JP3782030B2

JP3782030B2 - Work vehicle turning control device

Info

Publication number: JP3782030B2
Application number: JP2002075940A
Authority: JP
Inventors: 之史山中; 吉弘上田
Original assignee: Kubota Corp
Current assignee: Kubota Corp
Priority date: 2002-03-19
Filing date: 2002-03-19
Publication date: 2006-06-07
Anticipated expiration: 2022-03-19
Also published as: JP2003267253A

Description

【０００１】
【発明の属する技術分野】
本発明は、左右一対の走行装置の走行状態を直進状態及び旋回状態に切り換え自在で、且つ、前記旋回状態において前記一対の走行装置夫々の走行速度を異ならせて旋回力を変更自在に構成されている旋回操作手段と、前記直進状態を指令する直進指令位置及び前記旋回状態を指令する旋回指令用操作領域の全範囲にわたり移動操作自在で、且つ、前記旋回指令操作領域において直進指令位置から離れる方向への移動量が大きいほど大きな旋回力となる旋回状態を指令する旋回指令手段とを備えた作業車の旋回制御装置に関する。
【０００２】
【従来の技術】
上記構成の作業車の旋回制御装置として、従来では、例えば、特開平１０−８４７４９号公報に示される構成のものがあった。
すなわち、前記旋回操作手段として、左右一対の走行装置を夫々各別に駆動する一対の静油圧式無段変速装置（ＨＳＴ）を備えて、それら一対の静油圧式無段変速装置による左右の走行装置の走行速度を同速度にすることで直進状態に切り換え、左右の走行装置の走行速度に速度差を与えて旋回状態に切り換える構成となっており、次のような旋回用の操作機構が備えられている。
つまり、前記旋回指令手段として回動操作自在な旋回操作具（ステアリングハンドル）が備えられ、その旋回操作具と一対の静油圧式無段変速装置夫々の変速用の被操作体（トラニオン軸）とを機械的に連動連係するリンク機構が備えられる構成となっており、旋回操作具を直進指令位置から左右の旋回方向に向けて回動操作させることにより、一対の静油圧式無段変速装置にて変速される左右の走行装置の走行速度の速度差が予め定められた特定の相関関係に従って連続的に変化するように、言い換えると、回動操作量が大きいほど大きい旋回力に変更させる構成である（以下、第１の従来技術という）。
具体的には、旋回操作具を旋回指令用操作領域にて直進指令位置から回動操作させるに伴って、旋回側の走行装置が反対側の走行装置と同一方向に駆動される状態であって、且つ、旋回側の走行装置の速度が反対側の走行装置の速度より低速となり、その速度差が徐々に大きくなる旋回状態、旋回側の走行装置が回転停止状態となる旋回状態、旋回側の走行装置が反対側の走行装置と逆方向に駆動される旋回状態、の夫々に順次切り換わる構成となっている。
【０００３】
又、従来では、旋回指令手段として、上記したような回転操作式の旋回操作具や、揺動操作式のレバー式の旋回操作具にて構成する場合のように、大きく移動操作させるものとは別に、旋回操作具における操作用の握り部に、その握り部を握り操作した手指にて操作可能なスイッチ式の指令手段を備えるものがある。
このような指操作式の指令手段は、車体を大きく旋回させるのではなく、例えば、圃場の作物の植立列に沿って走行させる場合に少しづつ車体の位置ずれを修正する必要があるときに、指操作によって少し車体を旋回させるような場合に利用するものであるが、従来では、このスイッチ式の指令手段による旋回状態としては、例えば小さめに設定された一定の旋回力となる特定の旋回状態が設定されており、指令手段が操作されるに伴って、常に、この特定の旋回状態になるように構成されていた。（以下、第２の従来技術という）。
【０００４】
【発明が解決しようとする課題】
上記第１の従来技術では、旋回指令手段を移動操作してその操作位置を変化させることで任意の旋回力による旋回状態を現出させることができるが、旋回操作具の操作位置と目標とする旋回力の相関関係が常に一定であるから、次のような面で未だ改善の余地があった。
【０００５】
つまり、上記第１の従来技術においては、旋回指令手段が前記旋回指令用操作領域のうち前記移動量が最も大きい最大操作位置に操作されたときには、常に、旋回側の走行装置が反対側の走行装置に対して予め定めた所定の速度差となるように逆方向に回転させる旋回状態で旋回が行われることになるが、例えば、旋回操作に不慣れな操作者が大きめの旋回力を得ようとして旋回指令手段を最大操作位置に操作したときに、常に、上記したような逆方向での回転による旋回状態で旋回が行われると、旋回力が大き過ぎて操作上の違和感を感じるおそれがある。そこで、旋回操作手段を旋回指令用操作領域の途中の適宜位置で位置調節しながら旋回力を調節しようとしても、その調節操作が適正に行えないおそれもある。又、逆に熟練作業者であれば、旋回指令手段を最大操作位置に操作したときに、上記逆方向での回転による旋回状態において、予め定めた所定の速度差となるように旋回側の走行装置を逆方向に回転させる状態では、まだ、旋回力が不足すると感じるような場合もある。
【０００６】
又、このような操作感覚の違いは、熟練度の違いに起因するものに限らず、そのときの作業状況の違いによっても生じることがある。例えば、圃場を走行する場合であれば、乾田のように硬い路面を走行するときは走行装置の駆動回転状態が地面に伝わり易く左右の速度差により旋回操作させ易いが、湿田のように軟弱な路面を走行するときには、走行装置がスリップするおそれがあり、走行装置の駆動回転状態が地面に伝わり難く旋回させ難くなる。従って、そのときの作業状況によっては、旋回指令手段を最大操作位置に操作したときに、旋回力が強すぎると感じたり、あるいは、旋回力が不足していると感じることがある。
【０００７】
又、上記第２従来技術のように手指にて操作可能なスイッチ式の指令手段にて旋回を指令する場合においても、同様に、その指令に伴って常に一定の旋回力となる特定の旋回状態が現出するものであるから、作業熟練度の違いや作業状況の違い等に起因して、操作者が、旋回操作を行うときにおいて、旋回力が強すぎると感じたり、あるいは、旋回力が不足していると感じることがある。
【０００８】
そこで、本発明はかかる点に着目してなされたものであり、その目的は、旋回操作を行うときにおいて、操作者が旋回力の過不足を感じないように適正な旋回力にて旋回操作を行うことが可能となる作業車の旋回制御装置を提供する点にある。
【０００９】
【課題を解決するための手段】
請求項１に記載の作業車の旋回制御装置は、左右一対の走行装置の走行状態を直進状態及び旋回状態に切り換え自在で、且つ、前記旋回状態において前記一対の走行装置のうちの旋回側の走行装置の走行速度を異ならせてかつ反対側の走行装置の走行速度を直進状態と同じ状態とする形態で旋回力を変更自在に構成されている旋回操作手段と、前記直進状態を指令する直進指令位置及び前記旋回状態を指令する旋回指令用操作領域の全範囲にわたり移動操作自在で、且つ、前記旋回指令操作領域において直進指令位置から離れる方向への移動量が大きいほど大きな旋回力となる旋回状態を指令する旋回指令手段とを備えたものであって、前記旋回指令手段が前記旋回指令範囲のうち前記移動量が最も大きい最大操作位置に操作されたときの旋回力を増減変化させる状態で、前記旋回指令手段の前記旋回指令用操作領域内での操作位置と目標とする旋回力の相関関係を変更設定自在な人為操作式の旋回力変更設定手段が設けられ、前記旋回操作手段が、前記旋回指令手段の指令情報、及び、前記旋回力変更設定手段の設定情報に基づいて、前記旋回指令手段の前記旋回指令用操作領域内での操作位置と前記旋回力変更設定手段にて設定された相関関係にて求められる前記目標とする旋回力となるように、前記一対の走行装置夫々の走行速度の速度差を異ならせるように構成されていることを特徴とする。
【００１０】
すなわち、操作者は、旋回指令手段を操作して旋回操作を行う前に、操作者の熟練度やそのときの作業状況等に応じて、前記旋回力変更設定手段を人為操作して、旋回指令手段の前記旋回指令用操作領域内での操作位置と目標とする旋回力の相関関係を変更設定する。その変更設定においては、旋回指令手段が旋回指令範囲のうち移動量が最も大きい最大操作位置に操作されたときの旋回力が増減変化することになる。
【００１１】
そして、旋回指令手段にて旋回を指令すると、旋回指令操作領域において直進指令位置から離れる方向への移動量が大きいほど大きな旋回力となる旋回状態を指令することになるが、このとき、旋回力変更設定手段の設定情報に基づいて相関関係にて求められる目標とする旋回力となるように、一対の走行装置夫々の走行速度の速度差を異ならせて旋回操作が行われることになる。
【００１２】
従って、操作者が大きな旋回力が必要であると感じて旋回指令手段を最大操作位置に操作させたときの旋回力は、旋回力変更設定手段にて操作者が適正なものとして任意に変更設定された旋回力になるので、旋回力が強すぎると感じたり、不足していると感じる等の不利がなく、適正な旋回力にて旋回操作を行うことが可能となる作業車の旋回制御装置を提供できるに至った。
【００１３】
請求項１に記載の作業車の旋回制御装置は、前記旋回力変更設定手段が、前記旋回指令手段が前記最大操作位置に操作されたときの旋回力を増減変化させる変更調整可能な全範囲を複数の領域に区分けして、その区分けした複数の領域のうちのいずれか一つに対応する設定状態に選択操作自在な領域選択手段と、その領域選択手段にて選択された領域内において、前記最大操作位置に操作されたときの前記旋回力を変更調整自在な変更調整手段とを備えて構成されていることを特徴とする。
【００１４】
例えば、旋回力を増減変化させる変更調整可能な全範囲において１つの調節手段にて変更調節させる構成とすることも考えられるが、このようにすると、変更調整可能な範囲を極力広くさせるようにすると、人為操作すべき調整範囲が広くなりすぎて、細かな微調節節操作が行えず、人為操作すべき調整範囲を狭くすると前記旋回力を増減変化させる変更調整可能な範囲がそれだけ狭くなってしまう。
そこで、前記変更調整可能な全範囲を複数の領域に区分けして、その区分けした複数の領域のうちのいずれか一つを領域選択手段にて選択して、その選択された領域内において、変更調整手段にて前記旋回力を変更調整させる構成とすることで、前記変更調整可能な範囲を狭くさせることなく、人為操作すべき調整範囲を特定の領域内に限定することで細かな微調節節操作を行うことも可能となって、使い勝手がよくなる。
【００１５】
請求項２記載の作業車の旋回制御装置は、左右一対の走行装置の走行状態を直進状態及び旋回状態に切り換え自在で、且つ、前記旋回状態において前記一対の走行装置のうちの旋回側の走行装置の走行速度を異ならせてかつ反対側の走行装置の走行速度を直進状態と同じ状態とする形態で旋回力を変更自在に構成されている旋回操作手段と、前記直進状態を指令する直進指令位置及び前記旋回状態を指令する旋回指令用操作領域の全範囲にわたり移動操作自在で、且つ、前記旋回指令操作領域において直進指令位置から離れる方向への移動量が大きいほど大きな旋回力となる旋回状態を指令する旋回指令手段とを備えたものであって、前記旋回指令手段における操作用の握り部に、その握り部を握り操作した手指にて操作可能に設けられて、指操作によって旋回操作を指令する旋回指令スイッチと、この旋回指令スイッチの指令に基づいて、旋回操作を行うときの目標とする旋回力を変更設定自在な人為操作式の目標旋回力設定手段とが設けられ、前記旋回操作手段が、前記旋回指令スイッチの指令に基づいて、前記目標旋回力設定手段にて設定された目標とする旋回力にて旋回走行するように、前記一対の走行装置夫々の走行速度の速度差を異ならせるように構成されていることを特徴とする。
【００１６】
すなわち、操作者は、旋回指令スイッチを操作して旋回操作を行う前に、操作者の熟練度やそのときの作業状況等に応じて、前記目標旋回力設定手段を人為操作して、旋回指令スイッチの指令に基づいて旋回操作を行うときの目標とする旋回力を変更設定する。
そして、旋回指令スイッチを操作して旋回操作を指令すると、目標旋回力設定手段にて設定された目標とする旋回力にて旋回走行するように、一対の走行装置夫々の走行速度の速度差を異ならせて旋回操作が行われることになる。
【００１７】
従って、旋回指令スイッチの指令に基づいて旋回操作されたときの旋回力は、目標旋回力設定手段にて操作者により適正なものとして任意に変更設定された適正な旋回力になるので、旋回力が強すぎると感じたり、不足していると感じる等の不利がなく、適正な旋回力にて旋回操作を行うことが可能となる作業車の旋回制御装置を提供できるに至った。
【００１８】
請求項３記載の作業車の旋回制御装置は、前記目標旋回力設定手段が、前記旋回指令手段における操作用の握り部に、その握り部を握り操作した手指にて操作可能に設けられていることを特徴とする。
【００１９】
すなわち、前記目標旋回力設定手段が、旋回指令スイッチと同様に前記握り部を握り操作した手指にて操作可能に設けられているから、この目標旋回力設定手段を操作するために旋回操作手段の握り部から手を離すことなく容易に変更設定操作を行うことができ、操作上の煩わしさがなくなる。
【００２０】
請求項３記載の作業車の旋回制御装置は、請求項１又は２において、前記旋回操作手段が、前記左右一対の走行装置の夫々の走行速度を各別に無段階に変速する一対の無段変速装置と、その一対の無段変速装置を夫々各別に変速操作する一対のアクチュエータと、そのアクチュエータの動作を制御する制御手段とを備えて構成され、前記制御手段が、前記一対のアクチュエータを制御するよう構成されていることを特徴とする。
【００２１】
すなわち、一対のアクチュエータによって一対の無段変速装置を夫々各別に変速操作することで、左右一対の走行装置の夫々の走行速度を各別に無段階に変速することができる。従って、左右一対の走行装置の夫々の走行速度の速度差を無段階に異ならせることで、旋回力を無段階に変更させることが可能となり、段階的に旋回力を切り換えるような構成のものに比べて、旋回操作を極力滑らかに行うときができるとともに、目標とする旋回力を無段階に変化させることができるので、操作者の操作感覚に合う最も適切な旋回力にて旋回操作を行うことが可能となり、請求項１又は２を実施するのに好適な手段が得られる。
【００２２】
【発明の実施の形態】
〔第１実施形態〕
以下、本発明に係る作業車の旋回制御装置の第１実施形態を、作業車の一例としてのコンバインに適用した場合について図面に基づいて説明する。
【００２３】
図１に作業車の一例であるコンバインの全体側面が示されており、このコンバインは、走行装置の一例である左右一対のクローラ式走行装置１Ｒ，１Ｌの駆動で走行する走行機体２の前部に、植立穀稈を刈り取って後方に向けて搬送する刈取搬送装置３を昇降可能に連結し、走行機体２に、刈取搬送装置３からの刈取穀稈を受け取って脱穀・選別処理を施す脱穀装置４と、脱穀装置４からの穀粒を貯留する穀粒タンク５とを搭載するとともに、穀粒タンク５の前方箇所に搭乗運転部６を形成することによって構成されている。
【００２４】
図２に示すように、このコンバインは、エンジン７からの動力を、ベルトテンション式の主クラッチ８を介してミッションケース９の入力軸１０に伝達し、この入力軸１０から走行用の一対の静油圧式無段変速装置１１Ｒ，１１Ｌ（無段変速装置の一例）に分配伝達し、走行用の一方の静油圧式無段変速装置１１Ｌによる変速後の動力を左側のギヤ式副変速装置１３Ｌを介して左側のクローラ式走行装置１Ｌに伝達し、走行用の他方の静油圧式無段変速装置１１Ｒによる変速後の動力を、右側のギヤ式副変速装置１３Ｒを介して右側のクローラ式走行装置１Ｒに伝達するようにして走行駆動用の伝動機構を構成している。一方、エンジン７からの動力が作業用の静油圧式無段変速装置１２にも供給され、その作業用の静油圧式無段変速装置１２による変速後の動力を、ベルトテンション式の刈取クラッチ１４を介して刈取搬送装置３に伝達するようにして刈取作業用の伝動機構を構成している。
【００２５】
左右のギヤ式副変速装置１３Ｒ，１３Ｌは、前記各静油圧式無段変速装置１１Ｒ、１１Ｌの変速後の動力を高低２段に切り換え自在並びに動力遮断状態に切り換え自在な副変速機構として構成されている。又、それらの伝動軸１５Ｒ，１５Ｌ同士を断続させることで、左右のクローラ式走行装置１Ｒ，１Ｌを一体的に連結して等速駆動する状態と、左右のクローラ式走行装置１Ｒ，１Ｌを各別に変速操作することを許容する状態とに切り換える多板式の油圧クラッチ１６が介装されている。
【００２６】
そして、図３に示すように、走行用の各静油圧式無段変速装置１１Ｒ，１１Ｌを各別に変速操作する油圧式の走行用操作機構３０と、作業用の静油圧式無段変速装置１２を変速操作する油圧式の作業用操作機構３６と、油圧クラッチ１６に対する作動油の流動状態を切り換える電磁切換弁３２とが夫々備えられている。前記走行用操作機構３０は、走行用の各静油圧式無段変速装置１１Ｒ，１１Ｌの夫々におけるトラニオン軸２９，２９に連動連結された一対の複動型の油圧シリンダ３３Ｒ，３３Ｌ（アクチュエータの一例）と、これらの各油圧シリンダ３３Ｒ，３３Ｌに対する正逆方向夫々の操作に対応する一対の油室に作動油を供給する状態と供給を停止する状態とに切り換え自在な一対の２位置切換式の給油用の油圧電磁弁３４Ａと、前記一対の油室から作動油を排出する状態と排出を停止する状態とに切り換え自在な一対の２位置切換式の排油用の油圧電磁弁３４Ｂとを備えて構成されている。前記各油圧シリンダ３３Ｒ，３３Ｌは、内装されるバネの付勢力により中立位置に復帰付勢される構成となっている。
【００２７】
前記作業用操作機構３６も同様に、作業用の静油圧式無段変速装置１２におけるトラニオン軸３７に連動連結されるとともに、内装されるバネの付勢力により中立位置に復帰付勢される構成の複動型の油圧シリンダ４０と、この油圧シリンダ４０に対する正逆方向夫々の操作に対応する一対の油室に作動油を供給する状態と供給を停止する状態とに切り換え自在な一対の２位置切換式の給油用の油圧電磁弁４１Ａと、前記一対の油室から作動油を排出する状態と排出を停止する状態とに切り換え自在な一対の２位置切換式の排油用の油圧電磁弁４１Ｂとを備えて構成されている。
【００２８】
前記各給油用の油圧電磁弁３４Ａ，４１Ａは、バネの付勢力によってスプールを給油停止状態に移動付勢する構成となっており、ソレノイドによる電磁力によってバネの付勢力に抗してスプールを移動操作して作動油を供給する状態に切り換える構成となっており、又、前記各排油用の油圧電磁弁３４Ｂ，４１Ｂは、バネの付勢力によってスプールを排出状態に移動付勢される構成となっており、ソレノイドによる電磁力によってバネの付勢力に抗してスプールを移動操作して作動油の排出を停止する状態に切り換わる構成となっている。
又、搭乗運転部６には、前後方向に揺動操作可能な単一の副変速レバー２５が設けられ、この副変速レバー２５は、ギヤ式副変速装置１３Ｒ、１３Ｌに連係されており、副変速レバー２５の操作によって、走行用の各静油圧式無段変速装置１１Ｒ，１１Ｌによる変速後の動力を高低２段に変速できるようになっている。
【００２９】
上記したような静油圧式無段変速装置１１Ｒ，１１Ｌの変速動作について説明を加えると、例えば図４に示すように、トラニオン軸２９の変速位置が中立位置Ｎを含む所定幅を有する中立域にあれば変速出力（走行速度）は零となり、トラニオン軸２９の変速位置がその中立域から所定方向に回動操作されると前進方向への走行速度が無段階に増速操作され、トラニオン軸２９が中立域から所定方向と反対方向に回動操作されると後進方向への走行速度が無段階に増速操作される構成となっている。
【００３０】
搭乗運転部６には、前後方向に沿って所定の前後操作範囲にわたり揺動操作可能な主変速レバー２４、及び、左右方向に沿って所定の左右操作範囲にわたり揺動操作可能な旋回指令手段としての旋回レバー２６などが装備されている。そして、図３に示すように、主変速レバー２４の操作位置を検出する変速レバーセンサ２７と、旋回レバー２６の操作位置を検出する旋回レバーセンサ２８とが夫々設けられ、それらは共に回転式のポテンショメータにて構成されている。
