JP2005019107A - D.c. relay - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a D.C. relay capable of reducing occurrence of an arc although it has a relatively simple structure allowing current adjustment immediately after a power is supplied. <P>SOLUTION: This D.C. relay 1 is equipped with: a noncontact switch 2 capable of cutting off supply of power; a cutoff part 10 connected in series to the switch 2 and capable of being mechanically cut off; and a resistor R connected in parallel with the switch 2. In supplying power to a load, the switch 2 is previously turned off, the cutoff part 10 is turned on, and the power to the load is limited by interlaying the resister R. Thereafter normal supply of power is carried out by turning on the switch 2. In cutting off the supply of power, the switch 2 is turned off to apply most of the supplied power to the resistor R, and thereafter the cutoff part 10 is turned off to reduce the occurrence of an arc. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【００２１】
配置形態の具体例を図１に示す。図１（Ａ）は配置形態２、図１（Ｂ）は配置形態５、図１（Ｃ）は配置形態１、図１（Ｄ）は配置形態６を示す。図１は、いずれも入力接点１１ａ及び出力接点１１ｂに加え、連結接点１１ｃを具える例を示す。また、連結接点１１ｃは、駆動部１２により駆動される可動接点としている。連結接点１１ｃには、入力接点１１ａと接続又は切り離し可能な入力側連結接点１１ｄ、出力接点１１ｂと接続又は切り離し可能な出力側連結接点１１ｅを具える。図１（Ａ）は、入力側連結接点１１ｄと出力側連結接点１１ｅ間に、並列に配置した無接点スイッチ及び抵抗Ｒを具える構成である。また、図１（Ｄ）は、遮断部１０において、更に第二連結接点１３ｃを具えて、４組の接点対を具える例を示す。連結接点１３ｃには、出力接点１１ｂに接続される第二入力接点１３ａと接続又は切り離し可能な第二入力側連結接点１３ｄ、第二出力接点１３ｂと接続又は切り離し可能な第二出力側連結接点１３ｅを具える。
【００２２】
上記構成を具える本発明リレーは、負荷に電力を供給する際、無接点スイッチをオフにしておき、遮断部をオンにし、一定時間後、無接点スイッチをオンにして負荷に電力を供給し、負荷への電力供給を遮断する際、無接点スイッチをオフにした後、遮断部をオフにするように構成することが好ましい。
【００２３】
この構成では、電力投入直後において、無接点スイッチをオフにしておき、抵抗を介することで電流の調整を行い、電流を制限した状態で電力を供給する。そして、一定時間、即ち、負荷に具えるコンデンサが十分充電された後、無接点スイッチをオンにして電流の制限を停止し、負荷に通常の電力を供給する。即ち、本発明リレーは、抵抗を利用して、負荷への電力の供給にあたり従来のリレーユニットと同様に電流の調整を行うことができる。
【００２４】
また、この構成において通常の電力の供給は、無接点スイッチをオンにしておき、無接点スイッチを介して行う。従って、無接点スイッチは、通常の通電電流及び通電電圧に十分耐え得るものを使用する。
【００２５】
一方、電力の供給を遮断する際は、アークが生じない無接点スイッチをまずオフにする。このとき、電力は、抵抗を介して供給され、供給電圧のほとんどが抵抗に印加されるため、遮断部の接点は、電位差がほとんどない状態となり、遮断部をオフにする際には、アークが生じにくくなる、或いは全く生じない。本発明リレーは、このように抵抗を用いることで、アークの発生を低減する、或いはなくすことができ、気体の密閉構造を用いていない簡易な構成でありながら、高速遮断が可能である。特に、遮断部に連結接点を具える場合、接点対が多いことで、接点対一つ当りに加わる電圧を小さくし、無接点スイッチが故障するなどして遮断部に加えられる供給電圧の低減が十分にできなかった場合であっても、アークをより発生しにくくすることができる。
【００２６】
上記入力接点、出力接点や、連結接点は、銅などの導電性部材に設けるとよい。上記遮断部が入力接点及び出力接点のみを具える場合、一方の接点を設けた導電性部材を絶縁性材料からなるベースに配置し、このベースに駆動部を連結して可動接点とするとよい。上記遮断部が更に連結接点を具える場合、入力側連結接点、出力側連結接点を銅などの導電性部材に設け、これら導電性部材を絶縁性材料からなるベースに配置し、このベースに駆動部を連結するとよい。
【００２７】
接点の開閉を行う駆動部の駆動源は、種々のものが利用できる。例えば、ソレノイドやシリンダなどの直動系駆動源、モータなどの回転系駆動源が挙げられる。直動系駆動源を用いる場合、接点を設けた導電性部材、又は接点を設けた導電性部材を配置した絶縁性のベースに直動系駆動源を連結して接点を開閉させるとよい。回転系駆動源を用いる場合は、回転運動を往復運動に変換する変換機構を介して接点の開閉を行うとよい。
【００２８】
無接点スイッチのオン／オフの制御は、制御回路を具えて行うとよい。本発明リレーでは、電力投入直後、抵抗を介して負荷に電力供給を行うため、遮断部をオンにしてから一定時間後に無接点スイッチをオンにする。そこで、無接点スイッチの制御回路として、遮断部をオンにした時間よりも無接点スイッチをオンにする時間を遅らせるための抵抗Ｒ_１とコンデンサとを具える構成のものが挙げられる。無接点スイッチをオンにする時間は、抵抗Ｒ_１とコンデンサとの積により調整するとよい。このような制御回路は、自動車などに搭載されている制御装置のＥＣＵ（Ｅｌｅｃｔｒｉｃ Ｃｏｎｔｒｏｌ Ｕｎｉｔ、電子制御装置）などのＭＰＵ（マイクロコンピュータ）と接続可能にしておく。
【００２９】
遮断部のオン／オフの制御は、ＥＣＵ（Ｅｌｅｃｔｒｉｃ Ｃｏｎｔｒｏｌ Ｕｎｉｔ、電子制御装置）などのＭＰＵ（マイクロコンピュータ）を搭載した制御機器を用いて適宜行ってもよい。例えば、自動車に既存の制御装置に本発明リレーを取り付けて、この既存の制御装置に本発明リレーの駆動機能を追加して用いてもよい。このとき、リレー自体の構成部品をより低減することができると共に、既存の制御装置を用いることで、低コストにすることができる。
【００３０】
また、遮断部のオン／オフを制御する制御回路を本発明リレーに具えていてもよい。このような制御回路は、例えば、信号の制御を行うＭＰＵ（マイクロコンピュータ）と、低電圧電源（例えば、１２Ｖ）に接続されると共に、ＭＰＵなどの電源となる電源回路と、駆動部への信号の制御を行う半導体スイッチやリレーとを具える構成が挙げられる。このように遮断部のオン／オフの制御及び無接点スイッチのオン／オフを行う制御回路を具えた本発明リレーは、自動車などへの取り付け作業性に優れて好ましい。
【００３１】
上記遮断部のオン／オフを制御する制御回路は、無接点スイッチのオン／オフを行う制御回路と別個に具えていてもよいが、両者の制御回路を一体の回路とすると、回路の占有面積をより小さくすることができて好ましい。
【００３２】
更に、短絡事故などの事故の際、過大な電流が負荷に流れて火災などの重大な事態を回避するべく、過電流が流れた際、少なくとも無接点スイッチをオフにする構成を具えることが好ましい。具体的には、例えば、負荷に供給される電流を測定する電流センサを具えておくことが挙げられる。電流センサは、例えば、ホール素子やカレントトランスなどが挙げられる。電流センサからの情報（測定データ）は、本発明リレーを取り付けた制御装置のＭＰＵや本発明リレーに具える制御回路のＭＰＵに伝達して、電流値が閾値超となった際、無接点スイッチをオフにするような回路を構成するとよい。
【００３３】
その他の構成として、例えば、無接点スイッチの制御回路を工夫することが挙げられる。例えば、無接点スイッチの電位、より具体的にはソース・ドレイン間の電位差と閾電位とを比較する比較器を具え、無接点スイッチの電位が閾電位を超えた際、無接点スイッチに過電流が流れたと判定し、無接点スイッチをオフにするように構成された制御回路を具えていてもよい。上記制御回路は、無接点スイッチに流れる電流と、ソース・ドレイン間の電位差が比例の関係にあることを利用して、比較器によりソース・ドレイン間の電位差と閾電位とを比較し、ソース・ドレイン間の電位差が閾電位を超えた場合、過電流が生じていると判定し、無接点スイッチをオフにする構成である。いわゆるラッチ回路と呼ばれる保護回路を用いてもよい。比較器としては、コンパレータなどが挙げられる。
【００３４】
上記構成を具える本発明リレーは、過電流が生じた際、無接点スイッチをオフにすることで、抵抗を介して電流がながれるため、抵抗により電力エネルギーを消費させることができる。そのため、負荷への過大な電流の投入を無くすことができる、或いは制限することができる。このように事故時などに発生する過大な電流を無くす又は制限することで、配線や負荷などが異常加熱するなどの事態を回避し易い。
【００３５】
更に、無接点スイッチに加えて、遮断部をオフにして、電力供給を完全に断つこともできる。
【００３６】
【発明の実施の形態】
以下、本発明の実施の形態を説明する。本実施形態は、表１に示す配置形態２に示すものである。
図２は、本発明直流リレーの概略を示す回路図である。本例に示す直流リレー１は、負荷への電力の供給を遮断可能な無接点スイッチ２と、無接点スイッチ２と直列に接続されると共に、機械的に遮断可能な遮断部１０と、無接点スイッチ２と並列に接続される抵抗Ｒとを具える。以下、各構成をより詳しく説明する。
【００３７】
＜無接点スイッチ＞
本例において無接点スイッチ２は、ワイドギャップ半導体からなるＦＥＴを用いた。また、本例は、無接点スイッチ２のオン／オフの制御を行う制御回路を具えている。
【００３８】
図３（Ａ）は、無接点スイッチのオン／オフの制御を行う制御回路の一例を示す回路図、（Ｂ）は、無接点スイッチをオンにする時間を遮断部よりも遅らせることが可能な回路図である。無接点スイッチ２に具える制御回路としては、例えば、図３（Ａ）に示す構成が挙げられる。この制御回路は、無接点スイッチ２に電力の供給を行う電源回路と接続可能な電源端子２ａ、２ｃと、電源端子２ａ、２ｃ間に配置されて制御回路の電圧を一定に保つためのキャパシタＣと、無接点スイッチ２へのオン／オフの信号（電圧）を与えるための抵抗Ｒ_１、Ｒ_２と、負荷に流れる大電流系から制御回路に電流が流れるのを防止するためのダイオードＤ_１とを具える。更に、図３（Ｂ）に示すようにコンデンサＣ_ｔを具えて、抵抗Ｒ_１とコンデンサＣ_ｔとの積により、無接点スイッチをオンにする時間を調整可能な回路としてもよい。本発明リレーは、遮断部をオンにして電力投入を開始してから一定時間後に無接点スイッチをオンにする。このとき、図３（Ｂ）に示すような制御回路とすると、無接点スイッチ２をオンにする時間をコンデンサＣ_ｔ及び抵抗Ｒ_１により遮断部よりも遅らせることができる。
【００３９】
＜遮断部＞
《接点》
図４は、本発明直流リレーの概略を示す上面図、図５は、その正面図、図６は、その分解構成図である。本例に示す遮断部１０は、入力接点１１ａ及び出力接点１１ｂに加えて、連結接点１１ｃを具える構成である。連結接点１１ｃは、入力接点１１ａと接続又は切り離し可能な入力側連結接点１１ｄ、出力接点１１ｂと接続又は切り離し可能な出力側連結接点１１ｅを具える。従って、入力接点１１ａと入力側連結接点１１ｄとで一組の接点対をなし、出力接点１１ｂと出力側連結接点１１ｅとで一組の接点対をなし、合計二組の接点対を具える構成である。
【００４０】
入力接点１１ａ、出力接点１１ｂは、それぞれ別個の導電性部材の一面に形成した。入力接点１１ａを設けた導電性部材には、電源Ｖに接続可能な端子１０Ａ、出力接点１１ｂを設けた導電性部材には、負荷に接続可能な端子１０Ｂを設けている。
【００４１】
入力側連結接点１１ｄ、出力側連結接点１１ｅも入力接点１１ａ、出力接点１１ｂと同様に、それぞれ別個の導電性部材１２ｆ、１２ｇの一面に形成した。そして、これら導電性部材１２ｆ、１２ｇ間に無接点スイッチ２及び抵抗Ｒを並列させて配置している。これら導電性部材１２ｆ、１２ｇ、無接点スイッチ２及び抵抗Ｒは、絶縁性材料からなるベース１２ｃに配置している。
【００４２】
《駆動部》
駆動部１２の駆動源として、本例では、ソレノイド１２ａを用いている。本例では、導電性部材１２ｆ、１２ｇ、無接点スイッチ２及び抵抗Ｒを搭載したベース１２ｃに駆動部１２のソレノイド１２ａを連結して、上記二組の接点対の開閉を行う。即ち、本例では、連結接点１１ｃを駆動部１２により駆動可能な可動接点とし、入力接点１１ａ及び出力接点１１ｂを固定接点とする。ソレノイド１２ａには、ソレノイド１２ａに電力の供給を行う電源端子１２ｄ、１２ｅが連結され、電流の供給／停止により適宜遮断部１０のオン／オフを行う。本例において遮断部１０のオン／オフの制御、即ち、ソレノイド１２ａへの電力の供給は、例えば、自動車に搭載される既存の制御装置に遮断部１０の駆動機能を追加することで行う。
【００４３】
＜動作説明＞
《電力投入動作》
本例に示す直流リレー１において、負荷に電力を供給する際の動作を説明する。まず、無接点スイッチ２をオフにしておき、遮断部１０をオンにするべく、入力接点１１ａと入力側連結接点１１ｄ、及び出力接点１１ｂと出力側連結接点１１ｅを接触させる。このとき、電源Ｖ→入力接点１１ａ→入力側連結接点１１ｄ（導電性部材１２ｆ）→抵抗Ｒ→出力側連結接点１１ｅ（導電性部材１２ｇ）→出力接点１１ｂ→負荷→電源Ｖという閉ループが形成され、抵抗Ｒを介して負荷に電力が供給される。このように電力投入直後は、抵抗Ｒを介すことで、電流の制限を行う。
【００４４】
一定時間経過後、無接点スイッチ２をオンにする。このとき、電源Ｖ→入力接点１１ａ→入力側連結接点１１ｄ（導電性部材１２ｆ）→無接点スイッチ２→出力側連結接点１１ｅ（導電性部材１２ｇ）→出力接点１１ｂ→負荷→電源Ｖという閉ループが形成され、無接点スイッチ２を介して負荷に電力が供給される。このように通常時の電力の供給は、無接点スイッチ及び遮断部を介して行う。なお、無接点スイッチ２の制御回路として図３（Ａ）に示す構成とした場合、一定時間経過後、無接点スイッチがオンになるようにＭＰＵなどにて制御するとよい。一方、図３（Ｂ）に示す構成とした場合、抵抗Ｒ_１とコンデンサＣ_ｔとにより、無接点スイッチをオンにするタイミングを制御することができる。即ち、回路構成により、無接点スイッチを制御可能である。
【００４５】
上記のように電力の投入開始直後には、抵抗Ｒを介して負荷に電力を供給することで、抵抗Ｒが電力エネルギーを消費することから、負荷への電力を制限することができる。従って、負荷に具えるコンデンサに十分に充電させることができ、電力の投入直後に負荷に大きな電流が流れて負荷が破壊されるといった不具合を効果的に防止することができる。即ち、本発明リレーは、従来のリレーユニットと同様に電流調整を行うことができる。
【００４６】
なお、通常時の電力供給の際は、無接点スイッチだけでなく、抵抗Ｒにも電流が流れることになるが、電流は、抵抗値が小さい無接点スイッチに主に流れることになる。
【００４７】
《電力遮断動作》
次に、負荷への電力を遮断する際の動作を説明する。電力供給時は、上記のように無接点スイッチ２及び遮断部１０がオンの状態である。この状態から電力の供給を遮断する際は、まず、無接点スイッチ２をオフにする。このとき、無接点スイッチ２は、機械的な切り離しを行わないため、アークが発生することがない。
【００４８】
次に、遮断部１０をオフにするべく、駆動部１２によりベース１２ｃを駆動して、入力接点１１ａと入力側連結接点１１ｄ間、出力側連結接点１１ｅと出力接点１１ｂ間を切り離す。このとき、無接点スイッチ２をオフにしていることで、電流は、抵抗Ｒを介して流れることになる。即ち、供給電圧の大部分が抵抗Ｒの両端に印加されることで、遮断部１０の各接点対には、ほとんど電位差が生じない状態となっている。この状態で、遮断部１０をオフにすると、アークが生じにくい、或いは全く生じない。
【００４９】
上記のように本発明リレーは、電流調整を行うことができると共に、気体の密封構造を用いない簡易な構成でアークの発生を低減、或いは全く無くすことができ、高速遮断を可能とする。また、本例に示すリレーでは、無接点スイッチが故障するなどして供給電圧が抵抗に十分に印加されない場合であっても、接点対を多数具えることで接点対一つ当りに加わる電圧を小さくすることができるため、アークの発生を効果的に低減することが可能である。
【００５０】
［遮断部の制御回路を具える例１］
上記の例では、遮断部のオン／オフを制御する制御装置を別途設ける構成について説明したが、本発明リレーには、遮断部のオン／オフの制御を行う制御回路を具えていてもよい。図７は、半導体スイッチを具える制御回路の回路図である。
【００５１】
図７に示す制御回路は、無接点スイッチのオン／オフを制御すると共に、駆動部のソレノイドの動作を制御するＭＰＵと、ＭＰＵなどを駆動する電源回路と、ＭＰＵからのオン／オフ信号を受けてソレノイドの駆動電流の制御を行う半導体スイッチＱ_１とを具える。また、この制御回路は、フルブリッジトランスＴｒ、半導体スイッチＱ_１１、Ｑ_１２、Ｑ_１３、Ｑ_１５からなるフルブリッジ構成としており、無接点スイッチの制御回路への電力供給を行う。本例では、トランスＴｒによって、遮断部の制御回路の電源と、無接点スイッチの制御回路の電源とを絶縁分離する。その他、この回路は、半導体スイッチＱ_１１、Ｑ_１２にＭＰＵからの駆動信号を伝えるための半導体スイッチＱ_１４、Ｑ_１６、半導体スイッチＱ_１１の駆動電圧を与える抵抗Ｒ_１１、Ｒ_１２、半導体スイッチＱ_１２の駆動電圧を与える抵抗Ｒ_１３、Ｒ_１４、半導体スイッチＱ_１の駆動電圧を与える抵抗Ｒ_１５、Ｒ_１６を具える。本例において半導体スイッチＱ_１は、低電圧駆動タイプ（〜４Ｖ）のＮ型チャンネル電界効果形トランジスタを用いた。
【００５２】
このような制御回路は、高電圧の電源と別に具える低電圧電源（例えば、１２Ｖ）に接続される共に、接地される。この低電圧電源に接続される端子１２ｅ’には、駆動部のソレノイドの電源端子１２ｅ、半導体スイッチＱ_１と接続される端子１２ｄ’には、ソレノイドの電源端子１２ｄがそれぞれ接続される。また、無接点スイッチの制御回路の電源端子２ａ、２ｃが、フルブリッジトランスＴｒからダイオードＤ_１１、Ｄ_１２を介して端子２ａ’、２ｃ’に接続される。
【００５３】
上記構成により、駆動部のソレノイドは、ＭＰＵからの信号により、半導体スイッチＱ_１がオン／オフすることによって、駆動電流が制御される。
【００５４】
このように遮断部の制御回路もリレーに具えて一体化した構成とすると、自動車などに取り付ける際の作業性がよく好ましい。
【００５５】
［遮断部の制御回路を具える例２］
