KR20100032561A - Shoes midsole forming apparatus using induction heating - Google Patents

Abstract

PURPOSE: A shoe midsole forming apparatus using induction heating is provided to reduce the manufacturing time by uniformly rapidly heating a mold. CONSTITUTION: A shoe midsole forming apparatus using induction heating comprises a mold unit(10), an induction heating unit(20), and a press unit(30). The mold unit is composed of upper and lower molds(12,14) in which foamed midsole material(P) is inserted. The induction heating unit is composed of upper and lower induction heating units(20a,20b) which are coupled to the upper and lower sides of the upper and lower molds, respectively. The induction heating unit heats the mold unit using an electromagnetic field so that the midsole material is heated and expanded. The press unit is composed of an upper press(32) and a lower press which are coupled to the upper and lower sides of the upper and lower induction heating units, respectively, and molds the heated midsole material by pressing the mold unit.

Description

Shoes midsole forming apparatus using induction heating

The present invention relates to a shoe midsole molding apparatus using induction heating, and more particularly, to a shoe midsole molding apparatus capable of forming a shoe sole by rapidly heating a mold by an induction heating method.

Recently, shoes with various designs and special shoes with various functions have been released, and the basic structure of shoes that are generally released is similar.

That is, the shoe is composed of the sole and the upper coupled to the upper, the sole is composed of the outsole (sole) forming the sole and the midsole (sole) forming the midsole.

Usually outsole is made of rubber material to meet the function for wear resistance and anti-slip, and the midsole is manufactured to absorb the impact by foam molding a synthetic resin material of various materials.

Here, the synthetic resin used as the material of the midsole (hereinafter referred to as 'middle sole') is mainly used in urethane foam, PVC or TPR and EVA, but is lightweight, yet excellent in absorbing shock, resilient, preventing discoloration and environmental pollution Synthetic resin material mainly composed of EVA is used.

The midsole of EVA material is usually produced by two methods, injection injection method and press method. Injection injection method injects liquid EVA material into the injection mold into a mold that has a desired shape and is reduced in shape. When the mold is opened after a suitable time, the midsole is molded while being exposed to the atmosphere while the crosslinked midsole material inside the mold is expanded and expanded. The injection injection method has the advantage of being able to mass-produce, but in the process of foam expansion and cooling, the defective rate is not only high due to the instability of the dimension, but also the foam-expanded midsole has a shine. There is a disadvantage in that it is applied only to low-cost products and do not apply to expensive products.

Meanwhile, the press method processes the EVA foam sponge separately expanded and foamed a little larger than the desired shoe shape to make a shape, and then injects the processed material into the midsole mold to press, heat and cool the entire mold by a press. You are done.

1 is a schematic view showing a shoe sole molding apparatus according to a conventional press method.

As shown, a mold for forming a midsole is coupled between upper and lower presses, and a first foamed midsole material is inserted into the mold and then pressurized while being heated by a press.

FIG. 1 (a) shows a heat press 2 for inserting a midsole material p into a mold 1 to heat and pressurize it, and a cold press 3 for transferring the pressurized mold 1 to a cooling press. The press method made is shown. A plurality of flow paths are formed in the hot press 2 and the cooling press 3, and a heating medium (heat medium oil, steam, etc.) passes through the heating flow path 4 formed in the hot press 2 to form a mold 1. ) Is heated to form the midsole material p. Thereafter, the mold 1 is moved to the cooling press 3 so that a coolant (water, freon, etc.) flows through the cooling passage 5 formed in the cooling press 3 so that the cooling press 3 is cooled. The mold 1 thus heated is cooled to complete molding of the midsole.

FIG. 2 (b) is another conventional structure, which consists of one press 6 instead of two heat presses 2 and cooling presses 3, and a plurality of flow paths 7 are formed in the mold 1 itself. The heating medium or the coolant is alternately supplied through the flow path 7, and the midsole material p is heated and cooled while being pressed by the press 6 to form a midsole.

Unlike the injection injection method, such a press method is suitable for high-priced products because there is no shine on the surface, but there is a problem in that productivity is low. That is, the heating time due to heat transfer is long because the press or the mold itself is heated by the heat medium, and since the cooling time is further cooled with the refrigerant, it takes a long time to produce a midsole.

In addition, since the heating and cooling method by the heating medium or the refrigerant is not a method of heating the entire mold at the same time, the mold may not be uniformly heated, and thus the heating temperature may vary depending on the portion of the midsole material. This is because the expansion of the midsole material does not occur uniformly may cause a failure of the finished product.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems and an object of the present invention is to provide an insole molding apparatus using induction heating capable of forming a midsole by rapidly and uniformly heating the mold simultaneously using induction heating.

In addition, to provide a shoe sole molding apparatus using induction heating coupled to the induction heating unit integrally to the press to simplify the structure.

In order to achieve the above object, the present invention provides a device for manufacturing a shoe midsole by molding a foam-expanded midsole material, the upper mold, the bottom mold and the metal mold is inserted into the foam expansion midsole material and ; Induction heating means consisting of the upper induction heating portion coupled to the upper mold and the lower induction heating portion coupled to the lower mold, and induction heating means for heating and expanding the inserted midsole material by generating an electromagnetic field by alternating current. and; And an upper press coupled to the upper induction heating unit and a lower press coupled to the lower induction heating unit, and presses the mold to form a heated midsole material.

Preferably, the upper induction heating unit, the lower induction heating unit is coupled to the AC voltage supplying AC, an induction coil winding in a spiral shape and receiving an AC from the AC voltage generator to form an electromagnetic field, the upper and lower coupling coils And an insulating plate to insulate and insulate the mold and the press.

Preferably, the auxiliary heating body is further provided between the mold and the heat insulating plate made of a metal material having a greater thermal conductivity than the mold.

Preferably, the mold is characterized in that the through-flow refrigerant channel through which the refrigerant flows to form a rapid cooling of the mold is formed.

The effect of the present invention by the configuration as described above is because the mold is heated uniformly as a whole by the induction heating means significantly reduces the midsole production time and is heated evenly to the midsole, the quality of the defect is reduced and guaranteed.

In addition, since the induction heating means is integrally coupled to the press, the manufacturing equipment is simple and the efficiency is high, and mass production is possible.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the present invention.

Figure 2 is a cross-sectional view showing a shoe sole molding apparatus using induction heating according to an embodiment of the present invention, Figure 3 shows an exploded perspective view of the induction heating means shown in FIG.

The present invention largely consists of a mold 10, the induction heating means 20 and the press 30.

First, the mold 10 will be described. An upper mold 12 and a lower mold 14 are formed, and a midsole-shaped space is formed so as to insert a foamed-expanded midsole material p therebetween.

In addition, the material of the mold 10 is made of a metal. In general, the mold is made of a metal having high strength, but since the mold is heated by the induction heating means 20 to be described later, the mold must be made of a conductor so that a current can flow. Therefore, it should be made of metal, and usually aluminum, copper and iron can be used, and Al 50 series is mainly used in the field.

In addition, a plurality of through-flow refrigerant passages 16 are formed in the mold 10. The refrigerant passage 16 may have a passage shape so that the refrigerant flows, and a pipe (not shown) through which the refrigerant flows, such as a known water jacket, may be embedded in the mold 10. As a result, the coolant cools the mold 10. As the refrigerant, water, freon, nitrogen gas, or the like may be used.

Next, the induction heating means 20 will be described.

The induction heating means 20 is composed of the upper induction heating unit 20a and the lower induction heating unit 20b, and each configuration is the same, so it will be described together.

The upper portion 20a and the lower induction heating portion 20b are composed of an AC voltage generator 22, an induction coil 24, and a heat insulating plate 26. The AC voltage generator 22 is generally a device for supplying an AC current. It is preferable to be able to adjust the current, and since it is a known configuration, detailed description thereof will be omitted.

In addition, the induction coil 24 has a spiral shape, that is, a wire wound in a spiral shape on a plane, as shown in FIG. 3, connected to the AC voltage transformer 22 and the upper mold. 12 and the lower mold 14, respectively. The material of the induction coil 24 is a conductive conductor, usually copper.

Here, we will briefly explain the principle of induction heating.

When the induction coil 24 is subjected to alternating current, a magnetic field is formed around the induction coil 24 by alternating current to form a magnetic force line, as shown in FIG. 3, and the magnetic force line is made of a metal material. Pass through. At this time, since the direction of the alternating current flowing through the induction coil 24 is continuously changed, the magnetic force lines are alternately changed, and according to the change of the magnetic force lines, the induction current is generated in the mold 10, and thus the resistance due to the current in the metal is caused. Heat is generated by hysteresis loss or hysteresis loss caused by the loss and the change of the magnetic force. This is called induction heating, and in this way, various heated objects are heated according to the purpose.

The induction heating as described above is a well-known technique widely used in various fields such as metal melting and plating, and the required power is calculated by the following reference formula.

Where M is the weight of the mold (kg), C is the specific heat of the mold (J / gK), T is the heating temperature (K), and t is the heating time (s).

By setting and calculating the values, the power required for heating the mold is determined, and the capacity or the physical properties of the AC voltage 22 and the induction coil 24 may be determined based on the calculated power. For reference, the mold temperature required for forming the midsole is 200 ~ 300 ℃.

On the other hand, the upper and lower portions of the induction coil 24 is provided with a heat insulating plate 26 having a heat insulating and insulating function. Because when the mold 10 is heated by the induction coil 24, not only the foamed and expanded midsole material p is heated but also heat can be transferred to the induction coil 24 itself. Therefore, in order to block such heat transfer, the insulation plate 26 may be further inserted between the mold 10 and the induction coil 24. In addition, the heat generated from the induction coil 24 itself may be described below. Insulating plate 26 is further provided between the induction coil 24 and the press 30 to block the transmission to the side.

In addition, the insulation plate 26 does not generate induction heating when the induction coil 24 in which the current flows is in direct contact with the mold 10 or the press 30 not only functions for insulation but also a press to be described later. It shall be capable of withstanding the load of (30).

Therefore, the insulating plate 26 can withstand 300 ° C or more and at the same time function as an insulator and can withstand the load of the press 30 to be described later, such as phenolic resins such as bakelite, teflon, and MC nylon. Insulation may be used.

Next, the press 30 will be described. The press 30 is composed of an upper press 32 and a lower press 34. The upper press 32 is coupled to an upper side of the upper induction heating unit 20a and the lower press ( 34 is coupled to the lower induction heating unit 20b.

As is known, the press 30 is a device for providing a pressing force by a power such as hydraulic pressure, and a detailed description thereof will be omitted.

On the other hand, the auxiliary heater 40 may be further inserted between the mold 10 and the heat insulating plate 26 as another embodiment of the present invention.

The auxiliary heating body 40 is made of a metal material having better electrical conductivity than the mold 10. In the case of induction heating, the electrical conductivity is higher than that of the mold 10 due to induction heating since the heating is faster. The larger auxiliary heating body 40 is heated faster to allow rapid heat transfer to the mold 10 so that the mold heating rate can be made faster.

For example, as described above, the Al 10 series, which is mainly aluminum, is used in terms of strength and cost. However, since aluminum has excellent thermal conductivity but has a smaller electrical conductivity than other metals, it is preferable to further insert and use the auxiliary heating body 40 made of a material such as copper and SUS 40 having excellent electrical conductivity.

Hereinafter will be described briefly with respect to the operation of the present invention.

As described in the background art, the mid-expanded midsole material p is first introduced between the upper and lower molds 14 and 14. In addition, when the AC voltage 22 of the induction heating means 20 causes AC to flow through the induction coil 24, an electromagnetic field is formed by the induction coil 24, and thus, the upper part 12 and the lower mold. (14) is heated at once as a whole.

In this state, the upper 32 and the lower press 34 are operated to heat and press the mold 10, respectively, and when a predetermined time elapses, the foamed-inflated midsole material p is formed into a desired shape.

In order to cool the mold 10, the AC voltage 22 is turned off to cut off the current, and when the refrigerant passes through the refrigerant passage 16 formed in the mold 10, the mold 10 is rapidly cooled. The molded midsole material (p) is also cooled and completed.

Finally, the work is completed by releasing the load of the press 30 and removing the completed midsole by opening the mold 10.

As described above is only an embodiment of the present invention, the true technical protection scope of the present invention should be determined by the following claims.

1 is a schematic view showing a shoe sole molding apparatus according to a conventional press method.

Figure 2 is a cross-sectional view showing a shoe sole molding apparatus using induction heating according to an embodiment of the present invention.

3 is an exploded perspective view of the induction heating means shown in FIG.

<< Explanation of main parts of drawing >>

10: mold 12: upper mold

14: lower mold 16: refrigerant path

20: induction heating means 20a: upper induction heating unit

20b: lower induction heating part 22: AC voltage generator

24: induction coil 26: insulation plate

30: press 32: upper press

34: lower press 40: auxiliary heating body

p: Foam molded midsole material

Claims (4)

An apparatus for manufacturing a shoe midsole by molding a foamed expanded midsole material (p), A metal mold (10) formed of an upper mold (12) and a lower mold (14) and into which a foamed-expanded midsole material (p) is inserted; The upper induction heating unit 20a coupled to the upper mold 12 and the lower induction heating unit 20b coupled to the lower mold 14, the mold 10 by forming an electromagnetic field by alternating current Induction heating means 20 for heating and inflating the inserted midsole material by generating heat; An upper press 32 coupled to an upper side of the upper induction heating unit 20a and a lower press 34 coupled to a lower side of the lower induction heating unit 20b and heated by pressurizing the mold 10. Shoe midsole molding apparatus using induction heating, characterized in that consisting of; press (30) for molding the material (p). The method of claim 1, The upper induction heating unit 20a, the lower induction heating unit 20b, An AC voltage 22 for supplying AC, a coil wound in a spiral shape and receiving AC from the AC voltage 22 to form an electromagnetic field, and coupled to upper and lower portions of the induction coil 24, Shoe sole molding apparatus using induction heating, characterized in that the mold 10 and the press 30 and the heat insulating plate 26 to be insulated and insulated. The method of claim 2, Between the mold 10 and the heat insulating plate 26, Shoe sole molding apparatus using induction heating, characterized in that the auxiliary heating body 40 is made of a metal material having a greater electrical conductivity than the mold (10). The method according to any one of claims 1 to 3, In the mold 10, Shoe sole molding apparatus using induction heating, characterized in that the through-flow refrigerant channel 16 is formed through which the refrigerant flows to rapidly cool the mold (10).

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