JP3815864B2

JP3815864B2 - Female thread member

Info

Publication number: JP3815864B2
Application number: JP24186897A
Authority: JP
Inventors: 洋二中川; 直幸藤井; 圭史野村
Original assignee: 株式会社杉浦製作所
Priority date: 1997-08-21
Filing date: 1997-08-21
Publication date: 2006-08-30
Anticipated expiration: 2017-08-21
Also published as: JPH1162939A

Description

【０００１】
【発明の属する技術分野】
本発明は、ナット等の雌ねじ部材に関し、特に雄ねじ部材との螺合の際、塗膜やゴミ等の異物を剥離したり取り除いたりする機能と緩み止めの機能を有する雌ねじ部材に関する。
【０００２】
【従来の技術】
従来、ナット等の雌ねじ部材で塗膜等の付着したボルトを締め付けるには、塗膜等の厚みによりボルトの径が増大した分、やや強引に締め付けていた。また、実公平５−３９２１１号公報に記載のナットは、相手方と螺合する際に、その螺合方向の先端よりさらに先行して形成した凸部の進行方向の端部を、ねじ内周面に対しほぼ垂直に立ち上げたものである。このようなナットによれば、相手方との螺合時に、その螺合の進行に従って先頭に位置する上記凸部の垂直面が、例えばボルトのねじ山に付着している塗膜を剥離し、これを螺合の進行に従って排出することができる。
【０００３】
【発明が解決しようとする課題】
塗膜等の付着したボルトを通常のナットで締め付ける際には、その締め付け時に生ずる塗膜等の異物がナットのねじ山とボルトのねじ山との間に入り込み、その異物でナットの動きが阻害されたり、塗膜の厚み及び粘性などが締め付けの抵抗となる場合があった。また、上記公報のナットによると、異物がナットのねじ山とボルトのねじ山との間に入り込む問題は解消ないし抑制できるものの、上記凸部により剥離された塗膜等は、ナットの座面側に押し出されることになり、この押し出された塗膜等がナット締結時にナット座面と相手方部材の当接面との間に入り込む可能性があるため、ナット締結力に好ましくない影響を生じる場合も考えられる。
【０００４】
一方、上記のように締結力が不足したナットには次のような問題点がある。すなわち、上記ナットにおいては、雌ねじ部に先行して塗膜剥離用の凸部が形成されているため、雄ねじ部に螺合・締結された状態においてそのナット座面側には、ねじ孔内周面と雄ねじ部外周面との間に凸部の高さに対応する一定幅の隙間（雄ねじ部と雌ねじ部が噛み合わない非ねじ係合部分）が形成されることになる。その結果、全長にわたって雌ねじ部が形成される同寸法のナットに比べてねじ締結力が低下し、ねじ締結状態に緩みが生じやすくなるため、同程度の締結力を確保するためには、ナットの軸方向寸法を必然的に大きくせざるを得ないといった事情があった。
【０００５】
本発明の課題は、螺合対象となるボルト等の雄ねじ部材に付着した塗膜等の異物の除去機能を有して、しかも剥離した塗膜等の異物が自身の座面と雄ねじ部材の当接面との間に入り込むことを防止ないし抑制でき、ひいては異物の付着した雄ねじ部材への締め付けを容易に行うことができるとともに、異物除去機能の付加に伴い生ずるねじ緩みの問題も寸法を大きくすることなく良好に回避することのできる雌ねじ部材を提供することにある。
【０００６】
【課題を解決するための手段及び作用・効果】
このような課題を解決するために、本発明の雌ねじ部材の構成は下記の特徴を有する。すなわち、雌ねじ部材の雌ねじ孔に形成された雌ねじ部に、雄ねじ部材の雄ねじ部が螺合するとともに、前記雄ねじ部材に対する前記雌ねじ部材の螺合の開始側を入口側端部、逆側を出口側端部として、前記入口側端部の雌ねじ孔には、雄ねじ部に螺合する異物除去用凸部と雌ねじ孔のねじ谷径よりも深い、異物を収容する異物溜まり部とをそれぞれ複数個配置し、前記雄ねじ部に螺合する異物除去用凸部の螺合先行側の端面が、前記異物溜まり部に隣接して形成される異物除去部を構成し、前記異物除去部により前記雄ねじ部に付着した前記異物を除去して、その除去された異物を異物溜まり部に収容する。また、前記出口側端部の雌ねじ部には、その雌ねじ部のねじ山の頂部が間欠的に内方へ突出して内径を縮径するように周方向に繰り返して連続する波状の凹凸が形成され、それらの凹凸の凸部並びに凹部はその雌ねじ部の軸方向において互いに対応する部位に位置し、それらの凸部が雄ねじ部の谷部に喰い込むことにより、緩み止め用の縮径雌ねじ部を形成し、前記雌ねじ部材は、前記入口側端部の雌ねじ部に形成されて雌ねじ部の螺合長を減少させる前記異物溜まり部と、出口側端部の雌ねじ部の全周に配置した波状の凹凸による前記緩み止め用の縮径雌ねじ部とが、前記入口側端部及び出口側端部の分かれた位置に組み合わされ、前記螺合の入口側端部における螺合長の減少によるねじ締結力の低下を、螺合の出口側端部における緩み止め用の縮径雌ねじ部によって回避する。
【０００７】
上述の構成により、異物除去部で除去された異物を上記異物溜まり部に収容し、例えばナット等の雌ねじ部材の座面と相手方部材の当接面との間に異物が入り込むことを防止して、ナット締結力を強化することができる。また、異物除去部形成のために雌ねじ部材の雌ねじ部寸法が短くなり、ねじ締結力が低下しても、緩み止め用の縮径雌ねじ部が形成されているため、雌ねじ部材の軸方向寸法を大きくすることなくねじ締結状態の緩みを回避でき、従って、材料歩留まりを向上して、雌ねじ部材の重量化も免れることができる。
【０００８】
なお、本発明が対象とする雌ねじ部材としては、ボルト等の雄ねじ部材にねじ込まれるナットが代表的であるが、他部材に固定されたウェルドナットや、ナットの形態をとらないもの、例えば金型やフレーム等に形成された雌ねじ部等にもこの発明を適用することができる。
【０００９】
更に、雌ねじ部材の出口側端部の構成によれば、全周の一部について押圧力を加えて変形させた場合のような雌ねじ部の変形のばらつきが生じにくい。しかも、縮径雌ねじ部のねじ山には周方向に繰り返し連続する凹凸が形成され、雄ねじ部材のねじ部にはその凹凸の緩み止め凸部が全周にわたり均等に接触することとなるため、従来のねじ山の全周で圧接する場合に比べて摩擦が小さくて済み、焼付けが生じにくい。また、異物除去部形成のために雌ねじ部材の雌ねじ部寸法が短くなり、ねじ締結力が低下しても、緩み止め用の縮径雌ねじ部が形成されているため、雌ねじ部材の軸方向寸法を大きくすることなくねじ締結状態の緩みを回避でき、従って、材料歩留まりを向上して、雌ねじ部材の重量化も免れることができる。そして、連続的に繰り返す凹凸の緩み止め凸部により実質上全周にわたり均等に締付力が作用するため緩み止め効果も大きい。
【００１０】
ここで、縮径雌ねじ部のねじ山の緩み止め凸部が、雄ねじ部材の谷底ないしねじ山側面との間で互いに押付力を及ぼし合う際に、ねじ山の緩み止め凸部が弾性的に圧縮されるが、このとき緩み止め凸部の両側に凹部があるから緩み止め凸部の圧縮された肉部が両側に逃げ易く（言い換えれば圧縮力が両側の凹部に分散され易く）、これが螺合時のトルクの激増を抑えつつ、螺合完了後には複数の緩み止め凸部と谷底ないしねじ山側面との圧接状態で良好な緩み止め機能が果たされる。つまり、螺合時のトルク軽減と緩み止め機能の充実との両立を実現する。
【００１１】
【発明の実施の形態】
以下、図面に示すいくつかの実施例を参照しつつ、この発明の実施の形態を説明する。
（実施例１）
図１は、本発明の雌ねじ部材の第一の構成に係る一実施例として、塗膜剥離機能あるいはゴミ等の除去機能と緩み止め機能とを有するナット１を示している。また、図２はその座面２側から見たものである。このナット１はその中間部に形成された六角部３、螺合するボルトの入口側に形成された偏平なフランジ部４、ボルトの先端が内部に位置しあるいは突出する出口側端部５との一体構造をなしている。また、細頭円錐台形状（図１及び２）の外観を呈し、そこがテーパ外周面６となっており、フランジ部４の端面（入口側端部）が座面２となっている。ただしフランジ部４は必須というわけではなく、六角部３の端面が座面２となっていてもよい。
