KR100890905B1 - Mold device - Google Patents

Abstract

A molding device is provided to improve the productivity by reducing an injection molding cycle time as the fluidity is improved by the quick cooling and quick heating. A molding device comprises: a heater(110) in which the power source is applied while heating a first mold, arranged in the rear side of a cavity(C0); and a cooling water hole(120) in which the cooling water is injected when cooling the first mold, located in the rear side of the heater. The cooling water hole and the heater are alternately arranged toward the cavity surface as the cooling water hole is positioned between the adjacent heaters.

Description

Mold device {MOLD DEVICE}

The present invention relates to a mold apparatus, and more particularly to a mold apparatus capable of rapidly heating and rapidly cooling a cavity surface or a core surface.

Injection molding of synthetic resins and metals is a manufacturing method in which a mold having a cavity face and a mold having a core face are molded together, and a molded product having the same shape as the cavity is obtained by injecting and cooling a synthetic resin or metal in a molten state into a cavity formed therebetween. On the other hand, press molding is a manufacturing method which presses the molding inserted in a cavity, and produces a desired shape.

In injection molding, when the molten material is injected, the temperature of the mold is preferably the same as that of the molten material. This is because the flowability of the injected material and the pattern transfer property on the cavity surface can be improved, and the deformation of the molding due to the residual stress after the molten material hardens can be reduced. In addition, after the injection of the molten material is completed, the temperature of the mold must be lowered to allow the material to cool quickly, thereby shortening the cycle time of injection molding, thereby increasing productivity.

However, when the mold is heated to increase the temperature of the mold, the fluidity and the transferability are excellent, but the cooling time is increased, and the cycle time of the injection molding is long. On the other hand, when the size or volume of the mold is reduced so that rapid cooling is performed in order to shorten the cycle time, there is a problem in that deformation occurs in the product or the durability of the mold decreases due to weak rigidity.

In the case of synthetic resin injection molding, it is known that heating higher than the glass transition temperature of the synthetic resin has an effect on improving moldability and gloss by improving flowability and transferability. Accordingly, many methods have been proposed for improving the formability and quality of high-gloss housings and compact discs of AV equipment. For example, there exists a metal mold heating method using high frequency, and the metal mold heating method using high temperature steam. However, the high frequency heating method does not support product cost and mass production, and the steam heating method has a limitation in reducing the injection cycle time because a purge step for removing steam before adding cooling water to the mold is added.

On the other hand, for rapid heating of the mold, the performance can be improved by adding as many heat sources as possible, but for rapid cooling of the mold, it must be carefully designed in consideration of heat transfer performance, product dimensional deformation, mold rigidity and durability. do. As described above, when the cooling performance is increased through the method of reducing the volume or thickness of the mold, the rigidity of the mold is weakened, resulting in a problem in product dimension management or, above all, a weakness in mold life.

The present invention relates to a mold apparatus having heating and cooling means of a mold, wherein the mold is rapidly cooled after the injection is in progress or completed while maintaining the temperature of the mold to maintain the fluidity and transferability of the molten material to be injected. An object of the present invention is to provide a mold apparatus having excellent productivity by shortening the cycle time of molding.

In other words, if the mold temperature is increased, the cooling takes a lot of time, and the cycle time of the injection molding is long, and if the mold size is made small so that the mold can be rapidly cooled to reduce the cycle time, the mold rigidity and durability decrease. An object of the present invention is to provide a mold apparatus capable of simultaneously improving the double-sided properties.

In addition, the present invention is to produce a good quality product by uniformly controlling the temperature distribution over the entire mold surface, or to be heated to an arbitrary temperature for each part of the mold surface to mass-produce a product of sophisticated quality that meets user requirements In addition, it is an object to provide a mold apparatus that can reduce the cycle time in terms of mass production.

The present invention relates to a mold apparatus configured to form a molding at the time of joining the cavity surface formed on the first mold and the core surface formed on the second mold, and to take out the molding when separating, wherein the mold apparatus is arranged in plurality at the rear of the cavity surface. A heater to which power is applied during heating of the first mold; A cooling water hole arranged in plural to the rear of the heater and into which cooling water is injected during cooling of the first mold; It includes, wherein each of the coolant holes is provided between two heaters adjacent to each other to provide a mold apparatus, characterized in that the coolant holes and the heater is alternately disposed with respect to the cavity surface.

In one embodiment, the heater and the cooling water hole is also provided in the second mold, the heater provided in the second mold is arranged in plurality behind the core surface, the cooling water hole provided in the second mold is the first mold The cooling water holes and the heaters are alternately arranged with respect to the core surface by being arranged in plurality in the rear of the heater provided in the two molds, and each of the cooling water holes is located between two adjacent heaters.

In one embodiment, the mold apparatus, the temperature sensor for measuring the temperature of the first mold or the second mold; A heating unit for supplying power to the heater when the first mold or the second mold is heated; A cooling unit supplying cooling water to the cooling water hole through a cooling water line during cooling of the first mold or the second mold; An air unit supplying air to the cooling water hole through an air line to remove the cooling water of the first mold or the second mold; A unit controller for controlling operations of the heating unit, the cooling unit, and the air unit; It further includes.

In one embodiment, the unit controller applies the power independently to each of the heaters or injects the coolant independently of each of the coolant holes.

According to the present invention, it is excellent in fluidity and transferability through the rapid heating and rapid cooling, and the cycle time of injection molding is short, thereby providing a mold apparatus having excellent productivity.

The arrangement of the plurality of coolant holes provided at the rear of the heater corresponds to the empty space when the coolant therein is removed by the air, thereby reducing the heat conduction space behind the heater, thereby improving the heating performance by functioning as a heat insulating layer for the heater. In addition, since the cooling water holes are disposed between the heaters, the heat conduction space toward the cavity surface or the core surface is maximized to improve the cooling performance.

In this way, the cooling water holes and the heaters are characteristically arranged, and the heating and cooling performance of the mold due to heat conduction is very good. Therefore, even if the size and volume of the mold is increased to increase the rigidity and durability of the mold, sufficient cooling performance can be secured, and consequently, the economy is improved by increasing the replacement cycle of the mold.

 Characteristically, it is easy to control by using a plurality of heat transfer heaters and cooling water holes, and the entire mold surface may be heated and cooled to a uniform temperature, or in some cases, controlled at different temperatures for each part.

The controllability of the heating and cooling rate of the product is improved, which not only reduces the deformation of the molded part due to residual stress, but also shortens the production cycle time.

Therefore, it is optimized for the production of moldability and high gloss products, it is possible to suppress the formation of weld lines on the surface of the molded article, and can improve the formability and quality of high-gloss housings and compact discs of precision AV equipment.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In this process, the size or shape of the components shown in the drawings may be exaggerated for clarity and convenience of description. In addition, terms that are specifically defined in consideration of the configuration and operation of the present invention may vary depending on the intention or custom of the user or operator. Definitions of these terms should be made based on the contents throughout the specification.

The mold apparatus of the present invention can be used for press molding as well as injection molding of synthetic resins and metals, and the present invention is not limited according to the use of the mold apparatus. In addition, the terms cavity surface and core surface are attached to distinguish the molding contact surface formed in the first mold and the second mold, but the present invention is not limited in the meaning of the term itself.

The mold apparatus of the present invention includes a first mold and a second mold, a heater and a coolant hole provided in at least one of the first mold and the second mold. The cavity surface formed in the first mold and the core surface formed in the second mold form a cavity upon molding. Since the configuration of the heater and the coolant holes provided in the second mold is the same as the configuration of the heater and the coolant holes provided in the first mold, for the sake of clarity, the heater and the coolant holes provided in the first mold will be mainly described. Shall be. In addition, injection molding will be mainly described for convenience of description.

