Submarine cable flexible joint forming die

Abstract

The utility model relates to a submarine cable flexible joint forming die, which is used for insulating extrusion and crosslinking at the joint of conductors of two sections of cables, and comprises a forming device which is provided with a die cavity, the joint of the conductors of the two sections of cables is located in the die cavity, and the inner walls of the two ends of the forming device abut against the outer surfaces of the cables in a sealing manner; the feeding device is arranged at one end of the forming device, the feeding device is provided with a feeding channel, a connecting channel and an annular channel, and the connecting channel communicates with the feeding channel and the annular channel; the sealing device is arranged on the forming device and communicated to the mold cavity, and the sealing device can seal or open the mold cavity; the size of the end, communicated with the feeding channel, of the connecting channel is smaller than that of the end connected with the annular channel. Therefore, the crosslinked polyethylene can uniformly coat the outer side of the conductor joint in the extrusion process, the crosslinked polyethylene melt is ensured to be crosslinked and vulcanized in a sealed environment, the forming quality of the submarine cable flexible joint is ensured, and the crosslinking and vulcanization efficiency and quality are improved.

Description

Technical Field

[0001] This application relates to the technical field of joint manufacturing equipment, and particularly to a forming die for a submarine cable flexible joint. Background Art

[0002] With the development of the marine economy and the investment and construction of a series of key projects such as offshore wind power and interconnection of island power grids, the laying and operation quantity of submarine cables have increased rapidly. For high-voltage and long-length cross-linked polyethylene (XLPE) insulated submarine cables, due to the limitation of the cable manufacturing length, the length of a single cable is at most a dozen kilometers, while the distance between an island or a sea-based facility and the mainland reaches hundreds of kilometers. Therefore, it is necessary to connect single cables with cable joints in advance to reach the required length. Thus, the reliability of the cable joint becomes the key for the entire submarine cable power transmission system to operate normally and reliably.

[0003] Cross-linked polyethylene insulated cables use chemical or physical methods to transform polyethylene from a linear molecular structure to a network molecular structure, that is, thermoplastic polyethylene is transformed into thermosetting cross-linked polyethylene, thereby greatly improving its heat resistance and mechanical properties. It no longer melts after being heated and maintains excellent electrical insulation properties. Currently, the production and application of flexible joints for cross-linked polyethylene (XLPE) insulated submarine cables with voltage levels of 220 kV and below have been realized in China, and multiple manufacturers are conducting research and development on flexible joints for 500 kV cross-linked polyethylene (XLPE) insulated submarine cables.

[0004] The extrusion molded joint (EMJ), also known as the factory joint, needs to start from connecting the conductors of two cables. The two parts of the conductors are connected by welding. Before welding the conductors, the ends of the two cables have been tapered (stress cone), and it is necessary to restore the insulation that has been cut off. This is the technical difficulty in the entire factory joint manufacturing process.

[0005] During the process of restoring the insulation layer, steps such as welding of the cable conductors, restoration of the conductor shielding layer, preheating of the stress cone, extrusion molding of the insulation layer, and cross-linking vulcanization need to be completed respectively, so that the insulating material directly covers the conductor containing the semi-conductive layer, ensuring that the thickness of the joint insulation layer is the same as that of the main insulation, and ensuring that the restored insulation of the joint is consistent with the flexibility of the cable main insulation. Molds are required during both the extrusion molding and cross-linking vulcanization processes of the insulation layer. The structure of the mold directly determines the quality of restoring the insulation layer of the factory joint to a great extent.

[0006] Currently, the commonly used extrusion molds for insulating layers have the feeding port in the middle. The extruder feeds from the middle on one side, and the melt gradually diffuses to the opposite side and both ends. However, this mold structure may cause defects such as insulation eccentricity, air holes or impurities inside the insulation, and unevenness on the insulation surface during the extrusion molding process of the insulating layer. Such a structure leads to the non-uniformity of the insulating material inside the factory joint, which may cause varying degrees of changes in the mechanical properties and electrical properties of the factory joint, thereby affecting the service performance of the factory joint. Summary of the Invention

[0007] Based on this, in view of the problems such as insulation sheet eccentricity caused by the mold structure of the current submarine cable soft joint, which affect the service performance, it is necessary to provide a forming mold for submarine cable soft joints, which can achieve a uniform extrusion molding process of cross-linked polyethylene melt, reduce the eccentricity of the restored insulating layer of the submarine cable soft joint caused by uneven stress at the conductor connection, and at the same time, the cross-linking vulcanization process is carried out in a sealed environment to ensure better fusion of the insulating layer, thereby ensuring the forming quality of the submarine cable soft joint.

[0008] A forming mold for submarine cable soft joints, which is used for insulating extrusion and cross-linking at the conductor connection of two sections of cables. The forming mold for submarine cable soft joints includes:

[0009] A forming device, which has a mold cavity. The conductor connections of the two sections of cables are located in the mold cavity, and the remaining parts of the two sections of cables are exposed outside the forming device, and the inner walls at both ends of the forming device are in sealed contact with the outer surfaces of the cables;

[0010] A feeding device, which is arranged at one end of the forming device. The feeding device has a feeding channel, a connecting channel and an annular channel. The annular channel is arranged circumferentially on the inner wall of the feeding device and communicates with the mold cavity, and the connecting channel communicates the feeding channel and the annular channel; and

[0011] A sealing device, which is arranged on the forming device and communicates with the mold cavity. The sealing device can seal or open the mold cavity;

[0012] Wherein, the size of one end of the connecting channel connected to the feeding channel is smaller than the size of the connecting channel connected to the annular channel.

[0013] In an embodiment of the present application, the forming mold for submarine cable soft joints further includes a first cooling device and a second cooling device. The first cooling device and the second cooling device are respectively arranged at both ends of the forming mold and are used for cooling the outer surfaces of the cables;

[0014] The first cooling device includes a first cooling housing, a first inlet joint, and a first outlet joint. The first inlet joint and the first outlet joint are provided on the first cooling housing and communicate with a first cooling water channel inside the first cooling housing.

[0015] The second cooling device includes a second cooling housing, a second inlet joint, and a second outlet joint. The second inlet joint and the second outlet joint are provided on the second cooling housing and communicate with a second cooling water channel in the second cooling housing.

[0016] In an embodiment of the present application, the first cooling device is integrally provided in the feeding device, or the first cooling device is provided at an end of the feeding device away from the molding device.

[0017] In an embodiment of the present application, the feeding device includes a feeding inner shell and a feeding outer shell. The feeding inner shell is fixed inside the feeding outer shell, and the connection channel and the annular channel are provided in the feeding inner shell. The feeding channel is provided between the feeding outer shell and the feeding inner shell and penetrates through the outer wall of the feeding outer shell.

[0018] And / or, the feeding device includes a first half shell and a second half shell. The first half shell and the second half shell are connected to enclose a first through hole for one of the cables to pass through. The first half shell has the feeding channel penetrating therethrough, and the connection channel and the annular channel are provided in the first half shell and the second half shell.

[0019] In an embodiment of the present application, the molding device includes a mold body and a protective sleeve. The mold body has the mold cavity, and the protective sleeve is provided on the inner wall of the mold cavity. The core conductor connection parts of two sections of the cable are accommodated in the protective sleeve.

[0020] Both ends of the mold body have mating parts that protrude into the mold cavity to abut against the outer surface of the cable, and / or the molding device further includes a seal provided at both ends of the mold body. The seal seals the connection between the inner wall of the mold body and the outer wall of the cable.

[0021] In an embodiment of the present application, the submarine cable soft joint molding die further includes a circulating oil device provided on the mold body for heating or cooling the mold body.

[0022] The circulating oil device includes a temperature control device, a heat exchange pipeline, an inlet pipe, an outlet pipe, and an oil storage tank. The heat exchange pipeline is wound around the outer side of the mold body, or the heat exchange pipeline is integrally arranged in the mold body. The inlet pipe and the outlet pipe are arranged at both ends of the heat exchange pipeline. The temperature control device is connected to the inlet pipe, and the oil storage tank is connected to the outlet pipe and the temperature control device.

[0023] In an embodiment of the present application, the submarine cable soft joint forming mold further includes a heating device. The heating device is connected to the outside of the mold cavity where the cable is exposed, and is used to heat the core conductor of the cable.

[0024] The heating device includes a heating host and a heating component. The heating host is connected to the heating component, and the heating component is connected to the outer surface of the cable.

[0025] In an embodiment of the present application, the sealing device includes a switch valve and a sealing component. The forming device has an exhaust groove communicating with the mold cavity. The switch valve is arranged in the exhaust groove and is used to seal or open the exhaust groove. The sealing component is arranged at the connection of the switch valve and the exhaust groove.

[0026] In an embodiment of the present application, the submarine cable soft joint forming mold further includes an exhaust device, and the exhaust device is used to discharge the crosslinking by-products generated by crosslinking vulcanization.

[0027] The exhaust device includes an inert gas source, a first exhaust pipe, and a second exhaust pipe. The first exhaust pipe and the second exhaust pipe are arranged at both ends of the forming device and communicate with the mold cavity. The first exhaust pipe and the second exhaust pipe are respectively connected to the inert gas source.

[0028] There is a preset phase difference between the first exhaust pipe and the second exhaust pipe in the circumferential direction of the forming mold, and the range of the preset phase difference is 30° - 150°.

[0029] In an embodiment of the present application, the submarine cable soft joint forming mold further includes an auxiliary device, and the auxiliary device is sleeved on the insulating layer at the conductor connection after crosslinking vulcanization.

[0030] The auxiliary device includes an auxiliary exhaust mold and a heating element. The auxiliary exhaust mold has a plurality of hollow parts, and the heating element is arranged in the auxiliary exhaust mold and is used to heat the auxiliary exhaust mold.

[0031] After adopting the above technical solutions, the present application has at least the following technical effects:

[0032] The submarine cable flexible joint molding mold of the present application has a feeding device and a cooling device arranged at both ends of the molding device, the molding device has a mold cavity, the conductor connection of the two sections of the cable is located in the mold cavity, and the rest of the two sections of the cable are exposed from the molding device, and the inner walls at both ends of the molding device are sealed and abutted against the outer surface of the cable to seal the mold cavity. The feeding device has a feeding channel, a connecting channel and an annular channel that are connected, the annular channel is connected to the mold cavity, and the size of the connecting channel connected to the feeding channel at one end is smaller than the size of the end connected to the annular channel, so as to uniformly transport the cross-linked polyethylene melt into the mold cavity to ensure uniform feeding. Moreover, a sealing device is arranged on the molding device and connected to the mold cavity, and the sealing device is connected to the mold cavity. The sealing device can seal the mold cavity during cross-linking vulcanization and open the sealing cavity after the cross-linking vulcanization is completed to ensure the cross-linking vulcanization effect of the insulating layer.

[0033] The submarine cable flexible joint forming mold is provided with a connecting channel and an annular channel on the feeding device, the connecting channel connects the feeding channel and the annular channel, the feeding channel conveys cross-linked polyethylene melt, and the cross-linked polyethylene melt is uniformly injected into the annular channel through the connecting channel, and then the annular channel uniformly extrude the cross-linked polyethylene into the mold cavity, so that the cross-linked polyethylene is uniformly coated on the outside of the conductor connection during the extrusion process, and the eccentricity of the insulation layer restored by the submarine cable flexible joint due to uneven force at the conductor connection is reduced, and at the same time, the lines along the circumferential direction near the feeding channel and the fusion lines on the opposite side of the conductor connection are effectively avoided, so as to ensure the molding quality of the submarine cable flexible joint. Moreover, the cross-linking vulcanization process is carried out in a sealed environment, which can ensure the pressure of the cross-linked polyethylene melt in the mold cavity, ensure better fusion of the insulation layer, and thus ensure the molding quality of the submarine cable flexible joint. At the same time, the submarine cable flexible joint forming mold completes the extrusion and cross-linking vulcanization of the insulation layer restored by the submarine cable flexible joint in one mold, eliminates the step of replacing the mold, and improves the efficiency and quality of cross-linking vulcanization. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is a schematic structural diagram of a submarine cable flexible joint forming mold according to an embodiment of the present application.

[0035] Figure 2 for Figure 1 A three-dimensional view of the feeding device in the submarine cable flexible joint forming mold is shown.

[0036] Figure 3 for Figure 2 A perspective view of the feed device is shown.

[0037] Figure 4 for Figure 1 The cut-away schematic diagram of the molding device in the submarine cable flexible joint molding mold is shown.

[0038] Figure 5 for Figure 1Stereogram of the cooling device in the submarine cable flexible joint forming device shown

[0039] Figure 6 For Figure 5 Front view of the cooling device shown

[0040] Figure 7 For Figure 1 Stereogram of the circulating oil device arranged in the submarine cable flexible joint forming die shown

[0041] Figure 8 For Figure 7 Front view of the submarine cable flexible joint forming die shown

[0042] Figure 9 For Figure 7 Schematic diagram of the forming device in the submarine cable flexible joint forming die shown

[0043] Figure 10 Schematic diagram of the auxiliary device in the submarine cable flexible joint forming die of the present application

[0044] Wherein: 10, submarine cable flexible joint forming die; 100, forming device; 110, die cavity; 120, die body; 130, protective sleeve; 200, feeding device; 211, feeding channel; 212, connecting channel; 213, annular channel; 220, first half shell; 230, second half shell; 240, feeding outer shell; 250, feeding inner shell; 260, first inlet joint; 270, first outlet joint; 300, second cooling device; 310, second cooling housing; 311, first housing; 312, second housing; 320, second inlet joint; 330, second outlet joint; 400, circulating oil device; 410, inlet pipe; 420, outlet pipe; 500, heating device; 510, heating host; 520, heating component; 600, sealing device; 700, exhaust device; 710, first exhaust pipe; 720, second exhaust pipe; 800, auxiliary device; 810, auxiliary exhaust die; 820, heating element; 20, cable; 201, first end; 202, second end; 203, conductor connection; 204, core conductor. Detailed implementation manners

[0045] To make the above objects, features, and advantages of the present application more obvious and understandable, the following detailed description of the specific implementation manners of the present application will be given with reference to the accompanying drawings. Many specific details are set forth in the following description to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present application. Therefore, the present application is not limited by the specific embodiments disclosed below.

[0046] In the description of the present application, it should be understood that if there are terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., the orientation or positional relationship indicated by these terms is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present application.

[0047] In addition, if there are terms such as "first" and "second", these terms are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present application, if there is a term "plurality", the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0048] In the present application, unless otherwise clearly specified and limited, if there are terms such as "mounted", "connected", "joined", "fixed", etc., these terms should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements or the interaction relationship between two elements, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0049] In the present application, unless otherwise clearly specified and limited, if there is a description such as a first feature being "on" or "under" a second feature, the meaning may be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may mean that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "underneath" the second feature may mean that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature.

