Moving contact with air suction structure and high-speed grounding switch

Abstract

The utility model relates to the field of high-voltage switches with arc extinguishing devices, in particular to a moving contact with an air suction structure and a high-speed grounding switch. The moving contact with the air suction structure comprises an air cylinder, the air cylinder is sleeved outside the moving contact, a radial convex edge is arranged on the moving contact, a lining with an L-shaped section is arranged on the convex edge, one side of the lining is tightly attached to the end face of the convex edge, and the other side of the lining is tightly attached to the side wall of the convex edge. And the bushing is in sliding sealing fit with the air cylinder. The bushing of the moving contact with the air suction structure is not limited by the length of the convex edge, the area of the sealing surface of the bushing and the air cylinder is increased, the problem of air leakage of the air cylinder caused by a gap between the bushing and the air cylinder even in the rapid moving process of the moving contact is solved, and the breaking capacity to induced current is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of high -voltage switch with arc extinguishing device especially, a kind of movable contact with air suction structure and quick grounding switch. BACKGROUND

[0002] With the rapid development of power system, sulfur hexafluoride (SF6) is widely used in medium voltage, high voltage, ultra-high voltage power equipment and transmission line due to its good insulation performance, strong arc extinguishing ability and high dielectric strength, but sulfur hexafluoride (SF6) has strong greenhouse effect, C4F7N environmental gas is usually used to replace sulfur hexafluoride (SF6) due to its good insulation performance. Taking 145kV quick grounding switch as an example, the insulation performance of C4F7N environmental gas as medium has great difference with pure sulfur hexafluoride (SF6), and the recovery ability of C4F7N environmental gas medium is poor. Through experimental experience, it is found that the existing C4F7N environmental gas quick grounding switch is prone to insulation breakdown at the break of movable contact and static contact during the process of closing inductive current. In order to solve this problem, the commonly used method is to use the air suction type movable contact structure, so that the external gas enters the cylinder through the movable contact and forms a gas flow at the end of the movable contact to take away the arc heat and metal particles, thereby achieving the effect of arc extinguishing.

[0003] A kind of movable contact with air suction structure is disclosed in Chinese invention patent with authorization announcement number CN105448591B and authorization announcement date April 13, 2018, which includes a cylinder, a piston is installed in the cylinder, a piston ring is arranged between the piston and the cylinder and is in sliding sealing cooperation with the cylinder through the piston ring, and an air suction cavity is formed around the cylinder wall corresponding to the lower part of the cylinder when the piston moves in the cylinder. A tubular movable arc contact that moves synchronously with the piston is arranged on the lower side of the piston, and an air suction hole is arranged on the movable arc contact. The piston in the cylinder can move reciprocatingly with the movable arc contact to realize opening and closing operation. When the piston moves upward with the movable arc contact to open, the air suction hole on the movable arc contact is communicated with the air suction cavity to make the air suction cavity communicated with the outside through the cavity of the movable arc contact, thereby realizing air suction arc extinguishing. However, the piston of the movable contact is in sliding sealing cooperation with the cylinder through the piston ring, and the piston ring is embedded on the side wall of the piston, so the length of the piston ring is limited by the length of the piston, and the sealing surface between the piston ring and the cylinder is small. There is still a problem of cylinder pressure leakage during the fast movement of the piston. UTILITY MODEL CONTENTS

[0004] The utility model aims at providing a kind of movable contact with air suction structure to solve the problem of cylinder pressure leakage during the fast movement of the piston of the existing movable contact with air suction structure;The utility model also aims at providing a kind of quick grounding switch using the movable contact with air suction structure.

[0005] In order to achieve the above object, the utility model discloses a movable contact with air suction structure adopts the following technical scheme:

[0006] The movable contact with air suction structure includes a cylinder, the cylinder is sleeved on the movable contact, a radial flange is arranged on the movable contact, a bushing with L-shaped section is arranged on the flange, one side of the bushing is closely attached to the end face of the flange, and the other side is closely attached to the side wall of the flange.

[0007] Further, a guide sleeve is arranged between the movable contact and the lower end of the cylinder, and the movable contact and the lower end of the cylinder are in sliding sealing cooperation through the guide sleeve.

[0008] Further, a spring contact finger is arranged between the lower end of the cylinder and the movable contact.

[0009] Further, the movable contact is provided with a middle through hole, and air holes are arranged on the side wall of the movable contact.

[0010] Further, the bushing is fixedly installed on the side of the flange away from the inside of the cylinder.

