JP3576064B2 - Control equipment for construction machinery - Google Patents

Description

【０１２２】
この表１に示すように、まず、ローパワーとすべき場合は、エンジン５０からのエンジン出力は、第１油圧ポンプ５１にバケット１０８を駆動するのに最低限必要なエンジン出力を供給すべくバケット最低要求割合（例えば約３０％）配分され、第２油圧ポンプ５２にスティック１０４を十分な作動スピードで作動させるのに必要なエンジン出力を供給すべくバケット要求割合よりも大きいスティック要求割合（例えば約７０％）配分される。
【０１２３】
つまり、ローパワーとすべき場合は、各油圧ポンプ５１，５２に配分される合計馬力の上限値がローパワー上限馬力（例えば約１２０ＰＳ；約８７．６ｋＷ）に設定される。そして、このエンジン馬力は、第１油圧ポンプ５１にバケット１０８を駆動するのに最低限必要なエンジン馬力を供給すべくバケット駆動要求馬力（例えば約３６ＰＳ；約２６．２８ｋＷ）配分され、第２油圧ポンプ５２にスティック１０４を十分な作動スピードで作動させるのに必要なエンジン馬力を供給すべくバケット要求馬力よりも大きいスティック要求馬力（例えば約８４ＰＳ；約６１．３２ｋＷ）配分されることになる。
【０１２４】
一方、ハイパワーとすべき場合は、エンジン５０からのエンジン出力は、上述の表１に示すように、第１油圧ポンプ５１にバケット１０８を十分な作動スピードで作動させるのに必要なエンジン出力を供給すべくバケット要求割合（例えば約４０％）配分され、第２油圧ポンプ５２にスティック１０４を十分な作動スピードで作動させるのに必要なエンジン出力を供給すべくバケット要求割合よりも大きいスティック要求割合（例えば約６０％）配分される。
【０１２５】
つまり、ハイパワーとすべき場合は、各油圧ポンプ５１，５２に配分される合計馬力の上限値がハイパワー上限馬力（エンジンの最大馬力；例えば約１４０ＰＳ；約１０２．２０ｋＷ）に設定される。そして、このエンジン馬力は、第１油圧ポンプ５１にバケット１０８を十分な作動スピードで作動させるのに必要なエンジン馬力を供給すべくバケット要求馬力（例えば約５６ＰＳ；約４０．８８ｋＷ）配分され、第２油圧ポンプ５２にスティック１０４を十分な作動スピードで作動させるのに必要なエンジン馬力を供給すべくバケット要求馬力よりも大きいスティック要求馬力（例えば約８４ＰＳ；約６１．３２ｋＷ）配分されることになる。
【０１２６】
なお、ここで第１油圧ポンプ５１に配分されるエンジン馬力を所定馬力（例えば約５６ＰＳ；約４０．８８ｋＷ）としているのは、バケット１０８を駆動するためにバケット駆動用油圧シリンダ１０７へ作動油を供給する第１油圧ポンプ５１をローパワーのときよりも大きなエンジン馬力（ハイパワー）で駆動することでバケット１０８の作動スピードを確保して作業効率を向上させるためである。
【０１２７】
上述のように、ローパワー，ハイパワーのいずれも場合も、エンジン出力を第２油圧ポンプ５２へ多く配分しているのは、第２油圧ポンプ５２からスティック駆動用油圧シリンダ１０６へ供給される作動油の流量を多くして、最も作業効率に影響を与えるスティック１０４の作動スピードを向上させることで、全体として作業効率を向上させるためである。
【０１２８】
また、上述のように、作業機にかかる負荷圧力に応じてエンジン馬力（ポンプ馬力）を可変に設定する制御において、複数の油圧ポンプ５１，５２の合計馬力が小さくなるように設定された場合であっても、馬力配分を可変に設定しうる制御を実施することによって、優先させて作動させたい油圧アクチュエータ（ここではスティック駆動用油圧シリンダ）に馬力を多く配分（例えば高馬力設定時と同等の馬力を配分）することで、優先させて作動させたい油圧アクチュエータの作業効率を向上させることができる。
【０１２９】
また、上述のように、作業機にかかる負荷圧力に応じてエンジン馬力（ポンプ馬力）を可変に設定する制御と、複数の油圧ポンプ間の馬力配分を可変に設定する制御とを、各操作部材からの操作信号（電気信号）に基づいて組み合わせることで、システム全体の効率（生産性／ヒートロスを含む）を改善することができる。
【０１３０】
なお、各操作部材５４がフル操作されていない場合のエンジン出力の配分割合（配分馬力）は、上述の各操作部材５４がフル操作されている場合のエンジン出力の配分割合（配分馬力）を、各操作部材５４の操作量に応じて補正することにより設定すれば良い。
エクスカベーション制御部６Ｃは、エクスカベーション判定手段４によってエクスカベーション時、即ちスティックイン操作と旋回操作とが同時に行なわれていると判定された場合に、スティック駆動用油圧シリンダ１０６と旋回モータ１１０とに過不足なく作動油が供給されるように各油圧ポンプ５１，５２へのエンジン出力の配分が設定され、この配分内で油圧ポンプ５１，５２が作動するように、各油圧ポンプ５１，５２のポンプ傾転角を制御するものである。なお、各油圧ポンプ５１，５２のポンプ傾転角制御は、上述の基本傾転角制御部６Ａの場合と同様である。
【０１３１】
これにより、エンジン出力を各油圧ポンプ５１，５２の双方に最適配分することができ、第１油圧ポンプ５１及び第２油圧ポンプ５２のそれぞれのポンプ吐出流量が、スティック１０４の作動と上部旋回体１０２の旋回とを同時に行なうのに十分なポンプ吐出流量となるとともに、エンジン出力を効率的に利用することで燃費を向上させることができる。
【０１３２】
具体的には、エクスカベーション制御部６Ｃでは、ローパワー／ハイパワー判定手段２からの判定結果に基づいて、後述するようにエンジン５０からのエンジン出力を各油圧ポンプ５１，５２に配分する配分割合（配分馬力）の設定と、各油圧ポンプ５１，５２の合計馬力の上限出力（上限馬力）を設定するようになっている。なお、合計馬力の上限出力（上限馬力）は、エンジン出力（エンジン馬力）のフル出力（フル馬力）に相当する。
【０１３３】
ここでは、ハイパワーとすべき場合には上限馬力がエンジンの最大馬力（例えば約１４０ＰＳ；約１０２．２０ｋＷ）に設定される。一方、ローパワーとすべき場合には上限馬力がエンジンの最大馬力以下の所定馬力（例えば約１２０ＰＳ；約８７．６０ｋＷ）に設定される。
また、エクスカベーション制御部６Ｃでは、スティック用操作部材５４ｂ及び旋回用操作部材５４ｄの操作量に相当する電気信号に基づいて各油圧ポンプ５１，５２へのエンジン出力配分を設定するようになっている。
【０１３４】
ここで、以下の表２はエンジン出力の配分割合例と上限馬力の設定例をそれぞれ示している。この表２では各操作部材５４がフル操作されている場合のエンジン出力の配分割合を示している。なお、表２ではエンジン出力の配分割合に応じたポンプ馬力も示している。また、第１油圧ポンプ５１は、主にスティック駆動用油圧シリンダ１０６へ作動油を供給しており、第２油圧ポンプ５２は、主に旋回モータ１１０へ作動油を供給している。
【０１３５】
【表２】

【０１３６】
この表２に示すように、例えばならし作業の場合、スティック駆動用油圧シリンダ１０６の負荷圧力が低く、従ってポンプ吐出圧力が所定値よりも小さいため、ローパワーと判定され、エンジン５０からのエンジン出力は、第１油圧ポンプ５１にスティック１０４を十分な作動スピードで作動させるのに必要なエンジン出力を供給すべくスティック要求割合（例えば約７０％）配分され、第２油圧ポンプ５２に上部旋回体１０２を旋回させるのに最低限必要なエンジン出力を供給すべく旋回最低要求割合（例えば約３０％）配分される。
【０１３７】
このときの各油圧ポンプ５１，５２に配分される合計馬力の上限値がローパワー上限馬力（例えば約１２０ＰＳ；約８７．６０ｋＷ）に設定される。そして、このエンジン馬力は、第１油圧ポンプ５１にスティック１０４を十分な作動スピードで作動させるのに必要なエンジン馬力を供給すべくスティック要求馬力（例えば約８４ＰＳ；約６１．３２ｋＷ）配分され、第２油圧ポンプ５２に上部旋回体１０２を旋回させるのに最低限必要なエンジン馬力を供給すべく旋回最低要求馬力（例えば約３６ＰＳ；約２６．２８ｋＷ）配分されることになる。
【０１３８】
一方、側壁けずり作業（側壁掘削）である場合、スティック駆動用油圧シリンダ１０６の負荷圧力が高く、従ってポンプ吐出圧力が所定値よりも大きいため、ハイパワーと判定され、上述の表２に示すように、第１油圧ポンプ５１にスティック１０４を十分な作動スピードで作動させるのに必要なエンジン出力を供給すべくスティック要求割合（例えば約７５％）配分され、第２油圧ポンプ５２に上部旋回体１０２を旋回させるのに最低限必要なエンジン出力を供給すべく旋回最低要求割合（例えば約２５％）配分される。
【０１３９】
このときの各油圧ポンプ５１，５２に配分される合計馬力の上限値がハイパワー上限馬力（エンジンの最大馬力；例えば約１４０ＰＳ；約１０２．２０ｋＷ）に設定される。そして、このエンジン馬力は、第１油圧ポンプ５１にスティック１０４を十分な作動スピードで作動させるのに必要なエンジン馬力を供給すべくスティック要求馬力（例えば約１０４ＰＳ；約７５．９２ｋＷ）配分され、第２油圧ポンプ５２に上部旋回体１０２を旋回させるのに最低限必要なエンジン馬力を供給すべく旋回最低要求馬力（例えば約３６ＰＳ；約２６．２８ｋＷ）配分されることになる。
【０１４０】
なお、ここで第１油圧ポンプ５１に配分されるエンジン馬力を所定馬力（例えば約１０４ＰＳ；約７５．９２ｋＷ）としているのは、スティック１０４を作動させるためにスティック駆動用油圧シリンダ１０６へ作動油を供給する第１油圧ポンプ５１をローパワーのときよりも大きなエンジン馬力（ハイパワー）で駆動することでスティック１０４の作動スピードを確保して作業効率を向上させるためである。
【０１４１】
このように、ローパワー，ハイパワーのいずれも場合も、エンジン出力を第１油圧ポンプ５１へ多く配分しているのは、第１油圧ポンプ５１からスティック駆動用油圧シリンダ１０６へ供給される作動油の流量を多くして、最も作業効率に影響を与えるスティック１０４の作動スピードを向上させることで、全体として作業効率を向上させるためである。
【０１４２】
また、上述のように、作業機にかかる負荷圧力に応じてエンジン馬力（ポンプ馬力）を可変に設定する制御において、複数の油圧ポンプ５１，５２の合計馬力が小さくなるように設定された場合であっても、馬力配分を可変に設定しうる制御を実施することによって、優先させて作動させたい油圧アクチュエータ（ここではスティック駆動用油圧シリンダ）に馬力を多く配分することで、優先させて作動させたい油圧アクチュエータの作業効率を向上させることができる。
【０１４３】
また、上述のように、作業機にかかる負荷圧力に応じてエンジン馬力（ポンプ馬力）を可変に設定する制御と、複数の油圧ポンプ間の馬力配分を可変に設定する制御とを、各操作部材からの操作信号（電気信号）に基づいて組み合わせることで、システム全体の効率（生産性／ヒートロスを含む）を改善することができる。
【０１４４】
なお、各操作部材５４がフル操作されていない場合のエンジン出力の配分割合（配分馬力）は、上述の各操作部材５４がフル操作されている場合のエンジン出力の配分割合（配分馬力）を、各操作部材５４の操作量に応じて補正することにより設定すれば良い。
リフト／旋回制御部６Ｄは、リフト／旋回判定手段５によってリフト／旋回時、即ちブームアップ操作と旋回操作とが同時に行なわれていると判定された場合に、ブーム用操作部材５４ａ及び旋回用操作部材５４ｄの操作量に相当する電気信号に基づいて、ブーム駆動用油圧シリンダ１０５と旋回モータ１１０とに過不足なく作動油が供給されるように各油圧ポンプ５１，５２へのエンジン出力の配分が設定され、このようなエンジン出力配分になるように各油圧ポンプ５１，５２のポンプ傾転角を制御するものである。なお、各油圧ポンプ５１，５２のポンプ傾転角制御は、上述の基本傾転角制御部６Ａの場合と同様である。
【０１４５】
これにより、エンジン出力を各油圧ポンプ５１，５２の双方に最適配分することができ、第１油圧ポンプ５１及び第２油圧ポンプ５２のそれぞれのポンプ吐出流量が、ブーム１０３の作動と上部旋回体１０２の旋回とを同時に行なうのに十分なポンプ吐出流量となるとともに、エンジン出力を効率的に利用することで燃費を向上させることができる。
【０１４６】
具体的には、リフト／旋回制御部６Ｄでは、後述するようにエンジン５０からのエンジン出力を各油圧ポンプ５１，５２に配分する配分割合（配分馬力）の設定と、各油圧ポンプ５１，５２の合計馬力の上限出力（上限馬力）を設定するようになっている。ここでは、上限馬力はエンジンの最大馬力（例えば約１４０ＰＳ；約１０２．２０ｋＷ）に設定される。
【０１４７】
また、リフト／旋回制御部６Ｄでは、ブーム用操作部材５４ａ及び旋回用操作部材５４ｄの操作量に相当する電気信号に基づいて各油圧ポンプ５１，５２へのエンジン出力配分を設定するようになっている。
ここで、以下の表３はエンジン出力の配分割合例を示している。この表３では各操作部材５４がフル操作されている場合のエンジン出力の配分割合を示している。なお、表３ではエンジン出力の配分割合に応じたエンジン馬力も示している。また、第１油圧ポンプ５１は、主にブーム駆動用油圧シリンダ１０５へ作動油を供給しており、第２油圧ポンプ５２は、主に旋回モータ１１０へ作動油を供給している。
【０１４８】
【表３】

【０１４９】
この表３に示すように、エンジン５０からのエンジン出力は第１油圧ポンプ５１にブーム１０３を十分な作動スピードで作動させるのに必要なエンジン出力を供給すべくブーム要求割合（例えば約７０％）配分され、第２油圧ポンプ５２に上部旋回体１０２を旋回させるのに最低限必要なエンジン出力を供給すべく旋回最低要求割合（例えば約３０％）配分される。
【０１５０】
このときの各油圧ポンプ５１，５２に配分される合計馬力の上限値が上限馬力（例えば約１４０ＰＳ；約１０２．２０ｋＷ）に設定される。これは、ブームアップ作業の場合には常にハイパワーを必要とするからである。そして、このエンジン馬力は、第１油圧ポンプ５１にブーム１０３を十分な作動スピードで作動させるのに必要なエンジン馬力を供給すべくブーム要求馬力（例えば約９８ＰＳ；約７１．５４ｋＷ）配分され、第２油圧ポンプ５２に上部旋回体１０２を旋回させるのに最低限必要なエンジン馬力を供給すべく旋回最低要求馬力（例えば約４２ＰＳ；約３０．６６ｋＷ）配分されることになる。
【０１５１】
また、エンジン出力を第１油圧ポンプ５１へ多く配分しているのは、第１油圧ポンプ５１からブーム駆動用油圧シリンダ１０５へ供給される作動油の流量を多くして、ブーム１０３の作動スピードを向上させることで作業効率を向上させるためである。
なお、各操作部材５４がフル操作されていない場合のエンジン出力の配分割合（配分馬力）は、上述の各操作部材５４がフル操作されている場合のエンジン出力の配分割合（配分馬力）を、各操作部材５４の操作量に応じて補正することにより設定すれば良い。
【０１５２】
本実施形態にかかる建設機械の制御装置は、上述のように構成され、本制御にかかるメインルーチンは図８のフローチャートに示すような手順で動作する。 まず、ステップＳ１０では各操作部材５４からの電気信号を読み込む、ステップＳ２０へ進む。
ステップＳ２０では、ディギング判定手段３，エクスカベーション判定手段４及びリフト／旋回判定手段５が、スティック用操作部材５４ｂからの電気信号に基づいてスティックイン操作が行なわれたか否かを判定し、この判定の結果、ディギング判定手段３，エクスカベーション判定手段４によりスティックイン操作が行なわれたと判定された場合は、ステップＳ３０へ進む。
【０１５３】
ステップＳ３０では、ローパワー／ハイパワー判定手段２が圧力センサ７２，７３からの検出情報（ポンプ吐出圧に相当する）を読み込んで、ステップＳ４０へ進み、ステップＳ４０で、ローパワー／ハイパワー判定手段２が、圧力センサ７２，７３により検出されたポンプ吐出圧が所定圧（例えば２００ｋｇｆ／ｃｍ^２；約１９．６ＭＰａ）以上か否かを判定する。
【０１５４】
この判定の結果、ポンプ吐出圧が所定圧（例えば２００ｋｇｆ／ｃｍ^２；約１９．６ＭＰａ）以上であると判定した場合は、ステップＳ５０へ進み、ポンプ傾転角制御手段６のディギング制御部６Ｂ及びエクスカベーション制御部６Ｃが、各油圧ポンプ５１，５２に配分されるエンジン出力の上限値をハイパワー上限馬力（例えば約１４０ＰＳ；約１０２．２０ｋＷ）に設定し、この所定馬力を各油圧ポンプ５１，５２に最適パワー配分してポンプ傾転角制御を行なうべく、ハイパワー時の最適パワー配分ポンプ傾転角制御ルーチンを実行する。なお、ハイパワー時の最適パワー配分ポンプ傾転角制御ルーチンについては後述する。
