Structure and method for manufacturing same
A structure with jointed elastic members and a lower-density reinforcing member addresses buckling issues by generating compressive and tensile stresses, maintaining stability and weight efficiency.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- NATURE ARCHITECTS INC
- Filing Date
- 2025-12-15
- Publication Date
- 2026-06-25
AI Technical Summary
Existing structures face buckling issues during bending deformation, which can be mitigated by increasing the thickness of the second elastic member, but this approach leads to a significant increase in weight.
A structure comprising a first elastic member and a second elastic member with joints, joined to a reinforcing member of lower mass density, generates compressive and tensile stresses to suppress buckling while maintaining a reduced overall weight.
The solution effectively suppresses buckling during bending deformation without increasing the structure's weight, ensuring stable deformation and consistent reaction forces.
Smart Images
Figure JP2025043765_25062026_PF_FP_ABST
Abstract
Description
Structure and method for manufacturing the same
[0001] The present disclosure relates to a structure and a method for manufacturing the same.
[0002] Conventionally, a structure has been proposed that includes a first elastic member extending linearly along a predetermined direction, and a second elastic member having both ends in the predetermined direction joined to the first elastic member and at least a part of an intermediate portion, which is a portion between both ends in the predetermined direction, being convex in a direction away from the first elastic member (see Patent Document 1). When a pressing force in a direction approaching the first elastic member is applied to the intermediate portion of the second elastic member in this structure, a compressive stress in the predetermined direction is generated in the second elastic member and a tensile stress in the predetermined direction is generated in the first elastic member along with bending deformation of the intermediate portion.
[0003] Japanese Patent Application Laid-Open No. 2024-74218
[0004] In the above-described structure, buckling (so-called Euler buckling) may occur during bending deformation of the second elastic member. Although it is conceivable to increase the thickness of the second elastic member to suppress this, in this case, there is a possibility of a relatively large increase in the weight of the entire structure.
[0005] The main object of the present disclosure is to suppress buckling during deformation of the structure while suppressing an increase in the weight of the entire structure.
[0006] The present disclosure has adopted the following means to achieve the above main object.
[0007] The structure of the present disclosure comprises: a first elastic member extending linearly along a predetermined direction; and a second elastic member extending curvedly along the predetermined direction and having a plurality of joints joined to the first elastic member at intervals along the predetermined direction, wherein the structure comprises a reinforcing member formed of a material with a lower mass density than the second elastic member and joined to the first or second surface of the second elastic member, wherein when a pressing force is applied to a non-joint portion of the second elastic member, which is the portion between two adjacent joints of the second elastic member, and a non-joint corresponding portion of the reinforcing member, which is the portion corresponding to the non-joint portion, the structure generates compressive stress in the predetermined direction in the second elastic member and the reinforcing member, and generates tensile stress in the predetermined direction in the first elastic member, accompanied by bending deformation of the non-joint portion and the non-joint corresponding portion.
[0008] The structure of this disclosure increases the total thickness of the second elastic member by joining a reinforcing member to the second elastic member. This suppresses buckling during bending deformation of the second elastic member and the reinforcing member while suppressing an increase in the overall weight of the structure compared to when the thickness of the second elastic member is increased.
[0009] A method for manufacturing a structure according to the present disclosure, comprising: a step (A) of placing a second elastic member, which extends in a curved manner along a predetermined direction, on top of a first elastic member, which extends linearly along a predetermined direction; a step (B) of joining the second elastic member to the first elastic member at a plurality of joints spaced apart along the predetermined direction, after step (A); and a step (C) of joining a reinforcing member, which is made of a material with a lower mass density than the second elastic member, to a first or second surface of the second elastic member, after step (B) or before step (A), wherein when a pressing force is applied to a non-joint portion, which is the portion of the second elastic member between two adjacent joints, and a non-joint corresponding portion, which is the portion of the reinforcing member corresponding to the non-joint portion, in a direction that brings the structure closer to the first elastic member, compressive stress in the predetermined direction is generated in the second elastic member and the reinforcing member, accompanied by bending deformation of the non-joint portion and the non-joint corresponding portion, and tensile stress in the predetermined direction is generated in the first elastic member. This is the gist of it.
