A cooling device and method for controlling the degree of bending in the extrusion of cable insulation

Abstract

A kind of cooling device and method for controlling bending degree of cable insulation layer extrusion forming, the cable after extrusion is cooled by cooling water tank, a plurality of underwater distance measuring sensors are arranged on the two side walls of water tank to form an array, and the distance between the array and the cable is monitored in real time;At the same time, cold water pipes are also arranged on the two side walls of water tank, and the pipe openings are aligned with the cable to spray water, and the distance signal between the cable and the distance measuring sensor is detected to determine whether the cable is bent, and then the water inlet pipe proportional valve is controlled to enter cold water to forcibly cool one side of the cable, so as to change the bending degree of cable deformation.The present application changes the status quo of uneven cooling speed and bending deformation of cable in traditional cable extrusion production, and solves the problem of uneven cooling and bending deformation of cable by intelligently monitoring the position of cable and controlling the change of cold water inflow on both sides of cable, so as to finally improve the quality of cable product and have good industrial application prospect.

Description

Technical Field

[0001] This invention relates to the field of cable technology, specifically to a cooling device and method for controlling the curvature of cable insulation layer during extrusion molding. Background Technology

[0002] The extrusion molding and cooling of cable insulation are crucial steps in cable production, directly impacting the cable's insulation performance, mechanical strength, and service life. The current conventional production process involves placing the conductive cable core on a reel (pre-processed through drawing, stranding, and covering with insulating paper), then pulling it through an extruder under high temperature and pressure to uniformly coat the core surface with a plastic or rubber compound, forming the insulation layer. The core is then immediately cooled and shaped in a water cooling tank, followed by drying, and finally rolled into a coil. The industry currently faces the following challenges: Uneven cable cooling and bending deformation: In the traditional water tank cooling process, the cable core is slightly eccentric, which leads to slight uneven thickness of the insulation layer. During the cooling process in the water cooling tank, the cable will bend due to the uneven cooling speed. If the bending deformation exceeds the tolerance, it will be detrimental to the subsequent winding process, resulting in excessive gaps in the winding.

[0003] In response to the aforementioned technical bottlenecks, numerous patented technologies have emerged in recent years aimed at optimizing the cable extrusion cooling process, some of which are listed below: Existing patents, such as CN201910984494.4 (a cooling device for cable production), employ a combined cooling process of spray cooling, multi-stage cooling water tanks, and heated air drying. Its advantages include: effectively preventing insulation layer cracking and blistering, and allowing for the recycling of cooling water. Another existing patent, CN202420912536.X (a cooling device for cable production), divides the water tank into hot water, ambient temperature, and cold water compartments. It utilizes vortex tubes to generate cold and hot airflows to regulate the water temperature, creating a temperature gradient to prevent excessive temperature differences from affecting insulation performance. Furthermore, it uses treated exhaust air to remove moisture from the cable surface. All of these existing patent technologies share common problems: first, they do not consider the problem of uneven cable cooling and bending deformation; second, the system has high energy consumption and low cooling efficiency; third, the cooling water tank structure is prone to deformation and is inconvenient for lifting and transporting on production lines, making it difficult to adapt to the production needs of multiple product specifications; and fourth, there is a lack of solutions for treating water mist, leading to a humid workshop environment.

[0004] In summary, through the analysis of existing patented technologies, although existing technologies have proposed improvement solutions in terms of cooling uniformity, none of them address the problem of uneven cable cooling and bending deformation. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides a cooling device and method for controlling the bending degree of cable insulation layer extrusion molding. This method changes the current situation of uneven cooling speed and bending deformation of cables in traditional cable extrusion production. By intelligently monitoring the cable position and controlling the changes in the amount of cold water entering the cable on both sides, the problem of uneven cooling and bending deformation of cables is solved, ultimately improving the subsequent quality of cable products and showing good prospects for industrial application.

[0006] To achieve the above objectives, the technical solution of the present invention is as follows: A cooling device and method for controlling the bending degree of cable insulation layer extrusion molding is disclosed. The extruded cable is cooled by passing it through a cooling water tank. Several underwater distance sensors are arranged in an array on both sides of the cooling water tank to monitor the distance between the sensor and the cable in real time. At the same time, cold water pipes are also installed on both sides of the cooling water tank, with the pipe openings spraying water onto the cable. The distance sensor detects the distance signal between the sensor and the cable to determine whether the cable is bent. Then, the proportional valve of the water inlet pipe is controlled to introduce cold water to force cooling one side of the cable, thereby changing the bending degree of the cable deformation.

