Pipe coating extrusion die

Abstract

The utility model relates to the technical field of dies, in particular to a pipe coating extrusion die which comprises a mouth die, a core die and a scraping sleeve, and a conical hole penetrating through two opposite ends of the mouth die is formed in the mouth die along the axial direction of the mouth die; the core mold is arranged in the conical hole, a pipe channel penetrating through the two opposite ends of the core mold is formed in the core mold in the axial direction of the core mold, and the core mold and the conical hole form a conical compression runner without a straight section, so that the mold pressure is effectively reduced, and material melt backflow is avoided; in addition, a scraping sleeve is arranged at the discharging end of the mouth mold, a scraping hole penetrating through the two opposite ends of the scraping sleeve is formed in the scraping sleeve, the scraping hole is coaxial with the pipe channel, and due to the fact that the inner diameter of the scraping hole is slightly larger than the inner diameter of a port of the narrow-mouth end of the conical compression runner, the pipe enters the scraping hole after stretching out of the discharging end of the conical compression runner; and a coating layer coating the outer wall of the pipe can be scraped through the scraping holes, so that the size of the coating layer is effectively controlled, and the smoothness of the outer surface of the coating layer on the outer wall of the pipe is ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of molds, in particular to a pipe coating extrusion mold. Background Art

[0002] Coating extrusion is a process in which a heated melt is applied to the outer wall of a pipe body through a mold to form one or more coating layers. The flow pressure of the melt is used to coat and shape the pipe through the mold flow channel.

[0003] At present, when extruding medical thin-wall braided tubes for coating, since the medical thin-wall braided tubes require thin walls and small material output from the mold, the flow channel formed by the core mold and the die of the mold has a straight section, and the cross-sectional gap area of ​​the straight section is small, the material melt has a high pressure in the straight section, resulting in a large machine overload, high mold pressure, and material melt backflow. In order to effectively reduce the mold pressure and avoid material melt backflow, the existing tube coating extrusion mold sets the compression section flow channel formed by the core mold and the die as a conical compression flow channel, such as an extrusion coating mold disclosed in the patent (Announcement No.: CN219926852U).

[0004] However, the compression section flow channel has no straight section, which results in large fluctuations in the size of the coating layer and is difficult to control, and the outer surface of the coating layer is not smooth, resulting in a poor coating effect. Utility Model Content

[0005] One of the main purposes of the utility model is to provide a pipe coating extrusion die, which can effectively reduce the die pressure and avoid the backflow of the material melt, and can also solve the problem that the compression section flow channel formed by the core die and the mouth die of the existing pipe coating extrusion die is a conical compression flow channel without a straight section, which leads to large fluctuations in the size of the coating layer that is difficult to control, and the outer surface is not smooth, resulting in poor coating effect.

[0006] In order to achieve the above object, the utility model provides a pipe coating extrusion die, comprising:

[0007] A die, wherein the die has tapered holes extending through opposite ends of the die along its axial direction;

[0008] A core mold is arranged in the tapered hole, the outer wall of the core mold and the inner wall of the tapered hole form a tapered compression flow channel, and a pipe channel penetrating through two opposite ends of the core mold is opened in the core mold along its own axial direction;

[0009] A scraper sleeve is arranged at the discharge end of the die, and a scraper hole is opened in the scraper sleeve and passes through the opposite ends of the scraper sleeve. The scraper hole is coaxial with the pipe channel, and the inner diameter of the scraper hole is slightly larger than the inner diameter of the narrow end port of the conical compression flow channel.

[0010] Furthermore, a material clearing space is provided between the scraper sleeve and the die.

[0011] Furthermore, a fixing cylinder is sleeved on the die, a connecting column is provided on the fixing cylinder, the connecting column extends along the axial direction of the core die, and one end of the connecting column facing away from the fixing cylinder is connected to the scraping sleeve.

