JP4465800B2

JP4465800B2 - Work vehicle safety frame

Info

Publication number: JP4465800B2
Application number: JP2000119882A
Authority: JP
Inventors: 英和辻
Original assignee: Iseki and Co Ltd
Current assignee: Iseki and Co Ltd
Priority date: 2000-04-20
Filing date: 2000-04-20
Publication date: 2010-05-19
Anticipated expiration: 2020-04-20
Also published as: JP2001301553A

Description

【０００１】
【発明の属する技術分野】
本発明は作業車両の安全フレームに関するものであり、特に、起立倒回可能な安全フレームに関するものである。
【０００２】
【従来の技術及び発明が解決しようとする課題】
従来、此種作業車両でキャビンにルーフのないものは、車体転倒時にオペレータを保護するために安全フレームが設けられている。一般的には運転席の後左右側方にブラケットを固設し、夫々のブラケットに正面視「門」形の安全フレームの左右下端部を取付けている。該安全フレームの高さはオペレータの着座姿勢より高くしてあるので、車体走行時に該安全フレームが木の枝に接触したり、車体格納時に納屋の入り口や天井に衝突することがある。
【０００３】
このため、該安全フレームの下端部を夫々のブラケットに起立倒回可能に枢着し、通常の作業を行うときは、左右のブラケットのロック位置に位置決めピンを差込んで該安全フレームを起立状態に固定し、該安全フレームを倒回するときは、左右の位置決めピンをロック位置から引き抜いてアンロックするように構成してある。或いは、左右のブラケットにレバーを設け、夫々のレバー操作により位置決めピンをロック位置またはアンロック位置に移動するようにしている。しかし、位置決めピンのロックまたはアンロックを左右別個に行うので、安全フレームの起立倒回操作が煩雑であった。
【０００４】
そこで、安全フレームを起立倒回可能に取付けた作業車両に於いて、該安全フレームのロック及びアンロックを簡単に行うために解決すべき技術的課題が生じてくるのであり、本発明はこの課題を解決することを目的とする。
【０００５】
【課題を解決するための手段】
本発明は上記目的を達成するために提案されたものであり、運転席（１７）の後方に、車体正面から視て「門」形に形成される安全フレーム（２０）を立設するとともに、該安全フレーム（２０）の左右の基端部を車体に固定したブラケット（２２Ｌ），（２２Ｒ）に対し回動可能に連結する作業車両であり、前記安全フレーム（２０）の左右基端部の取付金具（３１Ｌ），（３１Ｒ）と左右のブラケット（２２Ｌ），（２２Ｒ）とを単一の係止ロッド（３２）を貫通して設け、該係止ロッド（３２）には小径部（３２ａ）と左右一側の端部近傍に設けた大径部（３２ｂ）とを備え、該大径部（３２ｂ）が設けられる側のブラケット（２２Ｌ）側面には、該係止ロッドの大径部（３２ｂ）が挿入でき且つ前記安全フレーム（２０）の回動を停止するロック用位置決め孔（３３），（３４）と、該係止ロッドの小径部（３２ａ）が挿入でき且つ前記安全フレーム（２０）の回動を許容する長孔（３５）からなるアンロック用位置決め孔とを設け、更に、係止ロッド（３２）の片側に該係止ロッド（３２）を左右に移動させる操作レバー（３０）を設けて前記係止ロッド（３２）の大径部（３２ｂ）を前記位置決め孔（３３），（３４）に抜き差し可能に形成した作業車両の安全フレーム（２０）に於いて、
上記操作レバー（３０）を該係止ロッド（３２）の一側で上記ブラケット（２２Ｌ）の外側板（２２Ｌ₁）の外面に側面視「へ」字状のプレート（３６）を固設するとともに、前記係止ロッド（３２）の大径部（３２ｂ）にストッパピン（３７ａ，３７ｂ）を上下反対方向に夫々突設し、前記操作レバー（３０）の回動操作にて該ストッパピン（３７ａ又は３７ｂ）が前記プレート（３６）の内面に接離するように形成し、また、上記係止ロッド（３２）の他側の端部近傍に該係止ロッド（３２）と同軸に円筒状駆動カム（４０）を設けると共に、前記取付金具（３１Ｒ）の内側取付板（３１Ｒ₂）の内面に中空円筒状の従動カム（４１）を固設し、前記駆動カム（４０）のカム斜面は円柱の１８０度対向した位置に凸部（４０ａ，４０ａ）を有し、該凸部（４０ａ，４０ａ）に対し、９０度の位相差を以って凹部を有して成り、
一方、前記従動カム（４１）の凸部（４１ａ）は、駆動カム（４０）の凹部と係合するときに９０度の位相差で係合する各凸部（４１ａ，４１ａ）を有し、該従動カム（４１）の中空部に駆動カム（４０）と一体をなす係止部（３２ｃ）が回転可能に挿入されてなり、該係止部（３２ｃ）にストッパ（４２）が嵌着され該ストッパ（４２）と前記取付金具（３１Ｒ）の内側取付板（３１Ｒ₂）の内面との間にコイルバネ（４３）を介装し、係止ロッド（３２）を伸び方向に付勢し、従動カム（４１）にて駆動カム（４０）を常に圧接するように構成した作業車両の安全フレームを提供するものである。
