Auxiliary device for HDPE pipe head welding and HDPE pipe head welding method

Abstract

The invention relates to an auxiliary device for HDPE pipe head welding and an HDPE pipe head welding method. The auxiliary device for welding the HDPE pipe head comprises an arc-shaped clamping hoop, an elastic part, a hoop, a tensioning structure, a laser positioning structure, a controller and an alarm. The multiple arc-shaped hoops are distributed in the circumferential direction of the inserting opening of the HDPE pipe head, the arc-shaped hoops are attached and fixed to the inner wall of the inserting opening, and a gap is formed between every two adjacent arc-shaped hoops; the elastic parts are in one-to-one correspondence with the gaps, and the elastic parts cross the corresponding gaps and are connected with the two corresponding adjacent arc-shaped hoops; the hoop is arranged on the periphery of the inserting opening in a surrounding mode and tightened through the tightener, and the hoop corresponds to the circular-arc-shaped clamping hoop in position. The tensioning structure is connected with the circular-arc-shaped hoop and used for driving the circular-arc-shaped hoop to be tightly attached to the inner wall of the inserting opening; the multiple sets of laser positioning structures are arranged on the inner wall of the socket at intervals in the circumferential direction of the socket, and the laser positioning structures and the alarm are connected with the controller. The welding quality and the welding efficiency of the HDPE pipe head can be improved.

Description

Technical Field

[0001] This invention relates to the field of HDPE pipe welding technology. Specifically, it relates to an auxiliary device and a method for welding HDPE pipe ends. Background Technology

[0002] The water discharged from power plant circulating water systems is characterized by high temperature and large flow rate, thus requiring immersed tube culverts for drainage. However, immersed tube culverts are costly to manufacture and technically challenging. Currently, ultra-large diameter HDPE pipes are used as a primary alternative to immersed tube culverts to reduce costs and simplify the process.

[0003] Large-diameter HDPE pipes (high-density polyethylene pipes, diameter ≥ 3 meters) require hot-melt welding for long-distance splicing. This welding method involves first fitting an electrofusion fitting onto the pipe, then using a specialized welding machine to energize the fitting according to set parameters (time, voltage, etc.). This melts the inner surface of the fitting with its embedded heating wire and the outer surface of the pipe insertion end. After cooling, the pipe and fitting are fused together. However, using existing hot-melt welding methods to connect large-diameter HDPE pipe ends presents the following problems:

[0004] (1) Thermal expansion and deformation: During electrofusion welding, the HDPE pipe socket expands due to heat, causing the pipe opening to expand radially and the gap between it and the spigot to increase, which can easily lead to incomplete welding or insufficient welding strength.

[0005] (2) Insufficient internal support: The existing electrofusion process relies on manual temporary fixing of the electrofusion wire inside the pipe, but it is difficult to operate under ultra-large pipe diameter. The electrofusion wire is not tightly attached to the pipe wall and is easy to shift or fall off.

[0006] (3) Low construction efficiency: The position of the socket needs to be manually calibrated multiple times, and a single welding takes several hours. Moreover, the quality is greatly affected by the operator's experience. Summary of the Invention

[0007] The purpose of this invention is to provide an auxiliary device and a method for welding HDPE pipe ends, which can improve the welding quality and efficiency of HDPE pipe ends.

[0008] To achieve this objective, the present invention adopts the following technical solution:

[0009] On the one hand, an auxiliary device for welding HDPE pipe ends is provided, comprising:

[0010] Multiple arc-shaped clamps are provided, all of which are distributed circumferentially along the socket of the HDPE pipe head. The arc-shaped clamps are fitted and fixed to the inner wall of the socket, and there is a gap between two adjacent arc-shaped clamps.

[0011] Multiple elastic parts are provided, each elastic part corresponding to a gap, and each elastic part crosses the corresponding gap and is connected to the corresponding two adjacent arc-shaped clamps.

[0012] A clamp is provided around the outer periphery of the insertion port and is tightened by a tightener; the position of the clamp corresponds to that of the arc-shaped clamp.

[0013] A tensioning structure is provided, which is connected to the arc-shaped clamp and is used to drive the arc-shaped clamp to fit tightly against the inner wall of the insertion port.

[0014] Multiple sets of laser positioning structures are provided, all of which are spaced apart along the circumferential direction of the socket on the inner wall of the socket.

[0015] The controller and the alarm are both connected to the controller.

[0016] As a further embodiment of the auxiliary device for welding HDPE pipe ends, the arc-shaped clamp has a groove on the side opposite to the inner wall of the socket, and the length of the groove extends along the circumference of the arc-shaped clamp and passes through both ends of the arc-shaped clamp.

[0017] The auxiliary device for welding HDPE pipe ends also includes multiple alignment pieces, each of which corresponds to a gap. One end of each alignment piece extends into the slot and is fixedly connected to the slot of the corresponding arc-shaped clamp, while the other end extends into the slot of another adjacent arc-shaped clamp.

[0018] As a further embodiment of the auxiliary device for welding HDPE pipe ends, it also includes multiple high-temperature resistant gaskets, with one high-temperature resistant gasket in each of the slots. The high-temperature resistant gaskets extend along the length of the slot and are fixed to the bottom of the slot. The alignment piece is connected to the high-temperature resistant gasket.

[0019] As a further embodiment of the auxiliary device for welding HDPE pipe ends, the tensioning structure includes a plurality of first jacks, each of which corresponds one-to-one with the gap. The first jack is connected to two adjacent arc-shaped clamps and is close to the corresponding gap.

[0020] As a further embodiment of the auxiliary device for welding HDPE pipe ends, the number of the arc-shaped clamps is two; the tensioning structure also includes a second jack, which is connected to the circumferential center of the two arc-shaped clamps and extends radially along the insertion port.

[0021] As a further embodiment of the auxiliary device for HDPE pipe welding, each set of the laser positioning structure includes a laser emitter and a laser receiver mounted on the inner wall of the socket, with the line connecting the laser emitter and the laser receiver extending radially along the socket.

[0022] As a further embodiment of the auxiliary device for welding HDPE pipe ends, the elastic part includes a V-shaped steel sheet and two connecting steel sheets connected to both ends of the V-shaped steel sheet. The end of each connecting steel sheet away from the V-shaped steel sheet extends into the groove and is welded and fixed to the corresponding arc-shaped clamp; or...

[0023] The elastic part includes a first connecting steel plate, two inclined steel plates at an angle, and two second connecting steel plates corresponding to the inclined steel plates. The ends of the two inclined steel plates that are close to each other are connected by the first connecting steel plate, and the ends of the two inclined steel plates that are away from the first connecting steel plate are respectively connected to a corresponding second connecting steel plate. The end of the second connecting steel plate that is away from the inclined steel plate extends into the corresponding slot and is welded and fixed to the corresponding arc-shaped clamp.

[0024] As a further embodiment of the auxiliary device for welding HDPE pipe ends, the distance between the clamp and the welding surface of the socket is less than 0.2m, and the laser positioning structure is adjacent to the arc-shaped clamp and located on the side of the arc-shaped clamp facing the welding surface.

[0025] On the other hand, a method for welding HDPE pipe ends is provided, utilizing the aforementioned auxiliary device for welding HDPE pipe ends, the HDPE pipe end welding method comprising:

[0026] A first HDPE pipe end with a spigot and a second HDPE pipe end with a socket are provided. Multiple arc-shaped clamps are fixed circumferentially on the inner wall of the spigot of the first HDPE pipe end, and a gap is made between two adjacent arc-shaped clamps.

[0027] An elastic part is provided for each gap, and the two corresponding arc-shaped clamps are fixedly connected to the elastic part;

[0028] A clamp is installed on the outer wall of the socket of the first HDPE pipe head, adjacent to the welding surface, and tightened by a tightener;

[0029] An expansion structure connected to the arc-shaped clamp is installed inside the socket of the first HDPE pipe head;

[0030] Insert the socket of the first HDPE pipe head into the socket of the second HDPE pipe head, and use a laser positioning structure to position and calibrate the alignment of the socket and the socket. Then, energize the electrofusion wire embedded in the welding surface of the first HDPE pipe head to connect the two first HDPE pipe heads and the second HDPE pipe head.

[0031] During the docking process, if the inner diameter deviation of the first HDPE pipe head detected by the laser positioning structure exceeds ±1mm, the controller controls the alarm to issue an alarm signal, suspends the welding, and adjusts the tensioning structure until the inner diameter deviation detected by the laser positioning structure does not exceed ±1mm.

[0032] As a further embodiment of the HDPE pipe head welding method, multiple high-temperature resistant gaskets corresponding one-to-one with the number of the arc-shaped clamps and multiple alignment pieces corresponding one-to-one with the gaps are provided. The high-temperature resistant gaskets are fixed to the bottom of the grooves of the arc-shaped clamps, and the two ends of the alignment pieces are inserted into the grooves of two adjacent arc-shaped clamps. Then, one end of the alignment piece is welded and fixed to the corresponding arc-shaped clamp or the high-temperature resistant gasket.

[0033] The beneficial effects of this invention are:

[0034] This invention employs a split, arc-shaped clamp that fits snugly against the inner wall of the socket. Combined with the tightening effect of the external clamp to limit deformation at the hot-melt position and the internal tensioning structure, it achieves multi-directional, uniform fastening of the HDPE pipe end socket, effectively enhancing welding stability. The elastic section design allows for a certain degree of deformation while maintaining structural integrity, preventing excessive deformation that could damage the electrofusion wire. When the electrofusion wire heats up, elastic deformation absorbs the radial expansion of the socket, thus adapting to changes in the HDPE pipe end's thermal expansion and contraction and avoiding stress concentration. The linkage between the laser positioning structure, alarm, and controller enables precise alignment and real-time monitoring of the welding process, significantly improving welding accuracy and automation. The overall structure balances rigid constraints with flexible adjustment, offering significant advantages in improving welding quality, reducing operational difficulty, and minimizing human error. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the assembly structure of the auxiliary device for welding HDPE pipe ends and the HDPE pipe end in one embodiment.

[0036] Figure 2 This is a side view of the auxiliary device for welding HDPE pipe ends and the HDPE pipe end in one embodiment.

[0037] Figure 3 yes Figure 2 A magnified view of part M in the middle;

[0038] Figure 4 yes Figure 2 Schematic cross-section along direction AA;

[0039] Figure 5 This is a schematic diagram of the auxiliary device for welding HDPE pipe ends in one embodiment (after removing the clamp, laser positioning structure and tightener);

[0040] Figure 6 This is a side view of the elastic portion in another embodiment;

[0041] Figure 7 This is a cross-sectional schematic diagram of an auxiliary device for welding HDPE pipe ends in one embodiment;

[0042] Figure 8 yes Figure 7 A magnified view of part N in the middle.

[0043] In the picture:

[0044] 1. First HDPE pipe end; 2. Second HDPE pipe end;

[0045] 100. Arc-shaped clamp; 110. Slot; 200. Elastic part; 210. V-shaped steel sheet; 220. First connecting steel sheet; 230. Second connecting steel sheet; 240. Inclined steel sheet; 250. Third connecting steel sheet; 300. Clamp; 400. Tensioning structure; 410. First jack; 420. Second jack; 500. Laser positioning structure; 510. Laser emitter; 520. Laser receiver; 600. Tensioner; 700. Alignment piece; 800. High-temperature resistant gasket; 900. Fixing block. Detailed Implementation

[0046] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0047] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0048] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0049] In the description of this embodiment, the terms "upper," "lower," "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first" and "second" are used only for distinction in description and have no special meaning.

[0050] In this embodiment, the spigot refers to the end of the HDPE pipe end with an outer annular stepped surface, which is the welding surface. In this embodiment, an electrofusion wire is pre-installed on the welding surface; when the electrofusion wire is energized, it heats and melts the welding surface. The socket refers to the end of the HDPE pipe end with an inner annular stepped surface. The spigot is inserted into the socket, so that the outer annular stepped surface contacts the socket surface. When the electrofusion wire is energized, the inner annular stepped surface and the end face of the socket are fused together.

[0051] The following describes this embodiment in further detail, taking an HDPE pipe head with a spigot as the first HDPE pipe head 1 and an HDPE pipe head with a socket as the second HDPE pipe head 2.

[0052] like Figures 1 to 5 As shown, the auxiliary device for welding HDPE pipe ends in this embodiment includes multiple arc-shaped clamps 100, multiple elastic parts 200, clamps 300, tensioning structures 400, multiple sets of laser positioning structures 500, and a controller and alarm (not shown in the figure).

[0053] All the arc-shaped clamps 100 are distributed circumferentially along the socket of the HDPE pipe head (first HDPE pipe head 1). The arc-shaped clamps 100 are fixed to the inner wall of the socket, and there is a gap between two adjacent arc-shaped clamps 100. The elastic part 200 corresponds to the gap one by one, and the elastic part 200 crosses the corresponding gap and connects to the corresponding two adjacent arc-shaped clamps 100. The clamp 300 is arranged around the outer periphery of the socket and tightened by the tightener 600. The clamp 300 corresponds to the position of the arc-shaped clamp 100. The tensioning structure 400 is connected to the arc-shaped clamp 100 and is used to drive the arc-shaped clamp 100 to fit tightly against the inner wall of the socket. All the laser positioning structures 500 are arranged at intervals along the circumferential direction of the socket on the inner wall of the socket. The laser positioning structure 500 and the alarm are both connected to the controller.

[0054] This embodiment employs a split-type arc-shaped clamp 100 that fits snugly against the inner wall of the socket. Combined with the tightening effect of the external clamp 300 to limit deformation at the hot-melt position and the internal tensioning structure 400, multi-directional uniform fastening of the first HDPE pipe head 1 socket is achieved, effectively enhancing welding stability. The elastic part 200, while ensuring structural integrity, allows for a certain degree of deformation, preventing excessive deformation that could damage the electrofusion wire. When the electrofusion wire heats up, elastic deformation absorbs the radial expansion of the socket, thus adapting to changes in thermal expansion and contraction of the first HDPE pipe head 1 and avoiding stress concentration. The linkage between the laser positioning structure 500 and the alarm and controller enables precise alignment and real-time monitoring of the welding process, significantly improving welding accuracy and automation. The overall structure balances rigid constraints with flexible adjustment, offering significant advantages in improving welding quality, reducing operational difficulty, and minimizing human error.

[0055] In this embodiment, the arc-shaped clamp 100 is combined with the external clamp 300. With the assistance of the tensioning structure 400 and the laser positioning structure 500, the amount of thermal expansion deformation of the spigot can be reduced, thereby improving the fit of the electrofusion wire preset on the welding surface and thus improving the welding strength of the first HDPE pipe head 1.

[0056] Furthermore, such as Figure 1 and Figure 5 As shown, the arc-shaped clamp 100 has a groove 110 on the side opposite to the inner wall of the socket. The length of the groove 110 extends along the circumference of the arc-shaped clamp 100 and passes through both ends of the arc-shaped clamp 100.

[0057] like Figure 3 , Figure 7 and Figure 8As shown, the auxiliary device for welding HDPE pipe head (first HDPE pipe head 1) also includes multiple alignment pieces 700. The alignment pieces 700 correspond one-to-one with the gaps. One end of the alignment piece 700 extends into the slot 110 and is fixedly connected to the slot 110 of the corresponding arc-shaped clamp 100. The other end extends into the slot 110 of the corresponding adjacent arc-shaped clamp 100.

[0058] The two ends of the alignment piece 700 are inserted into the slots 110 of the corresponding arc-shaped clamps 100, and one end of the alignment piece 700 is fixedly connected to the corresponding arc-shaped clamp 100, while the other end is inserted into the slot 110 of another arc-shaped clamp 100. When the tensioning structure 400 drives the arc-shaped clamp 100 to deform with the spigot during the hot melt process, the alignment piece 700 can limit the two arc-shaped clamps 100 to avoid inconsistent deformation of the spigot area corresponding to the two arc-shaped clamps 100, which would affect the welding effect of the two HDPE pipe ends.

[0059] In this embodiment, there is an assembly gap between the two side walls of the slot 110 and the two sides of the alignment piece 700. The size of the assembly gap is such that the alignment piece 700 can move smoothly along the length direction of the slot 110 and the axial movement of the arc-shaped clamp 100 can be limited.

[0060] Furthermore, the auxiliary device for welding HDPE pipe ends also includes multiple high-temperature resistant gaskets 800. Each slot 110 contains a high-temperature resistant gasket 800. The high-temperature resistant gasket 800 extends along the length of the slot 110 and is fixed to the bottom of the slot 110. The alignment piece 700 is connected to the high-temperature resistant gasket 800.

[0061] For HDPE pipes, high temperatures are generated when the welded surfaces are heated and melted. The high-temperature resistant gasket 800 is placed in the groove 110 and covers the bottom of the groove 110. It can play a certain shaping role for the arc-shaped clamp 100 and prevent the arc-shaped clamp 100 from being deformed by heat, thus affecting the restraint effect on the deformation of the spigot.

[0062] Furthermore, the tensioning structure 400 includes multiple first jacks 410, each first jack 410 corresponding to a gap, and each first jack 410 is connected to two adjacent arc-shaped clamps 100 and adjacent to the corresponding gap.

[0063] The first jack 410, as a mechanical lifting device, can generate a huge and precise thrust. In this embodiment, one first jack 410 is set for each gap, and the first jack 410 is connected to two adjacent arc-shaped clamps 100. When the first jack 410 is pushed out, it directly and effectively pushes the two arc-shaped clamps 100 outward along the radial direction of the socket, thereby ensuring that the entire arc-shaped clamp 100 can be tightly fitted to the inner wall of the socket with sufficient pressure, preventing the pipe head from loosening or shifting during welding. This embodiment adopts a layout of multiple first jacks 410 corresponding to each gap, so that the tensioning force can be evenly and continuously distributed on all the arc-shaped clamps 100, avoiding the problem of arc-shaped clamps 100 twisting or excessive local stress in the socket that may be caused by single-point force application, forming a stable and self-balancing support system; the first jack 410 combined with the alignment plate 700 to form a circumferential rigid frame forms a rigid and flexible strong support structure inside the socket.

[0064] Specifically, the two ends of the first jack 410 are fixed in the slots 110 of the arc-shaped clamp 100 by fixing blocks 900. For example, a fixing block 900 is welded to each of the two adjacent arc-shaped clamps 100 at the corresponding gaps, and the two ends of the first jack 410 are fixed to the fixing blocks 900. After the two HDPE pipe ends are welded, the fixing blocks 900 can be cut off to complete the disassembly of the first jack 410.

[0065] The auxiliary device for HDPE pipe welding in this embodiment integrates powerful tensioning force, precise deformation correction capability, uniform force distribution, and reliable safety self-locking, fundamentally solving the industry pain points of unstable fixing, inaccurate alignment, and poor stability of HDPE pipe ends during butt welding. It is an important guarantee for achieving high quality and high reliability in HDPE pipe welding.

[0066] Furthermore, there are two arc-shaped clamps 100; the tensioning structure 400 also includes a second jack 420, which is connected to the circumferential center of the two arc-shaped clamps 100 and extends radially along the socket.

[0067] In this embodiment, two arc-shaped clamps 100 are used, allowing for smooth installation onto the inner wall of the socket. Compared to using more arc-shaped clamps 100, this reduces installation time. The second jack 420 extends radially along the socket and connects circumferentially with the center of the two arc-shaped clamps 100, making the two first jacks 410 symmetrically distributed relative to the second jack 420. The second jack 420 serves as the main tensioning force source, directly applying a large, directional expansion force along the radial centerline of the two arc-shaped clamps 100. This ensures that the entire clamp system can overcome maximum resistance, generate sufficient positive pressure against the inner wall of the socket, and provides roundness correction capability, ensuring the alignment accuracy and connection strength of HDPE pipe head welding under large-diameter, high-requirement conditions.

[0068] In this embodiment, the two ends of the second jack 420 are fixedly connected to the slots 110 of the arc-shaped clamp 100 via fixing blocks 900. After the HDPE pipe head is welded, the second jack 420 can be disassembled by cutting off the fixing blocks 900.

[0069] Furthermore, each laser positioning structure 500 includes a laser emitter 510 and a laser receiver 520 mounted on the inner wall of the socket, with the line connecting the laser emitter 510 and the laser receiver 520 extending radially along the socket.

[0070] In this embodiment, the laser emitter 510 and the laser receiver 520 are arranged such that the laser beam emitted by the laser emitter 510 extends radially along the socket, and the laser receiver 520 receives the laser beam. The laser emitter 510 and the laser receiver 520 are used together to detect the inner diameter of the socket. If the detected inner diameter deviates from the standard value by more than ±1mm, an alarm is triggered and the welding process is paused. This triggers the controller to activate the alarm and disconnect the power to the fuse.

[0071] Furthermore, multiple sets of laser positioning structures 500 are evenly distributed on the inner wall of the socket to improve detection accuracy.

[0072] Furthermore, the elastic part 200 includes a V-shaped steel sheet 210 and two first connecting steel sheets 220 connected to both ends of the V-shaped steel sheet 210 (e.g., Figure 6 The first connecting steel plate 220 extends from the end away from the V-shaped steel plate 210 into the slot 110 and is welded and fixed to the corresponding arc-shaped clamp 100.

[0073] In this embodiment, the V-shaped steel sheet 210 acts like a pre-compressed spring, possessing excellent elasticity and deformation capacity. When the two arc-shaped clamps 100 require slight relative displacement due to external forces (such as the tightening of the clamp 300, the action of the tensioning structure 400, or the thermal expansion and contraction of the pipeline), the opening angle of the V-shaped steel sheet 210 can change accordingly (opening or closing), efficiently absorbing and releasing energy, preventing the structure from jamming due to over-constraint or generating excessive internal stress. The two first connecting steel sheets 220 serve as "transition arms," ​​with one end firmly connected to the V-shaped steel sheet 210 (which can be welded or bent into shape), and the other end directly extending and welded into the groove 110. The welding method creates an extremely strong and permanent connection without the risk of loosening. This design shifts the fixing point of the elastic part 200 from the edge of the clamp to the more robust groove 110 structure, utilizing the reinforcing rib effect of the groove 110 to greatly improve the stiffness and strength of the connection point, avoiding the risk of tearing or loosening at the connection under repeated deformation. Therefore, the elastic part 200 in this embodiment adopts this structural design, which ensures a rigid connection with the arc-shaped clamp 100 while also providing an elastic buffering effect.

[0074] Furthermore, such as Figure 7 and Figure 8 As shown, the elastic part 200 includes a second connecting steel plate 230, two inclined steel plates 240 at an angle, and two third connecting steel plates 250 corresponding to the inclined steel plates 240. The ends of the two inclined steel plates 240 that are close to each other are connected by the second connecting steel plate 230. The ends of the two inclined steel plates 240 that are away from the second connecting steel plate 230 are respectively connected to a corresponding third connecting steel plate 250. The end of the third connecting steel plate 250 that is away from the inclined steel plate 240 extends into the corresponding slot 110 and is welded and fixed to the corresponding arc-shaped clamp 100.

[0075] Compared with the elastic part 200 in the above embodiments, the elastic part 200 of this embodiment can achieve both rigid connection with the arc-shaped clamp 100 and elastic buffering effect. By adding a first connecting piece, the structural strength of the elastic part 200 of this embodiment can be improved.

[0076] Furthermore, the distance between the clamp 300 and the welding surface of the socket is less than 0.2m, and the laser positioning structure 500 is adjacent to the arc-shaped clamp 100 and located on the side of the arc-shaped clamp 100 facing the welding surface.

[0077] In this embodiment, the clamp 300 is installed at a very close position, less than 0.2 meters from the welding surface. This means that its strong binding force acts directly on the foremost and most easily deformed area of ​​the joint. Under the "double-pronged" action of the internal tensioning structure 400 and the external clamp 300, the end of the joint is firmly locked, effectively preventing deformation of the joint due to pressure and heat during welding, especially during hot-melt butt welding. This ensures the flatness and roundness of the butt joint surface, laying a solid foundation for forming a uniform, high-quality weld ring. The laser positioning structure 500 is installed on the side adjacent to the arc-shaped clamp 100 and facing the welding surface, making the laser positioning structure 500 even closer to the welding surface. During the butt welding process, if any eccentricity caused by deformation occurs, the controller will immediately trigger the alarm, ensuring high positioning accuracy.

[0078] This embodiment also provides a method for welding HDPE pipe ends, which utilizes the auxiliary device for welding HDPE pipe ends described in the above embodiment. The HDPE pipe end welding method includes:

[0079] A first HDPE pipe head 1 with a spigot and a second HDPE pipe head 2 with a socket are provided. Multiple arc-shaped clamps 100 are fixed circumferentially on the inner wall of the spigot of the first HDPE pipe head 1, and a gap is made between two adjacent arc-shaped clamps 100.

[0080] An elastic part 200 is provided for each gap, and the two corresponding arc-shaped clamps 100 are fixedly connected to the elastic part 200.

[0081] A clamp 300 is provided on the outer wall of the socket of the first HDPE pipe head 1, adjacent to the welding surface, and tightened by a tightener 600;

[0082] An expansion structure 400 connected to an arc-shaped clamp 100 is installed inside the socket of the first HDPE pipe head 1.

[0083] Insert the spigot of the first HDPE pipe head 1 into the socket of the second HDPE pipe head 2, and use the laser positioning structure 500 to position and calibrate the alignment of the spigot and the socket. Then, energize the electrofusion wire embedded in the welding surface of the first HDPE pipe head 1 to make the two first HDPE pipe heads 1 and the second HDPE pipe head 2 connected.

[0084] During the docking process, if the inner diameter deviation of the first HDPE pipe head 1 detected by the laser positioning structure 500 exceeds ±1mm, the controller will control the alarm to issue an alarm signal, suspend the welding, and adjust the tensioning structure 400 until the inner diameter deviation detected by the laser positioning structure 500 does not exceed ±1mm.

[0085] This embodiment breaks through the traditional model of pipe joint welding that relies on preliminary preparation and manual experience, and establishes a real-time quality monitoring system. Real-time monitoring is achieved during the insertion and fusion processes of the first HDPE pipe joint 1. Once the laser detects that the inner diameter deviation of the first HDPE pipe joint 1 exceeds the threshold of ±1mm, the controller will immediately alarm and suspend the fusion process, preventing "defective welding" under misalignment and avoiding the generation of substandard welds at the source. When the detected inner diameter deviation exceeds ±1mm, the controller immediately controls the tensioning structure 400 to adjust the tension force, actively correcting the roundness and position of the joint until it meets the standard.

[0086] Furthermore, multiple high-temperature resistant gaskets 800 corresponding one-to-one with the number of arc-shaped clamps 100 and multiple alignment pieces 700 corresponding one-to-one with the gaps are provided. The high-temperature resistant gaskets 800 are fixed to the bottom of the grooves 110 of the arc-shaped clamps 100, and the two ends of the alignment pieces 700 are inserted into the grooves 110 of two adjacent arc-shaped clamps 100. Then, one end of the alignment piece 700 is welded and fixed to the corresponding arc-shaped clamp 100 or the high-temperature resistant gasket 800.

[0087] The HDPE pipe head welding method described in this embodiment significantly improves welding quality: the thermal expansion deformation of the spigot can be controlled to ≤0.5%, the electrofusion wire fit deviation is <1mm, and the tensile strength of the welded joint (pipe head) is increased by 30%-40%. It also optimizes construction efficiency: the split clamp design shortens installation time to 10-15 minutes (compared to over 30 minutes with traditional clamps), and the laser positioning structure effectively reduces manual adjustment time, compressing the single welding cycle to 2-3 hours (compared to 4-6 hours with traditional processes). Furthermore, it offers cost and safety advantages: it avoids rework due to incomplete welding, reduces material waste, reduces the frequency of workers entering the pipe, lowers the risk of working in confined spaces, is compatible with HDPE pipes of diameters from 2.5 to 4.5 meters, and has a high equipment reuse rate.

[0088] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art will be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. An auxiliary device for welding HDPE pipe ends, characterized in that, include: Multiple arc-shaped clamps are provided, all of which are distributed circumferentially along the socket of the HDPE pipe head. The arc-shaped clamps are fitted and fixed to the inner wall of the socket, and there is a gap between two adjacent arc-shaped clamps. Multiple elastic parts are provided, each elastic part corresponding to a gap, and each elastic part crosses the corresponding gap and is connected to the corresponding two adjacent arc-shaped clamps. A clamp is provided around the outer periphery of the insertion port and tightened by a tightener, and the position of the clamp corresponds to that of the arc-shaped clamp. A tensioning structure is provided, which is connected to the arc-shaped clamp and is used to drive the arc-shaped clamp to fit tightly against the inner wall of the insertion port. Multiple sets of laser positioning structures are provided, all of which are spaced apart along the circumferential direction of the socket on the inner wall of the socket. The controller and the alarm are both connected to the controller.

2. The auxiliary device for welding HDPE pipe ends according to claim 1, characterized in that, The arc-shaped clamp has a groove on the side opposite to the inner wall of the socket, and the length of the groove extends along the circumference of the arc-shaped clamp and passes through both ends of the arc-shaped clamp. The auxiliary device for welding HDPE pipe ends also includes multiple alignment pieces, each of which corresponds to a gap. One end of each alignment piece extends into the slot and is fixedly connected to the slot of the corresponding arc-shaped clamp, while the other end extends into the slot of another adjacent arc-shaped clamp.

3. The auxiliary device for welding HDPE pipe ends according to claim 2, characterized in that, It also includes multiple high-temperature resistant gaskets, with one high-temperature resistant gasket in each slot. The high-temperature resistant gasket extends along the length of the slot and is fixed to the bottom of the slot. The alignment piece is connected to the high-temperature resistant gasket.

4. The auxiliary device for welding HDPE pipe ends according to claim 2, characterized in that, The tensioning structure includes multiple first jacks, each of which corresponds to a gap. Each first jack is connected to two adjacent arc-shaped clamps and is close to the corresponding gap.

5. The auxiliary device for welding HDPE pipe ends according to claim 4, characterized in that, The number of the arc-shaped clamps is two; the tensioning structure also includes a second jack, which is connected to the circumferential center of the two arc-shaped clamps and extends radially along the insertion port.

6. The auxiliary device for welding HDPE pipe ends according to any one of claims 1 to 5, characterized in that, Each set of laser positioning structures includes a laser emitter and a laser receiver mounted on the inner wall of the socket, with the line connecting the laser emitter and the laser receiver extending radially along the socket.

7. The auxiliary device for welding HDPE pipe ends according to any one of claims 2 to 5, characterized in that, The elastic part includes a V-shaped steel sheet and two connecting steel sheets connected to both ends of the V-shaped steel sheet. The end of each connecting steel sheet away from the V-shaped steel sheet extends into the slot and is welded and fixed to the corresponding arc-shaped clamp; or, The elastic part includes a first connecting steel plate, two inclined steel plates at an angle, and two second connecting steel plates corresponding to the inclined steel plates. The ends of the two inclined steel plates that are close to each other are connected by the first connecting steel plate, and the ends of the two inclined steel plates that are away from the first connecting steel plate are respectively connected to a corresponding second connecting steel plate. The end of the second connecting steel plate that is away from the inclined steel plate extends into the corresponding slot and is welded and fixed to the corresponding arc-shaped clamp.

8. The auxiliary device for welding HDPE pipe ends according to any one of claims 1 to 5, characterized in that, The distance between the clamp and the welding surface of the socket is less than 0.2m, and the laser positioning structure is adjacent to the arc-shaped clamp and located on the side of the arc-shaped clamp facing the welding surface.

9. A method for welding HDPE pipe ends, characterized in that, The HDPE pipe end welding method, using the auxiliary device for welding HDPE pipe ends according to any one of claims 1 to 8, comprises: A first HDPE pipe end with a spigot and a second HDPE pipe end with a socket are provided. Multiple arc-shaped clamps are fixed circumferentially on the inner wall of the spigot of the first HDPE pipe end, and a gap is made between two adjacent arc-shaped clamps. An elastic part is provided for each gap, and the two corresponding arc-shaped clamps are fixedly connected to the elastic part; A clamp is installed on the outer wall of the socket of the first HDPE pipe head, adjacent to the welding surface, and tightened by a tightener; An expansion structure connected to the arc-shaped clamp is installed inside the socket of the first HDPE pipe head; Insert the socket of the first HDPE pipe head into the socket of the second HDPE pipe head, and use a laser positioning structure to position and calibrate the alignment of the socket and the socket. Then, energize the electrofusion wire embedded in the welding surface of the first HDPE pipe head to connect the two first HDPE pipe heads and the second HDPE pipe head. During the docking process, if the inner diameter deviation of the first HDPE pipe head detected by the laser positioning structure exceeds ±1mm, the controller controls the alarm to issue an alarm signal, suspends the welding, and adjusts the tensioning structure until the inner diameter deviation detected by the laser positioning structure does not exceed ±1mm.

10. The HDPE pipe head welding method according to claim 9, characterized in that, Provide multiple high-temperature resistant gaskets corresponding one-to-one with the number of the arc-shaped clamps and multiple alignment pieces corresponding one-to-one with the gaps. Fix the high-temperature resistant gaskets to the bottom of the grooves of the arc-shaped clamps, and insert both ends of the alignment pieces into the grooves of two adjacent arc-shaped clamps. Then, weld one end of the alignment piece to the corresponding arc-shaped clamp or the high-temperature resistant gasket.

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