Three-layer continuous composite pipe forming equipment and method

Abstract

The invention discloses forming equipment and method for a three-layer continuous composite pipe, and relates to the technical field of composite pipe machining, the forming equipment comprises an extruder, a traction machine, a winding machine and a coating machine, the extruder extrudes and forms an inner layer, the inner layer is dragged by the traction machine to the winding machine to be wound and formed into a middle layer, and then the inner layer is dragged by the traction machine to the coating machine to be coated and formed into an outer layer. The three-layer continuous composite pipe is sequentially formed in a layered mode through three forming methods, an automatic production line can be achieved through traction of an auxiliary device traction machine, the working efficiency is improved, and most labor cost is saved; the outer layer adopts dip-coating and roll-coating processes, so that the coating area is large, the efficiency is high, and compared with extrusion molding, the process is more convenient and quicker.

Description

Technical Field

[0001] The present invention belongs to the technical field of composite pipe processing, and particularly relates to a three-layer continuous composite pipe forming device and method. Background Art

[0002] In recent years, China has been facing huge resource and environmental pressures and challenges. With the accelerating speed of energy consumption, ensuring the timely supply of energy has become a determining factor for the sustainable development of China's economy and industry. Pipeline transportation is one of the important ways of energy transportation in China. It is an important means for transporting major energy substances such as oil, geothermal energy, and natural gas, and is even the lifeline for developing new energy in offshore oil and gas fields. Its quality plays a crucial role in the development, production, and transportation of oil and gas fields.

[0003] Currently, the pipelines in use include metal pipelines, non-metal pipelines, and composite pipelines. Metal pipelines have a long history of use and have advantages such as low manufacturing cost and high stiffness. However, they have many fatal defects, such as short working life, high maintenance cost, and easy corrosion, which make it impossible for them to be used in harsh environments for a long time. In contrast, non-metal pipelines avoid these problems. Their good corrosion resistance not only solves the transportation leakage caused by the corrosion of metal pipelines but also saves energy consumption. However, their disadvantages such as low strength and poor stiffness result in their inability to bear huge loads, which limits their use in transporting oil and gas. Therefore, a composite pipeline composed of metal or non-metal and polymer materials has been developed. This new type of composite pipeline can make up for the deficiencies of the raw materials themselves, produce excellent properties that meet the requirements, reduce the occupation of land resources, and significantly reduce energy consumption on the premise of ensuring transportation capacity, thereby accelerating the development of oil and gas extraction technology towards deep water and ultra-deep water.

[0004] Nowadays, there are various types of composite pipes, but most of them are two-layer structures. When facing some harsh environments, their service lives are mostly not long. Moreover, as the structure of the composite pipe becomes more complex, the traditional composite pipe forming methods and their equipment have limitations on the length of the composite pipe, are time-consuming and laborious, have low production efficiency, and high labor and maintenance costs, and cannot meet the needs of the general environment. Summary of the Invention

[0005] In order to overcome the above-mentioned defects existing in the prior art, the present invention provides a three-layer continuous composite pipe forming device.

[0006] The technical solution adopted by the present invention to solve its technical problems is as follows: a three-layer continuous composite pipe forming device, the three-layer continuous composite pipe includes an inner layer, an intermediate layer and an outer layer, and the forming device includes an extruder, a winding machine, a tractor and a coating machine. Two tractors are arranged on the right side of the extruder, the winding machine is arranged between the two tractors, and the coating machine is arranged on the right side of the right tractor. The extruder extrudes and forms the inner layer, which is drawn by the tractor to the winding machine to wind and form the intermediate layer, and then drawn by the tractor to the coating machine to coat and form the outer layer.

[0007] Preferably, the extruder includes an extruder motor box, a coupling, bearings, a screw, a feed hopper, an extruder housing, an extruder head, a filter plate, a flow dividing cone, a mandrel, a die and a sizing sleeve. The extruder motor box and the screw are connected by a coupling. Two bearings are sleeved on the screw and fixed by bearing seats. The extruder housing is wrapped outside the screw and fixed by an extruder bracket. There is an opening above the front end of the extruder housing and the opening communicates with the feed hopper. A heating device is also fixed on the extruder housing to turn the material into a molten state. The right end of the extruder housing and the extruder head are connected by screws. The flow dividing cone and the mandrel are connected by threads and are arranged in the extruder head together with the die. The end of the die is connected to the sizing sleeve by screws. The sizing sleeve is used to further accurately determine the outer diameter of the pipe.

