Floor panel

Abstract

To provide a floor panel capable of enhancing rigidity with respect to a load, such as shear force.SOLUTION: A floor panel 30 includes: a plurality of hollow plate members 100 laminated in a sheet thickness direction, each of which includes a core layer 110 where a plurality of columnar cells S are disposed side by side in a direction intersecting the sheet thickness direction, and two skin layers 120 and 130 respectively bonded to both surfaces in the sheet thickness direction of the core layer 110; and bonding layers 81 and 82 that respectively bond two hollow plate members 100 adjacent to each other in the sheet thickness direction.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a floor panel. [Background technology]

[0002] Patent Document 1 describes a hollow structure having a hollow structure inside. This hollow structure is sometimes used as a floor panel to be laid on the floor of a building because of its light weight and excellent strength. Specifically, the floor panel is placed with a gap between it and the actual floor of the building via multiple support legs. In this way, the multiple floor panels, together with the floor of the building, form a so-called double floor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2022-140958 A Summary of the Invention [Problem to be solved by the invention]

[0004] When equipment and furniture are installed on the floor panel, loads such as shear forces act in the thickness direction of the floor panel. For this reason, it is desirable for the floor panel to have high rigidity against loads such as shear forces. [Means for solving the problem]

[0005] Means for solving the above problems will be described below. The floor panel that solves the above problem is a plate-shaped floor panel that includes a core layer in which a number of columnar cells are arranged side by side in a direction intersecting the plate thickness direction, and two skin layers that are joined to both sides of the core layer in the plate thickness direction, and is made of a number of hollow plate materials that are stacked in the plate thickness direction, and a joining layer that joins two of the hollow plate materials that are adjacent to each other in the plate thickness direction.

[0006] The floor panel that solves the above-mentioned problem is a board-shaped floor panel comprising a first hollow board and a second hollow board having a core layer in which a number of columnar cells are arranged side by side in a direction intersecting the board thickness direction and two skin layers respectively joined to both sides of the core layer in the board thickness direction, a foamed resin or wooden base material laminated between the first hollow board and the second hollow board in the board thickness direction, a first bonding layer bonding the first hollow board to the base material, and a second bonding layer bonding the second hollow board to the base material. Effect of the Invention

[0007] The floor panel can increase its rigidity against loads such as shear force. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a side view of a double floor structure. [Diagram 2] FIG. 2 is an exploded perspective view of the floor panel. [Diagram 3] FIG. 3 is a cross-sectional view of a floor panel. [Figure 4] FIG. 4(a) is a cross-sectional perspective view of a hollow plate material, FIG. 4(b) is a cross-sectional schematic view along the β-β line, and FIG. 4(c) is a cross-sectional schematic view along the γ-γ line. [Diagram 5] Figure 5(a) is a partial oblique view of the sheet material that constitutes the core layer, Figure 5(b) is a partial oblique view showing the state in the middle of folding the sheet material, and Figure 5(c) is a partial oblique view showing the state after folding the sheet material. [Figure 6] FIG. 6 is a cross-sectional view of a modified floor panel. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, one embodiment of a floor panel will be described with reference to the drawings. <Configuration of this embodiment> 1, the double floor structure 10 includes a plurality of support legs 20 and a plurality of floor panels 30. The double floor structure 10 is constructed on a floor FL of, for example, an office, a server room, or the like.

[0010] <Support leg 20> The support leg 20 includes a plate-shaped base 21, a rod-shaped support 22, and a plate-shaped pedestal 23. The base 21 is a portion fixed to a floor FL of a building. The base 21 may be fixed to the floor FL of the building using an adhesive or a fastening member such as a bolt. The support 22 extends upward from the base 21. It is preferable that the length of the support 22 is adjustable. The pedestal 23 is fixed to the tip of the support 22. The plate thickness direction of the pedestal 23 coincides with the axial direction of the support 22. The pedestal 23 may be formed in a circular plate shape or a rectangular plate shape.

[0011] <Floor Panel 30> 1 to 3, the floor panel 30 has a rectangular plate shape. The floor panel 30 includes a laminated structure 40, a first cover 50, a second cover 60, and two second bonding layers 71, 72.

[0012] <Laminated structure 40> 3, the laminated structure 40 includes three hollow plate materials 100 and two first bonding layers 81, 82. The three hollow plate materials 100 include a first hollow plate material 101, a second hollow plate material 102, and a third hollow plate material 103 made of synthetic resin.

