Shoe sole cushioning material, shoe soles and shoes

Abstract

To provide a buffer material with excellent buffer performance.SOLUTION: A buffer material 1 includes a buffer part 10 which has a three-dimensional shape formed by walls 11 whose outline is defined by a pair of curved surfaces in parallel. The buffer part 10 includes at least one three-dimensional structure part 12 obtained by changing the shape of a unit structure U', which is based on the unit structure of the Schwarz P structure with thickness added to it. The shape of the three-dimensional structure part 12 in an unloaded condition is a shape obtained by changing the shape of the structure U', following a change of the shape of the unit space S', which is a regular hexahedron-shaped space occupied by the unit structure U', into to a pedestal-shaped space S.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention reduces the impact For shoe soles Cushioning material, For shoe soles The present invention relates to a shoe sole equipped with a cushioning material and a shoe equipped with the sole. [Background technology]

[0002] Various types of shock absorbers have been known for absorbing shock, and these various shock absorbers are used depending on the application. For example, in shoes, shock absorbers are sometimes provided on the soles of shoes to absorb the shock generated when landing. The shock absorbers provided on the soles of shoes are generally made of resin or rubber.

[0003] In recent years, shoes have been developed that have improved cushioning performance not only in terms of materials but also structurally by providing a portion of the sole with a lattice structure or web structure. For example, U.S. Patent Publication No. 2018 / 0049514 (Patent Document 1) discloses a shoe with a sole provided with a portion with a lattice structure.

[0004] On the other hand, JP 2017-527637 A (Patent Document 2) describes that three-dimensional objects can be manufactured using three-dimensional additive manufacturing methods, such as polyhedrons with internal cavities and triple-periodic minimal surfaces, with thickness added to the geometric surface structure, and discloses that by constructing the three-dimensional object from an elastic material, it can be applied to shoe soles, for example. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] U.S. Patent Publication No. 2018 / 0049514 [Patent Document 2] Special Publication No. 2017-527637 Summary of the Invention [Problem to be solved by the invention]

[0006] Generally, a property required of a cushioning material is that it tends to gradually increase in load when it is compressed and deformed. If the cushioning material has such a property, the cushioning material will be displaced stably as the externally applied load increases, thereby achieving excellent cushioning performance. For example, if a cushioning material having such a property is applied to the sole of a shoe, the shoe will be significantly more comfortable to wear.

[0007] Therefore, the present invention provides a cushioning device with excellent cushioning performance. For shoe soles To provide a cushioning material and a shoe sole and shoe provided with the same. [Means for solving the problem]

[0008] The inventors have found that a cushioning material made of an elastic material with a thickness based on the Schwarz P structure, which is one of the triple periodic minimal surface structures, has the property that when it is compressed and deformed, the load drops suddenly when the compressive displacement reaches a certain value. This property is not necessarily desirable when considering general uses as a cushioning material, and if this cushioning material is applied to shoe soles, for example, it may impair comfort.

[0009] In this regard, the inventor came up with the idea that the above-mentioned problem could be solved by changing the shape of the unit structure of the cushioning material, which is based on the Schwarz P structure but has been thickened, into a predetermined shape in an unloaded state, and thus completed the present invention.

[0010] The present invention The first phase of Based on For shoe soles The buffer material has a buffer section with a three-dimensional shape formed by a wall whose outline is defined by a pair of parallel curved surfaces. The buffer section includes at least one three-dimensional structural section obtained by changing the shape of a unit structure that is based on a unit structure of the Schwarz P structure and has added thickness to it. When the direction in which the buffer portion is intended to exert its buffering function by receiving a load is defined as the axial direction, The shape of the three-dimensional structure in an unloaded state is a unit space that is a regular hexahedron space occupied by the unit structure. Among the three pairs of opposing surfaces, each of the surfaces included in both of the two pairs of opposing surfaces excluding the pair of opposing surfaces located in the axial direction is inclined. When the shape is changed, the shape of the unit structure is changed to follow the change. A shoe sole cushioning material according to a second aspect of the present invention includes a cushioning section having a three-dimensional shape formed by walls whose outer shape is defined by a pair of parallel curved surfaces. The cushioning section includes at least one three-dimensional structural section obtained by deforming a unit structure obtained by adding thickness to a unit structure based on a Schwarz P structure. When the axial direction is defined as the direction in which the cushioning section is designed to exhibit its cushioning function when subjected to a load, the shape of the three-dimensional structural section in an unloaded state is a shape obtained by deforming the unit structure so as to follow the shape change of the unit space, which is a regular hexahedron-shaped space occupied by the unit structure, when each of the faces included in both of two pairs of opposing faces, excluding one pair of opposing faces located in the axial direction, is inclined.

[0011] The shoe sole according to the present invention is For shoe soles It is provided with a cushioning material.

[0012] A shoe according to the present invention comprises the above-described shoe sole according to the present invention and an upper provided above the sole. [Effects of the Invention]

[0013] According to the present invention, a cushioning material having excellent cushioning performance is provided. For shoe soles It is possible to provide a cushioning material and a shoe sole and shoe provided with the cushioning material. [Brief explanation of the drawings]

[0014] [Figure 1] 1A and 1B are perspective views of a three-dimensional structure of a cushioning material according to a first embodiment, and a perspective view of a unit structure in which a thickness is added based on a unit structure of a Schwarz P structure. [Figure 2] 2A to 2C are a front view, a left side view, a plan view, and a bottom view of a three-dimensional structure of a cushioning material according to embodiment 1. [Figure 3] 3 is a cross-sectional view of a three-dimensional structure of the cushioning material according to the first embodiment. FIG. [Figure 4] 1 is a perspective view of a cushioning material according to Comparative Example 1, and a graph showing the results of a simulation of the cushioning performance of the cushioning material. [Figure 5] 1 is a perspective view of a cushioning material according to Example 1, and a graph showing the results of a simulation of the cushioning performance of the cushioning material. [Figure 6] 10A and 10B are a perspective view, a front view, and a left side view of a cushioning material according to a second embodiment. [Figure 7]10A and 10B are a perspective view, a front view, and a left side view of a cushioning material according to a third embodiment. [Figure 8] FIG. 10 is a perspective view of a shoe sole and a shoe according to a second embodiment. [Figure 9] FIG. 10 is a side view of a shoe sole according to a second embodiment, as viewed from the outside of the foot. [Figure 10] FIG. 10 is a side view of a shoe sole according to a second embodiment, as viewed from the medial side of the foot. [Figure 11] 10 is a schematic plan view showing the arrangement positions of the cushioning materials in the sole of the shoe according to the second embodiment. FIG. [Figure 12] FIG. 10 is a perspective view of a cushioning material provided in a shoe sole according to a second embodiment. [Figure 13] 10 is an enlarged view of a main part of a cushioning material provided in a shoe sole according to a second embodiment. FIG. [Figure 14] FIG. 10 is a partial cross-sectional view of a shoe sole according to a second embodiment. [Figure 15] FIG. 10 is a perspective view showing a simulation model of the shoe soles according to Comparative Example 2 and Example 4. [Figure 16] 10 is a graph showing the results of a simulation of the shock-absorbing performance of the shoe soles according to Comparative Example 2 and Example 4. [Figure 17] FIG. 10 is a perspective view of a cushioning material provided in a shoe sole according to a first modified example. [Figure 18] FIG. 10 is a perspective view of a cushioning material provided in a shoe sole according to a second modified example. DETAILED DESCRIPTION OF THE INVENTION

[0015] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following embodiments, the same or common parts are designated by the same reference numerals in the drawings, and the description thereof will not be repeated.

