Shoe sole structure

Abstract

To provide a sole structure for shoes capable of further improving grip performance.SOLUTION: A sole structure 2 of a shoe 1 includes a sole body 3 extending in a longitudinal direction. The sole body 3 has a plurality of columnar portions 30 provided on a lower surface 3B thereof. The bottom surface 30a of each columnar portion 30 has a ground surface, and the outer circumferential surface of each columnar portion 30 has a plurality of protrusions 32, 32 ' protruding laterally.SELECTED DRAWING: Figure 6

Description

TECHNICAL FIELD

[0001] The present invention relates to a sole structure for footwear, and more particularly to an improvement in a structure for enhancing grip performance. BACKGROUND ART

[0002] JP 2021-79610 A, in paragraphs

[0028] ,

[0040] and FIG. 21, describes a footwear sole in which a large number of columnar projections (20bp) are provided on the bottom surface of the sole. According to such a sole structure, the anti-slip property and grip performance of the ground contact surface can be improved, the total area of the ground contact surface can be increased, and landing stability can be enhanced. SUMMARY OF THE INVENTION PROBLEMS TO BE SOLVED BY THE INVENTION

[0003] For the sole described in the above publication, there is a demand for further improvement in grip performance, and development of a sole structure from such a viewpoint has been desired.

[0004] The present invention has been made in view of such conventional circumstances, and an object to be achieved by the present invention is to provide a sole structure for footwear that can further enhance grip performance. MEANS FOR SOLVING THE PROBLEMS

[0005] A sole structure for footwear according to the present invention includes a sole main body extending in the front-rear direction. The sole main body has a plurality of columnar portions provided on a lower surface thereof. A bottom surface of each of the columnar portions has a ground contact surface, and an outer peripheral surface of each of the columnar portions has a plurality of convex portions protruding laterally. The sole body, columnar section, and protruding section are integrally molded. When a load is applied, the columnar section tilts so that the protruding section can make contact with the road surface.

[0006] According to the present invention, when the footwear lands, the members arranged on the lower surface of the sole main body Furthermore, it is molded integrally with the sole body.Multiple columnar sections make contact with the road surface, and at this time, the contact surface of the bottom of each columnar section provides grip. Furthermore, when the columnar section tilts due to the load acting on it when it makes contact with the road surface, the outer surface of the columnar section is provided. Furthermore, the columnar portion is integrally molded. The protrusions come into contact with the road surface, and at this time, the action of the protrusions further improves the grip while in contact with the ground.

[0007] In this invention, All of the multiple protrusions project laterally from the outer surface of each columnar section. .

[0008] In this invention, multiple protrusions are provided in the axial and circumferential directions from the base end to the tip end of the columnar portion.

[0009] In this invention, the tip of the protrusion has an edge-shaped corner.

[0010] In this invention, the upper surface of the sole body constitutes a foot contact surface that comes into direct or indirect contact with the sole of the shoe wearer's foot via an insole, and the sole body has both the function of a midsole that provides cushioning to the shoe wearer's foot and an outsole that makes contact with the road surface.

[0012] In this invention, the sole structure is molded using a 3D printer. Furthermore, in this invention, the 3D printer uses a fused deposition modeling (FDM) method.

[0013] In this invention, The protrusions are composed of annular portions that extend around the entire circumference of the outer surface of each columnar section. [Effects of the Invention]

[0014] As described above, the sole structure of the shoe according to the present invention has the effect of further improving grip. [Brief explanation of the drawing]

[0015] [Figure 1] This is an overall perspective view of a shoe to which the sole structure according to the present invention is applied. [Figure 2] This is a side view of the aforementioned shoe (Figure 1). [Figure 3] This is a rear view of the aforementioned shoe (Figure 1). [Figure 4] It is a bottom view of the aforementioned shoe (Figure 1). [Figure 5] It is a schematic plan view for explaining an example of a basic module in the three-dimensional elastic structure made of resin fibers that constitutes the aforementioned sole structure (Figure 1). [Figure 5A] It is a schematic plan view of an example of the first pattern arranged on the uppermost layer (first layer) of the aforementioned basic module (Figure 5). [Figure 5B] It is a schematic plan view of an example of the second pattern arranged in the layer immediately below the first layer (second layer) in the aforementioned basic module (Figure 5). [Figure 5C] It is a schematic plan view of an example of the third pattern arranged in the layer immediately below the second layer (third layer) in the aforementioned basic module (Figure 5). [Figure 5D] It is a schematic plan view of an example of the fourth pattern arranged in the layer immediately below the third layer (fourth layer) in the aforementioned basic module (Figure 5). [Figure 6] It is a partial vertical cross-sectional view in the front-rear direction of the sole main body and the columnar part of the aforementioned sole structure (Figure 1), which corresponds to the section taken along line VI-VI of Figure 7. [Figure 7] It is a cross-sectional view taken along line VII-VII of Figure 6. [Figure 8] It is a diagram for explaining the manner of deformation under load application in the aforementioned sole main body (Figure 6). [Figure 9] It is a diagram for explaining the manner of deformation under load application in the aforementioned sole main body (Figure 6). [Figure 10] It is a diagram showing the first modified example of Figure 6, which corresponds to the section taken along line X-X of Figure 11. [Figure 11] It is a cross-sectional view taken along line XI-XI of Figure 10. [Figure 12] It is a diagram for explaining the manner of deformation under load application in the aforementioned sole main body (Figure 10). [Figure 13] It is a diagram for explaining the manner of deformation under load application in the aforementioned sole main body (Figure 10). [Figure 14]This is a diagram showing the second modification of Fig. 6, which corresponds to the cross section taken along line XIV-XIV in Fig. 15. [Figure 15] This is a cross-sectional view taken along line XV-XV in Fig. 14. Detailed Description of the Invention

[0016] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Figs. 1 to 9 are diagrams for explaining a shoe sole structure according to one embodiment of the present invention, wherein Figs. 1 to 4 are external views of a shoe to which the present embodiment is applied, Figs. 5 to 5D are diagrams showing an example of a basic module of a three-dimensional elastic structure (three-dimensional filament structure) constituting the sole structure, Fig. 6 is a partial longitudinal cross-sectional view of the sole main body and columnar portions provided on the lower surface thereof (cross-sectional view taken along line VI-VI in Fig. 7), Fig. 7 is a cross-sectional view of the columnar portions (cross-sectional view taken along line VII-VII in Fig. 6), and Figs. 8 and 9 are diagrams for explaining the operation of the columnar portions.

[0017] Here, running shoes are taken as an example of the shoes. In the following description, upper (upper side / upper portion / top) and lower (lower side / lower portion / bottom) represent the positional relationship in the vertical direction of the shoe, front (front side / front portion / front) and rear (rear side / rear portion / rear) represent the positional relationship in the front-rear direction of the shoe, and the width direction refers to the left-right direction of the shoe. That is, taking the side view of Fig. 2 as an example, upper and lower respectively refer to the upper side and lower side of the same figure, front and rear respectively refer to the left side and right side of the same figure, and the width direction refers to the direction perpendicular to the paper surface of the same figure.

[0018] As shown in Figs. 1 to 4, the shoe 1 includes a sole structure 2 extending over the entire length of the shoe, and an upper U (illustrated by a chain line) provided thereon and covering the wearer's foot.

[0019] The sole structure 2 has a heel region H, a midfoot region M, and a forefoot region F, which correspond to the heel, midfoot (arch), and forefoot of the foot, respectively, and has a sole body 3 that extends in the front-to-back direction. The sole body 3 has a sole contact surface 3A (partially shown by a dotted line) on its upper surface that comes into direct or indirect contact with the sole of the shoe wearer's foot (not shown) via an insole or the like (not shown). The sole contact surface 3A forms a curved surface that curves gently in the front-to-back direction to conform to the shape of the sole of the wearer's foot.