[0013] <Structure of hollow plate material 100> As shown in FIG. 4(a), the hollow plate material 100 is composed of a core layer 110 and skin layers 120, 130 joined to both main surfaces of the core layer 110 so as to cover the entire core layer 110.

[0014] As shown in Figures 5(a) to 5(c), the core layer 110 is formed by folding one synthetic resin sheet material 200 molded into a predetermined shape. As shown in Figure 4(a), the core layer 110 is composed of blocking walls 111, 112 that block the cells S on both main surface sides of the core layer 110, and side walls 113 that are erected between the blocking walls 111, 112 and partition the cells S into a hexagonal column shape. As described below, the blocking walls 111, 112 of the core layer 110 have a structure in which a one-layer structure and a two-layer structure are mixed, but in Figure 4(a), the blocking walls 111, 112 of the core layer 110 are shown as a one-layer structure.

[0015] As shown in Figures 4(b) and (c), the cells S formed inside the core layer 110 include a first cell S1 and a second cell S2 having different structures. As shown in Figure 4(b), in the first cell S1, a two-layered blocking wall 111 is provided on the upper part of the side wall 113. The layers of the two-layered blocking wall 111 are joined to each other. In addition, an opening (not shown) is formed in the two-layered blocking wall 111 due to thermal contraction of the synthetic resin during molding of the core layer 110. In the first cell S1, a one-layered blocking wall 112 is provided on the lower part of the side wall 113.

[0016] On the other hand, as shown in Fig. 4(c), in the second cell S2, a single-layered blocking wall 111 is provided on the upper part of the side wall 113. In the second cell S2, a two-layered blocking wall 112 is provided on the lower part of the side wall 113. The layers of the two-layered blocking wall 112 are joined to each other. An opening (not shown) is formed in the two-layered blocking wall 112 due to thermal contraction of the synthetic resin when the core layer 110 is molded.

[0017] 4(b) and (c), adjacent first cells S1 and adjacent second cells S2 are partitioned by sidewalls 113 having a two-layer structure. The two-layer sidewalls 113 have portions that are not heat-welded to each other in the center in the thickness direction of the core layer 110. Therefore, the internal space of each cell S of the core layer 110 communicates with the internal spaces of the other cells S through the two-layer sidewalls 113.

[0018] As shown in Fig. 4(a), the first cells S1 are arranged in a row along the X direction. Similarly, the second cells S2 are arranged in a row along the X direction. The rows of the first cells S1 and the rows of the second cells S2 are alternately arranged in the Y direction perpendicular to the X direction. The first cells S1 and the second cells S2 form a honeycomb structure as a whole in the core layer 110.

[0019] The synthetic resin constituting the core layer 110 and the skin layers 120, 130 may be any conventionally known thermoplastic resin, such as polypropylene resin, polyamide resin, polyethylene resin, acrylonitrile-butadiene-styrene copolymer resin, acrylic resin, polybutylene terephthalate resin, etc. In this embodiment, the core layer 110 and the skin layers 120, 130 are made of polypropylene resin. The thermoplastic resin constituting the core layer 110 and the thermoplastic resin constituting the skin layers 120, 130 are preferably made of the same material. In this embodiment, the skin layers 120 and 130 have the same thickness.

[0020] <Method of manufacturing the hollow plate material 100> As shown in FIG. 5, the hollow plate material 100 is manufactured by forming a core layer 110 from a single sheet material 200 and bonding skin layers 120 and 130 to the core layer 110.

[0021] As shown in FIG. 5(a), the sheet material 200 is formed by molding one thermoplastic resin sheet into a predetermined shape. The sheet material 200 has band-shaped planar regions 210 and bulging regions 220 arranged alternately in the longitudinal direction (Y direction) of the sheet material 200. In the bulging region 220, a first bulging portion 221 having a cross section of a downward groove shape composed of an upper surface and a pair of side surfaces is formed over the entire extension direction (X direction) of the bulging region 220. Note that the angle between the upper surface and the side surface of the first bulging portion 221 is preferably 90 degrees, and as a result, the cross section of the first bulging portion 221 is a downward U-shape. The width of the first bulging portion 221 (the length of the short side of the upper surface) is set to be equal to the width of the planar region 210 and twice the length of the bulging height of the first bulging portion 221 (the length of the short side of the side surface).

[0022] In addition, in the bulging region 220, a plurality of second bulging portions 222, each of which has a cross-sectional shape that is a trapezoid obtained by bisecting a regular hexagon at its longest diagonal, are formed so as to be perpendicular to the first bulging portion 221. The bulging height of the second bulging portion 222 is set to be equal to the bulging height of the first bulging portion 221. In addition, the interval between adjacent second bulging portions 222 is equal to the width of the upper surface of the second bulging portion 222.

