201230118 六、發明說明： 【發明所屬之技術領域】 本發明係關於一種用於配線保護等之電路斷路器，尤 其是關於一種具有直動式2接點構造之電路斷路器。 【先前技術】 就習知的電路斷路器而言，例如有記載於專利文獻1 的技術。該技術係爲將U字形的磁性體設置在電流路線不 同的可動接觸子及固定接觸子之外側。根據這樣的構成， 在流通短路電流等大電流時，在接點間可以產生排斥方向 的電磁排斥力（勞倫茲力），可以使可動接觸子朝向離開 固定接觸子的方向動作而提升斷路性能。又可以使在接點 開極後產生在接點間的電弧朝向配置在可動接觸子兩端側 的消弧裝置移動。 (先前技術文獻） (專利文獻） [專利文獻1]日本專利第3 85 9053號公報 【發明內容】 (發明槪要） (發明所欲解決之課題） 然而，利用磁性體產生的電磁力係與電流成比例。因 此，在上述習知的電路斷路器中，在額定電流程度爲比較 小的電流區域中係無法產生大的電磁力。 -5- 201230118 因此，在低電流區域中，將接點開極時產生的電弧朝 向消弧裝置移動的電磁力爲不足的。因此，在電流斷路時 (接點開極動作時）產生在接點間的電弧係必須在兩接點 間之短距離且停滯的狀態予以遮斷，並且爲了在沒有電流 零點的直流電路與高電壓對應，必須有更多的接點開極距 離。其結果爲造成消弧裝置以及製品大型化等的問題。 因此，本發明係以提供一種不會伴隨裝置的大型化， 即使在比較小的電流區域中也可以將接點間的電弧適當地 移動到消弧裝置側之電路斷路器爲課題。 (用以解決課題之手段） 爲了解決上述課題，關於申請專利範圍第1項之電路 斷路器，其在各極具有：配置爲相互對向的前後一對固定 接觸子：橋接前述固定接觸子的直動式可動接觸子；配置 爲各自挾持前述可動接觸子兩端之側面部的前後一對磁氣 驅動軛，該電路斷路器被構成爲藉由接觸彈簧將前述可動 接觸子按壓在前述固定接觸子上，以使各極通電路成爲閉 路，並且藉由開閉機構克服前述接觸彈簧而按壓前述可動 接觸子，使前述可動接觸子離開前述固定接觸子而使前述 通電路成爲開路，其特徵爲：前述磁氣驅動軛係由永久磁 鐵構成。 藉此，當在閉極狀態使電流於可動接觸子流通時，該 電流係與利用磁氣驅動軛予以集束之磁通鎖交，可動接觸 子係承受強的電磁排斥力（勞倫茲力）而朝向離開固定接 ⑧ -6- 201230118 觸子的方向驅動。又在接點開極動作時，雖然在固定接點 與可動接點之間產生電弧，但是該電弧係藉由與利用磁氣 驅動軛加強的磁通鎖交而予以驅動，並且移動到配置在可 動接觸子前後的消弧裝置而被消弧。 在此，因爲使用永久磁鐵作爲磁氣驅動鞭，無論電流 的大小，都可以具有一定的磁通。因此，即使在比較小的 電流區域，也可以將在接點開極動作時產生於接點間的電 弧有效地朝向消弧裝置驅動。 又關於申請專利範圍第2項之電路斷路器，在申請專 利範圍第1項之發明中，前述磁氣驅動軛係由U字形之永久 磁鐵構成，並且配置爲利用兩腳部各自挾持前述可動接觸 子的前述側面部。 如此一來，因爲利用U字形的永久磁鐵構成磁氣驅動 軛，可以利用U字形的兩腳部確實挾持可動接觸子兩端的 側面部，並且因爲可以將磁氣驅動軛配置在期望的位置， 使配置自由度爲大。 再者，關於申請專利範圍第3項之電路斷路器，在申 請專利範圍第1項之發明中’其具備：配置在前述可動接 觸子前後之一對消弧裝置；以跨越此等消弧裝置間的方式 配置在前述可動接觸子的下方’並將在電流斷路時發生在 前述固定接觸子與前述可動接觸子之間的電弧之前述可動 接觸子側的足端予以整流之電弧整流板’前述電弧整流板 係具有朝向前述可動接觸子側彎曲形成的一對U字形磁性 體，前述磁氣驅動軛係由條形的永久磁鐵構成’藉由將其 201230118 下表面固定在前述U字形磁性體的兩腳部上表面，配置爲 各自挾持前述可動接觸子之前述側面部。 如此一來，因爲利用條形的永久磁鐵構成磁氣驅動軛 ，在與利用U字形的永久磁鐵予以構成的情況相比，可以 使永久磁鐵的尺寸變小。因此，可以削減該部份的成本。 再者，因爲與電弧整流板一體構成，可以減少構成零件數 目而實現電路斷路器的組裝性簡單化。 又關於申請專利範圍第4項之電路斷路器，在申請專 利範圍第1項之發明中，其具備：配置在前述可動接觸子 前後之一對消弧裝置；以跨越此等消弧裝置間的方式配置 ，並將在電流斷路時發生於前述固定接觸子與前述可動接 觸子之間的電弧之前述可動接觸子側的足端予以整流之電 弧整流板，前述電弧整流板係具有朝向前述可動接觸子側 彎曲形成的一對U字形磁性體，前述磁氣驅動軛係由條形 的永久磁鐵構成，藉由被固定在前述U字形磁性體的兩腳 部內側表面，配置爲各自挾持前述可動接觸子之前述側面 部。 如此一來，因爲在電弧整流板予以彎曲形成之U字形 磁性體兩腳部的內側表面固定條形的永久磁鐵，與固定在 U字形磁性體兩腳部的前端之情況相比，可以減少來自永 久磁鐵的磁漏。其結果爲可以將在接點開極動作時產生在 接點間的電弧有效地驅動到消弧裝置。 (發明之效果） ⑧ -8 - 201230118 根據本發明，因爲使用永久磁鐵作爲磁氣驅動軛，即 使在比較小的電流區域，也可以將在接點開極時產生在通 電路周圍的電弧確實地朝向消弧裝置側移動。因此，有助 於適合直流電路之小形電路斷路器的提供及製品本體的小 型化，因爲可以使與交流專用品的零件共用化變多，可以 提供低成本的電路斷路器。 【實施方式】 以下，根據圖面說明本發明之實施形態。 (第1實施形態） (構成） 第1圖係爲顯示關於本發明之電路斷路器的電流斷路 部之剖面圖。其中，關於本發明之電路斷路器係爲具有直 動式2接點之電路斷路器。 圖中，符號1爲電流斷路部。在各相通電路中將由平 角導體構成的U字狀固定接觸子2、3於前後對向配置，並 在各個中安裝固定接點2a、3a。兩端呈\字狀彎曲之條形 可動接觸子4係具有能夠各自與固定接點2a、3 a接觸之一 對可動接點4a及4b。該可動接觸子4係在關閉通電路之閉 極狀態中，利用由壓縮彈簧構成的接觸彈簧5朝向固定接 觸子2、3側按壓，藉由可動接點4a及4b各自與固定接點2a 及3a接觸，橋接固定接觸子2、3之間。一方面，在打開通 電路的圖示開極狀態中，可動接觸子4係藉由未圖示的開 201230118 閉機構克服接觸彈簧5而向下按壓，使其離開固定接觸子2 ' 3 ° 又在可動接觸子4的前後係配置一對消弧裝置6，其複 數塊柵極7係包圍可動接觸子4的兩端。柵極7係在上面圖 中由U字狀的磁性板構成，並且支撐在左右一對的絕緣物 之側壁8。再者，在消弧裝置6的下方係以跨越前後的消弧 裝置6之方式，設置由鋼板等高阻抗材構成的電弧整流板9 ，該電弧整流板9也成爲接觸彈簧5的承受板。 圖中符號10爲由U字形的永久磁鐵構成的前後一對磁 氣驅動軛。該磁氣驅動軛10係配置爲利用左右的腳部各自 挾持可動接觸子4兩端的側面部。又左右的腳部之中的一 方腳部爲S極，另一方腳部爲N極，並且配置爲構成第5圖 所示之極性。磁氣驅動軛1 〇的左右腳部係利用絕緣罩1 1予 以覆蓋。 第2圖係爲顯示由電弧整流板9、磁氣驅動軛10及絕緣 罩11構成之磁氣驅動軛部構造之分解立體圖。 絕緣罩1 1係利用樹脂成形，形成爲具有左右一對側壁 1 1 a、1 1 b的U字形，並且在側壁1 1 a、1 1 b之間將可動接觸 子4保持爲可以朝向開閉方向（第1圖的上下方向）移動。 在該絕緣罩1 1的側壁1 1 a、1 1 b中各自形成使下面爲開口的 袋狀部。此等袋狀部係在電路斷路器的組裝時，遮蓋磁氣 驅動軛10的兩腳部l〇a、10b。又電弧整流板9係在電路斷 路器的組裝時，配置在磁氣驅動軛1 〇的兩腳部1 〇a、1 Ob之 間，而且是絕緣罩1 1的下面部外側。 ⑧ -10- 201230118 (動作） 其次’針對第1實施形態，一邊參照第3〜6圖一邊予 以說明。 其中’第3圖係爲顯示接點閉極位置之電流斷路部構 造的剖面圖，第4圖係爲接點附近剖面圖，第5圖係爲接點 附近上面圖，第6圖係爲顯示接點開極位置之電流斷路部 構造及電弧行進方向的圖面。 在第3圖所示之閉極狀態中，如圖中箭頭方向所示， 其係成爲流通像是短路電流的大電流I者。此時，如第4圖 所示，當電流I成爲在與第4圖的紙面垂直方向中從上向下 的方式流經可動接觸子4時，根據該電流I的磁通φ係利用 磁氣驅動軛10予以集束，並且以順時鐘旋轉通過可動接觸 子4及磁氣驅動軛10。此時，由於從第4圖的左朝右通過可 動接觸子4的磁通Φ係與流經可動接觸子4的電流I垂直交 叉，根據弗萊明左手定則，在可動接觸子4中係如第4圖所 示，使電磁排斥力（勞倫茲力）F1朝下方向動作。 同時，未圖示的過電流檢測裝置檢測出過電流並輸出 跳脫訊號，接受該訊號使開閉機構將可動接觸子4朝第3圖 的下方向壓下。藉此，使固定接觸子2及3的固定接點2a及 3a、與可動接觸子4的可動接點4a及4b予以跳脫。 因此，可動接觸子4係利用比單獨的電磁排斥力或是 單獨的開閉機構予以驅動者更大的速度進行開極驅動。因 此，僅是如此就可以提升斷路性能。 -11 - 201230118 又在將固定接點2a及3 a與可動接點4a及4b予以跳脫之 接點開極動作時，在固定接觸子2及3與可動接觸子4之間 產生電弧。該電弧A係如第5圖所示，由於與利用磁氣驅動 軛10加強的磁通（從第4圖的左到右通過的磁通）Φ垂直 交叉，根據弗萊明的左手定則，在電弧A中係使朝向可動 接觸子4的前後方向外側之力F2動作。藉此，在接點間產 生的電弧A係如第6圖所示，以電弧A1—電弧A2—電弧A3 ->電弧A4，朝向配置在可動接觸子4的前後方向外側之消 弧裝置6側移動。被拉進消弧裝置6的電弧A係進行分析· 冷卻並消弧，結束短路斷路動作。 此時，由於設置電弧整流板9，電弧A的可動接觸子4 側之足端係在電弧整流板9上移動，電弧A係在電流沒有流 通可動接觸子4的狀態下予以消弧，可以抑制由於大電流 造成的可動接觸子4之損傷。 然而，習知以來，有使用磁性體作爲磁氣驅動軛者。 第1 3圖係爲顯示習知的電路斷路器之電流斷路部構造 的圖面，（a)爲電流斷路部的上面圖，（b)爲電流斷路 部的正面圖。在此係顯示與電弧整流板109 —體形成由磁 性體構成的磁氣驅動軛1 1 〇之例。換言之，前後一對的磁 氣驅動軛1 10係在電弧整流板1 〇9—體彎曲形成，朝向可動 接觸子104的開極移動方向直立延伸。 根據這樣的構成，當流通短路電流等大電流時，與本 實施形態相同，在接點間產生排斥方向的電磁力，可以使 可動接觸子104朝向離開固定接觸子的方向動作。又接點 -12- 201230118 開極後係可以產生使在接點間產生的電弧朝向消弧裝置移 動的電磁力。 然而，由於利用磁性體產生的電磁力係與電流成比例 ，在使用磁性體作爲磁氣驅動轭的情況，在額定電流左右 之比較小的電流區域中，無法產生大的電磁力，恐怕無法 使在接點開極時產生的電弧適當地朝向消弧裝置移動。因 此，在電流斷路時（接點開極動作時）產生在接點間的電 弧係必須在兩接點間之短距離且停滞的狀態予以遮斷，並 且爲了在沒有電流零點的直流電路與高電壓對應，必須有 更多的接點開極距離。其結果爲造成消弧裝置及製品大型 化的問題。 對於此點，在本實施形態中，因爲使用永久磁鐵作爲 磁氣驅動軛，無論電流的大小都可以產生一定的電磁力。 因此，即使在額定電流左右之比較小的電流區域中也可以 產生充份的電磁力，可以使接點開極時產生的電弧朝向消 弧裝置移動。 如以上所示，可以達成在更寬廣範圍的電流區域有效 使用具有電路斷路器的消弧裝置之電流斷路。 (效果） 如此一來，在第1實施形態中，因爲以各自挾持可動 接觸子兩端的側面之方式配置前後一對的磁氣驅動軛，在 閉極狀態使電流流通可動接觸子時，在固定接觸子與可接 觸子之間產生強大的電磁排斥力（勞倫茲力），使可動接 13- 201230118 觸子朝向離開固定接觸子的方向驅動。又在接點開極動作 時，可以利用勞倫茲力將在接點間產生的電弧朝向消弧裝 置方向驅動。 此時，因爲使用永久磁鐵作爲磁氣驅動軛，無論電流 的大小都可以具有一定的磁通。因此，即使是在比較小的 電流區域中，可以使在接點開極動作時產生在接點間的電 弧有效地朝向消弧裝置方向驅動。 因此，對於在習知構造中對應困難的低電流區域之直 流斷路，可以達成確實使用消弧裝置之寬廣範圍的電流斷 路。因此，有助於適用直流電路之小型消弧裝置的提供及 製品本體的小型化，因爲可以使與交流專用品之零件共用 化變多，可以實現低成本之電路斷路器。 又因爲利用U字形的永久磁鐵構成磁氣驅動軛，根據 U字形的兩腳部可以確實挾持可動接觸子兩端的側面。再 者，因爲將磁氣驅動軛成爲單獨的構件，可以將電弧整流 板形成爲帶狀，在與電弧整流板一體構成的情況相比，使 電弧整流板的成形變得容易，而且可以使磁氣驅動軛的配 置自由度變大。 再者，在接點開極動作過程中，在接點附近中雖然充 滿根據電弧產生之高壓力的導電性氣體，但是藉由利用絕 緣罩完全覆蓋磁氣驅動軛的兩腳部，可以防止磁氣驅動軛 之相間短路的產生。 (第2實施形態） -14- 201230118 其次，針對本發明的第2實施形態予以說明。 該第2實施形態係在前述的第1實施形態中，對於適用 U字形的磁氣驅動軛10而言，其係爲將磁氣驅動軛10與電 弧整流板9一體構成者。 (構成） 第7圖係爲顯示第2實施形態的電流斷路部1構造之剖 面圖。 如該第7圖所示，本實施形態之電流斷路部1係在第1 圖所示之電流斷路部1中，除了磁氣驅動軛部的構成有所 不同，具有與第1圖之電流斷路部1相同的構成。因此，在 具有與第1圖相同的構成之部份附予同一符號，在此以構 成的相異部份爲中心予以說明。 在本實施形態中，使用電弧整流板19取代電弧整流板 9，而且使用條狀的磁氣驅動軛20取代磁氣驅動軛1 〇。 第8圖係爲顯示第2實施形態的磁氣驅動軛部構造之分 解立體圖。 如該第8圖所示，在電弧整流板19的前後方向之可動 接觸子4的兩端位置，各自形成朝向可動接觸子4側彎曲成 形之U字形磁性體19a、19b。 又磁氣驅動軛20係由條形的永久磁鐵構成，藉由使其 下表面固定在電弧整流板19的U字形磁性體19a、19b兩腳 部的上表面，與電弧整流板19一體構成。此時，磁氣驅動 軛20係在可動接觸子4的寬幅方向（左右方向）中，如形 -15- 201230118 成第9圖所示的極性，以相異磁極對向的方式予以配置。 在電路斷路器的組裝時，在形成於電弧整流板19之U 字形磁性體19a、19b的兩腳部上表面固定磁氣驅動軛20之 狀態下，使具有與前述第1實施形態相同構成之絕緣罩1 1 遮蓋U字形磁性體19a、19b及磁氣驅動軛20。 藉此，利用各自固定在U字形磁性體19a、19b的兩腳 部之磁氣驅動軛20挾持可動接觸子4的側面部。換言之，U 字形磁性體19a、19b的兩腳部係以磁氣驅動軛20配置在可 動接觸子4的可動範圍之程度形成爲短。 (動作） 其次，針對第2實施形態的動作予以說明。 在閉極狀態中，當流通像是短路電流的大電流，使固 定接觸子2及3的固定接點2a及3a、與可動接觸子4的可動 接點4a及4b跳脫時，在固定接觸子2及3與可動接觸子4之 間產生電弧。 該電弧A係如第9圖所示，由於與利用磁氣驅動軛20加 強的磁通Φ鎖交，在電弧A中係使朝向可動接觸子4的前後 方向外側之力F2動作。藉此，該電弧A係移動到配置在可 動接觸子4的兩端側之消弧裝置6。 如此一來，與上述的第1實施形態相同，可以將在接 點開極時產生在通電路周圍的電弧適當地朝向消弧裝置側 移動。 ⑧ -16- 201230118 (效果） 如此一來，在第2實施形態中，因爲將磁氣驅動軛與 電弧整流板一體構成’可以使電路斷路器的組裝或零件管 理變得容易。 又因爲磁氣驅動軛成爲條形，與上述第1實施形態中 之u字形的磁氣驅動軛相比，可以使永久磁鐵的尺寸變小 ，可以削減該部份的成本。 (第3實施形態） 其次，針對本發明的第3實施形態予以說明。 該第3實施形態係在前述第2實施形態中，對於將磁氣 驅動軛固定在形成於電弧整流板的U字形磁性體兩腳部的 上表面而言，其係爲固定在U字形磁性體兩腳部的內側表 面者。 (構成） 本實施形態之電流斷路部1係在第8圖所示之電流斷路 部1中，除了磁氣驅動軛部的構成有所不同，具有與第8圖 的電流斷路部1相同的構成。因此，在此以構成的相異部 份爲中心予以說明。 第1 0圖係爲顯示第3實施形態之磁氣驅動軛部構造的 分解立體圖。 如該第1〇圖所示，在電弧整流板29的前後方向之可動 接觸子4的兩端位置，各自形成朝向可動接觸子4側彎曲成 -17- 201230118 形之U字形磁性體29a、29b。又在此等U字形磁性體29a、 2 9b的兩腳部內側係形成用以固定磁氣驅動軛3 0之段差部 2 9 c ° 磁氣驅動軛30係由具有與段差部29c相同厚度之條形 的永久磁鐵構成，並且藉由固定在形成於電弧整流板29的 段差部29c，與電弧整流板29 —體構成。換言之，磁氣驅 動軛30係固定在U字形磁性體29a、29b兩腳部的內側表面 。此時，磁氣驅動軛30係在可動接觸子4的寬幅方向（左 右方向）中，如形成第1 1圖所示的極性，使相異磁極對向 的方式予以配置。 在電路斷路器的組裝時，在形成於電弧整流板29之段 差部29c固定磁氣驅動軛30之狀態下，使具有與前述第1及 第2實施形態相同構成之絕緣罩1 1遮蓋U字形磁性體29a、 29b及磁氣驅動軛30。 藉此，利用各自固定在U字形磁性體29a、2 9b的兩腳 部的磁氣驅動軛30挾持可動接觸子4的側面部。換言之，U 字形磁性體29a、29b的兩腳部係以磁氣驅動軛30配置在可 動接觸子4的可動範圍之程度形成爲長。 (動作） 其次，針對第3實施形態的動作予以說明。 在閉極狀態中，當流通像是短路電流的大電流I，使 固定接觸子2及3的固定接點2a及3a、與可動接觸子4的可 動接點4a及4b跳脫時’在固定接觸子2及3與可動接觸子4 -18- 201230118 之間產生電弧。 該電弧A係如第1 1圖所示，由於與利用磁氣驅動軛3 0 加強的磁通Φ鎖交，在電弧A中係使朝向可動接觸子4的前 後方向外側之力F2動作。藉此，該電弧A係移動到配置在 可動接觸子4的兩端側之消弧裝置6。 如此一來，與上述的第1及第2實施形態相同，可以將 在接點開極時產生在通電路周圍的電弧適當地朝向消弧裝 置側移動。 然而，如第2實施形態所示，在將磁氣驅動軛30固定 在形成於電弧整流板19的U字形磁性體19a、19b的兩腳部 上表面之情況下，如第1 2圖所示，會產生來自永久磁鐵的 洩漏磁通Φ ’。爲此，無法有效產生用以將在接點間產生 的電弧A朝向消弧裝置6側驅動的電磁力。 相對於此在本實施形態中，將由永久磁鐵構成的磁氣 驅動軛30固定在U字形磁體體29a、29b兩腳部的內側表面 。換言之，在由永久磁鐵構成的磁氣驅動軛3 0的外側配置 U字形磁體體29a、29b。爲此，如第I2圖所示，可以減少 永久磁鐵之洩漏磁通Φ ’，可以有效產生用以將在接點間 產生的電弧A朝向消弧裝置6側驅動的電磁力。 (效果） 如此一來，在第3實施形態中，因爲將磁氣驅動軛與 電弧整流板一體構成，可以使電路斷路器的組裝或零件管 理變得容易。 -19- 201230118 又因爲磁氣驅動軛成爲條形，與上述第1實施形態中 之u字形的磁氣驅動軛相比，可以使永久磁鐵的尺寸變小 ，可以削減該部份的成本。 再者，因爲將磁氣驅動軛固定在電弧整流板的U字形 磁體兩腳部的內側表面，可以減少來自永久磁鐵的磁漏， 可以有效地將在接點間產生的電弧朝向消弧裝置側移動。 又因爲將磁氣驅動軛固定在形成於電弧整流板的U字 形磁性體的段差部，與上述第2實施形態的磁氣驅動軛相 比，可以使永久磁鐵的厚度變薄，可以削減該部份的成本 。再者，因爲可以將磁氣驅動軛吸附在段差部，在與沒有 段差單純將磁氣驅動軛固定在U字形磁性體兩腳部的內側 表面的情況相比，使磁氣驅動軛的定位變得容易，可以使 組裝性簡單化。 【圖式簡單說明】 第1圖係爲顯示關於本發明之電路斷路器的電流斷路 部構造之剖面圖。 第2圖係爲顯示第1實施形態的磁氣驅動軛部構造之分 解立體圖。 第3圖係爲顯示接點閉極位置中的電流斷路部構造之 剖面圖。 第4圖係爲第1實施形態的接點附近剖面圖及電流、磁 通、電磁排斥力的向量圖。 第5圖係爲第1實施形態的接點附近上面圖及電流、磁 ⑧ -20- 201230118 通、電磁排斥力的向量圖。 第6圖係爲顯示第1實施形態的接點開極位置中的電流 斷路部構造與電弧行進方向的圖面。 第7圖係爲顯示第2實施形態的電流斷路部構造之剖面 圖。 第8圖係爲顯示第2實施形態的磁氣驅動軛部構造之分 解立體圖。 第9圖係爲第2實施形態的接點附近上面圖及電流、磁 通、電磁排斥力的向量圖。 第10圖係爲顯示第3實施形態的磁氣驅動軛部構造之 分解立體圖。 第1 1圖係爲第3實施形態的接點附近上面圖及電流、 磁通、電磁排斥力的向量圖。 第I2圖係爲顯不來自磁氣驅動輔的磁漏之圖面。 第1 3圖係爲顯示習知的電流斷路器之電流斷路部構造 之圖面。 【主要元件符號說明】 1 :電流斷路器 2 :固定接觸子 3 :固定接觸子 2a、3a:固定接點 4 :可動接觸子 4a、4b :可動接點 -21 - 201230118 5 :接觸彈簧 6 :消弧裝置 7 :柵極 8 :側壁 9 :電弧整流板 1 〇 :磁氣驅動軛 10a、10b :腳部 1 1 :絕緣罩 11a、 lib：側壁 1 9 :電弧整流板 19a、19b : U字形磁性體 2 0 :磁氣驅動軛 29 :電弧整流板 29a、29b : U字形磁性體 2 9 c :段差部 3 0 :磁氣驅動軛 ⑧ -22-201230118 SUMMARY OF THE INVENTION [Technical Field] The present invention relates to a circuit breaker for wiring protection and the like, and more particularly to a circuit breaker having a direct-acting 2-contact configuration. [Prior Art] As a conventional circuit breaker, for example, there is a technique described in Patent Document 1. This technique is to provide a U-shaped magnetic body on the outer side of the movable contact and the fixed contact which have different current paths. According to such a configuration, when a large current such as a short-circuit current flows, an electromagnetic repulsion force (Laurz force) in the repulsive direction can be generated between the contacts, and the movable contact can be moved in a direction away from the fixed contact to improve the breaking performance. . Further, the arc generated between the contacts after the contact is opened can be moved toward the arc extinguishing device disposed on both end sides of the movable contact. (Prior Art Document) (Patent Document 1) Japanese Patent No. 3 85 9053 (Summary of the Invention) (Problems to be Solved by the Invention) However, the electromagnetic force generated by the magnetic body is The current is proportional. Therefore, in the above-described conventional circuit breaker, a large electromagnetic force cannot be