JPH06106360A - Resistance welding control or measuring instrument - Google Patents
Resistance welding control or measuring instrumentInfo
- Publication number
- JPH06106360A JPH06106360A JP28082392A JP28082392A JPH06106360A JP H06106360 A JPH06106360 A JP H06106360A JP 28082392 A JP28082392 A JP 28082392A JP 28082392 A JP28082392 A JP 28082392A JP H06106360 A JPH06106360 A JP H06106360A
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- Prior art keywords
- zero
- welding
- power factor
- current
- voltage
- Prior art date
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Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、交流式抵抗溶接機にお
いて被溶接物の有無を検出する機能を備えた抵抗溶接制
御又は測定装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resistance welding control or measuring device having a function of detecting the presence or absence of an object to be welded in an AC resistance welding machine.
【０００２】[0002]
【従来の技術】抵抗溶接は、複数の被溶接物（金属材）
を重ね合わせ、溶接電極でそれらの被溶接物に加圧をか
けながら電圧を印加して電流を流し、溶接部をジュール
熱によって加熱して溶融せしめ、それらの被溶接物を冶
金的に接合する技術である。このような抵抗溶接を実行
するために、一般の抵抗溶接機は、被溶接物を挟む一対
の溶接電極と、溶接電極を介して被溶接物を加圧する加
圧手段と、溶接電極を介して被溶接物に溶接電流を流す
溶接電源回路とを備えている。最近は、溶接ラインの省
力化や生産性の向上をはかるため、ロボットが可搬型の
抵抗溶接機を搭載して被溶接物の位置まで運んだり、所
定の溶接位置に被溶接物を搬入・搬出するフィーダ、ハ
ンドラ等が定置型抵抗溶接機の近くに設けられ、作業員
が付いていなくても自動的に溶接作業が行われるように
なっている。2. Description of the Related Art Resistance welding is used for a plurality of workpieces (metal materials).
Are overlapped with each other, and a voltage is applied to the objects to be welded with a welding electrode to apply an electric current, and the welded parts are heated by Joule heat to be melted and the objects to be welded are metallurgically bonded. It is a technology. In order to perform such resistance welding, a general resistance welding machine uses a pair of welding electrodes that sandwich the object to be welded, a pressing unit that pressurizes the object to be welded via the welding electrode, and a welding electrode. And a welding power supply circuit for supplying a welding current to the object to be welded. Recently, in order to save labor and improve productivity of the welding line, robots are equipped with a portable resistance welding machine to carry to the position of the work piece, or to carry in and carry out the work piece to a predetermined welding position. A feeder, a handler, etc. are installed near the stationary resistance welding machine so that welding work can be performed automatically even without an operator.
【０００３】[0003]
【発明が解決しようとする課題】ところが、自動式の溶
接ラインでは、何らかの原因で被溶接物が溶接位置にセ
ットされない場合に、抵抗溶接機の方は通常どおりに、
つまり被溶接物が在る場合と同様に動作し、結果的に溶
接不良の製品がラインを流れてしまうという問題があっ
た。However, in the automatic welding line, when the object to be welded is not set to the welding position for some reason, the resistance welding machine is normally operated.
In other words, there is a problem in that the product operates in the same manner as when there is an object to be welded, and as a result, a product with poor welding flows through the line.
