Thermal protection type surge protector

Abstract

The utility model relates to a thermal protection type surge protector, which is characterized in that a piezoresistor chip is arranged in an inner mold, the inner mold is arranged in an inner box, and the inner box is arranged in a base; a first insertion piece is arranged on the edge of the inner mold, an elastic piece is arranged on the inner mold, and the elastic piece is connected with the first insertion piece; the piezoresistor chip is arranged in the inner mold, a first electrode is arranged on the piezoresistor chip, and the first electrode is connected with the elastic sheet; a second insertion piece is arranged on the inner mold, a second electrode is arranged on the piezoresistor chip, and the second electrode is connected with the second insertion piece; an indicating piece is arranged on the inner mold and is connected with the inner mold; one end of the indicating piece is connected with an indicating board, the indicating piece is connected with the first inserting piece through a tension spring, and the tension spring pulls the indicating piece to press the elastic piece. The third end of the indicating piece is located on the edge of the end, away from the tension spring, of the inner mold and tightly presses a micro-touch switch arranged in the base. According to the utility model, indication board prompting can be carried out, tripping electric signals can be transmitted, and a user can know the state timely and conveniently.

Description

Technical Field

[0001] The utility model relates to the technical field of surge protectors, and more particularly, to a thermal protection type surge protector. Background Art

[0002] A surge current protector SPD (Surge Protect ive Dev ice) is composed of one or more non-linear zinc oxide varistors connected in series / parallel, and is used to shunt the line surge current and suppress the line surge voltage, so as to protect the line electronic components from overvoltage and overcurrent damage.

[0003] The functional characteristic of the non-linear zinc oxide varistor is that within a certain specific voltage range, its body resistance is very high, equivalent to an insulator. When the voltage exceeds a certain threshold, the resistance drops rapidly, and its resistance change with voltage shows a non-linear characteristic.

[0004] The SPD containing zinc oxide resistors and the components to be protected are arranged in parallel in the line. When the normal operating voltage is applied, the zinc oxide varistor is in a high-resistance state, its leakage current is very small, and the power consumption is also low. When the line is struck by lightning or undergoes electromagnetic induction discharge, generating an instantaneous high voltage, the body resistance of the SPD connected in parallel at the front end of the line drops rapidly, and a large current is formed between the two lines of the line and discharged through the varistor, thus preventing other components from being damaged by overvoltage. The SPD can withstand the instantaneous overvoltage and recover instantaneously, but continuous long-term overvoltage will cause the temperature of the SPD body to rise continuously, which may cause an open fire.

[0005] In order to avoid the possibility of open fire damage caused by the failure of the SPD itself, it is necessary for the SPD to have a built-in thermal protection function. Currently, the existing SPDs with thermal protection functions are divided into two categories according to the breaking principle. One category is to use the characteristic of high-temperature fusing of a thermal fuse to cut off the electrical interconnection between the varistor and the line, thereby cutting off the current and preventing the temperature of the SPD body from rising continuously; the other category is to use mechanical force to separate the electrodes connected by low-temperature solder to form an air gap, thereby cutting off the current.

[0006] However, after the circuit of the surge current protector in the existing technical solution is broken, there is no clear prompt, which is not convenient for maintenance personnel to timely understand its status. Therefore, it is necessary to solve this problem. Summary of the Utility Model

[0007] The utility model aims to solve at least one of the above technical problems in the existing technology to a certain extent. For this reason, an object of the utility model is to provide a thermal protection type surge protector that can give an indication board prompt and transmit a tripping electrical signal, facilitating users to timely understand its status.

[0008] The technical solution of the present utility model to solve the above technical problems is as follows: A thermal protection type surge protector, comprising a varistor chip, an inner mold, an inner box and a base. The varistor chip is fixedly placed in the inner mold, the inner mold is fixedly placed in the inner box, and the inner box is detachably placed in the base;

[0009] One end edge of the inner mold is fixedly provided with a first insertion piece, and a shrapnel is arranged on the inner mold. One end of the shrapnel is fixedly connected to the first insertion piece; the varistor chip is fixedly placed in the inner mold, and a first electrode is arranged in the middle of the varistor chip. The first electrode passes through the end face of the inner mold and is fixedly connected to the end of the shrapnel through a first solder joint; the other end edge of the inner mold away from the first insertion piece is fixedly provided with a second insertion piece, and a second electrode is arranged on the edge of the varistor chip. The second electrode passes through the side wall of the inner mold and is fixedly connected to one end of the second insertion piece through a second solder joint. The other end of the second insertion piece is electrically connected to a wiring kit in the base, and the end of the first insertion piece is electrically connected to another wiring kit in the base;

[0010] An indicating member is arranged on the inner mold, and the indicating member is rotatably connected to the end face of the inner mold; one end of the indicating member is fixedly connected with an indicating plate, and the indicating plate is located at the edge of the inner mold. The end of the indicating member close to the indicating plate is connected to the end of the first insertion piece through a tension spring, and the tension spring pulls the other end of the indicating member to press the shrapnel; the third end of the indicating member is located at the edge of the inner mold away from the tension spring, and the third end of the indicating member presses a micro-touch switch arranged in the base.

[0011] The beneficial effect of the present utility model is: After the surge current protector is opened, it can give an indication by the indicating plate and transmit a tripping electrical signal, which is convenient for users to timely understand its state.

[0012] On the basis of the above technical solution, the present utility model can also be improved as follows.

[0013] Further, an indicating window is arranged on the inner box corresponding to the indicating plate.

[0014] The beneficial effect of adopting the above further solution is: The indicating window is convenient for users to timely understand the state of the indicating plate.

[0015] Further, a wiring terminal is fixedly arranged on the side wall of the base away from the inner box, and the wiring terminal is connected to the micro-touch switch through a wire.

[0016] The beneficial effect of adopting the above further solution is: The wiring terminal is convenient for connecting with an external circuit and transmitting the signal at the micro-touch switch to the outside.

[0017] Further, a positioning plug extending out of the inner box is fixedly arranged on a side wall of one end of the inner mold close to the base. A positioning hole is arranged on the base corresponding to the positioning plug, and a positioning ring is fixedly arranged at the positioning hole. The positioning plug can penetrate through the positioning ring and extend into the positioning hole.

[0018] The beneficial effect of adopting the above further scheme is that the positioning plug and the positioning ring are used to facilitate the loading, unloading and maintenance of the inner box and the base.

[0019] Further, a buckle is fixedly arranged on a side wall of one end of the base far from the inner box. A spring is arranged inside the buckle. One end of the spring abuts against the inner wall of the buckle, and the other end abuts against the base.

[0020] The beneficial effect of adopting the above further scheme is that the buckle and the spring cooperate to realize the installation of the base on a 35mm DIN guide rail. Description of the Drawings

[0021] Figure 1 is a front view of a thermal protection type surge protector of the present utility model;

[0022] Figure 2 is a first structural split schematic diagram of a thermal protection type surge protector of the present utility model;

[0023] Figure 3 is a second structural split schematic diagram of a thermal protection type surge protector of the present utility model.

[0024] In the drawings, the list of components represented by each reference numeral is as follows:

[0025] 1, varistor chip; 2, inner mold; 3, inner box; 4, base; 5, first insertion piece; 6, elastic piece; 7, first electrode; 8, second insertion piece; 9, second electrode; 10, wiring kit; 11, indicating piece; 12, indicating plate; 13, tension spring; 14, micro-touch switch; 15, indicating window; 16, wiring terminal; 17, positioning ring; 18, positioning plug; 19, buckle; 20, spring. Detailed Embodiments

[0026] The principles and features of the present utility model will be described below with reference to the drawings. The examples given are only for explaining the present utility model and are not intended to limit the scope of the present utility model.

[0027] As Figures 1 to 3 shown, a thermal protection type surge protector includes a varistor chip 1, an inner mold 2, an inner box 3 and a base 4. The varistor chip 1 is fixedly placed in the inner mold 2, the inner mold 2 is fixedly placed in the inner box 3, and the inner box 3 is detachably placed in the base 4;

[0028] One end edge of the inner mold 2 is fixedly provided with a first insertion piece 5. A shrapnel 6 is arranged on the inner mold 2, and one end of the shrapnel 6 is fixedly connected to the first insertion piece 5. The varistor chip 1 is fixedly placed in the inner mold 2. A first electrode 7 is arranged in the middle of the varistor chip 1. The first electrode 7 passes through the end face of the inner mold 2 and is fixedly connected to the end of the shrapnel 6 through a first solder joint. One end edge of the inner mold 2 away from the first insertion piece 5 is fixedly provided with a second insertion piece 8. A second electrode 9 is arranged at the edge of the varistor chip 1. The second electrode 9 passes through the side wall of the inner mold 2 and is fixedly connected to one end of the second insertion piece 8 through a second solder joint. The other end of the second insertion piece 8 is electrically connected to a wiring kit 10 in the base 4. The second insertion piece 8 is electrically connected to an external circuit through the wiring kit 10. The end of the first insertion piece 5 is electrically connected to another wiring kit 10 in the base 4. The first insertion piece 5 is electrically connected to an external circuit through the wiring kit 10.

[0029] An indicating piece 11 is arranged on the inner mold 2. The indicating piece 11 is rotatably connected to the end face of the inner mold 2. One end of the indicating piece 11 is fixedly connected to an indicating plate 12. The indicating plate 12 is located at the edge of the inner mold 2. The end of the indicating piece 11 close to the indicating plate 12 is connected to the end of the first insertion piece 5 through a tension spring 13. The tension spring 13 pulls the other end of the indicating piece 11 to press the shrapnel 6. The third end of the indicating piece 11 is located at one end edge of the inner mold 2 away from the tension spring 13. The third end of the indicating piece 11 presses a microswitch 14 arranged in the base 4.

[0030] In the specific application of this embodiment, when the voltage of the application circuit continuously exceeds the maximum voltage that the varistor chip 1 can withstand, the temperature of the varistor chip 1 continuously rises, and the heat is conducted to the first solder joint through the first electrode 7. The main component of the first solder joint is tin-bismuth alloy or tin-indium alloy, and the melting point is 80 to 160 °C. After the heat received by the first solder joint approaches its melting point temperature to higher than its melting point temperature, the first solder joint gradually softens into a liquid state and the strength decreases. When the strength of the first solder joint decreases to be insufficient to block the thrust of the indicating piece 11, the tension spring 13 generates a pulling force on the indicating piece 11, driving the indicating piece 11 to generate a thrust on the shrapnel 6. The first solder joint breaks, and the indicating piece 11 pushes the shrapnel 6 away from the first electrode 7 under the pulling force of the tension spring 13 to achieve a tripping action, thereby cutting off the circuit and avoiding the continuous temperature rise of the varistor chip 1 leading to a fire.

[0031] After the first soldering point operates, one end of the indicating member 11 is displaced under the pulling force of the tension spring 13. The indicating member 11 drives the indicating plate 12 to move, and the indicating plate 12 moves away from its original position, facilitating the user to visually understand that the first electrode 7 and the elastic piece 6 are disengaged. At the same time, the third end of the indicating member 11 is displaced, and the third end of the indicating member 11 releases the microswitch 14, and the microswitch 14 is turned on, facilitating the transmission of a signal to the outside, thereby realizing the output of a tripping electrical signal.

[0032] In this embodiment, after the surge current protector is opened, the indicating plate 12 can give a prompt and transmit a tripping electrical signal, facilitating the user to timely understand its state.

[0033] In the above embodiment, an indicating window 15 is provided at the position of the inner box 3 corresponding to the indicating plate 12.

[0034] In specific application, the indicating window 15 facilitates the observation of the indicating plate 12. When the indicating plate 12 cannot be seen through the indicating window 15, it indicates that the first electrode 7 and the elastic piece 6 are disengaged, facilitating the user to timely understand the state of the indicating plate 12.

[0035] In the above embodiment, a wiring terminal 16 is fixedly provided on the side wall of one end of the base 4 away from the inner box 3, and the wiring terminal 16 is connected to the microswitch 14 through a wire.

[0036] In specific application, the wiring terminal 16 facilitates the connection with an external circuit and transmits the signal at the microswitch 14 to the outside.

[0037] In the above embodiment, a positioning plug 18 extending out of the inner box 3 is fixedly provided on the side wall of one end of the inner mold 2 close to the base 4. A positioning hole is provided at the position of the base 4 corresponding to the positioning plug 18, and a positioning ring 17 is fixedly provided at the positioning hole. The positioning plug 18 can pass through the positioning ring 17 and extend into the positioning hole.

[0038] In specific application, when assembling the inner box 3 and the base 4, the positioning plug 18 is inserted into the positioning ring 17, facilitating the fixed connection of the inner box 3 and the base 4 and facilitating disassembly, loading, and maintenance.

[0039] In the above embodiment, a buckle 19 is fixedly provided on the side wall of one end of the base 4 away from the inner box 3. A spring 20 is provided inside the buckle 19. One end of the spring 20 abuts against the inner wall of the buckle 19, and the other end abuts against the base 4.

[0040] In specific application, the buckle 19 and the spring 20 cooperate to realize the 35mm D IN rail installation of the base 4.

[0041] The above are only the preferred embodiments of the present utility model, and are not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A thermal protection type surge protector, characterized in that: It includes a varistor chip (1), an inner mold (2), an inner box (3) and a base (4). The varistor chip (1) is fixedly placed in the inner mold (2), the inner mold (2) is fixedly placed in the inner box (3), and the inner box (3) is detachably placed in the base (4); One end edge of the inner mold (2) is fixedly provided with a first insertion piece (5), and a spring piece (6) is arranged on the inner mold (2). One end of the spring piece (6) is fixedly connected to the first insertion piece (5); the varistor chip (1) is fixedly placed in the inner mold (2), a first electrode (7) is arranged in the middle of the varistor chip (1), and the first electrode (7) passes through the end face of the inner mold (2) and is fixedly connected to the end of the spring piece (6) through a first solder joint; the other end edge of the inner mold (2) far from the first insertion piece (5) is fixedly provided with a second insertion piece (8), a second electrode (9) is arranged at the edge of the varistor chip (1), the second electrode (9) passes through the side wall of the inner mold (2) and is fixedly connected to one end of the second insertion piece (8) through a second solder joint, the other end of the second insertion piece (8) is electrically connected to a wiring kit (10) in the base (4), and the end of the first insertion piece (5) is electrically connected to another wiring kit (10) in the base (4); An indicating piece (11) is arranged on the inner mold (2), and the indicating piece (11) is rotatably connected to the end face of the inner mold (2); one end of the indicating piece (11) is fixedly connected with an indicating plate (12), the indicating plate (12) is at the edge of the inner mold (2), and the end of the indicating piece (11) close to the indicating plate (12) is connected to the end of the first insertion piece (5) through a tension spring (13), and the tension spring (13) pulls the other end of the indicating piece (11) to press against the spring piece (6); the third end of the indicating piece (11) is at the edge of the inner mold (2) far from the tension spring (13), and the third end of the indicating piece (11) presses against a micro-touch switch (14) arranged in the base (4).

2. The thermal protection type surge protector according to claim 1, characterized in that: An indicating window (15) is arranged on the inner box (3) corresponding to the indicating plate (12).

3. The thermal protection type surge protector according to claim 1, characterized in that: A wiring terminal (16) is fixedly arranged on the side wall of the base (4) far from the inner box (3), and the wiring terminal (16) is connected to the micro-touch switch (14) through a wire.

4. The thermal protection type surge protector according to claim 1, characterized in that: A positioning plug-in (18) extending out of the inner box (3) is fixedly arranged on the side wall of the inner mold (2) close to the base (4). A positioning hole is arranged on the base (4) corresponding to the positioning plug-in (18), and a positioning ring (17) is fixedly arranged at the positioning hole. The positioning plug-in (18) can pass through the positioning ring (17) and extend into the positioning hole.

5. The thermal protection type surge protector according to claim 1, wherein: A buckle (19) is fixedly arranged on the side wall of the base (4) far from the inner box (3), a spring (20) is arranged in the buckle (19), one end of the spring (20) touches the inner wall of the buckle (19), and the other end touches the base (4).

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