Modular explosion-proof and intrinsically safe electric control box for mine

Abstract

The utility model discloses a modularized explosion-proof and intrinsically safe electric cabinet for mine, including the box, the box front side is connected with the door through the quick -opening door structure, and the contactor body module and the isolation reversing module are installed in the box, the contactor body module includes the fixed frame, and the fixed frame front side is hinged with the hinge mounting plate, and the hinge mounting plate front fixed mounting has the power module, the relay module and the aviation plug connector, and the right side of hinge mounting plate and fixed frame are connected through the fixed part, and the fixed frame is fixedly installed with controller module, main circuit module and power module, and the door is fixedly embedded with the protector and operation module. The utility model overcomes the insufficient of prior art, and does not need to disassemble the whole module or to carry out the difficult operation in the online bundle cluster when overhauling. It greatly facilitates the intuitive inspection and troubleshooting to the component state. And realized the quick positioning and troubleshooting of the fault.

Description

Technical Field

[0001] This utility model relates to the technical field of mining electrical control equipment, specifically to a modular mining explosion-proof and intrinsically safe electrical control box. Background Technology

[0002] In the complex and harsh working environment of underground coal mines, explosion-proof and intrinsically safe electrical control boxes serve as the control core for various underground electromechanical equipment. Their reliability, safety, and maintainability directly affect the mine's production efficiency and personnel safety. These control boxes not only need to ensure they do not ignite or explode in environments containing explosive gases such as methane and coal dust, but also need to be compactly arranged within the limited space of roadways, facilitating daily maintenance and troubleshooting.

[0003] Currently, most traditional mining electrical control boxes widely used in the market are fixed structures designed for specific equipment. Their internal components (such as contactors, relays, and protectors) are typically mounted in a distributed and fixed manner on the mounting beams or plates of the main cavity of the box, and connected to the operating elements (buttons, indicator lights) on the door panel via complex cables. However, due to the fixed and compact layout of the internal components, the operating space is extremely narrow during maintenance or replacement. Technicians need to spend a significant amount of time performing tedious disassembly and wiring operations in this confined space, which is not only inefficient but also prone to introducing new points of failure during rewiring. Especially for core power and control components such as contactors and relays, the replacement process is complex once a fault occurs, severely impacting production continuity. Furthermore, switching between remote and local control modes usually requires power outages and opening the heavy box door to locate and operate the switch inside the box, which is neither safe nor convenient. Utility Model Content

[0004] To address the shortcomings of existing technologies, this utility model provides a modular, explosion-proof, and intrinsically safe electrical control box for mining applications. It overcomes the deficiencies of existing technologies, features a reasonable design, and eliminates the need for disassembling the entire module or performing difficult operations within the wiring harness during maintenance. This greatly facilitates intuitive inspection of component status and troubleshooting, and enables rapid fault location and diagnosis.

[0005] To achieve the above objectives, this utility model provides the following technical solution:

[0006] A modular explosion-proof and intrinsically safe electrical control box for mining includes a box body, a box door connected to the front side of the box body via a quick-opening door structure, and a contactor body module and an isolation switching module installed inside the box body.

[0007] The contactor body module includes a fixed frame. The front side of the fixed frame is hinged to the left side of the hinge mounting plate. The front of the hinge mounting plate is fixedly mounted with a power module, a relay module, and an aviation connector. The right side of the hinge mounting plate is connected to the fixed frame by a fastener. The fixed frame is fixedly mounted with a switching power supply, a transformer module, and a contactor module. The door of the enclosure is fixedly embedded with a protector and an operating module.

[0008] The input terminal of the isolation commutation module is connected to the external main circuit power supply, and the output terminal of the isolation commutation module is connected to the high-voltage side of the transformer module and the input terminal of the contactor module. The output terminal of the transformer module, after being connected to a low-voltage fuse, provides the required operating power to the switching power supply, power module, protector, operating module, and external load. The protector and operating module are signal-connected to the aviation connector. The control output terminal of the protector and operating module is electrically connected to the control coil of the relay module, and the contacts of the relay module are connected in series in the control coil circuit of the contactor module. The main contacts of the contactor module are connected to the isolation commutation module, and then connected to external loads such as motors through the wiring cavity. The input terminal of the aviation connector is electrically connected to the output terminal of the leakage protection module, the output terminal of the remote control receiver module, the I / O port of the protector, and the operating module. The output terminal of the aviation connector is connected to external devices such as sensors through the wiring cavity.