[0010] The method for manufacturing the structure of the present disclosure includes the three steps described above to manufacture the structure. By joining a reinforcing member to a second elastic member and increasing the total thickness of these members, it is possible to suppress buckling during bending deformation of the second elastic member and the reinforcing member while suppressing an increase in the overall weight of the structure compared to when the thickness of the second elastic member is increased.
[0011] This is an external perspective view of the structure of the embodiment. This is a front view of the structure of the embodiment. This is a process diagram showing the manufacturing process of the structure. This is an explanatory diagram showing the deformation of the structure of the embodiment. This is an explanatory diagram showing the deformation of the structure of the comparative example. This is an explanatory diagram showing the relationship between displacement and reaction force of the structures of the embodiment and the comparative example. This is an external perspective view of the structure of the first modified example. This is a front second modified example. This is an external perspective view of the structure of the third modified example. This is a front view of the structure of the third modified example.
[0012] Embodiments for implementing this disclosure will be described with reference to the drawings. Figure 1 is an external perspective view of the structure 20 of the embodiment, and Figure 2 is a front view of the structure 20. The front-to-back, left-to-right, and up-to-down directions of the structure 20 are as shown in Figures 1 and 2.
[0013] As shown in Figures 1 and 2, the structure 20 of the embodiment comprises a first elastic member 30, a second elastic member 40, and a reinforcing member 50. The first elastic member 30 is a rectangular flat plate extending in the front-rear direction and the left-right direction. The second elastic member 40 extends in a corrugated shape along the left-right direction and straight along the front-rear direction. This second elastic member 40 is joined to the first elastic member 30 at multiple points spaced apart in the left-right direction. In the second elastic member 40, the wave shape may be, for example, a shape that combines multiple circular arcs, or a sine wave shape. Furthermore, if the second elastic member 40 has a wave shape with multiple periods, the distance of each period in the left-right direction is preferably constant, but may be different.
[0014] The first and second elastic members 30 and 40 each have n (n≧3) joints 31 and 41 that are joined to each other at intervals in the left-right direction, and n-1 non-joints 36 and 46 that are between two adjacent joints 31 and 41. Here, the eight joints 31 and 41 have, in order from left to right in Figures 1 and 2, left-end joints 32 and 42, n-2 intermediate joints 34 and 44, and right-end joints 33 and 43. Figures 1 and 2 show the case where n is 8, but are not limited to this. Each intermediate joint 34 and each intermediate joint 44 are joined by welding, bonding, riveting, etc. The left-end joint 32 and the left-end joint 42 are joined by crimping. The joining of the left-end joint 32 and the left-end joint 42 forms a crimped section 22. The right end joint 33 and the right end joint 43 are joined by crimping. The joining of the right end joint 33 and the right end joint 43 forms a crimped section 24. The two crimped sections 22 and 24 are formed when the first and second elastic members 30 and 40 are stacked and at least one end of the first and second elastic members 30 and 40 is folded back at least twice towards the second elastic member 40. In the example in Figure 2, the two crimped sections 22 and 24 are formed when the first and second elastic members 30 and 40 are stacked and only the first elastic member 30 is folded back once, and then the first and second elastic members 30 and 40 are folded back together once. Of course, the folding method and number of folds for the two crimped sections 22 and 24 are not limited to these. Generally, the mechanical strength due to the structure of the crimped sections 22 and 24 is higher than the mechanical strength due to welding or bonding. As will be described later, when a pressing force is applied to the structure 20 from above and below, a shear force is generated between the first and second elastic members 30 and 40. However, the crimping portions 22 and 24 make it possible to maintain the joint at both ends of the first and second elastic members 30 and 40.
[0015] The reinforcing member 50 is formed in a corrugated shape similar to that of the second elastic member 40, and is joined by adhesive or the like to the portion of the second elastic member 40 opposite to the first elastic member 30 (the upper surface in Figures 1 and 2), excluding the left end joint portion 42 and the right end joint portion 43. Hereinafter, the portion of the reinforcing member 50 corresponding to the unjointed portion 46 of the second elastic member 40 will be referred to as the unjointed portion 56. The reinforcing member 50 is formed from a material with a lower mass density than that of the second elastic member 40. Preferably, the thickness of the reinforcing member 50 is the same as or greater than the thickness of the second elastic member 40. More preferably, the thickness of the reinforcing member 50 is about 2 to 10 times the thickness of the second elastic member 40. Preferably, the rigidity of the reinforcing member 50 is about 1 / 100 to 1 / 10 of the rigidity of the second elastic member 40.
