Buffer structure and floor material

Abstract

To provide a buffer structure that is easy to manufacture by extrusion molding.SOLUTION: A buffer structure 100 comprises: a top plate 11 having a load-bearing upper surface; two leg parts 12, 13 extending in a direction away from a bottom surface of the top plate and spacing apart from each other in an X-axis direction on the bottom surface; and a connection part 15 arranged between the top plate and tips of the two leg parts and can connect body parts 12d, 13d of the two leg parts in the X-axis direction. The top plate, the two leg parts, and the connection part have shapes extending in a Y-axis direction on the bottom surface. The two leg parts have cross-sectional shapes that bend the body parts in directions adjacent to each other in an XY plane. By the above, it is possible to provide a buffer structure that is stiff against a small load when walking and allows for stable walking, and soft enough to withstand a large impact when falling, and can absorb the impact and prevent fractures and be manufactured easily (in particular, with high throughput and at low cost) by extrusion molding.SELECTED DRAWING: Figure 1A

Description

[Technical Field]

[0001] The present invention relates to a shock-absorbing structure and a flooring material including the same. [Background technology]

[0002] Cushioning materials that are installed under floors to absorb the impact of falls are known to prevent injuries such as fractures of the femur (particularly the trochanter) caused by falls by elderly people and others while walking on the floor. For example, Patent Document 1 discloses a cushioning structure that maintains stability during walking by having a large elastic modulus (i.e., small displacement and hardness) in response to small loads applied during walking, and that absorbs impact by having a small elastic modulus (i.e., large displacement and softness) in response to large impacts during falls. There is a demand for a cushioning structure that has such characteristics and is easy to manufacture. Patent Document 1: JP 2022-114615 A Summary of the Invention [Means for solving the problem]

[0003] In a first aspect of the present invention, there is provided a cushioning structure for absorbing impact, comprising: a top plate having an upper surface that receives a load; two legs that each extend in a first direction away from a lower surface of the top plate and are spaced apart from each other in a second direction on the lower surface; and a connecting portion that is arranged between the top plate and the tips of the two legs and can connect the body portions of the two legs in the second direction, wherein the top plate, the two legs, and the connecting portion have a shape that extends in a third direction on the lower surface that intersects the second direction.

[0004] In a second aspect of the present invention, there is provided a flooring material comprising a surface material and the buffer structure of the first aspect that supports the surface material and is placed on a subfloor.

[0005] The above summary of the invention does not list all of the features of the present invention, and subcombinations of these features may also be inventions. [Brief explanation of the drawings]

[0006] [Figure 1A] 1 is a perspective view showing the overall structure of a cushioning structure according to a first embodiment. [Figure 1B] The overall structure of the unit structure (drum-shaped structure) that constitutes the buffer structure is shown in perspective. [Figure 1C] The cross-sectional structure of the buffer structure (unit structure included therein) is shown. [Figure 2A] The cushioning principle of the unit structure (first contracted state) is shown. [Figure 2B] The cushioning principle of the unit structure (second contracted state) is shown. [Figure 2C] The buffering principle (buckling state) of the unit structure is shown. [Figure 3A] 10 shows a cross-sectional structure of a unit structure according to a first modified example. [Figure 3B] 10 shows a cross-sectional structure of a unit structure according to a second modified example. [Figure 3C] 10 shows a cross-sectional structure of a unit structure according to a third modified example. [Figure 4A] 10 shows another example of the bottom structure of the buffer structure. [Figure 4B] 10 shows another example of the bottom structure of the buffer structure. [Figure 5A] 10 shows a cross-sectional structure of a unit structure according to a fourth modified example. [Figure 5B] 10 shows the buffering principle of a unit structure according to a fourth modified example. [Figure 6] 1 shows a cross-sectional structure of a flooring material including a cushioning structure according to a first embodiment. [Figure 7A] 10 is a perspective view showing the overall structure of a cushioning structure according to a second embodiment. [Figure 7B] The overall structure of the unit structure (barrel-shaped structure) that constitutes the buffer structure is shown in perspective. [Figure 7C] The cross-sectional structure of the buffer structure (unit structure included therein) is shown. [Figure 8A] The cushioning principle of the unit structure (first contracted state) is shown. [Figure 8B]The cushioning principle of the unit structure (second contracted state) is shown. [Figure 8C] The buffering principle (buckling state) of the unit structure is shown. [Figure 9A] 10 shows a cross-sectional structure of a unit structure according to a fifth modified example. [Figure 9B] 13 shows a cross-sectional structure of a unit structure according to a sixth modified example. [Figure 9C] 13 shows a cross-sectional structure of a unit structure according to a seventh modified example. [Figure 10A] 10 shows another example of the bottom structure of the buffer structure. [Figure 10B] 10 shows another example of the bottom structure of the buffer structure. [Figure 11] 10 shows a cross-sectional structure of a flooring material including a cushioning structure according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0007] The present invention will be described below through embodiments of the invention, but the following embodiments do not limit the scope of the invention according to the claims. Furthermore, not all of the combinations of features described in the embodiments are necessarily essential to the solution of the invention.

[0008] First Embodiment FIG. 1A shows a perspective view of the overall structure of a buffer structure 100 according to a first embodiment. Here, the thickness direction of the buffer structure 100 is defined as the Z-axis direction, and the directions perpendicular to the Z-axis direction in a plane perpendicular to the Z-axis direction are defined as the X-axis direction and the Y-axis direction. The buffer structure 100, for example, constitutes a flooring material that supports a floor surface on a floor substructure S (see FIG. 6 ) and absorbs impacts applied to the floor surface. The floor substructure S may be a walking surface, such as a surface of a floor slab (concrete slab) in a reinforced concrete building, a surface with flooring or the like laid on top of that, a floorboard in a wooden building, or the ground. In particular, the buffer structure 100 is a structure that is rigid against small walking loads, allowing stable walking, and flexible against large impacts in the event of a fall, absorbing the impact and preventing fractures. This embodiment also provides a buffer structure 100 that can be easily manufactured by extrusion molding (particularly with high throughput and at low cost).

