A low contact resistance safety socket

Abstract

A low contact resistance safety socket relates to the technical field of electrical equipment. It is composed of two containers connected by a hole and filled with liquid alloy metal. A soft sheet and a ferromagnetic metal plate are suspended above the liquid surface of the liquid alloy metal in the second container, and an electromagnet is arranged at the outer bottom. In the low contact resistance safety socket of the present invention, when the plug copper sheet is inserted into the socket, the electromagnet generates an electromagnetic force to attract the ferromagnetic metal plate and the soft sheet as a whole downward, forcing the liquid alloy metal level in the first container to rise, submerging the socket copper sheet and the plug copper sheet. Due to the characteristics of the liquid, the rising liquid metal fills the gap between the socket copper sheet and the plug copper sheet, thereby greatly reducing the contact resistance between the socket copper sheet and the plug copper sheet, and reducing the risk of fire caused by excessive heat during the use of the socket.

Description

Technical Field

[0001] The invention relates to the technical field of electrical equipment, and in particular to a low contact resistance safety socket. Background Art

[0002] Sockets are the most common and basic electrical connection devices. Unlike general electrical appliances, the use of plugs and sockets has two basic characteristics: one is that they are widely used; the other is that the consequences of abnormalities are serious. It is not uncommon for fires to occur due to excessive contact resistance at the connection point of plugs and sockets. Such fires occur so frequently, mainly due to the following reasons: in daily life, plugs are frequently plugged in and out of sockets, and the copper sheet used to make the metal sheet of the plug is deformed due to repeated insertion and withdrawal. Over time, the gripping force of the socket static sheet will decrease, and when the plug and socket are not in close contact, the contact resistance will increase, and when current passes through, it will generate much more heat than normal.

[0003] At the same time, when we use household appliances, in order to reduce the use of space and for aesthetic needs, we often put the plugs and sockets in corners, where dust easily accumulates, ventilation conditions are poor and they are easily neglected. When there is a lot of dust between the metal sheets of the plugs and sockets, the contact resistance will be too large due to poor contact and overheating will occur. In a closed environment, the heat is not easy to dissipate, and the temperature continues to rise, causing a fire. In addition, because the copper sheet of the plug is exposed to the air for a long time, the surface is oxidized or the copper sheet is stained with water or other pollutants, the plug and socket have poor contact and cause excessive contact resistance.

[0004] Therefore, it is necessary to develop a low contact resistance safety socket to reduce heat generation during use and avoid the occurrence of fire accidents. Summary of the invention

[0005] In order to solve the above problems, the present invention provides a low contact resistance safety socket, which can effectively reduce the contact resistance and improve the safety of use.

[0006] In order to achieve the above-mentioned object, the technical solution adopted by the present invention is: a low contact resistance safety socket, which is composed of a first container and a second container connected by a hole, wherein the first container and the second container are both made of insulating materials and filled with liquid alloy metal;

[0007] A soft sheet and a ferromagnetic metal plate are suspended above the liquid alloy metal surface in the second container, and the edge of the soft sheet wraps the end of the ferromagnetic metal plate to form a sealing structure with the inner wall of the second container; an electromagnet is arranged at the bottom of the outer side of the second container, and when the electromagnet is energized, it attracts the ferromagnetic metal plate to lower the liquid alloy metal surface in the second container, and presses the liquid alloy metal into the first container through the hole;

[0008] A socket copper sheet is arranged in the first container, and the socket copper sheet encloses an insertion area for the plug copper sheet. The outer area of ​​the socket copper sheet is placed in the second container. When the liquid alloy metal flows from the second container to the first container, the liquid alloy metal fills the gap between the socket copper sheet and the plug copper sheet.

[0009] As a preferred technical solution of the present invention, a travel switch is also provided in the first container, and the push rod of the travel switch is placed at the bottom end of the plug copper sheet insertion area. As the plug copper sheet is inserted, the push rod of the travel switch is subjected to downward pressure, so that the two contact points of its normally open contacts are closed.

[0010] As a preferred technical solution of the present invention, the two contact points of the normally open contact of the travel switch are respectively connected to the mains live wire L and the single-phase rectifier, and the input end of the single-phase rectifier is connected in series with the electromagnet. After the two contact points of the normally open contact of the travel switch are closed, the single-phase rectifier outputs a working voltage that matches the electromagnet, and the electromagnet generates a magnetic force to move the ferromagnetic metal plate downward, forcing the liquid alloy metal to flow into the first container.

[0011] As a preferred technical solution of the present invention, the liquid alloy metal is a gallium-indium-tin alloy.

