A surge protection device

Abstract

A kind of surge protection device, including pressure-sensitive element and the main electrode connected external circuit, pressure-sensitive element has low temperature pole piece, the main electrode is electrically connected swingable tripping pole piece, tripping pole piece one end is equipped with first terminal;It further includes the isolating swing bar of elastic hinged isolating swing bar and the flat surface of tripping pole piece contact, generate the pushing force of pre-separation.When surge continues to occur, low temperature pole piece and tripping pole piece terminal melt and separate, at this time, isolating swing bar and push tripping pole piece swing and separate, contact surface always and the flat surface of tripping pole piece slide contact, and the isolation surface of isolating swing bar will not contact tripping pole piece terminal, so that isolating swing bar will not occur jamming phenomenon.Finally, the isolation surface will be located between tripping pole piece terminal and low temperature pole piece and separate the two, solve the problem of melting and drawing, and will not affect the welding reliability of tripping pole piece terminal and low temperature pole piece under normal state.

Description

Technical Field

[0001] This invention relates to circuit interruption protection devices, specifically a surge protection device. Background Technology

[0002] The general principle of surge protection devices is to utilize the sudden change in resistance of a varistor under overvoltage, causing the surge to conduct to ground and preventing damage to related components in the circuit. However, when the surge persists, the low-temperature solder on the varistor's low-temperature electrode melts due to temperature rise. At this point, an elastic tripping device can disconnect the low-temperature electrode from the main electrode. However, because the melting and disconnection of the solder can easily cause wire-like discharge, arcing can occur between the low-temperature electrode and the main electrode, generating overcurrent. This can ultimately lead to the burnout of the surge protection device and damage to other components in the circuit.

[0003] In the prior art, there are corresponding technical solutions to the aforementioned problem of molten wire drawing. The invention patent publication document with publication number "CN121529431A" entitled "Surge Protector" discloses a surge protector in which, when a surge occurs in the circuit, the solder melts, causing the first break point to open. A slider slides under the action of an elastic element, and a striker pushes the moving contact to separate from the second electrode, thus achieving the second break point opening. This prior art solution uses a double-break point tripping mechanism, which can improve the breaking capacity. However, the scheme of using a slider and striker to push the tripping results in a very complex tripping unit structure, and the break points are not isolated, still posing a risk of wire drawing and arcing.

[0004] For example, the utility model announcement document with publication number "CN203895966U" and title "Inverted-type and Tripping Failure-shielding Power Surge Protector" discloses a surge protection module containing a varistor and a conductive metal spring connected to the varistor via low-temperature solder. A tripping plastic lever, hinged to the surge protection module and located between the varistor and the conductive metal spring, is also provided on one side of the surge protection module. When a surge occurs, the varistor melts and separates from the conductive metal spring. Under the force of a spring, the tripping plastic lever moves towards the varistor. At this time, the upper end of the tripping plastic lever slides away from the varistor within a groove. When it reaches the limit rod, the tripping plastic lever is positioned between the varistor and the conductive metal spring. Because the tripping plastic lever is located between the varistor and the conductive metal spring, the varistor and the conductive metal spring are completely separated, preventing wire adhesion and ensuring safety.

[0005] In the aforementioned prior art, the use of a plastic swing arm to isolate the varistor from the conductive metal spring effectively solves the problem of melting and wire pulling. However, this solution still has significant drawbacks. The varistor and the conductive metal spring are connected using low-temperature solder, and there are often solder joints or interlocking or meshing terminals between them. These solder joints or terminals do not melt, resulting in the solder joints between the varistor and the conductive metal spring not being flat surfaces. The tripping plastic swing arm is located between the varistor and the conductive metal spring. When the tripping plastic swing arm swings, its isolation surface is very likely to touch the non-melting solder joints, causing the swing arm to jam and leading to tripping isolation failure. If the varistor and the conductive metal spring are welded flat, a reliable weld cannot be guaranteed. Attempting to raise the isolation surface of the plastic swing arm to avoid the solder joints during swing will cause the conductive metal spring to rise or have increased curvature, which will further increase the pre-stress between the varistor and the conductive metal spring. In this existing technical solution, due to the use of spring-loaded separation and the isolation lever being located between the varistor and the conductive metal spring, there is a contradiction between swing-out isolation and reliable electrical connection between the varistor and the spring. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a surge protection device, including a varistor and a main electrode connected to an external circuit. The varistor has a low-temperature electrode, and the main electrode is electrically connected to a swingable trip electrode, one end of which has a first terminal. It also includes an elastically hinged isolation lever, which has a protruding isolation surface and a contact surface extending towards the trip electrode. In a first state, the first terminal of the trip electrode and the low-temperature electrode are welded together, and the contact surface of the isolation lever contacts the flat surface of the trip electrode under elastic force. In a second state, the isolation lever swings under elastic force, causing the contact surface to contact the flat surface of the trip electrode, thus separating the first terminal and the low-temperature electrode, and the isolation surface swings between the first terminal and the low-temperature electrode.

