Molded case circuit breaker

Abstract

The utility model discloses a molded case circuit breaker, which comprises a base, an arc extinguish chamber, a first wiring terminal and a protective cover, the arc extinguish chamber and the first wiring terminal are arranged on the base, and the first wiring terminal is located behind the arc extinguish chamber; the first wiring terminal comprises a first wiring frame and a first wiring screw, and the first wiring screw is connected to the upper part of the first wiring frame; the protective cover comprises a baffle and a cover body. The baffle comprises an upper baffle part and a lower baffle part; the upper blocking part is located between the first wiring screw and the arc extinguish chamber; one surface, far away from the arc extinguish chamber, of the lower blocking part and the cover body form an accommodating space; the upper part of the first wiring frame is positioned in the accommodating space; a ventilation structure is arranged on the upper blocking part and / or the lower blocking part; the exhaust device has the characteristic of timely exhaust.

Description

Technical Field

[0001] This application relates to the field of low-voltage electrical appliances, specifically a molded case circuit breaker. Background Technology

[0002] Generally, molded case circuit breakers use a terminal block and screw connection for wiring. However, in some specific situations, a wiring structure using a first terminal block and screw connection is also used. Because the first terminal block is relatively high, and molded case circuit breakers are generally multi-pole structures, the creepage distance between the first terminal blocks of adjacent pole wiring structures will be relatively small.

[0003] A common practice is to cover the first terminal block with an insulating cover to ensure a suitable creepage distance between the two poles. For circuit breakers, one set of first terminal blocks is located behind the arc-extinguishing chamber. However, existing insulating covers lack vents, so gas from the arc-extinguishing chamber direction can only bypass the cover for release. This venting effect is clearly not ideal, and if venting is not timely, it may cause the circuit breaker to explode.

[0004] Therefore, how to provide a more reasonable structure that can both meet the creepage distance requirements and improve the exhaust effect is a question worth considering. Summary of the Invention

[0005] In view of this, the purpose of this application is to overcome the shortcomings of the prior art and to provide a molded case circuit breaker.

[0006] This application provides: a molded case circuit breaker, comprising a base, an arc-extinguishing chamber, a first terminal block, and a protective cover; both the arc-extinguishing chamber and the first terminal block are disposed on the base, and the first terminal block is located behind the arc-extinguishing chamber; the first terminal block includes a first wiring frame and a first wiring screw, the first wiring screw being connected to the upper part of the first wiring frame; wherein, the protective cover includes a baffle and a cover body; the baffle includes an upper baffle and a lower baffle; the upper baffle is located between the first wiring screw and the arc-extinguishing chamber; the side of the lower baffle away from the arc-extinguishing chamber and the cover body together form an accommodating space, the upper part of the first wiring frame being located in the accommodating space; a venting structure is provided on the upper baffle and / or the lower baffle.

[0007] In some embodiments of this application, the ventilated structure includes a first ventilated through hole formed on the upper baffle; the orthographic projection of the first wiring screw on the upper baffle is a closed area, and the first ventilated through hole is distributed on one or both sides of the closed area.

[0008] In some embodiments of this application, the lower stop is inserted into the base, and the upper stop and the first vent hole are both higher than the base.

[0009] In some embodiments of this application, the ventilated structure includes a second ventilated through hole formed on the lower baffle; the upper part of the first wiring frame has two corner positions, and the second ventilated through hole is disposed near the corner positions.

[0010] In some embodiments of this application, the cover includes two spaced-apart side plates and a connecting portion connecting the two side plates. Both the side plates and the connecting portion are connected to the surface of the lower baffle away from the arc-extinguishing chamber. The first wiring screw penetrates the connecting portion. Both side plates are continuous bending structures and each includes a first bend. The two corners of the upper part of the first wiring frame are located at the two first bends, respectively.

[0011] In some embodiments of this application, the ventilated structure includes a third ventilated through hole formed on the lower baffle, the third ventilated through hole being located next to the side plate and being lower than the second ventilated through hole in the height direction.

[0012] In some embodiments of this application, the first wiring frame includes a frame-shaped portion and a blocking portion, the frame-shaped portion having a hollow portion; the blocking portion is connected to the side of the frame-shaped portion near the lower stop portion, and the blocking portion at least partially blocks the hollow portion of the frame-shaped portion; the third vent hole is within the blocking range of the blocking portion, and there is a gap between the blocking portion and the lower stop portion.