[0009] Preferably, the door also integrates a rotary switch for switching between near and far control. A remote control receiver module is fixedly installed in the inner cavity of the enclosure. After receiving a signal, the remote control receiver module modulates and demodulates it, and then feeds it back to external devices such as solenoid valves. An antenna for receiving wireless remote control signals is fixedly installed on the side wall of the enclosure. The antenna passes through a cable entry device on the wiring cavity and enters the enclosure to connect with the remote control receiver module. The remote control receiver module receives the wireless control signal from the external remote control through the antenna, decodes it, and transmits it to external devices such as solenoid valves. The rotary switch is electrically connected to the protector and the operation module to switch between near and far control operation modes.

[0010] Preferably, a wiring cavity is provided above the housing, and the low-voltage side power output interface of the transformer module is connected to the leakage protection module and then led to the wiring cavity through an aviation connector.

[0011] Preferably, a plurality of cable entry devices for connecting external cables are fixedly embedded in the side wall of the wiring cavity. Each cable entry device includes a connecting joint, a locking nut, and a clamping bolt. The connecting joint is fixedly embedded in the side wall of the wiring cavity. A rubber sealing ring for sealing the cable is provided inside the connecting joint. The clamping bolt is screwed into the internal thread of the connecting joint through its external thread. The locking nut is threaded onto the outer surface of the clamping bolt, and the end face of the locking nut abuts against the end face of the connecting joint. A rubber sheath is provided on the outside of the clamping bolt.

[0012] Preferably, the leakage current protection module includes a zero-sequence current transformer, which is mounted on the power output line. The secondary side of the zero-sequence current transformer is connected to the leakage current protection input terminal of the protector and the operation module. The control output port of the protector and the operation module is connected to the control terminal of the relay module used to control the corresponding branch.

[0013] Preferably, a wiring cover plate is fixedly installed on the upper end face of the wiring cavity. Multiple countersunk holes are evenly opened at the edge of the wiring cover plate. The countersunk holes correspond one-to-one with the mounting threaded holes on the side wall of the wiring cavity. A bolt is screwed into the mounting threaded hole through the countersunk hole to achieve a tight connection between the wiring cover plate and the wiring cavity.

[0014] Preferably, the fixing component includes a fixing ear plate and a locking bolt. One end of the fixing ear plate is fixedly installed on the side wall of the fixing frame, and the other end of the fixing ear plate is attached to the right back side of the hinge mounting plate and connected by the locking bolt.

[0015] This utility model provides a modular, explosion-proof, and intrinsically safe electrical control box for mining applications, offering the following advantages: By integrating the core electrical components within the control box onto a foldable contactor body module, maintenance can be performed without disassembling the entire module or performing difficult operations within the wiring harness. Maintenance personnel only need to open the box door and remove the locking bolts on the right side to fold out the entire hinge mounting plate, fully exposing the front of all components, greatly facilitating intuitive inspection of component status and troubleshooting. Each power output interface in the wiring compartment is equipped with an independent leakage protection module, significantly reducing the scope of fault impact, ensuring production continuity, and enabling rapid fault location and troubleshooting. Furthermore, the contactor body module connects to the wiring compartment above the control box via an aviation connector. To replace the contactor body module, simply unscrew the aviation connector and remove the fixing bolts on the base plate to remove the entire contactor body module for replacement. The cable entry device employs a double anti-loosening structure with clamping bolts and locking nuts, effectively resisting continuous underground vibration and preventing cables from falling off or generating sparks due to loose connections. The countersunk notch design of the wiring cover prevents water from accumulating in the mounting holes and allows it to drain quickly to the surrounding area. This not only effectively prevents corrosion of the bolts and cover, ensuring that the cover can be easily installed and removed throughout the entire life cycle of the equipment, but also ensures uniform clamping force due to the even distribution of the notch, which is beneficial for the stable control of the explosion-proof gap and improves the explosion-proof safety under long-term operation. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in this utility model or the prior art, the accompanying drawings used in the description of this utility model or the prior art will be briefly introduced below.

