JPH0329512B2 - - Google Patents
Info
- Publication number
- JPH0329512B2 JPH0329512B2 JP9522282A JP9522282A JPH0329512B2 JP H0329512 B2 JPH0329512 B2 JP H0329512B2 JP 9522282 A JP9522282 A JP 9522282A JP 9522282 A JP9522282 A JP 9522282A JP H0329512 B2 JPH0329512 B2 JP H0329512B2
- Authority
- JP
- Japan
- Prior art keywords
- feeding
- consumable electrode
- wire
- speed
- arc
- 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 44
- 238000000034 method Methods 0.000 claims description 20
- 238000010586 diagram Methods 0.000 description 4
- 238000006243 chemical reaction Methods 0.000 description 3
- 238000001514 detection method Methods 0.000 description 3
- 239000000155 melt Substances 0.000 description 3
- 239000000463 material Substances 0.000 description 2
- 239000011324 bead Substances 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000006073 displacement reaction Methods 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 238000013021 overheating Methods 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K9/00—Arc welding or cutting
- B23K9/06—Arrangements or circuits for starting the arc, e.g. by generating ignition voltage, or for stabilising the arc
- B23K9/067—Starting the arc
- B23K9/0671—Starting the arc by means of brief contacts between the electrodes
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Plasma & Fusion (AREA)
- Mechanical Engineering (AREA)
- Arc Welding Control (AREA)
Description
【発明の詳細な説明】
本発明は消耗性電極を用いる溶接方法の改善に
関するもので、アークスタートを良好にし作業性
および溶接品質の向上を計るものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a welding method using a consumable electrode, and is intended to improve the arc start and improve workability and welding quality.
消耗性電極（以後ワイヤと言う）を用いるアー
ク溶接においては、そのアークスタートを良好に
行うべく種々の改善がなされている。これらのう
ち代表的なものとしては、ワイヤスローダウン
法、ホツトスタート法および高周波スタート法が
ある。ワイヤスローダウン法はアークが発生する
まで（現実には溶接電流が流れ出すまで）はワイ
ヤの送給速度を低く設定しておき（スローダウン
速度）ワイヤが被溶接物に接触して電流が流れ出
すと溶接条件に相当する速度に切替えてワイヤの
送給を行うものである。 In arc welding using a consumable electrode (hereinafter referred to as a wire), various improvements have been made to ensure a good arc start. Typical examples of these include the wire slowdown method, the hot start method, and the high frequency start method. In the wire slowdown method, the wire feeding speed is set low (slowdown speed) until an arc occurs (in reality, until the welding current begins to flow), and then the wire feed speed is set low (slowdown speed) until the wire contacts the workpiece and the current begins to flow. The wire is fed by switching the speed to correspond to the welding conditions.
第１図はこのようなワイヤスローダウン法によ
るアークスタートの一例を示す模式図である。同
図ａは溶接トーチ１から送出されるワイヤ２の状
態を示し、同図ｂはワイヤ送給速度Ｓの変化の様
子、ｃはワイヤ２と被溶接物３との間に供給され
る溶接電源の出力電圧ｅ，ｄはワイヤ２に流れる
電流ｉの変化を示す。また同図は左から右方に向
つて時間が経過していくときを示している。時刻
t0において溶接を開始すると電圧ｅが印加される
とともにワイヤ２がスローダウン速度S1で送給さ
れる。ワイヤ２の先端が被溶接物３に接触するま
では電流ｉは零のままである。時刻t1においてワ
イヤ２の先端が被溶接物３に接触すると電流ｉが
流れ始め、これと同時にこの電流ｉを検出してワ
イヤ送給速度Ｓはスローダウン速度S1から本溶接
時の速度S2に切替えられる。一方、ワイヤ２には
被溶接物３との接触によつて短絡電流が流れてワ
イヤの固有抵抗によつて加熱されるが、この間に
もワイヤは速度S2で送給され続けるために接触は
強固となりワイヤ先端部の接触抵抗はほとんど零
となり、このため先端部の温度上昇は被溶接物３
によつて冷却される分だけ他より低くなる傾向に
ある。このためにワイヤは溶接トーチ１と被溶接
物との中間部分が過熱され、やがて同図に示すよ
うに時刻t2においてこの中間部分から溶断し飛散
する。この溶断位置は比較的被溶接物３の表面か
ら高く、このため溶断時に微少なアークが発生し
てもこれが成長しきれずに再び電流は途絶えてア
ークスタートに失敗する。この後引続いて送給さ
れてくるワイヤ２の先端が時刻t3にて再び被溶接
物に接触すると短絡電流が流れて加熱、溶融、飛
散をくりかえす。このようなことを数回くりかえ
すうちにワイヤの先端および被溶接物が加熱され
てアークが発生しやすくなりようやくアークスタ
ートに至るものである。 FIG. 1 is a schematic diagram showing an example of arc starting using such a wire slowdown method. The figure a shows the state of the wire 2 sent out from the welding torch 1, the figure b shows the change in the wire feeding speed S, and the figure c shows the welding power supply supplied between the wire 2 and the workpiece 3. The output voltages e and d of represent changes in the current i flowing through the wire 2. The figure also shows time passing from left to right. time
