Mining flame-proof wiring terminal

Abstract

The invention discloses a mining flame-proof wiring terminal which comprises an insulating seat body, a conducting rod arranged in an axial through hole of the insulating seat body in a penetrating mode, and a pressing assembly. An independent explosion-proof joint surface is not formed between the conducting rod and the insulating seat body; the insulating seat body is directly fixed on the equipment separator through screws, so that only a joint surface between the outer cylindrical surface of the insulating seat body and the inner wall of the separator mounting hole is formed. The upper connecting part of the conducting rod can select a pre-embedded screw rod type or an insert nut type, and the lower connecting part can select a flat copper bar type or an internal thread cylinder type, so that various wiring schemes are combined. Through the integrated structure, the number of parts is greatly reduced, assembly procedures are greatly simplified, and the material cost and the manufacturing cost are greatly reduced; the intrinsic safety is improved from the source due to the design of a single explosion-proof joint surface; the overall structure is compact and the size is obviously reduced; the installation mode is simple and fast; the modular wiring form is high in adaptability, and a flexible, reliable and economical mining explosion-proof connection solution is provided for users.

Description

Technical Field

[0001] This invention relates to the field of explosion-proof electrical equipment technology, and specifically to an explosion-proof terminal block for mining applications. Background Technology

[0002] Explosion-proof electrical equipment, such as common explosion-proof control boxes and junction boxes, typically has its outer casing divided into two independent cavities by an internal metal partition: a main cavity and a wiring cavity. The main cavity houses components that may generate electrical sparks, such as switches and controllers; the wiring cavity is used to connect cables introduced from the outside. The partition between the main cavity and the wiring cavity has through holes, requiring dedicated explosion-proof terminals to allow cables to pass through the partition while maintaining its explosion-proof integrity. This terminal itself constitutes a critical explosion-proof component, and its structural reliability directly affects the explosion-proof safety performance of the entire equipment.

[0003] Currently, the mainstream explosion-proof terminal blocks for mining applications mainly adopt assembled or threaded explosion-proof structures. A typical assembled terminal block is usually assembled from multiple independent conductive copper blocks, insulating supports, connecting bolts, and a complex mechanical locking mechanism. The conductive path is formed through planar or threaded contact between the copper blocks, and these contact surfaces themselves constitute the explosion-proof mating surfaces that require precision machining. To meet the stringent requirements of explosion-proof standards (such as GB3836.2) regarding the length, gap, and surface roughness of the explosion-proof mating surfaces, this type of structure typically has the following inherent defects:

[0004] (1) Large size and low space utilization: In order to ensure mechanical strength and the size of multiple mating surfaces, traditional terminals are often tall, occupying a lot of valuable space inside the equipment, which is not conducive to the miniaturization and compact design of electrical equipment, and is especially inconvenient in the narrow installation environment of coal mines.

[0005] (2) Inconvenient installation and maintenance: During installation, it is often necessary to rotate and align the explosion-proof threads, or to install an additional anti-rotation device, which is complicated and inefficient. Multiple mechanical connection points are also at risk of increased contact resistance or even loosening due to vibration and thermal expansion and contraction, which affects the reliability of long-term operation.

[0006] (3) The efficiency of the conductive path needs to be improved: the current flows through multiple mechanical contact interfaces, and the contact resistance is relatively large, which may lead to a higher operating temperature rise, affecting the power transmission efficiency and equipment life.

[0007] (4) Numerous potential safety risks: Each individual explosion-proof joint surface (such as between the conductive rod and the insulating sleeve, between the insulating sleeve and the partition, and between each assembled copper block) is a potential failure point. The increase in the number of joint surfaces statistically increases the risk of explosion-proof performance degradation due to processing errors, improper installation, or long-term wear. Summary of the Invention

[0008] To address the shortcomings of existing technologies, this invention provides a mine-use explosion-proof terminal block that overcomes the deficiencies of existing technologies. It features a reasonable design and an integrated structure that greatly simplifies the number of parts and assembly processes, significantly reducing material and manufacturing costs. The single explosion-proof joint surface design enhances inherent safety from the source.

[0009] To achieve the above objectives, the present invention provides the following technical solution:

[0010] A mine-use explosion-proof terminal block is used for cables passing through a partition and connecting the main cavity and the wiring cavity in explosion-proof electrical equipment. It includes an insulating base, a conductive rod, and a clamping plate. The insulating base is fixedly mounted on the partition via an mounting assembly. An axial through-hole is formed in the middle of the insulating base, and the conductive rod passes through the axial through-hole. Both ends of the conductive rod extend out of the insulating base to form an upper connecting part and a lower connecting part. The joint between the conductive rod and the insulating base does not constitute an independent explosion-proof mating surface.

[0011] A screw is vertically fixed above the insulating base. The clamping plate is movably sleeved on the outer surface of the screw. An arc-shaped clamping groove is provided in the middle of the lower surface of the clamping plate. A nut is provided above the clamping plate, and the nut is threadedly engaged with the screw. The conductive rod is connected to the main cavity cable through the lower connecting part.

[0012] Preferably, the lower connecting part is constructed as a flat copper busbar connection structure or an internally threaded cylindrical connection structure;

[0013] The flat copper busbar connection structure includes a flat copper busbar, which is integrally disposed at the lower end of the conductive rod, and at least one mounting hole is provided in the middle of the flat copper busbar.

[0014] The internal threaded cylindrical connection structure includes a wiring cylinder, which is integrally and coaxially disposed at the lower end of the conductive rod, and the wiring cylinder has an internal threaded hole on its end face or side.

[0015] Preferably, the upper connecting part includes a connecting block, which is integrally fixed to the upper end of the conductive rod. The top surface of the connecting block is provided with a U-shaped crimping groove for crimping the cable core. The U-shaped crimping groove and the arc-shaped clamping groove are vertically corresponding to each other to clamp the cable in the wiring cavity between the U-shaped crimping groove and the arc-shaped clamping groove.

[0016] Preferably, an insert nut is fixedly installed inside the insulating base, the lower end of the screw is threadedly connected to the insert nut, and the axis of the insert nut is parallel to and does not coincide with the axis of the axial through hole.

[0017] Preferably, the lower end of the screw is integrally fixed with an embedded part, which is embedded inside the insulating base and injection molded into an integral structure with the insulating base.

[0018] Preferably, it further includes an auxiliary positioning structure, which includes a positioning baffle and a positioning pin. A positioning groove is horizontally opened inside the insulating base. The positioning baffle is installed in the positioning groove. The conductive rod passes through the central through hole of the positioning baffle and is clearance-fitted with it. The lower end of the positioning pin is fixedly installed on the bottom surface of the positioning groove. The upper end of the positioning pin passes through the through hole on the positioning baffle and is interference-fitted with it. A vertically penetrating positioning hole is opened in the middle of the upper connecting part. The upper end of the positioning pin extends into the positioning hole.

[0019] Preferably, the mounting assembly includes a flange and fasteners. The flange is formed on the outer periphery of the insulating base and has a plurality of circumferentially distributed mounting holes. The fasteners include screws and washers. The screws pass through the mounting holes to lock the flange of the insulating base onto the corresponding mounting surface of the partition.

[0020] Preferably, the outer cylindrical surface of the insulating base and the inner cylindrical surface of the mounting hole on the partition plate form a cylindrical explosion-proof joint surface.

[0021] Preferably, the conductive rod is made of copper or copper alloy, and the insulating base is made of thermosetting plastic by molding process, wherein the conductive rod is composite molded with the insulating base during the molding process.

[0022] This invention provides a mine-use explosion-proof terminal block with the following advantages: by simplifying the multiple explosion-proof mating surfaces present in traditional multi-component assembly structures to a single cylindrical mating surface formed between the outer cylindrical surface of the insulating base and the inner wall of the equipment partition mounting hole, the systemic risk of explosion-proof performance failure due to machining errors, assembly defects, or long-term wear of the mating surface is minimized, achieving a significant improvement in the intrinsic safety of the equipment.

[0023] By adopting a one-piece copper rod conductive rod structure, redundant components such as supporting copper blocks and transition connectors in traditional structures are eliminated. Furthermore, only one outer cylindrical surface requires precision machining for explosion-proof rating, eliminating the high-cost precision machining processes for all internal explosion-proof surfaces. The one-piece continuous conductive rod provides a seamless current path, completely eliminating the additional contact resistance caused by multiple mechanical contact interfaces. This results in stronger current-carrying capacity at the terminals, lower operating temperature rise, higher power transmission efficiency, and significantly improved long-term operational stability.

[0024] By designing the upper connecting part of the conductive rod as either a "pre-embedded screw type" or an "insert nut type," and the lower connecting part as either a "flat copper busbar type" or an "internal threaded cylindrical type," four standardized solutions can be combined. Users can flexibly choose according to site space, cable specifications, and wiring habits, ensuring strong compatibility. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in this invention or the prior art, the accompanying drawings used in the description of this invention or the prior art will be briefly introduced below.

[0026] Figure 1 A schematic diagram of the structure of this invention;

[0027] Figure 2 A schematic diagram of the cross-sectional structure of the present invention using a pre-embedded screw type + flat copper busbar type scheme;

[0028] Figure 3 A schematic diagram of the cross-sectional structure of the present invention using an insert nut type + flat copper busbar scheme;

[0029] Figure 4 A schematic diagram of the cross-sectional structure of the present invention using a pre-embedded screw type + internally threaded cylindrical type scheme;

[0030] Figure 5 A schematic diagram of the cross-sectional structure of the present invention using an insert nut type + internal thread cylindrical type scheme;

[0031] Figure 6 A schematic diagram of the auxiliary positioning structure in this invention;

[0032] Figure 7 A schematic diagram of the structure of Embodiment 7 of the present invention;

[0033] Explanation of the labels in the diagram:

[0034] 1. Insulating base; 2. Conductive rod; 3. Clamping plate; 4. Axial through hole; 5. Screw; 6. Arc-shaped clamping groove; 7. Nut; 8. Flat copper busbar; 9. Wiring cylinder; 10. Insert nut; 11. Embedded part; 12. Positioning baffle; 13. Positioning pin; 14. Positioning groove; 15. Positioning hole; 16. Screw; 17. Washer; 18. Connecting block; 19. U-shaped wire pressing groove; 20. Partition. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0036] Example 1, as Figures 1 to 7As shown, a mine-use explosion-proof terminal block is used for cables passing through a partition 20 to connect the main cavity and the wiring cavity in explosion-proof electrical equipment. It includes an insulating base 1, a conductive rod 2, and a clamping plate 3, all made of insulating material. The insulating base 1 is fixedly mounted on the partition 20 via a mounting assembly. The main body of the insulating base 1 mates with mounting holes on the partition 20 to form a critical explosion-proof joint surface. An axial through hole 4 is formed in the middle of the insulating base 1, and the conductive rod 2 passes through the axial through hole 4. Both ends of the conductive rod 2 extend out of the insulating base 1 to form an upper connection portion and a lower connection portion, respectively. The conductive rod 2 and the insulating base 1 are bonded together with a dense material, without any gaps for relative movement, and therefore do not constitute an independent explosion-proof joint surface.

[0037] A screw 5 is vertically fixed on the top of the insulating base 1. A clamping plate 3 is movably sleeved on the outer surface of the screw 5. An arc-shaped clamping groove 6 is provided in the middle of the lower surface of the clamping plate 3. A nut 7 is provided on the top of the clamping plate 3. The nut 7 is threadedly engaged with the screw 5. The conductive rod 2 is connected to the main cavity cable through the lower connecting part.