[0017] Figure 1 A schematic diagram of the structure of this utility model;

[0018] Figure 2 This utility model presents a schematic diagram of the hinge mounting plate after it has been opened.

[0019] Figure 3 A schematic diagram of the contactor body module after separation in this utility model;

[0020] Figure 4 A schematic diagram of the contactor body module in this utility model;

[0021] Figure 5 A schematic diagram of the installation structure of the cable introduction device in this utility model;

[0022] Figure 6 A schematic diagram of the cable introduction device in this utility model;

[0023] Explanation of the labels in the diagram:

[0024] 1. Enclosure; 2. Enclosure door; 3. Contactor body module; 4. Isolation reversing module; 5. Rotary switch; 6. Protector and operating module; 7. Wiring cavity; 8. Cable entry device; 9. Antenna; 10. Fixing ear plate; 11. Locking bolt; 12. Remote control receiver module; 13. Leakage protection module;

[0025] 31. Fixed frame; 32. Hinge; 33. Hinge mounting plate; 34. Power module; 35. Relay module; 36. Aviation connector; 37. Switching power supply; 38. Transformer module; 39. Contactor module;

[0026] 71. Wiring cover; 72. Countersunk notch;

[0027] 81. Connecting joint; 82. Locking nut; 83. Press bolt; 84. Rubber sleeve; 85. Rubber sealing ring. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings.

[0029] Example 1, as Figures 1-6 As shown, a modular explosion-proof and intrinsically safe electrical control box for mining includes a box body 1. The front side of the box body 1 is connected to a box door 2 through a quick-opening door structure. Inside the box body 1, a contactor body module 3 and an isolation switching module 4 are installed.

[0030] The contactor body module 3 includes a fixed frame 31. The front side of the fixed frame 31 is hinged to the left side of the hinge mounting plate 33 via a hinge 32. The front side is fixedly mounted with a remote control receiver module 12, a power supply module 34, a relay module 35, and an aviation connector 36. The right side of the hinge mounting plate 33 is connected to the fixed frame 31 via a fastener. The fixed frame 31 is fixedly mounted with a leakage protection module 13, a transformer module 38, and a contactor module 39. The door 2 is fixedly embedded with a protector and an operation module 6.

[0031] The input terminal of the isolation commutation module 4 is connected to the external power supply, and the output terminal of the isolation commutation module 4 is connected to the high-voltage side of the transformer module 38 and the input terminal of the contactor module 39. The output terminal of the transformer module 38, after being connected to a low-voltage fuse, provides the necessary operating power to the switching power supply 37, the power module 34, the protector and operation module 6, and the external load. The protector and operation module 6 is signal-connected to the aviation connector 36. The control output terminal of the protector and operation module 6 is electrically connected to the control coil of the relay module 35, and the contacts of the relay module 35 are connected in series in the control coil circuit of the contactor module 39. The main contacts of the contactor module 39 are connected to the isolation commutation module 4, and then connected to external loads such as motors through the wiring cavity 7. The input terminal of the aviation connector 36 is electrically connected to the output terminal of the leakage protection module 13, the output terminal of the remote control receiver module 12, the I / O port of the protector, and the operation module 6. The output terminal of the aviation connector 36 is connected to external devices such as sensors through the wiring cavity 7. An intrinsically safe power supply is also provided internally, and its output terminal supplies power to external intrinsically safe devices through the terminal block module.

