JP2022011427A - Molding mold member - Google Patents

Abstract

To provide a molding mold component capable of appropriately removing heat from a molded product in a molding mold for molding a container lid made of synthetic resin.SOLUTION: The inventive molding mold component is a molding mold member that consists of a male mold and a female mold that are integrally 3D-formed by sintering metal powder with laser light, and into which a molten resin for molding a sealing body in which a thread is formed and a container is sealed flows in. The molding mold component includes: a thread groove convex part 10 for forming the thread of the sealing body formed on either the male mold or the female mold; and a cooling flow path part 20 that is disposed inside the thread groove convex part 10 and through which a cooling medium is circulated to cool the thread so as to face it along a flank of the thread.SELECTED DRAWING: Figure 4

Description

The present invention relates to, for example, a molding die member for molding a heat-melted synthetic resin container lid.

Conventionally, a synthetic resin container lid made of a synthetic resin material such as polyethylene or polypropylene, which is used for sealing a container, for example, has been known. As shown in Patent Document 1, for example, such a synthetic resin container lid is mass-produced by a molding die generally used for injection molding, compression molding, or the like.

The mold used for such molding is generally manufactured by cutting, but in recent years, it has been proposed to manufacture the mold by three-dimensional modeling using a so-called 3D printer.

For example, in Patent Document 2, by utilizing 3D modeling of a metal mold using metal powder and forming a temperature control circuit at the same time as mold molding by laser light, temperature control is performed by machining after mold molding. It has been proposed that there are no restrictions on machining as compared with conventional metal molds provided with circuits, and the degree of freedom in designing temperature control circuits is improved.

Further, for example, in Patent Document 3, when a resin molding mold for three-dimensionally molding a photocurable resin is manufactured using a three-dimensional printing device, the cooling tube through which the cooling medium for cooling the molding mold flows is a molded product and a molding mold. It is proposed that the contact surface bends along the contact surface and the area of the contact surface is set to a distance of 60% or more from the cooling pipe within 8 mm.

Japanese Unexamined Patent Publication No. 1-235615 Jikkenhei 11-34845 Gazette Japanese Unexamined Patent Publication No. 2017-124592

Certainly, if the molding die is integrally manufactured using the above-mentioned three-dimensional printing device, it is possible to simultaneously manufacture the cooling flow path and the like in accordance with the shape of the molded product.
By the way, when the synthetic resin container lid described above is screwed with respect to the mouth of the container, a thread is formed inside the skirt wall. Here, the diameter of the container lid is about 20 to 30 mm, and the above-mentioned screw thread is also relatively small, but if the heat removal after molding becomes excessive, the molded product may be damaged during mold release. If the above-mentioned heat removal is insufficient, the molded product will be deformed.

In other words, it is important to remove heat from an appropriate molded product in a molding die for molding a synthetic resin container lid, but the prior art including the above-mentioned patent document has not reached the problem described later. It is hard to say that it still meets the needs of the market.
Therefore, one of the objects of the present invention is to provide a molding die component capable of appropriately removing heat from a molded product in a molding die for molding a synthetic resin container lid.

In order to solve the above problems, the molding mold component in one embodiment of the present invention is composed of (1) a male mold and a female mold integrally formed by sintering metal powder with a laser beam and integrally formed with a screw. A molding mold member used for a forming mold into which a molten resin for forming a sealing body in which a pile is formed and a sealing body for sealing a container flows, and is used in either the male mold or the female mold. The formed convex portion for a thread groove for forming a thread of the sealing body and the convex portion for the thread groove are arranged inside the convex portion and cooled so as to face each other along the flank of the thread. It is characterized by having a cooling flow path portion through which a cooling medium is circulated.

In the molding die component according to (1) above, (2) the cooling flow path portion is formed continuously along the flank in the circumferential direction and continuously in the vertical axis direction of the screw thread. It is preferable to be.

Further, in the molding die component according to the above (1) or (2), (3) the cooling medium is discharged from the inlet port into which the cooling medium for cooling the molten resin flows into the cooling flow path portion. It is preferable that the flow path is spiral without branching to the outlet port.

Further, in the molding die component according to any one of (1) to (3), (4) the sealing body is a cap screwed into the mouth of the container, and the male mold. The inner surface of the top wall in the cap, the inner surface of the skirt wall hanging from the top wall, and the thread formed on the inner surface of the skirt wall are defined by the female mold, respectively, and the outer surface of the top wall and the said It is preferable that the outer surface of the skirt wall is defined respectively.

Further, in the molding die component according to any one of (1) to (4), (5) the cooling flow path portion is the screw adjacent to each other in the vertical axis direction in the sealed body to be molded. It is preferably provided so that at least a part thereof is accommodated in the thread groove between the ridges.

According to the present invention, it is possible to realize a part for a molding die capable of suppressing damage or deformation of a synthetic resin container lid due to improper heat removal.

It is a front view which shows the appearance of the part for a molding die of an embodiment. It is an external perspective view of the part for a molding die of an embodiment. It is sectional drawing (the 1) which shows the structure of the refrigerant flow path in the part for a molding die of an embodiment. FIG. 2 is a cross-sectional view (No. 2) showing the structure of the refrigerant flow path in the molding die component of the embodiment. It is a schematic diagram which shows the molding die and the molded article including the molding die component of an embodiment, respectively. It is a schematic diagram which shows the molding die of the conventional structure as a comparative example.

Hereinafter, embodiments for preferably carrying out the present invention will be described. In the present embodiment, the X, Y, and Z directions are appropriately set in the explanation using figures for convenience of explanation, but the present invention is not excessively limited for convenience of explanation. Further, for a mechanism other than the configuration described in detail below, the structure of the molding die used for the known synthetic resin container lid including the above-mentioned Patent Document 1 may be appropriately applied.

[Molding mold 1000]
First, as shown in FIG. 5 and the like, the molding die 1000 in the present embodiment is composed of a male LDM (core) and a female UDM (cavity), each of which is integrally formed in 3D by sintering metal powder with a laser beam. It is configured.

A thread 3 is formed in such a molding die 1000 via a runner RN and a gate GT in the molding die 1000 to form a sealed body CAP for sealing a container (not shown). The molten resin flows in. As an example, in the present embodiment, the molten resin heated to about 150 ° C. to 200 ° C. is injected into the molding die 1000 and cooled by a known refrigerant (water or the like) of about 10 ° C. to 30 ° C. To.

The resin material applicable in this embodiment is not particularly limited as long as it is a meltable resin used for injection molding or compression molding, and a known synthetic resin material such as polypropylene or polyethylene can be applied. Further, in the present embodiment, injection molding will be described as an application example of the molding die, but the present invention can also be applied to other molding methods such as the above-mentioned compression molding and extrusion molding.

More specifically, the molding die 1000 in the present embodiment is a molding die component 100 as a screw core inserted inside the molded product (sealed body CAP), and the top wall of the molded product (sealed body CAP). And the cavity 200 in contact with the outside of the skirt wall, the stripper bushing 300 used for so-called forcible removal, the cooling core 400 in which one of the refrigerant flow paths CW is formed, and the cooling inserted into the cooling core 400 to control the flow of the refrigerant. It is configured to include a bar 500 and the like.

[Parts for molding dies 100]
As shown in FIGS. 1 to 4, the molding die component 100 of the present embodiment can be incorporated into the molding die 1000 described above, and has a thread groove convex portion 10, a thread groove portion 11, and an intermittent wall. 12, TE forming portion 13, end forming portion 14, and cooling flow path portion 20 are included.
The molding die component 100 of the present embodiment is integrally manufactured by using the above-mentioned known three-dimensional modeling apparatus such as a so-called 3D printer. Further, the material of the molding die component 100 of the present embodiment is not particularly limited, and various known metal powders capable of three-dimensional modeling can be applied.

The thread groove convex portion 10 is used to form the thread 3 of the sealing body CAP described above. The thread groove can be formed in either a male type or a female type depending on the form of the sealing body CAP. Therefore, the convex portion 10 for the thread groove of the present embodiment is formed in either a male type or a female type in accordance with the above. The threaded groove 10 is formed on the sealed body CAP after molding.

As the sealed body CAP in the present embodiment, a synthetic resin cap screwed into the mouth of a known container such as a PET bottle is suitable. However, the sealing body CAP suitable for the present invention is not limited to the above-mentioned container lid (cap) as long as it has a screw structure, and is another known sealing member having a screw structure such as a spout. May be good.

In the present embodiment, the sealing body CAP is a cap screwed to the mouth of the container as described above (see also FIG. 5 (b) as appropriate), and the cap is heavenly by the above-mentioned male LDM. Threads 3 formed on the inner surface of the face wall 1, the inner surface of the skirt wall 2 hanging from the top wall 1, and the inner surface of the skirt wall 2 are defined. Similarly, as shown in the figure, the outer surface of the top wall 1 and the outer surface of the skirt wall 2 are defined by the female UDM described above, respectively.

As can be understood from FIGS. 1 and 2, the thread groove portion 11 is for a thread groove in the vertical axis direction (Z direction) so that the spiral thread 3 is formed in the sealed body CAP after molding. It is arranged above and below the convex portion 10.

The intermittent wall 12 is arranged with a predetermined gap in the circumferential direction so that the thread 3 and the thread groove of the sealing body CAP described above are intermittent along the circumferential direction (θz direction). When the thread 3 of the sealing body CAP has a continuous spiral shape, such an intermittent wall 12 is omitted.

The TE forming portion 13 is a groove portion for forming a tamper evidence indicating that the sealed body CAP after molding has been opened. The structure of such a tamper evidence is not particularly limited, and a known tamper evidence structure can be applied.

The end forming portion 14 is a portion where the lower end of the sealed body CAP after molding is located. In the molding die component 100 of the present embodiment, as an example, the lower side of the end forming portion 14 as a boundary has a tapered shape whose diameter is gradually increased.

The cooling flow path portion 20 is arranged inside the screw groove convex portion 10 described above, and is formed along the flank f of the thread 3 of the CAP shown in FIG. 5 (b). A cooling medium for cooling along the flank f of the mountain 3 so as to face each other is distributed. As the cooling medium of the present embodiment, for example, a known liquid or gas such as water whose temperature has been adjusted as described above can be applied.

As shown in FIG. 5, the cooling flow path portion 20 of the present embodiment is composed of three cooling flow paths, a first cooling flow path CW ₁ , a second cooling flow path CW ₂ , and a third cooling flow path CW ₃ . ing. Of these, the first cooling flow path CW ₁ is disposed on the cavity 200 side described above, and is responsible for cooling the molten resin toward the outer peripheral surface of the skirt wall 2 of the sealing body CAP.

Further, the second cooling flow path CW ₂ constituting the cooling flow path portion 20 of the present embodiment is arranged inside the above-mentioned thread groove convex portion 10 and is formed into a thread 3 of the sealing body CAP. The cooling medium circulates so as to face each other along the flank f of.
Further, the remaining third cooling flow path CW ₃ constituting the cooling flow path portion 20 is arranged in the cooling core 400 described above, and is arranged inside the skirt wall 2 of the sealing body CAP (for example, the inner ring 4 or the outer). It is responsible for cooling the molten resin toward the ring 5 or the inner surface of the top wall 1).

In the present embodiment, the cooling flow path portion 20 is configured by the above-mentioned total of three cooling flow paths, but the present invention is not limited to this example, and is single as long as at least the second cooling flow path CW ₂ is arranged. It may be a flow path of the above, or may be a form composed of two or four or more flow paths.

Further, as can be understood from FIGS. 3 and 4, the cooling flow path portion 20 in the present embodiment is continuous in the circumferential direction along the slope (frank f) of the thread 3 of the sealed body CAP and the screw. It is preferable that the mountain 3 is formed so as to be continuous with respect to the vertical axis direction (Z direction in the figure). As a result, the cooling flow path portion 20 can be arranged close to the flank f of the screw thread 3 where proper heat removal is difficult, and necessary and sufficient heat removal from the molten resin after molding can be realized. ..

Further, as shown in FIG. 5A, a cooling medium (cooling water or the like) for cooling the molten resin flows in at least in the second cooling flow path CW ₂ of the cooling flow path portions 20 of the present embodiment. It is preferable that the flow path is a spiral without branching from the inlet port CW _2IN to the outlet port CW _2OUT from which the cooling medium is discharged. As a result, proper heat removal of the sealed body CAP can be efficiently realized without complicating the device configuration.

Further, as shown in FIGS. 3 and 4, the cooling flow path portion 20 (second cooling flow path CW ₂ ) of the present embodiment is the sealed body CAP from the viewpoint of the molded sealed body CAP. It can be said that it is preferable that at least a part thereof is accommodated in the thread groove between the adjacent threads 3 in the vertical axis direction (Z direction in the drawing). As a result, one cooling flow path can be efficiently assigned to the slope (frank f) on both of the adjacent threads 3.

As shown in FIG. 4, in the present embodiment, the distance R3 from the bottom of the thread groove portion 11 (the portion that becomes the top of the thread 3 of the sealing body CAP) to the central axis O is the second cooling flow path. It is also larger than the distance R1 to the central axis O of the refrigerant flow path located on the outermost peripheral side in CW ₂ . However, the present embodiment is not limited to the above, and may be set to, for example, R1 = R3 or R1> R3. At this time, when R1 ≧ R3, the thread 3 (particularly the flank f portion) of the sealing body CAP can be cooled more efficiently.

<Advantages over conventional mold structure>
As described above, although the technique of three-dimensional molding using metal powder or resin powder has been known, in the field of manufacturing a sealed body CAP, a molding die formed by cutting / grinding as shown in FIG. 6 is performed. Is often used. In this case, for example, when the sealing body CAP is a cap or a spout, the flow path arranged in the mold is relatively small, so that the molded part is processed by a plurality of pieces such as two pieces.

Since the molded part is composed of a plurality of pieces as described above, a special packing P (see FIG. 6 as an example) is particularly required to prevent liquid leakage from the refrigerant flow path. However, as described above, since the diameter of the flow path arranged in the mold is small, such packing is also custom-made and causes an increase in cost.

Further, as can be understood from FIG. 6, it is not easy to bring the conventional refrigerant flow path close to the vicinity of the thread 3 of the sealing body CAP in order to maintain the strength of the mold, and it is relative from the top of the thread 3. I had no choice but to place it in a position separated from it. Therefore, compared to the molding die 1000 (see FIG. 5) of the present embodiment, the temperature of the molten resin must be controlled by a cooling medium from a position farther from the thread 3, especially up to the flank f of the thread 3. It could not be said that the cooling was sufficient.

On the other hand, according to the molding die component 100 of the present embodiment, a cooling medium disposed inside the thread groove convex portion 10 and cooling along the flank f of the thread 3 so as to face each other is distributed. Since the cooling flow path portion 20 is provided, the molten resin injected into the molding die maintains elasticity to the extent that it can withstand the above-mentioned forcible removal, and also suppresses deformation due to insufficient heat removal. It is possible to do.

That is, in the field of molding of the sealed body CAP, severe temperature control that neither supercooling nor insufficient cooling is allowed is required, but according to this embodiment, the synthetic resin container lid is damaged or deformed due to improper heat removal. It is possible to realize a part for a molding die that can suppress the above. Further, according to the present embodiment, since the integrated molding can be performed by using the three-dimensional molding technology as described above, the cost required for mold manufacturing can be reduced and the liquid leaks due to the expensive packing. No preventive measures are required.

The above embodiment is a suitable example for carrying out the present invention, and is used for a new molding die or a molding die by appropriately modifying or combining each element of the embodiment as long as it does not deviate from the gist of the present application. Parts may be configured.

For example, as shown in FIG. 4, each distance R from the central axis O of the cooling flow path portions 20 (second cooling flow path CW ₂ ) arranged a plurality along the vertical axis direction (Z direction) is the present implementation. The morphology is uniform, but they may be different from each other. More specifically, for example, the distance R2 from the central axis O of the cooling flow path portion 20 on the side relatively close to the top surface wall 1 of the sealing body CAP is the cooling flow path portion on the side relatively far from the top surface wall 1. It may be set larger than the distance R1 from the central axis O of 20.

Further, as shown in the figure, the hole diameters of the respective flow paths of the cooling flow path portions 20 (second cooling flow path CW ₂ ) arranged a plurality along the vertical axis direction (Z direction) are set in the present embodiment. It is uniform but may be different from each other. More specifically, for example, the hole diameter (diameter) of the cooling flow path portion 20 on the side relatively close to the top surface wall 1 of the sealing body CAP is the hole diameter (diameter) of the cooling flow path portion 20 on the side relatively far from the top surface wall 1. It may be set larger than (diameter). As a result, the cooling efficiency at the portion of the sealed body CAP that becomes the top wall 1 can be further improved.

Further, as shown in the figure, the shape of each of the plurality of cooling flow paths 20 (second cooling flow path CW ₂ ) arranged along the vertical axis direction (Z direction) is the shape of each flow path in the present embodiment. Although the round holes are uniform along the circumferential direction, the cooling flow path portion 20 may have a circular or non-circular cross-sectional shape. Further, the shape of the spiral flow path in the second cooling flow path CW ₂ differs depending on the position in the circumferential direction (for example, the cross-sectional shape of a part of the flow path in the circumferential direction is circular and the other portion. May be rectangular, etc.).

Further, in the present embodiment, the cooling flow path portion 20 (second cooling flow path CW ₂ ) is a spiral flow path that does not branch from the inlet port CW _2IN to the outlet port CW _2OUT , but is not necessarily spiral. It does not have to be a shape. That is, for example, a plurality of annular cooling channels are provided corresponding to the threads 3 of the sealing body CAP, and the annular cooling channels adjacent to each other in the vertical axis direction (Z direction) are connected to each other along the vertical axis direction. Further channels may be formed. Further, the second cooling flow path CW ₂ does not necessarily branch and does not necessarily have to be a single flow path. For example, the annular cooling flow paths are made independent of each other corresponding to the thread 3 of the sealing body CAP. Only a plurality may be provided.

INDUSTRIAL APPLICABILITY The present invention is suitable for providing a part for a molding die having excellent heat removing properties in a molding die for molding a molded product having a thread.

1000: Molding mold 100: Molding mold parts 10: Convex part for thread groove 11: Groove part for thread thread 12: Intermittent wall 13: TE forming part 14: End forming part 20: Cooling flow path part CW ₁ : No. 1 cooling flow path CW ₂ : 2nd cooling flow path CW ₃ : 3rd cooling flow path 200: cavity 300: stripper bushing 400: cooling core 500: cooling bar

Claims (5)

It consists of a male mold and a female mold that are integrally molded in 3D by sintering metal powder with laser light, and a molten resin for forming a sealing body that forms a screw thread and seals a container flows in. A member for a molding die used for a molding die.
A thread groove convex portion formed on either the male mold or the female mold for forming a thread of the sealed body, and
A cooling flow path portion that is disposed inside the convex portion for the thread groove and through which a cooling medium for cooling along the flank of the thread thread is circulated.
A member for a molding die, characterized by having. The molding die member according to claim 1, wherein the cooling flow path portion is formed continuously along the flank in the circumferential direction and continuously in the vertical axis direction of the screw thread. The cooling flow path portion is a spiral flow path that does not branch from the inlet port into which the cooling medium for cooling the molten resin flows to the outlet port from which the cooling medium is discharged, according to claim 1 or 2. The described molding die member. The sealant is a cap that is screwed into the mouth of the container.
The male mold defines the threads formed on the inner surface of the top wall of the cap, the inner surface of the skirt wall hanging from the top wall, and the inner surface of the skirt wall.
The molding die member according to any one of claims 1 to 3, wherein the outer surface of the top wall and the outer surface of the skirt wall are defined by the female mold. Claims 1 to 4 are provided such that the cooling flow path portion is provided so that at least a part of the cooling flow path portion is accommodated in a thread groove between the threads adjacent to each other in the vertical axis direction in the sealed body to be molded. The member for a molding die according to any one of the above items.

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