Device for arc multielectrode welding
(57) Abstract:The device can be used for welding corner joints of rectangular tubes. Protective camera posted by the weld head from several blocks of electrodes, sequentially mounted on brackets in the General elds of application. The blocks are electrically connected and fixed on a stand-alone product the clamp using consoles can be rotated relative to them. The number of blocks equals the number of joints of the parts to be welded head. The number of electrodes in each block is selected depending on the required length of the seam and the diameter of the point to be welded to one electrode per cycle. Against the working ends of the electrodes are located the ends of the cores of the solenoids, mounted in a common holder and connected to the source of their power through the device software of the switching current. The proposed device can improve performance and simplify the design of the equipment due to the lack of necessary isolation of the electrodes and blocks from each other, as well as the lack of separate leads to each electrode. 4 Il. The invention relates to mechanical engineering and can be used, for example, fujimura Harosi, Inoue, Hironori, application N 63313674, Japan, from 21.12.88,, R j 1.63.263 P, 1990), according to which welding perform several consumable electrodes with the formation of a common bath. Wire each electrode served by individual mechanism through a copper current-carrying tube. All tubes are collected in the beam and electrically isolated from each other. The power of each electrode is produced independently from a separate current source. In the middle of the beam, not reaching the lower end of the supply circuit through the same tube serves a protective gas. The entire Assembly of tubes is placed in a surrounding nozzle to form a stream of gas that protects the weld pool from the air. The result is high performance welding process, improves weld formation and reduced the consumption of protective gas. But there is a method complicates the equipment due to the need for Autonomous power supply of each electrode from a separate power source.There is also known a method multielectrode arc welding (Kazakov, Y. C., A. Akimov Century, USSR author's certificate N 1779504 from 02.01.91 year), according to which to perform the welding mainly of thin-sheet structures by multiple electrodes. The welding voltage is simultaneously the RCA is conducted according to a given program. To do this consistently ignite an arc on another electrode by disabling it transverse magnetic field. When welding by this method through the use of multiple electrically interconnected electrodes and ignition control of the arc by switching low-voltage circuits simplifies the design of the welding head and saves energy. However, this method for welding short seams, such as truss structures of rectangular cross-section tubes, require moving the electrodes after each welding seam on the new section of the joint parts and re-configuration of the electrodes on the joint. This increases the complexity of the welding process.The known method and device for arc welding (Henry Thomas Leiby, patent N 3114829, USA from 17.12.1963 g), which is taken as a prototype. In this way the welding are several non-consumable electrodes, which have consistently along the welded joint. The electrodes are alternately included in the welding circuit. Each electrode performs welding one point that overlap each other. To protect metal weld pool from the front and from the back side of the joint apply chamber filled with protective gas. This method allows increasing stvie, each electrode should be provided with a separate power cable, electrodes need to be isolated from each other and the device must be equipped with a power switch of the welding current. In addition, when welding short seams frame designs, for example of rectangular pipes, the device according to the prototype as well as previous similar, will require frequent shifts of electrodes and re-configure them on the new joint parts, which will increase the complexity of the welding process.The technical problem to be solved by the proposed device, the simplification of the equipment and improving the performance of the welding process.The proposed device has a security camera installed in her welding head containing several series set nonconsumable electrodes fixed in the elds of application and connected to a common power source of the welding arc. Unlike the prototype welding head consists of several blocks of welding electrodes, electrically connected to each other. Blocks fixed on a stand-alone from a welded product the clamp using consoles can be rotated relative to them and provided with brackets for mounting the electrodes in ookoi. The number of electrodes in each block is determined from the expression
< / BR>where L is the length of the seam, performed by this unit, mm;
dm- diameter point, welded one electrode for the cycle.Each electrode is provided with a solenoid, the end face of the core which is against the working end of the electrode. The solenoids are enshrined in the common holders and connected to the source of their power through the device software of the switching current.This set of new features with the known will improve the performance of the welding process designs with a large number of short welded joints due to the fact that will provide the opportunity to automate this process. In turn, this capability will be provided to simplify the design of the device due to the fact that become unnecessary contact to each electrode and eliminates the need for switching high-current circuits.The device illustrated in the drawings. In Fig. 1 shows a diagram of the device of Fig. 2 is a front view; Fig. 3 is a top view; Fig. 4 is a left side view of the welding head.The proposed device contains protective camera 1 installed in her welding head, consisting of several the power 3 of the welding arc. Blocks 2 electrodes 13 are electrically connected and fixed on a stand-alone from a welded product the yoke 5 by means of consoles 6,7,8 and 9 can be rotated relative to them. The electrodes 13 are enshrined in the General elds of application 11 by brackets 10. Each electrode 13 is provided by the solenoid 12, the end face of the core of each solenoid 12 is located against the working end of the electrode 13. The solenoid 12 is fixed in the General solenoidoperated 14 and is connected to the source 15 of their power through the device 4 software switching current. The number of blocks 2 is chosen equal to the number of joints in the joint parts welded node 16, a welded head. The number of electrodes 13 in each block 2 is determined from the expression
