Arc extinguishing structure of circuit breaker
By optimizing the arc-extinguishing structure of the circuit breaker and adopting three sets of arc-extinguishing grid plates and slit assemblies, efficient arc segmentation and cooling are achieved, solving the problem of poor arc ignition effect of stationary contacts and improving the reliability and breaking performance of the circuit breaker.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- ZHEJIANG BENYI NEW ENERGY CO LTD
- Filing Date
- 2025-04-14
- Publication Date
- 2026-05-12
AI Technical Summary
The existing circuit breaker stationary contacts have poor arc-initiating performance, which affects the reliability and breaking performance of the circuit breaker.
Design an arc extinguishing structure comprising three sets of arc extinguishing grids, with stationary and moving contacts positioned between the first, second, and third sets of arc extinguishing grids. Combined with a slit assembly and a gas-generating plate, and by optimizing the layout of the arc extinguishing grids and the setting of the arc-initiating plate, multi-level efficient segmentation and cooling of the electric arc can be achieved.
It improves arc extinguishing effect, reduces circuit breaker temperature rise, enhances circuit breaker operation safety and stability, and extends contact life.
Smart Images
Figure CN224232629U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of low-voltage switchgear, specifically relating to an arc-extinguishing structure for a circuit breaker. Background Technology
[0002] Circuit breakers are the most important power distribution equipment in low-voltage power distribution systems. With the increasing demands on power supply and transmission equipment in power engineering, the performance requirements for circuit protection switches are also becoming increasingly stringent. Miniaturization, high performance, modularization, and high reliability are the main development directions for molded case circuit breakers (MCCBs) at present. The contact system and arc-extinguishing system are crucial components of MCBs, and their design is critical, directly affecting the electrical life and breaking capacity of the MCB. Existing circuit breaker stationary contacts consist of a stationary contact plate and a stationary contact point. Typically, an arc-initiating structure is added near the stationary contact point to introduce the arc into the circuit breaker's arc-extinguishing chamber, reducing the arc's residence time on the stationary contact and thus reducing arc burn-in, providing protection for the stationary contact. However, the existing stationary contact's arc-initiating effect is poor, affecting the circuit breaker's reliability and reducing its breaking performance. Utility Model Content
[0003] The purpose of this invention is to overcome the shortcomings and deficiencies of the existing technology and to provide an arc-extinguishing structure for a circuit breaker.
[0004] The technical solution adopted by this utility model is as follows: an arc-extinguishing structure for a circuit breaker, comprising a circuit breaker housing and an arc-extinguishing chamber, a stationary contact, and a moving contact disposed within the circuit breaker housing; the circuit breaker housing is provided with a discharge port;
[0005] The arc-extinguishing chamber includes two fixed plates and a first arc-extinguishing grid plate group, a second arc-extinguishing grid plate group, and a third arc-extinguishing grid plate group, which are sequentially arranged between the two fixed plates.
[0006] The first arc-extinguishing grid plate group consists of several parallel first arc-extinguishing grid plates, which are arranged horizontally. The third arc-extinguishing grid plate group consists of several parallel third arc-extinguishing grid plates, which are inclined at an angle α relative to the horizontal direction and their outlet ends tend to be inclined towards the second arc-extinguishing grid plate group, where α is greater than 45° and less than 90°. The second arc-extinguishing grid plate group consists of several second arc-extinguishing grid plates, which are arranged at an angle β between themselves and their adjacent arc-extinguishing grid plates, where the distance between their inlet ends is less than the distance between their outlet ends, where β is greater than 0 and less than 15°.
[0007] The discharge outlet is located outside the outlet of the second arc-extinguishing grid assembly;
[0008] The stationary contact of the stationary contact and the moving contact of the moving contact are located in the area between the first arc-extinguishing grid group, the second arc-extinguishing grid group, and the third arc-extinguishing grid group.
[0009] The angle β between the second arc-extinguishing grid and the adjacent arc-extinguishing grid is equal.
[0010] The inlet ends of the second arc-extinguishing grids in the second arc-extinguishing grid group are arranged in a V-shape.
