JP3603973B2 - Damage inspection method for flexible gas pipes in wall and floor construction - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for inspecting a flexible gas pipe for damage caused by a nail or the like in wall and floor construction.
[0002]
[Prior art]
When a sharp pointed member such as a nail is hit in the construction of a wall or a floor, the nail may pierce a flexible gas pipe installed inside the wall or the floor, thereby opening a hole.
[0003]
Conventional inspection methods for detecting such damage to flexible gas pipes after construction include: a. A method in which a gas is passed through a flexible gas pipe, and a leaked gas is detected by an operator by odor or detected by a gas detection device; b. There is a method of inserting a fiber camera into a flexible gas pipe for confirmation.
[0004]
[Problems to be solved by the invention]
The method of detecting damage by leaking gas as in the method (a) requires time and labor, and cannot perform reliable detection. Even if a gas leak can be detected, it is difficult to pinpoint the location of the damage, and the wall or floor must be removed to finally confirm the damage.
In the case where the camera is inserted as in the method b, the distance that can be inspected is limited, and the configuration of the piping system is also limited.
An object of the present invention is to solve such a problem.
[0005]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, first, in the present invention, a flexible gas pipe installed inside a wall or a floor is radiated with an electromagnetic wave by an antenna of a transmission device attached to a proper position on the extension of the flexible gas pipe, and the inside of the flexible gas pipe is We propose to detect the damage by leaking electromagnetic waves from the flexible gas pipe by directing the antenna of the receiving device to the nail hit on the wall or the floor, and transmitting the electromagnetic waves.
[0006]
Next, in the present invention, a flexible gas pipe installed inside a wall or floor is radiated by an antenna of a transmitting device attached to an appropriate position on the extension of the flexible gas pipe to propagate electromagnetic waves in the flexible gas pipe, It is proposed to detect the electromagnetic wave by contacting the probe of the receiving device with the nail hit on the floor and to detect the damage by the electromagnetic wave leaked from the flexible gas pipe.
[0007]
Further, according to the present invention, the flexible gas pipe installed inside the wall or the floor is radiated by the antenna of the transmitting device attached at an appropriate position on the extension thereof to radiate electromagnetic waves to propagate through the flexible gas pipe, Aiming at the antenna of the receiving device at the nail that was struck, the electromagnetic wave is searched for, and when the electromagnetic wave is detected by the receiving device, the probe is brought into contact with the nail in the direction of the antenna to search for the electromagnetic wave, and the electromagnetic wave is detected. It is proposed to detect damage by leakage electromagnetic waves.
[0008]
Further, according to the present invention, the antenna of the receiving device is mounted at an appropriate position on the extension of the flexible gas pipe installed inside the wall or the floor, and the antenna of the transmitting device radiates electromagnetic waves toward the nail struck on the wall or the floor. At this time, it is proposed to monitor an electromagnetic wave propagating in the flexible gas pipe by a receiving device, and to detect damage by an electromagnetic wave incident on the flexible gas pipe from outside.
[0009]
Further, the present invention proposes to change the electromagnetic wave radiated by the transmission device with time in the above configuration.
[0010]
Further, the present invention proposes modulating an electromagnetic wave radiated by the transmitting device with a desired signal in the above configuration.
[0011]
Further, in the present invention, in the above configuration, the emission of the electromagnetic wave by the transmitting device is turned on and off, and the detection of the electromagnetic wave by the receiving device is performed at both the ON time and the OFF time, and the reception signal at the OFF time is changed to the ON time It is proposed to identify the electromagnetic waves from the transmitting device in comparison with the received signal.
[0012]
Further, according to the present invention, in the above configuration, the antenna is formed inside the plug that closes the test hole of the tee installed on the extension of the flexible gas pipe, and the antenna is positioned inside the tee with the plug attached. Suggest.
[0013]
Further, according to the present invention, in the above configuration, an antenna is formed inside a plug that can be screwed into a thread portion of a socket for a flexible gas pipe installed on an extension of the flexible gas pipe, and the antenna is mounted in a state where the plug is attached. It is proposed to place the in the tee.
[0014]
In the above configuration, the metal gas pipe including the flexible gas pipe can propagate electromagnetic waves in the same manner as the circular waveguide. Then, the electromagnetic wave can be radiated and propagated from an antenna of the transmitting device mounted at an appropriate position on the extension of the flexible gas pipe.
[0015]
The nail is pierced into the flexible gas pipe, and the tip penetrates through the metal pipe main body from the outer resin coating to the inside, and the resin coating is interposed between the nail and the hole opened in the pipe main body. In such a state, the nail acts as an antenna for the electromagnetic wave propagating in the flexible gas pipe, and the electromagnetic wave leaks from this portion. Therefore, by detecting the electromagnetic wave leaking from the flexible gas pipe in this way, it is possible to detect damage to the flexible gas pipe due to the nail.
[0016]
Leakage electromagnetic waves can be detected in a relatively wide range with an antenna, and can be detected for each nail with a probe. Exploration of leaking electromagnetic waves can be performed by only one of them, but in addition, first, an antenna is searched for electromagnetic waves in a relatively wide range, and when leaking electromagnetic waves are detected, A probe can be used to search for each nail within the search range.In this case, the search using the antenna narrows the search range using the probe to identify the nail that damaged the flexible gas pipe. It can be carried out.
[0017]
On the other hand, since the nail stuck in the flexible gas pipe acts as an antenna as described above, when an electromagnetic wave is radiated to the nail portion from the outside of the flexible gas pipe, the electromagnetic wave enters the flexible gas pipe and propagates. . Therefore, damage to the flexible gas pipe due to nails can also be detected by detecting the electromagnetic wave that has entered the flexible gas pipe from the outside in this way.
[0018]
Assuming that the frequency of the electromagnetic wave is changed over time, at a certain point in time, at a certain frequency, even if an electromagnetic field distribution that makes it difficult for the nail to leak from the damaged part and thus makes it difficult to detect the damaged part occurs, At a different frequency at the point of time, the electromagnetic field distribution changes, and the electromagnetic wave leaks from the damaged part, so that the damaged part can be detected.
[0019]
If the electromagnetic wave is modulated by a desired signal such as voice or image, it becomes easy to identify whether the electromagnetic wave received by the receiving device is transmitted from the transmitting device or is noise.
[0020]
Assuming that the transmission of the electromagnetic wave by the transmitting device is turned on and off, the detection of the electromagnetic wave by the receiving device is performed at both the ON time and the OFF time, and the received signal at the OFF time is compared with the received signal at the ON time. Electromagnetic waves from the transmitting device that are received only at the time of ON can be distinguished from noise that is received at any time.
[0021]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, embodiments of the present invention will be described with reference to the accompanying drawings.
FIG. 1 schematically shows the configuration and operation of the first embodiment of the method of the present invention. Reference numeral 1 denotes a flexible gas pipe installed in a space between the outer wall 3 and the inner wall 4 of the house 2 or the like. The flexible gas pipe 1 is, for example, a metal flexible pipe having a resin coating on the outside. is there.
[0022]
FIG. 3 specifically shows a configuration example on the upstream side of the flexible gas pipe 1 schematically shown in FIG. 1. In this example, the flexible gas pipe 1 is viewed from the inside of a house 2 or the like. A tee 6 called a test hole is connected to the upstream extension via a single screw socket 5, a steel gas pipe 7 is connected upstream of the tee 6, and a gas meter is connected upstream of the tee 6. 8 are installed.
[0023]
Returning to FIG. 1 again, when the flexible gas pipe 1 hits the nail 9 in the construction of the inner wall 4 or the like, if the nail 9 is accidentally aligned, the sharp tip of the nail 9 may be stuck. There is something. Therefore, the following damage inspection will be performed after the construction.
[0024]
In the damage inspection, first, the antenna 11 of the transmission device 10 is attached to an appropriate position on the extension of the flexible gas pipe 1. In the example of FIG. 1, the antenna 11 is attached to a tee 6 provided on a steel gas pipe 7 on the extension of the flexible gas pipe 1, and this tee 6 is also shown in FIG. . That is, the antenna 11 of this example is configured inside the plug 13 that closes the branch port 12 of the tee 6.
[0025]
FIG. 4 is an enlarged view showing the vicinity of the mounting position of the antenna 11, and the same reference numerals are given to the elements corresponding to the elements in FIG. First, the plug 13 is formed in a cylindrical shape, and a male screw portion 14b screwed to the female screw portion 14a of the branch port 12 is formed on the outside, and a female screw portion 16a screwed to the male screw portion 16b of the cylindrical lock nut 15 is formed inside. Is formed. The end of the coaxial cable 17 is inserted through the lock nut 15, the center lead 18 is projected, the braid of the shield wire 19 is expanded along the clamp 20, and a washer 21 and a gasket 22 are interposed at the end of the lock nut 15. Then, by tightening the lock nut 15 by screwing, the expanded shield wire 19 is pressed against the inner wall of the plug 13 to be in an attached state. On the other hand, a linear probe 23 is joined to the distal end side of the center lead 18, and the probe 23 is supported at the center position of the plug 13 by an insulator 24. On the other hand, a flange 25 is formed on the outer end of the plug 13, and an O-ring shaped radio wave shielding material 26 can be mounted between the flange 25 and the end of the branch port 12.
[0026]
In the above configuration, when an electromagnetic wave is supplied from the transmitting device 10 through the coaxial cable 17, an electromagnetic wave in a mode corresponding to the electric field generated by the probe 23 is excited in the tee 6, and the steel gas pipe 7 has the same structure as a circular waveguide. Electromagnetic waves can be propagated in various modes. In the case of figure, the steel gas pipe 7 propagates formed electromagnetic field modes TM _01.
[0027]
The electromagnetic wave excited in the tee 6 in this way propagates from the tee 6 to the flexible gas pipe 1 through the steel gas pipe 7. In the state where the electromagnetic wave is propagated to the flexible gas pipe 1, the electromagnetic wave is searched by directing the antenna 28 of the receiving device 27 toward the nail 9 hit on the inner wall 4.
[0028]
A nail 9 is pierced into the flexible gas pipe 1 and its tip penetrates through the metal pipe main body from the outer resin coating to reach the inside, and a resin coating is interposed between the nail 9 and the hole opened in the pipe main body. In such a state, the nail 9 acts as an antenna for the electromagnetic wave propagating in the flexible gas pipe 1, and the electromagnetic wave leaks from the nail 9.
[0029]
Therefore, by exploring and receiving electromagnetic waves leaking from the nail 9 while appropriately moving the antenna 28 of the receiving device 27 or changing the directional direction, it is possible to detect damage to the flexible gas pipe 1 due to the nail 9. Can be.
[0030]
In the above-described configuration in which the antenna 11 of the transmitting device 10 is attached to the tee 6, an antenna can be formed by projecting a loop (not shown) into the tee 6 instead of the plug 13. In addition to the tee, the antenna 11 of the transmitting device 10 is, for example, by removing the single-screw socket 5 in the above-described configuration of FIG. 3 and screwing a plug provided with a probe or the like here similarly to the configuration of FIG. For example, the antenna can be configured at an appropriate location with an appropriate configuration.
[0031]
FIG. 2 shows that the electromagnetic wave leaking from the nail 9 is detected by a probe 29 connected to the receiving device 27 instead of the antenna 28 of the receiving device 27. That is, the leaked electromagnetic wave can be detected in a relatively wide range by the antenna 28, while the probe 29 can be detected for each nail 9 by the probe 29. The search for the electromagnetic wave leaking from the nail 9 can be performed using only one of the antenna 28 and the probe 29, but it can also be performed in combination.
[0032]
For example, when an electromagnetic wave is detected in a relatively wide range by the antenna 28 and a leaking electromagnetic wave is detected, the probe 29 performs a search for each nail 9 within the search range by the antenna 28. According to such a method, the search range to be performed by the probe 29 can be narrowed by the search using the antenna 28, and the nail 9 that has damaged the flexible gas pipe 1 can be efficiently specified.
[0033]
As described above, the nail 9 inserted into the flexible gas pipe 1 functions as an antenna. Therefore, when an electromagnetic wave is radiated from the outside of the flexible gas pipe 1 to the nail 9, the electromagnetic wave enters the flexible gas pipe 1. And propagate. Therefore, in the configuration of FIG. 1, if the receiving device is connected to the antenna 11 attached to the tee 6 to operate as a receiving antenna, and the transmitting device is connected to the antenna 28 to operate as a transmitting antenna, the transmitting antenna can be oriented. By detecting the electromagnetic wave incident from the nail 9 and propagating in the flexible gas pipe 1 by the receiving device via the receiving antenna, damage to the flexible gas pipe 1 by the nail 9 can be detected.
[0034]
In the damage inspection described above, depending on the position of the flexible gas pipe 1 as a transmission path of the electromagnetic wave and the frequency of the electromagnetic wave used, the inside of the flexible gas pipe 1 is hardly leaked from the nail 9 that has damaged the flexible gas pipe 1 so as to prevent the leakage. An electromagnetic field distribution may be formed.
[0035]
In such a case, if the frequency of the electromagnetic wave propagated from the transmitting device into the flexible gas pipe 1 via the transmitting antenna is changed with time, leakage at a certain point in time and at a certain frequency may cause leakage from a leaking part. Even if a difficult electromagnetic field distribution occurs, the electromagnetic field distribution changes at a different frequency at the next point in time, so that the electromagnetic wave can be leaked from the location.
[0036]
In the above-described damage inspection, the receiving antenna of the receiving device receives various kinds of external noises in addition to the electromagnetic wave leaking from the nail 9, so that when the receiving device receives a certain electromagnetic wave, it is not received. If it is possible to discriminate between a leaked electromagnetic wave and a noise, the reliability of detection of a damaged portion is improved. Next, such a method will be described.
[0037]
First, a first method is a method of modulating an electromagnetic wave radiated by a transmission antenna of a transmission device with a desired signal. If the desired signal is a signal that can be identified by a person such as a voice or an image, for example, the person determines whether or not the electromagnetic wave received by the receiving device includes a predetermined sound or an image, and the leaked electromagnetic wave is determined. And noise can be identified.
[0038]
The second method is to turn on / off the radiation of the electromagnetic wave by the transmitting device, to perform the detection of the electromagnetic wave by the receiving device at both the ON time and the OFF time, and to change the received signal at the OFF time to the received signal at the ON time. This is a method of identifying an electromagnetic wave from the transmission device as compared with the method described above. When this method is applied, when the receiving device stops emitting the electromagnetic wave by the transmitting device while receiving a certain electromagnetic wave, if the received electromagnetic wave includes the electromagnetic wave from the transmitting device, the receiving device shown in FIG. As shown in FIG. 5), the reception level decreases, but when the electromagnetic wave being received is external noise, the reception level does not decrease as shown in FIG. By comparing the received signal with the signal at the time of OFF, it is possible to distinguish between electromagnetic waves and noise due to leakage.
[0039]
Since the receiving device only needs to know at least the ON time and the OFF time, ON / OFF of the electromagnetic wave can be performed by operating the receiving device, or the ON-OFF operation is performed by the transmitting device and the operation is performed. The signal can be transmitted to the receiving device side.
[0040]
【The invention's effect】
As described above, the present invention has the following effects.
a. Inspection for damage to the flexible gas pipe due to nails or the like in wall or floor construction can be performed without breaking the wall or floor.
b. Therefore, damage inspection can be easily performed in a short time.
c. There are few restrictions due to the configuration of the piping system.
d. Inspection is possible for both live and dead tubes.
[Brief description of the drawings]
FIG. 1 is a schematic diagram of the overall configuration of a first embodiment to which the method of the present invention is applied.
FIG. 2 is a sectional view of a main part of a second embodiment to which the method of the present invention is applied.
