A device and method for testing the low-temperature strength of cable protection pipes.

Abstract

This invention belongs to the technical field of strength testing devices and discloses a low-temperature strength testing device and method for cable protection pipes. It includes a low-temperature test chamber, with a drop weight testing machine fixedly connected to one side of the chamber. A V-shaped base is fixedly connected inside the drop weight testing machine. The device also includes an anti-air-entry feeding component, located inside the low-temperature test chamber. In this invention, an electric cylinder drives a hollow plate towards the discharge port. A pressure ring, under the action of a spring, first presses the end of the sealing cylinder to form a seal, then the telescopic cover opens. A pusher plate pushes the sample inside the sealing cylinder to the V-shaped base, where the drop weight testing machine performs a drop impact test. After the test, the electric cylinder retracts, and the hollow plate, through the unidirectional feeding component, moves the sample to the outside of the drop weight testing machine, completing two-stage conveying. This reduces the influx of ambient temperature air, avoids large temperature fluctuations inside the low-temperature test chamber, and improves the accuracy of the test data.

Description

Technical Field

[0001] This invention belongs to the technical field of strength testing devices, specifically a low-temperature strength testing device and method for cable protection pipes. Background Technology

[0002] Cable protection pipes are the core conduits used in power and communication engineering to cover and protect underground cables. They are widely made of high-density polyethylene, modified polypropylene, polyvinyl chloride and other polymer materials, and have advantages such as corrosion resistance, good insulation and convenient construction. In extremely cold regions and high-altitude low-temperature environments, cable protection pipes are subjected to low temperatures for a long time. Their low-temperature impact resistance directly determines the operational safety of cable lines. If the pipe material is too brittle at low temperatures, it is prone to cracking when subjected to soil settlement or external impact, which can lead to cable dampness, short circuits and power and communication failures. Therefore, low-temperature impact resistance is a mandatory indicator for the factory inspection of cable protection pipes.

[0003] After the cable protection pipes are manufactured, they need to be batch tested using a low-temperature strength testing device. The process involves placing pipes of a specified length into a low-temperature chamber and incubating them to the set temperature before transferring them to a drop hammer tester for impact strength testing. Currently, low-temperature strength testing often uses manual delivery or a single pusher-type conveyor to transfer the samples. Manual delivery is labor-intensive and exposes the samples for a long time. On the other hand, a single conveyor requires frequent opening of the low-temperature chamber door during sample delivery. Both manual delivery and single conveyor can lead to large temperature fluctuations inside the chamber, causing the cable protection pipe test temperature to deviate from the set value and affecting the low-temperature brittleness test results. In addition, after the test, the protective door of the testing machine must be manually opened and the samples removed, which is time-consuming and labor-intensive. Summary of the Invention

[0004] To address the problems mentioned in the background art, the present invention provides a low-temperature strength testing device for cable protection pipes, comprising a low-temperature test chamber, a drop weight testing machine fixedly connected to one side of the low-temperature test chamber, a V-shaped base fixedly connected inside the drop weight testing machine, and further comprising: An air-proof feeding component is installed inside the low-temperature test chamber and is used for multi-stage air-proof conveying of samples in the low-temperature test chamber. The anti-air-entry feeding component includes an electric cylinder fixedly connected to one side of the low-temperature test chamber. The output end of the electric cylinder extends into the interior of the low-temperature test chamber and is fixedly connected to a hollow plate. A rotating device is provided on the low-temperature test chamber. A pressing and pushing component is provided on the hollow plate. A discharge hole is opened on one side of the low-temperature test chamber. A telescopic cover is provided on one side of the low-temperature test chamber. A one-way feeding component connected to the pressing and pushing component is provided inside the V-shaped base. The self-priming ventilation unit is located inside the low-temperature test chamber to prevent ambient air from entering the low-temperature test chamber through the rotating device.

[0005] In the above technical solution, preferably, the rotating device includes a motor fixedly connected to one side of the low temperature test chamber, the output end of the motor penetrating into the interior of the low temperature test chamber and fixedly connected to a turntable, a sealing cylinder fixedly connected inside the turntable, sealing rings fixedly connected to both ends of the sealing cylinder, a temperature and humidity sensor fixedly connected to one side of the low temperature test chamber, and the detection end of the temperature and humidity sensor penetrating into the interior of the low temperature test chamber.