[0016] (Embodiment 1) FIG. 1(A) is a perspective view of a three-dimensional structure of a cushioning material according to embodiment 1, and FIG. 1(B) is a perspective view of a unit structure obtained by adding thickness to a unit structure based on a Schwarz P structure. FIGS. 2(A) to 2(D) are a front view, left side view, plan view, and bottom view, respectively, of the three-dimensional structure of the cushioning material shown in FIG. 1(A), as viewed along the directions of arrows IIA to IID shown in FIG. 1(A). FIG. 3(A) is a cross-sectional view taken along line IIIA-IIIA shown in FIG. 2(B), and FIG. 3(B) is a cross-sectional view taken along line IIIB-IIIB shown in FIG. 2(A). Hereinafter, cushioning material 1 according to this embodiment will be described with reference to FIGS. 1 to 3.

[0017] As shown in Figures 1 to 3 (excluding Figure 1(B)), the cushioning material 1 has a cushioning section 10, which is the section that exhibits a cushioning function. The cushioning section 10 has a three-dimensional shape formed by walls 11 whose outer shape is defined by a pair of parallel curved surfaces, and has a geometric wall structure with an internal cavity. The cushioning section 10 includes at least one three-dimensional structural section 12 that has a shape in an unloaded state as shown in the figures.

[0018] 1(A), the unit space S occupied by the three-dimensional structural portion 12 is pedestal-shaped, and the unit space S is defined by a pair of opposing surfaces A1 and A2 located in the X-axis direction shown in the figure, a pair of opposing surfaces B1 and B2 located in the Y-axis direction shown in the figure, and a pair of opposing surfaces C1 and C2 located in the Z-axis direction shown in the figure. The buffer portion 10 of the buffer material 1 is designed to exhibit its buffering function by receiving a load in the X-axis direction, Y-axis direction, and Z-axis direction, particularly in the Z-axis direction.

[0019] The pair of opposing surfaces A1 and A2 located in the X-axis direction have the same size and shape in a plan view, and each is a trapezoid in which the length LT of one of a pair of sides extending in the Y-axis direction, which is the upper side, is shorter than the length LB of the other side, which is the lower side. The pair of opposing surfaces B1 and B2 located in the Y-axis direction have the same size and shape in a plan view, and both are rectangular. The pair of opposing surfaces C1 and C2 located in the Z-axis direction are both rectangular in a plan view, but the length LT of a pair of sides extending in the Y-axis direction of one surface C1 is shorter than the length LB of a pair of sides extending in the Y-axis direction of the other surface C2.

[0020] As a result, the unit space S is configured as a trapezoidal space in which a pair of opposing surfaces B1, B2 located in the Y-axis direction are inclined. Accordingly, the three-dimensional structure 12 has an end portion on the side where these opposing surfaces B1, B2 are located as an inclined end portion.

[0021] The ratio of the side lengths LT and LB is not particularly limited, but preferably satisfies the condition 1.1≦LT / LB≦4.0.

[0022] Each of the surfaces A1, A2, B1, B2, C1, and C2 included in the three pairs of opposing surfaces described above has an opening 13 located at the end of the three-dimensional structure 12. In Figures 1 to 3 (excluding Figure 1(B)), in order to make it easier to understand the shape of the three-dimensional structure 12, the end surfaces located in the X-axis direction, Y-axis direction, and Z-axis direction of the three-dimensional structure 12 are colored darkly to distinguish them from the other outer surfaces of the three-dimensional structure 12.

[0023] The three-dimensional structural portion 12 of the cushioning material 1 is a modified version of the unit structure U' of the reference cushioning material 1' shown in Figure 1(B), and in the unloaded state has the shape shown in Figures 1 to 3 (excluding Figure 1(B)).

[0024] As shown in Figure 1(B), the unit structure U' of the reference cushioning material 1' is a unit structure of the Schwarz P structure, which is a type of mathematically defined triply periodic minimal surface, to which thickness has been added. Note that a minimal surface is defined as a surface with the smallest area among those whose boundary is a given closed curve.

[0025] The unit space S' occupied by the unit structure U' has a regular hexahedron (cubic shape), and the unit space S' is defined by a pair of opposing surfaces A1', A2' located in the X-axis direction, a pair of opposing surfaces B1', B2' located in the Y-axis direction, and a pair of opposing surfaces C1', C2' located in the Z-axis direction. Each of the surfaces A1', A2', B1', B2', C1', and C2' included in these three pairs of opposing surfaces is a square in plan view.

[0026] The shape of the three-dimensional structural portion 12 of the cushioning material 1 in the unloaded state is a shape that can be obtained by changing the shape of the unit structure U' to follow the shape of the regular hexahedron-shaped unit space S' of the reference cushioning material 1' when the regular hexahedron-shaped unit space S' is changed into the trapezoidal unit space S as described above. More specifically, the shape of the three-dimensional structural portion 12 in the unloaded state is a shape that can be obtained by changing the shape of the unit structure U' to follow the shape of the regular hexahedron-shaped unit space S' of the reference cushioning material 1' when the regular hexahedron-shaped unit space S' is changed into a trapezoidal space by tilting each of the faces included in one pair of opposing faces B1, B2 located in the Y-axis direction out of the three pairs of opposing faces.

[0027] As described above, the buffer portion 10 of the buffer material 1 only needs to include at least one three-dimensional structural portion 12 having a shape in an unloaded state as shown in the drawing.

[0028] That is, when the buffer section 10 is composed of only one type of unit structure, the one type of unit structure may be composed of a three-dimensional structure 12 as shown in the figure, and in that case, the number of three-dimensional structures 12 may be one or more. When there are multiple three-dimensional structures 12, the multiple three-dimensional structures 12 may be repeatedly arranged along at least one of the X-axis direction, Y-axis direction, and Z-axis direction described above.

[0029] Furthermore, when the cushioning material 1 is composed of multiple types of unit structures, it is sufficient that one type of unit structure is composed of a three-dimensional structural portion 12 as shown in the figure, and in that case, the number of three-dimensional structural portions 12 may be one or multiple. When there are multiple three-dimensional structural portions 12, it is sufficient that the multiple three-dimensional structural portions 12 are repeatedly arranged along at least one of the above-mentioned X-axis, Y-axis, and Z-axis directions, with or without other types of unit structures sandwiched between them.

[0030] In addition to the buffer section 10, the buffer material 1 may further include a support section 20 (see FIG. 12, etc.), a fixing wall section 30 (see FIG. 12, etc.), reinforcing sections 40, 40', 40" (see FIG. 13, etc.), an extension section 50 (see FIG. 18), etc., which will be described later. In this case, these sections are provided adjacent to the buffer section 10 described above.

[0031] The method for manufacturing the cushioning material 1 is not particularly limited, but the cushioning material 1 can be manufactured by, for example, modeling using a three-dimensional additive manufacturing device.

[0032] The material of the buffer material 1 can basically be any material that has sufficient elasticity, but a resin material or a rubber material is preferable. More specifically, if the buffer material 1 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). On the other hand, if the buffer material 1 is made of rubber, it can be, for example, butadiene rubber.

[0033] The buffer material 1 can also be made of a polymer composition. In this case, examples of the polymer contained 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)), polypropylene, ethylene-propylene copolymers, propylene-1-hexene copolymers, propylene-4-methyl-1-pentene copolymers, propylene-1-butene copolymers, ethylene-1-hexene copolymers, ethylene-4-methyl-pentene copolymers, ethylene-1-butene copolymers, 1-butene-1-hexene copolymers, 1-butene-4-methyl-pentene, ethylene-methacrylic acid copolymers, ethylene-methyl methacrylate copolymers, ethylene-methacrylic acid ... Examples of the polyolefin include ethyl acrylate 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 propylene-vinyl acetate copolymer.

[0034] The polymer may be an amide polymer such as an amide elastomer or an amide resin, etc. Examples of the amide polymer include polyamide 6, polyamide 11, polyamide 12, polyamide 66, and polyamide 610.

