Arc extinguishing mechanism of circuit breaker

Abstract

The utility model discloses an arc extinguishing mechanism of a circuit breaker, which comprises a circuit breaker mounting seat, the upper surface of the circuit breaker mounting seat is fixedly connected with three groups of closing mechanisms, and arc blowing mechanisms are arranged in the closing mechanisms; the switching-on mechanism comprises a base, an input pole fixed on the rear side of the upper surface of the base and an output pole fixed on the front side of the upper surface of the base, a switching-on knife switch is hinged to the top end of the output pole, and a contact is connected to the top end of the input pole; the arc blowing mechanism comprises a gas box and a gas conveying assembly fixed to the upper surface of the gas box. According to the technical scheme, mixed gas of sulfur hexafluoride and nitrogen is adopted for arc extinguishing, the sulfur hexafluoride gas has strong electronegativity, so that free electrons in electric arcs are efficiently adsorbed, the nitrogen serves as buffer gas, the decomposition temperature of the sulfur hexafluoride is reduced, the thermal stability is improved, and the balance of arc extinguishing efficiency and environmental protection performance is achieved; the problem of arc reignition easily occurring in traditional air arc extinguishing in an outdoor humid environment is solved.

Description

TECHNICAL FIELD

[0001] The utility model relates to circuit breaker arc extinguishing apparatus technical field, specifically related to a circuit breaker's arc extinguishing mechanism. BACKGROUND

[0002] In the power system, as the key protection equipment, the arc extinguishing performance of circuit breaker is directly related to the stability and safety of the power system. The traditional circuit breaker arc extinguishing technology mainly uses air, oil or vacuum as arc extinguishing medium, but these methods have certain limitations. For example, air arc extinguishing is easily affected by environmental humidity, temperature and other factors, and arc reignition phenomenon easily occurs in outdoor humid environment, resulting in low arc extinguishing efficiency; although oil circuit breaker has good arc extinguishing effect, it has fire hazard and environmental pollution problems; although vacuum circuit breaker operates rapidly, overvoltage is easily generated when breaking inductive load, and additional protection device is needed.

[0003] With the continuous development of power technology, sulfur hexafluoride gas is widely used in circuit breakers due to its excellent insulation performance and arc extinguishing ability. Sulfur hexafluoride gas has strong electronegativity and can efficiently adsorb free electrons in arc, thereby rapidly extinguishing arc. However, pure sulfur hexafluoride gas is easily decomposed at high temperature, producing toxic substances, and it has a great impact on the environment as a strong greenhouse gas. Moreover, in outdoor humid environment, traditional air arc extinguishing technology is easily affected by environmental factors, leading to frequent arc reignition problems. Therefore, according to the above-mentioned viewpoints, the technical personnel in the art provide a scheme for solving the arc extinguishing mechanism of circuit breaker. SUMMARY

[0004] The purpose of the utility model is to provide a technical scheme for the arc extinguishing mechanism of circuit breaker to solve the deficiencies mentioned in the background technology. In order to solve the drawbacks and defects described in the background technology, the technical scheme has the following contents:

[0005] It comprises a circuit breaker mounting seat, the upper surface of the circuit breaker mounting seat is fixedly connected with three sets of closing mechanism, the inside of the closing mechanism is provided with an arc blowing mechanism;

[0006] The closing mechanism comprises a base, an input pole column fixed on the rear side of the upper surface of the base, and an output pole column fixed on the front side of the upper surface of the base, the top end of the output pole column is hinged with a closing contactor, and the top end of the input pole column is connected with a contact;

[0007] The arc blowing mechanism comprises a gas tank and a gas delivery assembly fixed on the upper surface of the gas tank, wherein the gas suction end of the gas delivery assembly is connected with a gas suction pipe penetrating into the inside of the gas tank, the gas exhaust end of the gas delivery assembly is connected with a gas delivery pipe, and the end of the gas delivery pipe faces the closing area of the closing contactor and the contact;

[0008] The gas conveying assembly comprises a shell, a crankshaft rotatably arranged in the inner cavity of the shell, a connecting rod piston rotatably connected to the crankpin of the crankshaft, and two piston cylinders embedded in the shell and into which the connecting rod piston is inserted, and the outer end of each of the piston cylinders is provided with an inlet and outlet gas port, wherein the outlet gas port of the left piston cylinder is connected to the inlet gas port of the right piston cylinder through a connecting pipe, the outlet gas port of the right piston cylinder is connected to a gas conveying pipe, and the inlet gas port of the left piston cylinder is connected to a gas extraction pipe.

[0009] As a preferred scheme of the utility model, the bottom surface of the base is fixedly connected to the top surface of the circuit breaker mounting seat, the bottom surface of the gas tank is fixedly connected to the middle position of the top surface of the base between the input pole and the output pole.

[0010] As a preferred scheme of the utility model, the inside of the gas tank is filled with mixed gas of sulfur hexafluoride gas and nitrogen gas, and the rear side wall of the gas tank is provided with a gas injection port.

[0011] As a preferred scheme of the utility model, the end of the gas conveying pipe away from the port of the gas conveying assembly is connected with an arc-shaped pipe through a pipe joint, and the end of the arc-shaped pipe is connected with a nozzle, wherein the outer ring surface of the arc-shaped pipe is connected to the side wall of the closing contactor through a clamp, and the gas outlet port of the nozzle faces the closing contact end of the closing contactor.

[0012] As a preferred scheme of the utility model, the rear end face of the shell is connected with an end cover through a screw, the left side wall and the top surface of the shell are provided with a round hole for the piston cylinder to penetrate and fix, the bottom surface of the shell is fixedly connected with a bottom plate, and the bottom end face of the bottom plate is fixedly connected to the top surface of the gas tank.

[0013] As a preferred scheme of the utility model, the front end of the crankshaft is rotatably connected to the side wall of the inner cavity of the shell, and the rear end of the crankshaft penetrates the end cover.

[0014] As a preferred scheme of the utility model, a servo motor is mounted on the front side of the top surface of the gas tank, the output shaft of the servo motor is connected to the end of the crankshaft penetrating the rear side of the end cover through a shaft coupling.

[0015] As a preferred scheme of the utility model, the gas extraction port of the left piston cylinder is connected with an air inlet pipeline, the end of the air inlet pipeline is connected to the end of the gas extraction pipe away from the gas tank, the gas exhaust port of the right piston cylinder is connected with an air supply pipeline, and the end of the air supply pipeline is connected to the end of the gas conveying pipe away from the arc-shaped pipe.

[0016] As a preferred scheme of the utility model, the inside of the gas feeding pipeline and the inside of the gas inlet pipeline are both provided with a one-way valve, wherein the one-way valve in the gas inlet pipeline controls the gas to enter the piston cylinder, and the one-way valve in the inside of the gas feeding pipeline controls the gas to flow out from the inside of the piston cylinder.

[0017] In the above technical scheme, the utility model provides technical effects and advantages:

[0018] The technical scheme adopts the mixed gas of sulfur hexafluoride and nitrogen to extinguish arc, the sulfur hexafluoride gas has strong electronegativity, thereby efficiently adsorbing free electrons in the arc, the nitrogen gas is used as buffer gas to reduce the decomposition temperature of the sulfur hexafluoride, improve thermal stability, realize the balance of arc extinguishing efficiency and environmental protection, and solve the problem of arc reignition of the traditional air arc extinguishing in the outdoor humid environment. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the technical scheme in the embodiments or prior art, the drawings needed in the embodiments will be briefly introduced as follows, and obviously, the drawings in the following description are only some embodiments in the utility model, and other drawings can be obtained by those skilled in the art according to these drawings.

[0020] Figure 1 It is the overall structure schematic diagram of the pole-mounted circuit breaker;

[0021] Figure 2 It is the schematic diagram of the closing mechanism;

[0022] Figure 3 It is the schematic diagram of the mixed gas arc blowing mechanism;

[0023] Figure 4 It is the gas conveying assembly schematic diagram in the arc blowing mechanism.

[0024] ATTACHMENT Figure 1 -ATTACHMENT Figure 4 The various marks in the drawings are explained as follows:

[0025] 1, circuit breaker mounting seat;

[0026] 2, closing mechanism; 21, base; 22, input pole; 23, contact; 24, closing knife; 25, output pole;

[0027] 3, arc blowing mechanism; 31, gas tank; 33, gas conveying pipe; 34, nozzle; 35, arc-shaped pipe; 36, gas suction pipe;

[0028] 32, gas conveying assembly; 321, shell; 322, bottom plate; 323, connecting rod piston; 324, gas inlet pipeline; 325, connecting pipe; 326, end cover; 327, gas feeding pipeline; 328, piston cylinder; 329, crankshaft. DETAILED DESCRIPTION

[0029] In order to make the technical scheme and implementation mode of the utility model clearer and more understandable, the following introduces several preferred embodiments for implementing the technical scheme of the utility model.

[0030] The following description is merely exemplary in nature and is not intended to limit the disclosure, application and uses. It should be understood that throughout the drawings, the same or similar reference numerals can indicate the same or similar parts and features. The various drawings only schematically represent the concepts and principles of the embodiments of the disclosure, and do not necessarily show the specific dimensions and their proportions of the various embodiments of the disclosure. In particular parts of the specific drawings, the relevant details or structures of the embodiments of the disclosure can be exaggerated to illustrate the concepts of the embodiments of the disclosure. The disclosures of the various publications, patents and published patent specifications cited herein are hereby incorporated by reference in their entirety. The technical scheme of the utility model will be described clearly and completely in the following with respect to the embodiments of the utility model. Obviously, the described embodiments are only a part of the embodiments of the utility model.

[0031] An arc extinguishing mechanism of a circuit breaker comprises the following: a circuit breaker mounting seat 1 is a metal frame structure, the top plane of which is fixed with three groups of closing mechanisms 2 arranged horizontally, each of which is internally integrated with an independently working arc blowing mechanism 3, which can simultaneously perform arc extinguishing operation on multi-phase circuits,

[0032] The base 21 is made of high-strength insulating ceramic, the bottom of which is rigidly connected with the circuit breaker mounting seat 1 through a flange, the rear side of the upper surface of the base is vertically installed with an input pole 22, and the front side is installed with an output pole 25, the top end of the input pole 22 is provided with a copper contact 23, the surface of which is silver-plated to reduce the contact resistance, and the top of the output pole 25 is hingedly connected with a closing contact 24 through a rotating bearing, the closing contact adopts a lamination structure and forms a surface contact with the contact 23 when closed.

[0033] The gas tank 31 is a sealed stainless steel container fixed at the central position of the base 21, the inside of which is filled with a mixed gas of sulfur hexafluoride and nitrogen gas in a volume ratio of 7:3, the rear wall of the gas tank is provided with a gas injection port with a solenoid valve, online gas supplement can be performed, the end of the exhaust pipe 36 extends to the bottom of the gas tank 31, ensuring that high-pressure gas is extracted, the gas conveying pipe 33 is made of high-temperature resistant silica gel pipe, the end of which is connected with an arc-shaped pipe 35 through a pipe joint, the arc-shaped pipe 35 extends along the back of the closing contact 24 and is fixed through a stainless steel clamp, the end of which is installed with a tungsten-copper alloy nozzle 34, the spraying angle of which is accurately aligned with the contact surface of the contact 23 and the closing contact 24.

[0034] In the gas delivery assembly 32, the shell 321 is an aluminum alloy cast box, the bottom is welded and sealed with the gas tank 31 through a bottom plate 322, two copper piston cylinders 328 are installed horizontally and side by side, the left piston cylinder is connected with the air suction pipe 36 through an air inlet pipeline 324, the right side is connected with the gas delivery pipe 33 through a gas feeding pipeline 327, the crankshaft 329 is installed on the shell 321 through ball bearings at both ends, the crankshaft 329 is hinged with two connecting rods 323 with a phase difference of 180° at the crank neck, and the connecting rods 323 are inserted into the left and right piston cylinders respectively, a servo motor installed on the top of the gas tank 31 drives the crankshaft 329 through a shaft coupling, wherein the piston cylinder 328 is fixed with the shell 321 through interference fit, the contact surface is coated with sealing glue, the left and right piston cylinders are connected in series through a connecting pipe 325 to form a compression structure; a one-way valve is installed in the air inlet pipeline 324 and the gas feeding pipeline 327 to ensure one-way flow of the gas, an O-shaped sealing ring is arranged between the end cover 326 and the shell 321, and a mechanical seal structure is arranged at the penetrating position of the crankshaft 329.

[0035] According to the above-mentioned preferred technical scheme, the working process of the technical scheme is described:

[0036] The circuit breaker mounting seat 1 remains fixed, the three closing mechanisms 2 are in a normally closed state, the crankshaft 329 of the gas delivery assembly 32 is in an initial position, the piston cylinder 328 stores mixed gas in advance, the sensor continuously monitors the current values of the input pole 22 and the output pole 25, and the pressure inside the gas tank 31, when a sudden change in current is monitored and exceeds a threshold value, the control unit sends a trigger signal to the servo motor, the servo motor drives the crankshaft 329 to rotate, and drives the connecting rod piston 323 to reciprocate in the piston cylinder 328, the piston movement generates compressed gas, the one-way valve is opened to make the gas enter the gas delivery pipe 33, the gas is guided to the nozzle 34 through the arc-shaped pipe 35 to form a pre-injection state, the nozzle 34 is directed to the arc position, the high-speed gas flow impacts the arc area, the SF6 and nitrogen components in the gas act on the arc, absorb energy and accelerate the cooling of the arc, the arc between the closing contact 24 and the contact 23 disappears under the impact of the gas, the surface of the contact 23 remains low temperature under the cooling action of the gas, and the ablation is reduced, the spring mechanism drives the closing contact 24 to reset, and fresh gas is supplied to the gas tank 31 for the next operation.

[0037] The above only describes some exemplary embodiments of the present application by way of illustration, without doubt, for ordinary skilled in the art, without departing from the spirit and scope of the present application, the described embodiments can be modified in various ways. Therefore, the above description and drawings are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present application.

Claims

1. An arc extinguishing mechanism of a circuit breaker comprising a circuit breaker mounting base (1), characterized in that: The upper surface of the circuit breaker mounting seat (1) is fixedly connected with three sets of closing mechanisms (2), and the inside of each closing mechanism (2) is provided with an arc blowing mechanism (3); The closing mechanism (2) comprises a base (21), an input pole (22) fixed to the rear side of the upper surface of the base (21), and an output pole (25) fixed to the front side of the upper surface of the base (21), and the top end of the output pole (25) is hingedly connected with a closing contact (24), and the top end of the input pole (22) is connected with a contact (23); The arc blowing mechanism (3) comprises a gas tank (31), a gas delivery assembly (32) fixed to the upper surface of the gas tank (31), wherein the gas suction end of the gas delivery assembly (32) is connected with a gas suction pipe (36) penetrating into the inside of the gas tank (31), the gas discharge end of the gas delivery assembly (32) is connected with a gas delivery pipe (33), and the distal end of the gas delivery pipe (33) faces the closing area of the closing contact (24) and the contact (23); The gas delivery assembly (32) comprises an outer shell (321), a crankshaft (329) rotationally arranged in the inner cavity of the outer shell (321), a connecting rod piston (323) rotationally connected to the crank neck of the crankshaft (329), and two piston cylinders (328) in which the connecting rod piston (323) is inserted are embedded in the inside of the outer shell (321), and the outer side end of each of the piston cylinders (328) is provided with an inlet and outlet port, wherein the outlet port of the left piston cylinder (328) is connected with the inlet port of the right piston cylinder (328) through a connecting pipe (325), the outlet port of the right piston cylinder (328) is connected with the gas delivery pipe (33), and the inlet port of the left piston cylinder (328) is connected with the gas suction pipe (36).

2. An arc quenching mechanism for a circuit breaker according to claim 1, characterized in that: The bottom surface of the base (21) is fixedly connected with the top surface of the circuit breaker mounting seat (1), and the bottom surface of the gas tank (31) is fixedly connected to the middle position of the top surface of the base (21) between the input pole (22) and the output pole (25).

3. An arc extinguishing mechanism for a circuit breaker according to claim 1, characterized in that: The inside of the gas tank (31) is compressedly filled with a mixed gas of sulfur hexafluoride gas and nitrogen gas, and the rear side wall of the gas tank (31) is provided with a gas injection port.

4. An arc extinguishing mechanism for a circuit breaker according to claim 1, characterized in that: The port of the gas delivery pipe (33) away from the gas delivery assembly (32) is connected with an arc-shaped pipe (35) through a pipe joint, and the distal end of the arc-shaped pipe (35) is connected with a nozzle (34) penetratingly, wherein the outer ring surface of the arc-shaped pipe (35) is connected with the side wall of the closing contact (24) through a hoop, and the gas outlet port of the nozzle (34) faces the closing contact end of the closing contact (24).

5. An arc extinguishing mechanism for a circuit breaker according to claim 1, characterized in that: The rear end face of the outer shell (321) is connected with an end cover (326) through screws, the left side wall and the top surface of the outer shell (321) are both provided with a round hole through which the piston cylinder (328) penetrates and is fixed, and the bottom surface of the outer shell (321) is fixedly provided with a bottom plate (322), and the bottom end face of the bottom plate (322) is fixedly connected with the top surface of the gas tank (31).

6. An arc extinguishing mechanism for a circuit breaker according to claim 1, characterized in that: The front end of the crankshaft (329) is rotatably connected to the side wall of the inner cavity of the shell (321), and the rear end of the crankshaft (329) penetrates through the end cover (326).

7. An arc extinguishing mechanism for a circuit breaker according to claim 1, characterized in that: A servo motor is mounted on the front side of the top surface of the gas tank (31), and the output shaft of the servo motor is connected to the end of the crankshaft (329) penetrating through the rear side of the end cover (326) through a shaft coupling.

8. The arc extinguishing mechanism of a circuit breaker according to claim 1, characterized in that: The suction port of the left piston cylinder (328) is connected with an air inlet pipeline (324), and the end of the air inlet pipeline (324) is connected with the end of the air suction pipe (36) away from the gas tank (31); the exhaust port of the right piston cylinder (328) is connected with an air outlet pipeline (327), and the end of the air outlet pipeline (327) is connected with the end of the gas conveying pipe (33) away from the arc-shaped pipe (35).

9. An arc extinguishing mechanism for a circuit breaker according to claim 8, characterized in that: The inside of the air outlet pipeline (327) and the inside of the air inlet pipeline (324) are both provided with a one-way valve, wherein the one-way valve in the air inlet pipeline (324) controls the gas to enter the piston cylinder (328), and the one-way valve in the air outlet pipeline (327) controls the gas to flow out of the piston cylinder (328).

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