JP2005040807A

JP2005040807A - Injection device of low melting-point metal

Info

Publication number: JP2005040807A
Application number: JP2003201007A
Authority: JP
Inventors: Norihiro Koda; 紀泰甲田; Mamoru Miyagawa; 守宮川
Original assignee: Nissei Plastic Industrial Co Ltd
Current assignee: Nissei Plastic Industrial Co Ltd
Priority date: 2003-07-24
Filing date: 2003-07-24
Publication date: 2005-02-17
Anticipated expiration: 2023-07-24
Also published as: JP3848937B2

Abstract

<P>PROBLEM TO BE SOLVED: To provide an injection device of low melting-point metal to store/suck and meter melt, which is capable of easily controlling the temperature from storing and holding the melt to the injection and filling the melt after suction and metering by erecting a melt heat-retaining and storage cylinder 2 on an upper portion of a melt holding chamber of an injection heating cylinder, and horizontally installing the cylinder on a base to realize direct nozzle touch on a die. <P>SOLUTION: A melt heat-retaining and storage cylinder 2 is erected on an upper portion of a melt holding chamber 14 of a horizontal injection heating cylinder 1 having a metering chamber 13 communicating with a nozzle port on a tip part. A heating cylinder 3 having an insertion part of a bar-like material 4 on one end part thereof is horizontally and longitudinally connected to an upper side part of the heat-retaining and storage cylinder 2. The melt of low melting-point metal melted by the heating cylinder 3 is stored in the heat-retaining chamber. The melt in the heat-retaining and storage chamber is automatically fed to the melt holding chamber 14 by the injection of an injection plunger 16 in the metering chamber 13. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
この発明は、亜鉛、マグネシウム又はそれら合金等の低融点金属材料の溶体を、射出プランジャにより金型に射出充填して金属製品に成形する射出装置に関するものである。
【０００２】
【従来の技術】
従来の低融点金属材料の射出装置では、注湯ピストンを内装した水平な注湯シリンダの上部に、スクリュ内装の押出シリンダを並設し、その押出シリンダの先端と注湯シリンダの先端部とを、弁室を備えた湯路により連通して、押出シリンダにより溶融した金属材料を湯路から注湯ピストンヘッド室に送り込んだ後、注湯ピストンを前進移動して溶湯をノズルから金型に射出充填している（例えば、特許文献１参照）。
【０００３】
またノズル口と連通した計量室を先端部に有し、中程上側に供給口を有する筒体内に射出ロッドを備え、射出ロッド先端の射出プランジャを計量室内に進退自在に設けた溶解筒を、型締機構に対し下向きに傾斜し、射出プランジャの後退移動により溶解筒内の溶湯を吸引計量した後、射出プランジャの前進移動により計量した溶湯を金型に射出充填するものもある（例えば、特許文献２参照）。
【０００４】
また加熱スリーブと周囲の加熱手段とからなる材料成形供給装置を、水平な射出機構の上部に並設し、その材料成形供給装置によりアルミニウムのビレットを半溶融状態にして整形ビレットに裁断したのち、その整形ビレットを射出機構内のプランジャ前面に落下供給して、整形ビレットをプランジャの前進移動により金型に射出充填するものもある（例えば、特許文献３参照）。
【０００５】
【特許文献１】
特開平１１−２５４１１９号公報（第３−５頁、図１）。
【特許文献２】
特開２００１−１９１１６８公報（第３−４頁、図１）。
【特許文献３】
特開２００１−１９１１６２号公報（第３−５頁、図１）。
【０００６】
【発明が解決しようとする課題】
