so that the upper corner on the side girder side has an R-chamfered shape, as in the pallet of claim 3, stress concentration is prevented, strength is increased, and water is less likely to accumulate between the middle region and upper region of the inward sidewall.

[0015] In the configuration of claim 4, the same effect as that of claim 3 is achieved in the girder portion at the middle part in the first horizontal direction.

[0016] In the pallet of claim 5, only one of the sides above or below the intermediate region located on the side of the fork insertion path of the inward side wall of the side girder is offset away from the outward side wall, so that only one of the first and second molded protrusions that mold the inside of the side girder, either above or below the intermediate region, has a thick base end. However, the parting line of the mold is located inside the side girder, closer to the other side above or below the intermediate region. In other words, molded protrusions with thin base ends are shorter than molded protrusions with thick base ends, making it easier to ensure strength.

[0017] The manufacturing method of a pallet of claim 7 divides the molding protrusion for molding the inner surface of the side girder into a first molding protrusion and a second molding protrusion that face each other in the mold opening direction of the injection molding die, making it shorter than before. This suppresses deformation of the first and second molding protrusions due to resin pressure, stabilizing the shape quality of the pallet. Moreover, since both the first molding protrusion and the second molding protrusion are thicker at the base end than at the tip end, the bending strength of the first molding protrusion and the second molding protrusion is also increased in this respect, suppressing deformation of the molding protrusions due to resin pressure and stabilizing the shape quality of the pallet.

[0018] The end faces of the first and second forming protrusions that come into contact with each other may be perpendicular to the contact direction or inclined. Furthermore, the end faces are not limited to flat surfaces, and may be correspondingly uneven or curved surfaces. [Brief description of the drawings]

[0019] [Figure 1] FIG. 1 is a perspective view of the top side of a pallet according to an embodiment of the present disclosure. [Diagram 2] A perspective view of the underside of the pallet [Diagram 3] Cross-sectional view of the girder [Figure 4] A perspective view of a part of the side girder at the end in the vertical direction. [Diagram 5] Front cross section of side girder at vertical end DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] A pallet 10 according to one embodiment of the present disclosure will be described below with reference to Figures 1 to 5. The pallet 10 according to this embodiment is a resin injection-molded product, and as shown in Figure 1, has a rectangular planar shape, with the vertical direction H1 being larger than the horizontal direction H2 of the rectangle.

[0021] The deck board 11 of the pallet 10 has a crosspiece structure and includes a plurality of vertical ribs 11A extending in the vertical direction H1 and a plurality of horizontal ribs 11B extending in the horizontal direction H2. Furthermore, horizontal reinforcement sections 12 in which the horizontal ribs 11B are spaced closer together than in the entire deck board 11 are provided at both ends and the center in the vertical direction H1 of the deck board 11. Furthermore, horizontal outer edge reinforcement sections 13 are provided at the edges of both ends in the vertical direction H1, which further space the two horizontal ribs 11B included in the horizontal reinforcement section 12 and space the vertical ribs 11A closer only between those two horizontal ribs 11B.

[0022] Deck board 11 is provided at both edge portions in the horizontal direction H2 with vertically elongated outer edge reinforcement portions 14, which have a structure obtained by extending horizontally elongated outer edge reinforcement portions 13 vertically. Furthermore, deck board 11 is provided at the center in the horizontal direction H2 with vertically elongated central reinforcement portion 15, which has vertical ribs 11A spaced closely together and has an upper surface covered by top plate 15T. Top plate 15T is also provided with a rectangular hole that is slightly smaller than the square surrounded by vertical ribs 11A and horizontal ribs 11B of vertically elongated central reinforcement portion 15.

[0023] As shown in Fig. 1, cylindrical grip receiving tubes 16 are formed integrally with horizontally elongated outer edge reinforcement sections 13 near the four corners of deck board 11, and anti-slip members 16G are housed inside them and protrude slightly from the upper surface of deck board 11. Also, as shown in Fig. 2, a slope 11G is formed on the outer edge of the underside of deck board 11, and a vertical display surface 11N is formed without slope 11G in part of the portion that serves as the entrance to fork insertion path 90. A sticker identifying the user or owner of pallet 10 can be affixed to display surface 11N.