generated in a current region where the rated current is relatively small. -5- 201230118 Therefore, in the low current region, the electromagnetic force that moves the arc generated when the contact is opened toward the arc extinguishing device is insufficient. Therefore, when the current is broken (when the contact is open), the arc system generated between the contacts must be interrupted in a short distance between the two contacts and in a stagnant state, and in order to have a DC circuit with no current zero. Corresponding voltages must have more contact opening distances. As a result, problems such as an arc extinguishing device and an increase in size of the product are caused. Accordingly, the present invention has been made in an effort to provide a circuit breaker that appropriately moves an arc between contacts to the arc extinguishing device side even in a relatively small current region without increasing the size of the device. (Means for Solving the Problem) In order to solve the above problems, the circuit breaker according to the first aspect of the invention is characterized in that each of the poles has a pair of fixed contact pairs arranged to face each other: bridging the fixed contact a direct-acting movable contact; a pair of front and rear magnetic driving yokes each configured to hold a side portion of the movable contact, the circuit breaker being configured to press the movable contact to the fixed contact by a contact spring In order to make the pole-connected circuits closed, the movable contact is pressed against the contact spring by the opening and closing mechanism, and the movable contact is separated from the fixed contact to open the through-circuit, and is characterized in that: The magnetic gas driving yoke is composed of a permanent magnet. Thereby, when the current is caused to flow through the movable contact in the closed state, the current is locked with the magnetic flux bundled by the magnetic driving yoke, and the movable contact subsystem is subjected to strong electromagnetic repulsive force (Laurz force). It is driven in the direction away from the fixed contact 8 -6 - 201230118. In addition, when the contact opening action is performed, although an arc is generated between the fixed contact and the movable contact, the arc is driven by the magnetic flux lock which is reinforced by the magnetic drive yoke, and is moved to be disposed at The arc extinguishing device before and after the movable contact is arc extinguished. Here, since the permanent magnet is used as the magnetic driving whip, it is possible to have a certain magnetic flux regardless of the magnitude of the current. Therefore, even in a relatively small current region, the arc generated between the contacts when the contact is opened can be efficiently driven toward the arc extinguishing device. Further, in the circuit breaker of claim 2, in the invention of claim 1, the magnetic air drive yoke is formed of a U-shaped permanent magnet, and is configured to hold the movable contact by each of the two leg portions. The aforementioned side portion of the child. In this way, since the magnetic driving yoke is constituted by the U-shaped permanent magnet, the side portions of the both ends of the movable contact can be surely held by the U-shaped legs, and since the magnetic driving yoke can be disposed at a desired position, The degree of freedom of configuration is large. Furthermore, the circuit breaker of claim 3, in the invention of claim 1 of the invention, is characterized in that: it is provided with one of a pair of arc extinguishing devices disposed before and after the movable contact; An arc-rectifier plate in which the foot end of the movable contact side of the arc between the fixed contact and the movable contact is rectified at the lower side of the movable contact and the arc contact between the fixed contact and the movable contact is reversed. The arc rectifying plate has a pair of U-shaped magnetic bodies which are formed to be curved toward the movable contact side, and the magnetic driving yoke is formed of a strip-shaped permanent magnet 'by fixing the lower surface of the 201230118 to the U-shaped magnetic body The upper surfaces of the two leg portions are disposed to each hold the aforementioned side portions of the movable contact. In this manner, since the magnetic driving yoke is constituted by the strip-shaped permanent magnets, the size of the permanent magnet can be made smaller than in the case of the U-shaped permanent magnet. Therefore, the cost of this part can be reduced. Further, since it is integrally formed with the arc rectifying plate, the number of components can be reduced, and the assembly of the circuit breaker can be simplified. Further, in the circuit breaker of claim 4, in the invention of claim 1, the invention provides: an arc extinguishing device disposed before and after the movable contact; and spanning between the arc extinguishing devices And an arc rectifying plate that rectifies the foot end of the movable contact side of the arc between the fixed contact and the movable contact when the current is interrupted, and the arc rectifying plate has a movable contact toward the foregoing a pair of U-shaped magnetic bodies formed by bending the sub-side, wherein the magnetic gas driving yoke is formed of a strip-shaped permanent magnet, and is fixed to the inner surface of both leg portions of the U-shaped magnetic body, and is disposed to each hold the movable contact The aforementioned side portion of the child. In this way, since the strip-shaped permanent magnets are fixed to the inner side surfaces of the leg portions of the U-shaped magnetic body formed by bending the arc rectifying plate, the number of the permanent magnets can be reduced as compared with the case where the front ends of the U-shaped magnetic bodies are fixed. Magnetic leakage of permanent magnets. As a result, the arc generated between the contacts when the contact is opened can be efficiently driven to the arc extinguishing device. (Effects of the Invention) 8 -8 - 201230118 According to the present invention, since a permanent magnet is used as the magnetic gas driving yoke, even in a relatively small current region, an arc generated around the through circuit when the contact is opened can be surely Move toward the side of the arc extinguishing device. Therefore, it contributes to the provision of the small-sized circuit breaker suitable for the DC circuit and the miniaturization of the product body, since the parts for the AC-specific products can be shared, and a low-cost circuit breaker can be provided. [Embodiment] Hereinafter, embodiments of the present invention will be described based on the drawings. (First Embodiment) (Configuration) Fig. 1 is a cross-sectional view showing a current interruption portion of a circuit breaker according to the present invention. Among them, the circuit breaker of the present invention is a circuit breaker having a direct-acting 2-contact. In the figure, the symbol 1 is a current interruption portion. In each of the communication circuits, U-shaped fixed contacts 2, 3 made of a rectangular conductor are arranged in the front-rear direction, and fixed contacts 2a, 3a are attached to each of them. The strips are bent in a chevron shape at both ends. The movable contact 4 has a pair of movable contacts 4a and 4b which are each capable of contacting the fixed contacts 2a, 3a. The movable contact 4 is pressed toward the fixed contacts 2 and 3 by a contact spring 5 composed of a compression spring in a closed state of the closed circuit, and each of the movable contacts 4a and 4b and the fixed contact 2a Contact 3a, bridge between fixed contacts 2, 3. On the other hand, in the illustrated open state of the open circuit, the movable contact 4 is pressed downward by the opening mechanism 201230118, which is not shown, against the contact spring 5, and is moved away from the fixed contact 2' 3 °. A pair of arc extinguishing means 6 are disposed in front of and behind the movable contact 4, and a plurality of block gates 7 surround both ends of the movable contact 4. The gate electrode 7 is composed of a U-shaped magnetic plate in the above figure, and is supported by the side walls 8 of a pair of left and right insulators. Further, an arc rectifying plate 9 made of a high-resistance material such as a steel plate is provided below the arc extinguishing device 6 so as to extend over the arc extinguishing device 6 before and after the arc extinguishing device 6, and the arc rectifying plate 9 also serves as a receiving plate for the contact spring 5. Reference numeral 10 in the figure is a pair of front and rear magnetic driving yokes composed of U-shaped permanent magnets. The magnetic air drive yoke 10 is disposed such that the side portions of both ends of the movable contact 4 are held by the left and right leg portions. Further, one of the left and right leg portions is an S pole, and the other leg portion is an N pole, and is arranged to constitute the polarity shown in Fig. 5. The left and right leg portions of the magnetic air drive yoke 1 are covered with an insulating cover 1 1 . Fig. 2 is an exploded perspective view showing the structure of the magnetic air drive yoke portion including the arc rectifying plate 9, the magnetic gas driving yoke 10, and the insulating cover 11. The insulating cover 11 is formed of a resin and formed into a U-shape having a pair of right and left side walls 1 1 a, 1 1 b, and the movable contact 4 is held between the side walls 1 1 a and 1 1 b so as to be openable and closable. (Up and down direction of Fig. 1) moves. A pocket portion having an opening in the lower surface is formed in each of the side walls 1 1 a and 1 1 b of the insulating cover 1 1 . These pockets cover the legs 10a, 10b of the magnetic drive yoke 10 when the circuit breaker is assembled. Further, the arc rectifying plate 9 is disposed between the leg portions 1a and 1b of the magnetic air driving yoke 1 and is disposed outside the lower surface of the insulating cover 1 when the circuit breaker is assembled. 