A current limiting mechanism and a circuit breaker

Abstract

This application provides a current-limiting mechanism and a circuit breaker, relating to the field of switch technology, for improving the installation efficiency of the current-limiting mechanism and shortening the production cycle of the circuit breaker. The current-limiting mechanism includes a connecting plate, a bimetallic strip, and a current-limiting element. The connecting plate is electrically connected to an external device. The bimetallic strip is electrically connected to the connecting plate and has a first surface and a second surface disposed opposite to each other. The current-limiting element has a connecting portion, a mounting portion, and a folding structure sequentially connected. The connecting portion is located on the side of the bimetallic strip near the first or second surface, and the connecting end of the bimetallic strip is located in the connecting portion. The mounting portion is located on the side of the bimetallic strip near the second surface, and the folding structure is located on the side of the bimetallic strip. The circuit breaker includes a housing, a moving contact, a stationary contact, a tripping mechanism, and a current-limiting mechanism. The moving contact is electrically connected to the current-limiting mechanism. The stationary contact is in contact with or out of contact with the moving contact. The tripping mechanism is located at the driving end of the current-limiting mechanism and is used to drive the tripping mechanism to trip.

Description

Technical Field

[0001] This application relates to the field of switch technology, specifically to a current limiting mechanism and a circuit breaker. Background Technology

[0002] The breaking capacity of a circuit breaker is generally matched to the transformer's ability to withstand abnormal conditions such as short circuits or overloads. The larger the abnormal current, the greater the electrodynamic force and heat generated, and the more severe the test on the transformer and circuit breaker.

[0003] For some high-current circuit breakers, abnormal currents are often quickly interrupted by increasing the electrodynamic repulsion between contacts and enhancing the ability to extinguish arcs. However, for some low-current circuit breakers, their ability to withstand large abnormal currents is relatively weak, and the electrodynamic force and heat of the abnormal current can cause significant damage to the circuit breaker.

[0004] Therefore, people often reduce the abnormal current passing through the circuit breaker by increasing the resistance of the current limiting mechanism in the circuit breaker.

[0005] However, the current limiting mechanism in the existing technology is not convenient for the installation and operation of bimetallic strips, the installation efficiency of the current limiting mechanism is low, and the production cycle of the circuit breaker is long. Utility Model Content

[0006] This application provides a current limiting mechanism and a circuit breaker to improve the installation efficiency of the current limiting mechanism and further shorten the production cycle of the circuit breaker.

[0007] To achieve the above objectives, in a first aspect, this application provides a current-limiting mechanism, which includes a connecting plate, a bimetallic strip, and a current-limiting element. The connecting plate is used for electrical connection to an external device. The bimetallic strip is electrically connected to the connecting plate and has a first surface and a second surface disposed opposite to each other. The current-limiting element has a connecting portion, a mounting portion, and a folding structure sequentially connected. The connecting portion is disposed on the side of the bimetallic strip near the first surface or the second surface, and the connecting end of the bimetallic strip is disposed in the connecting portion. The mounting portion is located on the side of the bimetallic strip near the second surface, and the folding structure is disposed on the side of the bimetallic strip, the folding structure being used for electrical connection to the moving contact of a circuit breaker.

[0008] When adopting the above technical solution, the current-limiting mechanism includes a connecting plate, a bimetallic strip, and a current-limiting element. The current-limiting element has a sequentially connected connecting part, a mounting part, and a folding structure. The folding structure results in a longer overall length and higher resistance of the current-limiting element, which increases the impedance of the conductive line. In the event of an overload or short circuit in the circuit containing the circuit breaker, the current flowing through the circuit breaker can be reduced. This ensures that the circuit breaker can withstand the electrodynamic repulsion and heat of the abnormal current during the circuit breaker's tripping process, reducing damage to the transformer and conductive line, extending the service life of the circuit breaker, and ensuring the safety of the transformer and conductive line.

[0009] Furthermore, the folding structure is located on the side of the bimetallic strip, and the mounting part is located on the side of the bimetallic strip closer to the second surface. When connecting the bimetallic strip to the connecting part, the operation can be performed from the side of the bimetallic strip closer to the first surface. The folding structure is less likely to interfere with the connection between the bimetallic strip and the connecting part, facilitating the installation of the bimetallic strip and improving the installation efficiency of the current limiting mechanism. Consequently, it can shorten the production cycle of the circuit breaker.