[0007] The method for controlling cable cooling bending deformation includes the following steps: The distances L measured by the range sensor array are L1, L2, L3, L4 and L5, L6, L7, L8 in the order of the extrusion direction, with a manually set threshold a. Case (1): When L1 < L2 < L3 < L4 and |L1-L4|≥a are satisfied simultaneously, it means that the cable is bent to the opposite side. Then the proportional valve of the water inlet pipe on this side is opened and the proportional valve of the water inlet pipe on the opposite side is closed, and cold water is introduced into the surface of the cable for cooling. At this time, the ranging sensor array on the other side should satisfy: L5 > L6 > L7 > L8, and |L5-L8|≥a as the verification of the detection. Case (2): When L1 > L2 > L3 > L4 and |L1-L4|≥a are satisfied simultaneously, it means that the cable is bent to that side. Then the proportional valve of the water inlet pipe on that side is closed and the proportional valve of the water inlet pipe on the opposite side is opened, and cold water is introduced into the surface of the cable to cool it down. At this time, the ranging sensor array on the other side should satisfy: L5 < L6 < L7 < L8, and |L5-L8|≥a as the verification of the detection. Case (3): When |L1-L4|≤a, it means that the bending degree of the cable is within the allowable tolerance range, so the proportional valves of the water inlet pipes on both sides are closed and not started; at this time, the ranging sensor array on the other side should satisfy: |L5-L8|≤a as a verification of the detection.

[0008] When 2a ≥ |L1-L4| > a, the opening degree of the proportional valve in the water inlet pipe is 30%; when 3a ≥ |L1-L4| > 2a, the opening degree of the proportional valve in the water inlet pipe is 70%; when |L1-L4| > 3a, the opening degree of the proportional valve in the water inlet pipe is 100%. This design allows for precise control of the amount of cooling water supplied to the cable undergoing bending deformation, improving the control accuracy of bending deformation, resulting in better cable straightness and significantly improving production quality and efficiency. Simultaneously, it also greatly saves water resources, reduces refrigeration energy consumption, and effectively lowers production costs.

[0009] The ranging sensor and the proportional valve of the inlet pipe are both connected to the PLC signal. The ranging sensor is an underwater ultrasonic sensor. The PLC signal transmission is stable and reliable, ensuring the continuity and stability of production. The high-frequency underwater ultrasonic sensor is based on the propagation and reflection characteristics of ultrasonic waves underwater. It calculates the distance by measuring the time difference between the emission and reception of the reflected signal of the ultrasonic wave, enabling real-time and accurate distance measurement of the cable position.

[0010] The cable core is first pulled into the extruder by the traction machine on the wire feeding reel. After passing through the extruder, an insulation layer is formed on the outer surface. At the same time, the exhaust gas absorber above the extruder is running. Then, the extruded cable is cooled down by passing through a cooling water tank. After cooling, the moisture adhering to the cable insulation layer is dried by the air pipe behind the cooling water tank, and finally, the cable is rolled up.

[0011] The cable core is preheated before entering the extruder at a temperature of 100±10℃; the extrusion speed is 5~8m / min and the screw speed of the extruder is 20~30r / min; several water temperature sensors are placed in the cooling water tank to monitor the cooling water temperature in real time and keep it between 8~15℃.

[0012] This invention employs an intelligent monitoring and control system to control the cooling and bending deformation of the cable, resulting in strong production continuity. The produced cables exhibit minimal bending deformation and high straightness accuracy, making it suitable for the production of cables of different specifications and applicable to a wide range of fields.

