JP2000289051A - Unit for feeding additive for lim, injection molding apparatus for lim and method for feeding additive for lim - Google Patents

Abstract

PROBLEM TO BE SOLVED: To highly accurately control amt. of addition of an additive and to use the additive in a wide range of viscosity and shapes. SOLUTION: For feeding an additive into a cylinder, while the additive is extruded from an extrusion cylinder 21 to a fluidized main material, an extrusion outlet is intermittently opened and closed by rotating a disc 27 in which through-holes 28, 28... are made just before the outlet of the extrusion cylinder 21. The amt. of feeding of the additive is controlled by controlling rotating speed of this disc 27.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an injection molding apparatus, and more particularly, to an LI using a liquid resin as a raw material.
The present invention relates to an additive supply unit for an M (liquid injection molding) injection molding device, an LIM injection molding device including the additive supply unit for an LIM injection molding device, and a method for supplying an additive for a LIM.

[0002]

2. Description of the Related Art Conventionally, for molding a molded article such as liquid silicone rubber, raw materials A and B of the molded article are put into a cylinder in which a screw rotates, kneaded at room temperature, and then kneaded. 2. Description of the Related Art An injection molding apparatus that performs injection molding into a heated mold is used.

FIG. 8 is a vertical sectional view showing a schematic configuration of a typical injection molding apparatus.

As shown in FIG. 8, in a conventional injection molding apparatus 100, a cylinder 10 in an injection molding apparatus main body 101 is provided.
2, a kneading screw 103 is provided. Near the root of the cylinder 102, that is, near the right end in FIG.
Is provided, and an LI is provided upstream of the input port 104.
Raw material pump 1 for supplying A component and B component of M material
Reference numerals 06 and 107 are provided, and the tips of the material pumps 106 and 107 for supplying the LIM material and the inlet 104 are connected by hoses 108 and 109.

When an additive and a pigment (colorant) are to be mixed as the third component in addition to the main components A and B in the LIM molding system, an inlet 104 shown in FIG.
In addition, a metering pump 105 that moves in conjunction with the raw material pump 106 or 107 is disposed, and additives or pigments are injected into the screw of the molding machine using a 110 pipe (line). By the way, in the injection molding apparatus for LIM as described above, it is necessary to accurately measure the amounts of additives and pigments to be added to the raw materials A and B in order to keep the quality of the product constant.

However, since the A component and the B component are supplied to the inlet 104 at a high pressure by the raw material pumps 106 and 107, the mixing ratio of the A component and the B component is smaller than that of the A component and the B component like an additive or a pigment. In the case of blending, even if the additive or pigment pump 105 is linked to the raw material pumps 106 and 107, the feed amount of the metering pump 105 is 1/100 to 10/10 of that of the raw material pumps 106 and 107.
Since the pressure was small, about 0, the pressure was not transmitted, and pulsation occurred, resulting in poor mixing such as color unevenness and a difference in color due to a variation in the blending amount.

Further, when the metering pump 105 is operated independently, the interlocking with the feed amount of the raw material pumps 106 and 107 cannot be maintained, and the pressure sufficient to overcome the high pressure transfer of the raw material pumps 106 and 107 is not satisfied. , The feed amount was uneven.

Further, there is a problem in process management that the metering pump 105 and its long line 110 must be washed each time the color of the molded article is changed.

[0009]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems. That is, an object of the present invention is to provide an additive supply unit for LIM, an injection molding apparatus for LIM, and a method for supplying an additive for LIM that can control the amount of additive to be added with high precision.

Another object of the present invention is to provide an additive supply unit for LIM, an injection molding apparatus for LIM, and an additive supply method for LIM that can use a wide range of additives.

Further, the present invention provides an LIM additive supply unit which can easily perform operations such as color change.
It is an object to provide an injection molding apparatus for LIM and an additive supply method for LIM.

[0012]

To achieve the above object, an LIM additive supply unit according to the present invention comprises a discharge cylinder for discharging an additive from a discharge port, and a rotating cylinder which is in contact with the discharge port substantially vertically. A disc provided with a plurality of through-holes for intermittently releasing the discharge port when the disc is rotated, a motor for rotating the disc, and the discharge cylinder. And a control unit that controls the supply amount of the additive by controlling the motor.

