A shunt trip unit and a circuit breaker

Abstract

This utility model relates to a trip unit, specifically a shunt trip unit and a circuit breaker, including a trip unit housing, a first micro switch, a second micro switch, and an auxiliary foot. The trip unit housing has a positioning surface; the first micro switch is installed inside the trip unit housing and abuts against the positioning surface; the second micro switch is installed on the outside of the side of the trip unit housing and abuts against the positioning surface; the auxiliary foot is connected to the bottom of the trip unit housing via a second rotation center shaft, and a torsion spring is also provided on the second rotation center shaft; the auxiliary foot includes a first trigger foot abutting against the second micro switch and a second trigger foot abutting against the first micro switch. Compared with the prior art, this utility model solves the problem that the auxiliary and shunt trip units occupy a large space in the circuit breaker and cannot guarantee simultaneous triggering in the prior art. This solution installs the auxiliary micro switch on the side of the shunt trip unit body, thereby reducing the overall height of the accessory, and also makes the trigger surfaces of the two micro switches on the same plane to achieve simultaneous triggering.

Description

Technical Field

[0001] This utility model relates to a trip unit, specifically a shunt trip unit and a circuit breaker. Background Technology

[0002] As the automation level of power systems continues to increase, the functional requirements for electrical components are also increasing. For low-voltage electrical components, communication, remote control, and condition monitoring functions are required. At the same time, with the rapid development of new energy industries, such as photovoltaic power generation and energy storage systems, higher requirements are being placed on the performance and functionality of low-voltage electrical components and their accessories.

[0003] Currently, shunt trip + auxiliary circuits can ensure the safe and stable operation of the system, and small-shell shunt trip + auxiliary circuit accessories are widely used in substations, factory power distribution systems and other scenarios. Therefore, the demand for small-shell shunt trip + auxiliary circuit accessories is increasing rapidly.

[0004] CN118263065A discloses a transmission and mounting structure for an auxiliary alarm and shunt undervoltage accessory of a circuit breaker, including a trip unit housing. The characteristic feature is that the trip unit housing houses an auxiliary switch, an alarm switch, a moving contact, an auxiliary push rod, an undervoltage trip unit, and a shunt trip unit. However, this proposed solution separates the shunt trip unit and the auxiliary switch, resulting in two independent structural configurations and thus occupying a relatively large space.

[0005] CN120221338A discloses a molded case circuit breaker with an integrated shunt trip auxiliary accessory, which includes a housing and a cover mounted on the housing. The housing contains a contact assembly, an operating assembly, an arc extinguishing assembly, and an auxiliary assembly. The operating assembly includes a rotating shaft rotatably disposed within the housing, a transmission component disposed on the rotating shaft for linkage with the contact assembly, and a handle for driving the rotating shaft to rotate. The auxiliary assembly includes a base and a cover plate. The base contains an indicator module for displaying the circuit breaker's opening and closing status and a shunt trip module for remotely controlling the circuit breaker's opening and closing. The cover plate has a mounting cavity communicating with the interior of the housing, and the exterior of the cover plate has a fixing component for fixing the auxiliary assembly within the mounting cavity. While the auxiliary and shunt excitation accessory solves the problem of auxiliary and shunt excitation occupying space in the switch accessory slot to some extent, freeing up more space for the switch, the shunt excitation trigger microswitch (second switch) and the auxiliary microswitch are both located below the shunt excitation coil, resulting in an increased overall height and increasing the height of the switch, still requiring a significant amount of space. Furthermore, in the existing technology, the two are triggered independently, requiring corresponding structural components, leading to a complex structure and an inability to guarantee simultaneous triggering. Utility Model Content

[0006] The purpose of this invention is to provide a shunt trip unit and a circuit breaker to solve at least one of the aforementioned problems, thereby addressing the issues in the prior art where auxiliary and shunt trip units occupy a large space in the circuit breaker and cannot guarantee simultaneous triggering. This solution installs the auxiliary microswitch (second microswitch) on the side of the shunt trip unit body, thus reducing the overall height of the shunt trip + auxiliary accessories. Furthermore, it places the trigger surfaces of the two microswitches on the same plane (positioning surface), enabling simultaneous triggering through the rotation and compression of the auxiliary foot.