[0023] The first bulging portion 221 and the second bulging portion 222 are formed by partially bulging the sheet upwards by utilizing the plasticity of the sheet. The sheet material 200 can be formed from a single sheet by a known forming method such as vacuum forming or compression forming.

[0024] As shown in Fig. 5(a) and (b), the sheet material 200 configured as described above is folded along the boundary lines P and Q to form the core layer 110. Specifically, the sheet material 200 is valley-folded at the boundary line P between the flat area 210 and the bulging area 220, and mountain-folded at the boundary line Q between the top surface and side surface of the first bulging portion 221 to compress in the Y direction. Then, as shown in Fig. 5(b) and (c), the top surface and side surface of the first bulging portion 221 are folded over, and the end surface of the second bulging portion 222 and the flat area 210 are folded over, thereby forming one rectangular column-shaped partition 230 extending in the X direction for one bulging area 220. Such partitions 230 are continuously formed in the Y direction to form the hollow plate-shaped core layer 110.

[0025] When the sheet material 200 is compressed as described above, the upper surface and side surface of the first bulge portion 221 form the closed wall portion 111 of the core layer 110, and the end surface of the second bulge portion 222 and the flat area 210 form the closed wall portion 112 of the core layer 110. As shown in Fig. 5(c), the portion of the closed wall portion 111 where the upper surface and side surface of the first bulge portion 221 are folded over to form a two-layer structure becomes the overlapping portion 231. Also, the portion of the closed wall portion 112 where the end surface of the second bulge portion 222 and the flat area 210 are folded over to form a two-layer structure becomes the overlapping portion 231.

[0026] Moreover, a hexagonal columnar region formed by folding the second bulging portion 222 becomes the second cell S2, and a hexagonal columnar region formed between a pair of adjacent partitions 230 becomes the first cell S1. In this embodiment, the upper surface and side surface of the second bulging portion 222 form the side wall portion 113 of the second cell S2, and the side surface of the second bulging portion 222 and a flat portion located between the second bulging portions 222 in the bulging region 220 form the side wall portion 113 of the first cell S1. The contact portion between the upper surfaces of the second bulging portions 222 and the contact portion between the flat portions in the bulging region 220 form the side wall portion 113 having a two-layer structure. Note that, when carrying out such a folding process, it is preferable to heat-treat the sheet material 200 so as to soften it.

[0027] Next, the skin layer 120 is superimposed on one main surface of the core layer 110, and the skin layer 130 is superimposed on the other main surface of the core layer 110. The skin layers 120, 130 are preferably softened by heat treatment. By heat treating the skin layers 120, 130, the adhesive layer of thermoplastic resin coated on the skin layers 120, 130 is partially thermally melted. Therefore, the skin layers 120, 130 superimposed on the core layer 110 are positioned in a state of being temporarily bonded to the core layer 110. The adhesive layer solidifies due to a decrease in temperature of the core layer 110 and the skin layers 120, 130, and the skin layers 120, 130 are bonded to the core layer 110 to form the hollow plate material 100.

[0028] <First Hollow Plate 101, Second Hollow Plate 102, and Third Hollow Plate 103> As shown in Fig. 2, the first hollow plate 101, the second hollow plate 102 and the third hollow plate 103 are square-shaped when viewed from above in the plate thickness direction. In the same plan view, the lengths of the sides of the first hollow plate 101, the second hollow plate 102 and the third hollow plate 103 are equal. As shown in Fig. 3, the plate thickness of the first hollow plate 101 and the plate thickness of the third hollow plate 103 are equal. On the other hand, the plate thickness of the second hollow plate 102 is thinner than the plate thickness of the first hollow plate 101 and the plate thickness of the third hollow plate 103. In detail, the plate thickness of the core layer 110 of the first hollow plate 101 and the plate thickness of the core layer 110 of the third hollow plate 103 are equal. On the other hand, the thickness of the core layer 110 of the second hollow plate 102 is thinner than the thicknesses of the core layers 110 of the first hollow plate 101 and the third hollow plate 103 .

[0029] The first hollow plate 101, the second hollow plate 102, and the third hollow plate 103 are stacked. At this time, in the plate thickness direction, the skin layer 120 of the first hollow plate 101 and the skin layer 130 of the second hollow plate 102 face each other. Also, in the plate thickness direction, the skin layer 120 of the second hollow plate 102 and the skin layer 130 of the third hollow plate 103 face each other. In other words, the second hollow plate 102 is located between the first hollow plate 101 and the third hollow plate 103 in the plate thickness direction.

