Soles and shoes

Abstract

To provide a sole enhanced in buffer performance.SOLUTION: A sole 110A includes a buffer material 1 having a three-dimensional shape formed by a wall 10 whose outer shape is regulated by a pair of parallel flat surfaces or curve surfaces, and generating buckling when compressive force is applied along a normal line direction of a ground plane 112a. When a weight is gradually increased to load the sole 110A so as to apply compressive force to the buffer material 1 along the normal line direction, buckling of the buffer material 1 starts in a range of 0.15 MPa or more and 0.80 MPa or less of stress generated on the buffer material 1, and in a range of 10% or more and 60% or less of strain of the buffer material 1 in the normal line direction. A point when a strain energy density of the buffer material 1 reaches 0.157 J / cm3 is a specified time point, a maximal value of stress generated in the buffer material 1 until reaching the specified time point is 0.80 MPa or less, and a tangent line elastic modulus of the buffer material 1 at the specified time point is 5.00 MPa or less.SELECTED DRAWING: Figure 15

Description

[Technical Field]

[0001] The present invention relates to a shoe sole equipped with a cushioning 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 Initiative] [Problems that the invention aims to solve]

[0007] Generally, in order to improve the cushioning performance of a shoe sole, the sole should be designed so that the strain energy accumulated in the sole during landing is at its maximum. Occur Minimizing stress is effective. Various studies have been conducted from both material and structural perspectives to ensure that cushioning materials meet these conditions, but there is still considerable room for improvement, and further enhancement of cushioning performance is required.

[0008] Therefore, the present invention aims to provide a shoe sole with enhanced cushioning performance and a shoe equipped therewith. [Means for solving the problem]

[0009] This invention The first phase The sole of the shoe, based on this design, is equipped with a cushioning 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 cushioning 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 cushioning material is between 12 MPa and 40 MPa. The above invention The first phase In the case of a shoe sole based on the above, when a load is gradually increased on the shoe sole so that a compressive force is applied to the cushioning material along the normal direction, buckling of the cushioning material begins when the stress generated in the cushioning material is in the range of 0.15 MPa to 0.80 MPa and the strain of the cushioning material in the normal direction is in the range of 10% to 60%, and the strain energy density of the cushioning material is 0.157 J / cm². 3When the time point of reaching [a certain value] is defined as the specific time point, the maximum value of the stress generated in the buffer material from the start of applying the compressive force to the buffer material until reaching the specific time point is 0.80 MPa or less, and the tangent elastic modulus of the buffer material at the specific time point is 5.00 MPa or less. A shoe sole based on a second aspect of the present invention is provided with a cushioning 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 shoe 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 cushioning 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. Notches are provided on the periphery of the sole of the shoe, specifically in the portion spanning the posterior end of the outer side of the midfoot and the outer side of the rearfoot, the portion spanning the posterior end of the inner side of the midfoot and the inner side of the rearfoot, and the portion spanning the posterior end of the outer side of the forefoot and the anterior end of the outer side of the midfoot. The cushioning material is housed in these notches, so that the cushioning material is positioned only along the portions of the sole of the shoe in which the notches are provided, and along the portions that support the ball of the little toe and the heel of the wearer's foot. In the sole based on 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 cushioning material along the normal direction, buckling of the cushioning material begins when the stress generated in the cushioning material is in the range of 0.15 MPa to 0.80 MPa and the strain of the cushioning material in the normal direction is in the range of 10% to 60%, and the strain energy density of the cushioning material is 0.157 J / cm². 3 When the point at which the specified point is reached is defined as the specified point in time, the maximum stress generated in the cushioning material from the start of applying compressive force to the cushioning material until the specified point in time is 0.80 MPa or less, and the tangential modulus of elasticity of the cushioning material at the specified point in time is 5.00 MPa or less.

[0010] The shoe according to the present invention is The first or second phase composed of a shoe sole according to the present invention and an upper provided above the shoe sole.

Advantages of the Invention

[0011] According to the present invention, it becomes possible to provide a shoe sole with enhanced cushioning performance and a shoe provided with the same.

Brief Description of the Drawings

[0012] [Figure 1] A perspective view of a buffer material having basically the same structure as the buffer material included in the shoe sole according to the embodiment, and a perspective view of a unit structure constituting the buffer material. [Figure 2] A plan view and a cross-sectional view of the buffer material shown in FIG. 1. [Figure 3] A diagram schematically showing buckling that can occur in the buffer material shown in FIG. 1. [Figure 4] A graph showing the cushioning performance of the buffer material shown in FIG. 1. [Figure 5] A graph showing the cushioning performance of a general buffer material. [Figure 6] A graph showing the results of measuring the cushioning performance of the buffer materials according to Comparative Examples 1 to 3. [Figure 7] A table showing the characteristics of the buffer materials according to Comparative Examples 1 to 3. [Figure 8] A graph showing the results of measuring the cushioning performance of the buffer material according to the example. [Figure 9] A table showing the characteristics of the buffer material according to the example. [Figure 10]This graph shows the results of a simulation of the cushioning performance of the cushioning material related to Verification Example 1. [Figure 11] This table shows the characteristics of the cushioning material related to Verification Example 1. [Figure 12] This graph shows the results of simulations of the cushioning performance of the cushioning materials related to Verification Examples 2 through 7. [Figure 13] This table shows the characteristics of the cushioning materials related to verification examples 2 through 7. [Figure 14] This is a perspective view of the sole and shoe according to an embodiment. [Figure 15] Figure 14 is a side view of the sole of a shoe, seen from the outer side of the foot. [Figure 16] Figure 14 is a side view of the sole of the shoe, as seen from the inner side of the foot. [Figure 17] Figure 14 is a schematic plan view of the sole of a shoe. [Figure 18] Figure 14 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 plan view of the sole of a shoe according to the fourth modified example. [Figure 23] This is a schematic plan view of the sole of a shoe according to the fifth modified example. [Figure 24] This is a schematic plan view of the sole of a shoe according to the sixth modified example. [Figure 25] This is a schematic plan view of the sole of a shoe according to the seventh modified example. [Figure 26] 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 27] This is a schematic side view of the sole of the ninth modified shoe, as seen from the outer side of the foot. [Figure 28] This is a schematic side view of the sole of the tenth modified example, as seen from the outer side of the foot. [Figure 29] This is a schematic side view of the sole of the shoe according to the 11th modified example, as seen from the outer side of the foot. [Figure 30] This is a perspective view of a cushioning material having a structure similar to the cushioning material provided in the sole of a shoe according to the embodiment, and a perspective view of the unit structure constituting the cushioning material. [Figure 31] Figure 30 shows a plan view and a cross-sectional view of the cushioning material. [Figure 32] This graph shows the results of a simulation of the cushioning performance of the cushioning material related to Verification Example 8. [Figure 33] This table shows the characteristics of the cushioning material related to Verification Example 8. [Figure 34] This is a schematic side view of the sole of the 12th modified example, as seen from the outer side of the foot. [Figure 35] Figure 34 is a schematic bottom view of the outsole attached to the sole of the shoe. [Figure 36] This is a schematic side view of the sole of the 13th modified example, as seen from the outer side of the foot. [Figure 37] Figure 36 is a schematic bottom view of the insole provided in the sole of the shoe. [Modes for carrying out the invention]

[0013] 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.

[0014] Figure 1(A) is a perspective view of a cushioning material having a structure basically the same as the cushioning material provided in the sole of the embodiment, and Figure 1(B) is a perspective view of the unit structure constituting the cushioning material. Figure 2(A) is a plan view of the cushioning material shown in Figure 1(A) as seen 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 of the embodiment and the shoe equipped therewith, the structure of the cushioning material 1A having a structure similar to the cushioning material provided in the sole will be described with reference to Figures 1(A), 1(B), 2(A), 2(B), and 2(C).

[0015] As shown in Figures 1(A) and 2(A) to 2(C), the buffer 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.

[0016] 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.

[0017] 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.

[0018] 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.

[0019] 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.).

[0020] The cushioning material 1A according to this embodiment is designed to provide cushioning 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 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 1(A) and 2(A) to 2(C), three adjacent unit structures U in the width direction and depth direction are shown separately.

[0021] In this embodiment, a cushioning material 1A is provided as an example, comprising a large number of unit structures U in the width direction and depth direction. However, the number of repetitions of the unit structures U in the width direction and depth direction is not particularly limited. That is, the cushioning 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 cushioning material consisting of only one unit structure U.

[0022] The manufacturing method for the cushioning material 1A is not particularly limited, but the cushioning material 1A 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 cushioning 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 cushioning material 1A by molding using a mold, it becomes possible to manufacture the cushioning 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 cushioning materials with higher cushioning performance.

[0023] The material of the cushioning 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, if the cushioning material 1A is made of resin, it can be, for example, polyolefin resin, ethylene-vinyl acetate copolymer (EVA), polyamide-based thermoplastic elastomer (TPA, TPAE), thermoplastic polyurethane (TPU), or polyester-based thermoplastic elastomer (TPEE). 1A If it is made of rubber, for example, butadiene rubber can be used.