【００３１】
又、一対の静油圧式無段変速装置１１Ｒ，１１Ｌには、それらの出力回転速度を各別に検出する変速出力検出手段としての回転速度センサ４４，４５と、夫々の静油圧式無段変速装置１１Ｒ，１１Ｌの変速位置、すなわち、一対の油圧シリンダ３３Ｒ，３３Ｌによる夫々のトラニオン軸２９の操作角度を検出する変速位置検出手段としての変速位置センサ４６，４７とが夫々備えられている。
【００３２】
そして、前記油圧シリンダ３３Ｒ，３３Ｌ，４０の動作を制御する制御手段としてのマイクロコンピュータ利用の制御装置３１が備えられ、この制御装置３１は、前記変速レバーセンサ２７及び前記旋回レバーセンサ２８の検出情報に基づいて、一対の静油圧式無段変速装置１１Ｒ，１１Ｌの夫々の目標回転速度を求めて、その求めた目標回転速度に対応する前記各トラニオン軸２９の目標変速位置を設定して、前記各変速位置センサ４６，４７の検出値が前記各目標変速位置になるように前記一対の油圧シリンダ３３Ｒ，３３Ｌの作動を制御する走行制御を実行するよう構成されている。
【００３３】
すなわち、旋回レバー２６が直進指令位置に操作されて直進が指令されている状態で、主変速レバー２４が操作可能範囲のほぼ中間に位置する中立位置（停止指令位置に対応する）に操作されると走行停止状態となり、中立位置から前進側へ揺動操作されるとそれに伴って前進側への走行速度が無段階で増速され、中立位置から後進側へ操作されるとそれに伴って後進側への走行速度が無段階で増速されるように、一対の油圧シリンダ３３Ｒ，３３Ｌの作動を制御する構成となっており、主変速レバー２４が所定位置で固定されると、その位置にて指令される目標走行速度で車体が直進走行するように、一対の油圧シリンダ３３Ｒ，３３Ｌの作動を制御するのである。
又、制御装置３１は、主変速レバー２４が操作されて所定速度で走行しているときに、旋回レバー２６が直進指令位置から左右いずれかの旋回指令用操作領域に揺動操作されると、前記直進指令位置から離れる側に操作されるほど旋回半径が小さくなる、言い換えると、大きな旋回力となる旋回状態を指令するように走行用の各油圧シリンダ３３Ｒ，３３Ｌの作動を制御するよう構成されている。
【００３４】
そして、旋回レバー２６が前記旋回指令用操作領域のうち移動量が最も大きい最大操作位置に操作されたときの旋回力を増減変化させる状態で、旋回レバー２６の旋回指令用操作領域での操作位置と目標とする旋回状態との関係を変更設定自在な人為操作式の旋回力変更設定手段４２が設けられている。
【００３５】
前記旋回力変更設定手段４２は、旋回レバー２６が最大操作位置に操作されたときの旋回力を増減変化させる変更調整可能な全範囲を複数の領域に区分けして、その区分けした複数の領域のうちのいずれか一つに対応する設定状態に選択操作自在な領域選択手段と、その領域選択手段にて選択された領域内において、前記最大操作位置に操作されたときの前記旋回力を変更調整自在な変更調整手段とを備えて構成されている。
【００３６】
説明を加えると、図６に、旋回レバー２６の操作位置に対する旋回側のクローラ走行装置の減速の度合い、言い換えると、左右クローラ走行装置の速度差による旋回力の大きさの変化を示しており、この図に示すように、旋回レバー２６が最大操作位置に操作されたときの旋回力を増減変化させる変更調整可能な全範囲として、図６のラインＬ１に示す速度差零状態からライン５で示す最大速度差設定状態まで変更調整可能に構成され、そのような特性が予め設定されて、図示しないメモリに書き込み記憶されている。
そして、このような変更調整可能な全範囲を３つの領域Ａ，Ｂ，Ｃに区分けして、３つの領域Ａ，Ｂ，Ｃのいずれかに切り換えるための前記領域選択手段としての３接点式の領域選択スイッチ４２ａが設けられており、この領域選択スイッチ４２ａによる切換指令が制御装置３１に与えられて、制御装置３１は、その切換指令に基づいて領域を切り換えて制御を実行するよう構成されている。
【００３７】
図６のラインＬ１は旋回レバー２６を操作しても左右のクローラ走行装置の走行速度が同じ状態となる直進状態を示し、ライン５で示す最大速度差設定状態においては、旋回レバー２６を前記最大操作位置に操作したときには、旋回側のクローラ走行装置が反対側のクローラ走行装置の駆動回転方向とは逆回転方向に、旋回側のクローラ走行装置の走行速度と略同速度で駆動する状態、つまり、一対のクローラ走行装置が互いに逆方向に同速度で回転駆動されて、車体がスピンターンを行う状態である。
又、図中のラインＬ２に示す状態では、旋回レバー２６が最大操作位置にまで操作されると、旋回側のクローラ走行装置の走行速度が反対側のクローラ走行装置の走行速度Ｖの約１／３の速度にまで減速される状態となる。ラインＬ３に示す状態では、旋回レバー２６が最大操作位置にまで操作されると、旋回側のクローラ走行装置の走行速度が零となるまで減速され、ラインＬ４に示す状態では、旋回レバー２６が最大操作位置にまで操作されると、旋回側のクローラ走行装置の走行速度が反対側のクローラ走行装置の駆動回転方向とは逆回転方向で、反対側のクローラ走行装置の速度の約１／３の速度になる。
【００３８】
又、操縦部パネルには、前記変更調整手段として、ポテンショメータにて構成された調節操作具４２ｂが備えられており、上記したような各旋回モードのいずれかに設定されている状態で、この調節操作具４２ｂを調節操作することで、領域選択スイッチ４２ａにて選択された領域内において、前記最大操作位置に操作されたときの前記旋回力を変更調整自在に構成されている。すなわち、領域選択スイッチ４２ａにて領域Ａが選択されている状態で、調節操作具４２ｂを最も旋回力小側に操作すると、旋回レバー２６の操作位置と目標とする旋回力に対応する左右走行装置の速度差との変化特性が図６のラインＬ１に設定され、旋回力調節操作具４２ｂを最も旋回力大側に操作すると図６のラインＬ２に設定される。旋回力調節操作具４２ｂがそれらの中間位置に操作されると、その操作量に応じて前記変化特性がラインＬ１とラインＬ２との間で無段階に変更調整される。尚、変化特性としては、旋回レバー２６の操作位置の変化に対する速度差の変化がほぼリニアに変化する状態となっている。
又、領域選択スイッチ４２ａにて領域Ｂ，Ｃが選択されても同様に、調節操作具４２ｂの操作量に応じて前記変化特性がその領域内において無段階に変更調整される。
【００３９】
従って、領域選択スイッチ４２ａの選択操作及び調節操作具４２ｂの操作によって、旋回レバー２６の旋回指令用操作領域での操作位置と目標とする旋回力との関係、すなわち、旋回レバー２６の操作による左右のクローラ走行装置の速度比率の特性として１本のラインが特定されることになる。
【００４０】
一方、図５に示すように、主変速レバー２４の操作位置に対する目標車速の変化の特性が予め設定されて記憶されており、制御装置３１は、上記したような旋回レバー２６の操作による左右のクローラ走行装置１Ｒ，１Ｌの速度比率の特性と、図５に示される主変速レバー２４の操作位置にて定まる目標車速とに基づいて、左右一対のクローラ走行装置１Ｒ，１Ｌに対する静油圧式無段変速装置１１Ｒ，１１Ｌの夫々の目標回転速度を求める処理を実行する。
そして、図７に示すように、各目標回転速度に対応するトラニオン軸２９、２９の目標変速位置を求めるために設定された基準情報に基づいて、上記したようにして求めた目標回転速度に対応するようなトラニオン軸２９，２９の目標変速位置を夫々設定して、各変速位置センサ４６，４７にて検出される一対のトラニオン軸２９，２９の変速位置が夫々の目標変速位置になるように、対応する油圧シリンダ３３Ｒ，３３Ｌを制御する。すなわち、目標とする旋回力となるように、左右一対の静油圧式無段変速装置１１Ｒ，１１Ｌ夫々の走行速度の速度差を異ならせるように制御する。
【００４１】
以下、制御フローチャートに基づいて、制御装置３１による走行制御の制御動作について具体的に説明する。
つまり、制御装置３１は、図８に示すように、変速レバーセンサ２７にて検出される主変速レバー２４の操作位置、並びに、旋回レバーセンサ２８にて検出される旋回レバー２６の操作位置の検出結果に基づいて、左右一対の静油圧式無段変速装置１１Ｒ，１１Ｌの夫々の目標回転速度を求める（ステップ１、２）。そして、その求めた夫々の目標回転速度に対応させて一対のトラニオン軸２９、２９に対する夫々の目標変速位置を設定する（ステップ３）。
次に、変速位置センサ４６，４７にて検出される各トラニオン軸２９，２９の変速位置が前記各目標変速位置になるように、前記各油圧電磁弁３４Ａ，３４Ｂの作動を制御して走行用の各油圧シリンダ３３Ｒ，３３Ｌを作動させる変速操作を実行する（ステップ４）。つまり、変速位置の検出情報に基づくフィードバック制御を実行するのである。
このようにして、左右一対の静油圧式無段変速装置１１Ｒ，１１Ｌ夫々の走行速度をそのときの指令状態に対応するような速度にして、旋回操作状態では、目標とする旋回力となるように、左右一対の静油圧式無段変速装置１１Ｒ，１１Ｌ夫々の走行速度の速度差を異ならせるように制御することになる。
【００４２】
上記左右一対の静油圧式無段変速装置１１Ｒ，１１Ｌ、一対の油圧シリンダ３３Ｒ，３３Ｌ、走行用操作機構３０、及び、制御装置３１の夫々により旋回操作手段が構成される。
【００４３】
このような構成にすると、旋回レバー２６を最大操作位置に操作した状態における旋回状態を操作者の操作が行い易い旋回力に変更調整することができ、枕地での旋回操作や車体の向き変更操作のときの操作を行い易いものにすることができる。
【００４４】
〔第２実施形態〕
以下、本発明に係る作業車の旋回制御装置の第２実施形態を図面に基づいて説明する。
この実施形態は、旋回操作を指令する手段として、前記旋回レバー２６とは別に指操作式の旋回指令スイッチ５０が設けられている点と、制御装置３１により旋回指令スイッチ５０の指令に基づく後述するような旋回用制御動作が行われる点を除き、その他の構成は上記第１実施形態と同様であるから、構成が異なる部分についてのみ説明し、同じ構成については説明は省略する。
【００４５】
