JP2005036390A

JP2005036390A - Drilling bit, self-drilling rock bolt using the same, and construction method for self-drilling rock bolt

Info

Publication number: JP2005036390A
Application number: JP2003177399A
Authority: JP
Inventors: Kazuo Kiuchi; 和夫木内; Kazunori Maeda; 和徳前田; Yoshijiro Furuya; 義二郎古屋
Original assignee: DAIYONKI CHISHITU KENKYUSHO KK; Okabe Co Ltd
Current assignee: DAIYONKI CHISHITU KENKYUSHO KK; Okabe Co Ltd
Priority date: 2003-05-19
Filing date: 2003-06-23
Publication date: 2005-02-10
Anticipated expiration: 2023-06-23
Also published as: JP4475497B2

Abstract

<P>PROBLEM TO BE SOLVED: To provide a drilling bit which is suitable for a drilling method concurrently using an outer pipe, which dispenses with the enlargement of drilling diameter by virtue of good straight advance properties even in usage like that and which can also be applied to a small-size drilling machine with low running torque, a self-drilling rock bolt using the drilling bit, and a construction method for the self-drilling rock bolt. <P>SOLUTION: A groove 15, which continues from a leading end side to a back end side, is formed in the outer peripheral surface of the drilling bit 1, and a through-hole 19, which communicates with an internal space part of a bit body 2, is opened in the groove 15. A hollow rod 2, whose tip is fitted with the drilling bit 1, drills a hole in the state of being enclosed with the outer pipes 5 and 51. A pressurized fluid, which is supplied from the drilling machine 42, passes through the inside of the hollow rod 2 so as to be ejected to the tip side of the drilling bit 1, passes through the groove 15 along with cuttings cut away there, so as to move backward through the inside of the outer pipes 5 and 51, and is discharged from an opening 72 of an adaptor 7. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は、例えば削孔機の回転ロッドや自穿孔ロックボルトの先端に装着される穿孔ビットと、この穿孔ビットを中空ロッドの先端部分に装着した自穿孔ロックボルト、並びにこの自穿孔ロックボルトの施工方法に関するものである。
【０００２】
【従来の技術】
