Contact structure for reducing arc generation of direct-current circuit breaker
By designing a contact structure that includes a flexible metal strip and a resistance element, the generation of electric arcs is reduced, solving the problem of contact damage caused by electric arcs during the disconnection process of traditional DC circuit breakers, and improving the reliability and lifespan of the circuit breaker.
Patent Information
- Application Number
- CN202423084315.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-13
- Publication Date
- 2025-11-14
- Estimated Expiration
- 2034-12-13
AI Technical Summary
Traditional DC circuit breakers generate electric arcs during the disconnection process, which damages the contact surface and affects system reliability. Existing arc extinguishing structures cannot effectively reduce the initial generation of electric arcs.
Design a contact structure including a moving contact and a stationary contact. The moving contact consists of an elastic metal strip, a resistive sheet, and an insulating block. By gradually increasing the resistance during circuit breaking, the current is reduced to avoid arcing. Specifically, the elastic metal strip slides over the resistive sheet and the insulating block, whose resistance gradually increases.
It effectively reduces the generation of electric arcs, protects the contact surface, and improves the reliability and service life of the circuit breaker.
Smart Images
Figure CN223552488U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of DC circuit breaker technology, specifically to a contact structure for reducing arc generation in DC circuit breakers. Background Technology
[0002] The widespread use of DC circuit breakers has effectively improved the safety of electrical appliances. In order to meet the trend of miniaturization of electrical equipment, the overall structure and operation of circuit breakers that are compatible with them also need to be continuously upgraded and improved.
[0003] In existing technologies, traditional DC circuit breakers generate an electric arc when the moving and fixed contacts separate during the disconnection process. Although most traditional DC circuit breakers are equipped with arc-extinguishing structures, such as arc-extinguishing grids or arc-blowing magnetic fields, to quickly extinguish the arc by lengthening or dispersing it and reducing its destructive effects, the main function of the arc-extinguishing structure is to prevent the arc from continuing to burn. At the moment the arc is first generated, it will still briefly cause the contact surface to melt or erode. Over time, these brief arcs will damage the contact surface, forming localized ablation points, which will make the contact surface rougher or uneven, leading to poor contact and affecting the reliability of the entire system. Therefore, there is an urgent need for a contact structure that reduces the generation of arcs to lower the probability of arc generation. Utility Model Content
[0004] To address the aforementioned technical deficiencies, this invention provides a contact structure for a DC circuit breaker that reduces arc generation, thereby minimizing arc generation during disconnection.
[0005] This utility model discloses a contact structure for reducing arc generation in a DC circuit breaker, including a housing, an arc extinguishing system, a contact structure, an operating mechanism for driving the contact structure, a thermal bimetallic trip unit for driving the contact structure, and an electromagnetic trip unit for driving the contact structure. The contact structure includes a moving contact and a stationary contact. The stationary contact includes a metal mounting base, an elastic metal sheet, and a spring. The metal mounting base is installed inside the housing and is electrically connected to a first terminal. An elastic metal sheet is provided on one side of the metal mounting base. One end of the elastic metal sheet is fixed to the metal mounting base, and the other end of the elastic metal sheet is away from the metal mounting base, with a spring between this end and the metal mounting base. One end of the spring is fixed to the elastic metal sheet, and the other end of the spring... Fixed to the metal mounting base, the moving contact includes an elastic metal strip, a resistive element, an insulating block, and a connector. One end of the elastic metal strip is fixed inside the housing and electrically connected to the second terminal. The other end of the elastic metal strip is close to the metal mounting base. On the end of the elastic metal strip close to the metal mounting base, resistive elements with gradually increasing resistance are stacked in sequence. An insulating block is stacked on the resistive element with the highest resistance. The insulating block, resistive elements, and elastic metal strip are fixedly connected by the connector. The end of the elastic metal element away from the metal mounting base presses against the resistive element with the lowest resistance. It should be noted that when overloaded, the thermal bimetallic trip unit's driving contact structure should move the elastic metal strip away from the metal mounting base. When short-circuited, the electromagnetic trip unit's driving contact structure should move the elastic metal strip away from the metal mounting base.
[0006] The principle of the above technical solution is that an electric arc can only be generated between the contacts when the current in the circuit is not less than a certain threshold and the voltage is high enough. When the elastic metal strip moves away from the metal mounting base due to a short circuit or overload, the elastic metal strip successively presses against and slides past resistors with gradually increasing resistance values, and finally presses against the insulating block. When sliding past resistors with gradually increasing resistance values, the current in the circuit gradually decreases. When the elastic metal strip slides to the resistor with the largest resistance value, the current is small enough, thereby reducing the generation of an electric arc when the elastic metal strip slides past the resistor with the largest resistance value to the insulating block.
[0007] Furthermore, the connectors include insulating bolts and nuts, and the insulating block, resistor sheet, and elastic metal strip are provided with corresponding mounting holes. The insulating bolts pass through the mounting holes and the nuts are used to fix the insulating block, resistor sheet, and elastic metal strip together.
[0008] The contact structure of the DC circuit breaker obtained by this utility model reduces the generation of electric arc. Its beneficial effect is that when the elastic metal strip moves away from the metal mounting base due to short circuit or overload, the elastic metal strip successively presses against the resistor with gradually increasing resistance value, and finally presses against the insulating block. The current in the circuit gradually decreases, thereby reducing the generation of electric arc when the elastic metal strip slides past the resistor with the largest resistance value to the insulating block. Attached Figure Description
[0009] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of the present utility model;
[0010] Figure 2 This is Embodiment 1 of the present utility model. Figure 1 A magnified view of a portion of the image. Detailed Implementation
[0011] To further illustrate the technical means and effects adopted by this utility model in order to achieve the intended utility model purpose, the following detailed description of the specific implementation methods, structure, features and effects of this utility model is provided in conjunction with the accompanying drawings and preferred embodiments.
