JP2004190837A

JP2004190837A - Fastening member, product using the fastening member, male screw, and manufacturing method thereof

Info

Publication number: JP2004190837A
Application number: JP2002362506A
Authority: JP
Inventors: Hideo Okada; 英生岡田; Hirosuke Sakai; 宏祐酒井
Original assignee: Sharp Corp
Current assignee: Sharp Corp
Priority date: 2002-12-13
Filing date: 2002-12-13
Publication date: 2004-07-08

Abstract

【課題】形状回復時に雄ねじと雌ねじの干渉を確実に防止して簡単に離脱させる。
【解決手段】形状回復温度と形状回復方向がほぼ同一である形状記憶素材から雄ねじおよび雌ねじが形成され、雄ねじと雌ねじの螺合によって被締結部品Ａ，Ｂの締結を行う。そして、雄ねじが形状回復した際の雄ねじ母材２Ａのねじ形成部２２Ａは、ネジのない、雄ねじのネジの有効径と略同等の外径ｄ２の筒状となり、雌ねじが形状回復した際の雌ねじ母材３Ａのねじ形成部３２Ａは、ネジのない、雌ねじのネジの有効径と略同等の穴径Ｄ２の穴状となる。
【選択図】図２An object of the present invention is to reliably prevent interference between a male screw and a female screw at the time of shape recovery and to easily remove the male screw and the female screw.
A male screw and a female screw are formed from a shape memory material having substantially the same shape recovery temperature and shape recovery direction, and the parts A and B are fastened by screwing the male screw and the female screw. Then, the thread forming portion 22A of the male screw base material 2A when the shape of the male screw recovers has a cylindrical shape with no screw and an outer diameter d2 substantially equal to the effective diameter of the screw of the male screw, and the female screw when the shape of the female screw recovers The thread forming portion 32A of the base material 3A has a hole shape having a hole diameter D2 substantially equal to an effective diameter of a female screw having no screw.
[Selection] Fig. 2

Description

【０００１】
【発明の属する技術分野】
本発明は、形状記憶素材製の雄ねじと雌ねじからなる締結部材および締結部材を利用した製品ならびに形状記憶素材製の雄ねじおよびその製造方法に関するものである。
【０００２】
【従来の技術】
一般に、部品を本体に締結する場合には、ねじが用いられる。例えば、人手により、ねじを締め付ける方向に回して部品などを締結する一方、修理や解体のため、ねじを弛める方向に回して部品などを分離するようにしている。
【０００３】
ところで、近年、環境問題の高まりの中、製品のリサイクルの容易さが重要な要素になっている。製品のリサイクルを容易に達成するためには、締結部の解体性の向上が不可欠となる。
【０００４】
このような締結部の解体の容易さを向上させるため、形状記憶素材によって製造されたねじが提案されている。ここで、形状記憶素材とは、熱を加えることによって形状回復温度に達すると、予め形状記憶された状態に戻る性質を有する素材であって、例えば、ニッケルとチタンの合金（ニチノール）が知られている。
【０００５】
例えば、図１２に示すように、被締結部品Ｘを被締結部品Ｙに締結する場合、形状記憶素材によって製造された雄ねじ１０を用意するとともに、該雄ねじ１０と螺合可能な雌ねじ２０を被締結部品Ｙに設け、被締結部品Ｘを通して雄ねじ１０を被締結部品Ｙの雌ねじ２０に螺合するものである。
【０００６】
ここで、雄ねじ１０は、図１４に示す雄ねじ母材１０Ａ、すなわち、ネジのない筒状のねじ形成部１０１Ａが形状記憶されており、その外径ｄ０は、雌ねじ２０の内径Ｄ１より小さく設定されている。
【０００７】
したがって、図１２に示す状態で雄ねじ１０が加熱されて形状記憶回復温度に達すると、図１３に示すように、雄ねじ１０は、形状記憶した筒状のねじ形成部１０１Ａを有する雄ねじ母材１０Ａに回復する。この時の雄ねじ母材１０Ａのねじ形成部１０１Ａの外径ｄ０は、雌ねじ２０の内径Ｄ１より小さいため、締結が解除され、被締結部品Ｘと被締結部品Ｙが解体される（例えば、特許文献１参照）。
【０００８】
【特許文献１】
特開平８−６１３４６号公報
【０００９】
【発明が解決しようとする課題】
しかしながら、前述した雄ねじ１０は、雄ねじ母材１０Ａの形状記憶時のねじ形成部１０１Ａの外径ｄ０を雌ねじ２０の内径Ｄ１以下とし、軸方向への圧縮によりねじ形成部１０１Ａの外径を雄ねじ１０の有効径程度まで変形させた後、転造によりネジを形成することによって製造される。
【００１０】
したがって、雄ねじ１０が加熱されて形状記憶回復温度に達し、形状記憶した筒状のねじ形成部１０１Ａを有する雄ねじ母材１０Ａに回復する際、ネジがなくなると同時に、ねじ形成部１０１Ａの長さが長くなる。この結果、形状回復途中のネジのピッチが変化し、螺合する雌ねじ２０のネジのピッチと合わなくなり、雄ねじ２０のネジと雌ねじ２０のネジとが干渉して外れなくなるという問題があった。
【００１１】
本発明は、このような問題点に鑑みてなされたものであり、形状回復時に雄ねじと雌ねじの干渉を確実に防止して簡単に離脱させることのできる雄ねじと雌ねじからなる締結部材および締結部材を利用した製品を提供するものである。
【００１２】
また、本発明は、形状回復時に雄ねじと雌ねじの干渉を確実に防止して簡単に締結を解除することのできる雄ねじおよびその製造方法を提供するものである。
【００１３】
【課題を解決するための手段】
本発明は、雄ねじおよび雌ねじの螺合により締結を行う締結部材において、前記雄ねじおよび雌ねじは、形状回復温度と形状回復方向がほぼ同一である形状記憶素材からなり、かつ、形状回復時における雄ねじ母材のねじ形成部および雌ねじ母材のねじ形成部がそれぞれネジのない筒状および穴状であり、それらのねじ形成部の外径および穴径がそれぞれ雄ねじおよび雌ねじの有効径とほぼ等しいことを特徴とするものである。
【００１４】
本発明によれば、雄ねじおよび雌ねじは、同一特性の形状記憶素材、すなわち、形状記憶回復開始温度や形状記憶状態に戻る方向が同一である形状記憶素材から形成されているために、形状回復時において、雄ねじのネジと雌ねじのネジが干渉することなく確実に形態を変化させることができる。そして、雄ねじが雄ねじ母材に、雌ねじが雌ねじ母材にそれぞれ形状が回復した場合、雄ねじ母材のねじ形成部が雄ねじの有効径とほぼ同一径のネジのない筒状となり、また、雌ねじ母材のねじ形成部が雌ねじの有効径とほぼ同一径のネジのない穴状となることから、雄ねじ母材を雌ねじ母材から離脱させることができる。
【００１５】
本発明において、前記雌ねじの形状回復時における雌ねじ母材のねじ形成部の穴径が雄ねじの形状回復時におけるねじ形成部の外径よりも大きいと、雄ねじが雄ねじ母材に、雌ねじが雌ねじ母材にそれぞれ形状が回復した場合、雄ねじ母材を雌ねじ母材から簡単に離脱させることができるため、好ましい。
【００１６】
本発明において、前記形状記憶素材が形状記憶合金または形状記憶樹脂であることが好ましい。形状記憶合金としては、ＮｉＴｉ合金（ニチノール）、Ａｕ−Ｃｄなどが知られている。また、形状記憶樹脂としては、例えば、三菱重工業製の形状記憶樹脂ダイアリーが市販されている。
【００１７】
本発明は、前記請求項１乃至３のいずれかに記載の締結部材を少なくとも１箇所に用いたことを特徴とするものである。
【００１８】
本発明によれば、締結部材を構成する雄ねじおよび雌ねじは、同一特性の形状記憶素材、すなわち、形状記憶回復開始温度や形状記憶状態に戻る方向が同一である形状記憶素材、例えば、形状記憶合金や形状記憶樹脂から形成されているために、形状回復時において、雄ねじのネジと雌ねじのネジが干渉することなく形態を変化させることができる。そして、雄ねじが雄ねじ母材に、雌ねじが雌ねじ母材にそれぞれ形状が回復した場合、雄ねじ母材のねじ形成部が雄ねじの有効径とほぼ同一径のネジのない筒状となり、また、雌ねじ母材のねじ形成部が雌ねじの有効径とほぼ同一径のネジのない穴状となることから、雄ねじ母材を雌ねじ母材から離脱させることができる。したがって、締結部材を用いて被締結部品同士を締結している場合、簡単に各被締結部品に解体することができる。
【００１９】
本発明において、前記締結部材の近傍に電磁波吸収素材または赤外線吸収素材を設けると、電磁波または赤外線を照射することにより、電磁波吸収素材または赤外線吸収素材を介して締結部材を簡単に加熱することができる。このため、締結部材を短時間で形状回復させることができる。
【００２０】
本発明は、頭部およびねじ部からなる形状記憶素材製の雄ねじであって、ねじ部の中心に空間を有し、形状回復温度まで加熱されると、ネジがなくなると同時に、ねじ部が外径の小さくなる方向に形状回復することを特徴とするものである。
【００２１】
本発明によれば、雄ねじが形状回復温度まで加熱された場合、雄ねじは、ネジのない、かつ、雄ねじの外径よりも小径の筒状のねじ形成部を有する雄ねじ母材に形状回復することから、雌ねじのネジに干渉することなく確実に形態を変化させることができる。このため、雄ねじ母材を雌ねじから簡単に離脱させることができる。
【００２２】
本発明は、頭部およびねじ部からなる形状記憶素材製の雄ねじであって、ねじ部の中心に空間を有し、形状回復温度まで加熱されると、ネジがなくなると同時に、ねじ部が略逆円錐形状に形状回復することを特徴とするものである。
【００２３】
本発明によれば、雄ねじが形状回復温度まで加熱された場合、雄ねじは、ネジのない、かつ、略逆円錐形状のねじ形成部を有する雄ねじ母材に形状回復することから、雌ねじのネジに干渉することなく確実に形態を変化させることができる。このため、雄ねじ母材を雌ねじから簡単に離脱させることができる。
【００２４】
本発明は、請求項６または７記載の雄ねじの製造方法であって、雄ねじの有効径と同程度の径を有する下型の穴に形状記憶された雄ねじ母材のねじ形成部を遊嵌して上型で保持した後、雄ねじ母材を加熱し、雄ねじ母材のねじ形成部の外径を前記下型の穴の径まで拡開させ、次いで、ねじ形成部にネジを転造することを特徴とするものである。
【００２５】
本発明によれば、雄ねじの有効径と同程度の径を有する下型の穴に形状記憶された雄ねじ母材のねじ形成部を遊嵌して上型で保持した後、雄ねじ母材を加熱し、雄ねじ母材のねじ形成部の外径を前記下型の穴の径まで拡開させ、次いで、ねじ形成部にネジを転造することにより、雌ねじのネジに干渉することなく確実に形態を変化させることのできる雄ねじを簡単に製造することができる。
【００２６】
【発明の実施の形態】
以下、本発明の実施の形態を図面に基づいて説明する。
【００２７】
図１には、本発明の締結部材１、すなわち、形状記憶素材製の雄ねじ２および雄ねじ２に螺合可能であって、形状記憶素材製の雌ねじ３から構成された締結部材１の一実施形態が示されている。
【００２８】
この形状記憶素材、例えば、形状記憶合金あるいは形状記憶樹脂製の雄ねじ２は、頭部２１および該頭部２１と一体のねじ部２２からなり、雄ねじ２を形状回復温度に加熱すると、図２に示すように、ネジがなくなると同時に、外径が縮小する方向に形状回復し、ネジのない筒状のねじ形成部２２Ａを有する雄ねじ母材２Ａとなる。
【００２９】
一方、雌ねじ３は、ねじ部３２を有し、雄ねじ２と同一特性、すなわち、形状回復開始温度や形状回復方向が同一の形状記憶素材から形成されている。そして、雌ねじ３を形状回復温度に加熱すると、図２に示すように、ネジがなくなると同時に、穴径が拡大する方向に形状回復し、ネジのない穴状のねじ形成部３２Ａを有する雌ねじ母材３Ａとなる。
【００３０】
このような雄ねじ２および雌ねじ３からなる締結部材１によって、被締結部品Ｘを被締結部品Ｙに締結して製品Ｚを製造する場合は、図１に示すように、予め被締結部品Ｙに雌ねじ３を圧入しておき、被締結部品Ｘを通して雄ねじ２を雌ねじ３に螺合させて締め付けることにより、被締結部品Ｘおよび被締結部品Ｙを締結して製品Ｚを得ることができる。
【００３１】
ここで、雄ねじ２が形状記憶された雄ねじ母材２Ａに回復した場合、そのねじ形成部２２Ａの外径をｄ２（図２参照）、雄ねじ２のねじ部２２の外径をｄ、その谷の径をｄ１とするとき（図３（ａ）参照）、ｄ２＝（ｄ＋ｄ１）／２である。
【００３２】
同様に、雌ねじ３が形状記憶された雌ねじ母材３Ａに回復した場合、そのねじ形成部３２Ａの穴径をＤ２（図２参照）、雌ねじ３のねじ部３２の谷の径をＤ、内径をＤ１とするとき（図３（ａ）参照）、Ｄ２＝（Ｄ＋Ｄ１）／２である。また、雄ねじ母材２Ａのねじ形成部２２Ａの外径ｄ２は、雌ねじ母材３Ａのねじ形成部３２Ａの穴径Ｄ２よりもわずかに小さく設定されている。
【００３３】
なお、雄ねじ２のねじ部２２は、転造、すなわち、雄ねじ２のネジと同じ山形、同じピッチのネジを刻んだ転造ダイスによって雄ねじ母材２Ａのねじ形成部２２Ａを挟み込み、その表面に転造ダイスを押し付けて転がすことによって形成される。
【００３４】
また、雌ねじ３のねじ部３２は、雌ねじ３と螺合可能なボルトを雌ねじ母材３Ａのねじ形成部３２Ａの穴に挿入し、ねじ形成部３２Ａを半径方向に加圧することによって形成される。
【００３５】
このように構成された締結部材１の形状回復過程について説明する。
【００３６】
図１に示したように、被締結部品Ｘを通して雄ねじ２を被締結部品Ｙに圧入された雌ねじ３に螺合させ、被締結部品Ｘおよび被締結部品Ｙを締結している状態において、締結部材１を外部より加熱する。そして、雄ねじ２および雌ねじ３が形状回復温度に達すれば、雄ねじ２および雌ねじ３は、同時に形状を回復する。
【００３７】
この場合、図３（ａ）に示すように、雄ねじ２のネジのうち、山部分は、実線矢印で示すように、山の頂点が低くなる方向に、谷部分は、実線矢印で示すように、谷の底が高くなる方向にそれぞれ変形を開始する。一方、雌ねじ３のネジのうち、谷部分は、破線矢印で示すように、谷の底が高くなる方向に、山部分は、破線矢印で示すように、山の頂点が低くなる方向にそれぞれ変形を開始する。
【００３８】
さらに、加熱されると、このような変形が継続され（図３（ｂ）参照）、ついには、雄ねじ２が、ネジのない筒状のねじ形成部２２Ａを有する雄ねじ母材２Ａに形態を変化し、また、雌ねじ３が、ネジのない穴状のねじ形成部３２Ａを有する雌ねじ母材３Ａに形態を変化する（図３（ｃ）参照）。
【００３９】
このように、雄ねじ２および雌ねじ３は、形状記憶回復開始温度や形状記憶状態に戻る方向が同一であるために、雄ねじ２のネジと雌ねじ３のネジが干渉することなく確実に形態を変化させることができる。そして、雄ねじ母材２Ａおよび雌ねじ母材３Ａに形状が回復した場合、雄ねじ母材２Ａの外径ｄ２は、雌ねじ母材３Ａの穴径Ｄ２よりも小さいため、雄ねじ母材２Ａを雌ねじ母材３Ａから簡単に離脱させることができ、被締結部品Ｘと被締結部品Ｙとの締結を解除することができる。
【００４０】
例えば、携帯電話において、本体側に本発明の締結部材１を構成する雌ねじ３を設け、本発明の締結部材１を構成する雄ねじ２を介して締結しようとする部品を本体側に締結すると、携帯電話を所定の温度に加熱することにより、雄ねじ２と雌ねじ３の締結が解除され、簡単に本体側から締結した部品を離脱させることができる。
【００４１】
なお、本発明の締結部材１を用いた製品Ｚにおいて、図４に示すように、フェライトや炭化珪素などの電磁波吸収素材４を被締結部材１の周辺に設けることにより、電子レンジなどにより電磁波を照射して、雄ねじ２や雌ねじ３を効果的に加熱できることから、製品Ｚを素早く解体することができる。
【００４２】
また、図５に示すように、赤外線吸収素材５（例えば、三井化学ファイン株式会社製近赤外線吸収剤（Near IR Absorber )など) を被締結部材１の周辺に設けることにより、赤外加熱炉で赤外光を照射して、雄ねじ２や雌ねじ３を効果的に加熱できることから、製品Ｚを素早く解体することができる。
【００４３】
次に、本発明の雄ねじ６について説明する。
【００４４】
図６には、本発明の形状記憶素材、例えば、形状記憶樹脂からなる雄ねじ６の一実施形態が示されている。
【００４５】
この雄ねじ６は、頭部６１および該頭部６１と一体のねじ部６２からなり、ねじ部６２の中心には、穴６２１が形成されている。そして、雄ねじ６を形状回復温度に加熱すると、図７に示すように、ネジがなくなると同時に、外径が縮小する方向に形状回復し、ネジのない筒状のねじ形成部６２Ａを有する雄ねじ母材６Ａとなる。
【００４６】
次に、このように構成された雄ねじ６の形成手順について説明する。
【００４７】
図７において、雄ねじ母材６Ａは、頭部６１Ａと、頭部６１Ａと一体に成形され、ネジのない筒状のねじ形成部６２Ａからなり、ねじ形成部６２Ａには、その中心に穴６２１Ａが形成されている。
【００４８】
ここで、雄ねじ母材６Ａのねじ形成部６２Ａの外径ｄ０は、雄ねじ６のネジの谷の径ｄ１よりも小さく設定されている。
【００４９】
なお、ねじ形成部６２Ａの中心に形成された穴６２１Ａは、ドリルなどによって後加工してもよいし、雄ねじ母材６Ａを成形する際に同時に形成してもよい。
【００５０】
雄ねじ母材６Ａが成形されたならば、雄ねじ６の有効径程度の穴１１ａを有する下型１１に雄ねじ母材６Ａのねじ形成部６２Ａを配置し、上型１２で雄ねじ母材６Ａを保持する（図８（ａ）参照）。
【００５１】
この際、下型１１および上型１２をヒーターなどにより雄ねじ母材６Ａの軟化開始温度（例えば、三菱重工業製形状記憶樹脂ダイアリーの場合には、形状回復温度−２０℃）〜形状回復温度未満の温度に加熱し、雄ねじ母材６Ａが軟化するまでその状態を保持する。