【０００４】たとえば、図６および図７に示すようなナ
ット溶接において、金属片１００上の溶接位置つまりボ
ルト通し穴１００ａの位置にナット１０２が正しくセッ
トされれば、図７の(A) に示すように上部溶接電極１０
４がナット１０２の上に被さり、正常に抵抗溶接が行わ
れる。しかし、ナット・フィーダ（図示せず）の故障や
詰まり等によってナット１０２が溶接位置に供給されな
かったときは、図７の(B) に示すようにナット１０２が
無い状態で金属片１００だけが上部溶接電極１０４と下
部溶接電極１０６との間に挟まれて通電される。交流式
の抵抗溶接機で一般に用いられている定電流制御方式で
は、溶接電流を設定値に一致させるようにフィードバッ
クをかけるため、被溶接物の状態・有無に関係なく一定
の溶接電流が流れる。したがって、図７の(B) に示すよ
うに溶接電極１０４，１０６間にナット１０２が無い場
合でも、所定の溶接電流が流れるため、抵抗溶接が正常
に行われたものと判断されていた。その結果、金属片１
００にナット１０２が溶接されないまま、不良品がライ
ンを流れるという不具合が生じていた。このため、従来
は、そのような不良品を発見するための監視員をライン
に配置しなければならなかった。For example, in nut welding as shown in FIGS. 6 and 7, if the nut 102 is properly set at the welding position on the metal piece 100, that is, the position of the bolt through hole 100a, it is shown in FIG. 7 (A). As the upper welding electrode 10
4 is put on the nut 102, and resistance welding is normally performed. However, when the nut 102 is not supplied to the welding position due to a failure or clogging of the nut feeder (not shown), as shown in FIG. 7 (B), only the metal piece 100 is removed without the nut 102. It is sandwiched between the upper welding electrode 104 and the lower welding electrode 106 to be energized. In the constant current control method generally used in AC resistance welding machines, feedback is applied so that the welding current matches the set value, so that a constant welding current flows regardless of the state or presence of the work piece. Therefore, even if the nut 102 is not provided between the welding electrodes 104 and 106 as shown in FIG. 7B, a predetermined welding current flows, so that it was determined that the resistance welding was normally performed. As a result, metal piece 1
There was a problem that a defective product flows through the line without welding the nut 102 to 00. For this reason, conventionally, it has been necessary to arrange a watchman on the line to detect such defective products.
【０００５】本発明は、かかる問題点に鑑みてなされた
もので、特別なセンサやセンス線等を用いることなく溶
接電極間における被溶接物の有無を検出するようにした
抵抗溶接制御又は測定装置を提供することを目的とす
る。The present invention has been made in view of the above problems, and a resistance welding control or measuring device for detecting the presence or absence of an object to be welded between welding electrodes without using a special sensor or sense wire. The purpose is to provide.
【０００６】[0006]
【課題を解決するための手段】上記の目的を達成するた
めに、本発明の抵抗溶接制御又は測定装置は、交流式抵
抗溶接機の一次回路または二次回路に印加される交流電
圧の極性が変化する時点を検出するゼロ電圧検出手段
と、前記交流式抵抗溶接機の一次回路または二次回路を
流れる交流電流の各導通終了時点を検出するゼロ電流検
出手段と、前記ゼロ電圧検出手段からのゼロ電圧検出信
号と前記ゼロ電流検出手段からのゼロ電流検出信号とに
基づいて力率角を割り出す力率角検出手段と、前記力率
角検出手段より得られる力率角の値に基づいて溶接電極
間における被溶接物の有無を判定する判定手段とを具備
する構成とした。In order to achieve the above object, the resistance welding control or measuring apparatus of the present invention has a polarity of an AC voltage applied to a primary circuit or a secondary circuit of an AC resistance welding machine. Zero voltage detecting means for detecting a changing time point, zero current detecting means for detecting a conduction end time point of each of the alternating currents flowing through the primary circuit or the secondary circuit of the AC resistance welding machine, and the zero voltage detecting means Welding based on a power factor angle detecting means for calculating a power factor angle based on a zero voltage detecting signal and a zero current detecting signal from the zero current detecting means, and a value of the power factor angle obtained from the power factor angle detecting means. It is configured to include a determination means for determining the presence or absence of the object to be welded between the electrodes.
【０００７】[0007]
【作用】交流式抵抗溶接機において、電圧の極性が変化
する時点（電圧ゼロクロス点）とその直後の点弧時点と
の間の位相差は点弧角であり、各点弧時点からほぼ半サ
イクル経過後において電圧ゼロクロス点と電流の導通終
了時点との間の位相差は遅れ角である。点弧角と遅れ角
とが与えられると、所定の演算式から、力率角を求める
ことができる。[Operation] In the AC resistance welding machine, the phase difference between the time when the polarity of the voltage changes (voltage zero crossing point) and the time immediately after the ignition is the ignition angle. The phase difference between the voltage zero cross point and the end point of the current conduction after the lapse of time is the delay angle. Given the firing angle and the delay angle, the power factor angle can be obtained from a predetermined arithmetic expression.
【０００８】本発明では、各半サイクルまたは各１サイ
クル毎に、ゼロ電圧検出手段が電圧ゼロクロス点を検出
するとともに、ゼロ電流検出手段が電流の導通終了時点
を検出し、力率角検出手段がゼロ電圧検出手段からのゼ
ロ電圧検出信号とゼロ電流検出手段から点弧角、遅れ角
を割り出し、それら点弧角、遅れ角から力率角を割り出
す。According to the present invention, the zero voltage detecting means detects the voltage zero crossing point every half cycle or each one cycle, the zero current detecting means detects the current conduction end point, and the power factor angle detecting means detects The firing angle and the delay angle are calculated from the zero voltage detection signal from the zero voltage detection means and the zero current detection means, and the power factor angle is calculated from the firing angle and the delay angle.
