Box-shaped container

Abstract

To provide a box-shaped container that is resistant to damage to the bottom.SOLUTION: A box-shaped container 10 has the following configuration. A bottom 12 has an overall grid structure in which multiple beams 16 extending vertically and horizontally cross each other. Intersections of the beams 16 are denoted as intersections 22. There are provided first intersections 22A of a cross-shaped structure and second intersections 22B of a grid structure having a higher resin density than the first intersections 22A. A proportion of the second intersections 22B is higher in a bottom central part 12E than in a bottom peripheral part 12F.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to a box-shaped container made of resin. [Background technology]

[0002] Conventionally, as this type of box-shaped container, there is known one having a bottom structure in which multiple beams cross in a lattice pattern, and having legs only on the outer edge of the bottom (12) (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-171314 A (Figs. 1 and 3) Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-mentioned conventional box-shaped container, it is required to make the bottom less susceptible to damage. [Means for solving the problem]

[0005] The box-shaped container of claim 1, which has been made to achieve the above-mentioned object, is a box-shaped container made of resin having a bottom structure in which a number of beams intersect in a lattice pattern and legs only on the outer edge of the bottom, and the intersections between the beams are a first intersection and a second intersection having a higher resin density than the first intersection, and in the region of the bottom that is inside the outer edge, the central part of the bottom, which is the bottom center, has a higher proportion of the second intersection than the bottom peripheral parts other than the bottom center. Effect of the Invention

[0006] In a box-shaped container that has legs only on the outer edge of the bottom, the center of the bottom may bend downward and break when a heavy load is placed inside. In contrast, in the box-shaped container of claim 1, the center of the bottom, which is prone to breakage, has a higher resin density at the intersections between the beams than the peripheral parts of the bottom other than the center of the bottom, so the center of the bottom is reinforced and the bottom is less likely to break. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a perspective view of a box-shaped container according to a first embodiment. [Diagram 2] FIG. 2 is a perspective view of the box-shaped container in a folded state. [Diagram 3] FIG. 3 is a perspective view of the pallet base. [Figure 4] FIG. 4 is a perspective view of a box-shaped container with its long side wall in a half-open position. [Diagram 5] FIG. 5 is a perspective view of the bottom side of the pallet base. [Figure 6] FIG. 6 is a side cross-sectional view near the center of the bottom. [Figure 7] FIG. 7 is an enlarged perspective view of the underside near the center of the bottom. [Figure 8] FIG. 8 is a side cross-sectional view near the center of the bottom. [Figure 9] FIG. 9 is an enlarged perspective view of the vicinity of the center of the bottom. [Figure 10] FIG. 10 is a perspective view of a pallet base according to a modified example. [Figure 11] FIG. 11 is a perspective view of the lower surface side of a pallet base according to a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] [First embodiment] A box-shaped container 10 according to a first embodiment will be described below with reference to Fig. 1 to Fig. 9. The box-shaped container 10 shown in Fig. 1 is a so-called "foldable box pallet" that is configured by rotatably assembling a pair of short side walls 30, 30 and a pair of long side walls 40, 40 to the outer edge of a pallet base 11, and can be transformed into an assembled state shown in Fig. 1 and a folded state shown in Fig. 2. All of the container components constituting the box-shaped container 10, such as the pallet base 11, the short side walls 30, and the long side walls 40, are injection-molded products of resin containing long glass fibers, for example.

[0009] As shown in Figure 3, the pallet base 11 has a structure in which girders 13 (corresponding to "legs") protrude from the four corners of the underside of a bottom 12 which has a rectangular planar shape, and these girders 13 form a space below the bottom 12 into which the forks of a forklift can be inserted.

[0010] A pair of long side banks 14, 14 protrude from the outer edges of a pair of long sides on the upper surface of the bottom 12, and a pair of short side banks 15, 15 protrude from the outer edges of a pair of short sides. The short side banks 15 are higher than the long side banks 14. A plurality of hinge recesses 15U, 14U are formed in the short side banks 15 and the long side banks 14, and the hinge recesses 15U, 14U are connected to the hinge portions 31, 45 of the short side wall 30 and the long side wall 40 (see FIG. 4). Each hinge recess 15U, 14U is open to the upper surface and the inner surface, and has restricting walls 15T, 14T on both inner sides.

[0011] As shown in FIG. 1, the short side wall 30 has a lattice structure including a plurality of horizontally extending lateral members 34 and a plurality of vertically extending vertical members 35, which are arranged in a crossing state. The plurality of horizontal members 34 form a square groove structure in which a pair of vertically opposing groove side walls 34A, 34A is closed by a groove bottom wall 34B, and are arranged vertically at regular intervals. Similarly, the plurality of vertical members 35 form a square groove structure in which a pair of groove side walls 35A, 35A is closed by a groove bottom wall 35B, and are arranged horizontally at regular intervals. The groove bottom wall 34B of the horizontal member 34 is arranged on the outer surface side of the short side wall 30, while the groove bottom wall 35B of the vertical member 35 is arranged on the inner surface side of the short side wall 30, and at the intersection between the two, the groove bottom wall 35B of the vertical member 35 is divided.

[0012] As shown in Fig. 4, a plurality of hinge portions 31 are provided on the underside of the short side wall 30. The hinge portion 31 has a hinge arm 31A that hangs down from the underside of the short side wall 30, and a hinge protrusion (not shown) that protrudes laterally from the lower end of the hinge arm 31A. With the hinge protrusion engaged with the regulating wall 15T, the hinge portion 31 is received in the hinge recess 15U of the short side bank portion 15, so that the short side wall 30 becomes rotatable with respect to the pallet base 11, and is changed between an upright position standing on the short side bank portion 15 (see Fig. 1) and a folded position lying down on the bottom portion 12 of the pallet base 11 (see Fig. 2).

[0013] As shown in FIG. 1, the long side wall 40 is formed by connecting an upper long side wall 41 and a lower long side wall 42 with hinges. The upper long side wall 41 and the lower long side wall 42, like the short side wall 30, have a lattice structure in which a plurality of horizontal members 43 and a plurality of vertical members 44 cross each other. The horizontal member 43 has a square groove structure in which a pair of groove side walls 43A, 43A facing each other in the vertical direction is closed by a groove bottom wall 43B, and the vertical member 44 has a square groove structure in which a pair of groove side walls 44A, 44A is closed by a groove bottom wall 44B. The groove bottom wall 43B of the horizontal member 43 is disposed on the outer surface side of the long side wall 40, while the groove bottom wall 44B of the vertical member 44 is disposed on the inner surface side of the long side wall 40, and the groove bottom wall 44B of the vertical member 44 is divided at the intersection between the two.

[0014] As shown in FIG. 4, the lower surface of the lower long side wall 42 is provided with a plurality of hinge portions 45, similar to the short side wall 30. The hinge portion 45 has a hinge arm 45A that hangs down from the lower surface of the lower long side wall 42, and a hinge protrusion (not shown) that protrudes laterally from the lower end of the hinge arm 45A. With the hinge protrusion engaged with the regulating wall 14T, the hinge portion 45 is received in the hinge recess 14U of the long side bank portion 14, so that the long side wall 40 becomes rotatable with respect to the pallet base 11, and is changed to an upright position (see FIG. 1) in which the long side wall 40 stands on the long side bank portion 14, and a folded position (see FIG. 2) in which the long side wall 40 is folded in two and collapsed on the bottom portion 12 of the pallet base 11. The long side wall 40 can also be changed from the upright position to a half-open position (see FIG. 4) in which only the upper long side wall 41 is rotated outward.

[0015] 1, an engagement slider 50 is slidably attached to the upper long side wall 41. The engagement slider 50 slides left and right between an engagement position where it engages with the upper end of the short side wall 30 and a release position where the engagement is released. When the engagement slider 50 is disposed at the engagement position, the short side wall 30 and the long side wall 40 are held in an upright position.

[0016] Next, the bottom 12 of the pallet base 11 will be described in detail. As shown in Fig. 3, the bottom 12 generally has a lattice structure in which a plurality of beams 16 extending vertically and horizontally cross each other, and the portion surrounded by the beams 16 forms a through hole 20. As shown in Figs. 5 and 6, each beam 16 is groove-shaped and includes a pair of ribs 17 facing each other in the horizontal direction and a groove bottom wall 18 connecting the upper ends of the ribs 17. The groove bottom wall 18 of the beam 16 extending in the longitudinal direction (hereinafter referred to as "horizontal beam 16A") and the groove bottom wall 18 of the beam 16 extending in the lateral direction (hereinafter referred to as "vertical beam 16B") are flush with each other, and together they form the mounting surface within the box-shaped container 10.

[0017] As shown in Figs. 3 and 5, in the outer edge region 12A connecting the girder portions 13 of the bottom 12, the distance in the short side direction between the beams 16 extending in the longitudinal direction in each outer edge region 12A (the longitudinal direction of the box-shaped container 10 in the outer edge region 12A on the long side; the short side direction of the box-shaped container 10 in the outer edge region 12A on the short side) is shorter than the distance between the beams 16 in the inner region 12B on the inside of the outer edge region 12A. As a result, the through hole 20 arranged in the outer edge region 12A is narrower than the through hole 20 arranged in the inner region 12B. In the outer edge region 12A, the groove bottom wall 18 slightly protrudes into the through hole 20, so that the through hole 20 is slightly smaller than the portion surrounded by the rib 17 of the beam 16. Furthermore, a plurality of through holes 21 are formed in positions aligned with the through holes 20 in the groove bottom wall 18 of the beam 16 extending in the longitudinal direction in the outer edge region 12A.

[0018] In this embodiment, the inner region 12B has a size including 11 through holes 20 in the longitudinal direction and 9 through holes 20 in the lateral direction. Note that flat portions 12C in which no through holes 20, 21 are formed are provided near the four corners of the bottom 12. The longitudinal range of this flat portion 12C of the bottom 12 is the two through holes 20 at the ends of the inner region 12B, and the lateral range is from the through holes 20 at the ends of the inner region 12B to the long side bank portion 14.

[0019] As shown in Figs. 5 and 7, the box-shaped container 10 is provided with a first intersection 22A and a second intersection 22B having different structures as intersections 22 between beams 16. The second intersection 22B has a lattice structure in which a pair of ribs 17 of the horizontal beam 16A and a pair of ribs 17 of the vertical beam 16B are perpendicular to each other. In the first intersection 22A, the intersections of the ribs 17 of the horizontal beam 16A and the ribs 17 of the vertical beam 16B are diagonally connected to each other. In other words, the first intersection 22A has a cross-hatched structure in which a pair of ribs 17 of the horizontal beam 16A and a pair of ribs 17 of the vertical beam 16B cross each other in a cross-hatched manner. For example, if the groove width of both the horizontal beam 16A and the vertical beam 16B is 1 cm, the second intersection 22B will have four 1 cm ribs arranged lengthwise and widthwise, whereas the first intersection 22A will have two 1.4 cm ribs, so that the total length of the ribs of the second intersection 22B (4 cm) is longer than the total length of the ribs of the first intersection 22A (2.8 cm). This makes the resin density of the second intersection 22B greater than that of the first intersection 22A.

[0020] The second intersections 22B are arranged together in a part of the bottom center portion 12E, which is the center of the inner region 12B, and the other intersections 22 are the first intersections 22A. In detail, the intersections (total of eight) between the two longitudinal beams 16B in the center of the length of the inner region 12B and the four transverse beams 16A in the short direction are the second intersections 22B, and all the other intersections are the first intersections 22A. As a result, in the inner region 12B, the bottom center portion 12E has a higher proportion of the second intersections 22B than the bottom peripheral portion 12F other than the bottom center portion 12E.

[0021] In this embodiment, in the inner region 12B, a region including the central five rows and five columns of through-holes 20 is defined as a bottom central portion 12E, and the region other than the bottom central portion 12E is defined as a bottom peripheral portion 12F.