[0012] Example 1:
[0013] like Figure 1 , 2 As shown, this utility model discloses a contact structure for reducing arc generation in a DC circuit breaker, including a housing 1. Inside the housing 1 are an arc-extinguishing system 2, a contact structure, an operating mechanism 5 for driving the contact structure, a thermal bimetallic trip unit 7 for driving the contact structure, and an electromagnetic trip unit 4 for driving the contact structure. The contact structure includes a moving contact and a stationary contact. The stationary contact includes a metal mounting base 9, an elastic metal sheet 10, and a spring 15. The metal mounting base 9 is installed inside the housing 1 and is electrically connected to a first terminal 3. An elastic metal sheet 10 is provided on one side of the metal mounting base 9. One end of the elastic metal sheet 10 is fixed to the metal mounting base 9, and the other end of the elastic metal sheet 10 is away from the metal mounting base 9, with a spring 15 positioned between this end and the metal mounting base 9. One end of the spring 15 is fixed to the elastic metal sheet 10, and the other end of the spring 15 is fixed to the metal mounting base 9. The moving contact includes an elastic metal strip 8, a resistance sheet 13, an insulating block 12, and a connector. The elastic metal strip 8... One end is fixed inside the housing 1, and the elastic metal strip 8 is electrically connected to the second terminal 6. The other end of the elastic metal strip 8 is close to the metal mounting base 9. On the end of the elastic metal strip 8 close to the metal mounting base 9, resistors 13 with gradually increasing resistance are stacked in sequence. An insulating block 12 is stacked on the resistor 13 with the largest resistance. The insulating block 12, resistors 13 and elastic metal strip 8 are fixedly connected by a connector, which includes an insulating bolt 11 and a nut 14. The insulating block 12, resistors 13 and elastic metal strip 8 are respectively provided with mounting holes. The insulating bolt 11 passes through the mounting hole and is fixed together with the insulating block 12, resistors 13 and elastic metal strip 8 by the nut 14. The end of the elastic metal strip 10 away from the metal mounting base 9 presses against the resistor 13 with the smallest resistance. It should be noted that when overloaded, the thermal bimetallic trip unit 7 should drive the contact structure to move the elastic metal strip 8 away from the metal mounting base 9. When short-circuited, the electromagnetic trip unit 4 should drive the contact structure to move the elastic metal strip 8 away from the metal mounting base 9.
[0014] The principle of the above technical solution is that an electric arc can only be generated between the contacts when the current in the circuit is not less than a certain threshold and the voltage is high enough. In the above structure, when the elastic metal strip 8 moves away from the metal mounting base 9 due to short circuit or overload, the elastic metal sheet 10 successively presses against the resistor sheet 13 with gradually increasing resistance and finally presses against the insulating block 12. When it slides over the resistor sheet 13 with gradually increasing resistance, the current in the circuit gradually decreases. When the elastic metal sheet 10 slides to the resistor sheet 13 with the largest resistance, the current is small enough to reduce the generation of electric arc when the elastic metal sheet 10 slides over the resistor sheet 13 with the largest resistance to the insulating block 12.
Claims
1. A contact structure for reducing arc generation in a DC circuit breaker, comprising a housing (1), an arc extinguishing system (2), a contact structure, an operating mechanism (5) for driving the contact structure to operate, a thermal bimetallic trip unit (7) for driving the contact structure to operate, and an electromagnetic trip unit (4) for driving the contact structure to operate, characterized in that, The contact structure includes a moving contact and a stationary contact. The stationary contact includes a metal mounting base (9), an elastic metal sheet (10), and a spring (15). The metal mounting base (9) is installed inside the housing (1) and is electrically connected to the first terminal (3). An elastic metal sheet (10) is provided on one side of the metal mounting base (9). One end of the elastic metal sheet (10) is fixed to the metal mounting base (9), and the other end of the elastic metal sheet (10) is away from the metal mounting base (9), with a spring (15) provided between this end and the metal mounting base (9). One end of the spring (15) is fixed to the elastic metal sheet (10), and the other end of the spring (15) is fixed to the metal mounting base (9). The moving contact includes an elastic metal sheet (9). Metal strip (8), resistor (13), insulating block (12), connector. One end of the elastic metal strip (8) is fixed inside the housing (1). The elastic metal strip (8) is electrically connected to the second terminal (6). The other end of the elastic metal strip (8) is close to the metal mounting base (9). On the end of the elastic metal strip (8) close to the metal mounting base (9), resistors (13) with gradually increasing resistance are stacked in sequence. The insulating block (12) is stacked on the resistor (13) with the largest resistance. The insulating block (12), resistor (13) and elastic metal strip (8) are fixedly connected by the connector. The end of the elastic metal strip (10) away from the metal mounting base (9) presses against the resistor (13) with the smallest resistance.
2. The contact structure for reducing arc generation in a DC circuit breaker according to claim 1, characterized in that, The connectors include insulating bolts (11), nuts (14), insulating blocks (12), resistors (13), and elastic metal strips (8) with corresponding mounting holes. The insulating bolts (11) pass through the mounting holes and the nuts (14) fix the insulating blocks (12), resistors (13), and elastic metal strips (8) together.