Arc extinguishing system of large-current miniature circuit breaker

Abstract

The invention discloses an arc extinguishing system of a large-current miniature circuit breaker, and the system comprises a housing which is internally provided with an arc extinguishing chamber, a static contact rod, and a moving contact. An arc blowing piece is installed at the contact position of the static contact rod and the moving contact, and arc generated at the breaking moment of the moving contact and the static contact rod is accelerated to move into the arc extinguish chamber through the arc blowing piece. The belly space of the arc blowing piece is larger than the opening space of the arc blowing piece, and the opening space of the arc blowing piece is located on the two sides of the contact position of the static contact rod and the moving contact. Therefore, the distance between the inner side face of the arc blowing piece and the moving contact and the distance between the inner side face of the arc blowing piece and the static contact are reduced, the inner side face of the arc blowing piece is closer to an electric arc, electric repulsive force of the moving contact and the static contact and magnetic blowing force to the electric arc are enhanced, and the electric arc is rapidly transferred to an arc extinguish chamber from the contacts. The arc blowing piece is arranged to be of a convex structure, and an arc magnetic field at the opening part of the arc blowing piece and an electromagnetic field at the bottom of the arc blowing piece form a gradient magnetic field from weak to strong, so that the transfer speed of the arc to the arc extinguish chamber can be greatly accelerated.

Description

Technical Field

[0001] This invention relates to the field of switchgear technology, specifically to an arc extinguishing system for a high-current miniature circuit breaker. Background Technology

[0002] Currently, in the industry, when performing short-circuit breaking tests on high-current miniature circuit breakers, the limited casing volume severely compresses the arc-extinguishing chamber space, resulting in severe burning of the moving and stationary contacts after the breaking test. Furthermore, the arc energy is relatively large during the test, and the flying arc is very likely to be ejected from the casing, burning out the fuse and causing the breaking test to fail. Summary of the Invention

[0003] The purpose of this invention is to provide an arc extinguishing system for a high-current miniature circuit breaker to solve the problems mentioned in the background art.

[0004] To achieve the above objectives, the present invention provides the following technical solution: an arc-extinguishing system for a high-current miniature circuit breaker, comprising a housing, wherein an arc-extinguishing chamber, a stationary contact rod, and a moving contact are provided within the housing; an arc-blowing component is installed at the contact point between the stationary contact rod and the moving contact, and the arc-blowing component accelerates the movement of the arc generated by the moving contact and the stationary contact rod at the moment of disconnection into the arc-extinguishing chamber; the abdominal space of the arc-blowing component is larger than the oral space of the arc-blowing component, so as to form a gradient space within the arc-blowing component, and the oral portion of the arc-blowing component is located on both sides of the contact point between the stationary contact rod and the moving contact.

[0005] As a preferred embodiment of the present invention, the side of the arc blowing component facing the moving contact is further provided with a gas generating component.

[0006] As a preferred technical solution of the present invention: the gas generating component is made of nylon, and an arc-inducing groove is provided on the inner wall surface of the gas generating component.

[0007] As a preferred technical solution of the present invention: an arc-inducing component is further provided between the arc-extinguishing chamber and the stationary contact rod, and the arc-extinguishing space of the arc-extinguishing chamber is expanded above the arc-extinguishing chamber by the arc-inducing component.

[0008] As a preferred technical solution of the present invention: the arc-initiating component includes an arc-extinguishing plate located above the arc-extinguishing chamber and a connecting portion located on the side of the arc-extinguishing chamber, wherein the end of the connecting portion away from the arc-extinguishing plate is fixedly installed on the side of the stationary contact rod facing the moving contact.

[0009] As a preferred technical solution of the present invention: the connecting part includes an arc segment, the end of the arc segment away from the stationary contact rod is connected to the arc extinguishing plate through a connecting segment, and the space of the connecting segment gradually decreases from one end of the stationary contact rod to one end of the arc extinguishing plate.