[0011] Beneficial effects: the utility model discloses a movable contact with air suction structure is the improved invention creation, the movable contact with air suction structure of the utility model is provided with radial flange, installs the L-shaped bushing on the movable contact and is in sliding sealing cooperation between the bushing and the cylinder, and the side of the bushing is in sliding sealing with the cylinder, and the side of the bushing is closely attached to the side wall of the flange and is not embedded on the side wall of the flange, so that the length is not limited by the length of the flange of the movable contact, and the sealing surface between the cylinder is larger, and in the process of the rapid movement of the movable contact, the gap between the bushing and the cylinder does not appear, so that the cylinder appears the phenomenon of pressure relief and air leakage, and the breaking capacity for induced current is improved.

[0012] The utility model discloses a following technical scheme is adopted to the quick grounding switch:

[0013] The utility model discloses a quick grounding switch, including the cylinder, setting up the bracket in the cylinder, install movable contact on the bracket, the movable contact includes cylinder, the cylinder is sleeved on the movable contact, radial flange is arranged on the movable contact, the bushing with L-shaped section is arranged on the flange, one side of the bushing is closely attached to the end face of the flange, and the other side is closely attached to the side wall of the flange.

[0014] Further, a guide sleeve is arranged between the movable contact and the lower end of the cylinder, and the movable contact and the lower end of the cylinder are in sliding sealing cooperation through the guide sleeve.

[0015] Further, a spring contact finger is arranged between the lower end of the cylinder and the movable contact.

[0016] Further, the moving contact is provided with a middle through hole, and the gas hole is formed on the side wall of the moving contact.

[0017] Further, the bushing is fixedly installed on one side of the convex edge away from the inside of the cylinder.

[0018] Beneficial effects: the quick grounding switch is an improved invention. The quick grounding switch improves the structure of the moving contact, and is provided with a radial convex edge on the moving contact. The L-shaped bushing is installed on the moving contact and is in sliding sealing cooperation between the bushing and the cylinder. The side surface of one side of the bushing is in sliding sealing cooperation with the cylinder, and the side wall of one side of the bushing is closely attached to the side wall of the convex edge and is not embedded in the side wall of the convex edge. Therefore, the length of the bushing is not limited by the length of the convex edge of the moving contact, the sealing surface between the bushing and the cylinder is larger, and in the process of rapid movement of the moving contact, the bushing and the cylinder will not appear gaps, so that the cylinder will not appear pressure relief and air leakage, and the breaking capacity of the induced current is improved. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 It is a structural schematic view of one embodiment of the moving contact with the air suction structure of the utility model;

[0020] Figure 2 It is a structural schematic view of another embodiment of the moving contact with the air suction structure of the utility model;

[0021] Figure 3 It is a structural schematic view of one embodiment of the quick grounding switch of the utility model;

[0022] Figure 4 It is a gas flow schematic view of the quick grounding switch of the utility model.

[0023] In the figure: 1, moving contact; 2, cylinder; 3, bushing; 4, guide sleeve; 5, spring contact finger; 6, middle through hole; 7, gas hole; 8, bolt; 9, cylinder body; 10, bracket; 11, support; 12, grounding insulator; 13, static contact. DETAILED DESCRIPTION

[0024] The features and performances of the utility model are further described in detail in combination with the embodiments.

[0025] The bushing of the moving contact with the air suction structure of the utility model is closely attached to the side wall of the convex edge of the moving contact and is not embedded in the side wall of the convex edge, so that the length of the bushing is not limited by the length of the convex edge. Therefore, the sealing area between the bushing and the cylinder can be increased, and the problem that the sealing surface between the cylinder and the bushing is small and gaps exist between the cylinder and the bushing in the process of rapid movement of the moving contact, so that the cylinder leaks air is solved.

[0026] In a basic embodiment, as shown in Figure 1 The moving contact 1 is provided with a radial flange, and the bushing 3 is mounted on the flange of the moving contact 1 by bolts and tightly abuts against the flange. The moving contact 1 is in sliding seal with the cylinder 2 through the bushing 3. When the quick grounding switch is in the open position, the moving contact 1 moves upward, and the bushing 3 moves upward under the action of the moving contact 1. The cylinder 2 not only provides power for the movement of the moving contact 1, but also realizes the air suction function. At the same time, the area of the sealing surface between the cylinder 2 and the bushing 3 is large, and there will be no gap between the cylinder 2 and the bushing 3 during the rapid movement of the moving contact 1, which can cause the cylinder 2 to leak. When the air pressure in the cylinder 2 decreases, a negative pressure area is formed, thereby attracting external gas into the cylinder. This air suction function is particularly important in the arc extinguishing process, which can accelerate the flow of arc extinguishing gas and improve the arc extinguishing efficiency. At the same time, the air suction function also helps to cool the arc and protect the safety of the circuit and equipment. The movement of the cylinder 2 is closely matched with the movement of the moving contact 1, and they work together to complete the arc extinguishing operation. When the circuit needs to be disconnected, the moving contact 1 and the static contact quickly separate, generating an arc. The arc extinguishing gas at the opening of the end of the moving contact 1 is quickly sucked in, contacts the arc and cools it, thereby extinguishing the arc. The cylinder 2 is usually made of high-strength and corrosion-resistant materials, which can maintain stable performance in harsh working environments. In addition, the sealing performance of the cylinder is also very important, which can prevent gas leakage and ensure that the moving contact 1 maintains stable air suction effect during long-term operation.

