Device and method for testing the emergency shutdown of a belt conveyor

Abstract

The application provides a tape conveyor along-line emergency stop fault shaking test device and method, and belongs to the technical field of electrical detection equipment in underground coal mine. The device comprises a mine fire-retardant shell, a seven-core cable butt joint plug is arranged on the upper part of the shell, and a seven-way core wire plug pin is arranged in the shell. The common end of seven groups of single-knife two-way switching switches is connected with the plug pin, the upper position of the closing switch is connected with the upper row of core wire terminals, and the lower position of the opening switch is connected with the lower row of terminals. The self-resetting discharge button is connected with the grounding terminal and the upper row of terminals, and the synchronous grounding discharge is realized by pressing, and the automatic reset is realized by releasing. The low-voltage self-checking circuit module input end is connected with the lower row of terminals and the grounding terminal, the built-in mine safety low-voltage power supply, independent sampling resistor and signal acquisition chip, the fault of each core wire is indicated by the panel fault indicating lamp group, and the core wire is divided into sections. The shell bottom is provided with a double-way external surface pen clamping column. The application realizes the rapid switching of the cable, the safe synchronous discharge and the low-voltage self-checking diagnosis, and improves the safety and efficiency of the cable maintenance in the underground coal mine.

Description

Technical Field

[0001] This application belongs to the technical field of electrical testing equipment in coal mines, specifically relating to a device and method for detecting emergency stop faults along a belt conveyor. Background Technology

[0002] In underground coal mines, signal and control equipment extensively uses seven-core or other flame-retardant mining cables for connection. To ensure the reliability of power supply and control, it is necessary to regularly check the conductivity, insulation performance, and wiring correctness of the cable cores.

[0003] In existing technologies, maintenance personnel carry multimeters or megohmmeters, open the cable connection cavity, and manually measure the wires by touching the probes one by one. For seven-core cables, this requires at least seven rounds of switching probes and touching different cores, making the process cumbersome and time-consuming. Furthermore, due to factors such as dampness, insufficient lighting, and confined space underground, manual core-by-core testing is prone to errors in core numbering and omissions. In addition, after power is cut off in mining cables, residual charges often remain between cores and between cores and ground due to the long-distance distributed capacitance effect and induced voltage. Traditional discharge methods involve operators holding insulated wires and touching the grounding electrode one core at a time to discharge the charge. This is not only inefficient but also prone to leakage in individual cores if the operator is negligent. There is a risk of electric shock when maintenance personnel touch the cores, and the instantaneous discharge may also generate sparks, posing a potential safety threat to the gas-containing environment. Meanwhile, existing methods lack integrated low-voltage self-diagnostic functions, making it difficult to quickly determine the continuity, short circuit, and grounding faults of individual core wires and provide intuitive indications without disassembling cables or connecting large testing instruments. Once an abnormal signal occurs, multiple instruments are often required to troubleshoot the fault in sections, prolonging the power outage time and affecting the mine's safe production efficiency. Summary of the Invention

[0004] The purpose of this invention is to provide a device and method for detecting emergency stop faults along a belt conveyor in order to solve the problems in the prior art.

[0005] In a first aspect, embodiments of this application provide a device for detecting emergency stop faults along a belt conveyor line, the device comprising: Mining flame-retardant housing, seven-core cable connector, seven sets of single-pole bidirectional changeover switches, upper row core wire terminals, lower row core wire terminals, grounding terminals, self-reset discharge button, low-voltage self-test circuit module, dual-channel external tester clamping posts; The seven-core cable connector is fixed to the upper part of the housing and has seven core wire pins inside. Each set of single-pole bidirectional changeover switches includes a closing upper position and an opening lower position. The common terminal of the seven sets of single-pole bidirectional changeover switches is connected to the seven core wire pins one by one. The closing upper position is connected to the upper row of core wire terminals, and the opening lower position is connected to the lower row of core wire terminals. The grounding terminal is fixed to the left side of the housing and connected to the cable shield ground wire; The first end of the self-resetting discharge button is connected to the grounding terminal, and the second end is connected in parallel to all the upper row core wire terminals. The low-voltage self-test circuit module is integrated inside the mine flame-retardant housing and includes a mine safety low-voltage power supply, seven independent sampling resistors, a signal acquisition chip, a fault indicator light group, and a data output terminal. The input terminal of the low-voltage self-test circuit module is connected to the lower core wire terminal and the grounding terminal, respectively, and the output terminal is connected to the fault indicator light group of the housing panel. The dual-channel external probe holder is located at the bottom of the housing. The red probe holder is electrically isolated from the upper and lower core wire terminals, while the black probe holder is connected to the grounding terminal.

[0006] Furthermore, the mine safety low-voltage power supply of the low-voltage self-test circuit module is an intrinsically safe isolated DC power supply, and the power output circuit is connected in series with a total current limiting protection sampling resistor; The first end of the seven sampling resistors is connected to the lower row of core wire terminals respectively, and the second end is connected to the signal acquisition chip. The signal acquisition chip has a built-in threshold comparison program that presets the core wire to ground insulation threshold and the core wire mutual insulation threshold. The chip acquires the voltage divider signals of each sampling resistor in real time, calculates the core wire insulation status based on the voltage divider values, and synchronously outputs level signals to the partition fault indicator group.

[0007] Furthermore, the fault indicator light group includes: Seven core wires correspond to a red fault light, one green overall insulation qualified light, and one yellow grounding abnormal light. When the signal acquisition chip detects that the insulation resistance of a single core wire to ground is lower than the preset insulation threshold to ground, the corresponding red fault light of the core wire will remain on. When the insulation resistance between any two core wires is lower than the preset insulation threshold between core wires, the red fault lights of the two core wires will flash synchronously. When all core wire insulation parameters meet the standards, the green overall insulation qualification indicator light will remain on. When the grounding terminal is disconnected from the shielded ground wire, the yellow grounding fault indicator light will remain on.

[0008] Furthermore, the low-voltage self-test circuit module is equipped with a mode switching DIP switch, which has two positions: self-test mode and remote test mode. When the DIP switch is set to self-test mode, the electrical path between the dual-channel probe holder and the internal terminals is disconnected, while the low-voltage power supply, sampling resistor and signal acquisition chip are connected, and only the low-voltage circuit self-test function is activated. When the DIP switch is set to the megohmmeter test mode, the low-voltage power output circuit is cut off, and the dual-path tester clamping posts, core wire terminals, and grounding terminals are connected, allowing only an external megohmmeter to perform high-voltage insulation resistance testing.

[0009] Furthermore, each set of single-pole bidirectional switching switches is a mine-use explosion-proof toggle switch; When the single-pole bidirectional switching switch is switched to the closing position, all seven core wire pins are shorted to the same upper row wiring circuit. When the single-pole bidirectional switching switch is switched to the open position, the seven core wire pins are independently connected to their respective terminals in the lower row, and the core wires are completely electrically isolated.

[0010] Furthermore, the self-reset discharge button has a current-limiting discharge resistor connected in series inside.

[0011] Furthermore, the outer wall of the seven-core cable connector is wrapped with an elastic anti-slip sealing ring. When the plug is cleaned of coal sludge and conductive dust and then inserted into the emergency stop cable end, the sealing ring seals the gap between the plugs, preventing underground dust and water from seeping into the contact surface of the pins.

[0012] Furthermore, the dual-channel external probe holder is equipped with a resilient self-locking buckle, which is made of conductive copper.

[0013] Secondly, embodiments of this application also provide a method for detecting emergency stop faults along a belt conveyor line, the method comprising: Pre-processing process, low-voltage circuit self-test rough judgment process, high-voltage megohmmeter precise retest process, segmented fault location process, discharge reset and storage process: S1. Unplug all emergency stop cable plugs from both ends of the belt conveyor controller and the broadcast telephone, clean the coal sludge and conductive dust adhering to the plug cavity, and perform cable end pretreatment. S2. Connect the first end plug of the pre-processed emergency stop cable to the seven-core cable connector, leaving the second end of the cable suspended; switch the mode switching DIP switch to self-test mode, disconnect the power supply path of the megohmmeter probe holder, and connect the built-in intrinsically safe low-voltage self-test circuit; switch all seven sets of single-pole bidirectional switching switches to the open position, so that the seven core wires are independently isolated from each other; the built-in self-test circuit module synchronously collects the voltage divider signals between the seven core wires and ground, and between the core wires. The signal acquisition chip compares the preset insulation threshold to ground and the preset insulation threshold between the core wires, and drives the zone fault indicator group to output fault prompts; S3. Keep the emergency stop cable plugged in the same state, switch the mode switching DIP switch to the remote test mode, cut off the low voltage self-test power supply, connect the dual test probe clamping column, and perform high voltage insulation retest. S4. Based on the fault core wire information output by the self-test mode and the remote test mode, disconnect the emergency stop cable along the midpoint of the belt conveyor line, and repeat steps S1-S2 to test the first half and the second half of the cable respectively; if the segmented self-test still indicates a fault, repeat the test on the half-split cable segment again, gradually narrowing down the fault section until the precise fault point of the cable is located. S5. After all testing and fault location procedures are completed, switch all single-pole bidirectional switching switches to the closed position, press and hold the discharge button to release the residual charge in the line; restore the mode switching DIP switch to the middle power-off position, remove the megohmmeter probes, unplug the emergency stop cable plug, clean the coal slurry dust inside the seven-core connector, and complete the device reset and storage.

