RU2172661C1 - Device for arc multi-electrode welding - Google Patents

Abstract

FIELD: welding of angle joints of rectangular pipes. SUBSTANCE: the protective chamber accommodates several units of electrodes successively fastened on the clamps in common electrode holders. The units are electrically interconnected and fastened in cantilever on a clip insulated from the article for turning relative to cantilevers. The quantity of electrodes equals the quantity of joints of parts welded by the head. The quantity of electrodes in each unit is selected depending on the necessary length of the weld and the diameter of the point welded by one electrode per cycle. Located opposite the working ends of the electrodes are the ends of the solenoid cores fastened in the common holders connected to their power source via the program current switching device. EFFECT: enhanced capacity and simplified construction of equipment due to the absence of necessity to insulate the electrodes and units, as well as due to the absence of current leads to each electrode. 4 dwg

Description

 The invention relates to mechanical engineering and can be used, for example, for welding corner joints of rectangular pipes.

 There is a known method of arc welding (Ide Eijo, Fujimura Haroshi, Inoue Hironori, application N 63313674, Japan, 12/21/88, RJ 1.63.263P, 1990), according to which welding is performed by several melting electrodes with the formation of a common bath. The wire of each electrode is fed using an individual mechanism through a copper current supply tube. All tubes are bundled 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, before reaching the lower end of the current leads, shielding gas is supplied through the same tube. The entire tube assembly is placed in a nozzle surrounding them to form a gas stream that protects the weld pool from air. As a result, high productivity of the welding process is ensured, weld formation is improved, and shielding gas consumption is reduced. But the known 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 of multi-electrode arc welding (Kazakov Yu.V., Akimov A.V., USSR author's certificate N 1779504 dated 02.01.91), according to which mainly thin-sheet structures are welded with several electrodes. Welding voltage is applied simultaneously to all the electrodes, and before starting welding, the transverse magnetic field at the arc gaps is turned on. Welding is carried out according to a given program. To do this, the arc is sequentially ignited on the next electrode by turning off the transverse magnetic field on it. When welding according to this method, by using several electrodes electrically interconnected to each other and controlling the ignition of the arc by switching low-current circuits, the design of the welding head is simplified and energy is saved. However, this method when welding short seams, for example trusses from rectangular pipes, requires the movement of the electrodes after welding of each seam to a new section of the parts and re-setting the electrodes to the joint. This increases the complexity of the welding process.

 A known method and device for arc welding (Henry Thomas Leibey, patent N 3114829, USA from 12/17/1963), which is adopted as a prototype. According to this method, welding is carried out by several non-consumable electrodes, which are arranged sequentially along the welded joint. The electrodes are alternately included in the welding circuit. Each electrode performs welding of one point, which overlap each other. To protect the metal of the weld pool from the front and back of the joint, a chamber filled with protective gas is used. This method allows to increase the productivity of the welding process, but the device for its implementation has a complex structure due to the fact that a separate power cable must be connected to each electrode, the electrodes must be isolated from each other, and the device must be equipped with a welding current power switch. In addition, when welding short seams of frame structures, for example, from rectangular pipes, the prototype device, like the previous analogue, will require frequent rearrangement of the electrodes and repeated adjustment to a new joint of parts, which will increase the complexity of the welding process.

 The technical problem solved by the proposed device is to simplify the equipment and increase the productivity of the welding process.

где L - длина шва, выполняемого данным блоком, мм;
d_m - диаметр точки, свариваемой одним электродом за цикл его работы.The proposed device contains a protective chamber with a welding head installed in it, containing several series-mounted non-consumable electrodes fixed in electrode holders and connected to a common power source of the welding arc. Unlike the prototype, the welding head consists of several blocks of welding electrodes that are electrically connected to each other. The blocks are mounted on a clamp isolated from the item to be welded using consoles with the possibility of rotation relative to them and equipped with brackets for attaching the electrodes in common electrode holders. The number of blocks is chosen equal to the number of seams in the joint of parts welded by a head. The number of electrodes in each block is determined from the expression

where L is the length of the seam performed by this unit, mm;
d _m is the diameter of the point welded by one electrode per cycle of its operation.

 Each electrode is equipped with a solenoid, the end of the core of which is located against the working end of the electrode. Solenoids are fixed in common holders and connected to their power source through a software current switching device.

 Such a combination of new features with the known ones will make it possible to increase the productivity of the process of welding structures with a large number of short welded joints due to the fact that it will be possible to mechanize this process. In turn, this feature will be provided by simplifying the design of the device due to the fact that current leads to each electrode become unnecessary and there is no need to switch high-current circuits.

 The device is illustrated by drawings. In FIG. 1 shows a diagram of a device; in FIG. 2 is a front view; in FIG. 3 is a top view; FIG. 4 is a left view of the welding head.

где L - длина шва, выполняемого данным блоком, мм;
d_m - диаметр точки, свариваемой одним электродом за один цикл его работы.The proposed device comprises a protective chamber 1 with a welding head installed in it, consisting of several blocks 2 of consecutively installed non-consumable welding electrodes 13 connected to a common power source 3 of the welding arc. The blocks 2 of the electrodes 13 are electrically connected to each other and mounted on a collar 5 isolated from the welded product with the help of consoles 6,7,8 and 9 with the possibility of rotation relative to them. The electrodes 13 are fixed in common electrode holders 11 using brackets 10. Each electrode 13 is equipped with a solenoid 12, and the end face of the core of each solenoid 12 is located opposite the working end of its electrode 13. Solenoids 12 are fixed in common solenoid holders 14 and connected to their power source 15 through device 4 software switching current. The number of blocks 2 is chosen equal to the number of seams in the joint of the parts of the welded assembly 16, welded by a head. The number of electrodes 13 in each block 2 is determined from the expression

where L is the length of the seam performed by this unit, mm;
d _m is the diameter of the point welded by one electrode in one cycle of its operation.

где L - длина шва, выполняемого данным блоком, мм;
d_m - диаметр точки, свариваемой одним электродом за один цикл его работы.The proposed device operates as follows. On the weldable assembly 16, for example, a T-junction of two pipes of rectangular cross-section, install and fix a clamp 5 isolated from the assembly 16. On it using consoles 6,7,8 and 9 fix blocks 2 of consecutively installed non-consumable, for example tungsten, electrodes 13. The number of blocks 2 in the welding head is chosen equal to the number of seams at the junction of the parts of the welded assembly 16. The number of electrodes 13 in each block 2 is determined from the expression

where L is the length of the seam performed by this unit, mm;
d _m is the diameter of the point welded by one electrode in one cycle of its operation.

 The choice of the coefficient limit in the denominator of this expression is due to the fact that when it is less than 0.4, there will be no overlap of the points welded by each of the electrodes 13 on the reverse side of the seam, and if the value is more than 0.8, the points will be almost completely remelted, which will reduce productivity process. In both cases, the quality of the welds will decrease.

 In blocks 2, the electrodes 13 are fixed in common electrode holders 11 using brackets 10 and connected to a common power source 3 of the welding arc, the other pole of which is connected to the welded assembly 16. All electrodes 13 are equipped with solenoids 12, the ends of the cores of which are located against the working ends of the electrodes 13. The solenoids 12 are fixed in the common solenoid holders 14 and are connected to a separate power source through the device 4 software switching current. Blocks 2 are mounted on consoles 6,7,8 and 9 with the possibility of rotation relative to them, which allows you to install the electrodes 13 at an acute angle to the surfaces of the welded parts of the node 16 in the case of T-joints (Fig. 2) or at right angles to these surfaces in case of the butt joint (Fig. 4). A protective chamber 1 is installed on top of the welding head assembled from blocks 2, which can be used as any camera of known design, for example, a rigid chamber of two halves, equipped with seals in the connector and around the perimeter of the parts to be covered, fittings for supplying protective gas and outputting power and switching wires. Chamber 1 is filled, for example, by purging with a protective gas, which can be taken as argon. The voltage from the power source 3 of the welding arc is supplied simultaneously to all electrodes 13 of all blocks 2, electrically connected to each other. At the same time, a voltage from a power source 15 is supplied through a programmable current switching device 4 to all solenoids 12 that generate a magnetic field transverse to the axes of the electrodes 13, which prevents the ignition of welding arcs. The device is initialized before welding.

The welding process is started by breaking off the power circuit of one of the solenoids 12 using the programmable current switching device 4. The transverse magnetic field will stop against the working end of the corresponding electrode 13, a welding arc will be excited between the end of this electrode and the surface of the part to be welded 16, which will burn until until the voltage from the power supply 15 is applied to this solenoid 12 by the device 4. During the arc burning, a weld point with a diameter of d _{m is} formed under the electrode 13. Then, the device 4, according to the specified program, supplies voltage from the power source 15 to this solenoid 12 and turns it off on the other solenoid 12. The cycle will be repeated until a weld point is formed under the last of the electrodes 13 of each block 2. The points mutually overlap, forming continuous weld. Welding can be carried out without filler or with filler material pre-laid in the joint of parts. As the device 4 software switching current can be applied to any known switch, assembled, for example, from commercially available step finders. Such a switching device can provide any sequence of excitation of arcs from the electrodes 13, which will reduce the voltage in the welding unit 16.

 The proposed device in comparison with the prototype has a simpler design, because it does not require the connection of individual power wires to each electrode and does not need to isolate the electrodes 13 and blocks 2 from each other. Switching the ignition of the arcs on the electrodes 13 is carried out in low-current circuits of the solenoids 12, which simplifies the design of the device 4 switching current. In addition, with the help of the proposed device, one welder can conduct welding at several joints of parts of the welded assembly 16 at once, its function will only include installing blocks 2 of welding heads and protective chambers 1 on the welded joints of the parts, as well as removing them after welding. He can perform these operations at some joints of parts at a time when welding occurs at other joints. As a result, the productivity of the process will increase.

 Thus, the proposed device provides a technical effect and can be manufactured and applied using means known in the art. Therefore, the proposed device for multi-electrode arc welding has industrial applicability.

Claims (1)

A device for multi-electrode arc welding, containing a protective chamber with a welding head installed in it with several non-consumable electrodes sequentially fixed in the electrode holders, connected to a common power source of the welding arc, characterized in that the welding head consists of several blocks of welding electrodes connected electrically to each other, the blocks are mounted on a clamp isolated from the product being welded by means of consoles with the possibility of rotation relative to them and equipped with For mounting electrodes in common electrode holders, the number of blocks is chosen equal to the number of seams in the joint of parts welded by a head, and the number of electrodes in each block is determined from the expression

where L is the length of the seam made by this unit, mm;
d _m is the diameter of the point welded by one electrode per cycle of its operation,
moreover, each electrode is equipped with a solenoid, the end of the core of which is located against the working end of the electrodes, and the solenoids are fixed in common holders and connected to their power source through a software current switching device.

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