JP2004111174A

JP2004111174A - Contact device

Info

Publication number: JP2004111174A
Application number: JP2002271006A
Authority: JP
Inventors: Hisanaga Matsuoka; 松岡　久永; Kiyoshige Oda; 小田　清成; Toshihiro Katsuta; 勝田　敏宏; Yasushi Kojima; 小島　靖; Tsutomu Matsuki; 松木　務
Original assignee: Nippon Soken Inc; Toyota Motor Corp
Current assignee: Toyota Motor Corp; Soken Inc
Priority date: 2002-09-18
Filing date: 2002-09-18
Publication date: 2004-04-08

Abstract

【課題】接点装置の小型化及びコスト削減を実現する。
【解決手段】可動接触片３は当接片４に対して、ばね８ａ，８ｂの中心軸を通る平面の法線方向の軸回りに揺動可能に支持されており、接点間の付着状態時において、第１の当接部１７と可動接触片３の間の距離が第２の当接部１８と可動接触片３の間の距離より短くなっている。これによって、２組の接点間を切り離す際に、接点間を切り離すための推力は、前半は第１の固定接点１４と第１の可動接点１１の間の溶着を引き剥がすための力として主に作用し、後半は第２の固定接点１２と第２の可動接点１３の間の溶着を引き剥がすための力として主に作用するので、接点間の溶着を引き剥がすために必要な接触片駆動装置１５の推力を小さくすることができ、接点装置の小型化及びコスト削減を実現できる。
【選択図】　　　　図２A contact device is reduced in size and cost.
A movable contact piece (3) is swingably supported with respect to an abutment piece (4) around an axis in a direction normal to a plane passing through the central axes of springs (8a, 8b), and when a contact state is established between contacts. In the example, the distance between the first contact portion 17 and the movable contact piece 3 is shorter than the distance between the second contact portion 18 and the movable contact piece 3. Thereby, when separating the two sets of contacts, the thrust for separating the contacts is mainly used as a force for peeling off the welding between the first fixed contact 14 and the first movable contact 11 in the first half. In the latter half, it mainly acts as a force for peeling off the welding between the second fixed contact 12 and the second movable contact 13, so that the contact piece driving device necessary for peeling off the welding between the contacts 15 thrust can be reduced, and downsizing and cost reduction of the contact device can be realized.
[Selection] Fig. 2

Description

【０００１】
【発明の属する技術分野】
本発明は、電気回路において用いられる接点装置に関する。
【０００２】
【従来の技術】
従来の接点装置の一例が実開平４−１１８５２４号公報（特許文献１）に示されている。この従来の接点装置においては、所定間隔をおいて配置された２組の対向接点（固定接点及び可動接点で構成される）間における付着動作及び切り離し動作を、駆動装置が可動接点を駆動することにより行っている。さらに、２組の対向接点間の切り離し状態時において、２組の対向接点間の間隔を異ならせている。これによって、２組の対向接点間を切り離す際に、間隔が大きい方の対向接点が後に切り離されるようにし、切り離し動作時にアークが発生する対向接点の特定を図っている。
【０００３】
【特許文献１】
実開平４−１１８５２４号公報（第４−６頁、図１）
【０００４】
【発明が解決しようとする課題】
接点装置において対向接点間を切り離すためには、対向接点間の溶着力より大きい推力を駆動装置が発生する必要がある。そして、接点装置が用いられる電気回路条件が高電圧大電流になるほど対向接点間の溶着力が増大するので、駆動装置が発生する推力についても大きくする必要がある。上記の従来の接点装置における切り離し動作の際は、間隔が小さい方の対向接点が先に切り離されるが、駆動装置が発生する推力は両方の対向接点に同時に作用している。したがって、この従来の接点装置においては、可動接点を駆動する駆動装置の推力を大きくする必要があるため、接点装置の大型化及びコスト増大を招いてしまうという課題があった。
【０００５】
本発明は上記課題に鑑みてなされたものであり、小型化及びコスト削減を実現できる接点装置を提供することを目的とする。
【０００６】
【課題を解決するための手段】
このような目的を達成するために、第１の本発明に係る接点装置は、第１の可動接点と第２の可動接点とを所定間隔をおいて備える可動接触片と、第１の可動接点と対向する位置に固定された第１の固定接点と、第２の可動接点と対向する位置に固定された第２の固定接点と、前記可動接触片を駆動するための推力を発生する接触片駆動装置と、を有し、前記接触片駆動装置が発生する推力により、第１の固定接点と第１の可動接点の間及び第２の固定接点と第２の可動接点の間における付着動作及び切り離し動作を行う接点装置であって、前記切り離し動作の際に前記可動接触片の第１の可動接点側を第１の固定接点から離れるように押圧する第１の当接部と、前記切り離し動作の際に前記可動接触片の第２の可動接点側を第２の固定接点から離れるように押圧する第２の当接部と、を備え、前記接触片駆動装置と連結された当接片を有し、前記可動接触片は、前記当接片に対して揺動可能に支持され、第１の固定接点と第１の可動接点の間及び第２の固定接点と第２の可動接点の間の付着状態時において、前記第１の当接部と前記可動接触片の間の距離と、前記第２の当接部と前記可動接触片の間の距離が異なることを特徴とする。
【０００７】
第１の本発明においては、切り離し動作の際に可動接触片の第１の可動接点側を第１の固定接点から離れるように押圧する第１の当接部と、切り離し動作の際に可動接触片の第２の可動接点側を第２の固定接点から離れるように押圧する第２の当接部と、を備え、接触片駆動装置と連結された当接片を有している。そして、可動接触片は当接片に対して揺動可能に支持されており、付着状態時において、第１の当接部と可動接触片の間の距離と第２の当接部と可動接触片の間の距離が異なっている。これによって、２組の接点間を切り離す際に、まず２つの当接部のうちの一方のみが可動接触片を押圧することで、この一方の当接部に近い方の接点間のみを切り離す。このとき、接触片駆動装置による接点間を切り離すための推力は、この一方の当接部による可動接触片への押圧力として主に作用するので、主に一方の当接部に近い方の接点間の溶着を引き剥がすための力としてこの推力を作用させることができる。そして、一方の当接部に近い方の接点間が切り離された後は、他方の当接部が可動接触片を押圧することで、この他方の当接部に近い方の接点間を切り離す。このように、２組の接点間を切り離す際に、接点間を切り離すための推力は、前半は一方の接点間の溶着を引き剥がすための力として主に作用し、後半は他方の接点間の溶着を引き剥がすための力として主に作用するので、接点間の溶着を引き剥がすために必要な接触片駆動装置の推力を小さくすることができる。したがって、接触片駆動装置の小型化を実現でき、接点装置の小型化及びコスト削減を実現できる。
【０００８】
第２の本発明に係る接点装置は、第１の本発明に記載の装置であって、第１の固定接点及び第２の可動接点は正極接点であり、第２の固定接点及び第１の可動接点は負極接点であり、前記可動接触片は、前記付着動作の際に第２の固定接点と第２の可動接点の間の距離が第１の固定接点と第１の可動接点の間の距離より短くなるように、前記当接片に対して支持され、第１の固定接点の材料は、他の接点の材料より高融点の材料であることを特徴とする。
【０００９】
この構成によれば、アークの発生により消耗しやすい接点である後に付着する正極接点のみに高融点材料を用いているので、接触抵抗の増大を招かずに接点の消耗を抑制できる。
【００１０】
第３の本発明に係る接点装置は、第１の本発明に記載の装置であって、第１の固定接点及び第２の可動接点は負極接点であり、第２の固定接点及び第１の可動接点は正極接点であり、前記可動接触片は、前記付着動作の際に第２の固定接点と第２の可動接点の間の距離が第１の固定接点と第１の可動接点の間の距離より短くなるように、前記当接片に対して支持され、第１の可動接点の材料は、他の接点の材料より高融点の材料であることを特徴とする。
【００１１】
この構成においても、アークの発生により消耗しやすい接点である後に付着する正極接点のみに高融点材料を用いているので、接触抵抗の増大を招かずに接点の消耗を抑制できる。
【００１２】
【発明の実施の形態】
以下、本発明の実施の形態（以下実施形態という）を、図面に従って説明する。
【００１３】
（１）第１実施形態
図１は、本発明の第１実施形態に係る接点装置の構成の概略を示す図であり、接点間が切り離されている状態を示す。本実施形態の接点装置は、可動接触片３、第１の固定接点１４、第２の固定接点１２、接触片駆動装置１５及び当接片４を備えている。
【００１４】
可動接触片３は、第１の可動接点１１と第２の可動接点１３とを所定間隔をおいて備えている。第１の固定接点１４は、第１の可動接点１１と対向する位置に固定されている。第２の固定接点１２は、第２の可動接点１３と対向する位置に固定されている。
【００１５】
接触片駆動装置１５は、ソレノイド７、プランジャー１６及びばね９を備えており、第１の固定接点１４と第１の可動接点１１の間及び第２の固定接点１２と第２の可動接点１３の間における付着動作及び切り離し動作を行う。
【００１６】
当接片４は、その連結面４ａがプランジャー１６の駆動方向と略垂直になるように、プランジャー１６と連結されている。可動接触片３はばね８ａ，８ｂを介して当接片４に対して支持されていることにより、可動接触片３は当接片４に対して、ばね８ａ，８ｂの中心軸を通る平面の法線方向の軸回りに揺動可能となっている。
【００１７】
当接片４は、第１の当接部１７及び第２の当接部１８を備えている。接点間の切り離し状態においては、第１の当接部１７は、ばね８ａが第１の可動接点１１を第１の固定接点１４に近づけるように付勢する力の反力として、可動接触片３の第１の可動接点側３ａを押圧している。同様に、第２の当接部１８は、ばね８ｂが第２の可動接点１３を第２の固定接点１２に近づけるように付勢する力の反力として、可動接触片３の第２の可動接点側３ｂを押圧している。そして、図１に示すように、第１の当接部１７と第２の当接部１８とで、当接片４のプランジャー１６との連結面４ａからの高さが異なっており、可動接触片３が連結面４ａに対して斜めに傾いている。一方、第１の固定接点１４と第２の固定接点１２とで、連結面４ａからの高さは略等しい。これによって、接点間の切り離し状態において、第１の固定接点１４と第１の可動接点１１の間の距離が第２の固定接点１２と第２の可動接点１３の間の距離より長くなっている。
【００１８】
次に、本実施形態の接点装置の動作について図２を用いて説明する。
【００１９】
付着動作の際は、ソレノイド７に電流を流すことにより、図２（Ａ）における上方向の推力がプランジャー１６及び当接片４に発生する。この推力は、ばね８ａ，８ｂを介して可動接触片３に伝達され、可動接触片３が固定接点１２，１４に近づく方向に駆動される。このとき、第２の固定接点１２と第２の可動接点１３の間の距離の方が第１の固定接点１４と第１の可動接点１１の間の距離より短い状態が維持されて、図２（Ｂ）に示すように、まず第２の固定接点１２と第２の可動接点１３の間が付着される。
【００２０】
次に、第１の固定接点１４と第１の可動接点１１の間も付着されることで、第１の固定接点１４と第２の固定接点１２の間が導通される。その動作の際は、第２の固定接点１２と第２の可動接点１３の間がすでに付着しているため、図２（Ｃ）に示すように、第１の当接部１７が可動接触片３の第１の可動接点側３ａと当接している状態で可動接触片３の傾きが変化し、第２の当接部１８が可動接触片３の第２の可動接点側３ｂから離れる。したがって、接点間の付着状態においては、図２（Ｃ）に示すように、第１の当接部１７と可動接触片３の間の距離と第２の当接部１８と可動接触片３の間の距離が異なっている。
【００２１】
一方、切り離し動作の際は、ソレノイド７に流す電流を停止すると、ばね９の復元力により、図２（Ｃ）における下方向の推力がプランジャー１６及び当接片４に発生する。このとき、第２の当接部１８は可動接触片３の第２の可動接点側３ｂと当接していないため、この推力は、まず第１の当接部１７が可動接触片３の第１の可動接点側３ａを第１の固定接点１４から離れるように押圧する力として主に作用する。第１の固定接点１４と第１の可動接点１１の間の溶着力より大きい推力を発生させることにより、図２（Ｂ）に示すように、まず第１の固定接点１４と第１の可動接点１１の間が切り離される。
【００２２】
第１の固定接点１４と第１の可動接点１１の間のみが切り離されると、図２（Ｂ）に示すように、可動接触片３の傾きが変化して第２の当接部１８が可動接触片３の第２の可動接点側３ｂと当接する。このとき、プランジャー１６及び当接片４に発生している推力は、第２の当接部１８が可動接触片３の第２の可動接点側３ｂを第２の固定接点１２から離れるように押圧する力として主に作用する。第２の固定接点１２と第２の可動接点１３の間の溶着力より大きい推力を発生させることにより、図２（Ａ）に示すように、第２の固定接点１２と第２の可動接点１３の間も切り離される。これによって、第１の固定接点１４と第２の固定接点１２の間が非導通となる。
【００２３】
なお、上記の動作において、第１の当接部１７が可動接触片３の第１の可動接点側３ａを押圧する位置及び第２の当接部１８が可動接触片３の第２の可動接点側３ｂを押圧する位置については、図２に示すように、それぞれ第１の可動接点１１付近及び第２の可動接点１３付近であることが好ましい。
【００２４】
本実施形態においては、切り離し動作の際に可動接触片３の第１の可動接点側３ａを第１の固定接点１４から離れるように押圧する第１の当接部１７と、切り離し動作の際に可動接触片３の第２の可動接点側３ｂを第２の固定接点１２から離れるように押圧する第２の当接部１８と、を備え、接触片駆動装置１５の推力によって駆動される当接片４を有している。そして、可動接触片３は当接片４に対して、ばね８ａ，８ｂの中心軸を通る平面の法線方向の軸回りに揺動可能に支持されており、接点間の付着状態時において、第１の当接部１７と可動接触片３の間の距離が第２の当接部１８と可動接触片３の間の距離より短くなっている。これによって、２組の接点間を切り離す際に、まず第１の当接部１７のみが可動接触片３の第１の可動接点側３ａを押圧することで、第１の固定接点１４と第１の可動接点１１の間のみを切り離す。このとき、接触片駆動装置１５による接点間を切り離すための推力は、第１の当接部１７による可動接触片３の第１の可動接点側３ａへの押圧力として主に作用するので、第１の固定接点１４と第１の可動接点１１の間の溶着を引き剥がすための力としてこの推力を主に作用させることができる。そして、第１の固定接点１４と第１の可動接点１１の間が切り離された後は、第２の当接部１８が可動接触片３の第２の可動接点側３ｂを押圧することで、第２の固定接点１２と第２の可動接点１３の間を切り離す。このように、２組の接点間を切り離す際に、接点間を切り離すための推力は、前半は第１の固定接点１４と第１の可動接点１１の間の溶着を引き剥がすための力として主に作用し、後半は第２の固定接点１２と第２の可動接点１３の間の溶着を引き剥がすための力として主に作用するので、接点間の溶着を引き剥がすために必要な接触片駆動装置１５の推力を小さくすることができる。したがって、接触片駆動装置１５内のばね９の小型化及びソレノイド７の低電流化等を実現でき、接点装置の小型化及びコスト削減を実現できる。
【００２５】
なお、接点間の溶着を引き剥がすために必要な推力を小さくできる構成は図１に示す構成に限るものではなく、例えば、図３，４，６に示す構成においても接点間の溶着を引き剥がすために必要な推力を小さくでき、接点装置の小型化及びコスト削減を実現できる。
【００２６】
図３においては、第１の当接部１７と第２の当接部１８とで、当接片４のプランジャー１６との連結面４ａからの高さは略等しく、可動接触片３の第１の可動接点側３ａに突起１９が設けられている。そして、接点間の切り離し状態において、第１の当接部１７は突起１９と当接していることにより、第１の固定接点１４と第１の可動接点１１の間の距離が第２の固定接点１２と第２の可動接点１３の間の距離より長くなっている。他の構成は図１に示す構成と同様であり、接点間の付着動作及び切り離し動作については図２に示す場合と同様であるため説明を省略する。
【００２７】
図４においては、当接片４は、その上面４ｂがプランジャー１６の駆動方向と略垂直になるように、プランジャー１６に固定されている。可動接触片３は、ばね８ｃを介して当接片４に対して支持されており、図１の構成と同様に、当接片４に対して揺動可能となっている。
【００２８】
接点間の切り離し状態においては、第１の当接部１７及び第２の当接部１８は、ばね８ｃが可動接触片３を固定接点１２，１４に近づけるように付勢する力の反力として、可動接触片３の第１の可動接点側３ａ及び第２の可動接点側３ｂをそれぞれ押圧している。そして、図４に示すように、第１の当接部１７と第２の当接部１８とで、当接片４の上面４ｂからの高さが異なっており、可動接触片３が当接片４の上面４ｂに対して斜めに傾いている。したがって、図４に示す構成の場合でも、接点間の切り離し状態において、第１の固定接点１４と第１の可動接点１１の間の距離が第２の固定接点１２と第２の可動接点１３の間の距離より長くなっている。他の構成は図１に示す構成と同様であるため説明を省略する。
【００２９】
付着動作の際は、第２の固定接点１２と第２の可動接点１３の間の距離の方が第１の固定接点１４と第１の可動接点１１の間の距離より短い状態で、可動接触片３が固定接点１２，１４に近づく方向に駆動される。したがって、図５（Ｂ）に示すように、まず第２の固定接点１２と第２の可動接点１３の間が付着される。その後、第１の固定接点１４と第１の可動接点１１の間も付着されるが、その際は、図５（Ｃ）に示すように、第１の当接部１７が可動接触片３の第１の可動接点側３ａと当接している状態で可動接触片３の傾きが変化し、第２の当接部１８が可動接触片３の第２の可動接点側３ｂから離れる。したがって、接点間の付着状態においては、図５（Ｃ）に示すように、第１の当接部１７と可動接触片３の第１の可動接点側３ａの間の距離と第２の当接部１８と可動接触片３の第２の可動接点側３ｂの間の距離が異なっている。
【００３０】
一方、切り離し動作の際は、プランジャー１６に発生する推力は、まず第１の当接部１７が可動接触片３の第１の可動接点側３ａを第１の固定接点１４から離れるように押圧する力として主に作用するので、図５（Ｂ）に示すように、まず第１の固定接点１４と第１の可動接点１１の間が切り離される。その後は、図５（Ｂ）に示すように、可動接触片３の傾きが変化して第２の当接部１８が可動接触片３の第２の可動接点側３ｂと当接する。このとき、プランジャー１６に発生する推力は、第２の当接部１８が可動接触片３の第２の可動接点側３ｂを第２の固定接点１２から離れるように押圧する力として主に作用するので、図５（Ａ）に示すように、第２の固定接点１２と第２の可動接点１３の間も切り離される。
【００３１】
なお、上記の動作において、第１の当接部１７が可動接触片３の第１の可動接点側３ａを押圧する位置及び第２の当接部１８が可動接触片３の第２の可動接点側３ｂを押圧する位置については、図５に示すように、それぞれ第１の可動接点１１の真下付近及び第２の可動接点１３の真下付近であることが好ましい。
【００３２】
図６においては、当接片４は、その連結面４ｃがプランジャー１６の駆動方向と略垂直になるように、プランジャー１６に固定されている。さらに、プランジャー１６にはリテーナ２０が固定されている。可動接触片３は、ばね８ｃを介してリテーナ２０に対して支持されており、図１の構成と同様に、当接片４に対して揺動可能となっている。
【００３３】
接点間の切り離し状態においては、第１の当接部１７及び第２の当接部１８は、ばね８ｃが可動接触片３を固定接点１２，１４に近づけるように付勢する力の反力として、可動接触片３の第１の可動接点側３ａ及び第２の可動接点側３ｂをそれぞれ押圧している。そして、図６に示すように、第１の当接部１７と第２の当接部１８とで、当接片４の連結面４ｃからの高さが異なっており、可動接触片３が連結面４ｃに対して斜めに傾いている。したがって、図６に示す構成の場合でも、接点間の切り離し状態において、第１の固定接点１４と第１の可動接点１１の間の距離が第２の固定接点１２と第２の可動接点１３の間の距離より長くなっている。他の構成は図１に示す構成と同様であるため説明を省略する。
【００３４】
