Large-diameter polyethylene elbow winding manufacturing process and equipment

Abstract

The application discloses a kind of winding production equipment and process of large-diameter polyethylene elbow, and high-efficiency precision forming is realized by innovative structure. The equipment includes a workbench, a horizontal rotating table and a vertical lifting table are arranged on the workbench, the rotating table is installed with an inner mold mounting seat movable along the inner mold mounting frame, the inner mold mounting seat is hinged with a deflectable adjustable inner mold, the angle is adjusted by driving the deflection shaft with a third motor, the lifting table is provided with a multidirectional adjusting extruder to ensure the adaptation with the inner mold. The inner mold is designed in a nodular manner, and is connected by a plurality of unit molds through a mold core. Each unit contains two sets of half-round mold plates that can be opened and closed. The half-round mold plates are linked with adjusting sliders through parallelogram supports to realize contraction or opening. A seventh motor controls the opening and closing angle. The process flow is: assembling the inner mold → adjusting the position → extruding and winding → adjusting section by section → demolding and taking the part. The application solves the problem of large-diameter polyethylene elbow production, reduces the cost, improves the efficiency and quality, and promotes the application of polyethylene pipeline.

Description

Technical Field

[0001] This invention relates to the field of pipe elbow processing technology, specifically a winding process and equipment for manufacturing large-diameter polyethylene elbows. Background Technology

[0002] In the current pipeline industry, compared to traditional pipes such as steel pipes, cast iron pipes, cement pipes, and fiberglass pipes, polyethylene pipes exhibit significant technological advantages, specifically in terms of good flexibility, strong corrosion resistance, bendability, and wear resistance. For large-diameter polyethylene pipes exceeding 1.6 meters in diameter, direct extrusion is neither economical nor practical; therefore, a method of spiral winding steel wire-reinforced polyethylene strip is typically used. Currently, this process is only suitable for producing straight pipes. However, in practical applications, pipeline systems require matching fittings, such as elbows for changing the pipe's direction. Due to the large diameter of large-diameter polyethylene pipes, producing these elbow fittings becomes exceptionally difficult. Continuing to use steel fittings would not only increase costs but also diminish the many advantages inherent in polyethylene pipes themselves. Summary of the Invention

[0003] The purpose of this invention is to provide a winding process and equipment for manufacturing large-diameter polyethylene elbows, which can spirally wind polyethylene strips around the outer circumference of an inner mold to manufacture polyethylene elbow fittings, thus solving the problems in the prior art.

[0004] The technical solution adopted by this invention to solve its technical problem is: a winding production equipment for large-diameter polyethylene elbows, including a worktable, a rotating table that can rotate horizontally and a lifting table that can move vertically, wherein the rotating table is provided with an inner mold mounting frame, an inner mold mounting seat that can move along the length direction is installed on the inner mold mounting frame, and an inner mold that can rotate is hinged on the inner mold mounting seat. The rotation axis of the inner mold on the inner mold mounting seat is arranged perpendicular to the rotation axis of the rotating table. An extruder that can adjust the horizontal position is installed on the lifting table, wherein the central axis of the inner mold at the winding strip position is always coaxial with the rotation axis of the rotating table, and the polyethylene strip processed by the extruder can be spirally wound around the outer periphery of the inner mold. A slewing bearing is installed between the rotary table and the worktable. A first motor is installed on the rotary table, and a gear meshing with the external gear ring of the slewing bearing is provided on the output shaft of the first motor. A travel guide rail and a second motor are installed on the inner mold mounting frame. A travel slider that cooperates with the travel guide rail is provided on the inner mold mounting seat. A travel lead screw is provided on the output shaft of the second motor, and a travel nut that cooperates with the travel lead screw is installed on the inner mold mounting seat. A deflection shaft is installed between the inner mold and the inner mold mounting seat. A third motor is provided on one side of the inner mold mounting seat, and the output shaft of the third motor is connected to the deflection shaft. The deflection shaft is arranged perpendicular to the rotation axis of the slewing bearing. When the first motor is started, it can drive the inner mold to rotate vertically. When the second motor is started, it can drive the inner mold to move along the length direction of the inner mold mounting frame. When the third motor is started, it can drive the inner mold to rotate and adjust relative to the inner mold mounting seat. A top plate is installed on the workbench, and a lifting platform is located between the workbench and the top plate. A vertically arranged guide column is installed between the workbench and the top plate. A guide sleeve that cooperates with the guide column is installed on the lifting platform. A vertically arranged lifting screw is also installed between the workbench and the top plate. A fourth motor is provided on the lifting platform, and a lifting nut that cooperates with the lifting screw is installed on the output shaft of the fourth motor. The inner mold includes several interconnected unit molds. Each unit mold includes two sets of semi-circular templates that can be rotated and opened. One end of the two sets of semi-circular templates is connected by a hinge, and the other end of the two sets of semi-circular templates has parallel and matching bevels. The semi-circular template is made of trapezoidal plate bent into a semi-circle shape. A vertical rod is installed on the hinge. A mold core is installed at the end of the vertical rod away from the hinge. The mold core is arranged perpendicular to the vertical rod. The mold cores of all unit molds are connected as one piece. A parallelogram bracket that can telescopically move is installed between the mold core and the two sets of semi-circular templates. When the parallelogram bracket telescopically moves, it can drive the two sets of semi-circular templates to contract or open. When the two sets of semi-circular templates in the unit mold are in the open state, the bevels on each semi-circular template are separated from each other, and the end edges of the semi-circular templates in adjacent unit molds are aligned. When the two sets of semi-circular templates in the unit mold are in the contracted state, the two sets of semi-circular templates with bevels overlap at one end.A base frame is installed on the lifting platform, a longitudinal moving frame is installed on the base frame, and a transverse moving frame is installed on the longitudinal moving frame. The extruder is installed on the transverse moving frame. The base frame is equipped with a longitudinal moving slide rail and a fifth motor. The longitudinal moving frame is equipped with a longitudinal moving slider that cooperates with the longitudinal moving slide rail. A longitudinal moving screw is installed on the output shaft of the fifth motor. A longitudinal moving nut that cooperates with the longitudinal moving screw is installed on the longitudinal moving frame. A transverse moving slide rail and a sixth motor are installed on the longitudinal moving frame. A transverse moving slider that cooperates with the transverse moving slide rail is installed on the transverse moving frame. A transverse moving screw is installed on the output shaft of the sixth motor. A transverse moving nut that cooperates with the transverse moving screw is installed on the transverse moving frame. When the fifth motor is started, it can drive the extruder to move longitudinally relative to the lifting platform. When the sixth motor is started, it can drive the extruder to move laterally relative to the lifting platform. The parallelogram support includes two sets of first connecting rods and two sets of second connecting rods hinged together. One end of each of the first connecting rods is mounted on the mold core via a sleeve, and the other end of each first connecting rod is hinged to the end of a second connecting rod. The end of the second connecting rod furthest from the first connecting rod is mounted on the inner side of the semi-circular template via a hinged seat. A slider slot is mounted on the mold core, and an adjustable slider capable of vertical lifting is installed within the slider slot. Both sets of second connecting rods are hinged to the adjustable slider. When the adjustable slider moves along the slider slot, it can cause the parallelogram support to extend or retract, allowing the two sets of semi-circular templates to contract or expand. A seventh motor is mounted on the slider slot, and an adjusting screw is mounted on the output shaft of the seventh motor. An adjusting nut that cooperates with the adjusting screw is mounted on the adjusting slider. When the seventh motor is started, it can drive the adjusting slider to move along the slider slot. The adjusting slider is equipped with a limiting shaft, which is arranged parallel to the mold core. Both sets of second connecting rods are provided with insertion holes that cooperate with the limiting shaft. A spacer is installed on the limiting shaft, and the spacer is located between the two sets of second connecting rods.A winding process for a large-diameter polyethylene elbow includes the following steps: ① According to the actual shape of the elbow fitting to be processed, assemble each unit mold into a knotted inner mold, where each unit mold is a knot of the inner mold, and install the inner mold onto the inner mold mounting base; ② After the inner mold is installed in step ①, adjust the deflection angle between the inner mold and the inner mold mounting base, and the relative position of the inner mold on the inner mold mounting frame, so that the central axis of the unit mold at the position where the strip will be wound is coaxial with the rotation axis of the rotary table; ③ After the position adjustment of the inner mold in step ② is completed, adjust the relative position of the extruder on the lifting platform and the height of the lifting platform, so that the discharge port of the extruder is adapted to the inner mold where the strip will be wound; ④ After the position adjustment of the extruder in step ③ is completed... After completion, the extruder is started to extrude the polyethylene sheet onto the inner mold. At the same time, the rotary table drives the inner mold to rotate vertically, and the lifting table drives the extruder to move vertically, spirally winding the polyethylene sheet onto the inner mold at the unit mold position; ⑤ After the polyethylene sheet at the unit mold position in step ④ is spirally wound and the joint is compacted, the deflection angle of the inner mold at the next unit mold position and its relative position on the inner mold mounting frame are adjusted so that the central axis of the inner mold at the next unit mold position is coaxial with the rotation axis of the rotary table; ⑥ Repeat steps ③-⑤ until the winding of the entire inner mold is completed; ⑦ After the elbow fitting is made in step ⑥, the inner mold activates the parallelogram support of each unit mold inside, so that each section of mold is detached from the inner wall of the polyethylene elbow, and finally the finished polyethylene elbow is removed from the inner mold.

[0005] The positive effects of this invention are as follows: The winding and manufacturing equipment for large-diameter polyethylene elbows described herein includes a horizontally rotatable rotary table and a vertically movable lifting table mounted on a workbench. An inner mold with adjustable deflection angle and horizontal position is mounted on the rotary table, while an extruder capable of multi-dimensional movement is mounted on the lifting table. By adjusting the vertical lifting of the extruder and the adaptation of the inner mold to its rotation, precise spiral winding of polyethylene sheet and strip onto the inner mold can be achieved. The process steps in the winding and manufacturing of large-diameter polyethylene elbows ensure uniform wall thickness and a compact structure in all parts of the elbow fitting, greatly improving product quality and performance, and reducing quality problems such as leakage and insufficient strength that may occur due to inaccurate molding, thus meeting the high-quality requirements of large-diameter polyethylene pipeline systems for elbow fittings. This invention successfully solves the production problem of large-diameter polyethylene elbow fittings, eliminating the need to rely on expensive steel fittings. Compared to steel pipe fittings, polyethylene elbow fittings not only significantly reduce costs, but also fully leverage the inherent advantages of polyethylene pipes, such as good flexibility, strong corrosion resistance, bendability, and wear resistance. This allows the entire polyethylene piping system to achieve a better balance between performance and cost, enhancing its competitiveness in the market and providing strong support for the widespread application of polyethylene pipes in large-diameter applications. Attached Figure Description

[0006] Figure 1 This is a three-dimensional structural schematic diagram of the present invention; Figure 2 This is the front view of the present invention; Figure 3 yes Figure 2 Side view; Figure 4 yes Figure 2 Top view; Figure 5 yes Figure 4 A partial view of the sectional view along the AA direction; Figure 6 yes Figure 3 A partial view of the BB-direction sectional view; Figure 7 This is a schematic diagram showing the horizontal and vertical movement frames installed at the bottom of the extruder; Figure 8 yes Figure 7 An enlarged view of the sectional view along the CC direction; Figure 9 yes Figure 7 An enlarged view of the sectional view along the DD direction; Figure 10 This is a schematic diagram showing the state of the polyethylene sheet / strip wound onto the inner mold of the next node in this invention; Figure 11 This is a three-dimensional structural diagram of the inner mold; Figure 12 This is the front view of the inner mold; Figure 13 yes Figure 12 The left view; Figure 14 This is a structural schematic diagram of a unit mold; Figure 15 This is a schematic diagram of the structure of a set of semi-circular templates; Figure 16 This is a schematic diagram of the parallelogram support structure; Figure 17 yes Figure 16 Side view of the middle structure; Figure 18 yes Figure 16 An enlarged view of the EE-directed sectional view; Figure 19 This is a schematic diagram showing the state of two sets of semi-circular templates rotating and contracting. Detailed Implementation

[0007] The present invention provides a winding and manufacturing equipment for large-diameter polyethylene elbows, such as... Figure 1-4 As shown, the system includes a worktable 19, on which a horizontally rotatable rotary table 20 and a vertically movable lifting table 21 are mounted. The rotary table 20 has an inner mold mounting bracket 22, on which an inner mold mounting seat 23, movable along its length, is mounted. A rotatable inner mold 24 is hinged to the inner mold mounting seat 23. The rotation axis of the inner mold 24 on the inner mold mounting seat 23 is perpendicular to the rotation axis of the rotary table 20. By using the inner mold mounting bracket 22 and the inner mold mounting seat 23, the relative position and relative tilt angle of the inner mold 24 on the rotary table 20 can be adjusted.

[0008] An extruder 25 with adjustable horizontal position is installed on the lifting platform 21. The central axis of the inner mold 24 at the position where the strip is wound is always coaxial with the rotation axis of the rotary table 20. When the vertical movement of the lifting platform 21 causes the rotary table 20 to drive the inner mold 24 to rotate, the polyethylene strip processed by the extruder 25 can be spirally wound around the outer periphery of the inner mold 24.

[0009] The inner mold 24 serves as the forming mold inside the elbow fitting. To facilitate the final demolding of the elbow fitting, the inner mold 24 can be made into a segmented type, meaning that multiple unit molds are gradually bent to form the inner mold 24, which is uniformly connected by the mold core 2. Using the operation of the mold core 2, each segment of the inner mold 24 can be adjusted to open and close independently. The inner mold 24 can rotate around a vertical axis on the rotary table 20, and its vertical angle can also be adjusted. The extruder 25 extrudes polyethylene sheet strips, which spirally wind around the inner mold 24 using the rotation of the inner mold 24 and the up-and-down movement of the extruder 25, compacting the spiral joints. After one segment is wound, the inner mold 24 adjusts its tilt height to make the next segment vertical, continuing the spiral winding until the entire inner mold 24 is wound, forming the polyethylene elbow fitting. After the elbow fitting is made, the mold core 2 activates the internal shrinkage device of each steel mold segment, causing each steel mold segment to detach from the inner wall of the polyethylene elbow, and then the finished polyethylene elbow is removed.

[0010] The rotation of the rotary table 20 relative to the worktable 19 and the rotation of the inner mold 24 relative to the inner mold mounting base 23 can be driven by existing rotary motors or hydraulic motors. The movement of the inner mold mounting base 23 relative to the inner mold mounting frame 22 and the vertical lifting of the lifting platform 21 can be driven by existing drive motors or electric push rods. The coordinated operation of each component is achieved through existing position sensors, detectors and control systems.

[0011] When using a large-diameter polyethylene elbow winding production equipment to manufacture elbows, first adjust the rotation angle of the rotary table 20 and the position of the inner mold mounting base 23 on the inner mold mounting frame 22. Then adjust the tilt angle of the inner mold 24 relative to the inner mold mounting base 23 so that the central axis of the inner mold 24 at the winding strip position is aligned with the rotation axis of the rotary table 20. Finally, adjust the height of the lifting platform 21 so that the extruder 25 moves to the position on the inner mold 24 where the strip is to be wound. The extruder 25 extrudes the polyethylene strip, and the rotary table 20 drives the inner mold 24 to rotate. While the strip is winding, the lifting platform 21 drives the extruder 25 to move vertically, realizing the spiral winding of the polyethylene strip on the inner mold 24.

[0012] Furthermore, in order to achieve precise movement and control of the aforementioned components, such as Figure 5As shown, a slewing bearing 26 is installed between the rotary table 20 and the worktable 19. A first motor 27 is installed on the rotary table 20. The output shaft of the first motor 27 is provided with a gear 28 that meshes with the external gear ring of the slewing bearing 26. When the first motor 27 is started, it can drive the rotary table 20 to rotate.

[0013] The inner mold mounting frame 22 is equipped with a travel guide rail 29 and a second motor 30. The inner mold mounting base 23 is provided with a travel slider 31 that cooperates with the travel guide rail 29. The output shaft of the second motor 30 is provided with a travel lead screw 32, and the inner mold mounting base 23 is equipped with a travel nut 33 that cooperates with the travel lead screw 32. When the second motor 30 is started, it can drive the inner mold mounting base 23 to move on the inner mold mounting frame 22. A deflection shaft 34 is installed between the inner mold 24 and the inner mold mounting base 23. A third motor 35 is provided on one side of the inner mold mounting base 23. The output shaft of the third motor 35 is connected to the deflection shaft 34. The deflection shaft 34 is arranged perpendicular to the rotation axis of the slewing bearing 26. When the third motor 35 is started, it can drive the inner mold 24 to rotate and adjust relative to the inner mold mounting base 23. When the third motor 35 drives the deflection shaft 34 to rotate slightly, the inner mold 24 deflects and stops rotating at a certain angle. The inner mold 24 then ensures that a certain nodule unit mold is in a vertical position. Then, the rotary table 20 is operated to rotate around the vertical axis to spirally wind polyethylene sheet into this nodule unit mold.

[0014] A top plate 36 is installed on the workbench 19, and a lifting platform 21 is located between the workbench 19 and the top plate 36. Vertically arranged guide columns 37 are installed between the workbench 19 and the top plate 36, and guide sleeves 38 that mate with the guide columns 37 are installed on the lifting platform 21. Figure 6 As shown, a vertically arranged lifting screw 39 is installed between the worktable 19 and the top plate 36. A fourth motor 40 is provided on the lifting platform 21. A lifting screw nut 41 that cooperates with the lifting screw 39 is installed on the output shaft of the fourth motor 40. When the fourth motor 40 is started, it can drive the lifting platform 21 to move vertically up and down along the guide column 37.

[0015] In order to adjust the relative position of the extruder 25 on the lifting platform 21, such as Figure 7-9 As shown, a base frame 42 is mounted on the lifting platform 21, a longitudinal moving frame 43 is mounted on the base frame 42, and a transverse moving frame 44 is mounted on the longitudinal moving frame 43. The extruder 25 is mounted on the transverse moving frame 44. The base frame 42 is equipped with a longitudinal moving slide rail 45 and a fifth motor 46. The longitudinal moving frame 43 is equipped with a longitudinal moving slider 47 that cooperates with the longitudinal moving slide rail 45. A longitudinal moving lead screw 48 is mounted on the output shaft of the fifth motor 46, and a longitudinal moving nut 49 that cooperates with the longitudinal moving lead screw 48 is mounted on the longitudinal moving frame 43. When the fifth motor 46 is started, it can drive the extruder 25 to move longitudinally relative to the lifting platform 21.

[0016] A transverse slide rail 50 and a sixth motor 51 are installed on the longitudinal frame 43. A transverse slider 52 that cooperates with the transverse slide rail 50 is provided on the transverse frame 44. A transverse lead screw 53 is installed on the output shaft of the sixth motor 51. A transverse lead screw nut 54 that cooperates with the transverse lead screw 53 is provided on the transverse frame 44. When the sixth motor 51 is started, it can drive the extruder 25 to move laterally relative to the lifting platform 21.

[0017] The aforementioned structure allows the extruder 25 to perform two-dimensional motion adjustments on the horizontal plane of the lifting platform 21, ensuring that the strip produced by the extruder 25 is compatible with the position of the inner die 24. Simultaneously, the lifting platform 21 supports the extruder 25, moving it up and down to facilitate the spiral winding of the extruded strip onto the inner die 24. By adjusting the relative position of the inner die mounting base 23 on the inner die mounting frame 22, the vertical rotation axis of the rotary table 20 is always coaxially aligned with the section to be wound on the inner die 24, ensuring precise spiral winding of the strip. By adjusting the deflection angle of the inner die 24 on the inner die mounting base 23, each section's unit die can complete the winding of the polyethylene sheet at a vertical angle. The use of multiple motors in the equipment, such as the first motor 27 driving the vertical rotation of the inner die 24, the second motor 30 driving the horizontal movement of the inner die 24, and the third motor 35 adjusting the deflection angle of the inner die 24, along with the automatic height adjustment mechanism of the extruder 25, achieves automated control of the production process. Operators can adjust the inner mold and wind the polyethylene strip by controlling the motor to start and stop and setting parameters, reducing manual intervention, which not only improves production efficiency and shortens the production cycle, but also reduces errors and labor intensity caused by manual operation.

[0018] The connection methods of the various components in the above-mentioned equipment are reasonable. For example, the setting of components such as the slewing bearing 26, the traveling guide rail 29, and the guide column 37 provides a solid guarantee for the stable operation of the equipment. At the same time, the use of transmission mechanisms such as lead screws and lead nuts has the characteristics of high transmission accuracy and good stability, reducing vibration and wear during equipment operation, extending the service life of the equipment, and reducing maintenance costs and downtime. In the long run, this saves enterprises a lot of production and operating costs.

[0019] Furthermore, such as Figure 11-15 As shown, the inner mold 24 includes several connected unit molds. By adjusting the number and size of each unit mold, as well as parameters such as the tilt angle, this inner mold can flexibly produce large-diameter polyethylene elbows with different diameters and different bending angles to meet the actual needs of different engineering projects.

[0020] Each unit mold includes two sets of semi-circular templates 1 that can be rotated and opened / closed. One end of the two sets of semi-circular templates 1 is connected by a hinge 3, and the other end of the two sets of semi-circular templates 1 is provided with parallel and matching inclined edges 18. The semi-circular templates 1 are bent into a semi-circular shape from trapezoidal plates. The semi-circular templates 1 can rotate and open / close along the hinge 3. When the semi-circular templates 1 are open, they serve as internal supports for the elbow fitting to facilitate the spiral winding of the outer polyethylene strip. When the semi-circular templates 1 are closed, they detach from the inner circumferential wall of the formed elbow fitting, thus completing the demolding operation of the inner mold.

[0021] To enable the rotation and opening of the two sets of semi-circular templates 1, a vertical rod 7 is installed on the hinge 3. A mold core 2 is installed at the end of the vertical rod 7 away from the hinge 3. The mold core 2 is arranged perpendicular to the vertical rod 7, and the mold cores 2 of all unit molds are connected as one piece. A telescopic parallelogram bracket 5 is installed between the mold core 2 and the two sets of semi-circular templates 1. When the parallelogram bracket 5 telescopically moves, it can drive the two sets of semi-circular templates 1 to contract or open.

[0022] When the two sets of semicircular templates 1 in the unit mold are in the open state, the inclined edges 18 on each semicircular template 1 separate from each other, increasing the diameter of the unit mold. The outer circumference of the two sets of semicircular templates 1 can form a complete circle, facilitating the subsequent winding of polyethylene strip and the forming of the elbow. The end edges of the semicircular templates 1 in adjacent unit molds are aligned. When the two sets of semicircular templates 1 in the unit mold are in the contracted state, one end of the two sets of semicircular templates 1 with inclined edges 18 overlaps, reducing the diameter of the unit mold and facilitating the demolding of the formed elbow. The reasonable design and connection method of components such as the parallelogram bracket 5, hinge 3, and upright 7 provide stable structural support for the mold. During the winding of polyethylene strip and the forming of the elbow, the mold can withstand a certain amount of external force without deformation, ensuring that the shape and size of the elbow remain stable, thereby guaranteeing the structural performance and quality reliability of the product.

[0023] Furthermore, such as Figure 16-18 As shown, the parallelogram support 5 includes two sets of first connecting rods 8 and two sets of second connecting rods 9 that are hinged to each other. One end of each set of first connecting rods 8 is mounted on the mold core 2 through a sleeve 10, and the first connecting rod 8 can rotate relative to the mold core 2. The other end of the first connecting rod 8 is hinged to the end of the second connecting rod 9. The end of the second connecting rod 9 away from the first connecting rod 8 is mounted on the inner side of the semi-circular template 1 through a hinge seat 11, and the two sets of second connecting rods 9 are arranged in a crisscross pattern.

[0024] A slider groove frame 4 is installed on the mold core 2. An adjustable slider 6 that can be vertically raised and lowered is installed inside the slider groove frame 4. Both sets of second connecting rods 9 are hinged to the adjustable slider 6. When the adjustable slider 6 moves, its relative position with the second connecting rod 9 remains unchanged. When the adjustable slider 6 moves along the slider groove frame 4, it can drive the parallelogram bracket 5 to extend and retract, causing the two sets of semi-circular templates 1 to contract or open.

[0025] When the adjusting slider 6 moves downward relative to the slider slot frame 4, it moves closer to the mold core 2, the included angle between the two sets of second connecting rods 9 increases, the two hinge seats 11 move relative to each other, and the semi-circular template 1 rotates and opens, serving as an internal support for the production of elbow pipe fittings. When the adjusting slider 6 moves upward relative to the slider slot frame 4, it moves away from the mold core 2, the included angle between the two sets of second connecting rods 9 decreases, the two hinge seats 11 move relative to each other and closer, and the semi-circular template 1 rotates and retracts, realizing the subsequent demolding operation. The movement of the adjusting slider 6 relative to the slider slot frame 4 can be achieved by hydraulic cylinder, pneumatic cylinder, or motor traction. To achieve the accuracy of the opening and closing angle of the semi-circular template 1 and ensure precise control of the moving distance of the adjusting slider 6, a seventh motor 12 is installed on the slider slot frame 4. An adjusting screw 13 is installed on the output shaft of the seventh motor 12, and an adjusting nut 14 that cooperates with the adjusting screw 13 is installed on the adjusting slider 6. When the seventh motor 12 is started, it can drive the adjusting slider 6 to move along the slider slot frame 4.

[0026] The installation of the aforementioned power unit makes the operation of the mold more automated and convenient. Operators only need to control the start and stop of the seventh motor 12 to realize the opening and closing of the mold, reducing the difficulty of operation and labor intensity, reducing the impact of human factors on the production process, and further improving the stability and efficiency of production.

[0027] Furthermore, to facilitate the hinged installation of the second connecting rod 9 on the adjusting slider 6, a limiting shaft 15 can be installed on the adjusting slider 6. The limiting shaft 15 is arranged parallel to the mold core 2. Both sets of second connecting rods 9 are provided with insertion holes 16 that mate with the limiting shaft 15. A spacer 17 is installed on the limiting shaft 15, and the spacer 17 is located between the two sets of second connecting rods 9. The two sets of second connecting rods 9 are arranged one in front of the other to avoid mutual interference during rotation, and also to facilitate the connection and installation of the connecting rods on the slider 6 and the mold core 2.

[0028] The inner mold 24 is designed with two sets of semi-circular templates 1 that can be rotated and opened, and is connected to the mold core 2 through a parallelogram bracket 5. The contraction or opening of the two sets of semi-circular templates 1 is achieved by adjusting the slider 6 on the slider slot frame 4. This structure makes the opening and closing operation of the mold simple and quick. After the elbow fitting is manufactured, the mold can be easily detached from the inner wall of the polyethylene elbow, and the finished product can be smoothly removed. This avoids the problem of demolding difficulties caused by the mold sticking to the finished product, improves production efficiency, and reduces damage to the finished product during demolding, ensuring the integrity of the finished product.

[0029] The design of the segmented unit mold allows for flexible assembly according to the actual shape of the elbow fittings to be processed, adapting to the production needs of large-diameter polyethylene elbow fittings with different specifications, bending angles, and radii of curvature. Whether it is a small-angle or large-angle elbow, precise manufacturing can be achieved by adjusting the mold assembly method, greatly expanding the production range of the equipment, improving its efficiency and adaptability, and reducing the cost of purchasing multiple sets of equipment for producing different specifications of products.

[0030] The winding process for large-diameter polyethylene elbows includes the following steps: ① According to the actual shape of the elbow fitting to be processed, assemble each unit mold into a knotted inner mold 24, where each unit mold is a knot of the inner mold 24, and install the inner mold 24 onto the inner mold mounting base 23; ② After the inner mold 24 is installed in step ①, adjust the deflection angle between the inner mold 24 and the inner mold mounting base 23, and the relative position of the inner mold 24 on the inner mold mounting frame 22, so that the central axis of the unit mold at the position where the strip will be wound on the inner mold 24 is coaxial with the rotation axis of the rotary table 20; ③ After the position of the inner mold 24 is adjusted in step ②, adjust the relative position of the extruder 25 on the lifting platform 21 and the height of the lifting platform 21, so that the discharge port of the extruder 25 is compatible with the inner mold 24 where the strip will be wound; ④ After the position of the extruder 25 is adjusted in step ③, adjust the relative position of the extruder 25 on the lifting platform 21 and the height of the lifting platform 21, so that the discharge port of the extruder 25 is compatible with the inner mold 24 where the strip will be wound; After the section is completed, the extruder 25 starts to extrude the polyethylene sheet onto the inner mold 24. At the same time, the rotary table 20 drives the inner mold 24 to rotate vertically, and the lifting table 21 drives the extruder 25 to move vertically, spirally winding the polyethylene sheet onto the inner mold 24 at the unit mold position; ⑤ After the polyethylene sheet at the unit mold position in step ④ is spirally wound and the joint is compacted, adjust the deflection angle of the inner mold 24 at the next unit mold position and its relative position on the inner mold mounting bracket 22, so that the central axis of the inner mold 24 at the next unit mold position is coaxial with the rotation axis of the rotary table 20; ⑥ Repeat steps ③-⑤ until the winding of the entire inner mold 24 is completed; ⑦ After the elbow fitting is made in step ⑥, the inner mold 24 starts the parallelogram bracket 5 of each unit mold inside, so that each section of mold is separated from the inner wall of the polyethylene elbow, and finally the finished polyethylene elbow is removed from the inner mold 24.

[0031] The winding process has clearly defined steps, from mold assembly and positioning to polyethylene sheet and strip extrusion and winding, and finally to finished product demolding. Each step has detailed operating instructions and a sequential arrangement. This clear process allows operators to quickly master the production essentials, reducing the difficulty of technical training. Even non-professionals can operate the equipment after simple training, further improving the feasibility and efficiency of production.

[0032] This invention successfully solves the production problem of large-diameter polyethylene elbow fittings, eliminating the need to rely on costly steel fittings. Compared to steel fittings, polyethylene elbow fittings not only significantly reduce costs but also fully leverage the inherent advantages of polyethylene pipes, such as good flexibility, strong corrosion resistance, bendability, and wear resistance. This results in a better balance between performance and cost for the entire polyethylene piping system, enhancing its market competitiveness and providing strong support for the widespread application of polyethylene pipes in large-diameter applications.

[0033] The technical solutions of this invention are not limited to the embodiments described herein. All technical contents not described in detail herein are well-known technologies.

Claims

1. A winding and manufacturing equipment for large-diameter polyethylene elbows, characterized in that: The device includes a worktable (19), a horizontally rotatable rotary table (20) and a vertically movable lifting platform (21) mounted on the worktable (19). The rotary table (20) is provided with an inner mold mounting frame (22), and the inner mold mounting frame (22) is provided with an inner mold mounting seat (23) that can move along the length direction. The inner mold mounting seat (23) is hinged to a rotatable inner mold (24). The rotation axis of the inner mold (24) on the inner mold mounting seat (23) is arranged perpendicular to the rotation axis of the rotary table (20). An extruder (25) with adjustable horizontal position is mounted on the lifting platform (21). The central axis of the inner mold (24) at the position where the strip is wound is always coaxial with the rotation axis of the rotary table (20). The polyethylene sheet and strip processed by the extruder (25) can be spirally wound around the outer periphery of the inner mold (24). A slewing bearing (26) is installed between the rotary table (20) and the worktable (19). A first motor (27) is installed on the rotary table (20). A gear (28) meshing with the external gear ring of the slewing bearing (26) is provided on the output shaft of the first motor (27). A travel guide rail (29) and a second motor (30) are installed on the inner mold mounting frame (22). A travel slider (31) cooperating with the travel guide rail (29) is provided on the inner mold mounting base (23). A travel screw (32) cooperating with the travel screw (32) is provided on the output shaft of the second motor (30). A travel screw is installed on the inner mold mounting base (23). The inner mold (24) and the inner mold mounting base (23) are connected by a deflection shaft (34). A third motor (35) is provided on one side of the inner mold mounting base (23). The output shaft of the third motor (35) is connected to the deflection shaft (34). The deflection shaft (34) is arranged perpendicular to the rotation axis of the slewing bearing (26). The first motor (27) can drive the inner mold (24) to rotate vertically when started. The second motor (30) can drive the inner mold (24) to move along the length of the inner mold mounting frame (22) when started. The third motor (35) can drive the inner mold (24) to rotate and adjust relative to the inner mold mounting base (23) when started. A top plate platform (36) is installed on the worktable (19). The lifting platform (21) is located at... Between the workbench (19) and the top plate (36), a vertically arranged guide column (37) is installed. A guide sleeve (38) that cooperates with the guide column (37) is installed on the lifting platform (21). A vertically arranged lifting screw (39) is also installed between the workbench (19) and the top plate (36). A fourth motor (40) is provided on the lifting platform (21). A lifting nut (41) that cooperates with the lifting screw (39) is installed on the output shaft of the fourth motor (40). The inner mold (24) includes several connected unit molds. Each unit mold includes two sets of semi-circular templates (1) that can be rotated and opened. One end of the two sets of semi-circular templates (1) is connected by a hinge (3).The other end of the two sets of semicircular templates (1) is provided with parallel and matching inclined sides (18). The semicircular template (1) is made of trapezoidal plate bent into a semicircle. A vertical rod (7) is installed on the hinge (3). A mold core (2) is installed at the end of the vertical rod (7) away from the hinge (3). The mold core (2) is arranged perpendicular to the vertical rod (7). The mold cores (2) of all unit molds are connected as one unit. A parallel quadrilateral that can be telescopically moved is installed between the mold core (2) and the two sets of semicircular templates (1). When the parallelogram support (5) moves telescopically, it can cause the two sets of semicircular templates (1) to contract or open. When the two sets of semicircular templates (1) in the unit mold are in the open state, the hypotenuses (18) on each semicircular template (1) are separated from each other, and the end edges of the semicircular templates (1) in adjacent unit molds are aligned. When the two sets of semicircular templates (1) in the unit mold are in the contracted state, one end of the two sets of semicircular templates (1) with hypotenuses (18) overlaps.

2. The winding and manufacturing equipment for large-diameter polyethylene elbows according to claim 1, characterized in that: The lifting platform (21) is equipped with a base frame (42), a longitudinal moving frame (43) is provided on the base frame (42), a transverse moving frame (44) is provided on the longitudinal moving frame (43), and an extruder (25) is installed on the transverse moving frame (44). The base frame (42) is equipped with a longitudinal moving slide rail (45) and a fifth motor (46). The longitudinal moving frame (43) is equipped with a longitudinal moving slider (47) that cooperates with the longitudinal moving slide rail (45). The output shaft of the fifth motor (46) is equipped with a longitudinal moving screw (48), and the longitudinal moving frame (43) is equipped with a longitudinal moving screw nut that cooperates with the longitudinal moving screw (48). 49) A transverse slide rail (50) and a sixth motor (51) are installed on the longitudinal frame (43). A transverse slider (52) that cooperates with the transverse slide rail (50) is provided on the transverse frame (44). A transverse lead screw (53) is installed on the output shaft of the sixth motor (51). A transverse lead screw nut (54) that cooperates with the transverse lead screw (53) is provided on the transverse frame (44). When the fifth motor (46) is started, it can drive the extruder (25) to move longitudinally relative to the lifting platform (21). When the sixth motor (51) is started, it can drive the extruder (25) to move laterally relative to the lifting platform (21).

3. The winding and manufacturing equipment for large-diameter polyethylene elbows according to claim 1, characterized in that: The parallelogram support (5) includes two sets of first connecting rods (8) and two sets of second connecting rods (9) that are hinged to each other. One end of each set of first connecting rods (8) is mounted on the mold core (2) through a sleeve (10). The other end of the first connecting rod (8) is hinged to the end of the second connecting rod (9). The end of the second connecting rod (9) away from the first connecting rod (8) is mounted on the inner side of the semi-circular template (1) through a hinge seat (11). A slider groove frame (4) is installed on the mold core (2). An adjustable slider (6) that can be vertically raised and lowered is installed in the slider groove frame (4). Both sets of second connecting rods (9) are hinged to the adjustable slider (6). When the adjustable slider (6) moves along the slider groove frame (4), it can drive the parallelogram support (5) to extend and retract, causing the two sets of semi-circular templates (1) to contract or open.

4. The winding and manufacturing equipment for large-diameter polyethylene elbows according to claim 3, characterized in that: The seventh motor (12) is installed on the slider slot frame (4). An adjusting screw (13) is installed on the output shaft of the seventh motor (12). An adjusting nut (14) that cooperates with the adjusting screw (13) is installed on the adjusting slider (6). When the seventh motor (12) is started, it can drive the adjusting slider (6) to move along the slider slot frame (4).

5. The winding and manufacturing equipment for large-diameter polyethylene elbows according to claim 3, characterized in that: The adjusting slider (6) is equipped with a limiting shaft (15), which is arranged parallel to the mold core (2). Both sets of second connecting rods (9) are provided with insertion holes (16) that cooperate with the limiting shaft (15). A spacer (17) is installed on the limiting shaft (15), and the spacer (17) is located between the two sets of second connecting rods (9).

6. A winding process for manufacturing a large-diameter polyethylene elbow using the winding equipment described in claim 1, characterized in that: It includes the following steps: ①According to the actual shape of the elbow pipe fitting to be processed, assemble each unit mold into a joint-type inner mold (24). Each unit mold is a joint of the inner mold (24), and install the inner mold (24) onto the inner mold mounting base (23); ②After the inner mold (24) in step ① is installed, adjust the deflection angle between the inner mold (24) and the inner mold mounting base (23), and the relative position of the inner mold (24) on the inner mold mounting frame (22) so that the central axis of the unit mold at the position where the strip is to be wound on the inner mold (24) is arranged coaxially with the rotation axis of the rotary table (20); ③ After the position adjustment of the inner mold (24) in step ② is completed, adjust the relative position of the extruder (25) on the lifting platform (21) and the height position of the lifting platform (21) so that the discharge port of the extruder (25) is compatible with the inner mold (24) that will be wound around the strip. ④ After the position adjustment of the extruder (25) in step ③ is completed, the extruder (25) starts to extrude the polyethylene sheet onto the inner mold (24). At the same time, the rotary table (20) drives the inner mold (24) to rotate vertically, and the lifting table (21) drives the extruder (25) to move vertically, so that the polyethylene sheet is spirally wound onto the inner mold (24) at the unit mold position. ⑤ After the polyethylene strip at the unit mold position in step ④ is wound and the joint is compacted, adjust the deflection angle of the inner mold (24) at the next unit mold position and its relative position on the inner mold mounting frame (22) so that the central axis of the inner mold (24) at the next unit mold position is coaxial with the rotation axis of the rotary table (20). ⑥ Repeat steps ③-⑤ until the entire inner mold (24) is wrapped; ⑦ After the elbow fittings in step ⑥ are made, the inner mold (24) activates the parallelogram brackets (5) of each unit mold inside, so that each mold section is separated from the inner wall of the polyethylene elbow, and finally the finished polyethylene elbow is removed from the inner mold (24).

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