Prefabricated fusion stress cone and manufacturing method

Abstract

The present invention relates to high-voltage power cable connection accessories, and discloses a prefabricated fused stress cone and a manufacturing method thereof. It can be prefabricated in advance, can be crosslinked with the cable to form an integral body, effectively eliminates the micro-air gaps between the stress cone and the insulating layer of the cable and prevents polarization, and effectively improves the electrical performance stability and power transmission safety during cable power transmission. The present invention includes the following steps: manufacturing a stress cone insulator, which is made of non-crosslinked polyethylene raw material, the two ends of the stress cone insulator extend outward along the axis direction of the stress cone insulator, and the outer wall of the stress cone insulator is provided with a conical stress coating part; manufacturing a fused stress cone, coating a semiconductive raw material on the stress coating part to form a stress control body, and after solidification, the stress control body and the stress cone insulator form an integral structure of the fused stress cone.

Description

Technical Field

[0001] The present invention relates to high-voltage power cable connection accessories, in particular to a prefabricated fused stress cone and a manufacturing method thereof. Background Art

[0002] A high-voltage power cable is a power device used for high-voltage electric energy transmission, and is mostly applied to long-distance and large-length power transmission and distribution. In the actual application of high-voltage cables, the electric field is concentrated at the cable terminal position. The uniform distribution of this electric field and the realization of stable electrical performance are completed by the cable terminal stress cone. Therefore, an accessory - a cable terminal pluggable connector is required at the high-voltage cable terminal, which can make the electric field constant, dispersed and homogenized, so that the concentrated field strength can be restored to the normal electrical operation state.

[0003] Currently, the pluggable connectors of cable terminals generally adopt a rubber prefabricated design. This design utilizes the excellent elasticity of the rubber stress cone to enable it to closely fit on the insulating layer of the cable. However, since the cable generates heat during long-term continuous current-carrying operation, this thermal effect will cause the insulating layer of the cable to gradually soften. With the continuous holding action of the rubber stress cone on the cable, the diameter of the cable insulating layer will shrink, and at the same time, the interface pressure between the rubber and the insulating layer will also be correspondingly weakened; at the same time, the microscopic interface between the stress cone insulation and the cable insulation is polarized under the action of high electric field strength and thermal field, ultimately resulting in a decrease in the maximum breakdown electric field strength that the cable can withstand.

[0004] In the existing cable pluggable connector structure, during the long-term operation of the cable, the stress cone insulation and the cable insulation are in a high-field sensitive area of a movable interface. This interface is affected by the dual action of the electric field and the thermal field. This action causes polarization of the tiny air gaps between the stress cone and the cable inside the connector and the trace moisture and impurities on the interface. The polarization effect will cause distortion of the interface electric field between the stress cone and the cable insulating layer in the high electric field strength area, thereby increasing the risk of surface discharge and leading to breakdown of the insulating layer. Moreover, the pluggable connector of the cable terminal needs to be prefabricated in advance, which should be convenient for transportation and storage, and can be directly and quickly fused with the high-voltage cable terminal on site to completely eliminate the electrical hidden dangers of the micro-air gap interface. Summary of the Invention

[0005] The present invention aims to solve at least one of the technical problems existing in the prior art. For this purpose, the present invention provides a prefabricated fused stress cone and a manufacturing method thereof, which can be prefabricated in advance, can be cross-linked with the cable to form an integral body, and can effectively eliminate the micro-air gap between the stress cone and the insulating layer of the cable and prevent polarization, effectively improving the electrical performance stability and power transmission safety during cable power transmission.

[0006] In a first aspect, a manufacturing method of a prefabricated fused stress cone according to an embodiment of the present invention includes the following steps:

[0007] Manufacture a stress cone insulator, which is made of non-crosslinked polyethylene raw material. Both ends of the stress cone insulator extend outward along the axis direction of the stress cone insulator, and a conical stress coating portion is provided on the outer wall of the stress cone insulator;

[0008] Manufacture a fused stress cone. Coat a semiconductive raw material on the stress coating portion to form a stress control body. After solidification, the stress control body and the stress cone insulator form an integral structure of the fused stress cone.

[0009] According to some embodiments of the present invention, the following steps are further included:

[0010] On-site fusion installation. Sleeve the fused stress cone on the cable, and the inner wall of the stress cone insulator is sequentially attached to the insulation layer and the insulation shielding layer of the cable. Place the fused stress cone and the cable in a composite mold, and through heating, make the stress cone insulator be melt-grafted and crosslinked with the stress control body and the insulation layer of the cable respectively to form an integral fusion structure.

[0011] According to some embodiments of the present invention, before the on-site fusion installation, dissect the outer wall of the cable to strip the conductor, insulation layer, and insulation shielding layer from the cable.

[0012] According to some embodiments of the present invention, after the composite mold is started, heat it to 125°C to 205°C and maintain for 40 minutes to 60 minutes.

[0013] According to some embodiments of the present invention, the shape of the stress coating portion conforms to the stress curve.

[0014] According to some embodiments of the present invention, the specific steps of manufacturing the stress cone insulator include:

[0015] Start the extruder loaded with non-crosslinked polyethylene raw material, preheat the extruder at 120°C to 200°C, and the preheating duration is 30 minutes to 50 minutes;

[0016] Start the stress cone insulator mold, heat it to 120°C to 170°C, and maintain for 20 minutes to 40 minutes;

[0017] Start the extruder to inject the molten non-crosslinked polyethylene raw material into the stress cone insulator mold, and keep the pressure in the stress cone insulator mold at 10 kg / cm² to 18 kg / cm²;

[0018] When the glue overflows from the glue overflow port of the stress cone insulator mold, stop the extruder from extruding glue, and take out the stress cone insulator after cooling.

[0019] Second aspect, a prefabricated fused stress cone according to an embodiment of the present invention includes:

[0020] A stress cone insulator made of non-crosslinked polyethylene raw material. Both ends of the stress cone insulator extend outward along the axis direction of the stress cone insulator, and a conical stress coating portion is provided on the outer wall of the stress cone insulator;

[0021] A stress control body, formed by coating a semiconductive raw material on the stress coating portion.

[0022] According to some embodiments of the present invention, the stress cone insulator includes:

[0023] A conical stress cone portion;

[0024] A first cylindrical body portion. The longest diameter of the cross-section of the first cylindrical body portion is a first diameter. The wider end of the first cylindrical body portion is connected to the wider end of the stress cone portion, and a ring flange is provided at the connection between the first cylindrical body portion and the stress cone portion, and the ring flange surrounds the stress cone portion;

[0025] A second cylindrical body portion. The longest diameter of the cross-section of the second cylindrical body portion is a second diameter, and the second diameter is smaller than the first diameter. One end of the second cylindrical body portion is connected to the narrower end of the stress cone portion and the connection is a continuous transition;

[0026] Wherein, the surface of the ring flange facing the side wall of the stress cone portion and the surface of the stress cone portion form the stress coating portion, and the surface of the stress coating portion is used for coating the semiconductive raw material; the inner wall opening diameters of the first cylindrical body portion, the stress cone portion, and the second cylindrical body portion are the same, and a connection hole penetrating through the stress cone insulator is formed, and the connection hole is used for sleeving a cable

[0027] According to some embodiments of the present invention, the stress cone portion is a first stress cone portion; the first cylindrical body portion is a first cylindrical body portion, one end of the first cylindrical body portion is connected to the wider end of the first stress cone portion, the ring flange at the connection between the first cylindrical body portion and the first stress cone portion is a first ring flange, and the first ring flange surrounds the first stress cone portion; the second cylindrical body portion is a second cylindrical body portion, one end of the second cylindrical body portion is connected to the narrower end of the first stress cone portion and the connection is a continuous transition; wherein, the surface of the first ring flange facing the side wall of the first stress cone portion and the surface of the first stress cone portion form the stress coating portion; the inner wall opening diameters of the first cylindrical body portion, the stress cone portion, and the second cylindrical body portion are the same, and a connection hole penetrating through the stress cone insulator is formed, and the connection hole is used for sleeving a cable.

[0028] According to some embodiments of the present invention, the first cylindrical barrel portion, the first stress cone portion, and the second cylindrical barrel portion are integrally formed structures. The inner wall opening diameters of the first cylindrical barrel portion, the first stress cone portion, and the second cylindrical barrel portion are the same and form a connection hole penetrating the stress cone insulator. The connection hole is used for sleeving a cable.

[0029] According to some embodiments of the present invention, the stress cone portion is a second stress cone portion; the first barrel portion is a conical barrel portion. The wider end of the conical barrel portion is connected to the wider end of the second stress cone portion. The annular flange at the connection between the conical barrel portion and the second stress cone portion is a second annular flange, and the second annular flange surrounds the second stress cone portion; the second barrel portion is a third cylindrical barrel portion. One end of the third cylindrical barrel portion is connected to the narrower end of the second stress cone portion and the connection is a continuous transition; wherein, the surface of the second annular flange facing the side wall of the second stress cone portion and the surface of the second stress cone portion form the stress coating portion.

[0030] According to some embodiments of the present invention, the conical barrel portion, the second stress cone portion, and the third cylindrical barrel portion are integrally formed structures. The inner wall opening diameters of the conical barrel portion, the second stress cone portion, and the third cylindrical barrel portion are the same and form a connection hole penetrating the stress cone insulator. The connection hole is used for sleeving a cable.

[0031] The embodiments of the present invention have at least the following beneficial effects: The surface of the stress cone insulator is provided with a stress coating portion, which can position and coat a semi-conductive raw material to form a stress control body. Therefore, the electrical stress of the fused stress cone is evenly distributed according to the stress cone and maintained at a certain pressure level, ensuring the stability during cable power transmission. At the same time, the stress coating portion has a positioning effect, which is convenient for on-site coating, improving the installation efficiency. At the same time, when it is melt-connected with the cable on-site, the stress control body and the surface of the stress cone insulator will be compounded and cross-linked to form an integral welded structure;

[0032] The stress cone insulator is made of non-crosslinked polyethylene raw material. The characteristics of this material enable it to combine and cross-link with crosslinked polyethylene, that is, the stress cone insulator can be combined and cross-linked with the insulating layer of the cable through melt grafting to form a seamless integral fusion structure. This combination method enables the fusion interface between the two different materials to reach a grafting combination state without air gaps and interfaces, thereby ensuring that the stress cone insulator and the insulating layer of the cable can be completely fused to form a unified whole. During the cable power transmission operation, it can eliminate or avoid the situation of electric field distortion and breakdown caused by microscopic air gaps in the insulating structure, effectively improving the safety and reliability of cable power transmission;

[0033] In addition, prefabricating the fusion stress cone in advance not only simplifies the steps and difficulties of on-site welding and installation, but also facilitates transportation and storage. The transmission site can store the required fusion stress cones in advance, which is convenient for replacement and on-site welding and installation at any time, effectively improving convenience and reliability.

[0034] Additional aspects and advantages of the present invention will be given in part in the following description, become apparent in part from the following description, or be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The above and / or additional aspects and advantages of the present invention will become apparent and be readily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0036] Figure 1 Schematic structural diagram of the stress cone insulator of the first embodiment made by the manufacturing method of the present invention;

[0037] Figure 2 For Figure 1 Schematic structural diagram of another angle showing the structure;

[0038] Figure 3 For Figure 2 Schematic cross-sectional view showing the structure;

[0039] Figure 4 For Figure 3 Schematic cross-sectional view of another angle showing the structure;

[0040] Figure 5 For Figure 1 Schematic plan cross-sectional view showing the structure;

[0041] Figure 6 Schematic structural diagram of installing a cable by applying the embodiment of the present invention;

[0042] Figure 7 Schematic diagram of the state after the fusion stress cone of the embodiment of the present invention is installed on the cable;

[0043] Figure 8 Schematic structural diagram of the stress cone insulator of the second embodiment made by the manufacturing method of the example of the present invention;

[0044] Figure 9 For Figure 8 Schematic structural diagram of another angle showing the structure;

[0045] Figure 10 For Figure 8 Schematic plan cross-sectional view showing the structure;

[0046] Figure 11 Schematic structural diagram of the stress cone insulator of the third embodiment made by the manufacturing method of the example of the present invention;

[0047] Figure 12 is Figure 11 a schematic structural diagram showing another angle of the structure;

[0048] Figure 13 is Figure 11 a planar cross-sectional view showing the structure.

[0049] Reference numerals:

[0050] Detailed implementation manners

[0051] The concept, specific structure and technical effects of the present invention will be clearly and completely described below in conjunction with the embodiments and the drawings, so as to fully understand the purpose, solution and effects of the present invention. It should be noted that, without conflict, the embodiments in this application and the features in the embodiments can be combined with each other.

[0052] It should be noted that, unless otherwise specified, when a certain feature is referred to as "fixed" or "connected" to another feature, it can be directly fixed or connected to the other feature, or indirectly fixed or connected to the other feature. In addition, the up, down, left, right, top, bottom, etc. used in the present invention are only relative to the mutual positional relationship of the components of the present invention in the drawings.

[0053] In addition, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which this technology belongs. The terms used in the description of this specification are only for the purpose of describing specific embodiments, and are not intended to limit the present invention. The term "and / or" used herein includes any combination of one or more of the related listed items.

[0054] It should be understood that although the terms first, second, third, etc. may be used in this disclosure to describe various elements, these elements should not be limited to these terms. These terms are only used to distinguish elements of the same type from each other. For example, without departing from the scope of this disclosure, the first element may also be referred to as the second element, and similarly, the second element may also be referred to as the first element.

[0055] Referring to Figures 1 to 5 or Figures 8 to 10 or Figures 11 to 13 , a method for manufacturing a prefabricated fusion stress cone according to an embodiment of the present invention includes the following steps:

[0056] Manufacture a stress cone insulator 1100. The stress cone insulator 1100 is made of non-crosslinked polyethylene raw material. Both ends of the stress cone insulator 1100 extend outward along the axis direction of the stress cone insulator 1100. A conical stress coating part is provided on the outer wall of the stress cone insulator 1100;

[0057] Manufacture a fused stress cone. Coat a semiconductive raw material on the stress coating part to form a stress control body. After solidification, the stress control body and the stress cone insulator 1100 form an integral structure of the fused stress cone.

[0058] It should be noted that the specific method of coating the semiconductive raw material on the stress coating part can be one of coating, spraying or smearing. Those skilled in the art can select a suitable method for coating according to actual requirements, and the semiconductive raw material may be in a liquid or gaseous state during coating.

[0059] In some embodiments of the present invention, the stress control body is in a horn shape.

[0060] It can be known that the stress control body is made of a semiconductive raw material. Those skilled in the art can determine the stress curve parameters of the stress coating part according to the requirements of the actual transmission parameters of the cable 2000, and then can determine the shape of the inner cavity of the stress cone insulator mold, so that the design of the shape of the stress coating part meets the requirements.

[0061] It can be known that the overall shape of the stress cone insulator 1100 can also be designed according to the design requirements for the shape of the model in the stress cone insulator mold, so that the shape of the stress cone insulator 1100 meets the requirements. That is, the stress cone insulator 1100 and the stress control body are arranged according to the electrical stress structure. The electrical stress is evenly distributed according to the stress cone and maintained at a certain pressure level, which can ensure the working stability of the cable 2000 terminal. And the stress control body can be in a close contact state with the surface of the stress coating part through the smearing method. When it is welded and installed on the cable on site, the stress control body and the surface of the stress coating part can be compound crosslinked, that is, the stress control body and the stress cone insulator 1100 are like an integrally formed structure and will be firmly connected together. It also improves the stability and reliability of the two, ensuring that neither of them will separate or have air gaps under long-term high temperature and high pressure, effectively improving the safety.

[0062] It is known that the insulating layer 2200 of the cable 2000 is made of cross-linked polyethylene material. However, when two objects made of the same cross-linked polyethylene material attempt to be joined by melting, it is very difficult to achieve a true fusion between them. This is because after the fusion connection, there is often an obvious and non-fused interface between the two, and this microscopic air gap is the cause of electric field distortion, which promotes the risk of generating electric trees, and further leads to breakdown accidents during the operation of the cable terminal.

[0063] In the present invention, the stress cone insulator 1100 is made of non-cross-linked polyethylene raw material, and the characteristics of this material enable it to be tightly combined with the main body of the insulating layer 2200 of the cable 2000 by means of fusion welding. Specifically, the stress cone insulator 1100 can be cross-linked and combined with the insulating layer 2200 of the cable 2000 by means of melt grafting to form a seamless integral fusion structure. This combination method enables the fusion interface between the two different materials to reach a grafting combination state without air gaps and interfaces, thus ensuring that the stress cone insulator 1100 and the insulating layer 2200 of the cable 2000 can be completely fused to form a unified whole.

[0064] This fusion not only greatly improves the breakdown strength, but also due to the combination and cross-linking of non-cross-linked polyethylene and cross-linked polyethylene, a thermosetting integral structure is formed, that is, an irreversible three-dimensional network structure is possessed. This means that once the two are combined, they cannot be separated by simple physical methods (such as heating or dissolving). In addition, this integral structure also exhibits better high-temperature resistance performance, enabling the cable 2000 and the fused stress cone to maintain long-term stable operation when the operating temperature of the cable conductor is at 115 °C, thereby significantly improving the stability and safety of the cable during power transmission.

[0065] Through this innovative material combination technology, using the fused stress cone 1000 as the plug-in connector of the cable terminal of the cable 2000, its overall performance has been significantly improved, providing a strong guarantee for the reliability and efficiency of power transmission.

[0066] Reference Figure 6 , in some embodiments of the present invention, before the on-site fusion welding installation, the outer wall of the cable 2000 is dissected to strip the cable 2000 of the conductor 2100, the insulating layer 2200, and the insulating shielding layer 2300. And polishing and cleaning its surface can improve the fusion welding effect between the cable 2000 and the stress cone insulator 1100, further improving the stability and reliability.

[0067] Reference Figure 7 , in some embodiments of the present invention, the following steps are further included:

[0068] Field welding installation. The fusion stress cone is sleeved on the cable 2000, and the inner wall of the stress cone insulator 1100 is successively attached to the insulation layer 2200 and the insulation shielding layer of the cable 2000. The fusion stress cone and the cable 2000 are placed in a composite mold. Through heating, the stress cone insulator 1100 is melt-grafted and crosslinked with the stress control body and the insulation layer 2200 of the cable 2000 respectively to form an integral welding structure.

[0069] In some embodiments of the present invention, after the composite mold is started, it is heated to 125°C to 205°C and maintained for 40 minutes to 60 minutes.

[0070] Making the composite mold work at a state of being heated to 125°C to 205°C and maintained for 40 minutes to 60 minutes can improve the effect of the melt-grafting combination of the stress cone insulator 1100 with the stress control body and the insulation layer 2200 of the cable 2000, enabling the stress cone insulator 1100 to be fully fused with the stress control body or the stress cone insulator 1100 to be fully fused with the insulation layer 2200 of the cable 2000 to form the same integral body respectively. That is, the stress cone insulator 1100 is like growing on the insulation layer 2200 of the cable 2000, and the stress control body is like growing on the stress cone insulator 1100. Since the stress cone insulator 1100 is made of non-crosslinked polyethylene raw material, the characteristics of this material enable it to achieve a tight combination with the body of the insulation layer 2200 of the cable 2000 by means of welding. Specifically, the stress cone insulator 1100 can achieve crosslinking combination with the insulation layer 2200 of the cable 2000 through melt grafting to form a seamless integral welding structure. This combination method enables the fusion interface between the two different materials to reach a grafting combination state without air gaps and interfaces, thereby ensuring that the stress cone insulator 1100 and the insulation layer 2200 of the cable 2000 can be completely fused to form a unified whole.

[0071] Specifically, in some embodiments of the present invention, the composite mold can work at 135°C to 195°C and be maintained for 45 minutes to 55 minutes.

[0072] Specifically, in some embodiments of the present invention, the composite mold can work at 150°C to 190°C and be maintained for 45 minutes to 55 minutes.

[0073] The stress cone insulator 1100 and the insulating layer 2200 of the cable 2000 are fused and grafted crosslinked to form an integral welded structure, enabling the fusion interface between the two to achieve no air gap, and thus having the characteristic of high breakdown strength. Since the stress cone insulator 1100 is made of non-crosslinked polyethylene raw material, the characteristics of this material enable it to be tightly combined with the body of the insulating layer 2200 of the cable 2000 by welding. Specifically, the stress cone insulator 1100 can be combined and crosslinked with the insulating layer 2200 of the cable 2000 by melt grafting to form a seamless integral fusion structure. This combination method enables the fusion interface between two different materials to reach a grafting combination state without air gap and without interface, thereby ensuring that the stress cone insulator 1100 and the insulating layer 2200 of the cable 2000 can be fully fused to form a unified whole.

[0074] In some embodiments of the present invention, both ends of the stress cone insulator 1100 extend outward along the axis direction of the stress cone insulator 1100. The stress cone insulator 1100 has a connection hole 1140 for sleeving the cable 2000. The connection hole 1140 extends along the axis of the stress cone insulator 1100 and penetrates the stress cone insulator 1100.

[0075] It can be known that the connection hole 1140 of the stress cone insulator 1100 can be directly processed by the stress cone insulator mold, or the processing hole can be not prefabricated and processed on-site according to the size of the cable 2000 to determine the size of the connection hole 1140. During actual on-site processing, the cable 2000 is strung into the connection hole 1140 to obtain an assembly, and then processed using a composite mold. After cooling, the fused stress cone will fit the insulating layer 2200 of the cable 2000 to form an integral structure, that is, the stress cone insulator 1100 is like growing on the cable 2000.

[0076] In some embodiments of the present invention, the stress control body is integrally made of a super-smooth semi-conductive material. The stress control body uses a super-smooth semi-conductive material, which can effectively and evenly disperse the electric field, reduce the electric field concentration phenomenon, thereby reducing the electric field strength and avoiding the occurrence of breakdown discharge phenomenon; at the same time, it can improve the material bonding degree, ensure a high material bonding degree with the stress cone insulator 1100, and form a more stable stress cone structure; it can also make the stress cone control body structure more lightweight, easy to process and install, and save costs; and it can improve the reliability. The residual processing stress on the super-smooth surface is extremely small, which helps to improve the reliability and stability of the cable 2000 during power transmission.

[0077] In some embodiments of the present invention, the specific steps of manufacturing the stress cone insulator 1100 include:

[0078] Start the extruder loaded with non-crosslinked polyethylene raw material, preheat the extruder at 120°C to 200°C, and the preheating duration is 30 minutes to 50 minutes;

[0079] Start the stress cone insulator mold, heat it to 120°C to 170°C, and keep it for 20 minutes to 40 minutes;

[0080] Start the extruder, make the extruder inject the molten non-crosslinked polyethylene raw material into the stress cone insulator mold, and keep the pressure in the stress cone insulator mold at 10 kg / cm² to 18 kg / cm²;

[0081] When the glue overflows from the glue overflow port of the stress cone insulator mold, stop the extruder from extruding glue, and take out the stress cone insulator 1100 after cooling.

[0082] In some embodiments of the present invention, the specific steps for manufacturing the stress cone insulator 1100 include:

[0083] Start the extruder loaded with non-crosslinked polyethylene raw material, preheat the extruder at 130°C to 190°C, and the preheating duration is 35 minutes to 45 minutes;

[0084] Start the stress cone insulator mold, heat it to 130°C to 160°C, and keep it for 25 minutes to 35 minutes;

[0085] Start the extruder, make the extruder inject the molten non-crosslinked polyethylene raw material into the stress cone insulator mold, and keep the pressure in the stress cone insulator mold at 11 kg / cm² to 17 kg / cm²;

[0086] When the glue overflows from the glue overflow port of the stress cone insulator mold, stop the extruder from extruding glue, and take out the stress cone insulator 1100 after cooling.

[0087] In a second aspect, a prefabricated fused stress cone according to an embodiment of the present invention includes:

[0088] A stress cone insulator 1100, which is made of non-crosslinked polyethylene raw material, both ends of the stress cone insulator 1100 extend outward along the axis direction of the stress cone insulator 1100, and a conical stress coating part is provided on the outer wall of the stress cone insulator 1100;

[0089] A stress control body, coating a semi-conductive raw material on the stress coating part to form a stress control body

[0090] In some embodiments of the present invention, the stress cone insulator 1100 includes:

[0091] A conical stress cone part;

[0092] The first cylindrical body part, the longest diameter of the cross-section of the first cylindrical body part is the first diameter. The wider end of the first cylindrical body part is connected to the wider end of the stress cone part. A ring flange is provided at the connection between the first cylindrical body part and the stress cone part, and the ring flange surrounds the stress cone part;

[0093] The second cylindrical body part, the longest diameter of the cross-section of the second cylindrical body part is the second diameter, and the second diameter is smaller than the first diameter. One end of the second cylindrical body part is connected to the narrower end of the stress cone part and the connection is a continuous transition;

[0094] Wherein, the surface of the ring flange facing the side wall of the stress cone part and the surface of the stress cone part form a stress coating part, and the surface of the stress coating part is used for coating a semi-conductive raw material; the inner wall opening diameters of the first cylindrical body part, the stress cone part and the second cylindrical body part are the same, and a connection hole 1140 is formed through the stress cone insulator 1100, and the connection hole 1140 is used for sleeving a cable 2000.

[0095] In the present invention, the stress cone insulator 1100 is made of a non-crosslinked polyethylene raw material, and the characteristics of this material enable it to be tightly combined with the body of the insulating layer 2200 of the cable 2000 by means of fusion welding. Specifically, the stress cone insulator 1100 and the insulating layer 2200 of the cable 2000 can be crosslinked and combined by means of melt grafting to form a seamless integral fusion structure. This combination method enables the fusion interface between the two different materials to reach a grafting combination state without air gaps and interfaces, thereby ensuring that the stress cone insulator 1100 and the insulating layer 2200 of the cable 2000 can be completely fused to form a unified whole.

[0096] This fusion not only greatly improves the breakdown strength, but also forms a thermosetting integral structure due to the combination of non-crosslinked polyethylene and crosslinked polyethylene, that is, it has an irreversible three-dimensional network structure. This means that once the two are combined, they cannot be separated by simple physical methods (such as heating or dissolving). In addition, this integral structure also exhibits better high-temperature resistance performance, enabling the cable 2000 and the fusion stress cone to work stably and for a long time in an environment up to 150 °C, thereby significantly improving the stability and safety of the cable during power transmission.

[0097] Through this innovative material combination technology, taking the fusion stress cone as the plug-in connector of the cable terminal of the cable 2000, its overall performance has been significantly improved, providing a strong guarantee for the reliability and efficiency of power transmission.

[0098] In some embodiments of the present invention, the stress cone portion is the first stress cone portion 1120, the first cylindrical body portion is the first cylindrical body portion 1110, and the second cylindrical body portion is the second cylindrical body portion 1130; one end of the first cylindrical body portion 1110 is connected to the wider end of the first stress cone portion 1120, and the annular flange at the connection between the first cylindrical body portion 1110 and the first stress cone portion 1120 is the first annular flange 1111, and the first annular flange 1111 surrounds the first stress cone portion 1120; the second diameter is smaller than the first diameter, and one end of the second cylindrical body portion 1130 is connected to the narrower end of the first stress cone portion 1120 and the connection is a continuous transition; wherein, the surface of the first annular flange 1111 facing the side wall of the first stress cone portion 1120 and the surface of the first stress cone portion 1120 form a stress coating portion.

[0099] In some embodiments of the present invention, the stress cone portion is the second stress cone portion 1160, the first cylindrical body portion is the conical cylindrical body portion 1150, and the second cylindrical body portion is the third cylindrical body portion 1170. The wider end of the conical cylindrical body portion 1150 is connected to the wider end of the second stress cone portion 1160, and the annular flange at the connection between the conical cylindrical body portion 1150 and the second stress cone portion 1160 is the second annular flange 1151, and the second annular flange 1151 surrounds the second stress cone portion 1160; one end of the third cylindrical body portion 1170 is connected to the narrower end of the second stress cone portion 1160 and the connection is a continuous transition; wherein, the surface of the second annular flange 1151 facing the side wall of the second stress cone portion 1160 and the surface of the second stress cone portion 1160 form a stress coating portion.

[0100] The first embodiment:

[0101] According to the manufacturing method of the prefabricated fused stress cone of the first embodiment of the present invention, the following steps are included:

[0102] Manufacture the stress cone insulator 1100. The stress cone insulator 1100 is made of non-crosslinked polyethylene raw material. Both ends of the stress cone insulator 1100 extend outward along the axis direction of the stress cone insulator 1100, and a conical stress coating portion is provided on the outer wall of the stress cone insulator 1100.

[0103] Manufacture the fused stress cone. Coat the semi-conductive raw material on the stress coating portion to form a stress control body. After solidification, the stress control body and the stress cone insulator 1100 form an integral structure of the fused stress cone.

[0104] Specifically, in the first embodiment, the specific steps of manufacturing the stress cone insulator 1100 include:

[0105] Start the extruder loaded with non-crosslinked polyethylene raw material, preheat the extruder at 160 °C, and the preheating duration is 40 minutes.

[0106] Start the stress cone insulator mold, heat it to 145 °C, and maintain for 30 minutes;

[0107] Start the extruder, and let the extruder inject molten non-crosslinked polyethylene raw material into the stress cone insulator mold, and keep the pressure in the stress cone insulator mold at 14 kg / cm²;

[0108] When the glue overflows from the glue overflow port of the stress cone insulator mold, stop the extruder from extruding glue, and take out the stress cone insulator 1100 after cooling.

[0109] The cavity shape in the stress cone insulator mold has been designed in advance according to the set requirements, so that the stress cone insulator 1100 can form a stress coating part.

[0110] In the first embodiment, after applying the manufacturing method of the above embodiment, a stress cone insulator 1100 is manufactured, which is used to connect the cable 2000. The stress cone insulator 1100 is made of non-crosslinked polyethylene raw material. The two ends of the stress cone insulator 1100 extend outward along the axis direction of the stress cone insulator 1100. The outer wall of the stress cone insulator 1100 is provided with a conical stress coating part; the stress coating part is used for coating molten semi-conductive raw material.

[0111] Refer to Figures 1 to 5 , in the first embodiment, the stress cone insulator 1100 includes a first cylindrical barrel part 1110, a first stress cone part 1120 and a second cylindrical barrel part 1130; the first stress cone part 1120 in a conical shape; the longest diameter of the cross-section of the first cylindrical barrel part 1110 is the first diameter. One end of the first cylindrical barrel part 1110 is connected to the wider end of the first stress cone part 1120. A first ring flange 1111 is provided at the connection between the first cylindrical barrel part 1110 and the first stress cone part 1120, and the first ring flange 1111 surrounds the first stress cone part 1120; the second cylindrical barrel part 1130, the longest diameter of the cross-section of the second cylindrical barrel part 1130 is the second diameter, and the second diameter is smaller than the first diameter. One end of the second cylindrical barrel part 1130 is connected to the narrower end of the second stress cone part 1160 and the connection is a continuous transition; wherein, the surface of the first ring flange 1111 facing the side wall of the first stress cone part 1120 and the surface of the first stress cone part 1120 form a stress coating part.

[0112] The outer shape of the stress coating part can meet the requirements of the power stress structure setting, and thus can ensure adaptation to the stress control body and ensure uniform stress cone distribution and maintenance at a certain pressure level after the installation of the electrical stress, guaranteeing the working stability of the cable 2000 terminal. At the same time, a semiconductive raw material is coated on the stress coating part to form a stress control body. Through further heating and extrusion, the stress control body can be melt-connected to the stress cone insulator; it can ensure uniform stress cone distribution during the installation of the electrical stress and maintain it at a certain pressure level.

[0113] In the first embodiment, the first cylindrical barrel part 1110, the first stress cone part 1120, and the second cylindrical barrel part 1130 are integrally formed structures. The inner wall opening diameters of the first cylindrical barrel part 1110, the first stress cone part 1120, and the second cylindrical barrel part 1130 are the same, and a connection hole 1140 passing through the stress cone insulator 1100 is formed. The connection hole 1140 is used for sleeving the cable 2000. It can be known that the first cylindrical barrel part 1110, the first stress cone part 1120, and the second cylindrical barrel part 1130 can be made by molds with corresponding cavity shapes.

[0114] By using the above processing parameters, the stress cone insulator 1100 and the stress control body can be fully grafted, combined, and cross-linked, so that there will be no air gaps or separations at the interface between the stress cone insulator 1100 and the stress control body, which can improve the stability of the fused stress cone. At the same time, prefabricating the fused stress cone in advance can facilitate transportation and storage, and will not cause a decline in the performance of the fused stress cone due to long-term storage. It can also provide spare parts at the power transmission site. When problems occur and replacement is needed or there are new requirements, the stocked items can be directly taken for installation, improving convenience and reliability.

[0115] In the first embodiment, when the fused stress cone is welded and installed on-site, refer to Figure 7 , and it also includes the following steps:

[0116] For on-site welding and installation, the fused stress cone is sleeved on the cable 2000, and the inner wall of the stress cone insulator 1100 is sequentially attached to the insulation layer 2200 and the insulation shielding layer of the cable 2000. The fused stress cone and the cable 2000 are placed in a composite mold. By heating, specifically, making the composite mold work at a temperature of 165°C and maintaining this state for 50 minutes, the stress cone insulator 1100 and the insulation layer 2200 of the cable 2000 can be melt-grafted, cross-linked, and combined, and the stress cone insulator 1100 and the stress control body can be melt-grafted, cross-linked, and combined to form an integral welded structure respectively.

[0117] After cooling, take it out, then the insulating layer 2200 of the cable 2000 and the stress cone insulator 1100 will be melt grafted and combined, so that the two are fully fused to form an integral whole, that is, the stress cone insulator 1100 is like growing on the insulating layer 2200 of the cable 2000. Similarly, the stress control body is also like growing on the stress cone insulator 1100. Among them, before on-site fusion installation, the surface of the cable 2000 has been anatomized and polished and cleaned in advance as required.

[0118] Second Embodiment:

[0119] The main difference in the manufacturing method between the second embodiment and the first embodiment is that the cavity shape of the corresponding mold in the second embodiment is different, that is, the shape of the stress cone insulator 1100 will be different, but the overall process is still carried out according to the manufacturing method of the prefabricated fused stress cone of the present invention. Among them, the temperature and the heating and extrusion time may be appropriately adjusted according to actual needs.

[0120] Refer to Figures 8 to 10 , in the second embodiment, the stress cone insulator 1100 includes a conical cylindrical part 1150, a second stress cone part 1160 and a third cylindrical part 1170; the second stress cone part 1160 is conical, the wider end of the conical cylindrical part 1150 is connected to the wider end of the second stress cone part 1160, and a second annular flange 1151 is provided at the connection between the conical cylindrical part 1150 and the second stress cone part 1160, and the second annular flange 1151 surrounds the second stress cone part 1160; one end of the third cylindrical part 1170 is connected to the narrower end of the first stress cone part 1120 and the connection is a continuous transition; among them, the surface of the second annular flange 1151 facing the side wall of the second stress cone part 1160 forms a stress coating part with the surface of the second stress cone part 1160.

[0121] The conical cylindrical part 1150, the first stress cone part 1120 and the third cylindrical part 1170 are of an integrally formed structure, and the inner wall opening diameters of the conical cylindrical part 1150, the first stress cone part 1120 and the third cylindrical part 1170 are the same and form a connection hole 1140 penetrating through the stress cone insulator 1100, and the connection hole 1140 is used for sleeving the cable 2000.

[0122] Similarly, in the second embodiment, it is also through the steps of on-site fusion installation, sleeving the fused stress cone on the cable 2000, and through heating and extrusion, making the cable 2000 and the fused stress cone melt and connect to form an integral structure.

[0123] It can be known that the main difference between the second embodiment and the first embodiment is that the inclination of a part of the surface of the stress cone insulator 1100 is larger and is conical, which is mainly designed according to the actual requirements of the cable 2000.

[0124] Third Embodiment:

[0125] Referring to Figures 11 to 13 , the main difference in the manufacturing method between the third embodiment and the second embodiment lies in that the cavity shape of the corresponding mold in the third embodiment is different, that is, the shape of the fusion stress cone insulator will be different. The stress cone insulator 1100 in the third embodiment is also conical, but compared with the second embodiment, the cone angle of the conical cylindrical part 1150 in the third embodiment is smaller. Therefore, the main difference between the third embodiment and the second embodiment is that the surface inclination of the stress cone insulator 1100 is smaller, which is mainly designed according to the actual requirements of the cable 2000.

[0126] Combining the second embodiment and the third embodiment, it can be known that the conical cylindrical part 1150, the first stress cone part 1120, and the third cylindrical part 1170 can be made by molds with corresponding cavity shapes.

[0127] It should be noted that in the embodiments of the present invention, the molds, composite molds, extruders, and the structures of the extruders mentioned are all commonly used equipment in the field of processing, so they will not be specifically described in the present invention.

[0128] According to the embodiments of the present invention, by setting it like this, at least the following effects can be achieved. The surface of the stress cone insulator 1100 is provided with a stress coating part, which can position and coat the semiconductive raw material to form a stress control body. Therefore, the electrical stress of the fusion stress cone is evenly distributed according to the stress cone and maintained at a certain pressure level, ensuring the stability of the cable 2000 during power transmission. At the same time, the stress coating part has a positioning effect, which is convenient for on-site coating and improves the installation efficiency. At the same time, when it is melt-connected with the cable on-site, the stress control body and the surface of the stress cone insulator 1100 will be compounded and crosslinked to form an integral welded structure;

[0129] The stress cone insulator 1100 made of non-crosslinked polyethylene raw material has the characteristic that it can combine and crosslink with crosslinked polyethylene, that is, the stress cone insulator 1100 can effectively melt-graft and combine with the insulating layer 2200 of the cable 2000 and crosslink to form a seamless integral fusion structure. This combination method enables the fusion interface between the two different materials to reach a grafting combination state without air gaps and interfaces, thereby ensuring that the stress cone insulator 1100 and the insulating layer of the cable can be completely fused to form a unified whole, effectively avoiding the situation that there may be micro air gaps or separation between the cable 2000 and the stress cone insulator 1100. During the power transmission operation of the cable 2000, the situation of electric field distortion and breakdown caused by micro air gaps in the insulating structure can be eliminated or avoided, effectively improving the safety and reliability of the cable 2000 during power transmission;

[0130] In addition, prefabricating the fusion stress cone in advance not only simplifies the steps and difficulties of on-site fusion welding installation, but also facilitates transportation and storage. The transmission site can store the required fusion stress cones in advance, which is convenient for replacement and on-site fusion welding installation at any time, effectively improving convenience and reliability.

[0131] The above are only the preferred embodiments of the present invention. The present invention is not limited to the above-mentioned implementation manners. As long as it achieves the technical effects of the present invention by the same means, any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present disclosure shall be included within the scope of protection of the present disclosure. All should fall within the scope of protection of the present invention. Within the scope of protection of the present invention, its technical solutions and / or implementation manners can have various different modifications and changes.

Claims

1. A method for manufacturing a prefabricated fusion stress cone, characterized in that: The following steps are involved: A stress cone insulator (1100) is manufactured, wherein the stress cone insulator (1100) is made of a non-cross-linked polyethylene raw material, two ends of the stress cone insulator (1100) respectively extend outwards along the axis direction of the stress cone insulator (1100), and the outer wall of the stress cone insulator (1100) is provided with a stress coating portion in a cone shape; Manufacturing a fused stress cone, coating a semi-conductive raw material on the stress coating portion to form a stress control body, and after solidification, the stress control body and the stress cone insulator (1100) form a fused stress cone with an integrated structure; The stress cone insulator (1100) is used to be melt-grafted and cross-linked with the insulation layer (2200) of the cable (2000) by heating to form an integrated fusion structure, and the insulation layer (2200) is a cross-linked polyethylene material.

2. The method for manufacturing a prefabricated fusion stress cone according to claim 1, characterized in that: The following steps are also included: On-site welding installation, the fused stress cone is sleeved on the cable (2000), and the inner wall of the stress cone insulator (1100) is sequentially bonded to the insulation layer (2200) and the insulation shielding layer of the cable (2000), the fused stress cone and the cable (2000) are placed in a composite mold, and the stress cone insulator (1100) is heated to melt-graft and cross-link with the stress control body and the insulation layer (2200) of the cable (2000) to form an integrated welding structure.

3. The method for manufacturing the prefabricated fusion stress cone according to claim 2, characterized in that: Before the on-site welding installation, the outer wall of the cable (2000) is dissected so that the cable (2000) is stripped to reveal the conductor (2100), the insulation layer (2200), and the insulation shielding layer (2300).

4. The method for manufacturing a prefabricated fusion stress cone according to claim 2, characterized in that: After the composite mold is started, it is heated to 125° C. to 205° C. and maintained for 40 minutes to 60 minutes.

5. The method for manufacturing a prefabricated fusion stress cone according to claim 1 or 2, characterized in that: The shape of the stress coating portion conforms to a stress curve.

6. The method for manufacturing a prefabricated fusion stress cone according to claim 1 or 2, characterized in that: The specific steps of manufacturing the stress cone insulator (1100) include: Starting an extruder loaded with non-cross-linked polyethylene raw material, preheating the extruder at 120° C. to 200° C. for 30 to 50 minutes; Start the stress cone insulator mold, heat it to 120°C to 170°C, and keep it for 20 minutes to 40 minutes; Starting the extruder, allowing the extruder to inject the molten non-cross-linked polyethylene raw material into the stress cone insulator mold, and maintaining the pressure in the stress cone insulator mold at 10 kg / cm² to 18 kg / cm²; When glue is discharged from the overflow port of the stress cone insulator mold, the extruder is stopped from squeezing glue, and the stress cone insulator (1100) is taken out after cooling.

7. A prefabricated fusion stress cone, characterized in that: include: A stress cone insulator (1100), the stress cone insulator (1100) being made of a non-cross-linked polyethylene raw material, the two ends of the stress cone insulator (1100) respectively extending outwards along the axial direction of the stress cone insulator (1100), the outer wall of the stress cone insulator (1100) being provided with a stress coating portion in a cone shape, the stress cone insulator (1100) being used to be melt-grafted and cross-linked with an insulating layer (2200) of a cable (2000) by heating to form an integrated fusion structure, the insulating layer (2200) being a cross-linked polyethylene material; The stress control body is formed by coating a semi-conductive raw material on the stress coating portion.

8. The prefabricated fusion stress cone according to claim 7, characterized in that: The stress cone insulator (1100) comprises: A stress cone portion in a cone shape; A first cylindrical portion, wherein the longest diameter of the cross section of the first cylindrical portion is a first diameter, a wider end of the first cylindrical portion is connected to a wider end of the stress cone portion, and an annular flange is provided at the connection between the first cylindrical portion and the stress cone portion, and the annular flange surrounds the stress cone portion; A second cylindrical portion, wherein the longest diameter of the cross section of the second cylindrical portion is a second diameter, the second diameter is smaller than the first diameter, and one end of the second cylindrical portion is connected to a narrower end of the stress cone portion and the connection is a continuous transition; The surface of the annular flange facing the side wall of the stress cone portion and the surface of the stress cone portion form a stress coating portion, and the surface of the stress coating portion is used for coating a semi-conductive material; the inner wall openings of the first cylindrical portion, the stress cone portion and the second cylindrical portion have the same diameter, and form a connection hole (1140) that passes through the stress cone insulator (1100), and the connection hole (1140) is used for sleeve connection of a cable (2000).

9. The prefabricated fusion stress cone according to claim 8, characterized in that: The stress cone portion is a first stress cone portion (1120); The first barrel portion is a first cylindrical barrel portion (1110), one end of the first cylindrical barrel portion (1110) is connected to a wider end of the first stress cone portion (1120), the annular flange at the connection between the first cylindrical barrel portion (1110) and the first stress cone portion (1120) is a first annular flange (1111), and the first annular flange (1111) surrounds the first stress cone portion (1120); The second barrel portion is a second cylindrical barrel portion (1130), one end of the second cylindrical barrel portion (1130) is connected to a narrower end of the first stress cone portion (1120), and the connection is a continuous transition; The surface of the first annular flange (1111) facing the side wall of the first stress cone portion (1120) and the surface of the first stress cone portion (1120) form the stress coating portion.

10. The prefabricated fusion stress cone according to claim 8, characterized in that: The stress cone portion is a second stress cone portion (1160); The first cylindrical portion is a conical cylindrical portion (1150), a wider end of the conical cylindrical portion (1150) is connected to a wider end of the second stress cone portion (1160), the annular flange at the connection between the conical cylindrical portion (1150) and the second stress cone portion (1160) is a second annular flange (1151), and the second annular flange (1151) surrounds the second stress cone portion (1160); The second barrel portion is a third cylindrical barrel portion (1170), one end of the third cylindrical barrel portion (1170) is connected to a narrower end of the second stress cone portion (1160), and the connection is a continuous transition; The surface of the second annular flange (1151) facing the side wall of the second stress cone portion (1160) and the surface of the second stress cone portion (1160) form the stress coating portion.

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