[0009] The buffer structure 100 is constructed by arranging a plurality of unit structures 10 in the X-axis direction, each of which has a thickness in the Z-axis direction and extends with a uniform cross section in the Y-axis direction, by integrally connecting the protruding portions 11b of the top plates 11 of the unit structures 10. Here, "extending with a uniform cross section" means that the XZ cross-section shape at any position in the Y-axis direction is the same or substantially the same, and this also applies hereinafter. Note that the buffer structure 100 according to this embodiment is constructed from six unit structures 10 arranged in the X-axis direction, but the number of unit structures 10 arranged can be determined arbitrarily. Furthermore, the width of the buffer structure 100 (unit structures 10) in the X-axis direction and the length of the unit structures 10 in the Y-axis direction can be determined arbitrarily. For example, the buffer structure 100 can be formed into a panel with a width of 30 to 90 cm and a length of 90 cm.

[0010] 1B and 1C respectively show the overall structure and cross-sectional structure of a unit structure (also called a drum-shaped structure) 10 that constitutes the buffer structure 100. The unit structure 10 is the smallest structural unit that constitutes the buffer structure 100. Here, FIG. 1B shows the overall structure of the unit structure 10 in perspective, and FIG. 1C shows the internal structure of the unit structure 10 on the XZ cross section. The unit structure 10 has a top plate 11, two legs 12 and 13, a bottom surface 14, and a connecting portion 15.

[0011] The tabletop 11 is a member having an upper surface that receives a load. In this embodiment, the tabletop 11 is a plate-like member that has a rectangular shape when viewed from above and extends with a uniform cross section in the Y-axis direction. Here, extending with a uniform cross section is equivalent to having the same or approximately the same shape in the XZ cross section at any position in the Y-axis direction, and this will be the same hereinafter. The size of the tabletop 11 is set to be sufficiently smaller than the area over which a load is applied when a person (including not only adults but also children) walks on the floor, i.e., the area over which the soles of the feet contact the floor when walking, and the area over which the knees strike the floor when falling. As a result, when not only adults but also children fall on the floor, the load applied to the floor can be absorbed by the multiple unit structures 10, preventing injuries such as fractures.

[0012] As will be described later, in order to support the surface material 240 and the like that form the floor surface on the buffer structure 100, the top plate 11 is not limited to being a plate that spreads over a whole surface, but may also have a frame shape that includes one opening extending in the Y-axis direction or multiple openings aligned in the Y-axis direction, as long as it can withstand the load applied to the unit structure 10 via the surface material 240 and the like. The shape of the opening may be any shape, such as a circle or a rectangle.

[0013] The top plate 11 has a protruding portion 11b that protrudes outward (in the ±X direction) from the point where the legs 12 and 13 (described later) are connected. The width of the protruding portion 11b is set to a degree that does not interfere with the legs 12 and 13 of the adjacent unit structure 10 when the legs 12 and 13 buckle (see FIG. 2C).

[0014] The two legs 12, 13 are members that extend away from the underside of the tabletop 11 (i.e., in the -Z direction) and support the tabletop 11 on the subfloor S. In this embodiment, the two legs 12, 13 are columnar or wall-like members that extend with a uniform cross section in the Y-axis direction. The two legs 12, 13 are arranged spaced apart from each other in one axial direction (i.e., the X-axis direction) on the underside. As a result, when a load is applied to the tabletop 11, the load is distributed to the two legs 12, 13, and the tabletop 11 can be stably supported.

[0015] The leg 12 has an upper portion 12a and a lower portion 12b. The upper portion 12a is the upper half of the leg 12, and its upper end is connected to the underside of the top plate 11 and inclined in the +X direction toward the center of the unit structure 10. The lower portion 12b is the lower half of the leg 12, and its upper end is connected to the lower end of the upper portion 12a and inclined in the -X direction toward the outside of the unit structure 10. The connecting portion of the upper portion 12a and the lower portion 12b forms a body portion 12d of the leg 12. By including the upper portion 12a and the lower portion 12b, the leg 12 has a shape that is bent convexly toward the center of the unit structure 10. This makes it easier for each of the upper portion 12a and the lower portion 12b to buckle outward (in the -X direction).

[0016] The leg 13 has an upper portion 13a and a lower portion 13b. The upper portion 13a is the upper half of the leg 13, and its upper end is connected to the underside of the top plate 11 and inclined in the -X direction toward the center of the unit structure 10. The lower portion 13b is the lower half of the leg 13, and its upper end is connected to the lower end of the upper portion 13a and inclined in the +X direction toward the outside of the unit structure 10. The connecting portion of the upper portion 13a and the lower portion 13b forms a body portion 13d of the leg 13. The leg 13, including the upper portion 13a and the lower portion 13b, has a shape that is bent convexly toward the center of the unit structure 10. This makes it easier for each of the upper portion 13a and the lower portion 13b to buckle outward (in the +X direction).

[0017] The two legs 12 and 13 have cross-sectional shapes that bend the respective trunks 12d and 13d toward each other in the XZ plane. This gives the unit structure 10 a drum-like shape with a narrow center in the Z-axis direction. The heights of the legs 12 and 13, i.e., the lengths of the upper portions 12a and 13a and the lower portions 12b and 13b, and the inclination angles with respect to the top plate 11, can be determined according to the deformation stroke required to absorb a load for one unit structure 10. Note that the +X side surface may be provided with a groove recessed in the -X direction or a portion with a small thickness so that the upper portion 12a and the lower portion 12b bend in the -X direction when an appropriate load is applied. Similarly, the -X side surface may be provided with a groove recessed in the +X direction or a portion with a small thickness so that the upper portion 13a and the lower portion 13b bend in the +X direction when an appropriate load is applied from the top plate 11. This makes it possible to more clearly transition the deformation mode of the legs 12, 13 when a load is applied, i.e., from the extension mode to the buckling mode or from the buckling mode to the extension mode. In other words, the legs 12, 13 become stiff until the load exceeds a threshold strength, and then soften when the load exceeds the threshold strength.

[0018] The bottom surface 14 is a member that connects the lower ends of the two legs 12, 13 in the X-axis direction. In this embodiment, the bottom surface 14 is a plate-like member that has a rectangular shape when viewed from above and extends with a uniform cross section in the Y-axis direction. The bottom surface 14 supports the unit structures 10 on the floor surface S and prevents the lower ends of the legs 12, 13 from sliding and spreading on the floor surface S. This facilitates buckling of the upper portions 12a, 13a and the lower portions 12b, 13b. Meanwhile, an opening 14a is provided between the legs 12, 13 of two adjacent unit structures 10. This allows the buffer structure 100 to bend at the connection point of the overhanging portion 11b of the top plate 11, widening the opening 14a, making it easier to roll up the unit structures 10 in the arrangement direction.

[0019] The connecting portion 15 is a member that is disposed between the tabletop 11 and the tips (and the bottom surface 14) of the two legs 12 and 13 in the Z-axis direction and connects the trunks 12d and 13d of the two legs 12 and 13 in the X-axis direction. In this embodiment, the connecting portion 15 is a plate-like member that has a rectangular shape when viewed from above and extends with a uniform cross section in the Y-axis direction. By integrally connecting the ends of the connecting portion 15 to the two legs 12 and 13 (respectively the trunks 12d and 13d), respectively, when a load is applied to the tabletop 11, it is possible to prevent the entire legs 12 and 13 from bending outward or inward, thereby inducing contraction in the Z-axis direction (a first contracted state, which will be described later).

[0020] By disposing the connection part 15 between the top plate 11 and the bottom surface 14, the space formed by the top plate 11, the bottom surface 14, and the two legs 12, 13 is divided into two spaces 10a, 10b. As a result, when a large load is applied to the top plate 11, the hand-held drum shape formed by the top plate 11, the bottom surface 14, and the two legs 12, 13 does not tilt in one direction in the X-axis direction, but rather the upper parts 12a, 13a and lower parts 12b, 13b of the legs 12, 13 each bend outward as described below, and the top plate 11, the bottom surface 14, and the connection part 15 come close to each other in the Z-axis direction, allowing the top plate 11 to be displaced significantly in the Z-axis direction.

[0021] The top plate 11, the two legs 12 and 13, the bottom surface 14, and the connecting portion 15 have shapes that extend with a uniform cross section in the Y-axis direction. This shape allows the unit structure 10 to be manufactured easily (particularly with high throughput and at low cost) by extrusion molding, and it is possible to maintain the rigidity of the legs 12 and 13 until they buckle with a small amount of material, while maximizing the deformation stroke.

[0022] 2A to 2C show the cushioning principle of the buffer structure 100 (unit structure 10). Note that one unit structure 10 out of the multiple unit structures 10 that make up the buffer structure 100 is shown as an example. Assume that a downward load (in the -Z direction) is applied from the upper surface side of the top plate 11 to the unit structure 10 in the no-load state shown in FIG. 1C.

[0023] 2A shows a front view of the unit structure 10 in the first contracted state. The load is assumed to be less than a predetermined threshold load. The upper portions 12a, 13a and lower portions 12b, 13b of the two legs 12, 13 supporting the top plate 11 contract in the directions of the white arrows within the XZ plane, causing the two legs 12, 13 to contract slightly in the Z-axis direction, displacing the top plate 11 slightly downward (in the direction of the solid arrow) to absorb the load.

[0024] FIG. 2B shows the unit structure 10 in a front view in the second contracted state. The load increases further but remains below a predetermined threshold load. The upper portions 12a, 13a and lower portions 12b, 13b further contract in the direction of the white arrows in the XZ plane, exerting inward pressure on the trunk portions 12d, 13d. In response, the connector 15 connecting the trunk portions 12d, 13d contracts in the X-axis direction, offsetting the pressure from the trunk portions 12d, 13d. This suppresses deformation of the unit structure 10 in the X-axis direction and provides rigidity against compressive deformation in the Z-axis direction. The two legs 12, 13 further contract in the Z-axis direction, displacing the top plate 11 slightly downward (in the direction of the solid arrow) to absorb the load.

[0025] 2C shows a front view of unit structure 10 in a buckled state. Suppose the load applied to tabletop 11 exceeds the threshold load. The two legs 12 and 13 supporting tabletop 11 bend (i.e., buckle) their upper parts 12a and 13a and lower parts 12b and 13b outward (in the direction of the white arrows), causing a large displacement in the Z-axis direction. This causes tabletop 11 to bend significantly downward (in the direction of the large black arrow) to absorb the load.

[0026] In this way, the cushioning structure 100 (unit structure 10) maintains the first contracted state and is rigid when subjected to small loads less than the threshold load applied when walking, providing stability when walking, and when subjected to a large impact greater than the threshold load when falling, it transitions via the second contracted state to a buckled state and becomes soft, allowing it to undergo large displacement and absorb the impact.

[0027] The legs 12 and 13 may have various cross-sectional shapes as long as the unit structure 10 buckles without deforming in the X-axis direction when a large impact is applied when the unit structure 10 falls over.

[0028] 3A shows the cross-sectional structure of a unit structure 10d1 according to a first modified example. The unit structure 10d1 includes a top plate 11, two legs 12 and 13, a bottom surface 14, and a connecting portion 15. The top plate 11, the bottom surface 14, and the connecting portion 15 are configured in the same manner as those in the unit structure 10 described above. The legs 12 (13) include an upper portion 12a (13a), a body portion 12c (13c), and a lower portion 12b (13b). The upper portion 12a (13a) is the upper portion of the leg 12 (13), and its upper end is connected to the underside of the top plate 11 and is inclined in the +X direction (-X direction) toward the center of the unit structure 10. The trunk 12c (13c) is a central portion of the leg 12 (13) located between the upper portion 12a (13a) and the lower portion 12b (13b), and its upper end is connected to the lower end of the upper portion 12a (13a) and extends in the Z-axis direction. The lower portion 12b (13b) is a lower portion of the leg 12, and its upper end is connected to the lower end of the trunk 12c (13c), and it is inclined in the -X direction (+X direction) toward the outside of the unit structure 10. The leg 12 includes the upper portion 12a (13a), the trunk 12c (13c), and the lower portion 12b (13b), and thus has a shape that is convexly bent toward the center of the unit structure 10. This makes it easier for each of the upper portion 12a (13a) and the lower portion 12b (13b) to buckle outward while increasing the length of the leg 12 in the Z-axis direction.

