JPH071168B2 - A method for investigating in-pipe conditions using reflected sound waves - Google Patents
A method for investigating in-pipe conditions using reflected sound wavesInfo
- Publication number
- JPH071168B2 JPH071168B2 JP59150705A JP15070584A JPH071168B2 JP H071168 B2 JPH071168 B2 JP H071168B2 JP 59150705 A JP59150705 A JP 59150705A JP 15070584 A JP15070584 A JP 15070584A JP H071168 B2 JPH071168 B2 JP H071168B2
- Authority
- JP
- Japan
- Prior art keywords
- pipe
- sound wave
- reflected
- wave
- investigating
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
- G01N29/14—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object using acoustic emission techniques
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
- G01N29/34—Generating the ultrasonic, sonic or infrasonic waves, e.g. electronic circuits specially adapted therefor
- G01N29/341—Generating the ultrasonic, sonic or infrasonic waves, e.g. electronic circuits specially adapted therefor with time characteristics
- G01N29/343—Generating the ultrasonic, sonic or infrasonic waves, e.g. electronic circuits specially adapted therefor with time characteristics pulse waves, e.g. particular sequence of pulses, bursts
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2291/00—Indexing codes associated with group G01N29/00
- G01N2291/01—Indexing codes associated with the measuring variable
- G01N2291/011—Velocity or travel time
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2291/00—Indexing codes associated with group G01N29/00
- G01N2291/01—Indexing codes associated with the measuring variable
- G01N2291/012—Phase angle
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2291/00—Indexing codes associated with group G01N29/00
- G01N2291/02—Indexing codes associated with the analysed material
- G01N2291/028—Material parameters
- G01N2291/02854—Length, thickness
Description
【発明の詳細な説明】 〔発明の技術分野〕 本発明は、管の内部状況を反射音波を利用して調査する
方法に関するものである。Description: TECHNICAL FIELD OF THE INVENTION The present invention relates to a method for investigating the internal condition of a tube by utilizing reflected sound waves.
地中に埋設された管、地上に設置された管、あるいは建
物に設置された管は経年とともに劣化するため、管の内
部状況を調査し、維持補修をしなければならない。Pipes buried in the ground, pipes installed on the ground, or pipes installed in buildings deteriorate over time, so the internal conditions of the pipes must be investigated and maintained.
従来、この種の管の内部状況を調査する方法としては、
パイプカメラあるいは、ファイバスコープを管内に挿入
し、これらの画像をモニタあるいはカメラに写して直視
する方法、また管内に通線体またはセンサを挿入し、間
接的に調査する方法などがあり、管内の異物の有無、管
の接続状況、折損、偏平状況等を調査している。Conventionally, as a method of investigating the internal condition of this type of pipe,
There is a method of inserting a pipe camera or a fiberscope into the tube and viewing these images directly on the monitor or camera, or a method of inserting a through wire or a sensor inside the tube and indirectly inspecting it. We are investigating the presence / absence of foreign matter, pipe connection, breakage, and flatness.
しかし、これら従来の方法は管の内部状況を定量的ある
いは定性的に調査できるものの、パイプカメラ、ファイ
バスコープ、通線体あるいはセンサ等を直接管内に挿入
する必要があるため、かなりの作業人員と調査時間を要
すという欠点があった。However, although these conventional methods can quantitatively or qualitatively investigate the internal condition of the pipe, it is necessary to insert a pipe camera, a fiberscope, a wire body or a sensor directly into the pipe, and therefore a considerable number of workers are required. There was a drawback that it took time to investigate.
本発明はこれらの欠点を解決するもので、管の一端に音
波送信子と音波受信子を設置し、音波送信子より音波パ
ルスを照射し、その反射波を音波受信子で測定すること
により管内の状況を定量的、定性的に調査し、なおかつ
短時間、少人数で調査し得る反射音波を利用した管内状
況調査方法を提供することを目的とする。The present invention solves these drawbacks by installing a sound wave transmitter and a sound wave receiver at one end of the tube, irradiating a sound wave pulse from the sound wave transmitter, and measuring the reflected wave with the sound wave receiver. It is an object of the present invention to provide a method for investigating in-pipe conditions using reflected sound waves, which enables quantitative and qualitative investigation of the situation of (1) and can be investigated by a small number of people in a short time.
