SE187257C1

SE187257C1 -

Info

Publication number: SE187257C1
Authority: SE
Publication date: 1963-01-01

Description

Uppfinnare: R R Lobosco Prioritet begard fron den 4 april 1956 (USA) Foreliggande uppfinning hanfor sig till elektrisk bagsvetsning och sarskilt till svetsning med ett flertal elektroder. Inventor: R R Lobosco Priority applied from April 4, 1956 (USA) The present invention relates to electric back welding and in particular to welding with a plurality of electrodes.

Vid svetsning med en enda elektrod observeras det ofta, att svetsintrangningen vid borjan av svetsstrfingen ej är sâ kraftig sasom pd. nagot avstand darifran langs strangen. Denna effekt, som beror pa varmeokning i platen, är icke onskvard, dâ en likformig intrangning langs svetsens hela langd är nOclvandig, sarskilt vid hog svetshastighet Vanliga medal for all betvinga detta problem är att starta svetsstrangen pa skrotmaterial, sâ att svetsstrangens borjan, som uppvisar dalig intrangning, ,kan bli bortskuren. Fars& att sakerstalla fullstandig intrangning vid starten genom att fiirdroja framforningen resulterar vanligen i genombranningar eller i overskottspalaggning av svetsmetall vid star-ten. When welding with a single electrode, it is often observed that the welding intrusion at the beginning of the welding process is not as strong as at present. some distance from there along the string. This effect, which is due to heat increase in the plate, is not negligible, as a uniform penetration along the entire length of the weld is normal, especially at high welding speeds. Common medals for all this problem are to start the welding strand on scrap material, so that the weld strand starts daily intrusion,, can be cut off. Fars & to ensure complete penetration at the start by delaying the advance usually results in burns or in excess application of weld metal at the start.

Det är kfint att dylika icke Onskade effekter kunna elimineras, dä enkla elektroder anvandas, genom att mata from elektroden till arbetsstycket vid en hastighet som är olika hastigheten vid svetsning, vanligen vid en lagre hastighet. Nar &Aden her& arbetsstycket for att tanda ljusbagen, andras tradmatningen till den onskade svetshastigheten. Resultaten bliva: (1). Den mycket lagre startOvergangen fordrar icke en kraftledning med exceptionellt god reglering vid hoga overgaende stromstyrkor. (2). Ljusbagen stabiliseras snabbt och resulterar i en pun start. (3). Det är mycket mindre sannolikhet for genonasmaltning vid tunna sektioner. (4). Ljusbagsstarten Or foljdriktig. It is possible that such undesirable effects can be eliminated, when simple electrodes are used, by feeding from the electrode to the workpiece at a speed which is different from the speed of welding, usually at a lower speed. When & Aden her & the workpiece to light the candle bag, others wire feed to the desired welding speed. The results are: (1). The much lower starting transition does not require a power line with exceptionally good regulation at high transient currents. (2). The candle bag stabilizes quickly and results in a pun start. (3). Genonase melting is much less likely in thin sections. (4). Light bag start Or sequential.

FOr svetsning vid mycket la.ga stromstyrkor Or det ibland fordelaktigt att starta den enkla ljusbagen. vid en nagot hogre stromstyrka an den onskade stromstyrkan under Dupl. kl. 21 h: 30/ svetsningen och sedan minska den till den Onskade svetsstromstyrkan. Detta kan ernds genom att starta vid en hogre tradhastighet och sedan automatiskt minska tradmatningen till den onskade svetshastigheten efter det att ljusbagen tants. For welding at very low currents Is it sometimes advantageous to start the simple light bag. at a slightly higher current than the desired current during Dupl. at 21 h: 30 / welding and then reduce it to the desired welding current. This can be achieved by starting at a higher wire speed and then automatically reducing the wire feed to the desired welding speed after the candle bag is tanned.

Matning av traden mot arbetsstycket vid en hastighet, som Or ldmplig for palitlig start och darefter andring av tradmatningshastigheten till det onskade vardet fOr svetsning Or med fordel utforbart med kraftkallor, som hava en vasentligen flack volt-amperekarakteristik. Denna procedur Or sarskilt effektiv vid ljusbagspunktsvetsning, dar bagliden Or relativt kort och en kivck, palitlig start Or vasentlig. A andra sidan lava tillfredsstallande resultat aven uppnatts med kraftkallor, som lava en volt-amperekarakteristik, Aiken fOreter en initial sankning fOljd av en stigning i svetsomradet. En karakteristik av detta slag uppnas med exempelvis en kraftkalla av transformatortyp, som har en mattbar reaktortypregiering. Feeding the wire against the workpiece at a speed which is suitable for reliable starting and then changing the wire feed speed to the desired value for welding is advantageously practicable with power sources which have a substantially flat volt-ampere characteristic. This procedure is particularly effective in light back spot welding, where the backside is relatively short and a quick, reliable start is essential. On the other hand, lava satisfactory results have also been obtained with power sources, which lava a volt-amperage characteristic, Aiken fOreter an initial decrease followed by an increase in the welding area. A characteristic of this kind is achieved with, for example, a power source of the transformer type, which has a mattable reactor type regulation.

