Soles and shoes

Abstract

To provide a sole capable of obtaining a high driving force during running.SOLUTION: A sole 110A is provided with a repulsive material 1, and has a bottom surface 110b to be a ground plane 112a, and a top surface 110a. The repulsive material 1 has a three-dimensional shape formed by a wall 10 whose outer shape is defined by a pair of parallel flat surfaces or curve surfaces, and in which buckling may occur when a compressive force is applied along a normal direction of the bottom surface 110b. In the sole 110A, when a load on the sole 110A is gradually increased so that a compressive force is applied to the repulsive material 1 along the normal direction, buckling of the repulsive material 1 starts within the range of 0.05 MPa and 0.55 MPa stress occurring in the repulsive material 1 and within the range of 10% and 60% distortion of the repulsive material 1 in the normal direction.SELECTED DRAWING: Figure 16

Description

[Technical Field]

[0001] This invention relates to a shoe sole equipped with a rebound material and a shoe equipped therewith. [Background technology]

[0002] Conventionally, shoe soles equipped with cushioning material and shoes equipped with such material are known. This cushioning material is equipped in the shoe sole for the purpose of mitigating the impact when landing, and is generally composed of solid or hollow bodies made of resin or rubber.

[0003] For example, U.S. Patent Publication No. 2020 / 0281313 (Patent Document 1) discloses a shoe in which a cushioning material made of a hollow resin body is placed between a high-rigidity plate embedded in the sole of the shoe and an outsole that defines the contact surface of the sole.

[0004] Furthermore, in recent years, shoes have been developed that incorporate lattice or web structures in the sole, thereby enhancing cushioning performance not only in terms of materials but also structurally. An example of a document disclosing a shoe with a sole that incorporates a lattice structure is U.S. Patent Publication No. 2018 / 0049514 (Patent Document 2).

[0005] Furthermore, Japanese Patent Publication No. 2017-527637 (Patent Document 3) describes that three-dimensional objects can be manufactured using three-dimensional additive manufacturing, based on geometric surface structures such as polyhedra with internal cavities or triple-periodic minimal surfaces, with added thickness. It also discloses that by constructing such three-dimensional objects from elastic materials, they can be applied, for example, as cushioning material in shoe soles. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] U.S. Patent Publication No. 2020 / 0281313 [Patent Document 2] U.S. Patent Publication No. 2018 / 0049514 [Patent Document 3] Special Publication No. 2017-527637 [Overview of the project] [Problems that the invention aims to solve]

[0007] This type of cushioning material exhibits its cushioning function when a load is applied (i.e., upon landing). Therefore, conventionally, the development of cushioning materials has focused on maximizing cushioning performance under load.

[0008] On the other hand, cushioning material exhibits a rebound function when the load is removed (i.e., when pushing off). Therefore, if the cushioning material is considered as a rebound material and the rebound performance obtained when the load is removed can be maximized, it becomes possible to obtain high propulsion force while running.

[0009] However, in reality, such studies have rarely been conducted to date, and in particular, shoe soles with enhanced rebound performance, not only in terms of materials but also structurally, and shoes equipped with them, have not been fully put into practical use.

[0010] Therefore, the present invention has been made in view of the above-mentioned problems, and aims to provide a shoe sole and a shoe equipped therewith that can obtain high propulsion force when running by incorporating a rebound material with enhanced rebound performance. [Means for solving the problem]

[0011] This invention The first phase The sole of the shoe, based on this design, is equipped with a rebound material and has a bottom surface that is the contact surface with the ground and a top surface located on the opposite side of the bottom surface. The rebound material has a three-dimensional shape formed by walls whose outer shape is defined by a pair of parallel planes or curved surfaces, and buckling may occur when a compressive force is applied along the direction normal to the bottom surface. The modulus of elasticity of the base material of the above-mentioned rebound material is between 4 MPa and 30 MPa. The present invention described above The first phase In the case of the sole based on the present invention, when a load is gradually increased and applied to the sole so that a compressive force is applied to the cushioning material along the normal direction, the stress generated in the cushioning material is in the range of 0.05 MPa or more and 0.55 MPa or less, and the distortion of the cushioning material in the normal direction is in the range of 10% or more and 60% or less, buckling of the cushioning material starts. A sole based on a second aspect of the present invention is provided with a rebound material and has a bottom surface which is the contact surface and a top surface located on the opposite side of the bottom surface. The sole comprises a forefoot portion which supports the toes and ball of the foot of the wearer, a midfoot portion which supports the arch of the foot of the wearer, and a rearfoot portion which supports the heel of the foot of the wearer. The rebound material has a three-dimensional shape formed by walls whose outer shape is defined by a pair of parallel planes or curved surfaces, and can buckle when a compressive force is applied along the direction normal to the bottom surface. A notch is provided in a part of the forefoot portion and the rebound material is housed in the notch so that the rebound material is located only in the portion of the sole with the notch and spans across the portion that supports the ball of the big toe and the portion that supports the ball of the little toe of the wearer. In the sole of the shoe according to the second aspect of the present invention described above, when a load is gradually increased on the sole so that a compressive force is applied to the rebound material along the normal direction, buckling of the rebound material begins when the stress generated in the rebound material is in the range of 0.05 MPa to 0.55 MPa and the strain of the rebound material in the normal direction is in the range of 10% to 60%.

[0012] The shoe based on the present invention is the above-mentioned present invention The first or second phase comprises a sole based on the present invention and an upper provided above the sole.

Effect of the Invention

[0013] According to the present invention, it is possible to provide a sole capable of obtaining a high driving force during running and a shoe provided with the same.

Brief Description of the Drawings

[0014] [Figure 1] It is a perspective view of a cushioning material having basically the same structure as the cushioning material included in the sole according to the embodiment, and a perspective view of a unit structure constituting the cushioning material. [Figure 2] It is a plan view and a sectional view of the cushioning material shown in FIG. 1. [Figure 3] It is a diagram schematically showing buckling that can occur in the cushioning material shown in FIG. 1. [Figure 4] It is a graph showing the resilience performance of the cushioning material shown in FIG. 1. [Figure 5] It is a graph showing the resilience performance of a general cushioning material. [Figure 6] It is a graph showing the results of measuring the resilience performance of the cushioning materials according to Comparative Examples 1 to 4. [Figure 7] It is a table showing the characteristics of the cushioning materials according to Comparative Examples 1 to 4. [Figure 8] It is a graph showing the results of measuring the resilience performance of the cushioning material according to Example 1. [Figure 9]This table shows the properties of the rebound material related to Examples 1 and 2. [Figure 10] This graph summarizes the properties of the rebound material in Examples 1 and 2 and the cushioning material in Comparative Examples 1 to 4. [Figure 11] This graph shows the results of a simulation of the rebound performance of the rebound material related to Verification Example 1. [Figure 12] This table shows the characteristics of the rebound material related to Verification Example 1. [Figure 13] This graph shows the simulation results of the rebound performance of the rebound materials related to verification examples 2 to 6. [Figure 14] This table shows the characteristics of the rebound material related to verification examples 2 through 6. [Figure 15] This is a perspective view of the sole and shoe according to an embodiment. [Figure 16] Figure 15 is a side view of the sole of a shoe, seen from the outer side of the foot. [Figure 17] Figure 15 is a schematic plan view of the sole of a shoe. [Figure 18] Figure 15 is an exploded perspective view of the sole of a shoe. [Figure 19] This is a schematic plan view of the sole of a shoe according to the first modified example. [Figure 20] This is a schematic plan view of the sole of a shoe according to the second modified example. [Figure 21] This is a schematic plan view of the sole of a shoe according to the third modified example. [Figure 22] This is a schematic side view of the sole of the shoe according to the fourth modified example, as seen from the outer side of the foot. [Figure 23] This is a schematic side view of the sole of the fifth modified shoe, as seen from the outer side of the foot. [Figure 24] This is a schematic side view of the sole of the sixth modified shoe, as seen from the outer side of the foot. [Figure 25] This is a schematic side view of the sole of the seventh modified example, as seen from the outer side of the foot. [Figure 26] This is a perspective view of a rebound material having a structure similar to that of a shoe sole according to an embodiment, and a perspective view of a unit structure constituting the rebound material. [Figure 27]Figure 26 shows a plan view and a cross-sectional view of the rebound material. [Figure 28] This graph shows the results of a simulation of the rebound performance of the rebound material related to Verification Example 7. [Figure 29] This table shows the characteristics of the rebound material related to Verification Example 7. [Figure 30] This is a schematic side view of the sole of the shoe according to the eighth modified example, as seen from the outer side of the foot. [Figure 31] Figure 30 is a schematic bottom view of the outsole attached to the sole of the shoe. [Figure 32] This is a schematic side view of the sole of the ninth modified shoe, as seen from the outer side of the foot. [Figure 33] Figure 32 is a schematic bottom view of the insole provided in the sole of the shoe. [Modes for carrying out the invention]

[0015] Embodiments of the present invention will be described in detail below with reference to the drawings. In the embodiments described below, the same or common parts are denoted by the same reference numerals in the drawings, and their descriptions will not be repeated.

[0016] Figure 1(A) is a perspective view of a rebound material having a structure basically the same as the rebound material provided in the sole according to the embodiment, and Figure 1(B) is a perspective view of the unit structure constituting the rebound material. Figure 2(A) is a plan view of the rebound material shown in Figure 1(A) when viewed along the direction of arrow IIA shown in Figure 1(A), and Figures 2(B) and 2(C) are cross-sectional views along the lines IIB-IIB and IIC-IIC shown in Figure 2(A), respectively. First, before describing the sole according to this embodiment and the shoe equipped therewith, the structure of the rebound material 1A having a structure similar to the rebound material provided in the sole will be described with reference to Figures 1(A), 1(B), 2(A), 2(B), and 2(C).

[0017] As shown in Figures 1(A) and 2(A) to 2(C), the rebound material 1A includes a three-dimensional structure S having a plurality of unit structures U. Each of the plurality of unit structures U has a three-dimensional shape formed by walls 10 whose outer shape is defined by a pair of parallel planes (see Figure 1(B)), and thus the three-dimensional structure S also has a three-dimensional shape formed by walls 10 whose outer shape is defined by a pair of parallel planes.

[0018] The unit structure U has a structure based on a geometric planar structural unit with added thickness. More specifically, the unit structure U is constructed by dividing a structural unit consisting of multiple planes arranged intersectingly so as to have a cavity inside, in one of its three orthogonal axis directions, into two, and then adding thickness to each of these two divisions.

[0019] In the unit structure U shown in Figure 1(B), the aforementioned surface structure is a Kelvin structure, and the unit structure U is composed of a Kelvin structure unit that has been divided into two in the height direction (Z-axis direction shown in the figure) among the three orthogonal axes, and then further thickened.

[0020] More specifically, the unit structure U includes one upper wall section 11, four divided lower wall sections 12', and four vertical wall sections 13 that individually connect these upper wall section 11 and lower wall sections 12'. Each of the vertical wall sections 13 extends so as to intersect with the upper wall section 11 and lower wall sections 12', and connects with adjacent vertical wall sections 13 at their lateral ends. As a result, the four vertical wall sections 13 as a whole form an annular shape. Each of these upper wall section 11, lower wall section 12', and vertical wall sections 13 has a flat plate shape.