つまり、この実施形態では、旋回レバー２６における操作用の握り部２６ａに、その握り部２６ａを握り操作した手指にて操作可能であって指操作によって旋回操作を指令する旋回指令スイッチ５０が設けられている。この旋回指令スイッチ５０は、図９、図１０に示すように、右方向の旋回を指令する右旋回スイッチ５０Ｒと左方向への旋回を指令する左旋回スイッチ５０Ｌとからなり、これらの指令情報が前記制御装置３１に与えられる構成となっている。そして、制御装置３１は、旋回レバー２６が直進指令位置にある状態で、この旋回指令スイッチ５０にて旋回が指令されると、予め設定された目標とする旋回力となるように、前記左右のクローラ走行装置１Ｒ，１Ｌ夫々の走行速度の速度差を異ならせるように制御するよう構成されている。尚、旋回レバー２６が前記旋回指令用操作領域に揺動操作され、旋回状態が指令されている場合には、旋回レバー２６の操作による旋回状態が優先され、旋回指令スイッチ５０が操作されてもその指令に基づいて操作は行われない。
【００４６】
そして、この旋回指令スイッチ５０の指令に基づいて、旋回操作を行うときの前記目標とする旋回力を変更設定自在な人為操作式の目標旋回力設定手段としてのポテンショメータからなる旋回力調節具５１が設けられている。この旋回力調節具５１は、旋回レバー２６における操作用の握り部２６ａに、その握り部２６ａを握り操作した手指にて操作可能に設けられている。
【００４７】
図１１に示すように、旋回力調節具５１を、基準となる操作状態（操作量が零である状態）から操作量が大きくなるほど、旋回操作を行うときの目標とする旋回力に対応する左右のクローラ走行装置１Ｒ，１Ｌ夫々の走行速度の速度差の変化特性が予め設定されて図示しないメモリに書き込み記憶されており、制御装置３１は、旋回指令スイッチ５０が押し操作されて旋回操作が指令されると、その旋回指令スイッチ５０が押し操作されている間、指令された方向に向かって車体を旋回させるように旋回側のクローラ走行装置が低速となる状態で、且つ、左右のクローラ走行装置１Ｒ，１Ｌ夫々の走行速度の速度差が、旋回力調節具５１の操作位置と前記変化特性とから求められた速度差になるように、走行用の各油圧シリンダ３３Ｒ，３３Ｌの動作を制御するように構成されている。尚、各油圧シリンダ３３Ｒ，３３Ｌに対する制御の構成等、旋回操作手段の構成は上記第１実施形態と同様である。
【００４８】
つまり、旋回指令スイッチ５０が押し操作されている間、左右のクローラ走行装置１Ｒ，１Ｌが旋回力調節具５１にて変更設定された速度差で駆動され、その速度差に対応する旋回力で旋回操作が行われることになる。そして、旋回指令スイッチ５０の押し操作が解除されると、旋回操作が終了して前記主変速レバー２４にて設定された車速で直進走行する状態に切り換わる。
【００４９】
従って、この実施形態では、旋回力調節具５１を操作することで、旋回指令スイッチ５０の指令による旋回操作における旋回力を無段階に変更調整することができ、刈取作業走行を行っているときに、作物列に沿うるように進行方向を微調節するような場合に、操作者が操作し易い状態で旋回させることができ、操作感覚を良好なものにできる。
【００５０】
〔別実施形態〕
以下、別実施形態を列記する。
【００５１】
（１）上記第１実施形態では、前記旋回レバー２６が最大操作位置に操作されたときの旋回力を増減変化させる変更調整可能な全範囲として、速度差零の状態から一対のクローラ走行装置が互いに逆方向に同速度で回転駆動されて車体がスピンターンを行う最大速度差状態まで変更調整可能に構成されるものを例示したが、このような構成に限らず、最大速度差状態として、前記旋回レバー２６が最大操作位置に操作されたときに旋回側のクローラ走行装置が反対側のクローラ走行装置の速度に対して逆方向に約１／３程度の速度で駆動される状態に設定したり、前記旋回レバー２６が最大操作位置に操作されたとき旋回側のクローラ走行装置が速度零状態となる状態に設定する等、各種の形態で実施することができる。
【００５２】
（２）上記第１実施形態では、前記旋回力変更設定手段が、領域選択手段としての領域選択スイッチ４２ａと、変更調整手段としての調節操作具４２ｂとを備えて構成されるものを例示したが、そのような変更調整手段としては、前記最大操作位置に操作されたときの前記旋回力を無段階に変更させるものに限らず、複数の段階に階段状に切り換える構成でもよい。
【００５３】
（３）上記第１実施形態では、旋回指令手段として、揺動操作式の旋回レバーを例示したが、このような構成に限らず、回動操作自在なステアリングハンドルで構成してもよい。又、旋回指令手段の直進指令位置としては、移動方向に所定の不感帯域を有するものであってもよい。
【００５４】
（４）上記第１実施形態では、変更調整手段としての調節操作具４２ｂが操縦部パネルに設けられる構成としたが、例えば、旋回レバーの握り部に、その握り部を握り操作した手指にて操作可能に設けられるものでよい。
【００５６】
（６）上記第２実施形態では、旋回指令スイッチ５０が押し操作されている間、設定された旋回力で旋回操作が行われる構成としたが、このような構成に限らず、旋回指令スイッチ５０が押し操作されている間は、例えば、設定された旋回力で旋回操作を行う状態と、旋回操作を停止して直進状態にする状態とを、設定短時間毎に間欠的に繰り返すような操作形態としたり、あるいは、旋回指令スイッチ５０が押し操作される毎に設定短時間だけ設定された旋回力で旋回操作が行われるような操作形態とする等、各種の操作形態で実施することができる。
【００５７】
（７）上記各実施形態では、前記旋回操作手段として、左右一対の走行装置の夫々の走行速度を各別に無段階に変速する静油圧式無段変速装置と、それらを各別に変速操作する一対のアクチュエータとしての油圧シリンダと、その油圧シリンダの動作を制御する制御手段とを備えて構成されるものを例示したが、このような構成に代えて、次の（イ）〜( ニ）に記載するような構成でもよい。
（イ）前記一対の無段変速装置として、静油圧式無段変速装置に代えて、例えば、ベルト式無段変速装置やテーパコーン型の無段変速装置、及び、走行方向を前後で切り換えるための前後進切換機構等を備える構成としてもよい。
（ロ）アクチュエータとして、前記油圧シリンダに代えて、電動モータや油圧モータ等、他のアクチュエータを用いるようにしてもよい。
（ハ）前記アクチュエータと制御手段とを備えるものに代えて、旋回指令手段としての旋回レバーの操作によって、前記一対の無段変速装置夫々の変速用の被操作体を速度差を付ける状態で一体的に連動操作させるリンク機構を備える構成として、そのリンク機構における機械的なリンク比率等を変更させることで、旋回レバーの前記旋回指令用操作領域内での操作位置と目標とする旋回力の相関関係を変更設定させるような構成としてもよい。
（ニ）上記したような無段変速装置を設ける構成に代えて、前記各クローラ走行装置に対する伝動系に介装したクラッチを電気的に短時間で入り切りさせる、所謂、パルス幅変調制御によって左右のクローラ走行装置の速度差を変更調整するような構成としてもよい。
要するに、旋回操作手段としては、一対の走行装置夫々の走行速度を異ならせて旋回力を変更することができる構成であればよい。
【００５８】
（８）上記実施形態では、作業車としてコンバインを例示したが、本発明はコンバインに限らず、人参収穫機や大根収穫機など他の農作業車でもよく、又、農作業車に限らず建設機械等の作業車でもよい。
【図面の簡単な説明】
【図１】コンバインの全体側面図
【図２】伝動構造を示す概略構成図
【図３】制御ブロック図
【図４】変速位置と変速出力との関係を示す図
【図５】主変速レバー操作位置と目標車速との関係を示す図
【図６】旋回レバーの操作位置と左右走行装置の速度比の関係を示す図
【図７】目標回転速度と目標変速位置との関係を示す図
【図８】制御動作のフローチャート
【図９】第２実施形態の制御ブロック図
【図１０】第２実施形態の旋回指令スイッチを示す図
【図１１】第２実施形態の調整具操作量と左右速度差との関係を示す図
【符号の説明】
１Ｒ、１Ｌ走行装置
１１Ｒ、１１Ｌ無段変速装置
２６旋回指令手段
２６ａ握り部
３１制御手段
３３Ｒ、３３Ｌアクチュエータ
４２旋回力変更設定手段
４２ａ領域選択手段
４２ｂ変更調整手段
５０旋回指令スイッチ
５１目標旋回力設定手段[0001]
BACKGROUND OF THE INVENTION
The present invention is configured such that the traveling state of the pair of left and right traveling devices can be switched between a straight traveling state and a turning state, and the turning force can be changed by changing the traveling speed of each of the pair of traveling devices in the turning state. The turning operation means, a straight command position for commanding the straight travel state, and a swivel command operation region for commanding the swivel state can be moved and moved away from the straight command position in the turn command operation region. The present invention relates to a turning control device for a work vehicle including turning command means for instructing a turning state in which the turning force becomes larger as the amount of movement in a direction becomes larger.
[0002]
[Prior art]
Conventionally, as a turning control device for a work vehicle having the above configuration, for example, there has been a configuration shown in Japanese Patent Laid-Open No. 10-84749.
That is, as the turning operation means, a pair of hydrostatic continuously variable transmissions (HST) that respectively drive a pair of left and right traveling devices are provided, and left and right traveling devices by the pair of hydrostatic continuously variable transmissions. The same traveling speed is used to switch to the straight traveling state, and the traveling speed of the left and right traveling devices is switched to the turning state by giving a speed difference. The following turning operation mechanism is provided. ing.
That is, a turning operation tool (steering handle) that can be freely turned is provided as the turning command means, and the turning operation tool and a pair of hydrostatic continuously variable transmission devices (transnion shafts) for shifting. A link mechanism that mechanically links the two is provided, and by turning the turning operation tool from the straight advance command position toward the left and right turning directions, a pair of hydrostatic continuously variable transmissions can be obtained. The speed difference between the left and right traveling devices that are shifted in this manner is changed continuously according to a predetermined correlation, in other words, the larger the turning operation amount, the larger the turning force is changed. (Hereinafter referred to as the first prior art).
Specifically, as the turning operation tool is turned from the straight advance command position in the turning command operation area, the turning-side traveling device is driven in the same direction as the opposite-side traveling device. In addition, a turning state in which the speed of the turning-side traveling device is lower than the speed of the opposite-side traveling device and the speed difference gradually increases, a turning state in which the turning-side traveling device is in a rotation stopped state, The traveling device is configured to sequentially switch to a turning state in which the traveling device is driven in the opposite direction to the opposite traveling device.
[0003]
Also, conventionally, as a turning command means, what is made to move greatly as in the case where it is constituted by a rotating operation type turning operation tool as described above or a swing operation type lever type turning operation tool, In another, there is a switch-type command means that can be operated by a finger that is operated by gripping the grip portion in the grip portion for operation in the turning operation tool.
Such a finger-operated command means does not turn the vehicle body greatly, but, for example, when it is necessary to correct a vehicle body position shift little by little when traveling along a planting row of crops in a field. This is used when the vehicle body is slightly turned by a finger operation. Conventionally, as a turning state by this switch type command means, for example, a specific turning with a constant turning force set to a small value is used. The state is set, and the specific turning state is always set as the command means is operated. (Hereinafter referred to as the second prior art).
[0004]
[Problems to be solved by the invention]
In the first prior art, a turning state by an arbitrary turning force can be revealed by moving the turning command means and changing its operating position. Since the correlation of the turning force is always constant, there is still room for improvement in the following aspects.
[0005]
That is, in the first prior art, when the turn command means is operated to the maximum operation position where the movement amount is the largest in the turn command operation area, the turning side travel device always runs on the opposite side. Turning is performed in a turning state in which the device rotates in the opposite direction so as to have a predetermined speed difference with respect to the device. For example, an operator unfamiliar with the turning operation tries to obtain a large turning force. When the turning command means is operated to the maximum operating position, if the turning is always performed in the turning state by the rotation in the reverse direction as described above, the turning force may be too large, and there may be a sense of incongruity in operation. Therefore, even if an attempt is made to adjust the turning force while adjusting the position of the turning operation means at an appropriate position in the middle of the turning command operation area, the adjusting operation may not be performed properly. On the other hand, if it is a skilled worker, when the turning command means is operated to the maximum operating position, the turning side travels so that a predetermined speed difference is obtained in the turning state by the rotation in the reverse direction. In a state where the device is rotated in the reverse direction, it may still be felt that the turning force is insufficient.
[0006]
Further, such a difference in operation feeling is not limited to that caused by a difference in skill level, but may also be caused by a difference in work situation at that time. For example, when traveling on a farm field, when traveling on a hard road surface such as a dry paddy field, the drive rotation state of the traveling device is easily transmitted to the ground, and it is easy to make a turning operation due to the difference in speed between the left and right, but it is as soft as a wet paddy field. When traveling on the road surface, the traveling device may slip, and the driving rotation state of the traveling device is not easily transmitted to the ground, making it difficult to turn. Therefore, depending on the work situation at that time, when the turning command means is operated to the maximum operating position, it may be felt that the turning force is too strong or the turning force is insufficient.
[0007]
Similarly, when a turn is commanded by a switch-type command means that can be operated with a finger as in the second prior art, a specific turning state in which a constant turning force is always provided in accordance with the command. Therefore, the operator feels that the turning force is too strong when the turning operation is performed or the turning force is You may feel deficient.
[0008]
Therefore, the present invention has been made paying attention to such a point, and its purpose is to perform a turning operation with an appropriate turning force so that the operator does not feel excessive or insufficient turning force when performing the turning operation. It is in the point which provides the turning control apparatus of the working vehicle which can be performed.
[0009]
[Means for Solving the Problems]
The turning control device for a work vehicle according to claim 1 is capable of switching a traveling state of the pair of left and right traveling devices to a straight traveling state and a turning state, and in the turning state, the pair of traveling devices. Of the swivel side travel device With different running speeds And in the form that the traveling speed of the opposite traveling device is the same as the straight traveling state The turning operation means configured to freely change the turning force, the straight movement command position for instructing the straight movement state, and the rotation command operation area for instructing the turning state are movable, and the turning command A turning command means for commanding a turning state in which the turning force becomes a larger turning force as the amount of movement in the direction away from the rectilinear command position is larger in the operation region, wherein the turning command means includes the turning command range in the turning command range. The correlation between the operation position of the turn command means in the turn command operation area and the target turn force is changed in a state in which the turning force when operated to the maximum operating position with the largest movement amount is changed. A freely manipulating type turning force change setting means that can be set is provided, and the turning operation means is based on command information of the turning command means and setting information of the turning force change setting means. Then, the pair of the turn command means is set so as to obtain the target turning force determined by the correlation set by the turning force change setting means and the operation position in the turning command operation area. The present invention is characterized in that the traveling devices are configured to have different speed differences in traveling speed.
[0010]
That is, the operator manually operates the turning force change setting means in accordance with the skill level of the operator and the work situation at that time before performing the turning operation by operating the turning instruction means. The correlation between the operation position of the means within the turning command operation area and the target turning force is changed and set. In the change setting, the turning force changes when the turning command means is operated to the maximum operation position where the movement amount is the largest in the turning command range.
[0011]
Then, when turning is commanded by the turning command means, a turning state in which the turning force becomes larger as the amount of movement in the direction of the turn command operation in the direction away from the straight-ahead command position is larger is determined. The turning operation is performed with different speed differences between the traveling speeds of the pair of traveling devices so as to obtain a target turning force determined by the correlation based on the setting information of the change setting means.
[0012]
Therefore, the turning force when the operator feels that a large turning force is necessary and operates the turning command means to the maximum operating position is arbitrarily changed and set by the turning force change setting means as appropriate by the operator. The turning control device for a work vehicle enables the turning operation with an appropriate turning force without the disadvantage of feeling that the turning force is too strong or insufficient. I was able to provide.
[0013]
Claim 1 The work vehicle turning control device described in ,in front The turning force change setting means divides the entire adjustable range for changing the turning force when the turning command means is operated to the maximum operation position into a plurality of areas, and the plurality of divided areas An area selecting means that can be selected and operated in a setting state corresponding to any one of the above, and changing the turning force when operated to the maximum operating position in the area selected by the area selecting means It is characterized by comprising an adjustable change adjusting means.
[0014]
For example , Turning It may be possible to change and adjust the torque in the entire range that can be adjusted by one adjustment means, but in this way, if the range that can be changed and adjusted is made as wide as possible, artificial operation is possible. The adjustment range to be adjusted is too wide to perform fine fine adjustment clause operation, and if the adjustment range to be manually operated is narrowed, the changeable adjustment range for increasing / decreasing the turning force is narrowed accordingly.
Therefore, the entire range that can be changed and adjusted is divided into a plurality of areas, and any one of the divided areas is selected by the area selection means, and the change is made within the selected area. By adopting a configuration in which the turning force is changed and adjusted by the adjusting means, the adjustment range to be artificially operated is limited to a specific region without narrowing the range that can be changed and adjusted. It is also possible to perform operations, making it easy to use hand egoism Na The
[0015]
Claim 2 The working vehicle turning control device described above is capable of switching the traveling state of the pair of left and right traveling devices between a straight traveling state and a turning state, and the pair of traveling devices in the turning state. Of the swivel side travel device With different running speeds And in the form that the traveling speed of the opposite traveling device is the same as the straight traveling state The turning operation means configured to freely change the turning force, the straight movement command position for instructing the straight movement state, and the rotation command operation area for instructing the turning state are movable, and the turning command A turning command means for commanding a turning state in which the turning force becomes a larger turning force as the amount of movement in the direction away from the rectilinear command position in the operation region increases, and the grip for operation in the turning command means includes: A turn command switch that is provided so that it can be operated by a finger that is operated by gripping the grip portion, and that commands turning operation by finger operation, and a target turning when performing turning operation based on the command of the turning command switch And an artificially operated target turning force setting means capable of changing and setting the force, the turning operation means based on the command of the turning command switch. As turning at the turning force as a target that has been set at a constant section, characterized in that it is configured to vary the speed difference between the pair of traveling devices each running speed.
[0016]
That is, the operator manually operates the target turning force setting means according to the skill level of the operator and the work situation at that time before performing the turning operation by operating the turning command switch. Based on the switch command, the target turning force when turning operation is changed and set.
When the turning command switch is operated and the turning operation is instructed, the speed difference between the traveling speeds of the pair of traveling devices is set so that the turning operation is performed with the target turning force set by the target turning force setting means. The turning operation is performed differently.
[0017]
Accordingly, the turning force when the turning operation is performed based on the command of the turning command switch becomes an appropriate turning force arbitrarily changed and set by the operator by the target turning force setting means. Therefore, it is possible to provide a turning control device for a work vehicle that can perform turning operation with an appropriate turning force without causing disadvantages such as feeling that the vehicle is too strong or insufficient.
[0018]
Claim 3 The work vehicle turning control device described is ,in front The target turning force setting means is provided in the grip part for operation in the turning command means so that it can be operated by a finger that has gripped and operated the grip part.
[0019]
That is, since the target turning force setting means is provided so as to be operable with a finger that is operated by gripping the grip portion in the same manner as the turning command switch, in order to operate the target turning force setting means, The change setting operation can be easily performed without removing the hand from the grip, and there is no troublesome operation. Na The
[0020]
Claim 3 The turning control device for a work vehicle according to claim 1 is provided. Or 2 And the pair of continuously variable transmissions for each steplessly changing the respective traveling speeds of the pair of left and right traveling devices, and the pair of each of the pair of continuously variable transmissions for performing a shifting operation individually. And a control means for controlling the operation of the actuator, and the control means is configured to control the pair of actuators.
[0021]
That is, by individually shifting the pair of continuously variable transmissions by the pair of actuators, the traveling speeds of the pair of left and right traveling apparatuses can be varied steplessly. Therefore, it is possible to change the turning force steplessly by changing the speed difference between the respective traveling speeds of the pair of left and right traveling devices steplessly, and the configuration in which the turning force is switched stepwise. In comparison, the turning operation can be performed as smoothly as possible, and the target turning force can be changed steplessly, so the turning operation can be performed with the most appropriate turning force that matches the operation feeling of the operator. Is possible, and claim 1 Or 2 A suitable means for carrying out is obtained.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
[First Embodiment]
Hereinafter, the case where the 1st embodiment of the turning control device of the work vehicle concerning the present invention is applied to the combine as an example of the work vehicle is described based on a drawing.
[0023]
FIG. 1 shows an entire side surface of a combine that is an example of a work vehicle. The combine is a front portion of a traveling machine body 2 that is driven by a pair of left and right crawler type traveling devices 1R and 1L that is an example of a traveling device. The chopping and conveying device 3 that cuts and conveys the planted cereal husk is connected so as to be able to move up and down, and the traveling machine body 2 receives the chopped cereal from the chopping and conveying device 3 and performs threshing and sorting processing. The apparatus 4 and the grain tank 5 that stores the grain from the threshing apparatus 4 are mounted, and the boarding operation unit 6 is formed at a location in front of the grain tank 5.
[0024]
As shown in FIG. 2, this combine transmits power from the engine 7 to the input shaft 10 of the transmission case 9 via the belt tension type main clutch 8, and a pair of traveling static electricity is transmitted from the input shaft 10. It distributes and transmits to the hydraulic continuously variable transmissions 11R and 11L (an example of a continuously variable transmission), and the power after shifting by one of the hydrostatic continuously variable transmissions 11L for traveling is transmitted to the left gear-type subtransmission 13L. To the left crawler type traveling device 1L, and the power after shifting by the other hydrostatic continuously variable transmission 11R for traveling is transferred to the right crawler type traveling device via the right gear type subtransmission 13R. A transmission mechanism for driving driving is configured to transmit to 1R. On the other hand, the power from the engine 7 is also supplied to the working hydrostatic continuously variable transmission 12, and the power after shifting by the working hydrostatic continuously variable transmission 12 is used as the belt tension type mowing clutch 14. The transmission mechanism for the cutting operation is configured so as to be transmitted to the cutting and conveying device 3 via the.
[0025]
The left and right gear-type sub-transmission devices 13R and 13L are configured as sub-transmission mechanisms that can switch the power after shifting of each of the hydrostatic continuously variable transmission devices 11R and 11L to a high and low two-stage and a power cutoff state. ing. Also, by connecting the transmission shafts 15R and 15L to each other, the left and right crawler type traveling devices 1R and 1L are integrally connected to each other, and the left and right crawler type traveling devices 1R and 1L are connected to each other. Separately, a multi-plate hydraulic clutch 16 that switches to a state in which shifting operation is allowed is provided.
[0026]
As shown in FIG. 3, a hydraulic travel operation mechanism 30 that shifts the hydrostatic continuously variable transmissions 11R and 11L for traveling separately, and a hydrostatic continuously variable transmission 12 for work. Are respectively provided with a hydraulic working operation mechanism 36 that performs a speed change operation and an electromagnetic switching valve 32 that switches a flow state of the hydraulic oil with respect to the hydraulic clutch 16. The travel operation mechanism 30 includes a pair of double-acting hydraulic cylinders 33R and 33L (an example of an actuator) coupled to the trunnion shafts 29 and 29 of the respective hydrostatic continuously variable transmissions 11R and 11L for travel. ) And a pair of two-position switching type that can be switched between a state in which hydraulic oil is supplied to a pair of oil chambers corresponding to respective operations in the forward and reverse directions for each of the hydraulic cylinders 33R and 33L and a state in which the supply is stopped. A hydraulic solenoid valve 34A for oil supply, and a pair of two-position switchable hydraulic solenoid valves 34B for switching oil that can be switched between a state of discharging hydraulic oil from the pair of oil chambers and a state of stopping discharging. Configured. Each of the hydraulic cylinders 33R and 33L is configured to be urged to return to the neutral position by the urging force of an internally mounted spring.
[0027]
Similarly, the work operation mechanism 36 is coupled to the trunnion shaft 37 in the work hydrostatic continuously variable transmission 12 and is urged to return to the neutral position by the urging force of an internal spring. A double-acting hydraulic cylinder 40 and a pair of two-position switches that can be switched between a state in which hydraulic oil is supplied to a pair of oil chambers corresponding to operations in the forward and reverse directions of the hydraulic cylinder 40 and a state in which the supply is stopped. A hydraulic solenoid valve 41A for refueling, and a pair of two-position switching hydraulic solenoid valves 41B that can be switched between a state of discharging hydraulic oil from the pair of oil chambers and a state of stopping discharging. It is configured with.
[0028]
Each of the hydraulic solenoid valves 34A and 41A for refueling is configured to move and urge the spool to a refueling stop state by the biasing force of the spring, and move the spool against the biasing force of the spring by the electromagnetic force of the solenoid. The hydraulic oil solenoid valves 34B and 41B for draining each oil are configured to be operated and switched to a state in which hydraulic oil is supplied, and the spool is moved and urged to a discharged state by a biasing force of a spring. In this configuration, the spool is moved by the electromagnetic force of the solenoid against the urging force of the spring to switch to a state where the discharge of the hydraulic oil is stopped.
The boarding operation unit 6 is provided with a single auxiliary transmission lever 25 that can be swung in the front-rear direction. The auxiliary transmission lever 25 is linked to the gear-type auxiliary transmission devices 13R and 13L. By operating the shift lever 25, the power after shifting by each of the hydrostatic continuously variable transmissions 11R, 11L for traveling can be shifted to high and low two stages.
[0029]
The shift operation of the hydrostatic continuously variable transmissions 11R and 11L as described above will be described. For example, as shown in FIG. 4, the shift position of the trunnion shaft 29 is in a neutral region having a predetermined width including the neutral position N. If there is, the shift output (travel speed) becomes zero, and when the shift position of the trunnion shaft 29 is rotated in a predetermined direction from its neutral range, the travel speed in the forward direction is increased steplessly, and the trunnion shaft 29 When the vehicle is rotated from the neutral region in the direction opposite to the predetermined direction, the traveling speed in the backward direction is increased steplessly.
[0030]
The boarding operation unit 6 includes a main transmission lever 24 that can be swung over a predetermined front-rear operation range along the front-rear direction, and a turn command means that can be swung over a predetermined left-right operation range along the left-right direction. The swivel lever 26 is provided. As shown in FIG. 3, a shift lever sensor 27 for detecting the operation position of the main shift lever 24 and a swing lever sensor 28 for detecting the operation position of the swing lever 26 are provided, both of which are rotary. It consists of a potentiometer.
[0031]
Further, the pair of hydrostatic continuously variable transmissions 11R and 11L includes rotational speed sensors 44 and 45 as shift output detecting means for detecting their output rotational speeds, and respective hydrostatic continuously variable transmissions. Shift position sensors 46 and 47 as shift position detecting means for detecting the shift positions of 11R and 11L, that is, the operation angles of the respective trunnion shafts 29 by the pair of hydraulic cylinders 33R and 33L are provided.
[0032]
A control device 31 using a microcomputer is provided as a control means for controlling the operation of the hydraulic cylinders 33R, 33L, 40. The control device 31 includes information detected by the shift lever sensor 27 and the turning lever sensor 28. Based on the above, the respective target rotational speeds of the pair of hydrostatic continuously variable transmissions 11R and 11L are obtained, and the target transmission position of each trunnion shaft 29 corresponding to the obtained target rotational speed is set, and It is configured to execute travel control for controlling the operation of the pair of hydraulic cylinders 33R, 33L so that the detection values of the respective shift position sensors 46, 47 become the respective target shift positions.
[0033]
That is, the main speed change lever 24 is operated to the neutral position (corresponding to the stop command position) located substantially in the middle of the operable range in a state where the turning lever 26 is operated to the straight travel command position and the straight travel is commanded. When the vehicle is stopped and the swinging operation is performed from the neutral position to the forward side, the traveling speed to the forward side is increased steplessly, and when operated from the neutral position to the reverse side, the reverse side is The operation of the pair of hydraulic cylinders 33R and 33L is controlled so that the traveling speed to the vehicle is steplessly increased. When the main transmission lever 24 is fixed at a predetermined position, The operation of the pair of hydraulic cylinders 33R and 33L is controlled so that the vehicle body travels straight at the commanded target travel speed.
Further, when the main shift lever 24 is operated and the controller 31 is traveling at a predetermined speed, the control device 31 swings from the rectilinear command position to either the left or right turn command operation area. The turning radius becomes smaller as the operation is further away from the rectilinear command position. In other words, the operation of each of the traveling hydraulic cylinders 33R and 33L is controlled so as to command a turning state with a large turning force. ing.
[0034]
Then, in a state where the turning force when the turning lever 26 is operated to the maximum operation position where the movement amount is the largest in the turning command operation region is changed, the operation position of the turning lever 26 in the turning command operation region. And an artificially operated turning force change setting means 42 which can freely change and set the relationship between the turning state and the target turning state.
[0035]
The turning force change setting means 42 divides the entire adjustable range for changing the turning force when the turning lever 26 is operated to the maximum operation position into a plurality of regions, and sets the plurality of divided regions. An area selection means that can be selected and operated in a setting state corresponding to any one of them, and a change and adjustment of the turning force when operated to the maximum operation position in the area selected by the area selection means And a flexible change adjusting means.
[0036]
In addition, FIG. 6 shows the degree of deceleration of the crawler traveling device on the turning side relative to the operation position of the turning lever 26, in other words, the change in the magnitude of the turning force due to the speed difference between the left and right crawler traveling devices. As shown in this figure, the changeable and adjustable range for changing the turning force when the turning lever 26 is operated to the maximum operating position is indicated by the line 5 from the speed difference zero state shown by the line L1 in FIG. The maximum speed difference setting state can be changed and adjusted, and such characteristics are set in advance and written and stored in a memory (not shown).
Then, the entire range that can be changed and adjusted is divided into three regions A, B, and C, and a three-contact type as the region selecting means for switching to one of the three regions A, B, and C. A region selection switch 42a is provided, and a switching command by the region selection switch 42a is given to the control device 31, and the control device 31 is configured to switch the region based on the switching command and execute control. Yes.
[0037]
Line L1 in FIG. 6 shows a straight traveling state in which the traveling speeds of the left and right crawler traveling devices are the same even when the turning lever 26 is operated. In the maximum speed difference setting state shown by the line 5, the turning lever 26 is moved to the maximum. When the operation position is operated, the crawler traveling device on the turning side is driven in the direction opposite to the driving rotation direction of the crawler traveling device on the opposite side at a speed substantially equal to the traveling speed of the crawler traveling device on the turning side, In this state, the pair of crawler traveling devices are rotationally driven in the opposite directions at the same speed, and the vehicle body performs a spin turn.
In the state indicated by the line L2 in the figure, when the turning lever 26 is operated to the maximum operating position, the traveling speed of the crawler traveling device on the turning side is approximately 1 / of the traveling speed V of the crawler traveling device on the opposite side. The speed is reduced to 3 speed. In the state shown in the line L3, when the turning lever 26 is operated to the maximum operating position, the speed is reduced until the running speed of the crawler running device on the turning side becomes zero. In the state shown in the line L4, the turning lever 26 is at the maximum. When operated to the operation position, the traveling speed of the crawler traveling device on the turning side is the direction opposite to the driving rotational direction of the crawler traveling device on the opposite side, and is about 1/3 of the speed of the crawler traveling device on the opposite side. Become speed.
[0038]
Further, the control panel is provided with an adjustment operation tool 42b composed of a potentiometer as the change adjusting means, and this adjustment is performed in any of the above-described respective turning modes. By adjusting the operation tool 42b, the turning force when operated to the maximum operation position in the region selected by the region selection switch 42a can be changed and adjusted. That is, when the adjustment operation tool 42b is operated to the side with the smallest turning force in a state where the region A is selected by the region selection switch 42a, the left and right traveling devices corresponding to the operation position of the turning lever 26 and the target turning force. 6 is set to the line L1 in FIG. 6, and is set to the line L2 in FIG. 6 when the turning force adjusting operation tool 42b is operated to the maximum turning force side. When the turning force adjusting operation tool 42b is operated to an intermediate position thereof, the change characteristic is changed and adjusted steplessly between the line L1 and the line L2 according to the operation amount. Note that the change characteristic is such that the change in the speed difference with respect to the change in the operation position of the turning lever 26 changes almost linearly.
Similarly, even if the areas B and C are selected by the area selection switch 42a, the change characteristics are changed and adjusted steplessly in the area in accordance with the operation amount of the adjustment operation tool 42b.
[0039]
Therefore, the relationship between the operation position in the turning command operation area of the turning lever 26 and the target turning force by the selection operation of the area selection switch 42a and the operation of the adjusting operation tool 42b, that is, left and right by the operation of the turning lever 26. One line is specified as the characteristic of the speed ratio of the crawler traveling apparatus.
[0040]
On the other hand, as shown in FIG. 5, the characteristic of the change in the target vehicle speed with respect to the operation position of the main transmission lever 24 is preset and stored, and the control device 31 controls the left and right by the operation of the turning lever 26 as described above. The hydrostatic continuously variable for the pair of left and right crawler travel devices 1R, 1L based on the characteristics of the speed ratio of the crawler travel devices 1R, 1L and the target vehicle speed determined by the operation position of the main transmission lever 24 shown in FIG. Processing for obtaining the respective target rotation speeds of the transmissions 11R and 11L is executed.
Then, as shown in FIG. 7, it corresponds to the target rotational speed obtained as described above based on the reference information set for obtaining the target shift position of the trunnion shafts 29 and 29 corresponding to each target rotational speed. Thus, the target shift positions of the trunnion shafts 29 and 29 are set so that the shift positions of the pair of trunnion shafts 29 and 29 detected by the shift position sensors 46 and 47 become the respective target shift positions. The corresponding hydraulic cylinders 33R and 33L are controlled. That is, control is performed so that the speed difference between the traveling speeds of the pair of left and right hydrostatic continuously variable transmissions 11R and 11L is different so as to achieve a target turning force.
[0041]
Hereinafter, based on a control flowchart, the control operation of the travel control by the control device 31 will be specifically described.
That is, as shown in FIG. 8, the control device 31 detects the operation position of the main transmission lever 24 detected by the transmission lever sensor 27 and the operation position of the turning lever 26 detected by the turning lever sensor 28. Based on the results, the target rotational speeds of the pair of left and right hydrostatic continuously variable transmissions 11R and 11L are obtained (steps 1 and 2). Then, the respective target shift positions for the pair of trunnion shafts 29 and 29 are set in correspondence with the obtained respective target rotational speeds (step 3).
Next, the operation of the hydraulic solenoid valves 34A and 34B is controlled so that the shift positions of the trunnion shafts 29 and 29 detected by the shift position sensors 46 and 47 become the target shift positions. A shift operation for operating the hydraulic cylinders 33R, 33L is executed (step 4). That is, feedback control based on the shift position detection information is executed.
In this manner, the traveling speed of each of the pair of left and right hydrostatic continuously variable transmissions 11R and 11L is set to a speed corresponding to the command state at that time so that the target turning force is obtained in the turning operation state. In addition, the control is performed such that the difference in traveling speed between the pair of left and right hydrostatic continuously variable transmissions 11R and 11L is different.
[0042]
The pair of left and right hydrostatic continuously variable transmissions 11R and 11L, the pair of hydraulic cylinders 33R and 33L, the travel operation mechanism 30, and the control device 31 constitute a turning operation means.
[0043]
With such a configuration, the turning state in the state where the turning lever 26 is operated to the maximum operation position can be changed and adjusted to a turning force that can be easily operated by the operator. The operation at the time of operation can be made easy.
[0044]
[Second Embodiment]
Hereinafter, 2nd Embodiment of the turning control apparatus of the working vehicle which concerns on this invention is described based on drawing.
In this embodiment, as a means for instructing a turning operation, a finger operation type turning command switch 50 is provided separately from the turning lever 26, and a control device 31 will be described later based on a command of the turning command switch 50. Except for the point that the turning control operation is performed, the other configuration is the same as that of the first embodiment. Therefore, only the different configuration will be described, and the description of the same configuration will be omitted.
[0045]
That is, in this embodiment, a turning command switch 50 that can be operated by a finger that has operated the grip portion 26a and commands a turning operation by the finger operation is provided on the grip portion 26a for operation of the turning lever 26. ing. As shown in FIGS. 9 and 10, the turn command switch 50 includes a right turn switch 50R for instructing a right turn and a left turn switch 50L for instructing a left turn. Is provided to the control device 31. Then, when the turning command switch 50 is instructed to turn when the turning lever 26 is in the rectilinear command position, the control device 31 causes the left and right of the left and right so as to obtain a preset target turning force. The crawler traveling devices 1R and 1L are configured to be controlled so as to vary the speed difference between the traveling speeds. When the turning lever 26 is swung to the turning command operation area and the turning state is commanded, the turning state by the operation of the turning lever 26 has priority, and the turning command switch 50 is operated. No operation is performed based on the command.
[0046]
Then, based on the command of the turning command switch 50, there is provided a turning force adjuster 51 comprising a potentiometer as an artificially operated target turning force setting means capable of changing and setting the target turning force when the turning operation is performed. Is provided. The turning force adjuster 51 is provided on the operating grip 26a of the turning lever 26 so that it can be operated by a finger that has gripped the grip 26a.
[0047]
As shown in FIG. 11, as the operation amount of the turning force adjusting tool 51 increases from the reference operation state (state in which the operation amount is zero), the left and right corresponding to the target turning force when performing the turning operation is increased. The change characteristics of the speed difference between the crawler travel devices 1R and 1L are preset and stored in a memory (not shown), and the control device 31 commands the turning operation by pressing the turning command switch 50. Then, while the turning command switch 50 is being pressed, the crawler traveling device on the turning side is in a low speed so as to turn the vehicle body in the commanded direction, and the left and right crawler traveling devices The hydraulic cylinders 33R, 33 for traveling so that the speed difference between the traveling speeds of 1R, 1L is the speed difference obtained from the operation position of the turning force adjuster 51 and the change characteristics. It is configured to control the operation. The configuration of the turning operation means such as the control configuration for the hydraulic cylinders 33R and 33L is the same as that of the first embodiment.
[0048]
That is, while the turn command switch 50 is being pressed, the left and right crawler travel devices 1R, 1L are driven with the speed difference changed and set by the turning force adjuster 51, and turn with the turning force corresponding to the speed difference. The operation will be performed. When the pushing operation of the turning command switch 50 is released, the turning operation is finished and the state is switched to a state where the vehicle travels straight at the vehicle speed set by the main transmission lever 24.
[0049]
Therefore, in this embodiment, by operating the turning force adjuster 51, the turning force in the turning operation according to the command of the turning command switch 50 can be changed and adjusted steplessly, and when the cutting operation is performed. When the traveling direction is finely adjusted so as to follow the crop row, the operator can make a turn in an easy-to-operate state, and the operation feeling can be improved.
[0050]
[Another embodiment]
Hereinafter, other embodiments are listed.
[0051]
(1) In the first embodiment, a pair of crawler travel devices from a state where the speed difference is zero is used as the entire range in which the turning force when the turning lever 26 is operated to the maximum operation position can be changed. Illustrated is a configuration that is rotationally driven in the opposite directions at the same speed and is configured to be adjustable to the maximum speed difference state in which the vehicle body performs a spin turn, but is not limited to such a configuration. When the turning lever 26 is operated to the maximum operating position, the crawler traveling device on the turning side is set to a state where it is driven at a speed of about 1/3 in the opposite direction to the speed of the crawler traveling device on the opposite side. The crawler travel device on the turning side can be set to a state where the speed is zero when the turning lever 26 is operated to the maximum operation position.
[0052]
(2) In the first embodiment, the turning force change setting unit is exemplified to include the region selection switch 42a as the region selection unit and the adjustment operation tool 42b as the change adjustment unit. , That Such a change adjusting means is not limited to a stepless change of the turning force when operated to the maximum operation position, and may be configured to switch in a stepwise manner to a plurality of steps.
[0053]
(3) In the first embodiment, the swing operation type swing lever is exemplified as the swing command means. However, the present invention is not limited to such a configuration, and a steering handle that can be rotated is also possible. Further, the rectilinear command position of the turning command means may have a predetermined dead band in the moving direction.
[0054]
(4) In the first embodiment, the adjustment operation tool 42b as the change adjustment means is provided on the control unit panel. For example, the gripping part of the turning lever is operated by a finger that is operated by gripping the gripping part. It may be provided so as to be operable.
[0056]
(6) In the second embodiment, the turning operation is performed with the set turning force while the turning command switch 50 is being pressed. However, the turning command switch 50 is not limited to such a configuration. For example, an operation in which a turning operation with a set turning force and a state in which the turning operation is stopped and brought into a straight running state are intermittently repeated every set short time while the button is pressed. It can be implemented in various operation modes such as a configuration or an operation mode in which a turning operation is performed with a turning force set for a set short time each time the turning command switch 50 is pushed. .
[0057]
(7) In each of the above-described embodiments, as the turning operation means, a hydrostatic continuously variable transmission that shifts the respective traveling speeds of the pair of left and right traveling devices in a stepless manner, and a pair that performs a shifting operation in each of them. In the following, the hydraulic cylinder as an actuator and the control means for controlling the operation of the hydraulic cylinder are exemplified. Instead of such a configuration, the following (a) to (d) are described. Such a configuration may be used.
(A) Instead of the hydrostatic continuously variable transmission as the pair of continuously variable transmissions, for example, a belt-type continuously variable transmission or a tapered cone type continuously variable transmission, and for switching the traveling direction back and forth It is good also as a structure provided with the forward / reverse switching mechanism etc.
(B) Instead of the hydraulic cylinder, another actuator such as an electric motor or a hydraulic motor may be used as the actuator.
(C) Instead of the actuator and the control means, instead of operating the turning lever as the turning command means, the speed change target bodies of the pair of continuously variable transmission devices are integrated in a state where a speed difference is provided. As a configuration having a link mechanism that is operated in conjunction with each other, by changing a mechanical link ratio or the like in the link mechanism, the correlation between the operation position of the turning lever in the turning command operation area and the target turning force It is good also as a structure which changes and sets a relationship.
(D) Instead of providing the continuously variable transmission as described above, the clutches interposed in the transmission system for the respective crawler traveling devices are electrically turned on and off in a short time by so-called pulse width modulation control. It is good also as a structure which changes and adjusts the speed difference of a crawler traveling apparatus.
In short, the turning operation means may be configured so that the turning force can be changed by changing the traveling speed of each of the pair of traveling devices.
[0058]
(8) In the above embodiment, the combine is exemplified as the work vehicle. However, the present invention is not limited to the combine, and may be another agricultural work vehicle such as a carrot harvester or a radish harvester. Other work vehicles may be used.
[Brief description of the drawings]
FIG. 1 is an overall side view of a combine.
FIG. 2 is a schematic configuration diagram showing a transmission structure.
FIG. 3 is a control block diagram.
FIG. 4 is a diagram showing a relationship between a shift position and a shift output.
FIG. 5 is a diagram showing a relationship between a main shift lever operation position and a target vehicle speed.
FIG. 6 is a diagram showing the relationship between the operation position of the turning lever and the speed ratio of the left and right traveling devices.
FIG. 7 is a diagram showing a relationship between a target rotation speed and a target shift position.
FIG. 8 is a flowchart of the control operation.
FIG. 9 is a control block diagram of the second embodiment.
FIG. 10 is a view showing a turning command switch of the second embodiment.
FIG. 11 is a diagram illustrating a relationship between an adjustment tool operation amount and a left-right speed difference according to the second embodiment.
[Explanation of symbols]
1R, 1L traveling device
11R, 11L continuously variable transmission
26 Turning command means
26a grip part
31 Control means
33R, 33L Actuator
42 Turning force change setting means
42a Area selection means
42b Change adjustment means
50 Turn command switch
51 Target turning force setting means

Claims

The traveling state of the pair of left and right traveling devices can be switched between a straight traveling state and a turning state, and in the turning state, the traveling speed of the traveling device on the turning side of the pair of traveling devices is varied and the traveling on the opposite side is performed. A turning operation means configured to freely change the turning force in a form in which the traveling speed of the device is the same as the straight traveling state ;
It can be moved over the entire range of the rectilinear command position that commands the straight travel state and the swivel command operation region that commands the swivel state, and the amount of movement in the direction away from the straight travel command position is large in the swivel command operation region A turn control device for a work vehicle comprising a turn command means for commanding a turning state with a large turning force,
Within the turning command operation area of the turning command means in a state where the turning force is increased or decreased when the turning command means is operated to the maximum operation position where the movement amount is the largest in the turning command operation area. An artificially operated turning force change setting means that can freely change and set the correlation between the operation position and the target turning force is provided,
The turning operation means is
Based on the command information of the turning command means and the setting information of the turning force change setting means, the operation position of the turning command means within the turning command operation area and the turning force change setting means are set. The pair of travel devices are configured to vary the speed difference between the travel speeds so that the target turning force obtained by the correlation is obtained ,
The turning force change setting means is
The changeable and adjustable range for increasing or decreasing the turning force when the turning command means is operated to the maximum operating position is divided into a plurality of areas, and the area is set to any one of the divided areas. Area selection means that can be selected and operated in a corresponding setting state
A turning control device for a work vehicle, comprising: a change adjusting means capable of changing and adjusting the turning force when operated to the maximum operating position in an area selected by the area selecting means .

The traveling state of the pair of left and right traveling devices can be switched between a straight traveling state and a turning state, and in the turning state, the traveling speed of the traveling device on the turning side of the pair of traveling devices is varied and the traveling on the opposite side is performed. A turning operation means configured to freely change the turning force in a form in which the traveling speed of the device is the same as the straight traveling state;
It can be moved over the entire range of the rectilinear command position that commands the straight travel state and the swivel command operation region that commands the swivel state, and the amount of movement in the direction away from the straight travel command position is large in the swivel command operation region A turn control device for a work vehicle comprising a turn command means for commanding a turning state with a large turning force,
A swivel command switch that is provided in the grip portion for operation in the swivel command means so as to be operable with a finger that has gripped the grip portion and commands a swivel operation by a finger operation;
Based on the command of the turning command switch, there is provided an artificially operated target turning force setting means capable of changing and setting a target turning force when performing a turning operation,
The turning operation means is
Based on the command of the turning command switch, the speed difference between the traveling speeds of the pair of traveling devices is made different so as to turn with the target turning force set by the target turning force setting means. Composed of
The target turning force setting means, wherein the grip portion for operating the turning command means, operably disposed et al which do that work vehicle turning control device in the operated finger grip the grip portion.

The turning operation means is
A pair of continuously variable transmissions that steplessly change the respective traveling speeds of the pair of left and right traveling devices, a pair of actuators that respectively shift the pair of continuously variable transmissions individually, and operations of the actuators And a control means for controlling
The turning control device for a work vehicle according to claim 1 or 2 , wherein the control means is configured to control the pair of actuators .