A circuit breaker

Abstract

The application relates to a circuit breaker, comprising a base, a mechanism, a contact assembly and an arc extinguishing chamber, the arc extinguishing chamber is arranged on one side of the contact assembly, the contact assembly comprises a static contact with a static contact point and a moving contact with a moving contact point, the moving contact has a moving stroke relative to the static contact to realize the on or off of the circuit breaker, the mechanism is connected with the moving contact in linkage, a gas running path for gas blow-out arc extinguishing is formed from the contact assembly to the arc extinguishing chamber, a gas blocking plate is attached to the moving contact or the mechanism and moves along with the movement of the moving contact, when the moving contact is off relative to the static contact, the gas blocking plate follows the moving stroke of the moving contact to block the upstream of the gas running path, so that most of the gas generated by the arc between the moving contact and the static contact can move towards the arc extinguishing chamber and accelerate the pushing of the arc into the arc extinguishing chamber.

Description

Technical Field

[0001] This invention relates to the field of low-voltage switchgear, and more specifically to improvements in arc-extinguishing functions. Background Technology

[0002] When the moving and stationary contacts of a circuit breaker open, the initial distance between them is small, while the electric field strength is high, resulting in an electric arc between them. If the arc is not extinguished, the circuit cannot be completely disconnected, and the arc temperature is very high, which can damage equipment and cause serious accidents. Therefore, the arc-extinguishing system of the circuit breaker is crucial for timely arc extinguishing. Among current methods, gas blowing is a highly effective auxiliary arc-extinguishing technique. It utilizes the arc to ablate the gas-generating material, producing a large amount of gas, which propels the arc into the arc-extinguishing chamber, thus accelerating the extinguishing process. However, in existing technologies, the moving and stationary contact areas of circuit breakers are often open. When a large amount of gas is generated in these areas, it can easily disperse to other parts of the circuit breaker's internal cavity, reducing the effectiveness of gas blowing. Summary of the Invention

[0003] Therefore, in order to address the above problems, this invention proposes a circuit breaker with optimized structure, which uses a baffle plate to partially enclose the contact area of ​​the circuit breaker, thereby promoting the flow of gas generated by the electric arc into the arc-extinguishing chamber.

[0004] This invention is achieved using the following technical solution:

[0005] This invention proposes a circuit breaker, comprising a base, a mechanism, a contact assembly, and an arc-extinguishing chamber. The arc-extinguishing chamber is disposed on one side of the contact assembly. The contact assembly includes a stationary contact with a stationary contact and a moving contact with a moving contact. The moving contact has a movable stroke relative to the stationary contact to realize the circuit breaker's connection or disconnection. The mechanism is linked to the moving contact, forming a gas travel path for gas blowing arc extinguishing from the contact assembly to the arc-extinguishing chamber. A baffle plate is attached to the moving contact or the mechanism, which moves with the movement of the moving contact. When the moving contact disconnects relative to the stationary contact, the baffle plate moves along the movable contact's movable stroke to block the upstream of the gas travel path.

[0006] In order to further ensure that most of the large amount of gas generated by the electric arc between the moving and stationary contacts can move toward the arc-extinguishing chamber, in one embodiment, the base preferably includes a first sidewall and a second sidewall, and the contact assembly and the baffle plate are sandwiched between the first sidewall and the second sidewall. The first sidewall, the second sidewall and the baffle plate form a U-shaped semi-enclosed space with the opening facing the arc-extinguishing chamber.

[0007] In order to accelerate the movement of gas toward the arc-extinguishing chamber and improve the arc-extinguishing effect, in one embodiment, the relative surrounding surfaces of the first and second sidewalls corresponding to the contact assembly are preferably inclined downwards, and the two relative surrounding surfaces form a gas pressurization channel that gradually expands from the contact assembly to the arc-extinguishing chamber between the first and second sidewalls.

[0008] In order to prevent the components of the main circuit from being severely damaged due to excessive heat caused by the electric arc energy, and to avoid the moving contact being continuously burned, in one embodiment, a moving arc-initiating plate is preferably included. One end of the moving arc-initiating plate is located downstream of the gas travel path and close to the moving contact, and the other end is connected to the moving contact at the same potential.

[0009] Preferably, the width of the movable arc-inducing plate at the downstream end of the gas travel path is smaller than the distance between the first sidewall and the second sidewall, so that one end of the movable arc-inducing plate has an air gap with the first sidewall and / or the second sidewall.

[0010] Preferably, the stationary contact has a stationary arc-leading portion extending into the arc-extinguishing chamber, and a convex bulge is provided between the stationary contact and the stationary arc-leading portion to serve as an intermediate transition node for the arc, guiding the arc at one end of the stationary contact to the stationary arc-leading portion.

[0011] Preferably, the baffle plate is made of an insulating gas-generating material.

[0012] Preferably, the main body of the baffle plate is an arc-shaped plate structure, and a pin is fixedly provided on the mechanism. The baffle plate and the moving contact are rotatably connected to the mechanism by clearance fit with the pin through their respective shaft holes. An arc-shaped slide rail is also provided on the base, and the baffle plate slides in the slide rail.

[0013] The present invention has the following beneficial effects: By setting up a baffle plate, the present invention can block the upstream space of the gas path for the gas blowing to extinguish the arc, ensuring that most of the large amount of gas generated by the arc between the moving and stationary contacts can move towards the arc-extinguishing chamber, accelerating the arc into the arc-extinguishing chamber, reducing the arc burning time, lowering the energy generated by the short-circuit arc, and improving the short-circuit capacity of the circuit breaker. At the same time, the baffle plate can also prevent the arc from back-jetting and burning the main spring and mechanism, thus preventing material ablation or adhesion caused by component adhesion, which ultimately leads to problems such as the product's opening and closing movement being unsmooth or unable to open and close after experiencing short-circuit current. Attached Figure Description

[0014] Figure 1 This is a front view of the internal structure of the circuit breaker in the embodiment;

[0015] Figure 2 This is a perspective view of the internal structure of the circuit breaker in the embodiment;

[0016] Figure 3 This is a front view of the circuit breaker as a whole in the embodiment;

[0017] Figure 4 yes Figure 3 Sectional view at point AA;

[0018] Figure 5 yes Figure 3 Sectional view at point BB;

[0019] Figure 6 This is an assembly drawing (angle 1) of the moving contact, baffle plate and mechanism in the embodiment;

[0020] Figure 7 This is an assembly drawing (angle two) of the moving contact, baffle plate and mechanism in the embodiment;

[0021] Figure 8 This is an exploded view of the moving contact, baffle plate, and mechanism in the embodiment;

[0022] Figure 9 This is a schematic diagram of the air baffle slidingly fitted within the slide rail in the embodiment;

[0023] Figure 10 yes Figure 9 A magnified view of a section at point D;

[0024] Figure 11 yes Figure 9 Sectional view at point CC. Detailed Implementation

[0025] To further illustrate the various embodiments, the present invention provides accompanying drawings. These drawings are part of the disclosure of the present invention, primarily used to illustrate the embodiments and to explain the operating principles of the embodiments in conjunction with the relevant descriptions in the specification. With reference to these drawings, those skilled in the art should be able to understand other possible implementations and the advantages of the present invention. Components in the drawings are not drawn to scale, and similar component symbols are generally used to represent similar components.

[0026] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments.

[0027] See Figure 1-5As shown, in a preferred embodiment of the present invention, a circuit breaker is provided, including a base 1, a mechanism 2, a moving contact 3, a stationary contact 4, and an arc-extinguishing chamber 6. The base 1, which serves as the circuit breaker housing, has an inner mounting cavity in which the mechanism 2, moving contact 3, stationary contact 4, and arc-extinguishing chamber 6 are installed. The circuit breaker also includes components such as a handle and a trip unit to realize the basic functions of the circuit breaker. The moving contact 3 and the stationary contact 4 form the contact assembly of the circuit breaker. The moving contact 3 has a moving contact 31, and the stationary contact 4 has a stationary contact 41. The moving contact 3 has a movable stroke relative to the stationary contact 4, through which the moving contact 31 and the stationary contact 41 make contact or separate, thereby realizing the connection or disconnection of the circuit breaker. The arc-extinguishing chamber 6 is located on one side of the contact assembly and is used to extinguish the arc generated between the moving contact 3 and the stationary contact 4 due to disconnection. The mechanism 2 and the moving contact 3 are linked together to cooperate with the handle, trip unit, etc., to realize the opening of the circuit breaker. Among them, a gas travel path for gas blowing to extinguish arc is formed from the contact assembly to the arc-extinguishing chamber 6. That is, when the moving contact 3 and the stationary contact 4 break, an electric arc occurs, a large amount of gas is generated from the area between the moving contact 3 and the stationary contact 4, and the gas is blown from the contact assembly to the arc-extinguishing chamber 6. This is the gas travel path described above.

[0028] A baffle plate 5 is attached to the mechanism 2. When the moving contact 3 moves, the baffle plate 5 on the mechanism 2 also moves accordingly. During the opening movement of the moving contact 3, the baffle plate 5 can block the upstream of the gas travel path by following the movement stroke of the moving contact 3, preventing a large amount of gas generated by the electric arc in the contact assembly area from rushing out in the opposite direction to the arc-extinguishing chamber 6. This ensures that the gas pressure between the moving contact 31 and the stationary contact 41 is high, and most of the gas can move towards the arc-extinguishing chamber 6, accelerating the electric arc into the arc-extinguishing chamber 6, reducing the arc burning time, reducing the energy generated by the short-circuit arc, and improving the short-circuit capacity of the circuit breaker. At the same time, the baffle plate 5 can also prevent the material from being burned or stuck due to the reverse jet of the arc burning the main spring and the mechanism 2, avoiding the problem of parts sticking and ultimately causing the product to have a rough opening and closing movement or be unable to open or close after experiencing a short-circuit current.

[0029] See Figure 4 , 5The base 1 includes a first sidewall 11 and a second sidewall 12. The contact assembly and the baffle plate 5 are sandwiched between the first sidewall 11 and the second sidewall 12, thereby forming a U-shaped semi-enclosed space with an opening facing the arc-extinguishing chamber 6. This further ensures that most of the large amount of gas generated between the moving and stationary contacts due to the electric arc can move towards the arc-extinguishing chamber 6. Furthermore, in this embodiment, the relative enclosing surfaces of the first sidewall 11 and the second sidewall 12 corresponding to the contact assembly are inclined slopes. The two relative enclosing surfaces form a gas pressurization channel that gradually expands from the contact assembly to the arc-extinguishing chamber 6 between the first sidewall 11 and the second sidewall 12, thereby accelerating the movement of gas towards the arc-extinguishing chamber 6 and improving the arc-extinguishing effect.

[0030] In this embodiment, the contact assembly and the arc-extinguishing chamber 6 are arranged opposite to each other. The gas traveling from the contact assembly to the arc-extinguishing chamber 6 travels almost straight towards the arc-extinguishing chamber 6. In other embodiments, a bent gas channel can be provided between the contact assembly and the arc-extinguishing chamber 6 to guide the gas. This design allows for more flexible design of the relative positions of the contact assembly and the arc-extinguishing chamber 6, but the gas speed will be reduced in the bent gas channel. Therefore, this embodiment preferably adopts a structural layout in which the contact assembly and the arc-extinguishing chamber 6 are arranged opposite to each other.

[0031] In this embodiment, the gas baffle 5 is made of insulating gas-generating materials such as nylon, melamine, and PA46, so that the gas baffle 5 can also generate a large amount of gas under the high temperature burning of the electric arc, thereby enhancing the gas blowing arc extinguishing function.

[0032] In this embodiment, the moving contact 3 has a swinging motion, such as... Figure 6-8 The air baffle 5 has an arc-shaped plate structure. A pin 32 is fixedly mounted on the mechanism 2. Both the moving contact 3 and the air baffle 5 are rotatably connected to the mechanism 2 through their respective shaft holes that are clearance-fitted with the pin 32. Figure 9-11An arc-shaped slide rail 10 matching the arc-shaped extension of the baffle plate 5 is also provided on the base 1, and the baffle plate 5 slides within the slide rail 10. The baffle plate 5 has a certain movement gap within the slide rail 10. When the moving contact 3 swings, the linkage mechanism 2 drives the baffle plate 5 to move, and the slide rail 10 effectively limits the movement path of the baffle plate 5, ensuring that the baffle plate 5 can form a relatively tight sealing effect on the upstream of the gas travel path during the entire opening swing stroke of the moving contact 3. As a plate-shaped structure, the baffle plate 5 occupies very little space while ensuring a sealing effect, which is beneficial for making room for the installation of the mechanism 2. In this embodiment, the baffle plate 5 is attached to the mechanism 2 by the above assembly method, which can also simplify the installation process of the baffle plate 5 and improve the assembly efficiency. In other embodiments, the baffle plate 5 can also be fixedly connected to the mechanism 2 or the moving contact 3, as long as the baffle plate 5 can follow the movement stroke of the moving contact 3. In this embodiment, the baffle plate 5 is also provided with reinforcing ribs 51 to increase the rigidity of the baffle plate 5.

[0033] like Figure 1 The stationary contact 4 has a stationary arc-inducing portion 42 extending towards the arc-extinguishing chamber 6. A protrusion 7 is provided between the stationary contact 41 and the stationary arc-inducing portion 42. The protrusion 7 can serve as an intermediate arc-inducing node (stepping plate), which can quickly guide the arc at one end of the stationary contact 41 downward to the stationary arc-inducing portion 42. The circuit breaker also includes a moving arc-inducing plate 8. One end of the moving arc-inducing plate 8 is located downstream of the gas travel path and close to the moving contact 3. The other end is electrically connected to the terminal 9 to achieve equipotential connection between the moving arc-inducing plate 8 and the moving contact 3. When an arc is generated, under the blowing of gas, the moving arc-inducing plate 8, which is downstream of the gas travel path, receives one end of the arc that jumps downward, thereby preventing the main circuit components (such as bimetallic and electromagnetic trip coils) from being severely damaged due to excessive arc energy and heat, and also preventing the moving contact 3 from being continuously burned. Specifically, in this embodiment, the moving arc-initiating plate 8 is provided with a V-shaped bend 81 at one end near the moving contact 3. The tip of the V-shaped bend 81 and the stationary arc-initiating part 42 are respectively located on both sides of the arc-extinguishing chamber 6. In the broken state, the tip of the V-shaped bend 81 is close to the line connecting the moving contact 3 and the stationary arc-initiating part 42. Thus, when one end of the arc runs to the stationary arc-initiating part 42, since the arc between the moving contact 3 and the stationary arc-initiating part 42 is very close to the tip of the V-shaped bend 81, the other end of the arc can quickly jump to the tip of the V-shaped bend 81 and continue to run, so that the arc energy of the moving contact 3 and the main circuit disappears or decreases. During the arc-running process guided by the stationary arc-initiating part 42 and the moving arc-initiating plate 8, the arc can be quickly elongated and enter the arc-extinguishing chamber 6 for arc extinguishing.

[0034] like Figure 2In this embodiment, the width of the moving arc-initiating plate 8 at the downstream end of the gas travel path is smaller than the distance between the first sidewall 11 and the second sidewall 12. Thus, the moving arc-initiating plate 8 at the downstream end of the gas travel path has an air gap with the first sidewall 11 and / or the second sidewall 12, which will not have a significant obstruction effect on the airflow, ensuring that the airflow can blow towards the arc-extinguishing chamber 6 and drive the arc to be extinguished in the arc-extinguishing chamber 6.

[0035] Although the invention has been specifically shown and described in conjunction with preferred embodiments, those skilled in the art should understand that various changes in form and detail made to the invention without departing from the spirit and scope of the invention as defined in the appended claims fall within the protection scope of the invention.

Claims

1. A circuit breaker, comprising a base, a mechanism, a contact assembly, and an arc-extinguishing chamber, wherein the contact assembly includes a stationary contact with a stationary contact and a moving contact with a moving contact, the moving contact having a travel relative to the stationary contact to realize the circuit breaker's connection or disconnection, the mechanism being linked to the moving contact, forming a gas travel path for gas-blown arc extinguishing from the contact assembly to the arc-extinguishing chamber, characterized in that: A baffle plate is attached to the moving contact or mechanism, which moves in tandem with the movement of the moving contact. When the moving contact separates from the stationary contact, the baffle plate, moving along the stroke of the moving contact, blocks the upstream of the gas path. The air baffle plate has an arc-shaped plate structure and is configured to be rotatable. An arc-shaped slide rail is also provided on the base, and the air baffle plate slides within the slide rail. A pin is fixedly provided on the mechanism, and the baffle plate and the moving contact are rotatably connected to the mechanism by clearance fit with the pin through their respective shaft holes.

2. The circuit breaker according to claim 1, characterized in that: The base includes a first sidewall and a second sidewall, and the contact assembly and the baffle plate are sandwiched between the first sidewall and the second sidewall. The first sidewall, the second sidewall and the baffle plate form a U-shaped semi-enclosed space with an opening facing the arc-extinguishing chamber.

3. The circuit breaker according to claim 2, characterized in that: The first and second sidewalls are inclined slopes corresponding to the relative surrounding surfaces of the contact assembly, and the two relative surrounding surfaces form a gas pressurization channel that gradually expands from the contact assembly to the arc-extinguishing chamber between the first and second sidewalls.

4. The circuit breaker according to claim 2, characterized in that: It also includes a moving arc-initiating plate, one end of which is disposed downstream of the gas travel path and close to the moving contact, and the other end is connected to the moving contact at the same potential.

5. The circuit breaker according to claim 4, characterized in that: The width of the end of the moving arc-initiating plate located downstream of the gas travel path is smaller than the distance between the first sidewall and the second sidewall, thereby creating an air gap between one end of the moving arc-initiating plate and the first sidewall and / or the second sidewall.

6. The circuit breaker according to claim 1, characterized in that: The stationary contact has a stationary arc-inducing portion extending into the arc-extinguishing chamber. A convex bulge is provided between the stationary contact and the stationary arc-inducing portion to serve as an intermediate transition node for the arc, guiding the arc at one end of the stationary contact to the stationary arc-inducing portion.

7. The circuit breaker according to claim 1, characterized in that: The air baffle is made of an insulating gas-generating material.

8. The circuit breaker according to claim 1, characterized in that: The air baffle plate is equipped with reinforcing ribs.

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