JPH0149092B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to molding materials, in particular to a combination of extrusion equipment, injection equipment and injection mold equipment.

Generally, plastic molding is carried out by utilizing the thermoplasticity of the synthetic resin that is the main raw material. There are various processing methods depending on the properties of the resin and auxiliary materials, etc.
Most of the molding methods utilize the heat-resistant properties of synthetic resins, that is, thermoplasticity or thermosetting.

Such molding methods include compression molding, transfer molding, injection molding, extrusion molding, blow molding, calendering, and the like.

Among these, thermoplastic molding material is supplied into the cylinder from a supply device, sent to the heating section by a screw provided so as to be rotatable and slidable in the axial direction, and heated and pressurized in the heating section. A molding device that injects the plasticized molding material into the cavity of a mold from a nozzle provided at the tip of the cylinder is well known, and is widely used for molding thermoplastic materials. It is also used in thermosetting molding materials.

In a screw-type injection molding machine like the one mentioned above,
The rotation of the screw applies pressure to the plastic pellets that are the molding material, and in addition to the heat conduction from the cylinder, the pellets are heated and pressurized by the shear heat generated as the screw rotates, and the molding material is melted. The plastic is injected at high pressure into the cavity of the mold from a nozzle installed at the tip of the cylinder to form the plastic. Since there is insufficient automation to control the mutual relationships, there has been a problem in that when trying to mold a large, complex-shaped product, it is not always possible to obtain the best product.

Also, Publication No. 58-48114, Japanese Patent Application Publication No. 55-77542
The above publications disclose a combination of a screw-type extrusion device and a piston-type injection cylinder device, but since a check valve is not provided between the two devices, (1) the injection cylinder If the pressure is increased, the molding material will flow back into the screw type extrusion device, making accurate measurement impossible.(2)
In addition, as a result, sufficient injection pressure cannot be obtained, and the purpose of providing an injection cylinder is lost.(3) There is a risk that the molding material resin, which is reciprocated between the injection cylinder device and the screw-type extrusion device, may deteriorate. 4) This device has problems such as the inability to control the injection speed.

Generally, in order to obtain a molded product of large size and complex shape, it is necessary to press a predetermined amount of resin into a mold at a predetermined high pressure and at a speed controlled by a predetermined program.

The present invention has been made based on the above-mentioned viewpoints, and its object is to accurately introduce a molding material resin into the cavity of a mold in a predetermined amount at a predetermined high pressure and according to a predetermined program. It is an object of the present invention to provide an automated molding device that is capable of press-fitting at a controlled speed and that can optimally control the operations of the drive and heating devices of these devices in relation to each other.

The gist of this is that a thermoplastic molding material is supplied into the cylinder from a supply device, and then sent to the heating section of the cylinder by a rotatably supported screw, where it is heated and pressurized. A screw-type extrusion device that uniformizes the flow of the molding material that has become plastic with a breaker plate provided at the tip of the cylinder and then extrudes it from the nozzle; An injection cylinder device that receives molding material into a cylinder tube and injects a precisely controlled predetermined amount of molding material from a nozzle provided in the cylinder head, and a molding material between the screw type extrusion device and the injection cylinder device. It consists of a check valve installed in the transport path, a lower mold and an upper mold having a heating section and a cooling section, and a device for bringing these upper and lower molds into contact with each other. An injection mold device that performs molding in a cavity formed between the upper and lower molds, and a control that controls the operations of the screw type extrusion device, the injection cylinder device, and the injection mold device according to a predetermined program. The object of the present invention is to constitute a molding device by operating these devices at the most preferable timing, heating and cooling them, thereby making it possible to mold a large, complex-shaped molded product in the best possible condition.

Hereinafter, the details of the present invention will be specifically explained with reference to the drawings.

FIG. 1 is an explanatory diagram showing one embodiment of the molding apparatus according to the present invention, and FIG. 2 is an explanatory diagram of another embodiment of the injection cylinder device portion.

In the figure, reference numeral 1 denotes a molding device comprising a screw type extrusion device 2, an injection cylinder device 3, an injection mold device 4, and a control device 5 including a numerical control device for controlling these devices.

The screw type extrusion device 2 includes a cylinder 6, a screw 7, a breaker plate 8, a wire mesh 9, heating coils 10, 10, a nozzle 11, a check valve 12, a supply device 13, a compactor 14,
It consists of a motor 15, an encoder 16, a motor 17, an encoder 18, and an inverter 19.

In this embodiment, the injection cylinder device 3 is configured to be able to accurately inject a predetermined amount by receiving a predetermined unit injection amount of molding material for each injection. Cylinder tubes 20, 21, cylinder heads 22, 23, 24,
It consists of pistons 25, 26, piston rods 27, automatic valves 28, 29, nozzles 30, heating coils 31, and inverters 32, and includes a cylinder tube 20, a head 22, and a piston 25 for receiving, filling, and injecting molding material. The internal volume space thus formed is manufactured to a precise predetermined amount.

Thus, the injection mold device 4 is mounted on the table 3.
3, guide shafts 34, 34, fixed plate 35, nut 3
6, 36, mounting plate 37, heat insulation plate 38, receiving plate 39,
Spacer block 40, bush 41, mold valve 42, lower mold 43, heating coils 44, 44, upper mold 45, heating coils 46, 46, guide receiving plate 4
7, 47, upper die mounting plate 48, feed screw 49, motor 50, motor bracket 51, slider 52,
It consists of a slider receiving plate 53, a slider guide plate 54, an encoder 55, and an inverter 56.

First, the screw type extrusion device 2 of the molding device 1 will be explained.

The motor 17 has its drive shaft connected to the rear end of the screw 7, and is provided with an encoder 18 that rotates the screw 7 and detects changes in rotation amount and motor torque.

The screw 7 is rotatably provided in the cylinder 6, and is rotated by the drive of a motor 17, and at the same time as the plastic pellets, which are the molding material supplied from the replenisher 13, are sent to the heating section. The molding material is heated by the shear heat, and the molding material is heated and pressurized in the heating section to become plastic, and the molding material is then passed from a nozzle 11 provided at the tip of the cylinder 6 via a check valve 12 to the injection cylinder device 3 for quantitative injection. It is extruded into the cylinder tube 20 of.

A breaker plate 8 having a large number of holes and a wire mesh 9 held by the breaker plate 8 are provided between the tip of the screw 7 and the nozzle 11, thereby making the flow of the molding material uniform and kneading the molding material well. This ensures uniform heating.

The replenisher 13 is attached to the upper part of the cylinder 6, and compresses and supplies plastic pellets, which are molding materials, into the cylinder 6 in a sealed state using a compactor 14 and a motor 15. An encoder 16 is provided to detect the rotation amount of the replenisher 13. It is being

A plurality of heating coils 10, 10 are provided in the cylinder 6 surrounding the screw 7, and the inverter 19
Electric power is supplied from a power supply device (not shown) through the cylinder 6 to heat the cylinder 6.

The portion of the cylinder 6 where the heating coils 10, 10 are provided constitutes a heating section, and the molding material is heated in this heating section by heat conduction from the inner peripheral surface of the cylinder 6.

The nozzle 11 is equipped with a check valve 12 and is attached to the tip of the cylinder 6.

Thus, the molding material is transferred from the supply device 13 to the cylinder 6.
When the molding material is supplied to the inside, the screw 7 is rotated by the drive of the motor 17, and the molding material is sent to the heating section of the cylinder 6, where it is heated and pressurized to become fluidized, and then attached to the tip of the cylinder 6. The liquid is injected from the nozzle 11 through the check valve 12 into the cylinder tube 20 for metered injection.

The check valve 12 is, for example, a check valve such as a ball check, and allows the molding material to pass from the cylinder 6 to the cylinder tube 20 for quantitative injection, but prevents the molding material from flowing in the opposite direction.
This serves to keep the amount of molding material extruded from the cylinder tube 20 into the cavity of the mold device 4, which will be described later, always constant.

That is, when the piston 25 moves to the right in the figure to push out the molding material into the cavity of the mold device 4, the check valve 12 is provided so that the molding material is pushed out at a considerably high pressure and at a desired speed. Furthermore, the pressure and speed can be freely controlled, and the molding material does not flow back into the cylinder 6 of the screw-type extrusion device 2, so the molding material injected into the cavity of the mold device 4 is The measurement accuracy is greatly improved compared to the case where the check valve 12 is not provided.

