Miniature circuit breaker

Abstract

Provided is a miniature circuit breaker. The problem that an existing miniature circuit breaker is weak in breaking capacity is solved. The device comprises a shell, the movable contact piece is arranged in the shell; the arc extinguish chamber comprises an arc extinguish frame and arc extinguish grid sheets, the arc extinguish grid sheets are arranged on the arc extinguish frame, the number of the arc extinguish grid sheets is multiple, and arc extinguish notches are formed in the arc extinguish grid sheets; the movable contact piece is provided with a first position attached to the static contact piece and a second position separated from the static contact piece; the static contact piece comprises an arc striking part, the arc striking part is arranged in front of the arc extinguishing grid piece, and the projection of the end part of the static contact piece on the plane falls into the arc extinguishing notch of the arc extinguishing grid piece. The beneficial effects of the utility model are that the arc striking part is arranged in front of the arc extinguishing grid sheet, and the projection of the end part of the static contact sheet on the plane falls in the arc extinguishing gap of the arc extinguishing grid sheet, so that reliable and rapid arc striking can be realized, the arc can enter the arc extinguishing chamber for arc extinguishing, and even if particles are generated during arc extinguishing, the particles cannot fall on the arc extinguishing grid sheet to cause short circuit.

Description

Technical Field

[0001] The utility model relates to the field of low-voltage electrical appliances, in particular to a small circuit breaker. Background Art

[0002] Miniature circuit breakers (English name: Miniature Circuit Breaker), also known as microcircuit breakers, are suitable for overload and short-circuit protection of low-voltage lines. They can also be used for infrequent operation conversion of lines under normal circumstances. Miniature circuit breakers are mainly used in various places such as industry, commerce, high-rise and residential buildings. Miniature circuit breakers usually include a housing, an operating mechanism, a tripping system, a contact system, an arc extinguishing system, etc. The operating mechanism drives the moving contact in the contact system through the operating handle to connect and disconnect the miniature circuit breaker to control the electrical circuit; by sensing the thermal effect and magnetic effect of the current, protection is implemented when the electrical circuit is overloaded, short-circuited, and other faults occur. During the disconnection process between the moving contact and the static contact, an arc will be generated. The arc is usually led into the arc extinguishing chamber of the arc extinguishing system through the arc-starting plate. When the arc is introduced into the arc extinguishing chamber, it is divided into many sections by the metal grid in the arc extinguishing chamber. Each arc section generates a near-pole voltage near the metal grid, which rapidly increases the voltage drop of the entire arc and extinguishes the arc. However, the existing static contact usually extends to the top of the arc extinguishing chamber. When disconnecting a large current, the static contact, arc extinguishing plate, etc. will melt to form particles. The existence of these particles between the static contact and the arc extinguishing grid above the arc extinguishing chamber is prone to short circuit, affecting the product disconnection and posing a major safety hazard. Therefore, the existing small circuit breaker can usually only disconnect a current of 10kA, and the disconnection capacity is relatively weak. Utility Model Content

[0003] In order to solve the problem of weak breaking capacity of existing small circuit breakers in the background technology, the utility model provides a small circuit breaker.

[0004] The technical solution of the utility model is: a small circuit breaker, including a housing, and also including:

[0005] A moving contact piece is arranged in the housing;

[0006] An arc extinguishing chamber is arranged in the housing, the arc extinguishing chamber comprises an arc extinguishing frame and an arc extinguishing grid, the arc extinguishing grid is arranged on the arc extinguishing frame, there are multiple arc extinguishing grids, and an arc extinguishing notch is arranged on the arc extinguishing grid;

[0007] The static contact piece is arranged in the shell, and the dynamic contact piece has a first position in contact with the static contact piece and a second position separated from the static contact piece; the static contact piece includes an arc-striking portion, and the arc-striking portion is arranged in front of the arc-extinguishing grid piece, and the projection of the end of the static contact piece on the plane falls in the arc-extinguishing notch of the arc-extinguishing grid piece.

[0008] As a further improvement of the utility model, the arc extinguishing grid comprises arc guide feet, the arc guide feet are opened to form the arc extinguishing gap, and the end of the arc striking portion is provided with a chamfer or a slope.

[0009] As a further improvement of the utility model, a connecting portion is provided on the stationary contact piece, the connecting portion is connected to the arc-starting portion through an arc portion, and the connecting portion, the arc portion and the connecting portion are V-shaped.

