Segmented extrusion die

Abstract

This utility model relates to the field of extrusion die technology and discloses a segmented extrusion die, comprising: a mandrel and a die assembly and a temperature control system; the mandrel extends along a first direction and passes through the die assembly, and an annular extrusion gap for forming a pipe is formed between the outer peripheral wall of the mandrel and the inner peripheral wall of the die assembly; the die assembly includes multiple die segments connected sequentially along the first direction, each die segment being communicatively connected to the temperature control system, and the length L of each die segment in the first direction is ≤200mm. This utility model overcomes the limitations of integral temperature control, and performs segmented temperature control of the extrusion die, improving the production efficiency and quality of the pipe.

Description

Technical Field

[0001] This utility model relates to the field of extrusion die technology, and in particular to a segmented extrusion die. Background Technology

[0002] In the production of plastic pipes, the design and manufacture of extrusion dies have a crucial impact on the quality of the final product. Taking polyethylene cross-linked pipe (PE-XA) as an example, existing plunger-type extrusion dies typically employ an integral temperature control method, which cannot provide segmented temperature control for different areas of the die. This single temperature control method struggles to meet the varying temperature requirements of pipes, especially PE-XA pipes, at different molding stages, resulting in difficulties in optimizing the pipe's surface finish and physical properties. A novel segmented extrusion die is needed to address these issues and improve pipe production efficiency and quality. Summary of the Invention

[0003] The purpose of this invention is to design a segmented extrusion die capable of segmented temperature control.

[0004] To achieve the above objectives, this utility model provides a segmented extrusion die, comprising: a mandrel and die assembly and a temperature control system;

[0005] The mandrel extends along a first direction and passes through the die assembly. An annular extrusion gap for forming a tube is formed between the outer peripheral wall of the mandrel and the inner peripheral wall of the die assembly. The die assembly includes multiple die segments connected sequentially along the first direction. Each die segment is communicatively connected to the temperature control system. The length L of the die segment in the first direction is ≤200mm.

[0006] Furthermore, the temperature control system includes multiple temperature sensors and multiple heating elements. Each temperature sensor and each heating element are connected in a corresponding manner to form a temperature control component. Each temperature control component is disposed on and connected to each of the die segments.

[0007] Furthermore, two adjacent die segments are sequentially defined as a first die segment and a second die segment along the first direction. The end face of the first die segment facing the second die segment has a connecting portion, and the end face of the second die segment facing the first die segment has a connecting groove corresponding to the connecting portion. The first die segment and the second die segment are connected to the connecting groove through the connecting portion.

[0008] Furthermore, it also includes a connector, wherein a mounting groove extending along the first direction is provided on the peripheral wall of the first mold segment, the connector passes through the mounting groove, and the connector is convex relative to the end face of the first mold segment facing the second mold segment to define the connection portion.

[0009] Furthermore, the second mold segment has an annular boss protruding from its end face facing the first mold segment, and the first mold segment has an annular groove corresponding to the annular boss on its end face facing the second mold segment. The first mold segment and the second mold segment are connected through the annular boss and the annular groove.

[0010] Furthermore, the inner peripheral wall of the die segment is provided with a heat-insulating coating layer.

[0011] Furthermore, the outer surface of the mandrel is coated with Teflon.

[0012] Furthermore, the mandrel includes an extrusion section and a feeding section connected sequentially along the first direction. The outer diameter of the feeding section gradually increases along the first direction, while the outer diameters of the extrusion sections are consistent, and there is a smooth transition between the extrusion section and the feeding section.

[0013] Furthermore, the mandrel has a liquid cooling cavity extending along the first direction inside, the mandrel has a feed end disposed relative to the first direction, the feed end has a liquid cooling port, and the liquid cooling cavity is connected to the liquid cooling port.

[0014] Furthermore, it also includes a partition plate extending along the first direction, the partition plate being disposed inside the mandrel to divide the liquid cooling cavity into a first sub-cavity and a second sub-cavity, and to divide the liquid cooling port into an inlet and an outlet, the inlet communicating with the first sub-cavity, the outlet communicating with the second sub-cavity, and a communication port being provided at one end of the partition plate opposite to the liquid cooling port, through which the first sub-cavity and the second sub-cavity are connected.

