JP3597629B2 - Operation signal generation circuit - Google Patents

Operation signal generation circuit Download PDF

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JP3597629B2
JP3597629B2 JP4521396A JP4521396A JP3597629B2 JP 3597629 B2 JP3597629 B2 JP 3597629B2 JP 4521396 A JP4521396 A JP 4521396A JP 4521396 A JP4521396 A JP 4521396A JP 3597629 B2 JP3597629 B2 JP 3597629B2
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signal
electromagnetic relay
circuit
transmission path
contact
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JPH09161591A (en
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坂井　　正善
弘一 蓬原
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Nippon Signal Co Ltd
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Nippon Signal Co Ltd
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Description

【０００１】
【発明の属する技術分野】
本発明は、互いに連動するメーク接点とブレーク接点を有する運転スイッチを用いて再起動防止機能を持たせて、作業者の安全を図りつつ産業機械の運転信号を発生する運転信号発生回路に関し、特に、作業者が単独或いは２人のどちらでも作業できるよう作業の運用形態に自由度を持たせた運転信号発生回路に関する。
【０００２】
【従来の技術】
例えば、工場等に設備される産業機械の運転は、作業者と機械可動部とが接触して事故が発生する危険領域に作業者がいないことを確認するだけでなく、作業者が管理上安全な領域に戻ったことを確認してはじめて機械可動部の起動を許可する再起動防止の機能を備えるべきことになっている（産業用ロボットの安全通則（ＪＩＳ Ｂ ８４３３等））。
【０００３】
この作業者が安全な領域に戻っていることの確認を行うのに、従来では互いに連動しＯＮ−ＯＦＦ動作が相補の関係であるメーク接点（作業者が操作した時にＯＮとなる）とブレーク接点（作業者が操作を解除した時にＯＮとなる）とを有する運転スイッチが用いられており、図１３に従来のこの種の運転信号発生回路を示す。
【０００４】
図１３は、運転スイッチがＯＮ故障していないこと、言い換えれば、運転スイッチがＯＦＦしていることを確認して運転信号を発生する構成の従来の運転信号発生回路である。
図１３において、運転スイッチＳＷは、互いに連動しＯＮ−ＯＦＦ動作が相補の関係にあるメーク接点ａとブレーク接点ｂとを有し、ブレーク接点ｂが、電源Ｅとアースとの間に電磁リレーＲＹ１と直列接続し、メーク接点ａが、電源Ｅとアースとの間に電磁リレーＲＹ２と直列接続する。また、前記電磁リレーＲＹ１の励磁接点ｒ１１と電磁リレーＲＹ２の励磁接点ｒ２１との並列回路を、運転スイッチＳＷのメーク接点ａと電磁リレーＲＹ２との間に直列接続している。更に、電磁リレーＲＹ２の別の励磁接点ｒ２２が、機械可動部（図示せず）の運転信号供給路１に直列接続される。電源Ｅと運転スイッチＳＷとの間には、リセットスイッチ２を設ける。
【０００５】
かかる構成では、機械可動部の起動前で作業者が運転スイッチＳＷを操作していない時には、運転スイッチＳＷのブレーク接点ｂがＯＮでメーク接点ａがＯＦＦの状態にある。この状態では、電磁リレーＲＹ１が励磁され、その励磁接点ｒ１１がＯＮとなっている。作業者が運転スイッチＳＷを押すと、ブレーク接点ｂがＯＦＦして電磁リレーＲＹ１は非励磁となるが、電磁リレーは通常５ｍｓ程度のＯＦＦ応答遅れを有しているので、この間にメーク接点ａがＯＮすれば電磁リレーＲＹ２が励磁され、その励磁接点ｒ２１，ｒ２２がＯＮし、運転信号供給路１が閉路されて機械可動部が起動する。電磁リレーＲＹ２は励磁接点ｒ２１で自己保持されるので、作業者が運転スイッチＳＷを押している間は、電磁リレーＲＹ２は励磁され続け機械可動部の運転が継続される。
【０００６】
かかる従来の運転信号発生回路では、機械可動部の起動前に運転スイッチＳＷがＯＮ故障（メーク接点ａが溶着故障）していると、ブレーク接点ｂがＯＦＦのままとなり電磁リレーＲＹ１が励磁されず、電磁リレーＲＹ２の自己保持動作ができないので機械可動部は起動しない。従って、図１３の従来回路は、運転スイッチＳＷにＯＮ故障がないことを確認して運転信号を発生させている。
【０００７】
尚、この回路では、運転スイッチＳＷを押した後で運転スイッチＳＷにＯＮ故障が生じると、運転スイッチＳＷの操作を解除しても電磁リレーＲＹ２が励磁され続けて機械可動部の運転信号が発生したままとなるので、リセットスイッチ２によって電磁リレーＲＹ２への電源供給を強制的に遮断できるようにして作業者の安全を確保している。
【０００８】
【発明が解決しようとする課題】
ところで、図１３に示す従来の運転信号発生回路は、運転スイッチは１個であり作業者が単独の場合を想定した運用形態である。作業者が複数、例えば２人の場合には、運転スイッチを２つ用意して２つの運転スイッチが操作されている時に機械可動部の運転信号が発生するようにして再起動防止機能を持たせる必要がある。しかし、この場合、もし、１人で２個の運転スイッチを同時に操作できる位置に運転スイッチを配置すると、他の１人が機械可動部と接触する危険のある危険領域に存在していても機械可動部が起動される虞れがある。このため、２人で作業する運用形態を想定した場合には、２つの運転スイッチは、１人では同時に操作できない位置に配置しなければならない。
【０００９】
このように、従来のように運転スイッチが共にＯＮしている時に運転信号が発生する方式では、運転スイッチが１個の場合には１人の作業者で機械の運転を操作し、運転スイッチが２個の場合には２人の作業者で機械の運転を操作することで安全が確保できるものであり、従来の運転信号発生回路は、その運用形態が設計段階で決まってしまい運用形態の自由度が無かった。
【００１０】
本発明は上記の事情に鑑みなされたもので、１人或いは２人のどちらでも作業者の安全を確保しつつ機械可動部の運転操作ができる、運用形態に自由度を持たせることができる運転信号発生回路を提供することを目的とする。
【００１１】
【課題を解決するための手段】
このため請求項１記載の発明では、互いに連動しＯＮ−ＯＦＦ動作が互いに相補の関係にあるメーク接点とブレーク接点を有する運転スイッチを用い、作業者が運転スイッチを操作している期間だけメーク接点がＯＮとなって機械可動部の運転信号が発生する構成の運転信号発生回路であって、前記運転スイッチを２個設け、一方の運転スイッチのメーク接点と他方の運転スイッチのブレーク接点とを直列接続して第１信号伝達経路を形成し、一方の運転スイッチのブレーク接点と他方の運転スイッチのメーク接点とを直列接続して第２信号伝達経路を形成し、作業者の前記運転スイッチ操作に基づいて前記第１及び第２信号伝達経路のいずれか一方の経路が閉路したことを検出してから所定時間内に他方の経路が閉路して信号が伝達された時に前記運転信号を発生する信号発生回路を備えて構成した。
【００１２】
かかる構成では、初めに一方の運転スイッチのメーク接点をＯＮとして対応する信号伝達経路を閉路し、次に他方の運転スイッチのメーク接点をＯＮとして対応する信号伝達経路を閉路する。信号発生回路では、先の運転スイッチ操作により信号経路が閉路されて信号が伝達されたことを検出した時に、先の運転スイッチが操作されてから所定時間内に後の運転スイッチが操作されれば運転信号を発生するが、所定時間を越えれば運転信号を発生しない。従って、運転スイッチが故障して信号伝達経路が閉路しなければ運転信号は発生せず、運転スイッチが正常の時のみ運転信号の発生が可能である。また、先の運転スイッチが操作されてから後の運転スイッチが操作されるまでの所定時間を短過ぎず或いは長過ぎないよう適切に設定すれば、１人の作業者で２つの運転スイッチを操作することが可能であると共に、２人の作業者でそれぞれの運転スイッチを操作する場合も各運転スイッチの担当作業者が運転スイッチ付近に存在しなければ運転信号を発生できず安全を確保できる。
【００１３】
請求項２記載の発明では、前記２つの運転スイッチを予め定めた順序で操作した時に前記信号発生回路から運転信号が発生する構成とした。
請求項３記載の発明では、請求項２記載の発明における信号発生回路の回路構成として、前記第１信号伝達経路に直列接続した第１電磁リレーと、前記第１信号伝達経路が開路して前記第１電磁リレーの励磁信号が遮断された時に第１電磁リレーの消磁動作を前記所定時間遅延させる第１オフ・ディレー回路と、前記第２信号伝達経路に直列接続した第２電磁リレーとを備え、前記第１電磁リレーの励磁接点と前記第２電磁リレーの第１励磁接点との並列回路を前記第２電磁リレーと直列接続し、前記第２電磁リレーの第２励磁接点を機械可動部の運転信号供給路に直列接続する構成とした。
【００１４】
請求項４記載の発明では、請求項２記載の発明における信号発生回路の別の回路構成として、前記第１信号伝達経路からの信号をトリガ信号とし前記第２信号伝達経路からの信号をホールド信号とし前記トリガ信号入力中に前記ホールド信号が入力した時出力を発生して前記トリガ信号を自己保持する第１自己保持回路と、前記第１信号伝達経路が開路した時に前記トリガ信号の停止を前記所定時間遅延させる第２オフ・ディレー回路とを備え、前記第１自己保持回路の出力に基づいて機械可動部の運転信号が発生する構成とした。
【００１５】
かかる構成によれば、請求項３記載の発明のような電磁リレーを用いた回路では、リレー接点の溶着故障を配慮すると、バックチェックを用いたセーフティーリレーの構成をとる必要があるが、本請求項の構成では、このような配慮が不要である。
請求項５記載の発明では、請求項４記載の構成において、前記第１及び第２信号伝達経路に、それぞれフォトインタラプタを介装し、各フォトインタラプタを介して前記第１自己保持回路にトリガ信号とホールド信号を入力させる構成とした。
【００１６】
請求項６記載の発明では、請求項４記載の構成において、前記第１及び第２信号伝達経路に、それぞれトランスを介装し、各トランスを介して前記第１自己保持回路にトリガ信号とホールド信号を入力させる構成とした。
請求項７記載の発明では、前記２つの運転スイッチの操作順序に関係なく、信号発生回路から運転信号が発生可能な構成とした。
【００１７】
かかる構成では、運転スイッチの操作順序を配慮する必要がなく、１人で作業する場合等の操作性が向上する。
請求項８記載の発明では、請求項７記載の発明における信号発生回路の構成として、前記第１信号伝達経路に設けられる第３及び第４電磁リレーと、前記第１信号伝達経路が開路して前記第３電磁リレーの励磁信号が遮断された時に第３電磁リレーの消磁動作を前記所定時間遅延させる第３オフ・ディレー回路と、前記第２信号伝達経路に設けられる第５及び第６電磁リレーと、前記第２信号伝達経路が開路して前記第５電磁リレーの励磁信号が遮断された時に第５電磁リレーの消磁動作を前記所定時間遅延させる第４オフ・ディレー回路とを備え、前記第３電磁リレーと第４電磁リレーとを互いに並列接続し、第５電磁リレーの励磁接点と第４電磁リレーの第１励磁接点との並列回路を、前記第３電磁リレーと並列且つ第４電磁リレーと直列に接続すると共に、前記第５電磁リレーと第６電磁リレーとを互いに並列接続し、第３電磁リレーの励磁接点と第６電磁リレーの第１励磁接点との並列回路を、前記第５電磁リレーと並列且つ第６電磁リレーと直列に接続し、前記第４電磁リレーの第２励磁接点と前記第６電磁リレーの第２励磁接点との並列回路を、機械可動部の運転信号供給路に直列接続する構成とした。
【００１８】
請求項９記載の発明では、請求項７記載の発明における信号発生回路の構成として、前記第１信号伝達経路からの信号をトリガ信号とし前記第２信号伝達経路からの信号をホールド信号とし前記トリガ信号入力中に前記ホールド信号が入力した時出力を発生して前記トリガ信号を自己保持する第２自己保持回路と、前記第２信号伝達経路からの信号をトリガ信号とし前記第１信号伝達経路からの信号をホールド信号とし前記トリガ信号入力中に前記ホールド信号が入力した時出力を発生して前記トリガ信号を自己保持する第３自己保持回路と、前記第１信号伝達経路が開路した時に前記第２自己保持回路のトリガ信号の停止を前記所定時間遅延させる第５オフ・ディレー回路と、前記第２信号伝達経路が開路した時に前記第３自己保持回路のトリガ信号の停止を前記所定時間遅延させる第６オフ・ディレー回路とを備え、前記第２及び第３自己保持回路のそれぞれの出力に基づいて機械可動部の運転信号が発生する構成とした。
【００１９】
請求項１０記載の発明では、前記２つの運転スイッチが、それぞれ第１及び第２のブレーク接点と第１及び第２のメーク接点を有し、一方の運転スイッチの第１メーク接点と他方の運転スイッチの第１ブレーク接点とを直列接続して前記第１信号伝達経路を形成し、一方の運転スイッチの第１ブレーク接点と他方の運転スイッチの第１メーク接点とを直列接続して前記第２信号伝達経路を形成し、一方の運転スイッチの第２ブレーク接点と他方の運転スイッチの第２ブレーク接点とを直列接続して第３信号伝達経路を形成する構成とし、前記信号発生回路は、前記第１信号伝達経路に設けられる第７電磁リレーと、前記第１信号伝達経路が開路して前記第７電磁リレーの励磁信号が遮断された時に第７電磁リレーの消磁動作を所定時間遅延させる第７オフ・ディレー回路と、前記第２信号伝達経路に設けられる第８電磁リレーと、前記第２信号伝達経路が開路して前記第８電磁リレーの励磁信号が遮断された時に第８電磁リレーの消磁動作を所定時間遅延させる第８オフ・ディレー回路と、前記第３信号伝達経路に設けられる第９電磁リレーと、前記第３信号伝達経路が開路して前記第９電磁リレーの励磁信号が遮断された時に第９電磁リレーの消磁動作を所定時間遅延させる第９オフ・ディレー回路と、前記一方の運転スイッチの第２メーク接点に直列接続する第１０電磁リレーと、他方の運転スイッチの第２メーク接点に直列接続する第１１電磁リレーとを備え、前記各電磁リレーを互いに並列接続し、第７電磁リレーの第１励磁接点と第１１電磁リレーの第１励磁接点との並列回路を前記第１１電磁リレーと前記他方の運転スイッチの第２メーク接点との間に直列接続し、前記第８電磁リレーの第１励磁接点と第１０電磁リレーの第１励磁接点との並列回路を第１０電磁リレーと前記一方の運転スイッチの第２メーク接点との間に直列接続し、第９電磁リレーの第１励磁接点と第７電磁リレーの第２励磁接点との並列回路を前記第７電磁リレーに直列接続し、第８電磁リレーの第２励磁接点と第９電磁リレーの第２励磁接点との並列回路を第８電磁リレーに直列接続し、前記第１０電磁リレーの第２励磁接点と前記第１１電磁リレーの第２励磁接点との並列回路を機械可動部の運転信号供給路に直列接続する構成とした。
【００２０】
請求項１１記載の発明では、前記２つの運転スイッチが、それぞれ第１及び第２のブレーク接点と第１及び第２のメーク接点を有し、一方の運転スイッチの第１メーク接点と他方の運転スイッチの第１ブレーク接点とを直列接続して前記第１信号伝達経路を形成し、一方の運転スイッチの第１ブレーク接点と他方の運転スイッチの第１メーク接点とを直列接続して前記第２信号伝達経路を形成し、一方の運転スイッチの第２ブレーク接点と他方の運転スイッチの第２ブレーク接点とを直列接続して第３信号伝達経路を形成する構成とし、前記信号発生回路は、前記第３信号伝達経路が開路した時に当該第３信号伝達経路からの信号の停止を所定時間遅延させる第１０オフ・ディレー回路と、前記第１信号伝達経路からの信号を一方の入力信号とし前記第１０オフ・ディレー回路からの出力信号を他方の入力信号とする第１論理積回路と、前記第２信号伝達経路からの信号を一方の入力信号とし前記第１０オフ・ディレー回路からの出力信号を他方の入力信号とする第２論理積回路と、前記第１論理積回路の出力信号をトリガ信号とし前記他方の運転スイッチの第２メーク接点からの信号をホールド信号とし前記トリガ信号入力中に前記ホールド信号が入力した時出力を発生して前記トリガ信号を自己保持する第４自己保持回路と、前記第２論理積回路からの信号をトリガ信号とし前記一方の運転スイッチの第２メーク接点からの信号をホールド信号とし前記トリガ信号入力中に前記ホールド信号が入力した時出力を発生して前記トリガ信号を自己保持する第５自己保持回路と、前記第１信号伝達経路が開路した時に前記第４自己保持回路のトリガ信号の停止を前記所定時間遅延させる第１１オフ・ディレー回路と、前記第２信号伝達経路が開路した時に前記第５自己保持回路のトリガ信号の停止を前記所定時間遅延させる第１２オフ・ディレー回路とを備え、前記第４及び第５自己保持回路のそれぞれの出力に基づいて機械可動部の運転信号が発生する構成とした。
【００２１】
かかる請求項１０，１１の構成によれば、一方の運転スイッチが押されている時に他方の運転スイッチが押された場合でも、運転信号を生成することが可能となる。従って、運転スイッチ操作に優先順位がない場合の２人作業時の使い勝手が向上する。
請求項１２記載の発明では、前記機械可動部と接触する可能性のある危険領域内に作業者が存在しない時に出力を発生する監視手段を設け、該監視手段から出力が発生している時のみ前記第１及び第２信号伝達経路の信号伝達を可能とする構成とした。
【００２２】
かかる構成によれば、機械可動部と接触する可能性のなる危険領域に作業者が存在する時には、決して運転信号が発生しないため、作業者の安全性をより一層高めることができる。
【００２３】
【発明の実施の形態】
以下、本発明の実施形態を図面に基づいて説明する。
図１に本発明に係る運転信号発生回路の第１の実施形態の回路図を示す。尚、従来と同一部分には同一符号を付して説明を省略する。
