JP4167938B2

JP4167938B2 - Portable power brush cutter

Info

Publication number: JP4167938B2
Application number: JP2003146156A
Authority: JP
Inventors: 策次山田
Original assignee: Individual
Current assignee: Individual
Priority date: 2003-05-23
Filing date: 2003-05-23
Publication date: 2008-10-22
Anticipated expiration: 2023-05-23
Also published as: JP2004344094A

Description

【０００１】
【発明の属する技術分野】
本願発明は、地表に生育する雑草等の草木をその根元付近から刈払う作業に用いる携帯式動力刈払機に関する。
【０００２】
【従来の技術】
この種の携帯式動力刈払機は、操作管の先端部に回転作業体を備え、動力源の回転出力を操作管内に通挿した伝動軸を介して回転作業体に伝達し、これを回転させるように構成されている。動力源は、たとえば小型ガソリンエンジンが採用され、一般的には操作管の基端部に連結されている。操作管には、グリップハンドルが装備される場合もある。
【０００３】
回転作業体は、たとえば金属円板の外周に鋸刃のような刃が設けられた回転刃が採用される。たとえば、特許文献１に示されているように、通常、この回転刃の回転軸は、操作管の軸線に対して交差させられる。これは、作業中、回転刃ができるだけ刈払い作業の対象となる地表と平行となるようにするためである。
【０００４】
刈払い作業は、機体を保持した作業者が、上記の操作管を振回操作して、回転刃を地表に沿って移動させることにより行う。
【０００５】
ところで、刈払い作業の対象となる地表は、かならずしも平坦となっているとは限らず、爪先上がり、あるいは爪先下がりの傾斜となっている場合もある。このような場合、操作管の軸線に対する回転刃の回転軸の交差角度を固定してしまうと、回転刃を地表と平行とするために、操作管の基端方を高く持ち上げたり、また、低い位置をとらせたりする必要があり、作業が非常にしづらくなる。また、平坦な地表の刈払い作業をする場合であっても、背丈のある作業者は、操作管の基端を低く保持し、逆に背丈のない作業者は、操作管の基端を高く持ち上げねばならず、作業がしづらくなる。操作管の基端にエンジンが直結されている場合には、エンジンの重さがあるので、上記のような作業のしづらさは、なおさらとなる。
【０００６】
そこで、従来、たとえば特許文献２に示されているもののように、操作管の軸線に対する回転刃の回転軸の角度を調整可能とすることにより、対象となる地表の傾斜に応じて、あるいは作業者の背丈に応じて、操作管の基端部を作業者にとって楽な高さに保持しつつ、回転刃に地表と平行な姿勢をとらせることができるようにしたものがある。
【０００７】
【特許文献１】
特開昭６３−５６２１４号公報
【特許文献２】
実公平３−１７６１９号公報
【０００８】
【発明が解決しようとする課題】
上記特許文献２に示された構成は、操作管の先端に斜め下方に延びる支持杆を設け、この支持杆に回転刃を前後揺動可能に取り付ける一方、伝動軸として、フレキシブルチューブの内部に可撓性のある伝動軸を挿通したものを用い、操作手段によって操作管と伝動軸とを相対移動させることにより、回転刃の角度を調整できるようにしている。
【０００９】
しかしながら、上記の構成においては、操作管の先端から下方に大きく離れた位置において比較的重量のある回転刃が支持されているため、操作管を左右方向に振回する場合に慣性力の影響を受けて操作管が軸転してしまい、そのために回転刃が左右に揺動してしまうという問題がある。すなわち、操作管の振回操作をする場合、回転刃が不安定に揺動してしまうのであり、このことは、作業性の悪化につながる。
【００１０】
また、上記の構成においては、操作管の先端部から回転刃までの寸法が比較的大きくなるため、地表から離れた位置に障害物が存在するような状況では、非常に刈払い作業がしづらくなるという問題もある。
【００１１】
加えて、操作管の先端部の重量が大きくなるため、振回操作がしづらいという問題もある。
【００１２】
さらには、操作管から回転刃までの動力の伝達は、あくまでも、フレキシブルチューブの内部に可撓性のある伝動軸を通挿した構成を採用している。このようなフレキシブルチューブは、高速軸転する伝動軸を内部に通挿保持する部材であり、しかも、所定の引っ張り力、圧迫力にも耐えることが必要な部材であることから、その屈曲抵抗は、比較的大きい。したがって、上記構成においては、このような大きな屈曲抵抗を有するフレキシブルチューブと伝動軸との二重構成のものを強制的に屈曲変形させることによって回転刃の角度を変更するようにしているため、回転刃の角度変更には上記した大きな屈曲抵抗に抗する操作力が必要である。このように、上記特許文献２に記載された上記構成の携帯式刈払機では、決して回転刃の角度変更を軽快に行なうことができるとはいえなかった。
【００１３】
本願発明は、上記した事情のもとで考え出されたものであって、操作管の先端部の重量増加や大型化を招くことなく、操作管の軸線に対する回転刃の角度姿勢をより軽快かつ簡便に変更できるようにすることをその課題としている。
【００１４】
【発明の開示】
上記の課題を解決するため、本願発明では、次の技術的手段を採用した。
【００１５】
すなわち、本願発明の第１の側面によって提供される携帯式動力刈払機は、操作管と、この操作管に通挿された伝動軸と、操作管の先端部に設けられた回転刃支持部材を介して支持された回転刃とを備え、動力源の回転出力を上記伝動軸を介して上記回転刃に伝達し、この回転刃を回転させるように構成された携帯式動力刈払機であって、上記回転刃支持部材は、上記伝動軸の先端が連結される入力軸と、この入力軸とベベルギア機構を介して連携された回転刃取付け軸とを備えており、上記操作管の先端には、連結第１部材が設けられているとともに、上記回転刃支持部材には、連結第２部材が設けられており、これら連結第１部材と連結第２部材とが、ほぼ上記操作管の軸線と直交する横方向軸周りに所定の抵抗をもって回動可能に連結されており、かつ、これら連結第１部材と連結第２部材には、それぞれ上記伝動軸が貫通状に通挿される伝導軸挿通孔が形成されており、上記連結第１部材と上記連結第２部材の一方には、上記伝動軸を挟んで対向する一対の第１連結壁が形成されているとともに、上記連結第１部材と上記連結第２部材の他方には、上記一対の第１連結壁の外面に接する一対の第２連結壁が形成されており、伝動軸を挟んで位置する各第１連結壁と第２連結壁とは、それらの厚み方向に連通挿され、かつ上記横方向軸に相当するねじ部材によりそれぞれ連結されており、かつ、上記伝動軸は、少なくとも上記操作管の先端部から上記回転刃支持部材に至る部位が可撓性を備えていることを特徴としている。
【００１７】
好ましい実施の形態においてはまた、上記連結第１部材および連結第２部材にそれぞれ形成された伝動軸挿通孔は、上記横方向軸に近づくほど概して上下幅が拡大するテーパ状となっている。
【００１９】
好ましい実施の形態においてはまた、上記ねじ部材は、上記第２連結壁に開けた孔内に位置する軸部と、この軸部の先端側に形成され、上記第１連結壁に開けたねじ穴に螺合するとともに上記軸部よりも小径の雄ねじ部と、上記軸部の基端側に形成された頭部とを備えており、上記軸部の先端面が上記第１連結壁の外面に当接するまで上記雄ねじ部が上記ねじ穴に螺合された状態で、上記頭部と上記第２連結壁の外面との間にばね部材が介装されている。
【００２０】
この本願発明の第１の側面に係る携帯式動力刈払機は、操作管の先端部に対し、回転刃支持部材が、ほぼ操作管の軸線と直交する横方向軸周りに所定の抵抗をもって回動可能に支持されている。そして、操作管の先端部から回転刃支持部材に至る伝動軸は、可撓性を有しているので、上記のように回転刃支持部材が操作管に対して上記横方向軸を中心として回動することを伝動軸が阻害することはない。そして、回転刃支持部材は、操作管に対して、所定の抵抗をもって回動可能に支持されているので、回転刃支持部材は外力の作用する方向に回動し、回動後の姿勢は上記の抵抗によって保持される。
【００２１】
実際の使用にあたっては、作業者は、回転刃の角度姿勢を変更する必要が生じたとき、いったん回転刃の回転を停止させた状態で、回転刃の適部で地面を叩くようにする。たとえば、回転刃の先端方で地面を叩くようにしたり、回転刃の基端方で地面を叩くようにしたりすることにより、操作管の軸線に対する回転刃の上記横方向軸周りの角度姿勢を所望のように調整することができる。回転刃の適部で地面を叩くようにすることは、操作管を上下方向に振るといった、刈払い作業に準じた操作管の取り扱いによって行なうことができる。このように、上記構成の携帯式動力刈払機においては、特別な操作部材を操作する必要なく、簡便に回転刃の角度姿勢を変更することができる。
【００２２】
本願発明の第２の側面によって提供される携帯式動力刈払機は、操作管と、この操作管に通挿された伝動軸と、操作管の先端部に設けられた回転刃支持部材を介して支持された回転刃とを備え、動力源の回転出力を上記伝動軸を介して上記回転刃に伝達し、この回転刃を回転させるように構成された携帯式動力刈払機であって、上記回転刃支持部材は、上記伝動軸の先端が連結される入力軸と、この入力軸とベベルギア機構を介して連携された回転刃取付け軸とを備え、操作管の先端部において、ほぼ上記操作管の軸線と直交する横方向軸周りに段階係止可能に回動するようにして上記操作管に対して支持されており、上記操作管の先端には、連結第１部材が設けられているとともに、上記回転刃支持部材には、連結第２部材が設けられており、これら連結第１部材と連結第２部材とが、上記横方向軸周りに回動可能に連結されており、かつ、これら連結第１部材と連結第２部材には、それぞれ上記伝動軸が貫通状に通挿される伝導軸挿通孔が形成されており、上記連結第１部材と上記連結第２部材の一方には、上記伝動軸を挟んで対向する一対の第１連結壁が形成されているとともに、上記連結第１部材と上記連結第２部材の他方には、上記一対の第１連結壁の外面に接する一対の第２連結壁が形成されており、伝動軸を挟んで位置する各第１連結壁と第２連結壁とは、それらの厚み方向に連通挿され、かつ上記横方向軸に相当するねじ部材によりそれぞれ連結されており、かつ、上記伝動軸は、少なくとも上記操作管の先端部から上記回転刃支持部材に至る部位が可撓性を備えていることを特徴としている。
