Miniature circuit breaker

Abstract

The present disclosure relates to a circuit breaker comprising at least one pole arranged in sequence in a first direction, each pole comprising: a housing comprising a first cavity and a second cavity separated by a partition; a stationary contact assembly comprising a first stationary contact disposed in the first cavity and a second stationary contact disposed in the second cavity, wherein the first stationary contact and the second stationary contact are separated from each other; a movable contact assembly comprising a movable contact body and a first movable contact extending from the movable contact body into the first cavity and a second movable contact extending from the movable contact body into the second cavity, wherein the first movable contact and the second movable contact are capable of simultaneously contacting or separating from the first stationary contact and the second stationary contact, respectively; a first arc extinguishing system disposed in the first cavity and configured to extinguish a first arc generated when the first movable contact separates from the first stationary contact; and a second arc extinguishing system disposed in the second cavity and configured to extinguish a second arc generated when the second movable contact separates from the second stationary contact.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a miniature circuit breaker. BACKGROUND

[0002] A miniature circuit breaker is a key device to ensure the safety of electricity and circuit switching, which is widely used in various electrical terminal power distribution devices. The miniature circuit breaker is composed of a tripping and closing mechanism, a contact mechanism, a tripping mechanism, a current thermal component, an arc extinguishing system, etc. The working principle is as follows: the tripping mechanism and the current thermal component are used to realize overload and short-circuit protection, when the current through the coil in the current thermal component is greater than the set current value, the moving iron core of the electromagnetic tripping device acts, pushes the striking lever to hit the operating mechanism, so that the operating mechanism is unlocked, the circuit breaker is tripped and the circuit is disconnected, thereby realizing the overload and short-circuit protection of the circuit. When the circuit fault is eliminated, the tripping and closing mechanism is operated to close the circuit and connect the circuit.

[0003] Since the moving contact and the static contact in the contact mechanism will generate an arc when they are separated, an arc extinguishing system is needed to extinguish the arc to reduce the corrosion of the circuit breaker. Due to the volume limitation of the miniature circuit breaker and the relatively large volume of the tripping mechanism, the volume of the arc extinguishing system is small, which limits the arc extinguishing effect and further limits the breaking capacity and rated current of the miniature circuit breaker.

[0004] In addition, the current miniature circuit breaker usually has only one pair of moving contact and static contact, due to the volume limitation of the miniature circuit breaker, the contact opening distance is limited, so it is not possible to achieve a high rated voltage and rated current.

[0005] In recent years, people have increasingly demanded that the miniature circuit breaker has a higher rated voltage and rated current to meet the growing application requirements. Usually, in some direct current applications, such as data centers with high energy storage requirements, in order to improve power distribution efficiency, save energy and space, it is necessary to increase the rated voltage and rated current of the miniature circuit breaker. In some special applications, such as the photovoltaic industry, due to the high voltage of the photovoltaic panel string, for example, up to 1500V, a miniature circuit breaker with a higher rated voltage and rated current is needed. SUMMARY

[0006] Therefore, the purpose of the present disclosure is to provide a miniature circuit breaker with two pairs of moving contacts and static contacts in series and corresponding two arc extinguishing systems, which increases the contact opening distance and improves the arc voltage, so that the miniature circuit breaker has a higher rated voltage and rated current.

[0007] The present disclosure achieves the above-mentioned object by a miniature circuit breaker. The miniature circuit breaker comprises at least one pole arranged in sequence in a first direction, each of the at least one pole comprising an incoming terminal assembly and an outgoing terminal assembly, and further comprising: a housing comprising a first cavity and a second cavity separated by a partition; a stationary contact assembly comprising a first stationary contact disposed in the first cavity and a second stationary contact disposed in the second cavity, wherein the first stationary contact and the second stationary contact are separated from each other; a movable contact assembly comprising a movable contact body and a first movable contact extended from the movable contact body into the first cavity and a second movable contact extended from the movable contact body into the second cavity, wherein the first movable contact and the second movable contact are capable of being simultaneously in contact with or separated from the first stationary contact and the second stationary contact, respectively; a first arc extinguishing system disposed in the first cavity and configured to extinguish a first arc generated when the first movable contact is separated from the first stationary contact; and a second arc extinguishing system disposed in the second cavity and configured to extinguish a second arc generated when the second movable contact is separated from the second stationary contact.

[0008] In an embodiment, when the miniature circuit breaker is in a closed state, the current flows through the following components in sequence: the incoming terminal assembly, the first stationary contact, the first movable contact, the movable contact body, the second movable contact, the second stationary contact, and the outgoing terminal assembly.

[0009] In an embodiment, the stationary contact assembly further comprises an electrically conductive component located between the first movable contact and the second movable contact, and a first end of the electrically conductive component is electrically connected to the incoming terminal assembly and a second end of the electrically conductive component is electrically connected to the first stationary contact, such that the current flows to the first stationary contact through the electrically conductive component.

[0010] In an embodiment, each of the poles further comprises an electromagnetic trip assembly disposed in the housing and at least partially located outside the first cavity and the second cavity, the first cavity comprises a first opening open towards the electromagnetic trip assembly and a second opening open towards an air outlet of the miniature circuit breaker.

[0011] In an embodiment, the second cavity comprises a third opening open towards the electromagnetic trip assembly and a fourth opening open towards the air outlet of the miniature circuit breaker.

[0012] In an embodiment, each of the poles further comprises a first gas generating member and a second gas generating member, the first gas generating member is disposed on a side of the partition facing the first cavity to be capable of generating a first gas under the action of the first arc, and the second gas generating member is disposed on a side of the partition facing the second cavity to be capable of generating a second gas under the action of the second arc.

[0013] In an embodiment, a portion of the first gas flows through the following components: the first movable contact and the first stationary contact, the first arc extinguishing system, the first opening, the electromagnetic trip assembly, the first movable contact and the first stationary contact; another portion of the first gas flows through the following components: the first movable contact and the first stationary contact, the first arc extinguishing system, the second opening, the gas outlet.

[0014] In an embodiment, a portion of the second gas flows through the following components: the second movable contact and the second stationary contact, the second arc extinguishing system, the third opening, the electromagnetic trip assembly, the second movable contact and the second stationary contact; another portion of the second gas flows through the following components: the second movable contact and the second stationary contact, the second arc extinguishing system, the fourth opening, the gas outlet.

[0015] In an embodiment, the each pole further comprises a first guide plate arranged at the second opening and for guiding the first gas, and a second guide plate arranged at the fourth opening and for guiding the second gas.

[0016] In an embodiment, the first guide plate and / or the second guide plate is / are inclinedly extended by a rear wall of the housing towards the interior of the housing.

[0017] In an embodiment, the movable contact assembly has a U-shape.

[0018] In an embodiment, the electrically conductive part is formed in one piece with the first stationary contact. BRIEF DESCRIPTION OF DRAWINGS

[0019] The advantages and objects of the present disclosure can be better understood from the following detailed description of the preferred embodiments of the present disclosure when read in light of the accompanying drawings. The drawings are not drawn to scale in order to better show the relationship between the various components. In the drawings:

[0020] Figure 1 An internal cutaway view of a miniature circuit breaker of one embodiment of the present disclosure is shown, viewed in a first direction;

[0021] Figure 2 An internal cutaway view of a miniature circuit breaker of one embodiment of the present disclosure is shown, viewed in a direction opposite to the first direction;

[0022] Figure 3 A partial cutaway view of a miniature circuit breaker of one embodiment of the present disclosure is shown, wherein the electrically conductive parts of the movable contact assembly and the stationary contact assembly are shown;

[0023] Figure 4 A partial cutaway view of a miniature circuit breaker of one embodiment of the present disclosure is shown, wherein the first arc extinguishing system and the second arc extinguishing system are shown;

