A miniature circuit breaker

Abstract

The application relates to the technical field of power distribution equipment, and aims to provide a small circuit breaker, which has a relatively fast short-circuit tripping speed and a relatively large short-circuit breaking capacity index, and comprises a shell and a contact tripping assembly arranged in the shell, wherein the contact tripping assembly comprises an electromagnetic driving assembly and a contact short-circuit tripping rod, the first end of the contact short-circuit tripping rod is rotatably arranged on the inner wall of the shell, and the second end of the contact short-circuit tripping rod can directly press a contact support fixed with a moving contact under the driving of the output end of the electromagnetic driving assembly, so that the moving contact and a static contact are broken. The application solves the problems of the slow short-circuit tripping speed and the small short-circuit breaking capacity index of the small circuit breaker in the prior art.

Description

Technical Field

[0001] This invention relates to the field of power distribution equipment technology, and more specifically to a miniature circuit breaker. Background Technology

[0002] Miniature circuit breakers, also known as micro circuit breakers, are suitable for overload and short-circuit protection of AC 50 / 60Hz lines with rated voltage of 230 / 400V and rated current up to 63A. They can also be used for infrequent switching of lines under normal conditions and are widely used in various places such as industrial, commercial, high-rise and residential buildings.

[0003] Existing miniature circuit breakers have complex structures and numerous components. When short-circuit protection is required, the circuit cannot act directly on the moving contact; it must first pass through other transmission mechanisms to act on the moving contact, causing it to separate from the stationary contact and thus breaking the circuit. This results in slow tripping speed and low short-circuit tripping sensitivity. Furthermore, due to structural size limitations, most miniature circuit breakers have low short-circuit breaking capacity specifications, typically only reaching 4.5kA, 6kA, and 10kA. In summary, existing miniature circuit breakers suffer from slow short-circuit tripping speed and low short-circuit breaking capacity due to design flaws. Summary of the Invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the defects of the existing miniature circuit breakers, which have slow short-circuit tripping speed and small short-circuit breaking capacity, and thus provide a miniature circuit breaker with fast short-circuit tripping speed and large short-circuit breaking capacity.

[0005] To address the aforementioned problems, the present invention provides a miniature circuit breaker, comprising: a housing and a contact tripping assembly disposed within the housing. The contact tripping assembly includes an electromagnetic drive assembly and a contact short-circuit tripping rod. A first end of the contact short-circuit tripping rod is rotatably disposed on the inner wall of the housing. A second end of the contact short-circuit tripping rod, driven by the output end of the electromagnetic drive assembly, can directly press down on a contact bracket fixed to the moving contact, thereby causing the moving contact and the stationary contact to separate.

[0006] Optionally, the housing has an operating handle, and the miniature circuit breaker further includes an operating handle tripping assembly for resetting the operating handle. The operating handle tripping assembly includes an operating handle short-circuit tripping rod, a latch, a tripping latch, and a locking pin. The operating handle short-circuit tripping rod and the latch are rotatably disposed on the inner wall of the housing. One end of the operating handle short-circuit tripping rod is driven to rotate by the contact short-circuit tripping rod, and the other end is adapted to actuate the protruding part of the latch. The latch is provided with a first torsional elastic element, and the direction of the force exerted by the first torsional elastic element on the latch is opposite to the direction in which the operating handle short-circuit tripping rod actuates the protruding part.

[0007] The bottom end of the latch engages with the upper end of the jump buckle and can lock the position of the jump buckle downwards / unlock it upwards. The lower end of the jump buckle is driven by the top rod drive assembly. One end of the locking pin is hinged to the jump buckle, and the hinge axis of the two is limited by the first arc groove. The other end is hinged to the edge of the operating handle.

[0008] Optionally, the push rod drive assembly includes a contact support push rod, which is rotatably disposed on the inner wall of the housing. The hinge joint between the contact support push rod and the jumper is formed with an elongated hole along the length direction of the contact support push rod. A second torsional elastic element is disposed on the contact support push rod. The torque applied by the second torsional elastic element to the contact support push rod drives the jumper to move along the first arcuate groove.