[0030] The size of the cells S constituting the core layer 110 of the first hollow plate material 101 and the third hollow plate material 103 is equal. On the other hand, the size of the cells S constituting the core layer 110 of the second hollow plate material 102 is smaller than the size of the cells S constituting the core layer 110 of the first hollow plate material 101 and the third hollow plate material 103. Here, the size of the cells S is the size of the cells S as viewed from the plate thickness direction. In other words, the size of the cells S is the size of the bottom and top surfaces of the cells S. In this embodiment, the size of the cells S can also be rephrased as the length of the diagonal of the cells S forming a regular hexagonal shape.

[0031] Therefore, the multiple cells S constituting the core layer 110 of the first hollow plate 101 and the multiple cells S constituting the core layer 110 of the second hollow plate 102 adjacent in the plate thickness direction are positioned with a shift. Similarly, the multiple cells S constituting the core layer 110 of the second hollow plate 102 and the multiple cells S constituting the core layer 110 of the third hollow plate 103 adjacent in the plate thickness direction are positioned with a shift in the plate thickness direction. Here, the position of the multiple cells S constituting the core layer 110 of two hollow plate materials 100 adjacent in the plate thickness direction being shifted in the plate thickness direction means that the positions of the side walls 113 dividing the multiple cells S are shifted. In addition, the position of the side wall 113 of one core layer 110 and the position of the side wall 113 of the other core layer 110 may partially coincide.

[0032] <First bonding layer 81, 82> As shown in FIG. 3, the first bonding layer 81 bonds the first hollow plate 101 and the second hollow plate 102. More specifically, the first bonding layer 81 bonds the skin layer 120 of the first hollow plate 101 and the skin layer 130 of the second hollow plate 102. Similarly, the first bonding layer 82 bonds the second hollow plate 102 and the third hollow plate 103. More specifically, the first bonding layer 82 bonds the skin layer 120 of the second hollow plate 102 and the skin layer 130 of the third hollow plate 103. The first bonding layers 81 and 82 are layers formed by solidifying an adhesive. In other embodiments, the first bonding layers 81 and 82 may be layers formed by welding the first hollow plate 101 and the second hollow plate 102, or by welding the second hollow plate 102 and the third hollow plate 103.

[0033] <First cover 50 and second cover 60> As shown in Figures 2 and 3, the first cover 50 and the second cover 60 are box-shaped. The first cover 50 and the second cover 60 are made of metal. The first cover 50 and the second cover 60 may be made of aluminum or iron. As an example, the first cover 50 and the second cover 60 may be made of plated steel sheet. The first cover 50 and the second cover 60 correspond to "metal covers".

[0034] The first cover 50 has a plate-shaped bottom wall 51 and four side walls 52. The bottom wall 51 has a square shape in a plan view in the plate thickness direction. The four side walls 52 have a rectangular shape in a plan view in a direction perpendicular to the plate thickness direction. The plate thickness of the bottom wall 51 and the plate thickness of the four side walls 52 are equal. In the plate thickness direction of the bottom wall 51, the length of the four side walls 52 is slightly thinner than the plate thickness of the laminated structure 40. The four side walls 52 extend from the four edges of the bottom wall 51 in the plate thickness direction of the bottom wall 51. The first cover 50 accommodates the laminated structure 40 from below.

[0035] The second cover 60 has a plate-shaped upper wall 61 and four side walls 62. The upper wall 61 has a square shape in a plan view in the plate thickness direction. The four side walls 62 have a rectangular shape in a plan view in a direction perpendicular to the plate thickness direction. The plate thickness of the upper wall 61 and the plate thickness of the four side walls 62 are equal. In the plate thickness direction of the upper wall 61, the length of the four side walls 62 is slightly thinner than the plate thickness of the laminated structure 40. The four side walls 62 extend from the four edges of the upper wall 61 in the plate thickness direction of the upper wall 61. In the second cover 60, the interval between two opposing side walls 62 is slightly wider than the interval between two opposing side walls 52 in the first cover 50. The second cover 60 covers the laminated structure 40 and the first cover 50 from above. At this time, the inner surfaces of the four side walls 62 of the second cover 60 face the outer surfaces of the four side walls 62 of the first cover 50, respectively.

[0036] The plate thickness of the first cover 50 and the plate thickness of the second cover 60 are thinner than the plate thickness of any of the hollow plate materials 100. Here, the plate thickness of the first cover 50 refers to, for example, the plate thickness of the bottom wall 51 of the first cover 50 and the plate thickness of the side wall 52 of the first cover 50. The same applies to the plate thickness of the second cover 60.

[0037] Also, as shown in FIG. 3, the distance between the side surface along the thickness direction of the laminated structure 40 and the side wall 52 of the first cover 50 is wider than the distance between the side wall 52 of the first cover 50 and the side wall 62 of the second cover 60.

[0038] <Second bonding layer 71, 72> As shown in Fig. 3, the second bonding layer 71 bonds the laminated structure 40 and the first cover 50. More specifically, the second bonding layer 71 bonds the skin layer 130 of the first hollow plate material 101 and the bottom wall 51 of the first cover 50. Similarly, the second bonding layer 72 bonds the laminated structure 40 and the second cover 60. More specifically, the second bonding layer 72 bonds the skin layer 120 of the third hollow plate material 103 and the upper wall 61 of the second cover 60. The second bonding layers 71 and 72 are layers formed by solidifying an adhesive.

[0039] The four side surfaces of the laminated structure 40 and the four side walls 52 of the first cover 50 may or may not be joined together. Similarly, the four side walls 52 of the first cover 50 and the four side walls 62 of the second cover 60 may or may not be joined together.

[0040] <Relationship between the support leg 20 and the floor panel 30> As shown in Fig. 1, the multiple support legs 20 are arranged in a grid pattern on the floor FL of the building. The multiple floor panels 30 are placed on the multiple support legs 20. At this time, corners of one floor panel 30 are placed on four support legs 20. It is preferable that the floor panel 30 is fixed so as not to move relative to the support legs 20. In this way, a space for placing electric wires, communication lines, etc. is formed between the multiple floor panels 30 and the floor FL of the building. In other words, a double floor structure 10 is constructed.

[0041] <Method of manufacturing the floor panel 30> An example of a manufacturing method for the floor panel 30 will be described. The manufacturing method for the floor panel 30 may include a first joining step and a second joining step. The first joining step is a step of manufacturing the laminated structure 40 by joining the first hollow plate material 101, the second hollow plate material 102, and the third hollow plate material 103. The second joining step is a step subsequent to the first joining step, and is a step of joining the first cover 50 and the second cover 60 to the laminated structure 40. In such a manufacturing method for the floor panel 30, the first joining step and the second joining step can be performed separately, and therefore it is not necessary to perform the first joining step and the second joining step consecutively.

[0042] In the manufacturing method of the floor panel 30, it is preferable to apply a larger amount of adhesive between the laminated structure 40 and the bottom wall 51 of the first cover 50 and between the laminated structure 40 and the top wall 61 of the second cover 60 in the second joining step. This allows the side surface of the laminated structure 40 and the side wall 52 of the first cover 50 to be bonded by the adhesive overflowing from between the laminated structure 40 and the bottom wall 51 of the first cover 50. In addition, the side surface of the laminated structure 40 and the side wall 52 of the first cover 50 can be bonded by the adhesive overflowing from between the laminated structure 40 and the top wall 61 of the second cover 60.

[0043] Another manufacturing method of the floor panel 30 may include a lamination process and a pressure bonding process. The lamination process is a process of sequentially laminating the first cover 50, the first hollow plate 101, the second hollow plate 102, the third hollow plate 103, and the second cover 60 while applying adhesive between them. The pressure bonding process is a process of bonding the laminated first cover 50, the first hollow plate 101, the second hollow plate 102, the third hollow plate 103, and the second cover 60 by compressing them in the plate thickness direction. In such a manufacturing method of the floor panel 30, it is preferable to apply a larger amount of adhesive in the lamination process. In this way, the adhesive overflowing from between the three hollow plate materials 100 can bond the side surfaces of the three hollow plate materials 100 to the side wall 52 of the first cover 50.

[0044] The thickness of the first bonding layers 81, 82 formed through the above-described manufacturing method is preferably thinner than the plate thickness of the first cover 50 and the plate thickness of the second cover 60. Similarly, the thickness of the second bonding layers 71, 72 is preferably thinner than the plate thickness of the first cover 50 and the plate thickness of the second cover 60.

[0045] <Actions and Effects of the Present Embodiment> (1) Equipment, furniture, etc. are placed on the multiple floor panels 30 constituting the double floor structure 10. Therefore, loads such as shear force act downward on the parts of the multiple floor panels 30 on which the equipment, furniture, etc. are placed. In addition, a reaction force of the above load acts upward on the parts of the multiple floor panels 30 supported by the multiple support legs 20. In this regard, the floor panel 30 of this embodiment is formed by joining three hollow plate materials 100 in the plate thickness direction. Therefore, the floor panel 30 can have higher rigidity against loads such as shear force compared to a case where the floor panel 30 is formed only from a single hollow plate material 100. In addition, the floor panel 30 is easy to manufacture because it is formed by joining three hollow plate materials 100 manufactured separately.

[0046] (2) In the first hollow plate material 101 and the second hollow plate material 102, which are stacked in the plate thickness direction, the positions of the multiple cells S that make up the core layer 110 are shifted in the plate thickness direction. Similarly, in the second hollow plate material 102 and the third hollow plate material 103, which are stacked in the plate thickness direction, the positions of the multiple cells S that make up the core layer 110 are shifted in the plate thickness direction. Therefore, the floor panel 30 can suppress stress concentration in specific areas when a load such as a shear force is applied.

[0047] (3) The first hollow plate 101 and the second hollow plate 102 stacked in the plate thickness direction have different sizes of the cells S constituting the core layer 110. Therefore, in the first hollow plate 101 and the second hollow plate 102, the positions of the cells S constituting the core layer 110 are inevitably shifted in the plate thickness direction. Similarly, the second hollow plate 102 and the third hollow plate 103 stacked in the plate thickness direction have different sizes of the cells S constituting the core layer 110. Therefore, in the second hollow plate 102 and the third hollow plate 103, the positions of the cells S constituting the core layer 110 are inevitably shifted in the plate thickness direction. As a result, when stacking three hollow plate materials 100, it is no longer necessary to intentionally shift the cells S constituting the core layer 110 of two adjacent hollow plate materials 100.

[0048] (4) The floor panel 30 includes a first cover 50 and a second cover 60 that cover the laminated structure 40. This allows the floor panel 30 to have even greater rigidity. The first cover 50 and the second cover 60 cover not only both sides of the laminated structure 40 in the thickness direction, but also the four side surfaces of the laminated structure 40 along the thickness direction. This allows the floor panel 30 to have even greater rigidity against loads acting on both sides in the thickness direction, as well as against loads acting on the side surfaces along the thickness direction.

[0049] <Example of change> This embodiment can be modified as follows: This embodiment and the following modifications can be combined with each other to the extent that there is no technical contradiction.

[0050] As shown in FIG. 6, the floor panel 30 may be a floor panel 30A including a laminated structure 40A, a first cover 50, and a second cover 60. In the floor panel 30A of the modified example, the laminated structure 40A includes a first hollow board 104 (100) and a second hollow board 105 (100), a base material 90, a first bonding layer 81A, 82A, and a second bonding layer 71, 72. As in the above embodiment, the first hollow board 104 and the second hollow board 105 include a core layer 110 in which a plurality of columnar cells S are arranged in a direction intersecting the board thickness direction, and two skin layers 120, 130 that are respectively bonded to both sides of the core layer 110 in the board thickness direction. The base material 90 is made of foamed resin or wood. The base material 90 is laminated between the first hollow board 104 and the second hollow board 105 in the board thickness direction. It is preferable that the base material 90 be changed according to the plate thickness required for the floor panel 30A. In the plate thickness direction, the first bonding layer 81A bonds the skin layer 120 of the first hollow plate material 104 to the lower surface of the base material 90, and the first bonding layer 82A bonds the skin layer 130 of the first hollow plate material 104 to the upper surface of the base material 90.

[0051] The floor panel 30A shown in Fig. 6 is constructed by joining two hollow boards 100 and a base material 90 in the board thickness direction. This allows the floor panel 30A to have higher rigidity against loads such as shear force compared to a floor panel constructed with only a single hollow board material 100. Also, by selecting an inexpensive base material 90, the floor panel 30A can be constructed at a lower cost compared to a floor panel constructed with three layers of hollow board materials 100.

[0052] The number of layers of the hollow plate materials 100 in the layered structure 40 may be "2." Also, the number of layers of the hollow plate materials 100 in the layered structure 40 may be "4" or more. When the number of layers in the laminated structure 40 is "3" or less, it is preferable that the plate thickness of the first cover 50 and the second cover 60 is equal to or greater than the plate thickness of the sheet material 200. On the other hand, when the number of layers in the laminated structure 40 is "4" or more, it is preferable that the plate thickness of the first cover 50 and the second cover 60 is less than the plate thickness of the sheet material 200. This makes it easier to balance the weight and rigidity of the floor panel 30. The plate thickness of the sheet material 200 refers to the plate thickness of the blocking walls 111, 112 and the plate thickness of the side wall 113 in the hollow plate material 100.

[0053] The sheet material 200 is preferably thicker than the first cover 50 and the second cover 60. In addition, the first cover 50 and the second cover 60 are preferably thicker than the first bonding layers 81, 82 and the second bonding layers 71, 72.

[0054] The cells S constituting the core layers 110 of the three hollow plate materials 100 in the laminated structure 40 may be of equal size. In this case, it is preferable that the cells S constituting the core layers 110 of the hollow plate materials 100 adjacent to each other in the plate thickness direction are shifted from each other.

[0055] The sizes of the cells S constituting the core layers 110 of the three hollow plate materials 100 in the laminated structure 40 may all be different. In the laminated structure 40, the cells S constituting the core layer 110 of the first hollow plate material 101 and the third hollow plate material 103 may be smaller than the cells S constituting the core layer 110 of the second hollow plate material 102. In this case, it is preferable that the plate thickness of the first hollow plate material 101 and the plate thickness of the third hollow plate material 103 are thinner than the plate thickness of the second hollow plate material 102.

[0056] A hollow plate material 100 in which the cells S constituting the core layer 110 have a small diameter has a higher compressive strength in the plate thickness direction than a hollow plate material 100 in which the cells S constituting the core layer 110 have a large diameter. For this reason, when the diameters of the cells S constituting the core layers 110 of the first hollow plate material 101 and the third hollow plate material 103 are made smaller than the diameter of the cells S constituting the core layer 110 of the second hollow plate material 102, the laminated structure 40 can be prevented from generating indentations due to concentrated loads acting on both sides.

[0057] The cells S constituting the core layer 110 of the hollow plate material 100 do not have to be in the shape of a hexagonal column. For example, the cells S constituting the core layer 110 may be in the shape of a polygonal column, such as a quadrangular column or an octagonal column, or may be in the shape of a cylinder.

[0058] The thicknesses of the three hollow plate materials 100 in the laminated structure 40 may all be the same or may all be different. The hollow plate material 100 is not limited to being formed by folding a single sheet material 200 to form the core layer 110, but multiple sheets may be used to form the core layer 110. For example, the core layer 110 may be formed by bending a strip-shaped sheet at predetermined intervals and arranging multiple bent strip-shaped sheets side by side.

[0059] In the above embodiment, one sheet material 200 is folded and molded to form the core layer 110 as a honeycomb structure in which the hexagonal cells S are partitioned inside the core layer 110, but the molding method is not limited to this. For example, as described in Japanese Patent No. 4368399, the core layer 110 as a honeycomb structure may be formed by sequentially folding a three-dimensional structure in which multiple rows of convex portions each having a trapezoidal cross section are provided.

[0060] The hollow board 100 may be a plastic cardboard having a harmonica-shaped cross section. In this case, the cells constituting the core layer of the hollow board are arranged in a first direction perpendicular to the board thickness direction, but are not arranged in a second direction perpendicular to both the board thickness direction and the first direction.

[0061] In a plan view in the plate thickness direction, the shape of the floor panel 30 does not have to be a square. The shape of the floor panel 30 may be a triangular shape or a hexagonal prism. The first cover 50 needs to have at least a bottom wall 51. Similarly, the second cover 60 needs to have at least a top wall 61. In other words, the first cover 50 and the second cover 60 need to cover the surfaces of the laminated structure 40 on which a load acts.

[0062] The side wall 52 of the first cover 50 and the side wall 62 of the second cover 60 may be fixed together using a fastening member such as a rivet. The first cover 50 and the second cover 60 may be integrally formed. It is preferable that the integrally formed cover has an opening for accommodating the laminated structure 40 in a side wall along the plate thickness direction.

[0063] The first cover 50 and the second cover 60 may be omitted. In this case, it is preferable to provide a reinforcing structure on both sides of the laminated structure 40 in the plate thickness direction. The flexural modulus of elasticity of the first cover 50 and the second cover 60 is preferably higher than the flexural modulus of elasticity of the hollow plate material 100 .

[0064] In the above-mentioned method for manufacturing the floor panel 30, the first and second joining steps can be performed consecutively without an interval. In this case, it is preferable to increase the amount of adhesive used to join the multiple hollow plate materials 100 in the first joining step. According to this, in the second joining step, the adhesive overflowing from between the multiple hollow plate materials 100 is more likely to enter the gap between the multiple hollow plate materials 100 and the side wall 52 of the first cover 50. As a result, the joining strength between the multiple hollow plate materials 100 and the side wall 52 of the first cover 50 is increased. In addition, in the method for manufacturing the floor panel 30 according to this modified example, it is preferable that the second joining step presses the multiple hollow plate materials 100 between the first cover 50 and the second cover 60.

[0065] In the hollow plate material 100, the synthetic resin constituting the core layer 110 and the skin layers 120 and 130 may contain an inorganic material. Examples of the inorganic material include talc, mica, glass fiber, magnesium hydroxide, and aluminum hydroxide.

[0066] <Additional Notes> The technical ideas that can be understood from the above-described embodiment and modified examples will be described. [Mode 1] A floor panel in the form of a plate, comprising a core layer in which a number of columnar cells are arranged side by side in a direction intersecting the plate thickness direction, and two skin layers joined to both sides of the core layer in the plate thickness direction, the floor panel comprising a number of hollow plate materials stacked in the plate thickness direction, and a joining layer joining two adjacent hollow plate materials in the plate thickness direction.

[0067] [Aspect 2] A floor panel as described in Aspect 1, wherein in two hollow boards adjacent in the thickness direction, the plurality of cells constituting the core layer of one hollow board and the plurality of cells constituting the core layer of the other hollow board are positioned offset in the thickness direction.

[0068] [Aspect 3] A floor panel as described in Aspect 2, wherein in two hollow boards adjacent in the thickness direction, the plurality of cells constituting the core layer of one hollow board and the plurality of cells constituting the core layer of the other hollow board are different sizes.

[0069] [Aspect 4] A floor panel described in any one of Aspects 1 to 3, comprising a laminated structure comprising a structure including the multiple hollow plate materials and the joining layer, and a first joining layer, the floor panel comprising a metal cover made of metal covering both sides of the laminated structure in the plate thickness direction, and a second joining layer joining both sides of the laminated structure in the plate thickness direction to the metal cover.

[0070] [Embodiment 5] A board-shaped floor panel comprising: a first hollow board and a second hollow board having a core layer in which a number of columnar cells are juxtaposed in a direction intersecting the board thickness direction; and two skin layers joined to both sides of the core layer in the board thickness direction; a foamed resin or wooden base material laminated between the first hollow board and the second hollow board in the board thickness direction; a first bonding layer bonding the first hollow board to the base material; and a second bonding layer bonding the second hollow board to the base material. [Explanation of symbols]

[0071] FL...floor, S...cell, 10...double floor structure, 20...support leg, 30, 30A...floor panel, 40, 40A...laminated structure, 50...first cover (metal cover), 60...second cover (metal cover), 71, 72...second bonding layer, 81, 81A, 82, 82A...first bonding layer, 90...base material, 100 (101 to 105)...hollow plate material, 110...core layer, 120...skin layer, 130...skin layer.

Claims

1. A plate-shaped floor panel, A plurality of hollow plate materials each having a core layer in which a plurality of columnar cells are arranged in a direction intersecting a plate thickness direction, and two skin layers bonded to both sides of the core layer in the plate thickness direction, the plurality of hollow plate materials being stacked in the plate thickness direction; A joining layer that joins two of the hollow plate materials adjacent to each other in the plate thickness direction. Floor panel.

2. In two hollow plate materials adjacent to each other in the plate thickness direction, the plurality of cells constituting the core layer of one hollow plate material and the plurality of cells constituting the core layer of the other hollow plate material are positioned offset from each other in the plate thickness direction.

2. The floor panel of claim 1.

3. In two hollow plate materials adjacent to each other in the plate thickness direction, the plurality of cells constituting the core layer of one hollow plate material and the plurality of cells constituting the core layer of the other hollow plate material have different sizes.

3. A floor panel according to claim 2.

4. When a structure including the plurality of hollow plate materials and the bonding layer is a laminated structure, and the bonding layer is a first bonding layer, a metal cover made of metal that covers both surfaces of the laminated structure in the plate thickness direction; a second bonding layer that bonds both surfaces of the laminated structure in the plate thickness direction to the metal cover; A floor panel according to any one of claims 1 to 3.

5. A plate-shaped floor panel, A first hollow plate and a second hollow plate each having a core layer in which a plurality of columnar cells are arranged in a direction intersecting the plate thickness direction, and two skin layers respectively joined to both sides of the core layer in the plate thickness direction; A foamed resin or wooden base material laminated between the first hollow board material and the second hollow board material in the board thickness direction; a first bonding layer that bonds the first hollow plate material and the base material; A second bonding layer that bonds the second hollow plate material and the base material. Floor panel.

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