Withstand voltage test device for cable

Abstract

The invention relates to the technical field of cable tests, in particular to a withstand voltage test device for a cable. Comprising a folding frame; the isolation shell is fixedly connected to the folding frame, and a through hole is formed in the isolation shell; the first fixing frame is fixedly connected into the isolation shell, a fixing rod is fixedly connected into the isolation shell, the first fixing frame and the fixing rod are both provided with mounting rods distributed in a circumferential array mode, the first fixing frame is fixedly connected with first electric push rods distributed in a circumferential array mode, the mounting rods are fixedly connected with clamping shells, and the clamping shells are fixedly connected with the first electric push rods. The clamping shell is slidably connected with a conducting strip, the clamping shell is fixedly connected with a first fixing shell which is distributed in a mirror image mode, and the first fixing shell is fixedly connected with a first liquid bag. The conducting strip is extruded through the first liquid bag, so that the conducting strip is adaptively wrapped according to the specific shape of the conducting strip when the conducting strip is connected with the test cable, the possibility of air breakdown between the conducting strip and the test cable is reduced, and the test safety is improved.

Description

Technical Field

[0001] The invention relates to the technical field of cable testing, and in particular to a voltage withstand testing device for cables. Background Art

[0002] The cable DC withstand voltage test is an important test method for evaluating the insulation performance of cables. It detects whether the cable has potential insulation defects by applying a DC voltage higher than the normal operating voltage to ensure its safety and reliability in actual operation.

[0003] During the cable laying process, in order to ensure that the insulation performance of each section of cable meets the requirements, a withstand voltage test is required before making the joint. The current industry-wide common cable withstand voltage test process mainly includes the following operating procedures: first, pre-treat the cable end and remove the terminal insulation sheath layer by mechanical stripping; then physically separate the three-phase cable (A, B, and C phases); finally, use a high-voltage generator to directly connect to the cable metal core for a withstand voltage test. However, in traditional processes, there is a mechanical fit gap when the test connector of the high-voltage generator is connected to the cable metal core. When high voltage is applied during the test, the electric field strength at the gap will increase sharply. According to Baschen's law, when the gap field strength reaches the air dielectric breakdown threshold, it will cause the following chain reaction: Ionization of the air dielectric produces a partial discharge phenomenon (i.e., air breakdown); The ionized region forms a low-impedance conductive channel; The discharge current induces the Joule heating effect, causing a sudden rise in local temperature; This phenomenon will directly lead to two serious consequences: first, the transient overvoltage generated by the discharge may damage the test equipment, posing a serious safety risk; second, the abnormal discharge during the test will interfere with the collection of the actual withstand voltage data, causing deviations in the test results and significantly reducing the reliability of the test system. Summary of the invention

[0004] In order to overcome the above disadvantages, the present invention provides a voltage withstand test device for cables.

[0005] Technical solution: A voltage withstand test device for cables, comprising: Folding rack; An isolation shell is fixedly connected to the folding frame, and a through hole is provided on the isolation shell; A first fixed frame is fixedly connected in the isolation shell, a fixed rod is fixedly connected in the isolation shell, the first fixed frame and the fixed rod are both provided with mounting rods distributed in a circumferential array, a first electric push rod distributed in a circumferential array is fixedly connected to the first fixed frame, the telescopic end of the first electric push rod is fixedly connected to the adjacent mounting rod, the mounting rod is fixedly connected to a clamping shell, the clamping shell is slidably connected with a conductive sheet, tension springs are provided on both sides of the conductive sheet and between the adjacent clamping shells, the clamping shell is fixedly connected with a first fixed shell distributed in a mirror image, the first fixed shell is fixedly connected with a first liquid capsule, the first liquid capsule is used to squeeze and wrap the conductive sheet, a control mechanism is provided in the first liquid capsule, the control mechanism is used to control the flattening and expansion sequence of the first liquid capsule.

[0006] Preferably, the control mechanism comprises: A separator, fixedly connected to the first liquid bag; A pressure valve is fixedly connected to a side of the partition away from the first fixed shell, and the length of the first liquid capsule on the axis of the fixed rod is greater than the length of the conductive sheet on the axis of the fixed rod, and a one-way valve is arranged on a side of the partition close to the adjacent first fixed shell; The transmission assembly is arranged on the clamping shell and is used to provide pressure for the first liquid bag when the conductive sheet clamps the cable.

[0007] Preferably, the transmission assembly comprises: A spring telescopic rod is fixedly connected to the clamping shell, a fixing portion of the spring telescopic rod is fixedly connected to the mounting rod, and the first fixing shells distributed in a mirror image are both connected to the fixing portion of the spring telescopic rod through a pipeline; The second fixing frame is fixedly connected to the telescopic end of the spring telescopic rod, and the second fixing frame is fixedly connected to a second liquid bag, and the second liquid bag is used to squeeze the conductive sheet.

[0008] Preferably, the isolation shell is threadedly connected with a sealing cover, the sealing cover is slidably connected to the fixing rod, and the isolation shell and the sealing cover are both made of insulating material.

[0009] As a preference, it also includes: A switching mechanism is provided on the fixing rod and is used to switch the electrodes of the test cable. The switching mechanism comprises: A conductive frame, fixedly connected to the fixing rod, and the conductive frame is fixedly connected to the first fixing frame; A rotating ring is rotatably connected to the fixed rod, and the conductive frame and the rotating ring are both provided with conductive blocks distributed in a circumferential array, and the conductive blocks on the conductive frame and the conductive blocks on the rotating ring are used for contact and conduction; The power assembly is arranged on the fixing rod and is used to control the relative rotation angle between the conductive frame and the rotating ring.

[0010] Preferably, the rotating ring is provided with conductive rods, and the rotating ring is provided with discharge rods distributed in a mirror image.

[0011] Preferably, the power assembly comprises: A second electric push rod is fixedly connected to the fixing rod; A spline rod, spline-connected in the fixing rod, the spline rod being fixedly connected to the telescopic end of the second electric push rod; The first extrusion rod is fixedly connected to the rotating ring. The fixed rod is provided with an arc-shaped through groove for the first extrusion rod to pass through. The spline rod is provided with an inclined groove. The first extrusion rod slides in the inclined groove on the spline rod.

[0012] As a preference, it also includes: A discharge mechanism is provided on the fixed rod and is used to switch the discharge mode of the discharge rod. The discharge mechanism includes: A fixing ring is rotatably connected to the fixing rod, and the conducting rod and the discharging rod are both fixedly connected to the fixing ring; The resistor blocks distributed in mirror image are respectively connected to the adjacent discharge rods in a sliding manner, the resistor block is fixedly connected to a first conductive member, the discharge rod is fixedly connected to a second conductive member, the second conductive member slides in the resistor block and the first conductive member, and the resistor block and the first conductive member are fixedly connected to a sliding shell; A switching component is arranged on the fixing rod and is used for changing the relative position of the resistance block and the second conductive member.

[0013] Preferably, the switching component comprises: An extrusion frame is fixedly connected to the fixed rod, and the sliding shell is fixedly connected to a second extrusion rod, and the second extrusion rod is used to drive the sliding shell to move by extruding the extrusion frame; The delay component is arranged on the fixing ring and is used for controlling the resistance block to reset slowly.

[0014] Preferably, the delay component comprises: The second fixed shells distributed in a mirror image are all fixed to the fixed ring, the sliding shell is fixed with a sliding rod, the sliding rod is slidably connected to the second fixed shell, a spring is arranged between the second fixed shell and the sliding rod, a plurality of through holes are arranged on the sliding rod, and a one-way valve is arranged in each of the through holes on the sliding rod.

[0015] The beneficial effects of the present invention are as follows: the present invention squeezes the conductive sheet through the first liquid bag, so that the conductive sheet is adaptively wrapped according to its specific shape when connected to the test cable, reducing the possibility of air breakdown between the conductive sheet and the test cable, and in the process of squeezing the conductive sheet and the first liquid bag, the first liquid bag is squeezed and protrudes and wraps both sides of the conductive sheet, further isolating the conductive sheet from the external environment and improving the test safety; the spline rod cooperates with the first squeezing rod to drive the rotating ring to rotate, and the rotating ring and the two adjacent conductive blocks on the conductive frame are switched according to the test progress, so that the device does not need to repeatedly disassemble the complicated steps when switching the test cable, further ensuring the stability of the connection between the conductive sheet and the cable; the second fixed shell cooperates with the sliding rod to automatically complete the switching of the cable blocking and direct release after the cable test is completed, thereby improving the simplicity of the test process of the present device. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention; Figure 2 It is a schematic diagram of the three-dimensional structure of the internal structure of the isolation shell of the present invention; Figure 3 It is a schematic diagram of the three-dimensional structure of the mounting rod and the clamping shell of the present invention; Figure 4 It is a three-dimensional structural cross-sectional view of the clamping shell and the conductive sheet of the present invention; Figure 5 is a three-dimensional structural cross-sectional view of the first liquid capsule of the present invention in an expanded state; Figure 6 is a three-dimensional structural cross-sectional view of the positional relationship between the first liquid capsule and the separator of the present invention; Figure 7 It is a schematic diagram of the three-dimensional structure of the second electric push rod and the spline rod of the present invention; Figure 8 It is a schematic diagram of the three-dimensional structure of the sliding shell and the extrusion frame of the present invention; Fig. 9 It is a schematic diagram of the three-dimensional structure of the resistance block and the first conductive member of the present invention; Fig.10 It is an exploded view of the parts at the discharge rod of the present invention.

[0017] Markings in the accompanying drawings: 1: folding frame, 2: insulating shell, 3: first fixed frame, 301: first electric push rod, 4: fixed rod, 5: mounting rod, 6: clamping shell, 7: conductive sheet, 8: first fixed shell, 9: first liquid capsule, 10: partition, 11: pressure valve, 12: spring telescopic rod, 13: second fixed frame, 14: second liquid capsule, 15: sealing cover, 16: conductive frame, 17: rotating ring, 18: conductive block, 19: conductive rod, 20: discharge rod, 21: second electric push rod, 22: spline rod, 23: first extrusion rod, 24: fixed ring, 25: resistance block, 26: first conductive member, 261: second conductive member, 27: sliding shell, 28: extrusion frame, 29: second extrusion rod, 30: second fixed shell, 31: sliding rod. DETAILED DESCRIPTION

[0018] The present invention will be further described below in conjunction with specific embodiments. The illustrative embodiments and descriptions of the present invention are used to explain the present invention but are not intended to limit the present invention.

[0019] A withstand voltage test device for cables, such as Figure 1-Figure 6 As shown, it includes: a folding frame 1; an insulating shell 2, which is fixedly connected to the folding frame 1 and is provided with a through hole; a first fixed frame 3, which is fixedly connected to the insulating shell 2, and a fixed rod 4 is fixedly connected to the insulating shell 2, and the first fixed frame 3 and the fixed rod 4 are both provided with mounting rods 5 distributed in a circumferential array, and the first fixed frame 3 is fixedly connected with a first electric push rod 301 distributed in a circumferential array, and the telescopic end of the first electric push rod 301 is fixedly connected to the adjacent mounting rod 5, and the mounting rod 5 is fixedly connected to a clamping shell 6, and the clamping shell 6 is slidably connected with a conductive sheet 7, and tension springs are provided between the two sides of the conductive sheet 7 and the adjacent clamping shell 6, and the clamping shell 6 is fixedly connected with a first fixed shell 8 distributed in a mirror image, and the first fixed shell 8 is fixedly connected with a first liquid capsule 9, and the first liquid capsule 9 is used to squeeze and wrap the conductive sheet 7, and a control mechanism is provided in the first liquid capsule 9, and the control mechanism is used to control the flattening and expansion sequence of the first liquid capsule 9.

[0020] like Figure 5 and Figure 6 As shown, the control mechanism includes: a partition 10, fixedly connected in the first liquid bag 9; a pressure valve 11, fixedly connected to the side of the partition 10 away from the first fixed shell 8, and the length of the first liquid bag 9 on the axis of the fixed rod 4 is greater than the length of the conductive sheet 7 on the axis of the fixed rod 4, and a one-way valve is arranged on the side of the partition 10 close to the adjacent first fixed shell 8; a transmission assembly is arranged on the clamping shell 6, and is used to provide pressure to the first liquid bag 9 when the conductive sheet 7 clamps the cable.

[0021] In the above scheme, the conductive sheet 7 is a soft aluminum alloy sheet, which is used to fit the metal wire core exposed on the surface of the cable. The number of mounting rods 5 on the first fixing frame 3 and the fixing rod 4 is three, and the clamping shell 6 on the first fixing frame 3 and the adjacent clamping shell 6 on the fixing rod 4 are combined into a detection cylinder when fitting (that is, six clamping shells 6 are combined into three detection cylinders, which are used to clamp the three-phase cables A, B, and C respectively). After the first liquid capsule 9 expands, it squeezes the conductive sheet 7 toward the cable, so that the conductive sheet 7 is deformed and embedded in the gap between the metal wire cores in the cable, thereby increasing the conductive contact area and reducing the gap between the conductive sheet 7 and the cable. , thereby reducing the probability of electric sparks during the test (i.e., reducing the probability of air breakdown). There are three through holes on the isolation shell 2. The three-phase cables A, B, and C respectively pass through the three through holes on the isolation shell 2 and enter it. The isolation shell 2 is made of an insulating transparent material (the material of the isolation shell 2 in this solution is high-strength tempered glass). The first liquid capsule 9 and the separator 10 are both made of elastic materials. The separator 10 divides the first liquid capsule 9 into two chambers, and the expansion rate of the chamber on the side of the separator 10 close to the conductive sheet 7 is less than the expansion rate of the chamber on the other side. The flow direction of the one-way valve on the separator 10 is from the chamber on the side away from the conductive sheet 7 to the chamber on the other side.

