JPH03142075A - Plasma arc machine - Google Patents

Plasma arc machine

Info

Publication number
JPH03142075A
JPH03142075A JP28044889A JP28044889A JPH03142075A JP H03142075 A JPH03142075 A JP H03142075A JP 28044889 A JP28044889 A JP 28044889A JP 28044889 A JP28044889 A JP 28044889A JP H03142075 A JPH03142075 A JP H03142075A
Authority
JP
Japan
Prior art keywords
pilot arc
current
circuit
power source
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.)
Pending
Application number
JP28044889A
Other languages
Japanese (ja)
Inventor
Akihiko Kitajima
北島 明彦
Seigo Hagiwara
萩原 清吾
Mitsunori Akaishi
三徳 赤石
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Panasonic Holdings Corp
Original Assignee
Matsushita Electric Industrial Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Matsushita Electric Industrial Co Ltd filed Critical Matsushita Electric Industrial Co Ltd
Priority to JP28044889A priority Critical patent/JPH03142075A/en
Publication of JPH03142075A publication Critical patent/JPH03142075A/en
Pending legal-status Critical Current

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  • Arc Welding Control (AREA)

Abstract

PURPOSE:To maintain a pilot arc current constant and to prevent burning of a circuit by arranging a current detector on a pilot arc circuit by using a variable power source for a DC power source and providing a control circuit which inputs its output signal and a proper reference value of a command signal source and controls a current value of the variable power source. CONSTITUTION:The current detector 8 detects the change of the pilot arc current Ip and outputs its current value (i) to the control circuit 9. The control circuit 9 compares the output of the current detector 8 with the proper reference value commanded by the command signal source 10 and outputs a control signal C to the variable power source 1 so as to reduce the pilot arc current when it exceeds a specified value. In addition, when the output of the current detector 8 is less than a specified value shown by the command signal source 10, since the control circuit 9 outputs the control signal C to the variable power source 1 so as to increase the pilot arc current, the pilot arc current is maintained constant, hence burning of the pilot arc circuit can be prevented.

Description

【発明の詳細な説明】 産業上の利用分野 本発明は、パイロットアーク回路付きプラズマアーク加
工装置に関するものである。
DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a plasma arc processing apparatus with a pilot arc circuit.

従来の技術 従来のパイロットアーク回路付きプラズマアーク加工装
置の構成図を第2図に示すが、起動スイッチ2を投入す
ると、電源11の出力が電極3、ノズルチップ4、被加
工物5の間に供給され、次いで駆動スイッチ2を投入し
たことにより高周波発生回路7が駆動して高周波電圧が
電源11の出力に重畳して電極3とノズルチップ4との
間に印加されると電極3とノズルチップ4間の絶縁が破
壊されるため、電極3とノズルチップ4の間にパイロッ
トアークが発生する。パイロットアーク電流1pはノズ
ルチップ4−電極3−高周波発生装置7−起動スイッチ
2−電源11−制限抵抗6で構成される閉回路に流れる
2. Description of the Related Art A configuration diagram of a conventional plasma arc machining apparatus with a pilot arc circuit is shown in FIG. Then, when the drive switch 2 is turned on, the high frequency generation circuit 7 is driven and a high frequency voltage is superimposed on the output of the power supply 11 and applied between the electrode 3 and the nozzle tip 4. Since the insulation between the electrodes 3 and 4 is broken, a pilot arc is generated between the electrodes 3 and the nozzle tips 4. The pilot arc current 1p flows through a closed circuit composed of the nozzle tip 4, the electrode 3, the high frequency generator 7, the starting switch 2, the power source 11, and the limiting resistor 6.

次いでパイロットアークを被加工物5に近ずけるとパイ
ロットアークが被加工物5に移行し、電極3と被加工物
5の間に主プラズマアークが発生するのでプラズマアー
クにより加工することができる。
Next, when the pilot arc is brought close to the workpiece 5, the pilot arc moves to the workpiece 5, and a main plasma arc is generated between the electrode 3 and the workpiece 5, so that processing can be performed using the plasma arc.