本発明の反射音波を利用した管内状況調査方法につい
て、地中に埋設された通信ケーブル管路の場合の実施例
を図面によって説明する。Regarding the method for investigating the situation inside a pipe using reflected sound waves of the present invention, an embodiment in the case of a communication cable pipe buried in the ground will be described with reference to the drawings.
第１図は実施概要図であって、１は信号発生装置、２は
波形記憶装置、３は音波送信子の一例としてのコーンス
ピーカ、４は音波受信子の一例としてのエレクトレット
マイクロフォン、５は指示計、６は地中に埋設された通
信ケーブル収容管である。FIG. 1 is a schematic view of an embodiment, 1 is a signal generator, 2 is a waveform storage device, 3 is a cone speaker as an example of a sound wave transmitter, 4 is an electret microphone as an example of a sound wave receiver, and 5 is an instruction. A total of 6 is a communication cable housing pipe buried in the ground.
即ち、信号発生装置１で発生させた音波パルス信号を管
端に設置したコーンスピーカ３より管６内に照射する
と、管内空断面積が変化する箇所、すなわち、折損ある
いは偏平箇所Ａ、異物詰まり箇所Ｂ、継手部Ｃ等から反
射波が得られるとともに、コーンスピーカ３およびエレ
クトレットマイクロフォン４が設置されていない他端Ｄ
から反射波が得られる。この反射波をエレクトレットマ
イクロフォン４により受波し、波形記憶装置２に記憶す
る。That is, when the sound wave pulse signal generated by the signal generator 1 is applied to the inside of the tube 6 from the cone speaker 3 installed at the end of the tube, the area where the internal cross-sectional area of the tube changes, that is, the breakage or flattened area A and the foreign matter clogging area B, the reflected wave is obtained from the joint C, etc., and the other end D where the cone speaker 3 and the electret microphone 4 are not installed
The reflected wave is obtained from. The reflected wave is received by the electret microphone 4 and stored in the waveform storage device 2.
管６内へ照射する音波の周波数としては、管内の音波伝
播特性から減衰が少い平面波となる周波数帯域を使用す
るのがよく、通信ケーブル収容管６の場合管径が8cm程
度であるため、理論上1.2kHz以下が平面波として管内を
伝搬する。また、本発明者の実験によれば、低周波数ほ
ど管内断面積の変化を的確に捕える傾向にあるが、反面
低周波数にするほど雑音の周波数帯域に近くなり、反射
波の観測に支障を来すという欠点がある。そのため、本
実施例では、200Hz〜600Hz程度の周波数帯域をコーンス
ピーカ３から照射しており、その時の音波パルス信号幅
は1ms〜2msである。As the frequency of the sound wave to be radiated into the pipe 6, it is preferable to use a frequency band in which the sound wave propagation characteristic in the pipe is a plane wave with little attenuation. In the case of the communication cable housing pipe 6, the pipe diameter is about 8 cm. Theoretically 1.2 kHz or less propagates in the tube as a plane wave. Further, according to the experiments of the present inventor, the lower the frequency, the more the tendency of accurately capturing the change in the cross-sectional area of the tube, but the lower the frequency, the closer to the frequency band of the noise, which hinders the observation of the reflected wave. There is a drawback that Therefore, in the present embodiment, the cone speaker 3 irradiates the frequency band of about 200 Hz to 600 Hz, and the sound wave pulse signal width at that time is 1 ms to 2 ms.
なお、管径が変わった場合は、それに応じた周波数帯域
を使用することとなる。If the pipe diameter changes, the frequency band corresponding to the change will be used.
