A miniature circuit breaker

Abstract

The application relates to a miniature circuit breaker which comprises a shell, a handle assembly, a movable contact mechanism and a short-circuit instantaneous tripping system, the handle assembly is rotationally connected in the shell and extends to the outside of the shell at one end, the movable contact mechanism is rotationally connected in the shell through a lock catch hollow shaft, the movable contact mechanism is connected with the handle assembly through a connecting rod, a connecting point of the movable contact mechanism and the connecting rod is a set point, the movable contact mechanism comprises a movable contact body, the short-circuit instantaneous tripping system is arranged in the shell and comprises a static contact, a connecting line between the set point and an end point of the movable contact body is obliquely arranged, a distance between the set point and the axis of the lock catch hollow shaft is a first distance, a distance between the axis of the lock catch hollow shaft and the movable contact body is a second distance, the first distance is smaller than the second distance and greater than a second set distance, the distance between the static contact and the movable contact body is increased, and the rated short-circuit breaking capacity of the miniature circuit breaker is effectively improved.

Description

Technical Field

[0001] This application relates to the field of electrical equipment, and in particular to a miniature circuit breaker. Background Technology

[0002] Miniature circuit breakers, also known as micro circuit breakers, are the most widely used terminal protection devices in the field of electrical terminal distribution equipment, used for protection against short circuits, overloads, etc.

[0003] A key factor in improving the breaking capacity of miniature circuit breakers is increasing the opening gap to improve the voltage drop across the arc and reduce the arc current. Currently, the opening gap of miniature circuit breakers ranges from 3mm and 5mm, with some products reaching around 9mm. However, due to limitations in the existing moving contact mechanism, it is impossible to further increase the opening gap, resulting in a relatively low rated short-circuit breaking capacity. Utility Model Content

[0004] This application provides a miniature circuit breaker that can solve the problems of small opening distance and low rated short-circuit breaking capacity of miniature circuit breakers in related technologies.

[0005] This application provides a miniature circuit breaker, comprising: a housing, a handle assembly, a moving contact mechanism, and a short-circuit instantaneous tripping system. The handle assembly is rotatably connected inside the housing, with one end extending outside the housing. The moving contact mechanism is rotatably connected inside the housing via a locking hollow shaft. The moving contact mechanism and the handle assembly are connected by a connecting rod, and the connection point between the moving contact mechanism and the connecting rod is a set point. The moving contact mechanism includes a moving contact body. The short-circuit instantaneous tripping system is disposed inside the housing and includes a stationary contact. The connection line between the set point and the endpoint of the moving contact body is inclined. The distance between the set point and the axis of the locking hollow shaft is a first distance, and the distance between the axis of the locking hollow shaft and the moving contact body is a second distance. The first distance is less than the first set distance, the second distance is greater than the second set distance, and the second set distance is greater than the first set distance. When the circuit breaker is in the open state, the opening distance between the stationary contact and the moving contact body is greater than 11.5 mm.

[0006] In one embodiment, the moving contact mechanism includes: a moving contact bracket, a trip body, and a mechanism spring. The moving contact bracket is rotatably connected to the housing via a locking hollow shaft. The trip body is disposed on the moving contact bracket and connected to the handle assembly via a connecting rod. The mechanism spring is disposed inside the housing between the moving contact bracket and the housing. When the circuit breaker switch is in the open state, the mechanism spring presses against the moving contact bracket to tilt the connection line between the set point and the endpoint of the moving contact body. The moving contact body is disposed on the moving contact bracket and is connected to the moving contact bracket by a moving contact torsion spring.

[0007] In one embodiment, the moving contact mechanism further includes: a locking body and a release link, wherein the locking body is disposed on the moving contact bracket and a locking torsion spring is disposed between the locking body and the moving contact bracket; the release link is disposed on the locking body, one end of the release link is a heat element system contact end, the heat element system contact end extends away from the handle assembly and the end is bent to form a hook.

[0008] In one embodiment, the miniature circuit breaker further includes a thermal element system disposed inside the housing and located below the moving contact mechanism, with one end of the thermal element system extending toward one side of the moving contact mechanism.

