Preparation equipment and method of mine-used cross-linked polyethylene insulated cable

Abstract

This application relates to the field of cable manufacturing, specifically disclosing a manufacturing equipment and method for cross-linked polyethylene insulated cables used in mining. The manufacturing equipment includes a drawing machine body, and further includes: a drawing die, which is mounted on the drawing machine body and used for sizing and forming wire; a cooling and lubrication system, which includes: an oil supply mechanism for supplying lubricating oil to the forming hole of the drawing die and for cooling the drawing die; and a temperature control valve installed at the oil outlet of the oil supply mechanism, capable of automatically adjusting the flow area of ​​the oil outlet of the oil supply mechanism according to the temperature change of the drawing die. This application effectively improves the problems of poor lubrication and heat dissipation coordination, high energy consumption, and low heat dissipation efficiency of current drawing dies.

Description

Technical Field

[0001] This application relates to the field of cable manufacturing, and in particular to a manufacturing apparatus and method for cross-linked polyethylene insulated cables for mining applications. Background Technology

[0002] Currently, in the manufacturing of cross-linked polyethylene (XLPE) insulated cables for mining, the wire drawing machine is the most crucial conductor processing equipment at the forefront. Its function is to cold-draw copper or aluminum rods (typically Φ8mm rods) through multiple cold draws to produce single filaments of the required diameter. These single filaments will subsequently be stranded into cable conductors. Its application spans the entire initial stage from raw materials to conductor forming.

[0003] When processing the metal core of cables using a wire drawing machine, the wire is shaped primarily through a drawing die. During the drawing process, the die and the diamond wire are in close contact, resulting in a high coefficient of friction. This makes the die prone to wear and overheating, with excessive friction being a major cause of overheating (heat ≈ friction force × sliding distance). In the high-speed, large-deformation process of wire drawing, excessive friction converts a significant amount of mechanical energy into heat. This creates a vicious cycle: high friction coefficient → excessive heat generation → temperature rise → lubricant failure, metal softening → even higher friction coefficient → even more heat generation... If this cycle is not interrupted by a cooling system or process adjustments, it will quickly lead to product scrap, die damage, or wire breakage and shutdown. Therefore, in wire drawing process control, reducing the coefficient of friction and effectively controlling temperature rise are two crucial goals that must be achieved simultaneously.

[0004] Currently, the lubrication and cooling zones of wire drawing dies are typically two independent systems. Generally, a lubrication system is installed at the tapered feed end of the die, while a cooling system is arranged circumferentially on the side of the tapered hole. For example, CN214053129U discloses a diamond wire drawing die that uses a lubrication module. When the diamond wire enters through the inlet, the lubricating oil inside the module lubricates it, reducing the coefficient of friction between the diamond wire and the module, minimizing wear, and effectively extending the module's service life. The heat dissipation compression module, using a ceramic module and alloy gaskets, effectively dissipates heat generated by friction between the mold and the diamond wire by transferring the heat to the ceramic module through the alloy gaskets. Because ceramic itself has excellent heat dissipation properties and high hardness, it is not affected by high temperatures, preventing quality changes. Furthermore, the alloy gaskets are replaceable; they can be replaced when worn to a certain extent, thus preventing direct contact between the diamond wire and the ceramic module and effectively extending the module's lifespan. Additionally, a first and second water-cooling tank are provided on the front outer surface of the main body. Cooling water passes through these tanks to further dissipate heat from the ceramic module.

[0005] The aforementioned technologies have the following drawbacks: Firstly, the separation of lubrication and cooling results in poor synergy. In traditional designs, the lubrication module only provides an oil film at the feed end, while the cooling module dissipates heat around the die circumference or rear end, operating independently. This leads to the inability to directly and efficiently cool the sizing zone (middle section of the tapered bore), where frictional heat generation is most intense, resulting in severe heat accumulation. The lubricating oil rapidly fails at high temperatures, leading to poor oil film stability and a rebound in the coefficient of friction, creating a vicious cycle of "friction-heating-friction".

[0006] Secondly, existing lubrication systems mostly supply oil at a constant flow rate, and cooling systems mostly supply coolant at a constant volume. They cannot adjust the flow rate according to real-time temperature changes during the wire drawing process. To avoid overheating, the flow rate is usually set to the "maximum value required under full load conditions." In actual production, this will cause the equipment to consume more wire drawing oil each year, and the oil pump will operate at full load for a long time, which will also shorten its lifespan.

[0007] Thirdly, the cooling system indirectly dissipates heat from the tapered hole of the wire drawing die. After the tapered hole heats up, the heat is transferred to the part near the cooling tank through the heat conduction structure, and then the heat is carried away by the flowing coolant. The heat stays in the tapered hole for a long time and the heat dissipation efficiency is low.

