Shoe manufacturing method

Abstract

To provide a shoe manufacturing method and an auxiliary mold for manufacturing shoes that can be easily put on without using a shoehorn or the like and that can suppress foot fatigue. [Solution] The shoe includes an upper (12) that defines an interior space for the shoe and a reinforcing structure (14). The upper (12) has a heel section (20) and a heel guide section (22) that extends diagonally upward and rearward from the upper end (20a) of the heel section (20) and defines a guide surface that guides the user's heel into the interior space for the shoe. The reinforcing structure (14) has a plate-shaped first core (38) that is provided along the inner surface of the heel section (20) and a plate-shaped second core (40) that is provided independently of the first core (38) and along the guide surface of the heel guide section (22). When manufacturing the shoe, the first core (38) and second core (40) made of thermoplastic resin are attached to the upper (12), and then their shapes are deformed and maintained using a wooden mold (52) and auxiliary molds (54, 64). Next, the first core (38) and second core (40) are heated to soften them, and then cooled.

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing shoes that can be easily put on without using a shoehorn or the like. By law Regarding. [Background technology]

[0002] An example of a conventional shoe that can be easily put on without using a shoehorn or the like is disclosed in Patent Document 1 below. This shoe (shoe with a shoehorn function) has a heel section that covers the periphery of the heel of the foot and a heel guide section that extends diagonally upward and rearward from the upper end of the heel section. The heel section and heel guide section contain plate-shaped cores to reinforce them. The lower core contained in the heel section and the upper core contained in the heel guide section are integrally formed from synthetic resin.

[0003] The shoe disclosed in Patent Document 1 allows the heel of the user to slide along the heel guide, making it easy for the user to put on the shoe. However, because the lower core contained in the heel portion and the upper core contained in the heel guide are formed continuously and integrally, the upper part of the heel portion is hard, which causes the user's feet to tire easily when wearing the shoe.

[0004] In other words, when a user walks downhill, the ankle tilts backward, causing it to hit the hard part at the top of the heel, while when the user walks uphill, the foot slides downward in the shoe space, causing the ankle to hit the hard part at the top of the heel, resulting in the problem that the feet get tired easily in either case. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Utility Model Registration No. 3195071 Summary of the Invention

[0006] The present invention relates to a method for manufacturing shoes that can be easily put on without using a shoehorn or the like and that can reduce foot fatigue. The law The purpose is to provide.

[0007] In order to achieve the above object, the method of manufacturing a shoe according to the present invention is characterized by comprising: a heel portion formed to be curved to fit the heel of a user; The shoes the upper has a heel guide portion that forms a guide surface that guides the shoe into the internal space; a core attachment process that attaches a plate-shaped first core material made of thermoplastic resin to the inner surface of the heel portion and attaches a plate-shaped second core material made of thermoplastic resin to the guide surface of the heel guide portion; a last attachment process that attaches a wooden mold to the upper to which the first core material and the second core material are attached and aligns the heel portion and the first core material to the wooden mold; an auxiliary mold attachment process that inserts a first auxiliary mold between the wooden mold and the heel guide portion and aligns the heel guide portion and the second core material to the first auxiliary mold; a heating process that heats and softens the first core material and the second core material whose shapes are maintained by the wooden mold and the first auxiliary mold; and a cooling process that cools and hardens the first core material and the second core material softened in the heating process while their shapes are maintained by the wooden mold and the first auxiliary mold.

[0008] In this shoe manufacturing method, the first core and the second core are softened in a heating process and can be deformed to a shape that fits the wooden last and the first auxiliary mold. Therefore, there is no need to pre-form the first core and the second core into a special shape according to the shoe specifications, which reduces manufacturing costs. Furthermore, because the first core and the second core are independent of each other, the first core can be shared even when manufacturing other shoes with different heel guide shapes, thereby reducing manufacturing costs.

[0009] Another feature of the shoe manufacturing method according to the present invention is that in the core attachment step, the first core and the second core are arranged so as not to overlap each other.

[0010] In this shoe manufacturing method, the first core and the second core do not overlap each other, so the upper part of the heel does not become hard, and the user's feet do not get tired easily when wearing the shoes.

[0011] Another feature of the shoe manufacturing method according to the present invention is that it includes a core preparing step of preparing the first core and the second core by cutting them out from a single thermoplastic resin sheet.

[0012] This shoe manufacturing method reduces manufacturing costs because the first core and second core are cut from a common thermoplastic resin sheet. Although the first core attached to the inner surface of the heel and the second core attached to the upper surface of the heel guide are different sizes, the first core and second core can be cut without waste by appropriately determining the cutting patterns for the first core and second core in the thermoplastic resin sheet.