When welding starts at t 0 , voltage e is applied and wire 2 is fed at a slowdown speed S 1 . The current i remains zero until the tip of the wire 2 comes into contact with the workpiece 3. When the tip of the wire 2 comes into contact with the workpiece 3 at time t1 , a current i starts flowing, and at the same time this current i is detected, and the wire feeding speed S changes from the slowdown speed S1 to the speed S during main welding. Can be switched to 2 . On the other hand, a short circuit current flows through the wire 2 due to its contact with the workpiece 3, and it is heated by the wire's specific resistance, but during this time the wire continues to be fed at a speed S2 , so the contact is not The wire becomes stronger and the contact resistance at the tip becomes almost zero, so the temperature rise at the tip is reduced to
It tends to be lower than others due to the amount of cooling caused by. For this reason, the wire is overheated at the intermediate portion between the welding torch 1 and the object to be welded, and eventually melts and scatters from this intermediate portion at time t2 as shown in the figure. This fusing position is relatively high from the surface of the object to be welded 3, and therefore, even if a minute arc is generated at the time of fusing, it cannot grow completely and the current is interrupted again, causing failure in arc starting. When the tip of the wire 2 that is subsequently fed comes into contact with the workpiece again at time t3 , a short circuit current flows and heating, melting, and scattering are repeated. As this process is repeated several times, the tip of the wire and the object to be welded heat up, making it easier to generate an arc, and finally the arc starts.
このようなワイヤスローダウン法において、最
初の接触時にアークスタートを得るためには、ス
ローダウン速度を極力遅くして接触を極く軽く行
うようにすればよいが、この速度をあまり遅くす
るとそれだけアークスタートに要する時間が長く
なり作業性を損うことになる。またワイヤの接触
から溶断に至るまでの間も前述のようにワイヤは
送給され続けるため、この送給力が溶接トーチを
押し上げる方向の反力となつて作用し溶接トーチ
を動かしその狙い位置を狂わせてしまうことにな
る。 In this wire slowdown method, in order to obtain an arc start at the first contact, the slowdown speed should be as slow as possible and the contact should be made very lightly; however, if this speed is too slow, the arc will increase. The time required for starting becomes longer, which impairs work efficiency. Furthermore, since the wire continues to be fed as described above from the time the wire comes into contact with the wire until it is fused, this feeding force acts as a reaction force in the direction of pushing up the welding torch, causing the welding torch to move and deviate from its target position. This will result in
また、ホツトスタート法は、スタート時に溶接
電圧を溶接中よりも高い値に設定してワイヤが被
溶接物に接触したときの「溶断」・「アークへの移
行」を改善せんとするものであるが、この方法に
よるときは始動時に供給される電力が過大となる
ために大粒のスパツタの発生が避けられず、また
被溶接物の表面から高い位置でワイヤが溶断して
アーク切れを起こし、再びアークスタート動作を
くりかえすことになる。このために、大粒のスパ
ツタの量が増加し、かつ溶接始端部のビード外観
や溶接品質の劣化を招くことが多い。さらにこの
場合にも、短絡と開放とをくりかえすことによつ
て、作業者の手に反力が加わり溶接トーチを安定
に保持することが難しかつた。さらに高周波スタ
ート法は、ワイヤと被溶接物とを非接触のままア
ークスタートが可能であるが、このためには高周
波高電圧を印加する装置が必要となり、また溶接
トーチ、ケーブル、溶接電源などに高周波高電圧
に耐えるための対策を施すことが必要となる。さ
らに、大きなエネルギーの高周波が空中副射ある
いは電源ラインに混入することによつて周辺機器
に有害なノイズを与えることが避け難く問題の多
い装置となる。 In addition, the hot start method sets the welding voltage at a higher value at the start than during welding, in order to improve ``fusion'' and ``transition to arc'' when the wire contacts the workpiece. However, when this method is used, the electric power supplied at the time of starting is excessive, so the generation of large spatter is unavoidable, and the wire is fused at a high position from the surface of the workpiece, causing an arc breakage and causing the problem to occur again. The arc start operation will be repeated. For this reason, the amount of large spatter increases, and this often causes deterioration in the bead appearance at the welding start end and in the welding quality. Furthermore, in this case as well, the repeated short-circuit and open-circuit causes reaction force to be applied to the operator's hand, making it difficult to stably hold the welding torch. Furthermore, with the high-frequency start method, it is possible to start an arc without contacting the wire and the workpiece, but this requires a device that applies high-frequency, high-voltage, and the welding torch, cable, welding power source, etc. It is necessary to take measures to withstand high frequency and high voltage. Furthermore, it is difficult to avoid causing harmful noise to peripheral equipment due to high-energy high-frequency waves entering the air or entering the power supply line, resulting in a device with many problems.
本発明は上記従来方法の欠点を解決するもので
あつて、アークスタートに際し、比較的遅い速度
でワイヤの送給を開始し、被溶接物と接触した時
点でワイヤの送給を一旦停止させて、アークが発
生して成長するまでの所定時間の後に送給を再開
して、本溶接条件における送給速度にまで移行さ
せるようにした結果、確実なアークスタートを実
現したものである。 The present invention solves the drawbacks of the conventional methods described above, and consists in starting the wire feeding at a relatively slow speed when starting the arc, and once stopping the wire feeding when the wire comes into contact with the workpiece. After a predetermined period of time for the arc to generate and grow, the feed is restarted and the feed speed is brought up to the actual welding conditions, thereby achieving a reliable arc start.
第２図は本発明を実施したときの様子を示す模
式図であり、第１図と同様に同図ａは溶接トーチ
１から送出されるワイヤ２の状態を示し、同図ｂ
はワイヤ送給速度Ｓの変化の様子を、ｃは溶接電
源の出力電圧ｅ，ｄは電流ｉを示す。時刻t0にお
いて溶接開始指令が出されるとワイヤ２は遅い速
度S1で送給を開始し、ワイヤ２が送給されて時刻
t1に被溶接物３に接触すると直ちに停止する。こ
の接触の検出は従来のワイヤスローダウン法にお
けるのと同様に短絡電流を検出することによつて
行うことができる。接触検出によつてワイヤの送
給が停止するために、ワイヤと被溶接物とは極く
軽く接触した状態に保たれることになる。このた
め、ワイヤの固有抵抗よりもワイヤ先端の接触部
の抵抗の方がはるかに大きな値となり、短絡電流
によつて先端部が他の部分よりも速く過熱されて
溶融するに至り、ワイヤ先端部が極くわずか飛散
し、これにともなつて小さなアークが発生する。
このアークの発生によつてワイヤ先端はさらに過
熱されるが、未だワイヤは停止したままであるの
でワイヤの溶融につれてアーク長は伸びて次第に
成長してゆくことになる。このとき電流ｉは短絡
により一時急増するもののワイヤ先端部の過熱に
より実効抵抗が増加し急激に減少して、ワイヤの
溶融時におけるスパツタの発生が防止される。こ
のアークの成長速度はワイヤが停止しているため
に使用するワイヤの材質、太さおよび供給電圧ｅ
によつてほぼ一定の速度となる。このままの状態
を続けると、アークの長さはやがて出力電圧ｅに
よつて維持できる値よりも長くなつてアーク切れ
を起すことになる。そこでこれに達しない少し手
前の時刻t2に、初期速度より若干速い速度S2にて
ワイヤの送給を再開し、アークの消減を防止す
る。その後アークの安定および被溶接物の温度上
昇を待つて時刻t3にワイヤ送給速度を本溶接条件
の速度S3に切替える。このワイヤ停止時間T1＝t2
−t1および送給再開から本溶接条件に切替えるま
での時間T2＝t3−t2は、ワイヤの形状、材質およ
び供給電圧ｅによつてほぼ定まるので、これらの
時間は本溶接における溶接条件にかかわらず略一
定の時間とすることができ、公知のタイマにより
それぞれ設定することができる。なお、供給電圧
ｅは最初から本溶接条件における溶接電圧として
もよいが、本発明においてはワイヤ送給から接触
検出後停止してアークの成長を待つので、アーク
スタートが確実になるからワイヤによつて定まる
スパツタの発生のない低い値に定めることができ
る。またワイヤ送給再開後の速度Ｓおよび供給電
圧ｅの変化は、第２図に実線や一点鎖線にて示し
たように段階的に切替えるようにする他に、同図
に破線や二点鎖線で示すように連続的に変化させ
てもよく、この方がよりスムースなアークスター
トが得られる。 FIG. 2 is a schematic diagram showing the state when the present invention is implemented, and similarly to FIG. 1, the figure a shows the state of the wire 2 sent out from the welding torch 1, and the figure b
shows how the wire feeding speed S changes, c shows the output voltage e of the welding power source, and d shows the current i. When a welding start command is issued at time t 0 , wire 2 starts feeding at a slow speed S 1 , and wire 2 is fed at time t 0.
When it comes into contact with the workpiece 3 at t 1 , it immediately stops. Detection of this contact can be done by detecting the short circuit current as in conventional wire slowdown methods. Since feeding of the wire is stopped upon contact detection, the wire and the workpiece are kept in a very light contact state. For this reason, the resistance of the contact area at the tip of the wire is much larger than the specific resistance of the wire, and the short-circuit current causes the tip to overheat and melt faster than other parts, causing the tip of the wire to melt. A very small amount of light scatters, and a small arc is generated as a result.
The tip of the wire is further overheated by the generation of this arc, but since the wire remains stationary, the length of the arc increases and gradually grows as the wire melts. At this time, although the current i temporarily increases rapidly due to the short circuit, the effective resistance increases due to overheating of the tip of the wire, and the current i rapidly decreases, thereby preventing the generation of spatter when the wire melts. The growth rate of this arc depends on the wire material, thickness, and supply voltage e since the wire is stopped.
The speed becomes almost constant. If this state continues, the length of the arc will eventually become longer than the value that can be maintained by the output voltage e, and arc breakage will occur. Therefore, at time t2 , a little before reaching this point, wire feeding is restarted at a speed S2 slightly higher than the initial speed to prevent the arc from disappearing. Thereafter, after waiting for the arc to become stable and the temperature of the workpiece to be welded to rise, at time t3 , the wire feeding speed is switched to the speed S3 of the main welding conditions. This wire stop time T 1 = t 2
−t 1 and the time T 2 = t 3 −t 2 from restarting feeding to switching to the main welding conditions are approximately determined by the wire shape, material, and supply voltage e, so these times are It can be set to a substantially constant time regardless of the conditions, and can be set using a known timer. Note that the supply voltage e may be the welding voltage under the present welding conditions from the beginning, but in the present invention, the wire feed is stopped after contact detection and waits for the arc to grow, so the arc start is ensured. It is possible to set the value to a low value that does not cause the occurrence of spatter. In addition, changes in the speed S and supply voltage e after resuming wire feeding are changed in stages as shown in the solid line and the dashed-dotted line in Fig. It may be changed continuously as shown, and a smoother arc start can be obtained in this case.
以上のように本発明においては、ワイヤが最初
に被溶接物に接触したときにワイヤの先端から確
実にアークを発生するこができるのでスパツタの
発生がほとんどなく、またアークスタート時にワ
イヤの送給力によつて溶接トーチに作用する反力
がほとんどないのでトーチの位置ずれが発生する
ことがなくなることと相まつて溶接始端部におけ
る溶接欠陥の発生を完全に防止することができ
る。 As described above, in the present invention, an arc can be reliably generated from the tip of the wire when the wire first contacts the workpiece, so there is almost no spatter, and the feeding force of the wire is reduced at the time of starting the arc. As a result, there is almost no reaction force acting on the welding torch, which eliminates the possibility of positional displacement of the torch and completely prevents welding defects from occurring at the welding start end.
第１図ａないしｄはそれぞれ従来のワイヤスロ
ーダウン法におけるアークスタート時の様子を示
す説明図、第２図ａないしｄはそれぞれ本発明を
実施したときのアークスタート時の様子を示す説
明図である。
１……溶接トーチ、２……消耗性電極（ワイ
ヤ）、３……被溶接物。
Figures 1a to d are explanatory diagrams showing the state at arc start in the conventional wire slowdown method, respectively, and Figures 2 a to d are explanatory diagrams each showing the state at arc start when the present invention is implemented. be. 1... Welding torch, 2... Consumable electrode (wire), 3... Welding object.
