Polyethylene outer sheath melt extrusion winding and coating device and process

Abstract

The application relates to the field of anticorrosive coating technology and discloses a polyethylene outer protective layer melting extrusion winding and coating device and process, which comprises a pipeline positioning, advancing and rotating mechanism, a spiral winding mechanism is arranged on the side of the pipeline positioning, advancing and rotating mechanism, an arc-shaped rail and an arc-shaped toothed plate are arranged at the bottom of the spiral winding mechanism to dynamically adjust the extrusion inclination angle of a die head, a lifting mechanism is arranged on the discharge side, internal grinding blocks are used to clean the adhesive debris on the surface of the lifting roller and discharge the debris through the bottom opening, a compaction and pressure stabilizing mechanism and a cooling mechanism are sequentially arranged in the advancing direction of the pipe, the compaction and pressure stabilizing mechanism provides a flexible buffer thrust by combining a spring and a hydraulic rod, and a detection and regulation mechanism completes closed-loop linkage regulation and control of various operation parameters according to sensor feedback data. The application accurately matches winding pitches of different pipe diameters, dynamically and flexibly rolls and presses to completely discharge interlayer air, blocks the mixing of debris into the coating surface, promotes the dense fusion of the material belt, and improves the overall protection structure strength and surface flatness.

Description

Technical Field

[0001] This invention relates to the field of anti-corrosion coating technology, specifically to a polyethylene outer protective layer melt extrusion winding coating device and process. Background Technology

[0002] In industrial pipeline engineering, the polyethylene outer sheath is the core structure that ensures the insulation and corrosion protection of the pipeline. The industry uses the polyethylene melt extrusion winding process for production.

[0003] Existing spiral wound coating equipment has a relatively fixed extrusion die angle setting when dealing with pipes of different diameters. It can only be manually adjusted when the machine is stopped. During operation, the equipment cannot accurately match and adjust the winding angle according to the pipe diameter and travel speed. The extrusion speed, pipe travel speed and winding swing angle of the existing process are all controlled independently, lacking a linkage closed-loop feedback mechanism. The independent control of parameters causes the extruded material amount and winding pitch to not be accurately matched, resulting in uneven thickness and misalignment of the formed outer protective layer, which restricts the applicability of the equipment and the forming quality of the product.

[0004] In the process of wrapping and overlapping the strip, existing equipment mostly uses rigid limiting pressure rollers to physically crush the pipe surface. The rigid pressure rollers cannot flexibly buffer and dynamically adjust the pressure according to the changes in strip thickness and the undulations of the pipe surface. Due to the lack of a real-time pressure detection and feedback adjustment structure, simple mechanical compaction cannot completely squeeze out the air trapped between the layers. The residual air bubbles between the layers hinder the dense fusion of adjacent strips, resulting in delamination and bulging of the outer protective layer, which reduces the overall structural strength and sealing performance of the pipeline. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a polyethylene outer sheath melt extrusion winding coating device and process, which solves the problems of the equipment winding angle not being able to adaptively match the linkage, and the lack of flexible buffering in rigid physical rolling leading to residual air bubbles between layers and poor sheath density.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] The first aspect of this invention provides a polyethylene outer sheath melt extrusion winding device, comprising a pipeline positioning and traveling rotation mechanism, a spiral winding mechanism on one side of the pipeline positioning and traveling rotation mechanism, the spiral winding mechanism being used to melt and extrude polyethylene raw material into a strip shape, a lifting mechanism being provided on the discharge side of the spiral winding mechanism, the lifting mechanism being used to guide and lift the extruded strip, a compaction and stabilization mechanism and a cooling mechanism being sequentially provided on one side of the spiral winding mechanism along the pipeline traveling direction, the compaction and stabilization mechanism being used to compact and fuse the wound strip, the cooling mechanism being used to cool and shape the compacted outer sheath, and a detection and control mechanism being provided beside the spiral winding mechanism, the detection and control mechanism being used to collect production data and perform closed-loop linkage control of the spiral winding mechanism, the compaction and stabilization mechanism and the pipeline positioning and traveling rotation mechanism.

[0008] Preferably, the spiral winding mechanism includes a base, a temperature control cylinder is fixedly connected to the top of the base, a feed hopper is connected to the upper surface of the temperature control cylinder, a flat die head is fixedly connected to the discharge end of the temperature control cylinder, an extrusion cylinder is fixedly connected inside the temperature control cylinder, a first spiral rod and a second spiral rod are inserted and rotatably connected inside the extrusion cylinder, a first servo motor is fixedly connected to the end of the base, a driven gear is fixedly connected to the end of the first spiral rod, and the output end of the first servo motor is connected to the driven gear via a belt.

[0009] Preferably, a plurality of support columns are fixedly connected to the bottom of the base, and a universal ball is movably connected to the bottom end of the support columns. An arc-shaped rail is fixedly connected to the ground below the base, and the universal ball is slidably connected inside the arc-shaped rail. An arc-shaped toothed plate is fixedly connected to the outer side of the arc-shaped rail. A first stepper motor is fixedly connected to the lower surface of the base, and a first gear is fixedly connected to the output end of the first stepper motor. The first gear meshes with the arc-shaped toothed plate to adjust the winding angle.

[0010] Preferably, the compaction and stabilizing mechanism includes a column fixed to the side of the base, a rocker arm rotatably connected to the top of the column via a pin, a first bearing seat fixedly connected to the side wall of the column, a second bearing seat fixedly connected to the bottom surface of the rocker arm, a hydraulic rod rotatably connected between the first bearing seat and the second bearing seat, a sliding groove opened inside the cantilever end of the rocker arm, a slider slidably connected inside the sliding groove, a pressure roller rotatably connected to the side of the slider, and a spring fixedly connected between the slider and the top wall of the sliding groove.

[0011] Preferably, the cooling mechanism includes a gantry frame spanning above the pipe positioning and rotating mechanism. A first water collection seat is fixedly connected to the inner side of the gantry frame, and a second water collection seat is provided below the first water collection seat. A water inlet pipe is connected to the top of the first water collection seat, and multiple arrayed spray heads pointing towards the center are fixedly connected to the inner arc surfaces of both the first and second water collection seats.

[0012] Preferably, the pipe positioning and rotating mechanism includes a main track laid on the ground, a transverse toothed plate fixedly connected to one side of the inner wall of the main track, two mounting seats slidably connected above the main track, a second stepper motor fixedly connected to the bottom side of the mounting seat, a traveling gear meshing with the transverse toothed plate fixedly connected to the output end of the second stepper motor, a second servo motor fixedly connected to the top side of the mounting seat, and a hydraulic chuck for clamping the pipe fixedly connected to the output end of the second servo motor.

[0013] Preferably, the lifting mechanism includes a connecting plate fixedly connected to the discharge side of the spiral winding mechanism, a concave seat fixedly connected to the end of the connecting plate, an opening at the bottom of the concave seat, a first grinding block and a second grinding block fixedly connected to the inner side wall of the concave seat, a fixed seat provided between the first grinding block and the second grinding block, a plurality of lifting rollers rotatably connected to the front end of the concave seat, the opening communicating with the fixed seat, and forming a debris falling cavity between the first grinding block and the second grinding block.

[0014] Preferably, the detection and control mechanism includes an independently configured controller, a laser thickness and trajectory sensor, and a pressure sensor. The laser thickness and trajectory sensor and the pressure sensor are both electrically connected to the controller. The pressure sensor is installed on the inner top wall of the slide and connected to the top of the spring. The laser thickness and trajectory sensor is installed on the upper surface of the connecting plate on the discharge side of the flat die head.

[0015] Preferably, the controller is electrically connected to the drive ends of the spiral winding mechanism, the compaction and stabilization mechanism, and the pipe positioning and traveling rotation mechanism, respectively. The controller is used to synchronously regulate the running speed and swing angle of the spiral winding mechanism and the pipe positioning and traveling rotation mechanism, as well as regulate the thrust of the compaction and stabilization mechanism, based on the feedback signals from the laser thickness and trajectory sensor and the pressure sensor.

[0016] A second aspect of the present invention also provides a process for melt extrusion winding coating of a polyethylene outer sheath, the production process comprising the following steps:

[0017] S1. Remove rust and dust from the surface of the pipe substrate and preheat it to 40 to 80°C. Then, apply a special adhesive evenly to the surface of the pipe and keep the adhesive slightly tacky for later use.

[0018] S2. The polyethylene raw material is fed into the temperature control cylinder from the feed hopper. The first servo motor drives the first screw and the second screw to rotate, and the raw material is melted in multiple stages with temperature control, so that the set temperature control range is locked between 160 and 220°C. Finally, the continuous and uniform molten material strip is extruded by the flat die head.

[0019] S3. The two ends of the pre-treated pipe are clamped between the two hydraulic chucks. The controller starts the second servo motor and the second stepper motor to drive the pipe to rotate at a constant speed and move axially. At the same time, the first stepper motor drives the first gear to roll along the arc-shaped toothed plate, adaptively adjusting the winding angle of the base and the flat die head. The molten material strip is continuously wrapped on the surface of the pipe after being guided by the lifting roller.

[0020] S4. After the coated pipeline travels to the compaction and stabilization mechanism, the controller adjusts the output force of the hydraulic rod in real time according to the thickness of the material strip, drives the rocker arm to press down, and makes the pressure roller compact the molten material strip through the spring, squeezing out interlayer bubbles to achieve interlayer fusion;

[0021] S5. During the forming process, the laser thickness and trajectory sensor and the pressure sensor collect data in real time and feed it back to the controller, which synchronously controls the speed of the first servo motor, the swing angle of the first stepper motor, the thrust of the hydraulic rod, and the speed of the second servo motor and the second stepper motor.

[0022] S6. After compaction, the pipe passes through the gantry of the cooling mechanism. The spray head sprays water mist onto the surface of the pipe for surrounding cooling, controls the curing rate of the inner and outer layers to be consistent, eliminates the internal stress of molding, and avoids deformation and cracking.

[0023] S7. After cooling and shaping, the outer protective layer is formed into a sturdy and flat protective body. After cutting and end face treatment, it is inspected and put into storage.

[0024] This invention provides a polyethylene outer sheath melt extrusion winding coating device and process. It has the following beneficial effects:

[0025] 1. This invention sets an arc-shaped rail and an arc-shaped toothed plate under the base, and uses a first stepper motor to drive the first gear to roll in order to adjust the extrusion winding angle of the flat die head. Combined with the real-time feedback of the laser thickness and trajectory sensor in the detection and control mechanism, the controller synchronously adjusts the pipe travel speed and the die head swing angle, so that the device can accurately match the corresponding winding pitch when dealing with different pipe diameters, ensuring that the molten material strip is evenly covered on the pipe surface, and improving the consistency of production applicability and molding quality.

[0026] 2. This invention uses a compaction and stabilization mechanism consisting of a hydraulic rod, rocker arm, spring, and pressure roller. A pressure sensor is installed on the top wall of the chute. During the molding process, the pressure sensor collects the spring pressure in real time and feeds it back to the controller. The thrust of the hydraulic rod is dynamically adjusted so that the spring, in conjunction with closed-loop control, provides a stable and flexible buffer for the pressure roller. This ensures that the pressure roller is always in close contact with the molten material strip for uniform pressure rolling, thoroughly squeezing out residual air bubbles between layers, promoting the dense fusion of adjacent material strips, and improving the overall structural strength of the outer protective layer.

[0027] 3. This invention adds a lifting mechanism to the discharge side of the spiral winding mechanism. Multiple lifting rollers at the front end of the concave seat guide and stabilize the extruded molten strip. To prevent the high-temperature strip from adhering and affecting the roller surface, a first grinding block and a second grinding block are set inside the concave seat to clean the strip debris adhering to the lifting roller in real time. The cleaned debris falls directly into the debris drop cavity formed between the two grinding blocks and is discharged through the bottom opening, avoiding impurities from mixing into the coating surface and ensuring the flatness and winding quality of the final protective layer. Attached Figure Description

[0028] Figure 1 This is a perspective view of the present invention;

[0029] Figure 2 This is a schematic diagram of the main track structure of the present invention;

[0030] Figure 3 for Figure 2 Enlarged view of point A in the middle;

[0031] Figure 4 This is a schematic diagram of the structure of the base of the present invention;

[0032] Figure 5 This is a schematic diagram of the structure of the first gear of the present invention;

[0033] Figure 6 This is a schematic diagram of the driven gear of the present invention;

[0034] Figure 7 This is a schematic diagram of the structure of the first screw rod of the present invention;

[0035] Figure 8 This is a schematic diagram of the rocker arm of the present invention;

[0036] Figure 9 This is a schematic diagram of the concave seat of the present invention.

[0037] Among them, 1. Spiral winding mechanism; 11. Base; 12. Temperature control cylinder; 13. Feed hopper; 14. Flat die head; 15. Arc-shaped rail; 16. First gear; 17. First stepper motor; 18. Universal ball; 19. Support column; 110. First servo motor; 111. Extrusion cylinder; 112. Belt; 113. Driven gear; 114. First spiral rod; 115. Second spiral rod; 116. Arc-shaped toothed plate; 2. Compaction and pressure stabilizing mechanism; 21. Column; 22. Pin; 23. First bearing seat; 24. Hydraulic rod; 25. Second bearing seat; 26. Rocker arm; 27. Slide groove; 28. Spring; 29. ​​Pressure roller; 210. 1. Slider; 3. Cooling mechanism; 31. Gantry frame; 32. Water inlet pipe; 33. First water collection seat; 34. Second water collection seat; 35. Spray head; 4. Pipe positioning and traveling rotation mechanism; 41. Main track; 42. Transverse toothed plate; 43. Mounting seat; 44. Second servo motor; 45. Hydraulic chuck; 46. Second stepper motor; 47. Travel gear; 5. Detection and control mechanism; 51. Controller; 52. Laser thickness and trajectory sensor; 53. Pressure sensor; 6. Lifting mechanism; 61. Connecting plate; 62. Concave seat; 63. Opening; 64. First grinding block; 65. Fixed seat; 66. Second grinding block; 67. Lifting roller. Detailed Implementation

[0038] The technical solutions in 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.

[0039] Please see the appendix Figure 1 To be continued Figure 9 This invention provides a polyethylene outer sheath melt extrusion winding device, including a pipeline positioning and traveling rotation mechanism 4. A spiral winding mechanism 1 is provided on one side of the pipeline positioning and traveling rotation mechanism 4. The spiral winding mechanism 1 is used to melt and extrude polyethylene raw materials into a strip shape. A lifting mechanism 6 is provided on the discharge side of the spiral winding mechanism 1. The lifting mechanism 6 is used to guide and lift the extruded strip. A compaction and stabilization mechanism 2 and a cooling mechanism 3 are sequentially provided on one side of the spiral winding mechanism 1 along the pipeline traveling direction. The compaction and stabilization mechanism 2 is used to compact and fuse the wound strip. The cooling mechanism 3 is used to cool and shape the compacted outer sheath. A detection and control mechanism 5 is provided on the side of the spiral winding mechanism 1. The detection and control mechanism 5 is used to collect production data and perform closed-loop linkage control of the spiral winding mechanism 1, the compaction and stabilization mechanism 2, and the pipeline positioning and traveling rotation mechanism 4.

[0040] Specifically, during the operation of the device, the two ends of the pre-treated pipe are first clamped. The pipe positioning and rotating mechanism 4 drives the pipe to rotate at a constant speed and move at a constant speed along the axial direction. At the same time, the spiral winding mechanism 1 performs multi-stage temperature-controlled shearing and plasticizing on the polyethylene raw material and extrudes a continuous and uniform molten strip. The extrusion winding angle is adaptively and precisely adjusted by the detection and control mechanism 5. Before the extruded molten strip covers the pipe surface, it is guided and stabilized by the lifting mechanism 6, and edge debris is removed. Then, the compaction and stabilization mechanism 2 performs dynamic compaction and rolling to completely expel interlayer air bubbles to achieve dense fusion. During this forming process, the detection and control mechanism 5 collects data in real time and provides feedback, and performs closed-loop pressure stabilization and control throughout the process. Finally, the cooling mechanism 3 sprays water mist around the pipe surface in a 360-degree circle to evenly cool it and quickly shape it into a solid and flat protective body.

[0041] Please see the appendix Figure 4 Appendix Figure 5 Appendix Figure 6 and attached Figure 7 In a preferred embodiment of the present invention, the spiral winding mechanism 1 includes a base 11, a temperature control cylinder 12 fixedly connected to the top of the base 11, a feed hopper 13 communicating with the upper surface of the temperature control cylinder 12, a flat die head 14 fixedly connected to the discharge end of the temperature control cylinder 12, an extrusion cylinder 111 fixedly connected inside the temperature control cylinder 12, a first spiral rod 114 and a second spiral rod 115 interlocking and rotatably connected inside the extrusion cylinder 111, a first servo motor 110 fixedly connected to the end of the base 11, and a driven gear 113 fixedly connected to the end of the first spiral rod 114. The output end of the machine 110 is connected to the driven gear 113 via a belt 112. Several support columns 19 are fixedly connected to the bottom of the base 11. Universal ball joints 18 are movably connected to the bottom of the support columns 19. An arc-shaped rail 15 is fixedly connected to the ground below the base 11. The universal ball joints 18 are slidably connected inside the arc-shaped rail 15. An arc-shaped toothed plate 116 is fixedly connected to the outer side of the arc-shaped rail 15. A first stepper motor 17 is fixedly connected to the lower surface of the base 11. A first gear 16 is fixedly connected to the output end of the first stepper motor 17. The first gear 16 meshes with the arc-shaped toothed plate 116 to adjust the winding angle.

[0042] Specifically, polyethylene raw material is fed into the temperature control cylinder 12 from the feed hopper 13. The first servo motor 110 drives the first screw rod 114 and the second screw rod 115 to rotate at high speed through the belt 112, which performs multi-stage temperature-controlled shearing and plasticization on the raw material. Finally, the flat die head 14 extrudes a continuous and uniform molten strip. In order to match the winding pitch of different pipe diameters, the first step motor 17 drives the first gear 16 to roll along the arc-shaped tooth plate 116, which drives the universal ball 18 at the bottom of the base 11 to slide in the arc-shaped rail 15, thereby adaptively and precisely adjusting the extrusion winding angle of the flat die head 14.

[0043] Please see the appendix Figure 8 In a preferred embodiment of the present invention, the compaction and stabilization mechanism 2 includes a column 21 fixed to the side of the base 11. The top of the column 21 is rotatably connected to a rocker arm 26 via a pin 22. A first bearing seat 23 is fixedly connected to the side wall of the column 21. A second bearing seat 25 is fixedly connected to the bottom surface of the rocker arm 26. A hydraulic rod 24 is rotatably connected between the first bearing seat 23 and the second bearing seat 25. A sliding groove 27 is provided inside the cantilever end of the rocker arm 26. A slider 210 is slidably connected inside the sliding groove 27. A pressure roller 29 is rotatably connected to the side of the slider 210. A spring 28 is fixedly connected between the slider 210 and the inner top wall of the sliding groove 27.

[0044] Specifically, as the pipe rotates and moves forward, the pipe section wrapped with molten material enters the compaction and stabilization mechanism 2. The hydraulic rod 24 extends and moves the rocker arm 26 downward around the pin shaft 22, causing the slider 210 in the chute 27 to move downward. Under the flexible buffer and stabilization effect of the spring 28, the pressure roller 29 closely adheres to and rolls the newly wrapped molten material, completely squeezing out interlayer bubbles and achieving dense fusion.

[0045] Please see the appendix Figure 1 In a preferred embodiment of the present invention, the cooling mechanism 3 includes a gantry frame 31 spanning above the pipe positioning and traveling rotation mechanism 4. A first water collection seat 33 is fixedly connected to the inner side of the gantry frame 31. A second water collection seat 34 is provided below the first water collection seat 33. A water inlet pipe 32 is connected to the top of the first water collection seat 33. Multiple arrayed spray heads 35 pointing towards the center are fixedly connected to the inner arc surfaces of the first water collection seat 33 and the second water collection seat 34.

[0046] Specifically, after compaction, the pipe passes through the gantry 31 of the cooling mechanism 3. The spray nozzles 35 inside the first water collection seat 33 and the second water collection seat 34 spray water mist around the pipe surface in a 360-degree circle, which evenly cools the high-temperature outer protective layer, eliminates internal stress, and quickly shapes it into a solid and flat protective body.

[0047] Please see the appendix Figure 2 and attached Figure 3 In a preferred embodiment of the present invention, the pipe positioning and traveling rotation mechanism 4 includes a main track 41 laid on the ground, a transverse toothed plate 42 fixedly connected to one side of the inner wall of the main track 41, two mounting seats 43 slidably connected above the main track 41, a second stepper motor 46 fixedly connected to the bottom side of the mounting seat 43, a traveling gear 47 meshing with the transverse toothed plate 42 fixedly connected to the output end of the second stepper motor 46, a second servo motor 44 fixedly connected to the top side of the mounting seat 43, and a hydraulic chuck 45 for clamping the pipe fixedly connected to the output end of the second servo motor 44.

[0048] Specifically, during operation, the two ends of the pre-treated pipe are clamped between the hydraulic chucks 45 on the two mounting bases 43. The controller 51 starts the second servo motor 44 to drive the hydraulic chucks 45 to rotate the pipe at a constant speed. At the same time, the second stepper motor 46 drives the traveling gear 47 to roll on the transverse toothed plate 42 of the main track 41, driving the pipe to move at a constant speed along the axial direction.

[0049] Please see the appendix Figure 9 In a preferred embodiment of the present invention, the lifting mechanism 6 includes a connecting plate 61 fixedly connected to the discharge side of the spiral winding mechanism 1. A concave seat 62 is fixedly connected to the end of the connecting plate 61. An opening 63 is provided at the bottom of the concave seat 62. A first grinding block 64 and a second grinding block 66 are fixedly connected to the inner side wall of the concave seat 62. A fixed seat 65 is provided between the first grinding block 64 and the second grinding block 66. A plurality of lifting rollers 67 are rotatably connected to the front end of the concave seat 62. The opening 63 communicates with the fixed seat 65 and forms a debris falling cavity between the first grinding block 64 and the second grinding block 66.

[0050] Specifically, before the extruded molten material strip is coated onto the pipe surface, it is first guided and stabilized by the lifting roller 67. The lifting roller can rotate due to friction. By utilizing the rotation of the lifting roller 67, the first grinding block 64 and the second grinding block 66 can clean the debris remaining on the surface of the lifting roller 67. The debris generated at the edge of the material strip is directly discharged from the debris falling cavity formed between the first grinding block 64 and the second grinding block 66 through the opening 63.

[0051] Please see the appendix Figure 1 Appendix Figure 8 and attached Figure 9 In a preferred embodiment of the present invention, the detection and control mechanism 5 includes an independently configured controller 51, a laser thickness and trajectory sensor 52, and a pressure sensor 53. The laser thickness and trajectory sensor 52 and the pressure sensor 53 are both electrically connected to the controller 51. The pressure sensor 53 is installed on the inner top wall of the slide 27 and connected to the top of the spring 28. The laser thickness and trajectory sensor 52 is installed on the upper surface of the connecting plate 61 located on the discharge side of the flat die head 14. The controller 51 is electrically connected to the drive ends of the spiral winding mechanism 1, the compaction and stabilization mechanism 2, and the pipe positioning and traveling rotation mechanism 4, respectively. The controller 51 is used to synchronously control the running speed and swing angle of the spiral winding mechanism 1 and the pipe positioning and traveling rotation mechanism 4, and to control the thrust of the compaction and stabilization mechanism 2, based on the feedback signals of the laser thickness and trajectory sensor 52 and the pressure sensor 53.

[0052] Specifically, during the molding process, the laser thickness and trajectory sensor 52 installed on the connecting plate 61 and the pressure sensor 53 on the top wall of the chute 27 collect the thickness of the material strip and the pressure of the spring 28 in real time, and feed the data back to the controller 51. The controller 51 then synchronously controls the running speed, swing angle and thrust of each motor and the hydraulic rod 24 to achieve closed-loop pressure regulation throughout the process.

[0053] This invention also provides a process for melt extrusion winding coating of polyethylene outer sheath, the production process including the following steps:

[0054] S1. Remove rust and dust from the surface of the pipe substrate and preheat it to 40 to 80°C. Then, apply a special adhesive evenly to the surface of the pipe and keep the adhesive slightly tacky for later use.

[0055] S2. The polyethylene raw material is fed into the temperature control cylinder 12 from the feed hopper 13. The first servo motor 110 drives the first screw rod 114 and the second screw rod 115 to rotate, and the raw material is subjected to multi-stage temperature control melting, so that the set temperature control range is locked between 160 and 220°C. Finally, the continuous and uniform molten material strip is extruded by the flat die head 14.

[0056] S3. The two ends of the pre-treated pipe are clamped between two hydraulic chucks 45. The controller 51 starts the second servo motor 44 and the second stepper motor 46 to drive the pipe to rotate at a constant speed and move axially. At the same time, the first stepper motor 17 drives the first gear 16 to roll along the arc-shaped toothed plate 116, adaptively adjusting the winding angle of the base 11 and the flat die head 14. The molten material strip is continuously wrapped on the surface of the pipe after being guided by the lifting roller 67.

[0057] S4. After the coating, the pipeline travels to the compaction and stabilization mechanism 2. The controller 51 adjusts the output force of the hydraulic rod 24 in real time according to the thickness of the material strip, which drives the rocker arm 26 to press down, so that the pressure roller 29 compacts the molten material strip through the spring 28, and squeezes out the interlayer bubbles to achieve interlayer fusion.

[0058] S5. During the forming process, the laser thickness and trajectory sensor 52 and the pressure sensor 53 collect data in real time and feed it back to the controller 51. The controller 51 synchronously controls the speed of the first servo motor 110, the swing angle of the first stepper motor 17, the thrust of the hydraulic rod 24, and the speed of the second servo motor 44 and the second stepper motor 46.

[0059] S6. After compaction, the pipe passes through the gantry 31 of the cooling mechanism 3. The spray head 35 sprays water mist onto the surface of the pipe for surrounding cooling, controls the curing rate of the inner and outer layers to be consistent, eliminates the internal stress of molding, and avoids deformation and cracking.

[0060] S7. After cooling and shaping, the outer protective layer is formed into a sturdy and flat protective body. After cutting and end face treatment, it is inspected and put into storage.

[0061] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A polyethylene outer sheath melt extrusion winding coating device, comprising a pipe positioning and traveling rotation mechanism (4), characterized in that, A spiral winding mechanism (1) is provided on one side of the pipeline positioning and traveling rotation mechanism (4). The spiral winding mechanism (1) is used to melt and extrude polyethylene raw material into a strip. A lifting mechanism (6) is provided on the discharge side of the spiral winding mechanism (1). The lifting mechanism (6) is used to guide and lift the extruded strip. A compaction and stabilization mechanism (2) and a cooling mechanism (3) are arranged sequentially on one side of the spiral winding mechanism (1) along the pipeline traveling direction. The compaction and stabilization mechanism (2) is used to compact and fuse the wound strip. The cooling mechanism (3) is used to cool and shape the compacted outer protective layer. A detection and control mechanism (5) is provided on the side of the spiral winding mechanism (1). The detection and control mechanism (5) is used to collect production data and perform closed-loop linkage control of the spiral winding mechanism (1), the compaction and stabilization mechanism (2), and the pipeline positioning and traveling rotation mechanism (4).

2. The polyethylene outer sheath melt extrusion winding coating device according to claim 1, characterized in that, The spiral winding mechanism (1) includes a base (11), a temperature control cylinder (12) is fixedly connected to the top of the base (11), a feed hopper (13) is connected to the upper surface of the temperature control cylinder (12), a flat die head (14) is fixedly connected to the discharge end of the temperature control cylinder (12), an extrusion cylinder (111) is fixedly connected inside the temperature control cylinder (12), a first spiral rod (114) and a second spiral rod (115) are inserted and rotated inside the extrusion cylinder (111), a first servo motor (110) is fixedly connected to the end of the base (11), a driven gear (113) is fixedly connected to the end of the first spiral rod (114), and the output end of the first servo motor (110) is connected to the driven gear (113) through a belt (112).

3. The polyethylene outer sheath melt extrusion winding coating device according to claim 2, characterized in that, The base (11) is fixedly connected to a number of support columns (19) at its bottom. The bottom end of the support column (19) is movably connected to a universal ball (18). An arc-shaped rail (15) is fixedly connected to the ground below the base (11). The universal ball (18) is slidably connected to the arc-shaped rail (15). An arc-shaped toothed plate (116) is fixedly connected to the outer side of the arc-shaped rail (15). A first stepper motor (17) is fixedly connected to the lower surface of the base (11). A first gear (16) is fixedly connected to the output end of the first stepper motor (17). The first gear (16) meshes with the arc-shaped toothed plate (116) to adjust the winding angle.

4. The polyethylene outer sheath melt extrusion winding coating device according to claim 1, characterized in that, The compaction and stabilizing mechanism (2) includes a column (21) fixed to the side of the base (11). The top of the column (21) is rotatably connected to a rocker arm (26) via a pin (22). A first bearing seat (23) is fixedly connected to the side wall of the column (21). A second bearing seat (25) is fixedly connected to the bottom surface of the rocker arm (26). A hydraulic rod (24) is rotatably connected between the first bearing seat (23) and the second bearing seat (25). A sliding groove (27) is provided inside the cantilever end of the rocker arm (26). A slider (210) is slidably connected inside the sliding groove (27). A pressure roller (29) is rotatably connected to the side of the slider (210). A spring (28) is fixedly connected between the slider (210) and the inner top wall of the sliding groove (27).

5. The polyethylene outer sheath melt extrusion winding coating device according to claim 1, characterized in that, The cooling mechanism (3) includes a gantry frame (31) spanning above the pipe positioning and traveling rotation mechanism (4). A first water collection seat (33) is fixedly connected to the inner side of the gantry frame (31). A second water collection seat (34) is provided below the first water collection seat (33). A water inlet pipe (32) is connected to the top of the first water collection seat (33). Multiple arrayed spray heads (35) pointing towards the center are fixedly connected to the inner arc surfaces of the first water collection seat (33) and the second water collection seat (34).

6. The polyethylene outer sheath melt extrusion winding coating device according to claim 1, characterized in that, The pipe positioning and rotating mechanism (4) includes a main track (41) laid on the ground. A transverse toothed plate (42) is fixedly connected to one side of the inner wall of the main track (41). Two mounting seats (43) are slidably connected above the main track (41). A second stepper motor (46) is fixedly connected to the bottom side of the mounting seat (43). A traveling gear (47) that meshes with the transverse toothed plate (42) is fixedly connected to the output end of the second stepper motor (46). A second servo motor (44) is fixedly connected to the top side of the mounting seat (43). A hydraulic chuck (45) for clamping the pipe is fixedly connected to the output end of the second servo motor (44).

7. The polyethylene outer sheath melt extrusion winding coating device according to claim 1, characterized in that, The lifting mechanism (6) includes a connecting plate (61) fixedly connected to the discharge side of the spiral winding mechanism (1). A concave seat (62) is fixedly connected to the end of the connecting plate (61). An opening (63) is provided at the bottom of the concave seat (62). A first grinding block (64) and a second grinding block (66) are fixedly connected to the inner side wall of the concave seat (62). A fixed seat (65) is provided between the first grinding block (64) and the second grinding block (66). A plurality of lifting rollers (67) are rotatably connected to the front end of the concave seat (62). The opening (63) communicates with the fixed seat (65) and forms a debris falling cavity between the first grinding block (64) and the second grinding block (66).

8. The polyethylene outer sheath melt extrusion winding coating device according to claim 1, characterized in that, The detection and control mechanism (5) includes an independently set controller (51), a laser thickness and trajectory sensor (52), and a pressure sensor (53). The laser thickness and trajectory sensor (52) and the pressure sensor (53) are both electrically connected to the controller (51). The pressure sensor (53) is installed on the inner top wall of the slide (27) and connected to the top of the spring (28). The laser thickness and trajectory sensor (52) is installed on the upper surface of the connecting plate (61) on the discharge side of the flat die head (14).

9. The polyethylene outer sheath melt extrusion winding coating device according to claim 8, characterized in that, The controller (51) is electrically connected to the drive ends of the spiral winding mechanism (1), the compaction and stabilization mechanism (2) and the pipeline positioning and traveling rotation mechanism (4), respectively. The controller (51) is used to synchronously control the running speed and swing angle of the spiral winding mechanism (1) and the pipeline positioning and traveling rotation mechanism (4) and control the thrust of the compaction and stabilization mechanism (2) according to the feedback signals of the laser thickness and trajectory sensor (52) and the pressure sensor (53).

10. A polyethylene outer sheath melt extrusion winding coating process, characterized in that, Using the polyethylene outer sheath melt extrusion winding coating apparatus according to any one of claims 1-9, the production process includes the following steps: S1. Remove rust and dust from the surface of the pipe substrate and preheat it to 40 to 80°C. Then, apply a special adhesive evenly to the surface of the pipe and keep the adhesive slightly tacky for later use. S2. The polyethylene raw material is fed into the temperature control cylinder (12) from the feed hopper (13). The first servo motor (110) drives the first screw rod (114) and the second screw rod (115) to rotate, and the raw material is subjected to multi-stage temperature control melting, so that the set temperature control range is locked at 160 to 220°C. Finally, the flat die head (14) extrudes a continuous and uniform molten strip. S3. The two ends of the pre-treated pipe are clamped between the two hydraulic chucks (45). The controller (51) starts the second servo motor (44) and the second stepper motor (46) to drive the pipe to rotate at a constant speed and move axially. At the same time, the first stepper motor (17) drives the first gear (16) to roll along the arc-shaped toothed plate (116) to adaptively adjust the winding angle of the base (11) and the flat die head (14). The molten material strip is continuously wrapped around the surface of the pipe after being guided by the lifting roller (67). S4. After the coated pipeline travels to the compaction and stabilization mechanism (2), the controller (51) adjusts the output force of the hydraulic rod (24) in real time according to the thickness of the material strip, drives the rocker arm (26) to press down, so that the pressure roller (29) compacts the molten material strip through the spring (28), and squeezes out interlayer bubbles to achieve interlayer fusion. S5. During the molding process, the laser thickness and trajectory sensor (52) and the pressure sensor (53) collect data in real time and feed it back to the controller (51). The controller (51) synchronously controls the rotation speed of the first servo motor (110), the swing angle of the first stepper motor (17), the thrust of the hydraulic rod (24), and the speed of the second servo motor (44) and the second stepper motor (46). S6. After compaction, the pipe passes through the gantry (31) of the cooling mechanism (3). The spray head (35) sprays water mist onto the surface of the pipe for surrounding cooling, controls the curing rate of the inner and outer layers to be consistent, eliminates the internal stress of molding, and avoids deformation and cracking. S7. After cooling and shaping, the outer protective layer is formed into a sturdy and flat protective body. After cutting and end face treatment, it is inspected and put into storage.

Images