JP2002095088A - Magnetostrictive ultrasonic element and nondestructive inspection method using the same - Google Patents
Magnetostrictive ultrasonic element and nondestructive inspection method using the sameInfo
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- JP2002095088A JP2002095088A JP2000277401A JP2000277401A JP2002095088A JP 2002095088 A JP2002095088 A JP 2002095088A JP 2000277401 A JP2000277401 A JP 2000277401A JP 2000277401 A JP2000277401 A JP 2000277401A JP 2002095088 A JP2002095088 A JP 2002095088A
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- magnetostrictive
- ultrasonic
- magnetic field
- magnetostrictive ring
- ring body
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- Investigating Or Analyzing Materials By The Use Of Ultrasonic Waves (AREA)
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Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、超音波受発信素子
及びこれを用いた物体の非破壊検査方法に関し、更に詳
細には、磁歪効果を利用して超音波を発信・受信できる
新規な磁歪超音波素子並びにこれを用いて物体の内部異
常を検査する非破壊検査方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic wave transmitting / receiving element and a nondestructive inspection method of an object using the same, and more particularly, to a novel magnetostriction capable of transmitting and receiving ultrasonic waves utilizing a magnetostrictive effect. The present invention relates to an ultrasonic element and a nondestructive inspection method for inspecting an internal abnormality of an object using the same.
【０００２】[0002]
【従来の技術】近年、金属やコンクリート等からなる物
体の内部構造の劣化を診断する非破壊検査方法の一つと
して、超音波を利用した非破壊検査方法が知られてい
る。この超音波を発信又は受信する素子として圧電式超
音波センサーが一般に広く用いられている。2. Description of the Related Art In recent years, a non-destructive inspection method using ultrasonic waves has been known as one of non-destructive inspection methods for diagnosing deterioration of an internal structure of an object made of metal, concrete, or the like. A piezoelectric ultrasonic sensor is generally and widely used as an element for transmitting or receiving this ultrasonic wave.
【０００３】しかし、従前の圧電式センサーのように分
解能の比較的低い超音波センサーでは、被検査体内部の
欠陥や材質劣化の位置・大きさを高精度で能率よく検出
することができないという問題があった。特に、結晶粒
が粗大でその分布が不均一な金属からなる非検査体で
は、超音波の減衰やバックグラウンドノイズとしてのエ
コーが生じ、ＳＮ比が大幅に低下するからである。However, an ultrasonic sensor having a relatively low resolution, such as a conventional piezoelectric sensor, cannot detect a defect or a position or a size of material deterioration inside a test object with high accuracy and efficiency. was there. In particular, in a non-inspected body made of a metal having coarse crystal grains and non-uniform distribution, ultrasonic waves are attenuated and echoes as background noise occur, and the S / N ratio is greatly reduced.
【０００４】このような超音波センサーに係る問題を解
決する一案として、本発明者等は既に電磁超音波素子を
開発し、特願平１０−３６３４５３号及び特願平１０−
３６３４５４号としてこれを公開している。As a solution to the problem relating to such an ultrasonic sensor, the present inventors have already developed an electromagnetic ultrasonic element, and have disclosed in Japanese Patent Application Nos. 10-363453 and 10-103453.
This is published as No. 363454.
【０００５】この電磁超音波素子の発信方式は、金属中
に渦電流を発生させ、この渦電流と印加された磁場との
相互作用により金属中に振動ローレンツ力を生起させ、
この振動ローレンツ力により超音波を発生・伝播させる
ものである。また、この受信方式は、金属の超音波振動
により渦電流を発生させ、この渦電流による磁束変化を
高性能磁気ヘッドにより検出するものである。即ち、電
磁超音波方式は、金属中の渦電流を介して超音波を発信
・受信する方式であると言える。In the transmission method of this electromagnetic ultrasonic element, an eddy current is generated in a metal, and an oscillating Lorentz force is generated in the metal by an interaction between the eddy current and an applied magnetic field.
Ultrasonic waves are generated and propagated by the vibrating Lorentz force. In this receiving method, an eddy current is generated by ultrasonic vibration of a metal, and a change in magnetic flux due to the eddy current is detected by a high-performance magnetic head. That is, it can be said that the electromagnetic ultrasonic method is a method of transmitting and receiving ultrasonic waves via eddy currents in metal.
【０００６】[0006]
【発明が解決しようとする課題】このように、電磁超音
波素子は独創的な方式であり、各種の用途において実用
化するための研究開発が続行されており、特に非破壊検
査において有効であることが分かってきている。しか
し、前述したように、電磁超音波方式は被検査体が金属
に限定されており、コンクリート等のような非導電性の
非検査体には適用できないという制限がある。As described above, the electromagnetic ultrasonic element is an original system, and research and development for practical use in various applications are continued, and it is particularly effective in nondestructive inspection. I know that. However, as described above, the electromagnetic ultrasonic method has a limitation that the object to be inspected is limited to metal, and cannot be applied to a non-conductive non-inspection object such as concrete.
【０００７】一方、近年報道されているように、コンク
リート片が鉄道のトンネル内において剥落する事故が多
発している。この事件は、鉄道のトンネルに限った問題
ではなく、コンクリート構造物全体の問題である。トン
ネル、ビル、ダム、高速道路などのコンクリート構造物
はいずれ疲労破壊を生じる時期が必ず来る。この疲労破
壊を事前に検出して事故を防止する技術開発が緊急の課
題となっている。On the other hand, as reported in recent years, there have been many accidents in which concrete pieces fall off in railway tunnels. This incident is not limited to railway tunnels, but concerns the entire concrete structure. Concrete structures, such as tunnels, buildings, dams, and highways, will inevitably experience fatigue failure. The development of technology for detecting this fatigue failure in advance and preventing accidents has become an urgent issue.
【０００８】このように、コンクリート構造物の非破壊
検査を初めとして、電磁超音波方式では検出できない非
導電性物体の非破壊検査を精度良く実現できる新規技術
の出現が待たれている。従って、本発明は導電性被検査
体のみならず非導電性被検査体に対しても超音波を発信
・受信できる新規な超音波素子を提供することを目的と
し、同時にこの超音波素子を用いた非破壊検査方法を実
現することを目的とする。[0008] As described above, there is a need for a new technique capable of accurately performing a nondestructive inspection of a non-conductive object that cannot be detected by the electromagnetic ultrasonic method, including a nondestructive inspection of a concrete structure. Accordingly, an object of the present invention is to provide a novel ultrasonic element capable of transmitting and receiving ultrasonic waves not only to a conductive test object but also to a non-conductive test object. The purpose is to realize the non-destructive inspection method that was used.
【０００９】[0009]
【課題を解決するための手段】請求項１の発明は、磁歪
材料を環状に形成した磁歪リング体と、この磁歪リング
体の内部に直流バイアス磁場を形成するために磁歪リン
グ体に巻回されたバイアスコイルと、前記磁歪リング体
の超音波振動によりその磁歪効果を通して発生する変動
磁場を検出するために磁歪リング体に巻回された信号コ
イルから構成され、この信号コイルによる超音波受信感
度を前記直流バイアス磁場により調整し、前記磁歪リン
グ体を被検査体の表面に接触させて、被検査体表面の超
音波振動を磁歪リング体に伝達し、この磁歪リング体の
内部に生起した振動歪を磁歪効果により変動磁場に変換
し、この変動磁場を前記信号コイルにより検出して超音
波を受信することを特徴とする磁歪超音波素子である。According to a first aspect of the present invention, there is provided a magnetostrictive ring formed of a magnetostrictive material in an annular shape, and a magnetostrictive ring wound around the magnetostrictive ring to form a DC bias magnetic field inside the magnetostrictive ring. Bias coil, and a signal coil wound around the magnetostrictive ring body to detect a fluctuating magnetic field generated through the magnetostriction effect by the ultrasonic vibration of the magnetostrictive ring body. Adjusted by the DC bias magnetic field, the magnetostrictive ring is brought into contact with the surface of the device under test, and the ultrasonic vibration of the surface of the device under test is transmitted to the magnetostrictive ring, and the vibration distortion generated inside the magnetostrictive ring is performed. Is converted into a fluctuating magnetic field by a magnetostrictive effect, and the fluctuating magnetic field is detected by the signal coil to receive an ultrasonic wave.
【００１０】請求項２の発明は、磁歪材料を環状に形成
した磁歪リング体と、この磁歪リング体の内部に直流バ
イアス磁場を形成するために磁歪リング体に巻回された
バイアスコイルと、前記磁歪リング体に変動磁場を印加
して磁歪効果により磁歪リング体を超音波振動させるた
めに磁歪リング体に巻回された信号コイルから構成さ
れ、この信号コイルによる超音波発信感度を前記直流バ
イアス磁場により調整し、前記信号コイルに交流電流を
流して磁歪リング体の内部に変動磁場を生起し、この変
動磁場により磁歪効果を通して磁歪リング体に超音波振
動を生起させ、この磁歪リング体を被検査体表面に接触
させて超音波を発信させることを特徴とする磁歪超音波
素子である。According to a second aspect of the present invention, there is provided a magnetostrictive ring body formed of a magnetostrictive material in an annular shape, a bias coil wound around the magnetostrictive ring body to form a DC bias magnetic field inside the magnetostrictive ring body, It is composed of a signal coil wound around the magnetostrictive ring body to apply a fluctuating magnetic field to the magnetostrictive ring body and cause the magnetostrictive ring body to ultrasonically vibrate by the magnetostrictive effect. An AC current is passed through the signal coil to generate a fluctuating magnetic field inside the magnetostrictive ring, and the fluctuating magnetic field causes the magnetostrictive ring to generate ultrasonic vibrations through the magnetostrictive effect. A magnetostrictive ultrasonic element which emits ultrasonic waves by contacting a body surface.
【００１１】請求項３の発明は、前記磁歪リング体の平
均円周が受信又は発信する超音波の波長より短く設定さ
れる請求項１又は２記載の磁歪超音波素子である。The invention according to claim 3 is the magnetostrictive ultrasonic element according to claim 1 or 2, wherein the average circumference of the magnetostrictive ring is set shorter than the wavelength of the ultrasonic wave to be received or transmitted.
【００１２】請求項４の発明は、磁歪リング体の外周面
に固定手段を設け、この固定手段を被検査体の表面に係
合させて磁歪リング体を固定する請求項１又は２記載の
磁歪超音波素子である。According to a fourth aspect of the present invention, there is provided the magnetostrictive ring according to the first or second aspect, wherein a fixing means is provided on an outer peripheral surface of the magnetostrictive ring, and the fixing means is engaged with a surface of the test object to fix the magnetostrictive ring. It is an ultrasonic element.
【００１３】請求項５の発明は、磁歪リング体の内周部
に自由回転機構を設けて、磁歪リング体を走行する被検
査体の表面に接触させたときに磁歪リング体が転接する
ように配設された請求項１又は２記載の磁歪超音波素子
である。According to a fifth aspect of the present invention, a free rotation mechanism is provided at an inner peripheral portion of the magnetostrictive ring so that the magnetostrictive ring comes into rolling contact with the surface of a test object running on the magnetostrictive ring. 3. The magnetostrictive ultrasonic element according to claim 1, which is disposed.
【００１４】請求項６の発明は、超音波を被検査体の内
部に入射させ、被検査体の内部構造を反映して伝播する
超音波を被検査体の表面で受信して被検査体の内部異常
を検査する非破壊検査方法において、磁歪材料を環状に
形成した磁歪リング体を被検査体の表面に接触させて配
置し、この磁歪リング体にバイアスコイルを巻回して磁
歪リング体の内部に直流バイアス磁場を形成し、同時に
磁歪リング体に信号コイルを巻回し、この信号コイルに
よる超音波受信感度を前記直流バイアス磁場により調整
し、伝播してきた超音波により磁歪リング体を超音波振
動させ、この超音波振動により磁歪リング体の磁歪効果
を通して変動磁場を生起させ、この変動磁場を前記信号
コイルにより検出して超音波を受信し、この受信超音波
により被検査体の内部異常を検査することを特徴とする
磁歪超音波素子を用いた非破壊検査方法である。According to a sixth aspect of the present invention, an ultrasonic wave is made incident on the object to be inspected, and the ultrasonic wave propagating reflecting the internal structure of the object to be inspected is received on the surface of the object to be inspected. In a non-destructive inspection method for inspecting an internal abnormality, a magnetostrictive ring body formed of a magnetostrictive material in an annular shape is placed in contact with the surface of a device to be inspected, and a bias coil is wound around the magnetostrictive ring body to form an inner portion of the magnetostrictive ring body. A DC bias magnetic field is formed at the same time, a signal coil is wound around the magnetostrictive ring at the same time, the ultrasonic receiving sensitivity of the signal coil is adjusted by the DC bias magnetic field, and the magnetostrictive ring is ultrasonically vibrated by the transmitted ultrasonic waves. The ultrasonic vibration generates a fluctuating magnetic field through the magnetostrictive effect of the magnetostrictive ring body, detects the fluctuating magnetic field by the signal coil, receives an ultrasonic wave, and receives the ultrasonic wave by using the received ultrasonic wave. It is a non-destructive inspection method using a magnetostrictive ultrasonic device characterized by inspecting the parts abnormality.
【００１５】請求項７の発明は、超音波を被検査体の内
部に入射させ、被検査体の内部構造を反映して伝播する
超音波を被検査体の表面で受信して被検査体の内部異常
を検査する非破壊検査方法において、磁歪材料を環状に
形成した磁歪リング体を被検査体の表面に接触させて配
置し、この磁歪リング体にバイアスコイルを巻回して磁
歪リング体の内部に直流バイアス磁場を形成し、同時に
磁歪リング体に信号コイルを巻回し、この信号コイルに
よる超音波発信感度を前記直流バイアス磁場により調整
し、この信号コイルにより磁歪リング体の内部に超音波
領域の変動磁場を生起させ、この変動磁場により磁歪リ
ング体の磁歪効果を通して磁歪リング体を超音波振動さ
せ、この超音波振動により被検査体の内部に超音波を伝
播させて被検査体の内部異常を検査することを特徴とす
る磁歪超音波素子を用いた非破壊検査方法である。According to a seventh aspect of the present invention, an ultrasonic wave is made incident on the inside of the object to be inspected, and the ultrasonic wave propagating while reflecting the internal structure of the object to be inspected is received on the surface of the object to be inspected. In a non-destructive inspection method for inspecting an internal abnormality, a magnetostrictive ring body formed of a magnetostrictive material in an annular shape is placed in contact with the surface of a device to be inspected, and a bias coil is wound around the magnetostrictive ring body to form an inner portion of the magnetostrictive ring body. A DC bias magnetic field is formed at the same time, a signal coil is wound around the magnetostrictive ring at the same time, the ultrasonic transmission sensitivity of the signal coil is adjusted by the DC bias magnetic field, and the signal coil forms an ultrasonic region inside the magnetostrictive ring. A fluctuating magnetic field is generated, the fluctuating magnetic field causes the magnetostrictive ring body to vibrate ultrasonically through the magnetostrictive effect of the magnetostrictive ring body, and the ultrasonic vibration causes ultrasonic waves to propagate inside the object to be inspected. It is a non-destructive inspection method using a magnetostrictive ultrasonic element, characterized in that to inspect the internal abnormalities.
【００１６】[0016]
【発明の実施形態】本発明者等は、導電性と非導電性の
区別なしに、被検査体内部に超音波を発生・伝播させる
方式を鋭意研究した結果、機械的に超音波振動する物
体、即ち超音波振動体を被検査体に接触させ、この超音
波振動の機械的伝達によって被検査体内に超音波を導入
することが必要であると考えた。BEST MODE FOR CARRYING OUT THE INVENTION The present inventors have conducted intensive studies on a method of generating and propagating ultrasonic waves inside an object to be inspected without distinguishing between conductive and non-conductive, and as a result, an object which mechanically vibrates with ultrasonic waves. That is, it was considered necessary to bring the ultrasonic vibrator into contact with the object to be inspected and to introduce ultrasonic waves into the object to be inspected by mechanical transmission of the ultrasonic vibration.
【００１７】従来、この観点から開発されている超音波
振動体として圧電素子がある。圧電素子は、交流電圧を
印加されたとき、圧電材料が機械的に伸縮する性質を利
用したものである。しかし、前述したように、圧電材料
は精度上及びその他の理由から非破壊検査において種々
の欠点を有していることが分かっている。Conventionally, a piezoelectric element has been developed as an ultrasonic vibrator developed from this viewpoint. A piezoelectric element utilizes the property that a piezoelectric material mechanically expands and contracts when an AC voltage is applied. However, as noted above, piezoelectric materials have been found to have various drawbacks in non-destructive testing for accuracy and other reasons.
【００１８】そこで、本発明者等は他の原理に基づいて
超音波振動体を構成するために鋭意研究した結果、磁歪
効果を発現する材料、即ち磁歪材料が超音波振動体とし
て好適であることを見出すに到った。The inventors of the present invention have conducted intensive studies on forming an ultrasonic vibrator based on another principle, and have found that a material exhibiting a magnetostrictive effect, that is, a magnetostrictive material is suitable as an ultrasonic vibrator. I came to find.
【００１９】強磁性体は内部に無数の磁区を有し、この
磁区は自発磁化の方向に歪んでいることが分かってい
る。この強磁性体に外部磁場を加えると、外部磁場によ
って磁化の方向が回転し、ひずみの方向も大きさも変化
する。これが磁歪効果である。即ち、磁化によって強磁
性体が僅かに変形する現象が磁歪効果であり、逆に強磁
性体を変形させると、その変形の程度に従って磁束が変
化する可逆的な力学的磁気現象でもある。It has been found that a ferromagnetic material has an infinite number of magnetic domains inside, and these magnetic domains are distorted in the direction of spontaneous magnetization. When an external magnetic field is applied to the ferromagnetic material, the direction of magnetization is rotated by the external magnetic field, and both the direction and magnitude of the strain change. This is the magnetostrictive effect. That is, the phenomenon that the ferromagnetic material is slightly deformed by magnetization is a magnetostrictive effect, and conversely, when the ferromagnetic material is deformed, it is also a reversible mechanical magnetic phenomenon in which the magnetic flux changes according to the degree of the deformation.
【００２０】従って、本発明の要点は、磁歪材料で超音
波素子を構成し、この超音波素子を被検査体の表面に接
触させながら超音波の受発信を機械的伝達により行なう
点にある。つまり、超音波を発信するには、振動磁界を
印加して超音波素子を磁歪効果で振動させ、この超音波
振動を被検査体に機械的に伝達させればよい。また、超
音波を受信するには、被検査体の表面振動を超音波素子
に機械的に伝達させ、磁歪効果により発生する振動磁界
を超音波信号に変換すればよい。Therefore, the gist of the present invention is that the ultrasonic element is formed of a magnetostrictive material, and the ultrasonic element is transmitted and received by mechanical transmission while the ultrasonic element is in contact with the surface of the object to be inspected. That is, to transmit an ultrasonic wave, an oscillating magnetic field may be applied to vibrate the ultrasonic element by the magnetostrictive effect, and the ultrasonic vibration may be transmitted mechanically to the test object. To receive an ultrasonic wave, the surface vibration of the object to be inspected may be mechanically transmitted to the ultrasonic element, and the oscillating magnetic field generated by the magnetostrictive effect may be converted into an ultrasonic signal.
【００２１】本発明に用いることができる磁歪材料とし
ては、強磁性材料などの磁歪効果を発現する材料を云
い、例えば、金属、合金、金属含有化合物などからな
る。より具体的には、鉄、コバルト、ニッケル、それら
の合金、アルフェロ合金、フェライト、その他の公知の
磁歪材料を含む。The magnetostrictive material that can be used in the present invention is a material exhibiting a magnetostrictive effect, such as a ferromagnetic material, and includes, for example, a metal, an alloy, and a metal-containing compound. More specifically, it includes iron, cobalt, nickel, alloys thereof, alphero alloys, ferrites, and other known magnetostrictive materials.
【００２２】以下に、本発明に係る磁歪超音波素子及び
これを利用した非破壊検査方法の実施形態を図面に従っ
て詳細に説明する。図１は、本発明に係る磁歪超音波素
子の第１実施形態を示す正面図であり、図２は図１のＡ
−Ａ線断面図である。図１及び図２に示されるように、
磁歪超音波素子２は、磁歪材料を環状に形成した磁歪リ
ング体４と、この磁歪リング体４を直径方向に固定する
支持杆６と、この支持杆６を安定に立設させる支持板８
から構成されている。Hereinafter, embodiments of a magnetostrictive ultrasonic element according to the present invention and a nondestructive inspection method using the same will be described in detail with reference to the drawings. FIG. 1 is a front view showing a first embodiment of a magnetostrictive ultrasonic element according to the present invention, and FIG.
FIG. 4 is a cross-sectional view taken along a line A. As shown in FIGS. 1 and 2,
The magnetostrictive ultrasonic element 2 includes a magnetostrictive ring body 4 formed of a magnetostrictive material in an annular shape, a support rod 6 for fixing the magnetostrictive ring body 4 in the diameter direction, and a support plate 8 for stably standing the support rod 6.
It is composed of
【００２３】磁歪リング体４の頂部４ａは、支持杆６の
頂部６ａよりも段差ΔＨだけ上方に突出するように構成
される。これは、磁歪リング体頂部４ａを被検査体の表
面に接触させたときに支持杆頂部６ａがその表面に当接
しないようにして、超音波の発受信感度を良好に保持す
るためである。The top 4a of the magnetostrictive ring 4 is configured to protrude above the top 6a of the support rod 6 by a step ΔH. This is because when the top 4a of the magnetostrictive ring is brought into contact with the surface of the object to be inspected, the top 6a of the supporting rod does not come into contact with the surface, thereby maintaining good ultrasonic transmission / reception sensitivity.
【００２４】磁歪リング体４には、点線で表示したバイ
アスコイル１０と実線で表示した信号コイル１２が巻回
されている。バイアスコイル１０には直流電圧を印加し
て直流電流を流し、磁歪リング体４に直流バイアス磁場
を発生させる。この直流バイアス磁場の大きさは磁歪効
果の感度を良好に設定する様に調整される。A bias coil 10 indicated by a dotted line and a signal coil 12 indicated by a solid line are wound around the magnetostrictive ring 4. A DC voltage is applied to the bias coil 10 to flow a DC current, and a DC bias magnetic field is generated in the magnetostrictive ring 4. The magnitude of the DC bias magnetic field is adjusted so as to set the sensitivity of the magnetostrictive effect well.
【００２５】信号コイル１２は、超音波を発信する場合
には交流電流を流す印加コイル１２ａになり、超音波を
受信する場合には交流磁場を検出する検出コイル１２ｂ
になる。超音波発信では、信号コイル１２（つまり印加
コイル１２ａ）に交流電流を流すと、磁歪リング体４に
交流磁場が発生し、この交流磁場により磁歪リング体４
が磁歪効果により超音波振動する。一般に印加時の交流
電流は正弦波が用いられるが、矩形波、三角波、のこぎ
り波、その他の規則波でもよく、また不規則波でも構わ
ない。The signal coil 12 is an application coil 12a for passing an AC current when transmitting an ultrasonic wave, and a detection coil 12b for detecting an AC magnetic field when receiving an ultrasonic wave.
become. In ultrasonic transmission, when an alternating current is applied to the signal coil 12 (that is, the application coil 12a), an AC magnetic field is generated in the magnetostrictive ring 4, and the AC magnetic field generates an AC magnetic field.
Vibrates ultrasonically due to the magnetostrictive effect. Generally, a sine wave is used as the alternating current at the time of application, but a rectangular wave, a triangular wave, a sawtooth wave, other regular waves, or an irregular wave may be used.
【００２６】超音波受信では、磁歪リング体４が超音波
振動すると、その力学的振動が磁歪リング体４の磁歪効
果により交流に変換され、この交流磁場を信号コイル１
２（つまり検出コイル１２ｂ）により交流電流に変換す
る。被検査体表面の振動には規則振動のみならず不規則
振動もあり、検出される交流電流も規則電流、不規則電
流を含む。In the ultrasonic wave reception, when the magnetostrictive ring 4 is ultrasonically vibrated, the mechanical vibration is converted into an alternating current by the magnetostrictive effect of the magnetostrictive ring 4, and this alternating magnetic field is converted into a signal coil 1.
2 (that is, the detection coil 12b) converts the current into an alternating current. The vibration of the surface of the test object includes not only regular vibration but also irregular vibration, and the detected alternating current includes a regular current and an irregular current.
【００２７】図３は磁歪リング体４の平均円周の望まし
い条件をしめす模式図である。磁歪リング体４が超音波
振動すると、磁歪リング体は当然に変形する。このと
き、一点鎖線で示す磁歪リング体４の平均円周Ｄが超音
波の波長λよりも短いとき、即ちＤ＜λであれば、磁歪
リング体４の変形は局部的変形にとどまる。局部的変形
であれば発生する磁束も打ち消されること無く安定に生
じ、超音波の受信を確実に行なうことができる。FIG. 3 is a schematic view showing desirable conditions for the average circumference of the magnetostrictive ring 4. When the magnetostrictive ring 4 is ultrasonically vibrated, the magnetostrictive ring is naturally deformed. At this time, when the average circumference D of the magnetostrictive ring 4 indicated by a dashed line is shorter than the wavelength λ of the ultrasonic wave, that is, if D <λ, the deformation of the magnetostrictive ring 4 is limited to local deformation. In the case of local deformation, the generated magnetic flux is generated stably without being canceled out, and the ultrasonic wave can be received reliably.
【００２８】図４は磁歪リング体が対称変形した場合を
示す模式図である。平均円周Ｄが波長λより長い（Ｄ≧
λ）ときには、磁歪リング体４の円周方向に定常波が形
成される場合がある。詳細には、Ｄ＝ｍλ（ｍは自然
数）の条件が成立すると磁歪リング体４には定常波が形
成され、この定常波は左右対称変形になるため、左右に
発生した対称磁束が磁歪リング体４の内部で打ち消し合
い、合成信号磁束がゼロになる。図４には、左側変形に
よる左側磁束Ｂ1と右側変形による右側磁束Ｂ2が打ち消
し合う状況が示されており、この場合には合成磁束がゼ
ロになって超音波を受信できないことになる。FIG. 4 is a schematic diagram showing a case where the magnetostrictive ring body is symmetrically deformed. The average circumference D is longer than the wavelength λ (D ≧
λ) In some cases, a standing wave may be formed in the circumferential direction of the magnetostrictive ring 4. More specifically, when the condition of D = mλ (m is a natural number) is satisfied, a standing wave is formed in the magnetostrictive ring 4 and the standing wave is deformed symmetrically. The two cancel each other out and the composite signal magnetic flux becomes zero. FIG 4, there is shown a situation where the right flux B 2 by the left magnetic flux B 1 and right deformation by left deformation cancel, in this case is that the synthesized magnetic flux can not receive ultrasonic waves to zero.
【００２９】前述した定常波条件は超音波を受信する場
合に重要で、発信する場合には問題とはならない。印加
コイル１２ａに交流電流を流すと、磁歪リング体４には
交流磁場が発生するが、この交流磁場は全て同方向に発
生するため、磁歪リング体４の内部で打ち消しあうこと
が無いからである。The above-mentioned standing wave condition is important when receiving an ultrasonic wave, and does not cause a problem when transmitting. When an AC current is applied to the application coil 12a, an AC magnetic field is generated in the magnetostrictive ring 4, but the AC magnetic field is generated in the same direction, and therefore does not cancel each other inside the magnetostrictive ring 4. .
【００３０】図５は磁歪超音波素子による超音波受信試
験の概略構成図である。磁歪リング体４の頂部４ａを加
振板１４に接触させるように磁歪超音波素子２を配置
し、この加振板１４を加振装置１６により超音波領域の
振動数で強制振動させる。バイアスコイル１０には電流
制御回路１８から直流電流を流し、信号コイル１２（つ
まり検出コイル１２ａ）は信号検出回路２０に接続され
ている。FIG. 5 is a schematic configuration diagram of an ultrasonic reception test using a magnetostrictive ultrasonic element. The magnetostrictive ultrasonic element 2 is arranged so that the top 4a of the magnetostrictive ring 4 is brought into contact with the vibrating plate 14, and the vibrating plate 14 is forcibly vibrated by the vibrating device 16 at a frequency in the ultrasonic range. DC current flows from the current control circuit 18 to the bias coil 10, and the signal coil 12 (that is, the detection coil 12 a) is connected to the signal detection circuit 20.
【００３１】図６は磁歪リング体の内部に発生する磁束
のタイムチャートである。直流バイアス磁場Ｂ0 はバイ
アスコイル１０の直流電流により印加されたもので、信
号磁場ΔＢは磁歪リング体４が超音波振動してその磁歪
効果により内部に発生した信号磁場である。振動の状況
に応じて、信号磁場ΔＢは規則信号の場合もあるし、不
規則信号の場合もある。図６にはΔＢは不規則信号とし
て描かれている。直流バイアス磁場Ｂ0と信号磁場ΔＢ
の合成磁場Ｂが磁歪リング体４の中に生じている。FIG. 6 is a time chart of the magnetic flux generated inside the magnetostrictive ring. The DC bias magnetic field B 0 is applied by a DC current of the bias coil 10, and the signal magnetic field ΔB is a signal magnetic field generated inside by the magnetostrictive effect of the magnetostrictive ring body 4 by ultrasonic vibration. The signal magnetic field ΔB may be a regular signal or an irregular signal depending on the vibration situation. In FIG. 6, ΔB is drawn as an irregular signal. DC bias magnetic field B 0 and signal magnetic field ΔB
Is generated in the magnetostrictive ring 4.
【００３２】図７は信号コイルで検出される検出電流の
タイムチャートである。この振動成分である信号磁場Δ
Ｂが発生すると、電磁誘導により信号コイル１２に信号
電流ΔＩが誘起される。この信号電流ΔＩは信号検出回
路２０により検出され、ディスプレー（図示せず）に表
示される。FIG. 7 is a time chart of the detected current detected by the signal coil. The signal magnetic field Δ which is this oscillation component
When B occurs, a signal current ΔI is induced in the signal coil 12 by electromagnetic induction. This signal current ΔI is detected by the signal detection circuit 20 and displayed on a display (not shown).
【００３３】図８は直流バイアス磁場Ｂ0と信号磁場Δ
Ｂとの関係図である。磁歪リング体４が超音波振動する
と、磁歪効果により信号磁場ΔＢが発生することは前述
した通りである。この信号磁場ΔＢを精度良く検出する
ためには、信号磁場ΔＢの振幅は大きいほうが良い。つ
まり、信号磁場ΔＢの振幅の大きさは直流バイアス磁場
Ｂ0に依存し、この検出感度の関係が図８に示されてい
る。FIG. 8 shows a DC bias magnetic field B 0 and a signal magnetic field Δ.
FIG. As described above, when the magnetostrictive ring 4 is ultrasonically vibrated, the signal magnetic field ΔB is generated by the magnetostrictive effect. In order to accurately detect the signal magnetic field ΔB, it is better that the amplitude of the signal magnetic field ΔB is large. That is, the magnitude of the amplitude of the signal magnetic field ΔB depends on the DC bias magnetic field B 0, and the relationship between the detection sensitivities is shown in FIG.
【００３４】この関係は磁歪材料の物性に依存し、図８
はその一般的傾向を示すに過ぎない。磁歪超音波素子２
の検出感度を高めるためには、直流バイアス磁場Ｂ0の
大きさを調整しながら振動磁場ΔＢが最大になる条件を
見出すことが重要になる。This relationship depends on the physical properties of the magnetostrictive material.
Shows only its general tendency. Magnetostrictive ultrasonic element 2
In order to enhance the detection sensitivity, it is important to find a condition that maximizes the oscillating magnetic field ΔB while adjusting the magnitude of the DC bias magnetic field B 0 .
【００３５】図９は磁歪超音波素子を超音波受信子とし
て用いた受信構成図である。被検査体２４の表面には超
音波発信器２２と磁歪超音波素子２が所定距離Ｌだけ離
間して配置されている。超音波発信子２２は圧電式発信
子又は電磁超音波発信子から構成される。圧電式発信子
は被検査体２４が導電体又は非導電体のいずれに対して
も作用するが、電磁超音波発信子は導電体の場合にだけ
作用する。前記超音波発信子２２には送信装置２６が接
続されている。FIG. 9 is a diagram showing a receiving configuration using a magnetostrictive ultrasonic element as an ultrasonic receiver. The ultrasonic transmitter 22 and the magnetostrictive ultrasonic element 2 are arranged on the surface of the inspection object 24 with a predetermined distance L therebetween. The ultrasonic transmitter 22 is composed of a piezoelectric transmitter or an electromagnetic ultrasonic transmitter. The piezoelectric oscillator operates on either the conductor or the non-conductor of the inspection object 24, while the electromagnetic ultrasonic oscillator operates only on the conductor. A transmitting device 26 is connected to the ultrasonic transmitter 22.
【００３６】一方、磁歪超音波素子２にはプリアンプ２
８、受信装置３０及び受信表示装置３２が接続されてい
る。送信装置２６により超音波発信子２２を超音波振動
させると、被検査体２４に超音波振動が矢印ａ方向に伝
播する。この超音波振動を磁歪超音波素子２で検出し、
プリアンプ２８で前置増幅した後、受信装置３０で受信
する。この信号波形は受信表示装置３２で表示される。On the other hand, the magnetostrictive ultrasonic element 2 has a preamplifier 2
8, the receiving device 30 and the receiving display device 32 are connected. When the transmitting device 26 causes the ultrasonic transmitter 22 to ultrasonically vibrate, the ultrasonic vibration propagates to the subject 24 in the direction of the arrow a. This ultrasonic vibration is detected by the magnetostrictive ultrasonic element 2,
After pre-amplification is performed by the preamplifier 28, the signal is received by the receiving device 30. This signal waveform is displayed on the reception display device 32.
【００３７】図１０は受信表示装置による受信超音波の
波形図である。上側波形Ｗ１は離間距離ＬがＬ＝４０ｍ
ｍの場合を示し、下側波形Ｗ２はＬ＝７０ｍｍの場合に
対応している。上側波形Ｗ１の伝達時間τはτ＝１７
（μｓ）であり、下側波形Ｗ２ではτ＝２９(μｓ)であ
る。音速ＶをＶ＝Ｌ？τで計算すると、Ｗ１からはＶ＝
２．４（ｋｍ/ｓ）が得られ、Ｗ２からもＶ＝２．４
（ｋｍ/ｓ）が得られる。従って、両者から同一の音速
が得られたので、本発明に係る磁歪超音波素子が超音波
受信子として精密測定に利用できることが明らかとなっ
た。FIG. 10 is a waveform diagram of an ultrasonic wave received by the reception display device. The upper waveform W1 has a separation distance L of L = 40 m.
m, and the lower waveform W2 corresponds to the case where L = 70 mm. The transmission time τ of the upper waveform W1 is τ = 17
(Μs), and τ = 29 (μs) for the lower waveform W2. V = L? Calculating with τ, from W1, V =
2.4 (km / s) was obtained, and V = 2.4 from W2.
(Km / s) is obtained. Therefore, since the same sound velocity was obtained from both, it became clear that the magnetostrictive ultrasonic element according to the present invention can be used for precision measurement as an ultrasonic receiver.
【００３８】図１１は磁歪超音波素子を超音波発信子と
して用いた発信構成図である。磁歪超音波素子２に送信
装置２６を接続し、磁歪超音波素子２を超音波振動させ
ながら被検査体２４の表面に接触させる。超音波は被検
査体２４の内部を矢印ｂ方向に伝播し、超音波受信子２
３により検出される。超音波受信子２３は圧電式受信子
又は電磁超音波受信子により構成される。FIG. 11 is a transmission configuration diagram using a magnetostrictive ultrasonic element as an ultrasonic transmitter. The transmitting device 26 is connected to the magnetostrictive ultrasonic element 2, and the magnetostrictive ultrasonic element 2 is brought into contact with the surface of the inspection object 24 while ultrasonically vibrating. The ultrasonic wave propagates in the direction of the arrow b inside the object 24 to be inspected, and the ultrasonic receiver 2
3 is detected. The ultrasonic receiver 23 is constituted by a piezoelectric receiver or an electromagnetic ultrasonic receiver.
【００３９】超音波受信子２３はプリアンプ２８、受信
装置３０及び受信表示装置３２に接続される。受信表示
装置３２により得られた受信波形は図示しないが、図１
０と同様に、精度の良い信号波形が得られた。超音波の
伝播速度の測定に関しても、満足のゆく結果が得られ
た。従って、本発明に係る磁歪超音波素子は超音波発信
子としても用いることが明らかになった。The ultrasonic receiver 23 is connected to a preamplifier 28, a receiving device 30, and a receiving and displaying device 32. Although the received waveform obtained by the reception display device 32 is not shown, FIG.
As in the case of 0, a highly accurate signal waveform was obtained. Satisfactory results were obtained for the measurement of the propagation speed of the ultrasonic wave. Therefore, it has been clarified that the magnetostrictive ultrasonic element according to the present invention is also used as an ultrasonic transmitter.
【００４０】図１２は本発明に係る磁歪超音波素子の第
２実施形態を示す正面図である。図１と同一部分には同
一符号を打ってその説明を省略し、異なる部分を説明す
る。この実施形態の特徴は、磁歪リング体４の頂部４ａ
付近に固定手段５が形成されている点である。この固定
手段５は被検査体２４の表面に係合し、磁歪リング体４
が超音波振動しても位置ずれを起こさない。従って、超
音波発信子と超音波受信子の離間距離が変化せず、超音
波測定の精度を向上させることができる。FIG. 12 is a front view showing a second embodiment of the magnetostrictive ultrasonic element according to the present invention. The same parts as those in FIG. 1 are denoted by the same reference numerals, and the description thereof will be omitted. The feature of this embodiment is that the top 4a of the magnetostrictive ring 4
The point is that the fixing means 5 is formed in the vicinity. The fixing means 5 engages with the surface of the inspection object 24 and
Does not shift even if ultrasonic vibration occurs. Therefore, the distance between the ultrasonic transmitter and the ultrasonic receiver does not change, and the accuracy of ultrasonic measurement can be improved.
【００４１】固定手段５の具体的構造は、例えば表面に
突刺する突起であったり、表面に固着する粘着物質であ
ったり、係合用ファスナーなど公知の構造を利用でき
る。As the specific structure of the fixing means 5, a known structure such as a protrusion sticking to the surface, an adhesive substance fixed to the surface, or a fastener for engagement can be used.
【００４２】図１３は本発明に係る磁歪超音波素子の第
３実施形態を示す変形正面図である。図１と同一部分に
は同一符号を打ってその説明を省略し、異なる部分を説
明する。磁歪リング体４の中心部には自由回転機構７が
設けられており、被検査体２４が矢印ｃ方向に走行する
ときに、磁歪リング体４が被検査体２４の表面に矢印ｄ
方向に転接し、この転接状態のまま超音波測定を測定す
るものである。自由回転機構７の具体的構造は、例えば
ベアリングのように公知の機構が利用できる。FIG. 13 is a modified front view showing a third embodiment of the magnetostrictive ultrasonic element according to the present invention. The same parts as those in FIG. 1 are denoted by the same reference numerals, and the description thereof will be omitted. A free rotation mechanism 7 is provided at the center of the magnetostrictive ring 4, and when the test object 24 travels in the direction of arrow c, the magnetostrictive ring 4 moves on the surface of the test object 24 with an arrow d.
In this direction, the ultrasonic measurement is performed while the rolled state is maintained. As a specific structure of the free rotation mechanism 7, a known mechanism such as a bearing can be used.
【００４３】図１４は磁歪超音波素子を用いた被検査体
の非破壊検査方法の概略説明図である。この実施形態で
は、超音波の発信用と受信用に本発明に係る磁歪超音波
素子を用いる。即ち、被検査体２４の表面に発信用磁歪
超音波素子２ａを固定手段５で固定配置し、これとは別
に受信用磁歪超音波素子２ｂを可動自在に配置する。FIG. 14 is a schematic explanatory view of a non-destructive inspection method for an object to be inspected using a magnetostrictive ultrasonic element. In this embodiment, the magnetostrictive ultrasonic element according to the present invention is used for transmitting and receiving ultrasonic waves. That is, the transmitting magnetostrictive ultrasonic element 2a is fixedly arranged on the surface of the inspection object 24 by the fixing means 5, and separately from the receiving magnetostrictive ultrasonic element 2b is movably arranged.
【００４４】被検査体２４の中に異常部２４ａがあり、
この位置を探査するために発信用磁歪超音波素子２ａか
ら超音波を被検査体２４の内部に入射させる。被検査体
２４の材質が決まれば超音波の伝播速度は決まる。受信
用磁歪超音波素子２ｂが受信する超音波の伝達経路は主
に直達経路Ｐ1、異常部反射経路Ｐ2及び裏面反射経路Ｐ
３の３経路である。There is an abnormal part 24a in the inspection object 24,
In order to search this position, an ultrasonic wave is made incident from the transmitting magnetostrictive ultrasonic element 2a into the object 24 to be inspected. If the material of the inspection object 24 is determined, the propagation speed of the ultrasonic wave is determined. Ultrasonic transmission passage receiving magnetostrictive ultrasonic element 2b receives mainly Jikatachi path P 1, the abnormal portion reflected path P 2 and back reflection path P
3 is three paths.
【００４５】発信用磁歪超音波素子２ａと受信用磁歪超
音波素子２ｂの離間距離並びに被検査体２４の厚さは決
まっているから、直達経路Ｐ１と裏面反射経路Ｐ３を通
る超音波の受信時間τ1、τ3は事前に計算できる。この
受信時間とは発信から受信までの超音波の経過時間であ
る。異常部２４ａが存在すると異常部反射経路Ｐ２があ
るはずであり、この受信時間τ2はτ1＜τ2＜τ3の関係
を満足する。Since the distance between the transmitting magnetostrictive ultrasonic element 2a and the receiving magnetostrictive ultrasonic element 2b and the thickness of the test object 24 are determined, the ultrasonic wave receiving time passing through the direct path P1 and the back reflection path P3 is determined. τ 1 and τ 3 can be calculated in advance. The reception time is the elapsed time of the ultrasonic wave from transmission to reception. If the abnormal part 24a exists, there should be an abnormal part reflection path P2, and the reception time τ 2 satisfies the relationship of τ 1 <τ 2 <τ 3 .
【００４６】受信用磁歪超音波素子２ｂの位置を移動さ
せながら、τ1とτ3の間に位置する異常部反射超音波を
探査する。もしτ1＜τ2＜τ3を満足するτ2が発見でき
れば、被検査体２４の内部に異常部２４ａが存在するこ
とを意味する。このようにして、被検査体２４の非破壊
検査を行なう。An abnormal part reflected ultrasonic wave located between τ 1 and τ 3 is searched while moving the position of the receiving magnetostrictive ultrasonic element 2b. If discovered tau 2 satisfying take τ 1 <τ 2 <τ 3 If means that there is an abnormal portion 24a within the test subject 24. Thus, the non-destructive inspection of the inspection object 24 is performed.
【００４７】本発明は上記実施形態に限定されるもので
はなく、本発明の技術的思想を逸脱しない範囲における
種々の変形例や設計変更などをその技術的範囲内に包含
するものである。The present invention is not limited to the above-described embodiment, but includes various modifications and design changes without departing from the technical idea of the present invention.
【００４８】[0048]
【発明の効果】請求項１の発明によれば、新規かつ独創
的な受信用磁歪超音波素子を実現でき、直流バイアス磁
場を調整しながら磁歪リング体を被検査体の表面に接触
させるだけで、被検査体の超音波振動を磁歪リング体の
振動磁場又は振動電流として高感度に検出することがで
きる。According to the first aspect of the present invention, a novel and original magnetostrictive ultrasonic element for reception can be realized, and the magnetostrictive ring can be brought into contact with the surface of the test object while adjusting the DC bias magnetic field. The ultrasonic vibration of the test object can be detected with high sensitivity as the oscillating magnetic field or oscillating current of the magnetostrictive ring.
【００４９】請求項２の発明によれば、新規かつ独創的
な発信用磁歪超音波素子を実現でき、直流バイアス磁場
により発信感度を良好に調整しながら、信号コイルに交
流電流を流して磁歪リング体を超音波振動させ、この磁
歪リング体を被検査体に接触させるだけで超音波を発信
することができる。According to the second aspect of the present invention, a novel and original magnetostrictive ultrasonic element for transmission can be realized, and an AC current is applied to the signal coil to control the magnetostrictive ring while the transmission sensitivity is favorably adjusted by the DC bias magnetic field. Ultrasonic waves can be transmitted simply by vibrating the body with ultrasonic waves and bringing the magnetostrictive ring body into contact with the test object.
【００５０】請求項３の発明によれば、磁歪リング体の
平均円周を超音波の波長より短く設定するだけで、磁歪
リング体に定常波を形成させないようにし、磁歪リング
体に局部的な振動を生起させて超音波の受信または発信
を効率的に行なわせることができる磁歪超音波素子を実
現できる。According to the third aspect of the present invention, only by setting the average circumference of the magnetostrictive ring to be shorter than the wavelength of the ultrasonic wave, the stationary wave is prevented from being formed in the magnetostrictive ring, and the local vibration is applied to the magnetostrictive ring. And a magnetostrictive ultrasonic element capable of efficiently receiving or transmitting ultrasonic waves can be realized.
【００５１】請求項４の発明によれば、磁歪リング体の
外周面に固定手段を設けているから、被検査体の表面に
磁歪リング体を位置ずれなく固定することができ、この
結果超音波の発信点または受信点を一点に確定できるか
ら、位置精度の高い磁歪超音波素子を実現できる。According to the fourth aspect of the present invention, since the fixing means is provided on the outer peripheral surface of the magnetostrictive ring, the magnetostrictive ring can be fixed on the surface of the test object without displacement, and as a result, the ultrasonic wave Can be determined as one point, and a magnetostrictive ultrasonic element with high positional accuracy can be realized.
【００５２】請求項５の発明によれば、磁歪リング体の
内周部に自由回転機構を設けているから、磁歪リング体
を走行する被検査体の表面に転接させることができ、走
行する被検査体に適用できる磁歪超音波素子を実現でき
る。According to the fifth aspect of the present invention, since the free rotating mechanism is provided on the inner peripheral portion of the magnetostrictive ring, the magnetostrictive ring can be brought into rolling contact with the surface of the object to be inspected and travels. A magnetostrictive ultrasonic element applicable to an object to be inspected can be realized.
【００５３】請求項６の発明によれば、磁歪リング体を
被検査体の表面に接触させ、直流バイアス磁場により受
信感度を良好に調整して、被検査体の内部を伝播してき
た超音波を受信し、受信超音波信号の伝播異常から被検
査体内部の異常部を効率的に検出することができるAccording to the sixth aspect of the present invention, the magnetostrictive ring is brought into contact with the surface of the object to be inspected, the reception sensitivity is adjusted favorably by the DC bias magnetic field, and the ultrasonic wave propagating inside the object to be inspected is transmitted. It is possible to efficiently detect an abnormal part inside a test object from a propagation abnormality of a received and received ultrasonic signal.
【００５４】請求項７の発明によれば、磁歪リング体を
被検査体の表面に接触させ、直流バイアス磁場により発
信感度を良好に調整して、被検査体の内部に超音波を発
信させ、この超音波を被検査体の内部に伝播させて被検
査体の内部異常を効率的に検出することができるAccording to the seventh aspect of the present invention, the magnetostrictive ring is brought into contact with the surface of the test object, the transmission sensitivity is satisfactorily adjusted by the DC bias magnetic field, and the ultrasonic wave is transmitted inside the test object. This ultrasonic wave is propagated inside the object to be inspected, so that an abnormality inside the object to be inspected can be efficiently detected.
【図１】本発明に係る磁歪超音波素子の第１実施形態を
示す正面図である。FIG. 1 is a front view showing a first embodiment of a magnetostrictive ultrasonic element according to the present invention.
【図２】図１のＡ−Ａ線断面図である。FIG. 2 is a sectional view taken along line AA of FIG.
【図３】磁歪リング体の平均円周の望ましい条件をしめ
す模式図である。FIG. 3 is a schematic diagram showing desirable conditions for an average circumference of a magnetostrictive ring body.
【図４】磁歪リング体が対称変形した場合を示す模式図
である。FIG. 4 is a schematic diagram showing a case where a magnetostrictive ring body is symmetrically deformed.
【図５】磁歪超音波素子による超音波受信試験の概略構
成図である。FIG. 5 is a schematic configuration diagram of an ultrasonic reception test using a magnetostrictive ultrasonic element.
【図６】磁歪リング体の内部に発生する磁束のタイムチ
ャートである。FIG. 6 is a time chart of a magnetic flux generated inside the magnetostrictive ring.
【図７】信号コイルで検出される検出電流のタイムチャ
ートである。FIG. 7 is a time chart of a detection current detected by a signal coil.
【図８】直流バイアス磁場Ｂ0と信号磁場ΔＢとの関係
図である。FIG. 8 is a relationship diagram between a DC bias magnetic field B 0 and a signal magnetic field ΔB.
【図９】磁歪超音波素子を超音波受信子として用いた受
信構成図である。FIG. 9 is a reception configuration diagram using a magnetostrictive ultrasonic element as an ultrasonic receiver.
【図１０】受信表示装置による受信超音波の波形図であ
る。FIG. 10 is a waveform diagram of ultrasonic waves received by the reception display device.
【図１１】磁歪超音波素子を超音波発信子として用いた
発信構成図である。FIG. 11 is a transmission configuration diagram using a magnetostrictive ultrasonic element as an ultrasonic transmitter.
【図１２】本発明に係る磁歪超音波素子の第２実施形態
を示す正面図である。FIG. 12 is a front view showing a second embodiment of the magnetostrictive ultrasonic element according to the present invention.
【図１３】本発明に係る磁歪超音波素子の第３実施形態
を示す変形正面図である。FIG. 13 is a modified front view showing a third embodiment of the magnetostrictive ultrasonic element according to the present invention.
【図１４】磁歪超音波素子を用いた被検査体の非破壊検
査方法の概略説明図である。FIG. 14 is a schematic explanatory view of a non-destructive inspection method of an inspection object using a magnetostrictive ultrasonic element.
２は磁歪超音波素子、２ａは発信用磁歪超音波素子、２
ｂは受信用磁歪超音波素子、４は磁歪リング体、４ａは
磁歪リング体頂部、５は固定手段、６は支持杆、７は自
由回転機構、６ａは支持杆頂部、８は支持板、１０はバ
イアスコイル、１２は信号コイル、１２ａは印加コイ
ル、１２ｂは検出コイル、１４は加振板、１６は加振装
置、１８は電流制御回路、２０は信号検出回路、２２は
超音波発信子、２３は超音波受信子、２４は被検査体、
２４ａは異常部、２６は送信装置、２８はプリアンプ、
３０は受信装置、３２は受信表示装置、Ｂ1は左側磁
束、Ｂ2は右側磁束、Ｄは平均円周、Ｂ0は直流バイアス
磁場、ΔＢは変動磁場、ΔＩは検出電流、Ｐ1は直達経
路、Ｐ2は異常部反射経路、Ｐ3は裏面反射経路、Ｗ1は
上側波形、Ｗ2は下側波形。2 is a magnetostrictive ultrasonic element, 2a is a transmitting magnetostrictive ultrasonic element, 2
b is a magnetostrictive ultrasonic element for reception, 4 is a magnetostrictive ring, 4a is a top of the magnetostrictive ring, 5 is a fixing means, 6 is a support rod, 7 is a free rotation mechanism, 6a is a top of a support rod, 8 is a support plate, 8 is a support plate, Is a bias coil, 12 is a signal coil, 12a is an application coil, 12b is a detection coil, 14 is a vibration plate, 16 is a vibration device, 18 is a current control circuit, 20 is a signal detection circuit, 22 is an ultrasonic oscillator, 23 is an ultrasonic receiver, 24 is a test object,
24a is an abnormal part, 26 is a transmitting device, 28 is a preamplifier,
30 receiving apparatus, 32 receiving the display device, B 1 is the left flux, B 2 right flux, D is the average circumference, B 0 is the DC bias magnetic field, .DELTA.B the varying magnetic field, [Delta] I is the detection current, P 1 is the direct path, P 2 is abnormal portion reflected path, P 3 is the back surface reflected path, W 1 is the upper waveform, W 2 is lower waveform.
───────────────────────────────────────────────────── フロントページの続き Ｆターム(参考） 2F068 AA48 BB26 CC11 FF12 FF16 GG02 KK13 2G047 AA10 BC09 CA02 EA10 5D019 AA21 CC03 CC06 CC13 FF03 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2F068 AA48 BB26 CC11 FF12 FF16 GG02 KK13 2G047 AA10 BC09 CA02 EA10 5D019 AA21 CC03 CC06 CC13 CC13 FF03
Claims (7)
４と、この磁歪リング体４の内部に直流バイアス磁場Ｂ
0を形成するために磁歪リング体に巻回されたバイアス
コイル１０と、前記磁歪リング体４の超音波振動により
その磁歪効果を通して発生する変動磁場ΔＢを検出する
ために磁歪リング体４に巻回された信号コイル１２から
構成され、この信号コイル１２による超音波受信感度を
前記直流バイアス磁場Ｂ0により調整し、前記磁歪リング
体４を被検査体２４の表面に接触させて、被検査体表面
の超音波振動を磁歪リング体４に伝達し、この磁歪リン
グ体４の内部に生起した振動歪を磁歪効果により変動磁
場ΔＢに変換し、この変動磁場を前記信号コイル１２に
より検出して超音波を受信することを特徴とする磁歪超
音波素子。1. A magnetostrictive ring 4 formed of a magnetostrictive material in an annular shape, and a DC bias magnetic field B
A bias coil 10 wound around the magnetostrictive ring body to form a zero , and a winding around the magnetostrictive ring body 4 to detect a fluctuating magnetic field ΔB generated through the magnetostrictive effect of the magnetostrictive ring body 4 by ultrasonic vibration. The signal receiving coil 24 is configured to adjust the ultrasonic receiving sensitivity of the signal coil 12 by the DC bias magnetic field B 0, and to bring the magnetostrictive ring 4 into contact with the surface of the device 24 to be inspected. Is transmitted to the magnetostrictive ring body 4, the vibration strain generated inside the magnetostrictive ring body 4 is converted into a fluctuating magnetic field ΔB by the magnetostriction effect, and the fluctuating magnetic field is detected by the signal coil 12 to generate an ultrasonic wave. A magnetostrictive ultrasonic element, wherein
４と、この磁歪リング体４の内部に直流バイアス磁場Ｂ
0を形成するために磁歪リング体４に巻回されたバイア
スコイル１０と、前記磁歪リング体４に変動磁場ΔＢを
印加して磁歪効果により磁歪リング体４を超音波振動さ
せるために磁歪リング体４に巻回された信号コイル１２
から構成され、この信号コイル１２による超音波発信感
度を前記直流バイアス磁場Ｂ0により調整し、前記信号コ
イル１２に交流電流を流して磁歪リング体４の内部に変
動磁場ΔＢを生起し、この変動磁場ΔＢにより磁歪効果
を通して磁歪リング体４に超音波振動を生起させ、この
磁歪リング体４を被検査体表面に接触させて超音波を発
信させることを特徴とする磁歪超音波素子。2. A ring-shaped magnetostrictive body 4 made of a magnetostrictive material, and a DC bias magnetic field B
A bias coil 10 wound around the magnetostrictive ring 4 to form 0 , and a magnetostrictive ring for applying a fluctuating magnetic field ΔB to the magnetostrictive ring 4 and ultrasonically vibrating the magnetostrictive ring 4 by the magnetostrictive effect. Signal coil 12 wound around 4
The ultrasonic transmission sensitivity of the signal coil 12 is adjusted by the DC bias magnetic field B 0, and an alternating current is applied to the signal coil 12 to generate a fluctuating magnetic field ΔB inside the magnetostrictive ring body 4. A magnetostrictive ultrasonic element characterized in that an ultrasonic vibration is generated in the magnetostrictive ring body 4 through the magnetostriction effect by the magnetic field ΔB, and the magnetostrictive ring body 4 is brought into contact with the surface of the test object to transmit ultrasonic waves.
又は発信する超音波の波長より短く設定される請求項１
又は２記載の磁歪超音波素子。3. An average circumference D of the magnetostrictive ring 4 is set shorter than a wavelength of an ultrasonic wave to be received or transmitted.
Or the magnetostrictive ultrasonic element according to 2.
設け、この固定手段５を被検査体２４の表面に係合させ
て磁歪リング体４を固定する請求項１又は２記載の磁歪
超音波素子。4. The magnetostrictive device according to claim 1, wherein a fixing means is provided on an outer peripheral surface of the magnetostrictive ring body, and the fixing means is engaged with a surface of the inspection object to fix the magnetostrictive ring body. Ultrasonic element.
７を設けて、磁歪リング体４を走行する被検査体２４の
表面に接触させたときに磁歪リング体４が転接するよう
に配設された請求項１又は２記載の磁歪超音波素子。5. A free rotation mechanism 7 is provided on the inner peripheral portion of the magnetostrictive ring 4 so that the magnetostrictive ring 4 rolls when it comes into contact with the surface of the test object 24 running on the magnetostrictive ring 4. 3. The magnetostrictive ultrasonic element according to claim 1, which is disposed.
せ、被検査体２４の内部構造を反映して伝播する超音波
を被検査体の表面で受信して被検査体２４の内部異常を
検査する非破壊検査方法において、磁歪材料を環状に形
成した磁歪リング体４を被検査体２４の表面に接触させ
て配置し、この磁歪リング体４にバイアスコイル１０を
巻回して磁歪リング体４の内部に直流バイアス磁場Ｂ0
を形成し、同時に磁歪リング体４に信号コイル１２を巻
回し、この信号コイル１２による超音波受信感度を前記
直流バイアス磁場Ｂ0により調整し、伝播してきた超音
波により磁歪リング体４を超音波振動させ、この超音波
振動により磁歪リング体４の磁歪効果を通して変動磁場
ΔＢを生起させ、この変動磁場ΔＢを前記信号コイル１
２により検出して超音波を受信し、この受信超音波によ
り被検査体の内部異常を検査することを特徴とする磁歪
超音波素子を用いた非破壊検査方法。6. An ultrasonic wave is made incident on the inside of the object to be inspected 24, and an ultrasonic wave propagating reflecting the internal structure of the object to be inspected 24 is received on the surface of the object to be inspected, and an internal abnormality of the object to be inspected 24 is received. In the non-destructive inspection method for inspecting the magnetostrictive ring, a magnetostrictive ring 4 formed of a magnetostrictive material in an annular shape is placed in contact with the surface of the test object 24, and a bias coil 10 is wound around the magnetostrictive ring 4 to 4, a DC bias magnetic field B 0
Is formed, and at the same time, the signal coil 12 is wound around the magnetostrictive ring body 4, the sensitivity of the ultrasonic wave reception by the signal coil 12 is adjusted by the DC bias magnetic field B 0 , and the magnetostrictive ring body 4 is ultrasonically propagated by the propagated ultrasonic waves. And vibrates to generate a fluctuating magnetic field ΔB through the magnetostrictive effect of the magnetostrictive ring body 4 due to the ultrasonic vibration.
2. A non-destructive inspection method using a magnetostrictive ultrasonic element, wherein the ultrasonic wave is detected and received by the method 2, and an internal abnormality of the inspection object is inspected by the received ultrasonic wave.
せ、被検査体２４の内部構造を反映して伝播する超音波
を被検査体の表面で受信して被検査体２４の内部異常を
検査する非破壊検査方法において、磁歪材料を環状に形
成した磁歪リング体４を被検査体２４の表面に接触させ
て配置し、この磁歪リング体４にバイアスコイル１０を
巻回して磁歪リング体４の内部に直流バイアス磁場Ｂ0
を形成し、同時に磁歪リング体４に信号コイル１２を巻
回し、この信号コイル１２による超音波発信感度を前記
直流バイアス磁場Ｂ0により調整し、この信号コイル１
２により磁歪リング体４の内部に超音波領域の変動磁場
ΔＢを生起させ、この変動磁場ΔＢにより磁歪リング体
４の磁歪効果を通して磁歪リング体４を超音波振動さ
せ、この超音波振動により被検査体２４の内部に超音波
を伝播させて被検査体の内部異常を検査することを特徴
とする磁歪超音波素子を用いた非破壊検査方法。7. An ultrasonic wave is made incident on the inside of the object to be inspected 24, and an ultrasonic wave propagating while reflecting the internal structure of the object to be inspected 24 is received on the surface of the object to be inspected and an internal abnormality of the object to be inspected 24 is received. In the non-destructive inspection method for inspecting the magnetostrictive ring, a magnetostrictive ring 4 formed of a magnetostrictive material in an annular shape is placed in contact with the surface of the test object 24, and a bias coil 10 is wound around the magnetostrictive ring 4 to 4, a DC bias magnetic field B 0
At the same time, the signal coil 12 is wound around the magnetostrictive ring body 4, and the ultrasonic wave transmission sensitivity of the signal coil 12 is adjusted by the DC bias magnetic field B 0.
2, a fluctuating magnetic field ΔB in the ultrasonic region is generated inside the magnetostrictive ring 4, and the fluctuating magnetic field ΔB causes the magnetostrictive ring 4 to ultrasonically vibrate through the magnetostrictive effect of the magnetostrictive ring 4. A nondestructive inspection method using a magnetostrictive ultrasonic element, wherein an ultrasonic wave is propagated inside the body 24 to inspect an internal abnormality of the inspection object.
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Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005106812A (en) * | 2003-09-30 | 2005-04-21 | Tokyo Electric Power Co Inc:The | Method of detecting tension wire break in concrete pole |
| JP2008076237A (en) * | 2006-09-21 | 2008-04-03 | Toshiba Corp | Non-destructive inspection device of piping, non-destructive inspection method of piping and power plant |
| KR101015980B1 (en) | 2008-11-28 | 2011-02-23 | 브이제트에이영원주식회사 | Magnetostrictive sensor and Device for detecting welding quality using the same |
| KR101483511B1 (en) | 2008-12-23 | 2015-01-19 | 재단법인 포항산업과학연구원 | Device and method for injection and extraction of ultrasonic using cold spray |
| KR101523347B1 (en) | 2014-07-02 | 2015-08-20 | 서울대학교산학협력단 | Omni-directional shear-horizontal wave electromagnetic acoustic transducer |
| JP2018091685A (en) * | 2016-12-01 | 2018-06-14 | 国立研究開発法人産業技術総合研究所 | Inspection device and inspection method |
| CN114345747A (en) * | 2022-01-10 | 2022-04-15 | 海安县巨力磁材有限责任公司 | Sorting device for judging quality of magnetic ring scars |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5249674U (en) * | 1975-09-18 | 1977-04-08 | ||
| JPH0216900A (en) * | 1988-07-04 | 1990-01-19 | Toyo Commun Equip Co Ltd | Acoustic transducer |
| JPH10253339A (en) * | 1997-03-06 | 1998-09-25 | Mitsubishi Electric Corp | Method and apparatus for measurement by utilizing sound wave |
-
2000
- 2000-09-13 JP JP2000277401A patent/JP4465420B2/en not_active Expired - Fee Related
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5249674U (en) * | 1975-09-18 | 1977-04-08 | ||
| JPH0216900A (en) * | 1988-07-04 | 1990-01-19 | Toyo Commun Equip Co Ltd | Acoustic transducer |
| JPH10253339A (en) * | 1997-03-06 | 1998-09-25 | Mitsubishi Electric Corp | Method and apparatus for measurement by utilizing sound wave |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005106812A (en) * | 2003-09-30 | 2005-04-21 | Tokyo Electric Power Co Inc:The | Method of detecting tension wire break in concrete pole |
| JP4496885B2 (en) * | 2003-09-30 | 2010-07-07 | 東京電力株式会社 | Method for detecting breakage of tension steel wire in concrete column |
| JP2008076237A (en) * | 2006-09-21 | 2008-04-03 | Toshiba Corp | Non-destructive inspection device of piping, non-destructive inspection method of piping and power plant |
| KR101015980B1 (en) | 2008-11-28 | 2011-02-23 | 브이제트에이영원주식회사 | Magnetostrictive sensor and Device for detecting welding quality using the same |
| KR101483511B1 (en) | 2008-12-23 | 2015-01-19 | 재단법인 포항산업과학연구원 | Device and method for injection and extraction of ultrasonic using cold spray |
| KR101523347B1 (en) | 2014-07-02 | 2015-08-20 | 서울대학교산학협력단 | Omni-directional shear-horizontal wave electromagnetic acoustic transducer |
| US9664650B2 (en) | 2014-07-02 | 2017-05-30 | Seoul National University R & Db Foundation | Omni-directional shear-horizontal wave electromagnetic acoustic transducer |
| JP2018091685A (en) * | 2016-12-01 | 2018-06-14 | 国立研究開発法人産業技術総合研究所 | Inspection device and inspection method |
| CN114345747A (en) * | 2022-01-10 | 2022-04-15 | 海安县巨力磁材有限责任公司 | Sorting device for judging quality of magnetic ring scars |
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|---|---|
| JP4465420B2 (en) | 2010-05-19 |
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