【０００９】ところで、抵抗溶接機においては、通電中
に溶接電極間に被溶接物が無い場合には、それが在る場
合と比較して力率角の値が大きくなる。したがって、力
率角検出手段より得られる力率角の値が、抵抗溶接機の
固有値や被溶接物の材質・大きさ等に応じて予め設定さ
れたしきい値を超えたときは、判定手段は、被溶接物が
無い状態で通電が行われたものと判定する。By the way, in the resistance welding machine, when there is no object to be welded between the welding electrodes during energization, the value of the power factor angle becomes large as compared with the case where it exists. Therefore, when the value of the power factor angle obtained from the power factor angle detecting means exceeds a preset threshold value according to the eigenvalue of the resistance welding machine, the material and size of the workpiece, etc. Is determined to have been energized with no object to be welded.
【００１０】[0010]
【実施例】図１は、本発明の一実施例による抵抗溶接制
御装置を適用した単相交流式抵抗溶接機の回路構成を示
す。この抵抗溶接機において、入力端子１０，１２に入
力された商用周波数の交流電源電圧Ｅは、一対のサイリ
スタ１４，１６からなるコンタクタを介して溶接トラン
ス１８の一次コイルに供給される。溶接トランス１８の
二次コイルに発生した交流の誘導起電力（二次電圧）は
二次導体および一対の溶接電極２０，２２を介して被溶
接物２４，２６に印加され、二次回路に溶接電流ｉ2 が
流れる。FIG. 1 shows a circuit configuration of a single-phase AC resistance welding machine to which a resistance welding control device according to an embodiment of the present invention is applied. In this resistance welding machine, the AC power supply voltage E of the commercial frequency input to the input terminals 10 and 12 is supplied to the primary coil of the welding transformer 18 via a contactor composed of a pair of thyristors 14 and 16. The AC induced electromotive force (secondary voltage) generated in the secondary coil of the welding transformer 18 is applied to the objects to be welded 24, 26 via the secondary conductor and the pair of welding electrodes 20, 22, and welds to the secondary circuit. A current i2 flows.
【００１１】溶接電流ｉ2 の大きさ（実効値）は、通電
角によって決まるが、点弧角と通電角との間にほぼ一定
の関係があるので、点弧角によって決まるともいえる。
しかして、マイクロプロセッサ２８が点弧回路３０を介
してサイリスタ１４，１６の点弧タイミングを制御する
ことによって、溶接電流ｉ2 の実効値を制御する。ま
た、マイクロプロセッサ２８は、溶接電流ｉ2 を設定値
に一致させるように点弧タイミングを制御する。この定
電流制御を行うため、一次導体には、電流センサとし
て、たとえばカレント・トランス３２が設けられ、この
カレント・トランス３２の出力信号から溶接電流検出回
路３４が一次電流ｉ1 の実効値と溶接トランス１８の巻
数比とから溶接電流ｉ2 の実効値を測定し、その電流測
定値がマイクロプロセッサ２８に与えられる。Although the magnitude (effective value) of the welding current i2 is determined by the conduction angle, it can be said that it is determined by the firing angle because there is a substantially constant relationship between the firing angle and the conduction angle.
The microprocessor 28 controls the firing timing of the thyristors 14 and 16 via the firing circuit 30 to control the effective value of the welding current i2. Further, the microprocessor 28 controls the ignition timing so that the welding current i2 matches the set value. In order to perform this constant current control, a current transformer 32, for example, is provided on the primary conductor as a current sensor, and the welding current detection circuit 34 uses the output signal of the current transformer 32 to determine the effective value of the primary current i1 and the welding transformer. The effective value of the welding current i2 is measured from the turn ratio of 18 and the measured current value is supplied to the microprocessor 28.
【００１２】二次回路で溶接電流ｉ2 が流れている間、
一次回路ではｉ2 と同相の小さな電流（一次電流）ｉ1
が流れる。本実施例では、ゼロ電流検出回路３６が一次
回路に設けられる。このゼロ電流検出回路３６は、サイ
リスタ間の電圧を検知し、電流が流れると電圧が下が
り、電流が止まると電圧が上がることで、各半サイクル
毎に一次電流ｉ1 の導通終了時点を検出し、その導通終
了時点のタイミングを表すゼロ電流検出信号をマイクロ
プロセッサ２８に与える。While the welding current i2 is flowing in the secondary circuit,
In the primary circuit, a small current (primary current) i1 in phase with i2
Flows. In this embodiment, the zero current detection circuit 36 is provided in the primary circuit. The zero current detection circuit 36 detects the voltage between the thyristors, and when the current flows, the voltage decreases, and when the current stops, the voltage increases, thereby detecting the conduction end point of the primary current i1 every half cycle, A zero current detection signal representing the timing at the end of the conduction is given to the microprocessor 28.
【００１３】また、ゼロ電圧検出回路３８も一次回路に
設けられる。このゼロ電圧検出回路３８は、各半サイク
ル毎に電源電圧Ｅの極性が変わる時点（ゼロクロス点）
を検出し、そのゼロクロス点のタイミングを表すゼロ電
圧検出信号をマイクロプロセッサ２８に与える。A zero voltage detection circuit 38 is also provided in the primary circuit. This zero voltage detection circuit 38 is a point (zero cross point) at which the polarity of the power supply voltage E changes every half cycle.
Is detected and a zero voltage detection signal indicating the timing of the zero cross point is given to the microprocessor 28.
【００１４】マイクロプロセッサ２８は、ゼロ電圧検出
回路３８からのゼロ電圧検出信号とゼロ電流検出回路３
６からのゼロ電流検出信号とから力率角を算出する。図
２〜図４を参照して、以下に本実施例による力率角の算
出方法を説明する。The microprocessor 28 includes a zero voltage detection signal from the zero voltage detection circuit 38 and a zero current detection circuit 3.
The power factor angle is calculated from the zero current detection signal from 6. A method of calculating the power factor angle according to the present embodiment will be described below with reference to FIGS.
【００１５】図２は、交流式抵抗溶接機の等価回路を示
す。この回路において、インダクタンスＬは主として溶
接トランス（１８）の漏れリアクタンスであり、抵抗Ｒ
は一次および二次導体の抵抗、および被溶接物（２４，
２６）の抵抗等を含む合成抵抗である。スイッチＳＷは
サイリスタ・コンタクタ（１４，１６）に対応し、交流
電源電圧ｅは入力電圧Ｅに対応する。FIG. 2 shows an equivalent circuit of the AC resistance welding machine. In this circuit, the inductance L is mainly the leakage reactance of the welding transformer (18) and the resistance R
Is the resistance of the primary and secondary conductors, and the work piece (24,
26) is a combined resistance including the resistance and the like. The switch SW corresponds to the thyristor contactor (14, 16), and the AC power supply voltage e corresponds to the input voltage E.
【００１６】かかるＬＲ回路において、ある時刻［０］
にスイッチＳＷを閉成すると、図３に示すような波形の
電流ｉが流れる。図３において、ｉs は定常電流、ｉt
は過渡電流で、これらの電流ｉs 、ｉt を合成したもの
が、実際に流れる電流ｉである。また、時刻［０］と直
前の電圧ゼロクロス点ＴZ 間の位相角φは初期点弧角で
あり、定常電流ｉs が時刻［０］前に流れた場合の直前
の仮想電流ゼロクロス点ＴP と電圧ゼロクロス点ＴZ 間
の位相角ψは力率角である。そうすると、電流ｉは次式
のように表される。 ｉ＝ｉs ＋ｉt ＝ｓｉｎ（ωｔ＋φ−ψ）−ｓｉｎ（φ−ψ）・ｅｘｐ（−Ｒ／Ｌ）ｔ …… (1) ω、（−Ｒ／Ｌ）は定数で、φはマイクロプロセッサ２
８の制御下にあるから各半サイクルまたは各１サイクル
の期間中に電流ｉの瞬時値が零になった時間ｔを検出し
て、その時間ｔを上式(1) に代入することにより、各半
サイクルまたは各１サイクルにおける力率角ψを求める
ことができる。In such an LR circuit, at a certain time [0]
When the switch SW is closed, a current i having a waveform as shown in FIG. 3 flows. In FIG. 3, is is a steady current and it is
Is a transient current, and the sum of these currents is and it is the actually flowing current i. Further, the phase angle φ between the time [0] and the voltage zero cross point TZ immediately before is the initial firing angle, and the virtual current zero cross point TP and the voltage zero cross immediately before the steady current is flows before the time [0]. The phase angle ψ between the points TZ is the power factor angle. Then, the current i is expressed by the following equation. i = is + it = sin (ωt + φ−φ) −sin (φ−φ) · exp (−R / L) t (1) ω and (−R / L) are constants, and φ is the microprocessor 2
Since it is under the control of 8, the time t at which the instantaneous value of the current i becomes zero during each half cycle or each one cycle is detected, and the time t is substituted into the above equation (1), The power factor angle ψ in each half cycle or each one cycle can be obtained.
