JP4753337B2

JP4753337B2 - Work vehicle

Info

Publication number: JP4753337B2
Application number: JP2001277715A
Authority: JP
Inventors: 智史前川; 秀樹松岡
Original assignee: Yanmar Co Ltd
Current assignee: Yanmar Co Ltd
Priority date: 2001-09-13
Filing date: 2001-09-13
Publication date: 2011-08-24
Anticipated expiration: 2021-09-13
Also published as: JP2003080961A

Description

【０００１】
【発明の属する技術分野】
本発明は例えば苗載台及び苗植付爪を備えて連続的に苗植作業を行う田植機またはトラクタまたはコンバインまたは土木建機などの作業車に関する。
【０００２】
【発明が解決しようとする課題】
従来、ギヤミッションでは高い動力伝達効率となるが、有段変速により操作性を向上し得ない不具合がある。また、油圧式無段変速機構は初速がゼロから発進させるゼロ発進可能な無段変速により優れた操作性を得られるが、動力伝達効率に限界があり、低速での動力損失が大きくなる不具合がある。また、Ｖベルト及びプーリを用いたベルト式無段変速機構は高効率の無段変速を行えるが、初速がゼロから発進させるゼロ発進を行えない不具合がある。そこで田植機など作業車においては、湿田（泥土路面）での走破性、スムーズな圃場の出入、ショックの少ない変速動作、クラッチが不要な発進動作、作業または田面などの状況に適応した速度調節などが要求され、高い動力伝達効率、及びゼロ発進可能な無段変速、及び簡単な変速操作が望まれるもので、そのため油圧変速機構に遊星ギヤ機構を組合せて油圧変速機構単体使用での動力損失など無くして、油圧を用いた場合の操作性をギヤ（機構）を用いた場合の高い伝達効率を両立させた手段があるが、油圧変速機構の出力を遊星ギヤ機構、変速ギヤ機構、デフ機構を介し前輪に伝達させる構造にあって、これら各機能の機構やギヤをミッションケース内に一体に組込む場合、ミッションケース内の構造が複雑化し機構やギヤの組立てが行い難いばかりでなく、ミッションケースも大型化し、またデフ機構を組込むデフケースとミッションケースとを別形成した場合には部品点数や、組立工数の多い極めて不経済なものとなる不具合があった。さらに、前記油圧変速機構の性能の安定保持を図る為には、前記油圧変速機構に油圧を供給するチャージポンプが前記ミッションケースから油を良好に吸い出せることが要求される。
【０００３】
【課題を解決するための手段】
然るに、本発明は、油圧変速機構の変速出力をミッションケース内で遊星ギヤ機構、変速ギヤ機構、デフ機構を介し車輪に伝達して車輪の駆動を行う作業車において、前記油圧変速機構はポンプ軸及びモータ軸が前記ミッションケースの内部に突入された状態で前記ミッションケースに固定されており、前記遊星ギヤ機構は前記ポンプ軸を介してエンジンからの動力を入力し且つ前記モータ軸を介して前記油圧変速機構からの動力を入力する状態で前記ミッションケースの遊星ギヤ室に収容され、前記変速ギヤ機構は仕切壁を介して前記遊星ギヤ室から区画された変速ギヤ室に収容され、前記デフ機構は仕切壁を介して前記変速ギヤ室及び前記遊星ギヤ室から区画されたデフ機構室に収容されており、前記ミッションケースに設けられた油圧戻り口を介して前記遊星ギヤ室に流入される前記油圧変速機構からの油が前記変速ギヤ室を経由して前記デフ機構室に流入するように、前記遊星ギヤ室及び前記変速ギヤ室を仕切る前記仕切壁並びに前記変速ギヤ室及び前記デフ機構室を仕切る前記仕切壁にはそれぞれ流通口が設けられ、前記デフ機構室に固定されたフロントアクスルケースに設けられた油出口を介して前記デフ機構室に流入された油がチャージポンプによって吸引されるものであり、前記油圧戻り口から前記油出口を遠く離して、油の泡立ちを有効に防止して、前記チャージポンプによる良好な油の吸出などを容易に可能とさせて、前記油圧変速機構の性能の安定保持を図るものである。
【０００４】
例えば、前記チャージポンプは、前記ポンプ軸と同軸上に配置され且つ前記ポンプ軸に連結された駆動軸によって駆動される。
【０００５】
【発明の実施の形態】
以下、本発明の実施例を図面に基づいて詳述する。図１は全体の側面図、図２は同平面図、図３は車体フレームの側面図、図４は同平面図を示し、図中１は作業者が搭乗する走行車であり、エンジン２を車体フレーム３に搭載させ、ミッションケース４側方にフロントアクスルケース５を介して水田走行用前輪６を支持させると共に、前記ミッションケース４後方のリヤアクスルケース７に水田走行用後輪８を支持させる。そして前記エンジン２等を覆うボンネット９両側に予備苗載台１０を取付けると共に、作業者が搭乗する車体カバー１１によって前記ミッションケース４等を覆い、前記車体カバー１１後側上方にシートフレーム１２を介して運転席１３を取付け、その運転席１３の前方で前記ボンネット９後部に操向ハンドル１４を設ける。
【０００６】
また、図中１５は５条植え用の苗載台１６並びに複数の苗植付爪１７などを具備する植付部であり、前高後低の合成樹脂製の前傾式苗載台１６を下部レール１８及びガイドレール１９を介して植付ケース２０に左右往復摺動自在に支持させると共に、一方向に等速回転させるロータリケース２１を前記植付ケース２０に支持させ、該ケース２１の回転軸芯を中心に対称位置に一対の爪ケース２２・２２を配設し、その爪ケース２２・２２先端に苗植付爪１７・１７を取付ける。
【０００７】
また、前記植付ケース２０前側のヒッチブラケット２３をトップリンク２４及びロワーリンク２５を含む昇降リンク機構２６を介し走行車１後側に連結させ、前記リンク機構２６を介して植付部１５を昇降させる油圧昇降シリンダ２７をロワーリンク２５に連結させ、前記前後輪６・８を走行駆動して移動すると同時に、左右に往復摺動させる苗載台１６から一株分の苗を植付爪１７によって取出し、連続的に苗を植える田植作業を行うように構成する。
【０００８】
また、図中２８は主変速レバー、２９は植付部１５の昇降・植付クラッチの入切・マーカ操作を行う植付操作レバー、３０はブレーキペダル、３１は変速ペダル、３２はデフロックペダル、３３は感度調節レバー、３４は植付部１５を任意高さ位置に停止させるストップレバー、３５はユニットクラッチレバー３５であり、操向ハンドル１４位置近傍に変速及び昇降レバー２８・２９やブレーキ及び変速ペダル３０・３１を配設すると共に、運転席１３位置近傍に感度調節及びストップ及びユニットクラッチの各レバー３３・３４・３５やデフロックペダル３２を配設している。
【０００９】
さらに、図中３６は１条分均平用センタフロート、３７は２条分均平用サイドフロート、３８は肥料ホッパ３９内の肥料を送風機４０の送風力でフレキシブル形搬送ホース４１を介しフロート３６・３７の側条作溝器４２に排出させる５条用側条施肥機である。
