Large-diameter spiral seam submerged arc welding steel pipe rough forming pre-welding equipment

Abstract

The invention discloses large-diameter spiral seam submerged arc welding steel pipe rough forming pre-welding equipment, and relates to the field of steel belt spiral welding, the large-diameter spiral seam submerged arc welding steel pipe rough forming pre-welding equipment comprises two supports, the tops of the two supports are connected with vertical frames through a plurality of screws, and transmission rollers are rotationally connected between the two supports and between the two vertical frames; an equidistant adjusting and bending structure is arranged at the front parts of the two brackets, the equidistant adjusting and bending structure comprises three top rollers, a fixed frame is arranged at the front parts of the brackets, and a pressing roller is rotationally connected to one side, close to the bottom, of the fixed frame. Through the linkage design of the rotating discs of the equidistant adjustment bending structure, the motor is used for driving the arc-shaped grooves to synchronously rotate, accurate adjustment of the distance between the three top rollers is achieved, the structure can rapidly adapt to different steel pipe diameter standards, the stress uniformity during steel belt bending can be ensured through three-point positioning, and the bending efficiency is improved. Elliptical deformation or local stress concentration is effectively avoided, and the forming roundness and size consistency are guaranteed.

Description

Technical Field

[0001] The present invention relates to the field of spiral welding of steel strips, and particularly to a rough forming and pre-welding equipment for large-diameter spiral submerged arc welded steel pipes. Background Art

[0002] The spiral welding of steel strips into hollow cylindrical pipes is an efficient and economical manufacturing process for large-diameter pipe materials. With the surge in the demand for long-distance transportation of oil, natural gas, etc., traditional straight-seam welded pipes are difficult to meet the engineering requirements due to diameter limitations and low material utilization rate. The spiral welding technology significantly improves the dimensional flexibility and production efficiency of pipes by continuously spirally winding and welding steel strips. This process utilizes the characteristic of the spiral seam to disperse the circumferential stress, enhances the pressure-bearing capacity of the pipe body, and reduces the cutting loss of the plate. It is particularly suitable for manufacturing large-diameter and medium-wall-thickness transportation pipelines;

[0003] Chinese Patent with the publication number "CN118527880B" discloses a spiral steel pipe blank seam welding device, including a workbench and a vertical plate arranged on the workbench; a shaping device is also arranged on the vertical plate; a double-sided welding mechanism for welding the inner and outer walls of the pipe blank is arranged on the vertical plate; the double-sided welding mechanism includes two connecting plates that can approach and move away from each other, and a welding torch is arranged at the center of the connecting plate; two adjustment slots are arranged on each connecting plate, and an extrusion mechanism for narrowing the threaded seam of the pipe blank is arranged in each adjustment slot; each group of extrusion mechanisms includes an arc-shaped block that can move along the length direction and perpendicular to the length direction of the adjustment slot; a plurality of strip-shaped through slots are arranged on each arc-shaped block, and a C-shaped plate is slidably arranged in each strip-shaped through slot, and a pressing roller is rotatably arranged in each C-shaped plate;

[0004] The above patent can not only synchronously weld the inner and outer walls of the pipe blank, but also apply a certain driving force to the pipe blank, thereby improving the overall welding effect. However, it cannot dynamically adjust the distance between the top rollers to adapt to different pipe diameter standards, and lacks a pre-bending structure, resulting in stress concentration and forming deviation when the steel strip is directly bent. At the same time, the arc-shaped block and C-shaped plate of its extrusion mechanism can only linearly adjust the local pressure, making it difficult to provide progressive multi-point support and adaptive thickness compensation for the steel strip during the bending process of the spiral seam. The insufficient balance of heat input to the inner and outer walls of the pipe blank during welding is likely to cause weld deformation. Summary of the Invention

[0005] The main purpose of the present invention is to provide a rough forming and pre-welding equipment for large-diameter spiral submerged arc welded steel pipes, which can effectively solve the technical problems in the background art.

[0006] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0007] A large-diameter spiral submerged arc welded steel pipe rough forming and pre-welding equipment, including two brackets. The tops of the two brackets are both connected with vertical frames through a number of screws. There are transmission rollers rotatably connected between the two brackets and between the two vertical frames. An equidistant adjustment and bending structure is arranged at the front of the two brackets. The equidistant adjustment and bending structure includes three top rollers. A fixed frame is arranged at the front of the bracket. A pressure roller is rotatably connected to the bottom of one side of the fixed frame. Three sliding grooves are equidistantly arranged through the other side of one side of the fixed frame. Sliders are slidably connected inside the three sliding grooves. One side of each of the three sliders is fixedly connected with a moving block;

[0008] The three top rollers are respectively rotatably connected to the central positions of one sides of the three moving blocks. Two support rollers are rotatably connected to one side of each of the three moving blocks. A turntable is rotatably connected to the other side of the fixed frame. Three arc-shaped grooves are arranged through the side surface of the turntable. The other sides of the three sliders respectively penetrate through the three arc-shaped grooves and are fixedly connected with limiting blocks.

