JP811H

JP811H - Circuit breaker

Info

Publication number: JP811H
Authority: JP
Publication date: 1995-03-29

Description

【発明の詳細な説明】［考案の技術分野］この発明は、回路遮断器に関するものであり、とりわ
け、電路の遮断時に発生するアークを誘導するためのア
ークランナを備えた回路遮断器に関するものである。［従来の技術］従来、この種の装置として第１図に示すものがあった。
図において接点１ａを備えた可動接触子１の前方に消弧
用グリツド２が設けてあり、固定接触子部３は主体部の
可動接触子部１側から折り返して略Ｕ字状に形成され、
その先端部の表面に固定接点３ａが設けられた導体３ｂ
と、この導体３ｂより幅狭に形成され、電流遮断時に発
生するアークを消弧用グリツド２へ誘導する板状金属で
なるアークランナ４とから構成されている。電路は可動
接触子１が閉じた状態では接点１ａから接点３ａに電流
が流れ、導体３ｂを通して流される。グリツド２とアー
クランナ４は電路が開かれたときに発生するアークを処
理するものである。以上の構成により、電路において短絡事故や、過負荷運
転時に発生する事故電流により、電流検出リレー（図示
せず）が動作し、第２図に示すように機械的に可動接触
子１が開かれる。このとき、接点１ａと接点３ａとの間
にアーク５が発生する。このアーク５はアークランナ４
に電磁力で誘導され、さらに矢印方向へとアークは誘導
されてグリツド２によつてアーク５が分割され、陰極電
圧降下とアークの冷却効果により、アーク抵抗は増大
し、アーク５を消滅させて遮断を完了する。以上の動作に際し、アークランナ４はアーク５にさらさ
れ、第３図に示すようになり、アークランナ４が溶融し
て、第４図に一点鎖線で示した部分４ａが溶失し、アー
クランナとしての機能を失ない、次の遮断に支障を来た
すことになる。また、このときの金属ガスの発生によ
り、消弧空間の状態を悪化し、遮断時間が長くなるな
ど、遮断性能上も好ましくない。さらに、導体３ｂの主
体部表面がアークにさらされ、該表面が高熱で溶融し金
属ガスを発生するので、消弧空間の状態を悪化するもの
である。従来の回路遮断器は以上のように構成されていたので、
アークランナの全周や導体の主体部表面がアークにさら
され、金属ガスが多くなり、遮断性能を悪化するという
欠点があった。また、アークランナ溶断後は、アークラ
ンナがその機能を失うという欠点もあつた。［発明の概要］この発明は、上記のような従来のものの欠点を除去する
ためになされたもので、アークランナの側面と導体の主
体部表面および固定接点の周面をアークから保護するア
ークガードを設けてなる回路遮断器を提供する。［発明の実施例］以下、この発明の一実施例を第５図〜８図について説明
する。第５図はこの発明の固定接触子部を示している。
絶縁体でなるアークガード６は固定接触子部３に装着さ
れるもので、アークランナ４の両側面と接触ないし近接
する１対の互いに平行な保護壁６ａ、固定接点３ａの周
面を保護する箱状部６ｂ、および上記一対の保護壁６ａ
から側方に延びて導体３ｂの主体部表面を保護する一対
の鍔状部６ｃが形成されている。なお、導体３ｂの後端
部にはめねじ３ｃが形成されている。電路は、従来のものと同様に、可動接触子の接点（図示
せず）から接点３ａ、さらに導体３ｂを介し、めねじ３
ｃにより螺着される外部導体（図示せず）へと通電され
る。次に動作について説明する。従来例と同じように事故電
流を検出して可動接触子が開かれると、アークを発生
し、このアークは接点３ａからアークランナ４へと誘導
される。第６図において、アーク５は接点３ａからアークランナ
４に誘導される。このときのアーク５の状態を示すもの
が第７図で、アークガード６の保護壁６ａがアークラン
ナ４の両側面に近接しているので、アーク５はアークラ
ンナ４の側面、下面に対しては制限を受け、アーク５に
さらされるのは一方向のみとなるので、発生する金属ガ
スは少なく、消弧空間の状態は悪化しない。また、遮断
完了後においても第８図に示すようにアークランナ４の
消耗も一つの面だけとなるので、アークランナ４が溶失
することを防ぐことができる。さらに、アークガード６を大きくして箱状部６ｂで接点
３ａの周囲を、鍔状部６ｃで導体３ｂの主体部表面をそ
れぞれ保護することを兼ねたので、金属ガスの発生をさ
らに押え、遮断時の通過電流を限流して消弧空間の状態
を改善し、遮断性能が経済的に改善される。なお、上記実施例では、回路遮断器の場合について説明
したが、断路器や他の開閉装置であつてもよく、上記実
施例と同様の効果を奏する。［発明の効果］以上のように、この発明によれば、アークランナ、固定
接点および導体の主体部表面を、遮断時に発生するアー
クにさらされるのを制限するアークガードを設けたの
で、遮断時の消弧空間の状態が改善され、遮断性能が向
上する。また、アークランナおよび固定接点の溶断・損
失を防ぐことができる。Description: TECHNICAL FIELD OF THE INVENTION The present invention relates to a circuit breaker, and more particularly to a circuit breaker having an arc runner for inducing an arc generated when a power line is cut off. . [Prior Art] Conventionally, an apparatus of this type has been shown in FIG.
In the figure, an arc extinguishing grid 2 is provided in front of a movable contactor 1 having a contact 1a, and a fixed contactor portion 3 is folded back from the movable contactor portion 1 side of a main body portion and formed into a substantially U shape.
A conductor 3b having a fixed contact 3a provided on the surface of its tip.
And an arc runner 4 made of a plate-like metal that is formed narrower than the conductor 3b and guides an arc generated when the current is cut off to the arc extinguishing grid 2. In the electric path, when the movable contact 1 is closed, a current flows from the contact point 1a to the contact point 3a and flows through the conductor 3b. The grid 2 and the arc runner 4 process the arc generated when the electric circuit is opened. With the above configuration, a current detection relay (not shown) operates due to a short circuit accident in the electric circuit or a fault current generated during overload operation, and the movable contact 1 is mechanically opened as shown in FIG. . At this time, an arc 5 is generated between the contact 1a and the contact 3a. This arc 5 is the arc runner 4
