A welding device for butt joining of circular tubes

Abstract

The present application relates to the technical field of wireless communication equipment, and discloses a welding device for pipe butt joint, especially its clamping mechanism, which comprises a movable base, sliding guide rails and two groups of pipe clamps arranged on the movable base, and the pipe clamps are driven to move by a servo motor and a first screw rod, the pipe clamps comprise V-shaped pipe racks, lifting clamping racks and the like, the lifting clamping racks are driven to rotate by the first gear and the rack, the lifting clamping racks are lowered, the V-shaped pipe racks with the first rotating rollers are used to clamp the pipe, the constant clamping force is maintained by the return springs, the pipe is clamped, then the pipe is close to butt joint, when the pipe cannot continue to close to butt joint, the first screw rod drives the related components to drive the first rotating rollers to rotate the pipe, the circumferential welding is facilitated, the loosening is prevented, and the butt tightness of the weld and the welding quality are ensured.

Description

Technical Field

[0001] This invention relates to the field of pipe welding equipment technology, and in particular to a welding device for butt welding of round pipes. Background Technology

[0002] In pipeline construction, arc welding of circular pipes is a common connection method. Traditional circular pipe welding equipment suffers from several technical defects: First, existing equipment requires three separate steps: pipe clamping, butt joint positioning, and weld alignment, resulting in a cumbersome and inefficient process. Second, conventional mechanical locking devices are prone to loosening during welding due to equipment vibration or external forces, leading to weld position misalignment and severely impacting weld quality. Third, existing equipment lacks an automatic compensation mechanism; it cannot automatically adjust when clamping force is insufficient, requiring manual intervention to re-clamp. More significantly, after butt jointing, traditional equipment requires an additional rotating mechanism for pipe rotation welding, increasing both equipment complexity and operational procedures. Furthermore, in existing technology, clamping force and rotation control are independent, making coordinated clamping and rotation difficult, leading to insufficient clamping force or uneven rotation during welding. These technical defects severely restrict the automation level and weld quality stability of pipeline welding. Summary of the Invention

[0003] The technical problem to be solved by the present invention is that the existing technology has the disadvantage of having many operation steps in the traditional pipe arc welding clamping device. To this end, we propose a welding device for the butt welding of round pipes.

[0004] To achieve the above objectives, this application adopts the following technical solution: a welding device for butt welding of round pipes, comprising: a movable base, a welding robot disposed on one side of the movable base, a sliding guide rail fixedly connected above the movable base, two sets of round pipe clamps disposed on the sliding guide rail, a slider disposed at the bottom of the round pipe clamps, the slider being slidably connected to the sliding guide rail, a first lead screw rotatably connected above the movable base, a servo motor fixedly connected to one side of the movable base, the servo motor being fixedly connected to the first lead screw, and a first nut disposed at the bottom of the round pipe clamps, the first nut being drivenly connected to the first lead screw via a thread; The round tube clamp includes a movable base plate, a slider is fixedly installed at the bottom of the movable base plate, two sets of V-shaped tube frames are fixedly connected above the movable base plate, a first rotating roller is laid on the V-shaped tube frame, the first rotating roller is rotatably connected to the V-shaped tube frame through a bearing, and the first rotating roller is drivenly connected to the first nut. A lifting clamping frame is installed above the two sets of V-shaped tube frames. A second lead screw is erected on both sides of the movable base plate. The second lead screw is rotatably connected to the movable base plate through an angular support bearing. A second nut is fixedly connected to both sides of the lifting clamping frame. The second nut is connected to the second lead screw through a threaded transmission. A first gear is fixedly connected to the bottom end of the second lead screw. A rack is installed on both sides of the movable base. The first gear and the rack mesh with each other.

[0005] Furthermore, this application also proposes that a second rotating roller is laid on the lifting clamping frame, the second rotating roller is rotatably connected to the lifting clamping frame through a bearing, the first rotating roller is laid in a V-shape, and the second rotating roller is laid in an inverted V-shape, the two cooperate with each other to clamp the pipe.

[0006] Furthermore, this application also proposes that there are two sets of sliding guide rails, and the two sets of sliding guide rails are parallel to each other, and there are four sets of sliders, with the four sets of sliders located at the four corners of the movable base plate.

[0007] Furthermore, this application also proposes that the first lead screw is a bidirectional lead screw with two sections of thread in opposite directions, and that the sliders at the bottom of the two sets of round tube clamps are respectively connected to the two sections of thread for transmission.

[0008] Furthermore, this application also proposes that a second fixing sleeve is provided on the outer sleeve of the second nut, the second fixing sleeve is fixedly connected to the lifting clamping frame by bolts, a first fitting block is fixedly connected to the outer wall of the second nut, and a first fitting groove is provided on the inner wall of the second fixing sleeve, the first fitting block and the first fitting groove fitting together.

[0009] Furthermore, this application also proposes that a first return spring is provided on the outer sleeve of the second nut, and the first return spring is located between the second nut and the second fixing sleeve.

[0010] Furthermore, this application also proposes that a first fixed sleeve is fixedly connected to the bottom of the movable base plate, a fitting sleeve is embedded in the first fixed sleeve, the fitting sleeve and the first fixed sleeve are fixedly connected by bolts, a movable sleeve is inserted into the fitting sleeve, a second fitting groove is opened on the fitting sleeve, a second fitting block is fixedly connected to the outer wall of the movable sleeve, and the second fitting block and the second fitting groove fit together.