[0010] In one possible implementation, the folded structure has a plurality of first folded segments connected in sequence, which are stacked along the length of the bimetallic sheet.

[0011] When the above technical solution is adopted, the arrangement of multiple first folding segments can effectively extend the length of the current limiting element and increase the impedance of the current limiting mechanism. The multiple first folding segments are stacked along the length direction of the bimetallic strip, which can compress the longer current limiting element into a limited space, thus helping to reduce the space occupied by the current limiting mechanism.

[0012] In one possible implementation, the boundary line between every two connected first folded segments is perpendicular to the length direction of the bimetallic sheet and the direction from the first surface to the second surface.

[0013] When adopting the above technical solution, multiple first folding segments are parallel, and the side of the multiple first folding segments away from the connecting part can be coplanar to reduce the space occupied by the folding structure. Furthermore, while ensuring the length of the current limiting component, the space occupied by the current limiting mechanism can be reduced. At the same time, the current limiting component has a neat appearance and an aesthetically pleasing shape.

[0014] In one possible implementation, the current-limiting element further includes an extension located on the side of the bimetallic strip closer to the first surface. One end of the extension is connected to the end of the folded structure furthest from the mounting portion, and the other end of the extension is used for electrical connection with the moving contact.

[0015] When adopting the above technical solution, the extension section can further increase the length of the current-limiting element and the impedance of the current-limiting mechanism. In the event of overload or short circuit in the circuit containing the circuit breaker, the current flowing through the circuit breaker can be further reduced. This ensures that during the circuit breaker's tripping process, it can withstand the electrodynamic repulsion and heat of the abnormal current, reducing damage to the transformer and conductive lines, and guaranteeing the safety of the transformer and conductive lines.

[0016] In one possible implementation, the extension is an L-shaped structure.

[0017] When the above technical solution is adopted, the length of the current limiting element can be further increased, and the impedance of the current limiting mechanism can be increased.

[0018] At the same time, it can enrich the structure of the extension section, increase the number of structural forms of the flow limiting component, and facilitate the selection and setting according to the actual situation.

[0019] In one possible implementation, the extension includes a plurality of sequentially connected second folded segments, which are stacked along the length of the bimetallic sheet.

[0020] When employing the above technical solution, the multiple second folding sections result in a longer overall length and higher resistance of the current-limiting element, thereby increasing the impedance of the conductive lines. In the event of overload or short circuit in the circuit containing the circuit breaker, the current flowing through the circuit breaker can be reduced. This ensures that the circuit breaker can withstand the electrodynamic repulsion and heat from abnormal currents during the breaking process, reducing damage to the transformer and conductive lines and guaranteeing their safety.

[0021] Multiple second folded segments are stacked along the length of the bimetallic strip, which can compress a longer flow-limiting element into a limited space, thus helping to reduce the space occupied by the flow-limiting mechanism.

[0022] In one possible implementation, the boundary line between every two connected second fold segments is parallel to the direction from the first surface to the second surface.

[0023] When adopting the above technical solution, multiple second folding segments are parallel, and the sides of the multiple second folding segments away from the connecting part can be coplanar to reduce the space occupied by the multiple second folding segments. Furthermore, while ensuring the length of the current-limiting component, the space occupied by the current-limiting mechanism can be reduced. At the same time, the current-limiting component has a neat appearance and an aesthetically pleasing design.

[0024] In one possible implementation, the current limiter is an integral structure.

[0025] When the above technical solution is adopted, the connecting part, mounting part, folding structure, and extension part are integrally formed. In this way, not only can the stress concentration problem caused by other connection methods such as bolts or welding be avoided, but higher dimensional accuracy and consistency can also be guaranteed, thereby improving the structural strength of the flow restrictor.

[0026] Moreover, the elimination of machining requirements for the current-limiting components reduces material usage and avoids waste. Furthermore, the integrated structure reduces connection points, lowering the risk of failures due to loose connections, corrosion, or fatigue, and improving fatigue resistance. Additionally, it reduces the number of parts and assembly steps for the current-limiting components, simplifying the operation process, improving the installation efficiency of the current-limiting mechanism, and further shortening the circuit breaker's production cycle.

[0027] In one possible implementation, the current limiter is an iron-chromium-aluminum alloy current limiter, a stainless steel current limiter, or a constantan current limiter.

[0028] When adopting the above technical solution, the materials of the current limiting component can be diversified, and the materials of the current limiting component are diverse, which makes it easy to select and set according to the actual situation.

[0029] Secondly, this application provides a circuit breaker, including a housing, a moving contact, a stationary contact, a tripping mechanism, and a current-limiting mechanism as described in any possible implementation of the first aspect. The current-limiting mechanism is disposed in the housing, and the moving contact is rotatably disposed in the housing and electrically connected to the current-limiting mechanism. The stationary contact is disposed in the housing and is used to contact or disengage from the moving contact. The tripping mechanism is disposed in the housing and is located at the drive end of the current-limiting mechanism, and the current-limiting mechanism is used to drive the tripping mechanism to trip.

[0030] The beneficial effects of the circuit breaker described in the second aspect can be referred to the beneficial effects of the current limiting mechanism described in the first aspect, and will not be repeated here. Attached Figure Description

[0031] Figure 1 Schematic diagram of the current limiting mechanism and moving contact provided in the embodiments of this application Figure 1 .

[0032] Figure 2 Schematic diagram of the current limiting mechanism and moving contact provided in the embodiments of this application Figure 2 .

[0033] Figure 3 Schematic diagram of the current limiting device provided in the embodiments of this application Figure 1 .

[0034] Figure 4 Schematic diagram of the current limiting device provided in the embodiments of this application Figure 2 .

[0035] Explanation of reference numerals in the attached figures:

[0036] 1-Connecting plate, 2-Bimetallic strip, 3-Current limiting component, 31-Connecting part, 32-Mounting part, 33-Folding structure

[0037] 331 - First fold section, 34 - Extension, 10 - Moving contact. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0039] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein in the specification of the application is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims and drawings of this application are intended to cover non-exclusive inclusion.

[0040] The term "embodiment" as used herein means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of the phrase "embodiment" in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0041] The directional terms appearing in the following description refer to the directions shown in the figures and are not intended to limit the specific structure of this application. For example, in the description of this application, the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the figures. They 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. Therefore, they should not be construed as limitations on this application.

[0042] Furthermore, the terms "first," "second," etc., in the specification and claims of this application or in the aforementioned drawings are used to distinguish different objects rather than to describe a specific order, and may explicitly or implicitly include one or more of the features.

[0043] In the description of this application, unless otherwise stated, "multiple" means two or more (including two), and similarly, "multiple groups" means two or more (including two groups).

[0044] A circuit breaker is an electrical protection device that quickly disconnects a circuit when an abnormal condition such as an overload or short circuit is detected, preventing equipment damage, fire, or electric shock hazards. The larger the abnormal current, the greater the electrodynamic force and heat generated, and the more severe the test on the transformer and circuit breaker.

[0045] For some high-current circuit breakers, abnormal currents are often quickly interrupted by increasing the electrodynamic repulsion between contacts and enhancing the ability to extinguish arcs.

[0046] However, for some circuit breakers with small current specifications (such as 6A-32A), their ability to withstand large abnormal currents is weak, and the electrodynamic force and heat of the abnormal current can cause significant damage to the circuit breaker.

[0047] Therefore, people often reduce the abnormal current passing through the circuit breaker by increasing the resistance of the current-limiting mechanism. In this way, when a serious overload or short-circuit fault occurs in the line, by increasing the impedance of the conductive line, which is much greater than the impedance of the transformer, the actual abnormal current will not be too large, reducing the damage to the transformer and conductive line, and ensuring the safety of the transformer and conductive line. This is more suitable for circuit breakers with small current ratings.

[0048] In existing current-limiting mechanisms, the connection part for connecting to the bimetallic strip is generally located between the mounting part and the folding structure. During actual installation, the folding structure interferes with the connection between the bimetallic strip and the connection part, hindering the installation of the bimetallic strip, resulting in low installation efficiency and a longer production cycle for the circuit breaker.

