JP2002326255A - Injection mold and injection molding machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the generation of molding defectiveness by suppressing the lowering in the flowability of a resin while preventing the deformation of a case such as a battery lid or the like arranged in a mold. SOLUTION: The injection mold 1 has a case 2 arranged in the cavity formed therein and is used in order to fill the gap between the case 2 and the loaded part 3 arranged inside the case 2 with a molten resin. This injection mold 1 is equipped with the groove 13 opened to the cavity at the position covered with the case 2 and both of the cooling medium supply port 15 and the cooling medium discharge port 16 communicating with the groove 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an injection molding die and an injection molding apparatus, and more particularly to a method for arranging components such as a battery in a case and filling a resin between them to integrate them. The present invention relates to an injection molding die and an injection molding apparatus.

[0002]

2. Description of the Related Art For example, as disclosed in Japanese Patent Application Laid-Open No. 2000-315483, a battery for a portable terminal such as a portable telephone or a PHS (simplified portable telephone) is provided on the inner surface of a battery cover of the portable terminal. Is arranged, and a resin is filled and cured between the inner surface of the battery lid and the battery cell, so that the battery lid and the battery cell are integrally connected with the resin.

[0003] In order to manufacture such a battery, a mold having an upper mold and a lower mold is used, and a battery cover formed of resin in advance is disposed in a recess formed in the lower mold. After placing the battery cells inside the mold, the upper mold and the lower mold are combined with each other and clamped, and the molten resin is injected into the mold cavity through the gate formed on the dividing line between the upper mold and the lower mold. inject. The molten resin injected into the cavity flows and fills a space defined between the battery lid, the battery cell, and the cavity surface of the mold in the mold, and is cured after a predetermined time has elapsed. Thereafter, the mold is opened and ejected to manufacture a battery in which the battery lid and the battery cell are integrated.

[0004]

However, since the molten resin injected into the cavity needs to reach every corner of the space defined in the cavity, it must be kept at a relatively high temperature in order to increase its fluidity. Heated. Therefore, the battery lid and the battery cells disposed in the cavity are in a high temperature state, and particularly, the battery lid made of resin may be overheated and deformed due to prolonged exposure to the high temperature state. On the other hand, if the resin temperature is lowered in order to prevent the deformation of the battery lid, there is a disadvantage that the fluidity of the resin in the cavity is reduced and molding failure occurs.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and it is possible to prevent a case such as a battery cover disposed in a mold from being deformed while suppressing a decrease in fluidity of a resin. It is an object of the present invention to provide an injection mold and an injection molding apparatus for a battery, which can prevent the occurrence of the phenomenon.

[0006]

In order to achieve the above object, according to the present invention, a case is arranged in a cavity formed inside, and the case is melted between the case and a mounting component arranged inside the case. An injection molding die for filling and integrally molding a resin, wherein a groove that opens to the cavity at a position covered by the case, a cooling medium supply port and a cooling medium discharge port that communicate with the groove. Have been proposed.

According to the injection molding die of the present invention, since the groove is opened in the cavity, by disposing the case in the cavity, the cooling medium is provided on the back side of the case by the wall of the case and the groove. A flow path is defined. The cooling medium supplied from the cooling medium supply port flows through the flow path and is discharged from the cooling medium outlet, so that the cooling medium flows while directly contacting the surface of the case, and the surface of the case is cooled. Is done. As a result, even if the temperature of the molten resin injected into the cavity is set relatively high, it is possible to prevent the case from being overheated and deformed by the heat.

Further, the present invention proposes an injection mold in which the groove is provided near a gate for injecting a molten resin into a cavity. According to the injection mold of the present invention, the molten resin in a high-temperature state is injected from the gate during the resin injection period. However, a groove is provided near the gate, and the opening of the groove is closed by the case. Thus, since the cooling medium flow path is formed, the portion of the wall surface of the case which is exposed to the high temperature state for the longest time can be cooled, and deformation can be effectively prevented.

Further, the present invention proposes the above-mentioned injection mold, which is made of an aluminum material or an aluminum alloy material. ADVANTAGE OF THE INVENTION According to the injection mold which concerns on this invention, the heat dissipation of the case heated by the molten resin of a high temperature state is promoted by being comprised by the aluminum material or aluminum alloy material with favorable thermal conductivity, and the deformation | transformation of the case Is more effectively prevented.

Further, the present invention proposes an injection mold having at least a surface in contact with a molten resin having irregularities formed by blasting or chemical treatment.
ADVANTAGE OF THE INVENTION According to the injection molding die which concerns on this invention, the mold release property of resin and a die is improved by the unevenness | corrugation provided in the surface which contacts a molten resin. That is, the surface of the injection mold that contacts the case is not bonded to the case because the case is not in a molten state, but the surface that directly contacts the molten resin is
It tends to be easily bonded to the molten resin.

In particular, when the injection mold is made of an aluminum material or the like, there is an inconvenience that, when mirror-finished by cutting, the adhesiveness to the resin is increased. Then, after the resin is cured, the resin and the mold are locally adhered to each other, and an excessive force may be applied to the molded product when the mold is opened. However, in the injection molding die according to the present invention, since the releasability between the resin and the die is improved by the fine irregularities provided on the surface of the die, it is possible to prevent the above-mentioned inconvenience.

Further, the present invention provides the above-mentioned injection mold,
A heating vessel that stores the molten resin while heating it to a certain temperature,
Pressurizing means for increasing the pressure inside the heating vessel to inject the molten resin into the injection mold from a nozzle provided in the heating vessel, and a cooling medium supply for supplying a cooling medium to the cooling medium supply port And an injection molding apparatus comprising:

According to the injection molding apparatus of the present invention,
The molten resin stored in the heating vessel while being heated to a certain temperature is injected from the nozzle into the injection mold by increasing the pressure inside the heating vessel. And
When the cooling medium is supplied to the cooling medium supply port by the operation of the cooling medium supply means, the cooling medium is caused to flow through the flow path defined between the groove communicating with the cooling medium supply port and the case. Is discharged from the cooling medium discharge port. As a result, the case is cooled, and overheating of the case by the molten resin is prevented.

H. The present invention also proposes an injection molding apparatus in which the nozzle is provided with a heater for heating the molten resin flowing in the nozzle in the above injection molding apparatus. ADVANTAGE OF THE INVENTION According to the injection molding apparatus which concerns on this invention, the fall of the temperature of the molten resin in the flow path from a heating container to an injection mold is prevented by operation of the heater provided in the nozzle, It will be supplied in the mold. As a result, a cooling medium flow path is provided in the mold,
Alternatively, even if the mold is made of an aluminum material or an aluminum alloy material and the cooling of the molten resin is promoted, the fluidity of the resin inside the mold is stably secured, and the occurrence of molding defects is reliably prevented. can do.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an injection mold and an injection molding apparatus according to the present invention will be described below with reference to the drawings. Injection mold 1 according to the present invention
Is a battery cover (case) as shown in FIG. 3, for example.
2 and the battery cells (mounted parts) placed inside
And a lower die 5 and an upper die 6, which are combined with each other, as shown in FIG. I have it. In FIG. 3, reference numeral 7 denotes a terminal for electrically connecting the battery 4 to a portable terminal body (not shown), and reference numeral 8 denotes an engagement means for fixing the battery 4 to the portable terminal body.

The lower die 5 includes a mounting recess 9 into which the battery cell 3 integrated with the battery lid 2 is inserted, a gate 10 for injecting molten resin, and a guide pin 11 for positioning with respect to the upper die 6. Is provided. Also provided in the center of the lower die 5 is a through hole 12 through which an ejector (not shown) for removing the battery 4 from the mounting recess 9 after the molding is completed.

A groove 13 is formed on a part of the bottom surface of the mounting recess 9 of the lower die 5 so as to open to the bottom surface of the mounting recess 9. The groove 13 is formed at a position covered by the back surface of the battery cover 2 when the battery cover 2 is inserted into the mounting recess 9. Thus, when the battery cover 2 is inserted into the mounting recess 9, a flow path 14 closed by the battery cover 2 and the groove 13 is formed on the back surface of the battery cover 2.

Further, as shown in FIG.
A cooling air supply port 15 and a cooling air discharge port 16 are formed in communication with each other at both ends thereof. Cooling air supply port 15
Is connected to a compressor via a pipe not shown,
Cooling air can be supplied into the groove 13. The groove 13 is preferably disposed at a position close to the gate 10.

The upper mold 6 is provided with the gate 10 of the lower mold 5.
And a guide hole 18 for fitting the guide pin 11, a battery cover 2 and a battery cell 3 inserted and disposed in the mounting recess 9 of the lower die 5.
And a resin-filled concave portion 20 defining a cavity 19 between them.