【００５２】
次いで、図８（ｂ）に示すように、下型１１の穴１１ａに連通する加工穴１１ｂから、先端が円錐形状のピン１３を挿通し、雄ねじ母材６Ａのねじ形成部６２Ａの中心に形成された穴６２１Ａに押し込む。このため、雄ねじ母材６Ａのねじ形成部６２Ａの穴６２１Ａは押し広げられ、合わせて、ねじ形成部６２Ａの外径が下型１１の穴１１ａの径まで拡大される（図８（ｃ）参照）。
【００５３】
ここで、ピン１３の外径は、雄ねじ６のねじ部６２の谷の径ｄ１よりも小さく設定されている。
【００５４】
この後、雄ねじ母材６Ａが軟化温度以下になるまでこの状態を保持する（図８（ｄ）参照）。
【００５５】
なお、下型１１および上型１２に冷風を供給して急冷させてもよい。
【００５６】
雄ねじ母材６Ａが軟化温度以下に達したならば、型開きして雄ねじ母材６Ａを取り出し、図８（ｅ）に示すように、雄ねじ母材６Ａの拡大された穴６２１Ａに、拡大された穴６２１Ａの形状と同じ形状のジグ１４を取り付け、ねじ形成部６２Ａにネジを転造する。すなわち、雄ねじ６のネジと同じ山形、同じピッチのネジを刻んだ転造ダイス１５によって雄ねじ母材６Ａのねじ形成部６２Ａを挟み込み、その表面に転造ダイスを押し付けて転がすことによってネジを形成する。
【００５７】
このとき、雄ねじ母材６Ａを、雄ねじ母材６Ａの軟化開始温度（例えば、三菱重工業製形状記憶樹脂ダイアリーの場合には、形状回復温度−２０℃）〜形状回復温度未満の温度に加熱する。その後、ネジを転造しながら軟化温度以下に冷却する。
【００５８】
この様にして成形された雄ねじ６は、形状回復温度に加熱されると、ネジがなくなると同時に、外径が縮小する方向に形状を回復する。このため、形状回復時にネジが雌ねじ２０（図１２参照）のネジに食いつくことがなく、容易に雌ねじ２０から離脱させることができる。また、中実のものよりも体積が小さいため、加熱し易く、解体時に消費するエネルギーを削減することができるとともに、材料費を節約することができる。
【００５９】
図９には、本発明の形状記憶樹脂からなる雄ねじ６の他の実施形態が示されている。
【００６０】
この雄ねじ６も、頭部６１および該頭部６１と一体のねじ部６２からなり、ねじ部６２の中心には、円錐形状の穴６２２が形成されている。そして、雄ねじ６を形状回復温度に加熱すると、図１０に示すように、ネジがなくなると同時に、外径が縮小する方向に形状回復し、ネジのない逆円錐形状のねじ形成部６２Ｂを有する雄ねじ母材６Ｂとなる。
【００６１】
次に、このように構成された雄ねじ６の形成手順について説明する。
【００６２】
図１０において、雄ねじ母材６Ｂは、頭部６１Ｂと、ネジのない逆円錐形状のねじ形成部６２Ｂからなり、ねじ形成部６２Ｂは、その中心に穴６２２Ｂが形成されている。
【００６３】
ここで、雄ねじ母材６Ｂのねじ形成部６２Ｂの外径ｄ０は、雄ねじ６のネジの谷の径ｄ１よりも小さく設定されている。
【００６４】
なお、ねじ形成部６２Ｂの中心に形成された穴６２２Ｂは、ドリルなどによって後加工してもよいし、雄ねじ母材６Ｂを成形する際に同時に形成してもよい。
【００６５】
雄ねじ母材６Ｂが成形されたならば、雄ねじ６の有効径程度の穴１１ａを有する下型１１に雄ねじ母材６Ｂのねじ形成部６２Ｂを配置し、上型１２で雄ねじ母材６Ｂを保持する（図１１（ａ）参照）。
【００６６】
この際、下型１１および上型１２をヒーターなどにより雄ねじ母材６Ｂの軟化開始温度（例えば、三菱重工業製形状記憶樹脂ダイアリーの場合には、形状回復温度−２０℃）〜形状回復温度未満の温度に加熱し、雄ねじ母材６Ｂが軟化するまでその状態を保持する。
【００６７】
次いで、図１１（ｂ）に示すように、下型１１に形成された穴１１ａに連通する加工穴１１ｂから、ねじ形成部６２Ｂのテーパー角度とほぼ同じテーパー角度の円錐形状のピン１６を挿通し、雄ねじ母材６Ｂのねじ形成部６２Ｂの中心に形成された穴６２２Ｂに押し込む。このため、雄ねじ母材６Ｂのねじ形成部６２Ｂの穴６２２Ｂは押し広げられ、ねじ形成部６２Ｂの外径が下型１１の穴１１ａの径まで拡大される（図１１（ｃ）参照）。
【００６８】
ここで、ピン１６の最大径は、雄ねじ６のネジの谷の径ｄ１よりも小さく設定されている。
【００６９】
この後、雄ねじ母材６Ｂが軟化温度以下になるまでこの状態を保持する（図１１（ｄ）参照）。
【００７０】
なお、下型１１および上型１２に冷風を供給して急冷させてもよい。
【００７１】
雄ねじ母材６Ｂが軟化温度以下に達したならば、型開きして雄ねじ母材６Ｂを取り出し、図１１（ｅ）に示すように、雄ねじ母材６Ｂの拡大された穴６２２Ｂに、拡大された穴６２２Ｂの形状と同じ形状のジグ１６を取り付け、雄ねじ形成部６２Ｂにネジを転造する。
【００７２】
このとき、雄ねじ母材６Ｂを、雄ねじ母材６Ｂの軟化開始温度（例えば、三菱重工業製形状記憶樹脂ダイアリーの場合には、形状回復温度−２０℃）〜形状回復温度未満の温度に加熱する。その後、ネジを転造しながら軟化温度以下に冷却する。
【００７３】
この様にして成形された雄ねじ６は、形状回復温度に加熱されると、ネジがなくなると同時に、径が縮小する方向に形状を回復する。このため、形状回復時にネジが雌ねじ２０のネジに食いつくことがなく、容易に雌ねじ２０から離脱させることができる。また、中実のものよりも体積が小さいため、加熱し易く、解体時に消費するエネルギーを削減することができるとともに、材料費を節約することができる。
【００７４】
なお、前述した実施形態においては、雄ねじ６に付いて説明したが、雄ねじ６に限らずねじ部を利用して締結する締結部材、例えば、ボルトなどにも適用することができる。
【００７５】
【発明の効果】
このように本発明によれば、形状回復時に雄ねじと雌ねじの干渉を確実に防止して簡単に離脱させることができる。
【図面の簡単な説明】
【図１】本発明の締結部材による被締結部品の締結状態を示す断面図である。
【図２】図１の被締結部品の締結状態において、締結部材が形状回復した状態を示す断面図である。
【図３】本発明の締結部材を構成する雄ねじと雌ねじの形状回復過程を一部省略して示す説明図である。
【図４】本発明の締結部材による被締結部品の他の締結状態を示す断面図である。
【図５】本発明の締結部材による被締結部品のもう一つの締結状態を示す断面図である。
【図６】本発明の雄ねじの一実施形態を示す断面図である。
【図７】図６の雄ねじの形状回復状態を示す断面図である。
【図８】図６の雄ねじの製造工程を説明する工程図である。
【図９】本発明の雄ねじの他の実施形態を示す断面図である。
【図１０】図９の雄ねじの形状回復状態を示す断面図である。
【図１１】図９の雄ねじの製造工程を説明する工程図である。
【図１２】従来の形状記憶素材製の雄ねじによる被締結部品の締結状態を示す断面図である。
【図１３】図１２の被締結部品の締結状態において、雄ねじが形状回復した状態を示す断面図である。
【図１４】図１２の形状記憶素材製の雄ねじの形状回復状態を示す断面図である。
【符号の説明】
１締結部材
２，６雄ねじ
２Ａ，６Ａ，６Ｂ雄ねじ母材
２１，６１，６１Ａ，６１Ｂ頭部
２２，６２ねじ部
６２１，６２２穴
２２Ａ，６２Ａ，６２Ｂねじ形成部
６２１Ａ，６２２Ｂ穴
３雌ねじ
３Ａ雌ねじ母材
３２ねじ部
３２Ａねじ形成部
４電磁波吸収素材
５赤外線吸収素材
１１下型
１１ａ穴
１２上型
１３，１６ピン
１４，１７ジグ[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a fastening member comprising a male screw and a female screw made of a shape memory material, a product using the fastening member, a male screw made of a shape memory material, and a method of manufacturing the same.
[0002]
[Prior art]
Generally, screws are used to fasten components to the body. For example, a screw is manually turned to tighten a part to fasten a part or the like, and for repair or disassembly, the screw is turned to a loosening direction to separate the part or the like.
[0003]
By the way, in recent years, with increasing environmental problems, ease of product recycling has become an important factor. In order to easily achieve product recycling, it is essential to improve the disassembly of the fastening part.
[0004]
In order to improve the ease of disassembly of such a fastening portion, a screw manufactured from a shape memory material has been proposed. Here, the shape memory material is a material having a property of returning to a shape memory state in advance when a shape recovery temperature is reached by applying heat. For example, an alloy of nickel and titanium (Nitinol) is known. ing.
[0005]
For example, as shown in FIG. 12, when a part X to be fastened is fastened to a part Y to be fastened, a male screw 10 made of a shape memory material is prepared, and a female screw 20 which can be screwed with the male screw 10 is fastened. The external thread 10 is provided on the component Y, and the external thread 10 is screwed into the internal thread 20 of the component Y through the component X.
[0006]
Here, the male screw 10 has a shape memory of a male screw base material 10A shown in FIG. 14, that is, a cylindrical screw forming portion 101A having no screw, and the outer diameter d0 is set to be smaller than the inner diameter D1 of the female screw 20. ing.
[0007]
Therefore, when the male screw 10 is heated in the state shown in FIG. 12 and reaches the shape memory recovery temperature, as shown in FIG. 13, the male screw 10 is attached to the male screw base material 10A having the cylindrical screw forming portion 101A having the shape memory. Recover. At this time, since the outer diameter d0 of the thread forming portion 101A of the male screw base material 10A is smaller than the inner diameter D1 of the female screw 20, the fastening is released and the parts X and Y are disassembled (for example, see Patent Document 1). 1).
[0008]
[Patent Document 1]
JP-A-8-61346 [0009]
[Problems to be solved by the invention]
However, in the above-described male screw 10, the outer diameter d0 of the thread forming portion 101A when the shape of the male screw base material 10A is stored is set to be equal to or less than the inner diameter D1 of the female screw 20, and the outer diameter of the screw forming portion 101A is reduced by axial compression. After it is deformed to the effective diameter of about, a screw is formed by rolling.
[0010]
Therefore, when the male screw 10 is heated to reach the shape memory recovery temperature and is recovered to the male screw base material 10A having the cylindrical screw forming portion 101A having the shape memory, the screw disappears and the length of the screw forming portion 101A is reduced. become longer. As a result, there is a problem that the pitch of the screw during the recovery of the shape is changed, does not match the pitch of the screw of the female screw 20 to be screwed, and the screw of the male screw 20 and the screw of the female screw 20 do not come off due to interference.