[0009] As a further scheme of the present invention, a connecting frame is fixedly connected at the center position of the turntable. A motor one is fixedly connected to the side surface of the fixed frame. The output shaft of the motor one penetrates through the other side of the fixed frame, and the output shaft of the motor one is fixedly connected with the connecting frame.

[0010] As a further scheme of the present invention, connecting sliding frames are fixedly connected to both the top and bottom of one side of the fixed frame where the pressure roller is located. Welding torches are fixedly connected to the closer surfaces of the two connecting sliding frames.

[0011] As a further scheme of the present invention, a screw rod is threadedly connected to the center position of the side surface of the turntable, and one end of the screw rod is also threadedly connected to the other side of the fixed frame.

[0012] As a further scheme of the present invention, a pre-bending structure is arranged between the bracket and the fixed frame. The pre-bending structure includes a pre-bending arc-shaped plate. Two pre-bending frames are arranged between the bracket and the fixed frame. A guard plate is fixedly connected between the two pre-bending frames. Lifting grooves are arranged on the closer surfaces of the two pre-bending frames. A lifting frame is arranged inside the lifting grooves. Lifting blocks are fixedly connected to the front and rear parts of the lifting frame. The lifting frame is slidably connected with the lifting grooves through the two lifting blocks. A lower roller is rotatably connected to the side surface of the lifting frame. Two cylinders are fixedly connected to the tops of the two pre-bending frames. The output shafts of the two cylinders penetrate through the lifting grooves, and the output shafts of the cylinders are fixedly connected to the top of the lifting frame. The pre-bending arc-shaped plate is fixedly connected between the two pre-bending frames, and the pre-bending frame is also fixedly connected to the front part of the guard plate.

[0013] As a further scheme of the present invention, a first pre-bending roller is rotatably connected to the top of the rear part of the pre-bending arc-shaped plate between the two pre-bending frames. A second pre-bending roller is rotatably connected to the top of the middle part of the pre-bending arc-shaped plate between the two pre-bending frames. A third pre-bending roller is rotatably connected to the top of the front part of the pre-bending arc-shaped plate between the two pre-bending frames.

[0014] As a further solution of the present invention, the first pre-bending roller, the second pre-bending roller and the third pre-bending roller are arc-shapedly distributed, and a pair of support legs are fixedly connected to both the front and rear parts of the fixed frame.

[0015] As a further solution of the present invention, two electrically driven self-rotating wheels are rotatably connected through the inside of the pre-bending frame on one side, a first belt pulley is rotatably connected to the front part of each of the two lifting frames, a first belt is sleeved between the two first belt pulleys, a second motor is fixedly connected to the front part of the pre-bending frame on the other side, an output shaft of the second motor is fixedly connected to one end of the lower roller on the side, and the other ends of the two lower rollers are respectively fixedly connected to the two first belt pulleys.

[0016] As a further solution of the present invention, an equidistant support structure is arranged on the side surface of the fixed frame. The equidistant support structure includes four support rollers, two vertical plates are arranged on the side surface of the fixed frame, two pairs of rotating plates are rotatably connected to the tops of the two vertical plates, the two pairs of rotating plates are fixedly connected to each other, the support rollers are rotatably connected between a pair of rotating plates, a connecting rod is fixedly connected between each pair of rotating plates and near the bottom, extension blocks are fixedly connected to the side surfaces of the two rotating plates on one side, a second belt pulley is rotatably connected to one side of each of the extension block and the vertical plate, a second belt is sleeved between the two second belt pulleys, a fixed connection frame is fixedly connected to one side of the vertical plate, a motor is fixedly connected to the side surface of the fixed connection frame, an output shaft of the motor is fixedly connected to the second belt pulley near the bottom, the two support rollers in the same direction are fixedly connected to each other, one end of the support roller on one side is fixedly connected to the second belt pulley near the top, a third belt pulley is rotatably connected to the other side and near the top of the rear vertical plate, a third belt pulley is also rotatably connected to the other side and near the bottom of the front vertical plate, a third belt is sleeved between the two third belt pulleys, a gear is rotatably connected to the other side and near the top of the front vertical plate, and a gear is also fixedly connected to the side surface of the third belt pulley near the front, the two gears are meshed with each other, a fixed connection bracket is fixedly connected to the side surface of the front vertical plate, and a third motor is fixedly connected to the side surface of the fixed connection bracket, and an output shaft of the third motor is fixedly connected to the gear near the top.

[0017] As a further solution of the present invention, four pairs of fixed connection blocks are fixedly connected to the mutually approaching surfaces of the two vertical plates, a hydraulic rod is rotatably connected between each pair of fixed connection blocks, an output shaft of the hydraulic rod is rotatably connected to the connecting rod, the side surface of the rotating plate on the rear side of one side is fixedly connected to the third belt pulley at the rear, and the side surface of the rotating plate on the front side of one side is fixedly connected to the gear near the top.

