A heat-resistant and insulating power cable and its manufacturing method

Abstract

The present invention discloses a heat-resistant insulating power cable and a preparation method thereof. The present invention relates to the technical field of insulating power cables and includes a centering mechanism fixedly installed on the outer surface of a wire core. A gap is provided between the outer surface of the wire core and the centering mechanism, and a heat-conducting insulating material is poured into the gap. For the heat-resistant insulating power cable and the preparation method thereof, a protective layer is formed by a heat-shrinkable tube, an outer sleeve tube and a silica gel filling layer, so that gas is not easily leaked. The spiral sheet embedded in the silica gel filling layer makes the cable not easily break. Compared with the armored cable, the spiral sheet makes the cable more bendable. A plurality of insulating mechanisms are sleeved on the surface of a longer wire core, and the distance of the cavity air flow channel is shortened, which makes the insulating gas inside the cavity air flow channel easier to control and adjust. By replacing the traditional flame-retardant coating, the problem that the flame-retardant effect of the flame-retardant material is poor during application due to toxic gas and dehydration reaction is solved.

Description

Technical Field

[0001] The invention relates to the technical field of insulated power cables, in particular to a heat-resistant insulated power cable and a preparation method thereof. Background Art

[0002] The flame retardant layer of traditional cables generally uses a single flame retardant material, which is a halogen flame retardant. When burned, it generates a large amount of smoke and toxic gases, and the amount increases with the increase of combustion temperature. Therefore, it can only be used for low-temperature flame retardancy. The halogen-free flame retardants used in recent years have less smoke and low toxicity, but contain a large amount of hydrated substances. When the temperature is high, the hydrated substances inside the cable will undergo a dehydration reaction, thereby reducing the physical and mechanical properties of the cable. Therefore, the flame retardant temperature cannot be high. Due to the use of a single flame retardant material, the cable either produces a large amount of toxic gases or reduces the cable performance due to dehydration reaction, thereby affecting the flame retardant temperature and flame retardant time of the cable. The Chinese patent announcement number is: CN110504059A, which discloses "A heat-resistant and aging-resistant cable insulation layer and cable thereof". In this patent, a heat-resistant component is added inside the rubber outer sheath. The heat can be directed to other areas inside the cable through the metal isolation net, and the heat radiation is radiated to the outside of the rubber outer sheath through the heat reflection layer to prevent heat from being transmitted to the inside of the rubber inner sheath. The insect-proof powder inside the insect-proof layer can remove insects, and the filling rubber overflowing from the filling layer can fill the damaged crack area of ​​the cable, so that the side surface of the cable remains sealed.

[0003] Existing heat-resistant insulated power cables and their preparation methods have structural design defects, the presence of toxic gases and dehydration reactions that result in poor flame retardant effects of flame retardant materials when used, and insufficient cable insulation performance that causes accelerated material aging and even breakdown and combustion. Summary of the invention

[0004] The present invention provides a heat-resistant insulated power cable and a preparation method thereof, which solves the problems mentioned in the above background technology.

[0005] To achieve the above object, the present invention is implemented by the following technical scheme: a heat-resistant insulated power cable, comprising a core, the core being composed of a copper strand and a cross-linked polyethylene tube, the number of the cores being three, and further comprising:

[0006] A centering mechanism, the centering mechanism is fixedly mounted on the outer surface of the wire core, a gap is provided between the outer surface of the wire core and the centering mechanism and is filled with heat-conducting insulating material, the centering mechanism is used for blocking, centering and limiting the three wire cores and for extracting the heat generated by the wire core;

[0007] Insulating mechanism, the insulating mechanism is fixedly installed on the outer surface of the centering mechanism, the surface of the insulating mechanism is fixedly connected with a threaded cylinder, the insulating mechanism is used for the introduction and discharge of insulating gas, and the surface of the insulating mechanism is fixedly connected with a heat shrinkable tube and an outer sleeve respectively;

[0008] Support mechanism, the support mechanism is fixedly installed at the middle position on the surface of the insulating mechanism, the support mechanism is used for forming an insulating air flow channel and the protective support of the wire core. If the temperature of the cable conductor is too high or the insulation of the cable is poor, it will cause the cable to burn. In this device, the three wire cores are separately placed into the inside of the centering mechanism, and the centering mechanism performs heat insulation and centering on the wire cores. The heat shrinkable tube is coated on the outer surface of the support mechanism, and a cavity air flow channel is formed between the heat shrinkable tube, the support mechanism and the centering mechanism. The insulating mechanism transports insulating gas into the inside of the air flow channel to realize the insulating protection of the cavity;

[0009] Overheat prevention mechanism, the overheat prevention mechanism is fixedly installed at a position close to the edge on the surface of the insulating mechanism, and the overheat prevention mechanism is used for the detection and adjustment of the gas temperature in the insulating air flow channel;

[0010] Among them, the support mechanism includes a plastic shell, a support groove is opened on the inner side surface of the plastic shell, a side hole is opened at a position close to the edge on the surface of the plastic shell, and a rubber ring is fixedly connected to the outer surface of the plastic shell.

