JP2001198958A - Injection mold and injection molding method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an injection mold capable of obtaining highly accurate molded articles without generating a defective molded article when a large number of molded articles of a different kind are molded. SOLUTION: In an injection mold having a plurality of cavities, a means for cutting off the supply of a molten resin to the respective cavities, a means for supplying air to the cavities, a means for detecting the filling with the resin in a flow terminal region at every cavity and a means for controlling the cutting-off means and the gas supply means on the basis of detection are provided.

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 used for performing multi-cavity molding and an injection molding method using the injection molding die. The present invention relates to a multi-cavity injection molding mold for forming a cavity, and an injection molding method using the injection molding mold.
The aim is to increase the accuracy of so-called family molding.

[0002]

2. Description of the Related Art Conventionally, in family molding in which different types of molded products are molded with one mold, it is extremely difficult to simultaneously obtain the accuracy of each molded product because the shape of each cavity is different.

[0003] First, the difference in the shape means that the filling time of each resin is different, and after filling is completed in a certain cavity, a short circuit occurs in another cavity.

[0004] After one cavity is completely filled, the resin pressure in that cavity is in a packed state, which tends to flow into unfilled cavities and tends to flow sequentially into unfilled cavities.

[0005] However, when setting conditions for enabling the filling of unfilled cavities, for example, by increasing the filling pressure, an overpressure is applied to the filled cavities, and the overpacking is caused. Problems such as mold release failure and burrs are likely to occur.

There is also a means for changing the gate shape for each cavity so as to balance the filling by changing the shape of the gate for each cavity. However, a difference occurs in the gate seal and a difference occurs in the transmission of pressure in the pressure-holding stage.

There is a means using gas assist molding in which this pressure-holding step is performed by pressing with gas. Even if gas introduction means is provided in each cavity so that the pressure can be set for each cavity, each gas is introduced. The gas that has passed through the gate affects other cavities, and the mutual gas interferes with each other, so that a desired good molded product cannot be obtained.

In Japanese Unexamined Patent Publication No. 9-239788, a gas pressure shutoff mechanism is provided at a gate or a runner so as to prevent gas from affecting each cavity. This can solve the problem during packing, but it does not solve the problem of filling balance.Family molding of molded products with little difference in molded product thickness etc. is possible. Difficulties remain in the family molding of molded articles with thickness differences.

[0009]

As described above, as described above,
The difficulty of the family molding lies in the balance between the resin filling and the pressure-holding stage. Therefore, the filling stage,
Issues at each stage such as the dwelling stage are summarized below.

First, in the filling stage, the time of full filling differs for each cavity. If the thickness of the different molded products is the same, the time for full filling is determined by the size of the molded products, and the respective cavities are filled as needed. In this case, the influence of pressurization due to excessive resin on the first fully filled portion is small.

However, in the case of a plurality of molded products having different thicknesses, the filling conditions must depend on the molded products having the minimum thickness. Since the resin flows in a place where the resin easily flows, a thick molded product is filled with a large amount of resin. In order to fill a thin molded product, it is necessary to take measures such as increasing the pressure and increasing the resin filling speed.

In this case, it is difficult to flow into a thin molded product,
When the ease of pressurization after full filling of a thick molded product is reduced, the latter is more likely to be easier. As described above, problems when excessive pressure is applied to a molded product include the occurrence of burrs, the problem of mold release due to overpacking, and the problem of accuracy due to residual stress.

On the other hand, a problem at the dwelling stage is whether it is possible to appropriately dwell each cavity.
As described above, the holding pressure cannot be appropriately increased depending on the shape of the molded product and the gate shape of each cavity.

As described above, it is an object of the present invention to eliminate excessive pressurization of a molded article during flow and to improve inappropriate pressurization of the molded article in a dwell stage.

Therefore, in order to solve such a conventional problem, an object of the present invention is to provide a high-precision molded product which does not generate defective products when performing multi-piece production of different types. And to provide an injection molding method using the injection mold.

[0016]

According to the present invention, there is provided, in accordance with the present invention, an injection mold having a plurality of cavities. Means for interrupting the supply of resin, means for supplying gas to the cavities, means for detecting resin filling in the flow end region for each of the cavities, and the shutoff means and gas supply means based on the detection. Control means.