[0007] The objective of this utility model is achieved through the following technical solution:

[0008] The first aspect of this utility model discloses a shunt trip unit, including a trip unit housing, a first micro switch, a second micro switch, and an auxiliary foot;

[0009] The trip unit housing is provided with a positioning surface, which extends from the inside of the trip unit housing to the outside of the side of the trip unit housing;

[0010] The first micro switch is installed inside the trip unit housing, and the trigger button of the first micro switch abuts against the positioning surface; the second micro switch is installed on the outside side of the trip unit housing, and the trigger button of the second micro switch abuts against the positioning surface.

[0011] The auxiliary foot is connected to the bottom of the trip unit housing via a second rotation center shaft, and a torsion spring is also provided on the second rotation center shaft; the fixed side of the torsion spring abuts against the trip unit housing, and the force-applying side of the torsion spring abuts against the auxiliary foot.

[0012] The auxiliary foot includes a first trigger foot and a second trigger foot; the first trigger foot abuts against a second micro switch, and the second micro switch is located between the first trigger foot and the positioning surface; the second trigger foot abuts against the first micro switch, and the first micro switch is located between the second trigger foot and the positioning surface.

[0013] Preferably, the trip unit housing includes a base and a cover;

[0014] The first micro switch, the second micro switch, and the auxiliary foot are all mounted on the base;

[0015] The cover encloses the top of the second micro switch and the base.

[0016] Preferably, the auxiliary foot further includes a pivot trigger foot;

[0017] The rotating shaft trigger foot extends from the bottom of the trip unit housing and is used to engage with the rotating shaft of the circuit breaker.

[0018] Preferably, the shunt trip unit further includes an iron core, a coil, an armature, and a striking foot;

[0019] The iron core is installed inside the trip unit housing;

[0020] The coil is installed inside the iron core, and the two ends of the coil are connected in series with the common terminal and normally closed terminal of the first micro switch, respectively.

[0021] The armature is installed inside the coil and can slide along the coil axis;

[0022] The striking foot is connected to the iron core via the first rotation center shaft and is used to work in conjunction with the traction rod of the circuit breaker.

[0023] Preferably, the coil is positioned above the first micro switch, and the second micro switch is mounted on the side of the iron core.

[0024] Preferably, the first micro switch and the second micro switch form an L-shaped structure, and the first trigger pin and the second trigger pin form a U-shaped structure.

[0025] Preferably, the common terminal, normally closed terminal and normally open terminal of the second micro switch are led out to the outside of the trip unit housing via lead wires.

[0026] The second aspect of this utility model discloses a circuit breaker, including a circuit breaker housing, an operating mechanism, a rotating shaft, a traction rod, and a shunt trip unit as described above;

[0027] The operating mechanism is installed inside the circuit breaker housing;

[0028] The rotating shaft is installed inside the circuit breaker housing and is located below the operating mechanism;

[0029] The traction rod is installed inside the circuit breaker housing and is located on the rear side of the operating mechanism;

[0030] The shunt trip unit is installed inside the circuit breaker housing and is located on the side of the operating mechanism.

[0031] Preferably, the circuit breaker housing includes a middle cover and a base;

[0032] The operating mechanism, rotating shaft, traction rod, and shunt trip unit are all mounted in the base;

[0033] The middle cover fits onto the base.

[0034] Preferably, an arc-extinguishing chamber is provided inside the circuit breaker housing, a moving contact bridge is provided on the rotating shaft, and a stationary contact bridge is provided at the bottom of the circuit breaker housing; both the moving contact bridge and the stationary contact bridge extend into the arc-extinguishing chamber.

[0035] The working principle of this utility model is as follows:

[0036] A positioning surface is provided on the base. The trigger buttons of the first micro switch and the second micro switch both abut against the positioning surface. Since the positioning surfaces that the two abut against are on the same plane, the rotation of the auxiliary foot around the second rotation center axis can trigger the buttons of the two micro switches at the same time, which improves the synchronization of the auxiliary foot triggering the two.