8 -10- 201230118 (Operation) Next, the first embodiment will be described with reference to the third to sixth embodiments. The 'figure 3 is a cross-sectional view showing the structure of the current breaking portion at the closed position of the joint, the fourth is a cross-sectional view near the joint, the fifth is the top view near the joint, and the sixth is the display. The current breaking portion structure of the contact opening position and the drawing of the arc traveling direction. In the closed-pole state shown in Fig. 3, as shown by the direction of the arrow in the figure, it is a large current I whose circulating image is a short-circuit current. At this time, as shown in FIG. 4, when the current I flows through the movable contact 4 from the top to the bottom in the direction perpendicular to the plane of the paper of FIG. 4, the magnetic flux φ according to the current I utilizes the magnetic gas. The drive yoke 10 is bundled and rotated clockwise through the movable contact 4 and the magnetic air drive yoke 10. At this time, since the magnetic flux Φ passing through the movable contact 4 from the left to the right of FIG. 4 vertically intersects the current I flowing through the movable contact 4, according to Fleming's left-hand rule, in the movable contact 4 As shown in Fig. 4, the electromagnetic repulsive force (Laurz force) F1 is moved downward. At the same time, an overcurrent detecting device (not shown) detects an overcurrent and outputs a trip signal, and receives the signal to cause the opening and closing mechanism to push the movable contact 4 downward in the downward direction of Fig. 3. Thereby, the fixed contacts 2a and 3a of the fixed contacts 2 and 3 and the movable contacts 4a and 4b of the movable contact 4 are tripped. Therefore, the movable contact 4 is driven to be opened at a higher speed than the individual electromagnetic repulsion force or a separate opening and closing mechanism. Therefore, only this can improve the breaking performance. -11 - 201230118 When an open contact is made between the fixed contacts 2a and 3a and the movable contacts 4a and 4b, an arc is generated between the fixed contacts 2 and 3 and the movable contact 4. As shown in Fig. 5, the arc A is perpendicularly intersected with the magnetic flux reinforced by the magnetic driving yoke 10 (the magnetic flux passing from the left to the right of Fig. 4) Φ, according to Fleming's left-hand rule, In the arc A, the force F2 toward the outer side in the front-rear direction of the movable contact 4 is operated. Thereby, as shown in Fig. 6, the arc A generated between the contacts is directed toward the arc extinguishing device 6 disposed outside the front-rear direction of the movable contact 4 by the arc A1 - arc A2 - arc A3 - > arc A4 Side movement. The arc A that has been pulled into the arc extinguishing device 6 analyzes, cools, and extinguishes the arc, and ends the short circuit breaking operation. At this time, since the arc rectifying plate 9 is provided, the foot end of the movable contact 4 side of the arc A moves on the arc rectifying plate 9, and the arc A is extinguished in a state where the current does not flow through the movable contact 4, and can be suppressed. Damage to the movable contact 4 due to large current. However, conventionally, a magnetic body has been used as a magnetic gas drive yoke. Fig. 1 is a view showing a structure of a current interruption portion of a conventional circuit breaker, wherein (a) is a top view of the current interruption portion, and (b) is a front view of the current interruption portion. Here, an example in which the magnetic arc drive yoke 1 1 由 composed of a magnetic body is formed integrally with the arc rectifying plate 109 is shown. In other words, the pair of front and rear magnetic drive yokes 1 10 are formed by bending the arc rectifying plate 1 〇 9 body, and extend upright in the direction of the opening movement of the movable contact 104. According to this configuration, when a large current such as a short-circuit current flows, as in the present embodiment, an electromagnetic force in the repulsive direction is generated between the contacts, and the movable contact 104 can be moved in a direction away from the fixed contact. Contact -12- 201230118 Open post can generate electromagnetic force that causes the arc generated between the contacts to move toward the arc extinguishing device. However, since the electromagnetic force generated by the magnetic body is proportional to the current, when a magnetic body is used as the magnetic gas driving yoke, a large electromagnetic force cannot be generated in a relatively small current region around the rated current, and it is impossible to make it impossible. The arc generated when the contacts are open is properly moved toward the arc extinguishing device. Therefore, when the current is broken (when the contact is open), the arc system generated between the contacts must be interrupted in a short distance between the two contacts and in a stagnant state, and in order to have a DC circuit with no current zero. Corresponding voltages must have more contact opening distances. As a result, there is a problem that the arc extinguishing device and the product are enlarged. In this regard, in the present embodiment, since the permanent magnet is used as the magnetic gas driving yoke, a certain electromagnetic force can be generated regardless of the magnitude of the current. Therefore, even in a relatively small current region where the rated current is relatively small, a sufficient electromagnetic force can be generated, and the arc generated when the contact is opened can be moved toward the arc extinguishing device. As shown above, it is possible to achieve a current interruption in the effective use of an arc extinguishing device having a circuit breaker in a wider range of current regions. (Effects) In the first embodiment, the magnetic flux driving yokes are arranged in a pair of front and rear directions so that the side faces of the movable contactors are held, and when the current is passed through the movable contact in the closed state, the fixing is fixed. A strong electromagnetic repulsive force (Laurent force) is generated between the contact and the contactor, so that the movable contact 13-201230118 is driven away from the fixed contact. At the contact opening action, the Lawrence force can be used to drive the arc generated between the contacts toward the arc-extinguishing device. At this time, since the permanent magnet is used as the magnetic gas driving yoke, it is possible to have a certain magnetic flux regardless of the magnitude of the current. Therefore, even in a relatively small current region, it is possible to cause the arc between the contacts to be efficiently driven toward the arc extinguishing device when the contact is opened. Therefore, for a DC disconnection in a low current region which is difficult in the conventional configuration, a wide range of current interruptions in which the arc extinguishing device is used can be achieved. Therefore, it contributes to the provision of a small arc-extinguishing device to which a DC circuit is applied and the miniaturization of the product body, since the parts for the AC-specific products can be shared, and a low-cost circuit breaker can be realized. Further, since the magnetic driving yoke is constituted by a U-shaped permanent magnet, the side faces of both ends of the movable contact can be surely held by the U-shaped legs. Further, since the magnetic air driving yoke is a separate member, the arc rectifying plate can be formed into a belt shape, and the arc rectifying plate can be easily formed and magnetically made as compared with the case where the arc rectifying plate is integrally formed. The degree of freedom in the arrangement of the air drive yoke becomes large. Further, during the contact opening operation, although the conductive gas according to the high pressure generated by the arc is filled in the vicinity of the contact, the magnetic cover can be prevented by completely covering the both legs of the magnetic driving yoke with the insulating cover. The generation of a phase-to-phase short circuit of the gas-driven yoke. (Second embodiment) -14 - 201230118 Next, a second embodiment of the present invention will be described. In the first embodiment, the magnetic drive yoke 10 to which the U-shape is applied is formed by integrally forming the magnetic drive yoke 10 and the arc rectifying plate 9. (Configuration) Fig. 7 is a cross-sectional view showing the structure of the current interrupting unit 1 of the second embodiment. As shown in Fig. 7, the current interrupting unit 1 of the present embodiment is connected to the current interrupting unit 1 shown in Fig. 1, except that the configuration of the magnetic driving yoke portion is different, and the current interrupting circuit of Fig. 1 is provided. Part 1 has the same configuration. Therefore, the same components as those in the first embodiment are denoted by the same reference numerals, and the description will be focused on the different components. In the present embodiment, the arc rectifying plate 19 is used instead of the arc rectifying plate 9, and the magnetic magnetic driving yoke 20 is used instead of the magnetic driving yoke 1 . Fig. 8 is an exploded perspective view showing the structure of the magnetic air drive yoke portion of the second embodiment. As shown in Fig. 8, U-shaped magnetic bodies 19a and 19b which are bent toward the movable contact 4 side are formed at positions of both ends of the movable contact 4 in the front-rear direction of the arc rectifying plate 19. Further, the magnetic air drive yoke 20 is formed of a strip-shaped permanent magnet, and is fixed to the upper surface of both leg portions of the U-shaped magnetic bodies 19a and 19b of the arc rectifying plate 19 by the lower surface thereof, and is integrally formed with the arc rectifying plate 19. At this time, the magnetic driving yoke 20 is disposed in the width direction (left-right direction) of the movable contact 4, and has a polarity as shown in Fig. 9 in the form of -15-201230118, and is disposed such that the different magnetic poles face each other. In the state in which the magnetic circuit drive yoke 20 is fixed to the upper surfaces of the leg portions of the U-shaped magnetic bodies 19a and 19b formed on the arc rectifying plate 19, the magnetic yoke yoke 20 is formed in the same manner as in the first embodiment. The