A circuit breaker anti-backflash shield

Abstract

The utility model discloses a circuit breaker anti -blowout protection cover, including the shell body and the pivot body in shell body, moving contact, static contact and anti -blowout board, the moving contact is driven rotation by operating mechanism, and the recess that accommodates pivot body has in the shell body, the anti -blowout board includes the installation portion and the air baffle, the installation portion is connected with moving contact, and the air baffle extends to both sides along the arc from the installation portion, and the recess outer periphery has the arc slot for the air baffle movement, when circuit breaker opens or closes, the air baffle all at least hides the partial opening between moving contact and shell body inner wall. Circuit breaker anti -blowout protection cover of the utility model not only can shield the opening of arc chamber entrance in the process of opening, but also can shield its opening in the process of closing, thereby avoiding the airflow impact of abnormal opening after a short time closing or opening instant, improves the service life of circuit breaker.

Description

Technical Field

[0001] This utility model relates to the field of circuit breaker design technology, and in particular to a circuit breaker anti-backflow protective cover. Background Technology

[0002] Molded case circuit breakers are current-limiting low-voltage circuit breakers used in industrial low-voltage power distribution, motor circuits, and other applications. They can connect and disconnect circuits under rated load and automatically disconnect circuits in case of faults. The electric arc generated when power equipment is switched on or off reaches extremely high temperatures, which can burn contacts, shorten equipment lifespan, and may even cause fires or explosions, affecting power quality.

[0003] To prevent the reverse airflow generated during the opening process from impacting the contact support at the entrance of the arc-extinguishing chamber, existing molded case circuit breakers typically have an anti-blowing protection plate installed at the opening on the closing side of the moving contact at the entrance of the arc-extinguishing chamber (between the stationary contact and the moving contact at the entrance of the arc-extinguishing chamber), such as the anti-backflow component in patent number CN218160201U.

[0004] However, when the circuit breaker is closed immediately after abnormal tripping, and at the moment of tripping, the instantaneous change in voltage will also generate airflow impact. At this time, the airflow mainly impacts the contact support from the opening on the side of the moving contact in the tripping direction, so there is a certain risk of damage to the contact support.

[0005] In addition, during the splitting process, metal particles can easily adhere to the shaft, which can cause the shaft to become stuck and inflexible. An increase in metal particles can lead to a short circuit risk during secondary splitting. Utility Model Content

[0006] To address the technical problems of existing circuit breakers that fail to consider the protection of the rotating shaft and moving contacts at the moment of disconnection between the moving and stationary contacts, leading to shaft jamming and affecting the secondary disconnection effect, this utility model provides a circuit breaker anti-backflow protective cover to solve the above problems.

[0007] The technical solution adopted by this utility model to solve its technical problem is: a circuit breaker anti-backflow protective cover, including an outer shell and a rotating shaft, a moving contact, a stationary contact and an anti-backflow plate located inside the outer shell. The moving contact is driven to rotate by an operating mechanism, and the outer shell has a groove to accommodate the rotating shaft. The anti-backflow plate includes a mounting part and an air baffle plate. The mounting part is connected to the moving contact, and the air baffle plate extends arcuately from the mounting part to both sides. The outer periphery of the groove has an arcuate groove for the movement of the air baffle plate. When the circuit breaker is open or closed, the air baffle plate at least covers part of the opening between the moving contact and the inner wall of the outer shell.

[0008] In an optional embodiment of this utility model, the operating mechanism is located outside the outer casing and is connected to the rotating shaft via a connecting rod.

[0009] In an optional embodiment of this invention, a metal sheet is installed on the inner surface of the baffle plate extending toward the stationary contact. During the closing process, the friction between the metal sheet and the rotating shaft effectively removes metal particles adsorbed on the rotating shaft during the breaking process, thereby improving the withstand voltage rating and service life of the circuit breaker after testing.

[0010] In an optional embodiment of this utility model, the mounting part is sleeved on the moving contact and riveted to the moving contact.