【００１７】本実施例では、図４に示すような電圧・電
流波形から各半サイクルまたは各１サイクルにおける力
率角ψi,ψi+1,…を求める。図４において、φi,φi+1,
…は各１サイクルにおける点弧角で、δi,δi+1,…は各
１サイクルにおける遅れ角である。各点弧角φi,φi+1,
…は、電圧ｅの極性が変わる各電圧ゼロクロス点からサ
イリスタ１２，１４が点弧されるまでの時間である。し
たがって、ゼロ電圧検出回路３８が電圧ゼロクロス点を
検出した時刻を知ることで、マイクロプロセッサ２８は
各点弧角φi,φi+1,…の値を管理・把握することができ
る。 また、各遅れ角δi,δi+1 …と電流ｉとの間に
は、位相角が（π＋δi),(π＋δi+1)、…の時に各半サ
イクルにおける電流ｉの導通時間が終了するという関係
がある。そして、各遅れ角δi,δi+1 …は、点弧タイミ
ングから半サイクル後における電圧ゼロクロス点とその
直後に電流ｉの瞬時値が零になる時点との間の時間とし
て測定できる。In this embodiment, the power factor angles ψi, ψi + 1, ... In each half cycle or each one cycle are obtained from the voltage / current waveforms shown in FIG. In FIG. 4, φi, φi + 1,
... are firing angles in each one cycle, and δi, δi + 1, ... are delay angles in each one cycle. Each firing angle φi, φi + 1,
Is the time from when each voltage zero crossing point where the polarity of the voltage e changes to when the thyristors 12 and 14 are fired. Therefore, by knowing the time when the zero voltage detection circuit 38 detects the voltage zero cross point, the microprocessor 28 can manage and grasp the values of the respective firing angles φi, φi + 1, .... Further, between each delay angle δi, δi + 1 ... And the current i, the conduction time of the current i in each half cycle ends when the phase angle is (π + δi), (π + δi + 1) ,. There is. The respective delay angles δi, δi + 1, ... Can be measured as the time between the voltage zero cross point after a half cycle from the ignition timing and the time immediately after that when the instantaneous value of the current i becomes zero.
【００１８】したがって、本実施例では、ゼロ電圧検出
回路３８からのゼロ電圧検出信号とゼロ電流検出回路３
６からのゼロ電流検出信号とに基づいて、各半サイクル
または各１サイクルにおける点弧角φi,φi+1,…および
遅れ角δi,δi+1 …を検出して、それらのパラメータか
ら上式(1) により各半サイクルにおける力率角ψi,ψi+
1,…を求める。Therefore, in this embodiment, the zero voltage detection signal from the zero voltage detection circuit 38 and the zero current detection circuit 3 are used.
Based on the zero current detection signal from 6, the ignition angles φi, φi + 1, ... And the delay angles δi, δi + 1, ... In each half cycle or each one cycle are detected, and the above equation is calculated from those parameters. (1) gives the power factor angles ψi, ψi + in each half cycle.
