JP2000246744A - Molding machine and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To upgrade releasability of a resin product and connectibility of a mold release material to a mold, to deal with the product of a complicated shape and to reduce a mass production cost by engaging a resin of the product formed in a cavity of the mold and an engaging part of a back surface side of a releasable resin film having a non-connectible resin with the mold. SOLUTION: A vacuum casting mold 1 before updating is previously mounted at an in-mold mold, and a releasable resin film 2 is removed by an injecting pin. Then, a tip end position of the pin is positioned on a back surface of an engaging part 21 of an injecting hole 3, an injection mold is mounted at the in-mold mold, and a mold constitution in an injection molding machine is completed. A polypropylene resin is injected in the machine to form the film 2 and the part 21. Then, the constitution is disassembled, the mold 1 is removed, thereby obtaining an updating mold 10 for forming the film 2 engaged with the cavity of the mold 1 by the part 21. Thus, the mold releasability and the connectivity of the film to the mold are upgraded, a mold releasing material coating work is omitted, thereby reducing a mass production cost.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molding apparatus in a resin molding method using vacuum casting, and a manufacturing apparatus for maintaining or forming the molding apparatus.

[0002]

2. Description of the Related Art A resin molding method by vacuum casting is one of the methods of molding a thermosetting resin. A resin in a liquid state is defoamed in a vacuum atmosphere, and a curing agent is added thereto. , The resin product is injected into a molding device, and then
This is a method in which the injected resin is solidified by holding it for several tens minutes in a high temperature atmosphere of about 00 ° C. In recent years, this vacuum casting,
It is also used for a method of integrating a plurality of electronic components into an integrated functional component. For example, it is widely applied to, for example, completely sealing an electronic control device such as a microcomputer with a resin to form an integrated component.

In the resin molding method by vacuum casting, a liquid resin is poured into a molding device, and after the liquid resin is thermally cured, the formed resin is taken out from the molding device to form a product. When taking out by molding, there is a case where a problem occurs that the product surface comes into close contact with the molding device and peels off. Therefore, a preventive measure is required. Conventionally, as a preventive measure, a mold release agent having an adhesion preventing action is applied to the inner surface of a mold as a molding device, or a resin film having a good mold release property is mounted in place of the mold release agent. Have been done. When applying a mold release agent, it is necessary to apply a mold release agent having a thickness of several μm to the inner surface of the mold which becomes a cavity of the mold device each time the mold device is used. Further, it is necessary to wash and remove the release agent before reuse of the molding apparatus. However, the work of uniformly applying the release agent and washing and removing the release agent attached to the mold is a burden on the production line, and improvement of the operation has been demanded. Heretofore, as a method of simplifying and solving the trouble of applying and releasing the release agent, a method of attaching a resin film having a good release property to the inner surface of the molding apparatus has been devised.

[0004]

However, when electronic parts and wiring boards are resin-sealed using a vacuum casting method to form a block-shaped resin product, the degree of unevenness in the external shape of the resin product is high. Therefore, if a method using a resin film is used to cope with the problem, there is a limit in the conformability and adhesion of the resin film to a mold, and there is a problem that a required external shape cannot be realized. Therefore, the development of a mass-production means having good releasability and at the same time capable of responding to a resin product having a complicated shape has become an issue. Also, since one set of molding equipment has only about two processing capacity per hour, when mass-producing tens or hundreds of moldings per hour, a large number of molding apparatuses according to the production amount are required. It is necessary to prepare at a polished finish level with a concave cavity that reflects the external shape of the resin product, which imposes a large burden on production preparation costs, and there has been a demand for cost reduction. That is, from the viewpoint of cost reduction, the use of a transfer mold for preparing a reference model (convex shape) as a master of a molding apparatus and transferring the same has been studied. (In this case, it is sufficient to use a convex polishing finish that reflects the external shape, the polishing cost is lower than that of the concave finishing, and the number of polishing finishes is greatly reduced.) An object of the present invention is to provide a resin product. Molding equipment that has good mold release properties and good moldability of mold release agent, and can respond to resin products with complicated shapes, while at the same time reducing mass production costs.
And a manufacturing apparatus for a molding apparatus.

[0005]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems. In a molding apparatus for molding a resin product, a mold having a cavity and a resin product formed on a cavity surface of the mold are provided. Wherein the resin is a release resin film having a non-bonding resin, and an engaging portion provided on the back side of the release resin film is engaged with the mold. And

[0006] Further, the mold is provided with an eject hole formed from the back surface to the cavity, and the engaging portion is engaged with the eject hole.

