JPS6161074B2 - - Google Patents
Info
- Publication number
- JPS6161074B2 JPS6161074B2 JP52127823A JP12782377A JPS6161074B2 JP S6161074 B2 JPS6161074 B2 JP S6161074B2 JP 52127823 A JP52127823 A JP 52127823A JP 12782377 A JP12782377 A JP 12782377A JP S6161074 B2 JPS6161074 B2 JP S6161074B2
- Authority
- JP
- Japan
- Prior art keywords
- buried metal
- metal pipe
- changeover switch
- current
- pipes
- 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
Links
- 239000002184 metal Substances 0.000 claims description 37
- 238000001514 detection method Methods 0.000 claims description 18
- 230000010355 oscillation Effects 0.000 claims description 7
- 238000006243 chemical reaction Methods 0.000 claims description 2
- 238000010292 electrical insulation Methods 0.000 description 8
- 238000000034 method Methods 0.000 description 8
- 239000006185 dispersion Substances 0.000 description 6
- WABPQHHGFIMREM-UHFFFAOYSA-N lead(0) Chemical compound [Pb] WABPQHHGFIMREM-UHFFFAOYSA-N 0.000 description 6
- 239000010426 asphalt Substances 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 239000004698 Polyethylene Substances 0.000 description 2
- 238000005536 corrosion prevention Methods 0.000 description 2
- -1 polyethylene Polymers 0.000 description 2
- 229920000573 polyethylene Polymers 0.000 description 2
- 240000000491 Corchorus aestuans Species 0.000 description 1
- 235000011777 Corchorus aestuans Nutrition 0.000 description 1
- 235000010862 Corchorus capsularis Nutrition 0.000 description 1
- 229910000831 Steel Inorganic materials 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 239000003990 capacitor Substances 0.000 description 1
- 238000005253 cladding Methods 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005246 galvanizing Methods 0.000 description 1
- 230000006698 induction Effects 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000010422 painting Methods 0.000 description 1
- 229920013716 polyethylene resin Polymers 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
Landscapes
- Geophysics And Detection Of Objects (AREA)
Description
【発明の詳細な説明】
この発明は直接法による埋設金属管の探知装置
に関するものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a buried metal pipe detection device using a direct method.
一般に、ガス導管等の埋設金属管の被覆および
塗装は防食対策上重要であり、特に、鋼管におい
ては非常に重要である。この埋設金属管は、従来
からアスフアルト巻、アスフアルトジユート巻、
テープ巻あるいは亜鉛めつき等を施すことにより
防食対策を講じているが、電気絶縁性が良くはな
かつた。ところが最近では、上述のものに替えて
耐食性および電気絶縁性の優れたポリエチレン樹
脂で被覆したポリエチレン被覆管が使用されてい
る。 In general, coating and painting buried metal pipes such as gas pipes are important for corrosion prevention, and are particularly important for steel pipes. This buried metal pipe has traditionally been wrapped in asphalt, wrapped in asphalt jute, or wrapped in asphalt.
Corrosion prevention measures were taken by wrapping with tape or galvanizing, but the electrical insulation was not good. However, recently, polyethylene cladding tubes coated with polyethylene resin having excellent corrosion resistance and electrical insulation have been used instead of the above-mentioned tubes.
従来、このような多種多様の埋設金属管の埋設
場所の探知装置として誘導法と直接法とがあつた
が、前者はいわゆる非接触方式で管に接すること
なく、発信器のアンテナを利用して高周波電磁波
を発信し、埋設金属管に誘導された高周波電流に
よる二次磁界をサーチコイルによつてピツクアツ
プして探知するものであつたため、埋設管が複数
本近接して平行に走つているときや、交差してい
る場合、これらの他の埋設管も探知してしまい、
測定精度に欠けるという欠点がある。一方後者は
いわゆる接触方式であるためこのような欠点がな
い。すなわち、直接法は、埋設金属管の一点とア
ースとの間に通電した一種類（発振周波数数十
KHz）の交流電流によつて埋設金属の近傍に形
成される交番磁界を検出することにより埋設金属
管を探知する埋設金属管の探知装置により行なう
ものである。しかし、この埋設金属管の探知装置
は、電気絶縁性の高い埋設金属管に対しては埋設
金属管から大地に分散する分散電流が少なく、電
気絶縁性の低い埋設金属管に対しては分散電流が
多く、適度な分散電流を得ることができないため
探知精度が悪いという欠点があつた。また、埋設
金属管の長さにより分散電流の値が異なり適度な
分散電流を得ることができないため探知精度が悪
いという欠点もあつた。 Conventionally, there have been two methods for detecting the location of these various types of buried metal pipes: the induction method and the direct method. This system emitted high-frequency electromagnetic waves and used a search coil to pick up and detect the secondary magnetic field caused by the high-frequency current induced in the buried metal pipes. , if they intersect, these other buried pipes will also be detected,
The disadvantage is that measurement accuracy is lacking. On the other hand, the latter method does not have such drawbacks because it is a so-called contact method. In other words, the direct method is one type in which current is passed between one point of the buried metal pipe and the earth (oscillation frequency of several tens of
This is done using a buried metal pipe detection device that detects buried metal pipes by detecting an alternating magnetic field created near the buried metal by alternating current (KHz). However, with this buried metal pipe detection device, there is little dispersion current dispersing from the buried metal pipe to the ground for buried metal pipes with high electrical insulation, and the dispersion current for buried metal pipes with low electrical insulation is small. The problem was that detection accuracy was poor because it was not possible to obtain a suitable distributed current. Another drawback was that the detection accuracy was poor because the value of the dispersion current varied depending on the length of the buried metal pipe, making it impossible to obtain an appropriate dispersion current.
したがつて、この発明の目的は、たとえ、近接
した平行管や交差管が存在してもまた短い分岐パ
イプが附近に存在していても、埋設金属管の電気
絶縁性の高低あるいは管長の長短に拘らず、埋設
位置やルートを、常に適正に精度よく探知するこ
とができる埋設金属管の探知装置を提供すること
である。 Therefore, the purpose of this invention is to determine the level of electrical insulation of buried metal pipes or the length of pipes, even if there are parallel pipes or cross pipes in the vicinity, or even if there are short branch pipes nearby. It is an object of the present invention to provide a buried metal pipe detection device that can always properly and accurately detect the buried position and route regardless of the situation.
この発明の埋設金属管の探知装置は、埋設金属
管の電気絶縁性の高低あるいは管長に応じて高周
波電流と低周波電流とを使い分けたことを特徴と
する。 The buried metal pipe detection device of the present invention is characterized in that a high frequency current and a low frequency current are used depending on the level of electrical insulation of the buried metal pipe or the length of the pipe.
つぎに、この発明の基礎となる原理について説
明する。まず、高周波電流の周波数の選択はつぎ
のようにして行なつた。第１図に被探知管Ｓ（ポ
リエチレン被覆管）に発信器Ｔを接続したときの
状態を示す。この図において、I0は発信器Ｔから
被探知管Ｓに流入する電流、ＩAは被探知管Ｓを
流れる電流、ＩBは被探知管Ｓから大地Ｅに分散
する分散電流である。第１図の高周波的な等価回
路は、第２図に示すように、発信器Ｔ、インダク
タンスＬa、抵抗Ｒaおよび容量Ｃaより構成され
る。第１図の発信器Ｔと被探知管Ｓとの接続回路
における発信器Ｔより被探知管Ｓに流入する電流
I0と発信器Ｔの発信周波数との関係（出力電圧一
定）を測定した結果は第３図に示すとおりであ
る。これによると、発信周波数60KHzを超える
と徐々に電流が増加し、発信周波数90KHzで一
定になり安定状態になつている。なお、発信周波
数がさらに高くなればインダクタンスＬaの影響
で電流が減少すると思われる。したがつて、発信
器Ｔの発信周波数として最適な周波数は90KHz
から電波法の問題に関係しない100KHzまでの周
波数範囲である。このような高周波は分散電流が
多く、絶縁性の高い埋設金属管や短距離の埋設金
属管、特に分岐管の探知に効果がある。また、低
周波電流は、分散電流が少ないため、絶縁性の低
い埋設金属管や長距離の埋設金属管に都合がよ
い。 Next, the principle underlying this invention will be explained. First, the frequency of the high-frequency current was selected as follows. FIG. 1 shows a state in which a transmitter T is connected to a tube S to be detected (polyethylene clad tube). In this figure, I 0 is the current flowing from the transmitter T into the tube S to be detected, I A is the current flowing through the tube S to be detected, and I B is the dispersed current distributed from the tube S to the earth E. As shown in FIG. 2, the high-frequency equivalent circuit in FIG. 1 is composed of an oscillator T, an inductance L a , a resistor R a and a capacitor C a . Current flowing into the detected tube S from the transmitter T in the connection circuit between the transmitter T and the detected tube S in Fig. 1
The results of measuring the relationship between I 0 and the oscillation frequency of the oscillator T (at a constant output voltage) are shown in FIG. According to this, the current gradually increases when the oscillation frequency exceeds 60KHz, and becomes constant at the oscillation frequency of 90KHz, resulting in a stable state. Note that if the oscillation frequency becomes higher still, the current will probably decrease due to the influence of the inductance L a . Therefore, the optimum frequency for transmitter T's transmission frequency is 90KHz.
