CN115359981B - Thermal protection piezoresistor module - Google Patents

Abstract

The invention belongs to the technical field of piezoresistors, in particular to a thermal protection piezoresistor module which comprises a packaged piezoresistor block, a shell and a thermal protection unit arranged in the shell, wherein the shell is provided with a plurality of heat insulation layers; the thermal protection unit comprises a conductive plate, a push rod and a connecting plate; the thermal protection piezoresistor module designed by the invention has the advantages that the connecting plate and the conducting plate are components with directly raised temperature, so that the welding point with low melting point is heated and melted, the guide tube and the push rod are indirectly heated by radiation, meanwhile, the guide tube and the push rod are made of high-temperature resistant insulating materials, such as liquid crystal polymer materials, and can bear the temperature of 315 ℃ at most, even the temperature is 200 ℃, slight deformation can be generated, sliding connection between the push rod and the guide tube is not influenced, separation between the connecting plate and the conducting plate is ensured, part of heat on the connecting plate can be prevented from being transferred to the spring, and the elasticity of the spring is protected.

Description

A thermal protection varistor module

Technical Field

The invention belongs to the technical field of varistor, in particular to a thermal protection varistor module.

Background technique

The varistor is welded on the circuit board and is a voltage-limiting protection device that protects equipment or electrical products. When the varistor is working and a surge current or overvoltage appears in the circuit, the varistor will switch to a working state, but this also brings other problems. The existing varistor is a packaged structure, which is packaged into blocks with epoxy resin materials, resulting in heat generated inside the varistor. In severe cases, the temperature is too high and reaches the combustion temperature point of the varistor. The varistor catches fire and burns, touching the surrounding electronic components and causing greater losses.

According to a patent application with publication number CN101261893A, a thermal protection varistor module for surge protection is disclosed. The thermal protection varistor module softens the solder joint of the low-melting-point solder. Under the joint action of a pusher with a spring and a wedge-shaped arc extinguisher and a conductive connecting arm with resilience, the solder joint is forced to disconnect quickly and the wedge-shaped arc extinguisher is partially inserted into the gap formed at the solder joint break, thereby enhancing the arc extinguishing effect. In addition, the application states that "the thermal response switch assembly 16 is composed of a conductive connecting arm 21 with resilience, a low-melting-point welding point 29 and the first short conductive terminal 12a of MOV11". The conductive connecting arm 21 with resilience is used to conduct current. When the current and voltage are overloaded, the temperature rises. After multiple heating, the conductive connecting arm 21 with resilience will gradually lose its elasticity and become smaller. The low-melting-point welding point 29 melts, and the conductive connecting arm 2 may fail to rebound, resulting in the loss of thermal protection.

To this end, the present invention provides a thermal protection varistor module.

Summary of the invention

In order to make up for the deficiencies of the prior art, at least one technical problem raised in the background technology is solved.

The technical solution adopted by the present invention to solve the technical problem is as follows: a thermal protection varistor module described in the present invention includes a packaged varistor block, a shell and a thermal protection unit arranged in the shell; the thermal protection unit includes a conductive plate, a push rod and a connecting plate; the lower end surface of the shell is symmetrically provided with two power connection plates, the two power connection plates extend into the shell, the inner end of the power connection plate is fixedly connected to one power connection pin of the packaged varistor block, the other power connection pin of the packaged varistor block extends vertically upward and is embedded in a jack on one side of the lower surface of the connecting plate, and the lower surface of the connecting plate is A socket is provided in the middle of the surface, one end of a conductive plate is welded in the socket, the other end of the conductive plate is vertically fixedly connected to the inner end of another power board, and a through hole is provided in the middle horizontal position of the conductive plate; the lower surface of the connecting plate is symmetrically provided with guide tubes, the guide tubes are slidably connected to one end of the push rods through a spring, the other end of one of the push rods vertically passes through the through hole and extends to the outside of the shell, and the other push rod extends vertically to the outside of the shell; in the present invention, the lower surface of the shell is attached to the surface of the circuit board, the circuit board squeezes the push rod into the guide tube, the temperature of the conductive plate and the connecting plate rises in the overloaded circuit, and the guide tube The low melting point welding point between the electric board and the socket melts. The low melting point welding point is made of harmless metal material, such as materials that do not contain lead or cadmium, and its melting temperature is between 100°C and 165°C. The fixing force between the conductive plate and the socket is lost. At the same time, under the upward push of the spring in the guide tube, the socket on the connecting plate is separated from one end of the conductive plate, and the jack on one side of the lower surface of the connecting plate is separated from the other power pin of the packaged varistor block. At this time, the packaged varistor block is disconnected from the conductive plate, and the circuit is in a disconnected state, thereby realizing the function of protecting the circuit. The thermal protection device designed by the present invention Protect the varistor module, the connecting plate and the conductive plate are components that directly increase the temperature, so that the low-melting-point welding points are melted by heat, and the guide tube and the push rod are indirectly heated by radiation. At the same time, the guide tube and the push rod are made of some high-temperature resistant insulating materials, such as liquid crystal polymer materials, which can withstand a maximum temperature of 315°C. Even at 200°C, only slight deformation will occur, which will not affect the sliding connection between the push rod and the guide tube, ensuring the separation between the connecting plate and the conductive plate. At the same time, it can also block part of the heat on the connecting plate from being transferred to the spring, which is also a protection for the elasticity of the spring.