FIG. 3 is an explanatory diagram showing an example of a piping system on an upstream side of a flexible gas pipe for illustrating a place where an antenna is installed in the present invention.
FIG. 4 is a sectional view showing an embodiment of installation of an antenna according to the present invention.
FIG. 5 is an explanatory diagram showing an operation principle of discriminating leakage electromagnetic waves and noise based on ON-OFF of electromagnetic waves.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Flexible gas pipe 2 House 3 Outer wall 4 Inner wall 5 Single screw socket 6 Tee 7 Steel gas pipe 8 Gas meter 9 Nail 10 Transmitter 11 Antenna 12 Branch port 13 Plug 14a Female thread 14b Male thread 15 Lock nut 16a Female thread 16b Male thread Part 17 Coaxial cable 18 Center lead 19 Shield wire 20 Clamp 21 Washer 22 Gasket 23 Probe 24 Insulator 25 Flange 26 Radio wave shielding material 27 Receiver 28 Antenna 29 Probe

Claims (9)

A flexible gas pipe installed inside a wall or floor is radiated by an antenna of a transmitter installed at an appropriate position on its extension to radiate electromagnetic waves and propagate through the flexible gas pipe. A method for inspecting a flexible gas pipe for damage to a wall or a floor, comprising: detecting an electromagnetic wave by directing an antenna of a receiving device to the electromagnetic wave; and detecting damage by an electromagnetic wave leaking from the flexible gas pipe. A flexible gas pipe installed inside a wall or floor is radiated by an antenna of a transmitter installed at an appropriate position on its extension to radiate electromagnetic waves and propagate through the flexible gas pipe. A method for inspecting a flexible gas pipe for damage to a wall or a floor, wherein the probe detects electromagnetic waves by contacting a probe of a receiving device and detects damage by electromagnetic waves leaking from the flexible gas pipe. A flexible gas pipe installed inside a wall or floor is radiated by an antenna of a transmitter installed at an appropriate position on its extension to radiate electromagnetic waves and propagate through the flexible gas pipe. The antenna of the receiving device is searched for electromagnetic waves, and when the receiving device detects the electromagnetic waves, the probe is brought into contact with a nail in the direction of the antenna to search for the electromagnetic waves, and damage is caused by electromagnetic waves leaking from the flexible gas pipe. Detecting method for damage of flexible gas pipe in wall and floor construction characterized by detecting Attach the antenna of the receiving device to the appropriate place on the extension of the flexible gas pipe installed inside the wall and floor, and radiate the electromagnetic wave of the transmitting device antenna toward the nail struck on the wall and floor. A method of inspecting a flexible gas pipe for damage to walls and floors, wherein an electromagnetic wave propagating in the flexible gas pipe is monitored by a receiving device, and damage is detected by an electromagnetic wave incident from the outside into the flexible gas pipe. The method for inspecting a flexible gas pipe for damage on a wall or floor according to any one of claims 1 to 4, wherein the frequency of the electromagnetic wave is changed with time. The method for inspecting a flexible gas pipe for damage to a wall or floor according to any one of claims 1 to 4, wherein the electromagnetic wave emitted by the transmitting device is modulated by a desired signal. In addition to turning on and off the radiation of the electromagnetic wave by the transmission device, the detection of the electromagnetic wave by the reception device is performed at both the ON time and the OFF time, and the reception signal at the OFF time is compared with the reception signal at the ON time. The method for inspecting a flexible gas pipe for damage to a wall or a floor according to any one of claims 1 to 6, wherein the electromagnetic wave from the pipe is identified. An antenna inside the plug for closing the branch port of the tee being installed on the extension of the flexible gas pipe, according to claim 1-7, characterized in that to position the antenna in the tee in a state of attaching the plug Inspection method for flexible gas pipes in wall and floor construction according to any one of the above An antenna is formed inside a plug that can be screwed into a screw portion of a flexible gas pipe socket provided on an extension of the flexible gas pipe, and the antenna is positioned in the socket with the plug attached. The method for inspecting a flexible gas pipe for damage to a wall or a floor according to any one of claims 1 to 8.

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