JPS604346Y2 - Electric cable manufacturing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for manufacturing an electric cable in which an inner semiconducting layer, an insulating layer, and an outer semiconducting layer are sequentially provided on a conductor.

In such electric cable manufacturing equipment, it is necessary to measure the thickness of the coating layer to prevent deflection.

It is desirable to measure this wall thickness immediately after extrusion coating in order to reduce extrusion loss.

By the way, what is affected during cable connection processing is the total thickness of the internal semiconducting layer and the insulating layer, and what is particularly problematic is the thickness of the insulating layer, which is significantly thicker than the internal semiconducting layer. be.

The deflection rate of the total wall thickness of both (minimum wall thickness/maximum wall thickness) is 90
% or more, preferably 95% or more.

The thickness of the outer semiconducting layer is more conductive than that of the insulating layer, and does not have a large effect on the cable connection process, so the deflection rate may be 70 to 80%.

Therefore, the total thickness of the internal semiconducting layer and the insulating layer is measured,
It is necessary to monitor whether this can be maintained constant.

However, conventional electrical cable manufacturing equipment is either a three-layer extruder that simultaneously extrudes three layers, or a one-layer extruder to extrude and coat the inner semiconducting layer, and then a two-layer extruder to coat the insulating layer. co-extrusion coating with an outer semiconductive layer;
The structure was such that the resulting electrical cable was passed through the crosslinking tube immediately after the extrusion of the layer was completed to perform crosslinking, so it was not possible to measure the wall thickness immediately after extruding the insulating layer, and it was not possible to measure the wall thickness after passing through the crosslinking tube. There was a drawback that I had no choice but to do this.

For this reason, the detection of deflection is delayed, and if deflection is discovered, there is a drawback that extrusion loss increases.

Furthermore, if the deflection was discovered after passing through the cross-linking cylinder, there was a drawback that the direction of uneven thickness in the extruder could not be determined because the cable was likely to twist while passing through the cross-linking cylinder.

An object of the present invention is to provide an electric cable manufacturing apparatus that can measure thickness deviation immediately after extruding an insulating layer, and can also reliably determine the direction of deflection in the extruder.

The electric cable manufacturing apparatus according to the present invention includes a first extruder that simultaneously extrudes and coats an inner semiconductive layer and an insulating layer on the outer periphery of a conductor, and a second extruder that extrudes and coats an outer semiconductive layer on the insulating layer.
The first extruder and the second extruder are arranged with their positions shifted in the direction of conductor movement, and a wall thickness measurement sensor is arranged between the first extruder and the second extruder, and immediately after extrusion of the insulating layer, Measuring wall thickness and
This makes it possible to know the direction of deflection if it occurs.

Embodiments of the present invention will be described in detail below with reference to the drawings.

As shown in FIG. 1, in the electric cable manufacturing apparatus of this embodiment, a first extruder 4 is used to simultaneously coat the conductor 1 with an internal semiconductive layer 2 and a thicker insulating layer 3. and a second layer for extruding and coating the outer semiconducting layer 5 on the insulating layer 3.
The extruder 6 is provided with its position shifted in the direction of movement of the conductor 1.

The first extruder 4 extrudes a semiconductive material such as conductive rubber or plastic from between the nipple 7 and the internal die 8 to form the internal semiconductive layer 2, and forms the internal semiconductive layer 2 between the internal die 8 and the external die 9. The insulating layer 3 is formed by extruding an insulating material such as rubber or plastic from between the two.

The eccentricity of the external die 9 can be adjusted using an adjustment tool 10.

The second extruder 6 is configured to extrude a semiconductive material such as conductive rubber or plastic from between the nipple 11 and the die 12 to form the external semiconductive layer 5 .

The eccentricity of the die 12 can be adjusted using an adjusting tool 13.

A wall thickness measuring device 1 is provided between the first extruder 4 and the second extruder 6 to detect the total thickness of the internal semiconductive layer 2 and the insulating layer 3.
4 sensors 14A are arranged.

As the wall thickness measuring device 14, for example, an electromagnetic induction type device manufactured by Zumbatsch is used.

The sensor 14A can be made non-contact based on the principle of an air micrometer.

A crosslinking cylinder 15 is connected to the outlet side of the second extruder 6, and is configured to crosslink an electric cable 16 coming out of the second extruder 6.

In this way, from the first extruder 4 to the second extruder 6
During this period, the total thickness of the insulating layer 3 and the internal semiconducting layer 2 can be measured.

In this case, the presence or absence of deflection can be checked by arranging the sensors 14A at 90° intervals or by rotating the sensors 14A.

Since this inspection is performed immediately after extrusion of the insulating layer 3, deflection can be detected quickly, and extrusion loss can be minimized by stopping extrusion when deflection is detected.

Furthermore, since the deflection can be detected before the cable 16 is twisted, the direction of deflection of the extruder 4 can be immediately determined and can be easily adjusted using the adjustment tool 10.

FIG. 2 shows the principle of the inductive wall thickness measuring device 14.

Sensor 1 for detecting the wall thickness of cable 16 as shown
4A is arranged opposite to the cable 16.

On the other hand, a monitoring sensor 14B is disposed so as to be displaced by the nominal thickness with respect to the bare wire sample conductor 17.

Each sensor 14A, 14B is provided with a coil that is magnetically coupled to the conductor 1, 17, and outputs an oscillation frequency depending on the coupling state.

That is, the sensor 14A outputs a frequency output according to the wall thickness, and the sensor 14B outputs a reference monitor frequency.

The output of each sensor 14A, 14B is the frequency comparator 14C
By comparing the two frequencies and taking the difference frequency 4f between the image frequencies, the change Δt in the wall thickness of the cable 16 can be measured.

The deflection and its direction can be detected by rotating the sensor 14A around the cable 16 or by using a plurality of sensors 14A and switching them to the frequency comparator 14C.

Note that the second extruder 6 can also be a two-layer extruder that extrudes the outer semiconductive layer and the plastic sheath at the same time.

Alternatively, the guiland portion of the external die 9 in the first extruder 4 may be made of an insulating material into a ring shape, and the sensor 14A may be placed in contact with the outer periphery of the ring.

As explained above, the electric cable manufacturing apparatus according to the present invention includes a first extruder that extrudes the internal semiconductive layer and the insulating layer;
The extruder is separated into a second extruder for extruding the outer semiconductive layer,
Since a wall thickness measurement sensor is installed between both extruders, the wall thickness of the internal semiconductive layer and the insulating layer can be measured immediately after extrusion, and deflection can be detected quickly. It is possible to minimize the occurrence of extrusion loss due to

In addition, according to the present invention, uneven thickness is detected before the cable is twisted, so the direction of deflection of the extruder can be immediately determined.
Modifications can be easily made.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view of a main part showing an embodiment of an electric cable manufacturing apparatus according to the present invention, and FIG. 2 is a block diagram showing the principle of a wall thickness measuring device. 1... Conductor, 2... Internal semiconducting layer 3
...Insulating layer, 4...First extruder, 5
......Outer semiconductive layer, 6...Second extruder, 14...Thickness measuring device, 14A...
Wall thickness measuring device sensor, 16...cable. 15...Bridge tube,

Claims (1)

[Scope of utility model registration request] A first extruder that extrudes and coats an inner semiconductive layer and an insulating layer on the outer periphery of the conductor at the same time, and a second extruder that extrudes and coats an outer semiconductive layer on the insulating layer are arranged in a direction in which the conductor travels. A wall thickness measuring sensor for measuring the wall thickness of the internal semiconductive layer and the insulating layer is arranged between the first extruder and the second extruder. An electric cable manufacturing device characterized by: