Surge protector

Abstract

The present invention provides a surge protector, comprising a housing, a micro switch, a support frame, a varistor, a discharge tube, a connecting piece, a PCB board, a spring and a sliding piece; the varistor, the connecting piece and the discharge tube are conductively connected in sequence; the varistor and the connecting piece are welded by low-temperature solder; the micro switch, the varistor and the discharge tube are conductively connected to the PCB board; the varistor and the sliding piece are both arranged on the support frame; the spring can make the sliding piece abut against the connecting piece, and the sliding piece abuts against the micro switch under the elastic force of the spring; when the low-temperature solder melts, the spring can drive the sliding piece to separate from the micro switch. In the surge protector provided by the present invention, when a large voltage appears in the circuit, the temperature of the varistor rises, causing the low-temperature solder to melt, and the varistor and the connecting piece are disconnected under the drive of the sliding piece and the spring, so that the micro switch is switched, and the information of the failure of the surge protector is fed back to the background monitoring, thereby improving the safety failure sensitivity of the surge protector.

Description

Technical Field

[0001] The invention belongs to the technical field of overcurrent protection, and more specifically, relates to a surge protector. Background Art

[0002] In the power system, there are often excessive voltages caused by lightning induction, capacitive load connection, inductive load disconnection, etc. These excessive voltages can cause damage to electrical equipment. Surge protectors (SPDs, commonly known as lightning arresters) are usually connected in parallel with electrical equipment in the circuit, using the voltage-sensitive characteristics of SPDs to protect electrical equipment from various overvoltage damage, especially expensive, precise and uninterruptible electrical equipment, such as communication base station rooms, financial systems, stock trading systems, high-value electrical equipment and other electrical-related equipment and systems. The use of surge protectors can protect these equipment and systems from transient overvoltages caused by lightning or other reasons. However, all surge protectors need to be quickly, effectively and safely disconnected from the power grid when their own tolerance limits are reached, otherwise they often cause circuit short circuits and even fires, so the safety failure sensitivity of surge protectors is extremely important.

[0003] In the surge protector of the prior art, the varistor is connected to the thermal fuse. When the voltage in the circuit is too large, the temperature of the varistor rises until it reaches the melting point of the thermal fuse, and it takes a while before the thermal fuse can be disconnected. The process of the thermal fuse melting often takes several seconds, which makes the surge protector less sensitive to safely disconnect from the power grid when encountering extreme situations. The varistor is often short-circuited due to being disconnected from the power grid for a long time, thus catching fire and even causing a fire. Summary of the invention

[0004] The object of the present invention is to provide a surge protector to solve the technical problem of low sensitivity of the surge protector in safely disconnecting from the power grid in the prior art.

[0005] To achieve the above object, the technical solution adopted by the present invention is: to provide a surge protector, including a housing, a micro switch, a support frame, a varistor, a discharge tube, a connecting piece, a PCB board, a spring and a sliding member;

[0006] The PCB board is arranged in the housing;

[0007] The varistor, the connecting piece and the discharge tube are conductively connected in sequence;

[0008] The varistor and the connecting piece are welded by low-temperature soldering;

[0009] The micro switch, the varistor and the discharge tube are all conductively connected to the PCB board;

[0010] The varistor and the sliding member are both arranged on the supporting frame;

[0011] The spring is arranged between the support frame and the sliding member, so that the sliding member abuts against the connecting piece, and under the elastic force of the spring, the sliding member abuts against the micro switch;

[0012] When the low-temperature solder melts, the spring can drive the sliding member to separate from the micro switch.

[0013] Furthermore, the support frame includes an isolation plate, and the number of the varistors is two, and the two varistors are respectively arranged on both sides of the isolation plate.

[0014] Furthermore, a guide column is provided on the support frame, and the spring is sleeved on the guide column.

[0015] Furthermore, the sliding member is provided with a sliding hole, and the guide column passes through the sliding hole.

[0016] Furthermore, the support frame is also provided with an avoidance position, and the spring is arranged at the avoidance position;

[0017] The support frame comprises a mounting groove, the guide column is fixedly arranged on the groove wall of the mounting groove, and the micro switch is arranged in the mounting groove.

[0018] Furthermore, the support frame is provided with a flange, and the flange shields the varistor to physically isolate the varistor from the discharge tube, the PCB board and the micro switch.

[0019] Furthermore, the support frame is provided with a fixed slider, the sliding member is provided with a sliding groove, and the sliding groove is slidably arranged on the fixed slider.

[0020] Furthermore, the housing is provided with an observation hole, the sliding member is provided with a marking area, and the marking area is provided with at least two different colors;

[0021] When the low temperature solder melts, the spring can push the sliding member to move so that the color change of the marking area can be observed through the observation hole.

[0022] Furthermore, the support frame is fixedly connected to the PCB board.

[0023] Furthermore, the shell includes an upper shell and a lower shell covering the upper shell.

[0024] The surge protector provided by the present invention has the following beneficial effects: compared with the prior art, the PCB board of the surge protector of the present invention is arranged in a shell so that the PCB board is protected by the shell, and the shell can also prevent foreign objects from contacting the PCB board to avoid short circuit of the surge protector; the varistor, the connecting piece and the discharge tube are conductively connected in sequence, and the micro switch, the varistor and the discharge tube are conductively connected to the PCB board so that the micro switch, the varistor, the connecting piece and the discharge tube are conductively connected to the PCB board, thereby forming a protection circuit; the support frame is used to support the varistor and the sliding member; the spring is arranged between the support frame and the sliding member, and can drive the sliding member to abut against the connecting piece, and under the elastic force of the spring, the sliding member abuts against the micro switch to maintain a state of the micro switch, and the background monitoring information shows that the surge protector is normal; when struck by lightning and a large voltage appears in the circuit, the varistor and the discharge tube are both turned on, and the varistor in the circuit generates heat and accumulates heat to melt the low-temperature solder connecting the varistor and the connecting piece, and in the process of melting the low-temperature solder, the spring drives the sliding member to abut against the connecting piece When a certain external force is applied to the connecting piece, the sliding piece will accelerate the disconnection of the connecting piece from the pin of the varistor to reduce the time from degradation to disconnection between the varistor and the connecting piece. After the varistor is disconnected from the connecting piece, the varistor is safely disconnected from the power grid to avoid fire. At the same time, since the sliding piece loses its restraint, the spring will drive the sliding piece to move and disengage from the micro switch to drive the micro switch to change state, and transmit the information of the surge protector failure to the user so that the user can handle it in time. The mechanical movement of the sliding piece driven by the spring, supplemented by the characteristics of the low-temperature solder melting due to the heat of the varistor under overvoltage conditions, only the low-temperature solder needs to be initially close to the melting point. Under the external force of the sliding piece, the connecting piece can be disconnected from the varistor and the electrical safety distance is opened. The temperature fuse will not be disconnected until the temperature reaches the melting point for a period of time, which takes a long time, and the temperature fuse cannot effectively prevent current arcing due to its small disconnection distance. Compared with the traditional solution using a temperature fuse, this new solution has a short response time when a fault occurs, high sensitivity, and no current arcing. It is safe and reliable, and has great advantages. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0026] Figure 1 A schematic diagram of the structure of a surge protector provided by an embodiment of the present invention;

[0027] Figure 2 for Figure 1The exploded structure diagram of the surge protector shown;

[0028] Figure 3 for Figure 2 A magnified view of the middle support frame;

[0029] Figure 4 for Figure 2 An enlarged view of the middle sliding member;

[0030] Figure 5 for Figure 2 Assembly diagram of some structures;

[0031] Figure 6 for Figure 2 Assembly diagram of some structures.

[0032] Among them, the reference numerals in the figure are:

[0033] 1. Shell; 11. Upper shell; 111. Observation hole; 12. Lower shell; 2. Support frame; 21. Guide column; 22. Avoidance position; 23. Flanging; 24. Fixed slider; 25. Isolation plate; 26. Mounting slot; 3. Micro switch; 4. Varistor; 5. Discharge tube; 6. Connecting piece; 7. PCB board; 8. Spring; 9. Sliding part; 91. Sliding hole; 92. Sliding slot; 93. Marking area. DETAILED DESCRIPTION

[0034] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0035] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0036] It should be understood that the orientation or position relationship indicated by terms such as "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0037] See also Figure 1 , Figure 2 , Figure 5 and Figure 6 The surge protector provided by the present invention is now described. The surge protector comprises a housing 1, a micro switch 3, a support frame 2, a varistor 4, a discharge tube 5, a connector 6, a PCB board 7, a spring 8 and a sliding member 9;

[0038] The PCB board 7 is arranged in the housing 1;

[0039] The varistor 4, the connecting piece 6 and the discharge tube 5 are conductively connected in sequence;

[0040] The varistor 4 and the connecting piece 6 are soldered by low temperature soldering;

[0041] The micro switch 3, the varistor 4 and the discharge tube 5 are all conductively connected to the PCB board 7;

[0042] The varistor 4 and the sliding member 9 are both arranged on the support frame 2;

[0043] The spring 8 is arranged between the support frame 2 and the sliding member 9, so that the sliding member 9 abuts against the connecting piece 6. Under the elastic force of the spring 8, the sliding member 9 abuts against the micro switch 3;

[0044] When the low-temperature solder melts, the spring 8 can drive the sliding member 9 to separate from the micro switch 3 .

[0045] Compared with the prior art, the surge protector provided by the present invention has a PCB board 7 arranged in a housing 1 so as to protect the PCB board 7 through the housing 1, and the housing 1 can also prevent foreign objects from contacting the PCB board 7 to avoid a short circuit of the surge protector; the varistor 4, the connecting piece 6 and the discharge tube 5 are conductively connected in sequence, and the micro switch 3, the varistor 4 and the discharge tube 5 are conductively connected to the PCB board 7 so as to conductively connect the micro switch 3, the varistor 4, the connecting piece 6 and the discharge tube 5 to the PCB board 7, thereby forming a protection circuit and a remote signaling state conversion circuit; the support frame 2 is used to support the varistor 4 and the sliding member 9; the spring 8 is arranged on the support frame 2; the varistor 4 and the sliding member 9 are connected to the PCB board 7; the spring 8 is arranged on the support frame 2; the varistor 4 and the sliding member 9 are connected to the PCB board 7; the varistor 4 and the connecting piece 6 are connected to the discharge tube 5; the varistor 4 and the discharge tube 5 are conductively ... sliding member 9 are connected to the PCB board 7; the varistor 4 and the connecting piece 6 are connected to the discharge tube 5; the varistor 4 and the connecting piece 6 are connected to the discharge tube 5; the varistor 4 and the connecting piece 6 are connected to the discharge tube 5; the varistor 4 and the connecting piece 6 are connected to the discharge tube 5; the varistor The support frame 2 and the sliding member 9 are connected to each other, and the sliding member 9 can be driven to abut against the connecting piece 6. Under the elastic force of the spring 8, the sliding member 9 abuts against the micro switch 3. At this time, the micro switch 3 is in a transition state, and the three pins form two states of normally open and normally closed. When the surge protector is struck by lightning beyond its own tolerance or an abnormal overvoltage occurs, the varistor 4 and the discharge tube 5 are both turned on, and the varistor 4 in the circuit generates heat and accumulates heat to melt the low-temperature solder connecting the varistor 4 and the connecting piece 6. In the process of melting the low-temperature solder, the spring 8 drives the sliding member 9 to abut against the connecting piece 6, giving the connecting piece 6 a certain external Force, so the sliding member 9 will accelerate the disconnection of the connecting piece 6 and the varistor 4 to reduce the time from degradation to disconnection of the varistor 4 and the connecting piece 6. After the varistor 4 and the connecting piece 6 are disconnected, since the sliding member 9 loses its restraint, the spring 8 will drive the sliding member 9 to move and disengage from the micro switch 3, causing the varistor 4 to be safely disconnected from the power grid. At the same time, the micro switch 3 is converted, and the original open circuit becomes a closed short circuit, and the original closed short circuit is converted to an open circuit. This conversion will convey the corresponding fault information to the user so that the user can handle it in time. The mechanical movement of the sliding member 9 driven by the spring 8 can shorten the time from degradation of the connecting piece 6 and the varistor 4. To the disconnection time, this new scheme improves the sensitivity of the surge protector to safety failure; when the low-temperature solder melts, the connection strength between the connecting piece 6 and the varistor 4 is reduced, and the restraining effect on the sliding member 9 is reduced, so the spring 8 drives the sliding member 9 to move to further separate the varistor 4 and the connecting piece 6, increasing the air gap between the varistor 4 and the connecting piece 6, avoiding the arc caused by the conductive gap between the varistor 4 and the connecting piece 6 being too short, and avoiding the surge protector catching fire due to the arc, thereby improving the safety performance of the surge protector; the surge protector provided by the present invention is particularly suitable for the third-level lightning protection of the power supply.

[0046] Specifically, the varistor 4 is a voltage sensitive device.

[0047] Specifically, one pin of the varistor 4 is welded to the PCB board 7 , and the other pin is welded to the connecting piece 6 .

[0048] The applicant found that the existing temperature fuse is made of low-melting-point metal in a very small insulating shell. The heat generated by the varistor 4 needs to pass through the insulating shell to reach the low-melting-point metal, thereby increasing the heat transfer time and the melting time of the temperature fuse. The varistor 4 and the connecting piece 6 in the embodiment of the present invention are welded by low-temperature solder. The heat generated by the varistor 4 can directly reach the low-temperature solder. Compared with the existing temperature fuse, the melting of the low-temperature solder in the embodiment of the present invention, to be precise, has not yet melted, but has just begun to deteriorate and is close to the melting state. Obviously, this time will be shorter than the time it takes for the temperature fuse to be fully melted before it can be disconnected. It only needs to be close to the melting point of the low-temperature solder. Under the external force of the spring 8 and the sliding member 9, the connecting piece 6 will quickly disconnect from the varistor 4, so the surge protector has a higher safety failure sensitivity.

[0049] Specifically, the micro switch 3 is a normally open and normally closed switch. When the sliding member 9 abuts against the micro switch 3 and leaves the micro switch 3, the micro switch 3 switches, and the original open circuit becomes a closed short circuit, and the original closed short circuit is converted to an open circuit.

[0050] For further information, see Figure 3 , Figure 5 and Figure 6 As a specific embodiment of the surge protector provided by the present invention, the support frame 2 includes an isolation plate 25, and two varistors 4 are provided. The two varistors 4 are respectively arranged on both sides of the isolation plate 25. At this time, the conductive connections between the varistors 4 and the PCB board 7 and the connecting piece 6 are not polarity-specific, which is convenient for quickly connecting the varistors 4 to the circuit, thereby improving the assembly efficiency of the surge protector; the isolation plate 25 can physically isolate the two varistors 4 to prevent the two varistors 4 from being short-circuited or discharged close together, so as to damage the surge protector, thereby improving the stability of the surge protector.

[0051] For further information, see Figure 3 and Figure 5 As a specific embodiment of the surge protector provided by the present invention, a guide column 21 is provided on the support frame 2, and the spring 8 is sleeved on the guide column 21 to ensure that the spring 8 can drive the sliding member 9 to move in the positive direction, and avoid the spring 8 from tilting, resulting in the spring 8 driving the sliding member 9 to move. The force produces a large component force, causing the spring 8 to fail to drive the sliding member 9 to move to the maximum extent, thereby increasing the reaction time of the micro switch 3 and the time from degradation to disconnection of the varistor 4 and the connecting piece 6. The guide column 21 can also limit the spring 8 from being out of position.

[0052] For further information, see Figure 4 and Figure 5As a specific embodiment of the surge protector provided by the present invention, a sliding hole 91 is provided on the sliding member 9, and the guide column 21 passes through the sliding hole 91, and the spring 8 can be limited by the support frame 2 and the sliding member 9 to prevent the spring 8 from detaching from the guide column 21 from the gap between the guide column 21 and the sliding member 9; the sliding hole 91 on the sliding member 9 can prevent the guide column 21 from supporting the sliding member 9 and interfering with the movement of the sliding member 9.

[0053] For further information, see Figure 3 , Figure 5 and Figure 6 As a specific embodiment of the surge protector provided by the present invention, an avoidance position 22 is also provided on the support frame 2, and the spring 8 is arranged at the avoidance position 22, so that the structure of the spring 8, the sliding member 9, the micro switch 3 and the support frame 2 is more compact, reducing the space occupied by the spring 8, the sliding member 9, the micro switch 3 and the support frame 2 after assembly, thereby reducing the volume of the surge protector.

[0054] For further information, see Figure 2 , Figure 3 and Figure 5 As a specific embodiment of the surge protector provided by the present invention, the support frame 2 includes a mounting groove 26, a guide column 21 is fixedly arranged on the groove wall of the mounting groove 26, and a micro switch 3 is arranged in the mounting groove 26 to limit the micro switch 3 to prevent the micro switch 3 from moving when the sliding member 9 abuts against the micro switch 3 and affecting the performance of the surge protector. At the same time, the sliding guide column 21 is arranged on the groove wall of the mounting groove 26, which can simplify the structure and reduce the volume of the support frame 2.

[0055] For further information, see Figure 3 and Figure 5 As a specific embodiment of the surge protector provided by the present invention, a flange 23 is provided on the support frame 2, and the flange 23 shields the varistor 4, so as to physically isolate the varistor 4 from the discharge tube 5, the PCB board 7 and the micro switch 3 through the flange 23, so as to prevent the varistor 4 from being short-circuited with them and damaging the surge protector.

