JP2004216018A - Needle plate of sewing machine - Google Patents

Needle plate of sewing machine Download PDF

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Publication number
JP2004216018A
JP2004216018A JP2003009288A JP2003009288A JP2004216018A JP 2004216018 A JP2004216018 A JP 2004216018A JP 2003009288 A JP2003009288 A JP 2003009288A JP 2003009288 A JP2003009288 A JP 2003009288A JP 2004216018 A JP2004216018 A JP 2004216018A
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Japan
Prior art keywords
thread
needle
upper thread
sewing machine
sewing
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JP2003009288A
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JP4253192B2 (en
Inventor
Masanori Yamagishi
正則 山岸
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Juki Corp
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Juki Corp
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Abstract

<P>PROBLEM TO BE SOLVED: To sufficiently secure the remaining length of a needle thread in a sewing needle after thread cutting and to surely perform thread cutting. <P>SOLUTION: The needle plate 20 of a sewing machine is provided with a thread cutter 110 for cutting the needle thread, and a shuttle mechanism 103 provided under the thread cutter 110 for passing a bobbin thread through a loop of the needle thread. Besides, the thread cutter 110 is equipped with a moving scalpel 111 for forward movement of a reciprocating and turning action along with an approximately horizontal direction to sort the needle thread to be the upstream side of the shuttle mechanism 103 and for backward movement to carry a needle thread U1 which is on the downstream side of the shuttle mechanism 103, to a cutting position, and a thread hauling member 112 for locking the needle thread U1 selected by the moving scalpel 111 to be located on the upstream side. The needle plate 20 of the sewing machine is then equipped with a needle hole 23 where a sewing needle 15 is inserted and on its lower side surface, a thread guide groove 24 is provided approximately along with the same direction from a terminal portion of the needle hole 23 on the side of a reciprocating direction F of the moving scalpel 11. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

【0001】
【発明の属する技術分野】
本発明は、ミシンの針板に係り、特に糸切り装置を備えるミシンに用いられる針板に関する。
【0002】
【従来の技術】
糸切り装置110を備える従来のミシンについて説明する。このミシンは、図7に示すように、縫い針101が挿入される針穴102を備える針板と、針板の下方に設けられ,上糸及び下糸の切断を行う糸切り装置110と、糸切り装置110の下方に設けられ,上糸によるループに下糸を挿通させる釜機構103とを備えている。
なお、縫製時には、上糸Uは図示しないミシンの上方に位置する上糸供給源から、上糸Uの送りに対して調節可能な摩擦力を加えて張力を付与する図示しない糸調子及び所定のタイミングで上糸Uの引き上げを行う図示しない天秤を介して縫い針に至り、さらに、縫い針の糸通し穴に通されて布地に至る。一方、下糸Dは、釜機構103の内部に位置する図示しないボビンから繰り出され、針穴102から針板の上方の布地に至るようになっている。この上糸及び下糸は縫い針の上下動と釜機構との協働により交絡され、当該布地に縫い目を形成する。
【0003】
また、上記糸切り装置110は、図9に示すように、往復回動する動メス111と、動メス111の往動方向の回動により運ばれる上糸が係止される糸たぐり部材112と、動メス111の復動方向の回動により運ばれる上糸と下糸とを切断する固定メス113とを備えている(例えば、特許文献1参照)。
なお、上糸の縫い針101から釜機構103に至るまでの部分を上流側部分U1とし、釜機構103から布地に至るまでの部分を下流側部分U2とする。そして、動メス111は、その往動により上糸の上流側部分U1を糸たぐり部材112に係止し、復動により上糸の下流側部分と下糸Dとを固定メスに運ぶ。
【0004】
前述の図7と図8とに基づいて、縫製完了後の上糸の切断動作を説明する。縫製時には、釜機構103により捕捉された上糸ループに対して、釜機構の中釜をくぐらせる動作が行われる。中釜からは下糸が繰り出されることから、中釜をくぐらせることで上糸ループに下糸が挿通される。上糸の切断動作は、上記釜機構の動作の途中の過程から開始される。
即ち、中釜のほぼ半分までを上糸ループにくぐらせると、上糸の上流側部分U1は、中釜に対して一方の面側に位置し、上糸の下流側部分U2及び下糸Dは、中釜に対して他方の面側に位置する状態となる(図7(A))。
そして、上述のように並んだ上糸U1,U2及び下糸Dに対して動メス111が作動し、往動方向(図7における時計方向)の回動を行い、動メス111の往動方向側に向けられた尖部111cで上記上糸U1,U2及び下糸Dを選り分け、凹部111aにより上糸U1のみを捕捉して往動方向に運ぶ(図7(B))。さらに、動メス111は、糸たぐり部材112まで上糸U1を運び、糸たぐり部材112に上糸U1を係止する(図7(C))。
その後、上糸ループに対して中釜がくぐる状態が終了し、動メス111は復動方向に移動方向が切り替わり、動メス111の復動方向に設けられた凹部111bにより上糸U2及び下糸Dを捕捉する(図8(A))。かかる時点で、上糸は糸調子による張力付与状態を緩められ、下糸は当初から低張力状態であるため、動メス111によりその復動方向に容易に運ばれる。
そして、復動方向の移動先に設けられた固定メス113と動メス111との間に上糸U2及び下糸Dが挟まれて、これらの切断が行われる(図8(B))。
なお、図7,8にあってはその説明を明確に行うために上糸U1とU2との間隔は実際より離間して図示しているが、これらは実際には釜機構103の構造上、より近接している。
【0005】
【特許文献1】
特開平10−258196号公報(第5図)
【0006】
【発明が解決しようとする課題】
しかしながら、上記従来例は、糸切り装置110の動メス111により上糸の上流側部分U1を選別する場合に、糸切り装置110の上方に位置する針穴102の穴幅に応じて上糸が穴幅方向に振れ、位置が安定しない為、U1を選別できなかったり、動メス111の往動方向側凹部111aから外れて、糸たぐり部材112に係止できない場合があった。
糸たぐり部材112は、切断後の縫い針101に残る上糸の長さを稼ぐために設けられており、上糸が係止されない場合、縫い針101の残り長さが極端に短くなる。すると、次の縫製の際に縫い針から上糸が脱離し、縫製ミスを生じ易くなる、という不都合があった。
【0007】
これを防止するためには、糸たぐり部材112を針落ち位置Oのより近傍に配置するか動メス111の往動方向側に設けられた凹部111aの深さdを深く形成するという方法が考えられるが(図9参照)、前者の場合は、結局のところ、縫い針101の上糸の残り長さを短くしてしまうという問題を生じてしまう。
【0008】
また、後者の場合には、凹部111aの深さdだけ往動方向に余分に動メス111を回動させなければならず、その回動スペースを確保する都合上、同方向についての糸切り装置110の大型化を生じてしまう、という問題があった。
糸切り装置110は、釜機構の釜軸の軸線方向(以下、釜軸方向とする)に沿って並ぶ上糸U1,U2,下糸Dとの中から上糸U1のみを選別する機能上、動メス111の回動方向は釜軸方向に直交する方向に沿わせる必要があり、一方、釜機構は一般に縫い針101の駆動モータから分岐して動力を付与されることから釜軸方向はミシンベッドの長手方向に沿っている場合が多い。
その場合、糸切り装置が動メスの回動方向に大型化を生じると、ミシンベッドがその長手方向に直交する方向(幅方向)に大型化を生じることとなる。かかる場合、ミシンベッドの先端部が小径の筒状とされるシリンダベッドミシンのように、ミシンベッドの幅が小さいミシンについては、特に、動メスの凹部を深くするという方法を採ることはできず、縫い針に残る糸端長さを十分に確保することができなかった。従って、切断後、縫い針から上糸が外れてしまうという問題を解決することはできなかった。
【0009】
さらに、上記従来例のもう一つの問題点を図10に基づいて説明する。かかる図10は前述した図8(B)の状態を、釜軸に沿った方向から見た説明図である。なお、前述の動作説明図7,8はわかりやすく図示する都合上、各構成の上下間隔を広く表しているが、実際は、図10に示すように、各構成は接近する配置が採られている。
図10によれば、上糸Uは各構成に対して随所で著しく屈曲し、その結果、随所で摺動摩擦を生じて上糸の供給源側から上糸を十分に引き出すことができず、切断後の縫い針101における上糸の残り長さが十分に確保することができないという不都合を生じていた。
【0010】
また、針板の下方となる面と針穴の内面との境界は、曲率半径を大きな曲面形状とすることが縫製の仕上がりに不適であることから十分に摩擦低減を図られておらず、糸たぐり部材に係止された上糸は針穴内面の下端部において高い摩擦力を受けて、切断後の縫い針101における上糸の残り長さが十分に確保することができないという不都合を生じていた。
【0011】
本発明は、糸切り装置による上糸切断後の縫い針における上糸の残り長さを充分に確保すると共に確実に糸切りを行うことをその目的とする。
また、より望ましくは、縫い針の上糸の残り長さを確保しつつも糸切り装置の大型化を防止することを他の目的とする。
【0012】
【課題を解決するための手段】
請求項1記載の発明は、上糸及び下糸の切断を行う糸切り装置と、糸切り装置の下方に設けられ,上糸によるループに下糸を挿通させる釜機構と、を備えると共に、糸切り装置は、略水平方向に沿った往復回動動作の往動により釜機構に対して上流側となる上糸を選別し,復動により釜機構に対して下流側となる上糸を切断位置に運ぶ動メスと、当該動メスに選別された上流側となる上糸を係止する糸たぐり部材とを備えるミシンのミシンベッド上面に設けられる針板であって、縫い針が挿入される針穴を備えると共に、その下方側となる面に、針穴の動メスの往動方向側の端部から同方向にほぼ沿うように針穴よりも幅が狭い糸案内溝を設ける、という構成を採っている。
【0013】
上記記載中「往動」とは、往復回動する動メスの一方の方向への回動動作をいい、「復動」とは、往復回動する動メスの他方の方向への回動動作をいう。
上記構成では、縫い針が針穴を通って下方に位置するときに、釜機構が上糸を捕捉し、ループを形成する。そして、上糸が釜機構に係合すると、釜機構の上方において、釜機構に対して上流側となる上糸と下流側となる上糸とが並んだ状態となる。これらに対して、糸切り装置の動メスがその往動により釜に対して上流側となる上糸のみを選別して捕捉し、糸たぐり部材まで運ぶ。
【0014】
このとき、上流側の上糸は上下方向に沿った状態から動メスの往動方向側に傾斜し、針穴に接触する部分では、当該針穴の往動方向側の端部において当該往動方向に向かって形成された糸案内溝に入り込んだ状態となる。
かかる糸案内溝は、少なくとも針穴の同方向幅よりも狭ければよいが、例えば、糸が入り込むことができ且つこの溝に沿って糸が摺動可能であって可能な限り狭いことが望ましい。
そして、このように糸案内溝に入り込んだ状態で上糸は糸たぐり部材まで運ばれるために、針穴の幅の範囲で両側に振れる状態の発生が効果的に抑制される。また、上糸が糸案内溝に入り込んだ状態は、切断が終了するまで維持されるので、糸たぐり部材に係止された状態以降も継続して上糸の振れは抑制される。
このため、上糸の動メスからの不慮の脱離が効果的に抑制されることとなり、縫い針における切断後の上糸の残り長さが適正に確保される。
【0015】
また、上糸が糸案内溝に入り込んだ場合、針穴から糸たぐり部材に渡る上糸の傾斜角度及び糸たぐり部材の前後における上糸のなす角度の屈曲の度合いが緩和され、動メスの移動による上糸の引き出し動作が円滑に行われることとなる。従って、上糸は動メスの移動により円滑に送られ、縫い針における切断後の上糸の残り長さが適正に確保される。
【0016】
請求項2記載の発明は、請求項1記載の発明と同様の構成を備えると共に、針穴の内面と針板の下方側となる面との境界とを曲面で連ねると共に,針穴の内面と糸案内溝の底面との境界を曲面で連ね、針穴の内面と針板の下方側となる面と間の曲面よりも,針穴の内面と糸案内溝の底面と間の曲面の曲率半径を大きくする、という構成を採っている。
【0017】
上記構成では、請求項1記載の発明と同様の作用を奏すると共に、上糸が糸たぐり部材に係止された状態において、上糸は糸案内溝内に入り込むので、針穴内面と針板の下方となる面との境界部に接することがなく、より曲率半径の大きな針穴内面と糸案内溝の底面との境界に設けた曲面に接する状態となるので、動メスの移動による上糸の送り動作が円滑に行われることとなる。従って、上糸は動メスの移動により円滑に送られ、縫い針における切断後の上糸の残り長さが適正に確保される。
なお、かかる場合、糸案内溝は通常の縫製に際しては、上糸が入り込むような配置ではないことから、上述のように曲率半径の大きな曲面を設けたことによる縫製に対する影響を及ぼすことはない。
【0018】
【発明の実施の形態】
本発明に実施形態を図1乃至図5に基づいて説明する。図2は本発明の実施形態たるシリンダベッドミシン10の斜視図である。かかるシリンダベッドミシン10は、その外形的な概略が、その下部に位置するミシンベッド11と、ミシンベッド11の一端部から上方に立ち上げられたミシン胴部12と、ミシン胴部12の上方からミシンベッド11に沿うように延設されたミシンアーム13とから構成されている。
そして、ミシンベッド11は、ミシン胴部12とは反対側の端部にミシンベッド11の長手方向に沿って延設された略筒状のシリンダ形状部14が設けられている。
なお、ミシン10の構成を説明するにあたって、後述する縫い針15の上下動方向をZ軸方向とし、これと直交する方向であってミシンベッド11及びミシンアーム13の長手方向をY軸方向とし、Z軸方向及びY軸方向の双方に直交する方向をX軸方向とする。
【0019】
シリンダベッドミシン10は、ミシンアーム13の先端部に設けられ,ミシンモータ(図示略)により上下方向に往復駆動する縫い針15と、ミシンアーム13の上部に設けられ,縫い針15に上糸を供給するための図示しない上糸供給源と、この上糸供給源と縫い針15との間で上糸を所定の荷重で挟持してその送り方向の移動に所望の抵抗力を発生させる糸調子装置16と、この糸調子装置16と縫い針15との間で所定のタイミングで天秤17により上糸の引き上げを行う天秤装置と、ミシンベッド11のシリンダ形状部14の上面に設けられ,縫い針15の先端部を挿通させる針穴21が設けられた針板20と、シリンダ形状部14内であって針板20の下方に設けられ,上糸及び下糸の切断を行う糸切り装置110と、糸切り装置の下方に設けられ,上糸によるループに下糸を挿通させる釜機構103とを備えている。
【0020】
(釜機構)
図3は、針板20の下方に位置する構成をY軸方向から見た概略構成図である。 上記釜機構103は、前述した従来例の釜機構と同じ構成のものであるため、各図中では、その全体的な形状を二点鎖線でのみ示すものとし、重複する説明は省略する。
釜機構103は、シリンダ形状部14内において糸切り装置110の下方に配置され、下糸の供給源となるボビンを内部に備える中釜と、中釜の外周に回転可能に設けられ,剣先により上糸ループを捕捉する外釜と、ミシンモータの駆動力が伝達されて外釜を回転駆動する釜軸とを備えている(各構成についてはいずれも図示略)。そして、釜軸はY軸方向に沿って配設されると共にシリンダ形状部14の先端部側と同じ側の端部に中釜及び外釜が配置されている。
【0021】
中釜はその内部に位置するボビンから下糸の繰り出しを行う一方で、外釜は回転動作により剣先で捕捉した上糸ループに中釜をくぐらせる。この動作により、上糸ループに下糸が挿通された状態が形成され、その後の天秤機構による上糸の引き上げ動作により、縫い目が形成される。
【0022】
ここで、釜機構103により、上糸のループに中釜が半分くぐらされると、上糸は、中釜を挟んで折り返す状態となる。そして、上糸の中釜よりも上流側(より縫い針15に近い側)となる部分U1と、下流側(より布地の縫い目に近い側)となる部分U2とが、Y軸方向に沿って並んだ状態となる。そして、下流側の上糸U2は、上流側の上糸U1よりもシリンダ形状部14の先端側に位置する状態となる。また、このとき、下糸Dも上流側の上糸U1よりもシリンダ形状部14の先端側に位置する状態となる(図7(A)参照)。このように上糸U1,U2及び下糸DがY軸方向に沿って並んだ状態を利用して、糸切り装置110は、上流側の上糸U1のみを選別し、これ以外の切断を行うことを可能としている。なお、上糸についてU1とU2と別符号を付しているが、これらは釜機構103の下部においてつながっている。
【0023】
(糸切り装置)
糸切り装置110を図4及び図9糸切り装置110は、前述した従来例の糸切り装置と同じ構成のものであるため、重複する説明は省略する。
糸切り装置110は、シリンダ形状部14内において、糸たぐり部材112,動メス111,固定メス113の順番でX軸方向に沿って並んで配置されている。また、動メス111は、上述の釜機構によりY軸方向に沿って並ぶ上糸U1,U2及び下糸Dから上糸U1を選別する機能上、その回動端部がほぼX軸方向に沿って回動を行う。また、動メス111は、その回動端部はシリンダ形状部14の先端側、その基端部(回動中心側)はミシン胴部12側となるように配設されている。
【0024】
そして、動メス111の上糸U1を捕捉するための凹部111aは、動メス111の往動方向F側において回動半径方向について回動端部からやや回動中心寄りの位置に形成され、上糸U2及び下糸Dを捕捉するための凹部111bは、動メス111の往動方向B側において回動端部に位置している。これにより、Y軸方向に沿って並ぶ上糸U1,U2及び下糸Dの中から最も動メス111の回動中心に近い上糸U1のみを往動方向の回動により選別することを可能としている。
【0025】
(針板)
図1(A)は針板20の要部をX軸方向(図3における左側)から見た状態を示し、図1(B)は針板20の要部をY軸方向(図1(A)における左側)から見た状態を示し、図1(C)はZ軸方向(図1(A)における上側)から見た状態を示す。
針板20は、X−Y平面に沿ってシリンダ形状部14の上部に配設される板状部21と、板状部21における縫い針15の針落ち位置の下面側に設けられた円柱状の突起部22とを備え、これらをZ軸方向に沿って貫通する針穴23が形成されている。
針穴23は、上方向又は下方向から見てX軸方向に沿った長穴状に形成されている。そして、針板20の下方側となる面に相当する突起部22の下端面上において針穴23の動メス111の往動方向F側の端部からF方向に向かって糸案内溝24が形成されている。
【0026】
糸案内溝24は、針穴23の往動方向F側の端部の内面から突起部22の側面まで貫通した状態で形成されている。かかる糸案内溝24は、糸切り装置110による糸切断動作において動メス111が上糸U1を選別して糸たぐり部材112まで押して導く際に、上糸U1を入り込ませてY軸方向の振れを防止するために形成されている。
このため、糸案内溝24は、Y軸方向の幅が針穴23よりも狭く設定されている。当該糸案内溝24のY軸方向幅は、少なくとも針穴23よりも狭いことが必須であり、上糸U1のY軸方向の振れを防止する観点から、上糸U1が入り込むことが可能であって、内部での摺動を妨げない範囲でなるべく狭く設定することが望ましい。
【0027】
また、針穴23のF方向側端部において、Y軸方向の一方(図1(A)における左側)に偏った配置で形成されている。つまり、糸切り装置110における上糸U1の選別の際に、上糸U1,U2及び下糸Dの中で上糸U1がY軸方向の同じ方向に偏って位置しており、各糸の内での上糸U1の配置と針穴23における糸案内溝24の配置とを一致させることで、円滑に上糸U1を糸案内溝24内に導くことを可能としている。
【0028】
さらに、糸案内溝24は、その底面(溝としての底面、即ち、図1(A)(B)における上面)と針穴23のF方向側端部の内面との境界を曲面形状としている。図3に示すように、針穴23の内面と突起部22の下端面との境界も曲面形状に形成されているが、針穴23の下端部の曲面の曲率半径R1よりも糸案内溝24と針穴23との境界曲面の曲率半径R2の方が大きく設定されている。糸案内溝24と針穴23との境界曲面は上糸U1が摺接して移動するため、曲率半径R2はより大きく設定することが望ましい。一例を挙げると、曲率半径R1は0.3〜0.4[mm]、曲率半径R2は2〜3[mm]に設定される。
針穴23の下端部の曲面は、その曲率半径を大きく設定すると縫製に際してその仕上がりに影響を及ぼすことからせいぜい上記範囲内に設定されるが、糸案内溝24は、縫製にあっては上糸及び下糸に影響を与えない位置に設けられていることから、十分に大きく設定することが可能である。
【0029】
(実施形態の動作説明)
シリンダベッドミシン10の糸切り動作について説明する。糸切り装置110は従来例の説明と同じ動作を行うため、前出の図7,8を参照しつつ、図3〜図5に基づいて説明する。
まず、縫製終了時において、釜機構103により捕捉された上糸ループに対して、釜機構の中釜をくぐらせる動作が行われる。そして、中釜のほぼ半分までを上糸ループにくぐらせると、上糸U1,U2及び下糸Dは、X軸方向に沿って並び、上糸U2及び下糸Dは動メス111の回動中心から遠方に、上糸U1はやや回動中心よりに配置される(図7(A))。
【0030】
上述の状態において、動メス111は往動方向F側に向かって回動し、その凹部111aが上糸U1のみを捕捉して(図7(B))、糸たぐり部材112まで運んでいく。これにより、上糸U1は糸たぐり部材112に係止される(図7(C))。
かかる上糸U1の捕捉から運ばれる過程において、図4,5に示すように、当該上糸U1は針穴23から糸案内溝24内に入り込み、当該糸案内溝24の両側の側壁に阻まれてY軸方向の振れが防止された状態で動メス111に運ばれるため、当該動メス111の往動方向側凹部111aからの不慮の脱離は効果的に防止される。
【0031】
その後、上糸ループに対して中釜がくぐる状態が終了し、動メス111は復動方向Bに移動方向が切り替わり、動メス111の凹部111bにより上糸U2及び下糸Dを捕捉する(図8(A))。かかる時点で、上糸は糸調子による張力付与状態から開放され、上糸U2及び下糸Dは動メス111により固定メス113まで運ばれて切断が行われる(図8(B))。
【0032】
上記動メス111の復動の開始から切断が行われるまでの工程において、上糸U1は糸たぐり部材112に係止されていることから動メス111の復動により張力を受け、糸供給源から上糸の繰り出しが行われ、図3に示すように、糸案内溝24の開始端部や糸たぐり部材112において摺動しつつ下流側に移動を行うことになる。
つまり、上糸U1は糸案内溝24内において針穴23の内面との境界に形成された曲面と接触するが、当該曲面は十分にその曲率半径R2が大きく設定されているため、上糸U1は円滑に摺動し供給源からの繰り出しの妨げとならない。従って、切断後における縫い針15の上糸の残り長さが十分に確保される。
【0033】
また、図3と図10とを比較すると分かるように、糸案内溝24が未形成の場合(図10の場合)には、上糸U1は突起部の下端面から糸たぐり部材112で折り返すようにして固定メス113側に至り、突起部の下端面から糸たぐり部材112までの高さ方向の距離が短いために、糸たぐり部材112を介して折り返す上糸U1の両側部分のなす角度θ2は小さくなり、糸たぐり部材112において摺動摩擦を生じやすい。
一方、糸案内溝24を設けた場合(図3の場合)には、上糸U1は突起部22の針穴23の下端より上方となる糸案内溝24の底面から糸たぐり部材112で折り返すようにして固定メス113側に至るため、糸たぐり部材112までの高さ方向の距離を溝の深さ分だけ余分に確保することが可能となる。従って、糸たぐり部材112を介して折り返す上糸U1の両側部分のなす角度θ1は大きくなり、糸たぐり部材112における摺動摩擦を低減することが可能である。
従って、糸案内溝24の存在により、動メス111の復動時において上糸U1は円滑に摺動することで供給源からの良好な繰り出しを実現し、切断後における縫い針15の上糸の残り長さがより十分に確保される。
【0034】
(実施形態の効果)
以上のように、シリンダベッドミシン10にあっては、針板20の針穴23に糸案内溝24を設けたことにより、糸切り動作を行う際に、上糸U1が脱落を生じることなく動メス111により良好に糸たぐり部材112まで運ばれるため、高い信頼性をもって、縫い針15における切断後の上糸残り長さを十分に確保することが可能となる。これにより、次回の縫製時における上糸抜けによる縫製ミスの発生を効果的に抑制することが可能となり、シリンダベッドミシン10の信頼性も向上する。
【0035】
また、動メス111からの上糸U1の脱落を防止するために動メス111の凹部111aを深く形成する必要がなく、X軸方向における糸切り装置110の幅の大型化を回避することが可能となる。このため、シリンダベッドミシン10のシリンダ形状部14のようにX軸方向幅が狭い箇所に糸切り装置110を配設しても動メス111からの上糸U1の脱落を効果的に防止し、特に信頼性の向上を図ることが可能となる。
【0036】
また、糸案内溝24により上糸U1の脱落防止効果がより顕著であれば、動メス111の凹部111aをより浅くすることができ、ひいては、糸切り装置110のX軸方向幅を小型化し、さらに、シリンダ形状部14をより狭小化することも可能となる。
【0037】
(その他)
針板20は、突起部22を備え、その下端面に糸案内溝24を形成する構成としたが、突起部24を設けなくても良いことはいうまでもない。図6は、板状部21Aのみからなる針板20Aについて針穴23A及び糸案内溝24Aを設けた例を示す図であり、図6(A)は針板20Aを図1(A)と同じX軸方向から見た状態を示し、図6(B)は針板20Aの要部をY軸方向(図6(A)における左側)から見た状態を示し、図6(C)はZ軸方向(図6(A)における上側)から見た状態を示す。
【0038】
上記針板20Aは針板20と同様にシリンダベッドミシン10のシリンダ形状部に配設され、針穴23Aのその形状,向き,幅は前述の針穴23と同じである。また、糸案内溝24Aの向き,配置,幅,機能,その底面と針穴23Aの内面との境界曲面の曲率については糸案内溝24と同様である。
但し、糸案内溝24はその出口が突起部22の側面に設けられているのに対して、糸案内溝24Aは板状部21Aの下面に設けられている点が異なっているが、これはその機能上影響を及ぼすものではない。
かかる針板20Aも前述の針板20と全く同じ作用を奏し、全く同じ効果を得ることが可能である。
【0039】
【発明の効果】
請求項1記載の発明は、針穴に糸案内溝を設けたことにより、糸切り装置の動メスにより糸たぐり部材まで上糸が運ばれる際の糸振れを防止することができるので、上糸の動メスからの不慮の脱離を防止し、着実に上糸を糸たぐり部材に係止させることが可能となる。従って、高い信頼性をもって、縫い針における切断後の上糸残り長さを十分に確保すると共に確実に糸切りを行うことが可能となる。さらに、これにより、次回の縫製時における上糸抜けによる縫製ミスの発生を効果的に抑制することが可能となる。
【0040】
また、動メスの往動方向側に深い凹部を設ける必要がなく、その分、動メスの往復ストローク長を拡張する必要がなく、ひいては短縮することが可能となるため、糸切り装置の大型化を防止しさらには小型化を図ることが可能となる。
【0041】
さらに、糸切り装置の大型化を防止しさらには小型化図ることができることから、これをミシンベッドに装備する場合に、当該ミシンベッドの幅の拡大を防止しさらには小型化を図ることが可能となる。このため、ミシンベッド幅の小型化を必須とするシリンダベッドミシンにあっては、縫い針からの上糸脱離の防止が困難であったが、本発明によりこれを効果的に抑制することが可能となり、さらにはよりミシンベッド幅の縮小化を図ることが可能となる。
【0042】
また、糸案内溝を設けたことにより、上糸が入り込んだ場合、針穴から糸たぐり部材に渡る上糸の傾斜角度及び糸たぐり部材の前後における上糸のなす角度の屈曲の度合いが緩和されことになるため、屈曲部における摺動摩擦力を低減し、動メスの移動による上糸の送り動作を円滑に行わせることが可能となる。従って、上糸が動メスの移動により円滑に送られ、縫い針における切断後の上糸の残り長さを適正に確保することが可能となる。
【0043】
請求項2記載の発明は、針穴の内面と糸案内溝の底面との境界に他の部分より曲率半径の大きな曲面を形成したので、上糸が糸案内溝に入り込んだ場合、上記曲率半径の大きな曲面に接することとなる。従って、動メスの移動による上糸の送り動作を円滑に行わせることが可能となり、上糸が動メスの移動により円滑に送られ、縫い針における切断後の上糸の残り長さを適正に確保することが可能となる。
【図面の簡単な説明】
【図1】図1(A)は発明の実施形態たるシリンダベッドミシンに装備される針板の要部をX軸方向から見た状態を示し、図1(B)はY軸方向から見た状態を示し、図1(C)はZ軸方向から見た状態を示す。
【図2】発明の実施形態たるシリンダベッドミシンの斜視図である。
【図3】針板の下方に位置する構成をY軸方向から見た概略構成図である。
【図4】糸切り装置の要部と糸案内溝との関係を示すためにこれらを上方から見た説明図である。
【図5】糸切り装置の要部と糸案内溝との関係を示すためにこれらを斜方から見た説明図である。
【図6】図6(A)は針板の他の例をX軸方向から見た状態を示し、図6(B)はY軸方向から見た状態を示し、図6(C)はZ軸方向から見た状態を示す。
【図7】従来例の動作説明図であり、図7(A)〜(C)の順で進行する各工程を示している。
【図8】図7の工程に続く従来例の動作説明図であり、図8(A)〜(B)の順で進行する各工程を示している。
【図9】従来の糸切り装置を示す平面図である。
【図10】従来例における針板の下方に位置する構成を釜軸方向から見た概略構成図である。
【符号の説明】
10 シリンダベッドミシン
11 ミシンベッド
14 シリンダ形状部
20 針板
23 針穴
24 糸案内溝
103 釜機構
110 糸切り装置
111 動メス
112 糸たぐり部材
[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a needle plate of a sewing machine, and more particularly to a needle plate used for a sewing machine having a thread cutting device.
[0002]
[Prior art]
A conventional sewing machine including the thread cutting device 110 will be described. As shown in FIG. 7, the sewing machine includes a needle plate having a needle hole 102 into which a sewing needle 101 is inserted, a thread cutting device 110 provided below the needle plate, and for cutting an upper thread and a lower thread. A hook mechanism 103 is provided below the thread cutting device 110 and allows the lower thread to pass through the loop formed by the upper thread.
At the time of sewing, the upper thread U is supplied from an upper thread supply source located above a sewing machine (not shown) by applying an adjustable frictional force to the feed of the upper thread U to apply tension and a predetermined thread tension (not shown). The needle reaches the sewing needle via a balance (not shown) that pulls up the upper thread U at a timing, and further passes through the threading hole of the sewing needle to reach the fabric. On the other hand, the bobbin thread D is fed out from a bobbin (not shown) located inside the shuttle mechanism 103, and reaches from the needle hole 102 to the cloth above the needle plate. The upper thread and the lower thread are entangled by the vertical movement of the sewing needle and the cooperation of the shuttle mechanism to form a seam on the fabric.
[0003]
As shown in FIG. 9, the thread cutting device 110 includes a moving knife 111 that reciprocates and rotates, and a thread pulling member 112 that locks an upper thread carried by rotating the moving knife 111 in the forward movement direction. And a fixed knife 113 for cutting the upper thread and the lower thread carried by the rotation of the moving knife 111 in the backward movement direction (for example, see Patent Document 1).
The portion from the needle 101 of the upper thread to the shuttle mechanism 103 is referred to as an upstream portion U1, and the portion from the shuttle mechanism 103 to the fabric is referred to as a downstream portion U2. The moving knife 111 locks the upstream portion U1 of the upper thread to the thread pick-up member 112 by the forward movement, and carries the downstream portion of the upper thread and the lower thread D to the fixed knife by the backward movement.
[0004]
The cutting operation of the upper thread after completion of sewing will be described with reference to FIGS. 7 and 8 described above. At the time of sewing, the upper thread loop captured by the shuttle mechanism 103 is moved through the intermediate shuttle of the shuttle mechanism. Since the lower thread is fed from the inner hook, the lower thread is inserted into the upper thread loop by passing through the inner hook. The cutting operation of the upper thread is started from the middle of the operation of the shuttle mechanism.
That is, when almost half of the inner hook is passed through the upper thread loop, the upstream portion U1 of the upper thread is located on one surface side with respect to the inner hook, and the downstream portion U2 of the upper thread and the lower thread D Is located on the other surface side with respect to the inner hook (FIG. 7A).
The moving knife 111 operates on the upper yarns U1, U2 and the lower yarn D arranged as described above, and rotates in the forward movement direction (clockwise direction in FIG. 7). The upper yarns U1 and U2 and the lower yarn D are selected by the pointed portion 111c directed to the side, and only the upper yarn U1 is captured by the concave portion 111a and transported in the forward movement direction (FIG. 7B). Further, the moving knife 111 carries the upper thread U1 to the thread picker 112, and locks the upper thread U1 to the thread picker 112 (FIG. 7C).
Thereafter, the state in which the inner shuttle passes through the upper thread loop is completed, the moving direction of the moving knife 111 is switched in the backward movement direction, and the upper thread U2 and the lower thread are moved by the concave portion 111b provided in the backward movement direction of the moving knife 111. D is captured (FIG. 8A). At this point, the upper thread is released from the tension applied state by the thread tension, and the lower thread is in a low tension state from the beginning.
Then, the upper thread U2 and the lower thread D are sandwiched between the fixed knife 113 and the moving knife 111 provided at the destination in the backward movement direction, and these are cut (FIG. 8B).
In FIGS. 7 and 8, the interval between the upper threads U1 and U2 is shown apart from the actual one for clarity of explanation, but these are actually Closer.
[0005]
[Patent Document 1]
JP-A-10-258196 (FIG. 5)
[0006]
[Problems to be solved by the invention]
However, in the above-mentioned conventional example, when the upstream portion U1 of the upper thread is selected by the moving knife 111 of the thread cutting device 110, the upper thread is removed depending on the hole width of the needle hole 102 located above the thread cutting device 110. In some cases, U1 could not be selected because of the swing in the hole width direction and the position was not stable, or the U1 could not be engaged with the thread pulling member 112 because it fell off the forward-direction recessed portion 111a of the moving knife 111.
The thread take-up member 112 is provided to increase the length of the upper thread remaining on the sewing needle 101 after cutting, and when the upper thread is not locked, the remaining length of the sewing needle 101 becomes extremely short. Then, at the time of the next sewing, the upper thread is detached from the sewing needle, and a sewing error is likely to occur.
[0007]
In order to prevent this, a method of arranging the thread pulling member 112 closer to the needle drop position O or forming the depth d of the concave portion 111a provided on the forward movement direction side of the moving knife 111 is considered. However, in the former case, there is a problem that the remaining length of the upper thread of the sewing needle 101 is shortened after all.
[0008]
In the latter case, the moving knife 111 has to be additionally rotated in the forward direction by the depth d of the concave portion 111a. There is a problem that the size of the H.110 increases.
The thread cutting device 110 has a function of selecting only the upper thread U1 from the upper thread U1, U2, and the lower thread D arranged along the axial direction of the shuttle shaft of the shuttle mechanism (hereinafter, referred to as the shuttle shaft direction). The turning direction of the moving knife 111 needs to be along the direction orthogonal to the hook shaft direction. On the other hand, the hook mechanism is generally branched from the drive motor of the sewing needle 101 and is supplied with power. Often along the length of the bed.
In this case, if the thread cutting device is enlarged in the rotation direction of the moving knife, the sewing machine bed is enlarged in a direction (width direction) orthogonal to the longitudinal direction. In such a case, in the case of a sewing machine having a small width of the sewing machine bed, such as a cylinder bed sewing machine having a small-diameter cylindrical tip at the tip of the sewing machine bed, in particular, it is not possible to adopt a method of making the concave portion of the moving knife deep. However, the thread end length remaining on the sewing needle could not be sufficiently secured. Therefore, the problem that the upper thread comes off from the sewing needle after cutting cannot be solved.
[0009]
Further, another problem of the conventional example will be described with reference to FIG. FIG. 10 is an explanatory view of the state of FIG. 8B as viewed from a direction along the shuttle shaft. Although the above-described operation explanatory diagrams 7 and 8 show the vertical intervals of each component widely for the sake of simplicity of illustration, actually, as shown in FIG. 10, each component is arranged close to each other. .
According to FIG. 10, the upper thread U is remarkably bent everywhere with respect to each configuration, and as a result, sliding friction is generated everywhere and the upper thread cannot be sufficiently pulled out from the supply side of the upper thread. There has been an inconvenience that the remaining length of the upper thread in the later sewing needle 101 cannot be sufficiently secured.
[0010]
In addition, the boundary between the lower surface of the needle plate and the inner surface of the needle hole has not been sufficiently reduced in friction because it is not suitable for the sewing finish because it is inappropriate to make a curved surface having a large radius of curvature. The upper thread locked by the bobbin member receives a high frictional force at the lower end portion of the inner surface of the needle hole, causing a disadvantage that the remaining length of the upper thread in the sewing needle 101 after cutting cannot be sufficiently secured. Was.
[0011]
An object of the present invention is to ensure a sufficient remaining length of the upper thread in the sewing needle after cutting the upper thread by the thread cutting device and to surely perform the thread cutting.
It is another object of the present invention to prevent the size of the thread cutting device from increasing while securing the remaining length of the upper thread of the sewing needle.
[0012]
[Means for Solving the Problems]
The invention according to claim 1 includes a thread cutting device that cuts an upper thread and a lower thread, a shuttle mechanism provided below the thread cutting device and that allows the lower thread to pass through a loop formed by the upper thread. The cutting device sorts the upper thread that is upstream with respect to the shuttle mechanism by forward movement of the reciprocating rotation along a substantially horizontal direction, and cuts the upper thread that is downstream with respect to the shuttle mechanism by backward movement. A needle plate provided on the upper surface of a sewing machine bed of a sewing machine including a moving knife transported to the moving knife and a thread take-up member that locks an upper thread selected upstream of the moving knife, the needle into which a sewing needle is inserted. In addition to the hole, the lower surface is provided with a thread guide groove having a width smaller than that of the needle hole so as to extend substantially in the same direction from the forward end of the moving knife of the needle hole in the same direction. I am taking it.
[0013]
In the above description, “forward movement” refers to a reciprocating rotating knife in one direction, and “reverse” refers to a reciprocating rotating knife in the other direction. Say.
In the above configuration, when the sewing needle is positioned below the needle hole, the shuttle mechanism catches the upper thread and forms a loop. When the upper thread is engaged with the shuttle mechanism, the upper thread upstream and the lower thread downstream of the shuttle mechanism are arranged above the shuttle mechanism. On the other hand, the moving knife of the thread cutting device selects and captures only the upper thread that is on the upstream side with respect to the shuttle by the forward movement, and transports it to the thread picking member.
[0014]
At this time, the upper thread on the upstream side is inclined from the state along the vertical direction toward the forward movement direction of the moving knife, and at the portion that contacts the needle hole, the forward movement is performed at the end of the needle hole on the forward movement direction side. The yarn enters the yarn guide groove formed in the direction.
The thread guide groove may be at least narrower than the width of the needle hole in the same direction. For example, the thread guide groove is desirably as narrow as possible so that the thread can enter and the thread can slide along the groove. .
Then, since the upper thread is transported to the thread pulling member in the state of having entered the thread guide groove in this manner, the occurrence of a state in which the upper thread swings to both sides within the width of the needle hole is effectively suppressed. Further, the state in which the upper thread has entered the thread guide groove is maintained until the cutting is completed, so that the run-up of the upper thread is suppressed continuously even after the state in which the upper thread is locked by the thread pulling member.
For this reason, accidental detachment of the upper thread from the moving knife is effectively suppressed, and the remaining length of the upper thread after cutting at the sewing needle is properly secured.
[0015]
Further, when the upper thread enters the thread guide groove, the inclination angle of the upper thread from the needle hole to the thread pulling member and the degree of bending of the angle formed by the upper thread before and after the thread pulling member are reduced, and the moving knife moves. , The operation of pulling out the upper thread is smoothly performed. Therefore, the upper thread is smoothly fed by the movement of the moving knife, and the remaining length of the upper thread after cutting at the sewing needle is properly secured.
[0016]
A second aspect of the present invention has the same configuration as the first aspect of the present invention, and connects the inner surface of the needle hole and the boundary between the lower surface of the needle plate with a curved surface, and connects the inner surface of the needle hole with the inner surface of the needle hole. The boundary between the thread guide groove and the bottom surface is connected by a curved surface, and the radius of curvature of the curved surface between the inner surface of the needle hole and the bottom surface of the thread guide groove is larger than the curved surface between the inner surface of the needle hole and the lower surface of the needle plate. Is made larger.
[0017]
In the above configuration, the same effect as the first aspect of the invention is achieved, and in a state where the upper thread is locked by the thread take-up member, the upper thread enters the thread guide groove. It does not touch the boundary with the lower surface, but comes into contact with the curved surface provided at the boundary between the inner surface of the needle hole having a larger radius of curvature and the bottom of the thread guide groove. The feeding operation is performed smoothly. Therefore, the upper thread is smoothly fed by the movement of the moving knife, and the remaining length of the upper thread after cutting at the sewing needle is properly secured.
In such a case, since the thread guide groove is not arranged so that the upper thread enters during normal sewing, there is no influence on sewing by providing the curved surface having a large radius of curvature as described above.
[0018]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of the present invention will be described with reference to FIGS. FIG. 2 is a perspective view of the cylinder bed sewing machine 10 according to the embodiment of the present invention. The cylinder bed sewing machine 10 includes a sewing machine bed 11 located at a lower portion thereof, a sewing machine body 12 raised from one end of the sewing machine bed 11, and a cylinder bed sewing machine 10 from above the sewing machine body 12. And a sewing machine arm 13 extending along the sewing machine bed 11.
The machine bed 11 is provided with a substantially cylindrical cylinder-shaped portion 14 extending along the longitudinal direction of the machine bed 11 at an end opposite to the machine body 12.
In describing the configuration of the sewing machine 10, a vertical movement direction of a sewing needle 15 described later is defined as a Z-axis direction, and a direction orthogonal to the Z-axis direction and a longitudinal direction of the sewing machine bed 11 and the sewing machine arm 13 is defined as a Y-axis direction. A direction orthogonal to both the Z-axis direction and the Y-axis direction is defined as an X-axis direction.
[0019]
The cylinder bed sewing machine 10 is provided at the distal end of the sewing machine arm 13 and is provided with a sewing needle 15 that is reciprocated in a vertical direction by a sewing machine motor (not shown). An upper thread supply source (not shown) for supplying the upper thread with a predetermined load between the upper thread supply source and the sewing needle 15 to generate a desired resistance to the movement in the feed direction. A balance device for lifting the upper thread by a balance 17 at a predetermined timing between the thread tension device 16 and the sewing needle 15; and a sewing needle provided on the upper surface of the cylinder-shaped portion 14 of the sewing machine bed 11. A needle plate 20 provided with a needle hole 21 through which the distal end of the needle 15 is inserted; a thread cutting device 110 provided in the cylinder-shaped portion 14 below the needle plate 20 to cut the upper thread and the lower thread; , Thread cutting device Provided below, and a shuttle mechanism 103 for inserting the lower thread in a loop by the upper thread.
[0020]
(Hook mechanism)
FIG. 3 is a schematic configuration diagram of the configuration located below the needle plate 20 as viewed from the Y-axis direction. Since the shuttle mechanism 103 has the same configuration as that of the conventional shuttle mechanism described above, in each of the drawings, its overall shape is shown only by a two-dot chain line, and redundant description will be omitted.
The shuttle mechanism 103 is disposed below the thread cutting device 110 in the cylinder-shaped portion 14 and has a bobbin provided therein with a bobbin serving as a lower thread supply source, and is rotatably provided on the outer periphery of the bobbin. An outer hook that captures the upper thread loop and a shuttle shaft to which the driving force of the sewing machine motor is transmitted to rotate the outer hook are provided (all components are not shown). The shuttle shaft is arranged along the Y-axis direction, and the inner shuttle and the outer shuttle are arranged at the end of the cylinder-shaped portion 14 on the same side as the tip end side.
[0021]
The inner hook pulls out the lower thread from the bobbin located inside the inner hook, while the outer hook causes the upper hook loop captured by the sword point to pass through the inner hook by rotating operation. By this operation, a state where the lower thread is inserted through the upper thread loop is formed, and the seam is formed by the subsequent lifting operation of the upper thread by the balance mechanism.
[0022]
Here, when the inner hook is passed halfway into the loop of the upper thread by the shuttle mechanism 103, the upper thread is turned back across the inner hook. A portion U1 on the upstream side (a side closer to the sewing needle 15) of the upper thread and a portion U2 on the downstream side (a side closer to the seam of the fabric) are arranged along the Y-axis direction. It will be in a lined up state. Then, the downstream upper thread U2 is located at a position closer to the tip end of the cylinder-shaped portion 14 than the upstream upper thread U1. Further, at this time, the lower thread D is also located on the tip side of the cylinder-shaped portion 14 with respect to the upper thread U1 on the upstream side (see FIG. 7A). By utilizing the state in which the upper yarns U1, U2 and the lower yarn D are arranged along the Y-axis direction in this way, the yarn cutting device 110 selects only the upper yarn U1 on the upstream side and performs other cutting. It is possible. In addition, although U1 and U2 are denoted by different symbols for the upper thread, they are connected at the lower part of the shuttle mechanism 103.
[0023]
(Thread cutting device)
The thread trimming device 110 shown in FIGS. 4 and 9 has the same configuration as that of the above-described conventional thread trimming device, and a duplicate description will be omitted.
The thread cutting device 110 is arranged in the cylinder shape portion 14 in the order of the thread picking member 112, the moving knife 111, and the fixed knife 113 along the X-axis direction. The moving knife 111 has a function of selecting the upper thread U1 from the upper thread U1, U2 and the lower thread D arranged in the Y-axis direction by the above-described shuttle mechanism. To rotate. Further, the moving knife 111 is arranged such that its rotating end is on the distal end side of the cylinder-shaped portion 14 and its base end (the rotating center side) is on the sewing machine body 12 side.
[0024]
The concave portion 111a for catching the upper thread U1 of the moving knife 111 is formed at a position slightly closer to the rotation center from the rotating end in the rotating radial direction on the forward movement direction F side of the moving knife 111, and The concave portion 111b for catching the thread U2 and the bobbin thread D is located at the rotation end on the forward movement direction B side of the moving knife 111. This makes it possible to select only the upper thread U1 closest to the rotation center of the moving knife 111 from the upper thread U1, U2 and the lower thread D arranged in the Y-axis direction by rotating in the forward direction. I have.
[0025]
(Needle plate)
FIG. 1A shows a state where the main part of the needle plate 20 is viewed from the X-axis direction (left side in FIG. 3), and FIG. 1B shows the main part of the needle plate 20 in the Y-axis direction (FIG. 1A ) Shows a state viewed from the left), and FIG. 1C shows a state viewed from the Z-axis direction (upper side in FIG. 1A).
The needle plate 20 has a plate-shaped portion 21 disposed above the cylinder-shaped portion 14 along the XY plane, and a columnar portion provided on the lower surface side of the needle drop position of the sewing needle 15 in the plate-shaped portion 21. And a needle hole 23 penetrating these along the Z-axis direction.
The needle hole 23 is formed in a long hole shape along the X-axis direction when viewed from above or below. A thread guide groove 24 is formed on the lower end surface of the protrusion 22 corresponding to the lower surface of the needle plate 20 from the end of the needle hole 23 on the forward movement direction F side of the moving knife 111 in the F direction. Have been.
[0026]
The thread guide groove 24 is formed to penetrate from the inner surface of the end of the needle hole 23 on the forward movement direction F side to the side surface of the protrusion 22. When the moving knife 111 selects the upper thread U1 and pushes and guides the upper thread U1 to the thread pick-up member 112 in the thread cutting operation by the thread cutting device 110, the thread guide groove 24 allows the upper thread U1 to enter and reduces the deflection in the Y-axis direction. It is formed to prevent it.
For this reason, the width of the yarn guide groove 24 in the Y-axis direction is set to be smaller than that of the needle hole 23. It is essential that the width of the thread guide groove 24 in the Y-axis direction is at least smaller than that of the needle hole 23, and from the viewpoint of preventing the upper thread U1 from swinging in the Y-axis direction, the upper thread U1 can enter. Thus, it is desirable to set as narrow as possible within a range that does not hinder sliding inside.
[0027]
Further, at the end of the needle hole 23 in the F direction, the needle hole 23 is formed so as to be biased to one side in the Y axis direction (the left side in FIG. 1A). That is, at the time of selecting the upper thread U1 in the thread cutting device 110, the upper thread U1 is located in the same direction in the Y-axis direction among the upper threads U1, U2 and the lower thread D, and among the respective threads, By matching the arrangement of the upper thread U1 with the arrangement of the thread guide groove 24 in the needle hole 23, it is possible to smoothly guide the upper thread U1 into the thread guide groove 24.
[0028]
Further, the boundary between the bottom surface (the bottom surface as a groove, that is, the upper surface in FIGS. 1A and 1B) of the yarn guide groove 24 and the inner surface of the needle hole 23 at the end in the F direction is curved. As shown in FIG. 3, the boundary between the inner surface of the needle hole 23 and the lower end surface of the protrusion 22 is also formed in a curved shape, but the yarn guide groove 24 is larger than the radius of curvature R1 of the curved surface of the lower end of the needle hole 23. The radius of curvature R2 of the boundary curved surface between the pin hole and the needle hole 23 is set to be larger. Since the upper thread U1 slides and moves on the boundary curved surface between the thread guide groove 24 and the needle hole 23, the curvature radius R2 is desirably set to be larger. For example, the radius of curvature R1 is set to 0.3 to 0.4 [mm], and the radius of curvature R2 is set to 2 to 3 [mm].
The curved surface at the lower end portion of the needle hole 23 is set at most within the above range because setting the radius of curvature to a large value affects the finish at the time of sewing, but the thread guide groove 24 is provided with the upper thread when sewing. And since it is provided in a position which does not affect the lower thread, it is possible to set it sufficiently large.
[0029]
(Description of operation of the embodiment)
The thread cutting operation of the cylinder bed sewing machine 10 will be described. Since the thread cutting device 110 performs the same operation as that of the conventional example, it will be described based on FIGS. 3 to 5 with reference to FIGS.
First, at the end of sewing, the operation of passing the upper thread loop captured by the shuttle mechanism 103 through the intermediate shuttle of the shuttle mechanism is performed. When approximately half of the inner hook is passed through the upper thread loop, the upper thread U1, U2 and the lower thread D are arranged along the X-axis direction, and the upper thread U2 and the lower thread D rotate the moving knife 111. The upper thread U1 is disposed slightly away from the center of rotation from the center (FIG. 7A).
[0030]
In the above-described state, the moving knife 111 rotates toward the forward movement direction F, and the concave portion 111a captures only the upper thread U1 (FIG. 7B) and carries the thread to the thread pulling member 112. Thereby, the upper thread U1 is locked by the thread pulling member 112 (FIG. 7C).
In the process of being carried from the capture of the upper thread U1, as shown in FIGS. 4 and 5, the upper thread U1 enters the thread guide groove 24 from the needle hole 23 and is blocked by the side walls on both sides of the thread guide groove 24. As a result, the moving knife 111 is carried to the moving knife 111 in a state where the deflection in the Y-axis direction is prevented, so that accidental detachment of the moving knife 111 from the forward-direction-side concave portion 111a is effectively prevented.
[0031]
Thereafter, the state in which the inner hook passes under the upper thread loop is completed, the moving direction of the moving knife 111 is switched in the backward movement direction B, and the upper thread U2 and the lower thread D are captured by the concave portion 111b of the moving knife 111 (FIG. 8 (A)). At this point, the upper thread is released from the tension applied state by the thread tension, and the upper thread U2 and the lower thread D are transported to the fixed knife 113 by the moving knife 111 to be cut (FIG. 8B).
[0032]
In the process from the start of the backward movement of the moving knife 111 to the cutting, the upper thread U1 receives the tension due to the backward movement of the moving knife 111 because the upper thread U1 is locked by the thread pulling member 112, and is supplied from the yarn supply source. The upper thread is fed, and as shown in FIG. 3, the upper thread is moved downstream while sliding at the start end of the thread guide groove 24 and the thread pulling member 112.
That is, the upper thread U1 comes into contact with the curved surface formed at the boundary with the inner surface of the needle hole 23 in the thread guide groove 24, but the curved surface has a sufficiently large radius of curvature R2. Slides smoothly and does not hinder feeding from the supply source. Therefore, the remaining length of the upper thread of the sewing needle 15 after cutting is sufficiently ensured.
[0033]
As can be seen by comparing FIGS. 3 and 10, when the thread guide groove 24 is not formed (in the case of FIG. 10), the upper thread U1 is folded back from the lower end surface of the projection by the thread pulling member 112. Because the distance in the height direction from the lower end surface of the protrusion to the thread pulling member 112 is short, the angle θ2 formed by both sides of the upper thread U1 that is folded back through the thread pulling member 112 is Therefore, sliding friction easily occurs in the thread pulling member 112.
On the other hand, when the thread guide groove 24 is provided (in the case of FIG. 3), the upper thread U1 is folded back from the bottom surface of the thread guide groove 24 above the lower end of the needle hole 23 of the projection 22 by the thread pulling member 112. In this case, the distance to the fixed knife 113 is increased, so that an extra distance in the height direction to the thread pick-up member 112 can be secured by the depth of the groove. Accordingly, the angle θ1 formed between the both sides of the upper thread U1 that is folded back via the threading member 112 becomes large, and the sliding friction in the threading member 112 can be reduced.
Therefore, due to the presence of the thread guide groove 24, when the moving knife 111 is moved backward, the upper thread U1 slides smoothly, thereby achieving a good payout from the supply source. The remaining length is more sufficiently secured.
[0034]
(Effects of the embodiment)
As described above, in the cylinder bed sewing machine 10, the thread guide groove 24 is provided in the needle hole 23 of the needle plate 20, so that the upper thread U1 can move without falling off when performing the thread cutting operation. Since the scalpel 111 is satisfactorily transported to the thread pulling member 112, the remaining length of the upper thread after cutting with the sewing needle 15 can be sufficiently secured with high reliability. Thereby, it is possible to effectively suppress the occurrence of sewing errors due to the needle thread coming off at the time of next sewing, and the reliability of the cylinder bed sewing machine 10 is also improved.
[0035]
Further, it is not necessary to form the concave portion 111a of the moving knife 111 deep in order to prevent the upper thread U1 from dropping from the moving knife 111, and it is possible to avoid an increase in the width of the thread cutting device 110 in the X-axis direction. It becomes. For this reason, even if the thread cutting device 110 is arranged at a place where the width in the X-axis direction is narrow like the cylinder-shaped portion 14 of the cylinder bed sewing machine 10, the upper thread U1 from the moving knife 111 is effectively prevented from falling off, In particular, it is possible to improve the reliability.
[0036]
Further, if the effect of preventing the upper thread U1 from falling off due to the thread guide groove 24 is more remarkable, the recess 111a of the moving knife 111 can be made shallower, and thus the X-axis width of the thread cutting device 110 can be reduced. Further, the cylinder-shaped portion 14 can be further narrowed.
[0037]
(Other)
The needle plate 20 is provided with the protrusion 22 and the yarn guide groove 24 is formed on the lower end surface thereof, but it goes without saying that the protrusion 24 may not be provided. FIG. 6 is a diagram showing an example in which a needle hole 23A and a thread guide groove 24A are provided for a needle plate 20A consisting of only a plate-like portion 21A, and FIG. 6 (A) shows the needle plate 20A in the same manner as FIG. 1 (A). FIG. 6B shows a state where the main part of the needle plate 20A is viewed from the Y-axis direction (left side in FIG. 6A), and FIG. 6C shows a state where it is viewed from the X-axis direction. 7 shows a state viewed from the direction (upper side in FIG. 6A).
[0038]
The needle plate 20A is disposed on the cylinder-shaped portion of the cylinder bed sewing machine 10 like the needle plate 20, and the shape, direction, and width of the needle hole 23A are the same as those of the above-described needle hole 23. The orientation, arrangement, width and function of the thread guide groove 24A and the curvature of the boundary curved surface between the bottom surface and the inner surface of the needle hole 23A are the same as those of the thread guide groove 24.
The difference is that the exit of the thread guide groove 24 is provided on the side surface of the protruding portion 22, whereas the thread guide groove 24A is provided on the lower surface of the plate-like portion 21A. It does not affect its function.
The needle plate 20A also performs exactly the same operation as the above-described needle plate 20, and can obtain the same effect.
[0039]
【The invention's effect】
According to the first aspect of the invention, since the thread guide groove is provided in the needle hole, it is possible to prevent the yarn from swaying when the upper thread is carried to the thread pulling member by the moving knife of the thread cutting device. This prevents accidental detachment of the upper thread from the moving knife, and makes it possible to steadily lock the upper thread to the thread pulling member. Therefore, it is possible to secure a sufficient remaining length of the upper thread after the sewing needle is cut and to reliably perform the thread cutting with high reliability. Furthermore, this makes it possible to effectively suppress the occurrence of sewing errors due to the needle thread coming off during the next sewing.
[0040]
Also, there is no need to provide a deep recess on the forward movement direction side of the moving knife, and it is not necessary to extend the reciprocating stroke length of the moving knife, and it is possible to shorten the reciprocating stroke length. This can be prevented and further downsizing can be achieved.
[0041]
Furthermore, since it is possible to prevent the thread trimming device from being enlarged and to further reduce the size thereof, it is possible to prevent the width of the sewing machine bed from being increased and to further reduce the size when installing the device on the sewing machine bed. It becomes. For this reason, in the cylinder bed sewing machine in which it is necessary to reduce the width of the sewing machine bed, it is difficult to prevent the needle thread from detaching from the sewing needle. However, the present invention can effectively suppress this. This makes it possible to further reduce the width of the sewing machine bed.
[0042]
Further, by providing the thread guide groove, when the upper thread enters, the inclination angle of the upper thread passing from the needle hole to the thread pulling member and the degree of bending of the angle formed by the upper thread before and after the thread pulling member are reduced. As a result, the sliding frictional force at the bent portion can be reduced, and the operation of feeding the upper thread by moving the moving knife can be performed smoothly. Therefore, the upper thread is smoothly fed by the movement of the moving knife, and the remaining length of the upper thread after cutting at the sewing needle can be appropriately secured.
[0043]
According to the second aspect of the present invention, since a curved surface having a larger radius of curvature than other portions is formed at the boundary between the inner surface of the needle hole and the bottom surface of the yarn guide groove, the radius of curvature is increased when the upper thread enters the yarn guide groove. In contact with a large curved surface. Therefore, it becomes possible to smoothly perform the upper thread feeding operation by moving the moving knife, the upper thread is smoothly fed by moving the moving knife, and the remaining length of the upper thread after cutting at the sewing needle is properly adjusted. It is possible to secure.
[Brief description of the drawings]
FIG. 1A shows a state where a main part of a needle plate mounted on a cylinder bed sewing machine according to an embodiment of the present invention is viewed from an X-axis direction, and FIG. 1B is a view seen from a Y-axis direction. FIG. 1C shows a state viewed from the Z-axis direction.
FIG. 2 is a perspective view of the cylinder bed sewing machine according to the embodiment of the present invention.
FIG. 3 is a schematic configuration diagram of a configuration located below a needle plate as viewed from a Y-axis direction.
FIG. 4 is an explanatory view of a main part of the thread cutting device and a thread guide groove as viewed from above in order to show a relationship between the thread guide groove and the thread guide groove.
FIG. 5 is an explanatory view showing the relationship between the main part of the thread cutting device and the thread guide groove as viewed obliquely from the perspective view.
6A shows a state of another example of the needle plate viewed from the X-axis direction, FIG. 6B shows a state viewed from the Y-axis direction, and FIG. This shows a state viewed from the axial direction.
FIG. 7 is an explanatory diagram of the operation of the conventional example, and shows each step which proceeds in the order of FIGS. 7 (A) to 7 (C).
8 is an explanatory view of the operation of the conventional example following the step of FIG. 7, and shows each step which proceeds in the order of FIGS. 8 (A) and 8 (B).
FIG. 9 is a plan view showing a conventional thread cutting device.
FIG. 10 is a schematic configuration diagram of a configuration located below a needle plate in a conventional example, viewed from a hook shaft direction.
[Explanation of symbols]
10 Cylinder bed sewing machine
11 sewing machine bed
14 Cylinder shape
20 Needle plate
23 Needle hole
24 thread guide groove
103 Hook mechanism
110 Thread trimmer
111 moving knife
112 Thread picking member

Claims (2)

上糸の切断を行う糸切り装置と、前記糸切り装置の下方に設けられ,前記上糸によるループに前記下糸を挿通させる釜機構と、を備えると共に、前記糸切り装置は、略水平方向に沿った往復回動動作の往動により前記釜機構に対して上流側となる上糸を選別し,復動により前記釜機構に対して下流側となる上糸を切断位置に運ぶ動メスと、当該動メスに選別された前記上流側となる上糸を係止する糸たぐり部材とを備えるミシンのミシンベッド上面に設けられる針板であって、
縫い針が挿入される針穴を備えると共に、その下方側となる面に、前記針穴の前記動メスの往動方向側の端部から同方向にほぼ沿うように前記針穴よりも幅が狭い糸案内溝を設けたことを特徴とするミシンの針板。
A thread cutting device for cutting the upper thread, and a shuttle mechanism provided below the thread cutting device for passing the lower thread through a loop formed by the upper thread, and the thread cutting device is provided in a substantially horizontal direction. A moving knife that selects an upper thread upstream with respect to the shuttle mechanism by forward movement of a reciprocating rotation operation along with and moves the upper thread downstream with respect to the shuttle mechanism to a cutting position by backward movement; A needle plate provided on a sewing machine bed upper surface of a sewing machine including a thread take-up member that locks the upper thread selected as the moving knife on the upstream side,
A needle hole into which a sewing needle is inserted is provided, and the width of the needle hole is smaller than the width of the needle hole so that the lower surface of the needle hole extends substantially in the same direction from the forward end of the moving knife in the forward direction. A needle plate for a sewing machine, wherein a narrow thread guide groove is provided.
前記針穴の内面と前記針板の下方側となる面との境界とを曲面で連ねると共に,前記針穴の内面と前記糸案内溝の底面との境界を曲面で連ね、
前記針穴の内面と前記針板の下方側となる面と間の曲面よりも,前記針穴の内面と前記糸案内溝の底面と間の曲面の曲率半径を大きくしたことを特徴とする請求項1記載のミシンの針板。
A curved surface connects the inner surface of the needle hole and a boundary between the lower surface of the needle plate, and a curved surface connects the inner surface of the needle hole and the bottom surface of the thread guide groove.
A radius of curvature of a curved surface between the inner surface of the needle hole and the bottom surface of the thread guide groove is larger than a curved surface between an inner surface of the needle hole and a surface below the needle plate. Item 7. A needle plate of the sewing machine according to Item 1.
JP2003009288A 2003-01-17 2003-01-17 Sewing machine needle plate Expired - Fee Related JP4253192B2 (en)

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JP4707489B2 (en) * 2005-07-27 2011-06-22 Juki株式会社 Sewing hook mechanism
KR20100007205A (en) * 2008-07-11 2010-01-22 썬스타 특수정밀 주식회사 A needle plate of embroidery machine
CN101845724B (en) * 2009-03-27 2013-03-06 兄弟工业株式会社 Sewing machine
CN203360807U (en) * 2012-09-06 2013-12-25 飞马缝纫机制造株式会社 Needle cylinder machine base sewing machine

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