Miniature residual current circuit breaker

Abstract

A miniature residual current circuit breaker, comprising a housing (10), a handle (12), an L-line circuit breaker unit (13), and an N-line leakage protection module (20). The L-line circuit breaker unit (13) is placed in a circuit breaker accommodating cavity (1000), the N-line leakage protection module (20) is placed in a leakage protection accommodating cavity (1001), and a zero-sequence current transformer (14) is provided in an accommodating hole (1002). The N-line leakage protection module (20) comprises a latch (21), a U-shaped pull rod (22), a trip lever (23), a torsion spring (24), a contact carrier (25), a spring (26), an N-line moving contact (27), and a leakage tripping assembly (30). The leakage tripping assembly (30) comprises a leakage tripping device (31), a linkage rod (32), and a tripping member (33). A wire is provided on a wiring terminal of the L-line circuit breaker unit, and one end of the wire passes through the zero-sequence current transformer (14) and is connected to the leakage tripping device (31); and one end of the tripping member (33) is provided with a tripping inclined face (331) abutting against the trip lever (23), and the tripping inclined face (331) acts along with the tripping member (33) and drives the trip lever (23) to act, achieving unlocking of the trip lever (23) and the latch (21). The miniature residual current circuit breaker has the advantages of a simple structure, stable and reliable performance, a sensitive tripping action, and a small size.

Description

A small leakage circuit breaker Technical Field

[0001] The utility model relates to the technical field of circuit breakers, in particular to a small leakage circuit breaker. Background Art

[0002] Currently, miniature circuit breakers, also known as miniature circuit breakers, are suitable for overload and short-circuit protection of AC 50 / 60Hz circuits with a rated voltage of 230 / 400V and a rated current not exceeding 125A. They can also be used for infrequent line switching under normal conditions. Miniature circuit breakers are primarily used in various locations, including industrial, commercial, high-rise, and residential buildings. A miniature leakage circuit breaker is a switch that automatically activates when the leakage current in a circuit exceeds a predetermined value, protecting personnel and electrical equipment. A miniature leakage circuit breaker consists of multiple L-line circuit breaker units and an N-line leakage protection module assembled with these L-line circuit breaker units. Existing miniature leakage protection circuit breakers have an unreasonable internal structure and layout, resulting in a large size. Furthermore, during the tripping process, the point at which the trip lever applies the locking force of the N-line leakage protection module in existing miniature leakage circuit breakers is prone to displacement, causing the trip lever's tripping force to vary. This results in unstable tripping force, unreliable tripping performance, and insensitive tripping. Summary of the Invention

[0003] The purpose of the utility model is to overcome the defects of the prior art and provide a small leakage circuit breaker with simple structure, stable and reliable performance, sensitive tripping action and small size.

[0004] To achieve the above-mentioned purpose, the present invention adopts a small leakage circuit breaker, including a shell, a handle, an L-line circuit breaker unit, and an N-line leakage protection module. The shell includes a middle frame, a first cover body arranged on one side of the middle frame, and a second cover body arranged on the other side of the middle frame. A circuit breaker accommodating chamber is formed between the middle frame and the first cover body, the L-line circuit breaker unit is placed in the circuit breaker accommodating chamber, a leakage protection accommodating chamber is formed between the middle frame and the second cover body, and the N-line leakage protection module is placed in the leakage protection accommodating chamber. The middle frame is provided with an accommodating hole connecting the circuit breaker accommodating chamber and the leakage protection accommodating chamber, a zero-sequence mutual inductor is arranged in the accommodating hole, and the N-line leakage protection module includes a lock slidably arranged in the middle frame, a U-shaped cover connected between the lock and the handle. A type pull rod, a trip button rotatably arranged in the middle frame and locked with the lock, a torsion spring arranged between the trip button and the middle frame, a contact frame rotatably arranged in the middle frame, a spring arranged between the contact frame and the middle frame, an N-line moving contact cooperating with the contact frame, and a leakage trip assembly arranged in the middle frame and cooperating with the trip button. The leakage trip assembly includes a leakage release arranged on the middle frame, a linkage rod cooperating with the leakage release, and a trip piece rotatably arranged in the middle frame and cooperating with the linkage rod. A wire is provided on the wiring terminal of the L-line circuit breaker unit, one end of the wire passes through the zero-sequence mutual inductor and is connected to the leakage release. One end of the trip piece is provided with a trip slope that abuts against the trip button. The trip slope moves with the trip piece and drives the trip button to move, thereby unlocking the trip button and the lock.

[0005] The above structure offers the following advantages: The housing houses the circuit breaker unit and the N-line leakage protection module, along with a separate chamber for the circuit breaker and the N-line leakage protection module. The independent chamber design ensures excellent insulation between the L-line circuit breaker and the N-line leakage protection module. The zero-sequence transformer is housed within a slot in the middle frame, further reducing the size of the miniature circuit breaker. The leakage release drives the trip rod via a linkage lever. The tripping ramp on the trip rod triggers the tripping action, enabling rapid and sensitive tripping. Consequently, the miniature circuit breaker offers the advantages of a simple structure, stable and reliable performance, sensitive tripping action, and compact size.