従来、タングステンカーバイトなどの超硬合金からなる複数のチップ（刃体）をビット本体の前端面に植設してなる穿孔ビットは、削孔機の回転ロッドあるいは自穿孔ロックボルトとしてロックボルト本体の先端部分に装着され、地盤の掘削などに使用されている。ところで、例えば樹木が生い茂るような柔らかい表土の地山や砂質の地山では、穿孔しながら掘削土砂（繰り粉）を外部に排出しても孔壁が崩れやすく、掘削孔が自立しにくい場合が多々ある。このような施工条件では、自穿孔ロックボルトが一般的に適用されているが、掘削孔の崩れにより繰り粉の排出が行われなくなると、それ以上の穿孔は困難である。また、自穿孔ロックボルトが周囲の地山から締め付けられることになり、削孔機の回転トルクが不足することにもつながる。しかも、何とか削孔できたとしても、掘削孔の内部が部分的に土砂で閉塞された状態になっていることが多いことから、セメントミルク等の定着材（グラウト材）の注入が妨げられ、ロックボルトの定着不良や被り厚不足が生じやすい。
【０００３】
このため、崩壊性地盤にロックボルトを設置する方法として、従来知られている二重管削孔方式を自穿孔ロックボルトに応用したものが提案されている（例えば、特許文献１、２参照）。すなわち、先端に穿孔ビットが装着された自穿孔ロックボルトに対して、穿孔ビットが端部から突出するように鋼管等の外管で覆い、内側の自穿孔ロックボルトに回転と打撃を与えて削孔した後、自穿孔ロックボルトの中空部あるいはその外周面と外管内周面との間を通じてセメントミルク等を注入しながら、もしくは注入後に外管を抜き取り、自穿孔ロックボルトを掘削孔内に定着するものである。
【０００４】
【特許文献１】
特開２００２−３８８６５号公報（公報第３頁第５欄第３７行−第４頁第８欄第２９行、図１−図３）
【特許文献２】
特開２００２−１２９８９９号公報（公報第３頁第３欄第２１行−第４頁第５欄第４２行、図１）
【０００５】
【発明が解決しようとする課題】
上記特許文献１に記載のものでは、自穿孔ロックボルトの先端側において、穿孔ビット基部の外周面と外管端部の内周面との間に比較的大きな隙間が存在し、当該部分では互いに拘束しない構造である。この隙間は、自穿孔ロックボルト先端の偏芯型の穿孔ビットが外管内を通過できるように設定され、削孔に伴う削り屑（繰り粉）も外管の内側を通って外部に排出されるようになっている。このため、長尺になるほど両者の間で芯ブレが生じ、偏芯ビットの使用と合わせて掘削孔の直進性を低下させる一因になっている。したがって、直進性の悪い掘削孔に外管が自穿孔ロックボルトとともに挿入されるには、それを考慮して比較的大きめの穿孔ビットを用いて削孔を行う必要があり、コスト面や施工性の面で改善の余地が残されている。
【０００６】
また、特許文献２に記載のものは、外管を自穿孔ロックボルトとともに回転させる構造であるから、前者のような芯ブレは生じない。しかしながら、この場合には孔壁に対する接触面積が増大することから、摩擦抵抗も大きくなり、回転トルクの大きな大型の削孔機が必要となる。さらに、孔壁が崩れたり、孔曲りが生じた場合には、摩擦抵抗が一段と増加する。削孔深度が深くなるにつれて、この傾向は顕著に表れる。したがって、このものは、レッグハンマー等の手持ち用の小型削孔機に適用できないという大きな問題がある。
【０００７】
本発明は、これら従来技術の問題点に鑑みなされたもので、外管を併用する削孔方法に最適であって、そのような場合でも削孔径が必要以上に大きくならず、しかも回転トルクの小さい小型の削孔機にも適用可能な穿孔ビットと、それを用いた自穿孔ロックボルト、及び自穿孔ロックボルトの施工方法の提供をその目的とする。
【０００８】
【課題を解決するための手段】
上記課題を解決するため、本願の請求項１に係る発明では、先端側にチップが植設されたビット本体の後端側に開口する内空部と、この内空部に連通してビット本体の一部に開口する通孔とを備え、内空部に一端側が嵌合して連結される中空ロッドの他端側から供給された加圧流体を当該通孔から噴出させながら削孔を行う穿孔ビットにおいて、前記ビット本体は、後端側部分が段差部を挟んで先端側部分よりも小径に形成され、それら外周面には先端側に噴出された加圧流体を後端側に導く両端に連続した流路を備えることを特徴としている。
【０００９】
この発明による穿孔ビットでは、ビット本体の外周面に軸心と平行な溝などの両端側に連続する流路が設けられ、削孔時においてビット本体の先端側に噴出された加圧流体は、流路を通過して後端側に導かれるようになっている。このような構成により、本発明に係る穿孔ビットは、例えば掘削孔が自立しにくい地山での削孔など、ロックボルトあるいは削孔機に適用し、それらの中空ロッド（ロックボルト本体、回転ロッド等）を鋼管等の外管で包囲した状態で削孔を行う場合に好適である。すなわち、それら穿孔ビットを先端に有する中空ロッドに対して、チップが植設されている穿孔ビットの先端側部分を残して外管を被せた状態で削孔を行ったときには、ビット本体の先端側においてチップにより削られた繰り粉が、噴出した加圧流体とともにビット本体外周面に存在する前記流路を通過するようになっている。ここで、外管の内周面とビット本体の外周面との隙間が僅かであっても、繰り粉は前記流路を通り抜けて確実に後方に移動して外部に排出される。なお、地山の状況、適用した外管の外径と穿孔ビット外径の比率等によっては、前記流路を介した外管の内側からの排出に加え、外管の外側も排出路となる。
【００１０】
このように、ビット本体の後端側部分の外径に近い内径の外管を併用した場合は、ビット本体の段差部より後端側ではビット本体と外管とがほぼ嵌合状態となり、回転する中空ロッドが実質的に先端側でも保持されることから、削孔時において両者は常に同軸状態に維持されて芯ブレが低減し、従来の非拘束状態のものに比べて直進性が向上する。このため、削孔径は外管の外径に近いものでよいから、穿孔ビットの外径を必要最低限にすることができ、削孔作業の合理化に大きく寄与する。
【００１１】
請求項２に係る穿孔ビットは、上記請求項１に係る発明において、複数の流路がビット本体の周方向に等間隔で且つ軸心と平行に設けられたことを特徴とするものである。この場合には、繰り粉が各流路に分散し、且つ最短距離で流路を通過するので、排出をより効率的に行うことができる。
【００１２】
請求項３に係る穿孔ビットは、上記請求項１に係る発明において、ビット本体の後端側部分の外周面が、後方に向けて縮径するテーパ面に形成されていることを特徴とするものである。この場合、ビット本体の後端側部分では段差部に最も近い部位が最大径となり、その寸法を適用する外管の内径に近いものとすれば、嵌合状態での両者の隙間が一段と減少するので、削孔時における芯ブレの低減につながり、直進性はより向上する。さらに、後端側部分の外経が軸心方向に一定のものに比べて外管内面とビット本体外面の間の摩擦が少なくなるから、回転トルクの小さな削孔機にも適用が可能である。
【００１３】
請求項４に係る穿孔ビットは、上記請求項１に係る発明において、通孔が流路に開口していることを特徴とするものである。この場合には、流路以外の部分は自由に利用できるから、チップ形状やその配置状態の制約が少ないという利点がある。
【００１４】
また、請求項５に係る発明は、先端側にチップが植設されたビット本体の後端側に内空部が開口し、当該内空部に連通してビット本体の一部に通孔が開口する穿孔ビットと、この穿孔ビットの内空部に一端側が嵌合して連結される中空ロッドからなり、当該中空ロッドの他端側から供給された加圧流体を穿孔ビットの通孔から噴出させながら削孔を行う自穿孔ロックボルトにおいて、前記ビット本体は、後端側部分が段差部を挟んで先端側部分よりも小径に形成され、それら外周面には先端側に噴出された加圧流体を後端側に導く両端に連続した流路を備えることを特徴としている。
【００１５】
すなわち、上記自穿孔ロックボルトは、請求項１に係る穿孔ビットが中空ロッドの先端に装着された構成であるから、そのまま単独での使用は無論のこと、外管を被せて削孔を行うのに特に好適である。外管を併用するような使用形態であっても、繰り粉はビット本体の側面を通過して外管内を後方に向けて移動するか、あるいは外管内に加えて外管の外側も排出路となり、確実に外部に排出される。さらに、この自穿孔ロックボルトを使用すれば、削孔径が小さくて済み、直進性にも優れることは同様である。
【００１６】
さらに、請求項６に係る発明は、上記請求項５に係る自穿孔ロックボルトの施工方法であって、先端側にチップが植設されたビット本体の後端側に内空部が開口し、当該内空部に連通してビット本体の一部に通孔が開口する穿孔ビットと、この穿孔ビットの内空部に一端側が嵌合して連結される中空ロッドからなり、前記ビット本体の後端側部分が段差部を挟んで先端側部分よりも小径に形成され、それら外周面には先端側に噴出された加圧流体を後端側に導く両端に連続した流路を備える自穿孔ロックボルトに、前記先端側部分を残して外管を遊挿するとともに当該中空ロッドの他端側においてアダプタを介して削孔機に連結し、前記外管が前記穿孔ビットの段差部と前記アダプタとの間に中空ロッドに対して空転可能に保持された状態で、中空ロッドの他端側から供給された加圧流体を穿孔ビットの通孔から噴出させ、先端側に噴出された加圧流体を繰り粉とともに少なくとも穿孔ビットの流路を介して外管内を通過させて外部に排出しながら削孔を行った後、中空ロッドを介して定着材を注入するとともに外管を除去し、孔壁内面との間に充填された定着材により自穿孔ロックボルトを定着させることを特徴とするものである。
【００１７】