付着動作の際は、第２の固定接点１２と第２の可動接点１３の間の距離の方が第１の固定接点１４と第１の可動接点１１の間の距離より短い状態で、可動接触片３が固定接点１２，１４に近づく方向に駆動される。したがって、図７（Ｂ）に示すように、まず第２の固定接点１２と第２の可動接点１３の間が付着される。その後、第１の固定接点１４と第１の可動接点１１の間も付着されるが、その際は、図７（Ｃ）に示すように、第１の当接部１７が可動接触片３の第１の可動接点側３ａと当接している状態で可動接触片３の傾きが変化し、第２の当接部１８が可動接触片３の第２の可動接点側３ｂから離れる。したがって、接点間の付着状態においては、図７（Ｃ）に示すように、第１の当接部１７と可動接触片３の第１の可動接点側３ａの間の距離と第２の当接部１８と可動接触片３の第２の可動接点側３ｂの間の距離が異なっている。
【００３５】
一方、切り離し動作の際は、プランジャー１６に発生する推力は、まず第１の当接部１７が可動接触片３の第１の可動接点側３ａを第１の固定接点１４から離れるように押圧する力として主に作用するので、図７（Ｂ）に示すように、まず第１の固定接点１４と第１の可動接点１１の間が切り離される。その後は、図７（Ｂ）に示すように、可動接触片３の傾きが変化して第２の当接部１８が可動接触片３の第２の可動接点側３ｂと当接する。このとき、プランジャー１６に発生する推力は、第２の当接部１８が可動接触片３の第２の可動接点側３ｂを第２の固定接点１２から離れるように押圧する力として主に作用するので、図７（Ａ）に示すように、第２の固定接点１２と第２の可動接点１３の間も切り離される。
【００３６】
なお、上記の動作において、第１の当接部１７が可動接触片３の第１の可動接点側３ａを押圧する位置及び第２の当接部１８が可動接触片３の第２の可動接点側３ｂを押圧する位置については、図７に示すように、それぞれ第１の可動接点１１付近及び第２の可動接点１３付近であることが好ましい。
【００３７】
（２）第２実施形態
図８は、本発明の第２実施形態に係る接点装置の構成の概略を示す図であり、本実施形態の特徴部分を図１に示す構成に適用した場合を示す。本実施形態においては、第１の固定接点１４及び第２の可動接点１３は正極接点であり、第２の固定接点１２及び第１の可動接点１１は負極接点である。そして、第１の固定接点１４の材料は、第２の固定接点１２、第１の可動接点１１及び第２の可動接点１３の材料より高融点の材料である。その一例としては、第１の固定接点１４の材料にタングステンを用い、第２の固定接点１２、第１の可動接点１１及び第２の可動接点１３の材料に銀を用いた場合が挙げられる。他の構成は図１に示す構成と同様であり、接点間の付着動作及び切り離し動作については図２に示す場合と同様であるため説明を省略する。
【００３８】
接点間の付着動作時には接点にアークが発生し、後に付着する接点の方が、接点同士の衝突によるバウンスが発生しやすいため、アークが発生しやすい。さらに、以下に示す理由により、アークにより消耗しやすい接点を正極接点に特定することができる。
【００３９】
図９は、接点装置の投入回数に対する接点消耗量の変化の実験結果を示す図であり、図９（Ａ）は正極固定接点の消耗量を示し、図９（Ｂ）は正極可動接点の消耗量と負極可動接点の消耗量の和を示し、図９（Ｃ）は負極固定接点の消耗量を示す。なお、図９においては、２組の接点間の付着はほぼ同時に行われ、すべての接点の材料は同一である場合の実験結果を示している。
【００４０】
ここで、正極固定接点の消耗量をＭ１、負極可動接点の消耗量をＭ２、正極可動接点の消耗量をＭ３、負極固定接点の消耗量をＭ４とすると、図９（Ａ）及び図９（Ｂ）から、Ｍ１＝Ｍ２＋Ｍ３、がほぼ成立する。また、図９（Ｃ）から、Ｍ４＝０、がほぼ成立する。さらに、２組の接点が同条件であるとみなすと、Ｍ１＋Ｍ２＝Ｍ３＋Ｍ４、が成立する。これらの３つの式から、（Ｍ２＋Ｍ３）＋Ｍ２＝Ｍ３＋０、が成立するので、Ｍ２＝０及びＭ１＝Ｍ３、という結果が得られる。したがって、負極接点はほとんど消耗しないで正極接点のみが消耗するという結果が得られる。
【００４１】
さらに、正極接点のみが主に消耗する理由を図１０を用いて説明する。図１０（Ａ）に示すように負極接点から出た電子が正極接点に衝突すると、図１０（Ｂ）に示すように正極接点の表面が温度上昇して正極接点材料が活性化する。次に、図１０（Ｃ）に示すように接点間が閉成するにつれて金属蒸気圧が高くなり、金属蒸気が噴出する。これによって、正極接点のみが主に消耗することになる。
【００４２】
本実施形態では、以上の結果を基に、アークの発生により消耗しやすい接点である後に付着する正極接点、すなわち第１の固定接点１４のみにタングステン等の高融点材料を用いている。したがって、接触抵抗の増大を招かずに接点の消耗を抑制できる。
【００４３】
上記の説明では、図１に示す接点装置を例にして説明したが、図３，４，６に示す接点装置においても、後に付着する正極接点である第１の固定接点１４のみに他の接点より高融点の材料、例えばタングステン等を用いることで、接触抵抗の増大を招かずに接点の消耗を抑制できる。
【００４４】
さらに、後に付着する正極接点に他の接点より高融点の材料を用いればよく、例えば図１１に示す構成においても、接触抵抗の増大を招かずに接点の消耗を抑制できる。図１１においては、第１の固定接点１４及び第２の可動接点１３は負極接点であり、第２の固定接点１２及び第１の可動接点１１は正極接点である。そして、第１の可動接点１１の材料は、第１の固定接点１４、第２の固定接点１２及び第２の可動接点１３の材料より高融点の材料、例えばタングステン等である。さらに、図３，４，６に示す接点装置においても、同様の構成を適用することができる。
【００４５】
【発明の効果】
以上説明したように、本発明によれば、接点間の溶着を引き剥がすために必要な駆動装置の推力を小さくすることができるので、接点装置の小型化及びコスト削減を実現できる。
【図面の簡単な説明】
【図１】本発明の第１実施形態に係る接点装置の構成の概略を示す図である。
【図２】本発明の第１実施形態に係る接点装置の付着動作及び切り離し動作を説明する図である。
【図３】本発明の第１実施形態に係る接点装置の他の構成の概略を示す図である。
【図４】本発明の第１実施形態に係る接点装置の他の構成の概略を示す図である。
【図５】本発明の第１実施形態に係る他の接点装置の付着動作及び切り離し動作を説明する図である。
【図６】本発明の第１実施形態に係る接点装置の他の構成の概略を示す図である。
【図７】本発明の第１実施形態に係る他の接点装置の付着動作及び切り離し動作を説明する図である。
【図８】本発明の第２実施形態に係る接点装置の構成の概略を示す図である。
【図９】接点装置の投入回数に対する接点消耗量の変化の実験結果を示す図である。
【図１０】正極接点のみが主に消耗する理由を説明する図である。
【図１１】本発明の第２実施形態に係る接点装置の他の構成の概略を示す図である。
【符号の説明】
３　可動接触片、３ａ　第１の可動接点側、３ｂ　第２の可動接点側、４　当接片、７　ソレノイド、８ａ，８ｂ，８ｃ，９　ばね、１１　第１の可動接点、１２　第２の固定接点、１３　第２の可動接点、１４　第１の固定接点、１５　接触片駆動装置、１６　プランジャー、１７　第１の当接部、１８　第２の当接部。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a contact device used in an electric circuit.