[0009] In one embodiment, the thermal element system includes: a bimetallic strip, an arc-inducing strip, a connecting strip, and a first terminal block. One end of the bimetallic strip extends toward the moving contact mechanism and into the tripping linkage. The arc-inducing strip is disposed on one side of the bimetallic strip. The connecting strip is disposed on the other side of the bimetallic strip. The first terminal block is connected to the connecting strip.

[0010] In one embodiment, the short-circuit instantaneous tripping system includes: a coil frame, a first moving iron core, a second moving iron core, a push rod, a spring, a coil body, and a U-shaped magnetic conductive sheet. The coil frame is connected to the inside of the housing via a support, and the stationary contact is connected to the coil frame. The first moving iron core is disposed inside the coil frame. The second moving iron core is disposed inside the coil frame. One end of the push rod is connected to the first moving iron core, and the other end passes through the inside of the second moving iron core and extends to the outside of the coil frame. The spring is sleeved on the outer peripheral surface of the push rod, and one end is connected to the first moving iron core, while the other end is placed inside the second moving iron core. The coil body is sleeved on the outer peripheral surface of the coil frame. The U-shaped magnetic conductive sheet is connected to the support, and the stationary contact is connected to the U-shaped magnetic conductive sheet.

[0011] In one embodiment, the short-circuit instantaneous tripping system further includes a first terminal block, which is connected to the coil body.

[0012] In one embodiment, the miniature circuit breaker further includes an arc-extinguishing chamber disposed inside the housing, and one end of the short-circuit instantaneous tripping system extends into the arc-extinguishing chamber.

[0013] In one embodiment, the arc-extinguishing chamber includes: a red steel cardboard and a plurality of grid plates, the plurality of grid plates being spaced apart inside the red steel cardboard, one end of each grid plate being provided with a through groove, and one end of the stationary contact extending into the through groove.

[0014] In one embodiment, a wiring clamp is further provided inside the housing, and a wiring screw is threaded onto the wiring clamp, with one end of the short-circuit instantaneous tripping system extending into the wiring clamp.

[0015] The beneficial effects of the technical solutions provided in this application include:

[0016] This application provides a miniature circuit breaker in which the connection line between the set point and the endpoint of the moving contact body is inclined so that the moving contact body can move away from the stationary contact when the circuit breaker is in the open state. The handle assembly is connected to the moving contact mechanism via a linkage. The first distance between the set point and the center of the locking hollow shaft is set to be less than a first set distance, and the second distance between the center of the locking hollow shaft and the moving contact body is set to be greater than a second set distance. The second set distance is also set to be greater than the first set distance. The first distance is shorter and the second distance is longer, so that the handle assembly can generate a large displacement with a small operating force, which increases the opening distance between the stationary contact and the moving contact body and effectively improves the rated short-circuit breaking capacity of the miniature circuit breaker. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the overall structural shape provided in the embodiments of this application;

[0019] Figure 2 A schematic diagram of the base provided in an embodiment of this application;

[0020] Figure 3 A schematic diagram of the lid provided in an embodiment of this application;

[0021] Figure 4 This is a schematic diagram of the interior of the outer casing provided in an embodiment of this application;

[0022] Figure 5 This is a schematic diagram of the moving contact mechanism provided in an embodiment of this application;

[0023] Figure 6 This is a schematic diagram of the moving contact mechanism provided in an embodiment of this application;

[0024] Figure 7 A schematic diagram of a short-circuit instantaneous tripping system provided in an embodiment of this application;

[0025] Figure 8 This is a cross-sectional schematic diagram of a short-circuit instantaneous tripping system provided in an embodiment of this application;

[0026] Figure 9 A schematic diagram of a heat source system provided in an embodiment of this application;

[0027] Figure 10 This is a schematic diagram of the normal operating (closed) state of a miniature circuit breaker provided in the embodiments of this application.