[0018] The beneficial effects of the present invention are as follows:

[0019] Through the turntable linkage design of the equidistant adjustable bending structure, the motor is used to drive the arc groove to rotate synchronously, realizing the precise adjustment of the distance between the three top rollers. This structure can not only quickly adapt to different steel pipe diameter standards, but also ensure the uniform stress during the bending of the steel strip through three-point positioning, effectively avoiding oval deformation or local stress concentration, and ensuring the roundness and dimensional consistency of the formed shape;

[0020] Through the pre-bending structure, the collaborative design of the stepped pre-bending roller group and the liftable lower roller is adopted, and the pre-bending arc plate is used to guide the progressive bending of the steel strip, significantly reducing the energy consumption and the risk of metal fatigue in the subsequent main bending. The height of the lower roller is dynamically adjusted by the cylinder, which can be compatible with steel strips of different thicknesses, avoiding problems such as slipping or positioning deviation caused by thickness differences, and improving the process robustness;

[0021] The symmetrical layout of the inner and outer welding torches on the connecting sliding frame realizes the synchronous welding of the inner and outer walls of the spiral weld. This design eliminates the cumulative effect of thermal deformation in traditional single-sided welding, shortens the welding cycle, and at the same time forms a dense weld bead through the mutual thermal influence of the double-sided molten pools, greatly improving the weld strength and airtightness;

[0022] The equidistant support structure realizes the closed-loop adjustment of the distance between the support rollers through the gear-belt linkage and the hydraulic rod locking mechanism. The rotation of the support rollers driven by the motor can assist the spiral feeding of the steel pipe, and the reverse gear group driven by the motor ensures the symmetrical retraction and extension of the support roller group, providing uniform radial support force while adapting to different pipe diameters, and avoiding ovalization or surface scratches of the pipe body;

[0023] The pre-bending section uses a pulley-belt synchronous drive for the lower roller to ensure the synchronism and speed stability of the steel strip transmission. The articulated design of the hydraulic rod and the rotating plate in the support section forms a self-locking support structure, maintaining rigid support during dynamic adjustment. The mechanical decoupling between modules is realized through the fixed connection frame and the sliding groove, reducing vibration transmission and ensuring the stability of long-term operation. Description of the Drawings

[0024] Figure 1 It is a schematic diagram of the overall structure of a large-diameter spiral submerged arc welded steel pipe rough forming and pre-welding equipment of the present invention;

[0025] Figure 2 It is a display diagram of the equidistant adjustable bending structure of a large-diameter spiral submerged arc welded steel pipe rough forming and pre-welding equipment of the present invention;

[0026] Figure 3 It is a split display diagram of the equidistant adjustable bending structure of a large-diameter spiral submerged arc welded steel pipe rough forming and pre-welding equipment of the present invention;

[0027] Figure 4 It is a split display diagram of the equidistant adjustable bending structure of a large-diameter spiral submerged arc welded steel pipe rough forming and pre-welding equipment of the present invention from the side view;

[0028] Figure 5 This is a display diagram of the pre-bending structure of a pre-welding equipment for rough forming of large-diameter spiral submerged arc welded steel pipes according to the present invention;

[0029] Figure 6 This is a split display diagram of the pre-bending structure of a pre-welding equipment for rough forming of large-diameter spiral submerged arc welded steel pipes according to the present invention;

[0030] Figure 7 This is a split display diagram of the side view of the guard plate and the pre-bending arc plate of a pre-welding equipment for rough forming of large-diameter spiral submerged arc welded steel pipes according to the present invention;

[0031] Figure 8 This is a display diagram of the equidistant support structure of a pre-welding equipment for rough forming of large-diameter spiral submerged arc welded steel pipes according to the present invention;

[0032] Figure 9 This is a split display diagram of the side view of the equidistant support structure of a pre-welding equipment for rough forming of large-diameter spiral submerged arc welded steel pipes according to the present invention.

[0033] In the figure: 1, support; 2, vertical frame; 3, driving roller; 4, equidistant adjustment and bending structure; 5, pre-bending structure; 6, equidistant support structure; 7, fixed frame; 8, pressure roller; 9, moving block; 10, top roller; 11, support roller; 12, chute; 13, connecting sliding frame; 14, welding torch; 15, motor 1; 16, support leg; 17, slider; 18, turntable; 19, arc groove; 20, limit block; 21, connecting frame; 22, pre-bending frame; 23, lifting groove; 24, lifting frame; 25, lower roller; 26, cylinder; 27, guard plate; 28, pre-bending arc plate; 29, first pre-bending roller; 30, second pre-bending roller; 31, third pre-bending roller; 32, electrically driven self-rotating wheel; 33, motor 2; 34, pulley 1; 35, belt 1; 36, lifting block; 37, vertical plate; 38, rotating plate; 39, support roller; 40, connecting rod; 41, extension block; 42, pulley 2; 43, belt 2; 44, fixed connection frame; 45, motor; 46, fixed connection block; 47, hydraulic rod; 48, pulley 3; 49, belt 3; 50, gear; 51, motor 3. Specific embodiments

[0034] In order to make the technical means, creative features, achieved purposes and effects of the present invention easy to understand, the present invention will be further described below in conjunction with specific embodiments.