【００１０】
図３乃至図５に示す如く、前記車体フレーム３は前部フレーム４３と中間フレーム４４と後部フレーム４５とに３分割させ、左右一対の前部フレーム４３にエンジン２を、左右一対の中間フレーム４４にフロントアクスルケース５を、左右一対の後部フレーム４５にリヤアクスルケース７及びエンジン２に燃料を供給する燃料タンク４６などを設けるもので、前部フレーム４３の前側と中間に前フレーム４７とベースフレーム４８を連結させて平面視４角枠状に形成し、固定ブラケット４９とベースフレーム４８に防振ゴムを介しエンジン２を上載させる。
【００１１】
また図１０にも示す如く、前記後部フレーム４５の中間立上り部５０間をパイプフレーム５１と門形フレーム５２とで略平行に連結させると共に、リヤアクスルケース７に左右下端を固設する門形フレーム５３の後端を一体連結させ、前記の左右の立上り部５０間に燃料タンク４６を配設する。
【００１２】
さらに、前部フレーム４３後端と後部フレーム４５前端に左右中間フレーム４４の前後端をボルト５４を介して取外し自在に固定させると共に、左右中間フレーム４４の下面にボルト５５を介して左右フロントアクスルケース５を取外し自在に固定させ、前記ミッションケース４に左右フロントアクスルケース５を接続固定させる。
【００１３】
図６乃至図９に示す如く、前記ミッションケース４の前面左側にパワーステアリングケース５６を設け、かつケース４の右側に無段油圧変速機構５７を設け、油圧変速機構５７の変速入力用ポンプ軸５８を車体前方向に突出させ、エンジン２下側で前後方向の伝達軸５９にポンプ軸５８を連結させると共に、エンジン２の出力軸６０に伝達ベルト６１を介して前記伝達軸５９を連結させ、エンジン２出力を油圧変速機構５７に伝達する。
【００１４】
また、前記ミッションケース４とリヤアクスルケース７を車体の前後方向の中心ライン上でパイプ製の連結フレーム６２によって一体連結させ、ミッションケース４後方にリヤ出力軸６３及びＰＴＯ出力軸６４を突出させ、リヤアクスルケース７前方に突出させるリヤ入力軸６５にリヤ伝達軸６６を介し前記リヤ出力軸６３を連結させ、走行出力軸６３から左右の後輪８に動力を伝える。またリヤアクスルケース７上部の軸受６７に設ける中介軸６８に自在継手軸６９を介して前記ＰＴＯ出力軸６４を連結させ、前記植付ケース２０の入力軸に自在継手軸を介して中介軸６８を連結させ、ＰＴＯ出力軸６４から植付部１５に動力を伝える。
【００１５】
さらに、図１１乃至図２０に示す如く、前記ミッションケース４は、本体胴部７０と、前蓋部７１と、後蓋部７２を備え、前記胴部７０の前後に各蓋部７２を着脱自在にボルト固定させ、密閉箱形に形成すると共に、前記胴部７０の内部を前後に分割する仕切り壁部７３を設ける。また、前蓋部７１前面に前記油圧変速機構５７を取付け、ミッションケース４内に突出させるポンプ軸５８に小径の伝達ギヤ７４を係合軸支させ、伝達ギヤ７４を前蓋部７１にベアリング軸受し、後蓋部７２後面に固定させるチャージポンプ７５に伝達ギヤ７４の動力をパイプ軸７６を介して伝える。
【００１６】
また、前記ミッションケース４内に突出させる油圧変速機構５７のモータ軸７７にサンギヤ７８を係合軸支させ、サンギヤ７８を前蓋部７１にベアリング軸受すると共に、前記の小径の伝達ギヤ７４に大径のキャリヤギヤ７９を常に噛合させ、サンギヤ７８のボス部にキャリヤギヤ７９を遊転軸支させるもので、キャリヤギヤ７９に３枚のプラネタリギヤ８０を軸８１を介して回転自在に設け、サンギヤ７８にプラネタリギヤ８０を噛合させると共に、プラネタリギヤ８０に噛合させるリングギヤ８２を設け、各ギヤ７８・８０・８２によって遊星ギヤ機構８３を形成する。
【００１７】
また、前記サンギヤ７８と後蓋部７２に合成出力軸８４の前後を回転自在に軸支させ、前記リングギヤ８２を合成出力軸８４に係合軸支させるもので、油圧変速機構５７の油圧ポンプ８５及び油圧モータ８６の無段油圧変速出力である正逆回転出力と、伝達ギヤ７４及びキャリヤギヤ７９の減速回転出力（一方向の一定回転）とを、遊星ギヤ機構８３のデフ作用によって合成し、ゼロ乃至最大速の一方向の回転力として合成出力軸８４に伝える。
【００１８】
さらに、前記合成出力軸８４に前進ギヤ８７と後進ギヤ８８を遊転軸支させ、合成出力軸８４に各ギヤ８７・８８をスライダ８９によって選択的に係合させ、前進または中立または後進の出力に切換えると共に、仕切り壁部７３と後蓋部７２に前記リヤ出力軸６３をベアリング軸受する。また、差動ギヤ９０を介して左右の前車軸９１に動力を伝えるフロント出力軸９２と、ＰＴＯ変速ギヤ９３を係合軸支させるカウンタ軸９４を設け、前記のリヤ及びフロント出力軸６３・９２に出力ギヤ９５・９６を介して後進ギヤ８８の後進動力を伝え、前後輪６・８を後進駆動させると共に、リヤ出力軸６３に移動ギヤ９７及び植付ギヤ９８を遊転軸支させ、副変速スライダ９９によって各ギヤ９７・９８をリヤ出力軸６３に選択的に係合させる。
【００１９】
また、カウンタ軸９４の高速用ギヤ１００を介して前進ギヤ８７に移動ギヤ９７を常に噛合させると共に、カウンタ軸９４の低速用のＰＴＯ変速ギヤ９３に植付ギヤ９８を常に噛合させ、各ギヤ１００・９３・９８を介して前進ギヤ８７の動力を前記各出力軸６３・９２に伝え、前後輪６・８を苗の植付け作業速度で前進駆動する。また、移動ギヤ９７と植付ギヤ９８の両方が遊転状態となり、植付爪１７などを作業者が手で回転させて詰った苗の除去などを行えるように、ＰＴＯ出力軸６４の手動回転を可能にすると共に、前進ギヤ８７の動力を各ギヤ１００・９７を介して各出力軸６３・９２に伝え、圃場間の路上移動などの高速の移動速度で前後輪６・８を前進駆動する。
【００２０】
さらに、図１２のように、ＰＴＯ変速軸１０１及びＰＴＯ変速機構１０２を介してＰＴＯ変速ギヤ９３の動力をＰＴＯ出力軸６４に伝え、株間変速自在に植付部１５を駆動すると共に、ミッションケース４に内設させるチェン１０３を介してＰＴＯ出力軸６４に施肥出力軸１０４を連結させ、植付部１５と同調させて施肥機３８を駆動する。また、図１３のように、ミッションケース４にオイルゲージ１０５を設けると共に、図１４のように、前記各スライダ８９・９９を同一のシフトフォーク１０６に係止させ、変速レバー２８の５位置切換によって前後進及び副変速（低高速）の切換を行う。また、図１６乃至図１８のように、油圧ポンプ８５の斜板１０７に制御軸１０８を介して油圧変速操作アーム１０９を連結させ、該アーム１０９にロッド１１０を介して変速ペダル３１を連結させると共に、ペダル３１の足踏み解除によってペダル３１を自動的に停止（速度ゼロ）位置に復帰動作させるバネ１１１を前記アーム１０９に連結させ、また定速作動部材であるオイルダンパ１１２を前記アーム１０９に連結させ、踏み込んでいたペダル３１から足を離したとき、オイルダンパ１１２の抵抗とバネ１１１の復動力によりペダル３１が緩やかな略一定速度で戻って除々に低速になる動作を行わせる。なお、オイルダンパ１１２に代え、ガススプリングなどによって定速作動部材を形成してもよい。
