Buffer structure and floor material

Abstract

A buffer structure 100 comprises: a top panel 11 having an upper surface that receives a load; and at least one leg part 12 extending in the Z-axis direction from the lower surface of the top panel, and having a cross-sectional shape bent into a projection toward one side in an XY plane. Thus, when a load is applied from the upper surface side of the top panel to the buffer structure disposed with the leg part standing on a floor substrate, the leg part absorbs the load by contracting in the Z-axis direction until the load exceeds a threshold load. Once the load exceeds the threshold load, the leg is bent (that is, buckled) toward the opposite side while expanding the cross section bent into a projection in a ZY plane, and is displaced significantly to become soft. After the displacement, the leg part contracts in the Z-axis direction through abutting of the upper side and the lower side of the side surface on one side, whereby the leg part can further absorb the load.

Description

Buffer structure and floor material

[0001] The present invention relates to a shock-absorbing structure and a floor material equipped with the shock-absorbing structure.

[0002] To prevent injuries such as femoral fractures (especially trochanteric fractures) caused by falls by elderly people walking on a floor, cushioning materials that are installed under the floor and absorb the impact of falls are known. For example, Patent Document 1 discloses a flooring material with a foam layer formed using a foam material such as polyurethane. The elastic modulus of such a foam layer increases linearly with the applied load. Therefore, if the elastic modulus is set high (small displacement, i.e., hard) for small loads applied during walking, stability during walking is maintained, but it cannot absorb large impacts during falls, leading to fractures. Conversely, if the elastic modulus is set low (large displacement, i.e., soft) to absorb large impacts during falls, the foam layer will be too soft to displace even under small loads, making walking difficult. Therefore, a flooring material with a high elastic modulus (i.e., hard) for small loads during walking and a low elastic modulus (i.e., soft) for large impacts during falls is needed, as disclosed in Patent Document 2. Patent Document 1: JP 2019-178519 A Patent Document 2: JP 2022-114615 A General disclosure

[0003] (Item 1) A cushioning structure for cushioning an impact may be provided. The cushioning structure may include a tabletop having an upper surface that receives a load. The cushioning structure may include at least one leg extending in a first direction away from a lower surface of the tabletop and having a cross-sectional shape that is bent convexly toward one side in a second direction within a plane intersecting the first direction. (Item 2) The at least one leg may be inclined toward the opposite side of the second direction with respect to the lower surface of the tabletop. (Item 3) The at least one leg may have a tip end having a shape similar to the cross-sectional shape. (Item 4) The at least one leg may have a cross-sectional shape that is bent convexly toward one side in the second direction. (Item 5) The at least one leg may have a recess formed in at least a portion of a corner on one side in the second direction. (Item 6) The recess may be formed from a base end to a tip end of the at least one leg. (Item 7) The at least one leg may include a plurality of legs arranged along the periphery of the tabletop, with a radial direction based on the center of the tabletop as the second direction, and an outer side and an inner side with respect to the radial direction as the one side and the opposite side, respectively. (Item 8) Two adjacent legs among the plurality of legs may form a gap between them. (Item 9) The gap between the two legs may extend from the underside of the tabletop toward the first direction. (Item 10) The tabletop may have a frame shape including an opening in the center. (Item 11) The tabletop may have a rectangular shape. The plurality of legs may be arranged at corners of the tabletop. (Item 12) The tabletop may include a protruding portion protruding outward from a point where the plurality of legs are connected. (Item 13) The thickness of the protruding portion may be equal to or smaller than the thickness of the plurality of legs. (Item 14) At least one of the plurality of legs may include a rib formed between the underside of the protruding portion and an outer side surface. (Item 15) The plurality of tabletops may be arranged in at least one direction between the second direction and a third direction intersecting the first direction and the second direction, with the protruding portions connected to each other. The plurality of legs may be provided for each of the plurality of tabletops.(Item 16) The top plate may have an end surface extending in the first direction from a side surface of the protruding portion of the top plate located outermost among the plurality of top plates. (Item 17) The top plate may have a claw portion that engages with a claw receiving portion of a top plate of another buffer structure and / or a claw receiving portion that engages with a claw portion of a top plate of another buffer structure. (Item 18) The top plate may further have a bottom surface that connects to the tip ends of each of the plurality of legs. (Item 19) The bottom surface may include a central portion located in the center of the plurality of legs and a plurality of connecting portions that connect from the central portion to the tip ends of the plurality of legs, respectively. (Item 20) The top plate may have a locking member that extends from between two adjacent legs of the plurality of legs toward the outside of the top plate and has a shape with a tip that is wider than the gap between the two legs. (Item 21) The at least one leg may include a plurality of legs arranged adjacent to each other near the center of the tabletop, with a radial direction based on the center of the tabletop as the second direction, and an inner side and an outer side with respect to the radial direction as the one side and the opposite side to the one side, respectively.

[0004] (Item 22) A floor support structure may be provided, which includes a surface material and the buffer structure according to any one of items 1 to 21, which supports the surface material and is placed on the 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.

[0006] 1 shows a perspective view of the overall structure of the buffer structure according to this embodiment. 2 shows a perspective view of the overall structure of a unit structure that constitutes the buffer structure. 3 shows a perspective view of the internal structure of the unit structure, with some parts omitted. 4 shows a top view of the structure of the unit structure. 5 shows a bottom view of the structure of the unit structure. 6 shows a side view of the structure of the unit structure. 7 shows a state in which buffer structures are stacked. 8 shows a state in which buffer structures are rolled up. 9 shows the structure of the sliding rib. 10 shows the function of the sliding rib (a state in which an end of a buffer structure rests on an end of another buffer structure). 11 shows the function of the sliding rib (a state in which an end of a buffer structure slides on the sliding rib of another buffer structure). 12 shows the function of the sliding rib (a state in which a buffer structure is parallel to another buffer structure). 13 shows a side view of the structure of the reinforcing rib. 14 shows a bottom view of the structure of the reinforcing rib. 15 shows a perspective view of the structure of the joint structure. 16 shows a side view of the structure of the joint structure. 17 shows a perspective view of two buffer structures (two unit structures) connected by a joint structure. 1 shows a side view of two buffer structures (two unit structures) connected by a joint structure. 1 shows the buffering principle of the buffer structure (unit structure) (unloaded state). 1 shows the buffering principle of the buffer structure (unit structure) (contracted state). 1 shows the buffering principle of the buffer structure (unit structure) (buckled state). 1 shows the buffering principle of the buffer structure (unit structure) (collapsed state). 1 shows the cross-sectional structure of a flooring material including a buffer structure according to this embodiment. 1 shows the buffering characteristics of the buffer structure. 1 shows a perspective view of the overall structure of another unit structure constituting the buffer structure. 1 shows a second deformation mode (closed leg state) of the buffer structure (unit structure). 1 shows the second deformation mode (most closed leg state) of the buffer structure (unit structure). 1 shows a third deformation mode (open leg state) of the buffer structure (unit structure). 1 shows the third deformation mode (most open leg state) of the buffer structure (unit structure). 1 shows a perspective view of the overall structure of a unit structure according to a modified example. 1 shows a perspective view of the internal structure of a unit structure according to a modified example, with some parts omitted. 1 shows a top view of the structure of a unit structure according to a modified example; a bottom view of the structure of a unit structure according to a modified example; a side view of the structure of a unit structure according to a modified example; a structure of a sliding rib in a unit structure according to a modified example; and a perspective view of the structure of a locking member in a unit structure according to a modified example.10 is a perspective view showing a state in which a unit structure according to a modified example is connected to another unit structure by a locking member.

