Plug-in type intermediate connecting device for cable

Abstract

The utility model relates to the technical field of cable connection, and discloses a plug-in type intermediate connecting device for cables, which comprises an intermediate joint, the intermediate joint comprises an insulating layer with a built-in conductor, the conductor is coaxial with the insulating layer, an accommodating cavity is formed in the conductor along the axial direction of the conductor, and wiring terminals are plugged at two opposite ends of the accommodating cavity. A connecting cavity is formed in one end, back on to the conductor, of the wiring terminal, a threaded hole communicated with the connecting cavity is formed in the outer wall of the wiring terminal, after the cable is stripped and cut according to the size, a cable core of the cable is in threaded connection with the threaded hole through a fastener, the cable is fastened in the connecting cavity, and an insulating layer and a shielding layer of the cable are connected with an insulating layer and a shielding layer of the middle connector. And quick connection of the cable is realized. According to the utility model, traditional methods such as cold shrinkage, thermal shrinkage, wrapping and welding are abandoned, a prefabricated structure is adopted, rapid connection of the cable is realized, installation is simple and convenient, fire operation is not needed, the cable is especially suitable for channels, underground and other occasions with high safety requirements, stripping and wrapping are not needed, and the installation speed is high.

Description

Technical Field

[0001] The utility model relates to the technical field of cable connection, in particular to a plug-in intermediate connection device for cables. Background Art

[0002] With the rapid progress of society and the continuous advancement of urbanization, the use of cables for power distribution has become the first choice for power distribution lines in developed cities due to the significant advantages of cables such as high reliability, small footprint, concealed laying, and little environmental impact. At present, the intermediate connectors of existing cable connections usually adopt structures such as welding, cold shrinkage, heat shrinkage, or wrapping, which cannot achieve fast cable connection, and it is also difficult to ensure the safety of cable power use, reducing the safety performance of cable power distribution. Utility Model Content

[0003] One of the main purposes of the utility model is to provide a plug-in intermediate connection device for cables, which aims to solve the technical problem that the existing intermediate connectors for cable connections usually adopt structures such as welding, cold shrinkage, heat shrinkage, or wrapping, and cannot achieve quick cable connection.

[0004] In order to achieve the above-mentioned purpose, the utility model provides a plug-in intermediate connection device for a cable, comprising an intermediate joint, the intermediate joint comprising an insulating layer, a conductor being embedded in the insulating layer, the conductor being coaxial with the insulating layer, an accommodating cavity being provided in the conductor along its own axial direction, the accommodating cavity passing through the opposite ends of the conductor, wiring terminals being plugged into the opposite ends of the accommodating cavity, a connecting cavity being provided at one end of the wiring terminal facing away from the conductor, the connecting cavity extending along the axial direction of the wiring terminal, a threaded hole being provided on the outer wall of the wiring terminal and passing through the connecting cavity, the wire core of the cable being threadedly connected to the threaded hole by a fastener to fasten the wire core in the connecting cavity.

[0005] Furthermore, the intermediate joint also includes an inner shielding layer arranged in the insulating layer and coaxial with the insulating layer, the inner wall of the inner shielding layer is in contact with the outer wall of the conductor, and an outer shielding layer is also arranged on the outer wall of the insulating layer.

[0006] Furthermore, the total length of the inner shielding layer is set to L1, the total length of the wiring terminal after plugging and matching with the conductor is set to L2, and the relationship between L1 and L2 should satisfy: L1>L2.

[0007] Furthermore, the total length of L1 is greater than that of L2 by no less than 10 mm.

[0008] Furthermore, stress cones are provided at opposite ends of the insulating layer. The stress cones extend along the axial direction of the insulating layer. The large end of the stress cone is close to the conductor, and the small end of the stress cone is far away from the conductor. The stress cone has a trumpet-shaped structure.

[0009] Furthermore, rounded corners are provided at the ends of the stress cone opposite to the two ports.

[0010] Furthermore, an isolation portion is provided in the accommodating cavity, and the isolation portion isolates the two wiring terminals.

[0011] Furthermore, the outer wall of the insulating layer is provided with a single-phase explosion-proof shell.

[0012] Furthermore, the conductor, the insulating layer, the inner shielding layer, the outer shielding layer and the stress cone are integrally formed.

[0013] Furthermore, the conductor and / or the terminal are made of copper or aluminum.

[0014] Compared with the prior art, the utility model has the following beneficial effects:

[0015] When using the plug-in intermediate connection device for cables of the utility model, it is only necessary to strip the cable according to the size, put the connection terminal on the core of the cable, so that the exposed core of the cable after stripping is located in the connection cavity of the connection terminal, and the fastener is threadedly connected with the threaded hole on the connection terminal, so that the core of the cable is fastened in the connection cavity, and the connection terminal and the core of the cable are locked; then the cable with the connection terminal is inserted into the accommodating cavity of the intermediate joint, so that the connection terminal and the accommodating cavity of the intermediate joint are plugged and fixed, and the insulation layer and shielding layer of the cable are connected with the insulation layer and shielding layer of the intermediate joint, and finally a single-phase explosion-proof shell is put on the outside of the intermediate joint and fixed and locked, so that the cable connection is completed. In summary, the utility model adopts a prefabricated structure to achieve rapid connection of the cable. Compared with the traditional cable connection intermediate connector adopting a structure such as welding, cold shrinkage, heat shrinkage or wrapping, the utility model realizes fast cable connection and is easy to install, without the need for fire, strip drawing, wrapping and other operations, and is suitable for occasions with high safety requirements such as trenches and underground. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic structural diagram of a plug-in intermediate connecting device for cables of the utility model;

[0017] Figure 2 It is an exploded view of the plug-in intermediate connecting device for cables of the utility model;

[0018] Figure 3 This is a schematic diagram of the structure of the connection between the intermediate joint and the conductor involved in the embodiment of the utility model;

[0019] Figure 4 This is a cross-sectional view of a conductor according to an embodiment of the utility model;

[0020] Figure 5This is a schematic diagram of the structure of the wiring terminal according to an embodiment of the utility model;

[0021] Figure 6 This is a cross-sectional view of a terminal block according to an embodiment of the utility model;

[0022] Figure 7 This is a schematic diagram of the structure of a conductive finger ring according to an embodiment of the utility model;

[0023] Figure 8 This is a schematic diagram of the structure of the elastic annular member according to an embodiment of the utility model;

[0024] Fig. 9 The utility model is a schematic diagram of the structure of the cable according to the embodiment of the present invention.

[0025] Reference numerals in the accompanying drawings:

[0026] 1. Intermediate joint; 10. Insulating layer; 101. Stress cone; 11. Inner shielding layer; 12. Outer shielding layer; 2. Conductor; 20. Accommodating cavity; 21. Mounting groove; 22. First limiting groove; 23. Isolation part; 3. Wiring terminal; 31. First shaft section; 310. Second limiting groove; 311. Guide structure; 32. Second shaft section; 320. Connecting cavity; 321. Threaded hole; 322. Anti-slip structure; 4. Conductive finger ring; 40. First fracture; 5. Elastic ring; 50. Second fracture; 6. Fastener; 7. Single-phase explosion-proof housing; 8. Cable; 80. Wire core. DETAILED DESCRIPTION

[0027] It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0028] In the description of the present invention, it should be understood that the terms "width", "up", "down", "front", "back", "top", "bottom", etc. indicating the orientation or position relationship are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention 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 cannot be understood as a limitation on the present invention.

[0029] In the description of the present utility model, it should be noted that, unless otherwise clearly specified and limited, the terms "install", "connect", "connect", and "set" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0030] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0031] Please refer to Figure 1-Figure 9 The utility model provides a plug-in intermediate connection device for a cable, comprising an intermediate joint 1, the intermediate joint 1 comprising an insulating layer 10, the insulating layer 10 having a conductor 2 therein, the conductor 2 being coaxial with the insulating layer 10, a receiving cavity 20 being provided in the conductor 2 along its own axial direction, the receiving cavity 20 penetrating through the opposite ends of the conductor 2, that is, the conductor 2 is a cylindrical structure, and the opposite ends of the receiving cavity 20 are detachably plugged with connecting terminals 3; wherein, one connecting terminal 3 is electrically connected to a core 80 of a cable 8, and another connecting terminal 3 is electrically connected to a core 80 of another cable 8; a connecting cavity 320 is provided at one end of the connecting terminal 3 facing away from the conductor 2, the connecting cavity 320 extending along the axial direction of the connecting terminal 3, a threaded hole 321 penetrating the connecting cavity 320 is provided on the outer wall of the connecting terminal 3, the core 80 of the cable 8 is threadedly connected to the threaded hole 321 through a fastener 6, and the core 80 of the cable 8 is fastened in the connecting cavity 320, so as to realize the connection and fixation between the cable 8 and the connecting terminal 3.

[0032] When using the plug-in intermediate connection device for cables of the utility model, it is only necessary to strip the cable 8 according to the size, insert the connection terminal into the core of the cable 8, so that the exposed core of the cable 8 after stripping is located in the connection cavity 320 of the connection terminal, and the fastener 6 is threadedly connected with the threaded hole 321 on the connection terminal, so that the core of the cable 8 is fastened in the connection cavity 320, and the connection terminal and the core of the cable 8 are locked; then the cable 8 with the connection terminal is inserted into the accommodating cavity 20 of the intermediate joint 1, so that the connection terminal and the accommodating cavity 20 of the intermediate joint 1 are plugged and fixed, and the cable 8 is connected. In summary, the utility model adopts a prefabricated structure to achieve rapid connection of the cable 8. Compared with the traditional intermediate connection of the cable 8, which adopts a structure such as welding, cold shrinkage, heat shrinkage or wrapping, the utility model realizes the connection of the cable 8 quickly and is easy to install, without the need for fire, strip drawing, wrapping and other operations, and is suitable for occasions with high safety requirements such as trenches and underground.

[0033] It should be noted that there is no limit to the number of threaded holes 321. Of course, the number of threaded holes 321 is the same as that of fasteners 6, and they correspond one to one. Fasteners 6 are bolts. Of course, in order to provide reliable locking force and prevent loosening, the connection position between the fasteners 6 and the core of the cable 8 can be ground flat.

[0034] In one embodiment, the terminal 3 includes a first shaft segment 31 and a second shaft segment 32 connected end to end, and the terminal 3 is plugged into the accommodating cavity 20 through the first shaft segment 31; the connecting cavity 320 is opened on the second shaft segment 32, and of course, the threaded hole 321 is also opened on the second shaft segment 32, and an anti-slip structure 322 is arranged in the connecting cavity 320. The anti-slip structure 322 is an anti-slip thread, which is used to increase the friction between the core of the cable 8 and the terminal 3, and further prevent the cable 8 from detaching from the terminal 3.

[0035] In one embodiment, the intermediate joint 1 further includes an inner shielding layer 11 disposed in the insulating layer 10 and coaxial with the insulating layer 10, the inner wall of the inner shielding layer contacts the outer wall of the conductor 2, and an outer shielding layer 12 is further disposed on the outer wall of the insulating layer 10. The inner shielding layer and the outer shielding layer 12 play a role in balancing the electric field distribution, avoiding electric field concentration, and facilitating the safe transmission of power in the cable 8.

[0036] In one embodiment, since the inner wall of the inner shielding layer 11 is in physical contact with the conductor 2, and the conductor 2 is directly connected to the core of the cable 8, the conductor 2 and the inner shielding layer 11 are both at high potential. In order to prevent the material from partial discharge or accelerated aging due to excessive concentration of electric field strength, rounded corners are set at the ends of the opposite ends of the inner shielding layer 11 to prevent electric field concentration or electric field distortion. Furthermore, the opposite ends of the inner shielding layer 11 are in a trumpet-shaped structure, which can further avoid electric field concentration or electric field distortion on the inner shielding layer 11.

[0037] It should be noted that the end fillets of the opposite end ports of the inner shielding layer 11 cannot be too small, otherwise it is difficult to process and has little significance for balancing the electric field. Of course, they cannot be too large, otherwise the inner shielding layer 11 uses too much material, which is not conducive to cost control. The fillet size is preferably R1 to R3 mm. In addition, since the conductor 2 is inside the inner shielding layer 11 and is protected by the electric field shielding, the surface electric field distribution of the conductor 2 does not need to be designed separately, and only the portable reliability of production, processing, and installation needs to be considered; in addition, in order to ensure that the conductor 2 and the inner shielding layer 11 are in a close and reliable physical contact state to prevent displacement during installation and use, the outer surface of the conductor 2 can be sandblasted to increase the outer surface roughness of the body, and after the coupling agent is applied, it can be molded together with the inner shielding layer 11.

[0038] Of course, the thickness of the inner shielding layer 11 is related to the design voltage, material, and electric field distribution. The design principle is that the higher the voltage, the thicker the thickness; the higher the breakdown voltage of the material, the thinner the thickness; the more uniform the electric field distribution, the thinner the thickness; and vice versa. For example, if the design voltage is 10kV, the material is EPDM, and the electric field distribution is uniform and reasonable, then 8mm is selected as the appropriate value for the thickness of the inner shielding layer 11. If the conditions change, corresponding adjustments can be made according to the above design principles; the thickness of the outer shielding layer 12 is preferably 1 to 3mm.

[0039] In one embodiment, the total length of the inner shielding layer 11 is set to L1, and the total length after the connection terminal 3 and the conductor 2 are plugged in is set to L2, then the satisfying relationship between L1 and L2 should be: L1>L2, so that the electric field shielding effect can be achieved. Of course, in order to achieve a good electric field shielding effect, the total length of L1 is not less than 10mm greater than L2. In addition, in order to improve the installation misalignment caused by stripping deviation and differentiated construction, the length of the inner shielding layer 11 can be designed to be longer. The specific length design can be adjusted according to the above design principles and actual conditions, and is not limited here.

[0040] In one embodiment, stress cones 101 are provided at opposite ends of the insulating layer 10. The stress cones 101 extend along the axial direction of the insulating layer 10. The large end of the stress cone 101 is close to the conductor 2, and the small end of the stress cone 101 is far away from the conductor 2. Of course, the stress cone 101 can be sleeved on the cable 8, that is, when the intermediate connection device of the utility model realizes the electrical connection of the two cables 8, the inner wall of the stress cone 101 contacts the outer wall of the cable 8. Specifically, the stress cone 101 has a trumpet-shaped appearance, and the inner cylindrical part of the stress cone 101 is in physical contact with the fracture of the outer shielding layer of the cable 8. The electric field concentrated at the fracture of the outer shielding layer of the cable 8 is stress-dissipated by the taper of the stress cone 101. Of course. The outer wall of the small end of the stress cone 101 is also in contact with the outer shielding layer 12, which can further enhance the effect of stress dissipation.

[0041] In addition, in order to achieve good stress relief and prevent performance degradation due to stripping and installation deviation, the break position of the outer shielding layer of the cable 8 should be located at the midpoint of the inner cylindrical part of the stress cone 101. The size of the trumpet-shaped appearance of the stress cone 101 is positively correlated with the voltage. The higher the voltage, the larger the trumpet should be designed. In order to enable the stress cone 101 to effectively relieve stress, the ends of the large port and the small port of the stress cone 101 are both rounded, which is conducive to stress relief.