Further, the injection mold of the present invention is characterized in that the blocking means is a gate valve pin mechanism.

Further, the injection mold of the present invention is characterized in that the blocking means is a gate cut pin mechanism.

Furthermore, the injection molding die of the present invention comprises:
The detecting means is a pressure sensor provided in a flow end region of each of the cavities.

The injection molding die of the present invention is characterized in that the control means feeds back a value detected by the detection means to control the cutoff means and the gas supply means.

Further, the injection mold of the present invention is characterized in that the pressure value of the pressure sensor is in a range of 20 kgf / cm ² or more.

Further, according to the injection molding method of the present invention, there is provided an injection molding method for performing injection molding using an injection mold having a plurality of cavities. When the pressure in the flow end region of the cavity reaches a predetermined value, the control means activates the shut-off means of each of the cavities to stop the supply of the resin, and then operates the control means. A gas is supplied to the cavity after the shutoff means is closed.

Furthermore, in the injection molding method of the present invention, the shutoff means is a gate valve pin mechanism.

The injection molding method according to the present invention is characterized in that the blocking means is a gate cut pin mechanism.

Further, in the injection molding method of the present invention, the detecting means is a pressure sensor provided in a flow end region of each of the cavities.

Further, the injection molding method of the present invention is characterized in that the control means controls the shutoff means and the gas supply means by feeding back the value detected by the detection means.

In the injection molding method according to the present invention, the pressure value of the pressure sensor is in a range of 20 kgf / cm ² or more.

[0028]

According to the present invention having the above-described structure, an injection molding die and an injection molding method using the injection molding die are provided for each of a plurality of cavities. Alternatively, a gate cut pin, a gas nozzle for gas injection, and an injection molding die having a pressure sensor at the resin flow end of each cavity are used, and the pressure detected by the pressure sensor installed at the end, respectively, It is possible to control resin filling and gas filling by a control device for each cavity.

As described above, in the injection molding, excessive pressurization at the time of flow particularly occurs due to a difference in wall thickness of a molded product.

It is difficult to avoid a difference in cavity filling time between the cavities due to the difference in the size of the molded product. When filling one cavity after filling another cavity, the pressure in the resin flow during that time,
It is necessary to shut off so as not to affect the already full cavity. In the present invention, the supply of the resin to the cavity is stopped every time the cavity is fully filled.

In the first embodiment of the present invention, a pin point gate is adopted as a gate mechanism, and a valve pin is provided for each cavity so that the gate can be shut off. The valve pins of the shut-off mechanism are operated by different drive systems, respectively, and can be operated at different timings.

Each of the cavities is provided with a pressure sensor in a resin filling terminal region. The pressure sensor confirms resin filling for each cavity and recognizes the value indicated by the pressure sensor, thereby activating the feedback mechanism and operating the valve pin.

With the above-mentioned mechanism, the gate is blocked after full filling while checking the resin filling for each cavity, thereby preventing the influence of resin pressure on the cavity after full filling.

Next, the appropriate pressurization (holding pressure) for each cavity, which is the subject of the pressure holding stage, will be described.

As described above, since the supply of the resin is shut off by the valve pin after the filling of the resin, the holding pressure by the resin is not considered thereafter. In the present invention, a gas nozzle pin for gas injection is provided for each cavity, and a gas pressure can be controlled for each cavity. Since the gas is injected after the valve pin is shut off, the gas does not flow backward from the gate. In addition, since conditions such as gas pressure can be individually set for different shapes for each cavity, it is not necessary to consider the balance of gates and shapes of each cavity.

Further, in the second embodiment of the present invention, a gate cut pin for pressing or cutting a runner portion or a gate portion for supplying resin to each cavity is provided, and the resin is supplied to each cavity. It has a structure that can be shut off. This resin cut gate cut pin
They operate in different drive systems and can operate at different timings.

Each cavity is provided with a pressure sensor in a resin filling terminal region. A pressure sensor confirms resin filling for each cavity and recognizes a value indicated by the pressure sensor, thereby activating a feedback mechanism and operating a gate cut pin.

With the above-mentioned mechanism, the gate is closed or the runner is pressed after full filling while checking the resin filling for each cavity to prevent the resin pressure from affecting the cavity after full filling. .

Next, the appropriate pressurization for each cavity, that is, the dwelling pressure, which is the subject of the dwelling stage, will be described.

As described above, since the supply of the resin is cut off by the gate cut pins after the filling of the resin, the pressure holding by the resin is not considered after that. In the present invention, a gas nozzle pin for gas injection is provided for each cavity, and a gas pressure can be controlled for each cavity. Further, the gas injection can be started after the gate is cut or the runner portion is compressed by advancing the gate cut pin, and can be set as a delay time from the start of operation of the gate cut pin. After the gate cut pin advances and the resin supply to the cavity is cut off,
Since the gas is injected, the gas does not flow backward from the gate. Further, since conditions such as gas pressure can be individually set for different shapes for each cavity, it is not necessary to consider the balance of the gate and shape of each cavity.

Other objects, features and advantages of the present invention will become apparent from the following detailed description of several embodiments of the present invention with reference to the accompanying drawings.

(Example 1) FIG. 1 is a vertical vertical sectional view showing an injection molding die that best illustrates the features of the present invention.

FIG. 1 shows an example of an injection mold according to the present invention.
Is capable of molding, for example, four molded articles arranged in a cross shape, and here only two vertical cavities are shown.

As shown in the figure, the injection mold 1 of the present invention comprises a fixed mold 2 and a movable mold 3, and the fixed mold 2 is composed of a fixed mounting plate 4 and a fixed mold. A movable mold 3, a pressure receiving plate 7, a spacer block 8, a movable mounting plate 9, an ejector plate 10, a first control device 11, and a second movable mold 3. Control device 12
It is roughly constituted from.

Further, a nozzle (not shown) as an injection port for injecting the molten resin into the fixed mold 2.
, A sprue member 13 having a sprue 13b inserted into the opening 13a, gates 14 and 15, and a gate 1
Valve pins 16, 1 for opening and closing 4 and 15 respectively
7 and cylinders 18, 1 of these valve pins 16, 17.
9 are provided. In addition, these cylinders 18, 1
First and second control devices 11 and 12 such as a gas controller and the like for operating the power supply 9 are provided.

Furthermore, the movable mold 2 and the fixed mold 3
Are provided with a plurality of cavities for molded articles of different shapes.
Only one cavity 20, 21 is shown.

In order to control and operate the cylinders 18 and 19 of the valve pins 16 and 17 for opening and closing the gates 14 and 15, first and second control devices 11 and 12 composed of gas controllers are provided. 20, 2
1 is provided with gas nozzles 22 and 23 for introducing gas, respectively, and is configured to receive gas supply from a gas controller which is the second control device 12. Pressure sensors 26 and 27 are respectively installed at the ends of the flow paths 24 and 25 of the cavities 20 and 21, and the pressure values detected by the pressure sensors 26 and 27 are fed back to the first control device 11. , A signal for operating the cylinders 18, 19 is sent from the first control device 11.

The first and second control devices 11,
The gas controller constituting 12 can set a plurality of conditions, and the cavities 20 and 21 may be connected to different controllers. Further, the gas controller as the second control device 12
Is connected to the controller of the control device 11 to receive a signal for starting gas injection. Flow path 2
Reference numerals 4 and 25 can be manufactured so as to also serve as ejector pins, so that molded products formed in the cavities 20 and 21 can be discharged and taken out.

Here, the molten resin injected from the nozzle of the injection molding machine is applied to the sprue 13 b of the sprue member 13.
Through hot runners 28 and 29 and gate 1 respectively
It is injected into cavities 20 and 21 through 4 and 15. The gates 14 and 15 are pin gates, and are opened and closed by valve pins 16 and 17, respectively. These valve pins 16 and 17 are movable cylinders 18, 1
9 and is operated by a first controller 11 such as a gas controller.