上記例１では、半導体スイッチＱ_１を具える制御回路について説明したが、機械的な遮断を行うリレーを用いた回路でもよい。図８は、機械的な遮断を行うリレーを具える制御回路の回路図である。
【００５６】
図８に示す制御回路は、基本的構成は図７に示す回路図と同様であり、無接点スイッチのオン／オフを制御すると共に、駆動部のソレノイドの動作を制御するＭＰＵと、ＭＰＵなどを駆動する電源回路とを具える。異なる点は、ＭＰＵからのオン／オフ信号により動作する半導体スイッチＱ_２と、半導体スイッチＱ_２のオン／オフにより制御されてソレノイドの駆動電流の制御を行う機械的な遮断が可能なリレーＲＬＹ_１とを具える点である。本例において半導体スイッチＱ_２は、ＮＰＮトランジスタを用いた。
【００５７】
機械的な遮断を行うリレーにより、駆動部のソレノイドのオン／オフを制御する制御回路とすることで、半導体スイッチＱ_１により制御を行う図７に示す制御回路よりも安価に作製することができる。
【００５８】
［無接点スイッチの制御回路及び遮断部の制御回路を具える例］
上記例１、２では、無接点スイッチの制御回路と遮断部の制御回路とを別々に具える例を説明したが、無接点スイッチの制御回路と、遮断部の制御回路とを一体の回路としてもよい。図９は、図３（Ｂ）に示す無接点スイッチの制御回路と、図７や図８に示す遮断部の制御回路とを組み合わせた制御回路を示す回路図である。図９では、半導体スイッチＱ_１、Ｑ_２、リレーＲＬＹ_１を省略している。
【００５９】
このように無接点スイッチの制御回路と、機械的な遮断を行う遮断部の制御回路とを一体の回路とすることで、回路の占有面積を小さくすることができると共に、両制御回路を別個に作製する必要が無く作業性に優れる。
【００６０】
［過電流が流れた際の対策１］
次に、短絡事故などが生じた際、無接点スイッチを遮断できる構成を具える制御回路を説明する。短絡事故などの事故が生じると、大きな電流が発生し、負荷に過電流が流れる恐れがある。そこで、本例の制御回路は、コンパレータを具え、コンパレータを利用して、過電流の際、無接点スイッチをオフにする構成である。図１０は、無接点スイッチの制御回路としてコンパレータを具える制御回路と遮断部の制御回路とを組み合わせた回路図である。
【００６１】
図１０に示す制御回路は、基本的構成は図３（Ａ）に示す無接点スイッチの制御回路と、図７又は図８に示す遮断部とを組み合わせた制御回路と同様である。この回路の特徴とする点は、無接点スイッチの制御回路においてコンパレータＣＯＭＰを具える点にある。以下、この点を中心に説明する。なお、図１０では、半導体スイッチＱ_{１ 、}Ｑ_２やリレーＲＬＹ_１を省略している。
【００６２】
この制御回路は、コンパレータＣＯＭＰにて無接点スイッチのソース・ドレイン間の電位差と閾電位とを比較して、ソース・ドレイン間の電位差が閾電位を超えた場合、無接点スイッチに過電流が流れたと判定し、半導体スイッチＱ_２１をオンとする。半導体スイッチＱ_２１のオンに伴い半導体スイッチＱ_２０、Ｑ_３がオンになる。この半導体スイッチＱ_３がオンとなることにより、無接点スイッチ２をオフにすることができる。
【００６３】
このように短絡事故などが生じた際、少なくとも無接点スイッチをオフにするように構成しておくと、抵抗により電力エネルギーが消費されることで、過電流が負荷にほとんど送られることがない。従って、短絡事故などによる負荷へのダメージをほとんどなくす、或いは防止することができる。また、無接点スイッチを遮断した後、更に遮断部を遮断するように構成すると、負荷への過電流によるダメージをより確実に防止することができ、短絡事故などの事故において、負荷が損傷、破壊されることを効果的に防ぐことが可能である。
【００６４】
なお、図１０に示す回路では、ソース・ドレイン間の電位差が閾電位超になると、半導体スイッチＱ_２０がオンとなり、ダイオードＤ_２を経由して、コンパレータＣＯＭＰの出力をオンにし続けることができる。また、図１０に示す回路では、半導体スイッチＱ_３に駆動電圧を与える抵抗Ｒ_２０、Ｒ_２１、半導体スイッチＱ_３への電流を調整する抵抗Ｒ_２４及びダイオードＤ_２、半導体スイッチＱ_２０に駆動電圧を与える抵抗Ｒ_２２、Ｒ_２３、コンパレータＣＯＭＰの−側に駆動電圧を与える抵抗Ｒ_２５、Ｒ_２６、コンパレータＣＯＭＰの＋側に駆動電圧を与える抵抗Ｒ_２７、Ｒ_２８を具える。
【００６５】
［過電流が流れた際の対策２］
上記対策１では、無接点スイッチの制御回路を工夫することで、過電流が流れた際、負荷の損傷などを防止することを説明した。その他の対策としては、負荷に供給される電流を測定する電流センサ４０を具えることが挙げられる。図１１は、無接点スイッチの制御回路と遮断部の制御回路とを組み合わせた回路図であって、更に電流センサを具える例を示す。この制御回路は、基本的構成は図３（Ａ）に示す無接点スイッチの制御回路と、図７又は図８に示す遮断部とを組み合わせた制御回路と同様である。この回路の特徴とする点は、電流センサを具える点にある。なお、図１１では、半導体スイッチＱ_{１ 、}Ｑ_２やリレーＲＬＹ_１を省略している。
【００６６】
本例において電流センサ４０は、ホール素子を用いた。このような電流センサ４０は、制御回路のＭＰＵに連結して、例えば、図１１に示すように無接点スイッチの近傍に流れる電流を測定できるように配置するとよい。そして、測定した電流値をＭＰＵに送り、ＭＰＵにて規定の閾値と比較して、閾値を超える電流が流れている場合、ＭＰＵは、無接点スイッチをオフにする信号を送るように構成するとよい。
【００６７】
このように電流センサを設けることでも、短絡事故などの際の過電流による不具合を効果的に防止することができる。また、電流センサを具える場合も、無接点スイッチだけでなく、遮断部をもオフにする構成としておくと、配線や負荷などの異常加熱などといった事態をより回避し易い。
【００６８】
図１１では、無接点スイッチの制御回路と遮断部の制御回路とが一体になった回路に電流センサを具える例を示したが、図２、３に示すように無接点スイッチの制御回路のみを具える場合に電流センサ４０を設けてももちろんよい。また、図７、８に示すように遮断部の制御回路のみを具える場合に電流センサ４０を設けてももちろんよい。
【００６９】
【発明の効果】
以上、説明したように本発明直流リレーによれば、部品点数が少なく、電力投入時の電力調整を行うことができ、簡易な構成でありながら、アークを低減する、或いはなくすことができるという優れた効果を奏し得る。特に、本発明リレーでは、従来のような複雑で高価な気体の密封構造を用いておらず、長期に亘り優れた遮断性能を維持することができる。更に、本発明リレーは、簡易な構成であることから、コストの低減も図ることが可能である。
【図面の簡単な説明】
【図１】本発明直流リレーの構成を模式的に示す説明図であって、（Ａ）は遮断部の連結接点間に無接点スイッチ及び抵抗を配置する例、（Ｂ）は負荷よりも電源の高電位側に無接点スイッチ及び抵抗を配置し、負荷よりも電源の低電位側に遮断部を配置する例、（Ｃ）は無接点スイッチ及び抵抗と遮断部とを負荷よりも電源の高電位側に配置する例、（Ｄ）は負荷よりも電源の高電位側に多接点の遮断部を配置し、負荷よりも電源の低電位側に無接点スイッチ及び抵抗を配置する例である。
【図２】本発明直流リレーの概略を示す回路図である。
【図３】（Ａ）は、無接点スイッチのオン／オフの制御を行う制御回路の一例を示す回路図、（Ｂ）は、（Ａ）に示す回路に更にコンデンサＣ_ｔを具える回路図である。
【図４】本発明直流リレーの概略を模式的に示す上面図である。
【図５】図４に示す本発明直流リレーの正面図である。
【図６】図４に示す本発明直流リレーの分解構成図である。
【図７】本発明直流リレーに具える遮断部のオン／オフの制御を行う制御回路の一例を示す回路図であり、半導体スイッチを具える制御回路である。
【図８】本発明直流リレーに具える遮断部のオン／オフの制御を行う制御回路の一例を示す回路図であり、機械的な遮断を行うリレーを具える制御回路である。
【図９】本発明直流リレーに具える制御回路の一例を示す回路図であり、無接点スイッチの制御回路と、遮断部の制御回路とを組み合わせた制御回路である。
【図１０】本発明直流リレーに具える制御回路の一例を示す回路図であり、短絡事故時などで無接点スイッチを遮断可能な制御回路である。
【図１１】本発明直流リレーに具える制御回路の一例を示す回路図であり、電流センサを具える回路である。
【図１２】ＨＥＶに用いられている従来のリレーユニットを説明する概略回路図である。
【符号の説明】
１ 直流リレー ２ 無接点スイッチ ２ａ、２ｃ 電源端子 ２ａ’、２ｃ’ 端子
１０ 遮断部 １０Ａ、１０Ｂ 端子 １１ａ 入力接点 １１ｂ 出力接点 １１ｃ 連結接点
１１ｄ 入力側連結接点 １１ｅ 出力側連結接点 １２ 駆動部 １２ａ ソレノイド
１２ｃ ベース １２ｄ、１２ｅ 電源端子 １２ｄ’、１２ｅ’ 端子 １２ｆ、１２ｇ 導電性部材
１３ａ 第二入力接点 １３ｂ 第二出力接点 １３ｃ 第二連結接点
１３ｄ 第二入力側連結接点 １３ｅ 第二出力側連結接点
４０ 電流センサ
１００ リレーユニット １０１ 第一リレー １０２ 第二リレー １０３ 第三リレー
１０４ 抵抗 １０５ 電源 １０６ サービスプラグ １０７ 電圧ヒューズ[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a direct current relay capable of interrupting power supply to a load. In particular, the present invention relates to a smaller DC relay that can effectively suppress the generation of an arc and cut off the power supply and has a small number of components.
[0002]
[Prior art]
