JP4328479B2

JP4328479B2 - Vehicle drive control device

Info

Publication number: JP4328479B2
Application number: JP2001269902A
Authority: JP
Inventors: 高志中山; 孝明大葉; 太小林; 義正中盛; 祐一八木澤
Original assignee: Aichi Corp
Current assignee: Aichi Corp
Priority date: 2001-09-06
Filing date: 2001-09-06
Publication date: 2009-09-09
Anticipated expiration: 2021-09-06
Also published as: JP2003074699A

Description

【０００１】
【発明の属する技術分野】
本発明は、車体の左右にクローラもしくは車輪からなる走行手段が設けられ、これら左および右走行手段をそれぞれ左および右油圧モータにより駆動するように構成された車両の走行駆動制御装置に関する。
【０００２】
このような構成の車両は作業用車両等として従来から多く用いられており、例えば、左右にクローラを有した走行体の上に旋回自在に旋回台を配設し、この旋回台に起伏および伸縮自在にブームを取り付けるとともにこのブームの先端に作業者搭乗用の作業台を取り付けてなる自走式高所作業車がある。この高所作業車においては、左右のクローラにそれぞれ油圧モータを取り付けてこれら左右の油圧モータへの供給油量を電磁バルブにより制御することにより、左右のクローラを同一速度で駆動して車両を直進走行させたり、左右のクローラの駆動速度を相違させて車両を旋回走行させたりするように構成される。
【０００３】
【発明が解決しようとする課題】
ところで、このように左右油圧モータへの作動油供給制御を電磁バルブにより行う場合、電磁バルブの作動特性のバラツキや油温変化の影響により、各油圧モータへの目標供給油量と実際の油量とに差が発生し、走行特性、特に直進走行特性が低下するという問題がある。具体的には、車両を直進走行させる場合には、左右の油圧モータを同一速度で駆動させる必要があり、左右の作動油供給制御用電磁バルブから左右のモータに同一の油量を供給する制御が必要となる。しかしながら、たとえ左右の電磁バルブに同一の作動信号を入力してもこれら左右の電磁バルブから左右油圧モータへの供給油量を正確に一致させることが難しく、左右の電磁バルブに対する作動指令信号をきめ細かく調整する必要がある。特に、この調整は各車両毎に行う必要があり、この調整に多大な工数を要するという問題がある。
【０００４】
本発明はこのような問題に鑑みたもので、左右油圧モータへの作動油供給制御を行う電磁バルブの調整作業が簡単であり、且つ車両の直進性を向上させることができるような構成の車両の走行駆動制御装置を提供することを目的とする。
【０００５】
【課題を解決するための手段】
このような目的達成のため、本発明においては、車体の左右に設けられて車体を走行駆動する左および右走行手段（例えば、実施形態における左右クローラ１２，１３）と、これら左および右走行手段をそれぞれ駆動する左および右油圧モータと、油圧供給源から供給される作動油を左および右油圧モータにそれぞれ独立して供給する制御を行う左および右モータ制御バルブと、右モータ制御バルブから右油圧モータに作動油を供給する右油路と左モータ制御バルブから左モータに作動油を供給する左油路とを繋ぐ連通油路と、この連通油路に配設されてその開閉制御を行う連通制御バルブと、走行操作レバーと、左および右モータ制御バルブ並びに連通制御バルブの作動制御を行なうコントローラとを備えて車両の走行駆動制御装置が構成される。そして、この走行駆動制御装置において、コントローラは、走行操作レバーの操作に応じて左および右モータ制御バルブの作動を制御して左および右油圧モータによる左および右走行手段の走行駆動を行う。さらに、走行操作レバーが車両を直進走行させる操作がなされたときにコントローラは連通制御バルブにより連通油路を開放させ、一方、走行操作レバーが車両を旋回走行させる操作がなされたときにコントローラは連通制御バルブにより連通油路を閉止させる制御を行う。
【０００６】
このような構成の車両の走行駆動制御装置を用いれば、走行操作レバーが車両を直進走行させるように操作されたときには、連通制御バルブが連通油路を開放させて左および右油路がこの連通油路を介して連通する。ここで一般的に、直進走行を行うのは平坦で水平もしくは緩やかな傾斜路面であり、左右の油圧モータの駆動負荷すなわち油圧モータに供給される油圧が等しくなる。このため、左右のモータ制御バルブから左右の油圧モータに供給される油量が相違した場合には左右油路の油圧が相違するが、この油圧差に応じて連通油路を通る油の流れが生じて左右油路の油圧および油量が等しくなった状態で左右油圧モータに供給される。その結果、左右油圧モータの回転速度が等しくなり、左右走行手段の走行駆動速度が等しくなって直進性が向上する。
【０００７】
なお、上記構成の走行駆動制御装置において、連通制御バルブを、連通油路の開度を全開および全閉に選択的に切り換えるオン・オフ開閉制御を行うオン・オフ開閉制御バルブから構成する。そして、走行操作レバーが直進走行操作から旋回走行操作もしくは旋回走行操作から直進走行操作に切り換えられたときに、コントローラは、切換後すぐに左および右モータ制御バルブの走行操作レバーの操作に応じた比例作動制御を開始するが、連通制御バルブのオン・オフ開閉制御による連通油路の全開および全閉切換制御を所定時間遅れの後に開始する。
【０００８】
本発明の走行駆動制御装置においては、直進走行時には連通制御バルブが開放され、旋回走行時にはこれが閉止されるが、上記のようにオン・オフ開閉制御バルブを用いて連通制御バルブを構成すると、直進走行と旋回走行との切換時に連通油路が突然開放もしくは閉止されることになり、ショックが発生するおそれがある。このため、本発明においては、直進走行と旋回走行との切換時に、連通制御バルブは現状のままで保持してまず左右モータ制御バルブの作動制御を行い、所定時間の遅れをおいて連通制御バルブのオン・オフ作動を行わせることによりこのようなショックを抑制している。
【０００９】
また、本発明の走行駆動制御装置において、連通制御バルブを連通油路の開度を全開から全閉までもしくは全閉から全開まで段階的もしくは連続的に制御する比例制御バルブから構成しても良い。この場合には、走行操作レバーが直進走行操作から旋回走行操作もしくは旋回走行操作から直進走行操作に切り換えられたときに、コントローラは、切換後すぐに左および右モータ制御バルブの走行操作レバーの操作に応じた比例作動制御を開始するとともに連通制御バルブにより連通油路の開度を目的開度まで（すなわち、全開から全閉までもしくは全閉から全開まで）緩やかに変化させる制御を行う。このように連通制御バルブの開度を緩やかに変化させることにより、上述したような直進走行と旋回走行との切換時に発生するショックを抑制できる。