[0049] In view of the problems existing in the prior art, firstly, the present application provides a circuit breaker, the two ends of which can be connected to a transformer and a load respectively by wires.

[0050] refer to Figure 1 , Figure 2 As shown, the circuit breaker provided in this application embodiment includes a housing, a moving contact 10, a stationary contact, a tripping mechanism, and a current limiting mechanism.

[0051] The moving contact 10 is rotatably mounted on the housing. The specific structure of the moving contact 10 and the manner in which the moving contact 10 is rotatably mounted on the housing are not specifically limited here, but shall be subject to the actual situation.

[0052] The stationary contact is located on the housing. In fact, the stationary contact can be fixed to the housing by welding, bonding or other methods, or by using screws to fix the stationary contact to the housing.

[0053] The stationary contact is used to make contact with or disengage from the moving contact 10. When the moving contact 10 rotates relative to the housing, it has two positions relative to the stationary contact: a contact position and a disengaged position. When the moving contact 10 is in the contact position, it is in contact with the stationary contact, the circuit current is connected, and the circuit breaker is in the closed state. When the moving contact 10 is in the disengaged position, it is disconnected from the stationary contact, the circuit current is interrupted, and the circuit breaker is in the open state.

[0054] The current limiting mechanism is located in the housing, and the moving contact 10 is electrically connected to the current limiting mechanism. The tripping mechanism is located at the drive end of the current limiting mechanism, and the current limiting mechanism is used to drive the tripping mechanism to trip.

[0055] When an overload or short circuit occurs in the circuit where the circuit breaker is located, the current limiting mechanism can drive the tripping mechanism to trip, thereby switching the moving contact 10 from the contact position to the disengagement position, causing the moving contact 10 and the stationary contact to disengage, disconnecting the current in the circuit where the circuit breaker is located, and ensuring electrical safety.

[0056] In the embodiments provided in this application, the moving contact 10, the stationary contact, the current limiting mechanism, and the tripping mechanism are all disposed on the housing. In fact, the moving contact 10, the stationary contact, the current limiting mechanism, and the tripping mechanism are all installed inside the housing.

[0057] The housing can accommodate the moving contact 10, stationary contact, current limiting mechanism, and tripping mechanism, providing a stable space for them to ensure normal operation without external interference. Simultaneously, the housing provides positioning and support for the moving contact 10, stationary contact, current limiting mechanism, and tripping mechanism, preventing displacement or damage to components within the housing during operation. The housing can also withstand a certain amount of external pressure, protecting the moving contact 10, stationary contact, current limiting mechanism, and tripping mechanism from damage. Furthermore, the housing provides protection, preventing moisture, dust, dirt, and other impurities from entering the housing, thus avoiding corrosion or damage to the moving contact 10, stationary contact, current limiting mechanism, and tripping mechanism installed inside the housing.

[0058] like Figure 1 and Figure 2 As shown, the current limiting mechanism provided in this application embodiment includes a connecting plate 1, a bimetallic strip 2, and a current limiting element 3, wherein the connecting plate 1 is used for electrical connection with an external device.

[0059] In practice, the connecting plate 1 can be fixedly installed on the base of the housing by welding, riveting, or other methods. Alternatively, screws can be used to fix the connecting plate 1 to the housing. The method of installing the connecting plate 1 on the housing is not limited here; the specific method depends on the actual situation.

[0060] The connecting plate 1 can have a straight plate structure, as shown in the embodiments provided in this application, such as... Figure 1 and Figure 2 As shown, the connecting plate 1 has an L-shaped structure. The connecting plate 1 is made of a conductive material and can be directly or indirectly connected to external devices such as loads.

[0061] The bimetallic strip 2 is electrically connected to the connecting plate 1. The bimetallic strip 2 can be a rectangular sheet structure. Along the length of the bimetallic strip 2, it has a connecting end and a driving end that are arranged opposite each other. The connecting end is connected to the current limiting element 3, thereby fixing the bimetallic strip 2 to the current limiting element 3. The tripping structure is located at the driving end, which is used to drive the tripping mechanism to trip.

[0062] When the current flowing through the bimetallic strip 2 is large, the temperature of the bimetallic strip 2 will rise. Under this condition, the bimetallic strip 2 will bend and deform, and the drive end will be able to drive the tripping mechanism to trip.

[0063] The bimetallic strip 2 has a first surface and a second surface disposed opposite to each other. In a specific implementation, the two larger surfaces of the bimetallic strip 2 are the first surface and the second surface, respectively.

[0064] When an abnormal situation such as overload or short circuit occurs in the circuit where the circuit breaker is located, the current flowing through the bimetallic strip 2 is large. The driving end of the bimetallic strip 2 will bend towards the first surface or the second surface relative to the connecting end, so as to drive the tripping mechanism to trip.

[0065] Please combine Figure 3 and Figure 4 As shown, the flow restrictor 3 has a connecting part 31, a mounting part 32, and a folding structure 33 connected in sequence. That is, one end of the connecting part 31 is connected to one end of the mounting part 32, and the other end of the mounting part 32 is connected to one end of the folding structure 33.

[0066] In actual operation, the connecting part 31 can be connected to the mounting part 32 by welding, snap-fitting, riveting, etc., but it is not limited to these methods.

[0067] The folding structure 33 can be connected to the mounting part 32 by welding, snap-fitting, riveting, etc. This is just an example and is not intended to be a specific limitation.

[0068] The mounting part 32 is used to connect with the housing, thereby installing the flow restrictor 3 on the housing. Specifically, the mounting part 32 can be fixedly installed on the base of the housing by means of welding, snap-fitting, riveting, or other methods.

[0069] The connecting part 31 is disposed on the side of the bimetallic sheet 2 near the first surface or the second surface. The connecting part 31 can be located on the side of the bimetallic sheet 2 near the first surface or on the side of the bimetallic sheet 2 near the second surface.

[0070] The connecting end of the bimetallic strip 2 is located at the connecting part 31. In specific implementations, the connecting end and the connecting part 31 can be connected together by welding, snap-fitting, riveting, or other methods. Of course, the actual implementation is not limited to these methods.

[0071] The mounting portion 32 is located on the side of the bimetallic strip 2 closest to the second surface. At this time, when the connecting portion 31 is located on the side of the bimetallic strip 2 closest to the first surface, the connecting portion 31 and the mounting portion 32 are located on opposite sides of the bimetallic strip 2. When the connecting portion 31 is located on the side of the bimetallic strip 2 closest to the second surface, the connecting portion 31 and the mounting portion 32 are located on the same side of the bimetallic strip 2.

[0072] A folding structure 33 is disposed on the side of the bimetallic strip 2, and the folding structure 33 is used for electrical connection with the moving contact 10 of the circuit breaker. One end of the folding structure 33 is connected to the mounting part 32, and the other end of the folding structure 33 is electrically connected to the moving contact 10.

[0073] It is understood that, in the embodiments provided in this application, the folded structure 33 may refer to a structure formed by bending and stacking long strips of material in a specific manner.

[0074] This design results in a longer overall length and higher resistance for the current-limiting element 3, increasing the impedance of the conductive lines. In the event of overload or short circuit in the circuit containing the circuit breaker, this reduces the current flowing through the circuit breaker. This ensures that the circuit breaker can withstand the electrodynamic repulsion and heat from abnormal currents during the breaking process, reducing damage to the transformer and conductive lines and guaranteeing their safety.

[0075] In the embodiments provided in this application, the folding structure 33 is located on the side of the bimetallic sheet 2, and the mounting part 32 is located on the side of the bimetallic sheet 2 near the second surface.

[0076] When connecting the bimetallic strip 2 to the connecting part 31, the operation can be performed from the side of the bimetallic strip 2 closest to the first surface. The folding structure 33 is less likely to interfere with the connection between the bimetallic strip 2 and the connecting part 31, which facilitates the installation operation of the bimetallic strip 2, improves the installation efficiency of the current limiting mechanism, and correspondingly shortens the production cycle of the circuit breaker.

[0077] It should be noted that the folding structure 33 is located on the side of the bimetallic sheet 2, meaning that the folding structure 33 is located on the side of the bimetallic sheet 2 closest to the side.

[0078] In practice, the moving contact 10, the current-limiting element 3, and the bimetallic strip 2 are all electrically connected. In a specific implementation, the bimetallic strip 2 can be electrically connected to the connecting plate 1 via a flexible wire. When the current in the bimetallic strip 2 increases and its temperature rises, causing it to bend and deform, the position of the end of the flexible wire connected to the bimetallic strip 2 will change. The flexible wire design minimizes resistance to the deformation of the bimetallic strip 2, ensuring that in the event of an abnormality in the circuit where the circuit breaker is located, the driving end of the bimetallic strip 2 can drive the tripping mechanism to trip when it bends and deforms. The folding structure 33 can also be electrically connected to the moving contact 10 via a flexible wire; however, the implementation is not limited to this.

[0079] The flexible conductor can be made of copper, copper alloy, or aluminum, etc. The length of the flexible conductor depends on the actual situation and is not specifically limited here.

[0080] Please refer to Figure 4 As shown, the folding structure 33 has a plurality of first folding segments 331 connected in sequence, and the plurality of first folding segments 331 are stacked along the length direction of the bimetallic sheet 2.

[0081] At this point, the arrangement of multiple first folded segments 331 can effectively extend the length of the current limiting element 3 and increase the impedance of the current limiting mechanism. The multiple first folded segments 331 are stacked along the length direction of the bimetallic strip 2, which can compress the longer current limiting element 3 into a limited space, thus helping to reduce the space occupied by the current limiting mechanism.

[0082] In practice, the number of first folding segments 331 can be three, four, five or more, and multiple first folding segments 331 are connected end to end in sequence.

[0083] Taking a case where there are three first folding segments 331 as an example, the specific structure of the flow restrictor 3 will be explained. The three first folding segments 331 are defined as: first folding segment 1, first folding segment 2, and first folding segment 3.

[0084] Please combine Figures 1 to 4 As shown, the first folding segment, the second folding segment, and the third folding segment are stacked sequentially from the driving end to the connecting end.

[0085] One end of the first folding segment is connected to one end of the mounting portion 32, and the other end of the first folding segment can extend from the second surface toward the first surface. The other end of the first folding segment is connected to one end of the second folding segment. The other end of the second folding segment can extend from the second surface toward the first surface. The other end of the second folding segment is connected to one end of the third folding segment, and the other end of the third folding segment can extend from the second surface toward the first surface. The other end of the third folding segment can be electrically connected to the moving contact 10.

[0086] The lengths of the first folding segment, the second folding segment, and the third folding segment can be the same, or they can be different. The sides of the first folding segment, the second folding segment, and the third folding segment that are away from the connecting part can be coplanar to reduce the space occupied by the folding structure 33. At the same time, the flow limiting component 3 is neater and has a more aesthetically pleasing appearance.

[0087] In one possible implementation, the boundary line between every two connected first folded segments 331 is perpendicular to the length direction of the bimetallic sheet 2 and the direction from the first surface to the second surface. In other words, the boundary line between every two connected first folded segments 331 is perpendicular to the length direction of the bimetallic sheet 2, and simultaneously, the boundary line between every two connected first folded segments 331 is perpendicular to the direction from the first surface to the second surface.

[0088] Thus, the multiple first folding segments 331 are parallel, and the sides of the multiple first folding segments 331 away from the connecting portion 31 can be coplanar, thereby reducing the space occupied by the folding structure 33. Furthermore, while ensuring the length of the flow limiting member 3, the space occupied by the flow limiting mechanism can be reduced. At the same time, the flow limiting member 3 has a neat appearance and an aesthetically pleasing shape.

[0089] It should be noted that the boundary line between any two connected first fold segments 331 refers to the connecting line formed at the connection point of the two first fold segments 331.

[0090] In one possible implementation, the current limiting element 3 provided in this application embodiment further includes an extension 34, such as... Figure 3 and Figure 4 As shown, the extension 34 is located on the side of the bimetallic strip 2 near the first surface. One end of the extension 34 is connected to the end of the folded structure 33 away from the mounting portion 32, and the other end of the extension 34 is used for electrical connection with the moving contact 10.