[0028] In the diagram: 1. Outer shell; 11. Magnetic sheet structure; 12. Arc stop plate; 13. Mounting rail; 14. Cover; 15. Base; 2. Handle assembly; 20. Handle body; 21. Handle torsion spring; 3. Linkage rod; 4. Moving contact mechanism; 40. Moving contact bracket; 41. Locking body; 42. Locking torsion spring; 43. Tripping lock body; 44. Mechanism compression spring; 45. Moving contact body; 46. Tripping lock hollow shaft; 47. Locking hollow shaft; 48. Moving contact torsion spring; 49. Tripping linkage; 5. Thermal element system 50. First terminal block; 51. Flexible connecting wire; 52. Bimetallic strip; 53. Arc ignition plate; 54. Connecting plate; 6. Adjusting screw; 7. Arc extinguishing chamber; 70. Grid plate; 71. Red steel cardboard; 8. Terminal clamp; 9. Terminal screw; 10. Short circuit instantaneous tripping system; 100. Second terminal block; 101. Coil frame; 102. First moving iron core; 103. Spring; 104. Second moving iron core; 105. Push rod; 106. Coil body; 107. Stationary contact; 108. U-shaped magnetic conductor. Detailed Implementation

[0029] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present application.

[0030] This application provides a miniature circuit breaker that solves the problems of small opening distance and low rated short-circuit breaking capacity of miniature circuit breakers in related technologies.

[0031] This application provides a miniature circuit breaker, comprising: a housing 1, a handle assembly 2, a moving contact mechanism 4, and a short-circuit instantaneous tripping system 10. The handle assembly 2 is rotatably connected inside the housing 1, with one end extending outside the housing 1. The moving contact mechanism 4 is rotatably connected inside the housing 1 via a locking hollow shaft 47. The moving contact mechanism 4 and the handle assembly 2 are connected by a connecting rod 3, and the connection point between the moving contact mechanism 4 and the connecting rod 3 is a set point. The moving contact mechanism 4 includes a moving contact body 45. The short-circuit instantaneous tripping system 10 is disposed inside the housing 1. The short-circuit instantaneous tripping system 10 includes a stationary contact 107; wherein the connection line between the set point and the endpoint of the moving contact body 45 is inclined, the distance between the set point and the axis of the locking hollow shaft 47 is a first distance, and the distance between the axis of the locking hollow shaft 47 and the moving contact body 45 is a second distance. The first distance is less than the first set distance, the second distance is greater than the second set distance, and the second set distance is greater than the first set distance. When the circuit breaker switch is in the open state, the opening distance between the stationary contact 107 and the moving contact body 45 is greater than 11.5mm.

[0032] In this application, the connection line between the set point and the endpoint of the moving contact body 45 is inclined so that the moving contact body 45 can move away from the stationary contact 107 when the circuit breaker switch is open. The handle assembly 2 is connected to the moving contact mechanism 4 through the connecting rod 3. The first distance between the set point and the axis of the locking hollow shaft 47 is set to be less than the first set distance, and the second distance between the axis of the locking hollow shaft 47 and the moving contact body 45 is set to be greater than the second set distance. The second set distance is also set to be greater than the first set distance, so that the first distance is shorter and the second distance is longer. This allows the handle assembly 2 to produce a large displacement with a small operating force, increasing the opening distance between the stationary contact 107 and the moving contact body 45, and effectively improving the rated short-circuit breaking capacity of the miniature circuit breaker.

[0033] Within the limited space of this miniature circuit breaker, the mechanical amplification effect of a lever—that is, by setting a shorter first distance and a longer second distance—allows the moving contact body 45 to move a greater distance with the same operating stroke, thereby increasing the opening distance. See also... Figure 4 As shown, Figure 4 In this application, the distance between the stationary contact 107 and the moving contact body 45 is set to a threshold of 11.5 mm. This means the distance is greater than 11.5 mm, and the overtravel is set to be greater than 2.0 mm to ensure proper slow reset of the miniature circuit breaker and meet its technical requirements. Increasing the distance of the miniature circuit breaker increases the arc resistance, arc voltage drop, and arc current, and correspondingly improves its rated short-circuit breaking capacity.

[0034] The outer casing 1 includes a cover 14 and a base 15, which are assembled together by mounting rails 13, forming an assembly space inside. Furthermore, magnetic conductive sheet structures 11 and arc-blocking plates 12 are installed on the inner walls of both the cover 14 and the base 15, with their installation positions corresponding to those on the base 15. It should be noted that the magnetic conductive sheet structure 11 works in conjunction with the arc-extinguishing chamber 7 mentioned below: when the circuit breaker breaks the circuit, an electric arc is generated between the stationary contact 107 and the moving contact body 45. The arc current generates a magnetic field, and the magnetic conductive sheet structure 11 guides and concentrates the magnetic field, causing the arc to move rapidly under the influence of the magnetic force and enter the arc-extinguishing chamber 7. The arc-blocking piece 12 can prevent the arc from spreading to other parts during the breaking process, avoiding faults such as phase-to-phase short circuits or ground short circuits, and improving the reliability and safety of the circuit breaker. On the other hand, it can also increase the contact area between the arc and the solid medium, so that the heat of the arc can be dissipated more quickly, playing an auxiliary role in extinguishing the arc.

[0035] The handle assembly 2 includes a handle body 20 rotatably connected inside the housing 1, and a handle torsion spring 21 is installed between the handle body 20 and the housing 1, which can maintain the elastic force output during the repeated twisting and resetting of the handle body 20.

[0036] Based on the above embodiments, in this embodiment, the moving contact mechanism 4 includes: a moving contact bracket 40, a snap-lock body 43, and a mechanism compression spring 44.

[0037] Specifically, the moving contact bracket 40 is rotatably connected to the outer casing 1 via a locking hollow shaft 47; the trip lever body 43 is mounted on the moving contact bracket 40 via a trip lever hollow shaft 46 and is connected to the handle assembly 2 via a connecting rod 3. That is, when the handle body 20 rotates, it can drive the trip lever body 43 to rotate via the connecting rod 3. Since the trip lever body 43 is mounted on the moving contact bracket 40, it can drive the moving contact bracket 40 to rotate. The mechanism spring 44 is located inside the outer casing 1 between the moving contact bracket 40 and the outer casing 1. When the circuit breaker switch is in the open state, the mechanism spring 44 presses against the moving contact bracket 40, causing the connection line between the set point and the endpoint of the moving contact body 45 to be inclined. The moving contact body 45 is mounted on the moving contact bracket 40 and connected to the moving contact bracket 40 by a moving contact torsion spring 48. The mechanism spring 44 is in an extended state under normal conditions. Figure 4 When the handle body 20 shown rotates counterclockwise, it drives the moving contact bracket 40 to rotate clockwise, compresses the mechanism spring 44, and the moving contact body 45 gradually approaches the stationary contact 107.

[0038] Furthermore, the moving contact mechanism 4 also includes: a locking body 41 and a release link 49. The locking body 41 is mounted on the moving contact bracket 40, and a locking torsion spring 42 is provided between the locking body 41 and the moving contact bracket 40. In addition, the locking body 41 also abuts against the tripping body 43. When the tripping body 43 rotates, it can drive the locking body 41 to rotate. The release link 49 is mounted on the locking body 41. One end of the release link 49 is the contact end of the thermal element system. The contact end of the thermal element system extends away from the handle assembly 2, and the end is bent to form a hook. It should also be noted that, as Figure 4 As shown, the tripping linkage 49 is located on the front of the moving contact body 45.

[0039] Based on the above embodiments, in this embodiment, the miniature circuit breaker further includes: a thermal element system 5, which is disposed inside the housing 1 and located below the moving contact mechanism 4. One end of the thermal element system 5 extends toward the moving contact mechanism 4 and into the tripping linkage 49.

