JPS62828A - Detecting of fitting stress of double pipe - Google Patents
Detecting of fitting stress of double pipeInfo
- Publication number
- JPS62828A JPS62828A JP60139667A JP13966785A JPS62828A JP S62828 A JPS62828 A JP S62828A JP 60139667 A JP60139667 A JP 60139667A JP 13966785 A JP13966785 A JP 13966785A JP S62828 A JPS62828 A JP S62828A
- Authority
- JP
- Japan
- Prior art keywords
- double pipe
- signal
- fitting stress
- pipe
- double
- 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.)
- Pending
Links
Landscapes
- Investigating Or Analyzing Materials By The Use Of Ultrasonic Waves (AREA)
Abstract
Description
【発明の詳細な説明】
(産業上の利用分野)
本発明は、異鋼種の内外管より構成される二層構造の鋼
管(以下二重管という)の内外管はめあい応力を音響検
査方法により検知する方法に関するものである。[Detailed Description of the Invention] (Field of Industrial Application) The present invention detects the fitting stress of the inner and outer tubes of a two-layered steel tube (hereinafter referred to as a double tube) consisting of inner and outer tubes of different steels using an acoustic testing method. It's about how to do it.
(従来の技術)
一般に耐食を目的とした二重管製造方法は内外管側々の
製管ラインで造られ、異鋼種の内外管を焼きばめ等の方
法で接合するが、内外管接合時のはめあい応力が二重管
の品質に大きく影響する。(Prior art) In general, double pipe manufacturing methods for the purpose of corrosion resistance involve manufacturing lines for the inner and outer pipes, and the inner and outer pipes of different steels are joined by methods such as shrink fitting, but when joining the inner and outer pipes, The fitting stress greatly affects the quality of the double pipe.
従来二重管内外管はめあい応力検出法として超音波を内
外管肉厚方向に入射透過させ、内外管接合境界面での超
音波の散乱に基づく透過超音波の減衰によって良否を判
断する方法が非破壊検査便覧(4版)P、478により
知られている。Conventionally, the method of detecting the stress of fitting between the inner and outer tubes of a double tube is to transmit ultrasonic waves in the thickness direction of the inner and outer tubes, and to judge the quality of the fit based on the attenuation of the transmitted ultrasonic waves based on the scattering of the ultrasonic waves at the interface between the inner and outer tubes. It is known from Destructive Inspection Handbook (4th edition) P, 478.
このような従来法では、接合状態検査と共に内外管母材
部の欠陥探傷も同時に行う為、接合状態のみの識別が困
難であった。また内外管層間隙に油、水などが入ってい
る場合、接合良好部と誤認される。又送受信探触子の対
向位置、鋼管との接触を安定にしないと検査が困難であ
る等の問題が生じていた。In such a conventional method, it is difficult to identify only the bonded state because defect detection of the inner and outer tube base materials is performed at the same time as the bonded state inspection. Furthermore, if oil, water, etc. are present in the gap between the inner and outer tube layers, it may be mistaken as a good joint. In addition, there have been problems such as difficulty in inspection unless the transmitting and receiving probes are positioned opposite each other and their contact with the steel pipe is stabilized.
この状態を第2図によって詳細に説明する。This state will be explained in detail with reference to FIG.
第2図は、従来の超音波透過法による二重管はめあい応
力検知法の原理を示す。説明図において1は外管、2は
内管、3は内外管境界面、4は受信用探触子、5は送信
用探触子、6は接触媒質を示す。この状態で送信用探触
子5より超音波を発生させ、接触媒質6を介して内管2
に超音波を入射させる。入射された超音波は管内部を矢
印S方向に伝播し、外管1.接触媒質6を経由して受信
用探触子4で検出されるが、内外管境界面3の接合状態
により受信用探触子4で検出される超音波に減衰が生ず
る。FIG. 2 shows the principle of a double tube fitting stress detection method using a conventional ultrasonic transmission method. In the explanatory diagram, 1 is an outer tube, 2 is an inner tube, 3 is an interface between the inner and outer tubes, 4 is a receiving probe, 5 is a transmitting probe, and 6 is a couplant. In this state, ultrasonic waves are generated from the transmitting probe 5 and transmitted through the couplant 6 to the inner tube 2.
Inject ultrasonic waves into the The incident ultrasonic waves propagate inside the tube in the direction of arrow S, and the outer tube 1. Although the ultrasonic waves are detected by the receiving probe 4 via the couplant 6, attenuation occurs in the ultrasonic waves detected by the receiving probe 4 due to the bonded state of the inner and outer tube interfaces 3.
この透過超音波の強弱によって内外管はめあい応力を検
知している。しかし送受信探触子5の対向位置、内外管
への探触子接触条件、管内質欠陥及び内外管層間隙内の
媒体等が超音波透過量に影響するため内外管接合部の評
価が誤認される。The fitting stress between the inner and outer tubes is detected based on the strength of the transmitted ultrasound. However, the opposing positions of the transmitter/receiver probe 5, the contact conditions of the probes with the inner and outer tubes, defects in the inner tube quality, and the medium in the gap between the inner and outer tube layers affect the amount of ultrasound transmitted, so the evaluation of the inner and outer tube joints may be misdiagnosed. Ru.
(発明が解決しようとする問題点)
本発明は、二重管のはめあい応力を確実に安定して検知
することを目的とする。(Problems to be Solved by the Invention) An object of the present invention is to reliably and stably detect the fitting stress of a double pipe.
(問題点を解決するための手段)
この発明は被測定二重管を金槌などで叩いた際二重管よ
り発生する音響を周波数弁別することによりニ重管のは
めあい応力を検知する方法である。(Means for solving the problem) This invention is a method for detecting the fitting stress of a double pipe by frequency-discriminating the sound generated by the double pipe when the double pipe to be measured is struck with a hammer or the like. .
以下本発明の詳細を第1図により説明する。被測定用二
重管7をハンマー等の打撃装置8により衝撃を与えたと
き、被測定用二重管7から発生する音響信号をマイクロ
ホン等の音響信号検出器9によって検出し電気信号に変
換後、増幅器lOで検出信号を増幅する。増幅された電
気信号は特定音響周波数域の電気信号のみを通過させる
バンドパスフィルター等の周波数弁別器11によって二
重管内外管接合状態に応じて発生する特定音響周波数域
の信号を抽出し、合否選別器12で内外管接合良否を職
別選択させる。The details of the present invention will be explained below with reference to FIG. When the double pipe 7 to be measured is subjected to an impact with a striking device 8 such as a hammer, the acoustic signal generated from the double pipe 7 to be measured is detected by an acoustic signal detector 9 such as a microphone and converted into an electrical signal. , the detection signal is amplified by an amplifier lO. The amplified electrical signal is passed through a frequency discriminator 11 such as a band-pass filter that allows only electrical signals in a specific acoustic frequency range to pass through, which extracts signals in a specific acoustic frequency range that are generated depending on the state of the double-pipe-internal-interior-tube joint, and determines pass/fail. A sorter 12 selects whether the inner and outer tubes are joined properly or not according to job.
尚、打撃装置8に使用する打撃方法はエアーシリンダー
等を使用した機械的打撃、電磁超音波等の電磁気を使用
した打撃等いずれの方法でも良く、特に限定されない。Note that the striking method used in the striking device 8 is not particularly limited and may be any method such as mechanical striking using an air cylinder or the like, or striking using electromagnetism such as electromagnetic ultrasonic waves.
(作用)
打撃装置8により被測定用二重管7に衝撃を与え、該二
重管7から発生する音響を音響信号検出器9で検出し、
増幅器10で増幅し、二重管内外管接着状況によって発
生する特定音響周波数域の信号を周波数弁別器11で弁
別し、内外管はめあい応力を検出する。(Function) A shock is applied to the double pipe 7 to be measured by the impact device 8, and the sound generated from the double pipe 7 is detected by the acoustic signal detector 9.
The signal is amplified by an amplifier 10, and a signal in a specific acoustic frequency range generated depending on the adhesive condition between the inner and outer double tubes is discriminated by a frequency discriminator 11 to detect the fitting stress between the inner and outer tubes.
例えば、被測定二重管の内外管接着状況によって発生す
る音響周波数から特定音響周波数域を、高域、低域帯域
フィルター又はスペクトラムアナライブ等により周波数
弁別し、内外管はめあい応力を検知するものである。For example, a specific acoustic frequency range generated by the adhesion status of the inner and outer tubes of a double pipe to be measured is frequency-discriminated using high- and low-pass filters or a spectrum analyzer, and the fitting stress of the inner and outer tubes is detected. be.
はめあい応力を検出する具体的方法としては、例えば、
はめあい応力が所望の範囲のとき弁別可能な特定音響周
波数域を高域、低域帯域フィルターなどによって周波数
弁別し、該特定音響周波数域が弁別されたときをはめあ
い応力合格、弁別されなかったときを不合格とする。他
の方法としては、検出および増幅した音響信号をスペク
トラムアナライデーなどによって周波数解析し、予め求
めておいた音響周波数域とはめあい応力との関係からは
めあい応力を求める。As a specific method for detecting fitting stress, for example,
When the fitting stress is within a desired range, the specific acoustic frequency range that can be discriminated is frequency-discriminated using high and low band filters, and when the specific acoustic frequency range is discriminated, the fitting stress is passed, and when it is not discriminated, the fitting stress is passed. Fail. Another method is to frequency-analyze the detected and amplified acoustic signal using a spectrum analyzer or the like, and obtain the fitting stress from the relationship between the acoustic frequency range determined in advance and the fitting stress.
(実施例)
鋼管外径89.1φ簡、外管肉厚6.0 m、鋼種炭素
鋼、内管肉厚1.5籠、鋼種ステンレス鋼の被測定用二
重管2本について金属丸棒で打撃を与え発生した音響を
検出した。(Example) Metal round bars for two double pipes to be measured of steel pipe outer diameter 89.1φ, outer pipe wall thickness 6.0 m, steel type carbon steel, inner pipe wall thickness 1.5 cage, steel type stainless steel. The sound generated by the impact was detected.
一方周波数弁別器には所定のはめあい応力以上の被測定
用二重管より発生する周波数域2.70〜2、75 k
Hzを設定しておき、はめあい応力の合否を判定した結
果、&1の二重管は合格、扁2の二重管は不合格と判断
された。On the other hand, the frequency discriminator uses a frequency range of 2.70 to 2.75 k generated by the double pipe to be measured with a stress exceeding a predetermined fitting stress.
As a result of setting the Hz and determining the pass/fail of the fitting stress, it was determined that the double tube with &1 passed, and the double tube with flat 2 failed.
尚、各二重管のはめあい応力を測定した結果、扁lは2
0 ’q/lta” 、ム2は0ゆ/簡2であった。In addition, as a result of measuring the fitting stress of each double pipe, the flatness l is 2
0'q/lta'', mu2 was 0yu/simp2.
第1図は本発明による実施例を示すブロック図、第2図
は従来技術を示す概略断面図である。FIG. 1 is a block diagram showing an embodiment according to the present invention, and FIG. 2 is a schematic sectional view showing a conventional technique.
Claims (1)
た際発生する音響信号を周波数弁別することにより内外
管はめあい応力を検知することを特徴とする二重管はめ
あい応力検知方法。A method for detecting fitting stress in a double-pipe tube, characterized by detecting fitting stress in the inner and outer tubes by frequency-discriminating acoustic signals generated when a steel tube with a double-layer structure composed of inner and outer tubes of different steel types is struck.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP60139667A JPS62828A (en) | 1985-06-26 | 1985-06-26 | Detecting of fitting stress of double pipe |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP60139667A JPS62828A (en) | 1985-06-26 | 1985-06-26 | Detecting of fitting stress of double pipe |
Publications (1)
Publication Number | Publication Date |
---|---|
JPS62828A true JPS62828A (en) | 1987-01-06 |
Family
ID=15250611
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP60139667A Pending JPS62828A (en) | 1985-06-26 | 1985-06-26 | Detecting of fitting stress of double pipe |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS62828A (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US11570545B2 (en) | 2020-11-12 | 2023-01-31 | Kabushiki Kaisha Toshiba | Acoustic inspection apparatus and acoustic inspection method |
-
1985
- 1985-06-26 JP JP60139667A patent/JPS62828A/en active Pending
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US11570545B2 (en) | 2020-11-12 | 2023-01-31 | Kabushiki Kaisha Toshiba | Acoustic inspection apparatus and acoustic inspection method |
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