Medan en dndring i elektrodmatningsliastighet i beroende av bagdetekteringsmedel liar astadkommit goda starter med enkla elektroder och val av en av namnda typer av kraftkallor liar eliminerat upptradandet av elektrodbakbranning, sâ liar betydande svarighet fortfaran.de mott vid farskaffandet av palitliga starter vid multipelelektroder. I de fiesta fall Or det onsk-vart att alla ljusbagarna starta samtidigt, men i praktiken Or detta svart att uppna. Oin framfaringen hangs svetslinjen startas, innan alla ljrusbagarna tants, komma de ljusbagar, som icke ta.nts, att starta nagon tid senare, efter det att en stracka langs svetslinjen passerats, varigenom en icke komplett svets erhfilles. A andra sidan, om korningen icke startat, forran alla ljusba- 2— — garna tants, sã skulle de forst tanda ljusbagarna brant igenom arbetsstycket eller / palagt icke Onskat stora hogar vid svetsens bar-j an. While a change in electrode feed efficiency depending on bag detection means has achieved good starts with simple electrodes and the choice of one of the mentioned types of power sources has eliminated the occurrence of electrode backburn, so significant responsiveness continues to be obtained in obtaining reliable starts at multiple electrodes. In most cases, it is desirable for all the light beetles to start at the same time, but in practice it is difficult to achieve this. In the process of hanging the welding line is started, before all the light beetles are ignited, the light beetles which are not lit will start some time later, after a distance along the welding line has been passed, whereby an incomplete weld is obtained. On the other hand, if the grinding did not start, before all the candlesticks were ignited, the first candlesticks would burn steeply through the workpiece or / do not place unwanted large heaps at the bar of the weld.

Foreliggande uppfinning Or riktad pa ett salt att svetsa en eller flera arbetsstycken medelst ett flertal ljusbagar, som bildats med hjfilp av ett flertal konsumerbara elektroder (eller medelst en icke-konsumerbar elektrod och en eller flera konsumerbara elektroder) och en ,svetsstromkalla, som har en volt-amperekarakteristik, vilken ar antingen huvudsakligen flack eller stigande i det anvandbara svetsstromomradet, varvid en konsumerbar elektrod forst mains emot arbetsstycket vid en starthastighet och, efter tandning av bagen, vid en annan hastighet lamplig for svetsning. Enligt uppfinningen utmarkes detta satt darav, att en andring i de konsumerbarn alektrodernas (eller elektroden) matningshastighet fordrojes, tills den sista ljusbagen tants. The present invention is directed to a salt for welding one or more workpieces by means of a plurality of light bags formed by means of a plurality of consumable electrodes (or by means of a non-consumable electrode and one or more consumable electrodes) and a welding current source having a volt-amperage characteristic, which is either substantially flat or rising in the usable welding current range, a consumable electrode first being applied to the workpiece at a starting speed and, after ignition of the bag, at another speed suitable for welding. According to the invention, this is marked by the fact that a change in the feed speed of the consumer children (or electrode) is delayed until the last candle bag is ignited.

Uppfinningen askadliggores pa bifogade ritning. Fig. 1 visar en vy av ett typiskt svetsarrangemang enligt uppfinningen med multipelelektroder nedsankta i svetspulver. Fig. 2 visar en bagformig volt-amperekarakteristikkurva hos en kraftkalla av transformatortyp med reaktorreglering och aterkoppling for att tillfora en stigande volt-amperekarakteristik Over atminstone en del av omradet. Fig. 8 visor ett blockschema enligt uppfinningen. Fig. 4 visar en fragmentarisk vertikalsektion av ett inert gasbagsvetsningsarrangemang, utnyttjande ett par konsumerbara elektroder. Fig. 5 visor en liknande sektion med en kombination av en icke-konsumerbar och en konsumerbar elektrod i ett enda gasmunstycke. The invention is illustrated in the accompanying drawing. Fig. 1 shows a view of a typical welding arrangement according to the invention with multiple electrodes immersed in welding powder. Fig. 2 shows a bag-shaped volt-ampere characteristic curve of a transformer-type power source with reactor control and reconnection to supply a rising volt-ampere characteristic over at least a part of the area. Fig. 8 shows a block diagram according to the invention. Fig. 4 shows a fragmentary vertical section of an inert gas bag welding arrangement, utilizing a pair of consumable electrodes. Fig. 5 shows a similar section with a combination of a non-consumable and a consumable electrode in a single gas nozzle.

Sasom visas i fig. 1 matas konsumerbara elektrodtradar eller -stinger 11, 12 och 13 samtidigt igenom styrror 15, 16 och 17 med andamal att overfora svetsspanning till elektroderna. Styrroren Oro medelst ledningar 18, I 9 och 20 elektriskt forbundna med en samlingsskena 10, som i sin tur fir elektriskt forbunden med ena sidan pa en svetsstromkalla eller svetsstromnatanslutning med huvudsakligen flack eller stigande karakteristik atminstone i svetsomradet. Den andra sidan hos en dylik natanslutning Or ansluten till arbetsstycket W. Styrraren kunna vara placerade i nagot Onskat forhallande till varandra, som erfordras for att uppna det onskade resultatet. Under vissa omstandigheter kan det vara nodvandigt att kombinera dem i en enda enhet och under andra forhallanden kan det vara nodvandigt att skilja dem at betydligt. Vid meltsvetsning -Mores ett kornigt svetsmedel G ph arbetsstyckets yin runt elektrodtradarnas andar. Vid inert gasbagsvetsning tillfores en lamplig gas, sasom argon, for att avskarma ljusbagen och narbelagen metall fran atmosfaren. As shown in Fig. 1, consumable electrode wires or stitches 11, 12 and 13 are simultaneously fed through guides 15, 16 and 17 with the aim of transmitting welding voltage to the electrodes. The guide tubes Aro by means of lines 18, I 9 and 20 electrically connected to a busbar 10, which in turn is electrically connected to one side of a welding current source or welding current connection with substantially flat or rising characteristics at least in the welding area. The other side of such a night connection Or connected to the workpiece W. The controller may be located in any desired relationship to each other, which is required to achieve the desired result. In some circumstances it may be necessary to combine them into a single unit and in other circumstances it may be necessary to separate them considerably. In melt welding -Mores a granular welding agent G ph the workpiece yin around the spirits of the electrode tractors. In inert gas bag welding, a suitable gas, such as argon, is supplied to shield the light bag and the adjacent metal from the atmosphere.

Vid vissa typer av natanslutningar kan en stigande volt-amperekarakteristikkurva ernas i blott en del av utstromsouaradet. Exernpelvis kan en natanslutning av transformatortyp med mattad aterkopplaretypreglering hava en volt-amperekarakteristikkurva ABFCD, sasom visas i fig. 2. Tomgangsspanningen Or ganska hog sasom visas av punkten A pa kurvan. Allteftersom belastningsstrommen Okas, sjunker spanningen till ett minimumvarde vid punkten B. Ytterligare aiming i belastningsstrom medfor en stigande voltamperekarakteristik till punkten C, efter volt-amperekarakteristiken blir tamligen flack eller sjunker obetydligt till punkten D. In some types of night connections, a rising volt-ampere characteristic curve may be present in only a portion of the outflow souarad. For example, a transformer-type night-time connection with a mated reconnector-type control may have a voltage-ampere characteristic curve ABFCD, as shown in Fig. 2. The idle voltage Or is quite high, as shown by point A on the curve. As the load current Okas, the voltage drops to a minimum value at point B. Further aiming in load current results in a rising voltmeter characteristic to point C, after the volt-amperage characteristic becomes rather flat or drops insignificantly to point D.

Det anvandbara svetsstromomradet Or mellan punkterna B och D ph den bagformiga delen av kurvan. Fran punkterna B till C Or karakteristiken den hos en stigande volt-amperenatanslutning och frau C till D den hos en konstant potential eller >fallande> natanslutning beroende pa den negativa lutningens storlek. The usable welding current range Or between points B and D ph the bag-shaped part of the curve. From points B to C Or the characteristic of a rising volt-amperage connection and from C to D it of a constant potential or> falling> night connection depending on the magnitude of the negative slope.

Problemet med flerhagstandning losas nar ljusbagarna tandas vid lagre On normal stromstyrka och, nar alla de normala stromstyrkorna till ljusbagarna och framforingen automatiskt emblems nar begynnelseljusbaaarna hrinna vid alla elektroderna. Delta astadkommes latt med en strOmkalla som ham en bagformig volt-amperekarakteristik, genom att forst tanda alla ljusbagarna vid laga tradmatningshastigheter och sedan vaxla Over till normala tradmatningshastigheter, nfir alla ljusbagarna tants. En dylik procedur undanrojer uppkomsten av of ullstandiga svetsar, genombranningar och stoma anhopningar i borjan av svetsen. The problem of multi-stroke is solved when the light beams are lit at low On normal current and, when all the normal currents to the light beams and the feed are automatically emblems when the initial light beams run at all the electrodes. Delta is easily achieved with a current cold like him a bag-shaped volt-amperage characteristic, by first turning on all the light beetles at low wire feed speeds and then switching Over to normal wire feed speeds, nfir all the light beetles tants. Such a procedure eliminates the occurrence of incomplete welds, burns and stoma accumulations at the beginning of the weld.

Det ideala sattet Or att starta ljusbagen yid reducerad tradmatningshastighet och ingen eller lag .framforingshastighet och sedan gradvis Oka bade tradmatningshastigheten och framforingshastigheten, allteftersom varmen i arbetsstycket stiger, tills normala tradmatnings- och framforingshastigheter uppnatts. I praktiken har det visat sig, att utforande av Overgangen i tva steg Or tillrackligt. The ideal way is to start the candle bag at a reduced wire feed rate and no or low feed rate and then gradually increase both the wire feed rate and the feed rate as the heat in the workpiece rises until normal wire feed and feed rates are reached. In practice, it has been found that the execution of the transition in two steps is sufficient.

En natanslutning, som producerar voltamperekurvan enligt fig. 2, blir emellertid icke bakbranningssaker, emedan svetsstrommen i punkten B Or i stand att understodj a en ljusbage, eftersom den stigande spanningen mellan punkterna B och A saes bibehalla ljusbagen, tills en hakbranning intraffar. Dar-for Or det onskvfirt att avbryta ljusbagen en punkt F, eftersom bagstrOmmen redueeras fran det normala svetsstrOmomradet, om bakbranningsskydd onskas. En annan mojlig losning Or att artifieiellt belasta natanslutningen till punkten B medelst ett motstand eller annat lampligt medel. Darefter kommer den »nya» obelastade tomgangsspanningen att bliva punkten B fon an A. Eftersom saledes sek- — —3 tionen mellan A och B eliminerats, kommer det icke att bliva nagon hakbranning. However, a wet connection producing the voltmeter curve of Fig. 2 does not become backburned, because the welding current at point B or is able to support a light bag, since the rising voltage between points B and A is said to maintain the light bag until a hook burn occurs. Therefore, it is undesirable to interrupt the light bag at a point F, since the backflow current is reduced from the normal welding current range, if backburn protection is desired. Another possible solution Or to artificially load the nate connection to point B by means of a resistor or other suitable means. Thereafter, the "new" unloaded idle voltage will become point B fon an A. Since thus the section between A and B has been eliminated, there will be no hook burning.

En lOsning av problemet att avbryta ljusbagarna ar att forst stoppa tradmatningen och att bryta bagstrommen vid en forutbestamd senare tidpunkt. Detta satt stoppar konsekvent ljusbagarna pt onskat aystand fran arbetsstycket, vilket avstand bestammes av lidsfOrloppet mellan stoppandet av tradmatningen och brytandet av svetsstrommen. A solution to the problem of interrupting the light beetles is to first stop the wire feeding and to interrupt the backing drum at a predetermined later time. This set consistently stops the candlesticks at the desired distance from the workpiece, which distance is determined by the lid course between the stopping of the wire feed and the breaking of the welding current.

En elektroniskt reglerad shuntmotor kan anvandas som tradmatningsmedel. For att stoppa tradmatningen anvandes foljande forfarande: (a) Motorns ankare berovas sin energi och kortslutes medelst ett motstand fOr att astadkomma dynamisk bromsning. (b) Vid en senare forutbestamd tidpunkt brytes bagstrommen. Motorn kan ha eller har icke stoppats fullstandigt vid den tidpunkt dâ bagstrommen brytes. Delta beror pa stone-ken av bromsverkan och tidsintervallet mellan tillslagning av bromsen och brytandet ay bagstrommen. Dylik kombination kommer att astadkomma bade kraterelimination och stoppande ay antistickning sarskilt for tunna arbetsstyeken. An electronically controlled shunt motor can be used as a wire feed. To stop the wire feed, the following procedure was used: (a) The motor anchors are deprived of their energy and short-circuited by means of a resistor to achieve dynamic braking. (b) At a later predetermined time, the rear drum is broken. The engine may or may not have stopped completely at the time the rear drum is broken. Delta depends on the degree of braking action and the time interval between applying the brake and breaking the rear drum. Such a combination will provide both crater elimination and stopping ay anti-stick especially for thin workpieces.

Fig. 3 askadliggor ett typiskt regleringsarrangemang utnyttjande reducerad hastighet for starten och antistickningsmedel for att stoppa svetsverkan. Svetsstromkallan eller natanslutningen 21 har en bagformig voltamperekarakteristik och är fOrbunden med samlingsskenan 10 och arbetsstycket W me-deist ledningar 22 och 23. Samlingsskenan 10 hi- forenad med styrroren 15, 16 och 17 medelst ledningar 18, 19 och 20. Ett stallbart hastighetsregleringsmedel 24 reglerar tradmatningsmotorns M hastighet genom en le-dare 35. Denna reglering astadkommes me-deist en regleringsanordning 28 for den reducerade starthastigheten och en annan regleringsanordning 29 for svetshastigheten samt awn medel for overawing frail start- till svetshastighet. En bagdetektor 25 i var och en ay ledningarna 18, 19 och 20 ãr forbunden med hastighetskontrollen medelst ledare 26. Nar signaler astadkommits frail var och en ay detektorerna 25, overfores tradmatningen frail start- till svetshastighet. Fig. 3 shows a typical control arrangement utilizing reduced speed for the start and anti-stick means for stopping the welding action. The welding current source or night connection 21 has a bag-shaped voltampering characteristic and is connected to the busbar 10 and the workpiece W with lines 22 and 23. The busbar 10 is connected to the guide tubes 15, 16 and 17 by means of lines 18, 19 and 20. An adjustable speed control means 24 regulates the speed of the wire feed motor M through a conductor 35. This control is achieved by means of a control device 28 for the reduced starting speed and another control device 29 for the welding speed as well as means for overawing frail starting to welding speed. A bag detector 25 in each of the wires 18, 19 and 20 is connected to the speed control by means of conductor 26. When signals are received from each of the detectors 25, the wire feed is transmitted from the starting to welding speed.

