JP4351985B2 - Underground pipe exploration equipment - Google Patents

Description

  The present invention relates to a buried pipe exploration device for exploring an exploration target pipe connected to a buried piping path.

  As a method of exploring the exploration target pipe, an alternating exploration current is supplied to each exposed portion of the two supply pipes that branch off from the buried pipeline, and the magnetic field generated from the exploration target pipe by this exploration current is brought to the ground. There is a method of detecting with an installed detector (hereinafter referred to as “double one-point method”) (see Patent Document 1). In this detection method, as shown in FIG. 6, the connection line of the transmitter 80 is exposed from two supply pipes K that branch from a buried pipe line (main pipe in the literature) H that is buried in the ground and extend to the ground. Connected to the parts Kr and Kr ′ and the ground electrode Gr, the alternating exploration current supplied from the transmitter 80 to each of the two exposed parts Kr and Kr ′ is changed relative to one to the other and buried The point Q at which the current value is zero on the pipe line H is brought close to the branch position P where the search target pipe M (branch pipe in the literature) to be searched branches from the buried pipe line H.

  As a result, the magnitude of the current flowing through the buried piping H from the point Q to the branch position P in the buried piping H can be reduced, and the magnitude of the current flowing through the exploration target pipe M can be increased. For this reason, the magnetic field distribution generated from the position in the vicinity of the point Q increases as the magnetic field corresponding to the point Q becomes zero and the magnetic field corresponding to the buried piping H on the branching position P side from the point Q increases from the point Q. The magnetic field corresponding to the exploration target tube M further increases to show a peak value. For this reason, when the magnetic field is detected by the detector 81 installed on the ground, the existence of the exploration target pipe M can be confirmed from the peak value of the magnetic field.

JP 63-300990 A

  By the way, if the buried pipeline connected to the exploration target pipe is in a non-conducting state, the point Q where the current value becomes zero cannot be created on the buried pipeline H, and the current value flowing through the exploration target pipe becomes the peak value. However, if the continuity of the buried pipe line can be confirmed, the double-point method will show the pipe to be searched as a peak value of a large current value. The exploration of the exploration target pipe can be facilitated. For this reason, in order to facilitate the exploration of the exploration target pipe, a current having a large current value is supplied to the supply pipe. Here, the current supplied to the supply pipe when the buried pipeline is in the conductive state returns to the ground electrode through the buried pipeline and the exploration target pipe, while the buried pipeline is in the non-conductive state. The current supplied to the supply pipe leaks from the buried piping line and returns to the ground electrode through the ground. And the magnitude | size of the electric current which returns to an earth electrode when a buried piping path is a non-conduction state hardly changes with it when a buried piping path is a conduction state. For this reason, in the conventional buried pipe exploration apparatus, even when the exploration target pipe cannot be explored by the double one-point method, the exploration target pipe is explored, and an exploration result with low apparent reliability has been obtained. That is, the conventional buried pipe exploration device has a problem that the reliability of the exploration result of the exploration target pipe may be lowered.

  This invention is made | formed in view of such a problem, and it aims at providing the buried pipe | tube search apparatus with high reliability of the exploration result of the investigation object pipe | tube connected to a buried piping path.

In order to solve such a problem, the present invention supplies the signal current from the transmitter to each exposed portion of the two supply pipes that branch off from the buried pipeline so that the magnitude can be adjusted. In the buried pipe exploration device for exploring the inspection target pipe by detecting a magnetic field generated by a current flowing in the inspection target pipe connected to the pipe line, the transmitter is connected to one exposed portion of the two supply pipes. A first current adjusting means that can be connected between a terminal to be connected and a ground terminal and supplies a signal current to the one exposed portion so as to be adjustable in magnitude, and to the other exposed portion of the two supply pipes A second current adjusting means that is connectable between a terminal to be connected and a ground terminal and supplies a signal current to the other exposed portion so as to be adjustable in magnitude; and one exposed portion of the two supply tubes A signal current is supplied from a connected terminal to A buried pipe line continuity inspection means for inspecting the conduction state of the buried pipe line from the magnitude of the current flowing through the pipe line and returning to the terminal connected to the other exposed portion of the two supply pipes, The pipe line continuity inspection means connects the first current adjusting means to a terminal connected to one exposed part of the two supply pipes and a terminal connected to the other exposed part of the two supply pipes A first state of connecting the second current adjusting means, a terminal connected to one exposed part of the two supply pipes, and a terminal connected to the other exposed part of the two supply pipes A switch for switching between a second state in which a power supply for energization inspection is connected is provided.

  According to this invention, by providing the buried pipe line continuity inspection means for inspecting the continuity state of the buried pipe line, before conducting the exploration of the exploration target pipe, the conduction state of the buried pipe line connected to the exploration target pipe is inspected. be able to. For this reason, only the exploration target pipe connected to the buried piping path in the conductive state can be the exploration target, and the reliability of the exploration result of the exploration target pipe can be improved.

Further, according to the present invention, the buried pipe line continuity inspection means includes a first current adjusting means and a second current adjusting means, and the signal current supplied by any one of these is supplied to one exposed portion, whereby the exposed portion is The magnitude of the supplied signal current can be arbitrarily adjusted, and this adjusted signal current can be supplied to the buried pipeline. For this reason, it is possible to easily ensure a signal current necessary for conducting a continuity inspection of the buried piping path according to the length of the buried piping path.

  According to the present invention, the buried pipe line continuity inspection means includes a power source for supplying a signal current to one of the exposed portions.

  According to this invention, the power supply for supplying a signal current to one exposed part (for example, the power supply for continuity test 27 in the embodiment) is provided in the buried pipe line continuity test means, and this power supply is subjected to the continuity test. The operability of the continuity test can be improved.

  Further, the present invention is characterized in that the signal current supplied to the one exposed portion by the buried pipe line continuity inspection means is an alternating current.

  According to the present invention, by changing the signal current supplied to one of the exposed portions to an alternating current, the influence of stray current and polarization generated in the insulating film coated on the surface of the piping on the current flowing through the buried piping is eliminated. It is possible to improve the accuracy of the determination as to whether or not the buried pipeline is in a conductive state.

  Further, according to the present invention, the buried pipe line continuity inspection means supplies an AC signal current supplied to one of the exposed portions so that the frequency can be adjusted.

  According to this invention, by enabling adjustment of the frequency of the AC signal current supplied to one exposed part, when the pipe in the middle of the buried pipe line extends in parallel with the other system pipe, If the length of the pipe extending in parallel is long, the contact resistance between the pipe and the soil increases, and the capacitance between the pipe extending in parallel and the soil is reduced with respect to the flow of alternating current. Although it becomes dominant, if the frequency of the signal current is adjusted to be small, the current flowing through the buried pipe line will flow through the soil and return to the buried pipe exploration device, thereby reducing the impedance. Can do. For this reason, it can be judged clearly that this buried piping is in a non-conductive state.

  Furthermore, the present invention is characterized in that the buried pipe line continuity inspection means is provided with notification means for notifying that the buried pipe line is in a conductive state when the magnitude of the signal current flowing through the buried pipe line exceeds a predetermined value. .

  According to this invention, when the magnitude of the signal current flowing through the buried pipeline exceeds a predetermined value, the notification means informs that the buried pipeline is in a conductive state, thereby confirming that the buried pipeline is in a conductive state. Can be easily informed.

  According to the buried pipe exploration device according to the present invention, a signal current is supplied to one of the exposed portions of each of the two supply pipes that branch off from the buried pipeline to extend the buried pipeline. Improving the reliability of the exploration result of the pipe to be probed connected to the buried pipe line pipe by providing a buried pipe line continuity inspection means that inspects the continuity state of the buried pipe line from the magnitude of the current flowing back to the other exposed part. Can be made.

  A preferred embodiment of the buried pipe exploration device according to the present invention will be described below with reference to FIGS. In the buried pipe exploration device 1 of the present invention, the buried pipe H is connected to the buried pipe H, and the buried pipe H is in a conductive state as a premise for capturing a magnetic field generated from the exploration current flowing through the exploration target pipe. It has a function that can determine whether or not.

  As shown in FIG. 1, the buried pipe exploration device 1 detects a magnetic field generated from a transmission device 10 that supplies an AC signal current to the buried piping line H and a current flowing through the investigation target pipe M that is connected to the buried piping line H. The transmitter 10 has a function that enables the transmitting device 10 to determine whether or not the buried piping line H is in a conductive state. For this reason, since the magnetic field detection device 70 is a non-essential part of the present invention, only the outline of the magnetic field detection device 70 will be described. That is, the magnetic field detection device 70 includes a detector 71 that is installed on the ground and detects a magnetic field, and a receiver 73 that includes a meter that operates according to the magnetic field detected by the detector 71.

  The transmitting device 10 searches the pipe M to be searched by supplying a search current whose size is adjusted to the exposed portions Kr and Kr ′ of the two supply pipes K that branch off from the buried pipe H. At the same time, it has a function of inspecting the conduction state of the buried piping line H described above. As shown in FIG. 2, the transmission device 10 includes an oscillation circuit 11 that generates an alternating signal current, and a first current adjustment output circuit that adjusts and outputs the signal current output from the oscillation circuit 11 to a desired magnitude. 13 and the second current adjustment output circuit 14 and one exposed portion (Kr in FIG. 2) of the two exposed portions Kr and Kr ′ to supply a signal current to flow through the buried piping H and the other exposed portion. (Kr ′ in FIG. 2) The continuity inspection circuit 20 for inspecting the continuity state of the buried pipeline H from the magnitude of the return current, the meter 60 for displaying the continuity state of the buried pipeline H, the meter 60, and each circuit And a power supply circuit 65 for supplying electric power.

  The first current adjustment output circuit 13 and the second current adjustment output circuit 14 are configured to be manually adjustable, and adjust the first current adjustment output circuit 13 and the second current adjustment output circuit 14 based on the display of the meter 60. Is also possible. For this reason, it is possible to make a state where no exploration current is output from both the first current adjustment output circuit 13 and the second current adjustment output circuit 14.

  As shown in FIG. 3, the continuity test circuit 20 includes an output switch 21, an input switch 24, and a continuity test power supply 27. One side terminal 21c of the output switch 21 is electrically connected to the output terminal 66, and the first terminal 21b of the other side terminal of the output switch 21 is electrically connected to the plus side of the first current adjustment output circuit 13 for output. The second terminal 21 a of the other terminal of the switch 21 is electrically connected to the continuity test power supply 27. The continuity test power supply 27 is electrically connected to the meter 60, and the meter 60 is electrically connected to the second terminal 24 a of the other terminal of the input switch 24. One terminal 24 c of the input switch 24 is electrically connected to the input terminal 67, and the first terminal 24 b of the other terminal of the input switch 24 is electrically connected to the plus side of the second current adjustment output circuit 14. .

  For this reason, when the switch part 22 of the output switch 21 is connected to the second terminal 21a and the switch part 25 of the input switch 24 is connected to the second terminal 24a, the signal current supplied from the continuity test power supply 27 is 21 → output terminal 66 → exposed portion Kr on one side → buried piping H → exposed portion Kr ′ on the other side → input terminal 67 → input switch 24 → meter 60 to form a closed circuit.

  The output switch 21 and the input switch 24 operate in conjunction with adjustment of the search current output from both the first current adjustment output circuit 13 and the second current adjustment output circuit 14 to be zero. These switches 21 and 24 may be operated in conjunction with a separately provided continuity check switch (not shown) that is turned on or off.

  Thus, by providing the continuity test circuit 20 with the output switch 21, the input switch 24, and the continuity test power supply 27, it is possible to dedicate this power supply when conducting the continuity test. 13 and the output adjustment of the second current adjustment output circuit 14 become unnecessary, and the workability of the continuity test can be improved. The continuity test power supply 27 is set so as to reduce the frequency of the AC signal current supplied to one of the exposed portions Kr (for example, about 1 KHz). This is because, when a coating film is applied to the buried piping line H and the pipe in the middle of the buried piping line H extends in parallel with the pipes of other systems, if the frequency of the signal current is reduced, it is parallel. The influence of the electrostatic capacity between the extending pipe and the soil is reduced, and the magnitude of the current flowing from the pipe through the soil and returning to the buried pipe exploration device 1 can be reduced. As a result, the buried pipe This is because the accuracy of determining whether or not the path H is in a conductive state can be improved.

  The continuity test circuit 20 detects the current waveform having the same phase as the phase of the signal current supplied to one of the exposed portions Kr out of the current returned to the other exposed portion Kr ′. When the meter 60 is operated according to the magnitude of the current, the current that has actually flowed through the buried piping line H can be displayed on the meter 60, thereby enabling more accurate determination of the conduction state of the buried piping line H. be able to. Further, the transmitting device 10 is provided with a ground terminal 68 for grounding the pair of current adjustment output circuits 13 and 14 and the continuity test circuit 20. For this reason, the reference potential of the signal current and the return current output from these output circuits 13 and 14 becomes clear, and the magnitude of the return current can be accurately determined.

