JPH0470885B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) This invention relates to an injection molding method for shoes.

(Prior art) Conventionally, as shown in Japanese Patent Publication No. 25-1083, a groove is provided around the bottom periphery, an elastic body such as hard rubber is embedded in the groove, and the last is covered with the elastic body. After suspending the shoelaces and pressing the lip portions of the side molds 2, 2 onto the elastic body from the sides through the hanging portions of the shoelaces, the shoes are introduced into the sole molding cavity formed at the lower side of the last. A shoe forming method is known in which the sole is formed by heating and pressurizing the formed shoe sole molding material, and at the same time, the sole is adhered to the hanging part of the shoe shoe.

When using this method, the lip part of the side mold is pressed against the elastic body embedded in the last through the hanging part of the shoe sole, so the shoe cover material has the same thickness. In this case, a gap is not formed between the hanging part of the shoe cover and the lip part of the side mold, and the sole molding material does not protrude as burrs around the bottom of the shoe cover, resulting in a good shoe.
In recent years, shoe injection molding has been adopted as a production method for small-lot, high-mix shoe production.As a result, expensive molds must be prepared for each product type, leading to increased mold costs and high costs. It's getting old. This is because even shoes with the same pattern design have different wall thicknesses depending on the material used to make the cover, such as natural leather shoes, natural leather, synthetic resin sheets, fabrics, or composites of these materials. When the mold used for the injection molding method for shoes with the same pattern design is applied to the injection molding method for shoes with the same pattern design, the lip part of the side mold will be placed around the bottom of the last due to the difference in the thickness of the cover material used. When trying to press the elastic body embedded in the shoe sole, if the lip material is too thin, a gap will be formed between the lip part and the elastic body, which may cause burrs to form around the bottom of the shoe sole when forming the shoe sole. If the shoe cover material is too thick, the hanging portion of the shoe cover may be cut off by the lip portion, resulting in a significant increase in the defect rate of the resulting shoes. Therefore, even when molding shoes with the same pattern design, it is necessary to prepare many types of molds depending on the thickness of the shoe cover material, resulting in a significant increase in cost.

(Problems to be Solved by the Invention) This invention allows the same mold to be used for multiple types of shoes with the same pattern design,
The aim is to provide inexpensive shoes.

(Means for Solving Problems, Embodiments) The present invention will be described below with reference to drawings showing the state of implementation. The slope 11 is covered with the last 1 made of After closing, the last 1 with the hanging cover a is lowered, and the lip parts 21, 21 of the side molds are brought into contact with the upper edge of the hanging part a' of the cover covered with the slope 11 of the last. After the lip parts 21, 21 are pressed against the upper edge of the hanging part a' of the shoe cover from below by the rising pressure of the side molds 2, 2, the sole molding cavity is formed on the lower side of the last 1 by a conventional method. The gist of the invention is an injection molding method for shoes, which is characterized in that a shoe sole molding material is injected into step 4 to mold the shoe sole b, and at the same time, the shoe sole b is bonded to the hanging part a' of the shoelace. be.

In this invention, the slope 11 formed on the lower peripheral edge of the last 1 will be uniform over the entire circumference of the last 1 if the hanging part a' of the cover has a uniform thickness over its entire circumference. It is sufficient if it is tilted at an angle,
In addition, the hanging part a′ of the toe cover is a toe reinforcement piece, a heel reinforcement piece,
If the part is partially thickened by a side decoration piece, etc., the slope 11 should be made from the other parts at the toe, heel, side, etc. of the last 1 corresponding to the thick part. By forming a steep slope, that is, by configuring the slope angle (α) formed by the last bottom surface 10 and the slope 11 to be large, the lip portion 21 is formed by vertical movement of the side molds 2, 2 with a constant width. , 21 and the last slopes 11, 11 may be made larger than the other portions to correspond to the partially thick hanging portion of the cover.

In this invention, the side molds 2, 2 may be moved up and down by a hydraulic mechanism, etc.
20 are provided with sliding gaps 201, 201 and are slidably attached via springs 22, 22. After the side molds 2, 2 are closed, the last 1 with the cover a suspended is attached to the side mold 2. , 2, the lip portions 21, 2 are raised by the rising pressure of the side molds 2, 2 due to the repulsive force of the springs 22, 22.
1 can be brought into pressure contact with the upper edge of the hanging part a' of the cover from below, which is convenient.

In addition, in the drawing, 3 indicates a bottom mold.

(Operations and Effects of the Invention) As described above, in the present invention, the lower peripheral edge of the last 1 on which the cover a is suspended is constituted by a slope 11 inclined inwardly with respect to the bottom surface 10, and the slope 11 is covered with a cover. The lip portions 21, 21 of the side molds, which are slidable in the vertical direction from below, are pressed against the upper edge of the hanging portion a' of the hanging part A' by the rising pressure of the side molds 2, 2. If it is a shoe with a pattern design, by adjusting the vertical movement of the side molds 2, 2 depending on the difference in the thickness of the sleeve a,
The lip portions 21, 21 of the side mold can be pressed against the upper edge of the hanging portion a' of the cover without any gaps.

Therefore, if the shoes have the same pattern design during sole injection molding, even if the same mold is used, the sole molding material will not burr and protrude around the bottom of the shoe cover a, making it possible to produce inexpensive shoes. can be provided.

[Brief explanation of the drawing]

The drawing is a sectional view of a main part showing the state of implementation of the present invention. Explanation of symbols, 1...last, 10...bottom, 1
1...Slope, 2...Side mold, 20...Support stand, 201...Sliding gap, 21...Rip part,
22...Spring, 3...Bottom mold, 4...Sole molding cavity, a...Flip cover, a'...Hanging part, b...Sole, α...Inclination angle,...Gap width.

Claims (1)

[Claims] 1 A last 1 consisting of a slope 11 whose lower periphery is inclined inward with respect to the bottom surface 10 covers the slope 11 and hangs a cover a, and then a side which can freely slide horizontally and vertically The molds 2, 2 are moved horizontally to face each other and are closed, and the last 1 with the cover a suspended is lowered so that the lip portions 21, 21 of the side molds are covered with the slope 11 of the last. At the same time, the lip parts 21, 21 are brought into contact with the upper edge of the hanging part a' of the cover.
The sole molding material is injected into the sole molding cavity 4 formed on the lower side of the last 1 by a conventional method. An injection molding method for shoes, characterized in that, at the same time as the sole b is molded, the sole b is bonded to the hanging part a' of the shoe.