[0007] Furthermore, the first terminal is a protruding electrode plate located on one side of the end of the trip electrode plate, and the contact surface of the isolation lever and the flat surface area of ​​the trip electrode plate are located on the side of the first terminal.

[0008] Furthermore, the isolation swing arm is a fan-shaped component, with the contact surface located at the outermost circle of the isolation swing arm, and the isolation surface being an arc-shaped surface protruding along the surface of the isolation swing arm.

[0009] Furthermore, it also includes a housing, on which a first rotating shaft and a second rotating shaft are connected. One end of the tripping electrode is hinged to the first rotating shaft, and the isolation swing rod is hinged to the second rotating shaft. A torsion spring is sleeved on the second rotating shaft.

[0010] Furthermore, a first arc-shaped groove is formed on the housing, and the isolation surface is embedded in and slides in the first arc-shaped groove.

[0011] Furthermore, the pressure-sensitive element is installed in the space on the side of the housing relative to the isolation lever, and the low-temperature electrode extends through the housing and is located on one side of the first arc-shaped groove.

[0012] Furthermore, the first arc-shaped groove is provided with an arc-shaped protrusion one at its starting end, and an arc-shaped protrusion two that engages with the arc-shaped protrusion one is provided on the inner surface of the isolation swing rod.

[0013] Furthermore, a second arc-shaped groove is formed at the top of the housing, and an elastic arm that extends outward and is bent at the end is connected to the outer circle of the isolation swing rod. The elastic arm can be embedded in the second arc-shaped groove and slide.

[0014] Furthermore, when the surge protection device is in the second state, the elastic arm and the rotating shaft are in contact and limited.

[0015] Furthermore, a limiting plate is provided on the upper side of the starting end of the second arc-shaped groove, and the end of the elastic arm can engage with one side of the limiting plate, so that the surge protection device is in the initial state, in which there is a gap between the contact surface of the isolation swing arm and the flat surface of the trip electrode.

[0016] Compared with the prior art, the technical solution of this application has the following beneficial effects: Due to the contact surface of the isolating lever and the flat surface of the trip electrode, a pre-separation thrust is generated. When the surge continues, the low-temperature electrode and the trip electrode terminal melt and separate. At this time, the isolating lever and the trip electrode swinging apart are separated. The contact surface always slides against the flat surface of the trip electrode, and the isolating surface of the isolating lever will not contact the trip electrode terminal throughout the entire process, preventing the isolating lever from jamming. Finally, the isolating surface will be located between the trip electrode terminal and the low-temperature electrode, isolating them, solving the melting and wire-drawing problem, and will not affect the welding reliability of the trip electrode terminal and the low-temperature electrode under normal conditions. Attached Figure Description

[0017] Figure 1 : Schematic diagram of the overall structure of the surge protection device; Figure 2 Schematic diagram of the split structure of a surge protection device Figure 1 ; Figure 3 Schematic diagram of the split structure of a surge protection device Figure 2 ; Figure 4 Schematic diagram of the initial state structure of the surge protection device; Figure 5 Schematic diagram of the surge protection device in its first state; Figure 6 Schematic diagram of the second state structure of the surge protection device; Figure 7 : Figure 6 Sectional view along direction A; Figure 8 : Figure 7 A magnified view of section B. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] A surge protection device includes a varistor 11 and a main electrode 12 connected to an external circuit. The varistor 11 has a low-temperature electrode 111. The main electrode 12 is electrically connected to a swingable trip electrode 13, one end of which has a first terminal 131. It also includes an elastically hinged isolation lever 14, which has a protruding isolation surface 141. The surface of the isolation surface 141 has an abutment surface 142 extending towards the trip electrode 13. The surge protection device has a first terminal 131. In one state, the first terminal 131 of the trip electrode 13 is welded to the low-temperature electrode 111, and the isolation lever 14, driven by elastic force, has its contact surface 142 in contact with the flat surface of the trip electrode 13; the surge protection device has a second state, in which the isolation lever 14 swings under the drive of elastic force, and the contact surface 142 in contact with the flat surface of the trip electrode 13, causing it to swing and separate the first terminal 131 and the low-temperature electrode 111, and the isolation surface 141 swings between the first terminal 131 and the low-temperature electrode 111.

[0020] Specifically, in this embodiment, see Figures 1-3 The varistor 11 is a varistor, and the main electrode 12 is used to connect to the external input circuit. The trip electrode 13 is a hinged component at one end, which can swing around the hinge axis and can be connected to the main electrode 12 using a copper braided strip as an electrical connector. The isolation swing arm 14 is made of insulating material, also hinged at one end, but has an elastic element that can drive its swing. The low-temperature electrode 111 of the varistor 11 and the first terminal 131 of the trip electrode 13 are soldered with low-temperature solder. When this surge protection device is in the first state, Figure 5 As shown. The low-temperature electrode 111 and the first terminal 131 are not molten. At this time, the isolating swing rod 14 abuts against the flat surface of the trip electrode 13 through the contact surface 142, and under the drive of the elastic element, it tends to push the trip electrode 13 to swing. When the surge protection device experiences excessively high temperature due to a continuous surge, the low-temperature electrode 111 and the first terminal 131 melt and separate, as shown. Figure 6As shown. The isolating lever 14 begins to push the trip electrode 13 to swing. Since the contact surface 142 only contacts the flat surface of the trip electrode 13, it will not contact the first terminal 131 during the swing, thus avoiding the problem of the isolating lever 14 getting stuck. After the isolating lever 14 pushes the trip electrode 13 to swing and separate through the contact surface 142, the isolating surface 141 will eventually swing between the first terminal 131 and the low-temperature electrode 111, effectively isolating the two and increasing the electrical clearance to prevent overcurrent and arcing caused by wire pulling after melting. Throughout the process, the contact surface 142 and the isolating surface 142 of the isolating lever 14 will not contact the first terminal 131, and the swing separation is rapid and reliable. Therefore, while solving the problem of molten wire pulling isolation, the reliability of the welding between the low-temperature electrode 111 and the first terminal 131 can also be guaranteed, and a welding method with terminal and groove matching can be adopted.

[0021] In a more preferred embodiment, the first terminal 131 is a raised electrode plate located on one side of the end of the trip electrode plate 13, and the contact surface 142 of the isolation lever 14 and the flat surface area of ​​the trip electrode plate 13 are located on the side of the first terminal 131.

[0022] In this embodiment, the trip electrode 13 is a single-piece component with one end bent to form a protruding electrode, which can be embedded in the groove of the low-temperature electrode 111 to achieve reliable low-temperature soldering. The surface of the trip electrode 13, except for the first terminal 131, is flat, and the contact surface 142 always contacts this flat surface during the swinging process of the trip electrode 13.

[0023] In a more preferred embodiment, the isolation lever 14 is a fan-shaped component, with the contact surface 142 located at the outermost circle of the isolation lever 14, and the isolation surface 141 being an arc-shaped surface protruding along the surface of the isolation lever 14. The fan-shaped isolation lever 14 can have a large isolation and contact area. The contact surface 142 is an arc-shaped rib extending from the outermost circle of the fan-shaped isolation lever 14, and the isolation surface 141 is an arc-shaped isolation surface perpendicular to the contact surface 142. The isolation surface 141 is a certain distance from the outer circle of the contact surface 142. The width of the contact surface 142 is narrower than that of the isolation surface 141, so that it can only contact the flat surface of the trip electrode 13 located on the side of the first terminal 131. The width of the isolation surface 141 needs to ensure that the separated low-temperature electrode 111 is isolated inside the isolation lever 14.

[0024] In a more preferred embodiment, the system further includes a housing 15, on which a first rotating shaft 151 and a second rotating shaft 152 are connected. One end of the tripping electrode 13 is hinged to the first rotating shaft 151, and the isolation swing rod 14 is hinged to the second rotating shaft 152. A torsion spring is sleeved on the second rotating shaft 152. In this embodiment, the housing 15 is made of insulating material and is used to support the aforementioned components such as the isolation swing rod 14.

[0025] In a more preferred embodiment, a first arc-shaped groove 153 is formed on the housing 15, and the isolation surface 141 is embedded in and slides within the first arc-shaped groove 153. See details... Figure 7 and Figure 8 The isolation surface 141 is embedded in the first arc-shaped groove 153, which can limit and guide the isolation lever 14 to a certain extent. Since the bottom end of the isolation surface 141 is embedded in the groove, and since the isolation surface 141 extends from the fan-shaped protrusion of the isolation lever 14, the creepage path between the separated first terminal 131 and the low temperature electrode 111 is completely cut off, thus achieving effective electrical isolation between the two.

[0026] In a more preferred embodiment, the pressure-sensitive element 11 is installed in the space on the side of the housing 15 relative to the isolation lever 14, and the low-temperature electrode 111 extends through the housing 15 and is located on one side of the first arc-shaped groove 153. The housing 15 acts as an insulating component, isolating the pressure-sensitive element 11 and the aforementioned tripping electrode 13 to a certain extent, leaving only the low-temperature electrode 111 as an electrical connection interface extending to one side of the housing 15.

[0027] In a more preferred embodiment, the starting end of the first arc-shaped groove 153 is further provided with an arc-shaped protrusion 154, and an arc-shaped protrusion 2 143 that engages with the arc-shaped protrusion 154 is provided on the inner surface of the isolation swing rod 14. See details below. Figure 2 and Figure 3 After the arc-shaped protrusion 154 and the arc-shaped protrusion 143 engage, the isolating swing arm 14 is limited along its hinge axis, preventing it from wobbling during its swing. This further ensures that its contact surface 142 remains in contact with the flat surface area of ​​the trip electrode 13.

[0028] In a more preferred embodiment, a second arc-shaped groove 155 is provided at the top of the housing 15, and an elastic arm 144 extending outward and bent at the end is connected to the outer circle of the isolation swing rod 14. The elastic arm 144 can be embedded in the second arc-shaped groove 155 and slide.

[0029] In this embodiment, the end of the elastic arm 144 is a reverse-bent, pressable handle 145. Pulling the handle 145 overcomes the elastic force of the torsion spring and retracts the isolation lever 14. The handle 145 extends to the top of the housing 15, and its position reflects the state of the isolation lever 14.

[0030] In a more preferred embodiment, when the surge protection device is in the second state, the elastic arm 144 and the pivot 151 are in contact and limited. After the isolating swing arm 14 swings and contacts the trip plate 13 to swing and separate, it can be limited by the pivot 151.

[0031] In a more preferred embodiment, a limiting plate 156 is provided on the upper side of the starting end of the second arc-shaped groove 155. The end of the elastic arm 144 can engage with one side of the limiting plate 156, so that the surge protection device is in the initial state. In this state, there is a gap between the contact surface 142 of the isolating swing arm 14 and the flat surface of the tripping electrode 13. See details. Figure 4 and Figure 5 In the first state, the contact surface 142 of the isolating lever 14 and the trip plate 13 are in contact with each other. When welding the first terminal 131 and the low-temperature electrode 111, it is undesirable for them to be in contact, as this contact force is detrimental to welding convenience and post-weld reliability. Furthermore, this surge protection device does not need to be in the first state during storage and transportation; it can be ensured to be in the first state during use. Therefore, the isolating lever 144 can be pulled back by the handle 145, causing it to be engaged by the limiting plate 156. At this time, the contact surface 142 and the trip plate 13 separate, losing their contact force, allowing the welding point between the first terminal 131 and the low-temperature electrode 111 to be in a free state. During use, the handle 145 can be pressed to disengage it from the limiting plate 156. At this time, the isolating lever 144, under the action of the torsion spring, will contact the low-temperature electrode 111, putting the surge protector into operation.

[0032] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0033] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A surge protection device, comprising a varistor (11) and a main electrode (12) connected to an external circuit, wherein the varistor (11) has a low-temperature electrode (111), characterized in that, The main electrode (12) is electrically connected to a swingable trip electrode (13), one end of which is provided with a first terminal (131); it also includes an elastically hinged isolation lever (14), which is provided with a protruding isolation surface (141), and the surface of the isolation surface (141) is provided with an abutment surface (142) extending toward the trip electrode (13); the surge protection device has a first state, in which the first terminal (131) of the trip electrode (13) and the low temperature electrode are connected. (111) Welding, the isolation lever (14) is driven by elastic force, the contact surface (142) and the flat surface of the trip electrode (13) come into contact; the surge protection device has a second state, the isolation lever (14) swings under the drive of elastic force, the contact surface (142) comes into contact with the flat surface of the trip electrode (13) causing it to swing so that the first terminal (131) and the low temperature electrode (111) are separated, and the isolation surface (141) swings between the first terminal (131) and the low temperature electrode (111).

2. The surge protection device as described in claim 1, characterized in that, The first terminal (131) is a protruding electrode on one side of the end of the trip electrode (13), and the flat surface area where the contact surface (142) of the isolation lever (14) and the trip electrode (13) contact is located on the side of the first terminal (131).

3. The surge protection device as described in claim 2, characterized in that, The isolation swing rod (14) is a fan-shaped component, the contact surface (142) is located at the outermost circle of the isolation swing rod (14), and the isolation surface (141) is an arc-shaped surface that protrudes along the surface of the isolation swing rod (14).

4. The surge protection device as described in claim 3, characterized in that, It also includes a housing (15), on which a rotating shaft one (151) and a rotating shaft two (152) are connected. One end of the trip electrode (13) is hinged to the rotating shaft one (151), and the isolation swing rod (14) is hinged to the rotating shaft two (152). A torsion spring is sleeved on the rotating shaft two (152).

5. The surge protection device as described in claim 4, characterized in that, The housing (15) has a first arc-shaped groove (153) and the isolation surface (141) is embedded in and slides in the first arc-shaped groove (153).

6. The surge protection device as described in claim 5, characterized in that, The pressure-sensitive element (11) is installed in the space on the side of the housing (15) relative to the isolation swing rod (14), and the low-temperature electrode (111) extends through the housing (15) and is located on one side of the first arc-shaped groove (153).

7. The surge protection device as described in claim 5, characterized in that, The first arc-shaped groove (153) is also provided with an arc-shaped protrusion one (154) at the starting end, and an arc-shaped protrusion two (143) that meshes with the arc-shaped protrusion one (154) is provided on the inner surface of the isolation swing rod (14).

8. The surge protection device as described in claim 5, characterized in that, The top of the housing (15) has a second arc-shaped groove (155), and the outer circle of the isolation swing rod (14) is connected to an outwardly extending and bent elastic arm (144). The elastic arm (144) can be embedded in the second arc-shaped groove (155) and slide.

9. The surge protection device as described in claim 8, characterized in that, When the surge protection device is in the second state, the elastic arm (144) and the rotating shaft (151) are in contact with the limit.

10. The surge protection device as described in claim 8, characterized in that, The upper side of the starting end of the second arc-shaped groove (155) is provided with a limiting plate (156). The end of the elastic arm (144) can engage with one side of the limiting plate (156), so that the surge protection device is in the initial state. In this state, there is a gap between the contact surface (142) of the isolation swing rod (14) and the flat surface of the trip electrode (13).

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