Is induced by an electromagnetic force in the direction of the arrow, and the arc is further induced in the direction of the arrow to divide the arc 5 by the grid 2. Due to the cathode voltage drop and the cooling effect of the arc, the arc resistance increases and the arc 5 disappears. Complete the shutoff. During the above operation, the arc runner 4 is exposed to the arc 5 and becomes as shown in FIG. 3, the arc runner 4 melts, and the portion 4a indicated by the alternate long and short dash line in FIG. Will not interfere with the next cutoff. In addition, the generation of the metal gas at this time deteriorates the state of the arc extinguishing space and prolongs the interruption time, which is not preferable in terms of interruption performance. Further, the surface of the main body of the conductor 3b is exposed to the arc, and the surface melts with high heat to generate metal gas, which deteriorates the state of the arc extinguishing space. Since the conventional circuit breaker was configured as described above,
The entire circumference of the arc runner and the surface of the main body of the conductor are exposed to the arc, the amount of metal gas increases, and the breaking performance deteriorates. Further, there is a drawback that the arc runner loses its function after the melting of the arc runner. SUMMARY OF THE INVENTION The present invention has been made in order to eliminate the above-mentioned drawbacks of the conventional ones, and an arc guard for protecting the side surface of the arc runner, the main body surface of the conductor and the peripheral surface of the fixed contact from the arc. Provided is a circuit breaker. [Embodiment of the Invention] An embodiment of the present invention will be described below with reference to FIGS. FIG. 5 shows the fixed contact portion of the present invention.
The arc guard 6 made of an insulator is attached to the fixed contactor portion 3, and a pair of parallel protection walls 6a contacting or adjoining both side surfaces of the arc runner 4 and a box for protecting the peripheral surface of the fixed contact 3a. Portion 6b and the pair of protective walls 6a
A pair of collar-shaped portions 6c are formed to extend laterally from the side and protect the surface of the main body portion of the conductor 3b. A female screw 3c is formed at the rear end of the conductor 3b. The electric path is similar to the conventional one, from the contact (not shown) of the movable contactor to the contact 3a and further to the conductor 3b, and to the female screw 3
An electric current is applied to an outer conductor (not shown) screwed by c. Next, the operation will be described. When the movable contactor is opened by detecting the fault current as in the conventional example, an arc is generated, and this arc is induced from the contact 3a to the arc runner 4. In FIG. 6, the arc 5 is guided to the arc runner 4 from the contact 3a. The state of the arc 5 at this time is shown in FIG. 7, and since the protective wall 6a of the arc guard 6 is close to both side surfaces of the arc runner 4, the arc 5 is restricted to the side surface and the lower surface of the arc runner 4. Accordingly, since the arc 5 is exposed to only one direction, the amount of metal gas generated is small and the state of the arc extinguishing space does not deteriorate. Further, even after the interruption is completed, the arc runner 4 is consumed only on one surface as shown in FIG. 8, so that the arc runner 4 can be prevented from being melted and lost. Further, the arc guard 6 is enlarged to protect the periphery of the contact 3a by the box-shaped portion 6b and protect the surface of the main body portion of the conductor 3b by the collar-shaped portion 6c. Time passing current is limited to improve the condition of the arc extinguishing space, and the breaking performance is economically improved. In addition, in the said Example, although the case of a circuit breaker was demonstrated, it may be a disconnector and another switchgear, and the same effect as the said Example is produced. [Effects of the Invention] As described above, according to the present invention, the arc runner, the fixed contact, and the main body surface of the conductor are provided with the arc guard for limiting the exposure to the arc generated at the time of interruption. The state of the arc-extinguishing space is improved, and the breaking performance is improved. Further, it is possible to prevent melting and loss of the arc runner and the fixed contacts.