[0014] Furthermore, the specific steps of step S3 include: S31. Set all single-pole bidirectional changeover switches to the closed position and short-circuit all seven core wires simultaneously; clamp the red probe of the megohmmeter to any upper row core wire terminal and the black probe to the grounding terminal; crank the megohmmeter handle at a constant speed and read the insulation value. If the value is greater than or equal to the preset threshold, the overall insulation of the cable to ground is deemed qualified; if the value is less than the preset threshold, the overall insulation of the cable is deemed damaged and the entire cable needs to be replaced. After the coarse test is completed, press the discharge button to discharge. S32. All single-pole bidirectional changeover switches are switched to the open position, and each core wire is independently isolated; the red probe of the megohmmeter is fixedly clamped to the first lower row core wire terminal, and the black probe is clamped to the second to seventh lower row core wire terminals in turn for group testing. After the reading stabilizes, it is compared with the 30 megohm qualified threshold, and the pairing of the core wires with poor insulation is recorded; the red probe is rotated to the second, third, fourth, fifth, and sixth lower row core wire terminals in turn to complete the cross testing of all core wires; after the testing of each group of core wires is completed, the discharge button is pressed to release the residual charge, and the faulty core wire pairing information is output as the input for the segmented process.

[0015] As can be seen from the above technical solutions, the present invention has the following advantages: In the conveyor belt emergency stop fault detection device and method of the present invention, after connecting the cable once via a seven-core cable connector and seven sets of single-pole bidirectional switching switches, each core wire can be quickly selected to the upper or lower row of terminals simply by toggling the switch, thus improving detection efficiency. A self-resetting discharge button is used; when pressed, all upper row core wire terminals simultaneously discharge residual charge to ground via the grounding terminal, and automatically disconnects when released, avoiding the risk of electric shock and discharge sparks that may remain from individual core discharge, thus meeting the explosion-proof safety requirements of underground coal mines. The built-in low-voltage self-testing circuit module is connected to the core wires via the lower row of terminals. Driven by a mine-use safety low-voltage power supply, seven independent sampling resistors and a signal acquisition chip work together to automatically diagnose continuity, short circuit, and grounding faults in each core wire. The faulty core wire and fault type are visually reported through the panel's zoned fault indicator lights, allowing maintenance personnel to quickly locate the problem without disassembling the wiring cavity or using external instruments, thus shortening power outage time. The dual-channel external probe holder provides a safe and convenient interface for connecting multimeters and other instruments for precise retesting. The electrical isolation design of the red probe holder eliminates the risk of misconnection. The entire device uses a mining-grade flame-retardant housing, which is compact, robust, and durable, making it particularly suitable for harsh underground environments and ensuring the safety and efficiency of mine electrical maintenance. Attached Figure Description

[0016] To more clearly illustrate the technical solution of the present invention, the accompanying drawings used in the description will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the emergency stop fault detection device along the belt conveyor line of this application; Figure 2 This is a flowchart illustrating the method for detecting emergency stop faults along the belt conveyor line in this application. Detailed Implementation

[0018] Various embodiments of the invention will be described more fully in the following detailed description of the device and method for detecting emergency stops along a belt conveyor line. The invention may have various embodiments, and adjustments and modifications may be made therein. However, it should be understood that there is no intention to limit the various embodiments of the invention to the specific embodiments disclosed herein, but rather the invention should be understood to encompass all modifications, equivalents, and / or alternatives falling within the spirit and scope of the various embodiments of the invention.

