JPH0671658B2 - Consumable electrode arc welding equipment - Google Patents
Consumable electrode arc welding equipmentInfo
- Publication number
- JPH0671658B2 JPH0671658B2 JP13609084A JP13609084A JPH0671658B2 JP H0671658 B2 JPH0671658 B2 JP H0671658B2 JP 13609084 A JP13609084 A JP 13609084A JP 13609084 A JP13609084 A JP 13609084A JP H0671658 B2 JPH0671658 B2 JP H0671658B2
- Authority
- JP
- Japan
- Prior art keywords
- wire
- consumable electrode
- circuit
- electrode wire
- command signal
- 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 - Lifetime
Links
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
- B23K9/0672—Starting the arc without direct contact between electrodes
-
- 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
- B23K9/12—Automatic feeding or moving of electrodes or work for spot or seam welding or cutting
- B23K9/124—Circuits or methods for feeding welding wire
- B23K9/125—Feeding of 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】 産業上の利用分野 本発明は消耗電極ワイヤを用いるアーク溶接装置の改良
に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of an arc welding apparatus using a consumable electrode wire.
従来技術 消耗電極ワイヤを用いる自動アーク溶接におけるアーク
起動の方法としては、電極ワイヤに溶接用の高出力を印
加した状態で比較的低速で送給を開始し、電極ワイヤと
被溶接物とが接触したときに流れる大きな短絡電流によ
つて電極ワイヤの先端を溶融飛散させてアークに移行さ
せるワイヤスローダウン方式や電極ワイヤと被溶接物と
の間に溶接電源出力の他に高周波の高電圧を印加して両
者間の空隙の絶縁を破壊してアークスタートを行う方式
のものが行なわれている。しかしこれらのうち前者はア
ークスタートの成功率が悪く、特にサブマージアーク溶
接のように太い電極ワイヤを用いるときやアルミニユー
ムのように固有抵抗が小さく短絡電流による抵抗発熱が
少ないワイヤを用いるときにはアークの発生が極端に難
しかつた。また後者の方法によるときは機器の絶縁耐力
の強化を要するのみならず高周波雑音の混入による自身
の誤動作や周辺機器への誘導障害がさけられず、実用上
多くの問題があつた。そこで、これらの改善策として電
極ワイヤを被溶接物に接触するまで送給し、短絡電流が
流れた状態で電極を逆送することによつて両者を一旦強
制的に引離し、この短絡解消時に発生する微少アークの
成長を待つて電極ワイヤを正送して正常アーク溶接に移
行させるいわゆるリトラクトスタート方法が提案されて
いる。この方法によるときは比較的アークスタートの成
功率は高い。特に最初に短絡を検出するまでは小さな短
絡電流が供給される電源から電力を供給し、この電源か
らの出力電流の有無により電極と被溶接物との接触を検
知する方式のものは、短絡時に過大な短絡電流が流れる
ことがないので電極が被溶接物に溶着してしまう危険性
がなく、比較的好結果が得られるものである。しかし、
この方法によるときも電極ワイヤの先端や被溶接物の表
面に何らかの絶縁物が存在していて、機械的には両者が
接触したにもかかわらず電気的に接触が検出されなかつ
たときの解決策は設けられていなかつた。即ち、電極ワ
イヤの先端や被溶接物の表面にスラグ,ミルスケールあ
るいは錆のような絶縁物があると両者が機械的に接触し
ても電気的接触が検出されないことになる。このために
アークの発生およびワイヤの溶融がない状態で送給し続
けられることになる。この継続する電極ワイヤの送給の
ために電極ワイヤが座屈するか、送給機構にスリツプが
生ずるか、もしこれらのいずれもが起らなければワイヤ
送給力により溶接トーチが反力を受けて溶接装置全体が
転倒したり、破損したりすることになる。しかも炭酸ガ
スアーク溶接やサブアージアーク溶接においては、電極
ワイヤの先端には前回の溶接の終了時にスラグや酸化物
が常に付着しており、かつまた被溶接物の表面にもスラ
グやスパツタあるいは散布されたフラツクスなどの絶縁
物があり、上述のような両者間の絶縁状態は常時発生し
得る状態にある。このために溶接の開始に先立つて電極
ワイヤの先端や被溶接物の表面の点検を省略することが
できず、完全無人化ができなかつた。Conventional technology A method of starting an arc in automatic arc welding using consumable electrode wires is to start feeding at a relatively low speed with a high output for welding applied to the electrode wires, so that the electrode wires come into contact with the workpiece. A high-frequency high voltage is applied between the electrode wire and the work to be welded in addition to the welding power output, in which the tip of the electrode wire is melted and scattered by a large short-circuit current that flows to move to an arc. Then, a method of destroying the insulation of the gap between the two and performing an arc start is used. However, of these, the former has a poor success rate of arc start, especially when using a thick electrode wire such as submerged arc welding or when using a wire such as aluminum that has a small specific resistance and a small resistance heating due to a short-circuit current. Was extremely difficult. In addition, the latter method not only requires strengthening of the dielectric strength of the equipment, but it is unavoidable for its own malfunction due to the mixing of high frequency noise and inductive interference to peripheral equipment, resulting in many practical problems. Therefore, as a remedy for these problems, the electrode wire is fed until it comes into contact with the object to be welded, and by reversely feeding the electrode in the state where a short-circuit current flows, the two are forcibly separated once and the short-circuit is eliminated. A so-called retract start method has been proposed in which the electrode wire is forward-fed and transferred to normal arc welding while waiting for the growth of the generated minute arc. With this method, the success rate of arc start is relatively high. In particular, a system that supplies power from a power supply that supplies a small short-circuit current until the first short-circuit is detected, and that detects the contact between the electrode and the workpiece by the presence or absence of output current from this power supply, Since an excessive short-circuit current does not flow, there is no risk that the electrodes will be welded to the object to be welded, and relatively good results can be obtained. But,
Even when this method is used, there is some kind of insulator on the tip of the electrode wire or on the surface of the object to be welded, and the solution is when no electrical contact is detected despite mechanical contact between the two. Was not provided. That is, if there is an insulator such as slag, mill scale, or rust on the tip of the electrode wire or on the surface of the object to be welded, electrical contact will not be detected even if they are mechanically contacted. For this reason, the feeding is continued without the generation of an arc and the melting of the wire. Due to this continuous feeding of the electrode wire, the electrode wire buckles or slips occur in the feeding mechanism, and if neither of these occurs, the wire feeding force causes the welding torch to receive a reaction force and weld. The entire device will fall or be damaged. Moreover, in carbon dioxide arc welding and sub-aged arc welding, slag and oxides are always attached to the tip of the electrode wire at the end of the previous welding, and slag, spatter or spatter is also spread on the surface of the workpiece. There is an insulator such as a flat disk, and the above-described insulating state between the two is always in a state that can occur. For this reason, the inspection of the tip of the electrode wire and the surface of the object to be welded cannot be omitted prior to the start of welding, and complete unmanned operation was not possible.