[0021] The four divided lower wall sections 12' are integrated by becoming continuous with the lower wall sections 12' included in other unit structures U located adjacent to the unit structure U containing it. As a result, in the three-dimensional structure S, the lower wall sections 12' included in each of these four adjacent unit structures U are continuous with each other, forming a single lower wall section 12 having substantially the same shape as the single upper wall section 11 described above (see Figure 2(A), etc.).

[0022] The rebound material 1A according to this embodiment is designed to exhibit a rebound function in the height direction as described above. Therefore, as shown in Figures 1(A) and 2(A) to 2(C), the multiple unit structures U are arranged regularly and continuously in repeated patterns along the width direction (X direction in the figures) and depth direction (Y direction in the figures) of the three orthogonal axes. As a result, when viewed from above, the three-dimensional structure S has a structure in which upward-convex and downward-convex portions are arranged alternately. Note that in Figures 1(A) and 2(A) to 2(C), three adjacent unit structures U in the width direction and depth direction are shown separately.

[0023] In this embodiment, we will describe a rebound material 1A that has a large number of unit structures U in the width direction and depth direction, but the number of repetitions of the unit structures U in the width direction and depth direction is not particularly limited. That is, the rebound material may be composed of two or more unit structures U arranged along only one of the width direction and depth direction, or it may be a rebound material consisting of only one unit structure U.

[0024] The method for manufacturing the rebound material 1A is not particularly limited, but it can be manufactured by molding using a mold, such as injection molding, casting, or sheet molding, or by fabrication using a three-dimensional additive manufacturing device. In particular, since the shape of the rebound material 1A described above is relatively simple, it can be easily manufactured by molding using a mold, eliminating the need for fabrication using a three-dimensional additive manufacturing device or molding using complex molds, thus enabling a significant reduction in manufacturing costs. Furthermore, by manufacturing the rebound material 1A by molding using a mold, it becomes possible to manufacture the rebound material 1A using material types that cannot be manufactured by fabrication using a three-dimensional additive manufacturing device, thus increasing the freedom of material selection and enabling the realization of rebound materials with higher rebound performance.

[0025] The material of the rebound material 1A can be basically any material as long as it has a suitable elastic force, but it is preferably a resin material or a rubber material. More specifically, when the rebound material 1A is made of resin, it can be, for example, polyolefin resin, ethylene-vinyl acetate copolymer (EVA), polyamide thermoplastic elastomer (TPA, TPAE), thermoplastic polyurethane (TPU), or polyester thermoplastic elastomer (TPEE). 1A If it is made of rubber, for example, butadiene rubber can be used.

[0026] The rebound material 1A can also be composed of a polymer composition. In that case, examples of polymers to be included in the polymer composition include olefin polymers such as olefin elastomers and olefin resins. Examples of olefin polymers include polyethylene (e.g., linear low-density polyethylene (LLDPE), high-density polyethylene (HDPE), etc.), polypropylene, ethylene-propylene copolymer, propylene-1-hexene copolymer, propylene-4-methyl-1-pentene copolymer, propylene-1-butene copolymer, ethylene-1-hexene copolymer, ethylene-4-methyl-pentene copolymer, ethylene-1-butene copolymer, 1-butene-1-hexene copolymer, 1-butene-4-methyl-pentene, ethylene-methacrylic acid copolymer, ethylene-methyl methacrylate copolymer, ethylene-methacrylate copolymer Examples include ethyl lylate copolymer, ethylene-butyl methacrylate copolymer, ethylene-methyl acrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-butyl acrylate copolymer, propylene-methacrylic acid copolymer, propylene-methyl methacrylate copolymer, propylene-ethyl methacrylate copolymer, propylene-butyl methacrylate copolymer, propylene-methyl acrylate copolymer, propylene-ethyl acrylate copolymer, propylene-butyl acrylate copolymer, ethylene-vinyl acetate copolymer (EVA), and polyolefins of propylene-vinyl acetate copolymer.

[0027] Furthermore, the polymer may be an amide polymer such as an amide elastomer or an amide resin. Examples of amide polymers include polyamide 6, polyamide 11, polyamide 12, polyamide 66, and polyamide 610.

[0028] Furthermore, the polymer may be an ester-based polymer such as an ester-based elastomer or an ester-based resin. Examples of ester-based polymers include polyethylene terephthalate and polybutylene terephthalate.

[0029] Furthermore, the above polymer may be a urethane-based polymer such as a urethane elastomer or a urethane resin. Examples of urethane-based polymers include polyester polyurethane and polyether polyurethane.

[0030] Furthermore, the above polymer may be a styrene-based polymer such as a styrene elastomer or a styrene resin. Examples of styrene elastomers include styrene-ethylene-butylene copolymer (SEB), styrene-butadiene-styrene copolymer (SBS), hydrogenated SBS (styrene-ethylene-butylene-styrene copolymer (SEBS)), styrene-isoprene-styrene copolymer (SIS), hydrogenated SIS (styrene-ethylene-propylene-styrene copolymer (SEPS)), styrene-isobutylene-styrene copolymer (SIBS), styrene-butadiene-styrene-butadiene (SBSB), and styrene-butadiene-styrene-butadiene-styrene (SBSBS). Examples of styrene resins include polystyrene, acrylonitrile styrene resin (AS), and acrylonitrile butadiene styrene resin (ABS).

[0031] Furthermore, the above polymer may be, for example, an acrylic polymer such as polymethyl methacrylate, a urethane acrylic polymer, a polyester acrylic polymer, a polyether acrylic polymer, a polycarbonate acrylic polymer, an epoxy acrylic polymer, a conjugated diene polymer acrylic polymer and its hydrogenated derivatives, a urethane methacrylic polymer, a polyester methacrylic polymer, a polyether methacrylic polymer, a polycarbonate methacrylic polymer, an epoxy methacrylic polymer, a conjugated diene polymer methacrylic polymer and its hydrogenated derivatives, a polyvinyl chloride resin, a silicone elastomer, butadiene rubber (BR), isoprene rubber (IR), chloroprene rubber (CR), natural rubber (NR), styrene-butadiene rubber (SBR), acrylonitrile-butadiene rubber (NBR), butyl rubber (IIR), etc.

[0032] Here, when selecting the material for the rebound material 1A, it is preferable to pay attention to the loss tangent, generally referred to as tanδ, and it is preferable to select a material in which the tanδ at 25[°C] is less than 0.15, preferably less than 0.10, and even more preferably less than 0.05.

[0033] This tanδ is used as an indicator of energy loss associated with material deformation. By using a base material with a small tanδ value, it is possible to suppress energy loss within the base material during compressive deformation, and higher rebound performance can be expected. Dynamic viscoelasticity measurement can be used to measure tanδ.

[0034] Figures 3(A) and 3(B) schematically represent the buckling that may occur in the rebound material shown in Figure 1(A). Next, the buckling that may occur in the rebound material 1A will be explained with reference to Figures 3(A) and 3(B). Note that the cross-section of the rebound material 1A shown in Figure 3(A) is along the line IIIA-IIIA shown in Figure 2(A), and this is also true in Figure 3(B).

[0035] As shown in Figure 3(A), for example, if the rebound material 1A is sandwiched in the height direction (Z-axis direction shown in the figure) between a pair of highly rigid flat plate-shaped upper member 21 and lower member 22, and the upper member 21 is gradually pressed toward the lower member 22 (i.e., toward the direction of arrow AR shown in Figure 3(B)), a load will be gradually applied to the rebound material 1A along the height direction, and consequently, the rebound material 1A will undergo compressive deformation as shown in Figure 3(B). At that time, due to its structure, deformation will occur in the vertical wall portion 13 of the rebound material 1A, and buckling will occur in the vertical wall portion 13 when a load above a certain level is applied.

[0036] On the other hand, when this pressure is released, the load applied to the rebound material 1A along the height direction decreases and disappears, and consequently, the compressive deformation that had occurred in the rebound material 1A is released, and the rebound material 1A returns to its original shape. At this time, the buckling that had occurred in the rebound material 1A is also eliminated.

[0037] When this compressive deformation is released, the elastic restoring force of the rebound material 1A applies a repulsive force to the upper member 21 and the lower member 22 in a direction that moves them away from each other. This repulsive force applied to the upper member 21 and the lower member 22 determines the rebound performance of the rebound material 1A.

[0038] Figure 4 is a graph showing the rebound performance of the rebound material shown in Figure 1, and Figure 5 is a graph showing the rebound performance of a general cushioning material. The graphs shown in Figures 4 and 5 show the rebound performance of the rebound material (cushioning material). Occurred This is what is known as a stress-strain curve, which shows the correlation between stress and strain by plotting stress on the vertical axis and the strain of the rebound material (cushioning material) on the horizontal axis.

[0039] As described above, due to its structure, rebound material 1A experiences buckling during the process in which a load is applied and gradually increases (hereinafter referred to as the "loading process"). On the other hand, as described above, due to its structure, rebound material 1A experiences buckling during the process in which the applied load gradually decreases (hereinafter referred to as the "unloading process"). This compressive deformation of rebound material 1A accompanied by buckling manifests itself in the stress-strain curve as a characteristic curve as shown below.

[0040] In other words, as shown in Figure 4, in the initial stage of the loading process, Distortion ε As the number increases stress σ It also increases, and consequently, the stress-strain curve rises. On the other hand, in the intermediate stage of the loading process, Distortion ε Due to the increase stress σ It remains almost unchanged, and consequently, the stress-strain curve extends laterally to the right. And in the final stage of the loading process, Distortion ε As the number increases stress σ As this increases, the stress-strain curve rises again.

[0041] In contrast, in the initial stages of the unloading process, Distortion εAs the number decreases stress σ It also decreases, and consequently, the stress-strain curve slopes downward to the left. On the other hand, in the intermediate stage of the unloading process, Distortion ε Due to the decrease stress σ It remains almost unchanged, and consequently, the stress-strain curve extends laterally to the left. And in the final stage of the unloading process, Distortion ε As the number decreases stress σ As a result, the stress-strain curve also decreases, and consequently, it begins to slope downwards again.

[0042] On the other hand, in typical cushioning materials, buckling does not occur during the loading process due to their structure, and therefore the compressive deformation of such cushioning material appears in the stress-strain curve as a characteristic curve as shown below.

[0043] In other words, as shown in Figure 5, from the initial stage to the final stage of the loading process, Distortion ε As the number increases stress σ This also constantly increases, and consequently, the stress-strain curve slopes upward.

[0044] In contrast, from the initial to the final stage of the unloading process, Distortion ε As the number decreases stress σ It also constantly decreases, and consequently, the stress-strain curve slopes downward to the left.

[0045] It is known that there is a certain degree of correlation between the stress-strain curve during the loading process and the stress-strain curve during the unloading process, regardless of whether buckling occurs or not. Specifically, the stress-strain curve during the unloading process roughly matches the stress-strain curve during the loading process, scaled up by approximately 0.7 to 0.9 times in the vertical direction.