[0011] Preferably, a gap is provided between the heat shrinkable tube and the outer sleeve and a spiral piece is sleeved, the inside of the gap is filled with silica gel filler, a second injection hole is opened on the surface of the outer sleeve, a cavity is arranged inside the shell, the first injection hole is used for filling the inside of the cavity with heat-conducting insulating paint. After the wire core passes through the insulating spring strip, the extension tube and the shell in sequence, the heat-conducting insulating paint is poured into the position between the extension tube and the heat-conducting tape through the shell, and the three wire cores are evenly arranged on the surface of the shell.

[0012] Preferably, the support mechanism further includes a plastic strip, the outer surface of the plastic strip is fixedly installed at a position close to the middle on the inner side surface of the plastic shell, a triangular plate is fixedly connected to the end surface of the plastic strip, the triangular plate is fixedly installed at a position close to the middle on the surface of the insulating mechanism, and a notch is opened on the surface of the rubber ring.

[0013] Preferably, the centering mechanism includes a shell, a through hole is opened at a position close to the edge on the surface of the shell, a first injection hole is opened at the middle position on the surface of the shell, and an extension tube is fixedly connected to a position close to the edge on the surface of the shell.

[0014] Preferably, the centering mechanism further includes an insulating spring strip. The end face of the insulating spring strip is fixedly connected and installed at the end face position of the extension pipe. The surface of the insulating spring strip is coated with a heat-conducting adhesive tape, which blocks multiple wire cores. The multiple heat-conducting adhesive tapes are blocked by an insulating gas. Sulfur hexafluoride is preferably selected as the insulating gas, effectively improving the overall insulation performance of the cable. A plurality of sealing shells are provided. An independent cavity air flow channel is formed at the position between every two sealing shells. The oppositely arranged sealing shells are used to adjust the gas inside the independent air flow channel. Under normal conditions, an exhaust pipe on one side introduces insulating gas into the interior of the sealing shell, and the insulating gas fills the cavity air flow channel to play an insulating role.

[0015] Preferably, the material of the insulating spring strip is polytetrafluoroethylene. The inner side of the heat-conducting adhesive tape is close to the outer surface of the wire core, and the extension pipe is arranged opposite to the position of the through hole.

[0016] Preferably, the insulating mechanism includes a sealing shell. A through hole is formed on the inner side surface of the sealing shell. The inner side surface of the sealing shell is fixedly connected to the surface of the extension pipe. A ring body is fixedly connected to the side surface position of the sealing shell. Plastic strips connect multiple plastic shells. The plastic strips and the plastic shells form a framework structure to support the insulating air flow channel. A pin passes through the ring body, the outer sleeve pipe, and the heat-shrinkable pipe. The pouring of the silicone coating makes the outer sleeve pipe and the outside of the cable firmly sealed. The support groove is used for the support and block of the wire core. The plastic shell with an inner hollow shell structure firmly supports the wire core. When the heat-shrinkable pipe shrinks, it is in close contact with the surface of the rubber ring.

[0017] Preferably, the insulating mechanism further includes a pin. The pin passes through the ring body, the outer sleeve pipe, and the heat-shrinkable pipe from outside to inside in sequence. A cavity is arranged inside the sealing shell.

[0018] Preferably, an exhaust pipe is fixedly connected to the top of the sealing shell, and an air flow pipe is fixedly connected to the surface of the sealing shell. The interior of the exhaust pipe, the cavity, and the air flow pipe are communicated.

[0019] Preferably, the overheat prevention mechanism includes a tensile force detector. The tensile force detector is fixedly installed at a position close to the edge on the surface of the sealing shell. The output end of the tensile force detector is fixedly connected to a telescopic spring. A connecting ring is fixedly connected to the end face position of the telescopic spring. An insulating air flow channel is formed between multiple plastic shells and the heat-shrinkable pipe. Under normal use conditions, insulating gas fills the interior of the air flow channel. The blockage of the insulating gas provides insulating protection between the wire cores. The heat-conducting adhesive tape and the heat-conducting coating reduce the temperature of the wire cores. The exhaust pipe is in a closed state. When the temperature of the conductor inside the wire core is too high, the temperature of the insulating gas becomes too high through heat transfer. In this state, it is still possible to cause the cable to burn.

[0020] Preferably, rigid bars and elastic bars are fixedly connected to the surface of the connecting ring respectively. There are multiple rigid bars, and metal sheets are fixedly connected between two adjacent rigid bars.

[0021] A preparation method of a heat-resistant and insulating power cable includes the following steps:

[0022] Step 1: Core manufacturing. At room temperature, a copper bar is drawn into copper wires, the copper wires are heated and kept warm, and then naturally cooled. The copper wires are stranded in a multi-strand single-wire stranding method to form a copper stranded wire. A traction machine is used to draw the copper stranded wire to be coated into the interior of an injection extrusion machine to coat cross-linked polyethylene, completing the preparation of the copper conductor core. Similarly, the preparation of three cores is completed;

[0023] Step 2: Centering structure forming. The housing passes through the sealing shell and is fixedly installed on the surface of the sealing shell. A heat-conducting tape is wrapped around the surface of the insulating spring strip. The cores are sequentially passed through the inner side of the heat-conducting tape coated thereon, and a heat-conducting and insulating coating is poured into the interior of the housing and the heat-conducting tape through the first injection hole and cooled and shaped;

[0024] Step 3: Skeleton structure forming. Plastics and rubber particles are put into an injection extrusion machine. The molten plastics are formed into a plastic shell through a die. Multiple plastic strips are sequentially passed through the plastic shell and fixedly joined by heat melting. Multiple plastic shells slide to the outer surface of the heat-conducting tape, and the inner side of the plastic shell is joined to the surface of the heat-conducting tape by heating and melting. The triangular plate is fixedly installed at a position near the middle on the surface of the sealing shell, and then a rubber ring is sleeved on the surface of the plastic shell;

[0025] Step 4: Heat-shrinkable coating forming. After a tensile force detector and a telescopic spring are fixedly installed on the surface of the sealing shell, the rigid bars and the elastic bars are sequentially passed through multiple plastic shells for fixation. A heat-shrinkable tube is sleeved on the surface of the rubber ring and heated. A spiral sheet and an outer sleeve are sequentially sleeved on the surface of the heat-shrinkable tube, and then silica gel filler is filled between the outer sleeve and the heat-shrinkable tube and shaped.

[0026] The present invention provides a heat-resistant and insulating power cable and a preparation method thereof. It has the following beneficial effects:

[0027] 1. For the heat-resistant and insulating power cable and its preparation method, the heat-shrinkable tube, the outer sleeve and the silica gel filling layer form a protective layer, making it difficult for gas to leak. The spiral sheet embedded in the silica gel filling layer makes the cable not easily break. Compared with armored cables, the spiral sheet makes the cable more bendable. Multiple insulating mechanisms are sleeved on the surface of a longer core, shortening the distance of the cavity air flow channel, making it easier to control and adjust the insulating gas inside the cavity air flow channel, replacing the traditional flame-retardant coating, and solving the problem that the flame-retardant effect of the flame-retardant material is poor due to toxic gases and dehydration reactions during application.

[0028] 2. The heat-resistant and insulating power cable and its manufacturing method. The housing isolates multiple wire cores, reducing the influence between the multiple wire cores. At the same time, the isolation of the insulating spring strips provides better protection for other wire cores when a single wire core breaks. The wire cores are tightly connected to the heat-conducting tape through a coating. In this device, the material of the insulating spring strips is preferably polytetrafluoroethylene, improving the overall flame-retardant and insulating performance of the cable. After the heat-conducting insulating coating cools and solidifies, a heat-conducting layer is formed between the heat-conducting insulating coating and the heat-conducting tape. The outer surface of the heat-conducting tape is inside the cavity air flow channel, and the heat of the wire cores can be quickly transferred to the gas to achieve the purpose of cooling.

[0029] 3. The heat-resistant and insulating power cable and its manufacturing method. After being used for a period of time, impurities mixed in the insulating gas will reduce its insulation performance. One air flow pipe is used to push the gas, and the other air flow pipe is used to discharge the gas, thereby driving the circulation of the gas inside the air flow channel, purifying the insulating gas inside the air flow channel, and preventing the insulation performance inside the heat-shrinkable tube from deteriorating. This solves the problem of accelerated material aging or even breakdown and combustion caused by insufficient insulation performance of the cable.

[0030] 4. The heat-resistant and insulating power cable and its manufacturing method. When the heat-shrinkable tube is bent, the cut makes the bending performance of the rubber ring better. Multiple plastic shells are evenly arranged inside the heat-shrinkable tube. When the heat-shrinkable tube is heated, the support of the plastic shells forms an air flow channel. Multiple edge holes are opened on the surface of the plastic shells. When the insulating gas is in a circulating and purifying state, the edge structure design of the edge holes makes it easier for the insulating gas to carry away the tiny impurities deposited on the inner wall of the heat-shrinkable tube when flowing, making the insulation performance of the air flow channel inside the heat-shrinkable tube better.

[0031] 5. The heat-resistant and insulating power cable and its manufacturing method. The metal sheet inside the air flow channel is heated and bent. Due to the rigid connection of the rigid strip, the telescopic spring is stretched. The tension detector detects the change in the tension of the telescopic spring. The exhaust pipe promotes the flow of the insulating gas. The driven circulation of the insulating gas quickly takes away the heat accumulated inside the air flow channel. After the temperature is reduced, the exhaust pipe is closed again. After the temperature of the insulating gas is reduced, its insulation performance is improved. The elastic recovery of the elastic strip makes the metal sheet pull flat, accurately positioning the overheated position of the cable and thus improving the cable cooling efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 is a flowchart of the manufacturing method of the heat-resistant and insulating power cable of the present invention;

[0033] Figure 2 is a three-dimensional view of the overall heat-resistant and insulating power cable of the present invention;

[0034] Figure 3 is a three-dimensional view of the inside of the heat-resistant and insulating power cable of the present invention;

[0035] Figure 4 This is a schematic structural diagram of the centering mechanism of the present invention as a whole;

[0036] Figure 5 This is a schematic structural diagram of a part of the centering mechanism of the present invention;

[0037] Figure 6 This is a schematic structural connection diagram of the support mechanism and the overheat prevention mechanism of the present invention;

[0038] Figure 7 This is a schematic structural diagram of the insulation mechanism of the present invention;

[0039] Figure 8 This is a schematic structural diagram of the support mechanism of the present invention;

[0040] Figure 9 This is a schematic structural diagram of the overheat prevention mechanism of the present invention;

[0041] Figure 10 This is a schematic structural connection diagram of the centering mechanism and the insulation mechanism of the present invention;

[0042] In the figure: 1, wire core; 2, centering mechanism; 21, housing; 22, through hole; 23, extension tube; 24, first injection hole; 25, insulating spring strip; 26, heat-conducting tape; 3, insulation mechanism; 31, sealing shell; 32, ring body; 33, pin; 34, drainage pipe; 35, air flow pipe; 4, threaded cylinder; 5, support mechanism; 51, triangular plate; 52, plastic strip; 53, plastic shell; 54, edge hole; 55, support groove; 56, rubber ring; 57, notch; 6, overheat prevention mechanism; 61, tension detector; 62, telescopic spring; 63, rigid strip; 64, metal sheet; 65, elastic strip; 71, heat-shrinkable tube; 72, spiral sheet; 73, outer sleeve; 74, second injection hole. Specific embodiments

[0043] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0044] First embodiment: As Figures 1 - 3 shown, the present invention provides a technical solution: a heat-resistant and insulating power cable, including a wire core 1, the wire core 1 is composed of a copper stranded wire and a cross-linked polyethylene tube, and the number of wire cores 1 is three. It also includes:

[0045] A centering mechanism 2 is fixedly mounted on the outer surface of the wire core 1. A gap is provided between the outer surface of the wire core 1 and the centering mechanism 2 and is filled with a heat-conducting insulating material. The centering mechanism 2 is used for the isolation, centering and limiting of the three wire cores 1 and the extraction of heat generated by the wire core 1.

[0046] The insulating mechanism 3 is fixedly mounted on the outer surface of the centering mechanism 2. The surface of the insulating mechanism 3 is fixedly connected with a threaded tube 4. The insulating mechanism 3 is used for introducing and discharging insulating gas. The surface of the insulating mechanism 3 is respectively fixedly connected with a heat shrink tube 71 and an outer sleeve 73;

[0047] Support mechanism 5, which is fixedly mounted at the middle of the surface of the insulating mechanism 3, and is used to form an insulating air flow channel and a protective support for the wire core 1;

[0048] The overheating prevention mechanism 6 is fixedly mounted on the surface of the insulating mechanism 3 near the edge, and is used for detecting and adjusting the gas temperature in the insulating gas flow channel;

[0049] A gap is provided between the heat shrink tube 71 and the outer sleeve 73 and a spiral sheet 72 is sleeved thereon. Silicone filler is poured into the gap. A second injection hole 74 is provided on the surface of the outer sleeve 73 .

[0050] During use, if the temperature of the cable conductor is too high or the insulation of the cable is poor, the cable may burn. In the device, three cores 1 are placed separately inside the centering mechanism 2, and the centering mechanism 2 insulates and centers the cores 1. The heat shrink tube 71 is coated on the outer surface of the supporting mechanism 5, and a cavity airflow channel is formed between the heat shrink tube 71, the supporting mechanism 5 and the centering mechanism 2. The insulating mechanism 3 transports the insulating gas to the inside of the airflow channel to achieve insulation protection of the cavity. The heat shrink tube 71, the outer sleeve 73 and the silicone filling layer form a protective layer to prevent the gas from leaking. The spiral sheet 72 embedded in the silicone filling layer prevents the cable from breaking. Compared with armor, the spiral sheet 72 makes the cable more bendable. Multiple insulating mechanisms 3 are mounted on the surface of the longer core 1, and the distance of the cavity airflow channel is shortened, which makes the insulating gas inside the cavity airflow channel easier to control and adjust, replacing the traditional flame retardant coating coating, and solving the problem that toxic gases and dehydration reactions make the flame retardant effect of flame retardant materials poor when used.

[0051] Second embodiment: Figures 1 - 6As shown, the centering mechanism 2 includes a housing 21. A through hole 22 is provided at a position near the edge on the surface of the housing 21. A first injection hole 24 is provided at the middle position on the surface of the housing 21. An extension tube 23 is fixedly connected to the position near the edge on the surface of the housing 21. The centering mechanism 2 further includes an insulating spring strip 25. The end face of the insulating spring strip 25 is fixedly connected and installed at the end face position of the extension tube 23. The surface of the insulating spring strip 25 is coated with a heat-conducting adhesive tape 26. The material of the insulating spring strip 25 is polytetrafluoroethylene. The inner side of the heat-conducting adhesive tape 26 is close to the outer surface of the wire core 1. The extension tube 23 and the through hole 22 are arranged opposite to each other.

[0052] During use, a cavity is provided inside the housing 21. The first injection hole 24 is used to fill the inside of the cavity with a heat-conducting insulating coating. After the wire core 1 passes through the insulating spring strip 25, the extension tube 23 and the housing 21 in sequence, the heat-conducting insulating coating is poured into the position between the extension tube 23 and the heat-conducting adhesive tape 26 through the housing 21. The three wire cores 1 are evenly arranged on the surface of the housing 21. The housing 21 blocks the multiple wire cores 1, reducing the influence between the multiple wire cores 1. At the same time, the blocking of the insulating spring strip 25 provides better protection for other wire cores 1 when a single wire core 1 breaks. The wire core 1 is tightly connected to the heat-conducting adhesive tape 26 through the coating. In this device, the material of the insulating spring strip 25 is preferably polytetrafluoroethylene, improving the flame-retardant insulation performance of the overall cable. After the heat-conducting insulating coating cools and solidifies, a heat-conducting layer is formed between the heat-conducting insulating coating and the heat-conducting adhesive tape 26. The outer surface of the heat-conducting adhesive tape 26 is inside the cavity air flow channel, and the heat of the wire core 1 can be quickly transferred to the gas to achieve the purpose of cooling.

[0053] Third embodiment: As Figure 6 , Figure 7 shown, the insulating mechanism 3 includes a sealing shell 31. A through hole is provided on the inner side surface of the sealing shell 31. The inner side surface of the sealing shell 31 is fixedly connected to the surface of the extension tube 23. A ring body 32 is fixedly connected to the side position on the surface of the sealing shell 31. The insulating mechanism 3 further includes a pin 33. The pin 33 passes through the ring body 32, the outer sleeve 73 and the heat-shrinkable tube 71 from outside to inside in sequence. A cavity is provided inside the sealing shell 31. A drain pipe 34 is fixedly connected to the top of the sealing shell 31. An air flow pipe 35 is fixedly connected to the surface of the sealing shell 31. The drain pipe 34, the cavity and the inside of the air flow pipe 35 are communicated.

[0054] During use, the thermal conductive tape 26 blocks multiple wire cores 1, and the multiple thermal conductive tapes 26 are blocked by an insulating gas. Sulfur hexafluoride is preferably selected as the insulating gas, effectively improving the overall insulation performance of the cable. A plurality of sealing shells 31 are provided, and an independent cavity air flow channel is formed at the position between every two sealing shells 31. The oppositely arranged sealing shells 31 are used to adjust the gas inside the independent air flow channel. Under normal conditions, the exhaust pipe 34 on one side introduces the insulating gas into the inside of the sealing shell 31, and the insulating gas fills the cavity air flow channel to play an insulating role. After using for a period of time, impurities mixed in the insulating gas will reduce its insulation performance. The air flow pipe 35 on one side is used to push the gas, and the air flow pipe 35 on the other side is used to discharge the gas, thereby driving the circulation of the gas inside the air flow channel, so that the insulating gas inside the air flow channel is purified and the insulation performance inside the heat shrinkable tube 71 will not decline, solving the problem that the aging of materials is accelerated or even the cable is punctured and burned due to insufficient insulation performance of the cable.

[0055] Fourth Embodiment: As Figure 6 , Figure 8 shown, the support mechanism 5 includes a plastic shell 53. A support groove 55 is formed on the inner side surface of the plastic shell 53, and an edge hole 54 is formed on the surface of the plastic shell 53 near the edge. A rubber ring 56 is fixedly connected to the outer surface of the plastic shell 53. The support mechanism 5 further includes a plastic strip 52. The outer surface of the plastic strip 52 is fixedly installed at a position near the middle of the inner side surface of the plastic shell 53. A triangular plate 51 is fixedly connected to the end surface of the plastic strip 52, and the triangular plate 51 is fixedly installed at a position near the middle of the surface of the insulating mechanism 3. A notch 57 is formed on the surface of the rubber ring 56.

[0056] During use, the plastic strip 52 makes multiple plastic shells 53 connected to each other. The plastic strip 52 and the plastic shell 53 form a framework structure to support the insulating air flow channel. The pin 33 penetrates and connects the ring body 32, the outer sleeve 73 and the heat shrinkable tube 71. The pouring of the silicone coating makes the outer sleeve 73 and the outside of the cable firmly sealed. The support groove 55 is used for supporting and blocking the wire core 1. The plastic shell 53 with an inner hollow shell structure firmly supports the wire core 1. When the heat shrinkable tube 71 shrinks, it is in close contact with the surface of the rubber ring 56. When the heat shrinkable tube 71 is bent, the notch 57 makes the bending performance of the rubber ring 56 better. Multiple plastic shells 53 are evenly arranged inside the heat shrinkable tube 71. When the heat shrinkable tube 71 is heated, the support of the plastic shell 53 forms an air flow channel. A plurality of edge holes 54 are formed on the surface of the plastic shell 53. When the insulating gas is in a circulating flow and purification state, the edge structure design of the edge holes 54 makes it easier for the insulating gas to carry away the tiny impurities deposited on the inner wall of the heat shrinkable tube 71 when flowing, making the insulation performance of the air flow channel inside the heat shrinkable tube 71 better.

[0057] Fifth Embodiment: As Figure 6 , Figure 9 ,Figure 10 As shown in the figure, the overheat prevention mechanism 6 includes a tensile force detector 61, which is fixedly installed at a position near the edge of the surface of the sealing shell 31. The output end of the tensile force detector 61 is fixedly connected with a telescopic spring 62. A connecting ring is fixedly connected to the end face position of the telescopic spring 62. A rigid strip 63 and an elastic strip 65 are respectively fixedly connected to the surface of the connecting ring. The number of the rigid strips 63 is multiple, and a metal sheet 64 is fixedly connected between two rigid strips 63.

[0058] During use, an insulating air flow channel is formed between multiple plastic shells 53 and the heat shrinkable tube 71. In the normal use state, insulating gas fills the inside of the air flow channel. The insulation of the insulating gas protects the wire cores 1 from each other. The heat-conducting tape 26 and the heat-conducting paint reduce the temperature of the wire cores 1. The exhaust suction pipe 34 is in a closed state. When the temperature of the conductor inside the wire core 1 is too high, the temperature of the insulating gas becomes too high through heat transfer. In this state, it is still possible to cause the cable to burn. In this device, the metal sheet 64 inside the air flow channel is heated and bent. Due to the rigid connection of the rigid strips 63, the telescopic spring 62 is stretched. The tensile force detector 61 detects the change in the tensile force of the telescopic spring 62. The exhaust suction pipe 34 promotes the flow of the insulating gas. The insulating gas is driven to circulate, so that the heat accumulated inside the air flow channel is quickly carried away. After the temperature is reduced, the exhaust suction pipe 34 is in a closed state again. After the temperature of the insulating gas is reduced, its insulation performance is improved. The elastic recovery of the elastic strip 65 causes the metal sheet 64 to be pulled flat, accurately positioning the overheated position of the cable, thereby improving the cable cooling efficiency.

[0059] Sixth Embodiment: As Figures 1 - 10 shown, a preparation method of a heat-resistant insulating power cable includes the following steps:

[0060] Step 1: Core manufacturing. At room temperature, a copper bar is drawn into a copper wire, the copper wire is heated and kept warm, and then the copper wire is naturally cooled. The copper wire is stranded by using a multi-strand single-wire stranding method to form a copper stranded wire. A traction machine is used to traction the copper stranded wire to be coated into the internal coating cross-linked polyethylene of an injection extrusion machine to complete the preparation of the copper conductor core 1. Similarly, the preparation of three cores 1 is completed;

[0061] Step 2: Centering structure forming. The housing 21 passes through the sealing shell 31 and is fixedly installed on the surface of the sealing shell 31. The surface of the insulating spring strip 25 is coated and wound with a heat-conducting tape 26. The wire cores 1 are sequentially passed through the inner side of the coated heat-conducting tape 26. The heat-conducting insulating paint is poured into the housing 21 and the heat-conducting tape 26 through the first injection hole 24 and cooled and shaped;

[0062] Step 3. Forming the skeleton structure: Put plastic and rubber particles into an injection extrusion machine. The molten plastic is formed into a plastic shell 53 through a die. A plurality of plastic strips 52 sequentially pass through the plastic shell 53 and are fixedly joined by heat melting. A plurality of plastic shells 53 slide to the outer surface of the heat-conducting tape 26, and the inner side surface of the plastic shell 53 is joined to the surface of the heat-conducting tape 26 by heating and melting. The triangular plate 51 is fixedly installed at a position near the middle on the surface of the sealing shell 31. Subsequently, a rubber ring 56 is sleeved on the surface of the plastic shell 53;

[0063] Step 4. Heat-shrinkable coating forming: After fixedly installing the tensile force detector 61 and the telescopic spring 62 on the surface of the sealing shell 31, the rigid strip 63 and the elastic strip 65 are sequentially passed through a plurality of plastic shells 53 for fixation. A heat-shrinkable tube 71 is sleeved on the surface of the rubber ring 56 and heated. The spiral fin 72 and the outer sleeve 73 are sequentially sleeved on the surface of the heat-shrinkable tube 71. Subsequently, silica gel filler is filled between the outer sleeve 73 and the heat-shrinkable tube 71 and shaped.

[0064] It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device. Without further limitation. An element defined by the statement "comprising an..." does not exclude the existence of additional identical elements in the process, method, article or device comprising the element.

Claims

1. A heat-resistant insulated power cable, comprising a core (1), characterized in that: The wire core (1) is composed of a copper stranded wire and a cross-linked polyethylene tube. The number of the wire cores (1) is three, and the wire cores (1) further include: A centering mechanism (2), the centering mechanism (2) being fixedly mounted on the outer surface of the wire core (1), a gap being provided between the outer surface of the wire core (1) and the centering mechanism (2) and being filled with a heat-conducting insulating material, the centering mechanism (2) being used for blocking, centering and limiting the three wire cores (1) and for conducting heat generated by the wire core (1); An insulating mechanism (3), the insulating mechanism (3) being fixedly mounted on the outer surface of the centering mechanism (2), the surface of the insulating mechanism (3) being fixedly connected to a threaded tube (4), the insulating mechanism (3) being used for introducing and discharging insulating gas, the surface of the insulating mechanism (3) being fixedly connected to a heat shrink tube (71) and an outer sleeve (73); A support mechanism (5), the support mechanism (5) being fixedly mounted at a middle position of the surface of the insulating mechanism (3), the support mechanism (5) being used to form an insulating air flow channel and protective support for the wire core (1); An anti-overheating mechanism (6), the anti-overheating mechanism (6) being fixedly mounted on a surface of the insulating mechanism (3) at a position close to an edge, the anti-overheating mechanism (6) being used for detecting and adjusting the temperature of gas in the insulating gas flow channel; The support mechanism (5) comprises a plastic shell (53), the inner side surface of the plastic shell (53) is provided with a support groove (55), the surface of the plastic shell (53) is provided with an edge hole (54) near the edge, and the outer surface of the plastic shell (53) is fixedly connected with a rubber ring (56).

2. A heat-resistant insulated power cable according to claim 1, characterized in that: A gap is provided between the heat shrink tube (71) and the outer sleeve (73) and is sleeved with a spiral sheet (72); a silicone filler is poured into the gap; and a second injection hole (74) is provided on the surface of the outer sleeve (73).

3. A heat-resistant insulated power cable according to claim 2, characterized in that: The support mechanism (5) further comprises a plastic strip (52), the outer surface of the plastic strip (52) being fixedly mounted on the inner side surface of the plastic shell (53) near the middle, the end surface of the plastic strip (52) being fixedly connected to a triangular plate (51), the triangular plate (51) being fixedly mounted on the surface of the insulating mechanism (3) near the middle, and a notch (57) being provided on the surface of the rubber ring (56).

4. A heat-resistant insulated power cable according to claim 3, characterized in that: The centering mechanism (2) comprises a shell (21), a through hole (22) is provided on the surface of the shell (21) near the edge, a first injection hole (24) is provided in the middle of the surface of the shell (21), and an extension tube (23) is fixedly connected to the surface of the shell (21) near the edge.

5. A heat-resistant insulated power cable according to claim 4, characterized in that: The centering mechanism (2) further comprises an insulating spring strip (25), the end face of the insulating spring strip (25) being fixedly connected and mounted at the end face position of the extension tube (23), and the surface of the insulating spring strip (25) being coated with a heat-conducting adhesive tape (26).

6. A heat-resistant insulated power cable according to claim 5, characterized in that: The insulating spring strip (25) is made of polytetrafluoroethylene, the inner side surface of the thermal conductive tape (26) is close to the outer surface of the wire core (1), and the extension tube (23) and the through hole (22) are arranged relative to each other.

7. A heat-resistant insulated power cable according to claim 6, characterized in that: The insulating mechanism (3) comprises a sealing shell (31), the inner side surface of the sealing shell (31) being provided with a through hole, the inner side surface of the sealing shell (31) being fixedly connected to the surface of the extension tube (23), and a ring body (32) being fixedly connected to the side surface of the sealing shell (31).

8. A heat-resistant insulated power cable according to claim 7, characterized in that: The overheating prevention mechanism (6) comprises a tension detector (61), the tension detector (61) being fixedly mounted on a surface of the sealing shell (31) at a position close to an edge, the output end of the tension detector (61) being fixedly connected to a telescopic spring (62), and the end surface of the telescopic spring (62) being fixedly connected to a connecting ring.

9. A heat-resistant insulated power cable according to claim 8, characterized in that: A rigid strip (63) and an elastic strip (65) are respectively fixedly connected to the surface of the connection ring, there are a plurality of rigid strips (63), and a metal sheet (64) is fixedly connected at a position between two rigid strips (63).

10. A method for preparing a heat-resistant insulated power cable, comprising the following steps: Step 1, manufacturing the wire core, at room temperature, drawing a copper rod into a copper wire, heating and keeping the copper wire warm, and then naturally cooling the copper wire, twisting the copper wire by twisting multiple single wires to form a copper stranded wire, using a traction machine to pull the copper stranded wire to be coated inside an injection molding extruder for coating with cross-linked polyethylene, thereby completing the preparation of the copper conductor wire core (1), and similarly completing the preparation of the three wire cores (1); Step 2: forming the centering structure, the shell (21) passes through the sealing shell (31) and is fixedly mounted on the surface of the sealing shell (31), the surface of the insulating spring strip (25) is coated with a thermal conductive tape (26), the wire core (1) is sequentially passed through the inner side of the coated thermal conductive tape (26), and the thermal conductive insulating coating is poured into the shell (21) and the thermal conductive tape (26) through the first injection hole (24) and cooled to shape; Step 3, forming the skeleton structure, putting plastic and rubber particles into an injection molding extruder, hot-melt plastic is formed into a plastic shell (53) through a die, a plurality of plastic strips (52) pass through the plastic shell (53) in sequence and are fixedly joined by hot melting, a plurality of plastic shells (53) slide to the outer surface of the thermal conductive tape (26), the inner side surface of the plastic shell (53) is joined to the surface of the thermal conductive tape (26) by heating and melting, the triangular plate (51) is fixedly installed on the surface of the sealing shell (31) near the middle, and then the rubber ring (56) is sleeved on the surface of the plastic shell (53); Step 4: Heat shrink wrapping and forming. After the tension detector (61) and the telescopic spring (62) are fixedly mounted on the surface of the sealing shell (31), the rigid strip (63) and the elastic strip (65) are sequentially passed through the plurality of plastic shells (53) for fixing. The heat shrink tube (71) is sleeved on the surface of the rubber ring (56) and heated. The spiral sheet (72) and the outer sleeve (73) are sequentially sleeved on the surface of the heat shrink tube (71). Subsequently, silicone filler is filled between the outer sleeve (73) and the heat shrink tube (71) and the shaping is performed.

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