JP2004268072A - Releasing agent applying device and releasing agent applying method for molding die - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a releasing agent applying device and a releasing agent applying method for a molding die, wherein the joining state of a molding die is excellently maintained and the molding agent is not used wastefully. <P>SOLUTION: An injection molding apparatus 10 is provided with a molding die that has a recessed part for molding, which consists of a recess 13b and a protrusion 14b, on joining-surfaces 13a, 14a of a fixed die 13 and a movable die 14, which are openable and closable, and that forms a molding of a prescribed shape by filling the recessed part for molding with a molten material. A releasing agent applying device 20 is provided in the injection molding apparatus 10, The releasing agent applying device 20 is composed of: an electric charge source 25 positively electrifying the fixed die 13 and the movable die 14 and negatively electrifying a releasing agent 23; insulation film parts 15a, 15b arranged on the areas of the fixed die 13 and the movable die 14, which exclude the recessed part for molding; and the like. Further, the releasing agent applying device 20 is provided with a spray head 24 removing the positive electrification of the insulation film parts 15a, 15b by jetting anions to the fixed die 13 and the movable die 14 that are positively electrified by a charging source 25. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a mold release agent application device and a mold release agent application method for applying a release agent to a molding recess of a molding die.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, for example, in casting using a molding die such as die casting, a release agent has been used in order to facilitate removal of a molded product from the molding die. The release agent is applied to the molding recess formed on the joint surface between the fixed mold and the movable mold that constitute the molding die each time each molded product formed by casting is removed from the molding die. When applying the release agent, the release agent is applied to portions of the molding die that do not need to be applied, or the release agent does not reach the portions that need to be applied hidden behind the protrusions and is not applied. There is. For this reason, in order to prevent such a situation, the mold is positively charged, and the mold release agent is applied to the mold by charging the mold release agent negatively and attracting each other. (For example, see Patent Document 1).
[0003]
[Patent Document 1]
JP-A-6-182519
[Problems to be solved by the invention]
However, in the conventional release agent application method, it is difficult to apply the release agent only to the concave forming surface of the molding concave portion on the joining surface of the molding die, and it is difficult to apply the releasing agent to other portions of the joining surface and portions other than the joining surface. Also, a release agent may be applied. For this reason, there has been a problem that the release agent is deposited on the joining surface of the molding die to deteriorate the bondability between the fixed die and the movable die, and that the release agent is wasted.
[0005]
Summary of the Invention
The present invention has been made in order to address the above-described problem, and an object thereof is to maintain a good joining state of a molding die by allowing a release agent to be applied only to a concave portion for molding that requires application. It is an object of the present invention to provide a mold releasing agent applying apparatus and a method of applying a releasing agent to a molding die, which is possible and eliminates waste of the releasing agent.
[0006]
In order to achieve the above-mentioned object, a configurational feature of the mold releasing agent application device for a molding die according to the present invention is that a molding concave portion is formed on a joint surface between a fixed die and a movable die that constitute a mold that can be opened and closed. A mold release agent coating device for applying a mold release agent to a concave portion forming surface of the molding concave portion and filling the molding concave portion with a molten material to form a molded product having a predetermined shape. A charging device for charging the fixed mold and the movable mold to one polarity and charging the release agent to the other polarity, and an insulating device provided at a predetermined portion of the fixed mold and the movable mold except for a molding recess. A film portion, an ion supply device for supplying ions of the other polarity to the fixed type and the movable type charged to one polarity by the charging device to set the insulating film portion to a non-charged state or a charged state of another polarity; and That you have.
[0007]
In the mold release agent coating device of the present invention having the above-described configuration, an insulating film portion is provided in a predetermined portion of the fixed die and the movable die except for the concave portion for molding, and the inside of each of the molds is provided. It is electrically insulated from the outside. Therefore, when the fixed device and the movable mold are charged to one polarity by the charging device, the concave portion forming surface of the molding concave portion is charged to that polarity, and the other portions provided with the insulating coating portion are provided. Becomes electrically insulated.
[0008]
Then, the insulating coating portion is uncharged or charged to another polarity by the ions of the other polarity supplied by the ion supply device, and the release agent is more reliably applied in a uniform state only to the concave portion forming surface of the molding concave portion. You. For this reason, when the release agent charged to the other polarity by the charging device is sprayed toward the concave portion for molding, the release agent is attracted only to the concave portion forming surface of the concave portion for molding and is applied in a uniform state. As a result, a good release agent layer without waste is formed only in the molding concave portions.
[0009]
Further, another structural feature of the mold releasing agent coating device of the molding die according to the present invention is that a predetermined portion provided with an insulating film portion is formed by removing a molding concave portion at a joint surface between a fixed die and a movable die. Is to be part. According to this, in the portion other than the molding concave portion of the molding die, the release coating agent is easily applied, and since the insulation coating portion is provided only on the joint surface where problems are likely to occur when applied, the insulating coating portion is provided. Can be provided minimally and effectively.
[0010]
The constitutional features of the method for applying a release agent of a molding die according to the present invention include a fixed mold and a movable mold in which a molding concave portion is provided on a joining surface and an insulating film portion is provided in a predetermined portion excluding the molding concave portion. And a fixed type and a movable type charged to one polarity by the charging process, and the other polarity ions are ejected to the insulating film portion in the non-charged state or the other polarity. In other words, the method includes an ion spraying step of making the charged state, and a release agent applying step of applying a release agent charged to the other polarity to the molding concave portion on the joint surface between the fixed mold and the movable mold.
[0011]
In the mold release agent applying method of the molding die according to the present invention, in the charging step, the fixed mold and the movable mold are charged to one polarity, and the fixed mold and the movable mold have the other polarity in the ion injection step. By injecting ions, the insulating film portion is set to a non-charged state or a charged state of the other polarity. In this case, even if ions of the other polarity are jetted to the concave forming surface of the molding concave, the concave forming surface is immediately charged to one polarity. Therefore, when a mold release agent charged to the other polarity is sprayed on the molding concave portion on the joint surface between the fixed mold and the movable mold, the mold releasing agent is applied only to the concave portion forming surface of the molding concave portion avoiding the insulating coating portion. You. As a result, a good release agent layer without waste is formed only in the molding concave portions.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic configuration diagram of a main part of an injection molding apparatus 10 including a mold release agent applying apparatus 20 for a molding die according to the present invention. The injection molding apparatus 10 includes a fixed plate 11 and a movable plate 12 that is provided so as to be capable of moving forward and backward facing the fixed plate 11. A fixed mold 13 is attached to the fixed plate 11, and a movable mold 14 is attached to the movable plate 12. A concave portion 13b and a protrusion 14b which are assembled to form the concave portion for molding of the present invention are formed at the center of the joint surfaces 13a, 14a of the fixed die 13 and the movable die 14, respectively. The fixed die 13 and the movable die 14 constitute a molding die of the present invention.
[0013]
Antistatic insulating coating portions 15a and 15b made of alumina or the like are formed on portions of the surface of the fixed die 13 other than the concave portions 13b and portions of the surface of the movable die 14 except for the protrusions 14b, respectively. A runner 13c is formed at the center of the fixed mold 13 so as to penetrate left and right as shown in the figure. The runner 13c communicates with a casting port 11a provided at the center of the fixed plate 11. Therefore, the molten material is supplied to the casting port 11a side with the fixed mold 13 and the movable mold 14 closed, and the molten material is cast to the runner 13c side by a plunger (not shown). It is press-fitted into the molding recess and molded into a predetermined shape.
[0014]
Further, a spray head for spraying the release agent 23 supplied from the release agent tank 21 by driving the pump 22 onto the molding recess is provided above the joining surfaces 13a and 14a between the fixed die 13 and the movable die 14. 24 are provided. The spray head 24 can be moved up and down by driving a lifting device (not shown). When the fixed mold 13 and the movable mold 14 are closed, the spray head 24 is retracted upward, and the When the movable mold 14 is opened, the movable mold 14 is lowered and the release agent 23 is applied to the surfaces of the concave portion 13b and the protrusion 14b.
[0015]
A positive terminal 25a of a charging power supply 25 constituting the charging device of the present invention is connected to the interior of the fixed mold 13 and the movable mold 14 via wirings 26a and 26b, respectively. The 25 negative terminals 25 b are connected via the wiring 27. The negative terminal 25b of the charging power supply 25 and the spray head 24 also have a function as the ion supply device of the present invention.
[0016]
The release agent applying device 20 is constituted by the release agent tank 21, the spray head 24, the charging power supply 25, the wirings 26a, 26b, 27, and the insulating coating portions 15a, 15b provided on the fixed mold 13 and the movable mold 14, respectively. Be composed. Further, the injection molding apparatus 10 includes a control device (not shown) including a CPU, a ROM, a RAM, and various circuits, and each device constituting the injection molding device 10 is controlled by the control device. Its operation is controlled.
[0017]
When an injection-molded product is injection-molded using the injection molding device 10 including the release agent coating device 20 configured as described above, first, the fixed die 13 and the movable die 14 are charged by the charging power supply 25. As shown in FIG. 2 (only the movable mold 14 is shown in FIG. 2. In the drawings attached for the following description, only the movable mold 14 side portion is shown). Is done. In this case, the insulating coating portions 15a and 15b are not charged or, as shown in FIG. 3A, the portion in contact with the fixed mold 13 or the movable mold 14 is negatively charged, and faces toward the space. The opened portion becomes a positively charged state.
[0018]
Then, the spray head 24 descends between the fixed mold 13 and the movable mold 14 in the opened state, and injects negative ions into the recess 13b and the protrusion 14b as shown in FIG. 3B. . As a result, the positive charge of the insulating coating portions 15a and 15b is cancelled, and becomes a non-charged state as shown in FIG. 3 (c) or a negative charge state as shown in FIG. 3 (d). Become. The surfaces of the recess 13b and the protrusion 14b are maintained in a positively charged state by the charging power supply 25.
[0019]
When this state is reached, the pump 22 operates to supply the release agent 23 in the release agent tank 21 to the spray head 24, and the spray head 24 makes the release agent 23 into a mist and forms the recess 13b. It is sprayed on the surface of the projection 14b. At this time, the release agent 23 is negatively charged in the spray head 24 and is ejected from the spray head 24. As a result, the negatively charged release agent 23 is applied in a uniform state so as to be sucked into the positively charged concave portions 13b and the protruding portions 14b.
[0020]
Further, since the insulating coating portions 15a and 15b formed around the concave portion 13b and the protruding portion 14b have only non-charged or negatively charged portions, the release agent 23 is not sucked or repelled. It is not applied to this part. Therefore, a layer of the release agent 23 is formed only in the concave portion for molding. The layer of the release agent 23 is formed to have a uniform and uniform thickness.
[0021]
Next, the spray head 24 moves up and retreats from between the fixed mold 13 and the movable mold 14, and the movable mold 14 moves to the fixed mold 13 side to close the mold. Then, the molten material is cast into the molding recess and solidified in the molding recess. This solidification is performed when the mold temperature of the fixed mold 13 and the movable mold 14 is lower than the solidification temperature of the molten material, thereby removing heat from the molten material.
[0022]
When the solidification of the material is completed, the movable mold 14 moves in a direction away from the fixed mold 13 to open the mold, and the molded product is taken out. This removal is performed by a removal device (not shown). At this time, the molded product is smoothly separated from the fixed mold 13 and the movable mold 14 by the action of the mold release agent 23, so that the molded article is not chipped or broken. When the removal of the molded product is completed, the spray head 24 is lowered again, and the above-described operation is repeated. By repeating this operation, molding of a large number of molded articles is performed.
[0023]
As described above, in the present embodiment, the insulating coating portions 15a and 15b are provided in portions of the fixed die 13 and the movable die 14 except for the concave portion 13b and the protrusion 14b. The fixed mold 13 and the movable mold 14 are positively charged, and negative ions are jetted to the insulating film portions 15a and 15b on the joint surfaces 13a and 14a. In this state, the negatively charged release agent 23 is applied to the recess 13b and the protrusion 14b.
[0024]
Therefore, even if the insulating coating portions 15a and 15b are positively charged by the charging power supply 25, the positive charge of the portions of the insulating coating portions 15a and 15b on the joining surfaces 13a and 14a is removed by the negative ions ejected from the spray head 24, The release agent 23 is applied in a uniform state only to the surface of the recess 13b and the protrusion 14b. Therefore, the releasability of the molded article from the fixed mold 13 and the movable mold 14 is improved, and a good molded article can be obtained.
[0025]
In the above-described embodiment, the negative ions are jetted to the insulating coating portions 15a and 15b before the release agent 23 is applied. However, the insulating coating portions 15a and 15b may have a large antistatic effect. For example, the release agent 23 can be applied as it is without performing the injection of the negative ions. In this case, between the inside and the outside of each of the fixed mold 13 and the movable mold 14 except for the concave portion 13b and the protrusion 14b are electrically insulated by the insulating coating portions 15a and 15b. I have.
[0026]
Therefore, when the fixed mold 13 and the movable mold 14 are positively charged, the surface portions of the concave portion 13b and the protrusion 14b are positively charged, and the portions provided with the insulating coating portions 15a and 15b are electrically charged. Insulated state is obtained. Therefore, when the negatively charged release agent 23 is sprayed toward the concave portion 13b and the protrusion 14b, the release agent 23 is uniformly applied to only the surface of the concave portion 13b and the protrusion 14b. As a result, a good layer of the release agent 23 without waste is formed only in the concave portions 13b and the protrusions 14b constituting the concave portions for molding.
[0027]
Further, in the present embodiment, the insulating coating portions 15a and 15b are formed in all portions of the fixed die 13 and the movable die 14 except for the concave portion 13b and the protruding portion 14b, but the insulating coating portions 15a and 15b are formed. May be provided only in portions other than the concave portion 13b and the protruding portion 14b in the joint surfaces 13a and 14a. The joining surfaces 13a and 14a are surfaces at positions where the mold release agent 23 is easily applied, and when the mold release agent 23 is deposited on this surface, the jointability between the fixed mold 13 and the movable mold 14 at the time of mold clamping is improved. The problem of getting worse occurs.
[0028]
For this reason, even if the insulating coating portions 15a and 15b are formed only on the joining surfaces 13a and 14a other than the recessed portions 13b and the protruding portions 14b, it is possible to prevent the problem of the deterioration of the joining property and to form a good release agent layer. become. In addition, this allows the insulating coating portions 15a and 15b to have a minimum amount, so that cost can be reduced and manufacturing effort can be reduced.
[0029]
Further, in the present embodiment, the fixed mold 13 and the movable mold 14 are positively charged, negative ions are ejected to the fixed mold 13 and the movable mold 14, and the release agent 23 is negatively charged. May be used. Further, the negative ions are not limited to being sprayed, but may be applied or supplied in another form. The method for charging the molds 13 and 14 and the release agent 23 is not limited to the method of the embodiment, and the molds 13 and 14 and the release agent 23 may be charged to different polarities. Anything that can be done is acceptable.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram illustrating an injection molding apparatus including a release agent applying apparatus according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view illustrating a movable charging state.
FIGS. 3A and 3B are cross-sectional views showing a movable charging state, in which FIG. 3A is a state in which a bonding surface and a surface of an insulating film portion are positively charged, and FIG. 3B is a bonding surface and an insulating film shown in FIG. (C) shows the state where the positive charge on the surface of the insulating film is removed and becomes uncharged, and (d) shows the state where the surface of the insulating film is negatively charged. Is shown.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Injection molding apparatus, 13 ... Fixed type, 13a, 14a ... Joining surface, 13b ... Concave part, 14 ... Moving type, 14b ... Protrusion, 15a, 15b ... Insulating film part, 20 ... Release agent coating device, 24 ... Spray head, 25: charging power supply, 25a: plus terminal, 25b: minus terminal.

Claims (3)

A molding recess is provided on a joint surface between a fixed mold and a movable mold that constitute a mold that can be opened and closed, and a mold release agent is applied to a recess forming surface of the molding recess to apply a molten material in the molding recess. A mold release agent coating device for a molding die for molding into a molded product of a predetermined shape by filling,
A charging device that charges the fixed type and the movable type to one polarity, and charges the release agent to the other polarity,
An insulating film portion provided at a predetermined portion of the fixed die and the movable die except for the molding concave portion,
An ion supply device that supplies ions of the other polarity to the fixed type and the movable type charged to one polarity by the charging device to put the insulating coating portion in an uncharged state or a charged state of another polarity. A mold release agent coating device for a molding die. 2. The mold release agent coating device according to claim 1, wherein the predetermined portion provided with the insulating coating portion is a portion excluding the molding concave portion on a joining surface between the fixed die and the movable die. 3. A charging step of charging the fixed mold and the movable mold, each having a molding concave portion provided on the joining surface, and a fixed mold provided with an insulating film portion at a predetermined portion excluding the molding concave portion, to one polarity,
An ion injection step of injecting ions of the other polarity to the fixed type and the movable type charged to one polarity by the charging step to set the insulating film portion to a non-charged state or a charged state of the other polarity,
A mold release agent applying step of applying a mold release agent charged to the other polarity to the molding concave portion on the joint surface between the fixed mold and the movable mold. Coating method.

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