JPS5826604B2 - Seizou Souchi - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for manufacturing insulated wires, particularly for high-speed extrusion of foamed plastic insulated wires.

The present invention relates to manufacturing equipment that can be effectively utilized.

Generally, the capacitance C of a foamed plastic insulated wire is given by the following equation (1).

In the above formula (1), ε; dielectric constant D that depends on the material of the coating resin and its degree of foaming; outer diameter d of the foamed plastic insulation coating layer; diameter of the conductor.

The above equation (1) shows that the capacitance C is controlled by the dielectric constant ε, the outer diameter of the coating layer, and the conductor diameter d, and the capacitance C2 is controlled by the dielectric constant ε, the outer diameter, and the conductor diameter. It is desirable to keep d as constant as possible.

The conductor diameter d is considered to be almost constant under the same conditions in the same manufacturing lot and the same manufacturing machine, but depending on the manufacturing lot,
It may vary depending on the manufacturing machine.

Especially in recent years, when foamed plastic insulated wires are manufactured at high speed through a series of processes including wire drawing, annealing, extrusion coating, and one winding, the conductor diameter d is based on the upward diameter of the wire drawing machine. In this case, the diameter thinning during the annealing process, the diameter thinning due to the tension between the extrusion process and the drawing process, etc. are added, and the narrowing △
d.

Even if it is possible to make the conditions of manufacturing lots and the performance of manufacturing machines as close to the same as possible in this narrowing Δd, it is inevitable that slight differences will occur between manufacturing lots and machines.

In this way, for each conductor having a difference in conductor diameter d from lot to lot,
Even if the capacitance C is controlled to be constant and a foamed plastic coating is applied to each wire, the outer diameter of the coating and the dielectric constant ε will differ for each wire, and the electrical 2 mechanical properties of the wire 1 It's not right.

Therefore, the conductor diameter d is constant for each lot, and the capacitance C
2. By controlling the outer diameter of the coating, a foamed plastic insulated wire with a constant dielectric constant ε and uniform performance can be obtained.

Therefore, the main object of the present invention is to provide an apparatus for manufacturing an insulated wire that can relatively easily control the narrowing of the conductor diameter.

In summary, this invention focuses on the fact that the narrowing is correlated with the length of the cooling water tank, and the cooling water tank is made expandable and contractible, and the length of the cooling water tank is controlled by measuring the narrowing. It is.

The above objects and other objects and features of the invention will become more apparent from the following detailed description with reference to the drawings.

1. Under the conditions of
Looking at the relationship between and the length l of the cooling water tank, we experimentally found the following equation (
2) is obtained.

△d224・(To+1.3v21/3500)2keo, the above formula (2) 7, -(2)kl
, kv: constant, V: linear velocity CKm15)), To: tension applied to the wire after extrusion (g, l, l: length of cooling water tank, m)
It is.

From this formula (2), if the annealing conditions and linear velocity V are constant,
constant, , 2 and tension T.

is also constant, and it can be seen that the narrowing Δd is a function only of the cooling water tank length l.

Therefore, in manufacturing foamed plastic insulated electric wires, the conductor diameter d of the finished wire is measured, and the water tank length l is controlled to obtain a predetermined diameter d.

Furthermore, the outer diameter of the coating layer is kept constant,
Thus, the dielectric constant, ie, the capacitance C, can be controlled to be constant.

FIG. 1 is an illustrative diagram showing the configuration of a preferred embodiment of the present invention.

In this structure, a foamed plastic insulation coating layer 22 in a high temperature melted and softened state is formed on the entire outer circumference of a conductor 21 by an extruder 1.

The extruded electric wire 20 passes through the cooling water tank 300, whose longitudinal cross section is shown in this figure, and passes through the coating layer 2.
The surface of the conductor 21 is hardened and cooled in the interior 1 of the conductor 21 by a cooling tank (not shown) provided after the cooling water tank, and then taken up by a take-up device 9 and wound up one after another at a certain speed.

As will be described in detail later, the cooling water tank 300 is formed to be extendable and retractable, and has one end fixed by a support leg 41 and the other end fixed by a support leg 42 and a first movement for driving the support leg 42 to move. It is made movable by a drive system 43.

Further, the support legs 41 and 42 are both placed on one moving table 7.

The movable table 7 is made movable by a second movable drive system 71.71 that drives the movable table 7 to move.

A cooling tank (not shown) following the cooling water tank 300 includes a wire capacitance measuring device 8, and the capacitance C of the wire is measured and detected.

The measured capacitance value from this measuring device 8 is given to a setting control circuit 10.

The setting control circuit 10 controls the second moving drive system 71.71 based on the deviation between the input capacitance value of the electric wire 20 and a preset capacitance value, and accordingly The movement (position) of the entire cooling water tank 300 is controlled.

The first movable drive system 43 that has been cut is connected to the drive control circuit 11.
Drive controlled by.

The cooling water tank 300 described above has a surrounding wall 301 made of a flexible material such as rubber or synthetic resin (reinforced with metal, glass fiber, etc. if desired), and is configured in the form of a corrugated bellows. .

Note that the cooling water tank 300 may be in the form of a telescope.

Therefore, it will be understood that this peripheral wall 301 is made telescopic.

Furthermore, side walls 303 and 304 are fixedly disposed at both ends of the peripheral wall 301 to form a cooling water tank.

Surrounding wall 301 and side walls 303, 30 of the cooling water tank 300
Cooling water 6 is continuously supplied and filled into the internal cavity defined by 4 and 4.

For this purpose, a cooling water supply port 302 for pressurized injection of the cooling water 6 is formed in the upper part of the surrounding wall 301, and a cooling water source (not shown) is connected to this supply port 302.

On the other hand, side walls 306 and 308 are further formed on the outside of the side wall 303 and integrally with the side wall 303 at the lower part thereof.

The distance between the one side wall 303 and the side wall 306 and the side wall 3
The distance between 06 and 308 is determined by felt 51, which will be described later.
> and 52 are used as felt insertion grooves 307 and 309 whose width is selected to allow intimate insertion.

The lower part (bottom) of these felt insertion grooves 307 and 309
flows out from the inside to the felts 51 and 52,
Drain ports 310 and 3 for discharging infiltrated cooling water
11 is formed.

Furthermore, each of the side walls 303, 306 and 308 includes
An inlet 305 having an inner diameter of "wire diameter + quantity" and communicating with each side wall as a through-entrance for the electric wire 20 to be cooled is formed.

The other (right side in the figure) side wall 304 forms an outlet 312 that serves as a through-outlet for the cooled electric wire and has an inner diameter of the wire diameter + several square meters, and is gradually inclined toward the outlet 312. be done.

On the outside of this side wall 304, a side wall 313 is further formed integrally with the side wall 304 at its lower part, and a felt insertion groove 314 for inserting the felt 53 is formed therein.

A discharge port 315 is formed at the bottom of the felt insertion groove 314 for discharging the cooling water that has permeated the felt 53 from the inside, and an outlet 312 is formed in the side wall 313 in communication with the outlet 312 .

Further, the ferns 51, 52 and 53 have a shape substantially similar to the cross-sectional shape of the side walls 303 and 304, and are made of a multi-fibrous material.

The felts 51 and 52 are provided with a hole whose inner diameter is approximately equal to the wire diameter of the electric wire 20 at a position corresponding to the entrance 305 when inserted into the insertion grooves 307 and 309. A hole whose inner diameter is approximately equal to the wire diameter is provided at a position corresponding to the outlet 312 when inserted into the insertion groove 314.

In this way, the cooling water tank 30 as a feature of the present invention
0 is formed.

The operation of the above configuration will be explained below.

Electric wire 20 with foamed plastic insulation coating layer 22 formed thereon
starts foaming when it leaves the extruder 1, and then enters the cooling water tank 30.
Cooled by 0.

Therefore, the coating layer 22 begins to cool and harden.

In general, the coating layer 22 defines the dielectric constant and therefore the capacitance of the wire 20 depending on its material and foaming rate.

Therefore, in a preferred embodiment of the present invention, the cooling water tank 300 is used as a moving water tank, and the cooling hardening start position is changed accordingly, so that the foaming rate of the coating layer 220 and the foaming rate of the coating layer 22 are changed accordingly.
control the outer diameter of

For example, when the cooling water tank 300 is close to the extruder 1, the foamed coating layer 22 is rapidly cooled and hardened, and therefore the foaming rate (outer diameter of the coating layer) is small.

Therefore, the dielectric constant of this coating layer 22 becomes large, and the electric wire 2
0 capacitance increases.

On the contrary, the cooling water tank 300 separates from the extruder 1, and the cooling start point of the foamed coating layer 22 is delayed, so that the foaming rate (outer diameter of the coating layer) is large.

Therefore, the dielectric constant of this coating layer 22 becomes small, and the electric wire 2
The capacitance of 0 becomes small.

Therefore, when a deviation occurs between the capacitance detected by the capacitance measuring device 8 and the preset capacitance value, the setting control circuit 10 detects the sign (direction) and magnitude of the deviation. derive a corresponding control signal.

Therefore, the movement drive systems 71, 71 including servo motors control the movement of the cooling water tank 300 in a direction that eliminates the deviation.

Therefore, the capacitance can be controlled regardless of the screw rotation speed of the extruder 1 or the wire take-up speed.

On the other hand, in the cooling water tank 300 which is a feature of the present invention, the cooling water 6 is injected under pressure from the cooling water supply port 302 as shown by the arrow.

Accordingly, the supplied cooling water 6 fills the internal cavity of the tank and eventually overflows from the inlet 305 and outlet 312.
It comes out due to the supply pressure.

Therefore, no air enters the cooling water tank 300 with the moving electric wire 20, and accordingly, irregularly shaped bubbles are not generated at the cooling start position, and the velocity gradient (
(due to the viscosity of water) also disappears.

Therefore, small fluctuations in the cooling start position are eliminated.

However, the torrent of cooling water toward the inlet 305 side is undesirable because it further causes fluctuations in the cooling point or scatters toward the die side.

Therefore, it is desirable to block this torrent of cooling water toward the inlet at a certain position to weaken its force and cause it to overflow.

For that purpose, the preferred embodiment of the invention includes felts 51 and 52 inserted into the inlet 305 side.

Therefore, the cooling water flowing toward the inlet 305 side is removed from the insertion groove 305.
It collides with felts 51 and 52 inserted in γ and 309.

Therefore, the torrent is weakened, penetrates the felts 51 and 52, is discharged from the drain ports 308 and 309 at the bottom, and flows down along the side wall 308.

The cooling water flowing down along this side wall 307 has a weak outflow force and does not scatter toward the dice side.

Therefore, the electric wire 20 to be cooled is always made of felt (5
1 and ) 52, cooling will begin.

Since the felts 51 and 52 are multi-fibrous, they have good water permeability and are soft, so even if the electric wire 20 comes into contact with them, the coating layer 22 of the electric wire 20 will not be damaged.

In this way, since the electric wire 20 starts cooling at a fixed position in the cooling water tank 300, the wave of instantaneous disturbance in capacitance caused by fluctuations in the cooling point is further removed, and the capacitance is reduced over the entire line. A stable foamed plastic insulated wire can be obtained.

In this way, capacitance control during the cooling process is achieved.

Furthermore, in the embodiment of the present invention, the diameter of the conductor 21 of the electric wire 20 wound up by the take-up device 9 (after the coating process has been completed) and the diameter of the conductor 21 just before being put into the extruder 1 (coating process) are is measured, and the aforementioned narrowing Δd is determined.

This narrowing Δd is converted into an input condition for the drive control circuit 11, for example, according to a table (not shown) in which the extent of expansion and contraction of the cooling water tank length l is set in advance in accordance with this Δd.

Therefore, the drive control circuit 11 controls the moving drive system 43 so that the water tank length (Equation (2)) is correlated to the narrowing Δd.

For example, if the shrinkage Δd is larger than the preset value Δdo, the moving drive system 43 is controlled so that the end of the cooling water tank 300 on the side of the drawing device 9 contracts with respect to the end of the cooling water tank 300 on the side of the extruder 1. The thinning Δd is a preset value d.

If it is smaller, the moving drive system 43 is removed so that the end of the cooling water tank 300 on the extruder side extends in the opposite direction.

In this way, from the relationship in equation (2) above, the narrowing △
d and therefore the diameter d of the center conductor 21 is controlled to be constant.

This control need only be performed when the device starts operating, and once the device starts operating normally, the reduction Δd becomes constant.

However, in the present invention, it is of course possible to control the button even during operation if the narrowing Δd changes for some reason during operation.

An apparatus suitable for this case is shown in FIG.

FIG. 2 is an illustrative diagram showing the configuration of another preferred embodiment of the present invention.

This embodiment is substantially similar to the embodiment of FIG. 1, except as follows.

That is, the extruder 1 is provided with a first diameter measuring device 1a for continuously measuring the diameter of the conductor immediately before it is applied to the coating process, and the take-off device 9 is equipped with a first diameter measuring device 1a for continuously measuring the diameter of the conductor immediately before being applied to the coating process, and the take-off device 9 is equipped with a first diameter measuring device 1a for continuously measuring the diameter of the conductor immediately before being applied to the coating process, and the take-off device 9 is equipped with a first diameter measuring device 1a for continuously measuring the diameter of the conductor immediately before it is applied to the coating process, and the withdrawal device 9 is provided with a first diameter measuring device 1a for continuously measuring the diameter of the conductor immediately before it is applied to the coating process, and the take-off device 9 is provided with a first diameter measuring device 1a for continuously measuring the diameter of the conductor immediately before it is applied to the coating process.
A second diameter measuring device 9a for continuously measuring the conductor diameter of
is provided.

These diameter measuring devices 1a can be used as normal ones because they can directly measure the diameter of the conductor, and the diameter measuring device 9a can be used with a coating layer on the conductor, so for example, radiation or laser can be used. A device that measures the conductor diameter is used.

Measured values from the two diameter measuring devices 1a and 9a are provided to a setting control circuit 12.

This setting control circuit 12 calculates the narrowing Δd by receiving the two diameter measurement values, and calculates the narrowing Δd and the preset narrowing Δd.
A control input corresponding to o is given to the drive control circuit 11.

Therefore, the drive control circuit 11 drives and controls the moving drive system 43 according to the control input, that is, the narrowing Δd.

In other words, in this embodiment, the conductor diameter is automatically measured and the length of the cooling water tank 300 is automatically expanded or contracted according to this measured value.

In addition, in the above-mentioned embodiment, the expandable cooling water tank 3
00 is a closed type, and the cooling water is pressurized, but this is done by making the water tank deeper and opening the top, so that the water pressure of the supplied and stored cooling water causes it to flow to the inlet side (and outlet side). Good too.

Further, in the above embodiment, the outer diameter of the coating is controlled by using a movable water tank, but it is of course possible to use a fixed cooling water tank whose outer diameter is controlled by the rotational speed of the screw.

Furthermore, the present invention can be applied to the production of ordinary insulation-covered electric wires in addition to foamed plastic insulation-covered electric wires.

As described above, according to the present invention, the cooling means side end can be expanded and contracted with respect to the extruder side end of the movable water tank which is movably provided in order to keep the capacitance of the insulating coating constant. The cooling means side end of the mobile cooling water tank expands and contracts depending on the degree of conductor thinning of the electric wire, so the thinning of the conductor can be easily controlled, and the conductor diameter is uniform throughout the entire wire for each production lot. Moreover, an insulated wire with uniform capacitance, uniform outer diameter of the insulating coating layer, and dielectric constant can be obtained.

[Brief explanation of the drawing]

FIG. 1 is an illustrative diagram showing the configuration of a preferred embodiment of the present invention. FIG. 2 is an illustrative diagram showing the configuration of another preferred embodiment of the present invention. In the figure, 1 is an extruder, 20 is an electric wire, 21 is a conductor, 2
2 is an insulated drive system, 300 is a cooling water tank, 43.71 is a mobile drive system, 8 is a wire capacity measuring device, 9 is a take-off device, 10° 12 is a setting control circuit, 1 is a drive control circuit, a. 9a is a diameter measuring device.

Claims (1)

[Claims] 1. An extruder for forming an insulating coating layer on a conductor; a mobile cooling water tank that cools the electric wire by passing it through; a cooling means that is fixedly provided and further cools the electric wire that has passed through the mobile cooling water tank; and a taking-off means that takes over the electric wire cooled by the cooling means. In an apparatus for producing an insulated electric wire, the movable cooling water tank is configured such that the cooling means side end is expandable and retractable with respect to the extruder side end, and the electric wire extends through the cooling water tank. An apparatus for manufacturing an insulated electric wire, comprising a control means for controlling an end portion of the movable cooling water tank on the side of the cooling means to expand or contract in accordance with the degree of thinning of the conductor in the portion.