[0011] In an optional embodiment of this utility model, an arc-extinguishing chamber is provided inside the outer casing, the rotating shaft is located outside the arc-extinguishing chamber, the arc-extinguishing chamber has an inlet facing the rotating shaft and an outlet communicating with the outside of the outer casing, and the moving contact extends into the arc-extinguishing chamber through the inlet.

[0012] In an optional embodiment of this utility model, the normal direction of the inlet is perpendicular to the normal direction of the outlet.

[0013] In an optional embodiment of this invention, the arc-extinguishing chamber is located at the lower part of the outer shell.

[0014] In an optional embodiment of this utility model, the rotating shaft body is hollow inside, and a notch is provided on the outer peripheral surface of the rotating shaft body, with the notch facing the position of the moving contact when the circuit is opened.

[0015] In an optional embodiment of this utility model, the metal sheet is in contact with the surface of the rotating shaft.

[0016] The beneficial effects of this utility model are: (1) The anti-backflow protective cover of the circuit breaker described in this utility model can not only cover the opening of the arc-extinguishing chamber inlet during the opening process, but also block its opening during the closing process, thereby avoiding the airflow impact caused by the short-term closing after abnormal opening and the instantaneous opening, and improving the service life of the circuit breaker.

[0017] (2) The present invention has a metal sheet on the anti-backflow plate. During the closing process, the moving contact rotates, and the metal sheet comes into close contact with the rotating shaft and generates friction. The relative movement of the two effectively removes the metal particles adsorbed on the rotating shaft during the disconnection process, thereby improving the withstand voltage level and service life of the circuit breaker after the test.

[0018] (3) The present invention places the arc-extinguishing chamber at the lower part of the outer shell, which can increase the area of ​​the arc-extinguishing chamber and change the orientation of the arc-extinguishing chamber inlet, so that the inlet and outlet of the arc-extinguishing chamber are not on opposite sides, further reducing the impact of airflow and reducing the risk of external impurities entering the area where the rotating shaft is located. Attached Figure Description

[0019] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0020] Figure 1 This is a perspective view of the anti-backflow plate in this utility model; Figure 2 yes Figure 1 A cross-sectional schematic diagram of the anti-backflow plate shown; Figure 3 This is a front view of the outer shell of this utility model; Figure 4 This is a schematic diagram of the internal structure of the anti-backflow protective cover of the circuit breaker described in this utility model when the moving contact is in the closed state; Figure 5 yes Figure 4 Enlarged view of point a in the middle; Figure 6 This is a schematic diagram of the internal structure of the anti-backflow protective cover of the circuit breaker described in this utility model when the moving contact is in the open state.

[0021] In the figure, 1. Rotating shaft, 2. Anti-backflow plate, 2-1 Mounting part, 2-2. Air baffle, 2-3. Metal sheet, 3. Moving contact, 4. Stationary contact, 5. Arc extinguishing chamber, 6. Outer shell, 6-1. Arc groove, 7. Groove, 9. Notch, 10. Inlet, 11. Outlet, 12. First side wall, 13. Second side wall. Detailed Implementation

[0022] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0023] Example 1 like Figures 1-4 As shown, a circuit breaker anti-backflow protective cover includes a housing 6 and a rotating shaft 1, a moving contact 3, a stationary contact 4, and an anti-backflow plate 2 located within the housing 6. The rotating shaft 1 is driven to rotate by an operating mechanism (the operating mechanism is the same as in the prior art and is not shown in the figure). The rotating shaft 1 is hollow inside and has a contact support (not shown in the figure). The contact support is used to provide pressure between the moving contact 3 and the stationary contact 4. The rotating shaft 1 drives the moving contact 3 to rotate, and the rotation centers of the two do not coincide. The housing 6 has a groove 7 to accommodate the rotating shaft 1, and the groove 7 is used to limit the rotation of the rotating shaft 1. Normally, a notch 9 is opened on the outer peripheral surface of the rotating shaft 1, and the contact support is inserted into the rotating shaft 1 through the notch 9. The notch 9 is set towards the position of the moving contact 3 when the circuit is open.

[0024] The anti-backflow plate 2 includes a mounting part 2-1 and an air baffle plate 2-2. The mounting part 2-1 is connected to the moving contact 3. The air baffle plate 2-2 extends arcuately from the mounting part 2-1 to both sides. The outer periphery of the groove 7 has an arcuate groove 6-1 for the movement of the air baffle plate 2-2. When the circuit breaker is open or closed, the air baffle plate 2-2 at least covers part of the opening between the moving contact 3 and the inner wall of the outer casing 6. The mounting part 2-1 is preferably fitted onto the moving contact 3 and riveted to it. The riveting installation method ensures that the component is not easy to fall off, enhancing insulation and safety.

[0025] like Figure 1 and Figure 2 As shown, an arc-extinguishing chamber 5 is typically provided inside the outer casing 6. The rotating shaft 1 is located outside the arc-extinguishing chamber 5. The arc-extinguishing chamber 5 has an inlet 10 connected to the rotating shaft 1. The moving contact 3 extends into the arc-extinguishing chamber 5 through the inlet 10. The inlet 10 is formed between the first side wall 12 and the second side wall 13 inside the outer casing 6. The stationary contact 4 is installed inside the first side wall 12. The moving contact 3 moves between the first side wall 12 and the second side wall 13. When the moving contact 3 moves to the first side wall 12, the moving contact 3 contacts the stationary contact 4, completing the closing (e.g., Figure 4 As shown), when the moving contact 3 moves to the second side wall 13, the moving contact 3 and the stationary contact 4 are separated, completing the tripping (as shown). Figure 5 (As shown). In the closed state, there is an opening between the moving contact 3 and the second side wall 13 in the inlet 10. In the open state, there is an opening between the moving contact 3 and the first side wall 12 in the inlet 10. Since the baffle plate 2-2 extends from the mounting part 2-1 to both sides, the baffle plate 2-2 can block the opening whether the circuit is open or closed. The size of the blocking range can be determined by adjusting the size of the baffle plate 2-2. Preferably, the baffle plate 2-2 can block the entire opening.

[0026] In the prior art, the anti-backflow component only blocks the opening between the moving contact 3 and the first side wall 12 during the opening process. On the one hand, it does not consider the situation of sudden closing after abnormal opening and the instant of opening, in which the reverse airflow will impact the shaft body 1 from the opening between the moving contact 3 and the second side wall 13. On the other hand, the prior art circuit breakers all have all components (including the operating mechanism) placed in the housing 6, with the operating mechanism mainly placed on one side of the second side wall 13. This area does not have space for the anti-backflow protection plate to move. Therefore, the prior art anti-backflow component only has an anti-backflow protection plate on one side of the moving contact 3.

[0027] This utility model places the operating mechanism on the outside of the outer casing 6, specifically... Figure 3The area circled in the middle is connected to the rotating shaft 1 via a connecting rod (specifically, it is connected to the contact support via a connecting rod), enabling the operating mechanism to indirectly control the moving contact 3. This also leaves the area inside the outer casing 6 near the second side wall 13 empty, allowing for the installation of an arc-shaped groove 6-1 for the movement of the baffle plate 2-2.

[0028] Example 2 Based on Embodiment 1, a metal sheet 2-3 (such as...) is installed on the inner surface of the baffle plate 2-2 extending toward the stationary contact 4. Figure 2 (As shown). When the moving contact 3 rotates, the residual metal particles on the rotating shaft 1 are rubbed away by the mutual movement between the baffle plate 2-2 and the rotating shaft 1. The particles are removed by friction, achieving self-cleaning. The metal plate 2-3 preferably contacts the surface of the rotating shaft 1 to increase friction. The baffle plate 2-2 is made of elastic material. Due to the certain eccentricity between the moving contact 3 and the rotating shaft 1, the metal plate 2-3 and the baffle plate 2-2 can deform along the surface of the rotating shaft 1 during the rotation of the moving contact 3, ensuring continuous contact between the metal plate 2-3 and the rotating shaft 1.

[0029] Example 3 The outer casing 6 is typically also provided with an outlet 11 that communicates with the arc-extinguishing chamber 5. Based on the above embodiment, this embodiment makes the normal direction of the inlet 10 perpendicular to the normal direction of the outlet 11. In this way, when there is reverse airflow, the impact velocity of metal particles and high-temperature airflow when they reach the inlet 10 can be greatly reduced, thereby ensuring that the baffle plate 2-2 can block metal particles and high-temperature airflow.

[0030] In traditional molded case circuit breakers, the rotating shaft 1 and the arc-extinguishing chamber 5 are arranged in a front-to-back direction, so the outlet and the inlet are opposite each other. In this embodiment, with the position of the outlet 11 on the outer casing 6 unchanged, the arc-extinguishing chamber 5 is set in the lower part of the outer casing 6, that is, below the rotating shaft 1, thereby changing the direction of the inlet 10.

[0031] In the description of this utility model, it should be understood that the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0032] In this specification, the illustrative expressions of the terms do not necessarily refer to the same embodiments. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments.

[0033] Based on the above-described preferred embodiments of this utility model, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the technical concept of this utility model. The technical scope of this utility model is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A circuit breaker anti-backflow protective cover, characterized in that: It includes an outer shell (6) and a rotating shaft (1), a moving contact (3), a stationary contact (4) and an anti-backflow plate (2) located inside the outer shell (6). The moving contact (3) is driven to rotate by an operating mechanism. The outer shell (6) has a groove (7) for accommodating the rotating shaft (1). The anti-backflow plate (2) includes a mounting part (2-1) and a baffle plate (2-2). The mounting part (2-1) is connected to the moving contact (3). The baffle plate (2-2) extends arc-shapedly from the mounting part (2-1) to both sides. The outer periphery of the groove (7) has an arc-shaped groove (6-1) for the movement of the baffle plate (2-2). When the circuit breaker is open or closed, the baffle plate (2-2) at least covers part of the opening between the moving contact (3) and the inner wall of the outer casing (6).

2. The circuit breaker anti-backflow protective cover according to claim 1, characterized in that: The operating mechanism is located outside the outer casing (6) and is connected to the rotating shaft (1) via a connecting rod.

3. The circuit breaker anti-backflow protective cover according to claim 1, characterized in that: A metal sheet (2-3) is installed on the inner surface of the baffle plate (2-2) extending toward the stationary contact (4).

4. The circuit breaker anti-backflow protective cover according to claim 1, characterized in that: The mounting part (2-1) is fitted onto the moving contact (3) and is riveted to the moving contact (3).

5. The circuit breaker anti-backflow protective cover according to claim 1, characterized in that: The outer casing (6) is provided with an arc-extinguishing chamber (5), the rotating shaft (1) is located outside the arc-extinguishing chamber (5), the arc-extinguishing chamber (5) has an inlet (10) facing the rotating shaft (1) and an outlet (11) communicating with the outside of the outer casing (6), and the moving contact (3) extends into the arc-extinguishing chamber (5) through the inlet (10).

6. The circuit breaker anti-backflow protective cover according to claim 5, characterized in that: The normal direction of the inlet (10) is perpendicular to the normal direction of the outlet (11).

7. The circuit breaker anti-backflow protective cover according to claim 5, characterized in that: The arc-extinguishing chamber (5) is located at the lower part of the outer shell (6).

8. The circuit breaker anti-backflow protective cover according to claim 3, characterized in that: The rotating shaft (1) is hollow inside, and a notch (9) is provided on the outer circumferential surface of the rotating shaft (1). The notch (9) is set towards the position of the moving contact (3) when the circuit is opened.

9. The circuit breaker anti-backflow protective cover according to claim 3, characterized in that: The metal sheet (2-3) is in contact with the surface of the rotating shaft (1).

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