Footwear and method for manufacturing the same

Abstract

To provide footwear that is difficult to form shape defects when forming a foot cover part using the three-dimensional stacked modeling method of the optical modeling method.SOLUTION: Footwear 1A has a footbed portion 110 that supports the sole of a wearer's foot and is provided with a ground surface 112, and a foot cover portion 120 that covers the instep of the wearer's foot. At least a portion of the footbed portion 110 and at least a portion of the foot cover portion 120 comprise a single modeling object 2 fabricated by a photolithographic three-dimensional stacked modeling method, and a raised portion 123 is provided on an outer surface 121 defined by the modeling object 2 of the foot cover portion 120.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to footwear provided with a footbed portion and a foot cover portion typified by sandals and shoes, and a method for manufacturing the same.

Background Art

[0002] In recent years, it has become popular to produce a shaped object having a desired three-dimensional shape by a three-dimensional layer forming method, and its use is also being promoted in the field of footwear. For example, Japanese Patent Application Laid-Open No. 2018-187363 (Patent Document 1) and US Patent Publication No. 2018 / 0049514 (Patent Document 2) disclose shoes including soles manufactured by a three-dimensional layer forming method.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] Generally, when manufacturing a sole provided in a shoe by a three-dimensional layer forming method, since the sole has a corresponding thickness, its formability is relatively high, and the risk of shape defects occurring during shaping is low. However, when manufacturing a foot cover portion that covers the toenail of the wearer's foot by a three-dimensional layer forming method, the formability may be significantly inferior depending on the shaping method and the shaping method.

[0005] Specifically, when manufacturing the foot cover using stereolithography in a three-dimensional additive manufacturing method, if the foot cover is sequentially additively manufactured from the contact surface side along a direction perpendicular to the contact surface of the footwear, the foot cover is thin and has relatively flat parts. As a result, the liquid resin or liquid rubber used as the raw material sags under its own weight before it hardens, which leads to the occurrence of shape defects during manufacturing.

[0006] Therefore, the present invention has been made to solve these problems, and aims to provide footwear and a method for manufacturing the same that are less prone to shape defects when the foot cover portion is fabricated by stereolithography in three-dimensional additive manufacturing. [Means for solving the problem]

[0007] The footwear according to the present invention comprises a footbed portion that supports the sole of the wearer's foot and has a contact surface, and a foot cover portion that covers the instep of the wearer's foot. At least a part of the footbed portion and at least a part of the foot cover portion are It consists of multiple cured layers formed by the sequential layering and hardening of a liquid resin when exposed to light of a specific wavelength. It consists of a single molded object. The outer surface of the foot cover portion defined by the above molded object is provided with raised portions. Furthermore, the aforementioned raised portion is positioned to extend from the front end to the rear end of the foot cover portion.

[0008] A method for manufacturing footwear according to the present invention is a method for manufacturing footwear including a footbed portion that supports the sole of the wearer's foot and has a contact surface, and a foot cover portion that covers the instep of the wearer's foot, comprising the steps of manufacturing the footbed portion and manufacturing the foot cover portion. The steps of manufacturing the footbed portion and manufacturing the foot cover portion are The liquid resin is exposed to light of a specific wavelength. As a result, at least a portion of the footbed portion is released from the ground surface side in a direction perpendicular to the ground surface. Layered Sequential stacking By hardening It is shaped, and subsequently, at least a part of the foot cover portion is Layered Sequential stacking By hardeningThe process involves creating a single object through molding. In the process of manufacturing the foot cover portion, the outer surface of the foot cover portion that will be defined by the molded object is So that it reaches from the front end to the rear end of the foot cover portion mentioned above. A raised section is provided. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide footwear and a method for manufacturing the same that are less prone to shape defects when fabricating the foot cover portion using stereolithography three-dimensional additive manufacturing. [Brief explanation of the drawing]

[0010] [Figure 1] This is a perspective view of a sandal according to Embodiment 1. [Figure 2] Figure 1 is a plan view of the sandal shown. [Figure 3] This is a cross-sectional view of the sandal shown in Figure 1, along the line III-III shown in Figure 2. [Figure 4] This is a cross-sectional view of the sandal shown in Figure 1, along the line IV-IV shown in Figure 2. [Figure 5] This is a schematic diagram showing a method for manufacturing sandals according to Embodiment 1. [Figure 6] This is a schematic diagram showing a method for manufacturing sandals according to Embodiment 1. [Figure 7] This is a schematic diagram showing a method for manufacturing sandals according to Embodiment 1. [Figure 8] This is a schematic diagram showing the manufacturing method of sandals according to Comparative Example 1. [Figure 9] This is a schematic diagram illustrating the problems that arise when sandals are manufactured according to the sandal manufacturing method described in Comparative Example 2. [Figure 10] This is a schematic diagram illustrating the effects of manufacturing sandals according to the sandal manufacturing method of Embodiment 1. [Figure 11] This is a plan view of the sandal according to the first to third modified examples. [Figure 12]It is a plan view of a sandal according to the 4th to 6th modification examples. [Figure 13] It is a plan view of a sandal according to the 7th to 9th modification examples. [Figure 14] It is a perspective view of a sandal according to the 10th and 11th modification examples. [Figure 15] It is a perspective view of a sandal according to the 12th and 13th modification examples. [Figure 16] It is a plan view of a sandal according to the 14th modification example. [Figure 17] It is a cross-sectional view of the sandal shown in Fig. 16 along the line XVII-XVII shown in Fig. 16. [Figure 18] It is a cross-sectional view of the sandal shown in Fig. 16 along the line XVIII-XVIII shown in Fig. 16. [Figure 19] It is a perspective view of a sandal according to the 15th modification example. [Figure 20] It is a front view of the sandal shown in Fig. 19. [Figure 21] It is a perspective view of a sandal according to the 17th modification example. [Figure 22] It is a plan view of the sandal shown in Fig. 21. [Figure 23] It is a cross-sectional view of the sandal shown in Fig. 21 along the line XXIII-XXIII shown in Fig. II. [Figure 24] It is a perspective view of a shoe according to Embodiment 2. [Figure 25] It is a plan view of the shoe shown in Fig. 24. [Figure 26] It is a cross-sectional view of the shoe shown in Fig. 24 along the line XXVI-XXVI shown in Fig. 25. [Figure 27] It is an exploded view of the shoe shown in Fig. 24.

Embodiments for Carrying Out the Invention

[0011] Hereinafter, embodiments of the present invention will be described in detail with reference to the figures. The embodiments shown below illustrate the application of the present invention to sandals and shoes as footwear. In the embodiments shown below, the same or common parts are denoted by the same reference numerals in the figures, and their descriptions will not be repeated.

[0012] <Embodiment 1> Figure 1 is a perspective view of the sandal according to Embodiment 1, and Figure 2 is a plan view of the sandal shown in Figure 1. Figures 3 and 4 are cross-sectional views of the sandal shown in Figure 1 along lines III-III and IV-IV shown in Figure 2, respectively. First, the configuration of the sandal 1A according to this embodiment will be described with reference to Figures 1 to 4.

[0013] As shown in Figures 1 to 4, the sandal 1A comprises a sandal body 100A including a footbed portion 110 and a foot cover portion 120. The sandal body 100A is made of a single component and consists of a fabricated object 2 manufactured by a three-dimensional additive manufacturing method using stereolithography, which will be described later.

[0014] The footbed portion 110 is the part that supports the sole of the wearer's foot, and has a footbed area 111 on its upper surface and a contact surface 112 on its lower surface. The footbed area 111 is an area that can support the sole of the wearer's foot.

[0015] In the sandal 1A according to this embodiment, the upper edge of the footbed portion 110 is raised so that the wearer's foot is positioned on the footbed portion 110 when worn. Therefore, the upper surface of the footbed portion 110 has a concave shape overall, and the portion defining the bottom of this concave upper surface corresponds to the footbed region 111.

[0016] The footbed area 111 is preferably made of a material that is non-slip and flexible, and the contact surface 112 is preferably made of a non-slip material. In the sandal 1A according to this embodiment, the footbed area 111 and the contact surface 112 are made of a part of the sandal body 100A, which is a single component, so both the footbed area 111 and the contact surface 112 are made of a non-slip and flexible material. However, the footbed area 111 and the contact surface 112 may be individually made of components with different materials or hardness.

[0017] The foot cover portion 120 is the part that covers the instep of the wearer's foot and is located above the footbed portion 110. In the sandal 1A according to this embodiment, the foot cover portion 120 has a strap-like (i.e., band-like) shape.

[0018] As shown in Figure 2, the footbed portion 110 of the sandal 1A, when viewed from above (i.e., along a direction perpendicular to the contact surface 112), is divided along the front-to-back direction (up-down direction in Figure 2) which corresponds to the length direction of the wearer's foot, into a forefoot portion R1 that supports the toes and ball of the foot, a midfoot portion R2 that supports the arch of the wearer's foot, and a rearfoot portion R3 that supports the heel of the wearer's foot.

[0019] Furthermore, as shown in Figure 2, when viewed from above, the sandal 1A is divided along the left-right direction (left-right direction in the figure) that matches the width direction of the wearer's foot, into an inner foot portion (the S1 side shown in the figure) corresponding to the midline side of the foot in its anatomical orientation (i.e., the side closer to the midline) and an outer foot portion (the S2 side shown in the figure) corresponding to the side of the foot opposite to the midline side in its anatomical orientation (i.e., the side further from the midline).

[0020] As shown in Figures 1 to 4, the foot cover portion 120 extends along the left-right direction such that it has a generally curved shape when viewed along the front-to-back direction. One end of the foot cover portion 120 is connected to the inner foot end of the footbed portion 110, and the other end of the foot cover portion 120 is connected to the outer foot end of the footbed portion 110.

[0021] As a result, the opening 150 is formed by the periphery of the upper surface of the footbed portion 110 located behind the foot cover portion 120 and the rear end of the foot cover portion 120, and a hollow space is provided between the footbed portion 110 and the foot cover portion 120. Therefore, the wearer's foot is inserted into the hollow space through the opening 150, making it possible to wear the sandal 1A.

[0022] In addition to the opening 150 described above, the sandal 1A according to this embodiment has a front opening 151 formed by the periphery of the upper surface of the footbed portion 110 located in front of the foot cover portion 120 and the front end of the foot cover portion 120. When worn, the wearer's toes are exposed to the outside through this front opening 151.

[0023] In this embodiment, the sandal 1A is provided with a protruding portion 123 as a raised portion at a predetermined position on the foot cover portion 120, the details of which will be described later.

[0024] The material of the sandal body 100A is not particularly limited, but it is preferable that it be a resin or rubber material that can be fabricated using stereolithography and that the fabricated sandal body 100A has appropriate flexibility, elongation, durability, and elasticity. More specifically, if the sandal body 100A is made of resin, it can be, for example, polyolefin resin, ethylene-vinyl acetate copolymer (EVA), polyamide thermoplastic elastomer (TPA, TPAE), thermoplastic polyurethane (TPU), or polyester thermoplastic elastomer (TPEE). On the other hand, if the sandal body 100A is made of rubber, it can be, for example, butadiene rubber (BR).

[0025] The sandal body 100A can also be made of a polymer composition. In that case, examples of polymers to be included in the polymer composition include olefin polymers such as olefin elastomers and olefin resins. Examples of olefin polymers include polyethylene (e.g., linear low-density polyethylene (LLDPE), high-density polyethylene (HDPE), etc.), polypropylene, ethylene-propylene copolymer, propylene-1-hexene copolymer, propylene-4-methyl-1-pentene copolymer, propylene-1-butene copolymer, ethylene-1-hexene copolymer, ethylene-4-methyl-pentene copolymer, ethylene-1-butene copolymer, 1-butene-1-hexene copolymer, 1-butene-4-methyl-pentene, ethylene-methacrylic acid copolymer, ethylene-methyl methacrylate copolymer, ethylene- Examples of polyolefins include ethyl methacrylate copolymer, ethylene-butyl methacrylate copolymer, ethylene-methyl acrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-butyl acrylate copolymer, propylene-methacrylic acid copolymer, propylene-methyl methacrylate copolymer, propylene-ethyl methacrylate copolymer, propylene-butyl methacrylate copolymer, propylene-methyl acrylate copolymer, propylene-ethyl acrylate copolymer, propylene-butyl acrylate copolymer, ethylene-vinyl acetate copolymer, and propylene-vinyl acetate copolymer.

[0026] Furthermore, the polymer may be an amide polymer such as an amide elastomer or an amide resin. Examples of amide polymers include polyamide 6, polyamide 11, polyamide 12, polyamide 66, and polyamide 610.

[0027] Furthermore, the polymer may be an ester-based polymer such as an ester-based elastomer or an ester-based resin. Examples of ester-based polymers include polyethylene terephthalate and polybutylene terephthalate.

[0028] Furthermore, the above polymer may be a urethane-based polymer such as a urethane elastomer or a urethane resin. Examples of urethane-based polymers include polyester polyurethane and polyether polyurethane.

[0029] Furthermore, the above polymer may be a styrene-based polymer such as a styrene elastomer or a styrene resin. Examples of styrene elastomers include styrene-ethylene-butylene copolymer (SEB), styrene-butadiene-styrene copolymer (SBS), hydrogenated SBS (styrene-ethylene-butylene-styrene copolymer (SEBS)), styrene-isoprene-styrene copolymer (SIS), hydrogenated SIS (styrene-ethylene-propylene-styrene copolymer (SEPS)), styrene-isobutylene-styrene copolymer (SIBS), styrene-butadiene-styrene-butadiene (SBSB), and styrene-butadiene-styrene-butadiene-styrene (SBSBS). Examples of styrene resins include polystyrene, acrylonitrile styrene resin (AS), and acrylonitrile butadiene styrene resin (ABS).

[0030] Furthermore, the above polymer may be, for example, an acrylic polymer such as polymethyl methacrylate, a urethane acrylic polymer, a polyester acrylic polymer, a polyether acrylic polymer, a polycarbonate acrylic polymer, an epoxy acrylic polymer, a conjugated diene polymer acrylic polymer and its hydrogenated derivatives, a urethane methacrylic polymer, a polyester methacrylic polymer, a polyether methacrylic polymer, a polycarbonate methacrylic polymer, a polyester urethane acrylate, a polycarbonate urethane acrylate, a polyether urethane acrylate, an epoxy methacrylic polymer, a conjugated diene polymer methacrylic polymer and its hydrogenated derivatives, a polyvinyl chloride resin, a silicone elastomer, butadiene rubber, isoprene rubber (IR), chloroprene rubber (CR), natural rubber (NR), styrene-butadiene rubber (SBR), acrylonitrile-butadiene rubber (NBR), butyl rubber (IIR), etc.

[0031] As mentioned above, it is preferable that the sandal body 100A is made of a material that is non-slip and flexible, and among the materials mentioned above, it is particularly preferable that it be made of urethane acrylate. When the sandal body 100A is made of urethane acrylate, it will not only have excellent durability and elongation, but also sufficient elasticity. As mentioned above, since the sandal body 100A is manufactured by stereolithography, a curing agent will be included as a secondary component.

[0032] Figures 5 to 7 are schematic diagrams illustrating the manufacturing method of sandals according to this embodiment. Next, the manufacturing method of sandals according to this embodiment will be described with reference to Figures 5 to 7.

[0033] As described above, in the sandal 1A according to this embodiment, the sandal body 100A, including the footbed portion 110 and the foot cover portion 120, is made up of a single material 2 manufactured by stereolithography. The sandal body 100A can be manufactured, for example, using a three-dimensional additive manufacturing apparatus 1000 as shown in Figures 5 to 7.