[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 as claimed. Furthermore, not all of the combinations of features described in the embodiments are necessarily essential to the solution of the invention.

[0008] In the embodiments of the present invention, the size of a component may be described using "approximately." It should be noted that this means that the size is accurate to at least significant figures (significant digits) and includes uncertainty outside of the significant figures. For example, "approximately 1 mm" includes uncertainty of about 0.1 mm.

[0009] FIG. 1 shows a perspective view of the overall structure of a buffer structure 100 according to this embodiment. Here, the thickness direction of the buffer structure 100 is defined as the Z-axis direction, and 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 constitutes, for example, a flooring material that supports a floor surface on a floor substructure S (see FIG. 9A , etc.) and absorbs impacts applied to the floor surface. The floor substructure S may be a walking surface, such as one side of a floor slab (concrete slab) in a reinforced concrete building, a side surface on which flooring or the like is laid, a floorboard in a wooden building, or the ground. In particular, the buffer structure 100 is a structure that is rigid against small loads during walking, allowing stable walking, and flexible against large impacts during falls, absorbing the impact and preventing fractures.

[0010] The buffer structure 100 is configured by arranging a plurality of unit structures 10, each having a thickness in the Z-axis direction, in a line in the X-axis or Y-axis direction, or in a matrix in the X and Y directions, by integrally connecting the protruding portions 11b of the top plates 11 of each unit structure 10. Note that the buffer structure 100 according to this embodiment is configured from a total of nine unit structures 10, three in each of the X-axis and Y-axis directions, but the number of unit structures 10 arranged in each of the X-axis and Y-axis directions can be determined arbitrarily, and the lengths of the buffer structure 100 in each of the X-axis and Y-axis directions can also be determined arbitrarily.

[0011] Figures 2A to 2E show the structure of a unit 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. 2A shows the overall structure of the unit structure 10 in perspective, Fig. 2B shows the internal structure of the unit structure 10 in perspective with some parts omitted, Fig. 2C shows the structure of the unit structure 10 in top view, Fig. 2D shows the structure of the unit structure 10 in bottom view, and Fig. 2E shows the structure of the unit structure 10 in side view. The unit structure 10 has a top plate 11 and legs 12.

[0012] The top plate 11 is a member having an upper surface that receives a load. In this embodiment, the top plate 11 has a rectangular shape (particularly, a square shape). The shape of the top plate 11 may be, for example, a hexagon or other polygonal shape, as long as it is a shape suitable for arranging a plurality of unit structures 10 in one or two axial directions. In the case of a rectangular or hexagonal shape, the unit structures 10 can be arranged densely.

[0013] The size of the tabletop 11 is set to be sufficiently smaller than the width of the load applied when a person (not only an adult but also a child) walks on the floor surface, that is, the width of the soles of the feet that come into contact with the floor surface when walking, and the width of the knees that strike the floor surface when falling. In this embodiment, as an example, the length W of one side of the tabletop 11 is set to be １１ Therefore, when not only an adult but also a child falls on the floor, the load acting on the floor surface can be absorbed by the plurality of unit structures 10, thereby preventing injuries such as fractures.

[0014] As will be described later, in order to support the surface material 120 and the like that form the floor surface on the buffer structure 100, the top plate 11 is not limited to a plate shape that spreads over a whole surface, but may also have a frame shape that includes an opening 11a in the center, as long as it can withstand the load applied to the unit structure 10 via the surface material 120 and the like. The shape of the opening 11a may be circular (or elliptical), rectangular (including square), hexagonal, or any other polygonal shape. A plate-shaped top plate 11 has somewhat high rigidity, making it difficult for the legs 12 to tilt relative to the top plate 11, whereas a frame-shaped top plate 11 has moderately low rigidity, making it easy for the legs 12 to tilt and buckle relative to the top plate 11, thereby making it softer and more able to absorb a large impact when the top plate 11 falls over.

[0015] 3A shows a state in which the buffer structures 100 are stacked. Since the top plate 11 includes the openings 11a, the legs 12 of the multiple unit structures 10 included in the buffer structure 100 can be inserted between the legs 12 of the multiple unit structures 10 included in another buffer structure 100 via the openings 11a in the top plate 11 of the multiple unit structures 10, and the legs 12 of the multiple unit structures 10 included in another buffer structure 100 can be inserted between the legs 12 of the multiple unit structures 10 included in yet another buffer structure 100 via the openings 11a in the top plate 11 of the multiple unit structures 10 included in yet another buffer structure 100, allowing multiple buffer structures 100 to be stacked with a small thickness.

[0016] In this embodiment, the top plate 11 is a rectangular (particularly, square) frame body including a rectangular opening 11a in the center. The top plate 11 has a protruding portion 11b that protrudes outward (in the ±X direction and ±Y direction) from the portion where the leg portion 12 described later is connected, in this example, the inner edge that defines the opening 11a. The width w of the protruding portion 11b is １１ｂ (See FIG. 2E) may be set to be equal to or greater than the width of the inner edge portion to which the leg portion 12 is connected. In this embodiment, the width of the inner edge portion is set to, for example, the thickness d of the leg portion 12. １２ The width of the protruding portion 11b is set to approximately 1 mm, which is approximately equal to the frame width w １１ This increases the support surface, making it possible to stably support the upper surface layer 120 and the like.

