Device for submerged arc welding of inner seam of steel pipe

Abstract

The utility model discloses a submerged arc welding device for an inner seam of a steel pipe, which relates to the technical field of welding equipment and comprises a traction device and a support, a traction rod is arranged at the output end of the traction device, one end of the traction rod is connected with a machine head, a wire guide pipe is arranged on the machine head, and a wire guide wheel and a welding nozzle are arranged at one end of the machine head. A welding wire penetrates through the welding nozzle, the guide wheel and the wire guide pipe, the machine head is located at one end of the welding nozzle, a first supporting wheel and a second supporting wheel are arranged on the circumferences of the two sides of the welding nozzle, and a third supporting wheel is elastically arranged on the machine head and located on the angular bisector of the included angle of the first supporting wheel and the second supporting wheel. The action directions of the first supporting wheel, the second supporting wheel and the third supporting wheel are opposite; according to the automatic welding machine, the first supporting wheel, the second supporting wheel and the third supporting wheel are arranged, so that the distance between the welding nozzle and base metal is guaranteed, the rejection rate of the welding nozzle is effectively reduced, the welding cost is reduced, and the welding seam quality is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of welding equipment, in particular to a device for submerged arc welding of the inner seam of steel pipes. Background Art

[0002] Submerged arc welding (including submerged arc surfacing and electroslag surfacing, etc.) is a welding method in which the arc burns under a layer of flux. Its inherent advantages such as stable welding quality, high welding productivity, no arc light and very little smoke and dust make it the main welding method in the manufacture of important steel structures such as pressure vessels, pipe sections, and box-shaped beam columns. In recent years, although many new high-efficiency and high-quality welding methods have emerged successively, the application field of submerged arc welding has not been affected at all. From the perspective of the share of the deposited metal weight of various fusion welding methods, submerged arc welding accounts for about 10%, and it has not changed much over the years.

[0003] During the production of steel pipes, when the thickness of the steel plate is greater than 20 mm, a double V-groove needs to be opened at the joint of the steel pipe to ensure the welding quality of the steel pipe joint. However, when the diameter of the steel pipe is 800 - 1000 mm, at this time, the welder cannot normally enter the inside of the steel pipe for welding, and at this time, a device that can replace the welder to extend the welding torch into the inside of the steel pipe for welding is needed.

[0004] Therefore, the utility model patent with the publication number of CN 207606390 U and the publication date of July 13, 2018 discloses a submerged arc welding device for the inner wall of small-diameter steel pipes, including a support frame, a lifting and adjusting device, a transverse movement device, and a welding device; the support frame includes a base and a T-shaped column; the lifting and adjusting device includes a sliding seat and a chain block; the transverse movement device includes a cross beam and a transverse movement driving device; the welding device includes a welding head, a control box, a wire reel, a large flux box, a small flux box, an air compressor air pipe, and a weld observation device; the welding head and the small flux box are arranged at one end of the cross beam, the control box and the weld observation device are arranged on the sliding seat, the wire reel and the large flux box are arranged at the other end of the cross beam, the control box is electrically connected to the transverse movement driving device, the welding head, and the weld observation device respectively, the large flux box and the small flux box are connected through a communicating pipe, and the air compressor air pipe is connected to the communicating pipe;

[0005] In the structural design of this utility model, the wire reel and the flux box that occupy a large space are separated from the welding head and are respectively arranged at both ends of the cross beam, so that the space occupied by the welding head can be reduced, and it can better adapt to the inner diameter change of small-diameter steel pipes, with simple operation, low cost, and convenient use;

[0006] However, a problem has also emerged during the implementation of this patent: when the crossbeam extends into the steel pipe, at this time, there is only one support point for the crossbeam, which is the support frame. The welding torch located at the end of the crossbeam will exert a downward force on the front end of the crossbeam due to its own weight, causing the crossbeam to sag. The longer the crossbeam extends, the more obvious the sag at the end. At this time, the distance between the welding nozzle and the base material is closer. Since high temperature is generated during welding, it is easy to burn out the welding nozzle. Therefore, the scrapping rate of the welding nozzle will increase during the entire welding process. When replacing the welding nozzle and re-welding, an additional starting point will be added to the entire weld. The increase in the starting point will affect the quality of the entire weld and also increase the cost of steel pipe welding.

[0007] Therefore, there is an urgent need for a submerged arc welding device for the inner seam of steel pipes to ensure the distance between the welding nozzle and the base material, reduce the scrapping rate of the welding nozzle and the welding cost, and further ensure the quality of the weld. Utility Model Content

[0008] In view of the above technical problems, the present utility model provides a submerged arc welding device for the inner seam of steel pipes to solve the problems that the existing welding equipment cannot ensure the distance between the welding nozzle and the base material, thereby increasing the scrapping rate of the welding nozzle and the quality of the weld cannot be guaranteed.

[0009] The above technical objectives of the present utility model are achieved through the following technical solutions:

[0010] A submerged arc welding device for the inner seam of steel pipes includes a traction device and a bracket. The output end of the traction device is provided with a traction rod. One end of the traction rod is connected to a machine head. The machine head is provided with a wire guide tube. One end of the machine head is provided with a wire guide wheel and a welding nozzle. A welding wire is threaded through the welding nozzle, the wire guide wheel and the wire guide tube. The other end of the welding wire is connected to a submerged arc welding machine. The machine head is located at one end of the welding nozzle, and first support wheels and second support wheels are circumferentially arranged on both sides of the welding nozzle. A third support wheel is elastically arranged on the angular bisector of the included angle between the first support wheel and the second support wheel. The acting directions of the first support wheel, the second support wheel and the third support wheel are opposite;

[0011] At the other end of the machine head and at the center position of the welding nozzle, a fourth support wheel is rotatably arranged.

[0012] Further, the included angle between the first support wheel and the second support wheel is 120 degrees.

[0013] Further, the third support wheel includes a guide tube. An elastic member is arranged in the guide tube. A guide rod is sleeved in the guide tube. The guide rod is axially connected to the third support wheel.

[0014] Further, the fourth support wheel includes a wheel frame. A rotating bearing is arranged on the wheel frame. A rotating column is sleeved in the rotating bearing. One end of the rotating column is connected to the machine head.

[0015] Further, the thickness of the fourth support wheel is smaller than the groove width of the steel pipe.

[0016] Further, a plurality of guide rails are arranged on the bracket in a direction perpendicular to the axis of the steel pipe, and two sets of clamping units are symmetrically and slidably arranged on the guide rails, and the two sets of clamping units can move towards each other.

[0017] Further, the clamping unit includes a plurality of clamping blocks. One ends of the plurality of clamping blocks are connected together with a driving rod. A lead screw is arranged in the middle of the driving rod, and the threads on the lead screw are symmetrically arranged with the length center of the lead screw as the boundary.

[0018] Further, a handle is arranged at one end of the lead screw.

[0019] In summary, the beneficial technical effects of the present utility model are as follows:

[0020] (1) The first support wheel, the second support wheel and the third support wheel can play an upward supporting role for the machine head inside the steel pipe, preventing the machine head from sagging and reducing the distance between the welding torch and the base material, reducing the scrapping rate of the welding torch, effectively reducing the weld joints, ensuring that the entire weld can be welded without replacing the welding torch, thereby ensuring the quality of the weld. At the same time, the elastically arranged third support wheel can dynamically reduce the jumping amplitude of the machine head through elasticity, ensuring the stable progress of welding.

[0021] (2) By using the rotatably arranged fourth support wheel, it can be placed inside the groove of the steel pipe during welding and use the groove as the moving path, thereby ensuring the straightness of the weld and preventing welding deviation.