発明の目的 本発明は、上記従来装置の欠点を解決するものであつ
て、電極ワイヤの送給時にもし電極と被溶接物との間の
絶縁状態が発生しても、溶接装置に何ら支障を来すこと
なく安全に動作を停止させて、無人運転を行つても溶接
装置が破壊されることがないようにしたものである。An object of the present invention is to solve the above-mentioned drawbacks of the conventional apparatus, and even if an insulating state between the electrode and the object to be welded occurs during the feeding of the electrode wire, the welding apparatus is not hindered. The operation is safely stopped without coming, so that the welding device is not destroyed even if unmanned operation is performed.
発明の要旨 本発明は、電極ワイヤと被溶接物との電気的接触を検出
するワイヤタツチ検出回路を設けるとともにワイヤ送給
量検出器を設けて送給量が所定量に達してもなおワイヤ
タツチが検出されないときには異常と判断する手段を設
けることによつて前述の問題点を解決したものである。SUMMARY OF THE INVENTION The present invention provides a wire touch detection circuit for detecting electrical contact between an electrode wire and an object to be welded, and a wire feed amount detector to detect a wire touch even when the feed amount reaches a predetermined amount. The above-mentioned problems are solved by providing a means for judging that the operation is abnormal when not performed.
実施例 第1図は本発明の装置の実施例を示す接続図であり、同
図(a)は溶接電源およびワイヤ送給電動機の制御部を
示し、同図(b)は同図(a)の制御のためのリレーシ
ーケンス接続図を示す。同図において1は溶接電源であ
り、その出力は出力設定器VR4およびVR5によつて定ま
る。2は消耗電極ワイヤ(以下単にワイヤという)、3
は被溶接物、4はワイヤ送給用電動機であり、5はワイ
ヤ送給用電動機4によつて駆動される送給ロールであ
る。6は電圧検出器であつてワイヤ2と被溶接物3との
間の電圧が一定以上となつたときに閉じる接点信号AVR
を有する、7は電流検出器であり、溶接回路に少量でも
電流が流れると動作する接点信号WCRを有する。8はワ
イヤ送給用電動機4の制御回路であり、設定器VR1ない
しVR3によつて定まる回転速度となるように、また指令
信号がF端子に入力されたときは電動機4をワイヤ2が
被溶接物3に向つて送給される方向(正送方向)に回転
させ、またR端子に入力されたときはワイヤを引き上げ
る方向(逆送方向)に回転させるように速度および回転
方向を制御するものである。CR1ないしCR5はリレーであ
りCR1aないしCR5aはそれぞれこれらのリレーの常開接
点,CR2bないしCR5bは常閉接点を示す。TD1ないしTD3は
遅延動作形のタイマでありTD1aおよびTD3aはタイマTD1
およびTD3の常開接点,TD2bはタイマTD2の常閉接点を示
す。PB1は溶接開始用押ボタンスイツチ,PB2は溶接停止
用押ボタンスイツチ,PB3は接触不良検出をリセツトする
ための押ボタンスイツチである。PLは接触不良を検出し
たときに点灯する表示灯であり、警報のための点滅表
示,ブザーなどに変更することができる。9は交流電
源,Eは直流電源である。また出力設定器VR5はワイヤ2
が被溶接物3に接触したときにワイヤ2を溶融しない程
度の小電流が流れるように出力電圧または出力電流を設
定するものであつて溶接電源1の特性によりその設定対
象が選定される。出力設定器VR4は溶接時の出力を設定
するものであつて、溶接用出力設定器としてはこの他に
溶接終了時に出力を低減させるための設定器なども必要
であるが本発明の要旨とは直接関係はないので説明を簡
単にするために省略してある。また設定器VR1は、溶接
開始時にワイヤ2を低速で被溶接物3に向つて送給する
ときのワイヤ送給速度を設定するものであり、設定器VR
2は溶接時におけるワイヤ送給速度を設定する設定器で
ある。設定器VR3はワイヤ2を実質的には逆送しない程
度の微弱な駆動力を電動機4に与えるための設定器であ
り、他の2つの設定器VR1およびVR2と異なり、電動機4
の発生するトルクを設定するものである。また設定器VR
2は、この微弱な逆転動作の後に溶接電源の出力を高出
力とすると同時にワイヤを実質的に逆送するときの速度
設定器および接触不良を検出したときに逆転してワイヤ
を引き上げるときの速度設定器としても共用されてい
る。Embodiment FIG. 1 is a connection diagram showing an embodiment of the apparatus of the present invention, FIG. 1 (a) shows the control unit of the welding power source and wire feeding / feeding motive, and FIG. 1 (b) is the same figure (a). The relay sequence connection diagram for control of is shown. In the figure, 1 is a welding power source, the output of which is determined by the output setters VR4 and VR5. 2 is a consumable electrode wire (hereinafter simply referred to as wire), 3
Is an object to be welded, 4 is a wire feeding electric motor, and 5 is a feeding roll driven by the wire feeding electric motor 4. 6 is a voltage detector, which is a contact signal AVR that is closed when the voltage between the wire 2 and the work piece 3 exceeds a certain level.