[0012] Furthermore, the scraper sleeve includes an outer sleeve and an inner sleeve, the outer sleeve is sleeved on the inner sleeve, and the two are clearance-matched, the outer sleeve is connected and fixed to the connecting column, and the inner sleeve is provided with a material receiving hole with a gradually changing radius along its own axial direction, the material receiving hole is coaxial with the pipe channel, the wide mouth end of the material receiving hole passes through the end face of the inner sleeve close to the die, the inner diameter of the wide mouth end of the material receiving hole is larger than the inner diameter of the scraper hole, and the scraper hole is arranged at the narrow mouth end of the material receiving hole.

[0013] Furthermore, an annular groove is opened in the middle position of the material receiving hole along its own circumference, and the annular groove transitions with the circular arc of the material receiving hole. The inner diameter of the annular groove is larger than the inner diameter of the narrow end port of the material receiving hole, and the inner diameter of the annular groove is smaller than the inner diameter of the wide end port of the material receiving hole.

[0014] Furthermore, the port at the wide-mouth end of the material receiving hole is trumpet-shaped.

[0015] Furthermore, the inner sleeve is provided with a material containing hole along its axial direction, the scraper hole is provided between the material containing hole and the material receiving hole, the material containing hole and the material receiving hole are connected through the scraper hole, the inner diameter of the material containing hole is larger than the inner diameter of the wide mouth end of the material receiving hole, and the outer sleeve is provided with a conical through hole communicating with the material containing hole at one end facing away from the die.

[0016] Furthermore, an external thread is arranged on the outer wall of one end of the connecting column for connecting with the fixing tube, and a threaded hole matching with the external thread is arranged on the end surface of the fixing tube facing the scraper sleeve.

[0017] Furthermore, a first heating device is provided on the outer wall of the scraper sleeve.

[0018] Furthermore, the utility model tube coating extrusion die also includes an outer die body and a diverter die, the outer die body is provided with a conical cavity running through its two opposite ends, the mouth die is provided at one end of the outer die body, the first end of the diverter die is connected to the end face of the outer die body facing away from the mouth die, the second end of the diverter die is provided in the conical cavity and forms a conical feed channel with the inner wall of the conical cavity, the core die is connected to the end face of the second end of the diverter die, the conical feed channel is connected with the conical compression channel, the outer die body is also provided with a feed hole communicating with the conical feed channel, and the diverter die is also provided with a pipe inlet channel coaxial with and connected to the pipe channel along its own axial direction.

[0019] Compared with the prior art, the utility model has the following beneficial effects:

[0020] The utility model of the pipe coating extrusion die inserts the core die in the tapered hole of the die, so that the compression section flow channel formed by the outer wall of the core die and the inner wall of the die is a tapered compression flow channel, that is, the flow channel formed by the core die and the die does not have a straight section, thereby effectively reducing the mold pressure and avoiding the backflow of the material melt; in addition, since the discharge end of the die is provided with a scraper sleeve, and the scraper sleeve is provided with scraper holes penetrating the opposite two ends of the scraper sleeve, and the scraper hole is coaxial with the pipe channel, and the inner diameter of the scraper hole is slightly larger than the narrow diameter of the tapered compression flow channel The inner diameter of the port end, so when the medical thin-wall braided tube extends out from the discharge end of the tapered compression flow channel and enters the scraping hole, the coating layer coated on the outer wall of the tube can be scraped flat through the scraping hole, thereby effectively controlling the size of the coating layer and ensuring the smooth surface of the coating layer on the outer wall of the tube. This solves the problem that the existing extrusion coating mold has a large fluctuation in the size of the coating layer that is difficult to control and the outer surface is not smooth, resulting in poor coating effect and other problems. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a cross-sectional view of the tube coating extrusion die of the utility model;

[0022] Figure 2 This is a schematic diagram of the structure of the tube coating extrusion die of the utility model;

[0023] Figure 3 This is a cross-sectional view of a die according to an embodiment of the utility model;

[0024] Figure 4 This is a cross-sectional view of a core mold according to an embodiment of the utility model;

[0025] Figure 5 This is a cross-sectional view of an outer mold body according to an embodiment of the utility model;

[0026] Figure 6 This is a schematic diagram of the structure of the flow divider mold according to an embodiment of the utility model;

[0027] Figure 7 This is a cross-sectional view of a flow divider mold according to an embodiment of the utility model;

[0028] Figure 8 This is a cross-sectional view of a core rod and a core mold connection structure according to an embodiment of the utility model;

[0029] Fig. 9 This is a schematic diagram of the structure of the fixed cylinder involved in the embodiment of the utility model;

[0030] Fig.10 This is a cross-sectional view of a fixed cylinder according to an embodiment of the utility model;

[0031] Fig.11 This is a cross-sectional view of an inner sleeve according to an embodiment of the utility model;

[0032] Fig.12 This is a cross-sectional view of an outer set according to an embodiment of the utility model.

[0033] Reference numerals in the accompanying drawings:

[0034] 1. Mouth die; 10. Conical hole; 101. Clamped portion; 102. Extension portion; 11. Fixing cylinder; 110. Threaded hole; 111. Second heating device; 2. Core die; 20. Conical compression channel; 21. Connecting portion; 22. Conical portion; 23. Pipe channel; 3. External die body; 30. Conical cavity; 31. Connecting groove; 32. Feeding hole; 33. Mounting position; 34. Third heating device; 4. Divider die; 4 0. Conical feed channel; 41. Conical part; 42. Fixed part; 43. Inlet pipe channel; 44. Spiral groove; 5. Core rod; 50. First channel; 51. Nut; 6. Feed mold body; 7. Inner set; 70. Scraper hole; 71. Receiving hole; 710. Annular groove; 72. Material holding hole; 8. Outer set; 80. Conical through hole; 81. Square groove; 82. Connecting hole; 83. First heating device; 9. Connecting column. DETAILED DESCRIPTION

[0035] It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0036] In the description of the present invention, it should be understood that the terms "width", "up", "down", "front", "back", "top", "bottom", etc. indicating the orientation or position relationship are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0037] In the description of the present utility model, it should be noted that, unless otherwise clearly specified and limited, the terms "install", "connect", "connect", and "set" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0038] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0039] Please refer to Figure 1-Figure 12 The utility model provides a tube coating extrusion die, comprising a mouth die 1, a core die 2 and a scraper sleeve. The mouth die 1 is provided with a tapered hole 10 penetrating through its opposite two ends along its own axial direction; the core die 2 is arranged in the tapered hole 10, the core die 2 and the mouth die 1 are coaxially arranged, the outer wall of the core die 2 and the inner wall of the tapered hole 10 form a tapered compression flow channel 20, the core die 2 is provided with a tube channel 23 penetrating through its opposite two ends along its own axial direction, the tube channel 23 matches the tube to be coated with a coating layer; the scraper sleeve is arranged at the discharge end of the mouth die 1, the scraper sleeve is provided with a scraper hole 70 penetrating through its opposite two ends, the scraper hole 70 is coaxial with the tube channel 23, and the inner diameter of the scraper hole 70 is slightly larger than the inner diameter of the narrow end port of the tapered compression flow channel 20.

[0040] It can be seen that the utility model inserts the core mold 2 into the tapered hole 10 of the die 1, so that the compression section flow channel formed by the outer wall of the core mold 2 and the inner wall of the die 1 is a tapered compression flow channel 20, that is, the flow channel formed by the core mold 2 and the die 1 does not have a straight section, thereby effectively reducing the mold pressure and avoiding the reflux of the material melt; in addition, since the discharge end of the die 1 is provided with a scraper sleeve, and the scraper sleeve is provided with a scraper hole 70 that runs through the opposite ends of itself, and the scraper hole 70 is coaxial with the pipe channel 23, and since the inner diameter of the scraper hole 70 is slightly larger than the narrow diameter of the tapered compression flow channel 20, The inner diameter of the mouth port, so when the tube (such as medical thin-walled braided tube or steel tube, etc.) extends from the discharge end of the tapered compression channel 20 and enters the scraper hole 70, the coating layer coated on the outer wall of the tube can be scraped flat through the scraper hole 70, thereby effectively controlling the size of the coating layer and ensuring the smooth surface of the coating layer on the outer wall of the tube. This solves the problem that the tapered compression channel 20 formed by the core mold 2 and the mouth mold 1 of the existing extrusion coating mold does not have a straight pressure section, resulting in large fluctuations in the size of the coating layer that is difficult to control, and the outer surface is not smooth, resulting in poor coating effect.