[0002]
[Prior art]
An example of a conventional contact device is disclosed in Japanese Utility Model Laid-Open No. 4-118524 (Patent Document 1). In this conventional contact device, a driving device drives a movable contact to perform an attaching operation and a separating operation between two pairs of opposed contacts (consisting of a fixed contact and a movable contact) arranged at a predetermined interval. It is done by. Further, in the disconnected state between the two sets of opposed contacts, the intervals between the two sets of opposed contacts are made different. Thus, when the two sets of opposed contacts are separated from each other, the opposed contact with the larger interval is separated later, and the opposed contact where an arc occurs during the separating operation is specified.
[0003]
[Patent Document 1]
Japanese Utility Model Application Laid-Open No. 4-118524 (page 4-6, FIG. 1)
[0004]
[Problems to be solved by the invention]
In order to separate the opposing contacts in the contact device, it is necessary for the driving device to generate a thrust larger than the welding force between the opposing contacts. Further, the welding force between the opposed contacts increases as the electric circuit condition in which the contact device is used becomes a high voltage and a large current. At the time of the separating operation in the above-described conventional contact device, the opposing contacts having a smaller interval are separated first, but the thrust generated by the driving device acts on both opposing contacts simultaneously. Therefore, in this conventional contact device, it is necessary to increase the thrust of the driving device for driving the movable contact, and thus there is a problem that the contact device is increased in size and cost is increased.
[0005]
The present invention has been made in view of the above problems, and has as its object to provide a contact device capable of realizing size reduction and cost reduction.
[0006]
[Means for Solving the Problems]
In order to achieve such an object, a contact device according to a first aspect of the present invention includes a movable contact piece having a first movable contact and a second movable contact at a predetermined interval, and a first movable contact. A first fixed contact fixed at a position facing the second movable contact, a second fixed contact fixed at a position facing the second movable contact, and a contact piece for generating a thrust for driving the movable contact piece A contact device between the first fixed contact and the first movable contact and between the second fixed contact and the second movable contact by a thrust generated by the contact piece driving device; A contact device for performing a separating operation, wherein a first contact portion that presses a first movable contact side of the movable contact piece away from a first fixed contact during the separating operation; and the separating operation. The second movable contact side of the movable contact piece to a second fixed contact And a second contact portion for pressing the contact piece away from the contact piece drive device. The movable contact piece is swingably movable with respect to the contact piece. Supported between the first fixed contact and the first movable contact and between the first contact portion and the movable contact piece in an attached state between the second fixed contact and the second movable contact. And a distance between the second contact portion and the movable contact piece is different.
[0007]
In the first aspect of the present invention, the first contact portion for pressing the first movable contact side of the movable contact piece away from the first fixed contact at the time of the separating operation, and the movable contact at the time of the separating operation. And a second contact portion for pressing the second movable contact side of the piece away from the second fixed contact, and having a contact piece connected to the contact piece driving device. The movable contact piece is swingably supported with respect to the contact piece, and in the attached state, the distance between the first contact portion and the movable contact piece and the movable contact piece with the second contact portion. The distance between the pieces is different. Thus, when disconnecting between the two sets of contacts, first, only one of the two contact portions presses the movable contact piece, thereby disconnecting only the contact closer to the one contact portion. At this time, since the thrust for separating the contacts by the contact piece driving device mainly acts as a pressing force on the movable contact piece by the one contact portion, the contact near the one contact portion is mainly used. This thrust can be applied as a force for peeling off the welding between them. Then, after the contact point closer to the one contact part is cut off, the other contact part presses the movable contact piece, thereby separating the contact point closer to the other contact part. As described above, when separating the two sets of contacts, the thrust for separating the contacts mainly acts as a force for peeling off the welding between one contact, and the latter half acts between the other contact in the latter half. Since it mainly acts as a force for peeling off the welding, the thrust of the contact piece driving device required for peeling off the welding between the contacts can be reduced. Therefore, the size of the contact piece driving device can be reduced, and the size and cost of the contact device can be reduced.
[0008]
A contact device according to a second invention is the device according to the first invention, wherein the first fixed contact and the second movable contact are positive contacts, and the second fixed contact and the first fixed contact are The movable contact is a negative contact, and the movable contact piece has a distance between the second fixed contact and the second movable contact during the attaching operation, the distance between the first fixed contact and the first movable contact. The first fixed contact is supported by the contact piece so as to be shorter than the distance, and the material of the first fixed contact is a material having a higher melting point than the material of the other contact.
[0009]
According to this configuration, since the high-melting point material is used only for the positive electrode contact that adheres after being the contact that is easily consumed by the generation of the arc, the contact consumption can be suppressed without increasing the contact resistance.
[0010]
The contact device according to a third aspect of the present invention is the contact device according to the first aspect of the present invention, wherein the first fixed contact and the second movable contact are a negative contact, and the second fixed contact and the first fixed contact are a negative contact. The movable contact is a positive contact, and the movable contact piece has a distance between the second fixed contact and the second movable contact during the attaching operation, the distance between the first fixed contact and the first movable contact. The first movable contact is supported by the contact piece so as to be shorter than the distance, and the material of the first movable contact is a material having a higher melting point than the material of the other contact.
[0011]
Also in this configuration, since the high-melting point material is used only for the positive electrode contact that adheres after being a contact that is easily consumed due to the generation of an arc, the contact consumption can be suppressed without increasing the contact resistance.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention (hereinafter, referred to as embodiments) will be described with reference to the drawings.
[0013]
(1) First embodiment
FIG. 1 is a view schematically showing a configuration of a contact device according to a first embodiment of the present invention, and shows a state where contacts are separated. The contact device of the present embodiment includes a movable contact piece 3, a first fixed contact 14, a second fixed contact 12, a contact piece driving device 15, and a contact piece 4.
[0014]
The movable contact piece 3 includes a first movable contact 11 and a second movable contact 13 at a predetermined interval. The first fixed contact 14 is fixed at a position facing the first movable contact 11. The second fixed contact 12 is fixed at a position facing the second movable contact 13.
[0015]
The contact piece driving device 15 includes a solenoid 7, a plunger 16, and a spring 9, between the first fixed contact 14 and the first movable contact 11, and between the second fixed contact 12 and the second movable contact 13. The attachment operation and the separation operation during the period are performed.
[0016]
The contact piece 4 is connected to the plunger 16 such that the connecting surface 4a is substantially perpendicular to the driving direction of the plunger 16. Since the movable contact piece 3 is supported by the contact piece 4 via the springs 8a and 8b, the movable contact piece 3 is positioned on a plane passing through the central axes of the springs 8a and 8b. It can swing around the normal axis.
[0017]
The contact piece 4 includes a first contact portion 17 and a second contact portion 18. In the disconnected state between the contacts, the first contact portion 17 acts as a reaction force of the force of the spring 8 a for urging the first movable contact 11 to approach the first fixed contact 14, and the movable contact piece 3 Of the first movable contact 3a. Similarly, the second contact portion 18 serves as a reaction force of the spring 8 b for urging the second movable contact 13 to move closer to the second fixed contact 12, so that the second movable contact piece 3 can move the second movable contact 13. The contact side 3b is pressed. As shown in FIG. 1, the first contact portion 17 and the second contact portion 18 have different heights of the contact piece 4 from the connection surface 4 a with the plunger 16 and are movable. The contact piece 3 is obliquely inclined with respect to the connection surface 4a. On the other hand, the first fixed contact 14 and the second fixed contact 12 have substantially the same height from the connection surface 4a. Thereby, in the disconnected state between the contacts, the distance between the first fixed contact 14 and the first movable contact 11 is longer than the distance between the second fixed contact 12 and the second movable contact 13. .
[0018]
Next, the operation of the contact device of the present embodiment will be described with reference to FIG.
[0019]
At the time of the adhering operation, an electric current is caused to flow through the solenoid 7 to generate an upward thrust in the plunger 16 and the contact piece 4 in FIG. This thrust is transmitted to the movable contact piece 3 via the springs 8a and 8b, and the movable contact piece 3 is driven in a direction approaching the fixed contacts 12 and 14. At this time, the state where the distance between the second fixed contact 12 and the second movable contact 13 is shorter than the distance between the first fixed contact 14 and the first movable contact 11 is maintained. As shown in (B), first, the space between the second fixed contact 12 and the second movable contact 13 is attached.
[0020]
Next, the first fixed contact 14 and the first movable contact 11 are also attached to each other, so that the first fixed contact 14 and the second fixed contact 12 are electrically connected. At the time of the operation, since the space between the second fixed contact 12 and the second movable contact 13 has already adhered, the first contact portion 17 has the movable contact piece as shown in FIG. In the state where the movable contact piece 3 is in contact with the first movable contact side 3a, the inclination of the movable contact piece 3 changes, and the second contact portion 18 moves away from the second movable contact side 3b of the movable contact piece 3. Therefore, in the state of adhesion between the contacts, as shown in FIG. 2C, the distance between the first contact portion 17 and the movable contact piece 3 and the distance between the second contact portion 18 and the movable contact piece 3 The distance between them is different.
[0021]
On the other hand, when the current flowing through the solenoid 7 is stopped during the separating operation, a downward thrust in FIG. 2C is generated in the plunger 16 and the contact piece 4 due to the restoring force of the spring 9. At this time, since the second contact portion 18 is not in contact with the second movable contact side 3 b of the movable contact piece 3, the thrust is first generated by the first contact portion 17 of the movable contact piece 3. Mainly acts as a force for pressing the movable contact side 3a of the first fixed contact 14 away from the first fixed contact 14. By generating a thrust larger than the welding force between the first fixed contact 14 and the first movable contact 11, first, as shown in FIG. 2B, the first fixed contact 14 and the first movable contact 11 are cut off.
[0022]
When only the portion between the first fixed contact 14 and the first movable contact 11 is cut off, as shown in FIG. 2B, the inclination of the movable contact piece 3 changes and the second contact portion 18 is movable. The contact piece 3 contacts the second movable contact 3b. At this time, the thrust generated in the plunger 16 and the contact piece 4 is such that the second contact portion 18 separates the second movable contact side 3 b of the movable contact piece 3 from the second fixed contact 12. It mainly acts as a pressing force. By generating a thrust larger than the welding force between the second fixed contact 12 and the second movable contact 13, the second fixed contact 12 and the second movable contact 13 are generated as shown in FIG. Is also separated. As a result, the conduction between the first fixed contact 14 and the second fixed contact 12 becomes non-conductive.
[0023]
In the above operation, the position where the first contact part 17 presses the first movable contact side 3a of the movable contact piece 3 and the second contact part 18 is the second movable contact of the movable contact piece 3 As shown in FIG. 2, the position where the side 3 b is pressed is preferably near the first movable contact 11 and near the second movable contact 13, respectively.
[0024]
In the present embodiment, a first contact portion 17 that presses the first movable contact side 3a of the movable contact piece 3 away from the first fixed contact 14 at the time of the separating operation, A second contact portion 18 that presses the second movable contact side 3 b of the movable contact piece 3 away from the second fixed contact 12, the contact being driven by the thrust of the contact piece driving device 15. It has a piece 4. The movable contact piece 3 is swingably supported with respect to the contact piece 4 around an axis in a direction normal to a plane passing through the central axes of the springs 8a and 8b. The distance between the first contact part 17 and the movable contact piece 3 is shorter than the distance between the second contact part 18 and the movable contact piece 3. Thus, when disconnecting the two sets of contacts, first, only the first contact portion 17 presses the first movable contact side 3a of the movable contact piece 3 so that the first fixed contact 14 and the first fixed contact 14 can be separated. Only the movable contact 11 is separated. At this time, the thrust for separating the contacts by the contact piece driving device 15 mainly acts as a pressing force of the first contact portion 17 on the first movable contact side 3a of the movable contact piece 3, This thrust can be mainly applied as a force for peeling off the welding between the first fixed contact 14 and the first movable contact 11. Then, after the first fixed contact 14 and the first movable contact 11 are separated from each other, the second contact portion 18 presses the second movable contact side 3b of the movable contact piece 3 so that Disconnect between the second fixed contact 12 and the second movable contact 13. As described above, when the two sets of contacts are separated from each other, the thrust for separating the contacts is mainly used as a force for peeling off the welding between the first fixed contact 14 and the first movable contact 11 in the first half. In the latter half, it mainly acts as a force for peeling off the welding between the second fixed contact 12 and the second movable contact 13, so that the contact piece driving necessary for peeling off the welding between the contacts is performed. The thrust of the device 15 can be reduced. Therefore, the size of the spring 9 in the contact piece driving device 15 and the current of the solenoid 7 can be reduced, and the size and cost of the contact device can be reduced.
[0025]
The configuration that can reduce the thrust required for peeling off the welding between the contacts is not limited to the configuration shown in FIG. 1. For example, the configuration shown in FIGS. Therefore, the required thrust can be reduced, and the size and cost of the contact device can be reduced.
[0026]
In FIG. 3, the height of the first contact portion 17 and the second contact portion 18 from the connection surface 4 a of the contact piece 4 with the plunger 16 are substantially equal, and the first contact portion 17 and the second contact portion 18 have the same height. A projection 19 is provided on one movable contact 3a. When the first contact portion 17 is in contact with the projection 19 in the separated state between the contacts, the distance between the first fixed contact 14 and the first movable contact 11 is reduced to the second fixed contact. It is longer than the distance between 12 and the second movable contact 13. The other configuration is the same as the configuration shown in FIG. 1, and the attaching operation and the separating operation between the contacts are the same as those shown in FIG.
