JP4163299B2

JP4163299B2 - Fastening protection device

Info

Publication number: JP4163299B2
Application number: JP25646898A
Authority: JP
Inventors: 祥行鎌中; 康善永木; 光司坪岡
Original assignee: Nagaki Seiki Co Ltd
Current assignee: Nagaki Seiki Co Ltd
Priority date: 1998-09-10
Filing date: 1998-09-10
Publication date: 2008-10-08
Anticipated expiration: 2018-09-10
Also published as: JP2000087944A

Description

【０００１】
【発明の属する技術分野】
本発明は、鉄塔等における鉄板同士等をネジ部材とナット部材とで締結した締結部における前記ナット部材を取り外し不能の状態としてこれを防護するようにした締結部の防護装置に関するものである。
【０００２】
【従来の技術】
一般に、鉄塔等における鉄板同士を接続するには、ボルト部材等のネジ部材を両鉄板の貫通孔に挿入し、このネジ部材の先端からナットを螺合し、更にロックナットを前記ネジ部材に螺合して締め付けている。
【０００３】
ところが、このナット、ロックナットが表面に露出しているために、悪戯等によってロックナットを緩めるとともにナットをネジ部材から外して鉄板同士の締結状態を解いた状態とする事態が起きている。
【０００４】
【発明が解決しようとする課題】
本発明は、上記従来の問題を解消し、締結部の締結状態を悪戯等によって解いた状態にすることを確実に防止することができる締結部の防護装置を提供することを目的としている。
【０００５】
【課題を解決するための手段】
上記目的を達成するために、本発明は、被締結部材をネジ部材とナット部材とで締結した締結部において前記ナット部材の取外しを防止するようにした締結部の防護装置であって、前記被締結部材を前記ネジ部材とナット部材で締結した状態で、リング体の内面側に一巻以上のコイル状のスプリング部材を軸方向の動きを所定範囲内に規制して内包し、このスプリング部材の端部に係脱可能に係合する係合部をリング体に設けて構成したナット取外し防止具を、前記ネジ部材の端部に押し付けつつ正方向に回転させて前記スプリング部材を、その端部が前記係合部に係合する状態で前記ネジ部材のネジ部に螺合させつつ前進させ、前記ナット取外し防止具が前記ナット部材または被締結部材に当接し軸方向の移動を規制された状態で更に前記ナット取外し防止具を正方向に回転させて前記スプリング部材のみを更に螺進させ、前記スプリング部材の端部を前記係合部から離脱させることによって、前記ナット取外し防止具を正逆両方向に回転自由として、前記ナット取外し防止具を取外し不能状態としてナット部材を防護するように構成したことを特徴とする。
【０００６】
【０００７】
【発明の実施の形態】
以下、本発明に係る締結部の防護装置の実施の形態について、図を参照しつつ説明する。
【０００８】
図１は本発明の第１実施形態の締結部材の防護装置の使用状態を示し、（ａ）はボルト部材（ネジ部材）に螺合されて鉄板同士を締結するナット部材をキャップ部を備えたナット取外し防止具で覆うときの状態を示す断面図、（ｂ）はナット取外し防止具でナット部材を覆った状態で前記防止具をナット部材の螺進方向とその逆方向に回転自由とした状態を示す断面図、図２は前記防止具の断面図、図３はボルト部材に螺合して鉄板同士を締結したナット部材を前記防止具で覆って、前記防止具をナット部材の螺進方向とその逆方向に回転自由とした状態に至る過程を示す断面説明図である。
【０００９】
図１（ａ）、（ｂ）において、符号１、２は、鉄塔等に用いられる鉄板であって、これら鉄板１、２同士をボルト部材３とナット４及びロックナット５からなるナット部材６で締結している。即ち、鉄板１、２同士の対向面を接面して合わせた状態で、鉄板１、２のボルト挿入孔１ａ、２ａにボルト部材３のネジ部３ａを挿入してからナット４を螺合し、更にロックナット５を螺合して締め付けて鉄板１、２同士を、ボルト部材３の頭部３ｂとナット部材６との間に締結している。
【００１０】
第１実施形態の締結部の防護装置では、上記のように鉄板１、２同士を締結するボルト部材３のネジ部３ａに螺合したナット部材６に、中央部に貫通孔７ａが形成されると共に、筒状のキャップ部７ｐを一体に形成したリング体７ｂを主構成部品とするナット取外し防止具（以下単に防止具と称する場合がある。）７を被せて覆うようにしており、図２にも示すように、この防止具７のリング体７ｂの内面側前後縁には小突出縁７ｃ、７ｄが突設され、このリング体７ｂの内面側に略２巻のコイル状のスプリング部材８が配設されている。スプリング部材８は、その自然状態の径が前記ネジ部３ａの径より若干小で、前記ネジ部３ａにこれを抱き込むようにして螺合する。またスプリング部材８は両小突出縁７ｃ、７ｄによって軸方向の動きを所定範囲内に規制される。更に、リング体７ｂの内面の後縁近傍箇所には、スプリング部材８の後端に当接する突起部７ｅが設けられている。尚、この突起部７ｅはリング体７ｂに一体に形成するかもしくはピンをリング体７ｂに植設することによって形成するとよい。
【００１１】
前記防止具７は、図３（ａ）に示すように、まずボルト部材３のネジ部３ａに螺合されたナット部材６を前記キャップ部７ｐで覆うように矢印方向に被せ、次に図３（ｂ）に示すように、前記防止具７を押しつけつつ矢印に示すように螺進方向に回転させると、スプリング部材８はボルト部材３のネジ部３ａにおけるロックナット５から突出した部分に、前記ネジ部３ａにくい込むようにして螺合し、かつ前記突起部７ｅによってスプリング部材８の後端部が押され、キャップ部７ｐを備えたリング体７ｂと一体となって螺進方向（図にて左方向）へ回転しつつ前進する。
【００１２】
更に、図３（ｃ）に示すように、前記防止具７の先端が鉄板２に密着するまでキャップ部７ｐを備えたリング体７ｂとスプリング部材８とを螺進方向に前進させる。前記防止具７が鉄板２に密着した状態で更に回転させると、キャップ部７ｐを備えたリング体７ｂは鉄板２により螺進方向への進行が拘束されているため、回転力のみがスプリング部材８に伝達され、図３（ｄ）に示すように、スプリング部材８だけがネジ部３ａに沿って更に前進する。
【００１３】
更に回転を続けることにより、図３（ｅ）に示すように、スプリング部材８の後端が突起部７ｅから離反する。この状態では、キャップ部７ｐを備えたリング体７ｂは、正逆両方向に自由に回転して空回りする。
【００１４】
これにより、キャップ部７ｐを備えたリング体７ｂは、前記ネジ部３ａに抱き込むようにして固定されたスプリング部材８に前記小突出縁７ｃが係合して軸方向の移動が拘束され、また前記リング体７ｂは何れの方向に回転させても空回りすることになり、後退させることが不可能となるので、前記防止具７を取り外すことが不可能となり、この防止具７に覆われたナット部材６は取り外すことができなくなる。
【００１５】
したがって、ボルト部材３に螺合して鉄板１、２同士を締結したナット部材６は、悪戯等でボルト部材３から取り外すことができず、鉄板同士１、２の締結状態を解くことができなくなり、鉄塔が危険な状態となることを未然に防ぐことができる。
【００１６】
図４は第２実施形態の締結部の防護装置を示す要部の断面図、図５はその別例の締結部の防護装置を示す要部の断面図である。尚、上記した第１実施形態の締結部の防護装置における同一部材、同一箇所には同一符号を付して説明する。
【００１７】
第２実施形態及び別例の締結部の防護装置は、基本構成が第１実施形態と同一であり、締結部の防護のための作用も基本的には同一である。異なる点は、図４、図５に示すように、ナット取外し防止具７のリング体７ｂにおけるロックナット５側に滑り用スペーサ１４、１４Ａを取付けている点にあり、これによって逆回転時のリング体７ｂが確実に前記スプリング部材８に対し空回りするようにしている。
【００１８】
即ち、図４に示す第２実施形態の締結部の防護装置では、リング体７ｂのロックナット５側内面に、止めリング１５によって円輪板状の滑り用スペーサ１４を取付けており、図５に示す締結部の防護装置では、リング体７ｂのネジ部３ａ側内面のロックナット５側に内向きに突出した環状突起部７ｃに沿わせて円輪状の滑り用スペーサ１４Ａを配設している。
【００１９】
図６は第３実施形態の締結部の防護装置を示している。この第３実施形態のナット取外し防止具７Ｄは、第１実施形態のキャップ部７ｐに相当するものを有さず、前記ナット部材６をカバーする機能は有しない。しかしこの第３実施形態も、第１実施形態と同様のリング体７ｂ、小突出縁部７ｃ、７ｄ、スプリング部材８、突起部７ｅを備えるように前記防止具７Ｄを構成することによって、図６に示すように、前記リング体７ｂの先端面がロックナット５に当接した状態で更にリング体７ｂを回転し続けると、スプリング部材８の後端が突起部７ｅから離反して、リング体７ｂが正逆両方向に自由に回転して空回りすることになり、ナット部材５、６を取外すことができない状態とすることができる。すなわち、ナット部材５、６を弛める方向に回転させると前記リング体７ｂに接し、ネジ部３ａにはダブルナット効果が生じ、前記ナット部材５、６をそれ以上弛める方向に回転させることができなくなり、ナット部材５、６の取外しが不可能となる。
【００２０】
図７は第４実施形態の締結部の防護装置を示し、（ａ）はボルト部材に螺合されて鉄板同士を締結するナット部材をキャップ部を備えたナット取外し防止具で覆うときの状態を示す断面図、（ｂ）は前記防止具でナット部材を覆った状態で前記防止具をナット部材の螺進方向とその逆方向に回転自由とした状態を示す断面図、図８は第４実施形態の締結部の防護装置に用いるスプリング部材の正面図、図９はスプリング部材の外向き折曲突出部が係入される切欠凹部を示す前記防止具の部分断面図である。尚、上記した第１実施形態における同一部材、同一箇所には同一符号を付して説明を省略する。
【００２１】
第４実施形態の締結部の防護装置では、図７（ａ）（ｂ）に示すように、ナット取外し防止具７Ａのリング体７ｂにおける内面の一部に、スプリング部材８Ａの端部に形成された外向き折曲突出部８ａ（図８参照）が係入可能な切欠凹部７ｍが形成され、この切欠凹部７ｍの前側にはこれに連続して、スプリング部材８Ａの外向き折曲突出部８ａが回転自在に収容される環状凹部７ｎが形成されている（図９参照）。
【００２２】
この第４実施形態の締結部の防護装置によると、図７（ａ）に示すように、前記防止具７Ａのキャップ部７ｐをナット４とロックナット５とからなるナット部材６に被せて覆った状態では、スプリング部材８Ａの外向き折曲突出部８ａはリング体７ｂの切欠凹部７ｍに係入されていて、スプリング部材８Ａはキャップ部７ｐを備えたリング体７ｂを螺進方向へ回転するとこのリング体７ｂと一体に回転する。
【００２３】
キャップ部７ｐを備えたリング体７ｂを鉄板２に密着した状態で、更にこのリング体７ｂを同方向へ回転すると、図７（ａ）、（ｂ）に示すように、スプリング部材８Ａは、その外向き折曲突出部８ａが前記切欠凹部７ｍに係合しているので、前記ネジ部３ａに沿って螺進方向（図にて左方向）へ前進して、その外向き折曲突出部８ａが前記切欠凹部７ｍから離反して環状凹部７ｎに移行することになる。
【００２４】
この状態では、キャップ部７ｐを備えたリング体７ｂは、正逆両方向に自由に回転して空回りする。これにより、前記リング体７ｂはスプリング部材８Ａに前記小突出縁７ｃが係合することにより軸方向の移動が拘束され、またリング体７ｂは何れの方向に回転させても空回りすることになるので、前記リング体７ｂを取り外すことが不可能となり、前記キャップ部７ｐに覆われたナット部材６は取り外すことができなくなる。
【００２５】
したがって、ボルト部材３に螺合して鉄板１、２同士を締結したナット部材６は、悪戯等でボルト部材３から取り外すことができず、鉄板同士１、２の締結状態を解くことができなくなり鉄塔が危険な状態となることを未然に防ぐことができる。
【００２６】
図１０は第１参考例の締結部の防護装置を示す断面図、図１１は図１０におけるＡ−Ａ線断面図であって、（ａ）は外側リング体をナット部材の螺進方向に回転するときの状態を示し、（ｂ）は外側リング体をその逆方向に回転するときの状態を示している。尚、上記した第１実施形態の締結部の防護装置における同一部材、同一箇所には同一符号を付して説明を省略する。
【００２７】
この第１参考例の締結部の防護装置では、ナット取外し防止具７Ｂを、ボルト部材３のネジ部３ａのロックナット５から突出した部分に螺合する円盤状の支持体９と、ナット４とロックナット５とからなるナット部材６を覆う円筒状のキャップ部９０ａを一体に備えた外側リング体９０とから構成している。支持体９は外側リング体９０を回転自在かつ軸方向移動不可の状態で支持している。また支持体９と外側リング体９０との間には、外側リング体９０の螺進方向のみの回転を支持体９に伝達し、逆方向には外側リング体９０を自由に回転させる一方向回転伝達手段が配設されている。
【００２８】
前記防止具７Ｂは図１０、図１１に示すように、内周に環状凹部９１が形成された外側リング体９０の後端部に配設されてボルト部材３のネジ部３ａに螺合され、外周に環状凹部９ａを有する支持体９と、支持体９の環状凹部９ａおよび外側リング体９０の環状凹部９１内に配設され、一端の外側に折曲げた折曲部１０ａが外側リング体９０の環状凹部９１に形成された孔部７ｓに挿入係止され、他端１０ｂ側が内側に向けて曲がるように形成された有端略円状バネ体１０と、外側リング体９０を螺進方向に回転させたときには有端略円状バネ体１０の他端１０ｂが係止してこの有端略円状バネ体１０と支持体９とを外側リング体９０と一体回転させるために支持体９の環状凹部９ａの内面に外向きに突設された係止用突起部１１とを備えている。尚、この係止用突起部１１は図に示すように支持体９に植設したピンで構成するかもしくは支持体９に一体に形成するとよい。
【００２９】
この第１参考例の締結部の防護装置では、図１１（ａ）に示すように、外側リング体９０を螺進方向（図にて時計方向）に回転させると、有端略円状バネ体１０の他端１０ｂが内側に曲がった状態で支持体９の環状凹部９ａの内面に外向きに突設された係止用突起部１１に係止するので、支持体９は外側リング体９０と一体に回転する。支持体９はボルト部材３のネジ部３ａに螺合しているので、外側リング体９０と一体となって前進する。
【００３０】
また、図１１（ｂ）に示すように、外側リング体９０を螺退方向（図にて反時計方向）に回転させると、有端略円状バネ体の１０の他端１０ｂと係止用突起部１１の係止状態が解除されて、この有端略円状バネ体１０の他端１０ｂは係止用突起部１１に乗り上げて回転するので、外側リング体９０は自由回転して空回りする。
【００３１】
外側リング体９０と支持体９とは、これらの環状凹部９１、９ａ内に介装された有端略円状バネ体１０によって、軸方向の相互移動が拘束されているので、外側リング体９０を取り外すことが不可能となり、この外側リング体９０のキャップ部９０ａに覆われたナット部材６を取り外すことはできなくなる。
【００３２】
したがって、ボルト部材３に螺合して鉄板１、２同士を締結したナット部材６は、悪戯等でボルト部材３から取り外すことができず、鉄板同士１、２の締結状態を解くことができなくなり、鉄塔が危険な状態となることを未然に防ぐことができる。
【００３３】
図１２は第２参考例の締結部の防護装置を示し、（ａ）はその縦断面図、（ｂ）は（ａ）におけるＢ−Ｂ線正面断面図、図１３は要部の部材である止め輪の正面及びその後向き屈曲片の側面を示す図、図１４は要部の部材である支持体の正面図である。尚、上記した第１実施形態の締結部の防護装置における同一部材、同一箇所には同一符号を付して説明を省略する。
【００３４】
この第２参考例の締結部の防護装置では、図１２（ａ）、（ｂ）に示すように、ナット取外し防止具７Ｃを、ボルト部材３のネジ部３ａのロックナット５から突出した部分に螺合する支持体１２と、ナット４とロックナット５とからなるナット部材６を覆うキャップ部９３ａを一体に備えた外側リング体９３とから構成している。
【００３５】
円筒形の外側リング体９３は後端に内向き鍔部７ｔを有すると共に内面に環状凹部９４を有している。支持体１２はその外周部の前部が小径部１２ａに形成されているとともに後部が大径部１２ｂに形成されてこの大径部１２ｂの一部に係止用切欠凹部１２ｃが形成されている（図１４参照）。外側リング体９３の環状凹部９４には、先端に前記係止用切欠部１２ｃに係入可能な後向き屈曲片１３ａ（図１３参照）を有する有端略円輪形状の止め輪１３がその外周部において回転可能に嵌入されている。また外側リング体９３の環状凹部９４内には、止め輪１３の後端が当接される突起部１４が形成されている。尚、この突起部１４は、図に示すように、外側リング体９３に植設されたピンで構成するかもしくは外側リング体９３の内面に一体に突起部を突設して形成するとよい。
【００３６】
この第２参考例の締結部の防護装置では、止め輪１３と前記内向き鍔部７ｔとの間に支持体１２の大径部１２ｂを拘束状態に配置しているので、外側リング体９３と支持体１２とは常に軸方向位置が同一となっている。そして外側リング体９３を螺進方向に回転すると、前記突起部１４によって止め輪１３が押されて回転し、止め輪１３の後向き屈曲片１３ａが支持体１２の係止用切欠凹部１２ｃに係入されて、支持体１２を同方向に回転させるので、支持体１２は外側リング体９３と一体に回転する。逆に、外側リング体９３を螺退方向に回転すると、後向き屈曲片１３ａが前記係止用切欠凹部１２ｃから離反するので、外側リング体９３は空回りする。
【００３７】
これにより、外側リング体９３は前進動のみ可能で、後退動が不可能となり、この外側リング体９３に覆われたナット部材６は取り外すことができなくなる。
【００３８】
したがって、ボルト部材３に螺合して鉄板１、２同士を締結したナット部材６は、悪戯等でボルト部材３から取り外すことができず、鉄板同士１、２の締結状態を解くことができなくなり、鉄塔が危険な状態となることを未然に防ぐことができる。
【００３９】
なお、上記第１参考例、第２参考例において、外側リング体７Ｂ、９３を、図６に示す第３実施形態のリング体７ｂのように、ナット部材６を覆うキャップ部７ｐ、９３ａを省略した形状のものとすることができる。
【００４０】
図１５は第３参考例の締結部の防護装置を示し、（ａ）はその縦断面図、（ｂ）は要部の部材であるスプリング部材を示す正面図である。
【００４１】
この第３参考例は、ナット取外し防止具７Ｅを、ボルト部材３のネジ部３ａに螺合するコイル状のスプリング部材からなる支持体１２Ａと、前記スプリング部材（支持体）１２Ａの端部１２ｍに係脱可能に係合する係合突起５１を周面に備えた外側リング体９３Ａとから構成している。
【００４２】
前記コイル状のスプリング部材１２Ａは、ボルト部材３のネジ部３ａにくい込むように螺合する複数巻状態に形成され、その軸方向の動きは、外側リング体９３Ａに設けた小突出縁９３ｃ、９３ｄにより規制されている。スプリング部材１２Ａの後側の端部１２ｍは、図１５（ｂ）に示すように、半径方向外方に変形されている。この端部１２ｍは、外側リング部材１２Ａの内面後側に凹設した環状溝９３ｎ内を自由に回転することができる。また前記外側リング部材１２Ａには前記環状溝９３ｎ内に臨むようにピン形状の係合突起５１が設けられている。
【００４３】
前記外側リング体９３Ａを螺進方向に回転させたとき、すなわち、図１５（ｂ）の矢印方向に回転させたとき、前記係合突起５１がスプリング部材１２Ａの端部１２ｍに係合して、スプリング部材１２Ａを周方向に回転させる。他方外側リング体９３Ａを上記と逆の方向に回転させたときは、前記係合突起５１はスプリング部材１２Ａの端部１２ｍを半径方向内方に変形させるのみであって、前記端部１２ｍとは係合せず、スプリング部材１２Ａは静止したままで、外側リング体９３Ａは空回りする。すなわち前記係合突起５１は一方向回転伝達手段としての機能を営み、第１、第２参考例と同様、第３参考例も、外側リング体９３Ａは前進動のみ可能で、後退動が不可能となり、ナット取外し防止具７Ｅの取外しが不可能で、ひいてはナット部材６の取外しが不可能である締結部の防護装置となる。
【００４４】
本発明は上記実施形態に示す外、種々の態様に構成することができる。例えば図１６に示すように鉄板１、２同士を締結するボルト部材１０３の頭部１０３ｂにネジ軸１００を突設して、このネジ軸１００に第１実施形態で用いたようなナット取外し防止具７を螺合してボルト部材１０３の頭部１０３ｂを防護することができる。このような場合にも本発明を適用することができ、この場合には前記ネジ軸１００および頭部１０３ｂはそれぞれ、特許請求の範囲で云うネジ部材、ナット部材に該当する。
【００４５】
【発明の効果】
以上説明したように、本発明によれば、締結時のナット部材を取り外し不可能な状態にして確実に防護することができる。
【図面の簡単な説明】
【図１】本発明の第１実施形態の締結部の防護装置の使用状態を示し、（ａ）はナット部材をナット取外し防止具で覆うときの状態を示す断面図、（ｂ）は前記防止具でナット部材を覆った状態でリング体を螺進方向とその逆方向に回転自由とした状態を示す断面図である。
【図２】第１実施形態の締結部の防護装置におけるナット取外し防止具の断面図である。
【図３】第１実施形態の締結部の防護装置において、その作用を（ａ）〜（ｅ）に順を追って示す断面説明図である。
【図４】第２実施形態の締結部の防護装置を示す要部の断面図である。
【図５】第２実施形態の別例の締結部の防護装置を示す要部の断面図である。
【図６】第３実施形態の締結部の防護装置を示す断面図である。
【図７】第４実施形態の締結部の防護装置の使用状態を示し、（ａ）はナット部材をナット取外し防止具で覆うときの状態を示す断面図、（ｂ）は前記防止具でナット部材を覆った状態でリング体を螺進方向とその逆方向に回転自由とした状態を示す断面図である。
【図８】第４実施形態の締結部の防護装置に用いるスプリング部材の正面図である。
【図９】第４実施形態の締結部の防護装置におけるスプリング部材の外向き折曲突出部が係入される切欠凹部を示すリング体の部分断面図である。
【図１０】第１参考例の締結部の防護装置を示す断面図である。
【図１１】図１０におけるＡ−Ａ線断面図であって、（ａ）は外側リング体を螺進方向に回転するときの状態を示し、（ｂ）は外側リング体をその逆方向に回転するときの状態を示している。
【図１２】第２参考例の締結部の防護装置を示し、（ａ）はその縦断面図、（ｂ）は要部の構造を示す正面断面図である。
【図１３】第２参考例の締結部の防護装置における要部の部材である止め輪の正面図。
【図１４】第２参考例の締結部の防護装置における要部の部材である支持体の正面図である。
【図１５】第３参考例の締結部の防護装置を示し、（ａ）はその要部の縦断面図、（ｂ）は要部の部材であるスプリング部材の正面図である。
【図１６】本発明の他の適用例を示す断面図である。
【符号の説明】
１、２鉄板
３ボルト部材（ネジ部材）
３ａネジ部
４ナット
５ロックナット
６ナット部材
７、７Ａ、７Ｂ、７Ｃ、７Ｄ、７Ｅナット取外し防止具
７ｂリング体
７ｅ突起部
７ｐ、９０ａキャップ部
８、８Ａスプリング部材
７ｍ切欠凹部
７ｎ環状凹部
８ａ外向き折曲突出部
７ｓ孔部
９、１２、１２Ａ支持体
９ａ、９１、９４環状凹部
１０有端略円状バネ体
１０ａ折曲部
１０ｂ他端
１１係止用突起部
７ｔ内向き鍔部
１２ａ小径部
１２ｂ大径部
１２ｃ係止用切欠凹部
１２ｍ端部
１３止め輪
１３ａ後向き屈曲片
１４突起部
５１係合突起
９０、９３、９３Ａ外側リング体[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a protection device for a fastening part that protects the nut member in a fastening part in which a steel plate or the like in a steel tower or the like is fastened by a screw member and a nut member to prevent the nut member from being removed.
[0002]
[Prior art]
Generally, in order to connect steel plates in a steel tower or the like, a screw member such as a bolt member is inserted into the through holes of both iron plates, a nut is screwed from the tip of the screw member, and a lock nut is screwed to the screw member. Tightened together.
[0003]
However, since the nut and the lock nut are exposed on the surface, there is a situation where the lock nut is loosened by mischief or the like and the nut is removed from the screw member to release the fastening state between the steel plates.
[0004]
[Problems to be solved by the invention]
An object of the present invention is to provide a protection device for a fastening portion that can solve the above-described conventional problems and can reliably prevent the fastening state of the fastening portion from being solved by mischief or the like.
[0005]
[Means for Solving the Problems]
In order to achieve the above-mentioned object, the present invention provides a fastening portion protection device configured to prevent the nut member from being removed at a fastening portion in which the fastening member is fastened by a screw member and a nut member. In a state where the fastening member is fastened by the screw member and the nut member, a coil-shaped spring member having one or more turns is included on the inner surface side of the ring body so as to restrict the axial movement within a predetermined range. A nut removal prevention tool comprising an engaging portion that is detachably engaged with the end portion is provided on the ring body and is rotated in the forward direction while pressing against the end portion of the screw member to thereby move the spring member to the end portion. Is engaged with the engaging portion and is advanced while being screwed to the threaded portion of the screw member, and the nut removal prevention tool is in contact with the nut member or the fastened member and is restricted from moving in the axial direction. in addition the Tsu rotate the door removal preventer in the forward direction is further screwed forward only the spring member, rotating the end of the spring member by disengaging from the engaging portion, the nut removal preventer in opposite directions It is characterized in that the nut member is protected so that the nut removal preventing tool can not be removed.
[0006]
[0007]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of a protection device for a fastening portion according to the present invention will be described with reference to the drawings.
[0008]
FIG. 1 shows a use state of a fastening member protection device according to a first embodiment of the present invention, wherein (a) includes a nut member that is screwed to a bolt member (screw member) and fastens steel plates to each other. Sectional drawing which shows a state when it covers with a nut removal prevention tool, (b) is the state which made the said prevention tool freely rotatable in the screwing direction of a nut member and the reverse direction in the state which covered the nut member with the nut removal prevention tool 2 is a cross-sectional view of the preventer, FIG. 3 is a nut member that is screwed into a bolt member and fastened with iron plates, and is covered with the preventer, and the preventer is screwed in the nut member. It is sectional explanatory drawing which shows the process which reaches the state made free to rotate in the opposite direction.
[0009]
1 (a) and 1 (b), reference numerals 1 and 2 are iron plates used for a steel tower or the like, and these iron plates 1 and 2 are nut members 6 each comprising a bolt member 3, a nut 4 and a lock nut 5. It is concluded. That is, with the opposed surfaces of the iron plates 1 and 2 being in contact with each other, the screw portions 3a of the bolt members 3 are inserted into the bolt insertion holes 1a and 2a of the iron plates 1 and 2, and then the nut 4 is screwed. Further, the lock nut 5 is screwed and tightened to fasten the iron plates 1 and 2 between the head 3 b of the bolt member 3 and the nut member 6.
[0010]
In the protection device for the fastening portion of the first embodiment, the through hole 7a is formed in the central portion of the nut member 6 that is screwed into the screw portion 3a of the bolt member 3 that fastens the iron plates 1 and 2 as described above. In addition, a nut removal prevention tool (hereinafter sometimes referred to simply as a prevention tool) 7 having a ring body 7b integrally formed with a cylindrical cap portion 7p as a main component is covered and covered, as shown in FIG. As shown also, small projecting edges 7c and 7d project from the front and rear edges of the inner surface of the ring body 7b of the preventer 7. The coil-shaped spring member 8 has approximately two turns on the inner surface side of the ring body 7b. Is arranged. The spring member 8 has a natural diameter slightly smaller than the diameter of the screw portion 3a, and is screwed into the screw portion 3a so as to hold it. The spring member 8 is restricted to move in the axial direction within a predetermined range by both small protruding edges 7c and 7d. Further, a protrusion 7e that contacts the rear end of the spring member 8 is provided in the vicinity of the rear edge of the inner surface of the ring body 7b. The protrusion 7e may be formed integrally with the ring body 7b or may be formed by implanting a pin on the ring body 7b.
[0011]
As shown in FIG. 3A, the preventer 7 first covers the nut member 6 screwed into the screw portion 3a of the bolt member 3 in the direction of the arrow so as to cover the cap portion 7p, and then FIG. As shown in (b), when the preventer 7 is pressed and rotated in the screwing direction as shown by the arrow, the spring member 8 is placed on the portion protruding from the lock nut 5 in the threaded portion 3a of the bolt member 3. The threaded portion 3a is screwed in so that it is difficult to be inserted, and the rear end portion of the spring member 8 is pushed by the projection 7e, and is integrated with the ring body 7b having the cap portion 7p in the screwing direction (leftward in the figure). ) And move forward.
[0012]
Further, as shown in FIG. 3 (c), the ring body 7b provided with the cap portion 7p and the spring member 8 are advanced in the screwing direction until the tip of the prevention device 7 comes into close contact with the iron plate 2. When the preventer 7 is further rotated while being in close contact with the iron plate 2, the ring body 7 b provided with the cap portion 7 p is restrained from moving in the screwing direction by the iron plate 2, so that only the rotational force is applied to the spring member 8. As shown in FIG. 3D, only the spring member 8 further advances along the screw portion 3a.
[0013]
By continuing further rotation, as shown in FIG. 3E, the rear end of the spring member 8 is separated from the protrusion 7e. In this state, the ring body 7b provided with the cap portion 7p freely rotates in both forward and reverse directions and idles.
[0014]
As a result, the ring body 7b having the cap portion 7p is restrained from moving in the axial direction because the small protruding edge 7c engages with the spring member 8 fixed so as to be held in the screw portion 3a. Since the body 7b rotates idly in any direction and cannot be retracted, the preventer 7 cannot be removed, and the nut member 6 covered with the preventer 7 is not provided. Can no longer be removed.
[0015]
Therefore, the nut member 6 screwed into the bolt member 3 and fastened between the iron plates 1 and 2 cannot be removed from the bolt member 3 due to mischief or the like, and the fastening state between the iron plates 1 and 2 cannot be released. It is possible to prevent the steel tower from becoming dangerous.
[0016]
FIG. 4 is a cross-sectional view of a main part showing a protection device for a fastening part according to the second embodiment, and FIG. 5 is a cross-sectional view of a main part showing a protection device for a fastening part of another example. In addition, the same code | symbol is attached | subjected and demonstrated to the same member and the same location in the protection apparatus of the fastening part of above-described 1st Embodiment.
[0017]
The protection device for the fastening part of the second embodiment and another example has the same basic configuration as that of the first embodiment, and the action for protection of the fastening part is basically the same. 4 and 5 is that slip spacers 14 and 14A are attached to the lock nut 5 side of the ring body 7b of the nut removal preventing tool 7 as shown in FIGS. The body 7b is surely idle with respect to the spring member 8.
[0018]
That is, in the protective device for the fastening portion of the second embodiment shown in FIG. 4, the annular plate-like sliding spacer 14 is attached to the inner surface of the ring body 7b on the side of the lock nut 5 by the retaining ring 15, and FIG. In the protection device for the fastening portion shown, an annular slip spacer 14A is disposed along an annular projection 7c projecting inwardly on the lock nut 5 side of the inner surface of the screw 7a of the ring body 7b.
[0019]
FIG. 6 shows a protective device for a fastening portion according to the third embodiment. The nut removal preventing tool 7D of the third embodiment does not have a function corresponding to the cap portion 7p of the first embodiment, and does not have a function of covering the nut member 6. However, in the third embodiment as well, the preventer 7D is configured to include the ring body 7b, the small protruding edges 7c and 7d, the spring member 8, and the protrusion 7e similar to those in the first embodiment. As shown in FIG. 4, when the ring body 7b continues to rotate while the front end surface of the ring body 7b is in contact with the lock nut 5, the rear end of the spring member 8 is separated from the protrusion 7e, and the ring body 7b. Will rotate freely in both forward and reverse directions, causing the nut members 5 and 6 to be unremovable. That is, when the nut members 5 and 6 are rotated in the loosening direction, the ring member 7b is brought into contact with the ring body 7b, and a double nut effect is generated in the screw portion 3a. The nut members 5 and 6 cannot be removed.
[0020]
FIG. 7: shows the protection device of the fastening part of 4th Embodiment, (a) is a state when covering the nut member screwed together by a bolt member and fastening steel plates with the nut removal prevention tool provided with the cap part. FIG. 8B is a cross-sectional view showing a state where the nut member is covered with the preventive device and the preventive device is freely rotatable in the screwing direction of the nut member and in the opposite direction. FIG. FIG. 9 is a partial cross-sectional view of the preventer showing a notch recess in which an outward bent protrusion of the spring member is engaged. FIG. In addition, the same code | symbol is attached | subjected to the same member in the above-mentioned 1st Embodiment, and the same location, and description is abbreviate | omitted.
[0021]
In the protection device for a fastening portion according to the fourth embodiment, as shown in FIGS. 7A and 7B, a part of the inner surface of the ring body 7b of the nut removal preventing tool 7A is formed at the end of the spring member 8A. A notch recess 7m into which the outward bent protrusion 8a (see FIG. 8) can be engaged is formed, and the outward bent protrusion 8a of the spring member 8A is continuously formed on the front side of the notch recess 7m. An annular recess 7n is formed in which is rotatably accommodated (see FIG. 9).
[0022]
According to the protection device for the fastening portion of the fourth embodiment, as shown in FIG. 7A, the cap portion 7p of the prevention tool 7A is covered with the nut member 6 composed of the nut 4 and the lock nut 5. In the state, the outward bent protruding portion 8a of the spring member 8A is engaged with the notch recess 7m of the ring body 7b, and the spring member 8A is rotated by rotating the ring body 7b having the cap portion 7p in the screwing direction. It rotates integrally with the ring body 7b.
[0023]
When this ring body 7b is further rotated in the same direction with the ring body 7b provided with the cap portion 7p in close contact with the iron plate 2, as shown in FIGS. 7 (a) and 7 (b), the spring member 8A Since the outward bent protruding portion 8a is engaged with the notch recessed portion 7m, the outward bent protruding portion 8a moves forward along the screw portion 3a in the screwing direction (leftward in the drawing). Will move away from the notch recess 7m to the annular recess 7n.
[0024]
In this state, the ring body 7b provided with the cap portion 7p freely rotates in both forward and reverse directions and idles. As a result, the ring body 7b is restrained from moving in the axial direction when the small protruding edge 7c is engaged with the spring member 8A, and the ring body 7b rotates idle in any direction. The ring body 7b cannot be removed, and the nut member 6 covered with the cap portion 7p cannot be removed.
[0025]
Therefore, the nut member 6 screwed into the bolt member 3 and fastened between the iron plates 1 and 2 cannot be removed from the bolt member 3 due to mischief or the like, and the fastening state between the iron plates 1 and 2 cannot be released. It is possible to prevent the steel tower from becoming dangerous.
[0026]
FIG. 10 is a cross-sectional view showing the protective device for the fastening portion of the first reference example , FIG. 11 is a cross-sectional view taken along line AA in FIG. 10, and (a) rotates the outer ring body in the screwing direction of the nut member. (B) shows a state when the outer ring body is rotated in the opposite direction. In addition, the same code | symbol is attached | subjected to the same member and the same location in the protection device of the fastening part of above-mentioned 1st Embodiment, and description is abbreviate | omitted.
[0027]
In the protection device for the fastening portion of the first reference example , a disc-like support body 9 for screwing the nut removal preventing tool 7B into a portion protruding from the lock nut 5 of the screw portion 3a of the bolt member 3, and the nut 4 The outer ring body 90 is integrally provided with a cylindrical cap portion 90 a that covers the nut member 6 including the lock nut 5. The support body 9 supports the outer ring body 90 in a state where it can rotate and cannot move in the axial direction. Further, between the support body 9 and the outer ring body 90, the rotation in only the screwing direction of the outer ring body 90 is transmitted to the support body 9, and the outer ring body 90 is freely rotated in the reverse direction. A transmission means is provided.
[0028]
As shown in FIGS. 10 and 11, the preventer 7B is disposed at the rear end portion of the outer ring body 90 having an annular recess 91 formed on the inner periphery, and is screwed into the screw portion 3a of the bolt member 3, A support body 9 having an annular recess 9a on the outer periphery, an annular recess 9a of the support body 9 and an annular recess 91 of the outer ring body 90, and a bent portion 10a bent at the outer side of one end are formed on the outer ring body 90. The end-like substantially circular spring body 10 formed so that the other end 10b bends inwardly and the outer ring body 90 in the screwing direction. When rotated, the other end 10b of the end-like substantially circular spring body 10 is locked, so that the end-like substantially circular spring body 10 and the support body 9 rotate together with the outer ring body 90. A locking projection 11 projecting outward from the inner surface of the annular recess 9a. That. In addition, it is good to comprise this protrusion 11 for latching with the pin planted to the support body 9 as shown in the figure, or to form integrally with the support body 9. FIG.
[0029]
In the protection device for the fastening portion of the first reference example , as shown in FIG. 11A, when the outer ring body 90 is rotated in the screwing direction (clockwise in the figure), a substantially circular spring body with ends is provided. Since the other end 10b of the base plate 10 is bent inwardly, the support 9 is locked to the locking protrusion 11 projecting outwardly from the inner surface of the annular recess 9a of the support 9, so that the support 9 is connected to the outer ring body 90. Rotates together. Since the support body 9 is screwed into the screw portion 3 a of the bolt member 3, the support body 9 moves forward integrally with the outer ring body 90.
[0030]
As shown in FIG. 11B, when the outer ring body 90 is rotated in the screwing direction (counterclockwise in the figure), the other end 10b of the substantially circular spring body 10 is engaged with the other end 10b. Since the locking state of the projection 11 is released, the other end 10b of the end-like substantially circular spring body 10 rides on the locking projection 11 and rotates, so that the outer ring body 90 rotates freely and idles. .
[0031]
Since the outer ring body 90 and the support body 9 are constrained from moving in the axial direction by the substantially circular spring body 10 that is interposed between the annular recesses 91 and 9a, the outer ring body 90 is supported. Cannot be removed, and the nut member 6 covered with the cap portion 90a of the outer ring body 90 cannot be removed.
[0032]
Therefore, the nut member 6 screwed into the bolt member 3 and fastened between the iron plates 1 and 2 cannot be removed from the bolt member 3 due to mischief or the like, and the fastening state between the iron plates 1 and 2 cannot be released. It is possible to prevent the steel tower from becoming dangerous.
[0033]
FIG. 12 shows a protective device for a fastening portion of a second reference example , (a) is a longitudinal sectional view thereof, (b) is a front sectional view taken along line BB in (a), and FIG. 13 is a main part member. The figure which shows the front surface of a retaining ring and the side surface of a backward bending piece, FIG. 14 is a front view of the support body which is a member of the principal part. In addition, the same code | symbol is attached | subjected to the same member and the same location in the protection device of the fastening part of above-mentioned 1st Embodiment, and description is abbreviate | omitted.
[0034]
In the protective device for the fastening portion of the second reference example , as shown in FIGS. 12A and 12B, the nut removal preventing tool 7 </ b> C is formed on the portion protruding from the lock nut 5 of the screw portion 3 a of the bolt member 3. It comprises a support body 12 to be screwed together and an outer ring body 93 integrally provided with a cap portion 93a covering the nut member 6 comprising the nut 4 and the lock nut 5.
[0035]
The cylindrical outer ring body 93 has an inward flange 7t at the rear end and an annular recess 94 on the inner surface. The front end of the outer periphery of the support 12 is formed in the small diameter portion 12a and the rear portion is formed in the large diameter portion 12b. A locking notch recess 12c is formed in a part of the large diameter portion 12b. (See FIG. 14). In the annular recess 94 of the outer ring body 93, there is an end ring-shaped retaining ring 13 having a rearward bent piece 13 a (see FIG. 13) that can be engaged with the locking notch 12 c at the tip. Is inserted rotatably. In addition, a projection 14 is formed in the annular recess 94 of the outer ring body 93 so that the rear end of the retaining ring 13 is brought into contact therewith. In addition, as shown in the figure, the protrusion 14 may be formed by a pin implanted in the outer ring body 93 or may be formed by protruding a protrusion integrally with the inner surface of the outer ring body 93.
[0036]
In the protection device for the fastening portion of the second reference example , the large-diameter portion 12b of the support 12 is disposed in a restrained state between the retaining ring 13 and the inward flange portion 7t. The axial position is always the same as the support 12. Then, when the outer ring body 93 is rotated in the screwing direction, the retaining ring 13 is pushed and rotated by the projection 14, and the rearward bent piece 13 a of the retaining ring 13 is engaged with the locking notch recess 12 c of the support body 12. Then, since the support body 12 is rotated in the same direction, the support body 12 rotates integrally with the outer ring body 93. On the contrary, when the outer ring body 93 is rotated in the screwing direction, the rearward bent piece 13a is separated from the notch recess 12c for locking, so that the outer ring body 93 is idle.
[0037]
As a result, the outer ring body 93 can only move forward and cannot move backward, and the nut member 6 covered by the outer ring body 93 cannot be removed.
[0038]
Therefore, the nut member 6 screwed into the bolt member 3 and fastened between the iron plates 1 and 2 cannot be removed from the bolt member 3 due to mischief or the like, and the fastening state between the iron plates 1 and 2 cannot be released. It is possible to prevent the steel tower from becoming dangerous.
[0039]
In the first reference example and the second reference example , the outer ring bodies 7B and 93 are omitted from the cap parts 7p and 93a that cover the nut member 6 as in the ring body 7b of the third embodiment shown in FIG. It can be of the shape.
[0040]
15A and 15B show a protection device for a fastening portion according to a third reference example , wherein FIG. 15A is a longitudinal sectional view thereof, and FIG. 15B is a front view showing a spring member which is a main part member.
[0041]
In the third reference example , the nut removal prevention tool 7E is attached to a support body 12A made of a coiled spring member that is screwed into the screw portion 3a of the bolt member 3, and an end portion 12m of the spring member (support body) 12A. The outer ring body 93 </ b> A is provided with an engagement protrusion 51 that is detachably engaged with the peripheral surface.
[0042]
The coil-shaped spring member 12A is formed in a plurality of winding states so as to be screwed into the threaded portion 3a of the bolt member 3, and its axial movement is caused by small protruding edges 93c and 93d provided on the outer ring body 93A. Is regulated by As shown in FIG. 15B, the rear end 12m of the spring member 12A is deformed radially outward. The end 12m can freely rotate in an annular groove 93n that is recessed in the rear side of the inner surface of the outer ring member 12A. The outer ring member 12A is provided with a pin-shaped engagement protrusion 51 so as to face the annular groove 93n.
[0043]
When the outer ring body 93A is rotated in the screwing direction, that is, when the outer ring body 93A is rotated in the direction of the arrow in FIG. 15B, the engagement protrusion 51 is engaged with the end 12m of the spring member 12A. The spring member 12A is rotated in the circumferential direction. When the other outer ring body 93A is rotated in the direction opposite to the above, the engaging projection 51 only deforms the end 12m of the spring member 12A inward in the radial direction. Without engaging, the spring member 12A remains stationary, and the outer ring body 93A rotates idle. That is, the engagement protrusion 51 functions as a one-way rotation transmission means. As in the first and second reference examples , in the third reference example , the outer ring body 93A can only move forward and cannot move backward. Thus, the nut removal preventing tool 7E cannot be removed, and as a result, the nut member 6 cannot be removed, thus providing a protection device for the fastening portion.
[0044]
The present invention can be configured in various ways other than those shown in the above embodiments. For example, projecting the screw shaft 100 to the head 103b of the bolt member 103 for fastening the iron plate 1, 2 to each other as shown in Figure 16, the nut removal prevention as used in the screw shaft 100 in the first embodiment The tool 7 can be screwed together to protect the head 103b of the bolt member 103. The present invention can also be applied to such a case, and in this case, the screw shaft 100 and the head 103b correspond to a screw member and a nut member, respectively, in the claims.
[0045]
【The invention's effect】
As described above, according to the present invention, it is possible to reliably protect the nut member at the time of fastening in a non-removable state.
[Brief description of the drawings]
FIG. 1 shows a use state of a protection device for a fastening portion according to a first embodiment of the present invention, wherein (a) is a cross-sectional view showing a state when a nut member is covered with a nut removal prevention tool, and (b) is the prevention. It is sectional drawing which shows the state which made the ring body free to rotate in the screwing direction and the reverse direction in the state which covered the nut member with the tool.
FIG. 2 is a cross-sectional view of a nut removal preventing tool in the protective device for a fastening portion according to the first embodiment.
FIGS. 3A and 3B are cross-sectional explanatory views showing the operation in order from (a) to (e) in the protective device for a fastening portion according to the first embodiment; FIGS.
FIG. 4 is a cross-sectional view of a main part showing a protection device for a fastening portion according to a second embodiment.
FIG. 5 is a cross-sectional view of a main part showing a fastening portion protection apparatus according to another example of the second embodiment.
FIG. 6 is a sectional view showing a protection device for a fastening portion according to a third embodiment.
7A and 7B show a usage state of a protection device for a fastening portion according to a fourth embodiment, wherein FIG. 7A is a cross-sectional view showing a state when a nut member is covered with a nut removal prevention tool, and FIG. It is sectional drawing which shows the state which made the ring body freely rotatable in the screwing direction and the reverse direction in the state which covered the member.
FIG. 8 is a front view of a spring member used in the protection device for a fastening portion according to a fourth embodiment.
FIG. 9 is a partial cross-sectional view of a ring body showing a cutout recess into which an outward bent protrusion of a spring member is engaged in a protection device for a fastening portion according to a fourth embodiment.
FIG. 10 is a cross-sectional view showing a protective device for a fastening portion of a first reference example .
11 is a cross-sectional view taken along line AA in FIG. 10, where (a) shows a state when the outer ring body is rotated in the screwing direction, and (b) is a rotation of the outer ring body in the opposite direction. It shows the state when you do.
12A and 12B show a protection device for a fastening portion according to a second reference example , in which FIG. 12A is a longitudinal sectional view thereof, and FIG. 12B is a front sectional view showing a structure of a main portion.
FIG. 13 is a front view of a retaining ring which is a main part member in the fastening portion protection apparatus according to the second reference example ;
FIG. 14 is a front view of a support that is a main member of the protection device for a fastening portion according to a second reference example ;
FIGS. 15A and 15B show a protection device for a fastening portion according to a third reference example , wherein FIG. 15A is a longitudinal sectional view of an essential part thereof, and FIG. 15B is a front view of a spring member that is a member of the essential part.
FIG. 16 is a cross-sectional view showing another application example of the present invention.
[Explanation of symbols]
1, 2 Iron plate 3 Bolt member (screw member)
3a Screw part 4 Nut 5 Lock nut 6 Nut member 7, 7A, 7B, 7C, 7D, 7E Nut removal prevention tool 7b Ring body 7e Projection part 7p, 90a Cap part 8, 8A Spring member 7m Notch recess 7n Annular recess 8a Outside Orientation bending protrusion part 7s Hole part 9, 12, 12A Support body 9a, 91, 94 Annular recessed part 10 Ended substantially circular spring body 10a Bending part 10b Other end 11 Locking projection part 7t Inward flange part 12a Small diameter Portion 12b large-diameter portion 12c locking notch recess 12m end portion 13 retaining ring 13a backward bending piece 14 projection portion 51 engagement projection 90, 93, 93A outer ring body

Claims

A fastening portion protection device configured to prevent removal of the nut member at a fastening portion in which the fastened member is fastened by a screw member and a nut member, wherein the fastened member is fastened by the screw member and the nut member. In this state, a coil-shaped spring member of one or more turns is included on the inner surface side of the ring body so that the axial movement is restricted within a predetermined range, and the engagement is detachably engaged with the end of the spring member. A nut removal prevention device configured by providing a portion on the ring body is rotated in the forward direction while pressing against an end portion of the screw member, and the spring member is engaged with the engagement portion in the state where the end portion is engaged with the engagement portion. The nut removal preventing tool is moved forward while being screwed into the threaded portion of the screw member, and the nut removal preventing tool further rotates in the forward direction while the nut removal preventing tool abuts against the nut member or the fastened member and the movement in the axial direction is restricted. Let Said spring member only by further screwed forward, by disengaging the end portion of the spring member from the engaging portion, the free rotation of the nut removal preventer in both forward and reverse directions, impossible remove the nut removal preventer state A fastening device protection device characterized in that the nut member is protected as follows.

The protection device for a fastening portion according to claim 1, wherein the ring body is integrally provided with a cylindrical cap portion that covers the nut member.

3. The fastening portion protection device according to claim 1, wherein the engaging portion is configured by a protruding portion that protrudes inward from an inner surface of the ring body and abuts against a rear end of the spring member. .

The engaging portion is composed of a notch recess formed in the inner surface of the ring body and an annular recess continuously located on the front side of the notch recess, and is outwardly bent at the end of the spring member. The spring member rotates integrally with the ring body when the projecting portion is engaged in the notch recess, and the ring body when the outward bent projecting portion of the spring member is located in the annular recess. The device for protecting a fastening portion according to claim 1 or 2, characterized in that is configured to be freely rotatable in both forward and reverse directions.