[0042] Of course, the conductor, insulation layer, inner shielding layer, outer shielding layer and stress cone in the middle head are integrally formed, that is, the conductor, insulation layer, inner shielding layer, outer shielding layer and stress cone are integrally formed in the mold, which is conducive to the processing and forming of the middle head; and the process of how the conductor, insulation layer, inner shielding layer, outer shielding layer and stress cone are integrally formed in the mold belongs to the existing technology and will not be explained here.

[0043] In one embodiment, an isolation portion 23 is provided in the accommodating cavity 20, and the isolation portion 23 isolates the wiring terminals 3 plugged in at opposite ends of the accommodating cavity 20. That is, it can be understood that the isolation portion 23 realizes a physical separation between the two wiring terminals 3, prevents water vapor from being transmitted along the core of the cable 8 to the core of another cable 8, realizes water blocking of the core, ensures stable and reliable waterproof performance at the connection of the cable 8, and greatly improves the safe operation of the entire distribution line.

[0044] In one embodiment, the outer wall of the insulating layer 10 is provided with a single-phase explosion-proof housing 7, which can prevent interphase short circuit, avoid energy accumulation, prevent the formation of an explosive environment, and effectively improve the safety performance of the intermediate joint 1 under abnormal conditions to prevent accidents from expanding. The material of the single-phase explosion-proof housing 7 is required to be conductive, light, and cheap, preferably aluminum alloy, carbon fiber, stainless steel, etc.

[0045] In one embodiment, in order to achieve quick installation and reliable fixation, an anti-loosening structure is provided at the connection between the intermediate joint 1 and the terminal 3. The anti-loosening structure is described in detail below: at least one conductive contact finger ring 4 is provided in the accommodating cavity 20, and at least one elastic ring member 5 is also provided in the accommodating cavity 20; the first shaft segment 31 of the terminal 3 is interference fit with the inner ring of the elastic ring member 5, and the outer wall of the first shaft segment 31 is in contact with the inner ring of the conductive contact finger ring 4; the gap between the outer wall of the first shaft segment 31 and the inner wall of the accommodating cavity 20 is preferably 0.2-1mm, and the gap between the outer wall of the first shaft segment 31 and the inner wall of the accommodating cavity 20 in this embodiment is 0.2mm; in other embodiments, the gap between the outer wall of the first shaft segment 31 and the inner wall of the accommodating cavity 20 is 1mm.

[0046] In one embodiment, a guide structure 311 is provided at the end of the first shaft section 31 facing away from the second shaft section 32, and the guide structure 311 is used to guide the first shaft section 31 to insert into the conductive contact finger ring 4 and the elastic ring member 5. Under the action of the guide structure 311, the terminal 3 can quickly and smoothly pass through the conductive contact finger ring 4 and the elastic ring member 5. Specifically, the guide structure 311 includes but is not limited to a rounded corner structure or a chamfered corner structure of the end surface edge of the first shaft section 31 facing away from the second shaft section 32, wherein the size of the rounded corner structure is preferably R3-R5mm, and the size of the chamfered corner structure is preferably 3-5mm; if the guide structure 311 is a rounded corner structure, the size of the rounded corner structure in this embodiment is R3mm; in other embodiments, the size of the rounded corner structure is R5mm; if the guide structure 311 is a chamfered corner structure, the size of the chamfered corner structure in this embodiment is 3mm; in other embodiments, the size of the chamfered corner structure is 5mm.