The frequency range is from Such high frequencies have a large amount of dispersion current and are effective in detecting highly insulated buried metal pipes, short-distance buried metal pipes, and especially branch pipes. In addition, low-frequency current has little dispersion current, so it is convenient for buried metal pipes with low insulation properties and long-distance buried metal pipes.
この発明の一実施例を第４図に示す。すなわ
ち、この埋設金属管の探知装置は、発信器Ｔ、検
出器Ｐおよび受信器Ｒで構成されている。この場
合、発信器Ｔは、96KHzの高周波発振器１、増
幅器２、2KHzの低周波発振器３、増幅器４、連
動するスイツチ５，６、端子７，８およびアース
端子９より構成されている。また、受信器Ｒは、
98KHzの高周波発振器１０、増幅器１１、トラ
ンス１２、レベル調節器１３、連動するスイツチ
１４，１５、トランス１６、増幅器１７，１８、
トランス１９、増幅器２０、トランス２１、フイ
ルタ２２、増幅器２３、感度調節器２４、フイル
タ２５、増幅器２６、検波器２７、メータ２８、
音量調節器２９、増幅器３０，３１およびスピー
カ３２より構成されている。さらに、検出器Ｐは
スイツチ１４の共通端子に接続されている。 An embodiment of this invention is shown in FIG. That is, this buried metal pipe detection device is composed of a transmitter T, a detector P, and a receiver R. In this case, the oscillator T is composed of a 96 KHz high frequency oscillator 1, an amplifier 2, a 2 KHz low frequency oscillator 3, an amplifier 4, interlocking switches 5, 6, terminals 7, 8 and a ground terminal 9. Moreover, the receiver R is
98KHz high frequency oscillator 10, amplifier 11, transformer 12, level adjuster 13, interlocking switches 14, 15, transformer 16, amplifiers 17, 18,
Transformer 19, amplifier 20, transformer 21, filter 22, amplifier 23, sensitivity adjuster 24, filter 25, amplifier 26, detector 27, meter 28,
It is composed of a volume controller 29, amplifiers 30 and 31, and a speaker 32. Furthermore, the detector P is connected to the common terminal of the switch 14.
つぎに、この実施例の動作を説明する。 Next, the operation of this embodiment will be explained.
(1) 高周波を使用する探知（スイツチ５，６，１
４，１５を実線側に倒し、リード線L1を端子
７に接続する。）：発信器Ｔの端子７から高周
波電流Ｉが出力され、実線で示すリード線L1
を通して被探知管Ｓに流入する。この高周波電
流Ｉは、被探知管Ｓを流れ、大地Ｅを通して電
極Ｕに達し、リード線L2を通してアース端子
９にもどる。このときに、高周波電流Ｉにより
被探知管Ｓの中心軸を中心として同心円状に磁
界Ｈが生じる。この磁界Ｈを検出器Ｐが、地面
を走査することにより検出して高周波電気信号
に変換する。この高周波電気信号は、受信器Ｒ
に入力されビートダウン方式により2KHzの低
周波電気信号に変換され、この低周波電気信号
がメータ２８により表示されるとともにスピー
カ３２により報知される。(1) Detection using high frequency (switches 5, 6, 1
4 and 15 to the solid wire side, and connect lead wire L 1 to terminal 7. ): High frequency current I is output from terminal 7 of transmitter T, and lead wire L 1 is shown as a solid line.
It flows into the tube S to be detected through the tube. This high frequency current I flows through the tube S to be detected, reaches the electrode U through the earth E, and returns to the earth terminal 9 through the lead wire L2. At this time, a magnetic field H is generated concentrically around the central axis of the tube S to be detected by the high frequency current I. A detector P detects this magnetic field H by scanning the ground and converts it into a high frequency electric signal. This high frequency electrical signal is transmitted to the receiver R
The signal is inputted into a 2KHz low frequency electrical signal using the beatdown method, and this low frequency electrical signal is displayed by the meter 28 and notified by the speaker 32.
(2) 低周波を使用する探知（スイツチ５，６，１
４，１５を破線側に倒し、リード線L1を端子
８に接続する。）：発信器Ｔの端子８から低周
波電流が出力され、破線で示すリード線L1を
通して被探知管Ｓに流入する。この低周波電流
は、被探知管Ｓを流れ、大地Ｅを通して電極Ｕ
に達し、リード線L2を通してアース端子９に
もどる。このときに、低周波電流により被探知
管Ｓの中心軸を中心として同心円状に磁界が生
じる。この磁界を検出器Ｐが地面を走査するこ
とにより検出して低周波電気信号に変換する。
この低周波電気信号が受信器Ｒに入力され、メ
ータ２８により表示されるとともにスピーカ３
２により報知される。(2) Detection using low frequency (switches 5, 6, 1
4 and 15 to the dotted line side, and connect lead wire L 1 to terminal 8. ): A low frequency current is output from the terminal 8 of the transmitter T and flows into the tube to be detected S through the lead wire L1 shown by the broken line. This low frequency current flows through the tube S to be detected, passes through the earth E, and then passes through the electrode U.
, and returns to the ground terminal 9 through lead wire L 2 . At this time, a magnetic field is generated concentrically around the central axis of the tube S to be detected due to the low frequency current. The detector P detects this magnetic field by scanning the ground and converts it into a low frequency electric signal.
This low frequency electrical signal is input to the receiver R, is displayed by the meter 28, and is also transmitted to the speaker 3.
Notification is made by 2.
このように、被探知管Ｓの埋設場所に検出器Ｐ
が近づくとメータ２８およびスピーカ３２が動作
し、視覚および聴覚により被探知管の埋設位置が
探知できる。 In this way, the detector P is installed at the location where the tube to be detected S is buried.
When it approaches, the meter 28 and speaker 32 are activated, and the buried position of the tube to be detected can be detected visually and audibly.
このように構成することにより、電気絶縁性の
高低あるいは埋設金属管の長短に対応して、高周
波電流と低周波電流とを使い分けて分散電流量を
調整でき、埋設金属管の探知精度が向上し、探知
が容易になる。 With this configuration, the amount of distributed current can be adjusted by using high-frequency current and low-frequency current depending on the level of electrical insulation or the length of the buried metal pipe, improving the detection accuracy of buried metal pipes. , which makes detection easier.
以上のように、この発明の埋設金属管の探知装
置は、埋設金属管に発振出力を供給するための
90KHz以上の発振部および60KHz以下の発振部
を設けかつこれらの発振部を選択的に切換えるた
めの第１の切換スイツチを設けた発振器と、前記
埋設金属管のまわりに発生した磁界を検出するた
めの電磁変換型の検出器と、前記第１の切換スイ
ツチに対応する第２の切換スイツチを介して前記
検出器の出力信号を検出するための高周波検出回
路および低周波検出回路を設けた受信器とを備
え、前記埋設金属管の種類に応じて前記第１の切
換スイツチおよび第２の切換スイツチを切換える
ようにしたことを特徴とするものである。 As described above, the buried metal pipe detection device of the present invention is for supplying oscillation output to the buried metal pipe.