[0022] like Figure 4 and Figure 5 As shown, the transmission assembly includes: a spring telescopic rod 12, which is fixed to the clamping shell 6, the fixed part of the spring telescopic rod 12 is fixed to the mounting rod 5, the mirror-distributed first fixed shells 8 are connected to the fixed part of the spring telescopic rod 12 through pipelines, and the fixed part of the spring telescopic rod 12 and the mirror-distributed first fixed shells 8 are filled with transmission medium; a second fixed frame 13, which is fixed to the telescopic end of the spring telescopic rod 12, the second fixed frame 13 is fixed with a second liquid capsule 14, the second liquid capsule 14 is used to squeeze the conductive sheet 7, the isolation shell 2 is threadedly connected with a sealing cover 15, the sealing cover 15 is slidably connected to the fixed rod 4, and the isolation shell 2 and the sealing cover 15 are both made of insulating materials.

[0023] In the above scheme, the fixed part of the spring telescopic rod 12 and the transmission medium in the mirror-distributed first fixed shell 8 are both insulating oil, which is used for hydraulic transmission while ensuring the safety of the test. The second liquid capsule 14 is also filled with insulating oil, and the second liquid capsule 14 is located in the middle of the conductive sheet 7. The sealing cover 15 is used to separate the test environment from the external environment during the test to improve the safety of the test. If necessary, an air drying device can be installed in the isolation shell 2 to reduce the air humidity in the test environment, thereby reducing the probability of air breakdown.

[0024] Specific working principle: When it is necessary to use this device to perform a withstand voltage test on the cable during the field cable laying process, the user first unfolds the folding frame 1 and places it at the cable test site, and sets the cable to the upper side of the folding frame 1. The user respectively passes the three-phase A, B, and C branches prepared in the cable into the isolation shell 2 through the three through holes on the isolation shell 2. Taking the A-phase cable as an example, the user moves the A-phase cable connector through the upper through hole to between the two conductive sheets 7 on the upper side of the isolation shell 2. Then the user controls the telescopic end of the first electric push rod 301 to extend and drive the clamp The shell 6 moves downward, and the clamping shell 6 drives the conductive sheet 7 to move gradually downward. During this process, the two conductive sheets 7 gradually squeeze the A-phase cable, and the two sides of the conductive sheet 7 gradually move outside the clamping shell 6. At the same time, the tension spring between the conductive sheet 7 and the clamping shell 6 is stretched, and the upper and lower conductive sheets 7 gradually wrap the A-phase cable until the two clamping shells 6 are in contact. At this time, the A-phase cable is connected, and then the user repeats the above steps to install the B and C phase cables. After the installation is completed, the user fixes the external cable to prevent external factors from interfering with the test process.

[0025] In the process that the two upper conductive sheets 7 gradually squeeze the A-phase cable, taking the lower conductive sheet 7 as an example, the conductive sheet 7 is squeezed downward by the A-phase cable, and when the conductive sheet 7 contacts the second liquid capsule 14, the conductive sheet 7 drives the second fixed frame 13 and the telescopic end of the spring telescopic rod 12 to move downward through the second liquid capsule 14, and the insulating oil in the fixed part of the spring telescopic rod 12 flows into the first fixed shell 8 through the pipeline between the fixed part of the spring telescopic rod 12 and the first fixed shell 8 after being squeezed, and the insulating oil flows into the first liquid capsule 9 through the first fixed shell 8. When the insulating oil is injected into the first liquid capsule 9, the upper part of the first liquid capsule 9 expands first, so that the first liquid capsule 9 gradually stretches and fits to the surface of the conductive sheet 7, until the first liquid capsule 9 is stretched completely, and the upper part of the first liquid capsule 9 Part of the insulating oil enters the lower chamber of the first liquid capsule 9 through the pressure valve 11, and the lower chamber of the first liquid capsule 9 gradually expands and squeezes the clamping shell 6 (that is, the first liquid capsule 9 gradually fills the gap between the conductive sheet 7 and the clamping shell 6), thereby squeezing the conductive sheet 7 and the A-phase cable. By virtue of the deformability of the structure of the first liquid capsule 9 and the flowability of the internal insulating oil, the conductive sheet 7 is squeezed to make it fit the A-phase cable more closely (the conductive sheet 7 adaptively wraps the shape of the A-phase cable), reducing the possibility of air breakdown between the conductive sheet 7 and the A-phase cable. During the squeezing process of the conductive sheet 7 and the first liquid capsule 9, the left and right sides of the first liquid capsule 9 are squeezed and raised and wrap the two sides of the conductive sheet 7, further isolating the conductive sheet 7 from the external environment, thereby improving the test safety.