FIGS. 2 to 6 show an example of family molding of four parts according to the present invention. As shown in FIGS. 2 to 6, the four components have different shapes and different wall thicknesses. The shapes of these four parts are clearly shown in FIGS. That is, the shape 1 is shown in FIG.
As shown in (A) and (B), it has a bottomed cylindrical shape and a plate thickness of 2.5 mm. The shape 2 has a bottomed rectangular shape as shown in FIGS. 4A and 4B, and has a plate thickness of 2.0 mm. Furthermore, shape 3 is
As shown in FIGS. 5 (A) and 5 (B), it has an L-shaped cross-sectional shape and a plate thickness of 1.5 mm. Furthermore, as shown in FIGS. 6A and 6B, the shape 4
It has an elongated flat plate shape and a thickness of 1.0 mm.
Also, when these four parts are molded simultaneously, there is naturally a difference in the resin filling time. The thicker the resin, the lower the flow resistance and tends to flow. Therefore, each cavity is filled with the resin in the order of shape 1, shape 3, and shape 4 from shape 1 shown in FIG.

Each of the valve pins 1-A, 2- shown in FIG.
The resin flows into the cavity of each shape from directions A, 3-A and 4-A. The flow of the resin in each shape is converted into pressure sensors 1-C, 2-C, 3-C, which are installed at the ends of the flow paths 1-B, 2-B, 3-B, 4-B of each cavity.
It measures by 4-C.

In the main molding, the shapes 1 and 2 are filled almost simultaneously. Before filling the cavities of both shapes, the respective pressure sensors 1-C and 2-C detect the pressure of the resin and rise.

FIG. 7 shows a pressure history measured by the pressure sensor 1-C. At point a in FIG. 7, the pressure sensor 1-
C starts to rise. At this time, the valve pin 1 shown in FIG.
If −A is left open, an impact pressure as shown by the broken line b in FIG. 7 is exerted, which adversely affects the quality of the molded product such as generation of burrs and deformation due to residual stress. FIG.
When the pressure has increased to the point c, the valve pin 1-A
The gate is closed by moving forward (FIG. 2). At this time,
When the pressure is detected, the valve pin 1-A is activated, and a time lag occurs until the gate is closed. Care must be taken because impact pressure builds up during this time and may affect quality. In such a case, it is necessary to set the pressure sensor not at the end of the resin flow path but at a position slightly upstream from the end to try to avoid impact pressure.

In this molding, when the molding is performed without actually shutting off the gate for each cavity, the pressure applied to the cavity of the shape 1 reaches 300 kgf / cm ^2. The resin can be filled at a pressure of 90 kgf / cm ² , and an excessive rise in cavity pressure can be prevented by shutting off the gate.

In the shape 1, since the bottom surface is the final filling position and the side surface is an annular surface and it is difficult to dispose the pressure sensor, the pressure sensor 1-C is installed at the position of the flow path 1-B on the upper surface. I have. Therefore, in the shape 1, it is necessary to set the feedback value by grasping the flow time of the resin from this position to the end and the pressure behavior at this position.

It takes about 0.2 seconds for the pressure to be detected and fed back to activate the valve pin 1-A and shut off the gate. Therefore, feedback is applied at a pressure value 0.2 seconds before each cavity is filled.

In each of the shapes 1 and ² , feedback is applied when the resin pressure reaches 40 kgf / cm ² . The cavity pressure during filling of shape 1 is 90k
gf / cm ² and shape 2 is 130 kgf / cm ² .

After the valve pins 1-A and 2-A of the shapes 1 and 2 successively shut off, the filling of the other shapes 3 and 4 proceeds.

FIG. 8 shows the pressure histories of the pressure sensors set in shape 1 to shape 4 in a superimposed manner. As can be seen from this pressure history, the shape 3 is 190 kgf
/ Cm ² , the valve pin 3-A starts to advance, the pressure at the time of filling is about 300 kgf / cm ² , and the shape 4 is 1
At 70 kgf / cm ² , the advance of the valve pin 4-A is started, and the pressure at the time of filling is about 380 kgf / cm ² .

As described above, each cavity could be filled with the resin at an appropriate pressure.

At this time, it is also important to gradually change the speed of resin injection as the gate of one cavity is shut off. Since the thicknesses of the shapes 1, 2, 3, and 4 in FIG. 2 are different, the injection speed is changed to an appropriate injection speed, and an appropriate filling condition is set.

The gas introduction position is located near the lower surface of the valve pin 1-A, 2-A, 3-A, 4-A at the gate position in FIG. 2, and the delay timer set for each cavity operates. Then, under each set gas condition, gas injection and holding pressure are performed.

FIG. 9 shows the gas filling pressure,
The process until cooling is shown for each cavity. In the figure, the time axis is plotted on the horizontal axis, and the timing of the start of shutoff of each valve pin, the timing of the start of gas, and the like can be confirmed from the state of filling.

As described above, according to the present invention, in the injection mold having a plurality of cavities, the mold for the injection molding machine is provided with a means for interrupting the supply of the molten resin to each cavity, and a gas in the cavities. Supply means, means for detecting the resin filling in the flow end region for each cavity, and means for controlling the shutoff means and the gas supply means based on the detection. Thus, it is possible to simultaneously mold a variety of molded products, and to allow a variety of shapes and maintain quality.

Further, in the present invention, the injection molding method is an injection molding method for performing injection molding using an injection mold having a plurality of cavities. When the pressure in the flow end region of the cavity reaches a predetermined value, the control means activates the shut-off means of each cavity to stop the supply of the resin, and then the control means operates the shut-off means. Since the gas is supplied to the cavities after the valve is closed, it is possible to preferably perform pressure detection for each cavity under suitable control and simultaneously mold a variety of various molded products in one mold. In addition, a variety of shapes can be allowed, quality can be maintained, and good molded products can be obtained.

(Embodiment 2) FIGS. 10 to 18 show an embodiment 2 of an injection molding die according to the present invention. The injection molding die 1 is substantially the same as that of the first embodiment. Are substantially the same, a gate cut pin is provided in place of the arrangement of the gate and the valve pin, and the same members are denoted by the same reference numerals. For example, four similar members arranged in a cross shape In this case, only two vertical cavities are shown.

As shown in the figure, the injection mold 1 'of the present invention comprises a fixed mold 2' and a movable mold 3 ', and the fixed mold 2' has a fixed mounting plate. The movable mold 3 ′ includes a movable mold plate 6 ′, a spacer block 7 ′, and a fixed mold plate 5 ′.
8 ′, the movable side mounting plate 9 ′, and the ejector plate 1
0 ', the flow path 24' also serving as an ejector pin, 2
5 'and pressure sensors 26' and 27 '. An opening 13a 'into which a nozzle as an injection port for injecting the molten resin is inserted into the fixed mold 2'.
And a sprue member 13 ′ having a sprue 13 b ′ and a cavity for molded articles of various different shapes between the fixed mold 2 ′ and the movable mold 3 ′. 20 'and 21' are provided.

For such cavities 20 ′ and 21 ′, the movable mold plate 6 ′ is provided with gate cut pins 30 and 31 for cutting the gate or pressing the runner portion, and can be moved back and forth. One of the compression bases 32, 33 is formed at one end and connected to be operated by the first control devices 11 ', 12'.

Also, from the cavities 20 ′ and 21 ′,
Pressure sensors 26 ', 27' are provided at the ends of the flow paths 24 ', 25' also serving as ejector pins, and the pressure values detected by the pressure sensors 26 ', 27' are sent to the first controller 11 '. To the compression bases 32, 33 of the gate cut pins 30, 31 for operation. Further, a gas nozzle 2 for introducing gas into the cavities 20 ′ and 21 ′.
2 'and 23' are provided and connected to receive gas supply from a second controller 12 'such as a gas controller. Although a plurality of conditions can be set for the second control device 12 ', the cavities 20' and 2 '
Each 1 'can be connected to a control device which is a separate controller. Also, the second control device 12 '
Is connected to the first control device 11 'and receives a signal for starting gas injection.
Thus, the first control device 11 'is provided so as to be connected to the compression bases 32, 33 of the gate cut pins 30, 31, and the flow paths 24', 25 ', and is connected to the gas nozzles 22', 23 '. A second control device 12 'is provided to be connected. Then, the molten resin injected from the nozzle of the injection molding machine passes through the sprue 13b 'of the sprue member 13' and the hot runner 28 ',
Through 29 ', it is injected into the cavities 20', 21 '.

FIGS. 11 to 15 show examples of four-part family molding according to the present invention. As shown in FIGS. 11 to 15, these four parts have different shapes and different wall thicknesses, but are substantially the same as the four parts in the first embodiment.

That is, the shape 1 is shown in FIG.
As shown in (B), it has a bottomed cylindrical shape,
The plate thickness is 2.5 mm. The shape 2 is shown in FIG.
As shown in (A) and (B), it has a rectangular shape with a bottom and a plate thickness of 2.0 mm. Further, as shown in FIGS. 14A and 14B, the shape 3 has an L-shape and a plate thickness of 1.5 mm. Furthermore, as shown in FIGS. 15A and 15B, the shape 4 has an elongated flat plate shape and a thickness of 1.0 mm.

When these four parts are molded at the same time, there is naturally a difference in the filling time of the resin. The thicker the resin, the lower the flow resistance and tends to flow. Accordingly, the cavities are filled with the resin in the order of shape 1, shape 3, and shape 4 from shape 1 shown in FIG.

In order to briefly explain the structure of the example shown in FIG. 11, the arrangement of each cavity from shape 1 to shape 4 is as shown in the drawing, and each cavity has a side gate structure. Here, 1-A, 2-A, 3-A, 4-A are gate cut pins for pressing the respective gate portions and interrupting the resin supply. The resin pressure is determined by the flow path 1- of each cavity.
The pressure is measured by pressure sensors 1-C, 2-C, 3-C, 4-C installed at positions B, 2-B, 3-B, 4-B. At this position, the pressure value is measured and a signal is sent to start the operation of the gate cut pin or determine the time of the start of gas injection. The gas in each cavity is introduced at positions 1-D, 2-D, 3-D and 4-D, respectively.

FIG. 16 shows a pressure history measured by the pressure sensor 1-C having the shape 1. At the point a in FIG. 16, the pressure sensor 1-C starts to rise. At this time, FIG.
If the resin flow continues to flow into the cavity of the shape 1 while the gate cut pin 1-A of FIG. 1 is retracted, an impact pressure as shown by a broken line b in FIG. The quality is adversely affected, such as deformation due to residual stress.

When the pressure has increased to the point c in FIG.
The gate is cut by advancing the gate cut pin 1-A (FIG. 11). At this time, the pressure is detected, the gate cut pin 1-A is activated, and a time lag occurs until the gate is closed. In this embodiment, a time lag of 0.2 seconds occurs.

Attention must be paid to the fact that impact pressure builds up during this time, which may affect the quality. In this case, it is necessary to set the pressure sensor not at the end of the resin flow path but at a position slightly upstream from the end to try to avoid impact pressure.

In addition, due to the gate shape and the runner shape pressed by the gate cut pin, particularly when the amount of the resin to be pressed increases, the pressed resin flows into the cavity, and excessive pressure is applied to the cavity. There are also concerns about problems such as the occurrence of burrs and burrs. Therefore,
Care must be taken with the position of the pressure sensor and the pressure value at point c. In the case of the present embodiment, the arrangement of the pressure sensors is as shown in FIG.

In this molding, when molding is performed without actually shutting off the gate for each cavity, the pressure applied to the cavity of shape 1 reaches 400 kgf / cm ² or more. , About 210kgf / c
The internal pressure of the cavity is kept at m ² , and an excessive increase in the cavity pressure can be avoided.

FIG. 17 shows the pressure values measured by the pressure sensors 1-C to 4-C set in the shapes 1 to 4 when filling the resin.

In this embodiment, the shapes 1 and 2 are filled at substantially the same time, and after the respective gates are shut off, the shapes 3 and 4 are filled at the same pressure for substantially the same time.

The feedback values of the pressures 1-B to 4-B of the shapes 1 to 4 are 25, 25, 60, 8
It is 0 kgf / cm ² . The internal pressure of the cavity at the time of filling is 210, 250, 380, 410 kgf / cm ² .

The gas injection is started from the point c in FIG. 16 by operating the delay timer.

FIG. 18 shows the process from resin filling to gas holding pressure and cooling in the main molding for each cavity. In the drawing, the time axis is plotted on the horizontal axis, and the timing of the start of advance of each gate cut pin, the timing of the start of gas, and the like can be confirmed from the filling state.

As described above, according to the present invention, it is possible to simultaneously form a variety of various molded products with one mold, and it is possible to allow a variety of shapes and maintain quality.

[0085]

According to the present invention, in a mold for an injection molding machine according to the present invention, in a mold for injection molding having a plurality of cavities, supply of molten resin to each of the cavities is shut off. Means, means for supplying gas to the cavities, means for detecting resin filling in the flow end region for each of the cavities, and means for controlling the shutoff means and the gas supply means based on the detection. Therefore, it is possible to simultaneously mold a variety of various molded products with one mold, and it is possible to allow a variety of shapes and maintain quality.

In the injection molding die according to the second aspect of the present invention, since the shut-off means is a gate valve pin mechanism,
Filling of the supplied resin can be suitably blocked, and a good molded product can be obtained.

In the injection molding die according to the third aspect of the present invention, since the blocking means is a gate cut pin mechanism,
Resin filling can be satisfactorily blocked, and a suitable molded product can be obtained.

In the injection molding die according to the fourth aspect of the present invention, since the detecting means is a pressure sensor provided in a flow end region of each of the cavities, it is possible to preferably perform pressure detection, and Various kinds of molded articles can be obtained under appropriate control.

In the injection molding die according to the fifth aspect of the present invention, the control means feeds back the value detected by the detection means to control and operate the shutoff means and the gas supply means. Under control, it is possible to simultaneously mold a variety of various molded products with one mold, and obtain a good molded product.

In the injection molding die according to the sixth aspect of the present invention, the pressure value of the pressure sensor is in the range of 20 kgf / cm ² or more. It can be carried out.

According to a seventh aspect of the present invention, in the injection molding method for performing injection molding using an injection mold having a plurality of cavities, the resin filling is performed for each of the cavities in the flow end region. When the pressure in the flow end region of the cavity reaches a predetermined value, the shutoff means of each cavity is operated by the control means to stop the supply of the resin, and then the control is performed. Gas is supplied to the cavity after the closing of the shut-off means by the operation of the means,
Under suitable control, it is possible to simultaneously mold a variety of various molded products with one mold, and to allow a variety of shapes, maintain quality, and obtain good molded products.

According to the injection molding method of the present invention, since the shut-off means is a gate valve pin mechanism,
Filling of the supplied resin can be suitably blocked, and a good molded product can be obtained.

In the injection molding method according to the ninth aspect of the present invention, since the blocking means is a gate cut pin mechanism,
By reliably shutting off, it is possible to suitably maintain the shape and quality of the molded product.

In the injection molding method according to the tenth aspect of the present invention, since the detecting means is a pressure sensor provided in the flow end region of each of the cavities, the pressure can be suitably detected, and good results can be obtained. A molded article can be obtained.

In the injection molding method according to the eleventh aspect of the present invention, the control means feeds back the value detected by the detection means to control and operate the shutoff means and the gas supply means. Underneath, it is possible to simultaneously mold a variety of various molded products with one mold, and to allow a variety of shapes and maintain quality.

In the injection molding method according to the twelfth aspect of the present invention, since the pressure value of the pressure sensor is in the range of 20 kgf / cm ² or more, it is possible to suitably detect the filling pressure and perform good injection molding. Can be.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view illustrating an injection mold according to a first embodiment of the present invention.

FIG. 2 is a schematic view of a molded product having various shapes by multi-cavity according to the present invention.

FIG. 3 is a view showing a molded product having a cylindrical shape with a bottom in FIG. 2;
(A) is a longitudinal sectional view, and (B) is a bottom view.

FIG. 4 is a view showing a bottomed rectangular molded product of FIG. 2;
(A) is a longitudinal sectional view, and (B) is a bottom view.

5A and 5B are views showing the L-shaped molded product of FIG. 2, wherein FIG. 5A is a longitudinal sectional view and FIG. 5B is a bottom view.

6A and 6B are views showing the flat molded product of FIG. 2, wherein FIG. 6A is a longitudinal sectional view and FIG. 6B is a bottom view.

FIG. 7 is a diagram illustrating a pressure history measured by a pressure sensor having a shape 1 according to the first embodiment of the present invention.

FIG. 8 is a diagram showing pressure values measured at the time of resin filling by pressure sensors set in each shape according to the first embodiment of the present invention.

FIG. 9 is a diagram showing a process of gas injection from resin filling at each pressure set to shapes 1 to 4 in Example 1 of the present invention.

FIG. 10 is a schematic sectional view showing an injection mold according to a second embodiment of the present invention.

FIG. 11 is a schematic view of a molded product having various shapes by multi-cavity according to the second embodiment of the present invention.

FIG. 12 is a view showing a molded product having a cylindrical shape with a bottom in FIG. 11;
(A) is a longitudinal sectional view, and (B) is a bottom view.

FIG. 13 is a view showing a bottomed rectangular molded product of FIG. 11;
(A) is a longitudinal sectional view, and (B) is a bottom view.

FIG. 14 is a view showing the L-shaped molded product of FIG. 11;
Is a longitudinal sectional view, and (B) is a bottom view.

FIG. 15 is a view showing the flat molded product of FIG. 11 (A).
Is a longitudinal sectional view, and (B) is a bottom view.

FIG. 16 is a diagram illustrating a pressure history measured by a pressure sensor having a shape 1 according to the second embodiment of the present invention.

FIG. 17 is a diagram showing a pressure value measured at the time of resin filling by a pressure sensor set in each shape according to the second embodiment of the present invention.

FIG. 18 is a diagram showing a process of gas injection from resin filling at each pressure set to shapes 1 to 4 in Example 2 of the present invention.

[Explanation of symbols]

 1, 1 'Injection molding die 2, 2' Fixed die 3, 3 'Movable die 4 Fixed mounting plate 5, 5' Fixed die plate 6, 6 'Movable die plate 7, 7' Pressure receiving plate 8, 8 'Spacer block 9, 9' Movable mounting plate 10, 10 'Ejector plate 11, 11' First control device 12, 12 'Second control device 13, 13' Sprue member 13a, 13a 'Opening Part 13b, 13b 'Sprue 14 Gate 15 Gate 16 Valve pin 17 Valve pin 18 Cylinder 19 Cylinder 20, 20' Cavity 21, 21 'Cavity 22, 22' Gas nozzle 23, 23 'Gas nozzle 24, 24' Flow path 25, 25 'Flow path 26, 26 'Pressure sensor 27, 27' Pressure sensor 28, 28 'Hot runner 29, 29' Hot runner 30 Gate cup Pin 31 gate - and cut pin 32 compression base 33 compression base

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4F202 AG07 AP03 CA11 CB01 CK03 CK06 CK07 CK89 CL01 4F206 AG07 AP03 JA05 JL02 JM04 JN15 JN17 JN27 JP12 JP30 JQ81

Claims (12)

[Claims] 1. An injection mold having a plurality of cavities, a means for interrupting supply of molten resin to each of the cavities, a means for supplying gas to the cavities, and a step of filling a resin for each of the cavities. And a means for controlling the shut-off means and the gas supply means on the basis of the detection. 2. The injection molding die according to claim 1, wherein said blocking means is a gate valve pin mechanism. 3. The injection mold according to claim 1, wherein said blocking means is a gate cut pin mechanism. 4. The injection mold according to claim 1, wherein said detecting means is a pressure sensor provided in a flow end region of each of said cavities. 5. The injection mold according to claim 1, wherein said control means feeds back a value detected by said detection means to control and operate said shutoff means and gas supply means. 6. A pressure value of the pressure sensor is 20 kgf /
The injection mold according to claim 4, wherein the diameter is in a range of not less than cm ² . 7. An injection molding method for performing injection molding using an injection mold having a plurality of cavities, wherein a resin filling is detected for each of the cavities in a flow end region by a detecting means, and When the pressure in the flow end region reaches a predetermined value, the control means activates the shutoff means of each of the cavities to stop the supply of the resin, and then, after the shutoff means is closed by the operation of the control means, An injection molding method comprising supplying a gas to a cavity. 8. The injection molding method according to claim 7, wherein said blocking means is a gate valve pin mechanism. 9. The injection molding method according to claim 7, wherein said blocking means is a gate cut pin mechanism. 10. The injection molding method according to claim 7, wherein said detecting means is a pressure sensor provided in a flow end region of each of said cavities. 11. The injection molding method according to claim 7, wherein said control means feeds back a value detected by said detection means to control and operate said shutoff means and gas supply means. 12. A pressure value of the pressure sensor is 20 kgf.
/ Cm ² or more.
3. The injection molding method according to 1.