[0011]
The present invention has been made in view of such a problem, and a fastening member and a fastening member including a male screw and a female screw which can reliably prevent interference between a male screw and a female screw during shape recovery and can be easily separated. The product used is provided.
[0012]
Another object of the present invention is to provide a male screw which can reliably prevent interference between a male screw and a female screw at the time of shape recovery and can easily release the fastening, and a method of manufacturing the male screw.
[0013]
[Means for Solving the Problems]
The present invention relates to a fastening member for fastening by screwing a male screw and a female screw, wherein the male screw and the female screw are formed of a shape memory material having substantially the same shape recovery temperature and shape recovery direction, and a male screw thread at the time of shape recovery. The thread forming part of the material and the thread forming part of the internal thread base metal are cylindrical and hole-shaped without screws, respectively, and the outer diameter and hole diameter of those thread forming parts are almost equal to the effective diameters of male screw and female screw, respectively. It is a feature.
[0014]
According to the present invention, since the male screw and the female screw are formed of a shape memory material having the same characteristics, that is, a shape memory material having the same shape memory recovery start temperature and the same direction of returning to the shape memory state, In this case, the form can be reliably changed without interference between the male screw and the female screw. Then, when the shape of the male screw is restored to that of the male screw base material and the shape of the female screw is restored to that of the female screw base material, the thread forming portion of the male screw base material becomes a cylindrical shape without a screw having substantially the same diameter as the effective diameter of the male screw. Since the thread forming portion of the material has a hole shape without a screw having substantially the same diameter as the effective diameter of the female screw, the male screw base material can be separated from the female screw base material.
[0015]
In the present invention, when the hole diameter of the thread forming portion of the female screw base material at the time of the shape recovery of the female screw is larger than the outer diameter of the screw forming portion at the time of the shape recovery of the male screw, the male screw becomes the male screw base material, and the female screw becomes the female screw mother. It is preferable that the shape of each of the materials is restored because the male screw base material can be easily separated from the female screw base material.
[0016]
In the present invention, the shape memory material is preferably a shape memory alloy or a shape memory resin. As shape memory alloys, NiTi alloy (Nitinol), Au-Cd and the like are known. As the shape memory resin, for example, a shape memory resin diary manufactured by Mitsubishi Heavy Industries is commercially available.
[0017]
The present invention is characterized in that the fastening member according to any one of claims 1 to 3 is used at at least one place.
[0018]
According to the present invention, the male screw and the female screw constituting the fastening member are shape memory materials having the same characteristics, that is, a shape memory material in which the shape memory recovery start temperature and the direction of returning to the shape memory state are the same, for example, a shape memory alloy. Since it is formed from the shape memory resin, the form can be changed without interference between the male screw and the female screw at the time of shape recovery. Then, when the shape of the male screw is restored to that of the male screw base material and the shape of the female screw is restored to that of the female screw base material, the thread forming portion of the male screw base material becomes a cylindrical shape without a screw having substantially the same diameter as the effective diameter of the male screw. Since the thread forming portion of the material has a hole shape without a screw having substantially the same diameter as the effective diameter of the female screw, the male screw base material can be separated from the female screw base material. Therefore, when the parts to be fastened are fastened to each other by using the fastening member, the parts can be easily disassembled into the parts to be fastened.
[0019]
In the present invention, when an electromagnetic wave absorbing material or an infrared absorbing material is provided in the vicinity of the fastening member, the fastening member can be easily heated through the electromagnetic wave absorbing material or the infrared absorbing material by irradiating the electromagnetic wave or the infrared light. . Therefore, the shape of the fastening member can be recovered in a short time.
[0020]
The present invention relates to a male screw made of a shape memory material including a head and a screw part, which has a space in the center of the screw part, and when heated to a shape recovery temperature, the screw disappears and the screw part becomes outside at the same time. It is characterized in that the shape is recovered in the direction in which the diameter becomes smaller.
[0021]
According to the present invention, when the male screw is heated to the shape recovery temperature, the male screw has no screw and has a shape recovered to a male screw base material having a cylindrical screw forming portion having a smaller diameter than the outer diameter of the male screw. Therefore, the form can be surely changed without interfering with the female screw. Therefore, the male screw base material can be easily separated from the female screw.
[0022]
The present invention is a male screw made of a shape memory material including a head and a screw portion, has a space in the center of the screw portion, and when heated to a shape recovery temperature, the screw portion disappears and the screw portion is substantially removed. It is characterized by recovering the shape to an inverted conical shape.
[0023]
According to the present invention, when the male screw is heated to the shape recovery temperature, the male screw has no screw, and the shape of the male screw has a substantially inverted conical screw forming portion. The form can be reliably changed without interference. Therefore, the male screw base material can be easily separated from the female screw.
