A bimetallic strip thermal protector

Abstract

The application discloses a bimetallic strip thermal protector, and relates to the technical field of circuit protection devices, which comprises a base, wherein the base is provided with a bottom contact plate, and the top surface of the bottom contact plate is provided with fixed contact points; the base is provided with a slot, and the bottom contact plate is provided with a connecting piece one connected with a power supply in the slot; the ground of the base is provided with a connecting plate, the connecting plate is provided with a connecting piece two connected with the power supply, the end of the connecting plate away from the base is bent, the end of the connecting plate away from the base is provided with a top contact strip along the length direction of the connecting plate, and the top contact strip is provided with a movable contact point corresponding to the fixed contact points; the top surface of the connecting plate is provided with an elastic piece, and the end of the elastic piece away from the connecting plate is fixed with the top contact strip; the connecting plate serves as a bimetallic strip assembly, can drive the top contact strip to separate the movable contact point from the fixed contact point to realize protection when overheating, and the addition of the elastic piece can assist the top contact strip to quickly reset when the temperature recovers, thereby shortening the reset time, improving the power supply use efficiency, and meeting the requirement of fast recovery operation of equipment compared with the traditional structure.

Description

Technical Field

[0001] This application relates to the field of circuit protection equipment technology, and in particular to a bimetallic strip thermal protector. Background Technology

[0002] Bimetallic strip thermal protectors are an important thermal protection element with wide applications in many fields. Their core component, the bimetallic strip, is made of two metals with different coefficients of thermal expansion bonded together. When the temperature changes, the bimetallic strip bends and deforms due to the uneven expansion of the two metal layers. This characteristic is used to control the on / off state of the circuit, thus providing overheat protection.

[0003] A bimetallic strip thermal protector typically consists of a bimetallic strip, a contact system, and other components. Under normal operating conditions, the bimetallic strip maintains its original shape, the contacts are closed, and the circuit is functioning correctly. When an abnormality occurs during equipment operation, causing an increase in current or a rise in ambient temperature to a certain level, the bimetallic strip absorbs heat. Due to the difference in thermal expansion coefficients between its constituent metals, the bimetallic strip bends and deforms. As the deformation increases, the bimetallic strip pushes the connected moving contact, separating it from the stationary contact, thereby cutting off the circuit and preventing further current flow, thus providing overheat protection for the equipment. When the temperature decreases, the bimetallic strip gradually returns to its original shape, the contacts close again, and the circuit is reconnected. Regarding the aforementioned technologies, the inventors believe that after the metal sheet springs open, the reset time of the metal sheet is relatively long when the current returns to normal. This means that even after the normal current is restored, the equipment still needs to wait a long time before it can be put back into normal operation. This reduces the efficiency of the power supply to a certain extent and affects the overall working performance and operating efficiency of the equipment. Utility Model Content

[0004] The purpose of this application is to provide a bimetallic strip thermal protector to improve the problem of a long reset time of the bimetallic strip after it has popped open and the current has returned to normal.

[0005] This application provides a bimetallic strip thermal protector, employing the following technical solution: A bimetallic strip thermal protector includes a base, a bottom contact plate with a fixed contact on its top surface, a slot within which a connecting piece for power supply is located on the bottom contact plate, a connecting plate with a power supply is positioned on the base, a connecting plate with a power supply, a second connecting piece for power supply is positioned on the connecting plate, the end of the connecting plate away from the base is bent, a top contact strip is positioned along the length of the connecting plate at the end away from the base, a moving contact is positioned above the bottom contact plate corresponding to the fixed contact, and an elastic element is positioned on the top surface of the connecting plate, the end of the elastic element away from the connecting plate being fixed to the top contact strip.

[0006] By adopting the above technical solution, the connecting plate, as a bimetallic strip assembly, can drive the top contact strip to separate the moving contact from the fixed contact when overheating, thereby achieving protection. The addition of the elastic element can assist the top contact strip to quickly reset when the temperature recovers, shortening the reset time and improving power efficiency. Compared with the traditional structure, it can better meet the needs of equipment to quickly resume operation.

[0007] Optionally, the top contact bar includes at least two sub-contact bars, and the moving contact is located on the sub-contact bars.

[0008] By adopting the above technical solution, the setting of multiple contacts increases the current conduction path, effectively improving the overall conductivity. When a large current passes through, it can reduce the heat generated by the contact resistance of the contacts, reduce the risk of overheating, and at the same time ensure the stability of current transmission, making the protector more reliable in terms of conductivity.

[0009] Optionally, the top surface of the connecting plate is provided with a sliding groove along its length, a slider is slidably engaged in the sliding groove, a slide plate is provided on the slider, the elastic element is located on the slide plate, and a fixing element is provided at the end of the elastic element away from the slide plate; the contact strip is provided with a plurality of slots at intervals along the length of the sliding groove; the fixing element passes through the interval between the contact strips and engages with the slots.

[0010] By adopting the above technical solution, the position of the elastic element is adjusted, thereby controlling its tensile length. In this way, the rebound tension of the elastic element can be flexibly adjusted according to different usage scenarios and protection requirements. When a faster reset speed is required, the elastic element can be adjusted to a suitable position to provide sufficient tension, thereby achieving controllable reset time and enhancing the adaptability of the protector.

[0011] Optionally, the slide plate is in contact with the top surface of the connecting plate.

[0012] By adopting the above technical solution, stable support can be provided for the sliding of the slider in the groove, which can reduce the slider from deviating or shaking.

[0013] Optionally, a guide slope is provided at the opening of the card slot.

[0014] By adopting the above technical solution, when the position of the elastic element is adjusted to allow the fixing element to switch between different slots, the guide slope can reduce the resistance of the fixing element entering the slot, making the operation smoother.

[0015] Optionally, the base is provided with baffles on both sides of the bottom contact plate.

[0016] By adopting the above technical solution, the baffle provides guidance for the insertion and installation of the bottom contact plate, which helps to accurately insert the bottom contact plate into the slot, thus improving the convenience and accuracy of installation.

[0017] Optionally, the baffle is bent to abut against the top surface of the bottom contact plate.

[0018] By adopting the above technical solution, after the bottom contact plate is installed in place, the baffle can fix the bottom contact plate from the top, reducing the loosening or displacement of the bottom contact plate due to vibration, impact and other factors during use, thereby ensuring the reliability of the contact between the fixed contact and the moving contact.

[0019] Optionally, the baffle extends downward and is bent to have a locking plate that engages with the bottom surface of the connecting plate.

[0020] By adopting the above technical solution, the baffle provides stable support and limitation for the connecting plate, which can reduce the shaking of the connecting plate.

[0021] Optionally, the bottom surface of the connecting plate is provided with a fixing groove corresponding to the card plate.

[0022] By adopting the above technical solution, the fixing groove can position and fix the card plate, thereby improving the firmness of the connection between the baffle and the connecting plate.

[0023] In summary, this application includes at least one of the following beneficial technical effects of bimetallic strip thermal protectors: 1. As a bimetallic strip assembly, the connecting plate can drive the top contact strip to separate the moving contact from the fixed contact when overheating, thus achieving protection. The addition of the elastic element can assist the top contact strip to quickly reset when the temperature recovers, shortening the reset time and improving power efficiency. Compared with the traditional structure, it can better meet the needs of equipment to quickly resume operation. 2. The multiple contact points increase the current conduction path, effectively improving the overall conductivity. When a large current passes through, it can reduce the heat generated by the contact resistance, reduce the risk of overheating, and at the same time ensure the stability of current transmission, making the protector more reliable in terms of conductivity. 3. Adjusting the position of the elastic element controls its stretching length. This allows for flexible adjustment of the elastic element's rebound force according to different usage scenarios and protection requirements. When a faster reset speed is needed, the elastic element can be adjusted to a suitable position to provide sufficient tension, achieving controllable reset time and enhancing the adaptability of the protector. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the overall structure of a bimetallic thermal protector; Figure 2 yes Figure 1 Enlarged schematic diagram of the structure at point A; Figure 3 This is a schematic diagram illustrating the fixed groove structure in the embodiment.

