JP3793705B2

JP3793705B2 - Car body lifting support device

Info

Publication number: JP3793705B2
Application number: JP2001299496A
Authority: JP
Inventors: 太郎月岡; 知治及川
Original assignee: Aichi Corp
Current assignee: Aichi Corp
Priority date: 2001-09-28
Filing date: 2001-09-28
Publication date: 2006-07-05
Anticipated expiration: 2021-09-28
Also published as: JP2003104178A

Description

【０００１】
【発明の属する技術分野】
本発明は、車体持上支持装置に関し、更に詳細には、車幅方向に突出入動可能な張出ビームと、張出ビームの先端部に取り付けられて上下に伸縮動可能なジャッキとを有して構成され、車体の側部に配設された複数のアウトリガ装置を備えた車体持上支持装置に関する。
【０００２】
【従来の技術】
高所作業車は、車体に搭載された高所作業装置を使用して作業台を所望高所位置に移動させ、作業台に搭乗した作業者による高所作業を行なわせるものであり、このように作業台を高所に移動させると、車体側に作用する転倒方向のモーメントが増加して車体支持が不安定になりやすい。このため、従来の高所作業車では、車幅方向に突出入動可能な張出ビームと、張出ビームの先端部に取り付けられて上下に伸縮動可能なジャッキとを有して構成され、車体の側部に配設された複数のアウトリガ装置を有した車体持上支持装置を備えているものがある。
【０００３】
この車体持上支持装置は、図１０に示すように、複数のアウトリガ装置２１と、アウトリガ装置２１にそれぞれ対応して設けられ、張出シリンダ２７及びジャッキシリンダ２４に選択的に油の供給を行なわせる複数のセレクタバルブ３１、３２、３３、３４と、油圧ポンプ（図示せず）からの油をセレクタバルブ３１、３２、３３、３４に給排制御する出入切替バルブ３９とを有して構成されている。出入切替バルブ３９とセレクタバルブ３１、３２、３３、３４は第１油路４７で繋がり、セレクタバルブ３１、３２、３３、３４とジャッキシリンダ２７のボトム室２７ａは第２油路４８で繋がり、ジャッキシリンダ２７のロッド室２７ｂと出入切替バルブ３９は第３油路４９で繋がっている。また、セレクタバルブ３１、３２、３３、３４と張出シリンダ２４のボトム室２４ａは第４油路５０で繋がり、張出シリンダ２４のロッド室２４ｂと第３油路４９は第５油路５１で繋がっている。
【０００４】
第２油路４８及び第３油路４９にはそれぞれ対応してパイロットチェックバルブ６５、６６が配設されている。これらのパイロットチェックバルブ６５、６６は、ジャッキシリンダ２７側への油の流れを許容し、セレクタバルブ３１、３２、３３、３４側及び出入切替バルブ３９側への油の流れを規制するとともに、第２油路４８及び第３油路４９を流れる油の上流側に配設されたパイロットチェックバルブ６５、６６よりも上流側の油路のパイロット圧を受けると下流側に配設されたパイロットチェックバルブ６５、６６が開放してセレクタバルブ３１、３２、３３、３４側及び出入切替バルブ３９側への油の流れを許容する、いわゆるダブルパイロットチェックバルブ６７を構成している。
【０００５】
このような車体持上支持装置により、図１０中の矢印Ａで示すアウトリガ装置２１のジャッキ２７を伸長動させてジャッキを接地させるには、先ず、セレクタバルブ３４の操作レバー３４ａをジャッキ側に操作する。続いて出入切替バルブ３９の操作レバー３９ａを伸長側に操作する。この操作レバー３９ａが伸長側に操作されると油圧ポンプ（図示せず）から吐出した油は出入切替バルブ３９、セレクタバルブ３４及び第２油路４８を通ってジャッキシリンダ２７のボトム室２７ａに供給される。またこれと同時に、第３油路４９内に配設されたパイロットチェックバルブ６６は第２油路４８内のパイロット圧を受けて開放する。その結果、ジャッキシリンダ２７が伸長動する。そしてジャッキが接地して出入切替バルブ３９の操作レバー３９ａが中立位置に操作されると、ジャッキシリンダ２７への油の供給が遮断され、ジャッキは接地状態に維持される。
【０００６】
【発明が解決しようとする課題】
ここで、作業者が前述したセレクタバルブ３４と異なるセレクタバルブ３１（例えば、図１０の矢印Ｂの示すバルブ）の操作レバー３１ａを誤って張出側に操作したときに、第２油路４８に配設されたパイロットチェックバルブ６５よりもセレクタバルブ３４側の第２油路４８内の油圧と、第３油路４９に配設されたパイロットチェックバルブ６６よりも出入切替バルブ３９側の第３油路４９内の油圧が高い状態にあると、ダブルパイロットチェックバルブ６５が開放して第２油路４８及び第３油路４９が連通状態になる場合がある。
【０００７】
このような場合、第２油路４８内の油は、最初に操作したセレクタバルブ３４、第１油路４７、誤操作したセレクタバルブ３１及び誤操作したセレクタバルブ３１と図１０の矢印Ｃで示す張出シリンダ２４とを繋ぐ第４油路５０を通り、この張出シリンダ２４のボトム室２４ａに供給される。一方、この張出シリンダ２４のロッド室２４ｂは、第３油路４９に配設されたパイロットチェックバルブ６６が開放状態にあるので、矢印Ａが示すアウトリガ装置２１のジャッキシリンダ２７のロッド室２７ｂと連通した状態になる。その結果、張出シリンダ２４とジャッキシリンダ２７は閉回路を構成し、出入切替３９が中立状態にあるにも拘わらず、ジャッキシリンダ２７が縮小動するとともに張出シリンダ２４が伸長動するという問題が生じる。
【０００８】
本発明は、このような問題に鑑みてなされたものであり、セレクタバルブが誤操作されても張出シリンダやジャッキシリンダを伸縮動させない車体持上支持装置を提供することを目的とする。
【０００９】
【課題を解決するための手段】
前記課題を解決するために本発明に係わる車体持上支持装置は、車幅方向に張出し自在な張出ビームと、張出ビームを車幅方向に突出入動させる張出シリンダと、張出ビームの先端部に取り付けられて上下に伸縮動自在なジャッキと、ジャッキを伸縮動させるジャッキシリンダとを有して構成され、車体の側部に配設された複数のアウトリガ装置と、アウトリガ装置にそれぞれ対応して設けられ、張出シリンダ及びジャッキシリンダに選択的に油の供給を行なわせる複数のシリンダ選択バルブ（例えば、実施形態におけるセレクタバルブ３１、３２、３３、３４）と、油圧供給源（例えば、実施形態における油圧ポンプＰ）からの油をシリンダ選択バルブに給排制御するシリンダ駆動制御バルブ（例えば、実施形態における出入切替バルブ３９）とを有し、シリンダ駆動制御バルブとシリンダ選択バルブとを繋ぐ第１油路と、シリンダ選択バルブとジャッキシリンダのボトム室とを繋ぐ第２油路と、ジャッキシリンダのロッド室とシリンダ駆動制御バルブとを繋ぐ第３油路と、シリンダ選択バルブと張出シリンダのボトム室とを繋ぐ第４油路と、張出シリンダのロッド室と第３油路とを繋ぐ第５油路とを有し、第２油路及び第３油路にそれぞれ対応してパイロットチェックバルブを有し、パイロットチェックバルブは、ジャッキシリンダ側への油の流れを許容し、シリンダ選択バルブ側及びシリンダ駆動制御バルブ側への油の流れを規制するとともに、第２油路及び第３油路を流れる油の上流側に配設されたパイロットチェックバルブよりも上流側の油路のパイロット圧を受けると下流側に配設されたパイロットチェックバルブが開放してシリンダ選択バルブ側及びシリンダ駆動制御バルブ側への油の流れを許容するように構成されたダブルパイロットチェックバルブとを有してなる車体持上支持装置において、シリンダ駆動制御バルブは中立状態においてシリンダ選択バルブへの油の供給を遮断するように構成され、シリンダ駆動制御バルブが中立状態に切り替えられたときに、第２油路及び第３油路内の油圧を低下させる圧力低下手段（例えば、実施形態における第６油路５２、第７油路５３、パイロットチェックバルブ６１）を有する。
【００１０】
上記構成の車体持上支持装置によれば、シリンダ選択バルブがジャッキ側に操作され、油がシリンダ駆動制御バルブを介してアウトリガ装置のジャッキシリンダに供給されてジャッキが伸長動して接地状態となり、シリンダ駆動制御バルブが中立状態に切り替えられたときに、最初に操作されたシリンダ選択バルブと異なるシリンダ選択バルブが誤って張出側に操作されると、第２油路及び第３油路内の油圧は低下した状態になる。このため、伸長動したジャッキシリンダに繋がる第２油路及び第３油路内に配設されたダブルパイロットチェックバルブはシリンダ選択バルブ側及びシリンダ駆動制御バルブ側への油の流れを規制した状態にし、その結果、伸長動したジャッキシリンダに繋がった第２油路が誤操作されたシリンダ選択バルブを介してこれに繋がった張出シリンダのボトム室に連通しても、この張出シリンダにはこれを伸長動させる油圧は作用しない。また、第２油路に配設されたパイロットチェックバルブによりジャッキシリンダの縮小動は規制された状態となるので、張出シリンダのロッド室内の油はジャッキシリンダ側へ流出しない。このため、ジャッキシリンダが縮小動するとともに、張出シリンダが伸長動する事態を防止することができる。
【００１１】
上記構成の車体持上支持装置において、圧力低下手段は、第１油路とタンクとの間を繋ぎ、第１絞りを有した第６油路と、第３油路とタンクとの間を繋ぎ、第２絞りを有した第７油路と、第６油路及び第７油路に配設され、油供給源とシリンダ駆動制御バルブとを繋ぐ第８油路にパイロットラインを繋ぎ、パイロットラインに第３絞りを有し、第８油路に流れる油のパイロット圧をパイロットラインを介して受けてタンク側への油の流れ規制を解除して第２油路及び第３油路内の油を第６油路及び第７油路内を介して前記タンクに流すパイロットチェックバルブとを有して構成してもよい。
【００１２】
上記構成の車体持上支持装置によれば、シリンダ駆動制御バルブが中立状態に切り替えられると、パイロットチェックバルブは第８油路に流れる油のパイロット圧を受けて第６油路及び第７油路内の油のタンク側への油の流れ規制を解除する。このため、第２油路及び第３油路は第６油路、第７油路及びパイロットチェックバルブを介してタンクに連通し、その結果、第２油路及び第３油路内の油圧が高い状態であれば、この油圧を簡易な構成で低下させることができる。
【００１３】
上記構成の車体持上支持装置において、圧力低下手段は、シリンダ駆動バルブが中立状態にあるか否かを検出する中立検出手段（例えば、実施形態における中立位置センサ７５）と、第１油路とタンクとの間を繋ぐ第６油路と、第３油路タンクとの間を繋ぐ第７油路と、第６油路及び第７油路に配設され、これらの油路を連通又は遮断する油路開閉バルブ（例えば、実施形態における電磁バルブ７１）と、中立検出手段によりシリンダ駆動バルブが中立状態にあると検出されているときに油路開閉バルブを作動させて第６油路及び第７油路を連通させるバルブ作動制御手段（例えば、実施形態におけるコントローラ７３）とを有して構成してもよい。
