Shoe components

Abstract

To provide shoe components with improved cushioning properties. [Solution] A shoe component is provided, comprising a three-dimensional lattice structure having a plurality of support columns and a plurality of connecting parts connecting the support columns, wherein the three-dimensional lattice structure is made of a resin composition, and the three-dimensional lattice structure is provided with one or both of the following high-density parts: a cylindrical high-density part extending in the longitudinal direction of the support columns having a density higher than the average density of each of the plurality of support columns, and a shell-shaped high-density part along the surface of the connecting part having a density higher than the average density of each of the plurality of connecting parts.

Description

Technical Field

[0005]

[0001] This disclosure relates to a shoe member.

Background Art

[0002] Conventionally, the use of a three-dimensional structure composed of plate-like partition bodies as a buffer has been considered (see Patent Document 1 below). Regarding such a three-dimensional structure, the use of a three-dimensional lattice structure including cell elements including a plurality of struts as a shoe member has been considered (see Patent Document 2 below).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a three-dimensional structure adopted for a shoe member, when compressed, the partition bodies and struts constituting the three-dimensional structure may collide with each other, generating an excessively high repulsive force. Therefore, when adopting this type of three-dimensional structure, it is difficult to exhibit good buffering performance in shoes. The present invention aims to provide a shoe member with improved buffering performance.

Means for Solving the Problems

[0005] A shoe member according to one aspect of the present disclosure is composed of a three-dimensional lattice structure including a plurality of struts and a plurality of connection parts connecting the struts to each other, where the three-dimensional lattice structure is composed of a resin composition, and the three-dimensional lattice structure has A cylindrical high-density section extending in the longitudinal direction of the support column, having a density higher than the average density of each of the aforementioned plurality of support columns, The shoe component is provided with one or both of the high-density portions, which are shell-shaped high-density portions along the surface layer of the connection portions and have a density higher than the average density of each of the multiple connection portions. [Effects of the Invention]

[0006] According to the present invention, a shoe component with improved cushioning properties can be provided. [Brief explanation of the drawing]

[0007] [Figure 1A] Figure 1A is a schematic perspective view of a shoe equipped with a shoe component according to one embodiment. [Figure 1B] Figure 1B is a schematic perspective view showing a part of a three-dimensional lattice structure in one embodiment. [Figure 2A] Figure 2A is a schematic perspective view showing an example of a lattice used to construct a three-dimensional grid structure. [Figure 2B] Figure 2B is a schematic perspective view showing the unit structure of one embodiment of a three-dimensional lattice structure. [Figure 2C] Figure 2C is a schematic perspective view showing the shape of a unit structure of one embodiment of a three-dimensional lattice structure. [Figure 3] Figure 3 is a schematic perspective view showing another aspect of the unit structure of a three-dimensional lattice structure. [Figure 4] Figure 4 is a schematic cross-sectional view (viewed along the line IV-IV in Figure 2B) showing a cross-section of the support column of one embodiment of a three-dimensional lattice structure. [Figure 5] Figure 5 is a schematic cross-sectional view (viewed along the VV line in Figure 2B) showing a cross-section of the connection part of one embodiment of a three-dimensional lattice structure. [Figure 6A] Figure 6A is a schematic perspective view showing the positional relationship of support columns at the connection point of one embodiment of a three-dimensional lattice structure. [Figure 6B] Figure 6B is a schematic plan view showing the positional relationship of the support columns at the connection point of one embodiment of a three-dimensional lattice structure. [Figure 7]FIG. 7 is a schematic cross-sectional view of a column having a cavity inside. [Figure 8A] FIG. 8A is a schematic plan view showing a state where ribs are provided on the column and the connecting portion. [Figure 8B] FIG. 8B is a schematic cross-sectional view of the column provided with ribs (a cross-sectional view taken along the arrow B-B in FIG. 8A). [Figure 9] FIG. 9 is a schematic perspective view of the column provided with ribs. [Figure 10] FIG. 10 is a schematic cross-sectional view of a column having ribs inside. [Figure 11A] FIG. 11A is a schematic cross-sectional view showing a state where ribs are provided on a column whose interior is a foam. [Figure 11B] FIG. 11B is a schematic cross-sectional view showing a state where ribs are provided on a column whose interior is a foam. [Figure 12] FIG. 12 is a schematic cross-sectional view of a column having an elliptical cross-sectional shape. [Figure 13] FIG. 13 is a schematic cross-sectional view of a column in which the thickness of the high-density portion varies in the circumferential direction. [Figure 14] FIG. 14 is a schematic cross-sectional view of a column provided with three ribs such that the protruding directions are radial. [Figure 15] FIG. 15 is a view showing a model of a three-dimensional lattice structure used for evaluation in the embodiment. [Figure 16] FIG. 16 is a view showing the evaluation results using the model of FIG. 15. [Figure 17] FIG. 17 is a view showing the relationship between the degree of foaming inside the three-dimensional lattice structure and the repulsive behavior to a load.

MODE FOR CARRYING OUT THE INVENTION

[0008] The following describes one embodiment of a shoe component with reference to the figure. First, the shoe component of one embodiment will be described with reference to shoe 1, which is illustrated in Figure 1A. In the following description, the vertical direction may be referred to as the "height direction DZ," etc. Also, in the following description, among the directions along the horizontal plane, the direction connecting the heel and toe of shoe 1 may be referred to as the "foot length direction DX," etc. And, in the following description, among the directions along the horizontal plane, the direction perpendicular to the foot length direction DX may be referred to as the "foot width direction DY," etc.

[0009] In this disclosure, shoe 1 is a sports shoe. Shoe 1 comprises a sole 2 that supports the wearer's foot from below and an upper 3 that covers the wearer's foot from the top. The sole 2 and upper 3 illustrated in the figure are each composed of a three-dimensional lattice structure 10. In this disclosure, shoe 1 may have a shoe body comprising the sole 2 and the upper 3, and an insole that is detachably provided on the shoe body. In this disclosure, the shoe component composed of the three-dimensional lattice structure 10 may be the insole.

[0010] The three-dimensional lattice structure 10 that constitutes the shoe sole 2 illustrated in Figure 1A comprises a plurality of support columns 11 and a plurality of connecting parts 12 that connect the support columns 11 to each other, as shown in Figure 1B. The three-dimensional lattice structure 10 in this disclosure is made of a resin composition. The three-dimensional lattice structure 10 is configured such that parallel polyhedra and the like are repeatedly arranged by arranging lattice grids in a three-dimensional direction as shown in Figure 2A. The lattice grids may be simple cubic grids, body-centered cubic configurations, face-centered cubic grids, diamond grids, octahedral grids, and the like.

[0011] The three-dimensional lattice structure 10 is composed of repeated unit structures C, each consisting of multiple support columns 11 and multiple connecting parts 12. In one embodiment, the unit structure C has the shape of a rhombic dodecahedron Cx, as shown in Figures 2B and 2C.

[0012] The three-dimensional lattice structure 10 includes a row of unit structures C arranged linearly so as to extend in the foot length direction DX. The three-dimensional lattice structure 10 includes multiple rows of unit structures extending in the foot length direction DX. The multiple rows of unit structures are closely aligned with each other in the foot width direction DY. The multiple rows of unit structures constitute a unit structure layer in the three-dimensional lattice structure 10 with a dimension in the height direction DH equal to that of one unit structure C. The three-dimensional lattice structure 10 includes multiple unit structure layers. In the three-dimensional lattice structure 10, the multiple unit structure layers are stacked in the height direction DZ. The sole 2, which is a three-dimensional lattice structure 10 composed of repeating unit structures C in this way, can easily disperse the load when a load is applied by the user's foot.

[0013] The three-dimensional lattice structure 10 makes it easier to design shoe components of various shapes by incorporating, as an overall structure or substructure, a one-dimensional structure (column) in which a normalized unit structure is repeated in at least one direction, a two-dimensional structure (layer) in which it is repeated in both a second direction intersecting the first direction and the first direction, and a three-dimensional structure (laminated) in which it is also repeated in a third direction intersecting a virtual plane including the first and second directions.

[0014] In space-filling with rhombic dodecahedrons Cx, one vertex CN is shared by six rhombic dodecahedrons Cx, and one edge SD is shared by three rhombic dodecahedrons Cx. Therefore, in the three-dimensional lattice structure 10 of this disclosure, one connection part 12 is shared by six unit structures C, and one support 11 is shared by three unit structures C. A rhombic dodecahedron Cx has 24 edges SD and 14 vertices CN. Therefore, considering only one unit structure C, the three-dimensional lattice structure 10 is composed of repeating unit structures C, each consisting of 24 support 11s and 14 connection parts 12.

[0015] In this disclosure, the unit structure C is a rhombic dodecahedron Cx, which is a parallelepiped, and therefore can fill the space without gaps using only the unit structure C. The shape of the unit structure C may be a parallelepiped, a parallelepiped prism, a long rhombic dodecahedron, or a truncated octahedron. The three-dimensional lattice structure 10 may consist of two types of unit structures arranged alternately in one direction. The three-dimensional lattice structure 10 may consist of three types of unit structures, each arranged repeatedly in one direction with other unit structures in between.

[0016] If the three-dimensional lattice structure 10 includes repetitions of two types of unit structures, the shape of each unit structure can be, for example, a regular tetrahedron and a regular octahedron. The two types of unit structures may be, for example, a regular tetrahedron and a truncated tetrahedron. The two types of unit structures may be, for example, a regular octahedron and a truncated hexahedron. The two types of unit structures may be, for example, a regular octahedron and a cuboctahedron. The two types of unit structures may be, for example, a rhombic truncated cuboctahedron and a regular octagonal prism.

[0017] If the three-dimensional lattice structure 10 includes repetitions of three types of unit structures, the shape of each unit structure can be, for example, a truncated tetrahedron, a truncated octahedron, and a cuboctahedron. The three types of unit structures may also be, for example, a truncated tetrahedron, a truncated hexahedron, and a rhombic truncated cuboctahedron. The three types of unit structures may also be, for example, a regular tetrahedron, a cube, and a rhombic cuboctahedron. The three types of unit structures may also be, for example, a cube, a cuboctahedron, and a rhombic cuboctahedron. The three types of unit structures may also be, for example, a cube, a truncated octahedron, and a rhombic truncated cuboctahedron. The three-dimensional lattice structure 10 may also have four shapes, for example, a cube, a truncated hexahedron, a rhombic truncated cuboctahedron, and a regular octagonal prism.

[0018] In the three-dimensional lattice structure 10 shown in Figure 2A and other figures, the connecting portion 12 is a node corresponding to a vertex CN of the rhombic dodecahedron Cx. In this disclosure, the connecting portion 12 of the three-dimensional lattice structure 10 may be plate-like, for example, as shown in Figure 3, corresponding to some faces PL of the rhombic dodecahedron Cx.

[0019] In the three-dimensional lattice structure 10 of this disclosure, at least one of the multiple support columns 11 and the multiple connecting parts 12 has a different density in its surface and interior. The multiple support columns 11 in this disclosure have high-density sections with a density higher than their average density. The average density of the support columns 11 is calculated by separating the support columns 11 from the three-dimensional lattice structure 10, measuring their mass with an electronic balance, and measuring their apparent volume with a three-dimensional measuring machine. The average density of the connecting parts 12 is measured in the same manner. Average density = mass / apparent volume

[0020] As shown in Figure 4, in one embodiment, the support column 11 has a circular cross-sectional shape in a plane perpendicular to the longitudinal direction DL of the support column 11. The support column 11 is cylindrical. The cross-sectional shape of the support column 11 may be a polygon such as a triangle or a quadrilateral. The support column 11 may also be a prismatic shape. The cross-sectional shape of the support column 11 may be irregular.