【００２４】
好ましい実施の形態においてはまた、上記連結第１部材および連結第２部材にそれぞれ形成された伝動軸挿通孔は、上記横方向軸に近づくほど概して上下幅が拡大するテーパ状となっている。
【００２６】
好ましい実施の形態においてはまた、上記連結第１部材ないしこれと一体的な部材と上記連結第２部材ないしこれと一体的な部材との間には、上記連結第１部材ないしこれと一体的な部材に対する上記連結第２部材ないしこれと一体的な部材の上記横方向軸を中心とした回動時、所定回動角度ごとに係止しうる段階係止機構が設けられている。
【００２７】
好ましい実施の形態においては、上記段階係止機構は、上記連結第１部材ないしこれと一体的な部材と上記連結第２部材ないしこれと一体的な部材の一方に、上記横方向軸を中心とした円弧に沿って複数の係合凹部を形成する一方、上記連結第１部材ないしこれと一体的な部材と上記連結第２部材ないしこれと一体的な部材の他方に、上記係合凹部が形成された面に向けて弾力付勢した係合部材を設けることによって形成されている。
【００２８】
他の好ましい実施の形態において、上記段階係止機構は、上記連結第１部材ないしこれと一体的な部材と上記連結第２部材ないしこれと一体的な部材の一方に、上記横方向軸を中心とした円弧に沿って複数の係合凹部を形成する一方、上記連結第１部材ないしこれと一体的な部材と上記連結第２部材ないしこれと一体的な部材の他方に、上記係合凹部が形成された面に向けて付勢した係合部材を設けるとともに、この係合部材は、作業者の操作により、付勢力に抗して強制的に上記係合凹部から退避させることができるように構成されている。
【００２９】
この本願発明の第２の側面に係る携帯式動力刈払機は、上記第１の側面に係る携帯式動力刈払機においては、操作管に対して回転刃支持部材が横方向軸周りに所定の抵抗をもって回動可能に支持されていたのに対し、操作管に対して回転刃支持部材が横方向軸周りに段階係止可能に回動しうるようにしている点が異なる。
【００３０】
好ましい実施の形態においてこのように段階係止可能とするための手段は、複数の凹部に係合部材が節度感をもって係入するようにした構成がとられる。この場合においても、回転刃支持部材は、外力によって横方向軸周りに回動するが、その角度姿勢は、上記複数の凹部と係合部材との係合によって規定されるあらかじめ定められたものとなる。したがって、変更後の角度姿勢がより安定するとともに、所望の角度姿勢を比較的容易に再現することができるようになる。
【００３１】
また、他の好ましい実施の形態において上記のように段階係止可能とするための手段は、複数の凹部に係合部材が付勢力によって係入するようにするとともに、係合部材は作業者の操作によって強制的に上記付勢力に抗して退避させることができる構成がとられる。この場合、係合部材を強制退避させた状態では、回転刃支持部材を操作管に対して上記横方向軸周りにフリーに回動するようにすることもできる。そして、地面を使うなどして操作管に対する回転刃の大まかな姿勢を得た状態で係合部材を強制退避させていた操作力を解除すると、付勢力によって係合部材がいずれかの凹部に自動的に係合し、最終的に回転刃の姿勢が決まる。このように、本願発明の第２の側面に係る携帯式動力刈払機によっても、回転刃の角度姿勢の変更を軽快かつ容易に行なうことができる。
【００３２】
本願発明のその他の特徴および利点は、図面を参照して以下に行なう詳細な説明から、より明らかとなろう。
【００３３】
【発明の実施の形態】
以下、本願発明の好ましい実施の形態につき、図面を参照して具体的に説明する。
【００３４】
図１〜図５は、本願発明の第１の実施形態に係る携帯式動力刈払機１を示している。図１に示されているように、この刈払機１は、操作管１０と、この操作管１０の基端に連結された小型エンジン２０と、操作管１０の先端部に支持された回転刃３１とを備えて基本的に構成され、小型エンジン２０の回転出力は、操作管１０の内部に通挿された伝動軸４０を介して回転刃３１に伝達されるようになっている。
【００３５】
操作管１０は、アルミニウム等の軽量金属パイプによって形成され、図２によく表れているように、その基端部には、クラッチハウジング１１が一体的に取付けられている。このクラッチハウジング１１は、エンジン２０の本体に連結され、これにより、操作管１０の基端部がエンジン２０に連結される。クラッチハウジング１１の内部には、クラッチドラム１２が回転可能に軸支されており、このクラッチドラム１２の軸１３には、伝動軸４０の基端が連結されている。クラッチドラム１２は、エンジン側のクラッチシュー（図示略）と協働して遠心クラッチを形成している。図示しないスロットルレバーを操作することによってエンジン２０の回転数を上げると、遠心クラッチがエンジン２０の回転出力をクラッチドラム１２に伝え、伝動軸４０を回転させる。
【００３６】
操作管１０の先端部には、回転刃支持部材３０が設けられる。この回転刃支持部材３０は、図３に良く表れているように、上記の伝動軸４０の先端部が連結される入力軸３２と、この入力軸３２に対してベベルギア機構を介して連携された回転刃取付け軸３３とがハウジング３５内に収容された構成を備えている。すなわち、上記入力軸３２は、その先端に第１ベベルギア３４を備え、上記ハウジング３５の基端側筒部３５Ａ内において、ベアリング３６を介して回転可能に支持されている一方、上記回転刃取付け軸３３は、その基端側に上記第１ベベルギア３４と噛み合う第２ベベルギア３７を備え、上記ハウジング３５の先端側筒部３５Ｂ内において、ベアリング３８を介して回転可能に支持されている。すなわち、この回転刃支持部材３０においては、入力軸３２と回転刃取付け軸３３とが１２０度程度の角度で交差するように、回転動力伝達軸の方向が変換されている。回転刃取付け軸３３の先端には、回転刃３１が取付けられる。この回転刃３１は、たとえば、金属円板の外周に鋸刃を直接形成したもの、あるいは超鋼チップ刃を取付けたものなどが好適に用いられる。
【００３７】
なお、操作管１０の基端方には、横方向に延びるグリップハンドル１７が適当なブラケット１８を介して取り付けられている。また、この操作管１０の適所には、エンジン２０の回転数を制御するための図示しないスロットルレバーが取り付けられる。
【００３８】
上記回転刃支持部材３０は、上記操作管１０の先端部に対して、横方向軸１４周りに回動可能に連結される。本願発明において、この横方向軸１４は、操作管１０の軸線とほぼ直交するようにされる。換言すると、この横方向軸１４は、操作管１０の軸線と交差するか、または、操作管１０の軸線に対して上下方向にそれほど離れていない。
【００３９】
より詳しくは、操作管１０の先端部には、連結第１部材６が一体的に取り付けられる一方、回転刃支持部材３０のハウジング３５の基端側筒部３５Ａには、連結第２部材７が一体的に取り付けられ、これら、連結第１部材６と連結第２部材７とが、上記横方向軸１４を中心として、所定の抵抗力をもって、相互に回動可能に連結される。
【００４０】
上記連結第１部材６は、図３〜５に表れているように、操作管１０の内部に嵌入される筒部６１と、この筒部６１の先端側に延出し、かつ側面視略円形をした左右一対の第１連結壁６２，６２と、操作管１０に外嵌される外套部６３とを備えている。上記一対の第１連結壁６２，６２は、その間に伝動軸４０が配置されるに十分な間隔を隔てて対向させられている。そして、一対の第１連結壁６２，６２の上下部は、上記外套部６３につながる橋絡部６４によって互いに連結されており、したがって、一対の第１連結壁６２，６２間の間隔が不用意に縮小されるということはない。この連結第１部材６の上記筒部６１には、伝導軸挿通孔６１ａが軸方向に貫通形成されており、この伝導軸挿通孔６１ａは、その上下幅が筒部６１の先端側に向かうほど拡大するテーパ状とされている。外套部６３の先端部には、後記する連結第２部材７の適部に当接して連結第２部材７の上記横方向軸１４周りの回動範囲を規定するためのストッパ部６３ａが形成されている。
【００４１】
上記連結第２部材７は、図３〜５に表れているように、回転刃支持部材３０の基端側筒部３５Ａに嵌入される筒部７１を有しており、この筒部７１の後端側延出部７１ｂには、上記連結第１部材６の一対の第１連結壁６２，６２の外面に接し、かつ側面視略円形をした左右一対の第２連結壁７２，７２が形成されている。上記延出部７１ｂにはまた、一対の第２連結壁７２，７２の外周にそって延出し、上記連結第１部材６のストッパ部６３ａと協働して連結第２部材７の回動範囲を規定するストッパ部７３ａが設けられているが、このストッパ部７３ａと上記一対の第２連結壁７２，７２は、互いに分離状態にある。この連結第２部材７の上記筒部７１ないし延出部７１ｂには、伝動軸挿通孔７１ａが軸方向に貫通形成されており、この伝動軸挿通孔７１ａは、その上下幅が上記連結第１部材６側に向かうほど拡大するテーパ状とされている。
【００４２】
図５に良く表れているように、連結第１部材６と連結第２部材７とは、伝動軸４０を挟んだ両側において、それぞれ、上記第１連結壁６２，６２と第２連結壁７２，７２とをそれらの厚み方向に延びるねじ部材８で締結することによって、上記横方向軸１４に相当する各ねじ部材８を中心として所定の抵抗をもって相互回動可能に連結される。より具体的には、各第１連結壁６２，６２には、ねじ穴６２ａが形成されるとともに、各第２連結壁７２，７２には上記ねじ穴６２ａより大径の孔７２ａが形成されている一方、上記ねじ部材８は、上記孔７２ａに嵌合する軸部８ａと、この軸部８ａの先端側に形成された雄ねじ部８ｂと、上記軸部８ａの基端側に形成された頭部８ｃとを有しており、上記筒部７１の先端が各第１連結壁６２，６２の外面に当接するまで上記雄ねじ部８ｂが上記ねじ穴６２ａにねじ込まれる。そして、このねじ部材８の頭部８ｃと第２連結壁７２，７２の外面との間には、皿バネ８１が所定の圧力で圧迫状態に介装されている。皿バネ８１は、各第２連結壁７２，７２を各第１連結壁６２，６２の外面に押しつける作用をし、その結果、第１連結壁６２，６２の外面と第２連結壁７２，７２の内面との間には、所定の摩擦力が発生する。これにより、連結第１部材６に対し、連結第２部材７は、所定の抵抗をもって、各ねじ部材８の軸心、すなわち、上記横方向軸１４を中心として回動可能となる。