【００１４】
上記構成の車体持上支持装置によれば、シリンダ駆動制御バルブが中立状態に切り替えられると、バルブ作動制御手段が油路開閉バルブを作動させ、油路開閉バルブが第６油路及び第７油路を連通状態にする。このため、第２油路及び第３油路は第６油路、第７油路及び油路開閉バルブを介してタンクに連通し、その結果、第２油路及び第３油路内の油圧が高い状態であれば、この油圧を確実に低下させることができる。尚、シリンダ駆動制御バルブが中立状態に切り替えられたときから所定時間（圧力が抜けるための時間）だけ、バルブ作動制御手段が油路開閉バルブを作動させて第６油路及び第７油路を連通状態にするようにしてもよい。
【００１５】
また、本発明に係わる車体持上支持装置は、車幅方向に張出し自在な張出ビームと、張出ビームを車幅方向に突出入動させる張出シリンダと、張出ビームの先端部に取り付けられて上下に伸縮動自在なジャッキと、ジャッキを伸縮動させるジャッキシリンダとを有してなるアウトリガ装置を車体の左右に複数配設し、アウトリガ装置にそれぞれ対応して設けられ、張出シリンダ及びジャッキシリンダに選択的に油の供給を行なわせる複数のシリンダ選択バルブと、油圧供給源からの油をシリンダ選択バルブに給排制御するシリンダ駆動制御バルブとを有し、シリンダ駆動制御バルブとシリンダ選択バルブとを繋ぐ第１油路と、シリンダ選択バルブとジャッキシリンダのボトム室とを繋ぐ第２油路と、ジャッキシリンダのロッド室とシリンダ駆動制御バルブとを繋ぐ第３油路と、シリンダ選択バルブと張出シリンダのボトム室とを繋ぐ第４油路と、張出シリンダのロッド室と第３油路とを繋ぐ第５油路とを有し、第２油路及び第３油路にそれぞれ対応してパイロットチェックバルブを有し、パイロットチェックバルブは、ジャッキシリンダ側への油の流れを許容し、シリンダ選択バルブ側及びシリンダ駆動制御バルブ側への油の流れを規制するとともに、第２油路及び第３油路を流れる油の上流側に配設されたパイロットチェックバルブよりも上流側の油路のパイロット圧を受けると下流側に配設されたパイロットチェックバルブが開放してシリンダ選択バルブ側及びシリンダ駆動制御バルブ側への油の流れを許容するように構成されたダブルパイロットチェックバルブとを有してなる車体持上支持装置において、シリンダ駆動制御バルブは中立状態においてシリンダ選択バルブへの油の供給を遮断するように構成され、第５油路は、複数の張出シリンダの各ロッド室間を繋ぐロッド接続油路と、ロッド接続油路に連通して第３油路に繋がる連通油路とを有し、連通油路に配設され、油供給源とシリンダ駆動制御バルブとを繋ぐ第８油路にパイロットラインを繋ぎ、張出シリンダ側への油の流れを許容し、シリンダ駆動バルブ側への油の流れを規制するとともに、シリンダ駆動バルブが中立状態にあるときに第８油路を流れる油のパイロット圧をパイロットラインを介して受けてもシリンダ駆動バルブ側への油の流れを規制するパイロットチェックバルブを有する。
【００１６】
上記構成の車体持上支持装置によれば、シリンダ選択バルブがジャッキ側に操作され、油がシリンダ駆動制御バルブを介してアウトリガ装置のジャッキシリンダに供給されてジャッキが伸長動して接地状態となり、シリンダ駆動制御バルブが中立状態に切り替えられたときに、最初に操作されたシリンダ選択バルブと異なるシリンダ選択バルブが誤って張出側に操作されると、第５油路から第３油路への油の流れは遮断された状態になる。このため、伸長動したジャッキシリンダに繋がった第２油路が誤操作されたシリンダ選択バルブに繋がった張出シリンダのボトム室に連通し、この張出シリンダを伸長動させ方向の油圧が作用しても、張出シリンダのロッド室に繋がる第５油路は閉塞された状態にあるので、張出シリンダの伸長動を防止することができる。また、第５油路から第３油路に油が流れないので伸長動したジャッキシリンダの縮小動を防止することができる。
【００１９】
【発明の実施の形態】
以下、本発明の好ましい実施の形態を図１から図９に基づいて説明する。本実施の形態は車体上に起伏且つ旋回動可能であり伸縮動可能に構成されたブームの先端に作業台を有した高所作業車の態様を示す。
【００２０】
【第１の実施の形態】
最初に、本発明に係る車体持上支持装置の第１の実施の形態を説明する前に、この車体持上支持装置を搭載した高所作業車を説明する。高所作業車１は、図１に示すように、トラック車両をベースとして構成されており、車体３の前部に運転キャビン５を有し、車体３の後部には車体３に内蔵された旋回モータ（図示せず）により駆動されて水平旋回可能に構成された旋回台７が配設されている。旋回台７の上部には基端部を枢結したブーム９が取り付けられ、このブーム９は、基端ブーム９ａ、中間ブーム９ｂ、先端ブーム９ｃを入れ子式に組み合わせて内蔵された伸縮シリンダ１１により伸縮動されるように構成されている。ブーム９は起伏シリンダ１３により起伏動可能に構成されている。先端ブーム９ｃの先端にはブーム９の起伏動に拘わらず水平状態に保持された作業台１５が取り付けられている。
【００２１】
次に、車体持上支持装置について図２から図５を更に追加して説明する。車体持上支持装置２０は、運転キャビン５よりも車両後方側の車体前後の左右両側部に配設されて車両を持ち上げ支持するアウトリガ装置２１と、アウトリガ装置２１の駆動を操作する操作装置３０とを有して構成されている。アウトリガ装置２１は、運転キャビン５よりも車両後方側の車体前後の左右両側部に配設されて車幅方向に張出し自在に構成された張出ビーム２３と、張出ビーム２３を車幅方向に突出入動させる張出シリンダ２４と、張出ビーム２３の先端部に取り付けられて上下に伸縮動自在なジャッキ２６と、ジャッキ２６を伸縮動させるジャッキシリンダ２７とを有して構成されている。ジャッキ２６は、張出ビーム２３の先端部に上下に取り付けられたアウターポスト２６ａと、アウターポスト２６ａ内に突出入可能に構成されたインナーポスト２６ｂと、これらのポスト内に内蔵されてアウターポスト２６ａに対してインナーポスト２６ｂを突出入動させる前述したジャッキシリンダ２７とを有して構成されている。
【００２２】
このアウトリガ装置２１の駆動を操作する操作装置３０は車両後部に配設され、４つのセレクタバルブ３１、３２、３３、３４と１つの出入切替バルブ３９とを有して構成されている。操作装置３０の前面には５つの操作レバー３１ａ、３２ａ、３３ａ、３４ａ、３９ａの全レバーの基部を挿通させた貫通孔４１を有したパネル４３が配設されている。セレクタバルブ３１、３２、３３、３４は、アウトリガ装置２１にそれぞれ対応して設けられ、張出シリンダ２４及びジャッキシリンダ２７に選択的に油の供給を行なわせる機能を有し、６ポート３位置の手動式デテント付き切替弁であり、中立位置から前後に傾動操作可能な前述した操作レバー３１ａ、３２ａ、３３ａ、３４ａを有している。操作レバー３１ａ、３２ａ、３３ａ、３４ａを前後のいずれか一方側に傾動操作すると、セレクタバルブ３１、３２、３３、３４はジャッキシリンダ２７に油の供給を行ない、操作レバー３１ａ、３２ａ、３３ａ、３４ａを前後のいずれか他方側に傾動操作すると、セレクタバルブ３１、３２、３３、３４は張出シリンダ２４に油の供給を行なうように構成されている。
【００２３】
一方、出入切替バルブ３９は油圧ポンプＰからの油をセレクタバルブ３１、３２、３３、３４に給排制御する機能を有し、６ポート３位置の手動式デテント付き切替弁であり、中立位置から前後に傾動操作可能な前述した操作レバー３９ａを有している。この操作レバー３９ａを前後のいずれか一方側に傾動操作すると、出入切替バルブ３９はジャッキシリンダ２７又は張出シリンダ２４を伸長動させる方向に油を供給し、操作レバー３９ａを前後のいずれか他方側に傾動操作すると、出入切替バルブ３９はジャッキシリンダ２７又は張出シリンダ２４を縮小動させる方向に油を供給するように構成されている。
【００２４】
４つのセレクタバルブ３１〜３４及び出入切替バルブ３９は、図４（ｂ）に示すように、車幅方向に整列された状態で配設されており、最も左側（図４の下側）に配設されたセレクタバルブ３１は、車両左前側に配設されたアウトリガ装置２１に対応したバルブであり、このセレクタバルブ３１の右側に配設されたセレクタバルブ３２は車両左後側に配設されたアウトリガ装置２１に対応したバルブであり、セレクタバルブ３２の右側に配設されたバルブ（中央部のバルブ）は出入切替バルブ３９である。更に、出入切替バルブ３９の右側に配設されたセレクタバルブ３３は車両右前側に配設されたアウトリガ装置２１に対応したバルブであり、このセレクタバルブ３３の右側に配設されたセレクタバルブ３４は車両右後側に配設されたアウトリガ装置２１に対応したバルブである。
【００２５】
ここで、車両右後側に配設されたアウトリガ装置３２のセレクタバルブ３４と出入切替バルブ３９を含む油圧回路を図３を使用して説明する。セレクタバルブ３４は、図３に示すように、第１油路４７を介して出入切替バルブ３９に繋げられ、第２油路４８を介してジャッキシリンダ２７のボトム室２７ａに繋げられ、更に第４油路５０を介して張出シリンダ２４のボトム室２４ａに繋げられている。出入切替バルブ３９は第３油路４９を介してジャッキシリンダ２７のロッド室２７ｂに繋げられ、第８油路５４を介して油圧ポンプＰに繋げられている。張出シリンダ２４のロッド室２４ｂは第５油路を介して第３油路４９に繋げられている。第２油路４８及び第３油路４９にはそれぞれ対応してパイロットチェックバルブ６５、６６が配設され、パイロットチェックバルブ６５、６６は、ジャッキシリンダ２７側への油の流れを許容し、セレクタバルブ３４側及び出入切替バルブ３９側への油の流れを規制するとともに、第２油路４８及び第３油路４９を流れる油の上流側に配設されたパイロットチェックバルブ６５、６６よりも上流側の油路のパイロット圧を受けると下流側に配設されたパイロットチェックバルブ６５、６６が解放してセレクタバルブ３４側及び出入切替バルブ３９側への油の流れを許容するダブルパイロットチェックバルブ６７を構成している。
【００２６】
また、第１油路４７とタンクＴ間には第１絞り５６を有した第６油路５２が繋げられ、第３油路４９とタンクＴ間には第２絞り５７を有した第７油路５３が繋げられている。尚、第６油路５２と第７油路５３はタンクＴ側で合流して一つの油路を形成している。
【００２７】
この合流した第６油路５２と第７油路５３には、第８油路５４に繋がって第３絞り５８を有したパイロットライン６０を備えて第８油路５４に流れる油のパイロット圧をパイロットライン６０を介して受けてタンクＴ側への油の流れ規制を解除するパイロットチェックバルブ６１が設けられている。
【００２８】
尚、車両右前に配設されたアウトリガ装置２１の油圧回路、車両左後に配設されたアウトリガ装置２１の油圧回路、車両左前に配設されたアウトリガ装置２１の油圧回路は、前述した車両右後に配設されたアウトリガ装置２１の油圧回路に準じるので、同一態様部分については同一符号を附してその説明を省略する。その結果、４つのセレクタバルブ３１〜３４と出入切替バルブ３９は図２に示す油圧回路になる。図２に示す油圧回路では、油圧ポンプＰから吐出した油が流れる第８油路５４にはアンロードバルブ６３が設けられている。このバルブは出入切替バルブ３９が中立状態にされて油の給排制御を停止させた状態になると、第８油路５４内の油圧を所定圧に維持するように余分な油をタンクＴに戻す機能を有している。
【００２９】
さて、上記構成の車体持上支持装置２０において、図２に示すように、車両右後のアウトリガ装置２１（図２の矢印Ａで示すアウトリガ装置２１）のジャッキを伸長動させて接地させるには、先ず、セレクタバルブ３４の操作レバー３４ａをジャッキ側（図２の上側）に操作する。続いて出入切替バルブ３９の操作レバー３９ａを伸長側（図２の上側）に操作する。この操作レバー３９ａが伸長側に操作されると油圧ポンプＰから吐出した油は第８油路５４、出入切替バルブ３９、第１油路４７、セレクタバルブ３４及び第２油路４８を通ってジャッキシリンダ２７のボトム室２７ａに供給される。またこれと同時に、第３油路４９内に配設されたパイロットチェックバルブ６６は第２油路４８内のパイロット圧を受けて開放する。その結果、第３油路４９は連通状態になり、ジャッキシリンダ２７のロッド油室２７ｂ内の油は第３油路４９及び出入切替バルブ３９を介してタンクＴに流出可能となってジャッキシリンダ２７が伸長動する。そして図１に示す車両右後に配設されたジャッキ２６が伸長動して接地し、出入切替バルブ３９の操作レバー３９ａが中立位置に操作されると、ジャッキシリンダ２７への油の供給が遮断されてジャッキ２６は接地状態に維持される。
【００３０】
この状態で、例えば、作業者が前述したセレクタバルブ３４と異なるセレクタバルブ３１（例えば、図２の矢印Ｂで示すバルブ）の操作レバー３１ａを誤って張出側（図２の下側）に操作した場合を想定して説明する。ここで、操作レバー３１ａが張出側に操作されたときに、第２油路４８に配設されたパイロットチェックバルブ６５よりもセレクタバルブ３４側の第２油路４８内の油圧と、第３油路４９に配設されたパイロットチェックバルブ６６よりも出入切替バルブ３９側の第３油路４９内の油圧が高い状態であると、ダブルパイロットチェックバルブ６６が開放して第２油路４８及び第３油路４９が連通状態になる場合がある。
【００３１】
このような場合、第２油路４８内の油は、最初に操作したセレクタバルブ３４、第１油路４７、誤操作したセレクタバルブ３１及び誤操作したセレクタバルブ３１に繋がる第４油路５０を通って、この第４油路５０に繋がる張出シリンダ２４（図２の矢印Ｃで示すシリンダ）のボトム室２４ａに供給される。一方、この張出シリンダ２４のロッド室２４ｂは、第３油路４９に配設されたパイロットチェックバルブ６６（図２の矢印Ｄで示すバルブ）が開放状態にあるので、矢印Ａで示すアウトリガ装置２１のジャッキシリンダ２７のロッド室２７ｂと連通した状態になっている。その結果、張出シリンダ２４とジャッキシリンダ２７は閉回路を構成し、出入切替バルブ３９が中立状態にあるにも拘わらず、ジャッキシリンダ２７が縮小動するとともに張出シリンダ２４が伸長動する。即ち、操作装置３０を操作する作業者の意志に反してアウトリガ装置２１が作動することになる。
【００３２】
しかしながら、本発明に係わる車体持上支持装置２０では、出入切替バルブ３９が中立状態に切り替えられると、アンロードバルブ６３が第８油路５４内の油圧を低下させ、この結果、第６油路５２及び第７油路５３内に配設されたパイロットチェックバルブ６１がタンクＴ側への油の流れを規制するように作動するがパイロットライン６０に設けられた第３絞り５８によりこの絞り５８とパイロットチェックバルブ６１間の油圧低下速度を遅くする。このため、出入切替バルブ３９が中立状態に切り替えられたときからパイロットチェックバルブ６１によるタンクＴ側への油の流れを完全に遮断するまでに、時間差が発生する。その結果、この時間の間に第２油路４８及び第３油路４９内の油が第６油路５２、第７油路５７及びパイロットチェックバルブ６１を介してタンクＴに流出し、第２油路４８及び第３油路４９内の油圧が低下する。このため、伸長動したジャッキシリンダ２７（矢印Ａが示したアウトリガ装置２１に対応するもの）に繋がる第２油路４８及び第３油路４９内に配設されたダブルパイロットチェックバルブ６７は、セレクタバルブ側３４及び出入切替バルブ３９側への油の流れを規制した状態になる。その結果、伸長動したジャッキシリンダ２７に繋がった第２油路４８が誤操作されたセレクタバルブ３１に繋がった張出シリンダ２４（矢印Ｃで示すシリンダ）のボトム室２４ａに連通しても、この張出シリンダ２４にはこれを伸長動させる油圧は作用しない。また、第２油路４８に配設されたパイロットチェックバルブ６５によりジャッキシリンダ２７の縮小動は規制された状態となるので、張出シリンダ２４のロッド室２４ｂ内の油はジャッキシリンダ２７側へ流出しない。このため、ジャッキシリンダ２７が縮小動するとともに、張出シリンダ２４が伸長動する事態を防止することができる。
【００３３】
尚、前述した実施の形態では、車両左前のアウトリガ装置２１に対応したセレクタバルブ３１を誤操作した場合を説明したがこれに限るものではなく、車両右前、車両左後のアウトリガ装置２１に対応したそれぞれのセレクタバルブ３３，３２を誤操作した場合も前述した場合と同様の効果を生じる。
【００３４】
また、前述した実施の形態では、第６油路５２及び第７油路５３内にパイロットチェックバルブ６１を配設したが、図５に示すように、この代わりに電磁バルブ７１を設けてもよい。電磁バルブ７１は３ポート２位置の切替弁であり、ソレノイド７１ａが励磁状態にされると第６油路５２及び第７油路５３を連通状態にしてタンクＴ側への油の流れを許容し、ソレノイド７１ａが非励磁状態にされると第６油路５２及び第７油路５３を遮断状態にしてタンクＴ側への油の流れを遮断する。この電磁バルブ７１の作動制御はコントローラ７３により行なわれる。コントローラ７３には出入切替バルブ３９に装着された中立位置センサ７５が電気的に接続され、コントローラ７３は出入切替バルブ３９が中立位置にある旨の中立信号を中立位置センサ７５から受けとっている状態のときに電磁バルブ７１のソレノイド７１ａを励磁させるように構成する。
【００３５】
このように構成することで、出入切替バルブ３９が中立状態に切り替えられると、前述したパイロットチェックバルブ６１の場合と同様に第２油路５２及び第３油路５３内の油圧を低下させることができ、ジャッキシリンダ２７が縮小動するとともに、誤操作されたセレクタバルブ３１に繋がった張出シリンダ２４が伸長動する事態を防止することができる。また、出入切替バルブ３９の中立状態は中立位置センサ７５により検出され、このセンサの情報に応じて電磁バルブ７１が作動するので、第２油路５２及び第３油路５３の開放制御を確実且つ迅速に行なうことができる。尚、コントローラ７３は出入切替バルブ３９が中立状態に切り替えられたときから所定時間（圧力が抜けるための時間）だけ、電磁バルブ７１を作動させて第６油路及び第７油路を連通状態にするようにしてもよい。このようにすることで、張出シリンダ２４に伸長方向の力が作用した場合に張出シリンダ２４が伸長動する事態を未然に防止することができる。
【００３６】
【第２の実施の形態】
次に、車体持上支持装置２０の第２の実施の形態を説明する。第２の実施の形態においては第１の実施の形態との相違点のみを説明し、第１の実施の形態と同一態様部分については同一符号を附してその説明を省略する。図６に示すように、第５油路５１は、４つのアウトリガ装置２１のそれぞれの張出シリンダ２４の各ロッド室２４ｂ間を繋ぐロッド接続油路５１ａと、このロッド接続油路５１ａに連通して第３油路４９に繋がる連通油路５１ｂとを有して構成されている。連通油路５１ｂには、第８油路５４にパイロットライン７７を繋ぎ、張出シリンダ２４側への油の流れを許容し、出入切替バルブ３９側への油の流れを規制するとともに、出入切替バルブ３９が中立状態にあるときに第８油路５４を流れる油のパイロット圧をパイロットライン７７を介して受けても出入切替バルブ３９側への油の流れを規制するパイロットチェックバルブ７９が設けられている。
【００３７】
上記構成の車体持上支持装置２０によれば、車両右後のアウトリガ装置２１に対応したセレクタバルブ３４がジャッキ側に操作され、油が出入切替バルブ３９を介して矢印Ａの示すアウトリガ装置３２のジャッキシリンダ２７に供給されて図１に示すジャッキ２６が伸長動して接地状態となり、出入切替バルブ３９が中立状態に切り替えられたときに、最初に操作されたセレクタバルブ３４と異なるセレクタバルブ３１が誤って張出側に操作された場合には、第８油路５４内の油圧が低下してパイロットチェックバルブ７９により第５油路５１から第３油路４９への油の流れを遮断する。このため、矢印Ａの示すアウトリガ装置２１の伸長動したジャッキシリンダ２７に繋がった第２油路４８が誤操作されたセレクタバルブ３１に繋がった矢印Ｃの示す張出シリンダ２４のボトム室２４ａに連通し、この張出シリンダ２４を伸長動させる方向の油圧が張出シリンダ２４に作用しても、この張出シリンダ２４のロッド室２４ｂに繋がる第５油路５１は閉塞された状態にあるので、この張出シリンダ２４の伸長動を規制することができる。また、第５油路５１から第３油路４に油は流れないので、矢印Ａの示すアウトリガ装置３２の伸長動したジャッキシリンダ２７の縮小動を規制することができる。
【００３８】
このように、第２の実施の形態の車体持上支持装置２０は、出入切替バルブ３９が中立状態に切り替えられたときに第２油路４８及び第３油路４９内の油圧が高い状態であってもこの油圧を下げることはせず、張出シリンダ２４の伸長動を規制するように構成されている。このため、油圧を下げる手段が不要となり油圧回路の構成をより簡易にすることができる。
【００３９】
【第３の実施の形態】
次に、車体持上支持装置２０の第３の実施の形態を説明する。第３の実施の形態においては第１の実施の形態との相違点のみを説明し、第１の実施の形態と同一態様部分については同一符号を附してその説明を省略する。第３の実施の形態の車体持上支持装置２０は、図２に示す油圧回路において第６油路５３及び第７油路５４を有しておらず、図１０に示す従来の油圧回路と同一である。また、図７に示すように、操作装置３０の前面に配設されたパネル４３の裏側には貫通孔４１の左右両端部の外側に上下に延びたプレート支持部材８３が配設され、この一対のプレート支持部材８３間にプレート８５が上下に移動自在に装着されている。
【００４０】
プレート８５は、図８及び図９を更に追加して説明すると、左右（図８の上下方向）に延びて矩形状であり、中央部に左右に延びた矩形状の挿通孔８７が形成されている。図９（ａ）に示すように、挿通孔８７の左右方向の幅Ｘ１は左右に並ぶ５つの操作レバー３１ａ、３２ａ、３９ａ、３３ａ、３４ａのうち最外側に配設された一対の操作レバー３１ａ、３４ａ間の距離Ｘ０よりも大きな寸法を有している。また、挿通孔８７の上下方向の幅Ｙ０は、操作レバー３１ａ、３２ａ、３３ａ、３４ａが中立位置から前後に傾動操作したときに傾動操作したときの位置と中立位置との幅と略同一の寸法を有している。但し、駆動レバー３９ａが配設された部分に相当する挿通孔８７の中央部における上下方向の幅Ｙ１は、操作レバー３１ａ、３２ａ、３３ａ、３４ａの位置に拘わらず操作レバー３９ａが挿通孔８７の端部に当接しない幅、例えば、操作レバー３９ａの可動幅と略同一寸法の幅を有している。また、操作レバー３９ａが配設された部分に相当する挿通孔８７の中央部における左右方向の幅Ｘ２は、操作レバー３９ａの左右方向の幅よりも大きな寸法を有している。
【００４１】
上記構成の操作装置において、例えば、図９（ａ）に示す操作レバー３９ａとこのレバーの左右に隣接する操作レバー３２ａ、３３ａが中立位置あり、左右両端部に配設された操作レバー３１ａ、３４ａが前側に傾動操作されている状態のときに、図９（ｂ）に示すように、操作レバー３９ａの左側に隣接する操作レバー３２ａが誤操作されて後側に傾動操作されると、この操作レバー３２ａによりプレート８５が後側に移動する。これと同時に、挿通孔８７の上側端部が左右両端部に配設された操作レバー３１ａ、３４ａを後側に押し、これらの操作レバー３１ａ、３４ａが中立位置に移動する。このため、既に傾動操作されている操作レバー３１ａ、３４ａの傾動方向と異なる方向に他の操作レバー３２ａが操作されても、傾動方向が相違する操作レバーが混在する事態を防止することができる。
【００４２】
その結果、前述した従来技術の図１０に示すように、セレクタバルブ３４がジャッキ側に操作されるとともに出入切替バルブ３９が伸長側に操作されてジャッキシリンダ２７が伸長動してジャッキ２６が接地し、出入切替バルブ３９が中立状態に操作された後に他のセレクタバルブ３１が張出側に操作されると、他のセレクタバルブ３１に繋がった張出シリンダ２４が伸長動する場合、図９を更に追加して説明すると、プレート８５を備えた操作装置３０を使用すれば、後から操作された他のセレクタバルブ３１が張出側に操作されると、既に操作されているセレクタバルブ３４の操作レバー３４ａは中立位置に移動する。このため、第２油路４８と第１油路４７は遮断された状態になるので、後から操作された他のセレクタバルブ３１に繋がる張出シリンダ２４に油圧は作用しないので、この張出シリンダ２４が伸長動することはなく、また既に操作したセレクタバルブ３４に繋がるジャッキシリンダ２７も縮小動することはない。
【００４３】
このように、操作装置３０にプレート８５を設けるだけで作業者の意に反したシリンダの駆動を防止することができ、経済的である。
【００４４】
【発明の効果】
以上説明したように、本発明における車体持上支持装置によれば、第２油路と第３油路に油圧を低下させる油圧低下手段を設けることで、ジャッキが伸長動して接地状態となり、シリンダ駆動制御バルブが中立状態に切り替えられたときに、最初に操作されたシリンダ選択バルブと異なるシリンダ選択バルブが誤って張出側に操作されても、油圧低下手段が第２油路と第３油路の油圧を低下させるので、誤って操作されたシリンダ選択バルブに繋がる張出シリンダに油圧は作用せず、張出シリンダの伸長動を防止することができるとともに、接地状態にあるジャッキのジャッキシリンダの縮小動を防止することができる。
【００４５】
また、本発明における車体持上支持装置によれば、第５油路を複数の張出シリンダの各ロッド室間を繋ぐロッド接続油路とロッド接続油路に連通して第３油路に繋がる連通油路とを有して構成し、連通油路にパイロットチェックバルブを設けることで、ジャッキが伸長動して接地状態となり、シリンダ駆動制御バルブが中立状態に切り替えられたときに、最初に操作されたシリンダ選択バルブと異なるシリンダ選択バルブが誤って張出側に操作されると、第５油路から第３油路への油の流れは遮断状態になり、誤操作されたシリンダ選択バルブに繋がった張出シリンダを伸長動させ方向の油圧が作用しても、張出シリンダのロッド室に繋がる第５油路は閉塞された状態にあるので、張出シリンダの伸長動を規制することができる。また、第５油路から第３油路に油が流れないので接地状態にあるジャッキのジャッキシリンダの縮小動を防止することができる。
【図面の簡単な説明】
【図１】本発明の第１の実施の形態における車体持上支持装置を搭載した高所作業車の斜視図を
示す。
【図２】本発明の第１の実施の形態における車体持上支持装置の油圧回路図を示す。
【図３】本発明の第１の実施の形態における車体持上支持装置の一部の油圧回路図を示す。
【図４】本発明の第１の実施の形態における操作装置を示し、同図（ａ）は操作装置の平面図で
あり、同図（ｂ）は操作装置の側面図である。
【図５】本発明の第１の実施の形態における車体持上支持装置の油圧回路図を示す。
【図６】本発明の第２の実施の形態における車体持上支持装置の油圧回路図を示す。
【図７】本発明の第３の実施の形態における操作装置を示し、同図（ａ）は操作装置の平面図で
あり、同図（ｂ）は操作装置の側面図である。
【図８】本発明の第３の実施の形態における操作装置のプレートの平面図を示す。
【図９】本発明の第３の実施の形態における操作装置の作動を説明するための図である。
【図１０】従来技術における車体持上支持装置の油圧回路図を示す。
【符号の説明】
２０車体持上支持装置
２１アウトリガ装置
２３張出ビーム
２３張出シリンダ
２６ジャッキ
２７ジャッキシリンダ
３１、３２、３３、３４セレクタバルブ（シリンダ選択バルブ）
３１ａ、３２ａ、３３ａ、３４ａ操作レバー（選択レバー）
３９出入切替バルブ（シリンダ駆動制御バルブ）
３９ａ操作レバー（駆動レバー）
４７第１油路
４８第２油路
４９第３油路
５０第４油路
５１第５油路
５１ａロッド接続油路
５１ｂ連通油路
５２第６油路（圧力低下手段）
５３第７油路（圧力低下手段）
５４第８油路
５６第１絞り
５７第２絞り
５８第３絞り
６０、７７パイロットライン
６１パイロットチェックバルブ（圧力低下手段）
６５、６６、７９パイロットチェックバルブ
６７ダブルパイロットチェックバルブ
７１電磁バルブ（油路開閉バルブ）
７３コントローラ（バルブ作動制御手段）
７５中立位置センサ（中立検出手段）
８５プレート
Ｐ油圧ポンプ（油圧供給源）[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vehicle body lifting support device, and more specifically, includes a projecting beam that can project and move in the vehicle width direction, and a jack that is attached to the tip of the projecting beam and can be vertically expanded and contracted. The present invention relates to a vehicle body lifting support device including a plurality of outrigger devices arranged on the side of the vehicle body.
[0002]
[Prior art]
An aerial work platform uses an aerial work device mounted on the vehicle body to move the work platform to a desired height location so that workers on the work platform can perform work at height. If the work table is moved to a high place, the overturning moment acting on the vehicle body side increases and the vehicle body support tends to become unstable. For this reason, the conventional aerial work vehicle is configured to have an overhanging beam that can project and move in the vehicle width direction, and a jack that is attached to the tip of the overhanging beam and can be expanded and contracted vertically. Some have a vehicle body lifting support device having a plurality of outrigger devices disposed on the side of the vehicle body.
[0003]
As shown in FIG. 10, the vehicle body lifting support device is provided corresponding to each of the plurality of outrigger devices 21 and the outrigger device 21, and selectively supplies oil to the overhang cylinder 27 and the jack cylinder 24. A plurality of selector valves 31, 32, 33, and 34, and an inlet / outlet switching valve 39 that controls supply and discharge of oil from a hydraulic pump (not shown) to the selector valves 31, 32, 33, and 34. ing. The input / output switching valve 39 and the selector valves 31, 32, 33, 34 are connected by a first oil passage 47, and the selector valve 31, 32, 33, 34 and the bottom chamber 27a of the jack cylinder 27 are connected by a second oil passage 48. The rod chamber 27 b of the cylinder 27 and the access switching valve 39 are connected by a third oil passage 49. The selector valves 31, 32, 33, 34 and the bottom chamber 24 a of the extension cylinder 24 are connected by a fourth oil passage 50, and the rod chamber 24 b of the extension cylinder 24 and the third oil passage 49 are connected by a fifth oil passage 51. It is connected.
[0004]
Pilot check valves 65 and 66 are disposed corresponding to the second oil passage 48 and the third oil passage 49, respectively. These pilot check valves 65 and 66 allow the flow of oil to the jack cylinder 27 side, regulate the flow of oil to the selector valves 31, 32, 33, 34 side and the input / output switching valve 39 side, and When the pilot pressure of the oil path upstream of the pilot check valves 65 and 66 disposed on the upstream side of the oil flowing through the second oil path 48 and the third oil path 49 is received, the pilot check valve disposed on the downstream side The so-called double pilot check valve 67 is configured to allow the flow of oil to the selector valves 31, 32, 33, 34 side and the input / output switching valve 39 side by opening 65, 66.
[0005]
In order to ground the jack by extending the jack 27 of the outrigger device 21 indicated by the arrow A in FIG. 10 by such a vehicle body lifting support device, first, the operation lever 34a of the selector valve 34 is operated to the jack side. To do. Subsequently, the operation lever 39a of the access switching valve 39 is operated to the extension side. When the operation lever 39a is operated to the extension side, oil discharged from a hydraulic pump (not shown) is supplied to the bottom chamber 27a of the jack cylinder 27 through the input / output switching valve 39, the selector valve 34, and the second oil passage 48. Is done. At the same time, the pilot check valve 66 disposed in the third oil passage 49 receives the pilot pressure in the second oil passage 48 and opens. As a result, the jack cylinder 27 extends. When the jack is grounded and the operation lever 39a of the input / output switching valve 39 is operated to the neutral position, the supply of oil to the jack cylinder 27 is cut off and the jack is maintained in the grounded state.
[0006]
[Problems to be solved by the invention]
Here, when the operator mistakenly operates the operation lever 31a of the selector valve 31 (for example, the valve indicated by the arrow B in FIG. 10) different from the selector valve 34 described above, the second oil passage 48 is opened. The hydraulic pressure in the second oil passage 48 closer to the selector valve 34 than the disposed pilot check valve 65 and the third oil closer to the on / off switching valve 39 than the pilot check valve 66 disposed in the third oil passage 49. If the hydraulic pressure in the passage 49 is high, the double pilot check valve 65 may be opened and the second oil passage 48 and the third oil passage 49 may be in communication.
[0007]
In such a case, the oil in the second oil passage 48 is caused by the first operation of the selector valve 34, the first oil passage 47, the erroneously operated selector valve 31 and the erroneously operated selector valve 31 and the overhang indicated by the arrow C in FIG. The oil passes through a fourth oil passage 50 connecting the cylinder 24 and is supplied to the bottom chamber 24 a of the overhang cylinder 24. On the other hand, since the pilot check valve 66 disposed in the third oil passage 49 is in an open state, the rod chamber 24b of the overhanging cylinder 24 is connected to the rod chamber 27b of the jack cylinder 27 of the outrigger device 21 indicated by the arrow A. It becomes a state of communication. As a result, the overhang cylinder 24 and the jack cylinder 27 constitute a closed circuit, and there is a problem that the overhang cylinder 24 expands while the jack cylinder 27 contracts while the in / out switch 39 is in a neutral state. Arise.
[0008]
The present invention has been made in view of such a problem, and an object of the present invention is to provide a vehicle body lifting support device that does not expand and contract an overhang cylinder or a jack cylinder even if a selector valve is erroneously operated.
[0009]
[Means for Solving the Problems]
In order to solve the above-described problems, a vehicle body lifting support device according to the present invention includes an overhanging beam that can be extended in the vehicle width direction, an overhanging cylinder that projects and moves the overhanging beam in the vehicle width direction, and an overhanging beam. A plurality of outrigger devices disposed on the side of the vehicle body, and each of the outrigger devices. A plurality of cylinder selection valves (for example, selector valves 31, 32, 33, 34 in the embodiment) provided correspondingly and selectively supplying oil to the overhang cylinder and the jack cylinder, and a hydraulic pressure supply source (for example, The cylinder drive control valve (for example, the input / output switching valve 3 in the embodiment) that controls the supply and discharge of oil from the hydraulic pump P) in the embodiment to the cylinder selection valve. ), A first oil passage that connects the cylinder drive control valve and the cylinder selection valve, a second oil passage that connects the cylinder selection valve and the bottom chamber of the jack cylinder, the rod chamber of the jack cylinder, and the cylinder drive control A third oil passage connecting the valve, a fourth oil passage connecting the cylinder selection valve and the bottom chamber of the extension cylinder, and a fifth oil passage connecting the rod chamber of the extension cylinder and the third oil passage. The pilot check valve has a pilot check valve corresponding to each of the second oil path and the third oil path. The pilot check valve allows the oil to flow to the jack cylinder side, and the cylinder selection valve side and the cylinder drive control valve side. When the pilot pressure of the oil passage upstream from the pilot check valve disposed upstream of the oil flowing through the second oil passage and the third oil passage is received, Car body lifting comprising a pilot check valve disposed on the flow side and a double pilot check valve configured to open and allow oil flow to the cylinder selection valve side and the cylinder drive control valve side In the support device, the cylinder drive control valve is configured to shut off the oil supply to the cylinder selection valve in the neutral state, and the second oil path and the third oil when the cylinder drive control valve is switched to the neutral state. Pressure reducing means for reducing the oil pressure in the passage (for example, the sixth oil passage 52, the seventh oil passage 53, and the pilot check valve 61 in the embodiment) is provided.
[0010]
According to the vehicle body lifting support device having the above configuration, the cylinder selection valve is operated to the jack side, oil is supplied to the jack cylinder of the outrigger device via the cylinder drive control valve, and the jack is extended to be in a ground state. When the cylinder drive control valve is switched to the neutral state, if a cylinder selection valve that is different from the cylinder selection valve that was operated first is accidentally operated to the overhang side, the second oil passage and the third oil passage The hydraulic pressure is reduced. For this reason, the double pilot check valve disposed in the second oil passage and the third oil passage connected to the extended jack cylinder is in a state in which the oil flow to the cylinder selection valve side and the cylinder drive control valve side is restricted. As a result, even if the second oil passage connected to the extended jack cylinder communicates with the bottom chamber of the extension cylinder connected thereto via the erroneously operated cylinder selection valve, The hydraulic pressure to move is not applied. Further, since the reduction movement of the jack cylinder is restricted by the pilot check valve disposed in the second oil passage, the oil in the rod chamber of the overhang cylinder does not flow out to the jack cylinder side. For this reason, it is possible to prevent a situation in which the jack cylinder is reduced and the extension cylinder is extended.
[0011]
In the vehicle body lifting support device having the above configuration, the pressure reducing means connects the first oil passage and the tank, and connects the sixth oil passage having the first throttle, the third oil passage, and the tank. The pilot line is connected to the eighth oil passage which is disposed in the seventh oil passage having the second throttle, the sixth oil passage and the seventh oil passage and which connects the oil supply source and the cylinder drive control valve. The oil in the second oil passage and the third oil passage is released by receiving the pilot pressure of the oil flowing through the eighth oil passage through the pilot line and releasing the restriction of the oil flow to the tank side. May be configured to have a pilot check valve that flows into the tank through the sixth oil passage and the seventh oil passage.
[0012]
According to the vehicle body lifting support device having the above-described configuration, when the cylinder drive control valve is switched to the neutral state, the pilot check valve receives the pilot pressure of the oil flowing in the eighth oil passage and receives the sixth oil passage and the seventh oil passage. Release the restriction of oil flow to the tank side. For this reason, the second oil passage and the third oil passage communicate with the tank via the sixth oil passage, the seventh oil passage and the pilot check valve. As a result, the oil pressure in the second oil passage and the third oil passage is reduced. If the state is high, the hydraulic pressure can be reduced with a simple configuration.
[0013]
In the vehicle body lifting support device having the above-described configuration, the pressure reduction means includes neutral detection means (for example, the neutral position sensor 75 in the embodiment) for detecting whether or not the cylinder drive valve is in a neutral state, and a first oil passage. It is arranged in the 6th oil passage connecting between the tank, the 7th oil passage connecting between the 3rd oil passage tank, the 6th oil passage, and the 7th oil passage, and these oil passages are connected or intercepted. The oil passage opening / closing valve (for example, the electromagnetic valve 71 in the embodiment) and the neutral detection means detect that the cylinder drive valve is in the neutral state, and operate the oil passage opening / closing valve to You may comprise and comprise the valve | bulb action control means (for example, controller 73 in embodiment) which connects 7 oil paths.
[0014]
According to the vehicle body lifting support device having the above-described configuration, when the cylinder drive control valve is switched to the neutral state, the valve operation control means operates the oil passage opening / closing valve, and the oil passage opening / closing valve functions as the sixth oil passage and the seventh oil passage. Put the road in communication. For this reason, the second oil passage and the third oil passage communicate with the tank via the sixth oil passage, the seventh oil passage and the oil passage opening / closing valve, and as a result, the hydraulic pressure in the second oil passage and the third oil passage. If the state is high, the oil pressure can be reliably reduced. Note that the valve operation control means operates the oil passage opening / closing valve for a predetermined time (time for the pressure to be released) from when the cylinder drive control valve is switched to the neutral state to open the sixth oil passage and the seventh oil passage. You may make it be a communication state.
[0015]
The vehicle body lifting support device according to the present invention is attached to a protruding beam that can be extended in the vehicle width direction, a protruding cylinder that projects and moves the protruding beam in the vehicle width direction, and a tip of the protruding beam. A plurality of outrigger devices on both the left and right sides of the vehicle body, each of which is provided corresponding to the outrigger device, There are a plurality of cylinder selection valves for selectively supplying oil to the jack cylinder, and a cylinder drive control valve for controlling supply and discharge of oil from the hydraulic supply source to the cylinder selection valve. A first oil passage that connects the valve, a second oil passage that connects the cylinder selection valve and the bottom chamber of the jack cylinder, a rod chamber of the jack cylinder, and a cylinder drive A third oil passage connecting the control valve, a fourth oil passage connecting the cylinder selection valve and the bottom chamber of the extension cylinder, and a fifth oil passage connecting the rod chamber of the extension cylinder and the third oil passage. Has a pilot check valve corresponding to each of the second oil path and the third oil path, and the pilot check valve allows the oil flow to the jack cylinder side, the cylinder selection valve side and the cylinder drive control valve When the pilot pressure in the oil passage upstream of the pilot check valve disposed upstream of the oil flowing through the second oil passage and the third oil passage is received, And a double pilot check valve configured to allow the flow of oil to the cylinder selection valve side and the cylinder drive control valve side by opening the disposed pilot check valve. In the vehicle body lifting support device, the cylinder drive control valve is configured to shut off the oil supply to the cylinder selection valve in the neutral state, and the fifth oil passage is a rod that connects the rod chambers of the plurality of overhang cylinders. An eighth oil passage having a connection oil passage and a communication oil passage communicating with the rod connection oil passage and connected to the third oil passage and disposed in the communication oil passage and connecting the oil supply source and the cylinder drive control valve. The pilot line is connected to allow the oil flow to the overhanging cylinder side, restrict the oil flow to the cylinder drive valve side, and flow through the eighth oil passage when the cylinder drive valve is in the neutral state Even if the pilot pressure is received through the pilot line, a pilot check valve that restricts the flow of oil to the cylinder drive valve side is provided.
[0016]
According to the vehicle body lifting support device having the above configuration, the cylinder selection valve is operated to the jack side, oil is supplied to the jack cylinder of the outrigger device via the cylinder drive control valve, and the jack is extended to be in a ground state. When the cylinder drive control valve is switched to the neutral state, if a cylinder selection valve different from the cylinder selection valve that was operated first is accidentally operated to the extension side, the fifth oil passage to the third oil passage The oil flow is cut off. For this reason, the second oil passage connected to the extended jack cylinder communicates with the bottom chamber of the extension cylinder connected to the erroneously operated cylinder selection valve. In addition, since the fifth oil passage connected to the rod chamber of the overhanging cylinder is in a closed state, the extension movement of the overhanging cylinder can be prevented. Further, since no oil flows from the fifth oil passage to the third oil passage, it is possible to prevent the expansion movement of the jack cylinder that has been extended.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described with reference to FIGS. This embodiment shows an aspect of an aerial work vehicle having a work table at the tip of a boom configured to be able to undulate and turn on the vehicle body and extend and retract.
[0020]
[First Embodiment]
First, before describing the first embodiment of the vehicle body lifting support apparatus according to the present invention, an aerial work vehicle equipped with the vehicle body lifting support apparatus will be described. As shown in FIG. 1, the aerial work vehicle 1 is configured with a truck vehicle as a base, and has a driving cabin 5 at the front portion of the vehicle body 3, and a turn built in the vehicle body 3 at the rear portion of the vehicle body 3. A swivel 7 that is driven by a motor (not shown) and configured to be horizontally swivelable is disposed. A boom 9 pivoted at the base end is attached to the upper part of the swivel base 7, and this boom 9 is provided by a telescopic cylinder 11 built in a base type boom 9 a, an intermediate boom 9 b, and a tip boom 9 c in a nested manner. It is configured to be expanded and contracted. The boom 9 is configured to be movable up and down by a hoisting cylinder 13. A work table 15 that is held in a horizontal state regardless of the movement of the boom 9 is attached to the tip of the tip boom 9c.
[0021]
Next, the vehicle body lifting support device will be described with reference to FIGS. The vehicle body lifting support device 20 is disposed on the left and right side portions of the vehicle front and rear on the vehicle rear side with respect to the driving cabin 5, and an outrigger device 21 that lifts and supports the vehicle, and an operation device 30 that operates the drive of the outrigger device 21. It is comprised. The outrigger device 21 is provided on both the left and right sides of the front and rear of the vehicle on the vehicle rear side of the driving cabin 5 and is configured to extend in the vehicle width direction, and the extension beam 23 in the vehicle width direction. A protruding cylinder 24 that protrudes and moves, a jack 26 that is attached to the distal end portion of the protruding beam 23 and can be vertically expanded and contracted, and a jack cylinder 27 that expands and contracts the jack 26 are configured. The jack 26 includes an outer post 26a vertically attached to the tip of the overhanging beam 23, an inner post 26b configured to protrude into the outer post 26a, and an outer post 26a built in these posts. The above-described jack cylinder 27 for projecting and moving the inner post 26b is provided.
[0022]
The operating device 30 for operating the driving of the outrigger device 21 is disposed at the rear of the vehicle and includes four selector valves 31, 32, 33, and 34 and one in / out switching valve 39. A panel 43 having a through hole 41 through which the bases of all the levers of the five operation levers 31a, 32a, 33a, 34a, 39a are inserted is disposed on the front surface of the operation device 30. The selector valves 31, 32, 33, and 34 are provided corresponding to the outrigger devices 21, respectively, and have a function of selectively supplying oil to the overhang cylinder 24 and the jack cylinder 27. It is a switching valve with a manual detent, and has the aforementioned operation levers 31a, 32a, 33a, 34a that can be tilted back and forth from the neutral position. When the operation levers 31a, 32a, 33a, 34a are tilted to one of the front and rear sides, the selector valves 31, 32, 33, 34 supply oil to the jack cylinder 27, and the operation levers 31a, 32a, 33a, 34a The selector valves 31, 32, 33, and 34 are configured to supply oil to the overhanging cylinder 24 when the valve is tilted to either the front or rear side.
[0023]
On the other hand, the entry / exit switching valve 39 has a function of controlling supply / discharge of oil from the hydraulic pump P to the selector valves 31, 32, 33, 34, and is a 6-port 3-position switching valve with a manual detent. The operation lever 39a described above can be tilted back and forth. When the operation lever 39a is tilted to one of the front and rear sides, the input / output switching valve 39 supplies oil in a direction in which the jack cylinder 27 or the extension cylinder 24 is extended, and the operation lever 39a is moved to either the front or rear side. When the tilting operation is performed, the in / out switching valve 39 is configured to supply oil in a direction in which the jack cylinder 27 or the overhanging cylinder 24 is contracted.
[0024]
As shown in FIG. 4B, the four selector valves 31 to 34 and the entry / exit switching valve 39 are arranged in the vehicle width direction, and are arranged on the leftmost side (lower side in FIG. 4). The provided selector valve 31 is a valve corresponding to the outrigger device 21 disposed on the left front side of the vehicle, and the selector valve 32 disposed on the right side of the selector valve 31 is disposed on the left rear side of the vehicle. A valve corresponding to the outrigger device 21 and disposed on the right side of the selector valve 32 (a central valve) is an input / output switching valve 39. Further, the selector valve 33 disposed on the right side of the access switching valve 39 is a valve corresponding to the outrigger device 21 disposed on the right front side of the vehicle. The selector valve 34 disposed on the right side of the selector valve 33 is It is a valve corresponding to the outrigger device 21 disposed on the right rear side of the vehicle.
[0025]
Here, the hydraulic circuit including the selector valve 34 and the in / out switching valve 39 of the outrigger device 32 disposed on the right rear side of the vehicle will be described with reference to FIG. Selector valve34As shown in FIG. 3, it is connected to the inlet / outlet switching valve 39 via the first oil passage 47, connected to the bottom chamber 27a of the jack cylinder 27 via the second oil passage 48, and further to the fourth oil passage 50. Is connected to the bottom chamber 24a of the overhanging cylinder 24. The in / out switching valve 39 is connected to the rod chamber 27 b of the jack cylinder 27 through the third oil passage 49 and is connected to the hydraulic pump P through the eighth oil passage 54. The rod chamber 24b of the overhang cylinder 24 is connected to the third oil passage 49 via the fifth oil passage. Pilot check valves 65 and 66 are provided corresponding to the second oil passage 48 and the third oil passage 49, respectively, and the pilot check valves 65 and 66 allow the oil to flow to the jack cylinder 27 side, and The flow of oil to the valve 34 side and the in / out switching valve 39 side is restricted, and upstream of the pilot check valves 65 and 66 disposed on the upstream side of the oil flowing through the second oil passage 48 and the third oil passage 49. When the pilot pressure of the oil passage on the side is received, the pilot check valves 65 and 66 disposed on the downstream side are released to allow the oil flow to the selector valve 34 side and the input / output switching valve 39 side. Is configured.
[0026]
A sixth oil passage 52 having a first restriction 56 is connected between the first oil passage 47 and the tank T, and a seventh oil having a second restriction 57 is provided between the third oil passage 49 and the tank T. Road 53 is connected. The sixth oil passage 52 and the seventh oil passage 53 merge on the tank T side to form one oil passage.
[0027]
The merged sixth oil passage 52 and seventh oil passage 53 are provided with a pilot line 60 having a third throttle 58 connected to the eighth oil passage 54, and the pilot pressure of the oil flowing through the eighth oil passage 54 is obtained. There is provided a pilot check valve 61 that is received via the pilot line 60 and releases the restriction of the oil flow to the tank T side.
[0028]
Note that the hydraulic circuit of the outrigger device 21 disposed in front of the vehicle, the hydraulic circuit of the outrigger device 21 disposed in the rear left of the vehicle, and the hydraulic circuit of the outrigger device 21 disposed in the front left of the vehicle are described above. Since it conforms to the hydraulic circuit of the arranged outrigger device 21, the same reference numerals are given to the same mode portions, and the description thereof is omitted. As a result, the four selector valves 31 to 34 and the in / out switching valve 39 form the hydraulic circuit shown in FIG. In the hydraulic circuit shown in FIG. 2, an unload valve 63 is provided in the eighth oil passage 54 through which oil discharged from the hydraulic pump P flows. This valve returns the excess oil to the tank T so that the oil pressure in the eighth oil passage 54 is maintained at a predetermined pressure when the inlet / outlet switching valve 39 is neutralized and the oil supply / discharge control is stopped. It has a function.
[0029]
Now, in the vehicle body lifting support device 20 having the above-described configuration, as shown in FIG. 2, the jack of the outrigger device 21 (the outrigger device 21 indicated by the arrow A in FIG. 2) on the right rear side of the vehicle is extended and grounded. First, the operation lever 34a of the selector valve 34 is operated to the jack side (upper side in FIG. 2). Subsequently, the operation lever 39a of the entry / exit switching valve 39 is operated to the extension side (upper side in FIG. 2). When the operation lever 39a is operated to the extension side, the oil discharged from the hydraulic pump P passes through the eighth oil passage 54, the in / out switching valve 39, the first oil passage 47, the selector valve 34, and the second oil passage 48 and is jacked. It is supplied to the bottom chamber 27 a of the cylinder 27. At the same time, the pilot check valve 66 disposed in the third oil passage 49 receives the pilot pressure in the second oil passage 48 and opens. As a result, the third oil passage 49 is in communication, and the oil in the rod oil chamber 27b of the jack cylinder 27 can flow out into the tank T via the third oil passage 49 and the in / out switching valve 39. Expands. Then, when the jack 26 disposed on the right rear side of the vehicle shown in FIG. 1 is extended and grounded, and the operation lever 39a of the input / output switching valve 39 is operated to the neutral position, the supply of oil to the jack cylinder 27 is shut off. Thus, the jack 26 is maintained in a grounded state.
