JPH0435010Y2 - - Google Patents
Info
- Publication number
- JPH0435010Y2 JPH0435010Y2 JP3557889U JP3557889U JPH0435010Y2 JP H0435010 Y2 JPH0435010 Y2 JP H0435010Y2 JP 3557889 U JP3557889 U JP 3557889U JP 3557889 U JP3557889 U JP 3557889U JP H0435010 Y2 JPH0435010 Y2 JP H0435010Y2
- Authority
- JP
- Japan
- Prior art keywords
- welding
- voltage
- nozzle
- contact
- absolute value
- 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
Links
- 238000003466 welding Methods 0.000 claims description 51
- 239000003990 capacitor Substances 0.000 claims description 2
- 238000001514 detection method Methods 0.000 claims 7
- 238000007796 conventional method Methods 0.000 claims 1
- 230000007423 decrease Effects 0.000 claims 1
- 230000000694 effects Effects 0.000 claims 1
- 230000004941 influx Effects 0.000 claims 1
- 230000007257 malfunction Effects 0.000 claims 1
- 238000000034 method Methods 0.000 claims 1
Landscapes
- Arc Welding Control (AREA)
- Resistance Welding (AREA)
Description
第１図は本考案の実施例を示す回路である。
２……溶接ノズル、３……リレー、４……定電
圧電源、５……溶接電圧、６……絶対値回路、７
……比較器、８……電流制限用抵抗、９……ワー
ク、１０……入力抵抗、１１……抵抗、１２……
コンデンサ。
FIG. 1 shows a circuit showing an embodiment of the present invention. 2... Welding nozzle, 3... Relay, 4... Constant voltage power supply, 5... Welding voltage, 6... Absolute value circuit, 7
... Comparator, 8 ... Current limiting resistor, 9 ... Work, 10 ... Input resistance, 11 ... Resistor, 12 ...
capacitor.
Claims (1)
の絶対値回路の出力を設定値と比較して検知信号
を発生する比較器、定電圧源、この定電圧源の電
圧と交流溶接電圧を上記溶接ノズルに切換え印加
するリレーを有し、上記リレーは溶接ON信号に
より付勢されて前記交流溶接電圧を選択すること
を特徴とするノズル接触検知装置。 上説〔産業上の利用分野〕 本考案は交流アーク溶接を行う溶接ロボツトに
おける溶接ノズルとワークの接触を検知する装置
に関する。 〔従来の技術〕 従来のこの種の装置は、溶接ノズルとワーク間
に所定電圧を印加しておき、溶接ノズルがワーク
に接触すると両者間の電圧が低下するので、この
電圧低下を検出することにより、溶接ノズルとワ
ークとの接触を検知する方法（例えば、実開昭58
−111172号）を採つていた。 〔考案が解決しようとする課題〕 ところが、交流溶接においては、正極溶接時に
はチツプがワークより低電位になるため、スパツ
タにより溶接ノズルとチツプが短絡した場合、溶
接ノズルからチツプに向けて電流が流れるため
に、上記比較器が出力してしまい、溶接ノズル−
チツプ間のスパツタによる短絡をノズル接触とし
て誤検知する等、交流溶接中は、その信頼性が充
分でないという問題がある上、上記スパツタによ
る上記短絡時、電位差によつては、過電流が流
れ、回路が焼損するといつた危険があつた。 本考案は上記問題を解消するためになされたも
ので、非溶接時は勿論のこと、交流溶接中におけ
るノズル接触を安全・確実に検知することができ
る信頼性の高いノズル接触検知装置を提供するこ
とを目的とする。 〔課題を解決するための手段〕 本考案は上記目的を達成するため、溶接ノズル
の電圧を導入される絶対値回路、この絶対値回路
の出力を設定値と比較して検知信号を発生する比
較器、定電圧源、この定電圧源の電圧と溶接電圧
を上記溶接ノズルに切換え印加するリレーからな
り、上記リレーは溶接ON信号により定電圧源か
ら、交流溶接電圧側に切換わる構成としたもので
ある。 〔作用〕 本考案では、溶接ノズルの電圧が、絶対値回路
を通して監視され、上記電圧が負であつても、正
の電圧に変換されて比較器に入力されるから、前
記したスパツタ時の誤動作は無くなるとともに過
大電流の流入も防止される。 〔実施例〕 以下、本考案の１実施例を図面を参照して説明
する。 第１図において、１は交流溶接機のチツプ、２
は溶接ノズル、３はリレーの接点である。このリ
レーは溶接ON信号によつて付勢されて、定電圧
源４側の接点から溶接電圧５側の接点側へ切
換わる。６は絶対値回路、７は比較器、８は電流
制限用抵抗、９はワークである。１０は入力抵
抗、１１は抵抗、１２はコンデンサである。 この構成において、非溶接時は、リレーの接点
３が側にあるので、溶接ノズル２には定電圧源
４の電圧Ｅ（正の電圧）が印加されており、溶接
ノズル２に印加されているこの電圧Ｅが絶対値回
路６を通して比較器７で、設定値Ekと比較され
る。 従つて、溶接ノズル２が、アース電位にあるワ
ーク９と接触して、溶接ノズル２の電位が低下す
ると、絶対値回路６の出力が設定電圧Ek以下と
なるので、比較器７は接触検知信号を発生する。 溶接が開始されると、溶接ON信号によりリレ
ーの接点３が側へ切換わるので、アーク電圧Ｖ
が抵抗８を通して溶接ノズル２に印加される。正
極性溶接では、チツプ１、溶接ノズル２の電圧は
負の電圧であるが、溶接ノズル２のこの負の電圧
は絶対値回路６で正の電圧に極性変換されて比較
器７に入力される。このため、前記したスパツタ
による溶接ノズル２とチツプ１の短絡が発生して
も、絶対値回路７の出力が設定値Ek以下に低下
しないので、誤検出は停止され、かつ、前記した
過大電流の流入は起こらない。逆極性溶接では、
チツプ１、溶接ノズル２の電圧は正の電圧であ
る。 正極性溶接、逆極性溶接において、溶接ノズル
２がアース電位にあるワーク９に接触した場合に
は、絶対値回路６の出力が設定値Ek以下に低下
するので、比較器７が接触検知信号を発生する。 なお、本考案を適用する交流溶接は、直流電圧
の極性を正極と逆極とを交互に出力するものを含
む。 〔考案の効果〕 本考案は以上説明した通り、溶接ノズルの電圧
を絶対値回路を通して比較器で設定値と比較する
ので、非溶接時は勿論のこと、交流溶接中のノズ
ル接触を安全・確実に検知することができ、従来
に比し、信頼性を向上することができる。[Claims for Utility Model Registration] An absolute value circuit into which the voltage of the welding nozzle is introduced, a comparator that generates a detection signal by comparing the output of this absolute value circuit with a set value, a constant voltage source, and a constant voltage source of this constant voltage source. A nozzle contact detection device comprising a relay that selectively applies a voltage and an AC welding voltage to the welding nozzle, the relay being energized by a welding ON signal to select the AC welding voltage. Above [Industrial Application Field] The present invention relates to a device for detecting contact between a welding nozzle and a workpiece in a welding robot that performs AC arc welding. [Prior Art] In conventional devices of this type, a predetermined voltage is applied between the welding nozzle and the workpiece, and when the welding nozzle comes into contact with the workpiece, the voltage between the two drops, so this voltage drop cannot be detected. A method of detecting contact between a welding nozzle and a workpiece by
−111172). [Problem to be solved by the invention] However, in AC welding, the tip has a lower potential than the workpiece during positive electrode welding, so if the welding nozzle and the tip are shorted by spatter, current will flow from the welding nozzle to the tip. As a result, the above comparator outputs an output, causing the welding nozzle to
There is a problem that reliability is insufficient during AC welding, such as a short circuit caused by spatter between chips being mistakenly detected as nozzle contact, and when the short circuit caused by the spatter occurs, an overcurrent may flow depending on the potential difference. There was a danger that the circuit would burn out. The present invention was made to solve the above problems, and provides a highly reliable nozzle contact detection device that can safely and reliably detect nozzle contact not only during non-welding but also during AC welding. The purpose is to [Means for Solving the Problems] In order to achieve the above object, the present invention includes an absolute value circuit into which the voltage of the welding nozzle is introduced, and a comparison that generates a detection signal by comparing the output of this absolute value circuit with a set value. It consists of a constant voltage source, a relay that switches and applies the voltage of this constant voltage source and the welding voltage to the welding nozzle, and the relay is configured to switch from the constant voltage source to the AC welding voltage side by the welding ON signal. It is. [Operation] In the present invention, the voltage of the welding nozzle is monitored through the absolute value circuit, and even if the voltage is negative, it is converted to a positive voltage and input to the comparator, so that the above-mentioned malfunction at the time of spatter is avoided. is eliminated, and the inflow of excessive current is also prevented. [Embodiment] Hereinafter, one embodiment of the present invention will be described with reference to the drawings. In Figure 1, 1 is the chip of an AC welding machine, 2