1 is a plan view showing the overall structure of the mold apparatus of the present invention. 2 is a plan view showing a state in which the first mold and the second mold of the present invention are joined. 3 is a plan view showing a state in which the first mold and the second mold of the present invention are separated. Figure 4 is a side cross-sectional view showing the arrangement of the cooling water hole and the heater of the present invention. 5 is a perspective view showing the appearance of the first mold of the present invention. A mold apparatus of the present invention will be described with reference to FIGS. 1 to 5.

First, referring to FIG. 1 as an embodiment, the heater 110 and the coolant hole provided in the first mold 10 as well as the first mold 10 and the second mold 20 provided in the mold apparatus of the present invention. 120 is shown. As shown, the heating unit 210, the cooling unit 220, and the air unit 230 are connected to the first mold 10, but the heater 110 and the coolant hole 120 are connected to the second mold 20. Of course, if it is provided that the second mold 20 can also be connected.

The temperature sensor 140 measures the temperature of the first mold 10 or the second mold 20.

The heating unit 210 supplies power to the heater 110 when the first mold 10 or the second mold 20 is heated, and the cooling unit 220 supplies the first mold 10 or the second mold 20. The cooling water valve 202 is opened at the cooling of) and the cooling water is supplied to the cooling water hole 120 through the cooling water line 204. The air unit 230 supplies air to the coolant hole 120 through the air line 205 to remove the coolant of the first mold 10 or the second mold 20.

The unit controller 240 controls the operations of the heating unit 210, the cooling unit 220, and the air unit 230 according to the feedback of the temperature sensor 140, and controls the operation of the entire mold apparatus 250. )

As an example, referring to FIGS. 2 and 3, the first mold 10 and the second mold 20 are combined, and then the molding material is injected into the cavity 9 to fill and maintain a predetermined pressure. In this holding pressure state, the first mold 10 or the second mold 20 is cooled by the cooling water to promote the molding of the material. When the molding of the material is completed, the entire process of cooling is completed by injecting air or compressed air to remove the cooling water of the cooling water hole 120. Then, as shown in FIG. 3, the first mold 10 and the second mold 20 are separated, and the extraction rod 30 is raised by the extraction cylinder 35 to take out the molded product 5. The mold is heated by applying power to the heater 110 during the separation and take-out process of the mold. When the mold reaches the controlled upper limit temperature, the mold is closed and a new injection of molding material is made.

Referring to FIG. 4 together with FIG. 1, the heater 110 is arranged in plural to the rear of the cavity surface C0 and power is applied when the first mold 10 is heated. When power is applied, the first mold 10 is heated until the control upper limit temperature is reached. The heater 110 takes the form of a cartridge and embeds the cartridge heater 110 by drilling a hole behind the cavity surface C0. The heater 110 is connected to the heating unit 210 through the power line 201.

When the synthetic resin, which is a molding material, is heated above the glass separation temperature, the flowability and transferability of the molding material may be improved, and thus a high gloss molding 5 having no weld line may be manufactured. The heating unit 210 capable of rapidly heating a mold by inputting a large amount of power can heat the entire area of the cavity surface C0 to a uniform temperature, as well as independently power each of the heaters 110. The temperature of the cavity surface C0 may be locally controlled by controlling with.

The cooling water holes 120 are arranged in plural to the rear of the heater 110, and the cooling water is injected into the cooling water when the first mold 10 is cooled. The cooling water circulates the cooling water until the first mold 10 reaches the control lower limit temperature. When the cooling is completed, the coolant valve 202 is locked and the air valve 203 is opened to circulate the air in the coolant hole 120. Accordingly, since the coolant remaining in the coolant hole 120 is completely removed, the heating time by the next heater 110 can be shortened.

At this time, since the arrangement of the coolant holes 120 corresponds to the empty space when the coolant therein is removed by air, the heat conduction space behind the heater 110 is reduced to form a heat insulation layer behind the heater 110. There is a characteristic.

The coolant hole 120 is connected to the cooling unit 220 by the coolant line 204, and is connected to the air unit 230 by the air line 205. Like the heating unit 210, the cooling unit 220 may independently control each of the cooling water holes 120, and may cool to a uniform temperature or to a different temperature locally on the entire surface of the cavity surface C0. . In order to improve the quality of the molding 5, the faster the mold heated to a higher temperature by the cooling water hole 120, the shorter the cycle time and the better the mass productivity.

Meanwhile, the present invention arranges the heater 110 and the cooling water hole 120 in a characteristic structure in order to improve heating performance and cooling performance. 4 and 5 illustrate this structure well.

That is, the cooling water holes 120 and the heaters 110 are alternately arranged with respect to the cavity surface C0 by being positioned between two heaters 110 adjacent to each other. Accordingly, two virtual straight lines C5 and C6 extending from the cross-sectional center point of each of the two coolant holes 120 adjacent to each other to the cavity surface C0 do not penetrate the heater 110 and are disposed on the cavity surface C0. Intersect before reaching. Therefore, when viewed from the exposed direction of the cavity surface C0, the virtual straight line 2 starting from the center point of the cross section of each of the two coolant holes 120 adjacent to each other, avoiding the heater 110, and reaching the cavity surface C0. The dogs C5 and C6 form a section in which the cavity surface C0 overlaps (the length of this section is L4).

Therefore, the space in which heat is conducted from the coolant hole 120 to the cavity surface C0 can be suppressed as much as possible by the heater 110. By increasing the heat conduction space, cooling performance is improved. For this purpose, the minimum value of the distance L3 between the cross-sectional center points of the two coolant holes 120 adjacent to each other is calculated with reference to FIG. 6. These minimum values are only for the case of the illustrated embodiment, but first reveal that not all embodiments of the invention are limited thereto.

6 is especially for the central part of the cavity surface C0. The distance between the center points of the cross-sections of the two coolant holes 120 adjacent to each other is L3, and the distance of the heater 110 to the cavity surface C0 is L1, and the distance of the coolant hole 120 to the heater 110 is shown. If L2 and the cross-sectional diameter of the heater 110 is defined as d, it can be seen that L3 is the minimum when the length L4 of the overlap section is 0, the following equation is established.

When the equation is summarized with respect to L3, it becomes the minimum value of L3 and can be expressed as the following equation.

× d ≒ 12.7 이 된다.If the diameter d of the heater 110 is 6 and L1 and L2 are 1.5d as the same value, min (L3) =

× d ≒ 12.7

On the other hand, it is preferable that the arrangement interval L3 of the coolant holes 120 is the same, but the center portion and the edge portion of the cavity surface C0 may be different from each other as necessary. The same is true of the arrangement interval between the heaters 110.

In addition, the cross section of the coolant hole 120 disposed farther from the heater 110 in the cavity surface C0 may be larger than the cross section of the heater 110.

Referring back to FIG. 4, in order to require uniform heating and cooling or to improve other temperature controllability, the imaginary first curve C1 connecting the plurality of heaters 110 to each other is about the cavity surface C0. The virtual second curve C2 connecting the plurality of coolant holes 120 to each other by a predetermined distance L1 may be spaced apart by a predetermined distance L2 from the first curve C1. L1 and L2 may be the same value or different values.

Although embodiments according to the present invention have been described above, these are merely exemplary, and it will be understood by those skilled in the art that various modifications and equivalent embodiments of the present invention are possible therefrom. Therefore, the true technical protection scope of the present invention will be defined by the following claims.

1 is a plan view showing the overall structure of the mold apparatus of the present invention.

2 is a plan view showing a state in which the first mold and the second mold of the present invention are joined.

3 is a plan view showing a state in which the first mold and the second mold of the present invention are separated.