[0016] Several examples of material combinations for the first and second elastic members 30, 40 and the reinforcing member 50 are listed below. For example, the first and second elastic members 30, 40 may be made of iron or titanium, and the reinforcing member 50 may be made of either resin or aluminum. The first and second elastic members 30, 40 may be made of fiber-reinforced resin, and the reinforcing member 50 may be made of resin or rubber. The first and second elastic members 30, 40 may be made of resin, and the reinforcing member 50 may be made of rubber. The first and second elastic members 30, 40 may be made of the same material or of different materials.
[0017] The structure 20 of the embodiment is manufactured, for example, by the manufacturing method shown in Figure 3. As shown in Figure 3, the first and second elastic members 30 and 40 are stacked in this order from the bottom (step S100), and the first and second elastic members 30 and 40 are joined together by n joints 31 and 41 (step S110). Subsequently, the reinforcing member 50 is joined to the upper surface of the second elastic member 40 (step S120) to complete the structure 10. Note that step S120 may be performed before step S100.
[0018] In step S110, a crimped portion 22 is formed by joining the left end joint 32 and the left end joint 42, and a crimped portion 24 is formed by joining the right end joint 33 and the right end joint 43. Specifically, the crimped portion 22 is formed by folding the first and second elastic members 30 and 40 together towards the second elastic member 40 while they are stacked, and the crimped portion 24 is formed in the same manner. More specifically, the crimped portion 22 is formed by folding only the first elastic member 30 once while the first and second elastic members 30 and 40 are stacked, and then folding the first and second elastic members 30 and 40 together once, and the crimped portion 24 is formed in the same manner.
[0019] Figure 4 is an explanatory diagram showing the deformation of the structure 20 when flat plates are placed on the upper and lower sides of the structure 20 of the embodiment and a pressing force Fe is applied to the structure 20 so as to sandwich it from above and below. Figure 5 is an explanatory diagram showing the deformation of the structure 920 when flat plates are placed on the upper and lower sides of the structure 920 of the comparative example and a pressing force Fc is applied to the structure 920 so as to sandwich it from above and below. The structure 920 corresponds to the structure 20 with the reinforcing member 50 removed. Therefore, the total thickness of the second elastic member 40 and the reinforcing member 50 of the structure 20 is greater than the thickness of the second elastic member 40 of the structure 920. Figure 4(A) shows the structure 20 with flat plates placed on the upper and lower sides. Figures 4(B) to 4(E) show the structure 20 gradually deforming due to the pressing force Fe. Figure 5(A) shows the structure 920 with flat plates placed on the upper and lower sides. Figures 5(B) to 5(E) show how the structure 920 gradually deforms due to the pressing force Fc.
[0020] As shown in Figure 5, in the structure 920, the pressing force Fc from the vertical direction causes the non-joint portion 46 of the second elastic member 40 to gradually bend and deform so that it approaches the non-joint portion 36 of the first elastic member 30. At this time, the pressing force Fc is converted into a left-right force on the second elastic member 40 (a force that separates the two adjacent joint portions 41) and transmitted to the first elastic member 30 via the joint portions 41, 31 as a left-right tensile force (a force that separates the two adjacent joint portions 31). Consequently, a left-right compressive stress σ2c (a stress that brings the two adjacent joint portions 41 closer together) is generated inside the second elastic member 40, and a tensile stress σ1c (a force that separates the two adjacent joint portions 31) is generated inside the first elastic member 30. The structure 920 generates a reaction force Rc to the pressing force Fc due to the compressive stress σ2c inside the second elastic member 40 and the tensile stress σ1c inside the first elastic member 30.
[0021] As shown in Figure 4, in the structure 20, the pressing force Fe from the vertical direction causes the non-joint portion 46 of the second elastic member 40 and the non-joint corresponding portion 56 of the reinforcing member 50 to gradually bend and deform so that they approach the non-joint portion 36 of the first elastic member 30. At this time, the pressing force Fe is converted into a left-right force on the second elastic member 40 and the reinforcing member 50 and transmitted to the first elastic member 30 as a left-right tensile force via the joints 41 and 31. Consequently, a left-right compressive stress σ2e is generated inside the second elastic member 40 and the reinforcing member 50, and a tensile stress σ1e is generated inside the first elastic member 30. The structure 20 generates a reaction force Re to the pressing force Fe due to the compressive stress σ2e inside the second elastic member 40 and the reinforcing member 50 and the tensile stress σ1e inside the first elastic member 30. In this embodiment, the height (vertical length) of the crimping of the left end joints 32, 42 and the right end joints 33, 43 of the first and second elastic members 30, 40 is adjusted to be lower than the height of the structure 20 when the second elastic member 40 and the reinforcing member 50 are flattened, that is, when the structure 20 is completely crushed (see Figure 4(E)). This prevents the left end joints 32, 42 and the right end joints 33, 43 from hindering the complete crushing of the structure 20.