[0009] Optionally, a lever is also provided above the short-circuit trip lever of the contact, and the lever cooperates with one end of the short-circuit trip lever of the operating handle to drive the short-circuit trip lever of the operating handle to rotate.

[0010] Optionally, the operating handle release assembly further includes a linkage pin. The operating handle has a second arc-shaped groove formed thereon. The bottom plane of the second arc-shaped groove gradually rises from bottom to top. The bottom of the second arc-shaped groove contacts the upper end of the linkage pin. The lower end of the linkage pin is fixedly connected to the lever.

[0011] Optionally, the miniature circuit breaker further includes a contact assembly, which includes the moving contact, two stationary contacts, and a contact support. The moving contact is fixedly mounted on the contact support, and the two ends of the moving contact are arranged symmetrically with respect to the axial direction of the contact support. The two stationary contacts cooperate with the two ends of the moving contact.

[0012] Optionally, the miniature circuit breaker further includes two arc-extinguishing mechanisms, which are arranged symmetrically with respect to the contact support and located near both ends of the moving contact.

[0013] Optionally, the miniature circuit breaker further includes an overload protection mechanism, which comprises a bimetallic strip and an overload push rod. One end of the bimetallic strip is connected to the stationary contact, and the other end contacts the overload push rod. A through groove is formed at the end of the overload push rod away from the bimetallic strip, and the through groove is slidably connected to the adjusting lever of the adjusting assembly.

[0014] Optionally, the adjustment assembly further includes an overload adjustment screw and an adjustment elastic element. The adjustment lever is rotatably disposed on the inner wall of the housing. One end of the adjustment elastic element abuts against the inner wall of the housing, and the other end abuts against the protrusion of the adjustment lever. The overload adjustment screw abuts against the upper surface of the protrusion.

[0015] Optionally, the contact tripping assembly further includes a first elastic element, one end of which is connected to the housing and the other end of which is connected to the contact short-circuit tripping rod.

[0016] The present invention has the following advantages:

[0017] 1. The miniature circuit breaker provided by this invention can directly disconnect the moving and stationary contacts by the short-circuit tripping rod of the contact tripping assembly when the current through the miniature circuit breaker is too large, thereby breaking the circuit and protecting electrical components, without the need for other power transmission mechanisms. This contact tripping assembly has a faster breaking speed, shorter response time of each mechanism, short-circuit breaking capacity of over 35kA, and better protection performance when a short circuit occurs.

[0018] 2. The miniature circuit breaker provided by this invention has a locking mechanism in the operating handle tripping assembly where the bottom end of the locking latch cooperates with the upper end of the trip latch. This allows for downward locking of the trip latch to restrict its movement and upward unlocking to allow free movement of the trip latch. Consequently, the operating handle tripping assembly remains stationary when the miniature circuit breaker is closed. Even in the event of vibration, the various parts of the operating handle tripping assembly can be effectively retracted to prevent malfunctions. In the event of short-circuit protection or overload protection, it can respond quickly and cut off the circuit. This operating handle tripping assembly relies on the structure of its components for limiting movement. It has a simple structure, is safe and reliable, and its components work closely together for rapid action.

[0019] 3. The miniature circuit breaker provided by the present invention has a sloped bottom plane of the second arc-shaped groove of the operating handle. When the operating handle moves from the open state to the closed state, it can drive the linkage pin to rotate, thereby driving the lever to rotate, and then driving the operating handle tripping assembly and the contact tripping assembly to reset. The operating handle tripping assembly and the contact tripping assembly can be reset by relying on the special structure of the operating handle to drive the linkage pin to move. The linkage is simple, the operation is convenient, and the reliability is high.

[0020] 4. The miniature circuit breaker provided by the present invention has two stationary contact supports, two stationary contacts and two arc extinguishing mechanisms symmetrically arranged on both sides of the contact support, thereby increasing the arc extinguishing capability and breaking capacity of the circuit breaker.