[0011] Furthermore, this application also proposes that a first nut is inserted into the movable sleeve, the first nut is fixedly connected to the movable sleeve, a second return spring is provided on the outer sleeve of the movable sleeve, the second return spring is located between the movable sleeve and the first fixed sleeve, a first pulley is rotatably connected to one end of the first fixed sleeve, and a hexagonal prism is fixedly connected to one end of the movable sleeve, the hexagonal prism passes through the first pulley, and the first pulley drives the first rotating roller to rotate.

[0012] Furthermore, this application proposes that the elastic coefficient of the second return spring is greater than that of the first return spring. Thus, when the first lead screw drives the two sets of round pipe clamps to move relative to each other, the first return spring will be compressed first, causing the second nut to disengage from the second fixed sleeve, thereby stopping the lifting clamp from descending. Then, after the pipes are connected, the second return spring will be compressed, causing the fitting sleeve and the movable sleeve to disengage, thereby stopping the movement of the two sets of round pipe clamps. Then, the first lead screw drives the first rotating roller through the movable sleeve and the pulley gear transmission system to perform welding.

[0013] Furthermore, this application also proposes that the first pulley is connected to the second pulley via a synchronous belt drive, the second pulley is fixedly connected to one side of the second pulley, the second gear is rotatably connected to one side of the V-shaped tube frame, the second gear meshes with a third gear, and the third gear is fixedly connected to one end of the first rotating roller.

[0014] The technical effects and advantages of this invention are as follows: This application provides a welding device for butt welding of round pipes and its clamping and rotating mechanism. The round pipe clamp is driven to move synchronously by a bidirectional lead screw to achieve automatic centering. The clamping force is adaptively adjusted in conjunction with an elastic compensation mechanism. At the same time, the integrated transmission system realizes the coordinated operation of clamping and rotation. It has the advantages of simplifying the operation process, improving clamping stability, realizing automatic clamping force compensation and integrating rotation welding function. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the external structure of the present invention; Figure 2 This is a schematic diagram of the circular tube clamp structure of the present invention; Figure 3 This is a schematic diagram of the second nut and the second fixing sleeve structure of the present invention; Figure 4 This is a schematic cross-sectional view of the second fixed sleeve of the present invention; Figure 5 This is a schematic diagram of the first fitting groove structure of the present invention; Figure 6 This is a bottom view of the movable base plate structure of the present invention; Figure 7 This is a cross-sectional view of the first fixed sleeve structure of the present invention.

[0016] Legend: 1. Movable base; 2. Sliding guide rail; 3. Round tube clamp; 4. Slider; 5. First lead screw; 6. Servo motor; 7. First nut; 8. Movable base plate; 801. First fixed sleeve; 9. V-shaped tube frame; 901. First rotating roller; 10. Lifting clamping frame; 1001. Second rotating roller; 11. Second lead screw; 12. Second nut; 1201. First fitting block; 13. First gear; 14. Rack; 15. Second fixed sleeve; 1501. First fitting groove; 1502. First return spring; 16. Fitting sleeve; 1601. Second fitting groove; 17. Movable sleeve; 1701. Second fitting block; 1702. Hexagonal prism; 18. Second return spring; 19. First pulley; 20. Second pulley; 21. Second gear; 22. Third gear. Detailed Implementation

[0017] The technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. The components of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely represents selected embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application. It should be noted that similar reference numerals and letters in the following drawings indicate similar items; therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. Furthermore, in the description of this application, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0018] In existing technologies, the welding process of circular pipes requires multiple adjustments to the clamp position and manual locking of the device, which is cumbersome and inefficient. Traditional devices rely on mechanical locking structures to maintain the clamping state, which are prone to loosening under equipment vibration or external interference, leading to misalignment of the pipe ends. Especially in long-distance pipeline construction scenarios, repeated manual calibration not only increases labor intensity but also makes it difficult to ensure the uniformity of the weld, easily resulting in welding defects.

[0019] To solve the above problems, it is necessary to develop a device that can synchronously complete clamping and positioning and automatic centering. Through analysis, it is found that there is a possibility of linkage between pipe clamping and position adjustment. If the movement of the fixture and the clamping action can be controlled simultaneously by a single driving source, the operation process can be effectively simplified. Based on this, the designer considered mechanically linking the horizontal movement mechanism and the vertical clamping mechanism. When the fixture moves along the guide rail to the set position, the mechanical energy generated by the displacement is used to trigger the clamping action, realizing the coordinated control of positioning and clamping.

[0020] Therefore, this application proposes a structure including a moving base 1 and a sliding guide rail 2. Two sets of circular pipe fixtures 3 that can move synchronously are arranged on the guide rail. The bottom of the fixture forms a sliding fit with the guide rail through a slider 4 and is driven by a first screw rod 5 to move towards each other. The circular pipe fixture 3 includes a liftable clamping frame, and its lifting action is associated with the displacement of the base through a gear-rack 14 linkage mechanism. When the fixture moves, the rack 14 fixed to the base drives the gear to rotate, driving the vertical movement of the liftable clamping frame 10 to automatically clamp the pipe with the V-shaped pipe support 9, so as to facilitate welding by a welding robot on one side of the moving base 1.

[0021] Among them, the moving base 1 refers to the base platform that bears the overall structure, which can be specifically realized by a steel plate welded frame structure. Universal wheels or fixed feet can be installed at the bottom to support the whole device and realize position adjustment. The sliding guide rail 2 refers to the guiding component that guides the movement of the fixture, which can be realized by an I-beam track and a linear bearing to ensure the fixture moves smoothly along a straight line. The circular pipe fixture 3 refers to the combined structure for clamping the pipe, including a fixed V-shaped pipe support 9 and a movable liftable frame. The inclination angle of the V-shaped pipe support 9 can be adjusted according to the pipe diameter size, for example, realized by an adjustable-angle hinge bracket. The first screw rod 5 refers to the transmission component that drives the movement of the fixture, which can adopt a trapezoidal thread screw rod and a bidirectional nut structure to make the two sets of fixtures move towards each other synchronously. The servo motor 6 refers to the power driving unit, which can be directly connected to the screw rod through a coupling, for example, an AC servo motor 6 with an encoder is selected to achieve precise position control. The V-shaped pipe support 9 refers to the fixed support for supporting the pipe, and freely rotatable rollers can be arranged on its surface, for example, steel rollers supported by bearings are used to reduce the frictional resistance when the pipe moves. The liftable clamping frame 10 refers to the pressing mechanism that moves vertically and realizes height adjustment through a nut pair, for example, a rectangular-section guide column and a ball screw rod are used to improve the movement accuracy. The first gear 13 and the rack 14 refer to mechanical linkage components. The gear can be selected as a 20CrMnTi alloy steel gear, and the rack 14 can be selected as a quenched linear rack 14 to ensure the reliability of transmission.

[0022] Specifically, when the servo motor 6 drives the first lead screw 5 to rotate, the first lead screw 5 drives the two sets of round pipe clamps 3 to move towards each other along the sliding guide rail 2 via the first nut 7. During the movement, the gear fixed at the bottom of the clamp and the rack 14 on the side of the base are relatively displaced, causing the gear to rotate. The gear drives the second lead screw 11 to rotate via the coupling, and drives the lifting clamping frame 10 to descend along the guide column via the second nut 12. When the clamp moves to the set position, the inverted V-shaped roller at the bottom of the lifting clamping frame 10 and the V-shaped pipe frame 9 form a closed clamping space, and the pipe is automatically pressed between the two sets of rollers. During the clamping process, the rollers can rotate freely with the pipe, which is convenient for subsequent welding operations. The entire clamping action and position adjustment are completed by a single drive source, without the need for step-by-step operation of the locking device.

[0023] Compared to existing technologies, traditional devices require separate operation of the moving mechanism and the clamping mechanism. This solution achieves coordinated action through gear and rack linkage, merging two independent processes into a continuous motion. Existing technologies use rigid locking, which is susceptible to vibration. This solution utilizes the self-locking characteristic of screw drive to maintain clamping force, while the roller structure allows the pipe to rotate freely under clamping conditions. Traditional methods require manual adjustment of clamping height; this solution automatically achieves height matching through mechanical linkage, adapting to the clamping requirements of different pipe diameters.

[0024] With the above technical solution, operators only need to start the motor to simultaneously complete pipe positioning and clamping, reducing manual intervention. The clamping force is automatically applied and maintained constant through a screw drive, preventing loosening due to vibration. The roller structure allows the pipe to rotate while clamped, facilitating circumferential welding. The matching design of the V-shaped and inverted V-shaped clamping surfaces can adapt to pipes of different diameters, improving the device's versatility. The entire process eliminates the need for repeated adjustments to the locking device, significantly improving welding efficiency and quality consistency.

[0025] This application further proposes that a second rotating roller 1001 is laid on the lifting clamping frame 10. The second rotating roller 1001 is rotatably connected to the lifting clamping frame 10 through a bearing. The first rotating roller 901 is laid in a V-shape, and the second rotating roller 1001 is laid in an inverted V-shape. The two cooperate with each other to clamp the pipe.

[0026] The second rotating roller 1001 refers to a cylindrical rotating component mounted on the lifting clamping frame 10. Specifically, it can be implemented using a chrome-plated steel roller body with a deep groove ball bearing, with its axis perpendicular to the pipe axis. V-shaped laying refers to two sets of first rotating rollers 901 symmetrically arranged at a 120-degree angle to form a V-shaped support surface, while inverted V-shaped laying refers to two sets of second rotating rollers 1001 symmetrically arranged at a 60-degree angle to form an inverted V-shaped pressing surface. The diamond-shaped clamping space formed by their interaction allows the pipe to automatically center under pressure.

[0027] Specifically, when the lifting clamping frame 10 presses down, the inverted V-shaped second rotating roller 1001 and the V-shaped first rotating roller 901 work together to form four-point contact on the circumferential surface of the pipe. The pipe is constrained within a symmetrical clamping space formed by the two sets of V-shaped structures, and the normal directions of the contact points intersect at the pipe axis, resulting in a uniform distribution of clamping force. During pipe rotation, the four sets of rotating rollers rotate synchronously, maintaining clamping force while allowing circumferential rotation of the pipe. This structure can automatically correct pipe misalignment during welding, ensuring that the weld is always in the optimal welding position.

[0028] Compared to existing technologies, traditional clamping devices often employ a structure of a flat pressure plate and a V-shaped seat, where the pressure plate and the pipe are in surface contact, easily leading to sliding friction. This solution transforms sliding friction into rolling friction through point contact between an inverted V-shaped rotating roller and a V-shaped rotating roller, reducing rotational resistance while maintaining clamping force. Existing technologies require manual adjustment for pipe alignment, while this solution utilizes a symmetrical V-shaped structure to achieve automatic alignment.

[0029] Through the above technical solution, this application achieves automatic centering and stable rotation during pipe clamping, eliminating the need for manual adjustment. During welding operations, the symmetrical clamping structure formed by four sets of rotating rollers effectively suppresses pipe misalignment, ensuring a uniform and smooth weld. The rolling contact characteristics of the rotating rollers avoid the clamping force fluctuation problem caused by vibration in traditional clamping devices, making the welding process more stable and reliable.

[0030] This application further proposes that the sliding guide rail 2 is provided in two sets, and the two sets of sliding guide rail 2 are parallel to each other, and the slider 4 is provided in four sets, with the four sets of slider 4 located at the four corners of the movable base plate 8 respectively.

[0031] The parallelism of the sliding guide rails 2 means that the two track axes remain parallel. This can be achieved using high-precision linear guide rails combined with laser calibration technology to ensure that the moving base plate 8 does not deviate along its linear motion trajectory. The four sets of sliders 4 located at the four corners of the moving base plate 8 mean that the four sliding support points are distributed at the four vertices of the rectangular base plate. This can be achieved using equally spaced mounting holes for the sliders 4 to ensure that the moving base plate 8 is subjected to uniform force and avoids stress concentration on one side.

[0032] Specifically, two sets of parallel sliding guide rails 2 form a double-track bearing structure, and the movable base plate 8 forms four-point contact with the rails through the sliders 4 distributed at the four corners. When the servo motor 6 drives the first lead screw 5 to rotate, the bidirectional thread pushes the two sets of round pipe clamps 3 to move towards each other. Under the constraint of the double track, the four sets of sliders 4 maintain a linear motion trajectory, effectively preventing lateral displacement during movement. The four-corner support structure enables the movable base plate 8 to form a stable planar support, avoiding clamp tilting due to uneven weight distribution of the pipe, and ensuring that the clamping axis is always in a horizontal state.

[0033] Compared with existing technologies, traditional circular pipe welding devices often use a single track with a double slider 4 structure, which is prone to track deformation and movement jamming when bearing large-diameter pipes. This solution forms a redundant load-bearing structure by arranging the double tracks in parallel, and forms a rectangular support frame with the sliders 4 distributed at the four corners, which significantly improves the bending rigidity and movement stability of the moving base plate 8.

[0034] Through the above technical solution, this application effectively solves the problem of decreased motion accuracy caused by easy deformation of traditional single-track structures under heavy load conditions. The rigid support structure of double track and four sliders 4 ensures the straightness of the movement trajectory during pipe docking. At the same time, the design of sliders 4 evenly distributed at the four corners eliminates the risk of clamp tilting caused by eccentric load, providing a stable motion foundation for high-precision welding operations.

[0035] This application further proposes a welding device for connecting round pipes, wherein the first lead screw 5 is a first lead screw 5 with two sections of threads in opposite directions, and the sliders 4 at the bottom of the two sets of round pipe clamps 3 are respectively connected to the two sections of threads for transmission.

[0036] The first lead screw 5 refers to a rod with two sections of threaded structure with opposite directions of rotation. Specifically, it can be implemented using a trapezoidal thread or a ball thread structure, with the two threaded sections located at opposite ends of the lead screw's axial direction. The opposite thread direction allows the two sets of circular tube clamps 3 to move synchronously in opposite directions when the lead screw rotates. The connection between the slider 4 and the threaded drive can be achieved by creating a threaded hole at the bottom of the slider 4, for example, by using a copper-based alloy material to make the threaded hole to reduce the coefficient of friction.

[0037] Specifically, when the servo motor 6 drives the first lead screw 5 to rotate, the two sets of clamps will move synchronously in opposite directions along the sliding guide rail 2 because the sliders 4 at the bottom of the two sets of pipe clamps 3 engage with the threaded sections with opposite directions of rotation. This structure enables the pipe clamping mechanism to achieve bidirectional synchronous displacement during the docking process, avoiding the off-center load problem caused by unilateral drive. The symmetrical layout of the first lead screw 5 effectively simplifies the transmission system structure, requiring only a single power source to achieve coordinated movement of the two sets of clamps, ensuring the coaxiality of the pipe end faces during the docking process.

[0038] Compared to existing technologies, traditional round tube welding devices often use a single-threaded lead screw with an independent drive mechanism to move the clamp, resulting in complex structures and low synchronization accuracy. However, by adopting a first lead screw 5 transmission structure, the control errors caused by multiple power sources are eliminated through mechanical forced synchronization, while also reducing the number of transmission components. Compared to a split lead screw structure, this solution reduces manufacturing costs and maintenance difficulty while maintaining motion accuracy.

[0039] Through the above technical solution, this application achieves precise synchronous displacement of the pipe clamping mechanism during the docking process, solving the pipe misalignment problem caused by asynchronous movement in traditional devices. The forced synchronization characteristic of the first lead screw 5 ensures uniform force on the welding joint, avoiding weld deformation caused by unilateral extrusion. The mechanical constraint characteristic of the reverse-arranged threads effectively prevents displacement deviation caused by vibration during clamp movement, improving the forming quality of the welded joint.

[0040] This application further proposes that a second fixing sleeve 15 is provided on the outer sleeve of the second lead screw 11 nut, the second fixing sleeve 15 is fixedly connected to the lifting clamp 10 by bolts, a first fitting block 1201 is fixedly connected to the outer wall of the second lead screw 11 nut, and a first fitting groove 1501 is provided on the inner wall of the second fixing sleeve 15, the first fitting block 1201 and the first fitting groove 1501 are fitted together.