[0021] In one embodiment, the column 11 has different densities at the center and on the outside in the radial direction Dd. In one embodiment, the interior of the column 11 is made of resin foam. As shown in the figure, the high-density portion 11A is arranged to constitute the surface layer of the column 11. The high-density portion 11A that constitutes the surface layer of the column 11 may be made of resin foam with a lower degree of foaming than the interior. In one embodiment, the high-density portion 11A is a non-foamed material made of a non-foamed resin composition. The high-density portion 11A of the column 11 illustrated in the figure is cylindrical and extends in the longitudinal direction DL of the column. The thickness of the high-density portion 11A in the radial direction Dd is uniform in the circumferential direction Dr. The column 11 has a low-density portion 11B made of resin foam. The low-density portion 11B has a lower density than the high-density portion 11A and a lower density than the average density of the column 11. The low-density portion 11B is provided so as to be in contact with the inner circumferential surface of the cylindrical high-density portion 11A from the inside.

[0022] In one embodiment of the three-dimensional lattice structure 10, as shown in Figure 5, the high-density portion 12A is arranged in the connection portion 12 to constitute the surface layer. The high-density portion 12A in the connection portion 12 is shell-shaped. Similar to the support column 11, the connection portion 12 also has a low-density portion 12B made of resin foam on the central side of the high-density portion 12A. In the embodiment illustrated in Figure 5, the connection portion 12 has a core-shell structure, with the core portion being a low-density portion 12B made of resin foam and the shell portion being a high-density portion 12A made of non-foamed material.

[0023] In the three-dimensional lattice structure 10, the non-foam material constituting the surface layer of one support column 11 is continuous along the length DL of the support column 11 and continues to the non-foam material of other support columns 11 via the non-foam material of the connecting portion 12. That is, in one embodiment of the three-dimensional lattice structure 10, a plurality of support columns 11 are connected to a single connecting portion 12, and the plurality of support columns 11 include a first support column 11 and a second support column 11, and the high-density portion 11A of the first support column 11 and the high-density portion 11A of the second support column 11 are continuous via the high-density portion 12A of the connecting portion 12. In one embodiment of the three-dimensional lattice structure 10, the high-density portions 11A of the plurality of support columns 11 and the high-density portions 12A of the plurality of connecting portions 12 may be connected throughout the entire three-dimensional lattice structure 10.

[0024] In the three-dimensional lattice structure 10, the resin foam constituting the central part of one support column 11 is continuous along the length DL of the support column 11 and continues to the resin foam of other support columns 11 via the resin foam of the connecting portion 12. That is, in one embodiment of the three-dimensional lattice structure 10, a plurality of support columns 11, including a first support column 11 and a second support column 11, are connected to a single connecting portion 12, and the low-density portion 11B of the first support column 11 and the low-density portion 11B of the second support column 11 may be continuous via the low-density portion 12B of the connecting portion 12. In the three-dimensional lattice structure 10, the low-density portions 11B of the plurality of support columns 11 and the low-density portions 12B of the plurality of connecting portions 12 may be connected throughout the entire three-dimensional lattice structure 10.

[0025] One or both of the resin foam constituting the central part of the support column 11 and the resin foam constituting the central part of the connecting part 12 may be open-cell foam having open cells. In one embodiment, the open-cell ratio of the open-cell foam is 50% or more. The open-cell ratio may be 60% or more, 70% or more, or 80% or more. The open-cell ratio is determined on a cell-based basis. The open-cell ratio is calculated, for example, by cutting the support column 11 or the connecting part 12 and counting the number of cells in the resin foam observed in the cross-section that are in communication with adjacent cells. The cross-section is observed with a scanning electron microscope (SEM). The cross-section is photographed at a magnification of 200x. The open-cell ratio is calculated by observing several cells (e.g., 100) randomly selected from the obtained micrographs and counting the number of cells that are in communication with adjacent cells.

[0026] The support columns 11 and connecting parts 12 are made of open-cell foam resin, allowing air to move within them through interconnected air bubbles. The three-dimensional lattice structure 10 may also be made of open-cell foam resin in both the support columns 11 and connecting parts 12, allowing air to move throughout the entire structure. The support columns 11 and connecting parts 12 may have ventilation holes that connect the external space to the open-cell foam. These ventilation holes may be provided in only one location or in multiple locations on the three-dimensional lattice structure 10. A three-dimensional lattice structure 10 with ventilation holes can expel air contained in the resin foam to the outside when compressed, resulting in a slower onset of repulsive force against compressive force.

[0027] For purposes such as enabling the three-dimensional lattice structure 10 to exhibit high repulsive force, one or both of the resin foam constituting the central part of the support column 11 and the resin foam constituting the central part of the connecting part 12 may be made of closed-cell foam. The closed-cell ratio (100% - open-cell ratio) of the closed-cell foam is, for example, 50% or more. The closed-cell ratio of the closed-cell foam may be 60% or more, 70% or more, or 80% or more.

[0028] The three-dimensional lattice structure 10 that constitutes the sole 2 has upward-facing support columns 111 that extend upward from the connection portion 12 and downward-facing support columns 112 that extend downward from the connection portion 12 when the structure is arranged so that its thickness direction is the height direction DZ. In the three-dimensional lattice structure 10, a plurality of upward-facing support columns 111 are connected to the connection portion 12.

[0029] Multiple upward-facing support columns 111 extend from the connection portion 12 such that the distance between them increases as they extend upward. As shown in Figure 6A, multiple upward-facing support columns 111 extend from the connection portion 12 such that they have the same elevation angle θ1 with respect to one of the virtual planes passing through the connection portion 12. In one embodiment, multiple upward-facing support columns 111 extend from the connection portion 12 such that they have the same elevation angle θ1 with respect to a virtual plane P1 that intersects the height direction DZ and extends in the leg length direction DX and the leg width direction DY.

[0030] The elevation angle θ1 of the upward support column 111 may be, for example, 10 degrees or more. The elevation angle θ1 may be 15 degrees or more, 20 degrees or more, or 25 degrees or more. The elevation angle θ1 of the upward support column 111 may be, for example, 70 degrees or less. The elevation angle θ1 may be 60 degrees or less, or 50 degrees or less.

[0031] The connection point 12 to which multiple upward-facing support columns 111 are connected so that they share a common elevation angle θ1 may be only a part of the connection point 12 to which multiple upward-facing support columns 111 are connected. When the total number of connection points 12 to which multiple upward-facing support columns 111 are connected is taken as 100%, the number of connection points 12 to which they share a common elevation angle θ1 may be 10% or more, 20% or more, 30% or more, 40% or more, or 50% or more.