[0020] An out-counter portion 3C is provided on the upper side of the sole body 3, primarily in the heel area H, and extends along the perimeter of the heel area H. The out-counter portion 3C rises upward from the sole body 3's foot-contact surface 3A to surround and support the heel of the wearer's foot. The shoe 1 is manufactured by fixing the lower part of the upper U to the foot-contact surface 3A and the out-counter portion 3C by adhesive or other means.

[0021] The lower surface 3B of the sole body 3 is provided with numerous columnar portions 30 (details described later) that extend substantially in the vertical direction. The term "substantially" is used here because, if the lower surface 3B of the sole body 3 has a flat shape extending along the front-to-back direction, then the columnar portions 30 extending downward from the flat lower surface 3B can be said to extend in the vertical direction. However, the lower surface 3B of the sole body 3 is not necessarily a flat shape extending along the front-to-back direction, and as in this example, it may have a convex curved shape that curves upward at the rear of the heel or at the toe. In such cases, the columnar portions 30 at the rear of the heel or at the toe extend in a direction inclined with respect to the vertical direction. Therefore, the expression "substantially in the vertical direction" is used to include such examples as well.

[0022] The sole body 3 is integrally molded together with the columnar portion 30 (and in this example, the out-counter portion 3C as well). Furthermore, the sole body 3, together with the columnar portion 30 (and the out-counter portion 3C as well), is composed of a three-dimensional elastic structure (three-dimensional three-dimensional structure).

[0023] This three-dimensional elastic structure can be manufactured using various methods. For example, in addition to the fused deposition modeling (FDM) method, which involves extruding molten resin from a nozzle while forming, selective laser sintering (SLS) which uses a laser to create a structure from powder material, and liquid resin photocuring (CLIP) which uses ultraviolet light to cure liquid resin, these methods can be used, but the invention is not limited to these methods. Therefore, the three-dimensional elastic structure may be a three-dimensional filament structure made of resin filaments, or it may be a three-dimensional lattice structure, etc. Furthermore, the three-dimensional elastic structure does not have to be a so-called box structure type surrounded on all sides by walls.

[0024] In this embodiment, the three-dimensional elastic structure is fabricated (molded / 3D printed) using a 3D printer. Preferably, an FDM (Fused Deposition Modeling) type 3D printer is used, and thermoplastic resins such as nylon, polyester, TPU (thermoplastic polyurethane), PU (polyurethane), thermoplastic elastomer, and rubber are used as the resin. In this embodiment, the three-dimensional elastic structure is a three-dimensional filament structure constructed by stacking many resin layers (resin layers) in the vertical direction with minute gaps between them, each layer being formed by arranging many resin filaments (resin fibers) so as to intersect each other in a horizontal plane.

[0025] With such a three-dimensional elastic structure, cushioning in the vertical direction can be achieved not only by the elasticity of the resin fibers themselves, but also by the minute gaps between adjacent resin layers in the vertical direction. For example, by using abrasion-resistant resin fibers, a sole structure can be realized that is excellent not only in cushioning and stability, but also in durability such as abrasion resistance and grip. In this case, there is no need to prepare both a midsole to ensure cushioning and stability for the wearer's foot and an outsole to ensure durability such as abrasion resistance and grip of the contact surface with the road, and to join them by adhesive or fusion, etc. The sole itself can function as both a midsole and an outsole.

[0026] Next, Figures 5 to 5D are diagrams illustrating the basic modules that constitute the three-dimensional elastic structure described above, and show an example of a basic module. Here, as an example of a three-dimensional elastic structure, we will consider one constructed by stacking numerous resin layers, each consisting of resin filaments arranged in a polygonal shape in a horizontal plane, in the vertical direction.

[0027] The basic module 50 shown in Figure 5 is represented by using different line types to indicate four layers of resin stacked vertically (perpendicular to the paper in the figure). (See solid lines, dashed lines, double dashed lines, and dotted lines in the figure.)