[0013] In some embodiments of this application, the baffle is an overall straight plate structure.

[0014] In some embodiments of this application, a middle cover is also included, which is fixed to the base; the base has a slot, the lower stop is inserted into the slot, and the upper stop extends into the middle cover.

[0015] In some embodiments of this application, the number of arc-extinguishing chambers is at least two, and the number of first terminals and protective covers corresponds to the number of arc-extinguishing chambers.

[0016] The advantages of this application compared to the prior art are:

[0017] Because the enclosure is connected to the side of the lower baffle away from the arc-extinguishing chamber to form a receiving space, the upper part of the first terminal frame is located in the receiving space, which increases the creepage distance between the first terminal frames of each phase of the circuit breaker. Furthermore, because the baffle has a venting structure, some of the gas from the arc-extinguishing chamber can be discharged through the venting structure. Compared to the existing technology that completely bypasses the protective cover, this structure not only ensures the creepage distance but also improves the venting effect. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 A perspective view of a molded case circuit breaker according to an embodiment of this application is shown;

[0020] Figure 2 This diagram shows a molded case circuit breaker according to an embodiment of the present application after removing components such as the center cover;

[0021] Figure 3 A schematic diagram of the protective cover and the first terminal block in an embodiment of this application is shown;

[0022] Figure 4 A schematic diagram of the protective cover in an embodiment of this application is shown;

[0023] Figure 5 A front view of the protective cover in an embodiment of this application is shown;

[0024] Figure 6 A schematic diagram of the first wiring frame in an embodiment of this application is shown;

[0025] Figure 7 A partial cross-sectional view of the protective cover and the first terminal block in an embodiment of this application is shown. Detailed Implementation

[0026] The embodiments of this application 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 application, and should not be construed as limiting this application.

[0027] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application 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 a limitation of this application.

[0028] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0029] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0030] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature. Example

[0031] like Figure 1-7 As shown, an embodiment of this application is a molded case circuit breaker, which includes a base 100, an arc-extinguishing chamber 300, a first terminal block 200, and a protective cover 400.

[0032] The base 100 is made of insulating material and is part of the circuit breaker housing. The base 100 has space for the main circuit conductors. Since the molded case circuit breaker in this embodiment is a 3-pole molded case circuit breaker, there are three main circuit conductor installation spaces, which are arranged sequentially along the width of the base 100.

[0033] The middle cover 150 is made of insulating material and is also part of the circuit breaker housing. The middle cover 150 is located above the base 100 and is fastened to the base 100 with screws.

[0034] The main circuit conductor is not a single conductor, but is composed of multiple conductors. In this embodiment, the main circuit conductor includes two terminal blocks, a moving contact, a stationary contact, and other components. Since the specific components of the main circuit conductor are common knowledge in the art, they will not be described in detail here.

[0035] There are three arc-extinguishing chambers 300, located in the installation spaces of the three main circuit conductors. The function of the arc-extinguishing chambers 300 is to extinguish the electric arc generated when the moving and stationary contacts separate. During the breaking process, some insulating materials inside the circuit breaker will generate gas under the burning of the electric arc, and at least some of the gas will be discharged from the rear of the arc-extinguishing chambers 300.

[0036] There are three first terminals 200, each including a first terminal frame 301 and a first terminal screw 302. The first terminals 200 are located behind the three arc-extinguishing chambers 300 (here, "behind" can also be understood as the direction of gas flow, flowing through the arc-extinguishing chambers 300 first and then to the first terminals 200). One terminal plate of each main circuit conductor is connected to one first terminal 200, and the connection method is that the terminal plate extends into the first terminal frame 301.

[0037] There are three second terminals, each including a second terminal block and a second terminal screw. The other terminal block of each main circuit conductor is connected to one of the second terminals, with the terminal block extending into the second terminal block.

[0038] There are three protective covers 400, which are respectively installed on the three first wiring frames 301 to increase the creepage distance between two adjacent first wiring frames 301. Since the protective covers 400 and the first wiring frames 301 have the same structure, taking one of them as an example, the protective cover 400 includes a baffle 401 and a cover body 402.

[0039] The baffle 401 includes an upper baffle 401a and a lower baffle 401b. The upper baffle 401a is located between the first wiring screw 302 and the arc-extinguishing chamber 300. Since the first wiring screw 302 is connected above the first wiring frame 301, the upper baffle 401a is in this position to minimize the ablation of the first wiring screw 302 by the gas from the arc-extinguishing chamber 300.