第２図は、波形記憶装置２に記憶された照射波形、反射
波形を波形記憶装置２の指示計５に表わしたものであ
り、図中Ｐは照射波、PAは折損あるいは偏平箇所Ａから
反射した反射波、PBは異物詰まり箇所Ｂから反射した反
射波、PCは継手部Ｃから反射した反射波、PDは他端Ｄか
ら反射した反射波である。またtA,tB,tC,tDは音波パル
スを発信してから反射波を受波するまでの時間であり、
これらの時間と管内音波伝播速度Ｖから の計算をすることにより管内空断面積の変化している位
置、すなわちＡ、Ｂ、ＣおよびＤ点までの距離を知るこ
とができる。FIG. 2 shows the irradiation waveform and the reflection waveform stored in the waveform storage device 2 in the indicator 5 of the waveform storage device 2, where P is the irradiation wave and P A is the breakage or flat portion A. The reflected wave reflected, P B is the reflected wave reflected from the foreign matter clogging point B, P C is the reflected wave reflected from the joint C, and P D is the reflected wave reflected from the other end D. Also, t A , t B , t C , t D is the time from transmitting the sound wave pulse to receiving the reflected wave,
From these times and the sound wave velocity V in the tube, By calculating, it is possible to know the position where the internal cross-sectional area of the pipe is changing, that is, the distance to points A, B, C and D.
また、照射波と反射波の位相を比較することにより、反
射波発生位置で管内空断面積が大きくなっているのか、
小さくなっているのか判定でき、反射波の位相が照射波
と同位相であれば管内空断面積が小さくなっていること
を示し、逆位相の場合は管内空断面積が大きくなってい
ることを示す。Also, by comparing the phases of the irradiated wave and the reflected wave, is it possible that the internal cross-sectional area of the pipe is increased at the reflected wave generation position?
It can be determined whether it is small, and if the phase of the reflected wave is the same as the irradiation wave, it indicates that the internal cross-sectional area of the pipe is small, and if it is the opposite phase, the internal cross-sectional area of the pipe is large. Show.
さらに、これらの反射波の振幅を測定することにより、
管内空断面積の変化量を推定することができる。反射波
の発生位置が同一であれば、振幅が大きいほど管内空断
面積の変化量が大きく、振幅が小さいほど管内空断面積
も小さいことを示す。Furthermore, by measuring the amplitude of these reflected waves,
It is possible to estimate the amount of change in the internal cross-sectional area of the pipe. If the generated position of the reflected wave is the same, it means that the larger the amplitude is, the larger the change amount of the in-pipe air cross-sectional area is.
これらのことから、第１図のような両端が開放された管
においては、照射波と同位相の反射波、第２図中では
PA、PBに注目した場合、管内に内空断面が小さくなって
いる所があるか否かが判定でき、あればその位置と小さ
くなっている程度を知ることができる。また、逆位相の
反射波、第２図中ではPC、PDに注目した場合、管内の内
空断面が大きくなっている所すなわち継手部Ｃの位置と
他端Ｄの位置を調査することができる。From these facts, in a tube whose both ends are open as shown in FIG. 1, a reflected wave having the same phase as the irradiation wave, in FIG.
When paying attention to P A and P B , it is possible to determine whether or not there is a part where the inner cross-section is small in the pipe, and if so, it is possible to know that position and the extent to which it has become smaller. Also, when paying attention to the antiphase reflected waves, P C and P D in Fig. 2, investigate where the inner cross-section in the pipe is large, that is, the position of the joint C and the position of the other end D. You can
以上述べたように本発明によれば、管の一端に音波送信
子と音波受信子を設置し、音波パルスを照射したのち反
射波を測定することにより、管内状況を定量的および定
性的に知ることができるとともに短時間、少人数で調査
することができる利点がある。As described above, according to the present invention, a sound wave transmitter and a sound wave receiver are installed at one end of a tube, and a reflected wave is measured after irradiating a sound wave pulse, so that the situation inside the tube can be quantitatively and qualitatively known. In addition to being able to do so, there is an advantage that a small number of people can be investigated in a short time.
また、本調査方法は実施例に限られたものではなく、地
上に設置された管、建物に設置された管など、一端が開
放されている管すべてに適用できる。Further, the present survey method is not limited to the examples, and can be applied to all pipes having one end opened, such as pipes installed on the ground and pipes installed in buildings.
第１図は本発明の一実施例の縦断面図、第２図は第１図
の波形記憶装置に記憶された照射波形図および反射波形
図である。 １……信号発生装置、２……波形記憶装置、３……コー
ンスピーカ、４……エレクトレットマイクロフォン、５
……指示計、６……通信ケーブル収容管。FIG. 1 is a vertical sectional view of an embodiment of the present invention, and FIG. 2 is an irradiation waveform diagram and a reflection waveform diagram stored in the waveform storage device of FIG. 1 ... Signal generator, 2 ... Waveform storage device, 3 ... Cone speaker, 4 ... Electret microphone, 5
…… Indicator, 6 …… Communication cable storage tube.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 梶尾 雄吾 東京都千代田区内幸町１丁目１番６号 日 本電信電話公社内 (56)参考文献 特公 昭51−18836（ＪＰ，Ｂ１) ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yugo Kajio 1-1-6 Uchisaiwaicho, Chiyoda-ku, Tokyo Nihon Telegraph and Telephone Public Corporation (56) References Japanese Patent Publication Sho 51-18836 (JP, B1)
Claims (1)
して、音波送信子により管内に音波パルスを照射し、管
内空断面積が変化する箇所で反射した音波を音波受信子
により測定し、照射波と反射波の位相を比較することに
より、反射波発生位置で管内空断面積が大きくなってい
るのか、小さくなっているのか判定することを特徴とす
る反射音波を利用した管内状況調査方法。1. A sound wave transmitter and a sound wave receiver are installed at one end of a pipe, and a sound wave pulse is applied to the inside of the pipe by the sound wave transmitter, and the sound wave reflected at a portion where the hollow cross-sectional area in the pipe changes is received by the sound wave receiver. By measuring and comparing the phases of the irradiated wave and the reflected wave, it is possible to determine whether the internal cross-sectional area of the pipe is large or small at the reflected wave generation position. Status investigation method.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59150705A JPH071168B2 (en) | 1984-07-20 | 1984-07-20 | A method for investigating in-pipe conditions using reflected sound waves |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59150705A JPH071168B2 (en) | 1984-07-20 | 1984-07-20 | A method for investigating in-pipe conditions using reflected sound waves |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6129757A JPS6129757A (en) | 1986-02-10 |
| JPH071168B2 true JPH071168B2 (en) | 1995-01-11 |
Family
ID=15502609
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP59150705A Expired - Fee Related JPH071168B2 (en) | 1984-07-20 | 1984-07-20 | A method for investigating in-pipe conditions using reflected sound waves |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH071168B2 (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6375554A (en) * | 1986-09-17 | 1988-04-05 | Nobuo Nakayama | Method and device for measurement utilizing acoustic wave |
| US7523667B2 (en) * | 2003-12-23 | 2009-04-28 | Rosemount Inc. | Diagnostics of impulse piping in an industrial process |
| JP4762675B2 (en) * | 2005-10-28 | 2011-08-31 | 能美防災株式会社 | Foam release test method and apparatus |
| JP2007309838A (en) * | 2006-05-19 | 2007-11-29 | Non-Destructive Inspection Co Ltd | Conduit inspection method and conduit inspection device used therefor |
| GB2441788B (en) * | 2006-09-15 | 2011-11-09 | Studor Sa | Method and equipment for detecting sealing deficiencies in drainage and vent systems for buildings |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5118836A (en) * | 1974-08-07 | 1976-02-14 | Mitsubishi Electric Corp | OKUNAI HAISENJOHODENSOHOSHIKI |
-
1984
- 1984-07-20 JP JP59150705A patent/JPH071168B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6129757A (en) | 1986-02-10 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |