Cable accessory interface breakdown voltage testing device

Abstract

The utility model discloses a cable accessory interface breakdown voltage testing device. The cable accessory interface breakdown voltage testing device comprises a conductor, a first shrinkage pipe, a second shrinkage pipe, a first electrode, a second electrode and voltage detection equipment. And the first shrinkage pipe wraps the outer wall of the conductor after being shrunk. And the second shrinkage pipe covers the outer wall of the first shrinkage pipe after being shrunk. The first electrode and the second electrode are arranged between the first shrinkage pipe and the second shrinkage pipe, and the first electrode and the second electrode are arranged at intervals in the axial direction. The voltage detection device is connected with the first electrode and the second electrode. According to the utility model, the interface breakdown voltage of the cable accessory can be rapidly, economically, effectively and accurately detected.

Description

Technical Field

[0001] This utility model relates to the technical field of power cable accessories, and in particular to a cable accessory interface breakdown voltage testing device. Background Technology

[0002] With the development of my country's economy and society, the country's overall electricity consumption has further increased, leading to a corresponding increase in the demand for power cable accessories. However, due to the prevalence of high-voltage power transmission, cable accessories are frequently subjected to significant electrical stress, making them highly susceptible to breakdown and power outages, impacting daily life and production. Currently, cable accessories are generally composed of multiple layers of material covering the conductor. Breakdown typically occurs between the interfaces of these multiple layers. Existing devices for testing the breakdown voltage at these interfaces require multiple layers of material to be stacked on a plane and pressurized using a pressurizing device to reduce the gaps between the layers and ensure accurate measurement. Therefore, existing devices for testing the breakdown voltage at these interfaces suffer from problems such as high cost, slow testing speed, large device size, and inaccurate results. Utility Model Content

[0003] The main objective of this invention is to provide a cable accessory interface breakdown voltage testing device, comprising:

[0004] conductor;

[0005] The first shrink tube, after shrinking, covers the outer wall of the conductor;

[0006] The second shrink tube, after shrinking, covers the outer wall of the first shrink tube;

[0007] A first electrode and a second electrode are disposed between the first contraction tube and the second contraction tube, and the first electrode and the second electrode are spaced apart along the axial direction.

[0008] A voltage detection device, wherein the voltage detection device is connected to the first electrode and the second electrode respectively.

[0009] Optionally, in one embodiment of the present invention, the first shrink tube is a heat shrink tube, and the second shrink tube is a heat shrink tube or a cold shrink tube.

[0010] Alternatively, the first shrink tube may be a cold-shrinkable material tube, and the second shrink tube may be a heat-shrinkable or cold-shrinkable tube.

[0011] Optionally, in one embodiment of the present invention, the first shrink tube and the second shrink tube are made of different materials.

[0012] Optionally, in one embodiment of the present invention, grease is provided between the first electrode and the first contraction tube and the second contraction tube, and between the second electrode and the first contraction tube and the second contraction tube.

[0013] Optionally, in one embodiment of the present invention, the grease completely covers the portions of the first electrode and the second electrode located in the first contraction tube and the second contraction tube.

[0014] Optionally, in one embodiment of the present invention, the first electrode includes a first head and a first connecting portion connected to the first head;

[0015] The second electrode includes a second head and a second connecting portion connected to the second head;

[0016] The first head and the second head are located between the first contraction tube and the second contraction tube, and the first head and the second head are arranged at a relative interval.

[0017] One end of the first connecting part and the second connecting part is located between the first shrink tube and the second shrink tube, and the other end of the first connecting part and the second connecting part are respectively connected to the voltage detection device.

[0018] Optionally, in one embodiment of the present invention, the edges of the first head and the second head are rounded.

[0019] Optionally, in one embodiment of the present invention, the first electrode and the second electrode are aluminum foil.

[0020] Optionally, in one embodiment of the present invention, both the first shrink tube and the second shrink tube are made of rubber, and the 10% elongation strength of the first shrink tube and the second shrink tube is 0.1-0.5 MPa.

[0021] Optionally, in one embodiment of the present invention, the conductor is one of iron, aluminum, copper, iron alloy, aluminum alloy, or copper alloy.

[0022] Optionally, in one embodiment of the present invention, the thickness of the first shrink tube after shrinkage is defined as a; in the unused state, the first shrink tube has a first inner diameter A1 before shrinkage and a second inner diameter A2 after shrinkage, the outer diameter of the conductor is B, and the second shrink tube has a third inner diameter C1 before shrinkage and a fourth inner diameter C2 after shrinkage.

[0023] The following relationship exists between the first inner diameter A1, the second inner diameter A2, and the conductor's outer diameter B:

[0024] A1>B and A2 <B;

[0025] The following relationship exists between the third inner diameter C1, the fourth inner diameter C2, and the conductor outer diameter B and thickness a:

[0026] C1>B+a and C2 <B。

[0027] Optionally, in one embodiment of this utility model, A2 = B - 10mm; C2 = B - 10mm.

[0028] Optionally, in one embodiment of this utility model, the thickness a = 1 mm.

[0029] This utility model of cable accessory interface breakdown voltage testing device, by setting a first retractable tube outside the conductor, setting a first electrode and a second electrode outside the first retractable tube, and setting a second retractable tube outside the first retractable tube and the first and second electrodes, reduces the gap between the interface of the first retractable tube and the second retractable tube by the pressure generated outside the conductor through the contraction of the first retractable tube and the contraction of the second retractable tube. This eliminates the need for pressurization equipment and makes the cable accessory cross-sectional breakdown voltage detection results faster, more economical, effective and accurate. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0031] Figure 1 This is a partial structural schematic diagram of an embodiment of the cable accessory interface breakdown voltage testing device of this utility model;

[0032] Figure 2 for Figure 1 Partial sectional view.

[0033] Explanation of icon numbers:

[0034] 11. Conductor; 12. First contraction tube; 13. Second contraction tube; 14. First electrode; 141. First head; 142. First connecting part; 15. Second electrode; 151. Second head; 152. Second connecting part.

[0035] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0036] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0037] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in this utility model embodiment are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0038] Furthermore, the use of terms such as "first" and "second" in this utility model is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the term "and / or" throughout the text includes three solutions; taking A and / or B as an example, it includes technical solution A, technical solution B, and a technical solution that simultaneously satisfies A and B. Furthermore, the technical solutions of various embodiments can be combined with each other, but this must be based on the ability of a person skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0039] With the development of my country's economy and society, the country's overall electricity consumption has further increased, leading to a corresponding increase in the demand for power cable accessories. However, due to the prevalence of high-voltage power transmission, cable accessories are frequently subjected to significant electrical stress, making them highly susceptible to breakdown and power outages, impacting daily life and production. Currently, cable accessories are generally composed of multiple layers of material covering the conductor. Breakdown typically occurs between the interfaces of these multiple layers. Existing devices for testing the breakdown voltage at these interfaces require multiple layers of material to be stacked on a plane and pressurized using a pressurizing device to reduce the gaps between the layers and ensure accurate measurement. Therefore, existing devices for testing the breakdown voltage at these interfaces suffer from problems such as high cost, slow testing speed, large device size, and inaccurate results.

[0040] In view of this, the present invention proposes a cable accessory interface breakdown voltage testing device. By setting a first retractable tube outside the conductor, setting a first electrode and a second electrode outside the first retractable tube, and setting a second retractable tube outside the first retractable tube, the pressure generated outside the conductor by the contraction of the first retractable tube and the contraction of the second retractable tube reduces the gap between the interface of the first retractable tube and the second retractable tube. This eliminates the need for pressurization equipment and makes the cable accessory cross-sectional breakdown voltage detection results faster, more economical, more effective, and more accurate.

[0041] To better understand the above technical solution, a detailed explanation of the technical solution is provided below with reference to the accompanying drawings.

[0042] like Figure 1-2 As shown, this utility model proposes a cable accessory interface breakdown voltage testing device, including a conductor 11, a first contraction tube 12, a second contraction tube 13, a first electrode 14, a second electrode 15, and a voltage detection device. The first contraction tube 12, after contraction, covers the outer wall of the conductor 11. The second contraction tube 13, after contraction, covers the outer wall of the first contraction tube 12. The first electrode 14 and the second electrode 15 are disposed between the first contraction tube 12 and the second contraction tube 13, and are spaced apart axially. The voltage detection device is connected to the first electrode 14 and the second electrode 15 respectively. This utility model can quickly, economically, effectively, and accurately detect the interface breakdown voltage of cable accessories.

[0043] As is understandable, cable accessories refer to various devices installed in cable lines to perform functions such as connection, branching, sealing, and protection of the cable lines. Cable accessories often require multiple layers of material to be coated on the conductor, and interface breakdown voltages can occur between these layers. By installing a first shrink tube 12 over the conductor 11, and a second shrink tube 13 over the first shrink tube 12, the conductor 11 simulates the conductor in the cable accessory, and the first and second shrink tubes 12 and 13 simulate the multiple layers of material coating the conductor. This allows for a more accurate simulation of the actual situation of the cable accessory in use, thus enabling more accurate detection of the interface breakdown voltage of the multiple layers of material in the cable accessory. Simultaneously, by simulating the multiple layers of material as the corresponding materials in the first and second shrink tubes 12 and 13, the radial pressure generated during the contraction of the first and second shrink tubes 12 and 13 reduces the gap between them, thus eliminating the need for a pressurization device and ensuring rapid, economical, effective, and accurate detection of interface breakdown voltage.

[0044] Understandably, the shape and material of conductor 11 can be set according to the shape and material of the conductor in the cable accessory product under test to simulate the cable accessory product to the greatest extent. Preferably, conductor 11 is cylindrical or tubular. Understandably, when the conductor in the cable accessory product under test is cylindrical, the multilayer material covering the conductor is also cylindrical. In this case, if the multilayer material is made into a plane according to the existing technology, and then pressure is applied to the multilayer material by a pressure-applying device to measure the breakdown voltage between the multilayer materials, the measured breakdown voltage will differ too much from the actual breakdown voltage. However, by selecting conductor 11 that is also cylindrical or tubular, and sequentially covering conductor 11 with a first shrink tube 12 and a second shrink tube 13, wherein the material of the first shrink tube 12 and the second shrink tube 13 is the same as that of the multilayer material, the first shrink tube 12 and the second shrink tube 13 also have a certain curvature like the cable accessory product under test, which can more closely resemble the actual situation of the multilayer material in the actual cable accessory product, making the detected interface breakdown voltage more accurate.

[0045] Understandably, the materials of conductor 11, first shrink tube 12, and second shrink tube 13 are consistent with the materials of the conductors and multilayer materials of the relevant cable accessory products. For example, when the cable accessory has three layers of multilayer material, and the three layers are silicone rubber, ethylene propylene rubber, and polyethylene from the inside out, then the first shrink tube 12 made of silicone rubber and the second shrink tube 13 made of ethylene propylene rubber can be selected. The first shrink tube 12 made of silicone rubber is sleeved on the outside of conductor 11 and shrinks on the outer wall of conductor 11. The second shrink tube 13 made of ethylene propylene rubber is sleeved on the outside of the first shrink tube 12 and the first electrode 14 and the second electrode 15, thereby detecting the interface breakdown voltage between silicone rubber and ethylene propylene rubber. Then, a first shrink tube 12 made of ethylene propylene rubber and a second shrink tube 13 made of polyethylene are selected. The first shrink tube 12 made of ethylene propylene rubber is placed on the outside of the conductor 11 and then shrinks to the outer wall of the conductor 11. The second shrink tube 13 made of polyethylene is placed on the outside of the first shrink tube 12, the first electrode 14, and the second electrode 15, thereby detecting the interface breakdown voltage between ethylene propylene rubber and polyethylene.

[0046] Furthermore, in one embodiment of the present invention, the first shrink tube 12 is a heat shrink tube, and the second shrink tube 13 is a heat shrink tube or a cold shrink tube; or, the first shrink tube 12 is a cold shrinkable material tube, and the second shrink tube 13 is a heat shrink tube or a cold shrink tube.