[0008] Preferably, there are two air vents in the middle of the extruder head, and there are also two air vents with the same diameter in the flow dividing cone. The air vents of the extruder head and the flow dividing cone correspond to each other. The center of the flow dividing cone and the mandrel is penetrated, and the penetrated parts correspond to each other. The air holes are used to inject compressed gas to assist the sizing sleeve to accurately determine the outer diameter of the pipe. There are six symmetrically arranged openings at the end of the extruder head, and six adjusting bolts are embedded in the holes to adjust the gap between the mandrel and the die and roughly determine the outer diameter of the pipe.

[0009] Preferably, the tractor includes a tractor motor box, a gear box, a column, a roller, a belt and a protective device. The tractor motor box is located at the bottom. The column and the gear box are connected above the tractor motor box. The column is embedded in the protective device to support the protective device. The protective device includes an upper protective device and a lower protective device. The belt includes an upper belt and a lower belt. Two rollers are respectively arranged on the upper protective device and the lower protective device. An upper belt is connected between the two rollers of the upper protective device, and a lower belt is connected between the two rollers of the lower protective device. A rotating shaft is arranged in the protective device. The gear box extends into the protective device and is connected to the rotating shaft. One end of the rotating shaft extends out of the protective device and is connected to the roller. The tractor motor box makes the gears in the gear box move to drive the roller to rotate.

[0010] Preferably, the winding machine includes a guide ring, a pulley, an orbital disc, corner guide wheels, yarn carriers, a cover plate, and a hexagonal base plate. The hexagonal base plate has 18 symmetrically arranged holes for installing the orbital disc and the corner guide wheels. The cover plate is correspondingly provided with the same 18 holes. The center of the orbital disc is provided with a hole. The shaft of the corner guide wheel passes through the holes of the hexagonal base plate, the cover plate, and the orbital disc and is key-connected to the hole of the pulley. There are 18 groups of such key connection combinations in total. Two yarn carriers are inlaid on each corner guide wheel, and the bottom of the yarn carrier moves in the groove of the orbital disc, and this groove is used to determine the movement trajectory of the yarn carrier.

[0011] Preferably, a bearing sleeve is inlaid on the shaft of the corner guide wheel, and two winding machine bearings are inlaid inside the bearing sleeve. The two bearings are fixed by a shaft collar. The corner guide wheel is installed into the holes of the hexagonal base plate and the cover plate through the bearing sleeve. A mandrel is installed on the right side of the hexagonal base plate, and the mandrel is coaxially arranged with the hexagonal base plate, and the right end of the mandrel is supported by the guide ring.

[0012] Preferably, the coating machine includes a coating machine bracket, a fixing plate, a storage tank, a feed pipe, an electric pump box, a trough cover, a roller brush, a trough, a sizing ring, a coating machine motor, and a crawler. The coating machine bracket includes four columns and two square frames. The two square frames are located inside the four columns and are arranged vertically to connect the four columns. The tops of the four columns are fixedly installed with a fixing plate, and the fixing plate constitutes the top surface of the coating machine. The bottoms of the four columns are fixed with a bottom plate. The storage tank and the coating machine motor are installed on the fixing plate. Another storage tank, the electric pump box, and the coating machine motor are installed on the bottom plate. The trough is arranged inside the square frame. The top and bottom of the trough are fixedly installed with trough covers by bolts, that is, a trough is sandwiched between two trough covers. The storage tank on the fixing plate is connected to the top trough cover through a feed pipe. The storage tank on the bottom plate is connected to the electric pump box, and the electric pump box is connected to the bottom trough cover through a feed pipe.