Claims (1)
被溶接物に送給するアーク溶接方法において、溶
接の開始に際して消耗性電極と被溶接物との間に
電圧を印加するとともに、比較的遅い送給速度で
消耗性電極を送給し、消耗性電極と被溶接物とが
接触したときにこれを検出して送給を一旦停止せ
しめ、送給停止後所定の時間の後に送給を再開
し、送給再開後さらに所定の時間の後に送給速度
を本溶接条件に相当する値にまで変化させるアー
ク溶接方法。 ２ 前記消耗性電極の送給を再開した後は、送給
速度を初期の送給速度よりも速い速度に変化させ
るものとした特許請求の範囲第１項に記載のアー
ク溶接方法。 ３ 前記消耗性電極の送給を再開した後は、送給
速度を送給再開から所定の時間の間に本溶接にお
ける送給速度にまで連続的に加速するものとした
特許請求の範囲第１項または第２項のいずれかに
記載のアーク溶接方法。 ４ 前記被溶接物と消耗性電極との間に供給する
電圧は、消耗性電極の送給開始から一旦停止後再
開するまでは使用する消耗性電極に対応して定ま
りかつ本溶接時とは無関係な比較的低い電圧と
し、消耗性電極の送給再開後は初期の供給電圧よ
りも高い値に変化させる特許請求の範囲第１項な
いし第３項のいずれかに記載のアーク溶接方法。 ５ 前記消耗性電極の送給を再開した後は、消耗
性電極と被溶接物との間に供給する電圧を送給再
開から所定の時間の間に初期の電圧から本溶接に
おける値にまで連続的に上昇させるものである特
許請求の範囲第１項ないし第４項のいずれかに記
載のアーク溶接方法。[Claims] 1. In an arc welding method in which a consumable electrode is fed to a workpiece at a predetermined constant speed, a voltage is applied between the consumable electrode and the workpiece at the start of welding, and , the consumable electrode is fed at a relatively slow feeding speed, and when the consumable electrode comes into contact with the object to be welded, this is detected and the feeding is temporarily stopped, and after a predetermined period of time has elapsed after the feeding has stopped. An arc welding method in which feeding is restarted and the feeding speed is changed to a value corresponding to the main welding conditions after a predetermined period of time after restarting feeding. 2. The arc welding method according to claim 1, wherein after restarting the feeding of the consumable electrode, the feeding speed is changed to a faster speed than the initial feeding speed. 3. After resuming the feeding of the consumable electrode, the feeding speed is continuously accelerated to the feeding speed for main welding within a predetermined time after restarting the feeding. The arc welding method according to any one of Items 1 and 2. 4. The voltage supplied between the workpiece and the consumable electrode is determined according to the consumable electrode used from the start of supply of the consumable electrode until it is restarted after it is stopped, and is independent of the actual welding. The arc welding method according to any one of claims 1 to 3, wherein the voltage is set to a relatively low voltage and is changed to a higher value than the initial supply voltage after resuming supply of the consumable electrode. 5 After restarting the supply of the consumable electrode, the voltage supplied between the consumable electrode and the workpiece shall be continuously increased from the initial voltage to the value for main welding within a predetermined period of time from the restart of supply. 5. The arc welding method according to any one of claims 1 to 4, wherein the arc welding method increases the temperature.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9522282A JPS58212872A (en) | 1982-06-02 | 1982-06-02 | Arc welding method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP9522282A JPS58212872A (en) | 1982-06-02 | 1982-06-02 | Arc welding method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS58212872A JPS58212872A (en) | 1983-12-10 |
| JPH0329512B2 true JPH0329512B2 (en) | 1991-04-24 |
Family
ID=14131713
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP9522282A Granted JPS58212872A (en) | 1982-06-02 | 1982-06-02 | Arc welding method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS58212872A (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01138063A (en) * | 1987-11-20 | 1989-05-30 | Osaka Denki Co Ltd | Method and device for starting arc of dc arc welding |
| US6627850B1 (en) | 1999-03-18 | 2003-09-30 | Kabushiki Kaisha Yaskawa Denki | Consumable electrode type arc welding method and device therefor |
| EP2269758B1 (en) * | 2009-07-03 | 2017-05-17 | Ewm Ag | DC arc welding method |
-
1982
- 1982-06-02 JP JP9522282A patent/JPS58212872A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS58212872A (en) | 1983-12-10 |
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