Electronic molded case circuit breaker

Abstract

The utility model discloses an electronic molded case circuit breaker, which comprises a shell, an operating mechanism and a main loop conductor, the operating mechanism comprises a draw bar, and the main loop conductor comprises a thermal element and a first wiring board; the power supply also comprises a backup protector, and the backup protector comprises an electromagnetic release and a bimetallic strip. The thermal element comprises a fixed section, a connecting section and a wiring section, and the wiring section is higher than the fixed section; the fixed section is used for being fixed with a shell, the wiring section is used for being electrically connected with a first wiring board, and the connecting section is used for connecting the wiring section with the fixed section; the bimetallic strip is fixed on the surface, close to the fixed section, of the connecting section, and the electromagnetic release surrounds the wiring section; the traction rod comprises a first driving part and a second driving part, the first driving part is used for being matched with the bimetallic strip, and the second driving part is used for being matched with the electromagnetic release; the backup protector has an overload protection function.

Description

Technical Field

[0001] The present application relates to the electrical field of low-voltage switches, and in particular to an electronic molded case circuit breaker. Background Art

[0002] Thermal-magnetic molded case circuit breakers and electronic molded case circuit breakers are already relatively common molded case circuit breakers.

[0003] The traditional thermal-magnetic molded case circuit breaker relies on a bimetallic strip for overload protection and an electromagnetic system for short circuit protection. Since the bimetallic strip is integrated with the electromagnetic system, it is also called a thermal-magnetic molded case circuit breaker, such as the structure disclosed in CN211629021U.

[0004] The traditional electronic molded case circuit breaker only has an electronic tripping system (including mutual inductor, flux tripping device, control circuit board, etc.) and a backup protector (also known as an electromagnetic system). Overload protection and short-circuit protection are both completed by the electronic tripping system, and the backup protector serves as the biggest reliance for short-circuit protection (for example, in the event of failure of a few electronic tripping systems, it plays a role in short-circuit protection), such as the structure disclosed in CN211929415U.

[0005] That is to say, the existing backup protector only has an instantaneous tripping function but does not have an overload protection function, which is extremely detrimental to the protection of the product.

[0006] Therefore, how to design a backup protector that has both instantaneous protection and overload protection functions, and can ensure that the circuit breaker can provide protection after the electronic tripping system fails, will definitely be the development trend of electronic molded case circuit breakers. Summary of the invention

[0007] In view of this, the purpose of this application is to overcome the deficiencies in the prior art and to provide an electronic molded case circuit breaker.

[0008] The present application provides: an electronic molded case circuit breaker, which includes a shell, an operating mechanism and a main circuit conductor, the operating mechanism includes a traction rod, the main circuit conductor includes a thermal element and a first terminal block; wherein, it also includes a backup protector, the backup protector includes an electromagnetic release and a bimetallic strip; the thermal element includes a fixed section, a connecting section and a wiring section, the wiring section is higher than the fixed section; the fixed section is used to be fixed to the shell, the wiring section is used to be electrically connected to the first terminal block, and the connecting section is used to connect the wiring section to the fixed section; the bimetallic strip is fixed on the surface of the connecting section close to the fixed section, and the electromagnetic release is surrounded by the wiring section; the traction rod includes a first driving part and a second driving part, the first driving part is used to cooperate with the bimetallic strip, and the second driving part is used to cooperate with the electromagnetic release.

[0009] Compared with the prior art, this type of backup protector has a bimetallic strip design and a first drive part design on the traction rod. Even after the electronic tripping system of such an electronic molded case circuit breaker fails, overload protection and instantaneous protection can be achieved through the backup protector.

[0010] In some embodiments of the present application, the electromagnetic release includes an armature, an iron core and a bracket; the armature includes two first attraction arms, a first connecting arm and a first driving arm, the first connecting arm connects the two first attraction arms, one end of the first driving arm is connected to the first connecting arm, and the other end extends toward the second driving part; the iron core includes two second attraction arms and a second connecting arm, the second connecting arm connects the two second attraction arms, and the second attraction arm corresponds to the first attraction arm; the bracket is fixed to the second connecting arm, and the first attraction arm is rotatably connected to the bracket; the wiring segment is located between the two first attraction arms.

[0011] The electromagnetic release has a simple structure and can achieve instantaneous protection in a relatively stable manner.

[0012] In some embodiments of the present application, one end of the bimetallic strip is higher than the first connecting arm, the bending direction of the bimetallic strip is toward the direction of the first connecting arm, and an avoidance groove for avoiding the bimetallic strip is provided on the first connecting arm.

[0013] With this structure, the first connecting arm gives way to the bimetallic strip, which can make the backup protector more compact as a whole, help reduce the volume, and save space for other components inside the circuit breaker.

[0014] In some embodiments of the present application, the bracket includes a base plate, a side plate and a limit plate; the base plate is used to be fixed to the second connecting arm; there are two side plates, one end of which is connected to the base plate, and the first attraction arm is rotatably connected to the corresponding side plate; two limit plates are connected to each side plate, and the two limit plates are arranged on both sides of the rotation direction of the first attraction arm to prevent the first attraction arm from excessive rotation.

[0015] The design of the limit plate can prevent the first attraction arm from excessive rotation.

[0016] In some embodiments of the present application, the distance between the bimetallic strip and the first driving part is d, and the distance between the bimetallic strip and the second driving part is D, and D is greater than d.

[0017] This structure is suitable for the structure of bimetallic strip and electromagnetic release system, and can make the backup protector more compact.

[0018] In some embodiments of the present application, the electromagnetic release includes a first driving arm corresponding to the second driving part, and the first driving arm is located on one side of the first driving part.

[0019] With this structural design, since the first driving part is used to drive the bimetallic strip, such a structure can also be suitable for a compact design of the bimetallic strip and the backup protector.

[0020] In some embodiments of the present application, the first driving portion is connected to the second driving portion via a connecting wall, the connecting wall and the second driving portion together form a receiving groove, and the first driving arm is located in the receiving groove.

[0021] The use of this structure will be beneficial to the processing and forming of the first driving part and the second driving part on the traction rod, and improve the connection strength between the two.

[0022] In some embodiments of the present application, the electromagnetic release includes a first connecting arm, and the first driving arm is connected to the first connecting arm; when the electromagnetic release is not actuated, the first driving part is located directly above a portion of the first connecting arm.

[0023] The design adopting this structure will also be suitable for the compact design of electromagnetic release and bimetallic strip.

[0024] In some embodiments of the present application, the electronic molded case circuit breaker includes at least two-pole main circuit conductors, and the number of backup protectors is the same as the number of poles of the main circuit conductors.

[0025] With this structure of circuit breaker, each pole is equipped with a backup release that includes both overload protection and instantaneous protection, which can effectively play the corresponding protection function.

[0026] In some embodiments of the present application, the wiring segment is electrically connected to the first wiring board via a soft connection or a hard busbar.

[0027] With this structure, the two components can be electrically connected either through a soft connection or through a hard busbar. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0029] Figure 1 A three-dimensional diagram of an electronic molded case circuit breaker according to Embodiment 1 of the present application is shown;

[0030] Figure 2 A schematic diagram of the electronic molded case circuit breaker after the outer shell is removed is shown in Example 1 of the present application;

[0031] Figure 3 A schematic diagram of a thermal element in an electronic molded case circuit breaker according to Embodiment 1 of the present application is shown;

[0032] Figure 4 A schematic diagram of a traction rod in an electronic molded case circuit breaker in Example 1 of the present application is shown;

[0033] Figure 5 A diagram showing the relationship between the backup protector and the drawbar in the electronic molded case circuit breaker in Example 1 of the present application is shown;

[0034] Figure 6 A schematic diagram of an electromagnetic release in an electronic molded case circuit breaker in Example 1 of the present application is shown;

[0035] Figure 7 A diagram showing the relationship between the bimetallic strip and the drawbar in the electronic molded case circuit breaker of Example 1 of the present application is shown. DETAILED DESCRIPTION

[0036] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application.

[0037] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0038] In addition, the terms "primary" and "secondary" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, features defined as "primary" and "secondary" may explicitly or implicitly include one or more of the features. In the description of this application, "multiple" means two or more, unless otherwise clearly and specifically defined.

[0039] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like 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 an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0040] In the present application, unless otherwise clearly specified and limited, when a main feature is “above” or “below” a second feature, it can mean that the main feature and the second feature are in direct contact, or the main feature and the second feature are in indirect contact through an intermediate medium. Moreover, when a main feature is “above”, “above” or “above” a second feature, it can mean that the main feature is directly above or obliquely above the second feature, or simply means that the main feature is higher in level than the second feature. When a main feature is “below”, “below” or “below” a second feature, it can mean that the main feature is directly below or obliquely below the second feature, or simply means that the main feature is lower in level than the second feature. Example

[0041] like Figure 1-Figure 7 As shown, an embodiment of the present application provides an electronic molded case circuit breaker.

[0042] This electronic molded case circuit breaker includes overload protection and instantaneous protection functions, and these two functions can be realized through electronic structures or mechanical structures. The mechanical structure serves as a supplement to the electronic structure, and the supplement here can be understood as when the electronic structure fails, the mechanical structure can provide corresponding protection.

[0043] Here, the electronic structure is mainly realized by the release, the mutual inductor and the control circuit board. The current parameter is monitored by the mutual inductor. When the current parameter meets the protection threshold (such as the short-circuit protection threshold, the overload protection threshold), the control circuit board controls the release to work, and the release drives the traction rod 300 so that the operating mechanism performs the opening operation. The specific electronic structure here is a conventional technical means in this field and will not be repeated here.

[0044] The following is an introduction to the mechanical structure:

[0045] The circuit breaker includes a casing, an operating mechanism and a main circuit conductor.

[0046] The housing here includes a base 100 and a cover body, and the base 100 and the cover body are fastened by bolts.

[0047] The main circuit conductor includes a first wiring board 201, a thermal element 202, a moving contact, a static contact and a second wiring board. Here, the first wiring board 201 and the thermal element 202 are electrically connected by a hard busbar 203. Of course, in addition to this, a soft connection can also be used to achieve electrical connection. The thermal element 202 and the moving contact are electrically connected by a soft connection. Of course, a hard busbar 203 can also be used to achieve electrical connection. The static contact and the second wiring board are an integral part.

[0048] The thermal element 202 includes a fixed section 202a, a connecting section 202b and a wiring section 202c, wherein the wiring section 202c is higher than the fixed section 202a. The connecting section 202b connects the wiring section 202c with the fixed section 202a, so that the thermal element 202 as a whole looks like a Z-shaped structure. Here, the fixed section 202a is used to be fixed to the base 100, for example, by bolts. The wiring section 202c is used to be connected to the first wiring board 201 through the hard busbar 203.

[0049] The circuit breaker here is a three-pole circuit breaker, so the corresponding main circuit conductors are also three. Of course, in addition to this, the circuit breaker can also be a two-pole circuit breaker or a four-pole circuit breaker, and the number of corresponding main circuit conductors will also change.

[0050] The specific principle of the operating mechanism is common knowledge in the art, and its principle will not be introduced here. Only the structure of the traction rod 300 related to the tripping will be introduced.

[0051] Mechanical overload protection and instantaneous protection are realized by backup protectors. The number of backup protectors is the same as the number of poles of the circuit breaker. Each main circuit conductor corresponds to a backup protector.

[0052] Since the structures of the backup protectors of each pole are the same, one pole is introduced here, and the description of the remaining poles refers to that pole.

[0053] The backup protector includes a bimetal strip 400 and an electromagnetic release 500 .

[0054] Here, the bimetallic strip 400 is fixed on the surface of the connecting section 202b close to the fixed section 202a, or on the surface of the connecting section 202b facing the moving contact. The fixing method used here is riveting, and of course, other methods such as plug-in fixing, interference fit, screw fastening, and clamping fixing can also be used for fixing.

[0055] The upper end of the bimetal 400 corresponds to the first drive part 301 of the traction rod 300, that is, when the main circuit is overloaded, the bimetal 400 bends toward the first drive part 301, thereby pushing the first drive part 301 to rotate the traction rod 300, prompting the operating mechanism to perform the opening operation. Of course, the bimetal 400 here can directly push the first drive part 301 by itself, or it can push the first drive part 301 through the fastener on the bimetal 400. In this embodiment, the fastener is used to push (only the mounting hole 401 of the fastener is drawn in the figure, and the fastener is not drawn).

[0056] The electromagnetic release 500 surrounds the wiring section 202c, that is, the electromagnetic release 500 and the bimetallic strip 400 are respectively arranged on two surfaces of the connecting section 202b.

[0057] Here, the electromagnetic release 500 includes an armature 501 , an iron core 502 and a bracket 503 .

[0058] The core 502 includes two second attraction arms 502a and a second connecting arm 502b. The second connecting arm 502b connects the two second attraction arms 502a to form a substantially U-shaped structure. Here, the second connecting arm 502b is fastened to the base 100.

[0059] The bracket 503 is also a roughly U-shaped structure, including a bottom plate 503a, a side plate 503b and a limit plate 503c. The bottom plate 503a is used to fix with the second connecting arm 502b, and is fastened by screws here. Of course, it can also be fixed by riveting. There are two side plates 503b, one end of which is connected to the bottom plate 503a, and the other end extends in the direction of the armature 501, which is used to connect the armature 501 with rotation. Here, the bracket 503 is basically inside the iron core 502 (that is, basically inside the U shape). There are two limit plates 503c on each side plate 503b, and the two limit plates 503c extend to both sides of the second attraction arm 502a. The limit plates 503c here are arranged on both sides of the rotation direction of the first attraction arm 501a. Such a design can prevent the first attraction arm 501a from rotating excessively.

[0060] The armature 501 includes two first attraction arms 501a, a first connecting arm 501b and a first driving arm 501c. The first connecting arm 501b connects the two first attraction arms 501a to form a roughly U-shaped structure. The two first attraction arms 501a are rotatably connected with the two side plates 503b, and the rotatable connection here is realized by a pin shaft, which passes through all the first attraction arms 501a and the side plates 503b to form a rotatable connection. The two first attraction arms 501a correspond to the two second attraction arms 502a respectively, so that when the main circuit conductor is short-circuited, the first attraction arms 501a can move under the action of the second attraction arms 502a. The first driving arm 501c is connected to the first connecting arm 501b, and the other end of the first driving arm 501c extends toward the second driving part 302. When a short circuit occurs in the main circuit conductor, the first attraction arm 501a moves to cause the armature 501 to rotate, prompting the first driving arm 501c to hit the second driving part 302, prompting the operating mechanism to perform a tripping operation.

[0061] Here, since the bending direction of the bimetallic strip 400 is toward the direction of the first connecting arm 501b (that is, it bends when overload protection occurs), and the upper end of the bimetallic strip 400 is higher than the first connecting arm 501b, and the first connecting arm 501b and the bimetallic strip 400 are relatively close, an avoidance groove 501d is set on the first connecting arm 501b, which can effectively reserve space for the bimetallic strip 400, which will be conducive to a more compact design.

[0062] Here, the first driving part 301 and the second driving part 302 are misaligned, so the distance between the bimetal 400 and the first driving part 301 is d, and the distance between the bimetal 400 and the second driving part 302 is D, and D is greater than d. Here, the first driving arm 501c is on one side of the first driving part 301. Moreover, the first driving part 301 and the second driving part 302 are connected by a connecting wall 303, and the connecting wall 303 and the second driving part 302 jointly form a receiving groove 304 (that is, on one side of the first driving part 301), and the first driving arm 501c is located in the receiving groove 304, that is, when the electromagnetic release 500 is not actuated, the first driving arm 501c is in the receiving groove 304.

[0063] With such a structure, when the electromagnetic release 500 is not actuated, the first driving part 301 is located directly above a portion of the first connecting arm 501b, and such a structure will appear more compact.

[0064] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine different embodiments or examples and features of different embodiments or examples described in this specification without contradiction.

[0065] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. An electronic molded case circuit breaker, comprising a housing, an operating mechanism and a main circuit conductor, wherein the operating mechanism comprises a traction rod, and the main circuit conductor comprises a thermal element and a first terminal block; characterized in that: It also includes a backup protector, which includes an electromagnetic release and a bimetallic strip; the thermal element includes a fixed section, a connecting section and a wiring section, and the wiring section is higher than the fixed section; the fixed section is used to be fixed to the housing, the wiring section is used to be electrically connected to the first wiring board, and the connecting section is used to connect the wiring section to the fixed section; the bimetallic strip is fixed on the surface of the connecting section close to the fixed section, and the electromagnetic release is surrounded by the wiring section; the traction rod includes a first driving part and a second driving part, the first driving part is used to cooperate with the bimetallic strip, and the second driving part is used to cooperate with the electromagnetic release.

2. An electronic molded case circuit breaker according to claim 1, characterized in that: The electromagnetic release comprises an armature, an iron core and a bracket; the armature comprises two first attraction arms, a first connecting arm and a first driving arm, and the first connecting arm connects the two first attraction arms; One end of the first driving arm is connected to the first connecting arm, and the other end extends toward the second driving part; the iron core includes two second attraction arms and a second connecting arm, the second connecting arm connects the two second attraction arms, and the second attraction arm corresponds to the first attraction arm; The bracket is fixed to the second connecting arm, and the first attraction arm is rotatably connected to the bracket; The connecting section is located between the two first attraction arms.

3. An electronic molded case circuit breaker according to claim 2, characterized in that: One end of the bimetallic strip is higher than the first connecting arm, the bending direction of the bimetallic strip is toward the direction where the first connecting arm is located, and an avoidance groove for avoiding the bimetallic strip is provided on the first connecting arm.

4. An electronic molded case circuit breaker according to claim 2, characterized in that: The bracket includes a bottom plate, a side plate and a limit plate; the bottom plate is used to be fixed to the second connecting arm; there are two side plates, one end of which is connected to the bottom plate, and the first attraction arm is rotatably connected to the corresponding side plate; two limit plates are connected to each side plate, and the two limit plates are arranged on both sides of the rotation direction of the first attraction arm to prevent the first attraction arm from excessive rotation.

5. The electronic molded case circuit breaker according to claim 1, characterized in that: The distance between the bimetallic strip and the first driving part is d, and the distance between the bimetallic strip and the second driving part is D, and D is greater than d.

6. An electronic molded case circuit breaker according to claim 5, characterized in that: The electromagnetic release comprises a first driving arm corresponding to the second driving part, and the first driving arm is located at one side of the first driving part.

7. An electronic molded case circuit breaker according to claim 6, characterized in that: The first driving part is connected to the second driving part via a connecting wall, and the connecting wall and the second driving part together form a receiving groove, and the first driving arm is located in the receiving groove.

8. An electronic molded case circuit breaker according to claim 6, characterized in that: The electromagnetic release comprises a first connecting arm, and the first driving arm is connected to the first connecting arm; when the electromagnetic release is not actuated, the first driving part is located directly above a portion of the first connecting arm.

9. An electronic molded case circuit breaker according to claim 1, characterized in that: The electronic molded case circuit breaker comprises at least two poles of main circuit conductors, and the number of backup protectors is the same as the number of poles of the main circuit conductors.

10. An electronic molded case circuit breaker according to claim 1, characterized in that: The wiring section and the first wiring board are electrically connected via a soft connection or a hard busbar.

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