【００４３】
伝動軸４０は、少なくとも操作管１０の先端部からと上記回転刃支持部材３０の基端側筒部３５Ａに至る部位、換言すると、上記連結第１部材６と連結第２部材７の各伝動軸挿通孔６１ａ，７１ａ、ないし上記連結第１部材６の一対の第１連結壁６２，６２の間を挿通する部位が、可撓性を有している必要がある。図に示す実施形態では、上記伝動軸４０は、いわゆるフレキシブル軸と呼ばれる部材を採用することができる。このフレキシブル軸は、たとえば、細い金属芯の周りに、金属細線を密に、かつ複数重に巻き付けた構成のものであり、回転トルクを効果的に伝達できながら、比較的自由に撓曲することができるものである。
【００４４】
図に示す実施形態においては、上記操作管１０の内部においては、上記可撓性の伝動軸４０は、たとえば樹脂で成形した保持管５０内に通挿された格好で配置されており、この保持管５０内において、心ぶれを起こすことなく、安定的に回転する。そして、この保持管５０は、その基端側が操作管１０の基端部の内壁に対して実質的に固定され、先端部が上記連結第１部材６の筒部６１の基端側に固定されている。したがって、上記可撓性の伝動軸４０は、上記連結第１部材６と連結第２部材７の各伝動軸挿通孔６１ａ，７１ａを挿通する部位は、ベア状態となる。
【００４５】
なお、伝動軸４０は、上記したように、その基端がクラッチドラム１２の軸１３に、先端が回転刃支持部材３０における入力軸３２に、それぞれ連結されるが、この連結の意味は、回転力が伝達されるように連結されるとの意味である。したがって、たとえば、伝動軸４０の端部を角軸状、またはスプライン状とするとともに、上記クラッチドラム１２の軸１３あるいは上記入力軸３２の各端面に、上記角軸状またはスプライン状の伝動軸４０の端部を受け入れる角穴またはスプライン穴を形成して、伝動軸４０がその軸方向に若干遊び動しうるようにしておくとよい。
【００４６】
以上の構成において、回転刃支持部材３０ないしは回転刃３１に外力が作用すると、上記のように、付与された抵抗に抗して、連結第１部材６に対して連結第２部材７が上記横方向軸１４を中心として所望角度回動させられ、その結果、回転刃支持部材３０ないし回転刃３１は、操作管１０に対する角度姿勢が変化させられ、角度変更後の姿勢は、維持される。そして、伝動軸４０は、連結第１部材６ないし連結第２部材７に通挿されている部位においては、ベア状態となっているので、この伝動軸４０が上記のような連結第２部材７の連結第１部材６に対する回動を必要以上に阻害することはない。また、連結第１部材６および連結第２部材７の各筒部に設けた伝動軸挿通孔６１ａ，７１ａは、上記横方向軸１４付近に近づくほど、上下幅が拡大するテーパ状としてあるので、図３に示すように、連結第１部材６と連結第２部材７とが直線状に延びる状態から上記横方向軸１４を中心とした屈曲状態に変化したとしても、伝動軸４０が上記伝動軸挿通孔６１ａ，７１ａ内をゆるやかに湾曲することができる。したがって、伝動軸４０に無理な負担はなく、また、伝動軸４０が連結第１部材６または連結第２部材７に不用意に接触した状態で回転して損傷するといったことも未然に防止することができる。
【００４７】
上記構成の携帯式動力刈払機１を用いた刈払い作業にあたっては、作業者は、グリップハンドル１７を把持しつつ、操作管１０を左右に振回し、回転する回転刃３１を地表に沿って移動させるようにする。そして、回転刃３１の角度姿勢を変更する必要が生じたとき、スロットルレバーを操作していったん回転刃３１の回転を停止させた状態で、回転刃３１の適部で地面を叩くようにする。たとえば、回転刃３１の先端方で地面を叩くようにしたり、回転刃３１の基端方で地面を叩くようにしたりすることにより、操作管１０の軸線に対する回転刃３１の上記横方向軸１４周りの角度姿勢を所望のように調整することができる。回転刃３１の適部で地面を叩くようにすることは、操作管１０を上下方向に振るといった、刈払い作業に準じた操作管１０の取り扱いによって行なうことができる。このように、上記構成の携帯式動力刈払機１においては、特別な操作部材を操作する必要なく、簡便に回転刃３１の角度姿勢を変更することができる。
【００４８】
これにより、たとえば、爪先上がりの斜面、爪先下がりの斜面、あるいは、土手の斜面等の刈払い作業を行なう場合において、これらの斜面に対して回転刃に適切な姿勢をとらせるべく、操作管１０に対する回転刃３１の角度姿勢を変更する操作が、迅速、容易に行なえるようになる。
【００４９】
また、上記構成の携帯式動力刈払機１は、操作管１０の先端部に対する回転刃支持部材３０の回動中心（横方向軸１４）が、ほぼ操作管１０の軸線と交差するように位置づけられているので、回転刃支持部材３０が上記横方向軸１４を中心として回動した状態においても、回転刃支持部材３０の重心が操作管１０の軸線から大きく離れるということはない。したがって、刈払い作業において上記のように操作管１０を左右に振回操作するに際し、慣性力の影響を受けて操作管１０が軸転してしまい、そのために回転刃３１が左右に揺動してしまうといったことは軽減され、安定した刈払機作業を続行することができる。
【００５０】
図６および図７は、本願発明の携帯式動力刈払機の第２の実施形態を示している。この第２の実施形態においても、操作管１０と一体的な連結第１部材６と回転刃支持部材３０と一体的な連結第２部材７とが横方向軸１４を中心として相互に回動可能に連結されている点は上記した第１の実施形態と同様である。この第２の実施形態では、連結第１部材６に対し、連結第２部材７が所定角度毎に節度感をもって段階係止されるように構成されている。
【００５１】
上記連結第１部材６に対して上記連結第２部材７を回動可能に連結するための構造自体は、第１の実施形態のそれと近似している。すなわち、上記連結第１部材６は、図６に表れているように、操作管１０の内部に嵌入される筒部６１と、この筒部６１の先端側に延出し、かつ側面視略円形をした左右一対の第１連結壁６２，６２と、操作管１０に外嵌される外套部６３とを備えている。そして、上記筒部６１には、伝動軸挿通孔６１ａが軸方向に貫通形成されており、この伝動軸挿通孔６１ａと、その上下幅が筒部６１の先端側に向かうほど拡大するテーパ状とされている。外套部６３の先端部には、連結第２部材７の適部に当接して、連結第２部材７の回動範囲を規定するためのストッパ部６３ａが形成されている。この実施形態では、この外套部６３に、後記する段階係止機構９を構成するための係合部材９１のための収容部（保持孔）９２が一体形成されている。
【００５２】
上記連結第２部材７は、図６に表れているように、回転刃支持部材３０の基端側筒部３５Ａに嵌入される筒部７１を有しており、この筒部７１の後端側延出部７１ｂには、上記連結第１部材６の一対の第１連結壁６２，６２の外面に接し、かつ側面視略円形をした左右一対の第２連結壁７２，７２が形成されている。この一対の第２連結壁７２，７２のうち、右側に位置する連結壁７２の厚み寸法は、左側に位置する連結壁７２の厚み寸法よりも、大きくしてある。後記するように、右側の第２連結壁７２の円筒状外面７２ｂには、後記する段階係止機構９を構成するための複数の凹部７２ｃが形成される。上記延出部７１ｂにはまた、一対の第２連結壁７２，７２の外周にそって延出し、上記連結第１部材６のストッパ部６３ａと協働して連結第２部材７の回動範囲を規定するストッパ部７３ａが設けられている。そして、この連結第２部材７の筒部７１ないし延出部７１ｂにもまた、伝動軸挿通孔７１ａが軸方向に貫通形成されており、この伝動軸挿通孔７１ａは、その上下幅が上記連結第１部材６側に向かうほど拡大するテーパ状とされている。
【００５３】
第１の実施形態と同様、上記連結第１部材６と連結第２部材７とは、伝動軸４０を挟んだ両側において、それぞれ、上記第１連結壁６２，６２と第２連結壁７２，７２とをそれらの厚み方向に延びるねじ部材８で連結することにより、上記横方向軸１４に相当するねじ部材８を中心として相互回動可能とされる。より具体的には、各第１連結壁６２，６２には、ねじ穴６２ａが形成されるとともに、各第２連結壁７２，７２には上記ねじ穴６２ａより大径の孔７２ａが形成されている。一方、上記ねじ部材８は、上記孔に嵌合する軸部８ａと、この軸部８ａの先端側に形成された雄ねじ部８ｂと、上記軸部８ａの基端側に形成された頭部８ｃとを有しており、上記筒部７１の先端が各第１連結壁６２，６２の外面に当接するまで上記雄ねじ部８ｂが上記ねじ穴６２ａにねじ込まれる。軸部８ａの長さは、各第２連結壁７２，７２の厚みとほぼ対応しており、したがって、連結第１部材６に対し、連結第２部材７は、各ねじ部材８の軸線、すなわち、上記横方向軸１４を中心として、回動可能となる。
【００５４】
右側の第２連結壁７２の円筒状外面７２ｂには、所定間隔ごとに、複数の係合凹部７２ｃが形成される。図に示す実施形態では、上記第２連結壁７２の外周に、孔を明けたカラー７２ｄを外嵌することにより、上記係合凹部７２ｃを形成している。一方、連結第１部材の外套部６３には、上記第２連結壁７２の円筒状外面７２ｂの後方側に対向する対向面６３ｃを有する膨出部６３ｂが一体形成されており、この膨出部６３ｂには、上記第２連結壁７２の円筒状外面７２ｂに向けて付勢された係合部材９１が埋設保持される。より具体的には、上記膨出部６３ｂには、操作管１０の軸線と平行な軸線をもつ保持孔９２が形成され、この保持孔９２内に、圧縮コイルバネ９１ａによって付勢された鋼球（係合部材）９１が収容保持されている。こうして、上記円筒状外面７２ｂに形成された複数の係合凹部７２ｃと、円筒状外面７２ｂに向けて付勢された鋼球（係合部材）９１とにより、連結第１部材６に対する連結第２部材７の上記横方向軸１４を中心とした回動に、段階係止力を付与する段階係止機構９が形成されている。
【００５５】
伝動軸４０の配置構成等、その余の構成は、すでに説明した第１の実施形態と同様である。
【００５６】
