Device and process for forming PE (polyethylene) pipe with biaxial orientation

Abstract

The invention relates to the technical field of plastic pipe forming, in particular to a biaxial orientation PE pipe forming device and process, and the biaxial orientation PE pipe forming device comprises a first end body fixedly connected with one end of a middle body and a second end body arranged at the other end of the middle body; a breather pipe is fixedly arranged on the first end body in the axis direction of the first end body, the breather pipe is sleeved with a first sealing sleeve for supporting a pipe, the first sealing sleeve is made of a high-temperature-resistant elastic material, and an expansion cavity is formed by the inner ring side of the first sealing sleeve and the outer wall of the breather pipe; and a plurality of ventilation ports communicated with the expansion cavity are formed in the side wall of the ventilation pipe. The situation that hot air overflows is avoided, the extrusion force of the first sealing sleeve on the pipe is guaranteed, and the energy consumption is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of plastic pipe forming, and in particular to a PE pipe forming device and process with biaxial orientation. Background Art

[0002] At present, when preparing biaxially oriented plastic tubes, the tubes are axially stretched by a traction machine and radially expanded by expansion pieces such as cones. However, since the two steps are carried out separately, the preparation cycle is long and the production efficiency is low. At the same time, the introduction of expansion pieces such as cones will cause friction with the tube blank, affecting the appearance quality and mechanical properties of the final product.

[0003] Chinese patent announcement number CN112848245B discloses a biaxially oriented plastic tube forming mold, comprising: a first end body, a middle body, a second end body, a limit block, a fixed block and a vent pipe; the first end body, the middle body and the second end body are respectively provided with inner cavities along the axis, the first end body, the middle body and the second end body are sequentially detachably connected along the axis, and the inner cavities are sequentially connected, and the diameter of the inner cavity of the middle body is larger than the diameter of the inner cavity of the first end body and the second end body; one end of the limit block is detachably connected to an end of the first end body away from the middle body, and the other end of the limit block extends into the inner cavity of the first end body and has a gap with the inner side wall of the first end body; one end of the fixed block is connected to an end of the second end body away from the middle body, and the other end of the fixed block extends into the inner cavity of the second end body; the vent pipe passes through the fixed block and extends into the inner cavity, and a plug is provided at one end of the vent pipe located in the inner cavity and a plurality of vent holes are provided on the side wall of the vent pipe.

[0004] The above scheme combines the axial orientation process and the radial orientation process, and completes the forming of the biaxially oriented PE pipe through one device. However, when the PE pipe is axially oriented and stretched, the two ends of the PE pipe lack fixed clamping devices. Therefore, when the PE pipe is axially oriented, the pipe is prone to slippage. At the same time, when the pipe is radially oriented, the heated pipe is easily squeezed into the exhaust hole under the action of air pressure. After molding and separation, the exhaust hole is prone to be blocked. In addition, when the pipe is radially oriented, the radial direction of the pipe is expanded by inflation, but the gas filled into the inner ring side of the pipe is easy to overflow from the end of the pipe, resulting in a decrease in the expansion rate of the pipe. It will also cause uneven deformation during the radial orientation of the pipe, thereby affecting the performance of the biaxially oriented PE pipe after molding. Summary of the invention

[0005] In view of the above problems, a PE pipe forming device and process with biaxial orientation are provided. A first sealing sleeve is sleeved on the ventilation pipe and made of a high-temperature resistant elastic material. During the forming process, hot air is filled into the forming cavity through the heating unit, and at the same time, the ventilation pipe rushes the hot air into the expansion cavity through the vent, so that the inside and outside of the pipe are heated at the same time. As the hot air is continuously filled into the expansion cavity, the expansion cavity continuously expands and squeezes the inner ring side of the pipe, so that the diameter of the pipe gradually increases. During this process, the expansion cavity is always in a sealed state, and the hot air in the expansion cavity will not overflow into the forming cavity, thereby avoiding the overflow of hot air in the expansion cavity. This not only ensures the squeezing force of the first sealing sleeve on the pipe, but also reduces the energy consumption.

[0006] In order to solve the problems of the prior art, the present invention provides a PE pipe forming device with biaxial orientation, comprising a first end body fixedly connected to one end of a middle body and a second end body arranged on the other end of the middle body; a ventilation pipe is fixedly arranged on the first end body along the axial direction of the first end body, a first sealing sleeve for supporting the pipe is sleeved on the outside of the ventilation pipe, the first sealing sleeve is made of high-temperature resistant elastic material, the inner ring side of the first sealing sleeve and the outer wall of the ventilation pipe form an expansion cavity, and a plurality of ventilation ports connected to the expansion cavity are opened on the side wall of the ventilation pipe.

[0007] Preferably, a molding cavity is formed after the first end body, the middle body and the second end body are closed, and the molding device also includes a heating unit for heating the molding cavity, the heating unit includes an inflation port opened on the first end body and an air outlet opened on the second end body, the inflation port fills hot air into the molding cavity and discharges it from the air outlet.

[0008] Preferably, an air heater is provided on one side of the middle body, the air heater has an input end and an output end, the inflation port and the air outlet are respectively connected to the output end and the input end of the air heater, and a switch valve and a pressure relief valve are provided on the upper part of the air heater.

[0009] Preferably, ventilation racks are provided at both the inflation port and the air outlet, and blocking blocks are slidably provided on the ventilation racks along the thickness direction of the ventilation racks. When the two blocking blocks rise to the highest position, they can respectively block the inflation port and the air outlet.

[0010] Preferably, a translation column is arranged for horizontal movement in the ventilation pipe, and a plurality of racks parallel to the extension direction of the translation column are evenly arranged around the translation column. A plurality of gears meshing with the racks are rotatably arranged on one side of each rack along the extension direction of the rack, and the gears are rotatably arranged on the ventilation port. A fixed plate is fixedly arranged on the inner ring side wall of the first sealing sleeve, and a sliding block is arranged on the fixed plate for horizontal sliding, and a connecting rod is arranged between the sliding block and the gear, and the connecting rod is fixedly connected to the gear, and the connecting rod is hinged to the sliding block.

[0011] Preferably, a support shaft is horizontally arranged in the ventilation pipe, a translation column is slidably arranged on the support shaft, an annular ventilation groove is present between the translation column and the inner wall of the ventilation pipe, and an air pump is arranged at the end of the ventilation pipe.

[0012] Preferably, the middle body includes a first sliding sleeve and a second sliding sleeve, the first sliding sleeve is fixedly connected to the first end body, an extension ring is fixedly provided on one end of the first sliding sleeve, and a sleeve ring is fixedly provided on the end of the second sliding sleeve, the sleeve ring is sleeved on the periphery of the extension ring and slidably cooperates with the extension ring.

[0013] Preferably, an annular second sealing sleeve is provided on the inner ring side of the extension ring, two ends of the second sealing sleeve are respectively fixedly connected to the first sliding sleeve and the second sliding sleeve, and the second sealing sleeve is made of high temperature resistant elastic material.

[0014] Preferably, an annular groove is formed between the second sealing sleeve and the collar, the extension ring is slidably arranged in the annular groove, a valve body connected to the annular groove is arranged on the collar, and when the extension ring slides out of the annular groove, the valve body injects water into the annular groove.

[0015] The present invention also relates to a PE pipe forming process with biaxial orientation, using a PE pipe forming device with biaxial orientation, and the specific process is as follows: S1, placing the pipe on the ventilation pipe, and then closing the ends of the second end body and the middle body, so that the first end body, the middle body and the second end body form a molding cavity; S2, the heating unit starts and heats the pipe in the molding cavity, and hot air flows in the molding cavity; S3. The vent pipe inflates the expansion chamber through the vent port, and the first sealing sleeve squeezes the inner ring of the pipe, so that the pipe expands in the radial direction, and the middle body drives the pipe to extend in the axial direction in the horizontal direction.

[0016] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention arranges a first sealing sleeve on the ventilation pipe, and makes the first sealing sleeve made of high-temperature resistant elastic material. During molding, hot air is filled into the molding cavity through the heating unit, and at the same time, the ventilation pipe rushes the hot air into the expansion cavity through the vent, so that the inside and outside of the pipe are heated at the same time. As the hot air is continuously filled into the expansion cavity, the expansion cavity continuously expands and squeezes the inner ring side of the pipe, so that the diameter of the pipe gradually increases. During this process, the expansion cavity is always in a sealed state, and the hot air in the expansion cavity will not overflow into the molding cavity, thereby avoiding the overflow of hot air in the expansion cavity, which not only ensures the squeezing force of the first sealing sleeve on the pipe, but also reduces the energy consumption.

[0017] 2. By respectively arranging an inflation port and an air outlet on the first end body and the second end body, the inflation port fills hot air into the molding cavity, and the air outlet discharges the air in the molding cavity, so that the hot air flows in the molding cavity. At the same time, the ventilation pipe fills the expansion cavity with hot air, so that the pipe is heated on both sides, which accelerates the heating speed of the pipe. By arranging a pressure relief valve on the air heater, when the expansion cavity gradually expands under the inflation action of the ventilation pipe, the expansion cavity gradually expands, the molding cavity is gradually squeezed, and the volume in the molding cavity will become smaller and smaller. In this process, the squeezed air in the molding cavity is discharged through the pressure relief valve arranged on the air heater, which ensures that the pipe can be heated on both sides and can be normally radially oriented. At the same time, by arranging blocking blocks on the inflation port and the air outlet, it is avoided that the inflation port or the air outlet is blocked by the material of the pipe. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a three-dimensional schematic diagram of a PE pipe forming device with biaxial orientation according to the present invention.

[0019] Figure 2 It is a side view of a PE pipe forming device with biaxial orientation according to the present invention when an unprocessed pipe is placed in it.

[0020] Figure 3 The present invention is a PE pipe forming device with biaxial orientation Figure 2 Schematic cross-sectional view at AA in the middle.

[0021] Figure 4 It is a cutaway stereoscopic schematic diagram of a PE pipe forming device with biaxial orientation according to the present invention.

[0022] Figure 5 The present invention is a PE pipe forming device with biaxial orientation Figure 4 A local enlarged schematic diagram of point B in the middle.

[0023] Figure 6 The present invention is a PE pipe forming device with biaxial orientation Figure 4 A partial enlarged schematic diagram of point C in the middle.

[0024] Figure 7 It is a cutaway stereoscopic schematic diagram of a PE pipe forming device with biaxial orientation of the present invention when the pipe processing is completed.

[0025] Figure 8 The present invention is a PE pipe forming device with biaxial orientation Figure 7 A local enlarged schematic diagram of point D in the middle.

[0026] Fig. 9 The present invention is a PE pipe forming device with biaxial orientation Figure 7 A partial enlarged schematic diagram of point E in the middle.

[0027] Fig.10 The present invention is a PE pipe forming device with biaxial orientation Figure 7 A partial enlarged schematic diagram of point F in the middle.

[0028] Fig.11 It is a three-dimensional schematic diagram of a PE pipe forming device with biaxial orientation of the present invention after removing the second sliding sleeve and the heating unit.

[0029] The numbers in the figure are: 1. First end body; 11. Ventilation pipe; 111. Ventilation port; 12. First sealing sleeve; 13. Hydraulic clamp; 14. Translation column; 141. Rack; 15. Gear; 16. Connecting rod; 17. Fixed plate; 18. Sliding block; 19. Support shaft; 191. Air pump; 2. Middle body; 21. First sliding sleeve; 211. Extension ring; 22. Second sliding sleeve; 221. Ring; 23. Drive unit; 231. Linear drive; 232. Rangefinder; 24. Second sealing sleeve; 25. Valve body; 3. Second end body; 4. Pipe; 5. Heating unit; 51. Inflating port; 52. Air outlet; 53. Air heater; 54. Switch valve; 55. Pressure relief valve; 56. Ventilation rack; 57. Blocking block. DETAILED DESCRIPTION

[0030] In order to further understand the features, technical means, specific objectives and functions of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0031] Reference Figure 1-Figure 3 , Figure 7 and Fig.11 : A PE pipe forming device with biaxial orientation, comprising a first end body 1 fixedly connected to one end of a middle body 2 and a second end body 3 arranged on the other end of the middle body 2; a ventilation pipe 11 is fixedly arranged on the first end body 1 along the axial direction of the first end body 1, and a first sealing sleeve 12 supported by multiple pipes 4 is sleeved on the outside of the ventilation pipe 11, the first sealing sleeve 12 is made of high-temperature resistant elastic material, the inner ring side of the first sealing sleeve 12 and the outer wall of the ventilation pipe 11 form an expansion cavity, and a plurality of ventilation ports 111 connected to the expansion cavity are opened on the side wall of the ventilation pipe 11.

[0032] In the process of processing the biaxially oriented PE pipe 4, it is necessary to orient the pipe 4 in the radial direction and the axial direction so that the diameter of the pipe 4 becomes larger and the length becomes longer. The traditional molding method usually needs to be divided into two steps, including radial orientation and axial orientation. The pipe 4 needs to be heated during the orientation. If radial orientation is performed, the heated pipe 4 needs to be stretched along its radial direction so that the diameter of the pipe 4 gradually becomes larger; if axial orientation is performed, the heated pipe 4 needs to be stretched along its axial direction so that the length of the pipe 4 becomes longer. Therefore, it needs to be divided into two steps for processing, and the processing efficiency is low. In order to improve efficiency, a device combining radial orientation and axial orientation has been designed in the prior art. For example, Chinese patent announcement No. CN112848245B discloses a biaxially oriented plastic tube forming mold. The above patent comprises a detachable first end body 1, a middle body 2 and a second end body 3, which together form a forming cavity for forming a tube 4. The length of the middle body 2 in the horizontal direction can be extended. A vent pipe 11 for supporting the tube 4 is arranged on the first end body 1. When performing the forming operation, the tube 4 is placed on the vent pipe 11, and then the first end body 1, the middle body 2 and the second end body 3 are connected together, so that the forming cavity is shaped. Then, the ventilation pipe 11 starts to fill the inner ring side of the pipe 4 with high-temperature gas, so that the gas can heat the pipe 4, and at the same time, it can also increase the air pressure on the inner ring side of the pipe 4, so that the pipe 4 gradually expands, and at the same time, the middle body 2 that can be expanded and contracted in the horizontal direction axially orients the pipe 4, thereby completing the molding process of the biaxially oriented PE pipe 4. However, there is a problem in the above process, that is, there must be a gap between the inner ring of the pipe 4 and the outer wall of the ventilation pipe 11, which leads to air leakage during the inflation process, resulting in a large amount of heated gas escaping, which not only leads to a slow molding rate of the pipe 4, but also a large amount of leaked gas will lead to high energy consumption.

[0033] In order to avoid the above situation, the structure of the existing forming device is further optimized, so that the speed of the tube 4 during radial orientation forming is increased, and the heated air is prevented from constantly overflowing and dissipating, thereby reducing energy consumption. The specific structure and working steps of the forming device are as follows: The first end body 1 and the second end body 3 are both provided with hydraulic clamps 13 for clamping the ends of the pipes 4. The hydraulic clamps 13 are driven by hydraulic pressure. When the forming operation is performed, the pipe 4 is put in from the end of the middle body 2 so that the pipe 4 is sleeved on the ventilation pipe 11. Then the second end body 3 and the middle body 2 are closed. At this time, the first end body 1, the middle body 2 and the second end body 3 jointly form a forming cavity. The forming device also includes a heating unit 5 for heating the forming cavity. The heating unit 5 can fill the heated air into the forming cavity, so that the pipe 4 arranged on the ventilation pipe 11 can be heated by the hot air. Then the ventilation pipe 11 inflates the expansion cavity through the vent 111. In this way, the air pressure in the expansion cavity continues to increase, and the first sealing sleeve 12 inflates the pipe 4 under the action of the air pressure. The inner wall is extruded, so that the diameter of the pipe 4 gradually increases during the extrusion process. Since the middle body 2 can be stretched in the horizontal direction, and during the molding process, the two ends of the pipe 4 will be clamped by the hydraulic clamps 13 in the first end body 1 and the second end body 3 respectively. When the middle body 2 is stretched, the first end body 1 and the second end body 3 clamp the pipe 4 to stretch it, so that the pipe 4 can be oriented axially while being radially oriented, thereby improving the molding efficiency. In addition, since the present invention sets the first sealing sleeve 12 on the outside of the vent pipe 11, the expansion chamber formed by the inner ring side wall of the first sealing sleeve 12 and the vent pipe 11 is in a sealed state, avoiding leakage during the inflation of the expansion chamber, and avoiding a large amount of hot air from being lost due to leakage, thereby reducing energy consumption. It is worth noting that the air filled into the expansion chamber is also hot air, so that the pipe 4 can be molded faster. The first sealing sleeve 12 can be made of high-temperature resistant elastic materials such as fluororubber and thermoplastic vulcanized rubber.

[0034] By sleeved the first sealing sleeve 12 on the ventilation pipe 11, and making the first sealing sleeve 12 made of high temperature resistant elastic material, during molding, hot air is filled into the molding cavity through the heating unit 5, and at the same time, the ventilation pipe 11 rushes the hot air into the expansion cavity through the vent 111, so that the inside and outside of the tube 4 are heated at the same time, and as the hot air is continuously filled into the expansion cavity, the expansion cavity continuously expands and squeezes the inner ring side of the tube 4, so that the diameter of the tube 4 gradually increases. During this process, the expansion cavity is always in a sealed state, and the hot air in the expansion cavity will not overflow into the molding cavity, thereby avoiding the overflow of hot air in the expansion cavity, which not only ensures the squeezing force of the first sealing sleeve 12 on the tube 4, but also reduces the energy consumption.

[0035] Reference Figure 3 , Figure 4 and Figure 7: The first end body 1, the middle body 2 and the second end body 3 are closed to form a molding cavity. The molding device also includes a heating unit 5 for heating the molding cavity. The heating unit 5 includes an inflation port 51 opened on the first end body 1 and an air outlet 52 opened on the second end body 3. The inflation port 51 fills hot air into the molding cavity and discharges it from the air outlet 52.

[0036] In the prior art, when heating the tube 4, only one-side heating is used to heat the tube 4, that is, hot air is filled into one side of the inner ring of the tube 4 through the ventilation pipe 11, so that the hot air can heat the tube 4 and squeeze the tube 4 at the same time. However, the heating speed is slow and the deformation speed of the tube 4 is also slow. In order to avoid the above situation, an inflation port 51 and an air outlet 52 are respectively provided on the first end body 1 and the second end body 3, so that the inflation port 51 fills hot air into the molding cavity, and the air outlet 52 discharges the air in the molding cavity, so that the hot air flows in the molding cavity. At the same time, the ventilation pipe 11 fills the expansion cavity with hot air, so that the tube 4 is heated on both sides, thereby accelerating the heating speed of the tube 4.

[0037] Reference Figure 1 An air heater 53 is arranged on one side of the middle body 2. The air heater 53 has an input end and an output end. The inflation port 51 and the air outlet 52 are respectively connected to the output end and the input end of the air heater 53. A switch valve 54 and a pressure relief valve 55 are arranged on the upper part of the air heater 53.

[0038] During the molding process, the expansion cavity gradually expands under the inflation effect of the vent pipe 11, so that the expansion cavity gradually expands, the molding cavity is gradually squeezed, and the volume in the molding cavity becomes smaller and smaller. In this process, the squeezed air in the molding cavity is discharged through the pressure relief valve 55 provided on the air heater 53, and the switch valve 54 is in a closed state at this time, ensuring that the pipe 4 can be heated on both sides while ensuring that the pipe 4 can be normally oriented radially. When the molding is completed, the vent pipe 11 discharges the air in the reverse direction, and the switch valve 54 is opened at this time, and the outside air can flow into the air heater 53.

[0039] Reference Figure 8 : A ventilation frame 56 is provided at both the inflation port 51 and the air outlet 52, and a blocking block 57 is slidably provided on the ventilation frame 56 along the thickness direction of the ventilation frame 56. When the two blocking blocks 57 rise to the highest position, they can respectively block the inflation port 51 and the air outlet 52.

[0040] When the vent pipe 11 inflates the expansion chamber, the first sealing sleeve 12 squeezes the inner ring side wall of the tube 4 and gradually increases the diameter of the tube 4. Since the tube 4 is heated and softened, the blocking blocks 57 are provided at the inflation port 51 and the air outlet 52 to prevent part of the material of the tube 4 from being squeezed into the inflation port 51 and the air outlet 52 when the first sealing sleeve 12 radially orients the tube 4. When the formed tube 4 is subsequently taken out, the inflation port 51 and the air outlet 52 are easily blocked by the material. After the blocking blocks 57 are provided on the inflation port 51 and the air outlet 52, when the tube 4 expands to the inflation port 51 or the air outlet 52, the blocking blocks 57 will be pushed into the inflation port 51 or the air outlet 52 by the tube 4. The softened tube 4 cannot be squeezed into the inflation port 51 or the air outlet 52, thereby preventing the material of the tube 4 from blocking the inflation port 51 or the air outlet 52.

[0041] Reference Figure 5 , Figure 6 and Fig. 9 A translation column 14 is arranged to move horizontally in the ventilation pipe 11, and a plurality of racks 141 parallel to the extension direction of the translation column 14 are evenly arranged around the translation column 14. A plurality of gears 15 meshing with the racks 141 are rotatably arranged on one side of each rack 141 along the extension direction of the rack 141. The gears 15 are rotatably arranged on the ventilation port 111. A fixing plate 17 is fixedly arranged on the inner ring side wall of the first sealing sleeve 12, and a sliding block 18 is horizontally slidably arranged on the fixing plate 17. A connecting rod 16 is arranged between the sliding block 18 and the gear 15, and the connecting rod 16 is fixedly connected to the gear 15, and the connecting rod 16 is hinged to the sliding block 18.

[0042] When the vent pipe 11 inflates the expansion chamber, the first sealing sleeve 12 gradually expands. At this time, the fixed plate 17 fixedly arranged on the first sealing sleeve 12 moves synchronously with the first sealing sleeve 12. The fixed plate 17 drives the connecting rod 16 to rotate through the sliding block 18, thereby causing the gear 15 fixedly connected to the connecting rod 16 to rotate. Since all the gears 15 are engaged with the rack 141 on the translation column 14, all the gears 15 are in a synchronous rotation state, thereby ensuring the uniformity of the outer side of the first sealing sleeve 12 during expansion, thereby ensuring that the pipe 4 is more uniform during the radial orientation process.

[0043] Reference Figure 5 : A support shaft 19 is horizontally arranged in the ventilation pipe 11, and a translation column 14 is slidably arranged on the support shaft 19. An annular ventilation groove is present between the translation column 14 and the inner wall of the ventilation pipe 11, and an air pump 191 is arranged at the end of the ventilation pipe 11.

[0044] The translation column 14 is guided by the support shaft 19 so that the translation column 14 can slide stably in the horizontal direction.

[0045] Reference Figure 7 and Fig.10 The middle body 2 includes a first sliding sleeve 21 and a second sliding sleeve 22. The first sliding sleeve 21 is fixedly connected to the first end body 1. An extension ring 211 is fixedly provided on one end of the first sliding sleeve 21. A sleeve ring 221 is fixedly provided on the end of the second sliding sleeve 22. The sleeve ring 221 is sleeved on the periphery of the extension ring 211 and slidably cooperates with the extension ring 211.

[0046] A driving unit 23 for driving the first sliding sleeve 21 and the second sliding sleeve 22 to move relative to each other is arranged between them. The driving unit 23 includes a linear driver 231 and a rangefinder 232. The linear driver 231 is arranged horizontally on the first sliding sleeve 21 or the second sliding sleeve 22. If the linear driver 231 is arranged on the first sliding sleeve 21, the output end of the linear driver 231 is fixedly connected to the second sliding sleeve 22. If the linear driver 231 is arranged on the second sliding sleeve 22, the output end of the linear driver 231 is fixedly connected to the first sliding sleeve 21. The rangefinder 232 is horizontally arranged on the first sliding sleeve 21 or the second sliding sleeve 22. When the rangefinder 232 is arranged on the first sliding sleeve 21, the end of the rangefinder 232 is horizontally oriented toward the second sliding sleeve 22. Similarly, when the rangefinder 232 is arranged on the second sliding sleeve 22, the end of the rangefinder 232 is horizontally oriented toward the first sliding sleeve 21. The rangefinder 232 is used to measure the lengths of the first sliding sleeve 21 and the second sliding sleeve 22 after stretching. When the first sliding sleeve 21 and the second sliding sleeve 22 are stretched to a specified length, they stop moving.

[0047] Reference Fig.10 An annular second sealing sleeve 24 is arranged on the inner ring side of the extension ring 211, and the two ends of the second sealing sleeve 24 are fixedly connected to the first sliding sleeve 21 and the second sliding sleeve 22 respectively. The second sealing sleeve 24 is made of high temperature resistant elastic material.

[0048] By arranging the second sealing sleeve 24 between the first sliding sleeve 21 and the second sliding sleeve 22, when the first sliding sleeve 21 and the second sliding sleeve 22 slide relative to each other, the gap between the adjacent ends of the first sliding sleeve 21 and the second sliding sleeve 22 can be blocked by the second sealing sleeve 24, thereby preventing the tube 4 from being squeezed into the gap during the radial orientation process, resulting in deformation of the finally formed tube 4.

[0049] Reference Fig.10 An annular groove is formed between the second sealing sleeve 24 and the collar 221, and the extension ring 211 is slidably arranged in the annular groove. A valve body 25 connected to the annular groove is arranged on the collar 221. When the extension ring 211 slides out of the annular groove, the valve body 25 injects water into the annular groove.

[0050] When the extension ring 211 slides out of the annular groove, negative pressure is generated in the annular groove. At this time, the valve body 25 opens, and water flows into the annular groove through the valve body 25. When the first sliding sleeve 21 and the second sliding sleeve 22 stop moving, the radial orientation of the pipe 4 has not yet ended, that is, the pipe 4 has not yet contacted the inner ring side wall of the first sliding sleeve 21 and the inner ring side wall of the second sliding sleeve 22. Then the valve body 25 is closed. When the pipe 4 continues to expand, the water in the annular groove provides support for the pipe 4, thereby preventing the pipe 4 from squeezing and deforming the second sealing sleeve 24 during the expansion process, and preventing the pipe 4 from deforming after forming.

[0051] Reference Figure 1-Figure 11 The present invention also relates to a PE pipe forming process with biaxial orientation, which uses a PE pipe forming device with biaxial orientation. The specific process is as follows: S1, placing the pipe 4 on the ventilation pipe 11, and then closing the ends of the second end body 3 and the middle body 2, so that the first end body 1, the middle body 2 and the second end body 3 form a molding cavity; S2, the heating unit 5 starts and heats the tube 4 in the molding cavity, and hot air flows in the molding cavity; S3, the vent pipe 11 inflates the expansion chamber through the vent port 111, and the first sealing sleeve 12 squeezes the inner ring of the tube 4, so that the tube 4 expands in the radial direction, and the middle body 2 drives the tube 4 to extend in the axial direction in the horizontal direction.

[0052] Working principle: During the molding operation, the pipe 4 is inserted from the end of the middle body 2 so that the pipe 4 is sleeved on the ventilation pipe 11, and then the second end body 3 and the middle body 2 are closed. At this time, the first end body 1, the middle body 2 and the second end body 3 together form a molding cavity. The molding device also includes a heating unit 5 for heating the molding cavity. The heating unit 5 can fill the heated air into the molding cavity, so that the pipe 4 arranged on the ventilation pipe 11 can be heated by the hot air. Then the ventilation pipe 11 inflates the expansion cavity through the vent 111, so that the air pressure in the expansion cavity continues to rise, and the first sealing sleeve 12 squeezes the inner wall of the pipe 4 under the action of the air pressure, so that the diameter of the pipe 4 increases during the extrusion process. The middle body 2 gradually becomes larger, and since the middle body 2 can be stretched in the horizontal direction, and during the molding process, the two ends of the pipe 4 will be clamped by the hydraulic clamps 13 in the first end body 1 and the second end body 3 respectively. When the middle body 2 is stretched, the first end body 1 and the second end body 3 clamp the pipe 4 to stretch it, so that the pipe 4 can be oriented axially while being radially oriented, thereby improving the molding efficiency. In addition, since the present invention sets the first sealing sleeve 12 cover on the outside of the vent pipe 11, the expansion chamber formed by the inner ring side wall of the first sealing sleeve 12 and the vent pipe 11 is in a sealed state, which avoids leakage during the inflation of the expansion chamber, and also avoids a large amount of hot air from being lost due to leakage, thereby reducing energy consumption. It is worth noting that the air filled into the expansion chamber is also hot air, so that the pipe 4 can be molded faster, and the first sealing sleeve 12 can be made of high temperature resistant elastic materials such as fluororubber and thermoplastic vulcanized rubber.

[0053] The above embodiments only express one or several implementation modes of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the protection scope of the present invention. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the attached claims.

Claims

1. A PE pipe forming device with biaxial orientation, comprising a first end body (1) fixedly connected to one end of a middle body (2) and a second end body (3) arranged on the other end of the middle body (2); It is characterized in that A ventilation pipe (11) is fixedly arranged on the first end body (1) along the axial direction of the first end body (1), a first sealing sleeve (12) for supporting the pipe (4) is sleeved on the outside of the ventilation pipe (11), the first sealing sleeve (12) is made of a high-temperature resistant elastic material, an inner ring side of the first sealing sleeve (12) and an outer wall of the ventilation pipe (11) form an expansion cavity, and a plurality of ventilation ports (111) in communication with the expansion cavity are provided on the side wall of the ventilation pipe (11).

2. A PE pipe forming device with biaxial orientation according to claim 1, characterized in that: The first end body (1), the middle body (2) and the second end body (3) are closed to form a molding cavity. The molding device further comprises a heating unit (5) for heating the molding cavity. The heating unit (5) comprises an air filling port (51) provided on the first end body (1) and an air outlet (52) provided on the second end body (3). The air filling port (51) fills hot air into the molding cavity and discharges hot air from the air outlet (52).

3. A PE pipe forming device with biaxial orientation according to claim 2, characterized in that: An air heater (53) is provided on one side of the middle body (2). The air heater (53) has an input end and an output end. The inflation port (51) and the air outlet (52) are respectively connected to the output end and the input end of the air heater (53). An on-off valve (54) and a pressure relief valve (55) are provided on the upper portion of the air heater (53).

4. A PE pipe forming device with biaxial orientation according to claim 2, characterized in that: A ventilation frame (56) is provided at both the air inlet (51) and the air outlet (52), and a blocking block (57) is slidably provided on the ventilation frame (56) along the thickness direction of the ventilation frame (56). When the two blocking blocks (57) are raised to the highest position, they can respectively block the air inlet (51) and the air outlet (52).

5. The PE pipe forming device with biaxial orientation according to claim 1, characterized in that: A translation column (14) is arranged in the ventilation pipe (11) for horizontal movement. A plurality of racks (141) are evenly arranged around the translation column (14) and are parallel to the extension direction of the translation column (14). A plurality of gears (15) meshing with the racks (141) are rotatably arranged on one side of each rack (141) along the extension direction of the racks (141). The gears (15) are rotatably arranged on the ventilation port (111). A fixing plate (17) is fixedly arranged on the inner ring side wall of the first sealing sleeve (12). A sliding block (18) is horizontally slidably arranged on the fixing plate (17). A connecting rod (16) is arranged between the sliding block (18) and the gear (15). The connecting rod (16) is fixedly connected to the gear (15). The connecting rod (16) and the sliding block (18) are hinged.

6. A PE pipe forming device with biaxial orientation according to claim 5, characterized in that: A support shaft (19) is horizontally arranged in the ventilation pipe (11), a translation column (14) is slidably arranged on the support shaft (19), an annular ventilation groove is provided between the translation column (14) and the inner wall of the ventilation pipe (11), and an air pump (191) is arranged at the end of the ventilation pipe (11).

7. The PE pipe forming device with biaxial orientation according to claim 1, characterized in that: The middle body (2) comprises a first sliding sleeve (21) and a second sliding sleeve (22); the first sliding sleeve (21) is fixedly connected to the first end body (1); an extension ring (211) is fixedly provided on one end of the first sliding sleeve (21); a sleeve ring (221) is fixedly provided on the end of the second sliding sleeve (22); the sleeve ring (221) is sleeved on the periphery of the extension ring (211) and slidably cooperates with the extension ring (211).

8. A PE pipe forming device with biaxial orientation according to claim 7, characterized in that: An annular second sealing sleeve (24) is provided on the inner ring side of the extension ring (211), and two ends of the second sealing sleeve (24) are respectively fixedly connected to the first sliding sleeve (21) and the second sliding sleeve (22), and the second sealing sleeve (24) is made of a high temperature resistant elastic material.

9. A PE pipe forming device with biaxial orientation according to claim 8, characterized in that: An annular groove is formed between the second sealing sleeve (24) and the collar (221), the extension ring (211) is slidably disposed in the annular groove, and a valve body (25) connected to the annular groove is disposed on the collar (221). When the extension ring (211) slides out of the annular groove, the valve body (25) injects water into the annular groove.

10. A process for forming a PE pipe with biaxial orientation, using a PE pipe forming device with biaxial orientation as claimed in any one of claims 1 to 9, characterized in that: The specific process is as follows: S1, placing the pipe (4) on the ventilation pipe (11), and then closing the ends of the second end body (3) and the middle body (2), so that the first end body (1), the middle body (2) and the second end body (3) form a molding cavity; S2, heating the tube (4) in the molding cavity, and allowing hot air to flow in the molding cavity; S3, the vent pipe (11) inflates the expansion chamber through the vent port (111), and the first sealing sleeve (12) squeezes the inner ring of the tube (4), so that the tube (4) expands in the radial direction, and the middle body (2) drives the tube (4) to extend in the axial direction in the horizontal direction.

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