Polymer fabrication pipe extruder head apparatus and method of use

Abstract

The application discloses a polymer manufacturing pipe extruder head device and a use method, relates to the technical field of polymer pipe forming processing, and comprises a feeding flange and a head body, further comprises a shunt assembly, an air floatation support limiting assembly, a core rod, a shunt cone, a die and a pressing ring; the shunt assembly comprises an outer ring, a plurality of rib plates and a center sleeve, an air channel penetrating in the axial direction is formed in the inside of each rib plate; the air floatation support limiting assembly comprises a static pressure air floatation shaft sleeve and a conical surface limiting ring, a plurality of radial throttling micro-holes and a plurality of radial throttling micro-holes are arranged on the inner wall of the static pressure air floatation shaft sleeve, a plurality of radial throttling micro-holes and a plurality of radial throttling micro-hones are arranged on the inner wall of the static pressure air floatation shaft sleeve; the static pressure air floatation shaft sleeve is press-fitted in the inside of the center sleeve; through the cooperative matching of the shunt assembly, the air floatation support limiting assembly, the core rod and the shunt cone, the industry common problem that the contact type adjusting mechanism is high-temperature stuck, the melt penetrates into the air channel and blocks the air channel, the failure of the air channel and the damage of the precision parts without protection when the air is off is effectively solved.

Description

Technical Field

[0001] This invention relates to the field of polymer pipe forming and processing technology, specifically to a polymer pipe extrusion die head device and its usage method. Background Technology

[0002] In the field of polymer pipe extrusion molding, pipe wall thickness uniformity is a core indicator for evaluating the performance of extruder heads. For large-diameter pipes, the elastic sagging deformation of the mandrel due to its own weight is one of the main causes of circumferential unevenness in pipe wall thickness.

[0003] Existing extruder heads typically employ a contact-type adjustment mechanism using mechanical set screws and eccentric sleeves to center and correct the mandrel. Under high-temperature conditions, this type of mechanism is prone to jamming of the adjustment elements or changes in the mating clearance due to differences in thermal expansion. Furthermore, the correction value is discrete and cannot be dynamically compensated in real-time based on melt pressure fluctuations and temperature changes during continuous production. Some existing technologies use gas support to provide non-contact support for the mandrel to reduce friction and wear. However, in practical applications, gas support systems face the following problems: the gas path sealing structure lacks reliability under high-temperature, high-pressure melt conditions; melt seepage into the air flotation gap can easily cause blockage and failure; when the support gas is unexpectedly interrupted, the mandrel loses support and falls freely, posing a risk of rigid contact with adjacent parts and damage to precision mating surfaces; in addition, conductive dust and continuous thermal vibration during pipe extrusion accelerate the performance degradation of electrical adjustment elements and seals, affecting the long-term operational stability of the equipment. Summary of the Invention

[0004] The purpose of this invention is to provide a device for extruding pipes made of polymer and a method of using it, so as to solve the problems mentioned in the background art, such as the contact adjustment mechanism being prone to jamming and unable to compensate in real time under high temperature conditions, the gas support system's gas path sealing structure being unreliable and prone to blockage and failure under high pressure melt environment, and the mandrel falling freely and damaging the precision mating surface when the support gas is interrupted.

[0005] To achieve the above objectives, the present invention provides the following technical solution: This invention provides a pipe extrusion die head device for polymer manufacturing, including a feed flange and a die head body, as well as a flow splitting component, an air flotation support and limiting component, a mandrel, a flow splitting cone, a die, and a pressure ring; The diversion assembly includes an outer ring, multiple stiffeners and a central sleeve, and each stiffener has an axially penetrating air passage inside. The air flotation support limiting assembly includes a static pressure air flotation bushing and a conical limiting ring. The inner wall of the static pressure air flotation bushing is provided with a fan-shaped shallow air cavity and multiple sets of radial throttling microholes. The inner wall of the static pressure air flotation bushing is provided with an annular channel and multiple oblique microholes. The static pressure air-bearing bushing is press-fitted into the center sleeve, and the static pressure air-bearing bushing is divided into an air-bearing support section and an air curtain sealing integrated section along the axial direction. The core rod is inserted through the center of the static pressure air flotation bushing, and the diverter cone is coaxially sleeved on the outside of the core rod with its left end tightly attached to the right end face of the air curtain sealing integrated section. The die is located inside the right end of the machine head body, and the pressure ring presses against the right end face of the die.