注湯シリンダ上部の押出シリンダにより材料溶融を行い、溶湯を湯路から注湯ピストンヘッド室に送り込んで、注湯ピストンにより金型に射出充填する特許文献１に記載の成形機では、射出成形ごとに溶湯を注湯ピストンヘッド室に搬送し、その溶湯により注湯ピストンを後退して計量を行うため、成形の都度、材料溶融と溶湯の供給を同時に行わねばならず、また搬送量は１ショット分に制限されることと、湯路内にバルブを備えることなどから、溶融から射出に至るまでの溶湯の温度を、外部の加熱手段により一定に保持することが難しく、肉厚が１．５ｍｍ以下の金属製品では、温度むらが原因とされる成形不良が生じ易い。
【０００７】
構造においても湯路を溶湯の圧力で開閉するバルブを不可欠し、そのバルブも溶湯の射出圧力で閉作動するので湯路の閉鎖にばらつきが生じ易く、計量が不安定となる等の課題をも有する。
【０００８】
また材料溶融にスクリュを採用していることから、金属材料はチップ等の粒状材料に制限され、同一質量の材料全体における表面積が粒状よりも小さく、酸化物の発生が少ないとされている短柱状、丸棒状等の棒状材料を使用することができない。この使用材料の課題は上記特許文献２に記載されている材料整形供給装置を採用することにより解決されるが、この場合でも、整形材料は１ショット分ずつ射出プランジャの前に供給しているので、溶湯の温度管理の改善までには至らない。
【０００９】
特許文献３に記載の成形機では、溶解筒により溶解した材料を、そのまま多量の溶湯として先端部に貯留し、その溶湯の一部を射出成形ごとに貯留部先端の計量室に、射出プランジャの強制後退をもって吸引計量しているので、温度制御は射出プランジャの後に貯留された多量の溶湯を対象に行われることになる。このため１ショット分の僅かな量の溶湯を対象とする場合よりも温度制御は容易となり、安定した温度管理の下に温度むらのない射出成形が行えるようになる。
【００１０】
しかし、溶湯貯留・吸引計量式の射出装置では、多量の溶湯を貯留するために溶解筒を型締装置に対して傾斜設置することを不可欠とし、このため金型へのノズルタッチが直接行えず、ノズルタッチはノズルタッチブロックを介した間接的なものとなる。また傾斜によって機械高さが水平設置による場合よりも高くなり、これらが大型化する際の課題となっている。
【００１１】
この発明は、上記従来技術の課題を解決するために考えられたものであって、その目的は、溶体を貯留・吸引計量する射出装置であっても、機台上に水平に設置して金型に直接ノズルタッチすることができ、また材料溶融後の溶体の貯留及び保持から吸引計量後の射出充填に至るまでの温度保持が温度むらなく行え、構造もこれまでよりも簡素化されて大型化も可能な新たな低融点金属材料の射出装置を提供すことにある。
【００１２】
【課題を解決するための手段】
上記目的によるこの発明は、ノズル口と連通した計量室を先端部に有し、その計量室と連続した内部を上部開口の溶体保持室に形成した水平な射出加熱筒と、先端の射出プランジャを計量室に進退自在に挿入して射出加熱筒内に設けた射出ロッドと、その射出ロッドの後端を連結した射出加熱筒後部の射出駆動装置とからなり、上記射出プランジャの強制後退により溶体保持室の溶体を計量室に吸引計量する低融点金属材料の射出装置であって、上記射出加熱筒の溶体保持室の上部に溶体の保温貯留筒を立設し、その保温貯留筒の上側部に、棒状材料の挿入部を一端部上に備える加熱筒を横長に接続し、その加熱筒により溶融した低融点金属材料の溶体を保温貯留筒内の保温貯室に貯留して、上記射出プランジャの射出動作により保温貯室の溶体を溶体保持室に自動的に給送可能に構成してなる、というものである。
【００１３】
また上記計量室と溶体保持室の面積比は１：１〜１：２からなるというものであり、上記射出ロッドの溶体保持室に位置する部分は、複数の環状段部による攪拌部に形成されている、というものである。
【００１４】
さらに、上記保温貯留筒は、保温貯室の上部にアルゴンガス等の不活性ガスパイプを具備し、または不活性ガスパイプはガス噴出口の位置が上下に異なる複数本の不活性ガスパイプからなり、その不活性ガスパイプの圧力差から溶体貯留量の増減を検出する手段を有する、というものである。
【００１５】
【発明の実施の形態】
図中１は射出加熱筒、２は溶体Ｍ（液相状態、半溶融状態の何れをも含む）の保温貯留筒、３は棒状材料４の加熱筒で、それらの外周囲には加熱温度を個々に制御できるヒータ５が設けてある。６は加熱筒３の一端部上に設けた棒状材料４の供給装置、７は油圧作動の射出駆動装置、８は金型９を備えた機台１０上の型締装置で、この型締装置８に対して射出加熱筒１が射出駆動装置７と共に機台１０上に水平に設置してある。
【００１６】
上記射出加熱筒１は、筒体１１の先端に部材１１ａをもって取付けたノズル部材１２を備え、そのノズル部材１２のノズル孔と連通する後部内は、所要長さの計量室１３に形成してある。この計量室１３と連続した射出加熱筒１の内部は、後部上が開口した横長の溶体保持室１４となっている。この溶体保持室１４の面積は計量室１３の面積を基準として設定される。これは両室の直径に差があり過ぎると、溶体保持室側の面積全体に吸引が生じ難くなって、室内周囲の吸引が及ばない所に長く滞留する溶体が生じ、それが金属製品に取って好ましくない金属間化合物となって混在するおそれがあるからである。したがって、計量室１３と溶体保持室１４の面積比は、滞留が生じない面積比１：１〜１：２とするのが好ましく、容量は計量室１３の容量の１０倍前後が好ましい。
【００１７】
また射出加熱筒１の中央には、筒体１１の後端から挿入した射出ロッド１５が、先端の射出プランジャ１６を計量室１３に進退自在に挿入して設けてある。この射出ロッド１５の後端は、筒体後端に連結した支持体１７から外部に突出し、その支持体１７と共に機台１０上のガイドバー１８に摺動自在に挿通した上記射出駆動装置７のピストンロツド７１に連結してある。また射出ロッド１５の溶体保持室１４に位置する部分は、複数の環状段部による攪拌部１５ａに形成してある。なお、支持体１７は筒体後端に連結した射出加熱筒１の円筒形の後部部材１７ａと、脚部を上記ガイドバー１８に挿通して機台上に立設した支持盤１７ｂとからなる。