[0019] To make the objectives, features, and advantages of this invention more apparent and understandable, specific embodiments and accompanying drawings will be used to clearly and completely describe the technical solutions protected by this invention. Obviously, the embodiments described below are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0020] Please see Figure 1 The diagram shows a device for detecting emergency stop faults along a belt conveyor line. The device includes: Mining flame-retardant housing, seven-core cable connector, seven sets of single-pole bidirectional changeover switches, upper row core wire terminals, lower row core wire terminals, grounding terminals, self-reset discharge button, low-voltage self-test circuit module, dual-channel external tester clamping posts; The seven-core cable connector is fixed to the upper part of the housing and has seven core wire pins inside. Each set of single-pole bidirectional changeover switches includes a closing upper position and an opening lower position. The common terminal of the seven sets of single-pole bidirectional changeover switches is connected to the seven core wire pins one by one. The closing upper position is connected to the upper row of core wire terminals, and the opening lower position is connected to the lower row of core wire terminals. The grounding terminal is fixed to the left side of the housing and connected to the cable shield ground wire; The first end of the self-resetting discharge button is connected to the grounding terminal, and the second end is connected in parallel to all the upper row core wire terminals. The low-voltage self-test circuit module is integrated inside the mine flame-retardant housing and includes a mine safety low-voltage power supply, seven independent sampling resistors, a signal acquisition chip, a fault indicator light group, and a data output terminal. The input terminal of the low-voltage self-test circuit module is connected to the lower core wire terminal and the grounding terminal, respectively, and the output terminal is connected to the fault indicator light group of the housing panel. The dual-channel external probe holder is located at the bottom of the housing. The red probe holder is electrically isolated from the upper and lower core wire terminals, while the black probe holder is connected to the grounding terminal.

[0021] As a refinement and extension of the specific implementation of the above embodiments, in order to fully illustrate the specific implementation process of this embodiment, another emergency stop fault detection device along the belt conveyor line is provided, the device comprising: Mining flame-retardant housing, seven-core cable connector, seven sets of single-pole bidirectional changeover switches, upper row core wire terminals, lower row core wire terminals, grounding terminals, self-reset discharge button, low-voltage self-test circuit module, dual-channel external tester clamping posts; The seven-core cable connector is fixed to the upper part of the housing and has seven core wire pins inside. Each set of single-pole bidirectional changeover switches includes a closing upper position and an opening lower position. The common terminal of the seven sets of single-pole bidirectional changeover switches is connected to the seven core wire pins one by one. The closing upper position is connected to the upper row of core wire terminals, and the opening lower position is connected to the lower row of core wire terminals. The grounding terminal is fixed to the left side of the housing and connected to the cable shield ground wire; The first end of the self-resetting discharge button is connected to the grounding terminal, and the second end is connected in parallel to all the upper row core wire terminals. The low-voltage self-test circuit module is integrated inside the mine flame-retardant housing and includes a mine safety low-voltage power supply, seven independent sampling resistors, a signal acquisition chip, a fault indicator light group, and a data output terminal. The input terminal of the low-voltage self-test circuit module is connected to the lower core wire terminal and the grounding terminal, respectively, and the output terminal is connected to the fault indicator light group of the housing panel. The dual-channel external probe holder is located at the bottom of the housing. The red probe holder is electrically isolated from the upper and lower core wire terminals, while the black probe holder is connected to the grounding terminal.

[0022] The 36V mining safety low-voltage power supply of the low-voltage self-test circuit module is an intrinsically safe isolated DC power supply. The power output circuit is connected in series with a total current limiting protection sampling resistor, and the resistance value of a single sampling resistor is uniformly 10kΩ. The first end of the seven sampling resistors is connected to the first to seventh lower row core wire terminals respectively, and the second end is connected to the analog acquisition channel of the signal acquisition chip. The signal acquisition chip has a built-in threshold comparison program that presets the core wire to ground insulation threshold and the core wire mutual insulation threshold. The chip acquires the voltage divider signals of each sampling resistor in real time, calculates the core wire insulation status based on the voltage divider values, and synchronously outputs level signals to the partition fault indicator group.

[0023] The fault indicator light group includes: Seven core wires correspond to a red fault light, one green overall insulation qualified light, and one yellow grounding abnormal light. When the signal acquisition chip detects that the insulation resistance of a single core wire to ground is lower than the preset insulation threshold of 20 megohms to ground, the corresponding red fault light of the core wire will remain on. When the insulation resistance between any two core wires is lower than the preset insulation threshold of 30 megohms, the red fault lights of the two core wires will flash synchronously. When all core wire insulation parameters meet the standards, the green overall insulation qualification indicator light will remain on. When the grounding terminal and the shielded ground wire are disconnected, the yellow grounding fault light will continue to illuminate, visually distinguishing between three types of faults: grounding fault, single-core leakage to ground, and short circuit between core wires.