[0024] Figure 5 A partial schematic diagram of the first cavity of a miniature circuit breaker according to an embodiment of the present disclosure is shown;

[0025] Figure 6 A partial internal schematic diagram of a miniature circuit breaker according to an embodiment of the present disclosure is shown;

[0026] Figure 7 A partial internal schematic diagram of a miniature circuit breaker according to an embodiment of the present disclosure, viewed in a direction opposite to a first direction, is shown, illustrating the current direction; and

[0027] Figure 8 A partial internal schematic diagram of a miniature circuit breaker according to an embodiment of the present disclosure is shown, viewed along a first direction, in which the direction of current is shown. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this disclosure. All other embodiments obtained by those skilled in the art based on the described embodiments of this disclosure without creative effort are within the scope of protection of this disclosure.

[0029] Unless otherwise defined, the technical or scientific terms used in this disclosure shall have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The terms “first,” “second,” and similar terms used in this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as “having,” “including,” or “comprising” mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as “upper,” “lower,” “left,” and “right” are used only to indicate relative positioning; when the absolute positioning of the described object changes, the relative positioning may also change accordingly.

[0030] The accompanying drawings in this specification are schematic diagrams used to illustrate the concept of this disclosure, and schematically show the shapes of the parts and their interrelationships.

[0031] Below, refer to Figures 1 to 8 The embodiments according to this disclosure are described in detail.

[0032] Figure 1 An internal cross-sectional view of a miniature circuit breaker according to an embodiment of the present disclosure is shown, viewed along a first direction. Figure 2An internal cutaway view of a miniature circuit breaker of one embodiment of the present disclosure is shown, viewed in a direction opposite the first direction. In Figure 1 , the first direction is a direction in which the plane of the drawing sheet faces inward. In Figure 2 , the first direction is a direction in which the plane of the drawing sheet faces outward.

[0033] A miniature circuit breaker according to the present disclosure can include at least one pole arranged in the first direction in sequence, wherein an internal cutaway view of one pole viewed in a different direction is shown as in Figure 1 and 2 . In other embodiments, the miniature circuit breaker can include two, three, four such poles. Each pole can include a line-in terminal assembly 1 and a line-out terminal assembly 2. Figure 1 The two circles in Figure 4 only schematically show the positions of the line-in terminal assembly and the line-out terminal assembly, and not all components in the circles are line-in terminal assemblies or line-out terminal assemblies. In addition, each pole further includes a housing 3, a stationary contact assembly 4, a movable contact assembly 5, a first arc extinguishing system 6, a second arc extinguishing system 7, and an electromagnetic tripping assembly 8. The housing 3 includes a first cavity and a second cavity separated by a partition 31, as shown in Figure 4 . The stationary contact assembly 3 includes a first stationary contact 41 disposed in the first cavity and a second stationary contact 42 disposed in the second cavity, the first stationary contact 41 and the second stationary contact 42 being separated from each other, as shown in Figures 1 to 3 . The movable contact assembly 5 includes a movable contact body 50, a first movable contact 51 extending from the movable contact body 50 into the first cavity, and a second movable contact 52 extending from the movable contact body 50 into the second cavity, the first movable contact 51 and the second movable contact 52 being capable of simultaneously contacting or separating from the first stationary contact 41 and the second stationary contact 42, respectively, so as to achieve closing or opening of the circuit breaker. The first arc extinguishing system 6 is disposed in the first cavity and is used to extinguish a first arc generated when the first movable contact 51 separates from the first stationary contact 41. The second arc extinguishing system 7 is disposed in the second cavity and is used to extinguish a second arc generated when the second movable contact 52 separates from the second stationary contact 42. The first arc extinguishing system 6 and the second arc extinguishing system 7 each have an arc chamber and a plurality of arc plates disposed in the arc chamber.

[0034] In embodiments of the present disclosure, the two pairs of movable contacts and stationary contacts described above are electrically connected in series. Specifically, when the movable contact assembly 5 contacts the stationary contact assembly 4, i.e., when the first movable contact 51 contacts the first stationary contact 41 and the second movable contact 52 contacts the second stationary contact 42, or in other words when the miniature circuit breaker is in a closed state, the current flows through the following components in sequence: the line-in terminal assembly 1, the first stationary contact 41, the first movable contact 51, the movable contact body 50, the second movable contact 52, the second stationary contact 42, and the line-out terminal assembly 2.

[0035] Considering the size of the miniature circuit breaker and the arrangement of the components, the movable contact assembly can have a U shape, as shown in Figure 3 Of course, the present disclosure is not limited thereto, and other shapes are possible.

[0036] By providing two pairs of movable and stationary contacts in the housing, the contact opening distance of the miniature circuit breaker of the present disclosure can be increased, for example, to twice that of a miniature circuit breaker that has only one pair of movable and stationary contacts.

[0037] Each pole of the miniature circuit breaker of the present disclosure also includes a bimetallic strip 16 disposed in the housing 3, which can separate the movable contact assembly from the stationary contact assembly to achieve tripping when the circuit is overloaded. The current flows through the bimetallic strip 16 first after flowing into the miniature circuit breaker from the line terminal assembly 1, and then flows into the first stationary contact 41.

[0038] In addition, as shown in Figure 1 The stationary contact assembly 4 also includes a conductive component 43. As shown in Figure 3 and 6 The conductive component 43 is located between the first movable contact 51 and the second movable contact 52. For example, the conductive component 43 can be located exactly between the first movable contact 51 and the second movable contact 52. As shown in Figure 1 and 6 The first end of the conductive component 43 (i.e., the end close to the bimetallic strip 16) is electrically connected to the line terminal assembly 1, and the second end (i.e., the end away from the bimetallic strip 16) is electrically connected to the first stationary contact 41, so that the current flows to the first stationary contact 41 through the conductive component 43. More precisely, the first end of the conductive component 43 is electrically connected to the bimetallic strip 16. It can also be said that the conductive component 43 is electrically connected to the bimetallic strip 16 through the first movable contact 51 and the second movable contact 52.

[0039] For example, the conductive component 43 can be integrally formed with the first stationary contact 41. Of course, the conductive component 43 can also be separate from the first stationary contact 41 and electrically connected to the first stationary contact 41 by other means. The conductive component 43 can be made of the same conductive material as the first stationary contact 41.

[0040] By providing the conductive component 43 in the middle, the current loop can be kept away from the housing, so that the temperature of the housing can be prevented from exceeding the standard temperature. For large current products, if the current loop is arranged on one side of the product, the heat generated by the current loop will be transferred to the housing, causing the temperature of the housing to exceed the standard temperature. The embodiments of the present disclosure avoid the above problems and have a longer service life.

[0041] Of course, the conductive component 43 of this disclosure is not limited to the space between the first moving contact 51 and the second moving contact 52. In other embodiments, the conductive component 43 can be located in the middle of the housing.

[0042] like Figure 4 As shown, the housing is divided into two independent cavities by the isolator 31, which separates the first arc from the second arc, thereby preventing a short circuit. For example, the isolator 31 is made of an insulating material, such as having the same material as the housing, like plastic.

[0043] It should be noted that the first cavity and the second cavity of this disclosure are not sealed and isolated from each other. For example... Figure 1 and 4 As shown, the first cavity includes a first opening 11 that opens toward the electromagnetic tripping assembly 8 and a second opening 12 that opens toward the outlet 15 of the miniature circuit breaker. Figure 2 and 4 As shown, the second cavity includes a third opening 13 that opens toward the electromagnetic tripping assembly 8 and a fourth opening 14 that opens toward the outlet 15 of the miniature circuit breaker.