この施工方法によれば、自穿孔ロックボルトが外管により包囲された状態で削孔を行うので、孔壁が崩れやすい地山でも確実に削孔することが可能である。また、実質的に外管を回転させずに削孔するものであるから、従来のように回転する外管が孔壁に接触することで発生する摩擦抵抗を最小限に抑えられる。したがって、回転トルクの小さい小型の削孔機の使用が可能になる。さらに、上記請求項５に係る構成の自穿孔ロックボルトの使用により、外管に包囲された状態でも繰り粉が少なくとも外管の内側を通って確実に外部に排出され、外管内での芯ブレも大幅に低減することができる。このため、直進性が向上して外管の挿入が妨げられることがないので、削孔径については、使用する外管の外径に合わせた必要最低限の寸法とすることにより、削孔作業が大幅に合理化される。しかも、自穿孔ロックボルトと外管とは実質的に同軸上に配置され、自穿孔ロックボルトは掘削孔の軸心に位置した状態でその周囲にほぼ同じ厚さで定着材が充填されるから、十分な被り厚を確保することができ、定着力も安定する。なお、地山の状況、適用した外管の外径と穿孔ビット外径の比率等によっては、前記流路を介した外管の内側からの排出に加え、外管の外側も排出路となる。
【００１８】
そして、請求項７に係る施工方法は、先端側にチップが植設されたビット本体の後端側に内空部が開口し、当該内空部に連通してビット本体の一部に通孔が開口する穿孔ビットと、この穿孔ビットの内空部に一端側が嵌合して連結される中空ロッドからなり、前記ビット本体の後端側部分が段差部を挟んで先端側部分よりも小径に形成され、それら外周面には先端側に噴出された加圧流体を後端側に導く両端に連続した流路を備える自穿孔ロックボルトに、前記先端側部分を残して外管を遊挿するとともに当該中空ロッドの他端側においてアダプタを介して削孔機に連結し、前記外管が前記穿孔ビットの段差部と前記アダプタとの間に中空ロッドに対して空転可能に保持された状態で、中空ロッドの他端側から供給された加圧流体を穿孔ビットの通孔から噴出させ、先端側に噴出された加圧流体を繰り粉とともに少なくとも穿孔ビットの流路を介して外管内を通過させて外部に排出しながら削孔を行った後、外管に代えてコルゲートシース管を挿入するとともに中空ロッドを介して定着材を注入し、前記コルゲートシース管の内外に充填された定着材により自穿孔ロックボルトを定着させることを特徴としている。
【００１９】
すなわち、この施工方法と上記請求項６に係る施工方法との違いは、削孔終了後において、外管に代えてコルゲートシース管を挿入し、その内外に定着材を充填する点にある。これにより、外管を直ちに引き抜いて他の場所の削孔作業に供することができる。なお、セメントミルク等の硬化性定着材の注入作業は、一度に多数個所の充填を行うほうが好都合なので、この点からも施工作業全体の効率化につながる。
【００２０】
【発明の実施の形態】
本発明に係る穿孔ビット及びこれを用いた自穿孔ロックボルトは、ビット本体の外周面に先端側から後端側に連続する流路を設け、この流路を先端側で発生する繰り粉の排出路として活用することを技術的特徴としている。これにより、例えば掘削孔が自立しないような地山において、外管を自穿孔ロックボルトに被せて削孔する場合でも効率よく行うことができ、直進性の向上に伴い、削孔径を小さくすることができる。
【００２１】
なお、穿孔ビットにおける超硬チップの形状としては、例えば最先端部分を平面とした二段円錐状、半球状、最先端部分のみを丸めたテーパ状、最先端部分を平面とした角錐状などのボタンビットタイプ、あるいはクロスビットタイプ等、その形状に格段の限定はなく、使用条件等に応じて適宜選定される。また、本発明の各請求項に係る穿孔ビットは自穿孔ロックボルトに限らず、削孔ロッドに本発明の穿孔ビットを取り付けて削孔を行った後、穿孔ビットおよび削孔ロッドを引き抜き、改めてロックボルトを挿入するプレボーリング方式にも適用することができる。さらに、この自穿孔ロックボルトは、削孔時に外管を併用しない単独での使用ももちろん可能である。
【００２２】
【実施例】
以下、本発明の実施例について、添付図面を参照しながら詳細に説明する。図１ないし図３は、本発明に係る穿孔ビットの一実施例を示すもので、それぞれ正面図、平面図および断面図である。図示の穿孔ビット１は、有底筒状に鋳造されたビット本体１０と、その先端面に植設された超硬合金からなる略ボタン状で同一サイズの６個のチップ１１ａ，１１ｂ，１１ｃ，１１ｄ，１１ｅ，１１ｆから構成されている。
【００２３】
上記ビット本体１０は、６個のチップ１１ａ〜１１ｆが植設されている先端側部分１２に対して、後端側部分１３が段差部１４を挟んで小径に形成されている。そして、それらの外周面には、周方向に等間隔で軸心と平行な６個の溝１５が、繰り粉等の流路として、先端側部分１２と後端側部分１３に跨って外周面の全長に渡って設けられている。一方、その内部は図３から明らかなように、内空部１６の内面に後端側の開口部から先端面側に向けて約半分の長さでロープねじ１７が形成されている。このロープねじ１７の先端側には、それよりも小径の凹部１８が設けられ、この凹部１８から軸心に対し斜め前方に向けて２個の通孔１９が壁面を貫通し、先端側部分１２の溝１５に開口している。これら２個の通孔１９は、軸心を挟む対向位置に設けられている。なお、ビット本体１０の後端側部分１３は、実施例ではその全長が同じ外径となっているが、後方に向けて縮径するテーパ面に形成すると、後述する外管との嵌合において好都合である。
