JP2523513B2 - Voltage detector for welding current and power supply for welding - Google Patents
Voltage detector for welding current and power supply for weldingInfo
- Publication number
- JP2523513B2 JP2523513B2 JP61161364A JP16136486A JP2523513B2 JP 2523513 B2 JP2523513 B2 JP 2523513B2 JP 61161364 A JP61161364 A JP 61161364A JP 16136486 A JP16136486 A JP 16136486A JP 2523513 B2 JP2523513 B2 JP 2523513B2
- Authority
- JP
- Japan
- Prior art keywords
- circuit
- output
- welding
- voltage
- welding current
- 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
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- Arc Welding Control (AREA)
- Control Of Electrical Variables (AREA)
Description
【発明の詳細な説明】 産業上の利用分野 本発明は抵抗溶接機等における溶接電流対応電圧検出
装置および溶接用電源装置に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a welding current corresponding voltage detection device and a welding power supply device in a resistance welding machine or the like.
従来の技術 従来、抵抗溶接機においては、短時間に大電流が流れ
るため電源電圧の変動が大きくなり、溶接電流が変化
し、溶接品質が低下してしまうという問題点があった。
この問題点に鑑み、電流を安定にするため、従来より定
電流制御方法と、電圧補償制御方法が提案されていた。
電圧補償制御方法としては、電圧波形そのものを利用し
て三角関数と一次関数との交点による位相制御や、力率
による位相角対出力実効値の曲線と設定電圧との差によ
る位相制御などが行われていた。2. Description of the Related Art Conventionally, in a resistance welding machine, since a large current flows in a short time, the power supply voltage fluctuates greatly, the welding current changes, and the welding quality deteriorates.
In view of this problem, a constant current control method and a voltage compensation control method have been conventionally proposed in order to stabilize the current.
Voltage compensation control methods include phase control using the intersection of trigonometric functions and linear functions using the voltage waveform itself, and phase control using the difference between the curve of the output effective value and the phase angle due to the power factor and the set voltage. It was being appreciated.
発明が解決しようとする問題点 しかし、上記従来の制御方法では、抵抗溶接機特有の
力率変化に対し、溶接トランス一次側の位相制御電圧に
対する二次側の出力電流実効値との関係への定性的な理
論が明確ではなく、実験的手法であったため、補償精度
が悪いという問題点があった。DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, in the above-mentioned conventional control method, in relation to the power factor change peculiar to the resistance welding machine, the relationship between the secondary output current effective value and the phase control voltage of the welding transformer primary side Since the qualitative theory was not clear and it was an experimental method, there was a problem that the compensation accuracy was poor.
問題点を解決するための手段 上記問題点を解決するため、本発明の溶接電流対応電
圧検出装置は、交流電源に位相制御素子を介して一次巻
線が接続された溶接トランスと、前記交流電源の電源電
圧が入力され溶接用電源装置における力率による位相遅
れに比例した電圧関数を作り出す第1CR回路と、前記位
相制御素子の導通を検出する導通検出回路と、前記導通
検出回路の出力によりオフするスイッチと、前記第1CR
回路の出力が前記スイッチを介して入力され前記力率に
よる無効分を作り出す第2CR回路と、前記第1CR回路の出
力と前記第2CR回路の出力がそれぞれ入力されて前記溶
接トランスの二次巻線に流れる溶接電流に対応した電圧
を出力する差動増幅器を備えたものである。Means for Solving the Problems In order to solve the above problems, a welding current corresponding voltage detection device of the present invention is a welding transformer in which a primary winding is connected to an AC power supply via a phase control element, and the AC power supply. The first CR circuit that receives the power supply voltage of 1 to generate a voltage function proportional to the phase delay due to the power factor in the welding power supply device, the conduction detection circuit that detects conduction of the phase control element, and the output of the conduction detection circuit that turns off Switch and the first CR
A secondary winding of the welding transformer in which the output of the circuit is input through the switch and a second CR circuit that creates a reactive component due to the power factor is input, and the output of the first CR circuit and the output of the second CR circuit are input respectively. It is equipped with a differential amplifier that outputs a voltage corresponding to the welding current flowing through.
また、本発明の溶接用電源装置は、交流電源に位相制
御素子を介して一次巻線が接続された溶接トランスと、
前記交流電源の電源電圧が入力され溶接用電源装置にお
ける力率による位相遅れに比例した電圧関数を作り出す
第1CR回路と、前記位相制御素子の導通を検出する導通
検出回路と、前記導通検出回路の出力によりオフするス
イッチと、前記第1CR回路の出力が前記スイッチを介し
て入力され前記力率による無効分を作り出す第2CR回路
と、前記第1CR回路の出力と前記第2CR回路の出力がそれ
ぞれ入力されて前記溶接トランスの二次巻線に流れる溶
接電流に対応した電圧を出力する差動増幅器と、前記差
動増幅器の出力電圧からその実効値を得る実効値変換回
路と、溶接電流値を設定する溶接電流設定回路と、前記
実効値変換回路の出力と前記溶接電流設定回路の出力が
入力される比較増幅器と、前記比較増幅器の出力に基づ
き前記位相制御素子の導通位相を制御する位相制御回路
を備えてなるものである。The welding power supply device of the present invention is a welding transformer in which a primary winding is connected to an AC power supply via a phase control element,
A power source voltage of the AC power source is input, a first CR circuit that creates a voltage function proportional to a phase delay due to a power factor in a welding power source, a conduction detection circuit that detects conduction of the phase control element, and a conduction detection circuit. A switch that is turned off by an output, a second CR circuit in which the output of the first CR circuit is input through the switch to generate an invalid component due to the power factor, and an output of the first CR circuit and an output of the second CR circuit are input, respectively. A differential amplifier that outputs a voltage corresponding to the welding current flowing in the secondary winding of the welding transformer, an effective value conversion circuit that obtains an effective value from the output voltage of the differential amplifier, and a welding current value is set A welding current setting circuit, a comparison amplifier to which the output of the effective value conversion circuit and the output of the welding current setting circuit are input, and conduction of the phase control element based on the output of the comparison amplifier. It is made of a phase control circuit for controlling the phase.
作用 上記構成において電源電圧から、溶接機の力率に対応
して溶接トランスの一次巻線に印加された位相制御電圧
に対する二次側の溶接電流を等価的に求められる。さら
には、溶接電流を一定にする制御を行う。Operation In the above configuration, the welding current on the secondary side can be equivalently obtained from the power supply voltage in accordance with the power factor of the welding machine and the phase control voltage applied to the primary winding of the welding transformer. Further, the welding current is controlled to be constant.
実 施 例 以下、本発明の実施例について添付図面を参照して説
明する。Embodiment An embodiment of the present invention will be described below with reference to the accompanying drawings.
第１図において、１は溶接トランスであり、その一次
巻線1aには逆並列接続されたサイリスタ（位相制御素
子）2a,2bを介して交流電源に接続されている。In FIG. 1, reference numeral 1 is a welding transformer, which is connected to an AC power supply through its primary winding 1a through thyristors (phase control elements) 2a and 2b connected in antiparallel.
３は交流電源の電源電圧Vinが入力されるトランスで
あり、このトランス３の出力は可変抵抗４とコンデンサ
５よりなる第1CR回路６に入力される。この第1CR回路６
の出力はバッファ回路7,8を介して差動増幅器９の一方
の入力端子に入力される。また、第1CR回路６の出力は
上記バッファ回路7,8およびスイッチ10を介して、コン
デンサ11と可変抵抗12よりなる第2CR回路13に入力され
る。この第2CR回路13の出力はバッファ回路14を介して
差動増幅器９の他方の入力端子に入力される。15は差動
増幅器９の出力値を実効値に変換する実効値変換回路、
16は溶接トランス１の二次巻線に流れる溶接電流i2を設
定する溶接電流設定回路、17は実効値変換回路15の出力
値と溶接電流設定回路16の出力値とを比較する比較増幅
器である。この比較増幅器17の出力はフィードバック回
路18を介して位相制御回路19に入力される。この位相制
御回路19は入力信号に基づき、サイリスタ2a,2bの導通
位相角を制御する。20はトランスであり、サイリスタ2
a,2bの端子間電圧が入力され、その出力信号は整流回路
21を介して比較増幅器（導通検出回路）22に入力され
る。そして、比較増幅器22は、サイリスタ2a,2bの導通
状態におけるサイリスタ2a,2b間の端子電圧が入力され
ると、そのときの出力信号によってスイッチ10をオフす
る。Reference numeral 3 is a transformer to which the power supply voltage Vin of the AC power supply is input, and the output of this transformer 3 is input to the first CR circuit 6 including the variable resistor 4 and the capacitor 5. This first CR circuit 6
Is output to one input terminal of the differential amplifier 9 via the buffer circuits 7 and 8. Further, the output of the first CR circuit 6 is input to the second CR circuit 13 including the capacitor 11 and the variable resistor 12 via the buffer circuits 7 and 8 and the switch 10. The output of the second CR circuit 13 is input to the other input terminal of the differential amplifier 9 via the buffer circuit 14. 15 is an effective value conversion circuit for converting the output value of the differential amplifier 9 into an effective value,
16 is a welding current setting circuit that sets the welding current i 2 flowing in the secondary winding of the welding transformer 1, and 17 is a comparison amplifier that compares the output value of the effective value conversion circuit 15 with the output value of the welding current setting circuit 16. is there. The output of the comparison amplifier 17 is input to the phase control circuit 19 via the feedback circuit 18. The phase control circuit 19 controls the conduction phase angle of the thyristors 2a and 2b based on the input signal. 20 is a transformer, thyristor 2
The voltage between terminals a and 2b is input, and the output signal is a rectifier circuit.
It is input to the comparison amplifier (conduction detection circuit) 22 via 21. Then, when the terminal voltage between the thyristors 2a and 2b in the conductive state of the thyristors 2a and 2b is input, the comparison amplifier 22 turns off the switch 10 by the output signal at that time.
抵抗溶接機は力率が悪いため、第２図および第３図に
示すように位相制御電圧V1と溶接電流i2とは位相がずれ
ている。また、電源電圧Vinが実線の状態から点線で示
したように変化すると溶接電流i2も同様に変化する。Since the resistance welding machine has a poor power factor, the phase control voltage V 1 and the welding current i 2 are out of phase as shown in FIGS. 2 and 3. Further, when the power supply voltage Vin changes from the state of the solid line as shown by the dotted line, the welding current i 2 also changes.
一般的に位相制御された電圧は、溶接機の力率 とする（ただし、Ｒは抵抗分,Lはリアクタンス分）と、 となり（ただしθは制御角）、溶接電流ｉは ｉ＝/|E|で示されるため、第４図に示す斜線部分が溶
接電流ｉに対応した電圧となる。Generally, the phase-controlled voltage is the power factor of the welding machine. (Where R is resistance and L is reactance) (Where θ is a control angle), and the welding current i is represented by i = / | E |, the shaded portion in FIG. 4 is the voltage corresponding to the welding current i.
すなわち、電源電圧Vinがトランス３を介して第1CR回
路６に入力されると、第1CR回路６の出力として|E|sin
（wt＋θ−）が求められる。この第1CR回路６の出力
はバッファ回路7,8により全波整流される。このバッフ
ァ回路８の出力信号f1（ｔ）を第４図に示す。That is, when the power supply voltage Vin is input to the first CR circuit 6 via the transformer 3, the output of the first CR circuit 6 is | E | sin.
(Wt + θ−) is required. The output of the first CR circuit 6 is full-wave rectified by the buffer circuits 7 and 8. The output signal f 1 (t) of this buffer circuit 8 is shown in FIG.
一方、サイリスタ2a,2bの端子間電圧はトランス20に
より検出され整流回路21を介して比較増幅器22に入力さ
れ、サイリスタ2a,2bのオン状態を比較増幅器22により
検出し、このときの比較増幅器22の出力信号によりスイ
ッチ10をオフする。On the other hand, the voltage between the terminals of the thyristors 2a, 2b is detected by the transformer 20 and input to the comparison amplifier 22 via the rectifier circuit 21, and the comparison amplifier 22 detects the ON state of the thyristors 2a, 2b. The switch 10 is turned off by the output signal of.
第2CR回路13のコンデンサ11はスイッチ10がオンであ
るときバッファ回路８の出力信号により充電され、スイ
ッチ10がオフすると、コンデンサ11の充電電荷は可変抵
抗12を介して放電され、第2CR回路13の出力信号とし
て、 が得られる。The capacitor 11 of the second CR circuit 13 is charged by the output signal of the buffer circuit 8 when the switch 10 is on, and when the switch 10 is off, the charged charge of the capacitor 11 is discharged through the variable resistor 12 and the second CR circuit 13 Output signal of Is obtained.