[0038] Working principle:

[0039] This invention abandons the traditional method of assembling multiple conductive parts (such as copper blocks and connecting pieces) through mechanical contact to form a current path. The conductive rod 2 is made of a single copper rod and runs through the entire terminal block from top to bottom. During installation, the entire terminal block is simply inserted into the mounting hole of the housing partition and fixed to achieve mechanical fixation and explosion-proof sealing. During wiring, the cable core introduced into the wiring cavity is placed on the upper connecting part of the conductive rod 2. By tightening the nut 7, the clamping plate 3 moves downward along the screw 5, and the arc-shaped clamping groove 6 on its lower surface firmly presses the cable core onto the wiring surface of the upper connecting part. Thus, the cable in the wiring cavity is fixed in the wiring cavity through the clamping action of the clamping plate 3 and the upper connecting part. In this embodiment, the clamping plate 3 and the nut 7 are also equipped with spring washers to provide anti-loosening protection and ensure that the clamping force does not decrease under vibration. The main cavity cable is fixed to the lower connecting part of the conductive rod 2 by bolts. During operation, current flows in from the cable on the wiring cavity side, passes through the upper connecting part and flows directly into the body of the conductive rod 2, then is directly conducted through the continuous, seamless metal body of the conductive rod 2 to the lower connecting part, and finally flows into the cable on the main cavity side. This continuous, integrated metal conductive path fundamentally eliminates the contact resistance caused by multiple mechanical contact interfaces, significantly reducing energy consumption and temperature rise during operation, and improving conductivity and long-term stability.

[0040] In this embodiment, the conductive rod 2 is molded together with the insulating base 1 into a robust whole through a molding process. The insulating base 1 (typically made of high-performance thermosetting plastics such as DMC) not only provides reliable electrical insulation, ensuring sufficient creepage distance and clearance, but also serves to mechanically fix and support the conductive rod 2. There is no relative movement between the two, and no precision-machined mating surfaces are required. Therefore, no separate explosion-proof mating surface is needed, simplifying the structure and eliminating potential leakage points.

[0041] Furthermore, the explosion-proof function between the entire terminal block and the explosion-proof equipment housing of this invention is solely provided by a precision-machined cylindrical explosion-proof mating surface formed between the outer cylindrical surface of the insulating base 1 and the inner cylindrical surface of the mounting hole on the partition plate 20. Thus, when an explosion occurs on the wiring cavity side, the high-temperature, high-pressure flame gas attempts to propagate to the main cavity through the terminal block. This single explosion-proof mating surface forces the flame through a narrow, elongated slit channel. During this process, the flame is sufficiently cooled by the metal wall, and the temperature drops below the minimum point required to ignite the explosive mixture in the main cavity, thereby successfully preventing the propagation of the explosion. By eliminating all internal, secondary explosion-proof mating surfaces, leakage paths that could lead to failure due to machining, installation, or wear are significantly reduced, significantly improving the overall reliability of the explosion-proof system.

[0042] In Example 2, as a further preferred embodiment of Example 1, the lower connecting part is constructed as a flat copper busbar connection structure or an internally threaded cylindrical connection structure.

[0043] Among them, such as Figures 2 to 3 As shown, the flat copper busbar connection structure includes a flat copper busbar 8, which is integrally installed at the lower end of the conductive rod 2. At least one mounting hole is provided in the center of the flat copper busbar 8. The cable on the main cavity side can be directly passed through the mounting hole on the flat copper busbar 8 and crimped for fixation using bolts, flat washers, spring washers, and nuts, achieving a low-impedance, highly reliable electrical connection. The flat copper busbar 8 has a large cross-sectional area and surface area, providing a low-resistance, high-current path for the connected main cavity cable. Its wide surface facilitates heat dissipation, effectively reducing temperature rise during high-current operation and improving long-term operational stability and safety, making it particularly suitable for main circuit connections of high-power equipment. Connection via bolts through the mounting hole ensures a tight fit and high-strength mechanical locking. This connection method has strong vibration and pull-out resistance, can withstand mechanical stresses that may occur during the operation of downhole equipment, ensures durable and reliable connection points, and eliminates the risk of poor contact or discharge due to loosening.

[0044] like Figures 4 to 5As shown, the internally threaded cylindrical connection structure includes a terminal cylinder 9, which is integrally and coaxially mounted at the lower end of the conductive rod 2. The terminal cylinder 9 has an internally threaded hole on its end face or side. When connecting the main cavity cable, simply screw the cable lug directly into this internally threaded hole and tighten it. This internally threaded cylindrical connection structure is more compact and particularly suitable for installations with limited radial space. When the internally threaded hole is located on the side, it provides the possibility of lateral access for the main cavity cable. This allows the cable to be introduced and directly fixed from different directions of the equipment housing, optimizing the internal wiring path, reducing cable bending, and improving wiring neatness and maintenance convenience. Furthermore, both the flat copper busbar 8 and the terminal cylinder 9 are integrally mounted with the conductive rod 2 body. This means that from the conductive rod 2 to the connection interface is a complete metallic continuum, completely eliminating the contact resistance, corrosion, loosening, and resulting localized overheating and potential difference present at the "conductive rod-connecting copper block" assembly interface in traditional structures. The current transmission path is seamless and efficient, with electrical performance significantly superior to any mechanical splicing method.

[0045] In embodiment three, as a further preferred embodiment one, the upper connecting part includes a connecting block 18, which is integrally fixed to the upper end of the conductive rod 2. The top surface of the connecting block 18 is provided with a U-shaped crimping groove 19 for crimping the cable core. The U-shaped crimping groove 19 corresponds vertically to the arc-shaped clamping groove 6 to clamp the cable in the wiring cavity between the U-shaped crimping groove 19 and the arc-shaped clamping groove 6. The connecting block 18 and the conductive rod 2 are integrally machined from the same copper material, achieving seamless metallic continuity from the crimping part to the conductive rod body. There is no additional impedance when current flows through this part, and the current carrying capacity depends entirely on the cross-sectional area of ​​the conductor itself, thereby significantly reducing the operating temperature rise, improving the power transmission efficiency and long-term stability, and is especially suitable for high current or continuous load conditions. The U-shaped crimping groove 19 provides a stable and fitting receiving surface for the cable core, increasing the effective contact area. The U-shaped clamping groove 6 above works in conjunction with the U-shaped clamping groove 19 to apply pressure, ensuring that the wire core is evenly and firmly wrapped within the hyperboloid clamping structure. This prevents sharp edges or corners from scratching, shearing, or causing excessive plastic deformation to the wire core, protecting the mechanical integrity of the conductor and thus avoiding the risk of localized overheating, strand breakage, or even fracture due to wire core damage. Furthermore, the U-shaped clamping groove 19 acts as a clearly defined physical guide groove, allowing for quick and accurate guidance and placement of the cable core into the correct position during installation, eliminating the need for visual alignment or repeated adjustments. This is particularly beneficial in wiring cavities with limited lighting or confined spaces, greatly simplifying the installation process and reducing errors.

[0046] Example 4, as Figure 3 and Figure 5As shown, in a further preferred embodiment, an insert nut 10 is fixedly installed inside the insulating base 1. The lower end of the screw 5 is threadedly connected to the insert nut 10, and the axis of the insert nut 10 is parallel to but does not coincide with the axis of the axial through hole 4. During the molding process of the insulating base 1, pre-embedding the insert nut 10, compared to pre-embedding a complete screw with a shaped head, generally simplifies the mold structure requirements and makes insert positioning easier. This reduces mold complexity and manufacturing costs, and improves the stability and yield of the molding process. The screw 5 and the insert nut 10 are threadedly connected, making the screw a component that can be independently disassembled. After long-term use, if the screw thread is damaged, corroded, or needs to be replaced with a different length, it is not necessary to replace the entire terminal block; simply unscrew the old screw and screw in the new one. This greatly improves product maintainability and reduces the total life-cycle cost, making it particularly suitable for equipment requiring regular maintenance under harsh operating conditions. Furthermore, by replacing standard screws of different diameters, strengths, or lengths, it can easily adapt to the clamping force requirements of cables of different diameters, or meet the depth requirements of special installation spaces, enabling a basic insulation base design to cover a wider range of application scenarios.