[0041] In one embodiment, referring to Figure 1 and Figure 2 , a clearing space is provided between the scraper sleeve and the die 1, so that the material melt adhering to the scraper hole 70 can be easily cleaned out, and the material melt can be effectively prevented from clogging the scraper hole 70. Specifically, a fixed cylinder 11 is provided on the die 1, and a connecting column 9 is provided on the fixed cylinder 11. There are two connecting columns 9, and the connecting columns 9 extend along the axial direction of the core mold 2. The ends of the two connecting columns 9 facing away from the fixed cylinder 11 are respectively connected to the opposite sides of the scraper sleeve, so that the distance between the scraper sleeve and the die 1 is the above-mentioned clearing space. In other words, it can be understood that two connecting columns 9 are provided between the outer sleeve 8 and the fixed cylinder 11, and the outer sleeve 8 and the fixed cylinder 11 are connected and fixed and kept concentric by the connecting columns 9. A connecting hole 82 is provided on the outer sleeve 8, and the outer sleeve 8 is connected to the connecting column 9 through the connecting hole 82.

[0042] In one embodiment, referring to Figure 1 and Figure 2 The connecting column 9 is provided with an external thread on the outer wall of one end thereof for connecting with the fixed cylinder 11, and a threaded hole 110 adapted to the external thread is provided on the end surface of the fixed cylinder 11 facing the scraper sleeve. That is to say, it can be understood that the connecting column 9 and the fixed cylinder 11 are connected by a threaded connection, so that the scraper sleeve can be easily removed from the fixed cylinder 11, and the scraper sleeve is convenient for cleaning. Of course, in other embodiments, the connecting column 9 can also be connected to the fixed cylinder 11 by a detachable connection method of a buckle, which is not limited here. Therefore, for those skilled in the art, by reasonably changing the connection method between the connecting column 9 and the fixed cylinder 11, it should also fall within the protection scope of the present utility model.

[0043] In one embodiment, referring to Figure 1 , Fig.11 and Fig.12 The scraper sleeve includes an outer sleeve 8 and an inner sleeve 7. The outer sleeve 8 is sleeved on the inner sleeve 7, and the two sleeves are fitted with a clearance, so that the inner sleeve 7 can be removed from the outer sleeve 8, so that it is more convenient to clean the scraper sleeve. The outer sleeve 8 is connected and fixed to the connecting column 9. A receiving hole 71 with a gradually changing radius is opened in the inner sleeve 7 along its own axial direction. The receiving hole 71 is coaxial with the pipe channel 23. The wide end of the receiving hole 71 passes through the end face of the inner sleeve 7 close to the die 1. The inner diameter of the wide end of the receiving hole 71 is larger than the inner diameter of the scraper hole 70. The scraper hole 70 is set at the narrow end of the receiving hole 71. It can be seen from this that when the tube (such as medical thin-walled braided tube or steel tube, etc.) extends out from the discharge end of the tapered compression flow channel 20 and enters the scraper hole 70, after the coating layer covering the outer wall of the tube is scraped flat through the scraper hole 70, most of the scraped material falls into the receiving hole 71. Since the inner diameter of the wide mouth end of the receiving hole 71 is larger than the inner diameter of the scraper hole 70, the material scraped from the scraper hole 70 can be prevented from clogging the scraper hole 70, thereby ensuring that the coating process proceeds stably.