[0013] Another feature of the shoe manufacturing method according to the present invention is that the core attaching step includes a step of adhering the second core to the guide surface with a hot melt adhesive.

[0014] In this shoe manufacturing method, the second core can be temporarily fixed to the guide surface of the heel guide with hot melt adhesive, preventing the second core from shifting position during subsequent auxiliary mold attachment processes, etc. Furthermore, the hot melt adhesive melts and spreads over a wide area during the heating process, ensuring reliable bonding of the second core to the heel guide and reinforcing the second core.

[0015] Another feature of the shoe manufacturing method of the present invention is that the upper has a sheet-like tongue portion that covers the instep of the user's foot, the core attachment process includes a process of attaching a plate-like third core portion formed of a thermoplastic resin to the underside of the tongue portion, the auxiliary mold attachment process includes a process of inserting a second auxiliary mold between the wooden last and the tongue portion and aligning the tongue portion and the third core portion with the second auxiliary mold, the heating process includes a process of heating and softening the third core portion whose shape is maintained by the wooden last and the second auxiliary mold, and the cooling process includes a process of cooling and hardening the third core portion softened in the heating process while its shape is maintained by the wooden last and the second auxiliary mold.

[0016] In this shoe manufacturing method, the third core is softened in the heating process and can be deformed to a shape that fits the second auxiliary mold. Therefore, there is no need to pre-form the third core into a special shape according to the shoe specifications, which reduces manufacturing costs. [Brief explanation of the drawings]

[0021] [Figure 1] FIG. 1 is a perspective view showing the configuration of a shoe. [Figure 2] 1A and 1B are diagrams showing the configuration of a shoe, in which (A) is a plan view and (B) is a front view. [Figure 3] (A-1) is a front view showing the configuration of the first core material before suturing, (A-2) is a front view showing the configuration of the first core material after suturing, (B) is a front view showing the configuration of the second core material, and (C) is a front view showing the configuration of the third core material. [Figure 4] FIG. 2 is a front view showing a cutting pattern for a core material defined in a single thermoplastic resin sheet. [Figure 5] FIG. 2 is a flow chart showing a method for manufacturing shoes according to an embodiment. [Figure 6] (A) is a front view showing the bag body, (B) is a front view showing the state where the wooden mold is attached to the upper, and (C) is a front view showing the state where the first auxiliary mold is inserted between the wooden mold and the heel guide part, and the second auxiliary mold is inserted between the wooden mold and the tongue part. [Figure 7]1A to 1C are diagrams showing the configuration of a first auxiliary mold, in which (A) is a perspective view, (B) is a front view, and (C) is a right side view. [Figure 8] 10A, 10B, and 10C are diagrams showing the configuration of a second auxiliary mold, in which (A) is a perspective view, (B) is a front view, and (C) is a left side view. [Figure 9] FIG. 2 is a front view showing the configuration of a heating device for performing a heating step. DETAILED DESCRIPTION OF THE INVENTION

[0022] Hereinafter, a method for manufacturing shoes according to an embodiment of the present invention will be described. By law This will be described with reference to the drawings.

[0023] (Shoe configuration) FIG. 1 is a perspective view showing the configuration of shoe 10. FIG. 2 shows the configuration of shoe 10, with FIG. 2(A) being a plan view and FIG. 2(B) being a front view. FIG. 3(A-1) is a front view showing the configuration of first core 38 before sewing, FIG. 3(A-2) is a front view showing the configuration of first core 38 after sewing, FIG. 3(B) is a front view showing the configuration of second core 40, and FIG. 3(C) is a front view showing the configuration of third core 42. FIG. 4 is a front view showing the cutout pattern of the core set in a single thermoplastic resin sheet 46.

[0024] The shoe 10 shown in Fig. 1 includes an upper 12 that defines an interior space S, a reinforcing structure 14 that reinforces the upper 12, a lining 16 that covers the inside surface of the upper 12, and a sole 18. Note that the shoe 10 shown in Fig. 1 is a lace-up shoe, but the laces are omitted from the drawing.

[0025] 2(A), the upper 12 has a heel portion 20 curved to fit the user's heel, a heel guide portion 22 forming a guide surface 22a that guides the user's heel into the shoe interior space S, a medial portion 24 that covers the medial side of the user's foot, a lateral portion 26 that covers the lateral side of the user's foot, a toe portion 28 that covers the user's toes, and a tongue portion 30 that covers the user's instep. Note that because the guide surface 22a is covered with the lining 16, when the user puts on the shoe 10, the user's heel comes into contact with the guide surface 22a via the lining 16.

[0026] The upper 12 shown in Figures 2(A) and (B) is constructed by sewing together a plurality of sheet-like components such as leather. As shown in Figure 2(A), the center of the upper 12 is formed with an opening 32 for inserting the user's foot into the shoe interior space S, and a cutout 34 continuous with the opening 32. A plurality of lace holes 36 for threading shoelaces (not shown) are formed on both the left and right sides of the cutout 34 in the center of the upper 12.

[0027] As shown in Figure 2(A), heel portion 20 is curved so that it bulges backward in a U-shape when viewed from above, and heel guide portion 22 extends obliquely upward and backward from upper end 20a (Figure 2(B)) of heel portion 20 and is curved so that it bulges backward in a U-shape. The sheet-like components that make up heel portion 20 and heel guide portion 22 are prepared independently and sewn together.

[0028] Since heel guide 22 extends obliquely upward and rearward, the upper edge of heel guide 22 is also the rear edge, and the lower edge of heel guide 22 is also the front edge. Furthermore, since heel guide 22 is curved to bulge in a U-shape, guide surface 22a is also the inner surface of heel guide 22.

[0029] The inclination angle θ of the center portion of the heel guide 22 (guide surface 22a) in the left-right direction relative to the vertical line L shown in Figure 2(B) is set to 15 degrees. Note that this inclination angle θ is not limited to 15 degrees and can be changed appropriately taking into consideration the ease of heel slippage, etc., but it is desirable for it to be within the range of 10 to 45 degrees.

[0030] 2(A) and (B) is formed in a rectangular shape (not shown) so as to close the cutout 34. In other words, the tongue 30 is made of a rectangular sheet-like part. One end in the length direction of the tongue 30, i.e., the front end, is sewn to the toe portion 28 of the upper 12.

[0031] As shown in FIG. 2(B), the tongue portion 30 is inclined so that its rear end is higher than its front end. The tongue portion 30 is also curved so that its central portion in the left-right direction bulges upward in a U-shape. At least a region of the tongue portion 30 extending 10 to 15 mm from its rear end is inclined obliquely upward and rearward. Therefore, when a user puts on the shoe 10, the user's toes are less likely to get caught on the rear end of the tongue portion 30.

[0032] The material of the upper 12 is not particularly limited, but it is desirable that it has the property of softening when heated and hardening when cooled, and specifically, natural leather or thermoplastic synthetic leather is desirable.

[0033] The reinforcing structure 14 shown in Figure 1 has a plate-shaped first core material 38 provided between the heel portion 20 and the lining 16 along the inner surface of the heel portion 20, a plate-shaped second core material 40 provided between the heel guide portion 22 and the lining 16 along the guide surface 22a of the heel guide portion 22, and a plate-shaped third core material 42 provided between the tongue portion 30 and the lining 16 along the underside of the rear end portion of the tongue portion 30.

[0034] The first core 38 is a so-called "moon-shaped core" and is curved to bulge backward in a U-shape in a plan view so as to fit along the inner surface of the heel portion 20. The second core 40 is curved to bulge obliquely downward and backward in a U-shape so as to fit along the guide surface 22a of the heel guide 22. The third core 42 is curved so that its left-right central portion bulges upward in a U-shape so as to fit along the underside of the rear end of the tongue portion 30, at least in a region 10 to 15 mm from the rear end.

[0035] The first core 38, second core 40, and third core 42 are cut into flat plates from a thermoplastic resin sheet 46 shown in Fig. 4, heated and deformed in a heating step S7 (Fig. 5) described below, and then cooled in a cooling step S9 (Fig. 5) to set their shapes. Therefore, the heel section 20, heel guide section 22, and tongue section 30 shown in Fig. 1 are not only reinforced by the first core 38, second core 40, and third core 42, but also retain their shapes.

[0036] As shown in Figure 3 (A-1), the flat first core 38 is formed to cover almost the entire heel portion 20 (Figure 1). That is, the upper edge 38a of the first core 38 is curved so as to descend from the center in the left-right direction toward both ends, along the upper edge of the heel portion 20. The lower edge 38b of the first core 38 is linearly formed so as to gradually ascend from the center in the left-right direction toward both ends, along the lower edge of the heel portion 20. An inverted V-shaped notch 38c is formed in the lower part of the center in the left-right direction of the first core 38.

[0037] As shown in Figure 3 (A-2), the left and right portions of the first core 38 that face each other across the cutout 38c are sewn together with thread 44, thereby giving the first core 38 a three-dimensional shape with a bulging central portion. Therefore, in the core attachment step S1c (Figure 5) described below, the entire first core 38 can be easily fitted along the inner surface of the heel portion 20.

[0038] The upper, left, and right ends (portions outside the dashed dotted line) of the first core 38 are formed so that their thickness gradually decreases toward these edges. Therefore, in the core attachment step S1c (FIG. 5) described below, it is particularly easy to align the thin upper, left, and right ends of the first core 38 with the inner surface of the heel portion 20.

