JP3867466B2

JP3867466B2 - Extrusion product cutting mechanism and extrusion molding apparatus

Info

Publication number: JP3867466B2
Application number: JP2000063515A
Authority: JP
Inventors: 光豊田中; 博志小島; 昇桜井; 直人高野
Original assignee: Seiko Epson Corp
Current assignee: Seiko Epson Corp
Priority date: 2000-03-08
Filing date: 2000-03-08
Publication date: 2007-01-10
Anticipated expiration: 2020-03-08
Also published as: JP2001252961A

Description

【０００１】
【発明の属する技術分野】
本発明は押出成形品の切断機構及び押出成形装置に係り、特に、連続的に成形品を押し出しながら成形する押出成形装置において、押出成形品を切断するための構造に関する。
【０００２】
【従来の技術】
一般に、押出成形装置においては、成形材料を所定形状のダイスを通して押し出すことによって連続的に成形する。この押出成形装置を用いて製造する成形品としては、例えば、磁性粉をナイロン（商標）等の樹脂バインダと混練したものを押出成形し、樹脂バインダを硬化させることによって形成した磁石がある。押出成形装置には、通常、ダイスを通して押し出される押出成形品を所定の長さに切断するための切断機構が設けられる。
【０００３】
従来の押出成形装置の切断機構としては、押出成形機本体の出口において、押出成形品の押出方向に配列された複数の円盤状のダイヤモンドブレードを搭載し、全体が押出成形品の押出方向に往復動作可能に構成されたものがある。この切断機構は、押出成形品がある程度押し出されると、全体が押出方向に押出成形品の押出速度と同じ速度で移動しながらダイヤモンドブレードによって複数箇所で同時に切断を行い、切断が完了すると、最初の位置に復帰するという動作を繰り返すように構成されている。
【０００４】
また、一般に用いられている切断方法としては、振動、熱（レーザー光による切断等）、水流等を用いた種々の方法があり、切断ではなく、押出成形品を折り割りによって分離する方法もある。さらに、押出成形品の切断時において、押出成形機の押出を一時的に停止させ、その停止期間中に押出成形品を切断する機構も用いられている。
【０００５】
【発明が解決しようとする課題】
しかしながら、上記従来の押出成形装置の切断機構においては、複数枚のダイヤモンドブレードを同時に用いることによって作業効率を高めているものの、ダイヤモンドブレードの磨耗状態や寸法ばらつきによって各ブレード間に厚さのばらつきが生じるとともに、各ダイヤモンドブレードの取り付け精度等によってブレード間隔にもばらつきが生ずるので、切断によって分離された各成形品の長さに寸法のばらつきが発生しやすい。したがって、各成形品の寸法誤差を低減するためにダイヤモンドブレードの取り付け位置をスペーサ等により調整する必要があり、さらに、機構が複雑で、しかも全体を押出成形品の進行方向に往復移動させる必要があるので、動作精度に限界があるなど、成形品の形状精度を高めにくいとともに機構の管理が困難且つ煩雑であって、しかも、或る程度長い切断時間が必要となるので、生産性が低いという問題点がある。
【０００６】
また、振動、熱、水流を用いた切断方法ではいずれも装置構造が大掛かりになりコストが高くつくとともに、切断精度の面でも問題がある。また、折り割り（破断）による分離方法では、分離可能な成形品の長さに制約が生じたり、破断面形状にばらつきが存在したりするという問題点がある。
【０００７】
さらに、切断時に一時的に押出成形機の押出動作を停止する場合には、押出成形品の停止期間に対応する部位に節が形成されてしまうという問題点がある。
【０００８】
そこで本発明は上記問題点を解決するものであり、その課題は、連続的に押し出される押出成形品を切断する切断機構において、成形品の連続的な押出動作中においても切断が可能であって、簡単な構造で成形品の寸法精度を確保することができ、しかも押出成形品を迅速に切断することの可能な機構を提供することにある。
【０００９】
【課題を解決するための手段】
上記課題を解決するために本発明の押出成形品の切断機構は、押出成形によって押出される押出成形品を切断するための押出成形品の切断機構において、前記押出成形品の押出方向に伸びる成形品案内路と、前記成形品案内路に沿って進行する前記押出成形品に対して出没可能に配置された切断刃を備えた成形品切断手段とを有し、前記成形品切断手段には、前記押出成形品を前記成形品案内路に向けて押える第１の押圧部材と、前記押出成形品を前記成形品案内路に向けて押える第２の押圧部材が設けられていることを特徴とする。
【００１０】
この発明によれば、第１の押圧部材と第２の押圧部材とによって押出成形品が２箇所にて成形品案内路に押圧されているので、押圧成形品が連続的に押出されているときに、切断刃によって押圧成形品を切断する際に押出成形品の移動が切断部位において抑止されても、２箇所の押圧部位の間において押出成形品が撓むことによって押圧成形品の連続押出量を吸収することができる。その結果、押出成形品における押出成形部位（ダイスから成形材料が押出されている部位）に大きな押出抵抗を与えずに済み、押出成形品の形状不良の発生を抑制することができる。したがって、切断機構を固定した場合であっても押出成形を中断することなく、切断位置のずれや押出成形品の損傷などを低減することができる。また、切断刃の上流側に第１の押圧部材を設けているので、切断刃が押出成形品を切断した後に押出成形品の切断部位から離れるとき、切断刃の離反動作とともに押出成形品の上流側部分（この部分は連続的に押出成形がなされている場合には切断刃に対して押し付けられた状態となっている。）が切断刃の離反方向に大きく捲くれ上がることを防止することができる。
【００１１】
なお、上記第１の押圧部材と第２の押圧部材とは押出方向に離隔して配置されていることが好ましい。また、第１の押圧部材を前記切断刃に隣接した上流側位置に配置し、第２の押圧部材を第１の押圧部材からさらに上流側に離れた位置に配置することが好ましい。
【００１２】
本発明において、前記押出成形品の押出速度を検出する押出速度検出手段を有し、前記第２の押圧部材は、前記成形品案内路に沿って進行する前記押出成形品に接触して前記押出成形品の移動に従って回転する検出ローラであり、前記押出速度検出手段は、前記検出ローラの回転に基づいて前記押出成形品の押出速度を検出するように構成されていることが好ましい。この手段によれば、第２の押圧部材は、押出成形品に接触してその移動に従って回転するので押出成形品に大きな負荷を与えずに押圧することができ、また、押出速度検出手段の検出ローラとしても機能するので、部品数を低減し、装置構造をさらに簡易に構成することができる。
【００１３】
本発明において、前記第１の押圧部材は、前記成形品案内路に沿って進行する前記押出成形品に接触して前記押出成形品の移動に従って回転する押圧ローラであることが好ましい。この手段によれば、第１の押圧部材は押出成形品に大きな負荷を与えずに押圧することができる。
【００１４】
本発明において、前記成形品切断手段には、前記切断刃を駆動する駆動手段が設けられ、前記駆動手段には、前記切断刃を前記押出成形品に向けて押し出すように構成されているとともに、前記切断刃を押し出す期間以外には前記切断刃に対して実質的に干渉しないように構成された押出部材と、前記切断刃を前記押出成形品側から退避させる方向に付勢する退避手段とが設けられていることが好ましい。この場合には、押出部材によって切断刃を押出成形品に向けて押し出し、その後は退避手段の付勢力によって切断刃を復帰させるようにしているので、切断刃の動作速度を高速化することができるとともに、切断刃の繰り出し動作の終了時点と、復帰動作の開始時点との時間間隔を短縮できるので、切断機構を固定した場合であっても押出成形を中断することなく、切断位置のずれ、切断面の傾斜、押出成形品の損傷などを低減することができる。
【００１５】
本発明において、前記押出部材は前記切断刃が駆動する方向と交差する方向に往復動作するように構成され、前記押出部材の往路動作と復路動作のいずれか一方の動作途中において前記押出部材により前記切断刃が前記押出成形品に向けて押し出されるように構成されていることが好ましい。この場合、押出部材における動作途中において切断刃を押出成形品に向けて押し出すように構成されているので、押出部材の加減速特性に影響されることなく、切断刃を高速に動作させることができる。
【００１６】
本発明において、前記切断刃と前記押出部材の少なくとも一方には、前記往路動作と前記復路動作のいずれか一方の動作途中において相手方に当接して前記切断刃を前記押出成形品に向けて押し出すための、前記押出部材の往復動作方向と前記切断刃が駆動する方向との間の中間方向に向いた傾斜面を備え、前記押出部材は、前記往路動作と前記復路動作のいずれか他方において前記切断刃に対する回避動作を行うように構成されていることが好ましい。
【００１７】
本発明において、前記押出部材は、前記往路動作と前記復路動作のいずれか他方の動作途中において前記切断刃に当接したときに前記切断刃を回避する向きに回動するように構成され、この回動の向きとは逆向きに、前記押出部材を付勢する姿勢復帰手段を備えていることが好ましい。
【００１８】
本発明において、前記押出部材と前記切断刃は、前記往路動作と前記復路動作のいずれか他方の動作途中において、前記切断刃が駆動する方向に対してほぼ直交する方向に相互に当接する当接面を備えていることが好ましい。
【００１９】
また、本発明の押出成形装置は、上記いずれかの押出成形品の切断機構を備えたものである。
【００２０】
【発明の実施の形態】
次に、添付図面を参照して本発明に係る押出成形品の切断機構及び押出成形装置の実施形態について詳細に説明する。図１は本実施形態の切断機構の全体構成を示す概略側面図である。本実施形態の押出成形装置においては、押出成形機１０の出口に配置された切断機構２０を備えている。この切断機構２０には、押出成形品３の押し出し方向に沿って伸びるように形成された成形品案内路２１と、成形品案内路２１の途中の上流側に配置された成形速度検出部２２と、成形速度検出部２２の下流側に配置された成形品切断部２３とを備えている。
【００２１】
成形品案内路２１は、押出成形機１０の内部に設けられた内部案内路１１に対して案内経路が連続するように接続されており、押出成形品３を案内する案内面を備え、上記の成形速度検出部２２及び成形品切断部２３を通過した先において終端を有する。成形品案内路２１の終端部の下方には分割された成形品を受け取り、図示しない収容部に成形品を排出するための排出シュート２４が配置されている。
【００２２】
成形速度検出部２２は、上記成形品案内路２１上を進む長尺の押出成形品３に上方から当接する、回転自在に取り付けられた検出ローラ２２ａと、この検出ローラ２２ａを所定の圧力で押出成形品３に対して押し付けるためのコイルバネなどの弾性体２２ｂとを有する。そして、押出成形品３に押し付けられた検出ローラ２２ａが押出成形品３の進行とともに回転するとき、検出ローラ２２ａの回転量をエンコーダ等の検出器により検出することによって、押出成形品３の進行速度（押出速度）を測定するように構成されている。
【００２３】
また、成形品切断部２３は、成形品案内路２１上を進む押出成形品３を上方から押さえ付ける押圧ローラ２３１と、この押圧ローラ２３１の下流側に隣接した位置において押出成形品３を上方から切断する切断刃（カッタ）２３２とを備えている。切断刃２３２の下流側斜め上方には吸引ノズル２５が配置され、この吸引ノズル２５は図示しない排気装置に接続されており、切断刃２３２によって押出成形品３を切断する際に発生する切り屑を吸引するようになっている。切断刃２３２によって所定長さに切断された成形品３ａは、押出成形品３の進行によってやがて成形品案内路２１上から上記の排出シュート上へ落下し、排出される。
【００２４】
図２は、上記成形品切断部２３の側面図であり、図３は成形品切断部２３の正面図（成形品案内路２１の下流側から見える面を正面とする。）である。成形品切断部２３には、成形品案内路２１の上方に固定された板状の固定部材２３３が成形品案内路２１を跨ぐように設けられている。この固定部材２３３には、板状の支持部材２３４が固定部材２３３の板面に沿って昇降可能に取り付けられている。支持部材２３４にはネジ軸２３５の下端が固定され、このネジ軸２３５は固定部材２３３に対して間接的に螺合し、このネジ軸２３５を回転させることによって、支持部材２３４を固定部材２３３に対して上下に移動させることができるようになっている。
【００２５】
支持部材２３４には、プランジャー型の電磁ソレノイドなどからなる駆動源２３８１が固定され、この駆動源２３８１の駆動軸２３８２は、接続部材２３８３を介して従動部材２３８４に固定されている。従動部材２３８４は、支持部材２３４に対してリニアガイド２３４ａによって水平方向に案内されている。従動部材２３８４には、押出部材２３８５が回動可能に取り付けられている。押出部材２３８５は、従動部材２３８４に設けられたストッパ２３８４ａによって、図３における反時計周りには図示の状態から回動することのないように回動範囲が制限されている。ただし、押出部材２３８５は図示の状態から図示時計周りには回動可能に構成されている。また、押出部材２３８５の図示上端寄りの部位には、従動部材２３８４に一端が固定されたコイルバネ等の弾性部材２３８６の他端が接続されている。この弾性部材２３８６によって、押出部材２３８５は常に図示反時計周りの回転方向に付勢されている。
【００２６】
上記押出部材２３８５の下端部には、図３における図示左側斜め下方に向いた傾斜面２３８５ａが形成されているとともに、図示右側に向いた垂直面２３８５ｂが形成されている。
【００２７】
従動部材２３８４の下方には、支持部材２３４に対して昇降可能に取り付けられた切断支持体２３８８が配置され、この切断支持体２３８８の上部には上記押出部材２３８５の下方に突出する被動部材２３８７が固定されている。また、切断支持体２３８８には上記の切断刃２３２が固定されている。切断支持体２３８８には、支持部材２３４に一端が取り付けられたコイルバネ等からなる弾性部材２３８９の他端が接続され、弾性部材２３８９によって切断支持体２３８８は常に上方に付勢されている。
【００２８】
被動部材２３８７の上端部には、図３における図示右側斜め上方に向いた傾斜面２３８７ａが形成されているとともに、図示左側に向いた垂直面２３８７ｂが形成されている。
【００２９】
切断刃２３２の刃先２３２ａは、押出成形品３の断面形状、すなわち、円弧状断面に対応した凸の円弧状に形成されている。また、切断刃２３２の刃先２３２ａは、成形品案内路２１の下流側に傾斜刃面２３２ｂが形成されていることによって先端に向けて徐々に薄肉化されている。
【００３０】
一方、成形品案内路２１は、図３に示すように、フレーム２１０上に防振ゴム等の振動吸収体２１５を介して固定された基体２１１の上面に断面Ｖ字状のＶ溝が形成され、このＶ溝内に嵌合するように支持案内部材２１２が収容されている。この支持案内部材２１２は基体２１１に取り付けられた保持枠２１３によって基体上に保持されている。支持案内部材２１２には、上記切断刃２３２の刃先２３２ａが損傷しない程度の軟質材からなる案内部材２１４が固定されている。本実施形態では押出成形品３が円弧状断面を有する樋形状に形成されているので、案内部材２１４の表面には、押出成形品３の形状である樋形状に対応した円弧状断面を備えた案内溝２１４ａが形成されている。そして、上記押出成形品３は、この案内溝２１４ａ内に押し出されてくるようになっている。
【００３１】
また、上記基体２１１の両側部には取付支持部材２１６が取付固定され、この取付支持部材２１６の上端部に対してアーム部材２３６が回動自在に取り付けられている。さらに、このアーム部材２３６の先端には上記押圧ローラ２３１が回転自在に軸支されている。アーム部材２３６の上流側の端部には、コイルバネ等の弾性部材を含む弾性支持部２３７が接続されている。ここで、アーム部材２３６に軸材が固定され、この軸材は弾性部材によって常に上方へ付勢されているので、アーム部材２３６は常に押圧ローラ２３１を所定の圧力で下方へ押し付けるように作用する。
【００３２】
本実施形態においては、上記の成形速度検出部２２において検出ローラ２２ａの回転によって押出成形品３の押出速度が検出され、この押出速度に応じて、図示しない制御装置（例えばプログラマブルコントローラやマイクロプロセッサユニットなど）が成形品切断部２３を動作させ、押出成形品３を切断する。すなわち、押出速度が増大すれば成形品切断部２３による切断動作の間隔を短くし、押出速度が小さくなれば切断動作の間隔を長くする。例えば、押出成形品３を一定長さに切断する場合には、押出速度が一定であれば、一定の時間間隔で切断動作を実施し、押出速度が増大若しくは減少すれば切断動作の時間間隔を短縮若しくは延長する。
【００３３】
また、上記の成形品切断部２３による切断動作を制御する方法としては、図１に示すように成形品案内路２１の終端部近傍に光センサ等からなる検出装置２６を配置し、この検出装置２６によって押出成形品３の先端部が検出されたときに上記制御装置によって成形品切断部２３を動作させ、切断するようにしてもよい。この場合、上記成形速度検出部２２は押出成形品３の押出速度の監視のために用いられる。
【００３４】
成形品切断部２３においては、上記の制御装置からの制御信号に基づき、まず図３に示す駆動源２３８１が稼動して駆動軸２３８２が引き込まれ、これに従って接続部材２３８３を介して従動部材２３８４が図示左側に移動する。従動部材２３８４の移動に伴って押出部材２３８５も図示左側へ移動し、押出部材２３８５の傾斜面２３８５ａが被動部材２３８７の傾斜面２３８７ａに衝突する。このとき、押出部材２３８５はストッパ２３８６によって図示反時計周りの回動が妨げられているので、傾斜面２３８５ａはそのまま傾斜面２３８７ａを押しのけるため、被動部材２３８７は切断支持体２３８８とともに下降する。そして、切断支持体２３８８に取り付けられた切断刃２３２もまた下降するので、切断刃２３２は下方の押出成形品３を切断する。
【００３５】
押出部材２３８５が被動部材２３８７を下方へ押しやって、被動部材２３８７の上方を通過し、図示左側へ移動する（図示一点鎖線で示す。）と、切断支持体２３８８及び切断刃２３２は押出部材２３８５からの応力から解放され、弾性部材２３８９の弾性力によって上方へ復帰し始める。
【００３６】
次に、駆動源２３８１は、上記動作とは逆に駆動軸２３８２を突出させ、これに伴って従動部材２３８４とともに押出部材２３８５も図示右側に戻り始める。このとき、被動部材２３８７は既に上昇しているか、或いは、上昇途上にあるので、戻り始めた押出部材２３８５の先端の垂直面２３８５ｂは被動部材２３８７の先端の垂直面２３８７ｂに衝突する。このとき、押出部材２３８５から被動部材２３８７に及ぼされる衝撃は水平方向に加わるので、被動部材２３８７並びにこれと一体化されている切断支持体２３８８及び切断刃２３２の上昇動作、或いは、上下位置には影響をほとんど与えないようになっている。また、押出部材２３８５は従動部材２３８４に対して図示時計方向には回動可能に取り付けられているので、垂直面２３８５ｂが垂直面２３８７ｂに衝突すると、その反動で押出部材２３８５は図示二点鎖線に示すように時計周りに回動し、被動部材２３８７を回避するようにして被動部材２３８７の上方を通過する。そして、最終的に押出部材２３８５は図示右側の初期位置に戻るとともに、弾性部材２３８６の弾性力によって上記の回動方向とは逆方向に回動して初期姿勢に復帰し、図示実線で示すようになる。
【００３７】
ここで、上記駆動源２３８１には、例えば、通電期間において駆動軸２３８２が引き込まれ、通電が解除されると駆動軸２３８２が弾性力等によって復帰するように構成された電磁ソレノイドを用いることができる。この場合、その通電時間は約１秒程度である。このように通電時間（或いは通電サイクル）が長くても、或いは、駆動軸２３８２の動作の応答速度（動作開始時点）が遅くても、上記のような機構によって、切断刃２３２の降下速度及び上昇速度は駆動軸２３８２の引き込み速度及び弾性部材２３８９の弾性力で決定されるので、切断刃の動作を駆動源２３８１の動作特性にあまり影響されることなく高速化することができる。
【００３８】
本実施形態では、例えば図１の右側から図示左側へ所定速度で押出成形品３が進んでいるとき、切断刃２３２が上方から降下し、刃先２３２ａが押出成形品３の表面に接触してから、さらに降下して押出成形品３の厚さ分だけ下降すると、押出成形品３は完全に切断される。そして、その後、切断刃２３２は再び上昇し、押出成形品３から離反する。
【００３９】
このとき、切断刃２３２が押出成形品３を切断している間にも、押出成形品３は図示左側へ向けて移動しているので、切断期間（切断刃３が実際に押出成形品３を切り進んでいる期間）においても徐々に図示左側へ移動する。したがって、厳密には、切断刃２３２は上流側の押出成形品３によって図示左側へ僅かではあっても押し曲げられ、同時に、上流側の押出成形品３は切断刃２３２によって図示右側へ押し戻される。このとき、切断刃２３２は下流側、すなわち図２に示す左側の刃面にのみ、刃先２３２ａを形成するための傾斜刃面２３２ｂが形成されており、上流側、すなわち図示右側の刃面はほぼ垂直に形成されているので、傾斜面が上流側の刃面にも形成されている場合や、上流側の刃面にのみ形成されている場合に比べて、切断刃２３２が下流側へ押し曲げられる量、及び、上流側の押出成形品３が上流側へ押し戻される量を共に低減することができるから、押出成形品３の切断位置をより正確にすることができ、また、切断面をより垂直に形成することができ、しかも、押出成形品３に与える損傷をより低減することができる。
【００４０】
上述のように、切断刃２３２による押出成形品３の切断動作中においては、押出成形品３の押出方向への移動が切断刃２３２によって妨げられ、切断部位よりも上流側にある押出成形品３には圧縮応力が加わる。この圧縮応力は、押出成形品３の撓みによって或る程度は吸収される。一方、本実施形態では、押出成形品３は押出成形機１０の出口に配置された検出ローラ２２ａと、切断刃２３２に隣接された押圧ローラ２３１とによって成形品案内路２１に押し付けられているので、上記圧縮応力は、検出ローラ２２ａによる押圧部位と、押圧ローラ２３１による押圧部位との間において成形品案内路２１から離反するようにして撓み、図４に一点鎖線で示すように両押圧部位間において弓形に湾曲する。
【００４１】
このとき、押出成形機１０は検出ローラ２２ａのさらに上流側に配置されているので、上記の検出ローラ２２ａと押圧ローラ２３１との間に発生する押出成形品３の撓みは押出成形機１０の図示しない出口まではほとんど影響せず、押出成形の成形状態への影響もほとんど現れない。
【００４２】
次に、切断刃２３２が下降して押出成形品３を完全に切断した後、切断刃２３２は上昇を始める。この切断刃２３２の上昇期間においても、切断刃２３２が上流側の押出成形品３から完全に離反するまでの間は、上流側の押出成形品３の移動を妨げ続ける。したがって、この間においても上記のように図４に一点鎖線で示す押出成形品３の湾曲度合は増大する。
【００４３】
また、切断刃２３２の上昇期間においては、図５に点線で示すように、切断刃２３２の上昇とともに押出成形品３の上流側の切断端部が上方へ捲くれ上がろうとする。このとき、切断刃２３２の上流側に隣接する押圧ローラ２３１は押出成形品３の切断端部の捲くれ上がりを妨げるので、押出成形品３が大きな損傷を受けることを防止することができる。
【００４４】
上記の効果をさらに高めるためには、図２に示す切断刃２３２自体を押出成形品３に向けて下流側へやや傾斜させて設置し、その傾斜方向に降下させることが好ましい。このようにすると、図示左側へ進む押出成形品３に対して上流側から切り込み、斜め下流側へ切り進むことになるので、上記の切断期間において、押出成形品３の移動量を切断刃２３２の斜めに切り進む量によって減殺することができ、その結果、押出成形品３の切断面を垂直面にさらに近い面に形成することができる。また、上記と同様に、押出成形品３に与える損傷をさらに低減することができる。
【００４５】
ここで、切断刃２３２の垂線に対する傾斜角度は、本実施形態の切断機構の構成においては、１〜５度の範囲内であることが好ましく、特に、２〜３度であることが望ましい。これらの範囲を下回ると上記の効果を得ることができず、これらの範囲を上回ると切断不良を生ずる恐れがある。
【００４６】
本実施形態では、駆動源２３８１の動作によって押出部材２３８５を水平方向に移動させ、その往路動作の途中において押出部材２３８５を被動部材２３８７に衝突させて切断刃２３２を下降させ、その後、切断刃２３２が弾性部材２３８９の弾性力によって上昇するとともに、押出部材２３８５の復路動作は切断刃２３２の上昇を妨げないようになっているので、押出部材２３８５の往復動作における加減速特性の影響を受けることなく、切断刃２３２をきわめて迅速に昇降させることができるとともに、切断刃２３２の下降動作の終了時点と、上昇動作の開始時点との間のタイムラグを低減することができる。
【００４７】
図６（ａ）には本実施形態の切断刃２３２の昇降動作を示すグラフを示し、図６（ｂ）には電磁ソレノイド（駆動源２３８１と同じもの）の垂直姿勢に設置された上下駆動軸に切断刃を固定して構成した切断機構を設けた場合の切断刃の昇降動作を示すグラフを示す。これらのグラフからわかるように、本実施形態では、特に、切断刃の下降動作の終了時点と、上昇動作の開始時点との間の時間がきわめて小さくなっているので、切断動作期間（切断刃が押出成形品に接触している期間）Ｓ１は従来の切断動作期間Ｓ２より大幅に短縮されている。また、切断刃の昇降動作期間（切断刃が下降を開始した時点から上昇が完了した時点までの期間）Ｔ１もまた、従来の昇降動作期間Ｔ２よりも短縮されている。本実施形態では、切断刃の昇降速度自体も、駆動源に直接接続された切断刃の動作速度よりも高速化されるため、通常の切断機構の場合よりも大幅に切断動作期間Ｓ１を短縮することが可能となっている。
【００４８】
尚、本発明の押出成形品の切断機構及び押出成形装置は、上述の図示例にのみ限定されるものではなく、本発明の要旨を逸脱しない範囲内において種々変更を加え得ることは勿論である。
【００４９】
【発明の効果】
以上、説明したように本発明によれば、第１の押圧部材と第２の押圧部材とによって押出成形品が２箇所にて成形品案内路に押圧されているので、押圧成形品が連続的に押出されているときに、切断刃によって押圧成形品を切断する際に押出成形品の移動が切断部位において抑止されても、２箇所の押圧部位の間において押出成形品が撓むことによって押圧成形品の連続押出量を吸収することができる。その結果、押出成形品における押出成形部位（ダイスから成形材料が押出されている部位）に大きな押出抵抗を与えずに済み、押出成形品の形状不良の発生を抑制することができる。したがって、切断機構を固定した場合であっても押出成形を中断することなく、切断位置のずれや押出成形品の損傷などを低減することができる。また、切断刃の上流側に第１の押圧部材を設けているので、切断刃が押出成形品を切断した後に押出成形品の切断部位から離れるとき、切断刃の離反動作とともに押出成形品の上流側部分（この部分は連続的に押出成形がなされている場合には切断刃に対して押し付けられた状態となっている。）が切断刃の離反方向に大きく捲くれ上がることを防止することができる。
【図面の簡単な説明】
【図１】本発明に係る押出成形品の切断機構及び押出成形装置の実施形態の全体構成を示す概略構成図である。
【図２】同実施形態における成形品切断部の側面図である。
【図３】同実施形態における成形品切断部の正面図である。
【図４】同実施形態における切断中の押出成形品３の湾曲形状を一点鎖線で示す概略構成図である。
【図５】同実施形態における切断中の押出成形品３の湾曲形状（一点鎖線）及び切断刃の上昇による押出成形品３の捲くれ上がり状態（点線）を示すグラフ拡大側面図である。
【図６】同実施形態における切断刃の昇降動作を示すグラフ（ａ）及び電磁ソレノイドによってダイレクトに駆動する場合の切断刃の昇降動作を示すグラフ（ｂ）である。
【符号の説明】
１０押出成形機
２０切断機構
２１成形品案内路
２２成形速度検出部
２３成形品切断部
２３１押圧ローラ
２３２切断刃
２３２ａ刃先
２３２ｂ傾斜刃面
２３８１駆動源
２３８５押出部材
２３８５ａ傾斜面
２３８５ｂ垂直面
２３８６，２３８９弾性部材
２３８７被動部材
２３８７ａ傾斜面
２３８７ｂ垂直面
２３８８切断支持体[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an extrusion-molded product cutting mechanism and an extrusion-molding apparatus, and more particularly to a structure for cutting an extrusion-molded product in an extrusion-molding apparatus that performs molding while continuously extruding a molded product.
[0002]
[Prior art]
In general, in an extrusion molding apparatus, a molding material is continuously molded by extruding it through a die having a predetermined shape. As a molded article manufactured using this extrusion molding apparatus, for example, there is a magnet formed by extruding a magnetic powder kneaded with a resin binder such as nylon (trademark) and curing the resin binder. The extrusion apparatus is usually provided with a cutting mechanism for cutting an extruded product extruded through a die into a predetermined length.
[0003]
As a cutting mechanism of a conventional extrusion molding apparatus, a plurality of disk-shaped diamond blades arranged in the extrusion direction of the extruded product are mounted at the exit of the extruder main body, and the whole reciprocates in the extrusion direction of the extrusion molded product. Some are configured to be operable. When the extruded product is extruded to some extent, the cutting mechanism performs cutting at a plurality of locations simultaneously with a diamond blade while moving at the same speed as the extrusion speed of the extruded product in the extrusion direction. The operation of returning to the position is repeated.
[0004]
Moreover, as a cutting method generally used, there are various methods using vibration, heat (cutting by laser light, etc.), water flow, etc., and there is also a method of separating an extrusion-molded product by folding instead of cutting. . Furthermore, a mechanism is also used in which the extrusion of the extruder is temporarily stopped when the extruded product is cut, and the extruded product is cut during the stop period.
[0005]
[Problems to be solved by the invention]
However, in the cutting mechanism of the conventional extrusion molding apparatus, the work efficiency is improved by using a plurality of diamond blades at the same time, but there is a variation in thickness between the blades due to the wear state and dimensional variation of the diamond blades. In addition, since the blade spacing varies depending on the mounting accuracy of each diamond blade, the dimensional variation tends to occur in the length of each molded product separated by cutting. Therefore, in order to reduce the dimensional error of each molded product, it is necessary to adjust the mounting position of the diamond blade with a spacer or the like, and the mechanism is complicated, and it is also necessary to reciprocate the whole in the traveling direction of the extruded product. Therefore, it is difficult to improve the shape accuracy of the molded product, for example, there is a limit to the operation accuracy, and the management of the mechanism is difficult and cumbersome. Moreover, a long cutting time is required, so the productivity is low. There is a problem.
[0006]
In addition, all of the cutting methods using vibration, heat, and water flow have a large apparatus structure and are expensive, and there is a problem in terms of cutting accuracy. In addition, the separation method by folding (breaking) has a problem that the length of the separable molded product is restricted or there is a variation in the shape of the fractured surface.
[0007]
Furthermore, when the extrusion operation of the extruder is temporarily stopped at the time of cutting, there is a problem that a node is formed at a portion corresponding to the stop period of the extruded product.
[0008]
Therefore, the present invention solves the above-mentioned problems, and the problem is that the cutting mechanism that cuts the extruded product that is continuously extruded can be cut even during the continuous extrusion operation of the molded product. An object of the present invention is to provide a mechanism capable of ensuring the dimensional accuracy of a molded product with a simple structure and capable of quickly cutting an extruded product.
[0009]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the cutting mechanism of the extrusion molded product of the present invention is a molding mechanism that extends in the extrusion direction of the extruded product in the cutting mechanism of the extruded product for cutting the extruded product extruded by extrusion molding. An article guide path, and a molded article cutting means provided with a cutting blade disposed so as to be capable of appearing and retracting with respect to the extruded molded article that travels along the molded article guide path. A first pressing member that presses the extruded product toward the molded product guide path and a second pressing member that presses the extruded product toward the molded product guide path are provided. .
[0010]
According to this invention, since the extruded product is pressed against the molded product guide path at two locations by the first pressing member and the second pressing member, when the pressed product is continuously extruded. In addition, even if the movement of the extrusion molded product is suppressed at the cutting site when the press molded product is cut by the cutting blade, the continuous extrusion amount of the press molded product is bent by bending the extrusion molded product between the two pressing sites. Can be absorbed. As a result, it is not necessary to give a large extrusion resistance to the extrusion molding part (the part where the molding material is extruded from the die) in the extrusion molding product, and the occurrence of the shape defect of the extrusion molding product can be suppressed. Therefore, even when the cutting mechanism is fixed, it is possible to reduce misalignment of the cutting position and damage to the extruded product without interrupting the extrusion. In addition, since the first pressing member is provided on the upstream side of the cutting blade, when the cutting blade leaves the cut portion of the extruded product after cutting the extruded product, the upstream side of the extruded product is moved together with the separating operation of the cutting blade. It is possible to prevent the side portion (this portion is in a state of being pressed against the cutting blade when being continuously extrusion-molded) from being greatly swung up in the separating direction of the cutting blade. it can.
[0011]
In addition, it is preferable that the said 1st press member and the 2nd press member are spaced apart and arrange | positioned in the extrusion direction. Moreover, it is preferable to arrange | position the 1st press member in the upstream position adjacent to the said cutting blade, and to arrange | position the 2nd press member in the position further distant from the 1st press member to the upstream.
[0012]
In the present invention, there is provided an extrusion speed detecting means for detecting an extrusion speed of the extruded product, and the second pressing member is in contact with the extruded product that travels along the molded product guide path. It is a detection roller that rotates in accordance with the movement of the molded product, and the extrusion speed detection means is preferably configured to detect the extrusion speed of the extruded product based on the rotation of the detection roller. According to this means, the second pressing member contacts the extruded product and rotates according to the movement thereof, so that it can be pressed without applying a large load to the extruded product, and the detection of the extrusion speed detecting means. Since it also functions as a roller, the number of parts can be reduced, and the device structure can be further simplified.
[0013]
In this invention, it is preferable that a said 1st press member is a press roller which contacts the said extrusion molded product which advances along the said molded product guide path, and rotates according to a movement of the said extrusion molded product. According to this means, the first pressing member can be pressed without applying a large load to the extruded product.
[0014]
In the present invention, the molded product cutting means is provided with drive means for driving the cutting blade, and the drive means is configured to push the cutting blade toward the extruded molded product, Extrusion members configured so as not to substantially interfere with the cutting blades except for a period during which the cutting blades are pushed out, and retracting means for urging the cutting blades in a direction to retract the cutting blades from the extruded product side It is preferable to be provided. In this case, the cutting blade is pushed out toward the extruded product by the pushing member, and thereafter the cutting blade is returned by the urging force of the retracting means, so that the operating speed of the cutting blade can be increased. At the same time, the time interval between the end of the feeding operation of the cutting blade and the start of the return operation can be shortened, so that even if the cutting mechanism is fixed, the cutting position shifts and cuts without interrupting extrusion molding. It is possible to reduce the inclination of the surface and the damage of the extruded product.
[0015]
In the present invention, the push-out member is configured to reciprocate in a direction intersecting a direction in which the cutting blade is driven, and the push-out member moves the push-out member in the middle of either the forward path operation or the return path operation. It is preferable that the cutting blade is configured to be extruded toward the extruded product. In this case, since the cutting blade is configured to be extruded toward the extruded product during the operation of the extrusion member, the cutting blade can be operated at high speed without being affected by the acceleration / deceleration characteristics of the extrusion member. .
[0016]
In the present invention, at least one of the cutting blade and the pushing member is brought into contact with the other party in the middle of either the forward path operation or the backward path operation to push the cutting blade toward the extruded product. And an inclined surface oriented in an intermediate direction between the reciprocating direction of the push-out member and the direction in which the cutting blade is driven, and the push-out member performs the cutting in one of the forward path operation and the return path operation. It is preferable that the avoidance operation is performed on the blade.
[0017]
In the present invention, the pusher member is configured to rotate in a direction to avoid the cutting blade when contacting the cutting blade during the other operation of the forward path operation and the backward path operation. It is preferable that posture returning means for urging the pushing member in a direction opposite to the direction of rotation is provided.
[0018]
In the present invention, the pushing member and the cutting blade are in contact with each other in a direction substantially perpendicular to the direction in which the cutting blade is driven during the operation of either the forward path operation or the backward path operation. It is preferable to have a surface.
[0019]
Moreover, the extrusion molding apparatus of this invention is equipped with the cutting mechanism of one of the said extrusion molded products.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Next, an embodiment of an extrusion molded product cutting mechanism and an extrusion molding apparatus according to the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a schematic side view showing the overall configuration of the cutting mechanism of the present embodiment. In the extrusion molding apparatus of this embodiment, the cutting mechanism 20 arrange | positioned at the exit of the extrusion molding machine 10 is provided. The cutting mechanism 20 includes a molded product guide path 21 formed so as to extend along the extrusion direction of the extrusion molded product 3, and a molding speed detection unit 22 disposed on the upstream side of the molded product guide path 21. And a molded product cutting part 23 arranged on the downstream side of the molding speed detecting part 22.
[0021]
The molded product guide path 21 is connected to the internal guide path 11 provided inside the extrusion molding machine 10 so that the guide path is continuous, and includes a guide surface for guiding the extruded product 3. It has a terminal end after passing through the molding speed detection unit 22 and the molded product cutting unit 23. A discharge chute 24 for receiving the divided molded product and discharging the molded product in a housing (not shown) is disposed below the end portion of the molded product guide path 21.
[0022]
The molding speed detection unit 22 is rotatably contacted with a long extrusion molded product 3 traveling on the molded product guide path 21 from above, and the detection roller 22a is extruded with a predetermined pressure. And an elastic body 22 b such as a coil spring for pressing against the molded product 3. Then, when the detection roller 22a pressed against the extruded product 3 rotates with the progress of the extruded product 3, the amount of rotation of the detection roller 22a is detected by a detector such as an encoder, whereby the traveling speed of the extruded product 3 It is configured to measure (extrusion speed).
[0023]
Further, the molded product cutting unit 23 presses the extruded molded product 3 traveling on the molded product guide path 21 from above, and presses the extruded molded product 3 from above at a position adjacent to the downstream side of the pressed roller 231. A cutting blade (cutter) 232 for cutting. The suction nozzle 25 is disposed obliquely above the downstream side of the cutting blade 232, and this suction nozzle 25 is connected to an exhaust device (not shown), and chips generated when the extruded product 3 is cut by the cutting blade 232 are removed. It comes to suck. The molded product 3a cut to a predetermined length by the cutting blade 232 eventually falls onto the discharge chute from the molded product guide path 21 as the extruded product 3 advances, and is discharged.
[0024]
FIG. 2 is a side view of the molded product cutting portion 23, and FIG. 3 is a front view of the molded product cutting portion 23 (a surface seen from the downstream side of the molded product guide path 21 is a front surface). The molded product cutting part 23 is provided with a plate-like fixing member 233 fixed above the molded product guide path 21 so as to straddle the molded product guide path 21. A plate-like support member 234 is attached to the fixing member 233 so as to be movable up and down along the plate surface of the fixing member 233. The lower end of the screw shaft 235 is fixed to the support member 234. The screw shaft 235 is indirectly screwed to the fixing member 233, and the screw shaft 235 is rotated, so that the support member 234 is fixed to the fixing member 233. On the other hand, it can be moved up and down.
[0025]
A driving source 2381 composed of a plunger type electromagnetic solenoid or the like is fixed to the support member 234, and a driving shaft 2382 of the driving source 2381 is fixed to the driven member 2384 via a connecting member 2383. The driven member 2384 is guided in the horizontal direction with respect to the support member 234 by a linear guide 234a. An extrusion member 2385 is rotatably attached to the driven member 2384. The push-out member 2385 has a rotation range limited by a stopper 2384a provided on the driven member 2384 so that the push-out member 2385 does not turn counterclockwise in FIG. However, the pushing member 2385 is configured to be rotatable clockwise from the illustrated state. Further, the other end of an elastic member 2386 such as a coil spring whose one end is fixed to the driven member 2384 is connected to a portion of the pushing member 2385 near the upper end in the drawing. By this elastic member 2386, the pushing member 2385 is always urged in the counterclockwise direction of rotation shown in the drawing.
[0026]
At the lower end portion of the pushing member 2385, an inclined surface 2385a facing obliquely downward on the left side in FIG. 3 is formed, and a vertical surface 2385b facing rightward in the drawing is formed.
[0027]
Below the driven member 2384 is disposed a cutting support 2388 attached to the support member 234 so as to be movable up and down. A driven member 2387 protruding below the push-out member 2385 is disposed above the cutting support 2388. It is fixed. Further, the cutting blade 232 is fixed to the cutting support 2388. The cutting support 2388 is connected to the other end of an elastic member 2389 made of a coil spring or the like with one end attached to the support member 234, and the cutting support 2388 is always urged upward by the elastic member 2389.
[0028]
At the upper end of the driven member 2387, an inclined surface 2387a is formed, which is directed obliquely upward to the right in the drawing in FIG. 3, and a vertical surface 2387b is formed that is directed to the left in the drawing.
[0029]
The cutting edge 232a of the cutting blade 232 is formed in a convex arc shape corresponding to the cross-sectional shape of the extruded product 3, that is, the arc-shaped cross section. Further, the cutting edge 232 a of the cutting blade 232 is gradually thinned toward the tip end by forming the inclined blade surface 232 b on the downstream side of the molded product guide path 21.
[0030]
On the other hand, as shown in FIG. 3, the molded product guide path 21 has a V-shaped V-shaped cross section formed on the upper surface of the base body 211 fixed on the frame 210 via a vibration absorber 215 such as an anti-vibration rubber. The support guide member 212 is accommodated so as to fit in the V groove. The support guide member 212 is held on the base by a holding frame 213 attached to the base 211. A guide member 214 made of a soft material is fixed to the support guide member 212 to such an extent that the cutting edge 232a of the cutting blade 232 is not damaged. In this embodiment, since the extruded product 3 is formed in a bowl shape having an arc-shaped cross section, the surface of the guide member 214 is provided with an arc-shaped cross section corresponding to the bowl shape that is the shape of the extrusion molded product 3. A guide groove 214a is formed. The extruded product 3 is pushed into the guide groove 214a.
[0031]
Further, attachment support members 216 are attached and fixed to both side portions of the base body 211, and an arm member 236 is rotatably attached to the upper end portion of the attachment support member 216. Further, the pressing roller 231 is rotatably supported at the tip of the arm member 236. An elastic support portion 237 including an elastic member such as a coil spring is connected to the upstream end portion of the arm member 236. Here, since the shaft member is fixed to the arm member 236, and this shaft member is always biased upward by the elastic member, the arm member 236 always acts to press the pressing roller 231 downward with a predetermined pressure. .
[0032]
In the present embodiment, the extrusion speed of the extrusion-molded product 3 is detected by the rotation of the detection roller 22a in the molding speed detector 22, and a control device (not shown) (for example, a programmable controller or a microprocessor unit) is detected according to the extrusion speed. Etc.) operate the molded product cutting section 23 to cut the extruded molded product 3. That is, if the extrusion speed increases, the interval of the cutting operation by the molded product cutting unit 23 is shortened, and if the extrusion speed decreases, the interval of the cutting operation is increased. For example, when the extruded product 3 is cut to a certain length, if the extrusion speed is constant, the cutting operation is performed at a constant time interval, and if the extrusion speed increases or decreases, the time interval of the cutting operation is increased. Shorten or extend.
[0033]
Further, as a method for controlling the cutting operation by the molded product cutting unit 23, a detection device 26 including an optical sensor is disposed in the vicinity of the end portion of the molded product guide path 21 as shown in FIG. When the front end portion of the extrusion molded product 3 is detected by H.26, the molded product cutting unit 23 may be operated by the control device to be cut. In this case, the molding speed detection unit 22 is used for monitoring the extrusion speed of the extruded product 3.
[0034]
In the molded product cutting unit 23, based on the control signal from the above-described control device, first, the drive source 2381 shown in FIG. 3 is operated and the drive shaft 2382 is drawn, and the driven member 2384 is connected via the connection member 2383 accordingly. Move to the left side of the figure. As the driven member 2384 moves, the pushing member 2385 also moves to the left in the figure, and the inclined surface 2385a of the pushing member 2385 collides with the inclined surface 2387a of the driven member 2387. At this time, since the pushing member 2385 is prevented from rotating counterclockwise by the stopper 2386, the inclined surface 2385a pushes the inclined surface 2387a as it is, so that the driven member 2387 is lowered together with the cutting support 2388. Then, the cutting blade 232 attached to the cutting support 2388 is also lowered, so that the cutting blade 232 cuts the lower extruded product 3.
[0035]
When the pushing member 2385 pushes the driven member 2387 downward, passes over the driven member 2387, and moves to the left side in the figure (shown by a dashed line in the figure), the cutting support 2388 and the cutting blade 232 are removed from the pushing member 2385. It is released from the stress and starts to return upward by the elastic force of the elastic member 2389.
[0036]
Next, the drive source 2381 causes the drive shaft 2382 to protrude in the opposite manner to the above operation, and along with this, the pushing member 2385 starts to return to the right side in the drawing. At this time, since the driven member 2387 has already risen or is in the process of rising, the vertical surface 2385b of the tip of the pushing member 2385 that has started to return collides with the vertical surface 2387b of the tip of the driven member 2387. At this time, the impact applied to the driven member 2387 from the pushing member 2385 is applied in the horizontal direction, so that the driven member 2387 and the cutting support 2388 and the cutting blade 232 integrated with the driven member 2387 are moved upward or downward. It is designed to have little effect. Further, since the pushing member 2385 is attached to the driven member 2384 so as to be rotatable in the clockwise direction in the drawing, when the vertical surface 2385b collides with the vertical surface 2387b, the pushing member 2385 is moved to the two-dot chain line in the drawing by the reaction. As shown, it rotates clockwise and passes over the driven member 2387 so as to avoid the driven member 2387. Finally, the pushing member 2385 returns to the initial position on the right side of the figure, and is rotated in the direction opposite to the above rotation direction by the elastic force of the elastic member 2386 to return to the initial position, as shown by the solid line in the figure. become.
[0037]
Here, for example, an electromagnetic solenoid configured such that the drive shaft 2382 is pulled in during the energization period and the drive shaft 2382 is restored by an elastic force or the like when the energization is released can be used as the drive source 2381. . In this case, the energization time is about 1 second. Thus, even if the energization time (or energization cycle) is long or the response speed (operation start point) of the operation of the drive shaft 2382 is slow, the lowering speed and ascent of the cutting blade 232 are increased by the mechanism described above. Since the speed is determined by the pull-in speed of the drive shaft 2382 and the elastic force of the elastic member 2389, the operation of the cutting blade can be speeded up without being significantly affected by the operation characteristics of the drive source 2381.
[0038]
In the present embodiment, for example, when the extruded product 3 is moving at a predetermined speed from the right side in FIG. 1 to the left side in the drawing, the cutting blade 232 descends from above and the cutting edge 232a comes into contact with the surface of the extruded product 3. Then, when it is further lowered and lowered by the thickness of the extruded product 3, the extruded product 3 is completely cut. Thereafter, the cutting blade 232 moves up again and separates from the extruded product 3.
[0039]
At this time, while the cutting blade 232 is cutting the extruded product 3, the extruded product 3 is moving toward the left side in the drawing, so that the cutting period (the cutting blade 3 actually moves the extruded product 3). The period gradually moves to the left side in the figure as well. Therefore, strictly speaking, the cutting blade 232 is pushed and bent to the left in the drawing by the upstream extrusion 3, and at the same time, the upstream extrusion 3 is pushed back to the right by the cutting blade 232. At this time, the cutting blade 232 is formed with an inclined blade surface 232b for forming the blade edge 232a only on the downstream side, that is, the left side of the blade surface shown in FIG. Since it is formed perpendicularly, the cutting blade 232 is pushed and bent downstream, compared to the case where the inclined surface is also formed on the upstream blade surface or only on the upstream blade surface. Since both the amount of the extruded product 3 and the amount by which the upstream extrusion product 3 is pushed back to the upstream side can be reduced, the cutting position of the extrusion product 3 can be made more accurate, and the cutting surface can be made more It can be formed vertically, and damage to the extruded product 3 can be further reduced.
[0040]
As described above, during the cutting operation of the extrusion-molded product 3 by the cutting blade 232, the movement of the extrusion-molded product 3 in the extrusion direction is hindered by the cutting blade 232, and the extrusion-molded product 3 located upstream from the cutting site. Compressive stress is applied to. This compressive stress is absorbed to some extent by the deflection of the extruded product 3. On the other hand, in the present embodiment, the extruded product 3 is pressed against the molded product guide path 21 by the detection roller 22 a disposed at the outlet of the extrusion machine 10 and the pressing roller 231 adjacent to the cutting blade 232. The compressive stress is bent so as to separate from the molded article guide path 21 between the pressing portion by the detection roller 22a and the pressing portion by the pressing roller 231, and between the two pressing portions as shown by a one-dot chain line in FIG. Curved in an arcuate shape.
[0041]
At this time, since the extrusion molding machine 10 is disposed further upstream of the detection roller 22a, the bending of the extrusion molded product 3 generated between the detection roller 22a and the pressing roller 231 is illustrated in the extrusion molding machine 10. There is almost no effect up to the exit, and there is almost no effect on the molding state of extrusion molding.
[0042]
Next, after the cutting blade 232 descends and completely cuts the extruded product 3, the cutting blade 232 starts to rise. Even during the rising period of the cutting blade 232, the upstream extrusion product 3 continues to be prevented from moving until the cutting blade 232 completely separates from the upstream extrusion product 3. Therefore, the degree of curvature of the extruded product 3 indicated by the one-dot chain line in FIG. 4 also increases during this period as described above.
[0043]
Further, during the rising period of the cutting blade 232, as shown by the dotted line in FIG. 5, as the cutting blade 232 is lifted, the upstream cut end of the extrusion-molded product 3 tends to rise upward. At this time, the pressing roller 231 adjacent to the upstream side of the cutting blade 232 prevents the cut end portion of the extruded product 3 from rolling up, so that the extruded product 3 can be prevented from being damaged greatly.
[0044]
In order to further enhance the above effect, it is preferable that the cutting blade 232 itself shown in FIG. 2 is installed slightly inclined toward the downstream side toward the extruded product 3 and is lowered in the inclination direction. If it does in this way, since it cuts from the upstream side with respect to the extrusion molded product 3 progressing to the left side in the figure and proceeds to the oblique downstream side, the movement amount of the extrusion molded product 3 is set to the cutting blade 232 during the above-mentioned cutting period. The amount of cutting can be reduced by the amount of cutting, and as a result, the cut surface of the extruded product 3 can be formed closer to the vertical surface. Moreover, the damage given to the extrusion molded product 3 can further be reduced similarly to the above.
[0045]
Here, the inclination angle of the cutting blade 232 with respect to the perpendicular is preferably in the range of 1 to 5 degrees, and more preferably in the range of 2 to 3 degrees, in the configuration of the cutting mechanism of the present embodiment. If it falls below these ranges, the above-mentioned effect cannot be obtained, and if it exceeds these ranges, cutting failure may occur.
[0046]
In this embodiment, the pushing member 2385 is moved in the horizontal direction by the operation of the drive source 2381, the pushing member 2385 is collided with the driven member 2387 in the middle of the forward movement, and the cutting blade 232 is lowered, and then the cutting blade 232 is moved. Is increased by the elastic force of the elastic member 2389, and the return path operation of the pushing member 2385 does not hinder the raising of the cutting blade 232, so that it is not affected by the acceleration / deceleration characteristics in the reciprocating operation of the pushing member 2385. The cutting blade 232 can be moved up and down very quickly, and the time lag between the end time of the lowering operation of the cutting blade 232 and the start time of the ascending operation can be reduced.
[0047]
FIG. 6A shows a graph showing the lifting and lowering operation of the cutting blade 232 of this embodiment, and FIG. 6B shows a vertical drive shaft installed in a vertical posture of an electromagnetic solenoid (the same as the drive source 2381). The graph which shows the raising / lowering operation | movement of a cutting blade at the time of providing the cutting mechanism comprised by fixing a cutting blade to is shown. As can be seen from these graphs, in the present embodiment, the time between the end of the lowering operation of the cutting blade and the start of the ascent operation is extremely small. The period in which the extruded product is in contact (S1) is significantly shorter than the conventional cutting operation period S2. Also, the lifting / lowering operation period of the cutting blade (the period from the time when the cutting blade starts to descend to the time when the lifting is completed) T1 is also shorter than the conventional lifting / lowering operation period T2. In this embodiment, since the raising / lowering speed of the cutting blade itself is also higher than the operation speed of the cutting blade directly connected to the drive source, the cutting operation period S1 is significantly shortened compared to the case of a normal cutting mechanism. It is possible.
[0048]
In addition, the cutting mechanism and the extrusion molding apparatus of the extrusion molded product of the present invention are not limited to the illustrated examples described above, and it is needless to say that various modifications can be made without departing from the gist of the present invention. .
[0049]
【The invention's effect】
As described above, according to the present invention, the extruded product is pressed against the molded product guide path at two locations by the first pressing member and the second pressing member. Even if the movement of the extruded product is suppressed at the cutting site when the pressed product is cut by the cutting blade, the extruded product is pressed by bending between the two pressed sites. The continuous extrusion amount of the molded product can be absorbed. As a result, it is not necessary to give a large extrusion resistance to the extrusion molding part (the part where the molding material is extruded from the die) in the extrusion molding product, and the occurrence of the shape defect of the extrusion molding product can be suppressed. Therefore, even when the cutting mechanism is fixed, it is possible to reduce misalignment of the cutting position and damage to the extruded product without interrupting the extrusion. In addition, since the first pressing member is provided on the upstream side of the cutting blade, when the cutting blade leaves the cut portion of the extruded product after cutting the extruded product, the upstream side of the extruded product is moved together with the separating operation of the cutting blade. It is possible to prevent the side portion (this portion is in a state of being pressed against the cutting blade when being continuously extrusion-molded) from being greatly swung up in the separating direction of the cutting blade. it can.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram showing the overall configuration of an embodiment of an extrusion molded product cutting mechanism and an extrusion molding apparatus according to the present invention.
FIG. 2 is a side view of a molded product cutting part according to the embodiment.
FIG. 3 is a front view of a molded product cutting portion according to the embodiment.
FIG. 4 is a schematic configuration diagram showing a curved shape of an extruded product 3 during cutting in the same embodiment by a one-dot chain line.
FIG. 5 is an enlarged side view of the graph showing the curved shape (dashed line) of the extruded product 3 during cutting and the raised state (dotted line) of the extruded product 3 by raising the cutting blade in the same embodiment.
FIG. 6 is a graph (a) showing the lifting and lowering operation of the cutting blade in the same embodiment and a graph (b) showing the lifting and lowering operation of the cutting blade when driven directly by an electromagnetic solenoid.
[Explanation of symbols]
10 Extruder
20 Cutting mechanism
21 Molded product guideway
22 Molding speed detector
23 Molded product cutting part
231 Press roller
232 cutting blade
232a cutting edge
232b Inclined blade surface
2381 Drive source
2385 Extruded member
2385a inclined surface
2385b vertical surface
2386, 2389 Elastic member
2387 driven member
2387a Inclined surface
2387b vertical surface
2388 Cutting support

Claims

In the cutting mechanism of the extruded product for cutting the extruded product extruded by extrusion molding,
A molded product guide path extending in the extrusion direction of the extruded molded product, and a molded product cutting means provided with a cutting blade for cutting the extruded molded product proceeding along the molded product guide path,
The molded product cutting means includes a first pressing member that presses the extruded product toward the molded product guide path, and a second pressing member that presses the extruded molded product toward the molded product guide path. It is,
The molded product cutting means is provided with drive means for driving the cutting blade,
The drive means is configured to push the cutting blade toward the extrusion-molded product, and is configured not to substantially interfere with the cutting blade except for a period during which the cutting blade is pushed out. And a retracting means for biasing the cutting blade in a direction for retracting the cutting blade from the extruded product side,
The extruding member is configured to reciprocate in a direction intersecting the direction in which the cutting blade is driven, and the cutting blade is moved by the extruding member during the operation of either the forward path operation or the backward path operation of the extruding member. Constructed to be extruded towards the extrusion,
At least one of the cutting blade and the extruding member is provided with the extrusion for abutting against the other party in the middle of one of the forward path operation and the backward path operation to push the cutting blade toward the extrudate. An inclined surface oriented in an intermediate direction between a reciprocating direction of the member and a direction in which the cutting blade is driven, and the push-out member avoids the cutting blade in one of the forward operation and the backward operation Configured to do
The pusher member is configured to rotate in a direction to avoid the cutting blade when contacting the cutting blade during the other operation of the forward path operation and the backward path operation. And a posture return means for biasing the pushing member in the opposite direction,
The pushing member and the cutting blade include contact surfaces that contact each other in a direction substantially orthogonal to a direction in which the cutting blade is driven during the operation of either the forward path operation or the backward path operation. A cutting mechanism for an extrusion-molded product characterized by comprising:

In Claim 1, It has an extrusion speed detection means which detects the extrusion speed of the extrusion molding, and the 2nd press member contacts the extrusion molding which advances along the molding guide way, and An extrusion roller that rotates in accordance with the movement of the extruded product, and the extrusion speed detecting means is configured to detect the extrusion speed of the extruded product based on the rotation of the detection roller. Cutting mechanism for molded products.

The first pressing member according to claim 1 or 2, wherein the first pressing member is a pressing roller that contacts the extruded product that travels along the molded product guide path and rotates according to the movement of the extruded product. A cutting mechanism for extruded products.

The extrusion molding apparatus provided with the cutting mechanism of the extrusion molded product of any one of Claim 1 thru | or 3.