Thermal tripping structure and circuit breaker
By designing a thermal tripping structure in the circuit breaker, and using the compensation bending mechanism of the tripping bimetal plate and the thermocompensated bimetal plate, the problem of malfunctioning of traditional circuit breakers during ambient temperature changes is solved, and the accurate overload protection of the circuit breaker is achieved.
Patent Information
- Application Number
- CN202411840864.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-13
- Publication Date
- 2025-03-28
AI Technical Summary
Traditional thermal magnetic circuit breakers are prone to malfunction when ambient temperature changes, and cannot accurately realize the overload protection function.
A thermal tripping structure is designed, including tripping bimetallic sheets, warm-added bimetallic sheets, pull rods and heating elements. The tripping bimetal plate is connected to the heating element. When the ambient temperature is high, the tripping bimetal plate is bent, and the temperature-compensating bimetal plate compensates for its bending, so that the traction rod is not affected by erroneous action.
The thermal tripping characteristics of the circuit breaker are achieved without being affected by the ambient temperature, avoiding malfunctions, and ensuring the accuracy of overload protection.
Smart Images
Figure CN119725043A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of low-voltage electrical appliances, and in particular to a thermal trip structure and a circuit breaker. Background Art
[0002] A circuit breaker is a switching device that can connect, carry and disconnect current under normal circuit conditions and can connect, carry and disconnect current under abnormal circuit conditions within a specified time. Traditional thermal magnetic circuit breakers have overload and short circuit protection functions, which can protect lines and power equipment from damage. The overload protection function of thermal magnetic circuit breakers is realized by bimetallic strips. When the circuit is overloaded, the bimetallic strips are heated and bend forward, pushing the traction rod of the circuit breaker to unlock the operating mechanism and disconnect the circuit. Because the bimetallic strip itself will bend and deform due to temperature changes, if the ambient temperature changes greatly, the thermal magnetic circuit breaker will malfunction and fail to accurately realize the overload protection function under temperature changes. Summary of the invention
[0003] In order to solve the above problems, an object of the present invention is to provide a thermal trip structure and a circuit breaker that can make the thermal trip characteristics of the circuit breaker not be affected by the ambient temperature.
[0004] The purpose of the present invention is achieved through the following technical solutions: A thermal trip structure comprises a trip bimetallic strip that can be bent by heat, a traction rod and a heating element, wherein the trip bimetallic strip is connected to the heating element, and the traction rod is rotatably arranged on one side of the trip bimetallic strip; the structure also comprises a temperature compensation bimetallic strip that can be bent by heat, wherein the temperature compensation bimetallic strip is installed on the traction rod and corresponds to the position of the trip bimetallic strip; when the heating element is heated, the trip bimetallic strip is heated, bent toward the temperature compensation bimetallic strip, touches the temperature compensation bimetallic strip and pushes the traction rod to rotate.
[0005] A flange is provided at the lower end of the traction rod, and an avoidance groove is provided at the upper end to avoid bending of the temperature compensation bimetallic strip; the above-mentioned is a stepped long strip plate, the lower end of which is fixed on the flange, and the upper end is a cantilever structure and is located in the avoidance groove.
[0006] The tripping bimetallic strip is provided with an adjusting screw pointing to the temperature compensating bimetallic strip; when the heating element is heated, the adjusting screw can touch the temperature compensating bimetallic strip driven by the tripping bimetallic strip and push the traction rod to rotate.
[0007] The present invention also provides a circuit breaker, which includes a circuit breaker housing and a tripping mechanism installed in the circuit breaker housing for disconnecting the circuit. The circuit breaker housing is also provided with the above-mentioned thermal tripping structure. The traction rod is rotatably installed in the circuit breaker housing and is linked with the tripping mechanism. The traction rod can rotate under the push of the tripping bimetallic strip and push the tripping mechanism to trip and unlock, thereby disconnecting the circuit.
[0008] Two sets of thermal release structures are installed side by side in the circuit breaker housing.
[0009] The structure of the present invention is scientific and reasonable. When the ambient temperature is high, the tripping bimetallic strip will deform and bend at a certain angle. At the same time, the temperature compensation bimetallic strip will also bend in the same direction at the same angle to compensate for the bending of the tripping bimetallic strip, so that the thermal tripping characteristics of the circuit breaker are not affected by the ambient temperature. BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The structure of the present invention is further described in detail below in conjunction with the accompanying drawings.
[0011] Figure 1 It is a schematic structural diagram of the circuit breaker of the present invention.
[0012] Figure 2 It is a structural schematic diagram of the thermal trip structure of the present invention.
[0013] Figure 3 This is a schematic diagram of installing the temperature compensation bimetallic strip on the traction rod according to the present invention.
[0014] Figure 4 It is a schematic structural diagram of the traction rod of the present invention.