なお、 となるように選定しておく。第2CR回路13の出力信号は
バッファ回路14に入力され、このバッファ回路14は第４
図に示す出力信号f2（ｔ）を出力する。In addition, It is selected so that The output signal of the second CR circuit 13 is input to the buffer circuit 14, and the buffer circuit 14 outputs the fourth signal.
The output signal f 2 (t) shown in the figure is output.
差動増幅器９にはバッファ回路８の出力信号f1（ｔ）
とバッファ回路14の出力信号f2（ｔ）が入力され、その
出力信号として第４図に斜線で示すような溶接電流i2に
比例した電圧関数が得られる（なお、第４図の出力信号
f1（ｔ）で示される領域の内、前記斜線の領域を除いた
部分を特に無効分と呼ぶ）。The output signal f 1 (t) of the buffer circuit 8 is applied to the differential amplifier 9.
And the output signal f 2 (t) of the buffer circuit 14 is input, and as the output signal, a voltage function proportional to the welding current i 2 as shown by the slanted line in FIG. 4 is obtained (note that the output signal of FIG.
Of the area indicated by f 1 (t), the portion excluding the hatched area is particularly called an invalid portion).
さらに、この差動増幅器９の出力信号は実効値変換回
路15により実効値に変換され、比較増幅器17に入力され
る。比較増幅器17は実効値変換回路15の出力信号と溶接
電流設定回路16の出力信号を比較する。この比較増幅器
17の出力信号はフィードバック回路18を介して位相制御
回路19に入力され、位相制御回路19は比較増幅器17の出
力信号に基づき、サイリスタ2a,2bの導通位相角を制御
する。この結果、電源電圧Vinが変動しても溶接電流は
一定となる。Further, the output signal of the differential amplifier 9 is converted into an effective value by the effective value conversion circuit 15 and input to the comparison amplifier 17. The comparison amplifier 17 compares the output signal of the effective value conversion circuit 15 with the output signal of the welding current setting circuit 16. This comparison amplifier
The output signal of 17 is input to the phase control circuit 19 via the feedback circuit 18, and the phase control circuit 19 controls the conduction phase angles of the thyristors 2a and 2b based on the output signal of the comparison amplifier 17. As a result, the welding current becomes constant even if the power supply voltage Vin changes.
発明の効果 以上のように本発明によれば、溶接電流に対応した電
圧を正確に得ることができるとともに、この電圧に基づ
き、位相制御素子を導通位相角を制御するので、溶接電
流が一定となり、溶接品質を安定化することができる。As described above, according to the present invention, the voltage corresponding to the welding current can be accurately obtained, and the conduction phase angle of the phase control element is controlled based on this voltage, so that the welding current becomes constant. , The welding quality can be stabilized.
第１図は本発明の一実施例を示す溶接用電源装置の電気
回路図、第２図および第３図は同装置における各部の信
号波形図、第４図は同装置における各部の信号波形比較
図である。 １……溶接トランス、2a,2b……サイリスタ、６……第1
CR回路、９……差動増幅器、10……スイッチ、13……第
2CR回路、15……実効値変換回路、16……溶接電流設定
回路、17……比較増幅器、19……位相制御回路、22……
比較増幅器。FIG. 1 is an electric circuit diagram of a welding power source device showing an embodiment of the present invention, FIGS. 2 and 3 are signal waveform diagrams of respective parts in the same device, and FIG. 4 is a comparison of signal waveforms of respective parts in the same device. It is a figure. 1 ... Welding transformer, 2a, 2b ... Thyristor, 6 ... 1st
CR circuit, 9 ... Differential amplifier, 10 ... Switch, 13 ...
2CR circuit, 15 …… RMS value conversion circuit, 16 …… Welding current setting circuit, 17 …… Comparison amplifier, 19 …… Phase control circuit, 22 ……
Comparison amplifier.
