RU173886U1 - WELDING TORCH FOR ARG ARC WELDING WITH BUILT-IN AUTOMATIC FEED WIRE FEEDING - Google Patents

Abstract

The utility model relates to a torch for non-consumable electrode arc welding in a shielding gas medium with built-in automatic filler wire feeding and can be used in crowded working conditions and at heights when mounting welded structures. The torch contains a housing, a nozzle with a gas lens, a clamp collet, and a non-consumable electrode angle-adjustable filler wire feed tip, shielding gas supply tube, multi-position switch for switching on welding current, gas supply and filler wire locks, built-in automatic filler wire feeding device with a diameter of 0.6-1.0 mm, located in the housing. The device consists of a filler wire integrated in the box body of the filler wire, a roller mechanism consisting of a pressure roller and a feed with a speed-adjustable electric drive, a pressure roller force regulator, a feed speed controller located on the burner body, a Teflon feed channel to its tip and provides a pulling - pushing smooth movement of the filler wire into the weld pool. The technical result is to increase the operating parameters of the torch by providing the possibility its use for welding in hard-to-reach places with soft filler wires of small diameters and at the same time reducing the load on the welder's hand. 5 ill.

Description

The utility model is aimed at improving the welding torch as part of equipment for manual arc welding with a non-consumable electrode in an inert shielding gas such as argon.

The technologies for joining parts of metal products by welding are deeply developed and are constantly being improved as new requirements of various industries arise (Ovchinnikov V.V., Welder's Handbook. M., KnoRus, 2013, 272 p.).

Widespread welding with a consumable electrode in a gas environment under the international term MIG / MAG welding. The electrode is a welding wire with a diameter of 0.6 to 4 mm, wound from a reel of a special mechanism for feeding the welding wire, or from a coil compactly integrated into the welding torch. The arc and weld pool are protected from atmospheric air by an inert (MIG) or active (MAG) gas stream. The latter, in addition to protecting the joint, is involved in the formation of the weld as a chemically active element of the technological process. This type of welding is also called semi-automatic welding. Along with the above, manual arc welding with a non-consumable electrode, most often tungsten, in argon is widely used. In international terminology, this type of welding is referred to as TIG / WIG welding, in Russia the name "argon arc welding" or ADF has become fixed. The tungsten electrode is practically not consumed during the welding process; the arc burns between the electrode and the welded part, and the metal in the form of a filler rod is fed into the weld pool manually or automatically, using a special, free-standing massive block filler wire feeder. The arc, weld pool and electrode are protected by feeding from the nozzle of the torch into the welding zone of argon stored under pressure in a separate cylinder. The use of a particular type of welding depends on the responsibility of the requirements for accuracy and quality of the seam for specific structures made of certain materials. The governing documents (RD) of such industries as aerospace, chemical, oil and gas, oil and gas refining and some others prescribe the use of ADS for welding critical structures, technological piping, pressure vessels, etc. the following advantages of TIG welding over MIG / MAG welding: low heat input in the welding zone, without overheating of adjacent areas of the parts to be joined; excellent characteristics of the weld metal; lack of warping and deformation; the ability to connect parts from sheet materials; the ability to weld all types of non-ferrous alloys; the ability to weld the root of the seam; excellent appearance of the joint, practically requiring no additional processing; lack of metal spray in the melting zone.

In order to expand the market for products, most domestic and foreign manufacturers (LORCH, EWM. Migatronic, etc.) are following the path of universalization of their argon arc welding posts, equipping with massive large-sized equipment corresponding to the entire range of working welding currents from 10 to 600 A and filler wire diameters from 0.6 to 4.0 mm, which is fed into the weld pool both in manual and automatic mode at a distance of up to 3 m from a massive external feeder weighing up to 30 kg, equipped with 15 kg ammovoy reel filler wire. At the same time, the specificity of the complexity of the conditions and the distance from the post to the site of installation welding works, the range of welding currents corresponding to the thicknesses and grades of the parts to be welded, the uniformity, and sometimes even the impossibility, of supplying a thin and soft filler wire of non-ferrous metals with multiple bends of the feed channel to welding spots. So, aluminum is welded in the range of welding currents from 50 to 100A with a diameter of a soft aluminum filler wire of 0.6-0.8 mm and a complete reformatting of the set of equipment is required especially in difficult working conditions.

Significant disadvantages of equipment sets offered by manufacturers are its high cost, large weight and size parameters of equipment that do not allow argon-arc welding at the installation site of technological equipment, for example, at heights, in crowded spaces, technological piping of pipelines and shut-off and crane devices, inside and outside fuselages of aircraft, ships, various containers, tanks, etc.

The task to which the claimed utility model is directed is to significantly reduce the overall dimensions of the set of equipment for argon arc welding in the range of operating currents of 10 ÷ 250A, by eliminating the stand-alone filler wire feed unit and creating a welding torch with a built-in filler wire coil and its automatic uniform mechanism filing in the weld pool. Known torch for MIG / MAG welding of the brand QLBF-200 SPOOL WIRE GUN (http://weldingtoolsmaker.ru/2-1-wire-welding-spool-gun.html), intended mainly for welding aluminum using aluminum welding wire with a diameter 0.6 ÷ 0.8 mm as a melting electrode. Due to the softness of thin aluminum wire of small diameter, as well as other non-ferrous metals, smooth passage of the welding electrode through an elastic steel spiral channel at a distance of more than three meters from the external block device of the feed mechanism is very difficult, especially in difficult conditions for welding at the installation site technological equipment associated with numerous kinks of the spiral. To solve this problem, the ergonomic body of the pistol-type torch has a built-in box for accommodating the welding wire coil, an autonomous electric drive mechanism for feeding it into the weld pool. The torch can be used for welding with steel wire and flux cored wire with a diameter of up to 1 mm. The disadvantage of the burner is the inability to use it for argon-arc welding with a non-consumable electrode.

A well-known group of argon-arc welding torches with manual feed of a filler rod, grades of type ABITIG GRIP 26 (http://www.binzel-abicor.com/RU/eng/products/wig-tig/abitig-grip-9-26/). In the ergonomic torch body, made in the form of a handle-holder, a non-consumable tungsten electrode with a collector tip and a threaded connection is fixed rigidly with a collet clamp and a removable rear cap (electrode shield) to supply a laminar flow of protective gas - argon to the welding zone. The back cap protruding beyond the body of the burner is long enough to accommodate the entire length of the electrode. To work in crowded installation conditions, the burners are equipped with short electrodes and, accordingly, are equipped with short caps. A control button for turning on and off the welding current and shielding gas is built into the torch handle. The burner can be equipped with a quick-mount remote control unit for welding modes, in particular, welding current, as well as other control and monitoring functions. Depending on the magnitude of the operating current, the filler wire of a certain diameter is manually fed into the weld pool in the form of rods. The torch has a universal Euro-connector for connecting an elastic hose sleeve, which contains a welding cable, gas hose, control wires and control welding modes.

A small-sized torch for arc welding with a non-consumable electrode in a shielding gas medium is known (RF patent 2358846, December 6, 2007, C1, IPC V23K 9/167), intended for use in hard-to-reach places, mainly in the manufacture of aerospace products from aluminum, in which the burner body is formed an annular loop of the cooling water tube; a sleeve with a collet and nozzle connected to it is fixed on the lower side of this tube section, and a plug is installed on the upper side. Due to the forced water cooling of the burner, the technical solution allows for long-term welding in cramped installation conditions in a wide range of welding working currents.

Common disadvantages of these designs of torches with manual filler wire feed include: low productivity of the welder due to the possibility of manual feed only, high requirements for its qualification and high complexity of the manual argon-arc welding process.

Known argon-arc welding torch with a special device for automatic filler wire feed, WWT 45 SC-UD-KD grade (KEMPPI company catalog in Russian, TIG welding torches, p. 39, 2016. http://www.kemppi.com/ ru / "), FIG. 3, adopted as a prototype, which is most suitable for a similar torch design for manual argon-arc welding. The torch is additionally equipped with a tip for feeding the filler wire into the weld pool, which is fixed by an arm to the torch head, which allows you to adjust the angle of the tip to improve the employee's view of the weld zone. The welding station is additionally equipped with a separate block device for automatic filler wire feeding, weighing up to 35 kg, including a filler wire reel ∅0.6 ÷ 4.0 mm weighing up to 15 kg, or is built into the power supply unit. The wire is fed from an external device to the tip of the burner through a 4 m long channel made in the form of a spring steel spiral having an internal coating with a material with a low coefficient of friction, such as Teflon, which allows for minimal deformation of the wire and free movement while it moves along the feed channel to the burner and tip. The burner is equipped with an additional connector for mechanically securing the feed spiral, a remote control circuit for the wire feed speed and a connecting line for controlling the feed mechanism from an external device.

The disadvantages of the device include the difficulty of placing a bulky filler wire feed unit at a distance of no more than 4 meters from the place of welding and ensuring a uniform speed of its filing in the weld pool in difficult installation conditions associated with multiple bends of the feed channel.

The aim of the invention is to increase the operating parameters of a welding torch for argon-arc welding with the automatic feeding of a thin filler wire with a diameter of 0.6 ÷ 1.0 mm into the weld pool, primarily from soft non-ferrous metals, which allow welding to be performed in crowded conditions and at heights.

This goal is achieved by the fact that in the burner body for argon-arc welding, an automatic filler wire feeding unit is additionally integrated.

The technical result of the proposed solution is to increase the productivity of the welder by expanding the operational capabilities of the torch during argon-arc welding in crowded working space conditions and at heights, subject to the technical requirements for accuracy and quality of the joint for specific structures of non-ferrous metals, stainless and ferrous steels .

The specified technical result for the claimed object is a useful model by the fact that in a welding torch for argon-arc welding with external automatic filler wire feeding into the weld pool containing an ergonomic body in the form of a handle-holder with a removable electrode shield (cap) and a welding head, consisting of nozzles, clamping collet, non-consumable electrode, insulator, collector tubular tip located inside the gas pipe, which are mutually fixed to each other with a thread and a threaded adapter, the filler wire feed channel from an external device in the form of a steel spiral with an internal Teflon coating, paired with a tip fixed to the welding head by a swivel bracket, the housing is equipped with a switch for controlling and monitoring the welding modes, a remote control circuit for the filler wire feed speed from the external devices, a connector and an adapter for connecting a power welding cable, external control / control connecting lines and a trunk of inert gas combined in a single flexible sleeve, the peculiarity is that in the burner body, changed to the shape of a pistol type, an additional filler wire feed unit is built-in, consisting of a box with a freely rotating axis for installing and fixing on it a filler wire coil with a diameter of 0, 6 ÷ 1.0 mm and weighing up to 1 kg of aluminum and up to 1.5 kg of stainless steel, a pulling-pushing roller mechanism consisting of a pressure roller and a feed, with a speed-adjustable electric drive, a pressure regulator and a roller drive controller on a button feed rate controls located directly on the body surface.

The utility model is illustrated by illustrative materials: in FIG. 1 shows a drawing of a side view of the torch in an assembled form in section with a built-in spool of filler wire, an electric drive mechanism for feeding it into the weld pool and a detail drawing of the electrode head; in FIG. 2 is a sectional drawing of a top view of a running burner showing a filler wire feed path from a coil to a tip by a roller mechanism; in FIG. 3 presents a photograph of the burner - prototype assembled; in FIG. 4 is a photograph of an integrated spool of filler wire in a housing box and a roller feed mechanism thereof in a current pilot burner prototype; in FIG. Figure 4 shows the assembled photograph of the current prototype torch, in which the body of the welding torch for MIG / MAG welding of the QLBF-200 SPOOL WIRE GUN brand is used as a component.

The proposed torch for argon arc welding with built-in automatic feed of filler wire contains a plastic ergonomic anti-slip body 1 with a pistol grip; a welding electrode head, fixed in the housing, consisting of: a non-consumable tungsten electrode 2, a collet 3, a ceramic nozzle 4, an insulator 5, a collector tube tip 8 located inside the gas pipe 9, which are mutually fixed to each other by a snap holder 6, threaded adapter 7; a filler wire supply unit 19 to the weld pool, consisting of a box 10 with a freely rotating axis and a nut 11, for mounting and fixing a filament wire coil 12, a DC gear motor 13, a pull-push roller filler wire supply mechanism 19 made of pressure 14 and feed 15 rollers, force regulator 26 of pressure roller 14, Teflon channel 16 coupled to the tip 17, mounted on the electrode device with a swivel bracket 18, to adjust the angle of the tip filler wire 19. Inside the pistol grip located on the housing 1 there is a power terminal 20 for connecting the welding cable, control and control lines of the welding mode 21, as well as an adapter for attaching the inner protective gas supply pipe 23, which are connected through the connector (on Fig. 1 (not shown) and external connecting lines combined in a single flexible sleeve 22 are connected to a power source and an external gas line. In the handle of the housing 1 is a switch trigger type 24, which allows you to turn on / off the supply of welding current, protective gas and filler wire. The filler wire feed speed is set by the button of the speed controller 25, located on the side surface of the housing 1.

The operation of the device, the equipped torch for performing welding operations by argon arc welding, is as follows. We connect the welding torch through the connector (not shown in Fig. 1) to the welding cable of the power source, to the control and monitoring lines of the welding process, to the external shielding gas line, combined in a flexible hose sleeve 22. Depending on the type of welding work, grade and thickness We install the material to be welded on an external power source with a range of operating currents from 10 to 250 A and argon pressure. Depending on the selected welding current and the position of the seam, we set the filler wire feed rate and the bracket 18 with the potentiometer button 25 - the angle of the tip 17 to a position that allows the welder to organize a convenient overview of the tungsten electrode 2, filler wire 19 and the weld pool. For a certain diameter and material of the filler wire, we control the uniformity of the feed speed of the filler wire by changing the pressure of the pressure roller by the regulator 26.

We start the welding process by pressing the switch 24 to the "On" position and during the entire current welding cycle we keep it in this fixed state. Between the electrode 2 and the metal being welded, non-contact high-frequency excitation of the arc occurs with the simultaneous supply of argon through the internal line, through the nozzle 4, and the filler wire to the tip 17 in the welding zone. In the position of the switch 24 "On" is the supply voltage to the DC motor 13 of the electric drive, the rotational movement of which is transmitted to the axis of the feed roller 15. Due to the clamping force of the freely rotating roller 14, the roller mechanism provides pulling force from the coil 12 and pushing into the Teflon channel 16 for smooth movement of the filler wire through the tip 17 to the welding zone with the initially set speed by the regulator 25. In the process, as necessary, for example, when switching to a thin-wall деталь detail of the item to be welded or welding the root of the seam, use the rotary potentiometer 25 to adjust the rotation speed of the electric motor, and, as a consequence of the feed roller 15, thereby smoothly change the feed rate of the filler wire. At the end of the welding cycle, the switch 24 is released to the “Off” position, while the power to the electric drive is turned off and the wire feed is stopped. At the same time, at a falling welding current, we weld the crater at the final point of the seam, after which the welding current and argon supply cease.

In FIG. Figure 5 shows a photograph of a working prototype of a welding torch for argon-arc welding made by the author with automatic filler wire assembly. In FIG. 4 shows a coil located in an integrated box of a pistol-type burner body, and a roller mechanism consisting of pressure and feed rollers and a pressure roller force control device; on the side of the case is a button for regulating the filler wire feed speed. The overall dimensions of the burner in the assembled state are (length-height-width) 400 × 265 × 65 mm, the mass of the burner without the filler wire coil is 1.7 kg, the mass of the coil with aluminum wire with a diameter of 0.6 ÷ 0.8 mm is 1, 0 kg, with steel wire with a diameter of up to 1 mm - 1.5 kg, curb torch weight with a 4-meter welding cable up to 4.2 kg. In order to prepare the device for production, the product design was adapted as much as possible to use the entire line of tungsten electrodes, as well as to operate with an additional control unit and control the parameters of the arc, connecting arms and power supplies of most well-known manufacturers.

To compare the impact of the additional load on the welder’s arm due to the elastic deformations of the steel feed spiral during welding in difficult conditions of limited space of the workplace, the author developed a methodology for carrying out test dynamometric tests of the effects of pulling and shear loads on the handle of a pistol type burner. The handle of the burner was modeled with a wooden block of the appropriate size of the burner, clamped with a vise between two guides covered with foam padding, so as to provide a degree of freedom of movement in the direction of the measured force. The measuring organ of the dynamometer was attached to the handle of the burner - the place of application of the load on the welder's hand. The end of the feed spiral of the brand “Channel Guide 1.5 × 4.5 × 3000 mm blue (0.6-0.8) ABICOR BINZEL”, three meters long on one side, was fixed at the top of the bar, the location of the filler wire feed tip. In this case, sequentially, in each case, the spiral with little effort was extended to the entire length from the point of attachment to the bar, gradually bent 90 ° around one, two, three vertical pipes ∅20 mm, simulating sharp angles of rotation, and sequentially pinched at a distance of 0 , 3; 0.5; 1.0; 1.5 and 2.0 m from the last inflection point, simulating the often observed situation of multiple multidirectional inflection when assembling and welding in difficult conditions. After that, the jaws of the vise were parted, and load measurements were made. The physical model essentially consisted of the work of an elastic bow string from an inflection point to a pinch point, where the arising elastic forces are described by Hooke's law. In order to simulate various real working situations, the test conditions varied. So the simulator of the burner handle went up to a height of 0.5 m - a seated welder in the production of horizontal seams, 1.5 m - vertical and 2.0 m - ceiling, after which similar measurements were performed as described above. The measurement results showed that the greatest pulling and shear loads on the burner handle occur as the total length and maximum amplitude of the deformed sections of the steel spiral of the feed channel from the pinch point increase, and shear loads increase as you work at height. On average, additional loads on the burner handle were from 0.9 to 1.3 kg.

In the second, pessimistic version, they simulated options for twisting a feed spiral 4 m long around parts of the technological piping, in particular pipe products of different diameters of 100, 200 and 300 mm, during installation welding work at a height and additional loads on the torch handle were measured. On the one hand, from the side of the feeding device, the spiral was rigidly pinched, tightly screwed onto the pipe by one revolution, the remaining free end of the spiral was pulled out under a small load to its full length, fixed at the top of the bar - a simulator of the burner handle and rigidly clamped in a vise with foam rubber guides gaskets. At the same time, the measuring organ of the dynamometer was attached to the bar in the clamped state to the burner handle - the place of application of the load on the welder's arm, as described in the first test version. After that, the jaws of the vise were parted and a free block slid along the guides due to the elastic force according to Hooke's law. Measurements were carried out on each pipe selected by diameter with successive winding of a steel supply spiral for one, two and three full turns. In this case, the load on the welder's hand increased from 1.5 to 4.8 kg.

Also, the modes of external filler wire feeding along a steel spiral with an internal Teflon coating having a low coefficient of friction were simulated from a separately located feeding device of different manufacturers at distances up to 4 meters depending on the number of multidirectional bends of the spiral. With a double smooth multidirectional bend of 90 °, an uneven (jerky) spiral feed rate of ∅0.6 ÷ 1.0 mm was observed, up to a complete jam of the aluminum wire with a diameter of 0.6 mm. The tests carried out showed that the additional mass and weight load on the welder’s arm is a filler wire with a diameter up to 1.0 mm and a weight of up to 1.5 kg built into the burner during welding work with operating currents from 10 to 250 A under difficult installation conditions, limited spaces and at height, it is fully justified and appropriate. In some cases, when working with a soft filler wire of small diameters, its external supply becomes impossible without compromising the accuracy and quality of the seam. Therefore, the welder is forced to switch to argon-arc welding with manual filler wire, which significantly reduces productivity, welding quality, and requires a higher qualification of the worker. The automatic filler wire feed unit integrated in the burner provides a smooth, speed-adjustable, smooth and thin filler wire feed into the welding zone, regardless of the distance between the place of welding and the location of the welding station, the complexity of the installation conditions and allows you to quickly adjust its feed speed directly on the burner body.

Claims (1)

A welding torch for argon-arc welding, comprising a housing with a handle and a welding head, consisting of a nozzle, a clamp holder, a non-consumable electrode, an insulator, a collector tube located inside a gas pipe of a steel spiral channel with an internal Teflon coating filler wire mating with a tip that is mounted on the welding head by means of a swivel bracket, while the casing is equipped with a switch on and off the supply of welding current and shielding gas and is configured to supply filler wire, connect the power welding cable, external connecting control lines and inert gas line, combined in a single flexible sleeve, characterized in that it is equipped with a filler wire supply unit built into the body of the welding torch, which consists of a box with a freely rotating axis for installing and fixing the filler wire coil on it and pull-push its roller mechanism in the form of a pinch roller and the feed roller with the electric drive and a potentiometer for adjusting the feed rate of the filler wire, the regulator forces the pinch roller and located on the housing handle potentiometer button.

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