[0050] It should be noted that if an element is referred to as "fixed to" or "disposed on" another element, it can be directly on the other element or there may be an intermediate element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intermediate element at the same time. If any, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in this application are only for illustrative purposes and do not represent the only implementation.

[0051] See Figure 1 , this application provides a forming die 10 for a submarine cable soft joint. The forming die 10 for the submarine cable soft joint is used to achieve the conductive connection of at least two sections of cables 20 and ensure the insulation of the conductor connection 203, so as to increase the length of the cable 20 to meet the use requirements of different working conditions. The forming die 10 for the submarine cable soft joint can restore the insulating layer at the conductor connection 203 and crosslink and vulcanize the insulating layer, which is convenient for later restoring the shielding layer and the external protection structure of the submarine cable soft joint. In this application, the case where the forming die 10 for the submarine cable soft joint connects two sections of cables 20 is taken as an example for illustration. The connection part of the two sections of cables 20 is the conductor connection 203. When the number of cables 20 is more than two sections, the more than two sections of cables 20 are connected in sequence according to the connection method of the two sections of cables 20, which will not be elaborated here.

[0052] It can be understood that in currently commonly used insulating layer extrusion forming dies, the feeding port is in the middle, and the extruder feeds from the middle on one side, and the melt gradually diffuses to the opposite side and both ends. However, such a die structure may cause defects such as insulation eccentricity, air holes or impurities inside the insulation, and unevenness on the insulation surface during the insulation layer extrusion and molding process, thereby affecting the use performance of the factory joint. For this reason, this application provides a new type of forming die 10 for a submarine cable soft joint, which can make the extrusion molding process of the cross-linked polyethylene melt uniform, so as to uniformly coat the outside of the conductor connection 203, reduce the eccentricity phenomenon of the restored insulating layer of the submarine cable soft joint caused by uneven force on the conductor connection 203, ensure the forming quality of the submarine cable soft joint. At the same time, the cross-linking and vulcanization process is carried out in a sealed environment, which can ensure the pressure of the cross-linked polyethylene melt in the die cavity 110 and ensure better fusion of the insulating layer, thereby ensuring the forming quality of the submarine cable soft joint.

[0053] In this application, the submarine cable soft joint forming die 10 is used for insulating extrusion and cross-linking at the conductor connection 203 of two sections of cables 20. To better illustrate the structure and working principle of the submarine cable soft joint forming die 10, the structures and connection principles of the two sections of cables 20 are introduced first. The structures of the two sections of cables 20 are the same. The inner side of the cable 20 is the core conductor 204, and the outer sides are respectively a semiconductor shielding layer, an insulating layer, an outer shielding layer, and an external protection structure, etc. The semiconductor shielding layer is located outside the core conductor 204, the insulating layer is located outside the semiconductor shielding layer, the outer shielding layer is located outside the insulating layer, and the external protection structure is the outermost side of the cable 20.

[0054] One of the cables 20 has a first end 201, and the other cable 20 has a second end 202. When the two sections of cables 20 are connected, the semiconductor shielding layer, insulating layer, outer shielding layer, and external protection structure at the first end 201 and the second end 202 are removed. The core conductors 204 of the two sections of cables 20 at the first end 201 and the second end 202 are connected, and the connection part therebetween is the conductor connection 203. The semiconductor shielding layer is restored at the conductor connection 203. Then, through the submarine cable soft joint forming die 10 of this application, the insulating layer at the conductor connection 203 is restored and vulcanized and cross-linked. Subsequently, the two sections of cables 20 are taken out of the submarine cable soft joint forming die 10, and the exterior of the submarine cable soft joint is trimmed to restore the outer shielding layer and the external protection structure, realizing the reliable electrical connection of the two sections of cables 20. And the submarine cable soft joint forming die 10 of this application is mainly used to restore the insulating layer at the conductor connection 203. The following introduces the specific structure of the submarine cable soft joint forming die 10 in an embodiment.

[0055] See Figures 1 to 4 , in an embodiment, the submarine cable soft joint forming die 10 includes a forming device 100, a feeding device 200, and a sealing device 600. The forming device 100 has a die cavity 110. The conductor connection 203 of the two sections of cables 20 is located in the die cavity 110. The remaining parts of the two sections of cables 20 are exposed outside the forming device 100, and the inner walls at both ends of the forming device 100 are in sealed contact with the outer surfaces of the cables 20. The feeding device 200 is arranged at one end of the forming device 100. The feeding device 200 has a feeding channel 211, a connecting channel 212, and an annular channel 213. The annular channel 213 is arranged circumferentially on the inner wall of the feeding device 200 and communicates with the die cavity 110. The connecting channel 212 communicates the feeding channel 211 with the annular channel 213. The sealing device 600 is arranged on the forming device 100 and communicates with the die cavity 110. The sealing device 600 can seal or open the die cavity 110. Among them, the size of the end of the connecting channel 212 that communicates with the feeding channel 211 is smaller than the size of the end that connects with the annular channel 213.

[0056] The forming device 100 is the main structure for forming the submarine cable soft joint mold 10. The forming device 100 is hollowly arranged, and its inner cavity is the mold cavity 110. The core conductors 204 at the first ends 201 and the second ends 202 of the two cables 20 are exposed, and the remaining parts of the two cables 20 are all coated with an insulating layer, an outer shielding layer, and an external protection structure. After welding the first ends 201 and the second ends 202 together, after restoring the semiconductor shielding layer on the outside of the conductor connection 203, the conductor connection 203 is placed in the mold cavity 110, and the other parts of the two cables 20 are located outside the mold cavity 110. The insulating layer is restored on the outside of the conductor connection 203 through the mold cavity 110 to achieve reliable insulating electrical connection of the two cables 20 and increase the overall length of the cable 20. It can be understood that, as Figure 1 shown, the forming device 100 extends along the axial direction of the mold cavity 110. The conductor connections 203 of the two cables 20 are located in the mold cavity 110, and the two cables 20 extend in the left and right directions. Here, the axial direction refers to the length direction of the cable 20, and the circumferential direction refers to the circumferential direction of the cable 20.

[0057] The feeding device 200 is located at one end of the forming device 100. The feeding device 200 is used to convey the cross-linked polyethylene melt to the mold cavity 110 so that the cross-linked polyethylene melt can be coated on the conductor connection 203 in the mold cavity 110 and form an insulating layer after cross-linking vulcanization. The feeding device 200 can convey the cross-linked polyethylene melt to the mold cavity 110 in the wall thickness of the feeding device 200 of the forming device 100. The feeding device 200 is hollowly arranged, and one of the cables 20 passes through the feeding device 200. The feeding device 200 is generally annularly arranged.

[0058] In order to ensure that the insulating layer can be evenly coated on the outside of the conductor connection 203, the present application is provided with a feeding channel 211, a connecting channel 212, and an annular channel 213 in the feeding device 200, and the size of one end of the connecting channel 212 communicating with the feeding channel 211 is smaller than the size of the end connecting with the annular channel 213. That is to say, in Figure 2 the shown direction, the size of the left side of the connecting channel 212 is smaller than the size of the right side, and the connecting channel 212 is arranged in a diffused shape. It can be understood that the feeding device 200 has a certain wall thickness. The feeding channel 211, the connecting channel 212, and the annular channel 213 are located in the wall thickness of the feeding device 200. The annular channel 213 is arranged in the feeding device 200 along the circumferential direction and communicates with the mold cavity 110. One end of the feeding channel 211 is located in the wall thickness, and the other end penetrates through the outer wall of the feeding device 200. The connecting channel 212 communicates the feeding channel 211 and the annular channel 213.

[0059] The cross-linked polyethylene melt enters the connecting channel 212 through the feed channel 211, and the cross-linked polyethylene melt in the feed channel 211 can be uniformly transported to the annular channel 213 through the connecting channel 212, and then the annular channel 213 can uniformly extrude the cross-linked polyethylene melt into the mold cavity 110, and then coat the outside of the conductor connection 203 to form an insulating layer. At this time, the insulating layer can be uniformly coated on the outside of the conductor connection 203. It is worth noting that, due to the diffusion shape of the connecting channel 212 and the flow characteristics of the fluid, the cross-linked polyethylene melt can first fill one end close to the feed channel 211, and then gradually diffuse to the annular channel 213, so that the cross-linked polyethylene melt can flow uniformly.

[0060] The present application sets the feeding device 200 at one end of the molding device 100, and extrude the cross-linked polyethylene melt into the mold cavity 110 along the axial direction at the end of the molding device 100, so that the cross-linked polyethylene melt is pushed forward as a whole in the axial direction and evenly enters the mold cavity 110, so that the insulating layer is evenly coated on the outside of the conductor connection 203, reducing the eccentricity of the insulating layer restored by the submarine cable flexible joint due to uneven force at the conductor connection 203. At the same time, it can also effectively avoid the lines along the circumferential direction near the feeding channel 211 and the fusion lines on the opposite side of the conductor connection 203, ensuring the molding quality of the submarine cable flexible joint. In this way, the insulating layer inside the submarine cable flexible joint is evenly distributed to reduce the eccentricity and fusion lines of the insulating layer of the submarine cable flexible joint, so that the submarine cable flexible joint has good mechanical and electrical properties, ensuring the performance of the submarine cable flexible joint.

[0061] Moreover, the present application simplifies the molding process of the submarine cable flexible joint. After the feeding device 200 uniformly extrude the cross-linked polyethylene melt to the outside of the conductor connection 203, the insulating layer is directly cross-linked and vulcanized in the mold cavity 110. That is, the extrusion and cross-linking vulcanization of the restored insulating layer of the submarine cable flexible joint are completed in a set of molds. At the same time, after the cable 20 is installed in the molding device 100, the outer surface of the cable 20 abuts against the inner part of the end of the molding device 100, and the mold cavity 110 of the molding device 100 is a sealed structure. In this way, the cross-linked polyethylene melt can be cross-linked and vulcanized in a sealed environment, so that the interface of the restored insulating layer and the body insulating layer is better integrated, ensuring the molding quality of the submarine cable flexible joint. The sealing device 600 is arranged on the molding device 100 and connected to the mold cavity 110, so that the mold cavity 110 forms a sealed environment and facilitates the disassembly of the mold. When the sealing device 600 opens the mold cavity 110, the gas in the mold cavity 110 can be discharged to the outside through the sealing device 600. When the sealing device 600 seals the molding mold cavity 110 , the mold cavity 110 is in a closed state, and no gas can enter or exit.

[0062] During the process of extruding the insulating layer, the sealing device 600 opens the mold cavity 110, fills the mold cavity 110 between the cross-linked polyethylene melts, and occupies the space in the mold cavity 110 between the cross-linked polyethylene melts to discharge the gas in the mold cavity 110. When the cross-linked polyethylene melt fills the entire mold cavity 110, the sealing device 600 is closed. At this time, the mold cavity 110 is in a sealed state, and the cross-linked polyethylene melt in the mold cavity 110 can maintain a certain pressure. After a predetermined time, it promotes the fusion of the interface between the insulating layer and the body insulating layer. That is, the sealing device 600 can effectively seal the mold cavity 110. When the cross-linked polyethylene melt is extruded and formed, the sealing device 600 opens the mold cavity 110 to effectively discharge the cross-linked by-products in the mold cavity 110. That is, when the mold cavity 110 is filled with cross-linked polyethylene, the sealing device 600 is closed to keep sufficient pressure in the mold cavity 110, which is beneficial to the fusion of the interface between the insulating layer and the body insulating layer. After the cross-linking vulcanization is completed, the sealing device 600 is opened to degas the forming device 100 and effectively discharge the cross-linked by-products generated during the vulcanization process.

[0063] For the submarine cable soft joint forming mold 10 of the above embodiment, a connecting channel 212 and an annular channel 213 are arranged on the feeding device 200. The connecting channel 212 connects the feeding channel 211 and the annular channel 213. The feeding channel 211 conveys the cross-linked polyethylene melt, and the cross-linked polyethylene melt is uniformly injected into the annular channel 213 through the connecting channel 212. Then, the annular channel 213 uniformly extrudes the cross-linked polyethylene into the mold cavity 110, so that the cross-linked polyethylene is uniformly coated on the outside of the conductor connection 203 during the extrusion process, reducing the eccentricity phenomenon of the restored insulating layer of the submarine cable soft joint caused by uneven force on the conductor connection 203. At the same time, it effectively avoids the circumferential lines near the feeding channel 211 and the fusion lines on the opposite side of the conductor connection 203, ensuring the forming quality of the submarine cable soft joint. Moreover, the cross-linking vulcanization process is carried out in a sealed environment, which can ensure the pressure of the cross-linked polyethylene melt in the mold cavity 110, ensure better fusion of the insulating layer, and thus ensure the forming quality of the submarine cable soft joint. At the same time, the submarine cable soft joint forming mold 10 completes the extrusion and cross-linking vulcanization of the restored insulating layer of the submarine cable soft joint in one mold, cancels the step of changing the mold, and improves the efficiency and quality of cross-linking vulcanization.

[0064] See Figure 2 and Figure 3, in one embodiment, the number of the connecting channels 212 is multiple, and the multiple connecting channels 212 are circumferentially spaced apart on the feeding device 200. That is to say, the number of the connecting channels 212 is multiple, and the multiple connecting channels 212 can communicate the feeding channel 211 with the annular channel 213 in the circumferential direction of the feeding channel 211. In this way, the feeding channel 211 can uniformly transport the cross-linked polyethylene melt into the annular channel 213 through the multiple connecting channels 212, so as to uniformly extrude the cross-linked polyethylene melt into the mold cavity 110 to form a uniform insulating layer on the outer side of the conductor connection 203. Optionally, the connecting channel 212 is a fan-shaped flow channel, a conical flow channel, etc., as long as it can uniformly transport the cross-linked polyethylene melt into the annular channel 213. Optionally, the inner wall of the connecting channel 212 can be arc-shaped or straight. In this embodiment, the number of the connecting channels 212 is two, and the two connecting channels 212 are symmetrically arranged and communicate the feeding channel 211 with the annular channel 213 to uniformly transport the cross-linked polyethylene melt.

[0065] In one embodiment, the feeding device 200 includes a feeding inner shell 250 and a feeding outer shell 240. The feeding inner shell 250 is fixed inside the feeding outer shell 240, and the connecting channel 212 and the annular channel 213 are arranged in the feeding inner shell 250. The feeding channel 211 is arranged between the feeding outer shell 240 and the feeding inner shell 250 and penetrates through the outer wall of the feeding outer shell 240. The feeding inner shell 250 is located inside the feeding outer shell 240 and fits against the inner wall of the feeding outer shell 240. The feeding inner shell 250 is fixed to the feeding outer shell 240 by screws to ensure reliable fixation. The connecting channel 212 and the annular channel 213 are arranged in the feeding inner shell 250. One end of the feeding channel 211 penetrates into the feeding inner shell 250 and communicates with the connecting channel 212, and the other end of the feeding channel 211 penetrates through the feeding outer shell 240 to realize the transportation of the cross-linked polyethylene melt.

[0066] In one embodiment, the feeding device 200 includes a first half shell 220 and a second half shell 230. The first half shell 220 and the second half shell 230 are connected to enclose a first through hole for one of the cables 20 to pass through; the first half shell 220 has a feeding channel 211 penetrating therethrough, and the connecting channel 212 and the annular channel 213 are arranged in the first half shell 220 and the second half shell 230. That is to say, the feeding device 200 is divided into two semi-circular parts, namely the first half shell 220 and the second half shell 230. After the first half shell 220 and the second half shell 230 are connected in an opposing manner, they enclose an annular structure, and the inner cavity is the first through hole, and the cable 20 extends through the first through hole. When the conductor connection 203 is placed in the mold cavity 110, the first half shell 220 and the second half shell 230 are clamped on the outer side of the cable 20 from both sides of the cable 20, and the first half shell 220 and the second half shell 230 are fixedly connected by bolts. In this way, the installation and disassembly of the cable 20 in the submarine cable soft joint forming mold 10 can be facilitated.

[0067] It is understandable that the feeding device 200 includes a first half shell 220 and a second half shell 230. Both the first half shell 220 and the second half shell 230 include a feeding inner shell 250 and a feeding outer shell 240. The feeding outer shell 240 and the feeding inner shell 250 are fixedly connected by screws and pins to form the complete first half shell 220 and second half shell 230. When installing the feeding device 200 on the cable 20, the first half shell 220 and the second half shell 230 are clamped on the outer side of the cable 20 from both sides of the cable 20, and the first half shell 220 and the second half shell 230 are fixedly connected by bolts.

[0068] Optionally, the feeding channel 211 is located in the second half shell 230, so that the cross-linked polyethylene melt enters from the feeding channel 211 of the second half shell 230, enters the annular channel 213 through the connecting channel 212, and then enters the mold cavity 110 of the molding device 100. Optionally, the edges of the first half shell 220 and the second half shell 230 are provided with correspondingly arranged lugs. When the first half shell 220 and the second half shell 230 are connected, the bolts tightly connect the lugs of the first half shell 220 and the second half shell 230.

[0069] See Figure 1 、 Figure 2 Figure 5 and Figure 6 In an embodiment, the submarine cable soft joint molding die 10 further includes a first cooling device and a second cooling device 300. The first cooling device and the second cooling device 300 are respectively arranged at both ends of the molding die and are used to cool the outer surface of the cable 20. The first cooling device and the second cooling device 300 are generally annular. The cable 20 passes through the first cooling device and the second cooling device 300 and extends out. A coolant such as cooling water can flow in the first cooling device and the second cooling device 300, so that the first cooling device and the second cooling device 300 can cool the surface layer of the cable 20 to meet the cooling requirements and avoid scalding the surface layer of the adjacent area cable 20 due to excessive temperature during the cross-linking vulcanization process.

[0070] See Figure 1 and Figure 2, in one embodiment, the first cooling device is integrally provided in the feeding device 200. That is to say, in this embodiment, the feeding device 200 is used as the first cooling housing, and the first inlet joint 260 and the first outlet joint 270 are directly provided on the feeding device 200. In this way, while not affecting the use of the feeding device 200, the internal space of the feeding device 200 can be fully utilized, and the overall size of the submarine cable soft joint forming die 10 can be reduced. Of course, in other embodiments of the present application, the first cooling device is provided at one end of the feeding device 200 away from the forming device 100. That is, the first cooling device is separately provided from the feeding device 200, and the first cooling device is located on one side of the feeding device 200 away from the forming device 100 to cool the surface layer of the cable 20.

[0071] In one embodiment, the first cooling device includes a first cooling housing, a first inlet joint 260 and a first outlet joint 270. The first inlet joint 260 and the first outlet joint 270 are provided on the first cooling housing and communicate with the first cooling water path inside the first cooling housing. The second cooling device 300 includes a second cooling housing 310, a second inlet joint 320 and a second outlet joint 330. The second inlet joint 320 and the second outlet joint 330 are provided on the second cooling housing 310 and communicate with the second cooling water path in the second cooling housing 310.

[0072] The first cooling housing is annular. A first cooling water path is provided inside the first cooling housing (the inner feeding housing 250). The inlet of the first cooling water path is connected to the first inlet joint 260, and the outlet of the first cooling water path is connected to the first outlet joint 270. Cooling water enters the first cooling water path from the first inlet joint 260 and flows in the first cooling water path to cool the surface layer of the cable 20. The heated cooling water flows out through the first outlet joint 270. It can be understood that during extrusion molding, the first cooling water path is closed, and during the cross-linking vulcanization process, the first cooling water path is opened. The cooling water in the first cooling water path can cool the surface layer of the cable 20 adjacent to the mold cavity 110.

[0073] The second cooling housing 310 is annular. A second cooling water path is provided inside the second cooling housing 310. The inlet of the second cooling water path is connected to the second inlet joint 320, and the outlet of the second cooling water path is connected to the second outlet joint 330. Cooling water enters the second cooling water path from the second inlet joint 320270 and flows in the second cooling water path to cool the surface layer of the cable 20. The heated cooling water flows out through the second outlet joint 330280. It can be understood that during extrusion molding, the second cooling water path is closed, and during the cross-linking vulcanization process, the second cooling water path is opened. The cooling water in the second cooling water path can cool the surface layer of the cable 20 adjacent to the mold cavity 110.

[0074] Optionally, the second cooling housing 310 includes a first housing 311 and a second housing 312. The first housing 311 and the second housing 312 enclose a second through hole for the cable 20 to pass through. That is to say, the second cooling device 300 is divided into two semi-circular parts, namely the first housing 311 and the second housing 312. After the first housing 311 and the second housing 312 are joined together, they enclose an annular structure with an inner cavity being the second through hole, and the cable 20 extends through the second through hole. When the conductor connection 203 is placed in the mold cavity 110, the first housing 311 and the second housing 312 are clamped on the outer side of the cable 20 from both sides of the cable 20, and the first housing 311 and the second housing 312 are fixedly connected by bolts. In this way, the installation and disassembly of the cable 20 in the submarine cable soft joint forming mold 10 can be facilitated. Optionally, the edges of the first housing 311 and the second housing 312 are provided with corresponding lugs, and when the first housing 311 and the second housing 312 are connected, the lugs of the first housing 311 and the second housing 312 are fastened and connected by bolts.

[0075] See Figure 1 and Figure 4 , in an embodiment, the forming device 100 includes a mold body 120 and a protective sleeve 130. The mold body 120 has a mold cavity 110, and the protective sleeve 130 is disposed on the inner wall of the mold cavity 110, and the core conductors 204 of two sections of the cable 20 at the connection are accommodated in the protective sleeve 130. The mold body 120 is a hollow annular structure, and its internal cavity is the mold cavity 110. The conductor connections 203 of two sections of the cable 20 are located in the mold cavity 110. The protective sleeve 130 can cover the conductor connection 203, which is convenient for the demolding of the conductor connection 203. At the same time, it can also ensure the thickness of the insulating layer and prevent the protrusion of the insulating layer, the outer shielding layer and the external protection structure of the conductor connection 203 from the surface layer of the cable 20. Optionally, the protective sleeve 130 is a silica gel sleeve.

[0076] After the protective sleeve 130 covers the conductor connection 203 and is installed in the mold cavity 110 of the mold body 120, one end of the protective sleeve 130 is fixed between the feeding device 200 and the mold body 120, and the other end is fixed between the mold body 120 and the surface layer of the cable 20. The protective sleeve 130 is sleeved on one of the cables 20 before the two cables 20 are welded. After the two cables 20 are welded and connected, the protective sleeve 130 is sleeved on the conductor connections 203 of the two cables 20, and then the assembled protective sleeve 130 and the two core conductors 204 are installed in the mold cavity 110 of the mold body 120, and then the feeding device 200 and the second cooling device 300 are installed, etc. During extrusion molding, the cross-linked polyethylene melt is injected into the protective sleeve 130 and covers the outside of the conductor connection 203. During demolding, the mold body 120 is separated from the protective sleeve 130, and then the protective sleeve 130 can be removed from the conductor connection 203.

[0077] See Figure 1 Figure 1 , in one embodiment, the mold body 120 includes a first part shell and a second part shell, and the first part shell and the second part shell are connected and enclosed to form a mold cavity 110. The structure form that divides the mold body 120 into two parts is respectively the first part shell and the second part shell. After the first part shell and the second part shell are joined and connected, they enclose a complete annular structure, and its inner cavity is the mold cavity 110. When the conductor connection 203 is placed in the mold cavity 110, the first part shell and the second part shell are stuck on the outer side of the cable 20 from both sides of the conductor connection 203, and the first part shell and the second part shell are fixedly connected by bolts. In this way, the installation and disassembly of the cable 20 in the submarine cable soft joint forming mold 10 can be facilitated. Optionally, the edges of the first part shell and the second part shell have correspondingly arranged lugs. When the first part shell and the second part shell are connected, the bolts tightly connect the lugs of the first part shell and the second part shell.

[0078]

[0078] , in one embodiment, both ends of the mold body 120 have mating parts that protrude towards the mold cavity 110 to abut against the outer surface of the cable 20. That is to say, the mold cavity 110 forms a tapered structure form from the middle to the end to form a constriction at the end. In this way, the inner wall of the end of the mold body 120 can abut against the outer surface of the cable 20, so that the mold cavity 110 is closed, ensuring the crosslinking vulcanization quality of the insulating layer. Of course, in other embodiments of the present application, the forming device 100 further includes a sealing member provided at both ends of the mold body 120, and the sealing member seals and connects the inner wall of the mold body 120 and the outer wall of the cable 20. The sealing member can seal and connect the mold body 120 and the cable 20 at the ends of the mold body 120, so that the mold cavity 110 is closed, ensuring the crosslinking vulcanization quality of the insulating layer. Optionally, the sealing member is an O-ring or the like.

[0079] See Figures 7 to 9 Figures 7 to 9 , in one embodiment, the submarine cable soft joint forming mold 10 further includes a circulating oil device 400 provided in the mold body 120 for heating or cooling the mold body 120. The circulating oil device 400 is provided in the mold body 120, and the circulating oil device 400 passes circulating oil into the mold body 120. When the circulating oil flows in the mold body 120, it can heat or cool the crosslinked polyethylene melt in the mold cavity 110, so that the crosslinked polyethylene melt can be crosslinked and vulcanized to form an insulating layer.

[0080] During the extrusion of cross-linked polyethylene melt, the circulating oil device 400 does not work. At this time, the cross-linked polyethylene melt can be evenly extruded into the mold cavity 110 and coated on the outside of the conductor connection 203. After the extrusion is completed, the circulating oil device 400 heats the mold body 120 through circulating oil (hot oil), and then heats the cross-linked polyethylene melt, so that the cross-linked polyethylene melt can cross-link and vulcanize in the sealed mold cavity 110 to form an insulating layer. When the cross-linking and vulcanization are completed, the insulating layer needs to be cooled down. At this time, the circulating oil device 400 cools the mold body 120 through circulating oil (cold oil) to ensure the consistency of the temperature drop in the insulating layer, thereby ensuring the forming quality of the insulating layer.

[0081] That is to say, the forming mold 10 of the submarine cable soft joint of the present application uses the circulating oil device 400 to realize the heating and cooling of the forming device 100. The circulating oil heating device 500 can ensure the cross-linking and vulcanization quality of the insulating layer during the cross-linking and vulcanization process, and can also ensure the consistency of the temperature drop during the cooling process. The circulating oil device 400 can perform an oil bath on the mold body 120. Through the oil bath, the heating or cooling of the mold body 120 can be accurately and evenly regulated, and an insulating layer with a higher cross-linking degree and better crystallization characteristics can be obtained.

[0082] See Figures 7 to 9 , in an embodiment, the circulating oil device 400 includes a temperature control device (not shown), a heat exchange pipeline (not shown), an inlet pipe 410, an outlet pipe 420, and an oil storage tank (not shown). The heat exchange pipeline is wound around the outside of the mold body 120, or the heat exchange pipeline is integrally arranged in the mold body 120. The inlet pipe 410 and the outlet pipe 420 are arranged at both ends of the heat exchange pipeline. The temperature control device is connected to the inlet pipe 410, and the oil storage tank connects the outlet pipe 420 and the temperature control device.

[0083] The temperature control device is a heating and cooling device. The inlet end of the heat exchange pipeline is provided with the inlet pipe 410, and the outlet pipe 420 of the heat exchange pipeline is provided with the outlet pipe 420. The oil storage tank communicates the outlet pipe 420 and the temperature control device, and the temperature control device is connected to the inlet pipe 410. After the circulating oil in the oil storage tank enters the temperature control device, the temperature control device heats or cools the circulating oil, and then transports the circulating oil to the heat exchange pipeline through the inlet pipe 410. The circulating oil exchanges heat in the heat exchange pipeline to heat or cool the cross-linked polyethylene melt. The heat-exchanged circulating oil flows out through the outlet pipe 420 and returns to the oil storage tank for the next cycle of use of the circulating oil.

[0084] In this embodiment, the heat exchange pipeline is integrally arranged in the mold body 120. In this way, the volume of the forming device 100 can be reduced, and at the same time, the heat or cold of the circulating oil can be concentrated in the mold cavity 110 to ensure the heating or cooling effect of the cross-linked polyethylene melt. Of course, in other embodiments of the present application, the heat exchange pipeline can also be wound around the outside of the mold body 120. AsFigures 7 to 9 As shown, only the inlet pipe 410 and the outlet pipe 420 of the circulating oil device 400 are shown in the figure, and the heat exchange pipeline, the oil storage tank, and the temperature control equipment are not shown.

[0085] Refer to Figure 1 、 Figure 7 and Figure 8 In one embodiment, the submarine cable soft joint forming die 10 further includes a heating device 500. The heating device 500 is connected to the outside of the die cavity 110 where the cable 20 is exposed, and is used to heat the core conductor 204 of the cable 20. The heating of the heating device 500 realizes the cross-linking vulcanization of the cross-linked polyethylene melt in the die cavity 110 of the forming device 100, so as to facilitate the formation of the insulating layer. Specifically, the heating device 500 is connected to the outer surfaces of two sections of the cable 20, and can heat the core conductors 204 inside the two sections of the cable 20, making the temperature field of the cross-linking vulcanization more uniform to meet the temperature requirements of the cross-linking vulcanization process.

[0086] In one embodiment, the heating device 500 includes a heating main unit 510 and a heating component 520. The heating main unit 510 is connected to the heating component 520, and the heating component 520 is connected to the outer surface of the cable 20. The heating main unit 510 is the heating main unit of the heating device 500, and the heating component 520 is the heat output component of the heating device 500. When the heating main unit 510 heats, it can control the heating component 520 to heat the core conductor 204 of the cable 20. Optionally, the heating main unit 510 is a high-frequency electromagnetic induction heater. Using the electromagnetic induction heater to heat the core conductor 204 of the cable 20 makes the temperature field of the cross-linking vulcanization more uniform. Optionally, the number of the heating devices 500 is two, and each cable 20 corresponds to one heating device 500.

[0087] This application uses the combined action of the circulating oil device 400 and the heating device 500 to meet the heating requirements of the cross-linked polyethylene melt during the cross-linking vulcanization process, so as to ensure the heat demand for cross-linking vulcanization. Of course, in other embodiments of this application, only one of the circulating oil device 400 and the heating device 500 can also be used for heating, and it can also meet the cross-linking vulcanization.

[0088] Refer to Figure 1 In one embodiment, the sealing device 600 includes a switching valve and a sealing assembly. The forming device 100 has an exhaust groove communicating with the die cavity 110. The switching valve is arranged in the exhaust groove and is used to seal or open the exhaust groove. The sealing assembly is arranged at the connection between the switching valve and the exhaust groove. Optionally, the sealing assembly includes sealing components such as sealing strips and sealing rings, and these sealing components can effectively seal the die cavity 110.

[0089] The switching valve is a component for achieving the sealing and opening of the mold cavity 110 by the sealing device 600. The mold body 120 of the molding device 100 has exhaust grooves penetratingly provided, and the exhaust grooves communicate the mold cavity 110 with the outside of the molding device 100. The switching valve is arranged in the exhaust grooves to control the sealing or opening of the mold cavity 110. When cross-linked polyethylene melt is extruded and molded, the switching valve is opened to effectively discharge the gas in the mold cavity 110. After the mold cavity 110 is filled with cross-linked polyethylene melt, the switching valve is closed to keep sufficient pressure in the mold cavity 110, which is beneficial to the fusion of the interface between the insulating layer and the body insulating layer. After the vulcanization is completed, the switching valve is opened, and an air pump is connected to degas the submarine cable soft joint, effectively discharging the gas generated during the vulcanization process.

[0090] See Figure 8 , in one embodiment, the submarine cable soft joint molding die 10 further includes an exhaust device 700 for discharging cross-linking by-products generated by cross-linking vulcanization. After the cross-linking vulcanization is completed, when the switching valve is opened and external gas enters the mold cavity 110, the demolding requirement of the insulating layer can be met. However, there are still cross-linking by-products in the mold cavity 110, which affect the molding quality of the insulating layer. This exhaust device 700 can introduce and discharge inert gas into the mold cavity 110, and the inert gas can carry away the cross-linking by-products in the mold cavity 110.

[0091] See Figure 8 , in one embodiment, the exhaust device 700 includes an inert gas source (not shown), a first exhaust pipe 710, and a second exhaust pipe 720. The first exhaust pipe 710 and the second exhaust pipe 720 are arranged at both ends of the molding device 100 and communicate with the mold cavity 110. The first exhaust pipe 710 and the second exhaust pipe 720 are respectively connected to the inert gas source. During the extrusion and cross-linking vulcanization of cross-linked polyethylene melt, the first exhaust pipe 710 and the second exhaust pipe 720 are closed. When the sealing device 600 is opened for a period of time, the first exhaust pipe 710 and the second exhaust pipe 720 are opened. At this time, the inert gas source can input inert gas into the mold cavity 110 through the first exhaust pipe 710. After the inert gas adsorbs the cross-linking by-products in the mold cavity 110, it is discharged through the second exhaust pipe 720.

[0092] In Figure 8 , only the first exhaust pipe 710 and the second exhaust pipe 720 are shown, and the inert gas source is not shown. Moreover, the position of the first exhaust pipe 710 is only for illustration and can also be in other positions. Optionally, the inert gas source is a nitrogen gas source, etc. Optionally, the exhaust device 700 further includes a heating part that can heat the inert gas. That is to say, heated inert gas such as nitrogen is introduced into the mold cavity 110 to ensure the exhaust effect.

[0093] In one embodiment, the first exhaust pipe 710 and the second exhaust pipe 720 have a preset phase difference in the circumferential direction of the mold body 120, and the range of the preset phase difference is 30° to 150°. In this way, after the first exhaust pipe 710 and the second exhaust pipe 720 are arranged as above, it can ensure that the inert gas has a long flow path in the mold cavity 110 and ensure the exhaust effect.

[0094] See Figure 10 , in one embodiment, the submarine cable soft joint forming mold 10 further includes an auxiliary device 800, and the auxiliary device 800 is sleeved on the insulating layer at the conductor connection 203 after crosslinking vulcanization. After the crosslinking by-products are discharged by the exhaust device 700, the forming device 100, the feeding device 200, and the second cooling device 300 are disassembled. At this time, there are still some crosslinking by-products in the insulating layer. In order to ensure the forming quality of the insulating layer, the submarine cable soft joint forming mold 10 of the present application also designs an auxiliary device 800, and the auxiliary device 800 can discharge the remaining crosslinking by-products in the insulating layer.

[0095] In one embodiment, the auxiliary device 800 includes an auxiliary exhaust mold 810 and a heating element 820. The auxiliary exhaust mold 810 has a plurality of hollow parts, and the heating element 820 is arranged in the auxiliary exhaust mold 810 for heating the auxiliary exhaust mold 810. The auxiliary exhaust mold 810 can be sleeved and clamped on the outside of the insulating layer. After the heating element 820 is powered on, it can emit heat to discharge the crosslinking by-products in the insulating layer in a relatively hot environment. Moreover, the hollow parts on the auxiliary exhaust mold 810 can facilitate the discharge of the crosslinking by-products. In one embodiment, the auxiliary exhaust mold 810 includes a first mold and a second mold, and the first mold and the second mold are combined to form the auxiliary exhaust mold 810 and are clamped on the outside of the insulating layer.

[0096] When connecting two cables 20 with the submarine cable soft joint forming mold 10 of the present application, the first ends 201 and the second ends 202 of the two cables 20 are stripped to remove the external protection structure, the outer shielding layer, the insulating layer, and the semiconductor shielding layer. At this time, the first end 201 part and the second end 202 part are the core conductors 204. Then, the first ends 201 and the second ends 202 of the two cables 20 are processed into stress cone surfaces, and the protective sleeve 130 (mentioned later) is sleeved on the outside of one of the cables 20. The core conductors 204 of the first end 201 and the second end 202 are connected by welding to form a conductor connection 203. At this time, the two cables 20 are electrically connected, and then the semiconductor shielding layer outside the conductor connection 203 is restored.

[0097] After electrically connecting the first ends 201 and the second ends 202 of two sections of cables 20, a protective sleeve 130 is sleeved on the conductor connection 203. Subsequently, the conductor connection 203 is installed in the mold cavity 110 of the molding device 100, and a feeding device 200, a second cooling device 300, a circulating oil device 400, and a heating device 500 are respectively installed. The heating device 500 is connected to the two sections of cables 20, and the core conductors 204 of the two sections of cables 20 are heated according to the heating parameters, so as to increase the temperature of the conductor connection 203, facilitating the cross-linked polyethylene melt to coat the core conductor 204. During the extrusion process, the feeding device 200 evenly extrudes the cross-linked polyethylene melt into the mold cavity 110 through the connection channel 212 to evenly coat the outside of the conductor connection 203, so as to realize the injection of the cross-linked polyethylene melt into the mold cavity 110 of the molding device 100 through the feeding device 200.

[0098] During the extrusion molding process, the sealing device 600 is opened simultaneously to discharge the gas in the mold cavity 110 of the molding device 100. After the mold cavity 110 is filled with the cross-linked polyethylene melt, the sealing device 600 is closed to keep a certain pressure on the cross-linked polyethylene melt in the mold cavity 110. After a predetermined time, the fusion of the restored insulation layer and the interface of the body insulation layer is promoted. At this time, both ends of the molding die are sealed, which can ensure the pressure of the cross-linked polyethylene melt in the mold cavity 110, making the insulation layer and the body insulation layer fuse better. Subsequently, the circulating oil device 400 and the heating device 500 can heat the cross-linked polyethylene melt to make the cross-linked polyethylene fully cross-linked, ensuring the effect of cross-linking and vulcanization. At the same time, cooling water is passed through the first cooling device and the second cooling device 300 to cool the surfaces of the two sections of cables 20 near the molding area, avoiding scalding the cable 20 surfaces due to excessive temperature during the cross-linking and vulcanization process.

[0099] After cross-linking is completed, the conductor connection 203 and the cross-linked polyethylene form a submarine cable soft joint. The circulating oil device 400 and the heating device 500 are closed, and the cooling function of the circulating oil device 400 is turned on to cool down the molding device 100 and the submarine cable soft joint and ensure the consistency of cooling. The sealing device 600 is opened, and an air extraction pump (etc.) is connected to degas the submarine cable soft joint. After degassing is completed, the first exhaust pipe 710 and the second exhaust pipe 720 are connected to an inert gas source, and inert gas is introduced into the mold cavity 110. The inert gas takes away the cross-linking by-products. Subsequently, the molding device 100 is opened, the protective sleeve 130 is removed, and then the auxiliary device 800 is used to exhaust the insulation layer of the submarine cable soft joint again to take away the cross-linking by-products. After exhausting is completed, the outside of the submarine cable soft joint is trimmed, the outer shielding layer of the molded and cross-linked submarine cable soft joint is restored, and the external protection structure is restored.

[0100] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this specification.

[0101] The above-described embodiments merely represent several implementation manners of the present application. The description thereof is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patent application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the appended claims.

Claims

1. A forming die for a submarine cable soft joint, characterized in that For insulating extrusion and cross-linking at the conductor connection of two sections of cables, the forming die for the submarine cable flexible joint includes: A forming device having a die cavity. The conductor connection of the two sections of cables is located in the die cavity, and the remaining parts of the two sections of cables are exposed outside the forming device. The inner walls at both ends of the forming device are in sealed contact with the outer surfaces of the cables; A feeding device provided at one end of the forming device. The feeding device has a feeding channel, a connecting channel, and an annular channel. The annular channel is circumferentially provided on the inner wall of the feeding device and communicates with the die cavity. The connecting channel communicates the feeding channel with the annular channel; and A sealing device provided on the forming device and communicating with the die cavity. The sealing device can seal or open the die cavity; Wherein, the size of the end of the connecting channel communicating with the feeding channel is smaller than the size of the end connecting with the annular channel.

2. The forming die for the submarine cable flexible joint according to claim 1, wherein, The forming die for the submarine cable flexible joint further includes a first cooling device and a second cooling device. The first cooling device and the second cooling device are respectively provided at both ends of the forming die for cooling the outer surfaces of the cables; The first cooling device includes a first cooling housing, a first inlet joint, and a first outlet joint. The first inlet joint and the first outlet joint are provided on the first cooling housing and communicate with a first cooling water path inside the first cooling housing; The second cooling device includes a second cooling housing, a second inlet joint, and a second outlet joint. The second inlet joint and the second outlet joint are provided on the second cooling housing and communicate with a second cooling water path in the second cooling housing.

3. The forming die for the submarine cable soft joint according to claim 2, wherein The first cooling device is integrally provided in the feeding device, or the first cooling device is provided at one end of the feeding device away from the forming device.

4. The forming die for the submarine cable soft joint according to claim 1, characterized in that, The feeding device includes a feeding inner shell and a feeding outer shell. The feeding inner shell is fixed inside the feeding outer shell, and the connecting channel and the annular channel are provided in the feeding inner shell. The feeding channel is provided between the feeding outer shell and the feeding inner shell and penetrates to the outer wall of the feeding outer shell; And / or, the feeding device includes a first half shell and a second half shell. The first half shell and the second half shell are connected to enclose a first through hole for one of the cables to pass through. The first half shell has the feeding channel penetrating therein, and the connecting channel and the annular channel are provided in the first half shell and the second half shell.

5. The forming die for the submarine cable soft joint according to claim 1, wherein The forming device includes a die body and a protective sleeve. The die body has the die cavity, and the protective sleeve is provided on the inner wall of the die cavity. The core conductor connections of the two sections of cables are accommodated in the protective sleeve; Both ends of the die body have mating parts protruding towards the die cavity to abut against the outer surfaces of the cables, and / or the forming device further includes sealing members provided at both ends of the die body. The sealing members seal the connection between the inner wall of the die body and the outer walls of the cables.

6. The forming die for submarine cable flexible joint according to claim 5, characterized in that, The forming die for the submarine cable flexible joint further includes a circulating oil device which is arranged on the die body and used for heating or cooling the die body; The circulating oil device includes a temperature control device, a heat exchange pipeline, an inlet pipe, an outlet pipe and an oil storage tank. The heat exchange pipeline is wound around the outer side of the die body, or the heat exchange pipeline is integrally arranged in the die body. The inlet pipe and the outlet pipe are arranged at both ends of the heat exchange pipeline. The temperature control device is connected to the inlet pipe, and the oil storage tank is connected to the outlet pipe and the temperature control device.

7. The forming die for the submarine cable soft joint according to any one of claims 1 to 6, characterized in that, The forming die for the submarine cable flexible joint further includes a heating device which is connected to the outer side of the cable exposed out of the die cavity and used for heating the core conductor of the cable; The heating device includes a heating main machine and a heating component. The heating main machine is connected to the heating component, and the heating component is connected to the outer surface of the cable.

8. The forming die for the submarine cable flexible joint according to any one of claims 1 to 6, characterized in that, The sealing device includes a switching valve and a sealing component. The forming device has an exhaust groove communicating with the die cavity. The switching valve is arranged in the exhaust groove and used for sealing or opening the exhaust groove. The sealing component is arranged at the connection between the switching valve and the exhaust groove.

9. The forming die for the submarine cable soft joint according to any one of claims 1 to 6, characterized in that, The forming die for the submarine cable flexible joint further includes an exhaust device which is used for discharging crosslinking by-products generated by crosslinking vulcanization; The exhaust device includes an inert gas source, a first exhaust pipe and a second exhaust pipe. The first exhaust pipe and the second exhaust pipe are arranged at both ends of the forming device and communicated with the die cavity. The first exhaust pipe and the second exhaust pipe are respectively connected to the inert gas source; There is a preset phase difference in the circumferential direction of the forming die between the first exhaust pipe and the second exhaust pipe, and the range of the preset phase difference is 30° - 150°.

10. The forming die for the submarine cable flexible joint according to any one of claims 1 to 6, characterized in that, The forming die for the submarine cable flexible joint further includes an auxiliary device which is sleeved on the insulating layer at the conductor connection part after crosslinking vulcanization; The auxiliary device includes an auxiliary exhaust die and a heating element. The auxiliary exhaust die has a plurality of hollow parts, and the heating element is arranged in the auxiliary exhaust die and used for heating the auxiliary exhaust die.

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