Reference numeral 7 is a current detector having a contact signal WCR which is activated when a small amount of current flows through the welding circuit. Reference numeral 8 denotes a control circuit for the wire feeding electric motor 4 so that the electric motor 4 is welded to the wire 2 when a command signal is input to the F terminal so that the rotational speed is determined by the setters VR1 to VR3. Controlling the speed and rotation direction so that the wire is rotated toward the object 3 (forward direction), and when the wire is input to the R terminal, the wire is pulled up (reverse direction). Is. CR1 to CR5 are relays, CR1a to CR5a are normally open contacts of these relays, and CR2b to CR5b are normally closed contacts. TD1 to TD3 are delay operation type timers, and TD1a and TD3a are timers TD1
And TD3 normally open contact, TD2b shows the timer TD2 normally closed contact. PB1 is a push button switch for starting welding, PB2 is a push button switch for stopping welding, and PB3 is a push button switch for resetting contact failure detection. PL is an indicator light that lights up when a contact failure is detected, and can be changed to a blinking display for alarms or a buzzer. 9 is an AC power supply and E is a DC power supply. Also, the output setting device VR5 is wire 2
Is to set the output voltage or output current so that a small current that does not melt the wire 2 when it contacts the object to be welded 3 is selected, and the setting target is selected according to the characteristics of the welding power source 1. The output setter VR4 sets the output at the time of welding, and as the welding output setter, a setter for reducing the output at the end of welding is also required, but the gist of the present invention is It is omitted for the sake of simplicity because it is not directly related. The setting device VR1 sets the wire feeding speed when the wire 2 is fed at a low speed toward the workpiece 3 at the start of welding.
2 is a setting device for setting the wire feeding speed during welding. The setting device VR3 is a setting device for giving a weak driving force to the electric motor 4 that does not substantially feed the wire 2 backward, and unlike the other two setting devices VR1 and VR2, the electric motor 4 is set.
The torque that is generated is set. Also the setting device VR
2 is the speed setter when the output of the welding power source is made high after this weak reversing operation and at the same time the wire is substantially fed backward, and the speed at which the wire is reversed to pull up the wire when contact failure is detected. It is also used as a setter.
同図の実施例において、溶接開始用押ボタンスイツチPB
1を押すとリレーCR1が励磁される。リレーCR1の励磁に
より常開接点CR1aが閉じて出力設定器VR5および設定器V
R1がそれぞれ溶接電源1および電動機制御回路8に接続
される。この結果ワイヤ2と被溶接物3との間には小さ
な短絡電流が流れ得る出力が供給される。また電動機4
は設定器VR1にて定まる比較的低速で回転し、ワイヤ2
はゆつくりと被溶接物3に向つて送給される。ワイヤ2
が被溶接物3に接触したときに絶縁物の介在がないと短
絡電流が流れ、この短絡電流は電流検出器7によつて検
出されて出力接点WCRが動作する。この接点WCRの動作に
よつてリレーCR2が励磁され、このリレーCR2の常閉接点
CR2bによつて設定器VR1は切離され、常開接点CR2aによ
つて設定器VR3が電動機制御回路8のR端子に接続され
る。このために電動機4は正転を中止し、設定器VR3の
設定値に応じて逆転しワイヤ2を引上げる方向に回転す
ることになる。しかし設定器VR3の設定値は前述のよう
に微弱な駆動力を与える程度の値に設定されているので
電動機4はこれに結合されている減速機構のバツクラツ
シユやワイヤ2が始めの正送時に惰性によつて被溶接物
3に押しつけられている力を解消するまでの極く軽い負
荷状態の間のみ逆転し、実際にワイヤが逆送されるとき
には大きな駆動力が必要となるので電動機4はそれ以上
回転せず、ワイヤは実質的には引き上げられず被溶接物
に極く軽く接触した状態を保つことになる。一方リレー
CR2の常開接点CR2aはまたタイマTD3も励磁するので電動
機4の逆転指令と同時にタイマTD3も時限を開始する。
タイマTD3の時限終了により接点TD3aが閉じるとリレーC
R4が励磁され、このリレーCR4の接点CR4aおよびCR4bに
より出力設定器がVR5からVR4に切替えられるとともに電
動機制御回路8の設定器もVR3からVR2に切替えられる。
この結果、溶接電源1の出力は溶接に必要な高出力とな
り、かつワイヤ2の送給速度も設定器VR2にて定まる高
速となつて急速に引き上げられることになる。この逆送
によつてワイヤ2と被溶接物3との接触が解消され、こ
のときに供給されている溶接電源1の高出力によつてア
ークが発生する。このときワイヤ2と被溶接物3とは先
の弱い逆転駆動によつて両者の接触圧力がほとんど零に
なつており、しかも送給機構のバツクラツシユ分もなく
なつているので供給電力の切替えに対してワイヤの引き
上げ動作の遅れが極めて少なく、容易にワイヤ2の先端
部分が溶融しアークに移行する。この状態で逆送が続く
とアークは成長し、このときのアーク電圧が電圧検出器
6の設定電圧より高くなるとその接点AVRが閉じる。こ
の結果リレーCR5が励磁されてその接点CR5a,CR5bによつ
て電動機制御回路8の入力はRからFに切替えられる。
この結果電動機4の回転方向は反転し、ワイヤ2を設定
器VR2にて定まる速度にて正送し、正常溶接が開始され
る。In the embodiment shown in the figure, the welding start pushbutton switch PB
When 1 is pressed, relay CR1 is excited. The normally open contact CR1a closes due to the excitation of the relay CR1, and the output setter VR5 and setter V
R1 is connected to the welding power source 1 and the motor control circuit 8, respectively. As a result, an output capable of flowing a small short-circuit current is supplied between the wire 2 and the workpiece 3. Also electric motor 4
Rotates at a relatively low speed determined by the setting device VR1, and the wire 2
Is fed toward the work piece 3 to be welded. Wire 2
A short-circuit current flows when there is no insulator interposed when it contacts the object 3 to be welded. This short-circuit current is detected by the current detector 7 and the output contact WCR operates. Relay CR2 is excited by the operation of this contact WCR, and the normally closed contact of this relay CR2
The setter VR1 is disconnected by CR2b, and the setter VR3 is connected to the R terminal of the motor control circuit 8 by the normally open contact CR2a. For this reason, the electric motor 4 stops normal rotation, rotates in reverse according to the set value of the setting device VR3, and rotates in the direction of pulling up the wire 2. However, since the setting value of the setting device VR3 is set to a value that gives a weak driving force as described above, the electric motor 4 is inertial at the time of forward feeding of the backlash and the wire 2 of the reduction mechanism connected to the electric motor 4. Therefore, the reverse rotation is performed only during a very light load state until the force pressed against the workpiece 3 is canceled, and when the wire is actually fed back, a large driving force is required, so the electric motor 4 The wire does not rotate more than the above, and the wire is not substantially pulled up, and the wire is kept in very light contact with the object to be welded. Meanwhile relay
Since the normally open contact CR2a of CR2 also excites the timer TD3, the timer TD3 also starts the time limit at the same time as the reverse rotation command of the electric motor 4.