[0027] In a preferred embodiment, a guide sleeve 4 is provided at the lower end of the cylinder 2, and the sliding seal between the lower end of the cylinder 2 and the moving contact 1 is realized through the guide sleeve 4. At the same time, the guide sleeve 4 can also guide the moving contact 1, so that the moving contact 1 does not tilt during the up-and-down movement. In other embodiments, the number of guide sleeves 4 can be multiple, which can further ensure the sliding seal between the lower end of the cylinder 2 and the moving contact 1 while guiding the moving contact 1. One or more sliding seal rings can also be provided between the moving contact 1 and the lower end of the cylinder 2, and the sliding seal between the moving contact 1 and the cylinder 2 is realized through the sliding seal ring.

[0028] In a preferred embodiment, a spring contact finger 5 is arranged at the lower end of the cylinder 2, the spring contact finger 5 is arranged between the cylinder 2 and the movable contact 1, and the spring contact finger 5 is arranged below the guide sleeve 4. The spring contact finger has unique elastic force and deformation characteristics, and can maintain stable contact in a vibrating or dynamic environment, thereby ensuring the stability and reliability of the circuit. The spring contact finger 5 is arranged between the cylinder 2 and the movable contact 1, which can ensure the electrical connection between the movable contact 1 and the cylinder 2. Meanwhile, the spring contact finger 5 can be used in cooperation with the arc extinguishing chamber to enhance the arc extinguishing effect. When the movable contact 1 and the static contact 13 are disconnected, the spring contact finger can quickly separate, which can reduce the generation and duration of the electric arc. In cooperation with the arc extinguishing gas in the arc extinguishing chamber, the electric arc can be more effectively cooled and extinguished, which can prevent the insulation breakdown phenomenon at the disconnection part of the movable contact 1 and the static contact 13, thereby protecting the safety of the circuit and the equipment. Meanwhile, due to the elastic deformation capability of the spring contact finger, the spring contact finger can adapt to the tolerances and assembly errors of the contact surface, which can make the suction gas movable contact more flexible during the manufacturing and installation process, and reduce the machining precision and assembly precision of the movable contact 1. In other embodiments, the number of spring contact fingers 5 can be one or more.

[0029] The working principle of the spring contact finger is to use the elastic deformation of the metal spring to realize the contact and disconnection of the circuit. The spring contact finger usually consists of a fixed part and a movable part. The fixed part is connected to the power line, and the movable part is connected to the load line. When the movable part is compressed and deformed by external force, the contact point of the spring contact finger is closed, and the circuit path is formed. When the external force disappears, the spring returns to its original state, the contact point is disconnected, and the circuit is interrupted. The spring contact finger 5 has the characteristic of multi-point contact. Each spring ring can act as a contact point, and when the current passes through, the current can be dispersed to multiple contact points, thereby reducing the current density of each contact point, reducing the contact resistance, and improving the conductivity. The spring contact finger is usually made of materials with high elasticity, high wear resistance and high conductivity, so that the spring contact finger can be used stably for a long time.

[0030] In a preferred embodiment, a middle through hole 6 is formed in the movable contact 1, and a gas hole 7 is arranged on the outer wall of the movable contact 1. During the opening process, the closed space formed by the bushing 3 and the cylinder 2 gradually increases. Due to the pressure difference, the gas enters the inside of the cylinder 2 through the middle through hole 6 of the movable contact 1 and the gas hole 7 on the outer wall of the movable contact 1, and forms a gas flow at the disconnection part of the movable contact 1 and the static contact 13, which carries away the heat and metal particles of the electric arc, and fills the low-temperature environment-friendly gas around the disconnection part to the opening of the movable contact 1, thereby achieving arc extinguishing. In other embodiments, the number of gas holes 7 can be multiple, so that the gas flow can enter the cylinder 2 more quickly, thereby achieving better arc extinguishing effect.

[0031] In a preferred embodiment, the bushing 3 is bolted to the side of the convex edge of the moving contact 1 facing away from the inside of the cylinder 2, and the moving contact 1 is directly subjected to the force of the bolt during the opening process, and the bushing 3 is not directly subjected to the force of the bolt, and the force area between the bushing 3 and the moving contact is large, and the problem of cracking of the bushing due to force concentration does not easily occur. In other embodiments, as shown in Figure 2 the bushing 3 can be bolted to the side of the convex edge of the moving contact 1 facing the inside of the cylinder 2, and the moving contact 1 is in sliding sealing cooperation with the cylinder 2 through the bushing 3, and during the opening process, the moving contact 1 moves upward, and the bushing 3 moves upward under the driving of the bolt, and when the moving contact moves upward, the gas outside the contact enters the cylinder through the lumen of the moving contact, and a gas flow is formed at the opening at the end of the moving contact, and the arc heat and metal particles are carried away, and arc extinguishing is achieved, and the problem of insulation breakdown at the breaking point of the moving contact and the static contact is prevented.