[0024] The low-voltage self-test circuit module is equipped with a mode switching DIP switch, which has two positions: self-test mode and remote test mode. When the DIP switch is set to self-test mode, the electrical path between the dual-channel probe holder and the internal terminals is disconnected, and the 36V low-voltage power supply, sampling resistor and signal acquisition chip are connected, only the low-voltage circuit self-test function is activated. When the DIP switch is set to the high-voltage insulation test mode, the 36V low-voltage power supply output circuit is cut off, and the dual-path tester clamping posts, core wire terminals, and grounding terminals are connected. Only an external 500 megohm megohmmeter is allowed to perform high-voltage insulation tests. The two test modes are electrically interlocked to prevent the high-voltage megohmmeter from damaging the low-voltage self-test circuit components.

[0025] Each set of single-pole bidirectional switching switches is a mine-use explosion-proof toggle switch; When the single-pole bidirectional switching switch is switched to the closed position, all the first to seventh core wire pins are shorted to the same upper row wiring circuit, which meets the coarse test conditions for the overall cable insulation to ground. When the single-pole bidirectional switching switch is switched to the open position, the pins of the first to seventh core wires are independently connected to their respective terminals in the lower row, and the core wires are completely electrically isolated, which meets the requirements of cross-insulation detection of cores and self-testing of low-voltage circuits by core sampling. The mining flame-retardant shell panel is printed with "on / off" markings, the core wire numbers of the first to seventh core wires 1#-7#, grounding symbols, discharge text markings, and mode switching gear markings for rapid identification and operation in low-light environments underground.

[0026] The self-reset discharge button has a high-power current-limiting discharge resistor connected in series inside. The discharge resistor is adapted to the cable residual charge release requirements after a 500 megohm megohm high-voltage test.

[0027] Before switching lines after each test and low-voltage self-test, press the discharge button for 0.5s~1s to completely release the residual charge of the 7 core wires to ground, preventing operators from touching the metal terminals and causing electric shock accidents. The device housing has fixed mounting holes at the four corners. The housing is made of flame-retardant red steel plate and is stamped in one piece, providing protection against dust, coal slurry, and underground impact.

[0028] The outer wall of the seven-core cable connector is wrapped with an elastic anti-slip sealing ring. When the connector is cleaned of coal sludge and conductive dust and then inserted into the emergency stop cable end, the sealing ring seals the gap between the connectors, preventing underground dust and water from seeping into the contact surface of the pins and preventing conductive impurities from causing distortion of insulation test values.

[0029] The spacing of the seven pins inside the seven-core cable connector is perfectly matched with the original emergency stop cable connector of the belt conveyor, eliminating the need for secondary conversion and allowing direct insertion to adapt to a 2300m long-distance underground seven-core emergency stop transmission cable.

[0030] The dual-channel external probe clamping post is equipped with an elastic self-locking buckle. The buckle is made of conductive copper and can quickly clamp the red and black probe metal probes of the 500 megohmmeter. When operating alone, there is no need to hold the probes continuously for fixation. This frees the operator's hands to complete the switch range switching, discharge button pressing, and circuit segment plugging and unplugging operations, solving the shortcomings of traditional two-person cooperative megohmmeter testing, which consumes a lot of manpower and has insufficient operating space in the narrow plug cavity.

[0031] Please see Figure 2 The diagram shows a flowchart of a method for detecting emergency stop faults along a belt conveyor line. The method includes: S1. Unplug all emergency stop cable plugs from both ends of the belt conveyor controller and the broadcast telephone, clean the coal sludge and conductive dust adhering to the plug cavity, and perform cable end pretreatment. S2. Connect the first end plug of the pre-processed emergency stop cable to the seven-core cable connector, leaving the second end of the cable suspended; switch the mode switching DIP switch to self-test mode, disconnect the power supply path of the megohmmeter probe holder, and connect the built-in intrinsically safe low-voltage self-test circuit; switch all seven sets of single-pole bidirectional switching switches to the open position, so that the seven core wires are independently isolated from each other; the built-in self-test circuit module synchronously collects the voltage divider signals between the seven core wires and ground, and between the core wires. The signal acquisition chip compares the preset insulation threshold to ground and the preset insulation threshold between the core wires, and drives the zone fault indicator group to output fault prompts; S3. Keep the emergency stop cable plugged in the same state, switch the mode switching DIP switch to the remote test mode, cut off the low voltage self-test power supply, connect the dual test probe clamping column, and perform high voltage insulation retest. S4. Based on the fault core wire information output by the self-test mode and the remote test mode, disconnect the emergency stop cable along the midpoint of the belt conveyor line, and repeat steps S1-S2 to test the first half and the second half of the cable respectively; if the segment self-test still indicates a fault, repeat the test on the half-split cable segment again, gradually narrowing down the fault section until the precise fault point of the cable is located. S5. After all testing and fault location procedures are completed, switch all single-pole bidirectional switching switches to the closed position, press and hold the discharge button to release the residual charge in the line; restore the mode switching DIP switch to the middle power-off position, remove the megohmmeter probes, unplug the emergency stop cable plug, clean the coal slurry dust inside the seven-core connector, and complete the device reset and storage.