insulating cover 1 1 covers the U-shaped magnetic bodies 19a and 19b and the magnetic air drive yoke 20. Thereby, the side surface portions of the movable contact 4 are held by the magnetic air driving yokes 20 which are fixed to the both leg portions of the U-shaped magnetic bodies 19a and 19b. In other words, the leg portions of the U-shaped magnetic bodies 19a and 19b are formed to be short in such a manner that the magnetic driving yoke 20 is disposed in the movable range of the movable contact 4 . (Operation) Next, the operation of the second embodiment will be described. In the closed state, when a large current such as a short-circuit current flows, the fixed contacts 2a and 3a of the fixed contacts 2 and 3 and the movable contacts 4a and 4b of the movable contact 4 are tripped, in a fixed contact An arc is generated between the children 2 and 3 and the movable contact 4. As shown in Fig. 9, the arc A is interlocked with the magnetic flux Φ which is reinforced by the magnetic driving yoke 20, and the force F2 toward the outer side in the front-rear direction of the movable contact 4 is operated in the arc A. Thereby, the arc A is moved to the arc extinguishing device 6 disposed on both end sides of the movable contact 4. As described above, as in the first embodiment described above, the arc generated around the through circuit when the contact is opened can be appropriately moved toward the arc extinguishing device side. 8 - 16 - 201230118 (Effects) In the second embodiment, the magnet drive yoke and the arc rectifying plate are integrally formed to facilitate the assembly of the circuit breaker or the component management. Further, since the magnetic driving yoke has a strip shape, the size of the permanent magnet can be made smaller than that of the u-shaped magnetic driving yoke in the first embodiment, and the cost of the portion can be reduced. (Third embodiment) Next, a third embodiment of the present invention will be described. According to the third embodiment, in the second embodiment, the magnetic driving yoke is fixed to the upper surface of the U-shaped magnetic body formed on the arc rectifying plate, and is fixed to the U-shaped magnetic body. The inside surface of both feet. (Configuration) The current interruption unit 1 of the present embodiment has the same configuration as the current interruption unit 1 of Fig. 8 except that the configuration of the magnetic drive yoke is different in the current interruption unit 1 shown in Fig. 8 . . Therefore, the description will be centered on the different components. Fig. 10 is an exploded perspective view showing the structure of the magnetic air drive yoke portion of the third embodiment. As shown in the first figure, the U-shaped magnetic bodies 29a and 29b which are bent toward the movable contact 4 side and formed into a -17-201230118 shape are formed at both end positions of the movable contact 4 in the front-rear direction of the arc rectifying plate 29. . Further, inside the leg portions of the U-shaped magnetic bodies 29a and 29b, a step portion for fixing the magnetic gas driving yoke 30 is formed. The magnetic driving yoke 30 has the same thickness as the step portion 29c. The strip-shaped permanent magnet is formed and fixed to the arc rectifying plate 29 by being fixed to the step portion 29c formed in the arc rectifying plate 29. In other words, the magnetic gas driving yoke 30 is fixed to the inner side surfaces of both leg portions of the U-shaped magnetic bodies 29a and 29b. At this time, the magnetic driving yoke 30 is disposed in the wide direction (left-right direction) of the movable contact 4, and the polarities shown in Fig. 1 are formed to dispose the dissimilar magnetic poles. In the state in which the magnetic circuit drive yoke 30 is fixed to the step portion 29c formed in the arc rectifying plate 29, the insulating cover 1 having the same configuration as that of the first and second embodiments is covered with a U-shape. The magnetic bodies 29a and 29b and the magnetic gas drive yoke 30. Thereby, the side surface portions of the movable contact 4 are held by the magnetic air driving yokes 30 which are fixed to the both leg portions of the U-shaped magnetic bodies 29a and 29b. In other words, the leg portions of the U-shaped magnetic bodies 29a and 29b are formed to be long so that the magnetic driving yoke 30 is disposed in the movable range of the movable contact 4 . (Operation) Next, the operation of the third embodiment will be described. In the closed state, when a large current I such as a short-circuit current flows, the fixed contacts 2a and 3a of the fixed contacts 2 and 3 and the movable contacts 4a and 4b of the movable contact 4 are tripped. An arc is generated between the contacts 2 and 3 and the movable contact 4 -18- 201230118. As shown in Fig. 1, the arc A is interlocked with the magnetic flux Φ which is reinforced by the magnetic driving yoke 30, and the force F2 toward the outer side in the front-rear direction of the movable contact 4 is operated in the arc A. Thereby, the arc A is moved to the arc extinguishing device 6 disposed on both end sides of the movable contact 4. As described