[0017] In addition, the thickness d of the protruding portion 11b １１ (See FIG. 2E) is the thickness d of the leg 12 １２ In this embodiment, the thickness d of the leg 12 may be equal to or smaller than １２ As a result, the thickness of the protruding portion 11b is relatively small, which reduces the rigidity of the tabletop 11 appropriately, making it easier for the legs 12 to tilt and buckle relative to the tabletop 11, thereby increasing the deformation stroke of the tabletop 11 in the Z-axis direction.

[0018] 3B shows the state in which the buffer structure 100 is rolled up. As described above, the buffer structure 100 is formed integrally by connecting the protruding portions 11b of a plurality of unit structures 10. The rigidity of the top plate 11 is reduced at the points where the protruding portions 11b of adjacent unit structures 10 are connected. Therefore, by arranging the unit structures 10 in a matrix, the buffer structure 100 bends at the connecting points, making it easier to roll up in the direction in which the unit structures 10 are arranged. At this time, by inserting the legs 12 of one unit structure 10 into the openings 11a of the top plate 11 of another unit structure 10, the buffer structure 100 can be rolled up with a small thickness.

[0019] The legs 12 are members that extend in the -Z direction from the underside of the tabletop 11 and support the tabletop 11 on the subfloor S. At least one leg 12 is provided for each of the tabletops 11 of the multiple unit structures 10 that make up the buffer structure 100, and preferably multiple legs 12 are provided for each tabletop 11, with multiple legs 12 being particularly arranged along the periphery of each tabletop 11. If the tabletop 11 is polygonal, the legs 12 are arranged near multiple corners, and if the tabletop 11 is circular, the legs 12 are arranged in at least three or more locations at arbitrary intervals. As a result, when a load is applied to the tabletop 11, the load is distributed to the multiple legs 12, allowing the tabletop 11 to be stably supported.

[0020] Height H of leg 12 １２ can be determined according to the deformation stroke required to absorb the load for one unit structure 10. In this embodiment, as an example, the height H １２ is approximately 9 mm.

[0021] Each leg 12 is inclined toward the center of the top plate 11 (or the unit structure 10) with respect to the underside of the top plate 11. When viewed from the side in the X-axis direction (see FIG. 2E), the inclination angle θ of the leg 12 with respect to the Z-axis is １２ is 6 to 13 degrees, preferably 8 to 11 degrees, and more preferably about 9.5 degrees. The same applies to the inclination angle of the legs 12 in the side view with respect to the Y-axis direction. This makes it easier for the legs 12 to buckle toward the center of the tabletop 11.

[0022] Note that the legs 12 may be perpendicular to the underside of the tabletop 11 if they buckle when subjected to a large impact during a fall. The legs 12 may also be inclined toward the outside of the tabletop 11. In such a case, the inclination angle of the legs 12 may be the same as the inclination angle when the legs 12 are inclined toward the center of the tabletop 11.

[0023] Each leg 12 has a cross-sectional shape that is bent convexly toward one side in the XY plane. The leg 12 may be curved convexly toward one side, and preferably bent convexly toward one side. This makes the transition of the deformation mode of the leg 12 when a load is applied, i.e., the transition from the expansion / contraction mode to the buckling mode or the transition from the buckling mode to the expansion / contraction mode, more distinct. In other words, the leg 12 is hard until the load exceeds a threshold strength, and when the load exceeds the threshold strength, the transition of the characteristic that the leg 12 becomes soft becomes more distinct. Here, the thickness d of the leg 12 is １２ (see FIG. 2B) adjusts the threshold load at which the deformation mode transitions. １２ is approximately 1 mm.

[0024] In this embodiment, since the top plate 11 is rectangular, the four legs 12 are arranged near the four corners of the top plate 11 with their convexly curved outer surfaces facing outward in the radial direction based on the center of the unit structure 10 (or the top plate 11) when viewed from above. That is, the legs 12 arranged near the −X and −Y corners of the top plate 11 are bent outward from the center of the top plate 11, i.e., convexly at 90 degrees in the −X and −Y directions (in an L-shape from the −X direction to the +Y direction), with their inner surfaces flush with the inner surfaces of the −X and −Y corners of the top plate 11, and their upper ends connected to the undersides of the −X and −Y corners of the top plate 11. Furthermore, the legs 12 arranged near the -X and +Y corners of the tabletop 11 are bent outward from the center of the tabletop 11, i.e., bent at 90 degrees in the -X and +Y directions (in an L-shape from the +Y direction to the +X direction), so that their inner surfaces are flush with the inner surfaces of the -X and +Y corners of the tabletop 11 and their upper ends are connected to the underside of the -X and +Y corners of the tabletop 11. Furthermore, the legs 12 arranged near the +X and +Y corners of the tabletop 11 are bent outward from the center of the tabletop 11, i.e., bent at 90 degrees in the +X and +Y directions (in an L-shape from the +X direction to the -Y direction), so that their inner surfaces are flush with the inner surfaces of the +X and +Y corners of the tabletop 11 and their upper ends are connected to the underside of the +X and +Y corners of the tabletop 11. Furthermore, the legs 12 arranged near the +X, -Y corners of the top plate 11 are bent outward from the center of the top plate 11, i.e., bent convexly at 90 degrees in the +X, -Y directions (in an L-shape from the -Y direction to the -X direction), with their inner surfaces flush with the inner surfaces of the +X, -Y corners of the top plate 11 and their upper ends connected to the undersides of the +X, -Y corners of the top plate 11. As a result, the top plate 11 is supported by a plurality of legs 12 (four in this example) arranged along its periphery, and when a load equal to or greater than a threshold load is applied to the top plate 11, the legs 12 buckle radially inward, preventing them from spreading outward and interfering with the legs 12 of adjacent unit structures 10.

[0025] The legs 12 have tips with a shape similar to the convexly bent cross-sectional shape described above. In other words, each leg 12 does not have an end surface parallel to the XY plane connecting the insides of the 90-degree bent tips, nor a bottom surface parallel to the XY plane connecting the tips of the four legs 12. Instead, a space 12c is formed between the tips of the four legs 12, opening in the Z-axis direction. This allows the body (center in the Z-axis direction) of each of the four legs 12 to deform so as to expand by more than 90 degrees in the XY plane (providing an end surface or bottom surface would increase rigidity and make expansion difficult). Furthermore, the entire structure buckles toward the center of the top plate 11, allowing the top plate 11 to be significantly displaced in the Z-axis direction. Furthermore, the unit structures 10 penetrate in the Z-axis direction, improving ventilation.