[0022] (3) By using the lead screw to drive the two clamping units to move towards each other, the distance between the two symmetrically arranged clamping blocks can be adjusted according to the diameter of the steel pipe, realizing the clamping and fixing of steel pipes with different diameters. Description of the Drawings

[0023] Figure 1 is a schematic diagram of the overall structure of the present utility model;

[0024] Figure 2 is a schematic diagram of the structure of the machine head;

[0025] Figure 3 is Figure 2 a schematic diagram from another angle;

[0026] Figure 4 is a schematic diagram of the structure of the third support wheel;

[0027] Figure 5 is a schematic diagram of the structure of the fourth support wheel;

[0028] Figure 6It is a schematic diagram of the use of the present utility model;

[0029] Figure 7 is Figure 6 a schematic diagram from another angle;

[0030] Figure 8 is Figure 7 an enlarged schematic diagram of part A of

[0031] Reference numerals: 1, tractor; 2, trolley; 3, ground rail; 4, bracket; 5, towing rod; 6, machine head; 7, wire guide tube; 8, wire guide wheel; 9, welding nozzle; 10, welding wire; 11, first support wheel; 12, second support wheel; 13, third support wheel; 14, fourth support wheel; 15, guide tube; 16, elastic member; 17, guide rod; 18, wheel frame; 19, rotating bearing; 20, rotating column; 21, guide rail; 22, clamping block; 23, connecting rod; 24, driving rod; 25, lead screw; 26, handle; 27, introduction part; 28, steel pipe; 29, bevel. Detailed implementation manners

[0032] The present utility model will be clearly and completely described below in conjunction with the embodiments.

[0033] It should be noted that all directional indications (such as up, down, left, right, front, back...) in the embodiments of the present utility model are only used to explain the relative position relationship and movement conditions between components in a specific posture (as shown in the drawings). If the specific posture changes, the directional indications will also change accordingly.

[0034] In the description of the embodiments, unless otherwise clearly specified and limited, terms such as "set" and "connected" 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 directly connected or connected through an intermediate medium, and it can also be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific situations.

[0035] See the attached Figures 1-5, shown is a device for submerged arc welding of internal seams of steel pipes, including a traction device and a bracket 4. The traction device includes a tractor 1 and a trolley 2. The bottom of the trolley 2 is provided with a ground rail 3. During welding, the trolley 2 is driven by a motor on the trolley 2 to move linearly along the ground rail 3. A traction rod 5 is provided on the tractor 1. One end of the traction rod 5 is connected to a welding head 6. The welding head 6 is of a cavity structure, which can reduce the weight of the entire welding head 6. A wire guiding tube 7 is provided along the length direction inside the welding head 6. At the same time, a plurality of wire guiding wheels 8 are provided at the end of the welding head 6 away from the traction rod 5 through a mounting plate. A welding nozzle 9 is provided at the bottom of the mounting plate. A welding wire 10 is passed through the welding nozzle 9, the wire guiding wheels 8 and the wire guiding tube 7. The other end of the welding wire 10 is provided with a submerged arc welding machine. During welding, the welding wire 10 extends out through the welding nozzle 9, and the end of the welding wire 10 maintains a distance of 5-8 mm from the base material. At the same time, the arc is initiated by the submerged arc welding machine to achieve welding. During welding, the flux is conveyed to the welding nozzle 9 through a pipeline and flows to the arc to achieve the purpose of submerged arc;

[0036] The welding head 6 is located at one end of the welding nozzle 9, and a first support wheel 11 and a second support wheel 12 are symmetrically provided on both sides of the welding nozzle 9. The included angle between the first support wheel 11 and the second support wheel 12 is 120 degrees. The first support wheel 11 and the second support wheel 12 can support the weight of the front end of the entire welding head 6, avoiding the sagging of the welding head 6 under the action of weight, ensuring the distance between the welding nozzle 9 and the base material, reducing the scrapping rate of the welding nozzle 9 during the welding process, reducing the welding cost, and at the same time reducing the replacement times of the welding nozzle 9 per unit length of the weld seam, avoiding multiple arc initiations and reducing the weld quality. At the same time, by maintaining the stability of the distance between the welding nozzle 9 and the base material, the arc length during welding can be further ensured to be stable, thereby improving the welding quality;