[0040] Specifically, the thermal element system 5 includes: a bimetallic strip 52, an arc-inducing piece 53, a connecting piece 54, and a first terminal block 50. One end of the bimetallic strip 52 extends towards the moving contact mechanism 4 and into the tripping linkage 49. A flexible connecting wire 51 connects the bimetallic strip 52 and the moving contact mechanism 4. The arc-inducing piece 53 is located on one side of the bimetallic strip 52. The connecting piece 54 is located on the other side of the bimetallic strip 52. The first terminal block 50 is connected to the connecting piece 54. The thermal element system 5 is located below the moving contact mechanism 4, and the bimetallic strip 52 passes through the tripping linkage 49 and is located on one side of the moving contact body 45. Furthermore, an adjusting screw 6 is threadedly connected inside the housing 1. The adjusting screw 6 is located on one side of the bimetallic strip 52 and abuts against the bimetallic strip 52. When the adjusting screw 6 is adjusted, the position of the bimetallic strip 52 can be adjusted.

[0041] Based on the above embodiments, in this embodiment, the short-circuit instantaneous tripping system 10 includes: a coil frame 101, a first moving iron core 102, a second moving iron core 104, a push rod 105, a spring 103, a coil body 106, and a U-shaped magnetic conductive sheet 108. The coil frame 101 is connected to the inside of the outer shell 1 via a support, and the stationary contact 107 is connected to the coil frame 101. The first moving iron core 102 is disposed inside the coil frame 101; the second moving iron core 104 is disposed inside the coil frame 101. Inside the frame 101; one end of the top rod 105 is connected to the first moving iron core 102, and the other end passes through the inside of the second moving iron core 104 and extends to the outside of the coil frame 101; the spring 103 is sleeved on the outer peripheral surface of the top rod 105, and one end is connected to the first moving iron core 102, while the other end is placed inside the second moving iron core 104; the coil body 106 is sleeved on the outer peripheral surface of the coil frame 101; the U-shaped magnetic sheet 108 is connected to the support, and the stationary contact 107 is connected to the U-shaped magnetic sheet 108.

[0042] See Figure 4 , Figure 7 and Figure 8 As shown, a support is installed inside the outer casing 1, and the coil frame 101 is fixed inside the support. A cavity is opened inside the coil frame 101, and both the first moving iron core 102 and the second moving iron core 104 are installed in the cavity. A through hole is opened in the middle of the second moving iron core 104, so that one end of the push rod 105 is connected to the first moving iron core 102, and the other end passes through the through hole. A spring 103 is installed between the first moving iron core 102 and the second moving iron core 104, and the first moving iron core 102 is designed to move inside the cavity. When the first moving iron core 102 moves closer to the second moving iron core 104, it can push one end of the push rod 105 out of the through hole.

[0043] Furthermore, the short-circuit instantaneous tripping system 10 also includes a first terminal block 50, which is connected to the coil body 106.

[0044] The first terminal block 50 and the U-shaped magnetic sheet 108 are respectively disposed on both sides of the coil body 106. The housing 1 is also provided with a terminal clamp 8, and a terminal screw 9 is threadedly connected to the terminal clamp 8. One end of the second terminal block 100 in the short-circuit instantaneous tripping system 10 extends into the terminal clamp 8, and the terminal screw 9 passes through the terminal clamp 8 and abuts against the second terminal block 100.

[0045] It should be noted that wiring clamps 8 and wiring screws 9 are provided on both sides inside the housing 1. One end of the first wiring plate 50 extends into the wiring clamp 8 on the other side of the housing 1, and the wiring screw 9 passes through the wiring clamp 8 and abuts against the first wiring plate 50.

[0046] Based on the above embodiments, in this embodiment, the miniature circuit breaker further includes an arc-extinguishing chamber 7, which is disposed inside the housing 1 and located below the short-circuit instantaneous tripping system 10. One end of the U-shaped magnetic conductive sheet 108 in the short-circuit instantaneous tripping system 10 extends into the arc-extinguishing chamber 7. Specifically, the arc-extinguishing chamber 7 includes a red steel plate 71 and a plurality of grid plates 70. In this embodiment, the grid plates 70 are metal grid plates 70. The plurality of grid plates 70 are spaced apart inside the red steel plate 71. One end of each grid plate 70 is provided with a through groove, and one end of the stationary contact 107 extends into the through groove. The red steel plate 71 includes a front, a back, and a side, with the other side being an opening. The through groove of the grid plate 70 is located at the opening.

[0047] The working principle of the miniature circuit breaker in this application is as follows:

[0048] In normal working (closed) state (see...) Figure 10The upper end of the moving contact mechanism 4 rotates clockwise by a certain angle, compressing the mechanism spring 44, which stores a certain amount of kinetic energy. The moving contact body 45 is in close contact with the contact point on the stationary contact 107, and the moving contact body 45 generates a certain pressure under the action of the moving contact torsion spring 48.

[0049] The miniature circuit breaker of this application can work normally when the rated operating current is In (≤63A) and the normal load current is 1.0In (A).

[0050] When the load current is 1.13In(A), the miniature circuit breaker will not trip within one hour under overload conditions (cold state), meaning the moving contact body 45 and the stationary contact 107 will not separate. When the load current rises and stabilizes at 1.45In(A) within 5 seconds, the miniature circuit breaker will trip within one hour (hot state). When the load current is 2.55In(A), the miniature circuit breaker will trip within 1 to 60 seconds (≤32A), and for products with a current >32A, it will trip within 1 to 120 seconds. This process constitutes overload protection for the miniature circuit breaker.

[0051] See Figure 10 As shown, when the miniature circuit breaker is overloaded: the bimetallic strip 52 bends to the right, causing the tripping linkage 49 to drag the latch body 41 to rotate, which in turn causes the tripping body 43 to rotate as well; under the action of the kinetic energy released by the latch torsion spring 42, the upper end of the moving contact bracket 40 rotates counterclockwise by a certain angle, and the moving contact body 45 quickly separates from the stationary contact 107. The moving contact body 45 reaches its maximum separation time within 2 to 4 milliseconds. Figure 4 The displayed state is the open state of the miniature circuit breaker (making the arc voltage drop reach its maximum value within 2-4 milliseconds). An arc is generated at the moment the moving contact body 45 and the stationary contact 107 separate. The arc flows through the conductive circuit when the moving contact body 45 and the stationary contact 107 separate, and moves along the surface of the stationary contact 107 and the moving contact body 45 in a normal state under the action of the magnetic force generated by the current. When the moving contact body 45 moves to near the opening distance limit, the top of the moving contact body 45 approaches the arc-starting plate 53. At this time, the arc breaks and enters the arc-extinguishing chamber 7 along the arc-starting plate 53 and the stationary contact 107 under the action of the magnetic force (electrodynamic force). In the arc-extinguishing chamber 7, the arc is cut into multiple arc segments by the metal grid 70, thereby extinguishing the arc. This is the overload protection process of the miniature circuit breaker.

[0052] When the instantaneous tripping current of the miniature circuit breaker is designed as type C (5In~10In): when a short circuit occurs at the load end of the miniature circuit breaker and the short circuit current reaches the condition for generating the tripping current, the magnetic force generated by the coil body 106 attracts the first moving iron core 102 to compress the spring 103. The latch body 41 is set on one side of the push rod 105 so that the push rod 105 hits the latch body 41, the tripping body 43 rotates, and the switch of the miniature circuit breaker is opened. This is the short circuit protection process of the miniature circuit breaker.

[0053] In the description of this application, it should be noted that the terms "upper," "lower," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0054] It should be noted that in this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0055] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A miniature circuit breaker, characterized in that, It includes: Outer shell (1); Handle assembly (2), which is rotatably connected to the housing (1) and has one end extending to the outside of the housing (1); The moving contact mechanism (4) is rotatably connected to the inside of the outer shell (1) via a locking hollow shaft (47). The moving contact mechanism (4) is connected to the handle assembly (2) via a connecting rod (3), and the connection point between the moving contact mechanism (4) and the connecting rod (3) is a set point. The moving contact mechanism (4) includes a moving contact body (45). A short-circuit instantaneous tripping system (10) is disposed inside the housing (1) and includes a stationary contact (107). The connection line between the set point and the endpoint of the moving contact body (45) is inclined. The distance between the set point and the axis of the locking hollow shaft (47) is the first distance, and the distance between the axis of the locking hollow shaft (47) and the moving contact body (45) is the second distance. The first distance is less than the first set distance, the second distance is greater than the second set distance, and the second set distance is greater than the first set distance. When the circuit breaker switch is in the open state, the opening distance between the stationary contact (107) and the moving contact body (45) is greater than 11.5mm.

2. The miniature circuit breaker as described in claim 1, characterized in that, The moving contact mechanism (4) includes: The moving contact bracket (40) is rotatably connected to the outer shell (1) via a locking hollow shaft (47); The jump buckle body (43) is mounted on the moving contact bracket (40) and connected to the handle assembly (2) via a connecting rod (3); Mechanism spring (44) is disposed inside the housing (1) and between the moving contact bracket (40). When the circuit breaker switch is in the open state, the mechanism spring (44) presses against the moving contact bracket (40) so that the connection line between the set point and the end point of the moving contact body (45) is set at an angle. The moving contact body (45) is mounted on the moving contact bracket (40), and a moving contact torsion spring (48) is connected between the moving contact body and the moving contact bracket (40).

3. The miniature circuit breaker as described in claim 2, characterized in that, The moving contact mechanism (4) further includes: The latch body (41) is disposed on the moving contact bracket (40), and a latch torsion spring (42) is disposed between the latch body (41) and the moving contact bracket (40). Release link (49), the release link (49) is disposed on the lock body (41), one end of the release link (49) is the heat element system contact end, the heat element system contact end extends away from the handle assembly (2) and the end is bent to form a hook.

4. The miniature circuit breaker as described in claim 3, characterized in that: The miniature circuit breaker also includes: The heat source system (5) is located inside the outer shell (1) and is located to the right and below the moving contact mechanism (4).

5. The miniature circuit breaker as described in claim 4, characterized in that, The heat element system (5) includes: A bimetallic strip (52), one end of which extends toward the moving contact mechanism (4); Arc-inducing plate (53), wherein the arc-inducing plate (53) is disposed on one side of the bimetallic plate (52); A connecting piece (54) is disposed on the other side of the bimetallic strip (52); The first terminal block (50) is connected to the connecting piece (54).

6. The miniature circuit breaker as described in claim 1, characterized in that, The short-circuit instantaneous trip system (10) includes: The coil frame (101) is connected to the inside of the outer shell (1) by a support, and the stationary contact (107) is connected to the coil frame (101). The first moving iron core (102) is disposed inside the coil frame (101); The second moving iron core (104) is disposed inside the coil frame (101); Top rod (105), one end of which is connected to the first moving iron core (102), and the other end passes through the inside of the second moving iron core (104) and extends to the outside of the coil frame (101); Spring (103), the spring (103) is sleeved on the outer peripheral surface of the top rod (105), and one end is connected to the first moving iron core (102), and the other end is placed inside the second moving iron core (104); The coil body (106) is sleeved on the outer peripheral surface of the coil frame (101); U-shaped magnetic sheet (108), the U-shaped magnetic sheet (108) is connected to the support, and the stationary contact (107) is connected to the U-shaped magnetic sheet (108).

7. The miniature circuit breaker as described in claim 6, characterized in that: The short-circuit instantaneous tripping system (10) also includes a first terminal block (50), which is connected to the coil body (106).

8. The miniature circuit breaker as described in claim 1, characterized in that: The miniature circuit breaker also includes an arc-extinguishing chamber (7), which is located inside the housing (1), and one end of the short-circuit instantaneous tripping system (10) extends into the arc-extinguishing chamber (7).

9. The miniature circuit breaker as described in claim 8, characterized in that, The arc-extinguishing chamber (7) includes: Red steel cardboard (71); Multiple grid plates (70) are spaced apart inside the red steel cardboard (71). One end of each grid plate (70) is provided with a through groove, and one end of the stationary contact (107) extends into the through groove.

10. The miniature circuit breaker as described in claim 1, characterized in that: The housing (1) is also provided with a wiring clamp (8), and a wiring screw (9) is threaded onto the wiring clamp (8). One end of the short-circuit instantaneous tripping system (10) extends into the wiring clamp (8).

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