[0021] 5. The miniature circuit breaker provided by the present invention is equipped with an adjustment component. By changing the position of the adjustment lever through the overload adjustment screw, the displacement of the overload push rod when overload protection occurs can be changed, so that the overload current of the miniature circuit breaker can be adjusted, and precise protection can be provided for different protection current values. Attached Figure Description

[0022] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the closed state of the miniature circuit breaker of the present invention;

[0024] Figure 2 This is a schematic diagram of the tripped state of the miniature circuit breaker of the present invention;

[0025] Figure 3 This is a schematic diagram of the overload tripping state of the miniature circuit breaker of the present invention;

[0026] Figure 4 This is a schematic diagram of the short-circuit tripping state of the miniature circuit breaker of the present invention;

[0027] Figure 5 for Figure 1 Remove the rear view of the casing;

[0028] Figure 6 for Figure 3 Axonometric view.

[0029] Explanation of reference numerals in the attached figures:

[0030] 1-Shell;

[0031] 2-Contact tripping assembly, 201-Electromagnetic drive assembly, 202-Contact short-circuit tripping rod, 203-First elastic element;

[0032] 3-Contact assembly, 301-Moving contact, 302-Contact support, 303-Stationary contact, 304-Stationary contact support, 305-Contact support spring;

[0033] 4-Operating handle, 401-Second arc groove, 402-Third torsional elastic element, 403-Operating part;

[0034] 5-Operating handle release assembly, 501-Operating handle short-circuit release lever, 502-Lock, 5021-Extend, 503-Break, 504-Locking pin, 505-First torsional elastic element, 506-First arc groove, 507-Lever, 508-Linkage pin, 509-Lever pin shaft;

[0035] 6-Push rod drive assembly, 601-Contact support push rod, 6011-Elongated hole, 6012-Protrusion, 6013-Connecting part, 602-Second torsional elastic element;

[0036] 7-Arc extinguishing mechanism, 701-Arc extinguishing cover, 702-Arc extinguishing plate;

[0037] 8-Overload protection component, 801-Bimetallic strip, 802-Overload push rod, 8021-Through groove, 8022-Slide groove;

[0038] 9-Adjustment assembly, 901-Adjustment lever, 902-Overload adjustment screw, 903-Adjustment elastic element, 904-Short circuit adjustment screw. Detailed Implementation

[0039] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for 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. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0041] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" 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; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0042] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0043] like Figures 1 to 6 The diagram shows a preferred embodiment of the miniature circuit breaker provided by the present invention. This miniature circuit breaker can be installed in various places such as industrial, commercial and residential buildings. It has a fast short-circuit tripping speed, a large short-circuit breaking capacity, and a large current limiting coefficient, which can quickly disconnect the circuit when the line is overloaded or short-circuited, thus ensuring power safety.

[0044] The miniature circuit breaker of this embodiment includes: a housing 1, an operating handle 4 disposed on the housing 1, a contact tripping assembly 2 disposed inside the housing 1, and an operating handle tripping assembly 5. The housing 1 is made of insulating material and is composed of two connected parts, forming an internal cavity. An inlet terminal and an outlet terminal are respectively provided at the left and right ends. The operating handle 4 is rotatably connected to an operating handle pin disposed on the housing 1, and the operating part 403 of the operating handle 4 extends to the outside of the housing 1 to facilitate manual operation of the operating part 403, thereby rotating the operating handle 4. A third torsional elastic element 402 is disposed inside the operating handle 4. Specifically, the third torsional elastic element 402 is a torsion spring. The third torsional elastic element 402 is rotatably connected to the operating handle pin, with one end engaging with a groove on the operating handle 4 and the other end engaging with the inner wall of a fixing groove on the housing 1. When the operating handle 4 is in the closed state, the third torsional elastic element 402 is in a compressed state. Therefore, when the miniature circuit breaker changes from the closed state to the open state, the third torsional elastic element 402 can drive the operating handle 4 to rotate.

