Fire-resistant medium voltage cable and method for detecting properties thereof

Abstract

The application discloses a fire-resistant medium-voltage cable and a performance detection method thereof, and relates to the technical field of cables.The fire-resistant medium-voltage cable comprises a cable, and the cable comprises an impact-resistant buffer layer, the inner wall of the impact-resistant buffer layer is sequentially provided with an expanded mica tape, a corrugated stainless steel tape armor and a ceramic fiber woven mesh, the inner wall of the ceramic fiber woven mesh is provided with a filling layer, the filling layer is internally provided with a double-gradient ceramic insulation layer, the inner wall of the double-gradient ceramic insulation layer is provided with a double-layer heterogeneous semi-conductive water-resistant tape, and the inner wall of the double-layer heterogeneous semi-conductive water-resistant tape is provided with a copper conductor.The protection mechanism is arranged and completely wrapped by the sponge pad, so that the cable can be pre-clamped, the cable at this time exists between the two opening and closing plates and the sponge pad, and will not fall off, thereby facilitating the adjustment of the specific position of the cable, and the two ends of the cable are clamped into the clamping head more conveniently and quickly, and the problem that the cable is difficult to be manually clamped into the clamping head due to the heavy weight of the cable will not occur.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of cables, in particular to a fire-resistant medium-voltage cable and a performance detection method thereof. BACKGROUND

[0002] Fire-resistant cables are widely used in important departments and public places such as high-rise buildings, subways, power plants, nuclear power plants, etc. At the same time, many infrastructure projects begin to prefer fire-resistant cables in order to keep the power supply system stable and normal operation after a fire, which helps to carry out rescue work and minimize personnel casualties and financial losses.

[0003] The patent application with the publication number CN110136892A describes a method for manufacturing a ceramicized polyolefin fire-resistant medium-voltage cable. The manufacturing method of the cable is as follows: wire drawing → conductor stranding → three-layer co-extrusion chemical cross-linking → buffer layer → metal shielding → cabling → oxygen barrier layer → first wrapping layer → fire-resistant layer → second wrapping layer → armored layer → third wrapping layer → extrusion of outer sheath → performance detection. The cable fully considers the relationship between the electrical performance and fire resistance of medium and high voltage cables, solves the balance point between the two, and uses extruded ceramicized polyolefin as the fire-resistant layer. When the cable burns, it can quickly form a hard, dense ceramic heat and oxygen barrier layer. The processing technology is simple, can meet the power frequency withstand voltage test after the fire resistance test, and the insulation layer can be intact at high temperature to ensure the normal operation and operation of the product.

[0004] During the tensile detection of the cable, once it breaks, it may pose a risk to the safety of personnel. The broken cable may produce flying debris or sharp edges, posing a risk of physical injury such as cuts and scratches to the detection personnel or other persons present, as well as a risk of equipment damage. The broken cable may damage the equipment or instruments connected to it, causing equipment failure or damage. SUMMARY

[0005] To overcome the shortcomings of the prior art, the present application provides a fire-resistant medium-voltage cable and a performance detection method thereof, which achieves the purpose of solving the above problems.

[0006] To achieve the above purpose, the present application is implemented by the following technical solution: a fire-resistant medium-voltage cable, comprising a cable, the cable comprising an impact-resistant buffer layer, the inner wall of the impact-resistant buffer layer sequentially provided with an expanded mica tape, a corrugated stainless steel tape armor, and a ceramic fiber woven mesh, the inner wall of the ceramic fiber woven mesh provided with a filler layer, the filler layer internally provided with a double-gradient ceramicized insulation layer, the inner wall of the double-gradient ceramicized insulation layer provided with a double-layer heterogeneous semi-conductive water-resistant tape, and the inner wall of the double-layer heterogeneous semi-conductive water-resistant tape provided with a copper conductor.

[0007] Double gradient ceramic insulation layer: inner layer is ceramic silicone rubber doped with silicon carbide whiskers, outer layer is boron modified ceramic organic silicon, forming a gradient ceramic structure at high temperature;

[0008] Double-layer heterogeneous semiconductive hose: inner layer is super-smooth semiconductive polyester tape, outer layer is high-adhesion semiconductive hose containing nano-graphene.

[0009] A method for detecting the performance of a fire-resistant medium-voltage cable, comprising the following steps:

[0010] S1: The two ends of the cable to be tested for tensile strength are simply cleaned and wiped, and then taken to the tensile testing machine;

[0011] S2: The two ends of the cable are inserted into the upper and lower clamping heads in the tensile testing machine, and then the clamping heads are controlled to clamp and fasten the two ends of the cable;

[0012] S3: After clamping and fastening the cable, the lifting plate inside the tensile testing machine is started to slide downward, and the lower clamping head is pulled downward to complete the tensile test of the cable.

[0013] Preferably, the connecting block is fixedly connected inside the tensile testing machine, one end of the connecting block is fixedly connected with the outer wall of the clamping head, the number of clamping heads is two, and a protection mechanism is arranged between the two clamping heads;

[0014] The protection mechanism comprises:

[0015] Roller, the roller is a long columnar structure, the outer wall of the roller is slidably connected with a sliding sleeve through a dovetail groove;

[0016] The opening and closing plate is an arc plate structure, the inner wall of the opening and closing plate is fixedly connected with a sponge pad, one side of the opening and closing plate is fixedly connected with the outer wall of the sliding sleeve, and the opening and closing plate is used for wrapping and protecting the cable.

[0017] Preferably, the number of opening and closing plates is two, one side of one of the opening and closing plates is fixedly connected with a first rotating shaft, one side of the other opening and closing plate is fixedly connected with a second rotating shaft, the inner wall of the second rotating shaft is slidably connected with the outer wall of the first rotating shaft, and the outer walls of the two opening and closing plates are fixedly connected with elastic plates.

[0018] Preferably, the first rotating shaft is rotatably connected with a connecting shaft at the top, the connecting shaft is fixedly connected with a connecting plate at the top, the connecting plate is fixedly connected with a fixing sleeve through an elastic sleeve at the top, the fixing sleeve is fixedly connected with the outer wall of the clamping head through a fixed long plate at the top, and the first rotating shaft and the connecting plate are fixedly connected with a spring.

[0019] Preferably, the outer wall of the connecting plate is provided with an observation mechanism, the observation mechanism comprises a connecting pipe, one end of the connecting pipe is fixedly connected with the outer wall of the connecting plate, the other end of the connecting pipe is fixedly connected with an opening and closing plate, a sliding groove is formed in the opening and closing plate, an arc-shaped telescopic sleeve is fixedly connected with the inner wall of the sliding groove, the connecting pipe is in communication with the inside of the arc-shaped telescopic sleeve through the opening and closing plate, and the inside of the telescopic sleeve is in communication with the inside of the connecting pipe through the connecting plate.

[0020] Preferably, one end of the arc-shaped telescopic sleeve is fixedly connected with a sliding block, the outer wall of the sliding block is slidably connected with the inner wall of the sliding groove, one side of the sliding block is fixedly connected with a transparent portrait elastic film, the other side of the transparent portrait elastic film is fixedly connected with one side of a sliding sleeve, and the transparent portrait elastic film is arranged in the sliding groove.

[0021] Preferably, a scale groove is formed in the outer wall of the opening and closing plate, the scale groove is a vertical groove, a second groove is formed in the inner wall of the sponge pad, and a first groove is formed in the inner wall of the opening and closing plate.

[0022] The application provides a fire-resistant medium-voltage cable and a performance detection method thereof, and has the following beneficial effects:

[0023] 1. In the double-gradient ceramic insulation layer of the application, the layered structure prevents crack propagation; the zirconite material also provides low-temperature ceramic formation capability (starting at 500 DEG C), and the outer layer material: boron nitride sheet layer + magnesium aluminum silicate, can reflect thermal radiation; the super-smooth structure of the inner layer of the double-layer hetero-semi-conductive water-blocking tape: polyester non-woven fabric plasma treatment + carbon black / polyurethane composite coating can make the surface roughness Ra less than or equal to 0.1 microns, thereby reducing the risk of conductor surface micro-discharge, reducing conductor damage in the inner layer (super-smooth), and realizing dynamic water-blocking in the outer layer (high adhesion);

