JP2002240105A - Mold apparatus for molding and method for molding using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mold apparatus for molding capable of smoothly filling a resin by degassing in a filling step and mold releasing a molding without difficulty in a mold releasing step. SOLUTION: A slit-like gas passage 15 communicating within the cavity 3 is provided at the movable mold 2. The passage 15 is connected to a sucking/ exhausting means 21. In a step of filling the resin J in the cavity 3, a gas in the cavity 3 is sucked from the passage 15 by the means 21, and the cavity 3 is degassed. Thus, the resin J smoothly flows to be filled in the cavity 3. When the molding is released from the mold, the gas is blown from the passage 15 to the molding to expedite mold releasing. Since the gas is blown, the molding is not deformed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molding die apparatus for molding a resin and a molding method using the same.

[0002]

Generally, in molding a resin using a molding die apparatus, a cavity is formed between molds that can be opened and closed with each other, and a molten resin is filled in the cavity when the mold is closed. This is cooled and solidified, and the mold is opened and released to obtain a molded product having a cavity shape. In the filling process in which the molten resin is filled, the cavity is filled with air and other gases. Gas is generated from the melted resin. The gas generated from the molten resin and the air in the cavity before filling (hereinafter, simply referred to as gas) are compressed together with the filling of the molten resin, hinder the molten resin and cause a filling failure.

Therefore, as one method for preventing the above-described filling failure, as shown in FIG. 6, a plurality of gates 102 for filling a molten resin into a cavity 101 are provided, and the shape of the cavity 101 is reduced. Are arranged at the positions corresponding to the above, the molten resin can flow evenly as shown by the arrows, thereby preventing defective filling.

However, in some cases, only by increasing the number of gates 102, defective filling cannot be prevented. For example, when the molded product is a thin thin molded product, defective filling is likely to occur. Also in FIG. 6 described above, if the molded product is thin, gas accumulates in the central portion distant from the gates 102, 102,... For this reason, in the example of FIG. 6, by providing the gas releasing means 103 at the center, the gas can be discharged from the cavity 101 to the outside of the cavity 101 and the filling failure can be eliminated. For example, Japanese Patent Application Laid-Open No. 4-72
For example, a mold material of a porous mold known from Japanese Patent Application Publication No. 004-004 is used. This mold member is formed by powder sintering, and fine communication holes are uniformly dispersed therein, and gas can be exhausted to the outside from the surface forming the cavity through the communication holes.

However, since the inside of the mold is porous and has a shape in which the communication holes are dispersed, there is a problem that the molten resin enters the communication holes from the surface forming the cavity and causes clogging. Yes, when clogging occurs,
Gas cannot be exhausted to the outside. Further, since the resin enters the fine communication hole and hardens, the resin that has entered the communication hole is difficult to remove, and clogging cannot be eliminated.

By the way, in this type of molding die apparatus,
When releasing the molded product in which the molten resin has been cooled and solidified, a protruding pin is used. However, a thin molded product has a problem that the portion pressed by the protruding pin is easily deformed. Therefore, in order to disperse the pressing force by the protruding pins during release, a plurality of protruding pins are used. However, even if the number of protruding pins that push against the molded product is increased, for example, 0.3
There is also a problem that a pressed portion is deformed in a thin molded product such as a millimeter or less.

Therefore, the present invention is intended to solve such a problem. In the filling step, the resin can be smoothly filled by degassing, and the molded article can be easily released in the releasing step. It is an object of the present invention to provide a molding die apparatus and a molding method using the same, which are less likely to cause clogging in a gas vent portion of a cavity and suitable for molding a thin molded article.

[0008]

According to a first aspect of the present invention, there is provided a molding die apparatus comprising a plurality of molds which can be opened and closed with each other and form a cavity therebetween when the mold is closed, and the cavity is filled with resin. And a slit-shaped gas passage provided in one of said mold bodies and communicating with said cavity, and a gas vent for removing gas in said cavity by said slit-shaped gas passage. And a suction / discharge means for blowing gas into the cavity.

Therefore, at the time of molding, a plurality of molds are closed to form a cavity therein, and the cavity is filled with resin. In the process of filling the cavity with resin, gas in the cavity is sucked from the slit-shaped gas passage by suction / discharge means. To degas,
This eliminates the resistance associated with gas compression in the cavity when filling the resin, and allows the resin to flow smoothly and fill the cavity. Then, after the resin in the cavity is solidified, the mold is opened, and the molded product is released. At this time, gas is blown out from the slit-shaped gas passage and blown onto the molded product, so that the release is promoted, and the gas is released. Since it is sprayed, the molded product does not deform. Also, in the case of using a projecting pin together with the release pin, by performing gas blowing, the projecting pin can be released by pressing the molded product with a small force, so that deformation of the molded product due to the projection pin can be prevented. . Further, the slit-shaped gas passage not only sucks the gas from the inside of the cavity but also blows the gas into the cavity at the time of releasing the mold, so that the gas blowing can prevent the gas passage from being clogged. Also, even if the resin enters the gas passage,
Since the gas passage has a slit shape, it is easy to remove.

