Impact resistance detection device for mining air shaft explosion door
By introducing a dual-limiting structure and a real-time monitoring system into the impact resistance testing device for mining materials, the problem of limit failure in existing devices has been solved, achieving a safe and controllable testing process and highly accurate test results.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SHANDONG SHIJI TAIDA MINING EQUIP CO LTD
- Filing Date
- 2026-01-23
- Publication Date
- 2026-05-08
AI Technical Summary
Existing impact resistance testing devices for mining materials have shortcomings in safety protection design. The single electrical limit switch is easily affected by circuit failure, which can lead to limit switch failure and pose a safety hazard.
It adopts a dual limit structure, including mechanical limit and electrical limit, combined with a force calculation module and an impact warning module. The impact process is monitored in real time through an angle sensor and a camera, and the test parameters are dynamically adjusted to prevent misoperation and material damage.
It significantly improves the safety and accuracy of the testing process, ensures controllable hammer limit, avoids accidental impacts, and enhances the reliability of testing data and intelligent decision-making capabilities.
Smart Images
Figure CN121994616A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of testing equipment for mining materials, and in particular to a device for testing the impact resistance of explosion-proof doors for mine ventilation shafts. Background Technology
[0002] The explosion-proof and impact-resistant properties of mining materials are directly related to the safety and stability of underground mining operations. They are key factors in ensuring the normal operation of mining equipment and preventing safety accidents such as collapses and explosions. Therefore, accurate and safe explosion-proof and impact-resistant testing of mining materials is an indispensable and important step in mine safety production. Currently, there are various impact resistance testing devices for mining materials in the industry. Their core principle is to use a swinging hammer to impact the material under test to simulate the impact load in actual working conditions, thereby evaluating the material performance. However, existing testing devices have significant shortcomings in safety protection design and cannot meet the stringent safety requirements of mining operations for testing equipment.
[0003] The existing hammer limit structure mostly adopts a single limit method, such as the traditional electric control limit that uses a cylinder to push the limit rod to limit the hammer head and prevent the hammer head from sagging. This lacks double protection and the single electric limit is easily affected by factors such as circuit failure and signal interference, which can lead to limit failure. If the operator accidentally touches the control switch or the operation is improper, the hammer can easily be released unexpectedly, causing impact injury to personnel and equipment in the surrounding area of the detection area. Therefore, the above-mentioned problems need to be addressed and improved. Summary of the Invention
[0004] The purpose of this invention is to address the shortcomings of existing technologies by proposing an impact resistance testing device for explosion-proof doors in mine ventilation shafts.
[0005] To achieve the above objectives, the present invention adopts the following technical solution: a mine ventilation shaft explosion-proof door impact resistance testing device, including a testing platform, a driving platform installed in the middle of the top surface of the testing platform, a placement platform provided at the front end of the testing platform, a testing area provided between the two placement platforms, a scale plate installed at the front end of the top surface of the driving platform, a hammer block rotatably connected to the front end of the scale plate, and a protective component for limiting the hammer block installed on the top surface of the testing platform. The controller of the detection device is equipped with a force calculation module and an impact early warning module. The force calculation module calculates the increment of gravitational potential energy based on inherent parameters such as hammer mass and pendulum length; it introduces a real-time energy loss coefficient, which comprehensively considers factors such as mechanical wear, lifting angle, material properties and component aging, and dynamically corrects it through a multi-factor product model; based on the momentum theorem and energy conservation, it calculates the impact force and impact stress. The impact warning module performs grayscale processing and contour extraction on the image data to mark the contour line of the impact position; it monitors the offset angle of the contour line in real time during the impact and compares it with the preset limit offset angle. Combining the limit stress of similar materials in historical data, the system calculates the limit impact force and compares it with the current real-time impact force to obtain the impact force difference; if the offset angle is close to or reaches the maximum offset angle, the system automatically issues a warning.
[0006] Preferably, the data analysis steps of the force calculation module are as follows: M1: Lifting angle based on angle sensor data Calculate the increment of the hammer's gravitational potential energy. The collected angle data were subjected to outlier detection and preprocessing, and data exceeding the mean ± 3 times the standard deviation were removed to obtain valid angle data. M2: Calculate the real-time energy loss coefficient based on factors such as mechanical wear, lifting angle deviation, material elastic modulus, and component aging. The individual factors are obtained through a product model. The value is substituted into the calculation of the impact force. Furthermore, combined with the impact contact area Calculate impact stress This enables dynamic correction and output of impact parameters.