[0035] Such as Figures 1-9As shown in the figure, a large-diameter spiral submerged arc welded steel pipe rough forming and pre-welding equipment includes two supports 1. The tops of the two supports 1 are both connected with vertical frames 2 by a number of screws. There are driving rollers 3 rotatably connected between the two supports 1 and between the two vertical frames 2. An equidistant adjustment and bending structure 4 is arranged at the front of the two supports 1. The equidistant adjustment and bending structure 4 includes three top rollers 10. A fixed frame 7 is arranged at the front of the support 1. A pressure roller 8 is rotatably connected to the bottom of one side of the fixed frame 7. Three sliding grooves 12 are equidistantly opened through the other side of one side of the fixed frame 7. Sliders 17 are slidably connected inside the three sliding grooves 12. A moving block 9 is fixedly connected to one side of each of the three sliders 17;

[0036] The three top rollers 10 are respectively rotatably connected to the central positions of one sides of the three moving blocks 9. Two support rollers 11 are rotatably connected to one side of each of the three moving blocks 9. A turntable 18 is rotatably connected to the other side of the fixed frame 7. Three arc-shaped grooves 19 are opened through the side surface of the turntable 18. The other sides of the three sliders 17 respectively pass through the three arc-shaped grooves 19 and are fixedly connected with limit blocks 20.

[0037] Place the steel strip to be spirally bent between the support 1 and the vertical frame 2, and drive the steel strip to move forward through the driving of the upper and lower groups of driving rollers 3. Then pass the steel strip through the bottom of the pressure roller 8, and then pass through the outside of the three top rollers 10 in sequence, and support the bottom of the steel strip by three pairs of support rollers 11. When the steel strip passes through the three top rollers 10, it can be bent into a near-circular shape. At this time, when moving the near-circular steel strip to one side, the steel strip can be spirally bent into a hollow cylinder. At this time, start two welding torches 14, and the two welding torches 14 weld the inner wall and the outer wall of the steel strip in the shape of a spiral hollow cylinder respectively, and weld the adjacent spiral gap parts of the steel strip to completely form a hollow cylinder;

[0038] Different production standards are different, and the diameters of the hollow cylinder steel strips to be formed are also different. At this time, use an external electric screwdriver to loosen the screw rod, and then start the first motor 15 to drive the connecting frame 21 and drive the turntable 18 to rotate, so as to drive the three arc-shaped grooves 19 to rotate synchronously along the center of the turntable 18, thereby forcing the three limit blocks 20 to move along the arc-shaped grooves 19. However, since the limit blocks 20 also move with the sliders 17 at the same time, the three limit blocks 20 together with the three sliders 17 will respectively slide close to each other along the three sliding grooves 12, thereby shortening the distance between the three moving blocks 9, thereby shortening the distance between the three top rollers 10, and thereby shortening the diameter of the hollow cylinder steel strip formed by the three top rollers 10. Since the distance between the three top rollers 10 is adjusted, not only can the standard shape of the formed hollow cylinder steel strip be ensured, but also the stability of the steel strip during bending can be ensured.

[0039] In this embodiment, a connecting frame 21 is fixedly connected to the center position of the turntable 18. A first motor 15 is fixedly connected to the side surface of the fixed frame 7. The output shaft of the first motor 15 penetrates through the other side of the fixed frame 7, and the output shaft of the first motor 15 is fixedly connected to the connecting frame 21.

[0040] In this embodiment, connecting sliding frames 13 are fixedly connected to both the top and bottom of the fixed frame 7 and located on one side of the pressure roller 8. Welding torches 14 are fixedly connected to the adjacent surfaces of the two connecting sliding frames 13;

[0041] The two welding torches 14 simultaneously weld the inner wall and the outer wall of the hollow cylindrical steel strip, thereby improving the welding quality and the welding speed.

[0042] In this embodiment, a screw rod is threadedly connected to the center position on the side surface of the turntable 18. One end of the screw rod is also threadedly connected to the other side of the fixed frame 7. The turntable 18 is fixed by the screw rod to prevent the turntable 18 from rotating during the adjustment of the bending diameter of the steel strip.

[0043] In this embodiment, a pre-bending structure 5 is provided between the support 1 and the fixed frame 7. The pre-bending structure 5 includes a pre-bending arc plate 28. Two pre-bending frames 22 are provided between the support 1 and the fixed frame 7. A guard plate 27 is fixedly connected between the two pre-bending frames 22. Lifting grooves 23 are formed on the adjacent surfaces of the two pre-bending frames 22. A lifting frame 24 is arranged inside the lifting groove 23. Lifting blocks 36 are fixedly connected to the front and rear parts of the lifting frame 24. The lifting frame 24 is slidably connected to the lifting groove 23 through the two lifting blocks 36. A lower roller 25 is rotatably connected to the side surface of the lifting frame 24. Two cylinders 26 are fixedly connected to the top of each of the two pre-bending frames 22. The output shafts of the two cylinders 26 penetrate through the lifting groove 23, and the output shafts of the cylinders 26 are fixedly connected to the top of the lifting frame 24. The pre-bending arc plate 28 is fixedly connected between the two pre-bending frames 22, and the pre-bending frame 22 is also fixedly connected to the front part of the guard plate 27;