[0030]
In this state, for example, the operator erroneously operates the operation lever 31a of the selector valve 31 (for example, the valve indicated by the arrow B in FIG. 2) different from the selector valve 34 described above to the overhang side (lower side in FIG. 2). A description will be given assuming this case. Here, when the operation lever 31a is operated to the overhang side, the hydraulic pressure in the second oil passage 48 on the selector valve 34 side than the pilot check valve 65 disposed in the second oil passage 48, and the third When the hydraulic pressure in the third oil passage 49 on the side of the input / output switching valve 39 is higher than the pilot check valve 66 disposed in the oil passage 49, the double pilot check valve 66 is opened and the second oil passage 48 and The third oil passage 49 may be in a communication state.
[0031]
In such a case, the oil in the second oil passage 48 passes through the selector valve 34 that is operated first, the first oil passage 47, the selector valve 31 that is erroneously operated, and the fourth oil passage 50 that is connected to the selector valve 31 that is erroneously operated. Then, the oil is supplied to the bottom chamber 24a of the overhang cylinder 24 (cylinder indicated by arrow C in FIG. 2) connected to the fourth oil passage 50. On the other hand, the rod chamber 24b of the overhanging cylinder 24 has an outrigger device indicated by an arrow A because the pilot check valve 66 (the valve indicated by the arrow D in FIG. 2) disposed in the third oil passage 49 is in an open state. The jack chamber 27 is in communication with the rod chamber 27 b of the jack cylinder 27. As a result, the extension cylinder 24 and the jack cylinder 27 constitute a closed circuit, and the extension cylinder 24 extends and the extension cylinder 24 extends while the input / output switching valve 39 is in a neutral state. That is, the outrigger device 21 operates against the will of the operator who operates the operation device 30.
[0032]
However, in the vehicle body lifting support device 20 according to the present invention, when the in / out switching valve 39 is switched to the neutral state, the unload valve 63 reduces the hydraulic pressure in the eighth oil passage 54, and as a result, the sixth oil passage. The pilot check valve 61 provided in the oil passage 52 and the seventh oil passage 53 operates so as to restrict the flow of oil to the tank T side. The hydraulic pressure reduction speed between the pilot check valves 61 is slowed down. For this reason, there is a time difference from when the input / output switching valve 39 is switched to the neutral state until the oil flow to the tank T side by the pilot check valve 61 is completely shut off. As a result, during this time, the oil in the second oil passage 48 and the third oil passage 49 flows out into the tank T via the sixth oil passage 52, the seventh oil passage 57, and the pilot check valve 61, The oil pressure in the oil passage 48 and the third oil passage 49 decreases. Therefore, the double pilot check valve 67 disposed in the second oil passage 48 and the third oil passage 49 connected to the extended jack cylinder 27 (corresponding to the outrigger device 21 indicated by the arrow A) is a selector. The oil flow to the valve side 34 and the in / out switching valve 39 side is regulated. As a result, even if the second oil passage 48 connected to the extended jack cylinder 27 communicates with the bottom chamber 24a of the extension cylinder 24 (cylinder indicated by arrow C) connected to the erroneously operated selector valve 31, No hydraulic pressure is applied to the output cylinder 24 to extend it. Further, since the reduction movement of the jack cylinder 27 is restricted by the pilot check valve 65 disposed in the second oil passage 48, the oil in the rod chamber 24b of the overhang cylinder 24 flows out to the jack cylinder 27 side. do not do. For this reason, it is possible to prevent the jack cylinder 27 from contracting and the overhang cylinder 24 from extending.
[0033]
In the above-described embodiment, the case where the selector valve 31 corresponding to the outrigger device 21 at the front left of the vehicle is erroneously operated has been described. However, the present invention is not limited to this. When the selector valves 33 and 32 are erroneously operated, the same effect as described above is produced.
[0034]
In the above-described embodiment, the pilot check valve 61 is provided in the sixth oil passage 52 and the seventh oil passage 53. However, as shown in FIG. 5, an electromagnetic valve 71 may be provided instead. . The solenoid valve 71 is a three-port two-position switching valve. When the solenoid 71a is energized, the sixth oil passage 52 and the seventh oil passage 53 are brought into communication to allow the oil to flow to the tank T side. When the solenoid 71a is brought into a non-excited state, the sixth oil passage 52 and the seventh oil passage 53 are shut off, and the flow of oil to the tank T side is shut off. The operation control of the electromagnetic valve 71 is performed by the controller 73. The controller 73 is electrically connected to a neutral position sensor 75 attached to the entry / exit switching valve 39, and the controller 73 receives a neutral signal from the neutral position sensor 75 indicating that the entry / exit switching valve 39 is in the neutral position. In some cases, the solenoid 71a of the electromagnetic valve 71 is excited.
[0035]
By configuring in this way, when the in / out switching valve 39 is switched to the neutral state, the oil pressure in the second oil passage 52 and the third oil passage 53 can be reduced as in the case of the pilot check valve 61 described above. In addition, the jack cylinder 27 can be reduced and the extension cylinder 24 connected to the erroneously operated selector valve 31 can be prevented from extending. Further, the neutral state of the entry / exit switching valve 39 is detected by the neutral position sensor 75, and the electromagnetic valve 71 is operated in accordance with the information of this sensor, so that the opening control of the second oil passage 52 and the third oil passage 53 can be reliably performed. It can be done quickly. The controller 73 operates the electromagnetic valve 71 for a predetermined time (time for the pressure to be released) from the time when the input / output switching valve 39 is switched to the neutral state to bring the sixth oil passage and the seventh oil passage into communication. You may make it do. By doing so, it is possible to prevent the extension cylinder 24 from extending when a force in the extension direction is applied to the extension cylinder 24.
[0036]
[Second Embodiment]
Next, a second embodiment of the vehicle body lifting support device 20 will be described. In the second embodiment, only differences from the first embodiment will be described, and the same reference numerals will be given to the same aspects as those in the first embodiment, and the description thereof will be omitted. As shown in FIG. 6, the fifth oil passage 51 communicates with the rod connection oil passage 51a that connects the rod chambers 24b of the extension cylinders 24 of the four outrigger devices 21, and the rod connection oil passage 51a. And a communication oil passage 51 b connected to the third oil passage 49. The communication oil passage 51b is connected with a pilot line 77 to the eighth oil passage 54 to allow the oil flow to the overhanging cylinder 24 side, restrict the oil flow to the ingress / egress switching valve 39 side, and switch in / out. A pilot check valve 79 is provided that restricts the flow of oil to the inlet / outlet switching valve 39 side even when the pilot pressure of the oil flowing through the eighth oil passage 54 is received via the pilot line 77 when the valve 39 is in the neutral state. ing.
[0037]
According to the vehicle body lifting support device 20 having the above-described configuration, the selector valve 34 corresponding to the outrigger device 21 on the right rear side of the vehicle is operated to the jack side, so that the oil is supplied to the outrigger device 32 indicated by the arrow A via the input / output switching valve 39. When the jack 26 shown in FIG. 1 is supplied to the jack cylinder 27 to move to the grounded state and the input / output switching valve 39 is switched to the neutral state, the selector valve 31 different from the selector valve 34 that was initially operated is If the oil pressure is accidentally operated to the overhang side, the oil pressure in the eighth oil passage 54 is lowered, and the pilot check valve 79 blocks the oil flow from the fifth oil passage 51 to the third oil passage 49. Therefore, the second oil passage 48 connected to the extended jack cylinder 27 of the outrigger device 21 indicated by the arrow A communicates with the bottom chamber 24a of the overhanging cylinder 24 indicated by the arrow C connected to the selector valve 31 that has been erroneously operated. , This overhang cylinder 24Direction to extendEven if the oil pressure of the extension cylinder 24 acts on the extension cylinder 24, the fifth oil passage 51 connected to the rod chamber 24b of the extension cylinder 24 is in a closed state, so that the extension movement of the extension cylinder 24 is restricted. Can do. Further, since no oil flows from the fifth oil passage 51 to the third oil passage 4, the reduction movement of the jack cylinder 27 in which the outrigger device 32 is extended as indicated by the arrow A can be restricted.
[0038]
Thus, the vehicle body lifting support device 20 of the second embodiment is in a state where the hydraulic pressure in the second oil passage 48 and the third oil passage 49 is high when the in / out switching valve 39 is switched to the neutral state. Even if it exists, this hydraulic pressure is not lowered, but the extension movement of the overhanging cylinder 24 is restricted. For this reason, means for lowering the hydraulic pressure is not required, and the configuration of the hydraulic circuit can be simplified.
[0039]
[Third Embodiment]
Next, a third embodiment of the vehicle body lifting support device 20 will be described. In the third embodiment, only differences from the first embodiment will be described, and the same reference numerals will be given to the same aspects as those in the first embodiment, and the description thereof will be omitted. The vehicle body lifting support device 20 of the third embodiment does not have the sixth oil passage 53 and the seventh oil passage 54 in the hydraulic circuit shown in FIG. 2, and is the same as the conventional hydraulic circuit shown in FIG. It is. Further, as shown in FIG. 7, on the back side of the panel 43 disposed on the front surface of the operating device 30, plate support members 83 extending vertically on the outer sides of the left and right ends of the through hole 41 are disposed. A plate 85 is mounted between the plate support members 83 so as to be movable up and down.
[0040]
8 and 9 will be further described. The plate 85 has a rectangular shape extending in the left-right direction (vertical direction in FIG. 8), and a rectangular insertion hole 87 extending in the left-right direction is formed in the central portion. Yes. As shown in FIG. 9A, the width X1 in the left-right direction of the insertion hole 87 is a pair of operation levers 31a disposed on the outermost side among the five operation levers 31a, 32a, 39a, 33a, 34a arranged side by side. , 34a has a dimension larger than the distance X0. The vertical width Y0 of the insertion hole 87 is substantially the same as the width between the position when the operation lever 31a, 32a, 33a, 34a is tilted back and forth from the neutral position and the neutral position. have. However, the width Y1 in the vertical direction at the central portion of the insertion hole 87 corresponding to the portion where the drive lever 39a is disposed is such that the operation lever 39a is positioned in the insertion hole 87 regardless of the positions of the operation levers 31a, 32a, 33a, 34a. It has a width that does not contact the end, for example, a width that is substantially the same as the movable width of the operation lever 39a. Further, the width X2 in the left-right direction at the central portion of the insertion hole 87 corresponding to the portion where the operation lever 39a is disposed has a larger dimension than the width in the left-right direction of the operation lever 39a.
[0041]
In the operation device having the above-described configuration, for example, the operation lever 39a shown in FIG. 9A and the operation levers 32a and 33a adjacent to the left and right of the lever are in the neutral position, and the operation levers 31a and 34a disposed at both the left and right ends. When the operation lever 32a adjacent to the left side of the operation lever 39a is erroneously operated and tilted to the rear side, as shown in FIG. 9B, the operation lever is tilted to the rear side. The plate 85 moves to the rear side by 32a. At the same time, the upper end portions of the insertion holes 87 push the operation levers 31a and 34a provided at both left and right end portions to the rear side, and these operation levers 31a and 34a move to the neutral position. For this reason, even when the other operation lever 32a is operated in a direction different from the tilt direction of the operation levers 31a and 34a that have already been tilted, it is possible to prevent a situation in which operation levers having different tilt directions are mixed.
[0042]
As a result, as shown in FIG. 10 of the prior art described above, the selector valve 34 is operated to the jack side, the access control valve 39 is operated to the expansion side, the jack cylinder 27 is expanded, and the jack 26 is grounded. If the extension cylinder 24 connected to the other selector valve 31 is extended when the other selector valve 31 is operated to the extension side after the input / output switching valve 39 is operated to the neutral state, FIG. If it demonstrates in addition, if the operating device 30 provided with the plate 85 is used, if the other selector valve 31 operated later is operated to the extension side, the operating lever of the selector valve 34 that has already been operated. 34a moves to the neutral position. For this reason, since the second oil passage 48 and the first oil passage 47 are cut off, the hydraulic pressure does not act on the extension cylinder 24 connected to the other selector valve 31 operated later. 24 does not expand, and the jack cylinder 27 connected to the selector valve 34 already operated does not contract.
[0043]
In this way, it is economical because it is possible to prevent the cylinder from being driven against the operator's will by simply providing the operating device 30 with the plate 85.
[0044]
【The invention's effect】
As described above, according to the vehicle body lifting support device of the present invention, by providing the oil pressure lowering means for lowering the oil pressure in the second oil passage and the third oil passage, the jack extends and becomes in a grounded state. When the cylinder drive control valve is switched to the neutral state, even if a cylinder selection valve that is different from the cylinder selection valve that was operated first is erroneously operated to the extension side, the hydraulic pressure lowering means is connected to the second oil passage and the third oil passage. Since the oil pressure of the oil passage is reduced, the oil pressure does not act on the extension cylinder that is connected to the cylinder selection valve that has been operated incorrectly, so that the extension cylinder can be prevented from extending and the jack of the jack in the grounded state can be prevented. Cylinder contraction can be prevented.
[0045]
Further, according to the vehicle body lifting support device of the present invention, the fifth oil passage is connected to the third oil passage by communicating with the rod connection oil passage and the rod connection oil passage that connect the rod chambers of the plurality of extending cylinders. It is configured to have a communication oil passage, and by providing a pilot check valve in the communication oil passage, the jack is extended and grounded, and when the cylinder drive control valve is switched to the neutral state, it is operated first. If a cylinder selection valve that is different from the selected cylinder selection valve is accidentally operated to the overhang side, the oil flow from the fifth oil passage to the third oil passage will be shut off, leading to the erroneously operated cylinder selection valve. Even if the extension cylinder is extended and the hydraulic pressure in the direction is applied, the fifth oil passage connected to the rod chamber of the extension cylinder is in the closed state, so that the extension movement of the extension cylinder can be restricted. . Further, since no oil flows from the fifth oil passage to the third oil passage, it is possible to prevent the jack cylinder of the jack in a grounded state from being reduced.
[Brief description of the drawings]
FIG. 1 is a perspective view of an aerial work vehicle equipped with a vehicle body lifting support device according to a first embodiment of the present invention.
Show.
FIG. 2 is a hydraulic circuit diagram of the vehicle body lifting support device according to the first embodiment of the present invention.
FIG. 3 is a hydraulic circuit diagram of a part of the vehicle body lifting support device according to the first embodiment of the present invention.
FIG. 4 shows the operating device according to the first embodiment of the present invention, in which FIG. 4 (a) is a plan view of the operating device.
FIG. 4B is a side view of the operating device.
FIG. 5 is a hydraulic circuit diagram of the vehicle body lifting support device according to the first embodiment of the present invention.
FIG. 6 is a hydraulic circuit diagram of a vehicle body lifting support device according to a second embodiment of the present invention.
FIG. 7 shows an operating device according to a third embodiment of the present invention. FIG. 7 (a) is a plan view of the operating device.
FIG. 4B is a side view of the operating device.
FIG. 8 is a plan view of a plate of an operating device according to a third embodiment of the present invention.
FIG. 9 is a diagram for explaining the operation of the operating device according to the third embodiment of the present invention.
FIG. 10 is a hydraulic circuit diagram of a vehicle body lifting support device in the prior art.
[Explanation of symbols]
20 Car body lifting support device
21 Outrigger device
23 Overhang beam
23 Overhang cylinder
26 Jack
27 Jack cylinder
31, 32, 33, 34 Selector valve (Cylinder selection valve)
31a, 32a, 33a, 34a Operation lever (selection lever)
39 In / out switching valve (cylinder drive control valve)
39a Operation lever (drive lever)
471st oil passage
48Second oil passage
493rd oil passage
504th oil passage
515th oil passage
51a Rod connection oil passage
51b Communication oil passage
52 6th oil passage (Pressure drop means)
53 7th oil passage (Pressure drop means)
54 Oil Route 8
56 First aperture
57 Second aperture
58 3rd aperture
60, 77 Pilot line
61 Pilot check valve (pressure reduction means)
65, 66, 79 Pilot check valve
67 Double pilot check valve
71 Solenoid valve (oil passage opening / closing valve)
73 Controller (valve operation control means)
75 Neutral position sensor (neutral detection means)
85plate
P Hydraulic pump (hydraulic supply source)

Claims

A projecting beam that can project in the vehicle width direction, a projecting cylinder that projects and moves the projecting beam in the vehicle width direction, a jack that is attached to the tip of the projecting beam and can be expanded and contracted vertically; A plurality of outrigger devices arranged on the side of the vehicle body, the jack cylinder configured to extend and retract the jack;
A plurality of cylinder selection valves provided corresponding to the outrigger devices, respectively, for selectively supplying oil to the overhang cylinder and the jack cylinder;
A cylinder drive control valve for controlling supply and discharge of oil from a hydraulic supply source to the cylinder selection valve;
A first oil passage connecting the cylinder drive control valve and the cylinder selection valve; a second oil passage connecting the cylinder selection valve and a bottom chamber of the jack cylinder; the rod chamber of the jack cylinder; and the cylinder drive control. A third oil passage connecting the valve, a fourth oil passage connecting the cylinder selection valve and the bottom chamber of the extension cylinder, and a fifth oil connecting the rod chamber of the extension cylinder and the third oil passage. Road and
A pilot check valve disposed corresponding to each of the second oil passage and the third oil passage, the pilot check valve allowing oil to flow to the jack cylinder side; An oil passage upstream of the pilot check valve disposed on the upstream side of the oil flowing through the second oil passage and the third oil passage while restricting the flow of oil to the cylinder drive control valve side A double pilot check valve configured to open a pilot check valve disposed on the downstream side when the pilot pressure is received to allow oil to flow to the cylinder selection valve side and the cylinder drive control valve side; In the vehicle body lifting support device comprising:
The cylinder drive control valve is configured to shut off oil supply to the cylinder selection valve in a neutral state;
A vehicle body lifting support device comprising pressure reducing means for reducing the hydraulic pressure in the second oil passage and the third oil passage when the cylinder drive control valve is switched to a neutral state.

The pressure drop means is
A sixth oil passage connecting the first oil passage and the tank and having a first throttle;
A seventh oil passage connecting the third oil passage and the tank and having a second throttle;
A pilot line is connected to an eighth oil passage that is disposed in the sixth oil passage and the seventh oil passage and connects the hydraulic pressure supply source and the cylinder drive control valve, and has a third throttle in the pilot line, The pilot pressure of the oil flowing in the eighth oil passage is received via the pilot line, the restriction of the oil flow to the tank side is released, and the oil in the second oil passage and the third oil passage is sent to the first oil passage. 2. The vehicle body lifting support device according to claim 1, further comprising a pilot check valve that flows into the tank through the six oil passages and the seventh oil passage.

The pressure drop means is
Neutral detection means for detecting whether or not the cylinder drive control valve is in a neutral state;
A sixth oil passage connecting the first oil passage and the tank;
A seventh oil passage connecting the third oil passage and the tank;
An oil passage opening / closing valve disposed in the sixth oil passage and the seventh oil passage and communicating or blocking these oil passages;
Valve operation control means for operating the oil passage opening / closing valve to connect the sixth oil passage and the seventh oil passage when the neutrality detection means detects that the cylinder drive control valve is in a neutral state; The vehicle body lifting apparatus according to claim 1, comprising:

A projecting beam that can project in the vehicle width direction,
A projecting cylinder for projecting and projecting the projecting beam in the vehicle width direction; a jack attached to a distal end of the projecting beam and capable of expanding and contracting vertically; and a jack cylinder for expanding and contracting the jack. A plurality of outrigger devices are arranged on the left and right sides of the vehicle body,
A plurality of cylinder selection valves provided corresponding to the outrigger devices, respectively, for selectively supplying oil to the overhang cylinder and the jack cylinder;
A cylinder drive control valve for controlling supply and discharge of oil from a hydraulic supply source to the cylinder selection valve;
A first oil passage connecting the cylinder drive control valve and the cylinder selection valve; a second oil passage connecting the cylinder selection valve and a bottom chamber of the jack cylinder; the rod chamber of the jack cylinder; and the cylinder drive control. A fourth oil passage connecting the valve and a fifth oil passage connecting the rod chamber of the overhang cylinder and the third oil passage;
A pilot check valve is provided corresponding to each of the second oil passage and the third oil passage, and the pilot check valve allows oil to flow to the jack cylinder side, and the cylinder selection valve side and the cylinder The flow of oil to the drive control valve side is restricted, and the pilot pressure in the oil passage upstream of the pilot check valve disposed upstream of the oil flowing through the second oil passage and the third oil passage is reduced. A double pilot check valve configured to open the pilot check valve disposed on the downstream side and allow oil to flow to the cylinder selection valve side and the cylinder drive control valve side when received. In the vehicle body lifting support device,
The cylinder drive control valve is configured to shut off oil supply to the cylinder selection valve in a neutral state;
The fifth oil passage has a rod connection oil passage that connects the rod chambers of the plurality of overhang cylinders, and a communication oil passage that communicates with the rod connection oil passage and connects to the third oil passage.
A pilot line is connected to an eighth oil passage that is disposed in the communication oil passage and connects the hydraulic pressure supply source and the cylinder drive control valve to allow the oil to flow to the overhanging cylinder side, and to perform the cylinder drive control. The cylinder drive control valve is configured to restrict the flow of oil to the valve side and to receive the pilot pressure of the oil flowing through the eighth oil passage through the pilot line when the cylinder drive control valve is in a neutral state. A vehicle body lifting support device having a pilot check valve for restricting the flow of oil to the side.