[0046] Here, there is an index called Normalized AER (Absolute Energy Return) that represents the superiority or inferiority of rebound performance. This Normalized AER is represented by the area enclosed between the stress-strain curve during the unloading process and the horizontal axis (the area of ​​the shaded portion in the graphs shown in Figures 4 and 5), and the Normalized AER is wre Therefore, it can be expressed by the following equation (1). Note that ε max This is when the stress σ during the unloading process is at its maximum (i.e., the σ shown in Figures 4 and 5). max εmin refers to the strain when the stress σ during the unloading process is at its minimum (i.e., σ=0).

[0047]

number

[0048] The higher the value of this standardized AER, the greater the rebound force obtained. Therefore, if a rebound material can be configured to have a high standardized AER, applying it to the sole of a shoe can increase the propulsive force during running.

[0049] In this regard, the aforementioned rebound material 1A experiences buckling during compressive deformation, and its stress-strain curve is as follows: distortion Due to the decrease stress Because it has a region in the intermediate stage of the unloading process where it hardly changes, if this buckling can be configured to begin at a predetermined magnitude of stress and strain, a greater rebound force can be obtained compared to general cushioning materials.

[0050] Although the standardized AER is calculated from the stress-strain curve during the unloading process, as mentioned above, there is a certain degree of correlation between the stress-strain curve during the loading process and the stress-strain curve during the unloading process. Therefore, if the stress and strain at the start of buckling can be adjusted as described above, it becomes possible to obtain a high rebound force.

[0051] Here, when running, the soles of the shoes OccurThe maximum stress varies depending on the wearer's weight, build, running style, and road surface conditions, but is generally around 0.05 MPa to 0.55 MPa (especially for marathon use, around 0.05 MPa to 0.25 MPa, and for sprint use, around 0.25 MPa to 0.55 MPa), and more specifically, around 0.15 MPa to 0.4 MPa (especially for marathon use, around 0.15 MPa to 0.25 MPa, and for sprint use, around 0.25 MPa to 0.4 MPa). Therefore, the rebound material 1A described above must begin buckling within these stress ranges. For convenience, the former stress range will be referred to as the "required stress range" below.

[0052] In other words, for rebound materials where buckling begins at a stress lower than the required stress range, the above-mentioned normalized AER cannot be expected to be sufficiently large. Conversely, for rebound materials where buckling begins at a stress higher than the required stress range, buckling does not occur during running in the first place, and therefore the above-mentioned normalized AER cannot be expected to be sufficiently large.

[0053] On the other hand, the distortion that occurs in the rebound material during running varies depending not only on the wearer's weight, body shape, running style, and road surface conditions, but also on the shape and material of the rebound material. However, considering that if the distortion is too small, almost no cushioning performance can be obtained, and if the distortion is too large, the sole of the shoe will sink too much, it is preferable that the distortion is approximately 10% to 60%, and even more preferably approximately 10% to 40%.

[0054] Therefore, it is necessary that the rebound material 1A described above begins to buckle within this strain range. For convenience, the former strain range will be referred to as the "required strain range" below.

[0055] Based on these considerations, the inventors conducted the following verification tests 1 to 4 to verify whether it is possible to realize a rebound material that can maximize rebound performance during running when incorporated into the sole of a shoe. Verification tests 1 to 4 will be explained in order below. For convenience, the point at which buckling begins during the loading process will be referred to as the "buckling initiation point" below.

[0056] <Verification Test 1> In Verification Test 1, several cushioning materials commonly used in shoe soles were prepared, and their rebound performance was measured. A total of four types of cushioning materials were prepared (Comparative Examples 1 to 4), and their stress-strain curves were obtained using a Shimadzu Autograph AGX-50kN measuring device. The test conditions were set to a compression rate of 1 [% / s] and a maximum pressure of 0.25 [MPa].

[0057] Figure 6 is a graph showing the results of measuring the rebound performance of the cushioning materials related to Comparative Examples 1 to 4, and Figure 7 is a table showing the characteristics of the cushioning materials related to Comparative Examples 1 to 4.

[0058] As shown in Figure 6, the stress-strain curves of all the cushioning materials in Comparative Examples 1 to 4 were similar to the stress-strain curve of the general cushioning material described above (see Figure 5). In particular, the cushioning materials in Comparative Examples 1, 3, and 4 exhibited the same characteristics as the stress-strain curve of the rebound material 1A described above. distortion Due to the increase stress The loading process does not have a region where it hardly changes, and consequently, distortion Due to the decrease stress The unloading process also lacked a region where the variable remained largely unchanged.

[0059] On the other hand, in the cushioning material relating to Comparative Example 2, distortion Due to the increase stress The loading process has a small region where it hardly changes, and consequently, distortion Due to the decrease stressThere is a small region in the unloading process where the stress remains almost unchanged. However, as will be described later, the buckling initiation point of the cushioning material in Comparative Example 2 was outside both the required stress range and the required strain range.

[0060] Here, as shown in Figure 7, the standardized AER of the cushioning material for Comparative Examples 1 to 4 is a maximum of 0.045 [J / cm²]. 3 ], minimum 0.031 [J / cm 3 The energy return rate was 93.4% at its maximum and 74.1% at its minimum. The energy return rate is the ratio of the area enclosed between the stress-strain curve and the horizontal axis during the loading process to the area enclosed between the stress-strain curve and the horizontal axis during the unloading process (i.e., the normalized AER).

[0061] <Verification Test 2> In Verification Test 2, multiple rebound materials having a structure similar to the rebound material 1A described above were manufactured by injection molding using a mold, and the rebound performance of these rebound materials was actually measured. A total of two types of rebound materials were manufactured, for Examples 1 and 2, and their stress-strain curves were obtained using a Shimadzu Autograph AGX-50kN as the measuring device. Here, the only difference between these two types of rebound materials is the thickness of the wall 10 that forms each of them (see Figure 1(A), etc.), and consequently their specific gravities also differ (see Figure 9). The test conditions were set with a compression speed of 1 [% / s] and a maximum pressure of 0.25 [MPa].

[0062] Figure 8 is a graph showing the results of measuring the rebound performance of the rebound material according to Example 1, and Figure 9 is a table showing the characteristics of the rebound materials according to Examples 1 and 2. Here, in Figures 8 and 9, for comparison, the results of Comparative Example 2, which was confirmed to have the highest rebound force in the aforementioned Verification Test 1, are also included.

[0063] As shown in Figure 8, the stress-strain curve of the rebound material according to Example 1 was similar to the stress-strain curve of the rebound material 1A described above (see Figure 4). That is, the rebound material according to Example 1 has the same stress-strain curve as the rebound material 1A described above. distortion Due to the increase stress The loading process has a region where it hardly changes, and consequently, distortion Due to the decrease stress The unloading process had a region where the stress remained almost unchanged. Although the stress-strain curve of the rebound material in Example 2 is omitted for illustrative purposes, similar results were confirmed for Example 2 as well.

[0064] Here, as shown in Figure 9, the standardized AER of the rebound material according to Example 1 is 0.054 [J / cm²]. 3 The energy return rate was 86.1%. The standardized AER of the rebound material in Example 2 was 0.047 J / cm². 3 The energy conversion rate was 80.9%.

[0065] The standardized AER of the rebound material in Examples 1 and 2 both exceeded that of the standardized AER of the cushioning material in Comparative Example 2, confirming that high rebound performance can be obtained by using the rebound material 1A with the above-described configuration.

[0066] Figure 10 is a graph summarizing the characteristics of the rebound materials for Examples 1 and 2 and Comparative Examples 1 to 4. Specifically, the graph in Figure 10 plots the specific gravity and normalized AER of the rebound materials for Examples 1 and 2 and Comparative Examples 1 to 4 on the graph, with the normalized AER on the vertical axis and the specific gravity on the horizontal axis.

[0067] As shown in Figure 10, while the cushioning materials of Comparative Examples 1, 3, and 4 are all suitable for application to shoe soles due to their low specific gravity and lighter weight, they are inferior for applications where high rebound force is required because they do not provide the high rebound force described above. Similarly, while the cushioning material of Comparative Example 2 is suitable for application to shoe soles where high rebound force is required because it provides a relatively high rebound force as described above, it is inferior because its high specific gravity leads to an increase in the weight of the shoe sole.

[0068] In this regard, the rebound materials of Examples 1 and 2, as described above, both provide a higher rebound force than the cushioning material of Comparative Example 2, making them suitable for application to shoe soles where increased rebound force is desired. Furthermore, they have a specific gravity lower than that of the cushioning material of Comparative Example 2, which also makes them suitable for application to shoe soles.

[0069] Furthermore, the rebound material according to Example 1 is expected to show an improvement of approximately 18% in rebound force and an improvement of approximately 17% in weight reduction compared to the cushioning material according to Comparative Example 2.

[0070] <Verification Test 3> In Verification Test 3, a simulation model corresponding to the rebound material of Example 1 described above was created as Verification Example 1. By performing structural analysis on this model using the finite element method (FEM), the stress-strain curve of the rebound material of Verification Example 1, which consists of the simulation model, was calculated, and its agreement with the stress-strain curve actually measured using the rebound material of Example 1 was confirmed.

[0071] Figure 11 is a graph showing the simulation results of the rebound performance of the rebound material related to Verification Example 1, and Figure 12 is a table showing the characteristics of the rebound material related to Verification Example 1. Here, in Figures 11 and 12, for comparison, the results of Comparative Example 2, which was confirmed to have the highest rebound force in the aforementioned Verification Test 1, are also included.

[0072] As shown in Figure 11, the stress-strain curve of the rebound material in Verification Example 1 was similar to the stress-strain curve of the rebound material 1A described above (see Figure 4). That is, the rebound material in Verification Example 1 has the same characteristics as the stress-strain curve of the rebound material 1A described above. distortion Due to the increase stress The loading process has a region where it hardly changes, and consequently, distortion Due to the decrease stress The unloading process had a region where it hardly changed.

[0073] Here, as shown in Figure 12, the standardized AER of the rebound material for Verification Example 1 is 0.054 [J / cm²], assuming an energy return rate of 80%. 3 The result was as follows: The standardized AER of the rebound material in this Verification Example 1 matches the standardized AER of the rebound material in the above-described Example 1, and it was confirmed that the simulation method performed in Verification Test 3 is generally a valid method for predicting the standardized AER.

[0074] Furthermore, as shown in Figures 11 and 12, the buckling initiation point was calculated from the stress-strain curve of the rebound material in Verification Example 1, and from the stress-strain curve of the rebound material in Comparative Example 2. The buckling initiation point was calculated using the following method.

[0075] First, the tangential modulus of elasticity at each point is calculated by differentiating the stress σ with respect to the strain ε based on the stress-strain curve. Then, the tangential modulus of elasticity when the strain ε is 1% is taken as the initial modulus, and the point at which the tangential modulus of elasticity is first obtained to be less than or equal to half of this initial modulus during the loading process is defined as the buckling initiation point. In addition, from the viewpoint of reducing errors, various filtering methods may be applied as needed when calculating the buckling initiation point. Furthermore, the same method can be used when calculating the buckling initiation point from the stress-strain curve obtained by measuring the rebound material (cushioning material) that has actually been manufactured.

[0076] As a result, it was calculated that the buckling start point of the cushioning material according to Comparative Example 2 was at the point where the stress σ was 0.04 [MPa] and the strain ε was 2.5 [%], and the buckling start point of the rebounding material according to Verification Example 1 was calculated to be at the point where the stress σ was 0.125 [MPa] and the strain ε was 19 [%]. That is, as described above, the buckling start point of the cushioning material according to Comparative Example 2 is outside both the required stress range and the required strain range, whereas it was confirmed that the buckling start point of the rebounding material according to Verification Example 1 is within both the required stress range and the required strain range.

[0077] <Verification Test 4> In Verification Test 4, a plurality of simulation models of the rebounding material having the same structure as the above-described rebounding material 1A were created, and by performing a structural analysis using the above-described finite element method (FEM), the stress-strain curve, normalized AER, and buckling start point, etc. of the rebounding material composed of these simulation models were calculated. Here, there are five types of rebounding materials composed of the created simulation models in total from Verification Example 2 to 6, and each rebounding material differs only in its base material elastic modulus.

[0078] FIG. 13 is a graph showing the results of simulating the rebounding performance of the rebounding materials according to Verification Examples 2 to 6, and FIG. 14 is a table showing the characteristics of the rebounding materials according to Verification Examples 2 to 6. When calculating the normalized AER of the rebounding materials according to these Verification Examples 2 to 6, as described in the table of FIG. 14, considering the application of the rebounding material to the shoe sole, the calculation is performed assuming that the pressurization is stopped when the maximum pressure (i.e., σ max ) reaches 0.55 [MPa] and then the load is removed.

[0079] As shown in FIGS. 13 and 14, the stress-strain curves of the rebounding materials according to Verification Examples 2 to 6 were in accordance with the stress-strain curve of the above-described rebounding material 1A (see FIG. 4). That is, the rebounding materials according to Verification Examples 2 to 6 have, in the loading process, a region where distortion hardly changes even with the increase of stress and accordingly, distortion Due to the decrease stress The unloading process had a region where it hardly changed.

[0080] However, in the case of the rebound material in Verification Example 2, which has a low modulus of elasticity of the base material, although the strain ε at the buckling initiation point is 19 [%], the stress σ at the same buckling initiation point is 0.016 [MPa]. As a result, the buckling initiation point does not fall within the required stress range mentioned above, and therefore its normalized AER is 0.035 [J / cm]. 3 It was found that when this material is applied to the sole of a shoe, sufficient rebound force cannot be obtained.

[0081] Furthermore, in the case of the rebound material related to Verification Example 6, which has a large modulus of elasticity of the base material, although the strain ε at the buckling initiation point is 19%, the stress σ at the buckling initiation point is 0.820 Because the stress is [MPa], the buckling initiation point does not fall within the required stress range mentioned above, and therefore its normalized AER is 0.027 [J / cm]. 3 It was found that when this material is applied to the sole of a shoe, sufficient rebound force cannot be obtained.

[0082] On the other hand, for the rebound materials in Verification Examples 3 to 5, where the modulus of the base material is between that of the rebound material in Verification Example 2 and that of the rebound material in Verification Example 6, the strain ε at the buckling initiation point is 19%. a Furthermore, since the stress σ at the buckling initiation points is 0.066 [MPa], 0.197 [MPa], and 0.492 [MPa] respectively, the buckling initiation points fall within both the required strain range and the required stress range mentioned above. Consequently, their normalized AERs are 0.068 [J / cm]. 3 ], 0.083[J / cm 3 ], 0.155[J / cm 3 It was confirmed that applying these to shoe soles yields high rebound force.

[0083] <Summary of Verification Tests 1 through 4> Based on the results of verification tests 1 to 4 described above, it is understood that an unprecedentedly high rebound force can be obtained by providing a rebound material having a three-dimensional shape formed by walls whose outer shape is defined by a pair of parallel planes, such that buckling can occur when a compressive force is applied, and by configuring the rebound material so that buckling begins in the aforementioned required strain range and required stress range when the load applied to the rebound material is gradually increased.

[0084] For ease of understanding, the graph in Figure 13 shows the required strain range and required stress range in darker colors. Therefore, by designing the rebound material so that buckling begins within these dark-colored ranges, a high rebound force can be obtained. Applying this to shoe soles results in shoe soles and shoes that provide high propulsion during running.

[0085] Here, the rebound material 1A described above was composed of a unit structure U which was made by dividing a Kelvin structure structural unit in the height direction into two and then adding thickness to each. However, other planar structural units may be used instead of the Kelvin structure structural unit.

[0086] For example, in the case of a rebound material having a three-dimensional shape formed by walls whose outer shape is defined by a pair of parallel planes, similar to the rebound material 1A described above, structural units such as octet structures, cubic structures, and cubic-octet structures can be used in addition to the Kelvin structure.

[0087] These planar structural units consist of multiple planes arranged intersecting each other, each containing a cavity inside. By dividing these units in one of the three orthogonal axis directions and then adding thickness to each, a rebound material can be constructed that provides high rebound force.

[0088] <Shoe soles and shoes according to embodiments, and shoe soles and shoes according to the first to seventh modified examples> (Embodiment) Figure 15 is a perspective view of the sole and shoe according to this embodiment, and Figure 16 is a side view of the sole shown in Figure 15 as seen from the outer foot side. Furthermore, Figure 17 is a schematic plan view of the sole shown in Figure 15, and Figure 18 is an exploded perspective view of the sole. The sole 110A according to this embodiment and the shoe 100 equipped therewith will be described below with reference to Figures 15 to 18.

[0089] As shown in Figure 15, the shoe 100 comprises a sole 110A and an upper 120. The sole 110A is a component that covers the sole of the foot and has a substantially flat shape. The upper 120 has a shape that covers at least the entire instep portion of the inserted foot and is located above the sole 110A.

[0090] The upper 120 comprises an upper body 121, a shoe tongue 122, and shoelaces 123. Of these, the shoe tongue 122 and shoelaces 123 are both fixed or attached to the upper body 121.

[0091] The upper part of the upper body 121 is provided with an upper opening that exposes the upper part of the ankle and part of the instep. On the other hand, the lower part of the upper body 121 is provided with a lower opening that is covered by the sole 110A, for example, and in other examples, the bottom is formed by sewing the lower end of the upper body 121 into a bag.

[0092] The shoe tongue 122 is fixed to the upper body 121 by sewing, welding, bonding, or a combination thereof, so as to cover the portion of the upper opening provided in the upper body 121 that exposes a part of the instep. For the upper body 121 and shoe tongue 122, for example, woven fabric, knitted fabric, nonwoven fabric, synthetic leather, resin, etc., double raschel warp knit fabric woven with polyester yarn is used in shoes where breathability and lightness are particularly required.

[0093] The shoelaces 123 are string-like members used to pull together the edges of the upper opening in the upper body 121, which exposes a portion of the instep, in the width direction of the foot, and are inserted through a plurality of holes provided in the edge of the upper opening. By tightening the shoelaces 123 with the foot inserted into the upper body 121, the upper body 121 can be made to fit snugly against the foot.

[0094] As shown in Figures 15 to 18, the sole 110A comprises a midsole 111 and an outsole 112 as the sole body, a high-rigidity plate 113, and a rebound material 1. By assembling these midsole 111, outsole 112, high-rigidity plate 113, and rebound material 1 together, the sole 110A has a generally flattened shape with an upper surface 110a and a lower surface 110b.

[0095] Here, the rebound material 1 provided in the sole 110A has a basic structure similar to the rebound material 1A described above, and is shown in a darker color in the diagram for ease of understanding. By providing this rebound material 1 in the sole 110A, it becomes possible to create a sole and shoe that can generate high propulsion force when running, but the details of this will be explained later.

[0096] The midsole 111 is located above the outsole 112. As a result, the top surface 110a of the sole 110A is defined by the midsole 111, and the bottom surface 110b of the sole 110A is defined by the outsole 112. The high-rigidity plate 113 is embedded in the midsole 111 and is thereby fixed to the midsole 111. The rebound material 1 is also embedded in the midsole 111 by being housed in a notch 110d provided in the midsole 111, which will be described later.

[0097] As shown in Figures 16 and 17, the sole 110A is divided into a forefoot R1 that supports the toes and ball of the foot, a midfoot R2 that supports the arch of the foot, and a rearfoot R3 that supports the heel of the foot, along the front-to-back direction (left-to-right direction in Figure 16, up-to-down direction in Figure 17), which is the direction that coincides with the length of the wearer's foot when viewed from above.

[0098] Here, using the front end of the sole 110A as a reference, the first boundary position is defined as a position corresponding to 40% of the anterior-posterior dimension of the sole 110A from the front end, and the second boundary position is defined as a position corresponding to 80% of the anterior-posterior dimension of the sole 110A from the front end. In this case, the forefoot R1 corresponds to the portion included between the front end and the first boundary position in the anterior-posterior direction, the midfoot R2 corresponds to the portion included between the first boundary position and the second boundary position in the anterior-posterior direction, and the rearfoot R3 corresponds to the portion included between the second boundary position and the rear end of the sole in the anterior-posterior direction.

[0099] Furthermore, as shown in Figure 17, the sole 110A is divided into two parts along the left-right direction (left-right direction in the figure), which corresponds to the midline side (i.e., the side closer to the midline) of the foot in its anatomically orthogonal position (the part shown as S1 in the figure) and the lateral side (i.e., the side further from the midline) of the foot in its anatomically orthogonal position (i.e., the side further from the midline) (the part shown as S2 in the figure).

[0100] As shown in Figures 15 to 18, the midsole 111 extends along the anterior-posterior direction from the forefoot R1 through the midfoot R2 to the rearfoot R3. The midsole 111 has an upper surface 111a, a lower surface 111b, and sides connecting these upper and lower surfaces 111a and 111b, and constitutes the upper part of the sole 110A. The upper surface 111a of the midsole 111 constitutes the top surface 110a of the sole 110A as described above, and is joined to the upper 120 by, for example, adhesive.

[0101] Here, as shown in particular in Figure 18, the midsole 111 is composed of two members: an upper midsole portion 111A and a lower midsole portion 111B. The upper midsole portion 111A defines the top surface 110a of the sole 110A (i.e., the upper surface 111a of the midsole 111) and has a flat, roughly plate-like shape. On the other hand, the lower midsole portion 111B is located below the upper midsole portion 111A. The lower midsole portion 111B defines the lower surface 111b of the midsole 111 and has a relatively thick, roughly plate-like shape.

[0102] The upper surface of the upper midsole portion 111A, which defines the top surface 110a of the sole 110A, has a shape in which its peripheral edge is raised compared to the surrounding area. As a result, a concave portion is provided on the upper surface of the upper midsole portion 111A, and this concave portion becomes the part that receives the upper 120. The upper surface of the upper midsole portion 111A, excluding the peripheral edge which is the bottom surface of this concave portion, has a smooth curved shape to fit the shape of the sole of the foot.

[0103] The upper surface of the lower midsole portion 111B is provided with a recess 110c extending from the forefoot R1 to the rearfoot R3. This recess 110c is a portion for housing the high-rigidity plate 113 and has a shape that matches the outer shape of the high-rigidity plate 113.

[0104] Furthermore, a notch 110d is provided in a portion of the lower surface of the lower midsole portion 111B (i.e., the lower surface 111b of the midsole 111) that corresponds to the forefoot portion R1. As described above, this notch 110d is a portion for accommodating the rebound material 1, and is provided so as to reach not only the lower surface of the lower midsole portion 111B, but also the medial and lateral sides of the lower midsole portion 111B.

