JPS61112934A - Measurement of temperature at manufacture time of cable - Google Patents

Abstract

PURPOSE:To make it possible to electrically detect the variation in the temp. applied to a cable core at the time of an extrusion coating process as the change in the resistance value of a thermistor through insulated core wires, by connecting a thermistor between an arbitrary of cable cores comprising plural insulated core wires. CONSTITUTION:At first, in the feed-out terminal side of the cable core 1 wound around a feed-out drum 2, insulating layers of a pair of arbitrarily measured insulated core wire 1A, 1A are partially removed to partially expose conductors 1a, 1a and a thermistor 16 is connected to the exposed parts. Next, constant voltage is applied to a pair of conductors 1a, 1a by a measuring circuit (Wheatstone bridge) 15 through lead wires 14, 14, brushes 13, 13 and rings 11A, 11A. At the point of time when the cable core 1 passes, the variation in the temp. applied to the cable core 1 is continuously detected on the basis of the change in the resistance value of the thermistor 16. After the measurement of temp., only the terminal part of a cable, into which the thermistor 16 was inserted, is cut and removed.

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to a method for measuring the temperature applied to a cable core during a sheath extrusion coating process.

(Technical Background of the Invention) When extruding a sheath onto a cable core, the extrusion temperature of the extruder, etc. is measured while measuring the temperature applied to the cable core as it passes through an extruder, vulcanization tank, etc. By controlling this, a sheath having predetermined characteristics can be extruded onto the cable core, and therefore a cable with stable quality can be obtained.

Now, as a method for measuring the temperature applied to a cable core, conventionally, a thermocouple is attached to a cable core made by twisting a plurality of insulated core wires, and a long compensating conductor wire connected to the thermocouple is inserted into the cable 6. Alternatively, the thermoelectromotive force of the thermocouple can be changed by disposing it along the cable core on the circumferential side thereof, and the thermoelectromotive force of the thermocouple is changed by the temperature fluctuation applied to the cable core during the extrusion coating process, and this change can be detected via the compensation conductor. The temperature applied to the cable core is measured.

(Problems with the Background Art) However, when using a thermocouple, as mentioned above, it is necessary to insert a long compensating conductor into the cable 6 or arrange it around the cable core. The resulting cable cannot be used as a product as it is; in other words, the resulting cable cannot be commercialized unless the long portion where the compensating conductor is present is removed, and is therefore extremely uneconomical. . Furthermore, in order to reuse the thermocouple and the long compensating conductor, it is necessary to disassemble all the long parts of the cable, which takes a lot of time and effort.

(Object of the Invention) An object of the present invention is to provide a method for measuring cable core temperature during cable manufacturing, which allows the obtained cable to be used as a product almost as is.

(Summary of the Invention) The present invention connects a thermistor between any pair of insulated core wires of a cable core consisting of a plurality of insulated core wires, and changes the resistance of the thermistor by changing the temperature applied to the cable core during the extrusion coating process. is changed and this change is electrically detected via the pair of insulated core wires.

(Embodiments of the Invention) Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 3 shows the sheath extrusion coating process, in which the cable core 1 to be extruded and coated with the sheath is wound around the delivery drum 2. After the cable core 1 is delivered from the drum 2, it is dried in a drying device 3, wound around a capstan 4, and introduced into an extruder 5, where a chloroprene rubber sheath is extruded and coated. The cable core 1 coated with the chloroprene rubber sheath is then vulcanized in the vulcanization tank 6, and then guided to the hot water washing tank 7 to be cleaned, and further to the cooling water tank 8. After being cooled, it is taken up via a take-up machine 9 and wound onto a take-up drum 10.

As shown in FIG. 1, the cable core 1 is formed by twisting a plurality of insulated core wires LA.
As shown in FIG. 2, at the end of the winding around the delivery drum 2, the conductors 1a and 1a of an arbitrary pair of insulating layers tilA and LA (7) are exposed and elongated. On the other hand, a cylindrical body 11 is fixed to the rotating shaft 2A of the delivery drum 2, and this cylindrical body 11
Copper rings IIA, IIA are attached to the circumferential surface of. Brushes 13.13 held by insulating holding members 12 are in sliding contact with the rings 11A and IIA, respectively. Each brush 13.13 has a lead wire 14.1
Measuring circuit 15 including Wheatstone bridge via 4
is connected.

Next, a temperature measuring method according to the present invention will be explained.

That is, first, as shown in FIG. 1, on the sending end side of the cable core l wound around the sending drum 2
The insulating layers of the arbitrarily selected pair of insulating layers mlA and IA are partially removed to expose a portion of each conductor 1a, and a thermistor 16 is connected to the exposed portions of these conductors 1a and 1a.