【０００６】
【発明の実施の形態】
以下、本発明の一実施の形態を図面に従って詳述する。図１は作業車両の一例としてトラクタ１０の側面を示し、該トラクタ１０は左右一対の前輪１１，１１１と後輪１２，１２を有し、車体前部にエンジン１３を搭載するとともに車体後部にミッションケース１４を設け、車体の後部にはリンク装置１５によりロータリ等の作業機１６が連結される。ミッションケース１４の上方に運転席１７を設け、運転席１７の前方にステアリングハンドル１８を設けて前輪１１，１１を操向する。
【０００７】
前記運転席１７の後方には、安全フレーム２０が設けられている。該安全フレーム２０は角パイプまたは丸パイプ等にて正面視「門」形に形成され、車体の左右に立設した下部フレーム２１，２１の上端部に夫々ブラケット２２Ｌ，２２Ｒを固設し、夫々のブラケット２２Ｌ，２２Ｒに該安全フレーム２０の左右下端部を揺動軸２３，２３にて枢着してある。ボルトからなる揺動軸２３，２３を中心に該安全フレーム２０は前後に回動可能であり、後述するように、操作レバー３０にて該安全フレーム２０を起立状態にロックし、或いは、操作レバー３０にて該安全フレーム２０をアンロックして後方へ倒回可能に形成されている。
【０００８】
図２に示すように、前記安全フレーム２０の左右下端部には取付金具３１Ｌ，３１Ｒが溶接されており、夫々の取付金具３１Ｌ，３１Ｒは外側取付板３１Ｌ₁，３１Ｒ₁と内側取付板３１Ｌ₂，３１Ｒ₂とを対向して平面視後部開口の「コ」字状に形成されている。一方、前記ブラケット２２Ｌ，２２Ｒは、底板２２Ｌ₀，２２Ｒ₀の上面に外側板２２Ｌ₁，２２Ｒ₁と内側板２２Ｌ₂，２２Ｒ₂とを対向して正面視上部開口の「コ」字状に形成されている。
【０００９】
そして、左のブラケット２２Ｌの外側板２２Ｌ₁と内側板２２Ｌ₂の内側に左の取付金具３１Ｌの外側取付板３１Ｌ₁と内側取付板３１Ｌ₂が収納され、左の取付金具３１Ｌ及び左のブラケット２２Ｌを貫通して揺動軸２３を挿通することにより、該揺動軸２３を中心に左の取付金具３１Ｌが前後回動する。これと同様に、右のブラケット２２Ｒの外側板２２Ｒ₁と内側板２２Ｒ₂の内側に右の取付金具３１Ｒの外側取付板３１Ｒ₁と内側取付板３１Ｒ₂が収納され、右の取付金具３１Ｒ及び右のブラケット２２Ｒを貫通して揺動軸２３を挿通することにより、該揺動軸２３を中心に右の取付金具３１Ｒが前後回動する。従って、前記安全フレーム２０が左右のブラケット２２Ｌ，２２Ｒを中心に起立倒回可能となる。
【００１０】
前記安全フレーム２０の左右下端部に溶接された取付金具３１Ｌ，３１Ｒと、左右のブラケット２２Ｌ，２２Ｒとを左右方向にスライド可能な係止ロッド３２にて貫通し、少なくとも一方のブラケット２２Ｌまたは２２Ｒに、安全フレーム２０の回動を固定するロック位置と安全フレーム２０の回動を許容するアンロック位置を設ける。前記係止ロッド３２は中央部分に小径部３２ａを有し、少なくとも一方の端部に大径部３２ｂを備えている。
【００１１】
本実施の形態では、図３及び図４に示すように、係止ロッド３２の左側の端部近傍に大径部３２ｂを設け、該大径部３２ｂが設けられた左側のブラケット２２Ｌの内側板２２Ｌ₂に、安全フレーム２０が起立状態のときに該大径部３２ｂが挿入でき且つ安全フレーム２０の回動を停止する位置決め孔３３を開穿するとともに、安全フレーム２０が倒回状態のときに該大径部３２ｂが挿入でき且つ安全フレーム２０の回動を停止する位置決め孔３４を開穿する。即ち、該大径部３２ｂは前記位置決め孔３３，３４に嵌合可能な位置決めピンとして作用する。また、前記揺動軸２３を中心として位置決め孔３３，３４の夫々の中心点を結ぶ円周上に、円弧状の長孔３５を開穿して双方の位置決め孔３３と３４とを連通する。該長孔３５の幅は前記大径部３２ｂよりも狭く、且つ、前記小径部３２ａが挿入できる寸法に形成されている。後述するように、前記位置決め孔３３，３４は安全フレーム２０の回動を停止するロック位置となり、該長孔３５は安全フレーム２０の回動を許容するアンロック位置となる。
【００１２】
そして、前記係止ロッド３２の片側に操作部である操作レバー３０を設け、前記ブラケット２２Ｌの外側板２２Ｌ₁の外面に側面視「ヘ」字状のプレート３６を固設するとともに、前記係止ロッドの大径部３２ｂにストッパピン３７ａ，３７ｂを上下反対方向に夫々突設し、前記操作レバー３０を回動操作したときに、このストッパピン３７ａまたは３７ｂが前記プレート３６の内面に接離するように形成する。図示した状態は、係止ロッドの大径部３２ｂが一方の位置決め孔３３に嵌入しており、安全フレーム２０が起立状態にロックされている。
【００１３】
図５に示すように、係止ロッド３２の右側の端部近傍には係合ロッド３２と同軸に駆動カム４０を設け、前記取り付け金具３１Ｒの内側取付板３１Ｒ₂の内面に中空円筒状の従動カム４１を固設する。駆動カム４０のカム斜面は円柱の１８０度対向した位置に凸部４０ａ，４０ａを有し、この凸部４０ａ，４０ａに対して９０度の位相差を持って凹部を有しており、各凸部４０ａ，４０ａには係止ロッド３２の回転方向に平坦な面取りを施してある。一方、従動カム４１は、前記駆動カム４０と９０度の位相差で形成され、各凸部４１ａ，４１ａに平坦な面取りが施され、該従動カム４１の中空部に前記駆動カム４１の中空部に前記駆動カム４０と一体の係止部３２ｃが回転可能に挿入されている。
【００１４】
前記係止部３２ｃにはストッパ４２が嵌着され、このストッパ４２と前記取付金具３１Ｒの内側取付板３１Ｒ₂の内面との間にコイルバネ４３を介装して、係止ロッド３２を伸び方向に付勢している。即ち、前記駆動カム４０は常に従動カム４１に圧接された状態となり、同図では駆動カム４０の凸部４０ａが従動カム４１の凹部に接触し、従動カム４１の凸部４１ａが駆動カム４０の凹部に接触している。
【００１５】
ここで、安全フレーム２０を起立状態から車体の後方へ倒回する場合は、図３の矢印（イ）に示すように、前記操作レバー３０を車体後方へ回転させる。然るときは、図６及び図７に示すように、操作レバー３０と一体に係止ロッド３２が回転し、前記駆動カム４０が軸周りに９０度回転して従動カム４１を押圧するため、前記ストッパ４２がコイルバネ４３を圧縮しながら係止ロッド３２は短縮する。従って、係止ロッド３２の大径部３２ｂが前記一方の位置決め孔３３から引き出されて小径部３２ａが該位置決め孔３３内に挿入され、安全フレーム２０のロックが解除される。このとき、前記操作レバー３０に突設したストッパピン３７ｂが前記「ヘ」字状のプレート３６の下端部に当接して操作レバー３０の回転を阻止し、且つ、駆動カムの凸部４０ａが従動カムの凸部４１ａに乗り上げて面取り部分同士が圧接されるので、駆動カム４０はアンロック状態に保持される。
【００１６】
斯かるアンロック状態で、図３の矢印（ロ）に示すように、前記安全フレーム２０を車体後方へ回動すれば、前記小径部３２ａが前記ブラケット２２Ｌの長孔３５内を移動しながら、前記揺動軸２３を中心に取付金具３１Ｌ，３１Ｒが回転して安全フレーム２０が後方へ倒回する。このとき、前記操作レバー３０のストッパピン３７ｂが前記プレート３６の下端部から内側面に当接して係止ロッド３２の回転が規制されるので、前記駆動カム４０に対して従動カム４１のみが回転し、従動カムの凸部４１ａが駆動カム４０の凹部に係合する。従って、コイルバネ４３の付勢により係止ロッド３２が伸張し、前記大径部３２ｂが前記ブラケット２２Ｌの他方の位置決め孔３４に嵌入する。斯くして、図８に示すように、係止ロッドの大径部３２ｂが他方の位置決め孔３４に嵌入して、安全フレーム２０が倒回状態にロックされる。
【００１７】
ここで、安全フレーム２０を倒回状態から起立する場合は、図８の矢印（ハ）に示すように、前記操作レバー３０を車体前方へ回転させる。然るときは、操作レバー３０と一体に係止ロッド３２が回転し、前記駆動カム４０が軸周りに前述とは逆方向へ９０度回転して従動カム４１を押圧するため、前記ストッパ４２がコイルバネ４３を圧縮しながら係止ロッド３２は短縮する。従って、係止ロッド３２の大径部３２ｂが前記他方の位置決め孔３４から引き出されて小径部３２ａが該位置決め孔３４内に挿入され、安全フレーム２０のロックが解除される。このとき、前記操作レバー３０に突設したストッパピン３７ａが前記「ヘ」字状のプレート３６の上端部に当接して操作レバー３０の回転を阻止し、且つ、駆動カムの凸部４０ａが従動カムの凸部４１ａに乗り上げて面取り部分同士が圧接されるので、駆動カム４０はアンロック状態に保持される。
【００１８】
斯かるアンロック状態で、図８の矢印（ニ）に示すように、前記安全フレーム２０を車体前方へ回動すれば、前記小径部３２ａが前記ブラケット２２Ｌの長孔３５内を移動しながら、前記揺動軸２３を中心に取付金具３１Ｌ，３１Ｒが回転して安全フレーム２０が前方へ起立する。このとき、前記操作レバー３０のストッパピン３７ａが前記プレート３６の上端部に当接して係止ロッド３２の回転が規制されるので、前記駆動カム４０に対して従動カム４１のみが回転し、従動カムの凸部４１ａが駆動カム４０の凹部に係合する。従って、コイルバネ４３の付勢により係止ロッド３２が伸張し、前記大径部３２ｂが前記ブラケット２２Ｌの一方の位置決め孔３４に嵌入する。斯くして、図３乃至図５に示すように、係止ロッドの大径部３２ｂが前記一方の位置決め孔３３に嵌入して、安全フレーム２０が起立状態にロックされる。
【００１９】
尚、前記位置決め孔３３，３４及び長孔３５は一方のブラケット２２Ｌにのみ設けられているが、特にこれに限定すべきではなく、他方のブラケット２２Ｒの外側板２２Ｒ₁にも位置決め孔３３，３４及び長孔３５を設け、前記大径部３２ｂの代わりに係止部３２ｃの先端部を位置決め孔３３，３４に抜き差し可能にしてもよい。