[0091] Thus, the extension 34 further increases the length of the current-limiting element 3 and the impedance of the current-limiting mechanism. In the event of an overload or short circuit in the circuit containing the circuit breaker, the current flowing through the circuit breaker can be further reduced. This ensures that the circuit breaker can withstand the electrodynamic repulsion and heat of the abnormal current during the circuit breaker's tripping process, reducing damage to the transformer and conductive lines and guaranteeing their safety.

[0092] The extension 34 and the folding structure 33 can be connected together by welding, snap-fitting, or by using screws, rivets, etc., but in practice, it is not limited to these methods.

[0093] In a specific implementation, the extension 34 can be a straight plate structure, and the extension direction of the straight plate extension 34 can be perpendicular to the length direction of the bimetallic strip 2, and the extension direction of the straight plate extension 34 can be parallel to the first surface.

[0094] It should be noted that, in the length direction of the bimetallic strip, the extension 34 can be connected to the end of the folded structure 33 near the connecting end, and the extension 34 can be located on the side of the connecting part 31 away from the driving end, so as to reduce the possibility that the arrangement of the extension 34 will interfere with the connection between the connecting part 31 and the connecting end.

[0095] In one example, the extension 34 has an L-shaped structure. In this case, the length of the current limiting element 3 can be further increased, thereby increasing the impedance of the current limiting mechanism.

[0096] At the same time, the structure of the extension 34 can be enriched, and the structural forms of the flow limiting element 3 can be increased, making it easier to select and set according to actual conditions.

[0097] In another example, the extension 34 includes a plurality of sequentially connected second folded segments, which are stacked along the length of the bimetallic strip 2.

[0098] Thus, the multiple second folding sections result in a longer overall length and higher resistance for the current-limiting element 3, increasing the impedance of the conductive lines. In the event of overload or short circuit in the circuit containing the circuit breaker, this reduces the current flowing through the circuit breaker. This ensures that the circuit breaker can withstand the electrodynamic repulsion and heat from abnormal currents during the breaking process, reducing damage to the transformer and conductive lines and guaranteeing their safety.

[0099] Multiple second folded segments are stacked along the length of the bimetallic strip 2, which can compress the longer flow restrictor 3 into a limited space, thus helping to reduce the space occupied by the flow restrictor mechanism.

[0100] In practice, the number of second fold segments can be three, four, five or more, and multiple second fold segments can be connected end to end in sequence.

[0101] In some embodiments, the boundary line between every two connected second fold segments is parallel to the direction from the first surface to the second surface.

[0102] In this way, the multiple second folding segments are parallel, and the sides of the multiple second folding segments away from the connecting part 31 can be coplanar, thereby reducing the space occupied by the multiple second folding segments. Furthermore, while ensuring the length of the flow limiting member 3, the space occupied by the flow limiting mechanism can be reduced. At the same time, the flow limiting member 3 has a neat appearance and an aesthetically pleasing shape.

[0103] Similarly, it should be noted that the boundary line between any two connected second fold segments refers to the connecting line formed at the connection point of the two second fold segments.

[0104] Additionally, it should be noted that the multiple second folding segments and the connecting portion 31 can be staggered along the length of the bimetallic strip 2; however, no specific limitation is made here. In practical implementation, the arrangement of the second folding segments should ensure that it does not affect the connection between the connecting end and the connecting portion 31.

[0105] In actual operation, the connecting part 31, the mounting part 32, the folding structure 33, and the extension part 34 can be set separately. During installation, the connecting part 31, the mounting part 32, the folding structure 33, and the extension part 34 can be connected in sequence by welding or screws.

[0106] In one possible implementation, the current limiting component 3 is an integral structure.

[0107] In this case, the connecting part 31, the mounting part 32, the folding structure 33, and the extension part 34 are integrally formed. This not only avoids stress concentration problems caused by other connection methods such as welding or screws, but also ensures higher dimensional accuracy and consistency, and improves the structural strength of the flow restrictor 3.

