JPS61253458A - Ultrasonic flaw detection - Google Patents

Abstract

PURPOSE:To facilitate quantitative judgement on the results of flaw detection with a higher measuring accuracy of in the detection capacity of internal defects of material to be detected, by keeping apparent dimensions of ultrasonic vibrators almost constant as viewed from the material being detected regardless of the angle of refraction of an ultrasonic beam. CONSTITUTION:When emitted with the ultrasonic beam deflection angle theta from ultrasonic vibrators 2l-2m located almost at the center of an array type probe, an ultrasonic beam 3 is refracted on the boundary 8 between a shoe 9 and material 4 to be detected to propagate through the material 4 being detected at the angle theta of refraction. At this point, when the wedge angle of the shoe 9 set at alpha, the angle of incidence of the ultrasonic beam emitted to the shoe 9 at the angle theta of deflection with respect to the boundary plane is given by alpha=phi+gamma. Thus, a signal controller calculates the delay time in the transmission and reception when ultrasonic waves are each transmitted and received by the vibrators 2 at each deflection scan angle of the ultrasonic beam to set transmission and reception delay data to a transmission/reception setter each time the scan angle is altered. Therefore, the transmission and the reception of the ultrasonic beam can be done at a specified angle of refraction, thereby enabling the detection kept of flaws with the beam 3 to the material 4 being detected constant in the thickness.

Description

【発明の詳細な説明】 ［発明の技術分野］ 本発明は電子式セクタ走査型超音波探傷装買を用いて金
属材料や非金属材料等の被検材内部の欠陥を探傷する超
音波探傷方法に関する。[Detailed Description of the Invention] [Technical Field of the Invention] The present invention provides an ultrasonic flaw detection method for detecting defects inside a test material such as a metal material or a non-metal material using an electronic sector scanning type ultrasonic flaw detection device. Regarding.

［発明の技術的背景とその問題点］ 金属材料や非金属材料等の内部を検査する方法としては
従来より超音波探傷方法が用いられている。なかでも、
超音波送受波用の振動子を複数個直線上に配列したアレ
イ型超音波探触子を用い、それぞれの超音波撮動子の超
音波送受信のタイミングを電子的に制御して、超音波の
集束、偏向及び走査を行なう電子走査方式の超音波探傷
法は高速に走査する超音波ビームにより被検材内部を広
範囲に探傷して実時間のＢスコープ表示が得られること
から、高精度探傷への期待が大きい。[Technical background of the invention and its problems] Ultrasonic flaw detection has conventionally been used as a method for inspecting the inside of metallic materials, non-metallic materials, and the like. Among them,
Using an array type ultrasound probe in which multiple transducers for transmitting and receiving ultrasound waves are arranged in a straight line, the timing of transmitting and receiving ultrasound waves from each ultrasound sensor is electronically controlled. The electronic scanning ultrasonic flaw detection method, which uses focusing, deflection, and scanning, can detect a wide range of flaws inside the test material using a high-speed scanning ultrasonic beam and provide real-time B-scope display, making it suitable for high-precision flaw detection. There are high expectations.

この電子走査方式の超音波探傷方法には第３図＜ａ　＞
に示すリニア電子走査法と第３図（ｂ）に示すセクタ電
子走査法とがある。即ち、リニア電子走査法は第３図＜
ａ　＞に示すように、アレイ型超音波探触子１の作動す
る複数の超音波振動子群２を順次切換えながら超音波ビ
ーム３を被検材４の断面方向で直線上に走査し、このリ
ニア走査に２　　対応させて被検材４の断面画像（Ｂス
コープ）をＣＲＴＩの表示器５へ表示する。This electronic scanning ultrasonic flaw detection method is shown in Figure 3<a>.
There are a linear electronic scanning method shown in FIG. 3 and a sector electronic scanning method shown in FIG. 3(b). That is, the linear electronic scanning method is shown in Fig. 3<
a>, the ultrasonic beam 3 is scanned in a straight line in the cross-sectional direction of the specimen 4 while sequentially switching the plurality of operating ultrasonic transducer groups 2 of the array type ultrasonic probe 1. A cross-sectional image (B scope) of the specimen 4 is displayed on the display 5 of the CRTI in correspondence with the linear scan.