[0047] Example 5, as Figure 2 and Figure 4 As shown, in a further preferred embodiment, an embedded part 11 is integrally fixed at the lower end of the screw 5. The embedded part 11 is embedded inside the insulating base 1 and injection molded into an integral structure with the insulating base 1. The embedded part 11 (usually designed as a metal structure with knurling, holes, bends, or irregular shapes) is completely wrapped by molten insulating material, and after cooling and solidification, it forms an irreversible mechanical interlock and physical bond with the insulating base 1. This makes the screw 5 a permanent and non-removable rigid component of the insulating base 1. No matter how frequently the clamping nut 7 is tightened or how severe the vibration and impact of the equipment, there is absolutely no possibility of the screw 5 loosening, rotating, or being pulled out from the insulating base 1, thus eliminating the safety hazard of loss of clamping function due to failure of the fixing point. Furthermore, the embedded part 11 is completely covered by insulating material, which completely isolates the root of the screw 5 from the external environment. This effectively prevents the damp, corrosive gas, and coal dust environment in underground coal mines from directly corroding the installation root of the screw, fundamentally avoiding the problem of reduced strength or breakage caused by root corrosion, and significantly improving the product's environmental adaptability and service life under harsh working conditions.

[0048] It should also be noted that the two parallel structural schemes in Embodiment 4 and Embodiment 5 are not mutually exclusive, but can be flexibly selected according to specific application scenarios; the permanent pre-embedded structure of Embodiment 5 is preferred in scenarios with high reliability requirements such as underground coal mines, while the detachable screw design of Embodiment 4 is suitable for industrial sites that require frequent maintenance or have variable specifications.

[0049] Example 6, as Figure 6 As shown, as a further preferred embodiment, an auxiliary positioning structure is also included. This auxiliary positioning structure includes a positioning baffle 12 and a positioning pin 13. A positioning groove 14 is horizontally formed inside the insulating base 1. The positioning baffle 12 is installed within the positioning groove 14. The conductive rod 2 passes through the central through-hole of the positioning baffle 12 and is clearance-fitted with it. The lower end of the positioning pin 13 is fixedly installed on the bottom surface of the positioning groove 14, and the upper end of the positioning pin 13 passes through a through-hole on the positioning baffle 12 and is interference-fitted with it. A vertically penetrating positioning hole 15 is formed in the middle of the upper connecting part, and the upper end of the positioning pin 13 extends into the positioning hole 15. By extending the upper end of the positioning pin 13 into the positioning hole 15 of the upper connecting part of the conductive rod 2, a rigid, non-returning circumferential locking is formed. This completely eliminates any rotation of the conductive rod 2 when crimping cables, bearing torque, or experiencing vibration, ensuring that the direction of the upper connecting part always corresponds to the clamping plate 3, thereby guaranteeing the long-term stability of the electrical connection and the consistency of contact resistance. The precise and stable fixing of the conductive rod 2 directly ensures that the geometric accuracy and positional accuracy of the outer cylindrical surface of the insulating base 1 will not change due to the displacement of internal components. This allows the gap parameter of the unique and critical cylindrical explosion-proof joint surface between the insulating base and the partition to remain within the design requirements during long-term operation, fundamentally maintaining the reliability of the explosion-proof performance.

[0050] Example 7, a further preferred embodiment of Example 1, includes a mounting assembly comprising a flange and fasteners. The flange is formed on the outer periphery of the insulating base 1, and has multiple circumferentially distributed mounting holes. The fasteners include screws 16 and washers 17. The screws 16 pass through the mounting holes to lock the flange of the insulating base 1 onto the corresponding mounting surface of the partition 20. Traditional explosion-proof terminals are often installed by screwing them into the partition, which requires rotating the large and heavy terminal body and precisely aligning the threads, resulting in laborious and inefficient operation and potential damage to the explosion-proof threads. This invention uses multiple mounting holes on the flange to directly fasten the terminals from the front with screws. The terminals themselves do not need to be rotated; they only need to be inserted into the mounting holes of the partition and the screws tightened. This greatly simplifies the installation process, reduces the special requirements for operating space and tools, and is especially suitable for single-person, rapid operation in confined wiring cavities, increasing installation efficiency by more than 50%. The flange provides a clear and stable mounting reference surface. The circumferentially distributed mounting holes (usually four, symmetrically arranged) mate with the corresponding threaded holes on the partition plate, providing a clear positioning and guiding function to avoid directional errors during installation. Washer 17 provides reliable anti-loosening protection, ensuring a durable and stable connection even under vibration.