Relay C when contact TD3a is closed due to the expiration of timer TD3
R4 is excited, and the contacts CR4a and CR4b of the relay CR4 switch the output setter from VR5 to VR4 and also the setter of the motor control circuit 8 from VR3 to VR2.
As a result, the output of the welding power source 1 becomes a high output required for welding, and the feeding speed of the wire 2 is rapidly increased to the high speed determined by the setting device VR2. By this back feeding, the contact between the wire 2 and the work piece 3 is eliminated, and an arc is generated by the high output of the welding power source 1 supplied at this time. At this time, the contact pressure between the wire 2 and the object to be welded 3 is almost zero due to the weak reverse drive, and since there is no backlash in the feeding mechanism, the supply power is not changed. The delay of the wire pulling operation is extremely small, and the tip portion of the wire 2 is easily melted and transferred to the arc. The arc grows when the reverse feed continues in this state, and when the arc voltage at this time becomes higher than the set voltage of the voltage detector 6, the contact AVR is closed. As a result, the relay CR5 is excited, and the input of the motor control circuit 8 is switched from R to F by the contacts CR5a and CR5b.
As a result, the rotating direction of the electric motor 4 is reversed, the wire 2 is forwardly fed at a speed determined by the setting device VR2, and normal welding is started.
第1図の実施例の装置は、正常時においては上記のよう
に動作するが、もし最初の低速ワイヤ送給時にワイヤ2
と被溶接物3との間が何らかの原因で絶縁状態にある
と、ワイヤが被溶接物に機械的に接触しても短絡電流は
流れ得ないから電流検出器7の接点WCRは動作しないこ
とになる。このためワイヤはさらに送給され続けること
になるが、溶接開始押ボタンスイツチの閉路と同時に励
磁されたタイマTD1の時限終了によつて接点TD1aが閉じ
るとリレーCR3が励磁され、リレーCR3は自身の常開接点
CR3aによつて自己保持される。またこれと同時に接点CR
3bによつて電動機制御回路のF端子に対する入力信号は
遮断され電動機4はワイヤを正送することを停止する。
リレーCR3と並列に接続された表示灯PLによつてワイヤ
接触不良の警告を表示する。さらにタイマTD2の時限終
了までの間電動機制御回路8にはリレー接点CR3aを通し
てR端子に設定器VR2の出力が供給されて電動機4が高
速逆転し、ワイヤ2を引き上げる。一度ワイヤ接触不良
が検出されるとリレーCR3が自己保持されるので、リセ
ツト押ボタンスイツチPB3を押すまでは他の動作が行な
えない。そこで作業者がワイヤ先端や被溶接物の表面状
態を点検し修正した後にリセツト押ボタンスイツチPB3
を押して後に再び溶接開始押ボタンスイツチPB1を押し
て再起動することになる。上記の動作から容易に判るよ
うにタイマTD1の時限はワイヤ送給開始から接触に至る
までの時間より若干長い程度(通常0.3ないし3秒程
度)とし、タイマTD2の時限は、接触状態にあるワイヤ
を略もとの位置まで復帰させるのに必要な時間(通常0.
1ないし1秒程度)とし、またタイマTD3は送給機構のバ
ツクラツシユを解消するのに必要な時間より長ければよ
く厳密なものは必要ではないので0.5秒ないし数秒に設
定すればよい。これらのタイマはそれぞれ必要なワイヤ
送給量またはワイヤ送給機構の駆動量を得るためのもの
であり、それぞれの設定は、対応するワイヤ送給速度に
よつてその時限を変更することが必要である。これらの
タイマのかわりにワイヤの送給機構の回転数や送給速度
と送給時間との積により実際のワイヤ送給量を得てプリ
セツト値と比較するように構成すればさらに正確な制御
が可能となる。The apparatus of the embodiment shown in FIG. 1 operates as described above in the normal state, but if the wire 2 is fed at the first low speed wire feeding,
If the wire and the work piece 3 are insulated from each other for some reason, the contact WCR of the current detector 7 does not work because the short-circuit current cannot flow even if the wire mechanically contacts the work piece. Become. For this reason, the wire will continue to be fed, but when the contact TD1a closes due to the end of the timer TD1 that was excited at the same time as the closing of the welding start pushbutton switch, relay CR3 is excited and relay CR3 Normally open contact
Self-held by CR3a. At the same time, contact CR
The input signal to the F terminal of the electric motor control circuit is cut off by 3b, and the electric motor 4 stops the forward feeding of the wire.
