Cable short circuit protection switch

Abstract

The utility model relates to the technical field of cable switches, in particular to a cable short-circuit protection switch, which comprises a switch shell and a partition plate fixedly connected inside the switch shell, the partition plate divides the inside of the switch shell into a lower high-pressure bin and an upper normal-pressure bin, the high-pressure bin is filled with inert gas, and the normal-pressure bin is filled with inert gas. The internal air pressure of the high-pressure bin is higher than the external atmospheric pressure; the moving contact and the static contact are both installed in the high-voltage bin, the high-voltage bin is filled with inert gas, the inert gas is used for insulation, an electric arc area can be rapidly cooled, the electric arc temperature can be reduced, and therefore the electric arc can be rapidly extinguished, and the electric arc can be rapidly extinguished when the electric arc is generated when a switch is switched off due to short circuit of a cable and instant large current. And the cable and the switch are well protected. In addition, the air pressure in the high-voltage bin is slightly higher than the external atmospheric pressure, so that external air cannot enter the high-voltage bin, and the arc extinguishing function of the high-voltage bin is not affected even if some micro gas leaks.

Description

TECHNICAL FIELD

[0001] The utility model relates to cable switch technical field especially relates to a cable short circuit protection switch. BACKGROUND

[0002] In general life, using air switch or fuse can disconnect the circuit in time when the cable is short-circuited, and avoid the expansion of damage. But in some high-voltage power supply scenarios, because the power is high, very large current will appear when the circuit breaker is short-circuited, so very large arc is easy to produce when the circuit breaker is disconnected. It may be harmful to the cable and the circuit breaker itself.

[0003] In order to protect the cable, the circuit breaker and other equipment, arc extinguishing function needs to be set in the circuit breaker, and the most common arc extinguishing methods include oil-cooled arc extinguishing, metal grid arc extinguishing and vacuum arc extinguishing. In addition, inert gas is filled in the circuit breaker to extinguish arc, and the inert gas is not only insulating but also can quickly cool the arc area to reduce the arc temperature, so as to quickly extinguish the arc.

[0004] However, filling inert gas in the circuit breaker needs to ensure the sealing performance of the circuit breaker to prevent external air, especially oxygen, from entering the circuit breaker. In daily life, it is difficult to maintain perfect sealing performance all the time, so micro leakage is easy to occur. How to keep the circuit breaker in normal use under this condition is a problem.

[0005] In addition, whether manually or electrically or hydraulically driven, the power source of many circuit breakers is outside the circuit breaker, so the operating rod for operating the contact separation needs to pass through the circuit breaker and can slide in and out. This not only brings greater challenge to the sealing performance of the circuit breaker, but also causes the internal air pressure of the sealed circuit breaker to change when the operating rod slides in and out, which further affects the operation of the operating rod and the contact, and affects the normal operation of the circuit breaker. SUMMARY

[0006] Therefore, the utility model aims at providing a cable short circuit protection switch to solve the problem of inert gas arc extinguishing in the prior art.

[0007] In order to achieve the above purpose, the utility model provides a cable short circuit protection switch, which comprises a switch shell and cables fixedly connected on both sides of the switch shell, two static contacts fixedly connected in the switch shell and connected with the two cables respectively, and the short circuit protection switch further comprises:

[0008] A partition plate fixedly connected in the switch shell, which divides the switch shell into a high-pressure chamber at the lower part and a normal-pressure chamber at the upper part, the high-pressure chamber is filled with inert gas, and the internal air pressure of the high-pressure chamber is higher than the external atmospheric pressure;

[0009] A movable contact is connected inside the high-pressure chamber. The movable contact works with the stationary contact to control the on / off state of the cable, and an operating lever is fixedly connected to the movable contact.

[0010] Furthermore, the outer end of the operating rod passes through the partition and the top plate of the switch housing and is connected to an external power source. Sealing rings are provided at the connection points between the operating rod and the partition and the top plate of the switch housing.

[0011] Furthermore, a detachable door is provided on the front of the switch housing, and a sealing strip is provided at the connection between the front of the switch housing and the partition and the door.

[0012] Furthermore, a gas supply pipe is fixedly connected to the bottom of the switch housing. The gas supply pipe is connected to the high-pressure chamber for supplying inert gas, and a solenoid valve is also provided on the gas supply pipe.

[0013] Furthermore, the atmospheric pressure chamber is equipped with several pressure cylinders, which are fixedly connected to a partition plate. The partition plate is also equipped with a vent that connects the pressure cylinders and the high pressure chamber. A piston plate is slidably connected inside the pressure cylinder, and a counterweight is fixedly connected to the bottom of the piston plate.

[0014] Furthermore, a pressure spring is also provided inside the pressure cylinder above the piston plate, with the two ends of the pressure spring connected to the upper end of the piston plate and the top plate of the pressure cylinder, respectively.

[0015] Furthermore, the inert gas is SF, argon, or nitrogen, preferably nitrogen.

[0016] Furthermore, an elastic pad is provided directly below the moving contact, and the elastic pad is fixedly connected to the floor of the switch housing.

[0017] The beneficial effects of this utility model are as follows: 1. A high-voltage chamber is set inside the switch housing, and the moving and stationary contacts used to control the on / off state of the cable are placed inside the high-voltage chamber. The high-voltage chamber is filled with inert gas. The inert gas has the characteristics of insulation and rapid cooling of the arc area, which reduces the arc temperature and thus quickly extinguishes the arc. When a short circuit occurs in the cable and a large instantaneous current causes the switch to open, the arc is quickly extinguished, which effectively protects the cable and the switch itself.

[0018] 2. Fill the high-pressure chamber with an extra amount of inert gas, making the internal pressure slightly higher than the external atmospheric pressure. Therefore, even if the high-pressure chamber's seal is not perfect and some minor gas leakage occurs, the leakage will be from the inside out, preventing external air, especially oxygen, from entering the chamber. Thus, even minor gas leakage will not affect the arc-extinguishing function of the high-pressure chamber. Nitrogen is the best inert gas to use, as any leakage will not affect the external environment.

[0019] 3. A plurality of pressurizing cylinders are arranged in the normal pressure bin and communicated with the high pressure bin, a piston plate is arranged in the pressurizing cylinder, a pressurizing spring and a counterweight are arranged on the piston plate, when the nitrogen in the high pressure bin leaks and causes the pressure in the high pressure bin to decrease, the piston plate moves downward under the action of the pressurizing spring and the counterweight, the space is reduced, and the pressure in the high pressure bin is slightly higher than the external atmospheric pressure. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only a part of the present application, and other drawings can also be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0021] Figure 1 It is a schematic diagram of the overall structure of the device of the present application.

[0022] Figure 2 It is a schematic diagram of the internal structure of the switch housing in the device of the present application.

[0023] Figure 3 It is a schematic diagram of the internal structure of the device of the present application.

[0024] Figure 4 It is Figure 3 It is an enlarged view of part A in the figure.

[0025] In the figure, the mark is:

[0026] 01, cable, 101, switch housing, 102, bin door, 103, operating rod, 104, gas pipe, 105, electromagnetic valve, 106, partition, 107, high pressure bin, 108, normal pressure bin, 109, static contact, 110, dynamic contact, 111, elastic pad, 112, sealing strip, 113, sealing ring, 114, pressurizing cylinder, 115, air vent, 116, piston plate, 117, pressurizing spring, 118, counterweight. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical scheme and advantages of the present application more clear and obvious, the following will further describe the present application in combination with specific embodiments.

[0028] It should be noted that, unless otherwise defined, technical or scientific terms used in the present application should be understood as their common meanings to those skilled in the art to which the present application belongs. The terms "first", "second" and similar words used in the present application do not represent any order, quantity or importance, but are only used to distinguish different components. The terms "include" or "contain" and similar words mean that the elements or objects before the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects. The terms "connect" or "connected" and similar words are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to represent relative positional relationships, which may change accordingly when the absolute position of the described object changes.

[0029] The first aspect of the present application is shown in Figure 1 and Figure 2 For some high-voltage power consumption scenarios, due to high power, very large current will occur when the circuit breaker is short-circuited, so very large arc is easily generated when the circuit breaker is disconnected. In order to prevent the arc from causing harm to the cable and the circuit breaker itself, the present application fills the switch housing 101 with inert gas for arc extinguishing.

[0030] Specifically, the cable 01 is fixedly connected to both sides of the switch housing 101, and two static contacts 109 are fixedly connected in the switch housing 101 and connected to the two cables 01 respectively. A partition plate 106 is fixedly connected inside the switch housing 101, which divides the switch housing 101 into a high-pressure chamber 107 below and a normal-pressure chamber 108 above. The high-pressure chamber 107 is filled with inert gas, and the internal pressure of the high-pressure chamber 107 is higher than the external atmospheric pressure. The static contact 109 and the moving contact 110 are placed in the high-pressure chamber 107.

[0031] Preferably, a resilient pad 111 is further provided below the moving contact 110, which is fixedly connected to the floor of the switch housing 101. This avoids bumping when the moving contact 110 operates.

[0032] The cable 01 passes through when the moving contact 110 and the static contact 109 are connected, and the cable 01 is disconnected when the moving contact 110 and the static contact 109 are separated. In the event of a short circuit, the moving contact 110 and the static contact 109 can automatically separate, utilize inert gas insulation, and quickly cool the arc area to reduce the arc temperature, thereby rapidly extinguishing the arc. In the event of a short circuit in the cable, the inert gas can effectively extinguish the arc generated when the moving contact 110 and the static contact 109 separate, thereby effectively protecting the cable 01 and the switch itself.

[0033] The second aspect of the utility model, as shown in Figure 2 、 Figure 3 and Figure 4 As shown in the fullness of inert gas in high pressure warehouse 107 is used to extinguish arc, in order to prevent switch shell 101 leakage, ensure the sealing of high pressure warehouse 107.The front of switch shell 101 is provided with detachable warehouse door 102, and the front of switch shell 101 and baffle 106 and the connecting place of warehouse door 102 are provided with sealing strip 112.Detachable warehouse door 102 is provided to facilitate the installation and removal of the whole equipment and maintenance operation.

[0034] In addition, the power source of circuit breaker is generally outside switch shell 101, for example manual switch, so an operating rod 103 is needed to be connected from outside to the movable contact 110 of switch shell 101, so that workers can control the on-off of circuit breaker from outside.This also leads to the sliding expansion of operating rod 103 inside and outside switch shell 101, not only brings greater challenge to the sealing performance of circuit breaker, but also causes the internal pressure of sealed circuit breaker to change when the operating rod expands and contracts, and then reversely affects the action of operating rod and contact, and affects the normal action of circuit breaker.

[0035] Therefore, the outer end of operating rod 103 is arranged to pass through baffle 106 and the top plate of switch shell 101 and is connected to the external power source, and sealing ring 113 is arranged at the connecting place of operating rod 103 and baffle 106 and the top plate of switch shell 101.

[0036] But because in daily life, it is difficult to maintain perfect sealing, so it is easy to appear trace leakage.In order to use the arc extinguishing function of circuit breaker normally in this case.

[0037] First, more inert gas is filled in high pressure warehouse 107, so that the gas pressure in high pressure warehouse 107 is slightly higher than the external atmospheric pressure, and a plurality of pressurizing cylinders 114 are arranged in normal pressure warehouse 108, the pressurizing cylinders 114 are fixedly connected to baffle 106, and baffle 106 is further provided with air vent 115 communicating pressurizing cylinders 114 and high pressure warehouse 107, the piston plate 116 is slidably connected in pressurizing cylinders 114, and the counterweight 118 is fixedly connected to the bottom of piston plate 116.

[0038] Preferably, pressurizing spring 117 is further arranged in pressurizing cylinders 114 above piston plate 116, and the two ends of pressurizing spring 117 are connected to the upper end of piston plate 116 and the top plate of pressurizing cylinders 114 respectively.

[0039] When the nitrogen gas in the high-pressure chamber 107 leaks, the piston plate 116 moves downward under the action of the pressurizing spring 117 and the counterweight 118, reducing the space and maintaining the gas pressure in the high-pressure chamber 107 slightly higher than the external atmospheric pressure.

[0040] Therefore, even if the sealing of the high-pressure chamber 107 is not perfect and some gas leaks, the external air, especially oxygen, cannot enter the high-pressure chamber 107, and thus the arc extinguishing function of the high-pressure chamber 107 is not affected even if some gas leaks. The inert gas is preferably nitrogen, and even if it leaks, it will not affect the external environment.

[0041] Preferably, the bottom of the switch housing 101 is fixedly connected with a gas delivery pipe 104 which communicates with the high-pressure chamber 107 for delivering inert gas, and the gas delivery pipe 104 is further provided with an electromagnetic valve 105. The nitrogen gas can be supplemented in time.