[0040] The side of the lower baffle 401b away from the arc-extinguishing chamber 300, together with the cover 402, forms a receiving space F1, in which the upper part of the first wiring frame 301 is located. Here, the lower baffle 401b is located between the first wiring frame 301 and the arc-extinguishing chamber 300. The lower baffle 401b and the cover 402 together accommodate the upper part of the first wiring frame 301, which can improve the creepage distance between two adjacent first wiring frames 301.

[0041] Here, the base 100 has a slot 101 (each polar space has one), the lower stop 401b is inserted into the slot 101, and the upper stop 401a extends into the middle cover 150.

[0042] As for baffle 401, it has a straight plate structure. Here, straight plate structure means that baffle 401 is in a straight line shape when viewed from the side.

[0043] A venting structure is installed on the baffle 401. Since the baffle 401 is divided into an upper baffle 401a and a lower baffle 401b, the venting structure can be installed on the upper baffle 401a, the lower baffle 401b, or both. This venting structure means that at least a portion of the gas from the arc-extinguishing chamber 300 can be directly discharged through the venting structure, without having to completely bypass the protective cover 400 for exhaust as in existing technologies. This venting structure design allows for timely exhaust and prevents the circuit breaker casing from cracking due to insufficient exhaust.

[0044] There are many ways to open a breathable structure. This embodiment contains three methods at the same time. Of course, it can also contain only one method or a combination of two methods.

[0045] In the first method, the ventilated structure includes a first vent hole S100, which is located on the upper baffle 401a. The projected portion of the first wiring screw 302 onto the upper baffle 401a forms a closed area M1. This closed area M1 means that this portion of the upper baffle 401a is sealed and airtight. The first vent holes S100 are distributed on both sides of the closed area M1. This arrangement uses the closed area M1 to block a large amount of gas directly facing the first wiring screw 302, allowing only a small amount of gas to pass through the first vent hole S100 and still blow over the first wiring screw 302. This design is a result of considering both exhaust performance and the protection of the wiring screw.

[0046] In this configuration, both the upper stop 401a and the first vent S100 are positioned above the base 100, because the lower stop 401b is inserted into the slot 101 of the base 100.

[0047] In this method, the number of first vent holes S100 can be two or more. Furthermore, the shape of the first vent holes S100 can be varied; for example, it can be a racetrack-shaped structure, a circle, a rectangle, a square, a triangle, etc. Any shape is acceptable as long as it allows for air ventilation.

[0048] In the second embodiment, the ventilated structure includes a second vent S200. Here, the first wiring frame 301 includes a frame-shaped portion 301a and a blocking portion 301b. The frame-shaped portion 301a is generally rectangular. The frame-shaped portion 301a includes four corner positions 3010, two of which are located within the receiving space. These two corner positions 3010 are also referred to as the upper corner positions 3010 of the first wiring frame 301.

[0049] The second vent S200 is located near the two corner positions 3010. Here, there are two second vent S200s, located next to the two corner positions 3010. Alternatively, there can be only one second vent S200, in which case it is located next to only one of the corner positions 3010.

[0050] The design of this second vent S200 allows gas to be discharged from the corner position 3010 of the first wiring frame 301 as much as possible, which is a comprehensive consideration of exhaust performance and reducing the impact of gas on the wiring structure.

[0051] The housing 402 includes two side plates 402a and a connecting portion 402b. The two side plates 402a are spaced apart and connected by the connecting portion 402b. Both the side plates 402a and the connecting portion 402b are connected to the surface of the lower stop 401b away from the arc-extinguishing chamber 300, thus forming a receiving space with the lower stop 401b. The connecting portion 402b has a clearance groove 402c, through which the first wiring screw 302 can penetrate. The side plate 402a has a continuously bent structure, designed to better fit the first wiring frame 301 and the first wiring screw 302. Both side plate portions 402a here include the first bend 402d. The two corner positions 3010 of the upper part of the first wiring frame 301 mentioned above are located in the two first bends respectively. It can also be said that the second ventilation hole S200 is opened near the first bend.

[0052] The design of the side plate 402a and the connecting part 402b fits very well with the first wiring frame 301 and the first wiring screw 302, effectively ensuring the creepage distance.