[0006] Preferably, the outer ring, multiple stiffeners, and central sleeve are integrally connected, and the multiple stiffeners are evenly distributed circumferentially between the outer ring and the central sleeve. Each air passage is axially connected to the corresponding stiffener, central sleeve, and outer ring.

[0007] Preferably, the inner wall of the air flotation support section is uniformly provided with multiple mutually isolated fan-shaped shallow air chambers. Each group of radial throttling microholes penetrates the bottom of a corresponding fan-shaped shallow air chamber. Each group of radial throttling microholes penetrates the wall thickness of the static pressure air flotation bushing and connects to the corresponding air passage. The outer wall of the static pressure air flotation bushing is symmetrically provided with O-rings for air passage sealing, and two O-rings are provided on both sides of the multiple groups of radial throttling microholes.

[0008] Preferably, the air curtain sealing integrated section has a closed annular channel inside its wall thickness, and multiple oblique micro-holes are evenly opened on the inner wall of the air curtain sealing integrated section. The multiple oblique micro-holes are connected to the inner wall and the annular channel and are inclined towards the discharge direction. Radial air inlets are symmetrically opened on the outer circle of the air curtain sealing integrated section, and two of the radial air inlets are connected to the annular channel.

[0009] Preferably, an annular thrust step and a solid isolation wall are provided between the air flotation support section and the air curtain sealing integration section. The conical limiting ring is an annular rotating part. The outer wall of the conical limiting ring is press-fitted into the inner hole of the static pressure air flotation bushing. The right end face of the conical limiting ring abuts against the left side of the solid isolation wall, and the left end face of the conical limiting ring abuts against the right side of the annular thrust step. The inner wall of the conical limiting ring is provided with an inner conical surface that is larger on the left and smaller on the right.

[0010] Preferably, the mandrel includes, in sequence along the axial direction, a support shaft section, a frustum transition section, a main rod guide section, and a shaped cylindrical section. The support shaft section is placed inside the air flotation support section, and the outer conical surface of the frustum transition section is arranged opposite to the inner conical surface of the conical surface limiting ring.

[0011] Preferably, the flow divider cone includes, in sequence along the axial direction, a positioning end face, an outer guide cone surface, and an outlet end. The left end face of the positioning end face is closely fitted with the right end face of the air curtain sealing integrated section. The outer guide cone surface forms an annular melt flow channel with the inner wall of the die head. The outlet end is directly opposite the die.

[0012] Preferably, the die includes a guide surface and a forming cylindrical surface in sequence along the axial direction, and the forming cylindrical surface of the die and the forming cylindrical section of the mandrel form an annular forming gap.

[0013] The present invention also provides a method of using a pipe extrusion die head device, which includes the following steps: Step 1: Introduce compressed air into each sector-shaped shallow air chamber to form an air film between the support shaft section and the static pressure air-bearing bushing, so that the core rod is in a suspended state. Compressed air is introduced into the annular channel and ejected through oblique micro-holes to form an air curtain; Step 2: Start the extruder. After the molten material is diverted by the diversion component, it flows forward along the flow channel between the outer guide cone surface of the diversion cone and the inner wall of the die head, and is extruded through the annular forming gap between the die and the forming cylindrical section of the mandrel. Step 3: Based on the pipe wall thickness test data, independently adjust the air supply pressure of each sector shallow air chamber, and use the air pressure difference to drive the mandrel to move radially to correct the wall thickness deviation; Step 4: When the gas supply is interrupted, the conical transition section of the mandrel falls and fits against the inner conical surface of the conical limiting ring, and the mandrel is mechanically supported by the conical limiting ring.