The injection molding apparatus for LIM of the present invention comprises an injection molding apparatus main body for injecting an injection material into a mold, a raw material pump for supplying the injection material to the injection molding apparatus main body, and an additive for supplying the injection material to the injection material. An additive supply unit,
A discharge cylinder that discharges an additive from a discharge port, a plurality of disks that are rotatably disposed in contact with the discharge ports substantially perpendicularly, and that release the discharge ports intermittently when the disks are rotated. A disk having a through hole formed therein, and an additive supply unit including a motor for rotating the disk,
A control unit for controlling the injection molding apparatus main body, a motor, and a discharge cylinder.

The above LIM additive supply unit and LI
In the injection molding device for M, the discharge cylinder may be any device as long as it can discharge the additive at a predetermined pressure. For example, a cylinder provided with an opening as a discharge port at the bottom of a cylindrical tube, a piston reciprocating in the cylinder so that the additive contained therein can be discharged, or compressed air or mechanical A device that discharges an additive using pressure may be used.

It is preferable that the discharge cylinder is capable of adjusting the discharge pressure of the additive. Various kinds of additives can be used by adjusting the discharge pressure of the discharge cylinder,
Further, the supply amount of the additive can be controlled by changing the discharge pressure.

The above-mentioned LIM additive supply unit and LIM
In the injection molding apparatus for use, the amount of additive supply can be controlled with high accuracy only by adjusting the rotation speed of the disk.

Further, a discharge cylinder capable of controlling the discharge pressure of the additive is used, and the discharge pressure of the discharge cylinder and the number of revolutions of the disk are controlled to more precisely control the additive supply amount. be able to.

The above-mentioned LIM additive supply unit and LIM
The additive used in the injection molding apparatus for use may be any additive that can be discharged from the discharge cylinder at a predetermined pressure and that can discharge and discharge the additive by rotating the disk. For example, pastes such as pigments and hardeners, liquids, powders, pellets, capsules, tablets and the like can be mentioned. In the above LIM injection molding apparatus, the control unit includes:
It is preferable that the control unit controls the injection molding apparatus main body, the motor, and the discharge cylinder so that the additive is supplied from the additive supply unit when the main material is supplied to the injection molding apparatus main body.

By supplying the additive near the inlet 9 of the LIM molding apparatus main body, it is possible to obtain an effect that it is not necessary to clean a long line when changing the color of a molded product.

In the method for supplying an additive for a LIM according to the present invention, the discharge port is formed by rotating a disk having a plurality of through holes formed in a circle in front of a discharge port of a discharge cylinder for discharging an additive. A method of intermittently supplying the additive by opening and closing, wherein the amount of additive supply is controlled by controlling the rotation speed of the disk.

According to this additive supply method for LIM, the additive supply amount can be controlled with high accuracy only by adjusting the rotation speed of the disk.

Further, in the method for supplying an additive for LIM of the present invention, a disk having a plurality of through-holes formed on a circumference thereof may be formed in a portion immediately before a discharge port of a discharge cylinder for discharging an additive to a main material. A method of intermittently supplying the additive by opening and closing the discharge port by rotating, and discharging the additive when the main material moves downstream of the discharge port in the additive discharge direction. Features.

[0023]

Embodiments according to the present invention will be described below with reference to the drawings.

FIG. 1 is a vertical sectional view showing a schematic configuration of an LIM injection molding apparatus (hereinafter, the LIM injection molding apparatus is simply referred to as “injection molding apparatus”) 1 according to an embodiment of the present invention.

As shown in FIG. 1, this injection molding apparatus 1
In the figure, a hollow cylindrical tubular cylinder 3 is disposed substantially at the center of an injection molding apparatus main body 2, and a jacket 4 for circulating cold water to cool the cylinder 3 is built in around the cylinder 3. . Cold water whose temperature is controlled by a cold water unit 5 is supplied to the jacket 4 via a cold water pipe 6 and circulates in the jacket 4.

A screw 7 for mixing the injection material is built in the cylinder 3, and a root portion of the screw 7, that is, a right end portion in the figure is fixed to a screw driving device 8. The screw driving device 8 has a built-in hydraulic motor and a gear train (not shown), and drives the screw 7 to rotate.

At the base of the cylinder 3, there is provided an injection material inlet 9 for introducing the injection material into the cylinder 3. The injection material supply port 1 is inserted into the injection material supply port 9.
2 is attached, and the line is connected from the raw material pump which sends the A component and the B component of the main material. An additive supply unit 20 according to the present invention is disposed between the raw material pump and the material supply pipe 12. The details of the additive supply unit 20 will be described later.

An injection hydraulic cylinder 15 is disposed on the right side of the screw driving device 8 in the drawing, and moves the screw 7 in the axial direction, that is, in the left and right directions in the drawing. At the time of injection, the screw 7 is pressed to the left in the drawing, and the kneaded injection material stored between the tip of the screw 7 and the tip of the inside of the cylinder 3 is placed in a mold (not shown) disposed on the left side of the cylinder 3. The fuel is injected from the injection port 10 at the tip of the cylinder 3 toward the gate.

Next, the additive supply unit 2 according to the present invention
0 will be described.

FIG. 2 is a vertical cross-sectional view in which the mounting portion of the additive supply unit 20 in the injection material supply pipe 12 is partially enlarged.

As shown in FIG. 2, the injection material supply pipe 12
Is provided with a horizontal opening 13, and an additive supply unit 20 is attached to the right side of the opening 13 in the drawing.

The additive supply unit 20 is composed of a discharge cylinder 21 for discharging the additive, and a disk 27 rotatably disposed in contact with the discharge port 22 of the discharge cylinder 21 substantially vertically. . A piston 23 is provided in the discharge cylinder 21 so as to be movable in the discharge cylinder 21 in the axial direction, that is, left and right in the drawing.
The third rod 23a is driven left and right in the figure by the ejection drive driver 24. Also, the discharge port 22 of the discharge cylinder 21
An additive replenishing pipe 26 is attached to a nearby side surface. The tip of the additive replenishing pipe 26 is connected to an additive container (not shown) and a supply system (not shown) for sending out the additive. Replenish the medicine. A valve 25 is provided in the middle of the additive replenishing pipe 26. The valve 25 is closed except when the additive is replenished in the discharge cylinder 21, and the additive does not move in the additive replenishing pipe 26. It has become.

On the other hand, immediately before the discharge port 22 of the discharge cylinder 21, a disk 27 is disposed so as to contact the discharge port 22 substantially vertically. A rotating shaft 29 is attached to the center of the disk, and can rotate around the rotating shaft 29. The rotating shaft 29 is connected to a rotating shaft of a motor 30.
7 rotates.

FIG. 3 is a perspective view showing a schematic configuration of the additive supply unit 20.

As shown in FIG. 3, the rotating shaft 2
A plurality of through holes 28, 28,... The through holes 28, 28,... Have the same size, and are formed to have substantially the same size as the discharge port 22 of the discharge cylinder 21. The disk 27 is mounted so that the through hole 28 passes through a position facing the front of the discharge port 22.
, Sequentially pass immediately before the discharge port 22, and open and close the discharge port 22 intermittently.

Accordingly, when the discharge drive driver 24 is driven while the motor 30 is rotating at a constant speed to move the piston 23 at a constant speed, the additive tends to be discharged from the discharge port 22 at a constant pressure. Since the discharge port 22 is opened and closed intermittently by the rotation of, the additive is discharged in a state where the additive is divided into blocks each having a predetermined volume.

That is, one through hole 28 is provided in front of the discharge port 22.
The discharge port 22 is opened only for a time t from when the gas begins to pass until the gas passes, so that only the additive discharged from the discharge port 22 during this time t is supplied into the injection material supply pipe 12. Is done.

When the rotational speed of the disk is increased, the time t from when one through hole 28 starts passing through the discharge port 22 to when the through hole 28 finishes passing is shortened.
The number of the through holes 28 passing in front of the nozzle increases, and the time during which the discharge port 22 is released increases. Therefore, when the moving speed of the piston 23 is constant, the time during which the discharge port 22 is released increases as the rotation speed of the disk 27 increases, and the additive supplied from the additive supply unit 20 into the injection material supply pipe 12 is increased. The amount increases. On the other hand, as the rotation speed of the disk 27 decreases, the time during which the discharge port 22 is released decreases, and the amount of additive supplied from the additive supply unit 20 into the injection material supply pipe 12 decreases.

Using this principle, the injection molding apparatus 1 of this embodiment controls the additive supply amount. That is, when increasing the additive amount of the additive, the rotational speed of the disk 27 is increased, and when decreasing the additive amount, the rotational speed of the disk is decreased.

In practice, the relationship between the pressure of the piston 23 in the discharge cylinder 21, the rotation speed of the disk 27, and the supply amount of the additive actually discharged into the injection material supply pipe 12 is obtained from actually measured values. A database is prepared, and the number of revolutions optimal for supplying a desired amount of the additive is determined based on the database, and the disk 27 is rotated at the number of revolutions. For example, a database obtained as a relationship between the above-described parameters is stored in a storage element such as a RAM or a ROM, and an optimum rotation speed for supplying a necessary amount of an additive is determined. A command signal is sent from the control device to the motor 30 so that the disk 27 is rotated by the control of the additive supply unit 20 and thus the additive supply amount.