[0013] The cooling water tank consists of a main tank in the middle and auxiliary tanks at both ends. Several support seats are provided at the bottom. Several support rollers are installed inside both the main and auxiliary tanks. A filter screen is installed at the bottom of the auxiliary tanks. The bottoms of the main and auxiliary tanks are connected to the cooling water tank outlets. The cooling water tank inlets are located on the side walls of the main tank at the far end of the extrusion process. A distance sensor and cold water pipes are located on the side walls of the main tank near the extrusion process. The cold water pipes are connected to one end of a cold water pump, and the other end of the cold water pump is connected to the outlet of the cold water tank below the cooling water tank. Movable baffles are inserted at both ends of the main tank, with the baffle at the inlet end being lower than the baffle at the outlet end. Several lifting lugs are provided on the upper part of the cooling water tank cover, and handles are provided on the tank cover. Several reinforcing ribs are provided on the outer wall of the cooling water tank.

[0014] The cooling water in the cooling water tank flows from the outlet end to the inlet end of the main tank. Most of the overflowing cooling water eventually flows out from the secondary tank at the inlet end (at this time, all cooling water outlets at the bottom of the main tank are closed), and flows through pipes to the cooling tower outside the workshop. The cooled water from the cooling tower then flows back into the main tank through pipes, achieving heat exchange and recycling. The water temperature flowing into the cooling water tank is maintained between 30-34℃. The cooling water outlet at the bottom of the main tank is used to drain the cooling water from the main tank when production stops, keeping the cooling water tank dry.

[0015] The chilled water used to adjust cable bends comes from an industrial chiller. The chiller prepares the chilled water and pumps it into a chilled water tank for temporary storage. The temperature of the chilled water prepared by the chiller is maintained between 20-25℃.

[0016] The cooling water tank of this invention adopts a modular structure design with a central main tank and two auxiliary tanks at both ends. The filter screen in the auxiliary tanks effectively intercepts impurities or foreign objects in the cooling water, keeping the cooling water in the main tank clean and reducing the risk of impurities adhering to the cable insulation layer. The multi-inlet design on the side wall of the main tank facilitates adjusting the water flow direction according to process needs, reducing temperature stratification, promoting cooling uniformity, and facilitating the circulation of cooling water, thus improving cooling water utilization. Furthermore, the reinforcing ribs on the outer wall of the tank significantly improve the structural rigidity and deformation resistance of the tank, solving the problem of easy deformation in traditional welded water tanks. The lifting lugs at the top of the tank greatly facilitate equipment installation, cable transfer, and daily maintenance and cleaning, improving the maintainability, flexibility, and service life of the equipment. The segmented tank cover with handles not only facilitates employee operations but also effectively prevents water mist from spreading into the workshop, contributing to environmental improvement and water conservation.

[0017] The rollers installed within the trough not only guide the cables, but their number and layout have also been optimized to help reduce cable vibration and deformation during cooling, ensuring the concentricity of the insulation layer. The design of the water baffle and the option to install a baffle plate increases the flexibility of process adjustment, allowing control of water level and overflow according to different cable speeds and cooling requirements, further improving cooling efficiency and reducing water splashing and consumption. This design takes into account the varying needs of producing cables of different specifications, enhancing the adaptability and versatility of the equipment.

[0018] Each cold water pipe outlet is equipped with a flow divider, with an opening at the bottom and several spray holes on both sides. The flow divider design transforms the large-diameter columnar water jet from the original outlet into several horizontal small-diameter water jets and a vertically downward small waterfall flow, uniformly spraying cold water into the cooling water tank to cool the cable surface. This results in good cooling uniformity and minimal cable bending deformation. At the same time, the excellent cooling uniformity of the water tank also indirectly improves the conductivity and mechanical properties of the metal cable core, ensuring high uniformity and stability of conductive transmission.

[0019] A guide wheel assembly is installed in the sub-groove at the far end of the extrusion outlet. The guide wheels of the guide wheel assembly are mounted on the front end of the mounting block via axles. A limiting block is installed on the side of the mounting block. The rear end of the mounting block is connected to the side wall of the sub-groove via a compression spring, which is fixed by a lock nut. The guide wheel assembly design in the sub-groove ensures that the cable insulation layer is aligned with the central axis of the cooling water tank after cooling is complete, further improving the straightness of the cable, reducing its deformation and bending due to uneven cooling, and facilitating subsequent drying and winding processes. The guide wheel assembly is connected to the side wall of the sub-groove via a compression spring. The restoring force of the compression spring is converted into a centering and corrective force for the cable, and it can adapt to the guidance of different cable diameters.