[0010] As a preferred technical solution of the present invention: the housing is further provided with a pressure relief component, and the pressure relief component is located on the side of the arc extinguishing chamber away from the arc blowing component.

[0011] As a preferred technical solution of the present invention: the outer wall surface of the pressure relief component is further provided with a protrusion, and the protrusion contacts the inner wall surface of the housing, so that a cavity is formed between the outer side surface of the pressure relief component and the inner side surface of the housing.

[0012] As a preferred technical solution of the present invention: the arc blowing component includes a first magnetic sheet and a second magnetic sheet, and the upper ends of the first magnetic sheet and the second magnetic sheet are provided with a bent portion for forming an opening.

[0013] As a preferred technical solution of the present invention: the side surface area of ​​the first magnetic sheet is larger than the side surface area of ​​the bent portion, so as to expand the pressure relief space of the arc blowing component.

[0014] The beneficial effects of the present invention using the above technical solution are as follows: Since the space at the opening of the arc blowing component is smaller than the space in the belly, i.e., the arc blowing component is convex when viewed from the side, the distance between the inner side of the arc blowing component and the moving and stationary contacts can be reduced. When the moving and stationary contacts are opened during the short-circuit breaking test, the inner side of the arc blowing component is closer to the arc, thereby enhancing the electrodynamic repulsion force of the moving and stationary contacts and the magnetic blowing force on the arc, realizing the rapid transfer of the arc from the contacts to the arc extinguishing chamber. At the same time, the arc blowing component is set as a convex structure. During the circuit breaker breaking test, the arc magnetic field at the opening of the arc blowing component and the electromagnetic field at the bottom of the arc blowing component form a gradient magnetic field from weak to strong, which can greatly accelerate the transfer speed of the arc to the arc extinguishing chamber. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the internal structure of the present invention;

[0016] Figure 2 This is an exploded structural diagram of the pressure relief component, arc extinguishing chamber, arc blowing component, gas generating component, arc ignition component, and stationary contact rod.

[0017] Figure 3 This is a schematic diagram of the main structure of the arc-initiating component of the present invention;

[0018] Figure 4 This is a side view of the arc blowing component of the present invention.

[0019] Figure 5 This is a schematic diagram of the main structure of the arc blowing component of the present invention;

[0020] Figure 6 This is an exploded structural diagram of the gas-generating component of the present invention;

[0021] Figure 7 This is a schematic diagram of the main structure of the pressure relief component of the present invention;

[0022] Figure 8 This is a schematic diagram of the structure of the present invention after being cut open on one side of the pressure relief component;

[0023] Figure 9 This is a schematic diagram showing the positional relationship between the arc-initiating component, the arc-extinguishing chamber, and the stationary contact rod.

[0024] Figure 10 This is a schematic diagram of the internal structure of the housing of the present invention.

[0025] In the diagram: 1. Shell; 2. Arc-extinguishing chamber; 3. Arc-blowing component; 30. First magnetic conductive sheet; 31. Second magnetic conductive sheet; 32. Bending section; 4. Pressure relief component; 5. Stationary contact rod; 6. Arc-initiating component; 60. Arc-extinguishing sheet; 61. Fixed end; 62. Connecting section; 63. Connecting part; 64. Arc segment; 7. Moving contact; 8. Gas-generating component; 9. Protrusion; 10. Arc-initiating groove; 11. Chamber; 12. Slot. Detailed Implementation

[0026] The embodiments of the present invention 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 intended to explain the present invention, and should not be construed as limiting the present invention. In the description of the present invention, it should be understood that the terms "upper," "lower," "front," "upper surface," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and 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 limiting the present invention.