[0015] Compared with the prior art, the segmented extrusion die of this utility model embodiment has the following advantages:

[0016] The segmented extrusion die of this utility model achieves segmented temperature control of the die through the segmented setting of the die assembly, optimizes the surface finish and physical properties of the produced pipe, improves the production efficiency and quality of the pipe, and realizes efficient and stable automated pipe production. Attached Figure Description

[0017] Figure 1 This is an isometric view of a segmented extrusion die according to an embodiment of the present invention;

[0018] Figure 2 This is a cross-sectional view of the segmented extrusion die according to an embodiment of the present invention;

[0019] Figure 3 This is a left view of the segmented extrusion die according to an embodiment of the present invention;

[0020] Figure 4 This is an exploded view of the die assembly in the segmented extrusion die according to an embodiment of the present invention;

[0021] Figure 5 This is a sectional view of the die assembly in the segmented extrusion die according to an embodiment of the present invention;

[0022] Figure 6 This is an isometric view of the mandrel in the segmented extrusion die according to an embodiment of the present invention;

[0023] Figure 7 This is a cross-sectional view of the mandrel in the segmented extrusion die according to an embodiment of the present invention;

[0024] Figure 8 This is a front view of the mandrel in the segmented extrusion die according to an embodiment of the present invention;

[0025] Figure 9 yes Figure 8 Enlarged structural diagram at point A;

[0026] Figure 10 This is a front view of the partition plate in the segmented extrusion die according to an embodiment of the present utility model;

[0027] Figure 11 make Figure 10 A magnified structural diagram at point B in the middle.

[0028] In the diagram, 1 is the mandrel; 11 is the extrusion section; 12 is the feeding section; 13 is the liquid cooling cavity; 14 is the feeding end; 15 is the liquid cooling port; 2 is the die assembly; 21 is the die segment; 22 is the first die segment; 221 is the connecting part; 222 is the mounting through groove; 223 is the annular groove; 23 is the second die segment; 231 is the connecting groove; 232 is the annular boss; 3 is the annular extrusion gap; 4 is the connector; 5 is the partition plate; 51 is the connecting port; x is the first direction. Detailed Implementation

[0029] The specific embodiments of this utility model will be described in further detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate this utility model, but are not intended to limit its scope.

[0030] In the description of this utility model, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" used to indicate the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0031] In the description of this utility model, it should be understood that the terms "connected," "linked," and "fixed," etc., used in this utility model should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or a welded connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly defined. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0032] In this invention, terms such as "first" and "second" are used to describe various types of information, but this information should not be limited to these terms. These terms are only used to distinguish information of the same type from each other. For example, without departing from the scope of this invention, "first" information can also be referred to as "second" information, and similarly, "second" information can also be referred to as "first" information.

[0033] Reference Figure 1 , Figure 2 and Figure 3 A segmented extrusion die according to an embodiment of the present invention includes: a segmented extrusion die, comprising: a mandrel 1, a die assembly 2, and a temperature control system;

[0034] The mandrel 1 extends along the first direction x and passes through the die assembly 2. An annular extrusion gap for forming a tube is formed between the outer peripheral wall of the mandrel 1 and the inner peripheral wall of the die assembly 2. The die assembly 2 includes multiple die segments 21 connected sequentially along the first direction x. Each die segment 21 is communicatively connected to the temperature control system. The length L of the die segment 21 in the first direction x is ≤ 200 mm.

[0035] This application breaks through the limitations of traditional integral molds by dividing the die assembly 2 into several independent die segments 21, each independently connected to a temperature control system. This allows for individual temperature control of each die segment 21, achieving temperature gradient adjustment and optimizing the cross-linking reaction and surface finish of the pipe. The shorter die segments 21 are more compatible with automated spraying by robotic arms during manufacturing, resulting in a more uniform coating and increased spraying efficiency by over 50%, solving the challenges of spraying and temperature control with long molds. In a specific embodiment, the temperature of the die segment 21 near the feed point can be set to 100°C, and the temperature of the die segment 21 near the extrusion point can be set to 130°C.

[0036] In some improvements of this application, the temperature control system includes multiple temperature sensors and multiple heating elements. Each temperature sensor and each heating element are connected in a one-to-one correspondence to form a temperature control component. Each temperature control component is correspondingly disposed on and connected to each of the die segments 21. The temperature control system also has a central controller that is communicatively connected to each temperature control component. The central controller monitors and adjusts the temperature of each die segment 21 in real time to ensure overall process stability. The segmented temperature control technology makes the cross-linking reaction of the pipe more uniform, and the product performance (such as pressure resistance, surface smoothness, etc.) can be improved by more than 20%.