[0105] Furthermore, an opening 110e is provided in a portion of the upper surface of the lower midsole portion 111B that corresponds to the forefoot portion R1, for connecting the aforementioned recess 110c and notch 110d. This makes it possible to directly position the high-rigidity plate 113 housed in the recess 110c and the rebound material 1 housed in the notch 110d opposite each other without the midsole 111 in between, as will be described later.

[0106] The midsole 111 is made of a material with lower rigidity than the material constituting the rebound material 1. Preferably, the midsole 111 has moderate strength while also having excellent cushioning properties. From this viewpoint, the midsole 111 can be made of, for example, a resin or rubber component, and is particularly preferably made of foamed or non-foamed materials such as polyolefin resin, ethylene-vinyl acetate copolymer (EVA), polyamide-based thermoplastic elastomer (TPA, TPAE), thermoplastic polyurethane (TPU), or polyester-based thermoplastic elastomer (TPEE).

[0107] The upper midsole portion 111A and the lower midsole portion 111B are fixed together by overlapping them and joining them, for example, with an adhesive, while the high-rigidity plate 113 is housed in the recess 110c provided in the lower midsole portion 111B as described above.

[0108] As shown in Figures 15 to 18, the outsole 112 extends along the anterior-posterior direction from the forefoot R1 through the midfoot R2 to the rearfoot R3. The outsole 112 may be composed of a single component, or it may be composed of multiple components, as shown in Figure 18.

[0109] The outsole 112 has a thin, sheet-like shape and has an upper surface and a lower surface. The outsole 112 constitutes the lower part of the sole 110A, and its lower surface defines the bottom surface 110b of the sole 110A described above. The upper surface of the outsole 112 is joined to the lower surface 111b of the midsole 111, for example, by adhesive.

[0110] The outsole 112 preferably has excellent abrasion resistance and grip, and from this viewpoint, the outsole 112 can be made of rubber, for example. Furthermore, a tread pattern may be provided on the contact surface 112a, which is the lower surface of the outsole 112, from the viewpoint of improving grip.

[0111] As shown in Figures 16 to 18, the high-rigidity plate 113 is made of a single component and extends along the anterior-posterior direction (i.e., in a direction intersecting the contact surface 112a, which is the bottom surface 110b of the sole 110A) from the forefoot R1 through the midfoot R2 to the rearfoot R3. More specifically, the high-rigidity plate 113 spans the medial foot portion (S1 side portion) and the lateral foot portion (S2 side portion) of the sole 110A in the lateral direction, and is positioned in the anterior-posterior direction of the sole 110A, excluding the front end of the forefoot R1 and excluding the rear end of the rearfoot R3. In Figure 17, for ease of understanding, the area where the high-rigidity plate 113 is positioned is lightly colored.

[0112] The high-rigidity plate 113 is made up of a plate-like material as a whole and is fixed to the midsole 111 by being embedded in the midsole 111 as described above. More specifically, the high-rigidity plate 113 is housed in a recess 110c provided on the upper surface of the lower midsole portion 111B as described above, and is embedded in the midsole 111 by being sandwiched between the upper midsole portion 111A and the lower midsole portion 111B.

[0113] Here, as a specific method for embedding the high-rigidity plate 113 in the midsole 111, in addition to the method described above of dividing the midsole 111 into upper and lower halves and sandwiching the high-rigidity plate 113 between them when they are bonded together, other methods include, for example, inserting the high-rigidity plate 113 during the casting or injection molding of the midsole 111.

[0114] The high-rigidity plate 113 is made of a material with higher rigidity than the material that makes up the midsole 111. The material that makes up the high-rigidity plate 113 is not particularly limited, but for example, fiber-reinforced resins using carbon fibers, glass fibers, aramid fibers, Dyneema fibers, Zylon fibers, boron fibers, etc. as reinforcing fibers, or non-fiber-reinforced resins made of polymer resins such as urethane-based thermoplastic elastomer (TPU) or amide-based thermoplastic elastomer (TPA) can be suitably used.

[0115] As shown in Figures 15 to 18, the rebound material 1 has a basic structure similar to the rebound material 1A described above, and more specifically, its unit structure U is made up of a Kelvin structure that has been divided in the height direction into two parts and then given thickness.

[0116] Here, the rebound material 1 is modified in order to be incorporated into the sole 110A, while maintaining the basic structure of the aforementioned rebound material 1A, but with a slight deformation of its shape (for example, the outer shape of the unit structure U in a plan view, as shown particularly in Figure 18), and is otherwise the same as the aforementioned rebound material 1A.

[0117] The rebound material 1 is housed in a notch 110d provided in the lower midsole portion 111B, and is positioned so that its height direction (Z direction shown in the figure) coincides with the normal direction of the contact surface 112a, which is the bottom surface 110b of the sole 110A.

[0118] As described above, since an opening 110e is provided above the notch 110d of the lower midsole portion 111B, the upper surface of the rebound material 1 housed in the notch 110d faces the high-rigidity plate 113 through the opening 110e. As a result, the rebound material 1 is fixed to the high-rigidity plate 113 by joining the upper wall portion 11 of the rebound material 1 to the lower surface of the high-rigidity plate 113, for example by adhesive.

[0119] On the other hand, the lower surface of the rebound material 1 faces the outsole 112, and the rebound material 1 is fixed to the outsole 112 by joining the lower wall portion 12 of the rebound material 1 to the upper surface of the outsole 112, for example by adhesive.

[0120] In other words, the rebound material 1 is positioned such that its upper surface reaches the high-rigidity plate 113 and its lower surface reaches the outsole 112, and is thus sandwiched and held between the high-rigidity plate 113 and the outsole 112.

[0121] As mentioned above, the notch 110d containing the rebound material 1 extends to the medial and lateral sides of the midsole 111. Consequently, the rebound material 1 is exposed to the outside, and the open portion 14 (see Figure 16) formed on its side due to the structure of the rebound material 1 is also exposed to the outside.

[0122] Here, as shown in Figure 17 in particular, the rebound material 1 is positioned in the part of the forefoot R1 closer to the midfoot R2 so that it is located in the part that supports the wearer's toes. As a result, the rebound material 1 is positioned in the part of the wearer's foot ball of the big toe Supporting part Q1 and the wearer's foot Little toe ball It is positioned across the supporting portion Q2. With this configuration, the rebound material 1 is placed in the part of the forefoot R1 closer to the midfoot R2, where the greatest load is applied during running, making it possible to effectively obtain a high rebound force.

[0123] Here, due to its structure, the rebound material 1 retains essentially the same external shape even when inverted; however, inverting it causes a displacement of the surface irregularities. Therefore, it is necessary to determine the top and bottom of the rebound material 1 during manufacturing.

[0124] In order to obtain higher rebound performance, the wearer's foot ball of the big toe Supporting part Q1 and the wearer's foot Little toe ball It is preferable that the upper wall portion 11 of the rebound material 1 is not located in a position corresponding to the portion Q2 that supports the foot. However, the wearer's foot ball of the big toe Supporting part Q1 and the wearer's foot Little toe ball Even when the upper wall portion 11 of the rebound material 1 is positioned in a location corresponding to the supporting portion Q2, it is possible to obtain high rebound performance.

[0125] As described above, by using the sole 110A and the shoe 100 equipped therewith according to this embodiment, the rebound force of the rebound material 1 is applied to the wearer's foot during push-off due to the high rebound performance of the rebound material 1, thereby enabling the acquisition of high propulsion force. Therefore, with this configuration, it is possible to create a sole 110A and a shoe 100 equipped therewith that have excellent running performance.

[0126] (Differential variations of the first to third versions) Figures 19 to 21 are schematic plan views of the soles of the shoes according to the first to third modified examples, respectively. Hereinafter, the soles 110B to 110D according to the first to third modified examples based on the above-described embodiment will be explained with reference to Figures 19 to 21. These soles 110B to 110D according to the first to third modified examples are provided in the shoe 100 in place of the sole 110A according to the above-described embodiment.

[0127] As shown in Figures 19 to 21, the soles 110B to 110D according to the first to third modified examples differ from the sole 110A according to the above-described embodiment in that their configurations differ only in the position of the rebound material 1 when viewed from above. Here, in Figures 19 to 21, for the sake of drawing convenience, the specific shape of the rebound material 1 is not reproduced, and the area where the rebound material 1 is placed is colored darkly, while the area where the high-rigidity plate is placed is colored lightly.

[0128] As shown in Figure 19, in the sole 110B according to the first modified example, the rebound material 1 is placed only in the part of the forefoot R1 closer to the midfoot R2 and on the medial side (i.e., the S1 side). When configured in this way, the wearer's foot ball of the big toe While the rebound material 1 is positioned in a location corresponding to the supporting part Q1, the wearer's foot Little toe ball The rebound material 1 will not be placed in the position corresponding to the supporting portion Q2.

[0129] However, even with this configuration, a reasonable rebound force can be obtained, resulting in a sole 110B that provides high propulsion. Although not shown in the diagram, conversely, the rebound material 1 may be placed only in the part of the forefoot R1 closer to the midfoot R2 and on the outer side (i.e., the S2 side).

[0130] As shown in Figure 20, in the sole 110C according to the second modified example, the rebound material 1 is positioned only in the part of the forefoot R1 closer to the midfoot R2 and in the central part in the width direction of the foot. Even with this configuration, a reasonable rebound force can be obtained, making it possible to create a sole 110C that can provide high propulsion.

[0131] As shown in Figure 21, in the sole 110D according to the third modified example, the rebound material 1 is provided across almost the entire forefoot R1, midfoot R2, and rearfoot R3. With this configuration, a high rebound force is obtained across almost the entire forefoot R1, midfoot R2, and rearfoot R3, resulting in a sole 110D that can provide higher propulsion.

[0132] (Variations 4 through 7) Figures 22 to 25 are schematic side views of the sole according to the fourth to seventh modified examples, viewed from the outer foot side. Hereinafter, the soles 110E to 110H according to the fourth to seventh modified examples based on the above-described embodiment will be explained with reference to Figures 22 to 25. These soles 110E to 110H according to the fourth to seventh modified examples are provided in the shoe 100 in place of the sole 110A according to the above-described embodiment.

[0133] As shown in Figures 22 to 25, the soles 110E to 110H according to the fourth to seventh modified examples all differ from the sole 110A according to the above-described embodiment in that the position of the rebound material 1 is different when viewed from the side, or in addition in terms of the position, number, and presence or absence of the high-rigidity plate 113. Here, in Figures 22 to 25, for the sake of drawing convenience, the specific shape of the rebound material 1 is not reproduced, and the area where the rebound material 1 is placed is colored darkly, while the area where the high-rigidity plate is placed is colored lightly.

[0134] As shown in Figure 22, in the sole 110E according to the fourth modified example, the position of the high-rigidity plate 113 is the same as that of the sole 110A according to the above-described embodiment, whereas the rebound material 1 is positioned above the high-rigidity plate 113, rather than between the high-rigidity plate 113 and the outsole 112.