【００１８】
上記射出プランジャ１６は、図ではその詳細は省略するが、外周囲にリングバルブを備えたものからなり、そのリングバルブにより、計量室１３の内壁面と射出プランジャ１６の外側面との間形成した吸引クリアランスを開閉して、図２に示す溶体保持室１４の溶体Ｍ１の吸引計量と、計量室の溶体Ｍ２の金型９への射出充填が行い得る構造からなる。
【００１９】
上記保温貯留筒２は、溶体保持室１４の上部開口１４ａ（図２、３参照）と内径が同径の筒体２１と、その筒体２１の上端に取付けた中空の上部部材２２とからなり、その上部部材２２の後側面に上記加熱筒３の内径と同径の連通孔２３が穿設してある。この上部部材２２の連通孔２３の穿設部位には、上記加熱筒３が先端面を当接して水平に取付けてある。また筒体２１の側部には温度検出端子２５が設けてあり、上部部材２２の内部にはアルゴンガス等の２本の不活性ガスパイプ２６ａ，２６ｂが、ガス噴出口の位置に上下差を持たせて天井面から垂直に設けてある。
【００２０】
このような保温貯留筒２は、筒体２１の下端を溶体保持室１４の上部開口１４ａの周囲に嵌合して、射出加熱筒１の上部に垂直に立設され、それにより筒体内が溶体保持室１４と底部で通じた保温貯室２４となって、上記射出プランジャ１６の射出動作ごとに、保温貯室２４から溶体保持室１４に常に一定量の溶体Ｍ１が自動的に給送される。この保温貯室２４の容量は上記計量室１３の容量の１０倍前後が好ましい。
【００２１】
上記加熱筒３は、通常寸法の棒状材料４（例えば、マグネシウム合金、長さ３００ｍｍ、直径６０ｍｍ）の２本を収容できる長さと内径とからなり、その後半部は樋状に形成されて上方から棒状材料４を長手方向に収容できるようにしてある。また前半部の筒体周囲には予備加熱用の第１ヒータ５ａと溶融用の第２ヒータ５ｂとが前後２段に分けて取付けてあり、これにより棒状材料４の予備加熱と溶融又は半溶融を連続して行えるようにしてある。
【００２２】
上記加熱筒３の後半部は、射出加熱筒１の上方に設けた支持ブロック２０の前後方向の横溝内に挿通支持され、これにより加熱筒３の熱膨張による伸縮が自由に行えるようにしてある。支持ブロック２０は上記支持盤１７ｂの上面両側に止着した部材１９に載置固定してある。
【００２３】
上記支持ブロック２０の上部には、一対の側面板６１が横溝を隔てて対設してあり、その側面板６１の間に複数本の棒状材料４を横に寝かせて縦にストックできるようにしてある。また支持ブロック２０の片側面の上部には、横溝の上部内に出没自在に横設した前後一対の材料受けピン６２のエアシリンダ６３が取付けてある。
【００２４】
支持ブロック２０の下側には、押込エアシリンダ６４がブラケット６５により支持して加熱筒３と並行に後ろ向きに取付けてある。この押込エアシリンダ６４の後端から水平に伸縮するピストンロッド６６には、加熱筒３内に挿入される材料押込ロッド６７が、外端を継板により連結して上下並行に取付けあり、これにより上記側面板６１の間から加熱筒３の後半部内に落ち込んだ棒状材料４の供給装置６を構成している。
【００２５】
上記構成の射出装置では、支持ブロック２０の横溝内に溝壁から材料受けピン６２を突出した状態において、上記側面板６１の間に棒状材料４を重ねて収容することができ、押込エアシリンダ６４による材料受けピン６２の引き込みにより、最下位の棒状材料４が加熱筒３の後半部内に落ち込むようになる。その後に材料受けピン６２をエアシリンダ６３により突き出すと、加熱筒内の棒状材料４とその上の棒状材料４との間に材料受けピン６２が入り込んで、側面板６１間の棒状材料４を受け止める。
【００２６】
この材料受けピン６２の引き込み作動は、上記押込エアシリンダ６４のピストンロッド６６の縮小作動により、押込ロッド６７が後半部内の棒状材料４を前半部内に完全に押し込んだ位置に達したときに、図では省略するが、その位置に予め設定したリミットスイッチによりエアシリンダ６３が作動して行われる。
【００２７】
材料受けピン６２が引き込んだときには、押込ロッド６７のヘッドが加熱筒内にあるので、最下位の棒状材料４はヘッドが後半部外に抜け出たときに完全に収まり、またその位置で他のリミットスイッチがエアシリンダ６３を作動して材料受けピン６２の突出による受け止めが行われる。したがって、後半部内への棒状材料４の供給は、材料押込みとの関連において行われるようになる。
【００２８】
加熱筒３の前半部内への材料押込みは、先端部内の棒状材料４の溶融状態に合わせて行われる。前半部内に押し込まれた棒状材料４は、先ず低温（例えば、３００℃）設定された第１ヒータ５ａにより予熱され、その後に高温（例えば、６１０°〜６２０℃）に設定された第２ヒータ５ｂにより溶融して、連通孔２３から所定温度に保たれた保温貯留筒２に流入し、上記溶体保持室１４を底部とする保温貯室２４に溶体Ｍとして、連通孔２３の下側まで貯留される。保温貯室２４は上記不活性ガスパイプ２６ａ，２６ｂから室内に噴出されたアルゴンガスにより、常に不活性ガス雰囲気に維持され、貯留された溶体Ｍの酸化を防止している。
【００２９】
この保温貯室２４における溶体Ｍの貯留量は、成形される金属製品の質量によって異なるが、溶体Ｍを長時間にわたり貯留すると金属間化合物が生成されるおそれがあるので、１０ショット前後の分量を貯留するのが好ましい。この貯留量の増減は、ガス噴出口の位置に高低差を付けて保温貯室２４の上部内に垂設した２本の不活性ガスパイプ２６ａ，２６ｂにおける圧力差から検出している。
【００３０】
この検出手段は既に実施されているものであって、両不活性ガスパイプ２６ａ，２６ｂのガス噴出口間に溶体Ｍの液面が位置して、溶体中に長い方の不活性ガスパイプ２６ａのガス噴出口が没し、ガスの噴出抵抗の差から両ガスパイプに圧力差が生じているときを適正量としている。
【００３１】
これに対して、溶体Ｍの液面上昇により両方のガス噴出口が溶体中に没し、不活性ガスパイプ２６ｂの圧力が上昇して、両ガスパイプに圧力差が無くなると満タンとして検出し、それにより上記押込エアシリンダ６３が作動停止となって材料送込みが中止される。加熱筒３の前半部内の材料先端は溶融を続けるが、その量は僅かでその殆どが先端部内に留まる。この供給停止の射出成形の継続によって、液面が低下して不活性ガスパイプ２６ｂの圧力が元に戻り、再び圧力差が生ずるようになると、満タン解除として検出され、再度押込エアシリンダ６３が作動して棒状材料４の押込みが開始される。
【００３２】
また溶体Ｍの液面が降下して両方のガス噴出口が気中に露出し、不活性ガスパイプ２６ｂの圧力が低下して、両ガスパイプに圧力差が無くなると溶体不足として検出し、警告を発して材料の溶融供給が促進される。このように供給装置６の作動制御を行って、溶体Ｍの貯量を常に適正量に制御する。
【００３３】
上記溶体貯室２４における溶体Ｍの保持温度は、低融点金属材料によって異なり、溶融状態によっても異なる。例えば、マグネシウム合金でも樹枝状組織を有する材料で、上記加熱筒３により液相状態に溶融された溶体Ｍの場合には、その温度を保持して貯留する必要性から、保温貯留筒２の温度は液相線温度以上（例えば、６２０℃）に設定される。また球状の結晶組織を有する材料で、加熱筒３によりチクソトロピ性状を呈する状態に半溶融された溶体Ｍの場合には、保温貯留筒２の温度は溶体Ｍが液相線温度と固相線温度の間の温度に保つ温度（例えば、６００℃）に設定される。このような温度設定は、保温貯室２４に続く上記溶体保持室１４、計量室１３にても、外部に備えるヒータ５により同様に行われる。但し、溶体保持室１４の後端部は溶体漏出防止のために、他の部位よりも低温（例えば、５６０℃前後）に設定している。
【００３４】
保温貯室２４の溶体Ｍは、底部の溶体保持室１４に上部開口１４ａからそのまま流入して、射出加熱筒１内に溶体Ｍ１として所定量が保持される。この溶体Ｍ１は、上記射出ロッド１５の射出作動後の強制後退により、計量室１３の前進限に位置した射出プランジャ１６が、計量室１３を後退限位置まで移動する間、ノズル口の閉栓によって生ずる負圧により、リングバルブが開作動した上記吸引クリアランスから計量室内に吸引されてゆく。また吸引に伴い溶体保持室１４には溶体貯室２４から同量の溶体Ｍが流れ込む。
【００３５】
計量室１３に吸引計量された溶体Ｍ２は、上記射出ロッド１５の前進移動により計量室内を前進移動する射出プランジャ１６によって、ノズル口から型閉した金型９の図示しないキャビティに射出充填され、冷却により所望の金属製品に成形される。この際、吸引クリアランスは溶体Ｍ２の圧縮抵抗により後退作動するリングバルブにより閉鎖され、吸引クリアランスからの溶体Ｍ２の逆流が防止される。
【００３６】
したがって、計量室内を進退移動する射出プランジャ１６が、溶体貯室２４に貯留した溶体Ｍを、溶体保持室１４の溶体Ｍ１、計量室１３の溶体Ｍ２として順に送込むポンプを兼ねることになるので、他に溶体の移送手段は不要となり、射出プランジャ１６が溶体Ｍ１と接する長さも短くなるので、成形機全体における温度管理も容易となって、溶体の温度むらによる不良成形が減少する。
【００３７】
また溶体保持室１４の溶体Ｍ１は、射出ロッド１５が備える環状段部の攪拌部１５ａにより、射出ロッド１５が進退移動するごとに軸方向に攪拌されるので、溶体保持室１４におけるスラッジの沈下堆積が防止され、これが計量室１３との対比から面積を制限して溶体Ｍ２の部分的な滞留を防止した溶体保持室１４と相俟って、その効果を一層顕著なものとなす。
【００３８】
また射出加熱筒１の溶体保持室１４の上部に、保温貯留筒２を立設したことによって、貯留した溶体Ｍを吸引計量後に射出充填する射出装置であっても、保温貯留筒２によって溶体Ｍの深さを充分に確保できるので、溶融時に起こりがちな空気の取込みが防止でき、また溶体貯室２４にて溶体中のガスの逃出も自然に行われるので、これまでのように射出加熱筒１を型締装置８に対して傾斜設置する必要がなくなる。これにより射出加熱筒１を機台上に水平に設置して金型に直接ノズルタッチすることができることから、ノズルタッチブロックや傾斜支持部材などが不要となり、傾斜設置と比べて機械高さも低くなるので、溶体の貯留・吸引計量を採用した射出装置の大型化も可能となる。
【図面の簡単な説明】
【図１】この発明に係わる低融点金属材料の射出装置の縦断側面図である。
【図２】同上の装置前部の縦断側面図である。
【図３】同上の保温貯留筒部位の縦断正面図である。
【符号の説明】
１射出装置
２保温貯留筒
３加熱筒
４棒状材料
５ヒータ
６供給装置
７射出駆動装置
８型締装置
９金型
１０機台
１１射出装置の筒体
１２ノズル部材
１３計量室
１４溶体保持室
１４ａ開口部
１５射出ロッド
１５ａ攪拌部
１６射出プランジャ
１７支持体
２１保温貯留筒の筒体
２２保温貯留筒の上部部材
２４保温貯室
２６ａ，２６ｂ不活性ガスパイプ
６４押込エアシリンダ
６７押込ロッド[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an injection apparatus for forming a metal product by injecting and filling a metal melt of a low melting point metal material such as zinc, magnesium, or an alloy thereof into a mold with an injection plunger.
