Large-diameter pipe multilayer co-extrusion production line

Abstract

The present application relates to the technical field of pipe processing, in particular to a large-diameter pipe multi-layer co-extrusion production line, which comprises a feeding hopper, an extrusion unit is communicated below the feeding hopper, one end of the extrusion unit is sequentially provided with a multi-layer co-extrusion die head and a pipe cooling and shaping device, and one end of the pipe cooling and shaping device is provided with a fixing frame; when the telescopic rod is elongated, negative pressure is generated in the annular groove, the feeding hole of the elastic dust extraction cover and the communication pipe are matched, and the cutting debris is sucked into the recovery pipe in real time; when the telescopic rod is reset, positive pressure is generated, the debris is pushed to the feeding hopper through the feeding pipe, mixed with new raw materials and processed again, the problems of debris scattering and polluting the workshop and manual recovery in traditional cutting are solved, the closed-loop process of cutting, recovery and recycling is realized, the utilization rate of raw materials is improved, and the labor cost is reduced.

Description

Technical Field

[0001] This invention relates to the field of pipe processing technology, specifically to a multi-layer co-extrusion production line for large-diameter pipes. Background Technology

[0002] In modern industry, large-diameter pipes are widely used in water supply and drainage, gas transmission, chemical industry and other industries due to their advantages such as good fluid transportation performance and high structural strength. The multi-layer co-extrusion production line of large-diameter pipes can give the pipes better comprehensive performance by extruding and compounding plastic raw materials to meet the needs of complex working conditions.

[0003] In the production of large-diameter pipes, cutting the finished pipes to a fixed length is an essential step. However, existing cutting methods typically generate a large amount of debris, which falls directly onto the production workshop floor. This not only pollutes the production environment and affects the cleanliness and hygiene of the workshop, but may also mix into other production equipment, causing equipment malfunctions and affecting the continuity and stability of production. In addition, the existing debris handling process is cumbersome. After collecting the debris, a dedicated person needs to collect it separately and then put it back into the feed funnel for secondary processing. This method not only increases labor and time costs, but also easily causes debris loss during collection, transportation, and re-feeding, reducing the utilization rate of raw materials. Therefore, a multi-layer co-extrusion production line for large-diameter pipes is proposed to achieve a closed-loop process of immediate collection of cutting debris and direct transportation to the feed end, thereby improving processing efficiency and reducing production costs. Summary of the Invention

[0004] To address the problems in the existing technology, this invention provides a multi-layer co-extrusion production line for large-diameter pipes, which realizes closed-loop processing of cutting debris for immediate recycling and direct conveying to the feeding end, thereby improving processing efficiency and reducing production costs.

[0005] The technical solution adopted by this invention to solve its technical problem is a multi-layer co-extrusion production line for large-diameter pipes, including a feeding funnel. An extrusion unit is connected to the bottom of the feeding funnel. One end of the extrusion unit is sequentially provided with a multi-layer co-extrusion die and a pipe cooling and shaping device. One end of the pipe cooling and shaping device is provided with a fixed frame. The fixed frame is fixedly connected to the pipe cooling and shaping device through a telescopic rod. A circular through groove is provided in the middle of the fixed frame. An annular groove is provided on the inner side of the circular through groove. A rotating ring is rotatably connected in a sealed manner in the annular groove. A pipe ring cutting machine is provided on the inner side of the rotating ring. Elastic dust extraction hoods communicating with the inside of the annular groove are provided on both sides of the pipe ring cutting machine. A recovery pipe communicating with the annular groove is provided on one side of the fixed frame. The fixed end of the telescopic rod is connected to the inside of the annular groove through the recovery pipe. The recovery pipe is connected to the top of the feeding funnel through a feeding pipe.

[0006] Specifically, an electric telescopic cylinder is fixedly connected to the inner side of the rotating ring. The pipe ring cutting machine is fixedly connected to the output end of the electric telescopic cylinder through a support plate. The output end of the electric telescopic cylinder is connected to an elastic dust extraction hood through an elastic hinge shaft. The side of the elastic dust extraction hood near the pipe ring cutting blade is provided with several sets of feed holes. The side of the elastic dust extraction hood away from the feed holes is connected to a connecting pipe. One end of the connecting pipe passes through the rotating ring and communicates with the inside of the annular groove.

[0007] A drive motor is installed on the outside of the fixed frame. The output end of the drive motor passes through the fixed frame and is fixedly connected to a friction wheel. The friction wheel drives the rotation by friction with one side of the rotating ring.

[0008] Specifically, elastic pads are fixedly connected to both sides of the elastic dust extraction cover.

[0009] Specifically, the telescopic rod includes a fixed cylinder, one end of which is fixedly connected to the pipe cooling and shaping device. A sealing plate is slidably connected to the inside of the fixed cylinder. A horizontally arranged transmission screw is rotatably connected to the side of the sealing plate away from the pipe cooling and shaping device. One end of the transmission screw passes through the fixed cylinder and is threadedly connected to the fixed cylinder. A transmission pulley is fixedly connected to the end of the transmission screw away from the sealing plate. Adjacent transmission pulleys are driven by a transmission belt. A drive motor is fixedly connected to one end of the fixed frame. The output end of the drive motor is fixedly connected to a set of corresponding transmission screws. One end of another set of transmission screws is fixedly connected to one side of the fixed frame through a rotating seat.

[0010] Specifically, the fixed end of the fixed cylinder is connected to the inside of the recovery pipe through a negative pressure pipe. The inside of the recovery pipe is equipped with a filter screen plate corresponding to the negative pressure pipe. One side of the fixed frame is equipped with a first one-way valve connected to the annular groove. The first one-way valve is connected to one end of the recovery pipe through a hose.

[0011] Specifically, the end of the recovery pipe furthest from the hose is connected to a second check valve, which is connected to one end of the feeding pipe. The other end of the feeding pipe is connected to the top of the feeding funnel, and a pump connected to the feeding pipe is located above the feeding funnel.

[0012] Specifically, the pipe circumferential cutting machine includes a bracket connected to a support plate, a rotating shaft rotatably connected to the bracket, a cutting blade and a power motor coaxially connected to the rotating shaft, the power motor being fixedly connected to the bracket, mounting grooves on both sides of the cutting blade, a grinding plate being provided in the mounting groove, a compression spring being fixedly connected between the grinding plate and the mounting groove, and a wedge-shaped compression surface being provided on the edge of the grinding plate away from the axis of the cutting blade.

[0013] Specifically, the inner side of the annular groove is provided with an annular guide groove, and the inner side of the rotating ring is provided with an annular guide slider that is slidably connected to the annular guide groove.

[0014] Specifically, an arc-shaped guide plate is provided at one end of the fixed frame near the pipe cooling and shaping device. Several sets of rollers are provided on the inner side of the arc-shaped guide plate. One side of the arc-shaped guide plate is fixedly connected to one side of the fixed frame through a connecting rod. Circularly distributed elastic plates are provided on the inner side of the circular through groove.

[0015] The beneficial effects of this invention are:

[0016] The present invention discloses a multi-layer co-extrusion production line for large-diameter pipes. When the telescopic rod extends, it generates negative pressure in the annular groove. Combined with the feed hole and connecting pipe of the elastic dust extraction hood, the cutting debris is sucked into the recycling pipe in real time. When the telescopic rod returns to its original position, it generates positive pressure, which pushes the debris to the feed funnel through the feeding pipe. The debris is then mixed with new raw materials for reprocessing. This solves the problems of debris scattering and polluting the workshop and requiring manual recycling in traditional cutting processes. It realizes a closed-loop process of cutting, recycling, and reuse, improves the utilization rate of raw materials, and reduces labor costs.

[0017] The present invention discloses a multi-layer co-extrusion production line for large-diameter pipes. The pipe ring cutting machine has grinding plates on both sides of the cutting blade. Through the cooperation of the compression spring and the wedge-shaped extrusion surface, the rough edges of the cut are ground simultaneously during cutting. The grinding plates automatically adjust the pressure according to the cutting depth, eliminating the need for additional manual or equipment trimming of the cut, thereby improving processing efficiency and reducing the cost of subsequent processes.

[0018] The present invention discloses a multi-layer co-extrusion production line for large-diameter pipes. The elastic dust extraction hood is flexibly connected to the electric telescopic cylinder through an elastic hinge shaft. The elastic pads on the edge can adaptively deform with the diameter of the pipe, which can adapt to pipes of different diameters. At the same time, the feed holes are distributed in an array, which, together with the negative pressure of the annular groove, forms a wrap-around suction force field, and the debris collection efficiency is significantly improved compared with the traditional single-sided dust extraction method. Attached Figure Description

[0019] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0020] Figure 1 This is an isometric view of the present invention;

[0021] Figure 2 This is an isometric view of the fixed frame of the present invention;

[0022] Figure 3 This is a schematic diagram of the cross-sectional structure of the fixed cylinder of the present invention;

[0023] Figure 4 for Figure 1 Enlarged view of region A;

[0024] Figure 5 for Figure 3 Enlarged view of region B;

[0025] Figure 6 This is a schematic cross-sectional view of the recovery pipe of the present invention;

[0026] Figure 7 This is a schematic diagram of the rotating ring structure of the present invention;

[0027] Figure 8 This is a schematic cross-sectional view of the fixed frame structure of the present invention;

[0028] Figure 9 for Figure 7 Enlarged view of region C;

[0029] Figure 10 for Figure 8 Enlarged view of region D;

[0030] Figure 11 This is a schematic diagram of the structure of the electric telescopic cylinder of the present invention.

