JPS602077B2 - Sewing machine bobbin thread tension adjustment device - Google Patents

Description

【発明の詳細な説明】 本発明はミシンの下糸張力調節装置に関するものであり
、その目的とするころは下糸関連機構をミシンに装着し
たままで電気制御によって下糸張力を調節する装置を提
供しようとするものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a bobbin thread tension adjustment device for a sewing machine, and its object is to provide a device for adjusting bobbin thread tension by electrical control while the bobbin thread related mechanism is attached to the sewing machine. This is what we are trying to provide.

ミシンにおける下糸の調節は従来中釜あるいはボビンケ
ースに取り付けた下糸張力調筋ばねのばね圧をねじなど
を用いて調節して行うものであるが、これはすべり板を
あげたり、ボビンケースを取り出して行うものであり、
作業がわずらわしく且つ縫い加減をみながら行うなど出
来なかった。Adjustment of the bobbin thread in a sewing machine is conventionally done by adjusting the spring pressure of a bobbin thread tension adjustment spring attached to the inner hook or bobbin case using a screw, but this is done by raising a sliding plate or tightening the bobbin case. This is done by taking out the
The work was tedious and it was impossible to do it while checking the stitching.

本発明は下糸張力を電磁力で調節し、その電磁力を電気
制御して操作性がよく且つ制御性の良い装置を開発した
ものである。以下本発明の詳細を図面によって説明する
と、第１〜２図において１は外釜で磁性体よりなる釜軸
２に取り付けられ、下藤３の運動がギャ４，５結合で伝
達されて回転するようになっている。The present invention has developed a device that adjusts the bobbin thread tension using electromagnetic force and electrically controls the electromagnetic force to provide good operability and controllability. The details of the present invention will be explained below with reference to the drawings. In Figs. 1 and 2, reference numeral 1 denotes an outer hook, which is attached to a hook shaft 2 made of a magnetic material, and the motion of the lower bucket 3 is transmitted through the gears 4 and 5 to rotate it. It looks like this.

６は非磁性体よりなる補助軸で前記釜鞄２と同軸的にね
じ７を用いて結合されている。Reference numeral 6 denotes an auxiliary shaft made of a non-magnetic material, which is coaxially connected to the shuttle bag 2 using a screw 7.

８はミシン本体（図示せず）と一体の軸受である。8 is a bearing integrated with the sewing machine body (not shown).

９は励磁コイルで、釜軸２と同軸に且つ該軸を回転可能
にミシン本体に取り付けられ、後記する制御回路を用い
てその励磁電流が制御される。Reference numeral 9 denotes an excitation coil, which is attached to the sewing machine body coaxially with the hook shaft 2 and rotatable about the shaft, and its excitation current is controlled using a control circuit to be described later.

１０は中釜でその主要部は合成樹脂製であるが、磁性体
よりなる中釜底１１がインサートしてある。Reference numeral 10 denotes an inner pot, the main part of which is made of synthetic resin, but an inner pot bottom 11 made of a magnetic material is inserted.

前記中釜１０は揺動式回止装橿１２によって回り止めが
なされており、前記中釜底は前記釜軸２とは若干の空隙
を有していて外釜１の回転中においても殆ど停止してい
る。１３は前記回止装置を揺動させるための偏心カムで
釜軸２に固定の非磁性体よりなる。The inner hook 10 is prevented from rotating by a swinging locking lever 12, and the bottom of the inner hook has a slight gap with the hook shaft 2, so that it hardly stops even when the outer hook 1 is rotating. are doing. Reference numeral 13 denotes an eccentric cam for swinging the rotation device, which is made of a non-magnetic material and is fixed to the hook shaft 2.

１４は磁性体よりなるボビンで下糸が巻かれている状態
を鎖線で示してある。14 is a bobbin made of a magnetic material, and the state in which the lower thread is wound thereon is shown by a chain line.

１５は下糸端である。15 is the lower thread end.

ボビンは下糸１５が引出されるにつれて中釜底１１上で
回転する。前記磁性体よりなる釜軸２、中釜底１１、ボ
ビン１４の組は励磁コイル９の中心部を貫通する磁路を
なし、その滋路はこれらの両端からは空間によって励磁
コイルの外側を通るようになっている。そして励磁コイ
ル９の励磁電流の増減はその磁束を増減し「 よって中
釜底１１とボビン１４との摩擦力はその間の磁気的吸着
力によって増減する。前記補助藤６などを非磁性体とし
たのは摺動面などの吸着をなくすためである。第３図は
励磁コイル９の制御回路図であり、１６は演算増中器で
その出力端子はトランジスター７のベースに接続され、
該トランジスタのコレク外こは電源（十Ｖ）を受けてい
る励磁コイル９が接続され、ェミッタは抵抗１８を介し
て接地され且つ前記演算増中器１６の反転入力端子（一
）に接続されている。The bobbin rotates on the inner hook bottom 11 as the bobbin thread 15 is drawn out. The hook shaft 2, the inner hook bottom 11, and the bobbin 14, which are made of magnetic material, form a magnetic path that passes through the center of the excitation coil 9, and the path passes outside the excitation coil through a space from both ends thereof. It looks like this. An increase or decrease in the excitation current of the excitation coil 9 increases or decreases the magnetic flux, and therefore, the frictional force between the inner pot bottom 11 and the bobbin 14 increases or decreases due to the magnetic attraction between them. This is to eliminate adhesion of sliding surfaces, etc. Fig. 3 is a control circuit diagram of the excitation coil 9, and 16 is an operational multiplier whose output terminal is connected to the base of the transistor 7.
An excitation coil 9 receiving a power supply (10 V) is connected to the outer collector of the transistor, and the emitter is grounded through a resistor 18 and connected to the inverting input terminal (1) of the operational multiplier 16. There is.

前記演算増中器１６の非反転端子（十）は下糸張力調節
用の可変抵抗１９と抵抗２０とで電源（十Ｖ）を分圧し
て受けている。以上の構成において可変抵抗１９を例え
ば小にしておくと演算増中器１６の出力電位は上昇し、
よって励磁コイル９の電流は増大する。そして抵抗量８
を通る電流が増大することによって演算増中器１６の反
転入力端子（一）の電位が上昇しいわゆるフィードバッ
ク効果をもたらす。励磁コイル９の電流の増大は中釜底
亀１とボビン１４間を通る磁束を増大させ両者間の吸着
力が大になり、よって両者間の摩擦力が大になってボビ
ン１４から糸を繰り出すための糸張力が増大する。以上
の如く本発明によれば「糸張力の調節のために励磁コイ
ルを用いてボビンの回転摩擦力を電気制御するものであ
るから、下糸関連機構をミシンに装着したままで且つ縫
いの途中で経の糸張力を確認しながらでも自由に調節出
来るので操作が簡単であり「適切な調節をなし得る等の
効果を有するものである。The non-inverting terminal (10) of the arithmetic multiplier 16 receives a power supply (10 V) divided by a variable resistor 19 and a resistor 20 for adjusting the lower thread tension. In the above configuration, if the variable resistor 19 is made small, for example, the output potential of the operational multiplier 16 increases,
Therefore, the current in the exciting coil 9 increases. and resistance amount 8
As the current passing through increases, the potential at the inverting input terminal (1) of the operational multiplier 16 increases, resulting in a so-called feedback effect. An increase in the current of the excitation coil 9 increases the magnetic flux passing between the inner hook bottom turtle 1 and the bobbin 14, and the attraction force between them increases.Therefore, the frictional force between them increases, and the thread is paid out from the bobbin 14. The thread tension increases. As described above, according to the present invention, since the excitation coil is used to electrically control the rotational friction force of the bobbin in order to adjust the thread tension, the bobbin thread-related mechanism can be attached to the sewing machine and can be used during sewing. It is easy to operate as it allows you to freely adjust the warp thread tension while checking the warp thread tension.

【図面の簡単な説明】[Brief explanation of drawings]

第１図は本発明の実施例を示す水平釜の釜部の斜面図、
第２図はその断面図、第３図は制御回路である。 図中２は磁性体よりなる釜軸、９は励磁コイル、１Ｑ‘
ま中釜、１１はその磁性体部、１４はボビン、１９は下
糸張力調節用の可変抵抗である。 第１図第２図 第３図FIG. 1 is a perspective view of the hook portion of a horizontal hook showing an embodiment of the present invention;
FIG. 2 is a sectional view thereof, and FIG. 3 is a control circuit. In the figure, 2 is a hook shaft made of magnetic material, 9 is an excitation coil, and 1Q'
11 is a magnetic body portion thereof, 14 is a bobbin, and 19 is a variable resistor for adjusting the tension of the bobbin thread. Figure 1 Figure 2 Figure 3

Claims (1)

【特許請求の範囲】[Claims] １ 中釜とボビン間の摩擦力によってボビンの回転を抑
制することによりミシンの下糸張力を調節する装置にお
いて、前期中釜とボビン間の摩擦力発生個所は共に磁性
体よりなり、該中釜とボビンとの摩擦面を通過する磁束
を発生させるためのミシンに固定の励磁コイルと該励磁
コイルの電流を調節可能にしている制御回路とを設けて
なるミシンの下糸張力調節装置。1. In a device that adjusts the bobbin thread tension of a sewing machine by suppressing the rotation of the bobbin using the frictional force between the inner hook and the bobbin, the frictional force generating points between the former inner hook and the bobbin are both made of magnetic material, and the inner hook A bobbin thread tension adjusting device for a sewing machine, comprising an excitation coil fixed to the sewing machine for generating magnetic flux passing through a friction surface between the bobbin and the bobbin, and a control circuit for adjusting the current of the excitation coil.