JPH1096785A - Conduit tube detecting method and device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reliably detect a position of a conduit tube in concrete by carrying an electric current to the conduit tube or an electric wire inside it, and detecting a magnetic field generated by current-carrying. SOLUTION: A conduit tube 6 is inserted between reinforcements 1 and 2, and an electric wire 8 is inserted into it, and a high frequency current is carried from an oscillator 9. A conduit tube detector 10 is arranged on a surface of concrete 5, and a line current magnetic field is detected by an air-core coil 11 in it, and its detecting output is sent to a signal component extractor 13 through an amplifier 12, and DC voltage in proportion to intensity of the line current magnetic field is outputted. Its output voltage is displayed by a voltmeter 14, and when it exceeds prescribed voltage, a yellow lamp 16 is lighted by a comparator 15, and when it becomes higher voltage, a red lamp 18 is lighted by a comparator 17. A red line 19 to show the direction of the conduit tube 6 is displayed in the direction orthogonal to the axis of the air-core coil 11 on a surface of the conduit tube detector 10, and the air-core coil 11 detects the conduit tube 6, and at azimuth time when a detecting magnetic field becomes maximum, the direction of the conduit tube 6 is displayed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conduit for accommodating a signal line for transmitting information important for business functions in a reinforcing bar or the like in concrete for maintaining the strength of a concrete building. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conduit detector for detecting only conduits and avoiding them so as to prevent the conduits from being accidentally destroyed during repair work.

[0002]

2. Description of the Related Art Extending the service life of existing buildings by repairing or renovating them increases the costs of dismantling and rebuilding,
At present, it is extremely difficult to process residual materials,
% Of buildings are being renovated without dismantling. At the time of renovation, the functions of the building are dramatically improved by adding a cooling / heating function, a telephone call, and a communication function. During such renovation work, it is essential to make holes in the concrete floor or wall, and when performing such work, cut off the conduit containing the communication lines, such as computers, and destroy the communication function. Has a very serious negative effect on society. In addition, at the time of construction, if the power line, lighting power line and other commercial lines are short-circuited by mistake, the main breaker will fall,
If the computer connected to it goes down or is in a room without windows, it will be dark. Therefore, it is desired to detect only the conduit so as not to destroy the conduit that is important for business functions, regardless of the reinforcing steel in the concrete for maintaining the strength of the building.

Conventionally, an X-ray system, a γ-ray system, an ultrasonic system, a radar system, a static magnetic field system, an induction magnetic field system and the like have been proposed for detecting a conduit tube.

However, each of these methods has its own drawbacks. In other words, the X-ray method uses X
If the x-ray film must be set and the location is outside a high-rise building, setting the x-ray film can be enormous. In the case of a plastic conduit tube, a clear image cannot be expected. Investigation over a large area is very expensive. The same applies to the γ-ray method. In the ultrasonic method, it is necessary to take measures to attenuate the ultrasonic wave, such as painting vaseline between the probe and the wall surface, and it is difficult to decode the waveform of the echo. The radar method also detects reinforcing bars for concrete reinforcement, and it is difficult to decipher the waveform of the echo. The static magnetic field method detects a reinforcing bar for concrete reinforcement similarly to the radar method, and is difficult to distinguish from a conduit. Also, if the conduit is non-metallic or non-ferromagnetic, it cannot be detected at all. The induction magnetic field method detects a reinforcing bar for concrete reinforcement and cannot detect only a conduit.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned drawbacks, without breaking existing concrete, and being easy to handle and excellent in portability. It is an object of the present invention to provide a conduit tube detecting device capable of reliably detecting a conduit tube. Furthermore, if the detection principle of the present invention is applied, a thickness of 15 to 20 c
m, not limited to concrete walls or floors,
It can also be used to detect highway supports up to 2 meters high and tension wires used in bridge girder.

[0006]

In order to solve the above-mentioned object, in a conduit tube detecting device according to the present invention, a conductive conduit tube is energized. In the case of a non-conductive conduit, an electric wire is passed through the conduit, and the electric wire is energized. The present invention is characterized in that a conduit is detected by detecting a line current magnetic field generated by energization. That is, the present invention provides a conduit tube detection method and apparatus which detect a magnetic field due to a line current instead of detecting the magnetization of a ferromagnetic material. Here, since concrete is non-magnetic, it has nothing to do with a conduit tube detector for detecting a line current magnetic field.

[0007] When the rebar is magnetized from the lateral direction by the line current magnetic field, the demagnetizing field coefficient is large, and the rebar is very slightly magnetized. Therefore, the magnetic field due to the line current magnetic field is overwhelmingly large, and the magnetic field due to the magnetization of the rebar is ignored. That is, no rebar is detected.

When the rebar is partially magnetized in the longitudinal direction, that is, in the length direction by the line current magnetic field, the demagnetizing factor is small and the rebar is magnetized, but its magnetic pole mainly occurs at the end of the rebar. Therefore, it is far from the detector and generates only a very small magnetic field from the rebar. Therefore, the magnetic field due to the line current magnetic field is overwhelmingly large, and the lengthwise magnetization of the rebar is ignored. That is, no rebar is detected.

In this way, even when sandwiched between ferromagnetic rebars, a conduit detection method and apparatus for detecting only conduits which cannot be considered by other means regardless of the upper and lower rebars at all. Could be provided. In the method of generating an induction current by applying a high-frequency magnetic field from the outside and detecting a conduit from the line current, a line current is also generated from a nearby reinforcing bar,
As with the radar system, it is difficult to distinguish from a conduit.

[0010] The conduit tube detecting device has the following basic structure.
Oscillator that passes a wire through a conduit or a conduit through a conduit current generator to generate a line current magnetic field by energizing the wire, and an air-core coil or fluxgate type that detects the line current magnetic field Consists of a magnetic field detector.

Since the line current magnetic field is generated concentrically from an energized electric wire or conduit, the magnetic field detector is opposed to the normal direction of the concentric circle.

When the conduit detector is moved parallel to the wall or floor and to the wall or floor, the line current magnetic field is maximized immediately above the energized conduit, thus locating the conduit. You can check.

The conduit detection device displays a yellow lamp when the conduit detection output reaches a predetermined fixed level, and displays a red lamp when it reaches the maximum level.

A sub-conduit detector is provided at a fixed distance to the left and right of the main conduit detector, and the angle of the sub-conduit detector is changed. From the distance from the main conduit detector, the depth of the conduit from the wall or floor can be known.

Further, when the auxiliary conduit detector is opposed to the main conduit detector at a fixed angle, and the detector is moved in parallel with the wall or the floor,
When the yellow lamp is turned on when the detection output of the sub conduit detector reaches a predetermined level, the electric wire is located just below the main conduit detector at the position where each lamp of the sub conduit detector is lit. The position of the tube.

When the main conduit detector is detecting a conduit, when it rotates on a plane parallel to a wall or a floor, and when the detected output reaches a maximum value, the direction of the conduit is confirmed. be able to.

The detector level may be notified by a buzzer sound.

When a wire was passed through a steel conduit and a line current was passed, the line current magnetic field was the same as when the conduit was energized. That is, there is no shielding effect by the steel conduit.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a structural view of a concrete floor detected by using the method and apparatus for detecting a conduit according to the present invention, wherein FIG. 1 (a) is a vertical sectional view, and FIG. Is a plan view. The arranged reinforcing bars 1 and 2 are supported by steel spacers 3 and 4, respectively, and are left in the concrete 5 after the concrete 5 is hardened. The electric conduit 6 may be installed in the middle of the reinforcing bars 1 and 2 in the arrangement, or may be installed on the reinforcing bar 2 like the electric conduit 7. In any state of the conduit, the conduit detecting device according to the present invention includes:
These conduits are surely detected.

FIG. 2 shows the configuration of an embodiment of a conduit tube detecting device. In the figure, reinforcing bars 1 and 2
In between, there is an electric conduit 6, an electric wire 8 is passed through the electric conduit 6, and a high-frequency current flows from an oscillator 9.
A conduit detector 10 is placed on the surface of the concrete 5, and the conduit detector 10 includes an air-core coil 11 for detecting a line current magnetic field. The detection output of the air-core coil 11 is connected to the amplifier 12. The amplifier 12 outputs a DC voltage proportional to the magnitude of the line current magnetic field detected by the conduit tube detector 10 by the signal component extractor 13. Its output voltage is
In addition to being displayed by the digital or analog voltmeter 14, the comparator 15 turns on the yellow lamp 16 when the voltage exceeds a predetermined voltage, and the comparator 17 turns on the red lamp 18
Lights up.

A red line 1 indicating the direction of the conduit in a direction perpendicular to the axis of the air-core coil 11 is provided on the surface of the conduit detector 10.
9 is displayed, and the direction of the conduit is displayed when the conduit detector 10 detects the conduit and has the azimuth at which the detected magnetic field is maximized.

When the conduit tube detector 10 is moved in parallel with the wall or floor surface and the conduit tube 6 is detected, when the conduit tube detector 6 detects something like the conduit tube 6, as shown in FIG. The vessel 10 is rotated, and the direction in which the voltage is maximized is searched. Immediately below that position is the position of the conduit 6, and the red line 19
Direction. Here, a fluxgate type detector is used as the detector 20, because the magnetic field received by the fluxgate type detector 20 in this direction becomes maximum.

The line current magnetic field H becomes smaller with distance from the line current I, and its magnitude can be calculated theoretically.
That is, the magnetic field H on a concentric circle with a radius r from the center of the wire
Is represented by the following equation. H = I / 2πr Therefore, if the magnitude of the flowing current is determined, the burying depth of the conduit can be known by measuring the maximum magnetic field at the measurement point. If the relationship between the magnitude of the line current and the generated magnetic field is input in advance to the calculator, the measured magnetic field can be displayed at the burial depth r (mm) of the conduit tube.

As another embodiment, when a wire current is applied to a steel material buried relatively deep from the surface such as a tension wire used in a bridge to detect the wire current, the detection accuracy is further increased. Next, a method of detecting the above will be described. In FIG. 4, auxiliary flux conduit type detectors 21 and 22 are prepared at a certain distance from the flux gate type main conduit detector 20-1. The angle of the flux gate type auxiliary conduit detectors 21 and 22 can be freely changed by pulse motors 23 and 24 having a speed reducer. When the main conduit detector 20-1 and the sub conduit detectors 21 and 22 each reach a certain detection level, the yellow lamps 25, 26 and 27 respectively light up. The auxiliary conduit detectors 21 and 22 are replaced with the main conduit detector 20-
When it is set at the same horizontal position as that of 1 and moves in parallel to the wall surface to be measured, a line current magnetic field from a tension wire or the like is detected. Further, the parallel movement of the wall surface is repeated to search for a position at which the detection output of the main conduit tube detector 20-1 is maximized. At that position, a pulse motor 2 with a speed reducer
The sub conduit detectors 21 and 22 are automatically rotated until the outputs of the sub conduit detectors 21 and 22 are maximized, and are automatically stopped at the maximum positions. The rotation angle is displayed on the angle indicators 29 and 30 of the auxiliary conduit detectors 21 and 22 of the display 28. Angle indicators 29, 3
When 0 is displayed at the same angle with different polarities, the position immediately below the main conduit tube detector 20-1 is the position of a tension wire or the like, and the direction is the direction indicated by the red line 19. The depth is calculated from the detected voltage of the main conduit tube detector 20-1 by the method already described. In addition, the depth of the tension wire and the like is calculated by a simple geometrical calculation from the display angles of the angle indicators 29 and 30 of the auxiliary conduit detectors 21 and 22 and the distance from the main conduit detector 20-1. I was able to know exactly.

As described above, if the present conduit tube detecting device is used, in conducting a preliminary inspection of a conduit in a large opening such as an opening of a duct of an air conditioner or an addition of an entrance / exit, an electric wire follows a line to be opened. It is an extremely simple and reliable conduit detector that requires only moving and manipulating the tube detector and does not require a survey of the entire surface.

The conduit is not always installed parallel or perpendicular to the wall or floor reinforcement, but may be installed diagonally. The direction of the conduit of the conduit is not required, and two detection coils 31 and 32 orthogonal to each other are prepared as shown in FIG. Detecting the presence or absence of a conduit by squaring the respective detection outputs of the detection coils 31 and 32 with a multiplier, adding the respective multiplier outputs with an adder, and displaying the total magnetic force on a display 33. Was completed.

FIG. 6 shows an example in which one of the commercial line terminal 34 and the live line 36 of the distribution board 35 which is already connected is used, and the output of the oscillator 9 is supplied through the capacitor 37 to the high-frequency current. An example is shown. Even when the live line was used, the conduit 6 could be detected in exactly the same way as the dedicated line.

[0028]

As described above, according to the present invention,
It is easy to handle and excellent in portability without breaking the wall surface, and can reliably detect only conduit.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a concrete wall surface according to the present invention.

FIG. 2 is an embodiment of a conduit tube detector.

FIG. 3 is an embodiment in which a conduit detector is used.

FIG. 4 is an example of detection of a steel material buried relatively deep.

FIG. 5 is another embodiment of the conduit tube detector.

FIG. 6 is an example of using a conduit tube detector using an existing line.

[Explanation of symbols]

 1, 2 Reinforcing bar 3, 4 Spacer 5 Concrete 6, 7 Conduit tube 8 Wire 9 Oscillator 10 Conduit tube detector 11 Coil 12 Amplifier 13 Signal component extractor 14 Voltmeter 15, 17 Comparator 16, 18 Lamp 19 Red line 20 Flux gate Type detector 20-1 Main conduit detector 21, 22 Sub conduit detector 23, 24 Pulse motor 28 Display 29, 30 Angle display 31, 32 Coil 33 Display 34 Commercial terminal 35 Distribution board 36 Live 37 Capacitor

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Kunihiko Yoshimi 2-29-29 Heian-cho, Tsurumi-ku, Yokohama-shi, Kanagawa 1 Inside the Keisan Seisakusho Co., Ltd. (72) Inventor Yuji Nozawa 2, Heian-cho, Tsurumi-ku, Yokohama, Kanagawa No. 29-1 Kyosan Seisakusho Co., Ltd. (72) Inventor Masanori Tsutsui 2-3-3 Kandaji-cho, Chiyoda-ku, Tokyo Obayashi Corporation Tokyo head office (72) Inventor Yoshitoshi Watanabe 2, Kandaji-cho, Chiyoda-ku, Tokyo 3-chome Obayashi Corporation Tokyo head office

Claims (5)

[Claims] 1. A conduit tube detecting method for energizing a conduit tube or an electric wire passing through the conduit tube, detecting a magnetic field generated by the conduction, and thereby detecting a position of the conduit tube. 2. A conduit detector for detecting a position of a conduit, comprising: means for supplying current to a conduit or an electric wire passing through the conduit; and conduit detector for detecting a magnetic field generated by the supply of electric current. apparatus. 3. The conduit tube detecting device according to claim 2, wherein a high-frequency current is supplied to a live wire or the like already passed through said conducting means via a capacitor. 4. A main conduit detector for detecting a magnetic field obtained by energizing a conduit or an electric wire passing therethrough, and at least one main conduit detector located at a predetermined distance from the main conduit detector. A detector comprising a sub conduit detector,
A conduit detector for comparing the detection output of the main conduit detector and the output of the sub conduit detector to confirm the position of the conduit. 5. The apparatus according to claim 5, further comprising: means for changing an angle of the auxiliary conduit detector with respect to the conduit, wherein a depth of the conduit is detected from a change in detection output of the auxiliary conduit detector due to the change in the angle. 5. The conduit detecting device according to claim 4, wherein: