KR20210029496A - chinhwangyeongjeog kaepiti peullaseutig sachul seonghyeong geumhyeong - Google Patents

Abstract

Disclosed is a plastic injection-molding mold having a cavity rapid heating device, in which a surface of a cavity is rapidly heated during filling of a resin to reduce a temperature difference between an injected resin and the surface of the cavity so that various appearance defects of a molded product caused by a large temperature difference between a cavity surface temperature and the resin are suppressed. The disclosed invention relates to a plastic injection-molding mold in which a product is molded by filling a cavity formed by coupling a fixed-side mold to a movable-side mold with a plastic resin, and the molded product is taken out by separating the movable-side mold, the plastic injection-molding mold including: a device for rapidly heating a surface of the cavity at a moment the resin is injected when the cavity is filled with the resin; and a device for rapidly cooling the surface of the cavity by operating upon completion of the filling of the resin. Accordingly, while the plastic resin is subject to the filling, a surface temperature of the cavity is maintained at a high temperature that is close to a temperature of the resin, so that an appearance defect of the molded product is suppressed. A cavity rapid heating device includes: a heating element installed at regular intervals along an edge of the cavity of the fixed-side mold; a heat conduction layer applied onto the surface of the cavity so that heat of the heating element is evenly spread over an entire surface of the cavity, and forming a contact surface with the resin that is actually subject to the filling; and a controller for controlling an operation of the heating element, wherein the heating element operates from a time point when the movable-side mold is separated from the fixed-side mold until the filling of the resin is completed to rapidly heat the surface of the cavity.

Description

Eco-friendly cavity plastic injection molding mold {chinhwangyeongjeog kaepiti peullaseutig sachul seonghyeong geumhyeong}

The present invention relates to a mold applied to a plastic injection machine. In particular, the present invention reduces the temperature difference between the injected resin and the cavity surface by rapidly heating the surface of the cavity when filling the resin, thereby suppressing various appearance defects of the molded product caused by the large temperature difference between the cavity surface temperature and the resin. It relates to a plastic injection molding mold having a rapid heating means for the cavity.

A typical example of a mold adapted to a plastic injection machine is shown in cross-sectional view in FIG. 1. 1A is a diagram showing a mold closed state, and FIG. 1B is a diagram illustrating an open state, that is, a drawing of a molded product.

As shown in the drawing, a general plastic injection molding mold is largely composed of a fixed-side mold 10 and a movable-side mold 20 installed to be movable with respect to the fixed-side mold 10. The fixed side mold 10 includes an upper support plate 11 and an upper plate 12 installed on the upper support plate 11. On the upper plate 12

A groove portion 12a that is depressed to a predetermined depth is formed in the central portion, and a guide hole 12b is formed on one side thereof. The movable side mold 20 includes a base finger plate 21 and the base finger plate 21 It is installed on and includes a lower plate 22 installed at a predetermined distance from the lower plate 21 by a pair of supporters 23. In the central portion of the lower plate 22, a core forming a product molding part, that is, a cavity, in cooperation with the groove 12a of the fixed-side mold 10 when the movable-side mold 20 and the fixed-side mold 10 are combined. 22a) is bound. And one side of the lower disk 22 is formed with a guide pin (22b) inserted into the guide hole (12b) of the fixed side mold (10). Above

The exact position is determined when the fixed side mold 10 and the movable side mold 20 are combined by the lead hole 12b and the guide pin 22b.

In addition, in the space between the lower plate 22 of the base plate 21 and the lower plate 22 of the movable side mold 20, a push plate 30 is installed to be movable. In addition, in this pushing plate 30, several pushing pins 31 are provided through the core 22b. The push pin 31 moves the push plate 30

By moving together, the molded product 40 is pushed and taken out.

As shown in FIG. 1A, when the mold is closed, the push plate 30 is positioned on the bottom finger plate 21 side, and accordingly, the tip of the push pin 31 coincides with the upper surface of the core 22b. In this state, the resin is filled into the cavity through a resin injection port (not shown), and the product 40 is molded.

When the resin filling is completed, after a predetermined curing time, the movable side mold 20 is moved to open the mold as shown in FIG. 1B. At this time, the molded product 40 is located on the core 22b. The product 40 is the continuous operation of the rolling plate 30

It is separated from and taken out from the core 22b by the push pin 31. After that, the mold is closed again, and the process of filling the resin is repeated.