[0039] As shown in Figure 3(B), the flat second core 40 is formed to correspond to almost the entire heel guide 22 (Figure 1). In other words, the upper edge (rear edge) 40a of the second core 40 is curved so as to descend from the center toward both ends in the left-right direction, so as to follow the upper edge (rear edge) of the heel guide 22. The lower edge (front edge) 40b of the second core 40 is linearly formed so as to descend gradually from the center toward both ends in the left-right direction, so as to follow the lower edge (front edge) of the heel guide 22.

[0040] The upper, left, and right ends (portions outside the dashed lines) of second core material 40 are formed so that their thickness gradually decreases toward these edges. Therefore, in the core material attachment step S1c (FIG. 5) described below, it is particularly easy to align the thin upper, left, and right ends of second core material 40 with guide surface 22a.

[0041] 3(C), the flat third core material 42 is formed in a rectangular shape so as to cover almost the entire left-right area of ​​the rear end of the tongue section 30 (FIG. 1). In other words, the length of the third core material 42 in the left-right direction (longitudinal direction) is set to be slightly shorter than the length of the rear end of the tongue section 30 in the left-right direction, and the length of the third core material 42 in the front-rear direction (transverse direction) is set to be sufficiently shorter than the length in the left-right direction.

[0042] The first core 38 shown in Fig. 3(A-1), the second core 40 shown in Fig. 3(B), and the third core 42 shown in Fig. 3(C) are formed by cutting a thermoplastic resin sheet 46 shown in Fig. 4, and are adhered to the corresponding portions of the upper 12 (Fig. 1) using a hot melt adhesive. The type of thermoplastic resin sheet 46 is not particularly limited, but the shoe 10 uses a sheet in which polyester nonwoven fabric is impregnated with styrene butadiene (SBR latex).

[0043] (Method of manufacturing shoes according to the embodiment) FIG. 5 is a flow diagram showing a shoe manufacturing method according to an embodiment. FIG. 6(A) is a front view of the pouch 48, FIG. 6(B) is a front view showing the state in which the wooden last 52 is attached to the upper 12, and FIG. 6(C) is a front view showing the state in which the first auxiliary mold 54 is inserted between the wooden last 52 and the heel guide 22 and the second auxiliary mold 64 is inserted between the wooden last 52 and the tongue 30. FIG. 7 shows the configuration of the first auxiliary mold 54, with FIG. 7(A) being a perspective view, FIG. 7(B) being a front view, and FIG. 7(C) being a right side view. FIG. 8 shows the configuration of the second auxiliary mold 64, with FIG. 8(A) being a perspective view, FIG. 8(B) being a front view, and FIG. 8(C) being a left side view. FIG. 9 is a front view showing the configuration of a heating device 74 for performing the heating step S7.

[0044] In the shoe manufacturing method, the manufacturer performs the bag body manufacturing step S1, the last attachment step S3, the auxiliary mold attachment step S5, the heating step S7, the cooling step S9, and the sole attachment step S11 in this order, as shown in Figure 5. In other words, the shoe manufacturing method includes the bag body manufacturing step S1, the last attachment step S3, the auxiliary mold attachment step S5, the heating step S7, the cooling step S9, and the sole attachment step S11.

[0045] The pouch manufacturing process S1 shown in Fig. 5 is a process for manufacturing a pouch 48 shown in Fig. 6(A). The pouch 48 is the portion of the shoe 10 shown in Fig. 1 excluding the sole 18, and is configured in a pouch shape by sewing a flexible false sole 50 to the bottom of the upper 12.

[0046] 5, in the bag manufacturing process S1, the manufacturer performs an upper preparing step S1a, a core preparing step S1b, a core attaching step S1c, a lining attaching step S1d, and a temporary bottom attaching step S1e in this order. In other words, the bag manufacturing process S1 includes an upper preparing step S1a, a core preparing step S1b, a core attaching step S1c, a lining attaching step S1d, and a temporary bottom attaching step S1e.

[0047] In the upper preparation step S1a shown in Fig. 5, the manufacturer prepares the upper 12 of the bag body 48 shown in Fig. 6(A) by sewing together a plurality of sheet-like components such as leather. As described above, the upper 12 has the heel portion 20 curved to fit the heel of the user, and the heel guide portion 22 extending obliquely upward and rearward from the upper end 20a of the heel portion 20 and constituting the guide surface 22a that guides the heel of the user into the in-shoe space S.

[0048] In the core material preparation step S1b shown in FIG. 5, the manufacturer prepares a first core material 38 shown in FIG. 3(A-2), a second core material 40 shown in FIG. 3(B), and a third core material 42 shown in FIG. 3(C). That is, the manufacturer sets cutting patterns for the first core material 38, the second core material 40, and the third core material 42 on a single thermoplastic resin sheet 46 shown in FIG. 4 without waste, and cuts out the first core material 38, the second core material 40, and the third core material 42 according to these patterns. Furthermore, as shown in FIG. 3(A-2), the first core material 38 is finished into a three-dimensional shape by closing the cutouts 38c of the first core material 38 with thread 44.

[0049] In the core attachment step S1c shown in Figure 5, the manufacturer attaches the first core 38 to the inner surface of the heel portion 20 and the second core 40 to the guide surface 22a of the heel guide portion 22. The manufacturer also attaches the third core 42 to the underside of the rear end of the tongue portion 30. As described above, the first core 38, the second core 40, and the third core 42 are made of thermoplastic resin and are flexible plates. This allows the manufacturer to easily align them with the inner surface of the heel portion 20, the guide surface 22a, and the underside of the rear end of the tongue portion 30.

[0050] The specific means for attaching the first core 38, the second core 40, and the third core 42 to the upper 12 is bonding using a hot melt adhesive. That is, the core attachment step S1c includes the steps of bonding the first core 38 to the inner surface of the heel portion 20 with a hot melt adhesive, bonding the second core 40 to the guide surface 22a with a hot melt adhesive, and bonding the third core 42 to the underside of the rear end of the tongue portion 30 with a hot melt adhesive. Note that this bonding is for temporary fixation; permanent fixation will be performed in the subsequent heating step S7 and cooling step S9.

[0051] In the lining attachment step S1d shown in FIG. 5, the manufacturer sews the lining 16 (FIG. 1) onto the inner surface of the upper 12 shown in FIG. 6(A).

[0052] In the temporary sole attachment step S1e shown in Fig. 5, the manufacturer sews a flexible cloth-like or sheet-like temporary sole 50 to the bottom of the upper 12 shown in Fig. 6(A). The temporary sole 50 is to be heated in the subsequent heating step S7, so it must have heat resistance at least as great as that of the upper 12.

[0053] 5, the manufacturer attaches a last 52 shown in FIG. 6(B) to the upper 12 to which the first core 38, the second core 40, and the third core 42 have been attached. As a result, the upper 12 and the first core 38 are deformed to fit the last 52, and this shape is maintained by the last 52.

[0054] 5, the manufacturer attaches the first auxiliary mold 54 shown in FIG. 6(C) to the rear of the upper end of the wooden mold 52, i.e., the first mounting portion 52a, and inserts the first auxiliary mold 54 between the wooden mold 52 and the heel guide 22. This causes the heel guide 22 and the second core 40 to deform to fit the first auxiliary mold 54, and this shape is maintained by the first auxiliary mold 54.

[0055] 7(A), (B), and (C), the first auxiliary mold 54 includes a rectangular plate-shaped left wall 56 covering the left surface of the first attachment portion 52a shown in Fig. 6(C), a rectangular plate-shaped right wall 58 covering the right surface of the first attachment portion 52a, a rear wall 60 covering the rear surface of the first attachment portion 52a, and an upper wall 62 covering the upper surface of the first attachment portion 52a. A front surface 60a of the rear wall 60 shown in Fig. 7(C) is formed to fit along the rear surface of the first attachment portion 52a, and a rear surface 60b of the rear wall 60 shown in Fig. 7(B) is formed at an angle relative to the front surface 60a so as to fit along the guide surface 22a of the heel guide portion 22.

[0056] The left wall 56, right wall 58, rear wall 60, and top wall 62 are integrally formed from synthetic resin to be flexible. The left wall 56, right wall 58, and rear wall 60 are all formed so that their cross-sectional shape is U-shaped and opens forward, and the top wall 62 is also U-shaped and opens forward in a plan view. Therefore, the first auxiliary mold 54 can elastically open left and right, and when the first auxiliary mold 54 is attached to the first attachment portion 52a, the first auxiliary mold 54 is unlikely to come off the first attachment portion 52a.

[0057] The lower end portions of the left wall 56, the right wall 58, and the rear wall 60 are formed so that their thickness gradually decreases toward the lower edge. This makes it possible to reduce the steps that occur between the outer surface of the wooden mold 52 and the outer surfaces of the left wall 56, the right wall 58, and the rear wall 60, thereby enhancing the sense of unity between the wooden mold 52 and the first auxiliary mold 54.

[0058] 5, the manufacturer attaches the second auxiliary mold 64 shown in FIG. 6(C) to the inclined portion of the wooden mold 52, i.e., the second attachment portion 52b, and inserts the second auxiliary mold 64 between the wooden mold 52 and the tongue portion 30. Then, the tongue portion 30 and the third core material 42 are deformed to fit the second auxiliary mold 64, and the shape is maintained by the second auxiliary mold 64.