【００２１】
さらに、図２０のように、前記ペダル３１から足を離している状態でバネ１１１によってペダル３１が停止（速度ゼロ）位置に戻っているとき、サンギヤ７８は最高回転で時計回りに逆転してプラネタリギヤ８０を反時計回りに自転させる動作を行わせると同時に、また伝達ギヤ７４によってキャリヤギヤ７９を回転させることにより、プラネタリギヤ８０を時計方向に公転させて反時計回りに自転させる動作を行わせ、リングギヤ８２の回転をゼロにし、合成出力軸８４を停止維持する。また、ペダル３１をバネ１１１に抗して中位置（中速域）に足で踏んだとき、サンギヤ７８は停止し、伝達ギヤ７４によってキャリヤギヤ７９を回転させ、プラネタリギヤ８０を時計方向に自転させ乍ら時計方向に公転させ、伝達ギヤ７４のギヤ動力により合成出力軸８４を回転させる。また、ペダル３１を最大に踏み込んだとき、サンギヤ７８は最高回転で反時計回りに正転し、プラネタリギヤ８０を時計方向に自転させ乍ら伝達ギヤ７４でキャリヤギヤ７９を回転させることによって時計方向に公転させ、サンギヤ７８からの油圧変速力と伝達ギヤ７４動力を加算して合成出力軸８４を回転させるもので、図２１のように、エンジン２動力を伝達ギヤ７４と油圧変速機構５７とに伝えて遊星ギヤ機構８３により合成して出力させ、ミッションケース４で前後進切換とＰＴＯ変速を行い、後進、低速前進（圃場植付走行）、高速前進（路上移動走行）の各動作を行わせる。
【００２２】
そして、例えば、図２２のように、油圧変速操作アーム１０９の角度を−１乃至０乃至１に変化させることにより、モータ軸７７が−１０００乃至０乃至１０００回転になるようにし、図２３のように、前記アーム１０９の角度に関係なくギヤ７４側を１０００回転させた場合、図２４のように、前記アーム１０９の角度に対して合成出力軸８４が０乃至２０００回転になるように、ギヤ７４・７９及び遊星ギヤ機構８３を組成する。
【００２３】
また、前記アーム１０９の全制御範囲を−１乃至０乃至１としたとき、図１９に示す如く、前記アーム１０９の低速（ゼロ速度）側及び高速側の制御動作をボルト型低速及び高速ストッパ１１３・１１４によって規制し、図２５のように、前記各ストッパ１１３・１１４によって調節自在な実際のアーム１０９の操作範囲を−０．８乃至０．６にして、０乃至１．４ｍ／Ｓの作業速度を得ることにより、油圧変速機構５７の組立誤差などによって生じる出力特性のバラツキに対して前記各ストッパ１１３・１１４により調整すると共に、例えば前記アーム１０９の−１乃至０．８の位置を調整域とし、速度をゼロにすることができ、仮りにアーム１０９が−１でも速度がゼロにならない不具合をなくしている。図２６及び図２７のように、一般的な作業速度において、油圧変速機構５７とギヤ７４側の動力分担比が６０パーセント以上にし、油圧変速機構５７の有効動力に対し、ギヤ７４側の有効動力の割合を大きくし、湿田での走破性を向上させ、湿田での作業能率を向上させ、また耕盤の段差に対して余裕の脱出能力を持たせる。
【００２４】
図１５にも示す如く、前記遊星ギヤ機構８３のキャリヤギヤ７９に噛合せて該ギヤ７９を駆動する伝達ギヤ７４の一側を、前記ポンプ軸５８のスプライン軸５８ａに取外し自在に嵌合させると共に、ギヤ７４の他側にパイプ軸７６を嵌合固定させて、油圧変速機構５７と遊星ギヤ機構８３との合成出力を形成する複合変速機構１１５を設けている。そして、油圧変速機構５７の入力軸であるポンプ軸５８及びパイプ軸７６に遊星ギヤ機構８３の駆動用ギヤである伝達ギヤ７４を設けることによって、油圧変速機構５７のポンプ軸５８とは別個に遊星ギヤ機構８３を駆動するための駆動ギヤ専用のギヤ軸を別個所に設置する構造の複雑さを解消させ、油圧変速機構５７のポンプ軸５８を利用した簡単な構成手段のもので、各駆動部に高い伝達効率の複合変速機構１１５の変速出力を有効に伝達させることができる。
【００２５】
また、油圧変速機構５７のポンプ軸５８と、該ポンプ軸５８と同一軸芯上に設ける油圧変速機構５７など油圧機構に油圧を供給するポンプ７５を駆動させるための駆動軸であるパイプ軸７６とを利用して、強度且つ安定良好に伝達ギヤ７４を支持可能とさせると共に、ポンプ７５駆動部をコンパクトに配置することも可能とさせることがきる。
【００２６】
また、油圧変速機構５７の出力軸であるモータ軸７７上に遊星ギヤ機構８３を設けるもので、サンギヤ７８の一側内面部をモータ軸７７のスプライン軸７７ａに取外し自在に嵌合させると共に、一側外面部をベアリング１１６を介し前蓋部７１に回転自在に支持させ、サンギヤ７８の他側を合成出力軸８４に軸受部材１１７を介して遊転支持させるように構成している。そして油圧変速機構５７のモータ軸７７とポンプ軸５８の延長方向に遊星ギヤ機構８３とこの駆動用ギヤ７４を設けて、油圧変速機構５７の形状を軸方向に若干延設させた大きさで複合変速機構１１５を横巾の狭い小型コンパクトなものに形成可能とさせるもので、油圧変速機構８３のモータ軸７７に遊星ギヤ機構８３を設けることによって、ミッションケース４内に小型コンパクトに遊星ギヤ機構８３を組込んで、ミッションケース４の小型軽量化を容易に可能とさせるように構成している。
【００２７】
また、前記サンギヤ７８の一側をミッションケース４の前蓋部７１に、他側を合成出力軸８４に支持させると共に、サンギヤ７８の外周面に遊転支持させるキャリヤギヤ７９と出力軸８４にスプライン８４ａ嵌合させるリングギヤ８２間にプラネタリギヤ８０を配設して、遊星ギヤ機構８３の軸方向の距離を短かして複合変速機構１１５の一層のコンパクト化を図るように構成している。
【００２８】
図６に示す如く、前車体カバー１１ａ及び後車体カバー１１ｂに分割形成する車体カバー１１の前車体カバー１１ａの下側に油圧変速機構５７を平面視でラップさせ、エンジン２やベルト６１などのメンテナンス時に前車体カバー１１ａを取外すだけで、この変速機構５７のメンテナンスも容易に可能とさせると共に、重量物の変速機構５７をミッションケース４の前側位置に配置させて、機体の前後バランスを良好とさせるように構成している。
【００２９】
図１１、図１２、図２８乃至図３０に示す如く、前記ミッションケース４は遊星ギヤ機構８３を有する遊星ギヤ室１１８と、前後進ギヤ８７・８８やＰＴＯ変速機構１０２など有する変速ギヤ室１１９と、差動ギヤ９０など有する差動ギヤ室１２０を内設するもので、各機能ごとに区画された３つのギヤ室１１８・１１９・１２０を有し、図２９に示す如く平面視で遊星ギヤ室１１８の後側及び左側に変速ギヤ室１１９及び差動ギヤ室１２０を配設させ、遊星ギヤ機構８３の左側に差動ギヤ９０を近接配置させて、ミッションケース４の前後幅を短縮させて小型化するように構成している。
【００３０】
また、前記差動ギヤ室１２０に接続固定する左フロントアクスルケース５の接続ケース１２１にサクション口１２２を設け、前記チャージポンプ７５などに油圧ホース１２３を介しサクション口１２２を連通接続させて、ミッションケース４内に貯留する作動油をチャージポンプ７５を介し油圧変速機構５７などに供給するように構成している。
【００３１】