[0027]
In FIG. 4, the contact piece 4 is fixed to the plunger 16 such that the upper surface 4b is substantially perpendicular to the driving direction of the plunger 16. The movable contact piece 3 is supported by the contact piece 4 via a spring 8c, and is swingable with respect to the contact piece 4 as in the configuration of FIG.
[0028]
In the disconnected state between the contacts, the first contact portion 17 and the second contact portion 18 serve as a reaction force of the force that the spring 8c biases the movable contact piece 3 to approach the fixed contacts 12 and 14. , And presses the first movable contact side 3a and the second movable contact side 3b of the movable contact piece 3 respectively. As shown in FIG. 4, the height of the first contact portion 17 and the second contact portion 18 from the upper surface 4b of the contact piece 4 is different, and the movable contact piece 3 It is obliquely inclined with respect to the upper surface 4b of the piece 4. Therefore, even in the case of the configuration shown in FIG. 4, in the disconnected state between the contacts, the distance between the first fixed contact 14 and the first movable contact 11 is larger than the distance between the second fixed contact 12 and the second movable contact 13. The distance between them is longer. The other configuration is the same as the configuration shown in FIG.
[0029]
At the time of the attaching operation, when the distance between the second fixed contact 12 and the second movable contact 13 is shorter than the distance between the first fixed contact 14 and the first movable contact 11, the movable contact The piece 3 is driven in a direction approaching the fixed contacts 12 and 14. Therefore, as shown in FIG. 5B, first, the space between the second fixed contact 12 and the second movable contact 13 is attached. Thereafter, the first fixed contact 14 and the first movable contact 11 are also adhered to each other. In this case, as shown in FIG. The tilt of the movable contact piece 3 changes in a state where the movable contact piece 3 is in contact with the first movable contact side 3a, and the second contact portion 18 is separated from the second movable contact side 3b of the movable contact piece 3. Therefore, in the state of adhesion between the contacts, as shown in FIG. 5C, the distance between the first contact portion 17 and the first movable contact side 3a of the movable contact piece 3 and the second contact portion The distance between the portion 18 and the second movable contact side 3b of the movable contact piece 3 is different.
[0030]
On the other hand, at the time of the separating operation, the thrust generated in the plunger 16 first presses the first contact portion 17 so that the first movable contact side 3 a of the movable contact piece 3 is separated from the first fixed contact 14. As shown in FIG. 5B, the first fixed contact 14 and the first movable contact 11 are separated from each other. Thereafter, as shown in FIG. 5B, the inclination of the movable contact piece 3 changes, and the second contact portion 18 comes into contact with the second movable contact side 3b of the movable contact piece 3. At this time, the thrust generated in the plunger 16 mainly acts as a force for the second contact portion 18 to push the second movable contact side 3b of the movable contact piece 3 away from the second fixed contact 12. Therefore, as shown in FIG. 5A, the second fixed contact 12 and the second movable contact 13 are also disconnected.
[0031]
In the above operation, the position where the first contact part 17 presses the first movable contact side 3a of the movable contact piece 3 and the second contact part 18 is the second movable contact of the movable contact piece 3 As shown in FIG. 5, it is preferable that the position where the side 3b is pressed is near the position directly below the first movable contact 11 and near the position directly below the second movable contact 13, respectively.
[0032]
In FIG. 6, the contact piece 4 is fixed to the plunger 16 so that the connecting surface 4c is substantially perpendicular to the driving direction of the plunger 16. Further, a retainer 20 is fixed to the plunger 16. The movable contact piece 3 is supported by a retainer 20 via a spring 8c, and can swing with respect to the contact piece 4 as in the configuration of FIG.
[0033]
In the disconnected state between the contacts, the first contact portion 17 and the second contact portion 18 serve as a reaction force of the force that the spring 8c biases the movable contact piece 3 to approach the fixed contacts 12 and 14. , And presses the first movable contact side 3a and the second movable contact side 3b of the movable contact piece 3 respectively. As shown in FIG. 6, the first contact portion 17 and the second contact portion 18 have different heights from the connection surface 4c of the contact piece 4, and the movable contact piece 3 is connected. It is obliquely inclined with respect to the surface 4c. Therefore, even in the configuration shown in FIG. 6, in the disconnected state between the contacts, the distance between the first fixed contact 14 and the first movable contact 11 is larger than the distance between the second fixed contact 12 and the second movable contact 13. The distance between them is longer. The other configuration is the same as the configuration shown in FIG.
[0034]
At the time of the attaching operation, when the distance between the second fixed contact 12 and the second movable contact 13 is shorter than the distance between the first fixed contact 14 and the first movable contact 11, the movable contact The piece 3 is driven in a direction approaching the fixed contacts 12 and 14. Therefore, as shown in FIG. 7B, the space between the second fixed contact 12 and the second movable contact 13 is first adhered. Thereafter, the first fixed contact 14 and the first movable contact 11 are also adhered to each other. In this case, as shown in FIG. The tilt of the movable contact piece 3 changes in a state where the movable contact piece 3 is in contact with the first movable contact side 3a, and the second contact portion 18 is separated from the second movable contact side 3b of the movable contact piece 3. Therefore, in the state of adhesion between the contacts, as shown in FIG. 7C, the distance between the first contact portion 17 and the first movable contact side 3a of the movable contact piece 3 and the second contact The distance between the portion 18 and the second movable contact side 3b of the movable contact piece 3 is different.
[0035]
On the other hand, at the time of the separating operation, the thrust generated in the plunger 16 first presses the first contact portion 17 so as to separate the first movable contact side 3a of the movable contact piece 3 from the first fixed contact 14. 7B, the first fixed contact 14 and the first movable contact 11 are separated from each other, as shown in FIG. 7B. After that, as shown in FIG. 7B, the inclination of the movable contact piece 3 changes, and the second contact portion 18 contacts the second movable contact side 3b of the movable contact piece 3. At this time, the thrust generated in the plunger 16 mainly acts as a force for the second contact portion 18 to push the second movable contact side 3b of the movable contact piece 3 away from the second fixed contact 12. Therefore, as shown in FIG. 7A, the second fixed contact 12 and the second movable contact 13 are also separated.
[0036]
In the above operation, the position where the first contact part 17 presses the first movable contact side 3a of the movable contact piece 3 and the second contact part 18 is the second movable contact of the movable contact piece 3 As shown in FIG. 7, it is preferable that the position where the side 3b is pressed is near the first movable contact 11 and near the second movable contact 13, respectively.
[0037]
(2) Second embodiment
FIG. 8 is a view schematically showing a configuration of a contact device according to a second embodiment of the present invention, and shows a case where a characteristic portion of the present embodiment is applied to the configuration shown in FIG. In the present embodiment, the first fixed contact 14 and the second movable contact 13 are positive contacts, and the second fixed contact 12 and the first movable contact 11 are negative contacts. The material of the first fixed contact 14 is a material having a higher melting point than the material of the second fixed contact 12, the first movable contact 11, and the second movable contact 13. As an example, there is a case where tungsten is used as the material of the first fixed contact 14 and silver is used as the material of the second fixed contact 12, the first movable contact 11, and the second movable contact 13. The other configuration is the same as the configuration shown in FIG. 1, and the attaching operation and the separating operation between the contacts are the same as those shown in FIG.