[0026] After fixing the external cable, the user electrically connects the external DC high-voltage generator to the conductive sheet 7, and then performs a DC withstand voltage test on the three-phase cables A, B, and C one by one. At the same time, the user observes the cable data according to the indication of the high-voltage generator. After the test, the user controls the telescopic end of the first electric push rod 301 to retract and reset. The telescopic end of the first electric push rod 301 drives the clamping shell 6 and the parts thereon to reset. The conductive sheet 7 loses its clamping of the cable and resets under the action of the tension spring between it and the clamping shell 6. The spring telescopic rod 12 draws the insulating oil out of the first liquid capsule 9, and the first liquid capsule 9 gradually resets. The insulating oil in the chamber of the first liquid capsule 9 away from the adjacent conductive sheet 7 flows back through the one-way valve on the partition 10. The second liquid capsule 14 and the second fixing frame 13 are gradually reset under the drive of the telescopic part of the spring telescopic rod 12. Then the user draws the cable out of the isolation shell 2. At this time, the use of the device is completed.

[0027] like Figure 3 , Figure 7 and Figure 8 As shown, it also includes: a transposition mechanism, which is arranged on the fixed rod 4 and is used to switch the electrodes of the test cable. The transposition mechanism includes: a conductive frame 16, which is fixedly connected to the fixed rod 4, and the conductive frame 16 is fixedly connected to the first fixed frame 3; a rotating ring 17, which is rotatably connected to the fixed rod 4, and the conductive frame 16 and the rotating ring 17 are both provided with conductive blocks 18 distributed in a circumferential array, and the conductive blocks 18 on the conductive frame 16 and the conductive blocks 18 on the rotating ring 17 are used for contact conduction; a power component, which is arranged on the fixed rod 4 and is used to control the relative rotation angle of the conductive frame 16 and the rotating ring 17, and the rotating ring 17 is provided with a conductive rod 19, and the rotating ring 17 is provided with a discharge rod 20 distributed in a mirror image.

[0028] like Figure 3 and Figure 7 As shown, the power assembly includes: a second electric push rod 21, which is fixed in the fixed rod 4; a spline rod 22, which is spline-connected in the fixed rod 4, and the spline rod 22 is fixed to the telescopic end of the second electric push rod 21; a first extrusion rod 23, which is fixed to the rotating ring 17, and the fixed rod 4 is provided with an arc-shaped through groove for the first extrusion rod 23 to pass through, and the spline rod 22 is provided with an inclined groove, and the first extrusion rod 23 slides in the inclined groove on the spline rod 22.

[0029] In the above scheme, the conductive rod 19 is directly connected to the high voltage output end of the external DC high voltage generator, the two discharge rods 20 are grounded, the conductive rod 19 and the discharge rod 20 are respectively electrically connected to the adjacent conductive blocks 18 by wires (not shown in the figure), the conductive frame 16 is electrically connected to the conductive sheet 7, and the two adjacent conductive blocks 18 on the conductive frame 16 and the rotating ring 17 are conductive in a contact manner. In this embodiment, the number of conductive blocks 18 on the conductive frame 16 and the rotating ring 17 is three, and the inclined groove on the spline rod 22 cooperates with the first extrusion rod 23 to switch the two conductive sheets 7 electrically connected to the conductive rod 19, thereby completing the step-by-step DC withstand voltage detection of the three phases of the cables A, B, and C without changing the cable clamping state.

[0030] like Fig. 9 and Fig.10 As shown, it also includes: a discharge mechanism, which is arranged on the fixed rod 4 and is used to switch the discharge mode of the discharge rod 20. The discharge mechanism includes: a fixed ring 24, which is rotatably connected to the fixed rod 4, and the conductive rod 19 and the discharge rod 20 are both fixedly connected to the fixed ring 24; mirror-distributed resistor blocks 25, which are respectively slidably connected to adjacent discharge rods 20, the resistor block 25 is fixedly connected to a first conductive member 26, and the discharge rod 20 is fixedly connected to a second conductive member 261, the second conductive member 261 slides in the resistor block 25 and the first conductive member 26, and the resistor block 25 and the first conductive member 26 are jointly fixedly connected to a sliding shell 27; a switching component, which is arranged on the fixed rod 4 and is used to change the relative position of the resistor block 25 and the second conductive member 261.

[0031] like Figure 8-Figure 10 As shown, the switching assembly includes: an extrusion frame 28, which is fixed to the fixed rod 4, and the sliding shell 27 is fixed with a second extrusion rod 29, and the second extrusion rod 29 is used to drive the sliding shell 27 to move by extruding the extrusion frame 28; a delay assembly is arranged on the fixed ring 24, and is used to control the resistance block 25 to slowly reset.

[0032] like Figure 8-Figure 10 As shown, the delay component includes: a second fixed shell 30 distributed in a mirror image, which is fixed to the fixed ring 24, a sliding shell 27 is fixed with a sliding rod 31, the sliding rod 31 is slidably connected to the second fixed shell 30, a spring is arranged between the second fixed shell 30 and the sliding rod 31, a plurality of through holes are arranged on the sliding rod 31, and a one-way valve is arranged in each through hole on the sliding rod 31, and the second fixed shell 30 is filled with a transmission medium.

[0033] In the above scheme, the resistor block 25 and the first conductive member 26 are electrically connected to the second conductive member 261 by contact, and the greater the distance between the second conductive member 261 and the first conductive member 26, the greater the real-time resistance of the resistor block 25 when transmitting current. The extrusion frame 28 has four protrusions, wherein two adjacent protrusions form a group, and two adjacent protrusions are respectively located on both sides of the adjacent second extrusion rod 29, which are used to squeeze the second extrusion rod 29 to drive the sliding shell 27 to move, thereby changing the resistance value during discharge. The sliding rod 31 is composed of an L-shaped rod and a piston plate, and the through hole thereon is located on the piston plate part. The through holes of the piston plate part on the sliding rod 31 are large and two small. The one-way valve is located in the two larger through holes, and the flow direction of the one-way valve is from left to right.

[0034] Specific working principle: after the above-mentioned cable is installed, the user rotates the sealing cover 15 and removes it, then the user connects the high voltage output end of the external DC high voltage generator to the conductive rod 19, and connects the grounding wire of the external DC high voltage generator to the two discharge rods 20 respectively, then the user reinstalls the sealing cover 15 to the isolation shell 2, the user starts the external DC high voltage generator and performs a withstand voltage test on the A-phase cable. When the A-phase cable detection is completed, it is necessary to switch the detection cable and discharge the A-phase cable. Taking the subsequent withstand voltage test of the B-phase cable (located on the lower front side) as an example, the user controls the telescopic end of the second electric push rod 21 to retract, and the telescopic end of the second electric push rod 21 drives the spline rod 22 to move to the left. In this process, the inclined slide groove on the spline rod 22 squeezes the first squeezing The rod 23 drives the rotating ring 17 to rotate, and the rotating ring 17 drives the three conductive blocks 18 thereon to rotate clockwise (from left to right), so that the conductive block 18 electrically connected to the conductive rod 19 loses contact with the conductive block 18 on the upper side of the conductive frame 16 (that is, the conductive block 18 corresponding to the A-phase cable). The rotating ring 17 drives the fixed ring 24, the resistor block 25, the first conductive member 26 and the sliding shell 27 to rotate synchronously through the conductive rod 19 and the discharge rod 20. The sliding shell 27 drives the second extrusion rod 29 thereon to rotate. The second extrusion rod 29 and the protrusion on the extrusion frame 28 squeeze each other and drive the sliding shell 27 to move to the left. The sliding shell 27 drives the sliding rod 31 to move to the left synchronously. The hydraulic oil on the left part of the sliding rod 31 flows to the right side thereof through the through hole and the one-way valve thereon, and at the same time compresses the spring between the sliding rod 31 and the second fixed shell 30.

[0035] In the process of the sliding shell 27 moving to the left, the sliding shell 27 drives the resistor block 25 and the first conductive member 26 to move to the left synchronously, so that the second conductive member 261 gradually contacts the right end of the resistor block 25. At this time, the protrusion on the extrusion frame 28 loses contact with the adjacent second extrusion rod 29, the resistor block 25 is connected to the grounding line, and the discharge rod 20 on the lower rear side rotates to the upper side (i.e., the position corresponding to the A-phase cable, the conductive block 18 on the lower rear side of the rotating ring 17 rotates to contact the conductive block 18 on the upper side of the conductive frame 16). At this time, the residual current in the A-phase cable is blocked and discharged through the two conductive blocks 18, the discharge rod 20, the second conductive member 261 and the resistor block 25. At this time, the conductive rod 19 corresponds to the B-phase cable, and the spline rod 22 cooperates with the first extrusion rod 23 to drive the rotating ring 17 to rotate. According to the test process, the rotating ring 17 and the two adjacent conductive blocks 18 on the conductive frame 16 are switched, so that the device does not need to repeatedly disassemble the complicated steps when switching the test cable, further ensuring the stability of the connection between the conductive sheet 7 and the cable.

[0036] During the A-phase cable release process, the spring between the second fixed shell 30 and the sliding rod 31 drives the sliding rod 31 to gradually move to the right and reset. The hydraulic oil on the right side of the sliding rod 31 only flows to the left side through the two through holes on it. Due to the restriction of the one-way valve of the sliding rod 31, the sliding rod 31 slowly moves to the left and resets. During this process, the grounding wire resistance corresponding to the A-phase cable gradually decreases until the first conductive member 26 and the second conductive member 261 contact each other again, and the A-phase cable is released straight. At this time, the A-phase cable is released, and the second fixed shell 30 and the sliding rod 31 are connected to each other. After the cable test is completed, the switching between the blocked discharge and the direct discharge of the cable is automatically completed, which improves the simplicity of the test process of the device. When the B-phase cable test is completed, the user controls the telescopic end of the second electric push rod 21 to extend, and the spline rod 22 drives the rotating ring 17 to reverse through the first squeezing rod 23, so that the conductive block 18 electrically connected to the conductive rod 19 is rotated to contact the conductive block 18 corresponding to the C-phase cable (the conductive block 18 at the rear of the lower side), and then the B-phase cable performs the above-mentioned discharge operation. After the discharge contact, the above-mentioned test steps are repeated to test the C-phase cable.

[0037] The above description is only an example of the present invention and is not intended to limit the present invention. Any equivalent substitutions made within the principles of the present invention should be included in the protection scope of the present invention. The contents not elaborated in detail in the present invention belong to the existing technologies known to those skilled in the art.

Claims

1. A voltage withstand test device for a cable, characterized in that: include: Folding stand (1); An isolation shell (2) is fixedly connected to the folding frame (1), and a through hole is provided on the isolation shell (2); A first fixing frame (3) is fixedly connected to the isolation shell (2), a fixing rod (4) is fixedly connected to the isolation shell (2), the first fixing frame (3) and the fixing rod (4) are both provided with mounting rods (5) distributed in a circumferential array, the first fixing frame (3) is fixedly connected with a first electric push rod (301) distributed in a circumferential array, the telescopic end of the first electric push rod (301) is fixedly connected to the adjacent mounting rod (5), the mounting rod (5) is fixedly connected with a clamping shell (6), the clamping shell (6) is slidably connected with a conductive sheet (7), tension springs are provided between the two sides of the conductive sheet (7) and the adjacent clamping shell (6), the clamping shell (6) is fixedly connected with a first fixing shell (8) distributed in a mirror image, the first fixing shell (8) is fixedly connected with a first liquid capsule (9), the first liquid capsule (9) is used to squeeze and wrap the conductive sheet (7), a control mechanism is provided in the first liquid capsule (9), the control mechanism is used to control the flattening and expansion sequence of the first liquid capsule (9).

2. A voltage withstand test device for cables according to claim 1, characterized in that: The control mechanism comprises: A separator (10) fixedly connected to the first liquid capsule (9); a pressure valve (11) fixedly connected to a side of the partition (10) away from the first fixed shell (8), wherein the length of the first liquid capsule (9) on the axis of the fixed rod (4) is greater than the length of the conductive sheet (7) on the axis of the fixed rod (4), and a one-way valve is provided on a side of the partition (10) adjacent to the first fixed shell (8); A transmission assembly is arranged on the clamping shell (6) and is used to provide pressure to the first liquid bag (9) when the conductive sheet (7) clamps the cable.

3. A withstand voltage test device for cables according to claim 2, characterized in that: The transmission assembly comprises: A spring telescopic rod (12) is fixedly connected to the clamping shell (6), a fixed portion of the spring telescopic rod (12) is fixedly connected to the mounting rod (5), and the first fixed shells (8) distributed in a mirror image are both connected to the fixed portion of the spring telescopic rod (12) through a pipeline; The second fixing frame (13) is fixedly connected to the telescopic end of the spring telescopic rod (12), and the second fixing frame (13) is fixedly connected with a second liquid bag (14), and the second liquid bag (14) is used to compress the conductive sheet (7).

4. A voltage withstand test device for cables according to claim 3, characterized in that: The isolation shell (2) is threadedly connected to a sealing cover (15), the sealing cover (15) is slidably connected to the fixing rod (4), and the isolation shell (2) and the sealing cover (15) are both made of insulating material.

5. A voltage withstand test device for cables according to claim 4, characterized in that: Also includes: A switching mechanism is arranged on the fixing rod (4) and is used to switch the electrodes of the test cable. The switching mechanism comprises: A conductive frame (16) is fixedly connected to the fixing rod (4), and the conductive frame (16) is fixedly connected to the first fixing frame (3); a rotating ring (17) rotatably connected to the fixed rod (4); the conductive frame (16) and the rotating ring (17) are both provided with conductive blocks (18) distributed in a circumferential array; the conductive blocks (18) on the conductive frame (16) and the conductive blocks (18) on the rotating ring (17) are used for contact conduction; A power assembly is arranged on the fixing rod (4) and is used to control the relative rotation angle between the conductive frame (16) and the rotating ring (17).

6. A voltage withstand test device for cables according to claim 5, characterized in that: The rotating ring (17) is provided with a conductive rod (19), and the rotating ring (17) is provided with a discharge rod (20) distributed in a mirror image.

7. A voltage withstand test device for cables according to claim 6, characterized in that: The power assembly comprises: A second electric push rod (21) is fixedly connected inside the fixing rod (4); A spline rod (22) spline-connected inside the fixing rod (4), the spline rod (22) being fixedly connected to the telescopic end of the second electric push rod (21); The first extrusion rod (23) is fixedly connected to the rotating ring (17); the fixed rod (4) is provided with an arc-shaped through groove for the first extrusion rod (23) to pass through; the spline rod (22) is provided with an inclined groove; the first extrusion rod (23) slides in the inclined groove on the spline rod (22).

8. A withstand voltage test device for cables according to claim 7, characterized in that: Also includes: A discharge mechanism is arranged on the fixed rod (4) and is used to switch the discharge mode of the discharge rod (20), the discharge mechanism comprising: A fixing ring (24) is rotatably connected to the fixing rod (4), and the conductive rod (19) and the discharge rod (20) are both fixedly connected to the fixing ring (24); The resistor blocks (25) are respectively connected to adjacent discharge rods (20) in a sliding manner. The resistor block (25) is fixedly connected to a first conductive member (26). The discharge rod (20) is fixedly connected to a second conductive member (261). The second conductive member (261) slides inside the resistor block (25) and the first conductive member (26). The resistor block (25) and the first conductive member (26) are fixedly connected to a sliding shell (27). A switching component is arranged on the fixing rod (4) and is used to change the relative position of the resistance block (25) and the second conductive member (261).

9. A voltage withstand test device for cables according to claim 8, characterized in that: The switching component comprises: An extrusion frame (28) is fixedly connected to the fixed rod (4); the sliding shell (27) is fixedly connected to a second extrusion rod (29); the second extrusion rod (29) is used to drive the sliding shell (27) to move by extruding the extrusion frame (28); A delay component is arranged on the fixing ring (24) and is used to control the resistance block (25) to slowly reset.

10. A voltage withstand test device for a cable according to claim 9, characterized in that: The delay component comprises: The second fixed shells (30) are arranged in a mirror image and are fixed to the fixed ring (24). The sliding shell (27) is fixed to a sliding rod (31). The sliding rod (31) is slidably connected to the second fixed shell (30). A spring is arranged between the second fixed shell (30) and the sliding rod (31). The sliding rod (31) is provided with a plurality of through holes, and a one-way valve is arranged in each through hole on the sliding rod (31).

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