JPS6124003B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the injection molding of a shoe in which the entire shoe body is made of an injection molding material and has a sole made of a material different from that of the shoe body or a material with a different color tone (hereinafter simply referred to as a different material). It concerns the molding method.

Conventionally, in order to manufacture injection-molded shoes in which the shoe body and sole are injection-molded using different materials, the shoe body and sole are first molded separately, and then the sole of the shoe body is separately molded. The prepared shoe sole can be pasted using adhesive, or only the shoe body can be injection molded using an injection molding method, and before the material has sufficiently hardened, the outer mold for the bottom can be inserted into a large space at the bottom. A two-stage method is used in which the shoe body and the sole are manufactured separately by replacing the outer mold with an outer mold and then injecting a different sole material into the gap in the bottom part. This method can be applied even when the shoe body and sole are made of different materials, but it requires a lot of work, and the sole of the shoe body is pasted together later. The disadvantage is that it is quite difficult to accurately position the sole at a predetermined position. In the latter case, the shoe body is first made by injection molding, and then a different injection material for the sole is re-injected before the injection material has sufficiently hardened, resulting in duplicative and complicated processes. Not only that, but it also requires a long time to replace the bottom mold and injection, resulting in low productivity and an increase in labor costs and equipment, which poses problems in industrial production.

The present invention solves the drawbacks of the above-mentioned conventional method, particularly simplifies the multi-step process, and injection molds the sole of the shoe body (the entire lace part and sole part) with a sole made of a material different from that of the shoe body. At the same time, we have developed a shoe injection molding method that allows shoes to be integrally molded and bonded in one step, and the work process is simple and easy.

The present invention can be applied to all shoe bodies that can be injection molded, and can also be applied to injection molded footwear having a double sole.

The present invention will be explained in detail below.

The present invention provides a sole periphery having a thickness and height that allows it to come into close contact with the inner wall of the sole mold by the injection pressure set around the entire circumference of the sole, and a treading part that is close to the non-stepping part. A shoe sole made of a flexible material having a predetermined hardness and having a hole into which an injection tube of injection material can be inserted is prepared in advance, and the injection tube having a protrusion on the inner surface is inserted into the hole of the shoe sole, and the shoe is finished. By inserting and holding the sole into the sole mold and holding the inner mold in a predetermined position, a sole space is formed between the inner mold and the sole, and then the outer mold is held in a predetermined position. Therefore, a shoe body space is formed between the outer mold and the inner mold, and a calculated amount of injection material is injected into the space from the injection tube into the sole space and the shoe body space. By bringing the sole periphery of the sole into close contact with the inner wall of the sole mold, and by bringing the part of the sole near the hole into close contact with the outer surface of the injection tube, leakage of the injection material to the sole surface side is prevented, and the space is filled with the injection material. A shoe made of a material different from the shoe body, characterized in that the shoe body, the sole of the shoe body, and the sole are integrally molded in one step by filling, and the holes in the sole are also filled with the injection material. The present invention relates to an injection molding method for shoes having soles.

Injection materials in the present invention include synthetic resin materials mainly composed of vinyl chloride resin, the aforementioned synthetic resin materials containing a foaming agent, urethane resin materials, thermoplastic rubber, and the like.

Next, an embodiment of the present invention will be further explained with reference to the drawings.

Figure 1 is a side sectional view showing the arrangement of the mold for the bottom part of the shoe body in the injection state, Figure 2 is an enlarged view of part A in Figure 1, and Figure 3 is part A after injection molding. FIG. 4 is an enlarged view of section B in FIG. 1, and FIG. 5 is an enlarged cross-sectional view of the injection tube.

In the figure, 1 is a shoe body, 2 is a separately made sole made of a different material from the shoe body, and a sole periphery 3 of a predetermined thickness and height is provided around the entire circumference. It has a hole 4 near the unstepped part into which an injection tube for injecting the injection material can be inserted into the stepped part, and the material is flexible and made of a material with a shore hardness of A80 degrees or less. It is being 5 is the bottom of the main body, 6 is the outer mold, 7
1 is an inner mold, 8 is a bottom mold, 9 is a main body space, 10 is a bottom space, 11 is a peripheral gap, 12 is an injection tube for injection material, and 13 is provided on the inner surface of the injection tube 12. 14 and 15 are the injection tube 1.
It is the inner diameter of 2.

