JPH0414753B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a cable core wire detection device for detecting a target core wire in the middle of a multicore cable.

Conventional Technology Conventionally, in order to search for a target core wire in the middle of a multi-core cable, it is necessary to cut the cable at the location to be searched and conduct a continuity test of the internal conductor of the cable core between one end of the cable and the location to be investigated. Alternatively, the continuity test of the internal conductor of the cable core must be performed by stripping off the insulating outer sheath of the cable core at the inspection point or directly contacting the inner conductor of the core with a needle-like object that pierces the insulating outer sheath of the cable core. Nakatsuta.

However, in multi-core cables used in existing cable facilities, some of the core wires, for example 50
It is often necessary to perform branching or insertion work on the five core wires of a cable core, but the conventional cable core wire detection technology described above requires direct contact with the cable core wires. , the cable equipment must be shut down to carry out the work.

In addition, in multicore cables used in communication cable lines, some parts of the line, such as
All lines will have to be shut down due to construction work on the cable cores of five of the 50 lines.

In this way, shutting down the entire cable facility to perform work on some of the core wires of a multicore cable causes extremely large losses in terms of facility operation, and is difficult in practice. It is strongly desired to be able to perform construction on only the necessary core wires without stopping the system.

Problems to be Solved by the Invention The present invention solves the problem that in multi-core cables as described above, it is not possible to search for the target core wire without stopping the cable equipment as a whole. To provide a cable core wire detection device capable of detecting a target core wire from above the insulating outer sheath of the core wire without contacting the conductor, and capable of searching the cable core wire without stopping cable equipment.

Means for Solving the Problems In order to achieve the above object, the cable core wire detection device according to the present invention includes a probe signal transmitter that connects to the core wire at one end of the multicore cable and sends a probe signal, and A probe signal detector that detects a probe signal passing through the core wire by means of a probe coil that is contactlessly coupled to the inner conductor of the core wire from above the insulating outer sheath of the core wire in the middle of the core cable; In a cable core wire detection device that detects core wires,
The exploration signal transmitter is equipped with a signal output terminal for connecting to a plurality of core wires, and also includes a low frequency oscillator and a plurality of core wires connected to the output of the low frequency oscillator to the signal output terminal. a modulator that gives a different core wire identification code to each core wire as a probe signal;
a signal modulation controller that controls the output of the signal output amplifier to the signal output terminal in synchronization with the application of the core wire identification code, and the exploration signal detector is non-contact coupled to the internal conductor of the core wire. This configuration includes a divided current-transforming probe coil and a signal identifier that identifies the core wire through which the detected probe signal flows based on the core wire identification code of the detected probe signal.

The present invention also provides a method for connecting the probe signal transmitter to a signal output amplifier that amplifies and outputs the modulated probe signal, and between the modulator and the signal output amplifier; It can be configured to include a differential amplifier which inputs the exploration signal and the feedback signal of the amplified exploration signal and outputs the same current value level of the exploration signal.

Embodiments The invention will now be explained in detail with reference to embodiments shown in the drawings.

In FIG. 1, 1 indicates a multicore cable, and 2 indicates its many core wires. The core wire detection device according to the present invention searches for a target core wire in the middle of a cable 1, and includes a probe signal transmitter A that is connected to one end of the cable and sends a probe signal current to a plurality of core wires 2 of the cable; A probe signal detector B detects a probe signal current passing through the core wire by means of a probe coil 3 that is non-contact coupled to the inner conductor of the core wire from above the insulating outer sheath of the core wire taken out from the cable midway through the cable; and a display C that displays this when it is detected.

As shown in FIG. 2, the exploration oscillator A provides a low frequency oscillator 4 and the output signal of the low frequency oscillator 4 with a different core wire identification code for each of the plurality of connected core wires 2 to generate a exploration signal. It is composed of a modulator 4a, a signal output amplifier 5, a signal modulation controller 6 that controls the signal output amplifier 5 in synchronization with the application of a core wire identification code, and a differential amplifier 7. A probe signal is sent from the terminal 8 to the plurality of core wires 2. The differential amplifier 7 receives as input the modulated exploration signal that is the output of the modulator 4a and the feedback signal of the exploration signal amplified by the signal output amplifier 5. This is to output a constant current value level of the exploration signal without being affected by the length of the core wire 2.

As shown in FIG. 3, the signal detector B includes a split current transformer probe coil 3 that connects contactlessly with the internal conductor of the cable core, a signal amplifier 9 that amplifies the probe signal current, and a signal amplifier 9 that amplifies the probe signal current. It includes a demodulator 10 that performs demodulation, and a discriminator 11 that identifies the core wire 2 to which the probe coil 3 is coupled based on the demodulated signal. The display device C also includes a signal display device 12 that visually displays the identified signal, and a signal detection ringer 13 that emits an acoustic signal.

FIG. 4 shows a probe coil, and as shown in the figure, a divided current transformer is connected to the inner conductor 2a of the probe coil cable core wire 2 without contacting it from above the insulating outer cover 2b of the probe coil. It is of type.

When using the cable core wire detection device described above, as shown in FIG. A signal output terminal 8
and send out exploration signals. The current value of the exploration signal tends to change in level as it is affected by the length of the core wire 2, but the modulated exploration signal and the exploration signal amplified by the signal output amplifier 5 are returned. It is kept constant by being input to the differential amplifier 7 as a signal.

On the other hand, the outer sheath of the multi-core cable 1 is peeled off at the inspection point in the middle of the multi-core cable 1, the inner core wire 2 is taken out, the exploration coil 3 is attached from above the insulating outer sheath 2b, and the inner conductor 2a of the core wire 2 is Detect exploration signals by contactless bonding. This detected signal is amplified by a signal amplifier 9 and input to a discriminator 11.

As described above, a different core wire identification code is given to each of the plurality of core wires 2 by the modulator 4a to the transmitted exploration signal. For this reason, the exploration coil 3
The discriminator 11 can easily identify which signal output terminal 8 of the exploration signal transmitter A the core wire 2 whose signal has been detected is connected to.

The discrimination output from the discriminator 11 is output to a signal display device 12 and a signal detection ringer 13. Then, the number of the signal output terminal 8 to which the detected core wire 2 is connected is displayed on the signal display device 12, and the signal detection ringer 13 emits a predetermined sound so that the measuring person can sense the identification.

As described above, the cable core wire detection device according to the present invention can detect the probe signal current without contacting the inner conductor of the probe core wire, and therefore can be used in various fields. Examples are as follows.

(b) Core wire detection of multi-core cables (communication cables, control cables, etc.) (b) Grounding detection of dendritic electrical circuits (c) Wiring detection of congested electrical wiring circuits. Shown in Figure 5 A, B, and C.

In the case of Figure 5 A, the left and right sides of the cable are connected to electrical equipment, the exploration signal transmitter A is connected to the left end of the target core wire, the right end is short-circuited at 14, and the core wire is detected by the exploration signal detector B. Do some exploration. FIG. 5B shows an example of grounding probe of a dendritic circuit between electrical equipment 15, 15. Figure 5C shows an example used for congestion cable exploration.

Effects of the Invention As explained above, the cable core wire detection device according to the present invention sends out a low frequency probe signal by giving a different core wire identification code to each of the plurality of core wires connected to the signal output terminal, and detects the core wires. This is detected by a divided current-transforming probe coil that connects contactlessly with the internal conductor, and the core wire through which the detected probe signal flows is identified by a signal identifier using the core wire identification code given to the detected probe signal. This makes it possible to conduct continuity tests on the internal conductors of the core wires without having to reconnect the probe signal transmitter to multiple core wires one by one, or without cutting the core wires or pricking them with a needle. This has the remarkable effect of allowing live line work to be carried out while the cable equipment is in operation.

Further, in the present invention, the current value level of the exploration signal is made constant and outputted using a differential amplifier that receives the modulated exploration signal and the amplified exploration signal return signal, so that the core wire Another effect is that continuity tests can be performed without being affected by length.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing an embodiment of the cable core wire detection device according to the present invention, FIG. 2 is a block diagram showing the probe signal transmitter shown in FIG. 1, and FIG. 3 is a block diagram showing the probe signal transmitter shown in FIG. 1. A block diagram showing the detector and indicator, Figure 4 is an enlarged view of the exploration coil, Figure 5 A,
B and C are schematic diagrams showing examples of how the above device is used, respectively. A...Exploration signal transmitter, B...Exploration signal detector, C...Display device, 1...Multi-core cable, 2...
Core wire, 3...Exploration coil.

Claims (1)

[Scope of Claims] 1. A probe signal transmitter that connects to the core wire at one end of the multicore cable and sends a probe signal; A cable core wire detection device that detects a probe signal passing through the core wire by a contact-coupled probe coil, and detects a core wire at an intermediate position of a multicore cable, wherein the probe signal transmitter includes a plurality of probe signal transmitters. A low frequency oscillator is provided, and the output of the low frequency oscillator is provided with a different core wire identification code for each of the plurality of core wires connected to the signal output terminal. and a signal modulation controller that controls the output of the signal output amplifier to the signal output terminal in synchronization with the application of the core wire identification code, the exploration signal detector comprising: A cable characterized in that it is equipped with a divided current transformation type probe coil that connects without contact with the inner conductor of the core wire, and a signal identifier that identifies the core wire through which the detected probe signal flows based on the core wire identification code of the detected probe signal. Core wire exploration device. 2 The exploration signal transmitter is connected to a signal output amplifier that amplifies and outputs the modulated exploration signal, and between the modulator and the signal output amplifier, and is connected between the modulator and the signal output amplifier to amplify and output the modulated exploration signal. 2. The cable core wire detection device according to claim 1, further comprising a differential amplifier for inputting the feedback signal of the amplified probe signal and outputting the same current value level of the probe signal.