[0022] As shown in Figure 5, in structure 920, buckling (so-called Euler buckling) occurs in the non-joint portion 46 as it approaches the non-joint portion 36 (see Figure 5(D)). In contrast, in structure 20, buckling of the non-joint portion 46 and the non-joint corresponding portion 56 is suppressed as they approach the non-joint portion 36. This is thought to be due to the following reason: In structure 920, when the non-joint portion 46 approaches the non-joint portion 36, a force acts on the non-joint portion 46 in its extending direction, but because the thickness of the second elastic member 40 is thin, buckling occurs in the non-joint portion 46. On the other hand, in structure 20, when the non-joint portion 46 and the non-joint corresponding portion 56 approach the non-joint portion 36, forces act on the non-joint portion 46 and the non-joint corresponding portion 56 in their extending direction. However, because the total thickness of the second elastic member 40 and the reinforcing member 50 is thick, it is thought that buckling of the non-joint portion 46 and the non-joint corresponding portion 56 is suppressed. It is also conceivable to make the thickness of the second elastic member 40 of structure 920 about the same as the total thickness of the second elastic member 40 and the reinforcing member 50 of structure 20, but in this case, it may lead to a relatively large increase in the overall weight of structure 920. From the above, it can be said that by joining the second elastic member 40 and the reinforcing member 50 and increasing their total thickness, structure 20 can suppress buckling during bending deformation of the second elastic member 40 and the reinforcing member 50 while suppressing an increase in the overall weight of structure 20 compared to increasing the thickness of the second elastic member 40 alone.
[0023] Figure 6 is an explanatory diagram showing the relationship between displacement and reaction force when the structures 20 and 920 of the embodiment and comparative example deform as shown in Figures 4 and 5. The relationship in Figure 6 was obtained by analysis by the inventors.
[0024] As shown in the figure, the reaction force of the structure 920 changes in the order of gradual increase, sharp decrease, gradual increase, gradual decrease, and sharp increase as the displacement increases. Specifically, the reaction force of the structure 920 gradually increases with increasing displacement in the region of 0 to 0.5 mm and the region of 0.5 mm to 0.7 mm (it has positive stiffness), but the reaction force sharply decreases with increasing displacement around 0.5 mm, and the reaction force gradually decreases with increasing displacement in the region of 0.7 mm to 0.9 mm. These sharp and gradual decreases in the reaction force with increasing displacement are thought to be due to buckling of the non-joint portion 46 of the second elastic member 40. In addition, the reaction force of the structure 920 sharply increases with increasing displacement around 0.9 mm (near the maximum value).
[0025] In contrast, the reaction force of the structure 20 changes in the order of gradually increasing, approximately constant, and rapidly increasing with increasing displacement. Specifically, the reaction force of the structure 20 gradually increases with increasing displacement in the region where the displacement is around 0 mm to 0.6 mm (having positive stiffness), and is approximately constant in the region where the displacement is around 0.6 mm to 0.8 mm (having approximately zero stiffness). Furthermore, the reaction force of the structure 20 rapidly increases with increasing displacement in the region where the displacement is around 0.8 mm to 0.9 mm (near the maximum value). Therefore, it is considered that the structure 20 can secure a displacement region with approximately zero stiffness by suppressing buckling of the non-jointed portion 46 of the second elastic member 40 and the non-jointed corresponding portion 56 of the reinforcing member 50, and can also suppress the rapid decrease or gradual decrease of the reaction force with increasing displacement.