[0032] As shown in Figure 3 , 4 the quick grounding switch of the utility model is provided with a bracket 10 and a support 11 in the cylinder 9, the moving contact 1 is installed on the bracket 10, the cylinder 2 is fixedly installed on the support 11 through a bolt, the other end of the support 11 is installed on the grounding insulator 12 in the cylinder 9, the moving contact 1 cooperates with the cylinder 2, and the static contact 13 is installed below the cylinder 2. During the opening process, the moving contact 1 moves upward, and the closed space formed between the bushing 3 and the cylinder 2 gradually increases, and when the air pressure in the cylinder 2 decreases, a negative pressure area can be formed, thereby attracting the external gas into the cylinder, and this gas suction function is particularly important in the arc extinguishing process, can accelerate the flow of arc extinguishing gas, and improve the arc extinguishing efficiency. At the same time, the gas suction function is also helpful for cooling the arc, and protects the safety of the circuit and the equipment. The bushing 3 is bolted to the upper side of the moving contact 1, and when the moving contact 1 moves upward during the opening process, the force of the bolt directly acts on the moving contact, and the bushing 3 will not crack due to force concentration, and at the same time, the space between the moving contact and the cylinder is closed, and even if metal particles are generated due to friction between the moving contact and the bolt, the metal particles will fall into the cylinder, and will not affect the performance of the switch, and at the same time, one side of the bushing 3 is closely attached to the side wall of the convex edge of the moving contact, and the length of the bushing 3 is not limited by the length of the convex edge, and the sealing surface area between the bushing 3 and the cylinder 2 can be increased, so that the bushing 3 and the cylinder 2 can not have a gap even in the case of rapid movement of the moving contact, and can be closely attached at all times, so that the cylinder 2 will not have a gas leakage problem, and good arc extinguishing effect is ensured.

[0033] The above is only a preferred embodiment of the utility model, and is not used to limit the utility model, and the patent protection scope of the utility model is subject to the claims, and equivalent structural changes made according to the contents of the specification and the drawings of the utility model should also be included in the protection scope of the utility model.

Claims

1. A movable contact having an air intake structure, comprising an air cylinder, the air cylinder being fitted to the outside of the movable contact, characterized in that, The moving contact is provided with a radial flange, and a L-shaped bushing is arranged on the flange, one side of the bushing is tightly fitted with the end surface of the flange, and the other side is tightly fitted with the side wall of the flange, and the bushing is in sliding sealing fit with the cylinder.

2. The movable contact with an air intake structure according to claim 1, characterized in that A guide sleeve is arranged between the moving contact and the lower end of the cylinder, and the moving contact and the lower end of the cylinder are in sliding sealing fit through the guide sleeve.

3. The movable contact with an air intake structure according to claim 1 or 2, characterized in that A spring contact finger is arranged between the lower end of the cylinder and the moving contact.

4. The movable contact with an air intake structure according to claim 1 or 2, characterized in that The moving contact is provided with a middle through hole, and air holes are arranged on the side wall of the moving contact.

5. The movable contact with an air intake structure according to claim 1 or 2, characterized in that, The bushing is fixedly installed on the side of the flange away from the inside of the cylinder.

6. A fast grounding switch comprising a cylinder, a bracket is arranged in the cylinder, a movable contact is mounted on the bracket, the movable contact comprises a cylinder, the cylinder is sleeved outside the movable contact, characterized in that, The moving contact is provided with a radial flange, and a L-shaped bushing is arranged on the flange, one side of the bushing is tightly fitted with the end surface of the flange, and the other side is tightly fitted with the side wall of the flange, and the bushing is in sliding sealing fit with the cylinder.

7. The fast ground switch of claim 6, wherein, A guide sleeve is arranged between the moving contact and the lower end of the cylinder, and the moving contact and the lower end of the cylinder are in sliding sealing fit through the guide sleeve.

8. The fast ground switch according to claim 6 or 7, characterized in that A spring contact finger is arranged between the lower end of the cylinder and the moving contact.

9. The fast ground switch according to claim 6 or 7, characterized in that The moving contact is provided with a middle through hole, and air holes are arranged on the side wall of the moving contact.

10. The fast ground switch according to claim 6 or 7, characterized in that The bushing is fixedly installed on the side of the flange away from the inside of the cylinder.

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