JP2012014911A - Method for manufacturing electric wire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing electric wire capable of efficiently manufacturing high quality electric wire.SOLUTION: The method for manufacturing the electric wire includes: a material supply stop process (step S02) for detecting that amount of resin required for coating a wire rod with a remaining length to reach a set length is supplied to an extruder to stop the supply of the resin to the extruder; a linear velocity switching process (step S03) for shifting an operation to a lower limit linear velocity coating operation for coating the wire rod with the resin by setting the linear velocity of the wire rod to a low linear velocity which is slower than a regular linear velocity and equal to or faster than a lower limit linear velocity, after stopping the supply of the resin to the extruder; an outer diameter control response changing process (step S04) for quickening a response speed of outer diameter control of the wire rod according to the extruded flow of the resin from the extruder, after stopping the supply of the resin to the extruder; and an outer diameter control stopping process (step S07) for stopping the outer diameter control at a point when the electric wire is extruded by the set length.

Description

  The present invention relates to a method of manufacturing an electric wire in which a wire such as a conductive wire is covered with a resin.

  As a method of manufacturing an electric wire in which a wire is covered with a resin, the amount of coating material required for coating per unit length of the wire is calculated, and the required amount of coating material required for covering the remaining length of the wire is calculated from the calculation result. It is known that a supply stop signal for a covering material is output when the amount of the required covering material for covering the remaining length matches the amount of the covering material supplied to the hopper (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 60-10511

After stopping the resin supply, the resin in the cylinder is pushed out and decreases. Then, the extrusion pressure of the resin is lowered, and the outer diameter of the manufactured electric wire is reduced, resulting in a defective product.
Further, even after the production of the set-length electric wire, the wire is covered with the resin until the apparatus is completely stopped, and the material is wasted.

  The objective of this invention is providing the manufacturing method of the electric wire which can manufacture an efficient and high quality electric wire.

The method of manufacturing an electric wire according to the present invention that can solve the above-described problem is an outer diameter control that controls the wire speed of the wire so that the outer diameter of the electric wire covered with resin is the target outer diameter. A method of manufacturing an electric wire manufactured while performing
A material supply stop process for detecting that the amount of resin required for coating the wire of the remaining length until the set length is supplied to the extruder and stopping the supply of the resin to the extruder;
After stopping the supply of the resin to the extruder, the wire speed switching process for shifting to the lower limit linear speed coating operation in which the wire is coated with the resin at a low linear speed lower than the normal linear speed and higher than the lower limit linear speed. When,
After stopping the supply of resin to the extruder, an outer diameter control response changing process for increasing the response speed of the outer diameter control of the electric wire according to the extrusion flow rate of the resin from the extruder,
Outer diameter control stop processing for stopping the outer diameter control when the electric wire is pushed out for a set length;
It is characterized by including.

  The electric wire manufacturing method of the present invention includes a bobbin exchange process in which the electric wire left on the pass line after the outer diameter control stop process is wound around a take-up bobbin to stop the travel of the wire and to replace the take-up bobbin. There is something.

In the method of manufacturing an electric wire according to the present invention, the running of the wire is stopped together with the outer diameter control stop process, and then a new resin for covering the electric wire is supplied to the extruder to run the wire. A line type switching process for switching to manufacture of an electric wire coated with the supplied resin;
A bobbin exchange process for replacing the take-up bobbin when the electric wire left on the pass line is taken up by the take-up bobbin;
There are things that include.

According to the method for producing an electric wire of the present invention, the electric wire produced from the resin remaining in the extruder can be made a non-defective product having a stable outer diameter.
Thereby, it is possible to manufacture a high-quality electric wire without manufacturing a defective electric wire with an unstable outer diameter while reducing the amount of resin supplied to the extruder to a necessary amount without waste.
In addition, after the resin supply to the extruder is stopped, the wire speed of the wire is set to the lower limit linear speed lower than the steady line speed in advance, so that the time until the apparatus is stopped after the completion of the production of the electric wire can be shortened. As a result, it is possible to reduce the loss of resin extruded between the completion of the production of the electric wire and the stop of the apparatus.

It is a schematic block diagram of the electric wire manufacturing apparatus which can apply the manufacturing method of the electric wire which concerns on this invention. It is a flowchart explaining the stop control in the manufacturing method of the electric wire which concerns on this invention. It is a figure explaining the motion of the extruder in stop control, Comprising: (a)-(e) is a schematic side view of an extruder, respectively. It is a flowchart explaining another stop control in the manufacturing method of the electric wire which concerns on this invention. It is a graph which shows the change of the extrusion flow rate of resin in the extruder in stop control.

Hereinafter, an embodiment of a manufacturing method of an electric wire concerning the present invention is described with reference to drawings.
As shown in FIG. 1, a manufacturing apparatus 11 that manufactures an electric wire by the electric wire manufacturing method of the present embodiment has a feeding bobbin 12 around which the wire 1 is wound, and the wire 1 is fed out from the feeding bobbin 12. It is.

  The wire 1 varies depending on the type of electric wire to be manufactured. For example, when manufacturing an insulated wire, the wire 1 is a conductor, and when manufacturing a coaxial cable, the wire 1 is a shield core wire in which an insulator and an outer conductor are sequentially provided around a central conductor. In the case where the insulated wire whose conductor is covered with resin is covered with a jacket layer made of resin, the wire 1 is an insulated wire.

  A guide roller 13 is provided on the downstream side of the feeding bobbin 12, and the wire 1 fed from the feeding bobbin 12 is hung on the guide roller 13 and guided to the extruder 14 on the downstream side.

  The extruder 14 has a cross head 15 through which the wire 1 passes and a hopper 16 that stores resin (pellet). The resin charged in the hopper 16 is sent to a cylinder (not shown), and the cylinder In the melt. The extruder 14 has a screw (not shown) inside, and when the screw rotates, the molten resin in the cylinder is fed into the cross head 15 and the resin is pushed out from the cross head 15. Therefore, in the extruder 14, the extrusion flow rate of the resin extruded from the cross head 15 is determined by the rotation of the screw. The crosshead 15 is disposed sideways, and when the wire 1 passes through the crosshead 15, the molten resin fed by the screw is pushed out from the crosshead 15. As a result, the wire 1 is covered with the resin to form the electric wire C.

  An outer diameter measuring device 21 is provided on the downstream side of the extruder 14, and the outer diameter measuring device 21 measures the outer diameter of the passing electric wire C and transmits it to a control device (not shown). As the outer diameter measuring instrument 21, for example, a laser measuring instrument that measures the outer diameter of the electric wire C in a non-contact manner using laser light is used.

  A cooling device 22 is provided on the downstream side of the outer diameter measuring device 21. The cooling device 22 is, for example, a water-cooled type, and the electric wire C passing through the cooling device 22 is cooled by the cooling device 22 and the resin coated on the wire 1 is cured.

  On the downstream side of the cooling device 22, a take-up roller 23 for taking up the electric wire C is provided. The take-up roller 23 is controlled by a control device and takes up the electric wire C at a predetermined linear velocity.

  A storage device 25 is provided on the downstream side of the take-up roller 23. The accumulator 25 has movable rollers 26 arranged vertically, and an electric wire C is wound around these movable rollers 26. The movable rollers 26 are supported so as to be close to and away from each other, and the lengths of the electric wires C wound and stored around the movable rollers 26 are adjusted by the proximity and separation of these movable rollers 26 to change the interval. The A guide roller 27 is provided between the movable rollers 26 on the upstream side and the downstream side, and the electric wire C is guided to the upper movable roller 26 by the upstream guide roller 27, and the downstream guide roller 27. Thus, the electric wire C from the lower movable roller 26 is guided downstream.

  A guide roller 28 is provided on the downstream side of the wire accumulator 25, and the electric wire C is guided to the winding bobbin 29 by the guide roller 28. The take-up bobbin 29 is a bobbin that takes up the electric wire C, and when the set-length electric wire C is taken up, the take-up bobbin 29 is switched to another take-up bobbin 29.

  In the manufacturing apparatus 11 described above, the path line of the electric wire C until the electric wire C on the downstream side of the extruder 14 is wound around the winding bobbin 29 is several tens of meters or more, for example, about 100 m.

  In the manufacturing apparatus 11 described above, the wire 1 is taken out by the take-off roller 23, thereby feeding the wire 1 from the feeding bobbin 12, and passing the wire 1 to the cross head 15 of the extruder 14. Thereby, the resin is pushed out from the cross head 15 around the wire 1, and thus the electric wire C in which the resin 1 is coated around the wire 1 is manufactured.

On the downstream side of the extruder 14, the outer diameter of the electric wire C is measured by the outer diameter measuring device 21. In order to keep the outer diameter of the electric wire C to be manufactured constant, the control device performs drive control of the take-up roller 23 or the screw of the extruder based on the measurement result of the outer diameter measuring device 21, and the linear velocity of the wire 1. The outer diameter is controlled to control.
The electric wire C taken up by the take-up roller 23 is wound and stored on the movable roller 26 of the accumulator 25, and then taken up on the take-up bobbin 29.

  Next, stop control for manufacturing the next electric wire C after manufacturing the electric wire C having a set length which is the length of the manufacturing request will be described based on the flowchart shown in FIG.

While the covering control for manufacturing the electric wire C is being executed (step S01), the control device detects the amount of resin supplied to the cylinder of the extruder 14 and satisfies the following condition, and then applies the control to the cylinder of the extruder 14 A material supply stop process for stopping the supply of resin is performed (step S02).
(Standard setting value-Effective production length with remaining cylinder capacity-Pass line length) ≤ Current production length Here, the current production length is the length of the wire wound around the current take-up bobbin, and the pass line length. Is the length from the exit of the crosshead 15 to the take-up bobbin 29.

The effective production length with the remaining amount of cylinder is calculated from the following equation based on the screw rotation speed.
Cylinder effective remaining amount (rev) x solid line speed (m / min) / actual screw speed (rev / min)
The cylinder effective remaining amount is expressed by the number of rotations of the screw necessary to advance the screw to the remaining cylinders.

  In the material supply stop process (step S02), the blending apparatus for blending the resin supplied to the extruder 14 is stopped.

  Moreover, in the extruder 14, preparation for material replacement is performed. In preparation for material replacement in the extruder 14, the hopper 16 of the extruder 14 that has been performing normal operation (see FIG. 3A) moves, and the hopper 16 is connected to the discharge pipe 31. Then, the resin in the hopper 16 is collected into the collection box 32 through the discharge pipe 31 (see FIG. 3B). Thereafter, the hopper 16 moves in the reverse direction and is disposed at a neutral position between the discharge pipe 31 and the cylinder. In this state, the resin to be used next is charged (see FIG. 3C). Thus, by preparing the resin to be used next in the hopper 16 in advance, the stop time when switching to the production of a new electric wire C can be shortened as much as possible, and the productivity is increased. Can do.

After the material supply stop process (step S02), the control device confirms that the following conditions are satisfied, and starts the lower limit linear velocity coating operation (step S03).
(Standard setting value-Travel length from current line speed to lower limit line speed)> Current production length

  The lower limit linear velocity covering operation is an operation state in which the wire 1 is coated with a resin at a lower linear velocity than the steady linear velocity, and is the lower limit linear velocity at which a good electric wire C can be manufactured. The lower limit of the linear velocity is a linear velocity that has been empirically confirmed to be good in terms of electrical characteristics and mechanical characteristics. For example, the linear velocity is 1/6 to 1/3 of the steady linear velocity. Since the linear velocity after stopping the material supply is preferably as small as possible, a linear velocity close to the lower limit is preferable, but in the strict sense, the lower limit is not required, and the linear velocity is slightly larger than the lower limit and is a steady line. It may be lower than the speed. In addition to the lower limit linear velocity covering operation, an outer diameter control response changing process (step S04) is performed to increase the response speed of the outer diameter control of the electric wire C in accordance with the rotational change of the screw of the extruder 14.

  When the supply of the resin to the cylinder of the extruder 14 is stopped, the resin in the cylinder is pushed out and reduced. As a result, the extrusion pressure of the resin from the cross head 15 decreases. For this reason, when the electric wire C is manufactured at a steady line speed, the outer diameter of the manufactured electric wire C becomes thin.

  Therefore, in the lower limit linear velocity covering operation after the material supply stop process, the linear velocity of the wire 1 is set to the lower limit linear velocity, and the response speed of the outer diameter control is increased. Thereby, even after the material supply is stopped, the outer diameter of the electric wire C can be maintained at the target outer diameter to be a good product.

The control device confirms that the following condition is satisfied, and determines that the production of the electric wire C currently being manufactured is completed (step S05).
(Standard setting value−pass line length) ≦ current production length This condition means that the set length of the electric wire C has been pushed out (from the outlet of the crosshead 15).

  When it is determined that the production is complete, the control device performs subsequent stop switching control. If the control device is set to the pass line remaining stop mode, a pass line remaining stop process is performed (step S06). In this pass line remaining stop mode, the resin 14 is coated on the wire 1 by the extruder 14 while leaving the non-defective wire C having the outer diameter set to the target outer diameter on the pass line of the electric wire C downstream of the extruder 14. It is a mode to stop. Note that the line may be stopped without entering the pass line remaining stop mode. The pass line remaining stop mode can be set by a switch or the like. For example, if the button switch pressing time for mode setting is 2 seconds or longer, the button is set to the pass line remaining stop mode, and if it is less than 2 seconds, the button is set not to be set to the pass line remaining stop mode. The setting may be performed according to the switch pressing time.

  Further, the control device stops the outer diameter control (step S07). Since the extruder 14 has a small amount of resin in the cylinder, the number of rotations of the screw increases. Therefore, it is preferable to stop the extruder 14 when the outer diameter control is stopped. If the extrusion of the resin is stopped by the extruder 14, the marking roller may be damaged by the wire 1. Therefore, the marking roller is preferably moved to a position away from the wire 1.

  The drive of the take-up roller 23 is controlled, the wire speed of the wire 1 is reduced, and the winding bobbin 29 and the feeding bobbin 12 are completely stopped (step S08). The deceleration stop of the wire 1 is preferably performed as fast as possible within a range where the wire 1 is not disconnected. When the linear velocity is 100 m / min or less, the disconnection detection is stopped and the extruder 14 is stopped. Thereby, the backflow of the resin in the extruder 14 can be prevented, and unnecessary detection processing can be made unnecessary.

It is confirmed that the line has stopped (step S09). In this state, the electric wire C manufactured as a non-defective product remains on the pass line without being wound up.
Subsequently, extrusion of a new resin for coating the electric wire C by the extruder 14 is started. As described with reference to FIG. 3, when the resin to be used next is put into the hopper, a line type switching process for starting production of a new electric wire C by the outer diameter control operation is performed (step S10).

  In addition, when starting manufacture of the new electric wire C by changing the material, the extruder 14 moves the hopper 16 into which the new material is charged as shown in FIG. The coating resin is supplied to the cylinder, the initial resin supplied to the cylinder is overflowed and discharged to the hose 33. As a result, the resin used last time remaining in the flow path of the crosshead 15 from the cylinder is discharged, and when the molten resin that the flow path of the crosshead 15 is newly pushed out from the cylinder is filled, stop discharging the resin, The extrusion of resin from the crosshead 15 is started (see FIG. 3E).

When the driving of the take-up roller 23 is resumed and the feeding bobbin 12 and the take-up bobbin 29 are rotated and the electric wire C remaining on the pass line is taken up by the take-up bobbin 29, the control device satisfies the following conditions: Then, a bobbin replacement process for switching to an empty winding bobbin 29 is performed (step S11).
Standard setting value ≦ current production length Specifically, the non-defective electric wire C remaining on the pass line is reliably wound around the winding bobbin 29 and stopped, and then switched to the empty winding bobbin 29. In this case, when switching to the empty winding bobbin 29 in the bobbin switching process, the electric wire C flowing through the pass line is stored in the upstream storage device 25. After that, the wire of another coating material manufactured on the new bobbin 29 is wound up.

Next, a flow for stopping the equipment without leaving an electric wire on the pass line will be described with reference to FIG. Differences from the above flow will be mainly described.
The material supply is stopped (step S02), the linear speed is lowered to the lower limit speed (step S03), the response speed of the outer diameter control is increased (step S04), and the extrusion of the set length of the electric wire C is completed (step S05). Then, the outer diameter control is stopped (step S07). Then, the driving of the take-up roller 23 is stopped, the line is decelerated, and the feeding bobbin 12 and the take-up bobbin 29 are stopped (step S08). At this time, the winding bobbin 29 is stopped by decelerating the line so that all the electric wires C of the pass line are wound around the winding bobbin 29.
When the line is stopped (step S09), the take-up bobbin 29 is replaced (step S12).

FIG. 5 is a graph showing a change in the extrusion flow rate R of the resin in the extruder 14 in the stop control.
As shown in FIG. 5, when the material supply stop process (step S02) is started (Ta) and the lower limit linear velocity coating operation (step S03) is started (Tb), the screw rotation speed gradually decreases and the extrusion flow rate is reduced. R also goes down. When the linear velocity of the wire 1 becomes the lower limit linear velocity (Tc), the number of rotations of the screw becomes constant and the extrusion flow rate R becomes constant. Thereafter, as the resin remaining amount in the cylinder decreases, the extrusion pressure of the resin decreases. Therefore, when the outer diameter control is fed back to the screw rotation speed, the rotation speed of the cylinder varies finely. When it is determined that the production is completed (step S05) (Td) and the drive of the take-up roller 23 is decelerated and stopped (step S08), the screw rotation is also stopped (Te), and the extrusion flow rate R becomes 0 (Tf).

  Thus, according to the present embodiment, the resin is applied to the wire at the lower limit linear velocity lower than the steady linear velocity from the time point (Ta) at which the material supply is stopped to the time point (Td) at which the production is stopped. The resin remaining in the extruder 14 (FIG. 5) is shifted to the lower limit linear velocity coating operation to increase the response speed of the outer diameter control of the electric wire C in accordance with the extrusion flow rate R of the resin from the extruder 14. The electric wire C manufactured by the resin in the hatched portion from the middle Ta to Td) can be a good product with a stable outer diameter.

  In the above embodiment, the case where one type of resin is coated on the outer periphery of the wire 1 has been described as an example. However, a sub crosshead is provided in tandem on the downstream side of the main crosshead, and the main resin is provided. Alternatively, a sub-extrusion type extruder 14 that covers a sub-resin such as a coloring material after coating may be used.

  In the manufacture of the electric wire C using the sub-extrusion type extruder 14, the next stop control of the above embodiment is applied when switching to the manufacture of a new electric wire C having a different sub resin after the electric wire C having a set length is manufactured. can do.

  In the case of using this sub-push type extruder 14, the outer diameter control is fed back to the rotational speed of the screw that pushes out the main resin during operation at a steady linear speed. When the supply of the sub resin is stopped to change the sub resin material, the outer diameter control after the material supply is stopped is fed back to the rotation speed of the screw that extrudes the sub resin.

1: Wire rod, 14: Extruder, 29: Winding bobbin, C: Electric wire, R: Extrusion flow rate

Claims (3)

A method for producing an electric wire produced by performing an outer diameter control for controlling the wire speed of the wire such that the outer diameter of the electric wire is coated with a resin on the outer circumference of the wire,
A material supply stop process for detecting that the amount of resin required for coating the wire of the remaining length until the set length is supplied to the extruder and stopping the supply of the resin to the extruder;
After stopping the supply of the resin to the extruder, the wire speed switching process for shifting to the lower limit linear speed coating operation in which the wire is coated with the resin at a low linear speed lower than the normal linear speed and higher than the lower limit linear speed. When,
After stopping the supply of resin to the extruder, an outer diameter control response changing process for increasing the response speed of the outer diameter control of the electric wire according to the extrusion flow rate of the resin from the extruder,
Outer diameter control stop processing for stopping the outer diameter control when the electric wire is pushed out for a set length;
The manufacturing method of the electric wire characterized by including. It is a manufacturing method of the electric wire according to claim 1,
A method of manufacturing an electric wire, comprising: a bobbin replacement process in which an electric wire left on a pass line after the outer diameter control stop process is wound on a take-up bobbin to stop travel of the wire and replace the take-up bobbin . It is a manufacturing method of the electric wire according to claim 1,
The wire covered with the newly supplied resin by stopping the running of the wire together with the outer diameter control stop process, and then supplying the resin for covering the new wire to the extruder and running the wire. Line type switching processing to switch to manufacturing
A bobbin exchange process for replacing the take-up bobbin when the electric wire left on the pass line is taken up by the take-up bobbin;
The manufacturing method of the electric wire characterized by including.

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