[0024] The four areas of deck board 11 surrounded by the reinforcing portions (reference numerals 12, 13, 14, 15) described above form inner lattice portions 19 with larger square bars than the reinforcing portions. Each inner lattice portion 19 is integrally formed with a rectangular cylindrical grip receiving tube 17 at a lower position, and anti-slip members 17G are housed inside them and protrude slightly from the underside of deck board 11.

[0025] The girder sections 20, 30 of the pallet 10 are arranged in three rows and three columns at the four corners and the center of the outer edges of the four sides of the deck board 11 and at the center of the entire deck board 11, and protrude downward from the deck board 11. The girder sections 20, 30 are connected at their lower ends by a lower end connecting wall 40 only between adjacent girder sections 20, 30 in the horizontal direction H2. The lower end connecting wall 40 has a structure in which the entire upper surface of a group of ribs 40L (see FIG. 2) intersecting in a batten structure is covered by a top wall 40T (see FIG. 1). As shown in FIG. 1, the center of the top wall 40T in the width direction (vertical direction H1) forms a horizontal section 40S, and on both sides in the width direction, there are inclined oblique sections 40U that are bent downward from the horizontal section 40S and inclined. Furthermore, as shown in FIG. 2, cylindrical grip receiving tubes 46 are integrally formed in the ribs 40L of the four lower end connecting walls 40 located at both ends in the vertical direction H1, and an anti-slip member (not shown) can be accommodated inside them.

[0026] In the pallet 10 of this embodiment, a pair of forks of a hand lifter or a forklift can be inserted below the deck board 11 from any of the vertical direction H1 and horizontal direction H2. Here, when arranging a plurality of pallets 10 in a densely packed state, it is easier to transport each pallet 10 if the pallets 10 are arranged side by side in the short side direction of the pallets 10, so a pair of forks are inserted below the deck board 11 from the vertical direction H1. Therefore, in the pallet 10 of this embodiment, the girder parts 20 on both sides of a pair of fork insertion paths 90 when a pair of forks are inserted from the vertical direction H1 have a structure different from the conventional one in order to make the width of the pallet 10 compact.

[0027] That is, in this embodiment, the vertical direction H1 corresponds to the "first horizontal direction" in the claims, and the horizontal direction H2 corresponds to the "second horizontal direction" in the claims. In addition, when distinguishing between the girder parts 20, 30, the girder parts 20 on both sides of the pair of fork insertion paths 90 when inserting a pair of forks from the vertical direction H1 are referred to as the "side girder parts 20," and the girder part 30 between the pair of fork insertion paths 90 is referred to as the "center girder part 30."

[0028] The planar shape of the aforementioned anti-slip members 17G is an elongated rectangle, and the four anti-slip members 17G are arranged so as to be rotationally symmetric. In either case where the forks are inserted into the deck board 11 from the vertical direction H1 or from the horizontal direction H2, the anti-slip member 17G extending in the longitudinal direction of one fork and the anti-slip member 17G extending in the width direction of the other fork come into contact with each fork. The pallet 10 has a bilaterally symmetrical structure in both the vertical direction H1 and the horizontal direction H2, except for the anti-slip members 17G and the grip receiving tubes 17.

[0029] The following mainly describes in detail the structure of the girder parts 20, 30. Fig. 3(A) shows the planar cross-sectional shape of the girder parts 20, 30 at the ends in the vertical direction H1, and Fig. 3(B) shows the planar cross-sectional shape of the girder parts 20, 30 at the center in the vertical direction H1. As shown in these figures, the girder parts 20, 30 are both structured with reinforcing ribs 24, 34 in the cylindrical walls 25, 35. In addition, while the planar cross-sectional shape of the cylindrical wall 35 of the central girder part 30 is approximately square, the planar cross-sectional shape of the cylindrical wall 25 of the side girder part 20 is a rectangle that is longer in the vertical direction H1.

[0030] In order to guide the forks into a pair of fork insertion passages 90, the side walls (symbols 21, 31) of the cylindrical walls 25, 35 of the girder sections 20, 30 facing each other across the fork insertion passage 90 in the cylindrical walls 25, 35 of the girder sections 20, 30 arranged at the ends of the vertical direction H1 are curved so as to move away from each other at the ends on the outer surface side of the pallet 10.

[0031] The length and width L2, L3 of the square flat cross-sectional shape of the tubular wall 35 of the central girder 30 and the length L2 in the vertical direction H1 of the rectangular flat cross-sectional shape of the tubular wall 25 of the side girder 20 are the same, for example, both being 80 to 150 mm. Moreover, the length L1 in the horizontal direction H2 of the side girder 20 is 1 / 5 to 1 / 3 of the length L2 in the vertical direction H1, for example, 50 mm or less (preferably 40 mm or less, and even more preferably 30 mm or less).

[0032] In addition, the reinforcing rib 34 of the central girder 30 has a cross-shaped cross section and divides the inside of the cylindrical wall 35 into two equal parts in both the vertical direction H1 and the horizontal direction H2, whereas the reinforcing rib 24 of the side girder 20 divides the inside of the cylindrical wall 25 into two equal parts only in the vertical direction H1. The cylindrical wall 35 of the central girder 30 is provided with a reinforcing rib 35L protruding from the inner surface of the cylindrical wall 35.

[0033] As shown in Fig. 1, the cylindrical wall 35 of the central girder 30 has a structure in which the upper surface is closed by the above-mentioned top plate 15T and the entire lower surface is open. In contrast, as shown in Figs. 4 and 5, the cylindrical wall 25 of the side girder 20 has an entirely open upper surface and an entirely open lower surface, penetrating vertically.

[0034] Also, as shown in Figures 4 and 5, of the inward side wall 21 and the outward side wall 22 which face each other in the horizontal direction H2 of the tubular wall 25 of the side girder 20, the outward side wall 22 has a flat plate shape, whereas the inward side wall 21 has a shape in which the middle part in the vertical direction is hollowed out by the fork insertion passage 90, and the detailed shape differs between the side girder 20 located at the end in the vertical direction H1 and the side girder 20 located in the center.

[0035] That is, as shown in Fig. 4, in the side girder portion 20 at the end in the vertical direction H1, the vertical middle portion of the inward side wall 21 is bent in a crank shape to correspond to the fork insertion passage 90. The inward side wall 21 has a first vertical portion 21A that is parallel to the outward side wall 22 above the fork insertion passage 90, a horizontal portion 21B that is bent at a right angle from the lower end of the first vertical portion 21A toward the outward side wall 22, a second vertical portion 21C that is bent at a right angle substantially vertically downward from the end of the horizontal portion 21B on the outward side wall 22 side, an arc portion 21D that is curved from the lower end of the second vertical portion 21C toward the side away from the outward side wall 22, and a third vertical portion 21E that is bent vertically downward from the end of the arc portion 21D away from the outward side wall 22 and is located directly below the first vertical portion 21A. The arc portion 21D gives the lower corner of the fork insertion path 90 on the side girder 20 side a rounded chamfered shape, and the horizontal portion 21B and the second vertical portion 21C give the upper corner of the fork insertion path 90 on the side girder 20 side a pin angle shape.

[0036] 5, the side girder 20 at the center in the vertical direction H1 has a first vertical portion 21A similar to the side girder 20 at the end, a curved portion 21F that curves downward from the lower end of the first vertical portion 21A toward the outward side wall 22, and a second vertical portion 21G that extends from the lower end of the curved portion 21F to the lower end of the side girder 20. The curved portion 21F gives the fork insertion passage 90 an R-chamfered upper corner on the side girder 20 side.

[0037] In addition, the end of the upper wall 40T of the lower end connecting wall 40 in the horizontal direction H2 is provided with an arc-shaped curved, rising arc portion 42 that is connected to the second vertical portion 21G so that the lower corners of the fork insertion path 90 on the side girder 20 side also have an R-chamfered shape. Similarly, with respect to the central girder 30 at the center and end in the vertical direction H1, an arc portion 41 is provided that rises from the upper wall 40T and is connected to the side wall 31 of the central girder 30 so that the lower corners of the fork insertion path 90 on the central girder 30 side have an R-chamfered shape.

[0038] Furthermore, with regard to the central girder 30 in the center of the vertical direction H1, as shown in Figure 5, a corner protrusion 43 protrudes from the side wall 31 of the central girder 30 so that the upper corner of the fork insertion passage 90 on the central girder 30 side is also round-chamfered, and corner extensions 11C extend from multiple horizontal ribs 11B included in the horizontal reinforcement portion 12, forming a round-chamfered surface 11D continuous with the corner protrusions 43 and the corner extensions 11C.

[0039] On the other hand, with regard to the central girder 30 at the end in the vertical direction H1, as shown in Figure 4, the upper corner of the fork insertion passage 90 on the central girder 30 side is pin-angled, and does not have the above-mentioned corner protrusion 43 and corner extension 11C, and the lower surfaces of the multiple horizontal ribs 11B included in the horizontal reinforcement portion 12 are perpendicular to the side wall 31 of the central girder 30.

[0040] As shown in FIG. 4, the inner surface of the side girder 20 at the end in the vertical direction H1 has an inner surface protrusion 29 that protrudes slightly from the inner surface of the side girder 20 at approximately the center in the vertical direction. Also, as shown in FIG. 5, the inner surface of the side girder 20 at the center in the vertical direction H1 has an inner surface protrusion 29 that protrudes slightly from the inner surface of the side girder 20 at a position lower than the approximately center in the vertical direction. These inner surface protrusions 29 are formed by the gap between the joint surfaces of the first molding protrusion and the second molding protrusion, which will be described later. That is, the inner surface protrusion 29 is the parting line between the dies on each side girder 20 side. Also, in FIG. 4 and FIG. 5, the part of the inner surface of the inward side wall 21 that appears to be parallel to the vertical direction at first glance is inclined so as to gradually move away from the inner surface of the outward side wall 22 as it moves upward and downward from the inner surface protrusion 29.

[0041] The structure of the pallet 10 of this embodiment has been described above. The pallet 10 of this embodiment is manufactured using a resin injection mold. The injection mold includes, although not shown, a first and a second mold that are opened and closed in the vertical direction of the pallet 10, a pair of first slide molds that approach and separate from each other in the vertical direction H1, mold the outer side surface facing the vertical direction H1 of the pallet 10, and have a pair of square pillars to mold the inner surfaces of a pair of fork insertion passages 90, and a pair of second slide molds that approach and separate from each other in the horizontal direction H2, mold the opposing surfaces of the side beams 20 adjacent to each other in the vertical direction H1, etc. Then, the inner surfaces of the beams 20, 30 are molded by molding protrusions that protrude from the first and second molds in the vertical direction of the pallet 10.

[0042] Specifically, the molding protrusion (not shown) that molds the inner surface of the central girder 30 (hereinafter referred to as the "molding protrusion for central girder 30") has a structure in which rectangular columns are arranged in two rows and two columns, in accordance with the shape of the portion of the central girder 30 that does not have a resin wall shown in Fig. 3. Also, since the upper surface of the tubular wall 35 of the central girder 30 is closed by the top plate 15T, the molding protrusion for the central girder 30 protrudes from one of the first or second molds and has a length that extends from the lower end of the central girder 30 to the underside of the top plate 15T.

[0043] In contrast, the molded protrusion (not shown) that molds the inner surface of the side girder 20 (hereinafter referred to as the "molded protrusion for side girder 20") has a structure in which two rectangular pillars are arranged side by side, in accordance with the shape of the portion of the side girder 20 that does not have a resin wall shown in FIG. 3, and the rectangular pillars of the molded protrusion for side girder 20 are thinner than the rectangular pillars of the molded protrusion for central girder 30. Furthermore, taking advantage of the fact that the tubular wall 25 of the side girder 20 is penetrated vertically, the molded protrusion for side girder 20 consists of a first molded protrusion protruding from a first mold and a second molded protrusion protruding from a second mold. The tip faces of the first and second molded protrusions are joined together at a vertical midpoint of the side girder 20, and the aforementioned inner surface protrusion 29 is formed as a trace of this. In this way, the molded protrusions for the side girders 20 are divided into the first molded protrusion and the second molded protrusion in the opening and closing direction of the first and second dies, and are therefore shorter than the molded protrusions for the central girders 30. As a result, the molded protrusions for the side girders 20 are thinner than the molded protrusions for the central girders 30, but deformation due to resin pressure is suppressed. Moreover, since the side girders 20 have a structure in which the middle part in the up-down direction is hollowed out by the fork insertion passage 90, at the side girders 20 in the center in the vertical direction H1, both the first molded protrusion and the second molded protrusion have a structure in which the base end side is thicker than the tip side, which also suppresses deformation of the first molded protrusion and the second molded protrusion due to resin pressure. In addition, in the side beam 20 at the end in the vertical direction H1, one of the first and second molded protrusions has a structure in which the base end is thicker than the tip, but their joining surfaces are arranged so that the one is shorter than the other. This also balances the strength of the first and second molded protrusions, suppressing their deformation due to resin pressure.

[0044] In this way, the pallet 10 of this embodiment has a cylindrical structure in which the side beams 20 penetrate vertically, so that the molding protrusions for molding the inner surface of the side beams 20 can be divided into a first molding protrusion and a second molding protrusion that face each other in the mold opening direction of the injection molding die, and can be made shorter than in the past. As a result, even in the case of a pallet 10 having a side beam 20 that is thinner than usual, deformation of the first and second molding protrusions that mold the inside of the side beams 20 due to resin pressure is suppressed. Moreover, since the middle position of the inward side wall 21 is closer to the outward side wall 22 than both ends in the vertical direction so that the distance between the inward side wall 21 and the outward side wall 22 that face each other in the horizontal direction H2 of each side beam 20 becomes narrower at the middle position than both ends in the vertical direction of the side beams 20, the first molding protrusion and the second molding protrusion can be made thicker at the base end side than the tip end side. As a result, the bending strength of the first molding protrusion and the second molding protrusion is increased, and deformation of the molding protrusions due to resin pressure is suppressed. Furthermore, by suppressing deformation of the molded protrusions due to resin pressure, shape quality is stable even for pallets with side beams 20 having a width of 50 mm or less, such as the pallet 10 of this embodiment. Also, because the width of the side beams 20 of the pallet 10 is 50 mm or less, the overall width of the pallet 10 (width in the horizontal direction H2) can be reduced by 100 mm or more compared to general conventional pallets 10 with a width of 100 mm or more, making it possible to efficiently lay out the pallets 10.

[0045] Furthermore, in the pallet 10 of this embodiment, the fork insertion passage 90 is inserted into the side girder 20 to a position where the middle region of the inward sidewall 21 located to the side of the fork insertion passage 90 is offset toward the outward sidewall 22 from the upper region located at the top, thereby reducing the width of the pallet 10. Also, since a curved portion 21F is provided between the upper region and middle region of the inward sidewall 21 so that the upper corner on the side girder 20 side has an R-chamfered shape, water is less likely to accumulate between the middle region and upper region of the inward sidewall 21, and stress concentration is also prevented.

[0046] In the pallet 10 of this embodiment, the upper corners of a pair of fork insertion passages 90 when viewed from the vertical direction H1 have an R-chamfered shape in the middle of the vertical direction H1, while they have a pin-angle shape at both ends in the vertical direction H1. Therefore, compared to a case in which the upper corners of the fork insertion passages 90 are all R-chamfered, there are fewer undercuts and the mold structure is simpler.

[0047] [Other embodiments] (1) In the above embodiment, the vertical middle portion of the side girder 20, which has a width of 50 mm or less, is carved out by the fork insertion passage 90. However, the vertical middle portion of a side girder, which has a width of 50 mm or more (e.g., 100 mm), may also be carved out by a fork insertion passage to reduce the overall width of the pallet.

[0048] (2) In the above embodiment of the pallet 10, only the lower ends of adjacent girder sections 20, 30 in the horizontal direction H2 are connected by the lower end connecting wall 40, but the lower ends of adjacent girder sections in the vertical direction H1 may also be connected by a lower end connecting wall, or the entire underside of the pallet may be covered by a single plate.

[0049] (3) In the above embodiment, the pallet 10 has a rectangular planar shape, but it may have a square planar shape.

[0050] (4) In the pallet 10 of the above embodiment, the side girder 20 has a shape carved out by the fork insertion passage 90, but in the pallet 10 of the above embodiment, the side girder 20 does not have to have a shape carved out by the fork insertion passage 90.

[0051] (5) In the pallet 10 of the above embodiment, a pair of fork insertion paths 90 were defined by a plurality of central beams 30 in the center of the horizontal direction H2 of the pallet 10. However, the central beams 30 may be excluded from the center of the horizontal direction H2, and a pair of fork insertion paths 90 may not be defined.

