An arc extinguishing mechanism for a miniature circuit breaker
By setting vent holes and heat dissipation grooves on both sides of the arc-extinguishing chamber, combined with the arc-starting plate and the arc-shaped magnetic guide plate, the problem of poor heat dissipation in the arc-extinguishing chamber of miniature circuit breakers is solved, enabling faster heat dissipation and ensuring the stable operation of the circuit breaker.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHANGHAI YONGJI ELECTRICAL HLDG
- Filing Date
- 2025-07-25
- Publication Date
- 2026-07-31
AI Technical Summary
The arc-extinguishing chamber of a miniature circuit breaker has poor heat dissipation, which affects its normal operation.
Multiple first exhaust holes are set on both sides of the arc-extinguishing chamber, and heat dissipation grooves are opened on the top cover and base to form a heat dissipation channel connected with the arc-blocking plate. Combined with the arc-initiating plate and the arc-shaped magnetic guide plate, the electric arc is guided into the arc-extinguishing chamber and the heat is discharged through the exhaust holes.
It improves the heat dissipation efficiency of the arc-extinguishing chamber, prevents overheating damage, and ensures the normal operation of the circuit breaker.
Smart Images
Figure CN224582237U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of circuit breaker technology, and in particular to an arc extinguishing mechanism for a miniature circuit breaker. Background Technology
[0002] When the contacts of a miniature circuit breaker separate and generate an electric arc, the arc is extinguished by the arc-extinguishing chamber. After entering the arc-extinguishing chamber, the arc is first cut by the arc-extinguishing grid. The grid divides the long arc into multiple short arcs, each with a higher voltage, making it easier to extinguish. Simultaneously, the arc is cooled inside the arc-extinguishing chamber. The gas inside (usually air) absorbs heat from the arc, and as its temperature rises, it is expelled from the exhaust port, creating convection that carries away a significant amount of heat, thus lowering the arc temperature. However, due to size limitations, the heat dissipation effect of the arc-extinguishing chamber is often poor, which is detrimental to the normal operation of the miniature circuit breaker. Utility Model Content
[0003] To solve the above-mentioned technical problems, this utility model provides an arc-extinguishing mechanism for a miniature circuit breaker with better heat dissipation.
[0004] The present invention adopts the following technical solution:
[0005] This utility model provides an arc-extinguishing mechanism for a miniature circuit breaker, including a base, a top cover, an arc-extinguishing chamber, a stationary contact, and a moving contact. The top cover is fastened to the base to form a shell. The arc-extinguishing chamber is disposed inside the shell and has multiple first vent holes through its two sides facing the top cover and the base. Multiple heat dissipation grooves are provided on the top cover and the base, and each first vent hole is connected to a corresponding heat dissipation groove. An arc-blocking plate is installed on both the top cover and the base near the arc-extinguishing chamber. The two arc-blocking plates are arranged in parallel and form an arc-blocking cavity that communicates with the arc-extinguishing chamber. The stationary contact is fixed inside the arc-blocking cavity, and the moving contact is disposed inside the shell and can contact or separate from the stationary contact.
[0006] Preferably, the heat dissipation grooves of the top cover and the base extend in a straight line towards the direction of their respective arc-blocking plates, and the heat dissipation grooves of the top cover and the base are spaced apart from the side of their respective arc-blocking plates away from the arc-blocking cavity to form a unique air vent.
[0007] Preferably, the arc-extinguishing chamber includes an arc-extinguishing cover and arc-extinguishing grid plates. Multiple arc-extinguishing grid plates are arranged in parallel and spaced apart inside the arc-extinguishing cover. The first exhaust holes are located on the two sides of the arc-extinguishing cover facing the upper cover and the base. Two adjacent arc-extinguishing grid plates form an arc-extinguishing grid plate group, and there is a first exhaust hole between two adjacent arc-extinguishing grid plate groups.
[0008] Preferably, the stationary contact is provided with an arc-inducing angle, the tail end of which is bent and extends into the V-shaped notch of the arc-extinguishing grid.
[0009] Preferably, the arc-initiating plate and the arc-shaped magnetic guide plate are provided inside the arc-isolating cavity. The arc center of the arc-initiating plate faces the stationary contact and is spaced apart from the stationary contact. The arc-shaped magnetic guide plate is concentric with the arc-initiating plate and fits against the arc surface of the arc-initiating plate away from the stationary contact.
[0010] Preferably, the arc-extinguishing cover has multiple second exhaust holes on the side opposite to the arc-isolating cavity, and there are second exhaust holes between the two arc-extinguishing grids of the arc-extinguishing grid group.
[0011] Preferably, a first baffle, a second baffle, and a third baffle are provided on the side of the arc extinguishing cover away from the arc isolation cavity. The first baffle extends in a straight line perpendicular to the side of the arc extinguishing cover, and the second baffle and the third baffle are located on both sides of the first baffle, and both the second baffle and the third baffle extend in a straight line at an angle away from the first baffle.
[0012] Compared with the prior art, the beneficial effects of this utility model are as follows:
[0013] When the arc-extinguishing mechanism of the miniature circuit breaker of this utility model is in use, the moving contact separates from the stationary contact to generate an electric arc. The electric arc is quickly drawn into the arc-extinguishing chamber by the two arc-blocking plates in the arc-blocking cavity for arc extinguishing. The large amount of heat generated during the arc extinguishing process enters the heat dissipation groove from the first exhaust hole, thereby increasing the heat dissipation area near the arc-extinguishing chamber and allowing the heat to be dissipated to the surrounding environment more quickly. This reduces the temperature of the arc-extinguishing chamber, prevents damage to the components inside the arc-extinguishing chamber due to overheating, and ensures the normal operation of the miniature circuit breaker. Attached Figure Description
[0014] Figure 1 This is a schematic diagram of the housing structure on the arc-extinguishing mechanism of a miniature circuit breaker in an embodiment of this utility model.
[0015] Figure 2 This is a schematic diagram of the arc-extinguishing mechanism of a miniature circuit breaker after the top cover has been removed, according to an embodiment of this utility model.
[0016] Figure 3 This is a schematic diagram of the structure of the base of the arc extinguishing mechanism of the miniature circuit breaker in an embodiment of this utility model.
[0017] Figure 4 This is a schematic diagram of the structure of the upper cover of the arc-extinguishing mechanism of the miniature circuit breaker in this embodiment of the present invention.
[0018] Figure 5 This is a schematic diagram of the arc-extinguishing cover on the arc-extinguishing mechanism of a miniature circuit breaker in this embodiment of the present invention.
[0019] The reference numerals in the attached figures are explained as follows:
[0020] 1. Shell 206, Third baffle
[0021] 101. Base 3. Stationary contact
[0022] 102, Top Cover 301, Arc Angle
[0023] 2. Arc-extinguishing chamber; 4. Moving contact
[0024] 201, First exhaust port 5, Heat dissipation groove
[0025] 202. Arc extinguishing shield; 6. Arc isolation plate
[0026] 203, Second vent hole; 7, Arc-starting plate
[0027] 204. First baffle; 8. Arc-shaped magnetic guide plate
[0028] 205. Second baffle Detailed Implementation
[0029] The specific embodiments of this utility model will be further described in detail below with reference to the accompanying drawings. These embodiments are only used to illustrate this utility model and are not intended to limit it.
[0030] In the description of this utility model, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this utility model. In addition, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.
[0031] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.
[0032] Furthermore, in the description of this utility model, unless otherwise stated, "a plurality of" means two or more.
[0033] See Figure 1 , Figure 2 and Figure 3This embodiment provides an arc-extinguishing mechanism for a miniature circuit breaker, including a base 101, a top cover 102, an arc-extinguishing chamber 2, a stationary contact 3, and a moving contact 4. The top cover 102 is fastened to the base 101 to form a housing 1. The arc-extinguishing chamber 2 is disposed inside the housing 1 and has multiple first exhaust holes 201 extending through its two sides facing the top cover 102 and the base 101. Multiple heat dissipation grooves 5 are respectively provided on the top cover 102 and the base 101. Each first exhaust hole 201 is connected to a corresponding heat dissipation groove 5. An arc-blocking plate 6 is installed on both the top cover 102 and the base 101 near the arc-extinguishing chamber 2. The two arc-blocking plates 6 are arranged in parallel and form an arc-blocking cavity that communicates with the arc-extinguishing chamber 2. The stationary contact 3 is fixed inside the arc-blocking cavity, and the moving contact 4 is disposed inside the housing 1 and can contact or separate from the stationary contact 3.
[0034] In this embodiment, the arc-extinguishing mechanism of the miniature circuit breaker generates an electric arc when the moving contact 4 separates from the stationary contact 3. The arc is quickly drawn into the arc-extinguishing chamber 2 by the two arc-blocking plates 6 in the arc-blocking cavity for arc extinguishing. The large amount of heat generated during the arc extinguishing process enters the heat dissipation groove 5 from the first exhaust hole 201, thereby increasing the heat dissipation area near the arc-extinguishing chamber 2 and allowing the heat to be dissipated to the surrounding environment more quickly. This reduces the temperature of the arc-extinguishing chamber 2, prevents damage to the components inside the arc-extinguishing chamber 2 due to overheating, and ensures the normal operation of the miniature circuit breaker.
[0035] Preferably, see Figure 2 , Figure 3 and Figure 4 The heat dissipation groove 5 of the upper cover 102 and the heat dissipation groove 5 of the base 101 both extend in a straight line in the direction of their respective arc-blocking plates 6, and the heat dissipation groove 5 of the upper cover 102 and the heat dissipation groove 5 of the base 101 are spaced apart from the side of their respective arc-blocking plates 6 away from the arc-blocking cavity to form a unique air vent.
[0036] The heat dissipation groove 5 is designed in this way to optimize the airflow field around the arc-extinguishing chamber 2. When the electric arc enters the arc-extinguishing chamber 2, it generates high-temperature and high-pressure gas. Guided by the linearly extending heat dissipation groove 5, this gas can flow more orderly, promoting the cooling and extinguishing of the arc. At the same time, the good airflow field also helps to remove harmful substances such as metal vapor generated by the arc from the arc-extinguishing chamber 2, reducing their impact on the arc-extinguishing process.
[0037] Preferably, see Figure 5 The arc-extinguishing chamber 2 includes an arc-extinguishing cover 202 and arc-extinguishing grids (not shown in the figure). Multiple arc-extinguishing grids are arranged in parallel and spaced apart inside the arc-extinguishing cover 202. The first exhaust port 201 is located on both sides of the arc-extinguishing cover 202 facing the upper cover 102 and the base 101. Two adjacent arc-extinguishing grids form an arc-extinguishing grid group. There is a first exhaust port 201 between two adjacent arc-extinguishing grid groups to discharge the high-temperature and high-pressure gas between the two adjacent arc-extinguishing grid groups through the first exhaust port 201.
[0038] Preferably, see Figure 2 The stationary contact 3 is provided with an arc-starting angle 301. The tail end of the arc-starting angle 301 is bent and extended into the V-shaped notch of the arc-extinguishing grid plate so as to guide the arc direction through the arc-starting angle 301, so that it develops along the inlet direction of the arc-extinguishing chamber 2 and quickly enters the arc-extinguishing chamber 2, thereby improving the arc-extinguishing effect.
[0039] Preferably, see Figure 2 An arc-inducing plate 7 and an arc-shaped magnetic guide plate 8 are provided inside the arc-isolating cavity. The arc center of the arc-inducing plate 7 faces the stationary contact 3 and is spaced apart from the stationary contact 3. The arc-shaped magnetic guide plate 8 is concentric with the arc-inducing plate 7 and fits against the arc surface of the arc-inducing plate 7 away from the stationary contact 3.
[0040] When the moving contact 4 separates from the stationary contact 3, the arc-initiating plate 7 can quickly guide the arc towards the arc-extinguishing chamber 2, ensuring the arc accurately enters the arc-extinguishing chamber 2 and guaranteeing the stability of the arc-extinguishing process. Meanwhile, the arc-shaped magnetic plate 8 can concentrate and guide the magnetic field to generate a magnetic blowing force on the arc, causing it to move into the arc-extinguishing chamber 2 and accelerating its entry. Clearly, the synergistic effect of the arc-initiating plate 7 and the arc-shaped magnetic plate 8 ensures that the arc can quickly and accurately enter the arc-extinguishing chamber 2 and be effectively extinguished.
[0041] Preferably, see Figure 5 The arc-extinguishing cover 202 has multiple second exhaust holes 203 on its side away from the arc-isolating cavity. These second exhaust holes 203 are located between two arc-extinguishing grids in the arc-extinguishing grid assembly, allowing the high-temperature, high-pressure gas inside the arc-extinguishing grid assembly to be discharged. Furthermore, the second exhaust holes 203 are staggered from the first exhaust holes 201, ensuring efficient heat dissipation between adjacent arc-extinguishing grid assemblies and within a single arc-extinguishing grid assembly.
[0042] Preferably, see Figure 2 and Figure 5 The arc extinguishing cover 202 is provided with a first baffle 204, a second baffle 205 and a third baffle 206 on the side away from the arc isolation cavity. The first baffle 204 extends in a straight line perpendicular to the side of the arc extinguishing cover 202. The second baffle 205 and the third baffle 206 are located on both sides of the first baffle 204, and both the second baffle 205 and the third baffle 206 extend in a straight line at an angle away from the first baffle 204.
[0043] The arrangement of the first baffle 204, the second baffle 205, and the third baffle 206 can guide the high-temperature and high-pressure gas in the arc-extinguishing grid assembly to be discharged regularly from the second exhaust port 203, avoiding disorderly diffusion of the gas and making the gas flow smoother. At the same time, the inclined second baffle 205 and the third baffle 206 can guide the metal vapor to be discharged from the second exhaust port 203 together with the high-temperature and high-pressure gas, reducing the accumulation of metal vapor inside the arc-extinguishing chamber 2 and preventing the metal vapor from re-condensing on the components inside the arc-extinguishing chamber 2, which would affect the insulation performance and arc-extinguishing effect of the arc-extinguishing chamber 2.
[0044] It should be noted that multiple second baffles 205 and third baffles 206 can be set at intervals according to actual needs.
[0045] Better yet, see Figure 3 and Figure 4 In this embodiment, a first baffle 204, a second baffle 205, and two third baffles 206 are fixed on the base 101; a first baffle 204, a second baffle 205, and two third baffles 206 are also fixed on the upper cover 102, and the first baffle 204, the second baffle 205, and the third baffle 206 are all arranged one-to-one at the position of the second exhaust hole 203 to improve the gas guiding effect.
[0046] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of the present utility model, and these improvements and substitutions should also be considered within the protection scope of the present utility model.
Claims
1. An arc extinguishing mechanism for a miniature circuit breaker, characterized by The device includes a base (101), a top cover (102), an arc-extinguishing chamber (2), a stationary contact (3), and a moving contact (4). The top cover (102) is fastened to the base (101) to form a housing (1). The arc-extinguishing chamber (2) is disposed inside the housing (1) and has multiple first exhaust holes (201) penetrating on both sides facing the top cover (102) and the base (101). Multiple heat dissipation grooves (5) are respectively provided on the top cover (102) and the base (101). Each of the first exhaust holes (201) is connected to a heat dissipation groove (5). The upper cover (102) and the base (101) are each equipped with an arc-blocking plate (6) near the arc-extinguishing chamber (2). The two arc-blocking plates (6) are arranged in parallel and form an arc-blocking cavity connected to the arc-extinguishing chamber (2). The stationary contact (3) is fixed in the arc-blocking cavity. The moving contact (4) is arranged in the housing (1) and can contact or separate from the stationary contact (3).
2. The arc quenching mechanism of a miniature circuit breaker according to claim 1, characterized in that, The heat dissipation groove (5) of the upper cover (102) and the heat dissipation groove (5) of the base (101) both extend in a straight line in the direction of their respective arc-blocking plates (6), and the heat dissipation groove (5) of the upper cover (102) and the heat dissipation groove (5) of the base (101) are spaced apart from the side of their respective arc-blocking plates (6) away from the arc-blocking cavity to form a unique air vent.
3. The arc quenching mechanism of a miniature circuit breaker according to claim 1, characterized in that, The arc-extinguishing chamber (2) includes an arc-extinguishing cover (202) and arc-extinguishing grids. A plurality of arc-extinguishing grids are arranged in parallel and spaced apart inside the arc-extinguishing cover (202). The first exhaust hole (201) is arranged on both sides of the arc-extinguishing cover (202) facing the upper cover (102) and the base (101). Two adjacent arc-extinguishing grids form an arc-extinguishing grid group, and the first exhaust hole (201) exists between two adjacent arc-extinguishing grid groups.
4. The arc quenching mechanism of a miniature circuit breaker according to claim 3, characterized in that, The stationary contact (3) is provided with an arc-inducing angle (301), the tail end of which is bent and extends into the V-shaped notch of the arc-extinguishing grid.
5. The arc quenching mechanism of a miniature circuit breaker according to claim 4, characterized in that, The arc-isolating cavity is provided with an arc-inducing plate (7) and an arc-shaped magnetic guide plate (8). The arc center of the arc-inducing plate (7) faces the stationary contact (3) and is spaced apart from the stationary contact (3). The arc-shaped magnetic guide plate (8) is concentric with the arc-inducing plate (7) and fits against the arc surface of the arc-inducing plate (7) away from the stationary contact (3).
6. The arc quenching mechanism of a miniature circuit breaker according to claim 3, characterized in that, The arc-extinguishing cover (202) has multiple second exhaust holes (203) on its side away from the arc-isolating cavity, and the second exhaust holes (203) are located between the two arc-extinguishing grid plates of the arc-extinguishing grid plate group.
7. The arc quenching mechanism of a miniature circuit breaker according to claim 6, characterized in that, The arc-extinguishing cover (202) is provided with a first baffle (204), a second baffle (205) and a third baffle (206) on the side away from the arc-isolating cavity. The first baffle (204) extends in a straight line perpendicular to the side of the arc-extinguishing cover (202). The second baffle (205) and the third baffle (206) are located on both sides of the first baffle (204), and both the second baffle (205) and the third baffle (206) extend in a straight line at an angle away from the first baffle (204).