[0037] refer to Figure 4 and Figure 5 In some improvements of this application, two adjacent die segments 21 are sequentially defined as a first die segment 22 and a second die segment 23 along the first direction x. The first die segment 22 has a connecting portion 221 protruding from its end face facing the second die segment 23. The second die segment 23 has a connecting groove 231 corresponding to the connecting portion 221 on its end face facing the first die segment 22. The first die segment 22 and the second die segment 23 are connected to the connecting groove 231 via the connecting portion 221. Adjacent die segments 21 are assembled together via the connecting portion 221. This segmented locking structure facilitates the disassembly and maintenance of each die segment 21, effectively reducing maintenance downtime.

[0038] In some improvements of this application, a connector 4 is also included. A mounting groove 222 extending along the first direction x is formed on the peripheral wall of the first die segment 22. The connector 4 passes through the mounting groove 222, and the connector 4 protrudes from the end face of the first die segment 22 facing the second die segment 23 to define the connecting portion 221. Specifically, the connector 4 can be a screw. Multiple connectors 4 are provided, arranged at equal intervals along the circumference of the peripheral wall of the die segment 21, and each die segment 21 is fixed by locking the connector 4.

[0039] In some improvements of this application, the second die segment 23 has an annular boss 232 protruding from its end face facing the first die segment 22, and the first die segment 22 has an annular groove 223 corresponding to the annular boss 232 on its end face facing the second die segment 23. The first die segment 22 and the second die segment 23 are connected by the annular boss 232 and the annular groove. The annular boss 232 helps with the alignment and calibration of adjacent die segments 21 during installation. Furthermore, applying a heat-insulating coating to the end face of the annular boss 232 further ensures individual temperature control of each die segment 21, allowing for time-segmented temperature control and improving pipe performance and appearance quality. In a specific embodiment of this application, the annular boss 232 is connected to the inner peripheral wall of the second mold segment 23 and protrudes in the first direction x along the inner peripheral wall of the second mold segment 23, which can assist in guiding the connection and ensure the heat insulation effect of the connection part; the connecting groove 231 corresponding to the connector 4 is correspondingly arranged around the outer peripheral part of the annular boss 232, and is used to connect and fix the first mold segment 22 and the second mold segment 23.

[0040] In some improvements of this application, the inner peripheral wall of the die segment 21 is provided with a heat-insulating coating layer. Compared with common extrusion dies with a length of 800mm or more, the die segment 21 with a length of less than or equal to 200mm is compatible with automated spraying equipment, eliminating the need for manual spraying. This is more conducive to the spraying effect and quality of the heat-insulating coating layer, increasing the production efficiency of the die assembly 2 by 40% and reducing labor costs by 60%. The heat-insulating coating layer and the independent temperature control components of each die segment 21 work together to achieve temperature gradient regulation during the pipe extrusion process.

[0041] In some improvements of this application, the outer surface of the mandrel 1 is coated with a Teflon coating. Compared to the traditional method of covering the mandrel 1 with a Teflon shrink film, directly spraying the Teflon coating onto the outer surface of the mandrel 1 simplifies the mandrel 1 manufacturing process, reduces manual intervention, helps lower costs, and avoids film deformation under high-pressure extrusion conditions, further improving the quality and efficiency of pipe production. Specifically, the thickness of the Teflon coating is 50–100 μm.

[0042] refer to Figure 6 , Figure 8 and Figure 9In some improvements of this application, the mandrel 1 includes an extrusion section 11 and a feeding section 12 connected sequentially along the first direction x. The outer diameter of the feeding section 12 gradually increases along the first direction x, while the outer diameter of the extrusion section 11 is uniform, and the extrusion section 11 and the feeding section 12 have a smooth transition. Compared to the prior art where a slot is provided between the extrusion section 11 and the feeding section 12 to fix the Teflon shrink film, the improved mandrel 1 is coated with a Teflon coating, which allows for a smooth transition between the extrusion section 11 and the feeding section 12, reducing stress concentration at the slot and extending the service life of the mandrel 1.

[0043] refer to Figure 7 In some improvements of this application, the mandrel 1 has a liquid-cooled cavity 13 extending along the first direction x inside, the mandrel 1 has a feed end 14 positioned relative to the first direction x, and a liquid-cooled port 15 is provided on the feed end 14, the liquid-cooled cavity 13 communicating with the liquid-cooled port 15. In a specific embodiment, the mandrel 1 is cooled by oil circulation.