【００２０】
このように、係止ロッド３２の片側に操作レバー３０を設けて大径部３２ｂを位置決め孔３３または３４へ抜き差し可能にしてあるため、オペレータは車体の片側にて安全フレーム２０をロック状態若しくはアンロック状態にでき、また、ロック状態若しくはアンロック状態が保持できるので、片手の操作にて安全フレームを起立または倒回できる。
【００２１】
図９は他の実施の形態を示し、前述した実施の形態と同一構成部分には同一符号を付してその説明を省略するものとする。同図に於いて、左右双方のブラケット２２Ｌ，２２Ｒの外側板２２Ｌ₁，２２Ｌ₂に前述した位置決め孔３３，３４及び長孔３５を夫々対称的に設け、何れか一方のブラケット例えばブラケット２２Ｒの内側に操作レバー３０を設け、該操作レバー３０を左右方向に操作することにより係止ロッド３２をスライドさせて、係止ロッド３２の大径部３２ｂと係止部３２ｃを夫々左右の位置決め孔３３または３４へ抜き差し可能に形成してある。前述と同様に、該操作レバー３０の回転に連動してストッパピン３７ａ，３７ｂが「ヘ」字状のプレート３６に接離し、駆動カム４０と従動カム４１によって係止ロッド３２をロック位置またはアンロック位置に固定することができる。斯かる構成では、左右のブラケット２２Ｌ，２２Ｒが対称形であるため、外側板や内側板を同一部品にて共用化することができる。
【００２２】
図１０は上記構成の変形例を示し、図９に示した構成と異なる箇所は、前記係止ロッド３２が分割されており、左右夫々に小径部３２ａ，３２ａが設けられ、左右の小径部３２ａ，３２ａを連結パイプ３２ｄにて連結してある。そして、一方のブラケット２２Ｌのみに位置決め孔３３，３４及び長孔３５を設けて大径部３２ｂを抜き差し可能に形成する。前記小径部３２ａ，３２ａと連結パイプ３２ｄはピン３８，３８にて連結され、該ピン３８，３８の嵌合部分に若干のクリアランスを有しているため、このクリアランスにより前記ブラケット２２Ｌ，２２Ｒや取付金具３１Ｌ，３１Ｒの寸法誤差を吸収して、作動性の向上を図っている。
【００２３】
図１１は更に他の変形例を示し、図１０に示した構成と異なる箇所は、前記左右のブラケット２２Ｌ，２２Ｒの外側板２２Ｌ₁，２２Ｌ₂に開穿した位置決め孔３４の上部に切欠部３９を設け、該切欠部３９によって前記位置決め孔３４の上方を開放してある。該切欠部３９の幅は係止ロッド３２の大径部３２ｂよりも狭く、且つ、前記小径部３１ａが挿入できる寸法に形成されている。従って、前記取付金具３３Ｌ，３３Ｒに係止ロッド３２の各部材を組付けた状態で、前記小径部３１ａを切欠部３９から落し込むことにより、前記取付金具３３Ｌ，３３Ｒ及び係止ロッド３２をブラケット２２Ｌ，２２Ｒに装着できる。即ち、安全フレーム２０の上部部品をサブ組立てした後に下部フレーム２１，２１へ装着することができ、組立作業の効率を向上できる。
尚、本発明は、本発明の精神を逸脱しない限り種々の改変を為すことができ、そして、本発明が該改変されたものに及ぶことは当然である。
【００２４】
【発明の効果】
本発明は上記一実施の形態に詳述したように、安全フレーム２０の左右基端部３１Ｌ，３１Ｒと左右のブラケット２２Ｌ，２２Ｒとを係止ロッド３２にて貫通し、少なくとも一方のブラケット３１Ｌ（３１Ｒ）に位置決め孔３３，３４を設けるとともに車体の片側に操作部３０を設けて位置決めピン３２ｂを前記位置決め孔３３，３４に抜き差し可能にしたことにより、一箇所での操作にて安全フレーム２０のロックまたはアンロック操作を行いつつ、安全フレーム２０の起立倒回操作が可能となる。斯くして、安全フレーム２０の起立倒回操作が片手にて簡単に行うことが可能となった。
【図面の簡単な説明】
図は本発明の一実施の形態を示すものである。
【図１】トラクタの側面図。
【図２】安全フレーム取付装置の背面図。
【図３】安全フレーム取付装置の側面図。
【図４】安全フレーム取付装置の左側部分の図３Ａ−Ａ線に於ける断面図。
【図５】安全フレーム取付装置の右側部分の図３Ａ−Ａ線に於ける断面図。
【図６】安全フレーム取付装置の左側部分の作動状態を示す断面図。
【図７】安全フレーム取付装置の右側部分の作動状態を示す断面図。
【図８】安全フレーム取付装置の作動状態を示す側面図。
【図９】安全フレーム取付装置の他の実施の形態を示す背面図。
【図１０】図９の変形例を示す背面図。
【図１１】図１０の変形例を示す背面図。
【符号の説明】
１０トラクタ
２０安全フレーム
２２Ｌ，２２Ｒブラケット
３０操作レバー
３１Ｌ，３１Ｒ取付金具
３２係止ロッド
３２ａ小径部
３２ｂ大径部
３３，３４位置決め孔
３５長孔[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a safety frame for a work vehicle, and more particularly to a safety frame that can be turned upside down.