An indicator PL connected in parallel with the relay CR3 displays a warning of poor wire contact. Further, the output of the setting device VR2 is supplied to the R terminal through the relay contact CR3a to the electric motor control circuit 8 until the time limit of the timer TD2 ends, the electric motor 4 reverses at high speed, and the wire 2 is pulled up. Once a poor wire contact is detected, the relay CR3 is held by itself, and other operations cannot be performed until the reset pushbutton switch PB3 is pressed. Therefore, after the operator inspects and corrects the wire tip and the surface condition of the work piece, the reset push button switch PB3
After pressing, the welding start push button switch PB1 will be pressed again to restart. As can be easily understood from the above operation, the time period of the timer TD1 is set to be slightly longer than the time from the wire feeding start to the contact (usually about 0.3 to 3 seconds), and the time period of the timer TD2 is set to the wire in the contact state. The time required to return the to approximately the original position (usually 0.
The timer TD3 may be set to 0.5 seconds to several seconds, as long as it is longer than the time required to eliminate the backlash of the feeding mechanism, and a strict timer is not necessary. These timers are respectively for obtaining the required wire feeding amount or the driving amount of the wire feeding mechanism, and their respective settings require changing the time period according to the corresponding wire feeding speed. is there. Instead of these timers, if the actual wire feeding amount is obtained by comparing the number of rotations of the wire feeding mechanism and the feeding speed with the feeding time, and it is compared with the preset value, more accurate control is possible. It will be possible.
なお第1図の実施例においては、タイマTD2を設けてワ
イヤ接触不良を検知したときは自動的にワイヤを一定時
間だけ引き上げるようにしたが、このタイマTD2を設け
ないときにはワイヤ接触不良を検知したときにはワイヤ
送給機構が直ちに停止して検出時の状態を保つことにな
る。したがつてワイヤ接触不良の原因が判別しやすくな
り、作業者が溶接部を容易に視認できるときにはタイマ
TD2を除いて自動引上げを行なわせない方がよい場合も
ある。この場合には、作業者が手動操作により図示を省
略した押ボタンスイツチにより適宜ワイヤを逆転させれ
ばよい。またワイヤ送給,逆送,速度変更,溶接電源の
出力切替えなどのタイミングは任意であり、また各動作
の間に適宜一旦停止および確認再起動指令や一旦停止後
自動再起動などの工程を追加してもよく、さらにこれら
の各動作に連動してシールドガスの放出、フラツクスの
撒布、溶接トーチの移動など溶接に必要な他の動作を行
なわせるようにしてもよい。In the embodiment shown in FIG. 1, when the timer TD2 is provided and the wire contact failure is detected, the wire is automatically pulled up for a predetermined time. However, when the timer TD2 is not provided, the wire contact failure is detected. At times, the wire feeding mechanism stops immediately and maintains the state at the time of detection. Therefore, it becomes easier to determine the cause of poor wire contact, and when the operator can easily see the weld, the timer
In some cases, it may be better not to perform automatic pulling except for TD2. In this case, the operator may manually reverse the wire by a push button switch (not shown) by manual operation. In addition, the timing of wire feeding, reverse feeding, speed change, output switching of welding power source, etc. is arbitrary, and processes such as temporary stop and confirmation restart command and automatic restart after temporary stop are added during each operation. Alternatively, other operations necessary for welding such as release of shield gas, sprinkling of flux, and movement of welding torch may be performed in conjunction with these operations.
また第1図の実施例においては、ワイヤ接触不良が検出
されると直ちにアークスタート動作を中断するものにつ
いて示したが、ワイヤと被溶接物との間の絶縁状態は比
較的軽微な衝撃によつて破壊される絶縁物による場合が
多い。そこでワイヤ接触不良が検出されたときにも直ち
にアークスタート動作を中断するのではなく、一旦ワイ
ヤを引き上げて後に再度アークスタート動作を始めから
やりなおせば再度のワイヤ接触時の衝撃で絶縁状態が解
消して良好なアークスタートが行なわれる可能性があ
る。本発明の第2の発明は、ワイヤ接触不良が検出され
たときにくりかえしアークスタート動作をするくりかえ
し回路を設けた装置を提案したものである。第2図にそ
の実施例の接続図を示す。同図の装置は第1図に示した
実施例にワイヤ接触不良の発生回数を計数するプリセツ
トカウンタCU1とこのプリセツトカウンタの計数値がプ
リセツト値に達したときに励磁されるリレーCR6とを追
加し、またリレーCR3とタイマTD2の自己保持回路を除く
とともにタイマTD1の励磁をタイマTD2の常閉接点により
遮断するようにして、ワイヤ接触不良検出後のワイヤ逆
送時間の後に再びアークスタート動作を始めから行うよ
うにしたくりかえし回路を設けたものである。In the embodiment shown in FIG. 1, the arc start operation is interrupted as soon as the wire contact failure is detected. However, the insulation state between the wire and the workpiece is not affected by a relatively slight impact. In many cases, this is due to the insulator being destroyed. Therefore, when a wire contact failure is detected, the arc start operation is not immediately interrupted, but if the wire is pulled up and the arc start operation is restarted from the beginning, the insulation state will be canceled by the impact of the wire contact again. And good arc start may be performed. A second invention of the present invention proposes a device provided with a repeating circuit for repeating an arc start operation when a defective wire contact is detected. FIG. 2 shows a connection diagram of the embodiment. The apparatus shown in FIG. 1 has a preset counter CU1 which counts the number of occurrences of wire contact failure and a relay CR6 which is excited when the count value of the preset counter reaches the preset value in the embodiment shown in FIG. In addition, the relay CR3 and the self-holding circuit of timer TD2 are removed, and the excitation of timer TD1 is interrupted by the normally closed contact of timer TD2. It is provided with a repetitive circuit that is designed to be performed from the beginning.