[0031] In the diagram: 1. Feed hopper; 2. Extrusion unit; 3. Multi-layer co-extrusion die; 4. Tube cooling and shaping device; 5. Fixing frame; 6. Circular through groove; 7. Annular groove; 8. Rotary ring; 9. Flexible dust extraction hood; 10. Recovery pipe; 11. Electric telescopic cylinder; 12. Support plate; 13. Flexible hinge shaft; 14. Feed hole; 15. Connecting pipe; 16. Elastic pad; 17. Fixing cylinder; 18. Sealing plate; 19. Transmission screw; 20. Transmission pulley; 21. Transmission belt; 22. Drive motor; 23. Rotating seat; 24. Negative pressure pipe; 25. Filter screen; 26. First check valve; 27. Hoses; 28. Second check valve; 29. ​​Feed pipe; 30. Pump; 31. Bracket; 32. Shaft; 33. Cutting blade; 34. Power motor; 35. Mounting groove; 36. Grinding plate; 37. Compression spring; 38. Wedge-shaped extrusion surface; 39. Annular guide groove; 40. Annular guide slider; 41. Arc-shaped guide plate; 42. Roller; 43. Connecting rod; 44. Elastic plate; 45. Drive motor; 46. Friction wheel. Detailed Implementation

[0032] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments.

[0033] To achieve a closed-loop process of immediate recycling of cutting debris and direct transport to the feed end, thereby improving processing efficiency and reducing production costs, as one embodiment of the present invention, such as... Figure 1 , Figure 2 , Figure 4 , Figure 7 , Figure 8 , Figure 9As shown, the present invention discloses a multi-layer co-extrusion production line for large-diameter pipes, comprising a feeding hopper 1, an extrusion unit 2 connected to the lower part of the feeding hopper 1, a multi-layer co-extrusion die head 3 and a pipe cooling and shaping device 4 sequentially provided at one end of the extrusion unit 2, a fixing frame 5 provided at one end of the pipe cooling and shaping device 4, the fixing frame 5 being fixedly connected to the pipe cooling and shaping device 4 via a telescopic rod, a circular through groove 6 provided in the middle of the fixing frame 5, an annular groove 7 provided on the inner side of the circular through groove 6, a rotating ring 8 being rotatably connected to the annular groove 7, a pipe ring cutting machine provided on the inner side of the rotating ring 8, elastic dust extraction hoods 9 connected to the interior of the annular groove 7 on both sides of the pipe ring cutting machine, and a recovery pipe 10 connected to the annular groove 7 on one side of the fixing frame 5, the fixed end of the telescopic rod being connected to the interior of the annular groove 7 via the recovery pipe 10, and the recovery pipe 10 being connected to the upper part of the feeding hopper 1 via a feeding pipe 29.

[0034] In use, plastic raw materials are fed into the feeding funnel 1 and fall down under the action of gravity, entering the extrusion unit 2 connected below the feeding funnel 1. The raw materials are melted and plasticized by the extrusion unit 2. After the molten plastic melt is extruded from the extrusion unit 2, it enters the multi-layer co-extrusion die 3 and is extruded through the die outlet to form a pipe blank with a multi-layer structure. The extruded pipe blank enters the pipe cooling and shaping device 4, thereby completing the production of the pipe.

[0035] When the processed pipe enters the circular through groove 6 of the fixed frame 5, the pipe is in a state to be cut. The operator turns on the pipe ring cutting machine and drives the rotating ring 8 to rotate. The rotating ring 8 starts to rotate in a sealed manner in the annular groove 7. The rotation of the rotating ring 8 will drive the pipe ring cutting machine to move around the pipe in a circular motion to cut the pipe, thereby realizing the fixed length cutting of the pipe.

[0036] While cutting, the telescopic rod is activated and begins to extend. During the extension of the telescopic rod, a suction effect is generated in the annular groove 7 through the recovery pipe 10. The elastic dust extraction hood 9 can move together with the pipe ring cutting machine and always maintains contact with the pipe surface during the movement. The debris generated during the cutting process will enter the annular groove 7 through the elastic dust extraction hood 9 under the adsorption effect of the elastic dust extraction hood 9. The debris entering the annular groove 7 is further sucked into the recovery pipe 10 connected to the annular groove 7, which facilitates cutting while extruding during the pipe extrusion molding process, and can also collect the debris generated during cutting in time, avoiding debris flying around and causing pollution.

[0037] After the pipe cutting is completed, the operator turns off the pipe circumferential cutting machine to stop cutting the pipe, and then drives the telescopic rod to perform a reset operation. The telescopic rod drives the fixed frame 5 to move to the initial state until the fixed frame 5 returns to the initial position. During the resetting and shortening process of the telescopic rod, the debris collected in the recycling pipe 10 will be transported to the feed hopper 1 through the feed pipe 29. The debris in the feed hopper 1 will re-enter the extrusion unit 2 and be processed into pipes together with new raw materials, thereby realizing the recycling of raw materials.

[0038] To prevent debris from flying during cutting, for example, such as Figure 7 , Figure 8 , Figure 9 , Figure 10 As shown, the present invention also includes an electric telescopic cylinder 11 fixedly connected to the inner side of the rotating ring 8. The pipe ring cutting machine is fixedly connected to the output end of the electric telescopic cylinder 11 through a support plate 12. The output end of the electric telescopic cylinder 11 is connected to an elastic dust extraction hood 9 through an elastic hinge shaft 13. The elastic dust extraction hood 9 is provided with several sets of feed holes 14 on the side near the pipe ring cutting blade. The side of the elastic dust extraction hood 9 away from the feed holes 14 is connected to a connecting pipe 15. One end of the connecting pipe 15 passes through the rotating ring 8 and communicates with the inside of the annular groove 7.

[0039] A drive motor 45 is provided on the outside of the fixed frame 5. The output end of the drive motor 45 passes through the fixed frame 5 and is fixedly connected to a friction wheel 46. The friction wheel 46 is driven by friction with one side of the rotating ring 8.

[0040] When in use, after the processed pipe is discharged from the pipe cooling and shaping device 4 and enters the circular through groove 6 of the fixed frame 5, the operator starts the pipe ring cutting machine and simultaneously opens the electric telescopic cylinder 11. The output end of the electric telescopic cylinder 11 extends out and drives the pipe ring cutting machine to move towards the pipe through the support plate 12, so that the cutting parts gradually approach the pipe and perform extrusion cutting operation.

[0041] During the advancement of the electric telescopic cylinder 11, the output end drives the elastic dust extraction hood 9 to approach the pipe synchronously through the elastic hinge shaft 13. The elastic pad 16 on the edge of the dust extraction hood fits against the outer wall of the pipe to form a flexible sealing structure, blocking the splash path of the cutting debris. At the same time, the telescopic rod begins to extend at a uniform speed. The recovery pipe 10 and the annular groove 7 are connected internally to generate a negative pressure suction effect in the annular groove 7. Relying on the feed hole 14, the connecting pipe 15 and the annular groove 7, a directional suction force is formed at the feed hole 14, which sucks the cutting debris into the annular groove 7 through the feed hole 14 and the connecting pipe 15 in sequence. Finally, under the suction action, the debris is introduced into the recovery pipe 10, realizing the closed collection of the debris throughout the entire process.

[0042] The friction wheel 46 is driven to rotate by the drive motor 45. When the friction wheel 46 rotates, it rubs against one side of the rotating ring 8, thereby driving the rotating ring 8 and the pipe ring cutting machine to rotate. The pipe ring cutting machine moves around the pipe in a circular motion to cut the pipe and achieve fixed-length cutting of the pipe.

[0043] For example, such as Figure 7 , Figure 9 As shown, the present invention also includes elastic pads 16 fixedly connected to both sides of the elastic dust cover 9.

[0044] When in use, the elastic pad 16 has flexible deformation capability. When the elastic dust hood 9 approaches the pipe with the electric telescopic cylinder 11, the elastic pad 16 can closely adhere to the outer wall of the pipe, fill the gap between the elastic dust hood 9 and the surface of the pipe, form a sealing structure, prevent cutting debris from splashing from the edge gaps into the workshop environment, and avoid contaminating the production space.

[0045] To achieve continuous raw material extrusion while cutting to a fixed length, ensuring the continuity of pipe extrusion production, for example, such as Figure 2 , Figure 3 , Figure 5 As shown, the present invention also includes a telescopic rod comprising a fixed cylinder 17, one end of which is fixedly connected to a pipe cooling and shaping device 4. A sealing plate 18 is slidably connected to the inner side of the fixed cylinder 17. A horizontally arranged transmission screw 19 is rotatably connected to the side of the sealing plate 18 away from the pipe cooling and shaping device 4. One end of the transmission screw 19 passes through the fixed cylinder 17 and is threadedly connected to the fixed cylinder 17. A transmission belt 21 pulley 20 is fixedly connected to the end of the transmission screw 19 away from the sealing plate 18. Adjacent transmission belt 21 pulleys 20 are driven by the transmission belt 21. A drive motor 22 is fixedly connected to one end of the fixed frame 5. The output end of the drive motor 22 is fixedly connected to a set of corresponding transmission screws 19. One end of another set of transmission screws 19 is fixedly connected to one side of the fixed frame 5 through a rotating seat 23.

[0046] During use, when the pipe is being cut, the drive motor 22 at one end of the fixed frame 5 starts, and the drive motor 22 drives the fixed transmission screw 19 to rotate. The transmission screw 19 is threaded to the fixed cylinder 17 and rotates axially. The transmission belt 21 pulley 20 at the end of the screw away from the sealing plate 18 drives the adjacent pulley through the transmission belt 21 to realize the synchronous rotation of another set of transmission screws 19. This set of screws is connected to the side of the fixed frame 5 through the rotating seat 23 to ensure rotational stability.

[0047] The axial movement of the transmission screw 19 drives the sealing plate 18 to slide in the fixed cylinder 17, which expands the volume of the sealed space in the fixed cylinder 17 and reduces the internal air pressure to form a negative pressure. This negative pressure acts on the elastic dust extraction hood 9 through the recovery pipe 10, the annular groove 7 and the connecting pipe 15, causing the feed hole 14 to generate an adsorption force, sucking the cutting debris into the annular groove 7 and guiding it into the recovery pipe 10, effectively preventing the debris from falling into the workshop and preventing pollution of the production environment and equipment failure.

[0048] When the telescopic rod extends, the rotating ring 8 drives the pipe ring cutter to rotate and cut around the pipe. At the same time, the extrusion unit 2 continuously feeds molten raw material to the multi-layer co-extrusion die head 3. The displacement of the transmission screw 19 is controlled by the drive motor 22 to synchronize the cutting position with the pipe extrusion speed. This ensures that the raw material extrusion is not interrupted while achieving fixed-length cutting, thus ensuring the continuity of pipe extrusion production.

[0049] To facilitate the extraction of cutting debris into the recovery tube 10, for example, as shown below. Figure 5 , Figure 6 , Figure 7 As shown, the present invention also includes a fixed end of the fixed cylinder 17 connected to the inside of the recovery pipe 10 through a negative pressure pipe 24, a filter screen plate 25 corresponding to the negative pressure pipe 24 is provided on the inner side of the recovery pipe 10, and a first one-way valve 26 connected to the annular groove 7 is provided on one side of the fixed frame 5. The first one-way valve 26 is connected to one end of the recovery pipe 10 through a hose 27.

[0050] When in use, when the sealing plate 18 of the telescopic rod slides inside the fixed cylinder 17 to expand the volume, the negative pressure inside the fixed cylinder 17 is transmitted to the recovery pipe 10 through the negative pressure pipe 24, generating a negative pressure suction effect. When a negative pressure is formed inside the recovery pipe 10, the first one-way valve 26 opens to form an airflow channel. Under the action of negative pressure, the cutting debris is drawn into the recovery pipe 10 in sequence through the annular groove 7, the first one-way valve 26 and the hose 27, thereby realizing the collection and transportation of debris.

[0051] The filter screen 25 inside the recovery pipe 10 is correspondingly set with the negative pressure pipe 24. When the cutting debris enters the recovery pipe 10 through the negative pressure pipe 24 with the negative pressure airflow, the filter screen 25 can intercept particulate impurities in the debris, preventing particulate impurities from entering the fixed cylinder 17 and blocking the pipeline, thus affecting the negative pressure conduction and debris recovery process.

[0052] For example, such as Figure 1 , Figure 3 , Figure 4 , Figure 5 As shown, the present invention also includes a second one-way valve 28 connected to one end of the recovery pipe 10 away from the hose 27, the second one-way valve 28 being connected to one end of the feeding pipe 29, the other end of the feeding pipe 29 being connected to the top of the feeding funnel 1, and a pumping pump 30 connected to the feeding pipe 29 being provided above the feeding funnel 1.

[0053] During use, after cutting, the drive motor 22 reverses and drives the transmission screw 19 to rotate in the opposite direction, causing the sealing plate 18 to slide towards the pipe cooling and shaping device 4. The internal volume of the fixed cylinder 17 decreases, generating a compressive positive pressure. This positive pressure is transmitted to the recovery pipe 10 through the negative pressure pipe 24, causing the air pressure inside the recovery pipe 10 to rise. This pushes the debris and gas towards the end of the recovery pipe 10 away from the hose 27. At this time, the second one-way valve 28 of the recovery pipe 10 opens under the action of positive pressure, forming a discharge channel. The debris and gas flow through this channel to the feeding pipe 29. As the transmission screw 19 continues to reset, the positive pressure inside the fixed cylinder 17 continuously transports the debris from the end of the feeding pipe 29 to the feeding funnel 1, realizing the automated recycling of cutting debris and the closed-loop utilization of raw materials. The mixing and melting of debris and new raw materials can be completed without manual intervention, significantly improving the utilization rate of raw materials.

[0054] During this process, the suction pump 30 above the feed hopper 1 starts simultaneously, generating additional suction through the feed pipe 29 to help draw the debris from the end of the feed pipe 29 to the feed hopper 1, ensuring that the debris is completely removed from the feed pipe 29, effectively avoiding residue accumulation, and ensuring conveying efficiency and stability.

[0055] To facilitate the processing of the cut surfaces of the pipes, for example, such as Figure 7 , Figure 8 , Figure 9 , Figure 11 As shown, the present invention also includes a pipe circumferential cutting machine comprising a bracket 31 connected to a support plate 12, a rotating shaft 32 rotatably connected to the bracket 31, a cutting blade 33 and a power motor 34 coaxially connected to the rotating shaft 32, the power motor 34 being fixedly connected to the bracket 31, mounting grooves 35 being provided on both sides of the cutting blade 33, a grinding plate 36 being provided in the mounting groove 35, a compression spring 37 being fixedly connected between the grinding plate 36 and the mounting groove 35, and a wedge-shaped compression surface 38 being provided on the edge of the grinding plate 36 away from the axis of the cutting blade 33.

[0056] During use, the power motor 34 drives the rotating shaft 32 and the cutting blade 33 to rotate at high speed. The edge of the cutting blade 33 cuts into the outer wall of the pipe and penetrates deeper into the inner wall. When the cutting depth reaches a certain level, the wedge-shaped extrusion surface 38 on the side of the grinding plate 36 away from the axis of the cutting blade 33 contacts the edge of the pipe cutting surface. At this time, the wedge-shaped extrusion surface 38 and the pipe cutting surface generate extrusion force. Under the action of extrusion force, the grinding plate 36 is pushed to move downward into the mounting groove 35. Since the grinding plate 36 and the mounting groove 35 are connected by the compression spring 37, the movement of the grinding plate 36 will compress the compression spring 37, so that the spring stores elastic potential energy. During the compression process, the compression spring 37 will generate a reverse elastic force on the grinding plate 36, so that the grinding plate 36 maintains the contact pressure with the pipe cutting surface, ensuring that the grinding plate 36 can closely contact the cutting surface. At the same time, the elastic buffering effect of the compression spring 37 can prevent the grinding plate 36 from applying too much impact force to the cutting surface, preventing the pipe surface from being scratched or deformed.

[0057] As the cutting blade 33 continues to penetrate deeper, the grinding plate 36 moves continuously into the mounting groove 35 under the push of the wedge-shaped extrusion surface 38. The surface of the grinding plate 36 gradually covers the cut edge formed by the cutting blade 33. At this time, the grinding plate 36 rotates together with the cutting blade 33. Relying on its own contact friction with the cutting surface, it grinds and repairs the burrs and rough edges of the pipe after cutting. The movement trajectory of the grinding plate 36 is synchronized with the cutting surface, and the newly formed cutting surface can be processed in real time to make the cut surface smooth and flat.

[0058] After the cutting blade 33 completes the circumferential cutting action, the power motor 34 stops running, the cutting blade 33 exits the pipe, at this time, the compression spring 37 releases elastic potential energy, pushes the grinding plate 36 to reset upward along the mounting groove 35, the wedge-shaped extrusion surface 38 separates from the pipe cutting surface, and the grinding plate 36 returns to the initial position, ready for the next cutting and grinding.

[0059] For example, such as Figure 10 As shown, the present invention also includes an annular guide groove 39 provided on the inner side of the annular groove 7, and an annular guide slider 40 provided on the inner side of the rotating ring 8, which is slidably connected to the annular guide groove 39.

[0060] During use, the annular guide slider 40 is embedded in the annular guide groove 39. When the rotating ring 8 drives the pipe circumferential cutting machine to rotate, it ensures that the cutting blade 33 always makes a circular motion around the pipe axis, thereby improving the cutting accuracy.

[0061] For example, such as Figure 2 , Figure 6As shown, the present invention also includes an arc-shaped guide plate 41 at one end of the fixed frame 5 near the pipe cooling and shaping device 4, a plurality of rollers 42 are provided on the inner side of the arc-shaped guide plate 41, and one side of the arc-shaped guide plate 41 is fixedly connected to one side of the fixed frame 5 through a connecting rod 43; and circumferentially distributed elastic plates 44 are provided on the inner side of the circular through groove 6.

[0062] In use, after the pipe is discharged from the cooling and shaping device, it first enters the inner area of ​​the arc-shaped guide plate 41. The curvature of the arc-shaped guide plate 41 matches the diameter of the pipe, forming a guide channel. When the pipe slides along the curvature of the arc-shaped guide plate 41, the inner roller 42 contacts the outer wall of the pipe. The roller 42 can rotate freely around its own axis, and rolling friction replaces sliding friction, reducing wear on the surface of the pipe. The arc-shaped guide plate 41 is rigidly connected to the fixed frame 5 through the connecting rod 43, ensuring stability during the pipe pushing process, avoiding deviation of the guide position, improving positioning and low-damage conveying in the cutting process of large-diameter pipes, and improving the stability of the production line and the quality of finished products.

[0063] The elastic plate 44 makes flexible contact with the surface of the pipe fitting to avoid scratches and indentations, protect the appearance and performance of the pipe fitting, and improve the sealing effect at both ends of the circular through groove 6.

[0064] In use, the plastic raw material is fed into the production line through the feeding funnel 1. The raw material slides down under the action of gravity and enters the extrusion unit 2 below the feeding funnel 1. The extrusion unit 2 heats, melts and plasticizes the raw material to form a uniform molten plastic melt. After the molten plastic melt is extruded from the extrusion unit 2, it enters the multi-layer co-extrusion die 3 and is extruded through the die outlet to form a pipe blank with a multi-layer structure. The extruded pipe blank enters the pipe cooling and shaping device 4 to solidify and shape it.

[0065] After being formed, the tube is discharged from the cooling and shaping device and first enters the inner side of the arc-shaped guide plate 41 near the cooling device end of the fixed frame 5. The curvature of the arc-shaped guide plate 41 matches the diameter of the tube. The inner roller 42 contacts the outer wall of the tube and reduces the wear on the tube surface through rolling friction, guiding the tube smoothly into the circular through groove 6 of the fixed frame 5. After the tube enters the circular through groove 6, the circumferentially distributed elastic plates 44 make flexible contact with the tube surface, which not only avoids scratching the tube, but also improves the sealing effect at both ends of the circular through groove 6, ensuring stability during subsequent cutting.

[0066] The operator starts the electric telescopic cylinder 11, and its output end drives the pipe ring cutting machine to move towards the pipe through the support plate 12, so that the cutting blade 33 gradually approaches the outer wall of the pipe. At the same time, the output end of the electric telescopic cylinder 11 drives the elastic dust extraction hood 9 to move synchronously through the elastic hinge shaft 13. The elastic pads 16 on both sides of the elastic dust extraction hood 9 are tightly attached to the outer wall of the pipe to form a sealing structure to prevent debris from flying.

[0067] The power motor 34 of the pipe circumferential cutting machine is turned on, which drives the rotating shaft 32 and the cutting blade 33 to rotate at high speed. The cutting blade 33 cuts into the outer wall of the pipe and penetrates deeper into the inner wall. At the same time, the transmission motor 45 on the outside of the fixed frame 5 is started. The friction wheel 46 at its output end rubs and drives the rotating ring 8, which rotates in a sealed manner in the annular groove 7, thereby making the pipe circumferential cutting machine move around the pipe to achieve fixed-length cutting.

[0068] During the cutting process, the grinding plates 36 on both sides of the cutting blade 33 move as the cutting depth increases: when the wedge-shaped extrusion surface 38 contacts the edge of the pipe cutting surface, the extrusion force pushes the grinding plate 36 to compress the extrusion spring 37 in the mounting groove 35, so that the grinding plate 36 fits tightly against the cutting surface. The grinding plate 36 rotates with the cutting blade 33 to grind the burrs and rough edges of the cut in real time, ensuring that the cut is smooth and flat.

[0069] Simultaneously with cutting, the drive motor 22 at one end of the fixed frame 5 is started, driving the transmission screw 19 to rotate. Through the threaded engagement, the sealing plate 18 slides inside the fixed cylinder 17, and the internal volume of the fixed cylinder 17 expands to form a negative pressure. The negative pressure is transmitted to the recovery pipe 10 through the negative pressure pipe 24, causing the first one-way valve 26 to open. A suction effect is formed in the annular groove 7. The feed hole 14 of the elastic dust extraction hood 9 is connected to the annular groove 7 through the connecting pipe 15, and the cutting debris is sequentially sucked into the annular groove 7 and the recovery pipe 10. The filter screen 25 intercepts impurities in the debris to prevent clogging of the pipeline. At the same time, the displacement of the transmission screw 19 is controlled by the drive motor 22 to synchronize the cutting position with the pipe extrusion speed, ensuring that the raw material extrusion is not interrupted while cutting to a fixed length.

[0070] After cutting, the drive motor 22 reverses, the transmission screw 19 drives the sealing plate 18 to reset, the volume of the fixed cylinder 17 decreases to generate positive pressure, pushing the debris in the recovery pipe 10 to move towards the second one-way valve 28. The debris and gas flow through this valve to the feeding pipe 29. As the transmission screw 19 continues to reset, the positive pressure in the fixed cylinder 17 continuously transports the debris from the end of the feeding pipe 29 to the feeding funnel 1, realizing the automated recycling of cutting debris and the closed-loop utilization of raw materials. The mixing and melting of debris and new raw materials can be completed without manual intervention, significantly improving the utilization rate of raw materials. During this process, the suction pump 30 above the feeding funnel 1 starts simultaneously, generating additional suction through the feeding pipe 29 to assist in sucking the debris from the end of the feeding pipe 29 to the feeding funnel 1, ensuring that the debris is completely removed from the feeding pipe 29, effectively avoiding residual accumulation, and ensuring conveying efficiency and stability.

[0071] After cutting is completed, the compression spring 37 returns to its original position, the grinding plate 36 returns to its initial position, the telescopic rod fully returns to its original position, and the fixed frame 5 returns to its initial position, waiting for the next section of pipe to be conveyed and cut, and the production line enters the next cycle.

[0072] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of protection claimed by the present invention. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A large-diameter pipe multilayer co-extrusion production line, comprising a feeding hopper (1), a communication of the feeding hopper (1) is connected with an extrusion unit (2), one end of the extrusion unit (2) is sequentially provided with a multilayer co-extrusion die head (3) and a pipe cooling and shaping device (4), characterized in that, One end of the pipe cooling and shaping device (4) is provided with a fixed frame (5), the fixed frame (5) is fixedly connected with the pipe cooling and shaping device (4) through an extension rod, the middle part of the fixed frame (5) is provided with a circular through slot (6), the inner side of the circular through slot (6) is provided with an annular groove (7), the annular groove (7) is sealingly and rotatably connected with a rotating ring (8), the inner side of the rotating ring (8) is provided with a pipe cutting machine, the pipe cutting machine is provided with elastic dust extraction covers (9) on both sides and in communication with the inside of the annular groove (7), one side of the fixed frame (5) is provided with a recovery pipe (10) in communication with the annular groove (7), the fixed end of the extension rod is in communication with the inside of the annular groove (7) through the recovery pipe (10), and the recovery pipe (10) is in communication with the upper side of the feeding hopper (1) through a feeding pipe (29); The extension rod comprises a fixed cylinder (17), one end of the fixed cylinder (17) is fixedly connected with the pipe cooling and shaping device (4), the inner side of the fixed cylinder (17) is sealingly and slidably connected with a sealing plate (18), the side, away from the pipe cooling and shaping device (4), of the sealing plate (18) is rotatably connected with a horizontally arranged transmission screw rod (19), one end of the transmission screw rod (19) penetrates through the fixed cylinder (17) and is threadedly connected with the fixed cylinder (17), the end, away from the sealing plate (18), of the transmission screw rod (19) is fixedly connected with a transmission belt pulley (20), adjacent transmission belt pulleys (20) are in transmission through a transmission belt (21), one end of the fixed frame (5) is fixedly connected with a driving motor (22), the output end of the driving motor (22) is fixedly connected with a group of corresponding transmission screw rods (19), and one end of the other group of transmission screw rods (19) is fixedly connected with one side of the fixed frame (5) through a rotating seat (23).

2. A multi-layer co-extrusion line for large diameter pipes according to claim 1, characterized in that, The inner side of the rotating ring (8) is fixedly connected with an electric telescopic cylinder (11), the pipe cutting machine is fixedly connected with the output end of the electric telescopic cylinder (11) through a supporting plate (12), the output end of the electric telescopic cylinder (11) is connected with the elastic dust extraction cover (9) through an elastic hinged shaft (13), the side, close to the pipe cutting knife, of the elastic dust extraction cover (9) is provided with a plurality of groups of feeding holes (14), the side, away from the feeding holes (14), of the elastic dust extraction cover (9) is communicated with a communication pipe (15), one end of the communication pipe (15) penetrates through the rotating ring (8) and is in communication with the inside of the annular groove (7); The outer side of the fixed frame (5) is provided with a transmission motor (45), the output end of the transmission motor (45) penetrates through the fixed frame (5) and is fixedly connected with a friction wheel (46), and the friction wheel (46) is in friction transmission with one side of the rotating ring (8).

3. A multi-layer co-extrusion line for large diameter pipes according to claim 2, characterized in that, The elastic dust extraction cover (9) is fixedly connected with elastic pads (16) on both sides.

4. A multi-layer co-extrusion line for large diameter pipes according to claim 3, characterized in that, The fixed end of the fixed cylinder (17) is in communication with the inside of the recovery pipe (10) through a negative pressure pipe (24), the inner side of the recovery pipe (10) is provided with a filter screen plate (25) corresponding to the negative pressure pipe (24), one side of the fixed frame (5) is provided with a first check valve (26) in communication with the annular groove (7), and the first check valve (26) is in communication with one end of the recovery pipe (10) through a hose (27).

5. A multi-layer co-extrusion line for large diameter pipes according to claim 4, characterized in that, A second one-way valve (28) is communicated with one end of the recovery pipe (10) away from the hose (27), the second one-way valve (28) is communicated with one end of a feeding pipe (29), the other end of the feeding pipe (29) is communicated with the upper side of the feeding hopper (1), the upper side of the feeding hopper (1) is provided with a material pumping pump (30) communicated with the feeding pipe (29).

6. A multi-layer co-extrusion line for large diameter pipes according to claim 5, characterized in that, The pipe cutting machine comprises a bracket (31) connected with the support plate (12), a rotating shaft (32) connected with the bracket (31), a cutting knife (33) and a power motor (34) coaxially connected with the rotating shaft (32), the power motor (34) is fixedly connected with the bracket (31), installation grooves (35) are arranged on both sides of the cutting knife (33), polishing plates (36) are arranged in the installation grooves (35), extrusion springs (37) are fixedly connected between the polishing plates (36) and the installation grooves (35), and wedge-shaped extrusion surfaces (38) are arranged on edges of the polishing plates (36) away from the axis of the cutting knife (33).

7. A multi-layer co-extrusion line for large diameter pipes according to claim 6, characterized in that, The inner side of the annular groove (7) is provided with an annular guide sliding groove (39), and the inner side of the rotating ring (8) is provided with an annular guide sliding block (40) in sliding connection with the annular guide sliding groove (39).

8. A multi-layer co-extrusion line for large diameter pipes according to claim 7, characterized in that, One end of the fixed frame (5) close to the pipe cooling and shaping device (4) is provided with an arc-shaped guide plate (41), the inner side of the arc-shaped guide plate (41) is provided with a plurality of groups of rollers (42), and one side of the arc-shaped guide plate (41) is fixedly connected with one side of the fixed frame (5) through a connecting rod (43); the inner side of the circular through groove (6) is provided with circumferentially distributed elastic plates (44).

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