[0051] Example 8, as a further preferred embodiment of Example 1, forms a cylindrical explosion-proof mating surface between the outer cylindrical surface of the insulating base 1 and the inner cylindrical surface of the mounting hole on the partition 20. Traditional assembled terminals have multiple potential flame propagation paths (i.e., explosion-proof mating surfaces), such as between the conductive rod and the insulating sleeve, and between the insulating sleeve and the housing. However, the explosion-proof function of this invention is provided by only this one external cylindrical mating surface. Therefore, the single-matting-surface design minimizes the systemic risk of loss of explosion-proof function due to mating-surface failure, achieving a leap in explosion-proof safety. Explosion-proof mating surfaces require extremely high machining precision (surface roughness, flatness, gap size), which is one of the main cost components of explosion-proof parts. Traditional structures require precision machining of multiple internal and external threaded surfaces or flange surfaces. This invention only requires precision machining of one outer cylindrical surface of the insulating base 1 and one inner hole of the partition 20; other internal interfaces (such as the joint between the conductive rod and the insulating base) do not need to meet the explosion-proof surface requirements due to the integrated non-contact design. This directly eliminates several high-precision machining steps, reducing processing costs by more than 30%.

[0052] Example 9, as a further preferred embodiment of Example 1, shows that the conductive rod 2 is made of copper or a copper alloy, thus fully utilizing copper's top-ranking conductivity (second only to silver) and thermal conductivity among all engineering metals. This ensures that the integrated conductive path achieves the lowest resistance and temperature rise, meeting the requirements of high current and long-term continuous operation of mining equipment. The insulating base 1 is made of thermosetting plastic (especially DMC - bulk molding compound) through a molding process, ensuring that the insulating base 1 has sufficient creepage distance and electrical clearance to prevent high-voltage breakdown; and the thermosetting plastic is insoluble after curing, can withstand screw tightening force, cable tension and internal explosion pressure, and is not easily deformed, maintaining the geometric accuracy of the explosion-proof joint surface for a long time; and meets the requirements of explosion-proof standards for material thermal stability and flame retardant rating; and can resist the corrosion of underground humid, weakly acidic environments and grease. The conductive rod 2 is composite-molded with the insulating base 1 during the molding process. Inside the high-temperature, high-pressure mold, molten thermosetting plastic completely encapsulates the pre-placed conductive rod 2, filling all its fine structures. After cooling and solidification, the two form a tight mechanical interlock and physical bond at the microscopic level, becoming a single component that is inseparable from both material and function. This fundamentally eliminates the need for precise fitting and explosion-proof bonding between the conductive rod and the insulating sleeve in traditional structures.

[0053] This invention simplifies the multiple (usually two or more) explosion-proof joint surfaces present in traditional multi-component assembly structures to a single cylindrical joint surface formed between the outer cylindrical surface of the insulating base and the inner wall of the mounting hole of the equipment partition. This minimizes the systemic risk of explosion-proof performance failure due to machining errors, assembly defects, or long-term wear of the joint surface, achieving a significant leap in the intrinsic safety of the equipment. Furthermore, only one outer cylindrical surface needs to be precision-machined for explosion-proof rating, eliminating the high-cost precision machining processes for all internal explosion-proof surfaces. The use of an integrated copper rod conductive rod eliminates traditional supporting copper blocks, connectors, and other components. This integrated continuous conductive rod provides a seamless current path, completely eliminating the additional contact resistance caused by multiple mechanical contact interfaces. This results in stronger current-carrying capacity of the terminals, lower operating temperature rise, higher power transmission efficiency, and significantly improved long-term operational stability.

[0054] By designing the upper connection part as either a "pre-embedded screw type" or an "insert nut type," and the lower connection part as either a "flat copper busbar type" or an "internal threaded cylindrical type," four standardized solutions can be combined. Users can flexibly choose according to site space, cable specifications, and wiring habits, offering strong compatibility and wide adaptability.

[0055] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention 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 the present invention.

Claims

1. A mine-use explosion-proof terminal block, used for cables passing through a partition (20) in explosion-proof electrical equipment to connect the main cavity and the wiring cavity, characterized in that: The device includes an insulating base (1), a conductive rod (2), and a clamping plate (3). The insulating base (1) is fixedly mounted on the partition plate (20) by an installation assembly. The insulating base (1) has an axial through hole (4) that runs vertically through the middle. The conductive rod (2) passes through the axial through hole (4). The two ends of the conductive rod (2) extend out of the insulating base (1) to form an upper connecting part and a lower connecting part. The joint between the conductive rod (2) and the insulating base (1) does not constitute an independent explosion-proof joint surface. A screw (5) is vertically fixed above the insulating base (1). The clamping plate (3) is movably sleeved on the outer surface of the screw (5). An arc-shaped clamping groove (6) is provided in the middle of the lower surface of the clamping plate (3). A nut (7) is provided above the clamping plate (3). The nut (7) is threadedly engaged with the screw (5). The conductive rod (2) is connected to the main cavity cable through the lower connecting part.

2. The explosion-proof terminal block for mining as described in claim 1, characterized in that: The lower connecting part is constructed as a flat copper busbar connection structure or an internally threaded cylindrical connection structure. The flat copper busbar connection structure includes a flat copper busbar (8), which is integrally disposed at the lower end of the conductive rod (2), and at least one mounting hole is provided in the middle of the flat copper busbar (8). The internal threaded cylindrical connection structure includes a wiring cylinder (9), which is integrally and coaxially disposed at the lower end of the conductive rod (2). The end face or side face of the wiring cylinder (9) is provided with an internal threaded hole.

3. The explosion-proof terminal block for mining as described in claim 1, characterized in that: The upper connecting part includes a connecting block (18), which is integrally fixed to the upper end of the conductive rod (2). The top surface of the connecting block (18) is provided with a U-shaped crimping groove (19) for crimping the cable core. The U-shaped crimping groove (19) corresponds to the arc-shaped clamping groove (6) to clamp the cable in the wiring cavity between the U-shaped crimping groove (19) and the arc-shaped clamping groove (6).

4. The explosion-proof terminal block for mining as described in claim 1, characterized in that: An insert nut (10) is fixedly installed inside the insulating base (1). The lower end of the screw (5) is threadedly connected to the insert nut (10). The axis of the insert nut (10) is parallel to and does not coincide with the axis of the axial through hole (4).

5. A mine explosion-proof terminal block according to claim 1, characterized in that: The lower end of the screw (5) is integrally fixed with an embedded part (11), which is embedded in the interior of the insulating base (1) and injection molded into an integral structure with the insulating base (1).

6. A mine explosion-proof terminal block according to claim 1, characterized in that: It also includes an auxiliary positioning structure, which includes a positioning baffle (12) and a positioning pin (13). The insulating seat (1) has a horizontally opened positioning groove (14). The positioning baffle (12) is installed in the positioning groove (14). The conductive rod (2) passes through the central through hole of the positioning baffle (12) and is clearance-fitted with it. The lower end of the positioning pin (13) is fixedly installed on the bottom surface of the positioning groove (14). The upper end of the positioning pin (13) passes through the through hole on the positioning baffle (12) and is interference-fitted with it. The upper connecting part has a vertically through positioning hole (15) in the middle. The upper end of the positioning pin (13) extends into the positioning hole (15).

7. A mine explosion-proof terminal block according to claim 1, characterized in that: The mounting assembly includes a flange and fasteners. The flange is formed on the outer periphery of the insulating base (1) and has a plurality of mounting holes distributed circumferentially. The fasteners include screws (16) and washers (17). The screws (16) pass through the mounting holes to lock the flange of the insulating base (1) onto the corresponding mounting surface of the partition plate (20).

8. A mine explosion-proof terminal block according to claim 1, characterized in that: The cylindrical explosion-proof joint surface formed between the outer cylindrical surface of the insulating base (1) and the inner cylindrical surface of the mounting hole on the partition plate (20) is a cylindrical explosion-proof joint surface.

9. A mine explosion-proof terminal block according to claim 1, characterized in that: The conductive rod (2) is made of copper or copper alloy, and the insulating base (1) is made of thermosetting plastic by molding process. The conductive rod (2) is composite molded with the insulating base (1) during the molding process.

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