【０１５５】
一方、ステップＳ４０で、ポンプ吐出圧が所定圧（例えば２００ｋｇｆ／ｃｍ^２；約１９．６ＭＰａ）以上でないと判定した場合は、ステップＳ６０へ進み、ポンプ傾転角制御手段６のディギング制御部６Ｂ及びエクスカベーション制御部６Ｃは、各油圧ポンプ５１，５２に配分されるエンジン出力の上限値をローパワー上限馬力（例えば約１２０ＰＳ；約８７．６０ｋＷ）に設定し、この所定馬力を各油圧ポンプ５１，５２に最適パワー配分してポンプ傾転角制御を行なうべく、ローパワー時の最適パワー配分ポンプ傾転角制御ルーチンを実行する。なお、ローパワー時の最適パワー配分ポンプ傾転角制御ルーチンについては後述する。
【０１５６】
ところで、ステップＳ２０で、スティックイン操作が行なわれていないと判定した場合は、ステップＳ７０へ進み、リフト／旋回時の最適パワー配分ポンプ傾転角制御ルーチンを実行する。なお、リフト／旋回時の最適パワー配分ポンプ傾転角制御ルーチンについては後述する。
次に、本実施形態にかかる建設機械の制御装置は、ハイパワー時の最適パワー配分ポンプ傾転角制御ルーチン（図８のステップＳ５０）は、図９のフローチャートに示すような手順で動作する。
【０１５７】
つまり、ステップＡ１０ではディギング判定手段３及びエクスカベーション判定手段４が、バケット用操作部材５４ｃからの電気信号に基づいてバケット操作が行なわれたか否かを判定する。
その判定の結果、ディギング判定手段３がバケット操作が行なわれたと判定した場合は、スティックイン操作とバケット操作とが同時に行なわれた場合であり、これはディギング作業であると考えられるため、ステップＡ５０に進み、ポンプ傾転角制御手段６のディギング制御部６Ｂが、スティック用操作部材５４ｂ及びバケット用操作部材５４ｃからの電気信号に基づいて、エンジン５０からのエンジン出力が最適配分されるように各油圧ポンプ５１，５２へのエンジン出力の配分を設定する。
【０１５８】
ここでは、ディギング制御部６Ｂは、エンジン出力を第１油圧ポンプ５１にバケット要求割合（例えば約４０％）配分し、第２油圧ポンプ５２にスティック要求割合（例えば約６０％）配分する。つまり、ディギング制御部６Ｂは、上限値がハイパワー上限馬力（例えば約１４０ＰＳ；約１０２．２０ｋＷ）に設定されたエンジン馬力を、第１油圧ポンプ５１にバケット要求馬力（例えば約５６ＰＳ；約４０．８８ｋＷ）配分し、第２油圧ポンプ５２にスティック要求馬力（例えば約８４ＰＳ；約６１．３２ｋＷ）配分する。
【０１５９】
そして、このようなエンジン出力配分になるように各油圧ポンプ５１，５２のポンプ傾転角を制御して、リターンする。
一方、ステップＡ１０で、エクスカベーション判定手段４がバケット操作が行なわれていないと判定した場合は、ステップＡ２０へ進み、さらにエクスカベーション判定手段４が旋回用操作部材５４ｄからの電気信号に基づいて旋回操作が行なわれたか否かを判定する。
【０１６０】
この判定の結果、エクスカベーション判定手段４が旋回操作が行なわれたと判定した場合は、スティックイン操作と旋回操作とが同時に行なわれた場合であり、これはエクスカベーション作業であると考えられるため、ステップＡ３０の処理を行なう。
次いで、ステップＡ３０では、エクスカベーション制御部６Ｃが、スティック用操作部材５４ｂ及び旋回用操作部材５４ｄからの電気信号に基づいて、エンジン５０からのエンジン出力が最適配分されるように各油圧ポンプ５１，５２へのエンジン出力の配分を設定する。
【０１６１】
ここでは、エクスカベーション制御部６Ｃは、エンジン出力を第１油圧ポンプ５１にスティック要求割合（例えば約７５％）配分し、第２油圧ポンプ５２に旋回最低要求割合（例えば約２５％）配分する。つまり、エクスカベーション制御部６Ｃは、上限値がハイパワー上限馬力（例えば約１４０ＰＳ；約１０２．２０ｋＷ）に設定されたエンジン馬力を、第１油圧ポンプ５１にスティック要求馬力（例えば約１０４ＰＳ，約７５．９２ｋＷ）配分し、第２油圧ポンプ５２に旋回最低要求馬力（例えば約３６ＰＳ；約２６．２８ｋＷ）配分する。
【０１６２】
そして、このようなエンジン出力配分になるように各油圧ポンプ５１，５２のポンプ傾転角を制御して、リターンする。
ところで、ステップＡ２０で、エクスカベーション判定手段４が旋回操作が行なわれていないと判定した場合は、エクスカベーション作業でないと考えられるため、エクスカベーション時のポンプ傾転角制御を行なわずに、リターンする。
【０１６３】
次に、本実施形態にかかる建設機械の制御装置は、ローパワー時の最適パワー配分ポンプ傾転角制御ルーチン（図８のステップＳ６０）を行なうべく、図１０のフローチャートに示すように動作する。
つまり、ステップＢ１０ではディギング判定手段３及びエクスカベーション判定手段４が、バケット用操作部材５４ｃからの電気信号に基づいてバケット操作が行なわれたか否かを判定する。
【０１６４】
その判定の結果、ディギング判定手段３がバケット操作が行なわれたと判定した場合は、スティックイン操作とバケット操作とが同時に行なわれた場合であり、これはディギング作業であると考えられるため、ステップＢ５０に進み、ポンプ傾転角制御手段６のディギング制御部６Ｂが、スティック用操作部材５４ｂ及びバケット用操作部材５４ｃからの電気信号に基づいて、エンジン５０からのエンジン出力が最適配分されるように各油圧ポンプ５１，５２へのエンジン出力の配分を設定する。
【０１６５】
ここでは、ディギング制御部６Ｂは、エンジン出力を第１油圧ポンプ５１にバケット最低要求割合（例えば約３０％）配分し、第２油圧ポンプ５２にスティック要求割合（例えば約７０％）配分する。つまり、ディギング制御部６Ｂは、上限値がローパワー上限馬力（例えば約１２０ＰＳ；約８７．６０ｋＷ）に設定されたエンジン馬力を、第１油圧ポンプ５１にバケット最低要求馬力（例えば約３６ＰＳ；約２６．２８ｋＷ）配分し、第２油圧ポンプ５２にスティック要求馬力（例えば約８４ＰＳ；約６１．３２ｋＷ）配分する。
【０１６６】
そして、このようなエンジン出力配分になるように各油圧ポンプ５１，５２のポンプ傾転角を制御して、リターンする。
一方、ステップＢ１０で、エクスカベーション判定手段４がバケット操作が行なわれていないと判定した場合は、ステップＢ２０へ進み、さらにエクスカベーション判定手段４が旋回用操作部材５４ｄからの電気信号に基づいて旋回操作が行なわれたか否かを判定する。
【０１６７】
この判定の結果、エクスカベーション判定手段４が旋回操作が行なわれたと判定した場合は、スティックイン操作と旋回操作とが同時に行なわれた場合であり、これはエクスカベーション作業であると考えられるため、ステップＢ３０の処理を行なう。
次いで、ステップＢ３０では、ポンプ傾転角制御手段６のエクスカベーション制御部６Ｃが、スティック用操作部材５４ｂ及び旋回用操作部材５４ｄからの電気信号に基づいて、エンジン５０からのエンジン出力が最適配分されるように各油圧ポンプ５１，５２へのエンジン出力の配分を設定する。
【０１６８】
ここでは、エクスカベーション制御部６Ｃは、エンジン出力を第１油圧ポンプ５１にスティック要求割合（例えば約７０％）配分し、第２油圧ポンプ５２に旋回最低要求割合（例えば約３０％）配分する。つまり、エクスカベーション制御部６Ｃは、上限値がローパワー上限馬力（例えば約１２０ＰＳ；約８７．６０ｋＷ）に設定されたエンジン馬力を、第１油圧ポンプ５１にスティック要求馬力（例えば約８４ＰＳ；約６１．３２ｋＷ）配分し、第２油圧ポンプ５２に旋回最低要求馬力（例えば約３６ＰＳ；約２６．２８ｋＷ）配分する。
【０１６９】
そして、このようなエンジン出力配分になるように各油圧ポンプ５１，５２のポンプ傾転角を制御して、リターンする。
ところで、ステップＢ２０で、エクスカベーション判定手段４が旋回操作が行なわれていないと判定した場合は、エクスカベーション作業でないと考えられるため、エクスカベーション時のポンプ傾転角制御を行なわずに、リターンする。
【０１７０】
次に、本実施形態にかかる建設機械の制御装置は、リフト／旋回時の最適パワー配分ポンプ傾転角制御ルーチン（図８のステップＳ７０）を行なうべく、図１１のフローチャートに示すように動作する。
つまり、ステップＣ１０ではリフト／旋回判定手段５が、ブーム用操作部材５４ａからの電気信号に基づいてブームアップ操作が行なわれたか否かを判定し、この判定の結果、ブームアップが行なわれたと判定した場合は、ステップＣ２０へ進み、さらに旋回用操作部材５４ｄからの電気信号に基づいて旋回操作が行なわれたか否かを判定する。
【０１７１】
この判定の結果、旋回操作が行なわれたと判定した場合は、ブームアップ操作と旋回操作とが同時に行なわれた場合であり、これはリフト／旋回動作であると考えられるため、ステップＣ３０へ進み、ポンプ傾転角制御手段６のリフト／旋回制御部６Ｃが、ブーム用操作部材５４ａ及び旋回用操作部材５４ｄからの電気信号に基づいて、エンジン５０からのエンジン出力が最適配分されるように各油圧ポンプ５１，５２へのエンジン出力の配分を設定する。
【０１７２】
ここでは、リフト／旋回制御部６Ｃは、エンジン出力を第１油圧ポンプ５１にブーム要求割合（例えば約７０％）配分し、第２油圧ポンプ５２に旋回最低要求割合（例えば約３０％）配分する。つまり、リフト／旋回制御部６Ｃは、上限値が上限馬力（例えば約１４０ＰＳ；約１０２．２０ｋＷ）に設定されたエンジン馬力を第１油圧ポンプ５１にブーム要求馬力（例えば約９８ＰＳ；約７１．５４ｋＷ）配分し、第２油圧ポンプ５２に旋回最低要求馬力（例えば約４２ＰＳ；約３０．６６ｋＷ）配分する。
【０１７３】
そして、このようなエンジン出力配分になるように各油圧ポンプ５１，５２のポンプ傾転角を制御して、リターンする。
ところで、ステップＣ１０でリフト／旋回判定手段５がブームアップ操作が行なわれていないと判定した場合、及びステップＣ２０でリフト／旋回判定手段５が旋回操作が行なわれていないと判定した場合は、リフト／旋回動作でないと考えられるため、リフト／旋回時のポンプ傾転角制御を行なわずに、リターンする。
【０１７４】
したがって、本実施形態にかかる建設機械の制御装置によれば、エンジン出力が各油圧ポンプ５１，５２に最適配分されるため、油圧ポンプ５１，５２に十分なエンジン出力が供給されず、ポンプ出力が足りなくなって作業スピードが低下するのを防止することができ、作業効率を向上させることができるという利点がある。
【０１７５】
また、油圧ポンプ５１，５２に必要以上にエンジン出力が供給されてしまって、配管圧損の増加を招いて馬力損失を発生させたり、これに起因する作動油温度の上昇による内部リークの増大や、クーリングのために余分な馬力を消費するといったシステム全体の非効率部分を改善することができるという利点もある。
なお、上述の実施形態では、２つの油圧ポンプが設けられており、これらの油圧ポンプにエンジン出力を配分しているが、２以上の複数の油圧ポンプを設けて、各油圧アクチュエータにかかる作業負荷に応じてこれらの油圧ポンプのそれぞれにエンジン出力を配分するようにしても良い。
【０１７６】
また、上述の実施形態では、油圧ポンプ５１，５２は斜板回転式ピストンポンプとして構成しているが、コントローラ１からの作動信号によりポンプ吐出流量を制御しうる可変容量ポンプであれば良く、例えば斜軸式ピストンポンプや可変吐出量形ベーンポンプ等であっても良い。
また、上述の実施形態では、ディギング制御部６Ｂ，エクスカベーション制御部６Ｃにおいて、ローパワー／ハイパワー判定手段２の判定結果に基づいて作業装置１１８にかかる作業負荷に応じてローパワー時とハイパワー時とで各油圧ポンプ５１，５２に配分されるエンジン出力の上限値を変更しているが、リフト／旋回制御部６Ｄにおいてもローパワー／ハイパワー判定手段２の判定結果に基づいて作業装置１１８にかかる作業負荷に応じてローパワー時とハイパワー時とで各油圧ポンプ５１，５２に配分されるエンジン出力の上限値を変更するようにしても良い。
【０１７７】
また、上述の実施形態では、ディギング制御部６Ｂ，エクスカベーション制御部６Ｃにおいて、ローパワー／ハイパワー判定手段２の判定結果に基づいて作業装置１１８にかかる作業負荷に応じてローパワー時とハイパワー時とで油圧ポンプ５１，５２に配分されるエンジン出力を制御しているが、基本傾転角制御部６Ａにおいてローパワー／ハイパワー判定手段２の判定結果に基づいて作業装置１１８にかかる作業負荷に応じてローパワー時とハイパワー時とで油圧ポンプ５１，５２に配分されるエンジン出力を制御するようにしても良い。
【０１７８】
また、上述の実施形態では、本発明をネガティブフローコントロールを行なう建設機械の制御装置に適用する場合について説明しているが、本発明をポジティブフローコントロールを行なう建設機械の制御装置に適用しても良い。
【０１７９】
【発明の効果】
以上詳述したように、請求項１〜８記載の本発明の建設機械の制御装置によれば、エンジン出力が各油圧ポンプに最適配分されるため、油圧ポンプに十分なエンジン出力が供給されず、ポンプ出力が足りなくなって作業スピードが低下するのを防止することができ、作業効率を向上させることができるという利点がある。また、油圧ポンプに必要以上にエンジン出力が供給されてしまうのを防止でき、配管圧損の増加を招いて馬力損失を発生させたり、これに起因する作動油温度の上昇による内部リークの増大や、クーリングのために余分な馬力を消費するといったシステム全体の非効率部分を改善することができるという利点もある。
【図面の簡単な説明】
【図１】本発明の一実施形態にかかる建設機械の制御装置における最適パワー配分によるポンプ傾転角制御を説明するための制御ブロック図である。
【図２】本発明の一実施形態にかかる建設機械の制御装置の全体構成図である。
【図３】本発明の一実施形態にかかる建設機械の制御装置の制御弁を説明するための模式図である。
【図４】一般的な建設機械における配管圧損による馬力損失及び油圧アクチュエータへ供給可能な有効馬力を説明するための図である。
【図５】本発明の一実施形態にかかる建設機械の制御装置におけるネガティブフローコントロールの要求流量とネガコン圧との関係を示す図である。
【図６】本発明の一実施形態にかかる建設機械の制御装置におけるネガティブフローコントロールの許容流量とポンプ吐出圧との関係を示す図である。
【図７】本発明の一実施形態にかかる建設機械の制御装置におけるネガティブフローコントロールを説明するためのフローチャートである。
【図８】本発明の一実施形態にかかる建設機械の制御装置における最適パワー配分ポンプ傾転角制御のメインルーチンを説明するためのフローチャートである。
【図９】本発明の一実施形態にかかる建設機械の制御装置におけるハイパワー時のポンプ傾転角制御ルーチンを説明するためのフローチャートである。
【図１０】本発明の一実施形態にかかる建設機械の制御装置におけるローパワー時のポンプ傾転角制御ルーチンを説明するためのフローチャートである。
【図１１】本発明の一実施形態にかかる建設機械の制御装置におけるリフト／旋回時のポンプ傾転角制御ルーチンを説明するためのフローチャートである。
【図１２】従来の建設機械を示す模式的斜視図である。
【符号の説明】
１ コントローラ（制御手段）
２ ローパワー／ハイパワー判定手段
３ ディギング判定手段
４ エクスカベーション判定手段
５ リフト／旋回判定手段
６ ポンプ傾転角制御手段
６Ａ 基本傾転角制御部
６Ｂ ディギング制御部
６Ｃ エクスカベーション制御部
６Ｄ リフト／旋回制御部
７ 旋回用比例減圧弁制御手段
５１ 第１油圧ポンプ
５２ 第２油圧ポンプ
５４ 操作部材
５４ａ ブーム用操作部材
５４ｂ スティック用操作部材
５４ｃ バケット用操作部材
５４ｄ 旋回用操作部材
６３ 旋回用制御弁
６３ａ，６３ｂ 旋回用比例減圧弁
１０２ 上部旋回体[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to control of a construction machine that controls the flow rate of hydraulic oil from a hydraulic pump provided in the construction machine by a control valve to control the operation of hydraulic actuators such as a boom cylinder, a stick cylinder, a bucket cylinder, and a swing motor. Related to the device.