[0027] Please see Figures 1-10 This invention provides an embodiment of an arc-extinguishing system for a high-current miniature circuit breaker, comprising a housing 1, an arc-extinguishing chamber 2, a stationary contact rod 5, and a moving contact 7 within the housing 1; an arc-blowing element 3 is installed at the contact point between the stationary contact rod 5 and the moving contact 7, and the arc-blowing element 3 accelerates the movement of the arc generated by the moving contact 7 and the stationary contact rod 5 at the moment of disconnection into the arc-extinguishing chamber 2; the abdominal space of the arc-blowing element 3 is larger than the opening space of the arc-blowing element 3, so that a gradient space is formed within the arc-blowing element 3, and the opening of the arc-blowing element 3 is located on both sides of the contact point between the stationary contact rod 5 and the moving contact 7. The gradient space refers to the distance between the inner side of the opening of the arc-blowing element 3 and the outer side of the moving contact 7 being smaller than the distance between the inner side of the abdominal space of the arc-blowing element 3 and the moving contact 7.

[0028] In summary, since the space at the opening of the arc-blowing component 3 is smaller than the space in its belly, meaning the arc-blowing component 3 is convex when viewed from the side, the distance between the inner surface of the arc-blowing component 3 and the moving contact 7 and the stationary contact can be reduced. When the moving and stationary contacts open during the short-circuit breaking test, the inner surface of the arc-blowing component 3 is closer to the arc, thereby enhancing the electrodynamic repulsion of the moving and stationary contacts and the magnetic blowing force on the arc, enabling the arc to quickly transfer from the contacts to the arc-extinguishing chamber. At the same time, the arc-blowing component 3 is designed with a convex structure. During the circuit breaker breaking test, the arc magnetic field at the opening of the arc-blowing component 3 and the electromagnetic field at the bottom of the arc-blowing component 3 form a gradient magnetic field from weak to strong, which can greatly accelerate the transfer speed of the arc to the arc-extinguishing chamber.

[0029] Specifically, such as Figure 4 and Figure 5 As shown, the arc blowing component 3 includes a first magnetic sheet 30 and a second magnetic sheet 31. The upper ends of the first magnetic sheet 30 and the second magnetic sheet 31 are provided with bent portions 32 for forming the opening. By bending the two magnetic sheets towards the moving contact 7 using the bent portions 32, the distance between the facing surfaces of the openings of the arc blowing component 3 is reduced, thereby making the space in the belly of the arc blowing component 3 larger than the space in its opening. This allows the bent portions 32 on the two magnetic sheets to be closer to the moving contact 7. When an electric arc is generated, the opening initiates the arc while simultaneously releasing pressure. When the electric arc enters the belly of the arc blowing component 3, the increased space in the belly allows for further pressure release, thus achieving gradient pressure release.

[0030] Furthermore, when the electric arc flows from the bending portion 32 to the first magnetic sheet 30, since the side area of ​​the first magnetic sheet 30 is larger than the side area of ​​the bending portion 32, the pressure relief space of the arc blowing component 3 is expanded. Based on this, firstly, by expanding the area of ​​the magnetic sheet, the heat generation of the arc blowing component 3 is reduced, and the heat loss of the electric arc source can also be improved by expanding the area; secondly, by expanding the abdominal space, the pressure of the electric arc is relieved.

[0031] like Figure 1 and Figure 2 As shown, since the side of the arc blowing component 3 facing the moving contact 7 is also provided with a gas generating component 8, the gas generated by the gas generating component 8 is blown toward the arc to accelerate the extinction of the arc; specifically, the gas generating component 8 is wrapped around the arc blowing component 3 from the inner side to the outer side, so that the gas generating component 8 also has a structure similar to the magnetic sheet, and can also realize two gradient air blowing, thus forming a gradient air blowing of the arc space from small to large, realizing the rapid transfer of the arc to the arc extinguishing chamber 2.

[0032] Furthermore, such as Figure 6As shown, the gas generating component 8 is made of nylon, such as gas-generating nylon or other gas-generating materials. Under the high temperature of the electric arc, it will rapidly decompose and generate a large amount of high-pressure gas. This gas can cool the electric arc, reduce the arc temperature and energy, and accelerate the arc extinguishing. On the other hand, it can blow away the arc, lengthen and disperse the arc, destroy the conditions for the arc to continue burning, and prevent the arc from reigniting. At the same time, the inner wall of the gas generating component 8 is also provided with an arc-initiating groove 10. Therefore, the arc-initiating groove 10 can be used to guide the arc to move in a directional direction into the arc-extinguishing chamber 2. The arc-shaped arc-initiating groove 10 can also accelerate the arc to flow along the arc-initiating groove 10 into the arc-extinguishing chamber 2.

[0033] To further address the problems of existing circuit breakers where the limited casing volume severely restricts the arc-extinguishing chamber space, leading to severe burning of the moving and stationary contacts after breaking tests, and the high arc energy during testing causing the arc to easily eject from the casing and burn out the fuse, an arc-initiating element 6 is provided between the arc-extinguishing chamber 2 and the stationary contact rod 5. This arc-initiating element 6 expands the arc-extinguishing space of the arc-extinguishing chamber 2 above it. Therefore, by positioning the arc-initiating element 6 above the arc-extinguishing chamber 2, it also participates in the arc-extinguishing operation of the arc-extinguishing chamber 2, thereby expanding its space.

[0034] Specifically, such as Figure 1 , Figure 3 and Figure 10 As shown, the arc-initiating component 6 includes an arc-extinguishing plate 60 located above the arc-extinguishing chamber 2 and a connecting portion 63 located on the side of the arc-extinguishing chamber 2. The end of the connecting portion 63 away from the arc-extinguishing plate 60 is fixedly installed on the side of the stationary contact rod 5 facing the moving contact 7 to achieve rapid arc transfer. In order to facilitate the fixing of the arc-initiating component 6, one end of the arc-initiating component 6 is fixed to the stationary contact rod 5 with a rivet, and the other end is inserted into the slot 12 provided in the housing 1 through the fixed end 61.

[0035] like Figure 3 and Figure 9 As shown, the connecting part 63 includes an arc segment 64. The end of the arc segment 64 away from the stationary contact rod 5 is connected to the arc extinguishing plate 60 through a connecting section 62. The space of the connecting section 62 gradually decreases from one end of the stationary contact rod 5 to one end of the arc extinguishing plate 60.

[0036] Therefore, the electric arc can move along the arc segment 64 towards the bottom of the arc-extinguishing chamber 2, then move upwards along the connecting segment 62, and finally enter the arc-extinguishing plate 60. During this process, the distance the arc travels is extended, and the arc remains close to the arc-extinguishing chamber 2 until it enters the arc-extinguishing plate 60, thus enhancing the arc-extinguishing effect of the arc-extinguishing chamber 2. Furthermore, the width of the arc segment 64 is greater than the width of the connecting segment 62, allowing the arc segment 64 to receive the instantaneous impact of the arc. This impact is then gradually released through the connecting segment 62, finally reaching the arc-extinguishing plate 60, thus gradually extinguishing the arc's energy. Based on this, while improving the arc-extinguishing effect, the service life of the arc-initiating element 6 can also be extended, thereby extending the service life of the equipment.

[0037] like Figure 6 , Figure 7 and Figure 8 As shown, the housing 1 also includes a pressure relief component 4, which is located on the side of the arc-extinguishing chamber 2 away from the arc-blowing component 3. Therefore, the pressure relief component 4 can be used to extinguish arcs at their end or those that have not been completely extinguished. Specifically, the outer wall of the pressure relief component 4 is provided with a protrusion 9, which contacts the inner wall of the housing 1, thereby forming a chamber 11 between the outer surface of the pressure relief component 4 and the inner surface of the housing 1.