[0047] In one embodiment, the function of the conductive contact finger ring 4 is to electrically connect the connection terminal to the conductor 2. The outer wall of the first shaft segment 31 is interference fit with the inner ring of the conductive contact finger ring 4, which can further prevent the connection terminal 3 from being loosened from the conductor 2. Specifically, the outer diameter of the first shaft segment 31 is larger than the inner diameter of the conductive contact finger ring 4 to achieve an interference fit between the first shaft segment 31 and the conductive contact finger ring 4; wherein the interference between the first shaft segment 31 and the conductive contact finger ring 4 is preferably 1-4 mm, and in this embodiment, the interference between the first shaft segment 31 and the conductive contact finger ring 4 is 1 mm, and in other embodiments, the interference between the first shaft segment 31 and the conductive contact finger ring 43 is 4 mm.

[0048] In summary, it can be understood that the above-mentioned anti-loosening structure ensures that the terminal 3 and the conductor 2 will not loosen by achieving interference fit between the first shaft section 31 of the terminal 3 and the elastic ring 5 and the conductive contact finger ring 4.

[0049] Of course, in order to prevent the interference fit between the first shaft section 31 of the terminal 3 and the elastic ring 5 and the conductive contact finger ring 4, which will increase the installation resistance between the terminal 3 and the conductor 2, and to prevent the installation resistance from being too large, which will cause the installation to be difficult or even impossible to install, the first fracture 40 that penetrates the inner and outer rings of the conductive contact finger ring 4 is provided on the conductive contact finger ring 4 in this embodiment, that is, the first fracture 40 penetrates the inner and outer rings of the conductive contact finger ring 4, so that the conductive contact finger ring 4 has a certain elastic deformation ability. In summary, it can be understood that when the first shaft section 31 passes through the conductive contact finger ring 4, under the force exerted by the outer wall of the first shaft section 31 on the inner ring of the conductive contact finger ring 4, the first fracture 40 of the conductive contact finger ring 4 will open slightly, so that the conductive contact finger ring 4 has a clamping force on the outer wall of the first shaft section 31, so as to achieve the locking between the conductor 2 and the terminal 3, and further prevent the conductor 2 from being loosened from the terminal 3. At the same time, it can also ensure that the first shaft section 31 of the terminal 3 is in close contact with the conductive contact finger ring 4 and the current carrying capacity meets the requirements.

[0050] In one embodiment, a mounting groove 21 for mounting the conductive contact finger ring 4 is provided along the circumference of the accommodating cavity 20, and the mounting groove 21 can facilitate the mounting and fixing of the conductive contact finger ring 4. Specifically, the inner diameter of the mounting groove 21 is smaller than the outer diameter of the conductive contact finger ring 4 in a relaxed state (the conductive contact finger ring 4 in a relaxed state refers to the state in which the conductive contact finger ring 4 is not clamped with the first shaft section 31), so as to achieve interference fit between the mounting groove 21 and the conductive contact finger ring 4, thereby preventing the conductive contact finger ring 4 from detaching from the mounting groove 21.

[0051] In one embodiment, a first limiting groove 22 adapted to the elastic ring 5 is provided in the accommodating cavity 20 along its own circumference, and a second limiting groove 310 adapted to the elastic ring 5 is provided on the outer wall of the first shaft section 31 along its own circumference, the first limiting groove 22 corresponds to the second limiting groove 310, the elastic ring 5 is sleeved on the first shaft section 31, and the elastic ring 5 is located in the first limiting groove 22 and the second limiting groove 310. Specifically, it can be understood that the inner diameter of the first limiting groove 22 is slightly smaller than the outer diameter of the elastic ring 5, and the outer diameter of the second limiting groove 310 is slightly larger than the inner diameter of the elastic ring 5 in a relaxed state (referring to the state in which the elastic ring 5 is not self-locking the first shaft section 31), so that the elastic ring 5 is located in the first limiting groove 22 and the second limiting groove 310 on opposite sides of the radial direction when the connection terminal 3 and the conductor 2 are locked by the squeezing force of the elastic ring 5 itself on the outer wall of the first shaft section 31.

[0052] In one embodiment, the elastic ring 5 is provided with a second break 50 that penetrates the inner and outer rings of the elastic ring 5, that is, the second break 50 penetrates the inner and outer rings of the elastic ring 5, so that the first shaft section 31 of the terminal 3 can more conveniently pass through the elastic ring 5. Specifically, the angle range of the second break 50 can be 3 to 10 degrees, and the second break 50 is a space for the elastic ring 5 to be squeezed and deformed by force. When the first shaft section 31 passes through the elastic ring 5, the elastic ring 5 is stretched and deformed by force. When the first shaft section 31 is plugged into place, the elastic ring 5 is fixed between the first limiting groove 22 and the second limiting groove 310, and the interference of the elastic ring 5 disappears, and the stress deformation shrinks to the relaxed state, and the self-locking and anti-loosening function is realized at the same time.

[0053] In one embodiment, for example, two conductive finger rings 4 and two elastic rings 5 ​​are provided, and the two conductive finger rings 4 are located between the two elastic rings 5, that is, it can be understood that when the connection terminal 3 is connected and locked with the conductor 2, the two elastic rings 5 ​​are respectively located at opposite ends of the outer wall of the first shaft section 31, and the two conductive finger rings 4 are located in the middle of the outer wall of the first shaft section 31, so that the connection terminal 3 and the conductor 2 can be further prevented from being loosened. Of course, in other embodiments, the conductive finger rings 4 and the elastic rings 5 ​​can also be set to three or four, which is not limited here, that is, the number of the conductive finger rings 4 and the elastic rings 5 ​​can be reasonably changed according to the specifications of different cables 8.

[0054] It should be noted that the circumferential surface of the first shaft section 31 of the terminal block 3 is a current flow surface for transmitting current, and its effective cross-sectional area should not be less than the cross-sectional area of ​​a connecting pipe of the same specification specified in GB / T 14315.

[0055] In one embodiment, in order to meet the current carrying capacity requirements of the conductor 2 of the cable 8 and ensure that it can resist electrochemical corrosion during use, the conductor 2 is made of copper or aluminum material, and the terminal 3 is made of copper or aluminum material. The specific selection should be consistent with the actual cable 8 conductor 2. In order to prevent electrochemical corrosion or oxidation during use, the surface of the conductor 2 and the terminal 3 can be electroplated or conductively passivated; the material of the elastic ring 5 is preferably made of spring steel, and the surface of the elastic ring 5 is subjected to anti-oxidation treatment. After the elastic ring 5 is formed, it is demagnetized to prevent eddy current heating during use; the material of the conductive finger ring 4 is preferably beryllium bronze or chromium zirconium copper, and the surface is tinned or silver-plated with a coating thickness of 2-5um; the material of the bolt is preferably stainless steel.

[0056] In one embodiment, the conductor 2 and the connecting terminal material are required to have high conductivity and oxidation resistance, and the material is preferably copper / aluminum. The surface is electroplated, and the thickness of the coating is preferably 2 to 5 um; the fastener 6 is required to have high strength, oxidation resistance, and electromagnetic interference resistance, and the material is preferably stainless steel; the inner shielding layer 11, the stress cone 101, and the outer shielding layer 12 are required to have high plasticity, good elasticity, and the ability to balance the electric field. The material is preferably semi-conductive silicone rubber / ethylene propylene diene rubber, and its volume resistivity is ≤100Ω·cm, the tensile strength is ≥4N / mm2, and the Shore hardness is preferably HA40-60; the insulating layer 13 is required to have high plasticity, good resilience, and good insulation, and its tensile strength is ≥6N / mm2, and the volume resistivity is ≥1*10 15 Ω·cm, breakdown strength should be ≥20kV / mm.

[0057] Of course, since the cable 8 is generally in a maintenance-free state after connection, in order to ensure that the connecting device of the utility model has the same service life as the cable 8 and ensure safe and reliable performance during use, and to prevent stratification or degradation of materials due to the "breathing effect" of the cable 8 under load changes, the materials of the inner shielding layer 11, insulating layer 10, stress cone 101, and outer shielding layer 12 of the connecting device shall have a standard aging condition of 135°C±3°C for 7d as specified in the "T / CEC 120-2016 Technical Specifications for Prefabricated Cable 8 Accessories with Rated Voltage of 35kV (Um=40.5kV) and Below" standard, and the change rate of their tensile strength and elongation shall be ≤30%.

[0058] In summary, by adopting the connection device of the utility model, the entire cable 8 connection process does not require fire or expansion, has low professional requirements for installers, has simple steps, and is quick to install, which can greatly shorten the installation time and reduce the power outage time for emergency repair and power restoration; at the same time, the isolation portion 23 inside the conductor 2 can prevent water vapor from being transmitted along the core of the cable 8 to the core of another cable 8; the single-phase explosion-proof casing 7 can prevent phase-to-phase short circuits, avoid energy accumulation, and prevent the formation of an explosive environment, effectively improving the waterproof and explosion-proof capabilities, and greatly improving the safety of the power distribution of the cable 8.

[0059] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A plug-in intermediate connection device for a cable, characterized in that: The invention comprises an intermediate joint, wherein the intermediate joint comprises an insulating layer, wherein a conductor is embedded in the insulating layer, wherein the conductor is coaxial with the insulating layer, wherein an accommodating cavity is provided in the conductor along its own axial direction, wherein the accommodating cavity passes through the opposite ends of the conductor, wherein wiring terminals are plugged into the opposite ends of the accommodating cavity, wherein a connecting cavity is provided at one end of the wiring terminal facing away from the conductor, wherein the connecting cavity extends along the axial direction of the wiring terminal, wherein a threaded hole which passes through the connecting cavity is provided on the outer wall of the wiring terminal, wherein the wire core of the cable is threadedly connected to the threaded hole by a fastener so as to fasten the wire core in the connecting cavity.

2. The plug-in intermediate connection device for cables according to claim 1, characterized in that: The intermediate joint also includes an inner shielding layer which is arranged in the insulating layer and is coaxial with the insulating layer. The inner wall of the inner shielding layer contacts the outer wall of the conductor. An outer shielding layer is also arranged on the outer wall of the insulating layer.

3. The plug-in intermediate connection device for cables according to claim 2, characterized in that: The total length of the inner shielding layer is set to L1, and the total length of the wiring terminal after plugging and matching with the conductor is set to L2. The relationship between L1 and L2 should satisfy: L1>L2.

4. The plug-in intermediate connection device for cables according to claim 3, characterized in that: The total length of L1 is greater than that of L2 by no less than 10 mm.

5. The plug-in intermediate connection device for cables according to claim 1 or 2, characterized in that: Stress cones are arranged at opposite ends of the insulating layer. The stress cones extend along the axial direction of the insulating layer. The large end of the stress cone is close to the conductor, and the small end of the stress cone is far away from the conductor. The stress cone has a trumpet-shaped structure.

6. The plug-in intermediate connection device for cables according to claim 5, characterized in that: The ends of the stress cone opposite to the two ports are provided with rounded corners.

7. The plug-in intermediate connection device for cables according to claim 1, characterized in that: An isolation portion is provided in the accommodating cavity, and the isolation portion isolates the two connecting terminals.

8. The plug-in intermediate connection device for cables according to claim 1, characterized in that: The outer wall of the insulating layer is provided with a single-phase explosion-proof shell.

9. The plug-in intermediate connection device for cables according to claim 5, characterized in that: The conductor, the insulating layer, the inner shielding layer, the outer shielding layer and the stress cone are integrally formed.

10. The plug-in intermediate connection device for cables according to claim 1, characterized in that: The conductor and / or the connecting terminal are made of copper or aluminum.

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