However, in the general plastic injection molding mold as described above, since a high-temperature plastic resin is injected into a cavity in a cold state, the high-temperature resin is rapidly cooled while contacting the surface of the cold cavity. As a result, appearance defects along with various marks appear on the surface of the product to be molded. Conventionally, the defects in the appearance of the injection molding as described above cannot be fundamentally cured, and thus the surface of the product after injection is painted to secure the appearance quality of the product. Therefore, it is necessary to equip a separate painting facility to produce the desired plastic product, which increases the facility investment cost, and it is inevitable that the work environment is deteriorated due to contamination of the work space by paint. Moreover, paint acts as a factor of environmental pollution

As a result, it is necessary to exclude its use.

The present invention was devised in consideration of the above points, and by reducing the temperature difference between the cavity and the plastic resin by increasing the surface temperature of the cavity at the moment the plastic resin is injected, various appearance defects of the product due to the temperature difference are reduced. It is an object of the present invention to provide a plastic injection molding mold having a rapid heating means for a cavity that can be fundamentally eliminated.

Another object of the present invention is to provide a plastic injection molding mold having a cavity rapid heating means that does not require a separate painting operation for improving the appearance of a molded product by obtaining a beautiful appearance by the injection product itself.

The above object is to form a product by filling the cavity formed by the combination of the fixed-side mold and the movable-side mold to form a product, and to take out the molded product by separating the movable-side mold. , A means for rapidly heating the surface of the cavity at the moment the resin is injected when the resin is filled into the cavity, and a means for rapidly cooling the surface of the cavity by operating upon completion of the resin filling, whereby the plastic resin is filled. During the period, the surface temperature of the cavity is maintained at a high temperature close to the temperature of the resin, thereby suppressing the appearance defect of the product to be molded. Is achieved by

The cavity rapid heating means is coated on the surface of the cavity so that the heating element disposed by maintaining a certain distance along the edge of the cavity of the fixed side mold, and the heat of the heating element is evenly spread over the entire surface of the cavity, and A heat conductive layer forming a contact surface; And a controller for controlling the operation of the heating element, wherein the heating element rapidly heats the surface of the cavity while operating from a time when the movable side mold is separated from the fixed side mold to a time when filling of the resin is completed.

According to a preferred embodiment of the present invention, a heat insulating material guiding the heat diffusion direction of the heating element is disposed at the rear portion of each heating element, so that heat of the heating element is not diffused to other parts other than the heat conductive layer.

In addition, the cavity rapid cooling means, a plurality of cooling holes formed by maintaining a predetermined distance around the cavity of the fixed side mold; A cooling water supply source supplying cooling water circulating along the cooling hole; And a controller for controlling the supply of cooling water, wherein the cooling water is supplied for a predetermined curing time from a point when filling of the resin is completed, and the supply is stopped when the movable side mold is separated for product extraction.

According to this, since the plastic resin is injected and filled while the surface temperature of the cavity is increased, the temperature difference between the surface temperature of the cavity and the plastic resin can be minimized. Therefore, it is possible to suppress various appearance defects of molded products caused by a large temperature difference between the surface temperature of the cavity and the plastic resin. In addition, as the appearance of the molded product is suppressed, there is no need to perform a separate painting work, so there is no need to have unnecessary painting facilities. In addition, since painting work is eliminated, contamination in the factory by paint can be prevented, and emission of environmental pollutants can be suppressed.

As described above, the plastic injection molding mold according to the present invention includes means for rapidly heating and cooling the surface of the cavity, so that the surface temperature of the cavity is increased and the plastic resin is injected and filled, so that the surface temperature of the cavity and the plastic The temperature difference between resins can be minimized. Therefore, it is possible to suppress various appearance defects of molded products caused by a large temperature difference between the surface temperature of the cavity and the plastic resin.

In addition, according to the present invention, since the appearance of the molded product is suppressed, it is not necessary to perform a separate painting operation, so that unnecessary painting equipment is not required. In addition, since painting work is eliminated, contamination in the factory by paint can be prevented, and emission of environmental pollutants can be suppressed.

In the above, preferred embodiments of the present invention have been illustrated and described, but the present invention is not limited to the above-described embodiments, and is not departing from the gist of the present invention claimed in the following claims. Anyone with knowledge can, of course, implement various modifications, and modifications and variations are within the scope of the claims.

1A and 1B are cross-sectional views showing the structure of a general plastic injection molding mold, 1a is a mold closed state diagram, and 1b is a gold
This is the open state diagram.
2 is a cross-sectional view showing the structure of a plastic injection molding mold having a rapid cavity heating means according to an embodiment of the present invention,
3 is a detailed view of part A of FIG. 2 showing a cavity rapid heating means that is an essential part of the present invention,
4 is a view showing an injection machine employing a mold equipped with a rapid heating means for a cavity according to the present invention,
5 is a view showing a molding process using a mold according to the present invention and a mold surface temperature in each process.