The injection molding method of shoes according to the present invention is made of a material having a function corresponding to the purpose as shown in FIG. A shoe sole 2 made of a flexible material having a hardness of Shore hardness A of 80 degrees or less is pre-prepared. The shoe sole 2 is molded separately by a press, injection method or other method, and then inserted into a sole mold 8 of a mold. In this case, the hole 4 of the sole 2 is connected to the injection pipe 1 for injection molding of the main body 1 and the main body sole 5 provided in the sole mold 8.
Insert into 2. By inserting and fixing the sole 2 into the sole mold 8, the outer surface of the sole periphery 3 of the sole 2 and the sole mold 8
A peripheral gap 11 is created between the inner wall a and the inner wall a.

Next, by holding the bottom mold 7 in a predetermined position, a bottom space 10 is formed with the inner mold 7, and further, by holding the outer mold 6 in a predetermined position, a space between the outer mold 6 and the inner mold 7 is formed. A main body space 9 is formed.

Next, the injection material calculated according to the capacity of the main body 1 and the bottom part 5 of the main body is supplied from the injection tube 12 to the spaces 9 and 1.
Inject at 0. As a result of this injection, as shown in FIG. 2, when the injection material advances from the bottom space 10 to the main body space 9 in the direction of arrow A, it becomes flexible and has a specified thickness due to the injection pressure. The bottom peripheral edge 3 is pressed in the direction of arrow B and comes into close contact with the inner wall a of the bottom mold 8. Therefore, as shown in FIG. 3, the contact area between the sole periphery 3 and the sole mold 8 acts as a seal to maintain airtightness and prevent the injection material from entering between the sole 2 and the sole mold 8. To prevent. In this way, the injection material is transferred to the main body space 9.
The shoe sole 2 can be integrated with the bottom surface of the main body 1 via the main body sole 5.

As shown in FIG. 4, when the injection material is injected from the injection tube 12 in the direction of arrow C, the vicinity of the hole 4 in the sole 2 is pushed by the injection pressure, and there is a slight gap between the hole 4 and the outer surface of the injection tube 12. Since the seal acts in the direction of arrow D to close the gap created by the injection material, the injection material flows out to the outer surface of the sole 2, that is, to the contact point b between the sole 2 and the sole mold 8. Because there are no scratches, injection molded products are manufactured beautifully.

In order to uniformly inject the injection material of the shoe body 1, the hole 4 in the sole 2 is most preferably located in the center of the sole, that is, in the treading area close to the non-treading area. The reason why the sole periphery 3 is provided around the entire circumference of the sole 2 is that in conventional injection molded shoes, the surface where the bottom of the main body of the shoe and the sole are bonded is smooth, so the flat plates are overlapped and the periphery The superimposed cross sections are exposed. Therefore, the shoe body and the sole tend to separate easily due to repeated bending or strong impact during wear. In the present invention, since the sole is provided with a sole periphery, the adhesion area between the shoe body and the sole is large, and the sole periphery is surrounded by the sole periphery, which is integral with the sole, so that it can be easily resistant to impact and bending. It plays the role of a cushion for shoes, and there is no danger of it peeling off, and it also has the effect of making the appearance of the shoe beautiful, similar to when the bottom edge tape is attached. In addition, the sole 2 is made of a material that is flexible and has a hardness of Shore hardness A80 degrees or less because the shoe body 1 and the sole 5 are injection molded, so the injection material is injected from an injection tube into the spaces 9 and 10. In order to make it easier for the bottom peripheral edge 3 to come into close contact with the inner wall a of the bottom mold 8 and the hole 4 to come into close contact with the outer surface of the injection tube 12 when injected, flexibility is required since flexibility is required. If the hardness is Shore hardness A80 degrees or more, flexibility will be impaired, so the hardness is set to Shore hardness A80 degrees or less.

A sole periphery 3 having a thickness of 1.0 to 2.0 mm and a height of 2.0 to 4.0 mm is provided around the entire circumference of the sole 2. The reason for limiting the thickness to 1.0 to 2.0 mm is
This is because if it is thinner than 1.0 mm, the upper end may curl up when the injection material is injected, and if it is thicker than 2.0 mm, it becomes difficult to come into close contact with the inner wall a of the bottom mold 8.
The reason why the height is limited to 2.0 to 4.0 mm is that if it is less than 2.0 mm, it will be difficult to come into close contact with the inner wall a of the bottom mold 8, and if it exceeds 4.0 mm, there is a risk that the upper end will curl up.