In recent years, automobiles that drive motors and the like with a high voltage (about 300 V) such as hybrid cars (HEV) and fuel cell cars have been developed due to environmental problems. These automobiles have a DC high-voltage power source that supplies power to electric devices (loads) such as motors, and perform mechanical connection or disconnection as a shut-off mechanism that electrically connects or disconnects the power source and the load. A relay unit using a DC relay is used.
[0003]
FIG. 12 is a schematic circuit diagram for explaining a conventional relay unit used in HEV. The relay unit 100 includes a plurality of DC relays 101 to 103 and a resistor 104 that perform mechanical disconnection. Specifically, the first relay 101 is provided on the high potential side of the power source 105, and the second relay 102 is provided in series with the power source 105 on the lower potential side of the power source 105 than the load. A third relay 103 and a resistor 104 are provided in parallel with the first relay 101. Note that a service plug 106 and a voltage fuse 107 are provided in the vicinity of the power source 105 as means for opening circuits other than the relay unit 100.
[0004]
In supplying power to the load using the relay unit 100, immediately after the power is turned on, a current is passed through the resistor 104, and after a while, normal power is supplied through the first relay 101 and the second relay 102. . Specifically, the first relay 101 is turned off, the second relay 102 and the third relay 103 are turned on in order, and the application of power to the load via the resistor 104 is started. The relay 101 is turned on and power is supplied to the load via the first relay 101 and the second relay 102.
[0005]
When interrupting the DC high voltage as described above, unlike AC, there is no point at which the current becomes zero. Therefore, the generated arc is very large and it is very difficult to interrupt in a short time. Therefore, conventionally, as a DC relay used in a relay unit, a structure has been proposed in which a gas having a large cooling effect, such as hydrogen, is enclosed in an arc generation unit to suppress the generation of an arc (see, for example, Patent Document 1).
[0006]
[Patent Document 1]
Japanese Patent Laid-Open No. 9-320411
[Problems to be solved by the invention]
However, the conventional relay unit has a problem that the number of parts is large and the size is increased.
[0008]
The load may have a large capacity capacitor. For this reason, immediately after the start of power supply, if current is supplied immediately through the first relay without limiting the current through the resistor, an overcurrent may flow through the load and the load may be destroyed. Therefore, immediately after the start of power supply, power is supplied through the resistor as described above so as to limit the current so that the capacitor can be sufficiently charged. Thus, in order to adjust the current immediately after the start of power application, conventionally, the relay unit has three DC relays as shown in FIG. However, these three DC relays have independent structures each having a driving mechanism such as a solenoid for opening and closing, and therefore, the number of parts of the relay unit is large and tends to be large.
[0009]
Moreover, in the structure which suppresses an arc using a gas as shown to patent document 1 as a direct current relay, it is very difficult to reduce in size, without reducing performance in the apparatus mounted in the limited space called a motor vehicle. . In the structure described in Patent Document 1, a case structure capable of completely sealing a gas is required. However, in addition to hermeticity, in consideration of heat resistance against a high-temperature arc of several thousand degrees Celsius to 10,000 degrees Celsius, In order to increase the area of the hermetic joint, the thickness of the case has to be very large, which increases the size of the case. Even if the case is made thick in this way, it is difficult to keep the gas sealed without maintenance for a long period of time.
[0010]
Furthermore, the case is made of a material such as ceramic that can withstand high temperatures of several thousand degrees C. or more, and the structure is complicated, so that the economy is poor.
