CN105206477A - Current overload protection switch with lightning protection function - Google Patents

Abstract

A current overload protection switch with lightning protection function is disclosed, which uses an overcurrent protection switch as a main body, a voltage overload protection device is skillfully built in the inner space of the overcurrent protection switch, and one of the lugs comprises an extension part extending out of the shell and an action part positioned in the shell; a voltage overload protection element which is composed of a piezoresistor and a temperature sensing column with insulation property and is arranged at one side of the action part in an attaching way; a spring, which is arranged on the other side of the action part and provides an elastic force to push towards the direction of the temperature sensing column; therefore, when the temperature of the piezoresistor rises to the melting temperature of the temperature sensing column instantly due to instant high voltage, the temperature sensing column is in direct and large-area contact and can achieve the heat conduction effect of being quicker and more closely combined, the temperature sensing column is melted instantly, so that the jacking force on the corresponding side of the spring disappears, the successful action can be ensured every time, and the power can be quickly cut off when the piezoresistor does not rise to high temperature, so that the effect of electricity safety is achieved.

Description

Current overload protection switch with lightning protection function

technical field

The invention relates to a current overload protection switch with lightning protection function, especially a current overload protection switch with a built-in voltage overload protection device. The temperature sensing column has direct and large-area contact to achieve faster and tighter The combined heat conduction effect can ensure the successful operation every time and the structure that the power can be cut off quickly before the high temperature is reached.

Background technique

Figures 1A and 1B disclose an existing overload protection switch 10, which generally includes: a housing 11 with a pressing block 12 at the upper end, and a first lug 12a and a second lug at the bottom. 12b and the third lug 12c, wherein the first lug 12a is provided with a double metal contact reed 13 and a first contact 131, and the upper part of the second lug 12b is provided with a contact with it relative to the first contact The second contact point 121; a linkage 14, one end of which is pivotally located at the bottom of the briquetting block 12, and the other end is linked to the free end of the double metal contact reed 13, which is driven by the pressing of the briquetting block 12 The first contact 131 on the double metal contact reed 13 contacts the second contact 121 to form a conduction (ON), and when the current is overloaded, the curvature of the double metal contact reed 13 occurs due to temperature rise deform, and make the first contact 131 separate from the second contact 121 to form an open circuit (OFF), so as to form a form of the current overload protection switch 10 . This type of patent is found in patents such as Taiwan Publication Nos. 540811, 367091, 320335, 262168, and 208384.

But check, above-mentioned existing overload protection switch 10, is the structure designed for current overload, but, for sudden situations such as surge or lightning strike, and cause voltage instant overload, there is no protection device for automatic circuit breaker (OFF), therefore It is easy to cause damage to electrical appliances or there is a risk of safety in use.

Therefore, in order to be safe in use, in many circuits, when the existing overload protection switch 10 is in use, a surge absorber (Metal Oxide Varistor) and a thermal fuse are connected in series with the main power supply in addition, so that Prevent damage caused by overvoltage.

As shown in Fig. 2A, Fig. 2B and Fig. 2C, it is an existing structural form of a thermal fuse, which is mainly placed in a casing 20 with an opening at one end, and a temperature sensing element 21 is placed at the tail end, and a baffle is covered. 22. Immediately insert a first long-distance spring 23, and then cover a stopper 24 and place the conductive sheet 25. The conductive sheet 25 is formed by a disc-shaped body on the ring edge to form several upward arc-shaped conductive strips. Claw pieces, use each claw piece to touch the conductive surface of the inner wall of the shell 20, and insert one end of the copper front guide rod 201 into the insulating inner bushing 27 made of ceramics, and it is fastened by the buckle ring 28 and exposes a In a small section, put a second long-distance spring 26 at one end of the inner bushing 27 and insert it into the housing 20, so that the front guide rod 201 and the second spring 26 are all against the body surface of the conductive sheet 25, and the conductive sheet 25 will Displace to the position where the left and right elastic forces of the first long-distance spring and the second long-distance spring are balanced, and then place an outer bushing 29 on the front guide rod 201 exposed outside the housing 10 and seal the opening of the housing 10 with an insulating adhesive , and at the same time let the inner bushing 27 and the outer bushing 29 be joined into one body, and finally one end of the rear guide rod 202 is fixedly connected to the other end of the outer casing 20 by riveting. The use form of this kind of thermal fuse is shown in Figure 2B and Figure 2C. The thermal fuse is connected to the power wire by using the front guide rod 201 and the rear guide rod 202. Conducted to the front guide rod 201 that is in contact with the conductive sheet 24 to make the power supply form a conductive state. When the ambient temperature is higher than the preset temperature, the temperature sensing element 21 will melt instantly, and at this time the first long-distance spring 23 will move toward the The temperature sensing element 21 stretches in the direction and pushes the copper sheet 22 to shift, so that the melted temperature sensing element 21 flows out from the edge of the copper sheet 22, and the balanced fixing force between the second long-distance spring 26 and the first long-distance spring 23 is affected. Destruction, so that the second spring 26 slides the conductive sheet 25 towards the temperature sensing element 21. Since the front guide rod 201 is fixed to the inner bushing 27 and cannot move, the displaced conductive sheet 25 is separated from the front guide rod 201. The non-contact state prevents the power supply from being transmitted to the rear guide rod 202 to form a power failure, so as to avoid damage to electrical products and achieve the effect of insurance. This type of patent is found in patents such as Taiwan Announcement No. 370479 and No. M395243.

But check, the above-mentioned existing overload protection switch 10 externally connects the thermal fuse 20 and the mode of the surge absorber (varistor) (MetalOxideVaristor), although the dual protection function of overcurrent and overvoltage can be achieved, but the external surge absorber and surge absorber Between thermal cutoffs, close-to-indirect heat conduction coating is required. The heat-resistant coating method and the size of the point or line contact surface between the tubular thermal cutoff and the planar surge absorber will affect whether it can respond quickly and after conduction failure. There is a risk of continuous heating, and the heat conduction shielding distance between the casing 20 and the casing 20 needs to be lengthened during welding to prevent the tubular thermal fuse casing 20 from overheating and melting and breaking the circuit in advance. Therefore, it is necessary to increase the space to respond, which will only increase the inconvenience of processing and assembly. Cause electrical product reliability and safety problems.

Fig. 2D is an existing anti-surge (lightning strike) circuit breaking method, which is to shrink the surge absorber 101 and the thermal fuse 102 by shrinking the heat shrinkable sleeve 103 or elastically tightening the elastic rubber ring to make the plane surge When the absorber 101 encounters a lightning strike, the temperature rises rapidly and reaches the middle temperature range but not the high temperature range, and the "fast" melting body that indirectly transfers heat to the tubular thermal fuse 102 acts in real time, causing the main power supply to be disconnected. However, if the surface contact is poor, the action time of interrupting the main power supply will be delayed due to the slow heat transfer, so that the temperature of the surge absorber 101 will continue to rise to a high temperature range, and the heat shrinkable sleeve 103 will rupture and lose the tight-bundle surge absorption The bundle force between the device 101 and the thermal fuse 102 stops the heat conduction, and the surge absorber 101 rises to a high temperature and melts and burns out. Because there is only point or line contact, sometimes the surface is dirty and there is poor contact, so that the thermal fuse 102 that controls the disconnection of the main power supply does not operate the disconnection function, and the surge absorber 101 rises to high temperature and burns. These two items are the difficulties that cannot ensure the reliability of quality control using this method.

Fig. 2E is another existing anti-surge (lightning strike) circuit breaking method, which uses an elastic rubber ring 103 to elastically tighten the surge absorber 101 and two elastic conductive contact pieces 104, so that the main power supply is contacted and conducted . When the surge receiver 101 encounters a lightning strike and heats up to a high temperature within microseconds, the elastic rubber ring 103 will fuse "slowly" at this time, so that the two elastic contact pieces 104 are elastically separated from the main power supply to form an open circuit. At this time, the elastic rubber ring 103 is burned due to the high temperature of the surge absorber 101, but because it is enclosed in a fireproof sealed space 100, it will eventually go out due to the exhaustion of air.