【００１２】
出口側端部５からフランジ部４を貫通する円筒状の空間において、その六角部３側に主雌ねじ部７が形成され、出口側端部５には主雌ねじ部７と同心に連続し、縮径されている縮径雌ねじ部８が形成されている。また、主雌ねじ部７より座面２側の円筒内周面には１又は複数個の異物除去用凸部９が形成されている。この異物除去用凸部９の螺合方向の進行側の端面が、その円筒内周面からほぼ垂直に立ち上がる異物除去部（この例では塗膜剥離面１０）となっている。異物除去用凸部９は、この例のように円周方向の３箇所に等角度間隔に、かつ軸方向に３条（３個）設けてもよいし、それを２個もしくは１個にしてもよい。
【００１３】
図２及び図３に示すように、上記のような周方向の３箇所に形成された異物除去用凸部９の間の部分に、３箇所の異物溜まり部１１が、例えば１２０°の等角度間隔で形成され、この異物溜まり部１１は凹陥部の形状となっており、塗膜溜まり部を構成している。以下この異物溜まり部１１を塗膜溜まり部１１もしくは凹陥部１１ともいう。この部分は、前記塗膜剥離面１０で剥離した塗膜を主に収容する部分であるが、ゴミ等の異物も併せて収容できることは言うまでもない。塗膜溜まり部１１（凹陥部）は、図１（ｂ）に示すように、主雌ねじ部７の下孔１２の径より一定量深く形成されていて、これが座面２まで達してその面に開放している。なお、図４に示すように、この塗膜溜まり部１１を座面２までは達しないように閉じた形態で形成してもよい。
【００１４】
そして、図５に示すように、ボルト等の雄ねじ部材１３の雄ねじ部１４と、当該ナット１とが螺合する際には、主雌ねじ部７に先立って異物除去用凸部９が雄ねじ部材１３の雄ねじ部１４と螺合し、その異物除去用凸部９の塗膜剥離面１０が雄ねじ部１４に付着した塗膜等を剥離し、これを塗膜溜まり部１１に収容する。図６は、雄ねじ部材１３にナット１を螺合する際に、その雄ねじ部材１３の雄ねじ部１４に付着した塗膜Ｐを剥離し、その剥離された塗膜Ｐ’がナット１の座面２側の塗膜溜まり部１１に収容された様子を示している。符号１５は、相手方の当接面である。
【００１５】
なお、図７に示すナット１６のように、六角部３とフランジ部４が連続したやや軸方向に長い寸法を有し、その座面２側に、前述のねじ下孔１２の径より大きな（深い）円筒状ガイド部１７を形成して、これが塗膜溜まりの一部又は全部を構成するようにしてもよい。ここで、前述の異物除去用凸部９の間の周方向領域は、前述のように塗膜溜まり部１１となっている。なお、この異物除去用凸部９の間の周面を例えばねじ下孔１２と一致する円筒面の一部で形成すれば、この塗膜溜まり部１１の部分は塗膜溜まりとしての機能は低く、円筒状ガイド部１７が実質的に塗膜溜まりとして機能することとなる。また円筒状ガイド部１７は、雄ねじ部材と螺合する際にそれをガイドするガイド部の役割も果たす。
【００１６】
一方、図８に示すナット１８のように、図７の円筒状のガイド部１７にさらに第２の凹陥部１９を形成して、この第２の凹陥部１９が円筒状ガイド部１７、塗膜溜まり部１１（第１の凹陥部１１）とともに塗膜溜まりとして機能するように構成してもよい。この第２の凹陥部１９は、座面２までは達しないように、かつ周方向に円環状の溝形態で形成することができる。ただし図９に示すように、第２の凹陥部１９を周方向に断続的に、例えば１２０°の等角度間隔に３個形成することもできる。
【００１７】
図１に戻り、縮径雌ねじ部８は、その雌ねじ内径が主雌ねじ部７の内径より小さくなるように全周にわたり均等に縮径され、円形状断面を有するものである。また、主雌ねじ部７のねじ山（又は谷）を結ぶ仮想線はねじ軸に平行な直線となるが、縮径雌ねじ部８のねじ山の先端又は谷径を結ぶ仮想線は、出口側端部５の先端側ほどねじ軸に近づくわずかな傾きを持った直線あるいは曲線となり、先端ほど縮径の程度が大きくなっている。なお、本件の該当図面においては、理解を容易にするために縮径の程度を実際より誇張して描いている場合があり、必ずしも実施品の形態そのものを表すものではない。
【００１８】
また、縮径雌ねじ部８は、３条弱のねじ山からなり、その部分のねじ山には、図１０に示すように、その周方向に繰り返し連続する波状の凹凸２０が形成されている。波状の凹凸２０は、これらのねじ山にわたって連続的に形成され、隣接するねじ山同士間でその凹凸２０の凸部２２（以下、緩み止め凸部ともいう）並びに凹部２４が、それぞれそれらのねじ山を横断する直線上（ねじ軸を含む垂直面）の互いに対応する位置に形成されている。また、凹凸２０は縮径雌ねじ部８の１周で例えば１２箇所形成されている。
【００１９】
この実施例では、凹凸２０の始点は出口側端部５の先端面であり、終点は縮径雌ねじ部８と主雌ねじ部７との境界部近傍の上記先端面と平行な面（ねじ軸に直角な面）であり、これに対しねじ山は螺旋を描くため、凹凸２０の始点近傍及び終点近傍では、凹凸２０がねじ山を厚さ方向に完全に分断した形態とはならず、その意味で縮径雌ねじ部８の３条弱のねじ山に対し、凹凸２０が完全な形で形成されているのは２条弱のねじ山で、凸部２２の数は、６〜２０個の範囲に定めるとよい。この範囲が上記の焼付け防止及び締付トルクを減少させる効果と、緩み止め効果のバランスを保つのに好適である。
【００２０】
前記縮径雌ねじ部８のねじ山の頂部を周方向に連続して構成する波状の凹凸２０の具体的な形状は、例えば円弧状に波打つ形態や、平面視で緩み止め凸部がその先端側から基端側に幅広となる三角形又は台形状、凹部がその反対の逆三角形状又は逆台形状等とすることができる。いずれの形状でも、凹凸２０の緩み止め凸部２２は縮径雌ねじ部８の中心側に突出し、凹部２４は縮径雌ねじ部８の中心側から後退する形態で形成されている。緩み止め凸部２２の先端は上述の縮径雌ねじ部８のねじ山先端に、凹部２４の底は縮径雌ねじ部８の谷底にほぼ一致している。縮径雌ねじ部８の縮径により凹凸２０も縮径されており、その結果、周方向に連続的に繰り返す複数の緩み止め凸部２２の先端をつなぐ内接円２６の直径ｄ1は、螺合されるボルトの谷径より小さくされている。他方、複数の凹部２０の底をつなぐ内接円は、ボルトの谷径より大きいか等しい程度となっている。その緩み止め凸部２２の先端部がその基端部より断面積が小さいため弾性変形し易く、従って締付トルクを小さくすることができる。なお、前述のように波状の凹凸２０として円弧状に波打つ形態とすれば、その凸部２２と雄ねじ部材のねじ部との接触面積が小さくなり焼付け防止効果が大きくなるとともに、型寿命も向上する。他方、台形状とすれば緩み止め効果を大きくすることができる。
【００２１】
また、緩み止め効果と締付けトルク及び型寿命のバランスを考慮した縮径雌ねじ部８に設ける凹凸２０の（言い換えれば緩み止め凸部２２の）好適な数は、縮径雌ねじ部８の平均内径ｄや縮径雌ねじ部８のねじ山ピッチｐあるいは焼入れの有無や程度等によって相違するので、一概には言えないが、例えば図１１（ａ）に示す縮径雌ねじ部８の平均内径ｄを基準した場合、凹凸２０のピッチｓが０．１〜０．５ｄの範囲になるように凹凸２０の大きさや数を定めることが望ましい。
【００２２】
図１２に、このような構造のナット１と雄ねじ部材１３を螺合したときの作用を示す。（ａ）に示すように、ナット１をその異物除去用凸部９から主雌ねじ部７へと雄ねじ部材１３の雄ねじ部１４に螺合してゆくと（雄ねじ部材１３をナット１に螺合する場合も同じ）、その雄ねじ部材１３とナット１の螺合の後半ないしは終端近傍において、（ｂ）に示すように、雄ねじ部材１３の先端部が縮径雌ねじ部８に達する。
【００２３】
その後は、縮径雌ねじ部８にある多数の緩み止め凸部２２の内接円２６の直径ｄ1（図１０（ａ））が、雄ねじ部材１３の谷径より小さいため、ナット１と雄ねじ部材１３の螺合の進行に伴い、ナット１の縮径雌ねじ部８の複数の緩み止め凸部２２は、図１３のように、雄ねじ部１４の谷底２７に周方向の多数の位置で当接し、これら緩み止め凸部２２と谷底２７は互いに押圧力を及ぼし合う。そのため、緩み止め凸部２２は弾性的に圧縮されるが、緩み止め凸部２２の両端に凹部２４があるため、概念的に言えば、緩み止め凸部２２の圧縮された肉部は両側に逃げやすい。つまり緩み止め凸部２２に直径方向外側に作用する圧縮力が両側の凹部２４へ分散しやすく、従って、凹凸２０がない場合と比べ螺合時のトルクの過度の増大が抑えられ、更に螺合完了後には複数の緩み止め凸部２２と谷底２７との圧接状態で良好な緩み止め機能が果たされる。図１２（ｃ）は、このような状態を示す。
【００２４】
なお、ナット１の縮径雌ねじ部８と雄ねじ部１４が、上述の締め付け凸部２２と谷底２７との間で押圧力を及ぼし合いながら螺合することに伴い、縮径雌ねじ部８の内径は弾性的にある程度拡径された状態となるのが普通である。その場合は、縮径雌ねじ部８の内径テーパ角は図１２のα2からα3へ所定量小さくなる場合がある。この状態で、縮径雌ねじ部８には周方向の引張力が作用し、この引張力が多数の締め付け凸部２２を介して雄ねじ部１４の谷底２７の押圧力となって作用することで、締付トルクの過度の増大や焼付けを招くことなく、充分な緩み止め効果が発揮される。
【００２５】
なお、緩み止め用の縮径雌ねじ部としては、例えば特開昭５５−３０５９３、特公平３−３１９２６に開示されている公知の構成、すなわちナットの出口側端部を外側から複数箇所でかしめて、雌ねじの内周に複数の（例えば３個の）緩み止め用の凸部（縮径雌ねじ部）を形成した構成も本発明においては採用可能である。図３０は、雌ねじ山を内方へ突出させて形成した３個の凸部１０２を有する緩み止めナット１０１を示すものである。しかしながらこの構成の場合、ナットの複数箇所を局部的にかしめて形成される凸部１０２は、その位置や寸法精度にばらつきが生じる場合がある。また、局部的に突出した凸部とボルトの雄ねじ部が圧接して摩擦が過度に大きくなり、締め込みに極めて大きなトルクを必要としたり、パワーレンチ等で締め込む際に、焼付けを生じたりすることもある。そこで、上記図１２等に示す構造とすれば、寸法精度も高く、締め付け時の焼付け等も起こりにくいのでより望ましいといえる。
【００２６】
次に、上記ナット１の雌ねじ部材の雌ねじ部及び縮径雌ねじ部の製造方法について説明する。例えば、図２６（ａ）に示すように、まずナット素材を鍛造型にセットし公知の鍛造操作を行い、その外面を形成するとともに、内部に、主雌ねじ部７を形成するための主なる雌ねじ下孔７０と、凹凸２０（図１０（ｂ））を形成した出口側雌ねじ下孔７２を同時に形成する。このとき、凹凸２０の締め付け凸部２２の先端の位置は、後に加工される雌ねじの山の頂すなわち主なる雌ねじ下孔７０の内面にほぼ一致させ、凹部の底の位置は後に加工される雌ねじの谷底にほぼ等しくなるようにする。
【００２７】
次に、この中間品Ｎ1の主なる雌ねじ下孔７０と出口側雌ねじ下孔７２の両方に連続してタップ等の公知の方法で、雌ねじ７４を切る。これにより、出口側端部５のねじ切り部には、ねじ山と重なった凹凸２０（図１０（ｂ））が全周に形成される。
【００２８】
さらに、ねじ切り後の中間品Ｎ2を、例えば図２７（ａ）に示すように、プレス型８２でプレスすることにより、出口側端部５を縮径する。ここで、縮径前のナット１の出口側端部５のテーパ外周面６’のテーパ角θ1は、（ｂ）に示す縮径後のナット１のテーパ角θ2に比べ小さく形成されており、このテーパ角θ2に対応して形成されたプレス面８３で中間品Ｎ2のテーパ外周面６’をかしめることにより、図２７（ｂ）に示すように最終製品としてのナット１のテーパ外周面６はテーパ角θ2に塑性変形させられる。その結果、出口側端部５が内側に縮径される。
【００２９】
なお、ナット１の別の製造方法として、図２６（ｂ）に示すように、凹凸２０（図１０（ｂ））を形成した出口側雌ねじ下孔７２を鍛造によって先に形成し、次に主なる雌ねじ下孔７０をプレスで抜いて、ねじ切り、縮径の工程を経る方法も可能である。また、（ｃ）に示すように、鍛造による主なる雌ねじ下孔７０を軸方向に貫通して形成した後、プレスによって凹凸２０を有する出口側雌ねじ下孔７２を形成し、その後、それらねじ下孔７０、７２にわたるねじ切り、縮径の順に工程を組むことも可能である。
【００３０】
なお、縮径雌ねじ部８の凹凸形状として、図２８（ａ）に示すような台形状の凹凸９２（厳密に言えば台形状凸部の先端面は円弧凹状の面となり、１周分の断続的な個々のねじ山面積ｓ１の総和が１周分がすべて連続するねじ山で構成されている場合の例えば１／３〜１／４以下）、（ｂ）に示すような三角形状の凹凸９４とすることもできる。
【００３１】
また、本発明はナットに限るものではなく、雌ねじ構造をとる部材に広く適用され得る。例えば、図２９（ａ）に示すように、フレーム部材９５上に複数形成された凸状の緩み止め機能を有する雌ねじ部９６の出口側端部を縮径し、かつ、その内周の雌ねじのねじ山に凹凸を設け、上記ナット１と同様の効果を得ることができる。また、図２９（ｂ）に示すように、パイプ状の雌ねじ部材９７についても同様に適用できる。図のＡ部分が前述の雌ねじ部１４及び縮径雌ねじ部８の構造に相当する。
【００３２】
（実施例２）
図１４（ａ）及び（ｂ）は、本発明の雌ねじ部材の第二の構成に係る一実施例としての、塗膜剥離機能あるいはゴミ等の除去機能と緩み止め機能とを有するナット１５０を示している。なお、実施例１のナット１と共通の部分には、同一の符号を付して説明を省略する。該ナット１５０においては、塗膜剥離面１０の縁１０ａは、雄ねじ部に付着した塗膜層を削り取るエッジあるいは刃部として機能する。また、図１５に示すように、これら異物除去用凸部９の内、１条目（座面２側）には、螺旋の中心軸線Ｏと直交する面内において該中心軸線Ｏから自身の内縁９ｂまでの距離Ｒが、螺旋の先行端（塗膜剥離面１０）から該螺旋の末端に向けて連続的に大きくなるように逃げ部３０が形成されている。
【００３３】
上記のように凸部９の１条目においては、逃げ部３０が形成されているため、図１６に示すように、雄ねじ部材１３の雄ねじ部１４に付着した塗膜Ｐ等と接触するのは異物除去用凸部９の先行端付近のみとなっており、異物除去用凸部９と塗膜Ｐ等との接触部分が少なくなっている。これにより、異物除去用凸部９が塗膜Ｐ等の摩擦抵抗を抑えながら螺進できる。
【００３４】
次に、図１７に示すように逃げ部３０は、螺旋の中心軸線Ｏからその内縁９ｂまでの距離Ｒが、該中心軸線Ｏを中心とする単位回転角度λ当りでほぼ一定の割合ΔＲで連続的に大きくなるように形成されている。この場合、螺合先行端１０ｂでは上記距離ＲはＲ0であるが、そこから螺旋に沿って単位回転角度λだけ移動するとＲ＝Ｒ1＝Ｒ0＋ΔＲ、２λでＲ＝Ｒ2＝Ｒ0＋２ΔＲ、３λでＲ＝Ｒ3＝Ｒ0＋３ΔＲとなる。なお、図１８に示すように逃げ部３０は、上記距離Ｒが、中心軸線Ｏを中心に所定の回転角度λ1までは所定の割合で連続的に大きくなり、それ以降の角度区間では一定の距離Ｒ1となるように形成してもよい。なお、図１８（ａ）は、回転角度λ1までの区間で内縁９ｂが円弧状あるいはその他の曲線状に形成された例を、また、図１８（ｂ）は、同様に直線状に形成された例をそれぞれ示している。
【００３５】
なお、上記実施例では塗膜剥離面１０は内周面の接線方向とほぼ垂直に立ち上がって形成されているが、塗膜剥離面１０と内周面の接線方向との角度を、塗膜等の剥離に支障がない程度の範囲で鈍角又は鋭角に形成することも可能である。
【００３６】
また、図１７（ｂ）に示すように、螺合先行端１０ｂにおいて異物除去用凸部９の内縁９ｂ（あるいは螺合先行端１０ｂにおけるその接平面Ｐ）と塗膜剥離面１０とのなす角度φを鋭角とすれば、塗膜等の異物に対する切削効果を高めることができる。この場合、該角度φは、望ましくは７０〜８０゜の範囲で調整するのがよい。角度φが小さすぎると螺合先行端１０ｂを型鍛造法で製造する場合、型寿命が短くなる場合がある。
【００３７】
なお、上記実施例では、３個の異物除去用凸部９の１条目に逃げ部３０を形成したが、２条目あるいは３条目の異物除去用凸部９にも該逃げ部３０を形成することができる。
【００３８】
（実施例３）
