A three-phase electricity meter terminal block and a three-phase electricity meter

Abstract

This invention relates to the field of electricity meter technology, and more particularly to an optimized design of the terminal block structure for a three-phase electricity meter and a three-phase electricity meter. The invention is achieved through the following technical solution: a three-phase electricity meter terminal block, comprising a terminal block module mounted on a lower housing. The terminal block module includes: a female connector, multiple terminals mounted within the female connector, and a terminal block cover disposed on the female connector. The terminal block cover includes a main body covering the female connector and a limiting part extending from one end of the main body towards the female connector. This structure eliminates the need for positioning notches on the manganese-copper shunt body, achieving precise positioning of the shunt within the terminal block. This avoids the risks of localized current concentration and thermal stress caused by structural slotting, and significantly improves the accuracy and assembly efficiency of the shunt installation.

Description

Technical Field

[0001] This invention relates to the field of electricity meter technology, and in particular to the optimized design of the terminal block structure of a three-phase electricity meter and a three-phase electricity meter. Background Technology

[0002] Three-phase meters are metering devices used to measure the electrical energy consumption in three-phase AC circuits, and are widely used in industrial, commercial, and high-power applications. Common current sampling techniques include current transformer sampling and shunt sampling. Among these, shunt sampling is widely used in small-to-medium power direct-flow three-phase meters due to its advantages such as low cost, wide frequency response, and no magnetic saturation.

[0003] To achieve high-precision current measurement, direct-through three-phase meters typically integrate a manganese-copper shunt in the main current path. This shunt needs to be embedded inside the meter's terminals and reliably connected to the internal PCB circuit board or signal acquisition circuitry via soldering or crimping to output a micro-voltage signal proportional to the current. The accuracy of its installation position is crucial, directly affecting the symmetry of the current path, the stability of the sampling voltage, and the overall conductivity. If the position is off, it can easily lead to uneven contact resistance, unbalanced current distribution, and consequently, localized overheating, measurement errors, and even safety hazards.

[0004] Currently, the installation and positioning of manganese-copper shunts mainly relies on manual alignment, where operators visually adjust the position during assembly and then fix it. However, manual alignment is inefficient, inconsistent, and prone to human error, making it difficult to meet the needs of automated production. To address these issues, existing technologies often create positioning notches on the manganese-copper shunt body, which engage with protrusions in the terminals to achieve rapid and precise positioning and fixing. However, this slotted structure on the conductive body significantly reduces the conductor area of ​​critical sections, creating a current bottleneck. This leads to excessively high local current density, increasing loop resistance and Joule heat loss, and potentially causing excessive local temperature rise, thermal stress concentration, or material fatigue, ultimately affecting the reliability and safety of the meter under long-term operation. Summary of the Invention

[0005] In view of the above-mentioned defects in the prior art, the present invention provides a three-phase meter terminal block and a three-phase meter. Compared with the prior art, this structure can achieve precise positioning of the manganese copper shunt in the terminal block without opening a positioning notch on the body of the shunt. This avoids the risk of local current concentration and thermal stress caused by structural slotting, and significantly improves the accuracy and assembly efficiency of shunt installation. It also effectively ensures the stability of the sampling signal and the reliability of the main current circuit, thereby comprehensively improving the measurement accuracy and long-term operational safety of the meter.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A three-phase electricity meter terminal block includes a terminal block module mounted on a lower housing, the terminal block module comprising: A female connector, multiple terminals installed in the female connector, and a terminal cover disposed on the female connector; Each of the terminal blocks is provided with a manganese copper shunt. The lower end of the terminal block has multiple wiring holes for the manganese copper shunt to pass through, and the upper end has mounting holes for the manganese copper shunt to exit through. The terminal block cover includes a main body covering the terminal block and a limiting part extending from one end of the main body toward the terminal block. The inner side of the limiting part abuts against the end of the manganese copper shunt to limit the axial insertion depth of the manganese copper shunt.

[0007] This application provides a three-phase electricity meter terminal block, which mainly includes a terminal block module installed on the lower housing of the meter, used to realize the functions of external wire connection, current sampling, and internal circuit connection. The terminal block module consists of a female connector, multiple terminals, and a terminal block cover. The female connector is fixedly installed on the lower housing, and the multiple terminals are arranged inside the female connector according to the phase sequence and circuit layout requirements of three-phase electricity. The lower end of the female connector has multiple wiring holes, each corresponding to a terminal, through which external wires can pass and connect to the terminal; the upper end has corresponding mounting holes. The terminal block cover is fitted over the female connector and includes a main body and a limiting part extending downward from one end of the main body. During assembly, a manganese copper shunt, as a current sampling element, passes through the wiring hole and is embedded inside the terminal to achieve electrical connection and mechanical fixation, with its upper end extending upward and exposed through the mounting hole. When the terminal block cover is installed in place, the inner side of the limiting part abuts against the exposed end of the manganese copper shunt, thereby limiting its axial insertion depth. This structure ensures that the exposed length of each manganese-copper shunt is consistent, effectively preventing over-assembly and improving assembly accuracy, connection reliability, and overall structural stability.