[0026] As described above, in the structure 20 of the embodiment, the first and second elastic members 30 and 40 are joined to each other by n (n≧3) joints 31 and 41 spaced apart in a predetermined direction (left and right direction in Figures 1 and 2), and a reinforcing member 50 made of a material with a lower mass density than the second elastic member 40 is joined to the side of the second elastic member 40 opposite to the first elastic member 30. By joining the second elastic member 40 and the reinforcing member 50 in this way and increasing their total thickness, it is possible to suppress buckling during bending deformation of the second elastic member 40 and the reinforcing member 50 while suppressing an increase in the overall weight of the structure 20 compared to increasing the thickness of the second elastic member 40 alone.
[0027] In the embodiments described above, the second elastic member 40 in the structure 20 is configured to extend in a wave shape along a predetermined direction (the left-right direction in Figures 1 and 2), but it is not limited to this, and it is acceptable for it to extend in a curved shape along a predetermined direction. Here, "extending in a curved shape" means that the entire structure may extend in a curved shape, or it may extend including both a curved portion and a straight portion.
[0028] In the embodiment described above, the left end joints 32 and 42 of the first and second elastic members 30 and 40 in the structure 20 are joined by crimping, but the embodiment is not limited to this. For example, the left end joints 32 and 42 may be joined by crimping other than crimping, or by welding, bonding, riveting, etc. The joining method for the right end joints 33 and 43 is the same.
[0029] In the structure 20 of the above-described embodiment, the first and second elastic members 30 and 40 each have n (n≧3) joints 31 and 41 and n-1 non-joints 36 and 46, and the n joints 31 and 41 each have left-end joints 32 and 42, n-2 intermediate joints 34 and 44, and right-end joints 33 and 43. However, n may be 2. That is, the first and second elastic members 30 and 40 may have two joints 31 and 41 consisting of left-end joints 32 and 42 and right-end joints 33 and 43, and one non-joint, 46, and may not have intermediate joints 34 and 44.
[0030] In the structure 20 of the embodiment described above, the reinforcing member 50 is joined to the side of the second elastic member 40 opposite to the first elastic member 30. Alternatively, the reinforcing member may be joined to the side of the second elastic member 40 that is on the side of the first elastic member 30. In this case, the multiple joints 31, 41 of the first and second elastic members 30, 40 are joined to each other via the reinforcing member 50.
[0031] In the embodiments described above, the structure 20 was explained, but the invention is not limited thereto. Figure 7 is an external perspective view of the first modified structure 120, and Figure 8 is a front view of the structure 120. Figure 9 is a front view of the second modified structure 220. Figure 10 is an external perspective view of the third modified structure 320. Figure 11 is a front view of the structure 320. Hereinafter, the structures 120, 220, and 320 will be described in that order.
[0032] As shown in Figures 7 and 8, the first modified structure 120 comprises a structure 20A identical to the structure 20 shown in Figures 1 and 2, and a structure 20B which is the same as structure 20 but inverted vertically. The lower surface of the first elastic member 30 of structure 20A and the upper surface of the first elastic member 30 of structure 20B are joined to each other. In structure 120, as in structure 20, by joining the second elastic member 40 and the reinforcing member 50 to increase their total thickness, it is possible to suppress buckling during bending deformation of the second elastic member 40 and the reinforcing member 50 while suppressing an increase in the overall weight of structure 120 compared to when the thickness of the second elastic member 40 is increased.
[0033] As shown in Figure 9, the second modified structure 220, like structure 120, comprises structures 20A and 20B, with the first elastic member 30 being shared between structures 20A and 20B. In structure 220, as with structure 20, the second elastic member 40 and the reinforcing member 50 are joined together to increase their total thickness. This suppresses buckling during bending deformation of the second elastic member 40 and the reinforcing member 50 while reducing the overall weight increase of structure 220 compared to the case where the thickness of the second elastic member 40 is increased. Furthermore, structure 220 can be made shorter in height (vertical length) compared to structure 120.
[0034] As shown in Figures 10 and 11, the third modified structure 320, like structure 120, comprises structures 20A and 20B, with the reinforcing member 50 being shared between structures 20A and 20B. In structure 320, as with structure 20, by joining the second elastic member 40 and the reinforcing member 50 to increase their total thickness, it is possible to suppress buckling during bending deformation of the second elastic member 40 and the reinforcing member 50 while suppressing an increase in the overall weight of structure 320 compared to the case where the thickness of the second elastic member 40 is increased. In addition, the height (vertical length) of structure 320 can be shortened compared to the case where the reinforcing member 50 is not shared between structures 20A and 20B.