[0002]
[Prior art]
In general, a construction machine such as a hydraulic shovel includes an upper revolving unit 102, a lower traveling unit 100, and a working device 118, as shown in FIG.
The lower traveling unit 100 includes a right track 100R and a left track 100L that can be driven independently of each other, while the upper revolving unit 102 is provided so as to be able to pivot in a horizontal plane with respect to the lower traveling unit 100. . For this reason, a swing motor (swing hydraulic actuator) is attached to the upper swing body 102.
The working device 118 mainly includes a boom 103, a stick 104, a bucket 108, and the like. The boom 103 is pivotally attached to the upper swing body 102 so as to be rotatable. A stick 104 is connected to the tip of the boom 103 so as to be rotatable in a vertical plane.
[0003]
A boom drive hydraulic cylinder (boom cylinder, boom drive hydraulic actuator) 105 for driving the boom 103 is provided between the upper swing body 102 and the boom 103. A stick driving hydraulic cylinder (stick cylinder, stick driving hydraulic actuator) 106 for driving the stick 104 is provided between them. A bucket driving hydraulic cylinder (bucket cylinder, bucket driving hydraulic actuator) 107 for driving the bucket 108 is provided between the stick 104 and the bucket 108.
[0004]
Each of the cylinders 105 to 107 and the swing motor includes a plurality (generally two) of hydraulic pumps driven by an engine (mainly a diesel engine), a boom control valve, a stick control valve, and a bucket control. A hydraulic circuit (not shown) including a plurality of control valves such as a valve and a turning control valve is connected, and hydraulic oil of a predetermined hydraulic pressure is supplied from these hydraulic pumps via the respective control valves. It is driven in accordance with the supplied hydraulic pressure.
[0005]
With such a configuration, the boom 103 can rotate in the directions of arrows a and b in the figure, the stick 104 can rotate in the directions of arrows c and d in the figure, and the bucket 108 can rotate in the directions of arrows e and f in the figure. Is configured.
The rotation of the boom 103 in the direction of the arrow a in the figure is called boom up, and the rotation in the direction of the arrow b in the figure is called boom down. The rotation of the stick 104 in the direction of the arrow c in the figure is called stick-out, and the rotation of the stick 104 in the direction of the arrow d in the figure is called stick-in. The rotation of the bucket 108 in the direction of arrow e in the figure is called bucket open, and the rotation in the direction of arrow f in the figure is called bucket-in.
[0006]
The driving operation room 101 includes left lever, right lever, left pedal, and right pedal as operation members for controlling the operation (running, turning, boom turning, stick turning, and bucket turning) of the excavator. Etc. are provided.
Also, a plurality of work mode switches are provided in the driver's cab 101, and various modes such as a truck loading mode (boom priority mode), a trenching mode (swing priority mode), a leveling mode, and a tamping mode are provided. The driving operator can appropriately select the optimum one according to the work. In a normal case where such a selection is not made, the operation of the stick 104 is important in the operation of the construction machine, and the operation of the stick 104 needs to be given the highest priority. It has become.
[0007]
Then, for example, when the operator operates these operating members such as levers and pedals, the control valves of the hydraulic circuit are controlled, and the cylinders 105 to 107 and the swing motor are driven. The upper revolving structure 102 can be rotated by rotating the 104, the bucket 108, and the like. A pilot hydraulic circuit is provided to control each control valve. Thereby, in order to operate the boom 103 and the stick 104, the boom operating member and the stick operating member in the driving operation room 101 are operated, and the pilot oil pressure is applied to the boom control valve and the stick control valve through the pilot oil passage. Then, the boom control valve and the stick control valve are driven to required positions. Thereby, the supply and discharge of the hydraulic oil to the boom drive hydraulic cylinder 105 and the stick drive hydraulic cylinder 106 are adjusted, and these cylinders 105 and 106 are driven to expand and contract to required lengths.
[0008]
In order to operate the upper swing body 102, the swing operation member in the operation room 101 is operated to apply pilot hydraulic pressure to the swing control valve through the pilot oil passage, thereby turning the swing control valve to a required value. Move to position. As a result, the supply and discharge of hydraulic oil to and from the swing motor are adjusted, and the swing motor is driven.
As described above, in the hydraulic excavator, the working devices 118 such as the boom 103, the stick 104, and the bucket 108 are driven by extending and retracting each of the cylinders 105 to 107, and the swing motor is driven to swing the upper swing body 102. By doing so, excavations such as wall scraping work and leveling work, digging such as excavation work, and lift / turn operations such as loading work are performed.
[0009]
Here, at the time of the excavation, the stick-in operation and the turning operation are performed simultaneously. At the time of digging, the stick-in operation and the bucket operation are performed simultaneously. Further, during the lift / turn, the boom-up operation and the turn operation are performed simultaneously.
During these operations, hydraulic oil is supplied from each of the plurality of hydraulic pumps to each hydraulic actuator. In this case, since these hydraulic pumps are driven by one engine, the engine output from the engine is used in accordance with the pump load of each hydraulic pump on the engine. Note that the engine output includes engine power, engine torque, and engine horsepower output from the engine.
[0010]
[Problems to be solved by the invention]
However, in the control of the conventional hydraulic pump, the engine output (total horsepower, total pump horsepower) required to drive the plurality of hydraulic pumps and the engine output distribution between the plurality of hydraulic pumps (horsepower between the plurality of hydraulic pumps) Allocation) are set as fixed values.
[0011]
For example, if the maximum horsepower of the engine is about 140 horsepower (about 140 PS; about 102.20 kW), the total horsepower (total pump horsepower) of the plurality of hydraulic pumps driven by this one engine is about 140 horsepower (about 140 PS). About 102.20 kW). Also, the horsepower distribution among the plurality of hydraulic pumps is usually set to be approximately equal and fixed.
[0012]
If the total horsepower and the horsepower distribution are fixedly set in this manner, the horsepower loss increases depending on the working conditions (for example, the magnitude of the load pressure and the combination of the actuating actuators), and the sufficient horsepower required for the work is obtained. (Power) cannot be obtained, or a sufficient work speed cannot be obtained, resulting in reduced work efficiency.
Looking at the relationship between the fixedly set engine horsepower (total horsepower, total pump horsepower) and the load pressure, under the condition that the horsepower is fixed at a fixed value, if the load pressure is low, the hydraulic pump will Although the flow rate of the discharged hydraulic oil increases (pump flow rate = horsepower (constant) / load pressure), if the flow rate of the hydraulic oil discharged from the hydraulic pump increases, the pressure loss of the piping system increases, and the horsepower due to the pipe pressure loss Since the loss increases, the effective horsepower (effective operating oil pressure) that can be supplied to the hydraulic actuator out of the engine horsepower (pump horsepower) decreases, and a sufficient force (power) required for the work cannot be obtained.
[0013]
In addition, the horsepower loss due to the pipe pressure loss becomes heat and raises the temperature of the hydraulic oil, and due to this temperature rise, the viscosity of the hydraulic oil decreases and the internal leak of hydraulic equipment increases, and the hydraulic system Efficiency (efficiency of supplying hydraulic oil to the hydraulic actuator) is deteriorated, and sufficient work speed is not obtained, resulting in work efficiency being deteriorated.
Furthermore, a large oil cooler is required to prevent an excessive rise in operating oil temperature, and when a cooling fan is provided, extra horsepower is required to drive the cooling fan. .
[0014]
Next, when looking at the relationship between horsepower distribution (horsepower distribution of engine horsepower) among a plurality of hydraulic actuators, priority is given to a case where a plurality of operating members are operated in conjunction to operate a plurality of hydraulic actuators simultaneously. There are hydraulic actuators that are desired to be powerfully operated, and hydraulic actuators that are required to perform a minimum required operation.
[0015]
For example, when excavation work is performed by performing stick-in and bucket-in simultaneously, the stick 104 is a work machine that wants to operate with high priority and the bucket 108 only needs to operate at a minimum. Work machine.
By the way, in consideration of such an operation pattern (for example, when a plurality of hydraulic actuators are simultaneously operated as in an excavation operation), a hydraulic circuit is configured such that a hydraulic pump corresponding to each hydraulic actuator is connected. Have been.
[0016]
However, for example, even if the second hydraulic pump is connected to the stick driving hydraulic cylinder 106 via an oil passage and the bucket driving hydraulic cylinder 107 is connected to the first hydraulic pump, If both the first and second hydraulic pumps are driven by one engine and the horsepower distribution between the first and second hydraulic pumps is equally divided, the stick drive hydraulic pressure to be preferentially activated Since a sufficient amount of hydraulic oil is not supplied to the cylinder 106 and sufficient hydraulic pressure cannot be obtained, the stick 104 cannot be powerfully operated, and work efficiency (work cycle time and the like) is poor.
[0017]
Here, more engine horsepower (pump horsepower) is distributed to the hydraulic pump (in the above example, the second pump connected to the stick driving hydraulic cylinder 106) connected to the hydraulic actuator that wants to be powerfully operated. It is thought that work efficiency can be improved by doing so.
However, when trying to uniformly perform both the control for variably setting the total horsepower in accordance with the load pressure applied to the work implement and the control for varying the horsepower distribution among a plurality of hydraulic pumps regardless of the type of work. However, the following problems may occur.
[0018]
For example, when performing control to variably set the total horsepower according to the load pressure applied to the work machine, if the horsepower is set to be uniformly reduced according to the load pressure regardless of the type of work, Depending on the type of work, work efficiency will be reduced. For example, if the total horsepower is set to be smaller in accordance with the load pressure when the boom is raised, a problem that the cycle time becomes longer occurs. Therefore, when the boom is raised, it is necessary to use the full horsepower of the engine horsepower as the pump horsepower of each hydraulic pump in the full load pressure range.
[0019]
Further, when performing control to variably set the horsepower distribution among a plurality of hydraulic pumps, if the horsepower distribution is uniformly performed regardless of the combination of the operated hydraulic actuators, the combination of the plurality of hydraulic actuators In some cases, optimal horsepower distribution is not performed, and the engine output cannot be used efficiently.
[0020]
The present invention has been made in view of such a problem, and has improved the efficiency of the entire system by reducing the loss of the engine output, and has improved the working efficiency by enabling the efficient use of the engine output. It is an object of the present invention to provide a control device for a construction machine.
[0021]
[Means for Solving the Problems]
Therefore, the control device for a construction machine according to the first aspect of the present invention includes a plurality of hydraulic pumps driven by an engine provided in the construction machine to discharge hydraulic oil in a tank and a plurality of operation units operated by an operator. lever When, A plurality of hydraulic actuators connected to the plurality of hydraulic pumps; Control means for controlling the tilt angle of the plurality of hydraulic pumps to adjust the discharge flow rate from the plurality of hydraulic pumps, the control means comprising: When it is determined that the operation is to simultaneously operate two hydraulic actuators among the plurality of hydraulic actuators based on the electric signals from the plurality of operation levers, the operation is performed according to a combination of the two hydraulic actuators. A distribution ratio of engine output distributed to a plurality of hydraulic pumps connected to each of the two hydraulic actuators is set, and the distribution ratio is set to the distribution ratio. The tilt angle of each of the plurality of hydraulic pumps is controlled.
[0022]
According to a second aspect of the present invention, there is provided a construction machine control device according to the first aspect. , Multiple A pressure sensor that detects a pump discharge pressure of hydraulic oil discharged by the number of hydraulic pumps, and a control unit controls each of the plurality of hydraulic pumps based on an upper limit output set according to a detection signal from the pressure sensor. The engine output to be distributed is set, and the tilt angles of the plurality of hydraulic pumps are controlled so as to achieve the distributed output.
[0023]
Claim 3 According to a first aspect of the present invention, there is provided a control device for a construction machine according to the first aspect, wherein the plurality of operations are performed. lever Is operated for turning the construction machine. lever And a stick operation operated to operate a stick provided on the construction machine lever Wherein the control means performs the turning operation described above. lever And stick operation lever Excavation determining means for determining whether the operation is an excavation operation involving a turning operation and a stick operation based on an electric signal from the hydraulic pump, and a tilt of the hydraulic pump to adjust a discharge flow rate from the hydraulic pump. Pump displacement angle control means for controlling the displacement angle, and when the pump displacement angle control means is determined to be an excavation work by the excavation determination means, Setting a distribution ratio of an engine output distributed to a plurality of hydraulic pumps connected to the turning hydraulic actuator and the stick driving hydraulic actuator among the plurality of hydraulic actuators, so that the distribution ratio becomes the distribution ratio. The tilt angle of each of the plurality of hydraulic pumps is controlled.
[0024]
Claim 4 The control device for a construction machine according to the present invention is described in the claims. 3 The apparatus according to claim 1, further comprising a pressure sensor that detects a pump discharge pressure of hydraulic oil discharged from the plurality of hydraulic pumps, wherein the pump tilt angle control unit detects an upper limit output set according to a detection signal from the pressure sensor. The engine output to be allocated to each of the plurality of hydraulic pumps is set by subtracting the minimum required turning power required to turn the construction machine, and the tilt of each of the plurality of hydraulic pumps is set so as to achieve the distributed output. It is characterized in that the turning angle is controlled.
[0025]
Claim 5 According to a first aspect of the present invention, there is provided a control device for a construction machine according to the first aspect, wherein the plurality of operations are performed. lever Is operated for operating a stick provided to the construction machine. lever And a bucket operation operated to operate a bucket provided in the construction machine lever Wherein said control means operates said stick. lever And bucket operation lever Digging determining means for determining whether or not the digging operation involves stick operation and bucket operation based on an electric signal from the controller, and controls a tilt angle of the hydraulic pump to adjust a discharge flow rate from the hydraulic pump. Pump tilt angle control means that performs a digging operation when the digging determination means determines that it is a digging operation. Setting a distribution ratio of an engine output distributed to a plurality of hydraulic pumps connected to the stick driving hydraulic actuator and the bucket driving hydraulic actuator among the plurality of hydraulic actuators, so that the distribution ratio becomes the distribution ratio. The tilt angle of each of the plurality of hydraulic pumps is controlled.
[0026]
Claim 6 The control device for a construction machine according to the present invention is described in the claims. 5 The apparatus according to claim 1, further comprising a pressure sensor that detects a pump discharge pressure of hydraulic oil discharged from the plurality of hydraulic pumps, wherein the pump tilt angle control unit detects an upper limit output set according to a detection signal from the pressure sensor. The engine output distributed to each of the plurality of hydraulic pumps is set by subtracting the minimum required output of the bucket required to operate the bucket, and each of the plurality of hydraulic pumps is tilted so as to have the distributed output. The feature is to control the angle.
[0027]
Claim 7 According to a first aspect of the present invention, there is provided a control device for a construction machine according to the first aspect, wherein the plurality of operations are performed. lever Is operated for operating a boom provided in the construction machine. lever And a turning operation operated to turn the construction machine. lever And
The control means operates the boom. lever And turning operation lever Lift / turn determination means for determining whether or not a lift / turn involving a boom operation and a turn operation based on an electric signal from the hydraulic pump, and a tilt of the hydraulic pump to adjust a discharge flow rate from the hydraulic pump. Pump tilt angle control means for controlling a shift angle, wherein the pump tilt angle control means determines that a lift / turn is being performed by the lift / turn determination means. Setting a distribution ratio of engine output distributed to a plurality of hydraulic pumps connected to the boom driving hydraulic actuator and the turning hydraulic actuator among the plurality of hydraulic actuators, so that the distribution ratio becomes equal to the distribution ratio. The tilt angle of each of the plurality of hydraulic pumps is controlled.
[0028]
Claim 8 The control device for a construction machine according to the present invention is described in the claims. 7 The apparatus according to claim 1, further comprising a pressure sensor that detects a pump discharge pressure of hydraulic oil discharged from the plurality of hydraulic pumps, wherein the pump tilt angle control unit detects an upper limit output set according to a detection signal from the pressure sensor. The engine output to be allocated to each of the plurality of hydraulic pumps is set by subtracting the minimum required turning power required to turn the construction machine, and the tilt of each of the plurality of hydraulic pumps is set so as to achieve the distributed output. It is characterized in that the turning angle is controlled.
[0029]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
First, a construction machine according to the present embodiment will be described.