[0044] Each pole of the miniature circuit breaker also includes a first gas-generating element and a second gas-generating element (not shown in the figure), the first gas-generating element being disposed on the isolator 31 facing the first cavity (i.e., Figure 4 The left side of the cavity is positioned to generate a first gas under the action of the first electric arc, and the second gas-generating element is disposed on the isolation member 31 facing the second cavity (i.e., Figure 4 One side of the right-hand cavity is designed to generate a second gas under the action of a second electric arc. For example, the first and second gas-generating elements are made of the same material, which is capable of rapidly decomposing to generate a large amount of gas under the action of an electric arc generated when the moving and stationary contacts come into contact. This gas can propel the electric arc to accelerate into the arc-extinguishing chamber. It should be noted that the first and second gases described herein may differ only in the cavity in which they are located.

[0045] Through the aforementioned multiple openings, the gas generated by the electric arc can each have two flow channels. For example, as Figure 1 As shown, a portion of the first gas flows through the following components: the first moving contact 51 and the first stationary contact 41, the first arc-extinguishing system 6, the first opening 11, the electromagnetic tripping assembly 8, the first moving contact 51 and the first stationary contact 41. Another portion of the first gas flows through the following components: the first moving contact 52 and the first stationary contact 41, the first arc-extinguishing system 6, the second opening 12, and the gas outlet 15. For example, as... Figure 2As shown, a portion of the second gas flows through the following components: the second moving contact 52 and the second stationary contact 42, the second arc extinguishing system 7, the third opening 13, the electromagnetic tripping assembly 8, the second moving contact 52 and the second stationary contact 42; another portion of the second gas flows through the following components: the second moving contact 52 and the second stationary contact 42, the second arc extinguishing system 7, the fourth opening 14, and the gas outlet 15.

[0046] like Figure 1 , 2 As shown in Figure 5, each pole of the miniature circuit breaker further includes a first guide plate 9 disposed at the second opening 12 for guiding the first gas, and a second guide plate 10 disposed at the fourth opening 14 for guiding the second gas. For example, the first guide plate 9 and / or the second guide plate 10 extend from the rear wall of the housing 3 inclined toward the interior of the housing and away from the corresponding arc-extinguishing system. The rear wall of the housing shown is... Figure 1 , 2 And the bottom wall shown in Figure 5. The inclined extension toward the interior of the casing is to allow the first or second arc to move toward the interior of the casing, prolonging its residence time in the corresponding arc extinguishing system, thereby improving the arc extinguishing efficiency. Figure 5 The first guide plate 9 shown extends obliquely to the upper left from the rear wall of the housing, guiding the first gas toward the wall of the housing, thereby prolonging the residence time of the first arc in the first arc extinguishing system and improving the arc extinguishing efficiency.

[0047] Furthermore, the design of the dual-flow air passage and guide plate allows the electric arc to enter the arc-extinguishing chamber more synchronously, providing better short-circuit protection.

[0048] like Figure 7 and 8 As indicated by the arrows, the current flows sequentially through the following components: inlet terminal assembly 1, bimetallic strip 16, conductive component 43, first stationary contact 41, first moving contact 51, moving contact body 50, second moving contact 52, second stationary contact 42, electromagnetic trip assembly 8, and outlet terminal assembly 2. This achieves a series connection of two pairs of moving and stationary contacts. It should be noted that... Figure 7 and 8 Only parts of the incoming terminal assembly 1 and the outgoing terminal assembly 2 are shown in the image.

[0049] The miniature circuit breaker disclosed herein increases the contact gap and improves the arc voltage by setting two pairs of moving contacts and stationary contacts connected in series, along with two corresponding arc-extinguishing systems, thus enabling higher rated voltage and rated current. Furthermore, the miniature circuit breaker of this disclosure has a compact structure and a long service life.

[0050] The technical features disclosed above are not limited to the combinations disclosed with other features, and other combinations between technical features can be made by those skilled in the art according to the purpose of the disclosure, and the purpose of the disclosure is achieved.

Claims

1. A miniature circuit breaker comprising at least one pole arranged in succession in a first direction, each of said at least one pole comprising an incoming terminal assembly (1) and an outgoing terminal assembly (2), characterized in that, Each pole further comprises: a housing (3) comprising a first cavity and a second cavity separated by a partition (31); a stationary contact assembly (4) comprising a first stationary contact (41) disposed in the first cavity and a second stationary contact (42) disposed in the second cavity, wherein the first stationary contact and the second stationary contact are separated from each other; a movable contact assembly (5) comprising a movable contact body (50) and a first movable contact (51) extended from the movable contact body into the first cavity and a second movable contact (52) extended from the movable contact body into the second cavity, wherein the first movable contact and the second movable contact are capable of being simultaneously in contact with or separated from the first stationary contact and the second stationary contact respectively; a first arc extinguishing system (6) disposed in the first cavity and used for extinguishing a first electric arc generated when the first movable contact is separated from the first stationary contact; and a second arc extinguishing system (7) disposed in the second cavity and used for extinguishing a second electric arc generated when the second movable contact is separated from the second stationary contact, wherein, when the miniature circuit breaker is in a closed state, the current flows through the following components in sequence: the line terminal assembly (1), the first stationary contact (41), the first movable contact (51), the movable contact body (50), the second movable contact (52), the second stationary contact (42), the outgoing line terminal assembly (2); and wherein the stationary contact assembly further comprises an electrically conductive component (43) located between the first movable contact and the second movable contact, and a first end of the electrically conductive component is electrically connected to the line terminal assembly and a second end of the electrically conductive component is electrically connected to the first stationary contact, so that the current flows to the first stationary contact through the electrically conductive component.

2. The miniature circuit breaker of claim 1, wherein, Each pole further comprises an electromagnetic trip assembly (8) disposed in the housing and at least partially located outside the first cavity and the second cavity, the first cavity comprises a first opening (11) open towards the electromagnetic trip assembly and a second opening (12) open towards an air outlet (15) of the miniature circuit breaker.

3. The miniature circuit breaker of claim 2, wherein, The second cavity comprises a third opening (13) open towards the electromagnetic trip assembly and a fourth opening (14) open towards the air outlet of the miniature circuit breaker.

4. The miniature circuit breaker of claim 3, wherein, Each pole further comprises a first gas generating member and a second gas generating member, the first gas generating member is disposed on a side of the partition (31) facing the first cavity to be capable of generating a first gas under the action of the first electric arc, and the second gas generating member is disposed on a side of the partition (31) facing the second cavity to be capable of generating a second gas under the action of the second electric arc.

5. The miniature circuit breaker of claim 4, wherein, Part of the first gas flows through the following components: the first movable contact (51) and the first stationary contact (41), the first arc extinguishing system (6), the first opening (11), the electromagnetic trip assembly (8), the first movable contact (51) and the first stationary contact (41); another part of the first gas flows through the following components: the first movable contact (51) and the first stationary contact (41), the first arc extinguishing system (6), the second opening (12), the air outlet (15).

6. The miniature circuit breaker of claim 4, wherein, A portion of the second gas flows through the following components: second moving contact (52) and second stationary contact (42), second arc extinguishing system (7), third opening (13), electromagnetic trip assembly (8), second moving contact (52) and second stationary contact (42); another portion of the second gas flows through the following components: second moving contact (52) and second stationary contact (42), second arc extinguishing system (7), fourth opening (14), gas outlet (15).

7. The miniature circuit breaker of claim 4, wherein, Each pole further comprises a first guide plate (9) arranged at the second opening (12) and configured to guide the first gas, and a second guide plate (10) arranged at the fourth opening (14) and configured to guide the second gas.

8. The miniature circuit breaker of claim 7, wherein, The first guide plate (9) and / or the second guide plate (10) extend obliquely from a rear wall of the housing towards the interior of the housing.

9. The miniature circuit breaker of claim 1, wherein, The moving contact assembly has a U-shape.

10. The miniature circuit breaker of claim 1, wherein, The electrically conductive part (43) is formed in one piece with the first stationary contact (41). The electrically conductive part (43) is formed in one piece with the first stationary contact (41).

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