Further, after filling the main body space 9 and the sole space 10 with the injection material from the injection pipe 12 to form the shoe main body 1 and the main body sole 5, when the injection pipe 12 is removed from the sole 2, the injection pipe 12 The injection material left inside the injection tube 10 may tear off from the tip of the injection tube 10 and not fill the hole 4 of the sole 2, leaving a hole, which may reduce the commercial value of the molded injection shoe. As shown in FIG. 4, by providing one protrusion 13 with an acute-angled tip on the inner surface of the injection tube 12, the remaining shape of the injection material injected from the injection tube 12 inside the injection tube 12 is reduced by the protrusion 13. Since the injection tube 12 is shaped with a notch in the part, when the injection tube 12 is removed from the sole 2, the injection material remaining inside the injection tube 12 is not torn off at the tip of the injection tube 12, and the protrusion 13 The torn pieces remain in the hole 4 of the sole 2, blocking the hole 4, resulting in a beautiful injection molded product.

That is, the inner diameter 14 of the injection tube 12a on the injection material outlet side of the injection tube from the protrusion 13 provided on the inner surface of the injection tube 12 is the same as the inner diameter 15 of the injection tube 12b from the protrusion 13, or As shown in the figure, by making the diameter of the inner diameter 14 larger than the diameter of the inner diameter 15, when the injection tube 12 is removed from the sole 2, the injection material remaining inside the injection outlet tube is removed from the protrusion 13. It is easier to tear apart than the .

As described above, the present invention enables the shoe body and the sole made of different materials to be integrally manufactured, without mixing the two materials, making it possible to reliably manufacture the shoe in a simple process. For example, even if the sole is made of a material different from the shoe body, especially a sole made of a non-injectable material, it can be securely fixed to the bottom of the shoe body by applying adhesive to the surface of the sole that contacts the bottom of the shoe body. It can be integrated. Furthermore, unlike the conventional case of manual attachment, it has the advantage that it is easy to accurately fix it to a predetermined location on the bottom of the shoe body. In addition, the mold required for injection molding is a two-stage method, which is different from the conventional method in which the shoe body is injected once, the mold for the sole is replaced, and then another injection is performed. It has great industrial value, as most of the injection molding machines currently available can be used as is.

In addition, the present invention can be applied to cases where the contact surface side of the sole has an uneven pattern as shown in the figure, as well as cases where it is a flat surface, and cases where a non-slip device is provided. The adhesive side to the bottom can be applied not only to flat surfaces but also to rough patterned surfaces.

[Brief explanation of the drawing]

The figure shows one embodiment of the present invention.
The figure is a side sectional view of the mold for the bottom part in the injection state of the shoe body, Figure 2 is an enlarged view of section A in Figure 1,
Figure 3 is an enlarged view of part A after injection molding, Figure 4 is the first part after injection molding.
FIG. 5 is an enlarged view of section B in the figure, and FIG. 5 is an enlarged cross-sectional view of the injection tube. In the diagram: 1: Shoe body, 2: Sole, 3: Sole rim,
4: hole, 5: bottom of main body, 6: outer mold, 7: inner mold, 8: bottom mold, 9: intermediate part of main body, 10: bottom space, 11: peripheral gap, 12: injection tube, 13 : Protrusion, 14: Inner diameter, 15: Inner diameter.

Claims (1)

[Scope of Claims] 1. A sole having a thickness and height that is close to the inner wall of the sole mold due to the injection pressure set around the entire circumference of the sole during injection molding, and which is close to the unstepped part. A shoe sole made of a flexible material having a predetermined hardness is prepared in advance and has a hole into which an injection tube of the injection material can be inserted into the tread part, and an injection tube having a protrusion is inserted into the inner surface of the hole of the sole. At the same time, the sole is inserted and held in the sole mold, and the inner mold is held in a predetermined position to form a sole space between the inner mold and the sole, and then the outer mold is held in a predetermined position. By doing so, a shoe body space is formed between the outer mold and the inner mold, and a calculated amount of injection material is injected from the injection tube into the sole space and the shoe body space, and the shoe sole is By bringing the lower periphery of the shoe in close contact with the inner wall of the sole mold and the part of the sole near the hole in close contact with the outer surface of the injection tube, leakage of the injection material to the surface of the shoe sole is prevented, and the space is filled with the injection material. An injection molding method for a shoe having a sole made of a material different from the shoe body, characterized in that the shoe body, the sole of the body, and the sole are integrally molded in one step by 2 The thickness of the bottom edge is 1.0 to 2.0 mm, and the height is 2.0 to 4.0 mm.
The injection molding method for shoes according to claim 1, wherein the injection molding method is mm. 3. The shoe injection molding method according to claim 1 or 2, wherein the shoe sole material has a hardness of Shore hardness A80 degrees or less.