[0026] This shape of the leg 12 allows the leg 12 to maintain rigidity until buckling despite occupying a small amount of material in the space, and by reducing the amount of material, the deformation stroke in the Z-axis direction can be maximized.

[0027] Each leg 12 has a recess 12a formed in at least a part of an outer corner in the radial direction based on the center of the unit structure 10 (or the top plate 11) when viewed from above. This makes it possible to induce each leg 12 to bend inward in the radial direction, starting from the recess 12a, when a load equal to or greater than a threshold load is applied to the top plate 11 of the unit structure 10.

[0028] The recess 12a is located at the center of the leg 12 in the Z-axis direction. In particular, the recess 12a is formed in a wedge shape extending from the base end (i.e., the upper end connected to the underside of the top plate 11) of the leg 12 to the tip (i.e., the lower end) of the leg 12, with the deepest point at the center of the leg 12. The maximum width w of the recess 12a is １２ａ (See FIG. 2E) is, for example, about 1 mm. This prevents the upper and lower edges of the recess 12a from interfering with each other when the leg 12 is bent, limiting the bending angle, i.e., the deformation stroke of the leg 12 in the Z-axis direction, and allows the entire leg 12 to buckle, maximizing the deformation stroke. The recess 12a may be formed in a concave shape. Alternatively, multiple recesses 12a may be arranged side by side in the Z-axis direction.

[0029] Two adjacent legs 12 of the plurality of legs 12 form a gap 12b between them. The gap 12b is smallest at the upper end side of the two legs 12, and its minimum width w １２ is set to about 2 mm as an example. The upper ends of the plurality of legs 12 may be connected to adjacent legs 12. In such a case, the minimum width w of the gap 12b immediately below the connection point is １２ As a result, when the legs 12 buckle, the air inside the unit structure 10 can easily flow to the outside through the gaps 12b, and the air damper effect is appropriately reduced, making the legs 12 more likely to buckle.

[0030] Furthermore, the shape of the side of the leg 12 is determined so that the gap 12b between two adjacent legs 12 widens in the −Z direction from the underside of the tabletop 11 (or the connecting point of the two adjacent legs 12). When viewed from the side in the X-axis direction, the angle φ of the side of the leg 12 with respect to the Z-axis １２ (See FIG. 2E) is 3 to 10 degrees, preferably 5 to 8 degrees, and more preferably about 6.3 degrees. Therefore, the gap 12b extends from the lower surface or connecting point of the top plate 11 to the lower end in a range of, for example, about 2 to about 4 mm. Note that the length W of one side of the leg 12 is １２ (See FIG. 2E) is approximately 4 mm. As a result, when a load equal to or greater than the threshold load is applied to the tabletop 11 and the tabletop 11 buckles, the two adjacent legs 12 interfere with each other, thereby limiting the deformation stroke of the tabletop 11 in the Z-axis direction.

[0031] 4 shows the structure of the sliding rib 13 of the unit structure 10. The sliding rib 13 is provided on the unit structure 10 located at the outermost position among the plurality of unit structures 10 constituting the buffer structure 100, and is formed so as to extend in the +Z direction from the protruding portion 11b of the top plate 11 on the outer surface of the leg 12 and to be inclined towards the outer surface of the leg 12. As a result, an end surface 13a is formed extending in the +Z direction from the side surface of the protruding portion 11b, and an inclined surface 13b connected to the outer surface of the leg 12 is formed below the end surface 13a. The width w of the sliding rib 13 １３ is set to about 1 mm, for example.

[0032] 5A to 5C show the function of the sliding rib 13. When two buffer structures 100 are installed side by side on the floor substructure S, as shown in Fig. 5A, the end portion (i.e., the protruding portion 11b) of the unit structure 10 located outermost on the right-side buffer structure 100 may rest on the end portion (i.e., the protruding portion 11b) of the left-side buffer structure 100. In this case, the inclined surface 13b of the sliding rib 13 of the right-side unit structure 10 rests on the protruding portion 11b of the left-side unit structure 10.

[0033] Therefore, a load is applied downward (in the direction of the white arrow) to the top plate 11 of the right-side unit structure 10. As a result, the end of the protruding portion 11b of the left-side unit structure 10 slides on the inclined surface 13b of the sliding rib 13 of the right-side unit structure 10, and the right-side unit structure 10 is pushed downward while shifting to the right as shown by the filled-in arrow.

[0034] 5B , the right-side unit structure 10 is positioned in the left-right direction relative to the left-side unit structure 10, and the end face 13a of the sliding rib 13 of the right-side unit structure 10 comes into surface contact with the end face 13a of the sliding rib 13 of the left-side unit structure 10. Furthermore, a load is applied downward (in the direction of the white arrow) to the top plate 11 of the right-side unit structure 10. As a result, the end face 13a of the sliding rib 13 of the right-side unit structure 10 slides over the end face 13a of the sliding rib 13 of the left-side unit structure 10, and the right-side unit structure 10 is pushed further downward as indicated by the filled-in arrow.

[0035] 5C , the right-side unit structure 10 (i.e., the buffer structure 100) is placed next to the left-side buffer structure 100 on the underfloor S. In this way, by utilizing the end faces 13 a and inclined faces 13 b of the multiple buffer structures 100 (unit structures 10), the multiple buffer structures 100 can be positioned laterally and arranged on the underfloor S so that the upper surfaces of the top plates 11 are flush with each other.

[0036] 6A and 6B show the structure of the reinforcing rib 14 of the buffer structure 100 in a side view and a bottom view, respectively. The reinforcing rib 14 may be provided between two adjacent unit structures 10 among the multiple unit structures 10 that make up the buffer structure 100. The reinforcing rib 14 is formed so as to connect the lower surfaces of the protruding portions 11b that connect the two adjacent unit structures 10 to the outer surfaces of the legs 12 of the two unit structures 10 that face each other via the protruding portions 11b in the bottom view. The width d of the reinforcing rib 14 １４ and height h １４ By providing a reinforcing rib 14 between the top plate 11 and the legs 12, the rigidity of the legs 12 can be adjusted.

[0037] The reinforcing ribs 14 may be provided between the outer surfaces of the opposing legs 12 of all unit structures 10, or alternatively, may be provided only between the outer surfaces of the opposing legs 12 of some unit structures 10.

[0038] In order to connect adjacent buffer structures 100 to each other when arranging a plurality of buffer structures 100 on the underfloor S, a joint structure may be provided in the outermost unit structure 10 among the plurality of unit structures 10 that make up the buffer structure 100. A single buffer structure 100 may be provided with a plurality of joint structures.

[0039] 7A and 7B show a perspective view and a side view, respectively, of the joint structure of the buffer structures 100 (unit structures 10). The joint structure includes a claw portion 15 provided on one adjacent buffer structure 100 (unit structure 10a) and a claw receiving portion 16 provided on the other buffer structure 100 (unit structure 10b). Here, a joint structure that connects the +Y end of the unit structure 10a located at the outermost position of one buffer structure 100 with the -Y end of the unit structure 10b located at the outermost position of the other buffer structure 100 is shown as an example, but the joint structure can also be provided on the outer edge (+X edge, -X edge, +Y edge, or -Y edge) of any of the unit structures 10 located at the outermost position of the two buffer structures 100.

[0040] The claw portions 15 are members that engage with claw receiving portions 16 formed on the top plate 11 of the unit structure 10b. The claw portions 15 extend in the +Y direction from the upper ends of the outer surfaces of the top plate 11 of the unit structure 10a and the +Y side legs 12 on the +X and +Y sides, and have grooves 15a extending in the X-axis direction near the tips on the bottom surface and grooves 15b extending in the X-axis direction on the base ends on the top surface, forming an S-shape in side view. Note that the claw portions 15 may also be formed between the top plate 11 of the unit structure 10a and the legs 12 on the -X and +Y sides.

[0041] The claw receiving portion 16 is a member that is locked by the claw portion 15 formed on the top plate 11 of the unit structure 10a. The claw receiving portion 16 is provided on the +X and -Y sides of the unit structure 10b in place of the leg portion 12, and has a step portion 16b, a block body 16d, and locking blocks 16c and 16e. The step portion 16b is formed to protrude from the inner edge of the +X side of the top plate 11 toward the -X side. The block body 16d is formed to extend from the inner edge of the -Y side of the top plate 11 toward the +Y side. The locking block 16c is formed integrally with a part of the top plate 11 on the -Y and +Z sides between the step portion 16b and the block body 16d so as to connect them. The locking block 16e is formed on the +Y and -Z sides between the step portion 16b and the block body 16d so as to connect them. The locking blocks 16c and 16e form an S-shaped space 16a between the step portion 16b and the block body 16d when viewed from the side in the X-axis direction.

[0042] 8A and 8B respectively show a perspective view and a side view of two buffer structures 100 (two unit structures 10a and 10b) connected by a joint structure. First, the claw portion 15 of unit structure 10a is inserted into the space 16a of the claw receiver 16 of unit structure 10b from below the locking block 16c toward above the locking block 16e. Next, the locking block 16e of the claw receiver 16 is fitted into the groove 15a of the claw portion 15, and the locking block 16c of the claw receiver 16 is fitted into the groove 15b of the claw portion 15. Then, the protruding portion 11b on the +Y side of the top plate 11 of unit structure 10a and the protruding portion 11b on the -Y side of the top plate 11 of unit structure 10b are abutted against each other, and the two unit structures 10a and 10b are aligned so that their top plates 11 are flush with each other. As a result, the two unit structures 10a and 10b, i.e., the two buffer structures 100, are connected together.

[0043] One of the buffer structures 100 may include a unit structure 10a provided with the claw portion 15, and a unit structure 10b having the claw receiving portion 16. The other of the buffer structures 100 may include a unit structure 10a provided with the claw portion 15, and a unit structure 10b provided with the claw receiving portion 16. In other words, the buffer structure 100 may include unit structures 10a each provided with one or more claw portions 15 and unit structures 10b having the claw receiving portion 16.

[0044] 9A to 9D show the cushioning principle of the cushioning structure 100 (unit structure 10). One unit structure 10 out of the multiple unit structures 10 that make up the cushioning structure 100 is shown as an example. The upper and lower parts of FIG. 9A show the unit structure 10 in a no-load state as viewed from above and from the side, respectively. The unit structure 10 is installed on a floor substrate S. The top plate 11 of the unit structure 10 is supported by four legs 12 to a height H １２ (See Figure 2E).

[0045] The upper and lower parts of Figure 9B show the unit structure 10 in a contracted state as viewed from above and from the side, respectively. A downward load (in the direction of the white arrows) is applied from the top surface of the top plate 11. However, the load is smaller than a predetermined threshold load. In this case, the four legs 12 supporting the top plate 11 contract slightly in the Z-axis direction, lowering the top plate 11 slightly downward (in the direction of the solid arrows) to absorb the load.

[0046] 9C show the unit structure 10 in a buckled state from a top view and a side view, respectively. Assume that the load (white arrows) applied to the top plate 11 exceeds the threshold load. In this case, the four legs 12 supporting the top plate 11 bend (i.e., buckle) toward the inside of the unit structure 10 (in the direction of the small black arrows) while widening their convexly bent cross sections in the XY plane, causing a large displacement in the Z-axis direction, thereby causing the top plate 11 to drop significantly downward (in the direction of the large black arrow).

[0047] 9D show the unit structure 10 in a collapsed state from a top view and a side view, respectively. Let's assume that the load (white arrows) applied to the top plate 11 becomes even larger. The four legs 12 supporting the top plate 11 completely expand their convexly bent cross sections in the XY plane, further bending and softening toward the inside of the unit structure 10 (in the direction of the small black arrows). They then abut the upper and lower sides of the outer surface and contract in the Z-axis direction, lowering the top plate 11 further downward (in the direction of the large black arrows), thereby absorbing the load.

[0048] In this way, the cushioning structure 100 (unit structure 10) is hard against small loads below the threshold load applied when walking, providing stability when walking, and is soft against large impacts above the threshold load when falling, and can undergo large deformation to absorb the impact.

[0049] 10 shows a cross-sectional structure of a flooring material 200 including the cushioning structure 100 according to this embodiment. The flooring material 200 includes a surface material 120, an intermediate material 110, and the cushioning structure 100.

[0050] The surface material 120 is a layered material whose upper surface forms the floor surface (i.e., the walking surface). The surface material 120 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 120 may also be formed integrally with the intermediate material 110.

[0051] The intermediate material 110 is a layer material that is disposed between the surface material 120 and the buffer structures 100 and that smooths out any unevenness on the upper surface of the buffer structures 100 that are arranged on the floor subfloor S. As an example, the intermediate material 110 may be a foam layer formed using a foam material such as polyurethane. The intermediate material 110 is disposed across at least two buffer structures 100. This distributes a local load applied to the surface material 120 to the multiple buffer structures 100.

[0052] A plurality of cushioning structures 100 are arranged on the floor underlay S, and support the surface materials 120 and the intermediate materials 110. The cushioning structures 100 are configured as described above, and absorb the load applied via the surface materials 120.

[0053] The cushioning structure 100 according to this embodiment can be manufactured by injection molding. Here, the top plate 11 and the legs 12 are molded as a single unit. The cushioning structure 100 is formed using an elastic material such as NR rubber or a thermoplastic elastomer so that the buckled legs 12 return to their upright position when the load is released. As a result, the legs 12 have a rubber hardness of 10 to 100, preferably 50 to 80.

[0054] FIG. 11 shows the cushioning characteristics of the cushioning structure 100 (embodiment). A numerical simulation using the finite element method analyzed the time course of the load (arbitrary units) applied to the femur when a person weighing 40 kg falls from an upright position and strikes the floor (i.e., the upper surface of the surface material 120). As a comparative example, the cushioning characteristics of a carpet are also shown. The carpet used had a low-resilience urethane layer with a thickness of approximately 10 mm and polyester fluff on the upper surface. With the carpet, the load applied to the femur gradually increases, peaks at approximately 0.02 seconds, and then gradually decays. If the load exceeds the fracture strength (dotted line) before reaching its peak, it will result in a fracture of the femur. In contrast, with the cushioning structure 100 according to this embodiment, the load applied to the femur increases rapidly, peaks at 0.12 seconds, remains approximately constant until 0.02 seconds, and then gradually decays. The peak load is smaller than that in the case of carpet, and it is seen that the load does not exceed the fracture strength because the leg 12 buckles before reaching the fracture strength.

[0055] With the flooring material 200 configured as described above, when a load is applied from the upper surface of the top plate 11 to the buffer structure 100, which is arranged with its legs 12 erected on the floor underlay S, the legs 12 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 bend (i.e., buckle) toward the inside of the unit structure 10 while widening their convexly bent cross sections in the XY plane, causing a large displacement and softening, and after the displacement, they abut the upper and lower sides of their outer surfaces and contract in the Z-axis direction to further absorb the load. As a result, the flooring material 200 is hard against small loads applied when walking, providing stability when walking, and soft against large impacts when falling, causing a large displacement to absorb the impact.

[0056] The buffer structure 100 according to this embodiment includes a tabletop 11 having an upper surface that receives a load, and at least one leg 12 that extends in the Z-axis direction from the underside of the tabletop 11 and has a cross-sectional shape that is bent convexly toward one side in the XY plane. When a load is applied to the upper surface of the tabletop 11 of the buffer structure 100, with the leg 12 standing upright on a subfloor S, the leg 12 contracts in the Z-axis direction to absorb the load until the load exceeds a threshold load (expansion / contraction mode). When the load exceeds the threshold load, the leg 12 bends (i.e., buckles) toward the opposite side while widening its cross-section that is bent convexly in the ZY plane, thereby becoming soft and displaced (buckling mode). After the displacement, the leg 12 abuts the upper and lower sides of one side surface and contracts in the Z-axis direction, thereby further absorbing the load.

[0057] The flooring material 200 according to this embodiment includes a surface material 120 and a buffer structure 100 that supports the surface material 120 and is placed on the subfloor S. The buffer structure 100 supports the surface material 120 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.

[0058] The buffer structure 100 according to the present embodiment has been described as including a plurality of unit structures 10 as constituent units, each of which includes a rectangular frame-shaped top plate 11 and four legs 12 provided near each of the four corners of the top plate 11. However, the buffer structure 100 is not limited to this, and can also be described as including a plurality of unit structures 10d (see FIG. 1 ) as constituent units, each of which includes a cross-shaped top plate 11d and four legs 12 provided near each of the four interior corners of the top plate 11d. In such a case, as shown in FIG. 12 , the four legs 12 extend in the −Z direction from the underside of the top plate 11 and have a cross-sectional shape that is bent convexly inward in the radial direction relative to the center of the top plate 11d (the center of the cross) within the XY plane, and are arranged at the four interior corners adjacent to the vicinity of the center of the top plate 11. As a result, the top plate 11d is supported by four legs 12 arranged adjacent to its center and with their convexly curved portions facing each other, thereby providing great rigidity against forces applied in directions within the XY plane.

[0059] In the cushioning structure 100 according to this embodiment, the leg 12 exhibits a hybrid deformation (called the first deformation mode) in which the deformation mode transitions between an expansion / contraction mode for a load less than the threshold load and a buckling mode for a load equal to or greater than the threshold load, but is not limited to this and may exhibit another deformation mode.

[0060] 13A and 13B show the second deformation mode (closed leg mode) of the cushioning structure 100 (unit structure 10). Note that the illustration shows one unit structure 10 out of the multiple unit structures 10 that make up the cushioning structure 100. The unit structure 10 is placed on the floor substrate S as shown in FIG. 9A, and a load is applied in this state.

[0061] The upper and lower parts of Figure 13A show the unit structure 10 in a closed leg state, as viewed from above and from the side, respectively. A downward load (in the direction of the white arrows) is applied from the top surface of the tabletop 11. However, the load is smaller than a predetermined threshold load. The four legs 12 supporting the tabletop 11 tilt at their connection points with the tabletop 11 and deform so that their tips face inward and close. At this time, the four legs 12 slide their tips horizontally (in the direction of the small black arrows) on the subfloor S, lowering the tabletop 11 slightly downward (in the direction of the large black arrows) to absorb the load.

[0062] The upper and lower panels of Figure 13B show the unit structure 10 in its fully closed leg state, as viewed from above and from the side, respectively. Assume that the load (indicated by the white arrows) applied to the tabletop 11 exceeds a threshold load (although the load does not necessarily have to exceed the threshold load). The four legs 12 supporting the tabletop 11 further tilt at their connection points with the tabletop 11 and deform so that their tips face inward and close. As a result, the four legs 12 slide their tips horizontally (in the direction of the small black arrows) on the subfloor S, interfering with each other at the center of the unit structure 10. The four legs 12 then contract in the Z-axis direction, lowering the tabletop 11 further downward (in the direction of the large black arrows) to absorb the load.

[0063] 14A and 14B show the third deformation mode (open leg mode) of the cushioning structure 100 (unit structure 10). Note that the illustration focuses on one unit structure 10 out of the multiple unit structures 10 that make up the cushioning structure 100. The unit structure 10 is placed on the floor substrate S as shown in FIG. 9A, and a load is applied in this state.

[0064] The upper and lower parts of Figure 14A show the unit structure 10 in a spread-leg state, as viewed from above and from the side, respectively. A downward load (in the direction of the white arrows) is applied from the top surface of the tabletop 11. However, the load is smaller than a predetermined threshold load. The four legs 12 supporting the tabletop 11 tilt at their connection points with the tabletop 11 and deform so that their tips open outward. At this time, the four legs 12 slide their tips horizontally (in the direction of the small black arrows) on the subfloor S, lowering the tabletop 11 slightly downward (in the direction of the large black arrows) to absorb the load.

[0065] The upper and lower panels of Figure 14B show top and side views, respectively, of the unit structure 10 in the most open leg position. Assume that the load (white arrows) applied to the tabletop 11 exceeds a threshold load (although the load does not necessarily have to exceed the threshold load). The four legs 12 supporting the tabletop 11 further tilt at their connection points with the tabletop 11 and deform so that their tips open outward. As a result, the tips of the four legs 12 slide horizontally (in the direction of the small black arrows) on the subfloor S, interfering with the tips of the legs 12 between adjacent unit structures 10. The four legs 12 then contract in the Z-axis direction, lowering the tabletop 11 further downward (in the direction of the large black arrows) to absorb the load.

[0066] Each of the multiple unit structures 10 constituting the buffer structure 100 may deform in any one of the first to third deformation modes. That is, one or more unit structures 10 may deform in the first deformation mode, another one or more unit structures 10 may deform in the second deformation mode, and yet another one or more unit structures 10 may deform in the third deformation mode. Also, each of the four legs of one unit structure 10 of the multiple unit structures 10 constituting the buffer structure 100 may deform in any one of the first to third deformation modes. That is, one or more legs 12 of the four legs of one unit structure 10 may deform in the first deformation mode, another one or more legs 12 may deform in the second deformation mode, and yet another one or more legs 12 may deform in the third deformation mode.

[0067] In addition, in the multiple unit structures 10 that make up the buffer structure 100 of this embodiment, a space 12c that opens in the Z-axis direction is formed between the tips of the four legs 12, but in cases where the body of the leg 12 has appropriate rigidity to expand and deform in the XY plane, a bottom surface 17 that connects to the tip of each of the four legs 12 may be provided instead.

[0068] 15A to 15E show the structure of a unit structure 10d2 according to a modified example. The unit structure 10d2 is the smallest structural unit that constitutes the buffer structure 100. Here, FIG. 15A shows the overall structure of the unit structure 10d2 in a perspective view, FIG. 15B shows the internal structure of the unit structure 10d2 in a perspective view with some parts omitted, FIG. 15C shows the structure of the unit structure 10d2 in a top view, FIG. 15D shows the structure of the unit structure 10d2 in a bottom view, and FIG. 15E shows the structure of the unit structure 10d2 in a side view. The unit structure 10d2 has a top plate 11, legs 12, and a bottom surface 17. Here, the top plate 11 and legs 12 are the same as those described above.

[0069] The bottom surface 17 is a plate-like member that is provided between the tips of the four legs 12 and forms the bottom surface of the unit structure 10d2. The bottom surface 17 includes a central portion 17a and four connecting portions 17b.

[0070] The central portion 17a is located at the center of the four legs 12 in top view, and has a size and shape that roughly closes the internal space of the unit structure 10d2. In this example, the central portion 17a has a rectangular shape, and is arranged so that its four corners are adjacent to the tips of the four legs 12, respectively.

[0071] The four connecting portions 17b each connect from a corner of the central portion 17a to the tip of an adjacent leg portion 12. As an example, the connecting portions 17b have a width equal to the width of the tip of the leg portion 12 when viewed in a direction in which the connecting portions 17b extend from the corner of the central portion 17a. As a result, slits 17c that connect to the gaps 12b are formed between two adjacent connecting portions 17b of the four connecting portions 17b.

[0072] The bottom surface 17 has a generally cross shape in top view, with a central portion 17a and four connecting portions 17b. By making the central portion 17a in particular of an appropriate size, it is possible to fix the unit structure 10d2 by adhering it to the subfloor S (see FIG. 10). Furthermore, by providing the bottom surface 17, it is possible to limit the deformation modes of the unit structure 10 to only the expansion / contraction and buckling modes (see FIGS. 9A to 9D) without being affected by friction with the subfloor S.

[0073] 16 shows the structure of the sliding rib 13 in a unit structure 10d2 according to a modified example. The sliding rib 13 is provided on the unit structure 10d2 located outermost among the multiple unit structures 10d2 that make up the buffer structure 100. The structure of the sliding rib 13 is the same as that described above. By utilizing the end faces 13a and inclined faces 13b of the unit structures 10d2, as described above, the multiple buffer structures 100 can be positioned in the lateral direction and can be arranged on the subfloor S so that the upper surfaces of the top plates 11 are flush with each other.

[0074] In the unit structure 10d2 according to the modified example, a reinforcing rib 14 may be provided between two adjacent unit structures 10d2 among the plurality of unit structures 10d2 that make up the buffer structure 100 (see FIGS. 6A and 6B ). This allows the rigidity of the leg portion 12 to be adjusted.

[0075] 17A shows a perspective view of the structure of locking member 25 in unit structure 10d2 according to a modified example. Note that locking member 25 can be provided on the outer edge (+X edge, −X edge, +Y edge, or −Y edge) of any unit structure 10d2 located at the outermost position of buffer structure 100. Locking member 25 includes base 25c, extension 25b, and tip 25a.

[0076] The base 25c is a block-shaped member for fixing the locking member 25 to the unit structure 10d2, and as an example, extends from directly below the center of the protrusion 11b on the -X side of the top plate 11 to the top of the gap 12b between two adjacent legs 12 on the -X side, and is molded integrally with the top plate 11 and the two legs 12.

[0077] The extension 25b is a rectangular columnar member that extends from between the two legs 12, and in this example, since the base 25c is provided between the two legs 12, from the -X face of the base 25c toward the outside of the top plate 11 in the -X direction to support the tip 25a. The width of the extension 25b in the Y-axis direction is the minimum width w of the gap 12b. １２ The length of the extension 25b in the X-axis direction is slightly larger than the frame width of the top plate 11 when viewed from above. The extension 25b is not limited to a rectangular column, but may be a columnar body of any shape, such as a circular column.

[0078] The tip portion 25a is a member that engages with the two legs 12 of another unit structure 10d2, is fixed to the -X end of the extension portion 25b, and has a shape that spreads in the ±Y directions. The width of the tip portion 25a in the Y-axis direction is equal to the minimum width w of the gap 12b. １２ Greater than.

[0079] 17B shows a side view of a unit structure 10d2 according to a modified example connected to a unit structure 10d2 included in another buffer structure 100 by a locking member 25. First, the unit structure 10d2 is rotated 90 degrees in the YZ plane relative to the unit structure 10d2, so that the tip 25a of the locking member 25 faces the Z-axis direction. Next, the tip 25a is inserted in the +Z direction from one side end into the slit 17c of the unit structure 10d2, and the extension 25b is moved to the top of the gap 12b connected to the slit 17c, so that the entire tip 25a is inserted into the internal space of the unit structure 10d2. Finally, the unit structure 10d2 is rotated −90 degrees in the YZ plane, so that the top plate 11 is aligned flush with that of the unit structure 10d2. As a result, the locking members 25 of the unit structure 10d2 are locked to the two legs 12 of the unit structure 10d2, and the unit structure 10d2 is connected to the unit structure 10d2.

[0080] The buffer structure 100 may be configured to include both the unit structure 10 and the unit structure 10d2 according to the modified example. That is, some of the multiple unit structures that make up the buffer structure 100 may be unit structures 10, with the four legs 12 of the unit structure 10 being free, and the remainder may be unit structures 10d2 according to the modified example, with the bottom surface 17 provided between the tips of the four legs 12 of the unit structure 10d2.

[0081] 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.

[0082] It should be noted that the order of execution 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.

[0083] 10, 10a, 10b, 10d, 10d2...unit structure, 11, 11d...top plate, 11a...opening, 11b...projection portion, 12...leg portion, 12a...recess, 12b...gap, 12c...space, 13...sliding rib, 13a...end face, 13b...inclined surface, 14...reinforcing rib, 15...claw portion, 15a, 15b...groove portion, 16...claw receiving portion, 16a...space, 16b...step portion, 16c, 16e...locking block, 16d...block body, 17...bottom surface, 17a...center portion, 17b...connecting portion, 17c...slit, 25...locking member, 25a...tip portion, 25b...extension portion, 25c...base, 100...buffer structure, 110...intermediate material, 120...surface material, 200...floor material, S...floor underlayment.

Claims

1. A shock-absorbing structure that absorbs shock, a top plate having an upper surface that receives a load; At least one leg portion extends in a first direction away from the lower surface of the top plate and has a cross-sectional shape that is bent convexly toward one side in a second direction within a plane that intersects with the first direction, A buffer structure, wherein the at least one leg is inclined toward the opposite side of the second direction relative to the underside of the tabletop and is formed using an elastic material so as to buckle toward the opposite side of the second direction when a load equal to or greater than a threshold load is applied to the tabletop.

2. The cushioning structure according to claim 1 , wherein the at least one leg has a tip end having a shape similar to the cross-sectional shape.

3. The buffer structure according to claim 1 , wherein the at least one leg portion has a cross-sectional shape that is bent convexly toward one side in the second direction.

4. The buffer structure according to claim 1 , wherein the at least one leg portion has a recess formed in at least a part of a corner portion on one side in the second direction.

5. The cushioning structure according to claim 4 , wherein the recess is formed from a base end to a tip end of the at least one leg portion.

6. 2. The cushioning structure of claim 1, wherein the at least one leg includes a plurality of legs arranged along the periphery of the top plate, with a radial direction based on the center of the top plate as the second direction, and an outer side and an inner side with respect to the radial direction as the one side and the opposite side to the one side, respectively.

7. A buffer structure as described in Claim 6, wherein each of the multiple legs has a cross-sectional shape that is convexly bent outward in the radial direction and is inclined inward in the radial direction relative to the underside of the top plate.

8. The cushioning structure according to claim 7 , wherein two adjacent legs of the plurality of legs form a gap therebetween.

9. The buffer structure according to claim 8 , wherein the gap between the two legs widens from the lower surface of the top plate toward the first direction.

10. The cushioning structure according to claim 7 , wherein the top plate has a frame shape including an opening in the center.

11. The top plate has a rectangular shape, The cushioning structure according to claim 7 , wherein the plurality of legs are disposed at corners of the top plate.

12. The cushioning structure according to claim 7 , wherein the top plate includes a protruding portion that protrudes outward from a location where the plurality of legs are connected.

13. The cushioning structure of claim 12 , wherein the thickness of the overhang is equal to or less than the thickness of the plurality of legs.

14. The cushioning structure of claim 12 , wherein at least one of the plurality of legs includes a rib formed between a lower surface and an outer side surface of the overhang.

15. the top plates are arranged in a plurality of directions, the protruding portions of which are connected to one another, in at least one direction of the second direction and a third direction intersecting the first direction and the second direction, and The buffer structure according to claim 12 , wherein the plurality of legs are provided for each of the plurality of top plates.

16. a sliding rib extending in the first direction from the protruding portion of the tabletop positioned at the outermost position among the plurality of tabletops on an outer surface of a leg of a plurality of legs provided on the tabletop that is adjacent to the protruding portion and that is inclined toward the outer surface of the leg that is adjacent to the protruding portion; The buffer structure according to claim 15 , wherein the sliding rib has an end surface extending in the first direction from a side surface of the protruding portion of the top plate.

17. The buffer structure according to claim 15, wherein the top plate has a claw portion that engages with a claw receiving portion of a top plate of another buffer structure and / or a claw receiving portion that is engaged with a claw portion of a top plate of another buffer structure.

18. The cushioning structure according to claim 7 , further comprising a bottom surface connected to the tip of each of the plurality of legs.

19. The buffer structure according to claim 18 , wherein the bottom surface includes a central portion located at the center of the plurality of legs and a plurality of connecting portions that connect the central portion to the tips of the plurality of legs, respectively.

20. The cushioning structure according to claim 18, wherein the top plate has a locking member extending from between two adjacent legs of the plurality of legs toward the outside of the top plate and having a shape with a tip that is wider than the gap between the two legs.

21. 2. The cushioning structure of claim 1, wherein the at least one leg includes a plurality of legs arranged adjacent to each other near the center of the top plate, with a radial direction based on the center of the top plate as the second direction, and the inside and outside with respect to the radial direction as the one side and the opposite side relative to the one side, respectively.

22. A flooring material comprising a surface material and the buffer structure according to claim 1 that is placed on a subfloor and supports the surface material.