セクタ電子走査法は第３図（ｂ　）に示すように、アレ
イ型超音波探触子１の作動する複数個の超音波振動子群
２の超音波受信のタイミングを順次変更しながら超音波
ビーム３を被検材４の断面方向で扇形状に走査し、この
セクター走査に対応させて被検材４の断面画像（Ｂスコ
ープ）をＣＲＴ等の表示器５へ表示する。As shown in FIG. 3(b), the sector electronic scanning method uses ultrasound beams while sequentially changing the timing of ultrasound reception of a plurality of ultrasound transducer groups 2 operated by an array-type ultrasound probe 1. 3 is scanned in a fan shape in the cross-sectional direction of the specimen 4, and a cross-sectional image (B scope) of the specimen 4 is displayed on a display 5 such as a CRT in correspondence with this sector scanning.

いずれの方法においても被検材内部の欠陥６の位置及び
形状に対応した断面画像（Ｂスコープ）として表示し得
るものである。Either method can display a cross-sectional image (B scope) corresponding to the position and shape of the defect 6 inside the specimen.

尚、第３図はアレイ型超音波探触子１を被検材４の表面
上に直接接触させて行なう一般的な探傷法について示し
たが、水浸法あるいはシュー付探傷法などのようにアレ
イ型探触子と被検材との間に超音波伝播媒質を介して行
なう探傷方法にも適用されるが、この場合、第４図に示
すように超音波伝播速度（音速）が異なる媒質■（水）
９および媒質Ｉ　（！１ｌｌ）　４の境界に入射された
超音波ビーム２はスネルの法則により境界８で反射、屈
折、およびモード変換を生じる。Although Fig. 3 shows a general flaw detection method in which the array-type ultrasonic probe 1 is brought into direct contact with the surface of the test material 4, other methods such as the water immersion method or the shoe-equipped flaw detection method can also be used. It is also applied to a flaw detection method in which an ultrasonic propagation medium is used between the array type probe and the test material, but in this case, as shown in Figure 4, the ultrasonic propagation velocity (sound velocity) is ■(Wed)
9 and the medium I (!1ll) 4 The ultrasonic beam 2 incident on the boundary causes reflection, refraction, and mode conversion at the boundary 8 according to Snell's law.

そのため、境界の法線に対する超音波ビーム３の入射角
αと屈折角θとの関係及び超音波ビーム３が境界を通過
するときの能率（往復通過率Ｔ）は、屈折角に対し非線
形的に変化する。Therefore, the relationship between the incident angle α and the refraction angle θ of the ultrasound beam 3 with respect to the normal line of the boundary, and the efficiency when the ultrasound beam 3 passes through the boundary (round-trip passage rate T) are non-linear with respect to the refraction angle. Change.

また、第５図に示すように、超音波振動子２から超音波
伝播媒質９へ放射された超音波ビーム３の幅は超音波振
動子２の寸法（開口＞２Ａとして大差ないが、境界７で
屈折した超音波ビーム３の幅２ＡＭは幾何光学的に考え
ると Ｃｗ：超音波伝播媒質の音速 ＣＭ：被検材の音速 とすることができ、一般に超音波伝播媒質９の音速Ｃｗ
は被検材４の音速ＣＭより小さいため屈折した超音波の
ビーム幅は細くなる。この事は、被検材中から見た超音
波撮動子の寸法が小さくなることを意味している。Furthermore, as shown in FIG. 5, the width of the ultrasonic beam 3 emitted from the ultrasonic transducer 2 to the ultrasonic propagation medium 9 is not much different as the dimensions of the ultrasonic transducer 2 (aperture > 2A), Considering the width 2AM of the ultrasound beam 3 refracted at
Since the sound velocity CM is smaller than the sound velocity CM of the test material 4, the beam width of the refracted ultrasonic wave becomes narrow. This means that the dimensions of the ultrasonic sensor seen from inside the material to be inspected become smaller.

すなわち、屈折角が大きい程超音波振動子の見かけの寸
法は小さくなり、従って超音波ビームの指向性が悪くな
ると共に遠方における欠陥の検出感度が低くなるという
第２の問題が生じる。That is, the larger the refraction angle, the smaller the apparent dimensions of the ultrasonic transducer, which causes the second problem of worsening the directivity of the ultrasonic beam and lowering the sensitivity for detecting defects at a distance.

以上のことから、電子走査方式の水浸法あるいは、シュ
ー付探傷法において桿比較的、上記問題点の影響が少な
いリニア電子走査方式が実用に供されるがセクタ電子走
査の場合超音波ビーム偏向走査角度毎に超音波ビーム特
性が変化するために欠陥の位置によってその検出感度及
び位置、寸法測定精度が異なり、十分な探傷精度を得ら
れていないのが現状である。Based on the above, the electronic scanning water immersion method or the linear electronic scanning method, which is less affected by the above problems compared to the shoe flaw detection method, is put into practical use, but in the case of sector electronic scanning, the ultrasonic beam deflection Since the ultrasonic beam characteristics change depending on the scanning angle, the detection sensitivity, position, and dimension measurement accuracy vary depending on the location of the defect, and the current situation is that sufficient flaw detection accuracy cannot be obtained.

［発明の目的］ 本発明は上記事情にもとづいてなされたものであり、ア
レイ型超音波探触子と被検材との間に超音波伝播媒質を
介してセクタ電子走査方式の超音波探傷を行なう場合に
おいても被検材内部欠陥の検出能及び欠陥寸法、位置測
定精度が向上し、探傷結果の定量的な判断が容易な超音
波探傷方法を提供することを目的とする。[Object of the Invention] The present invention has been made based on the above circumstances, and it provides ultrasonic flaw detection using a sector electronic scanning method via an ultrasonic propagation medium between an array type ultrasonic probe and a test material. It is an object of the present invention to provide an ultrasonic flaw detection method that improves the ability to detect internal defects in a material to be inspected and the accuracy of defect size and position measurement, and facilitates quantitative judgment of flaw detection results.

［発明の概要］ 上記目的を達成するため本発明による超音波探傷方法で
は、アレイ型超音波探触子と被検材との間に超音波伝播
媒質を介してセクタ電子走査を行なう場合において、超
音波伝播媒質内の超音波伝播速度と被検材内での屈折超
音波の伝播速度と超音波ビーム偏向による境界面への入
射角とから、被検材より見た超音波振動子の見かけの寸
法（開口）が超音波ビーム偏向角度にかかわらず略一定
となるような超音波振動子の実寸法（開口）をあらかじ
め算出しておき、これにもとづいてアレイ型探触子の作
動する超音波振動子数の選定を超音波ビーム偏向角度毎
に行ない、超音波ビーム偏向による境界面での屈折に伴
なう超音波ビームの往復通過率の変化を補正する往復通
過率補正データと、超音波ビームの伝播距離による減衰
を補正する距離振幅補正データをあらかじめ作成し、こ
の往復通過率補正データと距離振幅補正データにもとづ
き、超音波ビーム偏向角度毎の超音波ビーム伝播距離に
応じてアレイ型超音波探触子で受波された超音波受信号
の振幅を補正し、これを表示器への画像信号とすること
により、超音波ビーム１向角度にかかわらず、一様な超
音波ビーム特性により被検材内部をセクタ電子走査する
ことが可能であり、かつ被検材内部の欠陥位置にかかわ
らず一様な探傷感度が得られ、欠陥の検出能及び欠陥位
置、寸法精度を高めることを可能とする。[Summary of the Invention] In order to achieve the above object, in the ultrasonic flaw detection method according to the present invention, when performing sector electronic scanning via an ultrasonic propagation medium between an array type ultrasonic probe and a test material, The appearance of the ultrasonic transducer as seen from the specimen material is determined from the ultrasound propagation velocity in the ultrasound propagation medium, the propagation velocity of the refracted ultrasound in the specimen material, and the angle of incidence on the boundary surface due to ultrasound beam deflection. The actual size (aperture) of the ultrasonic transducer is calculated in advance so that the size (aperture) of the ultrasonic transducer is approximately constant regardless of the ultrasonic beam deflection angle, and based on this, the The number of sonic transducers is selected for each ultrasound beam deflection angle, and the round-trip passage rate correction data corrects the change in the round-trip passage rate of the ultrasound beam due to refraction at the boundary surface due to ultrasound beam deflection. Distance amplitude correction data is created in advance to correct the attenuation due to the propagation distance of the acoustic beam, and based on this round trip passage rate correction data and distance amplitude correction data, the array type is By correcting the amplitude of the ultrasound signal received by the ultrasound probe and using this as an image signal to the display, uniform ultrasound beam characteristics can be achieved regardless of the direction angle of the ultrasound beam. This makes it possible to perform sector electronic scanning of the inside of the material to be inspected, and to obtain uniform flaw detection sensitivity regardless of the defect location inside the material to be inspected, improving defect detection ability, defect location, and dimensional accuracy. possible.

［発明の実論例１ 以下本発明の・一実施例を図面にもとづいて詳細に説明
する。[Practical Example 1 of the Invention An embodiment of the present invention will be described in detail below based on the drawings.

第１図は本発明の一実施例を示す構成図である。FIG. 1 is a block diagram showing an embodiment of the present invention.

アレイ型超音波探触子１はｎ個の超音波振動子９からな
る。これらの超音波振動子９はそれぞれ送信パルスを発
生するｎ個の超音波送信器１０と結合されており、この
超音波送信器１０は送信遅延時間設定器１１からの送信
パルス発生用トリガ信号によってｎ個全部あるいは一部
の送信器が選定されてそれぞれの対応する超音波振動子
９へ送信パルスを送り、これに応答して超音波振動子９
が超音波を送波づ”るように構成されている。−５超音
波振動子９は可逆性を有しており、超音波の音圧変化に
応じた電気信号を発生することｂ′できる。The array type ultrasonic probe 1 consists of n ultrasonic transducers 9. These ultrasonic transducers 9 are each coupled with n ultrasonic transmitters 10 that generate transmission pulses, and these ultrasonic transmitters 10 are activated by a transmission pulse generation trigger signal from a transmission delay time setting device 11. All or some of the n transmitters are selected and send transmission pulses to their corresponding ultrasonic transducers 9, and in response, the ultrasonic transducers 9
The ultrasonic transducer 9 is configured to transmit ultrasonic waves.-5 The ultrasonic transducer 9 has reversibility and can generate electrical signals in response to changes in the sound pressure of the ultrasonic waves. .

このように超音波振動子９は受信機能をも有しているの
で、それぞれの超音波撮動子９で検出した受信信号はそ
れぞれ対応する超音波受信器１２によって増幅された後
、対応する、ｎ個のＡ／Ｄ変換器１３へ入力される。In this way, since the ultrasound transducers 9 also have a receiving function, the reception signals detected by each ultrasound sensor 9 are amplified by the corresponding ultrasound receivers 12, and then the corresponding The signal is input to n A/D converters 13.

このＡ／Ｄ変換器１３は超音波受信号を高速でディジタ
ル信号に変換するものであり、超音波受信波形を忠実に
ディジタル量に変換することができる。またＡ／Ｄ変換
器１３には超音波受信信号のデジタル変換開始用トリガ
信号が受信遅延時間設定器１４からそれぞれ供給されて
いる。このトリガ信号を受（プたｎ個全部あるいは一部
のＡ／Ｄ変換器１３はトリガ信号の入力時点に同期して
超音波受信波形がディジタル化される。This A/D converter 13 converts the ultrasonic reception signal into a digital signal at high speed, and can faithfully convert the ultrasonic reception waveform into a digital quantity. Further, a trigger signal for starting digital conversion of the ultrasonic reception signal is supplied to the A/D converter 13 from a reception delay time setting device 14, respectively. Upon receiving this trigger signal, all or some of the A/D converters 13 digitize the ultrasonic reception waveform in synchronization with the input time of the trigger signal.

信号処理器１５は受信遅延時間設定器１４、送信遅延時
間設定器１１に対して超音波送・受信にかかわる超音波
振動子群２に対応する送信発生１〜リガ信号およびＡ／
Ｄ変換開始用トリガ信号の０Ｎ−ＯＦＦの設定を行なう
と共に、超音波ビームの送波および受波の方向、ざらに
集束点距離に応じたトリガ出力のタイミングの設定を行
なう。The signal processor 15 sends signals to the reception delay time setter 14 and the transmission delay time setter 11 from transmission generation 1 to trigger signals and A/
The ON-OFF setting of the trigger signal for starting D conversion is performed, and the timing of the trigger output is also set in accordance with the directions of transmitting and receiving the ultrasonic beam, and roughly the focal point distance.

また、各Ａ／Ｄ変換器１３の出力は加算メモリ１６に波
形加算して記憶される。すなわちＡ１０変換器１３にい
ったん保持された超音波振動子９による受信信号のディ
ジタル波形はそれぞれのディジタル化された時点をそろ
えディジタル加算されて加算メモリ１６に記憶される。Further, the outputs of each A/D converter 13 are waveform-added and stored in an addition memory 16. That is, the digital waveforms of the signals received by the ultrasonic transducer 9, which are once held in the A10 converter 13, are digitally added by aligning their digitized time points and stored in the addition memory 16.

加算メモリ１６の加算された超音波受信号ディジタル波
形は信号処理器１７へ入力され、所定の信号処理により
画像信号として表示器１８へ出力される。The ultrasonic reception signal digital waveform added in the addition memory 16 is input to a signal processor 17, and is outputted to a display 18 as an image signal through predetermined signal processing.