[0006] In particular, a limit block is provided on the tripping member at a side corresponding to the tripping slope. The limit block contacts one side of the tripping latch and forms a limiting cooperation between the limit block and the tripping latch. The limit block of the tripping member limits the tripping latch, ensuring more reliable transmission between the tripping member and the tripping latch.

[0007] Specifically, the lock buckle has an arcuate locking groove at its other end that mates with the jump buckle, and the jump buckle has an arcuate raised bearing surface at one end that mates with the arcuate locking groove. The arcuate locking groove rotates with the lock buckle and can engage with the arcuate raised bearing surface of the jump buckle, thereby locking the lock buckle and the jump buckle. The lock buckle engages with the arcuate raised bearing surface of the jump buckle via the arcuate locking groove, allowing the lock buckle and the jump buckle to be securely locked, thereby ensuring a more sensitive release action between the jump buckle and the lock buckle.

[0008] Specifically, the linkage rod has a positioning hole at one end, and the release rod has a positioning shaft at one end that engages with the positioning hole. The positioning shaft is inserted into the positioning hole and forms a snap-fit ​​connection between the release rod and the linkage rod. This snap-fit ​​connection facilitates assembly of the linkage rod and the release rod, improving assembly efficiency and ensuring more reliable transmission between the release rod and the linkage rod.

[0009] Specifically, a guide block is provided at the other end of the linkage rod, against which the push rod of the residual current circuit breaker contacts. A guide groove is provided on the middle frame, which cooperates with the guide block, and within which the guide block slides. The guide block guides the linkage rod, ensuring that it can reliably drive the trip rod, thereby improving the operational reliability of the small residual current circuit breaker. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] FIG1 is a perspective view of the internal structure of an embodiment of the present utility model.

[0011] FIG2 is an exploded view of an embodiment of the present invention.

[0012] FIG3 is a perspective view of the lock buckle according to an embodiment of the present invention.

[0013] FIG4 is a perspective view of a release member according to an embodiment of the present invention. DETAILED DESCRIPTION

[0014] As shown in Figures 1 to 4, an embodiment of the present invention is a small leakage circuit breaker, including a housing 10, a handle 12, an L-line circuit breaker unit 13, and an N-line leakage protection module 20. The housing 10 includes a middle frame 101, a first cover body provided on one side of the middle frame 101, and a second cover body 102 provided on the other side of the middle frame 101. A circuit breaker accommodating chamber 1000 is formed between the middle frame 101 and the first cover body. The L-line circuit breaker unit 13 is placed in the circuit breaker accommodating chamber 1000. A leakage protection accommodating chamber 1001 is formed between the middle frame 101 and the second cover body 102. The N-line leakage protection module 20 is placed in the leakage protection accommodating chamber 1001. The middle frame 101 is provided with an accommodating hole 1002 communicating between the circuit breaker accommodating chamber 1000 and the leakage protection accommodating chamber 1001. The accommodating hole 1002 is provided on the middle frame 101. A zero-sequence mutual inductor 14 is provided inside the middle frame 101, and the N-line leakage protection module 20 includes a lock 21 slidably provided in the middle frame 101, a U-shaped pull rod 22 connected between the lock 21 and the handle 12, a trip button 23 rotatably provided in the middle frame 101 and locked with the lock 21, a torsion spring 24 provided between the trip button 23 and the middle frame 101, a contact frame 25 rotatably provided in the middle frame 101, a spring 26 provided between the contact frame 25 and the middle frame 101, an N-line moving contact 27 linked with the contact frame 25, a leakage trip assembly 30 provided in the middle frame 101 and linked with the trip button 23, and the leakage trip assembly 30 includes a leakage trip device 31 provided on the middle frame 101, a linkage rod 32 linked with the leakage trip device 31, a rotationally provided in the middle frame 101 and linked with the linkage rod 32. The L-line circuit breaker unit 13 has a matching tripping member 33. A wire is provided on the terminal block of the L-line circuit breaker unit 13. One end of the wire passes through the zero-sequence transformer 14 and is connected to the leakage release 31. One end of the tripping member 33 is provided with a tripping slope 331 that abuts against the tripping latch 23. The tripping slope 331 moves with the tripping member 33 and drives the tripping latch 23 to move, thereby unlocking the tripping latch 23 and the lock latch 21.

[0015] As shown in Figures 2-4, a limit block 332 is provided on the release member 33, corresponding to the release slope 331. This limit block 332 contacts one side of the tripping latch 23, providing a position-limiting fit between the limit block 332 and the tripping latch 23. The release member's limit block limits the tripping latch, ensuring more reliable transmission between the release member and the tripping latch. The lock latch 21 has an arcuate locking groove 211 at its other end, which mates with the tripping latch 23. The tripping latch 23 has an arcuate raised bearing surface 231 at one end, which mates with the arcuate locking groove 211. The arcuate locking groove 211 rotates with the lock latch 21 and can engage with the arcuate raised bearing surface 231 of the tripping latch 23, thereby locking the lock latch 21 and the tripping latch 23. The lock catch snaps onto the curved raised bearing surface of the trip catch via an arcuate locking groove, reliably locking the lock catch and trip catch together, ensuring a more sensitive release of the trip catch and lock catch. The linkage rod 32 has a positioning hole 321 at one end, and the tripping rod 33 has a positioning shaft 333 at one end that mates with the positioning hole 321. The positioning shaft 333 is inserted into the positioning hole 321, forming a snap-fit ​​connection between the tripping rod 33 and the linkage rod 32. This snap-fit ​​connection facilitates assembly of the linkage rod and the tripping rod, improving assembly efficiency and ensuring more reliable transmission between the tripping rod and the linkage rod. A guide block 322 is provided at the other end of the linkage rod 32. The push rod 311 of the residual current circuit breaker 31 abuts against the guide block 322. The middle frame 101 is provided with a guide groove 1011 that mates with the guide block 322, and the guide block 322 slides within the guide groove 1011. The guide block guides the linkage rod, ensuring that it can reliably drive the trip rod, thereby improving the operational reliability of the small residual current circuit breaker.

[0016] The housing houses the circuit breaker unit and the N-line leakage protection module, along with a separate chamber for the circuit breaker and the N-line leakage protection module. The independent chamber design ensures proper insulation between the L-line circuit breaker and the N-line leakage protection module. The zero-sequence transformer is housed within a slot in the middle frame, reducing the size of the miniature circuit breaker. The leakage release operates via a linkage lever, a tripping rod. The tripping ramp on the trip rod triggers the tripping action, enabling rapid and sensitive tripping. This miniature circuit breaker offers the advantages of a simple structure, stable and reliable performance, sensitive tripping, and a compact size.

Claims

1. A miniature leakage circuit breaker, comprising a housing, a handle, an L-line circuit breaker unit, and an N-line leakage protection module, characterized in that: The shell includes a middle frame, a first cover body arranged on one side of the middle frame, and a second cover body arranged on the other side of the middle frame. A circuit breaker accommodating chamber is formed between the middle frame and the first cover body, the L-line circuit breaker unit is placed in the circuit breaker accommodating chamber, a leakage protection accommodating chamber is formed between the middle frame and the second cover body, and the N-line leakage protection module is placed in the leakage protection accommodating chamber. The middle frame is provided with an accommodating hole connected between the circuit breaker accommodating chamber and the leakage protection accommodating chamber, a zero-sequence mutual inductor is arranged in the accommodating hole, and the N-line leakage protection module includes a lock slidably arranged in the middle frame, a U-shaped pull rod connected between the lock and the handle, a jump buckle rotatably arranged in the middle frame and locked with the lock buckle, a torsion spring arranged between the jump buckle and the middle frame, a contact frame rotatably arranged in the middle frame, a spring arranged between the contact frame and the middle frame, and an N-line leakage protection module that cooperates with the contact frame. A line-moving contact, a leakage release assembly arranged in the middle frame and matched with the trip button, the leakage release assembly includes a leakage release arranged on the middle frame, a linkage rod linked with the leakage release, and a tripping piece rotatably arranged in the middle frame and matched with the linkage rod. A wire is arranged on the wiring terminal of the L-line circuit breaker unit, one end of the wire passes through the zero-sequence mutual inductor and is connected to the leakage release, one end of the tripping piece is provided with a tripping inclined surface that abuts against the tripping button, the tripping inclined surface moves with the tripping piece and drives the tripping button to unlock the tripping button and the lock.

2. The miniature leakage circuit breaker according to claim 1, wherein: A limiting block is arranged on the release member at one side corresponding to the release inclined surface, and the limiting block abuts against one side of the jump buckle, and forms a limiting match between the limiting block and the jump buckle.

3. The miniature leakage circuit breaker according to claim 1 or 2, characterized in that: The other end of the lock buckle has an arcuate locking groove that matches the jump buckle, and one end of the jump buckle has an arcuate convex bearing surface that matches the arcuate locking groove. The arcuate locking groove rotates with the lock buckle and can be buckled on the arcuate convex bearing surface of the jump buckle, thereby realizing the locking of the lock buckle and the jump buckle.

4. The miniature residual current circuit breaker according to claim 1 or 2, characterized in that: One end of the linkage rod is provided with a positioning hole, and one end of the release rod is provided with a positioning shaft matched with the positioning hole. The positioning shaft is inserted into the positioning hole and constitutes a snap fit between the release rod and the linkage rod.

5. The miniature leakage circuit breaker according to claim 4, characterized in that: A guide block is arranged on the other end of the linkage rod, the push rod of the leakage release device abuts against the guide block, a guide groove matching with the guide block is arranged on the middle frame, and the guide block is slidably arranged in the guide groove.

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