Bagdetektorerna 25 kunna vara stromrelan eller andra lampliga anordningar. Utom att tjana till att overfora den. stallbara hastighetsregleringen 24 fran start- till svetshastighet kunna de aven anvandas for att etablera framforingen eller att starta en svetstidregulator. En enda kan vara anbragt i den gemensamma jordledningen eller i elektrodledningen till den trad som matas med den lagsta hastigheten. En hjalpreglering 31 är forsedd med svetsstart- och stoppmedel 32 resp. 33 och kan aven omfatta andra regleringar for gas, vatten, svetsvagnskorning, tillforsel av tillsatstrad etc. Ett tidfordrOjningsrela 34 pa.- verkar en kontaktanordning 30 for framslapp ning av strom i ledare 22 till svetstraden, sk snart svetsstartmedlet 32 paverkas. Nfir svetsstoppmedlet 33 paverkas fortsatter relaet 34 ;svetsstromtillforseln under en forinstalld tid; bestamd am dess installning. The bag detectors 25 can be the current relay or other suitable devices. Except to serve to transmit it. adjustable speed control 24 from start to weld speed, they can also be used to establish the feed or to start a welding time controller. A single one may be located in the common ground wire or in the electrode wire of the wire being fed at the lowest speed. An auxiliary control 31 is provided with welding start and stop means 32 resp. 33 and may also comprise other controls for gas, water, welding carriage grain, supply of additive wire, etc. A time delay relay 34 acts on a contact device 30 for advancing current in conductor 22 to the welding wire, so-called soon the welding starting means 32 is actuated. When the welding stop means 33 is actuated, the relay 34 continues, the welding current supply for a preset time; determined at its installation.

Kretsen, fig. 3, tjanstgor pa foljande satt, nar svetsstartmedlet 32 paverkas: Svetstra.- darna 11, 12 och 13 givas energi genom att kontaktanordningen 30 i ledaren 22 slutes. Tradmatningsmotorn_ M matar alla tre Iradarna emot arbetsstycket W med en starthastighet, som âr bestamd ay hastighetsregleringen.s 24 installning. Tradarna bestryka arbetsstycket och tanda deras respektive ljusbagar. liven fastan alla tradarna matas med samma hastighet, Or icke en perfekt install-fling av tradarnas andar i linje sa latt att uppna i praktiken och fOljaktligen blir flagon av tradarna den forsta att tanda en ljusbage. Nar bagdetektorerna 25 avgjort -att alla tre ljusbagarna etablerats, andrar hastighetsregleringen 24, sasom ett resultat ay en signal Iran varje forbindelse 26, tradmatningshastigheten fran start- till svetshastighet. Samma regleringsmedel kan anvandas for att borja framforingen eller Oka hastigheten darav samtidigt med en. andring i tradmatningshastigheten. Nar ljusbagarna hava varat sa lange som onskat, piiverkas syetsstoppmedlet 33. Tra.dmatnin.gsmotorn M forlorar sin effekt och stoppas av lampliga medel sasom dynamisk bromsning. Tidfordrojningsmedlet 34 fortsatter att bibehalla ljusbagarna genom att halla kontaktanordningen 30 sluten under en lamplig forutvald lid, efter del att motorn M forlorat sin effekt. The circuit, Fig. 3, serves as follows when the welding starting means 32 is actuated: The welding beams 11, 12 and 13 are energized by closing the contact device 30 in the conductor 22. The wire feed motor_ M feeds all three Iradars against the workpiece W at a starting speed, which is determined by the speed control.s 24 installation. The traders coat the workpiece and tooth their respective candle holders. life though all the trades are fed at the same speed, Or not a perfect install-fling of the trades' spirits in line so easy to achieve in practice and consequently the flag of the trades becomes the first to light a candle bag. Once the bag detectors 25 have been determined - that all three candle beetles have been established, the speed control 24, as a result of a signal from each connection 26, changes the wire feed speed from start to welding speed. The same control means can be used to start the feed or increase its speed at the same time as one. change in wire feed speed. When the candle holders have lasted as long as desired, the sewing stop means 33 is actuated. The traction feed motor M loses its power and is stopped by suitable means such as dynamic braking. The time delay means 34 continues to maintain the light beetles by keeping the contact device 30 closed during a suitable preselected lid, after the motor M has lost its power.