[0024] 2. The application realizes chemical gradient combination without transition layer through the difference in melt rheological properties between the inner layer (low temperature and high viscosity) and the outer layer (high temperature and low viscosity) by using a double-stage extruder with gradient temperature control and a gradually tapered flow channel, and ensures the effect of no air bubbles between the water-blocking tape wrapping layers by using servo motor constant tension control and preheating roller auxiliary wrapping;

[0025] 3. The application realizes the expansion and opening of the two rollers by setting the protection mechanism, until the cable is completely inserted into the two opening and closing plates and completely wrapped by the sponge pad, so that the cable can be pre-clamped, and the cable is between the two opening and closing plates and the sponge pad at this time, and will not fall off, thereby facilitating the adjustment of the specific position of the cable, and the clamping of the two ends of the cable into the clamping head is more convenient and fast, and the problem of difficult manual clamping into the clamping head due to the heavy cable does not occur.

[0026] 4. The present invention provides a protective mechanism and also uses rollers and sponge pads to limit the vertical position of the cable, thereby ensuring that the cable is in a vertical state when clamped in the clamping head. This prevents the cable from being clamped crookedly when both ends are clamped in the clamping head, which would cause torsional crookedness during subsequent tensile testing and affect the test data.

[0027] 5. The present invention sets a protective mechanism. When the cable is subsequently pulled for tensile testing, the noise generated by the internal pulling can be reduced by wrapping the sponge pad. The wrapped sponge pad and the opening and closing plate can limit the cable to avoid the cable breaking during the tensile test. The internal conductor rebounds with its toughness and hits the surrounding personnel and electrical equipment, causing a huge safety hazard. The stable operation can be ensured and accidents can be avoided.

[0028] 6. The present invention provides an observation mechanism. When the cable is pushed into the roller, the roller rotates in the sliding sleeve to reduce the friction between the cable and the roller, converting the sliding friction into rolling friction, thereby ensuring that the outer wall of the cable is not damaged when it is clamped by the roller and the sponge pad.

[0029] 7. The present invention sets up an observation mechanism, and as the tension test proceeds, the sliding block and the arc-shaped telescopic sleeve will reduce the coverage of the first groove inside the opening and closing plate and the exposed area of ​​the second groove inside the sponge pad, so that the surrounding staff can clearly judge the progress of their work by the range of reduced coverage, and make a quick and easy progress judgment through the positional relationship between the scale groove and the sliding block, so as to facilitate understanding of the current work progress and take targeted measures for subsequent work. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 Schematic diagram of the structure of the cable of the present invention;

[0031] Figure 2 It is a structural schematic diagram of the tensile testing machine of the present invention;

[0032] Figure 3 It is a structural schematic diagram of the clamping head of the present invention;

[0033] Figure 4 Schematic diagram of the structure of the protection mechanism of the present invention Figure 1 ;

[0034] Figure 5 Schematic diagram of the structure of the protection mechanism of the present invention Figure 2 ;

[0035] Figure 6 For the present invention Figure 4 A magnified view of point A;

[0036] Figure 7 Structure diagram of the protection mechanism of the present application Figure 3 ;

[0037] Figure 8 Structure movement diagram of the protection mechanism of the present application

[0038] Figure 9 Structure movement diagram of the observation mechanism of the present application

[0039] Figure 10 Structure diagram of the observation mechanism of the present application

[0040] Figure 11 Enlarged view of B of the present application Figure 9

[0041] Figure 12 Enlarged view of C of the present application Figure 9

[0042] In the figure: 1 tension detection machine, 2 connecting block, 3 protection mechanism, 301 roller, 302 sliding sleeve, 303 opening and closing plate, 304 first rotating shaft, 305 second rotating shaft, 306 sponge pad, 307 elastic plate, 308 spring, 309 connecting shaft, 310 connecting plate, 311 telescopic sleeve, 312 fixed sleeve, 313 fixed long plate, 4 observation mechanism, 401 connecting pipe, 402 arc-shaped telescopic sleeve, 403 sliding block, 404 sliding groove, 406 scale groove, 407 first recess, 408 second recess, 5 clamping head, 6 lifting plate, 7 cable, 8 expanded mica tape, 9 corrugated stainless steel armor, 10 ceramic fiber woven net, 11 filling layer, 12 double-gradient ceramic insulation layer; 13 double-layer heterogeneous semi-conductive water-resistant tape; 14 copper conductor, 15 impact-resistant buffer layer. DETAILED DESCRIPTION

[0043] Example one: please refer to Figures 1-3 The present application provides a technical solution: a fire-resistant medium-voltage cable, comprising a cable 7, the cable 7 comprising an impact-resistant buffer layer 15, the inner wall of the impact-resistant buffer layer 15 being sequentially provided with an expanded mica tape 8, a corrugated stainless steel armor 9, and a ceramic fiber woven net 10, the inner wall of the ceramic fiber woven net 10 being provided with a filling layer 11, the inside of the filling layer 11 being provided with a double-gradient ceramic insulation layer 12, the inner wall of the double-gradient ceramic insulation layer 12 being provided with a double-layer heterogeneous semi-conductive water-resistant tape 13, and the inner wall of the double-layer heterogeneous semi-conductive water-resistant tape 13 being provided with a copper conductor 14.

[0044] The double-gradient ceramic insulation layer 12: the inner layer is ceramicized silicone rubber doped with silicon carbide whiskers, and the outer layer is boron-modified ceramicized organic silicon, which forms a gradient ceramic structure at high temperature.

[0045] The ceramicized silicone rubber containing silicon carbide whiskers comprises the following materials:​​

[0046] Base material: methyl vinyl silicone rubber, functional filler: silicon carbide whisker, porcelainizing aid: zirconite powder, crosslinking agent: dicumyl peroxide;

[0047] Boron-modified ceramicized silicone comprises the following materials:

[0048] Matrix: phenyl silicone rubber, modifier: hexagonal boron nitride sheet (thickness <100 nm), porcelain phase: aluminum magnesium silicate nanoparticles, flame retardant synergist: magnesium hydroxide-coated red phosphorus microcapsule;

[0049] The gradient structure is realized by the following co-extrusion process parameters:

[0050] A double-stage extruder is used, and the inner layer extrusion temperature is 90±5℃ in the first stage, 120±5℃ in the second stage, and 150±5℃ at the die head. The outer layer extrusion temperature is 110±5℃ in the first stage, 140±5℃ in the second stage, and 170±5℃ at the die head.

[0051] The die design sets an annular tapered runner (cone angle 15°±2°) to form an interpenetrating structure by the difference in melt flow rate;

[0052] Double-layer heterogeneous semiconductive hose 13: inner layer is super-smooth semiconductive polyester tape, outer layer is high-adhesion semiconductive hose containing nano-graphene;

[0053] Surface treatment process of super-smooth semiconductive polyester tape:

[0054] Substrate: polyester non-woven fabric, plasma treated (argon atmosphere, power 300W, treatment time 120s), conductive coating: carbon black / polyurethane composite slurry (solid content 45%), coating amount 12±2g / m², polishing process: hot calendering light (temperature 180℃, pressure 8MPa, speed 5m / min) to make the surface roughness Ra≤0.1μm;

[0055] Functional layer structure of high-adhesion semiconductive hose containing nano-graphene:

[0056] Base tape: polyimide film with a thickness of 0.15mm, adhesive layer: epoxy resin adhesive (epoxy value 0.45-0.55) with 5-8wt% amino-functionalized graphene oxide added, water-blocking material: water-absorbing and swelling rubber particles;

[0057] Winding process control:

[0058] Overlap angle control: constant tension winding machine driven by a servo motor, tension setting: inner layer tape 1.5±0.2N, outer layer tape 2.0±0.3N, preheating temperature: tape passes through a preheating roller at 80℃ before winding.

[0059] In the double gradient ceramic insulation layer of the crosslinked polyethylene insulated power cable, the layered structure prevents crack propagation; the zirconite material also provides low-temperature porcelainization capability (500°C and above), and the outer layer material: boron nitride sheet + magnesium aluminum silicate, can reflect thermal radiation; the super smooth structure of the inner layer of the double-layer heterogeneous semiconductive water-blocking tape: polyester non-woven fabric plasma treatment + carbon black / polyurethane composite coating can make the surface roughness Ra≤0.1μm, which can reduce the risk of micro-discharge on the surface of the conductor, the inner layer (super smooth) reduces the damage to the conductor, and the outer layer (high adhesion) realizes the dynamic water-blocking effect.

[0060] At the same time, through the flow channel of the double-stage extruder gradient temperature control + die taper, the difference in melt rheological properties between the inner layer (low temperature and high viscosity) and the outer layer (high temperature and low viscosity) can realize the chemical gradient combination without a transition layer, and the servo motor constant tension control + preheating roller auxiliary wrapping ensures that there is no air bubble between the wrapping layers of the water-blocking tape.

[0061] Example two: please refer to Figures 1-8 On the basis of example one, the application provides a technical solution:

[0062] A fire-resistant medium-voltage cable performance detection method, comprising the following steps:

[0063] S1, the two ends of the cable 7 to be subjected to tensile testing are simply cleaned and wiped, and then taken to the tensile testing machine 1;

[0064] S2, the two ends of the cable 7 are connected to the upper and lower clamping heads 5 in the tensile testing machine 1, and then the clamping heads 5 are controlled to clamp and fasten the two ends of the cable 7;

[0065] S3, after the cable 7 is clamped and fastened, the tensile testing machine 1 is started to control the lifting plate 6 inside to slide downward, and the lower clamping head 5 is pulled to move downward, so that the tensile test of the cable 7 is completed.

[0066] The connecting block 2 is fixedly connected inside the tensile testing machine 1, one end of the connecting block 2 is fixedly connected with the outer wall of the clamping head 5, the number of clamping heads 5 is two, and a protection mechanism 3 is arranged between the two clamping heads 5;

[0067] The protection mechanism 3 comprises:

[0068] The roller 301 is a long columnar structure, and the outer wall of the roller 301 is slidably connected with the sliding sleeve 302 through a dovetail groove;

[0069] The opening and closing plate 303 is an arc plate structure, the inner wall of the opening and closing plate 303 is fixedly connected with the sponge pad 306, one side of the opening and closing plate 303 is fixedly connected with the outer wall of the sliding sleeve 302, and the opening and closing plate 303 is used for wrapping and protecting the cable 7.

[0070] The two opening and closing plates 303 are fixedly connected with the first rotating shaft 304 and the second rotating shaft 305 respectively, and the inner wall of the second rotating shaft 305 is slidably connected with the outer wall of the first rotating shaft 304. The outer wall of the two opening and closing plates 303 is fixedly connected with the elastic plate 307.

[0071] The top of the first rotating shaft 304 is rotatably connected with the connecting shaft 309, the top of the connecting shaft 309 is fixedly connected with the connecting plate 310, the top of the connecting plate 310 is fixedly connected with the fixed sleeve 312 through the telescopic sleeve 311, the top of the fixed sleeve 312 is fixedly connected with the outer wall of the clamping head 5 through the fixed long plate 313, and the spring 308 is fixedly connected between the first rotating shaft 304 and the connecting plate 310.

[0072] In use, the two ends of the cable 7 to be tested are inserted into the upper and lower clamping heads 5, and then the two ends of the cable 7 are clamped by controlling the clamping heads 5, and then the lifting plate 6 is started to begin to descend to test the tension of the cable 7.

[0073] Before the two ends of the cable 7 are clamped into the clamping head 5, the cable 7 is first pushed into the two rollers 301, and the two rollers 301 are cylindrical, so that the two rollers 301 can be easily pushed apart. The roller 301 drives the two opening and closing plates 303 to rotate on the first rotating shaft 304 and the second rotating shaft 305 respectively through the sliding sleeve 302, and the elastic plate 307 is deformed to expand the two rollers 301, until the cable 7 is completely inserted into the two opening and closing plates 303 and completely wrapped by the sponge pad 306, so that the cable 7 can be pre-clamped. At this time, the cable 7 is between the two opening and closing plates 303 and the sponge pad 306, and will not fall off, and then the specific position of the cable 7 can be adjusted, and the two ends of the cable 7 are clamped into the clamping head 5 more conveniently and quickly, and the problem of difficult manual clamping of the cable 7 into the clamping head 5 due to the heavy weight of the cable 7 will not occur.

[0074] The vertical position of the cable 7 is also limited by the roller 301 and the sponge pad 306, which ensures that the cable 7 is in a vertical state when clamped into the clamping head 5, so that when the two ends of the cable 7 are clamped into the clamping head 5, the problem of twisting and skewing during the subsequent tension test will not occur, which will affect the detection data.

[0075] And in the subsequent tension pull to pull the cable 7 to detect the tension, the use of sponge pad 306 wrapped can reduce the noise generated inside the pull, and wrapped sponge pad 306 and open-close plate 303 can be limited to cable 7, avoid once the tension detection cable 7 fracture, resulting in the internal conductor with its resilience rebound and hit to the surrounding staff and electrical equipment, causing great security problems occur, in turn, can ensure the stability of the work, avoid accidents;

[0076] Two open-close plate 303 open-close will extrude the rear elastic plate 307 to make it change, when the cable 7 embedded in the open-close plate 303 inside, open-close plate 303 will be pushed back to the reset by the elastic plate 307 rebound force;

[0077] When the cable 7 push into the roller 301, the roller 301 will rotate in the sliding sleeve 302, to reduce the friction between the cable 7 push in, and the roller 301, the sliding friction into rolling friction, so as to ensure that the outer wall of the cable 7 is not damaged when being clamped by the roller 301 and the sponge pad 306;

[0078] Spring 308 is used for the two open-close plate 303 and the first shaft 304 center reset, because the fixed long plate 313 and the fixed sleeve 312, telescopic sleeve 311, connecting plate 310 are fixed, can not rotate, so that the lower first shaft 304 can be kept in the middle of the direction of the torsion of the connecting shaft 309, so as to avoid the deviation;

[0079] Example three: please refer to Figures 1-12 On the basis of example one and example two, the application provides a technical scheme: the connecting plate 310 outer wall is provided with observation mechanism 4, the observation mechanism 4 includes connecting pipe 401, one end of connecting pipe 401 and connecting plate 310 outer wall fixed connection, the other end of connecting pipe 401 and open-close plate 303 fixed connection, open-close plate 303 inside is provided with sliding groove 404, the inner wall of sliding groove 404 is fixedly connected with arc telescopic sleeve 402, connecting pipe 401 communicates with arc telescopic sleeve 402 inside through open-close plate 303, telescopic sleeve 311 communicates with connecting pipe 401 inside through connecting plate 310 inside.

[0080] Arc telescopic sleeve 402 one end is fixedly connected with sliding block 403, the outer wall of sliding block 403 and the inner wall of sliding groove 404 are slidably connected.

[0081] The outer wall of open-close plate 303 is provided with scale groove 406, the scale groove 406 is vertical groove, the inner wall of sponge pad 306 is provided with second groove 408, the inner wall of open-close plate 303 is provided with first groove 407;

[0082] When the lower clamping head 5 is pulled down by the lifting plate 6, the cable 7 is pulled by the increase of the distance between the two clamping heads 5, and when the lower clamping head 5 is pulled, the telescopic sleeve 311 between the fixed sleeve 312 and the connecting plate 310 is pulled to be longer, and after the telescopic sleeve 311 is longer, the space in the telescopic sleeve 311 is increased, and then the air in the arc-shaped telescopic sleeve 402 is sucked into the telescopic sleeve 311 through the connecting pipe 401, so that the sliding block 403 in the sliding groove 404 slides to the position of the first rotating shaft 304, and the transparent rubber elastic film is fixedly connected to one side of the sliding block 403 and the other side of the sliding sleeve 302.

[0083] With the increase of the pulling distance, the sliding distance of the sliding block 403 is also increased, the arc-shaped telescopic sleeve 402 is shortened to reduce the surface area, and the coverage area of the exposed first groove 407 and second groove 408 is reduced, so that the surrounding workers can clearly judge the work progress by the reduced coverage area, and the opening height of the second groove 408 and the first groove 407 is very small, and the opening size is smaller than the broken pieces of the cable 7, so that the broken pieces of the cable 7 are also wrapped by the opening and closing plate 303, and cannot fly out through the openings 408 and 407, and the transparent rubber elastic film connected between the sliding block 403 and the sliding sleeve 302 can further prevent the particles and debris generated when the internal cable 7 is broken, so as to protect the surrounding workers from being hurt, and also can be transparent and convenient for workers to clean and observe.