[0007] Preferably, the data analysis steps of the force calculation module are as follows: N1: The camera captures images of the material under test, performs grayscale processing and contour extraction, marks the contour line at the impact position, and monitors its offset angle in real time during the impact process. N2: Calculates the ultimate stress of similar materials from the historical database. Based on the current impact contact area Calculate the ultimate impact force ; its real-time impact force and Compare and calculate the difference in impact force. If the detected contour line offset angle is close to or exceeds the preset maximum offset angle The system will automatically issue a warning and can, based on... The subsequent test parameters are dynamically adjusted in relation to the offset angle.
[0008] Preferably, a positioning sensor for detecting the number of swings of the hammer is installed at the lower center of the front end of the drive platform, and a gripper adapted to the protective component is sleeved on the outside of the hammer. The gripper has an automatic limiting area on one side and a manual limiting area on the other side.
[0009] Preferably, the protective component includes a protective platform installed on one side of the top surface of the drive platform. The protective platform has a drive groove adapted to the automatic limit area and a reset hole adapted to the manual limit area on one side. The front end of the reset hole has a drive hole.
[0010] Preferably, an electric push cylinder is installed in the drive slot, and the output shaft of the electric push cylinder is connected to a limit rod placed in the automatic limit area via a coupling. The outer side of the limit rod abuts against the inner side of the grab hook, and a protective rod is slidably connected in the reset hole.
[0011] Preferably, a limiting block that fits against the inner wall of the drive hole is installed on the outer side of the protective rod, and a first spring that is placed inside the drive hole is sleeved on the outer side of the protective rod; the first spring is placed between the rear end of the limiting block and the drive hole, and the other end of the protective rod is placed in the manual limiting area and abuts against the inner side of the grab hook.
[0012] Preferably, a positioning rod is installed on the other side of the top surface of the protective platform, and an installation block is installed on the other end of the positioning rod. Positioning blocks are installed on both sides of the inner cavity of the installation block, and pressure sensors are installed below the two positioning blocks. An impact block is slidably connected to the inner side of the installation block. Sliding grooves adapted to the sliding limit of the positioning blocks are opened on both sides of the impact block. A second spring is fixedly connected to the bottom surface of the sliding groove, and a bonding plate that abuts against the pressure sensor is fixedly connected to the other end of the second spring.
[0013] Compared with the prior art, the beneficial effects of the present invention are: 1. The protective components enable safe and controllable limiting of the hammer block, significantly improving the safety of the testing process. The protective rod, together with the first spring, abuts against the manual limiting area of the grab hook, forming a mechanical limiting guarantee. Only by sequentially releasing the electrical limit of the electric push cylinder and the mechanical limit provided by the protective rod can the hammer block be released, fundamentally avoiding accidental impacts caused by misoperation. The first spring continuously provides a clamping force to the protective rod through the limiting block, ensuring the stability of the manual limiting. 2. Based on the lifting angle data collected in real time by the angle sensor, the force calculation module filters out outliers and preprocesses them using the mean and standard deviation to ensure the reliability of the input parameters. It introduces a multi-factor real-time energy loss coefficient that includes mechanical wear, lifting angle, material properties and component aging, and uses a product model to dynamically correct the calculation process, so that the calculated impact force and impact stress are more in line with the actual working conditions, significantly improving the accuracy and repeatability of the test data, and providing a scientific basis for the evaluation of the impact resistance performance of materials. 3. The impact warning module acquires real-time images of the material under test using a camera. Through grayscale processing and contour extraction technology, it monitors the offset angle of the material contour during the impact process in real time. Combined with the ultimate stress data of similar materials in the historical database, it dynamically calculates the ultimate impact force and compares it with the current real-time impact force. When the offset angle approaches or exceeds the preset threshold, the system automatically issues an early warning and, if necessary, dynamically adjusts the test parameters based on the relationship between the impact force difference and the offset. This effectively avoids overload damage to the material during testing and improves the safety control and intelligent decision-making capabilities of the testing process. Attached Figure Description
[0014] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings: Figure 1 This is a schematic diagram of the overall structure proposed in this invention; Figure 2 This is a schematic diagram of the protective rod structure proposed in this invention; Figure 3 This is a schematic diagram of the positioning sensor structure proposed in this invention; Figure 4 This is a schematic diagram of the pressure sensor structure proposed in this invention; Figure 5 The present invention proposes Figure 2 Enlarged diagram of part A in the middle; Figure 6 The present invention proposes Figure 3 Enlarged diagram of section B; Figure 7 This is a flowchart of the system proposed in this invention.
[0015] The numbers in the diagram are: 1. Detection table; 2. Drive table; 3. Placement table; 4. Dial; 5. Hammer block; 6. Protective table; 7. Electric pusher cylinder; 8. Protective rod; 9. Grab hook; 10. First spring; 11. Positioning rod; 12. Impact block; 13. Second spring; 14. Mounting block; 15. Pressure sensor; 16. Position sensor. Detailed Implementation
[0016] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.
[0017] Example 1: See Figures 1 to 6This invention discloses a mine ventilation shaft explosion-proof door impact resistance testing device, comprising a testing platform 1, which ensures the stability of the entire device during subsequent hammer impact testing; a drive platform 2 is installed in the middle of the top surface of the testing platform 1, which facilitates the installation of a drive assembly for lifting the hammer 5 and a control system for controlling the drive assembly; a placement platform 3 is provided at the front end of the testing platform 1, which facilitates the subsequent use of external limiting components to limit the material to be tested; a testing area is provided between the two placement platforms 3; a scale 4 is installed at the front end of the top of the drive platform 2, which allows the operator to manually adjust the pointer installed above to adjust the hammer impact force. A hammer 5 is rotatably connected to the front end of the dial 4, which facilitates impact testing of the material to be tested placed in the testing area. A protective component for limiting the hammer 5 is installed on the top surface of the testing table 1. A position sensor 16 for detecting the number of swings of the hammer 5 is installed at the lower center of the front end of the drive table 2. The position sensor 16 can detect the number of swings of the hammer 5 and whether the hammer 5 is in the initial position. The model of the position sensor 16 is KJT-FS50. A hook 9 adapted to the protective component is sleeved on the outside of the hammer 5. The hook 9 has an automatic limit area on one side and a manual limit area on the other side. The hook 9 facilitates the subsequent use of the protective component to limit the hammer 5. In this invention, the protective assembly includes a protective platform 6 installed on one side of the top surface of the drive platform 2. One side of the protective platform 6 has a drive groove adapted to the automatic limit area and a reset hole adapted to the manual limit area. A drive hole is formed at the front end of the reset hole. The protective platform 6 facilitates the subsequent installation of the limit electric cylinder 7, the protective rod 8, and the first spring 10, respectively, in conjunction with the drive groove, reset hole, and drive hole. The protective platform 6 is formed by external grooving and hole-making processes to create the drive groove, reset hole, and drive hole. The electric cylinder 7 is installed in the drive groove. The output shaft of the electric cylinder 7 is connected via a coupling to a limit rod placed in the automatic limit area. The outer side of the limit rod abuts against the inner side of the grab hook 9. The electric cylinder 7 facilitates the electrical limit of the grab hook 9 in conjunction with the limit rod. When it is necessary to release the electrical limit on the grab hook 9... When the air limit is applied, simply retracting the electric cylinder 7 will release the electrical limit. A protective rod 8 is slidably connected inside the reset hole, facilitating manual limiting of the grab hook 9. Only after releasing the electrical limit and then the manual limit can the grab hook 9 disengage, thereby allowing the hammer block 5 to disengage. Releasing the manual limit simply requires pulling the protective rod 8 in conjunction with the limiting block to compress the first spring 10 and retract it. A limiting block that fits against the inner wall of the drive hole is installed on the outer side of the protective rod 8, and the first spring 10, placed inside the drive hole, is sleeved on the outer side of the protective rod 8. The first spring 10 is positioned between the rear end of the limiting block and the drive hole, and the other end of the protective rod 8 is positioned in the manual limiting area and abuts against the inner side of the grab hook 9. The first spring 10 facilitates lifting the first spring 10 in conjunction with the limiting block and the drive hole. The driving force for the driving guard rod 8 and the limiting hook 9 is provided; a positioning rod 11 is installed on the other side of the top surface of the guard platform 6, which facilitates the fixing of the mounting block 14 by external welding process; the other end of the positioning rod 11 is installed with the mounting block 14, and positioning blocks are installed on both sides of the inner cavity of the mounting block 14. Pressure sensors 15 are installed below the two positioning blocks. The mounting block 14 facilitates the fixing of the positioning blocks by external welding process and the installation of the pressure sensors 15 by external bonding process. The mounting block 14, together with the pressure sensors 15, detects the positioning status of the subsequent impact block 12, thereby determining whether the hammer block 5 is in place each time it is raised. During the raising of the hammer block 5, the operator needs to stand at the rear of the equipment and manually pull out the guard rod 8, and cooperate with the control system. The control drive assembly lifts the hammer block 5; and the mounting block 14 has an impact block 12 slidably connected to its inner side. Both sides of the impact block 12 are provided with sliding grooves adapted to the sliding limit of the positioning block. The impact block 12 can slide relative to the positioning block after being hit by the hammer block 5, so that the second spring 13 can cooperate with the bonding plate to squeeze the pressure sensor 15. When the pressure sensor 15 detects the predetermined pressure, the external drive assembly is turned off to prevent the hammer block 5 from being over-lifted. The pressure sensor 15 is model YBB-SS1000N. The second spring 13 is fixed to the bottom surface of the sliding groove. The other end of the second spring 13 is fixed to the bonding plate that abuts against the pressure sensor 15. The second spring 13 can provide a reset driving force for the impact block 12 after the hammer block 5 is released.