[0008] In summary, current wire drawing dies suffer from defects such as poor lubrication and heat dissipation coordination, high energy consumption, and low heat dissipation efficiency. Summary of the Invention

[0009] To improve the current problems of poor lubrication and heat dissipation coordination, high energy consumption and low heat dissipation efficiency of wire drawing dies, this application provides a preparation equipment for cross-linked polyethylene insulated cables for mining.

[0010] The first aspect of this application provides a manufacturing apparatus for cross-linked polyethylene insulated cables used in mines, which adopts the following technical solution: A manufacturing apparatus for cross-linked polyethylene insulated cables used in mines includes a drawing machine body and further includes; A wire drawing die, which is mounted on the main body of the wire drawing machine, is used to shape and sizing wire. A cooling and lubrication system, the cooling and lubrication system comprising; An oil supply mechanism is used to supply lubricating oil into the forming hole of the wire drawing die and to cool the wire drawing die; A temperature control valve, installed at the oil outlet end of the oil supply mechanism, can automatically adjust the flow area of ​​the oil outlet end of the oil supply mechanism according to the temperature change of the wire drawing die.

[0011] Optionally, the inner wall of the forming hole is provided with multiple coaxial annular oil cavities; The oil supply mechanism includes; An oil storage tank is provided with an oil pump at its oil outlet and a filter device for filtering lubricating oil at its oil inlet. The main oil inlet pipe is used to connect the oil inlet end of the annular oil chamber and the oil outlet end of the oil pump. The main oil outlet pipe is used to connect the oil outlet end of the annular oil chamber and the oil inlet end of the filter device; The temperature control valve is used to connect the oil inlet end of the main oil inlet pipe to the oil outlet end of the oil pump.

[0012] Optionally, the temperature control valve includes; The valve body has one end connected to the oil inlet end of the main oil inlet pipe and the other end connected to the oil outlet end of the oil pump. The valve body is provided with a radially arranged sliding cavity. A valve plate is movably disposed within the sliding cavity for adjusting the flow rate of the valve body; A heat-conducting box is embedded in the discharge end of the wire drawing die and communicates with the sliding cavity; A shape memory alloy expansion joint is installed inside the heat conduction box, with one end connected to the heat conduction box and the other end connected to the valve plate. The shape memory alloy expansion joint can extend or shorten when heated to above the critical / phase change temperature.

[0013] Optionally, a dynamic sealing connection is made between the valve plate and the sliding cavity; The valve plate is provided with an oil passage hole, which coincides with part of the valve body cavity.

[0014] Optionally, the temperature control valve further includes; The guide tube is installed inside the heat-conducting box; A guide rod is coaxially and movably disposed inside the guide tube at one end, and connected to the valve plate at the other end, for guiding the movement of the valve plate.

[0015] Optionally, the cooling and lubrication system further includes an electromagnet for attracting metal debris in the annular oil chamber to the oil outlet side of the annular oil chamber, the electromagnet being disposed on the oil outlet side of the annular oil chamber.

[0016] Optionally, the cooling and lubrication system includes an air curtain assembly, which includes an annular nozzle for spraying air into the forming hole, the annular nozzle being coaxially mounted at the feed end of the drawing die.

[0017] Optionally, the oil inlet of the annular oil cavity is located above the oil outlet of the annular oil cavity.

[0018] A method for preparing a cross-linked polyethylene insulated cable for mining, based on the aforementioned equipment for preparing a cross-linked polyethylene insulated cable for mining, includes the following steps; S1. The wire to be drawn is fed into the forming hole of the wire drawing die, and the wire is pulled by the main body of the wire drawing machine to complete the sizing and drawing process. S2. Start the oil supply mechanism of the cooling and lubrication system. The lubricating oil is sent into multiple annular oil chambers on the inner wall of the forming hole through the temperature control valve and the oil inlet main pipe to lubricate and cool the wire drawing die and the wire. S3. The temperature control valve automatically adjusts the supply flow of lubricating oil according to the real-time temperature of the wire drawing die to achieve adaptive temperature control cooling lubrication. S4. After use, the lubricating oil carrying impurities flows back to the filter device through the oil outlet main pipe for filtration, and then returns to the oil storage tank for recycling.

[0019] In summary, this application includes at least one of the following beneficial technical effects: 1. In this application, the oil supply mechanism and the temperature control valve work together to automatically switch the cooling and lubrication modes according to the temperature of the wire drawing die. When the wire drawing die is at a low temperature, the primary purpose is to form a complete oil film on the wire surface, with heat dissipation and chip removal as secondary purposes. The temperature control valve is partially open, and the oil supply mechanism supplies oil at a low speed to form a complete oil film, effectively reducing friction and wear between the wire and the wire drawing die, while reducing lubricating oil consumption and equipment energy consumption. Furthermore, the flow of lubricating oil within the wire drawing die 1 can directly dissipate heat and cool the wire drawing die. When the wire drawing die is at a high temperature, the primary purpose is to dissipate heat and remove chips, with the formation of a complete oil film on the wire surface as a secondary purpose. The temperature control valve is fully open, and the oil supply mechanism increases the flow rate and velocity of the lubricating oil, directly and quickly dissipating the heat from the wire drawing die, preventing the wire drawing die from overheating. Moreover, when the high-speed oil flows through the annular oil cavity, it can promptly flush away metal chips, preventing the chips from scratching the wire surface and significantly improving the dimensional accuracy and surface quality of the conductor of the cross-linked polyethylene insulated cable for mining. The oil supply mechanism and the annular oil chamber work together to form a closed-loop circulating oil circuit. Combined with the filtration device, the lubricating oil is circulated and purified for use, reducing production costs while ensuring oil cleanliness. The oil level sensor in the oil tank can monitor the oil level in real time to avoid operation without oil. The overall structure is stable and reliable, with no complex electrical control components, strong anti-interference ability, and effectively improves the stability and production efficiency of cable manufacturing.

[0020] 2. In this application, the annular oil cavity achieves a uniform circumferential supply of lubricating oil, resulting in a more balanced cooling and lubrication effect and further extending the service life of the wire drawing die. The oil inlet of the annular oil cavity is located above the oil outlet of the annular oil cavity. The structure of the annular oil cavity with the inlet at the top and the outlet at the bottom utilizes gravity to assist the flow of lubricating oil and the settling of waste chips, further optimizing the lubrication and chip removal effects.

[0021] 3. In this application, the temperature at the discharge end of the wire drawing die is highest during operation. When the temperature control valve is working, the heat transfer box is embedded in the discharge end of the wire drawing die, transferring the working temperature of the die in real time. The shape memory alloy expansion joint inside the heat transfer box is initially in an arched plate state. At this time, the shape memory alloy expansion joint is below the critical / phase change temperature, which drives the valve plate to remain in the initial position. The oil passage hole on the valve plate coincides with the inner cavity of the valve body, and the valve body maintains a small flow area. The lubricating oil delivered by the oil pump enters the main oil inlet through this flow area, realizing low-speed, small-flow oil supply. When the temperature of the wire drawing die continues to rise, the heat is transferred to the shape memory alloy expansion joint through the heat transfer box, causing its temperature to reach above the critical / phase change temperature. At this point, the arched shape memory alloy expansion joint deforms and flattens into a straight plate. Guided by the guide rod and guide tube, the shape memory alloy telescopic component extends and pushes the valve plate to move smoothly in the sliding cavity until the oil passage hole on the valve plate completely overlaps with the inner cavity of the valve body. The valve body is in the maximum flow area state, and the lubricating oil flow rate and velocity increase synchronously. When the temperature of the wire drawing die decreases and the shape memory alloy telescopic component cools down to below the critical / phase change temperature, it automatically returns to the arched plate state, then contracts and pulls the valve plate to reset. The oil passage hole partially overlaps with the inner cavity of the valve body again, and the flow area of ​​the valve body returns to the initial state. The dynamic sealing structure between the valve plate and the sliding cavity always ensures that the oil circuit is sealed and does not leak, ensuring the stable operation of the temperature control valve and realizing the adaptive adjustment of the lubricating oil flow area.

[0022] 4. In this application, during the operation of the wire drawing die, the wire rubs against the die, generating metal scraps. These scraps accumulate in the annular oil cavity and are carried away by the flowing lubricating oil. At this time, the electromagnet operates, using magnetic attraction to promote the downward flow of the metal scraps, making it less likely for them to remain in the annular oil cavity.

[0023] 5. In this application, during wire feeding, to ensure smooth wire feeding and early application of lubricating oil, the inner diameter of the annular nozzle and the feed end of the forming hole is slightly larger than the outer diameter of the wire. Therefore, when the lubricating oil in the annular oil cavity at the feed end of the forming hole flows, part of the lubricating oil lubricates the wire surface, while the other part, although able to flow directionally under the suction of the return pump, may move towards the feed end of the forming hole during actual operation due to fluctuations in flow rate—that is, lubricating oil leakage. The air pump outputs high-pressure airflow, which in turn causes the annular nozzle to spray an annular high-pressure airflow. This annular high-pressure airflow forms an air curtain barrier, pushing the leaked lubricating oil back into the forming hole, thus avoiding lubricating oil waste and environmental pollution, and ensuring the quality of subsequent insulation coating processes. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the overall structure of an embodiment of this application; Figure 2 This is a cross-sectional structural diagram of an embodiment of this application; Figure 3 yes Figure 2 An enlarged schematic diagram of part A in the middle.