[0038]
Arcs are generated at the contacts during the operation of attaching between the contacts, and the later attached contacts are more likely to cause bounce due to the collision between the contacts, so that the arc is more likely to occur. Furthermore, for the following reasons, a contact that is easily consumed by an arc can be specified as a positive contact.
[0039]
9A and 9B are diagrams showing experimental results of a change in the contact wear amount with respect to the number of times the contact device is turned on. FIG. 9A shows the wear amount of the positive fixed contact, and FIG. 9B shows the wear of the positive movable contact. 9C shows the sum of the amount and the consumption amount of the negative movable contact, and FIG. 9C shows the consumption amount of the negative fixed contact. FIG. 9 shows an experimental result in the case where the adhesion between the two sets of contacts is performed almost simultaneously, and the materials of all the contacts are the same.
[0040]
Here, assuming that the consumption amount of the positive fixed contact is M1, the consumption amount of the negative movable contact is M2, the consumption amount of the positive movable contact is M3, and the consumption amount of the negative fixed contact is M4, FIGS. From B), M1 = M2 + M3 substantially holds. Also, from FIG. 9C, M4 = 0 substantially holds. Further, when two sets of contacts are considered to have the same condition, M1 + M2 = M3 + M4 holds. From these three equations, (M2 + M3) + M2 = M3 + 0 holds, so that the results of M2 = 0 and M1 = M3 are obtained. Therefore, the result is obtained that the negative electrode contact is hardly consumed and only the positive electrode contact is consumed.
[0041]
Further, the reason why only the positive contact is mainly consumed will be described with reference to FIG. When electrons emitted from the negative electrode contact collide with the positive electrode contact as shown in FIG. 10 (A), the temperature of the surface of the positive electrode contact rises and the positive electrode contact material is activated as shown in FIG. 10 (B). Next, as shown in FIG. 10C, as the gap between the contacts is closed, the metal vapor pressure increases, and metal vapor is ejected. As a result, only the positive contact is mainly consumed.
[0042]
In the present embodiment, based on the above results, a high-melting point material such as tungsten is used only for the positive contact, which is the contact that is easily worn out by the generation of the arc, that is, the first fixed contact 14. Therefore, the wear of the contact can be suppressed without increasing the contact resistance.
[0043]
In the above description, the contact device shown in FIG. 1 has been described as an example. However, in the contact device shown in FIGS. By using a material having a higher melting point, for example, tungsten or the like, consumption of the contact can be suppressed without increasing the contact resistance.
[0044]
Further, a material having a higher melting point than the other contacts may be used for the positive electrode contact to be attached later. For example, even in the configuration shown in FIG. 11, the consumption of the contact can be suppressed without increasing the contact resistance. In FIG. 11, the first fixed contact 14 and the second movable contact 13 are negative contacts, and the second fixed contact 12 and the first movable contact 11 are positive contacts. The material of the first movable contact 11 is a material having a higher melting point than the material of the first fixed contact 14, the second fixed contact 12, and the second movable contact 13, such as tungsten. Further, the same configuration can be applied to the contact device shown in FIGS.
[0045]
【The invention's effect】
As described above, according to the present invention, it is possible to reduce the thrust of the driving device required to peel off the welding between the contacts, so that the size and cost of the contact device can be reduced.
[Brief description of the drawings]
FIG. 1 is a view schematically showing a configuration of a contact device according to a first embodiment of the present invention.
FIG. 2 is a diagram illustrating an attaching operation and a detaching operation of the contact device according to the first embodiment of the present invention.
FIG. 3 is a view schematically showing another configuration of the contact device according to the first embodiment of the present invention.
FIG. 4 is a view schematically showing another configuration of the contact device according to the first embodiment of the present invention.
FIG. 5 is a diagram illustrating an attaching operation and a detaching operation of another contact device according to the first embodiment of the present invention.
FIG. 6 is a view schematically showing another configuration of the contact device according to the first embodiment of the present invention.
FIG. 7 is a diagram illustrating an attaching operation and a detaching operation of another contact device according to the first embodiment of the present invention.
FIG. 8 is a view schematically showing a configuration of a contact device according to a second embodiment of the present invention.
FIG. 9 is a diagram showing an experimental result of a change in a contact consumption amount with respect to the number of times of contact device insertion.
FIG. 10 is a diagram illustrating the reason why only the positive contact is mainly consumed.
FIG. 11 is a view schematically showing another configuration of a contact device according to a second embodiment of the present invention.
[Explanation of symbols]
Reference Signs List 3 movable contact piece, 3a first movable contact side, 3b second movable contact side, 4 contact piece, 7 solenoid, 8a, 8b, 8c, 9 spring, 11 first movable contact, 12 second fixed Contact point, 13 second movable contact point, 14 first fixed contact point, 15 contact piece driving device, 16 plunger, 17 first contact portion, 18 second contact portion.

Claims

A movable contact piece including a first movable contact and a second movable contact at a predetermined interval;
A first fixed contact fixed at a position facing the first movable contact;
A second fixed contact fixed at a position facing the second movable contact;
A contact piece driving device that generates a thrust for driving the movable contact piece,
Has,
A contact device for performing an attaching operation and a separating operation between a first fixed contact and a first movable contact and between a second fixed contact and a second movable contact by a thrust generated by the contact piece driving device. hand,
A first contact portion for pressing the first movable contact side of the movable contact piece away from the first fixed contact at the time of the separating operation; and a second contact portion of the movable contact piece at the time of the separating operation. A second contact portion that presses the movable contact side of the second fixed contact away from the second fixed contact, and having a contact piece connected to the contact piece driving device,
The movable contact piece is swingably supported with respect to the contact piece,
In a state of adhesion between the first fixed contact and the first movable contact and between the second fixed contact and the second movable contact, the distance between the first contact portion and the movable contact piece is And a distance between the second contact portion and the movable contact piece is different.

The contact device according to claim 1, wherein
The first fixed contact and the second movable contact are positive contacts,
The second fixed contact and the first movable contact are negative contacts,
The movable contact piece is configured such that the distance between the second fixed contact and the second movable contact during the attaching operation is shorter than the distance between the first fixed contact and the first movable contact. Supported against the contact piece,
A contact device, wherein the material of the first fixed contact is a material having a higher melting point than the material of the other contacts.

The contact device according to claim 1, wherein
The first fixed contact and the second movable contact are negative contacts,
The second fixed contact and the first movable contact are positive contacts,
The movable contact piece is configured such that the distance between the second fixed contact and the second movable contact during the attaching operation is shorter than the distance between the first fixed contact and the first movable contact. Supported against the contact piece,
The material of the first movable contact is a material having a higher melting point than the material of the other contacts.