Preferably, a second socket is provided on the other side of the lower surface of the connecting plate, and a balancing plate is provided in the second socket, and the balancing plate is vertically fixed to the middle horizontal surface of the conductive plate; two guide tubes are placed on the top of the connecting plate, and a first socket on one side of the lower surface of the connecting plate is connected to another electrical connection pin of the packaged varistor block. When the electrical connection pin is separated from the first socket, there will be sliding friction, which will affect the vertical upward and smooth movement of the connecting plate, causing the connecting plate to be skewed, and the resistance of the first socket on one side of the lower surface of the connecting plate to be separated from the electrical connection pin increases, and the socket is not smoothly separated from the conductive plate. To balance the upward movement of the connecting plate, a balancing plate is provided on the conductive plate, so that the force on both ends of the connecting plate is evenly distributed, and the connecting plate moves upward smoothly and steadily, thereby ensuring the power-off protection performance of the thermal protection varistor module.

Preferably, a placement groove is provided in the middle position of the top surface of the shell, and a magnetic plate is fixed in the placement groove; a metal plate is fixed to the upper surface of the connecting plate; even if the spring in the guide tube loses some elasticity under long-term compression or in a heated state for a long time, the metal plate can be adsorbed by the magnetic plate to drive the connecting plate to move up; the metal plate is an iron metal plate, which is fixed to the connecting plate, and after the low-melting-point welding point melts, the magnetic plate adsorbs the metal plate to drive the connecting plate to move up and be placed in the placement groove, thereby realizing the power-off thermal protection function, that is, the connecting plate is pushed up by the push rod to detach from the conductive plate, and is detached from the protection by adsorption of the magnetic plate, or both detach from the power-off protection at the same time.

Preferably, guide rods are symmetrically fixed to both ends of the connecting plate; vertical plates are symmetrically provided on the top surface of the shell, and slide grooves are provided on the vertical plates along their length directions, and the guide rods are slidably connected in the slide grooves; the movement of the connecting plate is guided by the provided vertical plates, so that it moves smoothly along the slide groove toward the placement groove, further ensuring the smooth movement of the connecting plate, and at the same time the guide rods are restricted in the slide groove, when the thermal protection varistor module is powered off, the shell is disassembled later and the connecting plate is reset, and at this time the guide rods can assist the socket in aligning and welding with the conductive plate, thereby ensuring the electrical connection of the effective conductive parts and facilitating the operator to weld the two.

Preferably, a recess is provided at the middle position of both sides of each of the power connection boards, a fixing hole is provided through the upper edge of the recess, a notch is provided on one side of the fixing hole, and an elastic plate is provided in the recess; the elastic plate is L-shaped, one end of the elastic plate is fixedly connected to a connecting column, the connecting column is embedded in the fixing hole, the elastic plate is embedded in the notch, and the corner position of the elastic plate is welded at the inner corner of the recess; a hole edge of the fixing hole is symmetrically provided with a notch, and a limiting hole is provided on the inner surface of the notch; a convex portion is provided at one end of the connecting column, the shape of the convex portion is adapted to the shape of the notch, a limiting column is provided on the end face of the convex portion, the limiting column points to the other end of the connecting column, and the convex portion is embedded in the notch, and the limiting column is embedded in the limiting hole; the power connection board is inserted into the welding hole on the circuit board, and then soldered by melting solder. Generally, there are manual welding and machine welding. The quality of machine welding is better than that of manual welding, and the problem of empty welding or cold welding is inevitable when manual concentration and long-term welding operations are performed, which will make it difficult for the power connection board to be attached to On the circuit board, the machine or equipment is in operation, which drives the circuit board to vibrate at a high frequency. In severe cases, the empty soldering or cold soldering of the power board will be vibrated out of the welding hole. For this reason, an elastic plate is arranged on the power board. In the initial state, the corner position of the elastic plate is welded at the inner corner position of the recess. When the power board is welded on the circuit board, the solder at the inner corner position of the recess is melted by using an electric soldering iron. At this time, the elastic plate is in its own elastic shape, and the other end of the elastic plate is attached to the circuit board. The elastic plate acts as a conductive sheet at this time, connecting the welding hole and the power board. Even if there is an empty soldering or cold soldering, the power board and the welding hole can be energized. The cooperation of the connecting column and the notch makes it more convenient to assemble the elastic plate and the power board, and the cooperation of the limiting hole and the limiting column makes the elasticity of the elastic plate effectively act on the circuit board, ensuring the elasticity of the elastic plate, and the thermal protection varistor module can be effectively stabilized on the circuit board. The other end of the elastic plate is attached to the circuit board, and then the power board is soldered to the welding hole position by soldering.

Preferably, a groove is provided on the inner corner surface of the recess; a through hole is provided at the corner position of the elastic plate; when the elastic plate is welded to the recess, the end of the soldering iron and the end of the welding rod extend to the through hole position, the solder melts and solidifies, and this facilitates the melting of the solder to flow to the inner corner position of the recess, effectively welding and fixing the elastic plate.

Preferably, baffles are symmetrically provided at the corners of the elastic plate, the baffles are triangular in shape, and are fixedly connected to the edge positions on both sides of the elastic plate; when the elastic plate is separated from the recess, the residual molten solder on the elastic plate splashes to the surrounding area at the moment the elastic plate swings, which can easily cause a short circuit in the circuit board. For this purpose, a baffle is provided, and at the moment the elastic plate is separated from the recess, the baffle blocks the molten solder in the elastic plate to prevent the solder from splashing and causing a short circuit in components on the circuit board.

Preferably, a rotation groove is provided at the outer end of each of the power connection boards, a pressure plate is provided in the rotation groove, rotation holes are provided on both sides of the rotation groove, a pressure plate is provided in the rotation groove, a threaded hole is provided in the middle of the pressure plate, rotation pins are fixedly connected on both sides of one end of the pressure plate, and the rotation pins are tightly rotatably connected in the rotation holes; after the power connection boards are welded, the pressure plate is rotated so that the pressure plate rotates toward the inside of the two power connection boards, and then the screw thread penetrates the threaded hole so that the end of the screw is against the circuit board, thereby further fixing the thermal protection varistor module on the circuit board.

Preferably, screws are symmetrically provided on both sides of the shell, one end of the screw thread penetrates the upper surface of the shell, and the other end of the screw thread penetrates the lower surface of the shell; according to the thickness of the circuit board, the screw is rotated so that the circuit board squeezes the elastic plate, which helps the other end of the elastic plate to effectively grip the welding hole position of the circuit board.

Preferably, a rubber pad is fixedly connected to the other end of the screw rod; by providing the rubber pad, the other end of the screw rod is prevented from scratching and damaging the surface of the circuit board due to rotation, causing the circuit board to short-circuit or open-circuit.

The beneficial effects of the present invention are as follows:

1. A thermal protection varistor module described in the present invention, the thermal protection varistor module designed by the present invention, the connecting plate and the conductive plate are components that directly increase the temperature, so that the low-melting point welding point is melted by heat, and the guide tube and the push rod are indirectly heated by radiation. At the same time, the guide tube and the push rod are made of some high-temperature resistant insulating materials, such as liquid crystal polymer materials, which can withstand a maximum temperature of 315°C. Even at 200°C, only slight deformation will occur, which will not affect the sliding connection between the push rod and the guide tube, ensuring the separation between the connecting plate and the conductive plate, and also blocking part of the heat on the connecting plate from being transferred to the spring, which is also a protection for the elasticity of the spring.

2. The thermal protection varistor module described in the present invention balances the upward movement of the connecting plate, and a balancing plate is arranged on the conductive plate so that the two ends of the connecting plate are evenly stressed and move upward steadily and smoothly, thereby ensuring the power-off protection performance of the thermal protection varistor module.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be further described below in conjunction with the accompanying drawings.

FIG1 is a perspective view of a thermal protection varistor module of the present invention;

FIG2 is a partial enlarged view of point A in FIG1;

FIG3 is a front cross-sectional view of a thermal protection varistor module in the present invention;

FIG4 is a perspective view of the power board of the present invention;

FIG5 is a front view of the power board of the present invention;

FIG6 is a perspective view of the elastic plate of the present invention;

FIG7 is a diagram showing the cooperation between the screw and the housing in the present invention;

In the figure: packaged varistor block 001, shell 1, conductive plate 2, push rod 3, connecting plate 4, power board 5, power pin 6, jack 1 7, socket 8, guide tube 9, spring 10, jack 2 11, balance plate 12, magnetic plate 13, metal plate 14, guide rod 15, vertical plate 16, recess 17, fixing hole 18, notch 19, elastic plate 20, connecting column 21, recess 22, limiting hole 23, convex part 24, limiting column 25, groove 26, through hole 27, baffle 28, rotating groove 29, pressure plate 30, threaded hole 31, rotating hole 32, screw 33, rubber pad 34.

Detailed ways

In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further explained below in conjunction with specific implementation methods.

Embodiment 1:

Referring to Fig. 1, Fig. 2 and Fig. 3, a thermal protection varistor module includes a packaged varistor block 001, a housing 1 and a thermal protection unit arranged in the housing 1; the thermal protection unit includes a conductive plate 2, a push rod 3 and a connecting plate 4; the lower end surface of the housing 1 is symmetrically provided with two power connection plates 5, the two power connection plates 5 extend into the housing 1, the inner end of the power connection plate 5 is fixedly connected to one power connection pin 6 of the packaged varistor block 001, the other power connection pin 6 of the packaged varistor block 001 extends vertically upward and is embedded in a socket 7 on one side of the lower surface of the connecting plate 4, and the middle position of the lower surface of the connecting plate 4 is provided The socket 8 has one end of a conductive plate 2 welded inside the socket 8, and the other end of the conductive plate 2 is vertically fixedly connected to the inner end of another power board 5, and a through hole is provided in the middle horizontal position of the conductive plate 2; the lower surface of the connecting plate 4 is symmetrically provided with a guide tube 9, and the guide tube 9 is slidably connected to one end of a push rod 3 through a spring 10, wherein the other end of one push rod 3 vertically passes through the through hole and extends to the outside of the shell 1, and the other push rod 3 vertically extends to the outside of the shell 1; in the present invention, the lower surface of the shell 1 is attached to the surface of the circuit board, and the circuit board squeezes the push rod 3 into the guide tube 9, and the temperature of the conductive plate 2 and the connecting plate 4 rises in an overloaded circuit, and the conductive plate The low melting point welding point between the conductive plate 2 and the socket 8 melts. The low melting point welding point is made of harmless metal material, such as materials that do not contain lead or cadmium, and its melting temperature is between 100°C and 165°C. The conductive plate 2 and the socket 8 lose their fixed connection force. At the same time, under the upward push of the spring 10 in the guide tube 9, the socket 8 on the connecting plate 4 is separated from one end of the conductive plate 2, and the socket 7 on one side of the lower surface of the connecting plate 4 is separated from the other electrical connection pin 6 of the packaged varistor block 001. At this time, the packaged varistor block 001 is disconnected from the conductive plate 2, and the circuit is in a disconnected state, thereby realizing the function of protecting the circuit. The thermal protection circuit designed by the present invention To protect the varistor module, the connecting plate 4 and the conductive plate 2 are components that directly increase the temperature, so that the low-melting-point welding points are melted by heat, and the guide tube 9 and the push rod 3 are indirectly heated by radiation. At the same time, the guide tube 9 and the push rod 3 are made of some high-temperature resistant insulating materials, such as liquid crystal polymer materials, which can withstand a maximum temperature of 315°C. Even at 200°C, only slight deformation will occur, which will not affect the sliding connection between the push rod 3 and the guide tube 9, ensuring the separation between the connecting plate 4 and the conductive plate 2. At the same time, it can also block part of the heat on the connecting plate 4 from being transferred to the spring 10, which is also a protection for the elasticity of the spring 10.

Referring to Figures 1 and 3, a second socket 11 is provided on the other side of the lower surface of the connecting plate 4, and a balancing plate 12 is provided in the second socket 11. The balancing plate 12 is vertically fixed to the middle horizontal surface of the conductive plate 2; two guide tubes 9 are placed on the top of the connecting plate 4, and a socket 7 on one side of the lower surface of the connecting plate 4 is connected to another electrical connection pin 6 of the packaged varistor block 001. When the electrical connection pin 6 is separated from the socket 7, there will be sliding friction, which will affect the vertical upward and smooth movement of the connecting plate 4, causing the connecting plate 4 to be skewed, and the resistance of the socket 7 on one side of the lower surface of the connecting plate 4 to be separated from the electrical connection pin 6 increases, and the socket 8 is not smooth enough to separate from the conductive plate 2. For this reason, the upward movement of the balancing plate 12 is set on the conductive plate 2 to balance the upward movement of the connecting plate 4, so that the two ends of the connecting plate 4 are evenly stressed, and move upward steadily and smoothly, thereby ensuring the power-off protection performance of the thermal protection varistor module.