[0035] The polymer may also be an ester-based polymer such as an ester-based elastomer or an ester-based resin, etc. Examples of the ester-based polymer include polyethylene terephthalate and polybutylene terephthalate.

[0036] The polymer may be a urethane polymer such as a urethane elastomer or a urethane resin, etc. Examples of the urethane polymer include polyester polyurethane and polyether polyurethane.

[0037] The polymer may also be a styrene-based polymer such as a styrene-based elastomer or a styrene-based resin. Examples of styrene-based 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-based resins include polystyrene, acrylonitrile-styrene resin (AS), and acrylonitrile-butadiene-styrene resin (ABS).

[0038] Furthermore, the polymer may be, for example, an acrylic polymer such as polymethyl methacrylate, a urethane-based acrylic polymer, a polyester-based acrylic polymer, a polyether-based acrylic polymer, a polycarbonate-based acrylic polymer, an epoxy-based acrylic polymer, a conjugated diene polymer-based acrylic polymer and hydrogenated products thereof, a urethane-based methacrylic polymer, a polyester-based methacrylic polymer, a polyether-based methacrylic polymer, a polycarbonate-based methacrylic polymer, an epoxy-based methacrylic polymer, a conjugated diene polymer-based methacrylic polymer and hydrogenated products thereof, a polyvinyl chloride resin, a silicone-based elastomer, butadiene rubber (BR), isoprene rubber (IR), chloroprene (CR), natural rubber (NR), styrene-butadiene rubber (SBR), acrylonitrile-butadiene rubber (NBR), butyl rubber (IIR), or the like.

[0039] The cushioning material 1 according to the present embodiment described above has excellent cushioning performance. This will be described in detail below based on the results of a first verification test conducted by the present inventors.

[0040] Fig. 4(A) is a perspective view of the cushioning material according to Comparative Example 1, and Fig. 4(B) is a graph showing the results of simulating the cushioning performance of the cushioning material according to Comparative Example 1. Fig. 5(A) is a perspective view of the cushioning material according to Example 1, and Fig. 5(B) is a graph showing the results of simulating the cushioning performance of the cushioning material according to Example 1.

[0041] In the first verification test, specific models of the cushioning materials according to Comparative Example 1 and Example 1 were designed, and the behavior of these models was analyzed individually by simulation, assuming that an external force was applied to each model in a predetermined direction. More specifically, a so-called load-displacement curve was obtained for each of these models.

[0042] 4(A), the cushioning material 1X according to Comparative Example 1 has a three-dimensional structure 12X whose shape in the unloaded state is obtained by stretching the regular hexahedral unit space S' of the reference cushioning material 1' described above only in the Z-axis direction, thereby changing the shape of the unit space into a rectangular parallelepiped, and then changing the shape of the unit structure U' to match this.On the other hand, the cushioning material 1A according to Example 1, like the cushioning material 1 according to the present embodiment described above, has a three-dimensional structure 12A whose shape in the unloaded state is obtained by changing the shape of the unit structure U' to match this when the regular hexahedral unit space S' of the reference cushioning material 1' described above is changed into a trapezoidal space.

[0043] More specifically, in the cushioning material 1X according to Comparative Example 1, the dimensions of the three-dimensional structural portion 12X as a unit structure in the X-axis direction and the Y-axis direction are each 10 mm, and the dimension of the three-dimensional structural portion 12X in the Z-axis direction is 20 mm. The thickness of the wall 11 of the three-dimensional structural portion 12X is 1.52 mm, and the material thereof is assumed to be a urethane-based acrylic polymer with an elastic modulus of 7.1 MPa.

[0044] On the other hand, in the cushioning material 1A according to Example 1, the dimensions of the three-dimensional structural portion 12A as a unit structure in the X-axis direction and the Z-axis direction are 10 mm and 20 mm, respectively, and the lengths LT and LB of the three-dimensional structural portion 12A shown in Fig. 1 are 10 mm and 20 mm, respectively. The thickness of the wall 11 of the three-dimensional structural portion 12A is 2.32 mm, and the material thereof is assumed to be a urethane-based acrylic polymer with an elastic modulus of 7.1 MPa.

[0045] The directions of the external force applied to the cushioning materials 1X and 1A according to Comparative Example 1 and Example 1 were a vertical direction (i.e., the Z-axis direction) and a diagonal direction (i.e., a direction perpendicular to the X-axis direction and intersecting both the Y-axis direction and the Z-axis direction). Note that Fig. 4(A) and Fig. 5(A) exemplarily illustrate a state in which four three-dimensional structures 12X and 12A are arranged along the X-axis direction.

[0046] 4(B), the cushioning material 1X according to Comparative Example 1 has a property that the load drops suddenly when the compressive displacement reaches a certain value, both when an external force is applied in the vertical direction and when an external force is applied in the oblique direction. This property is not necessarily preferable in consideration of general uses as a cushioning material, and for example, when the cushioning material 1X is applied to the soles of shoes, there is a risk that the comfort of wearing the cushioning material 1X may be impaired.

[0047] 5(B), the cushioning material 1A according to Example 1 has a property that the load gradually increases when an external force is applied in both a vertical direction and an oblique direction. This property is suitable when considering general uses as a cushioning material, and the cushioning material is stably displaced as the externally applied load increases. Therefore, if the cushioning material 1A is applied to the sole of a shoe, for example, the shoe can be made to be extremely comfortable to wear.

[0048] Therefore, by using the cushioning material 1 according to the present embodiment as described above, it is possible to obtain a cushioning material with excellent cushioning performance that can be used for various applications. When three-dimensional structures are arranged in a row as in the cushioning material 1A according to Example 1 described above, it is preferable that the directions (i.e., Z-axis directions) in which the cushioning function of each of the multiple three-dimensional structures is intended to be exerted are arranged approximately parallel to each other.

[0049] Fig. 6(A) is a perspective view of a cushioning material according to Example 2, and Fig. 6(B) and Fig. 6(C) are a front view and a left side view, respectively, of the cushioning material shown in Fig. 6(A) as viewed along the directions of arrows VIB and VIC shown in Fig. 6(A). Hereinafter, cushioning material 1B according to Example 2 will be described with reference to Fig. 6.

[0050] As shown in Figures 6(A) to 6(C), the cushioning material 1B according to Example 2 includes two types of three-dimensional structural members 12A and 12B as unit structures. Similar to the cushioning material 1 according to the present embodiment, the shapes of these two types of three-dimensional structural members 12A and 12B in the unloaded state are obtained by changing the shape of the unit structure U' to match the change in shape of the regular hexahedral unit space S' of the reference cushioning material 1' described above, into a trapezoidal space. However, the trapezoidal shape of the three-dimensional structural member 12B is the inverse of that of the three-dimensional structural member 12A in the Z-axis direction. The three-dimensional structural member 12A is the same as the three-dimensional structural member 12A included in the cushioning material 1A according to Example 1 described above.

[0051] In the cushioning material 1B according to Example 2, four three-dimensional structures 12A, 12B are arranged in rows along the X-axis direction, and these two rows of three-dimensional structures 12A, 12B are arranged in rows along the Y-axis direction. When arranged in this manner, the external shape of the cushioning material 1B is approximately a parallelogram when viewed along the X-axis direction (see FIG. 6(B)).

[0052] The cushioning material 1B configured in this manner can also be a cushioning material with excellent cushioning performance that can be used for a variety of applications, similar to the cushioning material 1 according to the present embodiment described above. When three-dimensional structures are arranged in a matrix in this manner, it is preferable that the directions (i.e., Z-axis directions) in which the cushioning function of each of the multiple three-dimensional structures is intended to be exerted are arranged approximately parallel to each other.