同図の実施例の動作のうち、ワイヤ接触が正常に行なわ
れたときの動作は第1図に示した実施例と全く同じであ
るので説明は省略し、ワイヤ接触不良が検出されたとき
の動作について説明する。押ボタンスイツチPB1が押さ
れてリレーCR1が励磁され、ワイヤ2が設定器VR1によつ
て定まる低速度で被溶接物3に向つて送給されたとき
に、タイマTD1の時限終了時に至つても未だ電流検出器
7が何らの電流も検出せず接点WCRが動作していなけれ
ばワイヤ接触不良としてリレーCR3およびタイマTD2が励
磁される。この結果制御回路8の入力はF端子からR端
子に切替えられるとともに設定器もVR1からVR2に切替え
られて、ワイヤ2は設定器VR2で定まる速度で引き上げ
られる。タイマTD2の時限終了により常閉接点TD2bが開
路するとタイマTD1は非励磁となりその常開接点TD1aは
直ちに開放されてリレーCR3,タイマTD2が非励磁とな
る。このためタイマTD2の常閉接点は復帰しタイマTD1が
再び励磁されて押ボタンスイツチPB1が押された最初の
状態に戻る。このときリレーCR3の復帰によつて制御回
路8の入力は再びF端子に設定器VR1の出力が供給され
て低速度の正送給となる。この再度の正送給によつてタ
イマTD1の時限内に電流検出器8の接点WCRが動作しなけ
れば再度リレーCR3およびタイマTD2が励磁されてワイヤ
2の引上げおよび再送給がくりかえされることになる。
このときリレーCR3が励磁される毎に接点CR3aによつて
プリセツトカウンターCU1は計数を行い、この計数値が
プリセツト数に一致したときに出力端子に接続されてい
るリレーCR6が励磁されてリレーCR1を非励磁とし以後の
動作を中断する。In the operation of the embodiment shown in FIG. 10, the operation when the wire contact is normally made is exactly the same as that of the embodiment shown in FIG. The operation will be described. When the pushbutton switch PB1 is pressed to excite the relay CR1 and the wire 2 is fed toward the workpiece 3 at the low speed determined by the setter VR1, even if the time limit of the timer TD1 is reached. If the current detector 7 still does not detect any current and the contact WCR is not operating, the relay CR3 and the timer TD2 are excited because of the wire contact failure. As a result, the input of the control circuit 8 is switched from the F terminal to the R terminal and the setting device is also changed from VR1 to VR2, and the wire 2 is pulled up at a speed determined by the setting device VR2. When the normally closed contact TD2b opens due to the end of the timer TD2, the timer TD1 is de-energized and the normally open contact TD1a is immediately opened to deactivate the relay CR3 and the timer TD2. Therefore, the normally closed contact of the timer TD2 is restored, the timer TD1 is excited again, and the state returns to the initial state in which the push button switch PB1 is pushed. At this time, due to the return of the relay CR3, the input of the control circuit 8 is again supplied with the output of the setting device VR1 to the F terminal, and the low speed normal feeding is performed. If the contact WCR of the current detector 8 does not operate within the time limit of the timer TD1 due to this re-forward feed, the relay CR3 and the timer TD2 are excited again and the pulling up and re-feeding of the wire 2 are repeated. .
At this time, each time the relay CR3 is excited, the preset counter CU1 counts by the contact CR3a, and when this count value matches the preset number, the relay CR6 connected to the output terminal is excited and the relay CR1 Is de-energized and the subsequent operation is interrupted.
第2図に示した実施例は、上記のように動作するのでワ
イヤ接触不良が検出されても自動的にワイヤを引き上げ
てアークスタート動作を所定の回数くりかえすので、ワ
イヤの先端にスラグが附着している場合のように絶縁状
態が比較的脆弱な場合には溶接を中断することなくアー
クスタートが行なわれることになる。またこの絶縁状態
が強固な絶縁物に基因する場合には所定の回数の試行の
後に停止するので、過度のくりかえしを防止することが
できワイヤの先端を変形させたりワイヤ送給機構を過負
荷にする危険性がない。Since the embodiment shown in FIG. 2 operates as described above, even if a wire contact failure is detected, the wire is automatically pulled up and the arc start operation is repeated a predetermined number of times, so that a slug is attached to the tip of the wire. In the case where the insulation state is relatively weak, as in the case described above, the arc start is performed without interrupting the welding. Also, if this insulation state is due to a strong insulator, it stops after a predetermined number of trials, so excessive repetition can be prevented, the tip of the wire can be deformed, and the wire feeding mechanism can be overloaded. There is no risk to
なお上記各実施例においてワイヤ送給時に接触検出の時
点でワイヤを被溶接物の表面に平行に若干巾で揺動させ
るようにすればさらに効果的である。特に本発明をテイ
ーチングプレイバツク方式のアーク溶接ロボツトに適用
するときには溶接トーチの動く経路を任意に教示できる
ので最適の揺動軌跡を描かせることができるので本発明
の効果がより有効に発揮できるものである。In each of the above-described embodiments, it is more effective to swing the wire parallel to the surface of the object to be welded with a slight width at the time of contact detection during wire feeding. In particular, when the present invention is applied to the arc welding robot of the teaching play back system, the movement path of the welding torch can be arbitrarily taught, so that the optimum swing locus can be drawn and the effect of the present invention can be more effectively exhibited. Is.
さらに本発明の装置は、図示のような有接点リレーによ
り構成するものに限らず、半導体集積回路などを利用し
た論理回路により構成することも可能である。Further, the device of the present invention is not limited to the one having a contact relay as shown in the drawing, but may be a logic circuit using a semiconductor integrated circuit or the like.