[0020] The cold water tank has a liquid level observation window on one side for easy real-time monitoring of the liquid level; there is a window on the top covered by the cold water tank cover for easy cleaning of the inside of the cold water tank; and a cold water tank inlet is located on the other side.

[0021] Several air pipes are installed behind the cooling water tank, all facing the cable and the cooling water tank. This design is used to quickly blow the moisture adhering to the surface of the cooled cable into the water tank, which saves water resources and keeps the cable surface and the workshop floor dry at the same time.

[0022] This invention organically combines multiple objectives, such as controlling uneven cable cooling and bending deformation, achieving efficient and uniform cooling, and strengthening equipment structure while facilitating maintenance. Compared to existing technologies, it demonstrates greater systematicity and practicality. It not only helps improve the final quality of cable products (such as insulation uniformity, mechanical strength, and insulation performance), but also enhances the safety of the production environment and reduces equipment maintenance costs. This aligns with the trend of modern cable manufacturing towards green, efficient, and high-quality development, and possesses promising prospects for industrial application.

[0023] Advantages of this invention: 1. This invention can monitor the position of the cable in the cooling water tank in real time using an underwater high-frequency ultrasonic ranging sensor, and associate the position with the cold water spray system via PLC; by controlling the intensity of the cold water spray, it can achieve non-contact, fully automatic modification of the cable's bending deformation, resulting in cables with small bending deformation, high straightness accuracy, and applicability to the production of cables of different specifications, with a wide range of applications.

[0024] 2. According to the different degrees of cable bending, the cold water proportional valve is designed with several opening degrees to match the cable bending situation, so as to make the cable bending adjustment more flexible and avoid the cable being overcorrected.

[0025] 3. By changing the temperature to adjust the way the cable bends, this invention can completely eliminate the internal stress of the cable. The bent part of the cable will not spring back, which is beneficial to the subsequent cable reeling process. At the same time, the excellent insulation layer can reduce electromagnetic interference and power leakage, ensure transmission safety, and has strong environmental adaptability, high durability and long service life.

[0026] 4. The excellent cooling uniformity of the water tank in this invention will also indirectly improve the conductivity and mechanical properties of the metal cable core, ensuring high uniformity and stability of conductive transmission.

[0027] 5. The design of the cooling water tank baffle and the option to install a baffle plate in this invention increases the flexibility of process adjustment. It allows for control of water level and overflow according to different cable speeds and cooling requirements, further improving cooling efficiency and reducing water splashing and consumption. This design takes into account the changing needs during the production of cables of different specifications, enhancing the adaptability and versatility of the device. Attached Figure Description

[0028] Figure 1 The facade structure of this invention Figure 1 ; Figure 2 The facade structure of the present invention Figure 2 ; Figure 3 This is the front view of the present invention; Figure 4 This is a top view of the present invention; Figure 5 for Figure 4 Enlarged structural diagram at point I; Figure 6 This is an elevation view of the cooling water tank and some of its components according to the present invention. Figure 7 This is a top view of the cooling water tank and some components of the present invention; Figure 8 This is a schematic diagram illustrating the principle of controlling cable bending in Embodiment 1 of the present invention; Figure 9 This is a schematic diagram illustrating the principle of controlling cable bending in Embodiment 2 of the present invention; Figure 10 This is a schematic diagram illustrating the principle of controlling cable bending in Embodiment 3 of the present invention; The numbers and component names in the diagram are as follows: 1-Extruder; 2-Cooling water tank; 21-Roller; 22-Filter screen; 23-Cooling water tank inlet; 24-Cooling water tank outlet; 26-Baffle plate; 27-Lifting lug; 28-Reinforcing rib; 29-Tank cover; 291-Handle; 210-Support base; 211-Distance sensor; 212-Cold water pipe; 2121-Diverter cover; 213-Cold water pump; 214-Cold water tank; 2141-Liquid level observation window; 2142-Cold water tank cover; 2143-Cold water tank inlet; 2144-Cold water tank outlet; 3-Guide wheel assembly; 31-Guide wheel; 32-Mounting block; 33-Limit block; 34-Compression spring; 35-Locking nut; 4-Air pipe; 5-Cable. Detailed Implementation

[0029] To provide a more detailed description of the present invention, the following description is based on embodiments 1-3 and the accompanying drawings.