Then, the injection cylinder device 3 of the molding device 1
I will explain about it.

The injection cylinder device 3 includes a cylinder tube 2
Pistons 25 and 26 are slidably inserted into the interiors of 0 and 21, respectively.
are installed in series through cylinder heads 22, 23, and 24, respectively, into the openings at both ends of the cylinder tubes 20 and 21, and are slidably inserted into the holes provided in the cylinder head 22, with one end attached to the piston 25 and the other end. An automatic valve 2 is provided with a piston rod 27 attached to the piston 26, and is provided at both ends of the outer periphery of the cylinder tube 21 to operate the piston 26.
8 and 29 respectively, a nozzle 30 is attached to the cylinder head 22, and the cylinder tube 20 is heated by receiving electric power from an unillustrated power supply device from an inverter 32 on the outer periphery of the cylinder tube 20.
Heating coil 3 for keeping the molding material in a molten state
1.

In the operation of the injection cylinder device 3, at the beginning of each cycle, the pistons 25 and 26 are at the right end of movement within the cylinder tubes 20 and 21, respectively, and the molten molding material is transferred from the nozzle 11 to the cylinder tube 2.
In synchronization with the injection into the piston 26, hydraulic pressure is supplied from a hydraulic unit (not shown) into the cylinder tube 21 by the operation of automatic valves 28 and 29.
The molding material is injected until the molding material moves precisely to the end of its movement to the left in the drawing together with the piston 25 via the piston rod 27, so that the amount of the molding material is always exactly a predetermined constant amount.

Next, the piston 25 is supplied with hydraulic pressure from a hydraulic unit (not shown) through the operation of the automatic valves 28 and 29, and moves together with the piston 26 via the piston rod 27 to the end of its movement in the direction of the cylinder head 22.
A predetermined amount of molding material is precisely injected from a nozzle 30 into the cavity of an injection mold device 4, which will be described next, and molded under a maintained pressure. The internal volume space serves as a precise scale or meter for injecting the molding material into the next mold device 4.

Next, the injection mold device 4 of the molding device 1 will be explained.

The lower mold 43 has heating coils 44, 44 inside, and a mounting plate 37 and a heat insulating plate 3 on the table 33.
8, is fixed via a receiving plate 39, a spacer block 40 and a bush 41.

Further, a sprue and a runner through which the molten molding material passes from the nozzle 30 are provided so as to communicate into the cavity of the lower mold 43 via a mold valve 42 provided in the receiving plate 39 and the bush 41.

The upper mold 45 includes guide shafts 34, 34, and fixed platen 3.
5. It is supported so that it can be raised and lowered via an upper mold mounting plate 48 and a feed screw 49, and has heating coils 46, 46 inside, and a molded product of a desired shape is formed in the cavity of the lower mold 43. With a protrusion to obtain.

A plurality of heating coils 44, 44 and 46, 46 are provided inside the lower mold 43 and the upper mold 45, and power is supplied from a power supply device (not shown) via the inverter 56 to operate the lower mold 43 and the upper mold 45. After heating and making sure that the molten molding material is evenly distributed throughout each part of the mold cavity, the lower mold 43 and the upper mold 45 are heated.
It is used for cooling and molding.

The heat insulating plate 38 is installed between the receiving plate 39 and the mounting plate 37 so that the heat of the lower mold 43 does not escape to the table 33.

The upper mold 45 has four guide shafts 34, 34 each erected on the table 33 so as to straddle the lower mold 43.
Fixed plate 3 attached to the upper end with nuts 36, 36
5, a feed screw 49 that is screwed into a screw hole provided in the fixed platen 35, and an upper die mounting plate 48 that is rotatably and axially locked to one end of the feed screw 49, and can be freely raised and lowered. is attached to the motor 5.
0 has its rotating shaft attached to a feed screw 49, stands upright on a fixed platen 35, and a motor bracket 51 is attached to a slider guide plate 54 having a slit.
It is slidably attached to the slider 52 and the slider receiving plate 53 via the slider 52 and the slider receiving plate 53.

Further, the upper mold 45 has four guides as the feed screw 49 moves along the screw hole of the fixed platen 35 screwed into the feed screw 49 by rotation of the feed screw 49 driven by the motor 50. It moves up and down between predetermined positions using shafts 34, 34 as a guide, and the lower mold 4
The molds are clamped so as to form a mold cavity in which the desired molded product is obtained at the position where they are overlapped.

The control device 5 including the numerical control device automatically controls the screw type extrusion device 2, the injection cylinder device 3, and the injection mold device 4 of the molding device 1, and its operation is as follows. explain.

First, the control device 5 controls the screw type extrusion device 2.
The molding material is supplied from the replenisher 13 into the cylinder 6 under the control of the compactor 14 drive motor 15 and encoder 16, the screw 7 is rotated under the control of the motor 17 and encoder 18, and the heating coils 10, 10 are rotated. The molding material is heated and melted under control via the inverter 19, and the cylinder 7
The molten molding material is injected from the injection port of the nozzle 11 at the tip of the cylinder tube 20 of the cylinder device 3.
It is weighed out and a predetermined amount is injected.

The control device 5 also controls the automatic valve 28 of the injection cylinder device 3 in synchronization with the injection of the molten molding material into the cylinder tube 20, which has been heated by the control of the heating coil 31 via the inverter 32. , 29 to move the pistons 25, 26 from the right end of movement to a predetermined end of movement position shown in the left figure to inject a predetermined amount of molding material. 25 and 26 to the right from the position shown in the figure, and by controlling the mold valve 42 of the injection mold device 4, the upper mold 45 is moved in advance by the control of the mold clamping motor 50 and the encoder 55, and the lower mold 45 is moved to the right. The mold 43 is clamped, and a predetermined amount is injected by the cylinder tube 20 into the cavities of the lower mold 43 and the upper mold 45, which are heated by the control of the heating coils 44, 44 and 46, 46 via the inverter 56. The measured molten molding material is transferred to nozzle 3.
Inject from 0, stop heating while holding pressure, lower mold 43
The upper mold 45 is cooled naturally or by a cooling device (not shown) for molding.

FIG. 2 shows another embodiment of the present invention regarding the injection cylinder device 3, and the same reference numerals or the same reference numerals with a superscript '' as in FIG. show something

In the figure, cylinder tube 20' and cylinder heads 22' and 23' or even piston 25' are shown.
The volume of the space into which the molding material is injected and filled from the nozzle 11 through the check valve 12 is increased from the nozzle 30 to the injection mold device 4 by the rightward movement of the piston 25'. It is configured to have an appropriate size, for example, n times the amount of injection per injection, or around that, and during the injection molding, the amount and length of the extrusion movement to the right of the piston 25' are controlled by the injection amount. By performing intermittent movement whose position is precisely controlled in accordance with the sequence of , the amount of molding material injected for each injection molding is precisely controlled.

That is, in this embodiment, a slider 57 is provided at the other end of the piston rod 27 and is guided by a guide section parallel to the axis of the rod 27.
7 is connected via a connecting rod 60 to a crank 59 provided on a rotating shaft 58 located on an extension of the shaft of the rod 27.

The rotary shaft 58 is provided with a gear 61 that meshes with a pinion gear 62 provided on an output rotary shaft 64 of a drive motor 63, and drives a crank 59. 65 is the output rotation shaft 64 of the electric motor 63
An encoder provided at the input 6 of the electric motor 63 detects the rotation angle of the electric motor 63, that is, the crank 59, and therefore the position of the piston 25' in the cylinder tube 20 via the slider 57 and the rod 27.
6 is given accurate control signals for activation and deactivation via the control device 5. At the same time, the rotational speed of the electric motor 63 during operation, that is, the moving speed of the piston 25' is also controlled.

Therefore, the nozzle 1 is placed inside the cylinder tube 20'.
Once a predetermined amount of molding material is filled from 1, the electric motor 63 is controlled and driven to drive the piston 25' each time molding is performed in the injection mold molding device 4.
The appropriate amount of molding material required for one injection molding is injected from the nozzle 30, and when the molding material is exhausted after several injections, the process moves to the filling process from the nozzle 11, as shown in FIG. As in the embodiment described above, it is possible to inject a precisely controlled predetermined amount of molding material into the injection molding device 4.

In this embodiment, a case has been described in which a crank rotationally driven by an electric motor is used to drive the movement of the piston 25'. Of course, it is also possible to use a moving feed mechanism that combines screws or nuts that mesh with each other, or gears or the like.

Since the present invention is configured as described above, the present invention detects, determines, and calculates the interrelationships of each drive and heating device, etc., and optimally controls these to form large and complex shapes. It is possible to provide an automated molding device that can obtain the best quality products and that does not require much time and effort.

Note that the configuration of the present invention is not limited to the above-mentioned embodiments; for example, a motor and a feed screw are used as the actuating device for the upper die of an injection mold device;
A hydraulic cylinder or toggle mechanism may be used;
Further, water holes for cooling may be provided inside the lower mold and the upper mold, and a known cartridge heater may be used as the heating coil in the mold.
The configuration of each element can be freely changed in design within the scope of the purpose of the present invention, and the present invention encompasses all of them.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing one embodiment of the molding apparatus according to the present invention, and FIG. 2 is an explanatory diagram of another embodiment of the injection cylinder device portion. DESCRIPTION OF SYMBOLS 1... Molding device, 2... Screw type extrusion device, 3... Injection cylinder device, 4... Injection mold device, 5... Control device, 6... Cylinder, 7
... Screw, 8 ... Breaker plate, 9
... wire mesh, 10 ... heating coil, 11 ... nozzle, 12 ... check valve, 13 ... supply device,
14... Compactor, 15... Motor, 16...
Encoder, 17... Motor, 18... Encoder, 19... Inverter, 20, 21... Cylinder tube, 22, 23, 24... Cylinder head, 25, 26... Piston, 27... Piston rod, 28, 29 ... Automatic valve, 30 ... Nozzle, 31 ... Heating coil, 32 ... Inverter, 33 ... Table, 34 ... Guide shaft, 35
... fixed plate, 36 ... nut, 37 ... mounting plate,
38... Heat insulation plate, 39... Receiving plate, 40... Spacer block, 41... Bush, 42... Mold valve, 43... Lower mold, 44... Heating coil, 45
...Upper die, 46...Heating coil, 47...Guide receiving plate, 48...Upper die mounting plate, 49...Feed screw, 50...Motor, 51...Motor bracket, 52...Slider, 53 ...slider receiving plate,
54...Slider guide plate, 55...Encoder, 56...Inverter, 57...Slider, 5
8... Rotating shaft, 59... Crank, 60... Connecting rod, 61... Gear, 62... Pinion gear, 63
...Electric motor, 64...Output rotating shaft, 65...Encoder, 66...Input.

Claims (1)

[Scope of Claims] 1. A molding device comprising the components described in items (a) to (e) below. (a) Thermoplastic molding material is supplied from the supply device 13 into the cylinder 6, and is sent to the heating section of the cylinder 6 by the screw 7 that is rotatably supported, where it is heated and pressurized to become plastic. A screw-type extrusion device 2 that uniformizes the flow of the molding material by a breaker plate 8 provided at the tip of the cylinder 6 and then extrudes it from a nozzle 11. (b) The plasticized molding material is received from the nozzle 11 of the screw type extrusion device 2 into the cylinder tubes 20, 21, and is precisely controlled through the nozzles 30 provided in the cylinder heads 22, 23, 24. An injection cylinder device 3 that injects a predetermined amount of molding material. (c) A check valve 12 provided in the molding material transport path between the screw type extrusion device 2 and the injection cylinder device 3. (d) Consists of a lower mold 43 and an upper mold 45 each having a heating section and a cooling section, and a device for bringing these upper and lower molds into contact with and separating them, and injects plasticized molding material from the nozzle 11 of the injection cylinder device 3 into the upper and lower molds. Type 45,
An injection mold device 4 for molding within a cavity formed between 43 and 43. (e) A control device 5 that controls the operations of the screw type extrusion device 2, injection cylinder device 3, and injection mold device 4 according to a predetermined program.