JP2003053813A - Mold and method for cooling mold - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve an efficiency of cooling with a simpler constitution than a prior art by applying, for example, to injection molding. SOLUTION: A method for cooling a mold comprises the steps of supplying a cold air to a cooling tube 15 formed in the mold 1B, and cooling the mold 1B.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold and a mold cooling method, and can be applied to, for example, injection molding. INDUSTRIAL APPLICABILITY According to the present invention, cooling air is introduced into a cooling pipe formed in a mold to cool the mold, so that the cooling efficiency can be improved with a simpler structure than the conventional one.

[0002]

2. Description of the Related Art Conventionally, in a mold used for plastic molding, die-cast molding, etc., a molding material is molded into a cavity shape, and the high temperature material thus molded is cooled to a temperature at which the shape does not change. In these moldings, the productivity can be improved by shortening the time required for this cooling.

For this reason, conventionally, in this type of manufacturing process, a liquid cooling medium such as cooling water or oil is circulated in a cooling pipe formed in a mold and cooled by heat conduction by the cooling medium. It is done like this.

[0004]

By the way, in this type of mold, if the cooling efficiency can be improved, the productivity can be improved accordingly. Therefore, in the conventional liquid-cooled mold, it is considered that the cooling efficiency can be improved and the productivity can be improved by making the cooling pipe close to the cavity. However, in the conventional liquid-cooled mold, if the cooling pipe is formed close to the cavity, it is difficult to secure sufficient strength.

That is, in the conventional liquid-cooled mold, it is necessary to set the inner diameter of the cooling pipe to 6 [mm] or more, which allows 10 [mm] from the surface of the cavity.
It is difficult to secure sufficient strength unless the cooling pipes are arranged in the recessed position with sufficient space between the adjacent cooling pipes.

In the conventional liquid-cooled mold, there is a problem that the molded product becomes defective due to the leakage of the cooling medium and the mold is corroded. For this reason, in the conventional liquid-cooled mold, it is necessary to strictly configure the flow path of the cooling medium so that the cooling medium does not leak.

The present invention has been made in consideration of the above points, and it is an object of the present invention to propose a mold and a mold cooling method capable of improving the cooling efficiency with a simpler structure than the conventional one. It is a thing.

[0008]

In order to solve such a problem, in the invention of claim 1, the invention is applied to a molding die so that a cooling pipe for guiding cold air is formed.

According to the second aspect of the present invention, it is applied to a mold cooling method, in which cool air is introduced into a cooling pipe formed in the mold to cool the mold.

According to the first aspect of the present invention, the cooling pipe for guiding the cool air is formed by being applied to the molding die, and the cooling pipe for guiding the cool air has a cooling pipe, as compared with the case of liquid cooling. The small diameter allows the refrigerant to flow efficiently, so that the refrigerant can be densely arranged close to the cavity. Thereby, the cooling efficiency can be improved as compared with the conventional case. Further, in such cooling by the cold air, even if the refrigerant leaks, it is possible to prevent the molded product, the mold, and the like from being affected, and thus it is possible to create the flow path with a simple configuration.

Thus, according to the second aspect of the invention, the method is applied to the cooling method of the die, and cool air is introduced into the cooling pipe formed in the die to cool the die. With a simple structure, the cooling efficiency can be improved.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below in detail with reference to the drawings as appropriate.

(1) Configuration of Embodiment FIG. 2 is a plan view for explaining a mold according to an embodiment of the present invention. The mold 1 includes a fixed side mounting plate 3 and a movable plate 4 arranged on a frame F of the injection molding machine 2.
Are fixed via the plates 3A and 4A, respectively.

Here, at the four corners of the fixed side mounting board 3, divers are horizontally mounted between them and a movable side mounting board (not shown), and the movable board 4 is slidably held by the divers. The movable platen 4 is fixed along the diver by the mold clamping mechanism arranged on the movable platen side.
The mold 1 is moved to the side so that the mold 1 can be clamped, and the mold can be opened by moving in the opposite direction. On the other hand, the fixed side mounting board 3 is
An injection device 6 is arranged on the side opposite to the mold 1, and the injection device 6 can inject the molding material into the cavity of the mold 1.

The mold 1 has a so-called three-plate structure including a core plate 1A, a cavity plate 1B and a spool plate 1C. Here, in the mold 1, as shown in FIG.
The guide pins 7 are arranged at the four corners of the core plate 1A, and the cavity plate 1B is slidable on the guide pins 7.
Is held, and the guide pin 7 is attached to the spool plate 1C.
A recess for receiving is formed. A lock pin P is arranged on the cavity plate 1B.
Engages with the recess of the spool plate 1C. As a result, the mold 1 can prevent the positional displacement of the cavity plate 1B in the vertical and horizontal directions and can repeat the molding operation.

However, even if the cavity plate 1B is held and positioned by the guide pin 7 and the lock pin P as described above, in the mold 1, the guide pin 7 is gradually deformed by the weight of the cavity plate 1B. As a result, the precision of the molded product deteriorates, and an accident such as galling of the mold occurs. Therefore, in the conventional manufacturing process, periodical maintenance of the mold 1 is required.

Therefore, in this embodiment, in the injection molding machine 2, the holding mechanism 8 is arranged on the frame F, and the mold 1 is
The holding mechanism 8 causes the cavity plate 1B to
Is supported from below. That is, the holding mechanism 8 is configured to support the cavity plate 1B by the table 10, and is arranged on the frame F so that the table 10 can be moved up and down by a predetermined height adjusting mechanism 9.
Here, the height adjustment mechanism 9 is, for example, a hydraulic jack,
The injection molding machine 2 is configured to support the dies 1 of various sizes by adjusting the height of the table 10 by the height adjusting mechanism 9 in this injection molding machine 2. There is.

A slide rail 11 is arranged on the upper end surface of the table 10, and the cavity plate 1B is supported via the slide rail 11. Thus, in the injection molding machine 2, the cavity plate 1B is supported without restricting the movement of the cavity plate 1B, and even if the mold clamping and the mold opening are repeated, the guide pin 7 is remarkably different from the conventional one. It is designed to reduce the deformation of the. It should be noted that if the deformation of the guide pin 7 can be reduced in this way, the number of regular maintenance can be reduced accordingly. In addition, it is possible to produce a highly accurate molded product even if the number of such maintenance is reduced, and further prevent accidents due to scoring of the guide pin 7 and the lock pin P, thereby significantly increasing the service life of the mold. Can be increased.

The mold 1 is thus held by the injection molding machine 2 and cooled by the cold air generated by the cold air generator 13. Here, the cold air generation device 13 is a device that creates cold air of about −30 degrees by compressing and processing the gas, and in this embodiment, air is applied to this gas.

In the mold 1, cooling pipes for air cooling are formed in each of the core plate 1A, the cavity plate 1B, and the spool plate 1C, and the cold air generated by the cold air generator 13 constantly circulates in these cooling pipes. Thus, the cooling efficiency can be improved with a simpler structure than the conventional one.

That is, FIG. 1 is a perspective view showing a cavity plate 1B of the mold 1 with a partial cross section.
The mold 1 includes a core plate 1A and a spool plate 1
Since C has the same configuration, only the cavity plate 1B will be described below,
A duplicate description will be omitted. Further, in FIG. 1, description of the through holes and the like for receiving the guide pins is omitted.

In the cavity plate 1B, the cooling pipe 15 having a smaller diameter than that of the cooling pipe for water cooling indicated by a broken line is arranged at a position closer to the cavity than the arrangement position of the cooling pipe for water cooling. . Further, these cooling pipes 15 are arranged closer to each other as compared with the case where a conventional cooling pipe for water cooling is arranged. As a result, in the die 1, the cooling efficiency can be improved with a simpler structure.

In these molds 1, a cooling pipe 15 is formed so as to linearly penetrate between the upper side surface and the lower side surface, and the core plate 1A, the cavity plate 1B and the spool plate 1C each have a flexible pipe. The adjacent cooling pipes 15 are connected to each other, and are further connected to the cool air generating device 13, respectively, so that the flow path of the refrigerant is formed by these.

Further, as shown in FIG. 4, in the mold 1, a so-called spiral is arranged in each cooling pipe 15. Here, the spiral is a turbulent flow generation mechanism in which a turbulent flow is generated in the refrigerant flowing inside each cooling pipe 15. In this embodiment, as shown in FIG. 4, blades are arranged at regular intervals. Is applied to each cooling pipe 1
5 are arranged.

(2) Operation of the Embodiment With the above-mentioned configuration, in this injection molding machine 2 (FIG. 2),
The fixed side mounting board 3 and the movable board 4 have plates 3 respectively.
The mold 1 is fixed via A and 4A, and the movable platen 4 is moved by the mold clamping mechanism to clamp the mold, and the molten resin material is injected from the injection device 6 into the cavity of the mold 1 for molding. The process is executed. Further, in the injection molding machine 2, this state is maintained for a certain period of time to perform cooling processing, and then the movable platen 4 is moved by the mold clamping mechanism to open the mold, and then the molded product is taken out from the mold 1. In the injection molding machine 2, this series of processes is repeated to sequentially produce injection molded products.

In injection molding, the time required for this cooling process is relatively long as compared with other processes, and if the molding product in the cavity can be cooled efficiently in the mold 1, The productivity is remarkably improved.

In the mold 1, the cold air generated by the cold air generator 13 flows inside the cooling pipes 15 (FIG. 1) formed in the core plate 1A, the cavity plate 1B, and the spool plate 1C, respectively. As a result, instead of liquid cooling in the conventional mold, cooling is performed by cold air. Here, in the case of cooling with cold air, the flow resistance of the refrigerant is small as compared with the case of liquid cooling,
Even if the inner diameter of the cooling pipe is reduced, the refrigerant can be circulated without hindering the circulation of the refrigerant.

As a result, in the mold 1, the cooling pipe 15 is formed to have a smaller diameter than in the case of liquid cooling. If such a cooling pipe 15 is formed to have a small diameter, it can be arranged closer to the cavity as compared with the case of liquid cooling, and even closer to the case of liquid cooling. However, the strength of the mold 1 can be sufficiently ensured. Thereby, in the mold 1, the cooling pipe 15 is arranged close to and close to the cavity, so that the strength of the mold 1 is sufficiently secured and the mold 1 can be cooled efficiently. Has been done.

Further, in the mold 1, a turbulent flow generating mechanism is provided inside the cooling pipe 15 (FIG. 4), whereby turbulent flow is generated in the cool air flowing inside, and when the cool air is caused to flow by the laminar flow. In comparison, the cooling efficiency is improved.

In this way, in the cooling by such cold air, even if the cold air leaks, there is no problem such as making the molded product defective and corroding the mold as in the case of liquid cooling. There are features. As a result, the flow path of the refrigerant can be created with a simpler structure than the conventional one, and the structure of the mold 1 can be simplified accordingly.

In particular, in the case of water cooling, since the cooling pipe must be formed by processing the mold with a drill machine or the like, the cooling pipe can be formed only in a straight line. When the cooling pipe is formed by cold air as described above, even if the cooling pipe 15 is formed by the groove processing by the split mold, it is possible to effectively avoid an accident due to liquid leakage or the like, and thus the cooling pipe is formed by a curved line. The cooling efficiency can be improved by various measures such as the above. In addition, the structure of the connecting portion between the cooling pipe and the pipe or the like for guiding the refrigerant to the cooling pipe can be simplified.

When the mold is opened and the mold is clamped repeatedly in this way, in the mold 1 (FIG. 3), the guide pin 7 is gradually deformed by the weight of the cavity plate 1B so that the guide pin 7 is flexed. Accuracy will deteriorate, and accidents such as galling of the mold will occur. Therefore, in the manufacturing process, regular maintenance of the mold 1 is required.

However, in this embodiment,
The cavity plate 1B is movably supported by the holding mechanism 8 from the lower side, which prevents the guide pin 7 from being deformed due to the weight of the cavity plate 1B. Therefore, the deformation of the guide pin 7 can be significantly reduced. As a result, the injection molding machine 2 can reduce the frequency of regular maintenance, and can produce a highly accurate molded product even if the frequency of such maintenance is reduced. 7. Accidents due to galling of the lock pin P can be prevented, and the service life of the mold can be significantly increased.

(3) Effects of the Embodiments According to the above-described structure, the cool air is introduced into the cooling pipe formed in the mold to cool the mold, so that the structure is simpler than the conventional one. The cooling efficiency can be improved.

(4) Other Embodiments In the above-mentioned embodiments, the case where the cooling pipe is formed in a straight line has been described, but the present invention is not limited to this.
The present invention can be widely applied to various cooling pipes, such as a curved line.

Further, in the above-mentioned embodiment, the case where the cooling pipe is connected to the outside by the pipe has been described.
The present invention is not limited to this, and the connection may be made inside the mold. In this case, as shown in FIG. 5, cooling pipes are formed so as to intersect inside the mold, and the cooling pipes are partially sealed with a metal material such as copper, and adjacent cooling pipes are You may make it connect.

Further, in the above-mentioned embodiment, the case where the cooling pipe by the cool air is provided in the mold has been described, but the present invention is not limited to this, and the cooling pipe by the liquid cooling may be additionally provided. In this case, it is conceivable that cooling by liquid cooling and cooling by cold air are combined, and further, a cooling pipe by cooling air is newly provided in a conventional mold for liquid cooling.

In the above embodiment, the case where air is used as the cold air has been described, but the present invention is not limited to this, and various cold air such as carbon dioxide gas and nitrogen gas may be used as the refrigerant. The effect of can be obtained.

Further, in the above-mentioned embodiments, the case where the present invention is applied to the injection molding of the resin material has been described, but the present invention is not limited to this, and can be widely applied to die cast molding and the like. It can be widely applied to sand molds instead of metal molds.

[0040]

As described above, according to the present invention, the cooling air is introduced into the cooling pipe formed in the mold to cool the mold, so that the cooling can be performed with a simpler structure than the conventional one. The efficiency can be improved.

[Brief description of drawings]

FIG. 1 is a perspective view showing a mold according to an embodiment of the present invention.

FIG. 2 is a plan view showing a part of an injection molding device using the mold of FIG.

FIG. 3 is a perspective view showing a state where the mold of FIG. 1 is opened.

FIG. 4 is a perspective view showing a turbulent flow generation mechanism.

FIG. 5 is a cross-sectional view showing a mold according to another embodiment.

[Explanation of symbols] 1 ... Mold, 2 ... Injection molding machine, 6 ... Molding device, 8 ...
… Holding mechanism, 15 …… Cooling tube

Claims (2)

[Claims] 1. A molding die, comprising: A mold characterized in that a cooling pipe for guiding cold air is formed. 2. A method for cooling a mold, wherein cool air is introduced into a cooling pipe formed in the mold to cool the mold.