circuit breaker

Abstract

The application discloses a circuit breaker. The circuit breaker comprises an arc extinguishing device and a magnetic tripping system, the magnetic tripping system comprises a contact assembly, the contact assembly comprises an upper arc striking piece and a stationary contact point, the upper arc striking piece comprises an electrically conductive part and a magnetically conductive part arranged integrally, the stationary contact point is arranged on the electrically conductive part, and the magnetically conductive part extends to one side of the arc extinguishing device; the electrically conductive part extends in a bent manner relative to the magnetically conductive part, and the bending angle between the electrically conductive part and the magnetically conductive part is alpha, the vertical distance between the connecting position of the magnetically conductive part and the electrically conductive part and the side surface of the stationary contact point away from the electrically conductive part is D3, the minimum distance between the connecting position of the magnetically conductive part and the electrically conductive part and the arc extinguishing device is D4, and when the rated current I of the circuit breaker is 1A-63A, alpha, D3 and D4 satisfy the following relationship: alpha=k0+(D3+D4)×2° / mm, wherein k0 is 16°-26°. The relationship between alpha and (D3+D4) in the circuit breaker is associated, and the two are effectively matched, so that the arc striking effect is improved and the risk of tip discharge is reduced.

Description

Technical Field

[0001] This application relates to the field of electronic technology, and more particularly to a circuit breaker. Background Technology

[0002] Miniature circuit breakers (MCBs) primarily function as overload and short-circuit protection devices in circuit systems. Temperature rise and breaking capacity are important indicators for evaluating their performance.

[0003] The arc-starting structure of a miniature circuit breaker generally consists of a stationary contact arc-starting angle, a moving contact, and a lower arc-starting plate. The stationary contact arc-starting angle primarily serves to conduct electricity and initiate arcing. However, an arc-starting angle made of a single material cannot simultaneously provide both good conductivity and arc-starting performance. Therefore, it requires the use of other components such as a support and magnetic conductive sheet. This not only wastes metal materials but also increases the difficulty of manufacturing the components, and the arc-starting angle is also easily eroded by the generated arc. Summary of the Invention

[0004] This application provides a circuit breaker to at least partially solve the above-mentioned technical problems.

[0005] To achieve the above objectives, according to a first aspect of this application, a circuit breaker is provided, comprising: An arc-extinguishing device; and a magnetic tripping system, including a contact assembly, the contact assembly including an upper arc-leading element and a stationary contact, the upper arc-leading element including an integrally formed conductive part and a magnetically conductive part, the stationary contact being disposed on the conductive part, the magnetically conductive part extending to one side of the arc-extinguishing device; the conductive part extending in a bent manner relative to the magnetically conductive part with a bending angle α between the conductive part and the magnetically conductive part, the vertical distance between the connection point of the magnetically conductive part and the conductive part and the surface of the stationary contact facing away from the conductive part being D3; the minimum distance between the connection point of the magnetically conductive part and the conductive part and the arc-extinguishing device being D4; when the rated current I of the circuit breaker is 1A~63A, α, D3 and D4 satisfy the following relationship: α=k0+ (D3+D4)×2° / mm, where k0 is 16°~26°.

[0006] Optionally, when I is 1A~16A, k0 is 16°~19°; When I is 20A~32A, k0 is 20°~21°; When I is 40A~63A, k0 is 20°~26°.

[0007] Optionally, I, α, D3, and D4 satisfy the following relationship: if I is 1A to 63A, then D3 is 2.0mm to 5.0mm, D4 is 1.0mm to 6.0mm, and α is 25° to 45°.

[0008] Optionally, the rated current I of the circuit breaker satisfies one of the following relationships with α, D3, and D4: If I is 1A~16A, then D3 is 3.5mm~5.0mm, D4 is 1.0mm~2.0mm, and α is 25°~33°; If I is 20A~32A, then D3 is 2.5mm~3.5mm, D4 is 2.0mm~4.0mm, and α is 30°~35°; If I is 40A~63A, then D3 is 2.0mm~3.5mm, D4 is 4.0mm~6.0mm, and α is 32°~45°.

[0009] Optionally, c = D3 / D4, where c is 1.75~5 when I is 1A~16A; 0.625~1.75 when I is 20A~32A; and 0.33~0.875 when I is 40A~63A.

[0010] Optionally, the contact assembly further includes a conductive layer that covers the surface of the upper arc-drawing member.

[0011] Optionally, when I is 1A~16A, the conductive layer includes a first metal layer; when I is 20A~63A, the conductive layer includes a first metal layer, and the conductive layer further includes a second metal layer and / or a metal-graphene composite layer located on the side surface of the first metal layer opposite to the upper arc-drawing element. When the conductive layer further includes the second metal layer and the metal-graphene composite layer, the second metal layer is located on the surface of the first metal layer, and the metal-graphene composite layer is located on the surface of the second metal layer.

[0012] Optionally, the thickness of the first metal layer is 5 μm to 8 μm; the thickness of the second metal layer is 0.05 μm to 1.0 μm; the thickness of the metal-graphene composite layer is 3.5 μm to 4.5 μm; and / or, the thickness of the conductive layer is 6 μm to 11 μm; and / or, the width of the upper arc-drawing element is 4 mm to 6 mm; and / or, the ratio of the width of the upper arc-drawing element to the thickness of the conductive layer is 363 to 1000.

[0013] Optionally, the material of the first metal layer includes one of copper and copper alloys; and / or, The material of the second metal layer includes one of silver and silver alloys; and / or, The metal-graphene composite layer comprises graphene and a metal material, wherein the metal material comprises at least one of copper, copper alloys, silver, and silver alloys.