[0084] At this time, the position relationship between the scale groove 406 and the sliding block 403 is used to quickly and simply judge the progress, so as to understand the current work progress and take targeted measures for subsequent work.

[0085] The above is only a preferred specific embodiment of the present application, but the protection scope of the present application is not limited thereto, and any skilled person in the art can make equivalent replacement or change according to the technical solution and the inventive concept of the present application within the technical range disclosed by the present application, which should be covered within the protection scope of the present application.

Claims

1. A method for testing the performance of a fire-resistant medium-voltage cable, characterized by: The following steps are involved: S1: briefly clean and wipe both ends and the outer surface of the cable (7) to be tested for tension, and then take it to the tension testing machine (1); S2: Connect the two ends of the cable (7) to the upper and lower clamping heads (5) in the tension testing machine (1), and then clamp and tighten the two ends of the cable (7) by controlling the clamping heads (5); S3: After the cable (7) is clamped and tightened, the tensile testing machine (1) is started to control the internal lifting plate (6) to slide downward, and the clamping head (5) below is pulled downward to complete the tensile test of the cable (7); The tensile testing machine (1) is internally fixedly connected to a connecting block (2), one end of the connecting block (2) is fixedly connected to the outer wall of a clamping head (5), the number of the clamping heads (5) is two, and a protective mechanism (3) is provided between the two clamping heads (5); The protection mechanism (3) comprises: A roller (301), the roller (301) is a long columnar structure, and the outer wall of the roller (301) is slidably connected to a sliding sleeve (302) via a dovetail groove; An opening and closing plate (303), wherein the opening and closing plate (303) is an arc-shaped plate-like structure, wherein a sponge pad (306) is fixedly connected to the inner wall of the opening and closing plate (303), and one side of the opening and closing plate (303) is fixedly connected to the outer wall of the sliding sleeve (302), and the opening and closing plate (303) is used to wrap and protect the cable (7); There are two opening and closing plates (303), one side of one opening and closing plate (303) is fixedly connected to a first rotating shaft (304), and one side of the other opening and closing plate (303) is fixedly connected to a second rotating shaft (305), an inner wall of the second rotating shaft (305) is slidably connected to an outer wall of the first rotating shaft (304), and an elastic plate (307) is fixedly connected to the outer walls of the two opening and closing plates (303); The top of the first rotating shaft (304) is rotatably connected to a connecting shaft (309), the top of the connecting shaft (309) is fixedly connected to a connecting plate (310), the top of the connecting plate (310) is fixedly connected to a fixing sleeve (312) via a telescopic sleeve (311), the top of the fixing sleeve (312) is fixedly connected to the outer wall of the clamping head (5) via a fixed long plate (313), and a spring (308) is fixedly connected between the first rotating shaft (304) and the connecting plate (310); The outer wall of the connecting plate (310) is provided with an observation mechanism (4), and the observation mechanism (4) includes a connecting tube (401), one end of the connecting tube (401) is fixedly connected to the outer wall of the connecting plate (310), and the other end of the connecting tube (401) is fixedly connected to the opening and closing plate (303). A chute (404) is provided inside the opening and closing plate (303), and an arc-shaped telescopic sleeve (402) is fixedly connected to the inner wall of the chute (404). The connecting tube (401) is communicated with the interior of the arc-shaped telescopic sleeve (402) through the opening and closing plate (303), and the interior of the telescopic sleeve (311) is communicated with the interior of the connecting tube (401) through the connecting plate (310); One end of the arc-shaped telescopic sleeve (402) is fixedly connected to a sliding block (403), an outer wall of the sliding block (403) is slidably connected to an inner wall of the sliding groove (404), one side of the sliding block (403) is fixedly connected to a transparent rubber elastic membrane, the other side of the transparent rubber elastic membrane is fixedly connected to one side of the sliding sleeve (302), and the transparent rubber elastic membrane is placed inside the sliding groove (404).

2. A fire-resistant medium voltage cable performance testing method according to claim 1, characterized in that: The outer wall of the opening and closing plate (303) is provided with a scale groove (406), and the scale groove (406) is a vertical groove. The inner wall of the sponge pad (306) is provided with a second groove (408), and the inner wall of the opening and closing plate (303) is provided with a first groove (407).

Images