[0015] As shown in the figure: 1-tripping bimetallic strip, 2-circuit breaker housing, 3-temperature compensation bimetallic strip, 4-traction rod, 41-flange, 42-avoidance groove, 5-tripping mechanism, 6-heating element, 7-adjusting screw, 8-mounting bracket. DETAILED DESCRIPTION
[0016] The following is an explanation of the implementation of the present invention by specific specific embodiments. People familiar with the technology can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0017] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. It should be noted that the terms "include", "comprise" or any other variants are intended to cover non-exclusive inclusion, so that a process, method, article or device that includes a series of elements includes not only those elements, but also includes other elements that are not explicitly listed, or also includes elements inherent to such process, method, article or device. Example 1
[0018] like Figure 1-4 As shown, this embodiment provides a circuit breaker, which is a thermal magnetic circuit breaker. In addition to the circuit breaker housing 2 and the tripping mechanism 5 installed in the circuit breaker housing 2 for breaking the circuit, the circuit breaker also includes two groups of thermal tripping structures installed side by side in the circuit breaker housing 2. Each group of thermal tripping structures includes a tripping bimetallic strip 1, a temperature-compensating bimetallic strip 3, a traction rod 4, a heating element 6 and an adjusting screw 7. The tripping bimetallic strip 1 and the temperature-compensating bimetallic strip 3 are both plates composed of two layers of metal materials, an iron sheet layer and a copper sheet layer, and will bend toward the side of the iron sheet layer when heated. The iron sheet layers of the tripping bimetallic strip 1 and the temperature-compensating bimetallic strip 3 are both toward the side where the traction rod 4 is located, that is, they will bend toward the same side (the side where the traction rod 4 is located) after being heated.
[0019] The trip bimetallic strip 1 is vertically arranged, and the lower end of the trip bimetallic strip 1 is fixedly installed in the circuit breaker housing 2 .
[0020] The traction rod 4 is horizontally arranged and rotatably installed between the tripping mechanism 5 and the tripping bimetallic strip 1. At the same time, the traction rod 4 is also linked with the tripping mechanism 5, and can push the tripping mechanism 5 to trip and unlock the operating mechanism of the circuit breaker by counterclockwise rotation to disconnect the circuit.
[0021] The heating element 6 is a metal heat-conducting plate fixed in the circuit breaker housing 2. One end of the heating element 6 is connected to the lower end of the trip bimetal 1 as a whole, and the other end is connected to a wire or a metal conductive sheet and fixed and pressed in the circuit breaker housing 2. In order to improve the heat conduction speed, the heating element 6 and the trip bimetal 1 are fixed as a whole by a wide panel-to-wide panel connection method, that is, the lower end of the trip bimetal 1 and the end of the heating element 6 are both wide panel structures, parallel to each other and fitted together.
[0022] The temperature compensating bimetallic strip 3 is a stepped long strip plate, the lower end 31 of the temperature compensating bimetallic strip 3 is fixed on the traction rod 4, and the upper end 32 of the temperature compensating bimetallic strip 3 is a cantilever structure and corresponds to the upper end position of the tripping bimetallic strip 1.
[0023] The adjusting screw 7 is threadedly connected in a screw hole preset at the upper end of the tripping bimetallic strip 1, and the rod of the adjusting screw 7 penetrates the upper end of the tripping bimetallic strip 1 and points to the upper end 32 of the temperature compensating bimetallic strip 3. When the tripping bimetallic strip 1 is bent by heat, the adjusting screw 7 can move toward the temperature compensating bimetallic strip 3 along with the tripping bimetallic strip 1. By adjusting the rod of the adjusting screw 7, the temperature compensating bimetallic strip 3 and the traction rod 4 can be driven to rotate. How it works
[0024] When the ambient temperature is high, the trip bimetal 1 will deform and bend at a certain angle. At the same time, the cantilever structure 32 at the upper end of the temperature compensation bimetal 3 will also bend in the same direction and at the same angle to compensate for the bending of the trip bimetal 1, so that the traction rod 4 will not be pushed by the trip bimetal 1, avoiding the occurrence of false tripping, and making the thermal tripping characteristics of the circuit breaker unaffected by the ambient temperature.
[0025] When the circuit breaker is overloaded, the temperature of the heating element 6 rises, and the temperature of the trip bimetallic strip 1 fixed thereto also rises accordingly. The trip bimetallic strip 1 is driven to bend toward the traction rod 4 after being heated. When the adjusting screw 7 hits the upper end 32 of the temperature compensation bimetallic strip 3, the temperature compensation bimetallic strip 3 is pushed to rotate toward the trip mechanism 5 and the traction rod 4 is simultaneously driven to rotate counterclockwise (towards the trip mechanism 5), so that the trip mechanism 5 is tripped to unlock the operating mechanism of the circuit breaker, and the circuit breaker is tripped to interrupt the overload current. Example 2
[0026] To further optimize the structure, this embodiment adds the following settings based on Embodiment 1.
[0027] like Figure 4 As shown, a flange 41 is provided at the lower end of the traction rod 4, and an avoidance groove 42 is provided at the upper end to avoid the bending of the temperature compensating bimetallic strip 3; the lower end 31 of the temperature compensating bimetallic strip 3 is fixed to the flange 41 by riveting, welding or embedding, and the upper end of the temperature compensating bimetallic strip 3 is located in the avoidance groove 42. Example 3
[0028] The difference between this embodiment and embodiment 1 or 2 is that.
[0029] The thermal trip structure further comprises a mounting bracket 8 , which is fixedly mounted in the circuit breaker housing 2 ; the lower end of the trip bimetallic strip 1 is fixed on the mounting bracket 8 .
[0030] Other aspects of the present invention that are not described in detail are all conventional techniques known to those skilled in the art.
[0031] It should be noted that the terms "comprises", "includes" or any other variations are intended to cover non-exclusive inclusion, so that a process, method, article or apparatus that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or apparatus.
[0032] The protection scope of the present invention is not limited to the technical solutions disclosed in the specific implementation methods. Any modifications, equivalent replacements, improvements, etc. made to the above embodiments based on the technical essence of the present invention shall fall within the protection scope of the present invention.
Claims
1. A thermal trip structure, comprising a trip bimetallic strip (1) that can be bent by heat, a traction rod (4) and a heating element (6), wherein the trip bimetallic strip (1) is connected to the heating element (6), and the traction rod (4) is rotatably arranged on one side of the trip bimetallic strip (1); characterized in that: It also comprises a temperature compensating bimetallic strip (3) that can be bent by heat, wherein the temperature compensating bimetallic strip (3) is mounted on the traction rod (4) and corresponds to the position of the tripping bimetallic strip (1); when the heating element (6) is heated, the tripping bimetallic strip (1) is heated and bends towards the temperature compensating bimetallic strip (3), contacts the temperature compensating bimetallic strip (3) and pushes the traction rod (4) to rotate.
2. The thermal release structure according to claim 1, characterized in that: The heating element (6) is integrally connected to the lower end of the tripping bimetallic strip (1); the upper end of the tripping bimetallic strip (1) corresponds to the upper end of the temperature compensation bimetallic strip (3).
3. The thermal release structure according to claim 1, characterized in that: A flange (41) is provided at the lower end of the traction rod (4), and an avoidance groove (42) is provided at the upper end to avoid bending of the temperature compensation bimetallic strip (3); the temperature compensation bimetallic strip (3) is a stepped long strip plate, the lower end of which is fixed on the flange (41), and the upper end is a cantilever structure and is located in the avoidance groove (42).
4. The thermal release structure according to claim 3, characterized in that: The lower end of the temperature compensation bimetallic strip (3) is fixed to the flange (41) by riveting, welding or embedding.
5. The thermal release structure according to claim 1, characterized in that: The trip bimetallic strip (1) and the temperature compensation bimetallic strip (3) are both plates composed of two layers of metals made of different materials and will bend when heated.
6. The thermal release structure according to claim 5, characterized in that: The tripping bimetallic strip (1) and the temperature compensating bimetallic strip (3) are both plates composed of an iron sheet layer and a copper sheet layer, and will bend towards the iron sheet layer when heated. The iron sheet layers of the tripping bimetallic strip (1) and the temperature compensating bimetallic strip (3) are both oriented towards the side where the traction rod (4) is located.
7. The thermal release structure according to claim 1, characterized in that: The tripping bimetallic strip (1) is provided with an adjusting screw (7) pointing toward the temperature compensating bimetallic strip (3); when the heating element (6) is heated, the adjusting screw (7) can touch the temperature compensating bimetallic strip (3) and push the traction rod (4) to rotate under the drive of the tripping bimetallic strip (1).
8. A circuit breaker, comprising a circuit breaker housing (2) and a tripping mechanism (5) installed in the circuit breaker housing (2) for disconnecting a circuit, characterized in that: The circuit breaker housing (2) is also provided with a thermal trip structure as claimed in any one of claims 1 to 7, wherein the traction rod (4) is rotatably mounted in the circuit breaker housing (2) and is linked to the trip mechanism (5), and the traction rod (4) can be rotated under the push of the trip bimetallic strip (1) and push the trip mechanism (5) to trip and unlock, thereby disconnecting the circuit.
9. The circuit breaker according to claim 8, characterized in that: Two sets of thermal release structures are installed side by side in the circuit breaker housing (2).
10. The circuit breaker according to claim 8, characterized in that: The thermal trip structure also includes a mounting bracket (8), wherein the mounting bracket (8) is fixedly mounted in the circuit breaker housing (2); the lower end of the trip bimetallic strip (1) is fixed on the mounting bracket (8).