[0059] As shown in Figures 8(A), (B), and (C), the second auxiliary mold 64 includes a triangular plate-shaped left wall 66 that covers the left surface of the second attachment portion 52b shown in Figure 6(C), a triangular plate-shaped right wall 68 that covers the right surface of the second attachment portion 52b, and an upper wall 70 that covers the upper surface of the second attachment portion 52b. The left wall 66, right wall 68, and upper wall 70 are integrally formed from synthetic resin to be flexible. The lower edges of the left wall 66 and right wall 68 are curved so as to bulge downward when viewed from the front (Figure 8(B)).

[0060] The lower surface 70a of the upper wall 70 shown in Fig. 8(C) is formed to fit along the upper surface of the second mounting portion 52b. The upper surface 70b of the upper wall 70 shown in Fig. 8(B) is inclined relative to the lower surface 70a so as to fit along the lower surface of the tongue portion 30, and is formed to be gently curved so as to bulge downward.

[0061] In the auxiliary mold attachment step S5, it is not necessary to align the entire upper surface 70b of the upper wall 70 with the lower surface of the tongue portion 30, and the upper surface 70b may be aligned only with a portion of the tongue portion 30 whose shape is to be maintained. In this embodiment, the upper surface 70b is aligned with at least an area of ​​the tongue portion 30 that is 10 to 15 mm from the rear end. The position of the second auxiliary mold 64 relative to the tongue portion 30 is fixed with a fixing member 72 (FIG. 9) such as an annular rubber material.

[0062] In the heating step S7 shown in Fig. 5, the manufacturer uses a heating device 74 shown in Fig. 9 to heat the bag body 48, thereby heating the first core 38, the second core 40, and the third core 42 incorporated in the bag body 48. As shown in Fig. 9, the heating device 74 includes a device main body 76 that forms a heating chamber Q, a heater 78 for heating that is disposed in the heating chamber Q, and a control unit 80 that controls the heating temperature and driving time (i.e., heating time) of the heater 78.

[0063] When the bag body 48 is heated by the heating device 74, the first core 38, whose shape is maintained by the wooden mold 52, softens and adheres to the inner surface of the heel portion 20, and the hot melt adhesive is melted by the heat, thereby bonding the first core 38 to the heel portion 20. The second core 40, whose shape is maintained by the first auxiliary mold 54, softens and adheres to the guide surface 22a of the heel guide 22, and the hot melt adhesive is melted by the heat, thereby bonding the second core 40 to the heel guide 22. The third core 42, whose shape is maintained by the second auxiliary mold 64, softens and adheres to the underside of the rear end of the tongue portion 30, and the hot melt adhesive is melted by the heat, thereby bonding the third core 42 to the tongue portion 30. The heating temperature and driving time of the heater 78 are not particularly limited, but in this embodiment, the heating temperature is set within the range of 120 to 140°C, and the driving time is set within the range of 30 to 40 minutes.

[0064] 5, the manufacturer cools and hardens the first core material 38, the second core material 40, and the third core material 42 that were heated and softened in the heating step S7. Note that no special cooling device is required to cool the first core material 38, the second core material 40, and the third core material 42; they can be cooled naturally in the factory environment.

[0065] In the sole attachment step S11 shown in FIG. 5, the manufacturer adheres and sews the sole 18 to the bottom of the upper 12.

[0066] (Effects of the embodiment) The shoe 10 manufactured by the shoe manufacturing method of the embodiment can achieve the following effects due to the above configuration. That is, as shown in Figure 1, the heel portion 20 is reinforced by the first core 38, and the heel guide portion 22 is reinforced by the second core 40. Therefore, even when the heel guide portion 22 is stepped on by the user's foot, the heel portion 20 and the heel guide portion 22 are less likely to deform. Therefore, the user can easily put on the shoe without using a shoehorn or the like.

[0067] As shown in Figure 2(B), the second core 40 is provided independently of the first core 38, so flexibility of the upper 12 can be ensured between the first core 38 and the second core 40. In other words, flexibility can be ensured in the upper part of the heel portion 20. Therefore, when going uphill or downhill, the user's foot can be prevented from hitting the upper part of the heel portion 20 hard, and fatigue in the user's foot can be reduced.

[0068] The heel guide portion 22 and the second core material 40 are formed to be curved so as to bulge in a U-shape diagonally downward and rearward, so that even when the rear end portion of the heel guide portion 22 is stepped on by the user's foot, the heel guide portion 22 and the second core material 40 are unlikely to bend, and the user can easily put on the shoes without using a shoehorn or the like.