According to a second aspect of the present invention, in the molding die apparatus of the first aspect, a plurality of the slit-shaped gas passages are provided at intervals in a width direction. Therefore, the gas can be smoothly vented by the plurality of slit-shaped gas passages, and at the time of release, the molded product can be released by blowing gas over a wide range.

Further, according to a third aspect of the present invention, in the molding die apparatus of the second aspect, a nest made of a plurality of block members is provided in the one mold body, and a gap formed between the block members is provided. The slit-shaped gas passage is constituted. Therefore, in a nest formed by assembling a plurality of block members, a gas passage is formed between the block members, and the nest may be provided in the mold, so that the slit-shaped gas passage can be formed extremely easily.

According to a fourth aspect of the present invention, in the molding method using the molding apparatus of the first aspect, the cavity is vented through the slit-shaped gas passage in a filling step of filling the cavity with a resin. A molding method in which a gas is blown from a slit-shaped gas passage to the molded product in a mold release step of releasing the molded product from the one mold.

Therefore, at the time of molding, a plurality of molds are closed to form a cavity therein, and the cavity is filled with a resin. To degas,
Thus, there is no resistance due to gas compression, and the resin flows smoothly and fills the cavity. Then, after the resin in the cavity has solidified, open the mold, release the molded product,
At this time, the gas is blown out from the slit-shaped gas passage and blown to the molded product, so that the mold release is promoted and the gas is blown, so that the molded product is not deformed and is suitable for molding of a thin-walled molded product. It is a molding method.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the molding die apparatus of the present invention will be described below with reference to FIGS.
In the figure, reference numeral 1 denotes a fixed mold forming the outer surface of a molded product;
Is a movable mold for forming the inner surface of the molded article. The fixed mold 1 and the movable mold 2 which are mold bodies move up and down in the figure to open and close each other, and when the mold is closed, the molded article-shaped cavity 3
Is formed. The fixed mold 1 has a gate 4 opening to the cavity 3, and the gate 4
And the cavity 4 is filled with molten resin from the gate 4. On the other hand, the movable mold 2
Has a protruding pin 6 whose tip faces the cavity 3. Before the protruding pin 6 protrudes, its tip is flush with the surface of the cavity 3 and its tip protrudes from the surface of the cavity 3 to release the molded product.

The movable mold 2 has a movable mold plate 11 and a movable receiving plate 12 attached to the back surface (the lower surface in the figure) of the movable mold plate 11. The nested mounting portion 13 is an opening communicating the cavity 3 side of the movable mold plate 11 with the back surface.
A nest 14 is provided on the nest 13, and a plurality of slit-shaped gas passages 15, 15,... Are formed at equal intervals in the width direction. As shown in FIG. 3 and the like, the nest 14 is made up of a plurality of blocks 16, 17 and 18, and one side of the block 16
On the other side, the slit forming groove portion 19, the larger intermediate groove portion 19A and the enlarged groove portion 19B are communicated with each other in order from the cavity 3 side, and the intermediate block material 17 has one side surface which is flat and the other side surface has a cavity. From the third side, a slit forming groove portion 19A, an intermediate groove portion 19B, and an enlarged opening portion 19C are provided, and the block member 18 on the other side has a groove portion 19D on one side surface corresponding to the enlarged opening portion 19C. The slit forming groove 19 is formed by machining or the like, and the slit forming groove 19 serves as a gap between the block members 16, 17, 18. Then, the individual block members 16, 17, 18 shown in the sectional view of FIG.
The slit-shaped gas passage 15 opening to the cavity 3 is formed between the block member 16 and the adjacent block members 16, 17, 18, and an enlarged groove 19 B is formed on the movable receiving plate 12 side of the insert 14.
A communication space 20 is formed in which the opening 19C and the groove 19D communicate with each other. As shown in FIG. 2, the width W of the slit gas passage 15 is 30 μm or less, preferably 10 μm or less.
It is about 20 microns.

In the communication space 20, suction and discharge means such as a pump is provided.
21 is connected, and the suction and discharge of the gas in the cavity 3 and the blowing of the gas into the cavity 3 are performed by the suction and discharge means 21 in accordance with the control of the control means 22 in accordance with the molding process by the molding die. In the drawing, reference numeral 23 denotes a passage connecting the communication space 20 and the suction / discharge means 21, and is formed in the movable receiving plate 12.

As shown in FIG. 5, a molded product 31 having the shape of the cavity 3 is provided with the slit-shaped gas passage 15.
Has a thin box shape having a surface portion 32 orthogonal to the surface portion and a wall portion 33 formed around the surface portion 32, and the thickness T of the surface portion 32 is 0.3 mm or less.

Next, a molded product using the molding die apparatus
To explain the molding of 31, the fixed mold 1 and the movable mold 2 are closed, and the molten resin J is filled into the cavity 3 from the gate 4 (filling step). In this filling step, the control means 22
As a result, the suction / discharge means 21 is operated, and the gas (gas generated from the air and the molten resin) in the cavity 3 is sucked from the slit-shaped gas passage 15, and the suction is stopped almost simultaneously with the completion of the filling. By degassing in this manner, the gate 4
The molten resin J filled from above flows smoothly through the entire cavity 3, good filling is performed, and generation of residual stress in the molded product 31 is also prevented. After the resin filled in the cavity 3 is cooled and solidified, the fixed mold 1 and the movable mold 2 are opened, and in the next release step, the ejection pin 6 is operated, and when the molded product is pressed, almost simultaneously or slightly. First, the suction / discharge means 21 is operated by the control device 22 to blow out gas into the cavity 3 through the slit-shaped gas passage 15. In this case, the gas is generally air, and the gas blown out from the plurality of slit-shaped gas passages 15 hits the surface 32 of the molded product 31 almost orthogonally, and the molded product 31 is pushed in the releasing direction.
Only the portion pressed by the protruding pin 6 is not concentrated and receives a force, and the portion hit by the protruding pin 6 is prevented from being deformed. Then, gas is blown from the slit-shaped gas passage 15 in a direction substantially along the projecting direction of the projecting pin 6.

As described above, according to the present embodiment, the cavities 3 can be opened and closed with each other when the mold is closed.
A plurality of molds forming a fixed mold 1 and a movable mold 2,
A molding die apparatus for molding a molded product 31 by filling a cavity 3 with a molten resin J, wherein the movable die 2 is one mold.
And a slit-shaped gas passage 15 communicating with the inside of the cavity 3.
Since there is provided a suction / discharge means 21 for degassing the gas inside and discharging the gas into the cavity 3, the fixed mold 1 and the movable mold 2 are closed during molding to form the cavity 3 inside. Then, in the step of filling the cavity 3 with the resin J, the gas in the cavity 3 is sucked out of the slit-shaped gas passage 15 by the suction / discharge means 21 to release the gas. The resistance caused by the compression is eliminated, and the resin J flows smoothly and the cavity 3
Even if it is a thin-walled molded product 31 having a thickness (thickness) of 0.3 mm or less, a good molded product 31 can be obtained. Then, after the resin in the cavity 3 is solidified, the mold is opened, and the molded product 31 is released from the mold.
By blowing gas from 15 and blowing it on the molded product 31,
Since the release is promoted and the gas is blown, the molded article 31 does not deform. Also, in the case of using the protruding pin 6 in the mold release, the protruding pin 6 can be released by pressing the molded product 31 with a small force by performing gas blowing. Deformation can be prevented. Further, the slit gas passage 15 not only sucks the gas from the cavity 3 but also blows the gas into the cavity 3 at the time of releasing the mold, so that the gas blowout can prevent the gas passage 15 from being clogged. Further, even if the resin J enters the gas passage 15, the gas passage 15 has a slit-like shape, so that there is an advantage that the resin J can be easily removed. Of course, clogging can also be prevented by blowing gas from the gas passage 15 at the time of adjustment of the apparatus other than the molding step.

Further, as described above, in this embodiment, claim 2
Since a plurality of slit-shaped gas passages 15 are provided at intervals in the width direction, gas can be smoothly vented, and at the time of mold release, gas is blown over the molded product 31 over a wide range. Can be attached and released.

As described above, according to the present embodiment, claim 3
In correspondence with the above, a movable mold 2 as a mold body is provided with a nest 14 composed of a plurality of blocks 16, 17, 18, and a slit forming groove 19 formed as a gap between the blocks 16, 17, 18. Since the slit-shaped gas passage 15 is formed by the nesting method, a plurality of block members 16, 17, 18 are assembled.
In 14, a gas passage 15 is formed between the block members 16, 17, 18, and the nest 14 may be provided in the movable mold 2, so that the slit-shaped gas passage 15 can be formed extremely easily.

As described above, in this embodiment, in the filling step of filling the cavity 3 with the resin J, the gas in the cavity 3 is vented through the slit-shaped gas passage 15, and Since gas is blown from the slit-shaped gas passage 15 to the molded product 31 in a mold release step of releasing the molded product 31, the fixed mold 1 and the movable mold 2 are closed to form the cavity 3 therein during molding. In the step of filling the cavity 3 with the resin J, the slit-shaped gas passage 15 is
From the cavity 3 to degas the gas,
Thus, resistance due to gas compression in the cavity 3 can be eliminated, and the resin J can flow smoothly and fill the cavity 3. Then, after the resin J in the cavity 3 is solidified, the mold is opened and the molded product 31 is released. At this time, gas is blown out from the slit-shaped gas passage 15 and the molded product 31 is released.
, The mold release is promoted and the gas is blown, so that the molded product 31 is not deformed,
A molding method suitable for molding of 31 is obtained.

Also, as an effect of the embodiment, since the middle block member 17 used for the nest 14 has the same shape, the number of the slit-shaped gas passages 15 is set by changing the number of the block members 17. be able to. Also nested 14
Can be disassembled by assembling blocks 16, 17, and 18, so that the nest 14 can be detachably attached to a nest mounting portion 13 formed on the movable mold 2 which is one of the molds. Since it has been mounted, the nest mounting part
The resin J that has entered the slit-shaped gas passage 15 or the like by dividing the block 13, the insert 14, and the blocks 16, 17, and 18 can also be removed.

It should be noted that the present invention is not limited to the above embodiment, and various modifications can be made. For example,
The gate may be a cold runner type that takes a plurality of molded products and may be a side gate type, and the type, number and arrangement of the gates can be appropriately selected. Preferably, a slit-like passage is provided at a position away from the gate. In the case where the protruding pins are used, the number, arrangement, driving means, and the like can be appropriately selected. Further, in the embodiment, an example is shown in which gas is discharged and gas is blown out by switching one suction and discharge means. However, the suction and discharge means may be provided with separate means for degassing and means for blowing gas. Good.

[0025]

According to the first aspect of the present invention, there is provided a molding die apparatus comprising:
A slit-shaped gas passage provided in one of the mold bodies and communicating with the inside of the cavity; and a suction / discharge means for performing gas release for discharging gas in the cavity and gas blowing for blowing gas into the cavity by the slit-shaped gas passage. Because we have
The resin can be smoothly filled by degassing in the filling process, the molded product can be easily released in the mold release process, and clogging does not easily occur in the degassing part, and molding of thin molded products Can be provided.

According to a second aspect of the present invention, in the molding die apparatus of the first aspect, since the plurality of slit-shaped gas passages are provided at intervals in the width direction, the gas can be smoothly vented. In addition, at the time of release, the molded product can be released by blowing gas over a wide range.

Further, according to a third aspect of the present invention, in the molding die apparatus of the second aspect, a nest made of a plurality of block members is provided in the one mold body, and a gap formed between the block members is provided. Since the slit-shaped gas passage is formed, the slit-shaped gas passage can be formed extremely easily.

According to a fourth aspect of the present invention, in the molding method using the molding die apparatus of the first aspect, the cavity is vented through the slit-shaped gas passage in a filling step of filling the cavity with a resin. Since the molding method in which a gas is blown from the slit-shaped gas passage to the molded article in the mold release step of releasing the molded article from the one mold body, the resin is smoothly filled by degassing in the filling step. The molded product can be released smoothly in the release process.
Moreover, it is hard to cause clogging in the degassing part,
A molding method using a molding die apparatus suitable for molding a thin molded article can be provided.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing the vicinity of a cavity before resin filling, showing one embodiment of a molding die apparatus of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG. 1;

FIG. 3 is a sectional view of the nest before assembling.

FIG. 4 is a cross-sectional view of the vicinity of the cavity after resin filling according to the first embodiment.

FIG. 5 is a perspective view of the molded product according to the first embodiment;

FIG. 6 is a schematic front view of a conventional mold apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fixed mold (mold) 2 Movable mold (mold) 3 Cavity 15 Slit gas passage 21 Suction / exhaust means 31 Molded product

Claims (4)

[Claims] 1. A molding die apparatus, comprising: a plurality of molds which can be opened and closed with each other and form a cavity therebetween when the mold is closed, and wherein the cavity is filled with a resin to mold a molded product. A slit-shaped gas passage provided in one of the mold bodies and communicating with the inside of the cavity; and a suction / discharge means for performing gas release for discharging gas in the cavity and gas blowing for blowing gas into the cavity by the slit-shaped gas passage. A molding die apparatus, comprising: 2. A plurality of slit-shaped gas passages are provided at intervals in a width direction.
The molding die apparatus as described in the above. 3. The mold according to claim 2, wherein a nest made of a plurality of block members is provided in the one mold, and the slit-shaped gas passage is formed by a gap formed between the block members. Molding equipment for molding. 4. A molding method using a molding die apparatus according to claim 1, wherein a gas in the cavity is vented through the slit-shaped gas passage in a filling step of filling the cavity with a resin. A molding method using a molding die apparatus, wherein a gas is blown from a slit-shaped gas passage to the molded product in a mold release step of releasing the molded product from the mold.