US-12620536-B2 - Circuit breaking unit and air circuit breaker including same

US12620536B2US 12620536 B2US12620536 B2US 12620536B2US-12620536-B2

Abstract

A circuit breaking unit includes a fixed contact, a movable contact in contact with or spaced apart from the fixed contact, a fixed contact terminal having the fixed contact disposed at a lower end thereof and extending upward, a movable contact terminal on which the movable contact is disposed and configured such that the movable contact moves in a direction toward the fixed contact or in a direction away from the fixed contact, and a low runner disposed extending upward from the fixed contact, one end thereof coupled to the fixed contact terminal, and the other end thereof spaced apart from the fixed contact terminal, wherein a magnet unit or a U assembly is disposed between the low runner and the fixed contact terminal.

Inventors

Yong Ik PARK
Han Baek CHUNG

Assignees

LS ELECTRIC CO., LTD.

Dates

Publication Date: 20260505
Application Date: 20220429
Priority Date: 20210514

Claims (20)

1 . A circuit breaking unit, comprising: a fixed contact; a movable contact that is in contact with or spaced apart from the fixed contact; a protruding contact spaced apart from the movable contact; a fixed contact terminal having the fixed contact disposed at a lower end thereof and extending upward; a movable contact terminal on which the movable contact is disposed and configured such that the movable contact moves in a direction toward the fixed contact or in a direction away from the fixed contact; a low runner disposed extending in a direction away from the fixed contact, one end thereof coupled to the fixed contact terminal, and the other end thereof spaced apart from the fixed contact terminal; a holder disposed between the low runner and the fixed contact terminal, extending away from the fixed contact terminal, extending toward the movable contact, having a space formed therein, and protruding from both sides of the low runner; and a U magnetic body stored in an inner space of the holder and made of a permanent magnet, wherein the holder is formed to extend to both sides of the low runner so that when an arc is generated in an arc-generation area, a pressure applied to the arc is increased as the arc-generation area is reduced by an air gap formed between the protruding contact and the holder, and wherein the U magnetic body comprises a magnet unit disposed to be extending from the fixed contact terminal between the protruding contact and an arc extinguishing unit disposed above the protruding contact, and disposed to face each other.
2 . The circuit breaking unit of claim 1 , further comprising a fixing part coupled to the holder and the fixed contact terminal so that the holder is not separated from the fixed contact terminal and the U magnetic body is not separated from the inner space.
3 . The circuit breaking unit of claim 2 , wherein the U magnetic body further comprises: an insulator interposed between the low runner and the fixed contact terminal and disposed between the magnet unit.
4 . The circuit breaking unit of claim 3 , wherein the magnet unit is disposed such that surfaces facing each other have different polarities.
5 . The circuit breaking unit of claim 4 , wherein the magnet unit is disposed so that the arc generated during a trip mechanism of the movable contact and the fixed contact is subjected to an electromagnetic force toward the arc extinguishing unit.
6 . The circuit breaking unit of claim 2 , wherein the holder comprises a gassing material that generates molecules that extinguish the arc when heat generated by the arc is applied.
7 . The circuit breaking unit of claim 1 , wherein the protruding contact is disposed extending upward from the movable contact, energized when in contact with the low runner, and spaced apart from the low runner when the movable contact is tripped.
8 . The circuit breaking unit of claim 7 , wherein the protruding contact extends upward so as to overlap at least a portion of a side plate of the arc extinguishing unit.
9 . The circuit breaking unit of claim 8 , wherein the holder extends between the arc extinguishing unit and the protruding contact from both sides of the low runner.
10 . The circuit breaking unit of claim 9 , wherein the holder extends to surround a side surface of the protruding contact when the protruding contact is disposed in a trip state.
11 . The circuit breaking unit of claim 10 , wherein the air gap is a separation space.
12 . A circuit breaking unit, comprising: a fixed contact; a movable contact that is in contact with or spaced apart from the fixed contact; a protruding contact spaced apart from the movable contact; a fixed contact terminal having the fixed contact disposed at a lower end thereof and extending upward; a movable contact terminal on which the movable contact is disposed and configured such that the movable contact moves in a direction toward the fixed contact or in a direction away from the fixed contact; a low runner disposed extending in a direction away from the fixed contact, one end thereof coupled to the fixed contact terminal, and the other end thereof spaced apart from the fixed contact terminal; and a magnet unit disposed between the low runner and the fixed contact terminal and forming a magnetic field so that a generated arc is subjected to an electromagnetic force toward an arc extinguishing unit disposed above the protruding contact, and wherein the magnet unit comprises: a first surface magnetized to a N pole; and a second surface magnetized to a S pole, and wherein one of the first surface and the second surface of the magnet unit is disposed in a direction toward the fixed contact, and the other surface is disposed in a direction opposite to the one surface.
13 . The circuit breaking unit of claim 12 , wherein the first surface of the magnet unit is disposed in a direction toward the fixed contact, and the second surface is disposed in a direction opposite to the first surface.
14 . The circuit breaking unit of claim 12 , wherein the second surface of the magnet unit is disposed in a direction toward the fixed contact, and the first surface is disposed in a direction opposite to the second surface.
15 . The circuit breaking unit of claim 12 , further comprising a holder disposed between the low runner and the fixed contact terminal, extending away from the fixed contact terminal, extending toward the movable contact, having a space formed therein, and protruding from both sides of the low runner, wherein the holder is disposed under the magnet unit.
16 . The circuit breaking unit of claim 15 , wherein the holder is formed to extend to both sides of the low runner so that when an arc is generated, a pressure applied to the arc is increased.
17 . The circuit breaking unit of claim 15 , further comprising: a U magnetic body stored in the inner space of the holder and made of a ferromagnetic body; and a fixing part coupled to the holder and the fixed contact terminal so that the holder is not separated from the fixed contact terminal and the U magnetic body is not separated from the inner space.
18 . The circuit breaking unit of claim 17 , wherein the magnet unit is disposed inside the fixing part, and the low runner is disposed on a front surface of the magnet unit, and the fixed contact terminal is disposed on a rear surface of the magnet unit.
19 . The circuit breaking unit of claim 17 , wherein the U magnetic body comprises: a first magnetic body disposed to be extending from the fixed contact terminal between a protruding contact and an arc extinguishing unit disposed above the protruding contact; a second magnetic body spaced apart from the first magnetic body and disposed to face the first magnetic body; and a third magnetic body integrally formed with the first magnetic body and the second magnetic body and interposed between the low runner and the fixed contact terminal.
20 . The circuit breaking unit of claim 19 , wherein the first magnetic body, the second magnetic body, and the third magnetic body are formed by stacking magnetic bodies.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS The present application is a National Stage of International Application No. PCT/KR2022/006184 filed on Apr. 29, 2022, which claims priority to and the benefit of Korean Utility Model Application No. 10-2021-0062891, filed May 14, 2021, and Korean Utility Model Application No. 10-2021-0062894, filed May 14, 2021, the disclosures of which are incorporated herein by reference in its entirety. FIELD The present disclosure relates to a circuit breaking unit and an air circuit breaker including the same, and more particularly, to a circuit breaking unit capable of effectively extinguishing an arc generated by breaking an electric current and an air circuit breaker including the same. BACKGROUND A circuit breaker refers to a device capable of allowing or blocking energization with the outside by contacting and separating fixed contacts and movable contacts. A fixed contact and a movable contact provided in the circuit breaker are respectively connected energizably to an external power source or load. The movable contact is movably provided in the circuit breaker. The movable contact can be moved towards or away from the fixed contact. When the movable contact and the fixed contact come into contact to each other, the circuit breaker may be energizably connected to an external power source or load. When an overcurrent or abnormal current flows in the circuit breaker, the movable contact and the fixed contact in contact are spaced apart from each other. At this time, the current energized between the movable contact and the fixed contact does not immediately disappear, but changes into an arc form and extends along the movable contact. An arc can be defined as a flow of electrons at high temperature and high pressure. Therefore, when the generated arc stays in the inner space of the circuit breaker for a long time, there is a concern that each component of the circuit breaker may be damaged. In addition, when the arc is discharged to the outside of the circuit breaker without a separate treatment process, there is a risk of injury to the user. Accordingly, circuit breakers are generally provided with an extinguishing device for extinguishing and discharging an arc. The generated arc passes through the extinguishing device, the arc pressure is increased, the moving speed is increased, and it is cooled at the same time and can be discharged to the outside. Therefore, the generated arc must be quickly guided to an arc extinguishing device. However, in the case of a direct current air circuit breaker in which a small current flows among DC air breakers, the power of the generated arc is relatively weak. In addition, in the case of direct current, because zero point does not exist in the current, there is a problem in that arc extinguishing is more difficult than that of alternating current. In particular, since the power of the arc generated inside the DC air circuit breaker is relatively weak when a small current is broken, there is a problem in that the arc generated after the break is not moved to the grid of the arc extinguishing unit. The arc that has not been extinguished in this way stays adjacent to the movable contact and the fixed contact, causing problems such as melting the contact. Therefore, it is necessary to consider effectively extinguishing the arc generated when the small current is broken in the DC air circuit breaker. SUMMARY The present disclosure is directed to providing a circuit breaking unit having a structure capable of solving the above problems and an air circuit breaker including the same. First, the present disclosure is directed to providing a circuit breaking unit having a structure capable of quickly extinguishing and moving a generated arc and an air circuit breaker including the same. In addition, the present disclosure is directed to providing an arc extinguishing unit having a structure in which an arc generated when a small current is broken in a direct current air circuit breaker can quickly move to a grid and be extinguished, and an air circuit breaker including the same. In addition, the present disclosure is directed to providing a circuit breaking unit having a structure in which a magnet forming a magnetic field associated with an arc movement path is not damaged by an arc, and an air circuit breaker including the same. In addition, the present disclosure is directed to providing a circuit breaking unit having a structure that does not require excessive design changes in order to have a magnet that forms a magnetic field associated with an arc movement path, and an air circuit breaker including the same. In addition, the present disclosure is directed to providing a circuit breaking unit having a structure in which even when a magnet forming a magnetic field associated with an arc movement path is provided, a space occupied by the magnetic body is not excessively increased, and an air circuit breaker including the same. In addition, th