[0069] As shown in FIG. 3(A-2), the upper end of the first core 38 is formed so that its thickness gradually decreases toward the upper edge 38a, thereby preventing a step from occurring between the inner surface of the heel portion 20 (FIG. 1) and the inner surface of the upper end of the first core 38. Furthermore, as shown in FIG. 3(B), the upper end (rear end) of the second core 40 is formed so that its thickness gradually decreases toward the upper edge (rear edge) 40a, thereby preventing a step from occurring between the guide surface 22a and the inner surface of the second core 40. Therefore, the heel of the user will not get caught on these steps, allowing the user to wear the shoe 10 without any discomfort.

[0070] 1, the tongue 30 and the third core 42 are curved so that their left-right central portions bulge upward, making the tongue 30 less likely to deform even when pressed with the toes, allowing the user to easily put on the shoe 10 without using their hands. Furthermore, at least the regions of the tongue 30 and the third core 42 extending 10 to 15 mm from their rear ends are formed with a large upward and rearward inclination, which, combined with the curved shape, makes it less likely that the user's toes will get caught on the rear end of the tongue 30 when putting on the shoe 10.

[0071] The shoe manufacturing method of this embodiment has the following advantages due to the above configuration: The first core 38, the second core 40, and the third core 42 are softened in the heating step S7 (FIG. 5) and can be deformed to a shape that fits the wooden last 52, the first auxiliary mold 54, and the second auxiliary mold 64, eliminating the need to pre-form these into a special shape according to the specifications of the shoe 10, thereby reducing the manufacturing cost of the shoe 10. Furthermore, because the first core 38, the second core 40, and the third core 42 are independent of one another, the first core 38 can be commonly used even when manufacturing other shoes 10 having different shapes of heel guide 22 or tongue 30, thereby reducing the manufacturing cost of the shoe 10.

[0072] 5, the manufacturing cost can be reduced because the first core material 38, the second core material 40, and the third core material 42 are cut from a common thermoplastic resin sheet 46. Furthermore, although the first core material 38, the second core material 40, and the third core material 42 are different sizes, by appropriately determining the cutting pattern in the thermoplastic resin sheet 46, these can be cut out without waste.

[0073] 5, the first core 38, second core 40, and third core 42 are temporarily fixed with hot melt adhesive to the inner surface of the heel section 20, the guide surface 22a of the heel guide section 22, and the underside of the rear end of the tongue section 30, preventing these from shifting position in the subsequent auxiliary mold attachment step S5, etc. Furthermore, because the hot melt adhesive melts and spreads over a wide area in the heating step S7, a high adhesive effect can be obtained while minimizing the amount of adhesive used.

[0074] In the auxiliary mold attachment step S5 shown in Figure 5, the first auxiliary mold 54 can be easily attached to the wooden mold 52 by simply placing the entire left wall 56, right wall 58, rear wall 60, and upper wall 62 of the first auxiliary mold 54 (Figure 7) over the first attachment portion 52a of the wooden mold 52 (Figure 6(C)). In addition, by preparing multiple first auxiliary molds 54 with different inclination angles and shapes of the front surface 60a and rear surface 60b of the rear wall 60 (Figure 7(B)), it is possible to accommodate multiple heel guide portions 22 with different inclination angles θ (Figure 2(B)) and shapes.

[0075] (Variation) It should be noted that the present invention is not limited to the above-described embodiment, and various modifications are possible without departing from the scope of the present invention. That is, in the above-described shoe 10, the cutout portion 34 formed in the upper portion of the upper 12 shown in Fig. 2(A) is closed by a shoelace (not shown), but the cutout portion 34 may also be closed by a rubber belt or the like.

[0076] In the above-described shoe 10, the upper, left, and right ends (portions outside the dashed dotted line) of the first core 38 shown in FIG. 3(A-2) are formed so that their thickness gradually decreases toward these edges, but in addition, the lower end of the first core 38 may be formed so that its thickness gradually decreases toward the lower edge 38b. Alternatively, only the upper end of the first core 38 may be formed so that its thickness gradually decreases toward the upper edge 38a. In other words, at least the upper end of the first core 38 may be formed so that its thickness gradually decreases toward the upper edge 38a.

[0077] In the above-described shoe 10, the upper, left, and right ends (portions outside the dashed dotted line) of the second core 40 shown in FIG. 3(B) are formed so that their thickness gradually decreases toward these edges, but in addition, the lower end of the second core 40 may be formed so that its thickness gradually decreases toward the lower edge 40b. Alternatively, only the upper end of the second core 40 may be formed so that its thickness gradually decreases toward the upper edge 40a. In other words, at least the upper end of the second core 40 may be formed so that its thickness gradually decreases toward the upper edge 40a.

[0078] In the shoe manufacturing method of the above embodiment, in the core attachment step S1c shown in Figure 5, the first core 38, the second core 40, and the third core 42 are temporarily fixed to the corresponding parts of the upper 12 with hot melt adhesive, but instead of hot melt adhesive, other adhesives or double-sided adhesive tape may be used for temporary fixing.

[0079] In the shoe manufacturing method of the above embodiment, the lining attachment step S1d is performed after the core attachment step S1c shown in Fig. 5, but the core attachment step S1c may be performed after the lining attachment step S1d. In this case, in the core attachment step S1c, the first core 38, the second core 40, and the third core 42 may be inserted through insertion openings provided between the upper 12 and the lining 16, and then bonded to the corresponding parts of the upper 12 with a hot melt adhesive.

[0080] In the shoe manufacturing method of the above embodiment, the last attachment step S3 is performed after the temporary sole attachment step S1e shown in Figure 5, but if a method of hanging the upper 12 on the last 52 is adopted in the last attachment step S3, the temporary sole attachment step S1e may be omitted.

[0081] In the shoe manufacturing method of the above embodiment, the sole attachment step S11 is performed after the heating step S7 and the cooling step S9 shown in Figure 5, but if the sole 18 shown in Figure 1 has heat resistance at least as good as that of the upper 12, the sole attachment step S11 may be performed before the heating step S7 and the cooling step S9. [Explanation of symbols]

[0082] L...vertical line, Q...heating chamber, S...inner space of shoe, 10...shoe, 12...upper, 14...reinforcement structure, 16...lining, 18...sole, 20...heel portion, 20a...upper end, 22...heel guide portion, 22a...guide surface, 24...medial portion, 26...lateral portion, 28...toe portion, 30...tongue portion, 32...opening, 34...cutout portion, 36...lace holes, 38...first core material, 38a...upper edge, 38b...lower edge, 38c...cutout, 40...second core material, 40a...upper edge, 40b...lower edge, 4 2...third core material, 44...thread, 46...thermoplastic resin sheet, 48...bag body, 50...false bottom, 52...wooden mold, 52a...first attachment part, 52b...second attachment part, 54...first auxiliary mold, 56...left wall, 58...right wall, 60...rear wall, 60a...front surface, 60b...rear surface, 62...top wall, 64...second auxiliary mold, 66...left wall, 68...right wall, 70...top wall, 70a...bottom surface, 70b...top surface, 72...fixing member, 74...heating device, 76...device main body, 78...heater, 80...control unit.

Claims

1. an upper preparation process for preparing an upper having a heel portion curved to fit the heel of a user, and a heel guide portion extending obliquely upward and rearward from the upper end of the heel portion to form a guide surface for guiding the heel of the user into a shoe interior space; a core attachment step of attaching a plate-shaped first core made of a thermoplastic resin to the inner surface of the heel portion and attaching a plate-shaped second core made of a thermoplastic resin to the guide surface of the heel guide portion; a last-fitting step of fitting a last to the upper to which the first core and the second core are attached and aligning the heel portion and the first core with the last; an auxiliary mold attachment step of inserting a first auxiliary mold between the wooden mold and the heel guide portion and aligning the heel guide portion and the second core material with the first auxiliary mold; a heating step of heating and softening the first core material and the second core material whose shapes are maintained by the wooden mold and the first auxiliary mold; a cooling step of cooling and hardening the first core material and the second core material softened in the heating step while their shapes are maintained by the wooden mold and the first auxiliary mold.

2. The shoe manufacturing method according to claim 1 , wherein in the core attachment step, the first core and the second core are arranged so as not to overlap each other.

3. The shoe manufacturing method according to claim 1 , further comprising a core preparing step of preparing the first core and the second core by cutting them from a single thermoplastic resin sheet.

4. The shoe manufacturing method according to claim 1 , wherein the core attaching step includes a step of adhering the second core to the guide surface with a hot melt adhesive.

5. The upper has a sheet-like tongue portion that covers the instep of the user's foot, the core material attaching step includes a step of attaching a plate-shaped third core material formed of a thermoplastic resin to a lower surface of the tongue portion, The auxiliary mold attaching step includes a step of inserting a second auxiliary mold between the wooden mold and the tongue portion and aligning the tongue portion and the third core material with the second auxiliary mold, the heating step includes a step of heating and softening the third core material whose shape is maintained by the wooden mold and the second auxiliary mold, 4. The shoe manufacturing method according to claim 1, wherein the cooling step includes a step of cooling and hardening the third core material softened in the heating step while the shape of the third core material is maintained by the wooden mold and the second auxiliary mold.

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