The construction machine is a construction machine (working machine) such as a hydraulic shovel, as described in the related art (see FIG. 12), and includes the upper swing body 102, the lower traveling body 100, and the working device 118. I have.
[0030]
The lower traveling unit 100 includes a right track 100R and a left track 100L that can be driven independently of each other, while the upper revolving unit 102 is provided so as to be able to pivot in a horizontal plane with respect to the lower traveling unit 100. .
The working device 118 mainly includes a boom 103, a stick 104, a bucket 108, and the like. The boom 103 is pivotally attached to the upper swing body 102 so as to be rotatable. A stick 104 is connected to the tip of the boom 103 so as to be rotatable in a vertical plane.
[0031]
A boom drive hydraulic cylinder (boom cylinder, boom drive hydraulic actuator) 105 for driving the boom 103 is provided between the upper swing body 102 and the boom 103. A stick driving hydraulic cylinder (stick cylinder, stick driving hydraulic actuator) 106 for driving the stick 104 is provided between them. A bucket driving hydraulic cylinder (bucket cylinder, bucket driving hydraulic actuator) 107 for driving the bucket 108 is provided between the stick 104 and the bucket 108.
[0032]
With such a configuration, the boom 103 is rotatable in the directions a and b in the figure, the stick 104 is rotatable in the directions c and d in the figure, and the bucket 108 is configured to be rotatable in the directions e and f in the figure. I have.
Here, FIG. 2 is a diagram schematically showing a main part of a hydraulic circuit of such a hydraulic shovel.
[0033]
As shown in FIG. 2, the left track 100L and the right track 100R are provided with traveling motors 109L and 109R as independent power sources, respectively. A swing motor 110 for swinging the upper swing body 102 is provided.
The traveling motors 109L and 109R and the turning motor 110 are configured as hydraulic motors that operate by hydraulic pressure, and a plurality of (two in this case) driven by an engine (mainly, a diesel engine) 50 as described later. Hydraulic oil from hydraulic pumps 51 and 52 is supplied at a predetermined pressure via hydraulic circuit 53, and hydraulic motors 109L, 109R and 110 are driven in accordance with the hydraulic pressure supplied in this manner. Has become.
[0034]
Here, the hydraulic pumps 51 and 52 discharge the working oil in the reservoir tank 70 as a predetermined oil pressure, and here, are swash plate rotary type piston pumps (piston type variable displacement pumps, variable discharge amount type piston pumps). It is configured. These hydraulic pumps 51 and 52 can adjust the pump discharge flow rate by changing the stroke amount of a piston (not shown) provided in the hydraulic pump.
[0035]
That is, in these hydraulic pumps 51 and 52, one end of the piston is configured to abut against a swash plate (creep plate: not shown), and the inclination (tilt angle) of the swash plate is determined by a controller 1 described later. Thus, the pump discharge flow rate can be adjusted by changing the stroke amount of the piston by changing the stroke amount based on the operation signal from the pump.
[0036]
As described above, the inclination of the swash plate can be changed based on the operation signal from the controller 1, and in addition to the pressure of the operating oil in the oil passage constituting the hydraulic circuit, the operation of each operation member 54 by the operator is performed. Since the operation amount can also be taken into consideration, the operator's driving feeling can be improved as compared with the conventional method in which the pressure of the hydraulic oil in the oil passage is guided to change the inclination of the swash plate. .
[0037]
The engine 50 can be set by the operator by switching an engine speed setting dial. Here, the maximum engine speed (for example, about 2000 rpm) and the minimum engine speed (for example, about 1000 rpm) are set. ) Can be switched in multiple stages. It should be noted that the engine speed is not limited to the one that is switched stepwise as described above, but may be one that can be changed smoothly.
[0038]
Also, for each of the cylinders 105 to 107, similarly to the traveling motors 109L and 109R and the turning motor 110, hydraulic oil supplied from a plurality (two in this case) of hydraulic pumps 51 and 52 driven by the engine 50 is provided. Is driven by the hydraulic pressure. The total horsepower of the engine 50 is consumed to drive the hydraulic pumps 51 and 52 and a pilot pump 83 described later.
[0039]
In addition, a plurality of driving levers such as a left lever, a right lever, a left pedal, and a right pedal for controlling the operation (running, turning, boom turning, stick turning, and bucket turning) of the hydraulic excavator are provided in the driving operation room 101. An operation member 54 is provided. These operation members 54 are configured as electric operation members (for example, electric operation levers), and output an electric signal corresponding to the operation amount to a controller (control means) 1 described later.
[0040]
Further, a plurality of work mode switches are also provided in the driving cab 101, and various modes such as a boom priority mode, a swing priority mode, a leveling mode, and a tamping mode are optimally set by the driver according to the work. The items can be appropriately selected. In a normal case where such a selection is not made, the operation of the stick 104 is important in the operation of the construction machine, and the operation of the stick 104 needs to be given the highest priority.
[0041]
Then, for example, when the operator operates these operation members 54, the control valves 57 to 60 and 62 to 65 interposed in the hydraulic circuit 53 are controlled, and the cylinders 105 to 107 and the hydraulic motors 109L and 109R are controlled. , 110 are driven. Thus, the upper swing body 102 can be swung, the boom 103, the stick 104, the bucket 108, and the like can be swung, and the hydraulic shovel can be run.
[0042]
In addition, what is operated when rotating the boom 103 is the boom operating member 54a, what is operated when rotating the stick 104 is the stick operating member 54b, and what is operated when rotating the bucket 108 is The bucket operation member 54c and the member that is operated when the upper swing body 102 is swung are referred to as a swing operation member 54d.
[0043]
Next, the hydraulic circuit 53 for controlling each of these cylinders will be described.
The hydraulic circuit 53 includes a first circuit unit 55 and a second circuit unit 56, as shown in FIG.
The first circuit portion 55 includes an oil passage 61 connected to the first hydraulic pump 51, a control valve 57 for a right running motor, a control valve 58 for a bucket, and a control valve 58 for a first boom interposed in the oil passage 61. A control valve such as the control valve 59 and the second stick control valve 60 is provided.
[0044]
Then, hydraulic oil from the first hydraulic pump 51 is supplied to the right traveling motor 109R through the oil passage 61 and the right traveling motor control valve 57, and drives the right traveling motor 109R. The hydraulic oil from the first hydraulic pump 51 is supplied to the bucket driving hydraulic cylinder 107 via the oil passage 61 and the bucket control valve 58, and is also supplied via the oil passage 61 and the first boom control valve 59. To the boom drive hydraulic cylinder 105, and further to the stick drive hydraulic cylinder 106 via the oil passage 61 and the second stick control valve 60, thereby driving each of the cylinders 105, 106, 107. It has become.
[0045]
Further, a throttle 81 is provided downstream of the oil passage 61 of the first circuit portion 55, and the hydraulic oil from the first hydraulic pump 51 is returned to the reservoir tank 70 through the throttle 81.
The second circuit portion 56 includes an oil passage 66 connected to the second hydraulic pump 52, a left traveling motor control valve 62, a turning motor control valve 63, and a first stick control valve interposed in the oil passage 66. 64, a control valve such as a second boom control valve 65, and a throttle 82.
[0046]
Then, the hydraulic oil from the second hydraulic pump 52 is supplied to the left traveling motor 109L via the oil passage 66 and the left traveling motor control valve 62, whereby the left traveling motor 109L is driven. I have. The hydraulic oil from the second hydraulic pump 52 is supplied to the turning motor 110 via the oil passage 66 and the turning motor control valve 63, whereby the turning motor 110 is driven. Further, the hydraulic oil from the second hydraulic pump 52 is supplied to the stick driving hydraulic cylinder 106 via the oil passage 66 and the first stick control valve 64, and the oil passage 66 and the second boom control valve 65 , And is supplied to the boom drive hydraulic cylinder 105, whereby the respective cylinders 105 and 106 are driven.
[0047]
A throttle 82 is provided on the downstream side of the oil passage 66 of the second circuit portion 56, and the hydraulic oil from the second hydraulic pump 52 is returned to the reservoir tank 70 through the throttle 82.
The control valves 57 to 60 and 62 to 65 are housed in a control unit (not shown).
[0048]
As described above, in the present embodiment, the second hydraulic circuit unit 56 of the second circuit unit 56 is configured to supply sufficient hydraulic oil to the important stick 104 in the operation of the construction machine even when operating simultaneously with the other work machine 118. In addition to the hydraulic oil from the hydraulic pump 52, hydraulic oil from the first hydraulic pump 51 of the first circuit unit 55 is also supplied to the stick driving hydraulic cylinder 106.
[0049]
For this reason, the first stick control valve 64 is interposed in the oil passage 66 of the second circuit portion 56, and the second stick control valve 60 is interposed in the oil passage 61 of the first circuit portion 55. The first stick control valve 64 is controlled by the proportional control valves 64a and 64b, and the second stick control valve 60 is controlled by the proportional control valves 60a and 60b. Oil can be supplied and drained.
[0050]
Similarly, in addition to the hydraulic oil from the first hydraulic pump 51 of the first circuit section 55, the second circuit Hydraulic oil from the second hydraulic pump 52 of the section 56 is also supplied to the boom drive hydraulic cylinder 105.
For this reason, the first boom control valve 59 is interposed in the oil passage 61 of the first circuit portion 55, and the second boom control valve 65 is interposed in the oil passage 66 of the second circuit portion 56. By controlling the first boom control valve 59 by the proportional control valves 59a and 59b and controlling the second boom control valve 65 by the proportional control valves 65a and 65b, the operation of the boom drive hydraulic cylinder 105 is performed. Oil can be supplied and drained.
[0051]
In the present embodiment, the stick regeneration valve 76 is interposed in the oil passages 67 and 68 for supplying and discharging hydraulic oil to and from the hydraulic cylinder 106 for driving the stick. A predetermined amount of hydraulic oil can be regenerated to the supply-side oil passage.
Similarly, boom regeneration valves 77 are also interposed in oil passages 78 and 79 for supplying and discharging hydraulic oil to and from the hydraulic cylinder 105 for boom drive. A predetermined amount of hydraulic oil can be regenerated.
[0052]
Here, as shown in FIG. 3, each of the control valves 57 to 60 and 62 to 65 is configured as a spool valve, and each is configured to include a plurality (here, five) of throttles. That is, as shown in FIG. 3, each of the control valves 57 to 60 and 62 to 65 is provided with an oil passage (operating oil supply passage) for communicating the first hydraulic pump 51, the second hydraulic pump 52 and the stick driving hydraulic cylinder 106. , PC passage) 61a, 66a, an oil passage (operating oil discharge passage, CT passage) 66b for connecting the PC throttle 8 interposed between the stick driving hydraulic cylinder 106 and the reservoir tank 70. The CT throttle 9 interposed in 69, and the bypass passage throttle 10 interposed in the oil passages (bypass passages) 61b and 66c communicating the first hydraulic pump 51, the second hydraulic pump 52 and the reservoir tank 70. And is provided.
[0053]
In FIG. 3, the stick control valves 60 and 64 are in the stick lowered position. However, the stick control valves 60 and 64 are moved upward in FIG. By interposing the bypass passage restrictor 10 in the bypass passages 61b and 66c, the stick control valves 60 and 64 can be set to the neutral position, and the stick control valves 60 and 64 are set at the uppermost position in FIG. In the direction, the PC throttles 8 of the stick control valves 60 and 64 are interposed in the PC passages 61a and 66a, and the CT throttles 9 of the stick control valves 60 and 64 are changed to the CT throttles. By interposing the passages 66b and 69, the stick control valves 60 and 64 can be set to the stick raising position.
[0054]
In setting the diameters of the apertures 8, 9, and 10, in order to secure the interlocking of the working devices 118 such as the boom 103 and the stick 104, all the working devices 118 are operated when each operating member 54 is fully operated. Is considered to move.
The opening areas of the oil passages 61a and 66a that connect the first hydraulic pump 51 and the second hydraulic pump 52 with the stick driving hydraulic cylinder 106 (opening area of the hydraulic oil supply passage, P− C opening area) is adjusted.
[0055]
The CT throttle 9 adjusts the opening area of the oil passages 66b and 69 (the opening area of the hydraulic oil discharge passage and the CT opening area) that communicate the stick driving hydraulic cylinder 106 and the reservoir tank 70.
The opening area of the oil passages 61b and 66c (the opening area of the bypass passage) that connects the first hydraulic pump 51 and the second hydraulic pump 52 to the reservoir tank 70 is adjusted by the bypass passage restrictor 10.
[0056]
By the way, in this embodiment, as shown in FIG. 2, in order to control the control valves 57 to 60 and 62 to 65, the pilot pump 83 and the proportional pressure reducing valves 57a to 60a, 57b to 60b, 62a to 65a, A pilot hydraulic circuit including 62b to 65b is provided. In FIG. 2, only the pilot pump 83 and the proportional pressure reducing valves 57a to 60a, 57b to 60b, 62a to 65a, and 62b to 65b provided in the pilot hydraulic circuit are shown, and the pilot oil pressure is omitted by omitting the pilot oil passage. Indicated by P.
[0057]
Here, the proportional pressure reducing valves 57a to 60a, 57b to 60b, 62a to 65a, and 62b to 65b are electromagnetic valves, and are operated by an operation signal from the controller 1 described later. Thus, the pilot oil pressure from the pilot pump 83 is applied to the control valves 57 to 60 and 62 to 65 as a predetermined pressure based on the operation signal from the controller 1.
[0058]
With such a configuration, for example, in order to rotate the upper revolving unit 102, the turning operation member 54d in the driving operation room 101 is operated to turn the pilot oil pressure P from the pilot pump 83 through a pilot oil passage (not shown). By acting on the motor control valve 63, the swing motor control valve 63 is moved to a required position. Thus, the supply and discharge of hydraulic oil to and from the swing motor 110 are adjusted, whereby the swing motor 110 is operated.
[0059]
For example, to rotate the upper swing body 102 rightward, the swing motor 110 may be rotated clockwise. In this case, the pilot oil pressure is applied to the swing motor control valve 63 through the pilot oil passage. As a result, the turning motor control valve 63 is set to the right turning position, and the operating oil from the second hydraulic pump 52 of the second circuit portion 56 passes through the oil passages 66a and 96 to the right oil chamber of the turning motor 110. On the other hand, the hydraulic oil in the left oil chamber of the swing motor 110 is discharged to the reservoir tank 70 via the oil passages 97 and 66b. Thereby, the turning motor 110 is turned clockwise, and the upper turning body 102 turns right.
[0060]
Conversely, to rotate the upper swing body 102 to the left, the swing motor 110 may be rotated counterclockwise. In this case, the pilot oil pressure is applied to the swing motor control valve 63 through the pilot oil passage. As a result, the swing motor control valve 63 becomes the left swing position, and the hydraulic oil from the second hydraulic pump 52 of the second circuit section 56 is supplied to the left oil chamber of the swing motor 110 via the oil passages 66a and 97. Meanwhile, the operating oil in the right oil chamber of the swing motor 110 is discharged to the reservoir tank 70 via the oil passages 96 and 66b. As a result, the turning motor 110 is turned counterclockwise, and the upper turning body 102 turns left.
[0061]
Further, in order to maintain the current state of the upper swing body 102, the pilot hydraulic pressure is applied to the swing motor control valve 63 as appropriate, and the spool position of the swing motor control valve 63 is set to the neutral position (the hydraulic supply / discharge path cutoff position). ). Accordingly, the supply and discharge of hydraulic oil in each oil chamber of the swing motor 110 is stopped, and the upper swing body 102 is held at the current position.
[0062]
To operate the boom 103, for example, the boom operation member 54a in the operation room 101 is operated, and the pilot oil pressure P from the pilot pump 83 is passed through a pilot oil passage (not shown) to control the boom control valves 59 and 65. To move the boom control valves 59 and 65 to required positions. Thereby, the supply and discharge of the hydraulic oil of the boom drive hydraulic cylinder 105 is adjusted, and these cylinders 105 are driven to expand and contract to a required length, whereby the boom 103 is operated.
[0063]
For example, to rotate the boom 103 downward (boom down), the boom drive hydraulic cylinder 105 may be contracted. In this case, the pilot oil pressure is made to act on the first boom control valve 59 through the pilot oil passage. As a result, the spool position of the first boom control valve 59 becomes the boom lower rotation position (boom down position), and the hydraulic oil from the first hydraulic pump 51 of the first circuit portion 55 flows through the oil passages 95 and 79. , And is supplied to one chamber of the boom driving hydraulic cylinder 105 and supplied to one chamber of the boom driving hydraulic cylinder 105. On the other hand, the hydraulic oil in the other room of the boom drive hydraulic cylinder 105 is discharged to the reservoir tank 70 via the oil passages 78 and 69. As a result, the boom 103 is rotated downward as shown by the arrow b in FIG. 12 while the boom drive hydraulic cylinder 105 contracts.
[0064]
Conversely, to rotate the boom 103 upward (boom up), the boom drive hydraulic cylinder 105 may be extended. In this case, the pilot oil pressure is caused to act on the first boom control valve 59 and the second boom control valve 65 through the pilot oil passage. Thereby, the spool position of the first boom control valve 59 and the second boom control valve 65 becomes the boom upper rotation position (boom up position), and the operation of the first circuit portion 55 from the first hydraulic pump 51. The oil is supplied to one chamber of the boom driving hydraulic cylinder 105 via oil passages 95 and 78, and the hydraulic oil from the second hydraulic pump 52 of the second circuit portion 56 is supplied via oil passages 66a, 90 and 78. Is supplied to the other chamber of the hydraulic cylinder 105 for boom drive. On the other hand, the hydraulic oil in one room of the boom drive hydraulic cylinder 105 is discharged to the reservoir tank 70 via the oil passages 79, 91, 66b or the oil passages 79, 69. Thereby, the boom 103 is rotated upward as shown by an arrow a in FIG. 12 while the boom drive hydraulic cylinder 105 is extended.
[0065]
Further, in order to maintain the current state of the boom drive hydraulic cylinder 105, the pilot hydraulic pressure is applied to the first boom control valve 59 and the second boom control valve 65 as appropriate, and the first boom control valve 59, the second The position of each spool of the 2-boom control valve 65 may be set to the neutral position (the hydraulic supply / discharge path shutoff position). Thus, the supply and discharge of hydraulic oil in each oil chamber of the boom drive hydraulic cylinder 105 is stopped, and the boom 103 is held at the current position.
[0066]
To operate the stick 104, for example, the operation member 54 in the operation room 101 is operated to apply the pilot oil pressure P from the pilot pump 83 to the stick control valves 60 and 64 through a pilot oil passage (not shown). Then, the stick control valves 60 and 64 are driven to required positions. Accordingly, the supply and discharge of the hydraulic oil of the stick driving hydraulic cylinder 106 is adjusted, and these cylinders 105 and 106 are driven to expand and contract to a required length, whereby the stick 104 is operated.
[0067]
For example, to rotate the stick 104 inward (stick-in), the stick driving hydraulic cylinder 106 may be extended. In this case, the pilot oil pressure is applied to the second stick control valve 60 through the pilot oil passage. As a result, the spool position of the second stick control valve 60 becomes the stick inner rotation position (stick-in position), and hydraulic oil from the first hydraulic pump 51 of the first circuit portion 55 flows through the oil passages 61 and 67. After that, it is supplied to one chamber of the stick driving hydraulic cylinder 106. On the other hand, hydraulic oil in the other chamber of the stick driving hydraulic cylinder 106 is discharged to the reservoir tank 70 through the oil passages 68 and 69. Accordingly, the stick 104 is rotated inward as indicated by an arrow d in FIG. 12 while the stick driving hydraulic cylinder 106 is extended.
[0068]
Conversely, to rotate the stick 104 outward (stick out), the stick driving hydraulic cylinder 106 may be contracted. In this case, the pilot oil pressure is applied to the second stick control valve 60 through the pilot oil passage. As a result, the spool position of the second stick control valve 60 becomes the stick outside rotation position (stick out position), and the operating oil from the first hydraulic pump 51 of the first circuit portion 55 flows through the oil passages 61 and 68. After that, it is supplied to another chamber of the stick driving hydraulic cylinder 106. On the other hand, hydraulic oil in one chamber of the stick driving hydraulic cylinder 106 is discharged to the reservoir tank 70 via the oil passages 67 and 69. Accordingly, the stick 104 is rotated outward as shown by an arrow c in FIG. 12 while the stick driving hydraulic cylinder 106 is contracted.
[0069]
Further, in order to maintain the current state of the stick driving hydraulic cylinder 106, the pilot hydraulic pressure is applied to the second stick control valve 60 as appropriate, and the position of each spool of the second stick control valve 60 is set to the neutral position (the hydraulic pressure). (Supply / discharge path cutoff position). Thus, the supply and discharge of hydraulic oil in each oil chamber of the stick driving hydraulic cylinder 106 is stopped, and the stick 104 is held at the current position.
[0070]
Further, for example, to operate the bucket 108, the bucket operating member 54c in the operation room 101 is operated to apply the pilot oil pressure P from the pilot pump 83 to the bucket control valve 58 through a pilot oil passage (not shown). Then, the bucket control valve 58 is moved to a required position. Thereby, the supply and discharge of the hydraulic oil of the bucket driving hydraulic cylinder 107 is adjusted, and these cylinders 107 are driven to extend and contract to a required length, whereby the bucket 108 is operated.
[0071]
For example, to rotate the bucket 108 inward (bucket-in), the bucket driving hydraulic cylinder 107 may be extended. In this case, the pilot oil pressure is applied to the bucket control valve 58 through the pilot oil passage. As a result, the spool position of the bucket control valve 58 becomes the bucket inner rotation position (bucket-in position), and the hydraulic oil from the first hydraulic pump 51 of the first circuit portion 55 passes through the oil passages 61 and 92, It is supplied to one chamber of the bucket driving hydraulic cylinder 107. On the other hand, hydraulic oil in the other chamber of the bucket driving hydraulic cylinder 107 is discharged to the reservoir tank 70 via the oil passages 93 and 69. As a result, the bucket driving hydraulic cylinder 107 is extended, and the bucket 108 is rotated inward as shown by an arrow f in FIG.
[0072]
Conversely, to rotate the bucket 108 outward (bucket open), the bucket driving hydraulic cylinder 107 may be contracted. In this case, the pilot oil pressure is applied to the bucket control valve 58 through the pilot oil passage. As a result, the spool position of the bucket control valve 58 becomes the bucket outside rotation position (bucket open position), and the hydraulic oil from the first hydraulic pump 51 of the first circuit portion 55 passes through the oil passages 94 and 93, The bucket driving hydraulic cylinder 107 is supplied to another chamber. On the other hand, the hydraulic oil in one chamber of the bucket driving hydraulic cylinder 107 is discharged to the reservoir tank 70 via the oil passages 92 and 69. As a result, the bucket driving hydraulic cylinder 107 is contracted while the bucket 108 is rotated outward as shown by an arrow e in FIG.
[0073]
Further, in order to maintain the current state of the bucket driving hydraulic cylinder 107, the pilot hydraulic pressure is applied to the bucket control valve 58 as appropriate, and the position of the spool of the bucket control valve 58 is set to the neutral position (the hydraulic supply / discharge path cutoff position). ). Thus, the supply and discharge of hydraulic oil in the oil chamber of the bucket driving hydraulic cylinder 107 is stopped, and the bucket 108 is held at the current position.
[0074]
By the way, various sensors are attached to the construction machine configured as described above, and a detection signal from each sensor is sent to a controller 1 described later.
For example, an engine speed sensor 71 is attached to the engine 50 that drives the hydraulic pumps 51 and 52, and a detection signal from the engine speed sensor 71 is sent to the controller 1 described later. The controller 1 performs feedback control so that the actual engine speed becomes the target engine speed set by the operator with the engine speed setting dial.
[0075]
Further, on the discharge side of the first hydraulic pump 51 of the first circuit unit 55 and the second hydraulic pump 52 of the second circuit unit 56, pressure sensors (P / S-P1) 72, A pressure sensor (P / S-P2) 73 is provided, and detection signals from these pressure sensors 72, 73 are sent to the controller 1 described later.
[0076]
Further, pressure sensors (P / S-N1) are provided downstream of the control valves 57 to 60 of the oil passage 61 of the first circuit portion 55 and the control valves 62 to 65 of the oil passage 66 of the second circuit portion 56, respectively. ) 74 and a pressure sensor (P / S-N2) 75 are provided, and detection signals from these pressure sensors 74 and 75 are sent to the controller 1 described later.
[0077]
A pressure sensor (P / S-BMd) 80 is provided in an oil passage for supplying and discharging hydraulic oil to and from the boom drive hydraulic cylinder 105, that is, on the rod side pressure (load pressure) of the boom drive hydraulic cylinder 105. The detection signal from the pressure sensor 80 is sent to the controller 1 described later.
In the present embodiment, the controller 1 is provided to control the construction machine configured as described above.
[0078]
The controller 1 controls the first hydraulic pump 51, the second hydraulic pump 52, the regeneration valves 76, 77, and the control valves based on the detection signals from the sensors 71 to 75 and 80 and the electric signals from the operation member 54. By outputting operation signals to the valves 57 to 60 and 62 to 65, the tilt angle control of the first hydraulic pump 51 and the second hydraulic pump 52, the position control of each control valve 57 to 60, 62 to 65, and each regeneration The position of the valves 76 and 77 is controlled.
[0079]
Of these, the tilt angle control of the first hydraulic pump 51 and the second hydraulic pump 52 by the controller 1 is performed on the downstream side of the bypass passage 61b of the first circuit portion 55 and the downstream side of the bypass passage 66c of the second circuit portion 56. Negative flow control is performed based on detection signals from the pressure sensors 74 and 75 provided. Since the negative flow control is performed based on the pressures detected by the pressure sensors 74 and 75, the pressure detected by the pressure sensors 74 and 75 is also referred to as a negative control pressure.
[0080]
Here, the negative flow control (electronic negative flow control system) refers to a pump flow control having negative characteristics such that the pump discharge flow rate is reduced when the pressure on the downstream side of the bypass passages 61b and 66c increases.
Here, the pump is controlled by controlling the operation amount of each operation member 54, that is, the flow rate control in which the pump discharge flow rate is controlled according to the negative control pressure, and the load pressure applied to the actuator, that is, the pump discharge flow rate in accordance with the pump discharge pressure. Controlled horsepower control is divided into.
[0081]
Among them, the flow rate control can control the speed of the actuator (each cylinder) within the allowable horsepower. That is, the pump discharge flow rate can be controlled in accordance with the operation amount of each operation member 54, that is, the negative control pressure, and thereby the speed of the actuator can be controlled.
By the way, when each operation member 54 is fully operated and the pump discharge flow rate is maximum and the actuator speed is maximum, the pump discharge flow rate (that is, the actuator speed) is determined by the following equation.
[0082]
Pump discharge flow Q = allowable horsepower W / pump discharge pressure P
In this state, if the load pressure applied to the actuator fluctuates, the pump discharge pressure P also fluctuates, and the pump discharge flow rate Q also fluctuates according to the above equation, so that the actuator speed also fluctuates.
As described above, the pump discharge flow rate Q is not controlled according to the operation amount of each operation member 54, but is controlled according to the load pressure applied to the actuator, that is, the pump discharge pressure P. Is called horsepower control in a state where the control depends on the allowable horsepower W of the engine 50 that drives the first hydraulic pump 51 and the second hydraulic pump 52.
[0083]
When such horsepower control is performed, the actual speed of the actuator is determined by the magnitude of the load pressure even if the operator fully operates each operating member 54 and requests the maximum speed of the actuator. In this case, the horsepower of the engine 50 becomes the maximum allowable value.
Further, for example, when a plurality of actuators are simultaneously operated, even if each operation member 54 is not fully operated, the hydraulic oil is supplied to each actuator, the negative control pressure decreases, and the required flow rate decreases. When the flow rate exceeds the allowable flow rate determined by the allowable horsepower, the pump tilt angle control is performed so as to achieve the allowable flow rate in the horsepower control.
[0084]
By the way, when the operating member 54 is in the neutral position, that is, when the operator is not operating the operating member 54, the working device 118 does not work at all and it is not necessary to drive the actuator. The pump discharge flow rate is desirably set to zero.
For this reason, in the present embodiment, the control valves 57 to 60 and 62 to 65 are open centers (arranged so that the bypass passages 61b and 66c are open at the spool neutral position), and the operation member 54 is neutral. In the position, the hydraulic oil supplied from the hydraulic pumps 51 and 52 returns to the reservoir tank 70 through the bypass passages 61b and 66c.
[0085]
Accordingly, when the operation member 54 is in the neutral position, the pressure immediately upstream of the throttles 81 and 82 disposed downstream of the bypass passages 61b and 66c increases, and the variable displacement hydraulic pump 51 is controlled by the negative flow control. , 52 are controlled so as to reduce the pump discharge flow rate.
On the other hand, when the operation member 54 is operated, an amount of hydraulic oil corresponding to the operation amount is supplied to each actuator (cylinder or the like), and the remaining hydraulic oil returns to the reservoir tank 70 through the bypass passages 61b and 66c. It has become.
[0086]
The throttles (orifices) 81 and 82 are provided downstream of the bypass passages 61b and 66c as described above. Pressure sensors 74 and 75 are interposed in the bypass passages 61b and 66c immediately upstream of the throttles 81 and 82, and the pressures immediately upstream of the throttles 81 and 82 detected by the pressure sensors 74 and 75 are detected. The tilt angle control of the hydraulic pumps 51 and 52 is performed based on the above.
[0087]
When the operator operates the operation member 54, the control valves 57 to 60 and 62 to 65 move according to the operation amounts of the operation member 54, the bypass passages 61b and 66c are throttled, and the operation flowing through the bypass passages 61b and 66c. Although the flow rate of the oil decreases, the diameters of the throttles 81 and 82 are constant, so that the pressure immediately upstream of the throttles 81 and 82, that is, the pressures detected by the pressure sensors 74 and 75, decreases by the reduced flow rate. Then, the tilt angle control of the variable displacement hydraulic pumps 51 and 52 is performed so that the pump discharge flow rate increases in accordance with the reduced pressure.
[0088]
This means that the pump discharge flow rate is controlled to increase according to the operator's request, that is, the amount of operation of the operation member 54 by the operator. , 52 means that the speed of the actuator (each cylinder) can be controlled.
[0089]
In the present embodiment, the position control of the control valves 57 to 60 and 62 to 65 by the controller 1 is performed in addition to the position control of the control valves 57 to 60 and 62 to 65 according to the operation of the operation member 54 by the operator. The position of each of the control valves 57 to 60 and 62 to 65 is also controlled in accordance with the engine speed.
That is, the controller 1 adjusts the pilot oil pressure applied to each of the control valves 57 to 60 and 62 to 65 based on the electric signal from the operation member 54 and controls the proportional pressure reducing valves (pilot pressure control valves) 57 a to 60 a and 57 b to An operation signal is output in order to control the operation of 60b, 62a to 65a, and 62b to 65b.
[0090]
Further, the controller 1 sends control signals to the control valves 57 to 60 and 62 to 65 based on a detection signal from an engine speed sensor 71 attached to the engine 50 that drives the first hydraulic pump 51 and the second hydraulic pump 52. An operation signal is output to control the operation of proportional pressure reducing valves (pilot pressure control valves) 57a to 60a, 57b to 60b, 62a to 65a, and 62b to 65b for adjusting the pilot oil pressure to be applied.
[0091]
The proportional pressure reducing valves 57a to 60a, 57b to 60b, 62a to 65a, 62b to 65b are operated based on such an operation signal, whereby the pressure of the pilot hydraulic pressure supplied from the pilot pump 83 is adjusted. The spool stroke amount (spool movement amount) of each of the control valves 57 to 60 and 62 to 65 is adjusted.
[0092]
The control device for a construction machine according to the present embodiment is configured as described above, and various controls are performed by the controller 1. Further, in the present embodiment, a pump flow rate control (basic of a hydraulic pump) in a normal negative flow control is performed. In addition to the tilt angle control), the plurality of hydraulic pumps 51 and 52 are controlled based on electric signals from the plurality of operating members 54 so that the engine output from the engine can be optimally distributed to each of the plurality of hydraulic pumps 51 and 52. Each pump horsepower control (pump tilt angle control) is performed. Note that the engine output includes engine power, engine torque, and engine horsepower output from the engine.
[0093]
By the way, for example, under the condition that the engine horsepower (pump horsepower) is constant at a fixed value, as shown by a solid line A in FIG. 4, if the load pressure applied to the working machine is low, the flow rate of the hydraulic oil discharged from the hydraulic pump becomes Although it increases (pump flow rate = horsepower (constant) / load pressure), when the flow rate of the hydraulic oil discharged from the hydraulic pump increases, the pressure loss of the piping system increases as shown by the hatched area in FIG. Since the horsepower loss due to the pipe pressure loss increases, the effective horsepower (effective operating oil pressure, indicated by arrow C in FIG. 4) of the engine horsepower (pump horsepower) that can be supplied to the hydraulic actuator decreases, and the solid line in FIG. A becomes as shown by the solid line B, and a sufficient flow rate of hydraulic oil necessary for the work cannot be obtained, and a sufficient output (power) cannot be obtained.
[0094]
In addition, the horsepower loss due to the pipe pressure loss becomes heat and raises the temperature of the hydraulic oil, and due to this temperature rise, the viscosity of the hydraulic oil decreases and the internal leak of hydraulic equipment increases, and the hydraulic system Efficiency (efficiency of supplying hydraulic oil to the hydraulic actuator) is deteriorated, and sufficient work speed is not obtained, resulting in work efficiency being deteriorated.
On the other hand, in a region where the load pressure is high and the pump flow rate is small, the horsepower loss due to the pipe pressure loss is reduced, so that the effective horsepower of the engine horsepower (pump horsepower) that can be supplied to the hydraulic actuator increases.
