A backup surge protector with short circuit protection and thermal protection

Abstract

The utility model relates to the field of lightning protection equipment, concretely relates to a backup surge protection device with short circuit protection and thermal protection, including casing and upper cover, the casing is with upper cover constitutes installation cavity, is provided with static contact, wiring seat, rotatable handle, rotatable jump buckle, connecting rod of linkage connection handle and jump buckle in the installation cavity, and the lock catch that cooperates with jump buckle locks, the contact support that links to each other with lock catch, the movable contact that sets up in contact support one end, static contact one side is equipped with electromagnetic release, static contact has piezo -resistor electricity, piezo -resistor has switch type component electricity, switch type component and wiring seat electricity are connected, its characterized in that: piezo -resistor with static contact between being equipped with thermal separation structure, the utility model has the advantages of: when piezo -resistor temperature abnormally rises and can be active, physically from the circuit disconnect, solve piezo -resistor ageing failure's thermal runaway safety problem, realize the safety failure of product.

Description

Technical Field

[0001] This utility model relates to the field of lightning protection equipment, specifically to a backup surge protector with short-circuit protection and thermal protection. Background Technology

[0002] Surge protectors in circuits can discharge surge current to the ground through a grounding loop to prevent overvoltage damage to downstream equipment; backup protectors can cut off fault current when surge protectors fail to prevent fault current from burning out surge protectors.

[0003] The backup surge protector with patent number ZL202322549411.3 includes a housing and a top cover. The housing and top cover form a mounting cavity, which houses an electromagnetic trip unit, a moving contact and its associated structures, a varistor, and a switching component. The varistor is electrically connected to the switching component. When a surge occurs, the varistor's resistance drops sharply, conducting and discharging the surge current. When the surge is too large, the switching component conducts and discharges current, simultaneously triggering the electromagnetic trip unit to strike the moving contact and disconnect the circuit. This device achieves an integrated design of a surge protector and a backup protector.

[0004] However, the device has a safety defect: when the varistor ages due to long-term operation or repeated surge impacts, causing its normal resistance to decrease, its leakage current may rise from the μA level to the mA level. The varistor will accumulate heat, but at this time, no surge occurs, and the internal current of the device does not reach the level to trigger the electromagnetic trip unit. The device circuit cannot be disconnected, and the heat accumulation of the varistor cannot be resolved. The heat accumulation of the varistor leads to the risk of the entire device catching fire. Utility Model Content

[0005] The purpose of this invention is to provide a backup surge protector with short-circuit protection and thermal protection, in order to solve the problem in the prior art where the backup surge protector cannot disconnect the circuit when there is no surge but the varistor is heated, which may lead to combustion and fire.

[0006] To achieve the above objectives, the technical solution adopted by this utility model is as follows: A backup surge protector with short-circuit and thermal protection includes a housing and a top cover. The housing and top cover form a mounting cavity. The mounting cavity contains a stationary contact, a terminal block, a rotatable handle, a rotatable trip latch, a linkage connecting the handle and the trip latch, a latch that engages with the trip latch, a contact bracket linked to the latch, and a moving contact at one end of the contact bracket. An electromagnetic trip device is provided on one side of the stationary contact. The stationary contact is electrically connected to a varistor, and the varistor is electrically connected to a switching component. The switching component is electrically connected to the terminal block. The feature is that a thermal separation structure is provided between the varistor and the stationary contact.

[0007] By adopting the above technical solution, a thermal separation structure is set between the varistor and the stationary contact. When the varistor's temperature rises abnormally due to aging, the thermal separation structure can actively and physically disconnect the varistor from the circuit, completely cutting off the current path. This fundamentally eliminates the fire hazard caused by thermal runaway and achieves safe failure of the product.

[0008] The above technical solution can be further configured as follows: the thermal separation structure includes an elastic conductive element fixedly connected to a stationary contact at one end, a first connecting part disposed on the side of the varistor near the elastic conductive element, and a low-melting-point solder. The fixed end of the elastic conductive element is also connected to the stationary contact. The end of the elastic conductive element away from the stationary contact is provided with a second connecting part that can be elastically deformed. After the second connecting part is deformed, it is connected to the first connecting part. The first connecting part and the second connecting part are fixed by welding with the low-melting-point solder. After the second connecting part and the first connecting part are fixed, they can be separated by heat.

