JPS60192650A - Printhead - Google Patents

Abstract

PURPOSE:To lower noise to the extent of a vibration sound of a plate spring eliminating an impact member by mounting a permanent magnet piece to a plate spring retaining a wire to form a magnetic path in combination with a yoke and a core arranged contactlessly of an electromagnetic unit. CONSTITUTION:In an electromagnetic unit 6, a yoke 8 and a core arranged parallel along the direction of moving a wire 2 are integrated on a yoke base section 8a in the shape of roughly U viewed from the side and a coil 10 is wound on the core 9. When printing, a DC printing pulse is applied to the coil 10 so that a core head 11 will turn to an N pole and hence, the tip of the yoke 8 turns to the S pole. As a result, a magnetic flux with a permanent magnet piece 13 is cancelled during the non-energization time and energy accumulated in a plate spring 3 with the deflection thereof to the electromagnetic unit 6 during the non-energization time is released while a reaction acts on the permanent magnet piece 13 with the N pole of the core head 11 and the S pole of the yoke 8 and the plate spring 3 deflects elastically in the direction of printing. Thus, a printing action is done with the wire 2 retained on the plate spring 3.

Description

【発明の詳細な説明】 発明の技術分野 本発明は、ワイヤを往復動させて印字を行なわせるワイ
ヤドツト方式等の印字ヘッドに関する。DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to a print head such as a wire dot type print head that performs printing by reciprocating a wire.

発明の技術的背景及びその問題点 従来、この種の印字ヘッドにあっては、複数本のワイヤ
を縦−列又は千鳥状縦二列に配列し、電磁駆動によりワ
イヤを往復動させるのが一般的である。このような印字
ヘッドがキャリアに搭載されて桁走査を逐次骨なって印
字することになる。Technical Background of the Invention and Problems Thereto Conventionally, in this type of print head, a plurality of wires are generally arranged in a vertical row or in two vertical rows in a staggered pattern, and the wires are moved back and forth by electromagnetic drive. It is true. Such a print head is mounted on a carrier and sequentially prints by scanning the digits.

具体的なヘッド構造としては、特開昭５５−６１４８５
号公報等に示されるものがある。このような電磁駆動方
式は、ワイヤをアーマチュア又は板ばねに取付け、電磁
装置のヨークとコアとともに永久磁石によって磁路を形
成し、電磁装置の非通電時には永久磁石による磁路でア
ーマチュア又は板ばねをコアに密着させておき、印字時
には電磁装置に通電して永久磁石による磁束を打消すこ
とによりアーマチュア又は板ばねを印字方向へ解放させ
て印字を行なうものである。つまり、磁気回路効率を高
めるため、アーマチュアや板ばねをコアに完全密着させ
ているので、印字後の復帰時に両者が衝突し、大きな騒
音を生ずることになる。The specific head structure is disclosed in Japanese Patent Application Laid-Open No. 55-61485.
There are some that are shown in the No. 1 gazette, etc. In this type of electromagnetic drive system, a wire is attached to an armature or a leaf spring, and a permanent magnet forms a magnetic path together with the yoke and core of the electromagnetic device.When the electromagnetic device is not energized, the permanent magnet drives the armature or leaf spring. It is placed in close contact with the core, and when printing, an electromagnetic device is energized to cancel the magnetic flux caused by the permanent magnet, thereby releasing the armature or leaf spring in the printing direction to perform printing. In other words, in order to improve the efficiency of the magnetic circuit, the armature and leaf spring are brought into close contact with the core, so that when the printer returns after printing, the two collide with each other, producing a large amount of noise.

発明の目的 本発明は、このような点に鑑みなされたもので、電磁駆
動方式を採用しつつ衝突音をな≦して低騒音化すること
ができる印字ヘットを得ることを目的とする。OBJECTS OF THE INVENTION The present invention has been made in view of the above points, and an object of the present invention is to provide a print head that employs an electromagnetic drive system and can reduce collision noise by reducing noise.

発明の概要 本発明は、基本的には電磁装置の通電・非通電によりワ
イヤを駆動させるものであり、ワイヤを保持した板ばね
に永久磁石片を取付けるが、電磁装置のヨーク及びコア
と非接触で永久磁石片とこれらとで磁路を形成すること
により、衝突部材がなく、騒音は板ばねの振動音程度に
低減化することができるように構成したものである。Summary of the Invention The present invention basically drives a wire by energizing or de-energizing an electromagnetic device, and a permanent magnet piece is attached to a leaf spring holding the wire, but it does not make contact with the yoke and core of the electromagnetic device. By forming a magnetic path with these and the permanent magnet pieces, there is no collision member and the noise can be reduced to the level of the vibration sound of a leaf spring.

発明の実施例 本発明の一実施例を図面に基づいて説明する。Examples of the invention An embodiment of the present invention will be described based on the drawings.

まず、ポリエチレンサルファイド等により円形に形成さ
れたベース１の外周には台座部１ａが射出成形されてい
る。そして、複数本のワイヤ２が設けられている訳であ
るが、各ワイ・ｖ２の後端は板ばね３の先端に固定され
ている。各板ばね３の他端は台座部１ａに対し押え板４
、固定ねじ５により固定されている。従って、板ばね３
はワイヤ２の移動方向にバネ性を示すことになる。ここ
で、板ばね３は印字速度との関係から、できるだけ高い
共振周波数が得られるように二等辺三角形の形状とされ
ている。又、板ばね３の固定部分であるが、押え板４上
端よりも台座部１ａの方が突出して段差ａがつけられて
いる。つまり、板ばね３のバネ性を示す長さは印字方向
への撓み時には（Ｑ＋ａ）であるが、復帰方向への撓み
時にはこれより短くＱだけとなるように設定し、印字方
向側へより撓み易くしたものである。First, a pedestal portion 1a is injection molded on the outer periphery of a circular base 1 made of polyethylene sulfide or the like. Although a plurality of wires 2 are provided, the rear end of each wire v2 is fixed to the tip of the leaf spring 3. The other end of each leaf spring 3 is attached to a holding plate 4 against the base portion 1a.
, are fixed by fixing screws 5. Therefore, leaf spring 3
exhibits springiness in the direction of movement of the wire 2. Here, the leaf spring 3 has an isosceles triangular shape in order to obtain as high a resonance frequency as possible in view of the printing speed. Furthermore, regarding the fixed portion of the leaf spring 3, the pedestal portion 1a protrudes more than the upper end of the presser plate 4, and is provided with a step a. In other words, the length indicating the springiness of the leaf spring 3 is (Q + a) when it is deflected in the printing direction, but it is set to be shorter than this and only Q when it is deflected in the return direction, so that it is deflected more towards the printing direction. It is made easier.

しかして、板ばね３の背部側には台座部１ａより内周側
に位置させて電磁装置６がベース１にねじ７により取付
けられている。この電磁装置６は前記ワイヤ２の移動方
向に沿って平行に配列されたヨーク８とコア９とをヨー
ク基部８ａで一体化して側面的に略コ字状とし、コア９
にコイル１０を巻回してなる。ここで、コア９の先端に
はコアヘッド１１が固定されている。これらのヨーク８
゜コア９、コアヘット１１は精密鋳造され、材質的には
３％珪素入りの軽質磁性材が用いられる。このようにし
てヨーク８先端部とコアヘッド１１との間に寸法ｄなる
隙間１２が確保されている。On the back side of the leaf spring 3, an electromagnetic device 6 is attached to the base 1 with screws 7 so as to be located on the inner peripheral side of the pedestal portion 1a. This electromagnetic device 6 has a yoke 8 and a core 9 arranged in parallel along the moving direction of the wire 2, which are integrated at a yoke base 8a to form a substantially U-shaped side surface.
A coil 10 is wound around the coil 10. Here, a core head 11 is fixed to the tip of the core 9. These yokes 8
The core 9 and core head 11 are precision cast and made of a light magnetic material containing 3% silicon. In this way, a gap 12 having a size d is secured between the tip of the yoke 8 and the core head 11.

一方、前記板はね３の先端背面には直方形状の永久磁石
片１３が前記ワイヤ２とともにエポキシ樹脂等の接着剤
により固定されている。この永久磁石片１３は電磁装置
６の隙間１２部分に対向するものであるが、永久磁石片
１３がこの隙間１２に対し上下均等な隙間δ１が確保さ
れ非接触となるようにセットされる。ここで、永久磁石
片１３の極性はワイヤ２の移動方向に直交する方向とさ
れ、コアヘッド１１側がＮ極とされて（Ａる。On the other hand, a rectangular permanent magnet piece 13 is fixed to the rear surface of the tip of the plate blade 3 together with the wire 2 using an adhesive such as epoxy resin. This permanent magnet piece 13 is opposed to the gap 12 portion of the electromagnetic device 6, and is set so that an equal gap δ1 above and below the gap 12 is ensured and there is no contact between the permanent magnet piece 13 and the gap 12 of the electromagnetic device 6. Here, the polarity of the permanent magnet piece 13 is set in a direction perpendicular to the moving direction of the wire 2, and the core head 11 side is set as the north pole (A).

このような構成において、コイル１０７＼の非通電時に
は、永久磁石片１３がその残留磁束ｋｎよって第３図に
示すように隙間１２に入り込んでコアへット１１の中心
線φ−φ上に位置して安定する。In such a configuration, when the coil 107\ is not energized, the permanent magnet piece 13 enters the gap 12 due to its residual magnetic flux kn, as shown in FIG. 3, and is positioned on the center line φ-φ of the core head 11. and stabilize.

これにより、永久磁石片１３を保持した板ばね３が電磁
装置６側へ撓むことになるが、コア９と板ばね３との間
に隙間δ２が確保されており、両者が接触することはな
い。このようにして、永久磁石片１３−ヨーク８−コア
９−コアヘッド１１−永久磁石片１３の方向に閉じた磁
路Ｐが形成され７、− しかして、印字時にはコアヘッド１１がＮ極となるよう
に直流印字パルスをコイル１０に通電する。これにより
、ヨーク８先端はＳ極となる。この結果、非通電時にお
ける永久磁石片１３による磁束を打消すことになる。そ
こで、非通電時に電磁装置６側ｌ＼の撓みにより板ばね
３に蓄えられていたエネルギーが解放され、同時に、永
久磁石片１３に対しコアヘッド１１のＮ極、ヨーク８の
Ｓ極により反発力が作用し、板ばね３が弾発的に印字方
向へ撓み、この板ばね３により保持されたワイヤ２によ
って印字動作が行なわれる。As a result, the leaf spring 3 holding the permanent magnet piece 13 is bent toward the electromagnetic device 6, but a gap δ2 is secured between the core 9 and the leaf spring 3, so that the two do not come into contact. do not have. In this way, a magnetic path P closed in the direction of the permanent magnet piece 13 - yoke 8 - core 9 - core head 11 - permanent magnet piece 13 is formed 7, so that the core head 11 becomes the north pole during printing. Then, a DC printing pulse is applied to the coil 10. As a result, the tip of the yoke 8 becomes the S pole. As a result, the magnetic flux caused by the permanent magnet piece 13 when the current is not applied is canceled. Therefore, the energy stored in the leaf spring 3 is released due to the bending of the electromagnetic device 6 side l\ when the current is not applied, and at the same time, a repulsive force is generated against the permanent magnet piece 13 by the N pole of the core head 11 and the S pole of the yoke 8. As a result, the leaf spring 3 elastically bends in the printing direction, and the wire 2 held by the leaf spring 3 performs a printing operation.

そして、印字後には板ばね３の弾性力により元位置側へ
戻る。この時１段差ａにより板ばね３は直立点を越える
とバネの強さが強くなるので制動され、板ばね３の固有
振動は抑制される。After printing, the sheet returns to its original position due to the elastic force of the leaf spring 3. At this time, when the leaf spring 3 exceeds the upright point due to the one step difference a, the strength of the spring becomes stronger and is therefore braked, and the natural vibration of the leaf spring 3 is suppressed.

いずれにしても、本実施例によれば、板ばね３′や永久
磁石片１３がヨーク８やコア９に衝突することがなく、
板ばね３の振動音程度の騒音に抑えることができる。In any case, according to this embodiment, the leaf spring 3' and the permanent magnet piece 13 will not collide with the yoke 8 and the core 9, and
The noise can be suppressed to the same level as the vibration sound of the leaf spring 3.

発明の効果 本発明は、上述したようにワイヤを板ばねにより保持さ
せ、ワイヤ移動方向に沿って平行に配列されたヨークと
コアとを備えた電磁装置を設け、ワイヤ移動方向に直交
する方向に極性を持ちヨーク及びコアと非接触でこれら
とともに磁路を形成する永久磁石片を板ばねに取付けた
ので、非通電時には永久磁石片−ヨーク−コアで閉磁路
が形成され板はわが撓んだ状態で安定し、印字通電時に
は逆の磁束を生じさせることにより、板ばねの歪エネル
ギーと反発磁界とによって印字動作が行なわれることに
なり、これらの動作において衝突する部材がなく、騒音
を板ばねの振動音程度に抑えることができ、静粛な印字
を行なわせることができるものである。Effects of the Invention As described above, the present invention includes an electromagnetic device in which the wire is held by a plate spring, and includes a yoke and a core arranged in parallel along the direction of wire movement. A permanent magnet piece that has polarity and forms a magnetic path with the yoke and core without contacting them is attached to the leaf spring, so when the current is not energized, a closed magnetic path is formed between the permanent magnet piece, yoke, and core, and the plate bends. By creating a reverse magnetic flux when electricity is applied for printing, the printing operation is performed by the strain energy of the leaf spring and the repulsive magnetic field, and there are no members that collide during these operations, and the noise is reduced by the leaf spring. It is possible to suppress the vibration noise to about the same level as that of the printer, and it is possible to perform quiet printing.

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

図面は本発明の一実施例を示すもので、第１図は正面図
、第２図はその縦断側面図、第３図は非通電時の縦断側
面図である。 ２・・・ワイヤ、３・・・板ばね、６・・・電磁装置、
８・・・ヨーク、９・・・コア、１３・・・永久磁石片
３コ　図The drawings show one embodiment of the present invention, and FIG. 1 is a front view, FIG. 2 is a vertical side view thereof, and FIG. 3 is a vertical side view in a non-energized state. 2... Wire, 3... Leaf spring, 6... Electromagnetic device,
8...Yoke, 9...Core, 13...3 permanent magnet pieces

Claims (1)

【特許請求の範囲】[Claims] ワイヤを往復動させて印字を行なわせる印字ヘッドにお
いて、前記ワイヤの移動方向に直交する板ばねの先端に
前記ワイヤを固定するとともにこの板ばねの他端を固定
部に固定し、前記ワイヤの移動方向に沿って平行に配列
されたヨークとコアとを備えた電磁装置を設け、前記ワ
イヤの移動方向に直交する方向に極性を持ち前記ヨーク
及びコアと非接触でこれらとともに磁路を形成する永久
磁石片を前記板ばねに取付けたことを特徴とする印字ヘ
ッド。In a print head that performs printing by reciprocating a wire, the wire is fixed to the tip of a leaf spring perpendicular to the direction of movement of the wire, and the other end of the leaf spring is fixed to a fixed part, so that the movement of the wire is fixed. A permanent electromagnetic device comprising a yoke and a core arranged in parallel along a direction, having a polarity in a direction perpendicular to the direction of movement of the wire and forming a magnetic path with the yoke and the core without contacting them. A print head characterized in that a magnetic piece is attached to the leaf spring.