초록 ▼

A sheet material (1) includes a stiffness-increasing concave-convex part (20). A first reference plane (K1), an intermediate reference plane (K3), and a second reference plane (K2) serve as a reference system. First unit areas (241) and second unit areas (242) are defined in the intermediate referen

A sheet material (1) includes a stiffness-increasing concave-convex part (20). A first reference plane (K1), an intermediate reference plane (K3), and a second reference plane (K2) serve as a reference system. First unit areas (241) and second unit areas (242) are defined in the intermediate reference plane (K3). Each of the first unit areas (241) and the second unit areas (242) contains first virtual squares (243) and second virtual squares (244). Icosagonal areas that contain only adjacent first virtual squares (243) are designated as first reference areas (213), and icosagonal areas that contain only adjacent second virtual squares (244) are designated as second reference areas (223). The concave-convex part (20) contains first areas (21), which are formed based on the first reference areas (213), as well as second areas (22) and/or plane areas (23), which are formed based on the second reference areas (223).

대표청구항 ▼

1. A sheet material having a stiffness-increasing concave-convex part, wherein a first reference plane, an intermediate reference plane, and a second reference plane, which are three virtual planes that are successively disposed spaced apart and parallel to one another, serve as a reference system;f

1. A sheet material having a stiffness-increasing concave-convex part, wherein a first reference plane, an intermediate reference plane, and a second reference plane, which are three virtual planes that are successively disposed spaced apart and parallel to one another, serve as a reference system;first unit areas and second unit areas are virtual rectangles of the same size, and extend in a grid in the intermediate reference plane;directions parallel to one side of each of the virtual rectangles are defined as X directions, and directions perpendicular to the X directions are defined as Y directions;in each of the first unit areas and the second unit areas, the virtual rectangles are respectively partitioned by a virtual lattice such that a side extending in the X directions is divided into three equal parts and a side extending in the Y directions is divided into five equal parts, wherein fifteen virtual squares are defined within the virtual lattice;the virtual square at any arbitrary one corner of the first unit areas and the second unit areas is designated as a reference square, a row that comprises virtual squares disposed in the X directions and that includes the reference square is designated a first row, successively adjacent rows are designated as second through fifth rows, a row that comprises virtual squares disposed in the Y directions and that includes the reference square is designated as a row A, andsuccessively adjacent rows are designated as rows B and C;in each of the first unit areas, all the virtual squares disposed in the first row and the fifth row are first virtual squares, and, in the second row through the fourth row, the virtual squares disposed in the row A and the row C are second squares and the virtual squares disposed in the row B are first virtual squares;in each of the second unit areas, all the virtual squares disposed in the first row and the fifth row are second virtual squares, and, in the second row through the fourth row, the virtual squares disposed in the row A and the row C are first virtual squares and the virtual squares disposed in the row B are second virtual squares;in the intermediate reference plane, the first unit areas and the second unit areas are disposed with the same orientation, and, in the Y directions, a plurality of unit area rows, wherein the first unit areas and the second unit areas are alternately disposed in one row, is formed;the unit area rows that are adjacent in the X directions in the intermediate reference plane are disposed at positions shifted from one another by three virtual squares in the Y directions;in the intermediate reference plane, a first icosagonal area that comprises the first virtual squares that share adjacent sides is designated as a first reference area, and a second icosagonal area that comprises the second virtual squares that share adjacent sides is designated as a second reference area;the concave-convex part is provided with first areas, which protrude from the first reference areas defined in the intermediate reference plane toward the first reference plane, and is provided with either or both of (i) second areas, which protrude from the second reference areas defined in the intermediate reference plane toward the first reference plane or the second reference plane, and (ii) plane areas, which are formed based on the second reference areas in the intermediate reference plane;each of the first areas comprises a first top surface, which is a projection of the first reference area into the first reference plane and has an area equal to or less than the first reference area, and first side surfaces, which connect an outer periphery of that first top surface with an outer periphery of its first reference area; andeach of the second areas comprises a second top surface, which is a projection of the second reference area into the first reference plane or the second reference plane and has an area equal to or less than the first reference area, and second side surfaces, which connect an outer periphery of that second top surface with an outer periphery of its second reference area. 2. The sheet material according to claim 1, wherein a first inclination angle θ1 (°) of the first side surface with respect to the second reference plane is within the range of 10°-90°; anda second inclination angle θ2 (°) of the second side surface with respect to the second reference plane is within the range of 10°-90°. 3. The sheet material according to claim 1, wherein at least a part of the sheet material is curved. 4. The sheet material according to claim 1, wherein the concave-convex part is formed by press forming or roll forming a metal sheet. 5. The sheet material according to claim 4, wherein the metal sheet prior to the press forming or the roll forming has a sheet thickness t (mm) of 0.03-6.0 mm. 6. The sheet material according to claim 5, wherein a ratio L/t of the length L (mm) of one side of each virtual square to the sheet thickness t (mm) is 10-2000. 7. The sheet material according to claim 5, wherein a ratio H1/t of a projection height H1 (mm) of the first area to the sheet thickness t (mm), and a maximum inclination angle θ1 (°) formed between each first side surface and the intermediate reference plane satisfy the relationship 1≦(H1/t)≦−3θ1+272; anda ratio H2/t of a projection height H2 (mm) of the second area to the sheet thickness t (mm), and a maximum inclination angle θ2 (°) formed between each second side surface and the intermediate reference plane satisfy the relationship 1≦(H2/t)≦3θ2+272. 