JP3747764B2 - Fluid supply apparatus and fluid supply method - Google Patents

Description

【００５０】
（１）式において、Pは圧力、μは流体の粘性係数、ｈは対向面間の隙間、ｒは半径方向位置、ｔは時間である。また右辺が、隙間が変化するときに発生するスクイーズアクション効果をもたらす項である。
【００５１】
さらに吐出ノズル入口部に液溜り部２８を設けた場合について、液溜り部の圧力、すなわちノズルの上流側圧力Pnは、流体の圧縮性を考慮して、
【００５２】
【数式２】

【００５３】
（２）式において、Qsはスクイーズ作用によって、液溜り部から排出される効果を考慮した流入量、Qnは液溜り部から吐出ノズル１９を経て大気に排出される流出量である。また、ｋは流体の体積弾性係数、Vは液溜り部２８の容積である。
【００５４】
吐出流量を求めるのに必要なノズルの上流側圧力Pnは、上記(1)(2)の方程式を連立して解くことにより求められる。
【００５５】
以下、流体の粘度：μ＝10,000cps、体積弾性係数：K＝300kg/cm²、境界部（流体絞り部２１の外周部）圧力：Pｓ＝20kg/cm²として、流体制御部２２が下記表１の条件で構成された場合について、吐出流量を求める解析をおこなった。
【００５６】
【表１】

【００５７】
上記条件下で得られる吐出流量の解析結果を図６に示す。
【００５８】
（１）解析のスタート段階（ｔ＝０）では、流量（圧力）の初期値を適当な値を仮定しているが、すみやかに一定値に収束する。０＜ｔ＜0.03秒の間は連続描画の状態にある。
【００５９】
（２）ｔ＝0.03秒でピストンが上昇を始めると、吐出流量は急速に低下し、開始から0.003sec（3msec）程度の立下り時間でたちまち吐出は遮断される。
【００６０】
（３）0.03<t<0.08秒の区間では、吐出流量はゼロである。この区間はピストンは一定の速度で上昇中である。表１から、実施例ではピストンストローク：Xst＝50μｍ、ピストン動作時間：Tp=0.05secであるため、ピストンの上昇速度：v=50μm/0.05sec=1.0mm/secである。
【００６１】
（４）t=0.08秒でピストンが停止すると、以降0.01sec程度の立ち上がり時間で連続塗布の状態にすみやかに復帰する。
【００６２】
以上の結果から、応答性の優れたアクチュエータを用いて、吐出流路の内部空間を急峻に増大させる実施例の方法により、0.01秒あるいはそれ以下のオーダーの極めて応答性の優れた流量制御ができることがわかる。
【００６３】
但し、吐出流量がゼロである時間はピストンが上昇している間だけである。この遮蔽時間は、アクチュエータの限界ストロークと上昇速度により決まる。
超磁歪素子を用いたアクチェータの場合、素子１０ｍｍの長さでほぼ１０μｍの変位が得られる。圧電素子を採用するならば、ほぼその半分の変位となる。
【００６４】
したがって図１の実施例において、表１の条件下では、たとえば、５０ｍｍの長さの超磁歪素子のロット６をもちいれば、Tp=0.05秒の間、吐出量をOFFにできる。
【００６５】
上記解析では、液溜り部２８の容積を大きく設定し、また液溜り部の流体の圧縮性を考慮しているが、非圧縮性に近い流体ならば、前述した立ちあがり・立下り時間は、アクチュエータの応答性の限界に近いところまで小さくできる。
【００６６】
ちなみに、超磁歪素子、圧電素子などの電磁歪素子の場合、通常、１０―⁴secのオーダーの応答性が得られる。
【００６７】
電磁ソレノイド等のアクチェータも適用可能であり、電磁歪素子と比べて応答性は一桁程悪くなるが、ストロークの制約（すなわち許容停止時間）は大幅に緩和される。
【００６８】
本発明の原理を直感的に理解しやすくするために、図２の流量制御部２２を図７のような電気回路モデルに置き換えてみる。
【００６９】
図７において、Psは流体絞り部２１の境界圧力、R0は流体絞り部２１の流体抵抗、Rnは吐出ノズル１９の流体抵抗、Qpはピストン細径軸１６の上昇速度とピストン面積で決まる流量源の大きさ、Qnは吐出ノズル１９を通過する流量を示す。ここで、吐出ノズル１９を通過する流量Qnは
【００７０】
【数式３】

【００７１】
Qn<0のとき、すなはち、次の条件のとき吐出は遮断される。
【００７２】
【数式４】

【００７３】
上記（４）式から、流量制御を可能にするためには、流体絞り部２１がある値以上の流体抵抗を持つことが必要ということが分かる。
【００７４】
図８に本実施例のディスペンサーの適用対象を示す。１００は塗布の対象であり、水平方向に走行するディスペンサーは、塗布対象の枠から外れた直後：t=tsで吐出流量を遮断する。さらにディスペンサーは、Uターン後、t=teで連続塗布を開始する。遮断から開始にいたる時間の間隔が、許容停止時間Tpの範囲内ならば、任意の時点で塗布開始ができる。塗布を開始するためには、図９に示すように、t=te1, t=te2などの任意の時点でピストンの上昇をストップすればよい。
【００７５】
再び連続塗布が始まれば、次に吐出流量を遮断するまでには十分な時間があるために、図１０で示すように、ピストンをゆっくりと初期の位置まで下降させればよい。式（１）のスクイーズアクションの項：dh/dtが十分に小さければ、吐出流量の変化は許容流量誤差の範囲に収めることができる。
【００７６】
さて、本発明では吐出遮断の状態でも、流路面積が減少する区間はないために、粉流体を流量制御する際の次のようなトラブルは一切発生しない。
【００７７】
▲１▼粉体の圧搾破損による流路の詰まり
▲２▼粉体破損による流体の特性変化
上記▲２▼は、たとえば回路実装の分野で、硬化を促進する材料をカプセル状に接着材に封入したとき、カプセルが機械的に破壊された場合に起こるトラブルである。本発明の実施例では、表１に示すように最も狭い区間は、スリーブの端面とその対向面の隙間：δs ＝30μｍであり、粉体の平均粒径よりも十分に大きく設定した。
【００７８】
なを連続塗布の状態で、ピストン１６の最下点における対向面との隙間（表１のXmin）を変えることにより、ピストン１６と吐出ノズル１９の平行２平面間の流体抵抗の変化を利用して、ある範囲の流量を任意に制御できる。
【００７９】
流体抵抗の変化と流量変化の関係は、時間遅れ要素を持たないために、高速アクチュエータのレスポンスで決まる極めて応答性の優れた流量制御ができる。
【００８０】
たとえば、４角平面のコーナーに沿ってラインを描画する場合、コーナー部分での塗布はディスペンサーの移動速度の関係で、一定幅のラインを描画するのは困難な場合が多い。本ディスペンサーの場合、変位センサー１５によるピストン位置検出をしながら、流量を少し増やしたい時はピストン１６を上昇させ、流量を減らしたい時はピストン１６を下降させればよい。
【００８１】
以下、本発明の第２の実施例について説明する。
【００８２】
図１１は、積層型の圧電素子をアクチェータとして用いて本発明を適用した場合を示す。
【００８３】
５０はピストン、５１はこのピストンの吐出側に形成されたピストン径大部、５２はピストンの上部に設けられたフランジ部、５３はシリンダ、５４はフランジ部とシリンダ５３の間に矜持されて設けられた積層型の圧電素子、５５は上部スリーブ、５６は上部スリーブに形成されたピストン５０を支えるための軸受部、５７はピストン５０の軸方向位置を検知するための変位センサーである。
【００８４】
５８はシリンダの吐出側に形成された吸入口、５９は吐出部、６０は吐出ノズルである。また、６１はピストン５０の外周面とシリンダの内周面で形成される流体絞り部である。６２はフランジ部５２と上部スリーブ５５の間に配置され、圧電素子５４に与圧を与えるためのバイアスバネ，６３は流体シールである。
【００８５】
積層型の圧電素子の場合、超磁歪素子と比べて、同一長さに対するストロークは小さくなるが、電磁コイルが不要なため外径を小さくできる。したがってマルチノズル化を図るときに有利となる。
【００８６】
以上、本発明の実施例として、「限定された時間内で吐出流量をON,OFFさせる方法」について説明した。以下、「任意のタイミングで吐出流量をON,OFFさせる方法」の実施例について説明する。
【００８７】
すなわち、以下示す本発明の第３実施例は、吐出通路に形成される閉空間の容積変化をもたらす第１のアクチュエータと、通路面積を遮蔽・開放する第２のアクチュエータの組み合わせにより、吐出流量を任意のタイミングでON,OFFできる切れ味のよい流量制御を可能としたものである。
【００８８】
図１２において１０１は第１のアクチュエータであり、実施例では超磁歪素子等による電磁歪型のアクチュエータをもちいた。１０２は第１のアクチュエータ１によって駆動されるピストン、１０３はこのピストン１０２を吐出側で収納するスリーブ、１０４はアクチュエータ１０１を収納するハウジングである。
【００８９】
１０５は超磁歪材料から構成される円筒形状の超磁歪ロッドであり、この超磁歪ロッド１０５はバイアス永久磁石（Ａ）１０６、（Ｂ）１０７を上下に挟んだ形で、上部ヨーク１０８とヨーク材を兼ねたスリーブ１０２の間に固定されている。
【００９０】
１０９は超磁歪ロッド１０５の長手方向に磁界を与えるための磁界コイル、１１０は円筒形状のヨークでありハウジング１０４に収納されている。
【００９１】
ピストン１０２とスリーブ１０３の間には、超磁歪ロッド１０５に機械的な軸方向与圧を与えるバイアスバネ１１１が設けられている。
【００９２】
１１２は部材１０８、１０６、１０５、１０７、１０２を貫通して設けられたシール軸、１１３はこのシール軸を軸方向に駆動する直動型である第２のアクチェータである。実施例では、この直動型のアクチェータ１１３に大きなストロークが得られるボイスコイル型リニア・アクチェータを用いた。
【００９３】
１１４はスリーブ１０３に形成された吸入口、１１５はノズル部、１１６はこのノズル部１１５に形成された吐出ノズルである。
【００９４】
１１７はスリーブ１０３とピストン１０２で形成される流体輸送室であり、ピストン１０２及びシール軸１１２の吐出側端面とその対向面及びスリーブ１０３の間で、吐出流量を制御する流量制御部１１８が構成されている。
【００９５】
図１３〜１６は本実施例のディスペンサーの作動プロセスの原理図を、流量制御部１１８近傍の拡大図と共に示すものである。
【００９６】
１１９はピストン１０２の吐出側端面、１２０はシール軸の吐出側端面に形成された円錐形状の凸部、１２１はその対向面であり、吐出ノズル側に形成された円錐形状の凹部である。ピストン１０２の吐出側端面１１９、スリーブ１０３の内面、部材１１９、１２０の対向面１２２により、ピストン１０２の上昇・下降によって、容積の変化する内部空間１２３を形成している。
【００９７】
また円錐形状の凸部１２０と凹部１２１の組み合わせにより、シール軸１１２の上昇・下降によって、吐出流量を開放・遮断する吐出バルブ１２４を構成している。１２５はピストン１０２の吐出側外周面とスリーブ１０３内面で形成された流体絞り部である。
【００９８】
図１４は吐出遮断直前の状態にあり、ピストン１０２は静止しており、またその吐出側端面１１９は最下端の位置にある。またシール軸先端の凸部１２０は、上方の位置にあり、ピストン１０２に収納されている。
【００９９】
この段階では、流体輸送室１１７内の加圧流体は、流体絞り部１２５を通過し、内部空間１２３から吐出ノズル１１６を経て外部に吐出される。
【０１００】
図１５は吐出遮断中の状態を示し、図の矢印のごとくピストン１０２は上昇中である。ピストン１０２の端面１１９およびその対向面の間隔が急峻に変化することにより、内部空間１２３の圧力は急降下する。内部空間１２３の圧力:Pに対して、大気圧をP₀としたとき、P＜P₀となれば流体の流出は遮断される。
【０１０１】
この段階で、吐出ノズル１１６、円錐形状の凸部１２０、凹部１２１近傍にある流体は、遠心方向に流動していく。
【０１０２】
図１４の始めの段階では、シール軸１１２はまだ下降せず初期の位置にある。凸部１２０、凹部１２１近傍にある流体が、吐出ノズル１１６から逆流してきた空気と入れ替わった時、シール軸１１２はすみやかに下降を開始する。
【０１０３】
細径のシール軸１１２が急降下しても、シール軸１１２周辺には空気以外の流体はないため、内部空間１２３の圧力にはなんら影響を与えない。
【０１０４】
たとえばスクイーズ圧力の発生は無く、吐出流量はゼロの状態を保つ。
【０１０５】
図１５は吐出流量が遮蔽された状態を示す。吐出バルブ１２４は機械的にギャップがゼロの状態になるが、粉流体が本ディスペンサーの輸送流体の場合でも、粉流体そのものが近傍に存在しないため、
▲１▼粉体の圧搾破損による流路の詰まり
▲２▼粉体破損による流体の特性変化
等のトラブルは発生しない。
【０１０６】
ピストン１０２が最上段に到達し上昇速度がゼロになると、内部空間１２３の圧力は急速に元の高い圧力に復帰し、一度遠心方向に流動した流体は再度中心部に引き戻される。しかしこの段階では、円錐形状の凸部１２０、凹部１２１は既に噛み合っており、吐出通路は完全に遮蔽されている。
【０１０７】
さて本実施例の効果を正確に把握するために、第１の実施例の場合と同様に理論解析をおこなった。第１の実施例と異なる解析条件のみを、表２に示す。また上記条件下で得られる時間に対する吐出流量の解析結果を図１６に示す。
【０１０８】
（１）解析のスタート段階（ｔ＝０）で、流量（圧力）の初期値を適当な値を仮定しているが、すみやかに一定値に収束する。０＜ｔ＜0.03秒の間は連続描画の状態にある。
【０１０９】
（２）ｔ＝0.03秒でピストンが上昇を始めると、吐出流量は急速に低下し、0.01秒程度の立下り時間で吐出は遮断される。
【０１１０】
（３）t>0.04秒以降、吐出流量は完全に遮断された状態を保つ。t=0.06秒までピストンは上昇中である。
【０１１１】
図１７、図１８に、ピストン端面１１９とその対向面間の流体の流速ベクトルの解析結果を示す。
【０１１２】
流体絞り部１２４は、実施例ではピストン１０２の外周部とシリンダ１０３の内面の間に形成しているが、解析モデルでは、ピストン端面１１９と同一平面上にあると仮定している。
【０１１３】
図１７は連続塗布中の状態（図１３）を示し、ピストン端面にあるすべての流体は、吐出ノズルのある中心部に向かって流動している。
【０１１４】
図１８は吐出遮断中の状態（図１４）を示し、図中の矢印のごとく、吐出ノズルから出た流体は、遠心方向に逆流していることがわかる。
【０１１５】
【表２】

【０１１６】
以下、図１９を用いてピストン１０２とシール軸１１２の位置・速度の制御方法の一例について補足説明する。
【０１１７】
ステップaの段階で、連続塗布していた吐出遮断の指令が入ると、ピストン１０２は上昇を開始する。しかしシール軸１１２は、吐出ノズル１２４近傍（円錐形状の凸部１２０、凹部１２１で構成）の流体が完全に排除されて無くなるステップｂの段階まで、下降を開始しない。ステップｂの段階になると、シール軸１１２はステップｃまで急降下し、以降ステップｄまで緩やかに下降する。
【０１１８】
この理由は、流体制御部の凸部１２０と凹部１２１間の衝撃的な機械接触による磨耗紛の発生などを回避するためである。ピストン１０２は、シール軸１１２が停止してもまだ上昇中であるが、ステップｅの段階で停止する。
【０１１９】
なを、シール軸１１２が下降を開始する前段階（ステップaとｂの区間）で、既に吐出は遮断されているため、ステップｂ以降のピストン１０２とシール軸１１２に必要な操作は、本ディスペンサーの流量遮断の「切れ味のよさ」になんら影響を与えない。
【０１２０】
ステップｆの段階で吐出開始の指令が入ると、ピストン１０２は急速に下降を開始する。ピストン１０２が急降下すると、スクイーズ効果により流体制御部近傍の圧力は急上昇する。しかしピストン１０２の移動速度がゼロとなるステップgの段階で、圧力は瞬時に定常状態に復帰する。このステップgの段階で、シール軸１１２は上昇を開始し、吐出通路は開放されるため、ピストン１０２の急降下による圧力上昇が吐出流量に影響を与えることは無い。
【０１２１】
なを、吐出遮断の状態（ステップeからｆの区間）で、予めピストン１０２を定常位置まで下降させておいてもよい。
【０１２２】
シール軸１１２は、第２のアクチュエータの応答性の許される範囲の高速で急上昇すれば、極めて短い立ち上がり時間で吐出開始ができる。
【０１２３】
実施例では、第２のアクチュエータにボイスコイル型リニア・アクチェータを用いたが、適用対象に用いるアクチェータのストロークが小さくて良い場合は、超磁歪素子などの電磁歪素子を用いても良い。あるいは、応答性がさほど要求されない適用対象ならば、第１、第２のアクチュエータを共にボイスコイル型等を用いてもよい。
【０１２４】
以下、本発明の第４実施例について図２０を用いて説明する。
【０１２５】
前述した第３実施例では、第１と第２の２つの独立したアクチュエータを用いて、ピストンとシール軸を駆動した。以下示す第４実施例では、ディスペンサー構造の簡素化を図るために、一個のアクチュエータの両出力端を利用して、ピストンとシール軸のそれぞれを逆位相で駆動させたものである。
【０１２６】
図２０において２０１は第１と第２のアクチュエータを兼ねた超磁歪素子による直動型アクチュエータである。２０２は前記アクチュエータによって駆動されるピストン、２０３はこのピストン２０２を吐出側で収納するスリーブ、２０４はアクチュエータ２０１を収納するハウジングである。
【０１２７】
２０５は超磁歪材料から構成される円筒形状の超磁歪ロッドである。この超磁歪ロッド２０５はバイアス永久磁石（Ａ）２０６、（Ｂ）２０７を上下に挟んだ形で、上部ヨーク２０８とヨーク材を兼ねたスリーブ２０２の間に固定されている。
【０１２８】
２０９は超磁歪ロッド２０５の長手方向に磁界を与えるための磁界コイル、２１０は円筒形状のヨークでありハウジング２０４に収納されている。
【０１２９】
２１１は上部ヨーク２０８と一体化したシール軸であり、超磁歪ロッド２０５を貫通して設けられている。またこのシール軸２１１は、バイアス永久磁石（Ａ）２０６を中間に挟持した形で、超磁歪ロッド２０５の上端に固定されている。シール軸２１１は上方にも伸びており、上部ハウジング２１２に設けられた軸受部２１３により上端で支持されている。
【０１３０】
またピストン２０２は、シール軸２１１同様に、バイアス永久磁石（Ｂ）２０７を中間に挟持した形で、超磁歪ロッド２０５の下端に固定されている。
【０１３１】
上部ヨーク２０８と上部ハウジング２１２の間、及びピストン２０２とスリーブ２０３の間には、超磁歪ロッド２０５に機械的な軸方向与圧を与えるバイアスバネ２１４，２１５が設けられている。
【０１３２】
２１６はスリーブ２０３に形成された吸入口、２１７はノズル部、２１８はこのノズル部に形成された吐出ノズルである。
【０１３３】
２１９はスリーブ２０３とピストン２０２で形成される流体輸送室である。また、ピストン２０２の吐出側端面とその対向面及びスリーブ２０３の間で、ピストン２０２の上昇・下降により容積が変化する内部空間２２０を形成している。
【０１３４】
上記構成により、超磁歪素子の電磁コイル２０９に電流を印加すると、超磁歪ロッド２０５は印加電流の大きさに比例して伸縮する。このとき、超磁歪ロッド２０５の両端の変位は、超磁歪ロッドに軸方向与圧を与える２つのバイアスバネ２１４、２１５の剛性の大きさで決まる。もし２つのバイアスバネ２１４、２１５の剛性が等しければ、超磁歪ロッド２０５の両端は逆位相でかつ同一の変位量だけ移動する。すなわち、超磁歪ロッド２０５の両端に固定されたピストン２０２とシール軸２１１は、互いに逆方向に同一の変位量だけ移動する。
【０１３５】
ピストン２０２とシール軸２１１のストロークを変える場合は、２つのバイアスバネ２１４、２１５の剛性比を変えればよい。
【０１３６】
この点を利用して、本実施例では一個の超磁歪アクチュエータにより、吐出ON,OFFの機能を持たせることができる。
【０１３７】
図２１(イ)(ロ)は、連続塗布から吐出遮断の状態への以降を示すものである。実施例では、中空の超磁歪ロッドを用いたが、中空にできるならば、たとえば積層型の圧電素子を用いてもよい。
【０１３８】
以上、本発明の実施例を、Ｉ．限定された時間内で吐出流量をON,OFFさせる方法、ＩＩ．任意のタイミングで吐出流量をON,OFFさせる方法、の２つに分けて説明した。以下示す実施例は、上記Ｉ、ＩＩのいずれにも適用できるものである。
【０１３９】
図２２は、本発明の第５実施例を示すもので、外部圧力源に頼らずに、ディスペンサー自身に圧力発生源を持たせたものである。
【０１４０】
すなわち、第５実施例では、超磁歪素子を用いてピストンとシール軸を軸方向に駆動すると共に、非接触で電力供給できる超磁歪素子の特徴を利用して、モータを用いて、このピストンとシール軸を共に回転させたものである。
【０１４１】
図２２において３０１は直動型アクチュエータであり、超磁歪素子等による電磁歪型のアクチュエータ、静電型アクチュエータあるいは電磁ソレノイド等より構成される。実施例では、高い位置決め精度が得られ、高い応答性を持つと共に大きな発生荷重が得られる超磁歪素子を用いた。
【０１４２】
３０２はアクチュエータ３０１によって駆動されるピストン、３０３はこのピストン３０２を吐出側で収納する固定スリーブ、３０４は前記アクチュエータ１を収納するハウジングである。
【０１４３】
３０５は超磁歪材料から構成される円筒形状の超磁歪ロッドである。この超磁歪ロッド３０５はバイアス永久磁石（Ａ）３０６、（Ｂ）３０７を上下に挟んだ形で、上部ヨーク３０８とヨーク材を兼ねたピストン３０２の間に固定されている。
【０１４４】
３０９は超磁歪ロッド３０５の長手方向に磁界を与えるための磁界コイル、３１０は円筒形状のヨークでありハウジング３０４に収納されている。
【０１４５】
前記永久磁石Ａ、Ｂは、超磁歪ロッド３０５に予めに磁界をかけて磁界の動作点を高めるもので、３０５→３０６→３０８→３１０→３０２→３０７→３０５により、超磁歪ロッド３０５の伸縮を制御する閉ループ磁気回路を形成している。すなわち、部材３０５〜３１０により、磁界コイルに与える電流で超磁歪ロッドの軸方向の伸縮を制御できる超磁歪アクチュエータ３０１を構成している。
【０１４６】
３１１は上部ヨーク３０８と一体化したシール軸であり、超磁歪ロッド３０５を貫通して設けられている。またこのシール軸３１１は、バイアス永久磁石（Ａ）３０６を中間に挟持した形で、超磁歪ロッド３０５の上端に固定されている。
【０１４７】
シール軸３１１は上方にも伸びており、上部ハスリーブ３１２に設けられた軸受部３１３により上端で支持されている。
【０１４８】
またこの上部スリーブ３１２は、玉軸受３１４を介在して中間ハウジング３１５により回転自在に支持されている。
【０１４９】
またピストン３０２は、シール軸３１１同様に、バイアス永久磁石（Ｂ）３０７を中間に挟持した形で、超磁歪ロッド３０５の下端に固定されている。
【０１５０】
上部ヨーク３０８と上部スリーブ３１２の間、及びピストン３０２と下部スリーブ３１６の間には、超磁歪ロッド３０５に機械的な軸方向与圧を与えるバイアスバネ３１７，３１８が設けられている。
【０１５１】
上記構成により、超磁歪素子の電磁コイル３０９に電流を印加すると、超磁歪ロッド３０５は印加電流の大きさに比例して伸縮する。このとき、超磁歪ロッド３０５の両端の変位は、超磁歪ロッドに軸方向与圧を与える２つのバイアスバネ３１７、３１８の剛性の大きさで決まる。ピストン３０２とシール軸３１１のストロークを変える場合は、第４実施例同様に、２つのバイアスバネ３１７、３１８の剛性比を変えればよい。
【０１５２】
この点を利用して、本実施例では一個の超磁歪アクチュエータにより、吐出ON, 吐出OFFの両方の機能を持たせることができる。
【０１５３】
シール軸３１１は円筒形状をした上部スリーブ３１２を貫通して、さらに上方向にも伸びている。３１９はシール軸３１１に回転運動を与えるモータであり、実施例ではＤＣサーボモータを用いており、３２０はモータロータ、３２１はモータステータ、３２２はモータステータを収納する上部ハウジングである。
【０１５４】
上部ハウジング３２２の上部には、シール軸３１１の回転速度を検出するためのエンコーダ３２３が設けられている。さらにその上部中心位置に、中心軸の端面位置を検出する変位センサー３２４が配置されている。
【０１５５】
ピストン３０２の吐出側の一部を収納する下部スリーブ３１６は、ハウジング３０４との間に設けられた玉軸受３２５によって回転自在に支持されている。
【０１５６】
３２６はピストン３０２とシール軸３１１の連結部である。
【０１５７】
３２７は固定スリーブ３０３に形成された吸入口、３２８はノズル部、３２９はこのノズル部３２８に形成された吐出ノズル、３３０はピストン３０２と固定スリーブ３０３の相対移動面に形成された流体を圧送するねじ溝である。
【０１５８】
部材３０２、３０３により、流体を外部から吸入し吐出側に圧送する流体輸送室３３１を形成している。またピストン３０２外周部の吐出側端部と固定スリーブ３０３の内面の間で、他と比べて隙間の狭い流体絞り部３３２が形成されている。
【０１５９】
この流体絞り部３３２は、ねじ溝ポンプの隙間が狭い場合は、形成しなくてもよい。また、ピストン３０２の吐出側端面とその対向面及び固定スリーブ３０３の間で、ピストン３０２の上昇・下降により容積が変化する内部空間３３３を形成している。
【０１６０】
シール軸３１１の吐出側端部とその対向面の間で、シール軸３１１の上昇・下降により、吐出通路面積を可変できる吐出バルブ３３４を構成している。
【０１６１】
すなわち、この内部空間３３３と吐出バルブ３３４により、任意のタイミングで吐出流量をON,OFFさせる流量制御部３３５を構成している。
【０１６２】
ちなみに、シール軸３１１に与えられた回転運動は、図２３に示すようなピストン３０２とシール軸３１１の連結部３２６によって、ピストン３０２に与えられる。すなわち、シール軸３１１はピストン３０２に対して、回転のみを伝達し、相対的な直線運動はフリーとなるような連結部形状（角型断面）となっている。
【０１６３】
上記構成により、本実施例の流体供給装置では、ピストン３０２とシール軸３１１は回転運動と微少変位の直線運動の制御を同時に、かつ独立して行うことができる。
【０１６４】
さらに実施例では、直動型アクチュエータ３０１に超磁歪素子を用いたために、超磁歪ロッド３０５（及びピストン３０２とシール軸３１１）を直線運動させるための動力を、外部から非接触で与えることができる。すなわち、本構成のディスペンサーでは、モータを回転させたままで、数メガヘルツの周波数特性を持つ電磁歪素子の特徴を活かし、高いレスポンスで吐出流量の制御ができる。
【０１６５】
実施例では、アクチュエータ３０１（超電磁歪素子）の上部にモータを配置したが、この逆の配置の構成でもよい。
【０１６６】
本実施例のディスペンサーを用いれば、外部の圧力源を用いないで、第４実施例（図２０）と同様な用途に適用できる。すなわち、「任意のタイミングで吐出流量をON,OFFさせる方法」として、塗布行程に適用できる。
【０１６７】
生産工場内に装備されたエアー圧力源の圧力の大きさには制約があるが、本実施例のねじ溝ポンプの最大圧力は、回転数、隙間、ねじ溝形状などのパラメータの選択で自在に設定できる。工場配管の圧力の基準が、５kg/cm²程度であるのに対して、ねじ溝ポンプでは、数１０〜１００kg/cm²の圧力を得ることも可能である。その結果、圧力条件の制約が解除され、たとえば小径ノズルによる大流量吐出もできる。
【０１６８】
シール軸３１１が回転できることを利用して、シール軸３１１の吐出側端面とその対向面の相対移動面に、図２４で示すようなスラスト動圧シール３３６を設ければ、非接触の状態で吐出を遮断することができる。図の黒く塗りつぶした部分がスパイラルグルーブの溝３３７である。
【０１６９】
図２４において、曲線(イ)は動圧シールの隙間に対する発生圧力特性の一例を示す。
【０１７０】
動圧シールの外径が小さい場合、隙間δに対する発生圧力（シール圧）Pの特性は非線形であり、かつ隙間→０としたとき、急激にその発生圧力は上昇する。一方、ねじ溝ポンプの発生圧力は、隙間δの変化に依存しない。したがって、図２４の例では、δ＜δ₁（≒2.5μｍ）のとき、吐出は遮蔽されることがわかる。
【０１７１】
図２５は、吐出遮蔽中の状態をモデル的に示したものである。
【０１７２】
流体３３８中に分散している粉体３３９の流径をたとえばdf=10μｍとし、シール軸３１１とその対向面の間隙部３４０の隙間をたとえばδ=2.5μｍとする。このように、δ＜dfであったとしても、本実施例では、粉体３３９の機械的な圧搾・破壊は生じない。図２５の状態では、動圧シール３３６のポンピング作用によって、間隙部３４０の流体は常に遠心方向の力を受けており、粉体は外周部からこの部分に侵入することはない。
【０１７３】
一方、シール軸３１１がまだ下降中であり、間隙部３４０の隙間δがまだ大きい時も粉体の圧搾・破壊は生じない。その理由は第３、第４の実施例で説明したように、閉空間３３３の容積の急峻な増大とそれに追従する圧力効果により、シール軸３１１が最下端に到達した時点では、吐出バルブ３３４近傍には粉流体は既に存在しないからである。
【０１７４】
以上の実施例により、本発明の次の効果
▲１▼高速流量遮断と開始ができる
▲２▼粉体の圧搾破損による流路の詰まり、流体の特性変化などのトラブルが発生しない
すなわち、上記▲１▼▲２▼の両方を満足する塗布行程を実現できる。
【０１７５】
実施例では、吐出バルブ近傍の粉流体を排除するために、▲１▼内部空間に急峻な容積変化を与える、▲２▼吐出バルブを開閉させる、上記▲１▼▲２▼の動作を逆位相で与えるアクチェータを利用した。
【０１７６】
さて、本実施例がサーボモータを用いていることを利用し、次のような方法でも本発明を適用することができる。
【０１７７】
すなわち、（１）モータの回転数制御による流量制御方法と、（２）閉空間の容積を高速アクチェータを用いて急峻に変化させる方法、の上記(1)(2)を組み合わせても、両者の長所を活かして、かつ短所を解消する流量制御を実現することができる。この場合は、シール軸とピストンのいずれかは上下動の機能を省略してもよい。たとえば、図２２においてピストンは回転するだけで上下動は行わず、シール軸のみが上昇・下降を行うものとする。この場合のシール軸は、図２２のピストンに代わる役割を担うため、外径は大きめに設定すればよい。
【０１７８】
たとえば、吐出遮断時には
（１）シール軸３１１の上昇開始と同時にモータ３１９を回転停止させる。前述したように、シール軸３１１の上昇により、0.01秒あるいはそれ以下のオーダーで吐出流量は遮断される。但し、モータの回転停止までには、たとえば、0.05秒程度を必要とするが、その間はシール軸３１１は上昇中の状態にさせる。
【０１７９】
（２）モータ３１９が停止すると、すみやかに緩やかな逆転を開始させる。ねじ溝ポンプの作用により、流量制御部３３５近傍に停留していた流体は吸入口３２７に向かって逆流する。流量制御部３３５近傍の紛流体が無くなり、吐出ノズル３２９から流入した空気と入れ替わったとき、シール軸３１１を下降させ、吐出ノズル３２９の開口部を遮蔽する。
【０１８０】
また、吐出開始時には、
（３）予めモータ３１９の回転を開始させておく。モータの回転数が定常状態になっていることをエンコーダ３２３信号から確認して、シール軸３１１を急上昇かつ急停止させる。急停止すれば、すみやかに吐出は開始される。
【０１８１】
その他、粉体の圧搾破損を発生させない方法として、
▲１▼吸入口に繋がる圧力供給源の圧力を負圧に急変させる。
【０１８２】
▲２▼外部に設置した負圧源と流量制御部を、高速で開閉するバルブを介して連絡する。
【０１８３】
上記いずれの方法でも、粉体の圧搾・破壊を生じないで、吐出バルブを完全遮蔽あるいは粉体の流径以下の隙間で動圧シールを構成することができる。
【０１８４】
動圧シールを構成する場合はモータ駆動は必要だが、完全遮蔽の場合は使用しなくてよい。
【０１８５】
なを本発明の明細文において、ピストン、シール軸、シリンダなどの表現は円柱形状、円筒形状の部材を連想するが、本発明の適用範囲はこれらの特定形状に制約されるものではない。たとえば、ピストンはダイヤフラムのような薄板形状でもよい。シール軸とその対向面で構成される吐出バルブは、通路面積を遮蔽・開放あるいは変化させることができる部材ならば、どのような形状の組み合わせでもよい。
【０１８６】
実施例において、内部空間の容積変化による急峻な圧力変化は、数ミクロンから数百ミクロンの狭い隙間を変化させることによって生じるスクイーズ圧力によるものである。
【０１８７】
このスクイーズ圧力と、通常、たとえばエアーシリンダのピストンを圧縮・収縮させることによる圧力変化とは原理が異なる。
【０１８８】
後者は流体の圧縮性に依存し、体積の変化に対して圧力の変化が時間遅れを伴う。
【０１８９】
前述したエアーパルス方式のディスペンサーの応答性に限界があるのは、この流体の圧縮性に依存するからである。
【０１９０】
それに対して、前者のスクイーズ圧力は粘性流体の動圧効果によるものであり、体積の変化に対する時間遅れはない。すなわち隙間の変化に即座に圧力が増減するのである。
【０１９１】
実施例では、このように即座に圧力が増減することを利用して、流量制御部を構成している。本発明は流体の圧縮・膨張を利用することもできるが、スクイーズ圧力を利用する方が、応答性の点で好ましい。
【０１９２】
さて、もう一度本発明の第１，２の実施例である「限定された時間内で吐出流量をON,OFFさせる方法」に戻り、その欠点をカバーする実施例について説明する。前記実施例は、吐出通路に繋がる閉空間に急峻な容積変化を与えることにより、その鋭敏な圧力降下を利用して、吐出遮蔽を行うものであった。しかし吐出遮蔽が有効な時間は閉空間の容積が増大中の間のみである。
【０１９３】
そこで以下示す２つの流量制御手段、すなわち、
▲１▼第１の流量制御手段 …内部空間の容積を増減させる方法で、高速レスポンスであるが、遮蔽時間は有限である。
【０１９４】
▲２▼第２の流量制御手段 …第１の流量制御手段よりも応答性は低いが、遮蔽時間に制約はない。
【０１９５】
すなわち、上記▲１▼▲２▼の組み合わせにより、それぞれの長所を活かし、欠点を解消するディスペンサーが実現できる。
【０１９６】
図２６は、第２の流量制御手段に流路切り替えバルブ４００を用いた第６実施例を示すもので、吐出ノズルの中間部にこのバルブ４００を配置したものである。
【０１９７】
４０１はピストン、４０２は固定スリーブ、４０３はハウジング、４０４は吐出部、４０５は下流側吐出ノズル、４０６はバイパス通路、４０７は内部空間４０８を含む流量制御部である。
【０１９８】
上記構成において、第１の流量制御手段の許容遮蔽時間をT₁とし、第２の流量制御手段の立ち上がり時間をT₂とする。たとえば、第１の実施例の具体仕様で、ピストンストローク：Xst＝50μｍ、ピストンの上昇速度：v=1.0mm/secとすれば、T₁＝0.05秒であった。流路切り替えバルブ４００は、たとえばDCサーボモータ、あるいは揺動モータなどを用いれば、0.03<T₂<0.05秒であった。
したがって、T₁＞T₂のため、本実施例の適用条件を満足できる。
【０１９９】
（１）まず吐出遮蔽時には、ピストン４０１の上昇（第１の流量制御手段）と流路切り替えバルブ４００を同時に動作する。動作開始から、ｔ＝0.01秒以下で吐出は遮蔽される。さらにｔ＝0.03〜0.05秒で、流路切り替えバルブ４００により、大気に繋がる吐出通路は遮蔽される。その後、圧力が高圧に復帰した流体はバイパス通路を通じて外部へ流出していく。
【０２００】
（２）吐出開始時には、ピストン４０１を予め所定の位置にまで下降させておく。流路切り替えバルブ４００の応答時間は分かっているため、その待ち時間を予測した上で吐出を開始する。
【０２０１】
以上、本発明の明細文では、「任意のタイミングで吐出流量をON,OFFさせる方法」と「限定された時間内で吐出流量をON,OFFさせる方法」の２つに分けて、その実施例を説明した。しかし、この２つは組み合わせて用いてもよい。たとえば、シール軸の駆動によって、流量遮断できる機能をもっているが、さらに第２の流量制御手段を用いることにより、吐出遮蔽をより確実にするような使用方法でもよい。
【０２０２】
以下、本発明をマルチノズルのディスペンサーに適用した第７実施例について説明する。
【０２０３】
５０１は第１のアクチュエータ（図示せず）によって駆動されるピストン、５０２は第２のアクチュエータ（図示せず）によって駆動されるシールプレート、５０３はこれらの部材を収納するハウジング、５０４はハウジング５０３内部に形成され吸入口（図示せず）、吐出口５０５と連絡する流体輸送室、５０６は流体絞り部である。
【０２０４】
たとえば吐出遮蔽時には、ピストン５０１とシールプレート５０２は矢印の方向に移動し、吐出開放時には共に逆方向に移動する。本ディスペンサーの動作原理は、第３、第４実施例と同様である。
【０２０５】
上記実施例は、「任意のタイミングで吐出流量をON,OFFさせる方法」の一例であるが、第１、第２実施例で示したような、「限定された時間内で吐出流量をON,OFFさせる方法」の場合も同様にマルチノズル化ができる。
【０２０６】
以下、本発明の第８実施例を図２８に示す。
【０２０７】
この実施例は、本発明のディスペンサーの流路の上段側に、吸入側流体の供給圧の確保と低粘度化を目的として、ねじ溝ポンプを設けたものである。
【０２０８】
搬送流体にレオロジー流体を扱う場合、流体の粘度は温度と流体が受けるせん断速度により決まる。本実施例は、レオロジー流体のチクソトロピー性流体挙動により、一度低粘度化した流体は、元の粘度に回復するまで通常ある程度の時間を必要とする、という点を利用している。すなわち、本発明の超小型ディスペンサーに流体を供給する直前の段階で、まずねじ溝ポンプの回転により、流体にせん断作用を与えて流体を低粘度化させるのである。
【０２０９】
複数個の超小型ディスペンサーに対して、外径寸法の大きなねじ溝ポンプは一台でよいため、マルチノズル化した流体供給システムの配置上の支障にはならない。
【０２１０】
６００はマスターポンプであるねじ溝ポンプであり、回転軸６０１、モータロータ６０２、モータステータ６０３、回転軸６０１に形成されたねじ溝６０４、吸入口６０５、吐出口６０６、ハウジング６０７より構成される。
【０２１１】
６０８は本発明の流体供給装置である小型ディスペンサーであり、ねじ溝ポンプ６００と小型ディスペンサー６０８は供給パイプ６０９を介して連絡している。
【０２１２】
本発明による小型ディスペンサー（第１から第６実施例）を、複数本並列配置させて流体供給システムを構成すれば、たとえば平板上に蛍光体材料等を塗布させるプロセスにも適用できる。この場合、塗布材料の吸入側吐出通路は共通でよい。
【０２１３】
各ノズルの吐出量（及びＯＮ，ＯＦＦ）は、各ディスペンサーを個別に制御できるため、自由度が高く、塗布材料の損失が少ない平板面の塗布が可能となる。
【０２１４】
あるいは、共通のハウジングに複数本のディスペンサーの中身を収納するように構成すれば、よりシンプルな構成のマルチノズルを有する塗布装置ができる（図示せず）。
【０２１５】
【発明の効果】
本発明を用いた流体回転装置により、次の効果が得られる。
１．高速吐出遮断と開始ができる。
２．粉体の圧搾破損による流路の詰まり、流体の特性変化などのトラブルが発生しない。
３．シンプルな構成のため、マルチノズル化が容易である。
４．さらに以下示す特徴を、本発明のポンプは合わせ持つことができる。
【０２１６】
▲１▼高粘度流体の高速塗布ができる。
【０２１７】
▲２▼超微少量を高精度で吐出できる。
【０２１８】
本発明を例えば表面実装のディスペンサー、ＰＤＰ，ＣＲＴディスプレイの蛍光体塗布、液晶パネルのシール材塗布等に用いれば、その長所をいかんなく発揮でき、効果は絶大なものがある。
【図面の簡単な説明】
【図１】本発明の第１の実施例によるディスペンサーを示す正面断面図
【図２】上記実施例の吐出部の拡大断面図
【図３】上記実施例の吐出遮蔽のプロセスを示す図
【図４】上記実施例の吐出遮蔽のプロセスを示す図
【図５】上記実施例の吐出遮蔽のプロセスを示す図
【図６】上記実施例の流量特性を示す解析結果を示す図
【図７】上記実施例の電気回路モデル図
【図８】上記実施例の塗布対象を示す図
【図９】上記実施例の塗布開始のタイミングを示す図
【図１０】上記実施例のピストン位置と時間の関係を示す図
【図１１】本発明の第２の実施例によるディスペンサーを示す正面断面図
【図１２】本発明の第３の実施例によるディスペンサーを示す正面断面図
【図１３】上記実施例の吐出遮蔽のプロセスを示す図
【図１４】上記実施例の吐出遮蔽のプロセスを示す図
【図１５】上記実施例の吐出遮蔽のプロセスを示す図
【図１６】上記実施例の流量特性を示す解析結果を示す図
【図１７】上記実施例の流速ベクトル解析結果を示す図
【図１８】上記実施例の流速ベクトル解析結果を示す図
【図１９】上記実施例のストロークと時間の関係を示す図
【図２０】本発明の第４の実施例によるディスペンサーを示す正面断面図
【図２１】上記実施例の吐出遮蔽のプロセスを示す図
【図２２】本発明の第５の実施例によるディスペンサーを示す正面断面図
【図２３】上記実施例の連結部を示す図
【図２４】上記実施例の動圧シールの発生圧力と隙間の関係を示す図
【図２５】上記実施例のシール軸先端のモデル図
【図２６】本発明の第６の実施例による吐出部拡大図
【図２７】本発明の第７の実施例によるディスペンサーを示すもので
（イ）は斜視図
（ロ）はノズル部を示す図
【図２８】本発明の第８の実施例のモデル図
【図２９】従来のエアーパルス方式のディスペンサーを示す図
【符号の説明】
１ アクチュエータ
２ ピストン
３ シリンダ
２０ 流体輸送室
２７ 内部空間
１７ 吸入孔
１９ 吐出孔[0001]
BACKGROUND OF THE INVENTION
The present invention can be used in production processes in the fields of electronic parts, home appliances, etc., and dispenses and discharges various liquids such as adhesives, cream solders, phosphors, greases, paints, hot melts, chemicals, foods, etc. The present invention relates to a fluid supply apparatus.
[0002]
[Prior art]
Liquid discharge devices (dispensers) have been used in various fields in the past, but with the recent needs for downsizing and high recording density of electronic components, a small amount of fluid material can be discharged with high precision and stability. Control technology is required.
[0003]
In addition, there is a great demand for development of a new fluid application means for uniformly applying a phosphor on a display surface such as a CRT or PDP.
[0004]
Taking the field of surface mounting (SMT) as an example, if we summarize the issues of dispensers in the trend of high-speed mounting, miniaturization, high density, high quality, unmanned,
(1) High accuracy of application amount and miniaturization of one application amount
(3) Shortening the discharge time ... Can shut off and start high-speed discharge
▲ 4 ▼ Suitable for high viscosity powder fluid
It is. Conventionally, dispensers such as an air pulse method, a thread groove method, and a micro pump method using an electrostrictive element have been put into practical use in order to discharge a minute flow rate of liquid.
[0005]
[Problems to be solved by the invention]
Among the above-mentioned prior art examples, an air pulse type dispenser as shown in FIG. 5 is widely used, and the technology is introduced in, for example, “Automation Technology '93 .25 No. 7”. This type of dispenser applies a fixed amount of air supplied from a constant pressure source in a container 700 (cylinder) in a pulsed manner, and discharges a certain amount of liquid corresponding to the pressure increase in the cylinder 700 from the nozzle. It is.
[0006]
The air pulse dispenser has a drawback of poor response. This drawback is due to the compressibility of the air confined in the cylinder and the nozzle resistance when passing an air pulse through a narrow gap. In other words, in the case of the air pulse method, the cylinder capacity: C and nozzle resistance: R The time constant of the fluid circuit that is created: T = RC is large, and after applying the input pulse, a time delay of about 0.07 to 0.1 seconds, for example, is started. You must expect.
[0007]
In order to eliminate the disadvantages of the air pulse method, a needle valve is provided at the inlet of the discharge nozzle, and the discharge port is opened and closed by moving a small-diameter spool constituting the needle valve at high speed in the axial direction. Dispensers are in practical use.
[0008]
However, in this case, when the fluid is shut off, the gap between the relatively moving members becomes zero, and the powder having an average particle diameter of several microns to several tens of microns is mechanically squeezed and destroyed. Due to various problems that occur as a result, it is often difficult to apply to powder-mixed adhesives or phosphor coatings.
[0009]
For this purpose, a thread groove type dispenser that is a viscous pump has already been put into practical use. In the case of the thread groove type, since it is possible to select a pump characteristic that does not depend on the nozzle resistance, a preferable result can be obtained in the case of continuous spraying, but intermittent application is not good due to the nature of the viscous pump. Therefore, in the conventional thread groove type,
(1) An electromagnetic clutch is interposed between the motor and the pump shaft, and this electromagnetic clutch is connected or released when discharge is turned ON / OFF.
[0010]
(2) Use a DC servo motor to start or stop rapid rotation.
[0011]
However, since the response is determined by the time constant of the mechanical system in any of the above, there is a restriction on high-speed intermittent operation. Responsiveness is better than the air pulse method, but the shortest time is about 0.05 seconds.
[0012]
In addition, since there are many uncertain factors in the rotational characteristics during the transient response of the pump shaft (at the time of starting and stopping the rotation), it is difficult to strictly control the flow rate, and the coating accuracy is limited.
[0013]
For the purpose of discharging a very small amount of fluid, a micropump using a laminated piezoelectric element has been developed. This micropump usually uses a mechanical passive discharge valve and suction valve.
[0014]
However, in the above-mentioned pump composed of a spring and a ball that opens and closes a discharge valve and a suction valve by a pressure difference, a rheological fluid having poor fluidity and a high viscosity of tens of thousands to hundreds of thousands of centipoises with high flow accuracy and high speed ( It is extremely difficult to discharge intermittently in 0.1 seconds or less.
[0015]
Now, in the field of circuit formation, which has become increasingly precise and ultra-fine in recent years, or in the fields of the formation of electrodes and ribs for picture tubes such as PDP and CRT, the application of sealing materials for liquid crystal panels, and the manufacturing process of optical disks, etc. The following demands regarding technology are strong.
[0016]
(1) It should be possible to stop application quickly after continuous spouting and start a continuous application sharply after a short time. For that purpose, it is ideal that the flow rate can be controlled, for example, on the order of 0.01 seconds.
[0017]
(2) Capable of handling powder fluid. For example, there should be no troubles such as powder breakage or clogging due to mechanical blockage of the flow path.
[0018]
  The present invention is described above.FlourInvolves in the application of minute flow of fluidFluid supply apparatus and method capable of supplying powder fluid with high accuracy and high speed without causing clogging of the flow path due to squeezing damage of powdered fluid in particular The purpose is to provide.
[0019]
In other words, the volume of the narrow closed space formed in the discharge passage is changed abruptly using a high-speed actuator, making it possible to control sharp flow with a simple structure using the sudden drop in pressure. It is.
[0020]
[Means for Solving the Problems]
  Of the present inventionFirstFluid supplyMethodIsIn a fluid supply method for supplying powdered fluid to a space formed by a housing and a sleeve provided outside the piston and fixed to the housing, and discharging the powdered fluid from a discharge nozzle, a discharge side end surface of the sleeve; The relationship between δs and D is D> δs, where δs is the clearance with the facing surface, and D is the clearance in the radial direction of the piston in the space formed by the housing and the sleeve, and Controlling the shutoff and release of the pulverized fluid discharged from the discharge nozzle by moving the piston in an axial direction without contact with the housingIt is characterized by.
[0021]
  In addition, the present inventionSecondThe fluid supply method isIn a fluid supply method for supplying powdered fluid to a space formed by a piston and a housing and discharging the powdered fluid from a discharge nozzle, a gap in a radial direction of the piston is formed in a space formed by the piston and the housing. A squeezed portion formed by an outer peripheral surface of the piston and an inner peripheral surface of the housing, and a powder fluid discharged from a discharge nozzle by axially moving the piston in a non-contact manner with respect to the housing. It is characterized by controlling blocking and opening.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
In the following, embodiments of the present invention will be described in two major parts.
[0023]
I. Method to turn ON / OFF the discharge flow rate within a limited time
II. Method to turn ON / OFF the discharge flow rate at any timing
First, the above I will be described.
[0024]
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.
[0025]
In the present embodiment, in the application process at the mass production site, the constraining condition on the mass production that only a very short time is allowed until the application is restarted after stopping the continuous spraying is used. Depending on the target to be sprayed, there is a case where it is desired to block the coating process only for an instant after continuous spraying for a certain period of time, such as rib formation between RGB of CRT phosphor and PDP in the mass production process.
[0026]
That is, by introducing the fluid control means effective only for this short finite time into the dispenser, it is possible to control the flow rate with extremely sharpness that satisfies the above-described demands on the dispenser.
[0027]
In FIG. 1, reference numeral 1 denotes a direct-acting actuator, which is composed of an electrostrictive actuator such as a giant magnetostrictive element, an electrostatic actuator, or an electromagnetic solenoid. In the examples, in order to discharge a high-viscosity fluid at a high speed intermittently in a minute amount and with high accuracy, a giant magnetostrictive element that can obtain high positioning accuracy, high response, and a large generated load is used.
[0028]
2 is a piston driven by the first actuator 1, 3 is a sleeve for storing the piston 2 at the discharge side end, 4 is a housing for storing the actuator 1, and 5 is a lower housing for fixing the sleeve 3 on the discharge side. is there.
[0029]
6 is a cylindrical giant magnetostrictive rod made of a giant magnetostrictive material, and this giant magnetostrictive rod 6 has a bias permanent magnet (A) 7 and (B) 8 sandwiched between the upper yoke 9 and the yoke material. It is being fixed between the sleeves 3 that also serve as.
[0030]
Reference numeral 10 denotes a magnetic field coil for applying a magnetic field in the longitudinal direction of the giant magnetostrictive rod 16, and 11 denotes a cylindrical yoke which is housed in the housing 4.
[0031]
The permanent magnets (A) and (B) increase the operating point of the magnetic field by applying a magnetic field to the giant magnetostrictive rod 6 in advance, and this magnetic bias can improve the linearity of the giant magnetostriction with respect to the strength of the magnetic field. 6 → 7 → 9 → 11 → 3 → 8 → 6 forms a closed loop magnetic circuit for controlling expansion and contraction of the giant magnetostrictive rod 6. That is, the members 6 to 11 constitute the giant magnetostrictive actuator 1 that can control the amount of expansion and contraction in the axial direction of the giant magnetostrictive rod by the current applied to the magnetic field coil.
[0032]
The giant magnetostrictive material is an alloy of a rare earth element and iron, for example, TbFe2, DyFe2, SmFe2, etc. are known and have been rapidly put into practical use in recent years.
[0033]
The piston 2 is integrated with a cylindrical upper yoke 9 and extends upward, and is accommodated in the upper sleeve 12. The piston 2 is supported by the bearing portion 13 so as to be movable in the axial direction with respect to the upper sleeve 12.
[0034]
A bias spring 14 is provided between the upper sleeve 12 and the upper yoke 9 to apply a mechanical axial pressure to the giant magnetostrictive rod 6. Because the bias spring 14 always applies compressive stress to the giant magnetostrictive rod 6 in the axial direction, the drawback of the giant magnetostrictive element that is weak against tensile stress is eliminated when repeated stress is generated.
[0035]
A displacement sensor 15 that detects the position of the end surface of the piston 2 is adjustably disposed at the center of the upper end of the upper sleeve 12.
[0036]
Reference numeral 16 denotes a piston small diameter shaft which is a small diameter portion of the piston 2, 17 denotes a suction port formed in the lower housing 5, 18 denotes a nozzle portion, and 19 denotes a discharge nozzle formed in the nozzle portion 18. The pressurized fluid that has flowed from the suction port 17 flows into the fluid transport chamber 20 formed by the sleeve 3 and the lower housing 5, and further flows into the discharge nozzle 19 through a fluid throttle portion 21 to be described later.
[0037]
A flow rate control unit 22 that controls the discharge flow rate is configured between the discharge-side end surface of the piston small-diameter shaft 16 and its opposing surface and the lower housing 5.
[0038]
FIG. 2 is an enlarged view of the vicinity of the flow rate control unit 22 described above, 23 is a discharge side end surface of the piston small diameter shaft 16 (piston 2), 24 is a discharge side end surface of the sleeve 3, and 25 is a facing surface of 23 and 24. is there. A fluid seal 26 is provided between the piston small diameter shaft 16 and the inner surface of the sleeve 3. A liquid reservoir 28 is formed at the inlet of the discharge nozzle.
[0039]
The discharge-side end surface 23 of the piston small-diameter shaft 16 and its opposing surface 25 form an internal space 27 whose volume changes as the piston 2 moves up and down.
[0040]
Since the input current and output displacement of the giant magnetostrictive element are in a proportional relationship, the stroke control of the piston 2 (control of the position and speed of the discharge side end face 23) is possible by changing the input current. However, if the position detection means 15 as in this embodiment is provided and feedback control is performed, control with higher accuracy can be performed.
[0041]
Further, in a pump that handles a minute flow rate, the axial displacement of the piston 2 may be a slight displacement of several μm to several tens of μm. If this small amount of displacement is used, the limit of the stroke of the giant magnetostrictive element does not matter.
[0042]
3 to 5 show the operation process of this embodiment. That is, by rapidly increasing the distance between the end surface 23 of the piston small-diameter shaft 16 and the opposed surface 25, the pressure of the internal space 27 upstream of the discharge nozzle is caused by the dynamic pressure effect of the viscous fluid, which is also called the reverse squeeze effect. Is a process in which the flow of fluid from the discharge nozzle is quickly blocked by abruptly dropping.
[0043]
In the specification of the present invention, in order to explain the principle in an easy-to-understand manner, gaps between the members and changes in the position of the members are greatly illustrated. However, in the embodiment, the order is several tens to several hundreds of microns at most.
[0044]
FIG. 3 shows a state immediately before the discharge is cut off, the piston small-diameter shaft 16 is stationary, and the discharge-side end face 23 is at the lowest end position. At this stage, the pressurized fluid in the fluid transport chamber 20 passes through a narrow gap (fluid throttle portion 21) formed by the discharge side end surface 24 of the sleeve 3 and its opposing surface 25, and passes through the discharge nozzle 19 to the outside. Discharged.
[0045]
FIG. 4 shows a state where the discharge is shut off, and the piston small-diameter shaft 16 is rising as shown by the arrow in the figure. When the distance h between the end surface 23 of the piston small diameter shaft 16 and the facing surface 25 thereof changes abruptly, the pressure in the internal space 27 drops rapidly. For the pressure in the internal space 27: P₀P <P₀Then, the outflow of fluid is blocked.
[0046]
When the piston small-diameter shaft 16 reaches the uppermost stage and the ascending speed becomes zero, the pressure in the internal space 27 is quickly restored, and discharge starts.
[0047]
FIG. 5 shows a state where the continuous application has been restored. After completing the predetermined task of shutting off the discharge for a short time, the piston small diameter shaft 16 is slowly descending. At this time, since the lowering speed of the piston small-diameter shaft 16 is small, the pressure in the internal space 27, that is, the discharge flow rate is hardly affected. When the end face 23 reaches the initial position (FIG. 3), the descent stops.
[0048]
Now, the principle and effect of the present invention will be described in more detail using theoretical analysis. When a viscous fluid is present in a narrow gap between opposing planes and the gap distance changes with time, the fluid pressure is the Reynolds equation in the following polar coordinate with a squeeze action term Is obtained by solving
[0049]
[Formula 1]