[0014] Optionally, the graphene sheet diameter in the metal-graphene composite layer is 0.3 μm to 40 μm; and / or, the size of the metal grains in the metal-graphene composite layer is 90 nm to 110 nm; and / or, the metal-graphene composite layer is a silver-graphene electroplating layer, the electroplating solution comprising 10 g / L to 30 g / L potassium silver cyanide, 160 g / L to 200 g / L potassium cyanide, 0.15 g / L to 1.15 g / L graphene, and 3 g / L to 20 g / L dispersant, wherein the dispersant comprises at least one of alkyl sulfonates, sulfonate formaldehyde condensates, and sulfosuccinates, and the current density is 0.20 A / dm³. 2 ~0.30 A / dm 2 The electroplating time is 30-35 minutes.

[0015] Optionally, the conductive part is made of copper; the magnetic part is made of iron, steel, and iron alloys; and / or, the magnetic tripping system further includes an iron core, a coil, and a terminal block, the coil being wound around the iron core; the terminal block being connected to one end of the coil; the conductive part being connected to the other end of the coil; and the magnetic part being spaced apart from the coil.

[0016] Optionally, the circuit breaker further includes a thermal tripping system, which includes a connected moving contact and a lower arc-leading element, the lower arc-leading element extending to the side of the arc-extinguishing device opposite to the upper arc-leading element.

[0017] Optionally, the circuit breaker is a miniature circuit breaker; and / or, the material of the lower arc-leading element is steel, and the material of the magnetic conductive part is steel.

[0018] In the circuit breaker of this application embodiment, the upper arc-leading element includes a conductive part made of conductive material and a magnetic part made of magnetic material. Current flows through the conductive part of the upper arc-leading element to form a circuit with the stationary contact and the moving contact, completing the normal energization of the product. When the product breaks, the magnetic part of the upper arc-leading element can magnetically attract the arc to the arc-extinguishing chamber of the arc-extinguishing device to complete arc extinguishing. Furthermore, in the circuit breaker, the bending angle α of the upper arc-leading element is related to the vertical distance (D3+D4) between the arc-extinguishing device and the surface of the stationary contact away from the conductive part. When (D3+D4) is determined, α fluctuates within a defined range. By relating the bending angle of the upper arc-leading element to the vertical distance between the arc-extinguishing device and the surface of the stationary contact away from the conductive part, the two can work together effectively, improving the arc-leading effect while reducing the risk of tip discharge.

[0019] Other features and advantages of this application will be described in detail in the following detailed description section. Attached Figure Description

[0020] 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 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.

[0021] To gain a more complete understanding of this application and its beneficial effects, the following description will be provided in conjunction with the accompanying drawings, wherein the same reference numerals in the following description denote the same parts.

[0022] Figure 1 This is a three-dimensional structural schematic diagram of the upper arc member provided in an exemplary embodiment of this application; Figure 2 This is a schematic diagram of the main view structure of the upper arc member provided in an exemplary embodiment of this application; Figure 3 This is a top view of the upper arc member provided in an exemplary embodiment of this application; Figure 4 This is a schematic diagram of the assembly structure of the upper arc member and the stationary contact provided in an exemplary embodiment of this application; Figure 5 This is a cross-sectional view of a conductive portion with a conductive layer on its surface provided in an exemplary embodiment of this application. Figure 6 This is a schematic diagram of the magnetic tripping system provided in an exemplary embodiment of this application; Figure 7 This is a schematic diagram of the thermal tripping system provided in an exemplary embodiment of this application; Figure 8 This is a schematic diagram of the internal structure of a circuit breaker provided in an exemplary embodiment of this application.

[0023] Explanation of reference numerals in the attached figures: 10. Contact assembly; 1. Upper arc-leading component; 11. Conductive part; 111. First straight section; 112. First bent section; 113. Second straight section; 1131. First surface; 1132. Second surface; 114. Second bent section; 115. Third straight section; 12. Magnetic conductive part; 121. First sub-segment; 122. Second sub-segment; 2. Stationary contact; 3. Conductive layer; 100. Magnetic tripping system; 20. Iron core; 30. Coil; 40. Terminal block; 1000 Circuit breaker; 200 Arc extinguishing device; 300 Thermal tripping system; 31 Moving contact; 32 Lower arc-leading component; 400 Operating mechanism; 500 Housing. Detailed Implementation

[0024] 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 a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the protection scope of this application.

[0025] Please see Figures 1 to 8 This application provides a circuit breaker 1000 including an arc-extinguishing device 200 and a magnetic tripping system 100. The magnetic tripping system 100 includes a contact assembly 10, which includes an upper arc-leading element 1 and a stationary contact 2. The upper arc-leading element 1 includes an integrally formed conductive part 11 and a magnetically conductive part 12. The stationary contact 2 is disposed on the conductive part 11, and the magnetically conductive part 12 extends to one side of the arc-extinguishing device 200. The conductive part 11 bends relative to the magnetically conductive part 12, and the bending angle between the conductive part 11 and the magnetically conductive part 12 is α. The vertical distance between the connection point of the magnetically conductive part 12 and the conductive part 11 and the surface of the stationary contact 2 away from the conductive part 11 is D3. The minimum distance between the connection point of the magnetically conductive part 12 and the conductive part 11 and the arc-extinguishing device 200 is D4. When the rated current I of the circuit breaker 1000 is 1A~63A, α, D3, and D4 satisfy the following relationship: α=k0+ (D3+D4)×2° / mm, where k0 is 16°~26°.

[0026] As an electrical switching device, the circuit breaker 1000 can not only connect and disconnect the circuit like an ordinary switch, but more importantly, it can automatically trip and disconnect the circuit when the circuit experiences faults such as overload, short circuit or undervoltage, thus protecting the safety of the line and equipment.

[0027] The circuit breaker 1000 includes an arc extinguishing device 200 and a magnetic tripping system 100. The arc extinguishing device 200 is used to quickly extinguish the electric arc generated when the contacts break at the moment the circuit is cut off. The magnetic tripping system 100 is used to quickly and automatically drive the circuit breaker 1000 to trip and cut off the circuit when a serious overload or short circuit occurs in the circuit.

[0028] Please see Figure 8 The magnetic tripping system 100 includes a contact assembly 10, which is a structure in the circuit breaker 1000 used to cooperate with the moving contact 31 to realize the on / off control of the circuit. When the circuit is closed, the contact assembly 10 is in close contact with the movable moving contact 31 to form a current path; when the circuit is open, the contact assembly 10 separates from the moving contact 31 to cut off the circuit.

[0029] Specifically, the contact assembly 10 includes an upper arc-leading member 1, which includes a conductive portion 11 and a magnetically conductive portion 12. The conductive portion 11 and the magnetically conductive portion 12 are integrally formed and sequentially distributed. The conductive portion 11 is made of a conductive material, especially a highly conductive material, such as copper; the magnetically conductive portion 12 is made of a magnetically conductive material, especially a highly magnetically permeable material, such as steel. The integral formation of the conductive portion 11 and the magnetically conductive portion 12 can be achieved by integral molding, or by separately molding the conductive portion 11 and the magnetically conductive portion 12 and then welding or riveting them together. The conductive portion 11 and the magnetically conductive portion 12 are sequentially distributed, and the conductive portion 11 and the magnetically conductive portion 12 can be directly connected or indirectly connected. As an example, the upper arc-drawing member 1 also includes a transition section (not shown in the figure), the conductive part 11 is the head of the upper arc-drawing member 1, and the magnetic part 12 is the tail of the upper arc-drawing member 1. The conductive part 11 is connected to the magnetic part 12 through the transition section, and the material of the transition section includes conductive material and magnetic material.

[0030] The contact assembly 10 also includes a stationary contact 2, which is also a conductive component made of conductive material. The stationary contact 2 is disposed on the conductive portion 11 of the upper arc-leading member 1 to achieve circuit conduction. When the circuit is closed, the contact assembly 10 contacts the moving contact 31, specifically the stationary contact 2 contacts the moving contact 31. As an example, the stationary contact 2 is welded to the conductive portion 11; for example, the stationary contact 2 and the conductive portion 11 can be spot-welded together.

[0031] An electric arc is essentially a mass of high-temperature ionized gas. The upper arc-drawing component 1 is used to guide the electric arc from the stationary contact 2 to the arc-extinguishing device 200. The magnetic part 12 of the upper arc-drawing component 1 has excellent arc-drawing performance. The magnetic part 12 extends to one side of the arc-extinguishing device 200. When interrupting current, especially large current, the contact assembly 10 and the arc-extinguishing device 200 work together to extinguish the electric arc.

[0032] The upper arc-leading component 1 has a bent structure. The conductive part 11 and the magnetic part 12 of the upper arc-leading component 1 are not on the same straight line, so that the upper arc-leading component 1 can be placed in the confined space of the circuit breaker 1000.

[0033] When the product is broken, an electric arc will be generated between the moving contact 31 and the stationary contact 2. The electric arc is highly destructive to the product contacts. This problem can be solved in two ways: first, by hindering the generation of the electric arc, and second, by accelerating the extinguishing of the electric arc.

[0034] Since the upper arc-initiating element 1 in the contact assembly 10 serves a dual function of carrying current and initiating arc, its arc-initiating effect directly affects the arc extinguishing effect. Because the upper arc-initiating element 1 has a bent structure, it has been found in practice that the bending angle of the upper arc-initiating element 1 affects its arc-initiating effect. To improve arc initiation, the bending angle can optionally be controlled between 25° and 45°. This prevents the angle from being too large, which would prevent the arc from being introduced into the arc-extinguishing chamber of the arc-extinguishing device 200, and also prevents the angle from being too small, which could easily lead to adverse effects such as tip discharge.

[0035] Please see Figure 8 The vertical distance D3 between the connection point of the magnetically conductive part 12 and the conductive part 11 and the surface of the stationary contact 2 facing away from the conductive part 11 is defined as D3. By controlling the vertical distance between the connection point of the magnetically conductive part 12 and the conductive part 11 and the surface of the stationary contact 2 facing away from the conductive part 11, the arc-initiating effect of the upper arc-initiating member 1 can be effectively improved. Optionally, the vertical distance between the connection point of the magnetically conductive part 12 and the conductive part 11 and the surface of the stationary contact 2 facing away from the conductive part 11 is 1mm to 5mm, for example, D3 is 1mm, 2mm, 3mm, 4mm, or 5mm.

[0036] Please see Figure 8 The minimum distance between the connection point of the magnetically conductive part 12 and the conductive part 11 and the arc-extinguishing device 200 is D4mm. To ensure better arc-ignition performance of the upper arc-starting member 1, special attention needs to be paid to the distance between the magnetically conductive part 12 and the arc-extinguishing device 200. Optionally, the minimum distance between the connection point of the magnetically conductive part 12 and the conductive part 11 and the arc-extinguishing device 200 is 1mm to 6mm, for example, D4 ​​is 1mm, 2mm, 3mm, 4mm, 5mm, or 6mm.

[0037] from Figure 8 It can be seen that the sum of D3 and D4 (i.e., D3+D4) represents the vertical distance between the arc-extinguishing device 200 and the surface of the stationary contact 2 facing away from the conductive part 11. When the rated current I of the circuit breaker 1000 is 1A~63A, α, D3, and D4 satisfy the following relationship: α=k0+(D3+D4)×2° / mm, where k0 is 16°~26°. As an example, k0 is 16°, 17°, 18°, 19°, 20°, 21°, 22°, 23°, 24°, 25°, or 26°.

[0038] In the circuit breaker 1000, the upper arc-leading element 1 includes a conductive part 11 made of conductive material and a magnetic part 12 made of magnetic material. Current flows through the conductive part 11 of the upper arc-leading element 1 to form a circuit with the stationary contact 2 and the moving contact 31, completing the normal energization of the product. When the product is disconnected, the magnetic part 12 of the upper arc-leading element 1 can attract the arc to the arc-extinguishing chamber of the arc-extinguishing device 200 through magnetic attraction, completing the arc extinguishing. Furthermore, in the circuit breaker 1000, the bending angle α of the upper arc-leading element 1 is related to the vertical distance (D3+D4) between the arc-extinguishing device 200 and the surface of the stationary contact 2 away from the conductive part 11. When (D3+D4) is determined, α fluctuates within a certain range. By associating the bending angle of the upper arc-starting member 1 with the vertical distance between the arc-extinguishing device 200 and the surface of the stationary contact 2 away from the conductive part 11 in the circuit breaker 1000, the two can work together effectively to improve the arc-starting effect while reducing the risk of tip discharge.

[0039] In some embodiments of this application, when I is 1A~16A, k0 is 16°~19°; when I is 20A~32A, k0 is 20°~21°; and when I is 40A~63A, k0 is 20°~26°. It can be seen that as the rated current I of the circuit breaker 1000 increases, k0 increases, and correspondingly, α also increases. When the rated current I of the circuit breaker 1000 is large, increasing α helps reduce the risk of tip discharge of the upper arc-leading element 1.

[0040] In some embodiments of this application, c = D3 / D4. When I is 1A~16A, c is 1.75~5; when I is 20A~32A, c is 0.625~1.75; and when I is 40A~63A, c is 0.33~0.875. It can be seen that as I increases, c decreases, indicating that D3 decreases while D4 increases. A larger distance D4 results in a smaller distance D3, which promotes arc generation; conversely, a smaller distance D4, especially when it is negative, does not achieve a good arc-initiating effect.

[0041] In some embodiments of this application, I, α, D3, and D4 satisfy the following relationship: I is 1A~63A, then D3 is 2.0mm~5.0mm, D4 is 1.0mm~6.0mm, and α is 25°~45°.

[0042] Within the above range, the sum of D3 and D4 is 3.0 mm to 11.0 mm, c is 0.33 to 5, and α is 25° to 45°.

[0043] Within the above parameter range, the upper arc-starting component 1 effectively balances conductivity and magnetic permeability. On the one hand, it can suppress the generation of electric arc, and on the other hand, it can improve the arc-starting effect, accelerate the arc extinguishing, and reduce the occurrence of adverse conditions such as tip discharge.

[0044] As an example, D3 is 2.0mm, 2.5mm, 3.0mm, 3.5mm, 4.0mm, 4.5mm, or 5.0mm.

[0045] As an example, D4 ​​is 1.0mm, 2.0mm, 3.0mm, 4.0mm, 5.0mm, or 6.0mm.

[0046] As an example, α is 25°, 30°, 35°, 40°, or 45°.

[0047] In some embodiments of this application, the rated current I of the circuit breaker 1000 satisfies one of the following relationships with α, D3, and D4: If I is 1A~16A, then D3 is 3.5mm~5.0mm, D4 is 1.0mm~2.0mm, and α is 25°~33°; If I is 20A~32A, then D3 is 2.5mm~3.5mm, D4 is 2.0mm~4.0mm, and α is 30°~35°; If I is 40A~63A, then D3 is 2.0mm~3.5mm, D4 is 4.0mm~6.0mm, and α is 32°~45°.

[0048] It can be seen that as I increases, D3 decreases while D4 increases, and α also increases. This is beneficial for accelerating arc extinguishing and improving defects such as tip discharge.

[0049] In some embodiments of this application, the conductive portion 11 includes a first straight segment 111 and a first bent segment 112 connected together. The magnetically conductive portion 12 includes a first sub-segment 121, which is connected to the first straight segment 111 via the first bent segment 112. The angle between the first straight segment 111 and the first sub-segment 121 is a bending angle α, which is 25° to 45°.

[0050] In detail, the conductive part 11 includes a first straight segment 111 and a first curved segment 112, with one end of the first straight segment 111 connected to one end of the first curved segment 112. The first straight segment 111 extends in a straight line along a first direction, and the first curved segment 112 extends in a curved direction. As an example, the first curved segment 112 has an arc-shaped structure. The magnetically conductive part 12 includes a first sub-segment 121. The first sub-segment 121 extends in a straight line along a second direction, which intersects with the first direction. Specifically, the magnetically conductive part 12 is connected to the conductive part 11 by connecting the first sub-segment 121 to the first curved segment 112, in which case the first straight segment 111 is connected to the first sub-segment 121 through the first curved segment 112. The included angle α between the first straight segment 111 and the first sub-segment 121 is 25° to 45°. As an example, the included angle α is 25°, 30°, 35°, 40°, or 45°.

[0051] For some embodiments of this application, please refer to Figure 2 The conductive portion 11 further includes a second straight segment 113, which is connected to the end of the first straight segment 111 away from the first curved segment 112. The angle between the second straight segment 113 and the first straight segment 111 is an obtuse angle. The second straight segment 113 has a first surface 1131 and a second surface 1132 facing away from each other in its thickness direction. The magnetically conductive portion 12 is located on one side of the second straight segment 113 and corresponds to the first surface 1131. The stationary contact 2 is disposed on the second surface 1132. The second straight segment 113 extends in a straight line along a third direction, which intersects with the second direction and also with the first direction. In the conductive portion 11, the second straight segment 113, the first straight segment 111, and the first curved segment 112 are connected sequentially. Optionally, the angle between the second straight segment 113 and the first straight segment 111 is 120° to 170°.

[0052] With the above technical solution, the magnetic conductive part 12 and the stationary contact 2 are located on opposite sides of the second straight section 113, and the stationary contact 2 is used to contact the moving contact 31, which can avoid interference from the magnetic conductive part 12.

[0053] For some embodiments of this application, please refer to Figure 2 The magnetically conductive part 12 also includes a second sub-segment 122, which is connected to the end of the first sub-segment 121 away from the first curved segment 112. The angle between the second sub-segment 122 and the first sub-segment 121 is an obtuse angle, and the extending direction of the second sub-segment 122 is perpendicular to the extending direction of the second straight segment 113. Please refer to [link / reference]. Figure 8 When the contact assembly 10 is applied to the circuit breaker 1000, the second segment 122 extends to one side of the arc extinguishing device 200 to better introduce the arc into the arc extinguishing chamber of the arc extinguishing device 200. As an example, the angle between the second segment 122 and the first segment 121 is 120° to 170°.

[0054] For some embodiments of this application, please refer to Figure 2 The conductive portion 11 further includes a second bent segment 114 and a third straight segment 115. The third straight segment 115 is connected to the end of the second straight segment 113 away from the first straight segment 111 via the second bent segment 114, and the third straight segment 115 is opposite to the first sub-segment 121. Optionally, the third straight segment 115 is perpendicular to the second straight segment 113, and the second bent segment 114 is an arc-shaped structure extending in an arc. See also... Figure 6 When the contact assembly 10 is applied to the magnetic tripping system 100, the third straight section 115 is used to connect to the coil 30.

[0055] For some embodiments of this application, please refer to Figure 5 The contact assembly 10 also includes a conductive layer 3, which covers the surface of the upper arc-drawing member 1.

[0056] The surface of the upper arc-leading component 1 is covered with a conductive layer 3. The conductive layer 3 enhances the current-carrying capacity of the contact assembly 10 and also serves as a corrosion-resistant protective layer for the upper arc-leading component 1. In particular, the upper arc-leading component 1 includes a conductive part 11 and a magnetic part 12. These two parts are typically made of different materials, which can easily create a potential difference at the connection point, leading to galvanic corrosion. By covering the surface of the upper arc-leading component 1 with the conductive layer 3, the conductive layer 3 acts as a corrosion-resistant protective layer, preventing air and moisture from contacting the upper arc-leading component 1 and mitigating its corrosion.

[0057] In some embodiments of this application, when I is 1A to 16A, the conductive layer 3 includes a first metal layer. Optionally, the first metal layer is a copper layer. When the rated current of the circuit breaker 1000 is relatively small, it is difficult to generate an electric arc when the moving and stationary contacts open and close. The conductive layer 3 includes a first metal layer, and the metal itself has good electrical and thermal conductivity. The first metal layer can meet the requirements of conductivity, heat dissipation, and corrosion protection of the contact assembly 10. Optionally, the material of the first metal layer is the same as the material of the conductive part 11.

[0058] In some embodiments of this application, when I is 20A~63A, the conductive layer 3 includes a first metal layer, and the conductive layer 3 also includes a second metal layer and / or a metal-graphene composite layer located on the side surface of the first metal layer opposite to the upper arc-leading member 1. When the conductive layer 3 also includes a second metal layer and a metal-graphene composite layer, the second metal layer is located on the surface of the first metal layer, and the metal-graphene composite layer is located on the surface of the second metal layer.

[0059] In one example, the conductive layer 3 includes a first metal layer and a second metal layer. The first metal layer and the second metal layer are stacked sequentially in a direction away from the upper arc-leading member 1, that is, the first metal layer covers the surface of the upper arc-leading member 1 and the second metal layer covers the surface of the first metal layer.

[0060] In another example, the conductive layer 3 includes a first metal layer and a metal-graphene composite layer. Along the direction away from the upper arc-drawing member 1, the first metal layer and the metal-graphene composite layer are stacked in sequence, that is, the first metal layer covers the surface of the upper arc-drawing member 1, and the metal-graphene composite layer covers the surface of the first metal layer.

[0061] In another example, the conductive layer 3 includes a first metal layer, a second metal layer, and a metal-graphene composite layer. The first metal layer, the second metal layer, and the metal-graphene composite layer are stacked sequentially in a direction away from the upper arc-drawing member 1. That is, the first metal layer covers the surface of the upper arc-drawing member 1, the second metal layer covers the surface of the first metal layer, and the metal-graphene composite layer covers the surface of the second metal layer.

[0062] When the conductive layer 3 includes a metal-graphene composite layer, due to the skin effect, current will conduct on the conductive layer 3 outside the upper arc-leading element 1. The conductive layer 3 contains graphene with excellent conductivity, giving the contact assembly 10 good overall conductivity. Graphene is made from sp... 2 Hybridized carbon atoms are tightly packed into a single-layer two-dimensional honeycomb lattice structure. This ordered two-dimensional crystal structure endows graphene with extremely high thermal conductivity. The high thermal conductivity of graphene can quickly disperse the arc heat and slow down the heat accumulation at the interface of the upper arc-leading component 1. At the same time, the conductive layer 3 can form a protective layer at the interface of the upper arc-leading component 1 to delay heat intrusion, thereby effectively reducing the amount of material ablation loss, reducing the risk of the upper arc-leading component 1 being ablated by the arc, and improving the ablation resistance of the contact assembly 10.

[0063] The metal-graphene composite layer is a mixture of metal and graphene. By combining the advantages of both graphene and metal, the metal-graphene composite layer exhibits comprehensive advantages in electrical, thermal, mechanical, and protective properties that are difficult to match by traditional single materials. Optionally, if the metal includes silver, the metal-graphene composite layer is a silver-graphene composite layer, which combines the excellent conductivity of silver with the strength and wear resistance of graphene. As an example, graphene is added to an electroplating silver solution to form a silver-graphene composite layer through electroplating. Coating the surface of the upper arc-drawing component 1 with a silver-graphene composite layer can reduce the product's temperature rise and reduce the impact of heat on the thermal aging of other materials inside the product.

[0064] Optionally, the material of the first metal layer includes one of nickel, silver, copper, copper alloys, and silver alloys. The material of the second metal layer includes one of nickel, silver, copper, copper alloys, and silver alloys. The material of the metal-graphene composite layer includes graphene and a metallic material, wherein the metallic material includes at least one of nickel, nickel alloys, copper, copper alloys, silver, and silver alloys.

[0065] Furthermore, the material of the first metal layer includes copper and copper alloys. The material of the second metal layer includes silver and silver alloys. The material of the metal-graphene composite layer includes graphene and a metallic material, wherein the metallic material includes at least one of copper, copper alloys, silver, and silver alloys.

[0066] As an example, the first metal layer is a copper layer, the second metal layer is a silver layer, and the metal-graphene composite layer is a silver-graphene composite layer.

[0067] In the above scheme, the conductive layer 3 contains metal and graphene, thereby significantly improving the conductivity, heat dissipation and corrosion resistance of the contact assembly 10.

[0068] From a technological perspective, setting a first metal layer between the arc-drawing component 1 and the metal-graphene composite layer, or setting a first metal layer and a second metal layer between the arc-drawing component 1 and the metal-graphene composite layer, can effectively improve the uniformity of the metal-graphene composite layer. This is because the arc-drawing component 1 includes a conductive part 11 and a magnetic part 12. The conductive part 11 and the magnetic part 12 are typically made of different materials. This results in different potential differences between the conductive part 11 and the magnetic part 12 relative to the electroplating material during the electroplating process. Consequently, the deposition rate of the electroplating material on the conductive part 11 and the magnetic part 12 is different, leading to insufficient uniformity of the final metal-graphene composite layer. By first constructing a first metal layer, or a first metal layer and a second metal layer, on the surface of the arc-drawing component 1, the potential difference between the first metal layer or the second metal layer and the electroplating material is made the same, thereby promoting the formation of a uniform metal-graphene composite layer.

[0069] In some embodiments of this application, the thickness of the first metal layer is 5 μm to 8 μm. As an example, the thickness of the first metal layer is 5.0 μm, 5.5 μm, 6.0 μm, 6.5 μm, 7.0 μm, 7.5 μm, or 8.0 μm.

[0070] In some embodiments of this application, the thickness of the second metal layer is 0.05 μm to 1.0 μm. As examples, the thickness of the second metal layer is 0.05 μm, 0.1 μm, 0.2 μm, 0.3 μm, 0.4 μm, 0.5 μm, 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm, or 1.0 μm.

[0071] In some embodiments of this application, the thickness of the metal-graphene composite layer is 3.5 μm to 4.5 μm. As examples, the thickness of the metal-graphene composite layer is 3.5 μm, 3.7 μm, 3.9 μm, 4.1 μm, 4.3 μm, or 4.5 μm.

[0072] In some embodiments of this application, the thickness of the conductive layer 3 is 6 μm to 11 μm. A thicker conductive layer 3 provides better corrosion resistance, while a thinner layer is more susceptible to damage during subsequent processing, failing to achieve the intended corrosion protection. When the rated current carried by the contact assembly 10 is greater, the conductive layer 3 needs to be thicker; however, increasing the thickness of the conductive layer 3 leads to increased costs. As examples, the thickness of the conductive layer 3 is 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, or 11 μm.

[0073] For some embodiments of this application, please refer to Figure 2 and Figure 3The upper arc-leading component 1 is a plate with a thickness of D1 and a width of D2. The width D2 of the upper arc-leading component 1 is 4mm to 6mm. For example, D2 can be 4.0mm, 4.5mm, 5.0mm, 5.5mm, or 6.0mm. The width D2 of the upper arc-leading component 1 can be set according to requirements, but when D2 is within the above range, it can effectively support the stationary contact 2.

[0074] In some embodiments of this application, the ratio of the width D2 of the upper arc-leading member 1 to the thickness of the conductive layer 3 is 363 to 1000. As an example, the ratio of the width of the upper arc-leading member 1 to the thickness of the conductive layer 3 is 363, 400, 500, 600, 700, 800, 900 or 1000.

[0075] In some embodiments of this application, the graphene sheet diameter in the metal-graphene composite layer ranges from 0.3 μm to 40 μm. Graphene sheets of different diameters exhibit varying advantages and disadvantages in terms of mechanical reinforcement, electrical and thermal conductivity, and corrosion resistance. The smaller graphene sheet diameter in this metal-graphene composite layer results in better tensile strength and wear resistance, allowing for more effective filling of defects in the metal matrix and enhancing the reinforcement effect. Simultaneously, the better dispersibility of small-diameter graphene facilitates the construction of more thermally conductive pathways. Furthermore, graphene sheet diameters within the aforementioned range can result in a dense metal-graphene composite layer, improving corrosion resistance. As an example, the graphene sheet diameter in the metal-graphene composite layer is 0.3 μm, 1 μm, 5 μm, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, or 40 μm.

[0076] In some embodiments of this application, the size of the metal grains in the metal-graphene composite layer is 90 nm to 110 nm. In this case, the metal grains can combine with graphene to produce a unique "nanocrystalline-graphene" synergistic interface effect, enabling the metal-graphene composite layer to simultaneously achieve high strength, high electrical conductivity, and high thermal conductivity. As an example, the size of the metal grains in the metal-graphene composite layer is 90 nm, 95 nm, 100 nm, 105 nm, or 110 nm.

[0077] In some embodiments of this application, the metal-graphene composite layer is a silver-graphene electroplating layer. The electroplating solution includes 10 g / L to 30 g / L of potassium silver cyanide, 160 g / L to 200 g / L of potassium cyanide, 0.15 g / L to 1.15 g / L of graphene, and 3 g / L to 20 g / L of dispersant. The dispersant includes at least one of alkyl sulfonates, sulfonate formaldehyde condensates, and sulfosuccinates. The current density is 0.20 A / dm³. 2 ~0.30 A / dm 2 The electroplating time is 30-35 minutes.

[0078] The above-mentioned electroplating solution formulation is a silver cyanide-graphene composite electroplating solution. Potassium silver cyanide provides silver ions, while excess potassium cyanide acts as a complexing agent to stabilize the silver ions and prevent them from precipitating in the solution. This results in a plating solution with high stability, good dispersion and coverage, and a finely crystalline silver coating after electroplating. Graphene serves as a reinforcing phase; its addition improves the hardness, wear resistance, electrical conductivity, and thermal conductivity of the coating. However, graphene is highly prone to agglomeration. The role of the dispersant is to separate and stably suspend the graphene in the electroplating solution, ensuring that it can uniformly penetrate the coating rather than forming defects.

[0079] As an example, the concentrations of potassium silver cyanide in the electroplating solution are 10 g / L, 15 g / L, 20 g / L, 25 g / L, or 30 g / L; the concentrations of potassium cyanide are 160 g / L, 170 g / L, 180 g / L, 190 g / L, or 200 g / L; the concentrations of graphene are 0.15 g / L, 0.30 g / L, 0.45 g / L, 0.60 g / L, 0.75 g / L, 0.90 g / L, 1.05 g / L, or 1.15 g / L; and the concentrations of dispersant are 3 g / L, 6 g / L, 9 g / L, 12 g / L, 15 g / L, 18 g / L, or 20 g / L.

[0080] Current density is a crucial factor in controlling the amount of graphene co-deposited. By controlling the current density within the aforementioned range, the electric field force can be enhanced, driving more negatively charged graphene or graphene adsorbed with dispersants to move towards the cathode, thereby increasing the graphene content in the coating. As an example, a current density of 0.20 A / dm³ is used. 2 0.22 A / dm 2 0.24 A / dm 2 0.26 A / dm 2 0.28A / dm 2 Or 0.30 A / dm 2 .

[0081] Electroplating time primarily determines the coating thickness. 30-35 minutes is a relatively short deposition time, which may be suitable for preparing thinner coatings. As examples, electroplating times of 30, 31, 32, 33, 34, or 35 minutes are used.

[0082] In some embodiments of this application, the conductive part 11 is made of copper, and the magnetic part 12 is made of steel. Copper has a higher electron work function than steel, and high-temperature oxides have a weaker promoting effect on electron emission. In areas where arcs are easily generated at the moving and stationary contacts, the conductive part 11 is made of copper, which not only hinders the formation of arcs but also utilizes the excellent conductivity of copper to reduce the internal resistance and temperature rise of the upper arc-drawing member 1. Steel, as a highly magnetic material, can promote the entry of the arc into the arc-extinguishing device 200.

[0083] When the load current of the contact assembly 10 is small and the voltage is not high, it is difficult to generate an electric arc when the moving contact 31 and the stationary contact 2 are opening and closing. Even if a small electric arc is generated, the impact on the product contacts is very small. In this case, the upper arc-initiating component 1 can be made of materials such as steel that have arc-initiating function and general conductivity to save manufacturing costs.

[0084] For some embodiments of this application, please refer to Figure 1 and Figure 6 The magnetic tripping system 100 includes an iron core 20, a coil 30, a terminal block 40, and a contact assembly 10. The coil 30 is wound around the iron core 20; the terminal block 40 is connected to one end of the coil 30; the conductive part 11 of the contact assembly 10 is connected to the other end of the coil 30, and the magnetic part 12 is spaced apart from the coil 30.

[0085] The magnetic trip system 100 uses electromagnetic force to control the contact switch. When the circuit is working normally, the current is within the normal range, and the magnetic trip system 100 does not generate sufficient electromagnetic force, so the contacts remain closed and the power supply is normal. When a short circuit or severe overload occurs, the current increases sharply and instantaneously. The current through the coil 30 of the magnetic trip system 100 also increases accordingly. The coil 30 generates a strong electromagnetic force, pulling the iron core 20 to open the contacts and cut off the power supply. The entire tripping process takes only a few milliseconds, effectively preventing the electrical appliances using this magnetic trip system 100 from burning out.

[0086] For some embodiments of this application, please refer to Figure 1 , Figure 7 and Figure 8 The circuit breaker 1000 also includes a thermal trip system 300. The thermal trip system 300 includes a connected moving contact 31 and a lower arc-leading element 32, which extends to the side of the arc-extinguishing device 200 opposite to the upper arc-leading element 1. In the magnetic trip system 100, the magnetically conductive portion 12 of the upper arc-leading element 1 extends to the side of the arc-extinguishing device 200 opposite to the lower arc-leading element 32.

[0087] The current flows through the moving contact 31 of the thermal trip system 300, the stationary contact 2 of the contact assembly 10, and the conductive part 11 of the upper arc-leading member 1, and then flows out of the product through the coil 30 of the magnetic trip system 100. When the product breaks, an electric arc is generated between the moving contact 31 and the stationary contact 2, and enters the arc-extinguishing device 200 through the area between the upper arc-leading member 1 and the lower arc-leading member 32.

[0088] When the arc-initiating capabilities of the upper arc-initiating component 1 and the lower arc-initiating component 32 are different, the arc below the arc-extinguishing device 200 can more easily enter the arc-extinguishing device 200, while the arc above it has difficulty entering. As a result, the arc stagnates at the bend below the upper arc-initiating component 1, which can burn out internal parts of the product. This embodiment of the application improves the arc-initiating effect of the upper arc-initiating component 1 by controlling the bending angle α of the upper arc-initiating component 1, thus mitigating the problem of arc stagnation.

[0089] In some embodiments of this application, the lower arc-starting element 32 is made of steel, and the magnetically conductive part 12 is also made of steel. Under normal circumstances, the lower arc-starting element 32 does not pass through a current-carrying circuit and uses highly magnetically conductive materials such as steel to facilitate the entry of the electric arc into the arc-extinguishing device 200. The magnetically conductive part 12 is also made of steel, making the arc-starting capability of the upper arc-starting element 1 comparable to that of the lower arc-starting element 32. After the arc is generated, the magnetically conductive part 12 of the upper arc-starting element 1 and the lower arc-starting element 32 work together to start the arc, accelerating the process of guiding the arc to the arc-extinguishing device 200 to complete the arc extinguishing.

[0090] For some embodiments of this application, please refer to Figure 8 The circuit breaker 1000 also includes an operating mechanism 400, which is connected to the moving contact 31. The circuit breaker 1000 also includes a housing 500, in which the arc extinguishing device 200, the thermal tripping system 300 and the magnetic tripping system 100 are all disposed. A part of the operating mechanism 400 is located inside the housing 500, and another part extends out of the housing 500.

[0091] In some embodiments of this application, the circuit breaker 1000 is a miniature circuit breaker.

[0092] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0093] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0094] The embodiments, implementation methods, and related technical features of this application can be combined and substituted for each other without conflict.