[0026] Figure label: 1. Wire drawing die; 101. Forming hole; 102. Annular oil chamber; 10. Cooling and lubrication system; 2. Oil supply mechanism; 21. Oil tank; 22. Oil pump; 23. Filter device; 24. Return pump; 25. Main oil inlet pipe; 251. Branch oil inlet pipe; 26. Main oil outlet pipe; 261. Branch oil outlet pipe; 3. Temperature control valve; 31. Valve body; 3101. Sliding chamber; 32. Valve plate; 3201. Oil passage hole; 33. Heat conduction box; 331. Heat conduction fins; 34. Shape memory alloy telescopic component; 35. Guide tube; 36. Guide rod; 4. Electromagnet; 5. Air curtain assembly; 51. Annular nozzle; 52. Air pump; 6. Wire. Detailed Implementation

[0027] The following is in conjunction with the appendix Figure 1-3 This application will be described in further detail.

[0028] This application discloses an apparatus for preparing cross-linked polyethylene insulated cables for mining.

[0029] Reference Figure 1 , Figure 2 and Figure 3 A manufacturing apparatus for cross-linked polyethylene insulated cables for mining applications includes a drawing machine body (not shown in the figure), wherein the drawing machine body is prior art, and further includes; The wire drawing die 1 is set on the main body of the wire drawing machine and is used to sizing and forming the wire 6. Specifically, the wire drawing die is provided with a horizontally set forming hole 101. After the raw wire 6 passes through the forming hole 101, it is sizing and forming into the finished wire 6. Cooling and lubrication system 10, the cooling and lubrication system 10 includes; The oil supply mechanism 2 is used to supply lubricating oil into the forming hole 101 of the wire drawing die 1 and to cool the wire drawing die 1; Thermostatic valve 3, installed at the oil outlet of oil supply mechanism 2, automatically adjusts the flow area of ​​oil outlet of oil supply mechanism 2 according to the temperature change of drawing die 1. Specifically, when drawing die 1 is at a low temperature, thermostatic valve 3 limits the flow area of ​​oil outlet of oil supply mechanism 2, so that oil supply mechanism 2 supplies lubricating oil into forming hole 101 at a low speed. When the lubricating oil flows through forming hole 101 at a low speed and low flow rate, it forms a complete oil film on wire 6, saving energy and reducing wear. At this time, the main focus is on forming a complete oil film, and heat dissipation is secondary. After the drawing die 1 continues to run, when the temperature rises to the specified temperature, thermostatic valve 3 automatically increases the flow area of ​​oil outlet of oil supply mechanism 2. As the flow rate and velocity of oil outlet of oil supply mechanism 2 increase, while lubricating oil forms an oil film on the surface of wire 6, it also washes away the waste debris worn off by wire 6 at high speed, reducing the wear of wire 6. At this time, heat dissipation is the main focus, and oil film formation is secondary.

[0030] The inner wall of the forming hole 101 is provided with multiple coaxial annular oil cavities 102; the oil inlet end of the annular oil cavity 102 is located above the oil outlet end of the annular oil cavity 102.

[0031] Oil supply mechanism 2 includes; An oil reservoir 21 is located on the side of the wire drawing machine body. The oil reservoir 21 is used to fill with lubricating oil and is equipped with a level sensor for detecting the lubricating oil level. An oil pump 22 is installed at the oil outlet of the oil reservoir 21, and a filter device 23 for filtering the lubricating oil is installed at the oil inlet. Here, any conventional device capable of filtering lubricating oil can be used. A return pump 24 is also installed at the oil inlet of the filter device 23. The main oil inlet pipe 25 is used to connect the oil inlet end of the annular oil chamber 102 and the oil outlet end of the oil pump 22. Specifically, the oil inlet end of the annular oil chamber 102 is connected to the oil outlet end of the main oil inlet pipe 25 through the oil inlet branch pipe 251. The main oil outlet pipe 26 is used to connect the oil outlet end of the annular oil chamber 102 and the oil inlet end of the filter device 23. Specifically, the oil outlet end of the annular oil chamber 102 is connected to the oil inlet end of the return pump 24 through the oil outlet branch pipe 261. The temperature control valve 3 is used to connect the oil inlet end of the oil inlet pipe 25 to the oil outlet end of the oil pump 22, and then automatically adjusts the flow rate of the oil outlet end of the oil pump 22 by the temperature control change of the drawing die 1.

[0032] Reference Figure 1 , Figure 2 and Figure 3In this embodiment, the raw material wire 6 passes through the horizontally arranged forming hole 101 on the drawing die 1 and completes the sizing and drawing process under the traction of the drawing machine body. The cooling and lubrication system 10 starts working simultaneously. The lubricating oil in the oil tank 21 is pressurized and delivered by the oil pump 22. The temperature control valve 3 adaptively adjusts the flow area at the oil outlet of the oil pump 22 according to the real-time temperature of the drawing die 1. When the drawing die 1 is in a low temperature state, the temperature control valve 3 restricts the flow area of ​​the oil passage, and the oil pump 22 supplies lubricating oil into the forming hole 101 at a low speed and small flow rate. The lubricating oil preferentially forms a complete oil film on the surface of the wire 6. When the wire is drawn... After the temperature of mold 1 rises to the specified value during continuous operation, the temperature control valve 3 automatically increases the flow area of ​​the oil passage, and the flow rate and volume of lubricating oil increase synchronously. While maintaining the oil film, it quickly removes heat and washes away the waste generated by the wear of wire 6. The lubricating oil flows in from the upper oil inlet end of multiple coaxial annular oil chambers 102 on the inner wall of the forming hole 101 and flows out from the lower oil outlet end. The lubricating oil carrying the waste is sequentially sent through the oil outlet branch pipe 261 and the oil outlet main pipe 26 into the filter device 23 for purification. After filtration, it flows back to the oil storage tank 21 for recycling. The liquid level sensor in the oil storage tank 21 monitors the lubricating oil level in real time to ensure the continuous and stable operation of the equipment.

[0033] Reference Figure 1 , Figure 2 and Figure 3 In this application, the oil supply mechanism 2 and the temperature control valve 3 work together to automatically switch the cooling and lubrication modes according to the temperature of the wire drawing die 1. When the wire drawing die 1 is at a low temperature, the primary purpose is to form a complete oil film on the surface of the wire 6, with heat dissipation and chip removal as secondary purposes. The temperature control valve 3 is in a partially open state, and the oil supply mechanism 2 supplies oil at a low speed to form a complete oil film, effectively reducing the friction and wear between the wire 6 and the wire drawing die 1, while reducing lubricating oil consumption and equipment energy consumption. Moreover, the flow of lubricating oil in the wire drawing die 1 can also directly dissipate heat and cool the wire drawing die 1. When the wire drawing die 1 is at a high temperature, the primary purpose is heat dissipation and chip removal, and the secondary purpose is to form a complete oil film on the surface of the wire 6. The temperature control valve 3 is in a fully open state, and the oil supply mechanism 2 increases the flow rate and velocity of the lubricating oil, directly and quickly dissipating the heat of the wire drawing die 1, so that the wire drawing die 1 is not prone to overheating. When the high-speed oil flows through the annular oil cavity 102, it can promptly flush away the metal waste, so that the waste is not prone to scratching the surface of the wire 6, which greatly improves the dimensional accuracy and surface quality of the conductor of the cross-linked polyethylene insulated cable for mining.

[0034] The annular oil chamber 102 ensures uniform circumferential supply of lubricating oil, resulting in more balanced cooling and lubrication and further extending the service life of the wire drawing die 1. The oil inlet of the annular oil chamber 102 is located above the oil outlet. This top-in, bottom-out structure utilizes gravity to assist lubricating oil flow and debris settling, further optimizing lubrication and debris removal. The oil supply mechanism 2 works in conjunction with the annular oil chamber 102 to form a closed-loop circulating oil circuit. Combined with the filter device 23, this achieves lubricating oil circulation and purification, reducing production costs while ensuring oil cleanliness. The oil level sensor in the oil tank 21 monitors the oil level in real time, preventing operation without oil. The overall structure is stable and reliable, with no complex electrical control components, strong anti-interference capabilities, and effectively improves the stability and production efficiency of cable manufacturing.