[0012] As a preferred technical solution of the present invention, a stopper for controlling the movement of the ferromagnetic metal plate is provided in the second container, and the height of the stopper in the second container is higher than the top of the hole.

[0013] As a preferred technical solution of the present invention, the first container and the second container have the same height, and the bottom area of ​​the second container is larger than the bottom area of ​​the first container.

[0014] As a preferred technical solution of the present invention, an insulating cover plate is provided on the top of the plug copper sheet insertion area.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0016] The low contact resistance safety socket of the present invention, when the copper sheet of the plug is inserted into the socket, the push rod of the travel switch is also pressed downward, and the two contact points of the normally open contact of the travel switch are closed. The mains live wire is added to the single-phase rectifier, and the single-phase rectifier carries an AC220 voltage at this time, and the output end outputs a voltage matching the voltage of the electromagnet. The electromagnet generates an electromagnetic force, which attracts the ferromagnetic metal plate and the soft sheet as a whole downward, and moves downward to the stop position. The liquid alloy metal in the second container is pressed downward by the ferromagnetic metal plate and the soft sheet as a whole, and flows into the first container from the hole. The liquid level of the liquid alloy metal in the first container rises, submerging the copper sheet of the socket and the copper sheet of the plug. Due to the characteristics of the liquid, the rising liquid metal fills the gap between the copper sheet of the socket and the copper sheet of the plug, thereby greatly reducing the contact resistance between the copper sheet of the socket and the copper sheet of the plug, and reducing the risk of fire caused by excessive heating of the socket during use. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The low contact resistance safety socket of the present invention is further described in detail below in conjunction with the embodiments and drawings.

[0018] Figure 1 It is a structural schematic diagram of a low contact resistance safety socket.

[0019] Figure 2 It is a structural diagram of the travel switch.

[0020] Figure 3 This is a working diagram of a low contact resistance safety socket (after the plug spring is inserted).

[0021] Figure 4 This is the working principle diagram of the electromagnet. DETAILED DESCRIPTION

[0022] See also Figure 1 As shown, the present invention provides a low contact resistance safety socket, which is composed of a first container 1 and a second container 2. The first container 1 and the second container 2 are both made of insulating materials such as PC, nylon, ABS or electric jade powder. The first container 1 and the second container 2 have the same height, and the bottom area of ​​the second container 2 is larger than the bottom area of ​​the first container 1. The first container 1 and the second container 2 are connected through a hole 15, and the liquid alloy metal 6 in the two containers can flow to each other.

[0023] The liquid alloy metal 6 can be a gallium-indium-tin alloy, in which the weight proportions of gallium, indium and tin are 68.8%, 22.2% and 9% respectively. The melting point of the alloy of this component under 1 standard atmospheric pressure is 6°C. When the air pressure changes slightly, the melting point will also change slightly, but the change is not large. Therefore, in general indoor environments, the gallium-indium-tin alloy of this component is a liquid metal.

[0024] A soft sheet 4 and a ferromagnetic metal plate 3 are suspended above the liquid alloy metal 6 in the second container 2, and the edge of the soft sheet 4 wraps the end of the ferromagnetic metal plate 3 to form a sealing structure with the inner wall of the second container 2. The soft sheet 4 can be made of materials such as silicone, PC, nylon or ABS, and the bottom of the ferromagnetic metal plate 3 is tightly bonded to the upper part of the soft sheet 4 to form an integral component.

[0025] An electromagnet 7 is provided at the outer bottom of the second container 2. It has no magnetism when not powered, but can attract the ferromagnetic metal plate 3 when powered, so that the liquid level of the liquid alloy metal 6 in the second container 2 drops, and the liquid alloy metal 6 is pressed into the first container 1 through the hole 15.

[0026] A stopper 5 for controlling the displacement of the ferromagnetic metal plate 3 is arranged in the second container 2, and the stopper 5 is higher than the top of the hole 15 in the second container 2. The stopper 5 is used to prevent the ferromagnetic metal plate 3 from moving too far toward the bottom of the second container 2 due to the attraction of the electromagnetic force.

[0027] A socket copper sheet 9 (which can be the L pole or N pole of a single-phase socket, or the A pole, B pole, C pole or N pole of a three-phase socket) and a travel switch 8 are arranged in the first container 1. The socket copper sheet 9 encloses an insertion area for the plug copper sheet 10. The outer area of ​​the socket copper sheet 9 is placed in the second container 2. When the liquid alloy metal 6 flows from the second container 2 to the first container 1, the liquid alloy metal 6 fills the gap between the socket copper sheet 9 and the plug copper sheet 10.

[0028] The push rod 11 of the travel switch 8 is placed at the bottom of the plug copper sheet insertion area. Please refer to Figure 2 As shown, the opening and closing conditions of the contacts inside the travel switch 8 will change when the push rod 11 is under pressure or not under pressure. When the push rod is not subjected to external force, the two contact points 12 and 13 of the normally open contact are in an open state. As the plug copper sheet 10 is inserted, the push rod 11 of the travel switch 8 is subjected to downward pressure, so that the two contact points 12 and 13 of the normally open contact are closed.

[0029] See also Figure 4 As shown, the two contact points 12 and 13 of the normally open contact of the limit switch 8 are respectively connected to the mains live wire L and the single-phase rectifier 14, and the input end of the single-phase rectifier 14 is connected in series with the electromagnet 7. After the two contact points 12 and 13 of the normally open contact of the limit switch 8 are closed, the single-phase rectifier 14 outputs a working voltage matching the electromagnet 7, and the electromagnet 7 generates a magnetic force to move the ferromagnetic metal plate 3 downward to force the liquid alloy metal 6 to flow into the first container 1.

[0030] When you need to use a socket to power an appliance, insert the plug into the socket. Assuming that the copper sheet of the socket is the live copper sheet of a single-phase socket (L-end copper sheet), insert the plug into the socket and insert the live copper sheet of the plug between the two copper sheets of the socket. The two copper sheets of an ordinary socket are clamped with a spring to ensure that the copper sheet of the socket and the copper sheet of the plug are tightly combined to reduce contact resistance. However, since the plug is frequently plugged in and out, the spring clamping is not tight, the copper sheet is aged, and dust falls on the copper sheet, which increases the contact resistance between the copper sheet of the socket and the copper sheet of the plug.

[0031] However, in the low contact resistance safety socket of the present invention, when the plug copper sheet 10 is inserted into the socket ( Figure 3 As shown), the push rod 11 of the travel switch 8 is also pressed downward, and the two contact points 12 and 13 of the normally open contact of the travel switch are closed. Figure 4 As shown, the mains live wire is added to the single-phase rectifier 14. At this time, the single-phase rectifier 14 carries an AC 220 voltage, and the output end outputs a voltage matching the voltage of the electromagnet 7. The electromagnet 7 generates an electromagnetic force to attract the ferromagnetic metal plate 3 and the soft sheet 4 downward as a whole, and moves downward to the stopper 5 position. The liquid alloy metal in the second container 2 is pressed downward by the ferromagnetic metal plate 3 and the soft sheet 4 as a whole, and flows into the first container 1 from the hole 15. The liquid level of the liquid alloy metal in the first container 1 rises, submerging the socket copper sheet 9 and the plug copper sheet 10. Due to the characteristics of the liquid, the rising liquid metal fills the gap between the socket copper sheet 9 and the plug copper sheet 10, thereby greatly reducing the contact resistance between the socket copper sheet and the plug copper sheet, and reducing the risk of fire caused by excessive heat during use of the socket.

[0032] When the socket is no longer needed to power the appliance, the plug is pulled out from the socket, the plug copper sheet 10 is pulled out from the socket copper sheet 9, the push rod 11 of the travel switch 8 is no longer subjected to downward pressure, the two contact points 12 and 13 of its normally open contact are opened, the single-phase rectifier 14 loses power, the DC voltage applied to the electromagnet 7 disappears, the electromagnet loses its electromagnetic force, and due to the effect of gravity, the liquid metal in the first container 1 flows back to the container 2 through the hole 15 and returns to the initial state.

[0033] when Figure 1 , 3 When the socket copper sheet is the neutral wire end copper sheet (N end copper sheet) of a single-phase socket, or the A phase end copper sheet, B phase end copper sheet, C phase end copper sheet and N end copper sheet of a three-phase socket, the working principle is exactly the same as before.

[0034] The reason why the ferromagnetic metal plate 3 is wrapped with a soft sheet 4 is to reduce the wear of the ferromagnetic metal plate 3 on the second container 2 during the up and down movement, and to extend the service life. The reason why the two contact points 12 and 13 of the normally open contact of the travel switch 8 are connected in series in the live wire (L pole) of the mains electricity is that when the socket is not used to power the appliance, the single-phase rectifier 14 is not energized to avoid power loss. The reason why the bottom area of ​​the second container 2 is larger than the bottom area of ​​the first container 1 is that when the liquid level in the second container 2 drops less, the liquid level in the first container 1 will rise more, reducing the liquid level rising time, filling the gap between the socket copper sheet 9 and the plug copper sheet 10 in a shorter time, and quickly reducing the contact resistance to reduce the temperature rise. An insulating cover plate 16 is provided on the top of the plug copper sheet insertion area to prevent the outflow of liquid alloy metal when the plug is not inserted.

[0035] The role of the liquid alloy metal is to fill the gap between the copper sheet of the plug and the copper sheet of the socket after the plug is inserted into the socket, so as to reduce the contact resistance between the copper sheet of the plug and the copper sheet of the socket. The volume of the first container 1 and the second container 2 does not need to be very large, so the amount of liquid metal required to fill the gap between the copper sheet of the plug and the copper sheet of the socket is not large, which will increase the cost of the socket but not too much. Moreover, because the liquid alloy metal has been used to fill the gap between the copper sheet of the plug and the copper sheet of the socket, the contact resistance between the two is greatly reduced, and the amount of metal copper used in the copper sheet of the plug and the copper sheet of the socket can be appropriately reduced to offset the increased cost.

[0036] Take the plug and socket with a rated current of 16 amperes as an example. The typical data is that the copper sheet of the plug is 1.6 cm long and 0.76 cm wide. After the plug is inserted into the socket, the contact area is 1.064 square centimeters (the copper sheet of the plug cannot be fully inserted into the socket, and the length of the insertion into the socket is about 1.4 cm). The average width of the gap between the copper sheet of the plug and the copper sheet of the socket is about 0.02 cm, so a total of 0.02128 cubic centimeters of liquid metal is required. The density of gallium, indium, and tin alloys with weight proportions of 68.8%, 22.2%, and 9% respectively is 6.34 grams per cubic centimeter, so 0.1349152 grams of liquid metal is needed to fill the gap between the copper sheet of the plug and the copper sheet of the socket. Even if the liquid metal in the container is designed according to ten times the amount, only 1.349152 grams of liquid metal is needed. Obviously, the amount of liquid alloy metal is not large, and there will be no significant increase in the cost of the socket. Customers with high requirements for socket safety can fully accept this price.

[0037] The above contents are merely examples and explanations of the concept of the present invention. The technicians in this technical field may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the concept of the invention or exceed the scope defined by the claims, they should all fall within the protection scope of the present invention.

Claims

1. A low contact resistance safety socket, characterized in that: It is composed of a first container (1) and a second container (2) which are connected via a hole (15); the first container (1) and the second container (2) are both made of insulating material and are filled with liquid alloy metal (6); A soft sheet (4) and a ferromagnetic metal plate (3) are suspended above the liquid level of the liquid alloy metal (6) in the second container (2), and the edge of the soft sheet (4) wraps around the end of the ferromagnetic metal plate (3) so that it forms a sealing structure with the inner wall of the second container (2); an electromagnet (7) is arranged at the bottom of the outer side of the second container (2), and when the electromagnet is energized, it attracts the ferromagnetic metal plate (3), causing the liquid level of the liquid alloy metal (6) in the second container (2) to drop, and presses the liquid alloy metal (6) into the first container (1) through the hole (15); A socket copper sheet (9) is arranged in the first container (1), the socket copper sheet (9) encloses an insertion area for the plug copper sheet (10), and an outer area of ​​the socket copper sheet (9) is placed in the second container (2), and when the liquid alloy metal (6) flows from the second container (2) to the first container (1), the liquid alloy metal (6) fills the gap between the socket copper sheet (9) and the plug copper sheet (10); A travel switch (8) is also provided in the first container (1), and a push rod (11) of the travel switch (8) is placed at the bottom end of the plug copper sheet insertion area. As the plug copper sheet (10) is inserted, the push rod (11) of the travel switch (8) is subjected to downward pressure, so that two contact points (12, 13) of its normally open contact are closed; The two contact points (12, 13) of the normally open contact of the travel switch (8) are respectively connected to the mains live wire L and the single-phase rectifier (14); the input end of the single-phase rectifier (14) is connected in series with the electromagnet (7); after the two contact points (12, 13) of the normally open contact of the travel switch (8) are closed, the single-phase rectifier (14) outputs a working voltage matching the electromagnet (7), and the electromagnet (7) generates a magnetic force to move the ferromagnetic metal plate (3) downward, forcing the liquid alloy metal (6) to flow into the first container (1); The liquid alloy metal (6) is a gallium-indium-tin alloy; A stopper (5) for controlling the movement of the ferromagnetic metal plate (3) is provided in the second container (2); the stopper (5) is higher than the top of the hole (15) in the second container (2).

2. The low contact resistance safety socket according to claim 1, characterized in that: The first container (1) and the second container (2) have the same height, and the bottom area of ​​the second container (2) is larger than the bottom area of ​​the first container (1).

3. The low contact resistance safety socket according to claim 1, characterized in that: An insulating cover plate (16) is provided on the top of the insertion area of ​​the plug copper sheet (10).

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