発明が解決しようとする課題 従来のパイロットアーク回路付きプラズマア−ク加工装
置においては、パイロットアーク発生時には電源11は
単に定電圧源として働いており、パイロットアーク電流
1pは下式によって示される。
Problems to be Solved by the Invention In a conventional plasma arc processing apparatus with a pilot arc circuit, the power supply 11 simply functions as a constant voltage source when a pilot arc is generated, and the pilot arc current 1p is expressed by the following equation.

上式においてパイロットアーク電圧は電極3とノズルチ
ップ4の間の距離にほぼ比例して変化し、電源11の電
圧及び制限抵抗6の抵抗値はある一定の数値である。従
ってパイロットアーク電流rpは電極3とノズルチップ
4の間の距離によって変化する。そのため電極3が消耗
して電極3とノズルデツプ4の間の距離が大きくなると
、パイロットアーク電流rpが小さくなりパイロットア
ークが被加工物5に移行し難くなり主プラズマアークが
発生しないことがある。また電極3とノズルチップ4の
間の距離が小さくなるとパイロットアーク電流tpが過
大になり制限抵抗6及びパイロットアーク回路を焼損す
る場合もあった。
In the above equation, the pilot arc voltage changes approximately in proportion to the distance between the electrode 3 and the nozzle tip 4, and the voltage of the power source 11 and the resistance value of the limiting resistor 6 are constant values. Therefore, the pilot arc current rp changes depending on the distance between the electrode 3 and the nozzle tip 4. Therefore, when the electrode 3 is worn out and the distance between the electrode 3 and the nozzle depth 4 becomes large, the pilot arc current rp becomes small, making it difficult for the pilot arc to transfer to the workpiece 5, and the main plasma arc may not be generated. Further, when the distance between the electrode 3 and the nozzle tip 4 becomes small, the pilot arc current tp becomes excessive, and the limiting resistor 6 and the pilot arc circuit may be burned out.

課題を解決するための手段 本発明は上記課題を解決するために、直流電源として可
変電源を用いると共にパイロットアーク回路にパイロッ
トアーク電流値を検出する電流検出装置を配し、且つ前
記電流検出装置の出力信号と適正基準値を指令する指令
信号源の出力指令値とを入力し、これらにもとすき前記
可変電源の電流値を制御する制御回路を備えたものであ
る。
Means for Solving the Problems In order to solve the above-mentioned problems, the present invention uses a variable power source as a DC power source, disposes a current detection device for detecting a pilot arc current value in the pilot arc circuit, and further improves the current detection device. A control circuit is provided for inputting an output signal and an output command value of a command signal source for commanding an appropriate reference value, and for controlling the current value of the variable power supply.

作   用 電流検出装置はパイロットアーク電流の変化を検出し、
その電流値を制御回路に出力するので、制御回路は電流
検出装置の出力と指令信号源が指令する適正基準値と比
較して一定値を越えれば可変電源に対しパイロットアー
ク電流を減少させるように制御信号を出力し、また電流
検出装置の出力が指令信号源の示す一定値以下であれば
制御回路は可変電源に対しパイロットアーク電流を増大
させるように制御信号を出力することによってパイロッ
トアーク電流は一定に保たれる。以上のようにパイロッ
トアーク電流を一定に保つ制御を行うことにより、電極
とノズルチップとの間の距離が変化しても安定したパイ
ロットアークの点弧が可能となり、従ってパイロットア
ークの被加工物への移行が確実となる。
The working current detection device detects changes in the pilot arc current,
The current value is output to the control circuit, so the control circuit compares the output of the current detection device with the appropriate reference value commanded by the command signal source and instructs the variable power supply to reduce the pilot arc current if it exceeds a certain value. The control circuit outputs a control signal, and if the output of the current detection device is below a certain value indicated by the command signal source, the control circuit outputs a control signal to the variable power supply to increase the pilot arc current, thereby reducing the pilot arc current. is kept constant. By controlling the pilot arc current to a constant value as described above, it is possible to stably ignite the pilot arc even if the distance between the electrode and the nozzle tip changes. The transition will be ensured.

