JP4731358B2 - Ultrasonic spot weld evaluation method and apparatus - Google Patents

Ultrasonic spot weld evaluation method and apparatus Download PDF

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JP4731358B2
JP4731358B2 JP2006053559A JP2006053559A JP4731358B2 JP 4731358 B2 JP4731358 B2 JP 4731358B2 JP 2006053559 A JP2006053559 A JP 2006053559A JP 2006053559 A JP2006053559 A JP 2006053559A JP 4731358 B2 JP4731358 B2 JP 4731358B2
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ultrasonic
propagation path
nugget
spot
transmission time
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JP2007232526A (en
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一 高田
裕 足立
一浩 野間
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JFE Steel Corp
Toyota Auto Body Co Ltd
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Description

本発明は、スポット溶接によって形成される溶融部(ナゲット)の直径を、超音波を利用した非破壊手段にて検査する方法及び装置に関する。   The present invention relates to a method and an apparatus for inspecting the diameter of a melted portion (nugget) formed by spot welding with nondestructive means using ultrasonic waves.

近年、例えば自動車ボディの製造工場などにおいては、スポット溶接部の検査を現場で高能率に行えるようにするため、簡便に実施可能なスポット溶接検査方法が待望されている。   2. Description of the Related Art In recent years, for example, in an automobile body manufacturing factory, a spot welding inspection method that can be easily implemented is desired in order to perform inspection of a spot welded portion with high efficiency on site.

自動車のボディは、数千点にも及ぶスポット溶接によって組立てられており、スポット溶接の良否が車体の強度や耐久性に直接影響を及ぼすため、スポット溶接が適切に行われているか否かを検査することは極めて重要である。従来、このようなスポット溶接部の検査方法として、スポット溶接された金属板の間へタガネを差込み、スポット溶接部が剥離するか否かを確認することにより良否を判定するタガネ検査が行われている。しかし、タガネ検査を行うとスポット溶接部が割れる場合があるので、タガネ検査によってはスポット溶接の良否を正確に判定することが困難である。また、タガネ検査によって破壊されたスポット溶接部を製品へ利用することは不可能であるため、コストが高くつく問題がある。   The body of an automobile is assembled by thousands of spot welds, and the quality of spot welds directly affects the strength and durability of the car body. It is extremely important to do. Conventionally, as a method for inspecting such spot welds, a ladle inspection for determining pass / fail is performed by inserting a chisel between spot-welded metal plates and confirming whether or not the spot weld is peeled off. However, since spot welding may break when performing a chisel inspection, it is difficult to accurately determine whether or not spot welding is good depending on the chisel inspection. Further, since it is impossible to use the spot welded portion destroyed by the chisel inspection for the product, there is a problem that the cost is high.

そこで、近年、超音波を用いてスポット溶接部の良否を非破壊で検査する装置及び方法が種々提案されている。   In recent years, various apparatuses and methods for inspecting the quality of spot welds using ultrasonic waves in a nondestructive manner have been proposed.

例えば特許文献1〜4には、2枚の板を重ねて溶接され製作されるスポット溶接部の良否評価のために、板面に垂直に超音波を入射させて反射波を検出する方法や装置が開示されている。又、特許文献5には、被検体を介してその上下に1組の局部水浸探触子を対向に配置して被検体を水平方向に移動させることにより、送信側局部水浸探触子から送信される超音波ビームにより被検体のスポット溶接部を走査し、受信側局部水浸探触子により受信された信号からスポット溶接部中の傷の有無を判定する超音波探傷装置が開示されている。   For example, Patent Documents 1 to 4 disclose a method and an apparatus for detecting reflected waves by allowing ultrasonic waves to be incident perpendicularly to a plate surface in order to evaluate the quality of a spot welded portion that is manufactured by overlapping two plates. Is disclosed. Further, in Patent Document 5, a pair of local water immersion probes are arranged on the upper and lower sides of a subject so as to face each other and the subject is moved in the horizontal direction, whereby a transmission-side local water immersion probe is obtained. An ultrasonic flaw detector is disclosed that scans a spot welded portion of an object with an ultrasonic beam transmitted from the receiver and determines the presence or absence of a flaw in the spot welded portion from a signal received by a receiving-side local water immersion probe. ing.

特開2000−146928号公報JP 2000-146828 A 特開2002−131297号公報JP 2002-131297 A 特開平11−2627号公報Japanese Patent Laid-Open No. 11-2627 特開平6−265529号公報JP-A-6-265529 特開昭62−52456号公報JP-A-62-52456 特開2004−163210号公報JP 2004-163210 A

しかし、これらの先行技術では、平板状の被検体に対して垂直方向に超音波を送受信する。よって、図22に例示する被検体のスポット溶接部102に形成されるくぼみ102bの周囲に形成される傾斜面102cにおいて、超音波ビームを効率よく被検体内に入射させることができないため、スポット溶接部102に形成されるナゲット102aの大きさを高精度に検出することが難しいという問題がある。   However, in these prior arts, ultrasonic waves are transmitted and received in a vertical direction with respect to a flat subject. Therefore, since the ultrasonic beam cannot efficiently enter the subject on the inclined surface 102c formed around the recess 102b formed in the spot welded portion 102 of the subject illustrated in FIG. 22, spot welding is performed. There is a problem that it is difficult to detect the size of the nugget 102a formed in the portion 102 with high accuracy.

即ち、図22に示すように、上板101aと下板101bを重ねてスポット溶接すると、スポット溶接部102には、上板101aと下板101bの接合部に「ナゲット」と呼ばれる溶融凝固組織102aが形成される。又、スポット溶接では、図示しない電極チップによって上板101a及び下板101bが強圧されるので、上板101a及び下板101bの表面には、電極チップの先端部の形状に相当するくぼみ102bが形成される。更に、当該くぼみ102bの底面と上板101a及び下板101bの表面との間には、円錐状の傾斜面102cが形成される。溶接が正常に行われた場合、前記ナゲット102aの直径は、溶接に使用される電極チップの直径よりもやや大きいか同等程度になり、くぼみ102bの内径は、電極チップの先端部の形状が面取りを有する円柱形に形成されていることから、電極チップの円柱部の直径よりもやや小さくなる。従って、くぼみ102bの内径は、ナゲット102aの径よりもやや小さくなるのが通常である。溶接が正常に行われなかった場合には、ナゲット径が正常に溶接が行われた場合に比べて小さくなり、強度不足等の異常が発生する。なお、図中の符号Sは、ナゲット102aの止端を示している。   That is, as shown in FIG. 22, when the upper plate 101a and the lower plate 101b are overlapped and spot welded, the spot welded portion 102 has a melt-solidified structure 102a called “nugget” at the joint between the upper plate 101a and the lower plate 101b. Is formed. In spot welding, since the upper plate 101a and the lower plate 101b are strongly pressed by electrode tips (not shown), a recess 102b corresponding to the shape of the tip of the electrode tip is formed on the surfaces of the upper plate 101a and the lower plate 101b. Is done. Further, a conical inclined surface 102c is formed between the bottom surface of the recess 102b and the surfaces of the upper plate 101a and the lower plate 101b. When welding is performed normally, the diameter of the nugget 102a is slightly larger than or equal to the diameter of the electrode tip used for welding, and the inner diameter of the recess 102b is chamfered because the shape of the tip of the electrode tip is chamfered. Since it is formed in the column shape which has, it becomes a little smaller than the diameter of the column part of an electrode tip. Therefore, the inner diameter of the recess 102b is usually slightly smaller than the diameter of the nugget 102a. When welding is not performed normally, the nugget diameter is smaller than when welding is performed normally, and abnormalities such as insufficient strength occur. In addition, the code | symbol S in a figure has shown the toe of the nugget 102a.

このように、スポット溶接部102には、くぼみ102bの底面と上板101a及び下板101bの表面との間に円錐状の傾斜面102cが形成されるので、前記先行技術に係る超音波検査装置のように、超音波ビームを被検体である上板101a及び下板101bの表面に対して垂直方向に送受信して検査すると、超音波が傾斜面102cにおいて反射され、被検体の内部に殆ど伝搬しないため、検査部位からの信号が殆ど得られない。前述のように、ナゲット102aの大きさは、電極チップの直径よりもやや大きいか同等程度の直径になるので、ナゲット102aの止端Sと被検体に形成される傾斜面102cとは殆ど重なりあっている。従って、超音波が傾斜面102cにおいて反射されると、ナゲット止端Sの近辺からの正確な信号が得られにくくなり、正確なナゲット直径の判定及び欠陥の有無の判定をすることが困難になる。   Thus, since the conical inclined surface 102c is formed between the bottom surface of the recess 102b and the surfaces of the upper plate 101a and the lower plate 101b in the spot welded portion 102, the ultrasonic inspection apparatus according to the prior art described above. When the ultrasonic beam is transmitted / received in the direction perpendicular to the surfaces of the upper plate 101a and the lower plate 101b, which are subjects, as described above, the ultrasonic wave is reflected on the inclined surface 102c and almost propagates inside the subject. Therefore, almost no signal is obtained from the examination site. As described above, since the size of the nugget 102a is slightly larger than or equal to the diameter of the electrode tip, the toe S of the nugget 102a and the inclined surface 102c formed on the subject almost overlap each other. ing. Therefore, when the ultrasonic wave is reflected on the inclined surface 102c, it is difficult to obtain an accurate signal from the vicinity of the nugget toe S, and it is difficult to accurately determine the nugget diameter and the presence / absence of a defect. .

本願発明者の一部は既に特許文献6において、複数の金属板を重ね合わせて溶接してなるスポット溶接部の超音波による評価方法において、スポット溶接部の外側の金属板にスポット溶接部の溶接金属に向けてLamb波を励起し、Lamb波を溶接金属に透過させ、透過後Lamb波を受信することにより、スポット溶接部の健全性を評価することを特徴とする超音波によるスポット溶接部の評価方法を提案した。この技術によって、スポット溶接部に生成されるくぼみの周囲に形成される傾斜面の影響を受けずにスポット溶接部の評価を行なうことに成功した。しかし、特許文献6では、2つのLamb波探触子をスポット溶接部を挟んで向かい合わせて配置するに際し、2つのLamb波探触子とスポット溶接部との位置関係が所定の位置関係からずれると、Lamb波の伝搬経路がスポット溶接部の中心からずれるため、正しくスポット溶接部の健全性を評価できないことがあると判明した。上記問題は、2つのLamb波探触子とスポット溶接部との位置関係は目視により確認するしか手段がないことに起因している。   Part of the inventors of the present application already disclosed in Patent Document 6 an ultrasonic evaluation method of a spot welded portion formed by superposing and welding a plurality of metal plates, and welding the spot welded portion to a metal plate outside the spot welded portion Exciting Lamb waves toward the metal, transmitting the Lamb waves to the weld metal, and receiving the Lamb waves after transmission, the soundness of the spot welds is evaluated. An evaluation method was proposed. By this technique, the spot welded portion was successfully evaluated without being affected by the inclined surface formed around the recess generated in the spot welded portion. However, in Patent Document 6, when two Lamb wave probes are arranged facing each other across the spot welded portion, the positional relationship between the two Lamb wave probes and the spot welded portion deviates from a predetermined positional relationship. The Lamb wave propagation path deviates from the center of the spot weld, and it has been found that the soundness of the spot weld cannot be evaluated correctly. The above problem is due to the fact that the positional relationship between the two Lamb wave probes and the spot welded part can only be confirmed visually.