[0035] Reference Figure 1 , Figure 2 and Figure 3 The temperature control valve 3 includes; The valve body 31 has one end connected to the oil inlet end of the oil inlet pipe 25 and the other end connected to the oil outlet end of the oil pump 22. The valve body 31 has a radially arranged sliding cavity 3101 inside. The valve plate 32 is movably disposed within the sliding cavity 3101 and is used to adjust the flow rate of the valve body 31. Specifically, the valve plate 32 and the sliding cavity 3101 are dynamically sealed together. Any conventional dynamic sealing method that prevents oil leakage can be used between the valve plate 32 and the sliding cavity 3101. The valve plate 32 is provided with an oil passage hole 3201, which partially overlaps with the inner cavity of the valve body 31. The guide tube 35 is installed inside the heat transfer box 33; The guide rod 36 is coaxially and movably disposed inside the guide tube 35 at one end, and connected to the valve plate 32 at the other end, and is used to guide the movement of the valve plate 32. The heat-conducting box 33 is embedded in the discharge end of the wire drawing die 1 and communicates with the sliding cavity 3101. The outer wall of the heat-conducting box 33 is provided with heat-conducting fins 331. The shape memory alloy expansion joint 34 is located inside the heat conduction box 33, with one end connected to the heat conduction box 33 and the other end connected to the valve plate 32. When heated to above the critical / phase change temperature, the shape memory alloy expansion joint 34 can extend or shorten. Specifically, the shape memory alloy expansion joint 34 is an arched plate. Below the critical / phase change temperature, the shape memory alloy expansion joint 34 is in its initial state, that is, the state of an arched plate. Above the critical / phase change temperature, the shape memory alloy expansion joint 34 deforms, making the arched plate become a straight plate. Then, in the length direction of the guide rod 36, the shape memory alloy expansion joint 34 extends and pushes the valve plate 32 to move. Then, the oil passage 3201 completely overlaps with the inner cavity of the valve body 31, so that the valve body 31 is in the state of maximum flow. When the shape memory alloy expansion joint 34 is cooled to below the critical / phase transformation temperature, the shape memory alloy expansion joint 34 can return to the arched plate state, that is, the shape memory alloy expansion joint 34 can contract, pull the valve plate 32 to move, so that the valve plate 32 resets and the oil passage 3201 partially overlaps with the inner cavity of the valve body 31 again.

[0036] Reference Figure 1 , Figure 2 and Figure 3 In this embodiment, the temperature at the discharge end of the wire drawing die 1 is the highest during operation. When the temperature control valve 3 is working, the heat conduction box 33 is embedded in the discharge end of the wire drawing die 1, conducting the working temperature of the die in real time. The shape memory alloy expansion member 34 in the heat conduction box 33 is initially in an arched state. At this time, the shape memory alloy expansion member 34 is below the critical / phase change temperature, which drives the valve plate 32 to remain in the initial position. The oil passage hole 3201 on the valve plate 32 partially overlaps with the inner cavity of the valve body 31, and the valve body 31 maintains a small flow area. The lubricating oil delivered by the oil pump 22 enters the oil inlet main pipe 25 through this flow area, realizing low-speed and small-flow oil supply. When the temperature of the wire drawing die 1 continues to rise, the heat is transferred to the shape memory alloy expansion member 34 through the heat conduction box 33, causing its temperature to reach above the critical / phase change temperature. The arched shape memory alloy expansion member 34 deforms and flattens into a straight plate. Under the guidance of the guide tube 35, the shape memory alloy telescopic component 34 extends and pushes the valve plate 32 to move smoothly in the sliding cavity 3101 until the oil passage hole 3201 on the valve plate 32 completely overlaps with the inner cavity of the valve body 31. The valve body 31 is in the maximum flow area state, and the lubricating oil flow rate and velocity increase synchronously. When the temperature of the wire drawing die 1 decreases and the shape memory alloy telescopic component 34 cools down to below the critical / phase change temperature, it automatically returns to the arched plate state, and then contracts and pulls the valve plate 32 to reset. The oil passage hole 3201 re-overlaps with the inner cavity of the valve body 31, and the flow area of ​​the valve body 31 returns to the initial state. The dynamic sealing structure between the valve plate 32 and the sliding cavity 3101 always ensures that the oil circuit is sealed and does not leak oil, ensuring the stable operation of the temperature control valve 3 and realizing the adaptive adjustment of the lubricating oil flow area.

[0037] The cooling and lubrication system 10 also includes an electromagnet 4 for drawing metal debris from the annular oil chamber 102 toward the oil outlet side of the annular oil chamber 102. The electromagnet 4 is located on the oil outlet side of the annular oil chamber 102.

[0038] Reference Figure 1 , Figure 2 and Figure 3 In this embodiment, during the operation of the wire drawing die 1, the wire 6 rubs against the wire drawing die 1, generating metal scraps. These metal scraps accumulate in the annular oil cavity 102 and are carried away by the flowing lubricating oil. At this time, the electromagnet 4 operates, promoting the downward flow of metal scraps through magnetic attraction, making it less likely for the metal scraps to remain in the annular oil cavity 102.

[0039] Reference Figure 1 , Figure 2 and Figure 3 The cooling and lubrication system 10 also includes an air curtain assembly 5, which includes an annular nozzle 51 for spraying air into the forming hole 101. The annular nozzle 51 is coaxially mounted on the feed end of the drawing die 1. Specifically, the air curtain assembly 5 includes; The annular nozzle 51 is installed at the feed end of the wire drawing die 1 and is coaxial with the forming hole 101; An air pump 52 is located on the side of the wire drawing die 1, and the air outlet of the air pump 52 is connected.

[0040] Reference Figure 1 , Figure 2 and Figure 3 In this embodiment, during wire feeding, to ensure smooth feeding and early application of lubricating oil, the inner diameter of the feed end of the annular nozzle 51 and the forming hole 101 is slightly larger than the outer diameter of the wire 6. Therefore, when the lubricating oil in the annular oil cavity 102 at the feed end of the forming hole 101 flows, a portion of the lubricating oil lubricates the surface of the wire 6. While the remaining lubricating oil can flow directionally under the suction of the return pump 24, fluctuations in the lubricating oil flow during actual operation may cause it to move towards the feed end of the forming hole 101, resulting in lubricating oil leakage. The air pump 52 outputs high-pressure airflow, which causes the annular nozzle 51 to spray an annular high-pressure airflow. This annular high-pressure airflow forms an air curtain barrier, pushing the leaked lubricating oil back into the forming hole 101. This avoids lubricating oil waste and environmental pollution while ensuring the quality of subsequent insulation layer coating processes.

[0041] Reference Figure 1 , Figure 2 and Figure 3 A method for preparing cross-linked polyethylene insulated cables for mining, based on the above-mentioned equipment for preparing cross-linked polyethylene insulated cables for mining, includes the following steps; S1. The wire 6 to be drawn is introduced into the forming hole 101 of the wire drawing die 1, and the wire 6 is pulled by the main body of the wire drawing machine to complete the sizing and wire drawing forming. S2. Start the oil supply mechanism 2 of the cooling and lubrication system 10. The lubricating oil is sent into multiple annular oil chambers 102 on the inner wall of the forming hole 101 through the temperature control valve 3 and the oil inlet pipe 25 to lubricate and cool the wire drawing die 1 and the wire 6. S3, temperature control valve 3 automatically adjusts the supply flow of lubricating oil according to the real-time temperature of wire drawing die 1, so as to achieve adaptive temperature control cooling lubrication; S4. After use, the lubricating oil carrying impurities flows back to the filter device 23 through the oil outlet pipe 26 for filtration, and then returns to the oil storage tank 21 for recycling.

[0042] The implementation principle of the equipment for preparing cross-linked polyethylene insulated cables for mining in this application embodiment is as follows: the wire to be drawn passes through the forming hole 101 of the drawing die 1 and is sized and formed under the traction of the main body of the drawing machine. The cooling and lubrication system 10 is put into operation simultaneously. The lubricating oil in the oil storage tank 21 is pressurized by the oil pump 22 and delivered to the main oil inlet pipe 25 and each oil inlet branch pipe 251 through the temperature control valve 3, and then evenly enters the multiple annular oil cavities 102 on the inner wall of the forming hole 101. Since the temperature at the discharge end of the wire drawing die 1 is the highest, the heat conduction box 33 embedded in this position can transfer the die temperature in real time. Under low temperature conditions, the shape memory alloy expansion member 34 maintains the initial shape of the arched plate, so that the oil passage hole 3201 on the valve plate 32 partially overlaps with the inner cavity of the valve body 31. The lubricating oil is supplied at a small flow rate and low velocity, and a complete oil film is formed on the surface of the wire first. When the die temperature rises above the phase transformation temperature of the shape memory alloy, the shape memory alloy expansion member 34 flattens into a straight plate. Under the guidance of the guide tube 35 and the guide rod 36, it pushes the valve plate 32 to move in the sliding cavity 3101, so that the oil passage hole 3201 completely overlaps with the inner cavity of the valve body 31. The flow rate and velocity of the lubricating oil are greatly increased, which enhances heat dissipation and flushes away metal waste while maintaining the oil film. Lubricating oil flows upward and downward along the annular oil chamber 102, carrying waste debris through the oil outlet branch pipe 261 and into the main oil outlet pipe 26. Under the action of the return pump 24, it enters the filter device 23 for purification and then flows back to the oil storage tank 21 for recycling. The liquid level sensor in the oil storage tank 21 monitors the oil level in real time. The electromagnet 4 on the oil outlet side of the annular oil chamber 102 attracts metal waste debris to the oil outlet side. The annular nozzle 51 at the feed end of the wire drawing die 1 forms an annular air curtain under the drive of the air pump 52, pushing any leaking lubricating oil back into the forming hole 101, ensuring continuous and stable operation of the equipment.

[0043] Unless otherwise defined, the technical or scientific terms used in this application shall have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "first," "second," "third," and similar terms used in this application specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. The terms "an" or "a" and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms "comprising" or "including" and similar terms mean that the elements or objects preceding "comprising" or "including" encompass the elements or objects listed following "comprising" or "including" and their equivalents, and do not exclude other elements or objects. "Above," "below," "left," "right," etc., are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0044] The above are all optional embodiments of this application and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A manufacturing apparatus for cross-linked polyethylene insulated cables used in mines, comprising a drawing machine body, characterized in that: Also includes: A wire drawing die (1) is provided on the main body of the wire drawing machine and is used to shape the wire (6) into diameters. A cooling and lubrication system (10), the cooling and lubrication system (10) comprising; The oil supply mechanism (2) is used to supply lubricating oil into the forming hole (101) of the wire drawing die (1) and to cool the wire drawing die (1); The temperature control valve (3) is installed at the oil outlet end of the oil supply mechanism (2) and can automatically adjust the flow area of ​​the oil outlet end of the oil supply mechanism (2) according to the temperature change of the wire drawing die (1).