[0014] Compared with the prior art, the beneficial effects of the present invention are: In this invention, the coordinated operation of the diversion component, the air-float support and limiting component, the mandrel, and the diversion cone effectively solves the common industry problems of high-temperature jamming in contact-type adjustment mechanisms, melt penetration into the gas path causing blockage and failure, and damage to precision parts due to lack of protection during gas cut-off. In the air-float support section of the air-float support and limiting component, multiple isolated fan-shaped shallow air chambers achieve independent pressure regulation, which, together with radial throttling micro-orifices, form a static pressure gas film to drive the mandrel to perform micron-level radial micro-motion correction of wall thickness deviation. Symmetrically arranged double O-rings block air leakage between air chambers, ensuring stable support stiffness. In the air curtain sealing integrated section of the air-float support and limiting component, a closed annular channel provides stable pressure gas supply. The oblique micro-orifice ejection forms an outward-expanding air curtain, combined with the hard seal of the diversion cone positioning end face, doubly preventing high-pressure melt from intruding into the air flotation gap; the cone surface limiting ring adopts a bidirectional axial positioning structure, automatically bearing the weight of the mandrel when the air supply is interrupted or pressure is lost, effectively avoiding hard collision damage to the precision working surface; the ribs in the diversion assembly are arranged one-to-one with the air channels to ensure uniform air supply to each air chamber, and the spindle-shaped main rod guide section of the mandrel improves the overall rigidity and reduces bending deformation of slender rods; effectively improving the circumferential wall thickness uniformity of the pipe, reducing equipment failure downtime, extending the service life of precision components such as static pressure air flotation bushings, and improving the operational stability of continuous production. Attached Figure Description

[0015] Figure 1 This is a perspective view of the main structure in this invention; Figure 2This is a three-dimensional cross-sectional view of the structure in this invention; Figure 3 This is a schematic diagram showing the installation positions of the diversion component, the air flotation support and limiting component, and the mandrel in this invention. Figure 4 This is a schematic diagram of the installation location structure of the shunt component in this invention; Figure 5 This is a schematic diagram showing the installation positions of the outer ring, stiffening plate, and central sleeve in this invention. Figure 6 for Figure 5 Enlarged 3D view at point A in the middle; Figure 7 This is a schematic diagram of the installation position structure of the air-bearing support limiting component in this invention; Figure 8 This is a schematic diagram showing the installation positions of the annular thrust step, solid isolation wall, and conical limiting ring in this invention. Figure 9 This is a schematic diagram of the installation position structure of the annular channel and the oblique micro-holes in this invention; Figure 10 for Figure 8 Enlarged 3D view at point B; Figure 11 for Figure 8 Enlarged 3D view at point C; Figure 12 This is a schematic diagram of the mounting position structure of the core rod in this invention; Figure 13 This is a schematic diagram of the installation position structure of the flow divider cone and the die in this invention; Figure 14 This is a schematic diagram of the installation positions of the positioning end face, the outer guide cone surface, and the outlet end in this invention.

[0016] In the diagram: 100, feed flange; 200, die head body; 300, flow divider assembly; 301, outer ring; 302, stiffening plate; 303, central sleeve; 304, air passage; 400, air flotation support limiting assembly; 401, static pressure air flotation bushing; 402, fan-shaped shallow air chamber; 403, radial throttling micro-orifice; 404, O-ring; 405, annular channel; 406, oblique micro-orifice; 407, radial air inlet; 40 8. Annular thrust step; 409. Solid isolation partition wall; 410. Conical limiting ring; 500. Mandrel; 501. Support shaft section; 502. Conical transition section; 503. Main rod guide section; 504. Formed cylindrical section; 600. Diverter cone; 601. Positioning end face; 602. Outer guide cone surface; 603. Outlet end; 700. Die; 701. Guide surface; 702. Formed cylindrical surface; 800. Pressure ring. Detailed Implementation

[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] like Figures 1-3 As shown, this embodiment provides a polymer pipe extrusion die head device, including a feed flange 100 and a die head body 200, as well as a flow distribution component 300, an air flotation support and limiting component 400, a mandrel 500, a flow distribution cone 600, a die 700, and a pressure ring 800. The die head body 200 is a thick-walled cylindrical structure with an axially penetrating stepped inner hole. The feed flange 100 is fixed to the left end face of the die head body 200 to connect to the extruder outlet and guide the molten material into the internal flow channel of the die head. The pressure ring 800 is locked to the right end face of the die head body 200 by circumferential bolts to axially press and fix the die 700.

[0019] like Figures 4-6 As shown, the flow diversion assembly 300 includes an outer ring 301, multiple stiffeners 302, and a central sleeve 303. The outer circle of the outer ring 301 is fitted with the inner wall of the head body 200 and is circumferentially fixed by a locking screw. The central sleeve 303 is coaxially located at the center of the outer ring 301. Multiple stiffeners 302 are evenly distributed circumferentially between the outer ring 301 and the central sleeve 303, connecting the two into one. A fan-shaped flow gap is formed between adjacent stiffeners 302 for the melt to pass through. Each stiffener 302 has an axially penetrating air passage 304 inside. The air passage 304 extends from the outer wall of the outer ring 301 through the entire length of the stiffener 302 and extends to the inner wall of the central sleeve 303.

[0020] like Figures 7-9 As shown, the air flotation support limiting assembly 400 includes a static pressure air flotation bushing 401 and a conical limiting ring 410. The static pressure air flotation bushing 401 is a thick-walled cylindrical structure, which is press-fitted into the interior of the central sleeve 303. The static pressure air flotation bushing 401 is divided into an air flotation support section and an air curtain sealing integration section along the axial direction. The two are completely separated by a solid isolation wall 409. The solid isolation wall 409 is a section of a non-porous solid annular area on the body of the static pressure air flotation bushing 401. The inner wall of the static pressure air flotation bushing 401 has multiple fan-shaped shallow air cavities 402 and multiple sets of radial throttling microholes 403 in the air flotation support section area. The inner wall of the static pressure air flotation bushing 401 has an annular channel 405 and multiple oblique microholes 406 in the air curtain sealing integration section area. The conical limiting ring 410 is installed in the inner hole of the static pressure air flotation bushing 401 and is located between the air flotation support section and the air curtain sealing integration section.

[0021] like Figures 2-3As shown, the mandrel 500 is an integral long shaft structure, coaxially inserted into the central inner hole of the static pressure air flotation bushing 401. The rear end of the mandrel 500 is supported within the air flotation support section of the static pressure air flotation bushing 401. The front end of the mandrel 500 passes through the air curtain sealing integration section and extends out of the right end face of the die 700. The flow divider cone 600 is a hollow rotating structure, coaxially sleeved on the outside of the mandrel 500 and located between the air curtain sealing integration section and the die 700. The left end face of the flow divider cone 600 is tightly fitted to the air curtain sealing integration section. The right end face of the segment forms a hard seal. An annular gap is left between the outer cone surface of the flow divider cone 600 and the inner wall of the die head body 200 to form a melt flow channel. The die 700 is embedded in the inner stepped hole at the right end of the die head body 200. The pressure ring 800 is sleeved on the outside of the die 700. There is a gap between the inner hole of the pressure ring 800 and the outer circle of the die 700, which only bears the axial pressure. The left end face of the pressure ring 800 presses against the right end face of the die 700. The die 700 is axially locked in the die head body 200 by bolts.

[0022] like Figures 4-6 As shown, the outer ring 301, multiple stiffeners 302, and central sleeve 303 are integrally machined from the same piece of alloy steel. The outer ring 301 is embedded in the positioning step on the inner wall of the head body 200. The central through hole of the central sleeve 303 is interference-fitted with the outer circle of the static pressure air bearing bush 401. Each air passage 304 is formed by the air inlet on the outer wall of the outer ring 301, which passes radially through the outer ring 301, axially through the corresponding stiffener 302, and then radially through the wall thickness of the central sleeve 303, finally forming an air outlet on the inner wall of the central sleeve 303. The air outlets of each air passage 304 are evenly distributed circumferentially on the inner wall of the central sleeve 303 and are aligned and connected one by one with the corresponding radial throttling micro-holes 403 on the outer wall of the static pressure air bearing bush 401.

[0023] like Figure 8 and Figure 11 As shown, four mutually isolated fan-shaped shallow air chambers 402 are uniformly arranged circumferentially on the inner wall of the air flotation support section. Adjacent fan-shaped shallow air chambers 402 are separated by unprocessed sealing surfaces. A set of radial throttling micro-holes 403 are opened on the bottom surface of each fan-shaped shallow air chamber 402. Each set contains at least four radial throttling micro-holes 403. Each radial throttling micro-hole 403 penetrates the wall thickness of the static pressure air flotation bushing 401 radially and connects to the air outlet of the corresponding air passage 304. Two annular sealing grooves are symmetrically arranged on the outer wall of the air flotation support section of the static pressure air flotation bushing 401. An O-ring 404 is embedded in each sealing groove. The two O-rings 404 are located on the left and right sides of all radial throttling micro-holes 403, respectively, to prevent air leakage between adjacent fan-shaped shallow air chambers 402 through the fitting gap between the outer wall of the static pressure air flotation bushing 401 and the inner wall of the central sleeve 303.

[0024] like Figures 9-10As shown, the air curtain sealing integrated section is located at the right end of the static pressure air flotation bushing 401. A closed annular channel 405 is machined inside its wall. The annular channel 405 is a circumferentially continuous groove. Multiple oblique micro-holes 406 are evenly distributed circumferentially on the inner wall of the air curtain sealing integrated section. The inner end of each oblique micro-hole 406 opens onto the inner wall surface of the static pressure air flotation bushing 401, and the outer end opens into the annular channel 405. The axis of each oblique micro-hole 406 simultaneously points towards the discharge direction and radial direction. Inclined outwards, the angle between the air curtain sealing integrated section and the axis of the static pressure air bearing sleeve 401 is in the range of 15 degrees to 45 degrees. Two radial air inlets 407 are opened at 180-degree symmetrical positions on the outer circle of the air curtain sealing integrated section. The inner ends of the two radial air inlets 407 are connected to the annular channel 405, and the outer ends are connected to the external compressed air source through an independent air passage in the cylinder wall of the head body 200. The annular channel 405 and the fan-shaped shallow air chamber 402 on the left are completely separated by a solid isolation partition wall 409.

[0025] like Figures 7-8 As shown, in the transition area between the air flotation support section and the air curtain sealing integration section, the inner hole of the static pressure air flotation bushing 401 is provided with an annular thrust step 408. The solid isolation partition wall 409 is adjacent to the right side of the annular thrust step 408 and is an axial solid annular section on the body of the static pressure air flotation bushing 401. The conical limiting ring 410 is an independently machined and assembled annular rotating part. Its outer cylindrical surface is interference-fitted with the inner hole of the static pressure air flotation bushing 401 at the annular thrust step 408. The left end face of the conical limiting ring 410 abuts against the right end face of the annular thrust step 408, and the right end face of the conical limiting ring 410 abuts against the left end face of the solid isolation partition wall 409, forming a bidirectional axial positioning. The inner wall of the conical limiting ring 410 is machined with an inner conical surface that is larger on the left and smaller on the right, with a cone angle of 45 degrees. The surface of the conical surface is polished.

[0026] like Figure 12As shown, the mandrel 500 is machined from a single piece of alloy steel bar and includes, along the axial direction, a support shaft section 501, a frustum transition section 502, a main rod guide section 503, and a formed cylindrical section 504. The support shaft section 501 is a high-precision cylindrical surface of uniform diameter, located at the rear end of the mandrel 500. Its outer circle is mirror-polished. The support shaft section 501 is completely placed in the inner hole of the air-bearing support section of the static pressure air-bearing bushing 401. An annular air-bearing gap is left between the outer circle of the support shaft section 501 and the inner wall of the static pressure air-bearing bushing 401. The frustum transition section 502 is connected to the front end of the support shaft section 501. Its outer conical surface is a conical surface that is larger on the left and smaller on the right. The cone angle is consistent with the cone angle of the inner conical surface of the cone surface limiting ring 410. The frustum transition section 502 is located in the inner hole of the cone surface limiting ring 410. Under normal supply... In the gas state, there is a uniform circumferential gap between the outer conical surface of the frustum transition section 502 and the inner conical surface of the conical limiting ring 410. The main rod guide section 503 is connected to the front end of the frustum transition section 502. Its outer contour is a streamlined spindle shape. It gradually thickens from the small end of the frustum transition section 502 and then gradually narrows towards the discharge direction. The outer surface is a continuous smooth curved surface. The main rod guide section 503 passes through the inner hole of the air curtain sealing integrated section and extends to the center through the inner hole of the flow divider cone 600. The outer wall of the main rod guide section 503 and the inner wall of the flow divider cone 600 are in a large clearance fit. The forming cylindrical section 504 is located at the front end of the mandrel 500. It is a high-precision cylindrical surface with equal diameter. Its outer diameter determines the inner diameter of the tube. The forming cylindrical section 504 extends a distance beyond the right end face of the die 700.