発明の効果 以上のように本発明においては、ワイヤを一旦被溶接物
に接触させた後に強制的に引きあげてアークを発生させ
るリトラクトスタート方式を行う消耗電極式アーク溶接
装置において、ワイヤを所定量送給したにもかかわらず
接触が検知されなかったときには接触不良と判断する判
定回路を設けたので、従来装置のようにワイヤの先端や
被溶接物の表面にスラグや錆あるいはフラツクスのよう
な絶縁物が存在したときにも接触検出のための工程とし
てのワイヤを送給し続けることがなくなり、ワイヤの座
屈や溶接装置の転倒あるいは破損などの発生を未然に防
止することができ、溶接部の視認が困難な狭い場所での
溶接が安全に行えるものであり、アークスタート時の事
故が防止できることから完全無人化が可能となるもので
ある。As described above, in the present invention, in the consumable electrode type arc welding apparatus that performs the retract start method in which the wire is once brought into contact with the object to be welded and then forcibly pulled up to generate the arc, the wire is fed by a predetermined amount. Since a judgment circuit is provided to judge contact failure when no contact is detected despite the fact that the wire is supplied, the tip of the wire and the surface of the work to be welded, such as with conventional equipment, are made of an insulating material such as slag, rust, or flux. Even if there is a wire, it is no longer necessary to continue feeding the wire as a process for contact detection, and it is possible to prevent the occurrence of wire buckling and tipping or damage of the welding equipment. Welding can be performed safely in a narrow space where it is difficult to see, and accidents at the start of an arc can be prevented, so complete unmanned operation is possible.
第1図(a)および(b)は本発明の装置の実施例を示
す接続図、第2図(a)および(b)は本発明の別の実
施例を示す接続図である。 1……溶接電源、2……ワイヤ、3……被溶接物、4…
…電動機、6……電圧検出器、7……電流検出器、8…
…電動機制御回路、CU1……プリセツトカウンタ1 (a) and 1 (b) are connection diagrams showing an embodiment of the device of the present invention, and FIGS. 2 (a) and 2 (b) are connection diagrams showing another embodiment of the present invention. 1 ... Welding power source, 2 ... Wire, 3 ... Workpiece, 4 ...
... motor, 6 ... voltage detector, 7 ... current detector, 8 ...
… Motor control circuit, CU1 …… Preset counter
Claims (12)
接触を検出するワイヤタッチ検出回路と、溶接開始指令
から前記消耗電極ワイヤが所定量送給されたことを検出
して信号を出力する送給量検出手段と、溶接開始に際し
て前記送給量検出手段の出力のみが出力され前記ワイヤ
タッチ検出回路の電極ワイヤと被溶接物との接触検出信
号が出力されないときにワイヤ接触不良と判断する判定
回路とを備えた消耗電極式アーク溶接装置。1. A wire touch detection circuit for detecting electrical contact between a consumable electrode wire and an object to be welded, and a signal for detecting that a predetermined amount of the consumable electrode wire has been fed from a welding start command. The feed amount detecting means for outputting and the wire contact failure when only the output of the feed amount detecting means is outputted at the time of welding start and the contact detection signal between the electrode wire of the wire touch detecting circuit and the workpiece is not outputted. Consumable electrode type arc welding device with a judgment circuit for judging.
給開始からの送給長さをワイヤの送給時間、ワイヤ送給
機構の回転数またはワイヤ送給速度と送給時間との積の
いずれかにより検出する手段である特許請求の範囲第1
項に記載の消耗電極式アーク溶接装置。2. The wire feed amount detecting means determines the feed length from the start of wire feed as the wire feed time, the rotation speed of the wire feed mechanism or the wire feed speed and feed time. Claim 1 which is means for detecting by any of the products
The consumable electrode type arc welding apparatus as described in the paragraph.
極ワイヤと被溶接物との電気的接触を検出した後は前記
消耗電極ワイヤを一旦引き上げてアークを発生させるた
めのワイヤ逆送指令信号を出力する回路である特許請求
の範囲第1項に記載の消耗電極式アーク溶接装置。3. The wire touch detection circuit, after detecting the electrical contact between the consumable electrode wire and the object to be welded, pulls up the consumable electrode wire once to generate a wire back-feed command signal for generating an arc. The consumable electrode type arc welding device according to claim 1, which is an output circuit.
極ワイヤと被溶接物との間に前記消耗電極ワイヤを溶融
しない程度の小さな短絡電流を流す電力を溶接電源の出
力を調整することによって供給し、前記消耗電極ワイヤ
と被溶接物との接触を短絡電流の流通により検出する回
路である特許請求の範囲第1項に記載の消耗電極式アー
ク溶接機。4. The wire touch detection circuit supplies electric power for flowing a small short-circuit current between the consumable electrode wire and an object to be welded so as not to melt the consumable electrode wire by adjusting an output of a welding power source. The consumable electrode type arc welder according to claim 1, which is a circuit for detecting contact between the consumable electrode wire and the object to be welded by circulating a short-circuit current.
ワイヤを実質的には逆送しない程度の逆送動作を一定時
間ワイヤ送給機構に作用させる第1の指令信号と、前記
第1の指令信号の終了の後に前記消耗電極ワイヤを一定
時間実質的に逆送させる第2の指令信号とからなる信号
である特許請求の範囲第3項に記載の消耗電極式アーク
溶接装置。5. The wire back-feeding command signal includes a first command signal that causes a wire feeding mechanism to perform a back-feeding operation that does not substantially feed back the consumable electrode wire for a certain period of time; 4. The consumable electrode type arc welding device according to claim 3, which is a signal including a second command signal that causes the consumable electrode wire to be substantially back-fed for a certain period of time after the end of the command signal of.
に供給される電力は、前記第2の指令信号が供給される
までは前記消耗電極ワイヤを溶融しない程度の小さな短
絡電流を流す電力であり、前記第2の指令信号が供給さ
れた後はアーク溶接に適した値の電力に切替えられるも
のである特許請求の範囲第5項に記載の消耗電極式アー
ク溶接装置。6. The electric power supplied between the consumable electrode wire and the object to be welded is such a short circuit current that does not melt the consumable electrode wire until the second command signal is supplied. The consumable electrode type arc welding device according to claim 5, which is electric power and is switched to electric power having a value suitable for arc welding after the second command signal is supplied.