  Next, a method for inspecting the conduction state of the buried piping line H by the transmitting device 10 of the buried pipe searching device 1 configured as described above will be described. First, as shown in FIG. 1, one side of the cable C is connected to the output terminal 66 of the transmitting device 10, and the other side of the cable C is branched from the buried piping line H to one of the two supply pipes K. Connect to the exposed portion Kr. Further, one side of the cable C ′ is connected to the input terminal 67 of the transmitting device 10, and the other side of the cable C ′ is connected to the other exposed portion Kr ′. Further, the ground cable Cs connected to the ground terminal 68 is grounded.

  And as shown in FIG. 2, the power supply circuit 65 of the transmitter 10 is driven, and each circuit is operated. Then, the first current adjustment output circuit 13 and the second current adjustment output circuit 14 are adjusted so that the magnitude of the signal current output from these output circuits becomes zero. When the first current adjustment output circuit 13 and the second current adjustment output circuit 14 are adjusted so that the magnitude of the signal current becomes zero, the output switch 21 and the input switch 24 are interlocked as shown in FIG. Then, a signal current is supplied from the power supply 27 for continuity testing to one exposed portion Kr, and this signal current is applied to the exposed portion Kr on one side → the buried piping line H → the exposed portion Kr ′ on the other side. The input terminal 67 → input switch 24 → meter 60 flows to form a closed circuit.

  Here, if the current value of the returned current is within a predetermined value range, the continuity test circuit 20 moves the pointer of the meter 60 into a region indicating the conductive state of the buried piping line H, and the current value is predetermined. If it is out of the range of the value, the pointer of the meter 60 is moved into a region showing a non-conduction state.

  As a result, when the indicator of the meter 60 indicates that the buried piping H is in a non-conducting state, the operator can determine that the exploration target pipe M connected to the buried piping H cannot be searched. Indicates that the exploration pipe M can be searched. As a result, only the exploration target pipe M connected to the buried piping path H in the conductive state can be the exploration target. For this reason, as shown in FIG. 1, the alternating exploration current supplied from the transmitter 10 to each of the two exposed portions Kr and Kr ′ is changed relative to one to the other, and the embedded piping H When the magnetic field is detected by the detector 70 installed on the ground, the point Q where the current value becomes zero is brought close to the branch position P where the exploration target pipe M branches from the buried pipe H, and the point Q is detected. In addition, the branch position P and the position of the search target pipe M can be accurately searched, and as a result, the search target pipe M can be reliably searched.

  As shown in FIG. 4, the meter 60 may be replaced with at least one of a current discriminating circuit 40 and a lamp 41 and a buzzer 43 connected thereto. The current discriminating circuit 40 operates so as to turn on or blink the lamp 41 or sound the buzzer 43 when the magnitude of the return current flowing back through the buried pipe H shown in FIG. 3 exceeds a predetermined value. . Thus, by providing the lamp 41 and the buzzer 43, it is easy to notify the conduction state of the buried piping line H, and the operator can easily recognize that the buried piping line H is in the conduction state. . The lamp 41 may be turned off when the buried piping line H is in a conductive state.

  Further, as shown in FIG. 5, when the continuity inspection circuit 20 performs the continuity inspection of the buried piping line H, the input terminal 67 is on the negative side of the first current adjustment output circuit 13 and the second current adjustment output circuit 14. It may be configured to be electrically connected. The continuity test circuit 20 includes the current discriminating circuit 40, the input switch 24, and the ground changeover switch 30, and the signal current is supplied from the first current adjustment output circuit 13.