Svctsstoppmedlet 33 kan vara vilken som heist läiiplig anordning. Exempelvis strombrytare och tryckknappar kunna anvandas for manuella operationer och svetstidregulatorer eller grfinslagebrytare kunna anvandas for automatiska operationer. Anordningar sitsom vatten- och gasregulatorer, gasstromningsreglerare, svetsvagnsdrift- och tillsatstradreglerare, vilka aro normala delar av manga svetsinstallationer, kunna vara inkluderade, men Oro icke visade i fig. 3. The weight stop means 33 may be any suitable device. For example, circuit breakers and pushbuttons can be used for manual operations and welding time controllers or limit switches can be used for automatic operations. Devices such as water and gas regulators, gas flow regulators, welding trolley drive and additive regulators, which are normal parts of many welding installations, may be included, but concerns are not shown in Fig. 3.

Aven om tre ljusbagar 1, 2 och 3 visas, sit galla samma principer om tvit eller men an tre ljusbagar anvandas. Even if three candlesticks 1, 2 and 3 are shown, the same principles apply if two or three candlesticks are used.

Enligt en modifikation ay uppfinningen kan varje tradelektrod matas am oberoende drivanordningar, varvid alla tradarna matas ned vid i forvag valda starthastigheter, bestamda genom separata hastighetsregleringars 24 installningar. Var och en av tradarna bestryker arbetsstycket och -ander sina re spektive ljusbagar. Starthastigheten kan installas till att mata exempelvis trader" 3 med en lagre hastighet On tradarnas 1 och 2, &a att ljusbagarna 1 och 2 dragas forst foljcla av ljusbagen 3. Nar ljusbagen 3 tants, paverkar den bagdetektorn 25, som, genom forbindningen 26 (heldragen linje i fig. 3) till hastig- 4— — hetsregleringen 24, overfor alla tradarna fran start- till svetshastighet. Eftersom den sista ljushagen alltid Uncles yid elektroden med den lagsta starthastigheten, erfordras endast ett enda hagdetekteringsmedel placerat i den langsammast sig rorande elektrodens svetsstromkrets. According to a modification of the invention, each wire electrode can be fed by independent drive devices, all the wires being fed down at preselected starting speeds, determined by separate speed control 24 installations. Each of the traders covers the workpiece and -and their respective light beetles. The starting speed can be installed to feed, for example, trader "3 at a lower speed On the trades 1 and 2, & a that the light beetles 1 and 2 are first pulled followed by the light bag 3. When the light bag 3 is turned on, it affects the bag detector 25, which, through the connection 26 line in Fig. 3) to the speed control 24, opposite all the wires from start to weld speed Since the last light path is always the Uncles yid electrode with the lowest starting speed, only a single hag detection means placed in the slowest moving electrode welding circuit is required .

Fordelar med uppfinningen aro foljande: Det forhallandet att tva eller flera ljusbagar kunna tillforas medelst en enda generator ãr tydligen billigare an att utnyttja en strainkalla far varje ljusbage. Advantages of the invention are as follows: The ratio that two or more candle bags can be supplied by means of a single generator is obviously cheaper than using a very cold father of each candle bag.

De separata ljusbagarna kunna anvandas pa antingen ett enda arbetsstycke eller pa tva eller flera arbetsstycken. The separate candle holders can be used on either a single workpiece or on two or more workpieces.

De separata ljusbagarna kunna matas in i samma smalta, eftersom anyandning av en enda bagformad stromkalla tillater att ljusbagarna bringas tatare tillsammans an vid konventionella strOmkallor. The separate light beetles can be fed into the same narrow, since the inhalation of a single bag-shaped current source allows the light beetles to be brought closer together with conventional current sources.

Da tva eller flera gasavskarmade ljusbagar matas fran en stromkalla med konstant potential eller stigande volt-ampere, kunna de tva eller flera ljusbagarna befinna sig mom samma gasmunstycke. Since two or more gas shielded light beetles are fed from a cold source with constant potential or rising volt-amperes, the two or more light beetles may be located at the same gas nozzle.

En icke-konsumerbar elektrod med gasavskarmad ljusbage kan forses med strain fran en flack eller stigande volt-ampereström- kiillaljusbagen kan regleras genom 118j- -fling eller sankning av elektroden. En ickekonsumerbar elektrod och en konsumerbar elektrod kunna matas Iran samma strom- med konstant potential eller stigande volt-ampere. Den icke konsumerbara elektroden kan anvandas far att forsegla svetsfogens bottenyta eller rot, under del. ail den konsumerbara elektroden kommer att tillfora metall far att fylla fogen eller rannan. Den konsumerhara elektroden kan vara antingen gasavskarmad eller nedsankt i pulyerskydd. Da bade den icke-konsumerbara elektroden och den konsumerbara elektroden Oro av gasavskarmad typ, kan ett gemensamt gasmunstycke anvandas. Fig. 4 visar ett exempel pa tva tradar 42 och 43, som matas igenom och frail ett enda gasmunstycke 41, vilket avgiver skyddsgasen. Ledaren 4ti forenar styrroren 44 och med stromkallan. Fig. 5 visar ett liknande arrangemang, varvid en icke-konsumerbar elektrod 48 är i samma gasmunstycke som den konsumerbara elektroden 43. Elektroden 48 kan vara av volfram eller annat lampligt material. A non-consumable electrode with a gas shielded light bag can be fitted with strain from a flat or rising volt-amperage current. The light bag can be regulated by fusing or lowering the electrode. A non-consumable electrode and a consumable electrode can be supplied to Iran in the same current with constant potential or rising volt-amperes. The non-consumable electrode can be used to seal the bottom surface or root of the weld, under part. ail the consumable electrode will supply metal father to fill the joint or gutter. The consumer-hard electrode can be either gas-shielded or immersed in a polyurethane protection. Then both the non-consumable electrode and the consumable electrode Oro of gas shielded type, a common gas nozzle can be used. Fig. 4 shows an example of two wires 42 and 43, which are fed through and from a single gas nozzle 41, which emits the shielding gas. The conductor 4ti unites the guide tubes 44 and with the power source. Fig. 5 shows a similar arrangement, in which a non-consumable electrode 48 is in the same gas nozzle as the consumable electrode 43. The electrode 48 may be of tungsten or other suitable material.

Vid det beskrivna flerbagsattet behova de tva 'eller flera ljusbagarna icke matas in i samma smalta. De tva eller flera separata ljusbagarna kunna lagga ned en enda strang pa samma arbetsstyeke eller de kunna lagga ned separata strangar pa samma arbetsstycke eller pa olika arbetsstycken. De behova icke nadvandigtvis matas igenom ett gemensamt munstycke eller ens medelst samma tradmatningsmedel. In the case of the described multi-baked, the two or more light beets need not be fed into the same narrow. The two or more separate candle holders may lay a single strand on the same workpiece or they may lay down separate strands on the same workpiece or on different workpieces. They do not necessarily need to be fed through a common nozzle or even by the same wire feed means.

Tv& eller flera ljusbagar I flerbagsystemet kunna paverkas vid gamma svetsstyrkor eller vid olika svetsstyrkor 'for att passa for svetsurbetets fordringar. Till exempel: (a) Om alla tradarna hava samma grovlek och sammansattning och drivrullarna hava samma diameter, bliva svetsstyrkorna i alla Ire ljusbagarna huvudsakligen de samma. (b) Om tva eller flera tradar matas med samma hastighet, men de tva tradarna skilj a sig betraffande diameter, sa blir bagstromstyrkan for var och en av bagarna olika, eftersom strain-men i varje ljusbage kommer att justera sig spiv till att branna av den ifragavarande tradgrovleken vid den hastighet, som den matas med. (c) Genom att anvanda olika diametrar pa drivrullarna, som drivas av en gemensam motor, kan matningshastigheten hos vilken som heist trad bliva fOrutbestamd relativt vilken som heist annan trad. (d) De tva eller .flera tradarna kunna matas fran tva eller flera tradmatningsaggregat, varigenom fullstandigt oberoende stromkontroll for var och en. av tradarna kan ombesarjas. Two or more light bags In the multi-bag system can be affected at old welding strengths or at different welding strengths' to suit the requirements of the welding surbet. For example: (a) If all the wires have the same coarseness and composition and the drive rollers have the same diameter, the welding strengths in all the Irish candle holders will be essentially the same. (b) If two or more threads are fed at the same speed, but the two threads differ in diameter, then the rear current strength of each of the bakers will be different, since the strain in each candle bag will adjust the spike to burn off. the tree grove in question at the speed at which it is fed. (c) By using different diameters of the drive rollers, which are driven by a common motor, the feed speed of which one has threaded can be predetermined relative to which one of the other threads. (d) The two or more wires may be fed from two or more wire feeders, thereby providing completely independent power control for each. of the traders can be rescheduled.