[0027] like Figures 13-14 As shown, the flow divider cone 600 is an integral hollow rotating part, which includes a positioning end face 601, an outer guide cone surface 602 and an outlet end 603 in sequence along the axial direction. The positioning end face 601 is the annular plane at the left end of the flow divider cone 600. This plane is in close contact with the right end face of the air curtain sealing integrated section of the static pressure air float bushing 401, and a surface contact hard seal is formed between the two. The outer guide cone surface 602 is a streamlined cone surface that is larger on the left and smaller on the right. Its surface is polished. An annular melt flow channel that gradually narrows along the axial direction is formed between the outer guide cone surface 602 and the inner wall of the head body 200. The outlet end 603 is the annular outlet area at the right end of the flow divider cone 600, which is directly opposite the inlet of the guide surface 701 of the die 700.

[0028] like Figures 13-14 As shown, the die 700 is an integral hollow rotating part, which is embedded in the inner stepped hole at the right end of the head body 200. Along the axial direction, it includes a guide surface 701 and a forming cylindrical surface 702. The guide surface 701 is an inner conical surface that is larger on the left and smaller on the right, which receives the annular melt flow from the outlet end 603 of the flow divider cone 600. The forming cylindrical surface 702 is a high-precision cylindrical inner hole of equal diameter, and its hole diameter determines the outer diameter of the tube. An annular forming gap extending along the axial direction is formed between the forming cylindrical surface 702 and the forming cylindrical section 504 at the front end of the mandrel 500. The radial dimension of the gap is equal to the design wall thickness of the tube.

[0029] In the melt flow path, the outer ring 301, stiffener 302, and central sleeve 303 of the flow divider 300 radially divide the inner cavity of the die head body 200 into a central region and an outer annular region. After the molten material enters axially from the feed flange 100, it first faces the left end face of the central sleeve 303 and the leftmost end of the mandrel 500. The inner hole of the central sleeve 303 is interference-fitted with the outer circle of the static pressure air flotation bushing 401. The left end faces of the two are flush and there is no axial clearance. The support shaft section 501 of the mandrel 500 is completely accommodated in the inner hole of the static pressure air flotation bushing 401. There is only a certain air flotation gap between the two. The air film pressure in the gap is much higher than the melt pressure inside the die head. Therefore, the melt cannot enter the interior of the static pressure air flotation bushing 401 from the left end of the central sleeve 303.

[0030] Based on this, the fan-shaped gap between the stiffeners 302 forms the only channel for the melt to flow from the central region to the outer annular region. Driven by the extrusion pressure, the melt is diverted to the outer circumference through the gap between each stiffener 302 and enters the annular melt flow channel between the outer guide cone surface 602 of the diversion cone 600 and the inner wall of the die head body 200. The positioning end face 601 at the left end of the diversion cone 600 is tightly attached to the right end face of the air curtain sealing integrated section, forming a surface contact hard seal, which closes the axial passage between the central through hole of the diversion cone 600 and the area where the left air flotation support limiting component 400 is located, blocking the main path of the melt to seep into the central region in reverse.

[0031] Based on this, the air curtain sealing integrated section continuously sprays compressed air with a pressure higher than the melt pressure inside the die head through the oblique micro-holes 406, forming a conical air curtain wall that expands both in the discharge direction and radially outward at the outlet of the static pressure air float bushing 401. This creates a reverse thrust and aerodynamic barrier against the trace melt attempting to seep inward along the outer wall of the mandrel 500 towards the left air float gap. The solid isolation partition 409 on the static pressure air float bushing 401 body is a solid metal section that completely physically isolates the air curtain sealing integrated section from the air float support section in the axial direction, ensuring that even if there is a trace amount of melt residue on the air curtain side, it cannot continue to diffuse into the left air float gap area. The above-mentioned four-fold protection of left-end air film sealing, end face hard sealing, air curtain barrier and solid isolation together ensure that the internal core area of ​​the air float support limiting component 400 remains free of melt intrusion throughout the entire production process.

[0032] After assembly, the die head body 200 is installed at the discharge port of the extruder via the feed flange 100. The compressed air pipeline is connected, and filtered and stabilized compressed air is introduced into the independent air passages corresponding to each fan-shaped shallow air chamber 402. The gas enters each fan-shaped shallow air chamber 402 through the air passage 304 and the radial throttling micro-hole 403, forming a uniform static pressure air film between the support shaft section 501 and the static pressure air float sleeve 401, suspending the mandrel 500 at the center of the static pressure air float sleeve 401. At the same time, compressed air with a pressure slightly higher than the melt pressure inside the die head body 200 is introduced into the annular channel 405. After the gas is stabilized by the annular channel 405, it is obliquely sprayed out from each inclined micro-hole 406 in the discharge direction and radially outward, forming a circumferentially expanding conical air curtain wall at the inner hole outlet of the air curtain sealing integrated section, preventing the melt from seeping into the air float gap.

