Winding manufacturing process and equipment for large-diameter polyethylene elbow

Abstract

The invention discloses winding manufacturing equipment and process for a large-diameter polyethylene elbow. Efficient and accurate forming is achieved through an innovative structure. The equipment comprises a working table, a horizontal rotating table and a vertical lifting table are arranged on the working table, an inner mold mounting base capable of moving along an inner mold mounting frame is mounted on the rotating table, an inner mold capable of being deflected and adjusted is hinged to the rotating table, a deflection shaft is driven by a third motor to achieve angle adjustment, and the lifting table is provided with a multi-direction adjusting extruder to ensure that the lifting table is matched with the inner mold. The inner mold adopts a nodule type design and is formed by connecting a plurality of unit molds through mold cores, each unit comprises two groups of semicircular mold plates capable of being opened and closed, contraction or expansion is realized through linkage of a parallelogram bracket and an adjusting sliding block, and an opening and closing angle is controlled by a seventh motor. The technological process comprises the steps of inner mold assembling, position adjusting, extruding and winding, section-by-section adjusting and demolding and part taking. The production problem of large-diameter polyethylene elbows is solved, the cost is reduced, the efficiency and quality are improved, and application of polyethylene pipelines is promoted.

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. 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 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. 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 Assemble the unit molds into a knotted inner mold according to the actual shape of the elbow fitting to be processed, 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 inner 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, extruder... The machine starts and extrudes 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 nodule position. ⑤ After the polyethylene sheet at the nodule position in step ④ is spirally wound and the joint is compacted, adjust the deflection angle of the inner mold at the next nodule position and its relative position on the inner mold mounting frame so that the central axis of the inner mold at the next nodule position is coaxial with the rotation axis of the rotary table. Repeat steps ③-⑤ until the entire inner mold is wound. ⑥ After the elbow fitting is made in step ⑤, the inner mold activates the internal shrinkage device of each nodule inside, so that each section of the mold is detached from the inner wall of the polyethylene elbow. 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 results in a better balance between performance and cost for the entire polyethylene pipeline system, enhancing its market competitiveness and providing strong support for the widespread application of polyethylene pipes in large-diameter applications. Attached Figure Description

[0006] Figure 1This 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, 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 the unit molds into a knotted 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 inner mold 24 at the position where the strip will be wound is coaxial 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 adapted to the inner mold 24 where the strip will be wound; ④ After the position adjustment of the extruder 25 in step ③ is completed... The extruder 25 starts extruding 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 nodule position. ⑤ After the polyethylene sheet at the nodule position in step ④ is spirally wound and the joint is compacted, the deflection angle of the inner mold 24 at the next nodule position and its relative position on the inner mold mounting bracket 22 are adjusted so that the central axis of the inner mold 24 at the next nodule position is coaxial with the rotation axis of the rotary table 20. Steps ③-⑤ are repeated until the entire inner mold 24 is wound. ⑥ After the elbow fitting is made in step ⑤, the inner mold 24 activates the internal shrinkage device of each nodule inside, so that each section of the mold is separated from the inner wall of the polyethylene elbow. 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 apparatus for making large diameter polyethylene bends, characterized by: The utility model provides a kind of polyethylene spiral-wound plate production equipment, including workbench (19), rotatable rotary table (20) and vertical movable lifting platform (21) are installed on workbench (19), wherein rotary table (20) is equipped with inner mould mounting frame (22), inner mould mounting seat (23) that can move along length direction is installed on inner mould mounting frame (22), rotatable inner mould (24) is hingedly installed on inner mould mounting seat (23), the rotation axis of inner mould (24) on inner mould mounting seat (23) is perpendicular to the rotation axis of rotary table (20) Arrangement, extruder (25) that can adjust horizontal position is installed on lifting platform (21), wherein the central axis of the position of inner mould (24) where plate belt is wound is coaxial with the rotation axis of rotary table (20) at all times, and polyethylene plate belt processed by extruder (25) can be spirally wound on the outer periphery of inner mould (24).

2. The winding apparatus for a large-diameter polyethylene elbow according to claim 1, characterized by: Rotary table (20) and workbench (19) are equipped with slewing bearing (26) between, first motor (27) is installed on rotary table (20), gear (28) is equipped with with the outer gear ring of slewing bearing (26) on the output shaft of first motor (27), walking guide rail (29) and second motor (30) are installed on the inner mould mounting frame (22), walking sliding block (31) is equipped with with walking guide rail (29) on inner mould mounting seat (23), walking screw rod (32) is equipped with on the output shaft of second motor (30), walking screw nut (33) is installed on inner mould mounting seat (23) with walking screw rod (32) Cooperation, deflection shaft (34) is installed between inner mould (24) and inner mould mounting seat (23), third motor (35) is equipped with on the side of inner mould mounting seat (23), the output shaft of third motor (35) is connected with deflection shaft (34), wherein deflection shaft (34) is perpendicular to the rotation axis of slewing bearing (26) Arrangement, first motor (27) can drive inner mould (24) vertical rotation to start, second motor (30) can drive inner mould (24) to move along the length direction of inner mould mounting frame (22) to start, third motor (35) can drive inner mould (24) to rotate adjustment relative to inner mould mounting seat (23) to start.

3. The winding apparatus for large diameter polyethylene elbow according to claim 1, characterized in that: Top plate table (36) is installed on the workbench (19), and the lifting platform (21) is located between the workbench (19) and the top plate table (36), a vertical guide column (37) is installed between the workbench (19) and the top plate table (36), a guide sleeve (38) is installed on the lifting platform (21) and matched with the guide column (37), a vertical lifting screw rod (39) is also installed between the workbench (19) and the top plate table (36), a fourth motor (40) is provided on the lifting platform (21), and a lifting screw nut (41) matched with the lifting screw rod (39) is installed on the output shaft of the fourth motor (40).

4. The winding apparatus for large diameter polyethylene elbow according to claim 1, characterized in that: The lifting platform (21) is provided with a base frame (42), the base frame (42) is provided with a longitudinal moving frame (43), the longitudinal moving frame (43) is provided with a transverse moving frame (44), and the extruder (25) is installed on the transverse moving frame (44), wherein the base frame (42) is provided with a longitudinal moving slide rail (45) and a fifth motor (46), the longitudinal moving frame (43) is provided with a longitudinal moving slide block (47) matched with the longitudinal moving slide rail (45), a longitudinal moving screw (48) is installed on the output shaft of the fifth motor (46), the longitudinal moving frame (43) is provided with a longitudinal moving nut (49) matched with the longitudinal moving screw (48), the longitudinal moving frame (43) is provided with a transverse moving slide rail (50) and a sixth motor (51), the transverse moving frame (44) is provided with a transverse moving slide block (52) matched with the transverse moving slide rail (50), a transverse moving screw (53) is installed on the output shaft of the sixth motor (51), and the transverse moving frame (44) is provided with a transverse moving nut (54) matched with the transverse moving screw (53); the fifth motor (46) can drive the extruder (25) to move longitudinally relative to the lifting platform (21), and the sixth motor (51) can drive the extruder (25) to move transversely relative to the lifting platform (21).

5. The apparatus for winding a large-diameter polyethylene elbow according to claim 1, wherein: The inner mold (24) comprises a plurality of connected unit molds, each unit mold comprises two groups of half-round mold plates (1) capable of being opened and closed, one end of the two groups of half-round mold plates (1) is connected through a hinge (3), the other end of the two groups of half-round mold plates (1) is provided with parallel matching bevels (18), the half-round mold plate (1) is bent into a half-round shape from a trapezoidal plate, a vertical rod (7) is installed on the hinge (3), a mold core (2) is installed at one 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 into one body, a parallelogram support (5) capable of extending and retracting is installed between the mold core (2) and the two groups of half-round mold plates (1), the parallelogram support (5) can drive the two groups of half-round mold plates (1) to contract or expand when extending and retracting, when the two groups of half-round mold plates (1) in the unit mold are in the expanded state, the bevels (18) on the half-round mold plates (1) are separated from each other, the end edges of the half-round mold plates (1) in adjacent unit molds are aligned, and when the two groups of half-round mold plates (1) in the unit mold are in the contracted state, the two groups of half-round mold plates (1) with the bevels (18) at one end are matched and overlapped.

6. A winding apparatus for making large diameter polyethylene bends according to claim 5, characterized in that: The parallelogram support (5) comprises two groups of first connecting rods (8) and two groups of second connecting rods (9) which are connected with each other, one end of the two groups of first connecting rods (8) is installed on the mold core (2) through a sleeve (10), the other end of the first connecting rod (8) is hingedly connected with the end of the second connecting rod (9), the end of the second connecting rod (9) away from the first connecting rod (8) is installed on the inner side of the semicircular mold plate (1) through a hinge seat (11), a sliding block slot frame (4) is installed on the mold core (2), a vertical lifting adjusting sliding block (6) is installed in the sliding block slot frame (4), the two groups of second connecting rods (9) are hingedly installed on the adjusting sliding block (6), when the adjusting sliding block (6) moves along the sliding block slot frame (4), the parallelogram support (5) can be stretched and retracted to make the two groups of semicircular mold plates (1) contract or expand.

7. A winding apparatus for making large diameter polyethylene bends as claimed in claim 5, wherein: A seventh motor (12) is installed on the sliding block slot frame (4), an adjusting screw rod (13) is installed on the output shaft of the seventh motor (12), an adjusting screw nut (14) matched with the adjusting screw rod (13) is installed on the adjusting sliding block (6), when the seventh motor (12) is started, the adjusting sliding block (6) can be driven to move along the sliding block slot frame (4).

8. The winding apparatus for large diameter polyethylene elbow according to claim 5, characterized in that: A limiting shaft (15) is installed on the adjusting sliding block (6), the limiting shaft (15) is arranged in parallel with the mold core (2), the two groups of second connecting rods (9) are provided with insertion holes (16) matched with the limiting shaft (15), a spacer sleeve (17) is installed on the limiting shaft (15), and the spacer sleeve (17) is located between the two groups of second connecting rods (9).

9. A process for the fabrication of large diameter polyethylene bends by winding, characterized in that: The method comprises the following steps: ①According to the actual shape of the elbow pipe fitting to be processed, the unit molds are assembled into a nodular inner mold (24), and the inner mold (24) is installed on the inner mold mounting seat (23); ②After the inner mold (24) is installed in step ①, the deflection angle of the inner mold (24) and the inner mold mounting seat (23) and the relative position of the inner mold (24) on the inner mold mounting frame (22) are adjusted, so that the central axis of the position where the plate belt is about to be wound on the inner mold (24) is coaxially arranged with the rotating shaft of the rotating table (20); ③After the position of the inner mold (24) is adjusted in step ②, the relative position of the extruder (25) on the lifting table (21) and the height position of the lifting table (21) are adjusted, so that the discharge port of the extruder (25) is matched with the inner mold (24) where the plate belt is about to be wound; ④After the position of the extruder (25) is adjusted in step ③, the extruder (25) is started to extrude the polyethylene plate belt onto the inner mold (24), at the same time, the rotating table (20) drives the inner mold (24) to vertically rotate, and the lifting table (21) drives the extruder (25) to vertically move, so that the polyethylene plate belt is spirally wound on the inner mold (24) at the nodular position; ⑤After the polyethylene plate in the nodal position in step ④ is wound and the joint is compacted, the deflection angle of the inner mold (24) in the next nodal position and the relative position on the inner mold mounting frame (22) are adjusted, the central axis of the inner mold (24) in the next nodal position is coaxially arranged with the rotating axis of the rotating table (20), and steps ③-⑤ are repeated until the winding of the entire inner mold (24) is completed; ⑥After the elbow pipe is manufactured in step ⑤, the inner retraction device of each nodal position of the inner mold (24) is started, the mold in each nodal position is separated from the inner wall of the polyethylene elbow, and finally the polyethylene elbow product is taken off from the inner mold (24).

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