[0009] The above technical solution employs a structure that thermally separates the first connecting part from the second connecting part, utilizing the deformation characteristics of the elastic conductive element. This maintains a reliable electrical connection at room temperature and achieves rapid separation at high temperatures through deformation recovery. The structure is simple, the operation is reliable, and automatic protection can be achieved without external control. By using low-melting-point solder to fix the first and second connecting parts, when the temperature of the varistor rises to the solder's melting point, the solder melts rapidly, releasing the elastic conductive element, causing it to spring open and disconnect the circuit. This results in a fast response, thorough separation, and is inexpensive and easy to implement.

[0010] The above technical solution can be further configured as follows: the switching component includes two graphite sheets arranged opposite each other, a discharge gap is formed between the two graphite sheets, an electrode plate is provided on the side of each graphite sheet away from the discharge gap, the switching component is disposed between the terminal block and the varistor, the electrode plate of the switching component near the varistor is electrically connected to the varistor, and the electrode plate of the switching component near the terminal block is electrically connected to the terminal block.

[0011] By adopting the above technical solution and using a switching component including two oppositely arranged graphite sheets and a discharge gap, it is possible to break down and discharge when the surge voltage is too high, dissipate a large amount of current, and at the same time protect the varistor from overcurrent damage, thereby enhancing the overall surge withstand capability and reliability of the protector.

[0012] The above technical solution can be further configured as follows: the handle includes a handle body and an operating part. The handle body is rotatably mounted on the housing. One end of the operating part is connected to the handle body, and the other end of the operating part protrudes from the housing. One end of the connecting rod is connected to the handle body, and the other end of the connecting rod is connected to the jump buckle. The jump buckle is rotatably connected to the upper end of the contact bracket. The contact bracket is rotatably mounted on the housing. The lock is rotatably mounted on the contact bracket. The upper end of the lock has a limiting slot, and the jump buckle engages with the limiting slot. The lower end of the lock has a limiting block for limiting the lock. The upper end of the moving contact is connected to the lower end of the contact bracket, and the lower end of the moving contact abuts against the stationary contact.

[0013] Using the above technical solution, when the electromagnetic trip unit strikes the contact bracket and drives the moving contact to move, the contact bracket drives the trip buckle to move. The trip buckle pushes the handle to rotate through the connecting rod, and the latch rotates around the contact bracket to keep the limit lock and the trip buckle locked stably. When the handle is rotated and the moving contact is reset, the handle pushes the trip buckle through the connecting rod. The trip buckle drives the contact bracket to rotate on the housing, which in turn drives the moving contact to move. The contact bracket abuts against the limit block, and the latch will not rotate arbitrarily due to the pressure of the trip buckle.

[0014] The above technical solution can be further configured such that: the housing mounting cavity is also provided with a micro switch and a terminal block, and the terminal block is connected to the micro switch and the stationary contact respectively through wires.

[0015] By employing the above technical solution and configuring a microswitch and a terminal block, when the circuit is normal, the terminal block will output a normal operation signal to the remote control room. When the moving contact actuates and triggers the microswitch, the microswitch outputs a signal to the terminal block, which in turn outputs a surge signal to the remote control room. When thermal separation is triggered, the entire protector is disconnected, and the terminal block transmits a failure signal to the remote control room. This enables remote monitoring of fault conditions, facilitating timely problem detection and handling by maintenance personnel, and improving the product's human-machine interface and safety.

[0016] The above technical solution can be further configured such that one end of the electromagnetic trip unit is electrically connected to the stationary contact, and the other end of the electromagnetic trip unit is electrically connected to the terminal block.

[0017] By adopting the above technical solution, the electromagnetic trip unit is directly connected between the stationary contact and the terminal block, ensuring that the electromagnetic trip unit can act quickly in the event of a short circuit or excessive surge current, striking and driving the moving contact to separate from the stationary contact, providing effective backup protection and preventing the accident from escalating.

[0018] The beneficial effects of this utility model are: when the temperature of the varistor rises abnormally, it can be actively and physically disconnected from the circuit, completely eliminating the fire hazard, effectively solving the thermal runaway safety problem when the varistor fails due to aging, and realizing the safe failure of the product.

[0019] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the overall structure of this utility model; Figure 2 This is a schematic diagram of the normal working state of this utility model; Figure 3 This is a schematic diagram of the triggered thermal separation state of this utility model; Figure 4 This is a schematic diagram illustrating the over-surge protection state triggered by this utility model; Figure 5 This is an enlarged view of the motion structure of this utility model; Labeling notes: 1. Housing; 2. Top cover; 3. Mounting cavity; 4. Stationary contact; 5. Terminal block; 6. Handle; 7. Jumper; 8. Linkage rod; 9. Lock; 91. Limiting slot; 92. Limiting block; 10. Contact bracket; 11. Moving contact; 12. Electromagnetic trip unit; 13. Varistor; 14. Switching component; 141. Graphite sheet; 142. Discharge gap; 143. Electrode plate; 15. Thermal separation structure; 151. Elastic conductive element; 152. First connecting part; 153. Second connecting part. Detailed Implementation

[0021] The technical solutions in the embodiments of this utility model will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0022] like Figure 1 , Figure 2 and Figure 5As shown, a backup surge protector with short-circuit and thermal protection includes a housing 1 and a top cover 2, which together form a mounting cavity 3. The mounting cavity 3 contains a stationary contact 4, a terminal block 5, a rotatable handle 6, a rotatable trip latch 7, a connecting rod 8 linking the handle 6 and the trip latch 7, a locking latch 9 that engages with the trip latch 7, a contact bracket 10 linked to the locking latch 9, and a moving contact 11 located at the end of the contact bracket 10 away from the trip latch 7. The stationary contact bracket 10 is rotatably mounted on the housing 1 in the middle. Part of the handle 6 is exposed in the mounting cavity 3 for easy manual operation. The trip latch 7 engages with the locking latch 9's limiting slot 91, preventing the trip latch 7 from rotating freely. A limiting block 92 is located at the lower end of the locking latch 9, abutting against the lower end of the contact bracket 10 to limit the locking latch 9, thereby limiting the trip latch 7. An electromagnetic trip unit 12 is provided on the upper side of the stationary contact 4. One end of the electromagnetic trip unit 12 is electrically connected to the stationary contact 4, and the other end of the electromagnetic trip unit 12 is electrically connected to the terminal block 5. When the moving contact 11 separates from the stationary contact 4, the electromagnetic trip unit 12 will also be de-energized. A varistor 13 is electrically connected to the stationary contact 4, and a switching component 14 is electrically connected to the varistor 13. The switching component 14 is electrically connected to the terminal block 5. When the electromagnetic trip unit 12 strikes the contact bracket 10, causing the moving contact 11 to move, the contact bracket 10 causes the jump buckle 7 to move. The jump buckle 7 pushes the handle 6 to rotate via the connecting rod 8, and the latch 9 rotates around the contact bracket 10 to keep the limit latch 91 and the jump buckle 7 locked stably. When the handle 6 is rotated to reset the moving contact 11, the handle pushes the jump buckle 7 via the connecting rod 8. The jump buckle 7 causes the contact bracket 10 to rotate on the housing 1, thereby causing the moving contact 11 to move. The contact bracket 10 abuts against the limit block 92, and the latch 9 will not rotate arbitrarily due to the pressure of the jump buckle 7.

[0023] The switching component 14 includes two opposing graphite sheets 141, forming a discharge gap 142 between them, where surge current is discharged during a surge. Each graphite sheet 141 has an electrode plate 143 on the side away from the discharge gap 142. The switching component 14 is positioned between the terminal block 5 and the varistor 13, with the electrode plate 143 near the varistor 13 electrically connected to it, and the electrode plate 143 near the terminal block 5 electrically connected to it. A thermal separation structure 15 is positioned between the varistor 13 and the stationary contact 4, including an elastic conductive element 151 fixedly connected to the stationary contact 4 at one end, and a first connecting portion 152 on the side of the varistor 13 near the elastic conductive element 151. The fixed end of the elastic conductive element 151 is connected to the stationary contact 4, and the end away from the stationary contact 4 has a second elastically deformable connecting portion 153. After deformation, the second connecting part 153 connects to the first connecting part 152 and is fixed by welding with low melting point solder.

[0024] The working principle of this embodiment is as follows: like Figure 2 As shown, during normal operation, the moving contact 11 abuts against the stationary contact 4, and the second connecting part 153 is welded to the first connecting part 152. At this time, the handle 6 is positioned to the right.

[0025] like Figure 3 As shown, when the device is short-circuited or when a surge occurs, the instantaneous large current triggers the electromagnetic trip unit 12 to strike the contact bracket 10, causing the moving contact 11 to separate from the stationary contact 4 and cut off the circuit.

[0026] like Figure 4 As shown, when there is no surge or short circuit but the leakage current of the varistor 13 increases and the temperature of the varistor 13 rises abnormally, the low-temperature solder melts, the second connection part 153 bounces back and separates from the first connection part 152, thereby cutting off the device circuit and preventing the varistor 13 from continuing to accumulate heat.

[0027] The mounting cavity 3 is also equipped with a micro switch 17 and a terminal block 18. The terminal block 18 is connected to the micro switch 17 and the stationary contact 4 respectively via wires 19. When the circuit is normal, or when the moving contact 11 is activated, or when the thermal separation structure 15 is triggered, the terminal block 18 can output different signals to the remote control room to realize remote monitoring of the fault status.

[0028] The embodiments described above are merely examples of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these modifications and improvements all fall within the protection scope of this utility model.

Claims

1. A backup surge protector with short-circuit and thermal protection, comprising a housing and a top cover, wherein the housing and the top cover form a mounting cavity, and the mounting cavity is provided with a stationary contact, a terminal block, a rotatable handle, a rotatable trip latch, a linkage connecting the handle and the trip latch, a latch that engages with and locks the trip latch, a contact bracket that engages with the latch, and a moving contact disposed at one end of the contact bracket; an electromagnetic trip device is provided on one side of the stationary contact; the stationary contact is electrically connected to a varistor; the varistor is electrically connected to a switching component; and the switching component is electrically connected to the terminal block, characterized in that: A thermal separation structure is provided between the varistor and the stationary contact.

2. The backup surge protector with short circuit protection and thermal protection of claim 1, wherein: The thermal separation structure includes an elastic conductive element fixedly connected to a stationary contact at one end, a first connecting portion disposed on the side of the varistor near the elastic conductive element, and a low-melting-point solder. The fixed end of the elastic conductive element is also connected to the stationary contact. The end of the elastic conductive element away from the stationary contact is provided with a second connecting portion that can elastically deform. After deformation, the second connecting portion connects to the first connecting portion. The first connecting portion and the second connecting portion are fixed by welding with the low-melting-point solder. After the second connecting portion and the first connecting portion are fixed, they can be separated by heat.

3. The backup surge protector with short circuit protection and thermal protection of claim 1, wherein: The switching component includes two graphite sheets arranged opposite each other, with a discharge gap formed between the two graphite sheets. Each graphite sheet has an electrode plate on the side away from the discharge gap. The switching component is disposed between a terminal block and a varistor. The electrode plate of the switching component near the varistor is electrically connected to the varistor, and the electrode plate of the switching component near the terminal block is electrically connected to the terminal block.

4. The backup surge protector with short circuit protection and thermal protection of claim 1, wherein: The handle includes a handle body and an operating part. The handle body is rotatably mounted on the housing. One end of the operating part is connected to the handle body, and the other end of the operating part protrudes from the housing. One end of the connecting rod is connected to the handle body, and the other end of the connecting rod is connected to the jump buckle. The jump buckle is rotatably connected to the upper end of the contact bracket. The contact bracket is rotatably mounted on the housing. The lock is rotatably mounted on the contact bracket. The upper end of the lock has a limiting slot, and the jump buckle engages with the limiting slot. The lower end of the lock has a limiting block for limiting the lock. The upper end of the moving contact is connected to the lower end of the contact bracket, and the lower end of the moving contact abuts against the stationary contact.

5. The backup surge protector with short circuit protection and thermal protection of claim 1, wherein: The housing mounting cavity is also provided with a micro switch and a terminal block, which is connected to the micro switch and the stationary contact respectively via wires.

6. The backup surge protector with short circuit protection and thermal protection according to any one of claims 1-5, characterized in that: One end of the electromagnetic trip unit is electrically connected to the stationary contact, and the other end of the electromagnetic trip unit is electrically connected to the terminal block.

Images