[0044] In one embodiment, referring to Fig.11 , an annular groove 710 is also provided in the middle of the receiving hole 71 along its own circumference, and the annular groove 710 and the receiving hole 71 are in arc transition, which is conducive to the scraped material flowing into the annular groove 710. Since the inner diameter of the annular groove 710 is larger than the inner diameter of the narrow end of the receiving hole 71, and the inner diameter of the annular groove 710 is smaller than the inner diameter of the wide end of the receiving hole 71, the receiving area of ​​the receiving hole 71 can be increased, and the scraped material can be further prevented from clogging the scraping hole 70. In addition, the port at the wide end of the receiving hole 71 is trumpet-shaped, which is conducive to the material in the receiving hole 71, so that the material in the receiving hole 71 can be cleaned out.

[0045] In one embodiment, referring to Fig.11 , the inner sleeve 7 is provided with a material receiving hole 72 along its own axial direction, and the scraper hole 70 is provided between the material receiving hole 72 and the receiving hole 71. The material receiving hole 72 and the receiving hole 71 are connected through the scraper hole 70. The inner diameter of the material receiving hole 72 is larger than the inner diameter of the wide-mouth end of the receiving hole 71. The outer sleeve 8 is provided with a conical through hole 80 communicating with the material receiving hole 72 at one end facing away from the die 1. That is, it can be understood that when the pipe (such as a medical thin-walled braided pipe or a steel pipe, etc.) extends from the discharge end of the conical compression flow channel 20 and enters the scraper hole 70, after the coating layer coated on the outer wall of the pipe is scraped flat through the scraper hole 70, most of the scraped material falls into the receiving hole 71, and a small part falls into the material receiving hole 72, so that the scraper hole 70 can be further prevented from being blocked by the scraper hole 70.

[0046] In one embodiment, referring to Figure 1The outer wall of the scraping sleeve is provided with a first heating device 83. By adding the first heating device 83 to the outer wall of the fixed sleeve, the melt is heated twice so that it can be better coated on the pipe. Specifically, the first heating device 83 can select an existing heating structure such as a heating wire, which will not be described here.

[0047] In one embodiment, referring to Figure 1 and Figure 2 The utility model tube coating extrusion die also includes an outer die body 3, a core rod 5 and a diverter die 4. The outer die body 3 is provided with a conical cavity 30 running through the opposite ends thereof. The mouth die 1 is provided at one end of the outer die body 3. The first end of the diverter die 4 is connected to the end face of the outer die body 3 facing away from the mouth die 1. The second end of the diverter die 4 is provided in the conical cavity 30 and forms a conical feed channel 40 with the inner wall of the conical cavity 30. The core die 2 is connected to the end face of the second end of the diverter die 4. The conical feed channel 40 is connected with the conical compression channel 20. The outer die body 3 is also provided with a feed hole 32 communicating with the conical feed channel 40. The diverter die 4 is also provided with a pipe inlet channel 43 coaxial with and connected to the pipe channel 23 along its own axial direction. The mandrel 5 is plugged into the pipe inlet channel 43. The mandrel 5 can be a cylinder. A first channel 50 is provided inside the mandrel 5. The first channel 50 is coaxial with and connected to the pipe channel 23. The first channel 50 matches the pipe. The first channel 50 and the pipe channel 23 are used for pulling the braided pipe. The pipe to be coated with the coating layer passes through the first channel 50 and the pipe channel 23 in sequence. The melt enters the tapered feed channel 40 from the feed hole 32 and then enters the tapered compression channel 20. The coating layer on the outer wall of the pipe is coated and formed by the flow pressure of the melt.

