WO2013014956A1

WO2013014956A1 - Extrusion apparatus and extrusion method

Info

Publication number: WO2013014956A1
Application number: PCT/JP2012/052832
Authority: WO
Inventors: 暁人佐々木
Original assignee: 住友電装株式会社
Priority date: 2011-07-26
Filing date: 2012-02-08
Publication date: 2013-01-31
Also published as: JP2013022928A

Abstract

The purpose of the present invention is to provide a technique for curtailing the time needed to pre-heat an internal space of a cylinder. In order to achieve this purpose, an extrusion apparatus is provided with a cylindrical cylinder, a screw rotatably arranged in an internal space of the cylinder, and an external heater for heating the internal space from the outer periphery. The extrusion apparatus is further provided with a heater device detachably incorporated into the screw. The heater device is provided with, for example, a heater rod that can be connected to and disconnected from a shaft part in a hollow of the screw.

Description

Extrusion apparatus and extrusion method

The present invention relates to an extrusion apparatus and an extrusion method in which a material is melted in a cylinder and is kneaded and extruded by a screw.

As a configuration example of the extrusion device, for example, in Patent Document 1, a material placed in a cylinder is melted while heating the inside of the cylinder by a heater arranged on the outer wall of the cylinder and a heater arranged in the shaft of the screw. A configuration is disclosed in which the material is kneaded and extruded with a screw.

Here, in the extruding operation in which the screw is rotated to extrude and discharge the material, the screw is gradually heated by shear heat. According to the configuration in which the screw is heated by the heater from the inside of the shaft during the extrusion operation as in Patent Document 1, the vicinity of the screw becomes very high due to the shear heat and the heat from the heater. The material of the part may be excessively heated, and the material discharge may become unstable.

On the other hand, a configuration in which a heater is not provided on the screw shaft and only a heater arranged on the outer wall of the cylinder is used to perform the pushing operation has been conventionally employed. Compared with a configuration in which a heater is provided at the shaft portion of the screw as in Patent Document 1, this configuration has an advantage that the temperature of the screw is less likely to be raised during the extrusion operation, and stable discharge is easily ensured.

JP-A-5-309647

Incidentally, in order to ensure stable material discharge in the extrusion apparatus, it is also important to sufficiently preheat the internal space of the cylinder prior to the start of the extrusion operation. This is because if the push-out operation is started in a state where the internal space of the cylinder is not sufficiently warmed, a part of the material put into the cylinder remains undissolved and the discharge amount becomes uneven. . However, if preheating is performed using only the heater disposed on the outer wall of the cylinder, it takes a very long time until the internal space of the cylinder is sufficiently warmed.

The present invention has been made in view of the above problems, and an object thereof is to provide a technique capable of shortening the time required for preheating the internal space of the cylinder.

A first aspect is an extrusion apparatus, which is a cylindrical cylinder, a screw rotatably disposed in the internal space of the cylinder, an external heater that heats the internal space from the outer peripheral side, and a detachable attachment to the screw. And an internal heater that can be incorporated.

A 2nd aspect is an extrusion apparatus which concerns on a 1st aspect, Comprising: The said screw is provided with the hollow axial part, The said internal heater is inserted / extracted in the hollow site | part formed in the axial part of the said screw. As a result, it is detached from the screw.

A third aspect is an extrusion apparatus according to the first or second aspect, wherein an internal heater unit including the internal heater and a control unit that controls the internal heater includes the cylinder, the screw, and the external heater. It is configured so as to be separable from the housing to be disposed on.

A fourth aspect is an extrusion method, in which a) a step of preheating the internal space of the cylindrical cylinder, b) a material is charged into the preheated internal space, and the material is disposed in the internal space. Rotating the screw to extrude the material from the internal space, and the step a) heating the internal space from the outer peripheral side while heating the internal space via the screw. Is provided.

A fifth aspect is an extrusion method according to the fourth aspect, wherein the heating of the internal space through the screw is performed by an internal heater inserted into a hollow portion formed in a shaft portion of the screw. This is done by heating the screw.

The sixth aspect is an extrusion method according to the fifth aspect, wherein the step b) is performed in a state where the internal heater is extracted from the shaft portion of the screw.

According to the first to third aspects, the external heater that heats the internal space of the cylinder from the outer peripheral side and the internal heater that is detachably incorporated in the screw are provided. According to this configuration, since the internal space of the cylinder can be preheated using the external heater and the internal heater, the internal space of the cylinder can be quickly preheated. Further, if the internal heater is removed from the screw, no residual heat is accumulated in the screw, and the heating state of the screw can be stopped quickly.

In particular, according to the second aspect, since the internal heater is detached from the screw by being inserted into and removed from a hollow portion formed in the shaft portion of the screw, the internal heater is pulled out from the shaft portion of the screw. Since the heat of the screw is dissipated from the hollow part, the temperature of the screw is difficult to increase.

In particular, according to the third aspect, the internal heater unit including the internal heater and the control unit that controls the internal heater is configured to be separable from the casing in which the cylinder, the screw, and the external heater are disposed. The unit can be shared among multiple extrusion devices.

According to the fourth to sixth aspects, the step of preheating the internal space of the cylinder includes the step of heating the internal space from the outer peripheral side while heating the internal space via the screw. According to this configuration, since the internal space is warmed from both the screw side and the outer peripheral side, the internal space of the cylinder can be quickly preheated.

Particularly, according to the sixth aspect, in the state where the internal heater is extracted from the hollow portion formed in the shaft portion of the screw, the step of pushing the material from the internal space by rotating the screw is performed. According to this configuration, since the heat of the rotating screw is dissipated from the hollow portion, it is difficult to raise the temperature of the screw. As a result, the material can always be extruded stably.

The objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description and the accompanying drawings.

It is a figure which shows typically the structure of an electric wire coating | coated apparatus. It is a side view which shows the structure of a screw cylinder typically. It is a front view of a screw cylinder. It is a figure which shows the structure of an internal heater unit typically. It is a figure which shows the state in which the heater rod was integrated in the screw. It is a figure for demonstrating the flow of the process performed in an extrusion apparatus.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. The following embodiment is an example embodying the present invention, and does not limit the technical scope of the present invention.

<1. Overall configuration>
The overall configuration of the wire covering device 1 will be described with reference to FIG. FIG. 1 is a diagram schematically showing the configuration of the wire coating apparatus 1.

The wire covering device 1 is a device that manufactures a covered wire. For example, the wire drawing machine 10 that stretches the conductor 91 to reduce the diameter, the annealing machine 20 that anneals (anneals) the conductor 91, and the conductor 91 with an insulating coating. The extrusion device 30 is applied to form a covered electric wire 92, the cooler 40 that cools the covered electric wire 92, and the winder 50 that winds up the covered electric wire 92.

In this wire coating apparatus 1, first, the conductor 91 drawn out from a metal wire housing portion (not shown) that houses the conductor 91 in a wound state is reduced in diameter by the wire drawing machine 10, and further, an annealing machine. 20 is annealed. The annealed conductor 91 is subsequently subjected to an insulation coating by the extrusion device 30 to form a covered electric wire 92. The covered electric wire 92 is cooled by the cooler 40 and then wound around the winder 50.

<2. Configuration of Extruder 30>
The configuration of the extrusion device 30 will be described with reference to FIG.

The extrusion device 30 melts and kneads a hopper 31 for containing a pellet-shaped resin or a pellet-shaped resin composition (hereinafter simply referred to as “pellet-shaped resin”) 9 and a pellet-shaped resin 9 that has been charged via the hopper 31. And a cross head 33 for covering the outside of the conductor 91 with the resin extruded from the screw cylinder 32. These

parts

31, 32, and 33 are arranged at fixed positions in the housing 300. The extrusion device 30 includes a control unit 34 that is disposed in the housing 300 and controls each part of the hopper 31, the screw cylinder 32, and the crosshead 33. Further, the extrusion device 30 includes an internal heater unit 35 (FIGS. 4 and 5) configured to be separable from the casing 300 (specifically, provided so as to be detachable from the screw cylinder 32). Each unit included in the internal heater unit 35 is independently controlled by a control unit (internal heater control unit) 85 (FIGS. 4 and 5) different from the control unit 34.

In the extrusion apparatus 30, when the pellet-shaped resin 9 is charged into the hopper 31, the pellet-shaped resin 9 is melted by the screw cylinder 32, further stirred and kneaded, and extruded to the crosshead 33. In FIG.

<2-1. Screw cylinder 32>
The configuration of the screw cylinder 32 provided in the extrusion device 30 will be described with reference to FIGS. FIG. 2 is a side view schematically showing the configuration of the screw cylinder 32. FIG. 3 is a front view of the screw cylinder 32 as seen from the direction of arrow K in FIG. For easy understanding, the cylinder 71 is shown in a cross-sectional state in FIG.

The screw cylinder 32 includes a cylindrical cylinder 71, an external heater 72, a screw 73, and a drive unit 74. The external heater 72 and the drive unit 74 are electrically connected to the control unit 34 and operate according to instructions from the control unit 34.

The cylinder 71 has a long cylindrical outer shape, and forms an internal space V inside the cylinder. The front end side of the internal space V is connected to the cross head 33 (FIG. 1) while being narrowed.

The external heater 72 is a heating device that heats the internal space V from the outer peripheral side, and is composed of, for example, a resistance heater that generates heat when energized. The external heater 72 is configured by, for example, a cylindrical heater embedded in the peripheral wall of the cylinder 71. However, the aspect of the external heater 72 is not limited to this, and may be configured by a band heater wound around the outer periphery of the cylinder 71, for example.

The temperature of the external heater 72 is controlled by the control unit 34 by a temperature control unit configured by a microcomputer, for example. Specifically, the control unit 34 determines, for example, whether the temperature detected by a temperature sensor (not shown) provided on the inner wall of the cylinder 71 is higher or lower than the target temperature, and the detected temperature is lower than the target temperature. When the temperature is low, the external heater 72 is turned on (energized state), and when the detected temperature is higher than the target temperature, the external heater 72 is turned off (non-energized state).

The screw 73 is a long member made of metal, for example, and is disposed in the internal space V of the cylinder 71. The screw 73 includes a long cylindrical shaft portion 731 extending along the rotation axis T, and a flight 732 spirally disposed on the outer periphery of the shaft portion 731. The shaft portion Q of the shaft portion 731 is hollow, and a heater rod 81 to be described later can be inserted into the hollow shaft portion Q.

The driving unit 74 gives a rotational driving force for rotating the screw 73 about the rotational axis T. The drive unit 74 includes, for example, a motor 741 disposed at a position that does not block the opening of the hollow shaft portion Q of the screw 73, and a mechanism for transmitting the rotational driving force of the motor 741 to the screw 73 (specifically, For example, a belt 742) wound between the rotating shaft portion of the motor and the screw 73 can be used.

<2-2. Internal heater unit 35>
The configuration of the internal heater unit 35 will be described with reference to FIG. FIG. 4 is a diagram schematically showing the configuration of the internal heater unit 35.

The internal heater unit 35 includes a heater rod 81, a grip part 82, a flange part 83, a temperature sensor 84, and an internal heater control part 85.

The heater rod 81 is a heating device that is detachably incorporated in the screw 73, and is constituted by, for example, a resistance heater that generates heat when energized. The heater rod 81 is formed in a long cylindrical shape, and its outer diameter size is slightly smaller than the diameter size of the hollow shaft portion Q of the screw 73. Accordingly, the heater rod 81 can be inserted into and removed from the hollow portion formed in the shaft portion Q of the screw 73, and is attached to and detached from the screw 73 by being inserted into and removed from the hollow shaft portion Q.

The grip portion 82 is connected to an end portion of the heater rod 81 along the longitudinal direction via a connecting portion 820. The grip portion 82 is formed of a highly heat-insulating member so that the operator can safely grip the grip portion 82 even when the heater rod 81 is heated.

The flange 83 is a flange-shaped part that protrudes from the outer periphery of the heater bar 81 and is provided at a position of a length d determined from the free end of the heater bar 81. The length d that defines the disposition position of the flange portion 83 is shorter than the length along the longitudinal direction of the hollow shaft portion Q of the screw 73. In the state where the heater bar 81 is inserted into the shaft part Q of the screw 73, the flange part 83 abuts against the opening end of the screw 73 so that the heater bar 81 is not further inserted deeply into the inner side of the shaft part Q. Regulated by

The temperature sensor 84 is a sensor that detects the temperature of the heater bar 81 and is provided at a predetermined location of the heater bar 81. The temperature sensor 84 is configured to output the detection signal to the internal heater control unit 85.

The internal heater control unit 85 is connected to a power supply line to the heater rod 81 and a conductive line from the temperature sensor 84 (both not shown) via a connector 850 provided at the end of the grip part 82. The internal heater control unit 85 includes an operation panel 851 that receives various instructions from the operator, and receives various inputs from the operator. The internal heater control unit 85 includes, for example, a microcomputer, and controls the temperature of the heater rod 81 in accordance with an instruction input from an operator, detection information from the temperature sensor 84, and the like. More specifically, the internal heater control unit 85 determines whether the temperature of the heater bar 81 detected by the temperature sensor 84 is higher or lower than the target temperature, and if the detected temperature is lower than the target temperature, the heater bar 81 is turned on (energized state), and when the detected temperature is higher than the target temperature, the heater rod 81 is turned off (non-energized state). As a result, the heater bar 81 is always kept substantially in agreement with the target temperature.

<2-3. Assembly of heater rod 81>
A state in which the heater bar 81 is incorporated in the screw 73 will be described with reference to FIG. FIG. 5 is a cross-sectional view schematically showing a state in which the heater rod 81 is incorporated in the screw 73. For easy understanding, the cylinder 71 is shown in a cross-sectional state in FIG.

The operator holds the grip portion 82, inserts the heater rod 81 into the shaft portion Q of the screw 73, and brings the flange portion 83 into contact with the opening end thereof, thereby incorporating the heater rod 81 into the screw 73. Can do. When the heater rod 81 is incorporated in the screw 73 and the internal heater control unit 85 turns on the heater rod 81 (energized state), the screw 73 is heated by receiving heat from the heater rod 81, and the screw 73. The internal space V of the cylinder 71 is warmed through.

Note that the heater rod 81 is configured to be removable from the hollow shaft portion Q as described above. The operator can remove the heater rod 81 from the cylinder 71 by grasping the grip portion 82 and pulling out the heater rod 81 inserted into the shaft portion Q from the shaft portion Q. If the heater bar 81 is removed from the cylinder 71, the internal heater unit 35 can be separated from the casing 300 of the extrusion device 30.

<3. Operation of Extruder 30>
The flow of processing executed in the extrusion apparatus 30 will be described with reference to FIG. FIG. 6 is a diagram for explaining the flow of the processing.

First, the internal space V is preheated. In the preliminary heating of the internal space V, first, the heater rod 81 is in a state of being incorporated in the screw 73 (that is, the heater rod 81 is inserted in the hollow shaft portion Q of the screw 73) (FIG. 5). In this state, the internal heater control unit 85 turns on the heater bar 81 and raises the temperature to a predetermined set temperature (step S11). Then, the screw 73 is warmed up by receiving heat from the heater rod 81. Further, the internal space V of the cylinder 71 is warmed from the center axis side by receiving heat from the screw 73. That is, the internal space V is heated via the screw 73.

When a predetermined time elapses after the heater rod 81 is turned on, the internal heater control unit 85 continues to maintain the heater rod 81 at a predetermined set temperature, while the control unit 34 turns the external heater 72 on. The temperature is raised to a predetermined set temperature (step S12). Then, the internal space V is heated via the screw 73 and also receives heat from the external heater 72 and is heated from the outer peripheral side. As a result, the internal space V is quickly preheated with a uniform temperature distribution.

When the internal space V is heated to a predetermined preheating temperature, the preheating of the internal space V is finished. When the preliminary heating of the internal space V is completed, the internal heater control unit 85 turns off the heater rod 81 (non-energized state). Further, the heater rod 81 is pulled out from the hollow shaft portion Q of the screw 73 (FIG. 2) (step S13). When the heater bar 81 is removed from the screw 73, no residual heat is accumulated in the screw 73, and the heating state of the screw 73 can be stopped quickly. However, during this time, the control unit 34 continues to maintain the external heater 72 at a predetermined set temperature.

Subsequently, an extrusion operation is performed (step S14). In the extrusion operation, while the control unit 34 continues to maintain the external heater 72 at a predetermined set temperature, the pellet-shaped resin 9 is introduced into the preheated internal space V via the hopper 31 and the control unit 34 34 causes the drive unit 74 to start rotating the screw 73 (step S14). The pelletized resin 9 introduced from the hopper 31 is melted in the internal space V, and is pushed out from the tip of the cylinder 71 while being stirred and kneaded by receiving shearing stress from the rotating flight 732 and the inner wall surface of the cylinder 71. The molten resin pushed out from the cylinder 71 is press-fitted into the interior of the cross head 33 and is coated on the outside of the conductor 91 in the cross head 33 (FIG. 1).

As described above, since the internal space V is heated to a predetermined preheating temperature and the screw 73 is also warmed up in advance, when the extrusion operation is started, the pellet-shaped resin 9 is It is quickly and reliably melted and pushed out to the crosshead 33. That is, resin starts to be stably discharged from the crosshead 33 in a very short time (for example, about 15 minutes) after the rotation of the screw 73 is started.

In addition, the screw 73 brings heat by shearing heat as time elapses from the start of rotation. However, in the extrusion operation, since the heater 73 is pulled out of the hollow shaft portion Q in the extrusion operation and is in an air-core state, heat is dissipated from the hollow portion and the temperature rise of the screw 73 is suppressed. The If the temperature of the screw 73 is excessively increased, the resin becomes too hot only in the vicinity of the screw 73 and the resin may not be stably discharged. In the above configuration, the temperature of the screw 73 increases. Such an undesirable temperature distribution is difficult to be formed due to the difficulty. Therefore, even if time elapses, the resin is stably discharged from the crosshead 33.

<4. Effect>
According to the above embodiment, the external heater 72 that heats the internal space V of the cylinder 71 from the outer peripheral side and the internal heater unit 35 that is detachably incorporated in the screw 73 are provided. According to this configuration, since the internal space V can be preheated using the external heater 72 and the heater rod 81 provided in the internal heater unit 35, the internal space V can be preheated quickly. By preheating the internal space V quickly and sufficiently, the length of the screw 73 in the longitudinal direction is relatively short when a material that is not easily melted is used (for example, when a relatively insoluble material such as urethane is used). In the case of using the extrusion device 30 or the like, the material can be reliably melted.

In particular, in the above-described embodiment, the heater bar 81 is detachably attached to the screw 73, and when the preheating is completed, the heater bar 81 is removed from the screw 73. Therefore, when the preliminary heating is completed, the heating state of the screw 73 can be quickly stopped.

Further, in the above embodiment, the heater rod 81 is detached from the screw 73 by being inserted into and removed from the hollow portion formed in the shaft portion Q of the screw 73. Therefore, the heater rod 81 is attached to the shaft portion of the screw 73. If it is taken out from Q, the heat of screw 73 will be dissipated from a hollow part. Therefore, as described above, if the heater rod 81 is removed from the screw 73 while the extrusion operation is being performed, the heat of the rotating screw 73 is dissipated from the hollow portion, so that the temperature of the screw 73 is difficult to increase. As a result, the resin can always be extruded stably.

In the above-described embodiment, the internal heater unit 35 is configured to be separable from the casing 300 in which the cylinder 71, the screw 73, the external heater 72, and the like are disposed. Can be shared between the extrusion apparatuses 30 of the present invention. That is, when preheating using the internal heater unit 35 is completed in the first extrusion device 30 and the internal heater unit 35 is removed and an extrusion operation is started, the internal heater unit 35 is used to perform the second operation. Preheating of the extrusion device 30 can be performed.

For example, when the screw 73 is configured to be detachable from the cylinder 71, the screw 73 can be warmed up in the screw 73 removed from the cylinder 71. For example, when the resin as a material in the extrusion device 30 is changed from the first resin (resin A) to the second resin (resin B), while the extrusion operation of the resin A is performed in the extrusion device 30, At a different location, the heater rod 81 is inserted into the hollow shaft portion Q of the screw 73 different from the screw 73 used for the resin A extrusion operation to turn it on, and the screw 73 is heated. You can start the machine. In this way, when the extrusion operation of the resin A is completed in the extrusion device 30 and the cleaning of the cylinder 71 is completed, the screw 73 that has been warmed up in another place is attached to the cylinder 71 for preheating. Can do. Here, since the screw 73 is warmed up in advance, the time required for preliminary heating is shortened.

<5. Modification>
In the above embodiment, the internal heater unit 35 is configured to be separable from the housing 300, and the control unit 34 and the internal heater control unit 85 are configured separately from each other. The

control units

34 and 85 may be integrally formed. Moreover, it is good also as a structure which further provides the overall control part which controls each

control part

34 and 85 collectively.

In the above embodiment, the screw 73 is uniaxial, but it may be biaxial or triaxial.

In the above embodiment, the extrusion device 30 is used for the production of a covered electric wire, but the extrusion device 30 may be used for other purposes.

Although the present invention has been described in detail, the above description is illustrative in all aspects, and the present invention is not limited thereto. It is understood that countless variations that are not illustrated can be envisaged without departing from the scope of the present invention.

30 Extruder 32 Screw Cylinder 34 Control Unit 35 Internal Heater Unit 71 Cylinder 72 External Heater 73 Screw 74 Drive Unit 81 Heater Bar 82 Grip Portion 83 Head 84 Temperature Sensor 85 Internal Heater Control Unit

Claims

A cylindrical cylinder;
A screw rotatably disposed in the internal space of the cylinder;
An external heater for heating the internal space from the outer peripheral side;
An internal heater detachably incorporated in the screw;
An extrusion apparatus comprising:
The extrusion apparatus according to claim 1,
The screw includes a hollow shaft portion;
The internal heater is removed from the screw by being inserted into and removed from a hollow portion formed in the shaft portion of the screw.
Extrusion equipment.
The extrusion apparatus according to claim 1,
An internal heater unit including the internal heater and a control unit that controls the internal heater is configured to be separable from a casing in which the cylinder, the screw, and the external heater are disposed.
Extrusion equipment.
a) preheating the internal space of the cylindrical cylinder;
b) charging the material into the preheated internal space and rotating the screw disposed in the internal space to push the material out of the internal space;
With
Step a)
Heating the internal space from the outer peripheral side while heating the internal space via the screw;
An extrusion method comprising:
The extrusion method according to claim 4, wherein
The extrusion method, wherein the heating of the internal space through the screw is performed by heating the screw with an internal heater inserted into a hollow portion formed in a shaft portion of the screw.
The extrusion method according to claim 5,
An extrusion method in which the step b) is performed in a state where the internal heater is extracted from the shaft portion of the screw.