阅读说明：本技术 板材 (Sheet material ) 是由 小原和也 大矢隆义 于 2018-06-27 设计创作，主要内容包括：本发明提供中空板材,具备：树脂制芯层,具有第1面、第2面以及划定多个小室的多个隔壁；第1表皮层,层叠在芯层的第1面；以及第2表皮层,层叠在芯层的第2面。板材具有：侧缘,包含芯层在厚度方向上被压缩的压缩部；以及端面,在侧缘中,第1表皮层和第2表皮层中的至少一个表皮层向另一个表皮层折弯而形成。压缩部在端面中设置在第1表皮层与第2表皮层之间。端面的倾斜角度为70度以上。(The present invention provides a hollow plate material, comprising: a resin core layer having a 1 st surface, a 2 nd surface, and a plurality of partition walls defining a plurality of cells; a 1 st skin layer laminated on the 1 st surface of the core layer; and a 2 nd skin layer laminated on the 2 nd surface of the core layer. The sheet material has: a side edge including a compression portion in which the core layer is compressed in a thickness direction; and an end face formed by bending at least one of the 1 st skin layer and the 2 nd skin layer toward the other skin layer at the side edge. The compression section is disposed between the 1 st and 2 nd skin layers in the end face. The inclination angle of the end face is 70 degrees or more.)

1. A plate material is a hollow plate material, and is provided with:

a resin core layer having a 1 st surface, a 2 nd surface on the opposite side of the 1 st surface, and a plurality of partition walls extending between the 1 st surface and the 2 nd surface to define a plurality of cells;

a 1 st skin layer laminated on the 1 st surface of the core layer;

a 2 nd skin layer laminated on the 2 nd surface of the core layer,

the sheet material has: a side edge including a compressed portion in which the core layer is compressed in a thickness direction; and end faces formed by bending at least one of the 1 st skin layer and the 2 nd skin layer toward the other skin layer at the side edges,

the compressed portion is provided between the 1 st skin layer and the 2 nd skin layer at the end face,

the inclination angle of the end face is more than 70 degrees.

2. The sheet of material as defined in claim 1,

a plurality of said cells arranged along said side edges forming a cell array,

the core layer includes a first row of cell rows, a second row of cell rows, and a third row of cell rows arranged in this order from the side edge toward the inside in a direction intersecting the side edge,

the cells of the first column of cell rows and the second column of cell rows are compressed,

the cells of the third column of cells are not compressed.

3. A panel according to claim 1 or 2,

a steel plate is disposed between at least one of the 1 st surface and the 2 nd surface of the core layer and the skin layer facing the at least one surface.

4. A panel according to claim 3,

the at least one skin layer has a flat portion and a curved portion having a circular arc-shaped cross section between the flat portion and the end face,

the steel plate extends from a position in contact with the bent portion along the flat portion of the skin layer.

5. A panel according to any one of claims 1 to 4,

the 1 st skin layer or the 2 nd skin layer is composed of a nonwoven fabric.

6. A panel according to any one of claims 1 to 5,

the sheet material has at least one corner formed as the intersection of two of the side edges,

the corner portion has a flat portion whose thickness is thinner than that of the side edge, or the length of the compressed portion is longer than that of the side edge in a direction intersecting the side edge.

7. A plate material having a polygonal plate shape, comprising: a core layer composed of a foam or a hollow body including a plurality of cells; and two skin layers laminated on both surfaces of the core layer,

the sheet material has: a plurality of side edges including a compressed portion in which the core layer is compressed in a thickness direction; an end face formed by bending one of the two skin layers toward the other at each of the side edges; and a corner portion formed by intersecting the two side edges,

the compressed portion is disposed between the two skin layers at the end face,

the corner portion has a flat portion at which the compressed portion is formed wider than the compressed portion at a portion of the side edge other than the corner portion.

8. A plate material having a polygonal plate shape, comprising: a core layer composed of a foam or a hollow body including a plurality of cells; and two skin layers laminated on both surfaces of the core layer,

the sheet material has: a plurality of side edges including a compressed portion in which the core layer is compressed in a thickness direction; an end face formed by bending one of the two skin layers toward the other of the two skin layers at each of the side edges; and a corner portion formed by intersecting the two side edges,

the corner portion has a flat portion whose thickness is thinner than that of a portion of the side edge other than the corner portion,

the flat portion is formed by the core layer and at least one of the two skin layers being compressed in the thickness direction.

9. A panel according to any one of claims 6 to 8,

the corner portion further has a slope connected to an inner end of the flat portion,

the inclined surface extends obliquely with respect to both surfaces of the plate material.

10. The sheet of material as defined in claim 9,

the area of the slope is larger than that of the flat portion.

11. A panel according to any one of claims 6 to 10,

the edge of the flat portion is formed in a curved shape.

Technical Field

The present invention relates to sheet materials.

Background

A hollow plate material made of synthetic resin is lightweight and excellent in handling properties. Therefore, the hollow board material is sometimes used as a deck board. The shelf board is used in, for example, a display shelf for displaying books, small articles, and the like, or a storage box for storing books, shoes, and the like. Patent document 1 describes that a shelf board made of a hollow plate material is assembled to a box-shaped frame body and used as a display shelf or a storage shelf. As shown in fig. 16(a), the shelf disclosed in patent document 1 includes two square frame-shaped frames 101, and each frame 101 has two inner walls 102 disposed to face each other. The two inner side walls have groove-shaped support portions 300 at positions opposite to each other. When the deck board 200 is slid to the two support portions 300 arranged oppositely to trap the side edges 201 of the deck board 200 into the support portions 300, the side edges 201 of the deck board 200 are supported by the support portions 300. Thereby, the deck board 200 is assembled to a predetermined position of the frame 101.

Patent document 2 describes that a pallet board made of a plate material is assembled to a box-shaped frame body and used as a storage box for storing shoes and the like. The synthetic resin-made shelf board disclosed in patent document 2 is formed in a quadrangular plate shape including an upper plate portion, a lower plate portion, a front plate portion, and a rear plate portion. The shelf board is fitted to a predetermined position in the storage box by engaging the mortise receiving recess provided in the lower plate portion with the mortise protrusion provided to protrude on the inner surface of the storage box. The mortise convex part is formed in multiple stages, and the position of the shelf board in the storage box can be appropriately changed by changing the position of the mortise convex part for locking the lower plate part.

Disclosure of Invention

Problems to be solved by the invention

As shown in fig. 16(b), the support portion 300 of the frame 101 is formed as a groove having a square cross section, and the cross section of the side edge 201 of the shelf board 200 supported by the support portion 300 has an arc shape. Therefore, a gap is formed between the side edge 201 of the deck board 200 and the support portion 300, and foreign matter, such as dust or dirt, is likely to accumulate in the gap. Further, since the side edge 201 has a circular arc shape in cross section, when the depth of the groove serving as the support portion 300 is shallow, the end portion of the side edge 201 is hardly held in the groove, and the shelf plate 200 cannot be stably supported.

In addition, when the position of the deck plate is changed, the deck plate may be erroneously dropped. Since conventional deck boards have a quadrangular plate shape, if corners of the deck boards hit the floor when dropped, impact may concentrate on the corners and deform the corners.

Means for solving the problems

The disclosed plate material is a hollow plate material, and is provided with: a resin core layer having a 1 st surface, a 2 nd surface on the opposite side of the 1 st surface, and a plurality of partition walls extending between the 1 st surface and the 2 nd surface to define a plurality of cells; a 1 st skin layer laminated on the 1 st surface of the core layer; and a 2 nd skin layer laminated on the 2 nd surface of the core layer. The sheet material has: a side edge including a compressed portion in which the core layer is compressed in a thickness direction; and an end face formed by bending at least one of the 1 st skin layer and the 2 nd skin layer toward the other skin layer at the side edge. The compressed portion is provided between the 1 st skin layer and the 2 nd skin layer at the end face. The inclination angle of the end face is more than 70 degrees.

The disclosed plate material is a plate material in the shape of a polygonal plate, and is provided with: a core layer composed of a foam or a hollow body including a plurality of cells; and two skin layers laminated on both surfaces of the core layer. The sheet material has: a plurality of side edges including a compressed portion in which the core layer is compressed in a thickness direction; an end face formed by bending one of the two skin layers toward the other at each of the side edges; and a corner portion formed by intersecting the two side edges. The compressed portion is disposed between the two skin layers at the end face. The corner portion has a flat portion at which the compressed portion is formed wider than the compressed portion at a portion of the side edge other than the corner portion.

The disclosed plate material is a plate material in the shape of a polygonal plate, and is provided with: a core layer composed of a foam or a hollow body including a plurality of cells; and two skin layers laminated on both surfaces of the core layer. The sheet material has: a plurality of side edges including a compressed portion in which the core layer is compressed in a thickness direction; an end face formed by bending one of the two skin layers toward the other of the two skin layers at each of the side edges; and a corner portion formed by intersecting the two side edges. The corner portion has a flat portion whose thickness is thinner than that of a portion of the side edge other than the corner portion. The flat portion is formed by the core layer and at least one of the two skin layers being compressed in the thickness direction.

Drawings

Fig. 1(a) is a perspective view of a storage box in which the panel according to embodiment 1 is applied as a deck board, and fig. 1(b) is a sectional view of the deck board of fig. 1(a) taken along line α - α.

Fig. 2(a) is a perspective view showing a cross-section of the deck board of fig. 1(a) along line α - α, and fig. 2(b) is a cross-sectional view of the deck board of fig. 1(a) along line β - β.

Fig. 3(a) is a perspective view of a core layer provided in the deck board of embodiment 1; FIG. 3(b) is a cross-sectional view taken along line γ - γ of FIG. 3 (a); fig. 3(c) is a cross-sectional view taken along the δ - δ line of fig. 3 (a).

FIG. 4(a) is a perspective view of a sheet constituting the core layer of FIG. 3 (a); fig. 4(b) is a perspective view illustrating a folding midway state of the sheet of fig. 4 (a); fig. 4(c) is a perspective view illustrating a state in which the sheet of fig. 4(b) is folded.

Fig. 5(a) to 5(f) are views for explaining a method of manufacturing the deck board of fig. 1 (b).

Fig. 6(a) and 6(b) are sectional views showing a part of a modification of the deck board of fig. 1 (b).

Fig. 7 is a perspective view of a storage box in which the plate material of embodiment 2 is applied to a deck board.

Fig. 8 is an overall perspective view of the deck board of fig. 7.

Fig. 9 is a partial perspective view of the deck board of fig. 7.

Fig. 10 is a view illustrating a corner portion of the deck board of fig. 7.

Fig. 11(a) is a sectional view taken along the line γ - γ in fig. 10; fig. 11(b) is a cross-sectional view taken along the σ - σ line of fig. 5.

Fig. 12(a), 12(b), 12(c), and 12(d) are views for explaining a method of manufacturing the deck board of fig. 7.

Fig. 13 is a modification of the corner of the shelf board of fig. 7.

Fig. 14 is a modification of the corner of the shelf board of fig. 7.

Fig. 15(a) and 15(b) are modifications of the side edges of the shelf board of fig. 7.

Fig. 16(a) is a perspective view of a display rack to which a conventional shelf board is applied; fig. 16(b) is a cross-sectional view showing a state in which the conventional deck board is supported by the support portion.

Detailed Description

(embodiment 1)

The plate material according to embodiment 1 is used as a shelf board of a storage box for storing books, shoes, and the like, for example.

As shown in fig. 1(a), the storage box includes: a storage box 1 having a bottom wall 1a, an upper wall 1b, two side walls 1c, and an inner wall 1 d; and rectangular plate-like deck boards 2. The two side walls 1c, 1c are arranged opposite to each other. The two side walls 1c, 1c have a plurality of support portions 11, and the plurality of support portions 11 protrude inward from respective inner surfaces opposed to each other. The plurality of support portions 11 extend in the width direction of the side wall 1c and are arranged in the vertical direction.

As shown in fig. 1(a), the length of the long side of the deck plate 2 is slightly shorter than the length between the inner surfaces of the two side walls 1c, 1c that face each other. The length of the short side of the deck boards 2 is slightly shorter than the width of the side walls 1 c. The shelf plate 2 having such a shape is mounted at a predetermined position of the storage box 1 by placing both end portions in the longitudinal direction of the shelf plate 2 on the two support portions 11 of the storage box 1 which are disposed to face each other. Thereby, the shelf plate 2 defines the internal space of the storage case 1 into a plurality of spaces.