is a welding nozzle, and 3 is a relay contact. This relay is energized by the welding ON signal and switches from the contact on the constant voltage source 4 side to the contact on the welding voltage 5 side. 6 is an absolute value circuit, 7 is a comparator, 8 is a current limiting resistor, and 9 is a workpiece. 10 is an input resistor, 11 is a resistor, and 12 is a capacitor. In this configuration, when not welding, the contact 3 of the relay is on the side, so the voltage E (positive voltage) of the constant voltage source 4 is applied to the welding nozzle 2; This voltage E is passed through an absolute value circuit 6 and is compared with a set value Ek by a comparator 7. Therefore, when the welding nozzle 2 comes into contact with the workpiece 9 at ground potential and the potential of the welding nozzle 2 decreases, the output of the absolute value circuit 6 becomes less than the set voltage Ek, so the comparator 7 outputs a contact detection signal. occurs. When welding starts, the welding ON signal switches contact 3 of the relay to the side, so the arc voltage V
is applied to the welding nozzle 2 through the resistor 8. In positive polarity welding, the voltage at the tip 1 and the welding nozzle 2 is a negative voltage, but this negative voltage at the welding nozzle 2 is polarized into a positive voltage by the absolute value circuit 6 and input to the comparator 7. . Therefore, even if a short circuit occurs between the welding nozzle 2 and the chip 1 due to the spatter described above, the output of the absolute value circuit 7 will not fall below the set value Ek, so false detection will be stopped and the above-mentioned overcurrent will be prevented. No influx will occur. In reverse polarity welding,
The voltages of the chip 1 and the welding nozzle 2 are positive voltages. During positive polarity welding and reverse polarity welding, if the welding nozzle 2 comes into contact with the workpiece 9 at ground potential, the output of the absolute value circuit 6 will drop below the set value Ek, so the comparator 7 will detect the contact detection signal. Occur. Note that AC welding to which the present invention is applied includes those in which the polarity of the DC voltage is alternately output as positive and reverse. [Effects of the invention] As explained above, this invention compares the voltage of the welding nozzle with the set value using a comparator through an absolute value circuit, so the nozzle contact is safe and reliable not only when not welding but also during AC welding. can be detected, and reliability can be improved compared to conventional methods.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3557889U JPH0435010Y2 (en) | 1989-03-30 | 1989-03-30 |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3557889U JPH0435010Y2 (en) | 1989-03-30 | 1989-03-30 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH02127370U JPH02127370U (en) | 1990-10-19 |
| JPH0435010Y2 true JPH0435010Y2 (en) | 1992-08-19 |
Family
ID=31541053
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3557889U Expired JPH0435010Y2 (en) | 1989-03-30 | 1989-03-30 |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0435010Y2 (en) |
-
1989
- 1989-03-30 JP JP3557889U patent/JPH0435010Y2/ja not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| JPH02127370U (en) | 1990-10-19 |
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