  The current discriminating circuit 40 is electrically connected between the plus side of the first current adjustment output circuit 13 and the output terminal 66, and at least one of the lamp 41 and the buzzer 43 is connected. One side terminal 24c of the input switch 24 is electrically connected to the input terminal 67, and the first terminal 24b of the other side terminal of the input switch 24 is electrically connected to the plus side of the second current adjustment output circuit 14 for input. The second terminal 24 a of the other side terminal of the switch 24 is electrically connected to the second terminal 30 a of the one side terminal of the ground changeover switch 30. Further, the first terminal 30 b on one side of the ground changeover switch 30 is electrically connected to the ground terminal 68, and the other side terminal 30 c of the ground changeover switch 30 is electrically connected to the negative side of the second current adjustment output circuit 14. Has been. For this reason, when the switch section 25 of the input switch 24 is connected to the second terminal 24a and the switch section 31 of the ground changeover switch 30 is connected to the second terminal 30c, the signal current output from the first current adjustment output circuit 13 is The current discriminating circuit 40 → the output terminal 66 → the one exposed portion Kr → the buried piping H → the other exposed portion Kr ′ → the input terminal 67 → the input switch 24 and the ground switch 30 → 13 is returned to form a closed circuit path. The signal current output from the first current adjustment output circuit 13 is set in advance to a small frequency in order to reduce the influence of the electrostatic capacitance described above.

  When the continuity inspection circuit 20 is configured in this way, when the buried piping line H is in a conductive state, the electrical resistance of the buried piping line H is small and the magnitude of the signal current flowing into the buried piping line H from the current discriminating circuit 40 is large. Since the height does not become small in the process of flowing through the buried pipeline H, it is possible to determine the magnitude of the current flowing through the buried pipeline H only by monitoring the magnitude of the exploration current flowing through the current discrimination circuit 40. As a result, the configuration of the continuity test circuit 20 can be simplified.

It is the schematic block diagram which showed the usage example of the buried pipe | tube search apparatus concerning one embodiment of this invention. The block diagram of the transmitter of this buried pipe exploration device is shown. The block diagram of the continuity test circuit provided in the transmitter is shown. It is the block diagram which showed the current discrimination circuit etc. which are connected to a continuity test circuit. The block diagram of the other continuity test circuit provided in the transmitter is shown. It is the schematic block diagram which showed the usage example of the conventional buried pipe | tube search apparatus.

Explanation of symbols

1 Buried pipe exploration device 10 Transmitting device (transmitter)
13 First current adjustment output circuit (first current adjustment means)
14 Second current adjustment output circuit (second current adjustment means)
20 Continuity inspection circuit (Built-in pipe line continuity inspection means)
27 Power supply for continuity test (power supply)
41 Lamp (notification means)
43 Buzzer (notification means)
H buried pipe K supply pipe Kr, Kr 'exposed part M exploration target pipe

Claims (5)

A magnetic field generated by supplying a signal current from the transmitter to each exposed portion of the two supply pipes branched and extending from the buried piping path so that the magnitude of the signal current can be adjusted, and flowing through the inspection target pipe connected to the buried piping path. In the buried pipe exploration device for exploring the inspection target pipe by detecting
The transmitter is
A first current adjusting means connectable between a terminal connected to one exposed portion of the two supply pipes and a ground terminal, and supplying a signal current to the one exposed portion so as to be adjustable in magnitude;
A second current adjusting means connectable between a terminal connected to the other exposed portion of the two supply pipes and a ground terminal, and supplying a signal current to the other exposed portion so as to be adjustable in magnitude;
A signal current is supplied from a terminal connected to one exposed portion of the two supply pipes, flows through the buried piping path, and returns to a terminal connected to the other exposed portion of the two supply pipes. An embedded pipe line conduction inspection means for inspecting the conduction state of the buried pipe line from the size,
The buried pipeline continuity inspection means connects the first current adjusting means to a terminal connected to one exposed portion of the two supply pipes and is connected to the other exposed portion of the two supply pipes. A first state in which the second current adjusting means is connected to a terminal, a terminal connected to one exposed portion of the two supply pipes, and a second exposed portion of the two supply pipes. A buried pipe exploration device comprising a switch for switching between a second state in which a power supply for energization inspection is connected to a terminal. The buried pipe exploration device according to claim 1, wherein the buried pipe line continuity inspection means includes a power source that supplies the signal current to the one exposed portion . 3. The buried pipe exploration device according to claim 1, wherein the signal current supplied to the one exposed portion by the buried pipe line energization inspection means is an alternating current . 4. The buried pipe exploration device according to claim 3, wherein the buried pipe line energization inspection means supplies an AC signal current supplied to the one exposed portion so that the frequency can be adjusted . The embedded pipe line continuity inspection means is provided with notification means for notifying that the buried pipe line is in a conductive state when the magnitude of a signal current flowing through the buried pipe line exceeds a predetermined value. The buried pipe exploration device according to any one of 1 to 4 .

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