[0011]
Accordingly, an object of the present invention is to provide a direct current relay that can adjust the current immediately after the start of power supply and that can effectively suppress an arc with a simpler configuration with fewer parts.
[0012]
[Means for Solving the Problems]
The present invention achieves the above-mentioned object by using a combination of a breaker that can be mechanically cut off and a contactless switch.
[0013]
That is, the present invention is a direct current relay that is connected to a power source and a load and can cut off the supply of power to the load, the contactless switch that can cut off the supply of power, and the contactless switch in series In addition to being connected, it includes a shut-off portion that can be mechanically shut off and a resistor connected in parallel with the contactless switch.
[0014]
The present invention includes a contactless switch, thereby reducing the number of driving means for opening and closing contacts such as solenoids, reducing the number of parts, and realizing miniaturization. In addition, since the contactless switch does not generate an arc when it is turned off, unlike the interruption unit that performs mechanical interruption, the contactless switch is turned off before the interruption unit when the power supply is interrupted. By doing so, the arc can be effectively reduced. Furthermore, not only a non-contact switch but also a breaker capable of mechanical breakage can be provided, so that the circuit can be reliably cut off. At this time, when the contactless switch is turned off first, most of the supply voltage is applied to the resistor provided in parallel with the contactless switch, and there is almost no potential difference between the contacts of the interrupting portion. Therefore, when the non-contact switch is turned off and then the interrupting portion is turned off, an arc is hardly generated or not generated at all. In addition, since the current can be adjusted by the resistance immediately after the start of power supply, the current can be limited. Therefore, the present invention can provide a DC relay that does not deteriorate the arc extinguishing performance of the arc and is smaller and has a current adjustment function. Moreover, since it is not the arc extinguishing structure using gas like the past, it does not become a large-sized and complicated structure, and sufficient performance can be maintained over a long period of time. Hereinafter, the present invention will be described in more detail.
[0015]
In the present invention, the contactless switch is preferably made of a semiconductor. Examples of contactless switches made of semiconductors include transistors, JFETs (junction field effect transistors), FETs (field effect transistors), bipolar transistors, thyristors, GTOs (gate turn-off thyristors), IGBTs (insulated gate bipolar transistors), and the like. Is mentioned. In particular, a material made of a wide bandgap semiconductor such as SiC or GaN is preferable to a material made of a Si-based semiconductor because it has a high withstand voltage and can carry a large current. Such a non-contact switch may be arranged on either the low potential side (low side) or the high potential side (high side) of the power supply with respect to the load.
[0016]
When a non-contact switch made of a semiconductor is used, a leakage current flows through the semiconductor even when the semiconductor is cut off. However, it is desirable to eliminate the leakage current in an automobile with limited power. The relay of the present invention includes a breaker that can be mechanically interrupted in series with the contactless switch, so that the circuit can be completely electrically insulated and leakage current can be effectively prevented. Can do. The blocking part is provided with a pair of contacts that can be opened and closed. The contact pair may be opened and closed with a drive unit described later. The contact pair includes an input contact and an output contact. Although both the input contact and the output contact may be movable contacts, in that case, since the number of driving units increases, it is preferable that one is a fixed contact and the other is a movable contact.
[0017]
Furthermore, not only the input contact and the output contact, but also a connection contact capable of connecting or disconnecting the input contact and the output contact in series may be provided to increase the number of contact pairs. The connection contact may include an input side connection contact that can be connected to or disconnected from the input contact, and an output side connection contact that can be connected to or disconnected from the output contact. At this time, the input contact and the output contact may be fixed contacts, and the connection contact may be a movable contact driven by a drive unit. By providing a plurality of contact pairs, such as a contact pair consisting of input contacts and input-side connection contacts, and a contact pair consisting of output contacts and output-side connection contacts, the non-contact switch will fail and the supply voltage will Even if it is directly applied to the interrupting portion without being interposed, it is possible to make it difficult to generate an arc by dividing the voltage to a plurality of contact pairs and reducing the voltage applied to each contact pair.
[0018]
Further, the present invention includes a resistor in parallel with the contactless switch. This resistor may be the same as that of a conventional relay unit, for example.
[0019]
Table 1 shows specific arrangements of the non-contact switch, the resistor, and the blocking unit. In Table 1, “non-contact” is a non-contact switch. As an arrangement form, when the non-contact switch and the resistor and the cut-off part are arranged on the high side of the power supply rather than the load (arrangement form 1 and 2), the non-contact switch, the resistor and the cut-off part are arranged on the low side of the power supply from the load In the case of disposing the switches (disposition forms 3 and 4), the contactless switch and the resistor are disposed on the high side of the power supply from the load, and the breaker is disposed on the low side of the power supply from the load (arrangement form 5). A case where the switch and the resistor are arranged on the low side of the power source from the load and the cutoff unit is arranged on the high side of the power source from the load (arrangement form 6) is exemplified. In any arrangement, the blocking section may be configured to include a set of contact pairs including an input contact and an output contact, or may be configured to include a plurality of contact pairs including a connection contact. In the above arrangement form, as shown in arrangement forms 5 and 6, either one of the non-contact switch and the blocking unit is on the high potential side of the high voltage power supply (for example, about 300V) from the load, and the other is the high voltage power supply from the load. It is preferable to arrange on the low potential side. With this configuration, even when the electric wire on either side of the high-voltage power supply is short-circuited with the low-voltage body ground, it is possible to prevent a large current from flowing through the load. In an in-vehicle system such as a hybrid car, a high-voltage power supply and a low-voltage load are insulated and separated by a transformer, and a low-voltage battery (for example, 12V) provided in the low-voltage system is usually body-grounded. Since the body ground and the high potential side of the high voltage power supply have different potentials, either the body ground and the high potential side wire or the body ground and the low potential side wire are short-circuited. However, a large current may flow through the load. However, it is possible to effectively prevent an excessive current from flowing to the load by providing a non-contact switch and a cut-off section on both the high potential side and the low potential side of the high voltage power source.
[0020]
[Table 1]

[0021]
A specific example of the arrangement form is shown in FIG. 1A shows an arrangement form 2, FIG. 1B shows an arrangement form 5, FIG. 1C shows an arrangement form 1, and FIG. FIG. 1 shows an example in which a connection contact 11c is provided in addition to an input contact 11a and an output contact 11b. The connecting contact 11 c is a movable contact that is driven by the drive unit 12. The connection contact 11c includes an input side connection contact 11d that can be connected to or disconnected from the input contact 11a, and an output side connection contact 11e that can be connected to or disconnected from the output contact 11b. FIG. 1A shows a configuration including a non-contact switch and a resistor R arranged in parallel between the input side connecting contact 11d and the output side connecting contact 11e. FIG. 1D shows an example in which the blocking portion 10 further includes a second connection contact 13c and four contact pairs. The connection contact 13c includes a second input connection link 13d that can be connected to or disconnected from the second input contact 13a connected to the output contact 11b, and a second output connection link 13e that can be connected to or disconnected from the second output contact 13b. With
[0022]
The relay of the present invention having the above-described configuration is to supply power to the load by turning off the contactless switch and turning on the shut-off unit after a certain period of time when supplying power to the load. When shutting off the power supply to the load, it is preferable to turn off the contactless switch and then turn off the shut-off unit.
[0023]
In this configuration, immediately after the power is turned on, the contactless switch is turned off, the current is adjusted through the resistor, and the power is supplied in a state where the current is limited. Then, after the capacitor included in the load is sufficiently charged for a certain period of time, the contactless switch is turned on to stop the current limitation, and normal power is supplied to the load. That is, the relay of the present invention can adjust the current in the same manner as a conventional relay unit when supplying power to a load by using a resistor.
[0024]
Also, in this configuration, normal power supply is performed via the contactless switch with the contactless switch turned on. Accordingly, a non-contact switch that can sufficiently withstand a normal energization current and energization voltage is used.
[0025]
On the other hand, when the supply of power is cut off, the contactless switch that does not generate an arc is first turned off. At this time, since electric power is supplied through the resistor and most of the supply voltage is applied to the resistor, the contact of the interrupting unit is in a state where there is almost no potential difference, and when turning off the interrupting unit, an arc is generated. It becomes difficult to occur or does not occur at all. The relay of the present invention can reduce or eliminate the occurrence of arc by using the resistance in this way, and can be cut off at high speed while having a simple configuration not using a gas sealing structure. In particular, when the connection part is provided in the interrupting part, there are many contact pairs, so that the voltage applied to each contact pair can be reduced, and the supply voltage applied to the interrupting part can be reduced due to failure of the non-contact switch. Even if it is not sufficient, it is possible to make it difficult to generate an arc.
[0026]
The input contact, the output contact, and the connection contact may be provided on a conductive member such as copper. In the case where the interrupting portion has only an input contact and an output contact, a conductive member provided with one contact may be disposed on a base made of an insulating material, and a driving portion may be connected to the base to form a movable contact. In the case where the blocking section further includes a connection contact, the input-side connection contact and the output-side connection contact are provided on a conductive member such as copper, and these conductive members are arranged on a base made of an insulating material and driven to this base. The parts may be connected.
[0027]
Various drive sources for the drive unit that opens and closes the contacts can be used. For example, a linear drive source such as a solenoid or a cylinder, or a rotary drive source such as a motor can be used. When using a linear drive source, the contact may be opened and closed by connecting the linear drive source to a conductive member provided with a contact or an insulating base provided with a conductive member provided with a contact. When using a rotary drive source, the contacts may be opened and closed via a conversion mechanism that converts rotational motion into reciprocating motion.
[0028]
The ON / OFF control of the non-contact switch may be performed with a control circuit. In the relay of the present invention, immediately after power is turned on, power is supplied to the load via a resistor. Therefore, the non-contact switch is turned on after a predetermined time from turning on the blocking unit. Therefore, as the control circuit of the proximity switch, it can be mentioned the resistor R ₁ to the configuration comprising a capacitor for delaying the time to turn on the proximity switch than the time to turn on the cut-off portion. Time to turn on the proximity switch, it is preferable to adjust the product of the resistance R ₁ and a capacitor. Such a control circuit is made connectable to an MPU (microcomputer) such as an ECU (Electronic Control Unit) of a control device mounted on an automobile or the like.
[0029]
The on / off control of the blocking unit may be appropriately performed using a control device equipped with an MPU (microcomputer) such as an ECU (Electric Control Unit). For example, the relay of the present invention may be attached to an existing control device in an automobile, and the drive function of the relay of the present invention may be added to the existing control device. At this time, the components of the relay itself can be further reduced, and the cost can be reduced by using an existing control device.
[0030]
In addition, the relay of the present invention may be provided with a control circuit that controls on / off of the blocking unit. Such a control circuit is connected to, for example, an MPU (microcomputer) that performs signal control, a low-voltage power supply (for example, 12 V), and a power supply circuit that serves as a power supply for the MPU and a signal to the drive unit. A configuration including a semiconductor switch and a relay for performing the above control is included. As described above, the relay of the present invention including the control circuit for controlling the on / off of the blocking unit and the on / off of the non-contact switch is preferable because it is excellent in workability for mounting on an automobile or the like.
[0031]
The control circuit for controlling the on / off of the interrupting section may be provided separately from the control circuit for turning on / off the non-contact switch. Can be made smaller, which is preferable.
[0032]
Furthermore, in the event of an accident such as a short circuit accident, a configuration may be provided in which at least the contactless switch is turned off when an excessive current flows to avoid a serious situation such as a fire due to an excessive current flowing to the load. preferable. Specifically, for example, a current sensor that measures a current supplied to a load is provided. Examples of the current sensor include a hall element and a current transformer. The information (measurement data) from the current sensor is transmitted to the MPU of the control device equipped with the relay of the present invention or the MPU of the control circuit included in the relay of the present invention, and when the current value exceeds the threshold value, the contactless switch It is preferable to configure a circuit that turns off the signal.
[0033]
Other configurations include, for example, devising a control circuit for a contactless switch. For example, it has a comparator that compares the potential of the contactless switch, more specifically, the potential difference between the source and drain and the threshold potential, and when the contactless switch potential exceeds the threshold potential, And a control circuit configured to turn off the contactless switch. The control circuit uses the fact that the current flowing through the non-contact switch and the potential difference between the source and drain are in a proportional relationship, and compares the potential difference between the source and drain with the threshold potential using a comparator. When the potential difference between the drains exceeds the threshold potential, it is determined that an overcurrent has occurred and the contactless switch is turned off. A protection circuit called a so-called latch circuit may be used. Examples of the comparator include a comparator.
[0034]
In the relay of the present invention having the above-described configuration, when an overcurrent occurs, the contactless switch is turned off so that the current flows through the resistor. Therefore, the power energy can be consumed by the resistor. Therefore, it is possible to eliminate or limit the excessive current input to the load. Thus, by eliminating or limiting an excessive current generated at the time of an accident or the like, it is easy to avoid a situation such as abnormal heating of wiring or a load.
[0035]
Further, in addition to the contactless switch, the power supply can be completely cut off by turning off the interrupting section.
[0036]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below. This embodiment is shown in the arrangement form 2 shown in Table 1.
FIG. 2 is a circuit diagram showing an outline of the DC relay of the present invention. The DC relay 1 shown in this example includes a non-contact switch 2 capable of interrupting power supply to a load, a non-contact switch 2 connected in series with the non-contact switch 2 and mechanically interruptable, and a non-contact A resistor R connected in parallel with the switch 2; Hereinafter, each configuration will be described in more detail.
[0037]
<Solid state switch>
In this example, the contactless switch 2 is an FET made of a wide gap semiconductor. In addition, this example includes a control circuit that controls ON / OFF of the contactless switch 2.
[0038]
FIG. 3A is a circuit diagram illustrating an example of a control circuit that performs ON / OFF control of a contactless switch, and FIG. 3B can delay the time for turning on the contactless switch more than the blocking unit. It is a circuit diagram. As a control circuit provided in the non-contact switch 2, for example, a configuration shown in FIG. This control circuit includes power supply terminals 2a and 2c that can be connected to a power supply circuit that supplies power to the contactless switch 2, and a capacitor C that is disposed between the power supply terminals 2a and 2c to keep the voltage of the control circuit constant. And resistors R ₁ and R ₂ for supplying an ON / OFF signal (voltage) to the non-contact switch 2 and a diode D ₁ for preventing a current from flowing from the large current system flowing through the load to the control circuit. With. Further, comprises a capacitor C _t as shown in FIG. 3 (B), the product of the resistance R ₁ and a capacitor C _t, may be adjustable circuit time to turn on the proximity switch. In the relay of the present invention, the contactless switch is turned on after a predetermined time from turning on the interrupting portion and starting to input power. At this time, if the control circuit shown in FIG. 3 (B), the time to turn on the proximity switch 2 can be delayed than the cut-off portion by the capacitor C _t and a resistor R _1.
[0039]
<Blocking part>
"contact"
FIG. 4 is a top view schematically showing the DC relay of the present invention, FIG. 5 is a front view thereof, and FIG. 6 is an exploded configuration diagram thereof. The interruption | blocking part 10 shown in this example is a structure provided with the connection contact 11c in addition to the input contact 11a and the output contact 11b. The connection contact 11c includes an input side connection contact 11d that can be connected to or disconnected from the input contact 11a, and an output side connection contact 11e that can be connected to or disconnected from the output contact 11b. Accordingly, the input contact 11a and the input side connection contact 11d form a pair of contact pairs, the output contact 11b and the output side connection contact 11e form a set of contact pairs, and a total of two contact pairs are provided. It is.
[0040]
The input contact 11a and the output contact 11b were formed on one surface of separate conductive members. The conductive member provided with the input contact 11a is provided with a terminal 10A connectable to the power source V, and the conductive member provided with the output contact 11b is provided with a terminal 10B connectable with a load.
[0041]
Similarly to the input contact 11a and the output contact 11b, the input-side connection contact 11d and the output-side connection contact 11e were also formed on one surface of separate conductive members 12f and 12g, respectively. The contactless switch 2 and the resistor R are arranged in parallel between the conductive members 12f and 12g. The conductive members 12f and 12g, the contactless switch 2 and the resistor R are disposed on a base 12c made of an insulating material.
[0042]
"Drive part"
In this example, a solenoid 12a is used as a drive source of the drive unit 12. In this example, the solenoid 12a of the drive unit 12 is connected to the base 12c on which the conductive members 12f and 12g, the contactless switch 2 and the resistor R are mounted, and the two contact pairs are opened and closed. That is, in this example, the connection contact 11c is a movable contact that can be driven by the drive unit 12, and the input contact 11a and the output contact 11b are fixed contacts. The solenoid 12a is connected to power terminals 12d and 12e for supplying power to the solenoid 12a, and appropriately turns on / off the shut-off unit 10 by supplying / stopping current. In this example, on / off control of the blocking unit 10, that is, power supply to the solenoid 12 a is performed by adding a driving function of the blocking unit 10 to an existing control device mounted on an automobile, for example.
