JP3663242B2

JP3663242B2 - Cutting device capable of round cutting and holding device for round cutting

Info

Publication number: JP3663242B2
Application number: JP30054995A
Authority: JP
Inventors: 甫夫片岡
Original assignee: 片岡ます美; 片岡磨紀; 片岡寛之
Priority date: 1995-10-24
Filing date: 1995-10-24
Publication date: 2005-06-22
Anticipated expiration: 2015-10-24
Also published as: JPH09117901A

Description

【０００１】
【発明の属する技術分野】
本発明は、被切削材が載置されるテーブルを有し、鋸歯を用いて、木材，鉄板等の金属板、プラスチック材等を、円切りする切断装置および切断装置に用いてる円切り用の保持装置に関する。
【０００２】
【従来の技術】
従来、糸鋸盤などの切断装置で円盤などを切断することを目的として、円切り用の保持装置を備えたものが知られている。こうした切断装置では、切断装置の平面図である図１２に示すように、被切削材の送り方向をｙ軸、これに直交する方向をｘ軸とすると、糸鋸歯の中心からｘ軸方向に、円切りしよとする円盤の半径だけ隔たった位置に、被切削材を保持する保持装置を備える。例えば、木材を円形に切り落とす場合には、保持装置として針ＮＤを設け、板材ＷＷをこの針に押しつけて、針ＮＤを中心に回転可能に保持させる。糸鋸歯ＴＴを駆動して板材ＷＷを針を中心に回転させれば、糸鋸歯ＴＴにより、板材ＷＷが、半径Ｒで円切りされることになる。
【０００３】
【発明が解決しようとする課題】
しかしながら、実際にこの切断装置で、板材の円切りを行なってみると、切削の軌跡は真円から無視し得ないほど外れ、板材ＷＷが一周した時に、切削開始の位置に戻らないことさえ珍しくない。これは被切削材の材質を問わず、木材、プラスチック、金属板など、いずれの材料を円切りする場合にも生じる。こうしたずれが生じるのは、糸鋸歯に厚みと切削方向の長さとがあり、この長さ分だけ直線的に被切削材を切断して行こうとするのに対して、板材が回転運動するため、切削の箇所では板材に対して、鋸歯がｘ軸方向（径方向）に逃げようとする力が働くためと考えられる。従来、こうした問題に配慮した円切り装置はなく、糸鋸盤等の切断装置で円切りしたものは、真円の円盤としては到底扱えないものとされていた。
【０００４】
本発明は、上記問題点を解決するためになされ、糸鋸盤等の切断装置において、円切りの径によらず、ほぼ真円の切り出しを行なえるものとすることを目的とする。
【０００５】
【課題を解決するための手段およびその作用・効果】
かかる課題を解決するため、本発明の第１の切断装置は、
板状の被切削材が載置されるテーブルを有し、糸鋸歯により該被切削材を切断する切断装置であって、
前記テーブル上に設けられ、円切りを行なおうとする被切削材を所定の回転中心において回転自在に保持する保持手段を設けると共に、
該保持手段の該中心位置を、
円切りの半径が１５０ミリ以下の範囲において、前記糸鋸歯による切断の実施位置を原点とし前記被切削材の送り方向をｙ軸、これに直交する方向をｘ軸として、（ｘ，ｙ）＝（３０，６１９）［単位ミリ］をおおよその中心点とし、前記糸鋸歯による切断の実施位置を通る円弧上の範囲に配置することにより、
前記被切削材の円切りの半径が略６０ミリ以下では、前記糸鋸歯の中心より該被切削材の送り方向手前側における前記円弧上に位置せしめ、
前記被切削材の円切りの半径が略６０ミリを越えれば、前記糸鋸歯の中心より該被切削材の送り方向向こう側における前記円弧上に位置せしめたこと
を要旨としている。
また、本発明の第２の切断装置は、
板状の被切削材が載置されるテーブルを有し、糸鋸歯により該被切削材を切断する切断装置であって、
前記テーブル上に設けられ、円切りを行なおうとする被切削材を所定の回転中心において回転自在に保持する保持手段を設けると共に、
該保持手段の該中心位置を、
前記糸鋸歯による切断の実施位置を原点とし前記被切削材の送り方向をｙ軸、これに直交する方向をｘ軸とし、円切りの半径をｒ［ミリ］としたとき、少なくとも半径１５０ミリ以下の円切りにおいては、次の直線と円との前記原点以外の交点の軌跡範囲に設けると共に、
直線ｙ＝ｔａｎ｛α・（ｒ−６０）／１０｝・ｘ
α≒０．４〜０．５
円（ｘ−ｒ／２） ² ＋ｙ ² ＝（ｒ／２） ²
前記被切削材の円切りの半径が所定値以下である場合には、前記糸鋸歯の中心より該被切削材の送り方向手前側における前記軌跡上に位置せしめ、
前記被切削材の円切りの半径が前記所定値を越える場合には、前記糸鋸歯の中心より該被切削材の送り方向向こう側における前記軌跡上に位置せしめたこと
を要旨としている。
【０００６】
これらの切断装置は、保持手段により被切削材を保持して円切りを行なうが、その際、円切りの半径によって、回転中心を、糸鋸歯の中心から、被切削材の送り方向手前側と向こう側に変位して位置せしめる。この結果、円切りの半径が小さいものにおいて見られた真円からの外側へのずれや、円切りの半径が大きなものにおいて見られた真円からの内側へのずれが解消され、円切りにおける切り出しの軌跡を真円に近づけることができる。また、上記第２の切断装置のようにして回転中心を求めるのは、様々な材料に対して円切りがほぼ真円となる入角を求めた結果である。発明者が、半径１０ミリの円盤を略真円で円切りするための入角を求めたところ、略２．５度を適正な入角として得た。次に入角が０度となる半径を求めたところ６０ミリであった。そこで、半径が１０ミリ増加する度に入角が０．５度小さくなると言う仮定の下に、保持手段の中心位置を求めたのが、上記式である。この式に従って回転中心を求め、種々の寸法で円切りを行なったところ、極めて良好な真円に近い円切りが可能であった。回転中心を、鋸歯の中心を通る線上（ｘ軸上）においたので、円切りの軌跡は、真円からはかけ離れてしまう。なお、直線の角度αは望ましくは０．４６度である。
【０００７】
これらの切断装置において、円切りの軌跡を真円に近づけるために、回転中心を、被切削材の送り方向手前側と向こう側に分ける円切りの半径の所定値は、被切削材が、木材，鉄板等の板材の場合には、略６０ミリとなることが分かった。略６０ミリ以下の場合には、回転中心を送り方向手前側とし、略６０ミリを越える場合には回転中心を送り方向向こう側とするのである。特殊な材料を切断する場合には、最適な値を実験的に求めればよい。
【００１０】
更に、上記各構成において、保持手段の回転中心を、連続的に移動可能な移動機構を有するものとすることも好適である。この場合には、何ミリの径の円盤でも切り出すことができる。
【００１１】
以上、切断装置について説明したが、本発明は円切り用保持装置単体でも実現可能である。即ち、既存の糸鋸盤等に後付け可能な円切り用保持装置として構成することができる。
本発明の第１の円切り用保持装置は、板状の被切削材が載置されるテーブルを有し、糸鋸歯により該被切削材を切断する切断装置に設けられ、該被切削材を回転自在に保持する円切り用保持装置であって、
前記回転の中心位置を、
円切りの半径が１５０ミリ以下の範囲において、前記糸鋸歯による切断の実施位置を原点とし前記被切削材の送り方向をｙ軸、これに直交する方向をｘ軸として、（ｘ，ｙ）＝（３０，６１９）［単位ミリ］をおおよその中心点とし、前記糸鋸歯による切断の実施位置を通る円弧上の範囲に配置することにより、
前記被切削材の円切りの半径が略６０ミリ以下であれば、前記糸鋸歯の中心より該被切削材の送り方向手前側における前記円弧上に位置せしめ、
前記被切削材の円切りの半径が略６０ミリを越えれば、前記糸鋸歯の中心より該被切削材の送り方向向こう側における前記円弧上に位置せしめたこと
を要旨としている。
また、本発明の第２の円切り用保持装置は、板状の被切削材が載置されるテーブルを有し、糸鋸歯により該被切削材を切断する切断装置に設けられ、該被切削材を回転自在に保持する円切り用保持装置であって、
前記回転の中心位置を、
前記糸鋸歯による切断の実施位置を原点とし前記被切削材の送り方向をｙ軸、これに直交する方向をｘ軸とし、円切りの半径をｒ［ミリ］としたとき、少なくとも半径１５０ミリ以下の円切りにおいては、次の直線と円との前記原点以外の交点の軌跡範囲に設けると共に、
直線ｙ＝ｔａｎ｛α・（ｒ−６０）／１０｝・ｘ
α≒０．４〜０．５
円（ｘ−ｒ／２） ² ＋ｙ ² ＝（ｒ／２） ²
前記被切削材の円切りの半径が所定値以下である場合には、前記糸鋸歯の中心より該被切削材の送り方向手前側における前記軌跡上に位置せしめ、
前記被切削材の円切りの半径が前記所定値を越える場合には、前記糸鋸歯の中心より該被切削材の送り方向向こう側における前記軌跡上に位置せしめたこと
を要旨としている。
【００１２】
かかる保持装置によれば、真円に近い軌跡を可能とする糸鋸歯に対する入角を実現するから、この保持装置によって保持すれば、ほぼ真円の円切りを実現することができる。
【００１３】
ここで、糸鋸歯の中心を通る線よりずらす場合で、手前側か向こう側かを分かつ所定値は、被切削材が、木材，鉄板等の板材の場合には、略６０ミリである。
【００１６】
上述した円切り用保持装置において、回転中心を、連続的に移動可能な移動機構を有するものとすることも好適である。なお、角度αは、望ましくは０．４６度である。
【００１７】
本発明の上記の切断装置あるいは円切り用保持装置において、保持手段は、被切削材に突き刺さり該被切削材を前記回転中心で回転自在に保持する針、被切削材を負圧により吸着し該被切削材を前記回転中心で回転自在に保持する負圧吸着機構、または被切削材を磁気的に吸着し該被切削材を前記回転中心で回転自在に保持する磁気吸着機構のうちの少なくとも一つとすることができる。こうした構成を取ることにより、木材，金属板，プラスチック，ガラスなど多様な材料を円切りすることが可能となる。
【００１８】
【発明の実施の形態】
次に、本発明に係る切断装置および円切り用保持装置の実施の形態を実施例に基づき説明する。切断装置の例として、糸鋸盤を用いて説明する。糸鋸盤１０は、図１の概略斜視図，図２の正面図および図３の側面図に示すように、板材等の被切削材が載置されるテーブル１２をその上面に有する本体１４と、この本体１４の中央後部上面から立ち上げ設置されたアーム１６とを有する。アーム１６は、本体１４から立設した基部１６ａと当該基部から屈曲したアーム部１６ｂとを有し、このアーム部１６ｂをテーブル１２に対向させている。なお、このアーム部１６ｂには、その略中央に糸鋸盤１０の運搬時に把持される把手部１６ｃが形成されている。
【００１９】
こうして対向するアーム１６のアーム部１６ｂとテーブル１２との間には、糸鋸歯ＮＢがテーブル１２を貫通して配置されている。この糸鋸歯ＮＢは、その上端がアーム部１６ｂに収納された後述の上端保持機構で保持され、下端が本体１４内に収納された後述の下端保持機構で保持されている。そして、テーブル１２に対して上下動する糸鋸歯ＮＢにより、テーブル１２上の被切削材は切断される。
【００２０】
上記した本体１４とアーム１６は、例えば機械的強度が比較的高いＡＢＳ等の樹脂を用いた樹脂成形品であり、一体成形されている。この場合、本体１４とアーム１６は、図２における垂直方向の中心線を境に左右に分割した形状の左側本体および左側アームと右側本体および右側アームとを接合・固定することで形成され、内部の空間に後述の種々の部材を収納する。そして、テーブル１２は、このように形成された本体１４の上面の凹所に嵌め込まれ、本体１４の一部となる。なお、左側本体，右側本体および左側アーム，右側アームは、その適宜箇所にリブを設けることで補強されていることは勿論である。
【００２１】
また、糸鋸盤１０は、糸鋸歯ＮＢをその背面にてガイドするためのガイド機構２０をアーム部１６ｂから保持パイプ２６により垂下して備える。このガイド機構２０は、アーム部１６ｂ側面の調節ノブ１７によりその上下位置が調整され、調整後の位置に固定される。なお、ガイド機構２０のガイドブロック２１には、切り粉集塵用の吸引口２１ａが設けられており、この吸引口２１ａは、本体１４の背面に設けられた集塵用接続口６０に連通している。この集塵用接続口６０に家庭用電気掃除機を取り付けて運転すると、糸鋸歯ＮＢによる切削で生じた切り粉は、ガイド機構２０の吸引口２１ａから電気掃除機に集塵される構成となっている。
【００２２】
更に、糸鋸盤１０は、アーム１６の基部１６ａの左右側面に、糸鋸盤１０の駆動源である本体１４内蔵のモータをオン・オフするための操作ノブ１８と、切粉除去のために駆動する電気掃除機（図１１参照）をオン・オフするための切粉除去ノブ１９とを有する。また、アーム部１６ｂの先端面には、糸鋸盤１０に電源が投入されると点灯する運転ランプ１５が組み込まれている。
【００２３】
糸鋸歯ＮＢは、アーム１６の内部に設けられた上端保持機構、およびテーブル１２下部の本体１４内に設けられた下端保持機構により、所定の張力を受けて保持され、更に本体１４に内蔵された図示しない駆動機構により、モータを駆動源として、所定のストロークで上下に駆動される。糸鋸歯ＮＢを上下に駆動する機構については、公知のものなので詳細な説明は省略する。
【００２４】
次に、テーブル１２上に取りつけられた円切り用保持機構３０について説明する。テーブル１２には、４カ所に取り付け用のネジ孔が設けられており、円切り用保持機構３０の円切りテーブル３２は、埋め込みタイプのネジにより、テーブル１２に固定されている。この円切りテーブル３２には、図示するように、円弧上のガイド孔３５が設けられており、ここには、円切り用の保持部材４０が移動可能にはめ込まれている。円切りテーブル３２の向かって右側には、この保持部材４０を載置したガイド４４が延出されており、このガイド４４の端部を操作することで、保持部材４０は、ガイド孔３５に沿って自由に移動することができる。保持部材４０は、ガイド孔３５内を滑らかに移動するよう円形をしており、その中心には、針４１が上向きに固定されている。ガイド４４には、図４に示すように、ガイド孔３５とほぼ同形の円弧形状の固定孔４６が、ガイド孔３５に沿った保持部材４０の動きを補償するように、逆向きに設けられており、この固定孔４６を通して固定ネジ５０を、円切りテーブル３２の裏面に設けられたネジ孔に螺合することにより、ガイド４４を所望の位置で固定することができる。
【００２５】
ガイド孔３５の詳細を図５に示す。図示するように、ガイド孔３５の周囲には、１ミリピッチで寸法が刻まれており、これに保持部材４０の針４１の中心を併せることにより、円切りの半径を容易に設定することができる。このガイド孔３５は、糸鋸歯ＮＢが貫通する貫通孔１２ａの中心から１０ミリ隔たった位置を一端とし、円切り半径１５０ミリを他端とする大きな円弧形状に形成されている。より詳しくは、このガイド孔３５の中心は、糸鋸歯ＮＢの位置を原点（０，０）とし、被切削材の送り方向をＹ軸方向、これに直交する方向をＸ軸方向とするとき、点（３０，６１９）を中心とし、原点（０，０）および点（６０，０）を通る円弧の一部として形成されている。
【００２６】
したがって、円切りの半径が６０ミリ以下では、保持部材４０の針４１、即ち針４１により回転自在に保持された被切削材の回転中心は、Ｘ軸を基準線とすると、被切削材の送り方向手前側に位置し、円切りの半径が６０ミリを越える場合には、被切削材の送り方向向こう側に位置することになる。なお、糸鋸歯ＮＢはＹ軸方向に所定の長さを有するが、本実施例では、Ｙ軸方向の原点は、正確には、糸鋸歯ＮＢの歯の谷の位置としている。
【００２７】
次に、この円弧をいかにして特定したかについて説明する。発明者は、従来の回転中心が図５Ｘ軸上を移動する糸鋸盤での円切りが、理屈上では真円になるはずであるにもかかわらず、実際は真円から大きくかけ離れてしまう点について検討し、糸鋸歯ＮＢが被切削材の送り方向に対して長さを持たない理論上の切削点ではなく、実際には長さを持つことに着目した。従って、被切削材は、糸鋸歯ＮＢから、被切削材の円切りにおける半径方向の力を、その切削に伴って受け、径方向にゆがむことになる。様々な検討と試行の後に、発明者は、こうした力の発生を解消するためには、糸鋸歯ＮＢの被切削材に対する切削開始の角度（以下、入角βと呼ぶ）を適正に調整すればよいのではないかという着想に至った。発明者は、円切りの半径を変えて入角を調整し、暫定値として半径１０ミリ（φ２０）の円切りでは、約２．５度が望ましいことを見いだした。円切りの半径が大きくなるほど、入角は鈍角となる。具体的には、円切りの半径が１０ミリ大きくなる毎に、入角は約０．５度ずつ小さくすることが望ましい。そこで、発明者は更に検討を重ね、ほぼ真円が得られる円切りの中心位置（被切削材を保持する回転中心の位置）が、次式（１）の直線と、次式（２）の円の原点以外の交点として得られることを見いだした。なお、入角β＝α・（ｒ−６０）／１０である。
【００２８】

【００２９】
α＝０．５度とした場合、式（１）の直線と式（２）の円との交点のうち原点以外の交点の軌跡を、ｒを変数として求めると、中心位置（３０，５７３）、半径５７３．８ミリの近似的な円弧となった。発明者は、α＝０．５として、ガイド孔３５を設計し、テストを行なったところ、半径３０ないし４０ミリでの円切りでは真円から僅かに外れた結果となることを見いだした。そこで、更に検討を繰り返した結果、ガイド孔３５の円弧の中心を（３０，６１９）とした場合に、おおむね最良の結果が得られることを見いだした。この結果から逆算すると、上記式（１）の角度αは０．４６度となった。もとよりこれらは糸鋸歯ＮＢの幅や被切削材の材質によってもある程度の影響は受けるものと推定される。また、角度αを０．５としても、従来の円切り装置により得られる円とは、比較にならないほど精度の良い円切りがなされるから、実用上は、α≒０．４〜０．５としても何等差し支えない。
【００３０】
図６ないし図８を用いて、本実施例の円切り用保持機構３０による円切りの実際について説明する。図６は、被切削材として木材の板材ＷＷを用い、半径４０ミリ（φ８０）の円切りを行なう場合の模式図である。この場合には、式（１）および式（２）を満たす入角β１は、０．９２度となり、保持部材４０の針４１の中心位置Ｐ１は、理論上は、（３９．９９，−０．６４）となる。なお、数式の展開は、省略するが、上記式（１）および式（２）の原点以外の交点の座標（ｘ，ｙ）は、Ａ＝ｔａｎβとすると、
ｘ＝ｒ／（１＋Ａ²）
ｙ＝Ａ・ｒ／（１＋Ａ²）
として求められる。
【００３１】
ガイド孔３５の目盛りに針４１を合わせる場合には、せいぜい小数点以下一桁程度の精度しか出せないが、それでも円切りの結果得られた外形線Ｒ１は、旋盤で切削しても加工屑が出ないほどの真円となった。また、図７は、同じ板材ＷＷを用い、半径６０ミリ（φ１２０）の円切りを行なう場合の模式図である。この場合には、式（１）および式（２）を満たす入角は０度となり、保持部材４０の針４１の中心位置Ｐ２は、（６０，０）となった。更に図８は、同じく板材ＷＷを用い、半径１２０ミリ（φ２４０）の円切りを行なう場合の模式図である。この場合には、式（１）および式（２）を満たす入角β２は、−２．７６度となり、保持部材４０の針４１の中心位置Ｐ３は、（１１９．７２，５．７７）となった。円切りの結果得られた外形線Ｒ２、Ｒ３は、いずれも旋盤で切削しても加工屑が出ないほどの真円であった。
【００３２】
以上の説明では、被切削材として木材の板材ＷＷを例にしたが、金属板（鉄、アルミ、銅板など）でもプラスチックでも、同様に正確な円切りを行なうことができた。金属板の場合には、針４１によって回転自在に保持することはできないから、こうした場合には、図９に示すように、ガイド４４ａに磁石４７を回転自在に取りつけたものを保持手段として用いればよい。また、金属板やプラスチックの場合には、図１０に示すように、ガイド４４ｂに吸盤４８を回転自在に取りつけたものを用いることも可能である。また、円切り専用機として糸鋸盤１０を構成する場合には、保持部材４０を固定とすることも差し支えない。更に、円切り用の保持手段を円切りテーブル３２上に設ける代わりに、アーム１６側から設ける構成とすることも可能である。
【００３３】
以上本実施例における円切り用保持機構３０の構成について明らかにしたが、糸鋸盤１０としての残余の構成について補足する。この糸鋸盤１０の電気系を図１１に示す。糸鋸盤１０は、図示するように、糸鋸盤１０自体の鋸盤用電源回路７０と、電気掃除機に電源を供給するための掃除機用電源回路７５とを備える。鋸盤用電源回路７０は、壁等に既設済みの図示しないコンセントに差し込まれる電源プラグ７１を備え、回路中に設けられたメインスイッチ７２によりモータＭに電源を投入する。このメインスイッチ７２は、アーム１６に設けられた操作ノブ１８（図１，図２参照）の回動操作に連動して接点をオン・オフし、鋸盤用電源回路７０を開閉する。また、この鋸盤用電源回路７０には、モータＭと並列に運転ランプ１５が組み込まれている。このため、操作ノブ１８がオン側に回動操作されると、メインスイッチ７２により回路が閉じられてモータＭが駆動すると共に運転ランプ１５が点灯する。これにより、糸鋸歯ＮＢが上下動し被切削材の切断ができる状態となる。なお、鋸盤用電源回路７０には、ヒューズ７３が組み込まれている。また、モータＭと並列にサージ制限コンデンサ７４が設置されており、落雷等に伴うサージ電圧によるモータＭの損傷回避が図られている。
【００３４】
掃除機用電源回路７５は、上記の鋸盤用電源回路７０と並列に設けられており、電気掃除機の電源プラグが挿入されるコンセント６３を備え、回路中に設けられた掃除機スイッチ７６により、このコンセント６３を経て電気掃除機に電源を投入する。この掃除機スイッチ７６は、アーム１６に設けられた切粉除去ノブ１９（図２参照）の回動操作に連動して接点をオン・オフし、掃除機用電源回路７５を開閉する。このため、切粉除去ノブ１９がオン側に回動操作されると、掃除機スイッチ７６により回路が閉じられて電気掃除機が駆動し、既述したガイドブロック２１に設けられた吸引孔２１ａおよび貫通孔１２ａを介して、切粉が吸引され、集塵が行なわれる。
【００３５】
以上、本発明の実施の態様について説明したが、本発明はこうした態様に限られるものではなく、本発明の要旨を逸脱しない範囲において、種々なる態様で実施することができる。例えば、糸鋸盤以外のバンドソーなどの切断装置に適用することも可能である。また、保持手段による被切削材の回転中心を、切断位置の向かって左側に配置することも差し支えない。
【図面の簡単な説明】
【図１】実施例の糸鋸盤１０の概略斜視図である。
【図２】この糸鋸盤１０の正面図である。
【図３】糸鋸盤１０の側面図である。
【図４】保持部材４０とこれを取りつけたガイド４４の構造を示す斜視図である。
【図５】ガイド孔３５の詳細を示す平面図である。
【図６】半径４０（φ８０）の円切りを行なう様子を示す模式図である。
【図７】半径６０（φ１２０）の円切りを行なう様子を示す模式図である。
【図８】半径１２０（φ２４０）の円切りを行なう様子を示す模式図である。
【図９】保持部材として磁石４７を用いた例を示す斜視図である。
【図１０】保持部材として吸盤４８を用いた例を示す斜視図である。
【図１１】糸鋸盤１０の電気的な構成を示す回路図である。
【図１２】従来の円切り装置を用いた円切りの様子を示す説明図である。
【符号の説明】
１０…糸鋸盤
１２…テーブル
１２ａ…貫通孔
１４…本体
１５…運転ランプ
１６…アーム
１６ａ…基部
１６ｂ…アーム部
１６ｃ…把手部
１７…調節ノブ
１８…操作ノブ
１９…切粉除去ノブ
２０…ガイド機構
２１…ガイドブロック
２１ａ…吸引孔
３０…円切り用保持機構
３２…円切りテーブル
３５…ガイド孔
４０…保持部材
４１…針
４４…ガイド
４４ａ…ガイド
４４ｂ…ガイド
４６…固定孔
４７…磁石
４８…吸盤
５０…固定ネジ
６３…コンセント
７０…鋸盤用電源回路
７１…電源プラグ
７２…メインスイッチ
７３…ヒューズ
７４…サージ制限コンデンサ
７５…掃除機用電源回路
７６…掃除機スイッチ
Ｍ…モータ
ＮＢ…糸鋸歯
Ｐ１〜Ｐ３…中心位置
ＴＴ…糸鋸歯
ＷＷ…板材
α…角度
β１…入角
β２…入角[0001]
BACKGROUND OF THE INVENTION
The present invention has a table on which a material to be cut is placed, and uses a saw blade to cut a metal plate such as wood or an iron plate, a plastic material, etc. into a cutting device and a cutting device for cutting into a circular device. The present invention relates to a holding device.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a device provided with a holding device for cutting a circle is known for the purpose of cutting a disk or the like with a cutting device such as a yarn saw. In such a cutting device, as shown in FIG. 12, which is a plan view of the cutting device, if the feed direction of the workpiece is the y-axis and the direction orthogonal to this is the x-axis, A holding device for holding the workpiece is provided at a position separated by the radius of the disk to be cut. For example, when cutting wood into a circle, a needle ND is provided as a holding device, and the plate material WW is pressed against the needle to hold it rotatably about the needle ND. When the thread saw tooth TT is driven to rotate the plate material WW around the needle, the plate material WW is cut into a circle with a radius R by the thread saw tooth TT.
[0003]
[Problems to be solved by the invention]
However, when actually cutting the plate material with this cutting device, the cutting locus deviates from a perfect circle so that it is not negligible, and when the plate material WW goes around, it is rarely returned to the cutting start position. Absent. This occurs when cutting any material such as wood, plastic, or metal plate regardless of the material of the workpiece. This deviation occurs because the saw blade has a thickness and a length in the cutting direction, and the plate material rotates while the material to be cut is linearly cut by this length. This is considered to be due to the fact that the saw blade acts to escape in the x-axis direction (radial direction) on the plate material at the cutting site. Conventionally, there has been no circular cutting device that takes these problems into consideration, and a device that has been cut by a cutting device such as a yarn saw machine cannot be handled as a perfect circular disk.
[0004]
The present invention has been made to solve the above-described problems, and an object of the present invention is to enable cutting of a perfect circle regardless of the diameter of a circular cutting in a cutting device such as a yarn saw.
[0005]
[Means for solving the problems and their functions and effects]
In order to solve such a problem, the first cutting device of the present invention includes:
A cutting device having a table on which a plate-like workpiece is placed, and cutting the workpiece with a saw blade,
Provided with a holding means that is provided on the table and holds a workpiece to be cut circularly at a predetermined rotation center, and
The central position of the holding means is
When the radius of the circular cutting is in the range of 150 mm or less, assuming that the cutting position by the saw blade is the origin, the feed direction of the workpiece is the y axis, and the direction orthogonal to this is the x axis, (x, y) = By placing (30,619) [unit mm] as an approximate center point and placing it in a range on an arc passing through the cutting position of the saw blade,
When the radius of the cut of the workpiece is approximately 60 mm or less, it is positioned on the arc on the front side in the feed direction of the workpiece from the center of the saw blade ,
The gist is that if the radius of the cut of the workpiece exceeds about 60 mm, the workpiece is positioned on the arc on the side of the workpiece in the feed direction from the center of the saw blade .
The second cutting device of the present invention is
A cutting device having a table on which a plate-like workpiece is placed, and cutting the workpiece with a saw blade,
Provided with a holding means that is provided on the table and holds a workpiece to be cut circularly at a predetermined rotation center, and
The central position of the holding means is
When the cutting position by the saw blade is the origin, the feed direction of the material to be cut is the y-axis, the direction orthogonal thereto is the x-axis, and the radius of the circular cutting is r [mm], at least a radius of 150 mm or less In the circle cutting of, provided in the locus range of the intersection of the next straight line and the circle other than the origin,
Straight line y = tan {α · (r−60) / 10} · x
α ≒ 0.4 ~ 0.5
Circle (x−r / 2) ² + y ² = (r / 2) ²
When the cutting radius of the workpiece is equal to or less than a predetermined value, the workpiece is positioned on the locus on the front side in the feed direction of the workpiece from the center of the saw blade,
When the radius of the cut of the workpiece exceeds the predetermined value, it is positioned on the locus on the side of the workpiece in the feed direction from the center of the saw blade.
Is the gist.
[0006]
These cutting devices hold the workpiece by a holding means and perform circular cutting. At this time, the center of rotation is changed from the center of the saw blade to the front side in the feed direction of the workpiece by the radius of the circular cutting. Displace to the other side. As a result, the deviation from the perfect circle seen in the one with a small rounding radius and the deviation from the perfect circle seen in the one with a large rounding radius are eliminated, The cutting locus can be made close to a perfect circle. The reason for obtaining the center of rotation as in the case of the second cutting device is the result of obtaining the entrance angle at which the circular cutting is almost a perfect circle for various materials. When the inventor obtained an angle of entry for cutting a disk having a radius of 10 mm with a substantially perfect circle, the angle of about 2.5 degrees was obtained as an appropriate angle. Next, the radius at which the incident angle was 0 degrees was determined to be 60 mm. Therefore, the above formula is obtained for the center position of the holding means under the assumption that the incident angle is reduced by 0.5 degrees every time the radius increases by 10 mm. When the center of rotation was obtained according to this equation and cut into various dimensions, it was possible to cut an extremely good perfect circle. Since the center of rotation is on a line (on the x axis) passing through the center of the saw blade, the locus of the circular cut is far from the perfect circle. The straight line angle α is desirably 0.46 degrees.
[0007]
In these cutting devices, in order to make the trajectory of circular cutting closer to a perfect circle, the predetermined value of the radius of the circular cutting that divides the center of rotation into the front side and the other side in the feed direction of the cutting material is that the cutting material is wood In the case of a plate material such as an iron plate, it was found to be approximately 60 mm. In the case of approximately 60 mm or less, the center of rotation is the front side in the feed direction, and in the case of approximately 60 mm or more, the center of rotation is the other side in the feed direction. When cutting a special material, an optimum value may be obtained experimentally.
[0010]
Furthermore, in each of the above-described configurations, it is also preferable to have a moving mechanism capable of continuously moving the rotation center of the holding means. In this case, a disk having a diameter of several millimeters can be cut out.
[0011]
Although the cutting device has been described above, the present invention can also be realized with a single circular cutting holding device. That is, it can be configured as a holding device for circular cutting that can be retrofitted to an existing yarn saw or the like.
A first circular cutting holding device of the present invention includes a table on which a plate-shaped workpiece is placed, and is provided in a cutting device that cuts the workpiece with a thread saw tooth. A holding device for circular cutting that holds freely,
The center position of the rotation is
When the radius of the circular cutting is in the range of 150 mm or less, assuming that the cutting position by the saw blade is the origin, the feed direction of the workpiece is the y axis, and the direction orthogonal to this is the x axis, (x, y) = By placing (30,619) [unit mm] as an approximate center point and placing it in a range on an arc passing through the cutting position of the saw blade,
If the radius of the cut of the workpiece is approximately 60 mm or less, it is positioned on the arc on the front side in the feed direction of the workpiece from the center of the saw blade ,
The gist is that if the radius of the cut of the workpiece exceeds about 60 mm, the workpiece is positioned on the arc on the side of the workpiece in the feed direction from the center of the saw blade .
Further, the second device for holding a circular cut of the present invention has a table on which a plate-shaped workpiece is placed, and is provided in a cutting device that cuts the workpiece with a saw blade, and the workpiece A holding device for circular cutting that holds a material rotatably,
The center position of the rotation is
When the cutting position by the saw blade is the origin, the feed direction of the material to be cut is the y-axis, the direction orthogonal thereto is the x-axis, and the radius of the circular cutting is r [mm], at least a radius of 150 mm or less In the circle cutting of, provided in the locus range of the intersection of the next straight line and the circle other than the origin,
Straight line y = tan {α · (r−60) / 10} · x
α ≒ 0.4 ~ 0.5
Circle (x−r / 2) ² + y ² = (r / 2) ²
When the cutting radius of the workpiece is equal to or less than a predetermined value, the workpiece is positioned on the locus on the front side in the feed direction of the workpiece from the center of the saw blade,
When the radius of the cut of the workpiece exceeds the predetermined value, it is positioned on the locus on the side of the workpiece in the feed direction from the center of the saw blade.
Is the gist.
[0012]
According to such a holding device, an entry angle with respect to the saw blade that enables a locus close to a perfect circle is realized. Therefore, if this holding device is used, a substantially circular cutting can be realized.
[0013]
Here, in the case of shifting from the line passing through the center of the saw blade , whether the front side or the other side is separated, the predetermined value is approximately 60 mm when the material to be cut is a plate material such as wood or iron plate.
[0016]
In the above-described circular cutting holding device, it is also preferable to have a moving mechanism capable of continuously moving the rotation center. Note that the angle α is preferably 0.46 degrees.
[0017]
In the above-described cutting device or holding device for cutting a circle according to the present invention, the holding means pierces the material to be cut and adsorbs the material to be cut by a negative pressure by holding the material to be cut freely at the rotation center. At least one of a negative pressure adsorption mechanism that holds the workpiece to be rotated at the rotation center or a magnetic adsorption mechanism that magnetically attracts the workpiece and holds the workpiece at the rotation center. It can be one. By adopting such a configuration, it is possible to cut various materials such as wood, metal plates, plastics and glass.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Next, an embodiment of a cutting device and a circular cutting holding device according to the present invention will be described based on examples. An example of the cutting device will be described using a yarn saw. As shown in the schematic perspective view of FIG. 1, the front view of FIG. 2, and the side view of FIG. 3, the yarn saw machine 10 includes a main body 14 having a table 12 on which an object to be cut such as a plate material is placed, It has an arm 16 raised from the central rear upper surface of the main body 14. The arm 16 has a base portion 16 a erected from the main body 14 and an arm portion 16 b bent from the base portion, and the arm portion 16 b is opposed to the table 12. The arm portion 16b is formed with a handle portion 16c that is gripped when the yarn saw 10 is transported at the approximate center thereof.
[0019]
Thus, a saw blade NB is disposed through the table 12 between the arm portion 16 b of the arm 16 and the table 12 facing each other. The upper end of the thread saw tooth NB is held by an upper end holding mechanism (described later) housed in the arm portion 16 b, and the lower end is held by a lower end holding mechanism (described later) housed in the main body 14. Then, the material to be cut on the table 12 is cut by the thread saw teeth NB that move up and down with respect to the table 12.
[0020]
The main body 14 and the arm 16 described above are resin molded products using, for example, a resin such as ABS having a relatively high mechanical strength, and are integrally molded. In this case, the main body 14 and the arm 16 are formed by joining and fixing the left main body and the left arm, and the right main body and the right arm, which are divided into left and right with the vertical center line in FIG. Various members described later are accommodated in the space. Then, the table 12 is fitted into a recess on the upper surface of the main body 14 formed in this way, and becomes a part of the main body 14. Of course, the left main body, the right main body, the left arm, and the right arm are reinforced by providing ribs at appropriate positions.
[0021]
In addition, the yarn saw machine 10 includes a guide mechanism 20 for guiding the yarn saw tooth NB on the back surface thereof by being suspended from the arm portion 16b by a holding pipe 26. The guide mechanism 20 is adjusted in its vertical position by the adjustment knob 17 on the side of the arm portion 16b, and is fixed to the position after adjustment. The guide block 21 of the guide mechanism 20 is provided with a suction port 21a for collecting dust, and this suction port 21a communicates with a dust collection connection port 60 provided on the back surface of the main body 14. ing. When the household vacuum cleaner is attached to the dust collection connection port 60 and operated, the chips generated by cutting with the saw blade NB are collected by the vacuum cleaner from the suction port 21a of the guide mechanism 20. ing.
[0022]
Further, the yarn saw 10 is driven on the left and right side surfaces of the base 16a of the arm 16 to turn on and off the motor built in the main body 14 that is a drive source of the yarn saw 10, and to remove chips. It has the chip removal knob 19 for turning on and off an electric vacuum cleaner (refer FIG. 11). In addition, an operation lamp 15 that is turned on when the power is supplied to the yarn saw 10 is incorporated in the distal end surface of the arm portion 16b.
[0023]
The thread saw blade NB is held under a predetermined tension by an upper end holding mechanism provided in the arm 16 and a lower end holding mechanism provided in the main body 14 below the table 12 and further incorporated in the main body 14. A drive mechanism (not shown) is driven up and down with a predetermined stroke using a motor as a drive source. The mechanism for driving the yarn saw blade NB up and down is well known and will not be described in detail.
[0024]
Next, the circular cutting holding mechanism 30 mounted on the table 12 will be described. The table 12 is provided with screw holes for attachment at four locations, and the circular cutting table 32 of the circular cutting holding mechanism 30 is fixed to the table 12 with embedded type screws. As shown in the drawing, the circular cutting table 32 is provided with a guide hole 35 on a circular arc, and a holding member 40 for circular cutting is movably fitted therein. A guide 44 on which the holding member 40 is placed is extended on the right side of the circular cutting table 32, and the holding member 40 is moved along the guide hole 35 by operating the end of the guide 44. Can move freely. The holding member 40 has a circular shape so as to move smoothly in the guide hole 35, and a needle 41 is fixed upward at the center thereof. As shown in FIG. 4, the guide 44 is provided with an arc-shaped fixing hole 46 that is substantially the same shape as the guide hole 35, in the reverse direction so as to compensate for the movement of the holding member 40 along the guide hole 35. The guide 44 can be fixed at a desired position by screwing the fixing screw 50 into the screw hole provided on the back surface of the round table 32 through the fixing hole 46.
[0025]
Details of the guide hole 35 are shown in FIG. As shown in the drawing, the size of the guide hole 35 is engraved at a pitch of 1 mm, and by combining the center of the needle 41 of the holding member 40 with this, the radius of cutting can be easily set. . The guide hole 35 is formed in a large circular arc shape having one end at a position 10 mm away from the center of the through hole 12a through which the thread saw blade NB passes and the other end at a radius of 150 mm. More specifically, the center of the guide hole 35 is set such that the position of the thread saw blade NB is the origin (0, 0), the feed direction of the workpiece is the Y-axis direction, and the direction orthogonal thereto is the X-axis direction. It is formed as a part of a circular arc passing through the origin (0, 0) and the point (60, 0) with the point (30, 619) as the center.
[0026]
Therefore, when the radius of cutting is 60 mm or less, the needle 41 of the holding member 40, that is, the rotation center of the workpiece that is rotatably held by the needle 41, feeds the workpiece when the X axis is the reference line. If it is located on the front side in the direction and the radius of cutting exceeds 60 mm, it is located on the other side in the feed direction of the workpiece. The yarn saw blade NB has a predetermined length in the Y-axis direction. In this embodiment, the origin in the Y-axis direction is precisely the position of the valley of the tooth of the yarn saw blade NB.
[0027]
Next, how the arc is specified will be described. The inventor examined the fact that the conventional circular cutting with a yarn saw whose center of rotation moves on the X axis in FIG. 5 should actually be far from the perfect circle even though it should theoretically be a perfect circle. Attention was paid to the fact that the saw blade NB is not a theoretical cutting point having a length in the feed direction of the workpiece, but actually has a length. Therefore, the material to be cut receives the radial force in the circular cutting of the material to be cut from the thread saw blade NB along with the cutting, and is distorted in the radial direction. After various studies and trials, in order to eliminate the generation of such force, the inventor should appropriately adjust the cutting start angle of the saw blade NB with respect to the workpiece (hereinafter, referred to as the incident angle β). I came up with the idea that it might be good. The inventor has found that about 2.5 degrees is desirable for a round cut with a radius of 10 mm (φ20) as a provisional value by adjusting the entrance angle by changing the radius of the round cut. The larger the radius of the cut, the obtuse angle. Specifically, it is desirable to decrease the incident angle by about 0.5 degrees every time the radius of the circular cut increases by 10 mm. Therefore, the inventor has further studied and the center position of the circular cutting (the position of the rotation center that holds the workpiece) that obtains a substantially perfect circle is the straight line of the following equation (1) and I found that it was obtained as an intersection other than the origin of the circle. Note that the incident angle β = α · (r−60) / 10.
[0028]

[0029]
When α = 0.5 degrees, when the trajectory of the intersection other than the origin among the intersections of the straight line of Expression (1) and the circle of Expression (2) is obtained using r as a variable, the center position (30, 573) An approximate arc with a radius of 573.8 mm. The inventor designed and tested the guide hole 35 with α = 0.5, and found that a round cut with a radius of 30 to 40 mm slightly deviated from the true circle. Thus, as a result of further examination, it was found that the best result is obtained when the center of the arc of the guide hole 35 is (30, 619). When calculated backward from this result, the angle α in the above equation (1) was 0.46 degrees. Of course, it is estimated that these are affected to some extent by the width of the saw blade NB and the material of the workpiece. Even when the angle α is set to 0.5, the circle obtained with a conventional round cutting device is cut with a precision that is not comparable, so in practice, α≈0.4 to 0.5. There is no problem.
[0030]
The actual circular cutting by the circular cutting holding mechanism 30 of this embodiment will be described with reference to FIGS. FIG. 6 is a schematic diagram in the case of cutting a circle with a radius of 40 mm (φ80) using a wood plate WW as a material to be cut. In this case, the incident angle β1 satisfying the expressions (1) and (2) is 0.92 degrees, and the center position P1 of the needle 41 of the holding member 40 is theoretically (39.99, −0). .64). Although the expansion of the mathematical formula is omitted, if the coordinates (x, y) of the intersection other than the origin of the above formulas (1) and (2) are A = tan β,
x = r / (1 + A ² )
y = A · r / (1 + A ² )
As required.
[0031]
When the needle 41 is aligned with the scale of the guide hole 35, the accuracy of only one digit after the decimal point can be obtained at most. However, the outline R1 obtained as a result of the circular cutting is not generated even if it is cut with a lathe. It became a true circle like no other. FIG. 7 is a schematic diagram in the case where a circle with a radius of 60 mm (φ120) is used using the same plate material WW. In this case, the incident angle satisfying the expressions (1) and (2) was 0 degree, and the center position P2 of the needle 41 of the holding member 40 was (60, 0). Further, FIG. 8 is a schematic diagram in the case where the plate material WW is similarly used and a radius of 120 mm (φ240) is cut. In this case, the incident angle β2 satisfying the expressions (1) and (2) is −2.76 degrees, and the center position P3 of the needle 41 of the holding member 40 is (119.72, 5.77). became. The outlines R2 and R3 obtained as a result of the circular cutting were both true circles so that no machining waste was produced even if they were cut with a lathe.
[0032]
In the above description, the wood plate material WW is taken as an example of the material to be cut, but an accurate circular cutting can be similarly performed on a metal plate (iron, aluminum, copper plate, etc.) or plastic. In the case of a metal plate, it cannot be rotatably held by the needle 41. In such a case, as shown in FIG. 9, if a magnet 47 is rotatably attached to a guide 44a, the holding means can be used. Good. In the case of a metal plate or plastic, as shown in FIG. 10, it is also possible to use a guide 44b having a suction cup 48 rotatably attached thereto. Further, when the yarn saw 10 is configured as a dedicated machine for circular cutting, the holding member 40 may be fixed. Further, instead of providing the cutting means on the cutting table 32, it is possible to provide the cutting means from the arm 16 side.
[0033]
Although the configuration of the circular cutting holding mechanism 30 in the present embodiment has been clarified above, the remaining configuration as the yarn saw machine 10 will be supplemented. The electrical system of this yarn saw machine 10 is shown in FIG. As illustrated, the yarn saw 10 includes a sawing power circuit 70 for the yarn saw 10 itself and a cleaner power circuit 75 for supplying power to the electric vacuum cleaner. The saw-tooth power supply circuit 70 includes a power plug 71 to be inserted into an outlet (not shown) already installed on a wall or the like, and powers on the motor M by a main switch 72 provided in the circuit. The main switch 72 turns on and off the contact in conjunction with the turning operation of the operation knob 18 (see FIGS. 1 and 2) provided on the arm 16 and opens and closes the power circuit 70 for the saw. In addition, an operation lamp 15 is incorporated in parallel with the motor M in the sawing power circuit 70. Therefore, when the operation knob 18 is turned to the ON side, the circuit is closed by the main switch 72, the motor M is driven, and the operation lamp 15 is lit. As a result, the thread saw blade NB moves up and down and the workpiece can be cut. It should be noted that a fuse 73 is incorporated in the sawing power circuit 70. In addition, a surge limiting capacitor 74 is installed in parallel with the motor M, and damage to the motor M due to a surge voltage caused by a lightning strike or the like is avoided.
[0034]
The power supply circuit 75 for the vacuum cleaner is provided in parallel with the power circuit for the saw saw 70 described above, and includes an outlet 63 into which a power plug of the vacuum cleaner is inserted, and a vacuum cleaner switch 76 provided in the circuit. The electric vacuum cleaner is turned on through the outlet 63. This vacuum cleaner switch 76 turns on and off the contact in conjunction with the turning operation of the chip removal knob 19 (see FIG. 2) provided on the arm 16 to open and close the vacuum cleaner power circuit 75. For this reason, when the chip removal knob 19 is turned to the on side, the circuit is closed by the cleaner switch 76 and the electric vacuum cleaner is driven, and the suction hole 21a provided in the guide block 21 described above and Chips are sucked through the through holes 12a to collect dust.
[0035]
Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various embodiments can be implemented without departing from the gist of the present invention. For example, the present invention can be applied to a cutting device such as a band saw other than the yarn saw. Further, the center of rotation of the workpiece by the holding means may be arranged on the left side of the cutting position.
[Brief description of the drawings]
FIG. 1 is a schematic perspective view of a yarn saw machine 10 according to an embodiment.
FIG. 2 is a front view of the yarn saw machine 10;
FIG. 3 is a side view of the yarn saw machine 10;
4 is a perspective view showing a structure of a holding member 40 and a guide 44 to which the holding member 40 is attached. FIG.
5 is a plan view showing details of a guide hole 35. FIG.
FIG. 6 is a schematic diagram showing a state of cutting a circle with a radius of 40 (φ80).
FIG. 7 is a schematic diagram showing a state of cutting a circle with a radius of 60 (φ120).
FIG. 8 is a schematic diagram showing a state of cutting a circle with a radius of 120 (φ240).
FIG. 9 is a perspective view showing an example in which a magnet 47 is used as a holding member.
FIG. 10 is a perspective view showing an example in which a suction cup 48 is used as a holding member.
11 is a circuit diagram showing the electrical configuration of the yarn saw machine 10. FIG.
FIG. 12 is an explanatory diagram showing a state of circular cutting using a conventional circular cutting device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Yarn saw machine 12 ... Table 12a ... Through-hole 14 ... Main body 15 ... Operation lamp 16 ... Arm 16a ... Base part 16b ... Arm part 16c ... Handle part 17 ... Adjustment knob 18 ... Operation knob 19 ... Chip removal knob 20 ... Guide mechanism 21 ... Guide block 21a ... Suction hole 30 ... Holding mechanism for round cutting 32 ... Circle cutting table 35 ... Guide hole 40 ... Holding member 41 ... Needle 44 ... Guide 44a ... Guide 44b ... Guide 46 ... Fixing hole 47 ... Magnet 48 ... Suction cup 50 ... Fixing screw 63 ... Outlet 70 ... Power circuit 71 for sawing board ... Power plug 72 ... Main switch 73 ... Fuse 74 ... Surge limiting capacitor 75 ... Power supply circuit 76 for vacuum cleaner ... Vacuum cleaner switch M ... Motor NB ... Yarn sawtooth P1 P3 ... Center position TT ... Thread saw tooth WW ... Plate material α ... Angle β1 ... Entrance angle β2 ... Entrance angle

Claims

A cutting device having a table on which a plate-like workpiece is placed, and cutting the workpiece with a saw blade,
Provided with a holding means that is provided on the table and holds a workpiece to be cut circularly at a predetermined rotation center, and
The central position of the holding means is
When the radius of the circular cutting is in the range of 150 mm or less, assuming that the cutting position by the saw blade is the origin, the feed direction of the workpiece is the y axis, and the direction orthogonal to this is the x axis, (x, y) = By placing (30,619) [unit mm] as an approximate center point and placing it in a range on an arc passing through the cutting position of the saw blade,
When the radius of the cut of the workpiece is approximately 60 mm or less, it is positioned on the arc on the front side in the feed direction of the workpiece from the center of the saw blade ,
If the radius of the cut of the workpiece exceeds about 60 mm, a cutting device capable of cutting a circle positioned on the arc on the side of the workpiece in the feed direction from the center of the saw blade .

A cutting device having a table on which a plate-like workpiece is placed, and cutting the workpiece with a saw blade,
Provided with a holding means that is provided on the table and holds a workpiece to be cut circularly at a predetermined rotation center, and
The central position of the holding means is
When the cutting position by the saw blade is the origin, the feed direction of the material to be cut is the y-axis, the direction orthogonal thereto is the x-axis, and the radius of the circular cutting is r [mm], at least a radius of 150 mm or less In the circle cutting of, provided in the locus range of the intersection of the next straight line and the circle other than the origin,
Straight line y = tan {α · (r−60) / 10} · x
α ≒ 0.4 ~ 0.5
Circle (x−r / 2) ² + y ² = (r / 2) ²
When the cutting radius of the workpiece is equal to or less than a predetermined value, the workpiece is positioned on the locus on the front side in the feed direction of the workpiece from the center of the saw blade,
When the radius of the cut of the workpiece exceeds the predetermined value, it is positioned on the locus on the side of the workpiece in the feed direction from the center of the saw blade.
Cutting device that can cut into circles .

The cutting apparatus according to claim 2, wherein the predetermined value is approximately 60 mm when the material to be cut is a plate material such as wood or an iron plate .

The cutting device according to any one of claims 1 to 3, further comprising a moving mechanism capable of continuously moving the rotation center of the holding means .

A holding device for circular cutting, which has a table on which a plate-like workpiece is placed, is provided in a cutting device that cuts the workpiece with a saw blade, and rotatably holds the workpiece. ,
The central position of the holding means is
When the radius of the circular cutting is in the range of 150 mm or less, assuming that the cutting position by the saw blade is the origin, the feed direction of the workpiece is the y axis, and the direction orthogonal to this is the x axis, (x, y) = By placing (30,619) [unit mm] as an approximate center point and placing it in a range on an arc passing through the cutting position of the saw blade,
When the cutting radius of the workpiece is approximately 60 mm or less, the cutting material is positioned on the arc on the front side in the feed direction of the workpiece from the center of the saw blade ,
If the radius of the cut of the workpiece exceeds about 60 mm, it is positioned on the arc on the side of the workpiece in the feed direction from the center of the saw blade .
Holding device for cutting a circle.

A holding device for cutting a circle , which has a table on which a plate-like workpiece is placed, is provided in a cutting device that cuts the workpiece with a saw blade and rotatably holds the workpiece. ,
The center position of the rotation is
When the cutting position by the saw blade is the origin, the feed direction of the material to be cut is the y-axis, the direction orthogonal thereto is the x-axis, and the radius of the circular cutting is r [mm], at least a radius of 150 mm or less In the circle cutting of, provided in the locus range of the intersection of the next straight line and the circle other than the origin,
Straight line y = tan {α · (r−60) / 10} · x
α ≒ 0.4 ~ 0.5
Circle (x−r / 2) ² + y ² = (r / 2) ²
Wherein when the radius of the circle cutting of the cutting material is less than the predetermined value, allowed position on the trajectory in feeding direction front side of the該被cutting material from the center of the fret saw tooth,
When the radius of the cut of the workpiece exceeds the predetermined value, the device for holding a cut is positioned on the locus on the side of the workpiece in the feed direction from the center of the saw blade .

The holding device for cutting a circle according to claim 6 , wherein the predetermined value is approximately 60 mm when the material to be cut is a plate material such as wood or an iron plate.

The holding device for circular cutting according to any one of claims 5 to 7, further comprising a moving mechanism capable of continuously moving the rotation center .

The cutting device according to any one of claims 1 to 4,
The holding means pierces the workpiece, a needle that rotatably holds the workpiece at the rotation center, adsorbs the workpiece by negative pressure, and holds the workpiece at the rotation center. A cutting apparatus having at least one of a negative pressure adsorption mechanism that performs magnetic adsorption on the workpiece and rotatably holds the workpiece on the rotation center.

A needle that pierces the workpiece and holds the workpiece rotatably at the rotation center, and a negative pressure adsorption mechanism that adsorbs the workpiece by negative pressure and holds the workpiece rotatably at the rotation center Or at least one of magnetic attraction mechanisms for magnetically attracting the material to be cut and holding the material to be rotated at the rotation center. Holding device.