[0011] The inlet ends of the first arc-extinguishing grids in the first arc-extinguishing grid group are inclined, and the inlet ends of the first arc-extinguishing grids on the side away from the second arc-extinguishing grid group tend to be set towards the third arc-extinguishing grid group.
[0012] The stationary contact of the stationary contact is located at the center of the third arc-extinguishing grid group, and the moving contact of the moving contact is rotatably located on the side of the stationary contact away from the first arc-extinguishing grid group.
[0013] It also includes a slit assembly, which includes two gas-generating plates disposed in the region between the first arc-extinguishing grid group, the second arc-extinguishing grid group and the third arc-extinguishing grid group, with a slit between the two gas-generating plates forming a slit to accommodate a stationary contact and a moving contact; the slit assembly includes a magnetizing plate fixed to the outside of the gas-generating plates.
[0014] The slit assembly is fixed to the inner wall of the circuit breaker housing.
[0015] The stationary contact includes a first arc-inducing plate extending to the side of the first arc-extinguishing grid group away from the second arc-extinguishing grid group, with a 5mm-10mm gap between the first arc-inducing plate and the first arc-extinguishing grid group; the third arc-extinguishing grid group is provided with a second arc-inducing plate on the side away from the second arc-extinguishing grid group, and the second arc-inducing plate is provided with an arc-inducing portion extending to the outside of the moving contact located at the open position away from the stationary contact.
[0016] The moving contact has an arc-inducing tip, which is located at the outer end of the moving contact and its rotation path is outside the rotation path of the moving contact. The arc-inducing tip and the moving contact are located on opposite sides of the moving contact.
[0017] The outlet ends of the first and third arc-extinguishing grid plates are provided with air venting grooves to form an air venting channel between the first and third arc-extinguishing grid plate groups and the circuit breaker housing.
[0018] The beneficial effects of this utility model are as follows: By optimizing the layout of the arc-extinguishing grid, this utility model effectively improves the arc-extinguishing effect and reduces the temperature rise of the circuit breaker. Attached Figure Description
[0019] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, obtaining other drawings based on these drawings without creative effort still falls within the scope of this utility model.
[0020] Figure 1 This is a schematic diagram of the structure of the hidden top cover in Example 1;
[0021] Figure 2 This is a cross-sectional view of Example 1;
[0022] Figure 3 This is a schematic diagram of the arc-extinguishing structure in Example 1;
[0023] Figure 4 This is a cross-sectional view of the arc-extinguishing structure in Example 1;
[0024] Figure 5 This is a schematic diagram of the arc-extinguishing grid in Example 1;
[0025] Figure 6 This is a schematic diagram of the upper cover structure in Example 1;
[0026] Figure 7 This is a schematic diagram of the bottom cover structure in Example 1;
[0027] Figure 8 This is a cross-sectional view of Example 2;
[0028] Figure 9 This is a schematic diagram of the moving contact in Example 2;
[0029] In the diagram, the circuit breaker housing is 100, the outlet is 110, the bottom cover is 120, the top cover is 130, the positioning post is 140, the arc-extinguishing chamber is 200, the fixing plate is 210, the first arc-extinguishing grid assembly is 220, the second arc-extinguishing grid assembly is 230, the third arc-extinguishing grid assembly is 240, the second arc-starting plate is 250, the arc-running groove is 260, the stationary contact is 300, the stationary contact point is 310, the first arc-starting plate is 320, the moving contact is 400, the moving contact point is 410, the arc-starting tip is 420, the slit assembly is 500, the gas-generating plate is 510, the magnetizing plate is 520, the positioning hole is 530, and the arc-extinguishing plate is 600. Detailed Implementation
[0030] To make the objectives, technical solutions and advantages of this utility model clearer, the utility model will be described in further detail below with reference to the accompanying drawings.
[0031] It should be noted that all uses of "first" and "second" in the embodiments of this utility model are for the purpose of distinguishing two entities or parameters with the same name but different names. It is clear that "first" and "second" are only for the convenience of expression and should not be construed as limiting the embodiments of this utility model. Subsequent embodiments will not explain this in detail.
[0032] The directional and positional terms used in this utility model, such as up, down, front, back, left, right, inside, outside, top, bottom, side, etc., are only for reference to the accompanying drawings. Therefore, the directional and positional terms used are for the purpose of explaining and understanding this utility model, and not for limiting the scope of protection of this utility model.
[0033] Example 1:
[0034] A type of circuit breaker, such as Figure 1 , Figure 2 As shown, the circuit breaker includes a circuit breaker housing 100 and an arc-extinguishing chamber 200, a stationary contact 300, a moving contact 400, and a slit assembly 500 disposed within the circuit breaker housing. The circuit breaker housing 100 includes a bottom cover 120 and a top cover 130, which together form a cavity for fixing the arc-extinguishing chamber 200, the stationary contact 300, the moving contact 400, and the slit assembly 500. The arc-extinguishing chamber 200 is located at the bottom of the inner cavity of the circuit breaker housing 100, near the center.
[0035] Specifically, such as Figure 3 , Figure 4As shown, the arc-extinguishing chamber 200 includes two fixed plates 210 and a first arc-extinguishing grid plate group 220, a second arc-extinguishing grid plate group 230, and a third arc-extinguishing grid plate group 240, which are sequentially arranged between the two fixed plates 210. The first arc-extinguishing grid plate group 220 consists of a plurality of parallel first arc-extinguishing grid plates, which are arranged horizontally. The third arc-extinguishing grid plate group 240 consists of a plurality of parallel third arc-extinguishing grid plates, which are inclined at an angle α relative to the horizontal direction. The outlet end is inclined towards the second arc-extinguishing grid group 230, with α greater than 45° and less than 90°. The second arc-extinguishing grid group 230 is composed of several second arc-extinguishing grids, and the second arc-extinguishing grids and adjacent arc-extinguishing grids are arranged at an angle β, where the distance between the inlet end and the distance between the outlet end is smaller than the distance between the outlet end, with β greater than 0 and less than 15°. The circuit breaker housing is provided with a discharge port 110, which is located outside the outlet of the second arc-extinguishing grid group 230. An arc-extinguishing plate 600 is provided inside the discharge port 110 for extinguishing the arc. The stationary contact 310 of the stationary contact 300 and the moving contact 410 of the moving contact 400 are located in the area between the first arc-extinguishing grid group 220, the second arc-extinguishing grid group 230, and the third arc-extinguishing grid group 240. This embodiment achieves multi-stage, efficient segmentation and cooling of the arc through the coordinated operation of the three groups of arc-extinguishing grids, greatly shortening the arc-extinguishing time and improving the arc-extinguishing effect. In the arc-extinguishing chamber, the outlet end of the third arc-extinguishing grid group 240 is inclined towards the direction of the second arc-extinguishing grid group 230, and together with the second arc-extinguishing grid group 230, guides the arc to move towards the discharge outlet. The discharge outlet 110 on the circuit breaker housing 100 is located outside the outlet of the second arc-extinguishing grid group 230, so that the residual arc after arc extinguishing can be smoothly and quickly discharged from the circuit breaker housing, effectively avoiding the accumulation of residual arc in the housing, preventing internal faults caused by residual arc, and improving the safety and stability of circuit breaker operation. Furthermore, the second arc-extinguishing grid of the second arc-extinguishing grid group 230 is set at an angle β with the adjacent arc-extinguishing grid, with the inlet end distance being smaller than the outlet end distance, allowing the arc to pass through and be discharged more quickly.
[0036] The included angle β between the second arc-extinguishing grid and the adjacent arc-extinguishing grid can be equal or unequal. In this embodiment, the included angle β between the second arc-extinguishing grid and the adjacent arc-extinguishing grid is equal, specifically, β = 8°.
[0037] Furthermore, the inlet ends of the second arc-extinguishing grids in the second arc-extinguishing grid group 230 are arranged in a V-shape. This arrangement allows for a larger number of second arc-extinguishing grids to be arranged in the second arc-extinguishing grid group 230.
[0038] Furthermore, the inlet ends of the first arc-extinguishing grids of the first arc-extinguishing grid group 220 are inclined, and the inlet ends of the first arc-extinguishing grids on the side away from the second arc-extinguishing grid group 230 tend to be set towards the third arc-extinguishing grid group 240, so that the three groups of arc-extinguishing grids are arranged in a V-shape.
[0039] like Figure 4 As shown, the stationary contact 300 has a stationary contact point 310 located at the center of the third arc-extinguishing grid group 240. The moving contact 400 has a moving contact point 410 rotatably located on the side of the stationary contact 300 away from the first arc-extinguishing grid group 220. Further, the stationary contact 300 includes a first arc-inducing plate 320 extending to the side of the first arc-extinguishing grid group 220 away from the second arc-extinguishing grid group 230, with a 5mm-10mm gap between the first arc-inducing plate 320 and the first arc-extinguishing grid group 220. A second arc-inducing plate 250 is provided on the side of the third arc-extinguishing grid group 240 away from the second arc-extinguishing grid group 230, and the second arc-inducing plate 250 has an arc-inducing portion extending to the outside of the moving contact 400 located in the open position, away from the stationary contact 300. This forms a bidirectional arc-inducing effect and prevents the arc from dissipating outside the arc-extinguishing chamber.
[0040] The slit assembly 500 includes two gas-generating plates 510 disposed in the region between the first arc-extinguishing grid group 220, the second arc-extinguishing grid group 230, and the third arc-extinguishing grid group 240. A slit is formed between the two gas-generating plates 510 to accommodate the stationary contact 300 and the moving contact 400. The slit assembly 500 includes a magnetizing plate 520 fixed to the outside of the gas-generating plates 510. When the moving contact 400 rotates to open, the moving contact 410 separates from the stationary contact 310 to form an electric arc. The electric arc directly acts on the gas-generating plates 510, forming a blowing effect. The magnetizing plate 520 is disposed on the outside of the gas-generating plates 510 to enhance the arc-blowing magnetic field.
[0041] In this embodiment, 7. the slit assembly 500 is fixed to the inner wall of the circuit breaker housing 100. Specifically, as shown... Figure 6 , Figure 7 As shown, the bottom cover 120 and the upper cover 130 are provided with positioning posts 140 on their inner walls, and the slit assembly 500 is provided with positioning holes 530 at corresponding positions. The two work together to form a fixing effect.
[0042] Furthermore, the first and third arc-extinguishing grids have the same structure, both as follows: Figure 5 As shown, an venting groove 260 is provided at its outlet end, forming an venting channel between the first arc-extinguishing grid group 220, the third arc-extinguishing grid group 240 and the circuit breaker housing 100. The venting channel facilitates the discharge of the free arc generated by the first and third arc-extinguishing grid groups.
[0043] Example 2:
[0044] like Figure 8 As shown, the structure and layout of this embodiment are largely the same as those of Embodiment 1, with the only difference being the structure of the moving contact. Specifically, as shown... Figure 9 As shown, the moving contact 400 has an arc-initiating tip 420, which is located at the outer end of the moving contact 400 and its rotation path is outside the rotation path of the moving contact 410. The arc-initiating tip 420 and the moving contact 410 are located on opposite sides of the moving contact 400. The arc-initiating tip 420 causes the arc burning point to deflect towards the arc-initiating angle when the circuit breaker breaks the arc, thus protecting the moving contact and extending its lifespan.
[0045] The above-disclosed embodiments are merely preferred embodiments of the present utility model and should not be construed as limiting the scope of the present utility model. Therefore, any equivalent variations made in accordance with the claims of the present utility model shall still fall within the scope of the present utility model.
Claims
1. An arc-extinguishing structure for a circuit breaker, comprising a circuit breaker housing (100) and an arc-extinguishing chamber (200), a stationary contact (300), and a moving contact (400) disposed within the circuit breaker housing; characterized in that: The circuit breaker housing is provided with a drain port (110); The arc-extinguishing chamber (200) includes two fixed plates (210) and a first arc-extinguishing grid plate group (220), a second arc-extinguishing grid plate group (230), and a third arc-extinguishing grid plate group (240) arranged sequentially between the two fixed plates (210). The first arc-extinguishing grid plate group (220) consists of several parallel first arc-extinguishing grid plates, which are arranged in a horizontal direction; the third arc-extinguishing grid plate group (240) consists of several parallel third arc-extinguishing grid plates, which are inclined at an angle α relative to the horizontal direction and their outlet ends tend to be inclined towards the second arc-extinguishing grid plate group (230), where α is greater than 45° and less than 90°; the second arc-extinguishing grid plate group (230) consists of several second arc-extinguishing grid plates, which are arranged at an angle β between the second arc-extinguishing grid plates and adjacent arc-extinguishing grid plates, where the distance between the inlet end and the distance between the outlet end are less than 0° and less than 15°; The outlet (110) is located outside the outlet of the second arc-extinguishing grid assembly (230); The stationary contact (310) of the stationary contact (300) and the moving contact (410) of the moving contact (400) are located in the area between the first arc-extinguishing grid group (220), the second arc-extinguishing grid group (230), and the third arc-extinguishing grid group (240).
2. The arc-extinguishing structure of the circuit breaker according to claim 1, characterized in that: The angle β between the second arc-extinguishing grid and the adjacent arc-extinguishing grid is equal.
3. The arc-extinguishing structure of the circuit breaker according to claim 1, characterized in that: The inlet ends of the second arc-extinguishing grid plates of the second arc-extinguishing grid plate group (230) are arranged in a V-shape.
4. The arc-extinguishing structure of the circuit breaker according to claim 3, characterized in that: The inlet ends of the first arc-extinguishing grids of the first arc-extinguishing grid group (220) are inclined, and the inlet ends of the first arc-extinguishing grids on the side away from the second arc-extinguishing grid group (230) tend to be set towards the third arc-extinguishing grid group (240).
5. The arc-extinguishing structure of the circuit breaker according to any one of claims 1-4, characterized in that: The stationary contact (310) of the stationary contact (300) is disposed in the middle of the third arc-extinguishing grid plate group (240), and the moving contact (410) of the moving contact (400) is rotatably disposed on the side of the stationary contact (300) away from the first arc-extinguishing grid plate group (220).
6. The arc-extinguishing structure of the circuit breaker according to claim 5, characterized in that: It also includes a slit assembly (500), which includes two gas-generating plates (510) disposed in the region between the first arc-extinguishing grid group (220), the second arc-extinguishing grid group (230) and the third arc-extinguishing grid group (240), and a slit is formed between the two gas-generating plates (510) to accommodate a stationary contact (300) and a moving contact (400); the slit assembly (500) includes a magnetizing plate (520) fixed to the outside of the gas-generating plates (510).
7. The arc-extinguishing structure of the circuit breaker according to claim 6, characterized in that: The slit assembly (500) is fixed to the inner wall of the circuit breaker housing (100).
8. The arc-extinguishing structure of the circuit breaker according to claim 5, characterized in that: The stationary contact (300) includes a first arc-inducing plate (320) extending to the side of the first arc-extinguishing grid group (220) away from the second arc-extinguishing grid group (230), with a 5mm-10mm gap between the first arc-inducing plate (320) and the first arc-extinguishing grid group (220); a second arc-inducing plate (250) is provided on the side of the third arc-extinguishing grid group (240) away from the second arc-extinguishing grid group (230), and the second arc-inducing plate (250) is provided with an arc-inducing portion extending to the outside of the moving contact (400) located in the open position away from the stationary contact (300).
9. The arc-extinguishing structure of the circuit breaker according to claim 8, characterized in that: The moving contact (400) has an arc-inducing tip (420), which is located at the outer end of the moving contact (400) and its rotation path is outside the rotation path of the moving contact (410). The arc-inducing tip (420) and the moving contact (410) are located on both sides of the moving contact (400).
10. The arc-extinguishing structure of the circuit breaker according to any one of claims 1-4, characterized in that: The outlet ends of the first and third arc-extinguishing grid plates are provided with venting grooves (260) to form venting channels between the first arc-extinguishing grid plate group (220), the third arc-extinguishing grid plate group (240) and the circuit breaker housing (100).