< / BR>where L is the length of the seam, performed by this unit, mm;
dm- the diameter of the point to be welded to one electrode per one cycle of its operation.The proposed device operates as follows. On Shrivenham node 16, for example T-shaped junction of two pipes of rectangular cross section, establish and fix isolated from node 16 to the clamp 5. When using consoles 6,7,8 and 9 fixed units 2 installed in series with a consumable, such as tungsten, electrode 13. The number 16. The number of electrodes 13 in each block 2 is determined from the expression
< / BR>where L is the length of the seam, performed by this unit, mm;
dm- the diameter of the point to be welded to one electrode per one cycle of its operation.The choice of the limit of the ratio in the denominator of this expression is due to the fact that when it is less than 0.4 on the reverse side of the seam will not overlap points, welded to each of the electrodes 13, and a value of more than 0.8 points will be almost completely re-molded, which reduces the efficiency of the process. In both cases, will decrease the quality of welds.In blocks 2 electrodes 13 are enshrined in the General elds of application 11 by brackets 10 and connected to a common power source 3 of the welding arc, the other pole of which is connected to being welded to the node 16. All electrodes 13 provided with a solenoid 12, the ends of the cores which have working against the ends of the electrodes 13. The solenoid 12 is fixed in the General solenoidoperated 14 and connected to a separate power source through the device 4 software switching current. Blocks 2 is fixed on the consoles 6,7,8 and 9 can be rotated relative to them, which allows you to set the electrode 13 at an acute angle to the surface with the beam joint (Fig. 4). Top assembled from blocks 2 welding heads install a protective chamber 1, which can be used any camera of known construction, such as hard Luggage of two halves that are fitted with seals in the connector and along the perimeter of the covered parts, fittings for the supply of the protective gas and the output power and the switching wires. The chamber 1 is filled, for example, by purging with inert gas, which can be taken argon. The voltage from the power source 3 arc serves simultaneously to all electrodes 13 all the blocks 2 are electrically connected to each other. At the same time through the device 4 software switching current serves voltage from the power source 15 for all the solenoids 12, which generate transverse relative to the axis of the electrodes 13 a magnetic field that prevents the ignition of the welding arc. The device is shown in its original state before welding.The welding process begins, tearing through the device 4 software switching power supply circuit of one of the solenoids 12. Against the working end of the respective electrode 13 will stop the influence of a transverse magnetic field between the end face of the electrode and the surface being welded is not to be energized from the power source 15. During arcing under the electrode 13 is formed welded dot diameter dm. Then the device 4 according to a given program applies a voltage from the power source 15 to the solenoid 12 and turn it off on another solenoid 12. The cycle will be repeated until then, until you form a weld point under the last of the electrodes 13 each block 2. Point mutually overlap forming a continuous weld seam. Welding can be carried out without additives or filler material, pre-Packed in the joint parts. As the device 4 soft switch current can be applied to any known switch, assembled, for example, from commercially available stepper seekers. Such a switching device can provide any sequence of excitation of the arcs from the electrodes 13, which will reduce the voltage at the welding site 16.The proposed device is compared with the prototype has a more simple construction, since it does not require connecting a separate power leads to each electrode and does not require isolation of the electrodes 13 and 2 blocks from each other. Switching the ignition arc across the electrodes 13 is in the low voltage circuits of the solenoids 12, which simplifies the design of the device 4 commutation parts welded node 16, its functions will be to only install the blocks 2 welding heads and protective camera 1 on welded joints of parts and removing them after welding. These operations it can perform on some joints parts at a time when other joints is welding. The result will increase the productivity of the process.Thus, the proposed device provides a technical effect and can be constructed and applied using means known in the art. Therefore, the proposed device for arc multielectrode welding has industrial applicability. Device for arc multielectrode welding containing protective camera installed in her welding head with multiple sequentially fixed in the elds of application with non-consumable electrodes connected to a common power source arc welding, wherein the welding head consists of several blocks of welding electrodes connected electrically with each other, the blocks are fixed on a stand-alone from a welded product the clamp using consoles can be rotated relative to them and provided with brackets for mounting the electrodes in General electrodata electrodes in each block is determined from the expression
< / BR>where L is the length of the seam produced by the unit, mm;
dm- the diameter of the point to be welded to one electrode per cycle,
each electrode is equipped with a solenoid, the end face of the core which is against the working end of the electrode, and the solenoids are enshrined in the common holders and connected to the source of their power through the device software of the switching current.
FIELD: restoration of parts cast of aluminum alloys with use of fusion welding.
SUBSTANCE: method comprises steps of cutting out flaw containing portion spaced equidistantly by distance (3 - 8)n from boundary of flaw; making insert of deformed aluminum alloy welded with casting alloy of restored part at relation of coefficients of percentage elongation Gd/Gc = 9 - 25, where Gd and Gc coefficients of percentage elongation respectively of deformed and casting aluminum alloys, n - thickness of cast part in restoration zone.
EFFECT: lowered labor consumption at restoring parts of aluminum alloys.
3 dwg, 1 tbl
FIELD: processes for making large-size thick-sheet orthotropic plates of carbon low-alloy steels in different branches of industry, particularly for bridge building.
SUBSTANCE: method comprises steps of relative orienting members of orthotropic plates; tack welding oriented members by means of non-consumable tungsten electrode in mixture of shield gases Ar (95 - 97)% + (3 - 5%) CO2 ; performing automatic continuous-seam welding and then trimming surface of welded seam. It allows simplify method for making welded large-size thick-sheet orthotropic plates of carbon low-alloy steels.
EFFECT: lowered labor consumption, shortened time cycle for making enhanced-quality plates, improved reliability of welded structures.
6 dwg, 1 ex
FIELD: electric arc welding of materials by means of non-melting electrode, namely methods for automatic argon-arc pulse welding of steel tubes.
SUBSTANCE: method comprises steps of preliminarily dressing tube butts and forming annular chamfers on inner surfaces of butts; abutting tubes; moving welded edges relative to electrode by step axial rotation of abutted tubes at revolution number 1 -1.5 rev/min; igniting arc 2 - 5 s before starting rotation of tube in order to heat welded seam zone; performing welding by means of torch inclined to tube axis by angle 60 - 85° relative to vertical line; sustaining electric current intensity in range 110 - 155 A for pulse duration 0.7 - 0.9 s; keeping electric current at pause period in range 10 - 30 A for pulse duration 0.5 - 0.7 s. Overlapping value of welded seam is in range 10 - 25 mm. It allows eliminate cracking of welded seam of tubes at bending samples by angle exceeding 160°.
EFFECT: enhanced quality of welded seam of tubes.
3 dwg, 1 tbl
FIELD: automatic welding increased-thickness joints of titanium alloys in inert gas by means of submerged tungsten electrode.
SUBSTANCE: method comprises steps of forming in welded edges cutout which is in the form of П-shaped dressing of edges at welding parts with slit gap; keeping relation of depth of dressing to its width less than 1; rounding acute angles of dressing; before welding introducing granulated additive material into slit gap and performing first pass at minimally admissible value of shape factor of fusion. In order to provide guaranteed fusion of walls, second and third passes are realized in the same mode. Electrode is placed in such a way that it is shifted relative to butt axis. At double-side welding passes are realized according to next order: first and second passes, then third, fourth and fifth passes.
EFFECT: enlarged manufacturing possibilities of method due to increased limit thickness of welded parts.
3 cl, 5 dwg
FIELD: machine engineering, possibly gas-shield electric arc welding by means of non-consumable electrode.
SUBSTANCE: method comprises steps of alternatively feeding several gases or their mixtures by pulses; at each next pulse feed using gases (gas mixtures) having ionization potentials different in comparison with those of gases or gas mixtures of previous pulse feed; periodically changing electric arc gap simultaneously with gas feed pulses; setting basic voltage of electric arc equal to optimal voltage in medium of gas or gas mixture with minimum ionization potential; setting difference between maximum and minimum voltage values of arc at periods of previous and next pulse feed of gases or gas mixtures in range 1 - 7 V.
EFFECT: enhanced quality of welded joints, possibility for adjusting fusion depth.
1 tbl, 1 ex
FIELD: gas-shield welding process with use of non-consumable electrode, namely torches for such welding.
SUBSTANCE: torch includes body of collet chuck holder. Said body has cylindrical surface near its working end and it is welded to electrically conducting gas conduit. Collet chuck is mounted in body for securing non-consumable electrode. Nozzle has cylindrical surface passing to cone surface and then again passing to cylindrical surface near its working end. Asbestos-cement insulator is arranged on surface of body of collet chuck holder; brass sleeve is put onto said insulator. Insulator is fixed to body by means of pressure ring-splitter having cylindrical surface passing to cone surface with radial openings.
EFFECT: possibility for making small-size torch for welding butts of metallic structures in hard-to-reach places of installation zone.
FIELD: plastic working of metals, namely processes for forming butt welded seams on tubes at making tube studs of U-shaped tube bundles using effect of localized hot plastic deforming of welded seam and near-seam zones.
SUBSTANCE: method comprises steps of preliminarily working tube ends by expanding them from cylinder to cylinder; assembling tubes with use of mandrel and placing intermediate member of additive material between joined end surfaces of end portions of tubes sized by expansion and end surfaces of step ring. Welded seams are formed by argon-arc welding due to melting material of intermediate member at its both sides adjacent to tube ends. The intermediate member is heated up and it is subjected to hot radial squeezing while concentrating its initial deformation in surface layers according to position of ring steps, welded seams and near-seam zones on mandrel for providing size of their outer diameter equal to initial outer diameter of tubes.
EFFECT: improved quality of welded seams.
FIELD: mechanical engineering; argon-arc welding.
SUBSTANCE: invention relates to methods of automatic argon-arc welding of austenitic steel pipes in manufacture of important constructions, such as high-pressure pipes used at nuclear power stations. Proposed method includes mechanical preparation of welding surface zone, veeing edges to miter of 3.0-3.5 mm and subsequent multiple-pass welding with nonconsumable negative electrode using filler wire. Welding edges are veed to miter of 2.7-3.0 mm. Welding at first pass is carried out with heat input of 0.35-0.55 MJ/m by impulse current. Welding at second pass is done with heat input of 0.6-0.86 MJ/m by impulse current at cross oscillations of electrode. Welding at third and subsequent passes is carried out with heat input of 0.62-1.16 MJ/m by steady current with cross oscillations of electrode.
EFFECT: increased capacity art welding and quality of weld joint owing to reduction of intercrystalline cracking of weld joint.
FIELD: mechanical engineering; welding.
SUBSTANCE: invention relates to design of torches for gas-shielded arc-welding by nonconsumable electrode. Proposed head of torch contains chuck with hole for electrode secured in body and gas fed channels, nozzle and partition arranged inside nozzle and formed by pack of gauzes. Gauze partition is made convex relative to welding arc flame. Head is furnished additionally with partition made of pack of gauzes arranged between chuck and gauze convex partition and made concave relative to flame of welding arc. Packs of gauzes are made of stainless steel of 3 to 5 layers. Gauze mesh is 0.3-0.5 mm.
EFFECT: provision of high quality of welding at relatively simple design.
5 cl, 2 dwg
FIELD: technological processes.
SUBSTANCE: invention concerns electric arc welding, particularly method of automatic argon arc welding of overlapping joints of steel pipes by non-melting electrode. The method involves preliminary pipe edge preparation and welding by tilted electrode with pipes rotating against electrode to form weld seam. Axial rotation speed of welded pipes is 0.1-0.8 rpm. Electrode is tilted in two planes: by 50-70 degrees against the article axis and by 60-85 degrees against weld seam plane.
EFFECT: improved quality of weld seams in overlapping joints of steel pipes, reduced hopping during rotation of long-length welded article, reduced cost of welded product.
3 cl, 3 dwg, 1 tbl