Next, a constant voltage is applied by the measuring circuit 15 to the conductors 1a, 1a of the pair of insulated core wires IA, IA via the lead wire 14.14, the brush 13.13, and the rings IIA, IIA.

Next, the cable core 1 is passed through the thermistor 1 from the delivery drum 2.
6, and the sheath is extruded and coated onto the cable core l according to the extrusion coating process shown in FIG.

Now, in this extrusion coating process, when the cable core 1 passes through the drying device 3, it is heated to a high temperature, so that the resistance value of the thermistor 16 decreases. Therefore, a pair of insulated core wires I
Since a constant voltage is applied between the conductors 1a and 11 of A and LA, a current flows through these conductors 1a and 1a, and this current is measured as a detection signal via ring IIA, brush 13, and lead wire 14. It is input to the circuit 15. Therefore,
By balancing the Wheatstone bridge of this measuring circuit 15 and measuring the resistance value of the thermistor 16, the heating temperature of the cable core 1 in the drying device 3 can be detected as shown in FIG. Similarly, when the cable core l passes through the extruder 5, the vulcanization tank 6, and the hot water cleaning tank 7, the resistance value of the thermistor 16 changes in accordance with the heating temperature.
As shown in FIG. 4, the cable core 1 is
It is possible to continuously detect temperature fluctuations applied to the

By the way, the thermistor 6 is connected to each conductor 1a, 1a of the pair of insulated core wires LA, IA at the sending end side of the cable core l, and the insulated core wires IA are connected to the conductors 1a, 1a of the pair of insulated core wires LA and IA at the other end side of the cable core l.
, IA, the temperature applied during the extrusion coating process of the cable core l can be measured, as described above, without the use of compensating conductors required for thermocouples. Therefore, the cable obtained after temperature measurement is cut only at the end where the thermistor 16 is inserted.
It can be used as a product just by removing it. Further, when the thermistor 16 is to be reused, it is only necessary to disassemble the inserted portion of the thermistor 16 at the removed terminal portion and take out the thermistor, which is a very simple operation.

In the above embodiment, the thermistor 16 is connected to the conductor 1a of the pair of insulated core wires IA and IA at approximately the center of the cable core 1.
, 1a. In this case, two cables can be manufactured by dividing the obtained cable approximately at the center and removing the thermistor 16.

Further, in the embodiment described in "-", the measuring circuit 15 and the pair of insulated core wires IA, IA were electrically connected on the sending drum 2 side, but they were electrically connected on the winding drum 10 side. It's okay.

In addition, as the thermistor 16, the conductor 1a of the insulated core wire IA
By using a thermistor with a resistance value greater than that of the resistance value, measurement errors can be reduced.

(Effects of the Invention) According to the present invention, a thermistor is connected between a pair of arbitrarily selected insulated core wires in a cable core consisting of a plurality of insulated core wires, and the temperature fluctuation applied to the cable core during the extrusion coating process is By changing the resistance value of the thermistor and detecting this resistance change electrically through the pair of insulated core wires, the compensating conductor, which was conventionally required for thermocouples, can be placed inside the cable 6. The temperature applied to the cable core can be measured without being inserted along its length or disposed along the cable core.

Therefore, the cable obtained after temperature measurement can be used as a product by simply removing the portion into which the thermistor is inserted, which is very economical. Further, in order to take out the thermistor, it is only necessary to disassemble the removed cable portion, so the thermistor can be reused very easily.

[Brief explanation of drawings]

Fig. 1 is a cutaway view of the sending end of the cable core including the thermistor according to the present invention, Fig. 2 is a perspective view showing the electrical connection between the measurement circuit and the insulated core wire, and Fig. 3 is FIG. 4 is a schematic diagram showing the extrusion coating process of the sheath, and a characteristic diagram showing temperature fluctuations applied to the cable core. 1--1------Cable core, IA--1--Insulated core wire, la--1 conductor, 11A--------Ring. 15----------Measurement circuit, 16---------Thermistor.

Claims (1)

[Claims] A method for measuring the temperature applied to the running cable core in the step of running a cable core including a plurality of insulated core wires at a predetermined linear speed and extruding a sheath over the cable core, the method comprising: A thermistor is connected between a pair of insulated core wires selected as follows, and the resistance value of the thermistor is changed in accordance with the fluctuation of the temperature applied to the cable core during the extrusion coating process, and the resistance value change is A method for measuring temperature during cable manufacturing, which is characterized by electrically detecting temperature through the core wire.