JPH11138660A - Manufacture of shoe and last used for the method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a shoe without generating a flash due to flow-out of a foam polyurethane or the like for molding an outer sole from a gap of steps of an upper superposing parts. SOLUTION: In the method for manufacturing a shoe comprising the step of injection molding an outer sole material 8 in the state where an upper portion 4 and a back material 7 are sandwiched between a last 9 and the side lip 11 of a side mold, an elastic member 14 is disposed at a position corresponding to the lip 11 of the last 9 side and corresponding to a superposed part of the upper portion 4 so that a thickness of the superposed part of the portion 4 can be absorbed by the member 14 at the time of clamping the mold.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing shoes in which the outsole is produced by injection molding of foamed polyurethane or the like, and a last used in the method. Foam for molding the outsole by providing an elastic member on the lower edge of the last (foot) side inserted into the shoe corresponding to the edge of the side mold upper end side lip for molding the outsole side of the shoe The present invention relates to a shoe manufacturing method in which polyurethane and the like do not flow out of a gap between an upper-overlap portion and generate burrs, and a last used in the method.

[0002]

2. Description of the Related Art FIGS.
Referring to FIG. 6, FIG. 6 is a perspective view of a completed shoe, and FIG. 7 is a main part corresponding to a part A in FIG. 6 showing an arrangement of side molds and a last when the shoe is manufactured. FIG. 8 is a perspective view of the side mold, and FIG.
FIG. 3B is a sectional view showing the safety shoe.

In the figure, 1 is a shoe body, 2 is an outsole, 3 is an upper end of a rising outsole, 4a is a toe upper, 4b is a waist upper, 4c is a heel upper, 5 is a toe upper-4a. And a waist-side upper 4b. This shoe basically has an outer sole in a gap defined by an insole 8, an upper 4, a side mold 10, and a bottom mold 12, as shown in FIG. 2 is manufactured by injection molding of the foamed polyurethane 20.

[0004] Specifically, as shown in FIG.
a, 4b and the backing material 7, the last 9 and the side mold 1
Outsole 2
Injection molding of the polyurethane foam 20 forming
At the time of injection molding, particularly, a small gap S caused by the stepped portion 5a generated at the overlapping portion of the toe side upper 4a and the waist upper 4b, that is, a gap S corresponding to the thickness of the waist upper 4b (FIG. 7) 6), the foamed polyurethane material of the outsole 2 flows out by the injection pressure, and FIG.
Burrs 6 as shown in FIG. 7 are generated. The thickness of the side lip 11 is generally about 2.5 mm.

Therefore, in order to prevent the occurrence of such burrs 6, as shown in FIG. 9, the upper portions corresponding to the overlapping portions are formed in advance in a tapered shape, and the generation of the gap S is minimized. (Although the thickness is slightly different depending on the thickness of the upper material, for example, the allowable range of the thickness of the overlapping portion is 1.8 + -0.3 mm.)
Need to be about). However, it is difficult to completely eliminate the gap S, and it is practically impossible to prevent generation of burrs.

Further, in order to prevent burrs from being formed in the gap S of the step formed in the overlapping portion 5 of the upper material, the side mold 10 is tightened toward the last 9 with a strong force. . However, the material of the last 9
Since a rigid body such as aluminum or resin is usually used, when the side mold 10 is tightly tightened, as a result, the edge of the side lip 11 at the upper end of the side mold 10 shown in FIG. There was a danger of being cut off. Further, as shown in FIG. 10, there is a possibility that a fastening mark 13 of the side lip is generated, resulting in a defective product.

Further, the upper-member overlapping portion may extend to several places depending on the design, and the number of overlapping upper portions may be not only two but also three. Therefore, in the conventional technology, which has a small tolerance and the thickness is limited, the number of overlapping portions and the number of upper layers must be reduced, and the design choice is always restricted, and shoes with a novel design are manufactured. It was difficult to do.

[0008]

SUMMARY OF THE INVENTION Accordingly, the present invention is directed to the upper edge portion of the outer bottom material mainly at a portion where burrs are likely to be generated due to the injection pressure at the time of injection molding of the outer material such as an upper material overlapping portion. At the relative position of the mold assembled at the time of shoe molding, an elastic member (string-like rubber packing) is provided at a height substantially equal to the upper edge of the outsole and in a groove provided at the peripheral edge of the last housed in the upper. The object is to solve the above-mentioned problem by providing.

Here, the width of the elastic member (string-shaped rubber packing) is about 5.0 to 6.0 mm and 1 mm from the last surface.
It is desirable that the cross section of the cord has a convex curved surface at the center at the outside, and the height of the cord-shaped rubber packing relative to the upper edge of the outer surface of the outer bottom surface is side model.
It is important to provide the upper edge of the shield in correspondence with the side lip 11. The attachment position of the elastic member provided on the last is determined by the design and the structure of the overlapping portion. In some cases, the entire circumference of the last may be sufficient, and in some cases only a part of the elastic member may be sufficient. Is determined by

[0010]

For this reason, the object of the present invention is to solve the problem by injection molding an outsole material with an upper and a backing material sandwiched between a last and a side mold side lip 11. In the shoe manufacturing method of manufacturing shoes by doing, when the elastic member is arranged at a position corresponding to the side lip on the last side and at a position corresponding to the overlapping portion of the upper, when the side mold is tightened A shoe manufacturing method, characterized in that the thickness of the overlapping portion of the upper can be absorbed by the elastic member, and the last used in the shoe manufacturing method,
An elastic member is disposed at a predetermined position of the last.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view (although the perspective direction is different) corresponding to the method of manufacturing shoes according to the present embodiment corresponding to FIG. 2, FIG. 2 is a sectional view of an elastic member provided on the last 9, FIG. 3 is a perspective view of the last 9, FIG. 4 is a sectional view showing a relationship between the last 9 and the side lip 11, and FIG. It is sectional drawing. The same members as in the conventional example will be described using the same reference numerals.

In the figure, 2 is the outsole, 3 is the upper edge of the rising outsole, 4 is the upper, 5 is the upper overlapping portion,
7 is a backing material, 8 is an insole, 9 is last, 10 is side mold, 11 is side lip, 12 is bottom mold, 14
Is a string rubber packing as an elastic member, and 15 is a groove for the string rubber packing. In the present invention, since the structure of the last 9 is particularly featured, this point will be mainly described, and the description of the other components which are the same as those of the conventional example will be omitted.

The last 9 mainly includes a portion where burrs are likely to occur due to an injection pressure during the injection molding of the outer sole material, such as the upper material overlapping portion 5, and the like, along with the upper edge of the outer sole when forming shoes. A groove 15 for providing an elastic member is formed in a peripheral portion having a height corresponding to the rising edge 3 of the rising edge of the outer bottom at a relevant position of the assembled mold. At least one end of the groove 15 is formed to be gently inclined so that a string-shaped rubber packing as the elastic member 14 can be inserted into the groove 15.

Although the groove 15 is formed as one relatively long groove along the longitudinal direction of the last 9, it is formed on the last side as a short groove at each location where burrs are expected to occur. It is also possible. Further, in order to prevent the elastic member (string rubber packing) provided in the groove from falling off, in this embodiment, as shown in FIG. 4, the cross section of the groove 15 is formed in a substantially T-shape having a flange 15a. And this groove 15
A substantially T-shaped cord-shaped rubber packing 14 as shown in the figure can be inserted therein. The groove 15
As long as it has a function of preventing the string-shaped rubber packing 14 from falling off, various cross-sectional forms such as an inverted taper can be adopted.

On the other hand, the string-like rubber packing 14 as an elastic member inserted into the groove 15 is formed to have a cross section as shown in FIGS. 2A and 2B. The material of the string-like rubber packing 14 is as follows. It is desirable to use natural rubber or the like having moderate elasticity. Also, the cross-sectional shape of the string-shaped rubber packing should be reverse tapered as shown in (a),
As shown in (b), various shapes may be adopted according to the groove, such as a substantially T-shape with a flange 14a at the bottom. Further, the cross-sectional dimensions of the string-shaped rubber packing are those having a width E of about 5.6 mm and a height of about 10 mm.

Next, the vertical positional relationship of the string rubber packing embedded in the last will be described. In FIG. 1, the last 9 covered with the upper 4 of the shoe, the bottom mold 12 and the side mold 10 are assembled, and the side mold 1 is in a state before the outsole is formed by injection.
The aforementioned groove 15 is located on the last 9 side along the horizontal plane on the center line of the side lip 11 at the upper end of the zero. The above-mentioned string-shaped rubber packing 14 is housed in the groove of the last 9. When the string-shaped rubber packing 14 is housed in the last groove 15, the section of the string-shaped rubber packing 14 has a convex curved surface. , Protruding from the side surface of the last by about 1 mm. The thickness of the side lip is about 2.5 mm, similar to the conventional one, and the string-shaped rubber packing may be provided on the last using an adhesive or the like as necessary. It is possible. The last 9 is made of aluminum or resin.

A method for manufacturing a shoe according to the present invention using the last will be described. In the present embodiment, as a pre-process for forming the outsole, the last 9 covered with the upper 4 of the shoe, the bottom mold 12 and the side mold 10 are assembled, and in the state before the outsole is injection-formed, the last 9 is formed. 9
When the above-described side mold 10 is tightened on the side, the elastic member 14 is disposed on the last 9 side, so that the upper side is formed by the side lip 11 by the thickness of the upper material of the overlapping portion of the upper. The elastic member 14 is deformed and pushed. That is, as shown in FIG. 5, the elastic member 14 is elastically deformed and pushed in by the thickness of the upper material of the upper overlapping portion, and is pushed into the elastic member 14 as shown by the pushing portion 16 to be recessed.

In the assembled state as described above, the gap S due to the step is formed in the upper overlapping portion 5 as in the prior art.
Is not formed, so that even when the foamed polyurethane at the outsole is injection-molded, the foamed polyurethane is prevented from flowing out due to the injection pressure at that time, and the occurrence of burrs is prevented.

In the above shoe manufacturing method, an elastic member is provided on the side of the last 9 corresponding to a location where burrs occur, such as an upper overlapping portion, and the generation of a gap due to a step is prevented by deformation of the elastic member. However, the elastic member to be used is not limited to the string-shaped rubber packing as long as it can absorb the step on the upper side when the side mold is tightened with a predetermined force, and various materials can be used. Also, the grooves provided in the last can be individually formed corresponding to the locations where burrs occur. Therefore, the above-described embodiment is merely an example in every aspect, and should not be construed as limiting. All modifications and changes belonging to the equivalent scope of the claims are within the scope of the present invention.

[0020]

According to the prior art, it is necessary to strongly tighten the side mold in order to prevent burrs from flowing out from the overlapped portion of the upper, and as a result, a tightening mark 13 of the side lip remains at the lower portion of the upper. At the same time, the upper material in that part was often cut by the edge of the side lip. If the side mold is loosened to prevent the upper from being cut,
If burrs are unavoidable and the design or the design necessity is necessary, the number of places to be overlapped cannot be increased. It was extremely difficult to suppress the generation of burrs even if the joints were thinned by thinning each other. On the other hand, according to the present invention, in a state where the mold is assembled, the thickness of the overlapping portion of the upper is arranged on the last side by the lip on the side mold side and absorbed by the elastic member,
Since the generation of a gap due to a step is prevented, the risk of burrs coming out of the overlapped portion is eliminated, so that the number of layers can be increased, such as two or three stacked layers in the upper portion. Further, it is not necessary to narrow the overlapping portion, and it is possible to obtain a great advantage that the quality of the product is improved and the range of choice of the upper design is widened. Excellent effects can be achieved.

[Brief description of the drawings]

FIG. 1 is a perspective view of a main part showing an arrangement of a side mold and a last when manufacturing a shoe according to an embodiment.

FIG. 2 is a sectional view of an elastic member provided on the last.

FIG. 3 is a perspective view of a last.

FIG. 4 is a sectional view showing a relationship between a last-side elastic member and a side lip.

FIG. 5 is a sectional view taken along line CC in FIG.

FIG. 6 is a perspective view of a conventional completed shoe.

FIG. 7 is a perspective view of a main part corresponding to a part A in FIG. 6, showing an arrangement of a side mold and a last when the shoe is manufactured.

FIG. 8 is a perspective view of a side mold.

FIG. 9 is a sectional view taken along line BB in FIG. 7;

FIG. 10 is a cross-sectional perspective view showing a fastening mark of a side lip of a conventional product.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Shoe body 2 Outsole 3 Outsole rising upper end part 4 Upper 5 Upper-overlapping part 6 Burr 7 Backing material 8 Middle sole 9 Last 10 Side mold 11 Side lip 12 Bottom mold 13 Tightening mark by side lip 14 Elasticity Member (string-shaped rubber packing) 15 Groove for rubber packing 16 Overhanging and pushing part of overlapping part to rubber packing side

Continued on the front page (51) Int.Cl. ⁶ Identification code FI B29K 105: 20 B29L 31:50

Claims (5)

[Claims] 1. An upper and a backing are provided by a last and a side molding.
In a shoe manufacturing method for manufacturing a shoe by injection molding an outsole material in a state of being sandwiched between the side lip 11 and a side lip 11, the upper side is overlapped at a position corresponding to the last side lip. An elastic member is disposed at a position corresponding to the portion, and the thickness of the overlapped portion of the upper can be absorbed by the elastic member when the side mold is tightened. 2. The shoe manufacturing method according to claim 1, wherein the elastic member is embedded in the entire circumference of a predetermined position at the lower part of the last or a part thereof. 3. The shoe manufacturing method according to claim 1, wherein the surface of the elastic member embedded in the last protrudes by about 1 mm from the surface of the last. 4. The method according to claim 1, wherein the elastic member is a string-shaped rubber packing. 5. A last for use in a method of manufacturing shoes,
An elastic member is disposed at a predetermined position of the last.