FIG. 2 is a cross-sectional view of a plastic injection molding mold having a rapid cavity heating means according to an embodiment of the present invention, and FIG. 3 is a detailed view of a cavity rapid heating means, which is an essential part of the present invention.

As can be seen from the drawings, the basic structure of a mold according to an embodiment of the present invention is the same as that of a general mold previously described. Therefore, in the following description, the same reference numerals are used for the same parts as those of a general mold, and redundant descriptions will be omitted as much as possible, and a characteristic configuration of the present invention will be mainly described.

As shown, the fixed side mold 10 includes an upper support plate 11 and an upper plate 12. A groove portion 12a that is depressed to a predetermined depth is formed in the central portion of the upper disk 12, and a guide hole 12b is formed on one side thereof. In addition, the fixed side mold 10 is provided with a resin injection port, but the illustration is omitted in the drawings. The groove portion 12a of the upper plate 12 cooperates with the core 22a coupled to the lower plate 22 of the movable side mold 20 to form a cavity forming a space for product molding. This cavity is in communication with the resin injection port, and through the resin injection port, an appropriate amount of plastic

By injecting resin and filling the cavity, a product having a desired shape can be obtained.

The heat conductive layer 51 is coated on the groove 12a of the fixed side mold 10 constituting the cavity to form the cavity surface. In addition, a plurality of wire heaters 52 are disposed outside the heat conductive layer 51, that is, around the grooves 12a of the upper disk 12, to heat the heat conductive layer 51. Accordingly, the surface of the cavity can be rapidly heated, and thus the temperature of the cavity surface can be maintained at a temperature close to that of the high-temperature resin injected when the resin is filled. Due to this structure, there is almost no temperature difference between the resin injected into the cavity and the surface of the cavity when the resin is filled, and therefore, it is possible to suppress the appearance defect of the product due to a large temperature difference between the injected resin and the cavity surface.

As shown in FIG. 4, the wire heater 52 is controlled by a heating means controller 53, and the heating means controller 53 is connected to the main controller 70 of the injection machine, and is operated therefrom. It is supposed to receive a stop sign. Specifically, as shown in FIG. 5, the wire heater 52 is'on' when the mold is opened and starts to heat the cavity surface of the mold. And it is'off' when the filling of the resin is completed.

Reference numeral 54 in FIGS. 2 and 3 is an insulating material for inducing a direction of heat diffusion of the wire heater 52. As shown, the heat insulating material 54 is disposed behind each wire heater 52 to prevent the heat of the wire heater 52 from being diffused and induced in a direction other than the heat conductive layer 51, thereby more effectively cavities. Try to heat the surface.

Meanwhile, reference numeral 61 in FIGS. 2 and 3 denotes a cooling hole constituting the rapid cooling means for the cavity of the present invention. Low-temperature cooling water containing an antifreeze for rapid cooling is selectively supplied to the cooling hole 61, thereby cooling the molded product in the cavity. At this time, the cavity rapid cooling means including the cooling hole 61 rapidly cools the surface of the cavity heated by the wire heater 52, thereby facilitating the removal of the product.

The cavity rapid cooling means as described above includes a cooling hole 61, a cooling water supply source (not shown) for supplying cooling water circulating through the cooling hole 61, and a controller 63 for controlling the supply of cooling water, A pipe connecting the controller 63 and the cooling hole 61

A shut-off valve 64 is installed on the top. In addition, the cooling means controller 63 is connected to the main controller 70 of the injection molding machine, as shown in FIG. 4, and receives operation and stop signals therefrom. Specifically, as shown in FIG. 5, the cooling means is'on' and starts to cool when the filling of the resin is completed, that is, when the heating means is'off'. And when the mold is opened, it is'off', and at the same time, the heating means is'on' and starts to heat the cavity surface.

4 is a view showing an injection machine employing a mold having a rapid heating means for a cavity according to the present invention, in which reference numeral 100 denotes an injection machine body, 200 denotes a mold device, and 300 denotes a resin injection device.

Here, the main controller 70 controls the overall operation of the injection machine, and the heating means controller 53 and the cooling means controller 63 receive a signal from the main controller 70 and It controls the operation of the cooling means.

And, the accompanying Figure 5 is a view showing a molding process using a mold according to the present invention and a mold surface temperature in each process.

Hereinafter, the operation of the injection molding machine employing the mold of the present invention will be described with reference to the drawings.

Basic injection molding process, as shown in Figure 5, mold opening (S100), product take-out (S110), mold closed (S120), resin injection device advance (S130), injection (fill + maintenance) (140) resin injection Including the steps of retreating the device (S150), cooling (S160) and opening the mold (S170)

And repeat these steps. Here, the heating means controller 53 receiving the mold opening (S100) signal from the main controller 70 of the injection machine is a wire heater 52

Power is supplied to the device, and the mold from which the product is taken is closed (S120). Upon completion of the mold tightening, the surface temperature of the mold rises to about 95 to 100°C due to the continuous operation of the wire heater. Simultaneously with injection, the surface temperature of the cavity rises to 110~115℃ as it meets the hot plastic resin. That is, by heating the surface of the cavity with a wire heater, the temperature of the cavity surface can be maintained at a temperature close to that of the high-temperature resin.

In order to eliminate the deep world-line of the product, the heating means controller 53 receiving the injection start (filling + holding pressure: S140) signal

After filling, the wire heater is turned off after a relay time of several seconds after filling to induce thermal diffusion of the plastic resin side.

At the same time as the wire heater is turned off, the cooling means controller 63 starts supplying the cooling water to the cooling hole, thereby rapidly cooling the cavity surface. The above rapid cooling means stops its operation by a separate timer, and receives a mold open signal after cooling is completed.

At the same time, the heating means controller starts to supply power to the wire heater.

In the basic injection molding process as described above, the cavity rapid heating means and the cooling means work together to complete one cycle of product molding.

10; Fixed side mold 11; Upper support plate
12; upper plate 12a; groove
20; movable side mold 21; base plate
22; lower plate 22a; core
23; Supporter 30; Mild plate
31; Milfin 40; Molded product
51; heat conductive layer 52; wire heater
53; heating means controller 54; insulation
61; cooling hole 63; cooling means controller
70; main controller 100; injection machine body
200; mold device 300; resin injection device

Claims (5)

A plastic injection molding mold in which a product is molded by filling a cavity formed by a combination of a fixed-side mold and a movable-side mold, and the molded product is taken out by separating the movable-side mold, wherein the resin into the cavity A cavity rapid heating means for rapidly heating the surface of the cavity at the moment when the resin is injected during filling, and a cavity rapid cooling means for rapidly cooling the surface of the cavity by operating upon completion of resin filling, wherein the cavity rapid heating means is fixed. A heating element disposed at a certain distance along the edge of the cavity of the side mold, and a heat conductive layer that is coated on the surface of the cavity so that the heat of the heating element is spread evenly over the entire surface of the cavity, and forms a contact surface with the resin to be actually filled, And a controller for controlling the operation of the heating element;
The heating element operates from the point when the movable-side mold is separated from the fixed-side mold until the filling of the resin is completed, whereby the surface temperature of the cavity is maintained at a high temperature close to the temperature of the resin while the plastic resin is being filled. , Plastic injection molding mold, characterized in that it is possible to suppress the appearance quantity of the product to be molded. The plastic injection molding mold according to claim 1, wherein a heat insulator for guiding the heat diffusion direction of the heating element is disposed at a rear portion of each heating element so that heat from the heating element is not diffused to a portion other than the heat conduction. The plastic injection molding mold according to claim 1 or 3, wherein the heating element is a wire heater. The apparatus of claim 1, wherein the cavity rapid cooling means comprises: a plurality of cooling holes formed by maintaining a predetermined distance around the cavity of the fixed side mold;
A cooling water supply source supplying cooling water circulating along the cooling hole; And
It includes a controller for controlling the supply of cooling water, m The cooling water is supplied for a predetermined curing time from the time when filling of the resin is completed, and the supply is stopped at the time when the movable side mold is separated for product extraction. Plastic injection molding mould. Injection machine main body;
A mold apparatus having a fixed side mold and a movable side mold movable with respect to the fixed side mold, installed on one side of the main body, and forming a cavity for product molding by combining the fixed side mold and the movable side mold , A resin injection device for filling the plastic resin into the cavity of the mold device;
Means for rapidly heating the surface of the cavity when the resin is filled into the cavity by the resin injection device, means for rapidly cooling the surface of the cavity by operating upon completion of the resin filling into the cavity by the resin injection device;
A main controller for controlling the operation of the mold device and the resin injection device;
A heating means controller that receives a signal from the main controller and controls the operation of the rapid cavity heating means of the mold apparatus; And
A plastic injection machine comprising a cooling means controller for receiving a signal from the main controller and controlling the operation of the rapid cavity cooling means of the mold apparatus.

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