JPH0530366B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improvement in a synthetic resin molding apparatus, and more particularly to a synthetic resin molding apparatus that combines an extrusion device, an injection device, and an injection mold device.

[Conventional technology]

Generally, plastic molding is carried out by utilizing the thermoplasticity or thermosetting properties 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, but the heat resistance of synthetic resins, that is,
Most of the molding methods utilize thermoplastic or thermosetting properties.

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

Among these, thermoplastic molding material is supplied into the cylinder from a supply device, sent to the heating section by a screw provided rotatably and freely rotatable in the axial direction, and heated and processed in the heating section. A molding method is known in which molding material, which has become plastic after being compressed, is injected into the cavity of a mold from a nozzle provided at the tip of the cylinder. It is also used for molding.

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

In order to solve such problems, the present inventor previously proposed in Japanese Patent Application No. 59-018488 a screw tube in which a thermoplastic molding material was supplied from a supply device into a cylinder, and this was rotatably supported. a screw-type extrusion device that extrudes the molding material, which is sent to the heating section of the cylinder and heated and pressurized to become plastic, from a nozzle provided at the tip of the cylinder; and a nozzle of the screw-type extrusion device. A cylinder device that receives plasticized molding material into a cylinder tube and injects it in a precisely controlled predetermined amount from a nozzle provided in the cylinder head, and a lower mold and an upper mold having a heating section and a cooling section. The mold and
an injection mold device for molding plasticized molding material from the nozzle of the injection cylinder device in a cavity formed between the upper and lower molds; The present invention discloses a molding device comprising a control device for controlling the operations of the screw type extrusion device, the injection cylinder device, and the injection mold device according to a set program.

With the molding device configured as described above, the mutual operations of the screw type extrusion device, injection cylinder device, and injection mold device are appropriately controlled, and the timing of heating and cooling is maintained optimally. Molded products of large size and complicated shapes could be manufactured in good condition.

However, in the above-mentioned molding equipment, the molding material is melted by an external heat source and the shear heat in the screw type extrusion equipment, but uniform and efficient temperature control is not necessarily carried out. The pressure was not completely controlled.

[Problems to be solved by the present invention]

The present invention has been made to solve the above-mentioned problems, and its purpose is to provide a synthetic resin molding apparatus that can accurately control the temperature and pressure of a molding material.

[Means for solving problems]

The gist of the present invention to achieve the above object is to provide a molding apparatus as described above, in which a screw of a screw type extrusion device is supported so as to be movable in its axial direction, and the extrusion nozzle By bringing the end of the side toward and away from the extrusion port leading to the nozzle, the valve is configured to operate as a valve that controls outflow resistance of the resin passing through the extrusion port, and
The axial position of the screw is controlled by the control device.

[Effect]

With the above configuration, by bringing the tip of the screw into contact with the extrusion port of the extrusion nozzle and rotating the screw with the extrusion port closed, the molding material in the cylinder to which the screw is attached is sufficiently filled. It is kneaded and sheared, and is uniformly and efficiently heated and melted by the shear heat and the heating device installed in the cylinder.The temperature is also efficiently controlled by opening and closing the extrusion port by moving the screw. It can be done in Furthermore, the pressure inside the cylinder and the extrusion pressure from the nozzle can be easily controlled by controlling the position of the screw and adjusting the opening amount of the extrusion port, thereby producing a homogeneous and high quality molded product. This makes it possible to manufacture.

〔Example〕

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

FIGS. 1 and 2 are explanatory diagrams showing one embodiment of a synthetic resin molding apparatus according to the present invention.

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 base 6, a cylinder 7, a screw 8, heating coils 9, 9, an extrusion nozzle 10, a check valve 11, and a supply device 1.
2, compactor 13, motor 14, encoder 1
5, a motor 16, an encoder 17, an inverter 18, and a screw moving mechanism 19 for changing the axial position of the screw 8;
1. Consists of a guide rail 192, a feed screw 193, a motor 194, and an encoder 195.

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. 2
0, 21, cylinder heads 22, 23, 24, pistons 25, 26, piston rod 27, automatic valves 28, 29, nozzle 30, heating coil 31 and inverter 32, receives and fills molding material by supply, and injects it. The internal volume space formed by the cylinder tube 20, head 22, and piston 25 is manufactured to have a precisely predetermined amount.

The injection mold device 4 includes a table 33, guide shafts 34, 34, a fixed plate 35, and nuts 36, 3.
6, mounting plate 37, heat insulating 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 plates 47, 4
7. Upper die mounting plate 48, feed screw 49, motor 5
0, a motor bracket 51, a slider 52, a slider receiving plate 53, a slider guide plate 54, an encoder 55, and an inverter 56.

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

The motor 16 has its drive shaft connected to the rear end of the screw 8, rotates the screw 8, and changes in the amount of rotation and motor torque are controlled by the encoder 1.
7.

The screw 8 is rotatably provided in the cylinder 7, and is rotated by the drive of the motor 16, and simultaneously feeds the plastic pellets, which are the molding material supplied from the supply device 12, to the heating section. The molding material is heated by the generated shear heat, and the molding material, which has become plastic through heating and pressure in the heating section, is fed into the injection cylinder device 3 through an extrusion nozzle 10 provided at the tip of the cylinder 7 via a check valve 11. It is extruded into the cylinder tube 20 for injection.

The replenisher 12 is attached to the upper part of the cylinder 7, and compresses and supplies plastic pellets, which are molding materials, into the cylinder 7 in a sealed state using a compactor 13 and a motor 14. An encoder 15 is provided to detect the rotation amount of the replenisher 12. It is being

The heating coils 9, 9 are attached to the cylinder 7 as necessary.
A plurality of cylinders are provided inside the cylinder 7 surrounding the screw 8, and electric power is supplied from a power supply device (not shown) via an inverter 18 to heat the cylinder 7.

The portion of the cylinder 7 where the heating coils 9, 9 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 7.

The extrusion nozzle 10 is equipped with a check valve 11 and is attached to the tip of the cylinder 7.

The screw 8 of the screw type extrusion device 2 of the synthetic resin molding apparatus according to the present invention is movable in the axial direction, that is, in the horizontal direction in the figure with respect to the cylinder 7. It is attached to and is moved by a screw moving mechanism 19.

That is, the motor 16 for rotating the screw 7 is mounted on the moving block 191, and the moving block 191 is moved in the horizontal direction in the figure along the guide rail 192 by rotating the feed screw 193. The screw 8 is adapted to move in its axial direction. The motor 194 is for rotating the feed screw 193, and the encoder 195 is for detecting the amount of rotation thereof.

On the other hand, the tip 8' of the screw 8 is connected to the cylinder 7.
It is constructed as a valve that approaches and separates from the extrusion port 7', and the extrusion port 7' is opened and closed by movement of the screw in the axial direction.

Then, as shown in FIG. 1, with the tip 8' of the screw 8 in contact with the extrusion port 7' of the cylinder and this being closed, the molding material is supplied from the supply device 12 into the cylinder 7, When current is passed through the heating coils 9, 9 and the motor 16 is simultaneously driven to rotate the screw 8, the thermoplastic molding material is sent to the heating section of the cylinder 7, where it is removed from the heating coils 9, 9. The molding material is heated by the heat generated, and is fluidized by the pressure and shear heat of the molding material as the screw 8 rotates. When the fluidized molding material is sufficiently kneaded and uniformly heated, the control device 5 sends a signal to the motor 19.
Sends a command to the drive power supply device (not shown in the figure) of No. 4,
The motor 194 is rotated to move the moving block 191.
is moved to the left in the figure, thereby moving the screw 8 to the left and opening the extrusion port 7' of the cylinder 7 as shown in FIG. In such a case, the fluidized molding material is transferred from the extrusion nozzle 10 attached to the tip of the cylinder 7 to the check valve 1.
1 into a cylinder tube 20 for metered injection. These screw type extrusion devices 2
A series of operations are controlled according to a program preset in the control device 5.

Next, the injection cylinder device 3 will be explained.

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 being supplied with electric power from an unillustrated power supply device from an inverter 32 to 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 accurately to a predetermined position at the end of its movement to the left in the figure together with the piston 25 via the piston rod 27, and the amount of injected molding material is always exactly the predetermined constant amount. ing.

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, and the molding material is discharged from the nozzle 30. The injection molding device 4, which will be described next, is used to precisely inject a predetermined amount into the cavity and mold the product under pressure while maintaining pressure. The internal volume space is
It serves as a precise scale or scale for injecting the injection molding material into the next mold device 4.

Next, the injection mold device 5 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.

Also, the sprue and runner through which the molten molding material passes from the nozzle 30 are connected to the receiving plate 39 and the bushing 41.
It is provided so as to communicate with the inside of the cavity of the lower mold 43 via a mold valve 42 provided therein.

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 also has heating coils 46, 46 inside, so that a molded product of a desired shape can be 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 mold mounting plate 48 that is rotatably and axially engaged with one end of the feed screw 49, and can be freely raised and lowered. The motor 50 has its rotating shaft attached to the feed screw 49, stands upright on the stationary plate 35, and has a motor bracket 51 attached to the 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 die 45 is moved by the 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. The mold is moved up and down between predetermined positions using shafts 34, 34 as guides, and the mold is clamped at a position overlapping the lower mold 43 to form a mold cavity for producing a desired molded product.

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 will be explained below. do.

First, the control device 5 controls the screw type extrusion device 2.
The molding material is supplied from the replenisher 12 into the cylinder 7 under the control of the drive motor 14 and encoder 15 of the compactor 13, the screw 8 is rotated under the control of the motor 16 and encoder 17, and the heating coils 9, 9 The molding material is heated by controlling the temperature via the inverter 18. At this point, the screw 8 has been advanced to the rightmost side in the figure, and the extrusion port 7' of the cylinder is closed by the tip 8' of the screw, so that the molding material inside the cylinder 7 is are sufficiently pressurized, and the heating coils 9,
In addition to the heating by step 9, the molding material is brought into a molten state by the shear heat, and is uniformly and thoroughly kneaded. After a predetermined period of time has elapsed, or when the temperature of the molding material measured by a temperature sensor (not shown in the figure) provided at an appropriate location on the cylinder 7 reaches a predetermined temperature, a signal is sent from the control device 5. The movable block 191 is moved to the left in the figure by activating the motor 194 and rotating the feed screw 193, thereby moving the screw 8 to the left and opening the extrusion port 7' of the cylinder. However, during this time, the molding material is sent forward by the rotation of the screw 8, and when the pressure inside the tip of the cylinder 7 reaches a predetermined pressure, the check valve 11 is opened, and the motor 194 is operated while the screw 8 continues to rotate. and move the screw 8 together with the moving block 191 to the right. In such a case, the molten molding material is injected into the cylinder tube 20 of the injection cylinder device 3 from the injection port of the nozzle 11 at the tip of the cylinder 7.

Further, the control device 5 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, the pistons 25, 26 are moved 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, close the check valve 11, and then close the automatic valve 28. , 29 to move the pistons 25, 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 is moved in advance by controlling the mold clamping motor 50 and encoder 55. 45 is moved, the mold is clamped onto the lower mold 43, and the cylinder is placed in the cavity 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. A predetermined amount of molten molding material is measured by the tube 20 and is injected from the nozzle 30, heating is stopped in a pressure-retaining state, and the lower mold 43 and upper mold 45 are cooled naturally or by a cooling device (not shown). It is something to be molded.

〔Effect of the invention〕

As described above, the synthetic resin molding apparatus according to the present invention is configured to control the axial position of the screw 8 of the screw type extrusion device 2, so that the temperature and pressure of the molding material can be controlled. can be carried out appropriately, thereby making it possible to manufacture homogeneous and high-quality molded products.

Note that the synthetic resin molding apparatus according to the present invention is not limited to the embodiments described above, but includes all modified embodiments that can be easily conceived by a person skilled in the art from the above explanation. .

[Brief explanation of the drawing]

FIGS. 1 and 2 are explanatory diagrams showing one embodiment of a synthetic resin molding apparatus according to the present invention. DESCRIPTION OF SYMBOLS 1... Molding device, 2... Screw type extrusion device, 3... Injection cylinder device, 4... Injection mold device, 5... Control device, 6... Base, 7...
Cylinder, 8...Screw, 9,9...Heating coil, 10...Extrusion nozzle, 11...Check valve, 12...Supplier, 13...Compactor,
14...Motor, 15...Encoder, 16...
Motor, 17... Encoder, 18... Inverter, 19... Screw moving mechanism, 191... Moving block, 192... Guide rail, 193...
...Feed screw, 194...Motor, 195...Encoder, 20, 21...Cylinder tube, 2
2, 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...Insulation board, 3
9...Socket plate, 40...Spacer block, 41...
...Button, 42...Mold valve, 43...Lower mold,
44... Heating coil, 45... Upper mold, 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.

Claims (1)

[Scope of Claims] 1. Thermoplastic molding material is supplied into the cylinder from a supply device, and sent to the heating section of the cylinder by a rotatably supported screw, where it is heated and pressurized to become plastic. A screw-type extrusion device that extrudes the molded material from a nozzle provided at the tip of the cylinder; and a screw-type extrusion device that receives the plasticized molding material from the nozzle of the screw-type extrusion device into a cylinder tube, which is provided in the cylinder head. The above-mentioned injection cylinder device consists of an injection cylinder device that injects a predetermined amount in a precisely controlled amount from a nozzle, a lower mold and an upper mold having a heating part and a cooling part, and a device for bringing these upper and lower molds into contact with each other. an injection mold device that molds the plasticized molding material from the nozzle in a cavity formed between the upper and lower molds, and the screw type extrusion device, the injection cylinder device, and the A control device for controlling the operation of a mold device for molding, and a synthetic resin molding device comprising: a screw of the screw type extrusion device is supported so as to be movable forward and backward in its axial direction; The synthetic resin molding apparatus described above is configured as a valve that opens and closes the extrusion port by moving toward and away from the extrusion port leading to the nozzle, and the axial position of the screw is controlled by the control device.