図１９及び図２０は、本発明の雌ねじ部材の第三の構成に係る一実施例としての、塗膜剥離機能あるいはゴミ等の除去機能と緩み止め機能とを有するナット２００を示している。なお、実施例１のナット１と共通の部分には、同一の符号を付して説明を省略する。該ナット２００においては、六角部３側に形成された主雌ねじ部７の螺合方向における先行端側に隣接し、かつ、円周方向の３箇所にほぼ等角度間隔で、異物を除去するための異物除去用凸部９としての異物除去雌ねじ部４０が形成されている。このそれぞれの異物除去雌ねじ部４０には、図２１（ａ）に示すように、軸方向に並んで３条（３個）のねじ山セグメント４１、４２、４３が形成されており、このねじ山セグメント４１、４２、４３の高さは、主雌ねじ部７側から座面２側へ向かうほど段階的に減少している。図２１（ｂ）は、３箇所に形成された異物除去雌ねじ部４０のねじ山セグメント４１〜４３を、直線状に表し、横軸に異物除去雌ねじ部４０の長さ、縦軸にねじ下孔からの高さを示したものである。なお、３条目のねじ山セグメント４３は、主雌ねじ部７とほぼ同じ高さとなっている。
【００３９】
そして、図２２に示すように、ボルト等の雄ねじ部材１３の雄ねじ部１４と、ナット１とが螺合する際には、主雌ねじ部７に先立って、異物除去雌ねじ部４０が雄ねじ部材１３の雄ねじ部１４と螺合する。この時、雄ねじ部１４に付着した塗膜等を除去するには、図２３に示すように、雄ねじ部材１３が螺合方向に螺進して行くと、第一段階として、異物除去雌ねじ部４０に形成されたねじ山セグメント４１の塗膜剥離面１０によって塗膜Ｐ1等のうち所定量を除去し、第二段階で第一段階の除去過程で残った塗膜Ｐ2等をねじ山セグメント４２の塗膜剥離面１０でさらに部分的に除去する。そして、第三段階では、３条目のねじ山セグメント４３で塗膜除去がなされるが、該ねじ山セグメント４３が主雌ねじ部７とほぼ同じ高さとなっていることから、残留している塗膜Ｐ3等のほぼ全てをその塗膜剥離面１０で除去することができる。このように除去された塗膜等は図６と同様に塗膜溜まり部１１に収容される。
【００４０】
なお、図２４（ａ）に示すように、全てのねじ山セグメントの高さを互いに異なるものとすることもできる。同図では、３箇所に形成された異物除去雌ねじ部４０の合計９個のねじ山セグメント４４〜５２を、座面側から９段階に高くなるように形成した例を示している。なお、図２４（ｂ）は、ねじ山セグメント４４〜５２について、各異物除去雌ねじ部４０の長さ（横軸）と高さ（縦軸）との関係を示したものである。このように、ねじ山セグメント４４〜５２間での高さ変化量をさらに細分化することにより、塗膜等の除去に伴う抵抗をさらに少なくすることができ、ひいてはよりスムーズなねじの締め付けができる。なお、本実施例においては、異物溜り部１１で区切られる異物除去雌ねじ部４０の各部分が、ねじ山セグメントを３条ずつ含む場合について説明したが、ねじ山セグメントの条数はこれに限定されるものではない。なお、異物除去雌ねじ部４０に異物溜まり部１１を形成しない場合には、図２４（ｃ）に示すように、雌ねじ山の高さを連続的に変化させることもできる。
【００４１】
また、図２５に示すように、異物除去雌ねじ部４０を主雌ねじ部７側へ向かって縮径するテーパ状に形成することもできる。該異物除去雌ねじ部４０においては、具体的にはテーパ状の下孔Ｔにほぼ同じ高さで各ねじ山セグメント６０〜６２が形成されている。これにより、主雌ねじ部７のねじ下孔１２に対する上記ねじ山セグメント６０〜６２の突出量が、主雌ねじ部７側から座面２側へ向かうほど小さくなっている。なお、図２５では説明の便宜上、テーパの傾きをやや誇張して描いている。
【図面の簡単な説明】
【図１】本発明の実施例１のナットの正面図及びその断面図。
【図２】そのナットの座面側からの斜視図
【図３】そのナットの底面を示す図。
【図４】図１の変形例の断面図。
【図５】雄ねじ部材とナットとの螺合状態を示す部分断面図。
【図６】螺合時の作用説明図。
【図７】ナットの座面側にガイド部が形成された場合の説明図。
【図８】さらに別のガイド部が形成された場合の説明図。
【図９】第２の凹陥部を周方向に断続的に形成した場合の底面図。
【図１０】図１のＣ−Ｃ断面図及び平面図。
【図１１】縮径雌ねじ部の内径、凹凸のピッチ、ねじ山ピッチを示す図。
【図１２】雄ねじ部材と螺合した際の出口側端部の弾性変形による緩み止めの作用説明図。
【図１３】縮径雌ねじ部の凹凸の作用説明図。
【図１４】本発明の実施例２のナットの斜視図及びその部分拡大図。
【図１５】そのナットの底面を示す図。
【図１６】そのナットと雄ねじ部材との螺合状態を示す平面断面図。
【図１７】そのナットの異物除去用凸部の先行端付近を示す図。
【図１８】図１８の変形例を示す図。
【図１９】実施例３のナットの斜視図。
【図２０】そのナットの断面及び底面を示す図。
【図２１】異物除去雌ねじ部の断面を示す図。
【図２２】そのナットと雄ねじ部材との螺合状態を示す部分断面図。
【図２３】そのナットの螺合時の作用説明図。
【図２４】異物除去雌ねじ部の変形例を示す図。
【図２５】異物除去雌ねじ部をテーパ状に形成した場合を示す図。
【図２６】本発明のナットの雌ねじ部及び縮径雌ねじ部の製造方法を説明する図。
【図２７】その縮径工程を説明する図。
【図２８】縮径雌ねじ部の別の凹凸形状を示す図。
【図２９】本発明のナットのさらに別の実施例を示す図。
【図３０】縮径雌ねじ部の変形例を示す図。
【符号の説明】
１，１６，１８，１５０，２００ナット（雌ねじ部材）
２座面
３六角部
５出口側端部
７主雌ねじ部
８縮径雌ねじ部
９異物除去用凸部
１０塗膜剥離面（異物除去部）
１１異物溜まり部（凹陥部、塗膜溜まり部）
１７円筒状ガイド部
１９第２の凹陥部
２０，９２，９４凹凸
２２緩み止め凸部
２４凹部
３０逃げ部
４０異物除去雌ねじ部
４１〜５２ねじ山セグメント[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to a female screw member such as a nut, and more particularly to a female screw member having a function of peeling or removing foreign matter such as a coating film and dust and a function of preventing loosening when screwed with a male screw member.
[0002]
[Prior art]
  Conventionally, in order to tighten a bolt to which a coating film or the like is attached with a female screw member such as a nut, the bolt has been slightly forcibly tightened due to the increase in the diameter of the bolt due to the thickness of the coating film or the like. In addition, when the nut described in Japanese Utility Model Publication No. 5-39211 is screwed to the other party, the end portion in the traveling direction of the convex portion formed further ahead of the tip end in the screwing direction is formed on the screw inner peripheral surface. It was launched almost vertically. According to such a nut, at the time of screwing with the counterpart, the vertical surface of the convex portion positioned at the head as the screwing progresses peels off the coating film adhering to the thread of the bolt, for example. Can be discharged as the screwing progresses.
[0003]
[Problems to be solved by the invention]
  When tightening bolts with paint film attached with normal nuts, foreign matter such as paint film that occurs during tightening enters between the screw thread of the nut and the screw thread of the bolt, and the movement of the nut is obstructed by the foreign object. In some cases, the thickness and viscosity of the coating film become resistance to tightening. Moreover, according to the nut of the above publication, the problem that foreign matter enters between the screw thread of the nut and the screw thread of the bolt can be solved or suppressed, but the coating film peeled off by the convex part is Since the extruded coating film may enter between the nut seat surface and the abutting surface of the mating member when the nut is tightened, there may be an undesirable effect on the nut fastening force. Conceivable.
[0004]
  on the other hand,For nuts with insufficient fastening force as aboveThe following problemsButis there. That is, in the nut, since the convex portion for coating film peeling is formed prior to the female screw portion, the inner surface of the screw hole is formed on the nut seat surface side in a state of being screwed and fastened to the male screw portion. A gap having a certain width corresponding to the height of the convex portion (a non-screw engaging portion where the male screw portion and the female screw portion do not mesh with each other) is formed between the surface and the outer peripheral surface of the male screw portion. As a result, the screw fastening force is lower than that of a nut of the same size in which the female thread part is formed over the entire length, and the screw fastening state is likely to be loosened. Therefore, in order to ensure the same level of fastening force, Necessary to increase the axial dimensionTheThere were circumstances such as not getting.
[0005]
  An object of the present invention is to have a function of removing foreign matter such as a coating film adhering to a male screw member such as a bolt to be screwed. It is possible to prevent or suppress entry into the contact surface, and thus it is possible to easily tighten the male screw member to which foreign matter has adhered, and to increase the size of the screw loosening problem caused by the addition of the foreign matter removing function. It is an object of the present invention to provide a female screw member that can be favorably avoided without any problems.
[0006]
[Means for solving the problems and actions / effects]
  In order to solve such a problem, the female screw member of the present inventionStructureSei has the following characteristics. Ie,Female thread memberFormed in the female screw holeFemale threadIn addition,While the male screw part of the male screw member is screwed togetherIn the female screw hole of the inlet side end, the start side of the screwing of the female screw member to the male screw member is the inlet side end, and the opposite side is the outlet side end.Male threadInConvex part for removing foreign matter to be screwedA plurality of foreign substance reservoir portions that contain foreign matters and are deeper than the thread valley diameter of the female screw hole, and an end surface of the foreign matter removing convex portion that is screwed into the male screw portion is on the front side of the foreign matter reservoir. Adjacent to the departmentFormedRuForeign matter removal partConfigured and saidBy foreign matter removal partSaidAdhered to the male threadSaidRemove foreign matter and remove the foreign matterDifferentStorage partHoused inTo do. Also,SaidExit endThe female thread part of theFemale threadThe top of the screw thread protrudes inward intermittentlyInner diameterTheShrinkIn this way, wavy irregularities that are continuously repeated in the circumferential direction are formed, and the convex portions and concave portions of the concave and convex portions are located at portions corresponding to each other in the axial direction of the female screw portion, and these convex portions are valley portions of the male screw portion. Bite intoForming a reduced-diameter female thread to prevent looseningThe female screw member is formed on the female screw portion at the inlet side end portion to reduce the screwing length of the female screw portion, and the wavy unevenness disposed on the entire circumference of the female screw portion at the outlet side end portion. And the reduced-diameter female thread portion for preventing loosening are combined at separate positions on the inlet side end portion and the outlet side end portion, and the screw fastening force is reduced by reducing the screwing length at the inlet side end portion of the screwing. Reduction is avoided by the reduced-diameter female thread part for preventing loosening at the end of the screw exit.To do.
[0007]
  With the above configuration, the foreign matter removed by the foreign matter removing portion is accommodated in the foreign matter reservoir portion, and for example, foreign matter is prevented from entering between the seat surface of the female screw member such as a nut and the contact surface of the counterpart member. The nut fastening force can be strengthened. In addition, the size of the female screw member of the female screw member is shortened to form the foreign matter removing portion, and even if the screw fastening force is reduced, the reduced-diameter female screw portion for preventing loosening is formed. The loosening of the screw fastening state can be avoided without increasing the size, so that the material yield can be improved and the weight of the female screw member can be avoided.
[0008]
  The female screw member targeted by the present invention is typically a nut screwed into a male screw member such as a bolt, but a weld nut fixed to another member, or a nut not taking the form of a nut, for example, a mold The present invention can also be applied to a female screw portion formed on a frame or the like.
[0009]
  Furthermore, the outlet side end of the female screw memberAccording to the configuration,allVariations in the deformation of the internal thread portion are unlikely to occur as when a part of the circumference is deformed by applying a pressing force. In addition, the thread of the reduced diameter female thread part has irregularities that are continuously repeated in the circumferential direction, and the threaded part of the male screw member is uniformly contacted with the convex part of the irregularities on the entire circumference. Compared with the case where pressure welding is performed all around the thread, the friction is small, and seizure hardly occurs. In addition, the size of the female screw member of the female screw member is shortened to form the foreign matter removing portion, and even if the screw fastening force is reduced, the reduced-diameter female screw portion for preventing loosening is formed. The loosening of the screw fastening state can be avoided without increasing the size, so that the material yield can be improved and the weight of the female screw member can be avoided. Further, since the tightening force acts substantially uniformly over the entire circumference by the uneven protrusions of the unevenness that are continuously repeated, the effect of preventing looseness is also great.
[0010]
  Here, when the protrusions for preventing loosening of the thread of the reduced diameter female thread part exert a pressing force on the bottom of the male screw member or the side surface of the thread, the protrusions for preventing looseness of the thread are elastically compressed. However, at this time, since there are recesses on both sides of the loosening projection, the compressed meat part of the loosening projection easily escapes on both sides (in other words, the compression force is easily dispersed in the depressions on both sides), and this is screwed While suppressing the rapid increase in torque, a good anti-loosening function is achieved in the pressure contact state between the plurality of anti-loosening projections and the valley bottom or the screw thread side surface after screwing is completed. That is, it is possible to achieve both a reduction in torque at the time of screwing and enhancement of a locking function.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
  Hereinafter, embodiments of the present invention will be described with reference to some examples shown in the drawings.
(Example 1)
  FIG. 1 shows a nut 1 having a coating film peeling function or a dust removing function and a loosening preventing function as an embodiment of the first configuration of the female screw member of the present invention. FIG. 2 is a view from the seating surface 2 side. The nut 1 includes a hexagonal portion 3 formed at an intermediate portion thereof, a flat flange portion 4 formed at an inlet side of a bolt to be screwed, and an outlet side end portion 5 at which the tip of the bolt is located or protrudes. It has an integral structure. Further, it has an appearance of a fine truncated cone shape (FIGS. 1 and 2), which is a tapered outer peripheral surface 6, and an end surface (entrance side end portion) of the flange portion 4 is a seat surface 2. However, the flange portion 4 is not essential, and the end surface of the hexagonal portion 3 may be the seat surface 2.
[0012]
  In the cylindrical space penetrating the flange portion 4 from the outlet side end portion 5, a main female screw portion 7 is formed on the hexagonal portion 3 side, and the outlet side end portion 5 is concentrically continuous with the main female screw portion 7. A reduced diameter female thread portion 8 is formed. Further, one or a plurality of foreign matter removing convex portions 9 are formed on the inner peripheral surface of the cylinder on the seating surface 2 side from the main female screw portion 7. The end face on the traveling side in the screwing direction of the convex part 9 for removing foreign substances is a foreign substance removing part (in this example, the coating film peeling surface 10) rising almost vertically from the inner circumferential surface of the cylinder. As shown in this example, the protrusions 9 for removing foreign substances may be provided at three positions in the circumferential direction at equal angular intervals and three strips (three) in the axial direction, or two or one. Also good.
[0013]
  As shown in FIGS. 2 and 3, there are three foreign matters in the portion between the foreign matter removing convex portions 9 formed in the three circumferential directions as described above.ReservoirThe ball portions 11 are formed at regular angular intervals of 120 °, for example, and this foreign matterReservoirThe margin part 11 has the shape of a concave part and constitutes a coating film reservoir part. Hereinafter, the foreign material reservoir 11 is also referred to as a coating film reservoir 11 or a recess 11. Although this part is a part which mainly accommodates the coating film peeled by the said coating film peeling surface 10, it cannot be overemphasized that foreign materials, such as garbage, can also be accommodated. As shown in FIG. 1 (b), the coating film reservoir 11 (concave portion) is formed a certain amount deeper than the diameter of the lower hole 12 of the main female screw portion 7, and reaches the seating surface 2 on the surface thereof. It is open. As shown in FIG. 4, the coating film reservoir 11 may be formed in a closed form so as not to reach the seat surface 2.
[0014]
  Then, as shown in FIG. 5, when the male threaded portion 14 of the male threaded member 13 such as a bolt and the nut 1 are screwed together, the foreign matter removing convex part 9 is arranged on the male threaded member 13 prior to the main female threaded part 7. The coating film peeling surface 10 of the foreign matter removing convex portion 9 peels off the coating film and the like attached to the male screw portion 14 and accommodates it in the coating film reservoir portion 11. FIG. 6 shows that when the nut 1 is screwed onto the male screw member 13, the coating film P adhering to the male screw portion 14 of the male screw member 13 is peeled off, and the peeled coating film P ′ is the seating surface 2 of the nut 1. The mode that it was accommodated in the coating film pool part 11 of the side is shown. Reference numeral 15 denotes a contact surface of the other party.
[0015]
  In addition, like the nut 16 shown in FIG. 7, the hexagonal part 3 and the flange part 4 are continuous and have a slightly longer dimension in the axial direction, and the seating surface 2 side is larger than the diameter of the above-described screw hole 12 ( A deep) cylindrical guide portion 17 is formed, which is the coating film reservoir.RinoYou may make it comprise a part or all. Here, the circumferential region between the above-mentioned foreign matter removing convex portions 9 is the same as that described above.likePaint poolPart 1It is 1. If the peripheral surface between the foreign matter removing convex portions 9 is formed by a part of a cylindrical surface coinciding with the screw under hole 12, for example,Of the coating film reservoir 11The part is a coating poolRitoThe function is low, and the cylindrical guide portion 17 is substantially free of coating film.RitoWill function. The cylindrical guide portion 17 also serves as a guide portion that guides the male screw member when it is screwed together.
[0016]
  On the other hand, like the nut 18 shown in FIG. 8, a second recessed portion 19 is further formed in the cylindrical guide portion 17 of FIG.SecondThe recessed portion 19 is a cylindrical guide portion 17,Paint reservoir 11 (First recess 11)Along with coating film accumulationRitoAnd may be configured to function. The second recessed portion 19 can be formed in the form of an annular groove in the circumferential direction so as not to reach the seating surface 2. However, as shown in FIG.SecondIt is also possible to form three recessed portions 19 intermittently in the circumferential direction, for example, at equiangular intervals of 120 °.
[0017]
  Returning to FIG. 1, the reduced-diameter female screw portion 8 has a circular cross section that is uniformly reduced over the entire circumference so that the inner diameter of the female screw is smaller than the inner diameter of the main female screw portion 7. The imaginary line connecting the threads (or valleys) of the main female threaded portion 7 is a straight line parallel to the screw axis, but the imaginary line connecting the tips or valley diameters of the threaded threads of the reduced diameter female threaded portion 8 is the outlet side end. The tip side of the portion 5 is a straight line or a curve having a slight inclination closer to the screw shaft, and the degree of diameter reduction is greater at the tip. In the relevant drawings of the present case, the degree of diameter reduction may be exaggerated more than the actual size for easy understanding, and does not necessarily represent the form of the actual product.
[0018]
  The reduced-diameter female screw portion 8 is formed of a thread having a little less than three threads, and a wavy unevenness 20 that is continuously repeated in the circumferential direction is formed on the screw thread at that portion, as shown in FIG. The wavy unevenness 20 is formed continuously over these threads, and the protrusions 22 (hereinafter also referred to as loosening prevention protrusions) and the recesses 24 of the protrusions 20 are adjacent to each other between the adjacent threads. They are formed at positions corresponding to each other on a straight line crossing the mountain (a vertical surface including the screw shaft). Further, for example, twelve irregularities 20 are formed in one circumference of the reduced diameter female thread portion 8.
[0019]
  In this embodiment, the starting point of the concavo-convex 20 is the tip surface of the outlet side end portion 5, and the end point is a surface parallel to the tip surface in the vicinity of the boundary portion between the reduced diameter female screw portion 8 and the main female screw portion 7 (on the screw shaft). On the other hand, since the screw thread forms a spiral, the unevenness 20 is not completely divided in the thickness direction in the vicinity of the start point and the end point of the unevenness 20, and its meaning On the other hand, the unevenness 20 is formed in a complete shape with respect to the thread of the slightly smaller thread of the reduced-diameter female thread portion 8.And the number of the convex parts 22 is good to set to the range of 6-20 pieces. This range is suitable for keeping the balance between the effect of preventing the seizure and the tightening torque and the effect of preventing the loosening.
[0020]
  Reduced diameter female thread 8The top of the screw thread in the circumferential directionConstituteWavyThe specific shape of the concavo-convex 20 is, for example, an undulating shape in a circular arc shape, a triangular or trapezoidal shape in which the protrusion for preventing looseness is wide from the distal end side to the proximal end side in a plan view, It can be an inverted trapezoidal shape or the like. In any shape, the loosening prevention convex portion 22 of the concave and convex portion 20 protrudes toward the center side of the reduced diameter female screw portion 8, and the concave portion 24 is formed so as to recede from the central side of the reduced diameter female screw portion 8. The tip of the loosening projection 22 is substantially coincident with the tip of the thread of the reduced diameter female thread 8 described above, and the bottom of the recess 24 is substantially coincident with the bottom of the valley of the reduced diameter female thread 8. The unevenness 20 is also reduced in diameter by the reduced diameter of the reduced diameter female screw portion 8, and as a result, the diameter d1 of the inscribed circle 26 that connects the tips of the plurality of loosening projections 22 that repeat continuously in the circumferential direction is screwed. It is made smaller than the trough diameter of the bolt. On the other hand, the inscribed circle connecting the bottoms of the plurality of recesses 20 is larger than or equal to the valley diameter of the bolt. Since the cross-sectional area of the distal end portion of the loosening prevention convex portion 22 is smaller than that of the base end portion, it is easily elastically deformed, and therefore the tightening torque can be reduced. As mentioned aboveWavyUnevenness 20AsIf it forms into the shape of an arc, the contact area between the convex portion 22 and the screw portion of the male screw member will be reduced, the effect of preventing seizure will be increased, and the die life will be improved. On the other hand, the trapezoidal shape can increase the locking effect.
[0021]
  In addition, a suitable number of irregularities 20 (in other words, the loosening projections 22) provided on the reduced diameter female screw portion 8 in consideration of the balance between the locking effect, the tightening torque, and the mold life is the average inner diameter d of the reduced diameter female screw portion 8. However, since it differs depending on the thread pitch p of the reduced-diameter female screw portion 8 or the presence or absence of quenching, the degree, etc., for example, the average inner diameter d of the reduced-diameter female screw portion 8 shown in FIG. In this case, it is desirable to determine the size and number of the unevenness 20 so that the pitch s of the unevenness 20 is in the range of 0.1 to 0.5d.
[0022]
  FIG. 12 shows the operation when the nut 1 having such a structure and the male screw member 13 are screwed together. As shown in (a), when the nut 1 is screwed into the male threaded portion 14 of the male threaded member 13 from the foreign matter removing convex portion 9 to the main female threaded portion 7 (the male threaded member 13 is threadedly engaged with the nut 1). In the latter half of the screwing of the male screw member 13 and the nut 1 or in the vicinity of the terminal end, the tip of the male screw member 13 reaches the reduced diameter female screw portion 8 as shown in FIG.
[0023]
  Thereafter, the diameter d1 (FIG. 10 (a)) of the inscribed circle 26 of the large number of loosening projections 22 in the reduced diameter female screw portion 8 is smaller than the valley diameter of the male screw member 13, so the nut 1 and the male screw member 13 As shown in FIG. 13, the plurality of loosening projections 22 of the reduced diameter female threaded portion 8 of the nut 1 come into contact with the valley bottom 27 of the male threaded portion 14 at a number of positions in the circumferential direction. The loosening prevention convex portion 22 and the valley bottom 27 exert a pressing force on each other. For this reason, the locking protrusion 22 is elastically compressed, but since there are recesses 24 at both ends of the locking protrusion 22, conceptually speaking, the compressed meat portion of the locking protrusion 22 is on both sides. Easy to escape. That is, the compressive force acting on the outer side in the diameter direction on the locking protrusions 22 is easily dispersed to the recesses 24 on both sides, and therefore, an excessive increase in torque at the time of screwing can be suppressed as compared with the case without the protrusions 20. After the completion, a good function of preventing loosening is performed in a pressure contact state between the plurality of loosening convex portions 22 and the valley bottom 27. FIG. 12C shows such a state.