[0024] The buffer 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.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] 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).

[0029] 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.

[0030] Figures 3(A) and 3(B) schematically represent the buckling that may occur in the cushioning material shown in Figure 1(A). Next, the buckling that may occur in cushioning material 1A will be explained with reference to Figures 3(A) and 3(B). Note that the cross-section of cushioning 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).

[0031] As shown in Figure 3(A), for example, if the cushioning material 1A is sandwiched in the height direction (Z-axis direction shown in the figure) by 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 cushioning material 1A along the height direction, and as a result, the cushioning material 1A will undergo compressive deformation as shown in Figure 3(B). In this case, due to its structure, deformation will occur in the vertical wall portion 13 of the cushioning material 1A, and buckling will occur in the vertical wall portion 13 when a load above a certain level is applied.

[0032] On the other hand, when this pressure is released, the load applied to the cushioning material 1A along the height direction decreases and disappears, and consequently, the compressive deformation that had occurred in the cushioning material 1A is released, and the cushioning material 1A returns to its original shape. At this time, the buckling that had occurred in the cushioning material 1A is also eliminated.

[0033] Figure 4 is a graph showing the cushioning performance of the cushioning material shown in Figure 1, and Figure 5 is a graph showing the cushioning performance of a general cushioning material. The graphs shown in Figures 4 and 5 show the cushioning performance of the cushioning material. Occur This is a so-called stress-strain curve, which shows the correlation between stress and strain by plotting stress on the vertical axis and the strain of the cushioning material on the horizontal axis.

[0034] As described above, due to its structure, cushioning material 1A buckles during the loading process in which a load is applied and the load gradually increases. This compressive deformation of cushioning material 1A accompanied by buckling appears in the stress-strain curve as a characteristic curve as shown below.

[0035] In other words, as shown in Figure 4, in the initial stage of the loading process, stress σ increases with increasing strain ε, and consequently, the stress-strain curve slopes upward to the right. On the other hand, in the intermediate stage of the loading process, stress σ hardly changes even with increasing strain ε, and consequently, the stress-strain curve extends horizontally to the right. Finally, in the last stage of the loading process, stress σ increases with increasing strain ε, and consequently, the stress-strain curve slopes upward to the right again.

[0036] 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.

[0037] In other words, as shown in Figure 5, from the initial to the final stage of the loading process, stress σ always increases along with the increase in strain ε, and consequently, the stress-strain curve slopes upward to the right.

[0038] Here, as mentioned above, in order to improve the cushioning performance of the sole, at the point when the strain energy accumulated in the sole during landing is at its maximum, Occur It is effective to keep stress to a minimum. Strain energy is represented by the area enclosed between the stress-strain curve during the loading process and the horizontal axis (the area of ​​the shaded portion in the graphs shown in Figures 4 and 5), and the maximum strain energy accumulated in the sole of the shoe during landing is W max Therefore, W max It is expressed by the following equation (1). Note that ε max This refers to the distortion at the time the landing motion is completed (usually, the distortion is greatest at the time the landing motion is completed), and ε min This refers to the distortion at the start of the landing motion (normally, no distortion occurs at the start of this landing motion, and the distortion at that point is 0%).

[0039]

Number

[0040] Generally, among the shoe soles, the part where the largest load is applied during the landing motion is the part that supports the heel of the wearer's foot. Although the strain energy accumulated in this part varies depending on the wearer's body weight, body shape, walking style, etc., or the road surface condition, etc., it is approximately 5.0 [J]. In addition, the size and shape of the cushioning material that can be provided in the part of the shoe sole that supports the heel of the wearer's foot is a cylinder with a maximum diameter of 45 [mm] and a thickness of about 20 [mm], and its volume is approximately 31.8 [cm 3 .

[0041] Considering these points, at the time when the strain energy accumulated in the shoe sole during the landing motion reaches its maximum, the strain energy density of the cushioning material reaches approximately 0.157 [J / cm 3 . Therefore, if the time when the strain energy density of the cushioning material reaches 0.157 [J / cm 3 is set as the specific time point, it is important for improving the cushioning performance that the maximum value of the stress in the cushioning material is smaller until this specific time point is reached. Occur In this regard, the above-mentioned cushioning material 1A is caused by buckling during compression deformation, and its stress-strain curve has a region where the stress σ hardly changes even with an increase in the strain ε in the middle stage of the loading process. Therefore, if this buckling can be configured to start at a stress and strain of a predetermined magnitude, the maximum value of the stress in the cushioning material can be made smaller than that of a general cushioning material until the above-mentioned specific time point is reached, and as a result, high cushioning performance can be obtained.

[0042] In this regard, since the above-mentioned cushioning material 1A buckles during compression deformation and its stress-strain curve has a region where the stress σ hardly changes even with an increase in the strain ε in the middle stage of the loading process, if this buckling can be configured to start at a stress and strain of a predetermined magnitude, the maximum value of the stress in the cushioning material can be made smaller than that of a general cushioning material until the above-mentioned specific time point is reached, and as a result, high cushioning performance can be obtained. Occur the maximum value of the stress can be made smaller than that of a general cushioning material, and as a result, high cushioning performance can be obtained.

[0043] Here, in a general shoe sole, in the part that supports the heel of the wearer's foot during the landing motion OccurThe maximum stress varies depending on the wearer's weight, body shape, running style, and road surface conditions, but is generally around 0.15 MPa to 0.95 MPa. Therefore, from the perspective of suppressing this maximum stress, the cushioning material 1A described above must begin buckling in the range of approximately 0.15 MPa to 0.80 MPa. For convenience, in the following, this stress range of 0.15 MPa to 0.80 MPa, in which buckling is necessary to begin, will be referred to as the "required stress range."

[0044] In other words, in the case of a cushioning material that begins buckling at a stress smaller than the required stress range, it transitions to the intermediate stage of the loading process described above before the stress becomes considerably large. Therefore, by the time it reaches the specific point in time mentioned above, it has moved past the intermediate stage and transitioned to the final stage of the loading process described above, and the sole of the shoe becomes damaged. Occur If it is not possible to reduce the stress value at the above specific point in time, and if the cushioning material starts buckling at a stress greater than the required stress range, then buckling will not occur during running at all, and the sole of the shoe will not be able to buckle. Occur It is not expected that the stress value at the above-mentioned specific point in time can be reduced.

[0045] On the other hand, the deformation that occurs in the cushioning 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 cushioning material. However, considering that if the deformation is too small, cushioning performance will be almost eliminated, and if the deformation is too large, the sole of the shoe will sink too much, it is preferable that the deformation be approximately 10% to 60%. Therefore, the cushioning material 1A described above must begin to buckle within this deformation range. For convenience, in the following, this deformation range of 10% to 60% in which buckling is necessary will be referred to as the "required deformation range."

[0046] In addition, the aforementioned buckling, when small in degree, does not necessarily occur at the point when the strain energy accumulated in the sole of the shoe is at its maximum during the landing motion. Occur Stress is reduced doIt does not lead to results. In other words, at the point when the strain energy accumulated in the sole of the shoe during the landing motion is at its maximum, Occur In order to sufficiently reduce stress, it is necessary for the intermediate stages of the loading process described above to occur over a certain range of strain.

[0047] Furthermore, the maximum amount of strain energy accumulated in the sole of the shoe during landing varies not only from person to person, but also in various ways even for the same wearer, depending on running style, road surface conditions, etc. Therefore, taking this variability into account, in the intermediate stage of the aforementioned loading process where the stress σ hardly changes even with an increase in strain ε, the strain energy density of the cushioning material should be 0.157 [J / cm²]. 3 It is required to reach the above-mentioned specific point in time when [ ] is reached.

[0048] Taking these points into consideration, and given that the required stress range, which is the stress range in which buckling begins as described above, is 0.15 [MPa] to 0.80 [MPa], then the sole of the shoe... Occur In order to reduce the stress value at the above specific point in time, Compression force From the start of application until reaching the above-mentioned specific time, the cushioning material Occur The maximum stress (i.e., the maximum stress σ) max (See Figure 4)) The tangential modulus of elasticity of the cushioning material at the specified point in time must be 0.80 [MPa] or less, and the tangential modulus of elasticity of the cushioning material at the specified point in time must be 5.00 [MPa] or less. In other words, by satisfying these conditions, sufficient buckling will occur in the cushioning material during the loading process, and furthermore, variations caused by individual differences, running style, and road surface conditions will be absorbed, resulting in a shoe sole that can stably provide high cushioning performance.

[0049] Based on the points described above, the inventors conducted the following verification tests 1 to 4 to verify whether it is possible to realize a cushioning material that can be incorporated into the sole of a shoe to obtain high cushioning performance. The following will describe these verification tests 1 to 4 in order. For convenience, the point at which buckling begins during the loading process will be referred to as the "buckling initiation point" below.

[0050] <Verification Test 1> In Verification Test 1, several cushioning materials commonly used in shoe soles were prepared, and their cushioning performance was measured. A total of three types of cushioning materials were prepared (Comparative Examples 1 to 3), 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 1.00 [MPa].

[0051] Figure 6 is a graph showing the results of measuring the cushioning performance of the cushioning materials related to Comparative Examples 1 to 3, and Figure 7 is a table showing the characteristics of the cushioning materials related to Comparative Examples 1 to 3.

[0052] As shown in Figure 6, the stress-strain curves of all the cushioning materials in Comparative Examples 1 to 3 were similar to the stress-strain curve of the general cushioning material described above (see Figure 5). In particular, the cushioning material in Comparative Example 1 had the same stress-strain curve as the cushioning material 1A described above. distortion Due to the increase stress The loading process did not have a region where it changed very little.

[0053] On the other hand, in the cushioning materials relating to Comparative Examples 2 and 3, distortion Due to the increase stress There was a small region in the loading process where the stress remained almost unchanged. However, the buckling initiation points of the cushioning materials in Comparative Examples 2 and 3 were outside of both the required stress range and the required strain range mentioned above.

[0054] More specifically, as shown in Figure 7, the buckling initiation point for the cushioning material in Comparative Example 2 was calculated to be at a stress σ of 0.07 [MPa] and a strain ε of 6.6 [%], and the buckling initiation point for the cushioning material in Comparative Example 3 was calculated to be at a stress σ of 0.04 [MPa] and a strain ε of 2.5 [%]. The method for calculating the buckling initiation point will be explained in Verification Test 2, which will be described later.

[0055] Here, as shown in Figure 7, the maximum stress σ of the cushioning material for Comparative Examples 1 to 3 max The minimum was 0.84 [MPa] and the maximum was 0.94 [MPa], while the tangential modulus of elasticity of the cushioning materials related to Comparative Examples 1 to 3 at specific points in time was a minimum of 5.40 [MPa] and a maximum of 7.40 [MPa].

[0056] <Verification Test 2> In Verification Test 2, a cushioning material having the same structure as cushioning material 1A described above was actually manufactured by injection molding using a mold, and the cushioning performance of this cushioning material was measured. The manufactured cushioning material was one of the examples, and its stress-strain curve was obtained using a Shimadzu Autograph AGX-50kN as the measuring device. The test conditions were set to a compression rate of 1 [% / s] and a maximum pressure of 1.00 [MPa].

[0057] Figure 8 is a graph showing the results of measuring the cushioning performance of the cushioning material according to the example, and Figure 9 is a table showing the characteristics of the cushioning material according to the example. Here, in Figures 8 and 9, for comparison, the results of Comparative Example 3, which was confirmed to have the highest cushioning performance in the verification test 1 described above, are also included.

[0058] As shown in Figure 8, the stress-strain curve of the cushioning material according to the embodiment was similar to the stress-strain curve of cushioning material 1A described above (see Figure 4). In other words, the cushioning material according to the embodiment had a region in the loading process in which the stress σ hardly changed even with an increase in strain ε, similar to the stress-strain curve of cushioning material 1A described above.

[0059] Here, as shown in Figure 9, the maximum stress σ of the cushioning material according to the embodiment max The pressure was 0.59 [MPa], and the tangential modulus of elasticity of the cushioning material in this embodiment at a specific point in time was 1.35 [MPa].

[0060] The maximum stress σ of the cushioning material in this embodiment max The tangential elastic modulus at a specific point in time is the maximum stress σ of the cushioning material relating to Comparative Example 3. max Furthermore, it was found to be significantly lower than the tangential modulus of elasticity at a specific point in time, and it was confirmed that high cushioning performance can be obtained by using the cushioning material 1A with the above-described configuration.

[0061] Here, as shown in Figures 8 and 9, the buckling initiation point was calculated from the stress-strain curve of the cushioning material according to the embodiment. The method for calculating the buckling initiation point was as follows.

[0062] 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 order to reduce errors, various filtering methods may be applied as needed when calculating the buckling initiation point. The same method can also be used when calculating the buckling initiation point from the stress-strain curve obtained by the simulation described later.

[0063] As a result, it was calculated that the buckling initiation point of the cushioning material according to the embodiment is at a point where the stress σ is 0.55 [MPa] and the strain ε is 31.0 [%]. Here, as mentioned above, the buckling initiation point of the cushioning material according to Comparative Example 3 is at a point where the stress σ is 0.04 [MPa] and the strain ε is 2.5 [%], so it falls outside both the required stress range and the required strain range mentioned above (the same applies to the cushioning material according to Comparative Example 2). In contrast, it was confirmed that the buckling initiation point of the cushioning material according to the embodiment falls within both the required stress range and the required strain range mentioned above.

[0064] As shown in Figure 9, the specific gravity of the cushioning material in the example is 0.280 [g / cm³]. 3 ] and the specific gravity of the cushioning material related to Comparative Example 3 is (0.259 [g / cm³]. 3 It was also confirmed that the weight had been reduced to a level comparable to that of the previous version. In other words, it was confirmed that by using cushioning material 1A with the above configuration, not only is high cushioning performance obtainable, but the increase in weight can also be suppressed.

[0065] <Verification Test 3> In Verification Test 3, a simulation model roughly corresponding to the cushioning material of the above-described embodiment was created as Verification Example 1. By performing structural analysis of this model using the finite element method (FEM), the stress-strain curve of the cushioning material of Verification Example 1, which is based on the simulation model, was calculated, and its agreement with the stress-strain curve actually measured using the cushioning material of the embodiment was confirmed. The packing factor of the cushioning material of Verification Example 1 is 25%, and the modulus of elasticity of the base material is 14 MPa.

[0066] Figure 10 is a graph showing the simulation results of the cushioning performance of the cushioning material related to Verification Example 1, and Figure 11 is a table showing the characteristics of the cushioning material related to Verification Example 1. Here, in Figures 10 and 11, for comparison, the results of Comparative Example 3, which was confirmed to have the highest cushioning performance in the aforementioned Verification Test 1, are also included.

[0067] As shown in Figure 10, the stress-strain curve of the buffer material in Verification Example 1 was similar to the stress-strain curve of buffer material 1A described above (see Figure 4). In other words, the buffer material in Verification Example 1 had a region in the loading process in which the stress σ hardly changed even with an increase in strain ε, similar to the stress-strain curve of buffer material 1A described above.

[0068] Here, as shown in Figure 11, the maximum stress σ of the cushioning material related to Verification Example 1 maxThe tangential modulus of elasticity of the cushioning material in Verification Example 1 at a specific point in time was -0.16 [MPa]. The maximum stress σ of the cushioning material in Verification Example 1 was -0.16 [MPa]. max The tangential elastic modulus at a specific point in time is the maximum stress σ of the cushioning material according to the above-described embodiment. max Furthermore, it matches the tangential elastic modulus at a specific point in time, and the simulation method performed in verification test 3 is consistent with the maximum stress σ max Furthermore, it was confirmed that this method is generally valid for predicting the tangential elastic modulus at a specific point in time.

[0069] Furthermore, as shown in Figure 11, it was calculated that the buckling initiation point of the cushioning material in Verification Example 1 is at a point where the stress σ is 0.50 [MPa] and the strain ε is 24.0 [%]. This buckling initiation point of the cushioning material in Verification Example 1 also matches the buckling initiation point of the cushioning material in the above-described embodiment, confirming that the simulation method performed in Verification Test 3 is generally a valid method for predicting the buckling initiation point.

[0070] <Verification Test 4> In Verification Test 4, multiple simulation models of cushioning materials having a structure similar to that of cushioning material 1A described above were created, and structural analysis was performed using the finite element method (FEM) described above. The stress-strain curves and maximum stress σ of the cushioning materials derived from these simulation models were then obtained. max The tangential modulus of elasticity and the buckling initiation point at a specific point in time were calculated. In this study, the cushioning materials based on the simulation models created totaled six types in Verification Examples 2 through 7, and the only difference between the cushioning materials in Verification Examples 2 through 6 was their base material modulus.

[0071] Figure 12 is a graph showing the simulation results of the cushioning performance of the cushioning materials related to Verification Examples 2 to 7, and Figure 13 is a table showing the characteristics of the cushioning materials related to Verification Examples 2 to 7.

[0072] As shown in Figures 12 and 13, the stress-strain curves of the buffer materials in Verification Examples 2 to 7 were similar to the stress-strain curve of buffer material 1A described above (see Figure 4). In other words, the buffer materials in Verification Examples 2 to 7 had a region in the loading process in which the stress σ hardly changed even with an increase in strain ε, similar to the stress-strain curve of buffer material 1A described above.

[0073] However, in the case of the cushioning material related to Verification Example 2, which has a low modulus of elasticity of the base material, although the strain ε at the buckling initiation point is 19.0 [%], the stress σ at the buckling initiation point is 0.07 [MPa], and therefore the buckling initiation point does not fall within the required stress range mentioned above, resulting in the maximum stress σ max The pressure was 1.67 [MPa], and the tangential modulus of elasticity at that specific point in time was 30.07 [MPa]. It was confirmed that sufficient cushioning performance could not be obtained when this was applied to a shoe sole.

[0074] Furthermore, in the case of the cushioning 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 19.0 [%], the stress σ at the same buckling initiation point is 0.82 [MPa]. As a result, the buckling initiation point does not fall within the required stress range mentioned above, and therefore the maximum stress σ max The pressure was found to be 0.88 [MPa], and it was confirmed that this would not provide sufficient cushioning performance when applied to shoe soles.

[0075] On the other hand, for the cushioning materials in Verification Examples 3 to 5, whose base material modulus is between that of the cushioning material in Verification Example 2 and the cushioning material in Verification Example 6, the strain ε at the buckling initiation point is 19.0% in all cases. a Furthermore, since the stress σ at the buckling initiation points is 0.20 [MPa], 0.49 [MPa], and 0.66 [MPa] respectively, the buckling initiation points fall within both the required strain range and the required stress range mentioned above, and their maximum stress σ maxThe values ​​were 0.70 [MPa], 0.52 [MPa], and 0.71 [MPa], respectively. The tangential modulus of elasticity at specific points in time was 4.49 [MPa], -0.24 [MPa], and -0.47 [MPa], respectively. It was confirmed that high cushioning performance can be obtained when these are applied to shoe soles.

[0076] Furthermore, in the case of the cushioning material related to Verification Example 7, which has a low modulus of elasticity of the base material but a relatively high packing factor, the strain ε at the buckling initiation point was 42.0[%]. a Furthermore, since the stress σ at the buckling initiation point is 0.47 [MPa], the buckling initiation point falls within both the required strain range and the required stress range mentioned above, and therefore its maximum stress σ max The coefficient of elasticity was 0.50 [MPa], and the tangential modulus of elasticity at that specific point in time was 1.48 [MPa]. It was confirmed that applying this to a shoe sole would provide high cushioning performance.

[0077] <Summary of Verification Tests 1 through 4> Based on the results of verification tests 1 to 4 described above, Compression force The cushioning material has a three-dimensional shape formed by walls whose outer shape is defined by a pair of parallel planes, such that buckling may occur when a load is applied to it, and is configured such that buckling of the cushioning material begins in the aforementioned required strain range and required stress range when the load applied to the cushioning material is gradually increased, and furthermore, the cushioning material Compression force From the start of application until reaching the above-mentioned specific time, the cushioning material Occur It is understood that by keeping the maximum stress below the predetermined value mentioned above, and by keeping the tangential elastic modulus of the cushioning material at the specified point in time below the predetermined size mentioned above, unprecedentedly high cushioning performance can be obtained. For ease of understanding, the graph shown in Figure 12 shows the required strain range and required stress range mentioned above in darker colors.

[0078] Here, the cushioning 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.

[0079] For example, in the case of a cushioning material having a three-dimensional shape formed by walls whose outer shape is defined by a pair of parallel planes, similar to the cushioning 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.

[0080] 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 cushioning material with high cushioning performance can be created.

[0081] <Shoe soles and shoes according to embodiments, and shoe soles and shoes according to the first to eleventh modified examples> (Embodiment) Figure 14 is a perspective view of the sole and shoe according to this embodiment, and Figures 15 and 16 are side views of the sole shown in Figure 14, viewed from the outer and inner foot sides, respectively. Figure 17 is a schematic plan view of the sole shown in Figure 14, 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 14 to 18.

[0082] As shown in Figure 14, 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.

[0083] 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.

[0084] 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.

[0085] 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.

[0086] 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.

[0087] As shown in Figures 14 to 18, the sole 110A comprises a midsole 111 and an outsole 112 as the sole body, a high-rigidity plate 113 (see Figures 15 to 18), and a cushioning material 1. By assembling these midsole 111, outsole 112, high-rigidity plate 113, and cushioning material 1 together, the sole 110A has a generally flattened shape with an upper surface 110a and a lower surface 110b.

[0088] Here, the cushioning material 1 provided on the sole 110A has a basic structure similar to the cushioning material 1A described above, and is shown in a darker color in the diagram for ease of understanding. By providing this cushioning material 1 on the sole 110A, it becomes possible to create a sole and shoe with unprecedentedly high cushioning performance, but the details will be explained later.

[0089] 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 cushioning material 1 is also embedded in the midsole 111 by being housed in a notch 110d (see Figures 15, 16, and 18), which will be described later.

[0090] As shown in Figures 15 to 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 Figures 15 and 16, and 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.

[0091] 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.

[0092] 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).

[0093] As shown in Figures 14 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 the upper surface 111a and the lower surface 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.

[0094] 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.

[0095] 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.

[0096] 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.

[0097] Furthermore, multiple notches 110d are provided at predetermined positions on the periphery of the lower midsole portion 111B. Specifically, one notch 110d is provided in each of the following locations on the periphery of the lower midsole portion 111B: one that spans the position near the posterior end of the midfoot portion R2 on the outer side and the position on the outer side of the rearfoot portion R3; one that spans the position near the posterior end of the midfoot portion R2 on the inner side and the position on the inner side of the rearfoot portion R3; and one that spans the position near the posterior end of the forefoot portion R1 on the outer side and the position near the anterior end of the midfoot portion R2 on the outer side.

[0098] These multiple notches 110d are, as described above, parts for housing the cushioning material 1, and are provided so as to reach the upper surface, lower surface, and side surface of the lower midsole portion 111B. As a result, as will be described later, it becomes possible to directly position the high-rigidity plate 113 housed in the recess 110c and the cushioning material 1 housed in the notches 110d opposite each other without the midsole 111, and it also becomes possible to directly position the outsole 112 covering the lower surface 111b of the midsole 111 and the cushioning material 1 housed in the notches 110d opposite each other without the midsole 111, and furthermore, the cushioning material 1 can be exposed on the circumferential surface of the midsole 111.

[0099] The midsole 111 is made of a material with lower rigidity than the material constituting the cushioning 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 a foamed or non-foamed material such as polyolefin resin, ethylene-vinyl acetate copolymer (EVA), polyamide thermoplastic elastomer (TPA, TPAE), thermoplastic polyurethane (TPU), or polyester thermoplastic elastomer (TPEE).

[0100] 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.

[0101] As shown in Figures 14 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 made of a single component, or it may be made up of multiple components, as shown in Figure 18.

[0102] 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. The outsole 112 is positioned to cover the cushioning material 1 housed in the notch 110d of the midsole 111, and its upper surface is joined to the bottom surface 111b of the midsole 111 and the bottom surface of the cushioning material 1 by means of adhesive, for example. The lower surface of the outsole 112 that defines the bottom surface 110b of the sole 110A becomes the contact surface 112a.

[0103] 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.

[0104] As shown in Figures 15 to 18, the high-rigidity plate 113 is made of a single component and extends along the front-to-back 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 straddles the medial foot portion (S1 side portion) and the lateral foot portion (S2 side portion) of the sole 110A in the left-to-right direction, and is positioned in the front-to-back direction of the sole 110A, excluding the anterior end of the forefoot R1 and excluding the posterior end of the rearfoot R3. For ease of understanding, the high-rigidity plate 113 is lightly colored in Figures 15, 16, and 18, and the area where the high-rigidity plate 113 is positioned is lightly colored in Figure 17.

[0105] 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.

[0106] 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.

[0107] 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.

[0108] As shown in Figures 15 to 18, the cushioning material 1 has a basic structure similar to the cushioning 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.

[0109] Here, cushioning material 1 is modified in order to be fitted to the sole 110A, while maintaining the basic structure of the aforementioned cushioning material 1A, by slightly altering its shape (for example, the outer shape of the unit structure U when viewed in plan, as shown particularly in Figure 17), and is otherwise the same as the aforementioned cushioning material 1A.

[0110] The cushioning 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 direction normal to the contact surface 112a, which is the bottom surface 110b of the sole 110A.

[0111] As described above, the cushioning material 1 housed in the notch 110d faces the high-rigidity plate 113. As a result, the cushioning material 1 is fixed to the high-rigidity plate 113 by joining the upper wall portion 11 of the cushioning material 1 to the lower surface of the high-rigidity plate 113, for example by adhesive.

[0112] On the other hand, as described above, the lower surface of the cushioning material 1 housed in the notch 110d faces the outsole 112, and the cushioning material 1 is fixed to the outsole 112 by joining the lower wall portion 12 of the cushioning material 1 to the upper surface of the outsole 112, for example by adhesive.

[0113] In other words, the cushioning 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 held in place by being sandwiched between the high-rigidity plate 113 and the outsole 112.

[0114] As mentioned above, the notch 110d containing the cushioning material 1 extends to the side of the midsole 111. Consequently, the cushioning material 1 is exposed to the outside, and the open portion 14 (see Figures 15 and 16) formed on its side due to the structure of the cushioning material 1 is also located in an exposed position facing the outside.

[0115] Here, referring particularly to Figure 17, as described above, the cushioning material 1 is arranged in a total of three pieces, one each in the portion of the midsole 111's periphery that spans the posterior end of the midfoot R2 on the outer side and the posterior end of the rearfoot R3, the portion of the midsole 111's periphery that spans the posterior end of the midfoot R2 on the inner side and the posterior end of the rearfoot R3, and the portion of the midsole 111's periphery that spans the posterior end of the forefoot R1 on the outer side and the forefoot R2 on the outer side. Of these, the two cushioning materials 1 arranged in the portion that spans the midfoot R2 and rearfoot R3 are positioned along the portion Q1 that supports the heel of the wearer's foot, and the one cushioning material 1 arranged in the portion that spans the forefoot R1 and midfoot R2 is positioned along the wearer's foot Little toe ball It is located along the supporting portion Q2.

[0116] By configuring it in this way, the part Q1 that supports the heel of the wearer's foot, which is the part to which the greatest load is applied during landing, and the part of the wearer's foot to which a relatively large load is applied during landing Little toe ball Since the cushioning material 1 is placed in the supporting part Q2, the sole and shoe can be made to effectively achieve high cushioning performance.

[0117] In this case, although the cushioning material 1 retains essentially the same external shape even when inverted, inverting it causes a shift in the position of the surface irregularities. Therefore, it is necessary to determine the top and bottom of cushioning material 1 during manufacturing.

[0118] In order to obtain higher cushioning performance, the part Q1 that supports the heel of the wearer's foot and the wearer's foot Little toe ball It is preferable to configure the upper wall portion 11 of the cushioning material 1 to be located at a position corresponding to the portion Q2 that supports the cushioning material.

[0119] As described above, by using the sole 110A according to this embodiment and the shoe 100 equipped therewith, based on the high cushioning performance of the cushioning material 1, at the point when the strain energy accumulated in the sole 110A during landing is at its maximum, the sole 110A Occur Because it becomes possible to suppress stress to a much smaller degree, it is possible to create shoe soles and shoes equipped with them that have dramatically improved cushioning performance.

[0120] (Variations 1 through 7) Figures 19 to 25 are schematic plan views of the soles of the shoes according to the first to seventh modified examples, respectively. Hereinafter, the soles 110B to 110H according to the first to seventh modified examples based on the above-described embodiment will be explained with reference to Figures 19 to 25. These soles 110B to 110H according to the first to seventh modified examples are provided in the shoe 100 in place of the sole 110A according to the above-described embodiment.

[0121] As shown in Figures 19 to 25, the soles 110B to 110H according to the first to seventh modified examples differ from the sole 110A according to the above-described embodiment in that their configurations differ only in the position of the cushioning material 1 when viewed from above. Here, in Figures 19 to 25, for the sake of drawing convenience, the specific shape of the cushioning material 1 is not reproduced, and the area where the cushioning material 1 is placed is colored dark, while the area where the high-rigidity plate 113 is placed is colored light.

[0122] As shown in Figure 19, in the sole 110B according to the first modified example, only one cushioning material 1 is placed in a portion that spans the periphery of the midsole 111, specifically at a position near the posterior end of the midfoot R2 on the outer side, at the outer side of the rearfoot R3, at the posterior end of the rearfoot R3, at the medial side of the rearfoot R3, and near the posterior end of the midfoot R2 on the medial side. As a result, the cushioning material 1 is positioned along the portion Q1 that supports the heel of the wearer's foot.

[0123] Even with this configuration, the cushioning material 1 is placed in the part Q1 that supports the heel of the wearer's foot, which is the part to which the greatest load is applied during landing, thus making it possible to create a sole and shoe that can effectively provide high cushioning performance.

[0124] As shown in Figure 20, in the sole 110C according to the second modified example, only one cushioning material 1 is placed in the portion of the midsole 111 that spans the posterior end of the midfoot R2 and the hindfoot R3. As a result, the cushioning material 1 is positioned to completely overlap the portion Q1 that supports the heel of the wearer's foot.

[0125] Even with this configuration, the cushioning material 1 is placed in the part Q1 that supports the heel of the wearer's foot, which is the part to which the greatest load is applied during landing, thus making it possible to create a sole and shoe that can effectively provide high cushioning performance.

[0126] As shown in Figure 21, in the sole 110D according to the third modified example, only one cushioning material 1 is placed on the periphery of the midsole 111, spanning the position near the posterior end of the midfoot R2 on the outer side and the position on the outer side of the hindfoot R3. As a result, the cushioning material 1 is positioned along the portion Q1 that supports the heel of the wearer's foot.

[0127] Even with this configuration, the cushioning material 1 is placed in the part Q1 that supports the heel of the wearer's foot, which is the part to which the greatest load is applied during landing, thus making it possible to create a sole and shoe that can effectively provide high cushioning performance.

[0128] As shown in Figure 22, in the sole 110E according to the fourth modified example, two cushioning materials 1 are placed, one each at a position near the posterior end of the outer foot side of the forefoot R1 on the periphery of the midsole 111, and at a position near the posterior end of the inner foot side of the forefoot R1 on the periphery of the midsole 111. As a result, the cushioning material 1 placed near the posterior end of the outer foot side of the forefoot R1 provides support to the wearer's foot. Little toe ballThe cushioning material 1, located along the supporting portion Q2 and positioned near the posterior end of the medial side of the forefoot R1, is positioned along the support portion Q2 of the wearer's foot. ball of the big toe It is located along the supporting portion Q3.

[0129] Even with this configuration, the wearer's foot is the part that receives a relatively large load during landing. Little toe ball Supporting part Q2 and the wearer's foot ball of the big toe Since the cushioning material 1 is placed in the supporting part Q3, the sole and shoe can be made to effectively achieve high cushioning performance.

[0130] As shown in Figure 23, in the sole 110F according to the fifth modified example, only one cushioning material 1 is placed at the rear end of the forefoot R1 of the midsole 111. As a result, the cushioning material 1 is positioned on the wearer's foot Little toe ball Supporting part Q2 and the wearer's foot ball of the big toe It is located in complete overlap with the supporting portion Q3.

[0131] Even with this configuration, the wearer's foot is the part that receives a relatively large load during landing. Little toe ball Supporting part Q2 and the wearer's foot ball of the big toe Since the cushioning material 1 is placed in the supporting part Q3, the sole and shoe can be made to effectively achieve high cushioning performance.

[0132] As shown in Figure 24, in the sole 110G according to the sixth modified example, only one cushioning material 1 is placed at the rear end of the forefoot R1 of the midsole 111 and in the center in the width direction of the foot. As a result, the cushioning material 1 is positioned on the wearer's foot Little toe ball Supporting part Q2 and the wearer's foot ball of the big toe It is located along the supporting portion Q3.

[0133] Even with this configuration, the wearer's foot is the part that receives a relatively large load during landing. Little toe ball Supporting part Q2 and the wearer's foot ball of the big toe Since the cushioning material 1 is placed in the supporting part Q3, the sole and shoe can be made to effectively achieve high cushioning performance.

[0134] As shown in Figure 25, in the sole 110H according to the seventh modified example, only one cushioning material 1 is provided, spanning almost the entire forefoot R1, midfoot R2, and rearfoot R3 of the midsole 111. As a result, the cushioning material 1 supports the part Q1 that supports the heel of the wearer's foot, and the part of the wearer's foot Little toe ball Supporting part Q2 and the wearer's foot ball of the big toe It is located in complete overlap with the supporting portion Q3.

[0135] Even with this configuration, the part Q1 that supports the heel of the wearer's foot, which is the part to which the greatest load is applied during landing, and the part of the wearer's foot to which a relatively large load is applied during landing Little toe ball Supporting part Q2 and the wearer's foot ball of the big toe Since the cushioning material 1 is placed in the supporting part Q3, the sole and shoe can be made to effectively achieve high cushioning performance.

[0136] (Variations 8 through 11) Figures 26 to 29 are schematic side views of the soles of the eighth to eleventh modified examples, viewed from the outer foot side. The soles 110I to 110L of the eighth to eleventh modified examples based on the above-described embodiment will be described below with reference to Figures 26 to 29. These soles 110I to 110L of the eighth to eleventh modified examples are provided in the shoe 100 in place of the sole 110A of the above-described embodiment.

[0137] As shown in Figures 26 to 29, the soles 110I to 110L according to the eighth to eleventh modified examples all differ from the sole 110A according to the above-described embodiment in that the position of the cushioning 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 26 to 29, for the sake of drawing convenience, the specific shape of the cushioning material 1 is not reproduced, and the area where the cushioning material 1 is placed is colored dark, and the high-rigidity plate 113 is colored light. In these soles 110I to 110L according to the eighth to eleventh modified examples, the cushioning material 1 is located in the part that supports the heel of the wearer's foot when the midsole 111 is viewed from above. Q1 Only one is placed in a position that overlaps with it.

[0138] As shown in Figure 26, in the sole 110I according to the eighth 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 cushioning material 1 is positioned above the high-rigidity plate 113, rather than between the high-rigidity plate 113 and the outsole 112.

[0139] Specifically, the cushioning 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 110I, and its lower surface (i.e., lower wall portion 12) reaches the high-rigidity plate 113. Accordingly, the cushioning material 1 is fixed to the high-rigidity plate 113 by joining the lower wall portion 12 of the cushioning material 1 to the upper surface of the high-rigidity plate 113, for example by adhesive.

[0140] Even with this configuration, the cushioning material 1 is placed in the part Q1 that supports the heel of the wearer's foot, which is the part to which the greatest load is applied during landing, thus making it possible to create a sole and shoe that can effectively provide high cushioning performance.

[0141] As shown in Figure 27, in the sole 110J according to the ninth modified example, the position of the high-rigidity plate 113 is the same as in the sole 110A according to the above-described embodiment, whereas the cushioning 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 cushioning materials 1 is the same as that of the sole 110A according to the above-described embodiment and the sole 110I according to the eighth modified example.

[0142] Even with this configuration, the cushioning material 1 is placed in the part Q1 that supports the heel of the wearer's foot, which is the part to which the greatest load is applied during landing, thus making it possible to create a sole and shoe that can effectively provide high cushioning performance.

[0143] As shown in Figure 28, in the sole 110K according to the 10th 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 embodiment described above, and the arrangement position of the cushioning material 1 also differs from those of the sole 110A according to the embodiment described above.

[0144] Specifically, in the shoe sole 110K according to the 10th modified example, 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 shoe sole 110K.

[0145] The cushioning 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 cushioning 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 cushioning material 1 is joined to the upper surface of the lower high-rigidity plate 113B by means of adhesive, for example, and so the cushioning material 1 is fixed to this pair of upper high-rigidity plates 113A and lower high-rigidity plates 113B.

[0146] Even with this configuration, the cushioning material 1 is placed in the part Q1 that supports the heel of the wearer's foot, which is the part to which the greatest load is applied during landing, thus making it possible to create a sole and shoe that can effectively provide high cushioning performance.

[0147] As shown in Figure 29, in the 11th modified example, the sole 110L differs from the sole 110A in the above-described embodiment in that the midsole 111 has a different configuration from the sole 110A in the above-described embodiment, and it does not have a high-rigidity plate 113 (see Figure 15, etc.). Furthermore, the position of the cushioning material 1 differs from the sole 110A in the above-described embodiment, as described above.

[0148] Specifically, in the sole 110L according to the 11th modified example, the midsole 111 is made of a single component, and the cushioning material 1 is arranged so that it is exposed on both the upper surface 111a and the lower surface 111b of the midsole 111. As a result, the cushioning 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 110L, and its lower surface (i.e., lower wall portion 12) reaches the outsole 112. Accordingly, the cushioning material 1 is fixed to the outsole 112 by joining the lower wall portion 12 of the cushioning material 1 to the upper surface of the outsole 112, for example by adhesive.

[0149] Even with this configuration, the cushioning material 1 is placed in the part Q1 that supports the heel of the wearer's foot, which is the part to which the greatest load is applied during landing, thus making it possible to create a sole and shoe that can effectively provide high cushioning performance.

[0150] Figure 30(A) is a perspective view of a cushioning material having a structure similar to the cushioning material provided in the sole of the embodiment, and Figure 30(B) is a perspective view of the unit structure constituting the cushioning material. Figure 31(A) is a plan view of the cushioning material shown in Figure 30(A) as seen along the direction of arrow XXXIA shown in Figure 30(A), and Figures 31(B) and 31(C) are cross-sectional views along the lines XXXIB-XXXIB and XXXIC-XXXIC shown in Figure 31(A), respectively. The configuration of the cushioning material 1B having a structure similar to the cushioning material provided in the sole of the embodiment described above will be explained below with reference to Figures 30(A), 30(B), 31(A), 31(B), and 31(C).

[0151] As shown in Figures 30(A) and 31(A) to 31(C), the buffer 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 30(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.

[0152] 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.

[0153] In the unit structure U shown in Figure 30(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.

[0154] 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.

[0155] 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 30(A), etc.).

[0156] The cushioning material 1B according to this embodiment is designed to provide cushioning in the height direction as described above. Therefore, as shown in Figures 30(A) and 31(A) to 31(C), the multiple unit structures U are arranged regularly and continuously 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 30(A) and 31(A) to 31(C), three adjacent unit structures U in the width direction and depth direction are shown separately.

[0157] In this embodiment, a cushioning material 1B is described as an example, in which a large number of unit structures U are provided in the width direction and depth direction, respectively. However, the number of repetitions of the unit structures U in the width direction and depth direction is not particularly limited. That is, the cushioning 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 cushioning material consisting of only one unit structure U.

[0158] Furthermore, the manufacturing method and materials for cushioning material 1B can be the same as those described for cushioning material 1A.

[0159] In the cushioning material 1B configured in this way, as with the cushioning material 1A described above, compression 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 cushioning material 1B, and buckling occurs in the vertical wall portion 13 when a load exceeding a certain level is applied.

[0160] On the other hand, when this pressure is released, the load applied to the cushioning material 1B along the height direction decreases and disappears, and consequently, the compressive deformation that had occurred in the cushioning material 1B is released, and the cushioning material 1B returns to its original shape. At this time, the buckling that had occurred in the cushioning material 1B is also eliminated.

[0161] <Verification Test 5> In Verification Test 5, a simulation model corresponding to the aforementioned cushioning material 1B was created as Verification Example 8, and the stress-strain curve of the cushioning material related to Verification Example 8, which consists of the simulation model, was calculated by performing structural analysis on this model using the finite element method (FEM).

[0162] Figure 32 is a graph showing the simulation results of the cushioning performance of the cushioning material related to Verification Example 8, and Figure 33 is a table showing the characteristics of the cushioning material related to Verification Example 8. Here, in Figures 32 and 33, for comparison, the results of Comparative Example 3, which was confirmed to have the highest cushioning force in the aforementioned Verification Test 1, are also included.

[0163] As shown in Figure 32, the stress-strain curve of the buffer material in Verification Example 8 was similar to the stress-strain curve of buffer material 1A described above (see Figure 4). In other words, the buffer material in Verification Example 8 had a region in the loading process in which the stress σ hardly changed even with an increase in strain ε, similar to the stress-strain curve of buffer material 1A described above.

[0164] Here, as shown in Figure 33, the maximum stress σ of the cushioning material related to Verification Example 8 max The tangential modulus of elasticity was 0.43 [MPa], and the tangential modulus of elasticity of the cushioning material in Verification Example 8 at a specific point in time was -0.50 [MPa].

[0165] The maximum stress σ of the cushioning material related to this verification example 8 max The tangential elastic modulus at a specific point in time is the maximum stress σ of the cushioning material relating to Comparative Example 3. max Furthermore, it was found to be significantly lower than the tangential modulus of elasticity at a specific point in time, and it was confirmed that high cushioning performance can be obtained by using the cushioning material 1B with the above-described configuration.

[0166] Furthermore, it was calculated that the buckling initiation point of the cushioning material in Verification Example 8 is at a point where the stress σ is 0.39 [MPa] and the strain ε is 18.0 [%]. In other words, it was confirmed that the buckling initiation point of the cushioning material in Verification Example 8 falls within both the required stress range and the required strain range mentioned above.

[0167] <Summary of Verification Test 5> Based on the results of Verification Test 5 described above, the cushioning material is configured to have 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 is configured so that when the load applied to the cushioning material is gradually increased, buckling of the cushioning material begins within the required strain range and required stress range described above, and furthermore, the cushioning material Compression force From the start of application until reaching the above-mentioned specific time, the cushioning material Occur It is understood that by keeping the maximum stress below the predetermined value mentioned above, and by keeping the tangential elastic modulus of the cushioning material at the specified point in time below the predetermined size mentioned above, an unprecedentedly high level of cushioning performance can be obtained.

[0168] Here, the cushioning material 1B described above was constructed by dividing a Schwartz P structure unit in the height direction into two and then adding thickness to it. Other structures that can be used as triple-periodic minimal surface structures include gyroid structures and Schwartz D structures. By constructing a cushioning material by dividing these structural units in any of the three orthogonal axis directions into two and then adding thickness to them, a cushioning material with high cushioning force can be obtained.

[0169] <Shoe soles and shoes relating to the 12th and 13th variations> (12th variation) Figure 34 shows the sole of the 12th modified example viewed from the outer side of the foot. Side view Figure 35 is a schematic bottom view of the outsole provided on the sole of the shoe. Hereinafter, the sole 110M according to the 12th modified example based on the above-described embodiment will be described with reference to Figures 34 and 35. This sole 110M according to the 12th modified example is provided on the shoe 100 in place of the sole 110A according to the above-described embodiment.

[0170] As shown in Figure 34, the sole 110M according to the 12th modified example has a midsole 111 and an outsole 112, similar to the sole 110A according to the embodiment described above. However, it differs from the sole 110A according to the embodiment described above in that it does not have a high-rigidity plate 113 (see Figure 15, etc.) and does have an insole 114.

[0171] Specifically, the sole 110M relating to the 12th modified example consists of a midsole 111 and an outsole 112 as the sole body, and an insole 114 The sole 110M has the following characteristics, and in the case of the sole 110M, the cushioning material 1 is made up of a part of the outsole 112. In other words, the sole 110M does not have a cushioning material made of a single material, and instead a part of the outsole 112 is configured to function as a cushioning material.

[0172] 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 cushioning material 1, and has a substantially flattened shape with an upper surface 111a and a lower surface 111b.

[0173] As shown in Figures 34 and 35, 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 110M.

[0174] A portion that functions as the cushioning 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 cushioning 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. Thus, the outsole 112 portion that functions as the cushioning material 1 is the sole 110M The portion on the bottom surface 110b is positioned to be exposed to the outside. Furthermore, multiple openings 14 are located on the side of the outsole 112, which functions as cushioning material 1.

[0175] Here, the outsole 112, which functions as a cushioning 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 part that supports the heel of the wearer's foot Q1, the part that supports the wearer's foot Little toe ball Supporting part Q2 and the wearer's foot ball of the big toe It is positioned to include the supporting portion Q3.

[0176] 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.

[0177] figure 34 As shown, the insole 114 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 defines the top surface 110a of the sole 110M.

[0178] 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.

[0179] In the sole 110M described above, as mentioned above, the cushioning material 1 is composed of a part of the outsole 112, and based on the high cushioning performance of the outsole 112 in the part that functions as cushioning material 1, at the point when the strain energy accumulated in the sole 110M during landing is at its maximum, the cushioning material 1 is applied to the sole 110M. Occur This makes it possible to keep stress to a minimum. Therefore, by configuring it in this way, it is possible to create a shoe sole with dramatically improved cushioning performance and a shoe equipped with it.

[0180] (13th variation) Figure 36 shows the sole of the 13th modified example viewed from the outer side of the foot. Side view Figure 37 is a schematic bottom view of the insole provided in the sole of the shoe. Hereinafter, the sole 110N according to the 13th modified example based on the above-described embodiment will be described with reference to Figures 36 and 37. This sole 110N according to the 13th modified example is provided in the shoe 100 in place of the sole 110A according to the above-described embodiment.

[0181] As shown in Figure 36, the sole 110N according to the 13th modified example has a midsole 111 and an outsole 112, similar to the sole 110A according to the embodiment described above. However, it differs from the sole 110A according to the embodiment described above in that it does not have a high-rigidity plate 113 (see Figure 15, etc.) and does have an insole 114.

[0182] Specifically, the sole 110N according to the 13th modified example consists of a midsole 111 and an outsole 112 as the sole body, and an insole 114The sole 110N has the following features, and in this case, the cushioning material 1 is made up of a part of the insole 114. In other words, the sole 110N does not have a cushioning material made of a single component, and instead a part of the insole 114 is configured to function as a cushioning material.

[0183] 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 cushioning material 1, and has a substantially flattened shape with an upper surface 111a and a lower surface 111b.

[0184] 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 110N. The material of the outsole 112 is not particularly limited and can be made of various resin materials, rubber materials, etc.

[0185] As shown in Figures 36 and 37, 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 110N.

[0186] 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.

[0187] A portion that functions as the cushioning 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 insole 114 that functions as the cushioning 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 as described above. In addition, there are multiple open portions 14 that are exposed to the outside on the sides of the insole 114 that functions as the cushioning material 1.

[0188] Here, the insole 114, which functions as a cushioning material 1, is provided over almost the entire area of ​​the 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 part that supports the heel of the wearer's foot Q1, the part of the wearer's foot Little toe ball Supporting part Q2 and the wearer's foot ball of the big toe It is positioned to include the supporting portion Q3.

[0189] 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.

[0190] In the sole 110N described above, as mentioned above, the cushioning material 1 is composed of a part of the insole 114, and based on the high cushioning performance of the insole 114 that functions as this cushioning material 1, at the point when the strain energy accumulated in the sole 110N during landing is at its maximum, the sole 110N... Occur This makes it possible to keep stress to a minimum. Therefore, by configuring it in this way, it is possible to create a shoe sole with dramatically improved cushioning performance and a shoe equipped with it.

[0191] <Summary of Disclosures in Embodiments, etc.> The characteristic configurations disclosed in the embodiments described above and their variations can be summarized as follows:

[0192] [Note 1] A shoe sole that is equipped with cushioning 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 above-mentioned cushioning material has a three-dimensional shape formed by walls whose outer shape is defined by a pair of parallel planes or curved surfaces. The above cushioning material is arranged along the direction normal to the bottom surface. Compression force Buckling can occur when this is applied. Along the normal direction described above, the cushioning material Compression force When the load is gradually increased on the sole of the shoe so that the above-mentioned cushioning material is subjected to the following action: Occur Buckling of the cushioning material begins when the stress is in the range of 0.15 MPa to 0.80 MPa and the strain of the cushioning material in the normal direction is in the range of 10% to 60%, and the strain energy density of the cushioning material is 0.157 J / cm². 3 If the point in time when the above-mentioned cushioning material reaches a specific point in time, Compression force From the start of application until the above-mentioned specific time, the above-mentioned cushioning material Occur A shoe sole in which the maximum stress is 0.80 MPa or less, and the tangential modulus of elasticity of the cushioning material at the specified time is 5.00 MPa or less.

[0193] [Note 2] The sole of the shoe as described in Appendix 1, wherein the above-mentioned cushioning material is placed at least in the part that supports the heel of the wearer's foot.

[0194] [Note 3] The above cushioning material is for the wearer's feet Little toe ball The sole of a shoe as described in Appendix 1 or 2, which is positioned at least in the part that supports the shoe.

[0195] [Note 4] The above cushioning material is for the wearer's feet ball of the big toe A shoe sole as described in any of appendices 1 to 3, which is positioned at least in the part that supports the shoe.

[0196] [Note 5] The sole of a shoe according to any one of the appendices 1 to 4, wherein the cushioning 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.

[0197] [Note 6] The shoe sole described in Appendix 5 is constructed by dividing a structural unit consisting of multiple planes arranged intersectingly so as to have a cavity inside, in one of the three orthogonal axis directions, into two, and then adding thickness to each division.

[0198] [Note 7] The sole of a shoe as described in Appendix 6, wherein the above structural unit is one of the following structural units: Kelvin structure, octet structure, cubic structure, and cubic octet structure.

[0199] [Note 8] The shoe sole described in Appendix 5 is composed of the above-mentioned unit structure, which is made by dividing a structural unit of a triple-periodic minimal surface in one of its three orthogonal axis directions into two parts and then adding thickness to each part.

[0200] [Note 9] The sole of a shoe as described in Appendix 8, wherein the above structural unit is one of the following structural units: Schwartz P structure, Gyroid structure, and Schwartz D structure.

[0201] [Note 10] The cushioning material is made of a material with lower rigidity than the material that constitutes the cushioning material, and the midsole includes the top surface that defines the top surface, The above-mentioned midsole covers the underside and further comprises an outsole that defines the bottom surface, The sole of a shoe according to any one of the appendices 1 to 9, wherein the cushioning material is embedded in the midsole such that the upper surface of the cushioning material defines the top surface and the lower surface of the cushioning material reaches the outsole.

[0202] [Note 11] The cushioning material is made of a material with lower rigidity than the material that constitutes the cushioning material, and the midsole includes the top surface that defines the top surface, Furthermore, it is equipped with a high-rigidity plate made of a material with higher rigidity than the materials that make up the midsole, The above-mentioned high-rigidity plate is embedded in the midsole so as to extend in a direction intersecting the above-mentioned normal direction. The sole of a shoe according to any one of the appendices 1 to 9, wherein the cushioning material is embedded in the midsole such that the upper surface of the cushioning material defines the top surface and the lower surface of the cushioning material reaches the high-rigidity plate.

[0203] [Note 12] The cushioning material is made of a material with lower rigidity than the material that constitutes the cushioning material, and the midsole includes the top surface that defines the top surface, The outsole covers the underside of the midsole and defines the bottom surface, Furthermore, it is equipped with a high-rigidity plate made of a material with higher rigidity than the materials that make up the midsole, The above-mentioned high-rigidity plate is embedded in the midsole so as to extend in a direction intersecting the above-mentioned normal direction. The sole of a shoe according to any one of the appendices 1 to 9, wherein the cushioning material is embedded in the midsole such that the upper surface of the cushioning material reaches the high-rigidity plate and the lower surface of the cushioning material reaches the outsole.

[0204] [Note 13] The cushioning material is made of a material with lower rigidity than the material that constitutes the cushioning material, and the midsole includes the top surface that defines the top surface, The outsole covers the underside 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 that constitutes the midsole. The above-mentioned upper high-rigidity plate is positioned to cover the upper surface of the midsole so as to extend in a direction intersecting the above-mentioned 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 the appendices 1 to 9, wherein the cushioning material is embedded in the midsole such that the upper surface of the cushioning material reaches the upper high-rigidity plate and the lower surface of the cushioning material reaches the lower high-rigidity plate.

[0205] [Note 14] A midsole made of a material with lower rigidity than the material that makes up the cushioning material mentioned above, The midsole covers the lower surface and comprises an outsole that defines the bottom surface, The sole of a shoe according to any one of the appendices 1 to 9, wherein the above-mentioned cushioning material is composed of at least a portion of the above-mentioned outsole.

[0206] [Note 15] A midsole made of a material with lower rigidity than the material that makes up the cushioning material mentioned above, The above-mentioned midsole covers the upper surface and includes an insole that defines the top surface, The sole of a shoe as described in any of Appendix 1 to 9, wherein the above-mentioned cushioning material is composed of at least a portion of the above-mentioned insole.

[0207] [Note 16] The sole of the shoe as described in any of the appendices 1 to 15, A shoe comprising an upper provided above the sole.

[0208] <Other forms, etc.> In the embodiments and their modifications described above, the example described was one in which a cushioning material is provided on a part of the sole of the shoe, which has a midsole and an outsole. However, the entire sole may be made of cushioning material, or the cushioning material may be provided on a sole that does not have a midsole or an outsole.

[0209] Also, in the above-described embodiments and their modifications, the case where the cushioning material is configured to have not only the vertical wall portion but also the upper wall portion and the lower wall portion has been exemplified and described. However, the cushioning material may be configured to have neither or only one of the upper wall portion and the lower wall portion. That is, buckling that improves the cushioning performance mainly occurs in the vertical wall portion. Therefore, if the cushioning material can be assembled to the sole of the shoe by some method, the upper wall portion and the lower wall portion are not essential components.

[0210] Also, in the above-described embodiments and their modifications, the case where the cushioning material is configured by adding thickness to a structure unit of a geometric surface structure divided into two in any one of the three orthogonal axis directions has been exemplified and described. However, it is not necessarily required to have such a configuration. That is, the cushioning material is configured to have a three-dimensional shape formed by a wall whose outer shape is defined by a pair of parallel planes or curved surfaces, and buckling occurs in the cushioning material within the above-described required stress range and required strain range. As a result, while the above-described maximum stress becomes equal to or less than the above-described predetermined value, if the tangent elastic modulus of the cushioning material at the above-described specific time point is equal to or less than the above-described predetermined magnitude, any cushioning material may be used. Also, even in the case where the cushioning material is configured by adding thickness to a structure unit of a geometric surface structure divided into two in any one of the three orthogonal axis directions, modifications such as chamfering the corners, changing the thickness for each part, or slightly changing the shape of the unit structure body may be appropriately made.

[0211] Also, in the above-described embodiments and their modifications, the case where the present invention is applied to shoes provided with a shooter and a shoe lace has been exemplified and described. However, the present invention may be applied to shoes not provided with these (for example, shoes provided with a sock-shaped upper) and the soles provided thereto.

[0212] Furthermore, the characteristic configurations disclosed in the above-described embodiments and their modifications can be combined with each other without departing from the gist of the present invention.

[0213] Thus, the above-described embodiments and their modifications disclosed this time 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 description of the claims.

Description of Reference Numerals

[0214] 1, 1A, 1B Buffer material, 10 Wall, 11 Upper wall portion, 12, 12' Lower wall portion, 13 Standing wall portion, 14 Opening portion, 21 Upper member, 22 Lower member, 100 Shoe, 110A~110N Shoe sole, 110a Top surface, 110b Bottom surface, 110c Recess, 110d Notch, 111 Midsole, 111A Upper midsole portion, 111B Lower midsole portion, 111a Upper surface, 111b Lower surface, 112 Outsole, 112a Ground contact surface, 113 High-rigidity plate, 113A Upper high-rigidity plate, 113B Lower high-rigidity plate, 114 Insole, 114a Upper surface, 120 Upper, 121 Upper body, 122 Shoetop, 123 Shoelace, R1 Forefoot portion, R2 Midfoot portion, R3 Rearfoot portion, Q1 Portion indicating the heel, Q2 Little toe ball Portion supporting, Q3 ball of the big toe Portion supporting, S Three-dimensional structure, U Unit structure.

Claims

1. A shoe sole that is equipped with cushioning 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 cushioning material has a three-dimensional shape formed by walls whose outer shape is defined by a pair of parallel planes or curved surfaces. The cushioning material is such that 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 cushioning material is 12 MPa or more and 40 MPa or less. When a load is gradually increased on the sole of the shoe so that a compressive force is applied to the cushioning material along the normal direction, buckling of the cushioning material begins when the stress generated in the cushioning material is in the range of 0.15 MPa to 0.80 MPa and the strain of the cushioning material in the normal direction is in the range of 10% to 60%, and the strain energy density of the cushioning material is 0.157 J / cm². ３ A shoe sole in which, when the point at which a specific time is reached is defined as the point at which a specific time is reached, the maximum stress generated in the cushioning material from the start of applying compressive force to the cushioning material to reaching the specific time is 0.80 MPa or less, and the tangential modulus of elasticity of the cushioning material at the specific time is 5.00 MPa or less.

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

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

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

5. A shoe sole that is equipped with cushioning 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 cushioning material has a three-dimensional shape formed by walls whose outer shape is defined by a pair of parallel planes or curved surfaces. The cushioning material is such that buckling may occur when a compressive force is applied along the direction normal to the bottom surface. Notches are provided on the periphery of the sole, in a portion spanning the posterior end of the outer side of the midfoot and the outer side of the rearfoot, a portion spanning the posterior end of the inner side of the midfoot and the inner side of the rearfoot, and a portion spanning the posterior end of the outer side of the forefoot and the anterior end of the outer side of the midfoot. The cushioning material is housed in these notches, so that the cushioning material is positioned only along the portions of the sole where the notches are provided and which support the ball of the little toe and the heel of the wearer's foot. When a load is gradually increased on the sole of the shoe so that a compressive force is applied to the cushioning material along the normal direction, buckling of the cushioning material begins when the stress generated in the cushioning material is in the range of 0.15 MPa to 0.80 MPa and the strain of the cushioning material in the normal direction is in the range of 10% to 60%, and the strain energy density of the cushioning material is 0.157 J / cm². ３ A shoe sole in which, when the point at which a specific time is reached is defined as the point at which a specific time is reached, the maximum stress generated in the cushioning material from the start of applying compressive force to the cushioning material to reaching the specific time is 0.80 MPa or less, and the tangential modulus of elasticity of the cushioning material at the specific time is 5.00 MPa or less.

6. The sole of a shoe according to claim 1 or 5, wherein the cushioning 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.

7. The midsole is made of a material with lower rigidity than the material constituting the cushioning 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 claim 1 or 5, wherein the cushioning material is embedded in the midsole such that the upper surface of the cushioning material defines the top surface and the lower surface of the cushioning material reaches the outsole.

8. The midsole is made of a material with lower rigidity than the material constituting the cushioning 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 claim 1 or 5, wherein the cushioning material is embedded in the midsole such that the upper surface of the cushioning material defines the top surface and the lower surface of the cushioning material reaches the high-rigidity plate.

9. The midsole is made of a material with lower rigidity than the material constituting the cushioning 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 claim 1 or 5, wherein the cushioning material is embedded in the midsole such that the upper surface of the cushioning material reaches the high-rigidity plate and the lower surface of the cushioning material reaches the outsole.

10. The midsole is made of a material with lower rigidity than the material constituting the cushioning 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 claim 1 or 5, wherein the cushioning material is embedded in the midsole such that the upper surface of the cushioning material reaches the upper high-rigidity plate and the lower surface of the cushioning material reaches the lower high-rigidity plate.

11. A midsole made of a material with lower rigidity than the material constituting the cushioning material, The midsole covers the lower surface and comprises an outsole that defines the bottom surface, The sole of a shoe according to claim 1 or 5, wherein the cushioning material is composed of at least a portion of the outsole.

12. A midsole made of a material with lower rigidity than the material constituting the cushioning material, The midsole covers the upper surface and includes an insole that defines the top surface, The sole of a shoe according to claim 1 or 5, wherein the cushioning material is composed of at least a portion of the insole.

13. The sole according to claim 1 or 5, A shoe comprising an upper provided above the sole of the shoe.

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