実施例 本発明の実施例を第1図にもとすき説明する。第1図は
パイロットアーク回路付きプラズマアーク加工装置の全
体構成を示すものであるが、パイロットアーク回路に挿
入した電流検出装置8はパイロットアーク電流1pの値
を検出し、その出力を信号iとして制御回路9に入力し
、同時に指令信号源10は基準となる適正値を指令(直
rとして制御回路9に人力する。制御回路9は信号iと
指令値rを比較し制御信号Cを出力して可変電源lを制
御するものである。
Embodiment An embodiment of the present invention will be explained below with reference to FIG. Figure 1 shows the overall configuration of a plasma arc processing device with a pilot arc circuit. A current detection device 8 inserted into the pilot arc circuit detects the value of the pilot arc current 1p, and controls the output using the signal i. At the same time, the command signal source 10 inputs an appropriate reference value to the control circuit 9 as a command (direct r).The control circuit 9 compares the signal i and the command value r and outputs a control signal C. It controls the variable power supply l.

この回路構成において、起動スイッチ2を投入すると可
変電源lの出力が電極3とノズルチップ4及び被加工物
5との間に印加されると共に、起動スイッチ2を投入し
たことにより高周波発生装置7が駆動し高周波電圧が電
極3とノズルチップ4の間に重畳される。電極3とノズ
ルチップ4との間の絶縁が高周波電圧により破壊される
と電極3とノズルチップ4の間にパイロットアークが発
生し、ノズルチップ4−電極3−高周波発生装置7−起
動スイッチ2−可変電源1−電流検出装置8で構成され
る閉回路にパイロットアーク電流rpが流れ、電流検出
装置8はパイロットアーク電流Ipの電流値を検出し、
制御回路に対して信号iを出力する。制御回路9は信号
iと指令信号源10から出力される指令値rを入力とし
て、電源lに対して制御信号Cを出力するが、「信号i
〉指令値r」である場合には、制御回路9は電源1に対
して「減少」制御信号を出力し、「減少」制御信号を入
力さされた電源1は出力を制限してパイロットアーク電
流1pを減少させる。一方、「信号i〈指令値「」であ
る場合には制御回路9は電源1に対して「増大」制御信
号を出力し、「増大」制御信号を人力された電源lは出
力を増してパイロットアーク電流1pを増大させる。
In this circuit configuration, when the start switch 2 is turned on, the output of the variable power supply 1 is applied between the electrode 3, the nozzle tip 4, and the workpiece 5, and when the start switch 2 is turned on, the high frequency generator 7 is activated. A driving high frequency voltage is superimposed between the electrode 3 and the nozzle tip 4. When the insulation between the electrode 3 and the nozzle tip 4 is broken by the high frequency voltage, a pilot arc is generated between the electrode 3 and the nozzle tip 4, and the nozzle tip 4 - electrode 3 - high frequency generator 7 - starting switch 2 - A pilot arc current rp flows through a closed circuit composed of a variable power source 1 and a current detection device 8, and the current detection device 8 detects the current value of the pilot arc current Ip,
A signal i is output to the control circuit. The control circuit 9 inputs the signal i and the command value r output from the command signal source 10 and outputs the control signal C to the power supply l.
〉Command value r”, the control circuit 9 outputs a “decrease” control signal to the power supply 1, and the power supply 1 to which the “decrease” control signal is input limits its output and reduces the pilot arc current. Decrease 1p. On the other hand, if "signal i<command value", the control circuit 9 outputs an "increase" control signal to the power supply 1, and the power supply l to which the "increase" control signal was manually input increases its output and pilots the Increase arc current 1p.

以上の通り本発明によるパイロットアーク回路付きプラ
ズマアーク加工装置においては、上記作動を行うことに
より「信号i−指令値rJとなるようなパイロットアー
ク電流1pを保つ働きをするので、電極3の消耗等によ
り電極3とノズルチップ4の間の距離が変化した場合に
おいても常に安定した一定電流のパイロットアークが発
生する。
As described above, in the plasma arc machining apparatus with a pilot arc circuit according to the present invention, by carrying out the above operation, the pilot arc current 1p that becomes "signal i - command value rJ" is maintained, so that the electrode 3 is not worn out. Therefore, even when the distance between the electrode 3 and the nozzle tip 4 changes, a pilot arc with a stable constant current is always generated.

発明の効果 本発明によるパイロットアーク回路付きプラズマアーク
加工装置によれば、パイロットアーク電流が一定となり
常に安定したパイロットアークが発生するので、パイロ
ットアークの被加工物への移行がより確実となり主プラ
ズマアークの発生がスムーズとなる。また電極とノズル
チップ間の距離が極めて小さくなった場合においてもパ
イロ・ントアーク電流が一定に保たれるのでパイロット
アーク回路の焼損を防止することができる。尚パイロッ
トアーク回路に制限抵抗を挿入してパイロットアーク電
流を制限する必要がなくなるため制限抵抗が不要も発生
する
Effects of the Invention According to the plasma arc machining apparatus with a pilot arc circuit according to the present invention, the pilot arc current is constant and a stable pilot arc is always generated, so the transfer of the pilot arc to the workpiece is more reliable, and the main plasma arc occurs smoothly. Further, even when the distance between the electrode and the nozzle tip becomes extremely small, the pilot arc current is kept constant, so burning out of the pilot arc circuit can be prevented. In addition, there is no need to insert a limiting resistor into the pilot arc circuit to limit the pilot arc current, so there is no need for a limiting resistor.

【図面の簡単な説明】[Brief explanation of the drawing]

第1図は本発明の実施例を示す構成図、第2図は従来例
の構成図である。
FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a block diagram of a conventional example.

Claims (1)

【特許請求の範囲】[Claims] (1)電極とノズルチップの間にパイロットアークを発
生させるパイロットアーク回路を備えたプラズマアーク
加工装置において、直流電源として可変電源を用いると
共にパイロットアーク回路にパイロットアーク電流値を
検出する電流検出装置を配し、且つ前記電流検出装置の
出力信号と適正基準値とを指令する指令信号源の出力指
令値を入力とし、これらにもとずき前記可変電源の電流
値を制御する制御回路を備えたことを特徴とするプラズ
マアーク加工装置。
(1) In a plasma arc processing device equipped with a pilot arc circuit that generates a pilot arc between the electrode and the nozzle tip, a variable power source is used as the DC power source, and a current detection device that detects the pilot arc current value is installed in the pilot arc circuit. and a control circuit that receives as input an output command value of a command signal source that commands the output signal of the current detection device and an appropriate reference value, and controls the current value of the variable power source based on these. A plasma arc processing device characterized by:
JP28044889A 1989-10-26 1989-10-26 Plasma arc machine Pending JPH03142075A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP28044889A JPH03142075A (en) 1989-10-26 1989-10-26 Plasma arc machine

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP28044889A JPH03142075A (en) 1989-10-26 1989-10-26 Plasma arc machine

Publications (1)

Publication Number Publication Date
JPH03142075A true JPH03142075A (en) 1991-06-17

Family

ID=17625201

Family Applications (1)

Application Number Title Priority Date Filing Date
JP28044889A Pending JPH03142075A (en) 1989-10-26 1989-10-26 Plasma arc machine

Country Status (1)

Country Link
JP (1) JPH03142075A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2015062912A (en) * 2013-09-24 2015-04-09 株式会社ダイヘン Plasma arc welding system

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS61219474A (en) * 1985-03-23 1986-09-29 Osaka Denki Kk Controlling method for stabilization of plasma arc in plasma arc cutting and its device

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS61219474A (en) * 1985-03-23 1986-09-29 Osaka Denki Kk Controlling method for stabilization of plasma arc in plasma arc cutting and its device

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2015062912A (en) * 2013-09-24 2015-04-09 株式会社ダイヘン Plasma arc welding system

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