【００１０】
【発明の実施の形態】
以下、図面を参照して本発明の好ましい実施形態について説明する。図２に本発明に係る走行駆動制御装置を備える高所作業車（クローラ車）１０を示している。この高所作業車１０は、走行車体１１の左右両側にそれぞれクローラ１２，１３を配置して構成され、これら左右クローラ１２，１３はそれぞれ左右油圧モータ２３，３３により駆動されて走行可能となっている。具体的には、左右油圧モータ２３，３３を正転作動することにより、左右クローラ１２，１３は車体を前進走行させる方向に駆動され、逆転作動することにより車体を後進走行させる方向に駆動される。
【００１１】
この走行体１１の上には、旋回台１５が水平旋回自在に取り付けられている。この旋回台１５には、テレスコープ状に伸縮自在に構成されたブーム１６が起伏自在に取り付けられている。ブーム１６の先端には、作業台１７が図示しないレベリング装置により水平に保持されて取り付けられており、この作業台１７の内側上部には、走行操作レバー１８を備えた走行駆動制御装置２０や、その他の操作装置が取り付けられている。
【００１２】
このように構成された高所作業車１０の作業台１７には作業者が搭乗することができ、その作業者は、各操作装置の操作を通じて左右油圧モータ２３，３３による左右クローラ１２，１３の駆動制御やブーム１６等の作動制御を行う。これにより、高所作業車１０を走行させるとともに、作業台１７を所望高所に移動させてここに搭乗した作業者による高所作業を行うことができる。
【００１３】
このような高所作業車１０の走行制御は、作業者が走行操作レバー１８を操作して行うが、この走行制御を行う走行駆動制御装置２０について、図１を参照して説明する。走行駆動制御装置２０は、左右油圧モータ２３，３３に駆動油圧を供給するための左右油圧ポンプ２１，３１を有し、これら左右油圧ポンプ２１，３１から吐出される作動油が左右モータ制御バルブ２２，３２により制御されて左右油圧モータ２３，３３に供給されるようになっている。左右油圧ポンプ２１，３１は図示しないエンジンにより駆動され、通常は同一吐出容量のポンプから構成される。
【００１４】
左モータ制御バルブ２２は左右のソレノイド２２ａ，２２ｂにより作動制御される電磁比例制御バルブから構成されており、左油圧モータ２３と第１左油路２４および第２左油路２５を介して繋がっている。ここで左ソレノイド２２ａを励磁すると左モータ制御バルブ２２を図において右動させ、左油圧ポンプ２１からの吐出油を第１左油路２４を介して左油圧モータ２３に供給してこれを前進側に回転（正転）駆動させ、左油圧モータ２３から排出されて第２左油路２５を通って戻る作動油をタンクＴに排出させる。一方、右ソレノイド２２ｂを励磁すると左モータ制御バルブ２２を図において左動させ、左油圧ポンプ２１からの吐出油を第２左油路２５を介して左油圧モータ２３に供給してこれを後進側に回転（逆転）駆動させ、左油圧モータ２３から排出されて第１左油路２４を通って戻る作動油をタンクＴに排出させる。なお、左モータ制御バルブ２２は電磁比例制御バルブであり、上記のように左油圧モータ２３に対する作動油の供給方向を制御してその回転方向を切り換える制御だけでなく、左右ソレノイド２２ａ，２２ｂの励磁電流値を制御することにより、左油圧モータ２３へ供給する油量制御を行って、走行速度の制御も行う。
【００１５】
同様に、右モータ制御バルブ３２は左右のソレノイド３２ａ，３２ｂにより作動制御される電磁比例制御バルブから構成されており、右油圧モータ３３と第１右油路３４および第２右油路３５を介して繋がっている。左ソレノイド３２ａを励磁すると、右油圧ポンプ３１からの吐出油を、第１右油路３４を介して右油圧モータ３３に供給してこれを前進側に回転駆動させた後、第２右油路３５を通ってタンクＴに排出させる。一方、右ソレノイド３２ｂを励磁すると、右油圧ポンプ３１からの吐出油を第２右油路３５を介して右油圧モータ３３に供給して後進側に回転駆動させた後、第１右油路３４を通ってタンクＴに排出させる。なお、右モータ制御バルブ３２は電磁比例制御バルブであり、上記のように右油圧モータ３３の回転方向を切り換える制御だけでなく、左右ソレノイド３２ａ，３２ｂの励磁電流値を制御することにより、右油圧モータ３３へ供給する油量制御を行って、走行速度の制御も行う。
【００１６】
さらに、第１左油路２４と第１右油路３４とを繋ぐ第１連通油路４１と、第２左油路２５と第２右油路３５とを繋ぐ第２連通油路５１とが設けられている。これら第１連通油路４１および第２連通油路５１にはそれぞれオン・オフ開閉電磁バルブからなる第１連通制御バルブ４５および第２連通制御バルブ５５が配設されいる。第１および第２連通制御バルブ４５，５５はともにノーマルクローズタイプのバルブであり、ソレノイド４６，５６が非励磁状態で第１および第２連通油路４５，５５を全閉とし、励磁状態で全開とする。
【００１７】
上記左右モータ制御バルブ２２，３２の作動制御（具体的には、左右ソレノイド２２ａ，２２ｂおよび３２ａ，３２ｂの励磁制御）および第１および第２連通制御バルブ４５，５５の作動制御（具体的には、ソレノイド４６，５６の励磁制御）を行うため、コントローラ３０が設けられている。コントローラ３０には走行操作レバー１８から操作信号が入力され、この操作信号に応じてコントローラ３０が各制御バルブの作動制御を行う。操作レバー１８は一本の操作レバーにより構成され、これを前後に傾動させる操作を行わせることにより前後進の切換を行うとともに、傾動角に応じて前後進速度制御を行う。また、この操作レバー１８を左右に傾動させる操作を行うことにより左右旋回制御を行う。例えば、走行操作レバー１８を右斜め前方向に傾動させると車両を前進させながら右旋回させる制御を行う。このため、操作レバー１８が前後に傾動操作されたか（すなわち、前後進方向に直進走行させるように操作されたか）、左右方向に傾動操作されたか（旋回走行させるように操作されたか）を検出するセレクタスイッチと、このときの傾動角を検出するポテンショメータとが設けられている。
【００１８】
このため、例えば、走行操作レバー１８が前方もしくは後方に傾動操作されると、コントローラ３０は左右モータ制御バルブ２２，３２から等しい流量の作動油をそれぞれ左右の油圧モータ２３，３３に供給させる制御を行う。これにより、左右油圧モータ２３，３３を同一速度で同一方向（前方もしくは後方）に駆動し、左右クローラ１２，１３を同一速度で同一方向に駆動して車両を前方もしくは後方に直進走行させる。
【００１９】