[0018] Working Principle: When using this invention, the operator first powers on the equipment, then places the mining material to be tested in the testing area between the placement platforms 3. Then, according to the testing requirements, the pointer position is adjusted via the dial 4 to determine the impact force. Simultaneously, the position sensor 16 confirms the initial position of the hammer block 5. At this point, the operator needs to stand at the rear of the equipment and pull the protective rod 8 placed inside the protective platform 6 to retract it, preventing subsequent interference with the hook 9 during movement. Then, the drive assembly inside the drive platform 2 is activated via the external control board to lift the hammer block 5. As the hammer block 5 rises, the hook 9 moves. When the hammer block 5 rises to a predetermined angle, its end strikes the impact block 12. The impact block 12 slides along the positioning block inside the mounting block 14 via the sliding grooves on both sides. At this time, the mounting block 14 is limited by the positioning rod 11, compressing the second spring 13, causing... The bonding plate in the sliding groove presses the pressure sensor 15. After the pressure sensor 15 detects the preset pressure value, it shuts off the drive assembly. At this time, the hammer block 5 is also limited by the protective rod 8 and the limit rod under the cooperation of the hook 9. When it is necessary to release the hammer block 5, the operator stands at the rear of the equipment and manually pulls the protective rod 8, which drives the limit block to squeeze the first spring 10, so that the protective rod 8 is separated from the manual limit area of the hook 9. Then, the control board sends a command to control the electric push cylinder 7 to retract the output shaft. The limit rod is simultaneously separated from the automatic limit area of the hook 9, releasing the limit on the hook 9. At this time, the hammer block 5 swings downward under the action of gravity to conduct an impact test on the mining materials in the detection area. At this time, the detection table 1 will play a role in stabilizing the device. After the test is completed, the operator removes the tested mining materials and comprehensively analyzes and evaluates the explosion-proof and impact-resistant performance of the mining materials through the data collected by the control system. Example 2: See Figure 7 The controller of the detection device is equipped with a force calculation module and an impact early warning module. The force calculation module calculates the increment of gravitational potential energy based on inherent parameters such as hammer mass and pendulum length; it introduces a real-time energy loss coefficient, which comprehensively considers factors such as mechanical wear, lifting angle, material properties and component aging, and dynamically corrects it through a multi-factor product model; based on the momentum theorem and energy conservation, it calculates the impact force and impact stress. The impact warning module performs grayscale processing and contour extraction on the image data to mark the contour line of the impact position; it monitors the offset angle of the contour line in real time during the impact and compares it with the preset limit offset angle. Combining the limit stress of similar materials in historical data, the system calculates the limit impact force and compares it with the current real-time impact force to obtain the impact force difference; if the offset angle is close to or reaches the maximum offset angle, the system automatically issues a warning. During the impact resistance test, the distance between the lower hammer block 5 and the center of rotation is... The mass of hammer block 5 is The angle at which it is raised is The acceleration due to gravity is Then, hammer block 5 is raised from its initial vertical position to an angle. At that time, the height at which the center of gravity rises Increment of gravitational potential energy Impact strength It is the instantaneous force of kinetic energy during the impact time, according to the momentum theorem. , The impact contact time and momentum change of the tested material , The linear velocity of the hammer at the moment of impact; rotational kinetic energy. When energy loss is ignored, the gravitational potential energy is completely converted into the rotational kinetic energy of the hammer, that is... In reality, the energy loss coefficient is... ,but Through impact force and impact contact area Calculated impact stress ; An angle sensor is set to acquire the angle data of the hammer block 5 being raised, and the acquired angle data is preprocessed. The data obtained after preprocessing is recorded as valid data. The collected data was sorted according to the collection time, and corresponding items collected at the same time were sorted. averaging the data and standard deviation The calculation, and the mean obtained from the calculation. and