【図面の簡単な説明】第１図〜第４図は従来の装置を示し、第１図は要部側断
面図、第２図は動作説明のための要部側断面図、第３図
は動作説明のための第１図III−III線に沿う平面での断
面図、第４図は動作説明のための一部側断面図である。
第５〜８図はこの発明の一実施例を示し、第５図は要部
分解斜視図、第６図は動作説明のための第６図VII−VII
線に沿う平面での断面図、第８図は最終状態を示す第７
図と同一部位の断面図である。１……可動接触子、２……グリツド、３……固定接触子
部、３ａ……固定接点、３ｂ……導体、４……アークラ
ンナ、６……アークガード、６ａ……保護壁、６ｂ……
箱状部、６ｃ……鍔状部。なお、各図中、同一符号は同
一又は相当部分を示す。BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1 to 4 show a conventional device, FIG. 1 is a side sectional view of an essential part, FIG. 2 is a side sectional view of an essential part for explaining the operation, and FIG. FIG. 1 is a sectional view taken along the line III-III of FIG. 1 for explaining the operation, and FIG. 4 is a partial side sectional view for explaining the operation.
5 to 8 show an embodiment of the present invention, FIG. 5 is an exploded perspective view of essential parts, and FIG. 6 is FIG. 6 VII-VII for explaining the operation.
Sectional drawing in the plane along the line, FIG.
It is sectional drawing of the same site as a figure. 1 ... Movable contact, 2 ... Grid, 3 ... Fixed contact, 3a ... Fixed contact, 3b ... Conductor, 4 ... Arc runner, 6 ... Arc guard, 6a ... Protective wall, 6b ... …
Box-shaped part, 6c ... collar-shaped part. In each figure, the same reference numerals indicate the same or corresponding parts.

Claims

[Claims] [Claims] [Claims] [Claim 1] A current detection relay for detecting an accident current, and a movable contact portion mechanically coupled to the current detection relay,
In a circuit breaker provided with a fixed contactor portion facing the movable contactor portion and an arc extinguishing grid disposed in front of the movable contactor portion, the fixed contactor portion includes a main body portion. A conductor that is folded back from the movable contactor side to have a substantially U-shape, and a fixed contact is provided on the surface of the tip of the conductor.
An arc runner, which is formed narrower than this conductor and is made of a plate-shaped metal that guides an arc generated when the current is interrupted to the arc for extinguishing the arc, a side surface of the arc runner made of an insulating material, a main surface of the conductor, and the fixing. An arc guard formed with a pair of mutually parallel protective walls for protecting the peripheral surfaces of the contacts from the arcs, a pair of flange-shaped portions extending laterally from the protective walls, and a box-shaped portion; A circuit breaker characterized by comprising.