ここにいうLamb波(Lamb wave)とは、板波(plate wave)とも称され、薄板(金属板、非金属板のいずれでもよい)へ超音波を特定の入射角で斜めに入射させた場合に発生する。入射波の屈折によって薄板中に生成された斜め進行する縦波や横波が薄板の表面および裏面においてモード変換を伴う反射を繰り返しながら伝搬して干渉する結果、薄板が板厚中心に関して対称、あるいは非対称に変位する進行波が生成される。この進行波がLamb波である(Joseph L. Rose、 Ultrasonic waves in solid media、 pp.101-126、 Cambridge Univ Press、 Cambridge、 1999を参照)。なお、Lamb波探触子とは、薄板へLamb波を励起するために、特定の入射角で超音波を薄板へ入射させることができる超音波探触子である。また、この探触子をLamb波の受波に用いることが可能である。   The Lamb wave here is also called a plate wave, and an ultrasonic wave is incident obliquely on a thin plate (either a metal plate or a non-metal plate) at a specific incident angle. Occurs. Obliquely traveling longitudinal and transverse waves generated in the thin plate by refraction of the incident wave propagate and interfere with repeated reflection with mode conversion on the front and back surfaces of the thin plate. As a result, the thin plate is symmetric or asymmetric with respect to the thickness center. A traveling wave is generated that displaces to. This traveling wave is a Lamb wave (see Joseph L. Rose, Ultrasonic waves in solid media, pp. 101-126, Cambridge Univ Press, Cambridge, 1999). The Lamb wave probe is an ultrasonic probe that can cause an ultrasonic wave to be incident on a thin plate at a specific incident angle in order to excite a Lamb wave on the thin plate. Further, this probe can be used for receiving a Lamb wave.

本発明は、かかる従来技術の不備を解決するためになされたものであって、その課題とするところは、短時間(例えば、1点当たり5秒以内)に限られる測定であっても、超音波探触子の位置とスポット溶接部の位置とのずれに影響されずに、信頼性高くスポット溶接部の健全性(ナゲットの有無、ナゲット径、溶接割れ)を評価することにある。また、スポット溶接部のナゲットの大きさを視覚的にとらえやすい表示を行うことにより、ナゲットの大きさの判別を行いやすいようにすることにある。   The present invention has been made to solve such deficiencies of the prior art, and the problem is that even if measurement is limited to a short time (for example, within 5 seconds per point), It is to evaluate the soundness (presence / absence of nugget, nugget diameter, weld crack) of the spot welded portion with high reliability without being influenced by the deviation between the position of the acoustic probe and the position of the spot welded portion. Another object of the present invention is to make it easy to determine the size of the nugget by displaying the size of the nugget of the spot welded portion so that it can be easily grasped visually.

本発明は、複数の金属板を重ね合わせて溶接してなるスポット溶接部の超音波による評価方法において、金属板またはスポット溶接部の表面沿いの方向と厚さ方向とによって形成される断面内を伝搬する超音波を被検体の表面沿いに伝搬する超音波と称することとしたとき、スポット溶接部の外側の金属板の複数の送波位置から複数方向へ向けて、被検体の表面沿いに伝搬する超音波を、振動子アレイを備えた超音波探触子により送波し、スポット溶接部の外側の金属板の複数の受波位置において、伝搬経路にスポット溶接部を含まない被検体の表面沿いに伝搬してきた超音波、及び伝搬経路にスポット溶接部を含む被検体の表面沿いに伝搬してきた超音波を、振動子アレイを備えた超音波探触子により受波し、前記複数の送波位置と前記複数の受波位置とを結ぶ伝搬経路の各々において、受波された受波超音波の伝達時間を基準伝達時間と比較し、(|受波超音波の伝達時間−基準伝達時間|/基準伝達時間)がしきい値以下である場合には、受波超音波がその伝搬経路にナゲットを含まないと判定し、前記伝搬経路の中からナゲットが存在しない伝搬経路を抽出し、該抽出されたナゲットが存在しない伝搬経路によって囲まれる領域に基づいてナゲット径を算出するようにして、前記課題を解決したものである。 The present invention relates to an ultrasonic evaluation method for a spot welded portion formed by superposing and welding a plurality of metal plates, and a cross section formed by a direction along the surface of the metal plate or spot welded portion and a thickness direction. When the propagating ultrasonic waves are referred to as ultrasonic waves propagating along the surface of the subject, they propagate along the surface of the subject from a plurality of transmission positions on the metal plate outside the spot welded portion in a plurality of directions. the ultrasound, and transmitting the ultrasonic probe having a transducer array, a plurality of wave receiving positions outside the metal plate of the spot welds, the surface of the subject to the propagation path does not include a spot weld The ultrasonic wave propagating along the surface and the ultrasonic wave propagating along the surface of the subject including the spot weld in the propagation path are received by the ultrasonic probe including the transducer array, and the plurality of transmissions are received. Wave position and the above In each of the propagation path connecting the reception position, compared to a reference transmission time transmission time of reception it has been received wave ultrasound, (| reception ultrasonic propagation time - reference transmission time | / reference transmission time ) Is equal to or less than the threshold value, it is determined that the received ultrasonic wave does not include a nugget in the propagation path, a propagation path in which no nugget exists is extracted from the propagation path, and the extracted nugget is extracted. and calculate the nugget diameter on the basis of a region surrounded by the propagation path but does not exist, is obtained by solving the above problems.

本発明は、又、複数の金属板を重ね合わせて溶接してなるスポット溶接部の超音波による評価方法において、金属板またはスポット溶接部の表面沿いの方向と厚さ方向とによって形成される断面内を伝搬する超音波を被検体の表面沿いに伝搬する超音波と称することとしたとき、スポット溶接部の外側の金属板の複数の送波位置から複数方向へ向けて、被検体の表面沿いに伝搬する超音波を、振動子アレイを備えた超音波探触子により送波し、スポット溶接部の外側の金属板の複数の受波位置において、伝搬経路にスポット溶接部を含まない被検体の表面沿いに伝搬してきた超音波、及び伝搬経路にスポット溶接部を含む被検体の表面沿いに伝搬してきた超音波を、振動子アレイを備えた超音波探触子により受波し、前記複数の送波位置と前記複数の受波位置とを結ぶ伝搬経路の各々において受波された受波超音波の伝達時間を基準伝達時間と比較し、(|受波超音波の伝達時間−基準伝達時間|/基準伝達時間)がしきい値以上である場合には、受波超音波がその伝搬経路にナゲットを含むと判定し、前記伝搬経路の中からナゲットが存在する伝搬経路を抽出し、該抽出されたナゲットが存在する伝搬経路の存在範囲に基づいてナゲット径を算出するようにして、前記課題を解決したものである。 The present invention also provides an ultrasonic evaluation method of a spot welded portion formed by superposing and welding a plurality of metal plates, and a cross section formed by a direction along the surface of the metal plate or spot welded portion and a thickness direction. When the ultrasonic wave propagating in the interior is referred to as the ultrasonic wave propagating along the surface of the subject, it is directed along the surface of the subject from a plurality of transmission positions of the metal plate on the outer side of the spot welded portion toward a plurality of directions. subject propagating ultrasonic waves, and transmit the ultrasonic probe having a transducer array, which does not include the plurality of wave reception position of the outer metal plate of the spot weld, spot weld the propagation path The ultrasonic wave propagating along the surface of the object and the ultrasonic wave propagating along the surface of the subject including the spot weld in the propagation path are received by an ultrasonic probe having a transducer array, Wave transmission position and front In each of the propagation path connecting the plurality of reception locations, and compared with a reference transmission time transmission time of reception has been received wave ultrasound, (| reception ultrasonic propagation time - reference transmission time | / reference transmitted Time) is equal to or greater than the threshold value, it is determined that the received ultrasonic wave includes a nugget in the propagation path, a propagation path in which the nugget exists is extracted from the propagation path, and the extracted nugget is extracted. The above problem is solved by calculating the nugget diameter based on the existence range of the propagation path in which there is.

本発明は、又、複数の金属板を重ね合わせて溶接してなるスポット溶接部の超音波による評価装置において、金属板またはスポット溶接部の表面沿いの方向と厚さ方向とによって形成される断面内を伝搬する超音波を被検体の表面沿いに伝搬する超音波と称することとしたとき、スポット溶接部の外側の金属板の複数の送波位置から複数方向へ向けて、被検体の表面沿いに伝搬する超音波を送波する、振動子アレイを備えた超音波探触子と、スポット溶接部の外側の金属板の複数の受波位置において、伝搬経路にスポット溶接部を含まない被検体の表面沿いに伝搬してきた超音波、及び伝搬経路にスポット溶接部を含む被検体の表面沿いに伝搬してきた超音波を受波する、振動子アレイを備えた超音波探触子と、前記複数の送波位置と前記複数の受波位置とを結ぶ伝搬経路の各々において、受波された受波超音波の伝達時間を基準伝達時間と比較し、(|受波超音波の伝達時間−基準伝達時間|/基準伝達時間)がしきい値以下である場合には、受波超音波がその伝搬経路にナゲットを含まないと判定し、前記伝搬経路の中からナゲットが存在しない伝搬経路を抽出し、該抽出されたナゲットが存在しない伝搬経路に囲まれる領域に基づいてナゲット径を算出する手段と、を備えることにより、同じく前記課題を解決したものである。 The present invention also provides an ultrasonic evaluation apparatus for a spot welded portion formed by superposing and welding a plurality of metal plates, and a cross section formed by the direction along the surface of the metal plate or spot welded portion and the thickness direction. When the ultrasonic wave propagating in the interior is referred to as the ultrasonic wave propagating along the surface of the subject, it is directed along the surface of the subject from a plurality of transmission positions of the metal plate on the outer side of the spot welded portion toward a plurality of directions. An object that does not include a spot weld in the propagation path at an ultrasonic probe having an transducer array that transmits an ultrasonic wave propagating to the surface and a plurality of receiving positions of a metal plate outside the spot weld An ultrasonic probe having a transducer array for receiving ultrasonic waves propagating along the surface of the object and ultrasonic waves propagating along the surface of the subject including a spot weld in the propagation path; The transmission position of the In each of the propagation path connecting the reception position, and the comparison reference transmission time transmission time of reception it has been received wave ultrasound, (| reception ultrasonic propagation time - reference transmission time | / reference transmitted If (time) is less than or equal to a threshold value, it is determined that the received ultrasonic wave does not include a nugget in the propagation path, and a propagation path in which no nugget exists is extracted from the propagation path. means for calculating a nugget diameter on the basis of a region surrounded by the propagation path nugget is not present, by providing, at same that solves the above problems.

本発明は、又、複数の金属板を重ね合わせて溶接してなるスポット溶接部の超音波による評価装置において、金属板またはスポット溶接部の表面沿いの方向と厚さ方向とによって形成される断面内を伝搬する超音波を被検体の表面沿いに伝搬する超音波と称することとしたとき、スポット溶接部の外側の金属板の複数の送波位置から複数方向へ向けて、被検体の表面沿いに伝搬する超音波を送波する、振動子アレイを備えた超音波探触子と、スポット溶接部の外側の金属板の複数の受波位置において、伝搬経路にスポット溶接部を含まない被検体の表面沿いに伝搬してきた超音波、及び伝搬経路にスポット溶接部を含む被検体の表面沿いに伝搬してきた超音波を受波する、振動子アレイを備えた超音波探触子と、前記複数の送波位置と前記複数の受波位置とを結ぶ伝搬経路の各々において、受波された受波超音波の伝達時間を基準伝達時間と比較し、(|受波超音波の伝達時間−基準伝達時間|/基準伝達時間)がしきい値以上である場合には、受波超音波がその伝搬経路にナゲットを含むと判定し、前記伝搬経路の中からナゲットが存在する伝搬経路を抽出し、該抽出されたナゲットが存在する伝搬経路の存在範囲に基づいてナゲット径を算出する手段と、を備えることにより、前記課題を解決したものである。 The present invention also provides an ultrasonic evaluation apparatus for a spot welded portion formed by superposing and welding a plurality of metal plates, and a cross section formed by the direction along the surface of the metal plate or spot welded portion and the thickness direction. When the ultrasonic wave propagating in the interior is referred to as the ultrasonic wave propagating along the surface of the subject, it is directed along the surface of the subject from a plurality of transmission positions of the metal plate on the outer side of the spot welded portion toward a plurality of directions. An object that does not include a spot weld in the propagation path at an ultrasonic probe having an transducer array that transmits an ultrasonic wave propagating to the surface and a plurality of receiving positions of a metal plate outside the spot weld An ultrasonic probe having a transducer array for receiving ultrasonic waves propagating along the surface of the object and ultrasonic waves propagating along the surface of the subject including a spot weld in the propagation path; The transmission position of the In each of the propagation path connecting the reception position, compared to a reference transmission time transmission time of reception it has been received wave ultrasound, (| reception ultrasonic propagation time - reference transmission time | / reference transmission time ) Is equal to or greater than the threshold value, it is determined that the received ultrasonic wave includes a nugget in the propagation path, a propagation path in which the nugget exists is extracted from the propagation path, and the extracted nugget is Means for calculating the nugget diameter based on the existence range of the existing propagation paths, thereby solving the above-mentioned problem.

本発明によれば、スポット溶接部に形成されるくぼみの周囲に形成される傾斜面の影響を受けずに、正確に非破壊でスポット溶接部の評価を行なうことが可能になると共に、測定時間が、短時間に限られる測定であっても、超音波探触子の位置とスポット溶接部の位置のずれに影響されずに、信頼性高くスポット溶接部の健全性を評価することが可能になる。また、スポット溶接部のナゲットの大きさを視覚的にとらえやすいので、ナゲットの大きさの判別を行いやすい。   According to the present invention, the spot welded portion can be accurately evaluated in a nondestructive manner without being affected by the inclined surface formed around the recess formed in the spot welded portion, and the measurement time However, even if the measurement is limited to a short time, it is possible to evaluate the soundness of the spot weld with high reliability without being affected by the displacement of the position of the ultrasonic probe and the position of the spot weld. Become. Further, since the size of the nugget at the spot welded portion is easily grasped visually, it is easy to determine the size of the nugget.

以下、図面を参照して、本発明の実施形態を詳細に説明する。   Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

以下、2枚の金属板が接合されてなるスポット溶接部の評価を例にとり説明する。2枚の金属板の上側の板を上板、下側の板を下板と称する。本発明では、図1に示すとおり、振動子アレイ11を備えた超音波探触子10と振動子アレイ21を備えた超音波探触子20とを、上板1a上のスポット溶接部2を挟んだ位置に向かい合わせて当接させる。超音波探触子10及び超音波探触子20と上板1aとの間には適当な接触媒質を介在させる。   Hereinafter, the evaluation of a spot welded portion formed by joining two metal plates will be described as an example. The upper plate of the two metal plates is called the upper plate, and the lower plate is called the lower plate. In the present invention, as shown in FIG. 1, the ultrasonic probe 10 having the transducer array 11 and the ultrasonic probe 20 having the transducer array 21 are connected to the spot welded portion 2 on the upper plate 1a. Abut against the pinched position. An appropriate contact medium is interposed between the ultrasonic probe 10 and the ultrasonic probe 20 and the upper plate 1a.

振動子アレイ11を備えた超音波探触子10を用いて、複数の位置から上板1aに超音波を送波する。超音波探触子10は、樹脂くさび12に振動子アレイ11が貼り付けられた構造を有しており、振動子アレイ11から送波された超音波が斜めに上板1aへ入射する。前記斜めに入射した超音波によって、図2に示す如く、上板1aの中に上板1a表面に対して斜めに進行する超音波が送波される。該斜め進行する超音波は、縦波および横波を含み、上板1aの底面及び表面において反射やモード変換を繰り返しながら、上板1a中を伝搬する。図2において実線は横波であり、破線は縦波である。超音波の上板1aへの入射角が適当な値の場合には、上記反射を繰り返して伝搬する超音波は、Lamb波と呼ばれる波動になる。伝搬してきた超音波は、振動子アレイ21を備えた超音波探触子20によって受波される。超音波探触子20は、樹脂くさび22に振動子アレイ21が貼り付けられた構造を有している。   Using the ultrasonic probe 10 having the transducer array 11, ultrasonic waves are transmitted from a plurality of positions to the upper plate 1a. The ultrasonic probe 10 has a structure in which a transducer array 11 is attached to a resin wedge 12, and ultrasonic waves transmitted from the transducer array 11 are obliquely incident on the upper plate 1a. As shown in FIG. 2, the ultrasonic waves traveling obliquely with respect to the surface of the upper plate 1a are transmitted into the upper plate 1a by the obliquely incident ultrasonic waves. The obliquely traveling ultrasonic waves include longitudinal waves and transverse waves, and propagate through the upper plate 1a while repeating reflection and mode conversion on the bottom surface and surface of the upper plate 1a. In FIG. 2, a solid line is a transverse wave, and a broken line is a longitudinal wave. When the incident angle of the ultrasonic wave on the upper plate 1a is an appropriate value, the ultrasonic wave that propagates by repeating the reflection becomes a wave called a Lamb wave. The propagating ultrasonic wave is received by the ultrasonic probe 20 including the transducer array 21. The ultrasonic probe 20 has a structure in which a transducer array 21 is attached to a resin wedge 22.

振動子アレイ11を備えた超音波探触子10と振動子アレイ21を備えた超音波探触子20とによって、図3に示す平面経路(金属板の上面からみた経路)を伝搬した超音波を受信することができる。超音波探触子10の振動子アレイ11の個々の振動子を11〜11と表し、超音波探触子20の振動子アレイ21の個々の振動子を21〜21と表すことにする。Nとしては例えば4、8、16、32などの個数を用いる。図3はNが16の場合である。振動子アレイの振動子11〜11から送波される超音波には空間的に広がりがあるので、振動子11〜11から図3に示した平面経路をとる超音波を送波することができる。 The ultrasonic wave propagating along the plane path (path seen from the upper surface of the metal plate) shown in FIG. 3 by the ultrasonic probe 10 including the transducer array 11 and the ultrasonic probe 20 including the transducer array 21. Can be received. The individual transducers of the transducer array 11 of the ultrasonic probe 10 are represented as 11 1 to 11 N, and the individual transducers of the transducer array 21 of the ultrasonic probe 20 are represented as 21 1 to 21 N. To. As N, for example, the number of 4, 8, 16, 32 or the like is used. FIG. 3 shows a case where N is 16. Since the ultrasonic waves transmitted from the transducers 11 1 to 11 N of the transducer array have a spatial spread, the ultrasonic waves taking the planar path shown in FIG. 3 are transmitted from the transducers 11 1 to 11 N. can do.

超音波探触子10の振動子11から送波された超音波を、超音波探触子20の振動子21〜21によって受波する。次に、超音波探触子10の振動子11から送波された超音波を、超音波探触子20の振動子21〜21によって受波する。この過程を、超音波探触子10の振動子11から送波された超音波を、超音波探触子20の振動子21〜21によって受波するまで、送波を行う振動子11(n=1、2、‥、N)を順次変更して行う。この結果、複数位置から送波され複数の方向へ伝搬する超音波を、超音波探触子20の振動子21〜21によって受波することができる。 The ultrasonic wave transmitted from the transducer 11 1 of the ultrasonic probe 10 and reception by the ultrasound probe 20 of the vibrator 21 1 through 21 N. Then, the ultrasonic wave transmitted from the transducer 11 and second ultrasonic probe 10, for reception by the ultrasound probe 20 of the vibrator 21 1 through 21 N. This process, the ultrasonic wave transmitted from the transducer 11 N of the ultrasonic probe 10, until the reception by the ultrasound probe 20 of the vibrator 21 1 through 21 N, oscillator performs transmitting 11 n (n = 1, 2,..., N) are sequentially changed. As a result, ultrasonic waves transmitted from a plurality of positions and propagating in a plurality of directions can be received by the transducers 21 1 to 21 N of the ultrasonic probe 20.

スポット溶接部2に生成されるナゲット2aは、図4に示すとおり、ほぼ板厚方向に平行な方向性を有する溶融凝固組織2bとなっている。この溶融凝固組織2bはデンドライト組織とも呼ばれ、一方向へ延びた粗い結晶の集まりであるため、金属板の金属組織に比べ、超音波の伝達が悪い(減衰が大きい)性質を持っている。よって、図3に示した経路を伝搬する超音波は、その経路に溶融凝固組織2bが含まれる場合、伝搬経路に存在する溶融凝固組織2bの長さに応じた減衰を受ける結果、その振幅が低下して超音波探触子20に受波される。   As shown in FIG. 4, the nugget 2a generated in the spot welded portion 2 is a molten and solidified structure 2b having a directionality substantially parallel to the plate thickness direction. The melt-solidified structure 2b is also called a dendrite structure, and is a collection of coarse crystals extending in one direction, and therefore has a property that ultrasonic transmission is poor (attenuation is large) compared to the metal structure of a metal plate. Therefore, when the ultrasonic wave propagating in the path shown in FIG. 3 includes the molten solidified structure 2b in the path, the ultrasonic wave is attenuated according to the length of the molten solidified structure 2b existing in the propagation path. It is lowered and received by the ultrasonic probe 20.

また、溶融凝固組織2bは、この中を超音波が伝搬する速度が金属板の金属組織とは若干異なる性質を持っている。溶融凝固組織2bでは、図4に示すミクロ金属組織の模式図のように金属結晶の特定の方位(図4に破線の矢印を用いて示す)が板厚(z)方向にほぼ揃っているため、該組織は弾性的な異方性を持っている。従って、超音波は、その伝搬する方向に依存して伝搬速度が変化する。これに対して、金属板の金属組織では金属結晶がランダムな方向に向いているため、超音波の伝搬速度はその伝搬方向に依存せず、一定の値となる。以上、説明したことによって、被検体の表面沿いに伝搬する超音波の伝搬速度は、伝搬経路に溶融凝固組織2bを含む場合と伝搬経路に溶融凝固組織2bを含まない場合(金属板の金属組織のみを伝搬)との間で異なるのが一般的である。従って、被検体の表面沿いに伝搬する超音波の伝搬経路に溶融凝固組織2bがあった場合には、溶融凝固組織2bの板表面に平行な長さに応じて伝達に要する時間が変化する。よって、図3に示した経路を伝搬する超音波は、その経路に溶融凝固組織2bが含まれる場合、伝搬経路に存在する溶融凝固組織2bの長さに応じて伝達に要する時間(以下、伝達時間)が変化した後、超音波探触子20に受波される。なお、伝達時間は透過時間とも呼ばれる。   Further, the melt-solidified structure 2b has a property that the speed of propagation of ultrasonic waves therein is slightly different from that of the metal structure of the metal plate. In the melt-solidified structure 2b, as shown in the schematic diagram of the micro metal structure shown in FIG. 4, the specific orientation of the metal crystal (shown using a broken arrow in FIG. 4) is almost aligned in the plate thickness (z) direction. The tissue has elastic anisotropy. Therefore, the propagation speed of the ultrasonic wave changes depending on the propagation direction. On the other hand, since the metal crystal is oriented in a random direction in the metal structure of the metal plate, the propagation speed of the ultrasonic wave does not depend on the propagation direction and becomes a constant value. As described above, the propagation speed of the ultrasonic wave propagating along the surface of the subject is determined when the propagation path includes the molten solidified structure 2b and when the propagation path does not include the molten solidified structure 2b (the metal structure of the metal plate). Is generally different). Therefore, when the molten solidified tissue 2b is present in the propagation path of the ultrasonic wave propagating along the surface of the subject, the time required for transmission varies depending on the length parallel to the plate surface of the molten solidified tissue 2b. Therefore, when the ultrasonic wave propagating through the path shown in FIG. 3 includes the molten and solidified tissue 2b, the time required for transmission according to the length of the molten and solidified tissue 2b existing in the propagation path (hereinafter referred to as transmission). Is received by the ultrasonic probe 20. The transmission time is also called transmission time.

以下、まず第1参考例を説明する。 Hereinafter, first, a description will be given of a first reference example.

図5は、板厚2.6mmの2枚の鋼板を重ねてスポット溶接を行ったサンプルに、前記したように超音波探触子10及び超音波探触子20をスポット溶接部2を挟んで向かい合わせて当接させ、超音波探触子10の振動子11〜11から送波された超音波を、超音波探触子20の振動子21〜21によって受波した後、受波超音波の形態を基準と比較し、前記受波超音波の形態が基準と異ならない受波超音波の伝搬経路を実線を用いて示した結果である。ここで、Nは16とし、受波超音波の形態としてはその振幅を用いた。また、スポット溶接部がない板厚2.6mmの平坦な鋼板へ超音波探触子10及び超音波探触子20を向かい合わせて当接させ、超音波探触子10の振動子11〜11から送波された超音波を、超音波探触子20の振動子21〜21によって受波した場合の受波超音波の振幅を基準として用いた。図5に示されている実線は溶融凝固組織2bを含まない超音波の伝搬経路であるから、交錯した実線に囲まれた内側の領域に溶融凝固組織2bが存在する。また、交錯した実線に囲まれた内側の領域のアレイ配列方向での長さが板表面に垂直な方向から見たときの溶融凝固組織2bの大きさ、即ち、ナゲット径に比例する。 FIG. 5 shows a sample in which two steel plates having a thickness of 2.6 mm are overlapped and spot-welded, and the ultrasonic probe 10 and the ultrasonic probe 20 are sandwiched between the spot welds 2 as described above. After receiving the ultrasonic waves transmitted from the transducers 11 1 to 11 N of the ultrasonic probe 10 by the transducers 21 1 to 21 N of the ultrasonic probe 20, It is the result which showed the propagation path of the received ultrasonic wave by which the form of a received ultrasonic wave is compared with a reference | standard, and the said received ultrasonic wave form is not different from a reference | standard using the continuous line. Here, N is 16 and the amplitude is used as the form of the received ultrasonic wave. In addition, the ultrasonic probe 10 and the ultrasonic probe 20 are brought into contact with each other on a flat steel plate having a thickness of 2.6 mm that does not have a spot weld, and the transducers 11 1 to 11 of the ultrasonic probe 10 are brought into contact with each other. The amplitude of the received ultrasonic waves when the ultrasonic waves transmitted from 11 N were received by the transducers 21 1 to 21 N of the ultrasonic probe 20 was used as a reference. Since the solid line shown in FIG. 5 is an ultrasonic wave propagation path that does not include the melted and solidified structure 2b, the melted and solidified structure 2b exists in the inner region surrounded by the intersecting solid lines. Further, the length in the array arrangement direction of the inner region surrounded by the intersecting solid lines is proportional to the size of the melt-solidified structure 2b when viewed from the direction perpendicular to the plate surface, that is, the nugget diameter.

次に、本発明の第実施形態を説明する。 Next, a first embodiment of the present invention will be described.

図6は板厚2.6mmの2枚の鋼板を重ねてスポット溶接を行ったサンプルに、前記したように超音波探触子10及び超音波探触子20をスポット溶接部2を挟んで向かい合わせて当接させ、超音波探触子10の振動子11〜11から送波された超音波を、超音波探触子20の振動子21〜21によって受波した後、受波超音波の形態を基準と比較し、前記受波超音波の形態が基準と異ならない受波超音波の伝搬経路を実線を用いて示した結果である。ここで、Nは16とし、受波超音波の形態としてはその伝達時間を用いた。また、スポット溶接部がない板厚2.6mmの平坦な鋼板へ超音波探触子10及び超音波探触子20を向かい合わせて当接させ、超音波探触子10の振動子11〜11から送波された超音波を、超音波探触子20の振動子21〜21によって受波した場合の受波超音波の伝達時間を基準として用いた。図6に示されている実線は溶融凝固組織2bを含まない超音波の伝搬経路であるから、交錯した実線に囲まれた内側の領域に溶融凝固組織2bが存在する。また、交錯した実線に囲まれた内側の領域のアレイ配列方向での長さが板表面に垂直な方向から見たときの溶融凝固組織2bの大きさ、即ち、ナゲット径に比例する。 FIG. 6 shows a sample in which two steel plates having a thickness of 2.6 mm are overlapped and spot-welded, and the ultrasonic probe 10 and the ultrasonic probe 20 face each other with the spot welded portion 2 interposed therebetween as described above. The ultrasonic waves transmitted from the transducers 11 1 to 11 N of the ultrasonic probe 10 are received by the transducers 21 1 to 21 N of the ultrasonic probe 20 and then received. It is the result which showed the propagation path of the received ultrasonic wave in which the form of the wave ultrasonic wave was compared with the reference | standard, and the form of the said received ultrasonic wave was not different from a reference | standard using the continuous line. Here, N is 16, and the transmission time is used as the form of received ultrasonic waves. In addition, the ultrasonic probe 10 and the ultrasonic probe 20 are brought into contact with each other on a flat steel plate having a thickness of 2.6 mm that does not have a spot weld, and the transducers 11 1 to 11 of the ultrasonic probe 10 are brought into contact with each other. The transmission time of the received ultrasonic waves when the ultrasonic waves transmitted from 11 N were received by the transducers 21 1 to 21 N of the ultrasonic probe 20 was used as a reference. Since the solid line shown in FIG. 6 is an ultrasonic wave propagation path that does not include the melted and solidified structure 2b, the melted and solidified structure 2b exists in the inner region surrounded by the intersecting solid lines. Further, the length in the array arrangement direction of the inner region surrounded by the intersecting solid lines is proportional to the size of the melt-solidified structure 2b when viewed from the direction perpendicular to the plate surface, that is, the nugget diameter.

図7は第実施形態を実施するための装置の一例を示している。この装置は、超音波の送波に用いられる振動子アレイ11〜1116を備えた超音波探触子10及び超音波の受波に用いられる振動子アレイ21〜2116を備えた超音波探触子20、前記振動子アレイ11〜1116の振動子から超音波を送波するのに用いられる電気パルスを供給し、又、前記振動子アレイ21〜2116が受波した超音波の信号を増幅する超音波送受信器30、該超音波送受信器30と振動子アレイ11〜1116との間に介在して、振動子アレイ11〜1116の各振動子と超音波送受信器30との接続を切り替えるスイッチ回路25、前記超音波送受信器30と振動子アレイ21〜2116との間に介在して、振動子アレイ21〜2116の各振動子と超音波送受信器30との接続を切り替えるスイッチ回路26、前記超音波送受信器30によって増幅された信号のうち被検体の表面沿いに伝搬する超音波による信号を取り出すゲート手段31、該ゲート手段31によって取り出された受波超音波の信号から超音波の伝達時間を検出する時間計測手段32によって構成されている。なお、超音波送受信器30によって増幅された信号をA/D変換し、ソフトウェアによって、ディジタル化された信号から被検体の表面沿いに伝搬する超音波の伝達時間を検出するようにゲート手段31および時間計測手段32を構成することもできる。 FIG. 7 shows an example of an apparatus for carrying out the first embodiment. This apparatus includes an ultrasonic probe 10 including transducer arrays 11 1 to 11 16 used for transmitting ultrasonic waves and an ultrasonic device including transducer arrays 21 1 to 21 16 used for receiving ultrasonic waves. An electric pulse used to transmit ultrasonic waves from the transducer 20 and the transducers of the transducer arrays 11 1 to 11 16 is supplied, and the transducer arrays 21 1 to 21 16 receive the waves. An ultrasonic transmitter / receiver 30 for amplifying an ultrasonic signal, and interposed between the ultrasonic transmitter / receiver 30 and the transducer arrays 11 1 to 11 16 , the transducers of the transducer arrays 11 1 to 11 16 The switch circuit 25 for switching the connection with the acoustic wave transmitter / receiver 30 is interposed between the ultrasonic wave transmitter / receiver 30 and the transducer arrays 21 1 to 21 16, and the transducers of the transducer arrays 21 1 to 21 16 Connection with sound wave transmitter / receiver 30 Switch circuit 26 for switching, a gate means 31 for extracting a signal by an ultrasonic wave propagating along the surface of the subject among signals amplified by the ultrasonic transmitter / receiver 30, and a received ultrasonic wave extracted by the gate means 31 It is comprised by the time measurement means 32 which detects the transmission time of an ultrasonic wave from a signal. It should be noted that the signal amplified by the ultrasonic transmitter / receiver 30 is A / D converted, and the gate means 31 and the software are used to detect the transmission time of the ultrasonic wave propagating along the surface of the subject from the digitized signal. The time measuring means 32 can also be configured.

図7に示した第実施形態の装置において、超音波探触子10及び20のクサビ材12、22をポリスチロールとし、振動子アレイ11〜1116及び21〜2116のアレイ配列方向における振動子の幅を0.8mm、超音波の上板表面への入射角が34.7°となるようにしてスポット溶接部2の測定を実施した。測定の対象として板厚2.6mmの2枚の鋼板を重ねてスポット溶接して作製された30個のサンプルを用いた。また、スポット溶接部がない板厚2.6mmの平坦な鋼板へ超音波探触子10及び超音波探触子20を向かい合わせて当接させ、超音波探触子10の振動子アレイ11〜1116から送波された超音波を、超音波探触子20の振動子アレイ21〜2116によって受波した場合の受波超音波の伝達時間を基準(基準伝達時間)として用いた。受波超音波の伝達時間と基準伝達時間とを比較し、(|受波超音波の伝達時間−基準伝達時間|/基準伝達時間)がしきい値(本例では0.5%)以下である場合には、受波超音波がその伝搬経路に溶融凝固組織2bを含まないと判定するようにした。ナゲット径の測定では、図5と同様に、振動子アレイ11〜1116と振動子アレイ21〜2116との超音波伝搬経路のうち、溶融凝固組織2bを含まない超音波の伝搬経路を求め、交錯した実線に囲まれた内側の領域のアレイ配列方向での長さを求めた。一例を図8に示す。また、溶融凝固組織2bの存在をわかりやすく表示するため、図9に示す2次元表示を行った。図9では、超音波探触子10と超音波探触子20との間の2次元領域を所定の微小要素(図9では0.2mm×0.2mmの大きさ)に分割し、溶融凝固組織2bを含まないと判定された経路上の要素を白色で表示するようにした。図9は図8に示した例の2次元表示である。 In the apparatus according to the first embodiment shown in FIG. 7, the wedge members 12 and 22 of the ultrasonic probes 10 and 20 are made of polystyrene, and the array directions of the transducer arrays 11 1 to 11 16 and 21 1 to 21 16 are arranged. The spot welded portion 2 was measured so that the width of the vibrator was 0.8 mm and the incident angle of the ultrasonic wave on the upper plate surface was 34.7 °. Thirty samples prepared by stacking two steel plates having a thickness of 2.6 mm and spot welding were used as measurement targets. Further, the ultrasonic probe 10 and the ultrasonic probe 20 are brought into contact with each other on a flat steel plate having a thickness of 2.6 mm without a spot welded portion, and the transducer array 11 1 of the ultrasonic probe 10 is contacted. the ultrasonic wave transmitted from to 11 16, with transmission time of the reception ultrasonic wave in the case of reception by the transducer array 21 1 to 21 16 of the ultrasonic probe 20 as a reference (reference transmission time) . Compare the transmission time of the received ultrasonic wave with the reference transmission time, and (| received ultrasonic wave transmission time-reference transmission time | / reference transmission time) is less than the threshold value (0.5% in this example) In some cases, it is determined that the received ultrasonic wave does not include the molten and solidified structure 2b in its propagation path. In the measurement of the nugget diameter, in the same way as in FIG. 5, among the ultrasonic propagation paths of the transducer arrays 11 1 to 11 16 and the transducer arrays 21 1 to 21 16 , the propagation path of the ultrasonic waves that do not include the molten solidified tissue 2 b. And the length in the array arrangement direction of the inner region surrounded by the intersecting solid lines was obtained. An example is shown in FIG. Further, in order to display the presence of the melt-solidified structure 2b in an easy-to-understand manner, the two-dimensional display shown in FIG. 9 was performed. In FIG. 9, the two-dimensional region between the ultrasonic probe 10 and the ultrasonic probe 20 is divided into predetermined microelements (size of 0.2 mm × 0.2 mm in FIG. 9) and melted and solidified. The elements on the path determined not to include the tissue 2b are displayed in white. FIG. 9 is a two-dimensional display of the example shown in FIG.

図7に示した第実施形態の装置による(本発明による)測定結果を図10に示す。図10では、横軸に切断試験の結果求められたナゲット径をとり、縦軸に本発明の方法により求められたナゲット径をとって散布図表示を行っている。図10によれば、全ての測定値が±0.5mm以内におさまっており、信頼性の高い測定結果が得られることがわかる。 FIG. 10 shows a measurement result (according to the present invention) by the apparatus of the first embodiment shown in FIG. In FIG. 10, the horizontal axis represents the nugget diameter obtained as a result of the cutting test, and the vertical axis represents the nugget diameter obtained by the method of the present invention to display a scatter diagram. According to FIG. 10, it can be seen that all the measured values are within ± 0.5 mm, and a highly reliable measurement result is obtained.

従来技術との対比のために、本発明の方法と特許文献6に示された方法との間で測定時間の対比を行った。本発明の方法では、1つのサンプル当たりの測定時間が平均3.5秒であったのに対し、特許文献6に示された方法では、本発明による装置と同程度の測定精度を得るのに必要な1つのサンプル当たりの測定時間が平均約30秒であった。特許文献6に示された方法では、超音波探触子と溶接凝固組織との位置合わせが短時間では行えないことなどから測定時間が長くなった。特許文献6は短い測定時間が求められる現場でのスポット溶接部健全性評価に適用しにくいことが改めて明らかとなった。本実施形態の装置を用いることにより、短時間で精度が良いスポット溶接部健全性評価を行うことが可能である。さらに、また、図9の表示によれば、超音波探触子10および超音波探触子20とナゲットとの位置関係をはっきり把握できるため、作業者が安心して測定作業をおこなうことができる。   For comparison with the prior art, the measurement time was compared between the method of the present invention and the method disclosed in Patent Document 6. In the method of the present invention, the measurement time per sample averaged 3.5 seconds, whereas in the method disclosed in Patent Document 6, measurement accuracy comparable to that of the apparatus according to the present invention was obtained. The required measurement time per sample averaged about 30 seconds. In the method disclosed in Patent Document 6, the measurement time is long because the ultrasonic probe and the welded solidified structure cannot be aligned in a short time. It has been clarified again that Patent Document 6 is difficult to apply to spot welded part soundness evaluation in the field where a short measurement time is required. By using the apparatus of this embodiment, it is possible to perform a spot welded portion soundness evaluation with good accuracy in a short time. Furthermore, according to the display of FIG. 9, since the positional relationship between the ultrasonic probe 10 and the ultrasonic probe 20 and the nugget can be clearly grasped, the operator can perform the measurement work with peace of mind.

図11は第1参考例を実施するための装置の例を示している。以下、図7と共通する部分は説明を省略する。この装置は、ゲート手段31によって取り出された受波超音波の信号から超音波の振幅を検出するピーク値検出手段33を用いる点が図7の装置とは異なる。なお、超音波送受信器30によって増幅された信号をA/D変換し、ソフトウェアによって、ディジタル化された信号から被検体の表面沿いに伝搬する超音波の振幅を検出するようにゲート手段31およびピーク値検出手段33を構成することもできる。 FIG. 11 shows an example of an apparatus for carrying out the first reference example . Hereinafter, the description of the parts common to FIG. 7 will be omitted. This apparatus is different from the apparatus shown in FIG. 7 in that peak value detection means 33 for detecting the amplitude of the ultrasonic wave from the received ultrasonic wave signal extracted by the gate means 31 is used. The signal amplified by the ultrasonic transmitter / receiver 30 is A / D converted, and the gate means 31 and the peak are detected by software so that the amplitude of the ultrasonic wave propagating along the surface of the subject is detected from the digitized signal. The value detection means 33 can also be configured.

図11に示した第1参考例の装置において、超音波探触子10及び20のクサビ材12、22をポリスチロールとし、振動子アレイ11〜1116及び21〜2116のアレイ配列方向における振動子の幅を0.8mm、超音波の上板表面への入射角が34.7°となるようにしてスポット溶接部2の測定を実施した。測定の対象として板厚2.6mmの2枚の鋼板を重ねてスポット溶接して作製された30個のサンプルを用いた。また、スポット溶接部がない板厚2.6mmの平坦な鋼板へ超音波探触子10及び超音波探触子20を向かい合わせて当接させ、超音波探触子10の振動子アレイ11〜1116から送波された超音波を、超音波探触子20の振動子アレイ21〜2116によって受波した場合の受波超音波の振幅を基準(基準振幅)として用いた。受波超音波の振幅と基準振幅とを比較し、(受波超音波の振幅/基準振幅)がしきい値(本例では−6dB)を下回らない場合には、受波超音波がその伝搬経路に溶融凝固組織2bを含まないと判定するようにした。ナゲット径の測定では、図5と同様に、振動子アレイ11〜1116と振動子アレイ21〜2116との超音波伝搬経路のうち、溶融凝固組織2bを含まない超音波の伝搬経路を求め、交錯した実線に囲まれた内側の領域のアレイ配列方向での長さを求めた。一例を図12に示す。また、溶融凝固組織2bの存在をわかりやすく表示するため、図13に示す2次元表示を行った。2次元表示の方法は図9を用いて説明したものと同等である。なお、図13は図12に示した例の2次元表示である。図12〜図13に示した例ではナゲットが送波を行う振動子アレイ11〜1116に近く位置している。 In the apparatus of the first reference example shown in FIG. 11, the wedge members 12 and 22 of the ultrasonic probes 10 and 20 are made of polystyrene, and the array arrangement directions of the transducer arrays 11 1 to 11 16 and 21 1 to 21 16 are arranged. The spot welded portion 2 was measured so that the width of the vibrator was 0.8 mm and the incident angle of the ultrasonic wave on the upper plate surface was 34.7 °. Thirty samples prepared by stacking two steel plates having a thickness of 2.6 mm and spot welding were used as measurement targets. Further, the ultrasonic probe 10 and the ultrasonic probe 20 are brought into contact with each other on a flat steel plate having a thickness of 2.6 mm without a spot welded portion, and the transducer array 11 1 of the ultrasonic probe 10 is contacted. the ultrasonic wave transmitted from to 11 16, with the amplitude of the reception ultrasonic wave in the case of reception by the transducer array 21 1 to 21 16 of the ultrasonic probe 20 as a reference (reference amplitude). The amplitude of the received ultrasonic wave is compared with the reference amplitude, and if (the amplitude of the received ultrasonic wave / reference amplitude) does not fall below the threshold value (−6 dB in this example), the received ultrasonic wave is propagated. It was determined that the molten solidified structure 2b was not included in the path. In the measurement of the nugget diameter, in the same way as in FIG. 5, among the ultrasonic propagation paths of the transducer arrays 11 1 to 11 16 and the transducer arrays 21 1 to 21 16 , the propagation path of the ultrasonic waves that do not include the molten solidified tissue 2 b. And the length in the array arrangement direction of the inner region surrounded by the intersecting solid lines was obtained. An example is shown in FIG. Further, in order to display the presence of the melt-solidified structure 2b in an easy-to-understand manner, the two-dimensional display shown in FIG. 13 was performed. The two-dimensional display method is the same as that described with reference to FIG. FIG. 13 is a two-dimensional display of the example shown in FIG. In the example shown in FIGS. 12 to 13, the nugget is located close to the transducer arrays 11 1 to 11 16 that transmit the waves.

図11に示した第1参考例の装置による測定結果を図14に示す。図14では、横軸に切断試験の結果求められたナゲット径をとり、縦軸に第1参考例の方法により求められたナゲット径をとって散布図表示を行っている。図14によれば、全ての測定値が±0.5mm以内におさまっており、信頼性の高い測定結果が得られることがわかる。 The first device by that measurement results of the reference example shown in FIG. 11 is shown in FIG. 14. In FIG. 14, the horizontal axis represents the nugget diameter obtained as a result of the cutting test, and the vertical axis represents the nugget diameter obtained by the method of the first reference example , and the scatter diagram is displayed. According to FIG. 14, all measured values are within ± 0.5 mm, and it can be seen that highly reliable measurement results can be obtained.

従来技術との対比のために、第1参考例の方法と特許文献6に示された方法との間で測定時間の対比を行った。第1参考例の方法では、1つのサンプル当たりの測定時間が平均3.5秒であったのに対し、特許文献6に示された方法では、第1参考例による装置と同程度の測定精度を得るのに必要な1つのサンプル当たりの測定時間が平均約30秒であった。特許文献6に示された方法では、超音波探触子と溶接凝固組織との位置合わせが短時間では行えないことなどから測定時間が長くなった。特許文献6は短い測定時間が求められる現場でのスポット溶接部健全性評価に適用しにくいことが改めて明らかとなった。第1参考例の装置を用いることにより、短時間で精度が良いスポット溶接部健全性評価を行うことが可能である。さらに、また、図13の表示によれば、超音波探触子10および超音波探触子20とナゲットとの位置関係をはっきり把握できるため、作業者が安心して測定作業をおこなうことができる。 For comparison with the prior art, the measurement time was compared between the method of the first reference example and the method disclosed in Patent Document 6. In the method of the first reference example, the average measurement time per sample was 3.5 seconds, whereas in the method shown in Patent Document 6, the measurement accuracy was comparable to that of the apparatus according to the first reference example. The average measurement time per sample necessary to obtain the value was about 30 seconds. In the method disclosed in Patent Document 6, the measurement time is long because the ultrasonic probe and the welded solidified structure cannot be aligned in a short time. It has been clarified again that Patent Document 6 is difficult to apply to spot welded part soundness evaluation in the field where a short measurement time is required. By using the apparatus of the first reference example , it is possible to perform a spot welded portion soundness evaluation with high accuracy in a short time. Furthermore, according to the display of FIG. 13, since the positional relationship between the ultrasonic probe 10, the ultrasonic probe 20, and the nugget can be clearly grasped, the operator can perform measurement work with peace of mind.

以下、図面を参照して第2参考例、本発明の第2実施形態を説明する。第2実施形態が請求項2、請求項に対応する。第1参考例、第実施形態と共通する部分は説明を省略する。 Hereinafter, a second reference example and a second embodiment of the present invention will be described with reference to the drawings. The second embodiment corresponds to claims 2 and 4 . Descriptions of parts common to the first reference example and the first embodiment are omitted.

れら第2参考例、実施形態では、振動子アレイ11を備えた超音波探触子10と振動子アレイ21を備えた超音波探触子20とによって、図15に示す平面経路(金属板の上面からみた経路)を伝搬した超音波を受波する。この伝搬経路は、受波用振動子アレイの各振動子に対して正対する送波用振動子アレイの各振動子に加え、隣接するどちらかの送波用振動子から送波された超音波を受波するものである。振動子アレイ11の振動子11i(i=1、2、‥、8)が送波した超音波を振動子アレイ21の振動子21iおよび21i+1(i=1、2、‥、8)を用いて受波すること、および振動子アレイ11の振動子21i(i=9、10、‥、16)が送波した超音波を振動子アレイ21の振動子21i−1および21i(i=9、10、‥、16)を用いて受波することにより、斜めに伝搬する伝搬経路が増え、伝搬経路の中間位置では、アレイ配列方向にみて振動子アレイの幅の1/2おきに超音波の伝搬経路が並ぶため、見かけ上、半分の幅の振動子を2倍の個数配列したのと同等の効果がある。 These second reference example, in the second embodiment, by the ultrasonic probe 20 provided with an ultrasonic probe 10 having a transducer array 11 transducer array 21, planar path shown in FIG. 15 It receives the ultrasonic wave that has propagated through (the path seen from the top surface of the metal plate). In addition to each transducer of the transmitting transducer array that directly faces each transducer of the receiving transducer array, this propagation path includes ultrasonic waves transmitted from one of the adjacent transducers for transmitting. Is received. The ultrasonic waves transmitted by the transducers 11 i (i = 1, 2,..., 8) of the transducer array 11 are converted into the transducers 21 i and 21 i + 1 (i = 1, 2,..., 8) of the transducer array 21. , And the ultrasonic waves transmitted by the transducers 21 i (i = 9, 10,..., 16) of the transducer array 11 are transducers 21 i-1 and 21 i of the transducer array 21. By receiving using (i = 9, 10,..., 16), the number of propagation paths that propagate obliquely increases, and at an intermediate position of the propagation path, ½ of the width of the transducer array in the array arrangement direction. Since the ultrasonic wave propagation paths are arranged every other time, it is apparently the same effect as arranging twice the number of transducers having a half width.

図15に示した前記伝搬経路に溶融凝固組織2bが含まれれば、受波超音波の振幅や伝達時間が変化することは既に述べたとおりである。   If the molten solidified structure 2b is included in the propagation path shown in FIG. 15, the amplitude and transmission time of the received ultrasonic wave change as described above.

図16は、板厚2.6mmの2枚の鋼板を重ねてスポット溶接を行ったサンプルに、前記したように超音波探触子10及び超音波探触子20をスポット溶接部2を挟んで向かい合わせて当接させ、超音波探触子10の振動子11〜1116から送波された超音波のうち、図15に示した伝搬経路の超音波を超音波探触子20の振動子21〜2116によって受波した後、受波超音波の形態を基準と比較し、前記受波超音波の形態が基準と異なる受波超音波を選別して表示した結果である(図16において□を用いて表示)。ここで、受波超音波の形態としてはその振幅を用いた。また、スポット溶接部がない板厚2.6mmの平坦な鋼板へ超音波探触子10及び超音波探触子20を向かい合わせて当接させ、超音波探触子10の振動子11〜1116から送波された超音波を、超音波探触子20の振動子21〜2116によって受波した場合の受波超音波の振幅を基準として用いた。具体的には、図15に示した経路に順にP〜P31の符号をつけて、符号順に(受波超音波の振幅/基準の振幅)を求め、補間を行うことにより図16に示す振幅プロフィルを作成した。この振幅プロフィルが所定のしきい値Ta(ここでは基準振幅に対し−6dBを用いた)を下回る部分が受波超音波の形態が基準と異なるとして、その幅Waを求めた。前記幅Waが受波超音波の形態が基準と異なる経路の存在範囲であるから、前記幅Waはナゲット径といえる。 FIG. 16 shows that the ultrasonic probe 10 and the ultrasonic probe 20 are sandwiched between the spot welded portions 2 as described above on a sample obtained by spot welding with two steel plates having a thickness of 2.6 mm. Of the ultrasonic waves transmitted from the transducers 11 1 to 11 16 of the ultrasonic probe 10 so as to face each other, the ultrasonic wave of the propagation path shown in FIG. After receiving by the sub-elements 21 1 to 21 16 , the received ultrasonic wave form is compared with the reference, and the received ultrasonic wave whose form is different from the reference is selected and displayed (see FIG. 16 is displayed using □). Here, the amplitude was used as the form of the received ultrasonic wave. In addition, the ultrasonic probe 10 and the ultrasonic probe 20 are brought into contact with each other on a flat steel plate having a thickness of 2.6 mm that does not have a spot weld, and the transducers 11 1 to 11 of the ultrasonic probe 10 are brought into contact with each other. the ultrasonic wave transmitted from the 11 16 was used as a reference amplitude wave receiving ultrasound in the case of reception by the transducer 21 1 to 21 16 of the ultrasonic probe 20. Specifically, the codes P 1 to P 31 are sequentially added to the path shown in FIG. 15 to obtain (the amplitude of the received ultrasonic wave / the reference amplitude) in the order of the codes, and the interpolation is performed as shown in FIG. An amplitude profile was created. The width Wa of the portion where the amplitude profile falls below a predetermined threshold value Ta (here, −6 dB with respect to the reference amplitude) is different from the reference, and the width Wa is obtained. Since the width Wa is an existing range of a path whose received ultrasonic wave form is different from the reference, the width Wa can be said to be a nugget diameter.

図17は第2参考例を実施するための装置の例を示している。以下、第1参考例と共通する部分は説明を省略する。 FIG. 17 shows an example of an apparatus for carrying out the second reference example . Hereinafter, the description of the parts common to the first reference example will be omitted.

図17に示した第2参考例の装置において、超音波探触子10及び20のクサビ材12、22をポリスチロールとし、振動子アレイ11〜1116及び21〜2116のアレイ配列方向における振動子の幅を0.8mm、超音波の上板表面への入射角が34.7°となるようにしてスポット溶接部2の測定を実施した。受波超音波の伝搬経路は図15に示したものとした。測定の対象として板厚2.6mmの2枚の鋼板を重ねてスポット溶接して作製された30個のサンプルを用いた。また、スポット溶接部がない板厚2.6mmの平坦な鋼板へ超音波探触子10及び超音波探触子20を向かい合わせて当接させ、超音波探触子10の振動子アレイ11〜1116から送波された超音波を、超音波探触子20の振動子アレイ21〜2116によって受波した場合の受波超音波の振幅を基準(基準振幅)として用いた。受波超音波の振幅と基準振幅とを比較し、(受波超音波の振幅/基準振幅)がしきい値(本例では−6dB)を下回る場合には、受波超音波がその伝搬経路に溶融凝固組織2bを含むと判定するようにした。ナゲット径の測定では、図16を用いて説明した方法を用いた。なお、(受波超音波の振幅/基準振幅)の演算を行う代わりに、各伝搬経路における基準振幅が一定となるように、超音波送受信器30における増幅度を伝搬経路ごとに変更すると、受波超音波の振幅そのものとしきい値Taとを比較できる。また、超音波送受信器30によって増幅された信号をA/D変換し、ソフトウェアによって、ディジタル化された信号から被検体の表面沿いに伝搬する超音波の振幅を検出するようにゲート手段31およびピーク値検出手段33を構成する場合には、各伝搬経路における基準振幅が一定となるようにディジタル化された受波超音波に所定の係数を掛け算するようにすると、受波超音波の振幅そのものとしきい値Taとを比較できる。 In the apparatus of the second reference example shown in FIG. 17, the wedge members 12 and 22 of the ultrasonic probes 10 and 20 are made of polystyrene, and the array directions of the transducer arrays 11 1 to 11 16 and 21 1 to 21 16 are arranged. The spot welded portion 2 was measured so that the width of the vibrator was 0.8 mm and the incident angle of the ultrasonic wave on the upper plate surface was 34.7 °. The propagation path of the received ultrasonic wave is as shown in FIG. Thirty samples prepared by stacking two steel plates having a thickness of 2.6 mm and spot welding were used as measurement targets. Further, the ultrasonic probe 10 and the ultrasonic probe 20 are brought into contact with each other on a flat steel plate having a thickness of 2.6 mm without a spot welded portion, and the transducer array 11 1 of the ultrasonic probe 10 is contacted. the ultrasonic wave transmitted from to 11 16, with the amplitude of the reception ultrasonic wave in the case of reception by the transducer array 21 1 to 21 16 of the ultrasonic probe 20 as a reference (reference amplitude). When the amplitude of the received ultrasonic wave is compared with the reference amplitude, and (the amplitude of the received ultrasonic wave / reference amplitude) is lower than the threshold value (−6 dB in this example), the received ultrasonic wave has its propagation path. Is determined to contain the melt-solidified structure 2b. In the measurement of the nugget diameter, the method described with reference to FIG. 16 was used. Instead of calculating (the amplitude of the received ultrasonic wave / the reference amplitude), if the amplification degree in the ultrasonic transmitter / receiver 30 is changed for each propagation path so that the reference amplitude in each propagation path is constant, it is received. The amplitude of the wave ultrasonic wave itself can be compared with the threshold value Ta. The signal amplified by the ultrasonic transceiver 30 is A / D converted, and the gate means 31 and the peak are detected by software so that the amplitude of the ultrasonic wave propagating along the surface of the subject is detected from the digitized signal. In the case of configuring the value detection means 33, if the received ultrasonic wave digitized so that the reference amplitude in each propagation path is constant is multiplied by a predetermined coefficient, the amplitude of the received ultrasonic wave itself is obtained. The threshold value Ta can be compared.

図17に示した第2参考例の装置による測定結果を図18に示す。図18では、横軸に切断試験の結果求められたナゲット径をとり、縦軸に第2参考例の方法により求められたナゲット径をとって散布図表示を行っている。図18によれば、全ての測定値が±0.5mm以内におさまっており、信頼性の高い測定結果が得られることがわかる。 The second reference example device by that measurement results of that shown in FIG. 17 is shown in FIG. 18. In FIG. 18, the horizontal axis represents the nugget diameter obtained as a result of the cutting test, and the vertical axis represents the nugget diameter obtained by the method of the second reference example , and the scatter diagram is displayed. As can be seen from FIG. 18, all the measured values are within ± 0.5 mm, and a highly reliable measurement result is obtained.

従来技術との対比のために、第2参考例の方法と特許文献6に示された方法との間で測定時間の対比を行った。第2参考例の方法では、1つのサンプル当たりの測定時間が平均3.5秒であったのに対し、特許文献6に示された方法では、第2参考例による装置と同程度の測定精度を得るのに必要な1つのサンプル当たりの測定時間が平均約30秒であった。特許文献6に示された方法では、超音波探触子と溶接凝固組織との位置合わせが短時間では行えないことなどから測定時間が長くなった。特許文献6は短い測定時間が求められる現場でのスポット溶接部健全性評価に適用しにくいことが改めて明らかとなった。第2参考例の装置を用いることにより、短時間で精度が良いスポット溶接部健全性評価を行うことが可能である。 For comparison with the prior art, the measurement time was compared between the method of the second reference example and the method disclosed in Patent Document 6. In the method of the second reference example , the measurement time per sample was an average of 3.5 seconds, whereas in the method shown in Patent Document 6, the measurement accuracy was comparable to that of the apparatus according to the second reference example. The average measurement time per sample necessary to obtain the value was about 30 seconds. In the method disclosed in Patent Document 6, the measurement time is long because the ultrasonic probe and the welded solidified structure cannot be aligned in a short time. It has been clarified again that Patent Document 6 is difficult to apply to spot welded part soundness evaluation in the field where a short measurement time is required. By using the apparatus of the second reference example , it is possible to perform a spot welded portion soundness evaluation with high accuracy in a short time.

次に、第2参考例の別例である第実施形態の装置を説明する。図19は基準と比較する受波超音波の形態として伝達時間を用いて、前記複数の送波位置と前記複数の受波位置とを結ぶ伝搬経路の各々において、受波された超音波の形態を基準と比較し、前記伝搬経路の中からナゲットが存在する伝搬経路を抽出し、該抽出されたナゲットが存在する伝搬経路の存在範囲に基づいてナゲット径を算出する装置の例を示している。以下、第実施形態と共通する部分は説明を省略する。 Next, the apparatus of 2nd Embodiment which is another example of a 2nd reference example is demonstrated. FIG. 19 shows the form of ultrasonic waves received in each of the propagation paths connecting the plurality of transmission positions and the plurality of reception positions, using transmission time as the form of the reception ultrasonic waves compared with the reference. Shows an example of a device that extracts a propagation path in which a nugget exists from the propagation paths and calculates a nugget diameter based on the existence range of the propagation path in which the extracted nugget exists. . Hereinafter, description of parts common to the first embodiment will be omitted.

図19に示した第実施形態の装置において、超音波探触子10及び20のクサビ材12、22をポリスチロールとし、振動子アレイ11〜1116及び21〜2116のアレイ配列方向における振動子の幅を0.8mm、超音波の上板表面への入射角が34.7°となるようにしてスポット溶接部2の測定を実施した。受波超音波の伝搬経路は図15に示したものとした。測定の対象として板厚2.6mmの2枚の鋼板を重ねてスポット溶接して作製された30個のサンプルを用いた。また、スポット溶接部がない板厚2.6mmの平坦な鋼板へ超音波探触子10及び超音波探触子20を向かい合わせて当接させ、超音波探触子10の振動子アレイ11〜1116から送波された超音波を、超音波探触子20の振動子アレイ21〜2116によって受波した場合の受波超音波の伝達時間を基準(基準伝達時間)として用いた。受波超音波の伝達時間と基準伝達時間とを比較し、(|受波超音波の伝達時間−基準伝達時間|/基準伝達時間)がしきい値Tt(本例では0.5%)以上である場合には、受波超音波がその伝搬経路に溶融凝固組織2bを含むと判定するようにした(図20において□にて表示)。ナゲット径の測定では、図20に一例を示すように、図15に示した経路に順にP〜P31の符号をつけて、符号順に(|受波超音波の伝達時間−基準伝達時間|/基準伝達時間)を求め、補間を行うことにより図20に示す伝達時間プロフィルを作成した。この伝達時間プロフィルが所定の上記しきい値Ttを上回る部分の幅Wtを求めた。 In the apparatus of the second embodiment shown in FIG. 19, the wedge members 12 and 22 of the ultrasonic probes 10 and 20 are made of polystyrene, and the array arrangement directions of the transducer arrays 11 1 to 11 16 and 21 1 to 21 16 are arranged. The spot welded portion 2 was measured so that the width of the vibrator was 0.8 mm and the incident angle of the ultrasonic wave on the upper plate surface was 34.7 °. The propagation path of the received ultrasonic wave is as shown in FIG. Thirty samples prepared by stacking two steel plates having a thickness of 2.6 mm and spot welding were used as measurement targets. Further, the ultrasonic probe 10 and the ultrasonic probe 20 are brought into contact with each other on a flat steel plate having a thickness of 2.6 mm without a spot welded portion, and the transducer array 11 1 of the ultrasonic probe 10 is contacted. the ultrasonic wave transmitted from to 11 16, with transmission time of the reception ultrasonic wave in the case of reception by the transducer array 21 1 to 21 16 of the ultrasonic probe 20 as a reference (reference transmission time) . The transmission time of the received ultrasonic wave is compared with the reference transmission time, and (| received ultrasonic wave transmission time−reference transmission time | / reference transmission time) is equal to or greater than the threshold value Tt (0.5% in this example). In this case, it is determined that the received ultrasonic wave includes the molten and solidified structure 2b in the propagation path (indicated by a square in FIG. 20). In the measurement of the nugget diameter, as shown in FIG. 20, for example, the paths P 1 to P 31 are sequentially added to the path shown in FIG. 15, and the received ultrasonic wave transmission time-reference transmission time | / Reference transmission time) was obtained, and the transmission time profile shown in FIG. 20 was created by performing interpolation. The width Wt of the portion where the transmission time profile exceeds the predetermined threshold value Tt was obtained.

図19に示した第実施形態の装置による(本発明による)測定結果を図21に示す。図21では、横軸に切断試験の結果求められたナゲット径をとり、縦軸に本発明の方法により求められたナゲット径をとって散布図表示を行っている。図21によれば、全ての測定値が±0.5mm以内におさまっており、信頼性の高い測定結果が得られることがわかる。 FIG. 21 shows a measurement result (according to the present invention) by the apparatus of the second embodiment shown in FIG. In FIG. 21, the horizontal axis represents the nugget diameter obtained as a result of the cutting test, and the vertical axis represents the nugget diameter obtained by the method of the present invention to display a scatter diagram. According to FIG. 21, it can be seen that all the measured values are within ± 0.5 mm, and a highly reliable measurement result is obtained.

従来技術との対比のために、本発明の方法と特許文献6に示された方法との間で測定時間の対比を行った。本発明の方法では、1つのサンプル当たりの測定時間が平均3.5秒であったのに対し、特許文献6に示された方法では、本発明による装置と同程度の測定精度を得るのに必要な1つのサンプル当たりの測定時間が平均約30秒であった。特許文献6に示された方法では、超音波探触子と溶接凝固組織との位置合わせが短時間では行えないことなどから測定時間が長くなった。特許文献6は短い測定時間が求められる現場でのスポット溶接部健全性評価に適用しにくいことが改めて明らかとなった。第実施形態の装置を用いることにより、短時間で精度が良いスポット溶接部健全性評価を行うことが可能である。 For comparison with the prior art, the measurement time was compared between the method of the present invention and the method disclosed in Patent Document 6. In the method of the present invention, the measurement time per sample averaged 3.5 seconds, whereas in the method disclosed in Patent Document 6, measurement accuracy comparable to that of the apparatus according to the present invention was obtained. The required measurement time per sample averaged about 30 seconds. In the method disclosed in Patent Document 6, the measurement time is long because the ultrasonic probe and the welded solidified structure cannot be aligned in a short time. It has been clarified again that Patent Document 6 is difficult to apply to spot welded part soundness evaluation in the field where a short measurement time is required. By using the apparatus of the second embodiment, it is possible to perform spot welded portion soundness evaluation with high accuracy in a short time.

以上の実施形態や参考例の説明では、受波超音波の伝搬経路に溶融凝固組織2bを含むか否かの判定に用いる受波超音波の形態として、超音波の振幅を用いる例、超音波の伝達時間を用いる例を別々に説明したが、両者を組み合わせて溶融凝固組織2bを含むか否かの判定を行うことも、勿論、可能である。また、受波超音波の形態として、上記のほかに、パルス幅、周波数、位相などを用いることが可能である。 In the description of the above embodiment and reference examples, an example in which the amplitude of ultrasonic waves is used as the form of received ultrasonic waves used for determining whether or not the melted solidified tissue 2b is included in the propagation path of the received ultrasonic waves, ultrasonic waves However, it is of course possible to determine whether or not the melted and solidified structure 2b is included by combining the two. In addition to the above, a pulse width, a frequency, a phase, and the like can be used as a form of received ultrasonic waves.

なお、振動子アレイ11〜11及び21〜21のアレイ配列方向における振動子の幅を小さくすることによって、測定精度を更に高めることができる。振動子アレイ11〜11及び21〜21のアレイ配列方向における振動子の幅は、必要とされる測定精度に応じて決めるとよい。 Note that the measurement accuracy can be further increased by reducing the width of the transducers in the array arrangement direction of the transducer arrays 11 1 to 11 N and 21 1 to 21 N. The width of the transducers in the array arrangement direction of the transducer arrays 11 1 to 11 N and 21 1 to 21 N may be determined according to the required measurement accuracy.

本実施形態においては、送波側、受波側、共に振動子アレイを備えた超音波探触子を用いているので、構成が簡略である。なお、いずれか一方、又は、両方に、複数の探触子を並置して用いたり、又は、単一の探触子を走査して用いることも可能である。   In this embodiment, since the ultrasonic probe provided with the transducer array is used on both the transmission side and the reception side, the configuration is simple. In addition, it is also possible to use a plurality of probes juxtaposed on either one or both, or to scan and use a single probe.

さらに、以上の説明においては、本発明が金属板の溶接検査に適用されていたが、本発明の適用対象は、これに限定されない。又、溶接枚数も2枚に限定されず、スポット溶接部の健全性の評価も、ナゲット径のみを測定するものに限定されない。   Furthermore, in the above description, the present invention is applied to the welding inspection of the metal plate, but the application target of the present invention is not limited to this. Further, the number of welds is not limited to two, and the evaluation of the soundness of the spot welded portion is not limited to the one that measures only the nugget diameter.

本発明の実施形態の基本構成を示す斜視図The perspective view which shows the basic composition of embodiment of this invention 第1参考例、本発明の第1実施形態の原理を説明するための、超音波の伝搬経路を示す断面図Sectional drawing which shows the propagation path of an ultrasonic wave for demonstrating the principle of 1st reference example and 1st Embodiment of this invention 同じく平面図Same top view スポット溶接部の断面図Cross section of spot weld 第1参考例における溶融凝固組織を含まない超音波伝搬経路とナゲットとの関係を示す説明図Explanatory drawing which shows the relationship between the ultrasonic propagation path | route and the nugget which do not contain the melt solidification structure | tissue in a 1st reference example . 本発明の第実施形態における溶融凝固組織を含まない超音波伝搬経路とナゲットとの関係を示す説明図Explanatory drawing which shows the relationship between the ultrasonic propagation path | route and the nugget which do not contain the melt solidification structure | tissue in 1st Embodiment of this invention. 本発明の第実施形態を実施するための装置の例を示す一部ブロック図を含む斜視図The perspective view including the partial block diagram which shows the example of the apparatus for implementing 1st Embodiment of this invention 実施形態の装置による測定結果の一例を示す説明図Explanatory drawing which shows an example of the measurement result by the apparatus of 1st Embodiment 同じく測定結果表示の一例を示す説明図Explanatory drawing which similarly shows an example of a measurement result display 本発明法による測定結果の精度を示す線図Diagram showing the accuracy of measurement results according to the method of the present invention 第1参考例を実施するための装置の例を示す一部ブロック図を含む斜視図 The perspective view including the partial block diagram which shows the example of the apparatus for implementing a 1st reference example 第1参考例の装置による測定結果の一例を示す説明図Explanatory drawing which shows an example of the measurement result by the apparatus of the first reference example 同じく測定結果表示の一例を示す説明図Explanatory drawing which similarly shows an example of a measurement result display 同じく測定結果の精度を示す線図Diagram showing the accuracy of measurement results 第2参考例、本発明の第2実施形態の原理を説明するための、超音波の伝搬経路を示す平面図A plan view showing a propagation path of ultrasonic waves for explaining the principle of the second reference example and the second embodiment of the present invention . 同じくナゲット径測定方法の説明図Similarly, an illustration of the nugget diameter measurement method 第2参考例を実施するための装置の例を示す一部ブロック図を含む斜視図 The perspective view including the partial block diagram which shows the example of the apparatus for implementing a 2nd reference example 2参考例の装置による測定結果の精度を示す線図Diagram showing the accuracy of the measurement results by the device of the second reference example 本発明の第実施形態を実施するための装置の例を示す一部ブロック図を含む斜視図The perspective view including the partial block diagram which shows the example of the apparatus for implementing 2nd Embodiment of this invention 実施形態の装置におけるナゲット径測定方法の説明図Explanatory drawing of the nugget diameter measuring method in the apparatus of 2nd Embodiment 同じく測定結果の精度を示す線図Diagram showing the accuracy of measurement results スポット溶接部を解説するための断面図Cross section for explaining spot welds

符号の説明Explanation of symbols

1a、101a…上板
1b、101b…下板
2、102…スポット溶接部
2a、102a…ナゲット
2b…溶融凝固組織
10、20…超音波探触子
11、21…振動子アレイ
25…スイッチ回路
26…スイッチ回路
30…超音波送受信器
31…ゲート手段
32…時間計測手段
33…ピーク値検出手段
DESCRIPTION OF SYMBOLS 1a, 101a ... Upper plate 1b, 101b ... Lower plate 2, 102 ... Spot welding part 2a, 102a ... Nugget 2b ... Melt-solidified structure 10, 20 ... Ultrasonic probe 11, 21 ... Vibrator array
DESCRIPTION OF SYMBOLS 25 ... Switch circuit 26 ... Switch circuit 30 ... Ultrasonic transmitter / receiver 31 ... Gate means 32 ... Time measuring means 33 ... Peak value detection means

Claims (4)

複数の金属板を重ね合わせて溶接してなるスポット溶接部の超音波による評価方法において、金属板またはスポット溶接部の表面沿いの方向と厚さ方向とによって形成される断面内を伝搬する超音波を被検体の表面沿いに伝搬する超音波と称することとしたとき、
スポット溶接部の外側の金属板の複数の送波位置から複数方向へ向けて、被検体の表面沿いに伝搬する超音波を、振動子アレイを備えた超音波探触子により送波し、
スポット溶接部の外側の金属板の複数の受波位置において、伝搬経路にスポット溶接部を含まない被検体の表面沿いに伝搬してきた超音波、及び伝搬経路にスポット溶接部を含む被検体の表面沿いに伝搬してきた超音波を、振動子アレイを備えた超音波探触子により受波し、
前記複数の送波位置と前記複数の受波位置とを結ぶ伝搬経路の各々において、受波された受波超音波の伝達時間を基準伝達時間と比較し、(|受波超音波の伝達時間−基準伝達時間|/基準伝達時間)がしきい値以下である場合には、受波超音波がその伝搬経路にナゲットを含まないと判定し、前記伝搬経路の中からナゲットが存在しない伝搬経路を抽出し、該抽出されたナゲットが存在しない伝搬経路によって囲まれる領域に基づいてナゲット径を算出することを特徴とする超音波によるスポット溶接部の評価方法。
Ultrasonic wave propagating in the cross-section formed by the direction along the surface of the metal plate or spot weld and the thickness direction in the ultrasonic evaluation method for spot welds formed by superposing and welding a plurality of metal plates Is referred to as ultrasound propagating along the surface of the subject,
The ultrasonic wave propagating along the surface of the subject from multiple wave transmission positions of the metal plate outside the spot welded portion in multiple directions is transmitted by an ultrasonic probe equipped with a transducer array,
Ultrasound propagated along the surface of the subject not including the spot weld in the propagation path at the plurality of receiving positions of the metal plate outside the spot weld, and the surface of the subject including the spot weld in the propagation path The ultrasonic wave propagating along the surface is received by an ultrasonic probe equipped with a transducer array,
In each of the propagation paths connecting the plurality of transmission positions and the plurality of reception positions, the transmission time of the received ultrasonic waves received is compared with the reference transmission time, and the (| −reference transmission time | / reference transmission time) is equal to or less than a threshold value, it is determined that the received ultrasonic wave does not include a nugget in the propagation path, and a propagation path in which no nugget exists in the propagation path And the nugget diameter is calculated based on a region surrounded by a propagation path in which the extracted nugget does not exist.
複数の金属板を重ね合わせて溶接してなるスポット溶接部の超音波による評価方法において、金属板またはスポット溶接部の表面沿いの方向と厚さ方向とによって形成される断面内を伝搬する超音波を被検体の表面沿いに伝搬する超音波と称することとしたとき、
スポット溶接部の外側の金属板の複数の送波位置から複数方向へ向けて、被検体の表面沿いに伝搬する超音波を、振動子アレイを備えた超音波探触子により送波し、
スポット溶接部の外側の金属板の複数の受波位置において、伝搬経路にスポット溶接部を含まない被検体の表面沿いに伝搬してきた超音波、及び伝搬経路にスポット溶接部を含む被検体の表面沿いに伝搬してきた超音波を、振動子アレイを備えた超音波探触子により受波し、
前記複数の送波位置と前記複数の受波位置とを結ぶ伝搬経路の各々において、受波された受波超音波の伝達時間を基準伝達時間と比較し、(|受波超音波の伝達時間−基準伝達時間|/基準伝達時間)がしきい値以上である場合には、受波超音波がその伝搬経路にナゲットを含むと判定し、前記伝搬経路の中からナゲットが存在する伝搬経路を抽出し、該抽出されたナゲットが存在する伝搬経路の存在範囲に基づいてナゲット径を算出することを特徴とする超音波によるスポット溶接部の評価方法。
Ultrasonic wave propagating in the cross-section formed by the direction along the surface of the metal plate or spot weld and the thickness direction in the ultrasonic evaluation method for spot welds formed by superposing and welding a plurality of metal plates Is referred to as ultrasound propagating along the surface of the subject,
The ultrasonic wave propagating along the surface of the subject from multiple wave transmission positions of the metal plate outside the spot welded portion in multiple directions is transmitted by an ultrasonic probe equipped with a transducer array,
Ultrasound propagated along the surface of the subject not including the spot weld in the propagation path at the plurality of receiving positions of the metal plate outside the spot weld, and the surface of the subject including the spot weld in the propagation path The ultrasonic wave propagating along the surface is received by an ultrasonic probe equipped with a transducer array,
In each of the propagation paths connecting the plurality of transmission positions and the plurality of reception positions, the transmission time of the received ultrasonic waves received is compared with the reference transmission time, and the (| −reference transmission time | / reference transmission time) is equal to or greater than the threshold value, it is determined that the received ultrasonic wave includes a nugget in the propagation path, and a propagation path in which the nugget exists is selected from the propagation paths. A method for evaluating spot welds by ultrasonic waves, characterized in that the nugget diameter is calculated based on the existence range of the propagation path in which the extracted nugget exists.
複数の金属板を重ね合わせて溶接してなるスポット溶接部の超音波による評価装置において、金属板またはスポット溶接部の表面沿いの方向と厚さ方向とによって形成される断面内を伝搬する超音波を被検体の表面沿いに伝搬する超音波と称することとしたとき、
スポット溶接部の外側の金属板の複数の送波位置から複数方向へ向けて、被検体の表面沿いに伝搬する超音波を送波する、振動子アレイを備えた超音波探触子と、
スポット溶接部の外側の金属板の複数の受波位置において、伝搬経路にスポット溶接部を含まない被検体の表面沿いに伝搬してきた超音波、及び伝搬経路にスポット溶接部を含む被検体の表面沿いに伝搬してきた超音波を受波する、振動子アレイを備えた超音波探触子と、
前記複数の送波位置と前記複数の受波位置とを結ぶ伝搬経路の各々において、受波された受波超音波の伝達時間を基準伝達時間と比較し、(|受波超音波の伝達時間−基準伝達時間|/基準伝達時間)がしきい値以下である場合には、受波超音波がその伝搬経路にナゲットを含まないと判定し、前記伝搬経路の中からナゲットが存在しない伝搬経路を抽出し、該抽出されたナゲットが存在しない伝搬経路に囲まれる領域に基づいてナゲット径を算出する手段と、
を備えたことを特徴とする超音波によるスポット溶接部の評価装置。
Ultrasonic wave propagating in a cross section formed by the direction along the surface and the thickness direction of a metal plate or spot welded part in an ultrasonic evaluation apparatus for spot welded parts formed by superimposing and welding a plurality of metal plates Is referred to as ultrasound propagating along the surface of the subject,
An ultrasonic probe including a transducer array for transmitting ultrasonic waves propagating along the surface of the subject in a plurality of directions from a plurality of transmission positions of a metal plate outside the spot weld,
Ultrasound propagated along the surface of the subject not including the spot weld in the propagation path at the plurality of receiving positions of the metal plate outside the spot weld, and the surface of the subject including the spot weld in the propagation path An ultrasonic probe with a transducer array that receives ultrasonic waves propagating along
In each of the propagation paths connecting the plurality of transmission positions and the plurality of reception positions, the transmission time of the received ultrasonic waves received is compared with the reference transmission time, and the (| −reference transmission time | / reference transmission time) is equal to or less than a threshold value, it is determined that the received ultrasonic wave does not include a nugget in the propagation path, and a propagation path in which no nugget exists in the propagation path Means for calculating a nugget diameter based on a region surrounded by a propagation path in which the extracted nugget does not exist;
An apparatus for evaluating spot welds using ultrasonic waves.
複数の金属板を重ね合わせて溶接してなるスポット溶接部の超音波による評価装置において、金属板またはスポット溶接部の表面沿いの方向と厚さ方向とによって形成される断面内を伝搬する超音波を被検体の表面沿いに伝搬する超音波と称することとしたとき、
スポット溶接部の外側の金属板の複数の送波位置から複数方向へ向けて、被検体の表面沿いに伝搬する超音波を送波する、振動子アレイを備えた超音波探触子と、
スポット溶接部の外側の金属板の複数の受波位置において、伝搬経路にスポット溶接部を含まない被検体の表面沿いに伝搬してきた超音波、及び伝搬経路にスポット溶接部を含む被検体の表面沿いに伝搬してきた超音波を受波する、振動子アレイを備えた超音波探触子と、
前記複数の送波位置と前記複数の受波位置とを結ぶ伝搬経路の各々において、受波された受波超音波の伝達時間を基準伝達時間と比較し、(|受波超音波の伝達時間−基準伝達時間|/基準伝達時間)がしきい値以上である場合には、受波超音波がその伝搬経路にナゲットを含むと判定し、前記伝搬経路の中からナゲットが存在する伝搬経路を抽出し、該抽出されたナゲットが存在する伝搬経路の存在範囲に基づいてナゲット径を算出する手段と、
を備えたことを特徴とする超音波によるスポット溶接部の評価装置。
Ultrasonic wave propagating in a cross section formed by the direction along the surface and the thickness direction of a metal plate or spot welded part in an ultrasonic evaluation apparatus for spot welded parts formed by superimposing and welding a plurality of metal plates Is referred to as ultrasound propagating along the surface of the subject,
An ultrasonic probe including a transducer array for transmitting ultrasonic waves propagating along the surface of the subject in a plurality of directions from a plurality of transmission positions of a metal plate outside the spot weld,
Ultrasound propagated along the surface of the subject not including the spot weld in the propagation path at the plurality of receiving positions of the metal plate outside the spot weld, and the surface of the subject including the spot weld in the propagation path An ultrasonic probe with a transducer array that receives ultrasonic waves propagating along
In each of the propagation paths connecting the plurality of transmission positions and the plurality of reception positions, the transmission time of the received ultrasonic waves received is compared with the reference transmission time, and the (| −reference transmission time | / reference transmission time) is equal to or greater than the threshold value, it is determined that the received ultrasonic wave includes a nugget in the propagation path, and a propagation path in which the nugget exists is selected from the propagation paths. Means for extracting and calculating the nugget diameter based on the existence range of the propagation path in which the extracted nugget exists;
An apparatus for evaluating spot welds using ultrasonic waves.
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Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2004163210A (en) * 2002-11-12 2004-06-10 Jfe Steel Kk Method and apparatus for evaluating spot welded part by ultrasonic wave
JP2006071422A (en) * 2004-09-01 2006-03-16 Jfe Steel Kk Method and apparatus for evaluating spot-welded section by ultrasonic wave

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5828608A (en) * 1981-08-13 1983-02-19 Babcock Hitachi Kk Measuring and display device for shape of deposit
JPH0264451A (en) * 1988-08-31 1990-03-05 Hitachi Ltd Ultrasonic flaw detector
JPH11118771A (en) * 1997-10-20 1999-04-30 Nkk Corp Ultrasonic flaw-detecting method and device of thin plate with plate-thickness change
JP3913144B2 (en) * 2002-08-27 2007-05-09 株式会社日立製作所 Piping inspection method and apparatus
JP4728838B2 (en) * 2006-02-28 2011-07-20 Jfeスチール株式会社 Ultrasonic spot weld evaluation method and apparatus

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2004163210A (en) * 2002-11-12 2004-06-10 Jfe Steel Kk Method and apparatus for evaluating spot welded part by ultrasonic wave
JP2006071422A (en) * 2004-09-01 2006-03-16 Jfe Steel Kk Method and apparatus for evaluating spot-welded section by ultrasonic wave

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