FIG. 4 is a vertical sectional view of an example of the additive supply unit 20 of the present invention.

The additives having a low viscosity and possibly leaking need to surround the circumference of the disk 27 as shown in FIG.

FIG. 5 is a block wiring diagram of the injection molding apparatus 1 according to this embodiment.

As shown in FIG. 5, the motor 30 of the additive supply unit 20, the discharge driving driver 24, the screw driving device 8, the injection hydraulic cylinder 15, and the electromagnetic valve 31 for opening and closing the communication in the injection material supply pipe 12. , 31 ′ and an electromagnetic valve 25 for opening and closing a supply pipe for the additive to the discharge cylinder 21 are connected to a control unit 50.
Is generally controlled by the

Next, a series of operations of the injection molding apparatus 1 according to this embodiment will be described.

FIG. 6 is a flowchart showing the flow of the operation of the injection molding apparatus 1 of the present embodiment.

When the injection molding apparatus 1 is started by charging the liquid silicone resin components A and B as the main materials into the main component pump, first, an operation screen appears on a monitor (not shown) interlocked with the control unit 50. Enter the amount of additive added. "
Appears. According to this instruction, the required amount of the additive is input from a keyboard (not shown) (step 1).
Then, an arithmetic unit (not shown) in the control unit 50 is operated to calculate the optimum rotation speed and rotation time of the disk 27 to supply this amount of the additive from the input data of the required amount. (Step 2).

When the calculation is completed, the ejection driving driver 24
Starts its operation, presses the piston 23 in the discharge cylinder 21, and presses the additive from the discharge port 22 of the discharge cylinder 21 at a predetermined speed (step 3). At the same time as the start of the operation of the ejection drive driver 24, the motor 30 is rotated at the rotation speed calculated in step 3 (step 4). By the operation of the ejection drive driver 24 and the rotation of the motor 30, the additive is ejected while the ejection port 22 is opened and closed intermittently by the operation of the piston 23 and the disk 27 (step 5). On the other hand, in synchronization with the operation of the ejection drive driver 24 and the disk 27, the electromagnetic valve 3 opens and closes the communication of the injection material supply pipe 12.
1 and 31 'are opened to start feeding the liquid resin as the main material in the hopper 11 (step 6). Here, the operation of the ejection drive driver 24 and the disk 27 and the material supply system 1
The additive is discharged while the main material is flowing through the injection material supply pipe 12 by synchronizing the timing with the input of the main material from Step 1 and discharging the additive toward the flow of the main material ( Step 7).

The screw 7 in the cylinder 3 is also
The rotation of the motor 8 is started in synchronization with the operation of the ejection drive driver 24 and the disk 27, and the kneading of the injection material injected from the injection port 9 is started (step 8). Here, the injection material refers to a material obtained by adding an additive or the like necessary for the main material.

When the injection of the injection material is completed, the screw 7
Is started by the rotation of (step 9). The injection material injected into the heating tower 3 is prevented from generating heat by the rotation of the screw 7 and the cooling by the jacket 4, is mixed, moves from the vicinity of the root of the screw 7 to the distal end, and the inside of the cylinder 3 and the distal end of the screw 7. Is stored in a liquid reservoir (not shown). The screw 7 is retracted as the mixed injection material accumulates (step 10).

When a predetermined amount of the injection material is accumulated in the liquid reservoir and the screw 7 retreats to a certain position, a switch is operated to stop the retraction of the screw 7 (step 1).
1).

Next, the injection hydraulic cylinder 15 is actuated to push the screw 7 to the tip side, and the mixed injection material stored in the liquid reservoir is injected, poured into a mold, and molded (step 12). .

FIG. 7 is a diagram schematically showing a state in which the additive is discharged from the additive supply unit 20 into the injection material supply pipe 12.

As shown in FIGS. 7A to 7C, in the injection molding apparatus 1 of the present embodiment, the additive is discharged while the main material is flowing in the injection material supply pipe 12.

Since the discharged additive is directly charged into the cylinder 3, the composition of the injection material can be controlled with high precision.

As described above, in the injection molding apparatus 1 of the present embodiment, the additive is pushed out from the discharge cylinder 21 to supply the additive, while the through holes 28, 28. Rotates the perforated disk 27 to open and close the discharge port 22 intermittently, and controls the rotational speed of the disk to control the supply amount of the additive.
The supply amount of the additive can be controlled with high accuracy.