[0041] The second fixed sleeve 15 is a cylindrical structure used to rigidly connect the second lead screw 11 nut to the lifting clamp 10. Specifically, it can be a steel sleeve with a flange connected to the side of the lifting clamp 10 by bolts. Its inner diameter is slightly larger than the outer diameter of the second lead screw 11 nut to form a clearance fit. The first fitting block 1201 is a protruding structure extending axially along the outer circumference of the second lead screw 11 nut. Specifically, it can be a trapezoidal metal strip welded to the outer wall of the nut, with a height of 0.5-2 mm. The first fitting groove 1501 is a groove structure complementary in shape to the first fitting block 1201. Specifically, it can be formed by milling on the inner wall of the second fixed sleeve 15, with a groove depth of 1-3 mm, used to transmit rotational torque and allow axial relative sliding.

[0042] Specifically, during the descent of the lifting clamping frame 10, the second lead screw 11 nut forms a torque transmission connection with the first fitting groove 1501 of the second fixed sleeve 15 through the first fitting block 1201. After the pipe is clamped, the continued rotation of the second lead screw 11 will cause the second lead screw 11 nut to have a downward displacement tendency. At this time, the first fitting block 1201 slides axially along the first fitting groove 1501. When the axial force exceeds the preload of the first return spring 1502, the second lead screw 11 nut and the second fixed sleeve 15 separate axially. After separation, the second lead screw 11 nut can rotate freely. At this time, the compression of the first return spring 1502 determines the magnitude of the clamping force. For example, every 1 mm increase in spring compression can generate a clamping force of about 50 Newtons. This structure makes the clamping force no longer dependent on the thread friction, but dynamically adjusted by the spring deformation.

[0043] Compared to existing technologies, traditional clamping devices employ a threaded self-locking structure, which is prone to clamping force attenuation under vibration conditions due to loosening of the threaded pair. This solution utilizes a separable interlocking structure with an elastic element to automatically release the rigid connection after reaching the preset clamping force, forming a constant-force clamping system based on spring force. For example, when a pipe expands or contracts due to thermal expansion or contraction, the spring can automatically compensate for deformation and maintain the clamping force, whereas traditional structures may cause pipe deformation due to thread seizing in this situation.

[0044] Through the above technical solution, this application achieves automatic compensation and dynamic maintenance of clamping force, effectively solving the problem of clamping force attenuation caused by vibration or temperature changes in mechanical locking devices. During the welding process, even if the pipeline undergoes slight deformation, the first return spring 1502 can still maintain a constant contact pressure through extension and retraction adjustment, avoiding weld misalignment caused by loose clamping.

[0045] This application further proposes that a first return spring 1502 is provided on the outer sleeve of the nut of the second lead screw 11, and the first return spring 1502 is located between the nut of the second lead screw 11 and the second fixed sleeve 15.

[0046] The second lead screw 11 nut is a component that is connected to the second lead screw 11 via a thread, specifically a metal sleeve with internal threads, used to convert the rotational motion of the lead screw into linear motion. The first return spring 1502 is an elastic element sleeved outside the second lead screw 11 nut, specifically a helical compression spring, with its two ends abutting between the second lead screw 11 nut and the second fixed sleeve 15, respectively, to provide axial elastic force. The second fixed sleeve 15 is a rigid structure sleeved outside the second lead screw 11 nut, specifically a metal sleeve with an embedded groove, fixedly connected to the lifting clamp 10 by bolts, used to restrict the rotational freedom of the second lead screw 11 nut.

[0047] Specifically, when the second lead screw 11 rotates and drives the lifting clamping frame 10 to descend to the pipe clamping position, the first return spring 1502 between the nut of the second lead screw 11 and the second fixed sleeve 15 is compressed. At this time, the engagement structure between the nut of the second lead screw 11 and the second fixed sleeve 15 disengages, and the nut of the second lead screw 11 can rotate freely. However, the elastic force of the first return spring 1502 continues to act on the clamping structure, so that the lifting clamping frame 10 maintains a constant clamping force on the pipe. When the pipe undergoes slight displacement due to vibration, the elastic deformation of the first return spring 1502 can automatically compensate for the loss of clamping force, preventing the clamping from loosening.

[0048] Compared to existing technologies, traditional devices employ a rigid locking structure, and the clamping force cannot be dynamically adjusted. This solution, however, utilizes the elastic properties of the first return spring 1502 to create an adaptive force compensation mechanism after clamping. In existing technologies, the clamping force gradually decreases with mechanical wear, while this solution maintains clamping stability through the continuous action of the spring, significantly improving the positioning accuracy of the pipeline during welding.

[0049] Through the above technical solution, this application effectively solves the problem of clamping loosening caused by vibration or deformation after pipe clamping. Through the synergistic effect of elastic elements and rigid structures, it automatically enters a force-holding state after initial clamping, which not only ensures clamping reliability but also avoids equipment damage caused by over-tightening, making it particularly suitable for operation scenarios requiring long-term continuous welding.

[0050] This application further proposes that the bottom of the movable base plate 8 is fixedly connected to a first fixed sleeve 801, and a fitting sleeve 16 is embedded in the first fixed sleeve 801. The fitting sleeve 16 and the first fixed sleeve 801 are fixedly connected by bolts. A movable sleeve 17 is inserted into the fitting sleeve 16. A second fitting groove 1601 is opened on the fitting sleeve 16. A second fitting block 1701 is fixedly connected to the outer wall of the movable sleeve 17. The second fitting block 1701 and the second fitting groove 1601 fit into each other.

[0051] The first fixed sleeve 801 refers to a metal tubular structure welded or bolted to the bottom of the movable base plate 8. It can be implemented using a hollow cylindrical steel component and serves as an mounting base for the fitting sleeve 16. The fitting sleeve 16 is a transitional connecting component embedded inside the first fixed sleeve 801. It can be implemented using a metal sleeve with a fitting groove on its inner wall and is rigidly connected to the first fixed sleeve 801 by bolts. The movable sleeve 17 is a tubular component that can slide axially along the inner cavity of the fitting sleeve 16. It can be implemented using a metal sleeve with a protruding fitting block fixedly connected to its outer wall. The fit between the fitting block and the fitting groove can both transmit torque and achieve axial limiting. The second fitting groove 1601 is a groove structure extending circumferentially along the inner wall of the fitting sleeve 16. It can be implemented using a rectangular groove formed by milling and is used to form a sliding fit with the fitting block on the outer wall of the movable sleeve 17.

[0052] Specifically, during the pipe clamping stage, the movable sleeve 17 is engaged with the second fitting groove 1601 of the fitting sleeve 16 via the second fitting block 1701, allowing the axial movement of the first lead screw 5 nut to drive the overall movement of the movable base plate 8. When the pipe connection is completed, the continuous driving force of the first lead screw 5 causes the movable sleeve 17 to overcome the resistance of the second return spring 18, and the second fitting block 1701 disengages from the second fitting groove 1601. At this point, the torque transmission relationship between the movable sleeve 17 and the fitting sleeve 16 is released. After disengagement, the movable sleeve 17 can rotate freely, thereby driving the first pulley 19 to rotate via the hexagonal prism 1702, ultimately driving the first rotating roller 901 to achieve pipe rotation welding.

[0053] Compared to existing technologies, traditional devices cannot automatically switch to rotary welding mode after pipe docking, requiring manual intervention to adjust the transmission mechanism. This solution, however, utilizes a separable design between the fitted sleeve 16 and the movable sleeve 17 to automatically release torque transmission when the pipe docking pressure reaches a threshold, achieving a seamless switch from clamping and moving mode to rotary welding mode. This avoids efficiency losses and positioning errors caused by manual operation.

[0054] Through the above technical solution, this application can automatically trigger the transmission mechanism to switch after the pipeline docking is completed, ensuring that the clamping mechanism drives the pipeline to rotate while maintaining a constant docking pressure. This solves the technical problem that traditional devices require step-by-step operation of clamping, positioning and rotation welding, and significantly improves the degree of welding automation and weld formation quality.

[0055] This application further proposes that a first lead screw 5 nut is inserted into the movable sleeve 17, the first lead screw 5 nut is fixedly connected to the movable sleeve 17, a second return spring 18 is provided on the outer sleeve of the movable sleeve 17, the second return spring 18 is located between the movable sleeve 17 and the first fixed sleeve 801, a first pulley 19 is rotatably connected to one end of the first fixed sleeve 801, a hexagonal prism 1702 is fixedly connected to one end of the movable sleeve 17, the hexagonal prism 1702 passes through the first pulley 19, and the first pulley 19 drives the first rotating roller 901 to rotate.

[0056] The movable sleeve 17 is a hollow tubular structure used to accommodate the first lead screw 5 nut and transmit power. It can be made of stainless steel, and its inner wall is fixedly connected to the outer wall of the first lead screw 5 nut by welding or interference fit. It converts the rotational motion of the first lead screw 5 into linear displacement. The second return spring 18 is a helical spring sleeved on the outside of the movable sleeve 17 to provide elastic cushioning. It can be made of spring steel, and its two ends abut against the end faces of the movable sleeve 17 and the first fixed sleeve 801, respectively, to maintain the pipe connection pressure after clamping. The fitting sleeve 16 is a connecting component embedded inside the first fixed sleeve 801 and fixed with bolts. It can be an aluminum alloy sleeve with an axial groove. The second fitting groove 1601 on its inner wall forms a sliding fit with the second fitting block 1701 on the outer wall of the movable sleeve 17, restricting the rotational freedom of the movable sleeve 17. Among them, the hexagonal prism 1702 refers to the hexagonal prism structure fixed at the end of the movable sleeve 17, which can be made of carbon steel. Its hexagonal through hole penetrating the center of the first pulley 19 is used to drive the first pulley 19 to rotate when the movable sleeve 17 moves axially.

[0057] Specifically, when the two sets of round pipe clamps 3 bring the pipes closer together until the interface contacts, the first lead screw 5 continues to rotate, pushing the nut of the first lead screw 5 to move axially. At this time, the movable sleeve 17 is subjected to axial thrust, compressing the second return spring 18, causing the second fitting block 1701 to disengage from the second fitting groove 1601. After disengagement, the movable sleeve 17 can rotate freely, and the hexagonal prism 1702 then drives the first pulley 19 to rotate, driving the first rotating roller 901 to rotate through the synchronous belt transmission system, thereby causing the clamped round pipe to rotate circumferentially. During this process, the preload of the second return spring 18 continues to act on the movable sleeve 17, ensuring that the pipe mating surfaces always maintain a tight contact state.

[0058] Compared with existing technologies, traditional devices cannot achieve automatic rotational welding after pipe docking, requiring an additional drive mechanism to complete the circumferential machining of the weld. In contrast, this solution uses a lead screw to push the movable sleeve 17 out of the fitting constraint, and then directly uses the rotational power of the lead screw to drive the rotating roller, achieving the pipe's self-rotation function while maintaining clamping force, simplifying the transmission structure and reducing manufacturing costs.

[0059] Through the above technical solution, this application can automatically switch to rotary welding mode after the pipeline docking is completed. The spring preload maintains constant docking pressure, avoiding misalignment of the interface due to vibration during the welding process. At the same time, the remaining driving force of the screw is used to realize the circumferential rotation of the pipeline, ensuring uniform and continuous weld formation.

[0060] This application further proposes a welding device for pipe butt welding. The elastic coefficient of the second return spring 18 is greater than that of the first return spring 1502. Therefore, when the first lead screw 5 drives the two sets of pipe clamps 3 to move relative to each other, the first return spring 1502 will be compressed first, causing the nut of the second lead screw 11 to disengage from the second fixed sleeve 15, and the lifting clamp 10 to stop descending. The second return spring 18 will be compressed after the pipe is butt welded, causing the fitting sleeve 16 and the movable sleeve 17 to disengage, and the two sets of pipe clamps 3 to stop moving. The first lead screw 5 drives the first rotating roller 901 to perform welding through the movable sleeve 17 and the pulley gear transmission system.

[0061] The elastic coefficient of the second return spring 18 refers to the reaction force generated by the spring under a unit deformation. Specifically, it can be achieved using a high-carbon steel spring, and its stiffness value can be 1.2-1.5 times that of the first return spring 1502. The compression stroke of the first return spring 1502 controls the timing of the disengagement between the nut of the second lead screw 11 and the second fixed sleeve 15. For example, the engagement structure completely separates when the spring compression reaches 5 mm. The disengagement of the movable sleeve 17 from the engaging sleeve 16 refers to the axial displacement between the hexagonal prism 1702 and the first pulley 19, which can be achieved through a sliding fit structure with a hexagonal cross-section.

[0062] Specifically, when the servo motor 6 drives the first lead screw 5 to rotate, the two sets of round pipe clamps 3 move towards each other along the sliding guide rail 2. In the initial stage, the second return spring 18 is not compressed, and the first return spring 1502 is compressed first due to the obstruction of the lifting clamp 10, causing the nut of the second lead screw 11 to disengage from the second fixed sleeve 15, and the lifting clamp 10 remains stationary. After the pipe end face contacts and forms resistance, the axial force generated by the continued rotation of the first lead screw 5 begins to compress the second return spring 18. When the pressure reaches the set threshold, the movable sleeve 17 disengages from the fitting sleeve 16. At this time, the first lead screw 5 drives the first pulley 19 to rotate through the hexagonal prism 1702, and drives the first rotating roller 901 to rotate the pipe through the synchronous belt and gear transmission.

[0063] In some specific embodiments, the preload of the second return spring 18 can be adjusted by an adjusting bolt, for example, by providing a threaded adjustment mechanism at the end of the movable sleeve 17. The engagement length between the first pulley 19 and the hexagonal prism 1702 can be 20 mm to ensure effective transmission before disengagement. A guide groove can be provided inside the fitting sleeve 16, and the sliding stroke of the second fitting block 1701 is limited to 8 mm to control the timing of disengagement.

[0064] Compared to existing technologies, traditional devices cannot control the release of clamping force and the start of rotation drive in stages during clamping and movement. This solution achieves sequential control of actions through differences in elastic coefficients. In existing technologies, clamping and rotation need to be operated separately; this solution automatically switches to rotation mode after pipe connection, reducing manual intervention.

[0065] Through the above technical solution, this application achieves phased control of clamping force and driving force, automatically initiating the rotary welding function after ensuring precise pipe alignment. When there is a slight misalignment at the pipe contact surface, the continuous pressure of the second return spring 18 can automatically compensate for the gap, ensuring uniform weld seam. The synergistic effect of the two sets of springs enables the device to maintain a stable clamping state under vibration conditions, preventing displacement during welding.

[0066] This application further proposes that the first pulley 19 is connected to the second pulley 20 via a synchronous belt drive, the second pulley 20 is fixedly connected to one side of the second gear 21, the second gear 21 is rotatably connected to one side of the V-shaped tube frame 9, the second gear 21 meshes with the third gear 22, and the third gear 22 is fixedly connected to one end of the first rotating roller 901.

[0067] Synchronous belt drive refers to a transmission method that transmits power through the meshing of belt teeth and pulley teeth. Specifically, it can be implemented using synchronous belts made of rubber or polyurethane materials with a toothed surface, such as HTD or GT type synchronous belts. The second pulley 20 is the driven pulley connected to the first pulley 19 via a synchronous belt; its diameter and number of teeth can be adjusted according to the transmission ratio requirements. The second gear 21 is a gear fixed coaxially with the second pulley 20, such as a spur gear or helical gear, with its module and number of teeth designed according to the transmission requirements. The third gear 22 is a gear that meshes with the second gear 21 and is fixed to the end of the first rotating roller 901; its module matches that of the second gear 21, for example, using a spur gear with the same module to achieve smooth meshing.

[0068] Specifically, when the first pulley 19 is driven to rotate, power is transmitted to the second pulley 20 via a synchronous belt, causing the second gear 21 to rotate around its axis. Since the second gear 21 meshes with the third gear 22, the third gear 22, along with the rotation of the second gear 21, drives the first rotating roller 901 to rotate around its own axis. For example, when the first rotating roller 901 is driven, its surface contacts the pipe, generating friction and causing the pipe to rotate slowly axially, thus facilitating continuous welding of the circumferential weld.

[0069] Compared with existing technologies, traditional round pipe welding devices usually require an additional motor or manual rotation mechanism to drive the pipe rotation, resulting in a complex structure and large space occupation. In contrast, this solution uses a combination of synchronous belt and gear transmission to directly convert the rotational motion of the first pulley 19 into the drive of the first rotating roller 901, eliminating the need for an additional independent drive component. This results in a more compact structure and a clear transmission path, avoiding energy loss or slippage problems caused by multi-stage transmission.

[0070] Through the above technical solution, this application achieves the automatic rotation function of the pipeline in the clamped state, enabling the pipeline to rotate at a uniform speed during the welding process, ensuring uniform heating of the weld and the formation of a continuous molten pool. Simultaneously, the gear meshing transmission has high positioning accuracy, avoiding pipeline position deviation caused by transmission clearance, thereby improving welding quality and efficiency.

[0071] The above description is merely an embodiment of this application and is not intended to limit the scope of protection of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A welding device for butt welding of circular pipes, characterized in that, include: A mobile base (1) is provided with a welding robot on one side. A sliding guide rail (2) is fixedly connected above the mobile base (1). Two sets of round tube clamps (3) are provided on the sliding guide rail (2). A slider (4) is provided at the bottom of the round tube clamp (3). The slider (4) is slidably connected to the sliding guide rail (2). A first lead screw (5) is rotatably connected above the mobile base (1). A servo motor (6) is fixedly connected to one side of the mobile base (1). The servo motor (6) is fixedly connected to the first lead screw (5). A first nut (7) is provided at the bottom of the round tube clamp (3). The first nut (7) is connected to the first lead screw (5) by a thread. The round tube clamp (3) includes a movable base plate (8), the slider (4) is fixedly installed at the bottom of the movable base plate (8), and two sets of V-shaped tube frames (9) are fixedly connected above the movable base plate (8). A first rotating roller (901) is laid on the V-shaped tube frame (9). The first rotating roller (901) is rotatably connected to the V-shaped tube frame (9) through a bearing. The first rotating roller (901) is connected to the first nut (7) in a transmission connection. A lifting clamping frame (10) is provided above the two sets of V-shaped tube frames (9). A second lead screw (11) is erected on both sides of the movable base plate (8). The second lead screw (11) is rotatably connected to the movable base plate (8) through an angular support bearing. A second nut (12) is fixedly connected to both sides of the lifting clamping frame (10). The second nut (12) is connected to the second lead screw (11) through a thread. A first gear (13) is fixedly connected to the bottom end of the second lead screw (11). A rack (14) is provided on both sides of the movable base (1). The first gear (13) and the rack (14) mesh with each other. The second nut (12) is covered with a second fixing sleeve (15), which is fixedly connected to the lifting clamp (10) by bolts. The outer wall of the second nut (12) is fixedly connected with a first fitting block (1201), and the inner wall of the second fixing sleeve (15) is provided with a first fitting groove (1501). The first fitting block (1201) and the first fitting groove (1501) fit into each other. The second nut (12) is fitted with a first return spring (1502), which is located between the second nut (12) and the second fixing sleeve (15); The bottom of the movable base plate (8) is fixedly connected to a first fixed sleeve (801), and a fitting sleeve (16) is embedded in the first fixed sleeve (801). The fitting sleeve (16) and the first fixed sleeve (801) are fixedly connected by bolts. A movable sleeve (17) is inserted into the fitting sleeve (16). A second fitting groove (1601) is provided on the fitting sleeve (16). A second fitting block (1701) is fixedly connected to the outer wall of the movable sleeve (17). The second fitting block (1701) and the second fitting groove (1601) fit into each other. A first nut (7) is inserted into the movable sleeve (17), and the first nut (7) is fixedly connected to the movable sleeve (17). A second return spring (18) is provided on the outer sleeve of the movable sleeve (17), and the second return spring (18) is located between the movable sleeve (17) and the first fixed sleeve (801).

2. The welding device for butt welding of circular tubes according to claim 1, characterized in that, The lifting clamping frame (10) is provided with a second rotating roller (1001). The second rotating roller (1001) is rotatably connected to the lifting clamping frame (10) through a bearing. The first rotating roller (901) is laid in a V-shape, and the second rotating roller (1001) is laid in an inverted V-shape.

3. The welding device for butt welding of circular tubes according to claim 1, characterized in that, The sliding guide rail (2) is provided in two sets, and the two sets of sliding guide rail (2) are parallel to each other. The slider (4) is provided in four sets, and the four sets of slider (4) are located at the four corners of the movable base plate (8).

4. The welding device for butt welding of circular tubes according to claim 1, characterized in that, The first lead screw (5) is a bidirectional lead screw with two sections of thread in opposite directions, and the sliders (4) at the bottom of the two sets of round tube clamps (3) are respectively connected to the two sections of thread transmission.

5. The welding device for butt welding of circular tubes according to claim 1, characterized in that, The first fixed sleeve (801) is rotatably connected to a first pulley (19) at one end, and the movable sleeve (17) is fixedly connected to a hexagonal prism (1702) at one end. The hexagonal prism (1702) passes through the first pulley (19), and the first pulley (19) drives the first rotating roller (901) to rotate.

6. A welding device for butt welding of circular tubes according to claim 5, characterized in that, The elastic coefficient of the second return spring (18) is greater than that of the first return spring (1502).

7. A welding device for butt welding of circular tubes according to claim 5, characterized in that, The first pulley (19) is connected to the second pulley (20) via a synchronous belt drive. The second pulley (20) is fixedly connected to one side of the second gear (21). The second gear (21) is rotatably connected to one side of the V-shaped tube frame (9). The second gear (21) meshes with a third gear (22). The third gear (22) is fixedly connected to one end of the first rotating roller (901).

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