2. The equipment for preparing cross-linked polyethylene insulated cables for mining according to claim 1, characterized in that: The inner wall of the forming hole (101) is provided with multiple coaxial annular oil cavities (102). The oil supply mechanism (2) includes; An oil storage tank (21) is provided with an oil pump (22) at the oil outlet end and a filter device (23) for filtering lubricating oil at the oil inlet end. The oil inlet pipe (25) is used to connect the oil inlet end of the annular oil chamber (102) and the oil outlet end of the oil pump (22); Oil outlet pipe (26) is used to connect the oil outlet end of the annular oil chamber (102) and the oil inlet end of the filter device (23); The temperature control valve (3) is used to connect the oil inlet end of the oil inlet pipe (25) to the oil outlet end of the oil pump (22).

3. The equipment for preparing cross-linked polyethylene insulated cables for mining according to claim 2, characterized in that: The temperature control valve (3) includes; The valve body (31) is connected at one end to the oil inlet end of the oil inlet pipe (25) and at the other end to the oil outlet end of the oil pump (22). The valve body (31) is provided with a radially arranged sliding cavity (3101). A valve plate (32) is movably disposed within the sliding cavity (3101) for adjusting the flow rate of the valve body (31); A heat-conducting box (33) is embedded in the discharge end of the wire drawing die (1) and communicates with the sliding cavity (3101); A shape memory alloy expansion joint (34) is installed inside the heat conduction box (33), with one end connected to the heat conduction box (33) and the other end connected to the valve plate (32). The shape memory alloy expansion joint (34) can extend or shorten when heated to above the critical / phase change temperature.

4. The equipment for preparing cross-linked polyethylene insulated cables for mining according to claim 3, characterized in that: The valve plate (32) and the sliding cavity (3101) are dynamically sealed together; The valve plate (32) is provided with an oil passage hole (3201), which overlaps with the inner cavity of the valve body (31).

5. The equipment for preparing cross-linked polyethylene insulated cables for mining according to claim 4, characterized in that: The temperature control valve (3) also includes; A guide tube (35) is installed inside the heat-conducting box (33); The guide rod (36) is coaxially and movably disposed in the guide tube (35) at one end and connected to the valve plate (32) at the other end, and is used to guide the movement of the valve plate (32).

6. The equipment for preparing cross-linked polyethylene insulated cables for mining according to claim 2, characterized in that: The cooling and lubrication system (10) further includes an electromagnet (4) for drawing metal debris in the annular oil chamber (102) toward the oil outlet side of the annular oil chamber (102), and the electromagnet (4) is located on the oil outlet side of the annular oil chamber (102).

7. The equipment for preparing cross-linked polyethylene insulated cables for mining according to claim 2, characterized in that: The cooling and lubrication system (10) includes an air curtain assembly (5), which includes an annular nozzle (51) for spraying air into the forming hole (101), and the annular nozzle (51) is coaxially mounted on the feed end of the wire drawing die (1).

8. The equipment for preparing cross-linked polyethylene insulated cables for mining according to claim 2, characterized in that: The oil inlet of the annular oil cavity (102) is located above the oil outlet of the annular oil cavity (102).

9. A method for preparing cross-linked polyethylene insulated cables for mining, based on the equipment for preparing cross-linked polyethylene insulated cables for mining as described in any one of claims 1-8, characterized in that: Includes the following steps; S1. The wire (6) to be drawn is introduced into the forming hole (101) of the wire drawing die (1), and the wire (6) is pulled by the main body of the wire drawing machine to complete the sizing and drawing process. S2. Start the oil supply mechanism (2) of the cooling and lubrication system (10). The lubricating oil is sent into multiple annular oil chambers (102) on the inner wall of the forming hole (101) through the temperature control valve (3) and the oil inlet pipe (25) to lubricate and cool the wire drawing die (1) and the wire (6). S3, temperature control valve (3) automatically adjusts the supply flow of lubricating oil according to the real-time temperature of the wire drawing die (1) to achieve adaptive temperature control cooling lubrication; S4. After use, the lubricating oil carrying impurities flows back to the filter device (23) through the oil outlet pipe (26) for filtration, and then returns to the oil storage tank (21) for recycling.

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