[0095]
For this reason, in the present embodiment, in consideration of the efficiency of the entire hydraulic system, the engine horsepower (pump horsepower) is reduced in the low load pressure / large flow rate region in which the horsepower loss due to the pipe pressure loss is large, in conjunction with the load pressure. The engine horsepower (pump horsepower) is set to be large in a high load pressure / small flow rate region where horsepower loss due to pipe pressure loss is small.
[0096]
When the pump horsepower is set small, the effective horsepower that can be supplied to the hydraulic actuator also decreases in proportion to this, but in this case, the horsepower loss due to the pipe pressure loss acts as heat to raise the temperature of the hydraulic oil. By doing so, it is possible to reduce the secondary inconvenience that the internal leak of the hydraulic equipment increases, and in the balance evaluation with this, the efficiency of the entire system can be improved.
[0097]
Further, for example, when performing control for variably setting the engine horsepower (pump horsepower) according to the load pressure applied to the work implement, the engine horsepower (pump horsepower) is uniformly determined according to the load pressure regardless of the type of work. Is set to be small, the work efficiency will be reduced depending on the type of work. For example, if the engine horsepower (pump horsepower) is set to be small in accordance with the load pressure applied to the work machine at the time of the boom up, a problem that the cycle time becomes long occurs. Therefore, when the boom is raised, it is necessary to use the full horsepower of the engine horsepower as the pump horsepower of each hydraulic pump in the full load pressure range.
[0098]
Also, when performing control to variably set horsepower distribution (horsepower distribution of engine horsepower) among a plurality of hydraulic pumps, if horsepower is uniformly distributed regardless of a combination of a plurality of hydraulic actuators to be operated. However, depending on the combination of a plurality of hydraulic actuators, optimum horsepower distribution is not always performed, and the engine output may not be used efficiently. In such a case, the distribution ratio of the horsepower distribution among the plurality of hydraulic pumps may be changed.
[0099]
For this reason, in this embodiment, based on the operation signal (electric signal) from each operation member 54, each control is selectively used according to the kind of work.
Next, a description will be given of pump tilt angle control (horsepower control) performed by distributing the engine output to each of the plurality of hydraulic pumps 51 and 52, which is a feature of the construction machine control device according to the present embodiment.
[0100]
Here, FIG. 1 is a control block diagram for explaining pump tilt angle control by the control device of the construction machine according to the present embodiment.
In the present embodiment, as shown in FIG. 1, the controller 1 includes a low power / high power determination unit 2, a digging determination unit 3, an excavation determination unit 4, a lift / turn determination unit 5, and a pump tilt angle control unit. 6 is provided.
[0101]
Among these, the low power / high power determination means 2 determines whether the power should be low power or high power according to the work load applied to the working device 118, and determines the determination result based on the pump tilt angle control means described later. 6 to the digging control unit 6B and the excavation control unit 6C. As a result, it is possible to automatically determine whether to use low power or high power in accordance with the workload. Therefore, an electric signal corresponding to the pump discharge pressure detected by the pressure sensors 72 and 73 is input to the low power / high power determination means 2.
[0102]
The reason why the judgment result by the low-power / high-power judgment means 2 is not output to the lift / turn judgment means 5 is that it involves a boom-up operation during the lift / turn operation, and is always high in the case of the boom-up operation. It requires power. Specifically, the low power / high power determination unit 2 determines that one of the pump discharge pressures detected by the pressure sensors 72 and 73 is a predetermined pressure (for example, 200 kgf / cm). ² About 19.6 MPa) or more, and determines whether the pump discharge pressure is a predetermined pressure (for example, 200 kgf / cm). ² If it is higher than about 19.6 MPa, it is determined that the power should be high, while the pump discharge pressure is a predetermined pressure (for example, about 200 kgf / cm ² If not more than about 19.6 MPa), it is determined that the power should be low.
[0103]
Here, since the pump discharge pressure changes according to the work load applied to the work device 118 such as the boom 103, the pump discharge pressure becomes a predetermined pressure (for example, about 200 kgf / cm). ² By determining whether the pressure is equal to or more than about 19.6 MPa), it is determined whether the work load on the work device 118 such as the boom 103 is large (or small).
[0104]
Here, the pump discharge pressure is a predetermined pressure (for example, 200 kgf / cm ² It is determined whether the engine 50 should be set to low power or high power depending on whether the pressure is equal to or more than about 19.6 MPa). A determination may be made as to whether the discharge pressure is equal to or higher than one of a plurality of predetermined pressures, and the engine output may be controlled in a plurality of stages. Further, both of the pump discharge pressures detected by the pressure sensors 72 and 73 are equal to a predetermined pressure (for example, 200 kgf / cm). ² About 19.6 MPa) or more, and the average value of the pump discharge pressure detected by the pressure sensors 72 and 73 is a predetermined pressure (for example, 200 kgf / cm). ² It may be configured to judge whether it is about 19.6 MPa or more. The magnitude of the predetermined pressure is determined based on whether the power needs to be increased in consideration of the feeling (operation speed) of the operator. The digging determining means 3 determines whether or not the digging operation is performed based on the electric signals from the stick operating member 54b and the bucket operating member 54c, and determines the result of this determination by the pump tilt angle control means 6 described later. This is output to the digging control section 6B.
[0105]
The digging determination means 3 performs digging when the stick-in operation is performed and the bucket operation member 54c is operated based on the electric signals from the stick operation member 54b and the bucket operation member 54c. It is determined that it is work.
Here, the digging work is a work in which the stick-in operation and the bucket operation are performed at the same time. For example, a digging work performed with high power (heavy digging work), a leveling work or digging work performed with low power (Light excavation work).
[0106]
The excavation determining means 4 determines whether or not an excavation operation is to be performed based on electric signals from the stick operating member 54b and the turning operating member 54d, and determines the result of this determination as a pump tilt angle described later. This is output to the excavation control unit 6C of the control means 6.
In the excavation determining means 4, the stick-in operation is performed based on the electric signals from the stick operation member 54b and the turning operation member 54d, and the turning operation member 54d is operated. Is determined to be an excavation work.
[0107]
Here, the excavation work is a work in which the stick-in operation and the turning operation are performed simultaneously. The excavation work includes a work performed with low power and a work performed with high power. Note that the low power refers to a case where the load pressure applied to the stick driving hydraulic cylinder 106 is low, and thus the pump discharge pressure is lower than a predetermined value. On the other hand, high power refers to a case where the load pressure applied to the stick driving hydraulic cylinder 106 is high, and therefore the pump discharge pressure becomes higher than a predetermined value.
[0108]
For example, as an operation to be performed with low power, there is a diagonal leveling operation in which a stick operation and a turning operation are interlocked, and the turning operation is an operation pattern in which a full operation is not performed.
Here, the diagonal leveling operation is a leveling operation in which the bucket blade is lightly inserted into the ground, and the upper revolving unit 102 is turned to press the work implement against the side wall, and the operation amount of the operating member is reduced. This is performed while the upper swing body 102 is swung accordingly. In this oblique leveling operation, since the reaction force is small, and hence the body is less rattled, the operation can be performed at the modulation position in both the X-axis direction and the Y-axis direction. In this regard, it can be distinguished from a side wall excavation operation.
[0109]
Further, as a work performed with high power, there is a side wall scraping operation (side wall excavation operation, side wall cutting operation) in which a stick-in operation is performed while a work machine is pressed against the side wall by a turning operation.
Here, in the side wall scraping operation, the turning operation member 54d is fixed in a fully operated state (in this case, since the working machine hits the side wall, the upper turning body 102 does not actually turn, but It is performed by performing a stick-in by a modulation operation. In this operation, the turning operation member 54d and the stick operation member 54b are constituted by a single operation lever, and when the operation lever is operated in the X-axis direction, the operation becomes a turning operation, and when the operation lever is operated in the Y-axis direction, the operation is performed. Under these conditions, the operation in the X-axis direction and the operation in the Y-axis direction are performed due to the stick operation and the body rattling due to the excavation reaction force in the side wall scraping operation. However, it is difficult to fix it at the modulation position.
[0110]
The lift / swing determination means 5 determines whether or not a lifting / swing operation is performed based on electric signals from the boom operation member 54a and the swing operation member 54d, and determines the result of this determination as a pump tilt angle described later. This is output to the lift / turn controller 6D of the control means 6.
In the lift / turn determination unit 5, the boom-up operation is performed based on the electric signals from the boom operation member 54a and the turn operation member 54d, and the turn operation member 54d is operated. Is determined to be a lift / turn operation.
[0111]
Here, the lift / turn operation is an operation in which a boom-up operation and a turn operation are performed simultaneously, and is performed as one operation in a loading operation for loading earth and sand into a dump truck or the like.
The pump tilt angle control means 6 includes a basic tilt angle control unit 6A, a digging control unit 6B, an excavation control unit 6C, and a lift / turn control unit 6D. , 52 to output an operation signal to the hydraulic pumps 51, 52 to perform the tilt angle control.
[0112]
In the present embodiment, the pump tilt angles of the hydraulic pumps 51 and 52 are basically set by the basic tilt angle control unit 6A. The pump tilt angles of the hydraulic pumps 51 and 52 are controlled so that the engine output is optimally distributed.
The basic tilt angle control unit 6A performs basic pump tilt angle control of the hydraulic pumps 51 and 52 based on the detection information from the pressure sensors 72, 73, 74 and 75.
[0113]
Here, the pump tilt angle control in the negative flow control by the basic tilt angle control unit 6A will be described.
That is, the basic tilt angle control unit 6A outputs the operating oil pressure (negative control pressure) P detected by the pressure sensors 74 and 75. _N1 , P _N2 And read the negative control pressure P _N And required flow Q _N The negative control pressure P read from the map as shown in FIG. _N1 , P _N2 Required flow Q corresponding to _N1 , Q _N2 (Specifically, the required flow rate Q _N1 , Q _N2 Tilt angle V corresponding to _N1 , V _N2 ) Is set. The required flow rate refers to a flow rate required in negative flow control. In FIG. 5, the negative control pressure P _N1 Required flow Q corresponding to _N1 (Specifically, the required flow rate Q _N1 , The pump tilt angle V corresponding to _N1 ) Only.
[0114]
On the other hand, the basic tilt angle control unit 6A outputs the pump discharge pressure P detected by the pressure sensors 72 and 73. _P1 , P _P2 And read the pump discharge pressure P _P And allowable flow rate Q _P The pump discharge pressure P read from the map as shown in FIG. _P1 , P _P2 Flow rate Q corresponding to _P1 , Q _P2 (Specifically, the allowable flow rate Q _P1 , Q _P2 Tilt angle V corresponding to _P1 , V _P2 ) Is set. Note that the allowable flow rate is a pump discharge flow rate according to the allowable horsepower of the engine 50 that drives the first hydraulic pump 51 and the second hydraulic pump 52. In FIG. 6, the pump discharge pressure P _P1 Flow rate Q corresponding to _P1 (Specifically, the allowable flow rate Q _P1 Tilt angle V corresponding to _P1 ) Only.
[0115]
Then, the basic tilt angle control unit 6A determines the required flow rate Q _N1 , Q _N2 And allowable flow rate Q _P1 , Q _P2 And the smaller pump flow rate (required flow rate Q _N1 , Q _N2 Or allowable flow rate Q _P1 , Q _P2 ) So that the pump tilt angle (pump tilt angle V _N1 , V _N2 Or pump tilt angle V _P1 , V _P2 ) Is set, and this is output to the first hydraulic pump 51 and the second hydraulic pump 52 as a tilt angle control signal.
[0116]
Next, the basic operation of the pump tilt angle control in the negative flow control by the basic tilt angle control unit 6A will be described with reference to the flowchart of FIG.
That is, first, in step S10, the negative control pressure P _N1 , P _N2 And at step S20 the pump discharge pressure P _P1 , P _P2 Read.
[0117]
Next, in step S30, the negative control pressure P read in step S10. _N1 , P _N2 Required flow Q corresponding to _N1 , Q _N2 Is calculated from the map of FIG. 5 and the pump discharge pressure P read in step S20 in step 40 _P1 , P _P2 Flow rate Q corresponding to _P1 , Q _P2 Is calculated from the map of FIG.
Then, in step S50, the required flow rate Q _N1 , Q _N2 Is the allowable flow rate Q _P1 , Q _P2 It is determined whether the flow rate is smaller than the required flow rate Q. _N1 , Q _N2 Is the allowable flow rate Q _P1 , Q _P2 If it is determined that the required flow rate Q is smaller than _N1 , Q _N2 Is set as the pump flow rate, and the routine returns. As a result, the tilt angle of the first hydraulic pump 51 and the second hydraulic pump 52 becomes smaller than the required flow rate Q. _N1 , Q _N2 Is set so as to have a tilt angle corresponding to.
[0118]
On the other hand, the required flow Q _N1 , Q _N2 Is the allowable flow rate Q _P1 , Q _P2 If it is determined that the flow rate is equal to or greater than the above, the process proceeds to step S70, where the allowable flow rate Q _P1 , Q _P2 Is set as the pump flow rate, and the routine returns. As a result, the tilt angle of the first hydraulic pump 51 and the second hydraulic pump 52 becomes smaller than the allowable flow rate Q. _P1 , Q _P2 Is set so as to have a tilt angle corresponding to.
The digging control unit 6B controls the stick driving hydraulic cylinder 106 and the bucket driving hydraulic cylinder 107 when the digging determination unit 3 determines that digging is being performed, that is, when it is determined that the stick-in operation and the bucket operation are performed simultaneously. The distribution of the engine output to the hydraulic pumps 51 and 52 is set so that the hydraulic oil is supplied without excess and deficiency, and the pumps of the hydraulic pumps 51 and 52 are operated so that the hydraulic pumps 51 and 52 operate within this distribution. It controls the tilt angle. Note that the pump tilt angle control of each of the hydraulic pumps 51 and 52 is the same as that of the above-described basic tilt angle control unit 6A. As a result, the engine output can be optimally distributed to both of the hydraulic pumps 51 and 52, and the pump discharge flow rates of the first hydraulic pump 51 and the second hydraulic pump 52 simultaneously operate the stick 104 and the bucket 108. In addition to the pump discharge flow rate sufficient to make it possible, the fuel consumption can be improved by efficiently using the engine output.
[0119]
More specifically, the digging control unit 6B allocates the engine output from the engine 50 to the hydraulic pumps 51 and 52 based on the determination result from the low power / high power determination unit 2 as described later. The distribution horsepower is set, and the upper limit (upper limit horsepower) of the total horsepower of each of the hydraulic pumps 51 and 52 is set.
Here, if high power is to be set, the upper limit horsepower is set to the maximum horsepower of the engine (for example, about 140 PS; about 102.20 kW). On the other hand, when low power is to be set, the upper limit horsepower is set to a predetermined horsepower (for example, about 120 PS; about 87.60 kW) that is equal to or less than the maximum horsepower of the engine.
[0120]
In the digging control section 6B, the engine output distribution to the hydraulic pumps 51 and 52 is set based on an electric signal corresponding to the operation amount of the stick operation member 54b and the bucket operation member 54c. .
Here, Table 1 below shows an example of the distribution ratio of the engine output and an example of the setting of the upper limit horsepower. Table 1 shows the distribution ratio of the engine output when each operation member 54 is fully operated. Table 1 also shows the pump horsepower according to the distribution ratio of the engine output. The first hydraulic pump 51 mainly supplies hydraulic oil to the bucket driving hydraulic cylinder 107, and the second hydraulic pump 52 mainly supplies hydraulic oil to the stick driving hydraulic cylinder 106.
[0121]
[Table 1]

[0122]
As shown in Table 1, first, when low power is to be set, the engine output from the engine 50 is supplied to the first hydraulic pump 51 so as to supply the minimum engine output required to drive the bucket 108. A minimum required percentage (e.g., about 30%) is allocated, and a stick required percentage (e.g., about three hundred percent) greater than the bucket required percentage to provide the second hydraulic pump 52 with the engine output required to operate the stick 104 at a sufficient operating speed. 70%).
[0123]
That is, when low power is to be set, the upper limit value of the total horsepower distributed to each of the hydraulic pumps 51 and 52 is set to the low power upper limit horsepower (for example, about 120 PS; about 87.6 kW). This engine horsepower is distributed to a bucket drive request horsepower (for example, about 36 PS; about 26.28 kW) so as to supply a minimum engine horsepower required to drive the bucket 108 to the first hydraulic pump 51, To provide the pump 52 with the engine horsepower required to operate the stick 104 at a sufficient operating speed, a stick demand horsepower (eg, about 84 PS; about 61.32 kW) greater than the bucket demand horsepower will be allocated.
[0124]
On the other hand, when the power should be high, the engine output from the engine 50 is, as shown in Table 1 above, the engine output necessary for the first hydraulic pump 51 to operate the bucket 108 at a sufficient operation speed. A bucket request ratio (e.g., about 40%) allocated to supply and a stick request ratio greater than the bucket request ratio to provide the second hydraulic pump 52 with the engine output required to operate the stick 104 at a sufficient operating speed. (For example, about 60%).
[0125]
That is, when high power is to be set, the upper limit of the total horsepower distributed to each of the hydraulic pumps 51 and 52 is set to the high power upper limit horsepower (maximum horsepower of the engine; for example, about 140 PS; about 102.20 kW). This engine horsepower is distributed to the first hydraulic pump 51 to supply the engine horsepower required to operate the bucket 108 at a sufficient operating speed (for example, about 56 PS; about 40.88 kW). 2 In order to supply the hydraulic pump 52 with the engine horsepower required to operate the stick 104 at a sufficient operating speed, a stick request horsepower (for example, about 84 PS; about 61.32 kW) larger than the bucket request horsepower will be distributed. .
[0126]
Here, the engine horsepower distributed to the first hydraulic pump 51 is set to a predetermined horsepower (for example, about 56 PS; about 40.88 kW) because hydraulic oil is supplied to the bucket driving hydraulic cylinder 107 to drive the bucket 108. This is because the operation speed of the bucket 108 is ensured by driving the supplied first hydraulic pump 51 with a larger engine horsepower (high power) than at the time of low power, thereby improving work efficiency.
[0127]
As described above, in both the low power and high power cases, the engine output is largely distributed to the second hydraulic pump 52 because of the operation supplied from the second hydraulic pump 52 to the stick driving hydraulic cylinder 106. This is because, by increasing the flow rate of the oil and improving the operation speed of the stick 104 that most affects the work efficiency, the work efficiency is improved as a whole.
[0128]
Further, as described above, in the control for variably setting the engine horsepower (pump horsepower) according to the load pressure applied to the work implement, a case where the total horsepower of the plurality of hydraulic pumps 51 and 52 is set to be small. Even so, by performing control capable of variably setting the horsepower distribution, a large amount of horsepower is distributed to a hydraulic actuator (here, a stick driving hydraulic cylinder) to be preferentially operated (for example, the same as at the time of high horsepower setting). By distributing the horsepower), it is possible to improve the working efficiency of the hydraulic actuator that is to be preferentially operated.
[0129]
Further, as described above, the control for variably setting the engine horsepower (pump horsepower) in accordance with the load pressure applied to the work machine and the control for variably setting the horsepower distribution among the plurality of hydraulic pumps are performed by each operating member. By combining them based on an operation signal (electric signal) from, the efficiency (including productivity / heat loss) of the entire system can be improved.
[0130]
The distribution ratio (distribution horsepower) of the engine output when each operation member 54 is not fully operated is the distribution ratio (distribution horsepower) of the engine output when each operation member 54 is fully operated. What is necessary is just to set by correcting according to the operation amount of each operation member 54.
When the excavation determining unit 4 determines that the excavation is being performed, that is, when the stick-in operation and the turning operation are performed simultaneously, the excavation control unit 6C controls the stick driving hydraulic cylinder 106 and the turning motor. The distribution of the engine output to the hydraulic pumps 51 and 52 is set so that the hydraulic oil is supplied to the hydraulic pumps 110 and 110 without excess and deficiency, and the hydraulic pumps 51 and 52 are operated such that the hydraulic pumps 51 and 52 operate within this distribution. 52 is to control the pump tilt angle. Note that the pump tilt angle control of each of the hydraulic pumps 51 and 52 is the same as that of the above-described basic tilt angle control unit 6A.
[0131]
As a result, the engine output can be optimally distributed to both of the hydraulic pumps 51 and 52, and the pump discharge flow rate of each of the first hydraulic pump 51 and the second hydraulic pump 52 depends on the operation of the stick 104 and the upper swing body 102. And the pump discharge flow rate sufficient to simultaneously perform the turning of the engine, and the fuel efficiency can be improved by efficiently using the engine output.
[0132]
Specifically, the excavation control unit 6C distributes the engine output from the engine 50 to the hydraulic pumps 51 and 52 based on the determination result from the low power / high power determination unit 2 as described later. The ratio (distribution horsepower) is set, and the upper limit output (upper limit horsepower) of the total horsepower of each of the hydraulic pumps 51 and 52 is set. Note that the upper limit output of the total horsepower (upper limit horsepower) corresponds to the full output (full horsepower) of the engine output (engine horsepower).
[0133]
Here, if high power is to be set, the upper limit horsepower is set to the maximum horsepower of the engine (for example, about 140 PS; about 102.20 kW). On the other hand, when low power is to be set, the upper limit horsepower is set to a predetermined horsepower (for example, about 120 PS; about 87.60 kW) that is equal to or less than the maximum horsepower of the engine.
The excavation control unit 6C sets the engine output distribution to the hydraulic pumps 51 and 52 based on the electric signals corresponding to the operation amounts of the stick operation member 54b and the turning operation member 54d. I have.
[0134]
Here, Table 2 below shows an example of the distribution ratio of the engine output and an example of the setting of the upper limit horsepower. Table 2 shows the distribution ratio of the engine output when each operation member 54 is fully operated. Table 2 also shows the pump horsepower according to the distribution ratio of the engine output. Further, the first hydraulic pump 51 mainly supplies hydraulic oil to the stick driving hydraulic cylinder 106, and the second hydraulic pump 52 mainly supplies hydraulic oil to the turning motor 110.
[0135]
[Table 2]

[0136]
As shown in Table 2, for example, in the case of the leveling operation, the load pressure of the stick driving hydraulic cylinder 106 is low, and therefore the pump discharge pressure is smaller than a predetermined value. The output is distributed to the first hydraulic pump 51 to provide the required engine output to operate the stick 104 at a sufficient operating speed (for example, about 70%). A minimum turning ratio (for example, about 30%) is allocated to supply the minimum engine output required to turn the 102.
[0137]
At this time, the upper limit value of the total horsepower distributed to each of the hydraulic pumps 51 and 52 is set to the low power upper limit horsepower (for example, about 120 PS; about 87.60 kW). Then, the engine horsepower is distributed to the first hydraulic pump 51 to provide the engine horsepower required to operate the stick 104 at a sufficient operating speed (for example, about 84 PS; about 61.32 kW). The minimum required horsepower (for example, about 36 PS; about 26.28 kW) is distributed to supply the minimum hydraulic engine power required to swing the upper swing body 102 to the second hydraulic pump 52.
[0138]
On the other hand, in the case of the side wall scraping operation (sidewall excavation), the load pressure of the stick driving hydraulic cylinder 106 is high, and therefore, the pump discharge pressure is higher than a predetermined value. In order to supply the first hydraulic pump 51 with an engine output required to operate the stick 104 at a sufficient operating speed, a stick request ratio (for example, about 75%) is allocated. A minimum required turn ratio (for example, about 25%) is allocated to supply the minimum engine output required to turn the vehicle.
[0139]
At this time, the upper limit of the total horsepower distributed to each of the hydraulic pumps 51 and 52 is set to a high-power upper horsepower (maximum horsepower of the engine; for example, about 140 PS; about 102.20 kW). Then, this engine horsepower is distributed to the first hydraulic pump 51 so as to supply the engine horsepower necessary to operate the stick 104 at a sufficient operating speed (for example, about 104 PS; about 75.92 kW). The minimum required horsepower (for example, about 36 PS; about 26.28 kW) is distributed to supply the minimum hydraulic engine power required to swing the upper swing body 102 to the second hydraulic pump 52.
[0140]
Here, the engine horsepower distributed to the first hydraulic pump 51 is set to a predetermined horsepower (for example, about 104 PS; about 75.92 kW) because hydraulic oil is supplied to the stick driving hydraulic cylinder 106 to operate the stick 104. This is because the operation speed of the stick 104 is ensured by driving the supplied first hydraulic pump 51 with a larger engine horsepower (high power) than at the time of low power, thereby improving work efficiency.
[0141]
As described above, in both the low power and high power cases, the engine output is largely distributed to the first hydraulic pump 51 because of the hydraulic oil supplied from the first hydraulic pump 51 to the stick driving hydraulic cylinder 106. Is to increase the operation speed of the stick 104, which most affects the work efficiency, thereby improving the work efficiency as a whole.
[0142]
Further, as described above, in the control for variably setting the engine horsepower (pump horsepower) according to the load pressure applied to the work implement, a case where the total horsepower of the plurality of hydraulic pumps 51 and 52 is set to be small. Even so, by performing control capable of variably setting the horsepower distribution, the horsepower is distributed to a hydraulic actuator (in this case, a stick driving hydraulic cylinder) to be preferentially operated, so that the horsepower is preferentially operated. The working efficiency of the hydraulic actuator can be improved.
[0143]
Further, as described above, the control for variably setting the engine horsepower (pump horsepower) in accordance with the load pressure applied to the work machine and the control for variably setting the horsepower distribution among the plurality of hydraulic pumps are performed by each operating member. By combining them based on an operation signal (electric signal) from, the efficiency (including productivity / heat loss) of the entire system can be improved.
[0144]
The distribution ratio (distribution horsepower) of the engine output when each operation member 54 is not fully operated is the distribution ratio (distribution horsepower) of the engine output when each operation member 54 is fully operated. What is necessary is just to set by correcting according to the operation amount of each operation member 54.
The lift / turn control unit 6D provides the boom operation member 54a and the turn operation when the lift / turn determination unit 5 determines that the lift / turn is performed, that is, when the boom-up operation and the turn operation are performed simultaneously. Based on the electric signal corresponding to the operation amount of the member 54d, the distribution of the engine output to the hydraulic pumps 51 and 52 is adjusted so that the hydraulic oil is supplied to the boom drive hydraulic cylinder 105 and the swing motor 110 without excess or deficiency. The pump tilt angle of each of the hydraulic pumps 51 and 52 is controlled so as to be set and such an engine output distribution. Note that the pump tilt angle control of each of the hydraulic pumps 51 and 52 is the same as that of the above-described basic tilt angle control unit 6A.
[0145]
As a result, the engine output can be optimally distributed to both of the hydraulic pumps 51 and 52, and the pump discharge flow rate of each of the first hydraulic pump 51 and the second hydraulic pump 52 depends on the operation of the boom 103 and the upper swing body 102. And the pump discharge flow rate sufficient to simultaneously perform the turning of the engine, and the fuel efficiency can be improved by efficiently using the engine output.
[0146]
Specifically, the lift / turn controller 6D sets a distribution ratio (distribution horsepower) for distributing the engine output from the engine 50 to each of the hydraulic pumps 51 and 52 as described later, and The upper limit output of the total horsepower (upper limit horsepower) is set. Here, the upper limit horsepower is set to the maximum horsepower of the engine (for example, about 140 PS; about 102.20 kW).
[0147]
Further, the lift / turn control unit 6D sets the engine output distribution to the hydraulic pumps 51 and 52 based on an electric signal corresponding to the operation amount of the boom operation member 54a and the turn operation member 54d. I have.
Here, Table 3 below shows an example of the distribution ratio of the engine output. Table 3 shows the distribution ratio of the engine output when each operation member 54 is fully operated. Table 3 also shows the engine horsepower according to the distribution ratio of the engine output. Further, the first hydraulic pump 51 mainly supplies hydraulic oil to the boom driving hydraulic cylinder 105, and the second hydraulic pump 52 mainly supplies hydraulic oil to the turning motor 110.
[0148]
[Table 3]

[0149]
As shown in Table 3, the engine output from the engine 50 is a boom request ratio (for example, about 70%) to supply the first hydraulic pump 51 with the engine output necessary to operate the boom 103 at a sufficient operating speed. The minimum required rotation ratio (for example, about 30%) is allocated to supply the second hydraulic pump 52 with the minimum engine output required to rotate the upper rotating body 102.
[0150]
At this time, the upper limit value of the total horsepower distributed to each of the hydraulic pumps 51 and 52 is set to the upper limit horsepower (for example, about 140 PS; about 102.20 kW). This is because a boom-up operation always requires high power. Then, the engine horsepower is distributed to the first hydraulic pump 51 for supplying the engine horsepower required to operate the boom 103 at a sufficient operating speed (for example, about 98 PS; about 71.54 kW). The minimum required horsepower (for example, about 42 PS; about 30.66 kW) is allocated to supply the hydraulic pump 52 with the minimum engine horsepower required to swing the upper swing body 102.
[0151]
Further, the reason why the engine output is distributed to the first hydraulic pump 51 more is that the flow rate of the hydraulic oil supplied from the first hydraulic pump 51 to the boom driving hydraulic cylinder 105 is increased, and the operating speed of the boom 103 is reduced. It is for improving the work efficiency by improving.
The distribution ratio (distribution horsepower) of the engine output when each operation member 54 is not fully operated is the distribution ratio (distribution horsepower) of the engine output when each operation member 54 is fully operated. What is necessary is just to set by correcting according to the operation amount of each operation member 54.
[0152]
The control device for a construction machine according to the present embodiment is configured as described above, and the main routine according to the present control operates according to the procedure shown in the flowchart of FIG. First, in step S10, an electric signal from each operation member 54 is read, and the process proceeds to step S20.
In step S20, the digging determination unit 3, the excavation determination unit 4, and the lift / turn determination unit 5 determine whether or not the stick-in operation has been performed based on the electric signal from the stick operation member 54b. As a result of the determination, if the digging determination means 3 and the excavation determination means 4 determine that the stick-in operation has been performed, the process proceeds to step S30.
[0153]
In step S30, the low power / high power determination means 2 reads the detection information (equivalent to the pump discharge pressure) from the pressure sensors 72 and 73, and proceeds to step S40. In step S40, the low power / high power determination means 2 indicates that the pump discharge pressure detected by the pressure sensors 72 and 73 is a predetermined pressure (for example, 200 kgf / cm ² About 19.6 MPa) or more.
[0154]
As a result of this determination, the pump discharge pressure becomes a predetermined pressure (for example, 200 kgf / cm ² If it is determined that the pressure is about 19.6 MPa) or more, the process proceeds to step S50, in which the digging control unit 6B and the excavation control unit 6C of the pump tilt angle control unit 6 are distributed to the hydraulic pumps 51 and 52. The upper limit of the engine output is set to a high power upper limit horsepower (for example, about 140 PS; about 102.20 kW), and the predetermined horsepower is optimally distributed to the hydraulic pumps 51 and 52 to perform the pump tilt angle control. An optimum power distribution pump tilt angle control routine at the time of high power is executed. The optimal power distribution pump tilt angle control routine at the time of high power will be described later.
[0155]
On the other hand, in step S40, the pump discharge pressure becomes a predetermined pressure (for example, 200 kgf / cm ² If it is determined that the difference is not more than about 19.6 MPa), the process proceeds to step S60, and the digging control unit 6B and the excavation control unit 6C of the pump tilt angle control unit 6 are distributed to the hydraulic pumps 51 and 52. The upper limit of the engine output is set to the low power upper limit horsepower (for example, about 120 PS; about 87.60 kW), and the predetermined horsepower is distributed to the respective hydraulic pumps 51 and 52 with optimum power to perform pump tilt angle control. An optimal power distribution pump tilt angle control routine at the time of power is executed. The optimum power distribution pump tilt angle control routine at the time of low power will be described later.
[0156]
If it is determined in step S20 that the stick-in operation has not been performed, the process proceeds to step S70 to execute an optimal power distribution pump tilt angle control routine during lift / turn. The optimal power distribution pump tilt angle control routine during lift / turn will be described later.
Next, in the control device of the construction machine according to the present embodiment, the optimal power distribution pump tilt angle control routine (step S50 in FIG. 8) at the time of high power operates according to the procedure shown in the flowchart of FIG.
[0157]
That is, in step A10, the digging determination unit 3 and the excavation determination unit 4 determine whether or not the bucket operation has been performed based on the electric signal from the bucket operation member 54c.
As a result of the determination, when the digging determination means 3 determines that the bucket operation has been performed, it means that the stick-in operation and the bucket operation have been performed at the same time, and this is considered to be a digging operation. The digging control unit 6B of the pump tilt angle control means 6 controls the engine output from the engine 50 based on the electric signals from the stick operating member 54b and the bucket operating member 54c so that the engine output from the engine 50 is optimally distributed. The distribution of the engine output to the hydraulic pumps 51 and 52 is set.
[0158]
Here, the digging control unit 6B distributes the engine output to the first hydraulic pump 51 by a bucket request ratio (for example, about 40%) and distributes the engine output to the second hydraulic pump 52 by a stick request ratio (for example, about 60%). That is, the digging control unit 6B transmits the engine horsepower whose upper limit value is set to the high power upper limit horsepower (for example, about 140 PS; about 102.20 kW) to the first hydraulic pump 51 for the bucket required horsepower (for example, about 56 PS; 88 kW) and the required stick horsepower (for example, about 84 PS; about 61.32 kW) to the second hydraulic pump 52.
[0159]
Then, the pump tilt angles of the hydraulic pumps 51 and 52 are controlled such that the engine output is distributed, and the process returns.
On the other hand, when the excavation determination means 4 determines that the bucket operation has not been performed in step A10, the process proceeds to step A20, and the excavation determination means 4 further performs the operation based on the electric signal from the turning operation member 54d. It is determined whether or not the turning operation has been performed.
[0160]
As a result of this determination, when the excavation determination means 4 determines that the turning operation has been performed, it means that the stick-in operation and the turning operation have been performed simultaneously, and this is considered to be an excavation operation. Therefore, the process of step A30 is performed.
Next, in step A30, the excavation control unit 6C controls the hydraulic pumps 51 so that the engine output from the engine 50 is optimally distributed based on the electric signals from the stick operation member 54b and the turning operation member 54d. , 52 are set.
[0161]
Here, the excavation control unit 6C distributes the engine output to the first hydraulic pump 51 with a stick request ratio (for example, about 75%) and distributes the engine output to the second hydraulic pump 52 with a minimum turning ratio (for example, about 25%). . That is, the excavation control unit 6C transmits the engine horsepower whose upper limit value is set to the high power upper limit horsepower (for example, about 140 PS; about 102.20 kW) to the first hydraulic pump 51 as the stick required horsepower (for example, about 104 PS, about 104 PS, about 102 PS). 75.92 kW) and the minimum required turning horsepower (for example, about 36 PS; about 26.28 kW) to the second hydraulic pump 52.
[0162]
Then, the pump tilt angles of the hydraulic pumps 51 and 52 are controlled such that the engine output is distributed, and the process returns.
By the way, if the excavation determination means 4 determines in step A20 that the turning operation has not been performed, it is considered that the operation is not an excavation operation, and therefore the pump tilt angle control during the excavation is not performed. And return.
[0163]
Next, the control device of the construction machine according to the present embodiment operates as shown in the flowchart of FIG. 10 in order to perform the optimal power distribution pump tilt angle control routine (step S60 in FIG. 8) at the time of low power.
That is, in step B10, the digging determination unit 3 and the excavation determination unit 4 determine whether or not the bucket operation has been performed based on the electric signal from the bucket operation member 54c.
[0164]
As a result of the determination, when the digging determination means 3 determines that the bucket operation has been performed, it means that the stick-in operation and the bucket operation have been performed at the same time, and this is considered to be a digging operation. The digging control unit 6B of the pump tilt angle control means 6 controls the engine output from the engine 50 based on the electric signals from the stick operating member 54b and the bucket operating member 54c so that the engine output from the engine 50 is optimally distributed. The distribution of the engine output to the hydraulic pumps 51 and 52 is set.
[0165]
Here, the digging control unit 6B distributes the engine output to the first hydraulic pump 51 with the minimum bucket request ratio (for example, about 30%), and distributes the engine output to the second hydraulic pump 52 with the stick request ratio (for example, about 70%). That is, the digging control unit 6B transmits the engine horsepower whose upper limit is set to the low power upper limit horsepower (for example, about 120 PS; about 87.60 kW) to the first hydraulic pump 51 for the minimum bucket horsepower (for example, about 36 PS; about 26 PS). .28 kW) and the required stick power (for example, about 84 PS; about 61.32 kW) to the second hydraulic pump 52.
[0166]
Then, the pump tilt angles of the hydraulic pumps 51 and 52 are controlled such that the engine output is distributed, and the process returns.
On the other hand, if the excavation determination means 4 determines that the bucket operation has not been performed in step B10, the process proceeds to step B20, where the excavation determination means 4 further performs the operation based on the electric signal from the turning operation member 54d. It is determined whether or not the turning operation has been performed.
[0167]
As a result of this determination, when the excavation determination means 4 determines that the turning operation has been performed, it means that the stick-in operation and the turning operation have been performed simultaneously, and this is considered to be an excavation operation. Therefore, the process of step B30 is performed.
Next, in step B30, the excavation control unit 6C of the pump tilt angle control unit 6 optimally distributes the engine output from the engine 50 based on the electric signals from the stick operation member 54b and the turning operation member 54d. The distribution of the engine output to each of the hydraulic pumps 51 and 52 is set so as to be performed.
[0168]
Here, the excavation control unit 6C distributes the engine output to the first hydraulic pump 51 with a stick request ratio (for example, about 70%) and distributes the engine output to the second hydraulic pump 52 with a minimum turning ratio (for example, about 30%). . That is, the excavation control unit 6C sends the engine horsepower whose upper limit is set to the low power upper limit horsepower (for example, about 120 PS; about 87.60 kW) to the first hydraulic pump 51 as the stick request horsepower (for example, about 84 PS; 61.32 kW) and the minimum required turning horsepower (for example, about 36 PS; about 26.28 kW) to the second hydraulic pump 52.
[0169]
Then, the pump tilt angles of the hydraulic pumps 51 and 52 are controlled such that the engine output is distributed, and the process returns.
By the way, if the excavation determining means 4 determines in step B20 that the turning operation has not been performed, it is considered that the operation is not an excavation operation, and the pump tilt angle control during the excavation is not performed. And return.
[0170]
Next, the control device of the construction machine according to the present embodiment operates as shown in the flowchart of FIG. 11 in order to perform the optimal power distribution pump tilt angle control routine during lift / turn (step S70 in FIG. 8). .
That is, in step C10, the lift / turn determination unit 5 determines whether a boom-up operation has been performed based on the electric signal from the boom operation member 54a, and as a result of this determination, it is determined that the boom-up has been performed. If so, the process proceeds to step C20, and it is determined whether or not the turning operation has been performed based on the electric signal from the turning operation member 54d.
[0171]
As a result of this determination, when it is determined that the turning operation has been performed, it means that the boom-up operation and the turning operation have been performed simultaneously. Since this is considered to be a lift / turn operation, the process proceeds to step C30. The lift / turn control unit 6C of the pump tilt angle control means 6 controls each hydraulic pressure so that the engine output from the engine 50 is optimally distributed based on the electric signals from the boom operation member 54a and the turn operation member 54d. The distribution of the engine output to the pumps 51 and 52 is set.
[0172]
Here, the lift / turn control unit 6C distributes the engine output to the first hydraulic pump 51 for a boom request rate (for example, about 70%) and distributes the engine output to the second hydraulic pump 52 for the minimum turn request rate (for example, about 30%). . That is, the lift / turn controller 6C supplies the first hydraulic pump 51 with the engine horsepower whose upper limit value is set to the upper limit horsepower (eg, about 140 PS; about 102.20 kW) as a boom request horsepower (eg, about 98 PS; about 71.54 kW). ) And distribute to the second hydraulic pump 52 the minimum required turning horsepower (for example, about 42 PS; about 30.66 kW).
[0173]
Then, the pump tilt angles of the hydraulic pumps 51 and 52 are controlled such that the engine output is distributed, and the process returns.
When the lift / turn determination unit 5 determines that the boom-up operation has not been performed in step C10, and when the lift / turn determination unit 5 determines that the turn operation has not been performed in step C20, Since the operation is not considered to be a swing / turn operation, the process returns without performing the pump tilt angle control during the lift / turn operation.
[0174]
Therefore, according to the control device for a construction machine according to the present embodiment, the engine output is optimally distributed to the hydraulic pumps 51 and 52, so that sufficient engine output is not supplied to the hydraulic pumps 51 and 52 and the pump output is reduced. There is an advantage that work speed can be prevented from being reduced due to shortage, and work efficiency can be improved.
[0175]
Further, the engine output is supplied to the hydraulic pumps 51 and 52 more than necessary, which causes an increase in piping pressure loss to generate a horsepower loss, an increase in hydraulic oil temperature resulting from an increase in internal leak, Another advantage is that inefficiencies in the overall system, such as consuming extra horsepower for cooling, can be reduced.
In the above-described embodiment, two hydraulic pumps are provided, and the engine output is distributed to these hydraulic pumps. However, by providing two or more hydraulic pumps, a work load applied to each hydraulic actuator is provided. , The engine output may be distributed to each of these hydraulic pumps.
[0176]
Further, in the above-described embodiment, the hydraulic pumps 51 and 52 are configured as swash plate rotary piston pumps, but may be any variable displacement pump that can control the pump discharge flow rate by an operation signal from the controller 1, for example. An oblique shaft type piston pump or a variable discharge type vane pump may be used.
Further, in the above-described embodiment, the digging control unit 6B and the excavation control unit 6C, based on the determination result of the low power / high power determination unit 2, determine whether the power is low or high depending on the workload applied to the work device 118. Although the upper limit value of the engine output distributed to each of the hydraulic pumps 51 and 52 is changed between when the power is applied and when the power is applied, the lift / turn controller 6D also uses the working device based on the determination result of the low power / high power determination means 2. The upper limit value of the engine output allocated to each of the hydraulic pumps 51 and 52 may be changed between low power and high power according to the work load applied to the engine 118.
[0177]
Further, in the above-described embodiment, the digging control unit 6B and the excavation control unit 6C, based on the determination result of the low power / high power determination unit 2, determine whether the power is low or high depending on the workload applied to the work device 118. Although the engine output distributed to the hydraulic pumps 51 and 52 is controlled at the time of power, the basic tilt angle control unit 6A operates the working device 118 based on the determination result of the low power / high power determination unit 2. The engine output distributed to the hydraulic pumps 51 and 52 at the time of low power and at the time of high power may be controlled according to the load.
[0178]
Further, in the above-described embodiment, a case is described in which the present invention is applied to a control device for a construction machine that performs negative flow control. However, the present invention is also applicable to a control device for a construction machine that performs positive flow control. good.
[0179]
【The invention's effect】
As described in detail above, claims 1 to 8 According to the above-described control device for a construction machine of the present invention, the engine output is optimally distributed to the respective hydraulic pumps, so that sufficient engine output is not supplied to the hydraulic pumps, the pump output becomes insufficient, and the work speed is reduced. This is advantageous in that work efficiency can be improved and work efficiency can be improved. In addition, it is possible to prevent the engine output from being supplied to the hydraulic pump more than necessary, to cause an increase in piping pressure loss to cause horsepower loss, and to increase internal leak due to a rise in hydraulic oil temperature, Another advantage is that inefficiencies in the overall system, such as consuming extra horsepower for cooling, can be reduced.
[Brief description of the drawings]
FIG. 1 is a control block diagram for explaining pump tilt angle control by optimal power distribution in a control device for a construction machine according to an embodiment of the present invention.
FIG. 2 is an overall configuration diagram of a control device for a construction machine according to an embodiment of the present invention.
FIG. 3 is a schematic diagram for explaining a control valve of the control device for the construction machine according to the embodiment of the present invention.
FIG. 4 is a diagram for explaining a horsepower loss due to a pipe pressure loss in a general construction machine and an effective horsepower that can be supplied to a hydraulic actuator.
FIG. 5 is a diagram showing a relationship between a required flow rate of negative flow control and a negative control pressure in the control device for a construction machine according to one embodiment of the present invention.
FIG. 6 is a diagram illustrating a relationship between an allowable flow rate of negative flow control and a pump discharge pressure in the control device for a construction machine according to one embodiment of the present invention.
FIG. 7 is a flowchart illustrating negative flow control in the control device for the construction machine according to the embodiment of the present invention.
FIG. 8 is a flowchart illustrating a main routine of optimal power distribution pump tilt angle control in the control device for a construction machine according to one embodiment of the present invention.
FIG. 9 is a flowchart illustrating a pump tilt angle control routine at the time of high power in the control device for the construction machine according to the embodiment of the present invention.
FIG. 10 is a flowchart illustrating a low-power pump tilt angle control routine in the control device for the construction machine according to the embodiment of the present invention.
FIG. 11 is a flowchart illustrating a pump tilt angle control routine during lift / turn when the control device for the construction machine according to the embodiment of the present invention;
FIG. 12 is a schematic perspective view showing a conventional construction machine.
[Explanation of symbols]
1 controller (control means)
2 Low power / high power judgment means
3 Digging judgment means
4 Excavation judgment means
5 Lift / turn determination means
6 Pump tilt angle control means
6A Basic tilt angle control unit
6B digging control unit
6C Excavation control unit
6D lift / turn controller
7 Control means for proportional pressure reducing valve for turning
51 1st hydraulic pump
52 Second hydraulic pump
54 Operation members
54a Operating member for boom
54b Operating member for stick
54c Bucket operating member
54d turning operation member
63 Swivel control valve
63a, 63b Proportional pressure reducing valve for turning
102 Upper revolving superstructure

Claims (8)

A plurality of hydraulic pumps driven by an engine provided in the construction machine and discharging hydraulic oil in a tank,
A plurality of operation levers operated by an operator,
A plurality of hydraulic actuators connected to the plurality of hydraulic pumps;
Control means for controlling the tilt angle of the plurality of hydraulic pumps to adjust the discharge flow rate from the plurality of hydraulic pumps,
When the control means determines that the operation is to simultaneously operate two hydraulic actuators of the plurality of hydraulic actuators based on the electric signals from the plurality of operating levers, a combination of the two hydraulic actuators In accordance with the above, the distribution ratio of the engine output distributed to the plurality of hydraulic pumps connected to each of the two hydraulic actuators is set, and the tilt of each of the plurality of hydraulic pumps is set so as to become the distribution ratio. A control device for a construction machine, characterized by controlling an angle. A pressure sensor that detects a pump discharge pressure of hydraulic oil discharged by the plurality of hydraulic pumps,
The control means sets an engine output distributed to each of the plurality of hydraulic pumps based on an upper limit output set in accordance with a detection signal from the pressure sensor, and sets the engine output to be the distributed output. The control device for a construction machine according to claim 1, wherein each tilt angle of the plurality of hydraulic pumps is controlled. The plurality of operation levers include a turning operation lever operated to turn the construction machine, and a stick operation lever operated to operate a stick provided to the construction machine,
An excavation determination unit configured to determine whether the control unit is an excavation operation involving a turning operation and a stick operation based on an electric signal from the turning operation lever and the stick operation lever ,
Pump tilt angle control means for controlling the tilt angle of the hydraulic pump to adjust the discharge flow rate from the hydraulic pump,
When the pump displacement angle control means determines that the excavation work is performed by the excavation determination means, the pump tilt angle control means controls the turning hydraulic actuator and the stick driving hydraulic actuator among the plurality of hydraulic actuators. A distribution ratio of engine output distributed to the plurality of connected hydraulic pumps is set, and a tilt angle of each of the plurality of hydraulic pumps is controlled so as to become the distribution ratio. The control device for a construction machine according to claim 1. A pressure sensor that detects a pump discharge pressure of hydraulic oil discharged by the plurality of hydraulic pumps,
The pump tilt angle control means subtracts a minimum required turn output required for turning the construction machine from an upper limit output set in accordance with a detection signal from the pressure sensor, thereby forming the plurality of pump tilt angles. 4. The construction machine according to claim 3 , wherein an engine output allocated to each of the hydraulic pumps is set, and each of the tilt angles of the plurality of hydraulic pumps is controlled so as to achieve the allocated output. Control device. The plurality of operation levers include a stick operation lever operated to operate a stick provided on the construction machine, and a bucket operation lever operated to operate a bucket provided on the construction machine. ,
The control means,
Digging determination means for determining whether or not a digging operation involving stick operation and bucket operation based on an electric signal from the stick operation lever and the bucket operation lever ,
Pump tilt angle control means for controlling the tilt angle of the hydraulic pump to adjust the discharge flow rate from the hydraulic pump,
The pump tilt angle control means is connected to each of the stick driving hydraulic actuator and the bucket driving hydraulic actuator of the plurality of hydraulic actuators when the digging determining means determines that it is a digging operation. 2. The system according to claim 1, wherein a distribution ratio of the engine output distributed to the plurality of hydraulic pumps is set, and a tilt angle of each of the plurality of hydraulic pumps is controlled so as to become the distribution ratio . Control device for construction machinery. A pressure sensor that detects a pump discharge pressure of hydraulic oil discharged by the plurality of hydraulic pumps,
The pump tilt angle control means subtracts the minimum required output of the bucket required to operate the bucket from the upper limit output set in accordance with the detection signal from the pressure sensor, thereby obtaining the plurality of hydraulic pressures. 6. The control of a construction machine according to claim 5 , wherein an engine output to be allocated to each of the pumps is set, and a tilt angle of each of the plurality of hydraulic pumps is controlled so as to obtain the allocated output. apparatus. The plurality of operation levers include a boom operation lever operated to operate a boom provided on the construction machine, and a turning operation lever operated to turn the construction machine,
Lift / turn determination means for determining whether or not a lift / turn involving a boom operation and a turn operation is performed based on electric signals from the boom operation lever and the turn operation lever ,
Pump tilt angle control means for controlling the tilt angle of the hydraulic pump to adjust the discharge flow rate from the hydraulic pump,
When the pump tilt angle control unit determines that the lift / turn operation is performed by the lift / turn operation unit , each of the boom drive hydraulic actuator and the turn hydraulic actuator of the plurality of hydraulic actuators is used. A distribution ratio of engine output distributed to the plurality of connected hydraulic pumps is set, and a tilt angle of each of the plurality of hydraulic pumps is controlled so as to become the distribution ratio. 2. The control device for a construction machine according to claim 1. A pressure sensor that detects a pump discharge pressure of hydraulic oil discharged by the plurality of hydraulic pumps,
The pump tilt angle control means subtracts a minimum required turn output required for turning the construction machine from an upper limit output set in accordance with a detection signal from the pressure sensor, thereby forming the plurality of pump tilt angles. The construction machine according to claim 7 , wherein an engine output to be allocated to each of the hydraulic pumps is set, and a tilt angle of each of the plurality of hydraulic pumps is controlled so as to become the distributed output. Control device.

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