[0028] The basic module 50 consists of a first pattern 51, shown as a solid line and located on the top layer (first layer), as shown in Figures 5 and 5A; a second pattern 52, shown as a dashed line and located on the layer immediately below the first layer (second layer), as shown in Figures 5 and 5B; a third pattern 53, shown as a double dashed line and located on the layer immediately below the second layer (third layer), as shown in Figures 5 and 5C; and a fourth pattern 54, shown as a dotted line and located on the layer immediately below the third layer (fourth layer), as shown in Figures 5 and 5D. The first through fourth patterns are all made of resin filament.

[0029] The first pattern 51, as shown in Figure 5A, has a pair of octagonal frames 51a arranged at intervals and a square frame 52a placed between each frame 51a, with some of the frames constituting frame 52a being shared with the frames of each frame 51a. The second pattern 52, as shown in Figure 5B, has a pair of square frames 51b arranged at intervals and with chamfered vertices, and a square frame 52b placed between each frame 51b, with some of the frames constituting frame 52b being shared with the frames of each frame 51b. The third pattern 53, as shown in Figure 5C, has a pair of square frames 51c arranged at intervals and a square frame 52c placed between each frame 51c and with chamfered vertices, with some of the frames constituting frame 52c being shared with the frames of each frame 51c. The fourth pattern 54, as shown in Figure 5D, has a pair of square-shaped frames 51d arranged at intervals and an octagonal frame 52d placed between each frame 51d, with some of the frames constituting the frame 52d being shared with the frames of each frame 51d.

[0030] The first to fourth layers of the three-dimensional elastic structure 5 are constructed by arranging the first to fourth patterns 51 to 54 so as to completely cover each layer without any gaps. The three-dimensional elastic structure 5 is constructed by stacking the first to fourth layers vertically. Furthermore, in the region below the fourth layer, the third pattern 53 and the second pattern 52 are arranged in that order, and so on, with the first to fourth patterns 51 to 54 being repeated in ascending and descending order.

[0031] Thus, in the three-dimensional elastic structure 5, thin resin filaments are extended at predetermined intervals in the front-to-back and left-to-right directions to form each resin layer in the horizontal plane, and these resin layers are connected in the vertical (thickness) direction to construct a three-dimensional filament structure. Therefore, it can exhibit good elasticity not only in the front-to-back, left-to-right, and vertical directions, but in all directions as well, and it is possible to achieve a dramatic reduction in weight compared to conventional materials such as EVA and rubber.

[0032] Next, Figure 6 is a partial longitudinal section view of the sole body 3 and the columnar portion 30, and Figure 7 is a cross-sectional view of the columnar portion 30 (in each figure, the cross-sectional area is shown in black), and the left-right direction in Figure 6 corresponds to the front-to-back direction of the shoe. As shown in each figure, the columnar portion 30 has, for example, a cylindrical shape (it can also be a prism shape such as a triangular prism, square prism, or hexagonal prism), and its outer circumferential surface is provided with a plurality of protrusions 32, 32' that project laterally (i.e., radially outward). In this example, each protrusion 32, 32' is arranged on the outer circumferential surface of the columnar portion 30 at intervals of approximately 45° in the circumferential direction (therefore, radially). Note that in each figure, for the sake of illustration and explanation, the length of the columnar portion 30 and the size of each protrusion 32, 32' are exaggerated, but it is preferable that the lateral projection length of each protrusion 32, 32' is 0.2 mm or more.

[0033] As shown in Figures 6 and 7, each of the protrusions 32, 32' is provided in multiple locations in the axial and circumferential directions of the columnar portion 30. ,figure As shown in 6, multiple (three in this example) protrusions 32 are provided in the axial direction (up and down in this figure) from the base end (upper end in the figure) to the tip end (lower end in the figure) of the columnar portion 30. Similarly, multiple (two in this example) protrusions 32' are provided in the axial direction (up and down in this figure) from the base end (upper end in the figure) to the tip end (lower end in the figure) of the columnar portion 30. Each protrusion 32 is arranged at equal intervals in the axial direction of the columnar portion 30, but the intervals between each protrusion 32 do not have to be equal. Similarly, each protrusion 32' does not have to be arranged at equal intervals in the axial direction. In this example, the axial position of each protrusion 32' is offset (i.e., biased) with respect to the axial position of each protrusion 32, and each protrusion 32' is located between adjacent protrusions 32 in the axial direction, but the axial position of each protrusion 32' does not have to be offset with respect to each protrusion 32.

[0034] As shown in Figure 7, multiple (eight in this example) protrusions 32 are provided along the outer circumferential surface of the columnar portion 30, and similarly, multiple (eight in this example) protrusions 32' are provided along the outer circumferential surface of the columnar portion 30. Each protrusion 32 is arranged at equal intervals along the outer circumferential surface of the columnar portion 30 (the same applies to each protrusion 32'), but the spacing between each protrusion 32 does not have to be equal (the same applies to each protrusion 32'). In this example, the circumferential position of each protrusion 32' is offset (deviation) from the circumferential position of each protrusion 32, and each protrusion 32' is positioned between adjacent protrusions 32 in the circumferential direction. The reason for offsetting the circumferential position of each protrusion 32' with respect to the circumferential position of each protrusion 32 is, as will be described later, to prevent interference between the protrusions when the columnar portion 30 tilts and undergoes bending deformation under load.

[0035] The number of each protrusion 32, 32' is not limited to the number described above, and may be more or less. Furthermore, each protrusion 32, 32' may have a rectangular parallelepiped shape or a square prism shape, but the cross-sectional shape of each protrusion 32, 32' is not limited to a rectangle or a square, and may be other shapes. In any case, it is preferable that the tip of each protrusion 32, 32' has an edge-like corner.

[0036] The bottom surface 30a of the columnar portion 30 has a contact surface. The bottom surface 30a is provided with a plurality of protrusions 31 projecting downward, and each protrusion 31 has a bottom surface 31a. Figure 6 shows the state in which the bottom surface 30a of the columnar portion 30 is in contact with the road surface C via the protrusions 31. Note that these protrusions 31 may be omitted.

[0037] During the 3D printing process described above, the sole body 3 and the columnar portion 30 are molded together with the protrusions 31, 32, and 32'.

[0038] Next, the effects of this embodiment will be explained using Figures 8 and 9, with reference to Figures 6 and 7. In Figures 8 and 9, the left side shows the front of the shoe, and the right side shows the rear of the shoe.

[0039] When the shoe 1 lands, for example, when the heel of the sole body 3 lands first, the bottom surfaces 30a of the multiple columnar parts 30 at the heel make contact with the road surface C via the protrusions 31 (see Figure 6). At this time, the bottom surface 31a of each protrusion 31 provides grip to the road surface C.

[0040] Furthermore, when an impact load is applied to the rear heel end of the sole body 3 upon landing, the columnar portion 30 at the rear heel end tilts, or bends, due to this impact load. At this time, as shown in Figure 8 or Figure 9, the tip of each columnar portion 30 tilts backward or forward, causing each columnar portion 30 to bend backward or forward.

[0041] As shown in Figure 8, when each columnar portion 30 tilts backward and undergoes bending deformation, the front portion of each columnar portion 30 (left portion in the figure) stretches elastically, and the rear portion (right portion in the figure) contracts elastically. The opposite As shown in Figure 9, when each columnar portion 30 tilts forward and undergoes bending deformation, the rear portion of each columnar portion 30 (right side in the figure) stretches elastically, and the front portion (left side in the figure) contracts elastically.

[0042] As shown in Figures 8 and 9, the protrusions 32 (and 32') located on the elastically extended side of each columnar portion 30 come into contact with the road surface C. At this time, the action of the protrusions 32 (and 32') further improves the grip performance while in contact with the ground. In this case, since the protrusions 32 (and 32') have edge-shaped corners, when in contact with the ground, the frictional resistance of the edge portion of these corners generates a gripping force (the so-called "edge effect"), thereby further improving the grip performance.

[0043] On the other hand, as shown in Figures 8 and 9, the convex portions 32 (and 32') located on the elastically compressed side (right side in Figure 8, left side in Figure 9) of each columnar portion 30 are spaced closer together. However, even in this case, sufficient spacing is maintained between adjacent convex portions 32 (and 32') in the axial direction, thus preventing interference between adjacent convex portions 32 (and 32') in the axial direction. Note that in Figures 8 and 9, for illustrative purposes, only the convex portions 32 are shown on the elastically compressed side of each columnar portion 30, and the convex portions 32' are omitted.

[0044] After the shoe 1 lands, as the load moves from the heel region H of the sole body 3 through the midfoot region M to the forefoot region F, each columnar portion 30 may undergo deformation as shown in Figure 8 or Figure 9. Furthermore, when transitioning to the push-off phase, the forefoot region F flexes significantly at the metatarsophalangeal joint, and at this time, each columnar portion 30 at the metatarsophalangeal joint and toe area undergoes deformation as shown in Figure 8 or Figure 9.

[0045] Even in such cases, as with landing, the elastically stretched protrusions 32 (and 32') of each columnar portion 30 come into contact with the road surface C, and the action of the protrusions 32 (and 32') further improves grip during ground contact. Furthermore, even in this case, since the protrusions 32 (and 32') have edge-shaped corners, the so-called edge effect of the edge portion of these corners further improves grip. As a result, when pushing off with the toes, sufficient push-off force can be applied to the road surface C without slipping.

[0046] Furthermore, according to this embodiment, since the protrusions 32 and 32' arranged on the outer circumferential surface of each columnar portion 30 are arranged radially, even if the tilting direction of each columnar portion 30 is not only in the front-to-back direction as described above, but also in directions intersecting it (including diagonal and width directions), at least one of the protrusions 32 and 32' on the outer circumferential surface of each columnar portion 30 will come into contact with the road surface C, thereby further improving grip. For example, during side steps while moving, each columnar portion 30 will tilt in the width direction, and even in this case, sufficient grip can be achieved.

[0047] Furthermore, according to this embodiment, each protrusion 32, 32' is provided on the outer surface, i.e., the side surface, of each columnar portion 30, and since there are irregularities on the side surface of each columnar portion 30, even if the bottom surface 31a of each protrusion 31 and the bottom surface 30a of each columnar portion 30 are worn down due to use, the grip function can be maintained by the bending of each columnar portion 30. In addition, by providing each protrusion 32, 32' on the base end side of each columnar portion 30, this grip function can be maintained for a long period of time.

[0048] <First variation> Figures 10 to 13 show modified examples of the columnar portion according to the above embodiment, and correspond to Figures 6 to 9 of the above embodiment, respectively. In these figures, the same reference numerals as in the above embodiment indicate the same or equivalent parts.

[0049] In the above embodiment, each protrusion 32, 32' has a rectangular parallelepiped shape or a square prism shape, and examples were shown where the cross-sectional shape and longitudinal cross-sectional shape are rectangular or square. In this first modified example, each protrusion 32, 32' has a triangular prism shape, and its cross-sectional shape is rectangular or square, but the longitudinal cross-sectional shape is triangular. Furthermore, a protrusion 32'' with a right-angled triangular longitudinal cross-sectional shape is provided at the lower end of each columnar portion 30. In this case as well, the tips of each protrusion 32, 32', 32'' have edge-like corners. Also, in the above embodiment, a plurality of protrusions 31 were provided on the bottom surface 30a of the columnar portion 30, but in this first modified example, the protrusions 31 are omitted.

[0050] This first modification also produces the same effects as the above embodiment. , When the shoe 1 lands, during load transfer, and during push-off, the multiple columnar sections 30 tilt (i.e., undergo bending deformation), and as shown in Figure 12 or Figure 13, the tip of each columnar section 30 tilts backward or forward, causing each columnar section 30 to bend backward or forward. At this time, the convex section 32" (and convex sections 32, 32') located on the elastically stretched side of each columnar section 30 comes into contact with the road surface C. At this time, the action of the convex section 32" (and convex sections 32, 32') further improves grip during ground contact. In this case, since the convex section 32" (and convex sections 32, 32') has an edge-shaped corner, the so-called edge effect of the edge portion of the corner further improves grip during ground contact. As a result, when pushing off with the toes, sufficient push-off force can be applied to the road surface C without slipping.

[0051] In this first modified example, unlike the above embodiment, the bottom surface 30a of the multiple columnar parts 30 does not have protrusions 31, and Figure 10 shows a state in which the bottom surface 30a of the columnar parts 30 (and the lower surface of the protrusions 32") are in direct contact with the road surface C.

[0052] <Second variation> Figures 14 and 15 show other modifications of the columnar portion according to the above embodiment, corresponding to Figures 6 and 7 of the above embodiment, and Figures 10 and 11 of the first modification, respectively. In these figures, the same reference numerals as in the above embodiment and the first modification indicate the same or corresponding parts.

[0053] In the first modification described above, each protrusion 32, 32' has a triangular prism shape, with a rectangular or square cross-section and a triangular longitudinal cross-section. In this second modification, however, both the cross-sectional and longitudinal cross-sectional shapes of each protrusion 32, 32' are trapezoidal. In this case as well, the tips of each protrusion 32, 32' have edge-like corners. This second modification also provides the same effects as the above embodiment and the first modification.

[0054] <Third variation> In the above embodiment and the first and second modifications, examples were shown in which a plurality of laterally projecting protrusions 32, 32', and 32'' are provided on the outer circumferential surface of each columnar portion 30. However, these protrusions may also be generated by forming a plurality of recesses on the outer circumferential surface of each columnar portion 30. Furthermore, the protrusions do not have to be elongated laterally as shown in the above embodiment and the first and second modifications, but may be formed as part of the uneven shape formed on the outer circumferential surface of each columnar portion 30.

[0055] Furthermore, the protrusions may be ribs having a certain length in the axial or circumferential direction of each columnar portion 30. With respect to the circumferential direction, the protrusions may be annular portions extending around the entire circumference of the outer surface of each columnar portion 30 (i.e., in Figure 7 of the above embodiment, each protrusion 32 or 32' may be connected around the entire circumference).

[0056] <Fourth variation> In the above embodiments and the first to third modifications, examples were shown in which a plurality of protrusions 32, 32', and 32'' are arranged radially (at intervals of approximately 45° in the circumferential direction) on the outer surface of the columnar portion 30, but the present invention is not limited to this. Each of the protrusions 32, 32', and 32'' may be arranged at intervals of approximately 90° in the circumferential direction on the outer surface of the columnar portion 30.

[0057] <Fifth variation> In the above embodiments and the first to fourth modifications, each columnar portion 30 has a cylindrical or rectangular prism shape, and the size of its cross-sectional shape (circular, rectangular, etc.) does not change in the axial direction. However, the application of the present invention is not limited to this. The size of the cross-sectional shape (circular, rectangular, etc.) of each columnar portion 30 may change in the axial direction. That is, each columnar portion 30 may have a tapered shape in the axial direction. In particular, each columnar portion 30 may have an inverse tapered shape from the base end to the tip end (i.e., a shape in which the diameter gradually increases or the size increases as you move from the base end to the tip end). Such an inverse tapered shape is difficult to form using general molding methods that use molds, but it can be easily formed using a molding method that uses a 3D printer, as in the present invention.

[0058] <Sixth variation> In the above embodiments and the first to fourth modifications, each columnar portion 30 was described using examples of columnar shapes that extend in the axial direction (up and down direction), such as cylindrical or rectangular prism shapes, but the application of the present invention is not limited thereto. Each columnar portion 30 may be a design (tread design) that is generally applied to the bottom surface of a shoe, such as extending along the lower surface 3B of the sole body 3 in a rib shape or a long plate shape.

[0059] In that case, in order to more easily realize the effects of the present invention, it is preferable that each columnar part of the above design has a shape that makes it easy to fall over when it touches the ground. In the case of a rib-like design extending along the lower surface 3B of the sole body 3, the cross-sectional shape in the direction perpendicular to the longitudinal direction of the rib may be a trapezoidal shape (with the upper base (shorter side) on the lower surface 3B side and the lower base (longer side) on the contact surface side), so that each columnar part is more likely to collapse when it makes contact with the ground. Furthermore, in the case of long, plate-shaped designs extending along the lower surface 3B of the sole body 3, these designs may be made to intersect in a V-shape on the lower surface 3B of the sole body 3, or the side walls of each design may be made inclined, so that each design is more likely to collapse when it touches the ground.

[0060] <Other variations> The embodiments and modifications described above should be considered in all respects merely as examples of the invention and not as limiting. Those skilled in the art to which the invention relates can construct various modifications and other embodiments that employ the principles of the invention, without deviating from the spirit and essential features of the invention, by considering the teachings described above, even if not explicitly stated herein.

[0061] <Other application examples> In the above embodiments and modifications, examples were shown in which the sole structure was applied to running shoes. However, the application of the present invention is not limited to these examples. The present invention can be similarly applied to other sports shoes, including walking shoes and soccer shoes, as well as to general footwear. [Industrial applicability]

[0062] As described above, the present invention is useful for shoe sole structures that further improve grip. [Explanation of Symbols]

[0063] 1: Shoes 2: Sole structure 3: Sole 3A: Sole of foot contact surface 3B: Bottom side 30: Columnar part 30a: Base 32, 32', 32”: Convex part C: Road surface [Prior art documents] [Patent Documents]

[0064] [Patent Document 1] Japanese Patent Publication No. 2021-79610 (see paragraphs

[0028] ,

[0040] and Figure 21)

Claims

1. The sole structure of a shoe, It is equipped with a sole body that extends in the front-to-back direction, The sole body has a plurality of columnar portions provided on its lower surface, the bottom surface of each columnar portion has a contact surface, and the outer circumferential surface of each columnar portion has a plurality of protrusions projecting laterally. The sole body, the columnar portion, and the protrusion are integrally molded, When a load is applied, the columnar portion tilts so that the protrusion can come into contact with the road surface. A shoe sole structure characterized by the following features.

2. In claim 1, All of the aforementioned multiple protrusions project laterally from the outer surface of each columnar portion. A shoe sole structure characterized by the following features.

3. In claim 1, Multiple of the aforementioned protrusions are provided in the axial and circumferential directions from the base end to the tip end of the columnar portion. A shoe sole structure characterized by the following features.

4. In claim 1, The tip of the convex portion has an edge-shaped corner. A shoe sole structure characterized by the following features.

5. In claim 1, The upper surface of the sole body constitutes a foot contact surface that comes into direct or indirect contact with the sole of the shoe wearer's foot via an insole, and the sole body has both the function of a midsole that provides cushioning to the shoe wearer's foot and an outsole that makes contact with the road surface. A shoe sole structure characterized by the following features.

6. In claim 1, The sole structure is molded using a 3D printer. A shoe sole structure characterized by the following features.

7. In claim 6, The aforementioned 3D printer uses a fused deposition modeling (FDM) method. A shoe sole structure characterized by the following features.

8. In claim 1, The aforementioned protrusion is composed of an annular portion extending around the entire circumference of the outer surface of each columnar portion. A shoe sole structure characterized by the following features.

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