[0038] In summary, after the arc-extinguishing chamber 2 cuts and extinguishes most of the electric arc, the remaining electric arc is transferred to the chamber 11 through the tail of the arc-extinguishing chamber 2. The protrusion 9 on the chamber 11 is used to divide the remaining electric arc to dissipate the energy of the electric arc, thereby avoiding the phenomenon of flying arcs spraying out of the shell 1 and causing the fuse to burn out.

[0039] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and these variations still fall within the protection scope of the present invention.

Claims

1. An arc quenching system for a high current miniature circuit breaker, characterized by: The application relates to a circuit breaker, which comprises a shell (1), an arc extinguishing chamber (2), a static contact rod (5) and a movable contact (7) arranged in the shell (1); an arc blowing piece (3) is arranged at the contact position of the static contact rod (5) and the movable contact (7), and the arc generated at the moment of breaking is moved into the arc extinguishing chamber (2) through the arc blowing piece (3). The space of the abdomen of the arc blowing piece (3) is larger than the space of the mouth of the arc blowing piece (3), so that a gradient space is formed in the arc blowing piece (3), and the mouth of the arc blowing piece (3) is arranged on both sides of the contact position of the static contact rod (5) and the movable contact (7).

2. The arc quenching system of a small size high current circuit breaker according to claim 1, characterized in that: One side of the arc blowing piece (3) facing the movable contact (7) is further provided with a gas generating piece (8).

3. A small-sized high current circuit breaker's arc extinguishing system according to claim 2, characterized in that: The gas generating piece (8) is made of nylon, and an arc guiding groove (10) is further arranged on the inner wall surface of the gas generating piece (8).

4. The arc quenching system of a small size high current circuit breaker according to claim 1, characterized in that: An arc guiding piece (6) is further arranged between the arc extinguishing chamber (2) and the static contact rod (5), and the arc extinguishing space of the arc extinguishing chamber (2) is expanded above the arc extinguishing chamber (2) through the arc guiding piece (6).

5. A small-sized high current circuit breaker's arc extinguishing system according to claim 4, characterized in that: The arc guiding piece (6) comprises an arc extinguishing sheet (60) arranged above the arc extinguishing chamber (2) and a connecting part (63) arranged on the side of the arc extinguishing chamber (2), and one end of the connecting part (63) away from the arc extinguishing sheet (60) is fixedly arranged on the side of the static contact rod (5) facing the movable contact (7).

6. A small-sized high current circuit breaker's arc extinguishing system according to claim 5, characterized in that: The connecting part (63) comprises a circular arc segment (64), one end of the circular arc segment (64) away from the static contact rod (5) is connected with the arc extinguishing sheet (60) through a connecting segment (62), and the space of the connecting segment (62) gradually decreases from one end of the static contact rod (5) to one end of the arc extinguishing sheet (60).

7. The arc quenching system of a high current miniature circuit breaker of claim 1, wherein: A pressure relief piece (4) is further arranged in the shell (1), and the pressure relief piece (4) is arranged on the side of the arc extinguishing chamber (2) away from the arc blowing piece (3).

8. The arc quenching system of a high current miniature circuit breaker according to claim 7, characterized in that: The outer wall surface of the pressure relief piece (4) is further provided with a protruding part (9), and the outer wall surface of the pressure relief piece (4) is in contact with the inner wall surface of the shell (1) through the protruding part (9), so that a cavity (11) is formed between the outer side surface of the pressure relief piece (4) and the inner side surface of the shell (1).

9. An arc quenching system for a small-sized high current circuit breaker according to any one of claims 1 to 8, characterized in that: The arc blowing piece (3) comprises a first magnetic conducting sheet (30) and a second magnetic conducting sheet (31), and the upper ends of the first magnetic conducting sheet (30) and the second magnetic conducting sheet (31) are provided with bending parts (32) for forming the mouth.

10. The arc quenching system of a high current miniature circuit breaker of claim 9, wherein: The side surface area of the first magnetic conducting sheet (30) is larger than the side surface area of the bending part (32), so that the pressure relief space of the arc blowing piece (3) is expanded.

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