[0002]
[Prior art]
In a conventional low melting point metal material injection device, a screw-injection extrusion cylinder is arranged in parallel on the top of a horizontal pouring cylinder with a pouring piston, and the tip of the extrusion cylinder and the tip of the pouring cylinder are connected to each other. The metal material melted by the extrusion cylinder is fed into the pouring piston head chamber through the hot water channel provided with the valve chamber, and then the pouring piston is moved forward to inject the molten metal from the nozzle to the mold. It is filled (see, for example, Patent Document 1).
[0003]
In addition, a melting cylinder having a measuring chamber in communication with the nozzle port at the tip, an injection rod in the cylinder having a supply port in the middle, and an injection plunger at the tip of the injection rod provided in the measuring chamber so as to freely advance and retract, There is also a type that tilts downward with respect to the mold clamping mechanism, sucks and measures the molten metal in the melting cylinder by the backward movement of the injection plunger, and then injects and fills the molten metal measured by the forward movement of the injection plunger into the mold (for example, patents) Reference 2).
[0004]
In addition, a material molding and feeding device composed of a heating sleeve and surrounding heating means is juxtaposed on top of a horizontal injection mechanism, and after the aluminum billet is made into a semi-molten state by the material molding and feeding device, it is cut into a shaped billet. In some cases, the shaping billet is dropped and supplied to the front surface of the plunger in the injection mechanism, and the shaping billet is injected and filled into the mold by the forward movement of the plunger (for example, see Patent Document 3).
[0005]
[Patent Document 1]
JP-A-11-254119 (page 3-5, FIG. 1).
[Patent Document 2]
JP 2001-191168 (page 3-4, FIG. 1).
[Patent Document 3]
JP 2001-191162 A (page 3-5, FIG. 1).
[0006]
[Problems to be solved by the invention]
In the molding machine described in Patent Document 1, the material is melted by the extrusion cylinder at the top of the pouring cylinder, the molten metal is sent from the hot water passage to the pouring piston head chamber, and the mold is injected and filled into the mold by the pouring piston. Since the molten metal is transported to the pouring piston head chamber and the pouring piston is moved backward by the molten metal for measurement, the material must be melted and the molten metal supplied simultaneously for each molding, and the transport amount is one shot. It is difficult to keep the temperature of the molten metal from melting to injection constant by an external heating means because it is limited in minutes and a valve is provided in the hot water channel, and the wall thickness is 1.5 mm. In the following metal products, molding defects caused by temperature unevenness are likely to occur.
[0007]
Even in the structure, a valve that opens and closes the runner with the pressure of the molten metal is indispensable, and the valve also closes with the injection pressure of the molten metal. Have.
[0008]
Also, since screws are used to melt the material, the metal material is limited to granular materials such as chips, and the surface area of the entire material with the same mass is smaller than the granular material, and the short columnar shape is said to generate less oxide In addition, rod-shaped materials such as round bars cannot be used. The problem of this material used can be solved by adopting the material shaping supply device described in the above-mentioned Patent Document 2, but even in this case, the shaping material is supplied one shot at a time before the injection plunger. It does not lead to the improvement of temperature control of the molten metal.
[0009]
In the molding machine described in Patent Document 3, the material melted by the melting cylinder is stored as it is as a large amount of molten metal in the tip portion, and a part of the molten metal is stored in the measuring chamber at the distal end of the storage portion for each injection molding. Since suction metering is performed with forced retraction, temperature control is performed on a large amount of molten metal stored after the injection plunger. For this reason, temperature control becomes easier than in the case where a small amount of molten metal for one shot is targeted, and injection molding without temperature unevenness can be performed under stable temperature control.
[0010]
However, in the molten metal storage / suction metering type injection device, in order to store a large amount of molten metal, it is indispensable to install the melting cylinder at an inclination with respect to the mold clamping device, so that the nozzle touch to the mold cannot be performed directly. The nozzle touch is indirect via the nozzle touch block. In addition, the machine height becomes higher due to the inclination than in the case of horizontal installation, which is a problem in increasing the size.
[0011]
The present invention has been conceived in order to solve the above-mentioned problems of the prior art, and its purpose is to install it horizontally on a machine base even if it is an injection device for storing and sucking a solution. The nozzle can be directly touched to the mold, and the temperature can be maintained evenly from the storage and holding of the solution after melting the material to the injection filling after the suction metering, and the structure is simplified and large-sized than before. It is an object to provide a new low-melting-point metal material injection apparatus that can be made into a metal.
[0012]
[Means for Solving the Problems]
According to the above-mentioned object, the present invention has a horizontal injection heating cylinder having a measuring chamber communicating with the nozzle port at the tip, and forming a continuous portion of the measuring chamber in the solution holding chamber of the upper opening, and an injection plunger at the tip. It consists of an injection rod that is inserted into the measuring chamber so that it can move forward and backward, and is provided in the injection heating cylinder, and an injection drive device at the rear of the injection heating cylinder that connects the rear end of the injection rod. A low-melting-point metal material injection device that sucks and measures the solution in the chamber into the measurement chamber, and a solution heat storage cylinder is erected on the upper part of the solution holding chamber of the injection heating cylinder, and an upper portion of the heat storage cylinder A heating cylinder provided with a rod-shaped material insertion part on one end thereof is connected horizontally, and a melt of the low melting point metal material melted by the heating cylinder is stored in a heat insulation storage chamber in the heat insulation storage cylinder, Insulation chamber Body automatically formed by feedable configured to solution holding chamber, is that.
[0013]
The area ratio of the measuring chamber to the solution holding chamber is 1: 1 to 1: 2, and the portion of the injection rod located in the solution holding chamber is formed in a stirring portion by a plurality of annular step portions. It is that.
[0014]
Further, the heat insulation storage cylinder is provided with an inert gas pipe such as argon gas in the upper part of the heat insulation storage chamber, or the inert gas pipe is composed of a plurality of inert gas pipes whose gas outlets are vertically different. It has means for detecting an increase or decrease in the amount of stored solution from the pressure difference of the active gas pipe.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
In the figure, 1 is an injection heating cylinder, 2 is a heat retaining cylinder of a solution M (including both liquid phase and semi-molten state), 3 is a heating cylinder of a rod-like material 4, and the heating temperature is set around the outer periphery thereof. Heaters 5 that can be individually controlled are provided. 6 is a supply device for the rod-like material 4 provided on one end of the heating cylinder 3, 7 is a hydraulically operated injection drive device, and 8 is a mold clamping device on a machine base 10 having a mold 9. This mold clamping device 8, the injection heating cylinder 1 is installed horizontally on the machine base 10 together with the injection driving device 7.
[0016]
The injection heating cylinder 1 includes a nozzle member 12 attached to the tip of a cylinder 11 with a member 11a, and a rear portion communicating with the nozzle hole of the nozzle member 12 is formed in a measuring chamber 13 having a required length. . The inside of the injection heating cylinder 1 that is continuous with the measuring chamber 13 is a horizontally long solution holding chamber 14 that is open on the rear part. The area of the solution holding chamber 14 is set based on the area of the measuring chamber 13. If there is too much difference between the diameters of the two chambers, it will be difficult for suction to occur in the entire area on the side of the solution holding chamber, resulting in a solution that stays in a place where suction around the room does not reach, which is taken up by the metal product. This is because an undesirable intermetallic compound may be mixed. Therefore, the area ratio between the measurement chamber 13 and the solution holding chamber 14 is preferably an area ratio of 1: 1 to 1: 2 where no retention occurs, and the capacity is preferably about 10 times the capacity of the measurement chamber 13.
[0017]
An injection rod 15 inserted from the rear end of the cylinder 11 is provided at the center of the injection heating cylinder 1 by inserting an injection plunger 16 at the front end thereof into the measuring chamber 13 so as to freely advance and retract. The rear end of the injection rod 15 protrudes from a support body 17 connected to the rear end of the cylindrical body, and is slidably inserted into the guide bar 18 on the machine base 10 together with the support body 17. It is connected to the piston rod 71. Further, a portion of the injection rod 15 located in the solution holding chamber 14 is formed in a stirring portion 15a having a plurality of annular step portions. The support body 17 includes a cylindrical rear member 17a of the injection heating cylinder 1 connected to the rear end of the cylinder body, and a support board 17b that is erected on the machine base with the legs inserted through the guide bar 18. .
[0018]
Although the details of the injection plunger 16 are omitted in the drawing, the injection plunger 16 is provided with a ring valve on the outer periphery, and is formed between the inner wall surface of the measuring chamber 13 and the outer surface of the injection plunger 16 by the ring valve. The suction clearance is opened and closed so that the suction metering of the solution M1 in the solution holding chamber 14 shown in FIG. 2 and the injection filling of the solution M2 in the metering chamber into the mold 9 can be performed.
[0019]
The heat retaining cylinder 2 is composed of a cylinder 21 having the same inner diameter as the upper opening 14a (see FIGS. 2 and 3) of the solution holding chamber 14, and a hollow upper member 22 attached to the upper end of the cylinder 21. A communication hole 23 having the same diameter as the inner diameter of the heating cylinder 3 is formed on the rear side surface of the upper member 22. The heating cylinder 3 is mounted horizontally in contact with the tip end surface of the upper member 22 in the communicating hole 23. Further, a temperature detection terminal 25 is provided on a side portion of the cylindrical body 21, and two inert gas pipes 26 a and 26 b such as argon gas are provided in the upper member 22 so that the position of the gas ejection port has a vertical difference. It is installed vertically from the ceiling surface.
[0020]
Such a heat retaining cylinder 2 is installed vertically with the lower end of the cylinder 21 fitted around the upper opening 14a of the solution holding chamber 14 so as to be perpendicular to the upper part of the injection heating cylinder 1, whereby the inside of the cylinder is a solution. A heat insulation storage chamber 24 communicated with the holding chamber 14 at the bottom portion is formed, and a constant amount of the solution M1 is always automatically fed from the heat insulation storage chamber 24 to the solution holding chamber 14 for each injection operation of the injection plunger 16. . The capacity of the heat storage chamber 24 is preferably about 10 times the capacity of the measuring chamber 13.
[0021]
The heating cylinder 3 has a length and an inner diameter that can accommodate two normal-sized rod-shaped materials 4 (for example, a magnesium alloy, a length of 300 mm, and a diameter of 60 mm). The rod-shaped material 4 can be accommodated in the longitudinal direction. A first heater 5a for preheating and a second heater 5b for melting are attached to the front half of the cylinder in two stages, front and rear, so that the rod-shaped material 4 is preheated and melted or semi-molten. Can be performed continuously.
[0022]
The latter half of the heating cylinder 3 is inserted and supported in a transverse groove in the front-rear direction of a support block 20 provided above the injection heating cylinder 1, so that the heating cylinder 3 can be freely expanded and contracted by thermal expansion. . The support block 20 is placed and fixed on members 19 fixed on both sides of the upper surface of the support board 17b.