standard deviation Collect data fluctuation range for corresponding items The system is configured to compare the collected data for a given item with its fluctuation range, mark data outside the fluctuation range as outliers, and record the number of outliers. ,like If the collected data is abnormal, the data will be re-tested; if If outliers are removed, the mean of the remaining corresponding test data after outlier removal is calculated. The calculation, and the mean obtained from the calculation. As the corresponding data detected at the corresponding time; Historical data is acquired, and impact stress data for corresponding materials is retrieved from the historical data. The retrieved impact stress data is then categorized according to the corresponding material, and the impact stress data for each material within the same category are sorted by magnitude and correlated with material integrity to obtain the ultimate stress data for the corresponding material. When conducting impact tests on materials of different shapes and sizes, the impact contact area is considered. If the impact stress changes, the angle of the object being lifted will be automatically adjusted.
[0019] Loss coefficient caused by mechanical wear ,in This is the lubrication condition coefficient. For usage duration, This is the friction loss time decay coefficient. This is the gap loss coefficient. and These are the real-time and initial rotational shaft clearances, respectively. Loss coefficient caused by lifting angle , This represents the maximum loss coefficient at the optimal angle. The angle deviation loss coefficient, To achieve the optimal lifting angle; Loss coefficient caused by material properties , This serves as the reference coefficient for material deformation loss. The elastic modulus attenuation coefficient, The elastic modulus of the material being tested. and These are the impact contact time and the reference contact time, respectively. Loss coefficient caused by component aging , This is the spring fatigue coefficient. This is the aging loss coefficient. This represents the cumulative number of tests. Real-time energy loss coefficient The coefficients of the corresponding terms were obtained through experimental fitting.
[0020] A camera is set on the testing table 1 to acquire image data of the location where the material to be tested is placed, and the acquired image data is processed into grayscale. The grayscale image is divided into several grayscale blocks of the same size according to the size of the pixel blocks, and the grayscale blocks are numbered according to the number of rows and columns of the grayscale image.
[0021] The gray value of a gray block at any random location on the grayscale image is compared with the gray value range of the standard part of the material being tested. The gray block that is within the gray value range of the standard part of the material being tested is the gray block of the material being tested. The outline of the material being tested is drawn according to the position of the gray block of the material being tested, and the outline corresponding to the impact position is marked. During the impact process, if the offset angle of the marked contour line reaches... When determining that an impact will cause damage to the tested material, the ultimate stress is used. Impact contact area before change To achieve the ultimate impact force With real-time impact force By comparison, the difference in impact force was calculated. By inferring the difference in impact force from the corresponding difference in impact contact area, and by determining the maximum offset angle based on the proportional relationship between the offset angle and the contact area, the maximum offset angle can be obtained. .
[0022] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.
Claims
1. A device for testing the impact resistance of explosion-proof doors in mine ventilation shafts, comprising a testing platform (1), a drive platform (2) installed in the middle of the top surface of the testing platform (1), a placement platform (3) provided at the front end of the testing platform (1), a testing area provided between the two placement platforms (3), a scale (4) installed at the front end of the top surface of the drive platform (2), and a hammer block (5) rotatably connected to the front end of the scale (4), characterized in that: The top surface of the testing platform (1) is equipped with a protective component for the limiting hammer block (5); The controller of the detection device is equipped with a force calculation module and an impact early warning module. The force calculation module calculates the increment of gravitational potential energy based on inherent parameters such as hammer mass and pendulum length; it introduces a real-time energy loss coefficient, which comprehensively considers factors such as mechanical wear, lifting angle, material properties and component aging, and dynamically corrects it through a multi-factor product model; based on the momentum theorem and energy conservation, it calculates the impact force and impact stress. The impact warning module performs grayscale processing and contour extraction on the image data, and marks the contour line of the impact location; The system monitors the offset angle of the contour line in real time during the impact process and compares it with the preset limit offset angle. Combining the limit stress of similar materials in historical data, the system calculates the limit impact force and compares it with the current real-time impact force to obtain the impact force difference. If the offset angle is close to or reaches the maximum offset angle, the system will automatically issue an early warning.
2. The impact resistance testing device for explosion-proof doors in mine ventilation shafts according to claim 1, characterized in that: The data analysis steps for the force calculation module are as follows: M1: Lifting angle based on angle sensor data Calculate the increment of the hammer's gravitational potential energy. The collected angle data were then subjected to outlier detection and preprocessing to remove data that exceeded the mean ± 3 times the standard deviation, thus obtaining valid angle data. M2: Calculate the real-time energy loss coefficient based on factors such as mechanical wear, lifting angle deviation, material elastic modulus, and component aging. The individual factors are obtained through a product model. The value is substituted into the calculation of the impact force. Furthermore, combined with the impact contact area Calculate impact stress This enables dynamic correction and output of impact parameters.
3. The impact resistance testing device for explosion-proof doors in mine ventilation shafts according to claim 1, characterized in that: The data analysis steps for the force calculation module are as follows: N1: The camera captures images of the material under test, performs grayscale processing and contour extraction, marks the contour line at the impact position, and monitors its offset angle in real time during the impact process. N2: The ultimate stress of similar materials retrieved from the historical database. Based on the current impact contact area Calculate the ultimate impact force ; its real-time impact force and Compare and calculate the difference in impact force. If the detected contour line offset angle is close to or exceeds the preset maximum offset angle The system will automatically issue a warning and can, based on... The subsequent test parameters are dynamically adjusted in relation to the offset angle.
4. The impact resistance testing device for explosion-proof doors in mine ventilation shafts according to claim 1, characterized in that: The drive platform (2) is equipped with a positioning sensor (16) for detecting the number of swings of the hammer block (5) at the lower center of the front end. The hammer block (5) is fitted with a hook (9) adapted to the protective component. The hook (9) has an automatic limit area on one side and a manual limit area on the other side.
5. The impact resistance testing device for explosion-proof doors in mine ventilation shafts according to claim 1, characterized in that: The protective assembly includes a protective platform (6) installed on one side of the top surface of the drive platform (2). The protective platform (6) has a drive groove adapted to the automatic limit area and a reset hole adapted to the manual limit area on one side. The front end of the reset hole has a drive hole.
6. The impact resistance testing device for explosion-proof doors in mine ventilation shafts according to claim 5, characterized in that: An electric push cylinder (7) is installed in the drive slot. The output shaft of the electric push cylinder (7) is connected to a limit rod placed in the automatic limit area through a coupling. The outer side of the limit rod abuts against the inner side of the grab hook (9). A protective rod (8) is slidably connected in the reset hole.
7. The impact resistance testing device for explosion-proof doors in mine ventilation shafts according to claim 4, characterized in that: The protective rod (8) is fitted with a limiting block that fits the inner wall of the drive hole on the outside, and a first spring (10) is sleeved on the outside of the protective rod (8) and placed inside the drive hole; the first spring (10) is placed between the rear end of the limiting block and the drive hole, and the other end of the protective rod (8) is placed in the manual limiting area and abuts against the inner side of the grab hook (9).
8. The impact resistance testing device for explosion-proof doors in mine ventilation shafts according to claim 3, characterized in that: A positioning rod (11) is installed on the other side of the top surface of the protective platform (6). An installation block (14) is installed on the other end of the positioning rod (11). Positioning blocks are installed on both sides of the inner cavity of the installation block (14). Pressure sensors (15) are installed below the two positioning blocks. An impact block (12) is slidably connected to the inner side of the installation block (14). Sliding grooves adapted to the sliding limit of the positioning blocks are opened on both sides of the impact block (12). A second spring (13) is fixedly connected to the bottom surface of the sliding groove. A bonding plate that abuts against the pressure sensor (15) is fixedly connected to the other end of the second spring (13).