FIG. 2F discloses an anti-surge switch module applied to a power system. The switch module includes a power switch 105 , an insulating member 106 , a surge absorber 107 and a heat shrinkable tape 108 . The insulator 106 is inserted on the power switch 105; the surge absorber 107 is adjacent to the power switch 105; the heat shrinkable band 108 is connected with the surge absorber 107 and the insulator 106, and the heat shrinkable band 108 is used to absorb The temperature of the device 107 produces shrinkage; when the insulator 106 is in the initial state, it does not affect the switching of the power switch, and when the shrinkage of the heat shrinkable tape 108 is enough to drive the insulator to block the start of the power switch 105, the power switch 105 is off. state. This type of patent is found in TWI408717 (ie US Patent No. 8,643,462).

However, the above lightning protection and anti-surge structures are not only difficult to ensure quality, high temperature danger, and slow response, but also have the limitations of too large volume and too complicated components, so more space and assembly processes are required. It can only be implemented externally and independently of the switch, and cannot be built into the switch, so there is still room for improvement.

According to the third edition of UL1449 (2009.10), there is a new surge protector specification for TYPE4SPD-components. At the same time, the new version includes low voltage (below 1000V) arrester (LowVoltagesurgeArrestres) test. The name was changed from (TransientVoltageSurgeSuppressors) to (SurgeProtectiveDevices) to show the necessity of component integration and lightning protection (surgeArrestres) fast power-off

Therefore, consider how to build an overvoltage protection device into the overcurrent protection switch 10, and make the heat not need to be conducted indirectly through the thermal fuse shell, but directly transfer the heat to the temperature sensing body, and improve the conduction of the conduction surface Efficiency and ensuring that the actions can be successfully completed are the problems to be solved by the present invention.

Contents of the invention

The main technical problem to be solved by the present invention is to overcome the above-mentioned defects in the prior art and provide a current overload protection switch with lightning protection function. The switch is equipped with an overvoltage protection device at the same time to achieve the effect of electricity safety; its temperature sensing column has direct and large-area contact to achieve faster and tighter heat conduction, which ensures that it can operate successfully every time When the varistor does not rise to high temperature, it can quickly cut off the power to ensure the safety of use.

The technical solution adopted by the present invention to solve its technical problems is:

A current overload protection switch with lightning protection function, comprising: a casing, a pressure block is arranged at the upper end, and a first lug, a second lug and a third lug are respectively set at the bottom, wherein the The first connecting piece is provided with a double metal contact reed and the first contact point, and the second connecting piece is provided with a second contact point which can be contacted with respect to the first contact point above the second connecting piece; At the bottom of the pressing block, the other end links the free end of the double metal contact reed, and by pressing the pressing block, the first contact on the double metal contact reed is driven to contact the second contact to form a conduction ( ON), and when the current is overloaded, the curvature of the double metal contact reed is deformed due to the temperature rise, and the first contact is separated from the second contact to form an open circuit (OFF) to constitute a current overload The shape of the protection switch;

It is characterized in that: the second lug includes an extension part protruding from the outside of the housing, and an action part located in the housing, and the action part has an upper section for fixing the second contact, and an upper section connected to the upper section. An electrically connected middle plate having a first side and an opposite second side, and at least a portion of a second spring side of the middle plate is in detachable electrical contact with the extension Part; a voltage overload protection element, which is composed of a varistor and a temperature-sensing column, the varistor is formed into a sheet, and it has a first surface and an opposite second surface, the temperature-sensing column It is composed of a heat-sensitive substance that melts instantly when it reaches a predetermined temperature, and its bottom surface is attached to the second surface of the piezoresistor, and the first surface of the piezoresistor is attached to the bonding surface of the third lug, Form electrical contact, and make the front end of the temperature sensing column face the second spring side of the middle plate, and contact a part of the second side against the second side; a spring has a first end and an opposite first end Two ends, and the first end is arranged on the second side of the middle plate, and the second end abuts against the stop surface provided in the casing, so that the spring provides an elastic force toward the temperature-sensing column.

In this way, when the first contact and the second contact are in contact with each other (ON), and the temperature of the surge absorber rises higher than the default value instantaneously when an overvoltage is encountered, the temperature-sensing column is instantly melted, so that the spring on the corresponding side When the restraining force disappears, the seesaw is displaced, and the output terminals of the first wiring piece and the second wiring piece are forced to form an open circuit (OFF).

In a feasible embodiment, the upper part of the action part and the middle plate can form an L shape or a curved shape. In addition, a pivot hole can be provided at the L-shaped junction between the upper part of the action part and the middle plate, and a protruding shaft can be provided at the relative position of the housing for installation in the pivot hole, so that the action part presents a deflectable seesaw shape.

In another feasible embodiment, a third contact point and a fourth contact point are provided opposite to each other at the relative contact positions of the middle plate and the extension part.

And a preferred embodiment is to set the temperature-sensing column as a conical body with the largest bottom area and tapered toward the front end.

In addition, in a feasible embodiment, the first side of the middle plate of the action part is provided with a protruding elastic sheet for short-distance heat reduction in contact with the temperature-sensing column, and the elastic sheet is opposite to the temperature-sensing column The front end of the temperature sensing column is provided with a positioning body concave toward the second side for the front end of the temperature sensing column to be embedded and positioned.

Further, in a feasible embodiment, the front end of the temperature-sensing column is also provided with an insulating and heat-shielding cap.

With the help of the above-mentioned technical features, the present invention solves the lack of an external thermal fuse and surge absorber in the existing current overload protection switch. In the internal space of the general current overload protection switch, a voltage overload protection device is skillfully built in. When the current output is used as the second lug, its action part will quickly produce a displacement, so that the output end forms an open circuit structure, and the heat-generating piezoresistor and the temperature-sensing column that can be melted instantly can be directly and large-area contacted. Achieving a faster and tighter heat conduction effect can ensure that the operation can be successful every time and the power can be cut off quickly before the high temperature is reached. Therefore, in addition to the current overload protection function of the present invention, it further has both functions in the same switch. The overvoltage protection design has the functions of safe electricity use and convenient use in configuration.

The beneficial effect of the present invention is that, in addition to the original function of the current overload protection switch, it also has an overvoltage protection device in the same switch to achieve the effect of electricity safety; its temperature-sensing column has a direct and large-area Contact can achieve a faster and tighter heat conduction effect, which can ensure successful operation every time and can quickly cut off the power when the varistor does not rise to high temperature, so as to ensure the safety of use.

Description of drawings

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

FIG. 1A is a perspective view of an existing current overload protection switch.

FIG. 1B is a cross-sectional view of a conventional current overload protection switch.

Fig. 2A is an appearance diagram of a conventional thermal fuse.

FIG. 2B is a cross-sectional view of a conventional thermal cutoff (ON).

FIG. 2C is a cross-sectional view of a conventional thermal fuse disconnection (OFF).

Fig. 2D is a schematic diagram of an existing anti-surge (lightning strike) circuit breaking method.

FIG. 2E is a schematic diagram of another current circuit breaking method for preventing surge (lightning strike).

FIG. 2F is a schematic diagram of the anti-surge disconnection method of the existing TWI408717 (ie US Patent No. 8,643,462).

Fig. 3 is a structural cross-sectional view of a preferred embodiment of the present invention, which shows that the switch is in an OFF state.

FIG. 4 is a structural sectional view of a preferred embodiment of the present invention, which shows that the switch is in the ON state.

Fig. 5 is a diagram of the use state of the present invention, which shows that the sensing element dissolves instantaneously, and the action part is displaced to form an open circuit (OFF).

Fig. 6 is an exploded perspective view of main components of a preferred embodiment of the present invention.

Explanation of symbols in the figure:

30 current overload protection switch

31 shell

32 briquettes

33 linkage

34 stop surface

35 cam shaft

40 first lug

41 duplex metal contact reed

411 first contact

412 free end

50 second lug

50a extension

50b action department

51 upper section

511 second contact

512 pivot holes

52 action board

521 first side

522 second side

523 elastic sheet

524 positioning body

53 third contact

54 fourth contact

60 third lug

61 joint surface

70 voltage overload sensing element

71 varistor

711 first surface

712 second surface

713 wire

72 temperature column

721 Bottom

722 front end

73 Insulation and heat insulation cap

80 spring

81 first end

82 second end

Detailed ways

First, please refer to Figures 3 to 6, a preferred embodiment of the present invention includes: a housing 31, a pressing block 32 is provided at the upper end, and a first terminal piece 40 and a second terminal piece 40 are provided at the bottom end. 50 and the third lug 60, the first lug 40 is provided with a double metal contact reed 41 and the first contact 411, and the second lug 50 is provided with a can The second contact point 511 in contact with it; a linkage 33, one end of which is pivotally arranged at the bottom of the pressing block 32, and the other end links the free end 412 of the double metal contact reed 41, as shown in Figure 4, by The pressing of the briquetting block 32 drives the first contact 411 on the double metal contact reed 41 to contact the second contact 511 to form conduction (ON), and when the current is overloaded, the curvature of the contact reed 41 is caused by The temperature rises and deforms, and the first contact 411 is separated from the second contact 511 to form an open circuit (OFF), so as to form a current overload protection switch 30; repeat.

The feature of the present invention is that: under the structure of the current overload protection switch 30, in a feasible embodiment, the second lug 50 is set to include an extension 50a protruding from the housing 31 and a The inner action part 50b, and the action part 50b has an upper section 51 for fixing the second contact 511, and a middle section plate 52 electrically connected with the upper section, and the middle section plate 52 has a first side 521 and the second side 522 on the opposite side (as shown in FIG. 6 ), and at least a part of a second side 522 of the middle plate 52 is in detachable electrical contact with the extension portion 50a. In this embodiment, the upper portion 51 of the action portion 50b and the middle plate 52 form an L shape or a curved shape. And the upper part 51 of the action part 50b and the L-shaped connection of the middle plate 52 are provided with a pivot hole 512, and the housing 31 is provided with a protruding shaft 35 at the opposite position for the pivot hole 512 to be installed, so that the action part 50b presents a A deflectable seesaw.

A voltage overload sensing element 70 is composed of a piezoresistor 71 and a temperature sensing column 72. In this embodiment, the piezoresistor 71 is in the shape of a circular bare chip (that is, the surface is not coated with an insulating substance), But not limited thereto, it has a surge absorbing function, and converts the absorbed voltage into thermal temperature when the voltage is abnormal, but its principle and composition belong to the prior art, and will not be described in detail. The piezoresistor 71 has a first surface 711 and an opposite second surface 712, and the piezoresistor 71 is connected to the extension portion 50a of the second lug 50 by a wire 713, and the temperature sensing column 72 is formed by It is made of heat-sensitive substance that melts instantaneously when it reaches a predetermined temperature, and its bottom surface 721 is attached to the second surface 712 of the piezoresistor 71, and the first surface 711 of the piezoresistor 71 is attached to the third lug The bonding surface 61 of 60 forms an electrical contact, that is, its bottom surface is attached to the second surface 712 of the piezoresistor 71, and an adhesive medium is used to make it completely bonded and fluxed. Furthermore, the front end of the temperature sensing column 72 722 faces the second side 522 of the middle plate 52, and its purpose is to make the temperature-sensing column 72 directly or indirectly apply a force to the second side 522 of the middle plate 52, so that the middle plate is forced to The plate 52 is in electrical contact with the extension 50a.

In this embodiment, the temperature-sensing column 72 can be composed of non-metallic rosin (Resin) or agar (Agar)-type heat-sensitive substances, or fast-melting metal compounds such as metal Wood's fusible metal. (For example: metal compounds for general fuses), but not limited to this. Therefore, as long as the temperature rise of the surge absorber reaches the set temperature, and when the temperature of such substances does not rise to a high temperature, the conductive or non-conductive substances that will melt and cut off the power can be used. This compound has a fixed melting point and has a fast chain scission melting characteristic of plus or minus 1 degree C. And a preferred embodiment is to set the temperature-sensing column 72 so that the bottom surface 721 has the largest area and is tapered toward the front end 722, and its bottom surface 721 can use compatible materials as a fluxing adhesive, and its It is glued and fixed on the second surface 712 of the piezoresistor 71 to be integrated. Accordingly, the combination of the two is not only convenient for assembly in the housing 31, but the two are firmly bonded and have a large contact area, which is more conducive to heat conduction efficiency, that is, the piezoresistor 71 can quickly transfer heat to the temperature-sensing column 72, make it melt instantly, so just can reach the desired purpose of the present invention.

A spring 80, which has a first end and 81 an opposite second end 82, and the first end 81 is located on the second side 522 of the middle plate 52, and the second end 82 is against the housing The stop surface 34 provided in the inner portion 31 enables the spring 80 to provide an elastic force toward the temperature-sensing column 72 .

Moreover, since the spring 80 is disposed on the second side 522 of the middle plate 52 , it provides an elastic force to push against the direction of the temperature-sensing column 72 . And usually because the front end 722 of the temperature-sensing column 72 withstands the elastic piece 523 of the first side 521 of the middle plate 52, as shown in Figure 4, because the temperature-sensing column 72 is solid before melting, so the spring 80 appears to be held In the compressed state, the middle plate 52 can be kept in electrical contact with the extension portion 50a.

Thereby, as shown in FIG. 5, when the first contact 411 and the second contact 511 are in contact with each other (ON), and the temperature of the piezoresistor 71 rises instantaneously higher than the melting value of the temperature-sensing column 72 when encountering a high voltage, the temperature-sensing The column 72 is melted, so that the restraining force on the corresponding side of the spring 80 disappears, and then the actuating part 50b is displaced, forcing the output terminals of the first terminal piece 40 and the second terminal piece 50 to form an open circuit (OFF).

In addition, in a feasible embodiment, the first side 521 of the middle plate 52 of the action part 50b is provided with a protruding and short-distance elastic piece 523 in contact with the temperature-sensing column 72, and the elastic piece 523 is Relative to the front end 722 of the temperature-sensing post 72 , there is a positioning body 524 recessed toward the second side 522 (ie, toward the direction of the spring 80 ), for the front end 722 of the temperature-sensing post 72 to be inserted and positioned. In this embodiment, the elastic sheet 523 can be directly stamped from the surface of the middle plate 52, because it has elasticity and can be pressed by the front end 722 of the temperature sensing column 72; thereby, the second side 522 of the middle plate 52 can be in contact with The extension 50a ensures effective contact; but not limited thereto. That is to say, the surface of the middle plate 52 is not limited to stamping the elastic piece 523, the elastic piece 523 can also be replaced by a spring (not shown), or directly change the middle plate 52 into an elastic plate, or replace Spring sheet 523 or a spring (not shown in the figure), in the present embodiment, the purpose of this elastic sheet 523 is to provide an elastic space, it can make this middle plate 52 can contact this this extension part 50a effectively on the one hand, on the other hand It is convenient to install the temperature-sensing column 72 , otherwise, the length of the elastic piece 523 must be calculated accurately so that it can be just embedded between the piezoresistor 71 and the middle plate 52 . In addition, another function of the elastic sheet 523 can be used for heat insulation, so as to avoid the extended part 50a of the second terminal piece 50 protruding from the housing 31 and need to be welded for a long time, even though there are two contact points for thermal insulation. It may be possible that the temperature-sensing column 72 has not been used due to long-term welding, and the possibility of melting occurs. Of course, a feasible embodiment includes adding a tapered insulating heat-insulating cap 73 at the front end of the temperature-sensing column 72, so that Therefore, no matter whether the surface of the middle plate 52 is stamped and formed elastic sheet 523, or a spring or the middle plate 52 is changed to an elastic plate, the temperature sensing column 72 will not be overheated and melted during the processing. Yu. And this insulation cap 73 also can be used as temperature-sensing column 72 to strengthen insulation usefulness, for example: when temperature-sensing column 72 is made of Wood's eutectic metal, moreover, when this temperature-sensing column 72 melts instantly, this insulation As shown in FIG. 5 , the thermal insulation cap 73 can cover the melted temperature-sensing column 72 . Therefore, the insulating and heat insulating cap 73 can be used when it is necessary to enhance temperature resistance or insulation.

Based on the above, in this embodiment, the distance of the elastic displacement of the elastic piece 523 is much smaller than the distance of the elastic displacement of the spring 80. In this way, when the temperature-sensing column 72 melts, the elastic displacement of the spring 80 is relatively small. With a long distance, the middle plate 52 can be pushed away smoothly, and the middle plate 52 is separated from the extension portion 50a in an instant to form an open circuit (OFF), ensuring the safety of electricity use.

As shown in Figure 5, when the first contact 411 and the second contact 511 are in contact with each other (ON), and the temperature of the piezoresistor 71 (surge absorber) instantly rises to the default value when an overvoltage is encountered, the temperature sensing The column 72 melts instantly, so that the pressing force on the corresponding side of the spring 80 disappears. In this embodiment, the action part 50b has a rigid structure as a whole. When the temperature-sensing column 72 melts, the spring 80 pushes the middle plate 52 At this time, the second contact 511 provided on the upper portion 51 is forced to be separated from the first contact 411 to form an open circuit state (OFF). That is to say, in this embodiment, the rigid action part 50b can be L-shaped or bent, and can be formed separately from the extension part 50a, and its contact position can be provided with a third contact point opposite to each other. 53 and a fourth contact 54. At this time, not only the first contact 411 is separated from the second contact 511, but also the third contact 53 and the fourth contact 54 are also separated synchronously, but it is not limited thereto. For example: the middle section plate 52 can be set to be flexible, while the upper section 51 still maintains rigidity, so when the temperature sensing column 72 melts and the spring 80 pushes the middle section plate 52, the second section of the upper section 51 will The contact 511 does not move, the first contact 411 is not separated from the second contact 511, only the third contact 53 is separated from the fourth contact 54 to form an open circuit (OFF), and this can also be implemented.

In this embodiment, the extension portion 50a of the second lug 50 is provided at the bottom of the housing 31, but it is not limited thereto; Any direction (not shown in the figure) will not affect the implementation of the above-mentioned features of the present invention.

Figure 6 is an exploded perspective view of the main components of the present invention. The above-mentioned structure of the present invention can meet an overvoltage and when the temperature of the piezoresistor 71 instantly rises to the default value, the temperature-sensing column 72 instantly melts. It has an important feature, namely The temperature-sensing column 72 is designed to have a larger contact area with the piezoresistor 71 and is completely bonded with an adhesive medium. Since the varistor (MetalOxideVaristor or VoltageDependentResistor, VDR), also known as a varistor, is an electronic component with significant non-ohmic conductor properties, the resistance value will change with the external voltage, so its current-voltage characteristic curve has a significant The non-linearity is widely used in electronic circuits to protect the circuit from possible damage due to instantaneous voltage surges in the power supply system. The present invention uses piezoresistor 71 when the high voltage comes, its surface temperature rises rapidly, and the temperature sensing column 72 is designed to have a larger contact area with piezoresistor 71, so the temperature of piezoresistor 71 instantly rises to the default value value, the temperature-sensing column 72 can react quickly and melt instantly, so that the restraining force on the corresponding side of the spring 80 disappears, and then the action part 50b is displaced, forcing the first lug 40 and the second lug The output terminal of 50 forms an open circuit (OFF).

With the help of the above-mentioned technical features, the present invention solves the lack of an external thermal fuse and surge absorber in the existing current overload protection switch. In the internal space of the general current overload protection switch, a voltage overload protection device is skillfully built in. At this time, as the second lug 50 for current output, its action part 50b will quickly displace, so that the output end forms an open circuit structure, and the heat-generating piezoresistor 71 and the temperature-sensing column 72 of the meltable body are used to directly and Large-area contact can achieve faster and tighter heat conduction effects, which can ensure that the operation can be successful every time and the power can be cut off quickly before the high temperature is reached. Therefore, in addition to the current overload protection function of the present invention, the At the same time, the switch has an overvoltage protection design, which has the functions of safe electricity use and convenient configuration and use.

The above are only preferred embodiments of the present invention, and are not intended to limit the present invention in any form. Any simple modifications, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention still belong to within the scope of the technical solutions of the present invention.

In summary, the present invention fully meets the needs of industrial development in terms of structural design, practicability and cost-effectiveness, and the disclosed structure also has an unprecedented innovative structure, novelty, creativity and practicability, and meets the requirements of relevant According to the requirements of the invention patent requirements, the application is filed according to law.

Claims (8)

1. A current overload protection switch with lightning protection function, comprising: A housing with a pressing block at its upper end and a first lug, a second lug and a third lug at the bottom, wherein the first lug is provided with a double metal contact spring and a first A contact point, a second contact point that can be in contact with the first contact point is provided above the second lug; A linkage, one end of which is pivoted at the bottom of the pressure block, and the other end is linked to the free end of the contact spring, and the first contact on the contact spring is driven to contact the second contact by pressing the pressure block Conduction is formed, and when the current is overloaded, the curvature of the double metal contact reed is deformed due to temperature rise, and the first contact is separated from the second contact to form an open circuit to form a current overload protection switch form; characterized in that: The second lug includes an extension part protruding from the housing, an action part located in the housing, and the action part has an upper section for fixing the second contact, and an electrical connection with the upper section. a mid-section plate having a first side and an opposite second side, and at least a portion of a second side of the mid-section plate is in detachable electrical contact with the extension; A voltage overload protection element, which is composed of a piezoresistor and a temperature-sensing column. The column is composed of a heat-sensitive substance that melts instantly when it reaches a predetermined temperature, and its bottom surface is attached to the second surface of the piezoresistor, and the first surface of the piezoresistor is attached to the bonding surface of the third lug , forming an electrical contact, and making the front end of the temperature-sensing column face the first side of the middle plate, and at least contact a part of the first side; a spring, which has a first end and an opposite second end, and the first end is arranged on the second side of the middle plate, and the second end abuts against the stop surface provided in the housing, making the spring provide an elastic force toward the temperature-sensing column; In this way, when the first contact is in contact with the second contact, and the temperature of the piezoresistor rises instantaneously higher than the melting value of the temperature-sensing column when a high voltage is encountered, the temperature-sensing column melts, so that the restraining force on the corresponding side of the spring disappears , so that the action part is displaced, and the output terminals of the first wiring piece and the second wiring piece are forced to form an open circuit. 2 . The current overload protection switch with lightning protection function according to claim 1 , wherein the upper part of the action part and the middle plate form an L shape or a curved shape. 3 . 3. The current overload protection switch with lightning protection function according to claim 2, characterized in that a pivot hole is provided at the L-shaped connection between the upper part of the action part and the middle plate, and the relative position of the housing is A protruding shaft is provided for installation in the pivot hole, so that the action part presents a deflectable seesaw shape. 4 . The current overload protection switch with anti-lightning function according to claim 3 , wherein a third contact and a fourth contact are provided opposite to each other at the relative contact positions of the middle plate and the extension. 5 . 5 . The current overload protection switch with anti-lightning function according to claim 1 , wherein the temperature-sensing column is configured as a cone with the largest bottom area and tapered toward the front end. 6 . 6. The current overload protection switch with lightning protection function according to claim 5, characterized in that, the first side of the middle plate of the action part is provided with a protruding elastic piece in contact with the temperature-sensing column , and relative to the front end of the temperature-sensing column, the elastic sheet is provided with a positioning body concave toward the second side for the front-end of the temperature-sensing column to be embedded and positioned. 7 . The current overload protection switch with lightning protection function according to claim 6 , wherein an insulating and heat-insulating cap is provided at the front end of the temperature-sensing column. 8 . 8 . The current overload protection switch with lightning protection function according to claim 1 , wherein the second lug is arranged on any direction of the bottom or the side of the casing.