[0045] The operating handle tripping assembly 5 is used to reset the operating handle 4, and the contact tripping assembly 2 is used to disconnect the moving contact 301 and the stationary contact 303 of the contact assembly 3. Both the operating handle tripping assembly 5 and the contact tripping assembly 2 are disposed within the internal cavity of the housing 1. When a short circuit occurs in the circuit, the operating handle tripping assembly 5 can change the operating handle 4 from the closed state to the open state, and the contact tripping assembly 2 can disconnect the moving contact 301 and the stationary contact 303, thereby breaking the circuit and protecting the safety of downstream electrical equipment.

[0046] Furthermore, the operating handle release assembly 5 includes: an operating handle short-circuit release lever 501, a latch 502, a trip latch 503, and a locking pin 504. The operating handle short-circuit release lever 501 and the latch 502 are rotatably disposed on the inner wall of the housing 1. Specifically, the operating handle short-circuit release lever 501 is rotatably connected to the operating handle short-circuit release lever pin disposed on the housing 1. One end of the operating handle short-circuit release lever 501 is driven to rotate by the contact release assembly 2, and the other end is adapted to actuate the protruding part 5021 of the latch 502. The latch 502 is rotatably connected to the latch pin disposed on the housing 1, and the latch 502 is provided with... The first torsional elastic element 505, preferably a torsion spring in this embodiment, has one end abutting against the inner wall of the housing 1 and the other end abutting against the bottom of the protrusion 5021. The direction of the force exerted by the first torsional elastic element 505 on the latch 502 is opposite to the direction in which the operating handle short-circuit release lever 501 moves the protrusion 5021. That is, when the operating handle short-circuit release lever 501 rotates clockwise to move the protrusion 5021 and cause the latch 502 to rotate counterclockwise, the first torsional elastic element 505 is in a compressed state and has a tendency to drive the latch 502 to rotate clockwise.

[0047] The jump buckle 503 and the locking pin 504 are hinged at one end by a hinge shaft, and the hinge shaft is limited by the first arc groove 506, that is, the hinge shaft can only slide within the first arc groove 506. The other end of the locking pin 504 is also hinged to the edge of the operating handle 4. When the operating handle 4 is rotated, the jump buckle 503 can be driven to slide along the first arc groove 506 through the locking pin 504.

[0048] The lower end of the snap fastener 503 is driven by a push rod drive assembly 6. The drive assembly 6 includes a contact support push rod 601, which is rotatably mounted on the inner wall of the housing 1. Specifically, the contact support push rod 601 is rotatably connected to a push rod pin mounted on the housing 1. An elongated hole 6011 is formed along the length of the contact support push rod 601 at the hinge point between the contact support push rod 601 and the snap fastener 503. The hinge axis between the contact support push rod 601 and the snap fastener 503 can slide within the elongated hole 6011. A second torsional elastic element 602 is also provided on the contact support push rod 601. The second torsional elastic element 602 is preferably a torsion spring and is disposed on both sides of the contact support rod 601. One end of the second torsional elastic element 602 abuts against the protrusion 6012 of the contact support rod 601, and the other end abuts against the connecting part 6013 of the contact support rod 601. One end of the second torsional elastic element 602 on the other side abuts against the inner wall of the fixing groove disposed on the housing 1, and the other end abuts against the connecting part 6013 of the contact support rod 601. The second torsional elastic element 602 can apply torque to the contact support rod 601 and drive the jumper 503 to move along the first arc-shaped groove 506.

[0049] like Figure 1 As shown, the bottom end of the latch 502 engages with the upper end of the trip latch 503 and can lock the position of the trip latch 503 downwards / unlock it upwards. When the operating handle 4 is in the closed state, the bottom end of the latch 502 engages with the upper end of the trip latch 503 to lock the position of the trip latch 503, so that the miniature circuit breaker is in the normal working state of line connection. At this time, the operating handle 4, the locking pin 504, and the trip latch 503 are in the dead position, and the operating handle 4 cannot be driven by the first torsional elastic element 505 to rotate and reset. Figure 4 As shown, when a short circuit or overload protection occurs, the latch 502 rotates counterclockwise, and the bottom end of the latch 502 separates from the top end of the trip latch 503, thereby unlocking the position of the trip latch 503. The second torsional elastic element 602 applies torque to the contact support rod 601, causing it to rotate clockwise. At the same time, it causes the trip latch 503 to move along the first arc groove 506. As a result, the operating handle 4, the locking pin 504, and the trip latch 503 are no longer in the dead position. The operating handle 4 rotates counterclockwise under the drive of the third torsional elastic element 402, that is, the miniature circuit breaker changes from the closed state to the open state.

[0050] The operating handle tripping assembly 5 also includes a lever 507 and a linkage pin 508. The lever 507 is located above the contact short-circuit tripping lever 202. The lever 507 cooperates with one end of the operating handle short-circuit tripping lever 501 to drive the operating handle short-circuit tripping lever 501 to rotate. The upper end of the linkage pin 508 contacts the bottom of the second arc-shaped groove 401 formed on the operating handle 4, and the lower end of the linkage pin 508 is fixedly connected to the lever 507. The lever 507 is rotatably connected to the lever pin 509. The bottom plane of the second arc-shaped groove 401 gradually rises from bottom to top. When the operating handle 4 is rotated, the second arc-shaped groove 401 will drive the linkage pin 508 to rotate. Since the lever 507 is fixedly connected to the linkage pin 508, the lever 507 will rotate around the lever pin 509. The lever 507 also cooperates with the end of the operating handle short-circuit release lever 501 away from the lock 502. When the lever 507 rotates, it will drive the operating handle short-circuit release lever 501 to rotate. Furthermore, a fourth torsional elastic element is provided inside the lever 507.

[0051] The contact tripping assembly 2 includes: an electromagnetic drive assembly 201, a contact short-circuit tripping lever 202, and a first elastic element 203. The contact short-circuit tripping lever 202 is disposed below the lever 507, with the bottom surface of the lever 507 abutting against the top surface of the contact short-circuit tripping lever 202. The first end of the contact short-circuit tripping lever 202 is rotatably disposed on the inner wall of the housing 1, and the second end cooperates with the contact support 302. The output end of the electromagnetic drive assembly 201 can press down the contact short-circuit tripping lever 202, and the second end of the contact short-circuit tripping lever 202 cooperating with the contact support 302 will press down the contact support 302.

[0052] Specifically, the electromagnetic drive assembly 201 includes a coil, a moving iron core, a stationary iron core, a return spring, and a short-circuit push rod. When the miniature circuit breaker is working normally, the current flowing through the coil is small. Although a magnetic field is generated, the attraction between the moving iron core and the stationary iron core is insufficient to overcome the elastic force of the return spring. Therefore, the moving iron core cannot push the short-circuit push rod down to press the short-circuit trip rod 202 of the contact and make it rotate. When the miniature circuit breaker is performing short-circuit protection, the current flowing through the coil is large. The attraction between the moving iron core and the stationary iron core is greater than the elastic force of the return spring. The moving iron core moves downward and drives the short-circuit push rod downward. The short-circuit push rod then presses down the short-circuit trip rod 202 of the contact, causing the short-circuit trip rod 202 of the contact to rotate and press down the contact support 302.

[0053] The contact assembly 3 includes: a moving contact 301, two stationary contacts 303, a contact support 302, two stationary contact supports 304, and a contact support spring 305. The moving contact 301 is mounted on the contact support 302, and its two ends are symmetrically arranged with respect to the axial direction of the contact support 302. A contact support spring 305 is also disposed inside the contact support 302, with one end of the spring fixedly connected to the moving contact 301. Two stationary contact supports 304 are symmetrically arranged on both sides of the contact support 302, and stationary contacts 303 are respectively mounted on the two stationary contact supports 304. The two stationary contacts 303 cooperate with the two ends of the moving contact 301.

[0054] Two arc-extinguishing mechanisms 7 are symmetrically arranged at the bottom of the two stationary contact supports 304 relative to the axial direction of the contact support 302, and the two arc-extinguishing mechanisms 7 are located near both ends of the moving contact 301. Each arc-extinguishing mechanism 7 includes an arc-extinguishing cover 701 and an arc-extinguishing plate 702. The arc-extinguishing cover 701 and the contact support 302 are spaced apart, and the arc-extinguishing plate 702 is disposed on the surface of the area between the arc-extinguishing cover 701 and the contact support 302. The arc-extinguishing mechanisms 7 can extinguish the arc generated during overload or short circuit, preventing the high-temperature arc from burning internal components. By setting two arc-extinguishing mechanisms 7, the arc-extinguishing capability of the miniature circuit breaker can be improved.

[0055] The overload protection component 8 includes a bimetallic strip 801 and an overload push rod 802. One end of the bimetallic strip 801 is connected to the stationary contact 303, and the other end is in contact with the overload push rod 802. The overload push rod 802 has a sliding groove 8022, which is slidably connected to a connecting shaft fixed on the housing 1. The connecting shaft fixes the position of the overload push rod 802. The end of the overload push rod 802 away from the bimetallic strip 801 has a through groove 8021, which is slidably connected to the adjusting lever 901 of the adjusting component 9. The overload push rod 802 is also in contact with the latch 502.

[0056] The adjustment assembly includes: an adjustment lever 901, an overload adjustment screw 902, an adjustment elastic element 903, and a short-circuit adjustment screw 904. The adjustment lever 901 is rotatably mounted on the inner wall of the housing 1. One end of the adjustment elastic element 903 abuts against the inner wall of the housing 1, and the other end abuts against the protrusion 9011 of the adjustment lever 901. The overload adjustment screw 902 abuts against the upper surface of the protrusion 9011. By adjusting the position of the overload adjustment screw 902, the adjustment elastic element 903 can drive the adjustment lever 901 to rotate. Since the through groove 8021 of the overload push rod 802 is slidably connected to the adjustment lever 901, the rotation of the adjustment lever 901 will drive the overload push rod 802 to rotate, which can change the displacement of the overload push rod 802 when overload protection occurs, and can achieve precise overload protection for different current protection values. The short-circuit adjusting screw 904 is located at the upper end of the electromagnetic drive assembly 201 and abuts against the moving iron core. By adjusting the short-circuit adjusting screw 904, the distance between the moving iron core and the stationary iron core can be changed. Thus, when performing short-circuit protection, the displacement of the moving iron core will change with the change of the short-circuit adjusting screw 904. Similarly, it can provide precise short-circuit protection for different protection current values.

[0057] The working process of the miniature circuit breaker in this embodiment is described below:

[0058] The miniature circuit breaker provided in this embodiment has two operating states: closing and opening. In the closing state, current is input from the incoming terminal and output from the outgoing terminal to the subsequent electrical equipment, and this current is sufficient for the normal operation of the electrical equipment. Furthermore, as... Figure 1 As shown, when in the closed state, the operating handle 4 is located at the right end inside the housing 1. The latch 502 in the operating handle tripping assembly 5 locks the tripping latch 503 downward, preventing it from moving. The moving contact 301 of the contact assembly 3 contacts the stationary contact 303, allowing current to be transmitted from the inlet to the outlet. The electromagnetic drive assembly 201 in the contact tripping assembly 2 will not press down the contact short-circuit tripping rod 202, and the contact short-circuit tripping rod 202 will not rotate. The bimetallic strip 801 in the overload protection assembly 8 will not deform, and the overload push rod 802 will be in the initial position.

[0059] When a miniature circuit breaker is in the open state, the line is no longer connected, and subsequent electrical equipment cannot continue to be used. The transition from the closed state to the open state can be achieved through three methods: manual operation, short-circuit protection, and overload protection.

[0060] Manual operation of a miniature circuit breaker from the closed to the open state is mostly due to the need to replace or repair downstream electrical equipment. Opening the miniature circuit breaker disconnects the power supply to ensure personal safety. Figure 2As shown, the operation process is as follows: the operator turns the operating handle 4 to rotate it from the right end to the left end. The locking pin 504 drives the jumper 503 to slide in the first arc groove 506. The contact support rod 601 rotates clockwise. The connecting part 6013 contacts the contact bracket 302 and presses it down. The contact bracket 302 moves downward, thereby separating the moving contact 301 and the stationary contact 303, and the circuit is disconnected.

[0061] When the tripping of a miniature circuit breaker is due to short-circuit protection, such as Figure 4 As shown, its working process is as follows: When a short circuit occurs, the current through the coil is large, and the attraction between the stationary iron core and the moving iron core is greater than the force of the return spring, causing the short-circuit push rod to move downward. This causes the short-circuit push rod to press down on the contact short-circuit trip lever 202. One end of the contact short-circuit trip lever 202 rotates and presses down on the contact bracket 302, causing the moving contact 301 and the stationary contact 303 to separate, thus breaking the circuit. Simultaneously, as the contact short-circuit trip lever 202 rotates, it no longer limits the movement of the lever 507, and the lever 507 moves to the fourth position. Driven by the torsion elastic element, the circuit breaker rotates, causing the short-circuit trip lever 501 of the operating handle to rotate clockwise. Consequently, the end of the short-circuit trip lever 501 away from the lever 507 drives the latch 502 to rotate counterclockwise. When the latch 502 rotates, the trip latch 503 is unlocked. The trip latch 503 can slide in the first arc groove 506 under the drive of the push rod drive assembly 6. Then, the operating handle 4 rotates and resets under the drive of the third torsion elastic element 402, and the circuit breaker changes from the closed state to the open state.

[0062] When the tripping of a miniature circuit breaker is due to overload protection, such as Figure 3 As shown, its working process is as follows: When the line is overloaded, the end of the bimetallic strip 801 that contacts the overload push rod 802 is heated and deformed, which will drive the overload push rod 802 to slide upward. During the sliding process, the overload push rod 802 will push the latch 502 to rotate counterclockwise, thereby unlocking the trip latch 503 and allowing it to slide in the first arc groove 506 under the drive of the push rod drive assembly 6. The second torsional elastic element 602 will drive the contact support push rod 601 to rotate clockwise, thereby pressing the contact bracket 302 down, causing the moving contact 301 and the stationary contact 303 to separate, and the line is disconnected. At the same time, the operating handle 4 rotates under the drive of the third torsional elastic element 402, and the circuit breaker changes from the closed state to the open state.

[0063] When the miniature circuit breaker changes from the open to the closed state, simply turn the operating handle 4 from the left to the right. During the rotation of the operating handle 4, the bottom plane of the second arc-shaped groove 401 will drive the linkage pin 508 to rotate. The rotation of the linkage pin 508 will drive the lever 507 to rotate, thereby compressing the internal fourth torsional elastic element. At the same time, the lever 507 will drive the operating handle short-circuit trip lever 501 to rotate counterclockwise. The first torsional elastic element 505 will drive the latch 502 to rotate clockwise. Simultaneously, when the operating handle 4 is rotated, it will also cause the trip latch 503 to slide from the right end of the first arc-shaped groove 506 to the left. At the end, the latch 502 locks the position of the jump latch 503. As the jump latch 503 slides from the right end to the left end of the first arc groove 506, it drives the push rod drive assembly 6 to rotate counterclockwise. When the lever 507 rotates, the bottom of the lever 507 no longer restricts the contact short-circuit trip lever 202. The contact short-circuit trip lever 202 rotates clockwise under the elastic force of the first elastic element 203. The contact support 302 is no longer pressed down by the contact short-circuit trip lever 202 or the contact support push rod 601. It can be reset by the contact support spring 305. The moving contact 301 and the stationary contact 303 contact again, connecting the circuit.

[0064] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A miniature circuit breaker, comprising: The housing (1) and the contact tripping assembly (2) disposed within the housing (1) are characterized in that, The contact tripping assembly (2) includes an electromagnetic drive assembly (201) and a contact short-circuit tripping rod (202). The first end of the contact short-circuit tripping rod (202) is rotatably disposed on the inner wall of the housing (1). The second end of the contact short-circuit tripping rod (202) can be driven by the output end of the electromagnetic drive assembly (201) to directly press down on the contact bracket (302) fixed to the moving contact (301), so that the moving contact (301) and the stationary contact (303) are separated. The housing (1) has an operating handle (4), and the miniature circuit breaker also includes an operating handle trip assembly (5) for resetting the operating handle (4). The operating handle trip assembly (5) includes an operating handle short-circuit trip rod (501), a latch (502), a trip latch (503), and a locking pin (504). The operating handle short-circuit trip rod (501) and the latch (502) are rotatably disposed on the inner wall of the housing (1). One end of the operating handle short-circuit trip rod (501) is driven to rotate by the contact short-circuit trip rod (202), and the other end is adapted to pry open the protrusion (5021) of the latch (502). The latch (502) is provided with a first torsional elastic element (505). The direction of the force exerted by the first torsional elastic element (505) on the latch (502) is opposite to the direction in which the operating handle short-circuit trip rod (501) pries open the protrusion (5021). The bottom end of the latch (502) engages with the upper end of the jumper (503) and can lock the position of the jumper (503) downwards / unlock it upwards. The lower end of the jumper (503) is driven by the top rod drive assembly (6). One end of the locking pin (504) is hinged to the jumper (503), and the hinge axis of the two is limited by the first arc groove (506). The other end is hinged to the edge of the operating handle (4). A lever (507) is also provided above the short-circuit trip lever (202) of the contact. The lever (507) cooperates with one end of the short-circuit trip lever (501) of the operating handle, thereby driving the short-circuit trip lever (501) of the operating handle to rotate. The operating handle release assembly also includes a linkage pin (508). The operating handle (4) has a second arc-shaped groove (401) formed on it. The bottom plane of the second arc-shaped groove (401) gradually rises from bottom to top. The bottom of the second arc-shaped groove (401) contacts the upper end of the linkage pin (508). The lower end of the linkage pin (508) is fixedly connected to the lever (507).

2. The miniature circuit breaker according to claim 1, characterized in that, The push rod drive assembly (6) includes a contact support push rod (601), which is rotatably disposed on the inner wall of the housing (1). The contact support push rod (601) and the jump buckle (503) are hinged together with an elongated hole (6011) formed along the length direction of the contact support push rod (601). A second torsional elastic element (602) is disposed on the contact support push rod (601). The torque applied by the second torsional elastic element (602) to the contact support push rod (601) drives the jump buckle (503) to move along the first arcuate groove (506).

3. The miniature circuit breaker according to claim 1, characterized in that, It also includes a contact assembly (3), which includes the moving contact (301), two stationary contacts (303) and the contact support (302). The moving contact (301) is disposed on the contact support (302) and the two ends of the moving contact (301) are arranged symmetrically with respect to the axial direction of the contact support (302). The two stationary contacts (303) cooperate with the two ends of the moving contact (301).

4. The miniature circuit breaker according to claim 3, characterized in that, It also includes two arc-extinguishing mechanisms (7), which are arranged symmetrically with respect to the contact support (302) and are located near the two ends of the moving contact (301).

5. The miniature circuit breaker according to claim 3, characterized in that, It also includes an overload protection mechanism (8), which includes a bimetallic strip (801) and an overload push rod (802). One end of the bimetallic strip (801) is connected to the stationary contact (303), and the other end is in contact with the overload push rod (802). The end of the overload push rod (802) away from the bimetallic strip (801) is provided with a through groove (8021), and the through groove (8021) is slidably connected to the adjusting lever (901) of the adjusting assembly (9).

6. The miniature circuit breaker according to claim 5, characterized in that, The adjustment assembly (9) further includes an overload adjustment screw (902) and an adjustment elastic element (903). The adjustment lever (901) is rotatably disposed on the inner wall of the housing (1). One end of the adjustment elastic element (903) abuts against the inner wall of the housing (1), and the other end abuts against the protrusion (9011) of the adjustment lever (901). The overload adjustment screw (902) abuts against the upper surface of the protrusion (9011).

7. The miniature circuit breaker according to claim 1, characterized in that, The contact tripping assembly (2) further includes a first elastic element (203), one end of which is connected to the housing (1) and the other end is connected to the contact short-circuit tripping rod (202).

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