[0044] refer to Figure 10 and Figure 11 In some improvements of this application, a partition plate 5 extending along the first direction x is further included. The partition plate 5 is disposed inside the mandrel 1 to divide the liquid cooling cavity 13 into a first sub-cavity and a second sub-cavity, and to divide the liquid cooling port 15 into an inlet and an outlet. The inlet communicates with the first sub-cavity, and the outlet communicates with the second sub-cavity. A connecting port 51 is provided at one end of the partition plate 5 away from the liquid cooling port 15, through which the first sub-cavity and the second sub-cavity communicate. The partition plate 5 added inside the mandrel 1 divides its liquid cooling cavity 13 into a first sub-cavity and a second sub-cavity, which are interconnected to form a circulating liquid cooling path. This allows the liquid cooling oil to flow sequentially from the inlet, the first sub-cavity, the connecting port 51, the second sub-cavity, and the outlet, further ensuring a uniform and constant temperature for the mandrel 1 and avoiding localized temperature loss.

[0045] In summary, this utility model provides a segmented extrusion die that breaks through the limitations of traditional integral dies. It divides the die assembly 2 into several independent die segments 21, each independently connected to a temperature control system. This allows for individual temperature control of each die segment 21, achieving temperature gradient adjustment and optimizing the cross-linking reaction and surface finish of the pipe. The shorter die segments 21 are more compatible with automated spraying by robotic arms during manufacturing, resulting in a more uniform coating and increased spraying efficiency by over 50%, thus solving the problems of spraying and temperature control with long dies.

[0046] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of the present utility model, and these improvements and substitutions should also be considered within the protection scope of the present utility model.

Claims

1. A segmented extrusion die characterized by, include: Mandrel and die assembly and temperature control system; The mandrel extends along a first direction and passes through the die assembly. An annular extrusion gap for forming a tube is formed between the outer peripheral wall of the mandrel and the inner peripheral wall of the die assembly. The die assembly includes multiple die segments connected sequentially along the first direction. Each die segment is communicatively connected to the temperature control system. The length L of the die segment in the first direction is ≤200mm.

2. The segmented extrusion die as described in claim 1, characterized in that, The temperature control system includes multiple temperature sensors and multiple heating elements. Each temperature sensor and each heating element are connected in a corresponding manner to form a temperature control component. Each temperature control component is disposed on and connected to each of the die segments.

3. The segmented extrusion die as described in claim 1, characterized in that, Two adjacent die segments are sequentially defined as a first die segment and a second die segment along the first direction. The end face of the first die segment facing the second die segment has a connecting portion, and the end face of the second die segment facing the first die segment has a connecting groove corresponding to the connecting portion. The first die segment and the second die segment are connected to the connecting groove through the connecting portion.

4. The segmented extrusion die as described in claim 3, characterized in that, It also includes a connector, wherein a mounting groove extending along the first direction is provided on the peripheral wall of the first mold segment, the connector passes through the mounting groove, and the connector is convex relative to the end face of the first mold segment facing the second mold segment to define the connection portion.

5. The segmented extrusion die as described in claim 3, characterized in that, The second mold segment has an annular boss protruding from its end face facing the first mold segment, and the first mold segment has an annular groove corresponding to the annular boss on its end face facing the second mold segment. The first mold segment and the second mold segment are connected by the annular boss and the annular groove.

6. The segmented extrusion die as described in claim 1, characterized in that, The inner peripheral wall of the die segment is provided with a heat-insulating coating layer.

7. The segmented extrusion die as described in claim 1, characterized in that, The outer surface of the mandrel is coated with Teflon.

8. The segmented extrusion die as described in claim 1, characterized in that, The mandrel includes an extrusion section and a feeding section connected sequentially along the first direction. The outer diameter of the feeding section gradually increases along the first direction, while the outer diameters of the extrusion sections are consistent, and there is a smooth transition between the extrusion section and the feeding section.

9. The segmented extrusion die as described in claim 1, characterized in that, The mandrel has a liquid cooling cavity extending along the first direction inside, and the mandrel has a feed end that is positioned relative to the first direction. The feed end has a liquid cooling port, and the liquid cooling cavity is connected to the liquid cooling port.

10. The segmented extrusion die as described in claim 9, characterized in that, It also includes a partition plate extending along the first direction, the partition plate being disposed inside the mandrel to divide the liquid cooling cavity into a first sub-cavity and a second sub-cavity, and to divide the liquid cooling port into an inlet and an outlet, the inlet communicating with the first sub-cavity, the outlet communicating with the second sub-cavity, and a communication port being provided at one end of the partition plate opposite to the liquid cooling port, through which the first sub-cavity and the second sub-cavity are connected.

Images