Figure 4 is a side cross-sectional view showing the arrangement of the cooling water hole and the heater of the present invention.

5 is a perspective view showing the appearance of the first mold of the present invention.

6 is an explanatory diagram illustrating an arrangement structure of a cooling water hole and a heater of the present invention.

<Explanation of symbols for the main parts of the drawings>

5 ... moldings 9 ... cavity

9b ... core 10 ... 1st mold

20 ... 2nd mold 30 ... dispensing rod

35.Cooling cylinder 110 ... heater

112 Heating wire 120 Cooling water hole

140 ... temperature sensor 201 ... power line

202 ... coolant valve 203 ... air valve

204 Coolant line 205 Air line

210 ... heating unit 220 ... cooling unit

230 Air unit 240 Unit controller

250 ... integrated controller C0 ... cavity surface

C1 ... first curve C2 ... second curve

Claims (11)

In the mold apparatus is formed to form a molding during the molding of the cavity surface formed in the first mold and the core surface formed in the second mold and to take out the molding when separated, A plurality of heaters arranged rearwardly of the cavity surface and to which power is applied during heating of the first mold; A cooling water hole arranged in plural to the rear of the heater and into which cooling water is injected during cooling of the first mold; Including; Each of the cooling water holes is positioned between two heaters adjacent to each other, so that the cooling water holes and the heaters are alternately disposed with respect to the cavity surface. When the distance between the cross-section center points of the two coolant holes adjacent to each other, L3, the separation distance of the heater with respect to the cavity surface L1, the separation distance of the cooling water hole with respect to the heater L2, and the cross-sectional diameter of the heater as d , The minimum value min (L3) of the L3 is

The mold apparatus, characterized in that the cooling water hole and the heater is disposed to satisfy. The method of claim 1, The coolant hole and the heater are arranged such that two virtual straight lines extending from the cross-sectional center point of each of the two coolant holes adjacent to each other to the cavity surface intersect before reaching the cavity surface without passing through the heater. Mold apparatus. The method of claim 1, As seen from the exposed direction of the cavity surface, two virtual straight lines reaching the cavity surface starting from the cross-sectional center point of each of the two cooling water holes adjacent to each other form an overlap section in the cavity surface, The mold apparatus, characterized in that the cooling water hole and the heater is disposed. The method of claim 1, The virtual first curve connecting the plurality of heaters to each other is spaced apart from the cavity surface by a predetermined distance, and the virtual second curve connecting the plurality of cooling water holes to each other is spaced apart from the first curve by a predetermined distance. Mold apparatus, characterized in that. The method of claim 1, The cross section of the coolant hole is larger than the cross section of the heater. delete The method of claim 1, And the arrangement interval between the heaters is the same, and the arrangement interval between the cooling water holes is also the same. The method of claim 1, And the cooling water holes form a heat insulation layer for the heater behind the heater when the coolant therein is removed by air. The method of claim 1, The heater and the cooling water hole are also provided in the second mold, The heater provided in the second mold is arranged in plurality behind the core surface, Cooling water holes provided in the second mold is arranged in plurality behind the heater provided in the second mold, Each of the cooling water holes is located between two heaters adjacent to each other, so that the cooling water holes and the heaters are alternately disposed with respect to the core surface. The method according to any one of claims 1 to 5 and 7 to 9, A temperature sensor measuring a temperature of the first mold or the second mold; A heating unit for supplying power to the heater when the first mold or the second mold is heated; A cooling unit supplying cooling water to the cooling water hole through a cooling water line during cooling of the first mold or the second mold; An air unit supplying air to the cooling water hole through an air line to remove the cooling water of the first mold or the second mold; A unit controller for controlling operations of the heating unit, the cooling unit, and the air unit; Mold apparatus characterized in that it further comprises. The method of claim 10, The unit controller may be configured to apply power independently to each of the heaters or to inject cooling water independently into each of the cooling water holes.

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