[0023]
On the upper part of the support block 20, a pair of side plates 61 are provided across a lateral groove so that a plurality of rod-like materials 4 can be placed horizontally between the side plates 61 so as to be stocked vertically. is there. Further, an air cylinder 63 of a pair of front and rear material receiving pins 62 is attached to the upper portion of one side surface of the support block 20 so as to be able to protrude and retract in the upper portion of the lateral groove.
[0024]
A push-in air cylinder 64 is supported by a bracket 65 below the support block 20 and is mounted rearward in parallel with the heating cylinder 3. A material push rod 67 to be inserted into the heating cylinder 3 is attached to the piston rod 66 extending and retracting horizontally from the rear end of the push air cylinder 64, and the outer end is connected to the piston rod 66 in the vertical direction. A supply device 6 for the rod-shaped material 4 falling into the second half of the heating cylinder 3 from between the side plates 61 is configured.
[0025]
In the injection apparatus configured as described above, the rod-shaped material 4 can be accommodated between the side plates 61 in a state where the material receiving pin 62 protrudes from the groove wall into the lateral groove of the support block 20. By pulling in the material receiving pin 62, the lowest rod-shaped material 4 falls into the rear half of the heating cylinder 3. Thereafter, when the material receiving pin 62 is protruded by the air cylinder 63, the material receiving pin 62 enters between the rod-shaped material 4 in the heating cylinder and the rod-shaped material 4 thereon, and receives the rod-shaped material 4 between the side plates 61. .
[0026]
This pull-in operation of the material receiving pin 62 is performed when the push rod 67 reaches the position where the rod-shaped material 4 in the rear half portion is completely pushed into the front half portion by the reduction operation of the piston rod 66 of the push air cylinder 64. Although omitted, the air cylinder 63 is actuated by a limit switch preset at that position.
[0027]
When the material receiving pin 62 is retracted, the head of the push rod 67 is in the heating cylinder, so that the lowermost rod-like material 4 is completely accommodated when the head is pulled out of the latter half, and other limits at that position. The switch operates the air cylinder 63 to receive the material receiving pin 62 by the protrusion. Therefore, the supply of the rod-shaped material 4 into the latter half is performed in connection with the material pushing.
[0028]
The material is pushed into the first half of the heating cylinder 3 in accordance with the molten state of the rod-shaped material 4 in the tip. The rod-shaped material 4 pushed into the front half is first preheated by the first heater 5a set at a low temperature (for example, 300 ° C.), and then the second heater 5b set at a high temperature (for example, 610 ° to 620 ° C.). The molten metal flows into the heat-retaining cylinder 2 maintained at a predetermined temperature from the communication hole 23 and is stored as a solution M in the heat-retaining storage chamber 24 having the solution holding chamber 14 at the bottom as far as the lower side of the communication hole 23. The The thermal insulation storage chamber 24 is always maintained in an inert gas atmosphere by the argon gas ejected into the chamber from the inert gas pipes 26a and 26b, and prevents the stored solution M from being oxidized.
[0029]
The storage amount of the solution M in the heat insulation storage chamber 24 varies depending on the mass of the metal product to be molded. However, if the solution M is stored for a long time, an intermetallic compound may be generated. It is preferable to store. This increase / decrease in the amount of storage is detected from the pressure difference in the two inert gas pipes 26a, 26b suspended in the upper part of the heat insulation storage chamber 24 with a difference in height at the position of the gas outlet.
[0030]
This detection means has already been implemented, and the liquid level of the solution M is located between the gas outlets of the inert gas pipes 26a and 26b, and the gas jet of the longer inert gas pipe 26a is located in the solution. An appropriate amount is obtained when the outlet is submerged and a pressure difference is generated between the two gas pipes due to the difference in gas ejection resistance.
[0031]
On the other hand, when the gas level of the solution M rises, both gas outlets are submerged in the solution, the pressure of the inert gas pipe 26b increases, and when there is no pressure difference between the two gas pipes, it is detected as full. As a result, the pushing air cylinder 63 stops operating and the material feeding is stopped. The material tip in the first half of the heating cylinder 3 continues to melt, but the amount is small and most of it remains in the tip. When the liquid level drops and the pressure of the inert gas pipe 26b returns to the original state due to the continuation of the injection molding in which the supply is stopped, it is detected that the full tank is released and the push-in air cylinder 63 is activated again. Then, the pushing of the rod-shaped material 4 is started.
[0032]
When the liquid level of the solution M drops and both gas outlets are exposed to the air, the pressure of the inert gas pipe 26b decreases and there is no pressure difference between the two gas pipes, it is detected that the solution is insufficient and a warning is issued. Thus, the melting supply of the material is promoted. Thus, the operation control of the supply device 6 is performed, and the storage amount of the solution M is always controlled to an appropriate amount.
[0033]
The holding temperature of the solution M in the solution storage chamber 24 varies depending on the low melting point metal material and also varies depending on the molten state. For example, in the case of the solution M melted in a liquid phase state by the heating cylinder 3 from a material having a dendritic structure even in a magnesium alloy, the temperature of the heat retaining cylinder 2 is required because the temperature needs to be retained and stored. Is set above the liquidus temperature (for example, 620 ° C.). In the case of a solution M that is a material having a spherical crystal structure and is semi-molten by the heating cylinder 3 so as to exhibit thixotropic properties, the temperature of the heat retaining cylinder 2 is the liquidus temperature and the solidus temperature of the solution M. The temperature is maintained at a temperature between (for example, 600 ° C.). Such temperature setting is similarly performed in the solution holding chamber 14 and the measuring chamber 13 following the heat insulating storage chamber 24 by the heater 5 provided outside. However, the rear end portion of the solution holding chamber 14 is set at a lower temperature (for example, around 560 ° C.) than other portions in order to prevent solution leakage.
[0034]
The solution M in the heat insulation storage chamber 24 flows into the solution holding chamber 14 at the bottom as it is from the upper opening 14a, and a predetermined amount is held in the injection heating cylinder 1 as the solution M1. The solution M1 is generated by closing the nozzle opening while the injection plunger 16 located at the forward limit of the measuring chamber 13 moves to the backward limit position by the forced backward movement of the injection rod 15 after the injection operation. Due to the negative pressure, the ring valve is sucked into the measuring chamber from the suction clearance where the ring valve is opened. Further, the same amount of the solution M flows from the solution storage chamber 24 into the solution holding chamber 14 with suction.
[0035]
The solution M2 sucked and measured in the measuring chamber 13 is injected and filled into a cavity (not shown) of the mold 9 which is closed from the nozzle opening by the injection plunger 16 which moves forward in the measuring chamber by the forward movement of the injection rod 15. To form a desired metal product. At this time, the suction clearance is closed by a ring valve that retreats due to the compression resistance of the solution M2, and the backflow of the solution M2 from the suction clearance is prevented.
[0036]
Therefore, the injection plunger 16 that moves forward and backward in the measuring chamber also serves as a pump that sequentially feeds the solution M stored in the solution storage chamber 24 as the solution M1 in the solution holding chamber 14 and the solution M2 in the measurement chamber 13. In addition, no solution transfer means is required, and the length in which the injection plunger 16 is in contact with the solution M1 is shortened. Therefore, temperature control in the entire molding machine is facilitated, and defective molding due to temperature unevenness of the solution is reduced.
[0037]
Further, the solution M1 in the solution holding chamber 14 is stirred in the axial direction by the stirring portion 15a of the annular step portion provided in the injection rod 15 every time the injection rod 15 moves back and forth. This is combined with the solution holding chamber 14 which prevents the partial retention of the solution M2 by limiting the area in comparison with the measuring chamber 13, and the effect becomes more remarkable.
[0038]
Moreover, even if it is an injection apparatus which injects and fills the stored solution M after suction metering by setting up the heat insulation storage cylinder 2 in the upper part of the solution holding chamber 14 of the injection heating cylinder 1, the solution M is stored by the insulation storage cylinder 2. The depth of the air can be sufficiently secured, so that the air that tends to occur during melting can be prevented, and the gas in the solution can escape naturally in the solution storage chamber 24, so that the injection heating is performed as before. There is no need to install the cylinder 1 at an angle with respect to the mold clamping device 8. As a result, since the injection heating cylinder 1 can be installed horizontally on the machine base and can directly touch the nozzle with the mold, a nozzle touch block, an inclined support member, etc. are not required, and the machine height is lower than that of the inclined installation. Therefore, it is possible to increase the size of the injection apparatus that employs solution storage and suction metering.
[Brief description of the drawings]
FIG. 1 is a longitudinal side view of a low melting point metal material injection apparatus according to the present invention.
FIG. 2 is a longitudinal side view of the front part of the apparatus.
FIG. 3 is a longitudinal sectional front view of the same heat retaining cylinder portion.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Injection device 2 Thermal insulation storage cylinder 3 Heating cylinder 4 Bar-shaped material 5 Heater 6 Supply device 7 Injection drive device 8 Clamping device 9 Mold 10 Machine base 11 Injection device cylinder 12 Nozzle member 13 Measuring chamber 14 Solution holding chamber 14a Opening Part 15 Injection rod 15a Stirring part 16 Injection plunger 17 Support body 21 Body 22 of heat insulation storage cylinder Upper member 24 of heat insulation storage cylinder Heat insulation storage chambers 26a, 26b Inert gas pipe 64 Pushing air cylinder 67 Pushing rod

Claims

A measuring chamber that communicates with the nozzle port at the tip, and a horizontal injection heating cylinder formed inside the solution holding chamber at the top opening inside the measuring chamber and an injection plunger at the tip are inserted into the measuring chamber so that they can move forward and backward. The injection rod provided in the injection heating cylinder and the injection drive device at the rear part of the injection heating cylinder connected to the rear end of the injection rod, and the solution in the solution holding chamber is transferred to the measuring chamber by the forced retraction of the injection plunger. An injection device for low melting point metal material for suction metering,
A solution heat storage cylinder is erected in the upper part of the solution holding chamber of the injection heating cylinder, and a heating cylinder provided with a rod-shaped material insertion portion on one end is connected to the upper side of the heat storage cylinder in a horizontally long shape. The solution of the low melting point metal material melted by the heating cylinder is stored in the heat insulation storage chamber in the heat insulation storage cylinder, and the solution in the heat insulation storage chamber can be automatically fed to the solution holding chamber by the injection operation of the injection plunger. A low-melting-point metal material injection device characterized by comprising:

2. The low melting point metal material injection apparatus according to claim 1, wherein an area ratio of the measuring chamber to the solution holding chamber is 1: 1 to 1: 2.

The low-melting-point metal material injection device according to claim 1 or 2, wherein the injection rod has a stirring portion having a plurality of annular step portions at a portion located in the solution holding chamber.

The low-melting-point metal material injection apparatus according to claim 1, wherein the heat retaining cylinder includes an inert gas pipe such as argon gas in an upper part of the heat retaining chamber.

2. The inert gas pipe according to claim 1, wherein the inert gas pipe comprises a plurality of inert gas pipes whose gas outlets are vertically different from each other, and has means for detecting an increase / decrease in a solution storage amount from a pressure difference between the inert gas pipes. Alternatively, the low melting point metal material injection device according to 4.