Ask for 1,…
【００１９】もっとも、上式(1) を演算して力率角ψi,
ψi+1,…を算出するには、相当な演算ビット数と演算時
間を要するので、マイクロプロセッサ２８の負担が大き
くなる。そこで、別個の計算機により、種々の点弧角φ
および遅れ角δの値に対する力率角の値を予め演算し
て、図５に示すようなルック・アップ・テーブルをメモ
リ４０に格納し、各半サイクルにおいて検出された点弧
角φi および遅れ角δiを引数として、それらに対応す
る力率角ψijをメモリ４０から引き出す（読み出す）よ
うにすれば、マイクロプロセッサ２８が複雑な演算処理
を行わなくとも、各半サイクル毎に力率角ψを即座に割
り出すことができる。However, the above equation (1) is calculated to calculate the power factor angle ψi,
Calculation of ψi + 1, ... Requires a considerable number of calculation bits and calculation time, and thus the burden on the microprocessor 28 increases. Therefore, using a separate computer, various firing angles φ
And the value of the power factor angle with respect to the value of the delay angle δ are calculated in advance and a look-up table as shown in FIG. 5 is stored in the memory 40, and the firing angle φi and the delay angle detected in each half cycle are stored. If the power factor angles ψij corresponding to these are taken out (read out) from the memory 40 using δi as an argument, the power factor angles ψ can be immediately calculated every half cycle without the microprocessor 28 performing complicated arithmetic processing. Can be calculated to
【００２０】ところで、抵抗溶接機における力率角は変
圧器や二次導体等の構造に応じて各抵抗溶接機特有の値
をとるが、溶接電極間に被溶接物が在るか無いかに応じ
て、各抵抗溶接機のＬＲ回路における合成抵抗Ｒの値が
変化し、ひいては力率角の値が変化する。一例として、
０．８ｍｍ厚のＳＰＣ（冷間圧延鋼鈑）を２枚重ねて溶
接する普通の抵抗溶接機において、溶接電極がこれらの
ＳＰＣを挟んだ状態で通電が行われると力率角は４７゜
であるのに対し、溶接電極がこれらのＳＰＣを挟まない
状態で通電が行われると力率角は５９゜まで上昇するこ
とが確認されている。一般に、溶接電極間に被溶接物が
無い場合は、それが在る場合と比較して力率角の値が約
５〜１５゜上昇する。By the way, the power factor angle in the resistance welding machine takes a value peculiar to each resistance welding machine according to the structure of the transformer, the secondary conductor, etc., but it depends on whether or not there is an object to be welded between the welding electrodes. As a result, the value of the combined resistance R in the LR circuit of each resistance welder changes, which in turn changes the value of the power factor angle. As an example,
In an ordinary resistance welding machine that welds two 0.8 mm thick SPCs (cold rolled steel sheets) in layers, when the welding electrode is energized while sandwiching these SPCs, the power factor angle is 47 °. On the other hand, it has been confirmed that the power factor angle rises to 59 ° when the welding electrode is energized without sandwiching these SPCs. Generally, when there is no object to be welded between the welding electrodes, the value of the power factor angle increases by about 5 to 15 ° as compared with the case where it exists.
【００２１】しかして、マイクロプロセッサ２８は、通
電時間中に半サイクルまたは各１サイクル毎に力率角ψ
を検出して、力率角ψの平均値を求め、その平均値を所
定のしきい値または基準値と比較し、比較結果から、通
電中に溶接電極２０，２２間に被溶接物２４，２６のい
ずれか一方または双方が存在していたか否かを判定す
る。しきい値は、当該抵抗溶接機の固有値や被溶接物２
４，２６の材質・サイズ等に応じて適当な値に設定され
る。Therefore, the microprocessor 28 is arranged so that the power factor angle ψ is calculated every half cycle or each cycle during the energization time.
Is detected, the average value of the power factor angle ψ is obtained, the average value is compared with a predetermined threshold value or a reference value, and from the comparison result, the object to be welded 24, It is determined whether or not one or both of the 26 are present. The threshold value is the characteristic value of the resistance welding machine or the object to be welded 2
It is set to an appropriate value according to the material and size of 4, 26.
【００２２】マイクロプロセッサ２８は、力率角ψの平
均値がしきい値を越えたときは被溶接物無しと判定し、
表示器４２等を通じて警報を出すとともに、溶接ライン
上の関連装置に異常を知らせる。これにより、当該抵抗
溶接は不良とされ、自動的に各部の点検や不良品除去等
の処置がとられることとなる。したがって、不良品をチ
ェックのための監視員は要らなくなる。The microprocessor 28 judges that there is no object to be welded when the average value of the power factor angle ψ exceeds the threshold value,
An alarm is issued through the display 42 or the like, and the related devices on the welding line are notified of the abnormality. As a result, the resistance welding becomes defective, and measures such as inspection of each part and removal of defective products are automatically taken. Therefore, a supervisor for checking defective products is unnecessary.
【００２３】上述した実施例では、ゼロ電圧検出回路３
８およびゼロ電流検出回路３６をそれぞれ一次回路に設
け、一次側の電圧、電流を監視して力率角ψを求め、力
率角ψの値に基づいて溶接電極２０，２２間における被
溶接物２４，２６の有無を検出するようにしており、溶
接電極２０，２２に電圧センス線を接続する必要はな
い。溶接電極２０，２２に電圧センス線を接続し、溶接
電極２０，２２間の電圧に基づいて被溶接物２４，２６
の有無を検出することも可能ではあるが、この方式にお
いては、ロボット（図示せず）や加圧機構４４の駆動に
よって二次導体や溶接電極２０，２２が運動・移動する
際に、電圧センス線が断線するおそれがあり、安心して
自動化・省力化を推進できないという欠点がある。本実
施例においては、溶接電極２０，２２に電圧センス線を
接続する必要がないので、そのような断線事故等の問題
はなく、安心して自動化・省力化を推進できる。In the embodiment described above, the zero voltage detection circuit 3
8 and the zero current detection circuit 36 are respectively provided in the primary circuit, the voltage and the current on the primary side are monitored to obtain the power factor angle ψ, and the workpiece to be welded between the welding electrodes 20 and 22 is based on the value of the power factor angle ψ. The presence or absence of 24 and 26 is detected, and it is not necessary to connect a voltage sense line to the welding electrodes 20 and 22. A voltage sense line is connected to the welding electrodes 20 and 22, and objects to be welded 24 and 26 are welded based on the voltage between the welding electrodes 20 and 22.
Although it is possible to detect the presence or absence of the voltage, in this method, when the secondary conductor and the welding electrodes 20 and 22 move / move by the drive of a robot (not shown) and the pressurizing mechanism 44, voltage sensing is performed. There is a risk that the wire may be broken, and automation and labor saving cannot be promoted with peace of mind. In the present embodiment, since it is not necessary to connect the voltage sense lines to the welding electrodes 20 and 22, there is no problem such as a disconnection accident, and automation and labor saving can be promoted with peace of mind.
【００２４】なお、上述した実施例は抵抗溶接制御装置
に係るものであったが、本発明は抵抗溶接測定装置にも
適用可能である。Although the above-described embodiment relates to the resistance welding control device, the present invention is also applicable to the resistance welding measuring device.
【００２５】[0025]
【発明の効果】以上説明したように、本発明の抵抗溶接
制御又は測定装置によれば、交流式の抵抗溶接機におい
て、電圧ゼロクロス点と電流導通終了時点とから力率角
を算出し、力率角の値に基づいて溶接電極間における被
溶接物の有無を判定するようにしたので、通電状況ない
し溶接良否の自動監視が可能である。また、ゼロ電圧検
出手段およびゼロ電流検出手段を一次回路に設けること
で、センス線等の断線事故の問題を解消することができ
る。したがって、安心して溶接ラインの自動化・省力化
を推進することができる。As described above, according to the resistance welding control or measuring apparatus of the present invention, in the AC resistance welding machine, the power factor angle is calculated from the voltage zero cross point and the current conduction end point, and the force Since the presence / absence of the object to be welded between the welding electrodes is determined based on the value of the rate angle, it is possible to automatically monitor the energization state or the welding quality. Further, by providing the zero voltage detecting means and the zero current detecting means in the primary circuit, it is possible to solve the problem of the disconnection accident of the sense line or the like. Therefore, automation and labor saving of the welding line can be promoted with peace of mind.
【図１】本発明の一実施例による抵抗溶接制御装置を適
用した単相交流式抵抗溶接機の回路構成を示す回路図で
ある。FIG. 1 is a circuit diagram showing a circuit configuration of a single-phase AC resistance welding machine to which a resistance welding control device according to an embodiment of the present invention is applied.
【図２】交流式抵抗溶接機の等価回路を示す回路図であ
る。FIG. 2 is a circuit diagram showing an equivalent circuit of an AC resistance welding machine.
【図３】図２の等価回路における電圧および電流の波形
を示す図である。FIG. 3 is a diagram showing voltage and current waveforms in the equivalent circuit of FIG.
【図４】実施例による簡易な力率角算出方法を説明する
ための電圧および電流の波形を示す図である。FIG. 4 is a diagram showing voltage and current waveforms for explaining a simple power factor angle calculation method according to an embodiment.
【図５】各サイクル毎に検出された点弧角φおよび遅れ
角δから力率角ψを瞬時に引き出すためのルック・アッ
プ・テーブルを概念的に示す図である。FIG. 5 is a diagram conceptually showing a look-up table for instantaneously extracting a power factor angle ψ from a firing angle φ and a delay angle δ detected in each cycle.
【図６】ナット溶接を説明するための斜視図である。FIG. 6 is a perspective view for explaining nut welding.
【図７】ナット溶接において溶接電極間にナットが在る
場合と無い場合のそれぞれの通電状況を示す略側面図で
ある。FIG. 7 is a schematic side view showing respective energization states when a nut is present between welding electrodes and when a nut is not present in nut welding.
１８ 溶接トランス ２０，２２ 溶接電極 ２４，２６ 被溶接物 ２８ マイクロプロセッサ ３０ 点弧回路 ３６ ゼロ電流検出回路 ３８ ゼロ電圧検出回路 ４０ メモリ ４２ 表示器 18 Welding transformer 20,22 Welding electrode 24,26 Welding object 28 Microprocessor 30 Starting circuit 36 Zero current detection circuit 38 Zero voltage detection circuit 40 Memory 42 Display
Claims (1)
回路に印加される交流電圧の極性が変化する時点を検出
するゼロ電圧検出手段と、 前記交流式抵抗溶接機の一次回路または二次回路を流れ
る交流電流の各導通終了時点を検出するゼロ電流検出手
段と、 前記ゼロ電圧検出手段からのゼロ電圧検出信号と前記ゼ
ロ電流検出手段からのゼロ電流検出信号とに基づいて力
率角を割り出す力率角検出手段と、 前記力率角検出手段より得られる力率角の値に基づいて
溶接電極間における被溶接物の有無を判定する判定手段
と、を具備することを特徴とする抵抗溶接制御又は測定
装置。1. A zero voltage detecting means for detecting a time when a polarity of an AC voltage applied to a primary circuit or a secondary circuit of an AC resistance welding machine is changed, and a primary circuit or a secondary circuit of the AC resistance welding machine. Zero current detection means for detecting the end point of each conduction of the alternating current flowing through the circuit, the power factor angle based on the zero voltage detection signal from the zero voltage detection means and the zero current detection signal from the zero current detection means. A resistance comprising: a power factor angle detecting means for indexing; and a determining means for determining the presence or absence of an object to be welded between welding electrodes based on a value of the power factor angle obtained from the power factor angle detecting means. Welding control or measuring device.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4280823A JP2784618B2 (en) | 1992-09-25 | 1992-09-25 | Resistance welding control device and resistance welding measuring device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4280823A JP2784618B2 (en) | 1992-09-25 | 1992-09-25 | Resistance welding control device and resistance welding measuring device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH06106360A true JPH06106360A (en) | 1994-04-19 |
| JP2784618B2 JP2784618B2 (en) | 1998-08-06 |
Family
ID=17630483
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4280823A Expired - Lifetime JP2784618B2 (en) | 1992-09-25 | 1992-09-25 | Resistance welding control device and resistance welding measuring device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2784618B2 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5632912A (en) * | 1995-06-16 | 1997-05-27 | Cecil; Dimitrios G. | Resistance projection welding system and method for welding a projection weld nut to a workpiece |
| US6278077B1 (en) | 1999-12-02 | 2001-08-21 | Dimitrios G. Cecil | Weld indexing method and system |
| CN117879179A (en) * | 2024-03-11 | 2024-04-12 | 西安热工研究院有限公司 | Electrical equipment abnormal power state monitoring method and system |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS58500315A (en) * | 1979-01-29 | 1983-03-03 | スクウエア− デイ− コンパニ− | Power factor monitoring and control device for resistance welding |
-
1992
- 1992-09-25 JP JP4280823A patent/JP2784618B2/en not_active Expired - Lifetime
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS58500315A (en) * | 1979-01-29 | 1983-03-03 | スクウエア− デイ− コンパニ− | Power factor monitoring and control device for resistance welding |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5632912A (en) * | 1995-06-16 | 1997-05-27 | Cecil; Dimitrios G. | Resistance projection welding system and method for welding a projection weld nut to a workpiece |
| US5808266A (en) * | 1995-06-16 | 1998-09-15 | Cecil; Dimitrios G. | Resistance projection welding system and method for welding a fastener element to a workpiece |
| USRE37607E1 (en) * | 1995-06-16 | 2002-03-26 | Dimitrios G. Cecil | Resistance projection welding system and method for welding a fastener element to a workpiece |
| US6278077B1 (en) | 1999-12-02 | 2001-08-21 | Dimitrios G. Cecil | Weld indexing method and system |
| CN117879179A (en) * | 2024-03-11 | 2024-04-12 | 西安热工研究院有限公司 | Electrical equipment abnormal power state monitoring method and system |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2784618B2 (en) | 1998-08-06 |
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