[0032] As a refinement and extension of the specific implementation of the above embodiments, in order to fully illustrate the specific implementation process in this embodiment, another method for detecting emergency stop faults along the belt conveyor is provided. The method includes a pre-processing step, a low-voltage circuit self-test coarse judgment step, a high-voltage megohmmeter precise re-test step, a segmented fault location step, and a discharge, reset, and storage step. S1. Unplug all the emergency stop cable plugs at both ends of the belt conveyor controller and the broadcast telephone. Use a dry insulating brush and a dust-free wiping cloth to clean the coal sludge and conductive dust adhering to the plug cavity. Let it stand for 30 seconds to ensure that the pins are completely dry and free of moisture. Perform cable end pretreatment. S2. Connect the first end plug of the pre-processed emergency stop cable to the seven-core cable connector, leaving the second end of the cable suspended. Switch the mode switching DIP switch to self-test mode, disconnect the power supply path of the megohmmeter probe holder, and connect the built-in 36V intrinsically safe low-voltage self-test circuit. Move all seven sets of single-pole bidirectional switching switches to the open position, isolating the seven core wires independently. The built-in self-test circuit module synchronously collects the voltage divider signals between the seven core wires and ground, and between the core wires. The signal acquisition chip compares the preset 20 megohms insulation threshold to ground and the preset 30 megohms insulation threshold between the core wires, driving the zone fault indicator group to output fault prompts. If the green qualified light is constantly on, it is determined that there is no obvious insulation damage to the entire cable, and it directly enters the high-voltage megohmmeter sampling inspection process. If the red fault light and the yellow grounding light are on, record the fault core wire number and fault type, and output coarse fault information as input for the segmentation positioning process. After all self-tests are completed, press the discharge button to release the stored charge on the core wires. S3. Keep the emergency stop cable plugged in the same state, switch the mode switching DIP switch to the remote test mode, cut off the 36V low-voltage self-test power supply, turn on the dual-circuit tester clamping column, and perform high-voltage insulation retest. The specific steps of step S3 include: S31. Set all single-pole bidirectional changeover switches to the closed position and short-circuit all seven core wires simultaneously; clamp the red probe of the 500 megohmmeter to any upper row core wire terminal and the black probe to the grounding terminal; crank the crank handle of the meter clockwise at a constant speed of 120 r / min, and read the insulation value after stabilizing for 10 seconds. If the value is greater than or equal to the preset threshold, the overall insulation of the cable to ground is deemed qualified; if the value is less than the preset threshold, the overall insulation of the cable is deemed damaged and the entire cable needs to be replaced. After the coarse test is completed, press the discharge button to discharge. S32. All single-pole bidirectional changeover switches are switched to the open position, and each core wire is independently isolated; the red probe of the megohmmeter is fixedly clamped to the first lower row core wire terminal, and the black probe is clamped to the second to seventh lower row core wire terminals in turn for group testing. After the reading stabilizes, it is compared with the 30 megohm qualified threshold, and the pairing of the core wires with poor insulation is recorded; the red probe is rotated to the second, third, fourth, fifth, and sixth lower row core wire terminals in turn to complete the cross testing of all core wires; after the testing of each group of core wires is completed, the discharge button is pressed to release the residual charge, and the faulty core wire pairing information is output as the input for the segmented process.

[0033] S4. Based on the fault core wire information output by the self-test mode and the remote test mode, disconnect the emergency stop cable at the midpoint of the 2300m belt conveyor line, and repeat steps S1-S2 to test the first half and the second half of the cable respectively; if the segment self-test still indicates a fault, repeat the test on the half-split cable segment again, gradually narrowing down the fault section until the precise fault point of the cable is located. S5. After all testing and fault location procedures are completed, switch all single-pole bidirectional switching switches to the closed position, press and hold the discharge button for 3 seconds to release the residual charge in the line; restore the mode switching DIP switch to the middle power-off position, remove the megohmmeter probes, unplug the emergency stop cable plug, clean the coal slurry dust inside the seven-core connector plug, and complete the device reset and storage.

[0034] It should be noted that the low-voltage circuit self-test coarse judgment process in step S2 can be performed independently without the need for an external 500 megohmmeter. The device's built-in 36V intrinsically safe self-test circuit can quickly screen for insulation faults in the entire cable, with a single self-test taking no more than 3 minutes. This can be used for rapid pre-shift inspections of the equipment. The high-voltage megohmmeter precise retest process in step S3 is only initiated when a fault is detected during the low-voltage self-test or when the equipment is shut down for major maintenance. The high-voltage megohmmeter test data serves as the final basis for fault determination. The entire testing process from steps S1 to S4 can be completed independently by a single person. Compared with the traditional two-person handheld megohmmeter core-by-core testing scheme, the total time for fault diagnosis and handling is reduced by more than 80%. The two testing modes are electrically interlocked. During the high-voltage megohmmeter test, the low-voltage self-test circuit is completely de-energized and isolated to avoid the safety hazard of explosion failure caused by high voltage breakdown of low-voltage sampling components.

[0035] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0036] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A device for detecting emergency stop faults along the conveyor belt, characterized in that, The device includes: Mining flame-retardant housing, seven-core cable connector, seven sets of single-pole bidirectional changeover switches, upper row core wire terminals, lower row core wire terminals, grounding terminals, self-reset discharge button, low-voltage self-test circuit module, dual-channel external tester clamping posts; The seven-core cable connector is fixed to the upper part of the housing and has seven core wire pins inside. Each set of single-pole bidirectional changeover switches includes a closing upper position and an opening lower position. The common terminal of the seven sets of single-pole bidirectional changeover switches is connected to the seven core wire pins one by one. The closing upper position is connected to the upper row of core wire terminals, and the opening lower position is connected to the lower row of core wire terminals. The grounding terminal is fixed to the left side of the housing and connected to the cable shield ground wire; The first end of the self-resetting discharge button is connected to the grounding terminal, and the second end is connected in parallel to all the upper row core wire terminals. The low-voltage self-test circuit module is integrated inside the mine flame-retardant housing and includes a mine safety low-voltage power supply, seven independent sampling resistors, a signal acquisition chip, a fault indicator light group, and a data output terminal. The input terminal of the low-voltage self-test circuit module is connected to the lower core wire terminal and the grounding terminal, respectively, and the output terminal is connected to the fault indicator light group of the housing panel. The dual-channel external probe holder is located at the bottom of the housing. The red probe holder is electrically isolated from the upper and lower core wire terminals, while the black probe holder is connected to the grounding terminal.

2. The conveyor belt emergency stop fault detection device according to claim 1, characterized in that, The mining safety low-voltage power supply of the low-voltage self-test circuit module is an intrinsically safe isolated DC power supply, and the power output circuit is connected in series with a total current limiting protection sampling resistor. The first end of the seven sampling resistors is connected to the lower row of core wire terminals respectively, and the second end is connected to the signal acquisition chip. The signal acquisition chip has a built-in threshold comparison program that presets the core wire to ground insulation threshold and the core wire mutual insulation threshold. The chip acquires the voltage divider signals of each sampling resistor in real time, calculates the core wire insulation status based on the voltage divider values, and synchronously outputs level signals to the partition fault indicator group.

3. The conveyor belt emergency stop fault detection device according to claim 2, characterized in that, The fault indicator light group includes: Seven core wires correspond to a red fault light, one green overall insulation qualified light, and one yellow grounding abnormal light. When the signal acquisition chip detects that the insulation resistance of a single core wire to ground is lower than the preset insulation threshold to ground, the corresponding red fault light of the core wire will remain on. When the insulation resistance between any two core wires is lower than the preset insulation threshold between core wires, the red fault lights of the two core wires will flash synchronously. When all core wire insulation parameters meet the standards, the green overall insulation qualification indicator light will remain on. When the grounding terminal is disconnected from the shielded ground wire, the yellow grounding fault indicator light will remain on.

4. The conveyor belt emergency stop fault detection device according to claim 1, characterized in that, The low-voltage self-test circuit module is equipped with a mode switching DIP switch, which has two positions: self-test mode and remote test mode. When the DIP switch is set to self-test mode, the electrical path between the dual-channel probe holder and the internal terminals is disconnected, while the low-voltage power supply, sampling resistor and signal acquisition chip are connected, and only the low-voltage circuit self-test function is activated. When the DIP switch is set to the insulation resistance test mode, the low-voltage power output circuit is cut off, and the dual-path tester clamping posts, core wire terminals, and grounding terminals are connected, allowing only an external megohmmeter to perform high-voltage insulation resistance tests.