[0006] In the above technical solution, preferably, the pressing and pushing component includes a disc fixedly connected to a hollow plate, a spring fixedly connected to one side of the disc, a pressure ring fixedly connected to one end of the spring, the pressure ring being sleeved on the hollow plate, and a push plate located on one side of the pressure ring being fixedly connected to the hollow plate.

[0007] In the above technical solution, preferably, the telescopic cover includes a slide groove opened on one side of the low temperature test chamber, the slide groove is connected to the discharge hole, a cylinder is fixedly connected inside the drop hammer test machine, the output end of the cylinder is fixedly connected to an insulation plate through a connecting plate, and the insulation plate is slidably connected inside the slide groove.

[0008] In the above technical solution, preferably, the unidirectional feeding component includes a toothed plate fixedly connected to the bottom of the disc, one end of the toothed plate extending into the interior of the V-shaped base, a rotating rod movably connected to the interior of the V-shaped base via a bearing, a toothed ring movably connected to the rotating rod via a unidirectional bearing and meshing with the toothed plate, a turntable fixedly connected to the top of the rotating rod, a sliding rod fixedly connected to the edge of the top of the turntable, a scraper sleeved on the sliding rod, and two guide openings symmetrically opened on the V-shaped base, the scraper being sleeved on the V-shaped base through the guide openings.

[0009] In the above technical solution, preferably, the inside of the V-shaped base is hinged with a ratchet by a torsion spring shaft, and the turntable is provided with a tooth groove, with one end of the ratchet extending into the inside of the tooth groove.

[0010] In the above technical solution, preferably, the self-priming ventilation component includes a precooling jacket fixedly connected inside the low-temperature test chamber, a gas guide sleeve fixedly connected inside the precooling jacket, both the precooling jacket and the gas guide sleeve being fitted onto a toothed plate, a piston plate located inside the gas guide sleeve being fixedly connected to the toothed plate, an air inlet pipe connected to one side of the pressure ring, one end of the air inlet pipe connected to the precooling jacket, an exhaust pipe connected to one side of the gas guide sleeve, and one end of the exhaust pipe connected to the bottom of the hollow plate.

[0011] In the above technical solution, preferably, the piston plate is provided with an anti-backflow exhaust component, the anti-backflow exhaust component includes two square openings symmetrically opened on the piston plate, a sealing plate one is hinged to one side of the piston plate by a torsion spring hinge, one side of the sealing plate one is in contact with the surface of the air guide sleeve, and a sealing plate two is hinged to one side of the hollow plate by a torsion spring hinge, one side of the sealing plate two is in contact with the surface of the hollow plate.

[0012] In the above technical solution, preferably, a rubber sleeve is fixedly connected to the piston plate, the surface of the rubber sleeve is in contact with the inner wall of the air guide sleeve, and two guide rods are symmetrically fixedly connected inside the low temperature test chamber, with the disc sleeved on the guide rods.

[0013] A method for using a low-temperature strength testing device for cable protection pipes, comprising the aforementioned low-temperature strength testing device for cable protection pipes, and further comprising the following steps: S1: Place the sample to be tested into the sealed cylinder, close the door of the low temperature test chamber, start the low temperature test chamber to cool the sample to the set temperature; after the heat preservation is completed, the motor drives the turntable to rotate, so that the sealed cylinder containing the qualified sample is coaxially aligned with the discharge hole, and execute S2. S2: Start the electric cylinder to drive the hollow plate to extend towards the discharge hole. The pressure ring presses the end of the sealing cylinder to form a seal under the action of the spring. Then the telescopic cover opens. The electric cylinder continues to extend to compress the spring. The push plate pushes the sample in the sealing cylinder to the V-shaped base and executes S3.

[0014] S3: Start the drop hammer tester to complete the low-temperature impact strength test of the sample; after the test is completed, the electric cylinder begins to retract, and the hollow plate drives the one-way feeding component to push the tested sample to the recovery area outside the drop hammer tester. At the same time, the self-priming ventilation component draws the gas in the sealed cylinder to the pre-cooling jacket for cooling and recovery; the telescopic cover closes, all components reset, and the rotating device moves to the next sample station to prepare for the next test.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention uses an electric cylinder to move a hollow plate toward the discharge port. A pressure ring, under the action of a spring, first presses the end of the sealing cylinder to form a seal, then the telescopic cover opens. A pusher plate pushes the sample inside the sealing cylinder to the V-shaped base, where a drop hammer tester performs the drop hammer impact test. After the test, the electric cylinder retracts, and the hollow plate, through a one-way feeding component, moves the sample to the outside of the drop hammer tester, completing two-stage conveying. This reduces the influx of ambient air, avoids significant temperature fluctuations within the low-temperature test chamber, improves the accuracy of test data, ensures reliable sealing, and allows for shorter sample exposure time, facilitating rapid testing and saving time and effort.

[0016] Furthermore, although the sealing cylinder can seal the discharge hole, room temperature air is easily left inside. During resetting, this room temperature air will be brought into the low-temperature test chamber, easily contacting the sample and lowering its temperature. However, through the design of the pre-cooling jacket, air guide sleeve, and piston plate in the self-priming ventilation component, the toothed plate follows the electric cylinder to drive the piston plate to move back and forth inside the air guide sleeve, drawing out the room temperature air inside the sealing cylinder. The cold air inside the pre-cooling jacket is sent into the sealing cylinder through the air inlet pipe, preventing room temperature air from contacting the cable protection pipe sample inside the low-temperature test chamber. The ventilation is completed by transmission, reducing the temperature fluctuation of the cable protection pipe sample.

[0017] Furthermore, although the self-priming ventilation component can extract room temperature gas, when the piston plate moves in the reverse direction, the insufficiently cooled room temperature gas is prone to backflow, causing the gas to be discharged back into the sealing cylinder, affecting the temperature of the sample to be tested. However, through the structural design of the square opening, sealing plate one, and sealing plate two in the anti-backflow exhaust component, when the toothed plate drives the piston plate to move in the air guide sleeve, sealing plate one closes, and sealing plate two opens under air pressure to discharge the gas in the hollow plate and air guide sleeve; when the piston plate moves in the reverse direction, sealing plate two closes, and sealing plate one opens, and the cold air inside the pre-cooling jacket enters the air guide sleeve cavity on one side of the piston plate through the square opening, forming a one-way air path, ensuring that the gas has sufficient cooling time in the pre-cooling jacket, further improving the reliability of gas replacement. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a cross-sectional schematic diagram of the low-temperature test chamber of the present invention; Figure 3 This is a schematic diagram of the structure of the pressing and pushing component of the present invention; Figure 4 This is a schematic diagram of the V-shaped base of the present invention; Figure 5 This is a cross-sectional schematic diagram of the V-shaped base of the present invention; Figure 6 This is a cross-sectional schematic diagram of the precooling jacket of the present invention; Figure 7 This is a schematic diagram of the telescopic cover of the present invention; Figure 8 This is a schematic diagram of the piston plate of the present invention; Figure 9 This is a schematic diagram of the rotating device of the present invention.

[0019] In the diagram: 1. Low-temperature test chamber; 2. Drop weight tester; 3. V-shaped base; 4. Anti-air-entry feeding component; 41. Electric cylinder; 42. Hollow plate; 43. Rotating device; 431. Motor; 432. Support plate; 433. Sealing cylinder; 434. Sealing ring; 435. Temperature and humidity sensor; 44. Pressing and pushing component; 441. Disc; 442. Spring; 443. Pressure ring; 444. Push plate; 45. Discharge hole; 46. Telescopic cover; 461. Slide groove; 462. Cylinder; 463. Insulation board; 47. One-way feeding component; 471. Toothed plate; 472. Rotating rod; 473. Toothed ring; 474. Turntable; 475. Slide rod; 476. Scraper; 477. Guide port; 5. Self-priming ventilation component; 51. Pre-cooling jacket; 52. Air guide sleeve; 53. Piston plate; 54. Air inlet pipe; 55. Exhaust pipe; 6. Racket; 7. Tooth groove; 8. Anti-backflow exhaust component; 81. Square opening; 82. Sealing plate one; 83. Sealing plate two; 9. Rubber sleeve; 10. Guide rod. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] Example 1: As Figures 1 to 4 As shown, the present invention provides a low-temperature strength testing device for cable protection pipes, including a low-temperature test chamber 1, a drop weight tester 2 fixedly connected to one side of the low-temperature test chamber 1, a V-shaped base 3 fixedly connected inside the drop weight tester 2, and further including: The anti-air-entry feeding component 4 is installed inside the low-temperature test chamber 1 and is used to perform anti-air-entry multi-stage conveying of the sample in the low-temperature test chamber 1. The anti-air-entry feeding component 4 includes an electric cylinder 41 fixedly connected to one side of the low-temperature test chamber 1. The output end of the electric cylinder 41 extends into the interior of the low-temperature test chamber 1 and is fixedly connected to a hollow plate 42. A rotating device 43 is provided on the low-temperature test chamber 1. A pressing and pushing component 44 is provided on the hollow plate 42. A discharge hole 45 is opened on one side of the low-temperature test chamber 1. A telescopic cover 46 is provided on one side of the low-temperature test chamber 1. A one-way feeding component 47 connected to the pressing and pushing component 44 is provided inside the V-shaped base 3. The self-priming ventilation component 5 is installed inside the low-temperature test chamber 1 to prevent ambient air from entering the low-temperature test chamber 1 through the rotating device 43.

[0022] Specifically, both the low-temperature test chamber 1 and the drop weight tester 2 are mature technologies applied in the field of low-temperature impact testing of cable protection pipes. The low-temperature test chamber 1 is a test device used to simulate low-temperature environments, providing a stable low-temperature environment from -40℃ to 0℃ to achieve constant temperature insulation of the sample. The drop weight tester 2 generates quantitative impact energy by releasing a standard mass of dropping weights to complete the impact strength test of the pipe. By integrating an anti-air-entry feeding component 4 inside the low-temperature test chamber 1, a conveying process of sealing before feeding is realized, which solves the problem of a large amount of room temperature air rushing in when the door is opened in the traditional sample feeding method, avoids large fluctuations in the internal temperature of the low-temperature test chamber 1, and eliminates the need for an additional independent power source. All actions are driven by an electric cylinder 41, improving testing efficiency and data accuracy.

[0023] like Figure 2 and Figure 9 As shown, the rotating device 43 includes a motor 431 fixedly connected to one side of the low temperature test chamber 1. The output end of the motor 431 extends into the interior of the low temperature test chamber 1 and is fixedly connected to a support plate 432. A sealing cylinder 433 is fixedly connected inside the support plate 432. Sealing rings 434 are fixedly connected to both ends of the sealing cylinder 433. A temperature and humidity sensor 435 is fixedly connected to one side of the low temperature test chamber 1. The detection end of the temperature and humidity sensor 435 extends into the interior of the low temperature test chamber 1.

[0024] Specifically, the rotating device 43 can simultaneously accommodate multiple test samples, enabling continuous batch testing without frequently opening the door of the low-temperature test chamber 1 to replace samples, thus reducing the entry of ambient temperature air. The sealing rings 434 fixedly connected to both ends of the sealing cylinder 433 can form a double seal with the pressure ring 443 and the inner wall of the low-temperature test chamber 1, effectively blocking the gas flow between the inside of the sealing cylinder 433 and the inside of the low-temperature test chamber 1, preventing ambient temperature air from entering the depths of the low-temperature test chamber 1 through the gap of the sealing cylinder 433, ensuring temperature stability. The temperature and humidity sensor 435 can monitor the temperature and humidity inside the low-temperature test chamber 1 in real time.

[0025] like Figures 1 to 3 As shown, the pressing and pushing component 44 includes a disc 441 fixedly connected to the hollow plate 42. A spring 442 is fixedly connected to one side of the disc 441. A pressure ring 443 is fixedly connected to one end of the spring 442. The pressure ring 443 is sleeved on the hollow plate 42. A push plate 444 located on one side of the pressure ring 443 is fixedly connected to the hollow plate 42.

[0026] Specifically, spring 442 is a low-temperature resistant stainless steel spring; when electric cylinder 41 extends, pressure ring 443 first presses the end of sealing cylinder 433 to form a seal under the elastic force of spring 442, electric cylinder 41 continues to extend to compress spring 442, and push plate 444 then pushes the sample out smoothly to avoid seal failure during the pushing process.

[0027] like Figure 2 and Figure 7 As shown, the telescopic cover 46 includes a slide 461 opened on one side of the low temperature test chamber 1. The slide 461 is connected to the discharge hole 45. A cylinder 462 is fixedly connected inside the drop hammer test machine 2. The output end of the cylinder 462 is fixedly connected to an insulation plate 463 through a connecting plate. The insulation plate 463 is slidably connected inside the slide 461.

[0028] Specifically, the insulation plate 463 slides smoothly along the slide groove 461 under the drive of the cylinder 462, realizing the rapid opening and closing of the discharge hole 45; the telescopic cover 46 is precisely linked with the feeding sequence, opening only briefly when the sample enters or exits, and remaining closed at other times, further reducing the entry of room temperature air; the insulation plate 463 is made of high-density insulation material, which can effectively isolate the heat exchange between the inside of the low temperature test chamber 1 and the outside, reducing the energy consumption of the equipment.

[0029] like Figures 2 to 5 As shown, the unidirectional feeding component 47 includes a toothed plate 471 fixedly connected to the bottom of the disc 441. One end of the toothed plate 471 extends into the interior of the V-shaped base 3. A rotating rod 472 is movably connected to the interior of the V-shaped base 3 via a bearing. A toothed ring 473 that meshes with the toothed plate 471 is movably connected to the rotating rod 472 via a unidirectional bearing. A turntable 474 is fixedly connected to the top of the rotating rod 472. A sliding rod 475 is fixedly connected to the edge of the top of the turntable 474. A scraper 476 is sleeved on the sliding rod 475. Two guide ports 477 are symmetrically opened on the V-shaped base 3. The scraper 476 is sleeved on the V-shaped base 3 through the guide ports 477.

[0030] Specifically, the bottom of the scraper 476 has a sliding opening for the slide rod 475 to slide. When the electric cylinder 41 extends, the toothed plate 471 drives the toothed ring 473 to rotate freely. The toothed ring 473 does not drive the rotating rod 472 to rotate through the one-way bearing. When the electric cylinder 41 retracts, the toothed plate 471 drives the rotating rod 472 to rotate through the toothed ring 473 and the one-way bearing. The rotating rod 472 drives the turntable 474 and the slide rod 475 to rotate. The slide rod 475 drives the scraper 476 to slide along the V-shaped base 3, pushing the tested sample to the recovery area outside the drop hammer tester 2. The rotation angle of the turntable 474 and the slide rod 475 is 360 degrees, ensuring that the scraper 476 can be smoothly reset without additional power. The structure is simple and reliable.

[0031] like Figure 5 As shown, the inside of the V-shaped base 3 is hinged with a ratchet 6 via a torsion spring shaft, and the turntable 474 has a toothed groove 7, with one end of the ratchet 6 extending into the inside of the toothed groove 7.

[0032] Specifically, the ratchet 6 and the tooth groove 7 work together to form a check valve structure, which can prevent the turntable 474 from reversing during the material pushing process of the scraper 476, ensuring the stability of the scraper 476's movement direction and avoiding sample not being pushed into place or jamming; the torsion spring shaft provides continuous clamping force to the ratchet 6, ensuring that the ratchet 6 is always locked inside the tooth groove 7, the check valve effect is reliable and it is not easy to fail.

[0033] like Figures 2 to 6 As shown, the self-priming ventilation component 5 includes a pre-cooling jacket 51 fixedly connected inside the low-temperature test chamber 1. An air guide sleeve 52 is fixedly connected inside the pre-cooling jacket 51. Both the pre-cooling jacket 51 and the air guide sleeve 52 are fitted onto the toothed plate 471. A piston plate 53 located inside the air guide sleeve 52 is fixedly connected to the toothed plate 471. An air inlet pipe 54 is connected to one side of the pressure ring 443. One end of the air inlet pipe 54 is connected to the pre-cooling jacket 51. An exhaust pipe 55 is connected to one side of the air guide sleeve 52. One end of the exhaust pipe 55 is connected to the bottom of the hollow plate 42.

[0034] Specifically, the toothed plate 471 follows the electric cylinder 41 to drive the piston plate 53 to reciprocate inside the air guide sleeve 52, drawing in the ambient temperature air inside the sealing cylinder 433. The cold air inside the pre-cooling jacket 51 is sent into the sealing cylinder 433 through the air inlet pipe 54, preventing the ambient temperature air from contacting the cable protection tube sample inside the low temperature test chamber 1. The air exchange is completed by transmission, reducing the temperature fluctuation of the cable protection tube sample.

[0035] like Figure 3 and Figure 6 As shown, the piston plate 53 is provided with an anti-backflow exhaust component 8, which includes two square openings 81 symmetrically opened on the piston plate 53. A sealing plate 1 82 is hinged to one side of the piston plate 53 by a torsion spring hinge. One side of the sealing plate 1 82 is in contact with the surface of the air guide sleeve 52. A sealing plate 2 83 is hinged to one side of the hollow plate 42 by a torsion spring hinge. One side of the sealing plate 2 83 is in contact with the surface of the hollow plate 42.

[0036] Specifically, when the toothed plate 471 drives the piston plate 53 to move within the air guide sleeve 52, the first sealing plate 82 closes, and the second sealing plate 83 opens under air pressure to discharge the gas inside the hollow plate 42 and the air guide sleeve 52; when the piston plate 53 moves in the opposite direction, the second sealing plate 83 closes, and the first sealing plate 82 opens, allowing the cold air inside the pre-cooling jacket 51 to enter the air guide sleeve 52 cavity on one side of the piston plate 53 through the square opening 81, forming a one-way air path. This ensures that the gas has sufficient cooling time within the pre-cooling jacket 51, further improving the reliability of gas replacement.

[0037] like Figure 3 and Figure 8As shown, a rubber sleeve 9 is fixedly connected to the piston plate 53. The surface of the rubber sleeve 9 is in contact with the inner wall of the air guide sleeve 52. Two guide rods 10 are symmetrically fixedly connected inside the low temperature test chamber 1, and the disc 441 is sleeved on the guide rods 10.

[0038] Specifically, the rubber sleeve 9 fills the gap between the piston plate 53 and the inner wall of the air guide sleeve 52, improving the sealing performance of the piston plate 53 and ensuring the efficiency of air extraction and injection; the two guide rods 10 provide support and guidance for the disc 441, preventing the disc 441 from tilting or shifting during movement, ensuring that the pressure ring 443 and the end of the sealing cylinder 433 are coaxially aligned, and the sealing pressure is evenly distributed; a low-temperature resistant sealing ring one is provided at the gap between the low-temperature test chamber 1 and the toothed plate 471, a low-temperature resistant sealing ring two is provided at the gap between the air guide sleeve 52 and the toothed plate 471, and a low-temperature resistant sealing ring three is provided at the gap between the low-temperature test chamber 1 and the output shaft of the motor 431. Conventional low-temperature resistant sealing rings can also be provided at the joint gaps of other components to form an all-round sealing system, completely blocking the infiltration channel of ambient temperature air and reducing the leakage of cold energy.

[0039] Working principle and usage process of this invention: When in use, the cable protection pipe sample to be tested is placed in the sealing cylinder 433, the door of the low temperature test chamber 1 is closed, the low temperature test chamber 1 is started to cool the sample to the set test temperature and keep it warm. The temperature and humidity sensor 435 monitors the temperature and humidity inside the low temperature test chamber 1 in real time. After the heat preservation is completed, the motor 431 drives the support plate 432 to rotate, so that the sealing cylinder 433 and the discharge hole 45 are coaxially aligned. When the electric cylinder 41 is activated, it drives the hollow plate 42 to extend towards the discharge hole 45. Under the elastic force of the spring 442, the pressure ring 443 first presses the end of the sealing cylinder 433, forming a reliable seal with the sealing rings 434 at both ends of the sealing cylinder 433. Then, the cylinder 462 drives the insulation plate 463 to slide open along the slide groove 461. The electric cylinder 41 continues to extend and compress the spring 442. The push plate 444 pushes the sample in the sealing cylinder 433 onto the V-shaped base 3. The toothed plate 471 and the piston plate 53 move synchronously. The toothed plate 471 drives the toothed ring 473 to rotate freely on the one-way bearing, while the rotating rod 472 does not rotate. Then, the drop hammer tester 2 is started to complete the low-temperature impact strength test of the sample; after the test is completed, the electric cylinder 41 begins to retract, the toothed plate 471 retracts synchronously with the disc 441, and drives the toothed ring 473 and the rotating rod 472 to rotate synchronously through the one-way bearing. The rotating rod 472 drives the turntable 474 and the slide rod 475 to rotate, and the slide rod 475 drives the scraper 476 to slide along the V-shaped base 3, pushing the tested sample to the recycling area outside the drop hammer tester 2. Simultaneously, when the piston plate 53 moves forward, the first sealing plate 82 opens and the second sealing plate 83 closes, and the cold air inside the pre-cooling jacket 51 enters the air guide sleeve 52 through the square opening 81; when the piston plate 53 resets, the first sealing plate 82 closes and the second sealing plate 83 opens, and the gas inside the air guide sleeve 52 is sent into the sealing cylinder 433 through the exhaust pipe 55 and the hollow plate 42. Some of the cold air will be directly discharged into the interior of the drop hammer test machine 2, and another part of the cold air will remain in the sealing cylinder 433. The room temperature air mixed with cold air is drawn into the pre-cooling jacket 51 through the exhaust pipe 55 for cooling, thus completing the gas circulation and replacement. Finally, cylinder 462 drives insulation plate 463 to slide along slide groove 461 to seal discharge hole 45, electric cylinder 41 continues to retract to drive all components to reset to the initial position, motor 431 drives support plate 432 to rotate to transfer the next test sample to discharge hole 45 position, thereby achieving the effect of preventing air intake and multi-stage feeding.

[0040] Example 2: A method for using a low-temperature strength testing device for cable protection pipes, comprising the aforementioned low-temperature strength testing device for cable protection pipes, and further comprising the following steps: S1: Place the test sample into the sealed cylinder 433, close the door of the low temperature test chamber 1, and start the low temperature test chamber 1 to cool the sample to the set temperature; after the heat preservation is completed, the motor 431 drives the support plate 432 to rotate, so that the sealed cylinder 433 containing the qualified sample is coaxially aligned with the discharge hole 45, and execute S2. S2: Start the electric cylinder 41 to drive the hollow plate 42 to extend towards the discharge hole 45. The pressure ring 443 presses the end of the sealing cylinder 433 to form a seal under the action of the spring 442. Then the telescopic cover 46 opens. The electric cylinder 41 continues to extend and compress the spring 442. The push plate 444 pushes the sample in the sealing cylinder 433 onto the V-shaped base 3, and executes S3.

[0041] S3: Start the drop hammer tester 2 to complete the low-temperature impact strength test of the sample; after the test is completed, the electric cylinder 41 begins to retract, the hollow plate 42 drives the one-way feeding component 47 to push the tested sample to the recovery area outside the drop hammer tester 2, and at the same time the self-priming ventilation component 5 draws the gas in the sealing cylinder 433 to the pre-cooling jacket 51 for cooling and recovery; the telescopic cover 46 is closed, all components are reset, and the rotating device 43 rotates to the next sample station to prepare for the next test.

[0042] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0043] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A low-temperature strength testing device for cable protection pipes, comprising a low-temperature test chamber (1), wherein a drop weight tester (2) is fixedly connected to one side of the low-temperature test chamber (1), and a V-shaped base (3) is fixedly connected inside the drop weight tester (2), characterized in that, Also includes: An anti-air-entry feeding component (4) is installed inside the low-temperature test chamber (1) and is used to perform anti-air-entry multi-stage conveying of the sample in the low-temperature test chamber (1). The anti-air-entry feeding component (4) includes an electric cylinder (41) fixedly connected to one side of the low temperature test chamber (1). The output end of the electric cylinder (41) extends into the interior of the low temperature test chamber (1) and is fixedly connected to a hollow plate (42). A rotating device (43) is provided on the low temperature test chamber (1). A pressing and pushing component (44) is provided on the hollow plate (42). A discharge hole (45) is opened on one side of the low temperature test chamber (1). A telescopic cover (46) is provided on one side of the low temperature test chamber (1). A one-way feeding component (47) connected to the pressing and pushing component (44) is provided inside the V-shaped base (3). The self-priming ventilation component (5) is installed inside the low temperature test chamber (1) to prevent room temperature air from entering the low temperature test chamber (1) through the rotating device (43).

2. The low-temperature strength testing device for cable protection pipes according to claim 1, characterized in that: The rotating device (43) includes a motor (431) fixedly connected to one side of the low temperature test chamber (1). The output end of the motor (431) extends into the interior of the low temperature test chamber (1) and is fixedly connected to a support plate (432). A sealing cylinder (433) is fixedly connected inside the support plate (432). Both ends of the sealing cylinder (433) are fixedly connected to sealing rings (434). A temperature and humidity sensor (435) is fixedly connected to one side of the low temperature test chamber (1). The detection end of the temperature and humidity sensor (435) extends into the interior of the low temperature test chamber (1).

3. The low-temperature strength testing device for cable protection pipes according to claim 1, characterized in that: The pressing and pushing component (44) includes a disc (441) fixedly connected to a hollow plate (42), a spring (442) fixedly connected to one side of the disc (441), a pressure ring (443) fixedly connected to one end of the spring (442), the pressure ring (443) being sleeved on the hollow plate (42), and a push plate (444) located on one side of the pressure ring (443) fixedly connected to the hollow plate (42).

4. The low-temperature strength testing device for cable protection pipes according to claim 1, characterized in that: The telescopic cover (46) includes a slide groove (461) opened on one side of the low temperature test chamber (1). The slide groove (461) is connected to the discharge hole (45). A cylinder (462) is fixedly connected inside the drop hammer test machine (2). The output end of the cylinder (462) is fixedly connected to an insulation plate (463) through a connecting plate. The insulation plate (463) is slidably connected inside the slide groove (461).

5. The low-temperature strength testing device for cable protection pipes according to claim 3, characterized in that: The one-way feeding component (47) includes a toothed plate (471) fixedly connected to the bottom of the disc (441). One end of the toothed plate (471) extends into the interior of the V-shaped base (3). A rotating rod (472) is movably connected to the interior of the V-shaped base (3) via a bearing. A toothed ring (473) that meshes with the toothed plate (471) is movably connected to the rotating rod (472) via a one-way bearing. A turntable (474) is fixedly connected to the top of the rotating rod (472). A sliding rod (475) is fixedly connected to the edge of the top of the turntable (474). A scraper (476) is sleeved on the sliding rod (475). Two guide ports (477) are symmetrically opened on the V-shaped base (3). The scraper (476) is sleeved on the V-shaped base (3) through the guide ports (477).

6. The low-temperature strength testing device for cable protection pipes according to claim 5, characterized in that: The V-shaped base (3) has ratchet teeth (6) hinged inside by a torsion spring shaft, and the turntable (474) has a toothed groove (7) with one end of the ratchet teeth (6) extending into the inside of the toothed groove (7).

7. The low-temperature strength testing device for cable protection pipes according to claim 3, characterized in that: The self-priming ventilation component (5) includes a precooling jacket (51) fixedly connected inside the low-temperature test chamber (1). A guide sleeve (52) is fixedly connected inside the precooling jacket (51). The precooling jacket (51) and the guide sleeve (52) are both sleeved on the toothed plate (471). A piston plate (53) located inside the guide sleeve (52) is fixedly connected on the toothed plate (471). An air inlet pipe (54) is connected to one side of the pressure ring (443). One end of the air inlet pipe (54) is connected to the precooling jacket (51). An exhaust pipe (55) is connected to one side of the guide sleeve (52). One end of the exhaust pipe (55) is connected to the bottom of the hollow plate (42).

8. The low-temperature strength testing device for cable protection pipes according to claim 7, characterized in that: The piston plate (53) is provided with an anti-backflow exhaust component (8), which includes two square openings (81) symmetrically opened on the piston plate (53). A sealing plate (82) is hinged to one side of the piston plate (53) by a torsion spring hinge. One side of the sealing plate (82) is in contact with the surface of the air guide sleeve (52). A sealing plate (83) is hinged to one side of the hollow plate (42) by a torsion spring hinge. One side of the sealing plate (83) is in contact with the surface of the hollow plate (42).

9. The low-temperature strength testing device for cable protection pipes according to claim 7, characterized in that: A rubber sleeve (9) is fixedly connected to the piston plate (53). The surface of the rubber sleeve (9) is in contact with the inner wall of the air guide sleeve (52). Two guide rods (10) are symmetrically fixedly connected inside the low temperature test chamber (1). The disc (441) is sleeved on the guide rods (10).

10. A method for using a low-temperature strength testing device for cable protection pipes, characterized in that: The low-temperature strength testing device for the cable protection pipe according to any one of claims 1-9 further includes the following steps: S1: Place the test sample into the sealed cylinder (433), close the door of the low temperature test chamber (1), start the low temperature test chamber (1) to cool the sample to the set temperature; after the heat preservation is completed, the motor (431) drives the support plate (432) to rotate, so that the sealed cylinder (433) containing the qualified sample is coaxially aligned with the discharge hole (45), and execute S2; S2: Start the electric cylinder (41) to drive the hollow plate (42) to extend towards the discharge hole (45). The pressure ring (443) presses the end of the sealing cylinder (433) to form a seal under the action of the spring (442). Then the telescopic cover (46) opens. The electric cylinder (41) continues to extend to compress the spring (442). The push plate (444) pushes the sample in the sealing cylinder (433) onto the V-shaped base (3) and executes S3. 11.S3: Start the drop hammer tester (2) to complete the low-temperature impact strength test of the sample; after the test is completed, the electric cylinder (41) begins to retract, the hollow plate (42) drives the one-way feeding part (47) to push the tested sample to the recovery area outside the drop hammer tester (2), and at the same time the self-priming air exchange part (5) draws the gas in the sealing cylinder (433) to the pre-cooling jacket (51) for cooling and recovery; the telescopic cover (46) is closed, all parts are reset, and the rotating device (43) rotates to the next sample station to prepare for the next test.

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