JPH08271370A - Method and device for inspecting conduit - Google Patents

Abstract

PURPOSE: To provide a simple and easy conduit inspecting method capable of quickly estimating an opened/broken position developed on a gas pipe with good accuracy, for example. CONSTITUTION: A sound is generated at the open end section 16 of a gas pipe 2 hidden by a cover layer (earth) such as a city gas pipe buried in the ground. An acoustic wave is propagated in the gas pipe 2, and the acoustic wave propagated in the gas pipe 2 is received at multiple positions outside the cover layer. The spatial distribution of the received sound quantity is obtained, and the position of the gas pipe 2 or an opened/broken position A developed on the gas pipe 2 is estimated according to the obtained distribution of the received sound quantity.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention searches for the position of a pipe which is hidden by a coating layer such as soil or a wall of a house.
Furthermore, the present invention relates to a technique for determining a position where an opening is damaged in such a pipe.

[0002]

2. Description of the Related Art Conventionally, when searching for the position of a gas pipe, which is a type of pipe, the pipe position can be determined from the detection results by following the existing buried map or moving the radar locator on the ground side. I was indexing. On the other hand, when detecting the leak position (opening breakage position) of the gas pipe, a specific portion of the gas pipe network is partitioned, and the gas pressure is applied only to the gas pipe in this specific section to reduce the gauge pressure. If there is a drop while determining whether or not there is a leak position in this section, these sections are sequentially narrowed to estimate the leak position. Further, as a method for searching for the leakage position, a device capable of detecting the gas odor intensity, the gas concentration, etc. is moved on the ground side, for example, and the distribution of the gas concentration and the gas odor intensity is obtained. The location of high leakage was detected and the leak position was determined.

[0003]

The above-mentioned conventional techniques have the following problems, respectively. For example, in the case of gas piping, when estimating the position of the piping, this map is indispensable according to the buried map, and cannot be applied if there is no map. Furthermore, when using a radar locator, the size of the device is large, and when using a PE pipe or the like, it is difficult to adapt. On the other hand, when searching for a leak position (opening breakage position) in a pipe, if a method is used to judge whether the gauge pressure drops while dividing the pipeline network one by one, it is necessary to set the division one after another. It takes a lot of trouble. On the other hand, when adopting the method of identifying the leak position of the gas by the gas odor and the gas concentration, for example, it is necessary to supply the gas in the pipe where the gas supply is not started or the pipe where the gas supply is stopped. Yes, it is dangerous. Further, it cannot be used when the gas is not supplied in this way, and it is difficult to adopt it when no leakage occurs.
That is, the normal gas pipe is not used for checking the pipe position. Similar problems also exist for water supply piping and underground cable piping. Therefore, an object of the present invention is to solve the above various problems.

[0004]

To achieve this object, the characteristic means of the pipe inspection method according to claim 1 according to the present invention is that it produces a sound at the open end of the pipe hidden by the covering layer. First, the sound wave is propagated in the pipe.
And a second step of receiving a sound wave propagating in the pipe at a plurality of positions outside the coating layer to obtain a spatial distribution of the received sound volume, and a reception step obtained in the second step. It consists of a third step of estimating the position of the pipe or the position of opening breakage occurring in the pipe from the distribution of the sound volume. Further, in the pipeline inspection method according to claim 1, the pipe is a city gas pipe buried in the soil, and an open end of the pipe is an open end of a standpipe that is exposed to the ground. In the second step, it is preferable that, when the received sound volume distribution is obtained along the estimated embedding direction of the pipe, the position where the received sound volume is maximum is estimated as the opening breakage position. This is the characteristic means of the pipeline inspection method according to claim 2. Furthermore, in the pipe inspection method according to claim 1 or 2, the sound generated at the opening end in the first step is from a frequency of 300 Hz to 1
It is preferable that the sound is in the range of 100 Hz. This is the characteristic means of the pipeline inspection method according to claim 3.
Furthermore, in the pipe line inspection method according to claim 1, 2 or 3, the sound generated at the opening end in the first step is a sound within a frequency range of 300 Hz to 1100 Hz, and sound generation and generation. It is preferably an intermittent sound that repeats stopping. This is the characteristic means of the pipeline inspection method according to claim 4.

On the other hand, in order to achieve the above object, the pipe line inspection apparatus according to claim 5 is characterized in that the pipe line inspection device is attachable to the open end of the pipe hidden by the covering layer and produces a sound. Sounding means for propagating sound waves in the pipe,
At least one of a piezoelectric element, a microphone, a vibration element, or a combination thereof, and a receiving means capable of receiving a sound wave propagating in the gas pipe at a receiving position outside the coating layer, the receiving position A storage means for storing the noise in the above in advance, and when a sound wave generated by the sounding means and propagated in the pipe,
There is provided output means for removing the noise from the received sound received by the receiving means and outputting the noise. Further, the characteristic structure of the pipeline inspection device according to claim 6 is configured so that it can be attached to the open end of the pipe hidden by the covering layer, and it produces sound and propagates a sound wave in the gas pipe. Means and a piezoelectric element, a microphone, at least one of a vibration element, or a combination thereof, and a receiving means capable of receiving a sound wave propagating in the pipe at a receiving position outside the coating layer, The sounding means detects the wave in synchronization with the frequency of the sound wave propagated in the pipe, amplifies the received sound received by the receiving means, and as a result, removes the noise and outputs the output means. is there. Further, the characteristic structure of the pipe inspection device according to claim 7 is such that it can be attached to the open end of the pipe hidden by the coating layer, and it produces sound and propagates a sound wave in the gas pipe. Means and a piezoelectric element, a microphone, at least one of a vibration element, or a combination thereof, and a receiving means capable of receiving a sound wave propagating in the pipe at a receiving position outside the coating layer, There is provided output means for removing a sound having a frequency other than the frequency of the sound wave propagated in the pipe by the sounding means from the received sound received by the receiving means and outputting the sound. Further, the characteristic configuration of the pipe line inspection apparatus according to claim 8 for achieving the above object is configured to be attachable to an open end of a gas pipe hidden by a coating layer,
In addition, the sounding means for generating sound and propagating the sound wave in the pipe and the sound wave propagating in the pipe can be received at a plurality of reception positions outside the coating layer, and the spatial distribution of the reception sound volume can be detected. And an analysis output means for specifying and outputting the position of the pipe or the position of the opening breakage occurring in the pipe from the distribution of the reception sound volume obtained by the reception sound volume distribution detection device. Be prepared. The action and effect are as follows.

[0006]

In the pipe line inspection method according to claim 1 of the present application, in the first step, a sound wave is generated at the open end of the pipe and propagated in the pipe. This sound wave propagates in the pipe, and as shown in FIG. 1, if it leaks to the outside through the pipe wall of the pipe, or if there is an opening breakage at a specific portion of the pipe, it leaks into the coating layer from this portion. Therefore, in the second step, the leaked sound is detected outside the covering layer (for example, on the ground or outside the wall of the house). here,
Naturally, the spatial volume distribution of the leaked sound is
Depends on the location of the damaged opening. That is, for example, when the pipe is buried in the soil, the volume distribution along the pipe burying direction is relatively hard to have a peak, but in the direction perpendicular to this burying direction, it is directly above the pipe. It has a certain regularity that it is strong and weakens as it moves away from this position. Furthermore, if there is an opening breakage in the pipe due to an earthquake, etc., the volume distribution along the direction in which the pipe is buried is strong just above the opening breakage, and it is separated from this position. The weaker you get
Therefore, such a situation is detected in the second step of the present application. Then, in the third step, the position of the pipe or the position where the opening is damaged is determined and estimated from the obtained result based on the certain regularity as described above.

In the pipeline inspection method according to the second aspect of the present invention, the opening breakage position estimated to exist in the city gas pipe is searched. Such an opening breakage position is, for example, a portion where an existing pipe joint is detached due to an earthquake or the like. By the way, in this method, a standpipe equipped with a gas meter for households on the ground side, and further, a standpipe protruding from the coating layer to the open space side for mounting measuring instruments, etc. Sound waves are used to propagate into the gas pipe from the open end of such a standpipe. Then, in the second step, the distribution of the reception sound volume is obtained in advance along the known estimated pipe burying direction, and the position where the reception sound volume is maximum is estimated as the opening breakage position. In this method, it is not necessary to remove the coating layer (for example, in the case of a buried pipe, excavation of soil), and the opening breakage position can be estimated relatively easily.

In the pipe line inspection method according to the third aspect, while being propagated in the pipe, in the second step,
A specific range (frequency 300 Hz to 1100 Hz) as the sound that is received (or heard by humans)
The sound waves inside are used. According to the experiments conducted by the inventors, the sound wave in this frequency range is a sound that is particularly easy to identify when a worker hears a leak sound from a pipe buried in the soil on the ground. It was This is considered to be due to the fact that the sound is easily heard by the human ear with little attenuation in the soil. Therefore, when using the sound in such a frequency range, it becomes possible to accurately and easily detect the position of the pipe buried in the soil and the position where the opening is damaged. Furthermore, the same can be said for the gas pipes embedded in the wall of each home.

In the pipe line inspection method according to the fourth aspect, while being propagated in the pipe, in the second step,
A specific range (frequency 300 Hz to 1100 Hz) as the sound that is received (or heard by humans)
The sound waves within are used, and this is what is termed an intermittent sound. Sounds within this range are easy to identify when the operator hears them with the ear due to the frequency selection requirements, and are also easy to distinguish from surrounding noise because the sounds are intermittent. Therefore, when such a sound is used, it is possible to more reliably and easily detect the pipe embedded in the soil or the pipe embedded in the wall to proceed with the work.

The pipe line inspection apparatus according to the fifth aspect is provided with a sounding means, a receiving means, a storing means, and an output means. Here, the sounding means performs the function in the above-mentioned first step, is attached to the open end portion, and propagates the sound wave into the gas pipe. Then, the receiving means receives the sound wave leaking from the pipe on the ground side, for example. Further, the device is provided with a storage means, and this storage means
The noise at the place where the receiving means receives is stored.
This memory may be stored in advance to advance the work before the sound is propagated into the pipe by the sounding means,
Furthermore, noise of a general environment may be stored. Then, in the information transmission stage to the worker side, the output means outputs the information (sound) received by the receiving means from which this noise component is removed. Here, the output form may be an arbitrary form such as a voice signal, an electric signal, or a bar graph display signal. As a device for removing a noise component, a method of detecting in synchronism with the frequency of a sound wave generated by a sound wave unit and propagating to a pipe, amplifying a received sound received by a receiving unit, and consequently removing a noise component There is also. Further, as a device for removing a noise component, there is also a method of removing a sound having a frequency other than the frequency of the sound wave propagated in the pipe by the sounding means from the received sound received by the receiving means. In this way, by removing the noise at the receiving position from the information received by the receiving means and proceeding with the work, it is possible to perform reliable and simple estimation using only the necessary information.

The pipe line inspection apparatus according to the eighth aspect comprises a sounding means, a received sound volume distribution detecting means, and an analysis output means. Here, the sounding means performs the function in the above-mentioned first step, is attached to the opening end portion, and propagates the sound wave into the pipe. The reception volume distribution detecting means performs the function in the above-mentioned second step to obtain the spatial distribution of the reception volume. Then, the analysis output means analyzes and outputs the buried position of the pipe or the damaged position of the opening based on the detection result of the detection means. In this analysis, the analysis method sequence as described in the third step of the pipeline inspection method according to claim 1 is provided in the means, and the buried position of the pipe or the broken position of the opening is specified.

[0012]

In the pipe line inspection method according to the first aspect of the present invention, since the sound wave is used as the medium for the inspection work, the position of the pipe in the concealed state can be confirmed with a relatively simple device configuration. Furthermore, it is possible to proceed with the search and estimation of the opening breakage position occurring in this pipe. Furthermore, in the case of a gas pipe, it does not depend on the gas odor concentration, gas concentration, etc. as in the conventional case. Therefore, when the gas pipe is in the live pipe state, the gas is not supplied. In either case, you can easily proceed with the work.
Moreover, since it is not necessary to repeat the work of confirming the depressurized state in the partition while partitioning the piping network, the labor can be remarkably reduced. Further, in the pipeline inspection method according to claim 2, for estimating the opening damage position of the city gas pipe buried in the soil, for example, it goes to the ground without excavation work or the like. You can easily and quickly proceed using a vertical pipe. Further, in the duct inspection method according to the third aspect, when the worker hears the leak sound with his ears to proceed with the search work, the worker can easily identify the sound and proceed with the simple and quick work. it can. Further, in the duct inspection method according to claim 4, when a worker hears a leak sound with his / her ears and proceeds with a search operation, the sound can be identified more easily and surely, and is simple and quick. You can proceed with various tasks. Further, in the duct inspection device according to any one of claims 5 to 7, even when there is a lot of noise that causes a problem in the surrounding environment, the information related to the received sound in a state where this noise is removed can be obtained and accurate. You can search. Furthermore, in the pipe inspection apparatus according to the eighth aspect, the position of the pipe or the opening breakage position which may occur in the gas pipe can be automatically searched.