The lower mold 5 and the upper mold 6 are respectively
It is manufactured by cutting an aluminum material or an aluminum alloy material. Also, at least the upper mold 6
The inner surface of the resin-filled concave portion 19 has a depth of 10 μm by chemical treatment such as blasting or etching.
Fine irregularities of about 20 μm are formed. By forming such fine irregularities, the resin P that comes into contact with the surface of the mold cannot penetrate into the fine recess due to its surface tension. As a result, the surface of the mold 6 and the resin P
The contact area with the contact is reduced.

Next, the injection molding apparatus 21 for the battery 4 according to the present embodiment will be described. As shown in FIG. 4, the injection molding apparatus 21 of the present embodiment includes the above-described injection molding die 1, a heating container 22 for storing and heating the molten resin,
A nozzle 23 for supplying the resin P from the heating container 22 into the injection mold 1, a pressurizing means 24 for increasing the pressure in the heating container 22 to inject the molten resin P from the nozzle 23, and a cooling air supply port 15 (Cooling medium supply means) 37 connected to the compressor.

The heating vessel 22 is configured to store the molten resin P therein to keep it warm, and to heat the molten resin P to a constant temperature by a heater 25 provided inside. The nozzle 23 has a valve 2
The injection of the molten resin P from the heating container 22 can be turned on and off by opening and closing the valve 26. Further, a heater 27 is provided at the tip of the nozzle 23, and in the nozzle 23 from the heating container 22 to the inside of the injection mold 1, the nozzle 23 is provided in order to prevent the molten resin P from cooling down and reducing the fluidity. The molten resin P inside 23 can be heated and supplied to the injection mold 1 at a constant temperature.

The pressurizing means 24 comprises, for example, an air pressure supply source connected to a space above the liquid surface of the molten resin P stored in the heating vessel 22 to apply air pressure to the liquid surface. Thereby, the molten resin P can be injected from the nozzle 23 at a predetermined pressure. In the figure, reference numeral 28 denotes a handle for sealing the lid 29 of the heating container 22, reference numeral 30 denotes an elevating cylinder which raises and lowers the upper die 6 and clamps the die with a predetermined pressure, and reference numeral 31 denotes a metal cylinder. A positioning cylinder for positioning the battery lid 2 inserted and arranged in the mold 1 in the mounting recess 9;
Reference numeral 32 denotes a linear motion mechanism for connecting and disconnecting the nozzle 23 to and from the gate 10. The linear motion mechanism 32 includes a linear motion cylinder 33, a linear guide 34, and a slider 35 on which the heating container 22 is mounted. Reference numeral 36 denotes a heater temperature control device.

The operation of the injection molding die 1 and the injection molding apparatus 21 according to the present embodiment having the above-described configuration will be described.
This will be described below. In order to manufacture the battery 4 in which the battery lid 2 and the battery cell 3 are integrated using the injection molding die 1 and the injection molding device 21 according to the present embodiment, first, a resin is put into the heating container 22. By operating the heater 25, for example, the molten resin P heated to a temperature of 220 ° C. is stored. Then, the pressure inside the heating container 22 is increased by, for example, 0.4MP
Set to a.

Further, the linear motion cylinder 33 of the linear motion mechanism 32 is operated, and the slider 35 is retracted in a direction in which the nozzle 23 of the heating container 22 is separated from the gate 10. Further, by operating the elevating cylinder 30, the lower mold 5
The upper die 6 is raised.

Next, after the battery lid 2 and the battery cell 3 are arranged in the mounting recess 9 formed in the lower die 5, the positioning cylinder 31 is operated to put the battery lid 2 into the mounting recess 9.
Position within. Thereby, the cooling air flow path 14 is formed by the groove 13 formed in the lower die 5 and the back surface of the battery lid 2.
Is defined.

Thereafter, the lifting cylinder 30 is operated to
The upper mold 6 is lowered from above the lower mold 5, and the guide pins 11 of the lower mold 5 are fitted into the guide holes 18 of the upper mold 6, thereby clamping the two dies 5, 6 in a positioning state. For example, the mold clamping pressure is 0.6 MPa. Thereby, in the cavity 19 defined between the lower mold 5 and the upper mold 6, the resin P is filled between the battery lid 2 and the battery cell 3 and the resin filling recess 20 of the upper mold 6. The space will be defined.

Next, the linear motion mechanism 32 is operated to move the slider 35 forward, and the nozzle 23 of the heating vessel 22 is moved to the gate 1.
0, and supplies the cooling air supplied from the compressor 37 to the cooling air supply port 15. The cooling air supplied to the cooling air supply port 15 flows through the cooling air flow path 14 defined by the back surface of the battery lid 2 and the groove 13 formed in the lower mold 5, so that the cooling air flows from the battery lid 2. After the heat is removed, it is discharged through the cooling air discharge port 16.

In this state, inside the heating vessel 22,
The molten resin P, which is pressurized to a certain pressure by operating the pressurizing means 24, is supplied to the cavity 1 inside the mold 1 through the gate 10 by opening a valve 26 provided in the nozzle 23.
Inject into 9. The molten resin P is, for example, a polyamide resin, and is supplied into the injection molding die 1 while being heated to 200 ° C. by setting the temperature of the heater 27 of the nozzle 23 to 200 ° C.

The molten resin P injected into the cavity 19 through the gate 10 flows through the surface of the battery lid 2 disposed inside the cavity 19, and flows therethrough.
Gradually fill the space defined inside. The molten resin P is gradually cooled as it progresses in the space, and starts curing in a state where the space is completely filled. In this case, the battery cover 2 is
Since the battery lid 2 is constantly exposed to the high-temperature molten resin P continuously injected from the gate 10, the battery lid 2 at that position is heated for a long time from the start of injection to the end of injection.

In the injection mold 1 according to the present embodiment, a groove 13 is formed at a position near the gate 10 on the back surface of the battery cover 2, and a cooling air flow path is formed between the groove 13 and the back surface of the battery cover 2. 14, the cooling air supply port 15
The cooling air A supplied from the cooling air flow through the cooling air flow path 14 cools the wall surface of the battery cover 2. Therefore, it is possible to prevent inconveniences such as the battery cover 2 being overheated and deformed.

Further, unlike the case where the molten resin P is injected into the cavity 19 in a state where the temperature of the molten resin P is lowered, the fluidity of the molten resin P in the cavity 19 is not impaired. Therefore, it is possible to prevent the occurrence of molding defects such that the resin P does not spread over the entire space in the cavity 19.

Further, the injection mold 1 according to the present embodiment.
Is made of an aluminum material or an aluminum alloy material, the heat conductivity is good, and the heat transmitted from the molten resin P to the battery lid 2 is transmitted through the lower mold 5 and directly from the molten resin P. Heat is radiated through the upper mold 6. This can also prevent the battery cover 2 and the battery cell 3 from overheating.

The injection mold 1 made of an aluminum material or an aluminum alloy material has an advantage that it can be easily machined because of its good machinability and can be manufactured at very low cost. However, when the aluminum mold 1 is manufactured only by cutting, there is a disadvantage that the adhesiveness to the resin is increased and the mold release becomes difficult. Therefore, in the injection molding die 1 according to the present embodiment, since at least the surface in direct contact with the molten resin P is formed with extremely fine irregularities by blasting or chemical treatment, the resin and the surface of the die 1 can be formed. The contact area is reduced, and the releasability is not impaired.

As a result, since the resin and the mold 1 are locally adhered, it is possible to prevent an excessive force from being applied to the molded product at the time of release. In addition, the resin which has been in contact with the surface of the mold having the irregularities has an advantage that a grain-like pattern is formed on the surface and the texture of the resin can be improved.

Further, as described above, the molten resin P supplied to the injection molding die 1 in which the forced cooling by air and the heat radiation by the aluminum die 1 have been improved are applied to the gate of the injection molding die 1. Before being supplied to the nozzle 10, it is heated to a constant temperature by the heater 27 arranged near the injection port of the nozzle 23, so that it is always supplied into the injection mold 1 under the same thermal conditions. Therefore, even in the injection molding die 1, cooling can be performed with the same cooling pattern, and batteries 4 of the same quality can be continuously manufactured.

Thereafter, for example, after injecting the resin for a predetermined period of time, the valve 2
By closing the nozzle 6, the injection of the resin P is stopped, the linear motion mechanism 32 is operated, and the slider 35 is retracted, whereby the nozzle 23 is separated from the gate 10. At this time, the supply of the cooling air to the cooling air flow path 14 is continued without stopping. Then, after a predetermined time required for the resin P to cure, the supply of the cooling air is stopped,
The upper die 6 is raised by operating the elevating cylinder 30, and the battery 4 formed in the mounting recess 9 of the lower die 5 is taken out by an ejector (not shown).

The removed battery 4 contains the molten resin P
Is efficiently cooled during the injection of the molten resin P.
Is suppressed, and the battery lid 2 is manufactured without being deformed. In particular, no deformation is observed in the battery cover 2 near the gate 10 that is exposed to a high temperature for a long time.
Although the battery lid 2 is cooled efficiently, the cooling of the molten resin P is performed slowly through the battery lid 2, so that the molten resin P spreads to every corner of the space in the cavity 19,
A battery 4 without molding defects is manufactured. In addition, since the releasability of the resin from the mold 1 is improved by the fine irregularities on the mold surface, the external force applied to the battery 4 at the time of mold release is small, and a sound battery 4 is manufactured. .

In the above embodiment, a polyamide resin is used as the resin, but any other thermoplastic resin may be used instead. The shape and depth of the groove 13 through which the cooling air flows can be set as appropriate, and the position is not limited to the vicinity of the gate 10. In addition, as a method of forming fine irregularities on the surface of the mold 1, any method other than the blast treatment or the chemical treatment may be used. Further, in the above-described embodiment, the case where the case is a battery lid and the mounted component is a battery cell is described, but the present invention is not limited to this, and any other case and the mounted component are integrally formed. Can be applied in case.

[0040]

As is clear from the above description, the present invention has the following effects. According to the injection mold according to the present invention, the cooling medium supplied from the cooling medium supply port flows through the flow path defined by the case and the groove, and is discharged from the cooling medium discharge port. Can be cooled directly. Therefore, the case can be prevented from being deformed due to overheating, and the molten resin is not directly cooled. Therefore, the flowability of the molten resin is not reduced, and the occurrence of molding defects can be prevented. It works.

By arranging this groove near the gate, the case at a portion where heating is continued for a long time from the start of injection to the end of injection can be cooled, and deformation of the case can be effectively prevented. This has the effect. Further, by using an aluminum material or an aluminum alloy material, there is an effect that thermal conductivity is improved and heat transmitted from the molten resin to the case can be efficiently dissipated. In addition, when an injection molding die is manufactured from an aluminum material, there is an advantage that manufacturing is easy because machinability is good.

Further, according to the injection molding die of the present invention, by providing fine irregularities on the surface in contact with the molten resin, the adhesiveness between the resin and the die, which is increased by being made of an aluminum material, can be reduced. This has the effect of reducing the pressure and improving the releasability. In addition, there is an advantage that a grain pattern formed by fine irregularities can improve the texture of a molded product.

Further, according to the injection molding apparatus of the present invention, the temperature of the molten resin to be supplied to the injection molding die, which is improved in heat dissipation and cooling as described above and is actively cooled, is controlled. The cooling condition in the injection mold can be always kept constant because the heater provided in the nozzle can keep the temperature constant. As a result, there is an effect that the quality of the manufactured battery can be kept constant.

[Brief description of the drawings]

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

FIG. 2 is a longitudinal sectional view showing a cooling medium flow path of the injection mold of FIG.

FIG. 3 is a front view showing a battery manufactured by the injection mold of FIG. 1;

FIG. 4 is a front view showing an injection molding apparatus according to one embodiment of the present invention.

[Explanation of symbols]

 P molten resin 1 mold (injection molding mold) 2 battery lid (case) 3 battery cell (mounting part) 4 battery 10 gate 13 groove 15 cooling air supply port (cooling medium supply port) 16 cooling air discharge port (cooling medium) Discharge port) 19 Cavity 21 Injection molding device 22 Heating container 23 Nozzle 24 Pressurizing means 27 Heater 37 Compressor (Cooling medium supply means)

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4F202 AH42 AJ02 AJ12 AM32 CA11 CB01 CD23 CK06 CK11 CN05 CN12 CN22 4F206 AH42 AJ02 AJ12 AM32 JA07 JL02 JM05 JN21 JQ69 JQ81

Claims (6)

[Claims] 1. An injection molding die for disposing a case in a cavity formed inside and filling a molten resin between the case and a mounting component disposed inside the case to integrally mold the case. An injection mold comprising: a groove that opens to the cavity at a position covered by the case; and a cooling medium supply port and a cooling medium discharge port that communicate with the groove. 2. The injection mold according to claim 1, wherein the groove is provided near a gate for injecting the molten resin into the cavity. 3. The injection mold according to claim 1, wherein the mold is made of an aluminum material or an aluminum alloy material. 4. The injection mold according to claim 3, wherein at least a surface in contact with the molten resin has irregularities formed by blasting or chemical treatment. 5. An injection mold according to claim 1, a heating container for storing the molten resin while heating the resin to a constant temperature, and increasing a pressure inside the heating container. An injection molding apparatus comprising: a pressurizing unit that injects a molten resin into the injection mold from a nozzle provided in the heating container; and a cooling medium supply unit that supplies a cooling medium to the cooling medium supply port. 6. The injection molding apparatus according to claim 5, wherein the nozzle is provided with a heater for heating the molten resin flowing in the nozzle.