Claims (2)
が接続された溶接トランスと、前記交流電源の電源電圧
が入力され溶接用電源装置における力率による位相遅れ
に比例した電圧関数を作り出す第1CR回路と、前記位相
制御素子の導通を検出する導通検出回路と、前記導通検
出回路の出力によりオフするスイッチと、前記第1CR回
路の出力が前記スイッチを介して入力され前記力率によ
る無効分を作り出す第2CR回路と、前記第1CR回路の出力
と前記第2CR回路の出力がそれぞれ入力されて前記溶接
トランスの二次巻線に流れる溶接電流に対応した電圧を
出力する差動増幅器を備えた溶接電流対応電圧検出装
置。1. A welding transformer in which a primary winding is connected to an AC power source through a phase control element, and a voltage function proportional to a phase delay due to a power factor in a welding power source device when a power source voltage of the AC power source is input. A first CR circuit to produce, a conduction detection circuit that detects conduction of the phase control element, a switch that is turned off by the output of the conduction detection circuit, and an output of the first CR circuit is input via the switch and depends on the power factor. A second CR circuit that creates a reactive component, a differential amplifier that outputs the voltage corresponding to the welding current flowing in the secondary winding of the welding transformer by inputting the output of the first CR circuit and the output of the second CR circuit, respectively. Equipped with a welding current voltage detector.
が接続された溶接トランスと、前記交流電源の電源電圧
が入力され溶接用電源装置における力率による位相遅れ
に比例した電圧関数を作り出す第1CR回路と、前記位相
制御素子の導通を検出する導通検出回路と、前記導通検
出回路の出力によりオフするスイッチと、前記第1CR回
路の出力が前記スイッチを介して入力され前記力率によ
る無効分を作り出す第2CR回路と、前記第1CR回路の出力
と前記第2CR回路の出力がそれぞれ入力されて前記溶接
トランスの二次巻線に流れる溶接電流に対応した電圧を
出力する差動増幅器と、前記差動増幅器の出力電圧から
その実効値を得る実効値変換回路と、溶接電流値を設定
する溶接電流設定回路と、前記実効値変換回路の出力と
前記溶接電流設定回路の出力が入力される比較増幅器
と、前記比較増幅器の出力に基づき前記位相制御素子の
導通位相を制御する位相制御回路を備えてなる溶接用電
源装置。2. A welding transformer in which a primary winding is connected to an AC power source via a phase control element, and a voltage function proportional to a phase delay due to a power factor in a welding power source device when a power source voltage of the AC power source is input. A first CR circuit to produce, a conduction detection circuit that detects conduction of the phase control element, a switch that is turned off by the output of the conduction detection circuit, and an output of the first CR circuit is input via the switch and depends on the power factor. A second CR circuit that produces a reactive component, a differential amplifier that outputs the voltage corresponding to the welding current flowing in the secondary winding of the welding transformer by inputting the output of the first CR circuit and the output of the second CR circuit, respectively. , An effective value conversion circuit for obtaining an effective value from the output voltage of the differential amplifier, a welding current setting circuit for setting a welding current value, an output of the effective value conversion circuit and an output of the welding current setting circuit. There the comparison amplifier input, the welding power supply device including a phase control circuit for controlling the conduction phase of the phase control element based on the output of the comparison amplifier.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61161364A JP2523513B2 (en) | 1986-07-09 | 1986-07-09 | Voltage detector for welding current and power supply for welding |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61161364A JP2523513B2 (en) | 1986-07-09 | 1986-07-09 | Voltage detector for welding current and power supply for welding |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6316879A JPS6316879A (en) | 1988-01-23 |
| JP2523513B2 true JP2523513B2 (en) | 1996-08-14 |
Family
ID=15733682
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP61161364A Expired - Fee Related JP2523513B2 (en) | 1986-07-09 | 1986-07-09 | Voltage detector for welding current and power supply for welding |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2523513B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5310984A (en) * | 1992-11-03 | 1994-05-10 | Hughes Aircraft Company | Line voltage compensation for AC resistance welding systems and the like |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS56114587A (en) * | 1980-02-15 | 1981-09-09 | Matsushita Electric Ind Co Ltd | Constant-current controlling device for resistance welding machine |
| JPS59232679A (en) * | 1983-06-17 | 1984-12-27 | Dengensha Mfg Co Ltd | Method and device for controlling phase of resistance welding machine |
-
1986
- 1986-07-09 JP JP61161364A patent/JP2523513B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6316879A (en) | 1988-01-23 |
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