An oscillator provided with an oscillating part of 90 KHz or more and an oscillating part of 60 KHz or less, and a first changeover switch for selectively switching these oscillating parts, and for detecting the magnetic field generated around the buried metal pipe. A receiver comprising an electromagnetic conversion type detector, and a high frequency detection circuit and a low frequency detection circuit for detecting the output signal of the detector via a second changeover switch corresponding to the first changeover switch. The apparatus is characterized in that the first changeover switch and the second changeover switch are changed over depending on the type of the buried metal pipe.
このため、たとえ近接した平行管や交差管が存
在していてもまた短い分岐パイプが付近に存在し
ていても、埋設金属管の電気絶縁性の高低あるい
は埋設金属管の管長の長短にかかわらず、埋設金
属管の埋設位置やルートを常に適正に精度よく探
知することができるという効果がある。 For this reason, even if parallel pipes or cross pipes exist in close proximity, even if short branch pipes exist nearby, regardless of the level of electrical insulation of the buried metal pipe or the length of the buried metal pipe, This has the effect that the buried position and route of the buried metal pipe can always be detected properly and accurately.
第１図は埋設金属管と発信器の接続回路図、第
２図はその等価回路図、第３図は第２図の等価回
路の電流周波数特性図、第４図はこの発明の一実
施例のブロツク図である。
Ｔ……発信器、Ｒ……受信器、Ｐ……検出器。
Fig. 1 is a connection circuit diagram between the buried metal pipe and the transmitter, Fig. 2 is its equivalent circuit diagram, Fig. 3 is a current frequency characteristic diagram of the equivalent circuit of Fig. 2, and Fig. 4 is an embodiment of the present invention. FIG. T...transmitter, R...receiver, P...detector.
Claims (1)
90KHz以上の発振部および60KHz以下の発振部
を設けかつこれらの発振部を選択的に切換えるた
めの第１の切換スイツチを設けた発振器と、前記
埋設金属管のまわりに発生した磁界を検出するた
めの電磁変換型の検出器と、前記第１の切換スイ
ツチに対応する第２の切換スイツチを介して前記
検出器の出力信号を検出するための高周波検出回
路および低周波検出回路を設けた受信器とを備
え、前記埋設金属管の種類に応じて前記第１の切
換スイツチおよび第２の切換スイツチを切換える
ようにしたことを特徴とする埋設金属管の探知装
置。1. For supplying oscillation output to buried metal pipes
An oscillator provided with an oscillating part of 90 KHz or more and an oscillating part of 60 KHz or less, and a first changeover switch for selectively switching these oscillating parts, and for detecting the magnetic field generated around the buried metal pipe. A receiver comprising an electromagnetic conversion type detector, and a high frequency detection circuit and a low frequency detection circuit for detecting the output signal of the detector via a second changeover switch corresponding to the first changeover switch. 1. A buried metal pipe detection device, characterized in that the first changeover switch and the second changeover switch are switched according to the type of the buried metal pipe.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP12782377A JPS5460958A (en) | 1977-10-24 | 1977-10-24 | Buried metal pipe detector |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP12782377A JPS5460958A (en) | 1977-10-24 | 1977-10-24 | Buried metal pipe detector |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5460958A JPS5460958A (en) | 1979-05-16 |
| JPS6161074B2 true JPS6161074B2 (en) | 1986-12-24 |
Family
ID=14969539
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP12782377A Granted JPS5460958A (en) | 1977-10-24 | 1977-10-24 | Buried metal pipe detector |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5460958A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0184779U (en) * | 1987-11-30 | 1989-06-06 |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP6437866B2 (en) * | 2015-03-31 | 2018-12-12 | 大阪瓦斯株式会社 | Method for setting transmission signal for detection of buried metal and detection device using this setting method |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS499388B1 (en) * | 1968-05-25 | 1974-03-04 |
-
1977
- 1977-10-24 JP JP12782377A patent/JPS5460958A/en active Granted
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0184779U (en) * | 1987-11-30 | 1989-06-06 |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5460958A (en) | 1979-05-16 |
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