[0135] Specifically, the rebound material 1 is embedded in the midsole 111 such that its upper surface (i.e., upper wall portion 11) defines the top surface 110a of the sole 110E, and its lower surface (i.e., lower wall portion 12) reaches the high-rigidity plate 113. Accordingly, the rebound material 1 is fixed to the high-rigidity plate 113 by joining the lower wall portion 12 of the rebound material 1 to the upper surface of the high-rigidity plate 113, for example by adhesive.

[0136] Even with this configuration, a reasonable rebound force can be obtained, resulting in a sole 110E that provides high propulsion. In this configuration, it is preferable to place a midsole or insole with greater rigidity than the rebound material 1 on the upper surface of the sole 110E. With this configuration, the rebound material 1 is sandwiched between the midsole or insole and the high-rigidity plate 113, making it possible to obtain a high rebound force.

[0137] As shown in Figure 23, in the sole 110F according to the fifth modified example, the position of the high-rigidity plate 113 is the same as that of the sole 110A according to the above-described embodiment, whereas the rebound material 1 is positioned not only between the high-rigidity plate 113 and the outsole 112, but also above the high-rigidity plate 113. The specific configuration of this pair of rebound materials 1 is the same as that of the sole 110A according to the above-described embodiment and the sole 110E according to the fourth modified example.

[0138] With this configuration, a higher rebound force can be obtained, resulting in a shoe sole 110F that provides even greater propulsion.

[0139] As shown in Figure 24, in the sole 110G according to the sixth modified example, the configuration of the midsole 111 and the arrangement position and number of the high-rigidity plates 113 differ from those of the sole 110A according to the above-described embodiment, and the arrangement position of the rebound material 1 also differs from those of the sole 110A according to the above-described embodiment.

[0140] Specifically, in the sole 110G according to the sixth modification, the midsole 111 is made of a single material, with an upper high-rigidity plate 113A positioned to cover its upper surface 111a, and a lower high-rigidity plate 113B positioned to cover its lower surface 111b. Accordingly, the upper surface of the upper high-rigidity plate 113A defines the top surface 110a of the sole 110G.

[0141] The rebound material 1 is embedded in the midsole 111 such that its upper surface (i.e., upper wall portion 11) reaches the upper high-rigidity plate 113A and its lower surface (i.e., lower wall portion 12) reaches the lower high-rigidity plate 113B. Accordingly, the upper wall portion 11 of the rebound material 1 is joined to the lower surface of the upper high-rigidity plate 113A by means of adhesive, for example, and the lower wall portion 12 of the rebound material 1 is joined to the upper surface of the lower high-rigidity plate 113B by means of adhesive, for example, and the rebound material 1 is fixed to this pair of upper high-rigidity plates 113A and lower high-rigidity plates 113B.

[0142] With this configuration, a higher rebound force can be obtained, resulting in a shoe sole with even greater propulsion, 110G.

[0143] As shown in Figure 25, the sole 110H according to the seventh modified example differs from the sole 110A according to the above-described embodiment in that the configuration of the midsole 111 and the position of the rebound material 1 are different, and it does not have a high-rigidity plate 113 (see Figure 16, etc.).

[0144] Specifically, in the sole 110H according to the seventh modified example, the midsole 111 is made of a single component, and the rebound material 1 is arranged so as to be exposed on both the upper surface 111a and the lower surface 111b of the midsole 111. As a result, the rebound material 1 is embedded in the midsole 111 such that its upper surface (i.e., upper wall portion 11) defines the top surface 110a of the sole 110H, and its lower surface (i.e., lower wall portion 12) reaches the outsole 112. Accordingly, the rebound material 1 is fixed to the outsole 112 by joining the lower wall portion 12 of the rebound material 1 to the upper surface of the outsole 112, for example by adhesive.

[0145] Even with this configuration, a reasonable rebound force can be obtained, resulting in a sole 110H that provides high propulsion. In this configuration, it is preferable to place a midsole or insole with greater rigidity than the rebound material 1 on the upper surface of the sole 110H. With this configuration, the rebound material 1 is sandwiched between the midsole or insole and the outsole 112, making it possible to obtain a high rebound force.

[0146] Figure 26(A) is a perspective view of a rebound material having a structure similar to the rebound material provided in the sole of the embodiment, and Figure 26(B) is a perspective view of the unit structure constituting the rebound material. Furthermore, Figure 27(A) is a plan view of the rebound material shown in Figure 26(A) when viewed along the direction of arrow XXVIIA shown in Figure 26(A). Figure 27(B) and Figure 27(C) These are, Figure 27(A) These are cross-sectional views along the lines XXVIIB-XXVIIB and XXVIIC-XXVIIC shown in the image. These are shown below in Figures 26(A) and 26(B). Figure 27(A) Referring to Figures 27(B) and 27(C), the structure of the rebound material 1B, which has a structure similar to the rebound material provided in the sole of the shoe according to the above-described embodiment, will be explained.

[0147] As shown in Figures 26(A) and 27(A) to 27(C), the rebound material 1B includes a three-dimensional structure S having a plurality of unit structures U. Each of the plurality of unit structures U has a three-dimensional shape formed by walls 10 whose outer shape is defined by a pair of parallel curved surfaces (see Figure 26(B)), and thus the three-dimensional structure S also has a three-dimensional shape formed by walls 10 whose outer shape is defined by a pair of parallel curved surfaces.

[0148] The unit structure U has a structure based on a geometric surface structure, with added thickness. More specifically, the unit structure U is constructed by dividing a mathematically defined triple-periodic minimal surface structure unit in one of its three orthogonal axis directions into two, and then adding thickness to each. A minimal surface is defined as the surface with the smallest area among surfaces bounded by a given closed curve.

[0149] In the unit structure U shown in Figure 26(B), the aforementioned surface structure is a Schwarz P structure, and the unit structure U is composed of a Schwarz P structure whose structural unit is divided into two in the height direction (Z-axis direction shown in the figure) among the three orthogonal axes, and then further thickened.

[0150] More specifically, the unit structure U includes one upper wall section 11, four divided lower wall sections 12', and one vertical wall section 13 connecting the upper wall section 11 and the lower wall sections 12'. The vertical wall section 13 extends so as to intersect with the upper wall section 11 and the lower wall sections 12', and the structure as a whole has a roughly annular shape. The upper wall section 11 and the lower wall sections 12' each have a flat plate shape, while the vertical wall section 13 has a curved plate shape.

[0151] The four divided lower wall sections 12' are integrated by becoming continuous with the lower wall sections 12' included in other unit structures U located adjacent to the unit structure U containing it. As a result, in the three-dimensional structure S, the lower wall sections 12' included in each of these four adjacent unit structures U are continuous with each other, forming a single lower wall section 12 having substantially the same shape as the single upper wall section 11 described above (see Figure 26(A), etc.).

[0152] The rebound material 1B according to this embodiment is designed to exhibit a rebound function in the height direction as described above. Therefore, as shown in Figures 26(A) and 27(A) to 27(C), the multiple unit structures U are arranged regularly and continuously in repeated patterns along the width direction (X direction in the figures) and depth direction (Y direction in the figures) of the three orthogonal axes. As a result, when the three-dimensional structure S is viewed from above, it has a structure in which upward-convex and downward-convex portions are arranged alternately. Note that in Figures 26(A) and 27(A) to 27(C), three adjacent unit structures U in the width direction and depth direction are shown separately.

[0153] In this embodiment, we will describe a rebound material 1B that has a large number of unit structures U in the width direction and depth direction, respectively, but the number of repetitions of the unit structures U in the width direction and depth direction is not particularly limited. That is, the rebound material may be composed of two or more unit structures U arranged along only one of the width direction and depth direction, or it may be a rebound material consisting of only one unit structure U.

[0154] Furthermore, the manufacturing method and materials for the rebound material 1B can be the same as those described above for the rebound material 1A.

[0155] In the rebound material 1B configured in this way, as with the rebound material 1A described above, compressive deformation occurs when a load is gradually applied by pressing along its height direction (the Z-axis direction shown in the figure). In this case, due to its structure, deformation occurs in the vertical wall portion 13 of the rebound material 1B, and buckling occurs in the vertical wall portion 13 when a load exceeding a certain level is applied.

[0156] On the other hand, when this pressure is released, the load applied to the rebound material 1B along the height direction decreases and disappears, and consequently, the compressive deformation that had occurred in the rebound material 1B is released, and the rebound material 1B returns to its original shape. At this time, the buckling that had occurred in the rebound material 1B is also eliminated. When this compressive deformation is released, a rebound force is generated by the elastic restoring force of the rebound material 1B, and this rebound force determines the rebound performance of the rebound material 1B.

[0157] <Verification Test 5> In Verification Test 5, a simulation model corresponding to the aforementioned rebound material 1B was created as Verification Example 7, and the stress-strain curve of the rebound material related to Verification Example 7, which consists of the simulation model, was calculated by performing structural analysis on this model using the finite element method (FEM).

[0158] Figure 28 is a graph showing the simulation results of the rebound performance of the rebound material related to Verification Example 7, and Figure 29 is a table showing the characteristics of the rebound material related to Verification Example 7. Here, in Figures 28 and 29, for comparison, the results of Comparative Example 2, which was confirmed to have the highest rebound force in the aforementioned Verification Test 1, are also included.

[0159] As shown in Figure 28, the stress-strain curve of the rebound material in Verification Example 7 was similar to the stress-strain curve of the rebound material 1A described above (see Figure 4). That is, the rebound material in Verification Example 7 has the same characteristics as the stress-strain curve of the rebound material 1A described above. distortion Due to the increase stress The loading process has a region where it hardly changes, and consequently, distortion Due to the decrease stressThe unloading process had a region where it hardly changed.

[0160] Here, as shown in Figure 29, the standardized AER of the rebound material in Verification Example 7 is 0.047 [J / cm²], assuming an energy return rate of 80%. 3 The result was as follows: The standardized AER of the rebound material in this verification example 7 exceeded that of the standardized AER of the cushioning material in comparative example 2, and it was confirmed that high rebound performance can be obtained by using rebound material 1B with the above configuration.

[0161] Furthermore, it was calculated that the buckling initiation point of the rebound material in Verification Example 7 is at a point where the stress σ is 0.123 [MPa] and the strain ε is 18 [%]. In other words, it was confirmed that the buckling initiation point of the rebound material in Verification Example 7 falls within both the required stress range and the required strain range.

[0162] <Summary of Verification Test 5> Based on the results of Verification Test 5 described above, it is understood that an unprecedentedly high rebound force can be obtained by using a rebound material having a three-dimensional shape formed by walls whose outer shape is defined by a pair of parallel curved surfaces, such that buckling can occur when a compressive force is applied, and by configuring the rebound material so that buckling of the rebound material begins in the aforementioned required strain range and required stress range when the load applied to the rebound material is gradually increased.

[0163] Therefore, by designing the rebound material so that buckling begins within the required strain range and required stress range described above, a high rebound force can be obtained. By applying this to the sole of a shoe, it is possible to create a sole and shoe that provide high propulsion during running. In other words, by applying the above-described rebound material 1B as the rebound material 1 provided in the soles 110A to 110H according to the above-described embodiment and its modified form, it is possible to create a sole and shoe equipped therewith that have excellent running performance.

[0164] Here, the rebound material 1B described above was composed of a unit structure U which was made by dividing a Schwartz P structure in the height direction into two and then adding thickness to it. Other structures that can be used as structural units for triple periodic minimal surfaces include gyroid structures and Schwartz D structures. By constructing a rebound material by dividing these structural units in one of the three orthogonal axis directions into two and then adding thickness to them, a rebound material that can obtain a high rebound force can be made.

[0165] <Shoe soles and shoes related to the 8th and 9th variations> (Variation 8) Figure 30 shows the sole of the eighth modified example viewed from the outer side of the foot. Side view Figure 31 is a schematic bottom view of the outsole provided on the sole of the shoe. Hereinafter, the sole 110I according to the eighth modified example based on the above-described embodiment will be described with reference to Figures 30 and 31. This sole 110I according to the eighth modified example is provided on the shoe 100 in place of the sole 110A according to the above-described embodiment.

[0166] As shown in Figure 30, the sole 110I according to the eighth modified example has a midsole 111 and an outsole 112, similar to the sole 110A according to the above-described embodiment, but also includes a high-rigidity plate 113 (see Figure 16, etc.). te Its configuration differs from the sole 110A of the above-described embodiment in that it does not have an insole 114 and is equipped with an insole 114.

[0167] Specifically, the sole 110I according to the eighth modified example comprises a midsole 111 and an outsole 112 as the sole body, and an insole 114 The sole 110I has the following features, and in this sole 110I, the rebound material 1 is made up of a part of the outsole 112. In other words, in the sole 110I, there is no rebound material made up of a single component, and instead, a part of the outsole 112 is configured to function as a rebound material.

[0168] The midsole 111 extends along the anterior-posterior direction from the forefoot R1 through the midfoot R2 to the rearfoot R3. The midsole 111 is made of a material with lower rigidity than the material that makes up the outsole 112, which also serves as the rebound material 1, and has a substantially flattened shape with an upper surface 111a and a lower surface 111b.

[0169] As shown in Figures 30 and 31, the outsole 112 extends along the anterior-posterior direction from the forefoot R1 through the midfoot R2 to the rearfoot R3, and is joined to the lower surface 111b of the midsole 111 by means of adhesive, for example, so as to cover the lower surface 111b of the midsole 111. The outsole 112 has a substantially flattened shape, and its lower surface defines the contact surface 112a as the bottom surface 110b of the sole 110I.

[0170] A portion that functions as the rebound material 1 described above is provided at a predetermined position on the lower surface of the outsole 112. For ease of understanding, this portion is shown in a dark color in the figure. The outsole 112 portion that functions as the rebound material 1 has a three-dimensional shape formed by walls 10 whose outer shape is defined by a pair of parallel planes, and includes multiple upper wall portions 11, lower wall portions 12, and vertical wall portions 13 described above. As a result, the outsole 112 portion that functions as the rebound material 1 is positioned to be exposed to the outside on the bottom surface 110b side of the sole 110I. Multiple open portions 14 are located on the side of the outsole 112 portion that functions as the rebound material 1.

[0171] Here, the outsole 112, which functions as the rebound material 1, is provided over almost the entire contact surface 112a of the outsole 112, excluding the part near the front end of the forefoot R1 and the part near the rear end of the rearfoot R3, and the wearer's foot ball of the big toe Supporting part Q1 and the wearer's foot Little toe ball It is positioned to include portion Q2 that supports it.

[0172] The outsole 112 can be made of thermoplastic elastomer or rubber, and can be manufactured by molding, for example, injection molding, casting, or sheet molding using a mold, or by fabrication using a three-dimensional additive manufacturing device.

[0173] As shown in Figure 30, the insole 114 It extends along the anterior-posterior direction from the forefoot R1 through the midfoot R2 to the rearfoot R3, and is positioned to cover the upper surface 111a of the midsole 111. The insole 114 has a substantially flattened shape, and its upper surface 114a defines the top surface 110a of the sole 110I.

[0174] The insole 114 is detachably attached to the upper surface 111a of the midsole 111, and more specifically, it is positioned on the upper surface 111a of the midsole 111 by being inserted into the internal space of the upper 120. The material of the insole 114 is not particularly limited and can be made of various resin materials, rubber materials, etc.

[0175] In the sole 110I described above, as mentioned above, the rebound material 1 is composed of a part of the outsole 112. Therefore, based on the high rebound performance of the outsole 112 in the part that functions as the rebound material 1, the rebound force of the rebound material 1 is applied to the wearer's foot when pushing off. Consequently, with this configuration, it becomes possible to obtain a high propulsion force, resulting in a sole 110I and a shoe 100 equipped with it that have excellent running performance.

[0176] (9th variation) Figure 32 shows the sole of the ninth modified example viewed from the outer side of the foot. Side view Figure 33 is a schematic bottom view of the insole provided in the sole of the shoe. Hereinafter, the sole 110J according to the ninth modified example based on the above-described embodiment will be described with reference to Figures 32 and 33. This sole 110J according to the ninth modified example is provided in the shoe 100 in place of the sole 110A according to the above-described embodiment.

[0177] As shown in Figure 32, the sole 110J according to the ninth modified example has a midsole 111 and an outsole 112, similar to the sole 110A according to the embodiment described above, but also includes a high-rigidity plate 113 (see Figure 16, etc.). te Its configuration differs from the sole 110A of the above-described embodiment in that it does not have an insole 114 and is equipped with an insole 114.

[0178] Specifically, the sole 110J according to the ninth modified example consists of a midsole 111 and an outsole 112 as the sole body, and an insole 114 The sole 110J has the following features, and in this sole 110J, the rebound material 1 is composed of a part of the insole 114. In other words, the sole 110J does not have a rebound material made of a single component, and instead, a part of the insole 114 is configured to function as a rebound material.

[0179] The midsole 111 extends along the anterior-posterior direction from the forefoot R1 through the midfoot R2 to the rearfoot R3. The midsole 111 is made of a material with lower rigidity than the material that makes up the insole 114, which also serves as the rebound material 1, and has a substantially flattened shape with an upper surface 111a and a lower surface 111b.

[0180] The outsole 112 extends along the front-to-back direction from the forefoot R1 through the midfoot R2 to the rearfoot R3, and is joined to the lower surface 111b of the midsole 111, for example by adhesive, so as to cover the lower surface 111b of the midsole 111. The outsole 112 has a substantially flat shape, and its lower surface defines the contact surface 112a as the bottom surface 110b of the sole 110J. The material of the outsole 112 is not particularly limited and can be made of various resin materials, rubber materials, etc.

[0181] As shown in Figures 32 and 33, the insole 114It extends along the anterior-posterior direction from the forefoot R1 through the midfoot R2 to the rearfoot R3, and is positioned to cover the upper surface 111a of the midsole 111. The insole 114 has a substantially flat shape, and its upper surface 114a is the sole. 110J The top surface of 110a is specified.

[0182] The insole 114 is detachably provided on the upper surface 111a of the midsole 111, and more specifically, it is positioned on the upper surface 111a of the midsole 111 by being inserted into the internal space of the upper 120.

[0183] A portion that functions as the rebound material 1 described above is provided at a predetermined position on the lower surface of the insole 114. For ease of understanding, this portion is shown in a dark color in the figure. The portion of the insole 114 that functions as the rebound material 1 has a three-dimensional shape formed by walls 10 whose outer shape is defined by a pair of parallel planes, and includes multiple upper wall portions 11, lower wall portions 12, and vertical wall portions 13 described above. In addition, there are multiple open portions 14 that are exposed to the outside on the sides of the portion of the insole 114 that functions as the rebound material 1.

[0184] Here, the insole 114, which functions as the rebound material 1, is provided over almost the entire underside of the insole 114, excluding the part near the front end of the forefoot R1 and the part near the rear end of the rearfoot R3, and the wearer's foot ball of the big toe Supporting part Q1 and the wearer's foot Little toe ball It is positioned to include portion Q2 that supports it.

[0185] The insole 114 can be made of thermoplastic elastomer or rubber, and can be manufactured by molding, for example, injection molding, casting, or sheet molding using a mold, or by fabrication using a three-dimensional additive manufacturing device.

[0186] In the sole 110J described above, as mentioned above, the rebound material 1 is composed of a part of the insole 114. Therefore, based on the high rebound performance of the insole 114 that functions as the rebound material 1, the rebound force of the rebound material 1 is applied to the wearer's foot when pushing off. Consequently, with this configuration, it becomes possible to obtain high propulsion force, resulting in a sole 110J and a shoe 100 equipped with it that have excellent running performance.

[0187] <Summary of Disclosures in Embodiments, etc.> The characteristic configurations disclosed in the embodiments described above and their variations can be summarized as follows:

[0188] A sole according to one aspect of the present disclosure comprises a rebound material and has a bottom surface which is the contact surface and a top surface located opposite to the bottom surface. The rebound material has a three-dimensional shape formed by walls whose outer shape is defined by a pair of parallel planes or curved surfaces, and along the direction normal to the bottom surface. Compression force Buckling may occur when a force is applied. In a sole according to one embodiment of the present disclosure, the rebound material is applied along the normal direction. Compression force When the load is gradually increased on the sole of the shoe so that the rebound material is subjected to the following action: Occur Buckling of the rebound material begins when the stress is in the range of 0.05 MPa to 0.55 MPa and the strain of the rebound material in the normal direction is in the range of 10% to 60%.

[0189] In a sole according to one aspect of the above disclosure, the rebound material is provided for the wearer's foot. ball of the big toe It may be positioned at least in the part that supports it.

[0190] In a sole according to one aspect of the above disclosure, the rebound material is provided for the wearer's foot. Little toe ball It may be positioned at least in the part that supports it.

[0191] In a shoe sole according to one aspect of the above disclosure, the rebound material may be composed of a three-dimensional structure in which the three-dimensional shape formed by the wall is used as a unit structure, and the unit structures are arranged regularly and continuously in a direction that intersects the normal direction at least.

[0192] In a shoe sole according to one aspect of the above disclosure, the unit structure may be constructed by dividing a structural unit consisting of a plurality of planes arranged to intersect each other so as to have a cavity inside, in one of the three orthogonal axis directions, into two parts and then adding thickness to each part.

[0193] In a shoe sole according to one aspect of the above disclosure, the structural unit may be any of the structural units selected from the Kelvin structure, the octet structure, the cubic structure, and the cubic octet structure.

[0194] In a shoe sole according to one aspect of the above disclosure, the unit structure may be formed by dividing a triple-periodic minimum surface structure unit into two in any of its three orthogonal axis directions and then adding thickness to each.

[0195] In a sole according to one aspect of the above disclosure, the structural unit may be any of the Schwartz P structure, gyroid structure, and Schwartz D structure.

[0196] An outsole according to one aspect of the above disclosure may be made of a material less rigid than the material constituting the rebound material, and may further comprise a midsole including an upper surface defining the top surface, and an outsole covering the lower surface of the midsole and defining the bottom surface. In this case, the rebound material may be embedded in the midsole such that the upper surface of the rebound material defines the top surface and the lower surface of the rebound material reaches the outsole.

[0197] An outsole according to one aspect of the above disclosure may further comprise a midsole made of a material less rigid than the material constituting the rebound material, including an upper surface defining the top surface, and a high-rigidity plate made of a material more rigid than the material constituting the midsole. In this case, the high-rigidity plate may be embedded in the midsole so as to extend in a direction intersecting the normal direction, and in this case, the rebound material may be embedded in the midsole such that the upper surface of the rebound material defines the top surface and the lower surface of the rebound material reaches the high-rigidity plate.

[0198] An outsole according to one aspect of the above disclosure may further comprise a midsole made of a material less rigid than the material constituting the rebound material, including an upper surface defining the top surface, an outsole covering the lower surface of the midsole and defining the bottom surface, and a high-rigidity plate made of a material more rigid than the material constituting the midsole. In this case, the high-rigidity plate may be embedded in the midsole so as to extend in a direction intersecting the normal direction, and in this case, the rebound material may be embedded in the midsole so as to reach the high-rigidity plate on the upper surface of the rebound material and the outsole on the lower surface of the rebound material.

[0199] An outsole according to one aspect of the above disclosure may further comprise a midsole made of a material less rigid than the material constituting the rebound material, including an upper surface defining the top surface, an outsole covering the lower surface of the midsole and defining the bottom surface, and an upper high-rigidity plate and a lower high-rigidity plate made of a material more rigid than the material constituting the midsole. In this case, the upper high-rigidity plate may be positioned to cover the upper surface of the midsole so as to extend in a direction intersecting the normal direction, and the lower high-rigidity plate may be positioned to cover the lower surface of the midsole so as to extend in a direction intersecting the normal direction. In this case, the rebound material may be embedded in the midsole such that its upper surface reaches the upper high-rigidity plate and its lower surface reaches the lower high-rigidity plate.

[0200] An outsole according to one aspect of the above disclosure may comprise a midsole made of a material less rigid than the material constituting the rebound material, and an outsole covering the lower surface of the midsole and defining the bottom surface. In this case, the rebound material may be made up of at least a part of the outsole.

[0201] An outsole according to one aspect of the above disclosure may comprise a midsole made of a material less rigid than the material constituting the rebound material, and an insole covering the upper surface of the midsole and defining the top surface. In this case, the rebound material may be made up of at least a part of the insole.

[0202] A shoe according to one aspect of the present disclosure comprises a sole according to the present disclosure described above and an upper provided above the sole.

[0203] <Other forms, etc.> In the embodiments and their modifications described above, the example described was one in which a rebound material is provided on a part of the sole, which comprises a midsole and an outsole. However, the entire sole may be made of rebound material, or the rebound material may be provided on a sole that does not have either a midsole or an outsole.

[0204] Furthermore, in the embodiments and their modifications described above, the example given was that the rebound material is configured to have not only a vertical wall portion but also an upper wall portion and a lower wall portion. However, the rebound material may be configured to have neither an upper wall portion nor a lower wall portion, or both. In other words, since buckling that improves rebound performance mainly occurs in the vertical wall portion, the upper wall portion and lower wall portion are not essential components as long as the rebound material can be attached to the sole of the shoe by some method.

[0205] Furthermore, although the above-described embodiments and their modifications have been explained using a sole configured to have only one rebound material as an example, multiple rebound materials may be provided on the sole, separated from each other.

[0206] Furthermore, in the embodiments and their modifications described above, the rebound material was explained using an example where a structural unit of a geometric surface structure is divided in one of the three orthogonal axis directions and then thickened, but it is not necessary to use such a configuration. That is, any rebound material is acceptable as long as it is configured to have a three-dimensional shape formed by walls whose outer shape is defined by a pair of parallel planes or curved surfaces, and buckling occurs in the rebound material within the required stress range and required strain range described above. Also, even when a rebound material is constructed by dividing a structural unit of a geometric surface structure in one of the three orthogonal axis directions and then thickening, modifications such as chamfering the corners, changing the thickness for each part, or slightly changing the shape of the unit structure may be made as appropriate.

[0207] Furthermore, although the embodiments and their modifications described above have been illustrated by illustrating the application of the present invention to shoes equipped with a tongue and shoelaces, the present invention may also be applied to shoes without these (for example, shoes equipped with a sock-like upper) and the soles provided therein.

[0208] Furthermore, the characteristic configurations disclosed in the above-described embodiments and their variations can be combined with each other without departing from the spirit of the present invention.

[0209] Thus, the embodiments and their variations disclosed herein are illustrative in all respects and not restrictive. The technical scope of the present invention is defined by the claims and includes all modifications within the meaning and scope equivalent to the claims. [Explanation of Symbols]

[0210] 1,1A,1B Rebound material, 10 Wall, 11 Upper wall section, 12,12' Lower wall section, 13 Vertical wall section, 14 Open section, 21 Upper member, 22 Lower member, 100 Shoe, 110A~110J Sole, 110a Top surface, 110b Bottom surface, 110c Recess, 110d Notch section, 110e Opening, 111 Midsole, 111A Upper midsole section, 111B Lower midsole section, 111a Top surface, 111b Bottom surface, 112 Outsole, 112a Contact surface, 113 High-rigidity plate, 113A Upper high-rigidity plate, 113B Lower high-rigidity plate, 114 Insole, 114a Top surface, 120 Upper, 121 Upper body, 122 Tongue, 123 laces, R1 forefoot, R2 midfoot, R3 rearfoot, Q1 ball of the big toe Q2 Little toe ball The supporting part, S is a three-dimensional structure, and U is a unit structure.

Claims

1. A shoe sole that is equipped with a rebound material and has a bottom surface that is the contact surface and a top surface located on the opposite side of the bottom surface, The rebound material has a three-dimensional shape formed by walls whose outer shape is defined by a pair of parallel planes or curved surfaces. The aforementioned rebound material is capable of buckling when a compressive force is applied along the direction normal to the bottom surface. The modulus of elasticity of the base material of the aforementioned rebound material is 4 MPa or more and 30 MPa or less. A sole in which, when a load is gradually increased on the sole so as to apply a compressive force to the rebound material along the normal direction, buckling of the rebound material begins when the stress generated in the rebound material is in the range of 0.05 MPa to 0.55 MPa and the strain of the rebound material in the normal direction is in the range of 10% to 60%.

2. The sole of a shoe according to claim 1, wherein the rebound material is disposed at least in the portion that supports the ball of the foot of the wearer's toe.

3. The sole of a shoe according to claim 1 or 2, wherein the rebound material is disposed at least in the portion that supports the ball of the little toe of the wearer's foot.

4. A shoe sole that is equipped with a rebound material and has a bottom surface that is the contact surface and a top surface located on the opposite side of the bottom surface, The forefoot portion supports the toes and ball of the foot of the wearer, The midfoot supports the arch of the wearer's foot, It comprises a rear foot portion that supports the heel of the wearer's foot, The rebound material has a three-dimensional shape formed by walls whose outer shape is defined by a pair of parallel planes or curved surfaces. The aforementioned rebound material may buckle when a compressive force is applied along the direction normal to the bottom surface. A notch is provided in a part of the forefoot, and the rebound material is housed in the notch, so that the rebound material is positioned only in the portion of the sole where the notch is provided, and that it spans across the portion that supports the ball of the wearer's big toe and the portion that supports the ball of the wearer's little toe. A sole in which, when a load is gradually increased on the sole so as to apply a compressive force to the rebound material along the normal direction, buckling of the rebound material begins when the stress generated in the rebound material is in the range of 0.05 MPa to 0.55 MPa and the strain of the rebound material in the normal direction is in the range of 10% to 60%.

5. The sole of a shoe according to any one of claims 1 to 4, wherein the rebound material consists of a three-dimensional structure in which the three-dimensional shape formed by the wall is used as a unit structure, and the unit structures are arranged regularly and continuously in a direction that intersects the normal direction at least.

6. The sole of a shoe according to claim 5, wherein the unit structure is made up of a structural unit consisting of a plurality of planes arranged to intersect each other so as to have a cavity inside, divided in one of the three orthogonal axis directions and further thickened.

7. The sole of a shoe according to claim 6, wherein the structural unit is any one of the structural units selected from a Kelvin structure, an octet structure, a cubic structure, and a cubic octet structure.

8. The sole of a shoe according to claim 5, wherein the unit structure is made up of a structural unit of a triple periodic minimal surface that is divided into two in any of its three orthogonal axis directions, and then further thickened.

9. The sole of a shoe according to claim 8, wherein the structural unit is any one of the structural units of Schwartz P structure, gyroid structure, and Schwartz D structure.

10. The midsole is made of a material with lower rigidity than the material constituting the aforementioned rebound material, and includes an upper surface that defines the top surface, The system further comprises an outsole that covers the lower surface of the midsole and defines the bottom surface, The sole of a shoe according to any one of claims 1 to 9, wherein the rebound material is embedded in the midsole such that the upper surface of the rebound material defines the top surface and the lower surface of the rebound material reaches the outsole.

11. The midsole is made of a material with lower rigidity than the material constituting the aforementioned rebound material, and includes an upper surface that defines the top surface, The midsole further comprises a high-rigidity plate made of a material with higher rigidity than the material constituting the midsole, The high-rigidity plate is embedded in the midsole so as to extend in a direction intersecting the normal direction, The sole of a shoe according to any one of claims 1 to 9, wherein the rebound material is embedded in the midsole such that the upper surface of the rebound material defines the top surface and the lower surface of the rebound material reaches the high-rigidity plate.

12. The midsole is made of a material with lower rigidity than the material constituting the aforementioned rebound material, and includes an upper surface that defines the top surface, The outsole covers the lower surface of the midsole and defines the bottom surface, The midsole further comprises a high-rigidity plate made of a material with higher rigidity than the material constituting the midsole, The high-rigidity plate is embedded in the midsole so as to extend in a direction intersecting the normal direction, The sole of a shoe according to any one of claims 1 to 9, wherein the rebound material is embedded in the midsole such that the upper surface of the rebound material reaches the high-rigidity plate and the lower surface of the rebound material reaches the outsole.

13. The midsole is made of a material with lower rigidity than the material constituting the aforementioned rebound material, and includes an upper surface that defines the top surface, The outsole covers the lower surface of the midsole and defines the bottom surface, The midsole further comprises an upper high-rigidity plate and a lower high-rigidity plate, both made of a material with higher rigidity than the material constituting the midsole. The upper high-rigidity plate is positioned to cover the upper surface of the midsole so as to extend in a direction intersecting the normal direction, The lower high-rigidity plate is positioned to cover the lower surface of the midsole so as to extend in a direction intersecting the normal direction, The sole of a shoe according to any one of claims 1 to 9, wherein the rebound material is embedded in the midsole such that the upper surface of the rebound material reaches the upper high-rigidity plate and the lower surface of the rebound material reaches the lower high-rigidity plate.

14. A midsole made of a material with lower rigidity than the material constituting the aforementioned rebound material, The midsole covers the lower surface and comprises an outsole that defines the bottom surface, The sole according to any one of claims 1 to 9, wherein the rebound material is composed of at least a portion of the outsole.

15. A midsole made of a material with lower rigidity than the material constituting the aforementioned rebound material, The midsole covers the upper surface and includes an insole that defines the top surface, The sole of a shoe according to any one of claims 1 to 9, wherein the rebound material is composed of at least a portion of the insole.

16. A sole according to any one of claims 1 to 15, A shoe comprising an upper provided above the sole of the shoe.

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