[0008] Preferably, the female connector has a mounting groove for accommodating the plurality of terminals; the mounting groove has a plurality of partitions evenly distributed along its length, and the adjacent partitions form a spacer groove for fixing a single terminal.

[0009] By setting multiple spacer slots inside the wiring socket and installing each wiring terminal inside them, the installation stability of the wiring terminals can be effectively improved compared to placing them directly into the mounting slot. At the same time, the spacer also plays a role in electrical isolation, enhancing the insulation performance between adjacent phases and improving the safety and reliability of the meter operation.

[0010] Preferably, the outer wall of each of the spacers is provided with a guide groove extending upward from the mounting hole; the exposed end portion of the manganese-copper splitter is located within the guide groove.

[0011] By providing guide grooves extending upward from the mounting holes on the outer wall of each slot, and accommodating the exposed end portion of the manganese-copper splitter within these guide grooves, effective lateral support and positioning guidance can be provided for the exposed manganese-copper splitter.

[0012] Preferably, each terminal block has two threaded holes for screwing in the upper and lower terminals respectively; the main body has multiple sets of insertion holes distributed along its length, each set of insertion holes including two sub-insertion holes that are coaxially corresponding to and connected to the threaded holes.

[0013] Preferably, the outer wall of the main body is provided with an annular baffle for each set of the plug holes, the annular baffle surrounding the outer periphery of the plug hole and protruding in a direction away from the wiring female.

[0014] The annular retaining wall can effectively prevent the terminal from falling out during the unscrewing process: when the terminal is loosened for maintenance, its head can be limited and blocked from the outer periphery by the annular retaining wall.

[0015] Preferably, the annular baffle wall tapers inward at the middle to isolate the two sub-plug holes.

[0016] The annular retaining wall tapers inward in the central area between two corresponding sub-plug holes, forming a localized recess or notch structure. This design not only maintains the overall limiting function of the retaining wall but also achieves physical isolation between two adjacent sub-plug holes and their internal terminals. This isolation structure effectively prevents the risk of short circuits caused by metal tools (such as screwdrivers and wrenches) simultaneously touching two adjacent terminals during wiring or maintenance, thus improving operational safety.

[0017] Preferably, a buffer layer is provided on the inner side of the limiting part that abuts against the manganese-copper shunt.

[0018] A buffer layer is provided on the inner side of the limiting part that abuts against the exposed end of the manganese copper shunt. This can effectively relieve the rigid contact stress between the two and avoid structural damage caused by rigid contact when the manganese copper shunt is pushed in.

[0019] A three-phase electricity meter includes the aforementioned three-phase electricity meter terminal block, and also includes a housing and a metering unit disposed within the housing, the housing further including an upper housing disposed on the lower housing.

[0020] Preferably, the side wall of the lower housing is provided with a first fastening member, the side wall of the wiring female is provided with a second fastening member, and the bottom inner wall of the lower housing is provided with a support rib for supporting the wiring female.

[0021] By providing a first fastening element on the side of the lower housing, which mates with a corresponding second fastening element on the side wall of the terminal block, a quick-connecting connection between the terminal block and the lower housing is achieved. This fastening structure eliminates the need for additional fasteners (such as screws or clips), enabling secure installation of the terminal block module. Furthermore, this connection method is detachable, facilitating quick disassembly for later maintenance, replacement, or repair without affecting the structure of other components, thus improving product service convenience and maintainability.

[0022] Compared with the prior art, the beneficial effects of the present invention are reflected in: 1. The terminal block cover includes a limiting part for contacting the manganese copper shunt, which can achieve precise positioning of the manganese copper shunt. This avoids the risk of local current concentration and thermal stress caused by structural slotting, and significantly improves the accuracy and assembly efficiency of shunt installation. It effectively ensures the stability of the sampling signal and the reliability of the main current circuit, thereby comprehensively improving the measurement accuracy and long-term operation safety of the meter.

