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CN-121983449-A - Circuit breaker with high breaking capacity

CN121983449ACN 121983449 ACN121983449 ACN 121983449ACN-121983449-A

Abstract

The application relates to the technical field of circuit breakers and discloses a circuit breaker with high breaking capacity, which comprises a shell, a moving contact, a fixed contact and an arc extinguishing device, wherein the moving contact, the fixed contact and the arc extinguishing device are arranged in the shell, the arc extinguishing device comprises a U-shaped arc extinguishing grid sheet and an insulating plate arranged on the inner side of a U-shaped opening of the arc extinguishing grid sheet, the arc extinguishing grid sheet comprises a grid sheet substrate and two grid sheet feet arranged on the grid sheet substrate, the two insulating plates are oppositely arranged and are respectively positioned on one side, close to each other, of the two grid sheet feet, and the contact point of the moving contact and the fixed contact is positioned between the two insulating plates. When the circuit breaker breaks and generates an arc, the high-temperature arc can not directly burn the grid plate feet made of metal materials due to the isolation effect of the insulating plate, so that the arc extinguishing grid plate can continuously exert the electromagnetic suction and core functions of cutting the arc, the structural integrity of the arc extinguishing device after multiple breaking or oversized short-circuit current breaking is ensured, and the breaking capacity of the circuit breaker is improved.

Inventors

  • HUANG GUANGFA
  • Shu Hengyou
  • ZHOU YI
  • ZHAO FENG

Assignees

  • 温州华嘉电器有限公司

Dates

Publication Date
20260505
Application Date
20260331

Claims (8)

  1. 1. The circuit breaker with the high breaking capacity comprises a shell (1), a moving contact (11), a fixed contact (12) and an arc extinguishing device (2) which are arranged in the shell (1), and is characterized in that the arc extinguishing device (2) comprises a U-shaped arc extinguishing grid sheet (21) and an insulating plate (25) arranged on the inner side of a U-shaped opening of the arc extinguishing grid sheet (21), the arc extinguishing grid sheet (21) comprises a grid sheet substrate (211) and two grid sheet feet (212) arranged on the grid sheet substrate (211), the insulating plate (25) is oppositely provided with two insulating plates and is respectively positioned on one side, close to each other, of the two grid sheet feet (212), and a contact point of the moving contact (11) and the fixed contact (12) is positioned between the two insulating plates (25).
  2. 2. The circuit breaker with high breaking capacity according to claim 1, wherein the arc extinguishing device (2) further comprises a first arc isolating cover (22) and a second arc isolating cover (23), the first arc isolating cover (22) and the second arc isolating cover (23) are detachably connected, a grid sheet groove (221) is formed in the first arc isolating cover (22), a grid sheet foot (212) is arranged in the grid sheet groove (221), a stop block (231) is arranged on the second arc isolating cover (23), and when the first arc isolating cover (22) and the second arc isolating cover (23) are connected together, the stop block (231) is located at an opening of the grid sheet groove (221), and an arc extinguishing chamber (24) for accommodating an arc extinguishing grid sheet (21) is formed in the first arc isolating cover (22) and the second arc isolating cover (23) together.
  3. 3. The circuit breaker with high breaking capacity according to claim 2, wherein the insulating plate (25) is arranged on the second arc isolating cover (23), the insulating plate (25), the stop block (231) and the second arc isolating cover (23) are jointly formed with a fixed slot (251) for extending the gate sheet pins (212), and each arc extinguishing gate sheet (21) is arranged in an arc shape along the breaking track of the moving contact (11).
  4. 4. The breaker with high breaking capacity according to claim 2, wherein the first arc isolation cover (22) is provided with an air outlet (222), one end of the fixed contact (12) far away from the moving contact (11) is connected with a binding post (121), the binding post (121) is located on the outer side of the first arc isolation cover (22), the air outlet (222) is staggered with the binding post (121), the first arc isolation cover (22) is provided with insulating paper (223), and the insulating paper (223) can shield the air outlet (222).
  5. 5. A circuit breaker with high breaking capacity according to claim 1, characterized in that the arc chute sheet (21) on one side of the stationary contact (12) comprises two layers of arc chute sheets (213).
  6. 6. A circuit breaker with high breaking capacity according to claim 1, characterized in that the arc extinguishing gate (21) far from the stationary contact (12) is provided with an arc striking angle (214), which arc striking angle (214) is used for guiding the arc close to the arc extinguishing gate (21).
  7. 7. The breaker with high breaking capacity according to claim 2, wherein the shell (1) is provided with a limiting groove (13), the first arc-isolating cover (22) and the second arc-isolating cover (23) are respectively provided with a limiting block (232), and the limiting blocks (232) extend into the limiting groove (13).
  8. 8. The circuit breaker with high breaking capacity according to claim 7, wherein the first arc isolating cover (22) and the limiting block (232) are integrally formed, and the second arc isolating cover (23) and the stop block (231), the insulating plate (25) and the limiting block (232) are integrally formed.