[0095] The above are merely preferred embodiments of this application and are not intended to limit this application in any way. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of this application without departing from the scope of the technical solution of this application shall still fall within the scope of the technical solution of this application.

Claims

1. A circuit breaker (1000), characterized in that, include: Arc extinguishing device (200); as well as A magnetic tripping system (100) includes a contact assembly (10), the contact assembly (10) including an upper arc-leading element (1) and a stationary contact (2), the upper arc-leading element (1) including an integrally formed conductive part (11) and a magnetically conductive part (12), the stationary contact (2) being disposed on the conductive part (11), the magnetically conductive part (12) extending to one side of the arc-extinguishing device (200); the conductive part (11) is bent and extended relative to the magnetically conductive part (12), and the conductive part (11) The bending angle between the magnetic conductive part (12) and the conductive part (11) is α, and the vertical distance between the connection point of the magnetic conductive part (12) and the conductive part (11) and the side surface of the stationary contact (2) away from the conductive part (11) is D3; the minimum distance between the connection point of the magnetic conductive part (12) and the conductive part (11) and the arc extinguishing device (200) is D4; when the rated current I of the circuit breaker (1000) is 1A~63A, α, D3 and D4 satisfy the following relationship: α = k0 + (D3 + D4) × 2° / mm, where k0 is 16°~26°.

2. The circuit breaker (1000) according to claim 1, characterized in that, When I is 1A~16A, k0 is 16°~19°; When I is 20A~32A, k0 is 20°~21°; When I is 40A~63A, k0 is 20°~26°.

3. The circuit breaker (1000) according to claim 1, characterized in that, I satisfies the following relationship with α, D3, and D4: If I is 1A~63A, then D3 is 2.0mm~5.0mm, D4 is 1.0mm~6.0mm, and α is 25°~45°.

4. The circuit breaker (1000) according to claim 3, characterized in that, The rated current I of the circuit breaker (1000) satisfies one of the following relationships with α, D3, and D4: If I is 1A~16A, then D3 is 3.5mm~5.0mm, D4 is 1.0mm~2.0mm, and α is 25°~33°; If I is 20A~32A, then D3 is 2.5mm~3.5mm, D4 is 2.0mm~4.0mm, and α is 30°~35°; If I is 40A~63A, then D3 is 2.0mm~3.5mm, D4 is 4.0mm~6.0mm, and α is 32°~45°.

5. The circuit breaker (1000) according to any one of claims 1 to 4, characterized in that, c = D3 / D4. When I is 1A~16A, c is 1.75~5; when I is 20A~32A, c is 0.625~1.75; when I is 40A~63A, c is 0.33~0.

875.

6. The circuit breaker (1000) according to any one of claims 1 to 4, characterized in that, The contact assembly (10) further includes a conductive layer (3) which covers the surface of the upper arc-drawing member (1).

7. The circuit breaker (1000) according to claim 6, characterized in that, When I is 1A~16A, the conductive layer (3) includes a first metal layer; When I is 20A~63A, the conductive layer (3) includes a first metal layer, and the conductive layer (3) also includes a second metal layer and / or a metal-graphene composite layer located on the side surface of the first metal layer away from the upper arc-drawing member (1). When the conductive layer (3) also includes the second metal layer and the metal-graphene composite layer, the second metal layer is located on the surface of the first metal layer, and the metal-graphene composite layer is located on the surface of the second metal layer.

8. The circuit breaker (1000) according to claim 7, characterized in that, The thickness of the first metal layer is 5 μm to 8 μm; the thickness of the second metal layer is 0.05 μm to 1.0 μm; the thickness of the metal-graphene composite layer is 3.5 μm to 4.5 μm; and / or, The thickness of the conductive layer (3) is 6 μm to 11 μm; and / or, The width of the upper arc-drawing component (1) is 4mm~6mm; and / or, The ratio of the width of the upper arc-drawing element (1) to the thickness of the conductive layer (3) is 363~1000; and / or, The material of the first metal layer includes one of copper and copper alloys; and / or, The material of the second metal layer includes one of silver and silver alloys; and / or, The metal-graphene composite layer comprises graphene and a metal material, wherein the metal material comprises at least one of copper, copper alloys, silver, and silver alloys.

9. The circuit breaker (1000) according to claim 7, characterized in that, The graphene sheets in the metal-graphene composite layer have a diameter of 0.3 μm to 40 μm; and / or, The size of the metal grains in the metal-graphene composite layer is 90 nm to 110 nm; and / or, The metal-graphene composite layer is a silver-graphene electroplating layer. The electroplating solution includes 10 g / L to 30 g / L potassium silver cyanide, 160 g / L to 200 g / L potassium cyanide, 0.15 g / L to 1.15 g / L graphene, and 3 g / L to 20 g / L dispersant. The dispersant includes at least one of alkyl sulfonates, sulfonate formaldehyde condensates, and sulfosuccinates. The current density is 0.20 A / dm³. 2 ~0.30A / dm 2 The electroplating time is 30-35 minutes.

10. The circuit breaker (1000) according to any one of claims 1 to 4, characterized in that, The material of the conductive part (11) includes copper; the material of the magnetic part (12) includes one of iron, steel, and iron alloys; and / or, The magnetic tripping system (100) further includes an iron core (20), a coil (30) and a terminal block (40), wherein the coil (30) is wound around the iron core (20); the terminal block (40) is connected to one end of the coil (30); the conductive part (11) is connected to the other end of the coil (30); and the magnetic conductive part (12) is spaced apart from the coil (30).

11. The circuit breaker (1000) according to any one of claims 1 to 4, characterized in that, The circuit breaker (1000) also includes a thermal trip system (300), which includes a connected moving contact (31) and a lower arc-leading element (32), the lower arc-leading element (32) extending to the side of the arc-extinguishing device (200) away from the upper arc-leading element (1).

12. The circuit breaker (1000) according to claim 11, characterized in that, The circuit breaker (1000) is a miniature circuit breaker; and / or, The material of the lower arc-drawing component (32) is steel, and the material of the magnetic conductive part (12) is steel.

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