[0037] At the same time, a third support wheel 13 is provided at the top of the welding head 6 and on the angular bisector of the included angle between the first support wheel 11 and the second support wheel 12. The third support wheel 13 includes a guiding tube 15. An elastic member 16 is provided inside the guiding tube 15. The elastic member 16 is specifically a compression spring. At the same time, a guiding rod 17 is provided inside the guiding tube 15. One end of the guiding rod 17 is axially connected to the third support wheel 13. It can be seen that during welding, the third support wheel 13 uses the elastic member 16 to apply an elastically variable reaction force to the first support wheel 11 and the second support wheel 12. This structure can not only be applicable to welding of steel pipes 28 with different diameters, but also improve the stability of the welding head 6 through the elastic support force;

[0038] Meanwhile, at the other end of the machine head 6, a fourth support wheel 14 is provided. The fourth support wheel 14 includes a wheel frame 18. At the top of the wheel frame 18, a rotating bearing 19 is provided. A rotating column 20 is sleeved on the inner circle of the rotating bearing 19. One end of the rotating column 20 is connected to the machine head 6. At the same time, the fourth support wheel 14 is located at the central position of the welding torch 9, so as to ensure that the centers of the fourth support wheel 14 and the welding torch 9 are on the same straight line. Furthermore, the fourth support wheel 14 provides a guiding function for the movement of the entire machine head 6. Slope-shaped guiding parts 27 are provided on both sides of the fourth support wheel 14. During welding, the fourth support wheel 14 is placed in the groove 29 of the steel pipe 28, and the groove 29 serves as the movement path of the fourth support wheel 14. When the entire machine head 6 moves, it can move along the groove 29, thereby ensuring the straightness of the entire weld seam and avoiding welding deviation.

[0039] Furthermore, a plurality of guide rails 21 are arranged perpendicular to the axis direction of the steel pipe 28 on the support 4. Two groups of clamping units are symmetrically and slidably arranged on the guide rails 21. The clamping unit includes a plurality of clamping blocks 22 slidably arranged on the guide rails 21. One end of the clamping block 22 is provided with a connecting rod 23. A driving rod 24 is connected to a plurality of connecting rods 23 in the same direction. A lead screw 25 is in threaded cooperation with the middle part of the driving rod 24. The two ends of the lead screw 25 are rotatably arranged on the support 4, and a handle 26 for rotation is provided at one end of the lead screw 25. The threads on the lead screw 25 are symmetrically arranged with the center of the length of the lead screw 25 as the boundary. In this way, when in use, by rotating the lead screw 25, the two clamping units are synchronously driven to move towards each other along the guide rails 21, so that the distance between two mutually symmetrical clamping blocks 22 can be changed by the lead screw 25 when welding steel pipes 28 with different diameters.

[0040] It should be noted that in order to prevent the guide rod 17 from falling off the guide tube 15 under the action of the elastic member 16, the length of the entire elastic member 16 in the free state is less than the length of the guide tube 15, so as to ensure that a part of the length of the guide rod 17 is always inside the guide tube 15.

[0041] It should be noted that in order to ensure that the machine head 6 can move along the groove 29 during welding, when arranging the support 4, the entire support 4 is fixed to the ground through anchor bolts, and at the same time, it is necessary to ensure that the length axis of the entire support 4 is as collinear with the towing rod 5 as possible.

[0042] During welding, refer to the appendix Figures 6-8, first place the steel pipe 28 on the bracket 4. At the same time, drive the clamping units on both the left and right sides through the lead screw 25 to complete the clamping of the steel pipe 28. Meanwhile, place the groove 29 of the steel pipe 28 at the bottom, so as to ensure that the entire welding angle is in the flat and inclined welding state, which is conducive to ensuring the weld quality. Then place the entire welding head 6 inside the steel pipe 28 and place the fourth support wheel 14 inside the groove 29. Then drive the welding head 6 to pre-move along the groove 29 through the entire traction device. The purpose of pre-moving is to observe whether the welding nozzle 9 is directly above the groove 29, so as to avoid the problem of welding deviation during welding. Then push the welding head 6 to the farthest end of the steel pipe 28, start the arc welding by the submerged arc welding machine and flow the welding flux to the arc through the welding nozzle 9. At this time, provide traction for the entire welding head 6 through the trolley 2, so that the welding head 6 moves along the weld under the guiding action of the fourth support wheel 14 to achieve the purpose of welding.

[0043] The above is only the preferred specific implementation mode of the present invention, and does not limit the protection scope of the present invention accordingly. Therefore, all equivalent changes made according to the structure, shape and principle of the present invention shall be covered within the protection scope of the present invention.

Claims

1. A device for submerged arc welding of internal seams of steel pipes, comprising a traction device and a bracket (4). The output end of the traction device is provided with a traction rod (5). One end of the traction rod (5) is connected to a welding head (6). A wire guide tube (7) is provided on the welding head (6). One end of the welding head (6) is provided with a wire guide wheel (8) and a welding nozzle (9). A welding wire (10) is threaded through the welding nozzle (9), the wire guide wheel (8) and the wire guide tube (7). The other end of the welding wire (10) is connected to a submerged arc welding machine, and it is characterized in that: The head (6) is located at one end of the welding nozzle (9), and a first support wheel (11) and a second support wheel (12) are provided on the circumferences on both sides of the welding nozzle (9). The head (6) is elastically provided with a third support wheel (13) on the angular bisector of the included angle between the first support wheel (11) and the second support wheel (12), and the acting directions of the first support wheel (11), the second support wheel (12) and the third support wheel (13) are opposite; At the other end of the head (6) and at the central position of the welding nozzle (9), a fourth support wheel (14) is rotatably provided.

2. The device for submerged arc welding of the inner seam of a steel pipe according to claim 1, characterized in that: The included angle between the first support wheel (11) and the second support wheel (12) is 120 degrees.

3. The device for submerged arc welding of the inner seam of a steel pipe according to claim 1, characterized in that: The third support wheel (13) includes a guide tube (15), an elastic member (16) is provided in the guide tube (15), a guide rod (17) is sleeved in the guide tube (15), and the guide rod (17) is axially connected to the third support wheel (13).

4. A device for submerged arc welding of internal seams of steel pipes according to claim 1, characterized in that: The fourth support wheel (14) includes a wheel frame (18), a rotating bearing (19) is provided on the wheel frame (18), a rotating column (20) is sleeved in the rotating bearing (19), and one end of the rotating column (20) is connected to the head (6).

5. The device for submerged arc welding of the inner seam of a steel pipe according to claim 1, characterized in that: The thickness of the fourth support wheel (14) is less than the width of the groove (29) of the steel pipe (28).

6. The device for submerged arc welding of internal seams of steel pipes according to claim 1, characterized in that: A plurality of guide rails (21) are arranged on the bracket (4) perpendicular to the axis direction of the steel pipe (28), and two groups of clamping units are symmetrically slidably arranged on the guide rails (21), and the two groups of clamping units can move towards each other.

7. The device for submerged arc welding of the inner seam of a steel pipe according to claim 6, characterized in that: The clamping unit includes a plurality of clamping blocks (22), one ends of the plurality of clamping blocks (22) are connected together with a driving rod (24), a lead screw (25) is provided in the middle of the driving rod (24), and the threads on the lead screw (25) are symmetrically arranged with the length center of the lead screw (25) as the boundary.

8. The device for submerged arc welding of the inner seam of a steel pipe according to claim 7, characterized in that: One end of the lead screw (25) is provided with a handle (26).

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