Description

Circuit breaker with high breaking capacity Technical Field The application relates to the technical field of circuit breakers, in particular to an arc extinguishing device of a circuit breaker. Background A circuit breaker is a key switching device for switching on, carrying and off a current under normal loop conditions and for switching on, carrying and off a current under abnormal loop conditions for a prescribed time. The circuit breaker may be classified into a high voltage circuit breaker and a low voltage circuit breaker according to a range of use. Among them, a high-voltage circuit breaker is generally required to have a high breaking capacity, i.e., a capacity to safely and reliably cut off a maximum fault current when a fault such as a short circuit occurs. This capability is a core indicator for measuring the performance of the circuit breaker, and is directly related to the safe and stable operation of the smart grid system. Existing circuit breakers generally include a housing, and a moving contact, a stationary contact, and an arc extinguishing device disposed within the housing. The arc extinguishing device consists of two opposite arc separating walls and a plurality of arc extinguishing bars arranged between the arc separating walls. The arc extinguishing grid sheet is generally designed into a U-shaped structure to increase the heat dissipation area and enhance the arc extinguishing effect. The moving contact and the fixed contact are both positioned between the two arc separation walls and are arranged in the U-shaped openings of the arc extinguishing grid plates, and the U-shaped openings of the U-shaped arc extinguishing grid plates are combined to form a track for moving the moving contact. When the circuit breaks down and needs to be broken, the moving contact moves to the side far away from the fixed contact, an arc generated between the moving contact and the fixed contact is lengthened along with the movement of the moving contact, and then the moving contact is divided into a plurality of short arcs by the arc extinguishing grid sheet, so that the voltage of the arc is gradually reduced, and finally, the extinction is realized. However, the prior art has obvious defects in practical application. When the breaker breaks to generate an arc, the arc contacts the grid pins at first because the arc is nearest to the grid pins at two sides of the U-shaped opening of the arc extinguishing grid. Since the width of the grid foot is usually smaller, the grid foot is extremely easy to be ablated and damaged under the action of an initial strong arc. Once the grid feet are damaged, the arc cannot be split and extinguished in time, and even the whole arc extinguishing device and the breaker can be burnt out. Particularly, a breaker with high breaking capacity is affected, so that a great potential safety hazard exists when the breaker is used for dealing with a large current fault, and improvement is needed. Disclosure of Invention In order to improve breaking capacity of a circuit breaker, the application provides the circuit breaker with high breaking capacity. The application provides a circuit breaker with high breaking capacity, which adopts the following technical scheme: the utility model provides a circuit breaker with high breaking capacity, includes the casing, sets up moving contact, stationary contact and the arc extinguishing device in the casing, the arc extinguishing device includes the arc extinguishing bars piece of U-shaped and sets up the inboard insulation board of U-shaped opening at the arc extinguishing bars piece, the arc extinguishing bars piece includes bars piece base plate and sets up two bars piece feet on bars piece base plate, the insulation board is provided with two relatively and is located two bars piece feet respectively and is close to one side each other, the contact point of moving contact and stationary contact is located between two insulation boards. By adopting the technical scheme, when the breaker breaks to generate an arc, the high-temperature arc cannot be directly burnt to the grid pins made of metal materials due to the isolation effect of the insulating plate. The insulating plate can bear the instantaneous high temperature of the electric arc, so that the deformation or melting of the grid plate feet caused by ablation is avoided, the arc extinguishing grid plate can continuously exert the electromagnetic suction and the core function of dividing the electric arc, and the electric arc can be smoothly introduced into the deep part of the grid plate for division and cooling. The protection capability of the core structure of the arc-extinguishing gate sheet is improved, the structural integrity of the arc-extinguishing device after repeated breaking or oversized short-circuit current breaking is ensured, and the service life of the circuit breaker is greatly prolonged. Simultaneously, the slits formed by the two insulating plates have arc gath