[0032] In the three-dimensional lattice structure 10, multiple downward-facing columns 112 are connected to a connection point 12 to which multiple upward-facing columns 111 are connected. The multiple downward-facing columns 112 extend from the connection point 12 such that the distance between them increases as they extend downward. The multiple downward-facing columns 112 extend from the connection point such that they have the same depression angle θ2 with respect to the virtual plane P1.

[0033] The downward angle θ2 of the downward support column 112 may be, for example, 10 degrees or more. The downward angle θ2 may be 15 degrees or more, 20 degrees or more, or 25 degrees or more. The downward angle θ2 of the downward support column 112 may be, for example, 70 degrees or less. The downward angle θ2 may be 60 degrees or less, or 50 degrees or less.

[0034] The connection point 12 to which multiple downward-facing support columns 112 are connected so that they share a common depression angle θ2 may be only a part of the connection point 12 to which multiple downward-facing support columns 112 are connected. When the total number of connection points 12 to which multiple downward-facing support columns 112 are connected is considered to be 100%, the number of connection points 12 to which they share a common depression angle θ2 may be 10% or more, 20% or more, 30% or more, 40% or more, or 50% or more.

[0035] The connection point 12 to which multiple upward-facing support columns 111 with a common elevation angle θ1 and multiple downward-facing support columns 112 with a common depression angle θ2 are connected may be a part of all the connection points 12 to which the multiple upward-facing support columns 111 and the multiple downward-facing support columns 112 are connected. The connection point 12 to which both elevation angle θ1 and depression angle θ2 are common may be 10% or more, 20% or more, 30% or more, 40% or more, or 50% or more of all the connection points 12 to which the multiple upward-facing support columns 111 and the multiple downward-facing support columns 112 are connected.

[0036] The elevation angle θ1 of the upward support 111 and the depression angle θ2 of the downward support 112 may or may not coincide.

[0037] In one embodiment, the virtual plane P1 may be a horizontal plane. In that case, the normal direction of the virtual plane P1 is the height direction DZ of the shoe 1. The height direction DZ is the direction in which the user's weight is applied to the sole 2, and is the direction in which a large load is applied. As shown in Figure 6B, in one embodiment, the three-dimensional lattice structure 10 is configured such that, when viewed from the height direction DZ, which is the direction in which the load is applied, a plurality of support columns 11 extend radially from a single connection part 12. In the three-dimensional lattice structure 10 in one embodiment, a plurality of upward support columns 111 and a plurality of downward support columns 112 connected to a single connection part 12 each extend radially from the said connection part 12.

[0038] Each of the multiple downward-facing support columns 112 is positioned between adjacent upward-facing support columns 111 in the circumferential direction DC, where DC is defined as the direction along the circle centered on the connecting portion 12 to which the upper end of the downward-facing support column 112 is connected.

[0039] Each of the multiple upward-facing support columns 111 and the multiple downward-facing support columns 112 is arranged at equal intervals in the circumferential direction DC. When the number of upward-facing support columns 111 connected to one connection part 12 is n (n≧2), adjacent upward-facing support columns 111 in the circumferential direction DC are arranged at an opening angle of (360 / n) degrees. In the configuration shown in Figure 6B, two upward-facing support columns 111 and two downward-facing support columns 112 are connected to one connection part 12. In the configuration shown in Figure 6B, the two upward-facing support columns 111 are connected to the connection part 12 at an opening angle of 180 degrees (360 degrees / 2). Also, in the configuration shown in Figure 6B, the two downward-facing support columns 112 are connected to the connection part 12 at an opening angle of 180 degrees (360 degrees / 2).

[0040] In the embodiment shown in Figure 6B, each of the multiple downward-facing support columns 112 is located midway between two adjacent upward-facing support columns 111 in the circumferential direction DC. Therefore, adjacent downward-facing support columns 112 and upward-facing support columns 111 in the circumferential direction DC are connected to a single connection 12 at a 90-degree angle. Thus, in one embodiment of the three-dimensional lattice structure 10, the multiple support columns 11 extending from a single connection 12 are arranged to exhibit rotational symmetry with respect to the circumferential direction DC. That is, in one embodiment of the three-dimensional lattice structure 10, the number of multiple upward-facing support columns 111 extending from a single connection 12 is the same as the number of multiple downward-facing support columns 112 (n columns: n≧2), and these support columns 11 are connected to the connection 12 to exhibit rotational symmetry that is n times symmetric in the circumferential direction DC. This ensures that the load applied to the three-dimensional lattice structure 10 is uniformly distributed.

[0041] In one embodiment, the cross-sectional shape of the upward support column 111 and the downward support column 112 in a plane perpendicular to the longitudinal direction DL is common at one point in the longitudinal direction DL and at another point different from that point.

[0042] In other embodiments, the cross-sectional shape of the upward support 111 and the downward support 112 in a plane perpendicular to the length direction DL may differ at one point along the length direction DL and at another point different from that point. The upward support 111 and the downward support 112 may each have a shape in which the diameter changes along the length direction DL. The upward support 111 and the downward support 112 may each have a shape in which the diameter increases as it moves away from the connection part 12. The upward support 111 and the downward support 112 may each have a shape in which the diameter decreases as it moves away from the connection part 12. The upward support 111 and the downward support 112 may each have a shape in which the middle part along the length direction DL is thicker and both ends are thinner than the middle part. The upward support 111 and the downward support 112 may each have a shape in which both ends along the length direction DL are thicker than the middle part.

[0043] By changing the cross-sectional shape of the upward support 111 and downward support 112 in the longitudinal direction DL, it becomes easier to control the state of rigidity and reduce the weight of the three-dimensional lattice structure 10.