[0056] For further information, see Figures 3 to 5 As a specific embodiment of the surge protector provided by the present invention, a fixed slider 24 is provided on the support frame 2, and a slide groove 92 is provided on the slide member 9. The slide groove 92 is slidably arranged on the fixed slider 24. The fixed slider 24 can guide the slide groove 92 so that the slide member 9 can positively abut or disengage from the micro switch 3, thereby shortening the reaction time of the micro switch 3 and the time from degradation to disconnection of the varistor 4 and the connecting piece 6. This new solution improves the sensitivity of the safety failure of the surge protector.

[0057] For further information, see Figure 1 , Figure 4 and Figure 5As a specific embodiment of the surge protector provided by the present invention, the housing 1 is provided with an observation hole 111, the sliding member 9 is provided with a marking area 93, the marking area 93 is provided with at least two different colors, and the color conversion is realized due to the movement of the sliding member 9;

[0058] When the low-temperature solder melts, the spring 8 can push the sliding part 9 to move so that the color change of the identification area 93 can be viewed through the observation hole 111, so that the user can judge whether the connecting piece 6 and the varistor 4 are disconnected by the color change of the identification area 93 in the observation hole 111. If the user can see the color indicating that the fuse is not blown on the identification area 93 through the observation hole 111, it means that the connecting piece 6 and the varistor 4 are not disconnected, and the surge protector can still work normally; if the user can see the color indicating that the fuse is blown on the identification area 93 through the observation hole 111, it means that the connecting piece 6 and the varistor 4 are disconnected, so as to remind the user to replace it in time.

[0059] Specifically, see Figure 1 , an observation hole 111 is provided on the upper shell 11 .

[0060] For further information, see Figure 5 As a specific embodiment of the surge protector provided by the present invention, the support frame 2 is fixedly connected to the PCB board 7 to ensure the stability of the conductive connection between the varistor 4 arranged on the support frame 2 and the PCB board 7, improve the stability of the internal circuit of the surge protector, avoid the change of the spacing between the support member and the PCB board 7 and affect the stability of the conductive connection between the varistor 4 and the PCB board 7, and simplify the layout of the varistor 4, PCB board 7, support frame 2, discharge tube 5 and other components in the housing 1, thereby facilitating the assembly of the surge protector.

[0061] For further information, see Figure 1 and Figure 2 As a specific embodiment of the surge protector provided by the present invention, the housing 1 includes an upper housing 11 and a lower housing 12 covering the upper housing 11 to facilitate assembly of the surge protector.

[0062] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A surge protector, comprising a housing, a micro switch and a support frame, characterized in that: It also includes a varistor, a discharge tube, a connecting piece, a PCB board, a spring and a sliding part; The PCB board is arranged in the housing; The varistor, the connecting piece and the discharge tube are conductively connected in sequence; The varistor and the connecting piece are welded by low-temperature soldering; The micro switch, the varistor and the discharge tube are all conductively connected to the PCB board; The varistor and the sliding member are both arranged on the supporting frame; The spring is arranged between the support frame and the sliding member, so that the sliding member abuts against the connecting piece, and under the elastic force of the spring, the sliding member abuts against the micro switch; When the low-temperature solder melts, the spring can drive the sliding member to separate from the micro switch; The support frame includes an isolation plate, and the number of the piezoresistors is two, and the two piezoresistors are respectively arranged on both sides of the isolation plate; The support frame is provided with a guide column, and the spring is sleeved on the guide column; The support frame is provided with a flange, and the flange shields the varistor to physically isolate the varistor from the discharge tube, the PCB board and the micro switch; The support frame is provided with a fixed sliding block, the sliding member is provided with a sliding groove, and the sliding groove is slidably arranged on the fixed sliding block.

2. The surge protector according to claim 1, characterized in that: The sliding member is provided with a sliding hole, and the guide column passes through the sliding hole.

3. The surge protector according to claim 1, characterized in that: The support frame is also provided with an avoidance position, and the spring is arranged at the avoidance position; The support frame comprises a mounting groove, the guide column is fixedly arranged on the groove wall of the mounting groove, and the micro switch is arranged in the mounting groove.

4. The surge protector according to claim 1, characterized in that: The housing is provided with an observation hole, the sliding member is provided with a marking area, and the marking area is provided with at least two different colors; When the low temperature solder melts, the spring can push the sliding member to move so that the color change of the marking area can be observed through the observation hole.

5. The surge protector according to claim 1, characterized in that: The support frame is fixedly connected to the PCB board.

6. The surge protector according to claim 1, characterized in that: The housing includes an upper shell and a lower shell covering the upper shell.

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