[0013] Preferably, two rows of roller brushes are arranged in the trough, and the semi-finished composite pipe passes through the middle of the two rows of brushes. The shafts of the roller brushes pass through the trough and the square frame respectively and are connected to a large pulley. The large pulley is connected to a small pulley through a crawler, and the small pulley is sleeved on the coating machine motor. Specifically, after the shaft of the upper row of roller brushes passes out of the trough and passes through the upper square frame, it is connected to the coating machine motor on the fixing plate through a large pulley, a crawler, and a small pulley. After the shaft of the lower row of roller brushes passes out of the trough and passes through the lower square frame, it is connected to the coating machine motor on the bottom plate through a large pulley, a crawler, and a small pulley.

[0014] Preferably, an inlet and an outlet are respectively arranged on both sides of the trough. An inlet sizing ring is arranged outside the trough at the inlet, and an outlet sizing ring is arranged outside the outlet. The inlet sizing ring and the outlet sizing ring are fixed on the coating machine bracket. The inlet sizing ring is used to determine the outer diameter of the intermediate layer, and the outlet sizing ring is used to determine the outer diameter of the outer layer.

[0015] Preferably, the outlet sizing ring includes a vacuum extraction ring connected to the outlet and a cooling ring located behind the vacuum extraction ring and communicating with the center of the vacuum extraction ring; the vacuum extraction ring includes an inner ring and an outer ring, a vacuum extraction cavity is formed between the inner ring and the outer ring, a plurality of through holes are uniformly arranged on the peripheral wall of the inner ring, a vacuum extraction port communicating with the vacuum extraction cavity is arranged on the side wall of the outer ring, and both ends of the inner ring and the outer ring are fixedly connected by end plates; a cooling cavity is formed inside the wall of the cooling ring, and a water inlet and a water outlet communicating with the outside are arranged at both ends of the cooling cavity. The composite pipe coated to form the outer layer enters the vacuum extraction ring for outer layer sizing. Acting on the composite pipe through the through holes, the vacuum sizing strength of the composite pipe can be controlled. At the same time, a pressure difference is formed by vacuum extraction, so that the bubbles formed during the coating process expand and move towards the outer surface and finally burst. The cooled composite pipe is cooled by setting the cooling ring.

[0016] Preferably, the inner ring and the outer ring are connected by detachable buckles. A plurality of clamping columns are uniformly protruded on the outer side of the peripheral wall of the inner ring. A plurality of protrusions are arranged axially along the outer periphery of the clamping columns. A plurality of clamping grooves are uniformly protruded on the peripheral wall of the outer ring. A plurality of recesses are arranged axially on the side wall of the clamping groove. The clamping columns are inserted into the clamping grooves so that the protrusions are engaged with the recesses to realize the connection between the inner ring and the outer ring. By setting the detachable buckle structure, the operator can replace the inner ring with a corresponding size according to the required outer diameter of the coating, and adjust the matching position of the protrusions and the recesses to fix the inner ring and the outer ring, solving the problem of single size and non-adjustability of the sizing ring in the prior art. Among them, both the inner ring and the outer ring are composed of two half rings.

[0017] The technical solution provided by the present invention has the following beneficial effects compared with the prior art:

[0018] 1. Most of the existing technologies are applied to the forming of double-layer continuous composite pipes. The three-layer composite pipe developed by the present invention is applicable to more severe environments and has a wider application range. The inner layer of the three-layer structure can select appropriate wear-resistant and corrosion-resistant materials according to the actual transported liquid or gas; the middle layer is a reinforcing layer mainly for heat insulation, generally made of materials with good heat insulation performance, such as fibers, ultra-high molecular weight polyethylene, etc. The reinforcing layer can also be designed with a multi-layer structure according to the pressure grade; the outer layer mainly plays a role in protecting against scratches and static electricity, which can increase the service life of the composite pipe.

[0019] 2. Nowadays, the forming method of multi-layer composite pipes is mostly co-extrusion forming. Multiple extruders co-extrude multiple layers on one die head. It is easy to be blocked after multiple materials are extruded. The die head structure is complex and inconvenient to maintain, and high precision requirements are required for the simultaneous extrusion equipment. The three-layer forming method of the design scheme of the present invention is respectively: extrusion forming, winding forming and coating forming. The three forming machines work independently of each other without interference. Only one piece of equipment needs to be repaired when problems occur.

[0020] 3. Most of the current methods for forming the outer layer are the same as those for the inner layer, i.e., extrusion molding. This requires subsequent lamination with the inner layer after molding and increases the cost of an extruder and a die head. The present invention employs dip coating and roll coating in coating molding, combining the advantages of large coating area and high efficiency of both, which is more convenient and faster than extrusion molding.

[0021] 4. A vacuum ring is used for sizing the outer layer. Acting on the composite pipe through the through holes, it can control the vacuum sizing strength of the composite pipe. At the same time, a pressure difference is formed by vacuum pumping, causing the bubbles formed during the coating process to expand and move towards the outer surface and finally burst. By setting a detachable snap structure, the operator can replace the inner ring with a corresponding size according to the required outer diameter of the coating, and adjust the matching position of the protrusions and recesses to fix the inner ring and the outer ring, solving the problem of single and non-adjustable sizing ring size in the prior art.

[0022] 5. In the existing technology, the inner layer, the middle layer and the outer layer are respectively formed and finally laminated. In the process flow of the present invention, after the inner layer is formed, it is immediately transported to the winding machine by a tractor and directly wound on the inner layer. The same applies to the outer layer. This saves the lamination step and greatly improves the production efficiency.

[0023] 6. In the process flow of the present invention, the layers are pulled by an auxiliary device, the tractor, without manual operation to achieve semi-automation, improving the production efficiency and saving labor costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a half-sectional view of the overall device for forming a continuous composite pipe according to the present invention;

[0025] Figure 2 is an oblique view of the overall device for forming a continuous composite pipe according to the present invention;

[0026] Figure 3 is a schematic structural view of the extruder according to the present invention;

[0027] Figure 4 is a partially enlarged view of part A of the extruder according to the present invention;

[0028] Figure 5 is a schematic structural view of the winding machine according to the present invention;

[0029] Figure 6 is a partially enlarged view of part B of the winding machine according to the present invention;

[0030] Figure 7 is an oblique view of the coating machine according to the present invention;

[0031] Figure 8 is a schematic structural view of the coating machine according to the present invention;

[0032] Figure 9This is a partial enlarged view of coater C of the present invention;

[0033] Figure 10 This is a partial enlarged view of coater D of the present invention;

[0034] Figure 11 This is a preferred embodiment of the sizing ring of the present invention;

[0035] Figure 12 This is a schematic structural view of the tractor of the present invention;

[0036] Figure 13 This is a side view of the tractor of the present invention.

[0037] In the figure: 1 - extruder motor box; 2 - coupling; 3 - bearing seat; 4 - bearing; 5 - screw; 6 - feed hopper; 7 - heating device; 8 - extruder support; 9 - extruder housing; 10 - filter plate; 11 - extruder head; 12 - flow dividing cone; 13 - mandrel; 14 - adjusting bolt; 15 - die; 16 - sizing sleeve; 17 - composite pipe; 18 - belt pulley; 19 - hexagonal base plate; 20 - cover plate; 21 - rolling bearing; 22 - shaft collar; 23 - bearing sleeve; 24 - track plate; 25 - angle guide wheel; 26 - yarn carrier; 27 - guide ring; 28 - tractor motor box; 29 - gear box; 30 - roller; 31 - column; 32 - belt; 33 - protective device; 34 - cushion table; 35 - coater support; 36 - storage tank; 37 - inlet sizing ring; 38 - fixing plate; 39 - feed pipe; 40 - electric pump box; 41 - trough cover; 42 - roller brush; 43 - trough; 44 - coater motor; 45 - crawler; 46 - small belt pulley; 47 - large belt pulley; 48 - outer ring; 49 - inner ring; 50 - end plate; 51 - cooling ring. Detailed implementation manners

[0038] To make the objectives, technical solutions and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are some but not all of the embodiments of this application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in this application without creative efforts shall fall within the scope of protection of this application.

[0039] The following further elaborates on the embodiments of the present invention with reference to the accompanying drawings.

[0040] Please refer to Figures 1-13, the present invention provides a three - layer continuous composite pipe forming device. The three - layer continuous composite pipe includes an inner layer, an intermediate layer, and an outer layer. The forming device includes an extruder, a winding machine, a tractor, and a coating machine. Two tractors are arranged on the right side of the extruder. The winding machine is arranged between the two tractors. The coating machine is arranged on the right side of the right tractor. The extruder extrudes and forms the inner layer, which is then pulled by the tractor to the winding machine to wind and form the intermediate layer, and then pulled by the tractor to the coating machine to coat and form the outer layer.

[0041] Preferably, the extruder includes an extruder motor box 1, a coupling 2, bearings 4, a screw 5, a feed hopper 6, an extruder housing 9, an extruder head 11, a filter plate 10, a flow - dividing cone 12, a mandrel 13, a die 15, and a sizing sleeve 16. The extruder motor box 1 and the screw 4 are connected by the coupling 2. Two bearings 4 are sleeved on the screw 5 and fixed by bearing seats 3. The extruder housing 9 wraps around the outside of the screw 5 and is fixed by an extruder bracket 8. There is an opening above the front end of the extruder housing 9, and the opening communicates with the feed hopper 6. A heating device 7 is also fixed on the extruder housing 9 to turn the material into a molten state. The right end of the extruder housing 9 and the extruder head 11 are connected by screws. The flow - dividing cone 12 and the mandrel 13 are connected by threads and are arranged together with the die 15 inside the extruder head 11. The end of the die 15 and the sizing sleeve 16 are connected together by screws. The sizing sleeve 16 is used to further accurately determine the outer diameter of the pipe.

[0042] Preferably, there are two vent holes in the middle of the extruder head 11. There are also two vent holes with the same diameter inside the flow - dividing cone 12. The vent holes of the extruder head 11 and the flow - dividing cone 12 correspond to each other. The center of the flow - dividing cone 12 and the mandrel 13 is penetrated, and the penetrated parts correspond to each other. The vent holes are used to inject compressed gas to assist the sizing sleeve 16 in accurately determining the outer diameter of the pipe. There are six symmetrically arranged openings at the end of the extruder head 11, and six adjusting bolts 14 are embedded in the openings to adjust the gap between the mandrel 13 and the die 15 and roughly determine the outer diameter of the pipe.

[0043] Preferably, the tractor includes a tractor motor box 28, a gear box 29, a column 31, a roller 30, a belt 32 and a protection device 33. The tractor motor box 28 is located at the bottom. The column 31 and the gear box 29 are connected above the tractor motor box 28. The column 31 is embedded in the protection device to support the protection device 33. The protection device 33 includes an upper protection device and a lower protection device. The belt 32 includes an upper belt and a lower belt. Two rollers 30 are respectively arranged on the upper protection device and the lower protection device. An upper belt is connected between the two rollers 30 of the upper protection device, and a lower belt is connected between the two rollers 30 of the lower protection device. A rotating shaft is arranged in the protection device 33. The gear box 29 extends into the protection device 33 and is connected to the rotating shaft. One end of the rotating shaft extends outside the protection device 33 and is connected to the roller 30. The tractor motor box 28 makes the gears in the gear box move, thereby driving the roller to rotate. The composite pipe 17 passes through between the belt and the lower belt.

[0044] Preferably, the winding machine includes a guide ring 27, a pulley 18, an orbital disc 24, an angle guide wheel 25, a yarn carrier 26, a cover plate 20 and a hexagonal base plate 19. The hexagonal base plate 19 has 18 symmetrically arranged holes for installing the orbital disc 24 and the angle guide wheel 25. The cover plate 20 is correspondingly provided with the same 18 holes. A hole is arranged in the center of the orbital disc. The shaft of the angle guide wheel 25 passes through the holes of the hexagonal base plate 19, the cover plate 20, the orbital disc 24 and the hole of the pulley 18 and is connected together by a key. There are 18 groups of such key connection combinations. Two yarn carriers 26 are embedded on each angle guide wheel 35. The bottom of the yarn carrier 26 moves in the groove of the orbital disc 24, and this groove is used to determine the movement track of the yarn carrier.

[0045] Preferably, a bearing sleeve 23 is embedded on the shaft of the angle guide wheel 25. Two winding machine bearings 21 are embedded inside the bearing sleeve 23. The two bearings 21 are fixed by a shaft collar 22. The angle guide wheel 25 is installed in the holes of the hexagonal base plate 19 and the cover plate 20 through the bearing sleeve 23. A mandrel is installed on the right side of the hexagonal base plate 19. The mandrel is coaxially arranged with the hexagonal base plate 19. The right end of the mandrel is supported by the guide ring 27.

[0046] Preferably, the coater includes a coater support 35, a fixing plate 38, a storage tank 36, a feed pipe 39, an electric pump box 40, a trough cover 41, a roller brush 42, a trough 43, an inlet sizing ring 37, a coater motor 44, and a crawler 45. The coater support 35 includes four columns and two square frames. The two square frames are located inside the four columns and are arranged vertically to connect the four columns. At the top of the four columns, a fixing plate 38 is fixedly installed, and the fixing plate 38 forms the top surface of the coater. At the bottom of the four columns, a bottom plate is fixed. On the fixing plate 38, a storage tank 36 and a coating machine motor 44 are installed. On the bottom plate, another storage tank 36, an electric pump box 40, and a coating machine motor 44 are installed. The trough 43 is arranged inside the square frame. The top and bottom of the trough 43 are fixedly installed with trough covers 41 through bolts, that is, a trough 43 is sandwiched between two trough covers 41. The storage tank 36 on the fixing plate 38 is connected to the top trough cover 41 through a feed pipe 39. The storage tank 36 on the bottom plate is connected to the electric pump box 40, and the electric pump box 40 is connected to the bottom trough cover 41 through a feed pipe 39.

[0047] Preferably, two rows of roller brushes 42 are arranged up and down in the trough 43. The composite pipe semi-finished product passes through the middle of the two rows of brushes. The shafts of the roller brushes 42 pass through the trough 43 and the square frame respectively and then are connected to a large pulley 47. The large pulley 47 is connected to a small pulley 46 through a crawler 45, and the small pulley 46 is sleeved on the coater motor 44. Specifically, after the shaft of the upper row of roller brushes 42 passes out of the trough and passes through the upper square frame, it is connected to the coater motor 44 on the fixing plate 38 through the large pulley 47, the crawler 45, and the small pulley 46. After the shaft of the lower row of roller brushes 42 passes out of the trough and passes through the lower square frame, it is connected to the coater motor 44 on the bottom plate through the large pulley 47, the crawler 45, and the small pulley 46. After the composite pipe semi-finished product enters the trough, it is completely immersed in the coating material, and the two rows of roller brushes roll-coat it, enabling the coating material to be quickly and evenly coated to form an outer layer.

[0048] Preferably, an inlet and an outlet are respectively arranged on both sides of the trough 43. An inlet sizing ring 37 is arranged outside the inlet of the trough 43, and an outlet sizing ring is arranged outside the outlet. The inlet sizing ring 37 and the outlet sizing ring are fixed on the coater support 35. The inlet sizing ring 37 is used to determine the outer diameter of the intermediate layer, and the outlet sizing ring is used to determine the outer diameter of the outer layer.

[0049] Preferably, the outlet sizing ring includes a vacuum extraction ring connected to the outlet, and a cooling ring 51 located behind the vacuum extraction ring and communicating with the center of the vacuum extraction ring; the vacuum extraction ring includes an inner ring 49 and an outer ring 48, a vacuum extraction cavity is formed between the inner ring 49 and the outer ring 48, a plurality of through holes are uniformly arranged on the peripheral wall of the inner ring 49, a vacuum extraction port communicating with the vacuum extraction cavity is arranged on the side wall of the outer ring 48, and both ends of the inner ring 49 and the outer ring 48 are fixedly connected by an end plate 50; a cooling cavity is formed inside the ring wall of the cooling ring 51, and a water inlet and a water outlet communicating with the outside are arranged at both ends of the cooling cavity. The composite pipe coated to form the outer layer enters the vacuum extraction ring for outer layer sizing. Acting on the composite pipe through the through holes, the vacuum sizing strength of the composite pipe can be controlled. At the same time, a pressure difference is formed by vacuum extraction, so that the bubbles formed during the coating process expand and move towards the outer surface and finally burst. The cooled composite pipe after vacuum extraction is cooled by setting the cooling ring.

[0050] Preferably, the inner ring 49 and the outer ring 48 are detachably connected by snap fasteners. A plurality of clamping columns are uniformly protruded on the outer side of the peripheral wall of the inner ring 49. A plurality of protrusions are arranged axially along the outer periphery of the clamping columns. A plurality of clamping grooves are uniformly protruded on the peripheral wall of the outer ring 48. A plurality of concave portions are arranged axially on the side wall of the clamping groove. The clamping columns are inserted into the clamping grooves so that the protrusions are engaged with the concave portions to realize the connection between the inner ring 49 and the outer ring 48. By setting the detachable snap-fastener structure, the operator can replace the inner ring with a corresponding size according to the required outer diameter of the coating, and adjust the matching position of the protrusions and the concave portions to fix the inner ring and the outer ring, solving the problem of single size and non-adjustability of the sizing ring in the prior art. Among them, both the inner ring 49 and the outer ring 48 are composed of two semi-rings.

[0051] Working principle: The extruder is responsible for turning the material into a molten state and pushing the molten material into the extruder head. The inner layer is formed in the gap between the die and the mandrel in the extruder head. The formed inner layer is sized and cooled accurately by the sizing sleeve, and then is pulled by the tractor to the winding machine. The belt pulley of the winding machine rotates to drive the yarn carrier on the angle guide wheel to rotate along the track of the track plate. The fiber on the yarn carrier is fixed on the inner layer through the guide ring and wound into the middle layer by rotation to form a semi-finished product tube. Then it is pulled by the tractor to the coating machine. The coating in the storage tank enters the trough. The motor of the coating machine drives the roller brush to rotate. When the semi-finished product tube passes through the trough, the coating is applied on it to form the outer layer, and then sizing is achieved through vacuum extraction and cooling.

[0052] It should be noted that in this application, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising one" does not exclude the presence of additional identical elements in the process, method, article or device comprising said element.

[0053] The above are only specific embodiments of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application will not be limited to these embodiments shown herein, but rather will conform to the broadest scope consistent with the principles and novel features claimed herein.

Claims

1. A three-layer continuous composite tube forming device, the three-layer continuous composite tube comprising an inner layer, an intermediate layer and an outer layer, characterized in that: The molding equipment includes an extruder, a winding machine, a traction machine and a coating machine. Two traction machines are arranged on the right side of the extruder, the winding machine is arranged in the middle of the two traction machines, and the coating machine is arranged on the right side of the right traction machine. The extruder extrude and form the inner layer, which is then pulled by the traction machine to the winding machine to form the middle layer, and then pulled by the traction machine to the coating machine to form the outer layer by coating.

2. The three-layer continuous composite tube forming equipment according to claim 1, characterized in that: The coating machine includes a coating machine bracket, a material trough is arranged in the coating machine bracket, the storage tank is connected with the material trough through a feeding pipe, and two rows of upper and lower roller brushes are arranged in the material trough. The composite pipe semi-finished product passes through the middle of the two rows of brushes. The shaft of the roller brush passes through the material trough and is connected to a large pulley. The large pulley is connected to the small pulley through a crawler track, and the small pulley is sleeved on the coating machine motor.

3. The three-layer continuous composite tube forming equipment according to claim 2 is characterized in that: An inlet and an outlet are respectively arranged on both sides of the material trough, an inlet sizing ring is arranged on the outside of the material trough, and an outlet sizing ring is arranged on the outside of the outlet. The inlet sizing ring and the outlet sizing ring are fixed on the coating machine bracket. The inlet sizing ring is used to determine the outer diameter of the middle layer, and the outlet sizing ring is used to determine the outer diameter of the outer layer.

4. The three-layer continuous composite tube forming equipment according to claim 2, characterized in that: The coating machine bracket includes four columns and two square frames. The two square frames are located in the four columns and are arranged up and down. A fixing plate is fixedly installed on the top of the four columns, and a bottom plate is fixedly installed on the bottom of the four columns. A storage tank and a coating machine motor are installed on the fixed plate, and another storage tank, an electric pump box and a coating machine motor are installed on the bottom plate. The material trough is arranged in the square frame, and a material trough cover is fixedly installed on the top and bottom of the material trough by bolts. The material storage tank on the fixed plate is connected to the top material trough cover through a feed pipe, the material storage tank on the bottom plate is connected to the electric pump box, and the electric pump box is connected to the bottom material trough cover through a feed pipe.

5. The three-layer continuous composite tube forming equipment according to claim 4 is characterized in that: After the shaft of the upper row of roller brushes passes through the material trough and the upper square frame, it is connected to the coating machine motor on the fixed plate through a large pulley, a crawler track and a small pulley. After the shaft of the lower row of roller brushes passes through the material trough and the lower square frame, it is connected to the coating machine motor on the bottom plate through a large pulley, a crawler track and a small pulley.

6. The three-layer continuous composite tube forming equipment according to claim 3 is characterized in that: The outlet sizing ring includes a vacuum ring connected to the outlet and a cooling ring located at the rear side of the vacuum ring and connected to the center of the vacuum ring; the vacuum ring includes an inner ring and an outer ring, a vacuum cavity is formed between the inner ring and the outer ring, and the inner ring and the outer ring are connected by a detachable snap buckle.

7. The three-layer continuous composite tube forming equipment according to claim 6, characterized in that: The outer side of the inner ring's circumferential wall is evenly provided with a plurality of clamping columns, and a plurality of protrusions are axially arranged on the outer circumference of the clamping columns. The outer ring's circumferential wall is evenly provided with a plurality of clamping grooves, and a plurality of recesses are axially arranged on the side walls of the clamping grooves. The clamping columns are inserted into the clamping grooves so that the protrusions are engaged with the recesses. Both the outer ring and the inner ring are composed of two half rings.

8. The three-layer continuous composite tube forming equipment according to claim 1, characterized in that: The extruder comprises a screw, a feed hopper, an extruder housing, an extruder head, a filter plate, a diverter cone, a core rod, a die and a sizing sleeve. The extruder housing is wrapped around the outside of the screw, an opening is arranged above the extruder housing and the opening is communicated with the feed hopper, a heating device is fixed on the extruder housing for molten material, the right end of the extruder housing is connected to the extruder head, the diverter cone and the core rod are connected by threads and are arranged in the extruder head together with the die, the end of the die is connected to the sizing sleeve by screws, and the sizing sleeve is used to further accurately determine the outer diameter of the pipe.

9. The three-layer continuous composite tube forming equipment according to claim 6, characterized in that: There are two air vents in the middle of the extruder head, and there are also two air vents with the same diameter in the diverter cone. The air vents of the extruder head and the diverter cone correspond to each other, and the diverter cone and the center of the mandrel are penetrated, and the penetrated parts correspond to each other. The air vents are used to inject compressed gas to assist the sizing sleeve in accurately determining the outer diameter of the tube. There are six symmetrical openings at the end of the extruder head, and six adjusting bolts are embedded in the holes to adjust the gap between the mandrel and the die and roughly determine the outer diameter of the tube.

10. A method for forming a three-layer continuous composite pipe, using the three-layer continuous composite pipe forming equipment according to any one of claims 1 to 9, the three-layer continuous composite pipe comprising an inner layer, a middle layer and an outer layer, the inner layer is extruded by an extruder, the middle layer is pulled by a traction machine to a winding machine to wind and form the middle layer, and the outer layer is pulled by the traction machine to a coating machine to coat and form the outer layer.

Images