[0024]
The present invention is the method of manufacturing a male screw according to claim 6 or 7, wherein the thread forming portion of the male screw base material whose shape is memorized in the hole of the lower die having the same diameter as the effective diameter of the male screw is loosely fitted. After holding the male screw base material with the upper die, the outer diameter of the thread forming portion of the male screw base material is expanded to the diameter of the hole of the lower die, and then the screw is rolled into the screw forming portion. It is characterized by the following.
[0025]
According to the present invention, the male screw base material is heated after loosely fitting the thread forming portion of the male screw base material whose shape is stored in the hole of the lower die having a diameter substantially equal to the effective diameter of the male screw and holding the screw forming portion with the upper die. Then, the outer diameter of the thread forming portion of the male thread base material is expanded to the diameter of the hole of the lower die, and then the screw is rolled into the thread forming portion, thereby securely forming the thread without interfering with the thread of the female thread. It is possible to easily manufacture a male screw capable of changing the diameter.
[0026]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0027]
FIG. 1 shows an embodiment of the fastening member 1 of the present invention, that is, a fastening member 1 which can be screwed to a male screw 2 made of a shape memory material and a female screw 3 made of a shape memory material. It is shown.
[0028]
The male screw 2 made of a shape memory material, for example, a shape memory alloy or a shape memory resin, includes a head 21 and a screw portion 22 integrated with the head 21. When the male screw 2 is heated to a shape recovery temperature, the shape shown in FIG. As shown in the figure, at the same time as the screw disappears, the shape is recovered in the direction in which the outer diameter is reduced, and the male screw base material 2A having the cylindrical screw forming portion 22A having no screw is obtained.
[0029]
On the other hand, the female screw 3 has a thread portion 32 and is formed of a shape memory material having the same characteristics as the male screw 2, that is, the same shape recovery start temperature and shape recovery direction. Then, when the female screw 3 is heated to the shape recovery temperature, as shown in FIG. 2, at the same time as the screw disappears, the shape recovers in the direction in which the hole diameter increases, and the female screw mother having a screw-shaped hole forming portion 32A without a screw. Material 3A.
[0030]
When a product Z is manufactured by fastening the part X to be fastened to the part Y to be fastened by the fastening member 1 including the male screw 2 and the female screw 3 as shown in FIG. 3 is press-fitted, the male screw 2 is screwed into the female screw 3 through the fastened part X, and tightened, whereby the fastened part X and the fastened part Y are fastened to obtain the product Z.
[0031]
Here, when the male screw 2 recovers to the male screw base material 2A whose shape has been stored, the outer diameter of the screw forming portion 22A is d2 (see FIG. 2), the outer diameter of the screw portion 22 of the male screw 2 is d, When the diameter is d1 (see FIG. 3A), d2 = (d + d1) / 2.
[0032]
Similarly, when the internal thread 3 recovers to the internal thread base material 3A whose shape is stored, the hole diameter of the thread forming portion 32A is D2 (see FIG. 2), the root diameter of the thread portion 32 of the internal thread 3 is D, and the internal diameter is D. When D1 is set (see FIG. 3A), D2 = (D + D1) / 2. The outer diameter d2 of the thread forming portion 22A of the male screw base material 2A is set slightly smaller than the hole diameter D2 of the screw forming portion 32A of the female screw base material 3A.
[0033]
The threaded portion 22 of the male screw 2 is rolled, that is, the thread forming portion 22A of the male screw base material 2A is sandwiched by a rolling die in which a screw having the same mountain shape and the same pitch as the screw of the male screw 2 is cut, and is rolled on the surface thereof. It is formed by pressing and rolling a forming die.
[0034]
The screw portion 32 of the female screw 3 is formed by inserting a bolt that can be screwed into the female screw 3 into a hole of the screw forming portion 32A of the female screw base material 3A and pressing the screw forming portion 32A in the radial direction.
[0035]
The shape recovery process of the thus configured fastening member 1 will be described.
[0036]
As shown in FIG. 1, in a state where the male screw 2 is screwed into the female screw 3 press-fitted into the component Y through the component X, and the component X and the component Y are fastened, the fastening member is 1 is externally heated. When the male screw 2 and the female screw 3 reach the shape recovery temperature, the male screw 2 and the female screw 3 recover their shapes at the same time.
[0037]
In this case, as shown in FIG. 3 (a), among the screws of the male screw 2, the crest portion is in the direction in which the peak of the crest is lower as shown by the solid arrow, and the valley portion is as shown by the solid arrow. , The deformation starts in the direction in which the bottom of the valley becomes higher. On the other hand, among the threads of the female screw 3, the valley portion is deformed in the direction in which the bottom of the valley becomes higher, as indicated by the dashed arrow, and the crest portion is deformed in the direction in which the peak of the crest is lower, as indicated by the dashed arrow. To start.
[0038]
Further, when heated, such deformation is continued (see FIG. 3 (b)), and finally, the external thread 2 changes its form into an external thread base material 2A having a threaded cylindrical thread forming portion 22A. Then, the female screw 3 changes its form into a female screw base material 3A having a screw-shaped hole forming portion 32A without a screw (see FIG. 3C).
[0039]
As described above, since the male screw 2 and the female screw 3 have the same shape memory recovery start temperature and the same direction of returning to the shape memory state, the shapes of the male screw 2 and the female screw 3 are surely changed without interference. be able to. When the shapes of the male screw base material 2A and the female screw base material 3A are restored, the outer diameter d2 of the male screw base material 2A is smaller than the hole diameter D2 of the female screw base material 3A. Can be easily detached from each other, and the fastening between the parts X and Y can be released.
[0040]
For example, in a mobile phone, when a female screw 3 constituting the fastening member 1 of the present invention is provided on the main body side, and a component to be fastened via the male screw 2 constituting the fastening member 1 of the present invention is fastened to the main body side, By heating the telephone to a predetermined temperature, the fastening of the male screw 2 and the female screw 3 is released, and the fastened component can be easily removed from the main body side.
[0041]
In the product Z using the fastening member 1 of the present invention, as shown in FIG. 4, by providing an electromagnetic wave absorbing material 4 such as ferrite or silicon carbide around the member 1 to be fastened, electromagnetic waves can be emitted by a microwave oven or the like. Irradiation can effectively heat the male screw 2 and the female screw 3, so that the product Z can be quickly dismantled.
[0042]
Further, as shown in FIG. 5, by providing an infrared absorbing material 5 (for example, near infrared absorber (Near IR Absorber) manufactured by Mitsui Chemicals Fine Co., Ltd.) around the member 1 to be fastened, an infrared heating furnace is used. Since the male screw 2 and the female screw 3 can be effectively heated by irradiating infrared light, the product Z can be quickly disassembled.
[0043]
Next, the male screw 6 of the present invention will be described.
[0044]
FIG. 6 shows an embodiment of a male screw 6 made of a shape memory material, for example, a shape memory resin of the present invention.
[0045]
The male screw 6 includes a head portion 61 and a screw portion 62 integral with the head portion 61, and a hole 621 is formed at the center of the screw portion 62. Then, when the male screw 6 is heated to the shape recovery temperature, as shown in FIG. 7, at the same time as the screw disappears, the shape is recovered in the direction in which the outer diameter is reduced, and the male screw mother having a screw-shaped cylindrical screw forming portion 62A is provided. Material 6A.
[0046]
Next, a procedure for forming the male screw 6 configured as described above will be described.
[0047]
In FIG. 7, the male screw base material 6A includes a head 61A and a cylindrical screw forming portion 62A formed integrally with the head 61A and having no screw. The screw forming portion 62A has a hole 621A at the center thereof. Is formed.
[0048]
Here, the outer diameter d0 of the thread forming portion 62A of the male screw base material 6A is set to be smaller than the diameter d1 of the thread root of the male screw 6.
[0049]
The hole 621A formed at the center of the screw forming portion 62A may be post-processed by a drill or the like, or may be formed at the same time when the male screw base material 6A is formed.
[0050]
When the male screw base material 6A is formed, the thread forming portion 62A of the male screw base material 6A is arranged in the lower die 11 having a hole 11a having an effective diameter of the male screw 6, and the upper die 12 holds the male screw base material 6A. (See FIG. 8A).
[0051]
At this time, the lower mold 11 and the upper mold 12 are heated by a heater or the like to a softening start temperature of the male screw base material 6A (for example, in the case of a shape memory resin diary manufactured by Mitsubishi Heavy Industries, a shape recovery temperature −20 ° C.) to less than the shape recovery temperature. It is heated to a temperature and maintained in that state until the male screw base material 6A is softened.
[0052]
Next, as shown in FIG. 8 (b), a pin 13 having a conical tip is inserted through a processing hole 11b communicating with the hole 11a of the lower mold 11 to form a hole at the center of the thread forming portion 62A of the male screw base material 6A. Into the hole 621A. For this reason, the hole 621A of the thread forming portion 62A of the male screw base material 6A is pushed open, and at the same time, the outer diameter of the screw forming portion 62A is enlarged to the diameter of the hole 11a of the lower die 11 (see FIG. 8C). ).
[0053]
Here, the outer diameter of the pin 13 is set smaller than the root diameter d1 of the thread portion 62 of the male screw 6.
[0054]
Thereafter, this state is maintained until the male screw base material 6A becomes lower than the softening temperature (see FIG. 8D).
[0055]
Note that cold air may be supplied to the lower mold 11 and the upper mold 12 to be rapidly cooled.
[0056]
When the male screw base material 6A reaches the softening temperature or lower, the mold is opened and the male screw base material 6A is taken out, and as shown in FIG. 8 (e), the male screw base material 6A is enlarged to the enlarged hole 621A. The jig 14 having the same shape as the shape of the hole 621A is attached, and a screw is rolled into the screw forming portion 62A. That is, the thread forming portion 62A of the male screw base material 6A is sandwiched by the rolling dies 15 in which screws having the same angle and the same pitch as the screws of the male screw 6 are cut, and the rolling is performed by pressing the rolling dies against the surface thereof to form a screw. .
[0057]
At this time, the male screw base material 6A is heated to a temperature lower than the softening start temperature of the male screw base material 6A (for example, in the case of a shape memory resin diary manufactured by Mitsubishi Heavy Industries, -20 ° C.) to less than the shape recovery temperature. Thereafter, the screw is cooled to a softening temperature or lower while being rolled.
[0058]
When the male screw 6 formed in this manner is heated to the shape recovery temperature, the screw disappears and at the same time recovers its shape in the direction in which the outer diameter decreases. For this reason, the screw does not bite into the female screw 20 (see FIG. 12) at the time of shape recovery, and can be easily separated from the female screw 20. Further, since the volume is smaller than that of a solid material, the material is easily heated, energy consumed for disassembly can be reduced, and material costs can be reduced.
[0059]
FIG. 9 shows another embodiment of the male screw 6 made of the shape memory resin of the present invention.
[0060]
The male screw 6 also includes a head portion 61 and a screw portion 62 integral with the head portion 61, and a conical hole 622 is formed at the center of the screw portion 62. Then, when the male screw 6 is heated to the shape recovery temperature, as shown in FIG. 10, at the same time as the screw disappears, the shape recovers in the direction in which the outer diameter decreases, and the male screw having the reverse conical screw forming portion 62B without a screw. It becomes the base material 6B.
[0061]
Next, a procedure for forming the male screw 6 configured as described above will be described.
[0062]
In FIG. 10, the male screw base material 6B includes a head portion 61B and an inverted conical screw forming portion 62B having no screw, and the screw forming portion 62B has a hole 622B formed at the center thereof.
[0063]
Here, the outer diameter d0 of the thread forming portion 62B of the male screw base material 6B is set to be smaller than the diameter d1 of the thread root of the male screw 6.
[0064]
The hole 622B formed at the center of the thread forming portion 62B may be post-processed by a drill or the like, or may be formed at the same time when the male screw base material 6B is formed.
[0065]
When the male screw base material 6B is formed, the thread forming portion 62B of the male screw base material 6B is arranged in the lower die 11 having a hole 11a having an effective diameter of the male screw 6, and the upper die 12 holds the male screw base material 6B. (See FIG. 11A).
[0066]
At this time, the lower mold 11 and the upper mold 12 are heated by a heater or the like to the softening start temperature of the male screw base material 6B (for example, in the case of a shape memory resin diary manufactured by Mitsubishi Heavy Industries, a shape recovery temperature of −20 ° C.) to less than the shape recovery temperature. It is heated to a temperature and maintained in that state until the male screw base material 6B is softened.
[0067]
Then, as shown in FIG. 11B, a conical pin 16 having a taper angle substantially equal to the taper angle of the thread forming portion 62B is inserted through a processing hole 11b communicating with a hole 11a formed in the lower die 11. , Into the hole 622B formed in the center of the thread forming portion 62B of the male screw base material 6B. Therefore, the hole 622B of the thread forming portion 62B of the male screw base material 6B is pushed open, and the outer diameter of the screw forming portion 62B is enlarged to the diameter of the hole 11a of the lower die 11 (see FIG. 11C).
[0068]
Here, the maximum diameter of the pin 16 is set smaller than the diameter d1 of the thread root of the male screw 6.
[0069]
Thereafter, this state is maintained until the external thread base material 6B becomes lower than the softening temperature (see FIG. 11D).
[0070]
Note that cold air may be supplied to the lower mold 11 and the upper mold 12 to be rapidly cooled.
[0071]
When the male screw base material 6B reaches the softening temperature or lower, the mold is opened, the male screw base material 6B is taken out, and as shown in FIG. 11 (e), the male screw base material 6B is enlarged into an enlarged hole 622B. A jig 16 having the same shape as the shape of the hole 622B is attached, and a screw is rolled into the male screw forming portion 62B.
[0072]
At this time, the male screw base material 6B is heated to a temperature lower than the softening start temperature of the male screw base material 6B (for example, in the case of a shape memory resin diary manufactured by Mitsubishi Heavy Industries, -20 ° C.) to less than the shape recovery temperature. Thereafter, the screw is cooled to a softening temperature or lower while being rolled.
[0073]
When the male screw 6 thus formed is heated to the shape recovery temperature, the screw disappears and, at the same time, recovers its shape in the direction of decreasing the diameter. For this reason, the screw does not bite into the female screw 20 at the time of shape recovery, and can be easily separated from the female screw 20. Further, since the volume is smaller than that of a solid material, the material is easily heated, energy consumed for disassembly can be reduced, and material costs can be reduced.
[0074]
In the above-described embodiment, the male screw 6 has been described. However, the present invention is not limited to the male screw 6 but may be applied to a fastening member that uses a screw portion to fasten, for example, a bolt.
[0075]
【The invention's effect】
As described above, according to the present invention, the interference between the male screw and the female screw can be reliably prevented at the time of shape recovery, and the screw can be easily separated.
[Brief description of the drawings]
FIG. 1 is a sectional view showing a fastening state of a part to be fastened by a fastening member of the present invention.
2 is a cross-sectional view showing a state in which the shape of the fastening member has been recovered in the fastening state of the part to be fastened in FIG. 1;
FIG. 3 is an explanatory view showing a partially omitted shape recovery process of a male screw and a female screw constituting the fastening member of the present invention.
FIG. 4 is a cross-sectional view showing another fastening state of the part to be fastened by the fastening member of the present invention.
FIG. 5 is a cross-sectional view showing another fastening state of a part to be fastened by the fastening member of the present invention.
FIG. 6 is a sectional view showing an embodiment of the male screw of the present invention.
FIG. 7 is a cross-sectional view showing a shape recovery state of the male screw of FIG. 6;
FIG. 8 is a process chart for explaining a manufacturing process of the male screw of FIG. 6;
FIG. 9 is a sectional view showing another embodiment of the male screw of the present invention.
FIG. 10 is a cross-sectional view showing a shape recovery state of the male screw of FIG. 9;
FIG. 11 is a process diagram illustrating a manufacturing process of the male screw of FIG. 9;
FIG. 12 is a cross-sectional view showing a fastening state of a part to be fastened by a conventional external thread made of a shape memory material.
FIG. 13 is a cross-sectional view showing a state in which the shape of the male screw has recovered in the fastening state of the part to be fastened in FIG. 12;
FIG. 14 is a cross-sectional view showing a shape recovery state of a male screw made of a shape memory material in FIG. 12;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Fastening member 2, 6 Male screw 2A, 6A, 6B Male screw base material 21, 61, 61A, 61B Head 22, 62 Screw part 621, 622 Hole 22A, 62A, 62B Screw forming part 621A, 622B Hole 3 Female screw 3A Female screw mother Material 32 Screw part 32A Screw forming part 4 Electromagnetic wave absorbing material 5 Infrared absorbing material 11 Lower mold 11a Hole 12 Upper mold 13,16 Pin 14,17 Jig

Claims

In a fastening member for fastening by screwing a male screw and a female screw, the male screw and the female screw are made of a shape memory material having substantially the same shape recovery temperature and shape recovery direction, and the screw formation of the male screw base material at the time of shape recovery. The threaded portion of the threaded part and the threaded part of the internal thread base material are respectively a tubular shape and a holeless shape without a screw, and the outer diameter and the hole diameter of the threaded portion are substantially equal to the effective diameters of the male screw and the female screw, respectively. Element.

The fastening member according to claim 1, wherein the hole diameter of the thread forming portion of the female screw base material when the shape of the female screw is recovered is larger than the outer diameter of the screw forming portion when the shape of the external screw is recovered.

The fastening member according to claim 1, wherein the shape memory material is a shape memory alloy or a shape memory resin.

A product using a fastening member, wherein the fastening member according to any one of claims 1 to 3 is used in at least one place.

The product using the fastening member according to claim 4, wherein an electromagnetic wave absorbing material or an infrared absorbing material is provided near the fastening member.

An external thread made of a shape memory material consisting of a head and a thread, which has a space at the center of the thread, and when heated to the shape recovery temperature, the thread disappears and the thread has a smaller outer diameter at the same time A male screw that recovers shape in the direction.

This is a male screw made of shape memory material consisting of a head and a screw part.It has a space in the center of the screw part, and when heated to the shape recovery temperature, the screw disappears and at the same time, the screw part becomes a substantially inverted conical shape. A male screw that recovers its shape.

The method for manufacturing a male screw according to claim 6 or 7, wherein the screw forming portion of the male screw base material whose shape is memorized in the hole of the lower die having a diameter substantially equal to the effective diameter of the male screw is loosely fitted to the upper die. After holding, the male screw base material is heated, the outer diameter of the thread forming portion of the male screw base material is expanded to the diameter of the hole of the lower die, and then the screw is rolled into the screw forming portion. Manufacturing method of male screw.