以上の構成において、回転刃支持部材３０ないし回転刃３１に外力が作用すると、上記の段階係止機構９による係止力に抗して、連結第１部材６に対して連結第２部材７が上記横方向軸１４を中心として所望角度回動させられる。その結果、回転刃支持部材３０ないし回転刃３１は、操作管１０に対する角度姿勢が変化させられ、角度変更後の姿勢は、係合部材９１が他の係合凹部７２ｃに係入することによって所定の角度姿勢に保持される。このように、この実施形態においては、上記段階係止機構９によって変更後の回転刃３１の角度姿勢がより安定させられるとともに、所望の角度姿勢を比較的容易に再現することができる。
【００５７】
なお、実際の使用にあたって、回転刃３１の角度姿勢を変更する必要が生じた場合、いったん回転刃３１の回転を停止させた状態で、回転刃３１の適部で地面を叩くようにする点は、第１の実施形態と同様であり、この第２の実施形態においても、特別な操作部材を操作する必要なく、簡便に回転刃３１の角度姿勢を変更することができる。また、第１の実施形態について上述したのと同様の利点をこの第２の実施形態においても享受することができる。
【００５８】
図８および図９は、本願発明の第３の実施形態を示している。この第３の実施形態は、上記した第２の実施形態と近似しているが、次の点で異なる。すなわち、第２の実施形態では、段階係止機構９は、複数の係合凹部７２ｃが形成された第２連結壁７２の外周面７２ｂに向けて係合部材９１を付勢し、連結第２部材７を所定回動角度毎に節度感をもって係止するものであったが、この第３の実施形態では、上記係合部材９１として、上記第２連結壁７２の外周面７２ｂに向けて付勢されたピン状のものとし、作業者の操作により、このピン状の係合部材９１を強制退避させることができるようにしている。
【００５９】
より具体的には、図８に示すように、連結第１部材６の外套部６３に形成した膨出部６３ｂ内に、操作管１０の軸線と平行な保持孔９２を形成するとともに、この保持孔９２内に、ピン状の係合部材９１を軸方向摺動可能に装填し、かつ、この係合部材９１を常時第２連結壁７２の外周面７２ｂに向けて弾力付勢する一方、この係合部材９１の後端にケーブル９３の一端を連結し、このケーブル９３の他端を操作管１０の適部に取り付けたレバー装置９５（図８）等によって適宜牽引することができるようにしてある。上記のように係合部材９１を弾力付勢するために、この実施形態では、上記保持孔９２の後端開口に取り付けたキャップ部材９４と上記係合部材９１との間に、圧縮コイルバネ９１ａを介装している。
【００６０】
上記係合部材９１が複数の係合凹部７２ｃのいずれかに係合しているとき、連結第２部材７ないし回転刃支持部材３０は、連結第１部材６ないし操作管１０に対する所定の角度姿勢で固定保持されている。上記レバー装置９５を操作して上記のケーブル９３を牽引すると、係合部材９１は強制退避させられ、それまで係合していた係合凹部７２ｃとの係合が解かれる。この時点で連結第２部材７ないし回転刃支持部材３０は、横方向軸１４を中心として自由に回動することができるので、停止状態とした回転刃３１の適部を地面に当てるなどしつつ、回転刃３１に所望の角度姿勢をとらせ、上記レバー装置９５に対する操作力を解除する。そうすると、係合部材９１と対応してその軸線上にいずれかの係合凹部７２ｃが存在する場合には、この係合部材９１はその係合凹部７２ｃに係合し、連結第２部材７ないし回転刃支持部材３０の角度姿勢は固定保持される。また、このとき、係合部材９１と対応してその軸線上にいずれかの係合凹部７２ｃが存在しない場合には、係合部材９１は上記第２連結壁７２の外周を滑動するが、上記連結第２部材７がいずれかの方向に回動して、いずれかの係合凹部７２ｃが係合部材９１の対応位置をとると、この係合部材９１は自動的にその係合凹部７２ｃに係合して、上記連結第２部材７、回転刃支持部材３０ないしは回転刃３１の角度姿勢が固定保持される。
【００６１】
この第３の実施形態では、回転刃３１の角度姿勢を変更するにあたり、上記したレバー装置９５等の操作を必要とするが、係合部材９１を係合凹部７２ｃから強制退避させたときには連結第２部材７ないし回転刃支持部材３０の操作管１０に対するフリー回動可能状態を得ることができるので、やはり、簡便かつ迅速に回転刃３１の角度姿勢を変更することができる。
【００６２】
もちろん、この発明の範囲は上記した各実施形態に限定されるものではなく、各請求項に記載した事項の範囲内でのあらゆる変更は、すべて本願発明の範囲に含まれる。
【００６３】
回転刃支持部材３０を操作管１０の先端部に対し、横方向軸１４を中心として回動可能に支持するための構成は、問われない。たとえば、本実施形態では、連結第１部材６に設けた一対の第１連結壁６２，６２の外側に連結第２部材７に設けた一対の第２連結壁７２，７２を配置しているが、これとは逆に、一対の第２連結壁７２，７２の外側に一対の第１連結壁６２，６２を配置するようにしても、同様に、これら第１連結壁６２と第２連結壁７２間を、ねじ部材８等を用いた相互回動可能構造とすることができる。
【００６４】
段階係止機構９に関し、本実施形態では、連結第２部材７側の第２連結壁７２の円筒状外周面７２ｂに複数の係合凹部７２ｃを設け、連結第１部材６側に上記複数の係合凹部７２ｃのいずれかに係合しうる係合部材９１を設けたが、これとは逆に、連結第１部材６側に円筒内面部を設けてここに複数の係合凹部を設け、連結第２部材７側に上記複数の係合凹部のいずれかに係合しうる係合部材を設けてもよい。
【００６５】
さらには、段階係止機構９に関し、本実施形態では、円筒状外周面７２ｂに複数の係合凹部７２ｃを設けているが、連結第２部材７の第２連結壁７２の側面に、横方向軸１４を中心とする円弧にそって複数の係合凹部７２ｃを設け、連結第１部材６側に上記係合凹部７２ｃに対向する延出部を形成し、この延出部に上記複数の係合凹部７２ｃのいずれかに係合しうる係合部材９１を設けるようにしてもよい。
【図面の簡単な説明】
【図１】本願発明の携帯式動力刈払機の第１の実施形態の全体斜視図である。
【図２】図１のII-II線に沿う断面図である。
【図３】図１のIII-III線に沿う断面図である。
【図４】図１のIV方向矢視図であり、部分的に断面で示す。
【図５】図３のV-V線に沿う断面図である。
【図６】本願発明の携帯式動力刈払機の第２の実施形態を示す図であり、第１の実施形態に関する図５に相当する断面図である。
【図７】図６のVII-VII線に沿う断面図である。
【図８】本願発明の形態式動力刈払機の第３の実施形態を示す図であり、第１の実施形態に関する図５に相当する断面図である。
【図９】図８のIX-IX線に沿う断面図である。
【符号の説明】
１刈払機
６連結第１部材
７連結第２部材
８ねじ部材
８ａ軸部
８ｂ雄ねじ部
８ｃ頭部
９段階係止機構
１０操作管
１１クラッチハウジング
１２クラッチドラム
１４横方向軸
１７グリップハンドル
１８ブラケット
３０回転刃支持部材
３１回転刃
３２入力軸
３３回転刃取付け軸
３５ハウジング
３５Ａ基端側筒部
３５Ｂ先端側筒部
４０伝動軸
５０保持管
６１筒部
６１ａ伝動軸挿通孔
６２第１連結壁
６２ａねじ穴
６３外套部
６３ａストッパ部
６４橋絡部
７１筒部
７２第２連結壁
７２ａ孔
７２ｂ外周面
７２ｃ係合凹部
７２ｄカラー
７３ａストッパ部
９１係合部材
９１ａ圧縮コイルバネ
９２収容部（保持孔）
９３ケーブル
９４キャップ部材
９５レバー装置[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a portable power brush cutter that is used for cutting grasses such as weeds that grow on the ground surface from the vicinity of the root.
[0002]
[Prior art]
This type of portable power brush cutter has a rotating work body at the tip of the operation tube, transmits the rotation output of the power source to the rotating work body through a transmission shaft inserted in the operation tube, and rotates it. It is configured as follows. As the power source, for example, a small gasoline engine is adopted, and generally connected to the base end portion of the operation pipe. The operation tube may be equipped with a grip handle.
[0003]
As the rotary working body, for example, a rotary blade in which a blade such as a saw blade is provided on the outer periphery of a metal disk is employed. For example, as shown in Patent Document 1, normally, the rotation axis of the rotary blade intersects with the axis of the operation tube. This is for the purpose of making the rotary blade as parallel as possible to the ground surface to be trimmed during the work.
[0004]
The mowing operation is performed by the operator holding the machine body swinging the operation tube and moving the rotary blade along the ground surface.