[0029] 3B shows the cross-sectional structure of a unit structure 10d2 according to a second modified example. The unit structure 10d2 includes a top plate 11, two legs 12 and 13, a bottom surface 14, and a connecting portion 15. The top plate 11, the bottom surface 14, and the connecting portion 15 are configured in the same manner as those in the unit structure 10 described above. The leg portion 12 (13) includes an upper portion 12a (13a) and a lower portion 12b (13b). The upper portion 12a (13a) is the upper portion of the leg portion 12 (13), and its upper end is connected to the lower surface of the top plate 11, extending in the Z-axis direction, and inclining in the +X direction (-X direction) toward the center of the unit structure 10. The lower portion 12b (13b) is the lower portion of the leg 12, and its upper end is connected to the lower end of the upper portion 12a (13a). It is inclined in the -X direction (+X direction) toward the outside of the unit structure 10 and extends in the Z-axis direction. The connecting portion of the upper portion 12a (13a) and the lower portion 12b (13b) forms the body portion 12d (13d) of the leg 12. The leg 12 includes the upper portion 12a (13a) and the lower portion 12b (13b), and thus has a shape that is bent convexly toward the center of the unit structure 10. This makes it easy for the upper portion 12a (13a) and the lower portion 12b (13b) to buckle outward.

[0030] 3C shows the cross-sectional structure of a unit structure 10d3 according to a third modified example. The unit structure 10d3 includes a top plate 11, two legs 12 and 13, a bottom surface 14, and a connecting portion 15. The top plate 11 and the bottom surface 14 are configured in the same manner as those in the unit structure 10 described above. The leg portion 12 (13) has an upper portion 12a (13a) and a lower portion 12b (13b). The upper portion 12a (13a) is the upper portion of the leg portion 12 (13), its upper end is connected to the lower surface of the top plate 11, and extends in the Z-axis direction. The lower portion 12b (13b) is the lower portion of the leg portion 12, its upper end is connected to the lower end of the upper portion 12a (13a), and is inclined in the -X direction (+X direction) toward the outside of the unit structure 10. The connection portion of the upper portion 12a (13a) and the lower portion 12b (13b) forms the body portion 12d (13d) of the leg portion 12. Here, the upper portion 13a of the leg portion 13 is longer than the upper portion 12a of the leg portion 12, and the body portion 12d is located higher than the body portion 13d. As a result, the connection portion 15 extends obliquely between the body portion 12d of the leg portion 12 and the body portion 13d of the leg portion 13 to connect them. This makes it easier for the upper portions 12a, 13a and the lower portions 12b, 13b, particularly the upper portion 13a and the lower portion 12b, to buckle.

[0031] 4A shows another example of the bottom structure of the buffer structure 100. Three unit structures 10 arranged in the X-axis direction are shown. However, an opening 14a is provided between the two legs 12, 13 included in each unit structure 10, and a bottom surface 14 is provided between the legs 12, 13 of adjacent unit structures 10. In other words, a bottom surface 14 is provided between the leg located on one side of the two legs 12, 13 of one unit structure 10 in the X-axis direction and the leg located on the other side of the two legs 12, 13 of the unit structure 10 adjacent to that side of the one unit structure 10 in the X-axis direction, connecting their tips.

[0032] 4B shows yet another example of the bottom structure of the buffer structure 100. Three unit structures 10 are shown arranged in the X-axis direction. However, a bottom surface 14 is provided between the two legs 12, 13 included in each unit structure 10, connecting the tips of the legs. A bottom surface 14 is also provided between the legs 12, 13 of adjacent unit structures 10, connecting the tips of the legs. In other words, a single bottom surface 14 is provided that connects the tips of all of the legs 12, 13 included in adjacent unit structures 10.

[0033] 5A shows the cross-sectional structure of a unit structure 10d4 according to a fourth modified example. The unit structure 10d4 includes a top plate 11, two legs 12 and 13, a bottom surface 14, and a connecting portion 15. The top plate 11, the two legs 12 and 13, and the bottom surface 14 are configured in the same manner as those in the previously described unit structure 10. The bottom surface 14 may be provided between the legs 12 and 13 of adjacent unit structures 10d4, or may be provided so as to connect all of the legs 12 and 13 of the buffer structure 100.

[0034] The connecting portion 15 is disposed between the top plate 11 and the tips (and bottom surface 14) of the two legs 12 and 13 in the Z-axis direction, and connects the trunks 12d and 13d of the two legs 12 and 13 in the X-axis direction. However, the connecting portion 15 in this example has two connecting members 15a and 15b fixed to the insides of the trunks 12d and 13d of the two legs 12 and 13, respectively. The two connecting members 15a and 15b are spaced apart when the two legs 12 and 13 are extended in the Z-axis direction (i.e., in an unloaded state).

[0035] 5B shows the buffering principle (first contracted state) of unit structure 10d4 according to the fourth modification. When a downward load (-Z direction) is applied from the top surface of tabletop 11, upper portions 12a, 13a and lower portions 12b, 13b of two legs 12, 13 contract in the XZ plane in the direction of the white arrows. As a result, two legs 12, 13 bend inward (X-axis direction), and the entire structure contracts in the Z-axis direction, bringing two connecting members 15a, 15b into close contact with each other. As a result, when a load is applied, tabletop 11 is instantly displaced downward (in the direction of the solid arrows) and transitions to the first contracted state shown in FIG. 2A. Further increase in load causes the tabletop to transition to a buckled state via a second contracted state, further displacing the tabletop downward, thereby enabling two-stage displacement.

[0036] 6 shows a cross-sectional structure of a floor material 200 including the cushioning structure 100 according to the first embodiment. The floor material 200 includes a surface material 240, an intermediate material 230, and the cushioning structure 100.

[0037] The surface material 240 is a layered material whose upper surface forms the floor surface (i.e., the walking surface). The surface material 240 may be made of hard materials such as wood, plywood, stone, cushion flooring made of vinyl chloride or the like, tiles, carpet, cork, long sheets, etc., so as to provide walking comfort. The surface material 240 may be integrally formed with the intermediate material 230.

[0038] The intermediate material 230 is a layer material that is placed between the surface material 240 and the buffer structures 100 to smooth out any unevenness on the top surface of the buffer structures 100 that are arranged on the subfloor S. As an example, the intermediate material 230 may be a foam layer formed using a foam material such as polyurethane. The intermediate material 230 is placed across at least two buffer structures 100. This distributes a local load applied to the surface material 240 to the multiple buffer structures 100.

[0039] A plurality of buffer structures 100 are arranged on the underfloor S, and support the surface materials 240 and the intermediate materials 230. The buffer structures 100 are configured as described above, and absorb the load applied via the surface materials 240.

[0040] The cushioning structure 100 according to this embodiment can be manufactured by extrusion molding. A material is poured into a mold having an opening with a cross-sectional shape equal to that of the cushioning structure 100 shown in FIG. 1C, and then pressure is applied to extrude the material through the opening, thereby forming the cushioning structure 100, which extends in one axis direction with a uniform cross-section. The cushioning structure 100 is formed using an elastic material such as NR rubber, thermoplastic elastomer, or polyvinyl chloride, so that the buckled legs 12 and 13 return to their upright position when the load is released. This gives the legs 12 and 13 a rubber hardness of 10 to 100, preferably 50 to 80.

[0041] With the floor material 200 configured as described above, when a load is applied from the upper surface side of the tabletop 11 to the buffer structure 100 arranged with the legs 12, 13 erected on the floor base S, the legs 12, 13 contract in the Z-axis direction to absorb the load until the load exceeds a threshold load, and when the load exceeds the threshold load, the legs 12, 13 (upper parts 12a, 13a and lower parts 12b, 13b) bend convexly in the XZ plane (i.e., buckle) to soften, causing the tabletop 11 to displace significantly in the Z-axis direction to absorb the load. As a result, the floor material 200 is hard against small loads applied when walking, providing stability when walking, and soft against large impacts when falling, displacing significantly to absorb the impact.

[0042] The cushioning structure 100 according to this embodiment includes a tabletop 11 having an upper surface that receives a load, two legs 12 and 13 that extend away from the lower surface of the tabletop 11 and are spaced apart from each other in the X-axis direction on the lower surface, and a connecting portion 15 that is disposed between the tabletop 11 and the tips of the two legs 12 and 13 and that can connect the trunks 12d and 13d of the two legs 12 and 13 in the X-axis direction. The tabletop 11, the two legs 12 and 13, and the connecting portion 15 have a shape that extends in the Y-axis direction on the lower surface. Here, the two legs 12 and 13 have a cross-sectional shape that bends the trunks 12d and 13d toward each other within the XZ plane. This makes it possible to provide a cushioning structure 100 that is rigid against small loads during walking, enabling stable walking, and flexible against large impacts during falls, absorbing the impact and preventing fractures. The cushioning structure 100 can be easily manufactured by extrusion molding (particularly with high throughput and at low cost).

[0043] The flooring material 200 according to this embodiment includes a surface material 240 and a buffer structure 100 that supports the surface material 240 and is placed on the subfloor S. The buffer structure 100 supports the surface material 240 on the subfloor S, making the flooring material 200 hard against small loads applied when walking, providing stability when walking, and soft against large impacts when falling, and capable of displacing greatly to absorb the impact.

[0044] In the buffer structure 100 (unit structures 10, 10d1, 10d2, 10d3, 10d4) according to the first embodiment and the modified examples, the upper portions 12a, 13a and lower portions 12b, 13b of the two legs 12, 13 have been described as bending outward (i.e., buckling), but the upper portions 12a, 13a and lower portions 12b, 13b may each be formed to bend inward, or some of them may be formed to bend outward and the rest to bend inward.

[0045] Second Embodiment FIG. 7A shows a perspective view of the overall structure of a buffer structure 120 according to the second embodiment. Here, the thickness direction of the buffer structure 120 is the Z-axis direction, and the directions perpendicular to the Z-axis direction in a plane perpendicular to the Z-axis direction are the X-axis direction and the Y-axis direction. Similar to the buffer structure 100 according to the first embodiment, the buffer structure 120 constitutes a flooring material that supports the floor surface on the floor substrate S (see FIG. 11 ) and absorbs impacts applied to the floor surface. The buffer structure 120 is hard enough to withstand small walking loads, allowing for stable walking, yet soft enough to withstand large impacts during falls, absorbing impacts and preventing fractures. Furthermore, it can be easily manufactured by extrusion molding (especially with high throughput and low cost). Unless otherwise specified, explanations of features similar to those of the buffer structure 100 according to the first embodiment will be omitted.

[0046] 7B and 7C show the overall structure and cross-sectional structure of a unit structure (also called a barrel-shaped structure) 110 constituting the buffer structure 120, respectively. The unit structure 110 is the smallest structural unit constituting the buffer structure 120. The buffer structure 120 is constructed by arranging a plurality of unit structures 110 in the X-axis direction, each of which has a thickness in the Z-axis direction and extends with a uniform cross section in the Y-axis direction, by integrally connecting the protruding portions 11b of the top plates 11 of the unit structures 110. Here, "extending with a uniform cross section" means that the shapes of the X-Z cross sections at any position in the Y-axis direction are identical or substantially identical, and this will be the same hereinafter. Note that FIG. 7B shows the overall structure of the unit structure 110 in a perspective view, and FIG. 7C shows the internal structure of the unit structure 110 on the X-Z cross section. The unit structure 110 includes a top plate 11, two legs 12 and 13, a bottom surface 14, and a connecting portion 15.

[0047] The top plate 11 is a member having an upper surface that receives a load, and is configured in the same manner as that in the buffer structure 100 according to the first embodiment.

[0048] The two legs 12 and 13 are members that extend in a direction away from the underside of the tabletop 11 (that is, in the −Z direction) and support the tabletop 11 on the subfloor S.

[0049] The leg 12 has an upper portion 12a and a lower portion 12b. The upper portion 12a is the upper half of the leg 12, and its upper end is connected to the lower surface of the top plate 11 and inclined in the -X direction toward the outside of the unit structure 110. The lower portion 12b is the lower half of the leg 12, and its upper end is connected to the lower end of the upper portion 12a and inclined in the +X direction toward the center of the unit structure 110. The connecting portion of the upper portion 12a and the lower portion 12b forms a body portion 12d of the leg 12. By including the upper portion 12a and the lower portion 12b, the leg 12 has a shape that is bent convexly toward the outside of the unit structure 110. This makes it easier for each of the upper portion 12a and the lower portion 12b to buckle inward (in the +X direction).

[0050] The leg 13 has an upper portion 13a and a lower portion 13b. The upper portion 13a is the upper half of the leg 13, and its upper end is connected to the underside of the top plate 11 and inclined in the +X direction toward the outside of the unit structure 110. The lower portion 13b is the lower half of the leg 13, and its upper end is connected to the lower end of the upper portion 13a and inclined in the -X direction toward the center of the unit structure 110. The connecting portion of the upper portion 13a and the lower portion 13b forms a body portion 13d of the leg 13. By including the upper portion 13a and the lower portion 13b, the leg 13 has a shape that is bent convexly toward the outside of the unit structure 110. This makes it easier for each of the upper portion 13a and the lower portion 13b to buckle inward (in the -X direction).

[0051] The two legs 12 and 13 have cross-sectional shapes that bend the respective trunks 12d and 13d in directions that separate them from each other in the XZ plane, thereby giving the unit structure 110 a barrel shape with a wider center in the Z-axis direction.

[0052] The bottom surface 14 is a member that connects the lower ends of the two leg portions 12, 13 in the X-axis direction, and is configured in the same manner as that in the cushioning structure 100 according to the first embodiment.

[0053] The connection portion 15 is a member that is arranged between the top plate 11 and the tips (and bottom surface 14) of the two legs 12, 13 in the Z-axis direction, and connects the respective body portions 12d, 13d of the two legs 12, 13 in the X-axis direction, and is configured in the same manner as that in the buffer structure 100 of the first embodiment.

[0054] By disposing the connection portion 15 between the top plate 11 and the bottom surface 14, the space formed by the top plate 11, the bottom surface 14, and the two legs 12, 13 is divided into two spaces 110a, 110b. As a result, when a large load is applied to the top plate 11, the barrel shape formed by the top plate 11, the bottom surface 14, and the two legs 12, 13 does not tilt in one direction in the X-axis direction, but rather the upper parts 12a, 13a and lower parts 12b, 13b of the legs 12, 13 each bend inward as described below, and the top plate 11, the bottom surface 14, and the connection portion 15 become closer in the Z-axis direction, allowing the top plate 11 to be displaced significantly in the Z-axis direction.

[0055] The top plate 11, the two legs 12 and 13, the bottom surface 14, and the connecting portion 15 have shapes that extend with a uniform cross section in the Y-axis direction. This shape allows the unit structure 110 to be easily manufactured (particularly with high throughput and at low cost) by extrusion molding, and it is possible to maintain the rigidity of the legs 12 and 13 until they buckle with a small amount of material and maximize the deformation stroke.

[0056] 8A to 8C show the buffering principle of the buffer structure 120 (unit structure 110). Note that one unit structure 110 out of the multiple unit structures 110 that make up the buffer structure 120 is shown as an example. Assume that a downward load (in the -Z direction) is applied from the upper surface side of the top plate 11 to the unit structure 110 in the no-load state shown in FIG. 7C.

[0057] 8A shows a front view of the unit structure 110 in the first contracted state. The load is assumed to be less than a predetermined threshold load. The upper portions 12a, 13a and lower portions 12b, 13b of the two legs 12, 13 supporting the tabletop 11 contract in the directions of the white arrows in the XZ plane, causing the two legs 12, 13 to contract slightly in the Z-axis direction, displacing the tabletop 11 slightly downward (in the direction of the solid arrow) to absorb the load.

[0058] FIG. 8B shows the unit structure 110 in a front view in the second contracted state. The load increases further but remains below a predetermined threshold load. The upper portions 12a, 13a and lower portions 12b, 13b further contract in the XZ plane in the directions indicated by the white arrows, applying outward stress to the trunk portions 12d, 13d. In response, the connector 15 connecting the trunk portions 12d, 13d expands in the X-axis direction, offsetting the tension from the trunk portions 12d, 13d. This suppresses deformation of the unit structure 110 in the X-axis direction and provides rigidity against compressive deformation in the Z-axis direction. The two legs 12, 13 further contract in the Z-axis direction, displacing the top plate 11 slightly downward (in the direction indicated by the solid arrows) to absorb the load.

[0059] 8C shows a front view of unit structure 110 in a buckled state. Suppose the load applied to tabletop 11 exceeds the threshold load. The two legs 12, 13 supporting tabletop 11 bend (i.e., buckle) their upper parts 12a, 13a and lower parts 12b, 13b inward (in the direction of the white arrows), causing a large displacement in the Z-axis direction. This causes tabletop 11 to bend significantly downward (in the direction of the large black arrow) to absorb the load.

[0060] In this way, the buffer structure 120 (unit structure 110) maintains the first contracted state and is rigid when subjected to small loads less than the threshold load applied when walking, providing stability when walking, and when subjected to a large impact greater than the threshold load when falling, it transitions via the second contracted state to a buckled state and becomes soft, allowing it to undergo large displacements and absorb the impact.

[0061] The legs 12 and 13 may have various cross-sectional shapes as long as the unit structure 110 buckles without deforming in the X-axis direction when a large impact is applied when the unit structure 110 is overturned.

[0062] 9A shows the cross-sectional structure of a unit structure 110d1 according to a fifth modified example. The unit structure 110d1 includes a top plate 11, two legs 12 and 13, a bottom surface 14, and a connecting portion 15. The top plate 11, the bottom surface 14, and the connecting portion 15 are configured in the same manner as those in the previously described unit structure 110. The legs 12 (13) include an upper portion 12a (13a), a body portion 12c (13c), and a lower portion 12b (13b). The upper portion 12a (13a) is the upper portion of the leg 12 (13), and its upper end is connected to the underside of the top plate 11 and is inclined in the -X direction (+X direction) toward the outside of the unit structure 110d1. The trunk 12c (13c) is the central portion of the leg 12 (13) located between the upper portion 12a (13a) and the lower portion 12b (13b), and its upper end is connected to the lower end of the upper portion 12a (13a) and extends in the Z-axis direction. The lower portion 12b (13b) is the lower portion of the leg 12 (13), and its upper end is connected to the lower end of the trunk 12c (13c), and it is inclined in the +X direction (-X direction) toward the center of the unit structure 110d1. The leg 12 (13) includes the upper portion 12a (13a), trunk 12c (13c), and lower portion 12b (13b), and has a shape that is convexly curved toward the outside of the unit structure 110d1. This makes it easier for the upper portion 12a (13a) and the lower portion 12b (13b) to buckle outward while increasing the length of the leg portion 12 (13) in the Z-axis direction.

[0063] 9B shows the cross-sectional structure of a unit structure 110d2 according to the sixth modified example. The unit structure 110d2 includes a top plate 11, two legs 12 and 13, a bottom surface 14, and a connecting portion 15. The top plate 11, the bottom surface 14, and the connecting portion 15 are configured in the same manner as those in the previously described unit structure 110. The leg portion 12 (13) includes an upper portion 12a (13a) and a lower portion 12b (13b). The upper portion 12a (13a) is the upper portion of the leg portion 12 (13), and its upper end is connected to the lower surface of the top plate 11. The upper portion 12a (13a) is inclined in the -X direction (+X direction) toward the outside of the unit structure 110d2 and bent in the +X direction (-X direction) toward the center of the unit structure 110d2. The lower portion 12b (13b) is the lower portion of the leg portion 12 (13), and its upper end is connected to the lower end of the upper portion 12a (13a). It is inclined in the -X direction (+X direction) toward the outside of the unit structure 110d2 and bent in the +X direction (-X direction) toward the center of the unit structure 110d2. The connecting portion of the upper portion 12a (13a) and the lower portion 12b (13b) forms the body portion 12d (13d) of the leg portion 12 (13). The leg portion 12 (13) includes the upper portion 12a (13a) and the lower portion 12b (13b), and thus has a W-shaped bent shape toward the center of the unit structure 110d2. This increases the length of the leg portion 12 (13) in the Z-axis direction, making it easier for each of the upper portion 12a (13a) and the lower portion 12b (13b) to buckle outward.

[0064] 9C shows the cross-sectional structure of a unit structure 110d3 according to the seventh modification. The unit structure 110d3 includes a top plate 11, two legs 12 and 13, a bottom surface 14, and a connecting portion 15. The top plate 11 and the bottom surface 14 are configured in the same manner as those in the unit structure 110 described above. The leg portion 12 (13) has an upper portion 12a (13a) and a lower portion 12b (13b). The upper portion 12a (13a) is the upper portion of the leg portion 12 (13), its upper end is connected to the lower surface of the top plate 11, and extends in the Z-axis direction. The lower portion 12b (13b) is the lower portion of the leg portion 12, its upper end is connected to the lower end of the upper portion 12a (13a), and it is inclined in the +X direction (-X direction) toward the center of the unit structure 110d3. The connection portion of the upper portion 12a (13a) and the lower portion 12b (13b) forms the trunk portion 12d (13d) of the leg portion 12 (13). Here, the upper portion 13a of the leg portion 13 is longer than the upper portion 12a of the leg portion 12, and the trunk portion 12d is located higher than the trunk portion 13d. As a result, the connection portion 15 extends obliquely between the trunk portion 12d of the leg portion 12 and the trunk portion 13d of the leg portion 13 to connect them. This makes the legs 12 and 13 longer in the Z-axis direction, and makes it easier for the upper portions 12a and 13a and the lower portions 12b and 13b, particularly the upper portion 13a and the lower portion 12b, to buckle.

[0065] 10A shows another example of the bottom structure of a buffer structure 120. Three unit structures 110 arranged in the X-axis direction are shown. However, an opening 14a is provided between the two legs 12, 13 included in each unit structure 110, and a bottom surface 14 is provided between the legs 12, 13 of adjacent unit structures 110. In other words, a bottom surface 14 is provided between the leg located on one side of the two legs 12, 13 of one unit structure 110 in the X-axis direction and the leg located on the other side of the two legs 12, 13 of the unit structure 110 adjacent to that side of the one unit structure 110 in the X-axis direction, connecting their tips.

[0066] 10B shows yet another example of the bottom structure of the buffer structure 120. Three unit structures 110 arranged in the X-axis direction are shown. However, a bottom surface 14 connecting the tips of the two legs 12, 13 included in each unit structure 110 is provided between them, and a bottom surface 14 connecting the tips of the legs 12, 13 of adjacent unit structures 110 is also provided between them. In other words, a single bottom surface 14 connecting the tips of all of the legs 12, 13 included in adjacent unit structures 110 is provided.

[0067] 11 shows the cross-sectional structure of a flooring material 220 including a buffer structure 120 according to the second embodiment. The flooring material 220 includes a surface material 240, an intermediate material 230, and a buffer structure 120. The surface material 240 and the intermediate material 230 are configured in the same manner as those in the flooring material 200 according to the first embodiment described above. A plurality of buffer structures 120 are arranged on the floor substrate S, and support the surface materials 240 and the intermediate materials 230. The buffer structure 120 is configured as described above, and absorbs the load applied via the surface material 240.

[0068] The buffer structure 120 according to this embodiment can also be manufactured by extrusion molding, similarly to the buffer structure 100 according to the first embodiment.

[0069] With the floor material 220 configured as described above, when a load is applied from the upper surface side of the tabletop 11 to the buffer structure 120 arranged with the legs 12, 13 erected on the floor base S, the legs 12, 13 contract in the Z-axis direction to absorb the load until the load exceeds a threshold load, and when the load exceeds the threshold load, the legs 12, 13 (upper parts 12a, 13a and lower parts 12b, 13b) bend concavely in the XZ plane (i.e., buckle) to soften, causing the tabletop 11 to displace significantly in the Z-axis direction to absorb the load. As a result, the floor material 220 is hard against small loads applied when walking, providing stability when walking, and soft against large impacts when falling, displacing significantly to absorb the impact.

[0070] The cushioning structure 120 according to this embodiment includes a tabletop 11 having an upper surface that receives a load, two legs 12 and 13 that extend away from the lower surface of the tabletop 11 and are spaced apart from each other in the X-axis direction on the lower surface, and a connecting portion 15 that is disposed between the tabletop 11 and the tips of the two legs 12 and 13 and that can connect the trunks 12d and 13d of the two legs 12 and 13 in the X-axis direction. The tabletop 11, the two legs 12 and 13, and the connecting portion 15 have a shape that extends in the Y-axis direction on the lower surface. Here, the two legs 12 and 13 have a cross-sectional shape that bends the trunks 12d and 13d in the XZ plane. This makes it possible to provide a cushioning structure 120 that is rigid against small loads during walking, enabling stable walking, and flexible against large impacts during falls, absorbing the impact and preventing fractures. The cushioning structure 120 can be easily manufactured by extrusion molding (particularly with high throughput and at low cost).

[0071] The floor material 220 according to this embodiment includes a surface material 240 and a buffer structure 120 that supports the surface material 240 and is placed on the subfloor S. The buffer structure 120 supports the surface material 240 on the subfloor S, making the floor material 220 hard against small loads applied when walking, providing stability when walking, and soft against large impacts when falling, and capable of displacing greatly to absorb the impact.

[0072] In the buffer structure 120 (unit structures 110, 110d1, 110d2, 110d3) according to the second embodiment and the modified example, the upper portions 12a, 13a and lower portions 12b, 13b of the two legs 12, 13 have been described as bending inward (i.e., buckling), but the upper portions 12a, 13a and lower portions 12b, 13b may each be formed to bend outward, or some of them may be formed to bend inward and the rest to bend outward.

[0073] Although the present invention has been described above using embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments. It will be apparent to those skilled in the art that various modifications and improvements can be made to the above embodiments. It is clear from the claims that such modifications and improvements can also be included within the technical scope of the present invention.

[0074] It should be noted that the execution order of each process, such as operations, procedures, steps, and stages, in the devices, systems, programs, and methods shown in the claims, specifications, and drawings is not specifically stated as "before," "prior to," etc., and that the processes can be performed in any order unless the output of a previous process is used in a subsequent process. Even if the operational flow in the claims, specifications, and drawings is described using "first," "next," etc. for convenience, this does not mean that the processes must be performed in this order. [Explanation of symbols]

[0075] 10, 10d1, 10d2, 10d3, 10d4...unit structure, 10a, 10b...space, 11...top plate, 11b...extension, 12, 13...legs, 12a, 13a...upper part, 12b, 13b...lower part, 12c, 12d, 13c, 13d...body part, 14...bottom, 14a...opening, 15...connection part, 15a, 15b...connection member, 100, 120...buffer structure, 110, 110d1, 110d2, 110d3...unit structure, 200, 220...floor material, 230...intermediate material, 240...surface material, S...floor underlay (floor surface).

Claims

1. A shock-absorbing structure that absorbs shock, a top plate having an upper surface that receives a load; two legs each extending in a first direction away from a lower surface of the top plate and spaced apart from each other in a second direction on the lower surface; a connecting portion disposed between the top plate and the tips of the two legs and capable of connecting the trunks of the two legs in the second direction; wherein the top plate, the two legs, and the connecting portion have shapes that extend on the lower surface in a third direction that intersects with the second direction.

2. The cushioning structure according to claim 1 , wherein the two legs have cross-sectional shapes that bend the respective trunks in directions that bring the trunks closer to each other within a plane that includes the first direction and the second direction.

3. 3. The cushioning structure according to claim 2, wherein the connecting portion has two connecting members fixed to the two leg portions, respectively, and the two connecting members are spaced apart when the two leg portions are extended in the first direction and contact each other when the two leg portions are bent in the second direction and contracted in the first direction.

4. The cushioning structure according to claim 1 , wherein the two legs have cross-sectional shapes that curve in a direction that separates the respective trunk portions from each other within a plane that includes the first direction and the second direction.

5. The cushioning structure according to claim 2 , wherein the connecting portion integrally connects end portions of the two legs to the trunk portions of the two legs.

6. The cushioning structure according to claim 1 , further comprising a first bottom surface connecting the tips of the two legs.

7. another leg portion having a shape extending in the first direction from the lower surface of the top plate and extending in the third direction, the other leg portion being adjacent to one side of the two legs in the second direction; a second bottom surface connecting a tip of one of the two legs located on one side in the second direction and a tip of the other leg; The cushioning structure of claim 1 further comprising:

8. The cushioning structure according to claim 7 , wherein the second bottom surface further connects the tips of the two legs.

9. A flooring material comprising a surface material and the buffer structure according to any one of claims 1 to 8, which is placed on a subfloor and supports the surface material.

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