1 and 2, a placement groove is provided in the middle of the top surface of the shell 1, and a magnetic plate 13 is fixed in the placement groove; a metal plate 14 is fixed to the upper surface of the connecting plate 4; even if the spring 10 in the guide tube 9 loses some elasticity under long-term extrusion or in a heated state for a long time, the metal plate 14 can be adsorbed by the magnetic plate 13 to drive the connecting plate 4 to move upward; the metal plate 14 is an iron metal plate 14, which is fixed to the connecting plate 4, and after the low-melting-point welding point melts, the magnetic plate 13 adsorbs the metal plate 14, drives the connecting plate 4 to move upward and be placed in the placement groove, thereby realizing the power-off thermal protection function, that is, the connecting plate 4 is pushed up by the push rod 3 to separate from the conductive plate 2, and is separated from the protection by the magnetic plate 13 adsorption, or both are separated from the power-off protection at the same time.

1 and 2, guide rods 15 are symmetrically fixed to both ends of the connecting plate 4; vertical plates 16 are symmetrically provided on the top surface of the shell 1, and slide grooves are provided on the vertical plates 16 along their length direction, and the guide rods 15 are slidably connected in the slide grooves; the movement of the connecting plate 4 is guided by the provided vertical plates 16, so that it moves smoothly along the slide groove toward the placement groove direction, further ensuring the smooth movement of the connecting plate 4, and at the same time the guide rods 15 are restricted in the slide groove, when the thermal protection varistor module is powered off, the shell 1 is disassembled later, and the connecting plate 4 is reset, and at this time the guide rods 15 can assist the socket 8 to align and weld with the conductive plate 2, thereby ensuring the electrical connection of the effective conductive parts and facilitating the operator to weld the two.

4 and 6, a recess 17 is provided at the middle position of both sides of each of the power connection plates 5, a fixing hole 18 is provided through the upper edge of the recess 17, a notch 19 is provided on one side of the fixing hole 18, and an elastic plate 20 is provided in the recess 17; the elastic plate 20 is in the shape of L, a connecting column 21 is fixedly connected to one end of the elastic plate 20, the connecting column 21 is embedded in the fixing hole 18, the elastic plate 20 is embedded in the notch 19, and the corner position of the elastic plate 20 is welded at the inner corner of the recess 17; a notch 22 is symmetrically provided at the edge of one hole of the fixing hole 18, and a limit stop is provided on the inner surface of the notch 22 Hole 23; one end of the connecting column 21 is provided with a convex portion 24, the shape of the convex portion 24 is adapted to the shape of the concave portion 22, the end face of the convex portion 24 is provided with a limiting column 25, the limiting column 25 points to the other end of the connecting column 21, and the convex portion 24 is embedded in the concave portion 22, and the limiting column 25 is embedded in the limiting hole 23; the power board 5 is inserted into the welding hole on the circuit board, and then the solder is melted and welded. Generally, there are manual welding and machine welding. The quality of machine welding is better than that of manual welding, and it is inevitable that empty welding or cold welding will occur due to manual concentration and long-term welding operations. This will make it difficult for the power board 5 to be attached to the circuit board. When the machine or equipment is in operation, it drives the circuit board to vibrate at a high frequency. In severe cases, the power board 5 with empty soldering or poor soldering will be vibrated out of the welding hole. For this reason, an elastic plate 20 is arranged on the power board 5. In the initial state, the corner position of the elastic plate 20 is welded to the inner corner position of the recess 17. When the power board 5 is welded to the circuit board, an electric soldering iron is used to melt the solder at the inner corner position of the recess 17. At this time, the elastic plate 20 is in its own elastic shape, and the other end of the elastic plate 20 is attached to the circuit board. The elastic plate 20 acts as It is a conductive sheet, connecting the welding hole and the power board 5, and even if there is an empty weld or a cold weld, the power board 5 and the welding hole can be powered; the connection column 21 cooperates with the notch 19, making it convenient to assemble the elastic plate 20 and the power board 5, and the limit hole 23 cooperates with the limit column 25, so that the elasticity of the elastic plate 20 can effectively act on the circuit board, ensuring the elasticity of the elastic plate 20, and the thermal protection varistor module can be effectively stabilized on the circuit board; the other end of the elastic plate 20 is attached to the circuit board, and then the power board 5 is soldered to the welding hole position by soldering.

1, 3 and 6, a groove 26 is provided on the inner corner surface of the recess 17, and a through hole 27 is provided at the corner position of the elastic plate 20; when the elastic plate 20 is welded to the recess 17, the end of the electric soldering iron and the end of the welding rod extend to the position of the through hole 27, the solder melts and solidifies, and this facilitates the melting of the solder to flow to the inner corner position of the recess 17, effectively welding and fixing the elastic plate 20.

6 , baffles 28 are symmetrically provided at the corners of the elastic plate 20. The baffles 28 are triangular in shape and fixed to the edge positions on both sides of the elastic plate 20. When the elastic plate 20 is separated from the recess 17, the residual molten solder on the elastic plate 20 splashes to the surrounding area at the moment when the elastic plate 20 swings, which may easily cause a short circuit in the circuit board. For this reason, the baffles 28 are provided. At the moment when the elastic plate 20 is separated from the recess 17, the baffles 28 block the molten solder in the elastic plate 20 to prevent the solder from splashing and causing a short circuit in the components on the circuit board.

4 and 5 , a rotation groove 29 is provided at the outer end of each of the power connection plates 5 , a pressure plate 30 is provided in the rotation groove 29 , rotation holes 32 are provided on both sides of the rotation groove 29 , a pressure plate 30 is provided in the rotation groove 29 , a threaded hole 31 is provided in the middle of the pressure plate 30 , rotation pins are fixedly connected to both sides of one end of the pressure plate 30 , and the rotation pins are tightly rotatably connected in the rotation holes 32 ; after the power connection plates 5 are welded, the pressure plate 30 is rotated so that the pressure plate 30 rotates toward the inside of the two power connection plates 5 , and then the screw thread penetrates the threaded hole 31 so that the end of the screw is against the circuit board, and the thermal protection varistor module is further fixed on the circuit board.

Embodiment 2:

Referring to Figure 7, comparative example 1 is another embodiment of the present invention, wherein screws 33 are symmetrically provided on both sides of the shell 1, one end of the screw 33 is threadedly penetrated through the upper surface of the shell 1, and the other end of the screw 33 is threadedly penetrated to the lower surface of the shell 1; according to the thickness of the circuit board, the screw 33 is rotated so that the circuit board squeezes the elastic plate 20, which helps the other end of the elastic plate 20 to effectively stick to the welding hole position of the circuit board.

The other end of the screw rod 33 is fixedly connected to a rubber pad 34 . The rubber pad 34 is provided to prevent the other end of the screw rod 33 from scratching and damaging the surface of the circuit board during rotation, thereby preventing the circuit board from short-circuiting or breaking.

Working principle: In the present invention, the lower surface of the shell 1 is attached to the surface of the circuit board, and the circuit board squeezes the push rod 3 into the guide tube 9. The temperature of the conductive plate 2 and the connecting plate 4 rises in the overloaded circuit, and the low-melting-point welding point between the conductive plate 2 and the socket 8 melts. The low-melting-point welding point is made of pollution-free metal materials, such as materials that do not contain lead or cadmium, and its melting temperature is between 100°C and 165°C. The conductive plate 2 and the socket 8 lose their fixed connection force. At the same time, under the upward push of the spring 10 in the guide tube 9, the socket 8 on the connecting plate 4 is separated from one end of the conductive plate 2, and the socket 7 on one side of the lower surface of the connecting plate 4 is separated from the other power connection pin 6 of the packaged varistor block 001. At this time, the packaged varistor block 001 and the conductive plate 2 are separated. The electric plate 2 is disconnected, and the circuit is in a disconnected state, realizing the function of protecting the circuit; the thermal protection varistor module designed by the present invention, the connecting plate 4 and the conductive plate 2 are directly temperature-raising components, so that the low-melting-point welding point is melted by heat, and the guide tube 9 and the push rod 3 are indirectly radiated and heated. At the same time, the guide tube 9 and the push rod 3 are made of some high-temperature resistant insulating materials, such as liquid crystal polymer materials, which can withstand a temperature of up to 315°C. Even at 200°C, only slight deformation will occur, which will not affect the sliding connection between the push rod 3 and the guide tube 9, ensuring the separation between the connecting plate 4 and the conductive plate 2, and at the same time, it can also prevent part of the heat on the connecting plate 4 from being transferred to the spring 10, which is also a protection for the elasticity of the spring 10;

The two guide tubes 9 are placed on the top of the connecting plate 4, and the socket 7 on one side of the lower surface of the connecting plate 4 is connected to another electrical connection pin 6 of the packaged varistor block 001. When the electrical connection pin 6 is separated from the socket, there will be sliding friction, which will affect the vertical upward and smooth movement of the connecting plate 4, causing the connecting plate 4 to be skewed, and the resistance of the socket 7 on one side of the lower surface of the connecting plate 4 to be separated from the electrical connection pin 6 increases, and the socket 8 is not smooth enough to be separated from the conductive plate 2. For this reason, the upward movement of the connecting plate 4 is balanced, and a balancing plate 12 is set on the conductive plate 2, so that the two ends of the connecting plate 4 are evenly stressed, and the connecting plate 4 moves upward steadily and smoothly, thereby ensuring the power-off protection performance of the thermal protection varistor module;

A metal plate 14 is fixedly connected to the upper surface of the connecting plate 4; even if the spring 10 in the guide tube 9 is squeezed for a long time or is in a heated state for a long time, and the spring 10 loses some elasticity, the metal plate 14 can be adsorbed by the magnetic plate 13 to drive the connecting plate 4 to move upward; the metal plate 14 is an iron metal plate 14, which is fixed to the connecting plate 4. After the low-melting-point welding point melts, the magnetic plate 13 adsorbs the metal plate 14, drives the connecting plate 4 to move upward and be placed in the placement groove, and realizes the power-off thermal protection function, that is, the connecting plate 4 is pushed up by the push rod 3 to separate from the conductive plate 2, and is adsorbed by the magnetic plate 13 to separate from the protection, or both are separated from the power-off protection at the same time;

The vertical plate 16 is provided to guide the movement of the connecting plate 4 so that it moves smoothly along the slide groove toward the placement groove, further ensuring the smooth movement of the connecting plate 4. At the same time, the guide rod 15 is restricted in the slide groove. When the thermal protection varistor module is powered off, the housing 1 is disassembled later to reset the connecting plate 4. At this time, the guide rod 15 can assist the socket 8 to align with the conductive plate 2 for welding, ensuring the electrical connection of the effective conductive part, and facilitating the operator to weld the two.

The power board 5 is inserted into the welding hole on the circuit board, and then the solder is melted and welded. Generally, there are manual welding and machine welding. The quality of machine welding is better than that of manual welding. However, when manual welding is performed for a long time, it is inevitable that there will be problems of empty welding or cold welding, which will make it difficult for the power board 5 to be attached to the circuit board. When the machine or equipment is in operation, it drives the circuit board to vibrate at a high frequency. In severe cases, the power board 5 with empty welding or cold welding will be vibrated out of the welding hole. For this reason, an elastic plate 20 is provided on the power board 5. In the initial state, the corner position of the elastic plate 20 is welded to the inner corner position of the recess 17. When the power board 5 is welded to the circuit board, an electric soldering iron is used to weld the inner corner position of the recess 17. The solder melts, and the elastic plate 20 is in its own elastic shape. The other end of the elastic plate 20 is attached to the circuit board. The elastic plate 20 acts as a conductive sheet, connecting the welding hole and the power board 5. Even if there is an empty solder joint or a cold solder joint, the power board 5 and the welding hole can be powered. The connection between the connecting column 21 and the notch 19 makes it convenient to assemble the elastic plate 20 and the power board 5. The limit hole 23 and the limit column 25 make the elasticity of the elastic plate 20 effectively act on the circuit board, ensuring the elasticity of the elastic plate 20, and the thermal protection varistor module can be effectively stabilized on the circuit board. The other end of the elastic plate 20 is attached to the circuit board, and then the power board 5 is soldered to the welding hole position by soldering.

When the elastic plate 20 is welded to the concave portion 17, the end of the electric soldering iron and the end of the welding rod extend to the through hole 27, and the solder melts and solidifies, which facilitates the melting of the solder to flow to the inner corner of the concave portion 17, effectively welding and fixing the elastic plate 20;

When the elastic plate 20 is separated from the recess 17, the residual molten solder on the elastic plate 20 splashes to the surrounding area at the moment when the elastic plate 20 swings, which may easily cause a short circuit in the circuit board. For this purpose, a baffle 28 is provided. At the moment when the elastic plate 20 is separated from the recess 17, the baffle 28 blocks the molten solder in the elastic plate 20 to prevent the solder from splashing and causing a short circuit in the components on the circuit board; after the power connection board 5 is welded, the pressing plate 30 is rotated so that the pressing plate 30 rotates toward the inside of the two power connection boards 5, and then the screw thread penetrates the threaded hole 31 so that the end of the screw is against the circuit board, thereby further fixing the thermal protection varistor module on the circuit board.

In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the scope of protection of the present invention.

The basic principles, main features and advantages of the present invention are shown and described above. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims (9)

1. A thermal protection varistor module comprising a packaged varistor block (001), characterized in that: the device also comprises a shell (1) and a thermal protection unit arranged in the shell (1); the thermal protection unit comprises a conductive plate (2), a push rod (3) and a connecting plate (4); the lower end face of the shell (1) is symmetrically provided with two power connection plates (5), the two power connection plates (5) extend into the shell (1), the inner end of each power connection plate (5) is fixedly connected with one power connection pin (6) of the encapsulation piezoresistor block (001), the other power connection pin (6) of the encapsulation piezoresistor block (001) vertically extends upwards and is embedded into a jack I (7) at one side of the lower surface of the connecting plate (4), a jack (8) is arranged in the middle position of the lower surface of the connecting plate (4), one end of a conductive plate (2) is welded at a low melting point in the jack (8), the other end of the conductive plate (2) is vertically fixedly connected with the inner end of the other power connection plate (5), and a through hole is formed in the middle horizontal position of the conductive plate (2); guide pipes (9) are symmetrically arranged on the lower surface of the connecting plate (4), the guide pipes (9) are connected with one end of the push rod (3) in a sliding mode through springs (10), the other end of one push rod (3) vertically penetrates through the through hole and extends out of the shell (1), and the other push rod (3) vertically extends out of the shell (1);

The other side of the lower surface of the connecting plate (4) is provided with a second jack (11), a balance plate (12) is arranged in the second jack (11), and the balance plate (12) is vertically fixedly connected to the middle horizontal surface of the conducting plate (2).

2. The thermal protection varistor module of claim 1, wherein: a placing groove is formed in the middle of the inner top surface of the shell (1), and a magnetic plate (13) is fixedly connected in the placing groove; an iron metal plate (14) is fixedly connected to the upper surface of the connecting plate (4).

3. A thermally protected piezoresistor module as set forth in claim 2 wherein: guide rods (15) are symmetrically and fixedly connected to two ends of the connecting plate (4); the top surface symmetry is equipped with riser (16) in casing (1), sets up the spout along its length direction on riser (16), guide bar (15) sliding connection in the spout.

4. The thermal protection varistor module of claim 1, wherein: a concave part (17) is formed in the middle position of two sides of each power receiving plate (5), a through fixing hole (18) is formed in the upper edge of each concave part (17), a notch (19) is formed in one side of each fixing hole (18), and an elastic plate (20) is arranged in each concave part (17); the elastic plate (20) is L-shaped, one end of the elastic plate (20) is fixedly connected with a connecting column (21), the connecting column (21) is embedded in the fixing hole (18), the elastic plate (20) is embedded in the notch (19), and the corner position of the elastic plate (20) is welded at the inner corner of the concave part (17); a notch (22) is symmetrically formed at the edge of one hole of the fixed hole (18), and a limit hole (23) is formed in the inner surface of the notch (22); one end of the connecting column (21) is provided with a convex part (24), the shape of the convex part (24) is matched with that of the notch (22), the end face of the convex part (24) is provided with a limit column (25), the limit column (25) points to the other end of the connecting column (21), the convex part (24) is embedded in the notch (22), and the limit column (25) is embedded in the limit hole (23).

5. The thermal protection varistor module of claim 4, wherein: the inner corner surface of the concave part (17) is provided with a groove (26), and the corner position of the elastic plate (20) is provided with a through hole (27).

6. The thermal protection varistor module of claim 5, wherein: baffle plates (28) are symmetrically arranged at the corner positions of the elastic plate (20), and the baffle plates (28) are triangular and fixedly connected to the edge positions of the two sides of the elastic plate (20).

7. The thermal protection varistor module of claim 4, wherein: the outer end of each power receiving plate (5) is provided with a rotary groove (29), a pressing plate (30) is arranged in the rotary groove (29), rotary holes (32) are formed in two sides in the rotary groove (29), the rotary groove (29) is internally provided with the pressing plate (30), the middle position of the pressing plate (30) is provided with a threaded hole (31), two sides of one end of the pressing plate (30) are fixedly connected with rotary pins, and the rotary pins are tightly connected in the rotary holes (32) in a rotary mode.

8. A thermally protected piezoresistor module as set forth in claim 3 wherein: screw rods (33) are symmetrically arranged on two sides in the shell (1), one end thread of each screw rod (33) penetrates through the upper surface of the shell (1), and the other end thread of each screw rod (33) penetrates through the lower surface of the shell (1).

9. The thermal protection varistor module of claim 8, wherein: the other end of the screw rod (33) is fixedly connected with a rubber pad (34).