[0033] After the extruder is started, the molten polymer material enters the inner cavity of the die head body 200 through the feed flange 100. It is then diverted to the outer circumference through the fan-shaped gap between the ribs 302 of the diversion assembly 300. The diverted melt enters the annular flow channel between the outer guide cone surface 602 of the diversion cone 600 and the inner wall of the die head body 200. In the flow channel, it is further homogenized by the outer cone surface of the diversion cone 600. Then, it is guided by the guide surface 701 of the die 700 to the annular forming gap between the forming cylindrical surface 702 and the forming cylindrical section 504 of the mandrel 500. Finally, it is extruded from the right end of the die 700 to form a continuous pipe.

[0034] During the production process, a laser wall thickness detection ring located downstream of the die 700 collects the circumferential wall thickness data of the pipe in real time and transmits it to an external controller. The controller independently adjusts the air supply pressure of each fan-shaped shallow air chamber 402 according to the wall thickness deviation value. The air pressure difference between each air chamber drives the support shaft section 501 of the mandrel 500 to make a micron-level radial offset within the air float gap. This radial offset is rigidly transmitted to the forming cylindrical section 504 through the frustum transition section 502 and the main rod guide section 503, changing the circumferential gap distribution between the forming cylindrical section 504 and the forming cylindrical surface 702 of the die 700, thereby continuously correcting the pipe wall thickness deviation in real time.

[0035] When the compressed air supply is interrupted due to a failure in the air supply system, the air film inside the static pressure air flotation sleeve 401 disappears instantly, and the mandrel 500 loses its air flotation support and sinks as a whole under its own gravity. At this time, the outer conical surface of the frustum transition section 502 of the mandrel 500 falls down and fits tightly against the inner conical surface of the conical surface limiting ring 410. The conical surface limiting ring 410 abuts against the axial positioning structure of the annular thrust step 408 and the solid isolation partition wall 409 at its left and right end faces respectively, bearing all the load transmitted by the mandrel 500 and transmitting the load to the static pressure air flotation sleeve 401 and the diversion assembly 300. The conical surface limiting ring 410 provides rigid mechanical support for the mandrel 500, preventing hard collisions and scratches between the support shaft section 501 of the mandrel 500 and the inner wall of the static pressure air flotation sleeve 401, and between the forming cylindrical section 504 and the inner wall of the die 700. The equipment automatically and safely shuts down.

[0036] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A pipe extrusion die head device made of polymer, comprising a feed flange (100) and a die head body (200), characterized in that: It also includes a flow divider assembly (300), an air flotation support and limiting assembly (400), a mandrel (500), a flow divider cone (600), a die (700), and a pressure ring (800); The diversion assembly (300) includes an outer ring (301), multiple stiffeners (302) and a central sleeve (303), and each stiffener (302) has an axially through air passage (304) inside. The air flotation support limiting assembly (400) includes a static pressure air flotation bushing (401) and a conical limiting ring (410). The inner wall of the static pressure air flotation bushing (401) is provided with a fan-shaped shallow air cavity (402) and multiple sets of radial throttling microholes (403). The inner wall of the static pressure air flotation bushing (401) is provided with an annular channel (405) and multiple oblique microholes (406). The static pressure air-bearing bushing (401) is press-fitted into the center sleeve (303). The static pressure air-bearing bushing (401) is divided into an air-bearing support section and an air curtain sealing integrated section along the axial direction. The core rod (500) is inserted through the center of the static pressure air float bushing (401), and the diverter cone (600) is coaxially sleeved on the outside of the core rod (500) with its left end tightly attached to the right end face of the air curtain sealing integrated section. The die (700) is located inside the right end of the head body (200), and the pressure ring (800) presses against the right end face of the die (700).

2. The extrusion die head device for manufacturing pipes from polymers according to claim 1, characterized in that: The outer ring (301), multiple stiffeners (302) and central sleeve (303) are integrally connected. The multiple stiffeners (302) are evenly distributed circumferentially between the outer ring (301) and the central sleeve (303). Each air passage (304) is axially connected to the corresponding stiffener (302), central sleeve (303) and outer ring (301).

3. The extrusion die head device for manufacturing pipes from polymers according to claim 1, characterized in that: The inner wall of the air flotation support section is uniformly provided with multiple mutually isolated fan-shaped shallow air chambers (402). Each group of radial throttling micro-holes (403) penetrates the bottom of a corresponding fan-shaped shallow air chamber (402). Each group of radial throttling micro-holes (403) penetrates the wall thickness of the static pressure air flotation bushing (401) and connects to the corresponding air passage (304). The outer wall of the static pressure air flotation bushing (401) is symmetrically provided with O-rings (404) for air passage sealing, and two O-rings (404) are provided on both sides of the multiple groups of radial throttling micro-holes (403).

4. The extrusion die head device for manufacturing pipes from polymers according to claim 1, characterized in that: The air curtain sealing integrated section has a closed annular channel (405) inside its wall thickness. Multiple oblique micro-holes (406) are evenly opened on the inner wall of the air curtain sealing integrated section. The multiple oblique micro-holes (406) are connected to the inner wall and the annular channel (405) and are inclined towards the discharge direction. Radial air inlets (407) are symmetrically opened on the outer circle of the air curtain sealing integrated section. Two radial air inlets (407) are connected to the annular channel (405).

5. The extrusion die head device for manufacturing pipes from polymers according to claim 1, characterized in that: An annular thrust step (408) and a solid isolation wall (409) are provided between the air flotation support section and the air curtain sealing integration section. The conical limiting ring (410) is an annular rotating part. The outer wall of the conical limiting ring (410) is press-fitted into the inner hole of the static pressure air flotation bushing (401). The right end face of the conical limiting ring (410) abuts against the left side of the solid isolation wall (409), and the left end face of the conical limiting ring (410) abuts against the right side of the annular thrust step (408). The inner wall of the conical limiting ring (410) is provided with an inner conical surface that is larger on the left and smaller on the right.

6. The extrusion die head device for manufacturing pipes from polymers according to claim 5, characterized in that: The core rod (500) includes, in sequence along the axial direction, a support shaft section (501), a frustum transition section (502), a main rod guide section (503), and a shaped cylindrical section (504). The support shaft section (501) is placed inside the air flotation support section, and the outer conical surface of the frustum transition section (502) is arranged opposite to the inner conical surface of the conical surface limiting ring (410).

7. The extrusion die head device for manufacturing pipes from polymers according to claim 1, characterized in that: The diverting cone (600) includes, in sequence along the axial direction, a positioning end face (601), an outer guide cone face (602), and an outlet end (603). The left end face of the positioning end face (601) is closely attached to the right end face of the air curtain sealing integrated section. The outer guide cone face (602) forms an annular melt flow channel with the inner wall of the head body (200). The outlet end (603) is directly opposite the die (700).

8. The extrusion die head device for manufacturing pipes from polymers according to claim 1, characterized in that: The die (700) includes a guide surface (701) and a forming cylindrical surface (702) in sequence along the axial direction. The forming cylindrical surface (702) of the die (700) and the forming cylindrical section (504) of the mandrel (500) form an annular forming gap.

9. A method of using a pipe extrusion die head device, characterized in that: The method of using a polymer-manufactured pipe extrusion head device according to any one of claims 1 to 8 includes the following steps: S1: Compressed air is introduced into each fan-shaped shallow air cavity (402) to form an air film between the support shaft section (501) and the static pressure air float sleeve (401), so that the core rod (500) is in a suspended state. Compressed air is introduced into the annular channel (405) and sprayed out through the oblique micro-holes (406) to form an air curtain; S2: Start the extruder. After the molten material is diverted by the diversion component (300), it flows forward along the flow channel between the outer guide cone surface (602) of the diversion cone (600) and the inner wall of the die head body (200). It is then extruded through the annular forming gap between the die (700) and the forming cylindrical section (504) of the mandrel (500). S3: Based on the pipe wall thickness detection data, independently adjust the air supply pressure of each sector shallow air chamber (402), and use the air pressure difference to drive the mandrel (500) to move radially to correct the wall thickness deviation. S4: When the gas supply is interrupted, the frustum transition section (502) of the mandrel (500) falls and fits against the inner conical surface of the conical limiting ring (410), and the mandrel (500) is mechanically supported by the conical limiting ring (410).

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