JP3644825B2

JP3644825B2 - Superplastic forming device

Info

Publication number: JP3644825B2
Application number: JP21488898A
Authority: JP
Inventors: 勉田形
Original assignee: Furukawa Sky Aluminum Corp
Current assignee: Furukawa Sky Aluminum Corp
Priority date: 1998-07-14
Filing date: 1998-07-14
Publication date: 2005-05-11
Anticipated expiration: 2018-07-14
Also published as: JP2000024724A

Description

【０００１】
【発明の属する技術分野】
この発明は特定の高温度域で超塑性を示す各種の金属板（超塑性金属板）を超塑性成形するための装置に関し、特に複数枚の超塑性金属板を積層してその超塑性金属板間に気体圧力を加えて各超塑性金属板をブロー成形させるための装置に関するものである。
【０００２】
【従来の技術】
近年、例えば２５０〜３５０℃程度あるいは３５０〜５５０℃程度の所定の高温域（超塑性温度域）において著しく大きい伸びを示す超塑性金属材料が種々開発されており、複雑な形状の成形品や変形量の大きい成形品、例えば航空機部品や自動車部品、精密機器などに適用されつつある。このような超塑性金属材料としては、アルミニウム合金系として例えばＡｌ−Ｚｎ系合金、Ａｌ−Ｚｎ−Ｍｇ−Ｃｕ系合金、Ａｌ−Ｍｇ−Ｍｎ系合金などが知られ、そのほかチタン合金系の材料、ステンレス鋼系の材料なども知られている。
【０００３】
ところで超塑性金属板を用いて実際に超塑性温度域で成形するための代表的な方法としては、加圧気体の圧力を利用してブロー成形する方法がある。このようなブロー成形により超塑性金属板を超塑性成形するための具体的な方法としては、上金型と下金型との間に１枚の超塑性金属板を挟んで超塑性温度域に加熱保持した状態で一方の金型の内面と超塑性金属板との間の空間（キャビティ）に不活性ガスなどの加圧気体を導入し、その圧力により超塑性金属板を他方の金型の内面へ向けて変形させる方法が一般的であったが、最近では上金型と下金型との間に２枚の超塑性金属板を積層して挟持した状態で超塑性温度域に保持し、その２枚の超塑性金属板間に加圧気体を導入して、２枚の超塑性金属板を同時にブロー成形させる方法が、例えば特開平７−１０５０号において提案されている。このような方法においては、２枚の超塑性金属板を同時にブロー成形することにより、成形工程の生産性を向上させることができるばかりでなく、２枚の積層金属板間に中空部を有する成形部品を簡単な工程で製造できるなどの利点がある。
【０００４】
ところで上述のように積層された２枚の超塑性金属板を同時にブロー成形する方法では、その積層された超塑性金属板の間に加圧気体を導入しなければならないが、加圧気体導入のための具体的手段としては、前述の特開平７−１０５０号の提案では図８に示されている構造と図９に示される構造との２種の構造が開示されている。これらの加圧気体導入のための構造について次に説明する。
【０００５】
図８において、上金型１Ａおよび下金型１Ｂとの間には２枚の超塑性金属板３Ａ，３Ｂが積層された状態で挟持されている。そして上金型１Ａの周縁部下面および下金型１Ｂの周縁部上面の所定の位置には、上金型１Ａ、下金型１Ｂによって区画されるキャビティ７に通じる挿入溝８が形成されており、この挿入溝８の部分において外部から加圧気体導入管（プラグ）９が２枚の超塑性金属板３Ａ，３Ｂ間に差し込まれている。そして加圧気体導入管９の後方部分（上金型１Ａ、下金型１Ｂよりも外側の部分）には外周方向へ突出する鍔１１が形成されており、一方下金型１Ｂの外面側にはブラケット１３が突設されており、このブラケット１３には加圧気体導入管９の鍔部１１の端縁部に係合する段差部１３Ａが形成されている。
【０００６】
このような図８に示される構造では、加圧気体導入管９を介して超塑性金属板３Ａ，３Ｂ間に加圧気体を吹込んで、その圧力により超塑性金属板３Ａ，３Ｂを図８中の鎖線で示すように変形させるのであるが、この際、加圧気体導入時の反力が加圧気体導入管９に加わり、その加圧気体導入管９が上金型１Ａ、下金型１Ｂから抜け出て外部へ飛び出すおそれがある。そこで図８に示す装置では、ブラケット１３の段差部１３Ａによって加圧気体導入管９の鍔部１１を受けて、加圧気体導入管９が上述の反力により抜け出ることを防止している。
【０００７】
一方図９に示される構造においては、２枚の超塑性金属板３Ａ，３Ｂのうち、例えば上面側に位置する超塑性金属板３Ａの周縁部板面に貫通孔１７を形成しておき、また上金型１Ａの内部には前記貫通孔１７に対応する位置に加圧気体導入路１９を貫通形成しておき、さらに上金型１Ａと下金型１Ｂの周縁部間の所定位置（前記貫通孔１７、加圧気体導入路１９に対応する位置）に凹窪部１５Ａ，１５Ｂを形成しておく。そして上金型１Ａと下金型１Ｂとの間に２枚の超塑性金属板３Ａ，３Ｂを積層して挟持させるにあたり、前記凹窪部１５Ａ，１５Ｂに対応する位置にコマ状部材２１を挟み込む。このコマ状部材２１は上側の超塑性金属板３Ａの貫通孔１７に対応する部分から上金型１Ａ、下金型１Ｂ内側のキャビティ７の側へ向けて開口する連通路２３を形成したものである。
【０００８】
このような図９に示される構造においては、上金型１Ａの内部に形成された加圧気体導入路１９、上側の超塑性金属板３Ａに形成された貫通孔１７、コマ状部材２１の連通路２３を介して加圧気体を２枚の超塑性金属板３Ａ，３Ｂ間に吹込み、その圧力によってキャビティ７内で２枚の超塑性金属板３Ａ，３Ｂをブロー成形させることができる。ここで、コマ状部材２１には加圧気体導入時の反力が加わるが、超塑性金属板３Ａ，３Ｂを上金型１Ａ、下金型１Ｂ間に挟持させるにあたっては、上金型１Ａ、下金型１Ｂ間の型締め力により超塑性金属板３Ａ，３Ｂはコマ状部材２１の部分でそのコマ状部材２１および凹窪部１５Ａ，１５Ｂに沿って湾曲状に窪み変形するから、前述の反力によってはコマ状部材２１が外側へ抜け出てしまうことはない。
【０００９】
【発明が解決しようとする課題】
従来の超塑性ブロー成形装置における加圧気体導入構造では次のような問題があった。
【００１０】
先ず図８に示される構造では、加圧気体導入管９の鍔部１１をブラケット１３の段差部１３Ａが受けることによって、加圧気体導入時の反力により加圧気体導入管９が抜け出ようとすることを防止しており、確かにこのような構造であれば加圧気体導入時の反力による外部への加圧気体導入管９の飛び出しの防止は可能であるが、実際の超塑性ブロー成形時には、加圧気体導入管９の鍔部とブラケット１３の段差部１３Ａとの係合が外れて加圧気体導入管９が金型外部へ抜け出てしまうことがあり、また加圧気体導入管９が金型外部へ飛び出さないまでも、抜け出る方向へ移動して加圧気体導入管９とこれを挟む上下の超塑性金属板３Ａ，３Ｂとの間に隙間が生じて、その部分でキャビティ７内の圧力が漏れてしまって、超塑性金属板３Ａ，３Ｂを確実に成形させ得なくなる事態が生じるおそれがある。
【００１１】
すなわち、既に述べたように超塑性成形は、２５０〜３５０℃程度あるいは３５０〜５５０℃程度の高温の超塑性温度域で行なう必要があり、このような高温では金型１Ａ，１Ｂが熱膨張し、また下金型１Ｂに一体化されているブラケット１３も熱膨張するが、加圧気体導入管９は、内側を通常は室温の加圧気体が流れているためほとんど熱膨張せず、その結果加圧気体導入管９の鍔部１１とブラケット１３の段差部１３Ａとの間に隙間が生じ、加圧気体導入管９がキャビティ７内への導入気体の反力によって外部へ抜け出る方向へ移動することになる。そしてこのようにして加圧気体導入管９が若干でも移動すれば、加圧気体導入管９とこれを上下に挟んでいる超塑性金属板３Ａ，３Ｂとの間に隙間が生じ、その隙間からキャビティ７内に導入した加圧気体が漏れてしまう。またこのとき加圧気体導入管９と上下の超塑性金属板３Ａ，３Ｂとの間の隙間から外部へ漏れる加圧気体は、加圧気体導入管９の先端のノズルから吹込んだばかりの未だ温度上昇していない低温のものであることが多く、その低温の漏洩気体により隙間の部分で超塑性金属板３Ａ，３Ｂが冷却されて収縮し、その結果隙間がより一層拡大して加圧気体導入管９が抜け出やすくなり、最悪の場合は加圧気体導入管９が外れてしまうことがある。また加圧気体導入管９が外れないまでも、前述のような加圧気体導入管９と超塑性金属板３Ａ，３Ｂとの間の隙間の拡大により、その隙間を通って漏洩する気体が多くなり、キャビティ７内に有効な加圧力が加えられなくなって、成形が困難となってしまうことがある。
【００１２】
一方図９に示される従来構造では、加圧気体導入時の反力はコマ状部材２１に加わるが、このコマ状部材２１は上下の金型１Ａ，１Ｂの凹窪部１５Ａ，１５Ｂによって形成される超塑性金属板３Ａ，３Ｂの窪み部分に配置されているため、コマ状部材２１が外部へ抜け出したり、そのコマ状部材２１と超塑性金属板３Ａ，３Ｂとの間の隙間から外部へ加圧気体が漏洩したりしてしまったりするおそれは少ない。しかしながら図９に示す構造の場合、超塑性金属板３Ａに予め貫通孔１７を形成しておかなければならず、しかもその貫通孔１７は、上金型１Ａの加圧気体導入路１９の開口位置に正確に対応させるように位置決めしなければならず、そのため貫通孔１７の形成にかなりの手間と時間を要するのが実情である。さらに、ブロー成形作業の開始に先立っては、コマ状部材２１を、上金型１Ａ、下金型１Ｂの凹窪部１５Ａ，１５Ｂに正確に対応する位置に正しい姿勢で配置しなければならないが、このようにコマ状部材２１を正確な位置に正しい姿勢で配置することは、実際の作業では極めて困難である。すなわち、ブロー成形の準備作業としては、先ず下金型１Ｂの上に一方の超塑性金属板３Ｂを載置し、次いでコマ状部材２１を一方の超塑性金属板３Ｂの上の所定の位置（下金型１Ｂの凹窪部１５Ｂに対応する位置）に載置し、その後他方の超塑性金属板３Ａを載置して型締めを行ない、これによって中間にコマ状部材２１を挟んだ状態で２枚の超塑性金属板３Ａ，３Ｂを上下の金型１Ａ，１Ｂ間に挟持させることになるが、下側の超塑性金属板３Ｂ上にコマ状部材２１を載置する段階では、下金型１Ｂの凹窪部１５Ｂは超塑性金属板３Ｂによって隠されているため、その凹窪部１５Ｂの位置を目視により確認することができず、そのためコマ状部材２１の正確な位置決めは極めて困難であった。しかも前述のような準備作業は、一般にブロー成形のための高温度域に予め金型を予熱した状態の高温雰囲気で行なう必要があり、このような高温雰囲気中でコマ状部材を正しい姿勢で正確な位置に配置することは極めて困難と言わざるを得ず、時間と手間を要し、生産性を阻害する大きな原因となる。したがって前述のようなコマ状部材を用いる方式は、実操業には適用し難い、と言わざるを得ない。
【００１３】
この発明は以上の事情を背景としてなされたもので、上述の諸問題を解決し得る加圧気体導入構造を備えたブロー成形用の超塑性成形装置を提供することを目的とするものである。すなわちこの発明の超塑性成形装置は、従来の図８に示される加圧気体導入構造に準じて、積層させた超塑性金属板間にその端縁側から加圧気体導入管のノズル部を挟み込む構造としながらも、加圧気体導入管が抜け出る方向へ移動することを確実に防止し、これにより加圧気体導入管が金型外部へ外れてしまったり、加圧気体導入管とそれを挟む超塑性金属板との間に隙間が生じて加圧気体が漏洩して、成形が困難となってしまうような事態が発生することを確実に防止することを目的としている。
【００１４】
【課題を解決するための手段】
前述のような課題を解決するため、この発明は、基本的には、上下の金型間に複数枚の超塑性金属板をその周縁部が上下の金型の周縁部に挟まれるように積層して挟持し、上下の金型の端縁側から超塑性金属板間に加圧気体導入管の先端部を挿入し、その加圧気体導入管を介して超塑性金属板間へ加圧気体を導入して超塑性金属板をブロー成形するようにした超塑性成形装置において、前記加圧気体導入管の先端部に、金型外方から金型内方へ向う方向に沿って径が拡大する外径拡大部が形成され、かつ上下の金型の周縁部には、加圧気体導入管における外径拡大部よりも金型外方寄りの基管部分を、間に超塑性金属板を介在させた状態で挟む凹部が形成され、その凹部における金型内方側の端縁により加圧気体導入管が金型外方へ向けて移動することを阻止するように構成したことを特徴とするものである。
【００１５】
このような超塑性成形装置においては、上下の金型の周縁部に形成された凹部の金型内方側の端縁によって加圧気体導入管が金型外方へ向けて移動することが阻止される。すなわち、加圧気体導入管に対して金型外方への力が加わっても、その加圧気体導入管の先端部の外径拡大部における金型外方側の外面が超塑性金属板を介して間接的に前記凹部の端縁に接し、この凹部端縁によって加圧気体導入管の移動が阻止される。したがって加圧気体導入管を介して超塑性金属板間へ加圧気体を吹込む際の反力が加圧気体導入管に加わっても、加圧気体導入管が上下の金型間から抜け出たり、また抜け出ないまでも、加圧気体導入管の移動に起因してその加圧気体導入管とそれを挟む上下の超塑性金属板との間に隙間が生じることを防止でき、ひいては加圧気体がその隙間から漏洩することを防止できる。ここで、加圧気体導入管の移動は、上下の金型の周縁部間で阻止しているため、上下の金型の熱膨張による変位の影響を受けることなく、加圧気体導入管の移動を確実に阻止することができる。
【００１６】
また請求項２の発明は、請求項１に記載の超塑性成形装置において、前記加圧気体導入管を金型内方から外方へ向って付勢するための付勢手段を備えていることを特徴とするものである。
【００１７】
このように請求項２の発明の超塑性成形装置においては、加圧気体導入管が金型内方から金型外方へ向って付勢されるため、加圧気体導入管の先端部の外径拡大部の金型外方の外面を常時強制的に金型周縁部の凹部端縁へ押し当てる（但し中間に超塑性金属板を介在させて）ことになり、そのため加圧気体導入管の位置が常に定位置に固定・維持されるから、金型外方への加圧気体導入管の移動をより確実に防止することができる。
【００１８】
さらに請求項３の発明は、請求項１に記載の超塑性成形装置において、前記加圧気体導入管における金型外側の部分にフランジ部が形成され、また下金型には前記加圧気体導入管を受けるための固定基台が下金型から突出するように形成され、その固定基台には、加圧気体導入管におけるフランジ部よりも金型寄りの部位が上方から遊嵌される凹部を有する突壁部が形成され、さらに前記加圧気体導入管のフランジ部と固定基台の突壁部との間には、金型側の面と金型に対し反対側の面とのうち少なくとも一方の側の面を楔傾斜面としかつ自重により下降可能とした楔形梁体が、加圧気体導入管を跨ぐように上方から挿入され、かつ前記フランジ部と突壁部とのうち少なくとも一方には、前記楔形梁体の楔傾斜面に沿ってその楔傾斜面に接する受け用傾斜面が形成されており、これらのフランジ部、固定基台および楔形梁体によって前記付勢手段が構成されていることを特徴とするものである。
【００１９】
このような請求項３の発明の超塑性成形装置においては、加圧気体導入管のフランジ部と固定基台の突壁部との間に上方から挿入された楔形梁体が、その自重により加圧気体導入管に対して金型外方への付勢力を与える。すなわち、楔形梁体には、金型側の面（以下これを前面と記す）と金型に対し反対側の面（以下これを後面と記す）とのうち少なくとも一方の面が楔傾斜面とされており、また加圧気体導入管のフランジ部と突壁部とのうち少なくとも一方には楔形梁体の楔傾斜面に沿ってその楔傾斜面に接する受け用傾斜面が形成されており、楔形梁体の前面側、後面側のいずれに楔傾斜面が形成されている場合も、楔形梁体の自重によって加圧気体導入管に金型外方へ付勢する力を与えることができる。例えば楔形梁体における後面に楔傾斜面が形成されて、それに対応して加圧気体導入管のフランジ部に受け用傾斜面が形成されている場合には、楔形梁体の自重による下方への力が楔傾斜面とそれに接する受け用傾斜面により、フランジ部を金型外方へ押す力、すなわち加圧気体導入管を金型外方へ押す付勢力に変換される。また例えば楔形梁体における前面に楔傾斜面が形成されて、それに対応して固定基台の突壁部に受け用傾斜面が形成されている場合には、楔形梁体の自重による下方への力が、楔傾斜面とそれに接する受け用傾斜面により、固定基台の突壁部を金型側へ押す力に変換されるが、突壁部は固定されているため、その反力が楔形梁体に金型外方へ押す力として加わり、その楔形梁体を介して加圧気体導入管のフランジ部が金型外方へ押され、ひいては加圧気体導入管自体が金型外方へ付勢されることになる。もちろん後述するように、楔形梁体の前後両面に楔傾斜面を形成しておいても良く、その場合には上述の両方の力が同時に作用し、一層確実かつ安定して楔形梁体を後方へ付勢することができる。
【００２０】
ここで、上下の金型と、下金型から突出する固定基台は、超塑性成形のための高温の超塑性温度域で熱膨張するが、楔形梁体はその自重によって前述のように加圧気体導入管に対し常に後方へ押す力すなわち金型から離隔させる方向の力を付与しているから、熱膨張により固定基台の突壁部の位置が変位しても、楔形梁体の自重により前述の方向への付勢力が保たれる。したがって熱膨張による変位の影響を受けずに、加圧気体導入管を常時金型外方へ付勢し、その加圧気体導入管の先端部の外径拡大部を、間に超塑性金属板を介在させた状態で金型周縁部の凹部の端縁に押し付けることができるのである。
【００２１】
ここで、請求項３に記載の超塑性成形装置においては、次のような構成とすることが望ましい。すなわち、前記楔形梁体の金型側の面と金型に対し反対側の面との両面に楔傾斜面を形成し、かつ加圧気体導入管のフランジ部に、楔形梁体における金型に対し反対側の楔傾斜面に沿う受け用傾斜面を形成するとともに固定基台の突壁部にも楔形梁体の金型側の楔傾斜面に沿う受け用傾斜面を形成する。このような構成とすれば、楔形梁体の自重による力が、楔形梁体の後面側の楔傾斜面とそれに接する加圧気体導入管のフランジ部の受け用傾斜面との間、および楔形梁体の前面側の楔傾斜面とそれに接する固定基台の突壁部の受け用傾斜面との間のいずれの間においても、加圧気体導入管を金型外方へ付勢する力に有効に変換されるため、加圧気体導入管を、より確実かつ安定して定位置に保持することができる。
【００２２】
さらに上述のように楔形梁体を用いる場合、その楔形梁体は、上金型の側縁部分に上下方向に移動可能に支持することが望ましい。このようにすれば、楔形梁体は上金型に支持されているから、ブロー成形の開始のための準備作業時において型締めのために上金型を降下させるに伴なって楔形梁体を所要の位置（加圧気体導入管を跨ぐ位置）に容易にセットすることができ、またブロー成形終了後の型開きのために上金型を上昇させるに伴なって楔形梁体を加圧気体導入管から上方へ外すことができる。したがって楔形梁体のセット、取外しの作業が容易となる。
【００２３】
一方請求項４の発明は、上下の金型間に複数枚の超塑性金属板をその周縁部が上下の金型の周縁部に挟まれるように積層して挟持し、上下の金型の端縁側から超塑性金属板間に加圧気体導入管の先端部を挿入し、その加圧気体導入管を介して超塑性金属板間へ加圧気体を導入して超塑性金属板をブロー成形するようにした超塑性成形装置において、前記加圧気体導入管における金型周縁部に挟まれる部分に外径拡大部が形成され、また上下の金型の周縁部には、中間に超塑性金属板を介在させた状態で前記外径拡大部が嵌入される凹窪部が形成されていることを特徴とするものである。
【００２４】
このような請求項４の発明の超塑性成形装置においては、上下の金型の周縁部に形成された凹窪部内に、間に超塑性金属板を挟んで加圧気体導入管の外径拡大部が嵌入されて、その凹窪部によって加圧気体導入管が前後方向（金型内方へ向う方向および外方へ向う方向）に移動することが阻止される。したがって請求項１の超塑性成形装置の場合と同様に、加圧気体導入時にその反力により加圧気体導入管が金型外方へ抜け出る方向へ移動することが防止される。また加圧気体導入管は金型周縁部の位置でその移動が阻止されるため、金型の熱膨張による変位の影響を受けて移動してしまうこともない。
【００２５】
なお以上のところにおいて、前記加圧気体導入管は、水平な支軸を中心として傾動可能となるように下金型の端縁側に取付けることが望ましい。このような構成とすれば、加圧気体導入管が下金型の端縁側に支持されていてしかも傾動可能であるため、ブロー成形の開始のための準備作業時においては下金型上に下側の超塑性金属板を載置した段階で加圧気体導入管を傾動させるだけで容易に所定の位置に加圧気体導入管をセットすることができ、加圧気体導入管の位置決めを簡単に行なうことができる。
【００２６】
【発明の実施の形態】
【００２７】
【実施例】
図１〜図４にはこの発明の一実施例の膨張成形装置の要部、すなわち加圧気体導入部分を示す。
【００２８】
図１〜図４において、上金型１Ａ、下金型１Ｂは超塑性金属板３Ａ，３Ｂを間に挟んでこれをブロー成形するためのキャビティ７を形成したものである。また下金型１Ｂの周縁部の上面には幅広な一条のビード部３１Ｂが一体に形成されており、また上金型１Ａの下面には、下金型１Ｂのビード部３１Ｂに対応する細い２条のビード部３１Ａ，３１Ａ′が一体に形成されている。これらのビード部３１Ａ，３１Ａ′；３１Ｂは超塑性金属板３Ａ，３Ｂの周縁部分を気密にシールして、キャビティ７を密閉するためのものである。
【００２９】
以上の構成は従来の一般的な超塑性ブロー成形用金型と同様であるが、さらにこの発明の実施例の超塑性成形装置では、次のように構成されている。
【００３０】
すなわち、上金型１Ａの周縁部の一部の下面および下金型１Ｂの周縁部の一部の上面には、後に詳細に説明する加圧気体導入管３３を挿入するための凹部３８Ａ，３８Ｂが形成されている。なおこれらの凹部３８Ａ，３８Ｂは、前述のビード部３１Ａ，３１Ａ′；３１Ｂの部分のみに形成したものでも、また金型本体部分まで凹状に切欠いて形成したものであっても良い。加圧気体導入管３３は、内側に加圧気体導入路３４が形成されるとともに、金型１Ａ，１Ｂの内側へ開口するノズル部３７が先端に形成されたものであり、その加圧気体導入管３３の長さ方向の中間部には、外周方向へ突出するフランジ部３５が形成されて、このフランジ部３５により加圧気体導入管３３はフランジ部３５よりも前方（金型寄り）の部分（前方部分）３３Ａと、フランジ部３５よりも後方（外側）の部分（後方部分）３３Ｂとに区分されている。そして加圧気体導入管３３の前方部分３３Ａの先端部分には後方から前方へ向けて、すなわち金型外方から内方へ向けて外径が拡大する外径拡大部３６が形成され、一方後方部分３３Ｂの後端にはジョイント３９を介して可撓性を有する加圧気体供給配管４１が接続されている。前記外径拡大部３６は、要はそれより金型外方の基管部分の径に対し、金型外方側から内方側へ向けて径が拡大する傾斜面３６Ａを有していれば良く、その具体的形状は、球体状、楕円体状あるいは円錐体状など、種々の形状とすることができる。
【００３１】
前記フランジ部３５は、加圧気体導入管３３に対する横断方向（長さ方向に対し直交する面）に沿って延びている長板状をなすように形成されており、かつそのフランジ部３５の前面（金型に近い側の面）は、第１の受け用傾斜面４３Ａとされている。このフランジ部３５の第１の受け用傾斜面４３Ａは、下方に向って金型１Ａ，１Ｂに近接する方向に傾斜する面とされている。
【００３２】
さらに下金型１Ｂには、前記加圧気体導入管３３が挿入される側の端縁から外方へ突出する固定基台４５が設けられている。この固定基台４５は、下金型１Ｂと連続一体に形成しても、あるいは別部材を下金型１Ｂに固定した構成としても良い。固定基台４５には、下金型１Ｂの近くの位置で上方へ隆起する第１の突壁部４５Ａと、水平方向突出端の部分で上方へ隆起する第２の突壁部４５Ｂとが一体に形成されており、第１の突壁部４５Ａの上部には、加圧気体導入管３３の前方部分３３Ａが上方から遊嵌される溝状の凹部４５Ｃが上方へ開口するように形成されており、また第２の突壁部４５Ｂの上部には、加圧気体導入管３３の後方部分３３Ｂにおける後端寄りの部分が上方から遊嵌される溝状の凹部４５Ｄが上方へ開口するように形成されている。そして前記第１の突壁部４５Ａの後面（金型１Ａ，１Ｂに対し反対側の面）は、第２の受け用傾斜面４３Ｂとされている。この第２の受け用傾斜面４３Ｂは、下方に向って金型１Ａ，１Ｂから離隔する方向へ傾斜する面とされている。そしてまた固体基台４５における第１の突壁部４５Ａと第２の突壁部４５Ｂとの間の上面には、後述する楔形梁体５５の下端部が充分な遊びをもって挿入される挿入溝４７が形成されている。
【００３３】
一方上金型１Ａには、加圧気体導入管３３が挿入される側の端縁から外方へ突出する平行一対の支持アーム５３Ａ，５３Ｂが形成されており、これらの支持アーム５３Ａ，５３Ｂの先端部近くには、上下に貫通する案内孔５４Ａ，５４Ｂが形成されている。これらの支持アーム５３Ａ，５３Ｂには、次に述べるように楔形梁体５５が上下方向に移動自在に取付けられている。
【００３４】
すなわち、楔形梁体５５は、全体として、固定基台４５の挿入溝４７と平行に伸びる長い梁状に作られるとともに、その長さ方向に対し直交する断面が楔形をなすように、前面（金型１Ａ，１Ｂに近い側の面）および後面（金型１Ａ，１Ｂに対し反対側の面）がそれぞれ楔傾斜面５７Ａ，５７Ｂとされている。そして楔形梁体５５の前面側の楔傾斜面５７Ａは固定基台４５の第１の突壁部４５Ａの受け用傾斜面４３Ｂと平行な傾斜が与えられており、また後面側の楔傾斜面５７Ｂは加圧気体導入管３３のフランジ部３５の受け用傾斜面４３Ａと平行な傾斜が与えられている。そしてこの楔形梁体５５の中央部下側には、加圧気体導入管３３の前方部分３３Ａを跨ぐ切欠凹部５５Ａが形成され、その切欠凹部５５Ａの両脇側には、前述の支持アーム５３Ａ，５３Ｂが遊びをもって挿入される水平貫通孔５５Ｂ，５５Ｃが形成されている。さらに水平貫通孔５５Ｂ，５５Ｃの部分には、これを上下に突き通るように上面側からネジピン５８Ａ，５８Ｂが挿着されて、このネジピン５８Ａ，５８Ｂが前記支持アーム５３Ａ，５３Ｂの案内孔５４Ａ，５４Ｂ内に遊びをもって挿入されている。したがって楔形梁体５５は、水平方向への若干の移動が許容された状態でネジピン５８Ａ，５８Ｂにより案内されて上下に移動自在となるように支持アーム５３Ａ，５３Ｂに取付けられていることになる。換言すれば、楔形梁体５５は、その自重によって下降し得るように支持アーム５３Ａ，５３Ｂに取付けられており、しかもその下降時には水平方向（特に金型１Ａ，１Ｂに接近・離隔する方向）への若干の移動が許容されることになる。
【００３５】
次に図１〜図４に示される実施例の超塑性成形装置の機能について説明する。
【００３６】
２枚の超塑性金属板３Ａ，３Ｂおよび加圧気体導入管３３を金型１Ａ，１Ｂ間にセットして超塑性ブロー成形を行なうにあたっては、上金型１Ａ，下金型１Ｂ間を開放させた状態（一般には上金型１Ａを上昇させた状態）で、下金型１Ｂ上に下側の超塑性金属板３Ｂを載置する。この状態で加圧気体導入管３３をその外径拡大部３６が下金型１Ｂの周縁部の凹部３８Ｂよりも内側に位置するように、また前方部分３３Ａが第１の突壁部４５Ａの凹部４５Ｃに挿入されかつ後方部分３３Ｂが第２の突壁部４５Ｂの凹部４５Ｄに挿入されるようにセットする。次いで加圧気体導入管３３を挟み込むように上側の超塑性金属板３Ａを下側の超塑性金属板３Ｂ上に載置した後、上金型１Ａを下降させて上金型１Ａ、下金型１Ｂ間を閉じ、型締めを行なう。このとき、加圧気体導入管３３の外径拡大部３６の外側傾斜面３６Ａと、上金型１Ａ、下金型１Ｂの周縁部の凹部３８Ａ，３８Ｂにおける金型内方側の端縁との間に超塑性金属板３Ａ，３Ｂが挟まれることになる。また上金型１Ａから突出する支持アーム５３Ａ，５３Ｂに支持されている楔形梁体５５は、上金型１Ａの下降とともに下降し、その楔形梁体５５の切欠凹部５５Ａが加圧気体導入管３３の前方部分３３Ａを跨いで、切欠凹部５５Ａの両側の下端部が固定基台４５の挿入溝４７に挿入される。そしてこの楔形梁体５５は、前面側の第１の楔傾斜面５７Ａが固定基台４５の第１の突壁部４５Ａの受け用傾斜面４３Ｂに接するとともに、後面側の第２の楔傾斜面５７Ｂが加圧気体導入管フランジ部３５の受け用傾斜面４３Ａに接した状態でその下降が停止する。ここで、楔形梁体５５は、前述のように上下方向に移動自在とされているから、楔形梁体５５の自重が各楔傾斜面５７Ａ，５７Ｂから受け用傾斜面４３Ｂ，４３Ａに加えられ、自重による鉛直方向下向きの力が水平方向への力に変換される。すなわち、後面側の第２の楔傾斜面５７Ｂは、加圧気体導入管フランジ部３５の受け用傾斜面４３Ａを後方へ押し、加圧気体導入管３３に対して金型１Ａ，１Ｂから離隔する方向への力を与える。一方前面側の楔傾斜面５７Ａは、固定基台４５の第１の突壁部４５Ａの受け用傾斜面４３Ｂを前方へ押圧し、その反力として楔形梁体５５に後方（金型１Ａ，１Ｂから離隔する方向）の力が与えられ、その楔形梁体５５を介して加圧気体導入管フランジ部３５を後方へ押すことになる。したがって楔形梁体５５の自重によって加圧気体導入管３３を金型外方へ付勢する力が常時与えられることになる。そしてこの付勢力によって加圧気体導入管３３の外径拡大部３６が金型周縁部の凹部３８Ａ，３８Ｂの端縁に向けて常時押し付けられて、その位置が固定維持されることになる。
【００３７】
以上のようにして各部材を所定の位置にセットし、しかも金型１Ａ，１Ｂを超塑性温度域に加熱した状態で、加圧気体供給配管４１から加圧気体導入管３３を介して不活性ガスなどの加圧気体をノズル部３７から上下の超塑性金属板３Ａ，３Ｂ間に吹き込めば、その気体圧力によって超塑性金属板３Ａ，３Ｂをブロー成形することができる。そして加圧気体を超塑性金属板３Ａ，３Ｂ間に吹き込むにあたっては、その加圧気体の反力によって加圧気体導入管３３に金型１Ａ，１Ｂから外側へ抜け出る方向の力が与えられるが、前述のように加圧気体導入管３３の外径拡大部３６が金型１Ａ，１Ｂの周縁部の凹部３８Ａ，３８Ｂの金型内方端縁より内側に位置して、その位置が固定維持されるため、加圧気体導入管３３は外側に抜け出ることが防止される。
【００３８】
ここで、超塑性温度域の高温雰囲気では熱膨張による変位によって固定基台４５の第１の突壁部４５Ａと加圧気体導入管フランジ部３５との間の間隔が変化することがあるが、その間に介挿されている楔形梁体５５は自重によって常時加圧気体導入管３３に対し金型１Ａ，１Ｂから離隔させる方向の力を与え続けているから、熱膨張による変位の影響を受けることなく、加圧気体導入管３３を常時金型外方へ付勢して、外径拡大部３６を金型周縁部の凹部３８Ａ，３８Ｂの金型内側端縁に押し付け続けることになる。
【００３９】
そして、前述のように加圧気体導入管３３が移動することが防止される結果、加圧気体導入管３３とその上下の超塑性金属板３Ａ，３Ｂとの間に隙間が生じることも防止され、またそれに伴ないその隙間を介して加圧気体が外部へ漏洩してしまう事態が生じることを有効に防止できる。
【００４０】
なお図１〜図４に示される実施例においては、楔形梁体５５の前後両面に楔傾斜面を形成しているが、既に述べたところから明らかなように、前後両面のうちいずれか一方のみに楔傾斜面を形成しても、加圧気体導入管３３に金型１Ａ，１Ｂから離隔する方向の付勢力を与えることができる。但しこの場合は、楔形梁体５５の前後両面のうち、楔傾斜面としない側の面は垂直面とし、これに対応する加圧気体導入管フランジ部３５の前面もしくは固定基台４５の第１の突壁部４５Ａの後面も垂直面とする。もちろん実施例に示しているように楔形梁体５５の前後両面を楔傾斜面とした場合の方が、一方の面のみを楔傾斜面とした場合よりも確実かつ安定して加圧気体導入管３３を金型外方へ常時付勢することができる。
【００４１】
また図１〜図４に示される実施例では、上金型１Ａから突出する支持アーム５３Ａ，５３Ｂによって楔形梁体５５を支持しており、このような構成では上金型１Ａを下降させて型を閉じる際に楔形梁体５５も同時に下降して所定位置にセットされることになるから、セット操作が簡単かつ容易となるが、場合によっては楔形梁体５５を上金型１Ａとは別の吊下げ部材、例えばワイヤなどによって上方から下降自在に吊下げても良いことは勿論である。
【００４２】
なお以上のところにおいて、図５に示すように加圧気体導入管３３の外径拡大部３６の外径Ｒ₁は、通常は金型１Ａ，１Ｂの周縁部の凹部３８Ａ，３８Ｂの内径Ｒ₂より大きいことが望ましいが、超塑性金属板３Ａ，３Ｂの厚みｔを考慮すれば、外径拡大部３６の外径Ｒ₁は、要は次式
Ｒ₁＞Ｒ₂−２ｔ
を満たせば良い。
【００４３】
図６には、図１〜図４に示される実施例の一部を変形させた別の実施例を示す。
【００４４】
図６において、固定基台４５の後端の第２の突壁部４５Ｂの溝状の凹部４５Ｄ内には、これを突き通って横断する水平な回動支軸５９が設けられている。一方、加圧気体導入管３３の後方部分３３Ｂには、その下方へ突出する回動支持基板６１が固定されており、この回動支持基板６１には、長径方向が加圧気体導入管３３の長さ方向と平行な方向に沿う長孔６３が貫通形成されており、この長孔６３に前述の支軸５９が相対的に回動可能に挿通されている。
【００４５】
このような構造では、加圧気体導入管３３が、支軸５９を中心として傾動可能に固定基台４５の第２の突壁部４５Ｂに取付けられていることになるため、超塑性ブロー成形のための準備作業時においても、一挙動で加圧気体導入管３３を所要の位置に簡単にセットすることができる。すなわち、上金型１Ａを上昇させて型を開き、しかも図６の鎖線で示すように加圧気体導入管３３をそのノズル部３７が上方を向くように傾けた状態で、下側の超塑性金属板３Ｂを下金型１Ｂ上に載置し、次いで加圧気体導入管３３を反時計方向へ回動させてノズル部３７を超塑性金属板３Ｂ上に載置し、その後は図１〜図４の実施例の場合と同様に上側の超塑性金属板３Ａを載置した後、上金型１Ａを下降させて型締めを行なえば良い。なお加圧気体導入管３３は長孔６３の部分で支軸５９により支持されているため、前後方向（金型１Ａ，１Ｂに接近・離隔する方向）への移動が許容され、したがってブロー成形時に金型１Ａ，１Ｂおよび固定基台４５が熱膨張により変位した際にも、加圧気体導入管３３には前述の楔形梁体５５の自重により後方へ付勢する力が与えられる。すなわち熱膨張により固定基台４５の第２の突壁部４５Ｂの位置が変位しても、それによって加圧気体導入管３３が移動してしまうことはない。
【００４６】
なお以上の説明では、加圧気体導入管３３を金型外方へ付勢するための付勢手段として楔状梁体５５の自重を利用することとしたが、付勢手段としてはこれに限らず、例えばスプリング等を用いることもできる。
【００４７】
図７には、この発明のさらに別の実施例、すなわち請求項４の発明に対応する実施例の超塑性成形装置の要部を示す。
【００４８】
図７において、加圧気体導入管３３の外径拡大部３６は、ノズル部３７の先端よりも若干金型外方寄りの位置、すなわち上下の金型１Ａ，１Ｂの周縁部に挟まれる部分（ビード部３１Ａ，３１Ｂに挟まれる部分）に形成されている。一方上金型１Ａの周縁部下面（ビード部３１Ａの下面）には凹窪部７１Ａが、また下金型１Ｂの周縁部上面（ビード部３１Ｂの上面）には凹窪部７１Ｂが形成されており、これらの凹窪部７１Ａ，７１Ｂの間に、中間に超塑性金属板３Ａ，３Ｂを介在させた状態で加圧気体導入管３３の外径拡大部３６を嵌入させる構造とされている。また固定基台４５が下金型１Ｂから外方へ突出するように設けられており、この固定基台４５には、図１〜図４の例における第２の突壁部４５Ｂと同様に突壁部４５Ｂが形成されており、この突壁部４５Ｂに図６の例と同様に加圧気体導入管３３が支軸５９および長孔６３によって傾動可能でかつ前後方向へ移動可能となるように支持されている。
【００４９】
このような図７の実施例においては、加圧気体導入管３３の外径拡大部３６が金型周縁部の凹窪部７１Ａ，７１Ｂ間に超塑性金属板３Ａ，３Ｂを介して保持されるため、加圧気体導入管３３が前後方向へ移動することが阻止される。したがって図１〜図４の実施例と同様に加圧気体導入管３３が金型外方へ抜け出ることが防止され、また加圧気体導入管３３の移動によって加圧気体導入管３３とこれを挟む超塑性金属板３Ａ，３Ｂとの間に隙間が生じることも防止される。
【００５０】
【発明の効果】
請求項１の発明の超塑性成形装置によれば、ブロー成形のための加圧気体導入時にその反力によって加圧気体導入管に金型外方への力が与えられても、加圧気体導入管の先端に形成された外径拡大部が超塑性金属板を介して金型内縁部の凹部の端縁に押し付けられるだけでその加圧気体導入管の移動が阻止されるから加圧気体導入管が外側へ抜け出てしまうことを確実に防止できる。そしてまた加圧気体導入管の移動により加圧気体導入管とそれを上下に挟む超塑性金属板との間に隙間が生じることを防止でき、そのためその隙間から外部へ加圧気体が漏洩して加圧不足により成形が困難となってしまうような事態が生じることを有効に防止できる。
【００５１】
また請求項２の発明の超塑性成形装置によれば、加圧気体導入管に常時金型外方への付勢力が与えられて、加圧気体導入管の外径拡大部が常時金型周縁部の凹部の金型内方端縁側に強制的に押し付けられているため、加圧気体導入管の位置を確実に固定・維持することができ、そのため前述の効果をより一層安定かつ確実に発揮させることができる。
【００５２】
さらに請求項３の発明の超塑性成形装置によれば、楔状梁体の自重によって前述の付勢力が与えられ、この付勢力に対しては熱膨張による変位が影響を及ぼさないため、熱膨張による変位の影響によって加圧気体導入管が移動してしまうことを確実に防止することができる。
【００５３】
また請求項４の発明の超塑性成形装置においては、加圧気体導入管の外径拡大部が上下の金型の周縁部の凹窪部間に嵌入してその位置が固定・維持され、したがって前記請求項１と同様な効果を得ることができる。
【図面の簡単な説明】
【図１】この発明の一実施例の超塑性成形装置の要部を示す縦断側面図である。
【図２】図１のＩＩ−ＩＩ線における縦断面図である。
【図３】図２のＩＩＩ−ＩＩＩ線における縦断面図である。
【図４】図１に示される実施例の装置の分解斜視図である。
【図５】図１に示される実施例における加圧気体導入管の先端部付近の状況を拡大して示す略解図である。
【図６】この発明の別の実施例の超塑性成形装置の要部を示す縦断側面図である。
【図７】この発明のさらに別の実施例の超塑性成形装置の要部を示す縦断側面図である。
【図８】従来の超塑性膨張成形装置における加圧気体導入部分の構造の一例を示す縦断面図である。
【図９】従来の超塑性膨張成形装置における加圧気体導入部分の構造の他の例を示す縦断面図である。
【符号の説明】
１Ａ上金型
１Ｂ下金型
３Ａ，３Ｂ超塑性金属板
７キャビティ
３３加圧気体導入管
３５フランジ部
３６外径拡大部
３８Ａ，３８Ｂ凹部
４３Ａ，４３Ｂ受け用傾斜面
４５固定基台
４５Ａ第１の突壁部
５５楔形梁体
５５Ａ切欠凹部
５７Ａ，５７Ｂ楔傾斜面
５９支軸
７１Ａ，７１Ｂ凹窪部[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an apparatus for superplastic forming various metal plates (superplastic metal plates) exhibiting superplasticity in a specific high temperature region, and more particularly, superplastic metal plates obtained by laminating a plurality of superplastic metal plates. The present invention relates to an apparatus for blow molding each superplastic metal plate by applying a gas pressure therebetween.
[0002]
[Prior art]
In recent years, various superplastic metal materials have been developed that exhibit significantly large elongation in a predetermined high temperature range (superplastic temperature range) of, for example, about 250 to 350 ° C or about 350 to 550 ° C. It is being applied to large-sized molded products such as aircraft parts, automobile parts, precision equipment and the like. As such a superplastic metal material, for example, an Al-Zn alloy, an Al-Zn-Mg-Cu alloy, an Al-Mg-Mn alloy, or the like is known as an aluminum alloy system, in addition, a titanium alloy material, Stainless steel materials are also known.
[0003]
By the way, as a typical method for actually forming in a superplastic temperature range using a superplastic metal plate, there is a method of blow-molding using the pressure of a pressurized gas. As a specific method for superplastic forming a superplastic metal plate by such blow molding, a single superplastic metal plate is sandwiched between an upper mold and a lower mold, and the superplastic temperature range is set. In a heated state, a pressurized gas such as an inert gas is introduced into the space (cavity) between the inner surface of one mold and the superplastic metal plate, and the pressure causes the superplastic metal plate to adhere to the other mold. The method of deforming toward the inner surface was common, but recently, two superplastic metal plates are laminated and sandwiched between the upper mold and the lower mold and held in the superplastic temperature range. For example, Japanese Patent Application Laid-Open No. 7-1050 proposes a method in which a pressurized gas is introduced between the two superplastic metal plates to simultaneously blow-mold the two superplastic metal plates. In such a method, it is possible not only to improve the productivity of the molding process by simultaneously blow-molding two superplastic metal plates, but also to form a hollow portion between the two laminated metal plates. There is an advantage that a part can be manufactured by a simple process.
[0004]
By the way, in the method of simultaneously blow-molding two superplastic metal plates laminated as described above, a pressurized gas must be introduced between the laminated superplastic metal plates. As concrete means, the above-mentioned proposal of Japanese Patent Laid-Open No. 7-1050 discloses two types of structures, the structure shown in FIG. 8 and the structure shown in FIG. Next, the structure for introducing these pressurized gases will be described.
[0005]
In FIG. 8, two superplastic metal plates 3A and 3B are sandwiched between an upper mold 1A and a lower mold 1B. An insertion groove 8 leading to the cavity 7 defined by the upper mold 1A and the lower mold 1B is formed at predetermined positions on the lower surface of the peripheral part of the upper mold 1A and the upper surface of the peripheral part of the lower mold 1B. In the insertion groove 8, a pressurized gas introduction tube (plug) 9 is inserted between the two superplastic metal plates 3A and 3B from the outside. A flange 11 projecting in the outer peripheral direction is formed on the rear part of the pressurized gas introduction pipe 9 (the part outside the upper mold 1A and the lower mold 1B), and on the outer surface side of the lower mold 1B. A bracket 13 protrudes from the bracket 13, and a step 13 A that engages with the edge of the flange 11 of the pressurized gas introduction pipe 9 is formed on the bracket 13.
[0006]
In such a structure shown in FIG. 8, a pressurized gas is blown between the superplastic metal plates 3A and 3B through the pressurized gas introduction tube 9, and the superplastic metal plates 3A and 3B are caused to flow in FIG. In this case, the reaction force at the time of introducing the pressurized gas is applied to the pressurized gas introducing tube 9, and the pressurized gas introducing tube 9 is the upper mold 1A and the lower mold 1B. There is a risk of getting out of it and jumping out. Therefore, in the apparatus shown in FIG. 8, the flange portion 11 of the pressurized gas introduction tube 9 is received by the step portion 13A of the bracket 13, and the pressurized gas introduction tube 9 is prevented from being pulled out by the reaction force described above.
[0007]
On the other hand, in the structure shown in FIG. 9, through holes 17 are formed in the peripheral plate surface of the superplastic metal plate 3A located on the upper surface side, for example, of the two superplastic metal plates 3A and 3B. A pressurized gas introduction path 19 is formed through the upper mold 1A at a position corresponding to the through hole 17, and a predetermined position between the peripheral edges of the upper mold 1A and the lower mold 1B (the through Recesses 15A and 15B are formed in the hole 17 and the position corresponding to the pressurized gas introduction path 19). Then, when the two superplastic metal plates 3A and 3B are stacked and sandwiched between the upper mold 1A and the lower mold 1B, the piece-like member 21 is sandwiched at a position corresponding to the recessed portions 15A and 15B. . This piece-like member 21 is formed with a communication path 23 that opens from a portion corresponding to the through hole 17 of the upper superplastic metal plate 3A toward the cavity 7 inside the upper mold 1A and the lower mold 1B. is there.
[0008]
In such a structure shown in FIG. 9, the pressurized gas introduction path 19 formed in the upper mold 1A, the through-hole 17 formed in the upper superplastic metal plate 3A, and the continuous member 21 are connected. Pressurized gas is blown between the two superplastic metal plates 3A and 3B through the passage 23, and the two superplastic metal plates 3A and 3B can be blow-molded in the cavity 7 by the pressure. Here, although the reaction force at the time of introducing the pressurized gas is applied to the top member 21, in order to sandwich the superplastic metal plates 3A and 3B between the upper mold 1A and the lower mold 1B, the upper mold 1A, The superplastic metal plates 3A and 3B are deformed in a curved shape along the piece-like member 21 and the recessed portions 15A and 15B at the portion of the piece-like member 21 due to the clamping force between the lower mold 1B. Depending on the reaction force, the top member 21 does not slip out.
[0009]
[Problems to be solved by the invention]
The conventional gas introduction structure in the superplastic blow molding apparatus has the following problems.
[0010]
First, in the structure shown in FIG. 8, the stepped portion 13 A of the bracket 13 receives the flange portion 11 of the pressurized gas introduction tube 9, so that the pressurized gas introduction tube 9 may come out due to the reaction force when the pressurized gas is introduced. In this structure, it is possible to prevent the pressurized gas introduction tube 9 from popping out to the outside due to the reaction force when the pressurized gas is introduced, but the actual superplastic blow At the time of molding, the engagement of the flange portion of the pressurized gas introduction tube 9 and the stepped portion 13A of the bracket 13 may be disengaged and the pressurized gas introduction tube 9 may come out of the mold, and the pressurized gas introduction tube Even if 9 does not jump out of the mold, it moves in the direction of exiting and a gap is generated between the pressurized gas introduction tube 9 and the upper and lower superplastic metal plates 3A and 3B sandwiching this, and a cavity is formed at that portion. 7 leaks and the superplastic metal plate 3A, There is a possibility that situation no longer obtained to reliably molded produce B.
[0011]
That is, as already described, the superplastic forming must be performed in a high temperature superplastic temperature range of about 250 to 350 ° C. or about 350 to 550 ° C. At such a high temperature, the molds 1A and 1B thermally expand. The bracket 13 integrated with the lower mold 1B also thermally expands, but the pressurized gas introduction tube 9 hardly thermally expands because the pressurized gas at room temperature normally flows inside. A gap is generated between the flange portion 11 of the pressurized gas introduction tube 9 and the stepped portion 13A of the bracket 13, and the pressurized gas introduction tube 9 moves in the direction of exiting to the outside by the reaction force of the introduced gas into the cavity 7. It will be. If the pressurized gas introduction tube 9 moves even a little in this way, a gap is generated between the pressurized gas introduction tube 9 and the superplastic metal plates 3A and 3B sandwiching the pressurized gas introduction tube 9 up and down. The pressurized gas introduced into the cavity 7 will leak. At this time, the pressurized gas leaking to the outside through the gap between the pressurized gas introduction tube 9 and the upper and lower superplastic metal plates 3A, 3B has just been blown from the nozzle at the tip of the pressurized gas introduction tube 9. It is often a low-temperature one that has not risen in temperature, and the superplastic metal plates 3A and 3B are cooled and contracted in the gap portion by the low-temperature leaked gas, and as a result, the gap is further expanded to increase the pressurized gas. The introduction tube 9 is easily pulled out, and in the worst case, the pressurized gas introduction tube 9 may come off. Further, even if the pressurized gas introduction tube 9 does not come off, due to the expansion of the gap between the pressurized gas introduction tube 9 and the superplastic metal plates 3A and 3B as described above, a large amount of gas leaks through the gap. Therefore, effective pressurizing force cannot be applied to the cavity 7 and molding may be difficult.
[0012]
On the other hand, in the conventional structure shown in FIG. 9, the reaction force at the time of introducing the pressurized gas is applied to the piece-like member 21, and this piece-like member 21 is formed by the recessed portions 15A, 15B of the upper and lower molds 1A, 1B. The coma-shaped member 21 is pulled out to the outside, or is added to the outside through the gap between the coma-shaped member 21 and the superplastic metal plates 3A, 3B. There is little risk of leaking of pressurized gas. However, in the case of the structure shown in FIG. 9, the through-hole 17 must be formed in the superplastic metal plate 3A in advance, and the through-hole 17 is the opening position of the pressurized gas introduction path 19 of the upper mold 1A. Therefore, it is necessary to position so as to accurately correspond to each other, and therefore it takes a lot of time and labor to form the through-hole 17. Furthermore, prior to the start of the blow molding operation, the top member 21 must be disposed in a correct posture at a position that accurately corresponds to the recessed portions 15A and 15B of the upper mold 1A and the lower mold 1B. Thus, it is extremely difficult to actually place the piece-like member 21 in the correct position at the correct position in actual work. That is, as a preparatory work for blow molding, first, one superplastic metal plate 3B is placed on the lower mold 1B, and then the piece-like member 21 is placed at a predetermined position on one superplastic metal plate 3B ( In a state in which the other superplastic metal plate 3A is placed and the mold is clamped, thereby sandwiching the piece-like member 21 in the middle. The two superplastic metal plates 3A and 3B are sandwiched between the upper and lower molds 1A and 1B. At the stage of placing the top member 21 on the lower superplastic metal plate 3B, Since the concave portion 15B of the mold 1B is concealed by the superplastic metal plate 3B, the position of the concave portion 15B cannot be confirmed by visual observation, and therefore the accurate positioning of the top member 21 is extremely difficult. there were. Moreover, it is generally necessary to perform the preparatory work as described above in a high temperature atmosphere in which the mold has been preheated in a high temperature range for blow molding. It must be said that it is extremely difficult to dispose in a proper position, which requires time and labor, and is a major cause of hindering productivity. Therefore, it must be said that the method using the above-mentioned piece-shaped member is difficult to apply to actual operation.
[0013]
The present invention has been made against the background described above, and an object thereof is to provide a superplastic forming apparatus for blow molding having a pressurized gas introduction structure capable of solving the above-mentioned problems. That is, the superplastic forming apparatus of the present invention has a structure in which the nozzle part of the pressurized gas introduction tube is sandwiched between the laminated superplastic metal plates from the edge side according to the conventional pressurized gas introduction structure shown in FIG. However, the pressurized gas introduction tube is surely prevented from moving in the direction of exiting, which causes the pressurized gas introduction tube to come out of the mold, or the superplasticity that sandwiches the pressurized gas introduction tube. The object is to reliably prevent the occurrence of a situation in which a gap is generated between the metal plate and the pressurized gas leaks, which makes it difficult to form.
[0014]
[Means for Solving the Problems]
In order to solve the above-described problems, the present invention basically has a structure in which a plurality of superplastic metal plates are laminated between upper and lower molds so that the peripheral part is sandwiched between the peripheral parts of the upper and lower molds. The tip of the pressurized gas introduction tube is inserted between the superplastic metal plates from the edge sides of the upper and lower molds, and the pressurized gas is introduced between the superplastic metal plates through the pressurized gas introduction tube. In a superplastic forming apparatus that is introduced and blow-molds a superplastic metal plate, the diameter expands along the direction from the outside of the mold to the inside of the mold at the tip of the pressurized gas introduction tube. An outer diameter enlarged portion is formed, and a superplastic metal plate is interposed in the peripheral portion of the upper and lower molds with a base tube portion closer to the outer side of the mold than the outer diameter enlarged portion in the pressurized gas introduction pipe A recessed portion is formed so as to be sandwiched in a state where the pressurized gas introduction pipe is moved outward from the mold by the edge on the inner side of the mold in the recessed portion. It is characterized in that it has configured to prevent the.
[0015]
In such a superplastic forming apparatus, the pressurized gas introduction pipe is prevented from moving outward from the mold by the inner edge of the recess formed in the peripheral edge of the upper and lower molds. Is done. That is, even if a force is applied to the outside of the mold against the pressurized gas introduction tube, the outer surface of the outer side of the mold at the outer diameter enlarged portion of the distal end portion of the pressurized gas introduction tube is a superplastic metal plate. And indirectly contacts the edge of the concave portion, and the movement of the pressurized gas introduction tube is prevented by the edge of the concave portion. Therefore, even if the reaction force when the pressurized gas is blown between the superplastic metal plates through the pressurized gas introduction pipe is applied to the pressurized gas introduction pipe, the pressurized gas introduction pipe may come out from between the upper and lower molds. In addition, it is possible to prevent a gap from being generated between the pressurized gas introduction tube and the upper and lower superplastic metal plates sandwiching the pressurized gas introduction tube due to the movement of the pressurized gas introduction tube, and thus the pressurized gas. Can be prevented from leaking through the gap. Here, since the movement of the pressurized gas introduction pipe is blocked between the peripheral portions of the upper and lower molds, the movement of the pressurized gas introduction pipe is not affected by the displacement due to the thermal expansion of the upper and lower molds. Can be reliably prevented.
[0016]
The invention according to claim 2 is the superplastic forming apparatus according to claim 1, further comprising an urging means for urging the pressurized gas introduction tube from the inside of the mold to the outside. It is characterized by.
[0017]
Thus, in the superplastic forming apparatus according to the second aspect of the present invention, since the pressurized gas introduction tube is urged from the inside of the mold toward the outside of the die, the outside of the tip portion of the pressurized gas introduction tube The outer surface of the outer side of the mold of the enlarged diameter portion is always forcedly pressed against the edge of the concave portion of the peripheral edge of the mold (however, a superplastic metal plate is interposed in the middle). Since the position is always fixed and maintained at a fixed position, the movement of the pressurized gas introduction pipe to the outside of the mold can be more reliably prevented.
[0018]
Further, the invention according to claim 3 is the superplastic forming apparatus according to claim 1, wherein a flange portion is formed in a portion outside the mold in the pressurized gas introduction pipe, and the pressurized gas introduction is introduced into a lower mold. A fixed base for receiving the tube is formed so as to protrude from the lower mold, and the fixed base is a recess in which a portion closer to the mold than the flange portion in the pressurized gas introduction pipe is loosely fitted from above. A protruding wall portion is formed, and between the flange portion of the pressurized gas introduction pipe and the protruding wall portion of the fixed base, a surface on the mold side and a surface on the opposite side to the mold A wedge-shaped beam body having a wedge inclined surface on at least one side and capable of being lowered by its own weight is inserted from above so as to straddle the pressurized gas introduction pipe, and at least one of the flange portion and the protruding wall portion Is in contact with the wedge inclined surface along the wedge inclined surface of the wedge-shaped beam body. Are inclined surfaces for receiving formation, these flanges is by the fixed base and the wedge beam body which is characterized in that it is configured for the biasing means.
[0019]
In such a superplastic forming apparatus according to the third aspect of the present invention, the wedge-shaped beam inserted from above between the flange portion of the pressurized gas introduction tube and the protruding wall portion of the fixed base is added by its own weight. A biasing force to the outside of the mold is applied to the pressurized gas introduction pipe. That is, the wedge-shaped beam body has at least one of a die side surface (hereinafter referred to as a front surface) and a surface opposite to the mold (hereinafter referred to as a rear surface) as a wedge inclined surface. Further, at least one of the flange portion and the projecting wall portion of the pressurized gas introduction pipe is formed with a receiving inclined surface in contact with the wedge inclined surface along the wedge inclined surface of the wedge-shaped beam body, Regardless of whether the wedge inclined surface is formed on the front surface side or the rear surface side of the wedge-shaped beam body, a force for urging the pressurized gas introduction pipe to the outside of the mold can be given by the weight of the wedge-shaped beam body. For example, when a wedge inclined surface is formed on the rear surface of the wedge-shaped beam body, and a corresponding inclined surface is formed on the flange portion of the pressurized gas introduction pipe, the downward movement is caused by the weight of the wedge-shaped beam body. The force is converted by the wedge inclined surface and the receiving inclined surface in contact with the wedge inclined surface into a force that pushes the flange portion outward, that is, a biasing force that pushes the pressurized gas introduction tube outward. Further, for example, when a wedge inclined surface is formed on the front surface of the wedge-shaped beam body and a receiving inclined surface is formed on the protruding wall portion of the fixed base correspondingly, the downward movement due to the weight of the wedge-shaped beam body is lowered. The force is converted into a force that pushes the protruding wall part of the fixed base toward the mold side by the inclined surface of the wedge and the receiving inclined surface that is in contact with it, but the reaction force is wedge-shaped because the protruding wall part is fixed. Applied to the beam body as a force to push the mold outward, the flange part of the pressurized gas introduction pipe is pushed to the outside of the mold through the wedge-shaped beam body, and the pressurized gas introduction pipe itself moves to the outside of the mold. Will be energized. Of course, as will be described later, wedge inclined surfaces may be formed on both front and rear surfaces of the wedge-shaped beam body. In this case, both of the above-mentioned forces act simultaneously, and the wedge-shaped beam body is moved more reliably and stably. Can be energized.
[0020]
Here, the upper and lower molds and the fixed base protruding from the lower mold thermally expand in a high superplastic temperature range for superplastic forming, but the wedge-shaped beam body is added as described above by its own weight. Since a force that always pushes backward, that is, a force away from the mold, is applied to the pressurized gas introduction pipe, even if the position of the protruding base wall of the fixed base is displaced due to thermal expansion, the weight of the wedge-shaped beam body Thus, the urging force in the aforementioned direction is maintained. Therefore, without being affected by the displacement due to thermal expansion, the pressurized gas introduction tube is always urged outward from the mold, and the outer diameter enlarged portion of the tip portion of the pressurized gas introduction tube is interposed between the superplastic metal plate. It is possible to press against the edge of the recess at the peripheral edge of the mold with the intervening.
[0021]
Here, in the superplastic forming apparatus according to the third aspect, it is desirable to adopt the following configuration. That is, a wedge inclined surface is formed on both the mold-side surface of the wedge-shaped beam body and a surface on the opposite side to the mold, and the flange portion of the pressurized gas introduction tube is formed on the mold in the wedge-shaped beam body. On the other hand, a receiving inclined surface along the opposite wedge inclined surface is formed, and a receiving inclined surface along the wedge inclined surface on the mold side of the wedge-shaped beam body is also formed on the protruding wall portion of the fixed base. With such a configuration, the force due to the weight of the wedge-shaped beam body is caused between the wedge inclined surface on the rear surface side of the wedge-shaped beam body and the receiving inclined surface of the flange portion of the pressurized gas introduction pipe in contact therewith, and the wedge-shaped beam. Effective for urging the pressurized gas introduction pipe outward from the die between the inclined surface of the wedge on the front side of the body and the receiving inclined surface of the protruding wall of the fixed base in contact with it Therefore, the pressurized gas introduction pipe can be held in place more reliably and stably.
[0022]
Further, when the wedge-shaped beam body is used as described above, the wedge-shaped beam body is desirably supported on the side edge portion of the upper mold so as to be movable in the vertical direction. In this way, since the wedge-shaped beam is supported by the upper mold, the wedge-shaped beam is lowered as the upper mold is lowered for mold clamping during the preparatory work for starting the blow molding. It can be easily set to the required position (position across the pressurized gas introduction pipe), and the wedge-shaped beam body is pressurized gas as the upper mold is raised for mold opening after completion of blow molding. It can be removed upward from the inlet tube. Therefore, it becomes easy to set and remove the wedge-shaped beam body.
[0023]
On the other hand, in the invention of claim 4, a plurality of superplastic metal plates are laminated and sandwiched between upper and lower molds so that the peripheral edge is sandwiched between the peripheral edges of the upper and lower metal molds. Insert the tip of the pressurized gas introduction tube between the superplastic metal plates from the edge side, and blow the superplastic metal plate by introducing the pressurized gas between the superplastic metal plates via the pressurized gas introduction tube. In the superplastic forming apparatus, an outer diameter enlarged portion is formed at a portion sandwiched between the mold peripheral portions of the pressurized gas introduction tube, and a superplastic metal plate is interposed between the peripheral portions of the upper and lower molds. A concave portion into which the outer diameter enlarged portion is inserted is formed in a state where a gap is interposed.
[0024]
In such a superplastic forming apparatus according to the fourth aspect of the present invention, the outer diameter of the pressurized gas introduction tube is increased by sandwiching the superplastic metal plate between the recessed portions formed in the peripheral portions of the upper and lower molds. The recessed portion is inserted to prevent the pressurized gas introduction tube from moving in the front-rear direction (the direction toward the inside of the mold and the direction toward the outside). Therefore, as in the case of the superplastic forming apparatus according to the first aspect, the pressurized gas introduction tube is prevented from moving out of the mold due to the reaction force when the pressurized gas is introduced. In addition, since the movement of the pressurized gas introduction pipe is prevented at the position of the peripheral edge of the mold, the pressurized gas introduction pipe does not move under the influence of the displacement due to the thermal expansion of the mold.
[0025]
In addition, in the above place, it is desirable to attach the said pressurized gas introduction pipe | tube to the edge side of a lower mold | type so that it can tilt about a horizontal spindle. With such a configuration, the pressurized gas introduction tube is supported on the edge side of the lower mold and can be tilted, so that the lower gas mold is placed on the lower mold during the preparatory work for starting the blow molding. When the superplastic metal plate on the side is placed, the pressurized gas introduction tube can be easily set at a predetermined position simply by tilting the pressurized gas introduction tube. Can be done.
[0026]
DETAILED DESCRIPTION OF THE INVENTION
[0027]
【Example】
1 to 4 show an essential part of an expansion molding apparatus according to an embodiment of the present invention, that is, a pressurized gas introduction part.
[0028]
1 to 4, an upper mold 1A and a lower mold 1B are formed by forming a cavity 7 for blow-molding superplastic metal plates 3A and 3B therebetween. Further, a wide single bead portion 31B is integrally formed on the upper surface of the peripheral portion of the lower die 1B, and a thin 2 corresponding to the bead portion 31B of the lower die 1B is formed on the lower surface of the upper die 1A. The bead portions 31A and 31A 'of the strip are integrally formed. These bead portions 31A, 31A '; 31B are for hermetically sealing the peripheral portions of the superplastic metal plates 3A, 3B to seal the cavity 7.
[0029]
The above configuration is the same as that of a conventional general superplastic blow molding die, but the superplastic molding apparatus according to the embodiment of the present invention is configured as follows.
[0030]
That is, recesses 38A and 38B for inserting pressurized gas introduction pipes 33 to be described later in detail on a part of the lower surface of the peripheral part of the upper mold 1A and a part of the upper surface of the peripheral part of the lower mold 1B. Is formed. These concave portions 38A and 38B may be formed only in the above-described bead portions 31A, 31A ′; 31B, or may be formed by cutting out into the mold main body. The pressurized gas introduction pipe 33 is formed with a pressurized gas introduction path 34 on the inside and a nozzle portion 37 that opens to the inside of the molds 1A and 1B. A flange portion 35 that protrudes in the outer peripheral direction is formed at an intermediate portion in the length direction of the tube 33, and the pressurized gas introduction tube 33 is forward (closer to the mold) than the flange portion 35 by the flange portion 35. It is divided into a (front portion) 33A and a rear (outside) portion (rear portion) 33B from the flange portion 35. An outer diameter enlarged portion 36 whose outer diameter increases from the rear to the front, that is, from the outside of the mold to the inside, is formed at the tip of the front portion 33A of the pressurized gas introduction tube 33, while the rear A flexible pressurized gas supply pipe 41 having flexibility is connected to the rear end of the portion 33B through a joint 39. If the outer diameter expanding portion 36 has an inclined surface 36A whose diameter increases from the outer side of the mold toward the inner side with respect to the diameter of the base tube portion on the outer side of the mold. The specific shape may be various shapes such as a sphere, an ellipsoid, or a cone.
[0031]
The flange portion 35 is formed to have a long plate shape extending along a transverse direction (a surface perpendicular to the length direction) with respect to the pressurized gas introduction pipe 33, and the front surface of the flange portion 35. The surface close to the mold is a first receiving inclined surface 43A. The first receiving inclined surface 43A of the flange portion 35 is a surface inclined downward in a direction approaching the molds 1A and 1B.
[0032]
Further, the lower mold 1B is provided with a fixed base 45 that protrudes outward from an edge on the side where the pressurized gas introduction pipe 33 is inserted. The fixed base 45 may be formed integrally with the lower mold 1B, or may be configured such that another member is fixed to the lower mold 1B. The fixed base 45 is integrally formed with a first protruding wall portion 45A that protrudes upward at a position near the lower mold 1B, and a second protruding wall portion 45B that protrudes upward at a portion protruding in the horizontal direction. A groove-like recess 45C into which the front portion 33A of the pressurized gas introduction pipe 33 is loosely fitted from above is formed on the upper portion of the first projecting wall portion 45A so as to open upward. In addition, a groove-like recess 45D into which a portion near the rear end of the rear portion 33B of the pressurized gas introduction pipe 33 is loosely fitted from above is opened upward at the upper portion of the second projecting wall portion 45B. Is formed. The rear surface of the first projecting wall portion 45A (the surface opposite to the molds 1A and 1B) is a second receiving inclined surface 43B. The second receiving inclined surface 43B is a surface inclined downward in a direction away from the molds 1A and 1B. Further, an insertion groove 47 into which a lower end portion of a wedge-shaped beam body 55 described later is inserted with sufficient play on the upper surface of the solid base 45 between the first projecting wall portion 45A and the second projecting wall portion 45B. Is formed.
[0033]
On the other hand, the upper mold 1A is formed with a pair of parallel support arms 53A and 53B protruding outward from the end edge on the side where the pressurized gas introduction tube 33 is inserted. The support arms 53A and 53B Guide holes 54A and 54B penetrating vertically are formed near the tip. A wedge-shaped beam 55 is attached to these support arms 53A and 53B so as to be movable in the vertical direction as described below.
[0034]
That is, the wedge-shaped beam body 55 as a whole is formed in a long beam shape extending in parallel with the insertion groove 47 of the fixed base 45, and the front surface (gold metal) so that the cross section perpendicular to the length direction forms a wedge shape. The surfaces close to the molds 1A and 1B) and the rear surface (surfaces opposite to the molds 1A and 1B) are wedge inclined surfaces 57A and 57B, respectively. The wedge inclined surface 57A on the front surface side of the wedge-shaped beam body 55 is provided with an inclination parallel to the receiving inclined surface 43B of the first protruding wall portion 45A of the fixed base 45, and the wedge inclined surface 57B on the rear surface side. Is provided with an inclination parallel to the receiving inclined surface 43 A of the flange portion 35 of the pressurized gas introduction pipe 33. A cutout recess 55A is formed below the central portion of the wedge-shaped beam body 55 so as to straddle the front portion 33A of the pressurized gas introduction pipe 33, and the support arms 53A, 53B described above are formed on both sides of the cutout recess 55A. Are formed with horizontal through holes 55B and 55C. Further, screw pins 58A, 58B are inserted into the horizontal through holes 55B, 55C from the upper surface side so as to penetrate the holes vertically, and the screw pins 58A, 58B are inserted into the guide holes 54A, 54A of the support arms 53A, 53B. 54B is inserted with play. Therefore, the wedge-shaped beam body 55 is attached to the support arms 53A and 53B so that it can be moved up and down while being guided by the screw pins 58A and 58B in a state where slight movement in the horizontal direction is allowed. In other words, the wedge-shaped beam body 55 is attached to the support arms 53A and 53B so as to be able to descend by its own weight, and at the time of the descending, in the horizontal direction (particularly in the direction approaching / separating the molds 1A and 1B). Will be allowed to move slightly.
[0035]
Next, the function of the superplastic forming apparatus of the embodiment shown in FIGS.
[0036]
When performing superplastic blow molding by setting the two superplastic metal plates 3A and 3B and the pressurized gas introduction pipe 33 between the molds 1A and 1B, the upper mold 1A and the lower mold 1B are opened. The lower superplastic metal plate 3B is placed on the lower mold 1B in the above state (generally, the upper mold 1A is raised). In this state, the pressurized gas introduction tube 33 is arranged such that the outer diameter enlarged portion 36 is positioned inside the concave portion 38B at the peripheral edge of the lower mold 1B, and the front portion 33A is the concave portion of the first protruding wall portion 45A. The rear portion 33B is set so as to be inserted into the recess 45D of the second projecting wall portion 45B. Next, after placing the upper superplastic metal plate 3A on the lower superplastic metal plate 3B so as to sandwich the pressurized gas introduction tube 33, the upper die 1A is lowered to lower the upper die 1A and the lower die. Close 1B and perform mold clamping. At this time, the outer inclined surface 36A of the outer diameter enlarged portion 36 of the pressurized gas introduction pipe 33 and the inner edges of the recesses 38A and 38B at the peripheral edge portions of the upper mold 1A and the lower mold 1B. Superplastic metal plates 3A and 3B are sandwiched between them. Further, the wedge-shaped beam body 55 supported by the support arms 53A and 53B protruding from the upper mold 1A descends as the upper mold 1A descends, and the notch recess 55A of the wedge-shaped beam body 55 becomes the pressurized gas introduction pipe 33. The lower end portions on both sides of the notch recess 55 A are inserted into the insertion grooves 47 of the fixed base 45 across the front portion 33 A. In the wedge-shaped beam body 55, the first wedge inclined surface 57A on the front surface side is in contact with the receiving inclined surface 43B of the first projecting wall portion 45A of the fixed base 45, and the second wedge inclined surface on the rear surface side. The descent stops when 57B is in contact with the receiving inclined surface 43A of the pressurized gas introduction pipe flange portion 35. Here, since the wedge-shaped beam body 55 is movable in the vertical direction as described above, the weight of the wedge-shaped beam body 55 is applied to the receiving inclined surfaces 43B and 43A from the wedge inclined surfaces 57A and 57B. The vertical downward force due to its own weight is converted into a horizontal force. That is, the second wedge inclined surface 57 B on the rear surface side pushes the receiving inclined surface 43 A of the pressurized gas introduction pipe flange portion 35 backward, and is separated from the molds 1 A and 1 B with respect to the pressurized gas introduction pipe 33. Give force in the direction. On the other hand, the wedge inclined surface 57A on the front side presses the receiving inclined surface 43B of the first projecting wall portion 45A of the fixed base 45 forward, and as a reaction force, the wedge-shaped beam body 55 is moved backward (die 1A, 1B). Force in a direction away from the pressure), and the pressurized gas introduction pipe flange portion 35 is pushed backward through the wedge-shaped beam body 55. Accordingly, a force for urging the pressurized gas introduction pipe 33 outward from the mold is always given by the weight of the wedge-shaped beam body 55. Then, by this urging force, the outer diameter enlarged portion 36 of the pressurized gas introduction pipe 33 is constantly pressed toward the end edges of the recesses 38A and 38B at the peripheral edge of the mold, and the position is fixed and maintained.
[0037]
As described above, each member is set at a predetermined position, and the molds 1A and 1B are heated to the superplastic temperature range, and are inert from the pressurized gas supply pipe 41 through the pressurized gas introduction pipe 33. If pressurized gas such as gas is blown between the upper and lower superplastic metal plates 3A and 3B from the nozzle portion 37, the superplastic metal plates 3A and 3B can be blow-molded by the gas pressure. When the pressurized gas is blown between the superplastic metal plates 3A and 3B, the reaction force of the pressurized gas gives the pressurized gas introduction pipe 33 a force in the direction of exiting from the molds 1A and 1B. As described above, the outer diameter enlarged portion 36 of the pressurized gas introduction pipe 33 is located inside the mold inner end edges of the recesses 38A and 38B at the peripheral edge portions of the molds 1A and 1B, and the position is fixed and maintained. Therefore, the pressurized gas introduction pipe 33 is prevented from coming out to the outside.
[0038]
Here, in the high-temperature atmosphere in the superplastic temperature range, the distance between the first projecting wall 45A of the fixed base 45 and the pressurized gas introduction pipe flange 35 may change due to displacement due to thermal expansion. Since the wedge-shaped beam body 55 inserted between them continuously applies a force in the direction of separating from the molds 1A and 1B to the pressurized gas introduction tube 33 by its own weight, it is affected by displacement due to thermal expansion. Instead, the pressurized gas introduction pipe 33 is always urged outward from the mold, and the outer diameter enlarged portion 36 is continuously pressed against the inner edge of the mold in the recesses 38A and 38B at the peripheral edge of the mold.
[0039]
As a result of preventing the pressurized gas introduction pipe 33 from moving as described above, it is also possible to prevent a gap from being generated between the pressurized gas introduction pipe 33 and the superplastic metal plates 3A and 3B above and below the pressurized gas introduction pipe 33. In addition, it is possible to effectively prevent a situation in which the pressurized gas leaks to the outside through the gap.
[0040]
In the embodiment shown in FIGS. 1 to 4, wedge inclined surfaces are formed on both front and rear surfaces of the wedge-shaped beam body 55, but as is apparent from the above description, only one of the front and rear surfaces is used. Even if the wedge inclined surface is formed, the urging force in the direction away from the molds 1A and 1B can be applied to the pressurized gas introduction pipe 33. However, in this case, of the front and rear surfaces of the wedge-shaped beam body 55, the surface that is not the wedge inclined surface is a vertical surface, and the corresponding front surface of the pressurized gas introduction pipe flange portion 35 or the first of the fixed base 45. The rear surface of the protruding wall portion 45A is also a vertical surface. Of course, as shown in the embodiment, the case where the front and rear surfaces of the wedge-shaped beam body 55 are wedge inclined surfaces is more reliable and more stable than the case where only one surface is a wedge inclined surface. 33 can always be urged outward from the mold.
[0041]
1 to 4, the wedge-shaped beam body 55 is supported by the support arms 53A and 53B protruding from the upper mold 1A. In such a configuration, the upper mold 1A is lowered to form the mold. When closing the wedge, the wedge-shaped beam body 55 is also lowered and set at a predetermined position, so that the setting operation is simple and easy. However, in some cases, the wedge-shaped beam body 55 is separated from the upper mold 1A. Of course, it may be suspended from above by a suspension member such as a wire.
[0042]
In addition, in the above place, as shown in FIG. 5, the outer diameter R of the outer diameter expansion part 36 of the pressurized gas introduction pipe 33 ₁ Is usually the inner diameter R of the recesses 38A, 38B at the peripheral edge of the mold 1A, 1B. ₂ Although it is desirable that the thickness be larger, the outer diameter R of the outer diameter enlarged portion 36 is considered in consideration of the thickness t of the superplastic metal plates 3A and 3B. ₁ In short, the following formula
R ₁ > R ₂ -2t
Should be satisfied.
[0043]
FIG. 6 shows another embodiment in which a part of the embodiment shown in FIGS.
[0044]
In FIG. 6, a horizontal rotation support shaft 59 that penetrates and traverses the groove-like recess 45 D of the second protruding wall portion 45 B at the rear end of the fixed base 45 is provided. On the other hand, a rotating support substrate 61 protruding downward is fixed to the rear portion 33B of the pressurized gas introduction tube 33. The major axis direction of the rotation support substrate 61 is that of the pressurized gas introduction tube 33. A long hole 63 extending in a direction parallel to the length direction is formed so as to penetrate therethrough, and the above-described support shaft 59 is inserted into the long hole 63 so as to be relatively rotatable.
[0045]
In such a structure, the pressurized gas introduction pipe 33 is attached to the second projecting wall portion 45B of the fixed base 45 so as to be tiltable about the support shaft 59. Therefore, the pressurized gas introduction pipe 33 can be easily set at a required position with one behavior even during the preparatory work. That is, the upper die 1A is raised to open the die, and the lower superplasticity is lowered with the pressurized gas introduction tube 33 tilted so that the nozzle portion 37 faces upward as shown by the chain line in FIG. The metal plate 3B is placed on the lower mold 1B, and then the pressurized gas introduction tube 33 is rotated counterclockwise to place the nozzle portion 37 on the superplastic metal plate 3B. In the same manner as in the embodiment of FIG. 4, after placing the upper superplastic metal plate 3A, the upper mold 1A is lowered and the mold is clamped. Since the pressurized gas introduction pipe 33 is supported by the support shaft 59 at the portion of the elongated hole 63, movement in the front-rear direction (direction approaching / separating from the molds 1A and 1B) is allowed, and therefore, at the time of blow molding Even when the molds 1A, 1B and the fixed base 45 are displaced due to thermal expansion, the pressurized gas introduction pipe 33 is given a force for urging backward by the weight of the wedge-shaped beam body 55 described above. That is, even if the position of the second projecting wall portion 45B of the fixed base 45 is displaced due to thermal expansion, the pressurized gas introduction pipe 33 does not move thereby.
[0046]
In the above description, the weight of the wedge-shaped beam body 55 is used as the urging means for urging the pressurized gas introduction pipe 33 outward from the mold, but the urging means is not limited to this. For example, a spring or the like can be used.
[0047]
FIG. 7 shows a main portion of a superplastic forming apparatus according to still another embodiment of the present invention, that is, an embodiment corresponding to the invention of claim 4.
[0048]
In FIG. 7, the outer diameter enlarged portion 36 of the pressurized gas introduction tube 33 is located slightly outward from the tip of the nozzle portion 37, that is, a portion sandwiched between the peripheral portions of the upper and lower dies 1 A and 1 B ( Formed between the bead portions 31A and 31B). On the other hand, a recessed portion 71A is formed on the lower surface of the peripheral portion of the upper mold 1A (the lower surface of the bead portion 31A), and a recessed portion 71B is formed on the upper surface of the peripheral portion of the lower mold 1B (the upper surface of the bead portion 31B). In addition, the outer diameter enlarged portion 36 of the pressurized gas introduction pipe 33 is inserted between the concave and recessed portions 71A and 71B with the superplastic metal plates 3A and 3B interposed therebetween. A fixed base 45 is provided so as to protrude outward from the lower mold 1B. The fixed base 45 protrudes in the same manner as the second protruding wall portion 45B in the examples of FIGS. A wall 45B is formed, and the pressurized gas introduction pipe 33 can be tilted by the support shaft 59 and the long hole 63 and can be moved in the front-rear direction in the protruding wall 45B as in the example of FIG. It is supported.
[0049]
In such an embodiment of FIG. 7, the outer diameter enlarged portion 36 of the pressurized gas introduction tube 33 is held between the recessed portions 71A and 71B at the peripheral edge of the mold via the superplastic metal plates 3A and 3B. Therefore, the pressurized gas introduction pipe 33 is prevented from moving in the front-rear direction. Accordingly, similarly to the embodiment of FIGS. 1 to 4, the pressurized gas introduction pipe 33 is prevented from coming out of the mold, and the pressurized gas introduction pipe 33 is sandwiched by the movement of the pressurized gas introduction pipe 33. It is also possible to prevent a gap from being formed between the superplastic metal plates 3A and 3B.
[0050]
【The invention's effect】
According to the superplastic forming apparatus of the first aspect of the present invention, even when a force is applied to the pressurized gas introduction tube to the outside of the mold by the reaction force when the pressurized gas is introduced for blow molding, the pressurized gas Pressurized gas because the expanded outer diameter portion formed at the tip of the inlet tube is pressed against the edge of the recess at the inner edge of the mold via the superplastic metal plate, and the movement of the pressurized gas inlet tube is prevented. It is possible to reliably prevent the introduction pipe from slipping out. In addition, it is possible to prevent a gap from being generated between the pressurized gas introduction tube and the superplastic metal plate sandwiching the pressurized gas introduction tube by the movement of the pressurized gas introduction tube, so that the pressurized gas leaks from the gap to the outside. It is possible to effectively prevent a situation in which molding becomes difficult due to insufficient pressurization.
[0051]
According to the superplastic forming apparatus of the second aspect of the invention, the pressurized gas introduction pipe is always applied with the urging force to the outside of the mold, and the outer diameter enlarged portion of the pressurized gas introduction pipe is always the periphery of the mold. Because it is forcibly pressed against the inner edge of the mold in the concave part of the part, the position of the pressurized gas introduction pipe can be securely fixed and maintained, so that the above-mentioned effects can be exhibited more stably and reliably. Can be made.
[0052]
Further, according to the superplastic forming apparatus of the invention of claim 3, the aforementioned urging force is given by the dead weight of the wedge-shaped beam body, and the displacement due to the thermal expansion does not affect the urging force. It is possible to reliably prevent the pressurized gas introduction pipe from moving due to the influence of the displacement.
[0053]
Further, in the superplastic forming apparatus of the invention of claim 4, the outer diameter enlarged portion of the pressurized gas introduction tube is fitted between the recessed portions of the peripheral portions of the upper and lower molds, and the position is fixed and maintained. The same effect as in the first aspect can be obtained.
[Brief description of the drawings]
FIG. 1 is a longitudinal side view showing a main part of a superplastic forming apparatus according to an embodiment of the present invention.
FIG. 2 is a longitudinal sectional view taken along line II-II in FIG.
3 is a longitudinal sectional view taken along line III-III in FIG.
4 is an exploded perspective view of the apparatus of the embodiment shown in FIG. 1. FIG.
FIG. 5 is a schematic illustration showing an enlarged view of the situation near the tip of the pressurized gas introduction tube in the embodiment shown in FIG. 1;
FIG. 6 is a longitudinal side view showing a main part of a superplastic forming apparatus according to another embodiment of the present invention.
FIG. 7 is a longitudinal side view showing a main part of a superplastic forming apparatus of still another embodiment of the present invention.
FIG. 8 is a longitudinal sectional view showing an example of a structure of a pressurized gas introduction portion in a conventional superplastic expansion molding apparatus.
FIG. 9 is a longitudinal sectional view showing another example of a structure of a pressurized gas introduction portion in a conventional superplastic expansion molding apparatus.
[Explanation of symbols]
1A Upper mold
1B Lower mold
3A, 3B Superplastic metal plate
7 cavity
33 Pressurized gas introduction pipe
35 Flange
36 Increased outer diameter
38A, 38B recess
43A, 43B Receiving inclined surface
45 Fixed base
45A First protrusion
55 Wedge beam
55A Notch recess
57A, 57B Wedge inclined surface
59 Spindle
71A, 71B Recessed part

Claims

A plurality of superplastic metal plates are laminated and sandwiched between upper and lower molds so that the peripheral edge is sandwiched between the upper and lower mold peripheral edges, and between the superplastic metal plates from the edge of the upper and lower molds. In a superplastic forming apparatus in which the tip of a pressurized gas introduction tube is inserted and pressurized gas is introduced between the superplastic metal plates via the pressurized gas introduction tube to blow-mold the superplastic metal plate. ,
An outer diameter enlarged portion whose diameter increases along the direction from the outside of the mold to the inside of the mold is formed at the tip of the pressurized gas introduction tube, and the peripheral portions of the upper and lower molds are subjected to additional processing. A concave portion is formed that sandwiches the base tube portion closer to the outer side of the mold than the outer diameter enlarged portion of the pressurized gas introduction pipe with the superplastic metal plate interposed therebetween, and the end on the inner side of the mold in the concave portion A superplastic forming apparatus, characterized in that it is configured to prevent the pressurized gas introduction tube from moving toward the outside of the mold by the edge.

In the superplastic forming apparatus according to claim 1,
A superplastic forming apparatus comprising a biasing means for biasing the pressurized gas introduction pipe from the inside of the mold toward the outside.

In the superplastic forming apparatus according to claim 1,
A flange portion is formed at a portion outside the mold in the pressurized gas introduction pipe, and a fixed base for receiving the pressurized gas introduction pipe is formed on the lower mold so as to protrude from the lower mold, The fixed base is formed with a protruding wall portion having a recess in which a portion closer to the mold than the flange portion in the pressurized gas introduction tube is loosely fitted from above, and further, the flange portion of the pressurized gas introduction tube Between the projecting wall of the fixed base, a wedge-shaped beam in which at least one of the surface on the mold side and the surface on the opposite side of the mold has a wedge inclined surface and can be lowered by its own weight The body is inserted from above so as to straddle the pressurized gas introduction pipe, and at least one of the flange portion and the projecting wall portion is in contact with the wedge inclined surface along the wedge inclined surface of the wedge-shaped beam body An inclined surface for receiving is formed, and these flange, fixed base and It said biasing means by the wedge-shaped beam body, characterized in that it is configured, superplastic forming apparatus.

A plurality of superplastic metal plates are laminated and sandwiched between upper and lower molds so that the peripheral edge is sandwiched between the upper and lower mold peripheral edges, and between the superplastic metal plates from the edge of the upper and lower molds. In a superplastic forming apparatus in which the tip of a pressurized gas introduction tube is inserted and pressurized gas is introduced between the superplastic metal plates via the pressurized gas introduction tube to blow-mold the superplastic metal plate. ,
An outer diameter enlarged portion is formed in a portion sandwiched between the peripheral edges of the mold in the pressurized gas introduction tube, and the outer diameter is in a state where a superplastic metal plate is interposed between the peripheral edges of the upper and lower molds. A superplastic forming device characterized in that a recessed portion into which the enlarged portion is inserted is formed.