[0044] Before the steel strip is bent by the three top rollers 10 and the pressure roller 8, pre-bending treatment is carried out through the pre-bending structure 5. Specifically, when the steel strip advances through the two groups of driving rollers 3, it passes between the two lower rollers 25 and the guard plate 27, and then the second motor 33 is started to drive the lower roller 25 on one side to rotate clockwise, and then through the two belt pulleys 34 and the belt 35, the other lower roller 25 is also driven to rotate clockwise synchronously. Thus, the two synchronously clockwise rotating lower rollers 25 drive the steel strip to move to the other side, so that when the steel strip is bent formally, it will approach the three top rollers 10 (this approach is not in the front-back direction but in the side direction). Therefore, when the steel strip is bent formally, the contact area between the steel strip and the three top rollers 10 is in the maximum state initially. This avoids the situation that the steel strip falls off during bending;

[0045] After the steel strip moves to one side, it will contact the two electrically driven self-rotating rollers 32. At this time, the two electrically driven self-rotating rollers 32 rotate synchronously, driving the steel strip to move forward. During the forward movement of the steel strip, it will be squeezed by the first pre-bending roller 29 first, and then along the pre-bending arc plate 28, it will be squeezed and bent by the second pre-bending roller 30 and the third pre-bending roller 31 respectively. Therefore, after the steel strip separates from the pre-bending arc plate 28, it can directly face the bottom of the pressure roller 8 and is located between the two connecting sliding frames 13, avoiding manual secondary positioning of the steel strip, so that the steel strip can face the bottom of the pressure roller 8;

[0046] At the same time, since the steel strip is preliminarily bent in advance, when the steel strip is bent by the pressure roller 8 and the three top rollers 10, not only the force required for bending is reduced, but also the bending efficiency is improved;

[0047] The cylinder 26 can drive the lifting frame 24 to move up and down along the lifting groove 23, thereby driving the lower roller 25 to move up and down, adjusting the distance between the lower roller 25 and the guard plate 27, so as to adapt to the thickness of different steel strips, so that the lower roller 25 can contact and drive the top of different steel strips.

[0048] In this embodiment, a first pre-bending roller 29 is rotatably connected to the rear top of the pre-bending arc plate 28 between the two pre-bending frames 22, a second pre-bending roller 30 is rotatably connected to the middle top of the pre-bending arc plate 28 between the two pre-bending frames 22, and a third pre-bending roller 31 is rotatably connected to the front top of the pre-bending arc plate 28 between the two pre-bending frames 22.

[0049] In this embodiment, the first pre-bending roller 29, the second pre-bending roller 30 and the third pre-bending roller 31 are distributed in an arc shape, and a pair of support legs 16 are fixedly connected to the front and rear of the fixed frame 7.

[0050] In this embodiment, two electrically driven self-rotating rollers 32 are rotatably connected through the inside of the pre-bending frame 22 on one side. A pulley one 34 is rotatably connected to the front of each of the two lifting frames 24. A belt one 35 is sleeved between the two pulleys one 34. A motor two 33 is fixedly connected to the front of the pre-bending frame 22 on the other side. The output shaft of the motor two 33 is fixedly connected to one end of the lower roller 25 on one side. The other ends of the two lower rollers 25 are respectively fixedly connected to the two pulleys one 34.

[0051] In this embodiment, an equidistant support structure 6 is provided on the side of the fixing frame 7. The equidistant support structure 6 includes four support rollers 39. Two vertical plates 37 are provided on the side of the fixing frame 7. Two pairs of rotating plates 38 are rotatably connected to the tops of the two vertical plates 37. The two pairs of rotating plates 38 are fixedly connected to each other. The support roller 39 is rotatably connected between a pair of rotating plates 38. A connecting rod 40 is fixedly connected between each pair of rotating plates 38 and near the bottom. Extension blocks 41 are fixedly connected to the sides of the two rotating plates 38 on one side. A second pulley 42 is rotatably connected to one side of the extension block 41 and one side of the vertical plate 37. A second belt 43 is sleeved between the two second pulleys 42. A fixed connection frame 44 is fixedly connected to one side of the vertical plate 37. A motor 45 is fixedly connected to the side of the fixed connection frame 44. The output shaft of the motor 45 is fixedly connected to the second pulley 42 near the bottom. The two support rollers 39 in the same direction are fixedly connected to each other. One end of the support roller 39 on one side is fixedly connected to the second pulley 42 near the top. A third pulley 48 is rotatably connected to the other side near the top of the rear vertical plate 37. A third pulley 48 is also rotatably connected to the other side near the bottom of the front vertical plate 37. A third belt 49 is sleeved between the two third pulleys 48. A gear 50 is rotatably connected to the other side near the top of the front vertical plate 37. And a gear 50 is also fixedly connected to the side of the front third pulley 48. The two gears 50 are meshed with each other. A fixed connection frame is fixedly connected to the side of the front vertical plate 37. A third motor 51 is fixedly connected to the side of the fixed connection frame. The output shaft of the third motor 51 is fixedly connected to the gear 50 near the top.

[0052] When the steel strip passes through the three top rollers 10 and the pressure roller 8 completely, it will be located between the tops of the two support rollers 39. At this time, start the motor 45, and drive the support roller 39 to rotate through the second pulley 42 and the second belt 43, so as to drive the hollow cylindrical steel strip to move towards the side.

[0053] Start the third motor 51, drive the front rotating plate 38 to rotate through the two meshing gears 50, and the bottom gear 50 rotates, which will drive the front third pulley 48 to rotate, and drive the rear third pulley 48 to rotate through the third belt 49, so as to drive the rear rotating plate 38 to rotate. Since the rotation directions of the two gears 50 are opposite, the rotation directions of the two groups of rotating plates 38 are opposite, so that the two rotating plates 38 rotate towards each other, thereby shortening the distance between the two groups of support rollers 39, so as to adapt to hollow cylindrical steel strips of different diameters.

[0054] In this embodiment, four pairs of fixed connection blocks 46 are fixedly connected to the mutually adjacent surfaces of the two vertical plates 37. A hydraulic rod 47 is rotatably connected between each pair of fixed connection blocks 46. The output shaft of the hydraulic rod 47 is rotatably connected to the connecting rod 40. The side of the rear rotating plate 38 on one side is fixedly connected to the rear third pulley 48. The side of the front rotating plate 38 on one side is fixedly connected to the gear 50 near the top.

[0055] When the turntable 38 rotates, it will drive the connecting rod 40 to move together, causing the position of the connecting rod 40 to change compared to its initial state. Furthermore, it will drive the output shaft of the hydraulic rod 37 to move, forcing the hydraulic rod 47 to rotate along with it, and its output shaft will also contract. When the turntable 38 stops rotating, the hydraulic rod 47 will exert an upward supporting force on the turntable 38 through the connecting rod 40, thus ensuring the stability of the turntable 38 together with the supporting roller 39.

[0056] It should be noted that the present invention is a large-diameter spiral submerged arc welded steel pipe rough forming and pre-welding equipment. When in use, the steel strip to be spirally bent is placed between the support 1 and the vertical frame 2, and is driven forward by the transmission of the upper and lower two groups of driving rollers 3. Then, the steel strip passes through the bottom of the pressure roller 8, and then passes through the outside of the three top rollers 10 in sequence, and the bottom of the steel strip is supported by three pairs of supporting rollers 11. When the steel strip passes through the three top rollers 10, it can be bent into a near-circular shape. At this time, by moving the near-circular steel strip to one side, the steel strip can be spirally bent into a hollow cylinder. At this time, start the two welding torches 14, and the two welding torches 14 respectively weld the inner wall and the outer wall of the steel strip in the shape of a spiral hollow cylinder, weld the adjacent spiral gap parts of the steel strip, and make it completely form a hollow cylinder;

[0057] Different production standards are different, and the diameters of the hollow cylinder steel strips to be formed are also different. At this time, use an external electric screwdriver to loosen the screw rod, and then start the first motor 15 to drive the connecting frame 21 and drive the turntable 18 to rotate, thereby driving the three arc grooves 19 to rotate synchronously along the center of the turntable 18, forcing the three limit blocks 20 to move along the arc grooves 19. However, since the limit blocks 20 also move with the sliders 17 at the same time, the three limit blocks 20 together with the three sliders 17 will slide closer to each other along the three sliding grooves 12 respectively, thereby shortening the distance between the three moving blocks 9, shortening the distance between the three top rollers 10, and shortening the diameter of the hollow cylinder steel strip formed by the three top rollers 10. Since the distance between the three top rollers 10 is adjusted, not only can the standard shape of the formed hollow cylinder steel strip be ensured, but also the stability of the steel strip during bending can be ensured;

[0058] The two welding torches 14 weld the inner wall and the outer wall of the hollow cylinder steel strip simultaneously, so the welding quality and welding speed are improved;

[0059] Before the steel strip is bent by the three top rollers 10 and the pressure roller 8, pre-bending treatment is carried out through the pre-bending structure 5. Specifically, when the steel strip advances through the two groups of driving rollers 3, it will pass between the two lower rollers 25 and the guard plate 27, and then the second motor 33 is started to drive the lower roller 25 on one side to rotate clockwise, and then through the two first pulleys 34 and the first belt 35, the other lower roller 25 is also driven to rotate clockwise synchronously, so that the steel strip is driven to move to the other side by the two lower rollers 25 rotating clockwise synchronously, so that when the steel strip is bent formally, it will be close to the three top rollers 10 (this closeness is not in the front-back direction, but in the side direction). Therefore, when the steel strip is bent formally, the contact area between the steel strip and the three top rollers 10 is in the maximum state initially, avoiding the situation that the steel strip falls off during bending;

[0060] After the steel strip moves to one side, it will contact the two electrically driven self-rotating wheels 32. At this time, the two electrically driven self-rotating wheels 32 rotate synchronously, thus driving the steel strip to move forward. During the forward movement of the steel strip, it will be squeezed by the first pre-bending roller 29 first, and then along the pre-bending arc plate 28, it will be squeezed and bent by the second pre-bending roller 30 and the third pre-bending roller 31 respectively. Therefore, after the steel strip separates from the pre-bending arc plate 28, it can directly face the bottom of the pressure roller 8 and is located between the two connecting sliding frames 13, avoiding manual secondary positioning of the steel strip, so that the steel strip can face the bottom of the pressure roller 8;

[0061] At the same time, due to the preliminary bending of the steel strip in advance, when the steel strip is bent by the pressure roller 8 and the three top rollers 10, not only the force required for bending is reduced, but also the bending efficiency is improved;

[0062] The cylinder 26 can drive the lifting frame 24 to move up and down along the lifting groove 23, so as to drive the lower roller 25 to move up and down, adjust the distance between the lower roller 25 and the guard plate 27, so as to adapt to the thickness of different steel strips, so that the lower roller 25 can contact and drive the top of different steel strips;

[0063] When the steel strip has been completely bent by the three top rollers 10 and the pressure roller 8, it will be located between the tops of the two support rollers 39. At this time, the motor 45 is started, and the support rollers 39 are driven to rotate through the second pulley 42 and the second belt 43, so as to drive the hollow cylindrical steel strip to move towards the side;

[0064] The starting motor three 51 drives the front rotating plate 38 to rotate through two meshing gears 50. When the bottom gear 50 rotates, it drives the front pulley three 48 to rotate, and through the belt three 49, it drives the rear pulley three 48 to rotate, thus driving the rear rotating plate 38 to rotate. Since the two gears 50 rotate in opposite directions, the two groups of rotating plates 38 rotate in opposite directions, causing the two rotating plates 38 to rotate towards each other, thereby shortening the distance between the two groups of supporting rollers 39, so as to adapt to hollow cylindrical steel belts of different diameters.

[0065] When the rotating plate 38 rotates, it drives the connecting rod 40 to move together, causing the position of the connecting rod 40 to change compared to its initial state. Furthermore, it drives the output shaft of the hydraulic rod 37 to move, forcing the hydraulic rod 47 to rotate along with it, and its output shaft also undergoes a contraction movement. When the rotating plate 38 stops rotating, the hydraulic rod 47 exerts an upward supporting force on the rotating plate 38 through the connecting rod 40, thus ensuring the stability of the rotating plate 38 together with the supporting roller 39.

[0066] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. The above embodiments and the descriptions in the specification only illustrate the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed.

Claims

1. A rough forming and pre-welding equipment for large-diameter spiral submerged arc welded steel pipes, comprising two brackets (1), and vertical frames (2) are connected to the tops of the two brackets (1) through a plurality of screws. It is characterized in that: There are transmission rollers (3) rotatably connected between two brackets (1) and between two vertical frames (2). An equidistant adjustment and bending structure (4) is provided at the front of the two brackets (1). The equidistant adjustment and bending structure (4) includes three top rollers (10). A fixed frame (7) is provided at the front of the bracket (1). A pressure roller (8) is rotatably connected to the bottom of one side of the fixed frame (7). Three sliding grooves (12) are equidistantly opened through the other side of one side of the fixed frame (7). Sliders (17) are slidably connected inside the three sliding grooves (12). A moving block (9) is fixedly connected to one side of each of the three sliders (17). The three top rollers (10) are respectively rotatably connected to the central positions of one sides of the three moving blocks (9). Two support rollers (11) are rotatably connected to one side of each of the three moving blocks (9). A turntable (18) is rotatably connected to the other side of the fixed frame (7). Three arc-shaped grooves (19) are opened through the side surface of the turntable (18). The other sides of the three sliders (17) respectively penetrate through the three arc-shaped grooves (19) and are fixedly connected with limiting blocks (20). Connecting sliding frames (13) are fixedly connected to the top and bottom of one side of the fixed frame (7) and on the side where the pressure roller (8) is located. Welding torches (14) are fixedly connected to the adjacent surfaces of the two connecting sliding frames (13).

2. The rough forming and pre-welding equipment for large-diameter spiral submerged arc welded steel pipes according to claim 1, characterized in that: A connecting frame (21) is fixedly connected to the center position of the turntable (18). A motor one (15) is fixedly connected to the side surface of the fixed frame (7).

3. The rough forming and pre-welding equipment for large-diameter spiral submerged arc welded steel pipes according to claim 2, characterized in that: The output shaft of the motor one (15) penetrates through the other side of the fixed frame (7), and the output shaft of the motor one (15) is fixedly connected with the connecting frame (21).

4. The rough forming and pre-welding equipment for large-diameter spiral submerged arc welded steel pipes according to claim 1, characterized in that: A screw rod is threadedly connected to the center position of the side surface of the turntable (18), and one end of the screw rod is also threadedly connected to the other side of the fixed frame (7).