De olika stromregleringsmedlen, som ovan beskrivits, tillhandahalla stor smidighet svetsningen. Till exempel: (a) En rotstrang kan framstallas vid lag stromstyrka, under det att en foljande ljusbage med tillsatsmetall kan tjanstgora vid en lamplig, hogre svetsstyrka. (b) Vid platering eller pasvetsning kan det vara onskvart att lagga en kraftig strang i centrum och samtidigt lagga en tannare strang longs kanterna. (c) Da avfasade s-vetsfogkanter anvandas, kan det Tara ;Riskvart att lagga en kraftig strang till centrum och tunnare strang emot kanterna pa arbetsstycket for anpassning after den till »theller »V»-form fasade svetsfogen. (d) Ett flerbagsystem med konstant potential eller stigande volt-ampere kan Oven utnyttjas for att nedlagga metall frail tva eller flora tradar med olika sammansattning. Detta kan anvandas for att: (1) Ombesorj a en legeringsstrang, som kan regleras genom variation av matningshastigheten for de tva eller Hera integrerande tradarna. (2) Ombesorja en tillsats- eller pasvetsstrang faljd av ett overlag av olika material. The various current regulators, as described above, provide great ease of welding. For example: (a) A root strand can be produced at low current, while a subsequent light bag with additive metal can serve at a suitable, higher welding strength. (b) When plating or fitting welds, it may be unwise to lay a strong strand in the center and at the same time lay a thinner strand along the edges. (c) When bevelled s-weld joint edges are used, it may be advisable to lay a strong strand to the center and thinner strand against the edges of the workpiece for adaptation after the welded joint to the "th" V "shape. (d) A multi-bag system with constant potential or rising volt-amperes can also be used to lay metal frail two or flora trades of different composition. This can be used to: (1) Provide an alloy strand, which can be regulated by varying the feed rate of the two or Hera integrating wires. (2) Arrange an additive or fitting strand folded by an overlay of different materials.

Ett vaxelstromsflerbagsystem med konstant potential eller stigande volt-ampere ligger mom den beskrivna uppfinningens ram. Samtidigt Or ett system med tva- eller trefas konstant potential eller stigande volt-ampere, varvid tva, eller flera ljusbagar underhallas av systemet, likaledes mom uppfinningens ram. An alternating current multi-current system with constant potential or rising volt-amps is within the scope of the described invention. At the same time Or a system with two- or three-phase constant potential or rising volt-amperes, whereby two or more light beams are maintained by the system, likewise within the scope of the invention.

ANen om uppfinningen beskrivits ovan sasom speciellt lamplig for gas- eller pulveravskarmad bagsvetsning, sa Or den Oven lamp-hg far olika variationer och kamhinationer som torde vara tydligt for den pa omradet sakkunnige. — —Although the invention has been described above as particularly suitable for gas- or powder-shielded back-welding, the above-mentioned lamp-hg has various variations and combinations which should be apparent to the person skilled in the art. - -

Claims

Patent claim:

Salt for welding one or more workpieces by means of a plurality of light bags, which are formed by means of a plurality of consumable electrodes (or by means of a non-consumable electrode and one or more consumable electrodes) and a welding energy source having a voltage tamper characteristic, which is either substantially flat or rising in the usable welding area, a consumable electrode first being fed against the workpiece - at a starting speed and, after ignition of the bag, at another speed suitable for welding, characterized in that changing the feed rate of the consumable electrodes (or electrode) delayed, until the last candle bag tants.

2. San according to claim 1, wherein a plurality of consumable electrodes are fed against the workpiece at the same starting speed, characterized in that changing of the feeding speed is performed depending on the flow of high current through all these electrodes simultaneously.

Salt according to claim 1, wherein a plurality of consumable electrodes are fed against the workpiece at different starting speeds, characterized in that the change in feed speed is carried out depending on the flow ay backstream through the electrode moving against the workpiece at the lowest starting speed.

Salt according to any one of the preceding claims, wherein relative motion is carried out between the electrodes and the workpiece along a welding path, characterized in that this relative motion is initiated or increased at a speed simultaneously with a change in the feed rate of the consumable electrodes or electrode.

5. A salt according to any one of the preceding claims, wherein an ordinary energy source is used and has a volt-amperage characteristic giving an initial descending sequence of a rise in the welding area, which includes the termination of the welding action by first interrupting the electrode supply and then interrupting. the current flow, may be characterized by the fact that the current flow is interrupted before the welding current delivered to the different light bags has reached such a value that a further reduction of the current causes a voltage increase.

An apparatus for carrying out the kit according to any of the preceding patent claims, which includes a supply means for a plurality of consumable electrodes (or support means for a non-consumable electrode and supply means for one or more flora consumable electrodes), a welding energy source with one volt ampere characteristics, which are either substantially flat or rising in the usable welding area, and a control means, for changing the speed of said feedstock from a color-selected starting speed to the speed required for welding Depending on a detecting means, characterized in that said rear detecting means is arranged to act on said regulating means when the rear drum flows in at least the welding circuit of the slowest fed electrode.

Apparatus according to claim 6, which comprises feeding means arranged to feed a plurality of consumable electrodes against the workpiece at the same speed, characterized in that a rear detector Or is arranged in each electrode welding circuit and that the regulating means is operative when all the rear detecting means are energized simultaneously. 8.

Apparatus according to claim 6, which comprises supply means arranged to supply one of a plurality of consumable electrodes at a lower speed. Rol. the other, can be characterized in that a bag detector is arranged in the welding circuit of only the most moving electrode and that the regulating means is effective when said bag detecting means is given energy.

9. Apparatus according to claim 8, characterized in that said feed means comprises drive rollers of different diameters driven by a common motor. Request publications: