Inner hole submerged-arc horizontal welding equipment and welding method for butt welding seam of large-diameter pipe

Abstract

The invention discloses inner hole submerged-arc horizontal welding equipment and a welding method for large-diameter pipe butt welds, relates to the technical field of welding, and solves the problems of high cost, low welding efficiency and poor welding quality of large-diameter pipe inner hole welding equipment. The device comprises an adjustable supporting device, a servo motor and a welding device, the output end of the servo motor is downwards connected with the adjustable supporting device, and the upper end of the servo motor is connected with the welding device; the welding device comprises a supporting rod, a wire feeder is arranged at the upper end of the supporting rod, a welding flux hopper and a welding wire reel are arranged on the wire feeder, and a welding flux conveying pipe is arranged at the lower end of the welding flux hopper; a welding gun device is arranged at the lower end of the supporting rod and comprises a support and a bent welding gun, the support is movably connected with the supporting rod, and the bent welding gun is movably arranged on the support. The inner hole submerged-arc horizontal welding equipment is positioned and installed in the large-diameter pipe, the welding condition is observed in real time, welding parameters are adjusted, the welding efficiency is improved, and the welding quality is guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of welding, in particular to an inner hole submerged arc welding horizontal welding device and a welding method for a butt weld of a large-diameter pipe. Background Art

[0002] Generally, large-diameter butt welding adopts an external bevel form. However, for some special products, there are obstacles on the outer wall of the large-diameter butt weld, and welding cannot be performed from the outer wall of the pipe. In addition, welding inside the pipe has problems such as small welding space, high welding difficulty, and poor welding quality. Therefore, welding inside large-diameter pipes has become a shackle that restricts the development of the industry. In actual production, manual welding is usually used for welding the inner wall of large-diameter pipes. However, for some welds with smaller diameters, deeper welds, and higher preheating temperatures, manual welding is used because of the harsh working environment inside the pipe and limited welding space, resulting in a greater impact on the quality of manual welding due to human factors. Take the feed water inlet / outlet header and the extending pipe of the serpentine tube high-pressure heater as an example. Figure 1 As shown. Currently, manual welding is mainly used in the industry for this structure. Manual welding first uses argon arc welding to seal the bottom, single-sided welding to form the double sides, and arc welding to fill the cover. During the production process, the welder has a small operating space and obstructed vision. The welder needs to enter the workpiece to see the weld clearly. In addition, the material needs to be preheated to ≥150℃ before welding, and the interlayer temperature is 150-300℃, which leads to a harsh welding working environment, difficult welding operations, prone to welding defects, difficult rework, and low production efficiency.

[0003] Mechanical welding is mainly based on hot wire TIG welding, but this method has problems such as low welding efficiency, high equipment cost, and high assembly precision requirements. Based on the above, how to design a device and process method with low equipment cost, high welding efficiency and good welding quality has become the research goal of relevant enterprises. Summary of the invention

[0004] In order to solve the above-mentioned problems of high cost, low welding efficiency and poor welding quality of existing large-diameter pipe inner hole welding equipment, the present invention proposes an inner hole submerged arc welding horizontal welding equipment and welding method for large-diameter pipe butt welds.

[0005] The present invention proposes an inner hole submerged arc welding horizontal welding device for large-diameter pipe butt welds, which specifically includes an adjustable support device, a servo motor and a welding device, wherein the output end of the servo motor is downwardly connected to the adjustable support device, and the upper end of the servo motor is connected to the welding device; the welding device includes a support rod, a wire feeder is provided at the upper end of the support rod, a flux hopper and a welding wire reel are provided on the wire feeder, and a flux delivery pipe is provided at the lower end of the flux hopper; a welding gun device is provided at the lower end of the support rod, the welding gun device includes a bracket and a bending welding gun, the bracket and the support rod are movably connected, and the bending welding gun is movably arranged on the bracket.

[0006] Furthermore, the welding gun device also includes a horizontal slide plate, which is arranged at the lower end of the support rod, and the bracket is slidably arranged on the horizontal slide plate.

[0007] Furthermore, the welding gun device also includes a vertical slide plate, and the bracket is connected to the vertical slide plate and the horizontal slide plate.

[0008] Furthermore, an angle shaft is provided on the bracket, and the bending welding gun is connected to the bracket via the angle shaft.

[0009] Furthermore, a camera is arranged on the bending welding gun, a display screen is movably arranged on the bracket, and the camera and the display screen are connected.

[0010] Furthermore, a horizontal positioning device is arranged at the upper end of the servo motor, and the horizontal positioning device includes a plurality of claws and a level meter, the plurality of claws are movably arranged at the upper end of the servo motor, and the level meter is arranged at the upper end of the servo motor.

[0011] Furthermore, the adjustable support device includes a plurality of support feet and a support device body, the upper end of the support device body is connected to the output end of the servo motor; a plurality of support feet are movably arranged at the lower end of the support device body, a support plate is arranged at the end of the support feet, and a latch is detachably arranged on the support plate; a flux anti-falling net is hung at the lower end of the support device body.

[0012] Furthermore, it also includes a welding power supply and a controller, the welding power supply and the controller are connected, and the controller is connected to the adjustable support device, the servo motor and the welding device through the equipment cable; a collector is provided at the output end of the servo motor, and the output end is connected to the adjustable support device through the central axis.

[0013] A welding method using the above-mentioned inner hole submerged arc welding horizontal welding equipment for large-diameter pipe butt welds comprises the following steps:

[0014] S1. Assemble the pipes to be welded together. The weld groove at the joint is asymmetrical. Manual tungsten inert gas arc welding is used to weld the joint bottom to complete the first layer of welding. Then, submerged arc welding or arc welding is used to weld more than two layers. Before welding, the weld temperature must be ≥150℃, and the weld interlayer temperature must be controlled below 300℃ to complete the second and third layers of welding.

[0015] S2. Place the inner hole submerged arc welding horizontal welding equipment into the pipe to be welded, position it through the horizontal positioning device, fix the inner hole submerged arc welding horizontal welding equipment into the pipe to be welded through the adjustable support device, install a flux anti-falling net at the lower end of the inner hole submerged arc welding horizontal welding equipment; set a flux retaining ring on the lower bevel side of the weld; determine whether to teach the inner hole submerged arc welding horizontal welding equipment according to the ovality of the pipe to be welded;

[0016] S3. Set the welding parameters. Starting from the fourth layer, use the inner hole submerged arc welding horizontal welding equipment to fill the weld. The filling layer is multi-layer and multi-pass welding. The welding direction is from the lower side of the groove to the upper side, layer by layer. When welding the fourth and fifth layers, the welding current of the weld bead gradually decreases from the lower side of the groove to the upper side of the groove, and the welding speed of the weld bead gradually increases from the lower side of the groove to the upper side of the groove. Manual lane change welding is adopted. After the sixth layer, the welding parameters remain unchanged, and the lane change method is automatic lane change.

[0017] Furthermore, the flux retaining ring comprises retaining ring one and retaining ring two, one end of retaining ring one is connected to the lower bevel side of the weld, and the other end is connected to retaining ring two; retaining ring two is vertically arranged on retaining ring one.

[0018] The beneficial effects of the inner hole submerged arc welding horizontal welding equipment and welding method for large diameter pipe butt welds described in the present invention are:

[0019] (1) The present invention discloses an inner hole submerged arc welding horizontal welding device and a welding method for large diameter pipe butt welds, wherein the inner hole submerged arc welding horizontal welding device is positioned and fixed by means of a horizontal positioning device and an adjustable supporting device, and a level meter is used to ensure that the rotation center of the device is concentric with the center of the pipe, and that the distance between the gun head and the pipe wall remains unchanged when the bending welding gun rotates;

[0020] (2) The present invention describes a transverse submerged arc welding device and a welding method for inner hole butt welds of large-diameter pipes. By setting a horizontal slide and a vertical slide, the bending welding gun can adjust its position according to the welding situation during welding, realize the lane changing function, and improve the welding efficiency. At the same time, the flux is delivered to the welding position through the wire feeder, flux hopper, wire reel and flux delivery pipe to ensure stable welding. The welding process is observed in real time by a camera and displayed on a display screen to ensure the welding quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0022] In the attached picture:

[0023] Figure 1 It is a schematic diagram of welding of the feed water inlet / outlet header and the feed water inlet and outlet pipes of the serpentine tube high pressure heater in the prior art;

[0024] Figure 2 It is a structural schematic diagram of an inner hole submerged arc welding horizontal welding device for large diameter pipe butt welds according to the present invention;

[0025] Figure 3 It is a structural schematic diagram of a flux prevention net for inner hole submerged arc welding horizontal welding equipment used for large diameter pipe butt welds according to the present invention;

[0026] Figure 4 It is a structural schematic diagram of a horizontal positioning device for an inner hole submerged arc welding horizontal welding device for a large diameter pipe butt weld according to the present invention;

[0027] Figure 5 It is a bottom view of an adjustable support device for an inner hole submerged arc welding horizontal welding device for a large diameter pipe butt weld according to the present invention;

[0028] Figure 6 It is a structural schematic diagram of the weld groove at the butt joint of an inner hole submerged arc welding horizontal welding device for large diameter pipe butt welds according to the present invention;

[0029] Figure 7 It is a top view of a flux retaining ring of an inner hole submerged arc welding horizontal welding device for a large diameter pipe butt weld according to the present invention;

[0030] Figure 8 The invention discloses a horizontal welding device for inner hole submerged arc welding of large diameter pipe butt weld. Figure 7 Sectional view at AA in the middle;

[0031] Fig. 9 It is a schematic diagram of the welding sequence of the inner hole submerged arc welding horizontal welding equipment for large diameter pipe butt weld at the weld according to the present invention;

[0032] Fig.10 It is a schematic diagram of a small-slope weld structure of an inner hole submerged arc welding horizontal welding device and a welding method for a large-diameter pipe butt weld according to the present invention;

[0033] Fig.11 It is a schematic diagram of a large-slope weld structure of an inner hole submerged arc welding horizontal welding device and a welding method for a large-diameter pipe butt weld according to the present invention;

[0034] Fig.12 It is a schematic diagram of a large-slope layer-by-layer welding weld structure of an inner hole submerged arc welding horizontal welding device and a welding method for a large-diameter pipe butt weld according to the present invention;

[0035] Among them: 1-adjustable support device; 2-latch pin; 3-adjustment knob; 4-center axis; 5-collector; 6-servo motor; 7-lifting ear; 8-equipment cable; 9-horizontal slide; 10-vertical slide; 11-angle axis; 12-bending welding gun; 13-camera; 14-display screen; 15-flux hopper; 16-wire reel; 17-wire feeder; 18-flux delivery pipe; 19-welding power supply; 20-controller; 21-support rod; 22-horizontal positioning device; 23-flux anti-fall net hook; 24-wire mesh; 25-asbestos; 26-tube to be welded; 27-claw; 28-level; 29-support plate; 30-flux retaining ring; 31-retaining ring one; 32-retaining ring two. DETAILED DESCRIPTION

[0036] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0038] In the description of the invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the invention can be understood according to specific circumstances.

[0039] In addition, the technical features involved in different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0040] Specific implementation method 1: See Figure 1-Figure 12The embodiment is described in detail. The inner hole submerged arc welding horizontal welding equipment for large diameter pipe butt welds described in the embodiment specifically includes an adjustable support device 1, a servo motor 6 and a welding device. The output end of the servo motor 6 is connected to the adjustable support device 1 downward, and the upper end of the servo motor 6 is connected to the welding device; the output end of the servo motor 6 is provided with a collector 5, and the rotation signal of the output end of the servo motor 6 is obtained through the collector 5; the output end of the servo motor 6 is connected to the adjustable support device 1 through the central axis 4, and the adjustable support device 1 is provided with an adjustment knob 3, which is adjusted by adjusting the knob 3 adjusts the central axis 4 to extend and retract to change the distance between the servo motor 6 and the adjustable support device 1; the welding device includes a support rod 21, a wire feeder 17 is arranged on the upper end of the support rod 21, a flux hopper 15 and a welding wire reel 16 are arranged on the wire feeder 17, a flux conveying pipe 18 is arranged on the lower end of the flux hopper 15, and flux can be added to the weld at any time during the welding process; a welding gun device is arranged at the lower end of the support rod 21, and the welding gun device includes a bracket and a bending welding gun 12, the bracket and the support rod 21 are movably connected, and the bending welding gun 12 is movably arranged on the bracket.

[0041] The welding gun device further includes a horizontal slide plate 9 and a vertical slide plate 10, wherein the horizontal slide plate 9 is arranged at the lower end of the support rod 21, the bracket is slidably mounted on the vertical slide plate 10, and the vertical slide plate 10 is slidably mounted on the horizontal slide plate 9. Through the horizontal slide plate 9 and the vertical slide plate 10, the welding gun device can adjust its posture according to the welding process during the welding process and move in the horizontal direction and the vertical direction.

[0042] The bracket is provided with an angle shaft 11, and the end of the bending welding gun 12 is connected to the bracket through the angle shaft 11. The angle of the bending welding gun 12 is adjusted by driving the angle shaft 11 through a motor.

[0043] The bending welding gun 12 is provided with a camera 13 , and a display screen 14 is movably provided on the bracket. The camera 13 and the display screen 14 are connected, and the welding process is observed through the camera 13 and displayed on the display screen 14 .

[0044] The servo motor 6 is provided with a horizontal positioning device 22 at the upper end thereof, and the horizontal positioning device 22 includes a plurality of claws 27 and a level 28, wherein the plurality of claws 27 are movably provided at the upper end of the servo motor 6, and the level 28 is provided at the upper end of the servo motor 6; when the inner hole submerged arc welding horizontal welding equipment is set, the claws 27 are unfolded and clamped at the lower groove position of the weld, and the position of the level 28 is observed to make the rotation center of the equipment concentric with the center of the pipe 26 to be welded, such as Figure 4 shown.

[0045] The adjustable support device 1 includes a plurality of support legs and a support device body, the upper end of the support device body is connected to the output end of the servo motor 6 through the central shaft 4; the lower end of the support device body is movably provided with a plurality of support legs, the plurality of support legs are evenly arranged around the circumference, and a support plate 29 is provided at the end of the support leg, and a plug 2 is detachably provided on the support plate 29. For a large-diameter pipe with a hole on the inner wall, the inner-hole submerged arc welding horizontal welding device can be fixed to the inner wall of the pipe by the plug 2; for a large-diameter pipe without a hole on the inner wall, the inner-hole submerged arc welding horizontal welding device is fixed to the inner wall of the pipe by the support plate 29; the lower end of the support device body is provided with a plurality of flux anti-falling net hooks 23, and the flux anti-falling net is hung on the flux anti-falling net hooks 23. The flux anti-falling net includes a steel mesh 24, and asbestos 25 is laid on the steel mesh 24, and its function is to prevent flux or slag shell from entering the tube or the inner wall hole of the pipe, as well as some positions that are inconvenient to clean. When the flux in the flux prevention net reaches a certain amount, the internal flux and slag shell are sucked out by an external flux recovery device, and the flux recovery device needs to be equipped separately.

[0046] It also includes a welding power source 19 and a controller 20, the welding power source 19 and the controller 20 are connected, and the controller 20 is connected to the adjustable support device 1, the servo motor 6 and the welding device through the equipment cable 8.

[0047] A welding method using the above-mentioned inner hole submerged arc welding horizontal welding equipment for large-diameter pipe butt welds comprises the following steps:

[0048] S1. The pipe 26 to be welded is butt-jointed and assembled. The weld groove at the butt joint adopts an asymmetric groove. The up-groove angle α, the down-groove angle β, the up-groove root arc radius R1, and the down-groove root arc radius R2 are adjusted according to actual production. The specific parameters are shown in Table 1:

[0049] Table 1 Groove parameters

[0050]

[0051] The groove form can not only facilitate the observation of the weld, but also well support the flux, ensure the quality of horizontal welding, and greatly improve the welding qualification rate. In addition, the groove transition is smooth, the large angle is not easy to produce slag inclusion, the slag removal effect is good, and it is easier to achieve automatic welding;

[0052] Manual tungsten inert gas welding (M-GTAW) is used to weld the bottom of the joint, single-sided welding and double-sided forming are performed to ensure root penetration and complete the first layer of welding; preheating before welding is ≥100℃, the shielding gas used by the welding gun is single Ar, the purity of argon is ≥99.99%, and the shielding gas flow rate is 8-20L / min; the specific welding process parameters are shown in Table 2;

[0053] Then use submerged arc welding (SAW) or metal arc welding (SMAW) to weld two or more layers. When using submerged arc welding (SAW), fill welding is performed through fast and low current to prevent welding penetration caused by large heat input of submerged arc welding. Before welding, the weld temperature must be ≥150℃, and the weld interlayer temperature must be controlled below 300℃ to complete the second and third layer welding. The inner hole submerged arc welding wire can be φ1.2mm-2.5mm, and 1.6mm is preferred. The specific welding process parameters are shown in Table 2.

[0054] S2. Place the inner hole submerged arc welding horizontal welding equipment into the pipe to be welded 26, position it through the horizontal positioning device 22, fix the inner hole submerged arc welding horizontal welding equipment in the pipe to be welded 26 through the adjustable support device 1, and install the flux prevention net at the lower end of the inner hole submerged arc welding horizontal welding equipment; after the equipment is fixed, retract the claw 27, weld the flux retaining ring 30 on the lower bevel side of the weld to ensure that the flux retaining ring 30 is at the same horizontal height; after the equipment is installed, adjust the position of the bending welding gun 12, rotate the bending welding gun 12 under the simulated welding state, observe the position change of the welding gun head, determine the ovality of the pipe to be welded 2, and determine whether to teach the inner hole submerged arc welding horizontal welding equipment to a fixed point according to the ovality of the pipe to be welded 26. When the pipe ovality is ≤2%, no fixed point teaching is required, and welding can be carried out directly. When the pipe ovality is greater than 2%, the teaching point parameters can be set on the controller according to the actual production needs, so that the welding gun moves according to the set path, and fine-tuning can be performed through the remote control device during the movement;

[0055] After the ovality of the pipe is determined, align the bending welding gun 12 at the set position to ensure that the dry extension of the welding wire is 20-30mm. The welding direction can be selected clockwise or counterclockwise. After the arc is started, the flux at the position after welding can be pushed away to clear the coating, and the weld position and forming quality can be observed. The position and parameters can be adjusted during the welding process. After welding a circle, the above operation can be repeated, and automatic lane change can also be used to set the lane change parameters. When the flux at the groove is insufficient, the flux bucket above the equipment is used to transport and replenish the flux. When cleaning the flux at the groove, the flux recovery device can be used to recover the flux, and the flux can be reused after filtering and drying.

[0056] S3. Set welding parameters. Start filling the weld from the fourth layer using the inner hole submerged arc welding horizontal welding equipment. The filling layer is multi-layer and multi-pass welding. The welding direction is from the lower side of the groove to the upper side layer by layer. The welding sequence is as follows: Fig. 9 As shown in the figure, when the equipment rotates, the flux is easily pushed away, exposing the molten pool to the air, which is prone to quality problems. Therefore, the welding flux should preferably be a special flux for horizontal welding, which can better protect the molten pool and ensure the welding quality. When ordinary flux is used, the height of the flux pile at each position must be 10mm-25mm.

[0057] When welding the fourth and fifth layers, the welding current of the weld bead gradually decreases from the lower side of the groove to the upper side of the groove, and the welding speed of the weld bead gradually increases from the lower side of the groove to the upper side of the groove, that is, a larger welding current is selected on the lower side of the groove, and the welding speed should be slower than that on the upper side of the groove when welding the same layer; its purpose is to increase the thickness of the lower deposited metal, better support the molten metal of the next layer, and welding defects are not easy to occur under large parameters, which can not only ensure the welding quality, but also increase the amount of deposited metal per unit time and shorten the welding cycle; generally, manual lane change welding is used for the fourth to fifth layers. After arc starting, the flux at the rear position of the weld is pushed away, the coating is cleared, the weld position and forming quality are observed, and the front end welding quality is ensured; as the welding current gradually decreases from bottom to top, the amount of deposited metal per unit time decreases, and a step-type structure is formed at the weld. When the current decreases less, a step with a smaller slope will be formed, such as Fig.10 As shown in Figure 2, when the current decreases significantly, another step with a larger slope will be formed, such as Fig.11 As shown, Fig. 9 and Fig.10 1 to 5 are the layer-by-layer welding sequence, ①-③ are the pass-by-pass welding sequence;

[0058] When the pipe thickness is ≤60mm, the groove height is relatively low. The use of small slope steps can ensure that the upper layer of deposited metal will not flow down during welding, and quality problems are not likely to occur. In addition, the current reduction is small, the welding parameters are large, quality problems are not likely to occur, and the welding cycle is short. When the pipe thickness is greater than 60mm, the groove height is relatively high. In the later stage of welding the filling layer, due to the large groove gap and high weld temperature, the upper layer of deposited metal is likely to flow downward, causing quality problems. Therefore, the use of large slope steps can ensure welding quality;

[0059] After the sixth welding layer, the welding parameters remain unchanged, and the lane changing mode can be changed from manual lane changing to automatic lane changing. The lane changing parameters are set to Δx = 2-4mm, Δy = 2-4mm; for large slope steps, when the lower layer is welded to the edge of the groove, the welding is carried out layer by layer, such as Fig.12 When welding to a certain layer, the height of the flux retaining ring is not enough to support the welding. The flux retaining ring can be replaced to ensure that the flux can cover the molten pool and ensure the welding quality. When welding the surface layer, ensure the height of the flux and select the appropriate welding parameters according to the actual workpiece temperature.

[0060] Table 5 Welding process parameters

[0061]

[0062] In Table 2, the 2* and 3* welding layers are arc welding.

[0063] The flux retaining ring 30 includes retaining ring 1 31 and retaining ring 2 32. One end of retaining ring 1 31 is connected to the lower bevel side of the weld, and the other end is connected to retaining ring 2 32 by bolts; retaining ring 2 32 is vertically arranged on retaining ring 1 31; retaining ring 1 31 and retaining ring 2 32 are both composed of two semicircular rings or one full-circular ring. The width of retaining ring 1 31 is 10mm-100mm, and the height of retaining ring 2 32 is 40-70mm. It is replaced and adjusted according to the actual welding position. Retaining ring 2 32 is replaced once when the weld is welded to the 3 / 4 position. The flux retaining ring 30 is to better support the flux, ensure that the flux can cover the molten pool during welding, and ensure the welding quality.

[0064] The inner hole submerged arc welding horizontal welding equipment is suitable for welding materials such as carbon steel, alloy steel, stainless steel, aluminum alloy, copper alloy and the like.

[0065] To summarize the above implementation cases, the inner hole submerged arc welding horizontal welding equipment for large-diameter pipe butt welds described in the present invention is positioned and fixed by a horizontal positioning device 22 and an adjustable supporting device 1, and the level 28 is used to ensure that the rotation center of the equipment is concentric with the center of the pipe, and to ensure that the distance between the gun head and the pipe wall remains unchanged when the bent welding gun 12 rotates; the inner hole submerged arc welding horizontal welding equipment and welding method for large-diameter pipe butt welds described in the present invention, through the horizontal slide 9 and the vertical slide 10, the bent welding gun 12 can adjust the position according to the welding situation during welding, realize the lane changing function, and improve the welding efficiency; at the same time, the flux is transported to the welding position through the wire feeder 17, the flux hopper 15, the wire reel 16 and the flux delivery pipe 18 to ensure stable welding; the welding process is observed in real time by the camera 13 and displayed on the display screen 14 to ensure the welding quality.

[0066] The specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the invention. It can also be a reasonable combination of the features recorded in the above implementation methods. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A submerged arc welding horizontal welding equipment for inner hole of large diameter pipe butt weld, Features: The invention comprises an adjustable support device (1), a servo motor (6) and a welding device, wherein the output end of the servo motor (6) is connected downwardly to the adjustable support device (1), and the upper end of the servo motor (6) is connected to the welding device; the welding device comprises a support rod (21), a wire feeder (17) is arranged at the upper end of the support rod (21), a flux hopper (15) and a welding wire reel (16) are arranged on the wire feeder (17), and a flux conveying pipe (18) is arranged at the lower end of the flux hopper (15); a welding gun device is arranged at the lower end of the support rod (21), and the welding gun device comprises a bracket and a bent welding gun (12), the bracket and the support rod (21) are movably connected, and the bent welding gun (12) is movably arranged on the bracket.

2. The inner hole submerged arc welding horizontal welding equipment for large diameter pipe butt weld according to claim 1, Features: The welding gun device also includes a horizontal slide plate (9), which is arranged at the lower end of the support rod (21), and the bracket is slidably arranged on the horizontal slide plate (9).

3. The inner hole submerged arc welding horizontal welding equipment for large diameter pipe butt weld according to claim 2, Features: The welding gun device also includes a vertical slide plate (10), and the bracket is connected to the horizontal slide plate (9) via the vertical slide plate (10).

4. The inner hole submerged arc welding horizontal welding equipment for large diameter pipe butt weld according to claim 1, Features: An angle shaft (11) is arranged on the bracket, and a bending welding gun (12) is connected to the bracket via the angle shaft (11).

5. The inner hole submerged arc welding horizontal welding equipment for large diameter pipe butt weld according to claim 1, Features: The bending welding gun (12) is provided with a camera (13), a display screen (14) is movably provided on the bracket, and the camera (13) and the display screen (14) are connected.

6. The inner hole submerged arc welding horizontal welding equipment for large diameter pipe butt weld according to claim 1, Features: A horizontal positioning device (22) is arranged at the upper end of the servo motor (6). The horizontal positioning device (22) comprises a plurality of clamping claws (27) and a level (28). The plurality of clamping claws (27) are movably arranged at the upper end of the servo motor (6), and the level (28) is arranged at the upper end of the servo motor (6).

7. The inner hole submerged arc welding horizontal welding equipment for large diameter pipe butt weld according to claim 1, Features: The adjustable support device (1) comprises a plurality of support legs and a support device body, wherein the upper end of the support device body is connected to the output end of a servo motor (6); a plurality of support legs are movably provided at the lower end of the support device body, a support plate (29) is provided at the end of the support legs, and a latch (2) is detachably provided on the support plate (29); and a flux anti-falling net is hung at the lower end of the support device body.

8. The inner hole submerged arc welding horizontal welding equipment for large diameter pipe butt weld according to claim 7, Features: The device also comprises a welding power source (19) and a controller (20), wherein the welding power source (19) and the controller (20) are connected, and the controller (20) is connected to the adjustable support device (1), the servo motor (6) and the welding device via an equipment cable (8); a current collector (5) is provided at the output end of the servo motor (6), and the output end is connected to the adjustable support device (1) via a central shaft (4).

9. A welding method using the inner hole submerged arc welding horizontal welding equipment for large diameter pipe butt welds as claimed in claim 8, Features: The following steps are involved: S1, butt-joining the pipes (26) to be welded, using asymmetric bevels for the weld bevels at the butt joints, and performing bottom welding of the butt joints by manual tungsten inert gas arc welding to complete the first layer of welding; then, using submerged arc welding or arc welding to weld two or more layers, ensuring that the weld temperature is ≥150°C before welding, and the weld interlayer temperature is controlled below 300°C, to complete the second and third layer of welding; S2, placing the inner hole submerged arc welding horizontal welding equipment into the pipe to be welded (26), positioning it by means of a horizontal positioning device (22), fixing the inner hole submerged arc welding horizontal welding equipment in the pipe to be welded (26) by means of an adjustable supporting device (1), installing a flux prevention net at the lower end of the inner hole submerged arc welding horizontal welding equipment; setting a flux retaining ring (30) on the lower bevel side of the weld; and determining whether to perform teaching and positioning of the inner hole submerged arc welding horizontal welding equipment according to the ovality of the pipe to be welded (26); S3. Set the welding parameters. Starting from the fourth layer, use the inner hole submerged arc welding horizontal welding equipment to fill the weld. The filling layer is multi-layer and multi-pass welding. The welding direction is from the lower side of the groove to the upper side, layer by layer. When welding the fourth and fifth layers, the welding current of the weld bead gradually decreases from the lower side of the groove to the upper side of the groove, and the welding speed of the weld bead gradually increases from the lower side of the groove to the upper side of the groove. Manual lane change welding is adopted. After the sixth layer, the welding parameters remain unchanged, and the lane change method is automatic lane change.

10. The welding method according to claim 9, Features: The flux retaining ring (30) comprises retaining ring 1 (31) and retaining ring 2 (32); one end of retaining ring 1 (31) is connected to the lower bevel side of the weld, and the other end is connected to retaining ring 2 (32); retaining ring 2 (32) is vertically arranged on retaining ring 1 (31).

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