[0034] The three-dimensional additive manufacturing apparatus 1000 manufactures objects using the stereolithography method of three-dimensional additive manufacturing. Here, the stereolithography method of three-dimensional additive manufacturing is a manufacturing method that uses a photocurable liquid resin or liquid rubber that hardens when exposed to light of a specific wavelength as the main raw material, and sequentially builds up hardened parts by irradiating it with light of that specific wavelength, thereby producing an object of the desired shape. For example, ultraviolet light can be used as the specific wavelength of light, in which case ultraviolet-curable resin or rubber will be used as the main raw material. Note that the liquid resin or liquid rubber used as the main raw material is not limited to a one-component type, but may also be a two-component type, etc.

[0035] As shown in Figures 5 to 7, the three-dimensional additive manufacturing apparatus 1000 comprises a light source (not shown), a storage tank 1001, a platform 1002, and a lifting mechanism 1003. The storage tank 1001 is a part for storing liquid resin 200 and the like as raw materials, and the platform 1002 is for holding and moving the manufactured object 2. The lifting mechanism 1003 moves the platform 1002 in the vertical direction.

[0036] As shown in Figure 5, in the three-dimensional additive manufacturing apparatus 1000, first, the platform 1002 is moved by the lifting mechanism 1003 so that the lower surface of the platform 1002 is in contact with the liquid surface of the liquid resin 200 or the like. In this state, light of a specific wavelength emitted from a light source is irradiated onto the vicinity of the liquid surface of the liquid resin 200 or the like in a predetermined pattern, thereby exposing it. As a result, the liquid resin 200 or the like in the part located near the liquid surface adheres to the lower surface of the platform 1002 and hardens in layers, forming the first hardened layer.

[0037] Next, the platform 1002 is moved upward by a predetermined amount (i.e., in the direction of arrow DR1 in the figure) by the lifting mechanism 1003, so that the lower surface of the first cured layer is in contact with the surface of the liquid resin 200 or the like. In this state, light of a specific wavelength emitted from the light source is irradiated onto the vicinity of the liquid surface of the liquid resin 200 or the like in a predetermined pattern, thereby exposing it. As a result, the liquid resin 200 or the like located near the liquid surface hardens in layers with the lower surface of the first cured layer attached to it, and the second cured layer is formed.

[0038] The process for forming this second hardened layer (i.e., the process of moving the platform 1002 and the exposure process of the liquid resin 200, etc.) is repeated, and as shown in Figure 6, multiple hardened layers are sequentially stacked downwards (i.e., in the direction of arrow DR2 shown in the figure), thereby the sandal body 100A is formed. During this process, the footbed portion 110 and the foot cover portion 120 are formed consecutively. At this time, a protruding portion 123 is provided as a raised portion at a predetermined position on the foot cover portion 120.

[0039] Then, as shown in Figure 7, after all parts of the sandal body 100A have been fabricated, the platform 1002 is lifted further upward by the lifting mechanism 1003, and the sandal body 100A is separated from the liquid resin 200 etc. stored in the storage tank 1001 and removed from the three-dimensional additive manufacturing apparatus 1000. At this point, the sandal body 100A, after fabrication is complete, is not yet fully hardened and is in a relatively soft state. Therefore, the removed sandal body 100A is subjected to a separate heat treatment to harden it completely, and then washed and dried to complete the production of the sandal body 100A.

[0040] Thus, in the sandal manufacturing method according to this embodiment, the footbed portion 110 is sequentially additively manufactured from the side of the contact surface 112 along a direction perpendicular to the contact surface 112 using a stereolithography three-dimensional additive manufacturing method, and thereafter the foot cover portion 120 is sequentially additively manufactured. In other words, in the sandal manufacturing method according to this embodiment, the direction perpendicular to the contact surface 112 of the sandal body 100A coincides with the direction in which multiple hardened layers are sequentially stacked to manufacture the sandal body 100A (i.e., the direction of arrow DR2 shown in the figure).

[0041] Figure 8 is a schematic diagram showing the manufacturing method of sandals according to Comparative Example 1. Next, with reference to Figure 8, the manufacturing method of sandals according to Comparative Example 1 will be described, and the advantages of the manufacturing method of sandals according to this embodiment described above compared to the manufacturing method of sandals according to Comparative Example 1 will be explained.

[0042] As shown in Figure 8, the sandal manufacturing method according to Comparative Example 1 is similar to the sandal manufacturing method according to the embodiment described above in that it manufactures a sandal 1X by producing a sandal body 100X made of a single material using a three-dimensional additive manufacturing device 1000 with stereolithography. However, the direction in which the sandal body 100X is additively manufactured in the sandal manufacturing method according to Comparative Example 1 differs from that of the sandal manufacturing method according to the embodiment described above.

[0043] Specifically, in the sandal manufacturing method according to Comparative Example 1, the sandal body 100X is sequentially built up along the front-to-back direction from the forefoot R1 (see Figure 2) side to the rearfoot R3 (see Figure 2) side using a stereolithography three-dimensional additive manufacturing method. In other words, in the sandal manufacturing method according to Comparative Example 1, the front-to-back direction of the sandal body 100X coincides with the direction in which the multiple hardened layers are sequentially built up (the direction of arrow DR2 shown in the figure).

[0044] Thus, when the sandal body 100X is built up in layers along its front-to-back direction, there are no parts to be built in the direction in which the sandal body 100X is built up (i.e., the DR2 direction shown in the figure) when viewed from the aforementioned hollow section, which is a relatively large space between the footbed section 110 and the foot cover section 120. Therefore, the difficulty of the build process is relatively low, and the sandal body 100X can be built with high precision.

[0045] However, on the other hand, because the length of the sandal body 100X in the direction of additive manufacturing increases, the number of repetitions of the aforementioned movement and exposure processes performed to form multiple hardened layers increases. Consequently, the time required for manufacturing increases, resulting in lower productivity.

[0046] Furthermore, due to the relationship between the shape of the sandal body 100X being fabricated and its orientation (i.e., orientation) during fabrication, it becomes necessary to form a support part 2' separately from the sandal body 100X, as shown in Figure 8, in order to maintain the shape of the relatively soft sandal body 100X during fabrication. This support part 2' must be separated and removed from the sandal body 100X after fabrication. This results in additional problems such as an increase in the manufacturing process and the generation of waste materials.

[0047] On the other hand, in the sandal manufacturing method according to the embodiment described above, the sandal body 100A is additively manufactured along a direction perpendicular to the contact surface 112. As a result, the length of the sandal body 100A in the additive manufacturing direction is reduced, and the number of repetitions of the above-described moving and exposure processes performed to form multiple hardened layers can be significantly reduced compared to the sandal manufacturing method according to Comparative Example 1. Consequently, the time required for manufacturing is shortened, and productivity is significantly improved.

[0048] Furthermore, due to the relationship between the shape of the sandal body 100A being molded and its orientation (i.e., orientation) during molding, it is possible to maintain the shape of the relatively soft sandal body 100A during molding without providing the support part 2' that was necessary in the sandal manufacturing method according to Comparative Example 1. Therefore, it does not involve an increase in the manufacturing process and does not generate waste materials, which is advantageous in this respect.

[0049] However, on the other hand, if the sandal body 100A is additively fabricated along a direction perpendicular to the contact surface 112, it becomes difficult to fabricate the foot cover portion 120 with high precision due to the relationship between the shape of the sandal body 100A being fabricated and its orientation (i.e., orientation) during fabrication. If no measures are taken, there is a risk that shape defects may occur in the foot cover portion 120. This point will be explained in detail below.

[0050] Figure 9 is a schematic diagram illustrating the problems that arise when sandals are manufactured according to the sandal manufacturing method of Comparative Example 2, and Figure 10 is a schematic diagram illustrating the effects of manufacturing sandals according to the sandal manufacturing method of this embodiment described above.

[0051] As shown in Figure 9, the sandal manufacturing method according to Comparative Example 2 is similar to the sandal manufacturing method according to the embodiment described above in that the sandal 1Y is manufactured by additively forming the sandal body 100Y along a direction perpendicular to the contact surface 112, but no measures are taken to prevent the occurrence of the shape defects described above.

[0052] In this case, the foot cover portion 120 is positioned in the direction in which the sandal body 100Y is laminated (i.e., the DR2 direction shown in the figure) when viewed from the aforementioned hollow portion, which is a relatively large space provided between the footbed portion 110 and the foot cover portion 120. Because the foot cover portion 120 is thin and has a relatively flat shape, the liquid resin 200 used as raw material tends to sag under its own weight before it hardens, making it prone to shape defects as shown in the figure at position P shown in Figure 9. Since these shape defects mainly occur on the outer surface 121 of the foot cover portion 120, the aesthetic appearance is greatly impaired. Furthermore, if shape defects occur not only on the outer surface 121 but also on the inner surface 122 of the foot cover portion 120, it will lead to a decrease in wearing comfort.

[0053] In this regard, as shown in Figure 10, in the sandal manufacturing method according to this embodiment, a protruding portion 123 is provided as a raised portion at a predetermined position (i.e., position P shown in the figure) on the outer surface 121 of the foot cover portion 120, as will be described in detail later. As a result, the outer surface 121 of that portion is not flat but curved or bent, which prevents the sagging of the liquid resin 200, etc. As a result, shape defects will not occur as shown in the figure, and it will be possible to prevent damage to the aesthetic appearance and deterioration of the wearing comfort.

[0054] Generally, the surface of the wearer's instep has a curved shape, with its ridge located on the medial side of the foot, relative to the center of the foot's width. Furthermore, the curved shape of the wearer's instep is gentler and flatter towards the toes, and more pronounced towards the heel. Therefore, to improve the fit to the foot, the inner surface 122 of the foot cover portion 120 is usually shaped to conform to this curved shape of the wearer's instep. In such cases, the foot cover portion 120 as a whole is also often constructed with a curved shape.

[0055] Therefore, the foot cover portion 120 covering the front part of the instep of the wearer's foot is often flatter than the foot cover portion 120 covering the rear part of the instep of the wearer's foot. Consequently, when the foot cover portion 120 is manufactured, the aforementioned shape defects are more likely to occur in the foot cover portion 120 covering the front part of the instep of the wearer's foot.

[0056] In view of this, in the sandal 1A according to this embodiment, as shown in Figures 1 to 4, the above-mentioned protruding portion 123 is provided on the foot cover portion 120 at a position that covers the front part of the instep of the wearer's foot, and furthermore, the protruding portion 123 is provided on the foot cover portion 120 at a position that covers the front part of the instep of the wearer's foot, corresponding to the ridge line of the surface of the instep of the wearer's foot.

[0057] As a result, by using the sandal 1A according to this embodiment and the method for manufacturing the sandal according to this embodiment, it becomes possible to prevent shape defects from occurring when the foot cover portion 120 is fabricated by stereolithography in three-dimensional additive manufacturing.

[0058] In addition, in the case of the sandal 1A according to this embodiment, the thickness of the foot cover portion 120 in the area where the protruding portion 123 is provided becomes larger in proportion to the surrounding area, thereby increasing the rigidity of the foot cover portion 120 in that area. Therefore, it becomes possible to suppress deformation of the foot cover portion 120, and a secondary effect is obtained in that the sandal can maintain its fit over a long period of time.

[0059] Here, from the viewpoint of suppressing shape defects during the molding process as described above, it is preferable that the raised portion, such as the ridge portion 123 described above, be located in one of the following ranges, referring to Figure 2. The range is determined by defining L as the distance from the front end position to the rear end position of the footbed region 111 in the anterior-posterior direction, which corresponds to the length direction of the wearer's foot, and dividing the sandal 1A with a virtual plane perpendicular to this anterior-posterior direction.

[0060] Preferably, the raised portion (protrusion 123) is provided at any of the locations within range A shown in Figure 2. That is, it is preferable that the raised portion (protrusion 123) is provided at any of the locations within range A shown in Figure 2, which is the range enclosed by a virtual plane formed at a distance of 0.05 × L in the front-rear direction from the front end position of the footbed area 111 and a virtual plane formed at a distance of 0.50 × L in the front-rear direction from the front end position of the footbed area 111.

[0061] More preferably, the raised portion (protrusion 123) is provided at any of the locations in range B shown in Figure 2. That is, it is preferable that the raised portion (protrusion 123) is provided at any of the locations in range B shown in Figure 2, which is the range sandwiched between a virtual plane formed at a distance of 0.15 × L in the front-rear direction from the front end position of the footbed area 111 and a virtual plane formed at a distance of 0.30 × L in the front-rear direction from the front end position of the footbed area 111.

[0062] Alternatively, it is preferable that the raised portion (protruding portion 123) is positioned to cover one-quarter of the metatarsal bones of the wearer's foot, extending posteriorly from the anterior end of the metatarsal bones, when the wearer has a standard foot size that fits the size of the sandal.

[0063] By providing a raised portion, such as the aforementioned ridge 123, in either area A or area B, or in a quarter of the metatarsal area, it is possible to reliably prevent shape defects from occurring during the fabrication of the foot cover portion 120 using the stereolithography three-dimensional additive manufacturing method. The shape of the raised portion is not limited to the shape of the ridge 123 shown in the figure, and can be modified in various ways.

[0064] In this embodiment, the sandal 1A has a ridge portion 123 on the outer surface 121 of the foot cover portion 120, extending from the front end to the rear end of the foot cover portion 120. More specifically, the ridge portion 123 extends linearly so as to intersect in the left-right direction, which matches the width direction of the wearer's foot. The front end of the ridge portion 123 is located on the inner foot side (i.e., the S1 side) of the center in the left-right direction, and the rear end of the ridge portion 123 is located on the outer foot side (i.e., the S2 side) of the center in the left-right direction. More specifically, the ridge portion 123 extends linearly along an oblique direction so as it moves from its front end to its rear end, it gradually moves away from the inner foot end of the foot cover portion 120.

[0065] Furthermore, while there are no particular restrictions on the protruding height of the raised portion, such as the ridge portion 123 described above, it is preferable that it protrudes within a range of 3.0 mm to 10.0 mm relative to the perimeter of the portion on which the raised portion is provided. If the protruding height of the raised portion is 3.0 mm or less, the effect of suppressing shape defects during molding described above may not be sufficiently obtained, and if the protruding height of the raised portion is 10.0 mm or more, the design may be compromised.

[0066] Furthermore, the width of the raised portion (or, in the case where the raised portion is composed of the aforementioned protruding portion 123, the width in the direction perpendicular to its extension direction) is preferably 1.5 mm or more and 30.0 mm or less, and more preferably 5.0 mm or more and 15.0 mm or less.

[0067] As mentioned above, the curved shape of the instep surface of the wearer's foot is gentler and flatter towards the toes and more curved towards the heel. In view of this, when a raised portion is provided to span from the front end to the rear end of the foot cover portion 120, and the height and width of the raised portion are varied to consider the design, it is preferable to make the height and width of the raised portion at the rear end of the foot cover portion 120 greater than the height and width of the raised portion at the front end of the foot cover portion 120. Note that when a raised portion is provided to span from the front end to the rear end of the foot cover portion 120, as in this embodiment, it includes not only the case where the raised portion is composed of a ridge portion 123, as in this embodiment, but also the case where the raised portion is composed of a plurality of protrusions 124, as in the 12th and 13th modified examples described later.

[0068] <Variations 1 through 13> Figures 11(A) to 11(C) are plan views of sandals relating to the first to third modified examples, respectively, and Figures 12(A) to 12(C) are plan views of sandals relating to the fourth to sixth modified examples, respectively. Figures 13(A) to 13(C) are plan views of sandals relating to the seventh to ninth modified examples, respectively, and Figures 14(A) and 14(B) are perspective views of sandals relating to the tenth and eleventh modified examples, respectively. Also, Figures 15(A) and 15(B) are perspective views of sandals relating to the twelfth and thirteenth modified examples, respectively. Hereinafter, the sandals 1A1 to 1A13 relating to the first to thirteenth modified examples based on the above-described embodiment 1 will be explained with reference to these Figures 11 to 15.

[0069] As shown in Figures 11 to 15, the sandals 1A1 to 1A13 according to the first to thirteenth modified examples differ from the sandal 1A according to Embodiment 1 described above in the shape and / or position of the raised portion provided on the outer surface 121 of the foot cover portion 120. However, the other configurations are the same as those of the sandal 1A according to Embodiment 1 described above, and they are manufactured by a manufacturing method similar to the manufacturing method of the sandal according to Embodiment 1 described above.

[0070] These first to thirteenth modified sandals 1A1 to 1A13 all have raised portions on the outer surface 121 of the foot cover portion 120, thereby suppressing the occurrence of shape defects during the molding process described above. On the other hand, by differentiating the shape and / or position of the raised portions from the sandal 1A of the first embodiment described above, the aesthetic appearance is varied in various ways.

[0071] As shown in Figures 11(A) to 11(C), Figure 12(A), and Figure 12(B), in the sandals 1A1 to 1A5 according to the first to fifth modified examples, the protruding portion 123, which serves as a raised portion, is provided so as to extend from the front end to the rear end of the foot cover portion 120. More specifically, the protruding portion 123 extends linearly so as to intersect in the left-right direction, which matches the width direction of the wearer's foot, with the front end of the protruding portion 123 located on the inner side of the foot relative to the center in the left-right direction, and the rear end of the protruding portion 123 located on the outer side of the foot relative to the center in the left-right direction.

[0072] Here, as shown in Figures 11(A) to 11(C), in the sandals 1A1 to 1A3 relating to the first to third modified examples, the protruding portion 123 extends in a smoothly curved manner, and as shown in Figures 12(A) and 12(B), in the sandals 1A4 and 1A5 relating to the fourth and fifth modified examples, the protruding portion 123 extends in a bent manner.

[0073] As shown in Figures 12(C) and 13(A) to 13(C), in the sandals 1A6 to 1A9 relating to the sixth to ninth modified examples, the protruding portion 123, which serves as a raised portion, is provided so as to extend from the front end to the rear end of the foot cover portion 120. More specifically, the protruding portion 123 extends linearly so as to intersect in the left-right direction, which matches the width direction of the wearer's foot, and both the front and rear ends of the protruding portion 123 are located on the inner side of the foot, relative to the center in that left-right direction.

[0074] Here, as shown in Figure 12(C), in the sandal 1A6 relating to the sixth modified example, the protruding portion 123 extends linearly along the front-rear direction, and as shown in Figures 13(A) to 13(C), the seventh or In the ninth modified example, the sandals 1A7 to 1A9 have a protruding portion 123 that extends in a smoothly curved manner.

[0075] As shown in Figure 14(A), in the tenth modified example, the sandal 1A10 has a protruding ridge 123 that extends from the front end to the rear end of the foot cover portion 120. More specifically, the protruding ridge 123 extends linearly so as to intersect in the left-right direction, which matches the width direction of the wearer's foot. The front end of the protruding ridge 123 is located on the inner side of the foot, relative to the center in the left-right direction, and the rear end of the protruding ridge 123 is located on the outer side of the foot, relative to the center in the left-right direction. The protruding ridge 123 extends linearly along an oblique direction so as it moves from its front end to its rear end, gradually moving away from the inner end of the foot cover portion 120, and the protruding height of the protruding ridge 123 is configured to differ from part to part.

[0076] As shown in Figure 14(B), in the 11th modified example, the sandal 1A11 has a protrusion 124 as a raised portion, located near the front end of the foot cover portion 120. More specifically, the protrusion 124 has a spot-like shape and is located on the inner side of the foot, relative to the center in the left-right direction that matches the width direction of the wearer's foot.

[0077] As shown in Figure 15(A), in the 12th modified example, the sandal 1A12 has a plurality of protrusions 124 as raised parts, which are provided near the front end of the foot cover portion 120. More specifically, each of the plurality of protrusions 124 has a spot-like shape, and the plurality of protrusions 124 are scattered in the central part of the left-right direction that matches the width direction of the wearer's foot, and in positions further inward from the central part.

[0078] As shown in Figure 15(B), in the 13th modified example, the sandal 1A13 has multiple protrusions 124 as raised parts, arranged in a dotted line from the front end to the rear end of the foot cover portion 120. Of these dotted line-arranged multiple protrusions 124, the protrusions 124 provided on the front end of the foot cover portion 120 are located on the inner side of the foot, relative to the center in the left-right direction that matches the width direction of the wearer's foot, while the protrusions 124 provided on the rear end of the foot cover portion 120 are located on the outer side of the center in the left-right direction.

[0079] Even when using the sandals 1A1 to 1A13 according to the first to thirteenth modified examples illustrated above, the same effects as those described in Embodiment 1 above can be obtained, and shape defects can be prevented when the foot cover portion 120 is fabricated by stereolithography.

[0080] <14th variation> Figure 16 is a plan view of the sandal according to the 14th modified example, and Figures 17 and 18 are cross-sectional views of the sandal shown in Figure 16 along the lines XVII-XVII and XVIII-XVIII shown in Figure 16, respectively. Hereinafter, the sandal 1A14 according to the 14th modified example based on the above-described embodiment 1 will be described with reference to Figures 16 to 18. The sandal 1A14 according to this 14th modified example is manufactured by a manufacturing method similar to the manufacturing method of the sandal according to the above-described embodiment 1.

[0081] As shown in Figures 16 to 18, the sandal 1A14 according to the 14th modified example, like the sandal 1A6 according to the 6th modified example described above (see Figure 12(C)), has a ridge portion 123 provided on the outer surface 121 of the foot cover portion 120, which extends linearly along the front-to-back direction such that both its front and rear ends are located on the inner side of the foot, relative to the central part in the left-to-right direction that matches the width direction of the wearer's foot.

[0082] In addition, in the sandal 1A14, a groove 125 is provided on the inner surface 122 of the foot cover portion 120 where the protruding portion 123 is formed, extending along the direction in which the protruding portion 123 extends. That is, the groove 125 extends linearly along the front-to-back direction such that both its front and rear ends are located on the inner side of the foot, relative to the center in the left-to-right direction that corresponds to the width direction of the wearer's foot.

[0083] The portion of the foot cover 125 provided on the inner side of the foot, relative to the center in the left-right direction that matches the width of the wearer's foot, corresponds to the area where the ridge of the instep surface of the wearer's foot is located. Therefore, with this configuration, when worn, the groove 125 provided on the inner surface 122 of the foot cover portion 120 overlaps with the ridge of the instep surface of the wearer's foot, thereby improving the fit.

[0084] Therefore, by using the sandal 1A14 according to this 14th modification, it becomes possible to prevent shape defects from occurring when the foot cover portion 120 is fabricated by stereolithography, just as in the case of the sandal 1A according to Embodiment 1 described above. Furthermore, it becomes possible to obtain a sandal with improved fit.

[0085] <15th variation> Figure 19 is a perspective view of the sandal according to the 15th modification, and Figure 20 is a front view of the sandal shown in Figure 19. Hereinafter, the sandal 1A15 according to the 15th modification based on the above-described embodiment 1 will be described with reference to Figures 19 and 20. The sandal 1A15 according to this 15th modification is manufactured by a manufacturing method similar to the manufacturing method of the sandal according to the above-described embodiment 1.

[0086] As shown in Figures 19 and 20, the sandal 1A15 according to the 15th modified example has basically the same external shape as the sandal 1A according to Embodiment 1 described above (see Figures 1 to 4, etc.), but its configuration differs from the sandal 1A according to Embodiment 1 described above in that the sandal body 100A has a three-dimensional lattice structure.

[0087] More specifically, the sandal 1A15, like the sandal 1A of Embodiment 1 described above, comprises a sandal body 100A including a footbed portion 110 and a foot cover portion 120, and this sandal body 100A is made of a single component. This sandal body 100A, made of a single component, consists of a fabricated object 2 manufactured by stereolithography, and this fabricated object 2 is configured to have a three-dimensional lattice structure, taking advantage of the feature of stereolithography, which allows for the production of fabricated objects with desired three-dimensional shapes.

[0088] More specifically, the three-dimensional lattice structure can be constructed using a three-dimensional mesh structure obtained by, for example, distorting interconnected unit cell structures to match the external shape of the sandal body 100A. Various types of unit cell structures can be applied, such as rectangular prism lattices, diamond lattices, octahedral lattices, double pyramidal lattices, or these lattices with various supports added.

[0089] Because the sandal body 100A has a three-dimensional lattice structure, the footbed portion 110 can be given high deformability, resulting in a sandal that is comfortable to wear with excellent cushioning, as well as a sandal that is stable when worn. Furthermore, because the sandal body 100A has a three-dimensional lattice structure, it is possible to make the sandal lightweight relative to its size, and also a sandal that is highly breathable. From the viewpoint of weight reduction and breathability, it is preferable to have a porosity of 50% or more in the footbed portion 110.

[0090] Thus, the sandal according to this 15th modified example has a sandal body 100A having a three-dimensional lattice structure. 1A15 These shoes (recovery sandals) are particularly suitable for use after high-intensity exercise or activity (running, various ball games, mountain climbing, etc.) or during and before / after long flights (airplane travel), and are especially effective in relieving fatigue through pressure distribution, supporting the arch of the foot, and providing support against pronation (the inclination of the heel).

[0091] Here, the sandal 1A15 is similar to the sandal 1A in the embodiment 1 described above, in which a protruding portion 123 is provided as a raised portion at a predetermined position on the outer surface 121 of the foot cover portion 120.

[0092] Therefore, by using the sandal 1A15 according to this 15th modified example, it is possible to prevent shape defects from occurring when the foot cover portion 120 is fabricated by stereolithography, just as with the sandal 1A according to Embodiment 1 described above. Furthermore, it is possible to create a lightweight sandal with excellent comfort that can be particularly suitable for recovery purposes.

[0093] In this 15th modified example, the sandal body 100A is shown as having a three-dimensional lattice structure, but the sandal body 100A may have a three-dimensional structure other than a three-dimensional lattice structure. For example, the sandal body 100A may have a three-dimensional structure based on a triple-periodic minimal surface such as a Schwartz P structure or a gyroid structure, with added thickness, or it may have a three-dimensional structure based on a surface structure such as an octet structure or a cubic structure with added thickness.

[0094] Furthermore, the entire sandal body 100A does not need to be composed of unit structures of the same size; the size may vary from part to part. Moreover, the entire sandal body 100A does not need to have the same three-dimensional structure; the footbed portion 110 and the foot cover portion 120 may have different three-dimensional structures, or the footbed portion 110 may have different three-dimensional structures in the front-to-back or left-to-right directions, for example, it may be configured to have partially different three-dimensional structures.

[0095] <16th variation> Figure 21 is a perspective view of the sandal according to the 16th modified example, and Figure 22 is a plan view of the sandal shown in Figure 21. Figure 23 is a cross-sectional view of the sandal shown in Figure 21 along the line XXIII-XXIII shown in Figure 22. Hereinafter, the sandal 1A16 according to the 16th modified example based on the above-described embodiment 1 will be described with reference to Figures 21 to 23. The sandal 1A16 according to this 16th modified example is manufactured by a manufacturing method similar to the manufacturing method of the sandal according to the above-described embodiment 1.

[0096] As shown in Figures 21 to 23, the sandal 1A16 according to the 16th modified example differs in its configuration from the sandal 1A according to the 1st embodiment described above (see Figures 1 to 4, etc.) in that it does not have a front opening 151.

[0097] More specifically, in the sandal 1A16, the foot cover portion 120 has a semi-dome shape, and its lower end is connected to the front end, the inner end, and the outer end of the footbed portion 110.

[0098] Accordingly, in the sandal 1A16, the foot cover portion 120 is positioned closer to the front end in the front-to-back direction compared to the sandal 1A according to the first embodiment described above. Since this part of the foot cover portion 120 closer to the front end covers a flatter portion of the wearer's instep, in the sandal 1A16 according to this 16th modification, which does not have such a front opening 151, a protruding portion 123 is provided to reach this portion.

[0099] Therefore, even in the case of the sandal 1A16 according to this 16th modified example, since the protruding portion 123 as a raised portion is provided at a predetermined position on the outer surface 121 of the foot cover portion 120, it is possible to prevent shape defects from occurring when the foot cover portion 120 is fabricated by stereolithography three-dimensional additive manufacturing, just as in the case of the sandal 1A according to the first embodiment described above.

[0100] The protruding portion 123 only needs to be provided at least in either range A or range B shown in the figure (see Embodiment 1 described above for details), but it may also be provided beyond these ranges. For example, considering the design, the front end of the protruding portion 123 may be extended further forward in the front-rear direction so that it reaches the front end of the forefoot portion R1 (i.e., the toe end).

[0101] Furthermore, even when the foot cover portion 120 is configured to have a semi-dome shape, as in the 16th modified example, the raised portion may be formed by a ridge portion 123 or projection portion 124 as shown in the first to 15th modified examples described above. In this case as well, the ridge portion 123 or projection portion 124 only needs to be provided at at least one of the above-described range A or range B, but it may also be provided further beyond this, for example, at the front end of the forefoot portion R1.

[0102] <Embodiment 2> Figure 24 is a perspective view of the shoe according to Embodiment 2, and Figure 25 is a plan view of the shoe shown in Figure 24. Figure 26 is a cross-sectional view of the shoe shown in Figure 24 along the line XXVI-XXVI shown in Figure 25, and Figure 27 is an exploded view of the shoe shown in Figure 24. The shoe 1B according to this embodiment will be described below with reference to Figures 24 to 27.

[0103] As shown in Figures 24 to 27, the shoe 1B is a sock-like structure that covers almost the entire foot of the wearer (i.e., the part from the ankle downwards), and comprises a shell 100B, a sole body 130, and an upper body 140. The upper part of the shoe 1B is provided with an opening 150 for inserting the foot, and a space is formed inside the shoe 1B into which the wearer's foot is inserted when wearing it. As a result, the shoe 1B can be worn by inserting the wearer's foot into the internal space through the opening 150.

[0104] In shoe 1B, the sole body 130 is housed in the shell 100B, and the upper body 140 is housed in the shell 100B so as to be positioned on top of the sole body 130. Consequently, the sole body 130 is sandwiched between the shell 100B and the upper body 140.

[0105] As a result, in shoe 1B, the footbed portion 110, which supports the sole of the wearer's foot, is composed of the bottom of the shell 100B, the sole body 130, and the bottom of the upper body 140, and the foot cover portion 120, which covers the instep of the wearer's foot, is composed of a semi-dome-shaped portion erected from the front end, the inner end, and the outer end of the bottom of the shell 100B, and a semi-dome-shaped portion erected from the front end, the inner end, and the outer end of the bottom of the upper body 140.

[0106] The shell 100B is composed of a single component formed in a bag shape. The shell 100B includes a bottom portion that constitutes the footbed portion 110 described above, and a shoe upper portion connected to the entire circumference of the periphery of the bottom portion. The semi-dome-shaped portion of the shell 100B that constitutes the foot cover portion 120 described above is made up of a part of this shoe upper portion. The shell 100B covers the bottom surface and circumferential surface of the sole body 130 and the surface of the upper body 140, and has an opening 126 at its upper end. The shell 100B also has a contact surface 112 on the lower surface of its bottom portion.

[0107] The shell 100B consists of a fabricated object 2 manufactured by stereolithography in a three-dimensional additive manufacturing method. Here, the shell 100B is manufactured by going through a manufacturing process that is similar to the manufacturing process of the sandal body 100A in the sandal manufacturing method according to Embodiment 1 described above.

[0108] In other words, the shell 100B is manufactured by sequentially additive manufacturing using the stereolithography method with the three-dimensional additive manufacturing apparatus 1000 (see Figures 5 to 7, etc.) described above, starting from the side of the contact surface 112 along a direction perpendicular to the contact surface 112, and then sequentially additively manufacturing the shoe upper portion described above, which will form part of the foot cover portion 120.

[0109] The material of the shell 100B is not particularly limited, but it can be the same as the material of the sandal body 100A described in Embodiment 1 above.

[0110] The sole body 130 is made of a flat material that can be elastically deformed. The sole body 130 is located in the lower space within the shell 100B, close to the contact surface 112.

[0111] The sole body 130 can be made of virtually any material as long as it is elastically deformable, but it is preferable that it be made of a material that has moderate strength while also having excellent cushioning properties. From this viewpoint, for example, the sole body 130 can be made of a resin foam material containing a resin material as the main component and a foaming agent or crosslinking agent as a secondary component. Alternatively, a rubber foam material containing a rubber material as the main component and a plasticizer, foaming agent, reinforcing agent, or crosslinking agent as a secondary component may be used.

[0112] The upper body 140 constitutes the part of the shoe 1B that comes into contact with the wearer's foot, and is made of a flexible, deformable bag-like material. The upper body 140 is located in the upper space near the opening 126 within the space provided inside the shell 100B.

[0113] The upper surface of the bottom of the upper body 140 defines a footbed area 111, which is a region capable of supporting the sole of the wearer's foot. Furthermore, the upper end of the upper body 140 is positioned to protrude outward from the opening 126, and the portion of the upper body 140 that protrudes from this opening 126 constitutes the aforementioned opening 150.

[0114] The upper body 140 can be made of virtually any material as long as it is flexible and can be deformed, but preferably, woven fabrics, knitted fabrics, nonwoven fabrics, synthetic leather, resins, etc. are used. In particular, as will be described later, if woven fabrics, knitted fabrics, nonwoven fabrics, etc. made of heat-shrinkable synthetic fibers are used, the fit to the wearer's foot can be made more comfortable. Examples of heat-shrinkable synthetic fibers include those mainly composed of polyester, polyurethane, etc.

[0115] In other words, if the upper body 140 is to be made of a heat-shrinkable synthetic fiber woven, knitted, or nonwoven fabric, it is first formed into a bag shape, and the last described later is inserted inside and then heat-treated. The heat causes the upper body 140 to shrink, causing it to conform to the molded surface of the last, and this changed shape is then maintained.

[0116] Therefore, by preparing a last that corresponds to the shape of the wearer's foot and using it to mold the upper body 140 as described above, it is possible to produce an upper body 140 that fits the wearer's foot. Furthermore, if the heat treatment using the last described above is performed with the upper body 140 assembled into the shell 100B, the upper body 140 will also fit the shell 100B, further improving the fit.

[0117] As shown in Figures 24 to 26, in the shoe 1B, a protruding portion 123 is provided as a raised portion at a predetermined position on the foot cover portion 120. More specifically, the protruding portion 123 is provided on the outer surface 121 of the foot cover portion 120, similar to the case of the sandal 1A according to Embodiment 1 described above, and more specifically, it is provided on the exposed surface of the shell 100B, which is the portion that defines the outer surface 121 of the foot cover portion 120.

[0118] The protruding portion 123 extends linearly so as to intersect in the left-right direction, corresponding to the width direction of the wearer's foot. The front end of the protruding portion 123 is located on the inner side of the foot (i.e., the S1 side) of the central part in the left-right direction, and the rear end of the protruding portion 123 is located on the outer side of the foot (i.e., the S2 side) of the central part in the left-right direction. Furthermore, the protruding portion 123 extends linearly along an oblique direction so as it moves from its front end to its rear end, it gradually moves away from the inner end of the foot cover portion 120.

[0119] Here is the form of implementation. In a stateIn the shoe 1B described above, as in the case of the sandal 1A according to Embodiment 1, the shell 100B is sequentially built up from the contact surface 112 side using stereolithography. Therefore, when viewed from the relatively large hollow space between the footbed 110 and the foot cover 120, the foot cover 120, which is the part to be built, is positioned in the direction in which the shell 100B is built up. This will be particularly effective.

[0120] Therefore, if no measures are taken, there is a risk that a shape defect may occur on the outer surface 121 of the foot cover portion 120 (i.e., the exposed surface of the shell 100B), but in this embodiment In a state In the shoe 1B described above, similar to the sandal 1A according to Embodiment 1, a protruding portion 123 is provided as a raised portion on the outer surface 121 of the foot cover portion 120. As a result, the outer surface 121 of this portion is not flat but curved or bent, which prevents the liquid resin 200 from dripping down. Therefore, shape defects will not occur, and it will be possible to prevent damage to the aesthetic appearance and a decrease in wearing comfort.

[0121] In this embodiment, unlike the sandal 1A of the first embodiment described above, the shoe 1B does not have a front opening 151 (see Figure 1, etc.) that exposes the wearer's toes near the front end. Therefore, in the shoe 1B, the foot cover portion 120 is located closer to the front end in the front-to-back direction compared to the sandal 1A. Since this part of the foot cover portion 120 closer to the front end covers a flatter part of the wearer's instep, the shoe 1B of this embodiment, which does not have such a front opening 151, is provided with a protruding portion 123 that reaches this part.

[0122] As explained above, in the case of the shoe 1B according to this embodiment, just as in the case of the sandal 1A according to Embodiment 1 described above, it is possible to prevent shape defects from occurring when the foot cover portion 120 is fabricated by stereolithography in three-dimensional additive manufacturing.

[0123] The protruding portion 123 only needs to be provided at least in either range A or range B shown in the figure (see Embodiment 1 described above for details), but it may also be provided beyond these ranges. For example, considering the design, the front end of the protruding portion 123 may be extended further forward in the front-rear direction so that it reaches the front end of the forefoot portion R1 (i.e., the toe end).

[0124] <Summary of Disclosures in Embodiments, etc.> The features disclosed in the embodiments described above and their variations can be summarized as follows:

[0125] [Note 1] A footbed portion that supports the sole of the wearer's foot and has a contact surface, It includes a foot cover that covers the instep of the wearer's foot, At least a portion of the footbed and at least a portion of the foot cover are made from a single object produced by stereolithography. Footwear in which a raised portion is provided on the outer surface of the foot cover portion as defined by the above-mentioned molded object.

[0126] [Note 2] The above footbed portion has a footbed area on its upper surface that is capable of supporting the sole of the wearer's foot, The footwear described in Appendix 1, wherein, when L is defined as the distance from the front end to the rear end of the footbed area in the anterior-posterior direction corresponding to the length of the wearer's foot, and the range of the footwear is defined by dividing the footwear with a virtual plane perpendicular to the anterior-posterior direction, the raised portion is provided at a position within the range sandwiched between a virtual plane formed at a distance of 0.05 × L from the front end along the anterior-posterior direction and a virtual plane formed at a distance of 0.50 × L from the front end along the anterior-posterior direction.

[0127] [Note 3] The footwear according to Appendix 2, wherein the raised portion is provided at a position within the range enclosed by a virtual plane formed at a distance of 0.15 × L along the front-to-back direction from the front end position, and a virtual plane formed at a distance of 0.30 × L along the front-to-back direction from the front end position.

[0128] [Note 4] Footwear as described in any of the appendices 1 to 3, wherein the protruding height of the raised portion is 3.0 mm or more and 10.0 mm or less.

[0129] [Note 5] The footwear described in any of the appendices 1 to 4, wherein the above-mentioned raised portion consists of a linearly extending ridge.

[0130] [Note 6] The footwear described in Appendix 5, wherein the above-mentioned protrusions extend so as to intersect in the left-right direction, corresponding to the width direction of the wearer's foot.

[0131] [Note 7] The footwear according to Appendix 6, wherein a groove is provided on the inner surface of the foot cover portion in the area where the above-mentioned protrusion is formed, extending along the direction in which the protrusion extends.

[0132] [Note 8] The footwear according to Appendix 6 or 7, wherein the front end of the protruding portion is located on the inner side of the foot than the central portion in the left-right direction.

[0133] [Note 9] The footwear described in Appendix 8, wherein the above-mentioned protrusion extends so as it moves from its front end to its rear end, it gradually moves away from the inner foot end of the foot cover portion.

[0134] [Note 10] The footwear according to Appendix 8 or 9, wherein the rear end of the protruding portion is located on the outer side of the foot than the central portion in the left-right direction.

[0135] [Note 11] The above-mentioned molded object has a three-dimensional lattice structure, and is a footwear as described in any of the appendices 1 to 10.

[0136] [Note 12] The footwear in question is a sandal, The footwear according to any one of the appendices 1 to 11, wherein the portion of the molded object that constitutes the foot cover portion has a strap shape connected to the inner foot end and the outer foot end of the portion of the molded object that constitutes the footbed portion.

[0137] [Note 13] The footwear in question is a shoe, The footwear according to any one of the appendices 1 to 11, wherein the portion of the molded object that constitutes the foot cover portion is made up of a part of the shoe upper portion that is connected to the entire circumference of the periphery of the portion of the molded object that constitutes the footbed portion when viewed in a direction perpendicular to the contact surface.

[0138] [Note 14] A method for manufacturing footwear, comprising a footbed portion that supports the sole of the wearer's foot and has a contact surface, and a foot cover portion that covers the instep of the wearer's foot, The process by which the above footbed portion is manufactured, The process includes the manufacturing of the foot cover portion described above. The process for manufacturing the footbed portion and the process for manufacturing the foot cover portion include a process in which, using stereolithography, at least a portion of the footbed portion is sequentially additively manufactured from the ground surface side along a direction perpendicular to the ground surface, and then at least a portion of the foot cover portion is sequentially additively manufactured thereafter, thereby creating a single object. A method for manufacturing footwear, wherein, in the process of manufacturing the foot cover portion, a raised portion is provided on the outer surface of the foot cover portion which is defined by the molded object.

[0139] <Other forms, etc.> In the embodiments and their modifications described above, examples were given in which the raised portion on the outer surface of the foot cover portion was composed of linearly extending ridges or spot-shaped protrusions. However, the shape of the raised portion is not limited to these and can be changed in various ways. The number and layout of the raised portions can also be changed in various ways as needed.

[0140] Furthermore, in the embodiments and their variations described above, the foot cover portion that covers the instep of the wearer's foot was described as having a single strap-like or semi-dome-shaped form. However, it may also be configured to have multiple strap-like shapes arranged in the front-to-back direction, or to consist of a semi-dome-shaped portion positioned at the front and one or more strap-like portions positioned behind it. In such cases, it is not necessarily required that all of the divided foot cover portions have raised sections; it is sufficient that at least one of them has a raised section in an appropriate position.

[0141] Furthermore, in the embodiments and their modifications described above, only the sandal according to the 15th modification was used as an example to explain footwear in which the molded objects constituting part of the footbed and part of the foot cover have a three-dimensional lattice structure. However, the molded objects included in sandals or shoes according to other modifications and embodiments can also have a three-dimensional lattice structure.

[0142] Furthermore, while the embodiments and their modifications described above have been illustrated with examples of how the present invention can be applied to sandals and shoes, the present invention can naturally be applied to other types of footwear as well. Moreover, even when applying the present invention to shoes, it is not limited to shoes equipped with an upper body having the heat-shrinkable properties described above, but can be applied to shoes with various configurations.

[0143] Furthermore, the characteristic configurations disclosed in the embodiments described above and their variations can be combined with each other without departing from the spirit of the present invention.

[0144] Thus, the embodiments and their variations disclosed herein are illustrative in all respects and not restrictive. The technical scope of the present invention is defined by the claims and includes all modifications within the meaning and scope equivalent to the claims. [Explanation of symbols]

[0145] 1A, 1A1~1A16 Sandals, 1B Shoes, 2 Molded object, 2' Support part, 100A Sandal body, 100B Shell, 110 Footbed part, 111 Footbed area, 112 Contact surface, 120 Foot cover part, 121 Outer surface, 122 Inner surface, 123 Protrusion, 124 Projection, 125 Groove, 126 Opening, 130 Sole body, 140 Upper body, 150 Collar, 151 Front opening, 200 Liquid resin, 1000 Three-dimensional additive manufacturing device, 1001 Storage tank, 1002 Platform, 1003 Lifting mechanism, R1 Forefoot, R2 Midfoot, R3 Rearfoot.

Claims

1. A footbed portion that supports the sole of the wearer's foot and has a contact surface, It includes a foot cover that covers the instep of the wearer's foot, At least a portion of the footbed and at least a portion of the foot cover are made of a single molded object consisting of multiple cured layers formed by sequentially laminating and curing liquid resin when exposed to light of a specific wavelength. A raised portion is provided on the outer surface of the foot cover portion defined by the molded object, Footwear in which the raised portion is positioned to extend from the front end to the rear end of the foot cover portion.

2. The footbed portion has a footbed area on its upper surface that is capable of supporting the sole of the wearer's foot, The footwear according to claim 1, wherein, when L is defined as the distance from the front end position to the rear end position of the footbed area in the front-to-back direction that matches the length direction of the wearer's foot, and the range of the footwear is defined by dividing the footwear with a virtual plane perpendicular to the front-to-back direction, the raised portion is provided at a position within the range sandwiched between a virtual plane formed at a position 0.05 × L away from the front end position along the front-to-back direction and a virtual plane formed at a position 0.50 × L away from the front end position along the front-to-back direction.

3. The footwear according to claim 2, wherein the raised portion is provided at a position within the range enclosed by a virtual plane formed at a position 0.15 × L away from the front end position along the front-rear direction, and a virtual plane formed at a position 0.30 × L away from the front end position along the front-rear direction.

4. The footwear according to claim 1, wherein the protruding height of the raised portion is 3.0 mm or more and 10.0 mm or less.

5. The footwear according to claim 1, wherein the raised portion consists of a linearly extending ridge.

6. The footwear according to claim 5, wherein the aforementioned protrusions extend so as to intersect in the left-right direction that matches the width direction of the wearer's foot.

7. The footwear according to claim 6, wherein a groove is provided on the inner surface of the foot cover portion in the portion where the protruding portion is formed, extending along the direction in which the protruding portion extends.

8. The footwear according to claim 6, wherein the front end of the protruding portion is located on the inner side of the foot than the central portion in the left-right direction.

9. The footwear according to claim 8, wherein the protruding portion extends so as it moves from its front end to its rear end, it gradually moves away from the inner foot end of the foot cover portion.

10. The footwear according to claim 8, wherein the rear end of the protruding portion is located on the outer foot side of the central portion in the left-right direction.

11. The footwear according to claim 1, wherein the molded object has a three-dimensional lattice structure.

12. The footwear in question is a sandal, The footwear according to any one of claims 1 to 11, wherein the portion of the molded object that constitutes the foot cover portion has a strap shape connected to the inner foot end and the outer foot end of the portion of the molded object that constitutes the footbed portion.

13. The footwear in question is a shoe, The footwear according to any one of claims 1 to 11, wherein the portion of the molded object that constitutes the foot cover portion is made up of a part of the shoe upper portion that is connected to the entire circumference of the periphery of the portion of the molded object that constitutes the footbed portion when viewed in a direction perpendicular to the contact surface.

14. A method for manufacturing footwear, comprising a footbed portion that supports the sole of the wearer's foot and has a contact surface, and a foot cover portion that covers the instep of the wearer's foot, The process for manufacturing the footbed portion, The process includes the manufacturing of the foot cover portion, The process of manufacturing the footbed portion and the process of manufacturing the foot cover portion include a process in which a liquid resin is exposed to light of a specific wavelength, thereby forming at least a portion of the footbed portion by sequentially laminating and curing it in layers from the ground surface side along a direction perpendicular to the ground surface, and thereafter forming at least a portion of the foot cover portion by sequentially laminating and curing it in layers, thereby forming a single molded object. A method for manufacturing footwear, wherein, in the process of manufacturing the foot cover portion, a raised portion is provided on the outer surface of the foot cover portion that is defined by the molded object, extending from the front end to the rear end of the foot cover portion.

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