そして、前記遊星ギヤ室１１８に設ける油圧変速機構５７の油圧戻り口１２４などより遠隔した位置にサクション口１２２を設けて、油の泡立ちなど有効に防止すると共に、遊星ギヤ室１１８と変速ギヤ室１１９及び変速ギヤ室１１９と差動ギヤ室１２０を仕切る仕切り壁部７３・１２５に油の流通口１２６・１２７を適宜開設して、遊星ギヤ室１１８内に貯留される作動油を流通口１２６・１２７を介して変速ギヤ室１１９及び差動ギヤ室１２０に順次送り込んでサクション口１２２より吸出させて、油の泡立ちを一層防止しチャージポンプ７５などに対する油圧の良好な供給を行うように構成している。
【００３２】
なお、前記接続ケース１２１のサクション口１２２とは反対側位置に差動ギヤ９０のデフロック機構１２８を入切操作するデフロックレバー１２９（前記デフロックペダル３２に図示せぬ連動機構を介して連動）を設けると共に、前記ブレーキペダル３０にブレーキレバー軸１３０及びブレーキレバー１３１を介し連結させる走行用ブレーキ１３２をフロント出力軸９２に設けている。
【００３３】
上記からも明らかなように、油圧変速機構７５の変速出力をミッションケース４内で遊星ギヤ機構８３、変速ギヤ機構である前後進ギヤ８７・８８、デフ機構である差動ギヤ９０を介し車輪である前輪６の駆動を行う作業車において、前記遊星ギヤ機構８３、前後進ギヤ８７・８８、差動ギヤ９０をミッションケース４内の区画した区画室１１８・１１９・１２０に設けることによって、各機能別のギヤ８７・８８、９０や機構８３の配置を行って、構造のシンプル化や組立ての容易化を図ると共に、剛性を保った状態でミッションケース４の肉厚も薄くしてミッションケース４の軽量化も容易に可能にできる。
【００３４】
また、ミッションケース４内に貯留させる作動油を各ギヤ機構室である遊星ギヤ室１１８、変速ギヤ室１１９、差動ギヤ室１２０を介してフロントアクスルケース５の油出口であるサクション口１２２に流通させて取出すことによって、区画された各ギヤ室１１８・１１９・１２０を順次流通させ、油の戻り口１２４からサクション口１２２を遠く離して、油の泡立ちを有効に防止して、油圧ポンプ８５による良好な油の吸出などを容易に可能とさせて、油圧変速機構５７の性能の安定保持を図ることができる。
【００３５】
図３１に示す如く、前記油圧変速機構５７の入力側に前後進・移動速の変速を行う車速変速機構１３０を設置させることも可能とさせるもので、前後進ギヤ８７・８８や移動・植付・高速ギヤ９７・９８・１００など有する車速変速機構１３０からの変速出力を複合変速機構１１５を構成する油圧ポンプ８５のポンプ軸５８に入力させ、複合変速機構１１５の合成出力軸８４からの合成出力を出力ギヤ９５・９６などを介してフロント出力軸９２及びリヤ出力軸６３に伝えて、前後輪６・８を高速前進（移動速）・低速前進（植付速）・後進させるように構成して、例えばアーム１０９が−１のときの速度の０調節を確実に行わせて、機体のゼロ発進動作の精度を容易に向上させることができる。
【００３６】
【発明の効果】
以上実施例から明らかなように本発明は、油圧変速機構５７の変速出力をミッションケース４内で遊星ギヤ機構８３、変速ギヤ機構８７・８８、デフ機構９０を介し車輪６に伝達して車輪の駆動を行う作業車において、前記遊星ギヤ機構８３、変速ギヤ機構８７・８８、デフ機構９０をミッションケース４において区画された遊星ギヤ室１１８・変速ギヤ室１１９・差動ギヤ室１２０内にそれぞれ設けたものであるから、各機能別の各機構８３、８７・８８、９０の配置を行って、構造のシンプル化や組立の容易化を図ると共に、剛性を保った状態でミッションケース４の肉厚を有効に薄くしてミッションケース４の軽量化を容易に可能とさせることができるものである。
【００３７】
さらに、前記ミッションケース４に設けられた油圧戻り口１２４を介して前記遊星ギヤ室１１８に流入される前記油圧変速機構５７からの油が前記変速ギヤ機構室１１９を経由して前記デフ機構室１２０に流入するように前記遊星ギヤ室１１８及び前記変速ギヤ室１１９を仕切る仕切壁７３に流通口１２６が、前記変速ギヤ室１１９及び前記デフ機構室１２０を仕切る仕切壁１２５に流通口１２７が設けられ、前記デフ機構室１２０に固定されたフロントアクスルケース５の油出口１２２を介して前記デフ機構室１２０に流入された油がチャージポンプ８５によって吸引されるものであるから、区画された各機構室１１８・１１９・１２０を順次流通させ、前記戻り口１２４から前記油出口１２２を遠く離して、油の泡立ちを有効に防止して、前記チャージポンプ８５による良好な油の吸出などを容易に可能とさせて、前記油圧変速機構５７の性能の安定保持を図ることができるものである。
【図面の簡単な説明】
【図１】田植機の全体側面図。
【図２】田植機の全体平面図。
【図３】走行車体の側面図。
【図４】走行車体の平面図。
【図５】車体フレームの側面図。
【図６】駆動部の側面説明図。
【図７】駆動部の平面説明図。
【図８】サイドクラッチ操作系の側面説明図。
【図９】サイドクラッチ操作系の平面説明図。
【図１０】車体の斜視説明図。
【図１１】ミッションケースの断面図。
【図１２】同拡大図。
【図１３】遊星ギヤ機構の説明図。
【図１４】ミッションケースの部分図。
【図１５】遊星ギヤ機構の断面図。
【図１６】変速ペダル部の前方からの斜視図。
【図１７】変速ペダル部の後側上方からの斜視図。
【図１８】ミッションケースのギヤ配列説明図。
【図１９】油圧変速操作アーム部の側面図。
【図２０】遊星ギヤ機構の回転説明図。
【図２１】エンジンの出力説明図。
【図２２】油圧変速機構の出力説明図。
【図２３】伝達ギヤ側の出力説明図。
【図２４】合成出力軸の出力説明図。
【図２５】変速ペダルの変速説明図。
【図２６】油圧変速出力とギヤ変速出力の相関図。
【図２７】図２６の出力と油圧損失及びギヤ損失の相関図。
【図２８】ミッションケースの平面説明図。
【図２９】ミッションケースの平面断面図。
【図３０】ミッションケースの側面断面図。
【図３１】複合変速機構の他の駆動説明図。
【符号の説明】
４ミッションケース
５フロントアクスルケース
６前輪（車輪）
５７油圧変速機構
５８ポンプ軸
７３・１２５仕切壁
７５チャージポンプ
７６パイプ軸（駆動軸）
８３遊星ギヤ機構
８７・８８ギヤ（ギヤ機構）
９０差動ギヤ（デフ機構）
１１８・１１９・１２０ギヤ室（ギヤ機構室）
１２０サクション口（油出口）
１２４油圧戻り口
１２６・１２７流通口 [0001]
BACKGROUND OF THE INVENTION
The present invention relates to a work vehicle such as a rice transplanter, a tractor, a combine, or a civil construction machine that includes a seedling stage and a seedling planting claw and continuously performs seedling planting work.
[0002]
[Problems to be solved by the invention]
Conventionally, gear transmission has high power transmission efficiency, but there is a problem that the operability cannot be improved by stepped shifting. In addition, the hydraulic continuously variable transmission mechanism has excellent operability due to the continuously variable transmission that can start from zero, with the initial speed starting from zero, but there is a limit to the power transmission efficiency and there is a problem that the power loss at low speed increases. is there. A belt type continuously variable transmission mechanism using a V-belt and a pulley can perform a highly efficient continuously variable transmission, but there is a problem that the initial speed cannot start from zero. Therefore, for work vehicles such as rice transplanters, running on wet fields (muddy roads), smooth entry and exit of the field, shifting operation with less shock, start-up operation that does not require a clutch, speed adjustment adapted to the situation such as work or rice field, etc. Therefore, high power transmission efficiency, continuously variable transmission capable of starting at zero, and simple gear shifting operation are desired. For this reason, a power loss caused by using a single hydraulic transmission mechanism by combining a planetary gear mechanism with a hydraulic transmission mechanism, etc. However, there is a means to achieve both high operability when using gears and high transmission efficiency when using gears (mechanisms), but the output of the hydraulic speed change mechanism can be changed to a planetary gear mechanism, speed change gear mechanism, and differential mechanism. If the mechanisms and gears of each function are integrated into the transmission case, the structure of the transmission case becomes complicated and the mechanism and gears are not assembled. Not only difficult to have, the transmission case also increased in size, also and the number of components in the case were separately form the differential case and the transmission case incorporating a differential mechanism, there is a problem to be the ones often extremely uneconomical of the number of assembly steps. Further, in order to stably maintain the performance of the hydraulic transmission mechanism, it is required that a charge pump that supplies hydraulic pressure to the hydraulic transmission mechanism can suck out oil from the transmission case satisfactorily.
[0003]
[Means for Solving the Problems]
However, the present invention provides a planetary gear mechanism the gear output in a transmission case of the hydraulic transmission mechanism, the speed change gear mechanism, in and transmitted to the wheels through a differential mechanism work vehicle for driving the wheels, the hydraulic transmission mechanism pump shaft And the motor shaft is fixed to the transmission case in a state of entering the inside of the transmission case, and the planetary gear mechanism inputs power from the engine through the pump shaft and the motor shaft through the motor shaft. The gearbox is accommodated in the planetary gear chamber of the transmission case in a state where power from the hydraulic transmission mechanism is input, and the gearshift gear mechanism is accommodated in a transmission gear chamber partitioned from the planetary gear chamber via a partition wall, and the differential mechanism Is accommodated in a differential mechanism chamber partitioned from the transmission gear chamber and the planetary gear chamber via a partition wall, and is provided with a hydraulic pressure provided in the transmission case. The planetary gear chamber and the transmission gear chamber are partitioned so that oil from the hydraulic transmission mechanism that flows into the planetary gear chamber via a port flows into the differential mechanism chamber via the transmission gear chamber. The partition walls that partition the partition wall, the transmission gear chamber, and the differential mechanism chamber are each provided with a circulation port, and the differential mechanism is provided via an oil outlet provided in a front axle case fixed to the differential mechanism chamber. shall der oil flowing into the chamber is drawn by the charge pump is, the from the hydraulic return port further away the oil outlet, and effectively prevent foaming of oil, evacuation of good oil by the charge pump It is possible to easily maintain the performance of the hydraulic transmission mechanism.
[0004]
For example, the charge pump is driven by a drive shaft disposed coaxially with the pump shaft and connected to the pump shaft .
[0005]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below in detail with reference to the drawings. 1 is a side view of the whole, FIG. 2 is a plan view of the same, FIG. 3 is a side view of a vehicle body frame, FIG. 4 is a plan view of the body, and 1 is a traveling vehicle on which an operator rides. Mounted on the vehicle body frame 3, the front wheel 6 for paddy field traveling is supported on the side of the transmission case 4 via the front axle case 5, and the rear wheel 8 for paddy field traveling is supported on the rear axle case 7 behind the transmission case 4. The spare seedling stage 10 is attached to both sides of the bonnet 9 that covers the engine 2 and the like, and the mission case 4 and the like are covered by a vehicle body cover 11 on which an operator rides, and a seat frame 12 is disposed on the rear upper side of the vehicle body cover 11 via a seat frame 12. A driver's seat 13 is attached, and a steering handle 14 is provided at the rear of the bonnet 9 in front of the driver's seat 13.
[0006]
In the figure, reference numeral 15 denotes a planting part having a seedling mounting table 16 for five-row planting and a plurality of seedling planting claws 17. The planting case 20 is supported by the planting case 20 through the lower rail 18 and the guide rail 19 so as to be slidable in the left and right directions, and a rotary case 21 that rotates at a constant speed in one direction is supported by the planting case 20. A pair of nail cases 22 and 22 are arranged at symmetrical positions around the axis, and seedling planting nails 17 and 17 are attached to the tips of the nail cases 22 and 22.
[0007]
Further, the hitch bracket 23 on the front side of the planting case 20 is connected to the rear side of the traveling vehicle 1 through an elevating link mechanism 26 including a top link 24 and a lower link 25, and the planting unit 15 is moved up and down via the link mechanism 26. The hydraulic lifting cylinder 27 is connected to the lower link 25, and the front and rear wheels 6 and 8 are driven to move, and at the same time, the seedlings 16 are slid back and forth, and one seedling is planted by the planting claws 17. It is configured to carry out rice transplanting work to take out and plant seedlings continuously.
[0008]
In the figure, 28 is a main speed change lever, 29 is a planting operation lever for raising and lowering the planting part 15, planting clutch on / off, and marker operation, 30 is a brake pedal, 31 is a speed change pedal, 32 is a diff lock pedal, 33 is a sensitivity adjusting lever, 34 is a stop lever for stopping the planting portion 15 at an arbitrary height position, and 35 is a unit clutch lever 35. The shift and elevating levers 28 and 29, brakes and shifts are located near the steering handle 14 position. The pedals 30 and 31 are disposed, and the sensitivity adjustment and stop and unit clutch levers 33, 34, and 35 and the differential lock pedal 32 are disposed in the vicinity of the position of the driver's seat 13.
[0009]
Further, in the figure, 36 is a center float for leveling of one strip, 37 is a side float for leveling of two strips, 38 is a float 36 through the flexible conveying hose 41 with fertilizer in the fertilizer hopper 39 by the blowing force of the blower 40. -It is a 5-way side strip fertilizer machine which makes it discharge to 37 side strip groover 42.
[0010]
3 to 5, the vehicle body frame 3 is divided into a front frame 43, an intermediate frame 44, and a rear frame 45. The engine 2 is connected to the pair of left and right front frames 43, and the pair of left and right intermediate frames 44. A front axle case 5, a pair of left and right rear frames 45 are provided with a rear axle case 7 and a fuel tank 46 for supplying fuel to the engine 2. A front frame 47 and a base frame 48 are provided between the front side and the middle of the front frame 43. Are connected to form a quadrangular frame shape in plan view, and the engine 2 is mounted on the fixed bracket 49 and the base frame 48 via vibration-proof rubber.
[0011]
Further, as shown in FIG. 10, the intermediate rising portion 50 of the rear frame 45 is connected in a substantially parallel manner by a pipe frame 51 and a portal frame 52, and a portal frame 53 in which the left and right lower ends are fixed to the rear axle case 7. The fuel tank 46 is disposed between the left and right rising portions 50 by connecting the rear ends of the rear ends.
[0012]
Further, the front and rear ends of the left and right intermediate frame 44 are detachably fixed to the rear end of the front frame 43 and the front end of the rear frame 45 via bolts 54, and the left and right front axle cases are fixed to the lower surface of the left and right intermediate frames 44 via bolts 55. The left and right front axle case 5 is connected and fixed to the transmission case 4.
[0013]
As shown in FIGS. 6 to 9, a power steering case 56 is provided on the front left side of the transmission case 4 and a continuously variable hydraulic transmission mechanism 57 is provided on the right side of the case 4. And the pump shaft 58 is connected to the transmission shaft 59 in the front-rear direction at the lower side of the engine 2, and the transmission shaft 59 is connected to the output shaft 60 of the engine 2 via the transmission belt 61. Two outputs are transmitted to the hydraulic transmission mechanism 57.
[0014]
Further, the transmission case 4 and the rear axle case 7 are integrally connected by a connecting frame 62 made of pipe on the center line in the longitudinal direction of the vehicle body, and the rear output shaft 63 and the PTO output shaft 64 are projected to the rear of the transmission case 4 so that the rear axle is The rear output shaft 63 is connected via a rear transmission shaft 66 to a rear input shaft 65 that protrudes forward of the case 7, and power is transmitted from the traveling output shaft 63 to the left and right rear wheels 8. Further, the PTO output shaft 64 is connected via a universal joint shaft 69 to an intermediate shaft 68 provided on the bearing 67 at the upper part of the rear axle case 7, and the intermediate shaft 68 is connected to the input shaft of the planting case 20 via a universal joint shaft. Power is transmitted from the PTO output shaft 64 to the planting unit 15.
[0015]
Further, as shown in FIGS. 11 to 20, the transmission case 4 includes a main body barrel 70, a front lid 71, and a rear lid 72, and each lid 72 can be attached to and removed from the front and rear of the trunk 70. A partition wall portion 73 that divides the inside of the body portion 70 into the front and the rear is provided. Further, the hydraulic transmission mechanism 57 is attached to the front surface of the front lid portion 71, a small-diameter transmission gear 74 is supported on the pump shaft 58 that protrudes into the transmission case 4, and the transmission gear 74 is attached to the front lid portion 71 as a bearing bearing. Then, the power of the transmission gear 74 is transmitted via the pipe shaft 76 to the charge pump 75 that is fixed to the rear surface of the rear lid portion 72.
[0016]
Further, a sun gear 78 is supported on the motor shaft 77 of the hydraulic transmission mechanism 57 that protrudes into the transmission case 4, and the sun gear 78 is bearing-supported on the front lid 71, and the small-diameter transmission gear 74 is large. The carrier gear 79 having a diameter is always meshed with the boss of the sun gear 78 and the carrier gear 79 is supported on the free rotation shaft. And a ring gear 82 that meshes with the planetary gear 80 is provided, and the planetary gear mechanism 83 is formed by the gears 78, 80, and 82.
[0017]
Further, the sun gear 78 and the rear cover portion 72 are rotatably supported on the front and rear of the combined output shaft 84, and the ring gear 82 is supported on the combined output shaft 84 to be engaged with the hydraulic pump 85 of the hydraulic transmission mechanism 57. And the forward / reverse rotation output, which is a continuously variable hydraulic shift output of the hydraulic motor 86, and the reduced rotation output (one-way constant rotation) of the transmission gear 74 and the carrier gear 79 are combined by the differential action of the planetary gear mechanism 83 to obtain zero. Or transmitted to the combined output shaft 84 as a rotational force in one direction at the maximum speed.
[0018]
Furthermore, a forward gear 87 and a reverse gear 88 are supported on the combined output shaft 84 as idle shafts, and the gears 87 and 88 are selectively engaged with the combined output shaft 84 by a slider 89 to output forward, neutral or reverse. In addition, the rear output shaft 63 is bearing-bearing on the partition wall portion 73 and the rear lid portion 72. Further, a front output shaft 92 that transmits power to the left and right front axles 91 via a differential gear 90 and a counter shaft 94 that supports the PTO transmission gear 93 are provided, and the rear and front output shafts 63 and 92 are provided. The rear power of the reverse gear 88 is transmitted to the rear output shaft 95 through the output gears 95 and 96 to drive the front and rear wheels 6 and 8 in reverse, and the rear output shaft 63 is supported by the movable gear 97 and the planting gear 98 for rotation. The gears 97 and 98 are selectively engaged with the rear output shaft 63 by the speed change slider 99.
[0019]
Further, the moving gear 97 is always meshed with the forward gear 87 via the high speed gear 100 of the counter shaft 94, and the planting gear 98 is always meshed with the low speed PTO transmission gear 93 of the counter shaft 94. The power of the forward gear 87 is transmitted to the output shafts 63 and 92 through 93 and 98, and the front and rear wheels 6 and 8 are driven forward at the seedling planting operation speed. In addition, the PTO output shaft 64 is manually rotated so that both the moving gear 97 and the planting gear 98 are in an idle state, and the planting claw 17 and the like can be manually rotated by the operator to remove the seedling clogged. In addition, the power of the forward gear 87 is transmitted to the output shafts 63 and 92 via the gears 100 and 97, and the front and rear wheels 6 and 8 are driven forward at a high moving speed such as road movement between fields. .
[0020]
Further, as shown in FIG. 12, the power of the PTO transmission gear 93 is transmitted to the PTO output shaft 64 via the PTO transmission shaft 101 and the PTO transmission mechanism 102 to drive the planting portion 15 so as to be able to shift between the stocks. The fertilizer output shaft 104 is connected to the PTO output shaft 64 via the chain 103 installed in the plant, and the fertilizer machine 38 is driven in synchronization with the planting unit 15. Further, as shown in FIG. 13, the transmission case 4 is provided with an oil gauge 105, and as shown in FIG. 14, the sliders 89 and 99 are locked to the same shift fork 106, and the shift lever 28 is switched by five positions. Switch between forward / reverse and sub-shift (low / high speed). Further, as shown in FIGS. 16 to 18, the hydraulic speed change operation arm 109 is connected to the swash plate 107 of the hydraulic pump 85 via the control shaft 108, and the speed change pedal 31 is connected to the arm 109 via the rod 110. The spring 111 for automatically returning the pedal 31 to the stop (zero speed) position when the pedal 31 is released is connected to the arm 109, and the oil damper 112, which is a constant speed operating member, is connected to the arm 109. When the foot is released from the pedal 31 that has been stepped on, the pedal 31 returns at a gentle and substantially constant speed due to the resistance of the oil damper 112 and the return force of the spring 111, and the operation gradually decreases. Instead of the oil damper 112, a constant speed operation member may be formed by a gas spring or the like.
[0021]
Further, as shown in FIG. 20, when the pedal 31 is returned to the stop (zero speed) position by the spring 111 with the foot off the pedal 31, the sun gear 78 reverses clockwise at the maximum rotation and the planetary gear. At the same time, the carrier gear 79 is rotated by the transmission gear 74 to rotate the planetary gear 80 in the counterclockwise direction, and the planetary gear 80 is rotated in the clockwise direction to rotate counterclockwise. , And the composite output shaft 84 is stopped and maintained. When the pedal 31 is stepped on to the middle position (medium speed range) against the spring 111, the sun gear 78 stops, the carrier gear 79 is rotated by the transmission gear 74, and the planetary gear 80 is rotated clockwise. Then, the combined output shaft 84 is rotated by the gear power of the transmission gear 74. Further, when the pedal 31 is fully depressed, the sun gear 78 rotates in the counterclockwise direction at the maximum rotation, and the planetary gear 80 rotates in the clockwise direction while the carrier gear 79 is rotated in the clockwise direction while rotating in the clockwise direction. The combined output shaft 84 is rotated by adding the hydraulic transmission force from the sun gear 78 and the transmission gear 74 power, and the engine 2 power is transmitted to the transmission gear 74 and the hydraulic transmission mechanism 57 as shown in FIG. The planetary gear mechanism 83 synthesizes and outputs, and the mission case 4 performs forward / reverse switching and PTO speed change to perform reverse, low speed forward (farm planting travel), and high speed forward (road movement travel) operations.
[0022]
Then, for example, as shown in FIG. 22, the angle of the hydraulic speed change operation arm 109 is changed from −1 to 0 to 1, so that the motor shaft 77 becomes −1000 to 0 to 1000 rotations, and as shown in FIG. Further, when the gear 74 side is rotated 1000 times regardless of the angle of the arm 109, the gear 74 is set so that the combined output shaft 84 is 0 to 2000 rotations relative to the angle of the arm 109 as shown in FIG. -Composition 79 and planetary gear mechanism 83.
[0023]
Further, when the entire control range of the arm 109 is set to −1 to 0 to 1, as shown in FIG. 19, the control operation on the low speed (zero speed) side and high speed side of the arm 109 is changed to the bolt type low speed and high speed stopper 113.・ Controlled by 114, and as shown in FIG. 25, the operation range of the actual arm 109 adjustable by the stoppers 113 and 114 is set to −0.8 to 0.6, and the work of 0 to 1.4 m / S is performed. By obtaining the speed, adjustment is made by the stoppers 113 and 114 with respect to variations in output characteristics caused by assembly errors of the hydraulic transmission mechanism 57 and the position of the arm 109, for example, -1 to 0.8 is adjusted. Thus, the speed can be made zero, and the problem that the speed does not become zero even if the arm 109 is −1 is eliminated. As shown in FIGS. 26 and 27, at a general work speed, the power sharing ratio between the hydraulic transmission mechanism 57 and the gear 74 is set to 60% or more, and the effective power on the gear 74 side with respect to the effective power of the hydraulic transmission mechanism 57. Increase the ratio of the paddy field, improve the running performance in the wet field, improve the working efficiency in the wet field, and give the escape level enough for the step of the cultivator.
[0024]
As shown in FIG. 15, one side of the transmission gear 74 that meshes with the carrier gear 79 of the planetary gear mechanism 83 to drive the gear 79 is detachably fitted to the spline shaft 58a of the pump shaft 58, and A complex transmission mechanism 115 is provided on the other side of the gear 74 by fitting and fixing a pipe shaft 76 to form a combined output of the hydraulic transmission mechanism 57 and the planetary gear mechanism 83. Then, by providing the pump shaft 58 that is the input shaft of the hydraulic transmission mechanism 57 and the transmission gear 74 that is the driving gear of the planetary gear mechanism 83 on the pipe shaft 76, the planetary gear is separated from the pump shaft 58 of the hydraulic transmission mechanism 57. It eliminates the complexity of a structure in which a gear shaft dedicated to the drive gear for driving the gear mechanism 83 is installed at a separate location, and is a simple means using the pump shaft 58 of the hydraulic transmission mechanism 57. Therefore, it is possible to effectively transmit the shift output of the complex transmission mechanism 115 having a high transmission efficiency.
[0025]
Also, a pump shaft 58 of the hydraulic transmission mechanism 57 and a pipe shaft 76 that is a drive shaft for driving a pump 75 that supplies hydraulic pressure to a hydraulic mechanism such as the hydraulic transmission mechanism 57 provided on the same axis as the pump shaft 58; By using this, it is possible to support the transmission gear 74 with high strength and stability, and it is possible to arrange the pump 75 drive unit in a compact manner.
[0026]
Further, a planetary gear mechanism 83 is provided on a motor shaft 77 that is an output shaft of the hydraulic transmission mechanism 57. One side inner surface portion of the sun gear 78 is detachably fitted to the spline shaft 77a of the motor shaft 77, and The side outer surface portion is rotatably supported by the front lid portion 71 via a bearing 116, and the other side of the sun gear 78 is idled and supported by the composite output shaft 84 via a bearing member 117. A planetary gear mechanism 83 and a driving gear 74 are provided in the extension direction of the motor shaft 77 and the pump shaft 58 of the hydraulic transmission mechanism 57, and the shape of the hydraulic transmission mechanism 57 is slightly extended in the axial direction. The transmission mechanism 115 can be formed into a compact and compact one with a narrow width. By providing the planetary gear mechanism 83 on the motor shaft 77 of the hydraulic transmission mechanism 83, the planetary gear mechanism 83 is compactly and compactly provided in the transmission case 4. Is incorporated so that the mission case 4 can be easily reduced in size and weight.
[0027]
Further, one side of the sun gear 78 is supported by the front lid portion 71 of the transmission case 4 and the other side is supported by the composite output shaft 84, and the carrier gear 79 and the output shaft 84 are supported by the outer peripheral surface of the sun gear 78 and the spline 84a. A planetary gear 80 is arranged between the ring gears 82 to be fitted, and the planetary gear mechanism 83 is shortened in the axial direction so that the composite transmission mechanism 115 can be made more compact.
[0028]
As shown in FIG. 6, a hydraulic transmission mechanism 57 is wrapped in a plan view below the front vehicle body cover 11a of the vehicle body cover 11 that is dividedly formed into the front vehicle body cover 11a and the rear vehicle body cover 11b, and maintenance of the engine 2 and the belt 61 is performed. Sometimes, the maintenance of the transmission mechanism 57 can be easily performed only by removing the front vehicle body cover 11a, and the heavy-duty transmission mechanism 57 is arranged at the front side position of the transmission case 4 to improve the front-rear balance of the aircraft. It is configured as follows.
[0029]
As shown in FIGS. 11, 12, and 28 to 30, the transmission case 4 includes a planetary gear chamber 118 having a planetary gear mechanism 83, a transmission gear chamber 119 having forward / reverse gears 87 and 88, a PTO transmission mechanism 102, and the like. A differential gear chamber 120 having a differential gear 90 and the like is provided, and has three gear chambers 118, 119, and 120 divided for each function, and a planetary gear chamber in a plan view as shown in FIG. The transmission gear chamber 119 and the differential gear chamber 120 are disposed on the rear side and the left side of the 118, and the differential gear 90 is disposed close to the left side of the planetary gear mechanism 83, so that the front-rear width of the transmission case 4 is shortened and reduced in size. It is configured to become.
[0030]
In addition, a suction port 122 is provided in a connection case 121 of the left front axle case 5 that is fixedly connected to the differential gear chamber 120, and the suction port 122 is connected to the charge pump 75 or the like via a hydraulic hose 123 so that a transmission case is provided. 4 is configured to supply hydraulic oil stored in 4 to the hydraulic transmission mechanism 57 and the like via a charge pump 75.
[0031]
A suction port 122 is provided at a position remote from the hydraulic return port 124 of the hydraulic transmission mechanism 57 provided in the planetary gear chamber 118 to effectively prevent oil bubbles and the like, and the planetary gear chamber 118 and the transmission gear chamber 119. In addition, oil circulation ports 126 and 127 are appropriately opened in the partition wall portions 73 and 125 partitioning the transmission gear chamber 119 and the differential gear chamber 120, and the hydraulic oil stored in the planetary gear chamber 118 is supplied to the circulation ports 126 and 127. Are sequentially fed into the transmission gear chamber 119 and the differential gear chamber 120 and sucked out from the suction port 122 to further prevent the foaming of oil and to supply the hydraulic pressure to the charge pump 75 and the like in a satisfactory manner. .
[0032]
A differential lock lever 129 (interlocked with the differential lock pedal 32 via an interlocking mechanism not shown) for turning on and off the differential lock mechanism 128 of the differential gear 90 is provided at a position opposite to the suction port 122 of the connection case 121. In addition, a traveling brake 132 is provided on the front output shaft 92 to be connected to the brake pedal 30 via a brake lever shaft 130 and a brake lever 131.
[0033]
As is clear from the above, the transmission output of the hydraulic transmission mechanism 75 is transmitted to the wheels through the planetary gear mechanism 83 in the mission case 4, the forward / reverse gears 87 and 88 as the transmission gear mechanism, and the differential gear 90 as the differential mechanism. In a work vehicle for driving a certain front wheel 6, the planetary gear mechanism 83, the forward / reverse gears 87 and 88, and the differential gear 90 are provided in partitioned compartments 118, 119, and 120 in the mission case 4, thereby providing each function. Another gear 87, 88, 90 and mechanism 83 are arranged to simplify the structure and facilitate the assembly, and reduce the thickness of the mission case 4 while maintaining the rigidity. It is possible to easily reduce the weight.
[0034]
Further, the hydraulic oil stored in the transmission case 4 is circulated to the suction port 122 which is the oil outlet of the front axle case 5 through the planetary gear chamber 118, the transmission gear chamber 119, and the differential gear chamber 120 which are each gear mechanism chamber. By removing the oil, the divided gear chambers 118, 119, and 120 are sequentially circulated, and the suction port 122 is moved away from the oil return port 124 to effectively prevent foaming of the oil. It is possible to easily perform good oil suction and the like, and the performance of the hydraulic transmission mechanism 57 can be stably maintained.
[0035]
As shown in FIG. 31, it is also possible to install a vehicle speed transmission mechanism 130 that performs forward / reverse / moving speed shifting on the input side of the hydraulic transmission mechanism 57, which includes forward / reverse gears 87, 88 and moving / planting. A shift output from the vehicle speed transmission mechanism 130 having the high speed gears 97, 98, 100, etc. is input to the pump shaft 58 of the hydraulic pump 85 constituting the composite transmission mechanism 115, and a combined output from the combined output shaft 84 of the composite transmission mechanism 115 Is transmitted to the front output shaft 92 and the rear output shaft 63 via the output gears 95 and 96, etc., and the front and rear wheels 6 and 8 are configured to move forward (moving speed), move forward at low speed (planting speed), and move backward. Thus, for example, the zero adjustment of the speed when the arm 109 is −1 can be reliably performed, and the accuracy of the zero start operation of the airframe can be easily improved.
[0036]
【The invention's effect】
As is apparent from the above embodiments, the present invention transmits the shift output of the hydraulic transmission mechanism 57 to the wheel 6 through the planetary gear mechanism 83, the transmission gear mechanisms 87 and 88, and the differential mechanism 90 in the transmission case 4 to In the working vehicle for driving, the planetary gear mechanism 83, the transmission gear mechanisms 87 and 88, and the differential mechanism 90 are provided in the planetary gear chamber 118, the transmission gear chamber 119, and the differential gear chamber 120, respectively , which are partitioned in the transmission case 4 . Therefore, the mechanism 83, 87, 88, 90 for each function is arranged to simplify the structure and facilitate the assembly, while maintaining the rigidity of the transmission case 4 It is possible to make the mission case 4 lightweight easily by effectively reducing the thickness of the transmission case 4.
[0037]
Further, the oil from the hydraulic transmission mechanism 57 that flows into the planetary gear chamber 118 through the hydraulic return port 124 provided in the transmission case 4 passes through the transmission gear mechanism chamber 119 and the differential mechanism chamber 120. A flow port 126 is provided in the partition wall 73 that partitions the planetary gear chamber 118 and the transmission gear chamber 119 so as to flow in, and a flow port 127 is provided in the partition wall 125 that partitions the transmission gear chamber 119 and the differential mechanism chamber 120. Since the oil that has flowed into the differential mechanism chamber 120 through the oil outlet 122 of the front axle case 5 fixed to the differential mechanism chamber 120 is sucked by the charge pump 85, each partitioned mechanism chamber 118 - 119 - 120 are sequentially distributed, further away the oil exit 122 from the return port 124, and effectively prevent the foaming of the oil Wherein by the like to readily good oil evacuation by the charge pump 85, in which it is possible to stabilize the holding of the performance of the hydraulic transmission mechanism 57.
[Brief description of the drawings]
FIG. 1 is an overall side view of a rice transplanter.
FIG. 2 is an overall plan view of a rice transplanter.
FIG. 3 is a side view of a traveling vehicle body.
FIG. 4 is a plan view of a traveling vehicle body.
FIG. 5 is a side view of the vehicle body frame.
FIG. 6 is an explanatory side view of a drive unit.
FIG. 7 is an explanatory plan view of a drive unit.
FIG. 8 is an explanatory side view of a side clutch operation system.
FIG. 9 is an explanatory plan view of a side clutch operation system.
FIG. 10 is a perspective explanatory view of a vehicle body.
FIG. 11 is a cross-sectional view of a mission case.
FIG. 12 is an enlarged view of the same.
FIG. 13 is an explanatory diagram of a planetary gear mechanism.
FIG. 14 is a partial view of a mission case.
FIG. 15 is a cross-sectional view of a planetary gear mechanism.
FIG. 16 is a perspective view from the front of the shift pedal unit.
FIG. 17 is a perspective view from the rear upper side of the shift pedal portion.
FIG. 18 is an explanatory diagram of a gear arrangement of a mission case.
FIG. 19 is a side view of a hydraulic speed change operation arm portion.
FIG. 20 is an explanatory diagram of rotation of the planetary gear mechanism.
FIG. 21 is an explanatory diagram of engine output.
FIG. 22 is an explanatory diagram of the output of the hydraulic transmission mechanism.
FIG. 23 is an explanatory diagram of output on the transmission gear side.
FIG. 24 is an explanatory diagram of output of a composite output shaft.
FIG. 25 is an explanatory diagram showing a shift of a shift pedal.
FIG. 26 is a correlation diagram between a hydraulic shift output and a gear shift output.
FIG. 27 is a correlation diagram between the output of FIG. 26, hydraulic pressure loss, and gear loss.
FIG. 28 is an explanatory plan view of a mission case.
FIG. 29 is a plan sectional view of the mission case.
FIG. 30 is a side sectional view of the mission case.
FIG. 31 is another explanatory diagram of driving of the composite speed change mechanism.
[Explanation of symbols]
4 Mission case 5 Front axle case 6 Front wheel
57 Hydraulic transmission mechanism
58 pump shaft
73/125 partition wall
75 charge pump
76 pipe shaft (drive shaft)
83 Planetary gear mechanism 87/88 Gear (Gear mechanism)
90 Differential gear (Differential mechanism)
118/119/120 Gear chamber (Gear mechanism chamber)
120 Suction port (oil outlet)
124 hydraulic return
126/127 distribution port

Claims

In a work vehicle that transmits a shift output of a hydraulic transmission mechanism to a wheel via a planetary gear mechanism, a transmission gear mechanism, and a differential mechanism in a mission case, and drives the wheel.
The hydraulic transmission mechanism is fixed to the transmission case with a pump shaft and a motor shaft protruding into the transmission case,
The planetary gear mechanism is housed in the planetary gear chamber of the transmission case in a state where power from the engine is input via the pump shaft and power from the hydraulic transmission mechanism is input via the motor shaft. The gear mechanism is accommodated in a transmission gear chamber partitioned from the planetary gear chamber via a partition wall, and the differential mechanism is accommodated in a differential mechanism chamber partitioned from the transmission gear chamber and the planetary gear chamber via a partition wall. Has been
The planetary gear is configured such that oil from the hydraulic transmission mechanism that flows into the planetary gear chamber through a hydraulic return port provided in the transmission case flows into the differential mechanism chamber through the transmission gear chamber. A flow port is provided in each of the partition wall partitioning the chamber and the transmission gear chamber, and in the partition wall partitioning the transmission gear chamber and the differential mechanism chamber,
A working vehicle characterized in that oil flowing into the differential mechanism chamber is sucked by a charge pump through an oil outlet provided in a front axle case fixed to the differential mechanism chamber .

The work vehicle according to claim 1 , wherein the charge pump is driven by a drive shaft that is disposed coaxially with the pump shaft and connected to the pump shaft .