接触を検出するワイヤタッチ検出回路と、溶接開始指令
から前記消耗電極ワイヤが所定量送給されたことを検出
して信号を出力する送給量検出手段と、溶接開始に際し
て前記送給量検出手段の出力のみが出力され前記ワイヤ
タッチ検出回路の電極ワイヤと被溶接物との接触検出信
号が出力されないときにワイヤ接触不良と判断する判定
回路と、前記判定回路の接触不良出力により前記送給量
検出手段をリセットするとともに前記消耗電極ワイヤを
所定量逆送し逆送後に再度正送を行うくりかえし回路と
を備えた消耗電極式アーク溶接装置。7. A wire touch detection circuit for detecting electrical contact between a consumable electrode wire and an object to be welded, and a signal for detecting that a predetermined amount of the consumable electrode wire has been fed from a welding start command. The feed amount detecting means for outputting and the wire contact failure when only the output of the feed amount detecting means is outputted at the time of welding start and the contact detection signal between the electrode wire of the wire touch detecting circuit and the workpiece is not outputted. A consumable electrode having a judging circuit for judging, and a repeating circuit for resetting the feed amount detecting means by a contact failure output of the judging circuit and for feeding back the consumable electrode wire by a predetermined amount and then forward-feeding again. Type arc welding equipment.
れた回数だけアークスタート動作をくりかえしてもなお
ワイヤ接触不良が検出されたときには、アークスタート
動作を停止する回路である特許請求の範囲第3項に記載
の消耗電極式アーク溶接装置。8. The circuit according to claim 3, wherein the repeating circuit is a circuit for stopping the arc starting operation when a defective wire contact is still detected even after repeating the arc starting operation a predetermined number of times. The consumable electrode type arc welding device described.
極ワイヤと被溶接物との電気的接触を検出した後は前記
消耗電極ワイヤを一旦引き上げてアークを発生させるた
めのワイヤ逆送指令信号を出力する回路である特許請求
の範囲第7項または第8項のいずれかに記載の消耗電極
式アーク溶接装置。9. The wire touch detection circuit, after detecting the electrical contact between the consumable electrode wire and the object to be welded, temporarily pulls up the consumable electrode wire to generate a wire reverse feed command signal for generating an arc. The consumable electrode type arc welding device according to claim 7 or 8, which is an output circuit.
電極ワイヤと被溶接物との間に前記消耗電極ワイヤを溶
融しない程度の小さな短絡電流を流す電力を溶接電源の
出力を調整することによって供給し、前記消耗電極ワイ
ヤと被溶接物との接触を短絡電流の流通により検出する
回路である特許請求の範囲第7項または第8項のいずれ
かに記載の消耗電極式アーク溶接機。10. The wire touch detection circuit supplies electric power for flowing a small short-circuit current between the consumable electrode wire and an object to be welded so as not to melt the consumable electrode wire by adjusting an output of a welding power source. The consumable electrode type arc welder according to claim 7, which is a circuit for detecting contact between the consumable electrode wire and the object to be welded by flowing a short-circuit current.
極ワイヤを実質的には逆送しない程度の逆送動作を一定
時間ワイヤ送給機構に作用させる第1の指令信号と、前
記第1の指令信号の終了の後に前記消耗電極ワイヤを一
定時間実質的に逆送させる第2の指令信号とからなる信
号である特許請求の範囲第9項に記載の消耗電極式アー
ク溶接装置。11. The wire back-feeding command signal includes a first command signal that causes a wire feeding mechanism to perform a back-feeding operation that does not substantially feed back the consumable electrode wire for a certain period of time. 10. The consumable electrode type arc welding device according to claim 9, which is a signal including a second command signal that causes the consumable electrode wire to be substantially back-fed for a certain period of time after the end of the command signal.
間に供給される電力は、前記第2の指令信号が供給され
るまでは前記消耗電極ワイヤを溶融しない程度の小さな
短絡電流を流す電力であり、前記第2の指令信号の供給
と略同時にアーク溶接に適した値の電力に切替えられる
ものである特許請求の範囲第11項に記載の消耗電極式ア
ーク溶接装置。12. The electric power supplied between the consumable electrode wire and the object to be welded is such a short circuit current that does not melt the consumable electrode wire until the second command signal is supplied. 12. The consumable electrode type arc welding apparatus according to claim 11, which is electric power and is switched to electric power of a value suitable for arc welding substantially at the same time as the supply of the second command signal.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP13609084A JPH0671658B2 (en) | 1984-06-29 | 1984-06-29 | Consumable electrode arc welding equipment |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP13609084A JPH0671658B2 (en) | 1984-06-29 | 1984-06-29 | Consumable electrode arc welding equipment |
Publications (2)
Publication Number | Publication Date |
---|---|
JPS6114080A JPS6114080A (en) | 1986-01-22 |
JPH0671658B2 true JPH0671658B2 (en) | 1994-09-14 |
Family
ID=15167021
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP13609084A Expired - Lifetime JPH0671658B2 (en) | 1984-06-29 | 1984-06-29 | Consumable electrode arc welding equipment |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH0671658B2 (en) |
Families Citing this family (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP4490011B2 (en) * | 2001-11-13 | 2010-06-23 | 株式会社ダイヘン | Arc start control method |
JP2008200693A (en) * | 2007-02-19 | 2008-09-04 | Daihen Corp | Arc start control method for robot arc welding |
JP2007216303A (en) * | 2007-06-05 | 2007-08-30 | Daihen Corp | Arc start control method |
CN101842183B (en) * | 2007-12-03 | 2013-01-09 | 株式会社大亨 | Arc start control method |
-
1984
- 1984-06-29 JP JP13609084A patent/JPH0671658B2/en not_active Expired - Lifetime
Also Published As
Publication number | Publication date |
---|---|
JPS6114080A (en) | 1986-01-22 |
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