[0030] Example 1

[0031] As attached Figures 1-4 As shown, a cooling device and method for controlling the bending degree of cable insulation layer extrusion molding is disclosed. The extruded cable 5 is cooled down by passing through a cooling water tank 2. Several underwater distance sensors 211 are arranged in an array on both sides of the cooling water tank 2 to monitor the distance between the sensor and the cable 5 in real time. At the same time, cold water pipes 212 are also arranged on both sides of the cooling water tank 2. Cold water is sprayed onto the cable 5 through the pipe openings. The distance signal between the sensor and the cable 5 is detected by the distance sensor 211 to determine whether the cable is bent. Then, the proportional valve of the water inlet pipe is controlled to introduce cold water to force cooling one side of the cable 5, thereby changing the bending degree of the cable 5.

[0032] The control method includes the following steps: The distances L measured by the range sensor array are L1, L2, L3, L4 and L5, L6, L7, L8 in the order of the extrusion direction, with a manually set threshold a. Case (1): When L1 < L2 < L3 < L4 and |L1-L4|≥a are satisfied simultaneously, the proportional valve of the inlet pipe on this side is opened and the proportional valve of the inlet pipe on the opposite side is closed, and the surface of the cooling cable is connected to the cold water. At this time, the ranging sensor array on the other side should satisfy: L5 > L6 > L7 > L8, and |L5-L8|≥a as the verification of the detection. Case (2): When L1 > L2 > L3 > L4 and |L1-L4|≥a are satisfied simultaneously, the proportional valve of the inlet pipe on this side is closed and the proportional valve of the inlet pipe on the opposite side is opened, and the surface of the cooling cable is supplied with cold water on the opposite side; at this time, the ranging sensor array on the other side should satisfy: L5 < L6 < L7 < L8, and |L5-L8|≥a as the verification of the detection; Case (3): When |L1-L4|≤a, the proportional valves of the water inlet pipes on both sides are closed and not started; at this time, the ranging sensor array on the other side should satisfy: |L5-L8|≤a as a verification of the detection.

[0033] When 2a≥|L1-L4|>a, the opening degree of the inlet proportional valve is 30%; when 3a≥|L1-L4|>2a, the opening degree of the inlet proportional valve is 70%; when |L1-L4|>3a, the opening degree of the inlet proportional valve is 100%.

[0034] The ranging sensor 211 and the water inlet proportional valve are both connected to the PLC signal.

[0035] The ranging sensor 211 is an underwater ultrasonic sensor.

[0036] As attached Figures 5-7 As shown, the cooling water tank 2 consists of a main tank in the middle and auxiliary tanks at both ends. Several support seats 210 are provided at the bottom. Several support rollers 21 are provided in both the main tank and the auxiliary tanks. A filter screen 22 is provided at the bottom of the auxiliary tanks. The bottoms of the main tank and the auxiliary tanks are connected to the cooling water tank outlet 24. The cooling water tank inlet 23 is located on both sides of the main tank at the far end of the extrusion. A distance sensor 211 and a cold water pipe 212 are located on the side wall near the extrusion end of the main tank. The cold water pipe 212 is connected to one end of a cold water pump 213, and the other end of the cold water pump 213 is connected to the cold water tank outlet 2144 of the cold water tank 214 below the cooling water tank 2. Water baffles 26 are movably inserted at both ends of the main tank, with the height of the water baffle 26 at the inlet end being lower than that at the outlet end. Several lifting lugs 27 and a tank cover 29 are provided at the upper end of the cooling water tank 2, and handles 291 are provided on the tank cover 29. Several reinforcing ribs 28 are provided on the outer side wall of the cooling water tank 2.

[0037] A guide wheel assembly 3 is provided in the sub-groove at the far end of the extrusion outlet. The guide wheel 31 of the guide wheel assembly 3 is mounted on the front end of the mounting block 32 via a wheel axle. The limiting block 33 is mounted on the side of the mounting block 32. The rear end of the mounting block 32 is connected to the side wall of the sub-groove via a compression spring 34. The compression spring 34 is fixed by a locking nut 35.

[0038] Each cold water pipe 212 outlet is provided with a flow divider 2121, which has an opening at the bottom and several through holes on both sides.