[0013]

Embodiments of the present application will be described with reference to the drawings. In FIGS. 1 and 4, respectively, using the pipeline inspection devices 1 and 100 of the present application, the opening breakage position A of the gas pipe 2 buried underground is shown.
The state of searching for is shown. 1 shows a state in which the worker 3 is proceeding with the work while listening to the sound leaking from the ground with general headphones 4, and the one shown in FIG. The equipped self-propelled inspection device 6 travels in a preset inspection area to obtain the distribution of the reception volume in this area, and based on this result, the analysis output device 7 automatically opens the opening. The output shows the damage position A.

First, the basic principle of the pipeline inspection method of the present application will be described below with reference to FIG. FIG. 1 shows a city gas piping system B for supplying city gas to each home 8. That is, for each home, for example, the front road 9
A low-pressure gas pipe 10 is buried in the home, and the pipe drawn from the low-pressure gas pipe 10 through the lead-in pipe 11 into the premises of each home 8 is once used as a stand pipe 12 on the ground. After being discharged, it is piped to the gas supply position (not shown) in each home. A gas meter (not shown) is arranged at a predetermined position of the standpipe 12. FIG. 1 shows that the worker 3 uses the piping inspection method of the present application to make the low-pressure gas pipe 10
The state in which the opening breakage portion 15 generated in the joint 14 of FIG. Here, no gas is supplied into the gas pipe, and there is no danger of gas leakage. In order to use the above-mentioned stand pipe 12 for the work, remove the gas meter (not shown) from the stand pipe 12,
A speaker 17 as a sounding means is attached to the open end 16 of the stand tube 12. The sound generated from the speaker 17 has a frequency of 1000 Hz and is an intermittent sound in which sound waves are repeatedly generated and stopped at a cycle of 2 Hz. Then, the worker 3 puts the headphones 4 on his or her ear based on the prepared map of the buried gas pipe (not shown) and proceeds with the work. As shown in FIG. 1, the headphone 4 includes a sound collecting cone 18 for collecting sound, and converts the sound collected by the sound collecting cone 18 into an electric signal and transmits the sound to the headphone 4 described above. The receiver 5 and the support rod 19 for supporting the sound collecting cone are provided. For this receiving device 5, a storage device 20 as storage means is provided.
When the speaker is used, ambient sound (noise) at the work place is captured and stored before the sound is generated by the speaker 17. Then, the noise component stored in the storage device 20 is removed from the sound collected by the reception device 5 by the conversion device 21,
Only the removed sound is the above-mentioned headphones 4 as an electric signal.
And is heard by the worker 3. A mechanism for removing the above-mentioned noise from the received sound received by the receiving unit and outputting the noise (specifically, the conversion device 21 and the headphones 4).
Is called output means.

The work procedure will be described below. 1 The worker 3 arrives at the work site as shown in FIG. At this point, we have prepared a burial map showing the burial location of the gas pipes near the construction site. 2 A gas meter (not shown) of a specific home 8 is removed from the standpipe 12, and a speaker 17 is attached to the open end 16. Around this work, noise that is an environmental sound is stored in the storage device 20 in a state where no sound is generated from the speaker 17. 3 Predetermined sound from speaker 17 (frequency 1000 Hz,
2 Hz intermittent sound) is generated and propagated in the gas pipe. This step is the first step of the pipe inspection method of the present application. 4 Then, according to the prepared burial map, the sound leaking from the gas pipe is received along the estimated burial direction of the pipe. As a result, it is possible to obtain the reception volume distribution along the estimated embedding direction. This step is the second step of the pipe inspection method of the present application. FIG. 2 shows how the received sound volume changes in this process. FIG. 2A shows the relationship between the opening defect portion 15 and the leakage sound receiving positions (P0 to P4), and FIG.
The change of the sound pressure level is shown when there is a slit-shaped opening breakage of about 0 mm. Itemize specific situations. Underground piping related gas piping 3 inch pipe Underground burial depth 60 cm Opening defect shape 10 mm slit Leakage sound receiving position (P0 to P4) Opening defect corresponding position and two locations in its vicinity In Fig. 2 (a), P0 is an opening It is a position corresponding to a defect (actually, a position directly above), and P1, P2, P3, and P4 are neighboring positions with no defect, respectively. In FIG. 2B, the above P0-
Change in received sound volume at the position indicated by P4 (distribution)
Is indicated by a solid line. As shown in the figure, it can be seen that the position immediately above the position where the opening defect is present has the highest volume and that the position of the opening defect can be estimated by this method. 5 Next, from the obtained distribution of the reception volume, the position where the reception volume is maximum is estimated as the opening breakage position A. This step is the third step of the pipe inspection method of the present application.