[0053] Fig. 7(A) is a perspective view of a cushioning material according to Example 3, and Fig. 7(B) and Fig. 7(C) are a front view and a left side view, respectively, of the cushioning material shown in Fig. 7(A) as viewed along the directions of arrows VIIB and VIIC shown in Fig. 7(A). Hereinafter, cushioning material 1C according to Example 3 will be described with reference to Fig. 7.

[0054] As shown in FIGS. 7A to 7C, the cushioning material 1C of Example 3 includes two types of three-dimensional structural members 12A and 12M as unit structures. Similar to the cushioning material 1 of the present embodiment, the three-dimensional structural member 12A has a shape in its unloaded state that is obtained by deforming the unit structure U' when the hexahedral unit space S' of the reference cushioning material 1' is transformed into a trapezoidal space. The remaining three-dimensional structural member 12M, unlike the cushioning material 1 of the present embodiment, has a shape in its unloaded state that is obtained by deforming the unit structure U' when the hexahedral unit space S' of the reference cushioning material 1' is transformed into a flattened rectangular parallelepiped unit space. The three-dimensional structural member 12A is the same as the three-dimensional structural member 12A included in the cushioning material 1A of Example 1.

[0055] In the cushioning material 1C according to Example 3, four three-dimensional structural portions 12A, 12M are arranged in rows along the X-axis direction, and one row including three-dimensional structural portion 12M is disposed between two rows including three-dimensional structural portion 12A, so that the three rows of three-dimensional structural portions 12A, 12M are arranged in a row in the Y-axis direction. When arranged in this manner, the overall external shape of cushioning material 1C is generally trapezoidal when viewed along the X-axis direction (see FIG. 7(B)).

[0056] The cushioning material 1C configured in this manner can also be a cushioning material with excellent cushioning performance that can be used for a variety of applications, similar to the cushioning material 1 according to the present embodiment described above. When three-dimensional structures are arranged in a matrix in this manner, it is preferable that the directions (i.e., Z-axis directions) intended to exhibit the cushioning function in each of the multiple three-dimensional structures are arranged approximately parallel to each other.

[0057] In the present embodiment described above, the shape of the three-dimensional structural parts 12, 12A in an unloaded state is explained as an example in which the shape of the unit structure U' is obtained by changing the shape of the unit space S', which is a regular hexahedron of the reference cushioning material 1', into a trapezoidal space by tilting each of the faces included in the pair of opposing faces B1, B2 located in the Y-axis direction out of the three pairs of opposing faces, but this can also be modified as appropriate.

[0058] For example, the shape of the three-dimensional structural part in an unloaded state may be such that when the regular hexahedron-shaped unit space S' of the reference cushioning material 1' is changed into a trapezoidal space by tilting not only the faces included in the pair of opposing surfaces B1 and B2 located in the Y-axis direction, but also each of the faces included in the pair of opposing surfaces A1 and A2 located in the X-axis direction, the shape of the unit structure U' is changed to follow this.Furthermore, in addition to this, when the pair of opposing surfaces C1 and C2 located in the Z-axis direction are changed into an approximately trapezoidal space by slightly tilting or curving these, the shape of the unit structure U' may be changed to follow this.

[0059] Regardless of the shape of the three-dimensional structure, it can be a cushioning material with excellent cushioning performance that can be used for various purposes, similar to the cushioning material 1 of this embodiment described above.

[0060] (Embodiment 2) Fig. 8 is a perspective view of a sole and a shoe according to embodiment 2. Figs. 9 and 10 are side views of the sole shown in Fig. 8 as seen from the lateral side and medial side, respectively. Fig. 11 is a schematic plan view showing the position of the cushioning material in the sole shown in Fig. 8. First, with reference to Figs. 8 to 11, the general configuration of a sole 110 according to this embodiment and a shoe 100 equipped with the same will be described.

[0061] As shown in Figure 8, shoe 100 includes a sole 110 and an upper 120. Sole 110 is a member that covers the sole of the foot and has a generally flat shape. Upper 120 has a shape that covers at least the entire instep side of the foot when inserted, and is located above sole 110.

[0062] The upper 120 has an upper body 121, a shoe tongue 122, and shoelaces 123. Of these, the shoe tongue 122 and the shoelaces 123 are both fixed or attached to the upper body 121.

[0063] An upper opening is provided at the top of upper body 121 to expose the top of the ankle and part of the instep. On the other hand, a lower opening is provided at the bottom of upper body 121, which is covered by sole 110, as one example, and as another example, the bottom is formed by sealing the lower end of upper body 121.

[0064] Shoe tongue 122 is fixed to upper body 121 by sewing, welding, bonding, or a combination of these, etc., so as to cover the portion of the upper opening provided in upper body 121 that exposes part of the instep. Upper body 121 and shoe tongue 122 are made from, for example, woven fabric, knitted fabric, nonwoven fabric, synthetic leather, resin, etc., and for shoes that require particular breathability and lightness, double raschel warp knit fabric made from woven polyester yarn is used.

[0065] The shoelace 123 is made of a string-like member that draws together the periphery of an upper opening that exposes part of the instep of the foot in the width direction, and is inserted through a plurality of holes that are provided around the periphery of the upper opening. By tightening the shoelace 123 with the foot inserted into the upper body 121, the upper body 121 can be fitted tightly to the foot.

[0066] As shown in FIGS. 8 to 11, the shoe sole 110 has a midsole 111 and an outsole 112 as the sole body, and cushioning materials 1D1 to 1D3.

[0067] The midsole 111 has an upper surface, a lower surface, and a side surface connecting the upper and lower surfaces, and constitutes the upper portion of the sole 110. The upper surface of the midsole 111 is joined to the upper 120.

[0068] It is preferable that the midsole 111 has a moderate strength and excellent cushioning properties, and from this viewpoint, the midsole 111 can be made of, for example, a resin or rubber member, and particularly preferably made of a foamed or non-foamed material such as polyolefin resin, ethylene-vinyl acetate copolymer (EVA), polyamide-based thermoplastic elastomer (TPA, TPAE), thermoplastic polyurethane (TPU), polyester-based thermoplastic elastomer (TPEE), etc.

[0069] The outsole 112 has an upper surface and a lower surface serving as a ground contact surface 112a, and constitutes the lower portion of the sole 110. The outsole 112 is mainly joined to the midsole 111.

[0070] The outsole 112 preferably has excellent abrasion resistance and grip, and from this viewpoint, the outsole 112 may be made of, for example, rubber. Note that a tread pattern may be provided on the ground surface 112a, which is the lower surface of the outsole 112, from the viewpoint of improving grip.

[0071] The cushioning materials 1D1 to 1D3 are arranged alongside the midsole 111 in a direction intersecting the thickness direction (Z-axis direction) of the sole body made up of the midsole 111 and the outsole 112, and more specifically, are arranged in cutout portions provided at predetermined positions in the midsole 111. As a result, the cushioning materials 1D1 to 1D3 are sandwiched between the midsole 111 and the outsole 112 in the thickness direction of the sole body. The cushioning materials 1D1 to 1D3 are bonded to the midsole 111 and the outsole 112 with an adhesive, as will be described later, and portions of them are positioned so as to be exposed on the circumferential surface of the sole 110.

[0072] As shown in Figures 9 to 11, the sole 110 is divided along the front-to-back direction (left-to-right direction in Figures 9 and 10, up-to-down direction in Figure 11), which is the direction that coincides with the longitudinal direction of the wearer's foot when viewed in a plane, into a forefoot portion R1 that supports the toes and forefoot of the wearer's foot, a midfoot portion R2 that supports the arch of the wearer's foot, and a rearfoot portion R3 that supports the heel of the wearer's foot.

[0073] Here, if the front end of the sole 110 is taken as the reference point, and the position corresponding to 40% of the longitudinal dimension of the sole 110 from the front end is taken as the first boundary position, and the position corresponding to 80% of the longitudinal dimension of the sole 110 from the front end is taken as the second boundary position, the forefoot R1 corresponds to the portion included between the front end and the first boundary position along the longitudinal direction, the midfoot R2 corresponds to the portion included between the first boundary position and the second boundary position along the longitudinal direction, and the rearfoot R3 corresponds to the portion included between the second boundary position and the rear end of the sole along the longitudinal direction.

[0074] Also, as shown in FIG. 11, the sole 110 is divided along the left-right direction (left-right direction in the drawing), which is the direction that matches the width direction of the wearer's foot when viewed in a plane, into an inner foot side portion (the S1 side portion shown in the drawing), which is the midline side (i.e., the side closer to the midline) of the anatomical orthogonal position of the foot, and an outer foot side portion (the S2 side portion shown in the drawing), which is the opposite side of the midline side of the anatomical orthogonal position of the foot (i.e., the side farther from the midline).

[0075] 8 to 11, the midsole 111 extends in the front-to-rear direction from the forefoot portion R1 to the rearfoot portion R3 via the midfoot portion R2. The outsole 112 includes a portion arranged to straddle the forefoot portion R1 and a position on the front side of the midfoot portion R2 in the front-to-rear direction, and a portion arranged to straddle the position on the rear side of the midfoot portion R2 in the front-to-rear direction and the rearfoot portion R3.

[0076] Cushioning material 1D1 is located along the edge of the sole 110 on the lateral side of the foot sole, spanning the portion of midfoot portion R2 closer to rearfoot portion R3 and rearfoot portion R3. Cushioning material 1D2 is located along the edge of the sole 110 on the medial side of the foot sole, spanning the portion of midfoot portion R2 closer to rearfoot portion R3 and rearfoot portion R3. Cushioning material 1D3 is located along the edge of the sole 110 on the lateral side of the foot sole, spanning the portion of forefoot portion R1 closer to midfoot portion R2 and the portion of midfoot portion R2 closer to forefoot portion R1.

[0077] Fig. 12 is a perspective view of the cushioning material provided in the shoe sole shown in Fig. 8, and Fig. 13 is an enlarged view of area XIII shown in Fig. 12. Next, the detailed configuration of the cushioning materials 1D1 to 1D3 will be described with reference to Figs. 12 and 13.

[0078] 12 and 13, cushioning materials 1D1 to 1D3 all have a configuration similar to that of cushioning material 1 according to the first embodiment described above, and include a cushioning section 10. The cushioning section 10 has a three-dimensional shape formed by walls 11 whose outer shape is defined by a pair of parallel curved surfaces, and includes a plurality of three-dimensional structural sections 12 as unit structures.

[0079] Each of the multiple three-dimensional structures 12 has a shape that is obtained by changing the shape of the unit structure U' so that it follows the change in shape of the regular hexahedral unit space S' (see FIG. 1(A)) of the reference cushioning material 1' into a trapezoidal space. In each of the cushioning materials 1D1 to 1D3, the multiple three-dimensional structures 12 are arranged in a row in a direction along the edge of the sole 110.

[0080] Here, each of the multiple three-dimensional structures 12 is provided so that the direction (i.e., the Z-axis direction) intended to exhibit the buffering function faces a direction perpendicular to the ground contact surface 112a of the outsole 112. With this configuration, the load applied to the sole 110 from the sole of the foot and the ground when landing is absorbed by the buffering section 10 including the three-dimensional structures 12 deforming with a large amount of displacement, reducing the load applied to the sole from the sole 110 and achieving high buffering performance.

[0081] Each of the cushioning materials 1D1 to 1D3 includes, in addition to the above-described cushioning section 10, a support section 20 and a fixing wall section 30. The support section 20 and the fixing wall section 30 are both configured in a plate shape and are provided adjacent to and integral with the cushioning section 10. In other words, the cushioning materials 1D1 to 1D3 are made of a single member formed so that the cushioning section 10, support section 20, and fixing wall section 30 are continuously connected.

[0082] The support section 20 is provided so as to be positioned in a direction (i.e., the Z-axis direction) in which each of the multiple three-dimensional structural sections 12 of the cushioning materials 1D1 to 1D3 is intended to exhibit its cushioning function, and includes an upper support section 21 on the side where the upper 120 is located as viewed from the cushioning section 10, and a lower support section 22 on the side where the outsole 112 is located as viewed from the cushioning section 10. As a result, the cushioning section 10 is positioned sandwiched between the upper support section 21 and the lower support section 22.

[0083] The upper support portion 21 has a plurality of through holes 21a. These through holes 21a correspond to and communicate with the openings 13 located on the end surface of each of the plurality of three-dimensional structures 12 facing the upper support portion 21. Meanwhile, the lower support portion 22 also has a plurality of through holes 22a (see FIG. 14(A)). These through holes 22a correspond to and communicate with the openings 13 located on the end surface of each of the plurality of three-dimensional structures 12 facing the lower support portion 22.

[0084] The fixing wall 30 is provided so as to be positioned in a direction intersecting the direction (i.e., the Z-axis direction) in which each of the plurality of three-dimensional structures 12 of the cushioning materials 1D1 to 1D3 is intended to exhibit its cushioning function, and more specifically, is provided in a portion of the cushioning materials 1D1 to 1D3 other than the portion exposed on the circumferential surface of the sole 110. As a result, the end face of the circumferential surface of the cushioning unit 10 that is positioned on the midsole 111 side is covered by the fixing wall 30.

[0085] The fixing wall 30 has a second opposing surface 31, which is its exposed surface. The fixing wall 30 is also provided with a plurality of through holes 32. These through holes 32 include holes that correspond to and communicate with the openings 13 located on the end faces of the fixing wall 30 side of each of the three-dimensional structural portions 12. The plurality of through holes 32 also includes a plurality that do not correspond to the openings 13 described above and communicate with the space surrounding the three-dimensional structural portion 12 (these through holes 32 will be described in detail later).

[0086] The plurality of through holes 21a, 22a, 32 provided in the upper support portion 21, the lower support portion 22, and the fixing wall portion 30 mainly serve as outlets for discharging uncured resin during manufacturing of the cushioning materials 1D1-1D3 using the above-described three-dimensional additive manufacturing method. In other words, because the through holes 21a, 22a, 32 communicate with the space inside the three-dimensional structure 12 of the cushioning section 10 and the space surrounding the three-dimensional structure 12, uncured resin can be discharged through the through holes 21a, 22a, 32 during manufacturing, making it possible to form the cushioning section 10 in a desired shape with high dimensional accuracy.

[0087] The above-mentioned upper support portion 21 and fixing wall portion 30 are both portions fixed to the midsole 111, and the above-mentioned lower support portion 22 is a portion fixed to the outsole 112. In other words, since the buffer section 10 made up of a plurality of three-dimensional structural portions 12 has a geometric wall structure as described above, if this were fixed as is by directly adhering it to the midsole 111 or the outsole 112, the deformation of these three-dimensional structural portions 12 would be hindered, and the desired buffer performance would not be obtained.

[0088] In this regard, by providing these upper support portion 21, lower support portion 22 and fixing wall portion 30 integrally with the buffer portion 10, it becomes possible to fix the buffer materials 1D1 to 1D3 to the midsole 111 and outsole 112 by adhesive while preventing the deformation of the multiple three-dimensional structural portions 12 from being hindered, thereby achieving the desired buffer performance.

[0089] Figures 14(A) and 14(B) are partial cross-sectional views of the shoe sole shown in Figure 8. Next, the assembly structure of the cushioning materials 1D1 to 1D3 in the shoe sole 110 according to this embodiment will be described in detail with reference to Figure 14. Note that while Figure 14 representatively illustrates the assembly structure of the cushioning material 1D1, the assembly structures of the cushioning materials 1D2 and 1D3 are similar.

[0090] Here, Fig. 14(A) is a cross-sectional view of a portion of the sole 110 including the through-holes 32 (in the drawing, the through-holes are particularly indicated by the reference numeral 32(13)) that correspond to and communicate with the openings 13 located on the end face of each of the plurality of three-dimensional structural portions 12 on the side of the fixing wall portion 30. On the other hand, Fig. 14(B) is a cross-sectional view of a portion of the sole 110 including the through-holes 32 (in the drawing, the through-holes are simply indicated by the reference numeral 32) that communicate with the space surrounding the three-dimensional structural portion 12.

[0091] 14(A) and 14(B), the cushioning material 1D1 is fixed to the midsole 111 and the outsole 112 via an adhesive layer 113. Specifically, the cushioning material 1D1 has its upper support portion 21 bonded to an upper wall surface of a cutout portion provided in the midsole 111 via the adhesive layer 113, and its fixing wall portion 30 bonded to a lateral wall surface of the cutout portion provided in the midsole 111 via the adhesive layer 113. Furthermore, the cushioning material 1D1 has its lower support portion 22 bonded to the upper surface of the outsole 112 via the adhesive layer 113.

[0092] More specifically, the upper wall surface of the cutout portion of midsole 111 and the upper surface of upper support portion 21 are both configured to be approximately flat, and these surfaces are bonded together with adhesive layer 113, thereby fixing cushioning material 1D1 and midsole 111 in this portion. Also, as shown in Figure 14(A), upper support portion 21 has a plurality of through holes 21a as described above, and portions of adhesive layer 113 penetrate these plurality of through holes 21a. This increases the bonding area and provides a kind of anchor effect, thereby increasing the bonding strength in this portion.

[0093] The upper surface of the outsole 112 and the lower surface of the lower support part 22 are both configured to be approximately flat, and an adhesive layer 113 is bonded between these surfaces, thereby fixing the cushioning material 1D1 and the outsole 112 in this area. As shown in Fig. 14(A), the lower support part 22 has a plurality of through holes 22a as described above, and portions of the adhesive layer 113 penetrate into these plurality of through holes 22a. This increases the bonding area and provides a kind of anchor effect, thereby increasing the bonding strength in this area.

[0094] Furthermore, the first opposing surface 111a, which is the wall surface on the side of the cutout portion of the midsole 111, and the second opposing surface 31, which is the outer surface of the fixing wall portion 30, are both configured to be approximately flat, and an adhesive layer 113 is bonded to these surfaces, thereby fixing the cushioning material 1D1 and the midsole 111 in this portion. As shown in FIG. 14(A), the fixing wall portion 30 is provided with a plurality of through holes 32(13) as described above, and portions of the adhesive layer 113 penetrate into the plurality of through holes 32(13). Additionally, as shown in FIG. 14(B), the fixing wall portion 30 is also provided with a plurality of through holes 32 as described above, and portions of the adhesive layer 113 also penetrate into the plurality of through holes 32(13). This increases the bonding area and provides a kind of anchor effect, thereby increasing the bonding strength in this portion.

[0095] As a result, upper support portion 21, lower support portion 22, and fixing wall portion 30 are firmly fixed to midsole 111 and outsole 112, effectively preventing cushioning materials 1D1 to 1D3 from peeling off from midsole 111 and outsole 112. Furthermore, by providing multiple through-holes 21a, 22a, 32 in upper support portion 21, lower support portion 22, and fixing wall portion 30, the bonding strength in these portions is increased, resulting in a sole 110 with even greater durability, and a shoe 100 equipped with the sole.

[0096] 14(A) and 14(B), in the sole 110 according to this embodiment, the first opposing surface 111a, which is the wall surface on the side of the cutout portion of the midsole 111, is inclined relative to the direction perpendicular to the ground contact surface 112a (i.e., the thickness direction (Z-axis direction) of the sole body consisting of the midsole 111 and the outsole 112), and more specifically, is inclined so that its lower end is located inside the sole body and its upper end is located outside the sole body. Meanwhile, the fixing wall 30 of the cushioning material 1D1 is inclined relative to the thickness direction of the sole body so that its second opposing surface 31 is parallel to the first opposing surface 111a.

[0097] The fixing wall portion 30, which is inclined with respect to the thickness direction of the sole body, can be formed by each of the multiple three-dimensional structural portions 12 included in the buffer portion 10 being composed of a unit structure with the unit space S being a platform-shaped space as described above, and by arranging the multiple three-dimensional structural portions 12 in a row along the fixing wall portion 30 so that the above-mentioned inclined ends of the multiple three-dimensional structural portions 12 are each connected to the fixing wall portion 30.

[0098] In this way, since the boundary between the midsole 111 and the cushioning material 1D1 is inclined relative to the thickness direction of the sole body, the rigidity in the thickness direction of the sole body at that portion can be significantly reduced compared to when the fixing wall portion 30 of the cushioning material 1D1 is arranged parallel to the thickness direction of the sole body.

[0099] Therefore, by configuring it in this manner, it is possible to effectively prevent the boundary between the midsole 111 and the cushioning material 1D1 from becoming more rigid than the surrounding area, resulting in a sole 110 and a shoe 100 equipped with the sole that are highly comfortable to wear.

[0100] Here, as shown in Figures 12 to 14 (particularly Figures 13, 14(A) and 14(B)), in the sole 110 of this embodiment, the cushioning materials 1D1 to 1D3 include reinforcing portions 40, 40', 40" in addition to the above-mentioned cushioning portion 10, upper support portion 21, lower support portion 22 and fixing wall portion 30.

[0101] More specifically, in the sole 110, when viewed along the thickness direction of the sole body, which is a direction perpendicular to the ground contact surface 112a (i.e., the Z direction shown in the figure), the lower support part 22 has a protruding region that protrudes outward from the end of the three-dimensional structure part 12 on the side of the lower support part 22. If no measures are taken, this protruding region will have extremely low rigidity compared to the surrounding area and will be easily deformed by the application of an external force, which may result in the part being damaged relatively early due to repeated use, etc.

[0102] 13 and 14(A), in the sole 110 according to the present embodiment, in order to suppress deformation of the lower support part 22 in the protruding region, a reinforcing part 40 is provided to connect the part of the three-dimensional structure 12 near the end of the lower support part 22 to the part of the lower support part 22 that corresponds to the protruding region. This reinforcing part 40 is formed by filling part of the space surrounding the periphery of the three-dimensional structure 12, and the formation of this reinforcing part 40 increases the rigidity of that part, making it possible to suppress excessive deformation of the part of the lower support part 22 that corresponds to the protruding region.

[0103] Therefore, by adopting this configuration, it is possible to obtain a sole 110 with excellent durability and a shoe 100 equipped with the same. Note that the reinforcing portion 40 also has the secondary function of suppressing excessive compressive deformation of the buffer portion 10, and therefore, when this configuration is adopted, it is possible to obtain a sole 110 with excellent durability and a shoe 100 equipped with the same in this respect as well.

[0104] 13 and 14(A), the reinforcing portion 40' is provided so as to connect the upper support portion 21 to a portion of the three-dimensional structure 12 near the end thereof on the upper support portion 21 side. This reinforcing portion 40' is also formed by filling in part of the space surrounding the three-dimensional structure 12, similar to the reinforcing portion 40 described above. When configured in this manner, it is possible to prevent the buffer portion 10 from being excessively compressed and deformed, resulting in a highly durable shoe sole 110 and a shoe 100 equipped with the sole.

[0105] Furthermore, as shown in Figures 13 and 14(B), the reinforcing portion 40" is formed by filling in part of the space surrounding the three-dimensional structural portion 12 so as to connect adjacent three-dimensional structural portions 12. When configured in this manner, even when an external force is applied to the cushioning material 1D1 in a direction parallel to the ground surface 112a, excessive compressive deformation of the cushioning material 1D1 can be suppressed, resulting in a highly durable sole 110 and a shoe 100 equipped with the sole.

[0106] Figures 15(A) and 15(B) are perspective views showing simulation models of the shoe soles according to Comparative Example 2 and Example 4, respectively, and Figure 16 is a graph showing the results of simulating the shock-absorbing performance of the shoe soles according to Comparative Example 2 and Example 4. Next, with reference to Figures 15 and 16, a second verification test conducted by the present inventor to confirm the effect obtained by inclining the fixing wall portion 30 described above with respect to the thickness direction of the sole body will be described in detail.

[0107] In the second verification test, specific simulation models of the shoe soles according to Comparative Example 2 and Example 4 were created, and the behavior of these simulation models was analyzed individually by simulation, assuming that an external force was applied to each of these simulation models in a predetermined direction. More specifically, a so-called load-displacement curve was obtained for each of these simulation models at the boundary between the midsole and the cushioning material.

[0108] Here, as shown in Figure 15(A), in the simulation model 110Y of the shoe sole according to Comparative Example 2, a cushioning material 1Y was used that has a three-dimensional structural portion 12Y whose shape in an unloaded state is obtained by stretching the regular hexahedral unit space S' of the reference cushioning material 1' described above in the Y-axis direction and then slightly stretching it in the Z-axis direction, thereby changing the shape of the unit space to a rectangular parallelepiped, and then changing the shape of the unit structure U' to follow this.

[0109] This cushioning material 1Y includes an upper support portion 21 and a fixing wall portion 30, and the fixing wall portion 30 is configured as a vertical wall parallel to the thickness direction of the sole body. As a result, the second opposing surface 31 (see FIG. 14) provided on the fixing wall portion 30 is configured as a surface parallel to the thickness direction of the sole body, and accordingly, the first opposing surface 111a (see FIG. 14), which is the wall surface on the side of the cutout portion of the midsole 111, is also configured as a surface parallel to the thickness direction of the sole body.

[0110] On the other hand, as shown in Figure 15(B), in the simulation model 110A of the shoe sole of Example 4, similar to the cushioning material 1 of the above-mentioned embodiment 1, a cushioning material 1E was used that has a three-dimensional structural portion 12E whose shape in an unloaded state is obtained by changing the shape of the unit structure U' to follow the change in shape of the regular hexahedral unit space S' of the above-mentioned reference cushioning material 1' into a trapezoidal space.

[0111] This cushioning material 1E includes an upper support portion 21 and a fixing wall portion 30, and the fixing wall portion 30 is configured as a wall inclined with respect to the thickness direction of the sole body. As a result, the second opposing surface 31 (see FIG. 14) provided on the fixing wall portion 30 is configured as a surface inclined with respect to the thickness direction of the sole body, and accordingly, the first opposing surface 111a (see FIG. 14), which is the wall surface on the side of the cutout portion of the midsole 111, is also configured as a surface inclined with respect to the thickness direction of the sole body.

[0112] Here, all conditions except for the above-mentioned points were set to be the same for the simulation model 110Y of the shoe sole according to Comparative Example 2 and the simulation model 110A of Example 4. The direction of the external force applied to the simulation models 110Y and 110A of the shoe soles according to Comparative Example 2 and Example 4 was set to the vertical direction (i.e., the Z-axis direction).

[0113] As shown in Figure 16, when comparing the simulation model 110Y of the sole of Comparative Example 2 with the simulation model 110A of the sole of Example 4, it can be seen that the rigidity at the boundary between the midsole 111 and the cushioning materials 1Y, 1E is lower in the simulation model 110A of the sole of Example 4 than in the simulation model 110Y of the sole of Comparative Example 2.

[0114] Therefore, based on the results of the second verification test, it can be said that it has been experimentally confirmed that the sole 110 of this embodiment and the shoe 100 equipped with it can achieve both comfort and cushioning performance.

[0115] (First Modification) Fig. 17 is a perspective view of a cushioning material provided in a shoe sole according to the first modified example. Hereinafter, cushioning material 1D1' provided in a shoe sole according to the first modified example based on the above-mentioned embodiment 2 will be described with reference to Fig. 17. Note that this cushioning material 1D1' is provided in sole 110 according to the above-mentioned embodiment 2, instead of cushioning material 1D1 provided in sole 110.

[0116] As shown in Figure 17, the cushioning material 1D1' provided in the sole of this modified example differs from the cushioning material 1D1 provided in the sole 110 of the above-mentioned embodiment 2 only in that it does not have reinforcing portions 40, 40', 40''. In other words, the cushioning material 1D1' only has a cushioning portion 10 composed of multiple three-dimensional structural portions 12, an upper support portion 21 and a lower support portion 22 as support portions 20, and a fixing wall portion 30.

[0117] Even with this configuration, the same effects as those of the first embodiment described above can be obtained, and the boundary between the midsole 111 and the cushioning material 1D1' can be effectively prevented from becoming more rigid than the surrounding area, thereby resulting in a sole that is comfortable to wear and a shoe equipped with the sole.

[0118] (Second Modification) FIG. 18 is a perspective view of a cushioning material provided in a sole according to the second modified example. Hereinafter, with reference to FIG. 18, a cushioning material 1D1" provided in a sole according to the second modified example based on the above-described embodiment 2 will be described. Note that the cushioning material 1D1" is provided in the sole 110 according to the above-described embodiment 2, instead of the cushioning material 1D1 provided in the sole 110.

[0119] As shown in Figure 18, the cushioning material 1D1" provided in the sole of this modified example differs from the cushioning material 1D1' provided in the sole of the first modified example described above only in that it is provided with an extension portion 50. Specifically, the extension portion 50 has a plate-like shape and extends from the connection portion between the lower support portion 22 and the fixing wall portion 30 along the extension direction of the lower support portion 22 so as to exceed the fixing wall portion 30.

[0120] The extension portion 50 is a portion for increasing the bonding area of ​​the cushioning material 1D1" to the midsole 111 and the outsole 112, and by providing this extension portion 50, the cushioning material 1D1" is more firmly bonded to the midsole 111 and the outsole 112.

[0121] Therefore, with this configuration, effects similar to those of the first embodiment described above can be obtained, and it is possible to effectively prevent the boundary between the midsole 111 and the cushioning material 1D1" from becoming more rigid than the surrounding area, thereby making it possible to provide not only a sole and a shoe having such a sole that are excellent in comfort, but also a sole and a shoe having such a sole that are excellent in durability.

[0122] (Summary of the contents disclosed in the embodiments, etc.) The characteristic configurations disclosed in the above-described first and second embodiments and examples 1 to 4 and their modifications can be summarized as follows.

[0123] A cushioning material according to one embodiment of the present disclosure includes a cushioning section having a three-dimensional shape formed by a wall whose outer shape is defined by a pair of parallel curved surfaces. The cushioning section includes at least one three-dimensional structural section obtained by deforming a unit structure, which is based on a unit structure of a Schwarz P structure and has been thickened, into a trapezoidal space. The shape of the three-dimensional structural section in an unloaded state is obtained by deforming the unit structure so as to follow the shape change of the unit space, which is a regular hexahedral space occupied by the unit structure, into a trapezoidal space.

[0124] In a cushioning material according to a certain aspect of the present disclosure, when the axial direction is the direction in which the cushioning section is intended to exert its cushioning function when subjected to a load, the shape of the three-dimensional structural section in an unloaded state may be a shape obtained by changing the shape of the unit space, which is a regular hexahedral space, into a trapezoidal space by tilting each of the faces included in one of two pairs of opposing faces, excluding the pair of opposing faces located in the axial direction, out of its three pairs of opposing faces, and then changing the shape of the unit structure to follow this.

[0125] In a cushioning material according to a certain aspect of the present disclosure, when the axial direction is the direction in which the cushioning section is intended to perform its cushioning function when subjected to a load, the shape of the three-dimensional structural section in an unloaded state may be a shape obtained by changing the shape of the unit space, which is a regular hexahedral space, into a trapezoidal space by tilting each of the faces included in both of two pairs of opposing faces, excluding one pair of opposing faces located in the axial direction, out of three pairs of opposing faces, and then changing the shape of the unit structure to follow this.

[0126] In a cushioning material according to a certain aspect of the present disclosure, a flat support portion perpendicular to the axial direction may be provided on at least one of a pair of ends located in the axial direction of the three-dimensional structure portion.

[0127] In a cushioning material according to a certain aspect of the present disclosure, when viewed along the axial direction, the support portion may have a protruding region that protrudes outward beyond the end of the three-dimensional structure portion on the support portion side, and in that case, a reinforcing portion for suppressing deformation of the support portion in the protruding region may be provided to connect the portion of the three-dimensional structure portion near the end of the support portion side and the support portion at the portion corresponding to the protruding region.

[0128] In a cushioning material according to a certain aspect of the present disclosure, the cushioning portion may include a plurality of the three-dimensional structural portions, and in this case, the plurality of three-dimensional structural portions may be arranged in a row so that the axial directions of each of the three-dimensional structural portions are approximately parallel to each other.

[0129] In a cushioning material according to a certain aspect of the present disclosure, the cushioning portion may include a plurality of the three-dimensional structural portions, and in this case, the plurality of three-dimensional structural portions may be arranged in a matrix such that the axial directions of each of the three-dimensional structural portions are approximately parallel to one another.

[0130] A shoe sole according to an embodiment of the present disclosure comprises the above-described cushioning material according to an embodiment of the present disclosure.

[0131] In a sole according to one aspect of the present disclosure, the cushioning material may be arranged so that the axial direction in which the cushioning portion exerts its cushioning function when subjected to load is perpendicular to the ground surface.

[0132] A shoe according to an aspect of the present disclosure comprises a sole according to an aspect of the present disclosure described above, and an upper provided above the sole.

[0133] (Other forms, etc.) In the above-described second embodiment and its modified examples, the case where the cushioning material is arranged along a portion of the periphery of the sole has been described as an example. However, the location of the cushioning material is not limited to this and can be changed as appropriate. For example, the cushioning material may be arranged along the entire periphery of the sole, or may be arranged inward from the periphery of the sole. Furthermore, the cushioning material may be arranged over the entire sole. Furthermore, depending on the type of sport and purpose for which the shoe is used, the cushioning material may be arranged only on the medial or lateral side of the sole. Furthermore, the cushioning material may be arranged between the midsole and the upper, or the cushioning material itself may be configured to double as the outsole. Here, when the cushioning material is arranged over the entire surface of the sole, the entire sole may be replaced with the cushioning material instead of the midsole.

[0134] Furthermore, in the above-mentioned second embodiment and its variant examples, the present invention has been described as being applied to a shoe having a tongue and shoelaces, but the present invention may also be applied to shoes that do not have these (for example, shoes having a sock-like upper) and the soles provided therefor.

[0135] Furthermore, in the above-mentioned second embodiment and its modified examples, the cushioning material according to the present invention has been described as being applied to the soles of shoes, but the cushioning material according to the present invention can be used for other cushioning purposes. For example, the cushioning material according to the present invention can be used for a variety of purposes, such as packaging material, flooring material for buildings (such as houses), surface materials for paved roads, surface materials for sofas and chairs, tires, etc.

[0136] Furthermore, the characteristic configurations disclosed in the above-described first and second embodiments and examples 1 to 4, as well as their modifications, can be combined with one another within the scope of the present invention.

[0137] As such, the above-described embodiments disclosed herein are illustrative in all respects and are not limiting. The technical scope of the present invention is defined by the claims, and includes all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0138] 1, 1A to 1E, 1D1 to 1D3, 1D1', 1D1" cushioning material, 10 cushioning portion, 11 wall, 12, 12A, 12B, 12M three-dimensional structure portion, 13 opening, 20 support portion, 21 upper support portion, 21a through hole, 22 lower support portion, 22a through hole, 30 fixing wall portion, 31 second opposing surface, 32, 32 (13) through hole, 40, 40', 40" reinforcement portion, 50 extension portion, 100 shoe, 110 sole, 110A, 110Y shoe sole simulation model, 111 midsole, 111a first opposing surface, 112 outsole, 112a ground contact surface, 113 adhesive layer, 120 upper, 121 upper body, 122 shoe tongue, 123 Shoelace, A1, A2, B1, B2, C1, C2 opposing surfaces, R1 forefoot, R2 midfoot, R3 rearfoot, S unit space.

Claims

1. A cushioning material for shoe soles, comprising a cushioning part having a three-dimensional shape formed by a wall whose outer shape is defined by a pair of parallel curved surfaces, the buffer portion includes at least one three-dimensional structure portion obtained by changing the shape of a unit structure obtained by adding a thickness to a unit structure of a Schwarz P structure, When the axial direction is the direction in which the buffer section is intended to exert its buffering function when subjected to a load, the shape of the three-dimensional structural section in an unloaded state is a shape obtained by changing the shape of the unit structure so that it follows the shape change of the unit space, which is a regular hexahedral space occupied by the unit structure, when each of the faces included in one of two sets of opposing faces, excluding the one set of opposing faces located in the axial direction, is inclined.

2. A cushioning material for shoe soles, comprising a cushioning part having a three-dimensional shape formed by a wall whose outer shape is defined by a pair of parallel curved surfaces, the buffer portion includes at least one three-dimensional structure portion obtained by changing the shape of a unit structure obtained by adding a thickness to a unit structure of a Schwarz P structure, When the axial direction is the direction in which the buffer section is intended to exert its buffering function when subjected to a load, the shape of the three-dimensional structural section in an unloaded state is such that, when a unit space, which is a regular hexahedral space occupied by the unit structure, is deformed so that each of the faces included in both of two sets of opposing faces, excluding one set of opposing faces located in the axial direction, out of three sets of opposing faces, is inclined, and the shape of the unit structure is deformed to follow this.

3. 3. The cushioning material for shoe soles according to claim 1, wherein a flat support portion perpendicular to the axial direction is provided on at least one of a pair of ends of the three-dimensional structure located in the axial direction.

4. When viewed along the axial direction, the support portion has a protruding region that protrudes outward from an end portion of the three-dimensional structure portion on the support portion side, 4. The cushioning material for shoe soles according to claim 3, wherein a reinforcing portion for suppressing deformation of the support portion in the protruding region is provided so as to connect the portion of the three-dimensional structure near the end of the support portion and the support portion in the portion corresponding to the protruding region.

5. the buffer portion includes a plurality of the three-dimensional structures, 5. The cushioning material for shoe soles according to claim 1, wherein the plurality of three-dimensional structures are arranged in a row so that the axial directions of the respective three-dimensional structures are positioned approximately parallel to each other.

6. the buffer portion includes a plurality of the three-dimensional structures, 5. The cushioning material for shoe soles according to claim 1, wherein the plurality of three-dimensional structures are arranged in a matrix such that the axial directions of the respective three-dimensional structures are positioned approximately parallel to one another.

7. A shoe sole comprising the shock-absorbing material for shoe soles according to any one of claims 1 to 6.

8. The shoe sole according to claim 7, wherein the shock-absorbing material for a shoe sole is arranged so that the axial direction in which the shock-absorbing portion exerts a shock-absorbing function by receiving a load is perpendicular to the ground surface.

9. The shoe sole according to claim 7 or 8, and an upper provided above the sole.

Images