As shown in fig. 1(b), the deck board 2 has: a lower surface 2c which is smooth throughout the entirety; two upper surfaces 2a extending over the entire length in the longitudinal direction; and a concave surface 2 b. The two upper surfaces 2a are both end portions in the short side direction of the upper side surface of the deck plate 2. The concave surface 2b is recessed downward with respect to the both upper surfaces 2a, and extends over the entire length of the shelf plate 2 in the longitudinal direction between the both upper surfaces 2 a. The upper surface 2a is a smooth surface. In addition, the concave surface 2b has two slopes respectively connected to the two upper surfaces 2a, and a central portion between the two slopes is a smooth surface. The deck plate 2 also has four end faces 2d, the four end faces 2d being steep slopes which are inclined toward the upper side in such a manner as to extend to the outer side of the deck plate 2.

As shown in fig. 1(b) and 2(a), the deck board 2 includes: a rectangular plate-shaped thermoplastic resin core layer 20; rectangular thin plate-shaped steel plates 43, 44; and a skin 1 layer (skin layer)50 and a skin 2 layer 60 made of a thermoplastic resin. The core layer 20 has: 1 st face (upper face); a 2 nd surface (lower surface) on the opposite side of the 1 st surface; and a plurality of cells (cells) S arranged between the 1 st plane and the 2 nd plane. The steel plates 43, 44 are joined to a part of the upper surface and a part of the lower surface of the core layer 20, respectively. The 1 st skin layer 50 is laminated in contact with the upper surface of the steel sheet 43, and covers the entire 1 st surface of the core layer 20. The 2 nd skin layer 60 is laminated in contact with the lower surface of the steel sheet 44, and covers the entire 2 nd surface of the core layer 20. As shown in fig. 1(a) and 1(b), the steel plates 43 and 44 are disposed at substantially the center portion in the short side direction of the deck plate 2, and extend over the entire length in the long side direction of the deck plate 2 so as to reach both end portions in the long side direction of the deck plate 2.

As shown in fig. 2(a), the core layer 20 is not compressed at the portion corresponding to the upper surface 2a of the deck board 2. On the other hand, the core layer 20 is slightly thinner in the thickness direction in the portion corresponding to the smooth surface of the concave surface 2b than in the portion corresponding to the upper surface 2 a. Specifically, the cells S included in the core layer 20 at the portion corresponding to the concave surface 2b are configured such that the partition walls 23 described later are bent or inclined, or a part of the thermoplastic resin constituting the core layer 20 is melted and then solidified. All the side edges (four sides in the present embodiment) of the deck board 2 include compressed portions 20a in which the core layer 20 is compressed in the thickness direction. Here, the "compression portion 20 a" refers to the following portion: in the molding step described later, the thermoplastic resin constituting the core layer 20 is entirely melted and integrated by press molding, and the cells S forming the core layer 20 are deformed to such an extent that the shape of the partition walls 23 cannot be recognized.

As shown in fig. 2(a) and 2(b), the 2 nd skin layer 60 is folded toward the compressed portion 20a of the core layer 20 at all the side edges of the shelf board 2. In addition, the 1 st skin layer 50 extends horizontally without being bent at all the side edges of the deck board 2. The end edge 51 of the 1 st skin layer 50 and the end edge 61 of the 2 nd skin layer 60 abut each other with the compressed portion 20a of the core layer 20 therebetween.

As shown in fig. 2(b), the 2 nd skin layer 60 has: a flat portion forming the lower surface of the deck board 2; and a curved portion 62 having a circular arc-shaped cross section and bent from the flat portion. The curvature radius of the curved portion 62 is about 1mm to 5 mm. The portion of the 2 nd skin layer 60 extending from the bent portion 62 to the end edge 61 is formed to cover the end surface 63 of the core layer 20 from the side. The inclination angle θ of the end face 63 with respect to the lower surface of the 2 nd skin layer 60 may be 70 degrees or more. The inclination angle θ is more preferably 80 degrees or more, and still more preferably 85 degrees or more. As the inclination angle approaches 90 degrees, foreign matter, such as dust or dirt, is less likely to accumulate between the shelf plate 2 and the support portion 11, and the shelf plate 2 can be stably supported by the support portion 11. Thus, the tilt angle θ may be 70 ° ≦ θ <90 °.

In the deck board 2 according to embodiment 1, only the 2 nd skin layer 60 is folded over the entire length of the side edges, and the end face 63 of the 2 nd skin layer 60, the compressed portion 20a of the core layer 20, and the end edge 51 of the 1 st skin layer 50 constitute the end face 2d of the deck board 2. Therefore, the inclination angle of the end surface 2d of the deck board 2 in embodiment 1 is the same as the inclination angle of the end surface 63 of the skin layer 60. The end surface 63 is preferably a flat surface, but may be a curved surface. When the end surface 63 is a curved surface, the inclination angle of the end surface 2d indicates the inclination angle of a virtual plane connecting one end of the curved portion 62 close to the end edge 61 and the end edge 61.

As shown in fig. 3(a), the core layer 20 is formed by folding a single sheet of thermoplastic resin molded in a predetermined shape. The core 20 has a 1 st outer wall 21, a 2 nd outer wall 22, and a plurality of partition walls 23 extending between the 1 st outer wall 21 and the 2 nd outer wall 22. Six partition walls, the 1 st outer wall 21 and the 2 nd outer wall 22 define a hexagonal columnar cell S. As described below, the 1 st outer wall 21 and the 2 nd outer wall 22 of the core layer have a mixed configuration of a single-layer configuration and a double-layer configuration, but in fig. 1(b), 2, and 3(a), the 1 st outer wall 21 and the 2 nd outer wall 22 of the core layer 20 are illustrated as a single-layer configuration.

As shown in fig. 3(b) and 3(c), the plurality of cells S defined and formed inside the core layer 20 include the 1 st cell S1 and the 2 nd cell S2 having different structures from each other. As shown in fig. 3(b), in the 1 st cell S1, the 1 st outer wall 21 having a double-layer structure is provided above the partition wall 23. The two layers of the 1 st outer wall 21 of the double-layer construction are joined to each other. Further, in the 1 st outer wall 21 having the two-layer structure, an opening, not shown, is formed by thermal shrinkage of the thermoplastic resin at the time of molding the core layer 20. In the 1 st cell S1, the 2 nd outer wall 22 having a single-layer structure is provided below the partition wall 23.

On the other hand, as shown in FIG. 3(c), in the 2 nd cell S2, the 1 st outer wall 21 having a single-layer structure is provided above the partition wall 23. In the 2 nd cell S2, the 2 nd outer wall 22 having a double-layer structure is provided below the partition wall 23. The two layers of the 2 nd outer wall 22 of the double layer construction are joined to each other. The No. 2 outer wall 22 having the two-layer structure has an opening, not shown, formed by thermal contraction of the thermoplastic resin during molding of the core layer 20.

As shown in fig. 3(b) and 3(c), the adjacent 1 st cells S1 and the adjacent 2 nd cells S2 are defined by the partition walls 23 having a double-layer structure. The partition wall 23 having the double-layer structure has portions that are not thermally welded to each other in the center portion in the thickness direction of the core layer 20. Therefore, the internal space of each cell S of the core layer 20 communicates with the internal space of the other cell S via the partition walls 23 having the double-layer structure. In fig. 3(b) and 3(c), the cells S on the leftmost side among the plurality of cells S are representatively denoted by reference numerals, but the same applies to the other cells S.

As shown in fig. 3(a), the 1 st cells S1 are arranged in parallel in a row along the X direction. Similarly, the 2 nd cells S2 are juxtaposed in a row along the X direction. The 1 st cell S1 row and the 2 nd cell S2 row are alternately arranged in the Y direction orthogonal to the X direction. The core layer 20 has a honeycomb structure as a whole, with the 1 st cell S1 and the 2 nd cell S2.

The thermoplastic resin constituting the core layer 20 may be any conventionally known thermoplastic resin, and may be, for example, a polypropylene resin, a polyamide resin, a polyethylene resin, an acrylonitrile-butadiene-styrene copolymer resin, an acrylic resin, a polybutylene terephthalate resin, or the like. The core layer 20 of embodiment 1 is made of polypropylene resin.

As shown in fig. 2(b), the steel sheet 43 laminated on the 1 st surface of the core layer 20 is bonded to the core layer 20 through an adhesive layer made of a thermoplastic resin (for example, polypropylene resin) not shown. The steel plates 43 extend to the end edges 51 of the first skin layer 50 or to the vicinity of the end edges 51 at both ends in the longitudinal direction of the deck plate 2. The steel sheet 44 laminated on the 2 nd surface of the core layer 20 is bonded to the core layer 20 by an adhesive layer made of a thermoplastic resin, not shown. The steel plates 44 extend to the ends of the curved portions 62 of the skin layer 60 at both ends in the longitudinal direction of the deck plate 2. That is, the steel plate 44 extends from the position in contact with the bent portion 62 along the flat portion of the 2 nd skin layer 60. The steel plates 43 and 44 are thin plates made of metal such as aluminum alloy, iron alloy, and copper alloy. The thickness of the steel plates 43 and 44 is, for example, about 0.05mm to several mm. In embodiment 1, the steel plate 43 has the same structure as the steel plate 44.

The 1 st skin layer 50 is bonded to the upper surface of the steel plate 43 (the outer surface of the steel plate 43) by an adhesive layer made of a thermoplastic resin (not shown). The skin layer 60 is also bonded to the lower surface of the steel plate 44 (the outer surface of the steel plate 44) by an adhesive layer made of a thermoplastic resin (not shown) in the same manner. The thickness of the skin layers 50 and 60 is, for example, about 0.5mm to several mm. The thermoplastic resin constituting the skin layers 50 and 60 may be any conventionally known thermoplastic resin, and may be, for example, a polypropylene resin, a polyamide resin, a polyethylene resin, an acrylonitrile-butadiene-styrene copolymer resin, an acrylic resin, or a polybutylene terephthalate resin. The thermoplastic resin constituting the skin layers 50 and 60 is preferably the same as the thermoplastic resin constituting the core layer 20, and the skin layers 50 and 60 of embodiment 1 are made of polypropylene resin. In embodiment 1, the thickness of the 1 st skin layer 50 is the same as that of the 2 nd skin layer 60.

The operation of the deck boards 2 of embodiment 1 will be described.

The lower surface 2c of the deck board 2 is entirely smooth. Therefore, when the deck board 2 is placed on the support portion 11, the smooth lower surface 2c is stably supported by the upper surface of the support portion 11. Further, two upper surfaces 2a extending in the longitudinal direction are formed at both ends in the short-side direction in the upper portion of the shelf plate 2, and concave surfaces 2b recessed downward from the end edges of the two upper surfaces 2a extend over the entire length in the longitudinal direction at the center in the short-side direction. Therefore, books, shoes, and the like placed on the concave surface 2b of the shelf plate 2 are hard to fall off. The end face 2d of the deck board 2 is constituted by the end face 63 of the 2 nd skin layer 60, the compressed portion 20a of the core layer 20, and the end edge 61 of the 1 st skin layer 50, and the inclination angle θ is 70 degrees or more. Therefore, a gap is hardly formed between the deck board 2 and the inner surface of the side wall 1c of the storage case 1, or between the deck board 2 and the support portion 11. In addition, the ground contact area between the upper surface of the support portion 11 and the lower surface 2c of the deck plate 2 increases, and the deck plate 2 is stably supported on the support portion 11.

Steel plates 43 and 44 extending over the entire length in the longitudinal direction are joined to substantially the center in the short-side direction of the upper surface and the lower surface of the deck plate 2 to both ends in the longitudinal direction. The steel plates 43, 44 reinforce the deck boards 2. The steel plates 43 and 44 are joined over the entire length in the longitudinal direction, and therefore, flexure at the substantially central portion in the longitudinal direction of the deck plate 2 can be suppressed. In addition, both end portions of the deck plate 2 in the longitudinal direction are reinforced, and the strength of the portion supported by the support portion 11 is improved. Further, the deck boards 2 are lighter than in the case where the steel plates 43, 44 are joined to the entire surfaces of the deck boards 2.

Next, a method of manufacturing the deck boards 2 will be described with reference to fig. 4 and 5. The method of manufacturing the deck boards 2 may comprise: a step of forming a core layer 20; a heating step of heating the core layer 20, the steel sheets 43 and 44, and the skin layers 50 and 60; a joining step of joining the core layer 20, the steel sheets 43 and 44, and the skin layers 50 and 60; a molding step of molding the core layer 20, the steel sheets 43 and 44, and the skin layers 50 and 60 to obtain an intermediate 90; and a post-processing step of finishing the end face shape of the intermediate body 90 to obtain the shelf board 2. In embodiment 1, the joining step of joining the steel plates 43 and 44 and the skin layers 50 and 60 and the molding step of molding the core layer 20, the steel plates 43 and 44, and the skin layers 50 and 60 to obtain the intermediate 90 are performed simultaneously.

First, a process of forming the core layer 20 will be described. The core layer 20 is formed by folding the 1 st sheet 100.

As shown in fig. 4(a), the 1 st sheet 100 is formed by molding a sheet of thermoplastic resin into a predetermined shape. In the 1 st sheet 100, the planar regions 110 and the expanded regions 120 constituting the belt shape are alternately arranged in the longitudinal direction (X direction) of the 1 st sheet 100. The projection region 120 is formed with a 1 st projection 121, the 1 st projection 121 is formed by an upper surface and a pair of side surfaces and has a groove-like shape in cross section, and the 1 st projection 121 extends over the entire extension direction (Y direction) of the projection region 120. The 1 st bulge 121 has a bulge surface bulging from the planar region 110 and two connection surfaces intersecting the bulge surface, and has a shape similar to a groove opening downward. The projection surface of the 1 st projection 121 may be perpendicular to the connection surface. The width of the 1 st projection 121, that is, the length of the projection surface in the short side direction is the same as the width of the planar area 110, and is 2 times the projection height of the 1 st projection 121, that is, the length of the connection surface in the short side direction.

In addition, a plurality of 2 nd bulging portions 122 are formed in the bulging region 120, and the cross-sectional shape of the 2 nd bulging portion 122 is configured as a trapezoidal shape in which a regular hexagon is divided into two by the longest diagonal line. The plurality of 2 nd bulging portions 122 are orthogonal to the 1 st bulging portion 121. The bulging height of the 2 nd bulging portion 122 is set to be the same as the bulging height of the 1 st bulging portion 121. The interval between two adjacent 2 nd projection portions 122 is the same as the width of the projection surface of the 2 nd projection portion 122.

The 1 st bulge 121 and the 2 nd bulge 122 are formed by partially bulging a sheet upward by the plasticity of the sheet. The 1 st sheet 100 can be formed from a single sheet by a known forming method such as a vacuum forming method or a compression forming method.

As shown in fig. 4(a) and 4(b), the core layer 20 is formed by folding the 1 st sheet 100 configured as described above along the boundary line P, Q. In more detail, the 1 st sheet 100 is folded inward along the boundary line P between the planar region 110 and the bulging region 120, and folded outward along the boundary line Q between the bulging surface and the connection surface of the 1 st bulging portion 121, thereby being compressed in the X direction. Next, as shown in fig. 4(b) and 4(c), the bulging surface and the connection surface of the 1 st bulging portion 121 are folded, and the end surface of the 2 nd bulging portion 122 and the planar area 110 are folded. Thereby, a columnar delimiting body 130 extending in the Y direction is formed for one expanded region 120. Such a delimiting body 130 is continuously formed in the X direction, thereby forming the core layer 20 in a hollow plate shape.

When the 1 st sheet 100 is compressed as described above, the portions corresponding to the bulging surface and the joint surface of the 1 st bulging portion 121 form the 1 st outer wall 21 of the core layer 20, and the portions corresponding to the end surface and the planar region 110 of the 2 nd bulging portion 122 form the 2 nd outer wall 22 of the core layer 20. As shown in fig. 4(c), the overlapping portion 131 is formed by a portion of the 1 st outer wall 21 where the bulging surface and the connection surface of the 1 st bulging portion 121 are folded to form a double-layer structure, and a portion of the 2 nd outer wall 22 where the end surface of the 2 nd bulging portion 122 is folded to form a double-layer structure together with the planar region 110.

In addition, the hexagonal columnar shaped region defined by the 2 nd bulge 122 being folded constitutes the 2 nd cell S2, and the hexagonal columnar shaped region defined between the adjacent two defining bodies 130 constitutes the 1 st cell S1. In the 1 st embodiment, the bulging surface and the connection surface of the 2 nd bulging portion 122 constitute the partition wall 23 of the 2 nd cell S2, and the connection surface of the 2 nd bulging portion 122 and the flat portion between the 2 nd bulging portion 122 in the bulging region 120 constitute the partition wall 23 of the 1 st cell S1. Further, the abutting portion of the bulging surfaces of the 2 nd bulging portion 122 and the abutting portion of the above-described flat portions in the bulging region 120 constitute the partition wall 23 having a double-layer structure. In addition, when performing such a folding process, the 1 st sheet 100 may be heated and softened.

Next, a heating step of heating the core layer 20, the steel sheets 43 and 44, and the skin layers 50 and 60 will be described.

As shown in fig. 5(a), first, in order to prepare the core layer 20 to be used for the deck boards 2, the core layer 20 manufactured by the above-described method is cut into a shape larger than the deck boards 2. For example, the core layer 20 manufactured by the above method is cut into a rectangular shape that is approximately 50mm larger in the longitudinal direction and the short side direction than the size of the deck board 2. In fig. 5, the hollow structure of the core layer 20 is not shown.

As the steel plates 43 and 44 used for the deck plates 2, steel plates cut so that the length of the long side is slightly shorter than the length of the long side of the deck plate 2 and the length of the short side is about 1/3 to 1/2 of the length of the short side of the deck plate 2 are prepared. The steel plates 43 and 44 are coated with adhesive layers made of thermoplastic resin (for example, polypropylene resin) on both surfaces thereof. The skin layers 50, 60 used in the manufacture of the deck boards 2 are cut into a shape larger than the deck boards 2, specifically, into a size approximately equal to the core layer 20.

As shown in fig. 5(b), the core layer 20, the steel sheets 43 and 44, and the skin layers 50 and 60 are heated. When the core layer 20 is heated, the core layer 20 is placed in a heating furnace 71 set at a predetermined temperature and held for a predetermined time. When the steel plates 43 and 44 are heated, the steel plates 43 and 44 are placed in the heating furnace 72 set at a predetermined temperature and held for a predetermined time. Similarly, the skin layers 50 and 60 are placed in the heating furnace 73 set at a predetermined temperature, and held for a predetermined time. The temperature in the heating furnaces 71, 72, 73 is set to a level at which the thermoplastic resins constituting the core layer 20 and the skin layers 50, 60 are melted. The temperature in the heating furnace 72 for heating the steel sheets 43 and 44 is set to be higher than the temperature in the heating furnace 71 for heating the core layer and the temperature in the heating furnace 73 for heating the skin layers 50 and 60.

In embodiment 1, in the heating step, the surface temperature of the core layer 20 held in the heating furnace 71 is adjusted so as to be different depending on the location. For example, the surface temperature of the core layer 20 can be made different by providing a shielding member locally on the surface of the core layer 20. The shielding member has holes formed therein, and the size and number of the holes are adjusted so that the surface temperature of the portion where the shielding member is provided can be adjusted to be lower than the temperature in the heating furnace 71. Further, the surface temperature may be adjusted by providing a shielding member having no hole.

Next, a method of adjusting the surface temperature of the core layer 20 by providing the shielding member will be described. In the core layer 20, shielding members having a relatively small size of holes and/or shielding members having a relatively small number of holes are provided in portions corresponding to the upper surface 2a and portions corresponding to the lower surface 2c of the deck board 2 manufactured through the above-described steps. Further, a shielding member having a relatively large hole size and/or a shielding member having a relatively large number of holes is provided at a portion corresponding to the concave surface 2b of the deck plate 2. The other portions are not provided with the shielding members. Thus, the heating temperature in the heating furnace 71 is relatively minimized at the portions corresponding to the upper surfaces 2a and the lower surfaces 2c of the shelf boards 2, and the surface temperature of the portions corresponding to the concave surfaces 2b of the shelf boards 2 is relatively second minimized, so that the surface temperature of the other portions can be made to be the same as the heating temperature in the heating furnace 71. The other portion is a portion corresponding to the end face 2d of the deck board 2, and is a portion corresponding to a compressed portion 91 of the intermediate body 90 described later.

Next, a bonding step and a molding step for bonding the core layer 20, the steel sheets 43 and 44, and the skin layers 50 and 60 will be described. In the joining step and the forming step, the 2 nd skin layer 60, the steel sheet 44, the core layer 20, the steel sheet 43, and the 1 st skin layer 50 stacked in this order from below are referred to as a stack. In the joining step, the laminate is molded to produce an intermediate body 90.

As shown in fig. 5(c), the mold used in the joining step and the molding step includes an upper mold 81 and a lower mold 82. Fig. 5(c) to (f) are views seen from the short side of the manufactured deck boards 2. The upper die 81 and the lower die 82 of embodiment 1 are not heated as a whole and are kept at normal temperature.

The lower die 82 has a recess 82a recessed in a rectangular shape in plan view. The length of the concave portion 82a in the longitudinal direction is substantially the same as the length of the deck plate 2 in the longitudinal direction, and the length of the concave portion 82a in the short direction is substantially the same as the length of the deck plate 2 in the short direction. In addition, the depth of the recess 82a is substantially the same as the thickness in the concave surface 2b of the deck board 2. The size of the recess 82a is preferably set in consideration of the heat shrinkage of the core layer 20, the steel plates 43, 44, and the skin layers 50, 60. Hereinafter, it is preferable to consider the influence of thermal shrinkage in forming each portion.

The upper die 81 has recesses 81a and 81b, which are grooves extending in a rectangular shape in plan view. The depth of the recesses 81a and 81b is substantially the same as the thickness of the compression portion 91 of the intermediate body 90 described later. The concave portion 81a is a portion for molding the upper surface 2a of the deck board 2 in a molding step described later, and the concave portion 81b is a portion for molding the compressed portion 91 of the intermediate body 90. That is, as shown by the broken line in fig. 5(c), the recessed portion 81a is a portion located inward of the outer edge of the recessed portion 82a of the lower mold 82 when the upper mold 81 and the lower mold 82 are clamped, and the recessed portion 81b is a portion located outward of the outer edge of the recessed portion 82a of the lower mold 82. The rectangular portions in plan view surrounded by the concave portions 81a and 81b (for convenience, referred to as convex portions 81 c) are portions for molding the concave surfaces 2b of the shelf boards 2.

As shown in fig. 5(c), first, the core layer 20, the steel plates 43 and 44, and the skin layers 50 and 60 to be heated are placed on the lower die 82 in the order of the skin layer 60, the steel plate 44, the core layer 20, the steel plate 43, and the skin layer 50 in order from below so as to cover the recess 82 a. Thereby, the core layer 20, the steel sheets 43 and 44, and the skin layers 50 and 60 form a laminate. The core layer 20 and the skin layers 50 and 60 of the laminate are cut into a rectangular shape larger than the shelf board 2. Therefore, in a state where the laminate is placed on the lower die 82, the four sides of the laminate are covered with the outer edges of the concave portions 82 a.

In the previous heating step, since the surface temperature of the core layer 20 is varied depending on the location, when the laminate is placed, the laminate is positioned with respect to the dies 81 and 82 depending on the surface temperature of the core layer 20. More specifically, the portion of the laminated body whose surface temperature has been adjusted as the portion corresponding to the upper surface 2a of the deck board 2 is aligned with the position of the concave portion 81a of the upper die 81, and the portion of the laminated body whose surface temperature has been adjusted as the portion corresponding to the concave surface 2b of the deck board 2 is aligned with the position of the convex portion 81c of the upper die 81. That is, the laminate is positioned according to the height of the space between the upper mold 81 and the lower mold 82 formed when the upper mold 81 and the lower mold 82 are clamped, and the portion of the laminate adjusted to the relatively lowest surface temperature in the previous heating step is disposed in the recess 81a having the highest height of the space, and the portion of the laminate having the highest surface temperature in the previous heating step is disposed in the recess 81b having the lowest height of the space. In other words, in the heating step, the surface temperature of the core layer 20 is adjusted according to the height of the space between the upper mold 81 and the lower mold 82 when the molds are closed.

In a state where the laminate is placed on the lower die 82, a part of the thermoplastic resin of the adhesive layer applied to both surfaces of each of the heated steel sheets 43 and 44 is thermally melted. Therefore, the core layer 20, the steel plates 43 and 44, and the skin layers 50 and 60 constituting the laminate are positioned in a state of being temporarily bonded to the lower mold 82.