ここで、信号処理器１７は、信号制御器１５によってあ
らかじめ設定された超音波の送波および受波時の超音波
ビームの偏向角度により、Ｂスコープ表示の画像掃引の
開始点及び方向を定め、Ｂスコープ表示のための画＠掃
引信号を表示器１８へ出力すると共に、前記加算メモリ
１６からのディジタル加算された超音波受信号をＤ　、
／　Ａ変換した後検波し画像輝度信号として前述の画＠
掃引信号と共に表示器１８へ出力している。さらに信号
処理器１７は、加算された超音波受信号をＤ／Ａ変換し
た時点において信号制御器１５によりあらかじめ設定さ
れた振幅補正データにもとづき超音波受信号の振幅補正
を行なうよう構成されている。Here, the signal processor 17 determines the starting point and direction of the image sweep on the B scope display based on the deflection angle of the ultrasound beam during ultrasound transmission and reception, which is set in advance by the signal controller 15. While outputting the image@sweep signal for B scope display to the display 18, the digitally added ultrasonic reception signal from the addition memory 16 is output to D,
/ The above-mentioned image @ is detected as an image luminance signal after A conversion.
It is output to the display 18 together with the sweep signal. Further, the signal processor 17 is configured to perform amplitude correction of the ultrasonic reception signal based on amplitude correction data set in advance by the signal controller 15 at the time when the added ultrasonic reception signal is D/A converted. .

このようにして第１図に示した超音波探傷装置は送信お
よび受信にかかわる超音波振動子の選定と送受信遅延時
間の設定及び受信信号の振幅補正を、超音波ビーム偏向
角度毎にくりかえし行なう。In this manner, the ultrasonic flaw detection apparatus shown in FIG. 1 repeatedly selects ultrasonic transducers involved in transmission and reception, sets transmission and reception delay times, and corrects the amplitude of the received signal for each ultrasonic beam deflection angle.

次に第２図を参照し本実施例にかかわる超音波探傷方法
について説明する。Next, referring to FIG. 2, the ultrasonic flaw detection method according to this embodiment will be explained.

第２図では超音波伝播媒質としてアクリル樹脂製のシュ
ー８を付加したアレイ型探触子１を用いて被検材４をセ
クター探傷する場合について説明する。即ち、アレイ型
超音波探触子１内の略中央に位置する超音波振動子群＜
２Ｊｌ）〜２　（ｎ＋　）が超音波ビーム偏向角くシュ
ー９内で）φで超音波を放射すると、その超音波ビーム
３はシュー９と被検材４との境界８で屈折し、屈折角θ
で被検材４内を伝播する。この時、シュー９のくさび角
度をαとした場合、偏向角φでシュー９に放射された超
音波ビームの境界面に対する入射角はα−φ＋γとなり
、被検材４への屈折角θとの関係はシュー９、および被
検材４の音速をそれぞれσＷ。In FIG. 2, a case will be explained in which a sector flaw detection is performed on a test material 4 using an array type probe 1 to which a shoe 8 made of acrylic resin is added as an ultrasonic wave propagation medium. That is, the ultrasonic transducer group located approximately at the center of the array type ultrasonic probe 1<
2Jl) ~ 2 (n+) emits an ultrasonic wave with an ultrasonic beam deflection angle )φ inside the shoe 9, the ultrasonic beam 3 is refracted at the boundary 8 between the shoe 9 and the test material 4, and the refraction angle θ
and propagates within the test material 4. At this time, if the wedge angle of the shoe 9 is α, the incident angle of the ultrasonic beam radiated to the shoe 9 at the deflection angle φ to the boundary surface is α − φ + γ, which is the same as the refraction angle θ to the test material 4. The relationship is σW for the sound speed of shoe 9 and test material 4, respectively.

σ□とするとスネルの法則により、下記式（２であられ
すことができる。If σ□, then according to Snell's law, it can be expressed by the following formula (2).

よって各超音波振動子２にかかわる超音波送受信のタイ
ミングを次式（３）で与えることで所定屈折角度での超
音波ビームの偏向走査を制御できる。Therefore, by giving the timing of ultrasonic transmission and reception regarding each ultrasonic transducer 2 using the following equation (3), it is possible to control the deflection and scanning of the ultrasonic beam at a predetermined refraction angle.