[0053] The third method involves a venting structure including a third venting hole S300. The third venting hole S300 is located on one side of the side plate portion 402a, and its position is lower than that of the second venting hole S200. In other words, in the height direction of the circuit breaker, the position of the third venting hole S300 is lower than that of the second venting hole S200.

[0054] The addition of the third vent S300 further improves exhaust performance.

[0055] For the first wiring frame 301, its blocking part 301b is connected to the side of the frame-shaped part 301a near the lower stop part 401b. That is to say, the blocking part 301b at least blocks a portion of the hollow part 301c of the frame-shaped part 301a. Here, the hollow part 301c is mainly for passing through terminal blocks and external wires (or wiring lugs). The third vent hole S300 is blocked by the blocking part 301b. However, this does not mean that the blocking part 301b completely blocks the third vent hole S300; rather, it means that the third vent hole S300 is within the blocking range of the blocking part 301b. There is a gap between the blocking part 301b and the lower stop part 401b, so that gas can be discharged from the third vent hole S300 and then dispersed in all directions after encountering the blocking part 301b. This blocking part 301b can prevent gas from blowing directly into the hollow part 301c, avoiding the impact on the terminal block and external wires, while also ensuring the exhaust effect.

[0056] Of course, the above structure is not only applicable to three-pole molded case circuit breakers, but also to single-pole, two-pole, and four-pole molded case circuit breakers. Similarly, these molded case circuit breakers can be thermo-magnetic, electronic, or electrically operated.

[0057] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0058] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A molded case circuit breaker comprising a base, an arc extinguishing chamber, a first terminal and a protective cover; the arc extinguishing chamber and the first terminal are arranged on the base, and the first terminal is located behind the arc extinguishing chamber; the first terminal comprises a first terminal frame and a first terminal screw, and the first terminal screw is connected to the upper part of the first terminal frame; characterized in that: The protective cover comprises a baffle and a cover body; the baffle comprises an upper baffle part and a lower baffle part; the upper baffle part is between the first wiring screw and the arc extinguishing chamber; the lower baffle part, together with the cover body, forms a containing space on the side away from the arc extinguishing chamber, and the upper part of the first wiring frame is in the containing space; the upper baffle part and / or the lower baffle part is provided with a ventilation structure.

2. A molded case circuit breaker according to claim 1, wherein: The ventilation structure comprises a first ventilation through hole provided on the upper baffle part; the orthographic projection of the first wiring screw on the upper baffle part is a closed area, and the first ventilation through hole is distributed on one side or both sides of the closed area.

3. A molded case circuit breaker according to claim 2, wherein: The lower baffle part is in plug-in cooperation with the base, and the upper baffle part and the first ventilation through hole are higher than the base.

4. A molded case circuit breaker according to claim 1, wherein: The ventilation structure comprises a second ventilation through hole provided on the lower baffle part; the upper part of the first wiring frame has two corner positions, and the second ventilation through hole is arranged close to the corner positions.

5. A molded case circuit breaker according to claim 3, wherein: The cover body comprises two spaced side plate parts and a connecting part connecting the two side plate parts, the side plate parts and the connecting part are connected to the surface of the lower baffle part away from the arc extinguishing chamber, and the first wiring screw penetrates the connecting part; the two side plate parts are continuous bending structures and each comprises a first bending part, and the two corner positions of the upper part of the first wiring frame are respectively located in the two first bending parts.

6. A molded case circuit breaker according to claim 4, wherein: The ventilation structure comprises a third ventilation through hole provided on the lower baffle part, the third ventilation through hole is beside the side plate part and lower than the second ventilation through hole in the height direction.

7. A molded case circuit breaker according to claim 6 wherein: The first wiring frame comprises a frame part and a blocking part, the frame part has a hollow part; the blocking part is connected to the side of the frame part close to the lower baffle part, and the blocking part at least shields part of the hollow part of the frame part; The third ventilation through hole is in the shielding range of the blocking part, and there is a gap between the blocking part and the lower baffle part.

8. The molded case circuit breaker of claim 1, wherein: The baffle is a straight plate structure as a whole.

9. The molded case circuit breaker of claim 1, wherein: Further comprising a middle cover fixed on the base; the base is provided with a slot, the lower baffle part is plug-in in the slot, and the upper baffle part extends into the middle cover.

10. A molded case circuit breaker according to any one of claims 1-9, characterized in that: The number of arc extinguishing chambers is at least 2, and the number of first wiring terminals and protective covers corresponds to the number of arc extinguishing chambers.

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