The above is a specific work procedure for advancing the work on the site. The following is a sound source position, which is the position of the speaker 17, which is a matter to be considered when advancing the work in this way. C and the result of examining the change status of the reception volume at the position along the gas pipe will be described. FIG.
In (a), the positional relationship between the sound source position C in which the speaker 17 is arranged at the open end 16 of the stand pipe 12 and the leak sound reception position P determined in advance along the gas pipe for this sound source. showed that. In the figure, P1 to 12 are leak sound reception positions, and an opening defect is provided immediately below the leak sound reception position P8. However, in order to receive the leakage sound, a receiving device (not shown) equipped with a lock-in amplifier was used, and the sound generated from the speaker was also a continuous sound. The specific situation is similar to that described above, but the following is a bulleted list. Buried piping relation Gas piping diameter 3 inches Gas piping underground burial depth 60 cm Opening defect shape 10 mm slit and 1 mm slit Fig. 3 (b) shows the experimental results. The horizontal axis of FIG. 3B indicates the leak sound reception position, and the vertical axis indicates the received sound volume level (displayed by the reception strength (mv)). In addition, the solid white circles show the results of 10 mm slits, and the broken line x marks show 1 mm
The result of the slit is shown. As a result, when the aim is to search for a 10 mm slit, a position (P
1, P2, P3) except for other sites (P4 to P1)
In 2), it can be seen that the opening defect position A can be estimated from the position where the received sound volume is the strongest.

The above is the result of the examination of the method of the present application in the relationship of proximity to and separation from the sound source position C. The worker 3 simply hears the leakage sound only with the headphones 4 and estimates the position of the opening defect. When proceeding with the work, the frequency of the sound to be emitted from the speaker 17 and its form become a problem. Here, when a person hears a sound by ear, the intermittent sound is easier to identify than the other noises than the continuous sound. Therefore, in the method of the present application, such an intermittent sound is adopted. The inventors determined the easiness of hearing when the frequency of the generated sound was changed and heard by the ear under the following conditions. Buried pipe relation Gas pipe diameter 3 inches Gas pipe underground burial depth 60 cm Opening defect shape 10 mm Slit Distance between sound source and opening defect shape 2.9 m Leakage sound reception position Site directly above opening defect Sound relation generated from speaker Interval between generation and stop of generation 2 Hz Frequency of sound changed from 200 to 2 KHz The results are shown in Table 1. In the table, ◎ indicates that the results were very easy to hear and good results, ○ indicates those that were easy to hear, and △
Indicates that there is a problem with ease of listening, and × indicates that it is difficult to hear.

[0018]

[Table 1] As a result, when trying to make a distinction by hearing with the human ear, 4
It can be seen that sounds in the range 00 Hz to 1100 Hz are preferred.

[Other Embodiments] As described above,
In the pipeline inspection method of the present application, by receiving the sound waves propagating in the gas pipe outside the coating layer such as soil and walls, the distribution state can be used to, for example, improve the opening breakage position of the gas pipe. Can be estimated. Here, in the above-mentioned embodiment, the opening is broken in the gas pipe, and the position is estimated by capturing the sound leaking from this opening. Not only does it leak, but even when the gas pipe is in a normal state with no opening, it leaks into the ground through the pipe wall and can be caught on the ground. Thus, for example, the second
In detecting the reception volume distribution in the process, once the survey was conducted in a direction almost orthogonal to the estimated buried direction of the gas pipe, the position directly above the buried position became the position where the strongest received sound was heard, and in this direction. The burying position of the gas pipe in it is known. Then, by repeating this operation one after another while moving in the estimated embedding direction of the gas pipe to connect the positions where the reception volume is strong, the embedding position of the gas pipe can be satisfactorily searched.

Further, in the above embodiment, the speaker is used for generating the sound, but as such a device,
Sirens, horns, whistles, bells, etc. can be used. A device that generates a sound for the purpose of the present application is called a sound producing means. Further, in the above embodiment, the receiving device was used for receiving sound, but as such a device, a piezoelectric element, a microphone, a vibrating element, or the like can be used.

The above is the embodiment in which the worker puts the headphones on his ears and walks to perform the exploration.
A pipeline inspection apparatus 100 of the present application that automatically searches will be described with reference to FIG. The configuration of the device on the sound source side in this device 100 is the same as that described above. By the way, the device on the receiving side includes a self-propelled detection device 6, and an analysis output device 7 as an analysis output means for analyzing and displaying and outputting the opening damage position A existing in the gas pipe from the detection result by the detection device 6. It is configured with. The detection device 6 includes a device main body 60 that can travel along a preset route, and also includes the reception device 5 described above. Further, the traveling control device 6 for controlling the traveling situation of the device body 60.
1 in the main body 60. Therefore, with this configuration, the detection device 6 can receive the sound leaking at each point on the route while traveling on the preset route and obtain the distribution of the reception volume. The analysis output device 7
Is configured to analyze the detection information sent from the detection device 6 and output the pipe position and the opening damage position. FIG. 4 shows a situation in which the inspection device 4 travels along a pre-determined buried route of the gas pipe and displays the distribution of the received sound volume on this moving route in relation to its position. ing. In the display screen 70 included in the analysis output device 7, the horizontal axis indicates the spatial position and the vertical axis indicates the reception volume. On the screen, the distribution of the reception volume is shown by the solid line. Further, the estimated position of the opening breakage and the arrow D are shown on the screen, which is the position obtained by the analysis. Now, the analysis in the analysis output device 7 goes through the following sequence. First, the traveling mode of the detection device 6 is configured to be set in two ways. These traveling modes are a first mode in which the inspection device 6 travels along the direction in which the gas pipe is buried, which is roughly known in advance, and a second mode in which the inspection device 6 travels in a direction perpendicular to the first mode. Then, when traveling in the second mode, this traveling mode is repeated while moving at a predetermined pitch along the burying direction of the gas pipe. When the detection device 6 travels in the first mode, the analysis output device 7
When the received sound volume transmitted from the inspection device 6 draws a certain peak state, this position is estimated to be the opening breakage estimated position A, and this state is shown in FIG. is there. It is also required that the peak is steep in order to be judged as the opening damage. On the other hand, when the detection device 6 travels in the second mode, in the analysis output device 7, when the received sound volume transmitted from the inspection device 6 draws a constant peak state, this position is set to the gas pipe. The position is estimated. Then, by repeating the sequential movement survey along the burying direction of the gas pipe, the position where the jumping peak appears is defined as the opening breakage position A with respect to the standard peak intensity obtained in each second mode traveling state. presume. On the other hand, when such a jumping peak does not appear, it is analyzed and determined that there is no opening damage, and the display screen shows that the gas pipe is normal. In this way, the pipeline inspection apparatus 100 in this example can automatically search. Here, a mechanism capable of receiving sound waves propagating in the gas pipe at a plurality of receiving positions outside the coating layer and capable of detecting the spatial distribution of the reception sound volume is referred to as reception sound volume distribution detecting means. In the above-mentioned pipe line inspection device, the inspection device is provided with this mechanism. Further, a unit for specifying and outputting the position of the gas pipe or the position of the opening breakage occurring in the gas pipe from the distribution of the received sound volume obtained by the received sound volume distribution detecting unit is referred to as analysis output unit. In the above-mentioned pipeline inspection device, the analysis output device has this mechanism. In the above automatic detection, the running state is determined using the buried map of the gas pipe as basic data,
Although this map seems to be indispensable, since the gas pipe is generally buried in the road formation direction, the pipe embedding direction can be roughly estimated. Therefore, the buried map is not always necessary, and by using this device, reliable and simple inspection can be performed. In the above-mentioned embodiment, the application to the gas pipe has been described, but the pipe is not limited to this, and the present invention can be applied to any pipe such as a water supply pipe and a buried pipe of an underground cable.

It should be noted that reference numerals are given in the claims for convenience of comparison with the drawings, but the present invention is not limited to the configurations of the accompanying drawings by the entry.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a state in which an opening breakage position where a gas pipe exists is searched using the pipeline inspection device of the present application.

FIG. 2 is an explanatory diagram showing a distribution state of reception volume along a gas pipe.

FIG. 3 is an explanatory diagram showing a distribution state of received sound volume in a direction away from a sound source.

FIG. 4 is an explanatory view showing an operating state of another embodiment of the duct inspection device of the present application including a self-propelled inspection device.

[Explanation of symbols]

 2 Gas piping 5 Receiving means 12 Standpipe 16 Opening end 17 Sounding means 20 Storage means A Opening damaged position

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location G01N 29/04 G01N 29/04 (72) Inventor Takashi Kikuta 4-chome, Hirano-cho, Chuo-ku, Osaka-shi, Osaka 1-2, Osaka Gas Co., Ltd. (72) Inventor, Masashi Nishigaki, 4-1-2, Hirano-cho, Chuo-ku, Osaka City, Osaka Prefecture Osaka Gas Co., Ltd.

Claims (8)

[Claims] 1. A first step of propagating a sound wave in the pipe (2) by generating sound at an open end (16) of the pipe (2) hidden by a coating layer, and the pipe (2). A second step of receiving a sound wave propagating inside at a plurality of positions outside the coating layer to obtain a spatial distribution of the received sound volume, and from the distribution of the received sound volume obtained in the second step, A pipeline inspection method comprising a third step of estimating a position of the pipe (2) or an opening breakage position (A) occurring in the pipe (2). 2. The pipe (2) is a city pipe buried in the soil, and the open end (1) of the pipe (2).
6) is the opening end of the standpipe (12) that is exposed to the ground, and the position where the received sound volume is maximum when the received sound volume distribution is obtained along the estimated pipe burying direction in the second step. Is estimated as the opening breakage position (A). 3. The opening end portion (1) in the first step.
The sound generated in 6) has a frequency of 300 Hz to 1100.
The pipe line inspection method according to claim 1 or 2, which is a sound within a range of Hz. 4. The opening end portion (1) in the first step.
The sound generated in 6) has a frequency of 300 Hz to 1100.
The pipe line inspection method according to claim 1, 2 or 3, which is a sound within a range of Hz and is an intermittent sound in which sound generation and generation stop are repeated. 5. A sounding means (17) configured to be attachable to the open end (16) of the pipe (2) hidden by the covering layer and for generating a sound to propagate a sound wave into the pipe. A piezoelectric element, a microphone, at least one of a vibration element, or a combination thereof, and a reception means (5) capable of receiving a sound wave propagating in the pipe at a reception position outside the coating layer, A storage means (20) for preliminarily storing noise at the reception position (5) is provided, and the reception means is generated at the time when the sound wave generated by the sound generation means (17) and propagated in the pipe (2). A pipe line inspection apparatus comprising an output means for removing the noise from the received sound received in (5) and outputting the noise. 6. A sounding means (17) configured to be attachable to an open end (16) of a pipe (2) hidden by a covering layer and for generating a sound to propagate a sound wave in the gas pipe.
And a receiving means (5) comprising at least one of a piezoelectric element, a microphone, a vibrating element, or a combination thereof, and capable of receiving a sound wave propagating in the pipe at a receiving position outside the coating layer. , The sounding means (17) detects in synchronization with the frequency of the sound wave propagated in the pipe (2), amplifies the received sound received by the receiving means (5), and consequently removes the noise. A pipe line inspection device having an output means for outputting. 7. A sounding means (17) configured to be attachable to an open end (16) of a pipe (2) hidden by a coating layer and for generating a sound to propagate a sound wave into the gas pipe.
And a receiving means (5) comprising at least one of a piezoelectric element, a microphone, a vibrating element, or a combination thereof, and capable of receiving a sound wave propagating in the pipe at a receiving position outside the coating layer. Output means for removing a sound having a frequency other than the frequency of the sound wave propagated in the pipe (2) by the sounding means (17) from the received sound received by the receiving means (5) and outputting the sound. Pipe inspection equipment. 8. A sounding means (1) configured to be attachable to an open end (16) of a pipe (2) hidden by a covering layer and for generating a sound to propagate a sound wave into the pipe (2).
7), and reception volume distribution detecting means capable of receiving sound waves propagating in the pipe (2) at a plurality of reception positions outside the coating layer and capable of detecting spatial distribution of reception volume, An analysis output unit for estimating and outputting the position of the pipe (2) or the opening breakage position (A) occurring in the pipe (2) from the distribution of the reception volume obtained by the reception volume distribution detection unit is provided. Pipe inspection equipment.