但し、この場合、左右モータ制御バルブ２２，３２が同一の構成のバルブからなり同一の作動信号（励磁電流）を送っても、それぞれの寸法精度のバラツキ、流量特性のバラツキ等による個体差があるため、左右油圧モータ２３，３３に供給される油量が若干相違し、直進走行性能が低下するという問題がある。従来ではこのような供給油量の差をできる限り小さく抑えて直進走行性を高めるように、各車両毎に制御電流調整等を行っていた。しかしながら、このような調整は非常に大きな工数を要するため、ここでは直進走行時に第１および第２連通制御バルブ４５，５５を開放して第１および第２連通油路４１，５１により第１左および第１右油路２４，３４同士を連通させ、第２左および第２右油路２５，３５同士を連通させている。
【００２０】
ところで一般的に言って、直進走行を行うのは平坦な水平路面や平坦で緩やかな傾斜路面であり、左右のクローラ１２，１３の走行負荷が等しく左右の油圧モータ２３，３３の駆動負荷が等しいと考えられる。このようなときに左右モータ制御バルブ２２，３２から左右の油路（前進走行のときには第１左油路２４および第１右油路３４）に供給される油量に差があるとこの差に応じて発生内圧が相違するが、上記のように第１および第２連通制御バルブ４５，５５が全開であるので、この内圧差により第１もしくは第２連通油路４１，５１を介して油が流れ、上記油量差がなくなる。この結果、左右油圧モータ２３，３３には等しい油量が供給されて同一速度で回転駆動され、左右のクローラ１２，１３の走行速度が等しくなり、車両の直進走行性が向上する。
【００２１】
一方、走行操作レバー１８が車両を右もしくは左旋回走行させるように操作される（走行操作レバー１８が右もしくは左斜め前方や後方に傾動操作される）と、コントローラ３０は左右モータ制御バルブ２２，３２からそのときの傾動方向および角度に応じて所定の流量の作動油をそれぞれ左右の油圧モータ２３，３３に供給させる制御を行う。この所定流量は左右で相違し、この相違する流量に対応して左右油圧モータ２３，３３が異なる速度で駆動され、左右クローラ１２，１３も異なる速度で駆動されて車両を旋回走行させる。このとき、第１および第２連通制御バルブ４５，５５が開放していたのでは、上記のように左右油圧モータ２３，３３を異なる速度で駆動できないため、旋回走行時には第１および第２連通制御バルブ４５，５５は全閉状態にされる。
【００２２】
以上、直進走行および旋回走行制御について説明したが、上記説明から分かるように、第１および第２連通制御バルブ４５，５５は、直進走行時に全開となり旋回走行時に全閉となる。ここで、第１および第２連通制御バルブ４５，５５はオン・オフ開閉制御バルブであるため、直進走行から旋回走行に切り替わるときもしくは旋回走行から直進走行に切り替わるときに第１および第２連通油路４１，５１の連通開度が全閉から全開もしくは全開から全閉に急激に変化する。このため、この変化に応じて、左右油圧モータ２３，３３に供給される油量が急激に変動して走行ショックが発生するという問題がある。
【００２３】
このようなことから、本実施形態では、直進走行から旋回走行に切り替わるときもしくは旋回走行から直進走行に切り替わるときに、コントローラ３０により、左右モータ制御バルブ２２，３２の作動制御に対して、第１および第２連通制御バルブ４５，５５の作動制御を所定時間遅らせて開始するようにしている。これについて図３を参照して説明する。図３は横軸に時間を示し、左から右に向けて時間が経過するときの操作レバー操作信号と第１および第２連通制御バルブ４５，５５の制御信号とを示している。
【００２４】
図３には、最初は直進走行している状態から時間ｔ１において操作レバー１８が旋回走行（ターン）するように操作されて旋回走行が開始され、時間ｔ３において操作レバー１８が直進走行に戻された場合を示している。この場合に、時間ｔ１において、コントローラ３０は左右モータ制御バルブ２２，３２の作動制御を旋回走行制御に変更し、左右油圧モータ２３，３３に旋回走行のために必要な左右で相違する流量を供給させるような制御を開始する。但し、この時間ｔ１においては、第１および第２連通制御バルブ４５，５５は全開のまま（直進走行時のまま）で保持し、所定の時間遅れΔｔ１の経過を待って時間ｔ２においてこれらを全閉にさせる。同様に、時間ｔ３においてコントローラは左右モータ制御バルブ２２，３２の作動制御を直進走行制御に変更し、左右油圧モータ２３，３３に等しい流量を供給させるような制御を開始する。但し、時間ｔ３においては、第１および第２連通制御バルブ４５，５５は全閉のままで保持し、所定の時間遅れΔｔ２の経過を待って時間ｔ４においてこれらを全開にさせる。
【００２５】
このように時間遅れを置くことにより、直進走行と旋回走行との切換時にはまず左右モータ制御バルブ２２，３２の作動制御を行って切換後の走行に対応する油量を油圧モータ側に供給させ、これが所定時間遅れを置いて落ち着いたときに第１および第２連通制御バルブ４５，５５を全開から全閉もしくは全閉から全開に切り換え、切換時の走行ショックの発生を抑えることができる。なお、この走行ショックは、高所作業車１０の走行速度や、ブーム１６の伸張量に応じて相違するため、これらに応じて時間遅れΔｔ１，Δｔ２の大きさが適宜設定される。具体的には、走行速度が大きい程、またブーム伸張量が大きい程、大きな時間遅れが設定される。
【００２６】
以上においては、第１および第２連通制御バルブ４５，５５をオン・オフ開閉制御バルブから構成した例を示したが、これらを電磁比例制御バルブから構成し、第１および第２連通油路４１，５１の連通開度を段階的もしくは連続的に変化させる制御が行えるようにしても良い。この場合には、直進走行と旋回走行との切換時に、図４に示すように、切換開始から第１および第２連通油路４１，５１の連通開度を全開から全閉までもしくは全閉から全開まで緩やかに変化させる制御が行われ、切換時の走行ショックを低減させている。なお、この場合に連通開度を変化させるに要する時間Δｔ１およびΔｔ２は、走行速度が大きい程、またブーム伸張量が大きい程、大きな値に設定される。
【００２７】
【発明の効果】
以上説明したように、本発明に係る車両の走行駆動制御装置を用いれば、走行操作レバーが車両を直進走行させるように操作されたときには、連通制御バルブが連通油路を開放させて左および右油路がこの連通油路を介して連通するため、左右のモータ制御バルブから左右の油圧モータに供給される油量が相違した場合には左右油路に発生する油圧差に応じて連通油路を通る油の流れが生じて左右油路の油圧および油量が等しくなった状態で左右油圧モータに作動油が供給される。その結果、左右油圧モータの回転速度が等しくなり、左右走行手段の走行駆動速度が等しくなって直進性を向上させることができる。
【００２８】
なお、上記構成の走行駆動制御装置において、連通制御バルブをオン・オフ開閉制御バルブから構成する場合は、走行操作レバーが直進走行操作から旋回走行操作もしくは旋回走行操作から直進走行操作に切り換えられたときに、コントローラは、切換後すぐに左および右モータ制御バルブの作動制御を開始するが、連通制御バルブのオン・オフ開閉制御を所定時間遅れの後に開始するので、これにより直進走行と旋回走行との切換時に走行ショックが発生することを抑制することができ、スムーズな切換制御を行うことができる。
【００２９】
また、連通制御バルブを連通油路の開度を段階的もしくは連続的に制御する比例制御バルブから構成しても良く、この場合には、走行操作レバーが直進走行操作から旋回走行操作もしくは旋回走行操作から直進走行操作に切り換えられたときに、コントローラは、切換後すぐに左および右モータ制御バルブの作動制御を開始するとともに連通制御バルブにより連通油路の開度を目的開度まで（すなわち、全開から全閉までもしくは全閉から全開まで）緩やかに変化させる制御を行う。このように連通制御バルブの開度を緩やかに変化させることにより、上述したような直進走行と旋回走行との切換時に発生するショックを抑制して、スムーズな切換制御を行うことができる。
【図面の簡単な説明】
【図１】本発明に係る車両の走行駆動制御装置の構成を示す油圧回路図である。
【図２】上記走行駆動制御装置を有した自走式高所作業車を示す斜視図である。
【図３】上記走行駆動制御装置により直進走行と旋回走行との切り換えを行うときでの操作レバー操作信号に対する連通制御バルブの制御信号の出力状態を示すグラフである。
【図４】本発明の異なる実施形態に係る走行駆動制御装置により直進走行と旋回走行との切り換えを行うときでの操作レバー操作信号に対する連通制御バルブの制御信号の出力状態を示すグラフである。
【符号の説明】
１０高所作業車
１１，１２左および右クローラ（左および右走行手段）
１８走行操作レバー
２２，３２左および右モータ制御バルブ
２３，３３左および右油圧モータ
２４，３４第１および第２右油路
２５，３５第１および第２左油路
３０コントローラ
４１，５１第１および第２連通油路
４５，５５第１および第２連通制御バルブ[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vehicle travel drive control device in which travel means comprising crawlers or wheels are provided on the left and right sides of a vehicle body, and these left and right travel means are driven by left and right hydraulic motors, respectively.
[0002]
A vehicle having such a configuration has been conventionally used as a working vehicle or the like. For example, a swivel is provided on a traveling body having crawlers on the left and right, and the swivel is undulated and extended. There is a self-propelled aerial work vehicle in which a boom is freely attached and a work board for operator boarding is attached to the tip of the boom. In this aerial work vehicle, hydraulic motors are attached to the left and right crawlers, respectively, and the amount of oil supplied to the left and right hydraulic motors is controlled by electromagnetic valves. The vehicle is configured to travel or to turn the vehicle while making the drive speeds of the left and right crawlers different.
[0003]
[Problems to be solved by the invention]
By the way, when the hydraulic oil supply control to the left and right hydraulic motors is performed by the electromagnetic valves as described above, the target supply oil amount and the actual oil amount to each hydraulic motor are affected by the variation in the operation characteristics of the electromagnetic valves and the influence of the oil temperature change. There is a problem that the running characteristics, particularly the straight running characteristics are deteriorated. Specifically, when the vehicle is traveling straight, it is necessary to drive the left and right hydraulic motors at the same speed, and control to supply the same amount of oil from the left and right hydraulic oil supply control electromagnetic valves to the left and right motors. Is required. However, even if the same actuation signal is input to the left and right solenoid valves, it is difficult to accurately match the amount of oil supplied from the left and right solenoid valves to the left and right hydraulic motors. It needs to be adjusted. In particular, this adjustment needs to be performed for each vehicle, and there is a problem that this adjustment requires a great number of man-hours.
[0004]
The present invention has been made in view of such a problem, and a vehicle having a configuration in which adjustment work of an electromagnetic valve for performing hydraulic oil supply control to the left and right hydraulic motors is simple and the straightness of the vehicle can be improved. An object of the present invention is to provide a travel drive control device.
[0005]
[Means for Solving the Problems]
In order to achieve such an object, in the present invention, left and right traveling means (for example, left and right crawlers 12 and 13 in the embodiment) provided on the left and right of the vehicle body to drive the vehicle body, and these left and right traveling means. Left and right hydraulic motors for driving the left and right hydraulic motors, left and right motor control valves for controlling the supply of hydraulic oil supplied from a hydraulic supply source to the left and right hydraulic motors, respectively, and the right from the right motor control valve A communication oil passage that connects a right oil passage that supplies hydraulic oil to the hydraulic motor and a left oil passage that supplies hydraulic oil from the left motor control valve to the left motor, and is disposed in the communication oil passage to perform opening / closing control thereof. A vehicle travel drive control device includes a communication control valve, a travel operation lever, a left and right motor control valve, and a controller that controls the operation of the communication control valve. It is. In this travel drive control device, the controller controls the operation of the left and right motor control valves according to the operation of the travel operation lever to drive the left and right travel means by the left and right hydraulic motors. Further, the controller opens the communication oil path by the communication control valve when the travel operation lever is operated to travel straight ahead, while the controller communicates when the travel control lever is operated to turn the vehicle. A control valve is used to close the communication oil passage.
[0006]
When the vehicle drive control device for a vehicle having such a configuration is used, when the travel control lever is operated so that the vehicle travels straight, the communication control valve opens the communication oil passage, and the left and right oil passages communicate with this communication. It communicates through an oil passage. Here, in general, straight traveling is performed on a flat, horizontal or gently inclined road surface, and the drive loads of the left and right hydraulic motors, that is, the hydraulic pressure supplied to the hydraulic motors are equal. For this reason, when the amount of oil supplied from the left and right motor control valves to the left and right hydraulic motors is different, the oil pressure in the left and right oil passages is different, but the flow of oil through the communication oil passages depends on this hydraulic pressure difference. It is generated and supplied to the left and right hydraulic motors in a state where the oil pressure and oil amount of the left and right oil passages are equal. As a result, the rotational speeds of the left and right hydraulic motors are equalized, the traveling drive speeds of the left and right traveling means are equalized, and straight travel performance is improved.
[0007]
In the travel drive control device configured as described above, the communication control valve is configured by an on / off opening / closing control valve that performs on / off opening / closing control that selectively switches the opening of the communication oil passage between full open and full close. When the traveling operation lever is switched from the straight traveling operation to the turning traveling operation or from the turning traveling operation to the straight traveling operation, the controller responds to the operation of the traveling operation lever of the left and right motor control valves immediately after the switching . Proportional operation control is started, but full open and full close switching control of the communication oil passage by on / off opening / closing control of the communication control valve is started after a predetermined time delay.
[0008]
In the traveling drive control device of the present invention, the communication control valve is opened during straight traveling and is closed during turning, but when the communication control valve is configured using the on / off opening / closing control valve as described above, the communication control valve is configured to travel straight. At the time of switching between running and turning, the communication oil path is suddenly opened or closed, which may cause a shock. Therefore, in the present invention, at the time of switching between straight traveling and turning traveling, the communication control valve is maintained as it is, and the operation control of the left and right motor control valves is performed first, and the communication control valve is delayed after a predetermined time. Such a shock is suppressed by performing an on / off operation.
[0009]
In the travel drive control device of the present invention, the communication control valve may be composed of a proportional control valve that controls the opening of the communication oil passage stepwise or continuously from fully open to fully closed or from fully closed to fully open. . In this case, when the traveling operation lever is switched from the straight traveling operation to the turning traveling operation or from the turning traveling operation to the straight traveling operation, the controller operates the traveling operation levers of the left and right motor control valves immediately after the switching. The proportional operation control is started according to the control, and the opening of the communication oil passage is gradually changed from the fully open to fully closed or from fully closed to fully open by the communication control valve. Thus, by gradually changing the opening degree of the communication control valve, it is possible to suppress the shock that occurs when switching between the straight traveling and the turning traveling as described above.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. FIG. 2 shows an aerial work vehicle (crawler vehicle) 10 including a traveling drive control device according to the present invention. The aerial work vehicle 10 is configured by arranging crawlers 12 and 13 on both the left and right sides of a traveling vehicle body 11, respectively. These left and right crawlers 12 and 13 are driven by left and right hydraulic motors 23 and 33, respectively, and can travel. Yes. Specifically, the left and right crawlers 12 and 13 are driven in the direction of traveling forward by rotating the left and right hydraulic motors 23 and 33 in the forward direction, and are driven in the direction of traveling backward by moving in the reverse direction. .
[0011]
On the traveling body 11, a swivel base 15 is mounted so as to be horizontally swivelable. On the swivel base 15, a boom 16 configured to be telescopic and telescopic is attached. A work platform 17 is attached to the tip of the boom 16 by being held horizontally by a leveling device (not shown), and a travel drive control device 20 having a travel operation lever 18 is installed on the inner upper portion of the work platform 17. Other operating devices are attached.
[0012]
An operator can board the work platform 17 of the aerial work vehicle 10 configured as described above. The worker can operate the left and right crawlers 12 and 13 by the left and right hydraulic motors 23 and 33 through the operation of each operation device. Drive control and operation control of the boom 16 and the like are performed. As a result, the aerial work vehicle 10 can be caused to travel, and the work platform 17 can be moved to a desired high place to perform a high place work by an operator boarding the work place.
[0013]
Such traveling control of the aerial work vehicle 10 is performed by an operator operating the traveling operation lever 18, and a traveling drive control device 20 that performs the traveling control will be described with reference to FIG. The travel drive control device 20 has left and right hydraulic pumps 21 and 31 for supplying drive hydraulic pressure to the left and right hydraulic motors 23 and 33, and hydraulic oil discharged from these left and right hydraulic pumps 21 and 31 is the left and right motor control valve 22. , 32 to be supplied to the left and right hydraulic motors 23, 33. The left and right hydraulic pumps 21 and 31 are driven by an engine (not shown), and are usually composed of pumps having the same discharge capacity.
[0014]
The left motor control valve 22 is composed of an electromagnetic proportional control valve that is operated and controlled by left and right solenoids 22a and 22b, and is connected to the left hydraulic motor 23 via a first left oil passage 24 and a second left oil passage 25. Yes. Here, when the left solenoid 22a is excited, the left motor control valve 22 is moved to the right in the drawing, and the discharge oil from the left hydraulic pump 21 is supplied to the left hydraulic motor 23 via the first left oil passage 24, and this is advanced. And the hydraulic oil discharged from the left hydraulic motor 23 and returning through the second left oil passage 25 is discharged to the tank T. On the other hand, when the right solenoid 22b is energized, the left motor control valve 22 is moved to the left in the drawing, and the discharge oil from the left hydraulic pump 21 is supplied to the left hydraulic motor 23 via the second left oil passage 25, and this is moved backward. The hydraulic oil discharged from the left hydraulic motor 23 and returning through the first left oil passage 24 is discharged to the tank T. The left motor control valve 22 is an electromagnetic proportional control valve. As described above, not only the control of switching the rotation direction by controlling the supply direction of hydraulic oil to the left hydraulic motor 23, but also the excitation of the left and right solenoids 22a and 22b. By controlling the current value, the amount of oil supplied to the left hydraulic motor 23 is controlled, and the traveling speed is also controlled.
[0015]
Similarly, the right motor control valve 32 is composed of an electromagnetic proportional control valve that is operated and controlled by left and right solenoids 32 a and 32 b, via a right hydraulic motor 33, a first right oil passage 34 and a second right oil passage 35. Connected. When the left solenoid 32a is energized, the discharge oil from the right hydraulic pump 31 is supplied to the right hydraulic motor 33 via the first right oil passage 34 and rotated forward to the second right oil passage. 35 is discharged into the tank T. On the other hand, when the right solenoid 32b is excited, the oil discharged from the right hydraulic pump 31 is supplied to the right hydraulic motor 33 via the second right oil passage 35 and rotated backward, and then the first right oil passage 34 is supplied. Through the tank T. The right motor control valve 32 is an electromagnetic proportional control valve. In addition to the control for switching the rotation direction of the right hydraulic motor 33 as described above, the right motor control valve 32 is controlled by controlling the excitation current values of the left and right solenoids 32a and 32b. The amount of oil supplied to the motor 33 is controlled, and the traveling speed is also controlled.
[0016]
Furthermore, a first communication oil passage 41 that connects the first left oil passage 24 and the first right oil passage 34 and a second communication oil passage 51 that connects the second left oil passage 25 and the second right oil passage 35 are provided. Is provided. The first communication oil passage 41 and the second communication oil passage 51 are respectively provided with a first communication control valve 45 and a second communication control valve 55 which are on / off open / close electromagnetic valves. The first and second communication control valves 45 and 55 are both normally closed valves, and the first and second communication oil passages 45 and 55 are fully closed when the solenoids 46 and 56 are in a non-excited state, and are fully opened in an excited state. And
[0017]
Operation control of the left and right motor control valves 22, 32 (specifically, excitation control of the left and right solenoids 22a, 22b and 32a, 32b) and operation control of the first and second communication control valves 45, 55 (specifically, In order to perform excitation control of the solenoids 46 and 56, a controller 30 is provided. An operation signal is input to the controller 30 from the travel operation lever 18, and the controller 30 controls the operation of each control valve according to the operation signal. The operation lever 18 is constituted by a single operation lever, and performs forward and backward switching by performing an operation of tilting the operation lever forward and backward, and performs forward and backward speed control according to the tilt angle. Further, left / right turning control is performed by performing an operation of tilting the operation lever 18 to the left / right. For example, when the traveling operation lever 18 is tilted diagonally forward to the right, the vehicle is controlled to turn right while moving forward. Therefore, it is detected whether the operation lever 18 is tilted back and forth (that is, operated to travel straight forward in the forward / backward direction) or tilted in the left / right direction (operated to swing). A selector switch and a potentiometer for detecting the tilt angle at this time are provided.
[0018]
For this reason, for example, when the traveling operation lever 18 is tilted forward or backward, the controller 30 performs control to supply the left and right hydraulic motors 23 and 33 with the same amount of hydraulic fluid from the left and right motor control valves 22 and 32, respectively. Do. Accordingly, the left and right hydraulic motors 23 and 33 are driven in the same direction (forward or backward) at the same speed, and the left and right crawlers 12 and 13 are driven in the same direction at the same speed to drive the vehicle straight forward or backward.
[0019]
However, in this case, even if the left and right motor control valves 22 and 32 have the same configuration and send the same actuation signal (excitation current), there are individual differences due to variations in dimensional accuracy, variations in flow characteristics, and the like. Therefore, there is a problem that the amount of oil supplied to the left and right hydraulic motors 23 and 33 is slightly different, and the straight traveling performance is deteriorated. Conventionally, control current adjustment and the like have been performed for each vehicle so as to suppress such a difference in the amount of supplied oil as much as possible and improve straight traveling performance. However, since such adjustment requires a very large number of man-hours, the first left and second communication control valves 45 and 55 are opened and the first left and second communication oil passages 41 and 51 open the first left during straight traveling. The first right oil passages 24 and 34 are communicated with each other, and the second left and second right oil passages 25 and 35 are communicated with each other.
[0020]
By the way, generally speaking, the straight traveling is performed on a flat horizontal road surface or a flat and gently sloping road surface, the traveling loads of the left and right crawlers 12 and 13 are equal, and the driving loads of the left and right hydraulic motors 23 and 33 are equal. it is conceivable that. In such a case, if there is a difference in the amount of oil supplied from the left and right motor control valves 22 and 32 to the left and right oil passages (the first left oil passage 24 and the first right oil passage 34 when traveling forward), this difference is indicated. Depending on the internal pressure, the first and second communication control valves 45 and 55 are fully open as described above, so that the oil flows through the first or second communication oil passages 41 and 51 due to this internal pressure difference. The above oil amount difference disappears. As a result, the left and right hydraulic motors 23 and 33 are supplied with the same amount of oil and are driven to rotate at the same speed, the traveling speeds of the left and right crawlers 12 and 13 become equal, and the straight traveling performance of the vehicle is improved.
[0021]
On the other hand, when the travel operation lever 18 is operated to turn the vehicle to the right or left (the travel operation lever 18 is tilted to the right or left diagonally forward or backward), the controller 30 controls the left and right motor control valves 22, From 32, control is performed to supply hydraulic oil of a predetermined flow rate to the left and right hydraulic motors 23 and 33 in accordance with the tilting direction and angle at that time. The predetermined flow rate is different between right and left, and the left and right hydraulic motors 23 and 33 are driven at different speeds corresponding to the different flow rates, and the left and right crawlers 12 and 13 are also driven at different speeds to turn the vehicle. At this time, if the first and second communication control valves 45 and 55 are opened, the left and right hydraulic motors 23 and 33 cannot be driven at different speeds as described above. The valves 45 and 55 are fully closed.
[0022]
The straight traveling and the turning traveling control have been described above. As can be understood from the above description, the first and second communication control valves 45 and 55 are fully opened during the straight traveling and are fully closed during the turning traveling. Here, since the first and second communication control valves 45 and 55 are on / off opening / closing control valves, the first and second communication oils are used when switching from straight traveling to turning traveling or when switching from turning traveling to straight traveling. The communication opening degree of the paths 41 and 51 changes suddenly from fully closed to fully open or from fully open to fully closed. For this reason, according to this change, there is a problem that the amount of oil supplied to the left and right hydraulic motors 23 and 33 fluctuates rapidly and a running shock occurs.
[0023]
For this reason, in the present embodiment, when switching from the straight traveling to the turning traveling or when switching from the turning traveling to the straight traveling, the controller 30 controls the first control operation of the left and right motor control valves 22 and 32. The operation control of the second communication control valves 45 and 55 is started after being delayed by a predetermined time. This will be described with reference to FIG. FIG. 3 shows time on the horizontal axis, and shows an operation lever operation signal and control signals for the first and second communication control valves 45 and 55 when the time elapses from left to right.
[0024]
In FIG. 3, the operation lever 18 is operated so as to turn (turn) at time t1 from the state where the vehicle is running straight ahead, and turning operation is started. At time t3, the operation lever 18 is returned to straight running. Shows the case. In this case, at time t1, the controller 30 changes the operation control of the left and right motor control valves 22 and 32 to turning traveling control, and supplies the left and right hydraulic motors 23 and 33 with different flow rates required for turning traveling. Start the control. However, at this time t1, the first and second communication control valves 45, 55 are held fully open (while driving straight), and after waiting for the elapse of a predetermined time delay Δt1, all of them are held at time t2. Close. Similarly, at time t3, the controller changes the operation control of the left and right motor control valves 22 and 32 to straight traveling control, and starts control to supply equal flow rates to the left and right hydraulic motors 23 and 33. However, at time t3, the first and second communication control valves 45 and 55 are held fully closed, and after a predetermined time delay Δt2 has elapsed, they are fully opened at time t4.
[0025]
By setting a time delay in this way, at the time of switching between the straight traveling and the turning traveling, first, the operation control of the left and right motor control valves 22 and 32 is performed, and the oil amount corresponding to the traveling after the switching is supplied to the hydraulic motor side, When this settles after a predetermined time delay, the first and second communication control valves 45 and 55 are switched from fully open to fully closed, or from fully closed to fully open, so that the occurrence of running shock at the time of switching can be suppressed. The traveling shock differs depending on the traveling speed of the aerial work vehicle 10 and the extension amount of the boom 16, and accordingly, the magnitudes of the time delays Δt1 and Δt2 are set as appropriate. Specifically, a larger time delay is set as the traveling speed increases and the boom extension amount increases.
[0026]
In the above, an example in which the first and second communication control valves 45 and 55 are configured by on / off opening / closing control valves has been described. However, these are configured by electromagnetic proportional control valves, and the first and second communication oil paths 41 are configured. , 51 may be controlled so as to change the communication opening degree stepwise or continuously. In this case, at the time of switching between straight traveling and turning traveling, as shown in FIG. 4, the communication opening degree of the first and second communication oil passages 41 and 51 is changed from fully open to fully closed or from fully closed as shown in FIG. Control is performed to gradually change to full open, reducing the running shock at the time of switching. In this case, the times Δt1 and Δt2 required to change the communication opening are set to larger values as the traveling speed increases and the boom extension amount increases.
[0027]
【The invention's effect】
As described above, when the vehicle driving control apparatus according to the present invention is used, the communication control valve opens the communication oil passage to open the left and right when the travel operation lever is operated to cause the vehicle to travel straight ahead. Since the oil passage communicates via this communication oil passage, if the amount of oil supplied from the left and right motor control valves to the left and right hydraulic motors is different, the communication oil passage according to the hydraulic pressure difference generated in the left and right oil passages The hydraulic oil is supplied to the left and right hydraulic motors in a state where the oil flows through the oil flow and the oil pressure and the oil amount in the left and right oil passages become equal. As a result, the rotational speeds of the left and right hydraulic motors are equalized, the traveling drive speeds of the left and right traveling means are equalized, and the straight traveling performance can be improved.
[0028]
In the travel drive control device configured as described above, when the communication control valve is configured as an on / off opening / closing control valve, the travel operation lever is switched from the straight travel operation to the turn travel operation or from the turn travel operation to the straight travel operation. when the controller is to start after switching immediately the operation control of the left and right motor control valve, since starting the on-off switching control of the communication control valve after a predetermined time delay, thereby turning the straight running It is possible to suppress the occurrence of running shock when switching between and smooth switching control.
[0029]
Further, the communication control valve may be composed of a proportional control valve that controls the opening of the communication oil passage in a stepwise or continuous manner. In this case, the travel operation lever changes from a straight travel operation to a turn travel operation or a turn travel. When the operation is switched to the straight traveling operation, the controller starts the operation control of the left and right motor control valves immediately after the switching, and the opening degree of the communication oil passage to the target opening degree by the communication control valve (that is, from the fully open to the fully open from fully closed in or fully closed) performs gradual control to change. Thus, by gradually changing the opening degree of the communication control valve, it is possible to suppress a shock that occurs when switching between the straight traveling and the turning traveling as described above, and to perform smooth switching control.
[Brief description of the drawings]
FIG. 1 is a hydraulic circuit diagram showing a configuration of a vehicle drive control apparatus according to the present invention.
FIG. 2 is a perspective view showing a self-propelled aerial work vehicle having the traveling drive control device.
FIG. 3 is a graph showing an output state of a control signal of a communication control valve with respect to an operation lever operation signal when switching between straight travel and turning travel is performed by the travel drive control device.
FIG. 4 is a graph showing an output state of a control signal of a communication control valve with respect to an operation lever operation signal when switching between straight travel and turning travel by a travel drive control device according to a different embodiment of the present invention.
[Explanation of symbols]
10 Aerial platforms 11, 12 Left and right crawlers (left and right traveling means)
18 Travel control levers 22, 32 Left and right motor control valves 23, 33 Left and right hydraulic motors 24, 34 First and second right oil passages 25, 35 First and second left oil passages 30 Controllers 41, 51 First And second communication oil passages 45, 55 first and second communication control valves

Claims

Left and right traveling means provided on the left and right of the vehicle body for driving the vehicle body, left and right hydraulic motors for driving the left and right traveling means, respectively, and hydraulic oil supplied from a hydraulic supply source for the left and right Left and right motor control valves that perform control to be independently supplied to the hydraulic motor, a right oil passage that supplies hydraulic oil from the right motor control valve to the right hydraulic motor, and the left motor control valve to the left motor A communication oil passage that connects a left oil passage that supplies hydraulic oil, a communication control valve that is disposed in the communication oil passage and controls opening and closing thereof, a traveling operation lever, and the operation according to the operation of the traveling operation lever. A left and right motor control valve and a controller for controlling the operation of the communication control valve,
The left and right motor control valves are composed of proportional control valves, and the controller is configured to proportionally control the operation of the left and right motor control valves according to the operation of the travel operation lever.
The communication control valve is configured by an on / off opening / closing control valve, and the controller is configured to perform on / off opening / closing control of the communication control valve to selectively switch the communication oil path between full open and fully closed. And
It said controller the operation of the left and right motor control valve in response to the operation of the travel operation lever proportional control to carry out the traveling drive of the left and right traveling means by the left and right hydraulic motors, the travel operation The controller fully opens the communication oil passage by the communication control valve when the lever is operated to travel straight ahead, and the controller operates when the travel operation lever is operated to turn the vehicle. the communicating oil passage performs control to fully closed by the communication control valve,
When the front SL travel operation lever is switched to the straight travel operation from the turning operation or the turning operation from the straight traveling operation, the controller, the operation of the travel operation lever of the after switching immediately left and right motor control valve The proportional operation control is started according to the control valve, and the full open and full close switching control of the communication oil path by the on / off opening / closing control of the communication control valve is started after a predetermined time delay. A vehicle travel drive control device.

Left and right traveling means provided on the left and right of the vehicle body for driving the vehicle body, left and right hydraulic motors for driving the left and right traveling means, respectively, and hydraulic oil supplied from a hydraulic supply source for the left and right Left and right motor control valves that perform control to be independently supplied to the hydraulic motor, a right oil passage that supplies hydraulic oil from the right motor control valve to the right hydraulic motor, and the left motor control valve to the left motor A communication oil passage that connects a left oil passage that supplies hydraulic oil, a communication control valve that is disposed in the communication oil passage and controls opening and closing thereof, a traveling operation lever, and the operation according to the operation of the traveling operation lever. A left and right motor control valve and a controller for controlling the operation of the communication control valve,
The left and right motor control valves are composed of proportional control valves, and the controller is configured to proportionally control the operation of the left and right motor control valves according to the operation of the travel operation lever.
The communication control valve is composed of a proportional control valve that controls the degree of opening of the communication oil passage in a stepwise or proportional manner from fully open to fully closed or from fully closed to fully open.
It said controller the operation of the left and right motor control valve in response to the operation of the travel operation lever proportional control to carry out the traveling drive of the left and right traveling means by the left and right hydraulic motors, the travel operation The controller fully opens the communication oil passage by the communication control valve when the lever is operated to travel straight ahead, and the controller operates when the travel operation lever is operated to turn the vehicle. the communicating oil passage performs control to fully closed by the communication control valve,
When the front SL travel operation lever is switched to the straight travel operation from the turning operation or the turning operation from the straight traveling operation, the controller, the operation of the travel operation lever of the after switching immediately left and right motor control valve The proportional operation control according to the control is started and the communication control valve is controlled to gradually change the opening of the communication oil passage from fully open to fully closed or from fully closed to fully open. A vehicle travel drive control device.

2. The vehicle travel drive control device according to claim 1 , wherein in the on / off opening / closing control of the communication control valve, the predetermined time delay is set to be larger as the vehicle travel speed is higher.

3. The vehicle travel drive control device according to claim 2 , wherein the proportional control of the communication control valve gradually changes the opening of the communication oil passage as the vehicle travel speed increases.