[0042] As described above, the high-pressure chamber 107 is arranged in the switch housing 101, the movable contact 110 and the fixed contact 109 for controlling the on-off of the cable 01 are placed in the high-pressure chamber 107, and the high-pressure chamber 107 is filled with inert gas. The inert gas is used for insulation, and can quickly cool the arc area, reduce the arc temperature, and thus quickly extinguish the arc. When the cable is short-circuited and a large current is generated to cause the switch to open, the arc can be quickly extinguished, and the cable 01 and the switch itself are well protected. The high-pressure chamber 107 is filled with more inert gas, so that the gas pressure in the high-pressure chamber 107 is slightly higher than the external atmospheric pressure. Therefore, even if the sealing of the high-pressure chamber 107 is not perfect and some gas leaks, the external air, especially oxygen, cannot enter the high-pressure chamber 107, and thus the arc extinguishing function of the high-pressure chamber 107 is not affected even if some gas leaks. The inert gas is preferably nitrogen, and even if it leaks, it will not affect the external environment. In addition, a plurality of pressurizing cylinders 114 which communicate with the high-pressure chamber 107 are arranged in the normal-pressure chamber 108, the piston plate 116 is arranged in the pressurizing cylinder 114, the pressurizing spring 117 and the counterweight 118 are arranged on the piston plate 116, and when the nitrogen gas in the high-pressure chamber 107 leaks, the piston plate 116 moves downward under the action of the pressurizing spring 117 and the counterweight 118, reducing the space and maintaining the gas pressure in the high-pressure chamber 107 slightly higher than the external atmospheric pressure.

[0043] It should be understood by those of ordinary skill in the art that the discussion of any of the above embodiments is merely exemplary and is not intended to suggest that the scope of the present application includes only these examples; the above embodiments or technical features among different embodiments can also be combined, the steps can be implemented in any order, and there are many other changes of different aspects of the present application as described above, which are not provided in detail for the sake of brevity.

[0044] The present application is intended to cover all such alternatives, modifications, and variations as fall within the broad scope of the appended claims. Accordingly, any and all such alternatives, modifications, equivalents, improvements and the like are intended to be encompassed by the present application.

Claims

1. A cable short-circuit protection switch, comprising a switch housing (101) and cables (01) fixedly connected on both sides of the switch housing (101), two static contacts (109) fixedly connected in the switch housing (101) and connected with the two cables (01) respectively, characterized in that, The short-circuit protection switch further comprises: a partition plate (106) fixedly connected inside the switch shell (101), which divides the switch shell (101) into a high-pressure chamber (107) below and an atmospheric-pressure chamber (108) above, the high-pressure chamber (107) is filled with inert gas, and the internal pressure of the high-pressure chamber (107) is higher than the external atmospheric pressure; a movable contact (110) movably connected in the high-pressure chamber (107), which cooperates with the fixed contact (109) to control the on-off of the cable (01), and the movable contact (110) is fixedly connected with an operating rod (103).

2. A cable short circuit protection switch according to claim 1, characterized in that The outer end of the operating rod (103) penetrates the partition plate (106) and the top plate of the switch shell (101) and is connected to an external power source, and sealing rings (113) are arranged at the connection positions of the operating rod (103) and the partition plate (106) and the top plate of the switch shell (101).

3. A line short circuit protection switch according to claim 1, characterized in that, The front surface of the switch shell (101) is provided with a detachable chamber door (102), and sealing strips (112) are arranged at the connection positions of the front surfaces of the switch shell (101) and the partition plate (106) and the chamber door (102).

4. A line short circuit protection switch according to claim 1, characterized in that, The bottom of the switch shell (101) is fixedly connected with a gas delivery pipe (104) which communicates with the high-pressure chamber (107) for delivering inert gas, and the gas delivery pipe (104) is further provided with a solenoid valve (105).

5. A line short circuit protection switch according to claim 1 or 4, characterized in that A plurality of pressurizing cylinders (114) are arranged in the atmospheric-pressure chamber (108), the pressurizing cylinders (114) are fixedly connected to the partition plate (106), and the partition plate (106) is further provided with air vents (115) communicating the pressurizing cylinders (114) and the high-pressure chamber (107), and the pressurizing cylinders (114) are slidably connected with piston plates (116), and the bottom of the piston plate (116) is fixedly connected with a counterweight (118).

6. A line short circuit protection switch according to claim 5, characterized in that A pressurizing spring (117) is further arranged in the pressurizing cylinder (114) above the piston plate (116), and the two ends of the pressurizing spring (117) are connected to the upper end of the piston plate (116) and the top plate of the pressurizing cylinder (114) respectively.

7. A line short circuit protection switch according to claim 1 or 4, characterized in that, The inert gas is SF6, argon or nitrogen, and preferably nitrogen.

8. A line short circuit protection switch according to claim 1, characterized in that, An elastic pad (111) is further arranged below the movable contact (110), and the elastic pad (111) is fixedly connected to the floor of the switch shell (101).

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