JPH08310B2 - Weld zone diagnosis method during resistance welding - Google Patents
Weld zone diagnosis method during resistance weldingInfo
- Publication number
- JPH08310B2 JPH08310B2 JP3282860A JP28286091A JPH08310B2 JP H08310 B2 JPH08310 B2 JP H08310B2 JP 3282860 A JP3282860 A JP 3282860A JP 28286091 A JP28286091 A JP 28286091A JP H08310 B2 JPH08310 B2 JP H08310B2
- Authority
- JP
- Japan
- Prior art keywords
- welding
- welded
- heat input
- resistance
- abnormality
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
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- Investigating Or Analyzing Materials Using Thermal Means (AREA)
- Investigating Or Analyzing Materials By The Use Of Electric Means (AREA)
Description
【０００１】[0001]
【産業上の利用分野】本発明は、鋼材の抵抗溶接時にお
ける溶接部診断方法に関し、特に電極から被溶接部材へ
の入熱量の異常，すなわち溶接異常の検知と、その異常
原因とを同時に突きとめることができる溶接状態の診断
方法について提案する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for diagnosing a welded portion during resistance welding of a steel material, and more particularly to detecting abnormal heat input from an electrode to a member to be welded, that is, detecting abnormal welding and the cause of the abnormality. We propose a welding method that can be stopped.
【０００２】[0002]
【従来の技術】一般に、シーム溶接等の抵抗溶接は、図
１に示すように、重ね合わせた被溶接材料（母材）の接
合部に抵抗発熱溶融部（ナゲット）を形成し、このナゲ
ットを介して両母材を溶着する方法である。従って、こ
のナゲットの形成状態こそ、溶接強度等の溶接部品質に
大きな影響を及ぼす要因となるものである。それ故に、
ナゲットの形成状態を左右する，いわゆる電極から被溶
接部材への入熱量，すなわち抵抗Ｒ×（電流Ｉ）2 の管
理が、極めて重要である。2. Description of the Related Art Generally, in resistance welding such as seam welding, as shown in FIG. 1, a resistance heat-melting portion (nugget) is formed at a joint portion of materials to be welded (base material) and the nugget is welded. It is a method of welding both base materials through the above. Therefore, the formation state of the nugget is a factor that has a great influence on the welded portion quality such as the welding strength. Therefore,
It is extremely important to control the so-called heat input amount from the electrode to the member to be welded, that is, the resistance R × (current I) 2 that influences the formation state of the nugget.
【０００３】この入熱量を管理する従来技術としては、
特開昭55−139189号公報や特開昭63−203285号公報に開
示されているような方法がある。そのうち、特開昭55−
139189号公報に開示されている技術は、被溶接部材間の
抵抗Ｒを測定し、この測定値を基準抵抗値と比較するこ
とにより、入熱量の異常，ひいては溶接異常を検知する
方法であり、特開昭63−203285号公報に開示されている
技術は、溶接後の溶接部の表面温度を測定し、この測定
値を被溶接部材の重ね厚みによって決定される最適温度
域と比較することによって、入熱量の異常，ひいては溶
接異常を検知する方法である。As a conventional technique for controlling the heat input amount,
There are methods as disclosed in JP-A-55-139189 and JP-A-63-203285. Among them, JP-A-55-
The technique disclosed in Japanese Patent No. 139189 is a method of detecting a resistance R between the members to be welded and comparing the measured value with a reference resistance value to detect an abnormality in heat input amount, and thus an abnormality in welding. The technique disclosed in JP-A-63-203285 measures the surface temperature of the welded portion after welding and compares this measured value with the optimum temperature range determined by the lap thickness of the member to be welded. This is a method for detecting an abnormality in heat input, and by extension, a welding abnormality.