図１において、２つの第１及び第２運転スイッチＳＷ１，ＳＷ２は、互いに連動しＯＮ−ＯＦＦ動作が相補の関係にあるメーク接点ａ１ ，ａ２ とブレーク接点ｂ１ ，ｂ２ をそれぞれ有する。第１運転スイッチＳＷ１のメーク接点ａ１ と第２運転スイッチＳＷ２のブレーク接点ｂ２ を直列接続して第１信号伝達経路１１を形成し、第１運転スイッチＳＷ１のブレーク接点ｂ１ と第２運転スイッチＳＷ２のメーク接点ａ２ を直列接続して第２信号伝達経路１２を形成する。第１信号伝達経路１１と第２信号伝達経路１２とは電源Ｅとアースとの間で並列に接続する。また、２つの運転スイッチＳＷ１，ＳＷ２は、例えば互いに１人では同時に操作できない間隔を設けて配置する。
【００２４】
前記第１信号伝達経路１１には、第２運転スイッチＳＷ２のブレーク接点ｂ２ とアースとの間に、ダイオードＤと電磁リレーＲＹ１が順次直列に介装されている。また、抵抗ＲとコンデンサＣとからなるオフ・ディレー回路１３が、電磁リレーＲＹ１と並列に接続しており、このオフ・ディレー回路１３が、第１信号伝達経路１１が開路して電磁リレーＲＹ１の励磁信号が遮断された時に当該電磁リレーＲＹ１の消磁動作を所定時間遅延させる第１オフ・ディレー回路に対応する。第２信号伝達経路１２には、第２運転スイッチＳＷ２のメーク接点ａ２ とアースとの間に電磁リレーＲＹ２が直列に介装され、また、前記電磁リレーＲＹ１の励磁接点ｒ１１と電磁リレーＲＹ２の励磁接点ｒ２１との並列回路を、第２運転スイッチＳＷ２のメーク接点ａ２ と電磁リレーＲＹ２との間に直列接続している。更に、電磁リレーＲＹ２の別の励磁接点ｒ２２が、機械可動部（図示せず）の運転信号供給路１に直列接続される。本実施形態では、両電磁リレーＲＹ１，ＲＹ２、オフ・ディレー回路１３より信号発生回路が構成される。また、電磁リレーＲＹ１が第１電磁リレーに対応し、電磁リレーＲＹ２が第２電磁リレーに対応し、励磁接点ｒ２１，ｒ２２が、第２電磁リレーの第１及び第２励磁接点にそれぞれ対応する。
【００２５】
次に第１の実施形態の動作を、図２に示すタイムチャートを参照しながら説明する。
機械可動部の起動前で作業者が第１及び第２運転スイッチＳＷ１，ＳＷ２を操作していない状態では、両運転スイッチＳＷ１，ＳＷ２は共にブレーク接点ｂ１ ，ｂ２ がＯＮで、メーク接点ａ１ ，ａ２ が共にＯＦＦの状態にある。この状態から、まず、第１運転スイッチＳＷ１を操作してメーク接点ａ１ をＯＮにする。これにより、第１信号伝達経路１１が閉路して図２に示すように電磁リレーＲＹ１が励磁（ＯＮ）され、第２信号伝達経路１２に設けたその励磁接点ｒ１１がＯＮとなる。次に、第１運転スイッチＳＷ１の操作を解除してメーク接点ａ１ をＯＦＦすると、第１信号伝達経路１１が開路して電磁リレーＲＹ１の励磁信号が遮断されるが、オフ・ディレー回路１３の作用により、図２に示すように所定時間ＴＤ（抵抗ＲとコンデンサＣの時定数により決定される）電磁リレーＲＹ１の消磁動作が遅延される。
【００２６】
この所定時間以内に、第２運転スイッチＳＷ２を操作してメーク接点ａ２ をＯＮすれば、第１運転スイッチＳＷ１の操作解除によりブレーク接点ｂ１ がＯＮしているので第２信号伝達経路１２が閉路し、電磁リレーＲＹ１の励磁接点ｒ１１を介して電磁リレーＲＹ２が図２に示すように励磁（ＯＮ）される。これにより、その励磁接点ｒ２１，ｒ２２が共にＯＮとなり、励磁接点ｒ２２のＯＮ動作により機械可動部の運転信号供給路１が閉路して機械可動部が起動する。また、第１運転スイッチＳＷ１が操作解除されてから所定時間ＴＤ経過すると電磁リレーＲＹ１が消磁して励磁接点ｒ１１がＯＦＦとなるが、その時には励磁接点ｒ２１が既にＯＮ状態にあり電磁リレーＲＹ２が自己保持されるため、作業者の操作により第２運転スイッチＳＷ２のメーク接点ａ２ がＯＮしている間は、機械可動部への運転信号は供給され続け、作業者が第２運転スイッチＳＷ２の操作を解除したときに機械可動部への運転信号の供給が遮断されて機械可動部は停止する。
【００２７】
かかる構成において、第１運転スイッチＳＷ１の操作を解除してから所定時間ＴＤ以内に第２運転スイッチＳＷ２を操作しない場合には、電磁リレーＲＹ２が励磁されず運転信号は発生しない。また、一旦、第２運転スイッチＳＷ２の操作を解除してメーク接点ａ２ をＯＦＦした後に再度第２運転スイッチＳＷ２を操作してメーク接点ａ２ をＯＮしても、電磁リレーＲＹ１の励磁接点ｒ１１がＯＦＦしてるので電磁リレーＲＹ２は励磁されず運転信号は発生しない。この第１実施形態では、機械可動部の起動時には、予め定めた操作順序、即ち、第１運転スイッチＳＷ１を操作した後、所定時間ＴＤ内に第２運転スイッチＳＷ２を操作した時のみ運転信号が発生する。そして、前記所定時間ＴＤを適切な長さに設定することで、１人作業時の操作性と２人作業時の安全性を確保している。即ち、所定時間ＴＤが長過ぎると、第１運転スイッチＳＷ１が操作され機械可動部の起動が可能な状態にある時に第１運転スイッチを操作する作業者が機械可動部と接触する可能性のある危険領域に接近することが可能となり、このような時に第２運転スイッチＳＷ２が操作されると危険である。また、所定時間ＴＤが短過ぎると、作業者が１人の場合に第１運転スイッチＳＷ１を操作した後に直ちに第２運転スイッチＳＷ２を操作しなければならず、第１運転スイッチＳＷ１の設置場所と第２運転スイッチＳＷ２の設置場所との間の往復が大変であり、作業者の作業負担が大きく、１人作業の場合の作業性の面で問題がある。また、本実施形態によれば、第２運転スイッチＳＷ２を一旦ＯＦＦした後は再度第１運転スイッチＳＷ１をＯＮ操作しなければ運転信号が発生できない構成であり、第１運転スイッチＳＷ１の操作者が不在の時に第２運転スイッチＳＷ２を操作しても運転信号が発生せず２人作業時の安全性を確保できる。
【００２８】
図１に示す第１実施形態の回路は、両運転スイッチＳＷ１，ＳＷ２が故障しているか否かの検査機能も備えており、これについて説明する。
図３において、電源Ｅの電圧レベルをｅとし、両運転スイッチＳＷ１，ＳＷ２が共に正常とした時、第１及び第２運転スイッチＳＷ１，ＳＷ２の操作に基づくＡ点、Ｂ点の信号レベルついて見ると、第１運転スイッチＳＷ１が操作され且つ運転スイッチＳＷ２が操作されていない時（メーク接点ａ１ ＯＮ且つブレーク接点ｂ２ ＯＮ）は、抵抗ＲＡ に電流が流れてＡ点の信号レベルは＋ｅとなる。また、第１運転スイッチＳＷ１が操作されず且つ運転スイッチＳＷ２が操作された時（ブレーク接点ｂ１ ＯＮ且つメーク接点ａ２ ＯＮ）は、抵抗ＲＢ に電流が流れてＢ点の信号レベルは＋ｅとなる。尚、第１運転スイッチＳＷ１のメーク接点ａ１ とブレーク接点ｂ１ 、第２運転スイッチＳＷ２のメーク接点ａ２ とブレーク接点ｂ２ は同時にはＯＮしない。
【００２９】
表１に、第１運転スイッチＳＷ１のメーク接点ａ１ とブレーク接点ｂ１ 及び第２運転スイッチＳＷ２のメーク接点ａ２ とブレーク接点ｂ２ に故障を生じた場合のＡ点とＢ点の出力状態を示す。尚、表１中でＯＮ故障とは接点の溶着、ＯＦＦ故障とは断線を意味する。
【００３０】
【表１】

Figure 0003597629
【００３１】
表１から明らかなように、両運転スイッチＳＷ１，ＳＷ２の少なくともどちらかに故障を生じると、両運転スイッチＳＷ１，ＳＷ２を操作した時にＡ点とＢ点の少なくとも一方は出力なしとなる。
即ち、第１の実施形態のような運転スイッチＳＷ１，ＳＷの接続構成にすれば、運転スイッチの少なくとも一方が故障していると、第１信号伝達経路１１と第２信号伝達経路１２のどちらか一方は閉路せず、両運転スイッチＳＷ１，ＳＷ２が共に正常の時のみ、第１信号伝達経路１１と第２信号伝達経路１２が閉路して信号の伝達が可能となる。
【００３２】
従って、第１運転スイッチＳＷ１を操作した後、第２運転スイッチＳＷ２を操作して機械可動部の運転信号が発生するということは、両運転スイッチＳＷ１，ＳＷ２が共に正常であることを意味しており、第１の実施形態の回路は、両運転スイッチＳＷ１，ＳＷ２の故障検出機能も備えている。
また、この回路では、第２運転スイッチＳＷ２を操作した後、第２運転スイッチＳＷ２にＯＮ故障が生じると、従来回路と同様に、作業者が第２運転スイッチＳＷ２の操作を解除しても電磁リレーＲＹ２が励磁され続けて機械可動部の運転信号が発生したままとなる。この場合、従来回路では、運転スイッチとは別にリセットスイッチ２を設けて電磁リレーＲＹ２への電源供給を強制的に遮断するようにしているが、本実施例回路では、第１運転スイッチＳＷ１をリセットスイッチ２として代用することができる。即ち、本実施例回路では、両運転スイッチＳＷ１，ＳＷ２が共にＯＮしている時には第１及び第２信号伝達経路１１，１２が共に形成されず信号伝達ができない構成となっており、第１運転スイッチＳＷ１を操作してそのメーク接点ａ１ をＯＮすれば相補の関係にあるブレーク接点ｂ１ がＯＦＦして電磁リレーＲＹ２を消磁させることができ、従来回路におけるリセットスイッチ２を省略することができる。
【００３３】
次に、図４に本発明の第２実施形態の回路を示し説明する。尚、第１実施形態の回路と同一要素には同一符号を付して説明を省略する。
本実施形態は、図１の電磁リレーを用いて構成した信号発生回路を電子回路化したものである。
図４において、第１信号伝達経路１１の第２運転スイッチＳＷ２のブレーク接点ｂ２ と抵抗ＲＡ との間に、抵抗ＲとコンデンサＣとからなる図１と同一構成のオフ・ディレー回路１３の入力側が接続し、オフ・ディレー回路１３の出力側は、ダイオードＤを介して後述する自己保持回路１４のトリガ端子に接続する。このオフ・ディレー回路１３が第１信号伝達経路１１が開路した時にトリガ信号の停止を所定時間ＴＤ遅延させる第２オフ・ディレー回路に対応する。第２信号伝達経路１２の第２運転スイッチＳＷ２のメーク接点ａ２ と抵抗ＲＢ との間に、前記自己保持回路１４のホールド端子が接続する。ここで、自己保持回路１４が第１自己保持回路に対応する。
前記自己保持回路１４は、複数の抵抗とトランジスタからなるフェールセーフなＡＮＤゲートＡ１と、倍電圧整流回路ＲＥＣ１とフィードバック抵抗Ｒｆ とで構成され、トリガ信号とホールド信号が共に入力した時に発生するＡＮＤゲートＡ１の交流出力を、倍電圧整流回路ＲＥＣ１とフィードバック抵抗Ｒｆ を介してトリガ端子に帰還して出力信号を自己保持する構成である。そして、この自己保持回路１４は、電源電圧ＶＣＣより高いレベルの入力信号が入力した時のみ交流信号を発生し故障時には交流信号を発生しないフェールセーフな構成である。このようなフェールセーフな自己保持回路は、米国特許４，７５７，４１７ 号明細書、米国特許５，０２７，１１４ 号明細書、ＷＯ９４／２３３０３及びＷＯ９４／２３４９６等で従来公知である。また、フェールセーフなＡＮＤゲートは、米国特許４，６６１，８８０ 号明細書、ＷＯ９４／２３３０３及びＷＯ９４／２３４９６等で公知である。
【００３４】
自己保持回路１４の出力は、倍電圧整流回路ＲＥＣ２で整流され、この整流出力が発生した時に機械可動部に運転信号が供給される。ここで、本実施形態では、自己保持回路１４、オフ・ディレー回路１３及び倍電圧整流回路ＲＥＣ２を備えて信号発生回路が構成される。
尚、前記倍電圧整流回路ＲＥＣ１，２は、２つのコンデンサと２つのダイオードを有し、入力信号に電源電圧ＶＣＣを重畳した出力を発生する構成であり、米国特許５，０２７，１１４ 号明細書及びＷＯ９４／２３３０３等で従来公知である。
【００３５】
次に動作を説明する。
両運転スイッチＳＷ１，ＳＷ２の操作は図１と同様であり、第１運転スイッチＳＷ１を操作した後、第２運転スイッチＳＷ２を操作する。第１運転スイッチＳＷ１を操作（メーク接点ａ１ ＯＮ）すると、第１信号伝達経路１１が閉路してオフ・ディレー回路１３のコンデンサＣが充電され、自己保持回路１４のトリガ端子に電源Ｅの電圧ｅに電圧ＶＣＣが重畳された高レベルの信号が印加される。次に、第１運転スイッチＳＷ１の操作を解除した後に第２運転スイッチＳＷ２を所定時間ＴＤ以内に操作（メーク接点ａ２ ＯＮ）すると、オフ・ディレー回路１３の作用で自己保持回路１４のトリガ信号が保持されている間に、第２信号伝達経路１２から自己保持回路１４のホールド端子側に高レベルの信号が印加し、自己保持回路１４から出力が発生しトリガ端子側に帰還される。従って、自己保持回路１４は、第２信号伝達経路１２からホールド信号が入力している間は出力を自己保持して倍電圧整流回路ＲＥＣ２から整流出力が発生し続け、信号発生回路から出力ｖが発生して機械可動部に運転信号が供給される。作業者が第２運転スイッチＳＷ２の操作を解除（メーク接点ａ２ ＯＦＦ）したときに機械可動部への運転信号の供給が遮断されて機械可動部は停止する。
【００３６】
かかる構成によれば、図１の電磁リレーによる回路の場合のようにリレー接点の溶着故障に配慮する必要がない。また、信号発生回路の電子回路化により、信号発生回路の小型化ができる。
図４では、電源Ｅに直流信号源を用いたが、交流信号源を用いて図５及び図６のように構成することができる。
【００３７】
図５に示す第３実施形態の回路では、第１及び第２信号伝達経路１１，１２からのトリガ信号及びホールド信号を、それぞれフォトインタラプタ１５，１６を介して自己保持回路１４側に伝達する構成とした。
即ち、第１信号伝達経路１１の抵抗ＲＡ とアースとの間に、フォトインタラプタ１５の発光素子であるフォトダイオードＰＤ１を接続し、該フォトダイオードＰＤ１に対面させて受光素子であるフォトトランジスタＰＴ１を配置する。フォトトランジスタＰＴ１のコレクタ側には電圧ＶＣＣを印加し、エミッタ側には抵抗Ｒ１ を介してアースを接続する。エミッタ側の交流出力は、倍電圧整流回路ＲＥＣ３を介して整流されて自己保持回路１４のトリガ端子側に印加される。同様に、第２信号伝達経路１２の抵抗ＲＢ とアースとの間に、フォトインタラプタ１６のフォトダイオードＰＤ２を接続し、該フォトダイオードＰＤ２に対面させてフォトトランジスタＰＴ２を配置し、フォトトランジスタＰＴ２のコレクタ側には電圧ＶＣＣを印加し、エミッタ側には抵抗Ｒ２ を介してアースを接続する。エミッタ側の交流出力は、倍電圧整流回路ＲＥＣ４を介して整流されて自己保持回路１４のホールド端子側に印加される。信号源としてはパルス発生器１７が用いられる。尚、倍電圧整流回路ＲＥＣ３，４は、倍電圧整流回路ＲＥＣ１と同じ構成である。
【００３８】
かかる動作について説明する。
第１運転スイッチＳＷ１の操作により第１信号伝達経路１１に介装されたフォトダイオードＰＤ１が、パルス発生器１７のパルス信号周波数に応じて発光し、これをフォトトランジスタＰＴ１が受光して発生する交流出力が倍電圧整流回路ＲＥＣ３で整流され、この整流出力で第２オフ・ディレー回路の機能を有するコンデンサＣが充電され、自己保持回路１４のトリガ端子に高レベルの信号が印加される。そして、第１運転スイッチＳＷ１の操作を解除した後に所定時間ＴＤ以内に第２運転スイッチＳＷ２を操作すれば、前述と同様にして第２信号伝達経路１２側のフォトインタラプタ１６からの出力が倍電圧整流回路ＲＥＣ４を介して自己保持回路１４のホールド端子に与えられる。これにより、自己保持回路１４から出力が発生し当該自己保持回路１４が自己保持されると共に倍電圧整流回路ＲＥＣ２から整流出力が発生して機械可動部の運転信号が供給される。
【００３９】
図６に示す第４実施形態の回路では、信号源として交流電源１８を用い、第１及び第２信号伝達経路１１，１２からのトリガ信号及びホールド信号を、それぞれのトランスＴ１，Ｔ２を介して自己保持回路１４側に伝達する構成である。
かかる構成によれば、第１運転スイッチＳＷ１の操作により第１信号伝達経路１１に介装されたトランスＴ１を介して交流電源１８の交流信号に対応する交流出力が倍電圧整流回路ＲＥＣ３に入力し、整流されて自己保持回路１４のトリガ端子に高レベルの信号が印加される。第１運転スイッチＳＷ１の操作を解除した後に所定時間ＴＤ以内に第２運転スイッチＳＷ２を操作すれば、第２信号伝達経路１２側のトランスＴ２及び倍電圧整流回路ＲＥＣ４を介して自己保持回路１４にホールド端子に高レベルの信号が入力し、自己保持回路１４から出力が発生し自己保持回路１４が自己保持されると共に倍電圧整流回路ＲＥＣ２から整流出力が発生して機械可動部の運転信号が供給される。
【００４０】
次に図７に第５の実施形態の回路を示し説明する。
前述の第１〜４の実施形態の回路は、両運転スイッチＳＷ１，ＳＷ２を予め定めた順序（第１運転スイッチＳＷ１を操作した後に第２運転スイッチＳＷ２を操作）で操作しなければ機械可動部の運転信号が発生しない構成であるが、この第５実施形態は、第１運転スイッチＳＷ１，ＳＷ２のどちらを先に操作してもよく、操作順序に関係なく運転信号が発生できる構成である。尚、図１の実施形態の構成要素と同一部分には同一符号を付して説明を省略する。
【００４１】
図７において、本実施形態の回路は、図１の回路構成に、電磁リレーＲＹ３，ＲＹ４、これら電磁リレーＲＹ３，ＲＹ４の各励磁接点ｒ３１，ｒ３２，ｒ４１、ダイオードＤ′及びオフ・ディレー回路１３′を新たに付加して構成した。
即ち、図１の回路構成において、前記第１信号伝達経路１１の電磁リレーＲＹ１とダイオードＤの直列回路に対して電磁リレーＲＹ３を並列接続し、電磁リレーＲＹ３の第１励磁接点ｒ３１と電磁リレーＲＹ４の励磁接点ｒ４１との並列回路を、電磁リレーＲＹ１とダイオードＤに対して並列且つ電磁リレーＲＹ３に対して直列に接続する。また、前記第２信号伝達経路１２の電磁リレーＲＹ２と励磁接点ｒ１１、ｒ２１の並列回路の直列回路に対して電磁リレーＲＹ４と新たに設けたダイオードＤ′の直列回路を並列接続し、電磁リレーＲＹ４に対してコンデンサＣ′と抵抗Ｒ′からなるオフ・ディレー回路１３′を並列接続している。更に、電磁リレーＲＹ２，ＲＹ３の励磁接点ｒ２２，ｒ３２の並列回路が運転信号供給路１に直列に介装される。尚、オフ・ディレー回路１３，１３′は同一の構成である。
【００４２】
この回路で、電磁リレーＲＹ１が第３電磁リレーに、電磁リレーＲＹ２が第６電磁リレーに、電磁リレーＲＹ３が第４電磁リレーに、電磁リレーＲＹ４が第５電磁リレーに、それぞれ対応し、２つのオフ・ディレー回路１３，１３′がそれぞれ第３及び第４オフ・ディレー回路に対応する。また、本実施形態では、電磁リレーＲＹ１〜４、２つのオフ・ディレー回路１３，１３′を備えて信号発生回路が構成される。
【００４３】
次に動作を説明する。
第１運転スイッチＳＷ１を先に操作し所定時間ＴＤ以内に第２運転スイッチＳＷ２を操作した時の動作は、図１の第１実施形態と同様であるので説明を省略し、ここでは、第２運転スイッチＳＷ２を先に操作し、その後、第１運転スイッチＳＷ１を操作した場合についてのみ説明する。
【００４４】
先に第２運転スイッチＳＷ２を操作してメーク接点ａ２ をＯＮした場合、第２信号伝達経路１２が閉路して電磁リレーＲＹ４が励磁され、第１信号伝達経路１１側の励磁接点ｒ４１がＯＮとなる。その後、第２運転スイッチＳＷ２の操作を解除してメーク接点ａ２ をＯＦＦすると、第２信号伝達経路１１が開路して電磁リレーＲＹ４の励磁信号が遮断されるが、当該電磁リレーＲＹ４に並列接続したオフ・ディレー回路１３′の作用により、所定時間ＴＤだけ電磁リレーＲＹ４の消磁動作が遅延される。この所定時間ＴＤ以内に、第１運転スイッチＳＷ１を操作してメーク接点ａ１ をＯＮすれば、第１信号伝達経路１１が閉路し、電磁リレーＲＹ４の励磁接点ｒ４１を介して電磁リレーＲＹ３が励磁（ＯＮ）され、その励磁接点ｒ３１，ｒ３２が共にＯＮとなり、励磁接点ｒ３２のＯＮ動作により機械可動部の運転信号供給路１が閉路して機械可動部が起動する。また、第２運転スイッチＳＷ２が操作解除されてから所定時間ＴＤ経過すると電磁リレーＲＹ４が消磁して励磁接点ｒ４１がＯＦＦとなるが、励磁接点ｒ３１のＯＮ動作で電磁リレーＲＹ３が自己保持されているため、第１運転スイッチＳＷ１を作業者が操作している間、機械可動部への運転信号は供給される。
【００４５】
かかる構成によれば、第１及び第２運転スイッチＳＷ１，ＳＷ２の操作順序に関係なくどちらを先に操作しても、運転信号を発生させることができる。従って、１人で作業する場合に、機械可動部を起動させる際に第２運転スイッチＳＷ２の付近に作業者がいた時に、わざわざ第１運転スイッチＳＷ１の位置まで行くことなく、第２運転スイッチＳＷ２を操作してから第１運転スイッチＳＷ１の位置に行けばよく、運転の操作性が向上する。
【００４６】
次に図８に第６実施形態の回路を示し説明する。
この第６実施形態の回路は、図７の回路の信号発生回路を電子回路化したものであり、図５の第３実施形態を改良したものである。図５に示す実施形態と同一部分には同一符号を付して説明を省略する。
図８において、本実施形態は、図５の回路に、ＡＮＤゲートＡ１′、倍電圧整流回路ＲＥＣ１′及びフィードバック抵抗Ｒｆ′からなる自己保持回路１４′と、２つのフォトインタラプタ１５′，１６′と、３つの倍電圧整流回路ＲＥＣ２′〜４′を付加して構成される。
【００４７】
即ち、第１信号伝達経路１１側において、フォトインタラプタ１５のフォトダイオードＰＤ１と直列に、フォトインタラプタ１６′のフォトダイオードＰＤ２′を接続する。このフォトダイオードＰＤ２′と対面するフォトトランジスタＰＴ２′のエミッタと抵抗Ｒ２ ′との中間点から発生するフォトインタラプタ１６′の交流出力信号は、倍電圧整流回路ＲＥＣ４′で整流されて自己保持回路１４′のホールド端子に入力する。同様にして、第２信号伝達経路１２側において、フォトインタラプタ１６のフォトダイオードＰＤ２と直列に、フォトインタラプタ１５′のフォトダイオードＰＤ１′を接続する。このフォトダイオードＰＤ１′と対面するフォトトランジスタＰＴ１′のエミッタと抵抗Ｒ１ ′との中間点から発生するフォトインタラプタ１５′の交流出力信号は、倍電圧整流回路ＲＥＣ３′で整流されて自己保持回路１４′のトリガ端子に入力する。自己保持回路１４′は、自己保持回路１４と同一構成であり、その出力信号は、倍電圧整流回路ＲＥＣ２′で整流される。
【００４８】
この実施形態で、自己保持回路１４，１４′が、それぞれ第２自己保持回路と第３自己保持回路に対応し、各自己保持回路１４，１４′のトリガ端子側にそれぞれ接続された各コンデンサＣ，Ｃ′が第５オフ・ディレー回路と第６オフ・ディレー回路に対応する。
次に動作を説明する。
【００４９】
第１運転スイッチＳＷ１を先に操作し所定時間ＴＤ以内に第２運転スイッチＳＷ２を操作した時の動作は、図５の第３実施形態と同様であるので説明を省略し、ここでは、第２運転スイッチＳＷ２を先に操作し、その後、第１運転スイッチＳＷ１を操作した場合についてのみ説明する。
第２運転スイッチＳＷ２の操作により第２信号伝達経路１２に介装されたフォトインタラプタ１５′のフォトダイオードＰＤ１′が、パルス発生器１７のパルス信号周波数に応じて発光し、これをフォトトランジスタＰＴ１′が受光して発生する交流出力が倍電圧整流回路ＲＥＣ３′で整流され、この整流出力でコンデンサＣ′が充電され、自己保持回路１４′のトリガ端子に高レベルの信号が印加される。運転スイッチＳＷ２の操作を解除した後に所定時間ＴＤ以内に第１運転スイッチＳＷ１を操作すれば、第１信号伝達経路１１側のフォトインタラプタ１６′からの出力が倍電圧整流回路ＲＥＣ４′を介して自己保持回路１４′のホールド端子に与えられる。これにより、自己保持回路１４′から出力が発生し倍電圧整流回路ＲＥＣ２′から整流出力が発生して機械可動部の運転信号が供給される。
【００５０】
かかる構成によれば、第１運転スイッチＳＷ１を先に操作した時には、倍電圧整流回路ＲＥＣ２からの出力に基づいて運転信号が発生し、第２運転スイッチＳＷ２を先に操作した時には、倍電圧整流回路ＲＥＣ２′からの出力に基づいて運転信号が発生する。従って、どちらの運転スイッチＳＷ１，ＳＷ２を先に操作しても運転信号を発生でき、１人で作業する場合の操作性を向上できると共に、電磁リレーによる回路に比べて信号発生回路を小型化できる。
【００５１】
ところで、上述のように両運転スイッチＳＷ１，ＳＷ２の操作に優先順位を設けていない場合、２人作業時においては、１人の作業者が運転スイッチを押している時に他方の作業者がもう１つの運転スイッチを押してしまうような操作状況が考えられる。
このような操作が行われた場合、図７や図８の回路構成では運転信号が生成されない。例えば、図７の回路において、例えば運転スイッチＳＷ１がＯＮしている時に（ブレーク接点ｂ１ がＯＦＦ、メーク接点ａ１ がＯＮの時）、他方の運転スイッチＳＷ２がＯＮすると、両信号伝達経路１１，１２が共に遮断されて全ての電磁リレーＲＹ１〜ＲＹ４がＯＦＦとなって運転信号は生成されない。運転スイッチＳＷ２が押されている時に運転スイッチＳＷ１が押された場合も同様である。従って、２人作業時における使い勝手の面で充分とは言えない。
【００５２】
図９には上述の問題を解消した本発明の第７実施形態の回路構成例を示す。
図９は、図７の電磁リレーによる回路を改良したものである。
図９において、本実施形態の第１及び第２運転スイッチＳＷ１′，ＳＷ２′は、それぞれ第１及び第２のメーク接点ａ１ ，ａ１ ′とａ２ ，ａ２ ′と、第１及び第２のブレーク接点ｂ１ ，ｂ１ ′とｂ２ ，ｂ２ ′を有する。第１運転スイッチＳＷ１′の第１メーク接点ａ１ と第２運転スイッチＳＷ２′の第１ブレーク接点ｂ２ を直列接続して形成される第１信号伝達経路１１には、電磁リレーＲＹ１とオフ・ディレー回路１３の並列回路と、ダイオードＤと、前記電磁リレーＲＹ１の第２励磁接点ｒ１２と後述する電磁リレーＲＹ５の第１励磁接点ｒ５１の並列回路が直列接続される。また、第１運転スイッチＳＷ１′の第１ブレーク接点ｂ１ と第２運転スイッチＳＷ２′の第１メーク接点ａ２ を直列接続して形成される第２信号伝達経路１２には、電磁リレーＲＹ４とオフ・ディレー回路１３′の並列回路と、ダイオードＤ′と、前記電磁リレーＲＹ４の第２励磁接点ｒ４２と電磁リレーＲＹ５の第２励磁接点ｒ５２の並列回路が直列接続される。更に、第１運転スイッチＳＷ１′の第２ブレーク接点ｂ１ ′と第２運転スイッチＳＷ２′の第２ブレーク接点ｂ２ ′を直列接続して第３信号伝達経路３０を形成し、この第３信号伝達経路３０に、前記電磁リレーＲＹ５とオフ・ディレー回路１３′′の並列回路と、ダイオードＤ′′を直列接続する。前記オフ・ディレー回路１３′′は、オフ・ディレー回路１３，１３′と同様に抵抗Ｒ′′とコンデンサＣ′′で構成される。第１運転スイッチＳＷ１′の第２メーク接点ａ１ ′には、電磁リレーＲＹ３と、該電磁リレーＲＹ３の第１励磁接点ｒ３１と電磁リレーＲＹ４の第１励磁接点ｒ４１の並列回路が直列接続される。また、第２運転スイッチＳＷ２′の第２メーク接点ａ２ ′には、電磁リレーＲＹ２と、該電磁リレーＲＹ２の第１励磁接点ｒ２１と電磁リレーＲＹ１の第１励磁接点ｒ１１の並列回路が直列接続される。そして、電磁リレーＲＹ２の第２励磁接点ｒ２２と電磁リレーＲＹ３の第２励磁接点ｒ３２の並列回路が運転信号供給路１に直列接続している。
【００５３】
ここで、電磁リレーＲＹ１が第７電磁リレーに、電磁リレーＲＹ２が第１１電磁リレーに、電磁リレーＲＹ３が第１０電磁リレーに、電磁リレーＲＹ４が第８電磁リレーに、電磁リレーＲＹ５が第９電磁リレーに、それぞれ対応する。また、オフ・ディレー回路１３，１３′，１３′′がそれぞれ第７〜９オフ・ディレー回路に対応する。本実施形態では、これら電磁リレーＲＹ１〜５と、オフ・ディレー回路１３，１３′，１３′′を備えて信号発生回路が構成される。
【００５４】
次に動作を説明する。
まず、第１運転スイッチＳＷ１′がＯＮしている時に第２運転スイッチＳＷ２′をＯＮした場合について説明する。
第１及び第２運転スイッチＳＷ１′，ＳＷ２′が共にＯＦＦしている時、ブレーク接点ｂ１ ′，ｂ２ ′がＯＮ状態にあり第３信号伝達経路３０が閉路し、電磁リレーＲＹ５が励磁される。この状態で、第１運転スイッチＳＷ１′をＯＮ操作すると、電磁リレーＲＹ５は消磁するがオフ・ディレー回路１３′′の作用でその第１励磁接点ｒ５１はＯＮ状態にあるので第１信号伝達経路１１が閉路し、電磁リレーＲＹ１が励磁され、その第２励磁接点ｒ１２で自己保持される。以上の動作処理は、第１及び第２運転スイッチＳＷ１′，ＳＷ２′が共に正常にＯＦＦし、第１運転スイッチＳＷ１′が正常にＯＮしたことを確認するための処理である。
【００５５】
第１運転スイッチＳＷ１′がＯＮしいてる間に第２運転スイッチＳＷ２′が操作されて、そのメーク接点ａ２ ，ａ２ ′がＯＮしブレーク接点ｂ２ ，ｂ２ ′がＯＦＦした場合、第１信号伝達経路１１が開路して電磁リレーＲＹ１は消磁されるが、オフ・ディレー回路１３の作用によってその第１及び第２励磁接点ｒ１１，ｒ１２おＯＦＦ動作が所定時間遅れる。この間に、第２運転スイッチＳＷ２′の第２メーク接点ａ２ ′を介して電磁リレーＲＹ２が励磁され、その第１励磁接点ｒ２１で自己保持されるので、第２励磁接点ｒ２２を介して運転信号供給路１から機械可動部に運転信号が供給される。
【００５６】
逆に、第２運転スイッチＳＷ２′がＯＮしている時に第１運転スイッチＳＷ１′をＯＮした場合は、第２運転スイッチＳＷ２′のＯＮ操作で第２信号伝達経路１２の電磁リレーＲＹ４が励磁されその第２励磁接点ｒ４２で自己保持される。次に、第１運転スイッチＳＷ１′のＯＮ操作で、第１運転スイッチＳＷ１′の第２メーク接点ａ１ ′を介して電磁リレーＲＹ３が励磁され、その第１励磁接点ｒ３１で自己保持されることで、第２励磁接点ｒ３２を介して運転信号供給路１から機械可動部に運転信号が供給される。
【００５７】
かかる構成によれば、一方の運転スイッチＳＷ１′（ＳＷ２′）が押されている間に他方の運転スイッチＳＷ２′（ＳＷ１′）が押された場合でも、運転信号を生成することができる。このため、２つの運転スイッチの運転操作に優先順位がない場合の２人作業時における使い勝手が向上する。
次に図１０に本発明の第８実施形態について説明する。
【００５８】
本実施形態は、図９の信号発生回路を電子回路化したものである。
図１０において、第１信号伝達経路１１の第２運転スイッチＳＷ２′の第１ブレーク接点ｂ２ と抵抗ＲＡ との間に、第１論理積回路としてのＡＮＤゲートＡ２の一方の入力端子を接続する。また、第２信号伝達経路１２の第２運転スイッチＳＷ２′の第１メーク接点ａ２ と抵抗ＲＢ との間に、第２論理積回路としてのＡＮＤゲートＡ３の一方の入力端子を接続する。第１運転スイッチＳＷ１′の第２ブレーク接点ｂ１ ′と第２運転スイッチＳＷ２′の第２ブレーク接点ｂ２ ′を直列接続して形成した第３信号伝達経路３０には、第２運転スイッチＳＷ２′の第２ブレーク接点ｂ２ ′と抵抗Ｒ３ との間に、図４のオフ・ディレー回路１３と同様の構成のオフ・ディレー回路１３を介して前記ＡＮＤゲートＡ２，Ａ３の他方の入力端子がそれぞれ接続する。前記ＡＮＤゲートＡ２，Ａ３は、フェールセーフな構成である。
【００５９】
ＡＮＤゲートＡ２の出力は、倍電圧整流回路ＲＥＣ３とオフ・ディレー機能を有するコンデンサＣ１ を介して自己保持回路１４のトリガ端子に入力する。また、ＡＮＤゲートＡ３の出力は、同じく倍電圧整流回路ＲＥＣ３′とオフ・ディレー機能を有するコンデンサＣ１ ′を介して自己保持回路１４′のトリガ端子に入力する。前記自己保持回路１４のホールド端子は、第２運転スイッチＳＷ２′の第２メーク接点ａ２ ′と抵抗Ｒ４ との間に接続し、前記自己保持回路１４′のホールド端子は、第１運転スイッチＳＷ１′の第２メーク接点ａ１ ′と抵抗Ｒ５ との間に接続する。
【００６０】
ここで、オフ・ディレー回路１３が第１０オフ・ディレー回路に対応し、コンデンサＣ１ ，Ｃ１ ′が第１１及び第１２オフ・ディレー回路に対応する。また、自己保持回路１４，１４′が第４及び第５自己保持回路に対応する。
次に動作を説明する。
第１運転スイッチＳＷ１′がＯＮしている時に第２運転スイッチＳＷ２′をＯＮした場合について説明する。
【００６１】
第１運転スイッチＳＷ１′をＯＮすると、ＡＮＤゲートＡ２の出力が論理値１となり自己保持回路１４のトリガ端子に高レベルの入力信号が印加する。この状態で、第２運転スイッチＳＷ２′がＯＮされると、コンデンサＣ１ の遅延作用により、自己保持回路１４のホールド端子に、トリガ入力が高レベルのうちに第２運転スイッチＳＷ２′の第２メーク接点ａ２ ′を介して高レベルの信号が入力する。これにより、倍電圧整流回路ＲＥＣ２から運転信号が供給される。
【００６２】
逆に、第２運転スイッチＳＷ２′がＯＮしている時に第１運転スイッチＳＷ１′をＯＮした場合は、同様にしてＡＮＤゲートＡ３の出力に基づいて自己保持回路１４′のトリガ入力が高レベルのうちに、第１運転スイッチＳＷ１′の第２メーク接点ａ１ ′を介して自己保持回路１４′に高レベルのホールド信号が入力し、倍電圧整流回路ＲＥＣ２′から運転信号が供給される。
【００６３】
かかる構成によれば、２人作業時の使い勝手が向上すると共に、信号発生回路の電子回路化により運転信号発生回路の小型化が図れる。
次に図１１及び図１２に、第９及び第１０実施形態の回路を示し説明する。
これら実施形態の回路は、機械可動部と接触する可能性のある危険領域に作業者が存在しないことをセンサにより検出し、センサから作業者が存在しないことを示す出力信号が発生している時だけ、運転信号が発生する構成である。
【００６４】
まず、図１１に示す第９実施形態の回路について説明する。
図１１において、例えば図示しない危険領域に配置したバリアセンサ或いはマットセンサ等のセンサ出力によって励磁される電磁リレーの接点Ｒｘを、電源Ｅと第１運転スイッチＳＷ１との間に直列に介装する。前記バリアセンサ或いはマットセンサは、前記危険領域に人が存在しない時に高レベルの出力を発生するもので、センサから高レベルの出力が発生している時には、前記接点ＲｘがＯＮとなる。
【００６５】
従って、危険領域に作業者等の人が存在しない時は、センサから高レベルの出力が発生し、接点ＲｘがＯＮとなり、電源Ｅが第１運転スイッチＳＷ１に接続され、両運転スイッチＳＷ１，ＳＷ２の操作に基づいて第１信号伝達経路１１，１２を介して信号発生回路２０に信号が入力し、機械可動部の運転信号が発生する。
尚、信号発生回路２０としては、前述の第１〜６の各実施形態で示した信号発生回路のいずれも適用でき、電源に直流を使用するか交流を使用するかによって適切に選択すればよい。図９及び図１０に示す回路構成の場合も、第１運転スイッチＳＷ１′と電源Ｅとの間に電磁リレーＲｘを設けることで同様の効果を有することは言うまでもない。
【００６６】
次に、図１２に示す第１０実施形態の回路について説明する。
本実施形態の回路は、交流のセンサ出力と第１及び第２信号伝達経路１１，１２のの出力とを論理積演算する構成である。
図１２において、例えば、フォトダイオードＰＤとフォトトランジスタＰＴからなる光センサ２１を危険領域に配置する。この光センサ２１は、フォトダイオードＰＤからの光がフォトトランジスタＰＴで受光される時は交流の出力信号を発生して危険領域に人が存在しないことを示し、フォトダイオードＰＤからの光がフォトトランジスタＰＴで受光されない時は交流信号を発生せず危険領域に人が存在することを示す構成である。この光センサの交流出力信号を、倍電圧整流回路ＲＥＣ５を介してそれぞれフェールセーフなＡＮＤゲートＡ２，Ａ３の一方の入力端子に入力する。ＡＮＤゲートＡ２，Ａ３の他方の入力端子には、それぞれ第１及び第２信号伝達経路１１の信号を入力する。ＡＮＤゲートＡ２，Ａ３からの交流信号は、倍電圧整流回路ＲＥＣ６，ＲＥＣ７で整流されて信号発生回路２０に入力する。前記ＡＮＤゲートＡ２，Ａ３は、図１０と同様のものである。
【００６７】
かかる構成によれば、危険領域に人が存在せず光センサ２１からの交流信号が、各ＡＮＤゲートＡ２，Ａ３に入力していれば、第１及び第２運転スイッチＳＷ１，ＳＷ２の操作に基づいて第１及び第２信号伝達経路１１にそれぞれ信号が発生した時に各ＡＮＤゲートＡ２，Ａ３から交流信号が発生し、倍電圧整流回路ＲＥＣ６，ＲＥＣ７を介して信号発生回路２０に信号が印加されて、機械可動部の運転信号が発生することになる。
【００６８】
尚、図１２の回路構成において、マットスイッチを用いて人の存在の有無を検出する場合は、マットスイッチ上に人が存在しない時に、フォトダイオードＰＤを交流信号でスイッチングしてフォトトランジスタＰＴで受光させるようにすればよい。
従って、図１１及び図１２に示す第９及び第１０実施形態の回路構成によれば、危険領域に人が存在する時には機械可動部の運転信号を確実に停止させることができ、作業者の安全性をより一層高めることができる。
【００６９】
尚、本発明の実施形態における電磁リレーを用いた回路においては、リレーの溶着故障を考慮し、各リレーのバック接点（非励磁の時にＯＮとなる接点）を用いてバックチェック回路を構成して電磁リレーの接点溶着故障の検出を行っていることは言うまでもない。
【００７０】
【発明の効果】
以上説明したように請求項１記載の発明によれば、第１運転スイッチを操作してから第２運転スイッチを操作するまでの所定時間の設定を適切にすることで、作業者の安全を確保しつつ１人作業及び２人作業のどちらも可能であり、運用の自由度を持たせることができる。
【００７１】
請求項４記載の発明のように信号発生回路を電子回路化すれば、請求項３記載の発明のリレー回路による場合に比べて信号発生回路の小型化を図ることができる。また、リレー接点の溶着故障に対する配慮が不要である。
請求項５或いは請求項６記載の発明によれば、電源に交流信号源を用いることができる。
【００７２】
請求項７記載の発明によれば、どちらの運転スイッチを先に操作しても運転信号を発生できるので、作業者の作業効率を高めることができる。
請求項１０及び１１記載の発明によれば、一方の運転スイッチを操作している間に他方の運転スイッチを操作した場合でも運転信号が発生するので、運転スイッチの操作順序に優先順位がない場合における２人作業時の使い勝手が向上する。
【００７３】
請求項１２記載の発明によれば、機械可動部と接触する可能性のある危険領域に人が存在する時に運転信号の発生確実に防止でき、作業者の安全性をより一層高めることができる。
【図面の簡単な説明】
【図１】本発明に係る運転信号発生回路の第１実施形態を示す回路図
【図２】同上第１実施形態の動作タイムチャート
【図３】同上第１実施形態の運転スイッチの故障検出機能の説明図
【図４】本発明の運転信号発生回路の第２実施形態を示す回路図
【図５】本発明の運転信号発生回路の第３実施形態を示す回路図
【図６】本発明の運転信号発生回路の第４実施形態を示す回路図
【図７】本発明の運転信号発生回路の第５実施形態を示す回路図
【図８】本発明の運転信号発生回路の第６実施形態を示す回路図
【図９】本発明の運転信号発生回路の第７実施形態を示す回路図
【図１０】本発明の運転信号発生回路の第８実施形態を示す回路図
【図１１】本発明の運転信号発生回路の第９実施形態を示す回路図
【図１２】本発明の運転信号発生回路の第１０実施形態を示す回路図
【図１３】従来の運転信号発生回路の一例を示す回路図
【符号の説明】
１ 運転信号供給路
１１ 第１信号伝達経路
１２ 第２信号伝達経路
１３，１３′，１３′′ オフ・ディレー回路
１４，１４′ 自己保持回路
１５，１５′，１６，１６′ フォトインタラプタ
２１ 光センサ
３０ 第３信号伝達経路
ＳＷ１，ＳＷ１′ 第１運転スイッチ
ＳＷ２，ＳＷ２′ 第２運転スイッチ
ＲＹ１〜ＲＹ５ 電磁リレー
ａ１ ，ａ１ ′，ａ２ ，ａ２ ′ メーク接点
ｂ１ ，ｂ１ ′，ｂ２ ，ｂ２ ′ ブレーク接点
ｒ１１，ｒ１２，ｒ２１，ｒ２２，ｒ３１，ｒ３２，ｒ４１， ｒ４２，ｒ５１，ｒ５２ 励磁接点[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an operation signal generating circuit that generates an operation signal of an industrial machine while ensuring worker safety by providing a restart prevention function using an operation switch having a make contact and a break contact that are interlocked with each other, and in particular, The present invention also relates to an operation signal generating circuit having a degree of freedom in the operation form of a work so that a worker can work alone or with two persons.
[0002]
[Prior art]
For example, the operation of industrial machines installed in factories, etc. not only confirms that workers are not in danger areas where accidents occur due to contact between workers and machine moving parts, but also ensures that workers are safe in terms of management. It is to be provided with a function of preventing restarting that permits the starting of the machine movable part only after confirming that the robot has returned to a safe area (general rules for safety of industrial robots (JIS B 8433, etc.)).
[0003]
In order to confirm that the worker has returned to the safe area, a make contact (turned on when operated by an operator) and a break contact, which are conventionally interlocked with each other and whose ON-OFF operations are complementary, are known. (The switch is turned ON when the operator releases the operation.) FIG. 13 shows a conventional operation signal generating circuit of this type.
[0004]
FIG. 13 shows a conventional operation signal generating circuit configured to generate an operation signal after confirming that the operation switch has not failed ON, in other words, that the operation switch has been turned OFF.
In FIG. 13, the operation switch SW has a make contact a and a break contact b which are linked to each other and whose ON-OFF operations are in a complementary relationship. The break contact b is connected between the power supply E and the ground by the electromagnetic relay RY1. The make contact a is connected in series with the electromagnetic relay RY2 between the power supply E and the ground. Also, the excitation contact r of the electromagnetic relay RY1 11 And the excitation contact r of the electromagnetic relay RY2 21 Are connected in series between the make contact a of the operation switch SW and the electromagnetic relay RY2. Further, another exciting contact r of the electromagnetic relay RY2 is provided. 22 Are connected in series to the operation signal supply path 1 of the machine movable section (not shown). A reset switch 2 is provided between the power supply E and the operation switch SW.
[0005]
In this configuration, when the operator does not operate the operation switch SW before the activation of the machine movable unit, the break contact b of the operation switch SW is ON and the make contact a is OFF. In this state, the electromagnetic relay RY1 is excited and its excitation contact r 11 Is ON. When the operator presses the operation switch SW, the break contact b is turned off and the electromagnetic relay RY1 is de-energized. However, since the electromagnetic relay normally has an OFF response delay of about 5 ms, the make contact a When turned on, the electromagnetic relay RY2 is excited, and its excitation contact r 21 , R 22 Is turned on, the operation signal supply path 1 is closed, and the machine movable section is started. The electromagnetic relay RY2 has an exciting contact r 21 , The electromagnetic relay RY2 is kept energized while the operator presses the operation switch SW, and the operation of the machine movable part is continued.
[0006]
In such a conventional operation signal generating circuit, if the operation switch SW has an ON failure (make contact a has a welding failure) before the mechanical movable section is started, the break contact b remains OFF and the electromagnetic relay RY1 is not excited. Since the self-holding operation of the electromagnetic relay RY2 cannot be performed, the mechanical movable section does not start. Therefore, the conventional circuit of FIG. 13 generates an operation signal after confirming that there is no ON failure in the operation switch SW.
[0007]
In this circuit, if an ON failure occurs in the operation switch SW after the operation switch SW is pressed, the electromagnetic relay RY2 continues to be excited even if the operation of the operation switch SW is released, and an operation signal of the machine movable section is generated. As a result, the power supply to the electromagnetic relay RY2 can be forcibly shut off by the reset switch 2, thereby ensuring the safety of the worker.
[0008]
[Problems to be solved by the invention]
By the way, the conventional operation signal generation circuit shown in FIG. 13 has one operation switch, and is an operation mode assuming a case where a single worker is used. When there are a plurality of workers, for example, two workers, two operation switches are prepared, and when the two operation switches are operated, an operation signal of the machine movable portion is generated to have a restart prevention function. There is a need. However, in this case, if the operation switch is disposed at a position where one person can simultaneously operate the two operation switches, even if the other person exists in a danger area where there is a danger of contact with the movable part of the machine, There is a possibility that the movable part is activated. For this reason, when an operation mode in which two people work is assumed, the two operation switches must be arranged at positions where one person cannot operate them at the same time.
[0009]
As described above, in the conventional method in which the operation signal is generated when both the operation switches are ON, when one operation switch is provided, one operator operates the machine and the operation switch is operated. In the case of two, safety can be ensured by operating the machine by two workers. In the conventional operation signal generation circuit, the operation form is determined at the design stage, and the operation form is free. There was no degree.
[0010]
The present invention has been made in view of the above circumstances, and can be operated by one or two persons while ensuring the safety of a worker while operating a movable part of a machine. It is an object to provide a signal generation circuit.
[0011]
[Means for Solving the Problems]
For this reason, the invention according to claim 1 uses an operation switch having a make contact and a break contact that are interlocked with each other and whose ON-OFF operations are complementary to each other, and the make contact is used only while the operator is operating the operation switch. Is turned on to generate an operation signal of the machine movable part, wherein two operation switches are provided, and a make contact of one operation switch and a break contact of the other operation switch are connected in series. Connected to form a first signal transmission path, and connected in series with a break contact of one operation switch and a make contact of the other operation switch to form a second signal transmission path, which is used by an operator to operate the operation switch. The other path is closed and a signal is transmitted within a predetermined time after detecting that one of the first and second signal transmission paths is closed based on the The driving signal is configured to include a signal generation circuit for generating a.
[0012]
In such a configuration, first, the make contact of one of the operation switches is turned on to close the corresponding signal transmission path, and then the make contact of the other operation switch is turned on to close the corresponding signal transmission path. In the signal generation circuit, when it is detected that the signal path is closed by the operation of the previous operation switch and the signal is transmitted, if a subsequent operation switch is operated within a predetermined time from the operation of the previous operation switch, An operation signal is generated, but no operation signal is generated if a predetermined time is exceeded. Therefore, the operation signal is not generated unless the operation switch fails and the signal transmission path is not closed, and the operation signal can be generated only when the operation switch is normal. In addition, if the predetermined time from when the first operation switch is operated to when the next operation switch is operated is appropriately set so as not to be too short or too long, one operator can operate the two operation switches. In addition, when two operators operate the respective operation switches, an operation signal cannot be generated unless an operator in charge of each operation switch is present near the operation switch, thereby ensuring safety.
[0013]
According to a second aspect of the present invention, when the two operation switches are operated in a predetermined order, an operation signal is generated from the signal generation circuit.
According to a third aspect of the present invention, as the circuit configuration of the signal generating circuit according to the second aspect of the present invention, a first electromagnetic relay connected in series to the first signal transmission path, and the first signal transmission path being opened and the A first off-delay circuit for delaying the demagnetizing operation of the first electromagnetic relay when the excitation signal of the first electromagnetic relay is cut off, and a second electromagnetic relay connected in series to the second signal transmission path; A parallel circuit of an exciting contact of the first electromagnetic relay and a first exciting contact of the second electromagnetic relay is connected in series with the second electromagnetic relay, and a second exciting contact of the second electromagnetic relay is connected to a mechanical movable part. It was configured to be connected in series to the operation signal supply path.
[0014]
According to a fourth aspect of the present invention, as another circuit configuration of the signal generating circuit according to the second aspect of the present invention, a signal from the first signal transmission path is used as a trigger signal, and a signal from the second signal transmission path is used as a hold signal. A first self-holding circuit that generates an output when the hold signal is input during the trigger signal input and self-holds the trigger signal; and stops the trigger signal when the first signal transmission path is opened. A second off-delay circuit for delaying a predetermined time, and an operation signal of the mechanical movable section is generated based on an output of the first self-holding circuit.
[0015]
According to such a configuration, in a circuit using an electromagnetic relay as in the invention of claim 3, it is necessary to adopt a configuration of a safety relay using a back check in consideration of welding failure of a relay contact. In the configuration of the section, such consideration is not required.
According to a fifth aspect of the present invention, in the configuration of the fourth aspect, a photo interrupter is interposed in each of the first and second signal transmission paths, and a trigger signal is sent to the first self-holding circuit via each photo interrupter. And a hold signal.
[0016]
According to a sixth aspect of the present invention, in the configuration of the fourth aspect, a transformer is interposed in each of the first and second signal transmission paths, and a trigger signal and a hold are provided to the first self-holding circuit via each transformer. It was configured to input signals.
In the invention according to claim 7, the signal generating circuit can generate an operation signal regardless of the operation order of the two operation switches.
[0017]
In such a configuration, it is not necessary to consider the operation order of the operation switches, and the operability when working alone is improved.
According to an eighth aspect of the present invention, in the signal generating circuit according to the seventh aspect of the present invention, the third and fourth electromagnetic relays provided in the first signal transmission path and the first signal transmission path are opened. A third off-delay circuit for delaying the demagnetizing operation of the third electromagnetic relay by the predetermined time when the excitation signal of the third electromagnetic relay is cut off, and fifth and sixth electromagnetic relays provided in the second signal transmission path And a fourth off-delay circuit for delaying the demagnetizing operation of the fifth electromagnetic relay by the predetermined time when the second signal transmission path is opened and the excitation signal of the fifth electromagnetic relay is interrupted. A third electromagnetic relay and a fourth electromagnetic relay are connected in parallel with each other, and a parallel circuit of an exciting contact of a fifth electromagnetic relay and a first exciting contact of a fourth electromagnetic relay is connected in parallel with the third electromagnetic relay and a fourth electromagnetic relay. Directly And the fifth electromagnetic relay and the sixth electromagnetic relay are connected in parallel with each other, and a parallel circuit of an exciting contact of a third electromagnetic relay and a first exciting contact of a sixth electromagnetic relay is connected to the fifth electromagnetic relay. And a parallel circuit of the second excitation contact of the fourth electromagnetic relay and the second excitation contact of the sixth electromagnetic relay is connected in series with the operation signal supply path of the machine movable section. It was configured to connect.
[0018]
According to a ninth aspect of the present invention, in the signal generation circuit according to the seventh aspect of the present invention, the signal from the first signal transmission path is used as a trigger signal, and the signal from the second signal transmission path is used as a hold signal. A second self-holding circuit that generates an output when the hold signal is input during signal input and self-holds the trigger signal; and a signal from the second signal transmission path is used as a trigger signal to transmit the signal from the first signal transmission path. And a third self-holding circuit that generates an output when the hold signal is input during the trigger signal input and self-holds the trigger signal, and the third self-holding circuit when the first signal transmission path is opened. (2) a fifth off-delay circuit for delaying the stop of the trigger signal of the self-holding circuit by the predetermined time; and a fifth off-delay circuit for stopping the trigger signal of the third self-holding circuit when the second signal transmission path is opened. And a sixth off-delay circuit for the stop of the trigger signal is delayed the predetermined time, each of the driving signals of the mechanical movable portion based on an output of the second and third self holding circuit is configured to occur.
[0019]
In the invention according to claim 10, the two operation switches have first and second break contacts and first and second make contacts, respectively, and the first make contact of one of the operation switches and the other operation switch. The first signal transmission path is formed by connecting the first break contact of the switch in series, and the first break contact of one operation switch and the first make contact of the other operation switch are connected in series to form the second signal transmission path. Forming a third signal transmission path by forming a signal transmission path and connecting a second break contact of one operation switch and a second break contact of the other operation switch in series, wherein the signal generation circuit comprises: A seventh electromagnetic relay provided in the first signal transmission path, and a degaussing operation of the seventh electromagnetic relay delayed by a predetermined time when the first signal transmission path is opened and the excitation signal of the seventh electromagnetic relay is cut off. A seventh off-delay circuit, an eighth electromagnetic relay provided in the second signal transmission path, and an eighth electromagnetic relay when the second signal transmission path is opened and the excitation signal of the eighth electromagnetic relay is cut off. An eighth off-delay circuit for delaying the demagnetizing operation of the relay for a predetermined time, a ninth electromagnetic relay provided in the third signal transmission path, and an excitation signal of the ninth electromagnetic relay when the third signal transmission path is opened. A ninth off-delay circuit for delaying the demagnetizing operation of the ninth electromagnetic relay when the power is cut off, a tenth electromagnetic relay connected in series to the second make contact of the one operation switch, and a An eleventh electromagnetic relay connected in series to the second make contact, the electromagnetic relays being connected in parallel with each other, and a parallel arrangement of the first excitation contact of the seventh electromagnetic relay and the first excitation contact of the eleventh electromagnetic relay. A circuit is connected in series between the eleventh electromagnetic relay and a second make contact of the other operation switch, and a parallel circuit of a first excitation contact of the eighth electromagnetic relay and a first excitation contact of the tenth electromagnetic relay Are connected in series between the tenth electromagnetic relay and the second make contact of the one operation switch, and the parallel circuit of the first excitation contact of the ninth electromagnetic relay and the second excitation contact of the seventh electromagnetic relay is And a parallel circuit of a second excitation contact of the eighth electromagnetic relay and a second excitation contact of the ninth electromagnetic relay is connected in series to the eighth electromagnetic relay, and a second excitation of the tenth electromagnetic relay is connected. The parallel circuit of the contact and the second excitation contact of the eleventh electromagnetic relay is connected in series to the operation signal supply path of the movable part of the machine.
[0020]
In the invention according to claim 11, the two operation switches have first and second break contacts and first and second make contacts, respectively, and the first make contact of one operation switch and the other operation switch are provided. The first signal transmission path is formed by connecting the first break contact of the switch in series, and the first break contact of one operation switch and the first make contact of the other operation switch are connected in series to form the second signal transmission path. Forming a third signal transmission path by forming a signal transmission path and connecting a second break contact of one operation switch and a second break contact of the other operation switch in series, wherein the signal generation circuit comprises: A tenth off-delay circuit for delaying the stop of the signal from the third signal transmission path by a predetermined time when the third signal transmission path is opened; A first AND circuit using the output signal from the tenth off-delay circuit as the other input signal, and a signal from the second signal transmission path as one input signal and receiving the signal from the tenth off-delay circuit. A second AND circuit that uses an output signal as the other input signal, and a trigger signal using the output signal of the first AND circuit as a trigger signal and a signal from the second make contact of the other operation switch as a hold signal A fourth self-holding circuit for generating an output when the hold signal is input and self-holding the trigger signal; and a second make-up of the one operation switch using a signal from the second AND circuit as a trigger signal. A fifth self-holding circuit for generating an output when the hold signal is input during input of the trigger signal and holding the trigger signal by itself as a signal from a contact as a hold signal; An eleventh off-delay circuit for delaying the stop of the trigger signal of the fourth self-holding circuit by the predetermined time when one signal transmission path is opened; and a fifth self-holding circuit when the second signal transmission path is opened. A twelfth off-delay circuit for delaying the stop of the trigger signal by the predetermined time; and an operation signal for the mechanical movable section is generated based on the output of each of the fourth and fifth self-holding circuits.
[0021]
According to the configuration of the tenth and eleventh aspects, it is possible to generate an operation signal even when one operation switch is pressed while the other operation switch is pressed. Therefore, the usability at the time of two-person operation when there is no priority in the operation switch operation is improved.
According to the twelfth aspect of the present invention, there is provided a monitoring means for generating an output when no worker is present in a danger area which may come into contact with the machine movable part, and only when an output is generated from the monitoring means. The signal transmission of the first and second signal transmission paths is enabled.
[0022]
According to such a configuration, when an operator is present in a danger area where there is a possibility of contact with the machine movable part, no operation signal is generated, so that the safety of the operator can be further improved.
[0023]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a circuit diagram of a first embodiment of an operation signal generation circuit according to the present invention. The same parts as those in the related art are denoted by the same reference numerals, and description thereof is omitted.
In FIG. 1, two first and second operation switches SW1 and SW2 are linked to each other and make-up contact a whose ON-OFF operation is in a complementary relationship. 1 , A 2 And break contact b 1 , B 2 Respectively. Make contact a of the first operation switch SW1 1 And break contact b of the second operation switch SW2 2 Are connected in series to form a first signal transmission path 11, and a break contact b of the first operation switch SW1 1 And make contact a of the second operation switch SW2 2 Are connected in series to form the second signal transmission path 12. The first signal transmission path 11 and the second signal transmission path 12 are connected in parallel between the power supply E and the ground. Further, the two operation switches SW1 and SW2 are arranged at an interval that cannot be operated simultaneously by one person, for example.
[0024]
The first signal transmission path 11 includes a break contact b of the second operation switch SW2. 2 A diode D and an electromagnetic relay RY1 are sequentially interposed between the diode D and the ground. Further, an off-delay circuit 13 composed of a resistor R and a capacitor C is connected in parallel with the electromagnetic relay RY1, and this off-delay circuit 13 opens the first signal transmission path 11 to open the electromagnetic relay RY1. It corresponds to a first off-delay circuit that delays the demagnetizing operation of the electromagnetic relay RY1 for a predetermined time when the excitation signal is cut off. The second signal transmission path 12 includes a make contact a of the second operation switch SW2. 2 An electromagnetic relay RY2 is interposed in series between the electromagnetic relay RY1 and the ground. 11 And the excitation contact r of the electromagnetic relay RY2 21 Is connected to the make contact a of the second operation switch SW2. 2 And the electromagnetic relay RY2 are connected in series. Further, another exciting contact r of the electromagnetic relay RY2 is provided. 22 Are connected in series to the operation signal supply path 1 of the machine movable section (not shown). In the present embodiment, a signal generating circuit is constituted by the two electromagnetic relays RY1 and RY2 and the off-delay circuit 13. Also, the electromagnetic relay RY1 corresponds to the first electromagnetic relay, the electromagnetic relay RY2 corresponds to the second electromagnetic relay, and the excitation contact r 21 , R 22 Correspond to the first and second excitation contacts of the second electromagnetic relay, respectively.
[0025]
Next, the operation of the first embodiment will be described with reference to a time chart shown in FIG.
In a state where the operator has not operated the first and second operation switches SW1 and SW2 before the activation of the machine movable unit, both the operation switches SW1 and SW2 are both at the break contact b. 1 , B 2 Is ON, make contact a 1 , A 2 Are both OFF. From this state, first, the first operation switch SW1 is operated to make contact a. 1 To ON. Thereby, the first signal transmission path 11 is closed, and the electromagnetic relay RY1 is excited (ON) as shown in FIG. 2, and the excitation contact r provided in the second signal transmission path 12 11 Turns ON. Next, the operation of the first operation switch SW1 is released to make contact a 1 Is turned off, the first signal transmission path 11 is opened to shut off the excitation signal of the electromagnetic relay RY1, but the action of the off-delay circuit 13 causes a predetermined time TD (the resistance R and the capacitor C) as shown in FIG. (Determined by the time constant of the electromagnetic relay RY1).
[0026]
Within this predetermined time, the second operation switch SW2 is operated to make contact a 2 Is turned on, the break contact b is released by releasing the operation of the first operation switch SW1. 1 Is ON, the second signal transmission path 12 is closed, and the excitation contact r of the electromagnetic relay RY1 is turned on. 11 The electromagnetic relay RY2 is excited (ON) as shown in FIG. Thereby, the excitation contact r 21 , R 22 Are both ON, and the excitation contact r 22 Is turned on, the operation signal supply path 1 of the machine movable section is closed, and the machine movable section is activated. When a predetermined time TD elapses after the operation of the first operation switch SW1 is released, the electromagnetic relay RY1 is demagnetized and the excitation contact r 11 Is turned off, at which time the excitation contact r 21 Is already in the ON state and the electromagnetic relay RY2 is self-held, so that the operator operates the make contact a of the second operation switch SW2. 2 While the switch is ON, the operation signal to the machine movable section is continuously supplied. When the operator releases the operation of the second operation switch SW2, the supply of the operation signal to the machine movable section is cut off and the machine is moved. Department stops.
[0027]
In this configuration, if the second operation switch SW2 is not operated within a predetermined time TD after the operation of the first operation switch SW1 is released, the electromagnetic relay RY2 is not excited and no operation signal is generated. Also, once the operation of the second operation switch SW2 is released and the make contact a 2 Is turned off, the second operation switch SW2 is operated again to make contact a. 2 Is turned on, the excitation contact r of the electromagnetic relay RY1 11 Is OFF, the electromagnetic relay RY2 is not excited, and no operation signal is generated. In the first embodiment, at the time of activation of the mechanical movable unit, the operation signal is generated only when the second operation switch SW2 is operated within a predetermined time TD after operating the first operation switch SW1 in a predetermined operation order. appear. By setting the predetermined time TD to an appropriate length, operability during single-person operation and safety during two-person operation are ensured. That is, if the predetermined time TD is too long, there is a possibility that the operator operating the first operation switch contacts the machine movable unit when the first operation switch SW1 is operated and the machine movable unit can be activated. It is possible to approach the danger area, and it is dangerous if the second operation switch SW2 is operated in such a case. If the predetermined time TD is too short, the second operation switch SW2 must be operated immediately after operating the first operation switch SW1 when only one worker is operated, and the location of the first operation switch SW1 and The reciprocation with the installation location of the second operation switch SW2 is difficult, and the work load on the operator is large, and there is a problem in terms of workability in the case of single-person work. Further, according to the present embodiment, after the second operation switch SW2 is once turned off, the operation signal cannot be generated unless the first operation switch SW1 is turned on again. Even if the second operation switch SW2 is operated when the user is absent, no operation signal is generated and safety during two-person operation can be ensured.
[0028]
The circuit of the first embodiment shown in FIG. 1 also has a function of checking whether or not both of the operation switches SW1 and SW2 have failed. This will be described.
In FIG. 3, when the voltage level of the power supply E is e and both the operation switches SW1 and SW2 are normal, the signal levels at the points A and B based on the operation of the first and second operation switches SW1 and SW2 are examined. And when the first operation switch SW1 is operated and the operation switch SW2 is not operated (make contact a 1 ON and break contact b 2 ON) is the resistance R A And the signal level at point A becomes + e. When the first operation switch SW1 is not operated and the operation switch SW2 is operated (break contact b 1 ON and make contact a 2 ON) is the resistance R B And the signal level at point B becomes + e. The make contact a of the first operation switch SW1 1 And break contact b 1 , Make contact a of the second operation switch SW2 2 And break contact b 2 Do not turn on at the same time.
[0029]
Table 1 shows the make contact a of the first operation switch SW1. 1 And break contact b 1 And make contact a of the second operation switch SW2 2 And break contact b 2 3 shows output states at points A and B when a failure occurs. In Table 1, ON failure means contact welding and OFF failure means disconnection.
[0030]
[Table 1]
Figure 0003597629
[0031]
As is evident from Table 1, when at least one of the two operation switches SW1 and SW2 fails, at least one of the points A and B becomes no output when both the operation switches SW1 and SW2 are operated.
That is, according to the connection configuration of the operation switches SW1 and SW as in the first embodiment, if at least one of the operation switches has failed, one of the first signal transmission path 11 and the second signal transmission path 12 can be used. One is not closed, and only when both the operation switches SW1 and SW2 are normal, the first signal transmission path 11 and the second signal transmission path 12 are closed to enable signal transmission.
[0032]
Therefore, operating the first operation switch SW1 and then operating the second operation switch SW2 to generate an operation signal of the machine movable unit means that both operation switches SW1 and SW2 are normal. The circuit of the first embodiment also has a function of detecting a failure of both operation switches SW1 and SW2.
Further, in this circuit, if an ON failure occurs in the second operation switch SW2 after operating the second operation switch SW2, as in the conventional circuit, even if the operator cancels the operation of the second operation switch SW2, the electromagnetic operation is stopped. The relay RY2 is kept energized, and the operation signal of the machine movable part remains generated. In this case, in the conventional circuit, a reset switch 2 is provided separately from the operation switch to forcibly cut off the power supply to the electromagnetic relay RY2. However, in the circuit of this embodiment, the first operation switch SW1 is reset. The switch 2 can be substituted. That is, in the circuit of the present embodiment, when both the operation switches SW1 and SW2 are both ON, the first and second signal transmission paths 11 and 12 are not formed together and the signal cannot be transmitted. By operating the switch SW1, the make contact a 1 Is turned on, the break contact b in a complementary relationship 1 Is turned off to demagnetize the electromagnetic relay RY2, and the reset switch 2 in the conventional circuit can be omitted.
[0033]
Next, a circuit according to a second embodiment of the present invention will be described with reference to FIG. Note that the same elements as those of the circuit of the first embodiment are denoted by the same reference numerals, and description thereof is omitted.
In this embodiment, a signal generation circuit configured using the electromagnetic relay of FIG. 1 is formed into an electronic circuit.
In FIG. 4, the break contact b of the second operation switch SW2 of the first signal transmission path 11 is shown. 2 And resistance R A The input side of an off-delay circuit 13 composed of a resistor R and a capacitor C, which has the same configuration as that of FIG. 1, is connected to the output side of the off-delay circuit 13 via a diode D. 14 trigger terminals. The off-delay circuit 13 corresponds to a second off-delay circuit that delays the stop of the trigger signal by a predetermined time TD when the first signal transmission path 11 is opened. Make contact a of the second operation switch SW2 of the second signal transmission path 12 2 And resistance R B , The hold terminal of the self-holding circuit 14 is connected. Here, the self-holding circuit 14 corresponds to a first self-holding circuit.
The self-holding circuit 14 includes a fail-safe AND gate A1 including a plurality of resistors and transistors, a voltage doubler rectifier REC1, and a feedback resistor R. f The AC output of the AND gate A1 generated when both the trigger signal and the hold signal are input is supplied to the voltage doubler rectifier circuit REC1 and the feedback resistor R. f , And is self-holding the output signal by returning to the trigger terminal. The self-holding circuit 14 is connected to the power supply voltage V CC This is a fail-safe configuration in which an AC signal is generated only when an input signal of a higher level is input, and no AC signal is generated when a failure occurs. Such a fail-safe self-holding circuit is conventionally known in U.S. Pat. No. 4,757,417, U.S. Pat. No. 5,027,114, WO94 / 23303, WO94 / 23496, and the like. Further, fail-safe AND gates are known from U.S. Pat. No. 4,661,880, WO94 / 23303 and WO94 / 23496.
[0034]
The output of the self-holding circuit 14 is rectified by the voltage doubler rectifier circuit REC2, and when this rectified output is generated, an operation signal is supplied to the machine movable unit. Here, in the present embodiment, a signal generation circuit is configured to include the self-holding circuit 14, the off-delay circuit 13, and the voltage doubler rectifier circuit REC2.
The voltage doubler rectifier circuits REC1 and REC2 have two capacitors and two diodes, and the power supply voltage V CC Is generated, and is conventionally known in US Pat. No. 5,027,114, WO94 / 23303, and the like.
[0035]
Next, the operation will be described.
The operation of both operation switches SW1 and SW2 is the same as in FIG. 1. After operating the first operation switch SW1, the second operation switch SW2 is operated. Operate the first operation switch SW1 (make contact a 1 ON), the first signal transmission path 11 is closed, the capacitor C of the off-delay circuit 13 is charged, and the voltage V of the power supply E is applied to the trigger terminal of the self-holding circuit 14. CC Is superimposed and a high level signal is applied. Next, after the operation of the first operation switch SW1 is released, the second operation switch SW2 is operated within a predetermined time TD (make contact a 2 ON), a high-level signal is applied from the second signal transmission path 12 to the hold terminal side of the self-holding circuit 14 while the trigger signal of the self-holding circuit 14 is held by the action of the off-delay circuit 13. Then, an output is generated from the self-holding circuit 14 and is fed back to the trigger terminal side. Therefore, while the hold signal is being input from the second signal transmission path 12, the self-holding circuit 14 self-holds the output and continues to generate a rectified output from the voltage doubler rectifier circuit REC2, and the output v is output from the signal generating circuit. Then, an operation signal is supplied to the movable part of the machine. The operator releases the operation of the second operation switch SW2 (make contact a 2 When the switch is turned off, the supply of the operation signal to the machine movable unit is interrupted, and the machine movable unit stops.
[0036]
According to such a configuration, it is not necessary to consider the welding failure of the relay contacts as in the case of the circuit using the electromagnetic relay of FIG. Further, by making the signal generation circuit an electronic circuit, the size of the signal generation circuit can be reduced.
In FIG. 4, a DC signal source is used as the power supply E, but the power supply E can be configured as shown in FIGS. 5 and 6 using an AC signal source.
[0037]
In the circuit according to the third embodiment shown in FIG. 5, the trigger signal and the hold signal from the first and second signal transmission paths 11 and 12 are transmitted to the self-holding circuit 14 via the photo interrupters 15 and 16, respectively. And
That is, the resistance R of the first signal transmission path 11 A A photodiode PD1 which is a light emitting element of the photointerrupter 15 is connected between the ground and the ground, and a phototransistor PT1 which is a light receiving element is arranged so as to face the photodiode PD1. The voltage V is applied to the collector of the phototransistor PT1. CC And a resistor R is connected to the emitter side. 1 Connect the ground through. The AC output on the emitter side is rectified through the voltage doubler rectifier circuit REC3 and applied to the trigger terminal side of the self-holding circuit 14. Similarly, the resistance R of the second signal transmission path 12 B The photodiode PD2 of the photointerrupter 16 is connected between the phototransistor 16 and the ground, and the phototransistor PT2 is disposed so as to face the photodiode PD2. CC And a resistor R is connected to the emitter side. 2 Connect the ground through. The AC output on the emitter side is rectified via the voltage doubler rectifier circuit REC4 and applied to the hold terminal side of the self-holding circuit 14. The pulse generator 17 is used as a signal source. Note that the voltage doubler rectifier circuits REC3 and REC4 have the same configuration as the voltage doubler rectifier circuit REC1.
[0038]
The operation will be described.
By operating the first operation switch SW1, the photodiode PD1 interposed in the first signal transmission path 11 emits light in accordance with the pulse signal frequency of the pulse generator 17, and the phototransistor PT1 receives light to generate an alternating current. The output is rectified by the voltage doubler rectifier circuit REC 3, the capacitor C having the function of the second off-delay circuit is charged with the rectified output, and a high-level signal is applied to the trigger terminal of the self-holding circuit 14. If the second operation switch SW2 is operated within a predetermined time TD after the operation of the first operation switch SW1 is released, the output from the photo-interrupter 16 on the second signal transmission path 12 will be doubled in the same manner as described above. The signal is supplied to the hold terminal of the self-holding circuit 14 via the rectifier circuit REC4. As a result, an output is generated from the self-holding circuit 14, the self-holding circuit 14 is self-held, and a rectified output is generated from the voltage doubler rectifier circuit REC2 to supply an operation signal of the machine movable unit.
[0039]
In the circuit of the fourth embodiment shown in FIG. 6, an AC power supply 18 is used as a signal source, and a trigger signal and a hold signal from the first and second signal transmission paths 11 and 12 are transmitted via respective transformers T1 and T2. The transmission is to the self-holding circuit 14 side.
According to this configuration, an AC output corresponding to the AC signal of the AC power supply 18 is input to the voltage doubler rectifier circuit REC3 through the transformer T1 provided in the first signal transmission path 11 by operating the first operation switch SW1. The signal is rectified and a high-level signal is applied to the trigger terminal of the self-holding circuit 14. If the second operation switch SW2 is operated within a predetermined time TD after the operation of the first operation switch SW1 is released, the self-holding circuit 14 is connected to the transformer T2 on the second signal transmission path 12 side and the voltage doubler rectifier circuit REC4. A high-level signal is input to the hold terminal, an output is generated from the self-holding circuit 14, the self-holding circuit 14 is self-held, and a rectified output is generated from the voltage doubler rectifier REC2 to supply an operation signal for the machine movable unit. Is done.
[0040]
Next, FIG. 7 shows a circuit according to a fifth embodiment and will be described.
The circuits of the above-described first to fourth embodiments require that the two operation switches SW1 and SW2 be operated in a predetermined order (the second operation switch SW2 is operated after the first operation switch SW1 is operated). The fifth embodiment has a configuration in which either of the first operation switches SW1 and SW2 may be operated first, and the operation signal can be generated regardless of the operation order. The same parts as those in the embodiment of FIG. 1 are denoted by the same reference numerals, and description thereof is omitted.
[0041]
7, the circuit of the present embodiment is different from the circuit configuration of FIG. 1 in that the electromagnetic relays RY3 and RY4 and the excitation contacts r of the electromagnetic relays RY3 and RY4 31 , R 32 , R 41 , A diode D 'and an off-delay circuit 13'.
That is, in the circuit configuration of FIG. 1, the electromagnetic relay RY3 is connected in parallel to the series circuit of the electromagnetic relay RY1 and the diode D of the first signal transmission path 11, and the first exciting contact r of the electromagnetic relay RY3 is formed. 31 And the exciting contact r of the electromagnetic relay RY4 41 Are connected in parallel with the electromagnetic relay RY1 and the diode D and in series with the electromagnetic relay RY3. Further, the electromagnetic relay RY2 of the second signal transmission path 12 and the excitation contact r 11 , R 21 Is connected in parallel with a series circuit of an electromagnetic relay RY4 and a newly provided diode D ', and an off-delay circuit 13' including a capacitor C 'and a resistor R' is connected to the electromagnetic relay RY4. They are connected in parallel. Further, the excitation contacts r of the electromagnetic relays RY2 and RY3 22 , R 32 Are connected in series in the operation signal supply path 1. The off-delay circuits 13, 13 'have the same configuration.
[0042]
In this circuit, the electromagnetic relay RY1 corresponds to the third electromagnetic relay, the electromagnetic relay RY2 corresponds to the sixth electromagnetic relay, the electromagnetic relay RY3 corresponds to the fourth electromagnetic relay, and the electromagnetic relay RY4 corresponds to the fifth electromagnetic relay. The off-delay circuits 13, 13 'correspond to third and fourth off-delay circuits, respectively. Further, in the present embodiment, a signal generation circuit is provided with the electromagnetic relays RY1 to RY4 and two off-delay circuits 13 and 13 '.
[0043]
Next, the operation will be described.
The operation when the first operation switch SW1 is operated first and the second operation switch SW2 is operated within the predetermined time TD is the same as that of the first embodiment of FIG. Only the case where the operation switch SW2 is operated first and then the first operation switch SW1 is operated will be described.
[0044]
First, the second operation switch SW2 is operated to make contact a. 2 Is turned on, the second signal transmission path 12 is closed, the electromagnetic relay RY4 is excited, and the excitation contact r on the first signal transmission path 11 side is turned on. 41 Turns ON. Thereafter, the operation of the second operation switch SW2 is released to make contact a 2 Is turned off, the second signal transmission path 11 is opened to shut off the excitation signal of the electromagnetic relay RY4. However, the electromagnetic relay RY4 is connected in parallel with the off-delay circuit 13 'to operate the electromagnetic relay RY4 for a predetermined time TD. The degaussing operation of RY4 is delayed. Within this predetermined time TD, the first operation switch SW1 is operated to make contact a 1 Is turned on, the first signal transmission path 11 is closed, and the excitation contact r of the electromagnetic relay RY4 is closed. 41 The electromagnetic relay RY3 is excited (ON) via the 31 , R 32 Are both ON, and the excitation contact r 32 Is turned on, the operation signal supply path 1 of the machine movable section is closed, and the machine movable section is activated. When a predetermined time TD elapses after the operation of the second operation switch SW2 is released, the electromagnetic relay RY4 is demagnetized and the excitation contact r 41 Turns off, but the excitation contact r 31 Because the electromagnetic relay RY3 is self-held by the ON operation of, an operation signal is supplied to the machine movable section while the operator operates the first operation switch SW1.
[0045]
According to such a configuration, an operation signal can be generated regardless of which of the first and second operation switches SW1 and SW2 is operated. Therefore, when working alone, when an operator is near the second operation switch SW2 when activating the machine movable unit, the second operation switch SW2 does not need to go to the position of the first operation switch SW1. It is only necessary to go to the position of the first operation switch SW1 after operating, and the operability of driving is improved.
[0046]
Next, FIG. 8 shows a circuit according to the sixth embodiment and will be described.
The circuit of the sixth embodiment is an electronic circuit of the signal generation circuit of the circuit of FIG. 7, and is an improvement of the third embodiment of FIG. The same parts as those of the embodiment shown in FIG.
In FIG. 8, the present embodiment is different from the circuit of FIG. 5 in that a self-holding circuit 14 'including an AND gate A1', a voltage doubler rectifier REC1 'and a feedback resistor Rf', two photo-interrupters 15 'and 16'. And three additional voltage rectifier circuits REC2 'to REC4'.
[0047]
That is, the photodiode PD2 'of the photointerrupter 16' is connected in series with the photodiode PD1 of the photointerrupter 15 on the first signal transmission path 11 side. The emitter of the phototransistor PT2 'facing the photodiode PD2' and the resistor R 2 The AC output signal of the photo-interrupter 16 'generated from the intermediate point between the rectifying circuit rectified by the voltage doubler rectifier circuit REC4' is input to the hold terminal of the self-holding circuit 14 '. Similarly, on the second signal transmission path 12 side, the photodiode PD1 'of the photointerrupter 15' is connected in series with the photodiode PD2 of the photointerrupter 16. The emitter of the phototransistor PT1 'facing the photodiode PD1' and the resistor R 1 The AC output signal of the photo-interrupter 15 'generated from the midpoint between the signal and the signal rectified by the voltage doubler rectifier REC3' is input to the trigger terminal of the self-holding circuit 14 '. The self-holding circuit 14 'has the same configuration as the self-holding circuit 14, and its output signal is rectified by the voltage doubler rectifier REC2'.
[0048]
In this embodiment, the self-holding circuits 14 and 14 'correspond to the second self-holding circuit and the third self-holding circuit, respectively, and each capacitor C connected to the trigger terminal side of each self-holding circuit 14 and 14', respectively. , C 'correspond to the fifth off-delay circuit and the sixth off-delay circuit.
Next, the operation will be described.
[0049]
The operation when the first operation switch SW1 is operated first and the second operation switch SW2 is operated within the predetermined time TD is the same as that of the third embodiment in FIG. Only the case where the operation switch SW2 is operated first and then the first operation switch SW1 is operated will be described.
By the operation of the second operation switch SW2, the photodiode PD1 'of the photointerrupter 15' interposed in the second signal transmission path 12 emits light in accordance with the pulse signal frequency of the pulse generator 17, and emits light by the phototransistor PT1 '. The AC output generated by receiving light is rectified by the voltage doubler rectifier circuit REC3 ', the capacitor C' is charged with this rectified output, and a high-level signal is applied to the trigger terminal of the self-holding circuit 14 '. If the first operation switch SW1 is operated within a predetermined time TD after the operation of the operation switch SW2 is released, the output from the photo interrupter 16 'on the first signal transmission path 11 side becomes self-controlled via the voltage doubler rectifier circuit REC4'. It is provided to the hold terminal of the holding circuit 14 '. As a result, an output is generated from the self-holding circuit 14 'and a rectified output is generated from the voltage doubler rectifier circuit REC2', and an operation signal of the machine movable section is supplied.
[0050]
According to this configuration, when the first operation switch SW1 is operated first, an operation signal is generated based on the output from the voltage doubler rectifier circuit REC2, and when the second operation switch SW2 is operated first, the voltage doubler rectification is performed. An operation signal is generated based on the output from the circuit REC2 '. Therefore, the operation signal can be generated by operating either of the operation switches SW1 and SW2 first, the operability in the case of working alone can be improved, and the signal generation circuit can be downsized as compared with a circuit using an electromagnetic relay. .
[0051]
By the way, in the case where no priority is given to the operation of both operation switches SW1 and SW2 as described above, in the case of a two-person operation, when one operator is pressing the operation switch, the other operator is switched to another one. An operation situation in which the operation switch is pressed may be considered.
When such an operation is performed, no operation signal is generated in the circuit configurations of FIGS. 7 and 8. For example, in the circuit of FIG. 7, for example, when the operation switch SW1 is ON (break contact b 1 Is OFF, make contact a 1 When the other operation switch SW2 is turned on, both the signal transmission paths 11 and 12 are shut off, and all the electromagnetic relays RY1 to RY4 are turned off and no operation signal is generated. The same applies when the operation switch SW1 is pressed while the operation switch SW2 is pressed. Therefore, it cannot be said that the usability at the time of two-person operation is sufficient.
[0052]
FIG. 9 shows a circuit configuration example of the seventh embodiment of the present invention in which the above-mentioned problem is solved.
FIG. 9 is an improved circuit of the electromagnetic relay of FIG.
In FIG. 9, the first and second operation switches SW1 'and SW2' of the present embodiment are respectively provided with first and second make contacts a. 1 , A 1 'And a 2 , A 2 'And the first and second break contacts b 1 , B 1 'And b 2 , B 2 '. First make contact a of first operation switch SW1 ' 1 And the first break contact b of the second operation switch SW2 ' 2 Are connected in series, a first signal transmission path 11 includes a parallel circuit of an electromagnetic relay RY1 and an off-delay circuit 13, a diode D, and a second excitation contact r of the electromagnetic relay RY1. 12 And a first excitation contact r of an electromagnetic relay RY5 described later. 51 Are connected in series. Also, the first break contact b of the first operation switch SW1 ' 1 And the first make contact a of the second operation switch SW2 ' 2 Are connected in series, a parallel circuit of an electromagnetic relay RY4 and an off-delay circuit 13 ', a diode D', and a second exciting contact r of the electromagnetic relay RY4 are provided. 42 And the second excitation contact r of the electromagnetic relay RY5 52 Are connected in series. Further, the second break contact b of the first operation switch SW1 ' 1 'And the second break contact b of the second operation switch SW2' 2 Are connected in series to form a third signal transmission path 30. In this third signal transmission path 30, a parallel circuit of the electromagnetic relay RY5 and the off-delay circuit 13 '' and a diode D '' are connected in series. . The off-delay circuit 13 "is composed of a resistor R" and a capacitor C ", like the off-delay circuits 13 and 13 '. Second make contact a of first operation switch SW1 ' 1 'Has an electromagnetic relay RY3 and a first excitation contact r of the electromagnetic relay RY3. 31 And the first excitation contact r of the electromagnetic relay RY4 41 Are connected in series. Also, the second make contact a of the second operation switch SW2 ' 2 'Has an electromagnetic relay RY2 and a first excitation contact r of the electromagnetic relay RY2. 21 And the first excitation contact r of the electromagnetic relay RY1 11 Are connected in series. Then, the second excitation contact r of the electromagnetic relay RY2 22 And the second excitation contact r of the electromagnetic relay RY3 32 Are connected in series to the operation signal supply path 1.
[0053]
Here, the electromagnetic relay RY1 is the seventh electromagnetic relay, the electromagnetic relay RY2 is the eleventh electromagnetic relay, the electromagnetic relay RY3 is the tenth electromagnetic relay, the electromagnetic relay RY4 is the eighth electromagnetic relay, and the electromagnetic relay RY5 is the ninth electromagnetic relay. Each corresponds to a relay. The off-delay circuits 13, 13 ', and 13 "correspond to the seventh to ninth off-delay circuits, respectively. In the present embodiment, a signal generation circuit is configured by including these electromagnetic relays RY1 to RY5 and the off-delay circuits 13, 13 ', 13''.
[0054]
Next, the operation will be described.
First, a case where the second operation switch SW2 'is turned on while the first operation switch SW1' is turned on will be described.
When both the first and second operation switches SW1 'and SW2' are OFF, the break contact b 1 ', B 2 'Is in the ON state, the third signal transmission path 30 is closed, and the electromagnetic relay RY5 is excited. When the first operation switch SW1 'is turned on in this state, the electromagnetic relay RY5 is demagnetized, but the first excitation contact r is acted on by the action of the off-delay circuit 13 ". 51 Is in the ON state, the first signal transmission path 11 is closed, the electromagnetic relay RY1 is excited, and the second excitation contact r 12 Is self-holding. The above operation process is a process for confirming that both the first and second operation switches SW1 'and SW2' are normally turned off and the first operation switch SW1 'is normally turned on.
[0055]
While the first operation switch SW1 'is ON, the second operation switch SW2' is operated and its make contact a 2 , A 2 'Turns ON and the break contact b 2 , B 2 Is turned off, the first signal transmission path 11 is opened and the electromagnetic relay RY1 is demagnetized, but the first and second excitation contacts r are turned off by the action of the off-delay circuit 13. 11 , R 12 The OFF operation is delayed for a predetermined time. During this time, the second make contact a of the second operation switch SW2 ' 2 ', The electromagnetic relay RY2 is excited and its first excitation contact r 21 At the second excitation contact r 22 An operation signal is supplied from the operation signal supply path 1 to the machine movable section via the.
[0056]
Conversely, when the first operation switch SW1 'is turned on while the second operation switch SW2' is turned on, the electromagnetic relay RY4 of the second signal transmission path 12 is excited by turning on the second operation switch SW2 '. The second excitation contact r 42 Is self-holding. Next, when the first operation switch SW1 'is turned on, the second make contact a of the first operation switch SW1' is turned on. 1 ', The electromagnetic relay RY3 is excited and its first excitation contact r 31 And the second excitation contact r 32 An operation signal is supplied from the operation signal supply path 1 to the machine movable section via the.
[0057]
According to such a configuration, an operation signal can be generated even when one operation switch SW1 '(SW2') is pressed while the other operation switch SW2 '(SW1') is pressed. For this reason, the usability at the time of two-person operation when the driving operations of the two driving switches have no priority is improved.
Next, an eighth embodiment of the present invention will be described with reference to FIG.
[0058]
In the present embodiment, the signal generation circuit of FIG. 9 is an electronic circuit.
In FIG. 10, the first break contact b of the second operation switch SW2 'of the first signal transmission path 11 is shown. 2 And resistance R A And one input terminal of an AND gate A2 as a first AND circuit. Also, the first make contact a of the second operation switch SW2 'of the second signal transmission path 12 2 And resistance R B And one input terminal of an AND gate A3 as a second AND circuit. Second break contact b of first operation switch SW1 ' 1 'And the second break contact b of the second operation switch SW2' 2 ′ Are connected in series to a third signal transmission path 30, and the second break contact b of the second operation switch SW2 ′ 2 'And the resistance R 3 The other input terminals of the AND gates A2 and A3 are connected to each other via an off-delay circuit 13 having the same configuration as the off-delay circuit 13 in FIG. The AND gates A2 and A3 have a fail-safe configuration.
[0059]
The output of the AND gate A2 is a voltage doubler rectifier circuit REC3 and a capacitor C having an off-delay function. 1 To the trigger terminal of the self-holding circuit 14 via The output of the AND gate A3 is also connected to a voltage doubler rectifier REC3 'and a capacitor C having an off-delay function. 1 To the trigger terminal of the self-holding circuit 14 '. The hold terminal of the self-holding circuit 14 is connected to the second make contact a of the second operation switch SW2 '. 2 'And the resistance R 4 And the hold terminal of the self-holding circuit 14 'is connected to the second make contact a of the first operation switch SW1'. 1 'And the resistance R 5 Connect between.
[0060]
Here, the off-delay circuit 13 corresponds to the tenth off-delay circuit, and the capacitor C 1 , C 1 'Corresponds to the eleventh and twelfth off-delay circuits. The self-holding circuits 14 and 14 'correspond to the fourth and fifth self-holding circuits.
Next, the operation will be described.
A case where the second operation switch SW2 'is turned on while the first operation switch SW1' is turned on will be described.
[0061]
When the first operation switch SW1 'is turned on, the output of the AND gate A2 becomes a logical value 1, and a high-level input signal is applied to the trigger terminal of the self-holding circuit 14. In this state, when the second operation switch SW2 'is turned on, the capacitor C 1 Of the second operation switch SW2 'during the high level of the trigger input to the hold terminal of the self-holding circuit 14. 2 ′ Input a high level signal. As a result, an operation signal is supplied from the voltage doubler rectifier circuit REC2.
[0062]
Conversely, when the first operation switch SW1 'is turned on while the second operation switch SW2' is turned on, the trigger input of the self-holding circuit 14 'is similarly set high based on the output of the AND gate A3. In the meantime, the second make contact a of the first operation switch SW1 ' 1 ′, A high-level hold signal is input to the self-holding circuit 14 ′, and an operation signal is supplied from the voltage doubler rectifier REC 2 ′.
[0063]
According to such a configuration, the usability at the time of two-person operation is improved, and the operation signal generation circuit can be downsized by converting the signal generation circuit into an electronic circuit.
Next, FIGS. 11 and 12 show and explain the circuits of the ninth and tenth embodiments.
The circuits of these embodiments detect by a sensor that no worker is present in a danger area that may come into contact with the machine movable part, and output a signal indicating that no worker is present from the sensor. Only the operation signal is generated.
[0064]
First, the circuit of the ninth embodiment shown in FIG. 11 will be described.
In FIG. 11, for example, a contact Rx of an electromagnetic relay excited by a sensor output of a barrier sensor, a mat sensor, or the like disposed in a danger area (not shown) is interposed in series between the power supply E and the first operation switch SW1. The barrier sensor or the mat sensor generates a high-level output when no person is present in the danger area. When a high-level output is generated from the sensor, the contact Rx is turned on.
[0065]
Therefore, when there is no worker or the like in the danger area, a high-level output is generated from the sensor, the contact Rx is turned on, the power source E is connected to the first operation switch SW1, and both the operation switches SW1, SW2 Based on the operation described above, a signal is input to the signal generation circuit 20 via the first signal transmission paths 11 and 12, and an operation signal of the machine movable section is generated.
It should be noted that any of the signal generation circuits described in the first to sixth embodiments can be applied as the signal generation circuit 20, and an appropriate selection may be made depending on whether a direct current or an alternating current is used as a power supply. . In the circuit configurations shown in FIGS. 9 and 10, it is needless to say that the same effect can be obtained by providing the electromagnetic relay Rx between the first operation switch SW1 'and the power supply E.
[0066]
Next, a circuit according to a tenth embodiment shown in FIG. 12 will be described.
The circuit of the present embodiment is configured to perform a logical AND operation on the output of the AC sensor and the outputs of the first and second signal transmission paths 11 and 12.
In FIG. 12, for example, an optical sensor 21 including a photodiode PD and a phototransistor PT is arranged in a dangerous area. When the light from the photodiode PD is received by the phototransistor PT, the optical sensor 21 generates an AC output signal to indicate that no person exists in the dangerous area. When no light is received by the PT, no AC signal is generated, indicating that a person is present in the danger area. The AC output signal of the optical sensor is input to one input terminal of each of fail-safe AND gates A2 and A3 via the voltage doubler rectifier circuit REC5. The signals on the first and second signal transmission paths 11 are input to the other input terminals of the AND gates A2 and A3, respectively. The AC signals from the AND gates A2 and A3 are rectified by the voltage doubler rectifiers REC6 and REC7 and input to the signal generator 20. The AND gates A2 and A3 are the same as those in FIG.
[0067]
According to this configuration, if no person is present in the danger area and an AC signal from the optical sensor 21 is input to each of the AND gates A2 and A3, the operation is performed based on the operation of the first and second operation switches SW1 and SW2. When a signal is generated in the first and second signal transmission paths 11 respectively, an AC signal is generated from each of the AND gates A2 and A3, and the signal is applied to the signal generation circuit 20 via the voltage doubler rectifier circuits REC6 and REC7. Thus, an operation signal for the movable part of the machine is generated.
[0068]
In the circuit configuration of FIG. 12, when the presence or absence of a person is detected using a mat switch, when no person is present on the mat switch, the photodiode PD is switched by an AC signal and the phototransistor PT receives light. What should be done is.
Therefore, according to the circuit configurations of the ninth and tenth embodiments shown in FIGS. 11 and 12, when a person is present in the danger area, the operation signal of the machine movable part can be reliably stopped, and the safety of the worker can be improved. Properties can be further enhanced.
[0069]
In the circuit using the electromagnetic relay according to the embodiment of the present invention, a back check circuit is configured by using a back contact of each relay (a contact that is turned on when not energized) in consideration of a welding failure of the relay. It goes without saying that the detection of the contact welding failure of the electromagnetic relay is performed.
[0070]
【The invention's effect】
As described above, according to the first aspect of the present invention, the safety of the worker is ensured by appropriately setting the predetermined time from when the first operation switch is operated to when the second operation switch is operated. In addition, both one-person work and two-person work are possible, and the degree of freedom of operation can be provided.
[0071]
If the signal generation circuit is formed into an electronic circuit as in the invention of claim 4, the size of the signal generation circuit can be reduced as compared with the case of the relay circuit of the invention of claim 3. Also, there is no need to consider the welding failure of the relay contacts.
According to the fifth or sixth aspect of the present invention, an AC signal source can be used as a power supply.
[0072]
According to the seventh aspect of the present invention, since the operation signal can be generated by operating either of the operation switches first, the work efficiency of the operator can be improved.
According to the tenth and eleventh aspects of the present invention, an operation signal is generated even when one of the operation switches is operated while the other operation switch is operated, so that there is no priority in the operation order of the operation switches. The convenience in two-person operation is improved.
[0073]
According to the twelfth aspect of the present invention, when a person is present in a danger area that may come into contact with the machine movable part, the generation of an operation signal can be reliably prevented, and the safety of the operator can be further improved.
[Brief description of the drawings]
FIG. 1 is a circuit diagram showing a first embodiment of an operation signal generation circuit according to the present invention.
FIG. 2 is an operation time chart of the first embodiment.
FIG. 3 is an explanatory diagram of a failure detection function of the operation switch according to the first embodiment;
FIG. 4 is a circuit diagram showing a second embodiment of the operation signal generation circuit of the present invention.
FIG. 5 is a circuit diagram showing a third embodiment of the operation signal generation circuit of the present invention.
FIG. 6 is a circuit diagram showing a fourth embodiment of the operation signal generation circuit of the present invention.
FIG. 7 is a circuit diagram showing a fifth embodiment of the operation signal generation circuit of the present invention.
FIG. 8 is a circuit diagram showing a sixth embodiment of the operation signal generation circuit of the present invention.
FIG. 9 is a circuit diagram showing a seventh embodiment of the operation signal generation circuit of the present invention.
FIG. 10 is a circuit diagram showing an operation signal generating circuit according to an eighth embodiment of the present invention.
FIG. 11 is a circuit diagram showing a ninth embodiment of an operation signal generation circuit according to the present invention.
FIG. 12 is a circuit diagram showing a tenth embodiment of an operation signal generation circuit according to the present invention.
FIG. 13 is a circuit diagram showing an example of a conventional operation signal generation circuit.
[Explanation of symbols]
1 Operation signal supply path
11 First signal transmission path
12 Second signal transmission path
13, 13 ', 13 "off delay circuit
14, 14 'self-holding circuit
15,15 ', 16,16' photo interrupter
21 Optical Sensor
30 Third signal transmission path
SW1, SW1 'First operation switch
SW2, SW2 'Second operation switch
RY1 to RY5 Electromagnetic relay
a 1 , A 1 ', A 2 , A 2 ′ Make contact
b 1 , B 1 ', B 2 , B 2 ′ Break contact
r 11 , R 12 , R 21 , R 22 , R 31 , R 32 , R 41, r 42 , R 51 , R 52 Exciting contact

Claims (12)

互いに連動しＯＮ−ＯＦＦ動作が互いに相補の関係にあるメーク接点とブレーク接点を有する運転スイッチを用い、作業者が運転スイッチを操作している期間だけメーク接点がＯＮとなって機械可動部の運転信号が発生する構成の運転信号発生回路であって、前記運転スイッチを２個設け、一方の運転スイッチのメーク接点と他方の運転スイッチのブレーク接点とを直列接続して第１信号伝達経路を形成し、一方の運転スイッチのブレーク接点と他方の運転スイッチのメーク接点とを直列接続して第２信号伝達経路を形成し、作業者の前記運転スイッチ操作に基づいて前記第１及び第２信号伝達経路のいずれか一方の経路が閉路したことを検出してから所定時間内に他方の経路が閉路して信号が伝達された時に前記運転信号を発生する信号発生回路を備えて構成したことを特徴とする運転信号発生回路An operation switch having a make contact and a break contact that are linked to each other and whose ON-OFF operations are complementary to each other is used, and the make contact is turned ON only while the operator is operating the operation switch, and the machine movable part is operated. An operation signal generation circuit configured to generate a signal, wherein two operation switches are provided, and a make contact of one operation switch and a break contact of the other operation switch are connected in series to form a first signal transmission path. The break contact of one of the operation switches and the make contact of the other operation switch are connected in series to form a second signal transmission path, and the first and second signal transmissions are performed based on the operation of the operation switch by an operator. A signal generation for generating the operation signal when the other path is closed and a signal is transmitted within a predetermined time after detecting that one of the paths is closed. Driving signal generating circuit, characterized by being configured with circuitry 前記２つの運転スイッチを予め定めた順序で操作した時に前記信号発生回路から運転信号が発生する構成とした請求項１記載の運転信号発生回路。The operation signal generation circuit according to claim 1, wherein an operation signal is generated from the signal generation circuit when the two operation switches are operated in a predetermined order. 前記信号発生回路は、前記第１信号伝達経路に直列接続した第１電磁リレーと、前記第１信号伝達経路が開路して前記第１電磁リレーの励磁信号が遮断された時に第１電磁リレーの消磁動作を前記所定時間遅延させる第１オフ・ディレー回路と、前記第２信号伝達経路に直列接続した第２電磁リレーとを備え、前記第１電磁リレーの励磁接点と前記第２電磁リレーの第１励磁接点との並列回路を前記第２電磁リレーと直列接続し、前記第２電磁リレーの第２励磁接点を機械可動部の運転信号供給路に直列接続する構成とした請求項２記載の運転信号発生回路。The signal generation circuit includes a first electromagnetic relay connected in series to the first signal transmission path, and a first electromagnetic relay when the first signal transmission path is opened and an excitation signal of the first electromagnetic relay is cut off. A first off-delay circuit for delaying the degaussing operation for the predetermined time; and a second electromagnetic relay connected in series to the second signal transmission path, wherein an exciting contact of the first electromagnetic relay and a second electromagnetic relay of the second electromagnetic relay are provided. 3. The operation according to claim 2, wherein a parallel circuit with one excitation contact is connected in series with the second electromagnetic relay, and a second excitation contact of the second electromagnetic relay is connected in series with an operation signal supply path of the machine movable unit. Signal generation circuit. 前記信号発生回路は、前記第１信号伝達経路からの信号をトリガ信号とし前記第２信号伝達経路からの信号をホールド信号とし前記トリガ信号入力中に前記ホールド信号が入力した時出力を発生して前記トリガ信号を自己保持する第１自己保持回路と、前記第１信号伝達経路が開路した時に前記トリガ信号の停止を前記所定時間遅延させる第２オフ・ディレー回路とを備え、前記第１自己保持回路の出力に基づいて機械可動部の運転信号が発生する構成とした請求項２記載の運転信号発生回路。The signal generating circuit sets a signal from the first signal transmission path as a trigger signal, sets a signal from the second signal transmission path as a hold signal, and generates an output when the hold signal is input during the trigger signal input. A first self-holding circuit that self-holds the trigger signal; and a second off-delay circuit that delays the stop of the trigger signal by the predetermined time when the first signal transmission path is opened. 3. The operation signal generation circuit according to claim 2, wherein an operation signal of the machine movable section is generated based on an output of the circuit. 前記第１及び第２信号伝達経路に、それぞれフォトインタラプタを介装し、各フォトインタラプタを介して前記第１自己保持回路にトリガ信号とホールド信号を入力させる構成である請求項４記載の運転信号発生回路。The operation signal according to claim 4, wherein a photo interrupter is interposed in each of the first and second signal transmission paths, and a trigger signal and a hold signal are input to the first self-holding circuit via each photo interrupter. Generator circuit. 前記第１及び第２信号伝達経路に、それぞれトランスを介装し、各トランスを介して前記第１自己保持回路にトリガ信号とホールド信号を入力させる構成である請求項４記載の運転信号発生回路。5. The operation signal generation circuit according to claim 4, wherein a transformer is interposed in each of the first and second signal transmission paths, and a trigger signal and a hold signal are input to the first self-holding circuit via each transformer. . 前記２つの運転スイッチの操作順序に関係なく、信号発生回路から運転信号が発生可能な構成である請求項１記載の運転信号発生回路。2. The operation signal generation circuit according to claim 1, wherein an operation signal can be generated from the signal generation circuit regardless of an operation order of the two operation switches. 前記信号発生回路は、前記第１信号伝達経路に設けられる第３及び第４電磁リレーと、前記第１信号伝達経路が開路して前記第３電磁リレーの励磁信号が遮断された時に第３電磁リレーの消磁動作を前記所定時間遅延させる第３オフ・ディレー回路と、前記第２信号伝達経路に設けられる第５及び第６電磁リレーと、前記第２信号伝達経路が開路して前記第５電磁リレーの励磁信号が遮断された時に第５電磁リレーの消磁動作を前記所定時間遅延させる第４オフ・ディレー回路とを備え、前記第３電磁リレーと第４電磁リレーとを互いに並列接続し、第５電磁リレーの励磁接点と第４電磁リレーの第１励磁接点との並列回路を、前記第３電磁リレーと並列且つ第４電磁リレーと直列に接続すると共に、前記第５電磁リレーと第６電磁リレーとを互いに並列接続し、第３電磁リレーの励磁接点と第６電磁リレーの第１励磁接点との並列回路を、前記第５電磁リレーと並列且つ第６電磁リレーと直列に接続し、前記第４電磁リレーの第２励磁接点と前記第６電磁リレーの第２励磁接点との並列回路を、機械可動部の運転信号供給路に直列接続する構成とした請求項７記載の運転信号発生回路。The signal generation circuit includes third and fourth electromagnetic relays provided in the first signal transmission path, and a third electromagnetic relay when the first signal transmission path is opened and an excitation signal of the third electromagnetic relay is cut off. A third off-delay circuit that delays the demagnetizing operation of the relay by the predetermined time, fifth and sixth electromagnetic relays provided in the second signal transmission path, and the fifth electromagnetic path when the second signal transmission path is opened. A fourth off-delay circuit that delays the demagnetizing operation of the fifth electromagnetic relay by the predetermined time when the excitation signal of the relay is cut off, and connects the third electromagnetic relay and the fourth electromagnetic relay in parallel with each other; A parallel circuit of the exciting contact of the fifth electromagnetic relay and the first exciting contact of the fourth electromagnetic relay is connected in parallel with the third electromagnetic relay and in series with the fourth electromagnetic relay, and the fifth electromagnetic relay and the sixth electromagnetic relay are connected. With relay A parallel circuit of an exciting contact of a third electromagnetic relay and a first exciting contact of a sixth electromagnetic relay is connected in parallel with each other, and connected in parallel with the fifth electromagnetic relay and in series with the sixth electromagnetic relay. 8. The operation signal generating circuit according to claim 7, wherein a parallel circuit of a second excitation contact of the relay and a second excitation contact of the sixth electromagnetic relay is connected in series to an operation signal supply path of the machine movable section. 前記信号発生回路は、前記第１信号伝達経路からの信号をトリガ信号とし前記第２信号伝達経路からの信号をホールド信号とし前記トリガ信号入力中に前記ホールド信号が入力した時出力を発生して前記トリガ信号を自己保持する第２自己保持回路と、前記第２信号伝達経路からの信号をトリガ信号とし前記第１信号伝達経路からの信号をホールド信号とし前記トリガ信号入力中に前記ホールド信号が入力した時出力を発生して前記トリガ信号を自己保持する第３自己保持回路と、前記第１信号伝達経路が開路した時に前記第２自己保持回路のトリガ信号の停止を前記所定時間遅延させる第５オフ・ディレー回路と、前記第２信号伝達経路が開路した時に前記第３自己保持回路のトリガ信号の停止を前記所定時間遅延させる第６オフ・ディレー回路とを備え、前記第２及び第３自己保持回路のそれぞれの出力に基づいて機械可動部の運転信号が発生する構成とした請求項７記載の運転信号発生回路。The signal generating circuit sets a signal from the first signal transmission path as a trigger signal, sets a signal from the second signal transmission path as a hold signal, and generates an output when the hold signal is input during the trigger signal input. A second self-holding circuit for self-holding the trigger signal; a signal from the second signal transmission path as a trigger signal; a signal from the first signal transmission path as a hold signal; A third self-holding circuit that generates an output when input and self-holds the trigger signal; and a third self-holding circuit that delays the stop of the trigger signal of the second self-holding circuit by the predetermined time when the first signal transmission path is opened. A fifth off-delay circuit, and a sixth off-delay circuit for delaying the stop of the trigger signal of the third self-holding circuit by the predetermined time when the second signal transmission path is opened. And a circuit, said second and third self holding each driving signal generation circuit according to claim 7, wherein the driving signal of the machine movable part is configured to generate, based on the output of the circuit. 前記２つの運転スイッチが、それぞれ第１及び第２のブレーク接点と第１及び第２のメーク接点を有し、一方の運転スイッチの第１メーク接点と他方の運転スイッチの第１ブレーク接点とを直列接続して前記第１信号伝達経路を形成し、一方の運転スイッチの第１ブレーク接点と他方の運転スイッチの第１メーク接点とを直列接続して前記第２信号伝達経路を形成し、一方の運転スイッチの第２ブレーク接点と他方の運転スイッチの第２ブレーク接点とを直列接続して第３信号伝達経路を形成する構成とし、
前記信号発生回路は、前記第１信号伝達経路に設けられる第７電磁リレーと、前記第１信号伝達経路が開路して前記第７電磁リレーの励磁信号が遮断された時に第７電磁リレーの消磁動作を所定時間遅延させる第７オフ・ディレー回路と、前記第２信号伝達経路に設けられる第８電磁リレーと、前記第２信号伝達経路が開路して前記第８電磁リレーの励磁信号が遮断された時に第８電磁リレーの消磁動作を所定時間遅延させる第８オフ・ディレー回路と、前記第３信号伝達経路に設けられる第９電磁リレーと、前記第３信号伝達経路が開路して前記第９電磁リレーの励磁信号が遮断された時に第９電磁リレーの消磁動作を所定時間遅延させる第９オフ・ディレー回路と、前記一方の運転スイッチの第２メーク接点に直列接続する第１０電磁リレーと、他方の運転スイッチの第２メーク接点に直列接続する第１１電磁リレーとを備え、前記各電磁リレーを互いに並列接続し、第７電磁リレーの第１励磁接点と第１１電磁リレーの第１励磁接点との並列回路を前記第１１電磁リレーと前記他方の運転スイッチの第２メーク接点との間に直列接続し、前記第８電磁リレーの第１励磁接点と第１０電磁リレーの第１励磁接点との並列回路を第１０電磁リレーと前記一方の運転スイッチの第２メーク接点との間に直列接続し、第９電磁リレーの第１励磁接点と第７電磁リレーの第２励磁接点との並列回路を前記第７電磁リレーに直列接続し、第８電磁リレーの第２励磁接点と第９電磁リレーの第２励磁接点との並列回路を第８電磁リレーに直列接続し、前記第１０電磁リレーの第２励磁接点と前記第１１電磁リレーの第２励磁接点との並列回路を機械可動部の運転信号供給路に直列接続する構成とした請求項７記載の運転信号発生回路。The two operation switches have first and second break contacts and first and second make contacts, respectively, and a first make contact of one operation switch and a first break contact of the other operation switch. The first signal transmission path is formed in series, and the first break contact of one operation switch and the first make contact of the other operation switch are connected in series to form the second signal transmission path. The second break contact of the operation switch and the second break contact of the other operation switch are connected in series to form a third signal transmission path,
The signal generation circuit includes a seventh electromagnetic relay provided in the first signal transmission path, and a demagnetization of the seventh electromagnetic relay when the first signal transmission path is opened and an excitation signal of the seventh electromagnetic relay is cut off. A seventh off-delay circuit for delaying the operation for a predetermined time, an eighth electromagnetic relay provided in the second signal transmission path, and an excitation signal of the eighth electromagnetic relay is cut off when the second signal transmission path is opened. An eighth off-delay circuit for delaying the demagnetizing operation of the eighth electromagnetic relay for a predetermined time, a ninth electromagnetic relay provided in the third signal transmission path, and the ninth electromagnetic relay being opened when the third signal transmission path is opened. A ninth off-delay circuit for delaying the demagnetizing operation of the ninth electromagnetic relay for a predetermined time when the excitation signal of the electromagnetic relay is interrupted, and a tenth electromagnetic relay connected in series to the second make contact of the one operation switch And an eleventh electromagnetic relay connected in series to the second make contact of the other operation switch, wherein the electromagnetic relays are connected in parallel with each other, and the first excitation contact of the seventh electromagnetic relay and the eleventh electromagnetic relay of the eleventh electromagnetic relay are provided. A parallel circuit with the first exciting contact is connected in series between the eleventh electromagnetic relay and the second make contact of the other operation switch, and the first exciting contact of the eighth electromagnetic relay and the first exciting contact of the tenth electromagnetic relay are connected. A parallel circuit with the exciting contact is connected in series between the tenth electromagnetic relay and the second make contact of the one operation switch, and the first exciting contact of the ninth electromagnetic relay and the second exciting contact of the seventh electromagnetic relay are connected to each other. Are connected in series to the seventh electromagnetic relay, and a parallel circuit of the second exciting contact of the eighth electromagnetic relay and the second exciting contact of the ninth electromagnetic relay is connected in series to the eighth electromagnetic relay. With the second excitation contact of the electromagnetic relay Serial 11th second operating signal generating circuit according to claim 7, wherein where the structure is connected in series-parallel circuit to the operating signal supply path of the machine movable part of the excitation contact points of the electromagnetic relay. 前記２つの運転スイッチが、それぞれ第１及び第２のブレーク接点と第１及び第２のメーク接点を有し、一方の運転スイッチの第１メーク接点と他方の運転スイッチの第１ブレーク接点とを直列接続して前記第１信号伝達経路を形成し、一方の運転スイッチの第１ブレーク接点と他方の運転スイッチの第１メーク接点とを直列接続して前記第２信号伝達経路を形成し、一方の運転スイッチの第２ブレーク接点と他方の運転スイッチの第２ブレーク接点とを直列接続して第３信号伝達経路を形成する構成とし、
前記信号発生回路は、前記第３信号伝達経路が開路した時に当該第３信号伝達経路からの信号の停止を所定時間遅延させる第１０オフ・ディレー回路と、前記第１信号伝達経路からの信号を一方の入力信号とし前記第１０オフ・ディレー回路からの出力信号を他方の入力信号とする第１論理積回路と、前記第２信号伝達経路からの信号を一方の入力信号とし前記第１０オフ・ディレー回路からの出力信号を他方の入力信号とする第２論理積回路と、前記第１論理積回路の出力信号をトリガ信号とし前記他方の運転スイッチの第２メーク接点からの信号をホールド信号とし前記トリガ信号入力中に前記ホールド信号が入力した時出力を発生して前記トリガ信号を自己保持する第４自己保持回路と、前記第２論理積回路からの信号をトリガ信号とし前記一方の運転スイッチの第２メーク接点からの信号をホールド信号とし前記トリガ信号入力中に前記ホールド信号が入力した時出力を発生して前記トリガ信号を自己保持する第５自己保持回路と、前記第１信号伝達経路が開路した時に前記第４自己保持回路のトリガ信号の停止を前記所定時間遅延させる第１１オフ・ディレー回路と、前記第２信号伝達経路が開路した時に前記第５自己保持回路のトリガ信号の停止を前記所定時間遅延させる第１２オフ・ディレー回路とを備え、前記第４及び第５自己保持回路のそれぞれの出力に基づいて機械可動部の運転信号が発生する構成とした請求項７記載の運転信号発生回路。The two operation switches have first and second break contacts and first and second make contacts, respectively, and a first make contact of one operation switch and a first break contact of the other operation switch. The first signal transmission path is formed in series, and the first break contact of one operation switch and the first make contact of the other operation switch are connected in series to form the second signal transmission path. The second break contact of the operation switch and the second break contact of the other operation switch are connected in series to form a third signal transmission path,
The signal generation circuit includes: a tenth off-delay circuit for delaying a stop of a signal from the third signal transmission path for a predetermined time when the third signal transmission path is opened; and a signal from the first signal transmission path. A first AND circuit that uses one of the input signals as an output signal from the tenth off-delay circuit as the other input signal, and a signal from the second signal transmission path as one input signal and outputs the tenth off-delay circuit; A second AND circuit that uses the output signal from the delay circuit as the other input signal; and uses the output signal of the first AND circuit as a trigger signal and a signal from the second make contact of the other operation switch as a hold signal. A fourth self-holding circuit that generates an output when the hold signal is input during the trigger signal input and self-holds the trigger signal; and a signal from the second AND circuit is a trigger signal. A fifth self-holding circuit that generates an output when the hold signal is input during input of the trigger signal and that self-holds the trigger signal, wherein the signal from the second make contact of the one operation switch is a hold signal; An eleventh off-delay circuit for delaying the stop of the trigger signal of the fourth self-holding circuit by the predetermined time when the first signal transmission path is opened; and the fifth self-holding circuit when the second signal transmission path is opened. And a twelfth off-delay circuit for delaying the stop of the trigger signal by the predetermined time, wherein an operation signal of the mechanical movable section is generated based on the output of each of the fourth and fifth self-holding circuits. Item 7. An operation signal generating circuit according to Item 7. 前記機械可動部と接触する可能性のある危険領域内に作業者が存在しない時に出力を発生する監視手段を設け、該監視手段から出力が発生している時のみ前記第１及び第２信号伝達経路の信号伝達を可能とする構成とした請求項１〜１１のいずれか１つに記載の運転信号発生回路。Monitoring means for generating an output when no worker is present in a danger area which may come into contact with the machine movable part, and transmitting the first and second signals only when an output is generated from the monitoring means; The operation signal generation circuit according to any one of claims 1 to 11, wherein the operation signal generation circuit has a configuration capable of transmitting a signal on a path.
JP4521396A 1995-10-06 1996-03-01 Operation signal generation circuit Expired - Fee Related JP3597629B2 (en)

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