The scope of the present invention is not limited to the scope of this embodiment. For example, in the above-described embodiment, the supply speed of the additive is controlled by keeping only the driving speed of the ejection driving driver 24, and thus the pressure of the additive pushed out from the ejection port 22, and controlling only the rotation speed of the disk 27. However, it is also possible to change the drive speed of the ejection drive driver 24 and control the supply amount of the additive by controlling both the drive speed and the rotation speed of the disk 27. By performing such control, it is possible to control the supply amount of the additive with higher precision, and to further expand the range of the additive that can be used.

[0058]

As described in detail above, according to the first, second and sixth aspects of the present invention, the discharge port is formed by rotating a disk having a through hole at the front of the discharge port of the discharge cylinder. Are intermittently opened and closed, so that the additive supply amount can be controlled with high accuracy only by adjusting the rotation speed of the disk.

According to the fourth aspect of the present invention, since the additive supply unit is provided at a connection portion between the raw material pump and the main body of the injection molding apparatus, a line for changing colors of a molded product is provided. Less washing is required.

[Brief description of the drawings]

FIG. 1 is a vertical sectional view showing a schematic configuration of a LIM injection molding apparatus according to an embodiment.

FIG. 2 is a vertical cross-sectional view partially enlarged of an additive supply unit mounting portion in the middle of an injection material supply pipe according to the embodiment.

FIG. 3 is a perspective view showing a schematic configuration of an additive supply unit according to the embodiment.

FIG. 4 is a vertical sectional view showing one example of an additive supply unit of the present invention.

FIG. 5 is a block wiring diagram of the injection molding apparatus according to the embodiment.

FIG. 6 is a flowchart showing a flow of the operation of the injection molding apparatus of the present embodiment.

FIG. 7 is a diagram schematically showing a state in which an additive is discharged from an additive supply unit into an injection material supply pipe of the present embodiment.

FIG. 8 is a vertical sectional view showing a schematic configuration of a conventional typical injection molding apparatus.

[Explanation of symbols]

 3 ... cylinder 4 ... jacket 5 ... cold water unit 6 ... cold water piping 7 ... screw 8 ... screw drive device 9 ... injection material input port 10 ... injection port 11 ... material supply pump system 12 ... Injection material supply pipe 13 Opening 15 Injection hydraulic cylinder 23 Piston 24 Discharge drive driver 25 Electromagnetic valve 26 Additive replenishment pipe 29 Rotary shaft 22 Discharge port 21 ... Discharge cylinder 27 ... Disc 28 ... Through hole 30 ... Motor 31, 31 '... Electromagnetic valve 50 ... Control unit 2 ... Injection molding apparatus body 11 ... Material supply pump system 20 ... Additive supply unit 105 ... Measuring pump 106,107 ... Raw material pump

Claims (5)

[Claims] 1. A discharge cylinder for discharging an additive from a discharge port, and a disk rotatably disposed while being substantially perpendicularly in contact with the discharge port, wherein the discharge port is rotated when the disk is rotated. A disc having a plurality of through holes that intermittently release, a motor that rotates the disc, and a control unit that controls the supply amount of the additive by controlling the discharge cylinder and the motor. An additive supply unit for LIM, comprising: 2. An injection molding apparatus main body for injecting an injection material into a mold, a raw material pump for supplying the injection material to the injection molding apparatus main body, and an additive supply unit for supplying an additive to the injection material. A discharge cylinder that discharges an additive from a discharge port, a disc that is rotatably disposed while being substantially perpendicularly in contact with the discharge port, and that the discharge port is intermittently released when the disc is rotated. A disk with a plurality of through holes perforated, and
An injection molding apparatus for LIM, comprising: an additive supply unit including a motor that rotates the disk; and a control unit that controls the injection molding apparatus main body, the motor, and a discharge cylinder. 3. The injection molding apparatus for LIM according to claim 2, wherein the control unit supplies an additive from the additive supply unit when a main material is supplied to the injection molding apparatus main body. The injection molding apparatus for LIM, wherein the injection molding apparatus main body, motor and discharge cylinder are controlled as described above. 4. The injection molding apparatus for LIM according to claim 2, wherein the additive supply unit is provided at a joint between the raw material pump and the main body of the injection molding apparatus. Characteristic injection molding equipment for LIM. 5. An intermittent addition of the additive by opening and closing the discharge port by rotating a disk having a plurality of through holes formed in a circle in front of a discharge port of a discharge cylinder for discharging the additive. A method for supplying an additive for LIM, comprising controlling an additive supply amount by controlling a rotation speed of the disk.