5. The rough forming and pre-welding equipment for large-diameter spiral submerged arc welded steel pipes according to claim 1, wherein: A pre-bending structure (5) is provided between the bracket (1) and the fixed frame (7). The pre-bending structure (5) includes a pre-bending arc-shaped plate (28). Two pre-bending frames (22) are provided between the bracket (1) and the fixed frame (7). A protective plate (27) is fixedly connected between the two pre-bending frames (22). Lifting grooves (23) are opened on the adjacent surfaces of the two pre-bending frames (22). A lifting frame (24) is arranged inside the lifting grooves (23). Lifting blocks (36) are fixedly connected to the front and rear parts of the lifting frame (24). The lifting frame (24) is slidably connected to the lifting grooves (23) through the two lifting blocks (36). A lower roller (25) is rotatably connected to the side surface of the lifting frame (24). Two cylinders (26) are fixedly connected to the tops of the two pre-bending frames (22). The output shafts of the two cylinders (26) penetrate through the lifting grooves (23), and the output shafts of the cylinders (26) are fixedly connected to the top of the lifting frame (24). The pre-bending arc-shaped plate (28) is fixedly connected between the two pre-bending frames (22), and the pre-bending frame (22) is also fixedly connected to the front part of the protective plate (27).

6. The rough forming and pre-welding equipment for large-diameter spiral submerged arc welded steel pipes according to claim 5, characterized in that: A first pre-bending roller (29) is rotatably connected between the two pre-bending frames (22) and at the rear top of the pre-bending arc plate (28), a second pre-bending roller (30) is rotatably connected between the two pre-bending frames (22) and at the middle top of the pre-bending arc plate (28), and a third pre-bending roller (31) is rotatably connected between the two pre-bending frames (22) and at the front top of the pre-bending arc plate (28).

7. The rough forming and pre-welding equipment for large-diameter spiral submerged arc welded steel pipes according to claim 6, characterized in that: The first pre-bending roller (29), the second pre-bending roller (30) and the third pre-bending roller (31) are arc-shapedly distributed, and a pair of support legs (16) are fixedly connected to the front and rear of the fixed frame (7).

8. The rough forming and pre-welding equipment for large-diameter spiral submerged arc welded steel pipes according to claim 5, characterized in that: Two electric drive self-rotating wheels (32) are rotatably connected through the inside of the pre-bending frame (22) on one side, a first belt pulley (34) is rotatably connected to the front of each of the two lifting frames (24), a first belt (35) is sleeved between the two first belt pulleys (34), a second motor (33) is fixedly connected to the front of the pre-bending frame (22) on the other side, an output shaft of the second motor (33) is fixedly connected to one end of the lower roller (25) on one side, and the other ends of the two lower rollers (25) are respectively fixedly connected to the two first belt pulleys (34).

9. A rough forming and pre-welding equipment for large-diameter spiral submerged arc welded steel pipes according to claim 1, characterized in that: An equidistant support structure (6) is arranged on the side of the fixed frame (7), the equidistant support structure (6) includes four support rollers (39), two vertical plates (37) are arranged on the side of the fixed frame (7), two pairs of rotating plates (38) are rotatably connected to the tops of the two vertical plates (37), the two pairs of rotating plates (38) are fixedly connected to each other, the support rollers (39) are rotatably connected between a pair of rotating plates (38), a connecting rod (40) is fixedly connected between each pair of rotating plates (38) and near the bottom, extension blocks (41) are fixedly connected to the sides of the two rotating plates (38) on one side, a second belt pulley (42) is rotatably connected to one side of each of the extension block (41) and the vertical plate (37), a second belt (43) is sleeved between the two second belt pulleys (42), a fixed connection frame (44) is fixedly connected to one side of the vertical plate (37), a motor (45) is fixedly connected to the side of the fixed connection frame (44), an output shaft of the motor (45) is fixedly connected to the second belt pulley (42) near the bottom, the two support rollers (39) in the same direction are fixedly connected to each other, one end of the support roller (39) on one side is fixedly connected to the second belt pulley (42) near the top, a third belt pulley (48) is rotatably connected to the other side near the top of the rear vertical plate (37), a third belt pulley (48) is also rotatably connected to the other side near the bottom of the front vertical plate (37), a third belt (49) is sleeved between the two third belt pulleys (48), a gear (50) is rotatably connected to the other side near the top of the front vertical plate (37), and a gear (50) is also fixedly connected to the side of the front third belt pulley (48), the two gears (50) are meshed with each other, a fixed connection bracket is fixedly connected to the side of the front vertical plate (37), and a third motor (51) is fixedly connected to the side of the fixed connection bracket, and an output shaft of the third motor (51) is fixedly connected to the gear (50) near the top.

10. The rough forming and pre-welding equipment for large-diameter spiral submerged arc welded steel pipes according to claim 9, characterized in that: On the mutually approaching surfaces of the two vertical plates (37), four pairs of fixing blocks (46) are fixedly connected. A hydraulic rod (47) is rotatably connected between each pair of fixing blocks (46). The output shaft of the hydraulic rod (47) is rotatably connected to the connecting rod (40). The side surface of the rearward rotating plate (38) is fixedly connected to the rearward pulley three (48). The side surface of the forward rotating plate (38) is fixedly connected to the top gear (50).

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