【０００４】[0004]
【発明が解決しようとする課題】しかしながら、特開昭
55−139189号公報に開示されている方法は、被溶接部材
間の抵抗Ｒを測定する方法であるから、例えば、２次側
において電流がリークしているような場合に、この２次
側電流異常を検知することができない。従って、入熱量
の異常，すなわち溶接異常を正確に検知することができ
ないという欠点がある。SUMMARY OF THE INVENTION
The method disclosed in Japanese Patent Publication No. 55-139189 is a method of measuring the resistance R between the members to be welded. Therefore, for example, when the current leaks on the secondary side, the secondary current Abnormality cannot be detected. Therefore, there is a drawback that an abnormality in the heat input amount, that is, a welding abnormality cannot be accurately detected.
【０００５】一方、特開昭63−203285号公報に開示され
ている方法では、入熱量の異常，すなわち溶接異常を検
知することはできるが、この異常が２次側電流Ｉ2 と被
溶接部材間抵抗Ｒのどちらに起因するものであるかを特
定することはできない。On the other hand, with the method disclosed in Japanese Patent Laid-Open No. 63-203285, it is possible to detect an abnormality in the heat input amount, that is, an abnormality in welding, but this abnormality causes the secondary current I 2 and the member to be welded. It is not possible to specify which of the inter-resistance R is the cause.
【０００６】その結果として、溶接ナゲットの形状を適
正なものにコントロールすることが不可能となる。すな
わち、このナゲット形状をブロードにするかシャープに
するかは、投入する電流，抵抗の大きさを調節すること
によって変えなければならないからである。As a result, it becomes impossible to control the shape of the welding nugget to a proper shape. That is, whether the shape of this nugget is broad or sharp must be changed by adjusting the amount of current and resistance to be applied.
【０００７】そこで、本発明は、前記従来技術が抱えて
いる欠点を克服することを目的とし、特に入熱量の異
常，すなわち溶接異常を正確に検知すると共に、この異
常の原因についても、速やかに特定できるような溶接状
態診断技術を提案することにある。[0007] Therefore, the present invention aims to overcome the drawbacks of the above-mentioned prior art, and in particular, accurately detects an abnormality in the heat input amount, that is, a welding abnormality, and promptly detects the cause of this abnormality. It is to propose a welding state diagnosis technology that can be specified.
【０００８】[0008]
【課題を解決するための手段】上記の目的実現のために
鋭意研究した結果、本発明者らは、従来技術のような電
極間抵抗の測定値によることなく、電極間の電圧に着目
し、この電圧測定値から入熱量を算出し、そしてその入
熱量と溶接部表面温度（発熱量）とが図２に示すような
適性範囲をもった比例関係にあるとの知見に基づき、以
下に述べるような本発明方法に想到した。As a result of earnest research for achieving the above-mentioned object, the inventors of the present invention focused on the voltage between electrodes without depending on the measured value of the resistance between electrodes as in the prior art, The amount of heat input is calculated from this voltage measurement value, and the following will be described based on the finding that the amount of heat input and the weld surface temperature (heat generation amount) are in a proportional relationship with an appropriate range as shown in FIG. The method of the present invention has been conceived.
【０００９】すなわち、本発明は、抵抗溶接機を用いて
鋼材を溶接するに当り、電極間に生じる電圧の測定値か
ら溶接部の入熱量を算出すると同時に溶接部の表面温度
を測定し、得られた上記算出値ならびに上記測定値を、
予め設定された溶接部の入熱量Ｑと表面温度Ｔとの最適
関係式Ｔ＝ａＱ±ｂ（ａ，ｂは定数）と比較解析するこ
とにより、Ｔ＜ａＱ−ｂの場合には二次側の電流リーク
に溶接部状態の異常原因があると判断し、Ｔ＞ａＱ＋ｂ
の場合には被溶接部材間の抵抗値上昇に溶接部状態の異
常原因があると判断して、溶接異常の検知とその原因を
特定することを特徴とする抵抗溶接時の溶接部診断方法
である。That is, according to the present invention, when welding a steel material by using a resistance welding machine, the heat input amount of the welded portion is calculated from the measured value of the voltage generated between the electrodes, and at the same time, the surface temperature of the welded portion is measured and obtained. The calculated value and the measured value obtained,
In the case of T <aQ-b, the secondary side is obtained by comparing and analyzing the optimum relational expression T = aQ ± b (a and b are constants) between the heat input Q of the welded portion and the surface temperature T set in advance. It is judged that there is an abnormal cause of the welded state in the current leakage of T, and T> aQ + b
In the case of, the method for diagnosing welded parts during resistance welding is characterized in that it is judged that there is an abnormal cause of the state of the welded part due to an increase in the resistance value between the parts to be welded, and the detection of the welding anomaly and the cause are specified is there.
【００１０】[0010]
【作用】本発明に係る溶接異常の検知方法によれば、ナ
ゲットの形成状態を左右する電極から被溶接部材への入
熱量の異常は、抵抗溶接機の電極間に生じる電圧の測定
値から算出される入熱量と、溶接部表面の温度測定値と
の関係から把握できることを知見し、前記算出値および
測定値を比較演算すれば、正にナゲットの形成状態をオ
ンラインで非破壊的に把握することができる。According to the welding abnormality detecting method of the present invention, the abnormality of the heat input amount from the electrode which influences the formation state of the nugget to the member to be welded is calculated from the measured value of the voltage generated between the electrodes of the resistance welding machine. By knowing that it can be grasped from the relationship between the amount of heat input and the measured value of the temperature of the welded part, and comparing and calculating the calculated value and the measured value, the formation state of the nugget can be accurately grasped nondestructively online. be able to.
【００１１】従って、これらの検出出力に基づいて溶接
部の診断を行うようにすれば、既設装置の改造も必要最
小限ですみ、しかも速やかに溶接異常の検知およびその
原因把握も行うことができるので、溶接精度の向上およ
び製品歩留の向上が図れ、ライン稼動率が大幅に改善さ
れる。Therefore, if the welded portion is diagnosed on the basis of these detection outputs, the existing equipment can be remodeled to the minimum necessary amount, and the welding abnormality and the cause thereof can be promptly detected. Therefore, the welding accuracy and the product yield can be improved, and the line operation rate can be significantly improved.
【００１２】[0012]
【実施例】図３は本発明に係る溶接部診断方法の一実施
例であり、抵抗溶接機の電極間に生じる電圧と、溶接部
の表面温度を測定することによって、溶接部における入
熱量の変動を評価し、溶接部状態の異常検知とその原因
を特定するようにしたシステムの構成図である。EXAMPLE FIG. 3 shows an example of a welded portion diagnosis method according to the present invention. By measuring the voltage generated between the electrodes of a resistance welding machine and the surface temperature of the welded portion, the amount of heat input in the welded portion can be determined. It is a block diagram of the system which evaluated the fluctuation | variation and pinpointed the abnormality detection of a welding part state, and its cause.
【００１３】この図において、溶接部での入熱量Ｑ＝Ｉ
2 Ｒ2は、電圧計５で測定された電極間の電圧を、抵抗
演算回路８で抵抗値Ｒに変換し、その出力を、一次側の
電流値と変圧比から二次電流演算回路７によって算出さ
れる二次電流Ｉ2 の信号と共に入熱量演算回路９に入力
し、オンラインで常時検出するようになっている。In this figure, the heat input Q = I at the welded portion
2 R 2 converts the voltage between the electrodes measured by the voltmeter 5 into a resistance value R by the resistance calculation circuit 8 and outputs the output from the primary side current value and the transformation ratio by the secondary current calculation circuit 7. It is adapted to be input to the heat input amount calculation circuit 9 together with the calculated secondary current I 2 signal for constant online detection.
【００１４】そして、入熱量の検出と同時に、溶接部の
表面温度Ｔは放射温度計６により測定され、この測定値
の出力信号は、上記入熱量演算回路９からの入熱量検出
出力信号と共に、診断器10に入力される。Simultaneously with the detection of the amount of heat input, the surface temperature T of the welded portion is measured by the radiation thermometer 6, and the output signal of this measured value together with the output signal of the amount of heat input from the heat input calculation circuit 9 is detected. Input to the diagnostic device 10.
【００１５】そして最終的に、この診断器10で溶接部状
態の異常検知とその原因の特定が行われ、この解析結果
は、診断器10に接続されている表示器11に出力される。
すなわち、診断器10では、図２に示すようなＴ＝ａＱ±
ｂなる一次式の関係から、ＴとＱの適性範囲Ａを設定し
ておき、この範囲から外れる場合（Ｔ＞ａＱ＋ｂまたは
Ｔ＜ａＱ−ｂ）は、溶接部状態が異常であると判断し、
その原因の特定を行う診断システムになっている。Finally, the diagnostic device 10 detects the abnormality of the welded state and specifies the cause thereof, and the analysis result is output to the display 11 connected to the diagnostic device 10.
That is, in the diagnostic device 10, T = aQ ± as shown in FIG.
From the relationship of the linear expression of b, an appropriate range A of T and Q is set, and if it is out of this range (T> aQ + b or T <aQ-b), it is determined that the welded state is abnormal,
It is a diagnostic system that identifies the cause.
【００１６】ここで、実際に電極間を流れる電流Ｉ′2
は、一次側の電流値と変圧比から算出した二次側電流Ｉ
2 より大きくなることはなく、また、実際の電極間の抵
抗Ｒは、正常時の抵抗Ｒ0 よりも小さくなることはな
い。それ故に、図２において、プロット（ＴとＱの関
係）がＢの領域に外れる場合は、実際の入熱量が不足し
ている（Ｉ′2 ＜Ｉ2）ことから、二次側の電流リーク
に溶接部状態の異常原因があると判断され、一方、プロ
ット（ＴとＱの関係）がＣの領域に外れる場合は、オー
バーヒートにより鋼板の汚れや電極面の荒れなどが起こ
り、抵抗が上昇（Ｒ＞Ｒ0 ）することにその原因がある
と判断される。[0016] Here, the current actually flows through the electrodes I '2
Is the secondary side current I calculated from the primary side current value and the transformation ratio.
It does not become larger than 2 , and the actual resistance R between the electrodes does not become smaller than the normal resistance R 0 . Therefore, in FIG. 2, when the plot (relationship between T and Q) deviates from the region of B, the actual heat input amount is insufficient (I ′ 2 <I 2 ), so that the secondary side current leakage occurs. If it is determined that there is an abnormal cause of the welded part in the area, and if the plot (relationship between T and Q) deviates from the area C, overheating causes stains on the steel plate, roughening of the electrode surface, etc., and resistance increases ( It is judged that the reason is that R> R 0 ).
【００１７】このように、ＴとＱの関係から溶接部状態
の異常が検知されると、上述のような原因の特定が行わ
れ、迅速に異常に対する措置を講じることができる。As described above, when an abnormality in the state of the welded portion is detected from the relationship between T and Q, the cause as described above is specified, and the countermeasure for the abnormality can be promptly taken.
【００１８】[0018]
【発明の効果】以上説明したように、本発明の溶接部診
断方法によれば、溶接強度上重要な作用をもつナゲット
の形成状態を左右する電極から被溶接部材への入熱量の
異常（すなわち溶接部異常）を正確に検知すると共に、
この異常の原因についても、速やかに特定できる。しか
も、これにより、抵抗溶接における溶接破断を未然に防
止することができ、ライン稼動率を大幅に改善すること
が可能となる。As described above, according to the welded portion diagnosing method of the present invention, the heat input from the electrode to the member to be welded, which influences the formation state of the nugget having an important effect on the welding strength, is abnormal (ie, abnormal). Weld part abnormality) is accurately detected,
The cause of this abnormality can be quickly identified. In addition, this makes it possible to prevent welding breakage during resistance welding and to significantly improve the line operation rate.
【図１】抵抗溶接の原理を示す説明図である。FIG. 1 is an explanatory diagram showing the principle of resistance welding.
【図２】入熱量Ｑと溶接部表面温度Ｔの関係を示す図で
ある。FIG. 2 is a diagram showing a relationship between a heat input amount Q and a weld surface temperature T.
【図３】本発明に係る溶接部診断方法の一実施例を示す
システムの構成図である。FIG. 3 is a configuration diagram of a system showing an embodiment of a welded portion diagnosis method according to the present invention.
１ 電極 ２ 被溶接材 ３ ナゲット ４ 電流計 ５ 電圧計 ６ 放射温度計 ７ 二次電流演算回路 ８ 抵抗演算回路 ９ 入熱量演算回路 10 診断器 11 表示器 1 Electrode 2 Welding Material 3 Nugget 4 Ammeter 5 Voltmeter 6 Radiation Thermometer 7 Secondary Current Calculation Circuit 8 Resistance Calculation Circuit 9 Heat Input Calculation Circuit 10 Diagnostic Device 11 Indicator
Claims (1)
り、電極間に生じる電圧の測定値から溶接部の入熱量を
算出すると同時に溶接部の表面温度を測定し、得られた
上記算出値ならびに上記測定値を、予め設定された溶接
部の入熱量Ｑと表面温度Ｔとの最適関係式Ｔ＝ａＱ±ｂ
（ａ，ｂは定数）と比較解析することにより、Ｔ＜ａＱ
−ｂの場合には二次側の電流リークに溶接部状態の異常
原因があると判断し、Ｔ＞ａＱ＋ｂの場合には被溶接部
材間の抵抗値上昇に溶接部状態の異常原因があると判断
して、溶接異常の検知とその原因を特定することを特徴
とする抵抗溶接時の溶接部診断方法。1. When welding a steel material using a resistance welding machine, the heat input of the weld is calculated from the measured value of the voltage generated between the electrodes, and at the same time, the surface temperature of the weld is measured, and the above calculation is obtained. The optimum relational expression T = aQ ± b between the heat input amount Q of the welded portion and the surface temperature T which is set in advance and the above measured value
By comparing and analyzing (a and b are constants) , T <aQ
In the case of -b, the current leak on the secondary side is abnormal and the welded state is abnormal.
If it is determined that there is a cause and T> aQ + b, the welded part
It was determined that there was an abnormal cause of the welded state due to the increase in resistance between materials
Then, a method for diagnosing a weld portion during resistance welding, which is characterized by detecting a welding abnormality and identifying a cause thereof.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3282860A JPH08310B2 (en) | 1991-10-29 | 1991-10-29 | Weld zone diagnosis method during resistance welding |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3282860A JPH08310B2 (en) | 1991-10-29 | 1991-10-29 | Weld zone diagnosis method during resistance welding |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH05115981A JPH05115981A (en) | 1993-05-14 |
| JPH08310B2 true JPH08310B2 (en) | 1996-01-10 |
Family
ID=17658019
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3282860A Expired - Fee Related JPH08310B2 (en) | 1991-10-29 | 1991-10-29 | Weld zone diagnosis method during resistance welding |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH08310B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20260079053A1 (en) | 2022-09-09 | 2026-03-19 | Hioki E.E. Corporation | Resistance measurement device and resistance measurement method |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02229680A (en) * | 1989-03-01 | 1990-09-12 | Nissan Motor Co Ltd | Welding state judging system |
| JPH03207583A (en) * | 1990-01-08 | 1991-09-10 | Matsushita Electric Ind Co Ltd | Method for controlling resistance welding machine |
| JPH03226384A (en) * | 1990-01-30 | 1991-10-07 | Ryoda Sato | Welding monitoring device for resistance welding machine |
-
1991
- 1991-10-29 JP JP3282860A patent/JPH08310B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH05115981A (en) | 1993-05-14 |
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| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |