JP3595320B2

JP3595320B2 - Mold molding method and apparatus and method of using the same

Info

Publication number: JP3595320B2
Application number: JP2002212698A
Authority: JP
Inventors: 諭三金平; 義彦大島
Original assignee: Metal Engineering KK
Current assignee: Metal Engineering KK
Priority date: 2002-07-22
Filing date: 2002-07-22
Publication date: 2004-12-02
Anticipated expiration: 2022-07-22
Also published as: JP2004050251A

Description

【０００１】
【発明の属する技術分野】
本発明は、スクイズヘッドに装架された複数のスクイズフートとスクイズテーブルとの相対移動により模型定盤上に重合された鋳枠に充填された鋳物砂をスクイズして鋳型を造型する鋳型造型方法および装置並びにその使用方法に関するものである。
【０００２】
【従来の技術】
鋳型造型のために模型定盤に載置される模型は、形状が比較的小径で背が高い円筒状のもの、或いは複数の背の高い模型が狭い間隔で並べられる場合がある。このような場合、円筒状模型の内部および並置された模型の間には、鋳物砂の充填が悪く、他の部分との間に極端な鋳型の強度差が発生する。この対策として、分割型のスクイズフートを用い、鋳物砂が充填されにくい難充填箇所に対向するクイズフートの加圧力を高くする方法、又は難充填箇所に対向するクイズフートを他のスクイズフートよりスクイズ前に予め突出させておく方法等が行われている。
【０００３】
【発明が解決しようとする課題】
難充填箇所に対向するスクイズフートの加圧力を高くする従来の方法は、全てのスクイズフートを鋳物砂に背面側から比較的高い圧力で同時に押し当てて加圧するため、加圧初期の段階で鋳型全体の強度が高まってしまい、難充填箇所に対向するスクイズフートの加圧力を高めても難充填箇所の深部にスクイズ圧力が到達せず殆ど効果がない。
【０００４】
また、難充填箇所に対向するクイズフートを予め突出させておく方法は、難充填箇所を局部的に先行してスクイズするので、難充填箇所の深部にスクイズ圧力を伝達する効果はあるが、スクイズフートを鋳物砂の背面に打ち込むためのスクイズストロークが長くなり、スクイズ時間が長くなる。スクイズ時間を短縮するためにスクイズ速度を速くすると動力が増大し、設備コストが高くなる不具合があった。
【０００５】
本発明は、係る従来の不具合を解消するためになされたもので、鋳物砂が充填されにくい難充填箇所の深部にまで予備スクイズ圧力が伝達できるようにし、難充填箇所の鋳型硬度を高めることである。
【０００６】
【課題を解決するための手段】
上記の課題を解決するため、請求項１に記載の発明の構成上の特徴は、造型経路に沿って相対的に進退移動するスクイズテーブルとスクイズヘッドを設け、鋳枠が載置される模型定盤を前記スクイズテーブル上に配置し、前記スクイズヘッドに複数のスクイズフートを前記スクイズテーブルに向かって前記造型経路方向に進退可能に装架し、前記鋳枠内に投入された鋳物砂を前記スクイズテーブルと前記スクイズヘッドとを相対的に接近させて前記複数のスクイズフートによりスクイズを行う鋳型造型方法において、前記複数のスクイズフートを同一条件に維持した状態で前記スクイズテーブルと前記スクイズヘッドとを相対的に接近させ前記鋳物砂を予備スクイズした後、鋳物砂が充填されにくい難充填箇所に対向するスクイズフートを残りのスクイズフートより突出させて前記鋳物砂を充填予備スクイズすることである。
【０００７】
請求項２に係る発明の構成上の特徴は、造型経路に沿って相対的に進退移動するスクイズテーブルとスクイズヘッドを設け、鋳枠が載置される模型定盤を前記スクイズテーブル上に配置し、前記スクイズヘッドに複数のスクイズフートを前記造型経路方向に移動可能に装架し、各スクイズフートを独立して前記スクイズテーブルに向かって進退させる手段を設け、前記鋳枠内に投入された鋳物砂を前記スクイズテーブルと前記スクイズヘッドとを相対的に接近させて前記複数のスクイズフートによりスクイズを行う鋳型造型装置において、前記複数のスクイズフートを同一条件に維持した状態で前記スクイズテーブルと前記スクイズヘッドとを相対的に接近させ前記鋳物砂を予備スクイズする手段と、鋳物砂が充填されにくい難充填箇所に対向するスクイズフートを残りのスクイズフートより突出させて前記鋳物砂を充填予備スクイズする手段を備えたことである。
【０００８】
請求項３に係る発明の構成上の特徴は、造型経路に沿って相対的に進退移動するスクイズテーブルとスクイズヘッドを設け、鋳枠が載置される模型定盤を前記スクイズテーブル上に配置し、前記スクイズヘッドに複数のスクイズフートを前記スクイズテーブルに向かって前記造型経路方向に進退可能に装架し、前記スクイズヘッドに前記スクイズフートに連結されたピストン部を夫々収納する複数のシリンダを設け、該シリンダの各々に対応して開閉弁を設け、各開閉弁の一方ポートを対応するシリンダに接続し、各開閉弁の他方ポートを共通油路に接続し、前記鋳枠内に投入された鋳物砂を前記スクイズテーブルと前記スクイズヘッドとを相対的に接近させて前記複数のスクイズフートによりスクイズを行う鋳型造型装置において、前記開閉弁により前記共通油路に連通された前記シリンダの内部圧力を設定圧力に制御するために前記共通油路に接続された圧力制御弁と、前記複数のスクイズフートの全部を同一条件に維持した状態で前記スクイズテーブルと前記スクイズヘッドとを相対的に接近させて前記鋳枠内に投入された鋳物砂を前記複数のスクイズフートにより予備スクイズする手段と、前記予備スクイズ後に、鋳物砂が充填されにくい難充填箇所に対向するシリンダに接続された開閉弁は閉状態で、他の開閉弁は開状態にして他のシリンダ内の圧力を前記圧力制御弁により設定された圧力に維持した状態で前記スクイズテーブルと前記スクイズヘッドとを相対的に接近させて前記鋳枠内に投入された鋳物砂を充填予備スクイズする手段とを備えたことである。
【０００９】
請求項４に係る発明の構成上の特徴は、請求項３において、前記スクイズテーブルとスクイズヘッドとの相対位置を検出する位置検出装置、又は前記スクイズテーブルとスクイズヘッドとを相対的に接近させるための油圧駆動装置に発生する圧力を検出する圧力検出装置を設け、前記位置検出装置又は圧力検出装置により検出された前記相対位置又は圧力に基づいて、鋳物砂が充填されにくい難充填箇所に対向するシリンダに接続された開閉弁を開状態に切り換え、且つ前記圧力制御弁の設定圧力を本スクイズ圧にセットすることである。
【００１０】
請求項５に係る発明の構成上の特徴は、請求項４において、鋳物砂が充填されにくい複数の難充填箇所に夫々対向する複数のシリンダに接続された複数の開閉弁を、前記位置検出装置又は圧力検出装置により検出された前記相対位置又は圧力に基づいて鋳物砂充填の難度が高いほど後に開状態に順次切り換え、全開閉弁が開状態になると前記圧力制御弁の設定圧力を本スクイズ圧にセットすることである。
【００１１】
請求項６に係る発明の構成上の特徴は、請求項３乃至５のいずれかにおいて、前記複数のシリンダを前記ヘッド本体に穿設し、各シリンダに夫々対応する開閉弁を前記ヘッド本体に取り付けたことである。
【００１２】
請求項７に係る発明の構成上の特徴は、請求項３乃至６のいずれかにおいて、前記各開閉弁の一方のポートと他方のポートを結ぶ短絡回路に前記シリンダ内の圧力が設定以上になると圧油を前記共通油路に逃すレリーフ弁を設けたことである。
【００１３】
請求項８に係る発明の構成上の特徴は、前記請求項３乃至７のいずれかに記載の鋳型造型装置を使用した造型方法において、前記複数のスクイズフートの全部を同一条件に維持した状態で前記スクイズテーブルと前記スクイズヘッドとを相対的に接近させて前記鋳枠内に投入された鋳物砂を前記複数のスクイズフートにより予備スクイズし、予備スクイズを終了した後、鋳物砂が充填されにくい難充填箇所に対向する前記シリンダに接続された開閉弁は閉状態で、他のシリンダに接続された開閉弁は開状態で前記スクイズテーブルと前記スクイズヘッドとを相対的に接近させて前記鋳枠内に投入された鋳物砂を充填予備スクイズし、前記位置検出装置又は圧力検出装置により検出された前記相対位置又は圧力に基づいて閉状態の開閉弁を開状態に切り換え、前記圧力制御弁の設定圧力を本スクイズ圧にセットすることである。
【００１４】
【発明の作用・効果】
上記のように構成した請求項１に係る発明においては、スクイズテーブルとスクイズヘッドとを相対的に接近させて同一条件に維持された複数のスクイズフートにより鋳物砂を予備スクイズする。予備スクイズが終了すると、鋳物砂が充填されにくい難充填箇所に対向するスクイズフートを残りのスクイズフートより突出させて難充填箇所の深部にまで圧力を伝達して充填予備スクイズする。
【００１５】
鋳物砂を先ず予備スクイズすることにより、鋳物砂全体の硬度を圧力伝達が可能な範囲内である程度高くし、この状態で難充填箇所に対向するスクイズフートを突出させて充填予備スクイズするので、突出されたスクイズフートにより発生された圧力の分散が予備スクイズされた回りの鋳物砂により防止され、難充填箇所の深部にまで充填予備スクイズ圧力が伝達され、難充填箇所の鋳型硬度を高めることができる。また、鋳物砂全体を予備スクイズにより適当な硬さにすることで、充填予備スクイズでの難充填箇所に対向するスクイズフートの突出量を短くできるので、設備コストを低減し、短時間に難充填箇所の深部にまで圧力を伝達して充填予備スクイズすることができ、従来充填不足であった難充填箇所の鋳型強度を高めることができる。
【００１６】
上記のように構成した請求項２に係る発明においては、スクイズテーブルとスクイズヘッドとを相対的に接近させて同一条件に維持された複数のスクイズフートにより鋳物砂を予備スクイズする。予備スクイズが終了すると、鋳物砂が充填されにくい難充填箇所に対向するスクイズフートを残りのスクイズフートより突出させて難充填箇所の深部にまで圧力を伝達して充填予備スクイズする。
【００１７】
請求項１に記載の発明の効果に加え、短時間に難充填箇所の深部にまで圧力伝達し、従来充填不足であった難充填箇所の鋳型強度を高めることができる低コストの鋳型造型装置を提供することができる。
【００１８】
上記のように構成した請求項３に係る発明においては、複数のスクイズフートの全部を同一条件に維持した状態でスクイズテーブルとスクイズヘッドとを相対的に接近させて鋳枠内に投入された鋳物砂を複数のスクイズフートにより予備スクイズする。予備スクイズ後に、鋳物砂が充填されにくい難充填箇所に対向するシリンダに接続された開閉弁は閉状態で、他の開閉弁は開状態にして他のシリンダ内の圧力を圧力制御弁により設定された圧力に維持した状態でスクイズテーブルとスクイズヘッドとを相対的に接近させ、鋳枠内に投入された鋳物砂を充填予備スクイズする。
【００１９】
鋳物砂を先ず予備スクイズして鋳物砂全体の硬度を圧力伝達が可能な範囲内である程度高くした後に、難充填箇所に対向するシリンダに接続された開閉弁は閉状態で、他のシリンダは内部圧力を設定圧に維持した状態で、充填予備スクイズするので、閉状態の開閉弁により後退を阻止されて他より突出したスクイズフートにより発生された圧力の分散が予備スクイズされた回りの鋳物砂により防止され、難充填箇所の深部にまで圧力が伝達され、難充填箇所の鋳型硬度を高めることができる。また、鋳物砂全体を予備スクイズにより適当な硬さにすることで、難充填箇所に対向するスクイズフートを突出させた状態での充填予備スクイズを短いストロークで行うことが可能となるので、短時間に難充填箇所の深部にまで圧力を伝達して充填予備スクイズすることができる低コストの鋳型造型装置を提供することができる。
【００２０】
上記のように構成した請求項４に係る発明においては、スクイズテーブルとスクイズヘッドの相対位置、又はスクイズテーブルとスクイズヘッドとを相対的に接近させるために油圧駆動装置に発生する圧力が所定値になると、全開閉弁を開状態に切り換えて充填予備スクイズを終了し、圧力制御弁の設定圧力を高くして本スクイズを行う。これにより、簡単な構成で充填予備スクイズから本スクイズに確実に切り換えることができる。
【００２１】
上記のように構成した請求項５に係る発明においては、鋳物砂が充填されにくい難充填箇所が複数ある場合に、該複数の難充填箇所に夫々対向する複数のシリンダに接続された複数の開閉弁を、鋳物砂充填の困難性が高い箇所ほど後に開状態に順次切り換える。これにより、鋳物砂充填の困難性が高い箇所ほどより突出したスクイズフートにより充填予備スクイズすることができるので、複数の難充填箇所を鋳物砂充填の困難性に拘わらず略均等の硬さに充填予備スクイズすることができる。
【００２２】
上記のように構成した請求項６に係る発明においては、複数のスクイズフートのピストン部を夫々収納する複数のシリンダをスクイズヘッドのヘッド本体に穿設し、該シリンダの各々に対応する開閉弁をヘッド本体に取り付けたので、構成が極めて簡単になり、コスト低減することができる。
【００２３】
上記のように構成した請求項７に係る発明においては、鋳物砂が充填されにくい難充填箇所に対向するシリンダに接続された開閉弁を閉状態にして充填予備スクイズするとき、圧力が設定値以上になったシリンダ内の圧油はレリーフ弁によって共通油路に逃がされるので、難充填箇所に対向するスクイズフートの中の一部に圧力が集中することがなく、鋳物砂を局部的に過大な圧力で充填予備スクイズすることが防止できる。
【００２４】
上記のように構成した請求項８に係る発明においては、複数のスクイズフートの全部を同一条件に維持した状態でスクイズテーブルとスクイズヘッドとを相対的に接近させて鋳枠内に投入された鋳物砂を複数のスクイズフートにより予備スクイズする。予備スクイズが終了すると、鋳物砂が充填されにくい難充填箇所に対向するシリンダに接続された開閉弁は閉状態で、他のシリンダに接続された開閉弁は開状態でスクイズテーブルとスクイズヘッドとを相対的に接近させて鋳物砂を圧力制御弁により設定された圧力で充填予備スクイズする。充填予備スクイズが終了すると、全開閉弁を開状態にし、圧力制御弁の設定圧力を高くして本スクイズを行う。
【００２５】
鋳物砂を先ず予備スクイズして鋳物砂全体の硬度を圧力伝達が可能な範囲内である程度高くした後に、充填予備スクイズするので、他より突出したスクイズフートにより発生された充填予備スクイズ圧力が難充填箇所の深部にまで伝達され、難充填箇所の鋳型硬度を高めることができる。また、鋳物砂全体を予備スクイズにより適当な硬さにすることで、充填予備スクイズを短いストロークで行うことが可能となり、短時間、低コストで難充填箇所の深部にまで圧力を伝達して充填予備スクイズすることができ、従来充填不足であった難充填箇所の鋳型強度を高めることができる。
【００２６】
【実施の形態】
以下本発明に係る鋳型造型方法および装置の第１の実施形態を図面に基づいて説明する。図１において、１はスクイズテーブルで、油圧駆動装置としてのシリンダ装置２によって上下の造型経路方向に進退移動されるようになっている。スクイズテーブル１上面には円筒状の２個の模型３ａ，３ｂが取付けられた模型定盤４が固定されている。模型定盤４上には鋳枠５および上盛枠６が重合して載置され、鋳枠５および上盛枠６内に計量された鋳物砂７が公知の鋳物砂供給装置から投入されるようになっている。
【００２７】
シャトル８の下面にはスクイズヘッド９と鋳物砂供給装置とが並んで取り付けられ、シャトル８が図略のシリンダ装置によってスクイズ位置に割り出されるとスクイズヘッド９がスクイズテーブル１と対向し、鋳物砂供給位置に割り出されると鋳物砂供給装置がスクイズテーブル１と対向するようになっている。スクイズヘッド９には複数のスクイズフート１０がスクイズテーブル１に向かって造型経路方向に夫々独立して進退可能に装架されている。スクイズヘッド９のヘッド本体１１には複数のシリンダ１２が造型経路方向に穿設され、スクイズフート１０のピストン部１３が夫々摺動可能に嵌合して収納されている。スクイズフート９は鋳枠５の内側全域に亙って配置され、鋳枠５に投入された鋳物砂７を万遍なくスクイズするようになっている。
【００２８】
シリンダ１２の各々に対応して開閉弁１４がヘッド本体１１上に取り付けられている。各開閉弁１４の一方ポート１５は対応するシリンダ１２に接続され、全開閉弁１４の他方ポート１６はヘッド本体１１に穿設された共通油路１７に接続されている。なお、共通油路１７はパイプで構成してヘッド本体１１上に固定してもよい。
【００２９】
共通油路１７には、電磁圧力制御弁１８の一方ポートが接続され、開閉弁１４により共通油路１７に連通されたシリンダ１２の背圧を設定圧力に制御する。電磁圧力制御弁１８の他方ポートは切換弁１９により油圧源２０およびタンクに選択的に接続されるようになっている。共通油路１７と切換弁１９との間には、チェック弁２３が電磁圧力制御弁１８と並列に接続されている。２２は制御装置で、スクイズテーブル１の上下方向位置を検出する位置検出装置２１からの信号に基づいて、各開閉弁１４、電磁圧力制御弁１８、電磁切換弁１９に指令信号を送出する。位置検出装置２１は、スクイズテーブル１とスクイズヘッド９との相対位置を検出する位置検出装置として機能する。
【００３０】
上記のように構成した実施形態の作動とともに、該実施形態に係る鋳型造型装置を使用した造型方法について説明する。テーブル１の上面に固定した模型定盤４上に鋳枠５および上盛枠６が重ねて載置され、シャトル８が鋳物砂供給位置に割り出されて定量した鋳物砂７が鋳枠５および上盛枠６内に投入される。シャトル８がスクイズ位置に割り出され、スクイズヘッド９がスクイズテーブル１と対向される。このとき油圧源２０から圧油が切換弁１９、チェック弁２３、ソレノイドの無勢により開状態にされた全開閉弁１６を通って全シリンダ１２に供給され、全スクイズフート１０が前進端に突出されている。
【００３１】
次に、制御装置２２は、図２に示すように、電磁圧力制御弁１８のリニアソレノイドに予備スクイズ圧に相当する制御電流を印加し、切換弁１９を切り換えて電磁圧力制御弁１８をタンクに連通する。
【００３２】
この状態でスクイズテーブル１がシリンダ装置２によってスクイズヘッド９に向かって上昇され、全スクイズフート１０が鋳枠５内に投入された鋳物砂７に当接して上方に押圧され、各開閉弁１４により互いに連通された全シリンダ１２内の圧力は等圧で上昇し、予備スクイズ圧まで上昇すると電磁圧力制御弁１８、切換弁１９を介してタンクに排出される。このように、スクイズテーブル１とスクイズヘッド９との相対的な接近により、鋳枠５内に投入された鋳物砂７は、同一条件の等圧に維持された複数のスクイズフート１０により予備スクイズされる（図３）。制御装置２２により全部を開状態にされた開閉弁１４、予備スクイズ圧に背圧を設定された電磁圧力制御弁１８、シリンダ装置２等により、複数のスクイズフート１０の全部を同一条件に維持した状態でスクイズテーブル１とスクイズヘッド９とを相対的に接近させて鋳枠５内に投入された鋳物砂７を複数のスクイズフート１０により予備スクイズする手段が構成されている。
【００３３】
スクイズテーブル１が予備スクイズ終了位置まで上昇されたことが、位置検出装置２１により検出されると、鋳枠５内で鋳物砂７が充填されにくい難充填箇所に対向するシリンダ１２に接続された開閉弁１４はソレノイドを付勢して閉状態に切り換えられる。図２において円筒状の模型３ａ，３ｂの内周面は高い壁に囲まれた隘路部となり、鋳物砂が充填されにくい難充填箇所であり、模型３ａに対向するスクイズフート１０のピストン部を収納するシリンダ１２および模型３ｂに半分づつ対向する２個のスクイズフート１０のピストン部を収納する２個のシリンダ１２に夫々接続された３個の開閉弁１４が閉状態に切り換えられ、シリンダ１２からの圧油の排出がブロックされてスクイズフート１０の後退が規制される。難充填箇所に対向するスクイズフート１０を収納するシリンダ１２に接続された３個の開閉弁１４は、制御装置２２に予め登録されている。なお、複数の背の高い模型が模型定盤４に狭い間隔で並べて固定された場合、背の高い模型に挟まれた隘路部が、鋳物砂が充填されにくい難充填箇所となる。
【００３４】
スクイズテーブル１はシリンダ装置２によりスクイズヘッド９に向かって更に上昇され、切換弁１４が開状態に維持されたスクイズフート１０は、シリンダ１２内の圧油が電磁圧力制御弁１８、切換弁１９を介してタンクに排出されて後退するが、切換弁１４が閉状態にされたスクイズフート１０は、シリンダ１２内の圧油の排出がブロックされるので後退が規制され、他のスクイズフート１０により突出する。円筒状模型３ａ，３ｂの内部には、スクイズテーブル１の上昇につれて他のスクイズフートより突出したスクイズフート１０より鋳物砂７が充填され、充填予備スクイズされる（図４）。制御装置２２により一部が閉状態、残りが開状態にされた開閉弁、電磁圧力制御弁１８及びシリンだ装置２等により、予備スクイズ後に、鋳物砂７が充填されにくい難充填箇所に対向するシリンダ１２に接続された開閉弁１４は閉状態で、他の開閉弁１４は開状態にして他のシリンダ１２内の圧力を電磁圧力制御弁１８により設定された圧力に維持した状態でスクイズテーブル１とスクイズヘッド９とを相対的に接近させて鋳枠５内に投入された鋳物砂７を充填予備スクイズする手段が構成されている。
【００３５】
円筒状の模型３ｂは模型３ａより背が低く、深部に鋳物砂７が充填されにくくて鋳物砂充填の難度が高い。このように鋳物砂充填の難度が異なる複数の難充填箇所がある場合、鋳物砂充填の難度が低い模型３ａの内部に鋳物砂７が先に充填される。模型３ａ内部に鋳物砂の充填を終了した位置までスクイズテーブル１が上昇したことが、位置検出装置２１により検出されると、模型３ａに対向するシリンダ１２に接続された開閉弁１４が開状態に切り換えられる。その後のスクイズテーブル１の上昇により、鋳物砂充填の難度が高い模型３ｂに対抗する２個のスクイズフート１０が後退を規制されて円筒状模型３ｂの内部に鋳物砂７を充填する（図５）。
【００３６】
模型３ｂ内部に鋳物砂の充填を終了した位置までスクイズテーブル１が上昇したことが、位置検出装置２１により検出されると、模型３ｂに対向するシリンダ１２に接続された開閉弁１４が開状態に切り換えられ、電磁圧力制御弁１８のリニアソレノイドに本スクイズ圧である最終スクイズ圧に相当する制御電流が印加される。なお、模型３ａ又は３ｂ内部への鋳物砂の充填を終了したスクイズテーブル１の位置は、試験を繰り返して設定される。
【００３７】
この状態でスクイズテーブル１がシリンダ装置２によってスクイズヘッド９に向かって上昇され、全スクイズフート１０が鋳物砂７を同一圧力で本スクイズとして最終スクイズする。スクイズ完了位置にスクイズテーブル１が上昇したことが、位置検出装置２１により検出されると、制御装置２２は、図７に示すように、シリンダ装置２によりスクイズテーブル１を下降端まで下降させ、全開閉弁１４のソレノイドを無勢したまま切換弁１９のソレノイドを無勢する。これにより油圧源２０から圧油がチェック弁２３を介してシリンダ１２に供給され、スクイズフート１０が全て前進端に復帰される。
【００３８】
図８は高さ７０ｍｍ、内径７５ｍｍの円筒状模型３の鋳型を本方法により造型した場合の鋳型強度を従来方法で造型した場合と比較したグラフである。円筒状模型３に対向するスクイズフート１０の他のスクイズフート１０からの突出量Ａ（図９参照）を種々変えた場合の、円筒状模型３の底中央部Ｂの鋳型強度の変化が示されている。図８から明らかなように、鋳物砂７が充填されにくい円筒状模型３に対向するスクイズフート１０を突出して充填予備スクイズする前に、本発明のように予備スクイズを行うと、突出量Ａが７５ｍｍ，１００ｍｍの場合、鋳型強度が１７５％，１８５％と飛躍的に高くなる。このように、本発明によれば、突出量Ａが小さくても難充填箇所に鋳物砂を良好に充填することができ、充填予備スクイズを短いストロークで効果的に行うことができる。
【００３９】
図１０に示す第２実施形態のように、各開閉弁１４の一方ポート１５と他方ポート１６とを結ぶ短絡回路２４に各シリンダ１２内の圧力が設定以上になると圧油を共通油路１７に逃がすレリーフ弁２５を夫々接続するとよい。これにより、鋳物砂７が充填されにくい難充填箇所に対向するシリンダ１２に接続された開閉弁１４を閉状態にして充填予備スクイズするとき、圧力が設定値以上になったシリンダ１２内の圧油がレリーフ弁２５によって共通油路１７に逃がされるので、難充填箇所に対向するスクイズフート１０の中の一部に圧力が集中することがなく、鋳物砂１７を局部的に過大な圧力で充填予備スクイズすることが防止できる。
【００４０】
図１１に示す第３の実施形態においては、スクイズテーブル１に載置されたキャリアプレート３０上に模型定盤４が固定され、下盛枠３１がキャリアプレート３０に模型定盤４を取り囲んで上下動可能に装架されている。スクイズテーブル１の４隅にはシリンダ装置３２が設けられ、このシリンダ装置３２のピストンロッドの昇降によって下盛枠１０が上昇位置と後退位置との間で移動される。下盛枠３１がシリンダ装置３２により上昇位置に上昇された状態で、スクイズテーブル１がシリンダ装置２により上昇されると、ローラコンベア３４上に支持された鋳枠５が下盛枠３１の上面に鋳枠受渡位置で載置され、上盛枠６が鋳枠５上面に当接され、図１２に示す鋳物砂投入位置でスクイズテーブル１が一時停止され、これら重合された下盛枠３１、鋳枠５、上盛枠６内に鋳物砂７が投入される。
【００４１】
鋳物砂７が投入されると、電磁圧力制御弁１８のソレノイドに予備スクイズ圧に相当する制御電流が印加され、全開閉弁１４が開状態でスクイズテーブル１がシリンダ装置２によってスクイズヘッド９に向かって上昇され、全スクイズフート１０が鋳枠５内に投入された鋳物砂７を均等に予備スクイズする。予備スクイズが終了したことが位置検出装置２１により検出されると、鋳枠５内で鋳物砂７が充填されにくい難充填箇所に対向するシリンダ１２に接続された開閉弁１４が閉状態に切り換えられる。スクイズテーブル１はシリンダ装置２によりスクイズヘッド９に向かって更に上昇され、切換弁１４が閉状態にされて後退を規制されたスクイズフート１０は、難充填箇所に鋳物砂７を充填して充填予備スクイズする。充填予備スクイズが終了したことが位置検出装置２１により検出されると、全開閉弁１４が開状態にされ、電磁圧力制御弁１８のリニアソレノイドに模型面側スクイズ圧に相当する制御電流が印加される。スクイズテーブル１が、スクイズヘッド９に設けたシリンダ装置３３により上盛枠６の上昇が規制された状態で、下盛枠３１の鋳枠５との当接面が後退位置に後退するまで上昇され、鋳物砂７が本スクイズとして模型面側スクイズされる。模型面側スクイズが終了すると、電磁圧力制御弁１８のリニアソレノイドに最終スクイズ圧に相当する制御電流が印加され、シリンダ装置３３による上盛枠６の上昇規制が解除され、スクイズテーブル１が上昇されて全スクイズフート１０が鋳物砂７を最終スクイズする。スクイズテーブル１が上昇端に位置して最終スクイズが完了すると、スクイズテーブル１はシリンダ装置２により下降され、鋳枠６を鋳枠受渡位置でローラコンベア３４上に移載して模型３ａ，３ｂを離型した後、下降端に停止される。
【００４２】
図１３，１４に示す第４の実施形態では、スクイズヘッド３５がスクイズテーブル１に対向して機枠に固定され、スクイズヘッド３５には複数の嵌合孔３６が穿設され、各嵌合孔３６にスクイズフート３７が上下方向に摺動可能に嵌合されている。スクイズヘッド３５の上面には各嵌合孔３６を塞ぐようにシリンダ装置３８が夫々固定され、各シリンダ装置３８のピストンが各スクイズフート３７に連結されスクイズフート３７を夫々独立して上下動する。スクイズヘッド３５の外周部分には、全嵌合孔３６及び全シリンダ装置３８を取り巻く帯域に複数の鋳物砂供給穴３９が穿設され、スクイズヘッド３５の上面には、該帯域の外周縁と内周縁でブロー通路４０の外周壁と内周壁とが固定されている。
【００４３】
スクイズテーブル１がシリンダ装置２により上昇され、スクイズテーブルに固定された模型定盤４上に重合された鋳枠５、上盛枠６が上昇され、上盛枠６がスクイズヘッド３５の外周に嵌合すると、スクイズテーブル１が一時停止される。各スクイズフート３７は、各下端面がスクイズヘッド３５の下面と整列する後退端に各シリンダ装置３８により後退されている。この状態で、ブロー通路４０を通って鋳物砂７が圧縮エアにより鋳枠５と上盛枠６内に投入される（図１３）。
【００４４】
次に、スクイズテーブル１がシリンダ装置２によってスクイズヘッド３５に向かって上昇され、全スクイズフート３７が鋳枠５内に投入された鋳物砂７を均等に予備スクイズする。スクイズテーブル１が予備スクイズ終了位置に上昇したことが位置検出装置により検出されると、鋳枠５内で鋳物砂７が充填されにくい難充填箇所に対向するスクイズフート３７がシリンダ装置３８により前進され、鋳物砂７を難充填箇所に充填して充填予備スクイズする（図１４）。その後、スクイズテーブル１がシリンダ装置２によってスクイズヘッド３５に向かって上昇され、全スクイズフート３７が鋳物砂７を同一圧力で最終スクイズする。なお、スクイズテーブル１を昇降させるシリンダ装置２に発生する圧力を検出する圧力検出装置を設け、該圧力検出装置により検出された圧力に基づいて充填予備スクイズの開始時期及び終了時期を決めるようにしてもよい。
【００４５】
上記各実施形態では、スクイズテーブル１をシリンダ装置２により昇降させてスクイズテーブル１とスクイズヘッド９とを相対的に接近させているが、スクイズヘッド９，３５をシリンダ装置によりスクイズテーブル１に向かって昇降させるようにしてもよい。
【００４６】
上記第１乃至第３実施形態では、スクイズテーブル１が難充填箇所への鋳物砂の充填を終了した位置に上昇したことが検出されると、全開閉弁１４を開状態にして充填予備スクイズを終了しているが、スクイズテーブル１を昇降させるシリンダ装置２に発生する圧力を検出する圧力検出装置を設け、該圧力検出装置により検出された圧力に基づいて充填予備スクイズを終了するようにしてもよい。
【００４７】
上記実施形態では、複数のスクイズフート１０のピストン部を夫々嵌合する複数のシリンダ１２に夫々接続された開閉弁１４の全部を開状態にして全シリンダ１２内の圧力を予備スクイズ圧に維持することにより、複数のスクイズフート１０を同一条件に維持して鋳物砂７を予備スクイズしているが、開閉弁１４の全部を閉状態にして全スクイズフート１０の後退を規制した状態で、スクイズテーブル１を予備スクイズ終了位置まで上昇させることにより、複数のスクイズフート１０を同一条件に維持して鋳物砂７を予備スクイズするようにしてもよい。
【００４８】
また、上記実施形態では、鋳物砂７の投入後に全開閉弁１６を開状態にし、予備スクイズ終了後に鋳物砂７が充填されにくい難充填箇所に対向するシリンダ１２に接続された開閉弁１４を閉状態に切り換えているが、鋳物砂７の投入後に難充填箇所に対向するシリンダ１２に接続された開閉弁１４を閉状態にし、他の開閉弁１４を開状態にすると、シリンダ１２内の圧力が電磁圧力制御弁１８により設定された予備スクイズ圧になるまでの間で、全スクイズフート１０が前進端に維持された同一条件で鋳物砂７が予備スクイズされ、シリンダ１２内の圧力が予備スクイズ圧に達すると、開閉弁１４が閉状態にされたスクイズフート１０が突出して充填予備スクイズを行うこととなる。
【００４９】
上記実施形態では、前進端に位置する複数のスクイズフート１０の下端面位置は同一高さにしているが、例えば鋳枠５の周壁近傍のスクイズフート１０の下端面位置を若干下げてもよい。このように一部のスクイズフート１０の形状を変えても、予備スクイズ時の各シリンダ１２内の圧力を同一にし、又は全スクイズフートの後退を規制して予備スクイズを行う限り、同一条件に維持された複数のスクイズフートにより予備スクイズが行われることとなる。
【図面の簡単な説明】
【図１】本発明に係る鋳型造型装置の第１の実施形態を示す図。
【図２】鋳物砂投入時の状態を示す図。
【図３】予備スクイズ時の状態を示す図。
【図４】背が高い円筒状模型に充填予備スクイズした状態を示す図。
【図５】背が低い円筒状模型に充填予備スクイズした状態を示す図。
【図６】最終スクイズした状態を示す図。
【図７】スクイズを完了した状態を示す図。
【図８】本発明方法と従来方法で造型した鋳型の強度を比較したグラフ。
【図９】図８のグラフに示す突出量Ａ、鋳型強度の測定箇所Ｂを示す図。
【図１０】第２の実施形態を示す図。
【図１１】第３の実施形態を示す図。
【図１２】第３の実施形態の鋳物砂を投入した状態を示す図。
【図１３】第４の実施形態を示す図。
【図１４】第４の実施形態の充填予備スクイズした状態を示す図。
【符号の説明】
１…スクイズテーブル、２…シリンダ装置、３ａ，３ｂ…模型、４…模型定盤、５，…鋳枠、６…上盛枠、７…鋳物砂、８…シャトル、９，３５…スクイズヘッド、１０，３７…スクイズフート、１１…ヘッド本体、１２…シリンダ、１３…ピストン部、１４…開閉弁、１５…一方ポート、１６…他方ポート、１８…電磁圧力制御弁（圧力制御弁）、１９…切換弁、２０…油圧源、２１…位置検出装置、２２…制御装置、２３…チェック弁、２４…短絡回路、２５…レリーフ弁、３０…キャリアプレート、３１…下盛枠、３２，３３…シリンダ装置、３９…鋳物砂供給穴、４０…ブロー通路。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention provides a mold forming method for forming a mold by squeezing molding sand filled in a casting frame superimposed on a model platen by a relative movement between a plurality of squeeze feet mounted on a squeeze head and a squeeze table. And an apparatus and a method of using the same.
[0002]
[Prior art]
The model placed on the model platen for mold molding may have a relatively small diameter and a tall cylindrical shape, or a plurality of tall models may be arranged at narrow intervals. In such a case, the molding sand is poorly filled inside the cylindrical model and between the juxtaposed models, and an extreme difference in the strength of the mold is caused between other models. As a countermeasure, using a split type squeeze foot, a method of increasing the pressing force of the quiz foot facing the difficult-to-fill location where casting sand is difficult to fill, or the quiz foot facing the difficult-to-fill location before squeezing from other squeeze foot A method of projecting in advance is performed.
[0003]
[Problems to be solved by the invention]
The conventional method of increasing the pressing force of the squeeze foot facing the difficult filling point is to press all the squeeze foot against the molding sand at the same time with relatively high pressure from the back side and pressurize. The overall strength is increased, and even if the pressing force of the squeeze foot facing the difficult-to-fill portion is increased, the squeeze pressure does not reach the deep portion of the difficult-to-fill portion, and there is almost no effect.
[0004]
In addition, the method of protruding the quiz foot facing the difficult-to-fill portion in advance has the effect of transmitting the squeeze pressure to the deep portion of the difficult-to-fill portion, since the squeeze pressure is transmitted locally to the difficult-to-fill portion. The squeeze stroke for driving the sand into the back of the casting sand becomes longer, and the squeeze time becomes longer. If the squeeze speed is increased to shorten the squeeze time, the power increases and the equipment cost increases.
[0005]
The present invention has been made in order to solve such a conventional problem, by allowing the preliminary squeeze pressure to be transmitted to a deep portion of a hardly-filled portion where molding sand is difficult to be filled, and by increasing the mold hardness of the hardly-filled portion. is there.
[0006]
[Means for Solving the Problems]
In order to solve the above problems, a structural feature of the invention according to claim 1 is that a squeeze table and a squeeze head which relatively move forward and backward along a molding path are provided, and A board is arranged on the squeeze table, a plurality of squeeze feet are mounted on the squeeze head so as to be able to advance and retreat in the direction of the molding path toward the squeeze table, and the molding sand put in the flask is squeezed. In a mold molding method in which a table and the squeeze head are relatively close to each other and squeezing is performed by the plurality of squeeze feet, the squeeze table and the squeeze head are relatively positioned while maintaining the plurality of squeeze feet under the same conditions. After preliminary squeezing of the molding sand, leave the squeeze foot facing the difficult-to-fill location where the molding sand is difficult to fill. It is projected from the squeeze foot the foundry sand is to fill the preliminary squeezing.
[0007]
A structural feature of the invention according to claim 2 is that a squeeze table and a squeeze head which relatively move forward and backward along a molding path are provided, and a model platen on which a casting flask is placed is arranged on the squeeze table. A plurality of squeeze feet are mounted on the squeeze head so as to be movable in the direction of the molding path, and means for independently moving each squeeze foot toward and away from the squeeze table are provided. In a mold making apparatus for performing squeezing with the plurality of squeeze feet by relatively bringing the squeeze table and the squeeze head closer to the sand, the squeeze table and the squeeze are maintained in a state where the plurality of squeeze feet are maintained under the same conditions. Means for relatively squeezing the foundry sand by bringing the head relatively close to each other; The squeeze foot is is further comprising means for filling pre-squeeze the molding sand is protruded from the rest of the squeeze foot.
[0008]
The structural feature of the invention according to claim 3 is that a squeeze table and a squeeze head which relatively move forward and backward along a molding path are provided, and a model platen on which a flask is placed is arranged on the squeeze table. A plurality of squeeze heads are mounted on the squeeze head so as to be able to advance and retreat in the direction of the molding path toward the squeeze table, and the squeeze head is provided with a plurality of cylinders for accommodating piston parts connected to the squeeze foot. An on-off valve is provided for each of the cylinders, one port of each on-off valve is connected to the corresponding cylinder, and the other port of each on-off valve is connected to a common oil passage, and is put into the flask. The squeeze table and the squeeze head are relatively close to each other in the casting sand to perform squeezing by the plurality of squeeze feet. A state in which a pressure control valve connected to the common oil passage to control the internal pressure of the cylinder communicated with the common oil passage by a valve to a set pressure, and all of the plurality of squeeze feet are maintained under the same conditions. Means for relatively squeezing the molding sand put in the casting frame by relatively approaching the squeeze table and the squeeze head with the plurality of squeeze feet, and after the preliminary squeezing, the molding sand is hardly filled. The on-off valve connected to the cylinder facing the difficult filling point is in a closed state, the other on-off valves are in an open state, and the pressure in the other cylinder is maintained at the pressure set by the pressure control valve. Means for bringing the table sand and the squeeze head relatively close to each other and filling and preliminary squeezing the molding sand charged into the casting flask.
[0009]
According to a fourth aspect of the present invention, in the third aspect, a position detecting device for detecting a relative position between the squeeze table and the squeeze head, or a device for relatively bringing the squeeze table and the squeeze head closer to each other. A pressure detecting device for detecting a pressure generated in the hydraulic drive device, based on the relative position or the pressure detected by the position detecting device or the pressure detecting device, facing a difficult filling portion where molding sand is difficult to be filled. The on-off valve connected to the cylinder is switched to the open state, and the set pressure of the pressure control valve is set to the main squeeze pressure.
[0010]
A structural feature of the invention according to claim 5 is that, in claim 4, a plurality of on-off valves connected to a plurality of cylinders respectively opposed to a plurality of difficult-to-fill locations where casting sand is difficult to be filled are provided by the position detecting device. Or, based on the relative position or the pressure detected by the pressure detection device, the higher the difficulty of filling the foundry sand, the more sequentially switching to the open state later, and when all the on-off valves are in the open state, the set pressure of the pressure control valve is changed to the main squeeze pressure. It is set to.
[0011]
A structural feature of the invention according to claim 6 is that, in any one of claims 3 to 5, the plurality of cylinders are bored in the head body, and on-off valves respectively corresponding to the cylinders are attached to the head body. That is.
[0012]
A structural feature of the invention according to claim 7 is that, in any one of claims 3 to 6, when a pressure in the cylinder is equal to or higher than a setting in a short circuit connecting one port and the other port of each of the on-off valves. That is, a relief valve for releasing pressurized oil to the common oil passage is provided.
[0013]
The constitutional feature of the invention according to claim 8 is that, in the molding method using the mold molding apparatus according to any one of claims 3 to 7, in a state where all of the plurality of squeeze feet are maintained under the same condition. The squeeze table and the squeeze head are relatively close to each other, and the casting sand put into the casting flask is pre-squeezed by the plurality of squeeze foots. The on-off valve connected to the cylinder facing the filling point is in a closed state, and the on-off valves connected to the other cylinders are in an open state, and the squeeze table and the squeeze head are relatively close to each other in the flask. The filling sand is filled and preliminary squeezed, and the open / close valve in the closed state is opened based on the relative position or the pressure detected by the position detection device or the pressure detection device. The switching, the set pressure of the pressure control valve is to set the squeezing pressure.
[0014]
[Action and Effect of the Invention]
In the invention according to claim 1 configured as described above, the squeeze table and the squeeze head are relatively close to each other, and the casting sand is pre-squeezed by a plurality of squeeze feet maintained under the same conditions. When the preliminary squeeze is completed, the squeeze foot that faces the difficult-to-fill location where casting sand is difficult to fill is protruded from the remaining squeeze foot, and pressure is transmitted to the deep portion of the difficult-to-fill location to perform the preliminary filling squeeze.
[0015]
By preliminary squeezing the casting sand first, the hardness of the entire molding sand is increased to some extent within the range where pressure can be transmitted, and in this state, the squeeze foot opposite to the difficult-to-fill portion is protruded to perform preliminary filling squeezing. Dispersion of the pressure generated by the squeezed foot is prevented by the casting sand around the pre-squeezed, the pre-filling squeeze pressure is transmitted to the deep part of the hardly filled part, and the mold hardness at the hardly filled part can be increased. . In addition, by making the entire casting sand suitable hardness by preliminary squeezing, the amount of protrusion of the squeeze foot facing the difficult filling point in the preliminary filling squeeze can be shortened, reducing equipment costs and shortening the time of difficult filling. Pressure can be transmitted to a deep part of the portion to perform filling preliminary squeezing, and it is possible to increase the mold strength of a difficult filling portion which has been insufficiently filled conventionally.
[0016]
In the invention according to claim 2 configured as described above, the squeeze table and the squeeze head are relatively close to each other, and the casting sand is preliminary squeezed by a plurality of squeeze feet maintained under the same conditions. When the preliminary squeeze is completed, the squeeze foot that faces the difficult-to-fill location where casting sand is difficult to fill is protruded from the remaining squeeze foot, and pressure is transmitted to the deep portion of the difficult-to-fill location to perform the preliminary filling squeeze.
[0017]
In addition to the effects of the invention according to claim 1, a low-cost mold molding apparatus capable of transmitting pressure to a deep portion of a difficult-to-fill portion in a short time and increasing the strength of a mold at a difficult-to-fill portion that has been insufficiently filled conventionally. Can be provided.
[0018]
In the invention according to claim 3 configured as described above, the squeeze table and the squeeze head are relatively close to each other while all of the plurality of squeeze foots are maintained under the same condition, and the casting is put into the casting flask. Pre-squeeze the sand with multiple squeeze feet. After the preliminary squeeze, the on-off valve connected to the cylinder facing the difficult filling point where casting sand is difficult to fill is closed, the other on-off valve is open and the pressure in the other cylinder is set by the pressure control valve. The squeeze table and the squeeze head are relatively approached while maintaining the pressure, and the molding sand charged into the flask is pre-squeezed.
[0019]
After the foundry sand is first pre-squeezed to increase the hardness of the foundry sand to a certain extent within the range where pressure can be transmitted, the on-off valve connected to the cylinder facing the difficult filling point is closed and the other cylinders are Prefilling squeezing is performed with the pressure maintained at the set pressure, so the retraction is prevented by the closed on-off valve and the dispersion of pressure generated by the squeeze foot protruding from the other is due to the molding sand around the preliminary squeezed. Thus, pressure is transmitted to the deep portion of the difficult-to-fill portion, and the mold hardness at the difficult-to-fill portion can be increased. In addition, by making the entire casting sand appropriate hardness by preliminary squeezing, it becomes possible to perform preliminary squeezing with a short stroke in a state in which the squeeze foot facing the difficult-to-fill portion is protruded, so that it can be performed in a short time. In addition, it is possible to provide a low-cost mold molding apparatus capable of transmitting pressure to a deep portion of a difficult filling portion to perform filling preliminary squeezing.
[0020]
In the invention according to claim 4 configured as described above, the relative position between the squeeze table and the squeeze head, or the pressure generated in the hydraulic drive device for bringing the squeeze table and the squeeze head relatively close to each other, becomes a predetermined value. Then, all the on-off valves are switched to the open state to end the preliminary filling squeeze, and the set pressure of the pressure control valve is increased to perform the main squeeze. This makes it possible to reliably switch from the preliminary filling squeeze to the main squeeze with a simple configuration.
[0021]
In the invention according to claim 5 configured as described above, in the case where there are a plurality of difficult filling points where the molding sand is difficult to fill, a plurality of opening / closing connected to a plurality of cylinders respectively opposed to the plurality of difficult filling points. The valve is sequentially switched to the open state later in a portion where the difficulty in filling the foundry sand is higher. As a result, it is possible to pre-squeeze the filling with a squeeze foot that is more protruding at a portion where the molding sand is more difficult to fill, so that a plurality of difficult-to-fill portions are filled to a substantially uniform hardness regardless of the difficulty of the molding sand filling. Can be pre-squeezed.
[0022]
In the invention according to claim 6 configured as described above, a plurality of cylinders respectively accommodating the piston portions of the plurality of squeeze feet are bored in the head body of the squeeze head, and the on-off valves corresponding to each of the cylinders are provided. Since it is attached to the head body, the configuration is extremely simple, and the cost can be reduced.
[0023]
In the invention according to claim 7 configured as described above, when the filling preliminary squeezing is performed by closing the on-off valve connected to the cylinder facing the difficult filling point where casting sand is difficult to be filled, the pressure is equal to or higher than the set value. The pressurized oil in the cylinder that has become lost is released to the common oil passage by the relief valve, so that the pressure does not concentrate on a part of the squeeze foot facing the difficult-to-fill point, and the molding sand is locally excessively large. Pre-squeeze filling by pressure can be prevented.
[0024]
In the invention according to claim 8 configured as described above, the squeeze table and the squeeze head are relatively close to each other while the plurality of squeeze feet are all maintained under the same conditions. Pre-squeeze the sand with multiple squeeze feet. When the preliminary squeeze is completed, the on-off valve connected to the cylinder facing the difficult filling location where casting sand is difficult to fill is closed, and the on-off valves connected to other cylinders are open, and the squeeze table and squeeze head are closed. The casting sand is preliminarily squeezed at a pressure set by the pressure control valve by relatively approaching. When the filling preliminary squeeze is completed, the full open / close valve is opened and the set pressure of the pressure control valve is increased to perform the main squeeze.
[0025]
Preliminarily squeeze the casting sand to raise the hardness of the entire casting sand to a certain extent within the range where pressure transmission is possible, and then perform preparatory squeezing, so the preparatory squeeze pressure generated by the squeeze foot protruding from the other is difficult to fill. It is transmitted to the deep part of the place, and the mold hardness of the difficult-to-fill place can be increased. In addition, by setting the entire casting sand to an appropriate hardness by preliminary squeezing, it is possible to perform filling preliminary squeezing with a short stroke, and to transmit pressure to the deep part of difficult filling point in a short time at low cost. A preliminary squeeze can be performed, and the strength of the mold at a difficult-to-fill portion, which has conventionally been insufficiently filled, can be increased.
[0026]
Embodiment
Hereinafter, a first embodiment of a mold making method and apparatus according to the present invention will be described with reference to the drawings. In FIG. 1, reference numeral 1 denotes a squeeze table which is moved up and down by a cylinder device 2 as a hydraulic drive device in a vertical molding path. On the upper surface of the squeeze table 1, a model surface plate 4 on which two cylindrical models 3a and 3b are mounted is fixed. A casting frame 5 and an upper filling frame 6 are placed on the model platen 4 in an overlapping manner, and the foundry sand 7 weighed in the casting frame 5 and the upper filling frame 6 is introduced from a known casting sand supply device. It has become.
[0027]
A squeeze head 9 and a foundry sand supply device are mounted side by side on the lower surface of the shuttle 8. When the shuttle 8 is indexed to a squeeze position by a cylinder device (not shown), the squeeze head 9 faces the squeeze table 1, When indexed to the supply position, the foundry sand supply device faces the squeeze table 1. A plurality of squeeze feet 10 are mounted on the squeeze head 9 so as to be independently movable toward and away from the squeeze table 1 in a molding path direction. A plurality of cylinders 12 are bored in the head body 11 of the squeeze head 9 in the direction of the molding path, and the piston portions 13 of the squeeze foot 10 are slidably fitted and housed, respectively. The squeeze foot 9 is arranged all over the inside of the flask 5 so as to uniformly squeeze the molding sand 7 charged into the flask 5.
[0028]
An on-off valve 14 is mounted on the head body 11 corresponding to each of the cylinders 12. One port 15 of each on-off valve 14 is connected to the corresponding cylinder 12, and the other port 16 of all on-off valves 14 is connected to a common oil passage 17 formed in the head body 11. The common oil passage 17 may be formed of a pipe and fixed on the head main body 11.
[0029]
One port of an electromagnetic pressure control valve 18 is connected to the common oil passage 17, and controls the back pressure of the cylinder 12 connected to the common oil passage 17 by the on-off valve 14 to a set pressure. The other port of the electromagnetic pressure control valve 18 is selectively connected to a hydraulic source 20 and a tank by a switching valve 19. A check valve 23 is connected between the common oil passage 17 and the switching valve 19 in parallel with the electromagnetic pressure control valve 18. Reference numeral 22 denotes a control device, which sends a command signal to each of the on-off valve 14, the electromagnetic pressure control valve 18, and the electromagnetic switching valve 19 based on a signal from a position detection device 21 for detecting the vertical position of the squeeze table 1. The position detection device 21 functions as a position detection device that detects a relative position between the squeeze table 1 and the squeeze head 9.
[0030]
A description will be given of the operation of the embodiment configured as described above and a molding method using the mold molding apparatus according to the embodiment. A casting frame 5 and an upper filling frame 6 are placed on a model platen 4 fixed to the upper surface of the table 1 in a superposed manner. It is thrown into the upper filling frame 6. The shuttle 8 is indexed to the squeeze position, and the squeeze head 9 faces the squeeze table 1. At this time, pressure oil is supplied from the hydraulic pressure source 20 to all the cylinders 12 through the switching valve 19, the check valve 23, and all the on-off valves 16 opened by the deenergization of the solenoid, and all the squeeze feet 10 are projected to the forward end. ing.
[0031]
Next, as shown in FIG. 2, the control device 22 applies a control current corresponding to the preliminary squeeze pressure to the linear solenoid of the electromagnetic pressure control valve 18 and switches the switching valve 19 to put the electromagnetic pressure control valve 18 in the tank. Communicate.
[0032]
In this state, the squeeze table 1 is raised toward the squeeze head 9 by the cylinder device 2, and the entire squeeze foot 10 is brought into contact with the molding sand 7 put into the casting frame 5 and is pressed upward. The pressure in all the cylinders 12 communicated with each other rises at an equal pressure, and when the pressure rises to the preliminary squeeze pressure, the pressure is discharged to the tank via the electromagnetic pressure control valve 18 and the switching valve 19. As described above, due to the relative approach between the squeeze table 1 and the squeeze head 9, the casting sand 7 charged into the casting flask 5 is pre-squeezed by the plurality of squeeze feet 10 maintained at the same pressure under the same conditions. (FIG. 3). All of the plurality of squeeze feet 10 are maintained under the same conditions by the on-off valve 14 that is fully opened by the control device 22, the electromagnetic pressure control valve 18 whose back pressure is set to the preliminary squeeze pressure, the cylinder device 2, and the like. The squeeze table 1 and the squeeze head 9 are relatively close to each other, and a means for preliminary squeezing the molding sand 7 put into the casting flask 5 by the plurality of squeeze feet 10 is provided.
[0033]
When the position detecting device 21 detects that the squeeze table 1 has been raised to the preliminary squeeze end position, the opening and closing connected to the cylinder 12 facing the difficult filling point where the molding sand 7 is difficult to fill in the casting flask 5. The valve 14 is switched to the closed state by energizing the solenoid. In FIG. 2, the inner peripheral surfaces of the cylindrical models 3a and 3b are bottlenecks surrounded by high walls and are difficult-to-fill locations where casting sand is difficult to fill, and house the piston portion of the squeeze foot 10 facing the model 3a. The three on-off valves 14 respectively connected to the two cylinders 12 accommodating the piston portions of the two squeeze feet 10 that are half-opposed to the cylinder 12 and the model 3b, respectively, are switched to the closed state. The discharge of the pressurized oil is blocked, and the retraction of the squeeze foot 10 is restricted. The three on-off valves 14 connected to the cylinder 12 that stores the squeeze foot 10 facing the difficult filling location are registered in the control device 22 in advance. When a plurality of tall models are fixed on the model platen 4 at narrow intervals, a bottleneck portion sandwiched between the tall models becomes a difficult filling point where the molding sand is difficult to be filled.
[0034]
The squeeze table 1 is further raised toward the squeeze head 9 by the cylinder device 2, and the squeeze foot 10 in which the switching valve 14 is maintained in the open state is configured such that the pressure oil in the cylinder 12 controls the electromagnetic pressure control valve 18 and the switching valve 19. The squeeze foot 10 with the switching valve 14 closed is blocked from discharging the pressurized oil in the cylinder 12, so that the squeeze foot 10 is prevented from retreating and is protruded by another squeeze foot 10. I do. As the squeeze table 1 rises, the inside of the cylindrical models 3a and 3b is filled with molding sand 7 from a squeeze foot 10 protruding from other squeeze feet, and is pre-squeezed for filling (FIG. 4). The opening / closing valve, the electromagnetic pressure control valve 18, the cylinder device 2, and the like, a part of which is in a closed state and the remaining part is opened by the control device 22, are opposed to the difficult-to-fill portion where the molding sand 7 is difficult to fill after the preliminary squeezing. The on-off valve 14 connected to the cylinder 12 is closed, the other on-off valve 14 is opened, and the pressure in the other cylinder 12 is maintained at the pressure set by the electromagnetic pressure control valve 18 so that the squeeze table 1 The squeeze head 9 is relatively close to the squeeze head 9 to fill and squeeze the casting sand 7 charged into the casting flask 5.
[0035]
The cylindrical model 3b is shorter than the model 3a, and it is difficult to fill the molding sand 7 in the deep part, and the filling of the molding sand is difficult. In the case where there are a plurality of difficult filling points where the difficulty of filling the molding sand is different as described above, the molding sand 7 is filled first in the interior of the model 3a having the low difficulty of filling the molding sand. When the position detecting device 21 detects that the squeeze table 1 has risen to the position where the filling of the casting sand into the model 3a is completed, the on-off valve 14 connected to the cylinder 12 facing the model 3a is opened. Can be switched. The subsequent rise of the squeeze table 1 restricts the two squeeze feet 10 against the model 3b, which has a high level of difficulty in filling the casting sand, to fill the inside of the cylindrical model 3b with the casting sand 7 (FIG. 5). .
[0036]
When the position detecting device 21 detects that the squeeze table 1 has risen to the position where the filling of the casting sand into the model 3b is completed, the on-off valve 14 connected to the cylinder 12 facing the model 3b is opened. Then, a control current corresponding to the final squeeze pressure which is the main squeeze pressure is applied to the linear solenoid of the electromagnetic pressure control valve 18. The position of the squeeze table 1 where the filling of the casting sand into the interior of the model 3a or 3b is completed is set by repeating the test.
[0037]
In this state, the squeeze table 1 is raised toward the squeeze head 9 by the cylinder device 2, and all the squeeze feet 10 finally squeeze the molding sand 7 as the main squeeze at the same pressure. When the position detecting device 21 detects that the squeeze table 1 has risen to the squeeze completed position, the control device 22 lowers the squeeze table 1 to the lower end by the cylinder device 2 as shown in FIG. The solenoid of the switching valve 19 is de-energized while the solenoid of the on-off valve 14 is de-energized. Thus, the pressure oil is supplied from the hydraulic pressure source 20 to the cylinder 12 via the check valve 23, and the entire squeeze foot 10 is returned to the forward end.
[0038]
FIG. 8 is a graph comparing the mold strength when a mold of a cylindrical model 3 having a height of 70 mm and an inner diameter of 75 mm is molded by the present method with that of a conventional method. A change in the mold strength of the bottom central portion B of the cylindrical model 3 when the protrusion amount A of the squeeze foot 10 facing the cylindrical model 3 from the other squeeze foot 10 (see FIG. 9) is variously changed is shown. ing. As is clear from FIG. 8, when the preliminary squeeze is performed as in the present invention before the squeeze foot 10 facing the cylindrical model 3 that is difficult to be filled with the casting sand 7 and the preliminary squeeze is performed as in the present invention, the protrusion amount A is reduced. In the case of 75 mm and 100 mm, the mold strength is dramatically increased to 175% and 185%. As described above, according to the present invention, even when the protrusion amount A is small, it is possible to satisfactorily fill the difficult-to-fill portion with the molding sand, and it is possible to effectively perform the preliminary squeeze with a short stroke.
[0039]
As in the second embodiment shown in FIG. 10, when the pressure in each cylinder 12 becomes equal to or higher than a setting in the short circuit 24 connecting the one port 15 and the other port 16 of each on-off valve 14, the pressure oil flows to the common oil passage 17 It is preferable to connect the relief valves 25 to be released respectively. Accordingly, when the opening / closing valve 14 connected to the cylinder 12 facing the difficult filling location where the molding sand 7 is difficult to fill is closed and the preliminary filling squeezing is performed, the pressure oil in the cylinder 12 in which the pressure is equal to or higher than the set value is set. Is released to the common oil passage 17 by the relief valve 25, so that the pressure does not concentrate on a part of the squeeze foot 10 facing the difficult filling point, and the casting sand 17 is locally filled with excessive pressure. Squeezing can be prevented.
[0040]
In the third embodiment shown in FIG. 11, a model platen 4 is fixed on a carrier plate 30 placed on a squeeze table 1, and a lower filling frame 31 surrounds the model platen 4 on the carrier plate 30 and moves up and down. It is movably mounted. Cylinder devices 32 are provided at four corners of the squeeze table 1, and the lower filling frame 10 is moved between a raised position and a retracted position by raising and lowering a piston rod of the cylinder device 32. When the squeeze table 1 is raised by the cylinder device 2 in a state where the lower filling frame 31 is raised to the raised position by the cylinder device 32, the casting frame 5 supported on the roller conveyor 34 is placed on the upper surface of the lower filling frame 31. The casting frame 5 is placed at the casting frame delivery position, the upper filling frame 6 is brought into contact with the upper surface of the casting frame 5, and the squeeze table 1 is temporarily stopped at the casting sand charging position shown in FIG. The casting sand 7 is put into the frame 5 and the upper filling frame 6.
[0041]
When the casting sand 7 is charged, a control current corresponding to the preliminary squeeze pressure is applied to the solenoid of the electromagnetic pressure control valve 18, and the squeeze table 1 is moved toward the squeeze head 9 by the cylinder device 2 with the full on-off valve 14 opened. All the squeeze feet 10 are evenly pre-squeezed from the casting sand 7 charged into the casting flask 5. When the position detecting device 21 detects that the preliminary squeeze has been completed, the on-off valve 14 connected to the cylinder 12 facing the difficult filling location where the molding sand 7 is difficult to fill in the casting flask 5 is switched to the closed state. . The squeeze table 1 is further raised toward the squeeze head 9 by the cylinder device 2, the switching valve 14 is closed, and the retreat is restricted. Squeeze. When the completion of the filling preliminary squeeze is detected by the position detecting device 21, the fully open / close valve 14 is opened, and a control current corresponding to the model surface side squeeze pressure is applied to the linear solenoid of the electromagnetic pressure control valve 18. You. The squeeze table 1 is raised in a state in which the rise of the upper filling frame 6 is restricted by the cylinder device 33 provided on the squeeze head 9 until the contact surface of the lower filling frame 31 with the casting frame 5 retreats to the retreat position. Then, the casting sand 7 is squeezed as the main squeeze. When the squeeze on the model side is completed, a control current corresponding to the final squeeze pressure is applied to the linear solenoid of the electromagnetic pressure control valve 18, the restriction on raising the upper filling frame 6 by the cylinder device 33 is released, and the squeeze table 1 is raised. The entire squeeze foot 10 finally squeezes the casting sand 7. When the squeeze table 1 is located at the rising end and the final squeeze is completed, the squeeze table 1 is lowered by the cylinder device 2, and the casting flask 6 is transferred onto the roller conveyor 34 at the casting flask delivery position to remove the models 3a and 3b. After releasing the mold, it is stopped at the lower end.
[0042]
In the fourth embodiment shown in FIGS. 13 and 14, the squeeze head 35 is fixed to the machine frame so as to face the squeeze table 1, and a plurality of fitting holes 36 are formed in the squeeze head 35. A squeeze foot 37 is fitted to 36 so as to be slidable in the vertical direction. A cylinder device 38 is fixed to the upper surface of the squeeze head 35 so as to close each fitting hole 36, and a piston of each cylinder device 38 is connected to each squeeze foot 37 and moves up and down independently of each other. On the outer peripheral portion of the squeeze head 35, a plurality of casting sand supply holes 39 are formed in a zone surrounding all the fitting holes 36 and all the cylinder devices 38. The outer peripheral wall and the inner peripheral wall of the blow passage 40 are fixed at the peripheral edge.
[0043]
The squeeze table 1 is raised by the cylinder device 2, and the casting frame 5 and the upper filling frame 6, which are superimposed on the model platen 4 fixed to the squeezing table, are raised, and the upper filling frame 6 is fitted on the outer periphery of the squeeze head 35. If they match, the squeeze table 1 is temporarily stopped. Each squeeze foot 37 is retracted by each cylinder device 38 to a retracted end where each lower end surface is aligned with the lower surface of the squeeze head 35. In this state, the molding sand 7 is charged into the casting frame 5 and the upper filling frame 6 by compressed air through the blow passage 40 (FIG. 13).
[0044]
Next, the squeeze table 1 is raised toward the squeeze head 35 by the cylinder device 2, and the entire squeeze foot 37 uniformly squeezes the molding sand 7 charged into the casting frame 5. When the position detecting device detects that the squeeze table 1 has risen to the preliminary squeeze end position, the squeeze foot 37 facing the hardly-filled portion where the molding sand 7 is difficult to fill in the casting flask 5 is advanced by the cylinder device 38. Then, the casting sand 7 is filled into the hardly-filled portion, and the filling is pre-squeezed (FIG. 14). Thereafter, the squeeze table 1 is raised toward the squeeze head 35 by the cylinder device 2, and all the squeeze feet 37 finally squeeze the molding sand 7 at the same pressure. A pressure detecting device for detecting the pressure generated in the cylinder device 2 for raising and lowering the squeeze table 1 is provided, and the start time and the end time of the filling preliminary squeeze are determined based on the pressure detected by the pressure detecting device. Is also good.
[0045]
In each of the above embodiments, the squeeze table 1 is moved up and down by the cylinder device 2 so that the squeeze table 1 and the squeeze head 9 are relatively close to each other. You may make it go up and down.
[0046]
In the first to third embodiments, when it is detected that the squeeze table 1 has risen to the position where the filling of the difficult-to-fill portion with the molding sand has been completed, the full on-off valve 14 is opened to perform the filling preliminary squeeze. Although completed, a pressure detecting device for detecting the pressure generated in the cylinder device 2 for raising and lowering the squeeze table 1 may be provided, and the preliminary filling squeeze may be completed based on the pressure detected by the pressure detecting device. Good.
[0047]
In the above-described embodiment, all the on-off valves 14 connected to the plurality of cylinders 12 into which the piston portions of the plurality of squeeze feet 10 are fitted are opened to maintain the pressure in all the cylinders 12 at the preliminary squeeze pressure. As a result, the casting sand 7 is pre-squeezed while maintaining the plurality of squeeze feet 10 under the same conditions. By raising 1 to the preliminary squeeze end position, the plurality of squeeze feet 10 may be maintained under the same conditions, and the casting sand 7 may be pre-squeezed.
[0048]
Further, in the above embodiment, the entire on-off valve 16 is opened after the casting sand 7 is charged, and the on-off valve 14 connected to the cylinder 12 opposed to the difficult filling location where the casting sand 7 is difficult to be filled after the preliminary squeeze is completed is closed. When the casting sand 7 is charged, the on-off valve 14 connected to the cylinder 12 facing the difficult filling point is closed and the other on-off valves 14 are opened. Until the pre-squeeze pressure set by the electromagnetic pressure control valve 18 is reached, the molding sand 7 is pre-squeezed under the same conditions that the entire squeeze foot 10 is maintained at the forward end, and the pressure in the cylinder 12 is reduced to the pre-squeeze pressure. Is reached, the squeeze foot 10 in which the on-off valve 14 is closed protrudes to perform the preparatory filling squeeze.
[0049]
In the above-described embodiment, the lower end surfaces of the plurality of squeeze feet 10 located at the forward end are at the same height. For example, the lower end surface position of the squeeze foot 10 near the peripheral wall of the flask 5 may be slightly lowered. Even if the shape of a part of the squeeze foot 10 is changed in this way, the same condition is maintained as long as the pressure in each cylinder 12 at the time of the preliminary squeeze is made equal or the preliminary squeeze is performed by restricting the retreat of all the squeeze feet. Preliminary squeeze is performed by the plurality of squeeze foots.
[Brief description of the drawings]
FIG. 1 is a view showing a first embodiment of a mold making apparatus according to the present invention.
FIG. 2 is a view showing a state when casting sand is charged.
FIG. 3 is a diagram showing a state at the time of preliminary squeezing.
FIG. 4 is a view showing a state in which a tall cylindrical model is pre-filled and squeezed.
FIG. 5 is a view showing a state in which a short cylindrical model is filled and pre-squeezed.
FIG. 6 is a diagram showing a final squeezed state.
FIG. 7 is a diagram showing a state in which squeezing is completed.
FIG. 8 is a graph comparing the strengths of the molds formed by the method of the present invention and the conventional method.
FIG. 9 is a diagram showing a protrusion amount A and a mold strength measurement point B shown in the graph of FIG.
FIG. 10 is a diagram showing a second embodiment.
FIG. 11 is a diagram showing a third embodiment.
FIG. 12 is a view showing a state in which molding sand of the third embodiment has been charged.
FIG. 13 is a view showing a fourth embodiment.
FIG. 14 is a view showing a state in which preliminary filling squeezing is performed according to a fourth embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Squeeze table, 2 ... Cylinder device, 3a, 3b ... Model, 4 ... Model platen, 5, ... Cast frame, 6 ... Top frame, 7 ... Cast sand, 8 ... Shuttle, 9,35 ... Squeeze head, 10, 37 ... squeeze foot, 11 ... head body, 12 ... cylinder, 13 ... piston part, 14 ... open / close valve, 15 ... one port, 16 ... other port, 18 ... electromagnetic pressure control valve (pressure control valve), 19 ... Switching valve, 20 hydraulic pressure source, 21 position detecting device, 22 control device, 23 check valve, 24 short circuit, 25 relief valve, 30 carrier plate, 31 lower frame, 32, 33 cylinder Device, 39: Foundry sand supply hole, 40: Blow passage.

Claims

A squeeze table and a squeeze head that relatively move forward and backward along a molding path are provided, a model platen on which a casting flask is placed is arranged on the squeeze table, and a plurality of squeeze feet are mounted on the squeeze head. Squeezing is performed by the plurality of squeeze feet by relatively moving the molding sand put into the casting frame between the squeeze table and the squeeze head toward the molding path. In the mold making method, the squeeze table and the squeeze head are relatively close to each other while the plurality of squeeze feet are maintained under the same conditions, and the molding sand is pre-squeezed. The squeeze foot opposite to the squeeze foot is protruded from the remaining squeeze foot, and the casting sand is filled and pre-squeezed. Casting mold making method comprising and.

A squeeze table and a squeeze head that relatively move forward and backward along a molding path are provided, a model surface plate on which a casting flask is placed is disposed on the squeeze table, and a plurality of squeeze feet are mounted on the squeeze head in the molding path. A means for independently moving each squeeze foot toward and away from the squeeze table, and allowing the molding sand charged into the flask to move the squeeze table and the squeeze head relative to each other. The squeeze table and the squeeze head are relatively close to each other while the plurality of squeeze feet are maintained under the same conditions, and the molding sand is reserved. Squeeze means and squeeze foot facing the difficult filling point where casting sand is difficult to fill Casting mold making system, characterized in that it is projected from over preparative comprising means for filling pre-squeeze the molding sand.

A squeeze table and a squeeze head that relatively move forward and backward along a molding path are provided, a model platen on which a casting flask is placed is arranged on the squeeze table, and a plurality of squeeze feet are mounted on the squeeze head. The squeeze head is provided with a plurality of cylinders each of which accommodates a piston portion connected to the squeeze foot and is provided with an on-off valve corresponding to each of the cylinders. One port of each on-off valve is connected to a corresponding cylinder, the other port of each on-off valve is connected to a common oil passage, and the molding sand charged into the casting flask is used to relatively move the squeeze table and the squeeze head. In the mold making apparatus for performing squeezing with the plurality of squeeze feet by closely approaching each other, before the squeeze valve is communicated with the common oil passage by the on-off valve. The pressure control valve connected to the common oil passage for controlling the internal pressure of the cylinder to a set pressure, and the squeeze table and the squeeze head are relatively moved while all of the plurality of squeeze feet are maintained under the same conditions. Means for preliminary squeezing the molding sand put into the flask by closely approaching with the plurality of squeeze feet, and after the preliminary squeezing, the molding sand was connected to a cylinder facing a hardly-filled portion where molding sand is difficult to be filled. The squeeze table and the squeeze head are relatively close to each other while the on-off valve is closed and the other on-off valves are opened and the pressure in the other cylinder is maintained at the pressure set by the pressure control valve. Means for filling and preliminary squeezing the casting sand charged into the casting flask.

4. The pressure detecting device according to claim 3, wherein the position detecting device detects a relative position between the squeeze table and the squeeze head, or a pressure generated in a hydraulic drive device for causing the squeeze table and the squeeze head to approach each other relatively. Providing a device, based on the relative position or pressure detected by the position detection device or the pressure detection device, switching the on-off valve connected to the cylinder facing the difficult filling location is difficult to fill the molding sand, And a setting pressure of the pressure control valve is set to a main squeeze pressure.

5. The relative position or pressure detected by the position detection device or the pressure detection device according to claim 4, wherein a plurality of on-off valves connected to a plurality of cylinders respectively facing the plurality of difficult-to-fill locations where the molding sand is difficult to fill. The mold forming apparatus is characterized in that, as the difficulty of filling the foundry sand increases, the state is sequentially switched to the open state later, and when the full on-off valve is opened, the set pressure of the pressure control valve is set to the main squeeze pressure.

6. The mold molding apparatus according to claim 3, wherein the plurality of cylinders are bored in the head body, and on-off valves respectively corresponding to the cylinders are attached to the head body.

7. The relief valve according to claim 3, wherein a short-circuit circuit connecting one port and the other port of each of the on-off valves is provided with a relief valve that releases pressurized oil to the common oil passage when the pressure in the cylinder exceeds a set value. A mold making apparatus.

8. The molding method using the mold molding apparatus according to any one of claims 3 to 7, wherein the squeeze table and the squeeze head are relatively close to each other while all of the plurality of squeeze foots are maintained under the same conditions. The pre-squeeze of the molding sand put into the casting flask by the plurality of squeeze foots, and after the preliminary squeezing is completed, the opening / closing valve connected to the cylinder opposed to the difficult filling portion where the molding sand is difficult to be filled. Is closed, the on-off valve connected to the other cylinder is in an open state, the squeeze table and the squeeze head are relatively close to each other, and the casting sand charged into the flask is pre-squeezed, A closed on-off valve is switched to an open state based on the relative position or the pressure detected by the position detection device or the pressure detection device, and the set pressure of the pressure control valve is set. The casting mold making method characterized by setting this squeezing pressure.