[0024]
  The inner diameter of the reduced-diameter female screw portion 8 is reduced as the reduced-diameter female screw portion 8 and the male screw portion 14 of the nut 1 are screwed together while exerting a pressing force between the tightening convex portion 22 and the valley bottom 27 described above. Normally, the diameter is elastically expanded to some extent. In that case, the inner diameter taper angle of the reduced diameter female thread portion 8 may be reduced by a predetermined amount from α2 to α3 in FIG. In this state, a tensile force in the circumferential direction acts on the reduced diameter female screw portion 8, and this tensile force acts as a pressing force on the valley bottom 27 of the male screw portion 14 through a number of tightening convex portions 22. Sufficient anti-loosening effect is exhibited without causing excessive increase in tightening torque or seizure.
[0025]
  As the reduced diameter female thread portion for preventing loosening, for example, a known configuration disclosed in Japanese Patent Laid-Open No. 55-30593 and Japanese Patent Publication No. 3-31926, that is, the outlet side end portion of the nut is caulked at a plurality of locations from the outside. A configuration in which a plurality of (for example, three) loosening prevention convex portions (reduced diameter female screw portions) are formed on the inner periphery of the female screw can also be employed in the present invention. FIG. 30 shows a locking nut 101 having three projections 102 formed by projecting female threads inward. However, in the case of this configuration, the convex portion 102 formed by locally caulking a plurality of locations of the nut may vary in position and dimensional accuracy. Also, the projecting part that protrudes locally and the male threaded part of the bolt are pressed against each other, resulting in excessive friction, requiring extremely large torque for tightening, and seizing when tightening with a power wrench or the like. Sometimes. Therefore, it can be said that the structure shown in FIG. 12 and the like is more desirable because it has high dimensional accuracy and hardly causes seizure during tightening.
[0026]
  Next, the manufacturing method of the internal thread part of the internal thread member of the said nut 1 and a reduced diameter internal thread part is demonstrated. For example, as shown in FIG. 26 (a), a nut material is first set in a forging die and a known forging operation is performed to form an outer surface thereof, and a main female screw for forming a main female screw portion 7 therein. The lower hole 70 and the outlet side female screw lower hole 72 in which the unevenness 20 (FIG. 10B) is formed are formed simultaneously. At this time, the position of the front end of the tightening convex portion 22 of the concave and convex portion 20 substantially coincides with the top of the female screw thread to be processed later, that is, the inner surface of the main female screw lower hole 70, and the position of the bottom of the concave portion is the female screw to be processed later. To be almost equal to the bottom of the valley.
[0027]
  Next, the internal thread 74 is cut by a known method such as tapping in succession to both the main female thread lower hole 70 and the outlet side female thread lower hole 72 of the intermediate product N1. Thereby, the unevenness | corrugation 20 (FIG.10 (b)) which overlapped with the screw thread is formed in the threaded part of the exit side edge part 5 in the perimeter.
[0028]
  Further, the intermediate product N2 after threading is pressed with a press die 82, for example, as shown in FIG. Here, the taper angle θ1 of the taper outer peripheral surface 6 ′ of the outlet-side end portion 5 of the nut 1 before diameter reduction is formed smaller than the taper angle θ2 of the nut 1 after diameter reduction shown in FIG. By crimping the taper outer peripheral surface 6 'of the intermediate product N2 with the press surface 83 formed corresponding to the taper angle θ2, as shown in FIG. 27B, the taper outer peripheral surface 6 of the nut 1 as the final product is obtained. Is plastically deformed to a taper angle θ2. As a result, the outlet side end portion 5 is reduced in diameter.
[0029]
  As another manufacturing method of the nut 1, as shown in FIG. 26 (b), the outlet side female screw lower hole 72 in which the unevenness 20 (FIG. 10 (b)) is formed is first formed by forging, and then the main It is also possible to use a method in which the female screw lower hole 70 to be formed is removed by a press and subjected to threading and diameter reduction steps. Moreover, as shown in (c), after forming the main female screw lower hole 70 by forging in the axial direction through forging, an outlet-side female screw lower hole 72 having irregularities 20 is formed by pressing. It is also possible to combine the steps in the order of threading over the holes 70 and 72 and reduction in diameter.
[0030]
  Incidentally, as the concave-convex shape of the reduced diameter female thread portion 8, a trapezoidal concave-convex portion 92 (strictly speaking, the tip surface of the trapezoidal convex portion becomes an arc concave surface as shown in FIG. In the case where the total sum of the individual screw thread areas s1 is composed of thread threads that are all continuous for one round, for example, 1/3 to 1/4 or less), triangular irregularities 94 as shown in FIG. It can also be.
[0031]
  The present invention is not limited to nuts, and can be widely applied to members having a female screw structure. For example, as shown in FIG. 29 (a), the diameter of the outlet side end portion of the female screw portion 96 having a convex locking function formed on the frame member 95 is reduced, and the inner peripheral female screw By providing unevenness on the thread, the same effect as the nut 1 can be obtained. Further, as shown in FIG. 29B, the present invention can be similarly applied to a pipe-shaped female screw member 97. The portion A in the figure corresponds to the structure of the female screw portion 14 and the reduced diameter female screw portion 8 described above.
[0032]
(Example 2)
  14 (a) and 14 (b) show a nut 150 having a coating film peeling function or a dust removing function and a loosening preventing function as one embodiment according to the second configuration of the female screw member of the present invention. ing. In addition, the same code | symbol is attached | subjected to the part which is common in the nut 1 of Example 1, and description is abbreviate | omitted. In the nut 150, the edge 10a of the coating film peeling surface 10 functions as an edge or blade part for scraping off the coating film layer attached to the male screw part. Further, as shown in FIG. 15, among these foreign matter removing convex portions 9, the first line (seat surface 2 side) has its inner edge 9b extending from the central axis O in a plane perpendicular to the central axis O of the spiral. The relief portion 30 is formed such that the distance R from the leading end of the spiral (the coating film peeling surface 10) continuously increases toward the distal end of the spiral.
[0033]
  As described above, since the relief portion 30 is formed in the first line of the convex portion 9, as shown in FIG. 16, it is foreign matter that comes into contact with the coating film P or the like attached to the male screw portion 14 of the male screw member 13. Only the vicinity of the leading end of the removal convex portion 9 is present, and the contact portion between the foreign matter removal convex portion 9 and the coating film P is reduced. Thereby, the convex part 9 for foreign substance removal can be screwed up, suppressing frictional resistance, such as the coating film P.
[0034]
  Next, as shown in FIG. 17, the relief portion 30 has a continuous distance R from the central axis O of the spiral to the inner edge 9 b at a substantially constant ratio ΔR per unit rotation angle λ centered on the central axis O. It is formed so as to be larger. In this case, the distance R is R0 at the screwing leading end 10b. However, if the distance R is moved along the spiral by the unit rotation angle λ, R = R1 = R0 + ΔR, 2λ and R = R2 = R0 + 2ΔR, 3λ and R = R3 = R0 + 3ΔR. As shown in FIG. 18, the escape portion 30 has the distance R that increases continuously at a predetermined rate around the central axis O up to a predetermined rotation angle λ1, and a constant distance in the subsequent angular sections. You may form so that it may become R1. 18 (a) shows an example in which the inner edge 9b is formed in an arc shape or other curved shape in the section up to the rotation angle λ1, and FIG. 18 (b) is similarly formed in a straight line shape. Each example is shown.
[0035]
  In the above-described embodiment, the coating film peeling surface 10 is formed so as to rise substantially perpendicular to the tangential direction of the inner peripheral surface, but the angle between the coating film peeling surface 10 and the tangential direction of the inner peripheral surface is set to a coating film or the like. It is also possible to form an obtuse angle or an acute angle within a range that does not hinder the peeling.
[0036]
  Further, as shown in FIG. 17B, an angle formed between the inner edge 9b of the foreign matter removing convex portion 9 (or its tangent plane P at the screwing leading end 10b) and the coating film peeling surface 10 at the screwing leading end 10b. If φ is an acute angle, the cutting effect on foreign matter such as a coating film can be enhanced. In this case, the angle φ is preferably adjusted in the range of 70 to 80 °. If the angle φ is too small, the die life may be shortened when the screwing leading end 10b is manufactured by the die forging method.
[0037]
  In the above embodiment, the relief portion 30 is formed on the first strip of the three foreign matter removal convex portions 9, but the relief portion 30 is also formed on the second or third foreign matter removal convex portion 9. Can do.