[0044] In one embodiment, the support column 11 comprises a high-density section 11A and a low-density section 11B made of foam, with the high-density section 11A forming a cylindrical shape that covers the low-density section 11B. This high-density section 11A provides the support column 11 with excellent rigidity. In another embodiment, the connecting section 12 comprises a high-density section 12A and a low-density section 12B made of foam, with the high-density section 12A forming a shell shape that covers the low-density section 12B. Having this high-density section 12A provides the connecting section 12 with excellent rigidity. Because the support column 11 and the connecting section 12 have high-density sections 11A and 12A, the three-dimensional lattice structure 10 exhibits excellent repulsive force against applied loads.

[0045] When the shoe 1 is used, a compressive load is applied to the three-dimensional lattice structure 10 that makes up the sole 2 from the height direction DZ. The support columns and connecting parts exhibit high rigidity even when they are made of a non-foamed resin composition throughout. However, when a three-dimensional lattice structure is made with such support columns and connecting parts, the repulsive force against the applied load increases sharply when the structure is compressed to the point where the support columns are in contact with each other, the connecting parts are in contact with each other, or the support columns and connecting parts are in contact.

[0046] When the three-dimensional lattice structure 10 is compressed to a state where the support columns 11 are in contact with each other, the connecting parts 12 are in contact with each other, or the support columns 11 and the connecting parts 12 are in contact, the support columns 11 and connecting parts 12 in the three-dimensional lattice structure 10 of this disclosure are more susceptible to further compression deformation because the interior is made of foam. Therefore, by adopting the three-dimensional lattice structure 10 of this disclosure, a shoe component with improved cushioning can be provided. Furthermore, in the three-dimensional lattice structure 10 in the embodiment shown in Figure 6B, the multiple support columns 11 extending from one connecting part 12 are arranged so as not to overlap when viewed from the direction in which the load is applied (height direction DZ in Figure 6B). Therefore, cushioning is further improved in this embodiment.

[0047] In the three-dimensional lattice structure 10 as shown in Figure 6B, the multiple support columns 11 extending from a single connection point 12 are arranged so that they do not overlap vertically when viewed from the direction in which the load is applied (height direction DZ in Figure 6B). Therefore, the cushioning performance is further improved in this configuration.

[0048] The connection portion 12 that connects the upward support 111 and the downward support 112 so that they do not overlap vertically when viewed from the height direction DZ may be a part of the connection portion 12 that connects the upward support 111 and the downward support 112. When the total number of connection portions 12 that connect the upward support 111 and the downward support 112 is taken as 100%, the connection portion 12 that connects the upward support 111 and the downward support 112 so that they do not overlap may be 10% or more, 20% or more, 30% or more, 40% or more, or 50% or more.

[0049] To improve cushioning, the low-density sections 11B and 12B may be simple cavities, as shown in Figure 7. The three-dimensional lattice structure 10 may employ columns 11 and connecting sections 12 that are hollow on the central side of the high-density sections 11A and 12A, instead of the columns 11 and connecting sections 12 that have a resin foam interior as exemplified so far. In this embodiment, the column 11 may be a hollow body (tube) having a cavity in the inner part of the column 11 in the radial direction Dd that is continuous in the longitudinal direction DL of the column 11. In this embodiment, the connecting section 12 may be a hollow body having a cavity on the central side of the high-density section 12A.

[0050] In the three-dimensional lattice structure 10, the cavity in the center of one support column 11 may be continuous along the length DL of the support column 11 and communicate with the cavities of other support columns 11 via the cavities of the connecting parts 12. That is, in one embodiment of the three-dimensional lattice structure 10, a plurality of support columns 11, including a first support column 11 and a second support column 11, are connected to a single connecting part 12, and the first support column 11, the second support column 11, and the connecting part 12 connecting them may be hollow bodies, and the cavities inside them may communicate with each other. In the three-dimensional lattice structure 10, the cavities inside the support columns 11 and the connecting parts 12 may communicate throughout the entire three-dimensional lattice structure 10.

[0051] In this case as well, the fact that the support column 11 has a cylindrical high-density section 11A and the connecting section 12 has a shell-shaped high-density section 12A results in excellent rigidity for each. Furthermore, the three-dimensional lattice structure 10 in this configuration also exhibits excellent repulsive force against applied loads. In order to make the three-dimensional lattice structure 10 exhibit excellent repulsive force, ribs 11r may be provided on the support column 11 as shown in Figure 8A. In addition to the ribs 11r on the support column 11, ribs 12r may be provided on the connecting section 12.

[0052] Even in a three-dimensional lattice structure 10 with a hollow interior, as shown in Figure 8B, providing ventilation holes 11h in the support columns 11 that connect the internal cavity of the support columns 11 with the external space makes the reaction force against compressive force more gradual.

[0053] The ribs 11r on the support column 11 may be provided linearly along the length DL of the support column 11, or they may be provided in a spiral pattern around the central axis of the support column 11. Only one rib 11r may be provided on a single support column 11, or multiple ribs 11r may be provided.

[0054] As shown in Figure 9, assuming a plane P2 passing through the center and the rib 11r, the column 11 exhibits superior rigidity when bent in the direction along the plane P2. On the other hand, when bent in a direction perpendicular to this direction, the column 11 bends relatively more easily than when bent along the plane P2. In other words, by providing the rib 11r, it is possible to introduce anisotropy into the bending rigidity of the column 11, and the bending direction of the column 11 can include a high-rigidity direction D1 in which excellent rigidity is exhibited and a low-rigidity direction D2 in which the exhibited rigidity is suppressed compared to the high-rigidity direction D1.

[0055] If the protruding direction (high-rigidity direction D1) of the ribs 11r of the multiple support columns 11 provided in the three-dimensional lattice structure 10 is randomized, the three-dimensional lattice structure 10 exhibits an improved rebound force effect regardless of the direction in which it is subjected to a load. If the protruding direction of the ribs 11r of the multiple support columns 11 provided in the three-dimensional lattice structure 10 is aligned to a specific direction, the three-dimensional lattice structure 10 also exhibits anisotropy in rigidity, such as rebound force against load. Therefore, by providing ribs 11r, the rigidity design of the three-dimensional lattice structure 10 becomes easier.

[0056] When the protruding directions of the ribs 11r are aligned to exhibit anisotropy in the rigidity of the three-dimensional lattice structure 10, only some of the support columns 11 may have ribs 11r protruding in a specific direction. When the total number of support columns 11 with ribs 11r is considered to be 100%, the number of support columns 11 with a common protruding direction of ribs 11r may be 10% or more, 20% or more, 30% or more, 40% or more, or 50% or more.

[0057] The protruding direction of the rib 11r is not limited to outward in the radial direction Dd, but may also be inward in the radial direction Dd, as shown in Figure 10. When multiple ribs 11r are provided on a single support column 11, both inward-facing ribs 11r and outward-facing ribs 11r may be provided. Furthermore, the rib 11r may be provided not only on a support column 11 with a hollow interior, but also when the low-density portion 11B is made of resin foam, as shown in Figures 11A and 11B. In such cases as well, the bending direction of the support column 11 can include both a high-rigidity direction D1 and a low-rigidity direction D2.

[0058] As a method for exhibiting anisotropy in bending stiffness, the cross-sectional shape of the support column 11 may be an oval or ellipse, as shown in Figure 12, with the major axis direction being the high-stiffness direction D1 and the minor axis direction being the low-stiffness direction D2. As a method for exhibiting anisotropy in bending stiffness, the thickness of the high-density section 11A may be varied in the circumferential direction Dr, as shown in Figure 13. The thickness of the high-density section 11A may be made thicker in areas parallel to the direction in which the load is applied than in other areas. This makes the direction in which the load is applied the high-stiffness direction D1. As shown in Figure 14, by providing three or more ribs 11r on a single support column 11 and arranging the ribs 11r so that their protruding direction radiates from the center of the support column 11, it is possible to improve the bending stiffness of the support column 11 while suppressing the exhibiting anisotropy in bending stiffness.

[0059] The function of the rib 11r is the same for the rib 12r provided on the connection part 12. By improving the rigidity of the support column 11 and the connection part 12 in this way, the support column 11 can be made thinner, or the number of support columns 11 connected to a single connection part 12 can be reduced, thereby suppressing collisions between support columns 11, between connection parts, and between support columns and connection parts when a large load is applied. Furthermore, even if such a collision occurs, the low rigidity of the inside of the support column 11 and the connection part 12 prevents the generation of a sudden and strong rebound force after the collision. As a result, the cushioning performance of the shoe component composed of the three-dimensional lattice structure 10 is improved.

[0060] The resin composition used in the construction of the support column 11 and the connecting part 12 can be prepared using, for example, olefin resins such as polyethylene, polypropylene, ethylene-vinyl acetate copolymer, ethylene-α-olefin copolymer, and polyolefin-based thermoplastic elastomer; styrene resins such as polystyrene, poly-α-methylstyrene, and styrene-based thermoplastic elastomer; polyester resins such as polyethylene terephthalate, polybutylene terephthalate, polylactic acid, and polyester-based thermoplastic elastomer; polyamide resins such as polyamide 6, polyamide 66, polyamide 610, and polyamide-based thermoplastic elastomer; polyurethane resins such as polyurethane and polyurethane-based thermoplastic elastomer; polyvinyl chloride; and various types of rubber. The resin composition may also contain various additives such as fillers, softeners, pigments, weathering agents, anti-aging agents, flame retardants, and antibacterial agents.

[0061] The support column 11 has a diameter of, for example, 0.5 mm or more. The diameter of the support column 11 may be 1.0 mm or more, or 1.5 mm or more. The diameter of the support column 11 may be, for example, 10.0 mm or less. The distance (center-to-center distance) between one connection part 12 in the three-dimensional lattice structure 10 and the other connection part 12 closest to that connection part 12 is, for example, 3 mm or more. The distance between the connection parts 12 may be 4 mm or more, or 5 mm or more. The distance between the connection parts 12 may be, for example, 25 mm or less. The distance between the connection parts 12 may be 20 mm or less.

[0062] The three-dimensional lattice structure 10 can be manufactured, for example, using a 3D printer. If the interior of the support columns 11 and connecting parts 12 of the three-dimensional lattice structure 10 is to be made of foam, it may be manufactured by first forming a non-foamed three-dimensional lattice structure using a 3D printer and then foaming the interior of the three-dimensional lattice structure.

[0063] As a method for foaming the inside of the support columns 11 and connecting parts 12, a method may be used in which a thermal decomposition type chemical blowing agent such as azodicarbonamide (ADCA) or bicarbonate is included in the resin composition that forms the central part of the support columns 11 and connecting parts 12. By creating a non-foaming three-dimensional lattice structure containing the chemical blowing agent and heating the three-dimensional lattice structure, the inside of the support columns 11 and connecting parts 12 can be foamed. As a method for foaming the inside of the support columns 11 and connecting parts 12, a method may be employed in which a physical blowing agent such as carbon dioxide, nitrogen, or hydrocarbon is impregnated into the non-foaming three-dimensional lattice structure under pressure, and the non-foaming three-dimensional lattice structure impregnated with the physical blowing agent is heated and depressurized. As a method for foaming the inside, a method using microballoons may be employed.

[0064] As a method for making the surface layers of the support columns 11 and connecting parts 12 high-density parts 11A and 12A, one can employ a method in which at least the surface layer is composed of a reaction-curable (crosslinkable) resin composition, a curing reaction (crosslinking reaction) is caused in the resin composition constituting the surface layer, making the surface layer less susceptible to softening by heat, and then the three-dimensional lattice structure is heated to make the degree of foaming of the surface layer lower than the degree of foaming of the interior.

[0065] The surface layer may be cured (crosslinked) by irradiation with active energy rays such as ultraviolet rays, electron beams, or X-rays, or by thermal curing (thermal crosslinking) through selective heating of the surface layer.

[0066] The resin composition constituting the surface layer does not need to be fully cured (fully crosslinked) before the interior is foamed. It may be partially cured first and then fully cured when the interior is foamed, or a separate post-curing step may be provided after foaming is complete to complete the curing reaction. The three-dimensional lattice structure 10 can be manufactured by various methods other than those described above.

[0067] The disclosures outlined above are merely illustrative examples, and the shoe components described in this disclosure are not limited to these examples. The above disclosures include the following:

[0068] (1) One embodiment of a shoe component is: It is composed of a three-dimensional lattice structure comprising multiple support columns and multiple connecting parts that connect the support columns to each other. The three-dimensional lattice structure is composed of a resin composition, The aforementioned three-dimensional lattice structure includes: A cylindrical high-density section extending in the longitudinal direction of the support column, having a density higher than the average density of each of the aforementioned plurality of support columns, One or both of the high-density portions are provided, which are shell-shaped high-density portions along the surface layer of the connection portions and have a density higher than the average density of each of the plurality of connection portions. In such a configuration, the shoe component exhibits improved cushioning.

[0069] (2) In shoe components, the three-dimensional lattice structure may be composed of a repetition of a unit structure consisting of the plurality of support columns and the connecting parts. In such an embodiment, the sole 2, which is a three-dimensional lattice structure 10, can easily distribute the load when it is applied by the user's foot. In such an embodiment of a shoe component, the three-dimensional lattice structure 10 can be easily manufactured and the three-dimensional lattice structure 10 can be made homogeneous overall.

[0070] (3) Shoe components are, When the thickness direction of the aforementioned three-dimensional lattice structure is defined as the vertical direction, In the aforementioned three-dimensional lattice structure, An upward-facing support column, which is the support column, extends upward from the aforementioned connection portion, This includes a downward-facing support column that extends downward from the aforementioned connection portion, Multiple upward-facing support columns are connected to each other, and the connection points may include such connection points that the distance between the multiple upward-facing support columns increases as they extend upward. In such an embodiment, localized concentration of load on shoe components during shoe use can be suppressed, potentially improving comfort.

[0071] (4) Shoe components are, The plurality of connection parts may include connection parts to which the plurality of upward-facing support columns are connected so that they have the same elevation angle with respect to one of the virtual planes passing through the connection part. In such an embodiment, the load applied to the shoe component can be distributed more effectively.

[0072] (5) Shoe components are, Multiple downward-facing support columns are connected to each other, and the connection portion may include a connection portion in which the multiple downward-facing support columns are connected such that the distance between them increases as they extend downward. Even in such an embodiment, localized concentration of load on shoe components during shoe use can be suppressed, potentially improving comfort.

[0073] (6) Shoe components are, The plurality of connection parts may include connection parts to which the plurality of downward-facing support columns are connected such that they have the same downward angle with respect to one of the virtual planes passing through the connection part. In such an embodiment, the load applied to the shoe component can be distributed more effectively.

[0074] (7) Shoe components are, When the plurality of upward-facing supports and the plurality of downward-facing supports are viewed from the direction of the normal to the virtual plane, the plurality of upward-facing supports and the plurality of downward-facing supports each extend radially from the connection point. Each of the plurality of downward-facing support columns may be located between adjacent upward-facing support columns in the circumferential direction, when the direction along the circle centered on the connection portion is defined as the circumferential direction. In such an embodiment, it is possible to avoid collision between the upward and downward support columns when a load is applied to the shoe component, thereby achieving good cushioning.

[0075] (8) Shoe components are, The number of upward-facing support columns and the number of downward-facing support columns are the same, Each of the aforementioned plurality of upward-facing support columns and the plurality of downward-facing support columns may be arranged at equal intervals in the circumferential direction. In such an embodiment, the load applied to the shoe component can be distributed more evenly.

[0076] (9) The multiple support columns in the shoe component may have different cross-sectional shapes at one point along the length and at another point different from that point. In such embodiments, it may become easier to design the rigidity and reduce the weight of shoe components.

[0077] (10) Shoe components are, Ribs may be provided in the high-density portion. In such an embodiment, the rigidity of the shoe component is improved.

[0078] (11) Shoe components are, The plurality of support columns have the high-density portion, The support column may be a hollow body having a cavity that is radially inward from the high-density portion and continuous in the longitudinal direction of the column. In such a configuration, even when a large load is applied and the support columns collide with each other or with the connection point, the support columns can be easily compressed and deformed, thus improving the cushioning performance of the shoe components.

[0079] (12) Shoe components are, The plurality of connection parts have the high-density parts, The connecting portion may be a hollow body having a cavity on the central side of the high-density portion. In such a configuration, even if a large load is applied and the connection parts collide with each other, or the support column and the connection part collide, the connection part can be easily compressed and deformed, thus improving the cushioning performance of the shoe component.

[0080] (13) Shoe components are, The plurality of connection parts have the high-density parts, The connecting portion is a hollow body having a cavity on the central side of the high-density portion, The cavities of the plurality of support columns may be in communication with each other through the cavities of the connecting portion. In such an embodiment, the movement of air inside improves the compressive deformability of the support columns and connecting parts, thereby improving the cushioning performance of the shoe components.

[0081] (14) The support column or connecting portion of the shoe component may be provided with a ventilation hole that connects the external space with the cavity. In such a configuration, the internal air can be expelled to the external space, improving the compressive deformability of the support columns and connecting parts, and thus improving the cushioning performance of the shoe components.

[0082] (15) At least one of the support column and the connecting portion in the shoe component may be made of resin foam in at least a portion of it. In such an embodiment, both the lightness and rigidity of the shoe components can be improved.

[0083] (16) Shoe components are, The plurality of support columns have the high-density portion, The support column may be made of resin foam at least radially inward from the high-density portion. In such an embodiment, both the lightness and rigidity of the shoe components can be improved.

[0084] (17) Shoe components are, The plurality of connection parts have the high-density parts, The connecting portion may be made of resin foam at least on the central side of the high-density portion. In such an embodiment, both the lightness and rigidity of the shoe components can be improved.

[0085] (18) Shoe components are, The aforementioned resin foam may have open cells. In such an embodiment, the cushioning properties of shoe components can be improved.

[0086] (19) The support column or connecting portion of the shoe component may be provided with ventilation holes that connect the external space with the open air bubble. In such an embodiment, the cushioning properties of shoe components can be improved.

[0087] (20) In shoe components, The aforementioned resin foam may be a closed-cell foam. In such an embodiment, the rigidity of the shoe component can be improved. [Examples]

[0088] The present invention will now be described in more detail with reference to examples, but the present invention is not limited to these examples.

[0089] We fabricated models of three types of three-dimensional lattice structures, as shown in Figure 15. Sample 1 is a model in which the entire structure is made of non-foamed resin with a support column thickness (diameter) of 2 mm. Sample 2 is a model in which the entire structure is made of non-foamed resin with a support column thickness (diameter) of 1 mm. Sample 3 is a modified version of Sample 1 in which the central parts of the support columns and connecting sections are foamed to create a high-density layer on the surface.

[0090] Figure 16 shows the results of evaluating the relationship between apparent density and compressive modulus for each sample. As can be seen from these results, simply reducing the diameter may reduce weight, but it results in insufficient rigidity, making it difficult to achieve sufficient cushioning. On the other hand, by incorporating a high-density layer on the surface, it is possible to achieve both lightness and cushioning properties, as this suppresses a decrease in the elastic modulus while maintaining lightness.

[0091] Next, the degree of foaming was varied, and the relationship between rebound stress and strain in response to the load was evaluated. The results are shown in Figure 17. This indicates that the greater the decrease in density, the greater the specific stress and maximum strain. Furthermore, this indicates that a delay effect occurs against the rapid rise in stress as density decreases.

[0092] From the above, it can be seen that the shoe component disclosed herein is effective in improving cushioning. [Explanation of Symbols]

[0093] 1: shoe, 2: sole, 3: upper 10: Three-dimensional lattice structure, 11: Support column, 11A: High-density section, 11B: Low-density section, 11r: Rib, 11h: Ventilation hole, 111: Upward support, 112 Downward support, 12: Connection part, 12A: High-density part, 12B: Low-density part, 12r: Rib, C: Unit structure, CN: Vertex, D1: High rigidity direction, D2: Low rigidity direction, Dd: radial direction, Dr: circumferential direction, Dx: Foot length direction, Dy: Foot width direction, Dz: Height direction DL: Length direction, P1: virtual plane, P2: plane, PL: face, SD: edge, θ1: elevation angle, θ2: depression angle

Claims

1. It is composed of a three-dimensional lattice structure comprising multiple support columns and multiple connecting parts that connect the support columns to each other. The three-dimensional lattice structure is composed of a resin composition, The aforementioned three-dimensional lattice structure includes: A cylindrical high-density section extending in the longitudinal direction of the support column, having a density higher than the average density of each of the aforementioned plurality of support columns, A shoe component provided with one or both of the high-density portions, which are shell-shaped high-density portions along the surface layer of the connection portions and have a density higher than the average density of each of the plurality of connection portions.

2. The shoe member according to claim 1, wherein the three-dimensional lattice structure is composed of a repeating unit structure consisting of the plurality of support columns and the connecting portion.

3. When the thickness direction of the aforementioned three-dimensional lattice structure is defined as the vertical direction, The aforementioned three-dimensional lattice structure includes: An upward-facing support column, which is the support column, extends upward from the aforementioned connection portion, This includes a downward-facing support column that extends downward from the aforementioned connection portion, The shoe member according to claim 1 or 2, wherein a plurality of upward-facing support columns are connected, and the plurality of connection portions are included in the plurality of connection portions such that the distance between the plurality of upward-facing support columns increases as they move upward.

4. The shoe member according to claim 3, wherein the plurality of connection parts include a connection part to which the plurality of upward support columns are connected so as to have the same elevation angle with respect to one of the virtual planes passing through the connection part.

5. The shoe member according to claim 3, wherein a plurality of downward-facing support columns are connected, and the plurality of connection portions include a connection portion in which the plurality of downward-facing support columns are connected such that the distance between them increases as they move downward.

6. The shoe member according to claim 5, wherein the plurality of downward-facing support columns are connected to the plurality of connection portions such that they have the same downward angle with respect to one of the virtual planes passing through the connection portion.

7. When the plurality of upward-facing supports and the plurality of downward-facing supports are viewed from the direction of the normal to the virtual plane, the plurality of upward-facing supports and the plurality of downward-facing supports each extend radially from the connection point. The shoe member according to claim 6, wherein each of the plurality of downward-facing support columns is located between adjacent upward-facing support columns in the circumferential direction when the direction along the circle centered on the connection portion is defined as the circumferential direction.

8. The number of upward-facing support columns and the number of downward-facing support columns are the same, The shoe member according to claim 7, wherein each of the plurality of upward support columns and the plurality of downward support columns is arranged to be at equal intervals in the circumferential direction.

9. The shoe member according to claim 1, wherein the plurality of support columns have different cross-sectional shapes at one location in the longitudinal direction and at another location different from that location.

10. The shoe member according to claim 1, wherein ribs are provided in the high-density portion.

11. The plurality of support columns have the high-density portion, The shoe member according to claim 1, wherein the support column is a hollow body having a cavity that is radially inward from the high-density portion and continuous in the longitudinal direction of the support column.

12. The plurality of connection parts have the high-density parts, The shoe member according to claim 1, wherein the connecting portion is a hollow body having a cavity on the central side of the high-density portion.

13. The plurality of connection parts have the high-density parts, The connecting portion is a hollow body having a cavity on the central side of the high-density portion, The shoe member according to claim 12, wherein the cavities of the plurality of support columns are in communication through the cavities of the connecting portion.

14. The shoe component according to claim 13, wherein the support column or the connecting portion is provided with a ventilation hole that connects the external space and the cavity.

15. The shoe component according to claim 1, wherein at least one of the support column and the connecting portion is made of resin foam in at least a portion thereof.

16. The plurality of support columns have the high-density portion, The shoe component according to claim 1, wherein the support column is composed of a resin foam at least radially inward from the high-density portion.

17. The plurality of connection parts have the high-density parts, The shoe component according to claim 1, wherein the connecting portion is made of resin foam at least on the central side of the high-density portion.

18. The shoe component according to claim 16 or 17, wherein the resin foam has open cells.

19. The shoe component according to claim 18, wherein the support column or the connecting portion is provided with a ventilation hole that connects the external space with the open air bubble.

20. The shoe component according to claim 16 or 17, wherein the resin foam is a closed-cell foam.

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