[0032] Working principle:

[0033] The entire electrical control box is powered by an external coal mine power grid. The power supply first connects to the isolation switching module 4, which acts as the main switch, providing power isolation and switching functions. When this switch is closed, the power is split into two paths: one path goes to the contactor module 39 to provide power for high-power loads such as motors; the other path goes to the transformer module 38. The transformer module 38 converts and stabilizes the input AC power, outputting low-voltage AC power, which is then supplied to the switching power supply 37 and the intrinsically safe power supply, providing reliable operating power for the protector and operation module 6, the remote control receiver module 12, and external intrinsically safe sensors (such as methane sensors).

[0034] Operators can directly operate the buttons on the protector and operation module 6 of the enclosure door 2. The command signal is directly transmitted to the protector and operation module 6. After receiving the operation command, the protector performs logical operations and outputs a control signal to drive the relay module 35 to operate. Then, the relay module 35 controls the coil circuit of the contactor module 39 through the opening and closing of its contacts. When the coil of the contactor module 39 is energized, its main contacts close, connecting the power supply in the main circuit. At the same time, the control circuit is transmitted to the external load through the aviation connector 36.

[0035] When it is necessary to inspect or replace the electrical components on the contactor body module 3, maintenance personnel can simply open the cabinet door 2 and separate the right side of the hinge mounting plate 33 from the fixing frame 31. This allows the hinge mounting plate 33 to fold outwards along the left hinge 32, revealing the mounting plate containing most of the core components, such as the contactor module 39, relay module 35, and leakage protection module 13, to the operator, providing ample operating space. This significantly shortens the time for locating and replacing faulty components and for circuit maintenance, thereby greatly reducing the average repair time of the equipment and ensuring the high efficiency and continuity of coal mine production.

[0036] In Example 2, as a further preferred embodiment of Example 1, a rotary switch 5 for switching between near and remote control is integrated on the door 2. A remote control receiver module 12 is fixedly installed inside the housing 1. The remote control receiver module 12 is connected to the protector and operation module 6 via a CAN bus. An antenna 9 for receiving wireless remote control signals is fixedly installed on the side wall of the housing 1. The antenna 9 passes through the side wall of the housing 1 and connects to the remote control receiver module 12. The remote control receiver module 12 receives the wireless control signal from the external remote control through the antenna 9, decodes it, and transmits it to the protector via the CAN bus. The rotary switch 5 is electrically connected to the relay module 35 to switch between near and remote control operation modes. The operator can switch between "near control" and "remote control" modes using the rotary switch 5 on the door 2. When the rotary switch 5 is turned to the "near control" position, the control box only responds to the display on the door 2 and the commands issued by the operation module 6. At this time, the operator needs to operate directly next to the control box. When the rotary switch 5 is turned to the "remote control" position, the electrical control box only responds to the operation commands of the control buttons on the externally connected equipment. At this time, the operator can perform remote operation without being physically present at the control box. This solves the problems of production interruption, cumbersome and time-consuming operation caused by the traditional electrical control box requiring a power outage to open the cover when switching modes, as well as the safety risks of electric shock and damage to the explosion-proof structure caused by opening the cover while it is powered on. The operator can also use the matching intrinsically safe mining remote control to send a wireless signal. This signal is captured by the antenna 9 on the side wall of the box and transmitted to the remote control receiver module 12. After decoding the signal, the receiver sends the control commands to the protector and operation module 6 via a highly reliable CAN bus.

[0037] In Example 3, as a further preferred embodiment of Example 1, a wiring cavity 7 is provided on the top of the enclosure 1. The low-voltage side power output interface of the transformer module 38 is connected to the leakage current protection module 13, and then led to the wiring cavity 7 via an aviation connector 36. Therefore, when a leakage current fault occurs in an external load or its cable line connected to the electrical control box, only the leakage current protection module 13 corresponding to the faulty branch will trip, accurately cutting off the power supply to the faulty line. This avoids a chain reaction of power outages to the entire system due to the main switch tripping, minimizing the scope of the power outage and ensuring the normal operation of other non-faulty branch equipment. Furthermore, maintenance personnel can directly and quickly pinpoint the specific branch where the fault occurred based on which leakage current protection module 13 has tripped. This significantly improves fault diagnosis efficiency and shortens downtime.

[0038] Example 4, as Figures 5-6 As shown, as a further preferred embodiment of the third embodiment, a plurality of cable entry devices 8 for connecting external cables are fixedly embedded in the side wall of the wiring cavity 7. The cable entry device 8 includes a connecting joint 81, a locking nut 82, and a clamping bolt 83. The connecting joint 81 is fixedly embedded in the side wall of the wiring cavity 7. A rubber sealing ring 85 for sealing the cable is provided inside the connecting joint 81. The clamping bolt 83 is screwed into the internal thread of the connecting joint 81 through the external thread. The locking nut 82 is threadedly connected to the outer surface of the clamping bolt 83, and the end face of the locking nut 82 abuts against the end face of the connecting joint 81. A rubber sheath 84 is sleeved on the outside of the clamping bolt 83.

[0039] Therefore, during installation, the outer rubber-sheathed cable passes sequentially through the rubber sheath 84, the clamping bolt 83, the lock nut 82, and the internal rubber sealing ring 85. After pushing the cable into the connector 81, the clamping bolt 83 is tightened first. The clamping bolt 83 is screwed into the internal thread of the connector 81, squeezing the rubber sealing ring inward and causing radial deformation, thereby tightly gripping the outer sheath of the cable. This achieves a seal at the cable inlet, preventing gas flow between the inside and outside of the box, and initially securing the cable. After the clamping bolt 83 is tightened to the correct position, the lock nut 82 is screwed into the external thread of the clamping bolt 83 until its end face is tightly abutting against the end face of the connector 81. At this point, the lock nut 82 acts as a mechanical locking mechanism. Through the preload generated by the threaded pair, it restricts the relative movement between the clamping bolt 83 and the connector 81 in the axial and radial directions. This effectively prevents the clamping bolt from loosening due to equipment vibration or external pulling, thereby avoiding seal failure and cable detachment. Finally, the rubber sheath 84, which is pre-installed on the cable, is pushed forward and fitted over the entire exterior of the clamping bolt 83. The rubber sheath 84 effectively prevents coal dust, moisture, and water droplets from directly corroding the threaded connection of the clamping bolt 83, the lock nut 82, and the connecting joint 81, preventing them from jamming or failing due to corrosion, while further enhancing the overall sealing performance.

[0040] In Example 5, as a further preferred embodiment of Example 3, the leakage current protection module 13 includes a zero-sequence current transformer, a relay, and its coil. The zero-sequence current transformer is mounted on the power output line. The secondary side of the zero-sequence current transformer is connected to the leakage current protection input terminal of the protector and operation module 6. The control output port of the protector and operation module 6 is connected to the control terminal of the relay module 35 used to control the corresponding branch. The zero-sequence current transformer accurately senses the vector imbalance of the branch current and sends the weak leakage current signal (induced electromotive force) to the module for high-precision AD sampling and logic judgment. When leakage occurs, the current is unbalanced, and an induced electromotive force is generated on the secondary side of the transformer. As the leakage current increases, when the induced electromotive force on the secondary side reaches the relay's operating threshold, sufficient current will flow through the relay coil, causing the relay to operate. The normally closed contacts of the relay open, cutting off the circuit power supply and preventing electric shock accidents caused by leakage, thus providing protection and greatly reducing the probability of false operation, making the protection action more reliable.

[0041] Example 6, as Figure 5 As shown, in a further preferred embodiment, a wiring cover plate 71 is fixedly installed on the upper surface of the wiring cavity 7. Multiple countersunk notches 72 are evenly distributed along the edge of the wiring cover plate 71. Each countersunk notch 72 corresponds to a mounting threaded hole on the side wall of the wiring cavity 7. Bolts are screwed into the mounting threaded holes through the countersunk notches 72 to achieve a tight connection between the wiring cover plate 71 and the wiring cavity 7. By employing the countersunk notch 72 design, liquids falling onto the cover plate (such as condensate or downhole water) cannot accumulate in the countersunk holes of the mounting bolts. Instead, they can quickly drain away through the notches, effectively preventing bolt corrosion caused by water accumulation and reducing the risk of moisture rising inside the cavity due to poor sealing. Furthermore, the countersunk notches 72 are evenly distributed around the wiring cover plate 71, ensuring that the tightening force is evenly transmitted to the entire wiring cover plate 71 through the edges of the countersunk notches 72 when tightening the bolts, thus avoiding stress concentration.

