Electric hot welding machine for thermal insulation pipe joint

Abstract

The present application relates to the technical fields of heat-melting welding of thermal insulation pipe, and particularly discloses a heat-melting welding machine for thermal insulation pipe joint; the heat-melting welding machine is matched with a welding auxiliary frame; the welding auxiliary frame comprises an adjusting base, two circular rail frames, two rotating rings which are coaxially installed on the two circular rail frames, a pressing roller mechanism comprising four driving assemblies, a plurality of pressing roller pieces which are horizontally installed between two driving assemblies in opposite positions on the two rotating rings, two fastening mechanisms which are assembled on the two circular rail frames, and two groups of air heaters which are assembled on the two rotating rings; the welding auxiliary frame is matched with the heat-melting welding machine, has high integration, meets various operations before and after heat-melting welding of the outer protective layer of the thermal insulation pipe, is convenient to operate, can improve the standardization and normalization of the welding operation of the thermal insulation pipe, ensures the welding forming quality, and improves the uniformity of the quality.

Description

Technical Field

[0001] This invention relates to the field of thermal insulation pipe hot melt welding technology, and specifically proposes an electrothermal welding machine for thermal insulation pipe joints. Background Technology

[0002] Insulated pipes are pipe products with thermal insulation functions. They are mainly used to transport high-temperature or low-temperature media (such as hot water, steam, cold air, oil, natural gas, etc.). By reducing the heat or cold loss of the media during transportation, they achieve the purpose of energy saving and consumption reduction.

[0003] Insulated pipes generally consist of a medium pipe, an insulation layer, and an outer protective layer distributed from the inside out. For insulated pipes where the medium pipe or the outer protective layer is made of thermoplastic plastic, electrofusion welding is suitable for joining two insulated pipes. Compared with thermofusion welding between medium pipes, thermofusion welding between outer protective layers is more complex and has higher requirements.

[0004] In the current technology, when performing hot-melt welding on the outer sheath of the insulation pipe, a hot-melt sleeve is used to overlap the two ends of the outer sheath of the insulation pipe. The two overlaps need to be externally tightened sequentially. To improve the stability of the hot-melt sleeve, it is usually necessary to further tighten the position between the two ends of the hot-melt sleeve manually. Hot-melt welding is then performed on the tightened and fixed foundation. After the hot-melt welding is completed, heat-shrink tape is needed at the two ends of the hot-melt sleeve and at its overlap joints to further improve the overall sealing performance of the welded hot-melt sleeve. All of the above operations rely primarily on manual labor. The process involves manual, piecemeal operations with scattered tools. Furthermore, the heating of the heat-shrinkable tape is primarily done manually using non-flame heating devices like hot air blowers to heat it around the tape. This is inconvenient for manual operation, and the single-point heating results in uneven heat distribution around the tape, affecting the quality of the heat-shrink seal. The heating speed, achieved manually, is also difficult to control. In summary, under current technology, the hot-melt welding process for the outer protective layer of insulation pipes suffers from a lack of standardization and normalization, impacting weld quality and sealing performance, and increasing the probability of rework and repairs after seal inspection. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides an electrofusion welding machine for insulated pipe joints, which solves the problems mentioned in the background section.

[0006] To achieve the above objectives, the present invention employs the following technical solution: an electrofusion welding machine for insulated pipe joints, comprising a hot melt welding machine and a welding auxiliary frame therewith, the welding auxiliary frame comprising: an adjusting base; two circular rail frames, horizontally coaxially arranged and oppositely mounted on the adjusting base; the circular rail frames having a vertically split structure; the adjusting base being capable of driving the two circular rail frames to synchronously separate and move and to move relative to each other axially; two rotating rings, corresponding one-to-one and coaxially rotatably mounted on the two circular rail frames; the rotating rings having a split structure; and a pressure roller mechanism comprising four rollers corresponding one-to-one mounted on the four halves of the two rotating rings. The structure includes a disconnected drive assembly; multiple pressure rollers are horizontally mounted between the two drive assemblies in relative positions on the two rotating rings, with all pressure rollers distributed circumferentially around the rotating rings; multiple pressure rollers are used to synchronously adjust the distance between them and the center of the rotating rings under the combined drive of the two drive assemblies; the pressure rollers have an axially contracting structure; two fastening mechanisms are mounted one-to-one on two circular rail frames for corresponding fastening of the two heat fusion joint ends of the insulation pipe; and two sets of hot air blowers are mounted one-to-one on the two rotating rings; in each set, multiple hot air blowers are circumferentially distributed and fixed on the rotating rings, with the hot air blower outlets facing the center of the rotating rings.

[0007] Preferably, the adjusting base includes a base plate, on which two guide rails are horizontally and relatively slidably mounted; two circular rail frames are correspondingly assembled on the two guide rails, and two half-broken structures in the circular rail frames are relatively slidably mounted on the guide rails in a direction perpendicular to the sliding direction of the guide rails; a double-headed telescopic rod is assembled between the two half-broken structures in the two circular rail frames at their axially opposite positions, and the double-headed telescopic rod is fixed to the half-broken structures of the two circular rail frames through two telescopic ends.

[0008] Preferably, the driving assembly includes an arc-shaped plate coaxially arranged and rotary driven on the rotating ring; multiple slide rails are fixedly distributed circumferentially on the split structure of the rotating ring, and sliding blocks are slidably installed on each slide rail, with a connecting rod hinged between each sliding block and the arc-shaped plate; a pressure roller is horizontally rotatably installed between two sliding blocks located in opposite positions axially on the rotating ring.

[0009] Preferably, the pressure roller component includes two horizontally symmetrically arranged pressure rollers that are rotatably mounted on two sliding blocks in a one-to-one correspondence, and the two pressure rollers are elastically connected and slidably fitted with a spline shaft.

[0010] Preferably, the fastening mechanism includes a guide frame fixed to one of the split structures in the circular rail frame, a tightening frame that moves toward the center of the rotating ring and is adjusted, a fastening belt that provides tightening adjustment is mounted on the tightening frame, and one end of the fastening belt is detachably mounted on the tightening frame.

[0011] Preferably, the tightening frame includes a roller frame slidably mounted on a guide frame, on which a take-up roller is horizontally rotatably mounted; one end of the fastening belt is fixed to the take-up roller, and the other end is fixed to a belt shaft; a bayonet is provided on the roller frame, and the belt shaft is snapped into the bayonet.

[0012] Preferably, the pressure roller has a stepped roller structure consisting of two roller segments with different diameters, and the roller segment with the larger diameter is arranged close to the sliding block.

[0013] Preferably, the rotating ring is provided with a toothed ring.

[0014] Preferably, the air outlet end of the hot air blower is equipped with a flattened air outlet hood with a rectangular structure, and the long side of the flattened air outlet hood is axially arranged along the rotation ring.

[0015] The above technical solution has the following advantages or beneficial effects: This invention provides an electrofusion welding machine for insulated pipe joints, equipped with a welding auxiliary frame that works in conjunction with existing electrofusion welding machines. It is specifically designed for pre- and post-weld operations of electrofusion welding the outer sheath of insulated pipes. The circular rail frame and rotating rings in the welding auxiliary frame are designed with a detachable structure to facilitate the handling of the insulated pipe. The circular rail frame is equipped with a fastening mechanism that allows for easy clamping at the two electrofusion ports of the electrofusion sleeve. An adjustable pressure roller mechanism is installed between the rotating rings to provide uniformly distributed external clamping support to the outside of the electrofusion sleeve. Together with the fastening mechanism, this ensures the stability of the electrofusion sleeve overlap and allows for... Roller pressing and shaping are performed on the heat-melted area to facilitate operation. In the heating and sealing process of the heat-shrinkable tape, a rotating ring drives a uniformly distributed hot air blower and pressure rollers to automatically rotate around the heat-shrinkable tape, ensuring the uniformity of circumferential heating and distribution for uniform shrinkage. The synchronous rolling operation of the pressure rollers improves the tightness of the fit between the shrinkable tape and the heat-melted sleeve. In summary, the welding auxiliary frame provided in this invention is highly integrated, meeting various operations before and after the heat-melted welding of the outer protective layer of the insulation pipe. It is convenient to operate, improves the standardization and normalization of the welding operation of the insulation pipe, and improves the uniformity of quality while ensuring the quality of the welded shape, thus avoiding rework. Attached Figure Description

[0016] The invention, its features, shape, and advantages will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings. Like reference numerals denote like parts throughout the drawings, which are not intentionally drawn to scale; the focus is on illustrating the spirit of the invention.

[0017] Figure 1 This is a three-dimensional structural schematic diagram of an electrofusion welding machine for insulated pipe joints provided by the present invention.

[0018] Figure 2 This is a three-dimensional structural diagram of the welding auxiliary frame.

[0019] Figure 3 This is a side view of the welding auxiliary frame.

[0020] Figure 4 It is a three-dimensional structural diagram of the assembly of the circular rail frame and the adjustment base.

[0021] Figure 5 It is a three-dimensional structural diagram of two half-broken structures in relative positions in two rotating rings, a set of pressure rollers, and two drive components assembled together.

[0022] Figure 6 It is a three-dimensional structural diagram of a set of pressure rollers and two drive components assembled together.

[0023] Figure 7 It is a three-dimensional structural diagram of the halved structure of the circular rail frame, the halved structure of the rotating ring, and the assembly of the fastening mechanism.

[0024] Figure 8 yes Figure 7 A magnified view of a portion of point A in the middle.

[0025] Figure 9 This is a diagram showing the working state of a hot melt welding machine when hot melt welding an insulation pipe.

[0026] Figure 10 It is a three-dimensional structural diagram of the two insulation pipes after hot-melt welding and heat sealing with heat shrink tape.

[0027] In the diagram: 1. Adjustable base; 11. Base plate; 12. Guide rail; 13. Double-headed telescopic rod; 131. Bushing block; 132. Spline rod; 14. Double-direction lead screw; 2. Circular rail frame; 21. Circular guide rail; 22. Base foot; 3. Rotating ring; 31. Gear ring; 32. Rotating part; 33. Radial plate; 4. Pressure roller mechanism; 41. Drive assembly; 411. Electric push rod; 412. Arc plate; 413. Slide rail; 414. Sliding block; 415. Connecting rod; 42. Pressure roller; 421. Pressure roller; 422. Splined shaft; 423. Tension spring; 5. Fastening mechanism; 51. Guide frame; 52. Roller frame; 521. Bayonet; 522. Screw; 53. Take-up roller; 54. Transition roller; 55. Fastening belt; 56. Belt shaft; 6. Hot air blower; 61. Flattened air outlet cover; 7. Hot melt welding machine; 81. Insulation pipe; 811. Medium pipe; 812. Insulation layer; 813. Outer protective layer; 82. Hot melt sleeve; 83. Heat shrink tape. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0030] like Figure 1 , Figure 3 and Figure 9 As shown, an electrofusion welding machine for insulated pipe joints includes a hot melt welding machine 7 and a welding auxiliary frame that works in conjunction with it. In this invention, with the assistance of the welding auxiliary frame, the hot melt welding machine 7 mainly welds the outer protective layer 813 when two insulated pipes 81 are joined together. The hot melt welding machine 7 is an existing welding machine for performing electrofusion welding. The insulated pipe 81 includes, from the inside out, a medium pipe 811, an insulation layer 812, and an outer protective layer 813. The insulation layer 812 is mostly a polyurethane foam layer or other insulation filling layer, and the outer protective layer 813 is basically made of thermoplastic plastic.

[0031] like Figure 1 , Figure 2 , Figure 3 and Figure 4 As shown, the welding auxiliary frame includes an adjustable base 1; the adjustable base 1 includes a base plate 11, and for easy movement, casters can be installed at the bottom of the base plate 11; two guide rails 12 are horizontally slidably mounted on the base plate 11; each of the two guide rails 12 is equipped with a circular rail frame 2, the circular rail frame 2 includes a circular guide rail 21 and a foot 22 welded to the circular guide rail 21, the two circular rail frames 2 are horizontally coaxially symmetrically arranged, and the foot 22 is slidably mounted on the guide rail 12. In order to facilitate the hoisting and removal of the insulation pipe 81 that has been welded and joined from the welding auxiliary frame, the circular rail frame 2 has a vertically split structure. The guide rail 12 plays a role in assembling the two split structures of the circular rail frame 2, and the sliding direction of the circular rail frame 2 on the guide rail 12 is perpendicular to the sliding direction of the guide rail 12 on the base plate 11.

[0032] like Figure 1 , Figure 2 , Figure 3 and Figure 4As shown, a double-headed telescopic rod 13 is assembled between the two half-disconnected structures located at their axially opposite positions in the two circular rail frames 2. The double-headed telescopic rod 13 includes a bushing block 131 and two splined rods 132. Two symmetrically arranged bushings are provided in the bushing tube. The two splined rods 132 are correspondingly and slidably assembled in the two bushings of the bushing block 131 by keying. One end of each splined rod 132 is fixed to the base foot 22 by bolts. In order to realize the synchronous disconnection and separation operation of the two circular rail frames 2, two bearings with seats are horizontally rotatably mounted on the base plate 11. The two-way lead screw 14 has two corresponding threaded sleeve blocks 131 of the two double-headed telescopic rods 13 installed on the two threaded sections of the two-way lead screw 14. In this embodiment, the two-way lead screw 14 is preferably driven by a motor, and can also be manually rotated. In addition, in order to adjust the distance between the two circular rail frames 2, two lead screws can also be rotatably installed on the base through bearing seats, and the two lead screws are installed on the two guide rails 12 with corresponding threaded connections. In actual operation, the adjustment range of the distance between the two circular rail frames 2 is small, so the lead screw can be adjusted by manual rotation.

[0033] like Figure 4 , Figure 5 and Figure 7 As shown, each of the two circular rail frames 2 is equipped with a rotating ring 3. Both ends of the rotating ring 3 are provided with a rotating part 32 arranged concentrically and in a circular structure. The rotating ring 3 is coaxially mounted on the circular guide rail 21 through the rotating part 32 at one end. In order to match the structure of the circular rail frame 2, the rotating ring 3 is in a split structure. When the circular rail frame 2 needs to be separated, the rotating ring 3 needs to be rotated and adjusted so that the two split structures of the rotating ring 3 are independently distributed on the two split structures of the circular rail frame 2. Then, the two double-headed telescopic rods 13 can be driven by the bidirectional screw 14 to separate the circular rail frame 2, and the rotating ring 3 will also separate. The rotating ring 3 is equipped with a gear ring 31. In order to achieve synchronous rotation drive of the two rotating rings 3, a drive motor (not shown in the figure) can be fixedly installed on the half-disconnected structure on the same side of the two circular rail frames 2. The output shaft of the drive motor is fixed with a gear that meshes with the gear ring 31. The two drive motors maintain synchronous control. Multi-motor synchronous control is existing technology and will not be described in detail here. When the circular rail frame 2 is in the non-disconnected state, the two rotating rings 3 maintain synchronous rotation on the circular guide rail 21 through synchronous drive of the two drive motors.

[0034] like Figure 2 , Figure 3 , Figure 5 and Figure 6As shown, a pressure roller mechanism 4 is assembled between the two rotating rings 3 and rotates synchronously therewith. The pressure roller mechanism 4 includes four drive components 41, each corresponding to one of the four split structures of the two rotating rings 3. The drive components 41 include an electric push rod 411, an arc plate 412, four slide rails 413, four sliding blocks 414, and four connecting rods 415. The arc plate 412 is distributed at both ends of the rotating ring 3 relative to the circular guide rail 21, and is coaxially mounted on the rotating part 32 at one end of the rotating ring 3. The electric push rod 411 is hinged to the split structure of the rotating ring 3, and the output end of the electric push rod 411 is hinged to the arc plate 412. Eight circumferentially evenly distributed... The radial plates 33 of the cloth and the two half-broken structures of the rotating ring 3 each have four radial plates 33 distributed on each side; four slide rails 413 are fixed to the corresponding four radial plates 33 by bolts, and four sliding blocks 414 are slidably installed on the four slide rails 413 one by one, and the sliding blocks 414 slide radially along the rotating ring 3 in the slide rails 413; one end of each of the four connecting rods 415 is hinged to the four sliding blocks 414 one by one, and the other end of each of the four connecting rods 415 is hinged to the arc plate 412; pressure rollers 42 are horizontally rotatably installed between two sliding blocks 414 located in opposite positions in the axial direction of the rotating ring 3, for a total of eight pressure rollers 42, and the eight pressure rollers 42 are evenly distributed in the circumferential direction of the rotating ring 3. The pressure roller component 42 includes two horizontally symmetrically arranged pressure rollers 421 that are rotatably mounted on two sliding blocks 414. The pressure rollers 421 have a tubular structure with one end open. The two pressure rollers 421 are connected by a key and a spline shaft 422 is slidably mounted together. A tension spring 423 is welded between the two pressure rollers 421. In order to cooperate with the subsequent shrinking and pressing operation of the shrinkage belt, the pressure rollers 421 have a stepped circular roller structure composed of two circular roller segments with different diameters. The larger diameter circular roller segment is arranged close to the sliding block 414. The radius difference between the two circular roller segments on the pressure roller 421 is slightly smaller than the thickness of the shrinkage belt.

[0035] Activating the electric push rod 411 can drive the arc plate 412 to rotate along the rotating part 32, and then push the sliding block 414 to slide along the slide rail 413 through the connecting rod 415, thereby adjusting the distance between the pressure roller 42 and the center of the rotating ring 3; the pressure roller 42 adopts a telescopic structure design, so that it can be used with two circular rail frames 2 for width adjustment.

[0036] like Figure 2 , Figure 7 and Figure 8As shown, before hot-melt welding, in order to secure the two ends of the hot-melt sleeve 82 to the ends of the outer protective layer 813 of the two insulation pipes 81, fastening mechanisms 5 are respectively installed on the half-splitting structures on the same side of the two circular rail frames 2; the fastening mechanism 5 includes a guide frame 51 welded to the half-splitting structure of the circular guide rail 21, the guide frame 51 being arranged close to the upper split end of the circular guide rail 21; a roller frame 52 is vertically slidably mounted on the guide frame 51, and a screw 522 is vertically rotatably mounted on the top of the roller frame 52 via a bearing, the screw 52... 2. The threaded connection is installed on the guide frame 51; the take-up roller 53 and the transition roller 54 are horizontally rotatably mounted on the roller frame 52; one end of the fastening band 55 is glued and fixed to the take-up roller 53, the fastening band 55 passes around the transition roller 54, and the other end is glued to the belt shaft 56; the roller frame 52 is provided with an L-shaped bayonet 521. In this embodiment, the belt shaft 56 is a round shaft structure with the same radius as the transition roller 54, and both ends of the belt shaft 56 are provided with snap-fit ​​shafts that cooperate with the bayonet 521 and are in the form of square shafts. The belt shaft 56 is snapped into the bayonet 521 through the snap-fit ​​shafts. In this embodiment, in order to facilitate direct manual feeling of the force when the fastening tape 55 is tightened, the take-up roller 53 can be manually rotated for winding, and a locking nut can be threaded onto the shaft of the take-up roller 53 so that after the fastening tape 55 is tightened, it is pressed against the roller frame 52 by the nut, thus indirectly locking the take-up roller 53. Of course, other methods can be selected to lock the take-up roller 53, such as using the cooperation of a positioning pin and a positioning hole.

[0037] like Figure 2 , Figure 3 , Figure 5 and Figure 7 As shown, in order to facilitate uniform heating of the heat shrinkable tape 83, four hot air blowers 6 are respectively installed on each of the two rotating rings 3, and the four hot air blowers 6 are evenly distributed in the circumference; and the air outlet of the hot air blower 6 is set towards the center of the rotating ring 3. In order to ensure the covering heating effect in the width direction of the heat shrinkable tape 83, the air outlet end of the hot air blower 6 is equipped with a rectangular flattened air outlet hood 61, and the long side of the flattened air outlet hood 61 is set along the axial direction of the rotating ring 3. It should be noted that in this invention, the hot air blower 6 is only equipped with a resistance wire that provides a heat source. Each hot air blower 6 is provided with an air inlet, and is also equipped with a blower (not shown in the figure) for unified air supply. Specifically, blowers can be installed on both rotating rings 3 by means of a fixing bracket so that the blowers can rotate with the rotating rings 3. The air outlet of the blower can be connected to an air pipe, and the air pipe can be further connected to the air inlets of the four hot air blowers 6 through four branch pipes. The blower blows air and heats it with the resistance wire to discharge hot air. The temperature of the exhaust air can be controlled by the resistance wire. In actual construction, the temperature of the hot air is sufficient to cause the heat shrinkable tape 83 to shrink and deform.

[0038] This invention provides an electrofusion welding machine for insulated pipe joints. During the butt welding operation of the insulated pipe 81, the welding auxiliary frame mainly cooperates with the electrofusion welding machine 7 to complete the electrofusion welding of the outer protective layer 813. (See reference...) Figures 1 to 10 As shown, the specific process is as follows.

[0039] Before welding, place the welding auxiliary frame upright on the ground and adjust the circular rail frame 2 to the disconnected state. Then, hoist the insulation pipe 81 to be joined to the welding operation area using hoisting equipment. The insulation pipe 81 can be placed horizontally on the positioning support frame, with the ends of the two insulation pipes 81 to be joined located between the two halves of the circular rail frame 2. Here, the positioning support frame is a tooling frame specifically used to support and position the insulation pipe 81, and the tooling frame can adjust the placement height of the insulation pipe 81. During the installation process, the height of the insulation pipe 81 needs to be adjusted using the positioning support frame, and the position of the welding auxiliary frame also needs to be adjusted so that the insulation pipe 81 is basically in the middle of the two half-broken structures in the circular rail frame 2, and the central axis of the insulation pipe 81 is at the same height as the half-broken structure of the circular rail frame 2. Next, the overlapping section of the outer protective layer 813 of the two insulation pipes 81 is cleaned to remove oil, dust and other impurities from the surface. Subsequently, the circular rail frame 2 is reset to the assembled state by adjusting the bidirectional screw 14.

[0040] During the welding process, firstly, the two cylindrical ends of the hot melt sleeve 82 (which is generally pre-processed into a cylindrical shape with lap joints in the circumferential direction) are fitted onto the lapped sections of the outer protective layers 813 of the two insulation pipes 81, and the arc-shaped ends of the hot melt sleeve 82 are usually kept in an lapped state; then, the two fastening straps 55 are wrapped around the hot melt sleeve 82, and the belt shaft 56 is snapped into the bayonet 521, and the screws 522 of the two fastening mechanisms 5 are rotated in sequence, causing the roller frame 52 to slide towards the center of the rotating ring 3, so that the transition roller 54 and the belt shaft 56 press the fastening straps 55 tightly onto the hot melt sleeve 82. Then, the take-up roller 53 is rotated to drive the fastening straps 55 to wind up, thereby securing the fastening straps 55... 5. Tighten the hot melt sleeve 82 so that the overlapping section of the hot melt sleeve 82 and the outer sheath of the two insulation pipes 81 is tightly wrapped; then, adjust the relative position of the two circular rail frames 2 so that the large radius circular roller sections of the two pressure rollers 421 of the pressure roller component 42 correspondingly avoid the two fastening bands 55. Then, through the adjustment of the drive component 41, the eight pressure roller components 42 move synchronously closer to the center of the rotating ring 3, and press the small radius circular roller sections of the two pressure rollers 421 of each pressure roller component 42 onto the fastening band 55. The eight pressure roller components 42 constitute an outer support section that is evenly distributed around the circumference of the hot melt sleeve 82, ensuring that the hot melt sleeve 82 is stably fitted and overlapped between the joints of the two insulation sleeves.

[0041] Next, the resistance wires built into the two overlapping ports on the hot melt welding machine 7 and the hot melt sleeve 82 are electrically connected to the specific components. Figure 9As shown, after power is applied, the resistance wire heats up, causing the overlapping position of the hot melt sleeve 82 and the outer protective layer 813 of the insulation pipe 81 to be heated and melted simultaneously, thus completing the hot melt welding. Afterwards, wait for the hot melt welded area to cool naturally. During the cooling process, the eight pressure rollers 42 can be driven by the rotating ring 3 to reciprocate around its center at a small angle, and the pressure can be adjusted to make the plastic material evenly extended and dispersed, and to expel any air bubbles that may exist in the material at the hot melt joint, thereby improving the tightness of the hot melt overlap.

[0042] After cooling is complete, the pressure roller 42 is moved away from the center of the rotating ring 3 by the drive assembly 41, the fastening belt 55 is loosened, the belt shaft 56 is removed from the buckle, and the screw 522 is rotated again to gradually move the roller frame 52 away from the heat-melt sleeve 82 to complete the repositioning operation; then, a layer of heat-shrinkable tape 83 is wound around the two heat-melt ports on the outside of the heat-melt sleeve 82, and a layer of heat-shrinkable tape 83 is covered at the overlap seam at the long end of the heat-melt sleeve 82; then, the relative positions of the two circular rail frames 2 are adjusted so that the stepped positions of the two pressure rollers 421 of the pressure roller 42 can be locked at the port positions of the heat-melt sleeve 82 to ensure that the heat-shrinkable tape 83 is tightly heat-shrinkable at the port stepped positions of the heat-melt sleeve 82; then, the drive assembly 41 is started again so that the two pressure rollers 421 of the pressure roller 42 are pressed onto the two heat-shrinkable tapes 83 respectively.

[0043] Next, the heat shrinkable tape 83 is heat-shrinked. First, the hot air blower 6 is turned on. Then, the rotating ring 3 drives the pressure rollers 42 and the hot air blower 6 to rotate synchronously. During rotation, the evenly distributed hot air blower 6 heats the heat shrinkable tape 83 evenly, preventing uneven heating. After being heated, the heat shrinkable tape 83 softens and shrinks, wrapping around the end of the heat-melt sleeve 82. The evenly distributed pressure rollers 42 simultaneously roll and press the heated heat shrinkable tape 83, increasing the wrapping force between the heat shrinkable tape 83 and the heat-melt sleeve 82, improving the sealing effect at the weld. This can replace manual labor in the automated heat shrinking and sealing operation of the heat shrinkable tape 83. In this invention, the other heat shrinkable tape 83 can be heated manually. This completes the overall heat fusion welding process before and after the insulation pipe 81. Figure 10 The diagram shown is a structural diagram of the two insulation pipes 81 after final welding.

[0044] This invention provides an electrofusion welding machine for insulated pipe joints, equipped with a welding auxiliary frame that works in conjunction with an existing electrofusion welding machine 7. This auxiliary frame is specifically designed for pre- and post-electrofusion welding of the outer sheath 813 of the insulated pipe 81. The circular rail frame 2 and rotating ring 3 within the welding auxiliary frame are designed with a discontinuous structure to facilitate the placement and removal of the insulated pipe 81. The circular rail frame 2 is equipped with a fastening mechanism 5 that allows for easy clamping at the two electrofusion ports of the electrofusion sleeve 82. An adjustable pressure roller mechanism 4 is installed between the rotating rings 3, providing uniformly distributed external clamping support to the outside of the electrofusion sleeve 82. Together with the fastening mechanism 5, this ensures the stability of the overlapping joint of the electrofusion sleeve 82 and allows for roller pressing of the electrofusion area. The tight and roller-pressed shaping facilitates operation. In the heating and sealing stage of the heat shrinkable tape 83, the rotating ring 3 drives the uniformly dispersed hot air blower 6 and the pressure roller 42 to automatically rotate around the heat shrinkable tape 83, ensuring the uniformity of circumferential heating and dispersion of the heat shrinkable tape 83, so as to facilitate uniform shrinkage. The roller pressing operation of the pressure roller 42 in sync improves the tightness of the fit between the shrinkable tape and the heat-melting sleeve 82. In summary, the welding auxiliary frame provided in this invention has a high degree of integration, meets various operations before and after the heat melting welding of the outer protective layer 813 of the insulation pipe 81, is convenient to operate, and can improve the standardization and normalization of the welding operation of the insulation pipe 81. While ensuring the quality of the welding formation, it improves the uniformity of quality and avoids rework.

[0045] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, 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 this invention.

[0046] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "connected," "installed," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0047] The preferred embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and the devices and structures not described in detail should be understood as being implemented in a manner common to the art; any possible variations and modifications made by those skilled in the art without departing from the technical solution of the present invention, or equivalent embodiments with equivalent changes, do not affect the essential content of the present invention. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the protection scope of the technical solution of the present invention.

Claims

1. An electrofusion welding machine for insulated pipe joints, comprising a hot melt welding machine and a welding auxiliary frame therewith, characterized in that, The welding auxiliary frame includes: Adjustable base; Two circular rail frames are horizontally coaxially arranged and installed opposite each other on the adjusting base; the circular rail frames are split in half along the vertical direction; the adjusting base can drive the two circular rail frames to synchronously separate and move and to move relative to each other along the axial direction. Two rotating rings are coaxially mounted on two circular rail frames, corresponding one to one; the rotating rings have a split structure. The pressure roller mechanism includes four drive components that are one-to-one assembled on four split structures of two rotating rings; multiple pressure rollers are horizontally rotatably mounted between the two drive components that are in relative positions on the two rotating rings, and all the pressure rollers are distributed along the circumference of the rotating rings; the distance between the multiple pressure rollers and the center of the rotating rings is adjusted synchronously under the joint drive of the two drive components; the pressure rollers have an axially contracting structure. Two fastening mechanisms are assembled one-to-one on two circular rail frames to fasten the two heat fusion joint ends of the insulation pipe accordingly. And two sets of hot air blowers, which are assembled one-to-one on two rotating rings; in each set, multiple hot air blowers are distributed and fixed on the rotating rings in a circumferential direction, and the air outlets of the hot air blowers are set towards the center of the rotating rings. The drive assembly includes an arc-shaped plate coaxially arranged and rotary driven on a rotating ring; multiple slide rails are fixedly distributed circumferentially on the split structure of the rotating ring, and sliding blocks are slidably installed on each slide rail, with a connecting rod hinged between each sliding block and the arc-shaped plate; a pressure roller is horizontally rotatably installed between two sliding blocks located in opposite positions axially on the rotating ring. The pressure roller assembly includes two horizontally symmetrically arranged pressure rollers that are rotatably mounted on two sliding blocks in a one-to-one correspondence. The two pressure rollers are elastically connected and slidably fitted with a splined shaft. The fastening mechanism includes a guide frame fixed to one of the split structures in the circular rail frame. The guide frame is equipped with a tightening frame that moves and adjusts towards the center of the rotating ring. The tightening frame is equipped with a fastening belt that provides tightening adjustment, and one end of the fastening belt is detachably mounted on the tightening frame. The tightening frame includes a roller frame that is slidably mounted on a guide frame, on which a take-up roller is horizontally rotatably mounted; one end of the fastening belt is fixed to the take-up roller, and the other end is fixed to a belt shaft; a bayonet is provided on the roller frame, and the belt shaft is snapped into the bayonet.

2. The electrofusion welding machine for insulated pipe joints according to claim 1, characterized in that: The adjusting base includes a base plate on which two guide rails are horizontally and relatively slidably mounted. Two circular rail frames are assembled one-to-one on the two guide rails, and two half-broken structures in the circular rail frames are slidably mounted on the guide rails in a direction perpendicular to the sliding direction of the guide rails. A double-headed telescopic rod is assembled between the two half-broken structures in the two circular rail frames at their axially opposite positions. The double-headed telescopic rod is fixed to the half-broken structures of the two circular rail frames through two telescopic ends.

3. The electrofusion welding machine for insulated pipe joints according to claim 1, characterized in that: The pressure roller has a stepped roller structure consisting of two roller segments with different diameters, and the roller segment with the larger diameter is arranged close to the sliding block.

4. The electrofusion welding machine for insulated pipe joints according to claim 1, characterized in that: The rotating ring is provided with a toothed ring.

5. The electrofusion welding machine for insulated pipe joints according to claim 1, characterized in that: The hot air blower is equipped with a flattened air outlet hood with a rectangular structure at the air outlet end, and the long side of the flattened air outlet hood is arranged along the rotation ring axis.

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