[0022] In addition, in the portion of the inner region 12B excluding the four corners, a connecting rib 17L that connects a pair of ribs 17 is arranged between the intersections 22 of each beam 16. Among these connecting ribs 17L, the connecting rib 17L arranged in the bottom center portion 12E of the inner region 12B is thicker than the connecting rib 17L arranged in the bottom peripheral portion 12F. Note that the connecting ribs 17L are also arranged in the beams 16 of the outer edge region 12A at multiple locations (four locations each in this embodiment) in the longitudinal center of each outer edge region 12A.

[0023] 6 and 7, a part of the bottom central portion 12E is provided with a lower end protrusion 24 that protrudes from the lower end of the beam 16 into the inside of the through hole 20. In detail, the bottom 12 is provided with a plurality of angular tube portions 23 that are made up of the ribs 17 of the beams 16 and surround the through hole 20. The lower end protrusions 24 protrude into the inside of the through hole 20 from the entire lower end circumference of the angular tube portions 23 that are arranged in a cross shape in a row of five each in the center of the bottom central portion 12E. The protrusion amount of the lower end protrusions 24 is about half the plate thickness of the angular tube portions 23.

[0024] In addition, in another part of the bottom center portion 12E, an upper end protrusion 25 is provided that protrudes from the upper end of the beam 16 toward the inside of the through hole 21. In detail, the upper end protrusion 25 is arranged on both sides (both sides in the short direction of the box-shaped container 10) of the angular tube portions 23 at both ends in the longitudinal direction (longitudinal direction of the box-shaped container 10) of the angular tube portions 23 arranged in a cross shape having the lower end protrusion 24. The upper end protrusion 25 extends from two sides of the upper ends of the angular tube portions 23 that face each other in the longitudinal direction of the box-shaped container 10 so as to approach each other. The protrusion amount of the upper end protrusion 25 is approximately the same as the plate thickness of the angular tube portion 23 (see FIG. 8). In addition, the upper end protrusion 25 is flush with the groove bottom wall 18 (see FIG. 9).

[0025] Next, the effects will be described. The box-shaped container 10 is used in the assembled state shown in Fig. 1, and is stored and transported with cargo contained therein. The box-shaped container 10 can also be moved by inserting the forks of a forklift under the bottom 12. Furthermore, since the girders 13 of the box-shaped container 10 are arranged only on the outer edge of the bottom 12 and not in the center of the bottom 12, the forks of the forklift can be inserted at an angle, and the box-shaped container can also be moved by the forklift even in narrow spaces.

[0026] Here, in a box-shaped container 10 in which the girder 13 is arranged only on the outer edge of the bottom 12 and not in the center of the bottom 12, if a heavy load is placed inside the box-shaped container 10, the center of the bottom may bend downward and become damaged.

[0027] In contrast, according to the box-shaped container 10 of the present embodiment, the intersections 22 between the beams 16 are provided with a first intersection 22A having a cross structure and a second intersection 22B having a crisscross structure in which the resin density is greater than that of the first intersection 22A, and the bottom central portion 12E has a higher proportion of the second intersection 22B than the bottom peripheral portion 12F, thereby reinforcing the bottom central portion 12E and making the bottom 12 less susceptible to damage.

[0028] Also, by increasing the proportion of the second intersection parts 22B in the bottom center part 12E, which is susceptible to breakage, rather than making the entire bottom part 12 the second intersection parts 22B, it is possible to effectively reinforce the bottom part 12 while preventing an increase in the amount of resin. This makes it possible to reduce the weight compared to a case in which the entire bottom part 12 is made up of the second intersection parts 22B, and also reduces manufacturing costs (particularly manufacturing costs during mass production).

[0029] Furthermore, in this embodiment, the bottom central portion 12E is further reinforced by the lower end protrusions 24 and the upper end protrusions 25, so that the bottom 12 is more difficult to break. Moreover, since the lower end protrusions 24 are arranged vertically and horizontally in a continuous cross shape, the bottom 12 is prevented from bending and distorting in both the vertical and horizontal directions, and damage to the bottom central portion 12E is more prevented. In addition, since the upper end protrusions 25 are flush with the groove bottom wall 18 of the beam 16, the placement surface in the box-shaped container 10 is expanded. In addition, the upper end protrusions 25 protrude from two opposing sides in the longitudinal direction of the box-shaped container 10 among the upper ends of the square tube portion 23 and extend in the lateral direction of the box-shaped container 10, so that the bending of the bottom 12 in the lateral direction is suppressed, and furthermore, since the opening width in the longitudinal direction of the box-shaped container 10 is narrowed, it is also effective against bending in the longitudinal direction.

[0030] In addition, in the box-shaped container 10, the pair of ribs 17 of the beam 16 are connected by the connecting rib 17L, which further reinforces the bottom 12. Moreover, the connecting rib 17L in the bottom center portion 12E is thicker than the connecting rib 17L in the bottom peripheral portion 12F, so that the bottom center portion 12E is effectively reinforced.

[0031] [Other embodiments] The present invention is not limited to the above-described embodiments. For example, the embodiments described below are also included in the technical scope of the present invention. Furthermore, in addition to the embodiments described below, various modifications can be made without departing from the spirit of the present invention.

[0032] The box-shaped container 10 in the above embodiment is a foldable box pallet, but it may be a non-foldable box pallet. It does not have to be transported by a forklift. The upper plate of a pallet in which the beams 13 are arranged only on the outer edge and which can be transported by a forklift may have a structure like the bottom plate 12, and a restricting protrusion capable of restricting the movement of cargo may be provided on the outer periphery of the upper plate of the pallet (the restricting protrusion corresponds to a side wall, and the structure corresponds to a box-shaped container). Although not included in the scope of the claims, the upper plate of a normal pallet that is not a box-shaped container may have a structure like the bottom plate 12.

[0033] In the above embodiment, the second intersection portion 22B was arranged only in the bottom central portion 12E, but the second intersection portion 22B may be arranged in both the bottom central portion 12E and the bottom peripheral portion 12F, and the proportion of the second intersection portion 22B may be higher in the bottom central portion 12E than in the bottom peripheral portion 12F.

[0034] The upper end protrusion 25 may be provided on two opposing sides in the short side direction, or may be provided on only one side of the angular tube portion 23, or may protrude from the entire circumference of the angular tube portion 23. The lower end protrusion 24 may be provided on only two opposing sides in the short side direction or long side direction of the angular tube portion 23, or may be provided on only one side.

[0035] The shapes of the first intersection portion 22A and the second intersection portion 22B are not limited to those in the above embodiment, and for example, the first intersection portion 22A may have a lattice structure and the second intersection portion 22B may have a structure that combines a lattice structure and a cross-hitch structure. Also, both may have the same shape, and the second intersection portion 22B may have a greater plate thickness.

[0036] The lower end protrusion 24 and the upper end protrusion 25 do not necessarily have to be provided.

[0037] As shown in Figures 10 and 11, the beam 16 may be configured to have a groove shape that is open downward in the bottom peripheral portion 12F and a groove shape that is open upward in the bottom central portion 12E. When a load is applied from above to a groove-shaped beam that is open downward and bends downward, it is conceivable that a crack will develop from the lower end of the groove side wall, but with the above configuration, the beam 16 in the bottom central portion 12E, which is prone to bending downward, is groove-shaped that is open upward, that is, the lower end of the groove side wall (rib 17) is connected by the groove bottom wall (groove bottom wall 18), so that cracks are less likely to develop in the beam 16 in the bottom central portion 12E, and damage to the bottom central portion 12E is prevented.

[0038] Each beam 16 may be in the form of a groove that is open upward. Also, the beam 16 does not have to be groove-shaped, and may have a structure in which, for example, a single rib hangs down from the center of the width of a plurality of vertical and horizontal groove bottom walls 18.

[0039] In the above embodiment, the "legs" were arranged at the four corners of the underside of the bottom 12, but they may also be configured to extend entirely or intermittently around the entire outer edge of the bottom 12, or they may be configured to extend along two opposing sides of the bottom 12.

[0040] In the above embodiment, the portion surrounded by the beams 16 forms the through hole 20, but the entire portion may be blocked by a ceiling wall that is flush with the groove bottom wall 18.

[0041] <Additional Notes> The following describes the feature groups extracted from the above-described embodiments, while indicating their effects, etc., as necessary. Note that, in the following, for ease of understanding, the corresponding configurations in the above-described embodiments are appropriately indicated in parentheses, but these feature groups are not limited to the specific configurations indicated in parentheses.

[0042] [Feature 1] A resin box-shaped container (10) having a bottom (12) with a structure in which a plurality of beams (16) cross each other in a lattice pattern, and having legs (13) only on an outer edge (12A) of the bottom (12), The intersection portion (22) between the beams (16) (16) includes a first intersection portion (22A) and a second intersection portion (22B) having a resin density greater than that of the first intersection portion (22A), A box-shaped container (10) in which, in a region (12B) of the bottom (12) that is inside the outer edge portion (12A), the central portion, i.e., a bottom central portion (12E), has a higher proportion of the second intersection portion (22B) than the bottom peripheral portion (12F) other than the bottom central portion (12E).

[0043] In a box-shaped container having legs only on the outer edge of the bottom, it is considered that the center of the bottom will bend downward and break when a heavy load is placed inside. In contrast, according to the box-shaped container of feature 1, the resin density at the intersections between the beams in the bottom center, which is susceptible to breakage, is greater than that in the bottom peripheral portion other than the bottom center, so that the bottom center is reinforced and the bottom can be made less susceptible to breakage. In addition, by locally reinforcing the bottom center, which is susceptible to breakage, the amount of resin can be reduced, rather than reinforcing the entire bottom, and manufacturing costs (particularly manufacturing costs in mass production) can be reduced. Note that feature 1 also includes those in which the second intersection is not included in the bottom peripheral portion (i.e., the proportion of the second intersection in the bottom peripheral portion is 0).

[0044] [Feature 2] The beam (16) has a groove shape in which the upper ends of a pair of ribs (17) facing each other in the horizontal direction are connected to each other. A portion of the bottom portion (12) surrounded by the beam (16) forms a through hole (20), A box-shaped container (10) according to feature 1, wherein the bottom central portion (12E) is provided with a lower end protrusion (24) that protrudes from the lower end of the beam (16) toward the inside of the through hole (20).

[0045] According to the box-shaped container of feature 2, the beam in the center of the bottom is reinforced by the lower end protrusion, so that damage to the center of the bottom is more effectively prevented.

[0046] [Feature 3] The box-shaped container (10) according to feature 2, wherein the through holes (20) in which the lower end protrusions (24) are arranged are continuously arranged at least vertically and horizontally in a cross shape.

[0047] According to the box-shaped container of feature 3, the through holes with the lower end protrusions are continuously arranged vertically and horizontally in a cross shape, so that the center of the bottom is reinforced in a focused manner, and damage to the center of the bottom is more effectively prevented.

[0048] [Feature 4] The box-shaped container (10) according to feature 3, wherein an upper end protrusion (25) protruding from an upper end of the beam (16) to the inside of the through hole (20) is arranged in the bottom central portion (12E) adjacent to the through hole (20) in which the lower end protrusion (24) is arranged.

[0049] According to the box-shaped container of feature 4, since an upper end protrusion is further provided at the center of the bottom, damage to the center of the bottom is further prevented. In addition, the upper end protrusion widens the placement surface within the box-shaped container.

[0050] [Feature 5] The box-shaped container (10) according to feature 1, wherein the beam (16) is formed in a groove shape that is open downward at the bottom peripheral portion (12F) and in a groove shape that is open upward at the bottom central portion (12E).

[0051] When a load is applied from above to a groove-shaped beam that is open downwards and bends downwards, it is conceivable that cracks will develop from the lower end of the groove side wall. However, with a box-shaped container having feature 5, the beam in the center of the bottom, which is prone to bending downwards, has a groove shape that is open upwards. In other words, the lower ends of the groove side walls are connected by the groove bottom wall. As a result, cracks are less likely to develop in the beam in the center of the bottom, and damage to the center of the bottom is prevented.

[0052] [Feature 6] Each of the beams (16) has a pair of ribs (17) opposed to each other in the horizontal direction, The second intersection portion (22B) has a lattice structure in which a pair of the ribs (17) in the vertical and horizontal directions are perpendicular to each other, The box-shaped container (10) according to any one of claims 1 to 5, wherein the first intersection portion (22A) has a cross-connected structure in which a pair of the ribs (17) in the vertical and horizontal directions cross each other in a cross-connected manner.

[0053] In order to make the density of the resin at the second intersection greater than that at the first intersection, for example, the thickness of the rib at the second intersection may be greater than the thickness of the rib at the first intersection, or the total length of the ribs at the second intersection may be greater than the total length of the ribs at the first intersection. In the latter case, for example, the structure of Feature 6 may be used.

[0054] [Feature 7] Each of the beams (16) has a pair of ribs (17) opposed to each other in the horizontal direction, A connecting rib (17L) that connects the pair of ribs (17) is disposed at least partially between the intersections (22) of the beam (16), The box-shaped container (10) according to any one of claims 1 to 5, wherein the connecting rib (17L) in the bottom central portion (12E) is thicker than the connecting rib (17L) in the bottom peripheral portion (12F).

[0055] According to the box-shaped container of feature 7, the pair of ribs of the beam are connected by a connecting rib, so that the bottom is further reinforced. Moreover, the connecting rib at the center of the bottom is thicker than the connecting ribs at the bottom periphery, so that the center of the bottom is effectively reinforced. [Explanation of symbols]

[0056] 10 box container 12 Bottom 12A Peripheral area (periphery) 12B Inner area 12E Bottom center part 12F Bottom periphery 13 Girder (leg) 16 Beam 17 Ribs 17L connecting rib 18 Groove bottom wall 20 Through hole 22A First Intersection 22B 2nd Intersection 23 Square tube part 24 Lower end protrusion 25 Upper protrusion

Claims

1. A resin box-shaped container having a bottom structure in which a plurality of beams intersect in a lattice pattern and having legs only on the outer edge of the bottom, As an intersection portion between the beams, a first intersection portion and a second intersection portion having a resin density greater than that of the first intersection portion are provided, A box-shaped container in which, in a region of the bottom that is more inward than the outer edge, the central part, i.e., the bottom central part, has a higher proportion of the second intersection portion than the bottom peripheral parts other than the bottom central part.

2. The beam has a groove shape in which upper ends of a pair of ribs facing each other in the horizontal direction are connected to each other, A portion of the bottom portion surrounded by the beam forms a through hole, 2. The box-shaped container according to claim 1, wherein a lower end protrusion is provided at the center of the bottom, the lower end of the beam protruding inwardly from the through hole.

3. The box-shaped container according to claim 2 , wherein the through holes in which the lower end protrusions are disposed are continuously arranged at least vertically and horizontally in a cross shape.

4. A box-shaped container as described in claim 3, wherein an upper end protrusion extending from the upper end of the beam to the inside of the through hole is arranged in the through hole adjacent to the through hole in which the lower end protrusion is arranged in the center of the bottom.

5. 2. The box-shaped container according to claim 1, wherein the beams are formed in a groove shape that is open downward at the bottom peripheral portion and in a groove shape that is open upward at the bottom central portion.

6. Each of the beams has a pair of horizontally opposed ribs; The second intersection portion has a lattice structure in which a pair of the ribs in the vertical and horizontal directions are perpendicular to each other, 6. The box-shaped container according to claim 1, wherein the first intersection portion has a cross-connecting structure in which a pair of the ribs cross each other in a vertical and horizontal direction.

7. Each of the beams has a pair of horizontally opposed ribs; A connecting rib that connects the pair of ribs is disposed at least partially between the intersections of the beam, 6. The box-shaped container according to claim 1, wherein the connecting rib in the bottom central portion is thicker than the connecting rib in the bottom peripheral portion.

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