[0023] 2. A buffer layer is provided on the inner side of the limiting part that abuts against the manganese copper shunt to avoid structural damage caused by rigid contact when the manganese copper shunt is pushed in.

[0024] 3. A guide groove is provided on the outer wall of each partition groove, and the exposed end of the manganese copper splitter is housed in the guide groove, which can provide effective lateral support and positioning guidance for the exposed manganese copper splitter.

[0025] 4. The terminal block module is detachably mounted on the lower housing via the second fastener of the wiring female, which facilitates future maintenance and replacement without the need to replace the entire meter.

[0026] 5. The main body of the terminal block cover is provided with an annular baffle, which can effectively prevent the terminals from coming loose during the unscrewing process. At the same time, the annular baffle contracts inward in the middle area between the two corresponding sub-plug holes, which can achieve physical isolation between the two adjacent terminals. This effectively prevents the risk of short circuit caused by metal tools (such as screwdrivers and wrenches) touching two adjacent terminals at the same time during wiring or maintenance, thus improving operational safety. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the overall structure of a three-phase electricity meter. Figure 2 This is a schematic diagram of the terminal block module installation; Figure 3 This is a schematic diagram of the casing structure of a three-phase electricity meter; Figure 4 This is a front view schematic diagram of the overall structure of the terminal block module; Figure 5 This is a side view of the overall structure of the terminal block module; Figure 6 This is a schematic diagram of the overall fit between the female connector and the terminal block; Figure 7 yes Figure 6 Schematic diagram of the center-connection female connector structure; Figure 8 This is a schematic diagram of the wiring female connector from another perspective; Figure 9 This is a schematic diagram of the installation of the wiring terminals and the manganese copper shunt; Figure 10 This is a schematic diagram of the structure of the terminal block cover and the manganese copper shunt. Figure 11 This is a schematic diagram of the overall structure of the terminal block cover; Figure 12 This is a schematic diagram of the mating structure between the terminal block cover and the terminal post.

[0028] in: 1-Housing; 11-Lower housing; 111-First fastener; 112-Support rib; 12-Upper housing; 2-Terminal base module; 21-Wiring female base; 211-Wiring hole; 212-Mounting hole; 213-Mounting groove; 2131-Partition; 2132-Gap groove; 2133-Guide groove; 214-Second fastener; 22-Wiring terminal; 221-Threaded hole; 23-Terminal base cover; 231-Main body; 2311-Plug-in hole; 2312-Annular baffle; 232-Limiting part; 3-Manganese copper shunt; 4-Terminal post; 5-Metering unit. Detailed Implementation

[0029] To make the technical means, inventive features, objectives, and effects of the invention readily understandable, the invention is further described below with reference to specific illustrations. However, the invention is not limited to the embodiments described below.

[0030] It should be noted that the structures, proportions, sizes, etc., illustrated in the accompanying drawings of this specification are only used to complement the content disclosed in the specification for those skilled in the art to understand and read, and are not intended to limit the conditions under which the present invention can be implemented. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size, without affecting the effects and objectives that the present invention can produce, should still fall within the scope of the technical content disclosed in the present invention.

[0031] Example 1:

[0032] like Figures 1 to 3As shown, a three-phase electricity meter includes a housing 1 and a metering unit 5 installed inside the housing 1. The housing 1 consists of a lower housing 11 and an upper housing 12, with the upper housing 12 detachably mounted on the lower housing 11, together forming a sealed accommodating space for protecting the internal electronic components. A first fastener 111 is provided on the side wall of the lower housing 11, and a supporting rib 112 is provided on the bottom inner wall.

[0033] The core improvement of this application lies in the terminal block module 2 installed on the lower housing 11. This module is used to enable the connection of external wires, the sampling of current signals, and the electrical connection with the metering unit 5. Through the optimized design of its structure, the wiring reliability, assembly accuracy, and maintenance convenience are significantly improved.

[0034] Specifically, such as Figures 4 to 6 As shown, the terminal block module 2 mainly includes a wiring female block 21, multiple wiring terminals 22, and a terminal block cover 23.

[0035] The terminal block 21 has a second fastening element 214 on its side wall that mates with the first fastening element 111 on the side wall of the lower housing 11. A support rib 112 is secured to the bottom of the terminal block 21, providing stable support and enabling a quick connection between the terminal block and the lower housing 11. This fastening structure requires no additional fasteners (such as screws or clips) to securely install the terminal block module 2. Furthermore, this connection method is detachable, facilitating quick disassembly for later maintenance, replacement, or repair without affecting the structure of other components, thus improving the product's service convenience and maintainability.