A mold having a cavity, a mold release resin film formed on the cavity surface of the mold and having a resin which is not bonded to the resin in the resin product, and a back surface of the mold. An ejecting hole formed over the cavity, and a manufacturing apparatus of a molding apparatus in which an engaging portion provided on the back side of the release resin film is engaged with the ejecting hole. It has an eject pin protruding from the back surface of the mold toward the cavity, the engaging portion is protruded by the eject pin, and the release resin film is removed from the cavity surface of the mold. Features.

A mold having a cavity, a mold release resin film formed on the cavity surface of the mold and having a resin which is not bonded to the resin in the resin product, and a back surface of the mold. An ejecting hole formed over a cavity, and a manufacturing apparatus of a molding device in which an engaging portion provided on the back side of the release resin film is engaged with the ejecting hole, and is provided on a resin injection side. An injection-molded core mold having a core surface corresponding to the shape of the release resin film, an eject pin protruding from a back surface of the mold toward a cavity through the eject hole, and A holding mold provided on a side facing the molding core mold and holding the back side of the mold in-mold, and a tip of the eject pin is located at a position corresponding to a back side of the engaging portion. Status A resin is injected from the injection-molded core mold to the core surface, the cavity surface of the mold held in-mold by the holding mold, the core surface of the injection-molded core mold, and the eject pin. Wherein the releasable resin film and the engaging portion are formed in a space surrounded by the tip of the resin.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, a molding apparatus used for vacuum casting according to an embodiment of the present invention will be described. FIG.
FIG. 1 is a configuration diagram (cross-sectional view) illustrating a configuration of a molding apparatus according to an embodiment of the present invention. In this drawing, only one of the plurality of molding apparatuses constituting the molding apparatus will be described.

Reference numeral 1 denotes a vacuum casting mold having a cavity corresponding to the shape of a resin product, which is formed of a steel block for a mold,
A cavity surface corresponding to the shape of the resin product is formed by mechanical cutting or the like. Reference numeral 2 denotes a mold releasing resin film which forms a cavity surface that comes into contact with the cast resin, is made of polypropylene resin or the like, and is a vacuum casting mold 1 using an injection molding method.
Is formed as a film (about 1 to 2 mm thick) in close contact with the cavity surface. The releasable resin film 2 comprises a vacuum casting mold 1.
And a plurality of engaging portions 21 that engage with the space portion 11 (hole diameter 5 mm, depth 5 mm, deepest hole diameter 8 mm on the cavity side surface of the mold) having a spread to the rear side provided in The adhesion of the vacuum casting mold 1 to the cavity side surface is maintained through the portion 21. This engaging portion 21
Has a tapered shape that extends to the rear side of the vacuum casting mold 1 so as to be able to engage with the space 11 described above. Further, the release resin film 2 made of a polypropylene resin or the like is fused with a thermosetting resin such as a urethane resin to be vacuum cast, for example.
Alternatively, since the thermosetting resin does not have a property of being bonded by adhesion or the like, the thermosetting resin cast in vacuum can be easily separated from the molding device 10 after being cured.

Reference numeral 3 denotes an ejection hole provided in the vacuum casting mold 1 used for removing the release resin film 2. The ejection hole 3 has a space 11 on the cavity surface side. It is formed as an opening (5 mm in diameter) on the back surface. When the release resin film 2 is removed after the release resin film 2 is repeatedly used in a vacuum casting process and the use limit is reached due to abrasion or the like, as shown in FIG.
1 is guided by the eject hole 3 and inserted from the back of the vacuum casting mold 1, extrudes the mold release resin film 2 together with the engaging portion 21, and separates and removes the resin film 2 from the vacuum casting mold 1.

Reference numeral 4 denotes an injection runner section as a path for injecting a liquid thermosetting resin during vacuum casting. The injection runner section is formed at a position shown by a dotted line as a half-tubular path on the cavity surface side. . The injection runner section 4 forms a tubular path for injecting a thermosetting resin together with the injection runner section 4a of the opposing molding apparatus 10a facing the molding apparatus 10, as shown in FIG. Reference numeral 10 denotes a half mold device having a cavity surface used for vacuum casting, which comprises a vacuum casting mold 1 and a release resin film 2 (including an engaging portion 21). Since the molding device 10 having the half cavity surface is fastened to the opposing molding device 10a (shown in FIG. 2) having the half cavity surface on the other side, a fastening structure (not shown) for fastening is used. (For example, a bolted structure).

Next, a description will be given of a configuration of a molding apparatus at the time of vacuum casting according to an embodiment of the present invention. FIG. 2 is an explanatory view (cross-sectional view) illustrating the configuration of the molding apparatus during vacuum casting according to the embodiment of the present invention. Note that the same parts as those described in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted.
Further, each part having the same content as that of the other half-split opposing molding apparatus 10a facing the half-split molding apparatus 10 used for vacuum casting is denoted by the letter a at the end of the same number, and the description is omitted.

Reference numeral 10a denotes a half-way facing molding apparatus having a cavity surface (facing the cavity surface of the molding device 10) used for vacuum casting. Opposing molding device 10
a is composed of a vacuum casting mold 1a and a releasable resin film 2a (including an engaging portion 21a), a space portion for engaging (an engaging portion 21a), an eject hole 3a, an injection runner portion 4a.
And so on. In addition, the opposed mold device 10a having a half cavity surface is fastened to the opposite mold device 10a (shown in FIG. 2) having a half cavity surface on the other side, and therefore, a fastening structure (not shown) for fastening is used. For example, the molding apparatus 10 and the opposing molding apparatus 10a are fastened to form the molding apparatus configuration during vacuum casting shown in FIG.
When the releasable resin film 2a of the opposing molding device 10a is also removed for replacement, it is separated and removed from the vacuum casting mold 1a by the eject pin 31 as in the description of the molding device 10.

Reference numeral 5 denotes a resin product, which is a thermosetting resin cast in a vacuum, and fills a cavity (a shape opposed to the resin product 5) formed by the release resin film 2 and the release resin film 2a. For example, it is formed of a thermosetting resin such as a urethane resin. The outline of the vacuum casting of the thermosetting resin forming the resin product 5 will be described below. First, a liquid thermosetting resin (for example, in the case of a urethane resin, a hardener isocyanate is added to a liquid main material polyol and a high temperature (for example, 80
(° C) to form a liquid thermosetting resin), which is produced as a liquid resin material before being reacted and polymerized and cured. Next, this liquid resin material passes through a tubular path formed by the injection runner section 4 and the injection runner section 4a under a vacuum atmosphere (for example, 10 Torr) for removing bubble defects in the resin. The resin is injected into a cavity (a shape corresponding to the resin product 5) formed by the mold release resin film 2 and the mold release resin film 2a of the molding apparatus 10 and the opposing molding apparatus 10a. In the cavity, an article to be sealed, such as an electronic component receiving a resin seal or an electronic control component, is positioned and held. Further, the molding device 10 and the counter molding device 10a are maintained at a high temperature (for example, 80 ° C.) by heating and heat retaining means, and after the injection, the polymerization reaction of the thermosetting resin proceeds, and the thermosetting resin takes time. At the same time, it transforms from liquid to solid. After a predetermined time (for example, 20 minutes), the thermosetting resin is transformed and solidified, and is taken out of the vacuum atmosphere to the atmospheric pressure atmosphere. The pair of molding apparatuses shown in FIG. 10, and opposing molding apparatus 10a
And the resin product 5 is taken out. The pair of disassembled mold devices 10 and 10a are fastened again and provided for the next vacuum injection process.

As described above, since the vacuum injection process is performed, the pair of mold devices 10 and 50 are divided into half.
At the time when the resin product 5 is decomposed into 10a, the resin product 5 can be easily peeled off from the release resin films 2 and 2a and taken out. There is no problem such as loss of

Since the mold release resin films 2 and 2a are hardly damaged by abrasion or the like, the molding device 10
10a can be used several tens of times continuously. In addition,
In the vacuum casting process, the curing time of the resin is required, so that there is a restriction that the use of a pair of molding devices (the molding devices 10 and 10a) is limited to about two to three times per hour, and production is performed in a mass production process. It is necessary to prepare a number of molding apparatuses 10, 10a corresponding to the quantity.

Next, a method of removing the releasable resin films 2, 2a from the molding devices 10, 10a according to the embodiment of the present invention will be described. FIG. 3 is an explanatory view (cross-sectional view) illustrating removal of the release resin films 2 and 2a according to the embodiment of the present invention. As described above, the process of removing the release resin films 2 and 2a from the molding devices 10 and 10a is performed when the release resin films 2 and 2a are damaged by abrasion or the like. , 2a before updating and forming. The same parts as those described in FIGS. 1 and 2 are denoted by the same reference numerals, and description thereof will be omitted. In this figure, only one vacuum casting mold 1 will be described.

Reference numeral 51 denotes an in-mold mold for an injection molding machine for in-molding the mold-releasing resin film 2 into the vacuum casting mold 1, which comprises a mold steel block. Is formed in an injection molding machine so as to be opposed to an injection-side mold 52 on the resin injection side shown in FIG. 4 described later.
31 is a through-hole 51 provided in the in-mold mold 51.
1 and an ejection hole 3 provided in the vacuum casting mold 1
This is an eject pin which is made of a hard steel material such as tool steel and is configured to be movable in the direction of the arrow in the figure. The eject pin 31 is inserted from the back of the vacuum casting mold 1 through the through hole 511 and the eject hole 3, and is vacuum-injected by a press mechanism (not shown) using the press pressure of the mold setting of the injection molding machine. A pressure input is given to the mold 1 and the releasable resin film 2 and its engaging portion 21 are pushed out from the back side by the eject pin 31. That is, by this press input, the engaging portion 21 engaged with the space portion 11 is separated from the space portion 11 and the releasable resin film 2 is separated from the vacuum casting mold 1.

Next, a method for forming a release resin on the surface of a molding apparatus according to the embodiment of the present invention will be described. FIG.
FIG. 1 is an explanatory view (cross-sectional view) illustrating a forming apparatus of a molding apparatus according to an embodiment of the present invention, and shows a configuration of a mold part for injection-molding a resin of an injection molding machine. The mold release resin 2 is formed on the molding apparatus 10 when the mold release resin film 2 is renewed (or newly formed) in the vacuum casting mold 1. Parts similar to those described with reference to FIGS. 1, 2 and 3 are denoted by the same reference numerals, and description thereof is omitted. In this figure, only one vacuum casting mold 1 will be described.

Reference numeral 51 denotes an in-mold mold for an injection molding machine for in-molding the mold release resin film 2 into the vacuum casting mold 1, which comprises a mold steel block, and is provided on a fixed side in the injection molding machine. And the vacuum casting mold 1 is connected to the injection mold 52 on the resin injection side.
Is provided so as to face and be held. Reference numeral 12 denotes a cavity surface of the vacuum casting mold 1 held by the in-mold mold 51 and is in contact with the inner surface of the releasable resin film 2.

Numeral 52 denotes an injection mold having a convex core surface 54 corresponding to the convex shape of the resin product 5, which is formed of a steel block for a mold, and is provided on a movable side of the injection molding machine with a vacuum mold. 1
Are provided so as to face the surface on the cavity side. 53
Is a runner portion provided on the injection molding die 52 for injecting the releasable resin film 2, and the molten releasable resin 23 is injection-molded in the direction of the arrow. Numeral 54 denotes a convex core surface of the injection molding die 52, which is a surface for shaping the surface of the releasable resin film 2.

Next, the releasable resin film 2 is placed on the vacuum casting mold 1.
Will be described. The pre-update vacuum casting mold 1 is attached to the in-mold mold 51 in advance,
As described in FIG. 3, the release resin film 2 is removed by the eject pins 31. After the release resin film 2 is removed, the position of the tip of the eject pin 31 is changed to the position of the eject hole 3.
Is positioned so as to be located on the back side of the engaging portion 21 of FIG. Further, the injection molding die 52 is mounted so as to face the in-mold die 51, and the die configuration in the injection molding machine shown in FIG. 4 is completed. When the mold configuration is completed, the injection molding machine injects the polypropylene resin (melting temperature 200 ° C.) in the direction of the arrow shown in FIG.
And an engaging portion 21 are formed. More specifically, first, when a polypropylene resin (melting temperature: 200 ° C.), which is a material, is injected, the cavity-side surface 12 of the vacuum casting mold 1 and the injection molding mold are passed through the runner 53. The mold release resin film 2 is formed between the core portion 54 and the core surface 54, and the engaging portion 21 is formed between the tapered space 11 and the tip of the eject pin 31. The eject pin 3 is placed on the in-mold mold 51 at a position corresponding to the eject hole 3.
1 is provided, and the tip of the eject pin 31 is inserted to the position on the back side of the engaging portion 21.
Is closed, so that the injected resin is prevented from flowing into the eject hole 3 via the engaging portion 21. When the injection molding is completed, the mold structure is disassembled, and the vacuum casting mold 1 is taken out. And vacuum casting mold 1
The mold release resin film 2 engaged with the engagement portion 21 is formed on the cavity surface of the mold device 10 shown in FIG.
Is updated.

As described above, since the releasable resin film 2 of the molding apparatus 10 is in-mold molded and renewed in the vacuum casting mold 1 by using the injection molding machine, one injection molding mold is used. Using 52, a large number of molding apparatuses 10 having the same dimensions can be repeatedly prepared. Further, the vacuum casting mold 1 of the molding apparatus 10 can be repeatedly used without being worn, which is economical. The in-mold mold 51 is, for example, a resin product A (having a height of 180
mm) and the resin product B (having a height of 190 mm), the outer dimensions of the vacuum casting mold 1 can be standardized to a height of 260 mm. Even if the number of types is increased, a small number of types of in-mold dies 51 can be used, and the cost for mass production preparation can be suppressed.

As described above, the vacuum casting process according to the embodiment of the present invention is performed, and a pair of half mold devices 10, 10a having cavities lined with the release resin films 2, 2a are used. By doing so, it is possible to easily release the thermally cured resin product 5 from the release resin films 2 and 2a. In addition, it is possible to prevent the resin product 5 from being in close contact with the molding devices 10 and 10a and causing a problem on the surface of the resin product 5. That is, it is possible to omit troublesome operations such as the application of the release agent and the cleaning operation for removing the residual release agent before the application, thereby improving the operation aspect. In addition, the mold release resin films 2 and 2a are hardly damaged by abrasion or the like, and the molding devices 10 and 10a are repeatedly used several tens of times. And the molding device 10,
After 10a is repeatedly used several tens of times, that is, after the releasable resin films 2 and 2a are worn out due to abrasion or the like and cannot withstand use, the eject pins 31 are used from the vacuum casting molds 1 and 1a. The release resin films 2 and 2a are removed, and again,
The releasable resin films 2 and 2a are renewed on the vacuum casting dies 1 and 1a using an injection molding machine. In the mass production process, it is necessary to prepare a number of molding apparatuses 10 and 10a according to the production amount. However, the renewal (or new creation) of the mold release resin films 2 and 2a of the molding apparatuses 10 and 10a is performed by an injection molding machine. Therefore, it is sufficient to prepare an injection mold for each type of the resin product 5 and a common in-mold mold 51, so that the cost can be suppressed. In this example, the engaging portion is formed in a tapered shape. However, the shape is not particularly limited as long as the engaging portion is engaged with the ejection hole.

[0026]

As described above in detail, according to the present invention, since the mold release resin film is provided on the inner surface of the vacuum casting mold apparatus, the resin product is added to the mold when the resin product is taken out of the mold. Does not cause close contact with the mold, and the moldability of the release resin film is good for the mold.
The work involved in applying the release agent, which has been conventionally performed, can be omitted, and the cost of the mass production process is reduced.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a configuration of a molding apparatus according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram illustrating a configuration of a molding apparatus during vacuum casting according to an embodiment of the present invention.

FIG. 3 is an explanatory diagram illustrating removal of a release resin film according to the embodiment of the present invention.

FIG. 4 is an explanatory diagram illustrating a forming apparatus of a molding apparatus according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Vacuum casting mold 2 ... Releasable resin film 3 ... Eject hole 4 ... Injection runner part 10 Mold device 21 Engagement part

Claims (4)

[Claims] 1. A mold apparatus for molding a resin product, comprising: a mold having a cavity; and a mold release resin formed on a cavity surface of the mold and having a resin that is non-bonding to the resin in the resin product. A molding apparatus comprising: a film; and an engaging portion provided on the back side of the release resin film is engaged with the mold. 2. The molding apparatus according to claim 1, wherein an ejection hole is formed in the mold from the back surface to the cavity, and the engagement portion is engaged with the ejection hole. . 3. A mold having a cavity, a mold release resin film formed on a cavity surface of the mold and having a resin that is not bonded to a resin in the resin product, and from a back surface of the mold. An ejection hole formed over the cavity, and a manufacturing apparatus of a molding apparatus in which an engagement portion provided on the back side of the release resin film is engaged with the ejection hole, wherein the ejection hole is provided through the ejection hole. It has an eject pin projected from the back surface of the mold toward the cavity, the engaging portion is projected by the eject pin, and the release resin film is removed from the cavity surface of the mold. Characteristic molding equipment manufacturing equipment. 4. A mold having a cavity, a mold release resin film formed on a cavity surface of the mold and having a resin that is non-bonding to a resin in the resin product, and from a back surface of the mold. An ejecting hole formed over a cavity, and a manufacturing apparatus for a molding device, wherein an engaging portion provided on the back side of the release resin film is engaged with the ejecting hole, provided on a resin injection side. An injection-molded core mold having a core surface corresponding to the shape of the releasable resin film; an eject pin protruding from a back surface of the mold toward a cavity through the eject hole; A holding mold provided on a side facing the molding core mold and holding the back side of the mold in-mold, and a tip of the eject pin is located at a position corresponding to a back side of the engaging portion. Status A resin is injected from the injection-molded core mold to the core surface, the cavity surface of the mold held in-mold by the holding mold, the core surface of the injection-molded core mold, and the eject pin. Wherein the mold release resin film and the engagement portion are formed in a space surrounded by a tip of the mold device.