但し［］　ｍａｘは超音波振動子ＮＱ　（１）〜（ｎ）
の最大値をとることの意味、αは振動子間隔 従って信号制御器１５は、超音波振動子群２のそれぞれ
が超音波を送受信する時の送受信遅延鍔間を超音波ビー
ム偏向走査角度（この場合屈折角）毎にあらかじめ（３
）式により算出しておき、超音波ビーム偏向走査角度の
変更毎に、送信遅延設定器１１及び受信遅延設定器１４
へその送受信遅延データを設定する。それ故所定屈折角
での超音波ビームの送受信を行なう事ができる。However, [ ] max is the ultrasonic transducer NQ (1) to (n)
α is the transducer spacing. Therefore, the signal controller 15 determines the ultrasonic beam deflection scanning angle (this (3) in advance for each refraction angle)
), and each time the ultrasonic beam deflection scanning angle is changed, the transmission delay setter 11 and the reception delay setter 14 are
Set the navel transmission/reception delay data. Therefore, the ultrasonic beam can be transmitted and received at a predetermined refraction angle.

この時、超音波伝播媒質であるシュー９の超音波の音速
は被検材４の屈折超音波の音速よりも遅いため、屈折に
よる、被検材４から見た見かけの振動子寸法２ＡＭはシ
ュー９内での超音波ビーム偏向方向から見た見かけの振
動子寸法２Ａｗが下記式（４）となるため、 ２Ａｗ＝２Ａｃｏｓφ　　　　　　　　・（４）（１）
式で示した寸法と異なり、次（５）式で示す見かけの振
動子寸法となる。At this time, since the sound speed of the ultrasonic wave in the shoe 9, which is the ultrasonic propagation medium, is slower than the sound speed of the refracted ultrasonic wave in the test material 4, the apparent transducer dimension 2AM as seen from the test material 4 due to refraction is The apparent transducer dimension 2Aw as seen from the ultrasonic beam deflection direction within 9 is the following formula (4), so 2Aw=2Acosφ ・(4)(1)
Unlike the dimensions shown in the equation, the apparent vibrator dimensions are shown in the following equation (5).

従って、被検材４より見た見かけの振動子寸法２Ａｗが
超音波ビーム偏向走査角度（ここでは屈折角度）にかか
わらず一定とするためには、実際の振動子寸法２Ａを下
記（６）式とすればよく、アレイ型探触子１の作動する
振動子群２を下記式（７）として選定する。Therefore, in order to keep the apparent transducer dimension 2Aw as seen from the specimen 4 constant regardless of the ultrasonic beam deflection and scanning angle (here, the refraction angle), the actual transducer dimension 2A can be calculated using the following formula (6). The transducer group 2 that operates in the array type probe 1 is selected as shown in the following formula (7).

２Ａ−ｉ−Ｎ−ｄ　　　　　　　　　　　　　・・・（
７）但し、Ｎは作動する振動子数 これより、信号処理器１５は、超音波ビーム偏向走査角
度毎のアレイ型探触子の作動する振動子数を上記式（６
）１７）によりあらかじめ算出しておき、超音波ビーム
の偏向走査角度９変更毎に、送信遅延設定器１１及び受
信遅延設定器１４へ超音波振動子群選択データの設定を
行なう。それ故超音波ビーム偏向走査角度にかかわらず
、被検材４への超音波ビーム３を一定の太さとして探傷
が行なえる。2A-i-N-d...(
7) However, N is the number of actuated transducers. From this, the signal processor 15 calculates the number of actuated transducers of the array type probe for each ultrasonic beam deflection scanning angle using the above formula (6).
) 17), and the ultrasonic transducer group selection data is set in the transmission delay setter 11 and the reception delay setter 14 every time the deflection and scanning angle of the ultrasound beam is changed by nine. Therefore, regardless of the ultrasonic beam deflection scanning angle, flaw detection can be performed with the ultrasonic beam 3 directed onto the specimen 4 having a constant thickness.

一方、超音波伝播質（水）９と被検材（ｒｔＩ）４との
境界を通過する時の屈折角度に対する往復通過率の例を
第４図に示したように屈折角度θによって大きく変化す
ることから、超音波ビーム偏向角度によって欠陥検出感
度が異なってしまう。また、超音波が伝播することによ
る減衰を生じるため超音波伝播距離方向の欠陥検出感度
も異なる。On the other hand, as shown in Fig. 4, an example of the round-trip passage rate with respect to the refraction angle when passing through the boundary between the ultrasonic propagation medium (water) 9 and the test material (rtI) 4 changes greatly depending on the refraction angle θ. Therefore, defect detection sensitivity differs depending on the ultrasonic beam deflection angle. Furthermore, since attenuation occurs due to the propagation of ultrasonic waves, the defect detection sensitivity in the direction of the ultrasonic propagation distance also differs.

そのためあらかじめ測定して得られた、超音波ビーム偏
向角度毎の距離振幅特性データにもとづき、信号処理器
１５は、超音波ビーム偏向走査角度毎に、一定の欠陥検
出感度となるよな距離振幅補正データを演算して信号処
理器１７に設定し、信号処理器１７はその距離振幅補正
データを受け、超音波振動子群それぞれで受波された後
超音波受信号の位相加算された単一の受信号波形の振幅
補正を行ない、超音波ビーム偏向角度毎及び超音波ビー
ム伝播距離にかかわらず一定の欠陥検出感度となるよう
動作すると共に、受信号波形の検波を行ない、表示器１
８への画像信号を、画像掃引信号と共に出力する。これ
により表示器１８は、超音波ビームの伝播径路に対応し
た画ｍ掃引を行なうと共に、超音波受信号の振幅に応じ
て輝度変調されるため、被検材４の超音波ビーム偏向走
査断面方向の欠陥位置、寸法、分布を精度よくＢスコー
プ表示し得るものである。Therefore, based on the distance amplitude characteristic data for each ultrasonic beam deflection angle obtained by measurement in advance, the signal processor 15 performs distance amplitude correction such that a constant defect detection sensitivity is achieved for each ultrasonic beam deflection scanning angle. The data is calculated and set in the signal processor 17, and the signal processor 17 receives the distance and amplitude correction data, and after being received by each ultrasonic transducer group, a single signal is obtained by adding the phases of the ultrasonic received signals. The amplitude of the received signal waveform is corrected and the defect detection sensitivity is constant regardless of the ultrasonic beam deflection angle and the ultrasonic beam propagation distance.
The image signal to 8 is output together with the image sweep signal. As a result, the display 18 performs an image sweep corresponding to the propagation path of the ultrasonic beam, and the brightness is modulated according to the amplitude of the ultrasonic reception signal, so that the display 18 can be moved in the ultrasonic beam deflection scanning cross-sectional direction of the specimen 4. B-scope can display the defect position, size, and distribution with high accuracy.

以上説明した実施例では、アレイ型探触子１と被検材４
との間にアクリル樹脂製のシューを超音波伝播媒質９と
して用いているが本発明では超音波媒質の材質の制限は
受けないので超音波伝播媒質を変えた場合についても適
用されるものである。In the embodiment described above, the array type probe 1 and the test material 4
A shoe made of acrylic resin is used as the ultrasonic propagation medium 9 between the ultrasonic propagation medium 9 and the ultrasonic propagation medium 9. However, the present invention is not subject to any limitations on the material of the ultrasonic medium, and is therefore applicable even when the ultrasonic propagation medium is changed. .

また、被検材４の探傷面が曲率を有する場合においても
シューの形状をその曲率に合せたり、超音波伝播媒質９
を液体とすることで対応でき、超音波伝播媒質内での超
音波ビーム偏向角度と被検材への屈折角度との関係式を
若干変更するだけで対応できることから本発明の範囲に
含まれるものである。In addition, even if the testing surface of the test material 4 has a curvature, the shape of the shoe may be adjusted to match the curvature, or the ultrasonic propagation medium 9 may be
This can be handled by making it a liquid, and it can be handled by simply changing the relational expression between the ultrasonic beam deflection angle in the ultrasound propagation medium and the refraction angle to the specimen material, so it is included in the scope of the present invention. It is.

さらに、本発明の主旨を逸脱しない範囲で本実施例の構
成を変えることは、本発明の効果と何らかわらないので
本発明に含まれるものである。Further, changes in the structure of this embodiment without departing from the spirit of the present invention do not change the effects of the present invention in any way and are therefore included in the present invention.