Next, the upper mold 81 is lowered toward the lower mold 82 to mold the mold, and the laminate is pressed to simultaneously perform the joining step and the molding step. A plurality of suction holes, not shown, are formed in the upper mold 81 and the lower mold 82, and suction is performed through the suction holes during mold clamping, so that the stacked body can be brought into close contact with the molds 81 and 82 in a state where the stacked body is positioned in the molds 81 and 82. The pressing pressure and pressing time may be appropriately set.

In the heating step of embodiment 1, the temperature in the heating furnace 71 for heating the steel sheets 43 and 44 is set higher than the temperature in the heating furnace 71 for heating the core layer and the temperature in the heating furnace 73 for heating the skin layers 50 and 60. Therefore, when the dies are clamped, the adhesive layers on both surfaces of the steel sheets 43 and 44 are thermally fused, and the heat of the steel sheets 43 and 44 is transferred to the core layer 20 and the skin layers 50 and 60, so that a part of the thermoplastic resin is thermally fused. Therefore, the core layer 20, the steel plates 43 and 44, and the skin layers 50 and 60 are joined by clamping the dies 81 and 82. At this time, the opening portions are formed in the 1 st outer wall 21 of the 1 st cell S1 and the 2 nd outer wall 22 of the 2 nd cell S2 of the core layer 20, and the partition walls 23 are not thermally welded to each other in the central portion in the thickness direction of the core layer 20. Therefore, air between the core layer 20 and the steel plates 43 and 44 and the skin layers 50 and 60 easily leaks from the openings of the 1 st outer wall 21 and the 2 nd outer wall 22 of the core layer 20 and the gaps in the core layer 20. This makes it difficult to accumulate air between the core layer 20 and the steel plates 43 and 44 and the skin layers 50 and 60, and improves the bonding strength between the core layer 20 and the steel plates 43 and 44 and the skin layers 50 and 60.

As shown in fig. 5(d), the laminate is molded into the inner surface shapes of the upper mold 81 and the lower mold 82, that is, the shapes of the concave portions 81a, 81b, 82a and the convex portion 81c, to form an intermediate body 90.

As shown in fig. 5(c), the concave portion 81b of the upper mold 81 faces an upper end surface of the concave portion 82a of the lower mold 82, which is an outer side when the mold is closed. Therefore, the height of the recess 81b is the lowest in the space between the upper mold 81 and the lower mold 82 when the molds are closed. In the concave portion 81b, a portion whose surface temperature is adjusted to be the highest is disposed in the heating step. The portions are clamped, the thermoplastic resin constituting the core layer 20 is melted, and the core layer 20 is thermally compressed, thereby forming the compressed portions 91 of the intermediate body 90. In the compression portion 91, the thermoplastic resin constituting the 1 st outer wall 21, the 2 nd outer wall 22, and the partition wall 23 is melted and integrated.

When the mold is closed, the convex portion 81c of the upper mold 81 faces the concave portion 82a of the lower mold 82. Therefore, the space between the convex portion 81c and the concave portion 82a is a slightly higher portion of the space between the upper mold 81 and the lower mold 82 when the molds are closed. In this space, a portion whose surface temperature is adjusted to be relatively low is disposed in the heating step. This portion is clamped to melt a part of the thermoplastic resin constituting the core layer 20, thereby making the core layer 20 thin in the vertical direction. At this time, since heat is less likely to be transmitted to the inner partition walls 23 than the outer walls 21 and 22, the partition walls 23 are not integrated with the outer walls 21 and 22, and the shape thereof can be maintained, and the core layer 20 is not deformed.

When the mold is closed, the concave portion 81a of the upper mold 81 faces the concave portion 82a of the lower mold 82. Therefore, the space between the concave portion 81a and the concave portion 82a is the highest height of the space between the upper mold 81 and the lower mold 82 when the molds are closed. In this space, a portion whose surface temperature is adjusted to be the lowest is disposed in the heating step. This portion does not melt the thermoplastic resin constituting the core layer 20 due to mold clamping, and the core layer 20 does not deform in the vertical direction and has a shape in which the height dimension thereof is maintained.

When the core layer 20, the steel plates 43 and 44, and the skin layers 50 and 60 are pressed into the recess 82a of the lower die 82 by clamping, the 2 nd skin layer 60 is bent toward the 1 st skin layer 50 to form the bent portion 62. At this time, of the core layer 20 and the skin layers 50 and 60, the portions corresponding to the lower surface 2c and the upper surface 2a of the deck board 2 are adjusted to the lowest surface temperatures, and the other portions, that is, the portions corresponding to the end surfaces 2d of the deck board 2 and the portions corresponding to the compressed portions 91 of the intermediate body 90 are adjusted to the highest surface temperatures. Therefore, when the skin layer 60 located below is bent, the temperature difference between the portion corresponding to the lower surface 2c of the deck board 2 and the portion corresponding to the end surface 2d of the deck board 2 becomes large, the degree of melting of the thermoplastic resin becomes poor, and the length of the bent portion 62 formed in the skin layer 60 becomes small. On the other hand, the 1 st skin layer 50 is not bent and is maintained in a horizontally extending state.

As shown in fig. 5(e), the intermediate body 90 is taken out from the lower die 82 after the upper die 81 is separated from the lower die 82 and the intermediate body 90 is cooled. In the core layer 20 of the intermediate 90 obtained through the joining step and the molding step, the steel sheet 43 and the 1 st skin layer 50 are joined to the 1 st surface, and the steel sheet 44 and the 2 nd skin layer 60 are joined to the 2 nd surface. The intermediate body 90 includes a compressed portion 91 formed over the entire periphery of the side edge, and the compressed portion 91 is a portion having a size and shape corresponding to the deck board 2.

The intermediate body 90 has a bent portion 62 in which the 2 nd skin layer 60 is bent, and has an end face 63 that covers the core layer 20 from the side. The 2 nd skin layer 60 extends horizontally from the upper edge of the end face 63. The 1 st skin layer 50 extends entirely horizontally. In the compressed portion 91, the compressed portion 20a of the core layer 20 is interposed between the 1 st skin layer 50 and the 2 nd skin layer 60 extending horizontally.

Next, a post-processing step of the end face shape of the intermediate body 90 will be described.

As shown in fig. 5(f), the compressed portion 91 formed in the intermediate body 90 is cut by a cutting tool (not shown). Thereby, for example, a part of the outer edge of the portion of the core layer 20 including the compressed first row of cell rows is cut off. As shown in fig. 2(a) and 2(b), in the cut surface of the intermediate body 90, the compressed portion 20a of the core layer 20 is exposed between the end edge 51 of the 1 st skin layer 50 and the end edge 61 of the 2 nd skin layer 60, and the end edge 51 of the 1 st skin layer 50, the end surface 63 of the 2 nd skin layer 60, and the compressed portion 20a of the core layer 20 form the end surface 2d of the shelf board 2. Thereafter, the cut surface of the intermediate body 90 is polished, coated, or the like, to finish the shape of the end face 2 d. When a thomson blade, a laser, or the like is used as a cutting tool for cutting the compressed portion 91, it is not necessary to perform a process such as grinding or coating.

The deck boards 2 are manufactured through the above manufacturing process.

Next, the operation of the method of manufacturing the deck boards 2 of embodiment 1 will be described.

In embodiment 1, the core layer 20, the steel sheets 43 and 44, and the skin layers 50 and 60 are heated to a predetermined temperature by a heating process before the joining process. Therefore, the thermoplastic resin of the adhesive layers applied to both surfaces of the steel sheets 43 and 44 is partially thermally melted, and the core layer 20, the steel sheets 43 and 44, and the skin layers 50 and 60 are easily positioned.

In the heating step of embodiment 1, the temperature in the heating furnace 71 for heating the steel sheets 43 and 44 is set to be higher than the temperature in the heating furnace 71 for heating the core layer and the temperature in the heating furnace 73 for heating the skin layers 50 and 60. Therefore, the adhesive layers coated on both surfaces of the steel sheets 43 and 44 are thermally fused, and the heat transfer of the steel sheets 43 and 44 thermally fuses a part of the thermoplastic resins constituting the core layer 20 and the skin layers 50 and 60, and the plurality of layers constituting the laminate are joined to each other by clamping the dies 81 and 82.

In the heating step of embodiment 1, the surface temperature of the core layer 20 is adjusted to be different depending on the location by providing the shielding member. Therefore, by performing mold clamping in the subsequent joining step and molding step, the core layer 20 is deformed in the thickness direction while being thermally melted in the concave portion 81b, and the 1 st outer wall 21, the 2 nd outer wall 22, and the partition wall 23 of the core layer 20 are integrated. In the space formed by the projection 81c, a part of the core layer 20 is slightly thinned in the thickness direction while being thermally melted, and the partition walls 23 of the core layer 20 are bent or inclined. In the space formed by the recessed portion 81a, the core layer 20 is not thermally melted and is not deformed, and the shape and size of the cells S of the core layer 20 are maintained.

Further, by using the shielding member in the heating step, the surface temperature of the portion of the stacked body forming the upper surface 2a and the portion forming the lower surface 2c of the shelf board 2 is adjusted to be relatively lowest, and the surface temperature of the portion forming the compressed portion 91 of the intermediate body 90 is adjusted to be relatively highest. Therefore, in the laminated body, the temperature difference between the portion where the upper surface 2a is formed and the portion where the compression portion 91 of the intermediate body 90 is formed becomes large, and the temperature difference between the portion where the lower surface 2c is formed and the portion where the end surface 2d is formed becomes large. By performing the mold clamping in the subsequent joining step and molding step, the boundary between the compressed portion and the uncompressed portion of the core layer 20 becomes clear, and therefore the curvature of the bent portion 62 of the 2 nd skin layer 60 becomes large, and the inclination angle θ of the end surface 2d of the deck board 2 becomes large.

More specifically, the plurality of cells S arranged along the side edge form a cell row, and the core layer 20 includes a first row, a second row, and a third row of cell rows arranged in this order from the side edge to the inside in the direction intersecting the side edge. The cells S in the first and second cell rows are compressed in the thickness direction. On the other hand, the cells S in the third row cell array are not compressed, and the partition walls 23 thereof are kept straight.

When the heated core layer 20 and skin layers 50 and 60 are taken out from the heating furnaces 71 and 73, the temperature thereof decreases, and the thermoplastic resin constituting the core layer 20 and the skin layers 50 and 60 shrinks. However, in the heating step of embodiment 1, the heating temperature of the steel sheets 43 and 44 is set to be higher than the heating temperature of the core layer 20 and the skin layers 50 and 60, and in the joining step and the forming step, the heated steel sheets 43 and 44 are laminated so as to be sandwiched between the core layer 20 and the skin layers 50 and 60, and therefore, the shrinkage of the core layer 20 and the skin layers 50 and 60 is suppressed by the steel sheets 43 and 44 having a small linear expansion coefficient. As a result, the transfer to the dies 81 and 82 becomes excellent, and the laminate easily adheres to the dies 81 and 82, so that the dimensional accuracy of the deck board 2 is improved. In addition, the inclination angle of the end face 2d can be formed to be a steep angle.

The range of the compressed cells S can be adjusted by adjusting the surface temperature of the core layer 20 in the heating step and adjusting the pressing pressure and pressing time in the dies 81 and 82. For example, the following conditions may be changed: the conditions are changed so that the cells S in the first row are compressed in the thickness direction from the side edge inward, while the cells S in the second row are not compressed. At this time, the boundary between the portion of the core layer 20 that is compressed and the portion that is not compressed becomes clearer.

According to embodiment 1, the following effects can be obtained.

(1-1) the deck boards 2 are applied to the storage box and supported by support portions 11 formed in the storage box 1. The inclination angle of the end face 2d at the side edge of the shelf plate 2 is 70 degrees or more. Therefore, a gap is hardly formed between the support portion 11 and the end surface 2d, and foreign matter such as dust or dirt is hardly accumulated between the support portion 11 and the deck plate 2. In addition, since the inclination angle of the end surface 2d is steep, the installation area of the lower surface of the deck board 2 on the support portion 11 is easily secured. Therefore, even if the support portion 11 is not formed large, the shelf plate 2 can be stably supported by the support portion 11.

(1-2) in the end face 2d of the deck board 2, the compressed portion 20a of the core layer 20 is interposed between the 1 st skin layer 50 and the 2 nd skin layer 60. The compressed portion 20a of the core layer 20 is melted and then cooled and solidified by the thermoplastic resin constituting the core layer 20, and the 1 st outer wall 21, the 2 nd outer wall 22, and the partition walls 23 become an integrated block. Therefore, the rigidity of the end surface 2d is improved, and the deck plate 2 can be stably supported by the support portion 11.

(1-3) in the side edges of the shelf plate 2, the cells S in the first row and the second row of the cell array of the core layer 20 are compressed in the thickness direction, while the cells S in the third row of the cell array are not compressed, and the partition walls 23 thereof are maintained in the standing state. As described above, the honeycomb structure of the core layer 20 is maintained also at the side edges, and therefore the strength of the deck board 2 is maintained.

(1-4) the 1 st skin layer 50 extends horizontally without being bent in the side edges of the deck boards 2. Therefore, the area of the upper surface, which is the surface on which the object is placed on the deck boards 2, can be secured large.

(1-5) the deck plate 2 incorporates steel plates 43, 44 extending over the entire length in the longitudinal direction to both ends in the longitudinal direction. This improves the rigidity of the deck boards 2, and suppresses flexure of the deck boards 2 when a heavy object is placed on the deck boards 2. In addition, since the deck boards 2 are reinforced by the steel plates 43, 44 extending in the longitudinal direction of the deck boards 2, the deck boards 2 can be stably supported by the support portions 11.

(1-6) in the upper portion of the shelf plate 2, in the center portion in the short side direction, a concave surface 2b recessed downward from the end edge of the upper surface 2a extends over the entire length in the long side direction. As a result, the front side and the back side of the upper surface 2a of the deck plate 2 are relatively high, and therefore, an object placed on the deck plate 2 is less likely to fall.

(1-7) in manufacturing the deck board 2, first, the core layer 20, the steel sheets 43 and 44, and the skin layers 50 and 60 are heated in advance in a heating step, and then placed on the lower die 82 in an aligned state as a stacked body. Further, both surfaces of the steel plates 43 and 44 are coated with adhesive layers made of thermoplastic resin. Accordingly, the core layer 20 and the 1 st skin layer 50 are temporarily bonded to the lower surface and the upper surface of the steel plate 43, respectively, and the core layer 20 and the 2 nd skin layer 60 are temporarily bonded to the upper surface and the lower surface of the steel plate 44, respectively. This enables the core layer 20, the steel plates 43, 44, and the skin layers 50, 60 to be positioned with high accuracy.

(1-8) in the heating step, the core layer 20, the steel sheets 43 and 44, and the skin layers 50 and 60 are heated by separate heating furnaces 71, 72, and 73, respectively. Therefore, temperature adjustment and temperature control of each member are facilitated. In addition, each member can be heated to a uniform temperature.

(1-9) the core layer 20 and the skin layers 50 and 60 taken out of the heating furnaces 71 and 73 are lowered in temperature to shrink the thermoplastic resin. However, by bonding the steel sheets 43 and 44 having a small linear expansion coefficient in advance in the bonding step and the forming step, shrinkage of the core layer 20 and the skin layers 50 and 60 is suppressed. Therefore, the transfer of the molds 81 and 82 is improved, and the shelf plate 2 can be molded with high accuracy. In addition, the inclination angle θ of the end face 2d can be formed to be a steep angle.

(1-10) in embodiment 1, the joining step and the molding step are performed simultaneously by press-molding using the dies 81 and 82. Therefore, the process is simplified, and the method is advantageous in terms of workability and cost.

(1-11) the molds 81 and 82 are formed with a plurality of suction holes. Therefore, the laminated body formed of the core layer 20, the steel plates 43, 44, and the skin layers 50, 60 can be brought into close contact with the dies 81, 82 in a state of being positioned with respect to the dies 81, 82 at the time of mold clamping. Therefore, the stacked body can be molded so as to follow the shape of the inner space of the molds 81 and 82.

(1-12) in the heating step of embodiment 1, the surface temperature of the core layer 20 is adjusted to be different depending on the location by providing the shielding member. Therefore, in the joining step and the molding step which are continued thereafter, the portions having different thicknesses, such as the concave surface 2b and the compressed portion 91, can be molded at the same time by one press without heating the dies 81 and 82. This simplifies the process and is advantageous in terms of workability and cost.

(1-13) providing the shielding member in the heating process increases the temperature difference between the portion aligned with the recessed portion 81a of the upper mold 81 and the portion aligned with the recessed portion 81b of the upper mold 81 in the core layer 20. Therefore, the boundary between the compressed portion and the uncompressed portion of the core layer 20 can be clarified.

(1-14) by providing the shielding member in the heating process, the temperature difference between the portion corresponding to the lower surface 2c of the deck board 2 and the portion corresponding to the end surface 2d in the core layer 20 is made large. Therefore, the curvature of the curved portion 62 of the skin layer 60 can be increased, and the inclination angle θ of the end surface 2d of the deck board 2 can be made large.

(1-15) in the heating step, the temperature in the heating furnace 71 for heating the steel sheets 43 and 44 is set higher than the temperature in the heating furnace 71 for heating the core layer and the temperature in the heating furnace 73 for heating the skin layers 50 and 60. Therefore, a part of the thermoplastic resin constituting the core layer 20 and the skin layers 50 and 60 is thermally melted by the heat of the steel plates 43 and 44, and the core layer 20, the steel plates 43 and 44, and the skin layers 50 and 60 can be bonded to the entire surfaces by clamping the dies 81 and 82.

Embodiment 1 may be modified as described below, and these modifications may be applied in appropriate combinations.

In embodiment 1, although the case where the hollow plate material is applied to the deck boards 2 of the storage box has been described, the hollow plate material of the present disclosure is not limited to the deck boards 2, and can be used as any plate-like member. For example, the hollow plate material of the present disclosure may be applied to a luggage board for a vehicle, a work scaffold for construction, and the like. When applied to a luggage board, the luggage board can be stably supported without making a support portion for supporting the luggage board large, and therefore, the capacity of the luggage under the luggage board can be ensured to be large. Further, since the gap between the end face of the luggage board and the support portion can be reduced, it is possible to suppress transmission of sounds from below the vehicle, such as frictional sounds between the road and the tire, into the vehicle. The shape of the hollow plate material, the material of the joining portions of the steel plates 43 and 44, the skin layers 50 and 60, and the like can be changed according to the shape of the portion where the hollow plate material is disposed.

The shelf board 2 of embodiment 1 has a smooth lower surface 2c at the lower part and an upper surface 2a and a concave surface 2b at the upper part. The shelf board 2 may have a smooth surface on the upper portion and a lower surface 2c and a concave surface 2b on the lower portion, or may have concave surfaces 2b on both the upper and lower portions. Further, concave portions, convex portions, or the like may be formed on the concave surface 2b or the lower surface 2 c. For example, a concave portion may be formed on the lower surface 2c to mount a spotlight. Further, a through hole penetrating the deck board 2 in the thickness direction may be formed as a handle for pulling out the deck board 2, or a handle as a member separate from the deck board 2 may be attached to the through hole. In forming such a shape such as a concave portion, a convex portion, or a through hole, similarly to the shelf board 2 of embodiment 1, a mold having a shape corresponding to the concave portion, the convex portion, or the through hole may be prepared, and the surface temperature may be appropriately adjusted to form the concave portion, the convex portion, or the through hole. In addition, when the recess or the through hole is formed, the hollow plate material may be cut. In this case, the end face of the cut recess or through hole may be sealed by heat fusion.

The deck boards 2 according to embodiment 1 may include reinforcing portions according to embodiment 2 described later at the corner portions.

The hollow plate may not be a smooth plate, and may be a curved plate, for example.

In the side ends of the deck board 2 according to embodiment 1, the 2 nd skin layer 60 is bent, and the 1 st skin layer 50 extends horizontally without being bent. The shape of the skin layers 50 and 60 is not limited thereto. For example, the 1 st skin layer 50 may be bent at the side ends of the deck board 2, and the 2 nd skin layer 60 may extend horizontally without being bent.

As shown in fig. 6(a), the 1 st skin layer 50 may be slightly bent toward the 2 nd skin layer 60, and the 2 nd skin layer 60 bent toward the 1 st skin layer 50 may cover most of the side surface of the core layer 20. The end face 2d of the deck board 2 is formed at the end face 63 of the 2 nd skin layer 60, the compressed portion 20a of the core layer 20, and the folded portion of the 1 st skin layer 50, but in this case, the ratio of the 1 st skin layer 50 to the end face 2d of the deck board 2 is smaller than the ratio of the 2 nd skin layer 60.

As another example, as shown in fig. 6(b), the compressed portion 20a of the core layer 20 may be sandwiched between the end edge 51 of the 1 st skin layer 50 and the end edge 61 of the 2 nd skin layer 60 at an intermediate position in the vertical direction of the deck board 2. At this time, the end face 53 of the 1 st skin layer 50 becomes a steep slope slightly expanding outward as going downward, and the end face 63 of the 2 nd skin layer 60 becomes a steep slope slightly expanding outward as going upward.

The inclination angle θ of the end face 2d of the shelf board 2 when the skin layers 50, 60 are folded together is defined as follows. As shown in fig. 6(a), when the ratio of the bent portion of one skin layer is smaller than the ratio of the bent portion of the other skin layer at the side edge of the deck board 2 in the skin layers 50 and 60, no end face is formed at the portion of one skin layer that is continuous with the bent portion (52 or 62), and an end face (63 or 53) is formed only at the portion of the other skin layer that is continuous with the bent portion, the inclination angle θ of the end face 2d of the deck board 2 is such that the inclination angle of the end face (63 or 53) of the other skin layer is θ. As shown in fig. 6(b), when the skin layers 50 and 60 are bent at all the side edges of the deck board 2 to form the bent portions 52 and 62, respectively, and the end surfaces 53 and 63 are connected to the bent portions 52 and 62, respectively, the inclination angle θ of the end surface 2d of the deck board 2 is an inclination angle θ 1 of the end surface 53 and an inclination angle θ 2 of the end surface 63. When the inclination angle θ 1 of the end surface 53 is different from the inclination angle θ 2 of the end surface 63, the larger of the inclination angles θ 1 and θ 2 is the inclination angle θ of the end surface 2 d.

Although the steel plates 43 and 44 are joined to the 1 st surface and the 2 nd surface of the core layer 20, respectively, the steel plates may be joined to only one surface of the core layer 20. Further, a steel sheet may be joined to the entire 1 st surface and/or 2 nd surface of the core layer 20.

The steel plates 43 and 44 divided into a plurality may be joined to the 1 st surface and the 2 nd surface of the core layer 20, respectively. The number of steel sheets to be joined, the joint portions, the sizes, and the like may be different between the 1 st surface and the 2 nd surface of the core layer 20.

The steel plates 43 and 44 may not be provided.

Although the steel plates 43 and 44 are formed of metal thin plates, a thin plate made of a fiber-reinforced resin including a material having a high tensile modulus, such as carbon fibers or glass fibers, may be joined to the core layer 20 instead of the steel plates 43 and 44.

Although the skin layers 50 and 60 of embodiment 1 are formed of a sheet made of a thermoplastic resin, at least one of the skin layers 50 and 60 may be formed of a nonwoven fabric. For example, when the skin layer 50 is a nonwoven fabric, an adhesive layer made of a thermoplastic resin (for example, a polypropylene resin) may be applied to the lower surface of the nonwoven fabric, and the skin layer may be joined to the upper surface of the steel plate 43 (the outer surface of the steel plate 43) as the nonwoven fabric through the adhesive layer. The nonwoven fabric constituting the skin layers 50, 60 can be formed from various conventionally known fibers such as polyamide fibers, aramid fibers, cellulose fibers, polyester fibers, polyethylene fibers, polypropylene fibers, rayon fibers, and glass fibers. When both the skin layers 50 and 60 are nonwoven fabrics, the skin layer 50 and the skin layer 60 may have the same structure or different structures.

The heating temperature in the heating step can be appropriately set according to the material of the thermoplastic resin constituting the core layer 20, the material of the metal constituting the steel sheets 43 and 44, the material of the thermoplastic resin constituting the skin layers 50 and 60, the material of the thermoplastic resin constituting the coated adhesive layers of the steel sheets 43 and 44, and the like. The heating temperature in the heating step can be changed according to the degree of deformation of the core layer 20.

In the heating step of embodiment 1, the core layer 20, the steel sheets 43 and 44, and the skin layers 50 and 60 are heated in the separate heating furnaces 71, 72, and 73, respectively, but the present invention is not limited thereto. For example, the steel sheets 43 and 44 and the skin layers 50 and 60 having similar heating temperatures may be heated in the same furnace.

The heating in the heating step may be performed in an open environment, instead of the heating in the heating furnaces 71, 72, 73. For example, the heating may be performed by a burner, an IH heater, or an infrared heater.

In the heating step, the steel sheets 43 and 44 may be previously positioned on the 1 st and 2 nd surfaces of the core layer 20, respectively, and heated. Thus, the steel plates 43 and 44 are temporarily joined to the core layer 20 to perform positioning, and therefore, the displacement of the steel plates 43 and 44 is suppressed. Further, the steel sheets 43 and 44 suppress a temperature decrease of the core layer 20 and suppress heat shrinkage of the core layer 20 before the joining step and the molding step. As a result, the transfer to the molds 81 and 82 becomes favorable.

In the heating step of embodiment 1, the temperature in the heating furnace 72 that heats the steel sheets 43 and 44 is set to be higher than the temperature in the heating furnace 71 that heats the core layer and the temperature in the heating furnace 73 that heats the skin layers 50 and 60, but the temperature in the heating furnaces 71, 72, and 73 is not limited to this. The temperatures in the heating furnaces 71, 72, 73 may be set to the same temperature at which the thermoplastic resins constituting the core layer 20 and the skin layers 50, 60 are melted. Even in this case, in a state where the core layer 20, the steel plates 43 and 44, and the skin layers 50 and 60 are placed on the lower mold 82, a part of the thermoplastic resin of the adhesive layers applied to both surfaces of the heated steel plates 43 and 44 is thermally melted, and the core layer 20, the steel plates 43 and 44, and the skin layers 50 and 60 are temporarily joined to the lower mold 82 and positioned. In the joining step, the adhesive layers on both surfaces of the steel sheets 43 and 44 are thermally fused, and part of the thermoplastic resin constituting the core layer 20 and the skin layers 50 and 60 is thermally fused, whereby the core layer 20, the steel sheets 43 and 44, and the skin layers 50 and 60 are joined.

In embodiment 1, the surface temperature of the core layer 20 is adjusted to be different from portion to portion by providing the shielding member on the surface of the core layer 20 in the heating step. The steel sheets 43 and 44 and the skin layers 50 and 60 may have different surface temperatures at different locations in the heating step.

In embodiment 1, the surface temperature of the core layer 20 is adjusted to be different depending on the location in the heating step. Alternatively, or in addition to this, the heating temperature of the surface of the core layer 20 may be varied depending on the location in the bonding step and the molding step. At this time, shielding members such as punching metal, wire mesh, or steel plate are provided in the concave portions 81a and 81b and the convex portion 81c of the upper die 81 and the concave portion 82a of the lower die 82 to block heat. Similarly to the heating step of embodiment 1, the surface temperatures of the concave portions 81a and 82a and the convex portion 81c can be adjusted by changing the size, number, and the like of the holes formed in the shielding member. For example, the shielding member may be provided appropriately on the horizontal surface of the concave portion 81a of the upper die 81 corresponding to the upper surface 2a of the shelf plate 2 and the horizontal surface of the concave portion 82a of the lower die corresponding to the concave surface 2 b.

More specifically, the heating temperature of the dies 81 and 82 is set to a temperature higher than the melting temperature of the thermoplastic resin of the adhesive layer applied to the steel sheets 43 and 44 and higher than the melting temperature of the thermoplastic resin constituting the core layer 20 and the skin layers 50 and 60, and the shielding members are provided on the horizontal surface of the recessed portion 81b and the horizontal surface of the recessed portion 82a corresponding to the compressed portion 91 of the intermediate body 90. Thereby, the surface temperature of the horizontal surfaces of the concave portions 81a and 82a is set to a relatively lowest temperature, the surface temperature of the convex portion 81c is set to a second lowest temperature, and the surface temperature of the concave portion 81b is set to a relatively highest temperature.

By the adjustment as described above, in the concave portion 82a of the lower die 82, the temperature difference between the horizontal plane and the side surface can be increased. In addition, the temperature difference between the horizontal surface of the recess 81a and the recess 81b of the upper die 81 can be increased. Therefore, the portions of the core layer 20 and the skin layers 50 and 60 that are in contact with the horizontal surfaces of the recessed portions 81a and 82a are hardly melted, while the portions of the core layer 20 and the skin layers 50 and 60 that are in contact with the side surfaces of the recessed portions 81b and 82a of the upper mold 81 are melted, and the core layer and the skin layers 50 and 60 are bent while the boundary portion between the melted portion and the hardly melted portion is a boundary. By setting the temperature difference to be large, the curvature of the bending angle of the boundary portion can be increased, and as a result, the inclination angle of the end surface 2d of the deck plate 2 can be increased.

The intermediate body 90 can also be produced as in embodiment 1 by heating the molds 81 and 82.

In embodiment 1, the joining step of joining the steel plates 43 and 44 and the skin layers 50 and 60 and the molding step of molding the core layer 20, the steel plates 43 and 44, and the skin layers 50 and 60 to obtain the intermediate 90 are performed simultaneously, but may be performed separately.

The shape of the suction holes of the dies 81 and 82 used in the joining step and the molding step is not particularly limited. For example, the dies 81 and 82 may have slit-shaped suction grooves.

(embodiment 2)

The plate material of embodiment 2 is used as, for example, a shelf board of a storage box for storing books, shoes, and the like. In embodiment 2, the same reference numerals as those in embodiment 1 are assigned to members having the same configurations as those in embodiment 1, and redundant descriptions are omitted.

As shown in fig. 8, the storage box includes: a storage box 1 having a bottom wall 1a, an upper wall 1b, two side walls 1c, and an inner wall 1 d; and rectangular plate-like deck boards 2. The same point as in embodiment 1 is that the two side walls 1c, 1c have a plurality of sets of support portions 11 arranged so as to face each other.

The deck boards 2 are plate members formed in a polygonal (rectangular in the present embodiment) plate shape. The length of the long side of the deck plate 2 is slightly shorter than the length between the inner surfaces of the opposing side walls 1c, 1c of the storage box 1, and the length of the short side of the deck plate 2 is slightly shorter than the width of the side wall 1 c. The shelf board 2 is mounted to a predetermined position of the storage box 1 by placing both end portions in the longitudinal direction on a set of support portions 11 selected from the plurality of stages of support portions 11. Thereby, the shelf plate 2 defines the internal space of the storage case 1 into a plurality of spaces. Further, the internal space of the storage box 1 can be newly defined by removing the deck boards 2 and placing them on the other group of support portions 11.

As shown in fig. 8, the deck boards 2 have four corners 2 g. The corner portion 2g is a portion where both side edges of the deck board 2 intersect. The entire upper surface 2a of the deck board 2 is smooth. Further, the lower surface 2c of the deck board 2 is smooth except for the four corners 2 g. The four corner portions 2g have reinforcing portions 3 described later. The reinforcing portion 3 has a shape recessed upward from the lower surface 2c of the deck plate 2.

As shown in fig. 9 and 3(a), the deck board 2 includes: the core layer 20 as in embodiment 1; and skin layers 30 and 40 made of thermoplastic resin, which are joined so as to cover the entire core layer 20. The 1 st skin layer 30 is laminated on the 1 st surface (upper surface) of the core layer 20, and the 2 nd skin layer 40 is laminated on the 2 nd surface (lower surface) of the core layer 20. Fig. 9 and 3(a) are perspective views showing a part of a cross section of the deck plate 2 cut at the center in the short direction.

As shown in fig. 9, compressed portions 20a, in which the core layer 20 is compressed and thinned in the thickness direction, are formed in all (four in the present embodiment) side edges of the deck board 2 except for the corner portions 2 g.

As shown in fig. 9, the 2 nd skin layer 40 is folded toward the compressed portion 20a at all side edges of the deck board 2 except for the corner portions 2 g. The 1 st skin layer 30 extends horizontally without being bent at all side edges. The end edge 30a of the 1 st skin layer 30 and the end edge 40a of the 2 nd skin layer 40 abut each other with the compressed portion 20a of the core layer 20 therebetween.

As shown in fig. 9, in the deck board 2 according to embodiment 2, only the 2 nd skin layer 40 is bent upward at all side edges except for the corner portions 2 g. The portion of the 2 nd skin layer 40 from the bent portion to the end edge 40a is formed to cover the end surface 40b of the core layer 20 from the side. The end face 40b of the 2 nd skin layer 40, the compressed portion 20a of the core layer 20, and the end edge 30a of the 1 st skin layer 30 form an end face 2d of the shelf board 2.

As shown in fig. 9, in the end face 2d of the deck board 2, the bent portions of the skin layer 40 are bent. The inclination angle of the end face 40b of the skin layer 40, that is, the inclination angle θ of the end face 40b (end face 2d) to the lower surface 2c of the deck plate 2 is about 70 ° to 90 °.

As shown in fig. 9 and 3(a), the core layer 20 is formed by folding a single sheet of thermoplastic resin molded into a predetermined shape, as in embodiment 1. The structure and manufacturing method of the core layer 20 are the same as those of embodiment 1, and therefore, the description thereof is omitted.

The 1 st skin layer 30 is bonded to the 1 st surface of the core layer 20 via an adhesive layer made of a thermoplastic resin, not shown. Similarly, the 2 nd skin layer 40 is bonded to the 2 nd surface of the core layer 20 by an adhesive layer made of a thermoplastic resin, not shown. The thermoplastic resin constituting the skin layers 30 and 40 may be any conventionally known thermoplastic resin, and may be, for example, a polypropylene resin, a polyamide resin, a polyethylene resin, an acrylonitrile-butadiene-styrene copolymer resin, an acrylic resin, or a polybutylene terephthalate resin. The thermoplastic resin constituting the skin layers 30 and 40 is preferably the same as that of the core layer 20, and the skin layers 30 and 40 of embodiment 2 are made of polypropylene resin. In embodiment 2, the thickness of the 1 st skin layer 30 is about 0.5mm to several mm, as is the thickness of the 2 nd skin layer 40.

As shown in fig. 10, the four corner portions 2g of the deck board 2 include reinforcing portions 3, respectively. Fig. 10, 11, and 13 to 15 show a state in which the shelf board 2 is turned upside down so that the lower surface 2c faces upward and the upper surface 2a faces downward.

As shown in fig. 10 and 11(b), the reinforcing portion 3 includes: a slope 32 extending in a direction obliquely crossing with respect to the upper surface 2a and the lower surface 2 c; and a flat portion 31 located at a front end portion of the corner portion 2g and connected to the inclined surface 32.

As shown in fig. 10, the inclined surface 32 is inclined from the upper surface 2a to the lower surface 2c toward the inside of the deck plate 2 in the corner portion 2g of the deck plate 2. In the corner portion 2g of the deck plate 2, a virtual intersection point 2e is defined between the upper edges of the two intersecting end surfaces 2 d. The bevel 32 has the shape of an isosceles trapezoid having two parallel bases. The short base of the trapezoid is a straight line connecting two points having a length m from the virtual intersection point 2e in a plan view, among two adjacent sides of the upper surface 2 a. The long base of the trapezoid is a straight line connecting two points having a length n from the virtual intersection point 2e in a plan view, among two adjacent sides of the lower surface 2 c. The length m is preferably about 2mm to 30mm, more preferably about 3mm to 15mm, and the length n is preferably about 10mm to 40mm, more preferably about 20mm to 30 mm. The length n is longer than the length m. The inclined surface 32 may be a curved surface curved so as to bulge outward.

The flat portion 31, which intersects the ramp 32, extends substantially horizontally along the upper surface 2a of the deck plate 2. The flat portion 31 is the thinnest portion of the shelf board 2. The end edge 31a of the flat portion 31 has an arc shape bulging outward. The radius of curvature of the end edge 31a is preferably about 5mm to 20mm, and more preferably about 5mm to 10 mm.

When the flat portion 31 and the inclined surface 32 are projected onto the upper surface 2a, the area occupied by the flat portion 31 is smaller than the area occupied by the inclined surface 32. If the lengths m and n for determining the shape of the inclined surface 32 are set to the above ranges and the radius of curvature of the end edge 31a of the flat portion 31 is set to the above ranges, the flat portion 31 can have an appropriate area. The flat portion 31 has the compressed portion 20b between the skin layers 30 and 40, and can effectively suppress peeling of the skin layers 30 and 40 due to an impact on the corner portion 2 g.

A curved surface may be interposed at a boundary portion between the lower surface 2c and the end surface 2d of the deck plate 2 (see fig. 9). Curved surfaces may be interposed between the lower surface 2c and the inclined surface 32, between the inclined surface 32 and the flat portion 31, and between the inclined surface 32 and the end surface 2 d. The curvature of the curved surface of the boundary portion between the lower surface 2c and the inclined surface 32, the boundary portion between the inclined surface 32 and the flat portion 31, and the boundary portion between the inclined surface 32 and the end surface 2d may be made smaller than the curvature of the curved surface of the boundary portion between the lower surface 2c and the side surface. Thus, the impact on the corner portions 2g of the deck boards 2 is easily dispersed.

As shown in fig. 11(b), in the reinforcing portion 3, the compression rate of the core layer 20 is higher toward the top of the corner portion 2 g. The flat portion 31 has a compressed portion 20b at a portion where the thickness of the core layer 20 is thinnest (the compression rate is highest). The compressed portion 20b is formed by press forming in a molding step described later, similarly to the compressed portion 20a of the core layer 20 formed on the side edge other than the reinforcing portion 3 (corner portion 2 g). The compression portion 20b is in the following state: almost all of the thermoplastic resin constituting the core layer 20 melts, and the partition walls 23 described later deform in the cells S forming the core layer 20 to such an extent that the shape thereof cannot be recognized, whereby the 1 st outer wall 21 and the 2 nd outer wall 22 are integrated. The compressed portions 20b of the core layer 20 formed in the reinforcing portion 3 have substantially the same thickness as the compressed portions 20a of the core layer 20 formed at the side edges of the deck boards 2 other than the reinforcing portion 3.

As shown in fig. 11(a) and 11(b), the compressed portions 20b formed in the reinforcing portions 3 may be wider than the compressed portions 20a formed at the side edges of the deck boards 2 other than the reinforcing portions 3. That is, the flat portion 31 projects horizontally with respect to the end surface 2d of the deck plate 2. Here, "wider than the compressed portion 20 a" means that the length of the compressed portion 20b in the direction intersecting the side edges of the deck boards 2 is longer than the length of the compressed portion 20a in the direction intersecting the side edges of the deck boards 2. As described above, each corner portion 2g of the deck board 2 includes the reinforcing portion 3, and the reinforcing portion 3 includes: a flat portion 31 extending along the side edge and having a compression portion 20b wider than the compression portion 20 a; and a slope 32 connected to the flat portion 31.

Next, a method of manufacturing the deck boards 2 will be described with reference to fig. 4 and 12. The method of manufacturing the deck board 2 can be divided into a step of forming the core layer 20, a molding step of obtaining the intermediate body 54 by press-working the core layer 20 and the skin layers 30 and 40, and a post-processing step of obtaining the deck board 2 by finishing the end face shape of the intermediate body 54.

The step of forming the core layer 20 is the same as in embodiment 1.

Next, a molding step of obtaining the intermediate 54 by press-working the core layer 20 and the skin layers 30 and 40 will be described.

First, in order to prepare the core layer 20 used for the deck boards 2, the core layer 20 manufactured in advance is cut into a shape larger than the deck boards 2 as in embodiment 1. In fig. 12, the hollow structure of the core layer 20 is not shown. The skin layers 30 and 40 used in the deck boards 2 are also cut into a shape larger than the deck boards 2, specifically, into a size similar to the core layer 20.

The core layer 20 and the skin layers 30, 40 are heated at predetermined temperatures for predetermined times, respectively. The heating temperature and the heating time can be appropriately set according to the material of the thermoplastic resin constituting the core layer 20 and the skin layers 30 and 40.

As shown in fig. 12(a), the lower die 82 of the press working die has a recessed portion 82a recessed in a substantially rectangular shape. At four corners of the concave portion 82a, portions for forming the reinforcing portions 3 of the deck boards 2 are provided. Further, on four sides of the recess 82a, recesses 82b shallower than the recess 82a are formed. The lower surface of the upper die 81 is a smooth surface.

The heated 2 nd skin layer 40, core layer 20, and 1 st skin layer 30 are arranged in this order from below to form a laminate. The stacked body is placed on the lower die 82 in an aligned state. The core layer 20 and the skin layers 30, 40 are cut into a rectangular shape larger than the deck boards 2. Therefore, in a state where the laminate is placed on the lower die 82, the four sides of the laminate are covered with the outer edges of the concave portions 82 a.

The upper die 81 and the lower die 82 of embodiment 2 are heated to a predetermined temperature. Although the heating temperature can be set as appropriate, in embodiment 2, the heating temperature of the lower mold 82 is made different depending on the location. Specifically, the heating temperature of the peripheral wall of the recess 82a and the heating temperature of the recess 82b are set high, and the heating temperature of the portion other than the peripheral wall of the recess 82a is set low. The heating temperature of the upper die 81 and the lower die 82 is set to be slightly higher than the melting temperature of the thermoplastic resin constituting the core layer 20 and the skin layers 30 and 40 even at any portion.

Next, as shown in fig. 12(b), the upper mold 81 is lowered toward the lower mold 82 to mold the same, and the laminate is pressed. A plurality of suction holes, not shown, are formed in the upper mold 81 and the lower mold 82, and suction is performed through the suction holes when the molds are closed, as in embodiment 1.

As shown in fig. 12(b), the laminate is molded into the inner surface shape of the lower mold 82, that is, the shape of the recesses 82a, 82b, to become the intermediate body 54. The intermediate body 54 has a flat peripheral portion 55 at the side edge.

In the molding step, the heating temperature of the peripheral wall of the recess 82a and the recess 82b forming the peripheral portion 55 of the intermediate body 54 in the lower mold 82 is set high. Therefore, the portions of the peripheral portion 55 and the intermediate body 54 corresponding to the corner portions 2g and the end faces 2d of the deck board 2 are integrated by melting the thermoplastic resin constituting the core layer 20 and the skin layers 30 and 40. Thereby, the compressed portions 20a are formed at the portions corresponding to the end surfaces 2d of the deck boards 2, and the compressed portions 20b are formed at the portions corresponding to the corner portions 2g of the deck boards 2 and the peripheral portions 55 of the intermediate body 54. The thickness of the compressed portions 20a, 20b is thinner than the thickness of the core layer 20 which is not compressed. The compressed portions 20a and 20b are more firmly bonded to the skin layers 30 and 40 than the core layer 20 that is not compressed.

The heating temperature of the lower mold 82 is set to be low except for the four corners and the peripheral wall of the recess 82a, and is set to be slightly higher than the melting temperature of the thermoplastic resin constituting the core layer 20 and the skin layers 30 and 40. Therefore, in the intermediate body 54, the thermoplastic resin constituting the core layer 20 and the skin layers 30 and 40 is melted in portions other than the portions corresponding to the corner portions 2g and the end faces 2d of the deck board 2, and the core layer 20 and the skin layers 30 and 40 are thermally welded.

In the concave portion 82a, the heating temperature at the four corner portions and the peripheral wall is higher than the heating temperature at the other portions. Therefore, as shown in fig. 9, in the core layer 20, the cells S in the first row and the second row of the cell rows arranged in this order from the side edge toward the inside are compressed in the thickness direction. On the other hand, the cells S in the third cell row are not compressed and maintain their original shape.

As shown in fig. 12(c), the intermediate body 54 is taken out from the lower die 82 after the upper die 81 is separated from the lower die 82 and the intermediate body 54 is cooled. The skin layers 30 and 40 are bonded to the 1 st and 2 nd surfaces of the core layer 20, respectively, of the intermediate 54 obtained through the molding step. The intermediate body 54 has a peripheral portion 55 formed over the entire periphery of the side edge having a portion corresponding to the size and shape of the deck board 2.

Next, a post-processing step of the end face shape of the intermediate body 54 will be described.

As shown in fig. 12(d), the peripheral portion 55 formed around the intermediate body 54 is cut. The cutting can be performed by a cutting tool such as a thomson blade, a laser, or the like. By this cutting, side edges of the deck board 2 are formed except for the corner portions 2 g.

As shown in fig. 9 and 11(a), the side edges of the intermediate body 54 have compressed portions 20a of the core layer 20 interposed between the end edge 30a of the skin layer 30 and the end edge 40a of the skin layer 40. Further, at the side edge of the intermediate body 54, the end edge 30a of the skin layer 30, the end face 40b of the skin layer 40, and the compressed portion 20a of the core layer 20 form an end face 2d of the shelf board 2.

As shown in fig. 11(b), the reinforcing portion 3 is formed at the corner portion 2g of the deck board 2, and the reinforcing portion 3 includes a flat portion 31 and a slope 32. The flat portion 31 has a flat plate-like compressed portion 20b wider than the compressed portion 20a between the skin layers 30 and 40.

Then, the cut surfaces of the shelf boards 2 are polished, coated, and the like to finish the shapes of the end surfaces 2d and the reinforcing portions 3. Through the above manufacturing process, the deck board 2 is manufactured.

The operation of the deck board 2 of embodiment 2 will be described.

The deck boards 2 according to embodiment 2 are placed on a pair of support portions 11 formed in the storage box 1, and the internal space of the storage box 1 can be defined into a plurality of spaces. Further, when the deck boards 2 are placed on the support portions 11 of the other groups again, the shape of the internal space of the storage box 1 can be changed.

When the support portion 11 on which the deck board 2 is placed is changed, the deck board 2 may fall, and the corner portion 2g may hit the floor, thereby giving impact of the fall to the corner portion 2 g. In the deck board 2 of embodiment 2, each corner portion 2g includes a reinforcing portion 3, and each reinforcing portion 3 includes: a flat portion 31 having a compressed portion 20b of the core layer 20; and a slope 32 connected to the flat portion 31. The flat portion 31 has a compressed portion 20b wider than a compressed portion 20a formed on the side edge. That is, since the flat portion 31 has a long length in the direction intersecting the side edge, the flat portion can absorb the received impact by performing compression deformation in the longitudinal direction. Further, since the portion of the flat portion 31 constituting the core layer 20, which is dense in the thermoplastic resin, is wide (long in the direction intersecting the side edge), it is difficult to plastically deform even if an impact is applied to the corner portion 2 g. In the flat portion 31, the compressed portion 20b and the skin layers 30 and 40 are firmly joined. Therefore, when an impact is applied to the corner portion 2g, the skin layers 30 and 40 are hardly peeled from the core layer 20. Further, since the flat portion 31 is connected to the inclined surface 32, the impact applied to the corner portion 2g is dispersed from the flat portion 31 to the inclined surface 32. Further, when the inclined surface 32 is formed as a curved surface bulging outward, the impact can be absorbed efficiently.

According to embodiment 2, the following effects can be obtained.

(2-1) the corner portions 2g of the deck boards 2 of embodiment 2 are formed with reinforcing portions 3. The reinforcing portion 3 has a flat portion 31, and the flat portion 31 includes a compressed portion 20b having a width larger than that of the compressed portion 20a of the side edge. In the compression portion 20b, the thermoplastic resin constituting the core layer 20 is melted, cooled, and solidified, and the 1 st outer wall 21, the 2 nd outer wall 22, and the partition walls 23 are integrated into a block shape. Therefore, in the flat portion 31, when an impact is applied to the corner portion 2g of the deck board 2, the compressed portion 20b, which is a dense portion of the thermoplastic resin constituting the core layer 20, can suppress deformation of the corner portion 2 g.

(2-2) in the flat portion 31, the compressed portion 20b and the skin layers 30, 40 are firmly joined. Therefore, even if an impact such as dropping is applied to the corner portions 2g of the deck board 2, the skin layers 30 and 40 can be suppressed from peeling off from the core layer 20 at the corner portions 2 g.

(2-3) the end edge 31a of the flat portion 31 has an arc shape bulging outward. Therefore, even if an impact is applied to the end edge 31a of the flat portion 31, the impact can be effectively dispersed. By dispersing the impact as described above, the peeling between the skin layers 30 and 40 from the compressed portion 20b can be suppressed in the flat portion 31.

(2-4) when the inclined surface 32 of the reinforcing portion 3 is curved, the impact can be effectively absorbed by the elastic deformation of the inclined surface 32. That is, the impact applied to the flat portion 31 is dispersed to the inclined surface 32 connected to the flat portion 31. When the inclined surface 32 is curved, the corner 2g of the deck board 2 is not recessed.

(2-5) the flat portion 31 occupies a smaller area than the inclined surface 32 in the projected area of the reinforcing portion 3 with respect to the upper surface 2 a. In other words, the area of the slope 32 is larger than that of the flat portion 31 having a thinner thickness. Therefore, by dispersing the impact applied to the flat portion 31 to the inclined surface 32, the deformation of the reinforcing portion 3 is suppressed.

(2-6) in the end face 2d of the deck board 2, the compressed portion 20a of the core layer 20 is interposed between the 1 st skin layer 30 and the 2 nd skin layer 40. The compressed portion 20a of the core layer 20 is a block in which the 1 st outer wall 21, the 2 nd outer wall 22, and the partition wall 23 are integrated by melting, cooling, and solidifying the thermoplastic resin constituting the core layer 20. Therefore, the support portion 11 can be stably supported.

(2-7) in the side edges of the shelf plate 2, the cells S in the first row and the second row of cell rows arranged in this order from the side edges toward the inside are compressed in the thickness direction, while the cells S in the third row of cell rows are not compressed. Therefore, the honeycomb structure of the core layer 20 is maintained until the vicinity of the edge, and the strength is maintained.

(2-8) the 1 st skin layer 30 extends horizontally without being bent in the side edges of the deck board 2. Therefore, the area of the upper surface 2a, which is the surface on which the object is placed on the deck boards 2, can be ensured to be large.

(2-9) in the end surface 2d of the deck plate 2, the 2 nd skin layer 40 is bent and curved, and the inclination angle of the end surface 40b of the 2 nd skin layer 40, that is, the inclination angle θ of the end surface 40b (end surface 2d) with respect to the lower surface 2c of the deck plate 2 is about 70 ° to 90 °. Therefore, the support portion 11 of the storage case 1 is stably held.

(2-10) the curvature of the curved surface of the boundary portion between the lower surface 2c and the end surface 2d of the deck plate 2 is larger in the boundary portion between the lower surface 2c and the inclined surface 32, the boundary portion between the inclined surface 32 and the flat portion 31, and the boundary portion between the inclined surface 32 and the end surface 2 d. Therefore, the impact on the corner portions 2g of the deck boards 2 is easily dispersed. On the other hand, since the curvature of the boundary portion between the lower surface 2c and the end surface 2d is small, the shelf plate 2 is stably held on the support portion 11 even when the protruding length of the support portion 11 of the storage box 1 is small.

(2-11) in the step of forming the shelf plate 2, the heating temperature in the lower die 82 is made different depending on the location. Therefore, the deck board 2 can be formed by one-time pressing, and the deck board 2 includes the reinforcing portion 3 having the flat portion 31 and the inclined surface 32, and the end surface 2d having the compressed portion 20 a. This can simplify the molding process of the deck plate 2.

Embodiment 2 may be modified as described below, and these modifications may be appropriately combined and applied.

In embodiment 2, although the description has been given of the case where the plate material is applied to the deck boards 2 of the storage box, the plate material is not limited to the deck boards 2, and can be applied to any plate-like member. For example, a plate material having the same structure as the deck plate 2 of the present embodiment may be applied to a table, a tray, a luggage board for a vehicle, and the like.

The flat portion 31 of the reinforcing portion 3 may not include the compression portion 20 b. In this case, the core layer 20 is removed in the flat portion 31 before the molding step, and the 1 st skin layer 30 and the 2 nd skin layer 40 are joined to each other in the flat portion 31 in the molding step. At this time, the skin layers 30 and 40 are pressed in the molding step, so that the skin layers 30 and 40 are compressed to form the flat portions 31, thereby improving the rigidity of the reinforcing portion 3. In addition, the core layer 20 may not be interposed in the portion of the slope 32.

The deck boards 2 according to embodiment 2 are flat plate members, but are not limited thereto. For example, a curved plate material is also possible.

In the rack board 2 according to embodiment 2, the end edge 31a of the flat portion 31 is arc-shaped, but the configuration is not limited thereto. For example, as shown in fig. 13, when a virtual intersection point 2e is defined between the upper edges of the end surfaces 2d orthogonal to each other in the corner portion 2g of the deck board 2, the flat portion 31 may have a shape (angular shape) in which two end edges 31b, 31b intersecting each other at an obtuse angle are located more inward than the virtual intersection point 2 e.

The flat portion 31 may have a surface provided with a projection or a recess. Further, a protrusion or a recess may be provided on the surface of the inclined surface 32.

The flat portion 31 extends substantially in the horizontal direction along the upper surface 2a of the deck plate 2, but the shape thereof is not limited thereto. For example, the end edges 31a and 31b of the flat portion 31 may be bent upward. At this time, the flat portion 31 becomes the tip portion 31. The flat portion 31 may be inclined with respect to the upper surface 2a of the deck plate 2. In this case, the inclination angle of the flat portion 31 may be smaller than the inclination angle of the inclined surface 32.

The shape of the fixing portion 3 may be changed. For example, the flat portion 31 may have a crescent shape. Alternatively, as shown in fig. 14, the inclined surface 32 may have a triangular shape, and one of corners of the triangular shape may come into contact with the lower surface 2 c. Furthermore, a triangular flat portion 31 may be provided to connect the sides of the remaining two corners of the triangle and overlap one side. In this case, the area occupied by the flat portion 31 may be larger than the area occupied by the inclined surface 32, or may be the same as the area of the reinforcing portion 3 projected on the upper surface 2 a.

The inclined surface 32 of the deck plate 2 of embodiment 2 has an isosceles trapezoid shape. The shape of the inclined surface 32 is not limited to this, and the lengths of the two sides connecting the two ends of the two bottom sides may be different.

Although the reinforcing portion 3 is provided on the lower surface 2c of the deck board 2 according to embodiment 2, the reinforcing portion may be provided on the upper surface 2a, or may be provided on both the upper surface 2a and the lower surface 2 c.

In the side ends of the deck board 2 according to embodiment 2, the 2 nd skin layer 40 is bent, and the 1 st skin layer 30 extends horizontally. The shape of the skin layers 30 and 40 is not limited thereto. For example, the 1 st skin layer 30 may be bent and the 2 nd skin layer 40 may extend horizontally.

As shown in fig. 15(a), the 1 st skin layer 30 may be slightly bent toward the 2 nd skin layer 40, and the 2 nd skin layer 40 bent toward the 1 st skin layer 30 may cover most of the end face of the core layer 20. The end face 2d of the deck board 2 is formed by the end face 40b of the 2 nd skin layer 40, the compressed portion 20a of the core layer 20, and the bent portion 30b of the 1 st skin layer 30, but in this case, the proportion of the 1 st skin layer 30 in the end face 2d of the deck board 2 is smaller than the proportion of the 2 nd skin layer 40.

The shape of the end surface 2d of the deck plate 2 may be changed. As shown in fig. 15(b), the end edge 30a of the skin layer 30 and the end edge 40a of the skin layer 40 extend outward, respectively, and the compressed portion 20a may be interposed between the end edge 30a and the end edge 40a extending outward. At this time, the length of the compression portion 20a in the direction intersecting the side edge is also shorter than that of the compression portion 20 b. The end face 2d having such a shape is obtained by cutting the peripheral portion 55 from the intermediate body 54 in a state where the peripheral portion 55 is slightly left, and is not cut at the innermost side of the peripheral portion 55. At this time, since the joining area between the compressed portion 20a and the skin layers 30 and 40 is increased in the end face 2d, the skin layers 30 and 40 can be prevented from being peeled off from the end face 2 d.

Although the skin layers 30 and 40 of embodiment 2 are formed of a sheet made of a thermoplastic resin, one or both of them may be a nonwoven fabric. For example, when the skin layers 30 and 40 are nonwoven fabrics, an adhesive layer made of a thermoplastic resin (e.g., polypropylene resin) is applied to one surface of the nonwoven fabrics, and the adhesive layer can be bonded to the 1 st surface and the 2 nd surface of the core layer 20. The nonwoven fabric constituting the skin layers 30 and 40 can be formed from various conventionally known fibers such as polypropylene fibers and polyester fibers. When both the skin layers 30 and 40 are nonwoven fabrics, the 1 st skin layer 30 and the 2 nd skin layer 40 may have the same structure or different structures.

The deck board 2 of embodiment 2 may include other layers in addition to the core layer 20 and the skin layers 30 and 40. For example, a decorative layer or a protective layer made of a nonwoven fabric or the like may be laminated on the upper surface of the 1 st skin layer 30 and the lower surface of the 2 nd skin layer 40. In order to increase the strength of the deck board 2, the same steel sheet as in embodiment 1 may be laminated between the core layer 20 and one or both of the skin layers 30 and 40. In the shelf board 2 including the skin layers 30 and 40 as the laminated nonwoven fabric, when the peripheral portion 55 of the intermediate body 54 is cut after the molding step, the end faces of the skin layers 30 and 40 are exposed to the surface. This makes it possible to visually confirm whether or not the skin layers 30 and 40 are joined.

One or both of the upper surface 2a and the lower surface 2c of the deck board 2 may have a recess, a projection, or a hole. In addition, when the recess or the hole is formed, the plate material may be cut. In this case, the end surfaces of the cut recess or hole may be sealed by heat fusion.

Although the shelf board 2 of embodiment 2 has a rectangular plate shape, the shape thereof is not particularly limited. Provided that there is a polygonal shape with corners. In addition, the shape may not be a regular polygonal shape but an irregular polygonal shape.

The core layer 20 may not be a hollow body. For example, the core layer 20 may be formed of a plate material formed of various foams such as a flexible polyurethane foam, a rigid polyurethane foam, a polystyrene foam, a polyethylene foam, a polypropylene foam, an ethylene-vinyl acetate copolymer crosslinked foam, a polyethylene terephthalate resin foam, a phenol foam, and a silicone foam.

In embodiment 2, the heating temperatures of the molds 81 and 82 are adjusted to be different depending on the location in the molding step. Instead of this, or in addition to this, the heating temperatures of the core layer 20 and the skin layers 30 and 40, that is, the heating temperatures of the core layer 20 and the skin layers 30 and 40 placed before the dies 81 and 82 may be adjusted to be different depending on the portions. At this time, in order to adjust the heating temperature, a shielding member such as a punching metal, a wire mesh, or a steel plate is appropriately provided on the surface of the core layer 20 to block heat. The heating temperature can be adjusted by changing the size, number, or the like of the holes formed in the shielding member.

The following modifications of the 1 st and 2 nd embodiments are possible, and these modifications may be appropriately combined and applied.

The printed resin films may be used as the skin layers 30, 40, 50, and 60. This enables the deck boards 2 to be decorated.

The core layer 20 is not limited to one sheet 1 of the first sheet 100 that is formed by fold forming. For example, a plurality of strip-shaped sheets may be arranged by being bent at predetermined intervals to form the side walls of the cell, and sheet layers may be arranged on the upper and lower surfaces of the strip-shaped sheets to form the upper and lower walls of the cell, respectively.

In embodiments 1 and 2, the cells S having a hexagonal columnar shape are defined and formed inside the core layer 20, but the shape of the cells S is not particularly limited thereto. For example, the cells S may have a polygonal shape such as a quadrangular prism shape or an octagonal prism shape, or may have a cylindrical shape. As another example, the shape of the cell S may be a truncated cone whose diameter decreases toward the projection surface. Further, the cells S having different shapes may be mixed in the core layer 20. Further, the cells may not be adjacent to each other, and a gap (space) may be provided between the cell S and the cell S.

The core layer 20 is not limited to a layer defining the pillar-shaped cells S. For example, the core layer 20 may be formed by joining sheet layers to both surfaces of a sheet main body having a predetermined uneven shape. Examples of the core layer having the above-described structure include the core layer described in japanese patent application laid-open publication No. 2014-205341. As another example, a plastic cardboard having a harmonica-shaped cross section, in which a thin sheet layer is joined to each of both surfaces of a corrugated plate that is bent or folded in a wave shape, may be used as the core layer 20.

In embodiment 1 and embodiment 2, the core layer 20 as a honeycomb structure in which hexagonal cells S are formed inside the core layer 20 is formed by fold-molding one sheet of the 1 st sheet 100, but the molding method is not limited to this. For example, as described in japanese patent No. 4368399, the core layer 20 as a honeycomb structure may be formed by sequentially folding a three-dimensional structure in which a plurality of trapezoidal cross-sectional protrusions are arranged.

The skin layers 30, 40, 50, and 60 are not limited to a single-layer structure, and may be a multilayer structure.

As the thermoplastic resin constituting the core layer 20 and the skin layers 30, 40, 50, and 60, resins to which various functional resins are added may be used. For example, flame retardancy can be improved by adding a flame retardant resin to a thermoplastic resin. The core layer 20 and the skin layers 30, 40, 50, and 60 may all be formed of a thermoplastic resin to which a functional resin is added, or at least one of the core layer 20 and the skin layers 30, 40, 50, and 60 may be formed of a thermoplastic resin to which a functional resin is added.