[0002]
[Prior art and problems to be solved by the invention]
Conventionally, this type of work vehicle having no cabin roof is provided with a safety frame to protect the operator when the vehicle falls. In general, brackets are fixed to the left and right sides of the driver's seat, and the left and right lower ends of a “gate” -shaped safety frame in front view are attached to each bracket. Since the height of the safety frame is higher than the seating posture of the operator, the safety frame may come into contact with a tree branch when the vehicle is running, or may collide with the barn entrance or ceiling when the vehicle is stored.
[0003]
For this reason, the lower end of the safety frame is pivotally attached to each bracket so that the safety frame can be turned upside down, and when performing normal work, the safety frame is in an upright state by inserting positioning pins into the lock positions of the left and right brackets. When the safety frame is turned over, the right and left positioning pins are pulled out from the lock position and unlocked. Alternatively, the left and right brackets are provided with levers, and the positioning pins are moved to the lock position or the unlock position by operating the respective levers. However, since the positioning pins are locked or unlocked separately on the left and right, the operation of raising and lowering the safety frame is complicated.
[0004]
Therefore, a technical problem to be solved in order to easily lock and unlock the safety frame arises in a work vehicle in which the safety frame is mounted so that it can be turned upside down. It aims at solving.
[0005]
[Means for Solving the Problems]
The present invention has been proposed in order to achieve the above object, and a safety frame (20) formed in a "gate" shape as viewed from the front of the vehicle body is erected on the rear side of the driver seat (17), and A work vehicle that rotatably connects the left and right base ends of the safety frame (20) to brackets (22L) and (22R) fixed to the vehicle body, and the left and right base ends of the safety frame (20). Mounting brackets (31L), (31R) and left and right brackets (22L), (22R) are provided through a single locking rod (32), and the locking rod (32) has a small diameter portion (32a). ) And a large-diameter portion (32b) provided in the vicinity of the left and right ends, and on the side surface of the bracket (22L) on the side where the large-diameter portion (32b) is provided, the large-diameter portion of the locking rod (32b) can be inserted and the rotation of the safety frame (20) is stopped. The locking positioning holes (33), (34) and the long hole (35) into which the small diameter portion (32a) of the locking rod can be inserted and the safety frame (20) is allowed to rotate A positioning hole is provided, and an operating lever (30) for moving the locking rod (32) to the left and right is provided on one side of the locking rod (32) to provide a large diameter portion (32b) of the locking rod (32). ) In the safety frame (20) of the work vehicle formed so as to be removable from the positioning holes (33), (34).
The operation lever (30) is fixed to the outer surface (22L ₁ ) of the bracket (22L) on one side of the locking rod (32) with a plate (36) having a “H” shape in side view. A stopper pin (37a, 37b) is provided in the large-diameter portion (32b) of the locking rod (32) in a vertically opposite direction, and the stopper pin (37a) is rotated by rotating the operation lever (30). 37b) is formed so as to be in contact with and away from the inner surface of the plate (36), and is cylindrically driven coaxially with the locking rod (32) in the vicinity of the other end of the locking rod (32). provided with a cam (40), fixedly mounted a hollow cylindrical driven cam (41) on the inner surface of the inner mounting plate (31R ₂₎ of the mounting bracket (31R), the cam slopes of the drive cam (40) Convex part (40a, 40a) at a position 180 degrees opposite to the cylinder A, convex portions with respect to (40a, 40a), comprises a recess drives out phase difference of 90 degrees,
On the other hand, the convex portion (41a) of the driven cam (41) has the convex portions (41a, 41a) that engage with a phase difference of 90 degrees when engaging with the concave portion of the drive cam (40). A locking portion (32c) integral with the drive cam (40) is rotatably inserted into the hollow portion of the driven cam (41), and a stopper (42) is fitted into the locking portion (32c). A coil spring (43) is interposed between the stopper (42) and the inner surface of the inner mounting plate (31R ₂ ) of the mounting bracket (31R), and the locking rod (32) is urged in the extending direction to be driven. The present invention provides a safety frame for a work vehicle configured such that the drive cam (40) is always pressed against the cam (41).
[0006]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a side surface of a tractor 10 as an example of a work vehicle. The tractor 10 has a pair of left and right front wheels 11 and 111 and rear wheels 12 and 12. A case 14 is provided, and a work machine 16 such as a rotary is connected to the rear part of the vehicle body by a link device 15. A driver's seat 17 is provided above the mission case 14 and a steering handle 18 is provided in front of the driver's seat 17 to steer the front wheels 11 and 11.
[0007]
A safety frame 20 is provided behind the driver seat 17. The safety frame 20 is formed of a square pipe or a round pipe in a “gate” shape when viewed from the front, and brackets 22L and 22R are fixed to the upper ends of the lower frames 21 and 21 that are erected on the left and right sides of the vehicle body, respectively. The left and right lower ends of the safety frame 20 are pivotally attached to the brackets 22L and 22R by swinging shafts 23 and 23, respectively. The safety frame 20 can be pivoted back and forth around swinging shafts 23, 23 made of bolts. As will be described later, the safety frame 20 is locked in an upright state by an operation lever 30, or the operation lever The safety frame 20 is unlocked at 30 so that it can be turned backward.
[0008]
As shown in FIG. 2, mounting brackets 31L and 31R are welded to the left and right lower ends of the safety frame 20, and the mounting brackets 31L and 31R are respectively connected to the outer mounting plates 31L ₁ and 31R ₁ and the inner mounting plate 31L _2. , 31R ₂ are opposed to each other and are formed in a “U” shape with a rear opening in plan view. On the other hand, the brackets 22L and 22R are formed in a “U” shape with an upper opening in front view, with the outer plates 22L ₁ and 22R ₁ and the inner plates 22L ₂ and 22R ₂ facing the upper surfaces of the bottom plates 22L ₀ and 22R _0. Has been.
[0009]
Then, the outer mounting plate 31L ₁ and the inner mounting plate 31L ₂ of the left mounting bracket 31L are housed inside the outer plate 22L ₁ and the inner plate 22L ₂ of the left bracket 22L, and the left mounting bracket 31L and the left bracket 22L. The left mounting bracket 31L rotates back and forth around the swing shaft 23 by inserting the swing shaft 23 through the shaft. Similarly, the outer plate 22R ₁ and the outer mounting plate 31R ₁ inside the right mounting bracket 31R of the inner plate 22R ₂ and the inner mounting plate 31R ₂ of the right bracket 22R is housed, the right mounting member 31R and the right By passing the swinging shaft 23 through the bracket 22R, the right mounting bracket 31R rotates back and forth around the swinging shaft 23. Therefore, the safety frame 20 can stand up and down around the left and right brackets 22L and 22R.
[0010]
The mounting brackets 31L and 31R welded to the left and right lower ends of the safety frame 20 and the left and right brackets 22L and 22R are penetrated by a locking rod 32 that is slidable in the left and right direction, and at least one bracket 22L or 22R is inserted. A lock position for fixing the rotation of the safety frame 20 and an unlock position for allowing the rotation of the safety frame 20 are provided. The locking rod 32 has a small-diameter portion 32a at the central portion and a large-diameter portion 32b at at least one end.
[0011]
In this embodiment, as shown in FIGS. 3 and 4, a large-diameter portion 32b is provided in the vicinity of the left end portion of the locking rod 32, and the inner plate of the left bracket 22L provided with the large-diameter portion 32b. to 22L _2, the positioning hole 33 secure the frame 20 to stop the rotation of the large diameter portion 32b can be inserted and securely frame 20 when the upright position as well as perforated in the safety frame 20 is at a倒回state A positioning hole 34 for opening the large diameter portion 32b and stopping the rotation of the safety frame 20 is opened. That is, the large diameter portion 32b acts as a positioning pin that can be fitted into the positioning holes 33 and 34. Further, an arc-shaped long hole 35 is opened on the circumference connecting the center points of the positioning holes 33 and 34 with the swing shaft 23 as the center, and the positioning holes 33 and 34 are communicated with each other. The width of the long hole 35 is narrower than that of the large-diameter portion 32b, and is formed so as to allow the small-diameter portion 32a to be inserted. As will be described later, the positioning holes 33 and 34 serve as lock positions for stopping the rotation of the safety frame 20, and the long holes 35 serve as unlock positions that permit the rotation of the safety frame 20.
[0012]
Then, the locking operation lever 30 is an operation portion on one side of the rod 32 is provided, as well as fixed side view "f" shaped plate 36 to the outer surface of the outer plates 22L ₁ of the bracket 22L, the locking When the stopper pins 37a and 37b are projected in the opposite directions in the large-diameter portion 32b of the rod, and the operation lever 30 is rotated, the stopper pins 37a or 37b come into contact with or separate from the inner surface of the plate 36. To form. In the illustrated state, the large diameter portion 32b of the locking rod is fitted into one positioning hole 33, and the safety frame 20 is locked in the standing state.
[0013]
As shown in FIG. 5, the right side of the locking rod 32 to drive cam 40 to the engaging rod 32 coaxially provided in the vicinity of the end portion, said mounting bracket 31R on the inner surface of the inner mounting plate 31R ₂ hollow cylindrical The driven cam 41 is fixed. The cam slope of the drive cam 40 has convex portions 40a and 40a at positions opposed to the cylinder by 180 degrees, and has concave portions with a phase difference of 90 degrees with respect to the convex portions 40a and 40a. The portions 40a, 40a are chamfered flat in the rotation direction of the locking rod 32. On the other hand, the driven cam 41 is formed with a phase difference of 90 degrees with respect to the drive cam 40, and each convex portion 41a, 41a is flat chamfered, and the hollow portion of the drive cam 41 is formed in the hollow portion of the driven cam 41. A locking portion 32c integral with the drive cam 40 is rotatably inserted.
[0014]
The engagement in the retaining portion 32c stopper 42 is fitted, by interposing a coil spring 43 between the stopper 42 and the mounting bracket 31R of the inner mounting plate 31R ₂ of the inner surface, in a direction extending locking rod 32 Energized. In other words, the drive cam 40 is always in pressure contact with the driven cam 41, and in the figure, the convex portion 40a of the drive cam 40 contacts the concave portion of the driven cam 41, and the convex portion 41a of the driven cam 41 is in contact with the drive cam 40. It is in contact with the recess.
[0015]
Here, when the safety frame 20 is turned backward from the standing state to the rear of the vehicle body, the operation lever 30 is rotated to the rear of the vehicle body as shown by an arrow (A) in FIG. At that time, as shown in FIGS. 6 and 7, the locking rod 32 rotates integrally with the operation lever 30, and the drive cam 40 rotates 90 degrees around the axis to press the driven cam 41. The locking rod 32 is shortened while the stopper 42 compresses the coil spring 43. Accordingly, the large diameter portion 32b of the locking rod 32 is pulled out from the one positioning hole 33, the small diameter portion 32a is inserted into the positioning hole 33, and the lock of the safety frame 20 is released. At this time, the stopper pin 37b projecting from the operation lever 30 abuts against the lower end portion of the "H" -shaped plate 36 to prevent the operation lever 30 from rotating, and the convex portion 40a of the drive cam is driven. Since the chamfered portions ride on the convex portion 41a of the cam and are pressed against each other, the drive cam 40 is held in the unlocked state.
[0016]
In such an unlocked state, as shown by the arrow (b) in FIG. 3, if the safety frame 20 is rotated to the rear of the vehicle body, the small diameter portion 32a moves in the long hole 35 of the bracket 22L, The mounting brackets 31L and 31R rotate around the swing shaft 23, and the safety frame 20 is turned backward. At this time, since the stopper pin 37b of the operation lever 30 contacts the inner surface from the lower end of the plate 36, the rotation of the locking rod 32 is restricted, so that only the driven cam 41 rotates with respect to the drive cam 40. Then, the convex portion 41 a of the driven cam engages with the concave portion of the drive cam 40. Therefore, the locking rod 32 is extended by the bias of the coil spring 43, and the large diameter portion 32b is fitted into the other positioning hole 34 of the bracket 22L. Thus, as shown in FIG. 8, the large-diameter portion 32b of the locking rod is fitted into the other positioning hole 34, and the safety frame 20 is locked in the inverted state.
[0017]
Here, when the safety frame 20 is raised from the inverted state, the operation lever 30 is rotated forward of the vehicle body as indicated by an arrow (c) in FIG. At that time, the locking rod 32 rotates integrally with the operation lever 30, and the driving cam 40 rotates 90 degrees around the axis in the opposite direction to press the driven cam 41. The locking rod 32 is shortened while compressing the coil spring 43. Accordingly, the large diameter portion 32b of the locking rod 32 is pulled out from the other positioning hole 34, the small diameter portion 32a is inserted into the positioning hole 34, and the safety frame 20 is unlocked. At this time, the stopper pin 37a projecting from the operation lever 30 abuts on the upper end portion of the "H" -shaped plate 36 to prevent the operation lever 30 from rotating, and the convex portion 40a of the drive cam is driven. Since the chamfered portions ride on the convex portion 41a of the cam and are pressed against each other, the drive cam 40 is held in the unlocked state.
[0018]
In such an unlocked state, as shown by the arrow (d) in FIG. 8, if the safety frame 20 is rotated forward of the vehicle body, the small diameter portion 32a moves in the long hole 35 of the bracket 22L, The mounting brackets 31L and 31R rotate around the swing shaft 23, and the safety frame 20 stands up forward. At this time, the stopper pin 37a of the operation lever 30 abuts on the upper end of the plate 36 and the rotation of the locking rod 32 is restricted, so that only the driven cam 41 rotates relative to the drive cam 40, and the driven The convex portion 41 a of the cam engages with the concave portion of the drive cam 40. Therefore, the locking rod 32 is extended by the urging of the coil spring 43, and the large diameter portion 32b is fitted into one positioning hole 34 of the bracket 22L. Thus, as shown in FIGS. 3 to 5, the large-diameter portion 32b of the locking rod is fitted into the one positioning hole 33, and the safety frame 20 is locked in the standing state.
[0019]
Incidentally, the positioning hole 33, 34 and the long hole 35 is provided only on one of the bracket 22L, not particularly to be limited to this, also positioned outside plate 22R ₁ of the other bracket 22R holes 33, 34 In addition, a long hole 35 may be provided so that the distal end portion of the locking portion 32c can be inserted into and removed from the positioning holes 33 and 34 instead of the large diameter portion 32b.
[0020]
As described above, the operating lever 30 is provided on one side of the locking rod 32 so that the large diameter portion 32b can be inserted into and removed from the positioning hole 33 or 34, so that the operator can lock the safety frame 20 on one side of the vehicle body or unlock it. Since the locked state can be maintained and the locked state or the unlocked state can be maintained, the safety frame can be erected or turned over by one-handed operation.
[0021]
FIG. 9 shows another embodiment, and the same components as those of the above-described embodiment are denoted by the same reference numerals and the description thereof is omitted. In the drawing, the positioning holes 33 and 34 and the long holes 35 described above are provided symmetrically in the outer plates 22L ₁ and 22L ₂ of the left and right brackets 22L and 22R, respectively, and either one of the brackets, for example, the inner side of the bracket 22R is provided. The operating lever 30 is provided in the left and right, and the locking rod 32 is slid by operating the operating lever 30 in the left-right direction, so that the large-diameter portion 32b and the locking portion 32c of the locking rod 32 are moved to the left and right positioning holes 33 or 34 is formed to be removable. In the same manner as described above, the stopper pins 37a and 37b are brought into contact with and separated from the "H" -shaped plate 36 in conjunction with the rotation of the operation lever 30, and the locking rod 32 is locked or unlocked by the driving cam 40 and the driven cam 41. It can be fixed in the locked position. In such a configuration, since the left and right brackets 22L and 22R are symmetrical, the outer plate and the inner plate can be shared by the same component.
[0022]
FIG. 10 shows a modified example of the above-described configuration. The difference from the configuration shown in FIG. 9 is that the locking rod 32 is divided, small diameter portions 32a and 32a are provided on the left and right sides, and the left and right small diameter portions 32a. , 32a are connected by a connecting pipe 32d. Then, the positioning holes 33 and 34 and the long hole 35 are provided only in one bracket 22L so that the large diameter portion 32b can be inserted and removed. The small-diameter portions 32a, 32a and the connecting pipe 32d are connected by pins 38, 38, and the fitting portions of the pins 38, 38 have a slight clearance. Absorbing the dimensional error of the metal fittings 31L, 31R, the operability is improved.
[0023]
FIG. 11 shows still another modified example, and a different point from the configuration shown in FIG. 10 is that a notch 39 is formed above the positioning hole 34 opened in the outer plates 22L ₁ and 22L ₂ of the left and right brackets 22L and 22R. And the upper portion of the positioning hole 34 is opened by the notch 39. The width of the notch 39 is narrower than the large diameter portion 32b of the locking rod 32, and is formed to have a size that allows the small diameter portion 31a to be inserted. Accordingly, the mounting brackets 33L and 33R and the locking rod 32 are bracketed by dropping the small diameter portion 31a from the notch 39 in a state where the members of the locking rod 32 are assembled to the mounting brackets 33L and 33R. Can be attached to 22L and 22R. That is, after the upper parts of the safety frame 20 are sub-assembled, they can be mounted on the lower frames 21 and 21, thereby improving the efficiency of the assembly work.
It should be noted that the present invention can be variously modified without departing from the spirit of the present invention, and the present invention naturally extends to the modified ones.
[0024]
【The invention's effect】
As described in detail in the above embodiment, the present invention penetrates the left and right base end portions 31L, 31R of the safety frame 20 and the left and right brackets 22L, 22R with the locking rod 32, and at least one bracket 31L ( 31R) is provided with positioning holes 33 and 34, and an operating portion 30 is provided on one side of the vehicle body so that the positioning pin 32b can be inserted into and removed from the positioning holes 33 and 34, so that the safety frame 20 can be operated at a single location. While performing the lock or unlock operation, the safety frame 20 can be turned upside down. Thus, the standing and turning operation of the safety frame 20 can be easily performed with one hand.
[Brief description of the drawings]
The figure shows an embodiment of the present invention.
FIG. 1 is a side view of a tractor.
FIG. 2 is a rear view of the safety frame mounting device.
FIG. 3 is a side view of the safety frame mounting device.
4 is a cross-sectional view taken along the line 3A-A of the left side portion of the safety frame mounting device. FIG.
5 is a cross-sectional view taken along the line 3A-A of the right side portion of the safety frame mounting device. FIG.
FIG. 6 is a cross-sectional view showing the operating state of the left side portion of the safety frame mounting device.
FIG. 7 is a cross-sectional view showing the operating state of the right side portion of the safety frame mounting device.
FIG. 8 is a side view showing an operating state of the safety frame mounting device.
FIG. 9 is a rear view showing another embodiment of the safety frame mounting device.
10 is a rear view showing a modified example of FIG. 9;
11 is a rear view showing a modification of FIG.
[Explanation of symbols]
10 Tractor 20 Safety frame 22L, 22R Bracket 30 Operation lever 31L, 31R Mounting bracket 32 Locking rod 32a Small diameter part 32b Large diameter part 33, 34 Positioning hole 35 Long hole

Claims

A safety frame (20) formed in a “gate” shape as viewed from the front of the vehicle body is erected on the rear side of the driver seat (17), and left and right base end portions of the safety frame (20) are fixed to the vehicle body. A work vehicle that is pivotably connected to brackets (22L) and (22R), and mounting brackets (31L) and (31R) at left and right base ends of the safety frame (20) and left and right brackets (22L), (22R) is provided through a single locking rod (32), and the locking rod (32) has a small diameter portion (32a) and a large diameter portion (32b) provided in the vicinity of the left and right ends. The large-diameter portion (32b) of the locking rod can be inserted into the side surface of the bracket (22L) on the side where the large-diameter portion (32b) is provided, and the safety frame (20) can be rotated. The locking positioning holes (33), (34) to be stopped, And an unlocking positioning hole comprising a long hole (35) that allows the small-diameter portion (32a) of the door to be inserted and allows the safety frame (20) to rotate, and is further provided on one side of the locking rod (32). An operating lever (30) for moving the locking rod (32) to the left and right is provided so that the large diameter portion (32b) of the locking rod (32) can be inserted into and removed from the positioning holes (33) and (34). In the safety frame (20) of the work vehicle
The operation lever (30) is fixed to the outer surface (22L ₁ ) of the bracket (22L) on one side of the locking rod (32) with a plate (36) having a “H” shape in side view. A stopper pin (37a, 37b) is provided in the large-diameter portion (32b) of the locking rod (32) in a vertically opposite direction, and the stopper pin (37a) is rotated by rotating the operation lever (30). 37b) is formed so as to be in contact with and away from the inner surface of the plate (36), and is cylindrically driven coaxially with the locking rod (32) in the vicinity of the other end of the locking rod (32). provided with a cam (40), fixedly mounted a hollow cylindrical driven cam (41) on the inner surface of the inner mounting plate (31R ₂₎ of the mounting bracket (31R), the cam slopes of the drive cam (40) Convex part (40a, 40a) at a position 180 degrees opposite to the cylinder A, convex portions with respect to (40a, 40a), comprises a recess drives out phase difference of 90 degrees,
On the other hand, the convex portion (41a) of the driven cam (41) has the convex portions (41a, 41a) that engage with a phase difference of 90 degrees when engaging with the concave portion of the drive cam (40). A locking portion (32c) integral with the drive cam (40) is rotatably inserted into the hollow portion of the driven cam (41), and a stopper (42) is fitted into the locking portion (32c). A coil spring (43) is interposed between the stopper (42) and the inner surface of the inner mounting plate (31R ₂ ) of the mounting bracket (31R), and the locking rod (32) is urged in the extending direction to be driven. A safety frame for a work vehicle, characterized in that the drive cam (40) is always pressed against the cam (41).