［発明の効果］ 以上実施例にもとづいて説明したように本発明によれば
、アレイ型探触子と被検材表面との間に超音波伝播媒質
を介してセクタ電子走査を行なった場合においても、超
音波ビームがその境界で屈折することによる見かけの超
音波振動子寸法の縮小の補正を超音波ビーム偏向走査角
度毎に作動する超音波撮動子群の振動子数を制御し、さ
らに超音波ビームの屈折による境界での超音波往復通過
率の変化及び、距離振幅特性の補正を超音波ビーム偏向
走査角度毎に超音波受波信号波形の振幅を制御して被検
材内部に対応するＢスコープを表示するようにしたので
、超音波ビーム偏向走査角度にかかわりなく一様な特性
の超音波ビームで被検材内部を走査することが可能であ
り、欠陥位置にかかわりなく一定の欠陥検出感度で探傷
し得、被検材内部の欠陥検出能が向上すると共に、欠陥
の位置、寸法、分布を正確に検出できる超音波探傷方法
が提供できるものである。[Effects of the Invention] As described above based on the embodiments, according to the present invention, when sector electronic scanning is performed via an ultrasonic propagation medium between an array type probe and the surface of a test material, In addition, the number of transducers in the ultrasonic imager group operated at each ultrasonic beam deflection scanning angle is controlled to compensate for the reduction in the apparent size of the ultrasonic transducer due to refraction of the ultrasonic beam at the boundary. Changes in the ultrasonic round-trip passage rate at the boundary due to refraction of the ultrasonic beam and correction of distance amplitude characteristics can be handled inside the specimen by controlling the amplitude of the ultrasonic received signal waveform for each ultrasonic beam deflection and scanning angle. Since the B scope is displayed, it is possible to scan the inside of the specimen with an ultrasonic beam with uniform characteristics regardless of the ultrasonic beam deflection scanning angle, and it is possible to detect certain defects regardless of the defect location. It is possible to provide an ultrasonic flaw detection method that can perform flaw detection with high detection sensitivity, improve the ability to detect defects inside a test material, and accurately detect the position, size, and distribution of defects.

【図面の簡単な説明】[Brief explanation of the drawing]

第１図は本発明の一実施例にかかわる超音波探傷＠ｉ置
の構成図、第２図は本発明による信号制御器の作用を説
明するための図、第３図乃至第５図は夫々従来の技術を
説明するための図である。 １・・・アレイ型探触子、３・・・超音波ビーム、４・
・・被検材、９・・・超音波伝播媒質、１１・・・信号
制御器、１７・・・信号処理器、２Ａ・・・超音波振動
子実寸法、２Ａ、・・・見かけの超音波振動子寸法、α
・・・入射角、θ・・・屈折角、φ・・・超音波伝播媒
質内ビーム偏向角、γ・・・くさび角度。 出願人代理人　弁理士　鈴江武彦 第３図FIG. 1 is a block diagram of an ultrasonic flaw detection @i location according to an embodiment of the present invention, FIG. 2 is a diagram for explaining the operation of a signal controller according to the present invention, and FIGS. 3 to 5 are respectively FIG. 2 is a diagram for explaining a conventional technique. 1...Array type probe, 3...Ultrasonic beam, 4...
... Test material, 9... Ultrasonic propagation medium, 11... Signal controller, 17... Signal processor, 2A... Actual dimensions of ultrasonic transducer, 2A,... Apparent ultrasonic Sound wave transducer dimensions, α
...Incidence angle, θ...Refraction angle, φ...Beam deflection angle in the ultrasound propagation medium, γ...Wedge angle. Applicant's agent Patent attorney Takehiko Suzue Figure 3

Claims (1)

【特許請求の範囲】[Claims] 被検材表面に超音波媒質を介して配置されたアレイ型探
触子の各振動子による超音波の送波および受波のタイミ
ングを電子制御し、被検材内部を扇形走査してＢスコー
プ表示像を実時間で得る超音波探傷方法において、超音
波ビームの屈折角にかかわりなく被検材から見たみかけ
の超音波振動子群の寸法が略一定となるように、上記ア
レイ型超音波探触子の作動する超音波振動子群の振動子
数を超音波ビーム偏向走査角度毎に選定し、屈折角によ
って変化する境界面での往復通過率特性と距離振幅特性
とにもとづく振幅補正データにより超音波ビーム偏向走
査角度毎に超音波受波信号の振幅を補正することを特徴
とする超音波探傷方法。The timing of transmitting and receiving ultrasonic waves by each transducer of an array type probe placed on the surface of the specimen through an ultrasonic medium is electronically controlled, and the interior of the specimen is scanned in a fan-shaped manner. In the ultrasonic flaw detection method that obtains a display image in real time, the array type ultrasonic wave is The number of transducers in the ultrasonic transducer group operated by the probe is selected for each ultrasonic beam deflection scanning angle, and amplitude correction data is generated based on the round-trip passage rate characteristics and distance amplitude characteristics at the interface that change depending on the refraction angle. An ultrasonic flaw detection method characterized by correcting the amplitude of an ultrasonic received signal for each ultrasonic beam deflection scanning angle.