[0025] In the diagram, 1 is the base; 11 is the slot; 2 is the bottom contact plate; 21 is the fixed contact point; 22 is the connecting piece one; 3 is the connecting plate; 31 is the connecting piece two; 32 is the sliding groove; 33 is the slider; 34 is the sliding plate; 4 is the top contact bar; 41 is the dividing contact bar; 42 is the moving contact point; 5 is the elastic element; 51 is the fixing element; 6 is the slot; 61 is the guide slope; 7 is the baffle; 71 is the clamping plate; and 8 is the fixing groove. Detailed Implementation

[0026] The following is in conjunction with the appendix Figure 1 -Appendix Figure 3 This application will be described in further detail below.

[0027] A bimetallic strip thermal protector, reference Figure 1 The system includes a base 1, which is made of an insulating and high-temperature resistant material, such as ceramic. The base 1 is L-shaped and has a bottom contact plate 2 that is snapped onto it. The top surface of the bottom contact plate 2 is fixedly provided with a fixed contact point 21 by riveting. The base 1 is integrally formed with a slot 11, and the bottom contact plate 2 is located in the slot 11 and integrally provided with a connecting piece 22 for connecting to the power supply. The connecting piece 22 is made of copper sheet with good conductivity. Reference Figure 3 A connecting plate 3 is fixedly installed on the bottom surface of the base 1 by welding. The connecting plate 3 is made of a metal sheet with a certain degree of elasticity. A connecting piece 31 connected to the power supply is welded and fixed on the connecting plate 3. The connecting piece 31 is also made of copper sheet with good conductivity.

[0028] Reference Figure 1 , Figure 3 The base 1 is fixed with baffles 7 on both sides of the bottom contact plate 2 by bolts. The baffles 7 are made of insulating and high temperature resistant material. The baffles 7 are bent to abut against the top surface of the bottom contact plate 2. The baffles 7 extend downward and are bent to form a locking plate 71 that engages with the bottom surface of the connecting plate 3. The bottom surface of the connecting plate 3 is integrally formed with a fixing groove 8 corresponding to the locking plate 71. The locking plate 71 and the fixing groove 8 are locked together by interference fit. Reference Figure 1 The end of the connecting plate 3 away from the base 1 is set by bending process. The top contact strip 4 is fixedly set along the length direction of the connecting plate 3 by welding. The top contact strip 4 is made of conductive metal material. The top contact strip 4 is located above the bottom contact plate 2 and is fixedly set with a moving contact 42 by riveting corresponding to the fixed contact 21. The top contact strip 4 includes at least two sub-contact strips 41. In this embodiment, two are preferred. The moving contact 42 is located on the sub-contact strips 41. Reference Figure 1 , Figure 3The top surface of the connecting plate 3 is provided with an elastic element 5, which is a spring. The end of the elastic element 5 away from the connecting plate 3 is fixed to the top contact strip 4. Specifically, the top surface of the connecting plate 3 is provided with a sliding groove 32 in an integral molding manner along its length. A slider 33 is slidably engaged in the sliding groove 32. A sliding plate 34 is integrally provided on the slider 33. Both the slider 33 and the sliding plate 34 are made of insulating and high-temperature resistant material. The elastic element 5 is located on the sliding plate 34. One end of the elastic element 5 is welded and fixed to the sliding plate 34. The sliding plate 34 is in contact with the top surface of the connecting plate 3.

[0029] Reference Figure 1 , Figure 2 A fixing member 51 is provided at the end of the elastic member 5 away from the slide plate 34. The fixing member 51 is made of insulating and high temperature resistant material. Several slots 6 are provided at intervals along the length of the slide groove 32. In this embodiment, five slots are preferred. A guide slope 61 is provided at the opening of the slot 6. The fixing member 51 passes through the interval between the slots 41 and engages with the slots 6. The engagement realizes the relative fixation of the elastic member 5 and the top contact bar 4.

[0030] The implementation principle of this application embodiment is as follows: In actual use, connecting piece 1 22 and connecting piece 2 31 are connected to the power circuit to form a path. Current flows from connecting piece 1 22 into the bottom contact plate 2, and is conducted to the top contact plate 4 via the fixed contact 21 and the moving contact 42 on the top contact bar 4. Then, it is transmitted to connecting piece 2 31 through the connecting plate 3 to realize circuit conduction. When the circuit is overloaded or overheated, the connecting plate 3, as the core bimetallic strip assembly, deforms due to the temperature rise, which drives the top contact bar 4 to separate the moving contact 42 from the fixed contact 21, cutting off the circuit. At this time, the elastic element 5 is stretched and stores energy. When the current returns to normal and the temperature drops, the connecting plate 3 returns to its original state, the elastic element 5 releases its elastic force, and pushes the top contact bar 4 to quickly reset through the engagement of the fixing piece 51 and the slot 6, realizing rapid circuit conduction. This solves the problem of long reset time in traditional circuits and improves the response speed and reliability of the protector.

[0031] The embodiments described in this specific implementation are preferred embodiments of this application and are not intended to limit the scope of protection of this application. Identical components are represented by the same reference numerals. Therefore, all equivalent changes made to the structure, shape, and principle of this application should be covered within the scope of protection of this application.

Claims

1. A bimetallic strip thermal protector, comprising a base (1), characterized in that: The base (1) is provided with a bottom contact plate (2), and a fixed contact point (21) is provided on the top surface of the bottom contact plate (2); the base (1) is provided with a slot (11), and a connecting piece (22) connected to the power supply is provided in the slot (11) of the bottom contact plate (2); a connecting plate (3) is provided on the ground of the base (1), and a connecting piece (31) connected to the power supply is provided on the connecting plate (3). The end of the connecting plate (3) away from the base (1) is bent. A top contact strip (4) is provided along the length of the connecting plate (3) at the end away from the base (1). A moving contact point (42) is provided on the top contact strip (4) above the bottom contact plate (2) corresponding to the fixed contact point (21); an elastic element (5) is provided on the top surface of the connecting plate (3), and the end of the elastic element (5) away from the connecting plate (3) is fixed to the top contact strip (4).

2. The bimetallic strip thermal protector according to claim 1, characterized in that: The top contact bar (4) includes at least two sub-contact bars (41), and the moving contact (42) is located on the sub-contact bars (41).

3. A bimetallic strip thermal protector according to claim 2, characterized in that: The top surface of the connecting plate (3) is provided with a sliding groove (32) along its length direction. A slider (33) is slidably engaged in the sliding groove (32). A slide plate (34) is provided on the slider (33). An elastic element (5) is located on the slide plate (34). A fixing element (51) is provided at the end of the elastic element (5) away from the slide plate (34). The contact strip (41) is provided with a plurality of slots (6) at intervals along the length direction of the sliding groove (32). The fixing element (51) passes through the interval between the contact strips (41) and engages with the slots (6).

4. A bimetallic strip thermal protector according to claim 3, characterized in that: The sliding plate (34) is in contact with the top surface of the connecting plate (3).

5. A bimetallic strip thermal protector according to claim 3, characterized in that: A guide slope (61) is provided at the opening of the slot (6).

6. A bimetallic strip thermal protector according to claim 1, characterized in that: The base (1) is provided with baffles (7) on both sides of the bottom contact plate (2).

7. A bimetallic strip thermal protector according to claim 6, characterized in that: The baffle (7) is bent and abuts against the top surface of the bottom contact plate (2).

8. A bimetallic strip thermal protector according to claim 7, characterized in that: The baffle (7) extends downward and is bent to be provided with a locking plate (71) that engages with the bottom surface of the connecting plate (3).

9. A bimetallic strip thermal protector according to claim 8, characterized in that: The bottom surface of the connecting plate (3) is provided with a fixing groove (8) corresponding to the card plate (71).

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