[0005]
By the way, the ground surface to be trimmed is not always flat, and may have a toe-up or toe-down slope. In such a case, if the crossing angle of the rotary shaft of the rotary blade with respect to the axis of the control tube is fixed, the base end of the control tube is lifted high or low in order to make the rotary blade parallel to the ground surface. It is necessary to move the position, and the work becomes very difficult. Also, even when cutting the ground surface, a worker with a tall height keeps the base end of the control tube low, while a worker without a height has a high base end of the control tube. It must be lifted, making it difficult to work. When the engine is directly connected to the base end of the operation pipe, the weight of the engine is high, so that the difficulty of the operation as described above becomes even more so.
[0006]
Therefore, conventionally, as shown in, for example, Patent Document 2, the angle of the rotary shaft of the rotary blade with respect to the axis of the operation tube can be adjusted, depending on the inclination of the target ground surface or the operator Depending on the height, there is one in which the rotary blade can be made to take a posture parallel to the ground surface while the base end portion of the operation tube is held at an easy height for the operator.
[0007]
[Patent Document 1]
JP 63-56214 A
[Patent Document 2]
Japanese Utility Model Publication No. 3-17619
[0008]
[Problems to be solved by the invention]
In the configuration shown in Patent Document 2, a support rod extending obliquely downward is provided at the tip of the operation tube, and a rotary blade is attached to the support rod so as to be able to swing back and forth. An angle of the rotary blade can be adjusted by using a shaft inserted through a flexible transmission shaft and moving the operation tube and the transmission shaft relative to each other by operating means.
[0009]
However, in the above configuration, since a relatively heavy rotary blade is supported at a position far away from the tip of the operation tube, the influence of inertia force is exerted when the operation tube is swung in the left-right direction. As a result, the operation tube rotates and there is a problem that the rotary blade swings left and right. That is, when the swing operation of the operation tube is performed, the rotary blade swings in an unstable manner, which leads to deterioration in workability.
[0010]
In the above configuration, since the dimension from the tip of the operation tube to the rotary blade is relatively large, it is very difficult to perform the brushing operation in a situation where an obstacle exists at a position away from the ground surface. There is also a problem of becoming.
[0011]
In addition, since the weight of the tip of the operation tube is increased, there is a problem that the swinging operation is difficult.
[0012]
Furthermore, the power transmission from the operation tube to the rotary blade employs a configuration in which a flexible transmission shaft is inserted into the flexible tube. Such a flexible tube is a member that inserts and holds a transmission shaft that rotates at a high speed, and is also a member that needs to withstand a predetermined pulling force and compression force. Is relatively large. Therefore, in the above configuration, the angle of the rotary blade is changed by forcibly bending and deforming the dual configuration of the flexible tube having such a large bending resistance and the transmission shaft. In order to change the angle of the blade, an operating force that resists the large bending resistance described above is required. Thus, in the portable brush cutter having the above-described configuration described in Patent Document 2, it cannot be said that the angle of the rotary blade can be changed easily.
[0013]
The present invention has been conceived under the circumstances described above, and the angle and orientation of the rotary blade with respect to the axis of the operation tube can be made more lightly and without increasing the weight or size of the tip of the operation tube. The challenge is to make it easy to change.
[0014]
DISCLOSURE OF THE INVENTION
In order to solve the above problems, the present invention employs the following technical means.
[0015]
That is, the portable power brush cutter provided by the first aspect of the present invention includes an operation tube, a transmission shaft inserted through the operation tube, and a rotary blade support member provided at the tip of the operation tube. A portable power brush cutter configured to transmit a rotational output of a power source to the rotary blade via the transmission shaft and rotate the rotary blade. The rotary blade support member includes an input shaft to which the tip of the transmission shaft is coupled, and a rotary blade mounting shaft that is linked to the input shaft via a bevel gear mechanism. A first connecting member is provided at the distal end of the operation tube, and a second connecting member is provided on the rotary blade support member. The first connecting member and the second connecting member are connected to each other. Are connected so as to be rotatable with a predetermined resistance around a lateral axis orthogonal to the axis of the operation tube, and the transmission shaft is connected to each of the connection first member and the connection second member. A conduction shaft insertion hole that is inserted in a penetrating manner is formed, and a pair of first connection walls that are opposed to each other with the transmission shaft interposed therebetween are formed on one of the connection first member and the connection second member. In addition, a pair of second connection walls that are in contact with the outer surfaces of the pair of first connection walls are formed on the other of the connection first member and the connection second member. The first connecting wall and the second connecting wall are inserted in the thickness direction thereof. And they are connected respectively by a screw member corresponding to the horizontal axis, and, The transmission shaft is characterized in that at least a portion from the distal end portion of the operation tube to the rotary blade support member has flexibility.
[0017]
In a preferred embodiment, the transmission shaft insertion holes formed respectively in the first connecting member and the second connecting member are tapered so that the vertical width generally increases as the horizontal axis is approached.
[0019]
In a preferred embodiment, the screw member includes a shaft portion positioned in a hole formed in the second connection wall, and a screw hole formed in a distal end side of the shaft portion and formed in the first connection wall. And a head portion formed on the base end side of the shaft portion, and the distal end surface of the shaft portion is on the outer surface of the first connecting wall. A spring member is interposed between the head and the outer surface of the second connecting wall in a state where the male screw portion is screwed into the screw hole until it comes into contact.
[0020]
In the portable power brush cutter according to the first aspect of the present invention, the rotary blade support member rotates with a predetermined resistance around a lateral axis substantially orthogonal to the axis of the operation tube with respect to the tip of the operation tube. Supported as possible. Since the transmission shaft from the tip of the operation tube to the rotary blade support member is flexible, the rotary blade support member rotates around the horizontal axis with respect to the operation tube as described above. The transmission shaft does not hinder the movement. Since the rotary blade support member is rotatably supported with a predetermined resistance with respect to the operation tube, the rotary blade support member rotates in the direction in which the external force acts, and the posture after the rotation is the above Held by resistance.
[0021]
In actual use, when it is necessary to change the angle and orientation of the rotary blade, the worker strikes the ground with an appropriate portion of the rotary blade while the rotation of the rotary blade is once stopped. For example, by hitting the ground with the tip of the rotary blade or hitting the ground with the base end of the rotary blade, the angular attitude of the rotary blade around the horizontal axis with respect to the axis of the operation tube is desired. Can be adjusted as follows. The hitting of the ground with an appropriate portion of the rotary blade can be performed by handling the operation tube according to the brushing work, such as shaking the operation tube in the vertical direction. Thus, in the portable power brush cutter having the above-described configuration, it is possible to easily change the angular posture of the rotary blade without the need to operate a special operation member.
[0022]
The portable power brush cutter provided by the second aspect of the present invention includes an operation tube, a transmission shaft inserted through the operation tube, and a rotary blade support member provided at the tip of the operation tube. A portable power brush cutter configured to transmit a rotational output of a power source to the rotary blade via the transmission shaft and to rotate the rotary blade. The blade support member includes an input shaft to which the tip of the transmission shaft is coupled, and a rotary blade mounting shaft that is linked to the input shaft via a bevel gear mechanism. It is supported with respect to the operation tube so that it can rotate stepwise around a horizontal axis perpendicular to the axis. A first connecting member is provided at the tip of the operation tube, and a second connecting member is provided on the rotary blade support member. The first connecting member and the second connecting member are connected to each other. The first connecting member and the second connecting member are pivotally connected around the transverse axis, and are formed with conductive shaft insertion holes through which the transmission shaft is inserted in a penetrating manner. A pair of first connection walls are formed on one of the connection first member and the connection second member so as to face each other with the transmission shaft interposed therebetween, and the connection first member and the connection second member. On the other side, a pair of second connection walls that are in contact with the outer surfaces of the pair of first connection walls are formed, and each of the first connection walls and the second connection walls that are located across the transmission shaft are Each screw member is inserted in the thickness direction and corresponds to the horizontal axis. It is connected, and, The transmission shaft is characterized in that at least a portion from the distal end portion of the operation tube to the rotary blade support member has flexibility.
[0024]
In a preferred embodiment, the transmission shaft insertion holes formed respectively in the first connecting member and the second connecting member are tapered so that the vertical width generally increases as the horizontal axis is approached.
[0026]
In a preferred embodiment, the connection first member or the integral member is interposed between the connection first member or the integral member and the connection second member or the integral member. A stage locking mechanism is provided that can be locked at every predetermined rotation angle when the second member connected to the member or the member integral with the second member rotates about the lateral axis.
[0027]
In a preferred embodiment, the stage locking mechanism is configured such that one of the connection first member or the member integrated with the connection first member and the connection second member or the member integrated with the connection member is centered on the lateral axis. A plurality of engaging recesses are formed along the circular arc, and the engaging recess is formed on the other of the first connecting member or a member integral therewith and the second connecting member or a member integral therewith. It is formed by providing an engaging member that is elastically biased toward the formed surface.
[0028]
In another preferred embodiment, the step-locking mechanism is configured such that the lateral axis is centered on one of the first connecting member or the member integral therewith and the second connecting member or the member integral therewith. While the plurality of engaging recesses are formed along the arc, the engaging recesses are formed on the other of the first connecting member or the member integrated with the second connecting member or the member integrated with the second member. An engaging member biased toward the formed surface is provided, and the engaging member can be forcibly retracted from the engaging recess against an urging force by an operator's operation. It is configured.
[0029]
In the portable power brush cutter according to the second aspect of the present invention, in the portable power brush cutter according to the first aspect, the rotary blade support member has a predetermined resistance around the lateral axis with respect to the operation tube. Is different from the operation tube in that the rotary blade support member can be rotated around the horizontal axis so as to be able to be locked in stages.
[0030]
In the preferred embodiment, the means for enabling stepwise locking is configured such that the engaging member is engaged with the plurality of recesses with a sense of moderation. Even in this case, the rotary blade support member is rotated around the lateral axis by an external force, and the angular posture is determined in advance by the engagement between the plurality of recesses and the engagement member. Become. Therefore, the changed angular orientation is more stable, and the desired angular orientation can be reproduced relatively easily.
[0031]
Further, in another preferred embodiment, the means for enabling stepwise locking as described above allows the engaging member to be engaged with the plurality of recesses by the biasing force, and the engaging member is A configuration is adopted that can be forcibly retreated against the urging force by an operation. In this case, in a state where the engaging member is forcibly retracted, the rotary blade support member can be freely rotated around the lateral axis with respect to the operation tube. Then, when the operating force that forcibly retracted the engaging member with the rough posture of the rotary blade obtained by using the ground is released, the engaging member is automatically moved to one of the recesses by the biasing force. And the posture of the rotary blade is finally determined. Thus, also with the portable power brush cutter according to the second aspect of the present invention, the angular posture of the rotary blade can be changed lightly and easily.
[0032]
Other features and advantages of the present invention will become more apparent from the detailed description given below with reference to the drawings.
[0033]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a preferred embodiment of the present invention will be specifically described with reference to the drawings.
[0034]
1 to 5 show a portable power brush cutter 1 according to a first embodiment of the present invention. As shown in FIG. 1, the brush cutter 1 includes an operation tube 10, a small engine 20 connected to the proximal end of the operation tube 10, and a rotary blade 31 supported by a distal end portion of the operation tube 10. The rotational output of the small engine 20 is transmitted to the rotary blade 31 via the transmission shaft 40 inserted into the operation tube 10.
[0035]
The operation tube 10 is formed of a lightweight metal pipe such as aluminum, and a clutch housing 11 is integrally attached to a base end portion thereof as shown in FIG. The clutch housing 11 is connected to the main body of the engine 20, whereby the base end portion of the operation tube 10 is connected to the engine 20. A clutch drum 12 is rotatably supported inside the clutch housing 11, and a base end of a transmission shaft 40 is connected to the shaft 13 of the clutch drum 12. The clutch drum 12 forms a centrifugal clutch in cooperation with a clutch shoe (not shown) on the engine side. When the rotational speed of the engine 20 is increased by operating a throttle lever (not shown), the centrifugal clutch transmits the rotational output of the engine 20 to the clutch drum 12 and rotates the transmission shaft 40.
[0036]
A rotary blade support member 30 is provided at the distal end of the operation tube 10. As shown in FIG. 3, the rotary blade support member 30 is linked to the input shaft 32 to which the distal end portion of the transmission shaft 40 is coupled, and the input shaft 32 via a bevel gear mechanism. The rotary blade mounting shaft 33 is provided in a housing 35. That is, the input shaft 32 includes a first bevel gear 34 at the tip thereof and is rotatably supported through a bearing 36 in the proximal end side cylindrical portion 35A of the housing 35, while the rotary blade mounting shaft 33 includes a second bevel gear 37 that meshes with the first bevel gear 34 on the base end side thereof, and is rotatably supported via a bearing 38 in the distal end side cylindrical portion 35 </ b> B of the housing 35. That is, in the rotary blade support member 30, the direction of the rotational power transmission shaft is changed so that the input shaft 32 and the rotary blade mounting shaft 33 intersect at an angle of about 120 degrees. A rotary blade 31 is attached to the tip of the rotary blade attachment shaft 33. As the rotary blade 31, for example, a blade in which a saw blade is directly formed on the outer periphery of a metal disk or a blade having a super steel tip blade attached thereto is suitably used.
[0037]
A grip handle 17 extending in the lateral direction is attached to the proximal end of the operation tube 10 via a suitable bracket 18. In addition, a throttle lever (not shown) for controlling the rotational speed of the engine 20 is attached to an appropriate position of the operation tube 10.
[0038]
The rotary blade support member 30 is coupled to the distal end portion of the operation tube 10 so as to be rotatable around the lateral axis 14. In the present invention, the lateral axis 14 is set substantially perpendicular to the axis of the operation tube 10. In other words, the lateral axis 14 intersects the axis of the operation tube 10 or is not so far away from the axis of the operation tube 10 in the vertical direction.
[0039]
More specifically, the connection first member 6 is integrally attached to the distal end portion of the operation tube 10, while the connection second member 7 is connected to the proximal end side cylindrical portion 35 </ b> A of the housing 35 of the rotary blade support member 30. The first connecting member 6 and the second connecting member 7 are integrally connected to each other with a predetermined resistance around the lateral shaft 14 so as to be rotatable.
[0040]
As shown in FIGS. 3 to 5, the connecting first member 6 has a cylindrical portion 61 fitted into the operation tube 10, and extends to the distal end side of the cylindrical portion 61, and has a substantially circular shape in side view. A pair of left and right first connecting walls 62, 62 and an operation tube 10 And a mantle portion 63 to be externally fitted. The pair of first connection walls 62, 62 are opposed to each other with a sufficient interval between the transmission shafts 40 disposed therebetween. The upper and lower portions of the pair of first connection walls 62, 62 are connected to each other by a bridge portion 64 connected to the outer cover portion 63. Therefore, the interval between the pair of first connection walls 62, 62 is inadvertent. It will not be reduced. A conductive shaft insertion hole 61 a is formed through the cylindrical portion 61 of the connection first member 6 in the axial direction, and the vertical width of the conductive shaft insertion hole 61 a increases toward the distal end side of the cylindrical portion 61. The taper is enlarged. A stopper portion 63 a for defining a rotation range of the second connecting member 7 around the lateral axis 14 is formed at the distal end of the outer cover 63 so as to come into contact with an appropriate portion of the second connecting member 7 to be described later. ing.
[0041]
As shown in FIGS. 3 to 5, the connecting second member 7 has a cylindrical portion 71 fitted into the proximal end side cylindrical portion 35 </ b> A of the rotary blade support member 30, and the rear of the cylindrical portion 71. A pair of left and right second connection walls 72, 72 that are in contact with the outer surfaces of the pair of first connection walls 62, 62 of the connection first member 6 and have a substantially circular shape in a side view are formed on the end-side extending portion 71 b. ing. The extending portion 71b also extends along the outer periphery of the pair of second connecting walls 72, 72, and cooperates with the stopper portion 63a of the connecting first member 6 to rotate the connecting second member 7. The stopper portion 73a and the pair of second connecting walls 72, 72 are separated from each other. A transmission shaft insertion hole 71a is formed in the cylindrical portion 71 through the extension portion 71b of the second connecting member 7 so as to penetrate in the axial direction. The taper shape expands toward the member 6 side.
[0042]
As clearly shown in FIG. 5, the first connecting wall 62 and the second connecting wall 72 are connected to the first connecting wall 6 and the second connecting member 7 on both sides of the transmission shaft 40, respectively. By fastening the screws 72 with the screw members 8 extending in the thickness direction, the screw members 8 corresponding to the lateral shaft 14 are connected to each other so as to be rotatable with a predetermined resistance. More specifically, a screw hole 62a is formed in each first connection wall 62, 62, and a hole 72a having a diameter larger than that of the screw hole 62a is formed in each second connection wall 72, 72. On the other hand, the screw member 8 includes a shaft portion 8a fitted into the hole 72a, a male screw portion 8b formed on the distal end side of the shaft portion 8a, and a head formed on the proximal end side of the shaft portion 8a. The male screw portion 8b is screwed into the screw hole 62a until the tip of the cylindrical portion 71 comes into contact with the outer surfaces of the first connecting walls 62, 62. A disc spring 81 is interposed between the head 8c of the screw member 8 and the outer surfaces of the second connecting walls 72 and 72 in a compressed state with a predetermined pressure. The disc spring 81 acts to press the second connecting walls 72, 72 against the outer surfaces of the first connecting walls 62, 62. As a result, the outer surface of the first connecting walls 62, 62 and the second connecting walls 72, 72 are pressed. A predetermined frictional force is generated between the inner surface and the inner surface. Thereby, the connection 2nd member 7 becomes rotatable with respect to the connection 1st member 6 centering on the axial center of each screw member 8, ie, the said horizontal direction axis | shaft 14, with predetermined resistance.
[0043]
The transmission shaft 40 is at least a portion extending from the distal end portion of the operation tube 10 to the proximal end side cylindrical portion 35A of the rotary blade support member 30, in other words, the transmission shafts of the connection first member 6 and the connection second member 7. The insertion holes 61a and 71a, or the parts that pass between the pair of first connection walls 62 and 62 of the connection first member 6 need to be flexible. In the embodiment shown in the figure, the transmission shaft 40 can employ a so-called flexible shaft member. This flexible shaft has, for example, a structure in which fine metal wires are wound densely and in multiple layers around a thin metal core, and can bend relatively freely while effectively transmitting rotational torque. It is something that can be done.
[0044]
In the embodiment shown in the figure, inside the operation tube 10, the flexible transmission shaft 40 is arranged in a manner inserted through a holding tube 50 formed of resin, for example. The tube 50 rotates stably without causing a shake. The holding tube 50 has a proximal end substantially fixed to the inner wall of the proximal end portion of the operation tube 10, and a distal end portion of the connection first member. 6 It is being fixed to the base end side of the cylinder part 61 of this. Therefore, the flexible transmission shaft 40 is connected to the first connecting member. 6 And connected second member 7 The parts that pass through the transmission shaft insertion holes 61a and 71a are in a bare state.
[0045]
Note that, as described above, the transmission shaft 40 has a base end connected to the shaft 13 of the clutch drum 12 and a tip connected to the input shaft 32 of the rotary blade support member 30, respectively. It means that it is connected so that force is transmitted. Therefore, for example, the end portion of the transmission shaft 40 is formed into a square shaft shape or a spline shape, and the shaft shaft 13 of the clutch drum 12 or the input shaft 32 is provided on the end surface of the square shaft or spline shape. It is preferable to form a square hole or a spline hole for receiving the end of the transmission shaft 40 so that the transmission shaft 40 can be slightly idled in the axial direction.
[0046]
In the above configuration, when an external force acts on the rotary blade support member 30 or the rotary blade 31, as described above, the connection second member 7 is connected to the connection first member 6 against the applied resistance. As a result, the rotary blade support member 30 or the rotary blade 31 is changed in the angular posture with respect to the operation tube 10, and the posture after the angle change is maintained. Since the transmission shaft 40 is in a bare state at the portion inserted through the first connecting member 6 or the second connecting member 7, the transmission shaft 40 is connected to the second connecting member 7 as described above. The rotation with respect to the connection first member 6 is not hindered more than necessary. Further, the transmission shaft insertion holes 61a and 71a provided in the respective cylindrical portions of the first connecting member 6 and the second connecting member 7 are tapered so that the vertical width increases as they approach the lateral axis 14. As shown in FIG. 3, even if the connecting first member 6 and the connecting second member 7 change from a linearly extending state to a bent state about the lateral shaft 14, the transmission shaft 40 is connected to the transmission shaft. The inside of the insertion holes 61a and 71a can be gently curved. Therefore, there is no unreasonable burden on the transmission shaft 40, and it is possible to prevent the transmission shaft 40 from rotating and being damaged in an inadvertent contact with the first connecting member 6 or the second connecting member 7. Can do.
[0047]
In the brush cutting work using the portable power brush cutter 1 having the above-described configuration, the operator swings the operation tube 10 left and right while holding the grip handle 17 and moves the rotating rotary blade 31 along the ground surface. I will let you. Then, when it becomes necessary to change the angular posture of the rotary blade 31, the throttle lever is operated to stop the rotation of the rotary blade 31 and then strike the ground with an appropriate portion of the rotary blade 31. For example, by hitting the ground with the distal end of the rotary blade 31 or by hitting the ground with the proximal end of the rotary blade 31, the horizontal axis 14 around the rotary blade 31 with respect to the axis of the operation tube 10. Can be adjusted as desired. The hitting of the ground with an appropriate portion of the rotary blade 31 can be performed by handling the operation tube 10 according to the brushing work, such as shaking the operation tube 10 in the vertical direction. Thus, in the portable power brush cutter 1 having the above-described configuration, the angular posture of the rotary blade 31 can be easily changed without the need to operate a special operation member.
[0048]
Thereby, for example, when performing a brushing operation such as a slope with a raised toe, a slope with a lowered toe, or a slope on the bank, the operation tube 10 is set so that the rotary blade takes an appropriate posture with respect to these slopes. The operation of changing the angular posture of the rotary blade 31 with respect to can be quickly and easily performed.
[0049]
Further, the portable power brush cutter 1 having the above-described configuration is positioned such that the rotation center (lateral axis 14) of the rotary blade support member 30 with respect to the distal end portion of the operation tube 10 substantially intersects the axis of the operation tube 10. Therefore, even when the rotary blade support member 30 is rotated around the lateral axis 14, the center of gravity of the rotary blade support member 30 is not greatly separated from the axis of the operation tube 10. Therefore, when the operation tube 10 is swung left and right as described above in the brushing operation, the operation tube 10 rotates due to the influence of the inertial force, so that the rotary blade 31 swings left and right. It is possible to continue the brush cutter operation stably.
[0050]
6 and 7 show a second embodiment of the portable power brush cutter according to the present invention. Also in the second embodiment, the connection first member 6 integral with the operation tube 10 and the connection second member 7 integral with the rotary blade support member 30 can be rotated around the horizontal axis 14. The point connected to is the same as in the first embodiment. In this 2nd Embodiment, it is comprised so that the connection 2nd member 7 may be phase-locked with a moderate feeling for every predetermined angle with respect to the connection 1st member 6. FIG.
[0051]
The structure itself for rotatably connecting the second connecting member 7 to the first connecting member 6 is similar to that of the first embodiment. That is, as shown in FIG. 6, the connecting first member 6 has a cylindrical portion 61 fitted into the operation tube 10, and extends to the distal end side of the cylindrical portion 61, and has a substantially circular shape in side view. The left and right paired first connection walls 62 and 62 and a mantle portion 63 fitted on the operation tube 10 are provided. A transmission shaft insertion hole 61 a is formed in the cylindrical portion 61 so as to penetrate in the axial direction. The transmission shaft insertion hole 61 a and a tapered shape in which the vertical width increases toward the distal end side of the cylindrical portion 61. Has been. A stopper portion 63 a for abutting an appropriate portion of the connection second member 7 and defining a rotation range of the connection second member 7 is formed at the distal end portion of the outer cover portion 63. In this embodiment, a housing portion (holding hole) 92 for an engaging member 91 for constituting a stage locking mechanism 9 to be described later is integrally formed on the mantle portion 63.
[0052]
As shown in FIG. 6, the connecting second member 7 has a cylindrical portion 71 fitted into the proximal end side cylindrical portion 35 </ b> A of the rotary blade support member 30, and the rear end side of the cylindrical portion 71. A pair of left and right second connection walls 72, 72 that are in contact with the outer surfaces of the pair of first connection walls 62, 62 of the connection first member 6 and have a substantially circular shape when viewed from the side are formed on the extending portion 71b. . Of the pair of second connection walls 72, 72, the thickness dimension of the connection wall 72 positioned on the right side is larger than the thickness dimension of the connection wall 72 positioned on the left side. As will be described later, the cylindrical outer surface 72b of the second connecting wall 72 on the right side is formed with a plurality of recesses 72c for constituting a stage locking mechanism 9 to be described later. The extending portion 71b also extends along the outer periphery of the pair of second connecting walls 72, 72, and cooperates with the stopper portion 63a of the connecting first member 6 to rotate the connecting second member 7. The stopper part 73a which prescribes | regulates is provided. A transmission shaft insertion hole 71a is also formed in the cylindrical portion 71 to the extension portion 71b of the second connecting member 7 so as to penetrate in the axial direction. The taper shape expands toward the first member 6 side.
[0053]
As in the first embodiment, the connection first member 6 and the connection second member 7 are the first connection walls 62, 62 and the second connection walls 72, 72 on both sides of the transmission shaft 40, respectively. And screw members extending in the thickness direction 8 By connecting with each other, mutual rotation is possible about the screw member 8 corresponding to the lateral shaft 14. More specifically, a screw hole 62a is formed in each first connection wall 62, 62, and a hole 72a having a diameter larger than that of the screw hole 62a is formed in each second connection wall 72, 72. Yes. On the other hand, the screw member 8 includes a shaft portion 8a fitted into the hole, a male screw portion 8b formed on the distal end side of the shaft portion 8a, and a head portion 8c formed on the proximal end side of the shaft portion 8a. The male screw portion 8b is screwed into the screw hole 62a until the tip of the cylindrical portion 71 comes into contact with the outer surfaces of the first connecting walls 62, 62. The length of the shaft portion 8a substantially corresponds to the thickness of each of the second connection walls 72, 72. Therefore, the connection second member 7 is connected to the connection first member 6 with respect to the axis of each screw member 8, that is, It is possible to rotate about the horizontal axis 14.
[0054]
A plurality of engaging recesses 72c are formed on the cylindrical outer surface 72b of the second connecting wall 72 on the right side at predetermined intervals. In the embodiment shown in the figure, the engagement recess 72 c is formed by fitting a collar 72 d with a hole on the outer periphery of the second connection wall 72. On the other hand, a bulging portion 63b having a facing surface 63c facing the rear side of the cylindrical outer surface 72b of the second connecting wall 72 is integrally formed on the outer cover portion 63 of the first connecting member. The engaging member 91 urged toward the cylindrical outer surface 72b of the second connecting wall 72 is embedded and held in 63b. More specifically, a holding hole 92 having an axis parallel to the axis of the operation tube 10 is formed in the bulging portion 63b, and a steel ball urged by a compression coil spring 91a (in this holding hole 92) (Engagement member) 91 is accommodated and held. Thus, the second connection to the connection first member 6 is achieved by the plurality of engagement recesses 72c formed on the cylindrical outer surface 72b and the steel balls (engagement members) 91 biased toward the cylindrical outer surface 72b. A stage locking mechanism 9 is provided that applies a stage locking force to the rotation of the member 7 about the lateral axis 14.
[0055]
Other configurations such as the arrangement configuration of the transmission shaft 40 are the same as those of the first embodiment already described.
[0056]
In the above configuration, when an external force acts on the rotary blade support member 30 or the rotary blade 31, the connection second member 7 is against the connection first member 6 against the locking force by the above-described stage locking mechanism 9. A desired angle is rotated about the horizontal axis 14. As a result, the rotary blade support member 30 to the rotary blade 31 are changed in the angle posture with respect to the operation tube 10, and the posture after the angle change is determined by the engagement member 91 engaging with the other engagement recess 72c. Is held in the angle posture. Thus, in this embodiment, the angle attitude of the rotary blade 31 after the change is further stabilized by the stage locking mechanism 9 and a desired angle attitude can be reproduced relatively easily.
[0057]
In actual use, when it is necessary to change the angular orientation of the rotary blade 31, the point that the rotary blade 31 is once stopped and the ground is hit by an appropriate portion of the rotary blade 31 is the point. In the second embodiment, the angular posture of the rotary blade 31 can be easily changed without operating a special operation member. The same advantages as those described above for the first embodiment can also be enjoyed in the second embodiment.
[0058]
8 and 9 show a third embodiment of the present invention. The third embodiment is similar to the second embodiment described above, but differs in the following points. That is, in the second embodiment, the stage locking mechanism 9 urges the engagement member 91 toward the outer peripheral surface 72b of the second connection wall 72 in which the plurality of engagement recesses 72c are formed, and the connection second In this third embodiment, the member 7 is attached toward the outer peripheral surface 72b of the second connecting wall 72 as the engaging member 91. The pin-shaped engagement member 91 is forcibly retracted by an operator's operation.
[0059]
More specifically, as shown in FIG. 8, a holding hole 92 parallel to the axis of the operation tube 10 is formed in the bulging portion 63 b formed in the mantle portion 63 of the connection first member 6, and this holding is performed. A pin-shaped engagement member 91 is slidably loaded in the hole 92 and the engagement member 91 is constantly elastically biased toward the outer peripheral surface 72b of the second connecting wall 72. One end of the cable 93 is connected to the rear end of the engaging member 91, and the other end of the cable 93 can be appropriately pulled by a lever device 95 (FIG. 8) attached to an appropriate portion of the operation tube 10. is there. In order to elastically bias the engaging member 91 as described above, in this embodiment, a compression coil spring 91a is provided between the engaging member 91 and the cap member 94 attached to the rear end opening of the holding hole 92. It is intervening.
[0060]
When the engagement member 91 is engaged with any one of the plurality of engagement recesses 72 c, the connection second member 7 or the rotary blade support member 30 has a predetermined angular attitude with respect to the connection first member 6 or the operation tube 10. It is fixed and held by. When the lever device 95 is operated to pull the cable 93, the engaging member 91 is forcibly retracted, and the engagement with the engaging recess 72c that has been engaged is released. At this time, since the connecting second member 7 or the rotary blade support member 30 can freely rotate about the lateral axis 14, the appropriate portion of the rotary blade 31 in a stopped state is applied to the ground. Then, the rotary blade 31 is made to take a desired angular posture, and the operating force for the lever device 95 is released. Then, when any of the engagement recesses 72c exists on the axis corresponding to the engagement member 91, the engagement member 91 engages with the engagement recess 72c, and the connected second member 7 or The angular posture of the rotary blade support member 30 is fixed and held. At this time, when any of the engaging recesses 72c does not exist on the axis corresponding to the engaging member 91, the engaging member 91 slides on the outer periphery of the second connecting wall 72. When the connecting second member 7 rotates in any direction and any one of the engaging recesses 72c takes the corresponding position of the engaging member 91, the engaging member 91 automatically moves into the engaging recess 72c. By engaging, the angular posture of the second connecting member 7 and the rotary blade support member 30 or the rotary blade 31 is fixed and held.
[0061]
In the third embodiment, the operation of the lever device 95 described above is required to change the angular posture of the rotary blade 31, but when the engaging member 91 is forcibly retracted from the engaging recess 72c, the connected second Since it is possible to obtain a state in which the two members 7 or the rotary blade support member 30 can freely rotate with respect to the operation tube 10, the angular posture of the rotary blade 31 can be changed easily and quickly.
[0062]
Of course, the scope of the present invention is not limited to the above-described embodiments, and all modifications within the scope of the matters described in each claim are included in the scope of the present invention.
[0063]
The configuration for supporting the rotary blade support member 30 so as to be rotatable about the lateral axis 14 with respect to the distal end portion of the operation tube 10 is not limited. For example, in the present embodiment, the pair of second connection walls 72, 72 provided on the connection second member 7 are arranged outside the pair of first connection walls 62, 62 provided on the connection first member 6. On the contrary, even if the pair of first connection walls 62, 62 are arranged outside the pair of second connection walls 72, 72, the first connection wall 62 and the second connection wall are similarly arranged. Between 72, it can be set as the structure which can mutually rotate using the screw member 8 grade | etc.,.
[0064]
With respect to the stage locking mechanism 9, in this embodiment, a plurality of engagement recesses 72 c are provided on the cylindrical outer peripheral surface 72 b of the second connection wall 72 on the connection second member 7 side, and the plurality of engagement recesses 72 c are provided on the connection first member 6 side. The engagement member 91 that can be engaged with any of the engagement recesses 72c is provided, but conversely, a cylindrical inner surface portion is provided on the connection first member 6 side, and a plurality of engagement recesses are provided here, An engagement member that can be engaged with any of the plurality of engagement recesses may be provided on the connection second member 7 side.
[0065]
Furthermore, with respect to the stage locking mechanism 9, in the present embodiment, a plurality of engaging recesses 72 c are provided on the cylindrical outer peripheral surface 72 b, but laterally on the side surface of the second connection wall 72 of the connection second member 7. A plurality of engaging recesses 72c are provided along an arc centered on the shaft 14, and an extending portion facing the engaging recess 72c is formed on the connecting first member 6 side, and the plurality of engaging portions are formed on the extending portion. An engaging member 91 that can engage with any of the mating recesses 72c may be provided.
[Brief description of the drawings]
FIG. 1 is a first embodiment of a portable power brush cutter according to the present invention; Form FIG.
2 is a cross-sectional view taken along the line II-II in FIG.
3 is a cross-sectional view taken along line III-III in FIG.
4 is a view in the direction of arrows IV in FIG. 1, partially shown in cross section.
5 is a cross-sectional view taken along line VV in FIG.
FIG. 6 is a diagram showing a second embodiment of the portable power brush cutter according to the present invention, and is a cross-sectional view corresponding to FIG. 5 relating to the first embodiment.
7 is a cross-sectional view taken along line VII-VII in FIG.
FIG. 8 is a diagram showing a third embodiment of the motive power brush cutter according to the present invention, and is a cross-sectional view corresponding to FIG. 5 relating to the first embodiment.
9 is a cross-sectional view taken along line IX-IX in FIG.
[Explanation of symbols]
1 Brush cutter
6 Connected first member
7 Connection second member
8 Screw members
8a Shaft
8b Male thread
8c head
9-stage locking mechanism
10 Operation tube
11 Clutch housing
12 Clutch drum
14 Horizontal axis
17 Grip handle
18 Bracket
30 Rotary blade support member
31 Rotating blade
32 input shaft
33 Rotary blade mounting shaft
35 housing
35A Base end cylinder
35B Tip side cylinder
40 Transmission shaft
50 Holding tube
61 Tube
61a Transmission shaft insertion hole
62 First connecting wall
62a Screw hole
63 Mantle
63a Stopper part
64 Bridge
71 Tube
72 Second connecting wall
72a hole
72b outer peripheral surface
72c engaging recess
72d color
73a Stopper part
91 engaging member
91a Compression coil spring
92 Housing (holding hole)
93 cable
94 Cap member
95 Lever device

Claims

An operation tube, a transmission shaft inserted through the operation tube, and a rotary blade supported via a rotary blade support member provided at the tip of the operation tube, the rotational output of the power source is transmitted to the transmission shaft A portable power brush cutter configured to transmit to the rotary blade via the rotary blade and rotate the rotary blade,
The rotary blade support member includes an input shaft to which the tip of the transmission shaft is coupled, and a rotary blade mounting shaft that is linked to the input shaft via a bevel gear mechanism .
A first connecting member is provided at the tip of the operation tube, and a second connecting member is provided on the rotary blade support member. The first connecting member and the second connecting member are The transmission shaft is connected to the connection first member and the connection second member in a penetrating manner so as to be rotatable with a predetermined resistance around a horizontal axis orthogonal to the axis of the operation tube. Conduction shaft insertion hole is formed,
One of the first connecting member and the second connecting member is formed with a pair of first connecting walls facing each other with the transmission shaft interposed therebetween, and the other of the first connecting member and the second connecting member. Are formed with a pair of second connection walls in contact with the outer surfaces of the pair of first connection walls, and each of the first connection walls and the second connection walls located across the transmission shaft are in the thickness direction thereof. Are connected to each other by screw members corresponding to the transverse axis, and
The portable power brush cutter, wherein at least a portion of the transmission shaft from the distal end portion of the operation tube to the rotary blade support member has flexibility.

2. The portable power according to claim 1 , wherein the transmission shaft insertion holes respectively formed in the first connecting member and the second connecting member have a tapered shape that generally increases in vertical width as approaching the lateral axis. Brush cutter.

The screw member is formed in a hole formed in the hole formed in the second connection wall, and is screwed into a screw hole formed in a tip side of the shaft part and formed in the first connection wall, and the shaft part. A male screw portion having a smaller diameter and a head portion formed on the proximal end side of the shaft portion, and the male screw portion until the tip end surface of the shaft portion contacts the outer surface of the first connecting wall. The portable power brush cutter according to claim 1 or 2 , wherein a spring member is interposed between the head and the outer surface of the second connecting wall in a state of being screwed into the screw hole.

An operation tube, a transmission shaft inserted through the operation tube, and a rotary blade supported via a rotary blade support member provided at the tip of the operation tube, the rotational output of the power source is transmitted to the transmission shaft A portable power brush cutter configured to transmit to the rotary blade via the rotary blade and rotate the rotary blade,
The rotary blade support member includes an input shaft to which the tip of the transmission shaft is coupled, and a rotary blade mounting shaft that is linked to the input shaft via a bevel gear mechanism. It is supported with respect to the operation tube so that it can rotate stepwise around a horizontal axis perpendicular to the axis of the tube ,
A first connecting member is provided at the tip of the operation tube, and a second connecting member is provided on the rotary blade support member. The first connecting member and the second connecting member are The first connecting member and the second connecting member are pivotally connected around the horizontal axis, and are formed with conductive shaft insertion holes through which the transmission shaft is inserted in a penetrating manner. ,
One of the first connecting member and the second connecting member is formed with a pair of first connecting walls facing each other with the transmission shaft interposed therebetween, and the other of the first connecting member and the second connecting member. Are formed with a pair of second connection walls in contact with the outer surfaces of the pair of first connection walls, and each of the first connection walls and the second connection walls located across the transmission shaft are in the thickness direction thereof. Are connected to each other by screw members corresponding to the transverse axis, and
The portable power brush cutter, wherein at least a portion of the transmission shaft from the distal end portion of the operation tube to the rotary blade support member has flexibility.

5. The portable power according to claim 4 , wherein the transmission shaft insertion holes respectively formed in the first connecting member and the second connecting member have a tapered shape that generally increases in vertical width as approaching the lateral axis. Brush cutter.

Between the connection first member or a member integral therewith and the connection second member or a member integral therewith, the connection second member to the connection first member or a member integral with the connection second member or The portable power according to claim 4 or 5 , wherein a stage locking mechanism is provided that can be locked at every predetermined rotation angle when the member is integrated with the horizontal axis about the horizontal axis. Brush cutter.

The stage locking mechanism may include a plurality of the first locking member or a member integral with the connecting first member or the second connection member or the member integral therewith along an arc centered on the lateral axis. While the engagement recess is formed, the other of the connection first member or the member integrated with the connection second member or the member integrated with the connection first member is elastic toward the surface where the engagement recess is formed. The portable power brush cutter according to claim 6 , wherein the portable power brush cutter is formed by providing a biased engagement member.

The step locking mechanism may include a plurality of the first locking member or a member integral with the connecting first member or the second connection member or the member integral therewith along an arc centered on the lateral axis. While the engagement recess is formed, the other of the connection first member or the integral member and the connection second member or the integral member is attached to the other surface of the engagement recess. provided with an engagement member that is energized, the engaging member by the operation of the operator, and is configured to be retracted from forcefully the engaging recess against the biasing force, claim 6 A portable power brush cutter according to claim 1.