[0043]
<Description of operation>
<Power-on operation>
In the DC relay 1 shown in this example, the operation when supplying power to the load will be described. First, the non-contact switch 2 is turned off, and the input contact 11a and the input side connection contact 11d, and the output contact 11b and the output side connection contact 11e are brought into contact with each other in order to turn on the blocking unit 10. At this time, a closed loop of power source V → input contact 11a → input side connection contact 11d (conductive member 12f) → resistance R → output side connection contact 11e (conductive member 12g) → output contact 11b → load → power source V is formed. , Electric power is supplied to the load via the resistor R. In this way, immediately after the power is turned on, the current is limited through the resistor R.
[0044]
After a certain time has elapsed, the contactless switch 2 is turned on. At this time, a closed loop of power source V → input contact 11a → input side connection contact 11d (conductive member 12f) → non-contact switch 2 → output side connection contact 11e (conductive member 12g) → output contact 11b → load → power source V Thus, electric power is supplied to the load via the contactless switch 2. In this way, the normal power supply is performed through the contactless switch and the shut-off unit. Note that when the control circuit of the contactless switch 2 is configured as shown in FIG. 3A, it may be controlled by an MPU or the like so that the contactless switch is turned on after a predetermined time has elapsed. On the other hand, in the case of the configuration shown in FIG. 3 (B), by a resistor R ₁ and a capacitor C _t, it is possible to control the timing to turn on the proximity switch. That is, the contactless switch can be controlled by the circuit configuration.
[0045]
As described above, immediately after the start of power supply, by supplying power to the load via the resistor R, the resistor R consumes power energy, so that power to the load can be limited. Therefore, the capacitor included in the load can be sufficiently charged, and a problem that a large current flows through the load immediately after the power is turned on and the load is destroyed can be effectively prevented. That is, the relay of the present invention can perform current adjustment in the same manner as a conventional relay unit.
[0046]
In addition, in the normal power supply, current flows not only through the contactless switch but also through the resistor R, but the current flows mainly through the contactless switch having a small resistance value.
[0047]
<Power cut-off operation>
Next, the operation when cutting off the power to the load will be described. At the time of power supply, the non-contact switch 2 and the cutoff unit 10 are in an on state as described above. In order to cut off the supply of power from this state, first, the contactless switch 2 is turned off. At this time, since the contactless switch 2 does not perform mechanical disconnection, no arc is generated.
[0048]
Next, the base 12c is driven by the drive unit 12 to turn off the blocking unit 10, and the input contact 11a and the input side connection contact 11d are disconnected from each other, and the output side connection contact 11e and the output contact 11b are disconnected. At this time, since the contactless switch 2 is turned off, current flows through the resistor R. That is, most of the supply voltage is applied to both ends of the resistor R, so that there is almost no potential difference at each contact pair of the interrupting unit 10. In this state, when the blocking unit 10 is turned off, an arc is hardly generated or not generated at all.
[0049]
As described above, the relay of the present invention can adjust the current, reduce the generation of arc with a simple configuration that does not use a gas sealing structure, or eliminate it at all, and enables high-speed interruption. In the relay shown in this example, even if the supply voltage is not sufficiently applied to the resistor due to failure of the contactless switch, the voltage applied to each contact pair can be increased by providing a large number of contact pairs. Since it can be made smaller, it is possible to effectively reduce the occurrence of arcs.
[0050]
[Example 1 including a control circuit for a blocking unit]
In the above example, a configuration in which a control device for controlling on / off of the blocking unit is separately provided has been described. However, the relay of the present invention may include a control circuit for controlling on / off of the blocking unit. FIG. 7 is a circuit diagram of a control circuit including a semiconductor switch.
[0051]
The control circuit shown in FIG. 7 controls the ON / OFF of the contactless switch, receives the MPU that controls the operation of the solenoid of the drive unit, the power supply circuit that drives the MPU, and the ON / OFF signal from the MPU. It comprises a semiconductor switch Q ₁ for controlling the drive current of the solenoid Te. The control circuit has a full bridge configuration including a full bridge transformer Tr and semiconductor switches Q ₁₁ , Q ₁₂ , Q ₁₃ , and Q _15, and supplies power to the control circuit of the contactless switch. In this example, the transformer Tr insulates and isolates the power source of the control circuit of the interrupting unit from the power source of the control circuit of the contactless switch. In addition, this circuit includes semiconductor switches Q ₁₄ and Q ₁₆ for transmitting a drive signal from the MPU to the semiconductor switches Q ₁₁ and Q ₁₂ , resistors R ₁₁ and R ₁₂ that provide a drive voltage for the semiconductor switch Q ₁₁ , and the semiconductor switch Q Resistors R ₁₃ and R ₁₄ that provide _twelve driving voltages, and resistors R ₁₅ and R ₁₆ that provide driving voltage for the semiconductor switch Q ₁ are provided. Semiconductor switch Q ₁ in this example, using an N-type channel field-effect transistor of the low voltage drive type (~4V).
[0052]
Such a control circuit is connected to a low voltage power source (for example, 12 V) provided separately from the high voltage power source and grounded. This is the terminal 12e is connected to the low voltage power supply to the ', the solenoid of the power supply terminal 12e of the drive unit, the terminal 12d connected to the semiconductor switches Q _1', the power supply terminal 12d of the solenoid is connected. The power supply terminal 2a of the control circuit of the proximity switch, 2c are terminals 2a through the diode _{D 11, D 12} from the full-bridge transformer Tr ', 2c' are connected to.
[0053]
With the above structure, the solenoid of the driving section, a signal from the MPU, the semiconductor switch Q ₁ is by turning on / off, the driving current is controlled.
[0054]
Thus, when the control circuit of the shut-off unit is also provided in the relay and integrated, workability at the time of mounting on an automobile or the like is good and preferable.
[0055]
[Example 2 including a control circuit for a blocking unit]
In the above example 1, it has been described the control circuit comprising a semiconductor switch Q _1, may be a circuit using a relay to perform mechanical blocking. FIG. 8 is a circuit diagram of a control circuit including a relay that performs mechanical disconnection.
[0056]
The basic configuration of the control circuit shown in FIG. 8 is the same as the circuit diagram shown in FIG. 7, and controls the ON / OFF of the contactless switch and the MPU and MPU for controlling the operation of the solenoid of the drive unit. A power supply circuit for driving. The difference is that the semiconductor switch Q ₂ that operates according to the on / off signal from the MPU and the relay RLY ₁ that is controlled by the on / off of the semiconductor switch Q ₂ to control the drive current of the solenoid can be mechanically interrupted. It is a point that has. Semiconductor switch _{Q 2} in this example, was used NPN transistor.
[0057]
The relay performing a mechanical blocking, by a control circuit for controlling the solenoid on / off of the driving unit, can be produced at low cost than the control circuit shown in FIG. 7 for controlling the semiconductor switches Q ₁ .
[0058]
[Example including a control circuit for a contactless switch and a control circuit for a breaker]
In Examples 1 and 2 above, the example in which the control circuit for the non-contact switch and the control circuit for the cutoff unit are provided separately has been described. However, the control circuit for the non-contact switch and the control circuit for the cutoff unit are integrated into a single circuit. Also good. FIG. 9 is a circuit diagram showing a control circuit in which the control circuit for the contactless switch shown in FIG. 3 (B) and the control circuit for the blocking section shown in FIGS. 7 and 8 are combined. In FIG. 9, the semiconductor switches Q ₁ and Q ₂ and the relay RLY ₁ are omitted.
[0059]
Thus, by making the control circuit of the non-contact switch and the control circuit of the shut-off unit that performs mechanical shut-off into an integrated circuit, the occupied area of the circuit can be reduced, and both control circuits can be separately provided. There is no need to manufacture, and it is excellent in workability.
[0060]
[Countermeasure 1 when overcurrent flows]
Next, a control circuit having a configuration capable of shutting off the contactless switch when a short circuit accident occurs will be described. When an accident such as a short-circuit accident occurs, a large current is generated, and an overcurrent may flow through the load. Therefore, the control circuit of this example includes a comparator and uses the comparator to turn off the contactless switch in the event of an overcurrent. FIG. 10 is a circuit diagram in which a control circuit including a comparator as a control circuit for a contactless switch and a control circuit for a blocking unit are combined.
[0061]
The basic configuration of the control circuit shown in FIG. 10 is the same as that of the control circuit combining the contactless switch control circuit shown in FIG. 3A and the blocking portion shown in FIG. The feature of this circuit is that the control circuit of the contactless switch includes a comparator COMP. Hereinafter, this point will be mainly described. In FIG. 10, the semiconductor switches Q _{1 and} Q ₂ and the relay RLY ₁ are omitted.
[0062]
In this control circuit, the comparator COMP compares the potential difference between the source and drain of the contactless switch and the threshold potential. If the potential difference between the source and drain exceeds the threshold potential, an overcurrent flows through the contactless switch. determines that turns on the semiconductor switch Q _21. Semiconductor switch _Q 20 with the ON of the semiconductor switch _{Q 21, Q 3} is turned on. By this semiconductor switch Q ₃ is turned on, a solid state switch 2 can be turned off.
[0063]
In this way, when a short-circuit accident or the like occurs, if at least the contactless switch is configured to be turned off, power energy is consumed by the resistance, so that overcurrent is hardly sent to the load. Therefore, damage to the load due to a short circuit accident or the like can be almost eliminated or prevented. In addition, if the non-contact switch is shut off and then the shut-off part is further cut off, damage due to overcurrent to the load can be prevented more reliably, and the load can be damaged or destroyed in an accident such as a short-circuit accident. Can be effectively prevented.
[0064]
In the circuit shown in FIG. 10, when the potential difference between the source and the drain becomes threshold potential than the semiconductor switch Q ₂₀ is turned on via the diode D _2, it can continue to turn the output of the comparator COMP. Further, in the circuit shown in FIG. 10, the resistor _{R 20, R 21,} resistor _{R 24} and diode _{D 2,} the driving voltage to the semiconductor switch _{Q 20} to adjust the current to the semiconductor switch _{Q 3} for applying a driving voltage to the semiconductor switch _{Q 3} Resistors R ₂₂ and R ₂₃ , resistors R ₂₅ and R ₂₆ for applying a drive voltage to the negative side of the comparator COMP, and resistors R ₂₇ and R ₂₈ for applying a drive voltage to the positive side of the comparator COMP.
[0065]
[Countermeasure 2 when overcurrent flows]
In the above countermeasure 1, it has been explained that by devising the control circuit of the contactless switch, damage to the load is prevented when an overcurrent flows. Another measure is to include a current sensor 40 that measures the current supplied to the load. FIG. 11 is a circuit diagram in which a contactless switch control circuit and a breaker control circuit are combined, and shows an example in which a current sensor is further provided. The basic configuration of this control circuit is the same as that of the control circuit combining the contactless switch control circuit shown in FIG. 3A and the blocking portion shown in FIG. The feature of this circuit is that it includes a current sensor. In FIG. 11, the semiconductor switches Q _{1 and} Q ₂ and the relay RLY ₁ are omitted.
[0066]
In this example, the current sensor 40 is a Hall element. Such a current sensor 40 is preferably connected to the MPU of the control circuit so as to be able to measure the current flowing in the vicinity of the non-contact switch as shown in FIG. 11, for example. Then, the measured current value is sent to the MPU, and when the current exceeding the threshold value is flowing in the MPU, the MPU may be configured to send a signal for turning off the contactless switch. .
[0067]
Providing a current sensor in this way can also effectively prevent problems due to overcurrent in the event of a short circuit accident or the like. Further, even when a current sensor is provided, it is easier to avoid a situation such as abnormal heating such as wiring or a load, if not only the non-contact switch but also the shut-off unit is turned off.
[0068]
Although FIG. 11 shows an example in which a current sensor is provided in a circuit in which a control circuit for a contactless switch and a control circuit for a blocking unit are integrated, only the control circuit for a contactless switch as shown in FIGS. Of course, the current sensor 40 may be provided in the case of providing the current sensor. Further, as shown in FIGS. 7 and 8, the current sensor 40 may be provided when only the control circuit for the blocking unit is provided.
[0069]
【The invention's effect】
As described above, according to the DC relay of the present invention, the number of components is small, power adjustment at the time of power-on can be performed, and the arc can be reduced or eliminated while having a simple configuration. The effects can be achieved. In particular, the relay of the present invention does not use the conventional complicated and expensive gas sealing structure, and can maintain an excellent breaking performance over a long period of time. Furthermore, since the relay of the present invention has a simple configuration, the cost can be reduced.
[Brief description of the drawings]
1A and 1B are explanatory views schematically showing a configuration of a direct current relay according to the present invention, in which FIG. 1A is an example in which a non-contact switch and a resistor are arranged between connecting contacts of a breaker, and FIG. An example in which a non-contact switch and a resistor are arranged on the high potential side of the power source and a cutoff part is arranged on the low potential side of the power source with respect to the load. FIG. (D) is an example in which a multi-contact blocking part is arranged on the higher potential side of the power supply than the load, and a non-contact switch and a resistor are arranged on the lower potential side of the power supply than the load.
FIG. 2 is a circuit diagram showing an outline of a DC relay of the present invention.
3 (A) is a circuit diagram showing an example of a control circuit for controlling the ON / OFF non-contact switch, (B) is a circuit diagram comprising a further capacitor C _t to the circuit shown in (A) It is.
FIG. 4 is a top view schematically showing the outline of the DC relay of the present invention.
FIG. 5 is a front view of the DC relay of the present invention shown in FIG.
6 is an exploded configuration diagram of the DC relay of the present invention shown in FIG. 4. FIG.
FIG. 7 is a circuit diagram showing an example of a control circuit for controlling on / off of a blocking section provided in the DC relay of the present invention, and is a control circuit including a semiconductor switch.
FIG. 8 is a circuit diagram showing an example of a control circuit that performs on / off control of a blocking unit included in the DC relay of the present invention, and is a control circuit including a relay that performs mechanical blocking.
FIG. 9 is a circuit diagram showing an example of a control circuit provided in the DC relay of the present invention, which is a control circuit that combines a control circuit for a contactless switch and a control circuit for a blocking unit.
FIG. 10 is a circuit diagram showing an example of a control circuit included in the direct current relay of the present invention, and is a control circuit capable of shutting off a contactless switch in the event of a short circuit accident or the like.
FIG. 11 is a circuit diagram showing an example of a control circuit provided in the DC relay of the present invention, which is a circuit provided with a current sensor.
FIG. 12 is a schematic circuit diagram for explaining a conventional relay unit used in HEV.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 DC relay 2 Non-contact switch 2a, 2c Power supply terminal 2a ', 2c' Terminal 10 Blocking part 10A, 10B terminal 11a Input contact 11b Output contact 11c Connection contact 11d Input side connection contact 11e Output side connection contact 12 Drive part 12a Solenoid 12c Base 12d, 12e Power terminal 12d ', 12e' terminal 12f, 12g Conductive member 13a Second input contact 13b Second output contact 13c Second connection contact 13d Second input side connection contact 13e Second output side connection contact 40 Current sensor DESCRIPTION OF SYMBOLS 100 Relay unit 101 1st relay 102 2nd relay 103 3rd relay 104 Resistance 105 Power supply 106 Service plug 107 Voltage fuse

Claims (7)

A DC relay that is connected to a power source and a load and can cut off power supply to the load,
A contactless switch capable of shutting off the supply of power;
A non-contact switch that is connected in series with the non-contact switch and that can be mechanically interrupted;
A direct current relay comprising a resistor connected in parallel with the contactless switch. When supplying power to the load, turn off the non-contact switch, turn off the non-contact switch, turn on the non-contact switch after a certain time, and supply power to the load.
2. The DC relay according to claim 1, wherein when the power supply to the load is interrupted, the interrupter is turned off after the contactless switch is turned off. 3. The direct current according to claim 1, wherein either one of the non-contact switch and the interrupting unit is arranged on the high potential side of the power supply with respect to the load, and the other is arranged on the low potential side of the power supply with respect to the load. relay. Furthermore, at least one of the 1st control circuit which controls the opening / closing operation | movement of a interruption | blocking part, and the 2nd control circuit which controls ON / OFF of a non-contact switch is provided. The described direct current relay. 5. The DC relay according to claim 4, wherein the second control circuit includes a resistor R ₁ and a capacitor for delaying a time for turning on the contactless switch from a time for turning on the blocking unit. The second control circuit includes a comparator that compares the potential of the contactless switch with the threshold potential. When the potential of the contactless switch exceeds the threshold potential, it is determined that an overcurrent has passed through the contactless switch. The direct current relay according to claim 4, wherein the direct current relay is configured to turn off a switch. Furthermore, it has a current sensor for measuring the current supplied to the load, and is configured to turn off at least the non-contact switch when an overcurrent flows. The described direct current relay.

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