[0050]
In the equation (1), P is pressure, μ is a viscosity coefficient of fluid, h is a gap between opposing surfaces, r is a radial position, and t is time. The right side is a term that provides a squeeze action effect that occurs when the gap changes.
[0051]
Further, in the case where the liquid reservoir 28 is provided at the discharge nozzle inlet, the pressure of the liquid reservoir, that is, the upstream pressure Pn of the nozzle is considered in consideration of fluid compressibility.
[0052]
[Formula 2]

[0053]
In the equation (2), Qs is an inflow amount taking into consideration the effect discharged from the liquid reservoir by the squeeze action, and Qn is an outflow amount discharged from the liquid reservoir through the discharge nozzle 19 to the atmosphere. Further, k is the bulk modulus of the fluid, and V is the volume of the liquid reservoir 28.
[0054]
The upstream pressure Pn of the nozzle necessary for obtaining the discharge flow rate is obtained by simultaneously solving the equations (1) and (2).
[0055]
Hereinafter, fluid viscosity: μ = 10,000 cps, bulk modulus: K = 300 kg / cm², Boundary part (outer peripheral part of fluid restricting part 21) pressure: Ps = 20 kg / cm²In the case where the fluid control unit 22 is configured under the conditions shown in Table 1 below, an analysis for determining the discharge flow rate was performed.
[0056]
[Table 1]

[0057]
The analysis result of the discharge flow rate obtained under the above conditions is shown in FIG.
[0058]
(1) At the start stage of analysis (t = 0), the initial value of the flow rate (pressure) is assumed to be an appropriate value, but quickly converges to a constant value. During 0 <t <0.03 seconds, a continuous drawing state is maintained.
[0059]
(2) When the piston starts to rise at t = 0.03 seconds, the discharge flow rate decreases rapidly, and the discharge is interrupted immediately with a fall time of about 0.003 sec (3 msec) from the start.
[0060]
(3) In the section of 0.03 <t <0.08 seconds, the discharge flow rate is zero. In this section, the piston is rising at a constant speed. From Table 1, since the piston stroke in the example is Xst = 50 μm and the piston operating time is Tp = 0.05 sec, the ascending speed of the piston is v = 50 μm / 0.05 sec = 1.0 mm / sec.
[0061]
(4) When the piston stops at t = 0.08 seconds, it will immediately return to the continuous application state with a rise time of about 0.01 sec.
[0062]
From the above results, it is possible to control the flow rate with extremely excellent responsiveness of the order of 0.01 seconds or less by the method of the embodiment in which the internal space of the discharge flow path is sharply increased using an actuator with excellent responsiveness. I understand.
[0063]
However, the time when the discharge flow rate is zero is only while the piston is rising. This shielding time is determined by the limit stroke and the rising speed of the actuator.
In the case of an actuator using a giant magnetostrictive element, a displacement of approximately 10 μm is obtained with a length of 10 mm. If a piezoelectric element is employed, the displacement is almost half that amount.
[0064]
Therefore, in the embodiment of FIG. 1, under the conditions in Table 1, for example, if lot 6 of giant magnetostrictive elements having a length of 50 mm is used, the discharge amount can be turned OFF for Tp = 0.05 seconds.
[0065]
In the above analysis, the volume of the liquid reservoir 28 is set large, and the compressibility of the fluid in the liquid reservoir is taken into consideration. However, if the fluid is nearly incompressible, the above-described rise / fall time is determined by the actuator. Can be reduced to near the limit of the response.
[0066]
Incidentally, in the case of magnetostrictive elements such as giant magnetostrictive elements and piezoelectric elements, usually 10-^FourResponsiveness of sec order is obtained.
[0067]
An actuator such as an electromagnetic solenoid can also be applied, and the response is worse by an order of magnitude compared to an electromagnetic strain element, but the stroke restriction (that is, the allowable stop time) is greatly relaxed.
[0068]
In order to easily understand the principle of the present invention intuitively, the flow control unit 22 in FIG. 2 is replaced with an electric circuit model as shown in FIG.
[0069]
In FIG. 7, Ps is the boundary pressure of the fluid restrictor 21, R0 is the fluid resistance of the fluid restrictor 21, Rn is the fluid resistance of the discharge nozzle 19, and Qp is a flow rate source determined by the ascending speed of the piston small diameter shaft 16 and the piston area. Qn indicates the flow rate passing through the discharge nozzle 19. Here, the flow rate Qn passing through the discharge nozzle 19 is
[0070]
[Formula 3]

[0071]
When Qn <0, that is, the discharge is cut off under the following conditions.
[0072]
[Formula 4]