[0047] As is understandable, heat shrink tubing is a polymer material that shrinks when heated and is widely used in electronics, power, automotive, and communications fields for various purposes such as insulation, protection, and marking. Heat shrink tubing comes in a variety of materials, commonly including EVA (ethylene-vinyl acetate copolymer), PE (polyethylene), PVDF (polyvinylidene fluoride), PTFE (polytetrafluoroethylene), EPDM (ethylene propylene diene monomer rubber), FEP (perfluoroethylene), and silicone rubber, with an operating temperature range of -55℃ to 125℃. Cold shrink tubing, on the other hand, is a tubular material that shrinks at room temperature due to elastic recoil and is widely used in cable accessories, electrical equipment insulation, and sealing. The main materials for cold shrink tubing include silicone rubber, ethylene propylene diene monomer (EPDM), polyurethane (PU), nitrile rubber (NBR), and neoprene rubber (CR). The appropriate heat shrink tubing or cold shrink tubing material can be selected based on the specific requirements to detect the interface breakdown voltage between different materials.

[0048] Furthermore, in one embodiment of this utility model, the first shrink tube 12 and the second shrink tube 13 are made of different materials.

[0049] It is understandable that the materials of the first shrink tube 12 and the second shrink tube 13 can be the same or different. Of course, it is preferred that the materials of the first shrink tube 12 and the second shrink tube 13 are different, so that the interface breakdown voltage between different materials can be measured.

[0050] Furthermore, in one embodiment of the present invention, grease is provided between the first electrode 14 and the first contraction tube 12 and the second contraction tube 13, and between the second electrode 15 and the first contraction tube 12 and the second contraction tube 13.

[0051] It is understood that by providing grease between the first electrode 14 and the first contraction tube 12 and the second contraction tube 13, and between the second electrode 15 and the first contraction tube 12 and the second contraction tube 13, the conductivity of the first electrode 14 and the second electrode 15 can be improved, making the breakdown voltage measurement more accurate. Preferably, the grease completely covers the portions of the first electrode 14 and the second electrode 15 located in the first contraction tube 12 and the second contraction tube 13 to ensure the conductivity of the first electrode 14 and the second electrode 15.

[0052] Further, in one embodiment of the present invention, the first electrode 14 includes a first head 141 and a first connecting portion 142 connected to the first head 141; the second electrode 15 includes a second head 151 and a second connecting portion 152 connected to the second head 151; the first head 141 and the second head 151 are located between the first shrink tube 12 and the second shrink tube 13, and the first head 141 and the second head 151 are arranged at a distance from each other; one end of the first connecting portion 142 and the second connecting portion 152 is located between the first shrink tube 12 and the second shrink tube 13, and the other end of the first connecting portion 142 and the second connecting portion 152 are respectively connected to the voltage detection device.

[0053] Understandably, the first head 141 and the second head 151 are located between the first shrink tube 12 and the second shrink tube 13, and the first head 141 and the second head 151 are spaced apart. The first connecting part 142 and the second connecting part 152 are respectively connected to the voltage detection device. In this way, the voltage between the first electrode 14 and the second electrode 15 can be boosted by the voltage detection device, and the breakdown voltage can be measured.

[0054] Furthermore, in one embodiment of the present invention, the edges of the first head 141 and the second head 151 are rounded.

[0055] Understandably, by making the edges between the first head 141 and the second head 151 smooth, it is ensured that the edges of the first head 141 and the second head 151 have no sharp points, thereby further ensuring the accuracy of the breakdown voltage detection results. Understandably, the first electrode 14 and the second electrode 15 can be made of various materials, such as metal foil. Preferably, the first electrode 14 and the second electrode 15 are aluminum foil.

[0056] Furthermore, in one embodiment of the present invention, both the first shrink tube 12 and the second shrink tube 13 are made of rubber, and the 10% elongation strength of the first shrink tube 12 and the second shrink tube 13 is 0.1-0.5 MPa.

[0057] It can be understood that the 10% modulus at a specified elongation is the amount of load required to be applied per unit cross-sectional area when the elongation rate of the specimen reaches 10%. It is mainly affected by factors such as the chemical composition, molecular structure, and degree of crosslinking of the material. The greater the 10% modulus at a specified elongation of the first shrinkage tube 12 and the second shrinkage tube 13, the greater the pressure between the first shrinkage tube 12 and the conductor 11, and between the second shrinkage tube 13 and the first shrinkage tube 12. The smaller the 10% modulus at a specified elongation of the first shrinkage tube 12 and the second shrinkage tube 13, the smaller the pressure between the first shrinkage tube 12 and the conductor 11, and between the second shrinkage tube 13 and the first shrinkage tube 12. When the 10% modulus at a specified elongation of the first shrinkage tube 12 and the second shrinkage tube 13 is 0.1 - 0.5 Mpa, it can ensure that the pressure between the first shrinkage tube 12 and the conductor 11, and between the second shrinkage tube 13 and the first shrinkage tube 12 is within the optimal range, thereby ensuring no gap between the conductor 11, the first shrinkage tube 12, and the second shrinkage tube 13, so that the entire cable accessory interface breakdown voltage test device can accurately measure the interface breakdown voltage even without a pressure device. It can be understood that the conductor 11 can be composed of various materials. Preferably, the conductor 11 is one of iron, aluminum, copper, iron alloy, aluminum alloy, or copper alloy. It can be understood that the material of the conductor 11 can be the same as the material of the conductor in the cable accessory product.

[0058] Further, in an embodiment of the present invention, the thickness of the first shrinkage tube 12 after shrinkage is defined as a; in the unused state, the first shrinkage tube 12 has a first inner diameter A1 before shrinkage and a second inner diameter A2 after shrinkage, the outer diameter of the conductor 11 is B, the second shrinkage tube 13 has a third inner diameter C1 before shrinkage and a fourth inner diameter C2 after shrinkage; then the following relationships are satisfied among the first inner diameter A1, the second inner diameter A2, and the outer diameter B of the conductor 11: A1 > B and A2 < B; the following relationships are satisfied among the third inner diameter C1, the fourth inner diameter C2, the outer diameter B of the conductor 11, and the thickness a: C1 > B + a and C2 < B.

[0059] Understandably, the unused state refers to the state where the inner and outer walls of the first shrink tube 12 and the second shrink tube 13 are not fitted with any object. At this time, the first shrink tube 12 has a first inner diameter A1 before shrinking, and shrinks to a second inner diameter A2 after shrinking. Since the first inner diameter A1 is larger than the outer diameter B of the conductor 11, the first shrink tube 12 can be easily and quickly fitted onto the outer wall of the conductor 11 before shrinking. And since the second inner diameter A2 is smaller than the outer diameter of the conductor 11, the first shrink tube 12 can exert pressure on the conductor 11 after shrinking, thus ensuring a seamless fit between them. After the first shrink tube 12 shrinks outside the conductor 11, its overall diameter is the sum of the outer diameter B of the conductor 11 and the thickness a of the first shrink tube 12 after shrinking. Similarly, in the unused state, the second shrink tube 13 has a third inner diameter C1 before shrinking and a fourth inner diameter C2 after shrinking. Because the third inner diameter C1 is greater than the sum of the outer diameter B of conductor 11 and the thickness a of the first shrink tube 12 after shrinkage, the second shrink tube 13 can be easily and quickly fitted onto the outer wall of conductor 11. Because the fourth inner diameter C2 is smaller than the outer diameter B of conductor 11, after the second shrink tube 13 shrinks outside the first shrink tube 12, the second shrink tube 13 can generate radial pressure on the first shrink tube 12 and the second shrink tube 13, thereby ensuring that there are no gaps between conductor 11, the first shrink tube 12, and the second shrink tube 13. Preferably, A2 = B - 10 mm and C2 = B - 10 mm. It can be understood that A2 = B - 10 mm and C2 = B - 10 mm can ensure that conductor 11, the first shrink tube 12, and the second shrink tube 13 can be tightly attached to each other. Preferably, the thickness a of the first shrink tube 12 after shrinkage is 1 mm.

[0060] The cable accessory interface breakdown voltage testing device of this utility model obtains the machine tool voltage using the following steps:

[0061] Step 1: Install the first contraction tube 12 over the conductor 11;

[0062] Step 2: Tightly shrink the first shrink tube 12 onto the conductor 11;

[0063] Step 3: Place the first electrode 14 and the second electrode 15 at intervals outside the first contraction tube 12;

[0064] Step 4: Install the second contraction tube 13 over the structure formed in step 3;

[0065] Step 5: Tightly shrink the second shrink tube 13 outside the structure formed in step 3;

[0066] Step 6: Connect the first electrode 14 and the second electrode 15 to the voltage detection device respectively, and obtain and record the breakdown voltage value.

[0067] The specific structure of the cable accessory interface breakdown voltage testing device of this application refers to the above embodiments. Since this cable accessory interface breakdown voltage testing device adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be repeated here.

[0068] Understandably, when testing the interface breakdown voltage of cable accessories, a first shrink tube 12 is first placed over the conductor 11, and then the first shrink tube 12 is tightly contracted onto the conductor 11. Next, a first electrode 14 and a second electrode 15 are placed at intervals outside the first shrink tube 12, and a second shrink tube 13 is placed over the first shrink tube 12, the first electrode 14, and the second electrode 15; then the second shrink tube 13 is tightly contracted. Finally, the first electrode 14 and the second electrode 15 are connected to a voltage detection device to obtain and record the breakdown voltage value. Understandably, the voltage value at the point of breakdown can be directly used as the breakdown voltage value.

[0069] Furthermore, in one embodiment of this utility model, step 3 includes the following steps:

[0070] Step 3.1: Apply lubricating grease to the outer surface of the first shrink tube 12 at the locations where the first electrode 14 and the second electrode 15 are placed;

[0071] Step 3.2: Place the first electrode 14 and the second electrode 15 on the grease at intervals;

[0072] Step 3.3: Apply grease to the side of the first electrode 14 and the second electrode 15 away from the first constriction tube 12.

[0073] Understandably, by applying grease to the placement locations of the first electrode 14 and the second electrode 15 on the outer surface of the first shrink tube 12, and applying grease to the side of the first electrode 14 and the second electrode 15 away from the first shrink tube 12, the close contact between the first electrode 14, the second electrode 15 and the first shrink tube 12 and the second shrink tube 13 is further ensured, thereby improving the accuracy of the test results of the cable accessory interface breakdown voltage test device.

[0074] Furthermore, in one embodiment of this utility model, step 6 further includes the following steps:

[0075] Step 6.1: Connect the end of the first electrode 14 away from the second electrode 15 to the voltage detection device via a wire;

[0076] Step 6.2: The voltage boosting rate of the voltage detection device is set to 500-2000V / s;

[0077] Step 6.3: Turn on the switch to start boosting the voltage and obtain the breakdown voltage value.

[0078] It is understandable that a voltage ramp rate that is too fast will result in an overestimation of the detected breakdown voltage, while a voltage ramp rate that is too slow will result in an underestimation of the detected breakdown voltage. Setting the voltage ramp rate of the voltage detection device to 500-2000V / s can ensure that the final detected breakdown voltage value is more accurate.

[0079] Furthermore, in one embodiment of this utility model, the following steps are included after step 6.3:

[0080] 6.5 Remove the second shrink tube 13. When the breakdown position is located within the threshold range between the first electrode 14 and the second electrode 15, record the voltage value at the time of breakdown as the detection value.

[0081] 6.6 Repeat steps 4-6.5 until three sets of detection values ​​are obtained;

[0082] 6.7. Calculate the average of the three sets of detection values ​​obtained in step 6.6, and use the average value as the breakdown voltage value.

[0083] Understandably, when the breakdown location is within the threshold range between the first electrode 14 and the second electrode 15, it indicates that there are no gaps between the conductor 11, the first contraction tube 12, and the second contraction tube 13, and the pressure is appropriate. Using the breakdown voltage value at this time as the detection value can ensure the accuracy of the detection result. Understandably, the voltage value at a single breakdown can be used as the breakdown voltage value. Furthermore, to make the detection result more accurate, steps 4-6.5 can be repeated until three sets of detection values ​​are obtained; the average of the three sets of detection values ​​is then used as the breakdown voltage value.

[0084] The above description is only an optional embodiment of the present utility model and does not limit the patent scope of the present utility model. All equivalent structural transformations made under the concept of the present utility model and using the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included in the patent protection scope of the present utility model.

[0085] The above description is only an optional embodiment of the present utility model and does not limit the patent scope of the present utility model. All equivalent structural transformations made under the concept of the present utility model and using the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included in the patent protection scope of the present utility model.

Claims

1. A device for testing the interface breakdown voltage of cable accessories, characterized in that, include: Conductor (11); The first shrink tube (12) is wrapped around the outer wall of the conductor (11) after shrinking. The second shrink tube (13) is wrapped around the outer wall of the first shrink tube (12) after shrinking. A first electrode (14) and a second electrode (15) are disposed between the first contraction tube (12) and the second contraction tube (13), and the first electrode (14) and the second electrode (15) are spaced apart along the axial direction. A voltage detection device is connected to the first electrode (14) and the second electrode (15) respectively.

2. The cable accessory interface breakdown voltage testing device as described in claim 1, characterized in that, The first shrink tube (12) is a heat shrink tube, and the second shrink tube (13) is a heat shrink tube or a cold shrink tube; Alternatively, the first shrink tube (12) may be a cold-shrinkable material tube, and the second shrink tube (13) may be a heat-shrinkable or cold-shrinkable tube.

3. The cable accessory interface breakdown voltage testing device as described in claim 2, characterized in that, The first shrink tube (12) and the second shrink tube (13) are made of different materials.

4. The cable accessory interface breakdown voltage testing device as described in claim 1, characterized in that, Grease is provided between the first electrode (14) and the first contraction tube (12) and the second contraction tube (13), and between the second electrode (15) and the first contraction tube (12) and the second contraction tube (13).

5. The cable accessory interface breakdown voltage testing device as described in claim 4, characterized in that, The grease completely covers the portions of the first electrode (14) and the second electrode (15) located in the first constriction tube (12) and the second constriction tube (13).

6. The cable accessory interface breakdown voltage testing device as described in claim 1, characterized in that: The first electrode (14) includes a first head (141) and a first connecting portion (142) connected to the first head (141); The second electrode (15) includes a second head (151) and a second connecting portion (152) connected to the second head (151); The first head (141) and the second head (151) are located between the first contraction tube (12) and the second contraction tube (13), and the first head (141) and the second head (151) are arranged at a relative interval; One end of the first connecting part (142) and the second connecting part (152) is located between the first shrink tube (12) and the second shrink tube (13), and the other end of the first connecting part (142) and the second connecting part (152) are respectively connected to the voltage detection device.

7. The cable accessory interface breakdown voltage testing device as described in claim 6, characterized in that, The edges of the first head (141) and the second head (151) are rounded.

8. The cable accessory interface breakdown voltage testing device as described in claim 7, characterized in that, The first electrode (14) and the second electrode (15) are aluminum foil.

9. The cable accessory interface breakdown voltage testing device as described in claim 1, characterized in that, Both the first shrink tube (12) and the second shrink tube (13) are made of rubber, and the 10% elongation strength of the first shrink tube (12) and the second shrink tube (13) is 0.1-0.5 MPa.

10. The cable accessory interface breakdown voltage testing device as described in claim 1, characterized in that, The conductor (11) is one of iron, aluminum, copper, iron alloy, aluminum alloy or copper alloy.

11. A cable accessory interface breakdown voltage testing device as described in any one of claims 1-10, characterized in that, The thickness of the first shrink tube (12) after shrinkage is defined as a; in the unused state, the first shrink tube (12) has a first inner diameter A1 before shrinkage and a second inner diameter A2 after shrinkage, the outer diameter of the conductor (11) is B, and the second shrink tube (13) has a third inner diameter C1 before shrinkage and a fourth inner diameter C2 after shrinkage; The following relationship is satisfied between the first inner diameter A1, the second inner diameter A2, and the outer diameter B of conductor (11): A1>B and A2 <B; The third inner diameter C1, the fourth inner diameter C2, and the outer diameter B and thickness a of conductor (11) satisfy the following relationship: C1>B+a and C2 <B。 12. The cable accessory interface breakdown voltage testing device as described in claim 11, characterized in that, A2 = B - 10mm; C2 = B - 10mm.

13. The cable accessory interface breakdown voltage testing device as described in claim 12, characterized in that, Thickness a = 1 mm.

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