[0035] The correspondence between the main elements of the embodiment and the main elements of the disclosure described in the section on the main elements of the embodiment and the means for solving the problems will be explained. In the embodiment, the first elastic member 30 corresponds to the "first elastic member", the second elastic member 40 corresponds to the "second elastic member", and the reinforcing member 50 corresponds to the "reinforcing member".
[0036] Furthermore, the correspondence between the main elements of the embodiment and the main elements of the invention described in the section on means for solving the problem is merely an example to specifically explain the form in which the embodiment implements the invention described in the section on means for solving the problem, and does not limit the elements of the invention described in the section on means for solving the problem. In other words, the interpretation of the invention described in the section on means for solving the problem should be based on the description in that section, and the embodiment is merely one specific example of the invention described in the section on means for solving the problem.
[0037] The above describes the forms for implementing this disclosure using embodiments, but this disclosure is not limited in any way to these embodiments, and can of course be implemented in various forms without departing from the gist of this disclosure.
[0038] [Note] [1] The structure of the present disclosure comprises: a first elastic member extending linearly along a predetermined direction; and a second elastic member extending curvedly along the predetermined direction and having a plurality of joints joined to the first elastic member at intervals along the predetermined direction, wherein the structure comprises a reinforcing member formed of a material with a lower mass density than the second elastic member and joined to the first or second surface of the second elastic member, wherein when a pressing force is applied to a non-joint portion, which is the portion of the second elastic member between two adjacent joints, and a non-joint corresponding portion, which is the portion of the reinforcing member corresponding to the non-joint portion, in a direction that brings the structure closer to the first elastic member, compressive stress in the predetermined direction is generated in the second elastic member and the reinforcing member, accompanied by bending deformation of the non-joint portion and the non-joint corresponding portion, and tensile stress in the predetermined direction is generated in the first elastic member.
[0039] The structure of this disclosure increases the total thickness of the second elastic member by joining a reinforcing member to the second elastic member. This suppresses buckling during bending deformation of the second elastic member and the reinforcing member while suppressing an increase in the overall weight of the structure compared to when the thickness of the second elastic member is increased.
[0040] [2] In the structure of the present disclosure (the structure described in [1]), the reinforcing member may have a thickness greater than or equal to that of the second elastic member.
[0041] [3] In the structure of the present disclosure (the structure described in [1] or [2]), the second elastic member may extend in a wave shape along the predetermined direction.
[0042] [4] In the structure of the present disclosure (the structure described in any one of [1] to [3]), two crimped portions may be formed by joining the ends of the first and second elastic members in the predetermined direction.
[0043] [5] In this case (the structure described in [4]), the crimping portion may be formed by folding at least one end of the first and second elastic members at least twice while the first and second elastic members are stacked on top of each other.
[0044] [6] In the structure of the present disclosure (the structure according to any one of [1] to [5]), a first unit and a second unit each having the first elastic member, the second elastic member, and the reinforcing member are provided, and the first elastic member of the first unit and the first elastic member of the second unit may be connected to each other.
[0045] [7] In the structure of the present disclosure (the structure according to any one of [1] to [5]), a first unit and a second unit each having the first elastic member, the second elastic member, and the reinforcing member are provided, and the first elastic member may be shared by the first and second units. Thereby, the height of the structure can be shortened as compared with the case where the first elastic member is not shared by the first and second units.
[0046] [8] In the structure of the present disclosure (the structure according to any one of [1] to [5]), a first unit and a second unit each having the first elastic member, the second elastic member, and the reinforcing member are provided, and the reinforcing member may be shared by the first and second units. Thereby, the height of the structure can be shortened as compared with the case where the reinforcing member is not shared by the first and second units.
[0047] [9] The manufacturing method of the structure of the present disclosure is a method for manufacturing a structure, including a step (A) of overlapping and arranging a second elastic member extending in a curved shape along the predetermined direction on a first elastic member extending linearly along the predetermined direction, a step (B) of joining the second elastic member to the first elastic member at a plurality of joint portions spaced apart along the predetermined direction after the step (A), and a step (C) of joining a reinforcing member formed of a material having a lower mass density than the second elastic member to the first surface or the second surface of the second elastic member before the step (B) or after the step (A). The structure is such that when a pressing force in a direction approaching the first elastic member is applied to a non-joint portion, which is a portion between two adjacent joint portions of the second elastic member, and a non-joint corresponding portion, which is a portion corresponding to the non-joint portion of the reinforcing member, a compressive stress in the predetermined direction is generated in the second elastic member and the reinforcing member, and a tensile stress in the predetermined direction is generated in the first elastic member, along with bending deformation of the non-joint portion and the non-joint corresponding portion. This is the gist of the matter.
[0048] The manufacturing method of the structure of the present disclosure manufactures a structure including the above three steps. By joining a reinforcing member to the second elastic member to increase their total thickness, buckling during bending deformation of the second elastic member and the reinforcing member can be suppressed while suppressing an increase in the overall weight of the structure compared to the case of increasing the thickness of the second elastic member.
[0049]
[10] In the manufacturing method of the structure of the present disclosure (the manufacturing method of the structure described in [9]), the step (B) may include a step (B1) of joining both end portions of the first and second elastic members in the predetermined direction to form two tightening portions.
[0050]
[11] In this case (the manufacturing method of the structure described in [9]), the step (B1) may be a step of forming the two tightening portions by folding back at least one of the both end portions of the first and second elastic members at least twice in a state where the first and second elastic members are overlapped.
Claims
1. A structure comprising: a first elastic member extending linearly along a predetermined direction; and a second elastic member extending curvedly along the predetermined direction and having a plurality of joints joined to the first elastic member at intervals along the predetermined direction, wherein the structure comprises a reinforcing member formed of a material with a lower mass density than the second elastic member and joined to the first or second surface of the second elastic member, wherein when a pressing force is applied in a direction that brings the structure closer to the first elastic member to a non-joint portion which is the portion of the second elastic member between two adjacent joints and a non-joint corresponding portion which is the portion of the reinforcing member corresponding to the non-joint portion, compressive stress in the predetermined direction is generated in the second elastic member and the reinforcing member, and tensile stress in the predetermined direction is generated in the first elastic member, accompanied by bending deformation of the non-joint portion and the non-joint corresponding portion.
2. A structure according to claim 1, wherein the reinforcing member has a thickness equal to or greater than that of the second elastic member.
3. A structure according to claim 1 or 2, wherein the second elastic member extends in a wave shape along the predetermined direction.
4. A structure according to claim 1 or 2, wherein two crimped portions are formed by joining the ends of the first and second elastic members in the predetermined direction.
5. The structure according to claim 4, wherein the crimping portion is formed by folding at least one end of the first and second elastic members at least twice when the first and second elastic members are stacked on top of each other.
6. A structure according to claim 1 or 2, comprising first and second units, each having a first elastic member, a second elastic member, and a reinforcing member, wherein the first elastic member of the first unit and the first elastic member of the second unit are connected to each other.
7. A structure according to claim 1 or 2, comprising first and second units, each having the first elastic member, the second elastic member, and the reinforcing member, wherein the first elastic member is shared by the first and second units.
8. A structure according to claim 1 or 2, comprising first and second units, each having a first elastic member, a second elastic member, and a reinforcing member, wherein the reinforcing member is shared by the first and second units.
9. A method for manufacturing a structure, comprising: (A) placing a second elastic member, which extends in a curved manner along a predetermined direction, on top of a first elastic member, which extends linearly along a predetermined direction; (B) joining the second elastic member to the first elastic member at a plurality of joints spaced apart along the predetermined direction, after step (A); and (C) joining a reinforcing member, which is made of a material with a lower mass density than the second elastic member, to a first or second surface of the second elastic member, after step (B) or before step (A), wherein when a pressing force is applied in a direction that brings the structure closer to the first elastic member to a non-joint portion, which is the portion of the second elastic member between two adjacent joints, and to a non-joint corresponding portion, which is the portion of the reinforcing member corresponding to the non-joint portion, compressive stress in the predetermined direction is generated in the second elastic member and the reinforcing member, and tensile stress in the predetermined direction is generated in the first elastic member, accompanied by bending deformation of the non-joint portion and the non-joint corresponding portion.
10. A method for manufacturing a structure according to claim 9, wherein step (B) includes a step (B1) of joining the ends of the first and second elastic members in the predetermined direction to form two crimped portions.
11. A method for manufacturing a structure according to claim 10, wherein step (B1) is a step of forming the two crimped portions by folding at least one end of the first and second elastic members at least twice while the first and second elastic members are stacked on top of each other.