[0036] like Figure 6 As shown, multiple terminals 22 are arranged inside the terminal block 21 according to the phase sequence and circuit layout requirements of three-phase electricity. Further, as... Figures 6 to 8 As shown, the female connector 21 has a mounting groove 213 extending along its length. Multiple partitions 2131 are evenly distributed inside the mounting groove 213, and spacer slots 2132 are formed between adjacent partitions 2131 to secure individual terminals 22. The dimensions of the spacer slots 2132 precisely match the terminals 22, ensuring that each terminal can be securely installed and preventing loosening or displacement. The partitions 2131 not only provide mechanical positioning but also serve as electrical isolation, enhancing the insulation performance between adjacent phases and improving the safety and reliability of the system.

[0037] Furthermore, each interval slot 2132 has a corresponding wiring hole 211 at its lower end, through which external wires can pass from below the lower housing 11 and enter to achieve electrical connection with the wiring terminal 22 located in the interval slot 2132; correspondingly, each interval slot 2132 has a mounting hole 212 communicating with it at its upper end. During assembly, the manganese copper shunt 3, as a current sampling element, is inserted from bottom to top through the wiring hole 211, extending into the wiring terminal 22, and achieves reliable electrical connection and mechanical fixation through crimping or interference fit. Its upper end continues to extend upward and protrudes outward through the mounting hole 212 to establish an electrical connection with the measuring circuit inside the meter or the upper PCB board.

[0038] To improve the structural stability of the exposed end of the manganese-copper shunt 3 and prevent it from swaying, bending, or "seesaw" deformation due to stress during assembly or use, a guide groove 2133 extending upward from the mounting hole 212 is provided on the outer wall of each spacer slot 2132. The exposed portion of the manganese-copper shunt 3 is at least partially housed within this guide groove 2133. The guide groove 2133 provides lateral support and axial guidance for the exposed section of the manganese-copper shunt 3, effectively limiting its lateral displacement and rotational freedom, improving the overall structural rigidity, and avoiding damage caused by vibration or insertion / removal forces. It also helps guide the alignment of the terminal block cover 23 during assembly, improving assembly accuracy and yield.

[0039] like Figure 9 As shown, terminal 22 is a metal conductive component with a cylindrical structure that extends vertically, facilitating the insertion of external wires from the bottom and their contact with the internal manganese-copper shunt 3 for conduction. Two threaded holes 221 are symmetrically formed in the upper region of terminal 22 for screwing in the upper and lower terminals 4 (see Figure 1). Figure 4 In actual wiring operations, the operator first loosens terminal 4, inserts the external wire into terminal hole 211 and pushes it into terminal 22, making it make electrical contact with manganese copper shunt 3; then, the operator retightens terminal 4, using its end to press the wire, achieving a secure electrical connection and mechanical clamping. This dual-terminal design supports multi-directional wiring needs, improving wiring flexibility and on-site installation efficiency.

[0040] like Figure 5 As shown, the terminal block cover 23 is positioned above the wiring female connector 21 to protect, insulate, and structurally limit the internal electrical components. Its specific structure is as follows... Figures 10 to 12As shown, it mainly includes a main body 231 and a limiting part 232. The main body 231 fits and covers the upper surface of the terminal block 21 to achieve overall encapsulation. The limiting part 232 extends downward from one end of the main body 231 (i.e., towards the terminal block 21). When the terminal block cover 23 is fully assembled, the inner side of the limiting part 232 abuts against the exposed ends of each manganese copper shunt 3 extending upward, thereby limiting the axial insertion depth of the manganese copper shunt 3, ensuring that its exposed length is consistent, and avoiding poor contact or structural damage to the upper circuit board due to excessive insertion. In this embodiment, to alleviate the rigid contact stress between the limiting part 232 and the metal ends of the manganese copper shunt 3, a buffer layer is provided on the inner side of the limiting part 232 (i.e., the surface in contact with the manganese copper shunt 3). This buffer layer can be made of an elastic insulating material (such as silicone, rubber, or polyurethane) and has a certain compression resilience. During assembly, the buffer layer can absorb the impact and stress caused by dimensional tolerances, material deformation or uneven pushing force, effectively preventing the manganese copper shunt from being crushed, deformed or developing micro-cracks at the three ends, thus ensuring its long-term stability and measurement accuracy as a current sampling element.