above, in the same manner as in the first and second embodiments described above, the arc generated around the through circuit when the contact is opened can be appropriately moved toward the arc extinguishing device side. However, as shown in the second embodiment, when the magnetic driving yoke 30 is fixed to the upper surfaces of the both leg portions of the U-shaped magnetic bodies 19a and 19b formed on the arc rectifying plate 19, as shown in FIG. , will produce leakage flux Φ ' from the permanent magnet. For this reason, the electromagnetic force for driving the arc A generated between the contacts toward the arc extinguishing device 6 side cannot be effectively generated. On the other hand, in the present embodiment, the magnetic driving yoke 30 made of a permanent magnet is fixed to the inner side surfaces of the leg portions of the U-shaped magnet bodies 29a and 29b. In other words, the U-shaped magnet bodies 29a and 29b are disposed outside the magnetic gas driving yoke 30 made of a permanent magnet. For this reason, as shown in Fig. 2, the leakage magnetic flux Φ' of the permanent magnet can be reduced, and the electromagnetic force for driving the arc A generated between the contacts toward the arc extinguishing device 6 side can be effectively generated. (Effect) In the third embodiment, since the magnetic air drive yoke is integrally formed with the arc rectifying plate, assembly of the circuit breaker or component management can be facilitated. -19-201230118 Further, since the magnetic driving yoke has a strip shape, the size of the permanent magnet can be made smaller than that of the u-shaped magnetic gas driving yoke in the first embodiment, and the cost of the portion can be reduced. Furthermore, since the magnetic driving yoke is fixed to the inner side surface of the leg portions of the U-shaped magnet of the arc rectifying plate, the magnetic leakage from the permanent magnet can be reduced, and the arc generated between the contacts can be effectively directed toward the arc extinguishing device side. mobile. Further, since the magnetic driving yoke is fixed to the stepped portion of the U-shaped magnetic body formed in the arc rectifying plate, the thickness of the permanent magnet can be made thinner than the magnetic driving yoke of the second embodiment, and the portion can be reduced. The cost of the share. Further, since the magnetic driving yoke can be adsorbed to the step portion, the positioning of the magnetic driving yoke is changed as compared with the case where the magnetic driving yoke is simply fixed to the inner side surface of the leg portions of the U-shaped magnetic body without the step difference. It is easy to simplify assembly. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a cross-sectional view showing the structure of a current interrupting portion of a circuit breaker according to the present invention. Fig. 2 is an exploded perspective view showing the structure of the magnetic air drive yoke portion of the first embodiment. Fig. 3 is a cross-sectional view showing the structure of the current interruption portion in the closed position of the contact. Fig. 4 is a cross-sectional view of the vicinity of the contact and a vector diagram of current, magnetic flux, and electromagnetic repulsive force in the first embodiment. Fig. 5 is a vector diagram showing the top view of the vicinity of the contact and the current, magnetic 8-20-201230118, and electromagnetic repulsive force in the vicinity of the contact point in the first embodiment. Fig. 6 is a view showing the structure of the current interruption portion and the arc traveling direction in the contact opening position of the first embodiment. Fig. 7 is a cross-sectional view showing the structure of the current interrupting portion of the second embodiment. Fig. 8 is an exploded perspective view showing the structure of the magnetic air drive yoke portion of the second embodiment. Fig. 9 is a top view of the vicinity of the contact in the second embodiment and a vector diagram of current, magnetic flux, and electromagnetic repulsive force. Fig. 10 is an exploded perspective view showing the structure of the magnetic air drive yoke portion of the third embodiment. Fig. 1 is a top view of the vicinity of the contact in the third embodiment, and a vector diagram of current, magnetic flux, and electromagnetic repulsive force. Figure I2 is a diagram showing the magnetic leakage from the magnetic gas drive auxiliary. Fig. 1 is a view showing the structure of a current interrupting portion of a conventional current circuit breaker. [Main component symbol description] 1 : Current breaker 2 : Fixed contact 3 : Fixed contact 2a, 3a: Fixed contact 4 : Movable contact 4a, 4b : Movable contact - 21 - 201230118 5 : Contact spring 6 : Arc extinguishing device 7: Gate 8: Side wall 9: Arc rectifying plate 1 〇: Magnetic gas driving yokes 10a, 10b: Foot portion 1 1 : Insulating cover 11a, lib: Side wall 19: Arc rectifying plates 19a, 19b: U-shaped Magnetic body 20: magnetic gas drive yoke 29: arc rectifying plates 29a, 29b: U-shaped magnetic body 2 9 c: step portion 3 0 : magnetic gas drive yoke 8 -22-