[0042] In Embodiment Seven, as a further preferred embodiment of Embodiment One, the fasteners include a fixing ear plate 10 and a locking bolt 11. One end of the fixing ear plate 10 is fixedly mounted on the side wall of the fixing frame 31, and the other end of the fixing ear plate 10 is attached to the right back side of the hinge mounting plate 33 and connected by the locking bolt 11. Therefore, during normal operation of the equipment, the locking bolt 11 passes through the fixing ear plate 10 and tightens, rigidly connecting the right side of the hinge mounting plate 33 to the fixing frame 31 as a whole. During maintenance, only a few (usually one or two) locking bolts 11 need to be removed to release the right-side constraint, allowing the mounting plate to fold around the left hinge. Furthermore, the contactor body module is connected to the wiring cavity above the electrical control box via an aviation connector 36. If the contactor body module 3 needs to be replaced, simply unscrew the aviation connector and remove the fixing bolts on the body base plate to remove the entire contactor body module for replacement.

[0043] This invention integrates over 85% of the core electrical components (such as contactors, relays, and power modules) within the electrical control box onto a foldable contactor body module 3. During maintenance, there is no need to disassemble the entire module or perform difficult operations within the wiring harness. Maintenance personnel only need to open the box door and remove the locking bolt 11 on the right side to fold out the entire hinge mounting plate, fully exposing the front of all components. This greatly facilitates intuitive inspection of component status and troubleshooting. A rotary switch 5 is integrated into the box door 2, allowing operators to safely and quickly switch between "local control" and "remote control" modes from outside the box without power interruption or the use of tools to open the heavy explosion-proof door. Each power output interface in the wiring compartment 7 is equipped with an independent leakage protection module 13. When leakage occurs in any branch, the system can accurately locate and disconnect only the faulty branch, rather than causing a system-wide power outage as with traditional main protection. This significantly reduces the scope of fault impact, ensures production continuity, and enables rapid fault location and troubleshooting. The cable entry device 8 employs a double anti-loosening structure of clamping bolts 83 and locking nuts 82, effectively resisting continuous vibration underground and preventing the cable from falling off or generating sparks due to loose joints. The added rubber sheath 84 provides a reliable dust and moisture barrier for the metal threaded parts, preventing corrosion and ensuring long-term reliability of the explosion-proof performance and ease of maintenance. The countersunk notch 72 design of the wiring cover 71 prevents water from accumulating in the mounting hole, allowing it to drain quickly to the surrounding area. This not only effectively prevents corrosion of the bolts and cover, ensuring smooth installation and removal of the cover throughout the equipment's lifespan, but also ensures uniform clamping force due to the even distribution of the notch, facilitating stable control of the explosion-proof gap and improving explosion-proof safety during long-term operation.

[0044] The above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.

Claims

1. A modular explosion-proof and intrinsically safe electrical control box for mining, characterized in that: Includes a housing (1), the front side of which is connected to a door (2) via a quick-opening door structure, and the housing (1) is equipped with a contactor body module (3) and an isolation reversing module (4). The contactor body module (3) includes a fixed frame (31). The front side of the fixed frame (31) is hinged to the left side of the hinge mounting plate (33) via a hinge (32). The front of the hinge mounting plate (33) is fixedly mounted with a remote control receiver module (12), a power module (34), a relay module (35), and an aviation connector (36). The right side of the hinge mounting plate (33) is connected to the fixed frame (31) via a fastener. The fixed frame (31) is fixedly mounted with a leakage protection module (13), a transformer module (38), and a contactor module (39). The door (2) is fixedly embedded with a protector and an operation module (6). The input terminal of the isolation commutation module (4) is connected to the external power supply, and the output terminal of the isolation commutation module (4) is connected to the high-voltage side of the transformer module (38) and the input terminal of the contactor module (39); the output terminal of the transformer module (38) is connected to the low-voltage fuse to provide the required working power to the switching power supply (37), power module (34), protector and operation module (6) and external load; the protector and operation module (6) is connected to the aviation connector (36) for signal connection; the control output terminal of the protector and operation module (6) is connected to the relay module ( The control coil of the relay module (35) is electrically connected, and the contacts of the relay module (35) are connected in series in the control coil circuit of the contactor module (39); the main contacts of the contactor module (39) are connected to the isolation switching module (4), and then connected to the external load through the wiring cavity (7); the input end of the aviation connector (36) is electrically connected to the output end of the leakage protection module (13), the output end of the remote control receiver module (12), the I / O port of the protector, and the operation module (6); the output end of the aviation connector (36) is connected to the external device through the wiring cavity (7).

2. A modular explosion-proof and intrinsically safe electrical control box for mining as described in claim 1, characterized in that: The door (2) is also integrated with a rotary switch (5) for switching between near and far control. The inside of the box (1) is fixedly installed with a remote control receiver module (12). After receiving the signal, the remote control receiver module (12) modulates and demodulates it and feeds it back to the external device. The side wall of the box (1) is fixedly installed with an antenna (9) for receiving wireless remote control signals. The antenna (9) passes through the cable entry device (8) on the wiring cavity (7) and enters the box (1) to connect with the remote control receiver module (12). The remote control receiver module (12) receives the wireless control signal of the external remote control through the antenna (9), decodes it and transmits it to the external device. The rotary switch (5) is electrically connected to the protector and the operation module (6) and is used to switch between near control operation mode and remote control operation mode.

3. A modular explosion-proof and intrinsically safe electrical control box for mining as described in claim 1, characterized in that: A wiring cavity (7) is provided above the housing (1). After the low-voltage side power output interface of the transformer module (38) is connected to the leakage protection module (13), it is led to the wiring cavity (7) through the aviation connector (36).

4. A modular explosion-proof and intrinsically safe electrical control box for mining as described in claim 3, characterized in that: The side wall of the wiring cavity (7) is fixedly fitted with a plurality of cable entry devices (8) for connecting external cables. The cable entry device (8) includes a connecting joint (81), a locking nut (82) and a clamping bolt (83). The connecting joint (81) is fixedly fitted on the side wall of the wiring cavity (7). A rubber sealing ring (85) for sealing the cable is provided inside the connecting joint (81). The clamping bolt (83) is screwed into the internal thread of the connecting joint (81) through the external thread. The locking nut (82) is threaded to the outer surface of the clamping bolt (83), and the end face of the locking nut (82) abuts against the end face of the connecting joint (81). A rubber sheath (84) is provided on the outside of the clamping bolt (83).

5. A modular explosion-proof and intrinsically safe electrical control box for mining as described in claim 3, characterized in that: The leakage protection module (13) includes a zero-sequence current transformer, which is mounted on the power output line. The secondary side of the zero-sequence current transformer is connected to the leakage protection input terminal of the protector and operation module (6). The control output port of the protector and operation module (6) is connected to the control terminal of the relay module (35) used to control the corresponding branch.

6. A modular explosion-proof and intrinsically safe electrical control box for mining as described in claim 3, characterized in that: A wiring cover plate (71) is fixedly installed on the upper end face of the wiring cavity (7). Multiple countersunk holes (72) are evenly opened at the edge of the wiring cover plate (71). The countersunk holes (72) correspond one-to-one with the installation threaded holes on the side wall of the wiring cavity (7). The bolts are screwed into the installation threaded holes through the countersunk holes (72) to achieve a tight connection between the wiring cover plate (71) and the wiring cavity (7).

7. A modular explosion-proof and intrinsically safe electrical control box for mining as described in claim 1, characterized in that: The fastener includes a fixed ear plate (10) and a locking bolt (11). One end of the fixed ear plate (10) is fixedly installed on the side wall of the fixed frame (31), and the other end of the fixed ear plate (10) is attached to the right back side of the hinge mounting plate (33) and connected by the locking bolt (11).

Images