[0041] Furthermore, the main body 231 is provided with multiple sets of insertion holes 2311 distributed along its length. Each set of insertion holes 2311 includes upper and lower sub-insertion holes, which correspond one-to-one with and are coaxially connected to the threaded holes 221 on the terminal block 22. Operators can insert tools (such as screwdrivers) through the insertion holes 2311 and drive the terminal block 4 to rotate, smoothly screwing it into the threaded hole 221 to achieve wire clamping and fixing. This design not only facilitates wiring operations but also serves as a guide and positioning mechanism, preventing terminal block misalignment or thread damage.

[0042] To prevent the terminals 4 from accidentally falling out or into the meter after being fully loosened, thus posing a safety hazard, an annular retaining wall 2312 is provided around the outer periphery of each set of plug holes 2311. This annular retaining wall 2312 protrudes upwards from the outer wall of the main body 231, surrounding the plug hole 2311, and axially restricts the head of the terminal 4. Preferably, the annular retaining wall 2312 tapers inwards in the middle region between two corresponding sub-plug holes, forming a local recess or notch structure. This tapering design maintains the overall limiting function while achieving physical isolation between adjacent terminals 4, effectively avoiding the risk of short circuits caused by metal tools (such as screwdrivers and wrenches) simultaneously touching two adjacent terminals during wiring or maintenance. Furthermore, this structure also serves as a visual and tactile marker, making it easier for operators to distinguish between different potential terminals, reducing the probability of misoperation, and significantly improving wiring safety and maintenance convenience.

[0043] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Those skilled in the art should understand that the present invention includes, but is not limited to, the contents described in the accompanying drawings and the specific embodiments above. Any modifications that do not depart from the functional and structural principles of the present invention will be included within the scope of the claims.

Claims

1. A three-phase meter terminal block, comprising a terminal block module (2) mounted on a lower housing (11), characterized in that, The terminal block module (2) includes: Wiring female socket (21), multiple wiring terminals (22) installed in the wiring female socket (21), and terminal cover (23) disposed on the wiring female socket (21); Each of the terminal blocks (22) is provided with a manganese copper shunt (3). The lower end of the terminal block (21) is provided with a plurality of wiring holes (211) for the manganese copper shunt (3) to pass through, and the upper end is provided with a mounting hole (212) for the manganese copper shunt (3) to pass through. The terminal block cover (23) includes a main body (231) covering the terminal block (21) and a limiting part (232) extending from one end of the main body (231) toward the terminal block (21). The inner side of the limiting part (232) abuts against the end of the manganese copper shunt (3) to limit the axial insertion depth of the manganese copper shunt (3).

2. The three-phase meter terminal block according to claim 1, characterized in that: The wiring female (21) has an installation groove (213) for accommodating multiple wiring terminals (22); the installation groove (213) has multiple partitions (2131) evenly distributed along its length, and the adjacent partitions (2131) form a spacer groove (2132) for fixing a single wiring terminal (22).

3. The three-phase meter terminal block according to claim 2, characterized in that: Each of the spacer slots (2132) has a guide groove (2133) extending upward from the mounting hole (212) on its outer wall; the exposed end portion of the manganese copper splitter (3) is located in the guide groove (2133).

4. The three-phase meter terminal block according to claim 1, characterized in that: Each of the terminals (22) has two threaded holes (221) through it for screwing in the upper and lower terminals (4) respectively; the main body (231) has multiple sets of plug holes (2311) distributed along its length direction, and each set of plug holes (2311) includes two sub-plug holes that are coaxially corresponding to and connected to the threaded holes (221).

5. The three-phase meter terminal block according to claim 4, characterized in that: The outer wall of the main body (231) is provided with an annular baffle (2312) corresponding to each set of the plug holes (2311). The annular baffle (2312) surrounds the outer periphery of the plug hole (2311) and protrudes in a direction away from the wiring female (21).

6. The three-phase meter terminal block according to claim 5, characterized in that: The annular baffle (2312) tapers inward in the middle to isolate the two sub-plug holes.

7. The three-phase meter terminal block according to claim 1, characterized in that: A buffer layer is provided on the inner side of the limiting part (232) that abuts against the manganese copper diverter (3).

8. A three-phase electricity meter, characterized in that: The device includes a three-phase meter terminal block as described in any one of claims 1-7, and also includes a housing (1) and a metering unit (5) disposed within the housing (1). The housing (1) further includes an upper housing (12) disposed on the lower housing (11).

9. The three-phase meter according to claim 8, characterized in that: The lower housing (11) is provided with a first fastener (111) on its side wall, and the wiring female (21) is provided with a second fastener (214) on its side wall. The lower housing (11) is provided with a support rib (112) on its bottom inner wall for supporting the wiring female (21).

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