[0010] As a further improvement of the present invention, the angle a formed by the connecting portion and the arc striking portion is 10° to 15°, and the angle b formed by the mounting portion on the stationary contact piece and the connecting portion is 145° to 155°.

[0011] As a further improvement of the present invention, a magnetic conductive sheet is provided in the space formed by the connecting portion and the arc-starting portion.

[0012] As a further improvement of the utility model, it also includes a tripper, which is arranged in the housing, and a first exhaust channel is formed between the tripper and the arc extinguishing chamber.

[0013] As a further improvement of the utility model, the releaser is provided with an exhaust notch, and the exhaust notch is connected to the first exhaust channel.

[0014] As a further improvement of the utility model, it also includes a first arc-striking piece, a second arc-striking piece is provided on the outer side of the first arc-striking piece, the second arc-striking piece and the first arc-striking piece are arranged in contact with each other, and an arc-striking area is provided between the first arc-striking piece and the static contact piece.

[0015] As a further improvement of the utility model, a second exhaust channel is provided between the second arc-striking piece and the inner wall of the shell, and the first arc-striking piece protrudes toward the arc-striking area to form a convex block portion.

[0016] As a further improvement of the present utility model, the shell includes a first shell and a second shell, the first shell is provided with a first mounting column, the second shell is provided with a second mounting column, the first mounting column is provided with a first mounting hole, the second mounting column is provided with a second mounting hole, the first mounting column is inserted into the second mounting hole, the first shell and the second shell are riveted together by rivets, and the first mounting column and the second mounting column are arranged at the static contact piece and limit the static contact piece.

[0017] The beneficial effect of the utility model is that the arc striking part is arranged in front of the arc extinguishing grid and the projection of the end of the static contact piece on the plane falls within the arc extinguishing gap of the arc extinguishing grid, so that the arc can be struck reliably and quickly, and the arc is convenient to enter the arc extinguishing chamber for arc extinguishing. Even if particles are generated during arc extinguishing, they will not fall on the arc extinguishing grid to cause a short circuit. The utility model also has the advantages of simple structure, convenient assembly, reliable operation, long service life, strong breaking capacity, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Attached Figure 1 It is a structural schematic diagram of an embodiment of the utility model.

[0019] Attached Figure 2 The figure is a schematic diagram of the explosion structure of an embodiment of the utility model.

[0020] Attached Figure 3 The figure is a schematic diagram of the explosion structure of an embodiment of the utility model.

[0021] Attached Figure 4 It is a schematic diagram of the structure inside the shell of an embodiment of the utility model.

[0022] Attached Figure 5 It is a structural schematic diagram of the arc extinguishing chamber of an embodiment of the utility model.

[0023] Attached Figure 6 It is a schematic structural diagram of the first shell of an embodiment of the utility model.

[0024] In the figure, 1, shell; 11, first shell; 111, first mounting column; 112, first mounting hole; 12, second shell; 121, second mounting column; 122, second mounting hole; 2, moving contact piece; 3, arc extinguishing chamber; 31, arc extinguishing frame; 32, arc extinguishing grid; 321, arc extinguishing notch; 322, arc guide foot; 4, static contact piece; 41, arc striking part; 411, inclined surface; 42, connecting part; 43, arc part; 44, mounting part; 5, magnetic conductive piece; 6, release; 61, exhaust notch; 71, first exhaust channel; 72, second exhaust channel; 81, first arc striking piece; 811, protrusion part; 82, second arc striking piece; 83, arc striking area. DETAILED DESCRIPTION

[0025] The following is a further description of the embodiments of the present invention in conjunction with the accompanying drawings:

[0026] Depend on Figure 1 Combination Figure 2-6 As shown, a miniature circuit breaker comprises a housing 1,

[0027] The moving contact piece 2 is arranged in the housing 1;

[0028] The arc extinguishing chamber 3 is arranged in the housing 1. The arc extinguishing chamber 3 comprises an arc extinguishing frame 31 and an arc extinguishing grid 32. The arc extinguishing grid 32 is arranged on the arc extinguishing frame 31. The arc extinguishing grid 32 has multiple pieces. The arc extinguishing grid 32 is provided with an arc extinguishing notch 321.

[0029] The static contact piece 4 is arranged in the housing 1, and the dynamic contact piece 2 has a first position in contact with the static contact piece and a second position separated from the static contact piece 4; the static contact piece 4 includes an arc-starting portion 41, and the arc-starting portion 41 is arranged in front of the arc-extinguishing grid piece 32, and the projection of the end of the static contact piece 4 on the plane falls within the arc-extinguishing gap 321 of the arc-extinguishing grid piece 32. The beneficial effect of the utility model is that the arc-starting portion is arranged in front of the arc-extinguishing grid piece and the projection of the end of the static contact piece on the plane falls within the arc-extinguishing gap of the arc-extinguishing grid piece, which can reliably and quickly start the arc, facilitate the arc to enter the arc-extinguishing chamber for arc-extinguishing, and even if particles are generated during arc-extinguishing, they will not fall on the arc-extinguishing grid piece to cause a short circuit. The utility model also has the advantages of simple structure, convenient assembly, reliable operation, long service life, and strong breaking capacity. The utility model can achieve the breaking of 20kA current.

[0030] The arc extinguishing grid 32 includes arc guide feet 322, which are opened to form the arc extinguishing gap 321, and the end of the arc striking portion 41 is provided with a chamfer or a bevel 411. Usually, two arc guide feet are provided on an arc extinguishing grid, and the two arc guide feet are opened to form an arc extinguishing gap. The arc striking portion is arranged at the arc extinguishing gap, and the end is provided with a chamfer or a bevel, so that even if the end of the arc extinguishing grid or the static contact piece melts, the particles will not cause the arc to form a path, causing the product to short-circuit and affecting the breaking performance of the product.

[0031] The stationary contact piece 4 is provided with a connecting portion 42, and the connecting portion 42 is connected to the arc striking portion 41 through an arc portion 43, and the connecting portion 42, the arc portion 43 and the connecting portion 42 are in a V shape. Specifically, the angle a formed by the connecting portion 42 and the arc striking portion 41 is 10° to 15°, and the angle b formed by the mounting portion 44 on the stationary contact piece 4 and the connecting portion 42 is 145° to 155°. The structure of the connecting portion facilitates arc striking, especially guiding the arc in the arc striking area, facilitating rapid arc extinguishing, and having good product breaking performance.

[0032] A magnetic conductive sheet 5 is provided in the space formed by the connecting portion 42 and the arc striking portion 41 to increase the magnetism, facilitate rapid arc striking and arc extinguishing, and improve the breaking performance of the product.

[0033] The utility model further comprises a tripper 6, which is arranged in the housing 1, and a first exhaust channel 71 is formed between the tripper 6 and the arc extinguishing chamber 3. Specifically, an exhaust notch 61 is provided on the tripper 6, and the exhaust notch 61 is connected to the first exhaust channel 71. The provision of the first exhaust channel and the exhaust notch facilitates rapid heat dissipation at the arc extinguishing chamber, facilitates arc extinguishing, and improves the breaking performance of the product.

[0034] The utility model also includes a first arc-striking piece 81, a second arc-striking piece 82 is provided on the outer side of the first arc-striking piece 81, the second arc-striking piece 82 and the first arc-striking piece 81 are arranged in close contact with each other, and an arc-striking area 83 is provided between the first arc-striking piece 81 and the static contact piece 4. Specifically, a second exhaust channel 72 is provided between the second arc-striking piece 82 and the inner wall of the housing 1, and the first arc-striking piece 81 protrudes toward the arc-striking area 83 to form a convex block portion 811. The provision of the second arc-striking piece increases the area of ​​the magnetic yoke iron, improves the arc-striking effect, and facilitates rapid arc-striking. The provision of the second exhaust channel facilitates rapid heat dissipation at the fast arc-extinguishing chamber, facilitates arc extinguishing, and improves the breaking performance of the product.

[0035] The housing 1 includes a first housing 11 and a second housing 12. The first housing 11 is provided with a first mounting column 111, the second housing 12 is provided with a second mounting column 121, the first mounting column 111 is provided with a first mounting hole 112, the second mounting column 121 is provided with a second mounting hole 122, the first mounting column 111 is inserted into the second mounting hole 122, the first housing 11 and the second housing 12 are riveted together by rivets, the first mounting column 111 and the second mounting column 121 are arranged at the static contact piece 4 and limit the static contact piece 4. The first housing and the second housing are provided with a first mounting column and a second mounting column, and the first mounting column is inserted into the second mounting hole of the second mounting column, the first mounting hole and the second mounting hole are coaxially arranged, and the rivet passes through the first mounting hole and the second mounting hole for riveting. In this way, the thickness of the mounting column outside the rivet is 0.8 mm, creepage at the rivet is avoided, and the product has better safety performance. The connection of the rivet prevents the heat and impact generated by the dynamic and static contacts from separating the housings, and the product has a long service life.

[0036] In the description of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships 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, be constructed and operate in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0037] In the description of the present utility model, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances. In addition, in the description of the present utility model, unless otherwise specified, "plurality" means two or more.

[0038] Technical personnel should note: Although the utility model has been described according to the above specific implementation methods, the utility model concept is not limited to this utility model. Any modification using the utility model concept will be included in the scope of protection of the utility model patent right.

Claims

1. A miniature circuit breaker, comprising a housing (1), characterized in that: Also includes: A movable contact piece (2) is arranged in the housing (1); An arc extinguishing chamber (3) is arranged in the housing (1), the arc extinguishing chamber (3) comprising an arc extinguishing frame (31) and an arc extinguishing grid (32), the arc extinguishing grid (32) being arranged on the arc extinguishing frame (31), the arc extinguishing grid (32) comprising a plurality of pieces, and an arc extinguishing notch (321) being arranged on the arc extinguishing grid (32); A stationary contact piece (4) is arranged in a housing (1); the moving contact piece (2) has a first position in contact with the stationary contact piece and a second position separated from the stationary contact piece (4); the stationary contact piece (4) comprises an arc striking portion (41); the arc striking portion (41) is arranged in front of an arc extinguishing grid piece (32); and a projection of an end of the stationary contact piece (4) on a plane falls within an arc extinguishing notch (321) of the arc extinguishing grid piece (32).

2. A miniature circuit breaker according to claim 1, characterized in that The arc extinguishing grid (32) comprises an arc guiding foot (322), the arc guiding foot (322) is opened to form the arc extinguishing notch (321), and the end of the arc striking portion (41) is provided with a chamfer or a slope (411).

3. A miniature circuit breaker according to claim 1, characterized in that The stationary contact piece (4) is provided with a connecting portion (42), the connecting portion (42) is connected to the arc striking portion (41) via an arc portion (43), and the connecting portion (42), the arc portion (43) and the connecting portion (42) are in a V shape.

4. A miniature circuit breaker according to claim 3, characterized in that The angle a formed by the connecting portion (42) and the arc striking portion (41) is 10° to 15°, and the angle b formed by the mounting portion (44) on the stationary contact piece (4) and the connecting portion (42) is 145° to 155°.

5. A miniature circuit breaker according to claim 3, characterized in that A magnetic conductive sheet (5) is provided in the space formed by the connecting portion (42) and the arc-starting portion (41).

6. A miniature circuit breaker according to claim 1, characterized in that It also includes a trip device (6) disposed in the housing (1), wherein a first exhaust passage (71) is formed between the trip device (6) and the arc extinguishing chamber (3).

7. A miniature circuit breaker according to claim 6, characterized in that The release device (6) is provided with an exhaust notch (61), and the exhaust notch (61) is connected to the first exhaust channel (71).

8. A miniature circuit breaker according to claim 1, characterized in that It also comprises a first arc-striking piece (81), a second arc-striking piece (82) is provided on the outer side of the first arc-striking piece (81), the second arc-striking piece (82) and the first arc-striking piece (81) are arranged in contact with each other, and an arc-striking area (83) is provided between the first arc-striking piece (81) and the stationary contact piece (4).

9. A miniature circuit breaker according to claim 8, characterized in that A second exhaust channel (72) is provided between the second arc-starting piece (82) and the inner wall of the shell (1), and the first arc-starting piece (81) protrudes toward the arc-starting area (83) to form a convex block portion (811).

10. A miniature circuit breaker according to claim 1, characterized in that The shell (1) comprises a first shell (11) and a second shell (12); the first shell (11) is provided with a first mounting column (111), the second shell (12) is provided with a second mounting column (121), the first mounting column (111) is provided with a first mounting hole (112), the second mounting column (121) is provided with a second mounting hole (122), the first mounting column (111) is inserted into the second mounting hole (122), the first shell (11) and the second shell (12) are riveted together by rivets, and the first mounting column (111) and the second mounting column (121) are arranged at the stationary contact piece (4) and limit the stationary contact piece (4).

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