[0073]
From the above equation (4), it is understood that the fluid restrictor 21 needs to have a fluid resistance greater than a certain value in order to enable flow rate control.
[0074]
FIG. 8 shows an application target of the dispenser of this embodiment. Reference numeral 100 denotes an application target, and a dispenser that runs in the horizontal direction blocks the discharge flow rate at t = ts immediately after the dispenser is removed from the application target frame. Furthermore, after the U-turn, the dispenser starts continuous application at t = te. If the time interval from the shut-off to the start is within the allowable stop time Tp, the application can be started at an arbitrary time. In order to start the application, as shown in FIG. 9, ascending the piston may be stopped at an arbitrary time such as t = te1, t = te2.
[0075]
If continuous application is started again, there is a sufficient time until the discharge flow rate is cut off next time. Therefore, as shown in FIG. 10, the piston may be slowly lowered to the initial position. If the term of squeeze action in equation (1): dh / dt is sufficiently small, the change in the discharge flow rate can fall within the allowable flow rate error range.
[0076]
In the present invention, even when the discharge is cut off, there is no section in which the flow path area decreases, so that the following troubles in controlling the flow rate of the powder fluid do not occur.
[0077]
(1) Blockage of the flow path due to squeezing powder
(2) Changes in fluid properties due to powder breakage
The above {circle around (2)} is a trouble that occurs when the capsule is mechanically destroyed when a material for promoting curing is encapsulated in an adhesive in the field of circuit mounting. In the examples of the present invention, as shown in Table 1, the narrowest section was a gap between the end face of the sleeve and its facing face: δs = 30 μm, which was set sufficiently larger than the average particle diameter of the powder.
[0078]
By changing the gap (Xmin in Table 1) between the opposing surface at the lowest point of the piston 16 in the state of continuous application, the change in fluid resistance between the two parallel planes of the piston 16 and the discharge nozzle 19 is utilized. Thus, a certain range of flow rate can be controlled arbitrarily.
[0079]
Since the relationship between the change in fluid resistance and the change in flow rate does not have a time delay element, it is possible to perform flow rate control with extremely excellent response determined by the response of the high-speed actuator.
[0080]
For example, when a line is drawn along a corner of a quadrangular plane, it is often difficult to draw a line with a constant width due to the movement speed of the dispenser at the corner portion. In the case of this dispenser, while detecting the piston position by the displacement sensor 15, the piston 16 may be raised when it is desired to increase the flow rate slightly, and the piston 16 may be lowered when it is desired to decrease the flow rate.
[0081]
The second embodiment of the present invention will be described below.
[0082]
FIG. 11 shows a case where the present invention is applied using a laminated piezoelectric element as an actuator.
[0083]
50 is a piston, 51 is a large piston diameter portion formed on the discharge side of the piston, 52 is a flange portion provided on the top of the piston, 53 is a cylinder, and 54 is sandwiched between the flange portion and the cylinder 53. The laminated piezoelectric element 55 is an upper sleeve, 56 is a bearing portion for supporting the piston 50 formed on the upper sleeve, and 57 is a displacement sensor for detecting the axial position of the piston 50.
[0084]
58 is a suction port formed on the discharge side of the cylinder, 59 is a discharge portion, and 60 is a discharge nozzle. Reference numeral 61 denotes a fluid throttle portion formed by the outer peripheral surface of the piston 50 and the inner peripheral surface of the cylinder. 62 is disposed between the flange portion 52 and the upper sleeve 55, and a bias spring for applying pressure to the piezoelectric element 54, and 63 is a fluid seal.
[0085]
In the case of a laminated piezoelectric element, the stroke for the same length is smaller than that of a giant magnetostrictive element, but the outer diameter can be reduced because an electromagnetic coil is unnecessary. Therefore, it is advantageous when a multi-nozzle is achieved.
[0086]
As described above, the “method for turning ON / OFF the discharge flow rate within a limited time” has been described as the embodiment of the present invention. Hereinafter, an example of “a method of turning ON / OFF the discharge flow rate at an arbitrary timing” will be described.
[0087]
That is, in the third embodiment of the present invention described below, the discharge flow rate is reduced by the combination of the first actuator that changes the volume of the closed space formed in the discharge passage and the second actuator that shields and opens the passage area. It enables sharp flow control that can be turned on and off at any timing.
[0088]
In FIG. 12, reference numeral 101 denotes a first actuator. In the embodiment, an electromagnetic strain type actuator using a giant magnetostrictive element or the like is used. Reference numeral 102 denotes a piston driven by the first actuator 1, 103 denotes a sleeve for storing the piston 102 on the discharge side, and 104 denotes a housing for storing the actuator 101.
[0089]
Reference numeral 105 denotes a cylindrical giant magnetostrictive rod made of a giant magnetostrictive material. The giant magnetostrictive rod 105 is formed by sandwiching bias permanent magnets (A) 106 and (B) 107 vertically, and an upper yoke 108 and a yoke material. It is being fixed between the sleeves 102 which served as both.
[0090]
Reference numeral 109 denotes a magnetic field coil for applying a magnetic field in the longitudinal direction of the giant magnetostrictive rod 105, and 110 denotes a cylindrical yoke which is accommodated in the housing 104.
[0091]
A bias spring 111 is provided between the piston 102 and the sleeve 103 to apply a mechanical axial pressure to the giant magnetostrictive rod 105.
[0092]
112 is a seal shaft provided penetrating the members 108, 106, 105, 107, 102, and 113 is a second-acting second actuator that drives the seal shaft in the axial direction. In the embodiment, a voice coil type linear actuator capable of obtaining a large stroke is used as the direct acting actuator 113.
[0093]
Reference numeral 114 denotes a suction port formed in the sleeve 103, 115 denotes a nozzle portion, and 116 denotes a discharge nozzle formed in the nozzle portion 115.
[0094]
Reference numeral 117 denotes a fluid transport chamber formed by the sleeve 103 and the piston 102, and a flow rate control unit 118 that controls the discharge flow rate is configured between the discharge side end surfaces of the piston 102 and the seal shaft 112 and the opposing surface and the sleeve 103. ing.
[0095]
13 to 16 show a principle diagram of the operation process of the dispenser of this embodiment, together with an enlarged view in the vicinity of the flow rate control unit 118.
[0096]
Reference numeral 119 denotes a discharge-side end face of the piston 102, 120 denotes a conical convex portion formed on the discharge-side end face of the seal shaft, and 121 denotes a conical concave portion formed on the discharge nozzle side. The discharge-side end surface 119 of the piston 102, the inner surface of the sleeve 103, and the facing surface 122 of the members 119 and 120 form an internal space 123 whose volume changes as the piston 102 moves up and down.
[0097]
Further, the combination of the conical convex portion 120 and the concave portion 121 constitutes a discharge valve 124 that opens and closes the discharge flow rate by raising and lowering the seal shaft 112. Reference numeral 125 denotes a fluid throttle portion formed by the discharge-side outer peripheral surface of the piston 102 and the inner surface of the sleeve 103.
[0098]
FIG. 14 shows a state immediately before the discharge is cut off, the piston 102 is stationary, and the discharge side end surface 119 is at the lowermost position. Further, the convex portion 120 at the tip end of the seal shaft is at an upper position and is accommodated in the piston 102.
[0099]
At this stage, the pressurized fluid in the fluid transport chamber 117 passes through the fluid restricting portion 125 and is discharged from the internal space 123 through the discharge nozzle 116 to the outside.
[0100]
FIG. 15 shows a state where the discharge is shut off, and the piston 102 is rising as shown by the arrow in the figure. As the distance between the end surface 119 of the piston 102 and its opposing surface changes sharply, the pressure in the internal space 123 drops rapidly. For the pressure in the internal space 123: P, the atmospheric pressure is P₀P <P₀Then, the outflow of fluid is blocked.
[0101]
At this stage, the fluid in the vicinity of the discharge nozzle 116, the conical convex portion 120, and the concave portion 121 flows in the centrifugal direction.
[0102]
In the initial stage of FIG. 14, the seal shaft 112 is not yet lowered and is in the initial position. When the fluid in the vicinity of the convex portion 120 and the concave portion 121 is replaced with the air flowing backward from the discharge nozzle 116, the seal shaft 112 starts to descend immediately.
[0103]
Even if the small-diameter seal shaft 112 is suddenly lowered, there is no fluid other than air around the seal shaft 112, and thus the pressure in the internal space 123 is not affected at all.
[0104]
For example, no squeeze pressure is generated, and the discharge flow rate is kept at zero.
[0105]
FIG. 15 shows a state where the discharge flow rate is shielded. The discharge valve 124 is mechanically in a state where the gap is zero, but even if the powder fluid is the transport fluid of this dispenser, the powder fluid itself does not exist in the vicinity.
(1) Blockage of the flow path due to squeezing powder
(2) Changes in fluid properties due to powder breakage
Such troubles do not occur.
[0106]
When the piston 102 reaches the uppermost stage and the rising speed becomes zero, the pressure in the internal space 123 quickly returns to the original high pressure, and the fluid that has once flowed in the centrifugal direction is drawn back to the center again. However, at this stage, the conical convex portion 120 and the concave portion 121 are already engaged with each other, and the discharge passage is completely shielded.
[0107]
Now, in order to accurately grasp the effect of the present embodiment, a theoretical analysis was performed in the same manner as in the first embodiment. Only the analysis conditions different from the first example are shown in Table 2. Moreover, the analysis result of the discharge flow rate with respect to the time obtained on the said conditions is shown in FIG.
[0108]
(1) Although the initial value of the flow rate (pressure) is assumed to be an appropriate value at the start stage of analysis (t = 0), it quickly converges to a constant value. During 0 <t <0.03 seconds, a continuous drawing state is maintained.
[0109]
(2) When the piston starts to rise at t = 0.03 seconds, the discharge flow rate decreases rapidly, and the discharge is shut off at the fall time of about 0.01 seconds.
[0110]
(3) After t> 0.04 seconds, keep the discharge flow rate completely shut off. The piston is ascending until t = 0.06 seconds.
[0111]
17 and 18 show the analysis results of the flow velocity vector of the fluid between the piston end surface 119 and the opposed surface.
[0112]
In the embodiment, the fluid restricting portion 124 is formed between the outer peripheral portion of the piston 102 and the inner surface of the cylinder 103. However, in the analysis model, it is assumed that the fluid restricting portion 124 is on the same plane as the piston end surface 119.
[0113]
FIG. 17 shows a state during continuous application (FIG. 13), and all the fluid on the piston end face is flowing toward the central portion where the discharge nozzle is located.
[0114]
FIG. 18 shows a state (FIG. 14) in which the discharge is cut off, and it can be seen that the fluid discharged from the discharge nozzle flows backward in the centrifugal direction as indicated by the arrows in the figure.
[0115]
[Table 2]

[0116]
Hereinafter, an example of a method for controlling the position and speed of the piston 102 and the seal shaft 112 will be supplementarily described with reference to FIG.
[0117]
When the command for shutting off the discharge that has been continuously applied is input at the stage of step a, the piston 102 starts to rise. However, the seal shaft 112 does not start to descend until the step b in which the fluid in the vicinity of the discharge nozzle 124 (consisting of the conical convex portion 120 and the concave portion 121) is completely eliminated and disappears. At the stage of step b, the seal shaft 112 suddenly descends to step c and then gently descends to step d.
[0118]
The reason for this is to avoid the generation of wear powder due to shocking mechanical contact between the convex part 120 and the concave part 121 of the fluid control unit. The piston 102 is still rising even when the seal shaft 112 stops, but stops at the stage of step e.
[0119]
Since the discharge is already cut off before the seal shaft 112 starts to descend (section between steps a and b), the operation necessary for the piston 102 and the seal shaft 112 after step b is performed in this dispenser. This has no effect on the “sharpness” of the flow cut-off.
[0120]
When a discharge start command is input at the stage of step f, the piston 102 starts to descend rapidly. When the piston 102 suddenly descends, the pressure in the vicinity of the fluid control unit rapidly rises due to the squeeze effect. However, at the stage of step g where the moving speed of the piston 102 becomes zero, the pressure instantaneously returns to the steady state. At the stage of step g, the seal shaft 112 starts to rise and the discharge passage is opened, so that the pressure increase due to the sudden drop of the piston 102 does not affect the discharge flow rate.
[0121]
Alternatively, the piston 102 may be lowered to the steady position in advance in the discharge cut-off state (section from step e to f).
[0122]
If the seal shaft 112 rises rapidly at a high speed within a range in which the response of the second actuator is allowed, discharge can be started in a very short rise time.
[0123]
In the embodiment, a voice coil type linear actuator is used as the second actuator. However, when the stroke of the actuator used for the application target may be small, an electromagnetic strain element such as a giant magnetostrictive element may be used. Or if it is the application object for which responsiveness is not required so much, a voice coil type etc. may be used for both the first and second actuators.
[0124]
Hereinafter, a fourth embodiment of the present invention will be described with reference to FIG.
[0125]
In the third embodiment described above, the piston and the seal shaft are driven using the first and second independent actuators. In the fourth embodiment described below, in order to simplify the dispenser structure, the piston and the seal shaft are driven in opposite phases by using both output ends of one actuator.
[0126]
In FIG. 20, reference numeral 201 denotes a direct acting actuator using a giant magnetostrictive element serving as both a first and a second actuator. 202 is a piston driven by the actuator, 203 is a sleeve for storing the piston 202 on the discharge side, and 204 is a housing for storing the actuator 201.
[0127]
Reference numeral 205 denotes a cylindrical giant magnetostrictive rod made of a giant magnetostrictive material. The giant magnetostrictive rod 205 is fixed between an upper yoke 208 and a sleeve 202 serving as a yoke material, with bias permanent magnets (A) 206 and (B) 207 sandwiched vertically.
[0128]
Reference numeral 209 denotes a magnetic field coil for applying a magnetic field in the longitudinal direction of the giant magnetostrictive rod 205, and 210 denotes a cylindrical yoke, which is housed in the housing 204.
[0129]
211 is a seal shaft integrated with the upper yoke 208, and is provided through the giant magnetostrictive rod 205. The seal shaft 211 is fixed to the upper end of the giant magnetostrictive rod 205 with a bias permanent magnet (A) 206 sandwiched therebetween. The seal shaft 211 extends upward and is supported at the upper end by a bearing portion 213 provided in the upper housing 212.
[0130]
Further, like the seal shaft 211, the piston 202 is fixed to the lower end of the giant magnetostrictive rod 205 with a bias permanent magnet (B) 207 sandwiched therebetween.
[0131]
Bias springs 214 and 215 for applying mechanical axial pressure to the giant magnetostrictive rod 205 are provided between the upper yoke 208 and the upper housing 212 and between the piston 202 and the sleeve 203.
[0132]
Reference numeral 216 denotes a suction port formed in the sleeve 203, 217 denotes a nozzle portion, and 218 denotes a discharge nozzle formed in the nozzle portion.
[0133]
Reference numeral 219 denotes a fluid transport chamber formed by the sleeve 203 and the piston 202. Further, an internal space 220 is formed between the discharge-side end surface of the piston 202 and its opposing surface and the sleeve 203, the volume of which changes as the piston 202 moves up and down.
[0134]
With the above configuration, when a current is applied to the electromagnetic coil 209 of the giant magnetostrictive element, the giant magnetostrictive rod 205 expands and contracts in proportion to the magnitude of the applied current. At this time, the displacement at both ends of the giant magnetostrictive rod 205 is determined by the rigidity of the two bias springs 214 and 215 that apply axial pressure to the giant magnetostrictive rod. If the rigidity of the two bias springs 214 and 215 is equal, both ends of the giant magnetostrictive rod 205 move in opposite phases and by the same amount of displacement. That is, the piston 202 and the seal shaft 211 fixed to both ends of the giant magnetostrictive rod 205 move in the opposite directions by the same displacement amount.
[0135]
When changing the stroke of the piston 202 and the seal shaft 211, the rigidity ratio of the two bias springs 214 and 215 may be changed.
[0136]
By utilizing this point, in the present embodiment, a single magnetostrictive actuator can have a discharge ON / OFF function.
[0137]
FIGS. 21 (a) and 21 (b) show the subsequent steps from the continuous application to the discharge blocking state. In the embodiment, a hollow giant magnetostrictive rod is used. However, if it can be made hollow, for example, a laminated piezoelectric element may be used.
[0138]
As described above, the embodiments of the present invention are described in the following. Method for turning ON / OFF the discharge flow rate within a limited time, II. The method has been described in two ways: ON / OFF of the discharge flow rate at an arbitrary timing. The following embodiments can be applied to both I and II.
[0139]
FIG. 22 shows a fifth embodiment of the present invention, in which the dispenser itself has a pressure generating source without relying on an external pressure source.
[0140]
That is, in the fifth embodiment, the piston and the seal shaft are driven in the axial direction using the giant magnetostrictive element, and the motor is used to take advantage of the characteristics of the giant magnetostrictive element that can supply power without contact. The seal shaft is rotated together.
[0141]
In FIG. 22, reference numeral 301 denotes a direct acting actuator, which is composed of an electromagnetic distortion type actuator such as a giant magnetostrictive element, an electrostatic type actuator, an electromagnetic solenoid or the like. In the embodiment, a giant magnetostrictive element that can obtain high positioning accuracy, has high responsiveness, and obtains a large generated load is used.
[0142]
Reference numeral 302 denotes a piston driven by the actuator 301, 303 denotes a fixed sleeve for storing the piston 302 on the discharge side, and 304 denotes a housing for storing the actuator 1.
[0143]
Reference numeral 305 denotes a cylindrical giant magnetostrictive rod made of a giant magnetostrictive material. The super magnetostrictive rod 305 is fixed between an upper yoke 308 and a piston 302 serving also as a yoke material, with bias permanent magnets (A) 306 and (B) 307 sandwiched vertically.
[0144]
309 is a magnetic field coil for applying a magnetic field in the longitudinal direction of the giant magnetostrictive rod 305, and 310 is a cylindrical yoke housed in the housing 304.
[0145]
The permanent magnets A and B increase the operating point of the magnetic field by applying a magnetic field to the giant magnetostrictive rod 305 in advance, and the giant magnetostrictive rod 305 is expanded and contracted by 305 → 306 → 308 → 310 → 302 → 307 → 305. A closed loop magnetic circuit to be controlled is formed. That is, the members 305 to 310 constitute a giant magnetostrictive actuator 301 that can control the expansion and contraction of the giant magnetostrictive rod in the axial direction by a current applied to the magnetic field coil.
[0146]
Reference numeral 311 denotes a seal shaft integrated with the upper yoke 308, and is provided through the giant magnetostrictive rod 305. The seal shaft 311 is fixed to the upper end of the giant magnetostrictive rod 305 with a bias permanent magnet (A) 306 interposed therebetween.
[0147]
The seal shaft 311 extends upward and is supported at the upper end by a bearing portion 313 provided on the upper sleeve 312.
[0148]
The upper sleeve 312 is rotatably supported by an intermediate housing 315 with a ball bearing 314 interposed therebetween.
[0149]
Further, like the seal shaft 311, the piston 302 is fixed to the lower end of the giant magnetostrictive rod 305 with a bias permanent magnet (B) 307 sandwiched therebetween.
[0150]
Bias springs 317 and 318 are provided between the upper yoke 308 and the upper sleeve 312 and between the piston 302 and the lower sleeve 316 to apply a mechanical axial pressure to the giant magnetostrictive rod 305.
[0151]
With the above configuration, when a current is applied to the electromagnetic coil 309 of the giant magnetostrictive element, the giant magnetostrictive rod 305 expands and contracts in proportion to the magnitude of the applied current. At this time, the displacement at both ends of the giant magnetostrictive rod 305 is determined by the rigidity of the two bias springs 317 and 318 that apply axial pressure to the giant magnetostrictive rod. When the strokes of the piston 302 and the seal shaft 311 are changed, the rigidity ratio of the two bias springs 317 and 318 may be changed as in the fourth embodiment.
[0152]
By utilizing this point, in the present embodiment, a single giant magnetostrictive actuator can have both discharge ON and discharge OFF functions.
[0153]
The seal shaft 311 extends through the cylindrical upper sleeve 312 and further upwards. Reference numeral 319 denotes a motor that gives a rotational motion to the seal shaft 311. In this embodiment, a DC servo motor is used, 320 is a motor rotor, 321 is a motor stator, and 322 is an upper housing that houses the motor stator.
[0154]
An encoder 323 for detecting the rotational speed of the seal shaft 311 is provided on the upper portion of the upper housing 322. Further, a displacement sensor 324 for detecting the position of the end surface of the central axis is disposed at the upper center position.
[0155]
A lower sleeve 316 that houses a part of the discharge side of the piston 302 is rotatably supported by a ball bearing 325 provided between the housing 304 and the lower sleeve 316.
[0156]
Reference numeral 326 denotes a connecting portion between the piston 302 and the seal shaft 311.
[0157]
327 is a suction port formed in the fixed sleeve 303, 328 is a nozzle portion, 329 is a discharge nozzle formed in the nozzle portion 328, and 330 pressure-feeds the fluid formed on the relative movement surface of the piston 302 and the fixed sleeve 303. It is a thread groove.
[0158]
The members 302 and 303 form a fluid transport chamber 331 that sucks fluid from outside and pumps it to the discharge side. In addition, a fluid constriction portion 332 having a narrower gap than other portions is formed between the discharge side end portion of the outer peripheral portion of the piston 302 and the inner surface of the fixed sleeve 303.
[0159]
The fluid restricting portion 332 need not be formed when the gap of the thread groove pump is narrow. Further, an internal space 333 is formed between the discharge-side end surface of the piston 302, its opposing surface, and the fixed sleeve 303, the volume of which changes as the piston 302 moves up and down.
[0160]
A discharge valve 334 whose discharge passage area can be varied by raising and lowering the seal shaft 311 is configured between the discharge-side end portion of the seal shaft 311 and its opposing surface.
[0161]
That is, the internal space 333 and the discharge valve 334 constitute a flow rate control unit 335 that turns ON and OFF the discharge flow rate at an arbitrary timing.
[0162]
Incidentally, the rotational motion given to the seal shaft 311 is given to the piston 302 by the connecting portion 326 of the piston 302 and the seal shaft 311 as shown in FIG. That is, the seal shaft 311 has a connecting portion shape (square cross section) that transmits only rotation to the piston 302 and is free of relative linear motion.
[0163]
With the above configuration, in the fluid supply device of this embodiment, the piston 302 and the seal shaft 311 can simultaneously and independently control the rotational movement and the linear movement of the minute displacement.
[0164]
Furthermore, in the embodiment, since the giant magnetostrictive element is used for the direct acting actuator 301, power for linearly moving the giant magnetostrictive rod 305 (and the piston 302 and the seal shaft 311) can be applied from the outside without contact. . That is, in the dispenser of this configuration, the discharge flow rate can be controlled with a high response by utilizing the characteristics of the electromagnetic strain element having a frequency characteristic of several megahertz while the motor is rotated.
[0165]
In the embodiment, the motor is arranged above the actuator 301 (superelectrostrictive element). However, the arrangement may be reversed.
[0166]
If the dispenser of a present Example is used, it can apply to the use similar to 4th Example (FIG. 20), without using an external pressure source. That is, it can be applied to the coating process as a “method of turning ON / OFF the discharge flow rate at an arbitrary timing”.
[0167]
Although the pressure level of the air pressure source installed in the production plant is limited, the maximum pressure of the thread groove pump of this embodiment can be freely selected by selecting parameters such as the rotation speed, clearance, and thread groove shape. Can be set. Factory piping pressure standard is 5kg / cm²On the other hand, in the thread groove pump, several tens to 100 kg / cm²It is also possible to obtain a pressure of As a result, the restriction on the pressure condition is released, and for example, a large flow rate can be discharged by a small diameter nozzle.
[0168]
If a thrust dynamic pressure seal 336 as shown in FIG. 24 is provided on the relative movement surface of the discharge-side end surface of the seal shaft 311 and its opposing surface by utilizing the fact that the seal shaft 311 can rotate, the discharge can be performed in a non-contact state. Can be cut off. The portion filled in black in the figure is the groove 337 of the spiral groove.
[0169]
In FIG. 24, curve (A) shows an example of the generated pressure characteristic with respect to the gap of the dynamic pressure seal.
[0170]
When the outer diameter of the dynamic pressure seal is small, the characteristic of the generated pressure (seal pressure) P with respect to the gap δ is non-linear, and when the gap → 0, the generated pressure rapidly increases. On the other hand, the generated pressure of the thread groove pump does not depend on the change of the gap δ. Therefore, in the example of FIG. 24, δ <δ₁When (≈2.5 μm), it can be seen that the ejection is blocked.
[0171]
FIG. 25 shows a model in which the discharge is blocked.
[0172]
The flow diameter of the powder 339 dispersed in the fluid 338 is set to df = 10 μm, for example, and the gap between the seal shaft 311 and the gap portion 340 on the opposite surface is set to δ = 2.5 μm, for example. Thus, even if δ <df, in this embodiment, the powder 339 is not mechanically compressed or broken. In the state of FIG. 25, the fluid in the gap 340 is always subjected to centrifugal force by the pumping action of the dynamic pressure seal 336, and the powder does not enter this portion from the outer periphery.
[0173]
On the other hand, even when the seal shaft 311 is still descending and the gap δ of the gap 340 is still large, the powder is not compressed or broken. The reason for this is that, as described in the third and fourth embodiments, when the seal shaft 311 reaches the lowermost end due to the steep increase in the volume of the closed space 333 and the pressure effect following it, the vicinity of the discharge valve 334. This is because there is no powder fluid already present.
[0174]
With the above embodiment, the following effects of the present invention
(1) High speed flow rate shut off and start
(2) Troubles such as clogging of the flow path due to squeezing powder and changes in fluid characteristics do not occur
That is, a coating process satisfying both of the above (1) and (2) can be realized.
[0175]
In the embodiment, in order to eliminate the powder fluid in the vicinity of the discharge valve, (1) a sudden volume change is given to the internal space, (2) the discharge valve is opened and closed, and the operations of the above (1) and (2) are reversed in phase. We used the actuator given in
[0176]
By utilizing the fact that this embodiment uses a servo motor, the present invention can also be applied by the following method.
[0177]
That is, even if the above (1) and (2) of (1) the flow rate control method by controlling the rotational speed of the motor and (2) the method of changing the volume of the closed space sharply using a high-speed actuator are combined, It is possible to realize flow rate control that makes use of the advantages and eliminates the disadvantages. In this case, either the seal shaft or the piston may omit the function of vertical movement. For example, in FIG. 22, it is assumed that the piston rotates only and does not move up and down, and only the seal shaft moves up and down. Since the seal shaft in this case plays a role in place of the piston of FIG. 22, the outer diameter may be set larger.
[0178]
For example, when the discharge is cut off
(1) The rotation of the motor 319 is stopped simultaneously with the start of raising the seal shaft 311. As described above, the discharge flow rate is cut off on the order of 0.01 seconds or less by the rise of the seal shaft 311. However, for example, it takes about 0.05 seconds to stop the rotation of the motor, but during that time, the seal shaft 311 is kept in a rising state.
[0179]
(2) When the motor 319 stops, the gentle reverse rotation is started immediately. The fluid retained in the vicinity of the flow rate control unit 335 flows backward toward the suction port 327 by the action of the thread groove pump. When the fluid near the flow rate control unit 335 disappears and is replaced with the air flowing in from the discharge nozzle 329, the seal shaft 311 is lowered to shield the opening of the discharge nozzle 329.
[0180]
Also, at the beginning of discharge,
(3) The rotation of the motor 319 is started in advance. It is confirmed from the encoder 323 signal that the rotational speed of the motor is in a steady state, and the seal shaft 311 is suddenly raised and suddenly stopped. If it stops suddenly, the discharge is started immediately.
[0181]
In addition, as a method not to cause crushing damage of powder,
(1) The pressure of the pressure supply source connected to the suction port is suddenly changed to a negative pressure.
[0182]
(2) The external negative pressure source and the flow rate controller are connected via a valve that opens and closes at high speed.
[0183]
In any of the above methods, the dynamic pressure seal can be configured with the discharge valve completely shielded or with a gap equal to or smaller than the flow diameter of the powder without causing the powder to be squeezed or broken.
[0184]
When a dynamic pressure seal is configured, a motor drive is necessary, but it is not necessary to use a motor when it is completely shielded.
[0185]
In the specification of the present invention, expressions such as a piston, a seal shaft, and a cylinder are associated with cylindrical and cylindrical members, but the scope of application of the present invention is not limited to these specific shapes. For example, the piston may have a thin plate shape such as a diaphragm. The discharge valve composed of the seal shaft and its opposing surface may be a combination of any shapes as long as it is a member capable of shielding, opening or changing the passage area.
[0186]
In the embodiment, the steep pressure change due to the volume change of the internal space is due to the squeeze pressure generated by changing the narrow gap of several microns to several hundred microns.
[0187]
The principle differs between this squeeze pressure and a pressure change caused by, for example, compressing or contracting a piston of an air cylinder.
[0188]
The latter depends on the compressibility of the fluid, and the change in pressure is accompanied by a time delay with respect to the change in volume.
[0189]
The reason why the responsiveness of the air pulse dispenser described above is limited is that it depends on the compressibility of the fluid.
[0190]
On the other hand, the former squeeze pressure is due to the dynamic pressure effect of the viscous fluid, and there is no time delay with respect to the volume change. That is, the pressure immediately increases or decreases with the change of the gap.
[0191]
In the embodiment, the flow rate control unit is configured by utilizing the fact that the pressure immediately increases and decreases in this way. Although the present invention can use compression / expansion of fluid, use of squeeze pressure is preferable in terms of responsiveness.
[0192]
Now, returning to the “method for turning ON / OFF the discharge flow rate within a limited time”, which is the first and second embodiments of the present invention, an embodiment that covers the drawbacks will be described. In the above-described embodiment, discharge is blocked by using a sharp pressure drop by giving a steep volume change to the closed space connected to the discharge passage. However, the time during which the discharge shielding is effective is only while the volume of the closed space is increasing.
[0193]
Therefore, the following two flow control means, that is,
(1) First flow rate control means: A method of increasing / decreasing the volume of the internal space, which is a high-speed response but has a finite shielding time.
[0194]
{Circle around (2)} Second flow rate control means ... Although the responsiveness is lower than that of the first flow rate control means, there is no restriction on the shielding time.
[0195]
That is, a combination of the above (1) and (2) can realize a dispenser that takes advantage of each of the advantages and eliminates the drawbacks.
[0196]
FIG. 26 shows a sixth embodiment in which the flow path switching valve 400 is used as the second flow rate control means, and this valve 400 is arranged in the middle part of the discharge nozzle.
[0197]
401 is a piston, 402 is a fixed sleeve, 403 is a housing, 404 is a discharge unit, 405 is a downstream discharge nozzle, 406 is a bypass passage, and 407 is a flow rate control unit including an internal space 408.
[0198]
In the above configuration, the allowable shielding time of the first flow rate control means is T₁And the rise time of the second flow rate control means is T₂And For example, in the specific specification of the first embodiment, assuming that the piston stroke is Xst = 50 μm and the piston lifting speed is v = 1.0 mm / sec, T₁= 0.05 seconds. If the flow path switching valve 400 is, for example, a DC servo motor or a swing motor, 0.03 <T₂<0.05 seconds.
Therefore, T₁> T₂Therefore, the application conditions of the present embodiment can be satisfied.
[0199]
(1) First, when the discharge is blocked, the piston 401 is lifted (first flow rate control means) and the flow path switching valve 400 is operated simultaneously. From the start of operation, discharge is blocked at t = 0.01 seconds or less. Further, at t = 0.03 to 0.05 seconds, the discharge passage connected to the atmosphere is blocked by the flow path switching valve 400. Thereafter, the fluid whose pressure has returned to high pressure flows out through the bypass passage.
[0200]
(2) At the start of discharge, the piston 401 is lowered to a predetermined position in advance. Since the response time of the flow path switching valve 400 is known, the discharge is started after the waiting time is predicted.
[0201]
As described above, in the description of the present invention, the embodiment is divided into two methods, “a method for turning ON / OFF the discharge flow rate at an arbitrary timing” and “a method for turning ON / OFF the discharge flow rate within a limited time”. Explained. However, the two may be used in combination. For example, it has a function of shutting off the flow rate by driving the seal shaft, but it may be a usage method in which the discharge shielding is further ensured by using the second flow rate control means.
[0202]
A seventh embodiment in which the present invention is applied to a multi-nozzle dispenser will be described below.
[0203]
Reference numeral 501 denotes a piston driven by a first actuator (not shown), 502 denotes a seal plate driven by a second actuator (not shown), 503 denotes a housing for housing these members, and 504 denotes an inside of the housing 503. A fluid transport chamber 506 formed in the communication port and communicated with the suction port (not shown) and the discharge port 505 is a fluid throttle portion.
[0204]
For example, when the discharge is blocked, the piston 501 and the seal plate 502 move in the direction of the arrow, and when the discharge is released, both move in the opposite direction. The operating principle of this dispenser is the same as in the third and fourth embodiments.
[0205]
The above embodiment is an example of “a method of turning ON / OFF the discharge flow rate at an arbitrary timing”. However, as shown in the first and second embodiments, “ON the discharge flow rate within a limited time, In the case of “method of turning off”, a multi-nozzle can be formed similarly.
[0206]
FIG. 28 shows an eighth embodiment of the present invention.
[0207]
In this embodiment, a thread groove pump is provided on the upper side of the flow path of the dispenser of the present invention for the purpose of securing the supply pressure of the suction side fluid and reducing the viscosity.
[0208]
When a rheological fluid is used as the carrier fluid, the viscosity of the fluid is determined by the temperature and the shear rate that the fluid undergoes. This example utilizes the fact that the fluid once reduced in viscosity normally requires a certain amount of time to recover to the original viscosity due to the thixotropic fluid behavior of the rheological fluid. That is, at the stage immediately before supplying the fluid to the microminiature dispenser of the present invention, the fluid is first subjected to a shearing action by the rotation of the thread groove pump to lower the viscosity of the fluid.
[0209]
Since a single thread groove pump with a large outer diameter is sufficient for a plurality of ultra-small dispensers, there is no problem in the arrangement of the fluid supply system that is made into a multi-nozzle.
[0210]
A thread groove pump 600 is a master pump, and includes a rotation shaft 601, a motor rotor 602, a motor stator 603, a thread groove 604 formed in the rotation shaft 601, a suction port 605, a discharge port 606, and a housing 607.
[0211]
Reference numeral 608 denotes a small dispenser which is a fluid supply apparatus of the present invention, and the thread groove pump 600 and the small dispenser 608 communicate with each other via a supply pipe 609.
[0212]
If a fluid supply system is configured by arranging a plurality of small dispensers (first to sixth embodiments) according to the present invention in parallel, it can be applied to a process of applying a phosphor material or the like on a flat plate, for example. In this case, the suction side discharge passage for the coating material may be common.
[0213]
Since the dispenser (and ON / OFF) of each nozzle can be controlled individually, it is possible to apply a flat plate surface with a high degree of freedom and a small loss of coating material.
[0214]
Or if it comprises so that the content of several dispenser may be accommodated in a common housing, the coating device which has the multi-nozzle of a simpler structure will be made (not shown).
[0215]
【The invention's effect】
The following effects can be obtained by the fluid rotating device using the present invention.
1. High-speed discharge can be shut off and started.
2. Troubles such as clogging of the flow path due to squeezing powder and changes in fluid characteristics do not occur.
3. Multi-nozzle is easy because of simple structure.
4). Further, the pump of the present invention can have the following characteristics.
[0216]
(1) A high-viscosity fluid can be applied at high speed.
[0217]
(2) A very small amount can be discharged with high accuracy.
[0218]
If the present invention is used for, for example, a surface mount dispenser, a phosphor coating for a PDP or a CRT display, a sealing material coating for a liquid crystal panel, etc., the advantages can be fully exhibited, and the effect is enormous.
[Brief description of the drawings]
FIG. 1 is a front sectional view showing a dispenser according to a first embodiment of the present invention.
FIG. 2 is an enlarged cross-sectional view of a discharge unit according to the embodiment.
FIG. 3 is a view showing a discharge shielding process of the embodiment.
FIG. 4 is a diagram showing a discharge shielding process of the embodiment.
FIG. 5 is a diagram showing a discharge shielding process of the embodiment.
FIG. 6 is a diagram showing an analysis result showing a flow rate characteristic of the embodiment.
FIG. 7 is an electric circuit model diagram of the above embodiment.
FIG. 8 is a diagram showing an application target of the above embodiment.
FIG. 9 is a diagram showing the timing of the start of application in the above embodiment.
FIG. 10 is a diagram showing the relationship between piston position and time in the embodiment.
FIG. 11 is a front sectional view showing a dispenser according to a second embodiment of the present invention.
FIG. 12 is a front sectional view showing a dispenser according to a third embodiment of the present invention.
FIG. 13 is a diagram showing a discharge shielding process of the embodiment.
FIG. 14 is a view showing a discharge shielding process of the embodiment.
FIG. 15 is a view showing a discharge shielding process of the embodiment.
FIG. 16 is a diagram showing an analysis result showing the flow rate characteristics of the above example.
FIG. 17 is a diagram showing a flow velocity vector analysis result of the above embodiment.
FIG. 18 is a diagram showing a flow velocity vector analysis result of the above example.
FIG. 19 is a diagram showing the relationship between stroke and time in the above embodiment.
FIG. 20 is a front sectional view showing a dispenser according to a fourth embodiment of the present invention.
FIG. 21 is a diagram showing a discharge shielding process of the embodiment.
FIG. 22 is a front sectional view showing a dispenser according to a fifth embodiment of the present invention.
FIG. 23 is a view showing a connecting portion of the embodiment.
FIG. 24 is a diagram showing the relationship between the generated pressure and the clearance of the dynamic pressure seal of the above embodiment.
FIG. 25 is a model diagram of the seal shaft tip of the above embodiment.
FIG. 26 is an enlarged view of the discharge section according to the sixth embodiment of the present invention.
FIG. 27 shows a dispenser according to a seventh embodiment of the present invention.
(I) is a perspective view
(B) shows the nozzle
FIG. 28 is a model diagram of an eighth embodiment of the present invention.
FIG. 29 is a view showing a conventional air pulse dispenser.
[Explanation of symbols]
1 Actuator
2 piston
3 cylinders
20 Fluid transport chamber
27 Internal space
17 Suction hole
19 Discharge hole

Claims (4)

  In a fluid supply method for supplying powdered fluid to a space formed by a housing and a sleeve provided outside the piston and fixed to the housing, and discharging the powdered fluid from a discharge nozzle, a discharge side end surface of the sleeve; The relationship between δs and D is D> δs, where δs is the clearance with the facing surface, and D is the clearance in the radial direction of the piston in the space formed by the housing and the sleeve, and A fluid supply method characterized by controlling shut-off and release of powdered fluid discharged from a discharge nozzle by moving a piston in an axial direction without contact with the housing.   When the particle size of the powder fluid is d, and the gap between the piston and its opposing surface is Xmin, the relationship between δs and d is δs> d, and Xmin is changed by Xmin> d. The fluid supply method according to claim 1.   In a fluid supply method for supplying powdered fluid to a space formed by a piston and a housing and discharging the powdered fluid from a discharge nozzle, a gap in a radial direction of the piston is formed in a space formed by the piston and the housing. A squeezed portion formed by an outer peripheral surface of the piston and an inner peripheral surface of the housing, and a powder fluid discharged from a discharge nozzle by axially moving the piston in a non-contact manner with respect to the housing. A fluid supply method characterized by controlling shut-off and opening.   The relationship between L and d is L> d, where L is the interval in the radial direction of the piston in the throttle part, d is the particle size of the powdered fluid, and Xmin is the gap between the piston and its facing surface. The fluid supply method according to claim 3, wherein Xmin is changed by Xmin> d.

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