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] (1) In this design, the second micro switch, which performs the auxiliary function, is placed on the side of the shunt trip unit body. This reduces the overall height of the shunt trip unit and makes full use of the space gap on the side without increasing the width too much. As a result, the shunt trip unit of this design can have a higher degree of spatial integration.

[0039] (2) The positioning surfaces of the two microswitches in this scheme are the same plane in the shunt trip unit, and their opposite backs are pressed by the same auxiliary foot. Therefore, the structural design of this scheme can ensure that the trigger buttons of the two microswitches are triggered at the same time, which effectively improves the synchronization of the triggering of the two. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of the structural installation of a shunt trip unit in a circuit breaker.

[0041] Figure 2 This is a structural diagram of the main operating components in a circuit breaker;

[0042] Figure 3 This is a schematic diagram of the operating mechanism and rotating shaft in a circuit breaker.

[0043] Figure 4 This is a structural diagram of some components of a shunt trip unit;

[0044] Figure 5 This is a schematic diagram of the shunt trip unit (cover not shown);

[0045] Figure 6 This is a front view schematic diagram of the shunt trip unit.

[0046] Figure 7 This is a rear view schematic diagram of the shunt trip unit.

[0047] Figure 8 This is a schematic diagram of the linkage between the shunt trip unit and the rotating shaft;

[0048] Figure 9 This is a schematic diagram of the auxiliary foot in a shunt trip unit;

[0049] Figure 10This is a wiring diagram of the first micro switch and the coil;

[0050] Figure 11 This is a wiring diagram for the second micro switch;

[0051] Figure 12 This is a schematic diagram of the positioning surface on the base of the shunt trip unit;

[0052] Figure 13 This is a schematic diagram of the structure of the first micro switch, the second micro switch, and the auxiliary pin in the shunt trip unit;

[0053] Figure 14 A schematic diagram of the structure of a shunt trip unit when it has a tendency to trip.

[0054] Figure 15 A schematic diagram of the structure of a shunt trip unit when it has a tendency to close.

[0055] Figure 16 This is a structural diagram of the shunt trip unit, rotating shaft, operating mechanism, and traction rod.

[0056] In the diagram: 1. Middle cover; 2. Shunt trip unit; 3. Base; 4. Operating mechanism; 5. First micro switch; 6. Second micro switch; 7. Coil; 8. Rotating shaft; 9. Moving contact bridge; 10. Traction rod; 11. Iron core; 12. Armature; 13. Striking foot; 14. First rotation center shaft; 15. Second rotation center shaft; 16. Auxiliary foot; 17. Torsion spring; 18. Positioning surface; 19. Cover; 20. First trigger foot; 21. Second trigger foot; 22. Rotating shaft trigger foot; 23. Base. Detailed Implementation

[0057] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0058] Example

[0059] Please see Figure 1-16 .

[0060] A shunt trip unit 2 includes a trip unit housing, a first micro switch 5, a second micro switch 6, and an auxiliary foot 16;

[0061] The trip unit housing is provided with a positioning surface 18, which extends from the inside of the trip unit housing to the outside of the side of the trip unit housing;

[0062] The first micro switch 5 is installed inside the trip unit housing, and the trigger button of the first micro switch 5 abuts against the positioning surface 18; the second micro switch 6 is installed on the outside side of the trip unit housing, and the trigger button of the second micro switch 6 abuts against the positioning surface 18.

[0063] The auxiliary foot 16 is connected to the bottom of the trip unit housing via the second rotation center shaft 15, and a torsion spring 17 is also provided on the second rotation center shaft 15; the fixed side of the torsion spring 17 abuts against the trip unit housing, and the force-applying side of the torsion spring 17 abuts against the auxiliary foot 16.

[0064] The auxiliary foot 16 includes a first trigger foot 20 and a second trigger foot 21; the first trigger foot 20 abuts against the second micro switch 6, and the second micro switch 6 is located between the first trigger foot 20 and the positioning surface 18; the second trigger foot 21 abuts against the first micro switch 5, and the first micro switch 5 is located between the second trigger foot 21 and the positioning surface 18.

[0065] A circuit breaker includes a circuit breaker housing, an operating mechanism 4, a rotating shaft 8, a traction rod 10, and a shunt trip unit 2 as described above;

[0066] The operating mechanism 4 is installed inside the circuit breaker housing;

[0067] The rotating shaft 8 is installed inside the circuit breaker housing and is located below the operating mechanism 4;

[0068] The traction rod 10 is installed inside the circuit breaker housing and is located on the rear side of the operating mechanism 4;

[0069] The shunt trip unit 2 is installed inside the circuit breaker housing and is located on the side of the operating mechanism 4.

[0070] More specifically, in this embodiment:

[0071] like Figure 1 As shown, the circuit breaker includes a base 3, a middle cover 1 fixed to the base 3 by threaded fittings, a shunt trip unit 2, an operating mechanism 4, a rotating shaft 8, and a traction rod 10 located within the base 3 and the middle cover 1. Figure 2 and Figure 3 As shown, the traction rod 10 is rotatably mounted on the rear side of the operating mechanism 4, and the rotating shaft 8 is rotatably mounted below the operating mechanism 4. The operating mechanism 4, the rotating shaft 8, and the traction rod 10 are respectively installed in the base 3. An arc-extinguishing chamber is also provided in the base 3, and a stationary contact bridge is installed at the bottom. A moving contact bridge 9 is also connected to the rotating shaft 8. Both the moving contact bridge 9 and the stationary contact bridge are located in the arc-extinguishing chamber. In this circuit breaker: the operating mechanism 4 operates the rotating shaft 8 to rotate counterclockwise to achieve closing, and rotates clockwise to achieve opening; and the traction rod 10 is tripped by rotating counterclockwise.

[0072] like Figure 4 , Figure 5 , Figure 6 and Figure 12 , Figure 13As shown, the shunt trip unit 2 specifically includes a first micro switch 5, a second micro switch 6, a coil 7, an iron core 11, an armature 12, a striking foot 13, a first rotation center shaft 14, a second rotation center shaft 15, an auxiliary foot 16, a torsion spring 17, a cover 19, and a base 23.

[0073] Base 23, such as Figure 12 As shown, the overall structure is arc-shaped and can be divided into three installation areas from top to bottom; the upper part is used to install the iron core 11, the middle part is used to install the first micro switch 5 and the second micro switch 6, and the lower part is used to install the auxiliary foot 16.

[0074] like Figure 12 and Figure 13 As shown, a horizontal mounting plate is located in the middle of the base 23. A positioning post is provided on the mounting plate. The first micro switch 5 is mounted flat on the base 23 via the positioning post. The second micro switch 6 is supported vertically on the portion of the mounting plate that extends out of the base 23 from the left side. The first micro switch 5 and the second micro switch 6 form an L-shaped structure. A Z-shaped positioning block is provided on the front side of the mounting plate, perpendicular to the mounting plate. This positioning block extends from the inside of the base 23 to the outside of the left side. Specifically, the side of the positioning block facing the first micro switch 5 and the second micro switch 6 (the rear side) is the positioning surface 18. The trigger button of the first micro switch 5 abuts against the positioning surface 18 of the positioning block located inside the base 23, while the trigger button of the second micro switch 6 abuts against the positioning surface 18 of the positioning block located outside the base 23.

[0075] A pair of snap-fit ​​structures are arranged opposite each other on the upper part of the base 23, and the iron core 11 is mounted on the upper part of the first micro switch 5 through the pair of snap-fit ​​structures. The iron core 11 is a U-shaped structure with the opening facing backward. The coil 7 is installed inside the iron core 11 along the front-back direction and is placed on the first micro switch 5. The second micro switch 6 is mounted on the left side of the iron core 11. An armature 12 is also installed inside the coil 7, and the armature 12 can slide along the axial direction of the coil 7 under the action of a magnetic field. A striking foot 13 is mounted at the rear of the iron core 11 through the first rotation center shaft 14. The striking foot 13 can rotate around the first rotation center shaft 14. The striking foot 13 is also provided with a baffle, through which the armature 12 passes. Thus, the movement of the armature 12 will drive the movement of the striking foot 13. The cover 19 of the shunt trip unit 2 covers the iron core 11 and the second micro switch 6.

[0076] like Figure 7As shown, a second rotational central shaft 15 is connected to the lower part of the base 23. An auxiliary foot 16 is mounted on the second rotational central shaft 15 and can rotate around the second rotational central shaft 15. A torsion spring 17 is also mounted on the second rotational central shaft 15. The fixed side of the torsion spring 17 abuts against the base 23, and the force-applying side of the torsion spring 17 abuts against the auxiliary foot 16, so that the auxiliary foot 16 will generate a counterclockwise torque synchronously when it rotates around the second rotational central shaft 15.

[0077] Further as Figure 8 and Figure 9 As shown, the auxiliary foot 16 has an approximate Y-shaped structure. Its upper part comprises a U-shaped first trigger foot 20 and a second trigger foot 21, which respectively abut against the surfaces of the first microswitch 5 and the second microswitch 6. This allows the first microswitch 5 and the second microswitch 6 to abut against the positioning surface 18 and the first trigger foot 20 and the second trigger foot 21 of the auxiliary foot 16. Since the trigger buttons of both the first microswitch 5 and the second microswitch 6 abut against the positioning surface 18, and the positioning surface 18 is actually the same plane, the auxiliary foot 16 can simultaneously trigger the trigger buttons of both microswitches when rotated, effectively improving the synchronization of the triggering of both. Furthermore, the lower part of the auxiliary foot 16 is also provided with a rotating shaft trigger foot 22, which is used to engage with the rotating shaft 8 of the circuit breaker to realize the actuation transmission between the microswitches and the circuit breaker.

[0078] like Figure 10 As shown, the two ends of coil 7 are connected in series with the common terminal and normally closed terminal of the first micro switch 5, respectively; Figure 11 As shown, the common terminal, normally closed terminal, and normally open terminal of the second micro switch 6 are led out to the outside of the shunt trip unit 2 through leads for user wiring.

[0079] When a circuit breaker equipped with the shunt trip unit 2 is used, such as Figure 14 , Figure 15 , Figure 16 As shown:

[0080] When the switch is closed, the rotating shaft 8 rotates counterclockwise, causing the moving contact bridge 9 to close. Figure 15 Then, the rotating shaft 8 contacts the rotating shaft trigger foot 22, and drives the auxiliary foot 16 to rotate clockwise around the second rotation center axis 15, so that the first trigger foot 20 and the second trigger foot 21 move away from the trigger buttons of the first micro switch 5 and the second micro switch 6 respectively, so that the two micro switches switch states.

[0081] When the switch is opened, the rotating shaft 8 rotates clockwise, causing the moving contact bridge 9 to open. Figure 14As a result, the rotating shaft 8 moves away from the rotating shaft trigger foot 22, and the torsion spring 17 drives the auxiliary foot 16 to rotate counterclockwise around the second rotation center axis 15 under the action of elastic force. Thus, the first trigger foot 20 and the second trigger foot 21 respectively contact the trigger buttons of the first micro switch 5 and the second micro switch 6, so that the two micro switches switch states.

[0082] When the first micro switch 5 is closed and the coil 7 is energized, the armature 12 is attracted forward and drives the striking foot 13 to rotate counterclockwise. In turn, the striking foot 13 strikes the traction rod 10 and causes it to rotate counterclockwise, thus disengaging the mechanism.

[0083] The above description of the embodiments is provided to enable those skilled in the art to understand and use the utility model. It will be apparent to those skilled in the art that various modifications can be easily made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present utility model is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present utility model without departing from its scope should be within the protection scope of the present utility model.

Claims

1. A shunt release characterized in that, It includes a trip unit housing, a first micro switch (5), a second micro switch (6), and an auxiliary foot (16); The trip unit housing is provided with a positioning surface (18), which extends from the inside of the trip unit housing to the outside of the side of the trip unit housing; The first micro switch (5) is installed inside the trip unit housing, and the trigger button of the first micro switch (5) abuts against the positioning surface (18); the second micro switch (6) is installed on the outside side of the trip unit housing, and the trigger button of the second micro switch (6) abuts against the positioning surface (18). The auxiliary foot (16) is connected to the bottom of the trip unit housing via the second rotation center shaft (15), and a torsion spring (17) is also provided on the second rotation center shaft (15); the fixed side of the torsion spring (17) abuts against the trip unit housing, and the force-applying side of the torsion spring (17) abuts against the auxiliary foot (16). The auxiliary foot (16) includes a first trigger foot (20) and a second trigger foot (21); the first trigger foot (20) abuts against the second micro switch (6), and the second micro switch (6) is located between the first trigger foot (20) and the positioning surface (18); the second trigger foot (21) abuts against the first micro switch (5), and the first micro switch (5) is located between the second trigger foot (21) and the positioning surface (18).

2. A shunt release according to claim 1, characterised in that The trip unit housing includes a base (23) and a cover (19); The first micro switch (5), the second micro switch (6), and the auxiliary foot (16) are all mounted on the base (23); The cover (19) encloses the top of the second micro switch (6) and the base (23).

3. A shunt release according to claim 1, wherein The auxiliary foot (16) also includes a pivot trigger foot (22); The rotating shaft trigger foot (22) extends from the bottom of the trip unit housing and is used to engage with the rotating shaft (8) of the circuit breaker.

4. A shunt release according to claim 1, wherein The shunt trip unit also includes an iron core (11), a coil (7), an armature (12), and a striking foot (13); The iron core (11) is installed inside the trip unit housing; The coil (7) is installed inside the iron core (11), and the two ends of the coil (7) are connected in series with the common terminal and normally closed terminal of the first micro switch (5), respectively. The armature (12) is installed inside the coil (7), and the armature (12) can slide along the axial direction of the coil (7); The striking foot (13) is connected to the iron core (11) via the first rotation center shaft (14) and is used to work in conjunction with the traction rod (10) of the circuit breaker.

5. A shunt release according to claim 4, wherein The coil (7) is positioned above the first micro switch (5), and the second micro switch (6) is mounted on the side of the iron core (11).

6. A shunt release according to claim 1, wherein The first micro switch (5) and the second micro switch (6) form an L-shaped structure, and the first trigger pin (20) and the second trigger pin (21) form a U-shaped structure.

7. A shunt release according to claim 1, wherein The common terminal, normally closed terminal and normally open terminal of the second micro switch (6) are respectively led out to the outside of the trip unit housing through lead wires.

8. A circuit breaker characterized by, It includes a circuit breaker housing, an operating mechanism (4), a rotating shaft (8), a traction rod (10), and a shunt trip unit (2) as described in any one of claims 1-7; The operating mechanism (4) is installed inside the circuit breaker housing; The rotating shaft (8) is installed inside the circuit breaker housing and is located below the operating mechanism (4); The traction rod (10) is installed inside the circuit breaker housing and is located on the rear side of the operating mechanism (4); The shunt trip unit (2) is installed inside the circuit breaker housing and is located on the side of the operating mechanism (4).

9. The circuit breaker of claim 8 wherein, The circuit breaker housing includes a middle cover (1) and a base (3); The operating mechanism (4), rotating shaft (8), traction rod (10) and shunt trip unit (2) are all installed in the base (3); The middle cover (1) is fitted onto the base (3).

10. The circuit breaker of claim 8, wherein, The circuit breaker housing is provided with an arc-extinguishing chamber inside, the rotating shaft (8) is provided with a moving contact bridge (9), and the bottom of the circuit breaker housing is provided with a stationary contact bridge; both the moving contact bridge (9) and the stationary contact bridge extend into the arc-extinguishing chamber.

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