[0052] (6) In the pallet 10 of the above embodiment, the pair of forks can be inserted not only from the vertical direction H1 but also from the horizontal direction H2, but the pair of forks may be inserted only from the vertical direction H1. Specifically, the pair of side beams 20 may extend over the entire vertical direction H1 at both ends of the pallet 10 in the horizontal direction H2, so that the pair of forks can be inserted only from the vertical direction H1. Even in this case, the central beam 30 may be removed from the central portion in the horizontal direction H2, so that the pair of fork insertion paths 90 are not defined.

[0053] In addition, although this specification and drawings disclose specific examples of the technology included in the scope of the claims, the technology described in the claims is not limited to these specific examples, but includes various modifications and variations of the specific examples, as well as parts of the specific examples taken alone. [Explanation of symbols]

[0054] 10 Palettes 11 Deck Board 20 Side girder 21 Inward facing side wall 21F Curved section 22 Outward facing sidewall 30 Central girder 30,40 digit part 31 Side wall 40 Lower connecting wall 90 Fork insertion path H1 Vertical (first horizontal) H2 Horizontal (second horizontal)

Claims

1. A resin pallet in which a number of side girders located on both sides of a pair of fork insertion paths when a pair of forks of a hand lifter or forklift are inserted between a number of girders from a first horizontal direction form a cylindrical structure that penetrates in the vertical direction and has a width of 50 mm or less in a second horizontal direction perpendicular to the first horizontal direction, and in which the vertical midpoint of the inward side wall is closer to the outward side wall than the end points so that the distance between the inward side wall and the outward side wall facing each other in the second horizontal direction of each of the side girders is narrower at the midpoint than at the vertical end points.

2. 2. A pallet according to claim 1, wherein an intermediate region of said inward side wall, which is located to the side of said fork insertion passage, is offset toward said outward side wall from an upper region located above said inward side wall.

3. A pallet as described in claim 2, further comprising a curved portion between the upper region and the middle region of the inward side wall so that the upper corner of the fork insertion path on the side girder side when viewed from the first horizontal direction has an R-chamfered shape.

4. The plurality of beams are arranged in three rows and three columns, and lower ends of adjacent beams in the second horizontal direction are connected to each other by a lower end connecting wall, The upper corners of the pair of fork insertion paths as viewed from the first horizontal direction have an R-chamfered shape in the middle portion in the first horizontal direction, while having a pin-angle shape at both ends in the first horizontal direction; 4. A pallet as described in claim 2 or 3, wherein the lower corners of the pair of fork insertion paths as viewed from the first horizontal direction are rounded at the middle and both ends in the first horizontal direction.

5. Only one of the upper and lower sides of the inward side wall relative to a middle region located on the side of the fork insertion passage is offset away from the outward side wall. A pallet as claimed in any one of claims 1 to 4, wherein a parting line of a mold is located inside the side girder portion, either above or below the middle region.

6. A resin pallet having a plurality of side girders located on both sides of a pair of fork insertion paths when a pair of forks of a hand lifter or forklift are inserted between the plurality of girders from a first horizontal direction, the side girders penetrating in the vertical direction and forming a cylindrical structure with a width of 50 mm or less in a second horizontal direction perpendicular to the first horizontal direction, and the middle portion in the vertical direction being carved out by the fork insertion paths.

7. A method for manufacturing a pallet using a resin injection mold, the method comprising the steps of: manufacturing a pallet having a cylindrical structure in which a plurality of side girders, each located on both sides of a pair of fork insertion paths when a pair of forks of a hand lifter or a forklift are inserted between a plurality of girders from a first horizontal direction, penetrate the pallet in the up-down direction; and having a width of 50 mm or less in a second horizontal direction perpendicular to the first horizontal direction, the method comprising the steps of: A manufacturing method for a pallet, in which a first molding protrusion protruding from a first mold and a second molding protrusion protruding from the second mold, which are opposed to each other in the mold opening direction among the injection molding molds, are made to have a base end thicker than the tip in order to form the inner surface of the side girder, and the tip surfaces of the first molding protrusion and the second molding protrusion are abutted against each other at a vertical midpoint within the side girder.

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