[0048] In one embodiment, referring to Figure 1 and Figure 5 The outer mold body 3 as a whole can be a rectangular parallelepiped or a cylinder. A conical cavity 30 and a connecting groove 31 are respectively provided on the left and right sides of the outer mold body 3. The connecting groove 31 can be a circular groove or a square groove. The narrow end of the conical cavity 30 is connected to the connecting groove 31, and the inner diameter of the narrow end is smaller than the inner diameter of the connecting groove 31. The outer wall of the outer mold body 3 is provided with the above-mentioned feed hole 32, and the feed hole 32 is connected to the middle of the conical cavity 30 or close to the wide end of the conical cavity 30.

[0049] Reference Figure 1 , Figure 6 and Figure 7The diverter die 4 is arranged on the outer die body 3, and the diverter die 4 has a conical portion 41, which is plugged into the conical cavity 30, and the two are clearance-matched to form a conical feed channel 40; the die 1 is arranged in the connecting groove 31, and the wide mouth end of the conical hole 10 of the die 1 is connected with the narrow mouth end of the conical cavity 30, the wide mouth end of the conical hole 10 faces the diverter die 4, and the narrow mouth end of the conical hole 10 passes through the end face of the die 1 facing away from the diverter die 4, the narrow mouth end of the conical hole 10 is also the discharge end of the melt, and the narrow mouth end size of the conical hole 10 is slightly larger than the outer diameter of the pipe.

[0050] In one embodiment, referring to Figure 1 and Figure 4 The core mold 2 includes a connecting portion 21 and a conical portion 22. The connecting portion 21 can be a circular body. The connecting portion 21 and the conical portion 22 are an integral structure. The conical portion 22 is located in the conical hole 10 of the mouth mold 1. The conical portion 22 and the inner wall of the conical hole 10 of the mouth mold 1 form the above-mentioned conical compression flow channel 20; the connecting portion 21 of the core mold 2 is sleeved with the core rod 5 and abuts against the end face of the narrow end of the cone portion 41; the outer wall of the core rod 5 is connected with a nut 51. As the nut 51 is tightened, the nut 51 and the conical portion 22 clamp the diverter mold 4 to fix the core mold 2 and the core rod 5.

[0051] In summary, a tube coating extrusion die provided in an embodiment of the present application forms a conical feed channel 40 by plugging the conical portion 41 of the diverter die 4 with the conical cavity 30 of the outer die body 3. A conical hole 10 is set in the mouth die 1, and the wide mouth end of the conical hole 10 matches the narrow mouth end of the conical cavity 30. A core die 2 is inserted in the conical hole 10 to form a compression section channel connected to the conical feed channel 40. Neither the conical feed channel 40 nor the conical compression channel 20 has a straight section, thereby further effectively reducing the mold pressure and avoiding the backflow of the material melt.

[0052] In one embodiment, referring to Figure 1 , Fig. 9 and Fig.10 The fixed cylinder 11 can be a metal cylinder with a certain strength, and the fixed cylinder 11 is used to fix the die 1; the die 1 includes a clamped portion 101 and an extension portion 102, the clamped portion 101 can be a disc, the extension portion 102 can be a cylinder, and the diameter of the disc is larger than the diameter of the cylinder, the clamped portion 101 and the extension portion 102 are an integral structure, the tapered hole 10 is arranged in the extension portion 102, the clamped portion 101 is plugged into the connecting groove 31, and the thickness of the clamped portion 101 matches the depth of the connecting groove 31; the inner cavity of the fixed cylinder 11 is configured as an avoidance hole, the avoidance hole matches the extension portion 102, the fixed cylinder 11 is fixedly arranged on the end surface of the outer mold body 3 facing the scraping sleeve, the extension portion 102 passes through the avoidance hole, and the outer mold body 3 and the fixed cylinder 11 clamp the clamped portion 101 to fix the die 1.

[0053] In one embodiment, referring to Figure 1 A second heating device 111 is also provided on the outer wall of the fixed cylinder 11, and a third heating device 34 is provided on the outer wall of the outer mold body 3. The second heating device 111 and the third heating device 34 can ensure the melt temperature, which is conducive to coating the melt on the outer wall of the pipe.

[0054] In one embodiment, referring to Figure 1 The tube coating extrusion die also includes a feed die body 6, which has a feed channel inside; the outer wall of the outer die body 3 is provided with a mounting position 33 connected to the feed hole 32, the feed die body 6 is arranged in the mounting position 33, and the feed channel of the feed die body 6 is connected to the feed hole 32, so as to facilitate the entry of the melt.

[0055] In one embodiment, referring to Figure 1 and Figure 6 A spiral groove 44 is provided on the outer wall of the cone portion 41. The spiral groove 44 surrounds the cone portion 41. One end of the spiral groove 44 corresponds to the feed hole 32, and the other end is located at the small head end of the cone portion 41. The spiral groove 44 and the conical cavity 30 enclose a long spiral flow channel, thereby facilitating the flow of the melt.

[0056] In one embodiment, referring to FIG. Figure 1 , Figure 6 and Figure 7 The flow divider 4 also includes a fixing portion 42, which is a plate body and is matched and connected with the end surface of the outer mold body 3 facing away from the scraper sleeve. The fixing portion 42 and the cone portion 41 are integrally formed, and the inlet pipe channel 43 passes through the fixing portion 42 and the cone portion 41. The fixing portion 42 is fixed to the end surface of the outer mold body 3 facing away from the scraper sleeve by screws, so that the outer mold body 3 and the flow divider 4 are stably connected and easy to disassemble and repair.

[0057] In summary, the working principle of the pipe coating extrusion die provided in this application in actual application scenarios is:

[0058] When assembling the mold, insert the diverter mold 4 into the conical cavity 30 of the outer mold body 3 and fix it with screws to form a conical feed channel 40, insert the core rod 5 into the inlet channel 43 of the diverter mold 4, connect the core rod 5 and the core mold 2, and rotate the nut 51 so that the nut 51 and the core mold 2 clamp the diverter mold 4 and fix it, insert the mouth mold 1 into the connecting groove 31, and insert the conical part 22 of the core mold 2 into the conical hole 10 of the mouth mold 1 to form a conical compression channel 20 connected to the conical feed channel 40, then install the fixing cylinder 11, the first heating device 83, the second heating device 111, the third heating device 34 and the feed mold body 6, insert the inner sleeve 7 into the square groove 81 of the outer sleeve 8, and fix it with screws to form a scraping sleeve, and finally connect and fix the outer sleeve 8 and the fixing cylinder 11 through the connecting column 9 and fix them with screws.

[0059] The tube coating extrusion die provided in the embodiment of the present application forms a conical feed channel 40 by plugging the conical portion 41 of the diverter die 4 with the conical cavity 30 of the outer die body 3. A conical hole 10 is provided in the die 1, and the wide end of the conical hole 10 matches the narrow end of the conical cavity 30. A core die 2 is plugged into the conical hole 10 to form a compression section channel connected to the conical feed channel 40. The conical feed channel 40 and the conical channel have no straight sections, thereby effectively reducing the mold pressure and avoiding the backflow of the material melt. In addition, since a scraper sleeve is provided at the discharge end of the die 1, and a scraper hole 70 is provided in the scraper sleeve that runs through the opposite ends of the scraper sleeve, and the scraper hole 70 is connected to the conical hole 10, the scraper hole 70 is connected to the conical hole 10. The pipe channel 23 is coaxial, and since the inner diameter of the scraper hole 70 is slightly larger than the inner diameter of the narrow end of the tapered compression channel 20, when the pipe (such as medical thin-walled braided pipe or steel pipe, etc.) extends from the discharge end of the tapered compression channel 20 and enters the scraper hole 70, the coating layer coated on the outer wall of the pipe can be scraped flat through the scraper hole 70, thereby effectively controlling the size of the coating layer and ensuring the smooth surface of the coating layer on the outer wall of the pipe. This solves the problems of the existing extrusion coating mold, such as the tapered compression channel 20 formed by the core mold 2 and the mouth mold 1 without a straight pressure section, resulting in large fluctuations in the size of the coating layer that are difficult to control, and the uneven outer surface resulting in poor coating effect.

[0060] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A pipe coating extrusion die, characterized in that: include: A die, wherein the die has tapered holes extending through opposite ends of the die along its axial direction; A core mold is arranged in the tapered hole, the outer wall of the core mold and the inner wall of the tapered hole form a tapered compression flow channel, and a pipe channel penetrating through two opposite ends of the core mold is opened in the core mold along its own axial direction; A scraper sleeve is arranged at the discharge end of the die, and a scraper hole is opened in the scraper sleeve and passes through the opposite ends of the scraper sleeve. The scraper hole is coaxial with the pipe channel, and the inner diameter of the scraper hole is slightly larger than the inner diameter of the narrow end port of the conical compression flow channel.

2. The tube coating extrusion die according to claim 1, characterized in that: A material clearing space is provided between the scraper sleeve and the die.

3. The tube coating extrusion die according to claim 1 or 2, characterized in that: The die is sleeved with a fixing tube, the fixing tube is provided with a connecting column, the connecting column extends along the axial direction of the core die, and one end of the connecting column facing away from the fixing tube is connected to the scraping sleeve.

4. The tube coating extrusion die according to claim 3, characterized in that: The scraper sleeve includes an outer sleeve and an inner sleeve, the outer sleeve is sleeved on the inner sleeve, and the two are clearance-matched, the outer sleeve is connected and fixed to the connecting column, and a material receiving hole with a gradually changing radius is opened in the inner sleeve along its own axial direction, the material receiving hole is coaxial with the pipe channel, the wide-mouth end of the material receiving hole passes through the end face of the inner sleeve close to the die, the inner diameter of the wide-mouth end of the material receiving hole is larger than the inner diameter of the scraper hole, and the scraper hole is arranged at the narrow-mouth end of the material receiving hole.

5. The tube coating extrusion die according to claim 4, characterized in that: An annular groove is also opened in the middle position of the material receiving hole along its own circumference, and the annular groove transitions with the circular arc of the material receiving hole. The inner diameter of the annular groove is larger than the inner diameter of the narrow end port of the material receiving hole, and the inner diameter of the annular groove is smaller than the inner diameter of the wide end port of the material receiving hole.

6. The tube coating extrusion die according to claim 4, characterized in that: The port of the wide-mouth end of the material receiving hole is in a trumpet shape.

7. The tube coating extrusion die according to claim 4, characterized in that: The inner sleeve also has a material receiving hole opened in its axial direction, the scraper hole is arranged between the material receiving hole and the material receiving hole, the material receiving hole and the material receiving hole are connected through the scraper hole, the inner diameter of the material receiving hole is larger than the inner diameter of the wide mouth end of the material receiving hole, and the outer sleeve has a conical through hole opened at one end facing away from the die and communicating with the material receiving hole.

8. The tube coating extrusion die according to claim 3, characterized in that: An external thread is arranged on the outer wall of one end of the connecting column for connecting with the fixing tube, and a threaded hole matching with the external thread is opened on the end surface of the fixing tube facing the scraper sleeve.

9. The tube coating extrusion die according to claim 1, characterized in that: A first heating device is arranged on the outer wall of the scraper sleeve.

10. The tube coating extrusion die according to claim 1, characterized in that: It also includes an outer mold body and a diverter mold, wherein the outer mold body is provided with a conical cavity running through its two opposite ends, the mouth mold is provided at one end of the outer mold body, the first end of the diverter mold is connected to the end face of the outer mold body facing away from the mouth mold, the second end of the diverter mold is provided in the conical cavity and forms a conical feed channel with the inner wall of the conical cavity, the core mold is connected to the end face of the second end of the diverter mold, the conical feed channel is connected with the conical compression channel, the outer mold body is also provided with a feed hole connected with the conical feed channel, and the diverter mold is also provided with a pipe inlet channel coaxial with and connected to the pipe channel along its own axial direction.

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