[0108] Furthermore, the elimination of the need for machining the current-limiting component 3 reduces material usage and avoids waste. Moreover, the integrated structure reduces connection points, lowering the risk of failure due to loose connections, corrosion, or fatigue, and improving fatigue resistance. Additionally, it reduces the number of parts and assembly steps for the current-limiting component 3, simplifying the operation process, improving the installation efficiency of the current-limiting mechanism, and further shortening the circuit breaker's production cycle.

[0109] In practice, the sheet metal can be bent in sequence to form the connecting part 31, the mounting part 32, the folding structure 33 and the extension part 34, thereby forming the flow limiting component 3.

[0110] As one possible implementation, the current limiting component 3 can be an iron-chromium-aluminum alloy current limiting component, a stainless steel current limiting component, or a constantan current limiting component. That is, the material of the current limiting component 3 can be one of iron-chromium-aluminum alloy, stainless steel, or constantan.

[0111] Of course, in actual implementation, the material of the current limiting component 3 can also be a high-resistance alloy or a heating resistance alloy, etc. This is just an example and is not intended to be a specific limitation.

[0112] In this way, the materials of the current limiting component 3 can be diversified, and the materials of the current limiting component 3 can be selected and set according to the actual situation.

[0113] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, "connection" or "joining" in mechanical structures can refer to a physical connection. A physical connection can be a fixed connection, such as a connection secured by fasteners, such as a connection secured by screws, bolts, or other fasteners; a physical connection can also be a detachable connection, such as a snap-fit ​​or interlocking connection; a physical connection can also be an integral connection, such as a connection formed by welding, bonding, or integral molding. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

Claims

1. A current-limiting mechanism, characterized in that, include: Connection plate, used for electrical connection with external devices; A bimetallic strip is electrically connected to the connecting plate; the bimetallic strip has a first surface and a second surface disposed opposite to each other. A current limiting component has a connecting portion, a mounting portion, and a folding structure connected in sequence; the connecting portion is disposed on the side of the bimetallic strip near the first surface or the second surface, and the connecting end of the bimetallic strip is disposed on the connecting portion; the mounting portion is located on the side of the bimetallic strip near the second surface; the folding structure is disposed on the side of the bimetallic strip, and the folding structure is used for electrical connection with the moving contact of a circuit breaker.

2. The current limiting mechanism according to claim 1, characterized in that, The folding structure has a plurality of first folding segments connected in sequence, and the plurality of first folding segments are stacked along the length direction of the bimetallic sheet.

3. The current limiting mechanism according to claim 2, characterized in that, The boundary line between any two connected first folded segments is perpendicular to the length direction of the bimetallic sheet and the direction from the first surface to the second surface.

4. The current limiting mechanism according to claim 1, characterized in that, The current limiting component further includes an extension located on the side of the bimetallic strip closer to the first surface; one end of the extension is connected to the end of the folded structure away from the mounting portion; the other end of the extension is used for electrical connection with the moving contact.

5. The current limiting mechanism according to claim 4, characterized in that, The extension has an L-shaped structure.

6. The current limiting mechanism according to claim 4, characterized in that, The extension includes a plurality of sequentially connected second folded segments, which are stacked along the length of the bimetallic sheet.

7. The current limiting mechanism according to claim 6, characterized in that, The boundary line between any two connected second folded segments is parallel to the direction from the first surface to the second surface.

8. The current limiting mechanism according to claim 1, characterized in that, The current limiting component is an integral structure.

9. The current limiting mechanism according to claim 1, characterized in that, The current limiting component is an iron-chromium-aluminum alloy current limiting component, a stainless steel current limiting component, or a constantan current limiting component.

10. A circuit breaker, characterized in that, include: The current limiting mechanism as described in any one of claims 1 to 9; The housing, wherein the current limiting mechanism is disposed on the housing; A movable contact is rotatably mounted on the housing and is electrically connected to the current limiting mechanism; A stationary contact is disposed in the housing; the stationary contact is used to contact or disengage from the moving contact. A tripping mechanism is disposed in the housing; the tripping mechanism is disposed at the drive end of the current limiting mechanism, and the current limiting mechanism is used to drive the tripping mechanism to trip.

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