5. The emergency stop fault detection device along the belt conveyor line according to claim 1, characterized in that, Each set of single-pole bidirectional switching switches is a mine-use explosion-proof toggle switch; When the single-pole bidirectional switching switch is switched to the closing position, all seven core wire pins are shorted to the same upper row wiring circuit. When the single-pole bidirectional switching switch is switched to the open position, the seven core wire pins are independently connected to their respective terminals in the lower row, and the core wires are completely electrically isolated.

6. The conveyor belt emergency stop fault detection device according to claim 1, characterized in that, The self-reset discharge button has a current-limiting discharge resistor connected in series inside.

7. The conveyor belt emergency stop fault detection device according to claim 1, characterized in that, The outer wall of the seven-core cable connector is wrapped with an elastic anti-slip sealing ring. When the connector is cleaned of coal sludge and conductive dust and then inserted into the emergency stop cable end, the sealing ring seals the gap between the connectors, preventing underground dust and water from seeping into the contact surface of the pins.

8. The conveyor belt emergency stop fault detection device according to claim 1, characterized in that, The dual-channel external probe holder is equipped with a flexible self-locking buckle, which is made of conductive copper.

9. A method for detecting emergency stop faults along a belt conveyor line, characterized in that, The method is based on the conveyor belt emergency stop fault detection device according to any one of claims 1 to 8. The method includes a pre-processing step, a low-voltage circuit self-test coarse judgment step, a high-voltage megohmmeter precise re-test step, a segmented fault location step, and a discharge reset and storage step. S1. Unplug all emergency stop cable plugs from both ends of the belt conveyor controller and the broadcast telephone, clean the coal sludge and conductive dust adhering to the plug cavity, and perform cable end pretreatment. S2. Connect the first end plug of the pre-processed emergency stop cable to the seven-core cable connector, leaving the second end of the cable suspended; switch the mode switching DIP switch to the self-test mode, disconnect the power supply path of the megohmmeter probe clamp column, and connect the built-in intrinsically safe low-voltage self-test circuit; switch all seven sets of single-pole bidirectional switching switches to the open position, so that the seven core wires are independently isolated from each other. The built-in self-test circuit module synchronously collects the voltage divider signals between the seven core wires and ground, and between the core wires. The signal acquisition chip compares the preset insulation threshold to ground and the preset insulation threshold between the core wires, and drives the zoned fault indicator group to output fault prompts. S3. Keep the emergency stop cable plugged in the same state, switch the mode switching DIP switch to the remote test mode, cut off the low voltage self-test power supply, connect the dual test probe clamping column, and perform high voltage insulation retest. S4. Based on the fault core wire information output by the self-test mode and the remote test mode, disconnect the emergency stop cable along the midpoint of the belt conveyor line, and repeat steps S1-S2 to test the first half and the second half of the cable respectively; if the segmented self-test still indicates a fault, repeat the test on the half-split cable segment again, gradually narrowing down the fault section until the precise fault point of the cable is located. S5. After all testing and fault location procedures are completed, switch all single-pole bidirectional switching switches to the closed position, press and hold the discharge button to release the residual charge in the line; restore the mode switching DIP switch to the middle power-off position, remove the megohmmeter probes, unplug the emergency stop cable plug, clean the coal slurry dust inside the seven-core connector, and complete the device reset and storage.

10. The method for detecting emergency stop faults along the belt conveyor line according to claim 9, characterized in that, The specific steps of step S3 include: S31. Set all single-pole bidirectional changeover switches to the closed position and short-circuit all seven core wires simultaneously; clamp the red probe of the megohmmeter to any upper row core wire terminal and the black probe to the grounding terminal; crank the megohmmeter handle at a constant speed and read the insulation value. If the value is greater than or equal to the preset threshold, the overall insulation of the cable to ground is deemed qualified; if the value is less than the preset threshold, the overall insulation of the cable is deemed damaged and the entire cable needs to be replaced. After the coarse test is completed, press the discharge button to discharge. S32. All single-pole bidirectional changeover switches are switched to the open position, and each core wire is independently isolated; the red probe of the megohmmeter is fixedly clamped to the first lower row core wire terminal, and the black probe is clamped to the second to seventh lower row core wire terminals in turn for group testing. After the reading stabilizes, it is compared with the 30 megohm qualified threshold, and the pairing of the core wires with poor insulation is recorded; the red probe is rotated to the second, third, fourth, fifth, and sixth lower row core wire terminals in turn to complete the cross testing of all core wires; after the testing of each group of core wires is completed, the discharge button is pressed to release the residual charge, and the faulty core wire pairing information is output as the input for the segmented process.

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