[0038]
(Example 3)
  19 and 20 show a nut 200 having a coating film peeling function or a dust removing function and a loosening preventing function as an embodiment of the third configuration of the female screw member of the present invention. In addition, the same code | symbol is attached | subjected to the part which is common in the nut 1 of Example 1, and description is abbreviate | omitted. In the nut 200, in order to remove foreign matter at three substantially equal angular intervals adjacent to the leading end side in the screwing direction of the main female screw portion 7 formed on the hexagonal portion 3 side. A foreign matter removing female screw portion 40 is formed as the foreign matter removing convex portion 9. As shown in FIG. 21 (a), three thread segments 41, 42, and 43 are formed in the foreign matter removing female thread portion 40 side by side in the axial direction. The height of the segments 41, 42, and 43 decreases in steps as it goes from the main female screw portion 7 side to the seat surface 2 side. FIG. 21B shows the thread segments 41 to 43 of the foreign matter removing female screw portion 40 formed in three places in a straight line, the horizontal axis is the length of the foreign matter removing female screw portion 40, and the vertical axis is a screw pilot hole. The height from is shown. Note that the third thread segment 43 has substantially the same height as the main female thread portion 7.
[0039]
  As shown in FIG. 22, when the male threaded portion 14 of the male threaded member 13 such as a bolt and the nut 1 are screwed together, the foreign matter removing female threaded part 40 is connected to the male threaded member 13 prior to the main female threaded part 7. Screwed onto the male screw portion 14. At this time, in order to remove the coating film and the like attached to the male screw portion 14, as shown in FIG. 23, when the male screw member 13 is screwed in the screwing direction, as a first step, the foreign matter removing female screw portion 40 is obtained. A predetermined amount of the coating film P1 and the like is removed by the coating film peeling surface 10 of the thread segment 41 formed on the screw segment 41, and the coating film P2 and the like remaining in the removal process of the first stage in the second stage are removed from the thread segment 42. Further, the coating film peeling surface 10 is partially removed. In the third stage, the coating film is removed at the third thread segment 43. Since the thread segment 43 is substantially the same height as the main female thread portion 7, the remaining coating film is removed. Almost all of P3 and the like can be removed by the coating film peeling surface 10. The coating film and the like thus removed are accommodated in the coating film reservoir 11 as in FIG.
[0040]
  In addition, as shown to Fig.24 (a), the height of all the thread segments can also be made mutually different. The figure shows an example in which a total of nine thread segments 44 to 52 of the foreign matter removing female thread portion 40 formed at three locations are formed so as to increase in nine steps from the seating surface side. FIG. 24B shows the relationship between the length (horizontal axis) and the height (vertical axis) of each foreign matter removing female thread portion 40 for the thread segments 44 to 52. As described above, by further subdividing the amount of change in height between the thread segments 44 to 52, it is possible to further reduce the resistance associated with the removal of the coating film and the like, and thus it is possible to tighten the screws more smoothly. . In the present embodiment, the description has been given of the case where each part of the foreign matter removing female screw portion 40 divided by the foreign matter reservoir portion 11 includes three thread segments. However, the number of thread segments is limited to this. It is not something. In the case where the foreign matter reservoir portion 11 is not formed in the foreign matter removing female screw portion 40, the height of the female screw thread can be continuously changed as shown in FIG.
[0041]
  Further, as shown in FIG. 25, a taper for reducing the diameter of the foreign matter removing female threaded portion 40 toward the main female threaded portion 7 side.PaIt can also be formed. In the foreign matter removing female thread portion 40, specifically, the thread segments 60 to 62 are formed in the tapered pilot hole T at substantially the same height. Thereby, the protrusion amount of the said thread segment 60-62 with respect to the screw lower hole 12 of the main internal thread part 7 becomes so small that it goes to the seat surface 2 side from the main internal thread part 7 side. In FIG. 25, for convenience of explanation, a table is used.PaThe inclination is slightly exaggerated.
[Brief description of the drawings]
FIG. 1 is a front view and a sectional view of a nut according to a first embodiment of the present invention.
FIG. 2 is a perspective view of the nut from the seating surface side.
FIG. 3 is a view showing a bottom surface of the nut.
4 is a cross-sectional view of a modification of FIG.
FIG. 5 is a partial cross-sectional view showing a threaded state of a male screw member and a nut.
FIG. 6 is an explanatory diagram of an action at the time of screwing.
FIG. 7 is an explanatory view when a guide portion is formed on the seat surface side of the nut.
FIG. 8 is an explanatory diagram when another guide portion is formed.
FIG. 9 is a bottom view when the second recessed portion is intermittently formed in the circumferential direction.
10 is a cross-sectional view and a plan view taken along the line CC in FIG. 1. FIG.
FIG. 11 is a diagram showing an inner diameter of a reduced diameter female thread portion, a pitch of unevenness, and a thread pitch.
FIG. 12 is an explanatory view of the action of locking by the elastic deformation of the outlet side end when screwed with the male screw member.
FIG. 13 is a diagram for explaining the operation of the concavities and convexities of the reduced diameter female thread portion.
FIG. 14 is a perspective view and a partially enlarged view of a nut according to a second embodiment of the present invention.
FIG. 15 is a view showing a bottom surface of the nut.
FIG. 16 is a plan sectional view showing a screwed state of the nut and the male screw member.
FIG. 17 is a view showing the vicinity of the leading end of the foreign matter removing convex portion of the nut.
FIG. 18 is a view showing a modification of FIG.
19 is a perspective view of a nut according to Embodiment 3. FIG.
FIG. 20 is a view showing a cross section and a bottom surface of the nut.
FIG. 21 is a view showing a cross section of the foreign matter removing female screw portion.
FIG. 22 is a partial cross-sectional view showing a screwed state of the nut and the male screw member.
FIG. 23 is an operation explanatory view when the nut is screwed.
FIG. 24 is a view showing a modified example of the foreign matter removing female screw portion.
FIG. 25 is a diagram showing a case where the foreign matter removing female thread portion is formed in a tapered shape.
FIG. 26 is a view for explaining a method of manufacturing the female screw portion and the reduced-diameter female screw portion of the nut according to the present invention.
FIG. 27 is a view for explaining the diameter reduction process.
FIG. 28 is a view showing another uneven shape of the reduced diameter female thread portion.
FIG. 29 is a view showing still another embodiment of the nut of the present invention.
FIG. 30 is a view showing a modification of the reduced diameter female thread portion.
[Explanation of symbols]
  1, 16, 18, 150, 200 Nut (Female thread member)
  2 Seat
  3 Hexagon
  5 Exit end
  7 Main female thread
  8 Reduced female thread
  9 Convex part for removing foreign matter
  10 Coating surface (foreign matter removal)Leaving part)
  11 Foreign matter accumulation part (concave part, paint film accumulation part)
  17 Cylindrical guide
  19 Second recess
  20, 92, 94 irregularities
  22 Loosening prevention convex part
  24 recess
  30 escape
  40 Foreign matter removal female thread
  41-52 thread segment

Claims

The female thread portion formed in the female screw hole of the female screw member, with the external thread portion of the male screw member is screwed, the inlet end of the initiator of the screwing of the female screw member with respect to the male screw member, the outlet side end portion of the opposite side As
In the female screw hole at the inlet side end portion, a plurality of foreign matter removing convex portions that are screwed into the male screw portion and a foreign matter reservoir portion that contains a foreign material deeper than the thread valley diameter of the female screw hole are disposed,
The end face of the threaded leading side of the foreign matter removing protrusions screwed to the external thread portion, constitutes a foreign matter removing portion that will be formed adjacent to the foreign substance reservoir,
And removing the foreign matter attached to the male screw portion by the foreign substance removal section, it accommodates the removed foreign matter foreign material reservoir,
The female screw portion of the outlet side end portion, wavy irregularities top of the thread of the female screw portion of that is continuously repeated in the circumferential direction so as to shrink the inner diameter projecting to intermittently inward is formed, The concave and convex portions and concave portions of the concave and convex portions are located at portions corresponding to each other in the axial direction of the female screw portion, and the convex portions bite into the valley portions of the male screw portion to form a reduced diameter female screw portion for preventing loosening. and,
The female screw member is formed by the female thread portion at the inlet side end portion to reduce the screwing length of the female screw portion, and the wavy unevenness disposed on the entire circumference of the female screw portion at the outlet side end portion. A reduced diameter female thread portion for preventing loosening is combined at a position where the inlet side end portion and the outlet side end portion are separated,
A female screw member characterized in that a reduction in screw fastening force due to a decrease in screwing length at an inlet side end portion of the screwing is avoided by a reduced-diameter female screw portion for preventing loosening at an outlet side end portion of the screwing .