Thermomagnetic tripping mechanism and circuit breaker

Abstract

The utility model belongs to the technical field of low-voltage electric appliances, and discloses a thermomagnetic tripping mechanism and a circuit breaker. The mechanism comprises a static contact, a coil, a wiring terminal, a conductor and a bimetallic element. One end of the coil is electrically connected with the static contact; one end of the wiring terminal is electrically connected with an external circuit; one end of the conductor is electrically connected with the other end of the wiring terminal; the bimetallic element comprises two terminals, and the two terminals are electrically connected with the other end of the conductor and the other end of the coil respectively. According to the utility model, the heating value of the thermomagnetic tripping mechanism can be prevented from being increased due to the introduction of the magnet yoke, so that the temperature rise parameter of the circuit breaker is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of low-voltage electrical appliances, in particular to a thermal magnetic tripping mechanism and a circuit breaker. Background Art

[0002] A circuit breaker is a switching device that can close, carry and interrupt current under normal circuit conditions and can close, carry and interrupt current under abnormal circuit conditions within a specified time.

[0003] The circuit breaker is connected in the circuit and is usually used to carry the current of the line. It will only be disconnected when abnormal current appears in the circuit to protect the line and electrical equipment. The circuit breaker carries the current in a continuous and uninterrupted process. In this process, the parts inside the circuit breaker connected to the line will be energized and heat up. Therefore, the temperature rise parameters of the circuit breaker need to be guaranteed to be within the design range to further ensure the reliable operation of the circuit breaker in long-term work.

[0004] Among them, the thermal magnetic tripping mechanism of the circuit breaker has a great influence on the temperature rise parameters. The thermal magnetic tripping mechanism of the current circuit breaker is connected with the terminal, soft connection wire, bimetallic element, yoke, coil, contact, and terminal in sequence. Among them, the traditional yoke is mostly made of copper-clad steel plate, and the copper content is only a few microns on the metal surface, which affects the current carrying capacity, generates serious heat, and affects the temperature rise parameters of the circuit breaker. Utility Model Content

[0005] The utility model aims to provide a thermal magnetic tripping mechanism and a circuit breaker, which are used to prevent the thermal magnetic tripping mechanism from increasing heat due to the introduction of a magnetic yoke, thereby affecting the temperature rise parameters of the circuit breaker.

[0006] To achieve this purpose, the utility model adopts the following technical solutions:

[0007] Thermal magnetic trip mechanism, including

[0008] Stationary contact;

[0009] A coil, one end of which is electrically connected to the stationary contact;

[0010] A wiring terminal, one end of which is used to be electrically connected to an external circuit;

[0011] A conductor, one end of which is electrically connected to the other end of the terminal;

[0012] A bimetallic element comprises two wiring terminals, wherein the two wiring terminals are electrically connected to the other end of the conductor and the other end of the coil respectively.

[0013] As an optional solution of the thermal-magnetic tripping mechanism, the conductor is a soft wire, and the soft wire is welded to the wiring terminal and the bimetallic element respectively.

[0014] As an optional solution of a thermal-magnetic tripping mechanism, the terminal block includes a first terminal block and a second terminal block connected to the first terminal block, the first terminal block and the second terminal block are an integrated structure, the first terminal block is used to be electrically connected to the external circuit, and the surface of the second terminal block is welded to the soft wire.

[0015] As an optional solution of the thermal-magnetic tripping mechanism, the first terminal block and the second terminal block are arranged at an angle.

[0016] As an optional solution of the thermal-magnetic tripping mechanism, a plurality of strip-shaped protrusions or grooves are arranged in parallel on the first wiring board.

[0017] As an optional solution of a thermal-magnetic tripping mechanism, the bimetallic element includes a deformation portion and a welding portion connected to the deformation portion, two wiring terminals are spaced apart on one side surface of the welding portion, and the deformation portion is used to trigger the action of the tripping member of the circuit breaker.

[0018] As an optional solution of the thermal-magnetic tripping mechanism, the deformation portion and the welding portion are arranged at an angle, and the deformation portion and the welding portion are an integrated structure, and a transition fillet is provided at the connection portion between the deformation portion and the welding portion.

[0019] As an optional solution of the thermal-magnetic tripping mechanism, the thermal-magnetic tripping mechanism further includes a yoke, and the yoke is welded to a surface of the welding portion away from the wiring terminal.

[0020] As an optional solution of a thermal-magnetic tripping mechanism, the thermal-magnetic tripping mechanism further includes a bracket located above the magnetic yoke and a moving iron core slidably connected to the bracket, the coil is wound on the moving iron core, and the bracket is U-shaped.

[0021] A circuit breaker comprises the thermal-magnetic tripping mechanism described in any of the above schemes.

[0022] Beneficial effects:

[0023] In the first aspect of the utility model, the circuit parts of the thermomagnetic tripping mechanism, such as the static contact, conductor, coil, terminal block and bimetallic element, all have excellent conductivity. By electrically connecting the two terminals of the bimetallic element to the conductor and the coil respectively, the yoke is excluded from the current circuit of the mechanism, which can avoid the increase in heat generation caused by the introduction of the yoke and effectively improve the temperature rise parameters of the circuit breaker.

[0024] In the first aspect of the present utility model, the circuit breaker equipped with the above thermal-magnetic tripping mechanism has its temperature rise parameter effectively improved, and at the same time can enhance the adaptability of the thermal-magnetic circuit breaker. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a structural schematic diagram of a thermal-magnetic tripping mechanism provided in an embodiment of the utility model.

[0026] In the figure:

[0027] 1. Static contact; 2. Coil; 3. Terminal; 31. First terminal block; 32. Second terminal block; 4. Conductor; 5. Bimetallic element; 51. Deformation portion; 52. Welding portion; 53. Transition fillet; 6. Yoke; 7. Bracket; 8. Moving iron core. DETAILED DESCRIPTION

[0028] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only the parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0029] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" 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 the present invention can be understood according to specific circumstances.

[0030] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0031] In the description of this embodiment, the terms "upper", "lower", "right", etc., are based on the directions or positions shown in the drawings, and are only for the convenience of description and simplified operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0032] Please refer to the attached Figure 1 The first aspect of the present embodiment relates to a thermal magnetic tripping mechanism (hereinafter referred to as the "mechanism"), which includes a stationary contact 1, a coil 2, a terminal 3, a conductor 4 and a bimetallic element 5. One end of the coil 2 is electrically connected to the stationary contact 1; one end of the terminal 3 is used to be electrically connected to an external circuit; one end of the conductor 4 is electrically connected to the other end of the terminal 3; the bimetallic element 5 includes two terminals, which are electrically connected to the other end of the conductor 4 and the other end of the coil 2 respectively.

[0033] In this embodiment, the static contact 1 is used as a conductive part, and both the base material and the coating material have excellent conductivity. At the same time, in order to ensure the reliability of the electrical connection after contact, it is also necessary to maintain a certain contact pressure on the contact surface with the moving contact when the action mechanism is locked; the base material of the conductor 4 and the coil 2 is also copper with excellent conductivity. In addition to ensuring the stability of the wiring, the terminal 3 also has excellent conductivity. The bimetallic element 5 is the main functional part in the thermal or thermal-magnetic tripping structure and must be preferentially set in the circuit of the circuit breaker. In the mechanism, the yoke 6 is also electrically connected to the circuit. Since the yoke 6 is mainly used to reasonably plan the magnetic flux lines, and the yoke 6 is usually a copper-clad steel plate, compared with the bimetallic element 5, the copper content is lower, which greatly limits the conductivity of the thermal-magnetic tripping mechanism. The introduction of the yoke 6 leads to an increase in heat generation, which is not conducive to improving the temperature rise parameters of the circuit breaker. In this embodiment, the two terminals of the bimetallic element 5 are electrically connected to the conductor 4 and the coil 2 respectively, and the yoke 6 is excluded from the current loop of the mechanism. This can avoid the increase in heat generation caused by the introduction of the yoke 6, and at the same time effectively improve the temperature rise parameters of the circuit breaker and enhance the adaptability of the thermal-magnetic circuit breaker.

[0034] For example, the copper content of the middle layer of the 0.8mm bimetallic element 5 is 35%, and the copper layer is about 0.28mm thick, which is 3.5 times thicker than the 0.08mm copper layer on the surface of the copper-clad steel plate of the yoke 6. By excluding the yoke 6 from the circuit, the conductivity is significantly improved.

[0035] Optionally, the conductor 4 is a soft wire, which is welded to the wiring terminal 3 and the bimetallic element 5 respectively.

[0036] In this embodiment, the conductor 4 is a soft wire, which has strong flexibility and can adapt to the positions of the connecting terminals 3 at both ends of the soft wire and the bimetallic element 5, and is convenient for welding.

[0037] Optionally, the terminal block 3 includes a first terminal block 31 and a second terminal block 32 connected to the first terminal block 31, the first terminal block 31 and the second terminal block 32 are an integrated structure, the first terminal block 31 is used to electrically connect to an external circuit, and the surface of the second terminal block 32 is welded to the soft wire.

[0038] In this embodiment, the first terminal block 31 and the first terminal block 31 are integrally formed by stamping and bending. The first terminal block 31 has a welding area on its surface, which is convenient for direct welding of wires of an external circuit or plugging and matching with connectors of an external circuit. The second terminal block 32 also has a welding area on its surface, and the connector of a soft wire can be directly welded to the welding area.

[0039] Optionally, the first wiring board 31 and the second wiring board 32 are arranged at an angle.

[0040] In this embodiment, the bent first terminal block 31 and the second terminal block 32 are at right angles. The angle between the first terminal block 31 and the second terminal block 32 is mainly to adapt to the limiting structure inside the housing of the circuit breaker. Usually, a plurality of embedded limiting grooves are injection molded inside the housing. The first terminal block 31 and the second terminal block 32 are adaptively embedded in the corresponding limiting grooves, which is beneficial to the assembly and limiting of the terminal block 3.

[0041] Optionally, a plurality of strip-shaped protrusions or grooves are arranged in parallel on the first wiring board 31 .

[0042] By providing a plurality of strip-shaped protrusions or grooves in the welding area of ​​the first wiring board 31, the contact area can be increased, thereby improving the stability and reliability of the electrical connection.

[0043] Optionally, the bimetallic element 5 includes a deformation portion 51 and a welding portion 52 connected to the deformation portion 51 , two wiring terminals are spaced apart on one side surface of the welding portion 52 , and the deformation portion 51 is used to trigger the action of a tripping member of the circuit breaker.

[0044] In different types of circuit breakers, the bimetallic element 5 usually has different shapes, and the specific shape is usually determined according to design requirements. In this embodiment, two wiring terminals are provided on one side surface of the welding portion 52, and the two wiring terminals are electrically connected to the other end of the conductor 4 and the other end of the coil 2 respectively. The deformation portion 51 generates a certain bending deformation due to heat accumulation, thereby triggering the action of the tripping member.

[0045] Furthermore, the deformation portion 51 and the welding portion 52 are arranged at an angle, and the deformation portion 51 and the welding portion 52 are an integrated structure, and a transition fillet 53 is provided at a connection position between the deformation portion 51 and the welding portion 52 .

[0046] In this embodiment, the bimetallic element 5 is a stamped integral part, the angle between the deformation portion 51 and the welding portion 52 is a right angle, and a transition fillet 53 is processed at the connection position between the deformation portion 51 and the welding portion 52 by a stamping die to prevent stress concentration.

[0047] Optionally, the thermal-magnetic tripping mechanism further includes a yoke 6 , and the yoke 6 is welded to a surface of the welding portion 52 away from the terminal.

[0048] By connecting the yoke 6 to the bottom of the welding part 52, direct contact between the yoke 6 and the conductor 4 and the coil 2 can be avoided, so that the current yoke 6 is excluded from the circuit. At the same time, the yoke 6 is welded to the welding part 52 away from the surface of the terminal, which can also facilitate the positioning and assembly of the yoke 6.

[0049] Optionally, the thermal-magnetic tripping mechanism further includes a bracket 7 located above the yoke 6 and a moving iron core 8 slidably connected to the bracket 7 , the coil 2 is wound on the moving iron core 8 , and the bracket 7 is U-shaped.

[0050] In this embodiment, the bracket 7 is U-shaped, and the moving iron core 8 is rotatably connected to the mounting hole of the bracket 7. At the same time, the coil 2 is wound around the moving iron core 8. When the current of the coil 2 changes, an electromagnetic field is generated, and the electromagnetic field drives the moving iron core 8 to extend relative to the bracket 7, thereby triggering the circuit breaker to trip. Of course, in this embodiment, the bimetallic element 5 can also be used. When the overload current reaches a certain limit, the deformation of the bimetallic element 5 triggers the circuit breaker to trip.

[0051] The second aspect of this embodiment relates to a circuit breaker, which includes the above-mentioned thermal-magnetic tripping mechanism and has two tripping modes: magnetic instant tripping and thermal delayed tripping. The circuit breaker equipped with the above-mentioned thermal-magnetic tripping mechanism has its temperature rise parameter effectively improved, and can also enhance the adaptability of the thermal-magnetic circuit breaker.

[0052] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention, and are not intended to limit the implementation methods of the present invention. For those skilled in the art, various obvious changes, readjustments and substitutions can be made without departing from the scope of protection of the present invention. It is not necessary and impossible to list all implementation methods here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention shall be included in the scope of protection of the claims of the present invention.

Claims

1. Thermal magnetic tripping mechanism, characterized in that: include Stationary contact (1); A coil (2), one end of the coil (2) being electrically connected to the stationary contact (1); A wiring terminal (3), one end of which is used for electrically connecting to an external circuit; A conductor (4), one end of the conductor (4) being electrically connected to the other end of the connection terminal (3); A bimetallic element (5), the bimetallic element (5) comprising two wiring terminals, the two wiring terminals being electrically connected to the other end of the conductor (4) and the other end of the coil (2) respectively.

2. The thermal magnetic tripping mechanism according to claim 1, characterized in that: The conductor (4) is a soft wire, and the soft wire is welded to the wiring terminal (3) and the bimetallic element (5) respectively.

3. The thermal magnetic tripping mechanism according to claim 2, characterized in that: The wiring terminal (3) comprises a first wiring board (31) and a second wiring board (32) connected to the first wiring board (31); the first wiring board (31) and the second wiring board (32) are an integrated structure; the first wiring board (31) is used for electrically connecting to the external circuit; and the surface of the second wiring board (32) is welded to the soft wire.

4. The thermal magnetic tripping mechanism according to claim 3, characterized in that: The first wiring board (31) and the second wiring board (32) are arranged at an angle.

5. The thermal magnetic tripping mechanism according to claim 3, characterized in that: The first wiring board (31) is provided with a plurality of strip-shaped protrusions or grooves in parallel.

6. The thermal magnetic tripping mechanism according to claim 1, characterized in that: The bimetallic element (5) comprises a deformation portion (51) and a welding portion (52) connected to the deformation portion (51), two wiring terminals are spaced apart on a surface of one side of the welding portion (52), and the deformation portion (51) is used to trigger the action of a tripping member of a circuit breaker.

7. The thermal magnetic tripping mechanism according to claim 6, characterized in that: The deformation portion (51) and the welding portion (52) are arranged at an angle, and the deformation portion (51) and the welding portion (52) are an integrated structure, and a transition fillet (53) is provided at the connection portion between the deformation portion (51) and the welding portion (52).

8. The thermal magnetic tripping mechanism according to claim 6, characterized in that: The thermal magnetic tripping mechanism also includes a yoke (6), and the yoke (6) is welded to a surface of the welding portion (52) away from the wiring terminal.

9. The thermal magnetic tripping mechanism according to claim 8, characterized in that: The thermal magnetic tripping mechanism also includes a bracket (7) located above the magnetic yoke (6) and a moving iron core (8) slidably connected to the bracket (7), the coil (2) is wound on the moving iron core (8), and the bracket (7) is U-shaped.

10. A circuit breaker, characterized in that It comprises a thermal-magnetic tripping mechanism as described in any one of claims 1 to 9.

Images