8. The sheet material according to claim 7, wherein the first maximum inclination angle θ1 (°) of the first side surface with respect to the second reference plane is within the range of 10°-70°; andthe second maximum inclination angle θ2 (°) of the second side surface with respect to the second reference plane is within the range of 10°-70°. 9. The sheet material according to claim 8, wherein the first and second maximum inclination angles are each 30°. 10. The sheet material according to claim 8, wherein a ratio L/t of the length L (mm) of one side of each virtual square to the sheet thickness t (mm) is 10-2000. 11. A sheet material having a stiffness-increasing concave-convex part, wherein a first reference plane, an intermediate reference plane, and a second reference plane, which are three virtual planes that are successively disposed spaced apart and parallel to one another, serve as a reference system;first unit areas and second unit areas are virtual rectangles of the same size, and extend in a grid in the intermediate reference plane;directions parallel to one side of each of the virtual rectangles are defined as X directions, and directions perpendicular to the X directions are defined as Y directions;in each of the first unit areas and the second unit areas, the virtual rectangles are respectively partitioned by a virtual lattice such that a side extending in the X directions is divided into three equal parts and a side extending in the Y directions is divided into five equal parts, wherein fifteen virtual boxes are defined within the virtual lattice;the virtual box at any arbitrary one corner of the first unit areas and the second unit areas is designated as a reference box, a row that comprises virtual boxes disposed in the X directions and that includes the reference box is designated a first row, successively adjacent rows are designated as second through fifth rows, a row that comprises virtual boxes disposed in the Y directions and that includes the reference box is designated as a row A, and successively adjacent rows are designated as rows B and C;in each of the first unit areas, all the virtual boxes disposed in the first row and the fifth row are first virtual boxes, and, in the second row through the fourth row, the virtual boxes disposed in the row A and the row C are second boxes and the virtual boxes disposed in the row B are first virtual boxes;in each of the second unit areas, all the virtual boxes disposed in the first row and the fifth row are second virtual boxes, and, in the second row through the fourth row, the virtual boxes disposed in the row A and the row C are first virtual boxes and the virtual boxes disposed in the row B are second virtual boxes;in the intermediate reference plane, the first unit areas and the second unit areas are disposed with the same orientation, and, in the Y directions, a plurality of unit area rows, wherein the first unit areas and the second unit areas are alternately disposed in one row, is formed;the unit area rows that are adjacent in the X directions in the intermediate reference plane are disposed at positions shifted from one another by three virtual boxes in the Y directions;in the intermediate reference plane, a first icosagonal area that comprises the first virtual boxes that share adjacent sides is designated as a first reference area, and a second icosagonal area that comprises the second virtual boxes that share adjacent sides is designated as a second reference area;the concave-convex part is provided with first areas, which protrude from the first reference areas defined in the intermediate reference plane toward the first reference plane, and is provided with either or both of (i) second areas, which protrude from the second reference areas defined in the intermediate reference plane toward the first reference plane or the second reference plane, and (ii) plane areas, which are formed based on the second reference areas in the intermediate reference plane;each of the first areas comprises a first top surface, which is a projection of the first reference area into the first reference plane and has an area equal to or less than the first reference area, and first side surfaces, which connect an outer periphery of that first top surface with an outer periphery of its first reference area; andeach of the second areas comprises a second top surface, which is a projection of the second reference area into the first reference plane or the second reference plane and has an area equal to or less than the first reference area, and second side surfaces, which connect an outer periphery of that second top surface with an outer periphery of its second reference area,wherein the virtual boxes that comprise the first and second icosagonal area have a length L (mm) of one side of each virtual box and a length M (mm) of a side that is orthogonal to the one side that satisfy the relationship 0.5 L≦M≦2 L. 12. The sheet material according to claim 11, wherein a first inclination angle θ1 (°) of the first side surface with respect to the second reference plane is within the range of 10°-90°; anda second inclination angle θ2 (°) of the second side surface with respect to the second reference plane is within the range of 10°-90°. 13. The sheet material according to claim 11, wherein at least a part of the sheet material is curved. 14. The sheet material according to claim 11, wherein the concave-convex part is formed by press forming or roll forming a metal sheet. 15. The sheet material according to claim 14, wherein the metal sheet prior to the press forming or the roll forming has a sheet thickness t (mm) of 0.03-6.0 mm. 16. The sheet material according to claim 15, wherein a ratio L/t of the length L (mm) of one side of each virtual box to the sheet thickness t (mm) is 10-2000. 17. The sheet material according to claim 15, wherein a ratio H1/t of a protrusion height H1(mm) of the first area to the sheet thickness t (mm), and a maximum inclination angle θ1 (°) formed between each first side surface and the intermediate reference plane satisfy the relationship 1≦(H1/t)≦−3θ1+272; anda ratio H2/t of a protrusion height H2 (mm) of the second area to the sheet thickness t (mm) and a maximum inclination angle θ2 (°) formed between each second side surface and the intermediate reference plane satisfy the relationship 1≦(H2/t)≦−3θ+272. 18. The sheet material according to claim 17, wherein the first maximum inclination angle θ1 (°) of the first side surface with respect to the second reference plane is within the range of 10°-70°; andthe second maximum inclination angle θ2 (°) of the second side surface with respect to the second reference plane is within the range of 10°-70°. 19. The sheet material according to claim 18, wherein the first and second maximum inclination angles are each 30°. 20. The sheet material according to claim 18, wherein a ratio L/t of the length L (mm) of one side of each virtual box to the sheet thickness t (mm) is 10-2000.