[0039] The cold water tank 214 below the cooling water tank 2 has a liquid level observation window 2141 on one side, a window on the top covered by the cold water tank cover 2142, and a cold water tank inlet 2143 on the other side.

[0040] Several air pipes 4 are provided behind the cooling water tank 2, and all air pipes 4 are directed toward the cable 5 and the cooling water tank 2.

[0041] As attached Figure 8 As shown, in Example 1, the extruder preheating temperature was 100±10℃, the extrusion speed was 7m / min, the extruder screw speed was 25r / min, and the distances L measured by the distance sensor array in the extrusion direction were L1=158.7mm, L2=165.2mm, L3=186.0mm, L4=221.4mm and L5=159.3mm, L6=152.8mm, L7=132mm, L8=96.6mm; the manually set threshold a=20mm; Based on the judgment, L1 < L2 < L3 < L4, and |L1-L4| = 62.7mm ≥ 20mm; L5 > L6 > L7 > L8, and |L5-L8| = 62.7mm ≥ 20mm, satisfying the above condition (1), it indicates that the cable bends to the opposite side, so the proportional valve of the water inlet pipe on that side is open and the proportional valve of the water inlet pipe on the opposite side is closed, and cold water is introduced into the surface of the cable for cooling. At the same time, since |L1-L4| = 62.7mm > 3a, the opening degree of the proportional valve of the water inlet pipe is 100%.

[0042] Example 2

[0043] Example 2 is the same as Example 1 except for the bending deformation.

[0044] As attached Figure 9 As shown, in Example 2, the distances L measured by the ranging sensor array in the extrusion direction are L1=160.6mm, L2=156.0mm, L3=148.8mm, L4=121.4mm and L5=157.4mm, L6=162mm, L7=169.2mm, L8=196.6mm; the manually set threshold a=20mm; Based on the judgment, L1 > L2 > L3 > L4, and |L1-L4| = 39.2mm ≥ 20mm; L5 < L6 < L7 < L8, and |L5-L8| = 39.2mm ≥ 20mm, which satisfies condition (2) in Example 1. This indicates that when the cable bends to that side, the proportional valve of the water inlet pipe on that side is closed, and the proportional valve of the water inlet pipe on the opposite side is opened, allowing cold water to enter the surface of the cable on the opposite side for cooling. At the same time, since 2a ≥ |L1-L4| = 39.2mm > a, the opening degree of the proportional valve of the water inlet pipe is 30%.

[0045] Example 3

[0046] Example 3 is the same as Example 1 and Example 2 except for the bending deformation.

[0047] As attached Figure 10As shown, in Example 3, the distances L measured by the ranging sensor array in the extrusion direction are L1=161.0mm, L2=159.3mm, L3=160.2mm, L4=162.5mm and L5=157mm, L6=158.7mm, L7=157.8mm, L8=155.5mm; the manually set threshold a=20mm; Calculations show that the distances L1-L4 and L5-L8 measured in Example 3 do not meet the above conditions (1) and (2), but |L1-L4|=1.5mm≤20mm and |L5-L8|=1.5mm≤20mm meet the condition (3) in Example 1, indicating that the bending degree of the cable is within the allowable tolerance range. Therefore, the proportional valves of the water inlet pipes on both sides are closed and not started.

Claims

1. A method for controlling the curvature of cable insulation layer during extrusion molding, characterized in that, The method is as follows: the extruded cable (5) is cooled down by passing through the cooling water tank (2). Several underwater distance sensors (211) are set on both sides of the cooling water tank (2) to form an array to monitor the distance between them and the cable (5) in real time. At the same time, cold water pipes (212) are also set on both sides of the cooling water tank (2). The pipe openings are aimed at the cable (5) and spray water. The distance signal between them and the cable (5) is detected by the distance sensor (211) to determine whether the cable is bent. Then, the proportional valve of the water inlet pipe is controlled to enter cold water to force cooling one side of the cable (5) to change the bending degree of the cable (5).

2. The method for controlling the curvature of cable insulation layer by extrusion molding according to claim 1, characterized in that: The control method includes the following steps: The distances L measured by the range sensor array are L1, L2, L3, L4 and L5, L6, L7, L8 in the order of the extrusion direction, with a manually set threshold a. Case (1): When L1 < L2 < L3 < L4 and |L1-L4|≥a are satisfied simultaneously, the proportional valve of the inlet pipe on this side is opened and the proportional valve of the inlet pipe on the opposite side is closed, and the surface of the cooling cable is connected to the cold water. At this time, the ranging sensor array on the other side should satisfy: L5 > L6 > L7 > L8, and |L5-L8|≥a as the verification of the detection. Case (2): When L1 > L2 > L3 > L4 and |L1-L4|≥a are satisfied simultaneously, the proportional valve of the inlet pipe on this side is closed and the proportional valve of the inlet pipe on the opposite side is opened, and the surface of the cooling cable is supplied with cold water on the opposite side; at this time, the ranging sensor array on the other side should satisfy: L5 < L6 < L7 < L8, and |L5-L8|≥a as the verification of the detection; Case (3): When |L1-L4|≤a, the proportional valves of the water inlet pipes on both sides are closed and not started; at this time, the ranging sensor array on the other side should satisfy: |L5-L8|≤a as a verification of the detection.

3. The method for controlling the curvature of cable insulation layer by extrusion molding according to claim 2, characterized in that: When 2a≥|L1-L4|>a, the opening degree of the inlet proportional valve is 30%; when 3a≥|L1-L4|>2a, the opening degree of the inlet proportional valve is 70%; when |L1-L4|>3a, the opening degree of the inlet proportional valve is 100%.

4. The method for controlling the curvature of cable insulation layer by extrusion molding according to claim 1, characterized in that: The ranging sensor (211) and the water inlet proportional valve are both connected to the PLC signal.

5. The method for controlling the curvature of cable insulation layer by extrusion molding according to claim 1, characterized in that: The ranging sensor (211) is an underwater ultrasonic sensor.

6. The method for controlling the curvature of cable insulation layer by extrusion molding according to claim 1, characterized in that: The cooling water tank (2) consists of a main tank in the middle and auxiliary tanks at both ends. Several support seats (210) are provided at the bottom. Several support rollers (21) are provided in both the main tank and the auxiliary tanks. A filter screen (22) is provided at the bottom of the auxiliary tanks. The bottoms of the main tank and the auxiliary tanks are connected to the cooling water tank outlet (24). The cooling water tank inlet (23) is located on both sides of the main tank at the far end of the extrusion. The distance sensor (211) and the cold water pipe (212) are located on the side wall of the main tank at the near end of the extrusion. The cold water pipe (212) is connected to the cold water pump (211). 13) One end is connected to the cold water pump (213), and the other end is connected to the cold water tank outlet (2144) of the cold water tank (214) below the cooling water tank (2); the two ends of the main tank are movably connected to baffles (26), wherein the height of the baffle (26) at the inlet end is lower than the height of the baffle (26) at the outlet end; the upper end of the cooling water tank (2) is provided with several lifting lugs (27) and the tank cover (29), and the tank cover (29) is provided with a handle (291); the outer wall of the cooling water tank (2) is provided with several reinforcing ribs (28).

7. The method for controlling the curvature of cable insulation layer by extrusion molding according to claim 1, characterized in that: A guide wheel assembly (3) is provided in the sub-groove at the far end of the extrusion outlet. The guide wheel (31) of the guide wheel assembly (3) is installed at the front end of the mounting block (32) through the wheel axle. The limiting block (33) is installed on the side of the mounting block (32). The rear end of the mounting block (32) is connected to the side wall of the sub-groove through the compression spring (34). The compression spring (34) is fixed by the locking nut (35).

8. The method for controlling the curvature of cable insulation layer by extrusion molding according to claim 1, characterized in that: Each of the cold water pipes (212) is provided with a flow divider (2121) at its outlet. The flow divider (2121) has an opening at the bottom and several through holes on both sides.

9. The method for controlling the curvature of cable insulation layer by extrusion molding according to claim 1, characterized in that: The cooling water tank (214) below the cooling water tank (2) has a liquid level observation window (2141) on one side, a window on the top covered by the cooling water tank cover (2142), and a cooling water tank inlet (2143) on the other side.

10. The method for controlling the curvature of cable insulation layer by extrusion molding according to claim 1, characterized in that: Several air pipes (4) are provided behind the cooling water tank (2), and the air pipes (4) are all facing the cable (5) and the cooling water tank (2).

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