【００２４】
そして、図２から明らかように、上記６個のチップのチップ１１ａ〜１１ｆは、前端面の中央に形成された平坦部１２ａの中心すなわちビット本体２の軸心から少し外れた位置にチップ１１ａが植設され、その他のチップ１１ｂ〜１１ｅは、斜面部１２ｂにおいて、ビット本体１０の軸心から右回りに順次離れるように植設され、最外周に位置するチップ１１ｅの軸心を挟む対向位置にチップ１１ｆが設けられている。これにより、各チップ１１ａ〜１１ｅの先端部分の位置は、ビット本体１０の後端面方向に順次後退し、最外周のみ２個のチップ１１ｅ，１１ｆの軌跡が重なることになる。実施例では、６個のチップ１１ａ〜１１ｆが、右回りの螺旋状に配置されているが、この向きは穿孔ビット１の回転方向と同じである。したがって、穿孔ビット１を左回転の削孔機に適用する場合には、各チップの配置は左回りにする必要がある。このように、各チップ１１ａ〜１１ｆが、穿孔ビット１の回転方向と同じ方向の螺旋配置されることから、少ないチップ数でも円滑な回転が行われる。また、隣り合うチップ間においてそれぞれの先端位置に軸心方向の段差が形成されることにより、特に木の根が存在するような場所で削孔する際に、確実に根を切断して削孔を行うことができる。
【００２５】
なお、上記実施例では最外周位置にのみ同じ軌跡を描く２個のチップ１１ｅ，１１ｆが設けられている。このような配列は、削孔時に最も仕事量が多く負担のかかる最外周部分に複数のチップが存在することにより、その内方に植設された内側チップ群１１ａ〜１１ｄの螺旋状配列に基づくコストダウン効果（チップ数の低減）を維持しながら、穿孔ビットの大口径化に適している。また、平坦部１２ａに設けられたチップ１１ａ以外の５個のチップ１１ｂ〜１１ｆは、すべて斜面部１２ｂに対してそれぞれの軸心が略直角となるように植設されている。すなわち、ビット本体１０の軸心に対して５個のチップが外側に傾斜した状態で回転するため、傾いた分だけ軌跡が増加し、小径のチップであっても大きな仕事量が得られる。そして、最外周に位置する２個のチップ１１ｅ，１１ｆについては、斜面部１２ｂの外周縁にごく近い場所に植設されていることから、ビット本体１０の最大径部よりもやや外側に突出した状態になる。これらチップ１１ｅ，１１ｆの存在により、削孔時においてビット本体１０の先端側部分１２の外周面が、削孔中に孔壁に接触しにくくなるので、穿孔ビット１の回転が円滑になり、能力の小さな削孔機を使用することができる。
【００２６】
図４は、上記穿孔ビット１を中空ロッド２の端部に装着してなる自穿孔ロックボルト３を削孔装置４に取り付けた状態を示している。ここで使用する削孔装置４は、特願２００２−３２３０８７として本出願人が出願したもので、井桁状の支持フレーム４０に対して摺動自在に取り付けられた移動体４１に削孔機４２が結合され、当該支持フレーム４０に案内されて進退するようになっている。なお、移動体４１は駆動体４３を備え、支持フレーム４０の長手方向に配設されたチェーン４４に掛合し、それをガイドとして移動する。また、中空ロッド２はその外周面の全長に渡りロープねじが形成されたもので、穿孔ビット１のビット本体１０の内空部１６に形成されたロープねじ１７との螺合により結合される。そして、一端側に保護スリーブ６が螺入された鋼管等の外管５を、保護スリーブ６が後方側に位置する向きで自穿孔ロックボルト３に外嵌する。ここで、外管５の他端側が穿孔ビット１の後端側部分１３に嵌合し、保護スリーブ６の反対側の端部がアダプタ７の端面に設けられた円形凹部に嵌合した状態で、自穿孔ロックボルト３は削孔機４２のロッド結合部４２ａに螺入される。なお、ロッド結合部４２ａは、内面に雌ねじ部が形成されるとともに外面に雄ねじ部４２ｂが形成され、さらに雄ねじ部４２ｂの先端側にねじ無し部４２ｃが設けられている。アダプタ７は、このねじ無し部４２ｃに対して、外管５と穿孔ビット１との関係と同様に嵌合状態にあるが、自穿孔ロックボルト３の回転に際して非回転部分との間で大きな摩擦が発生せず、且つ芯ブレが生じないような適度の間隙をもって嵌合するのが望ましい。
【００２７】
図５および図６は、それぞれ外管５と保護スリーブ６の部分断面図である。図５において、外管５は、自穿孔ロックボルト３におけるビット本体１０の後端側部分１３の外径よりも僅かに大きい内径であり、一方の端部の内面には、後述する保護スリーブ６との結合に供される雌ねじ部５ａが形成されている。保護スリーブ６は、図６から明らかなように、一端側に外管５の雌ねじ部５ａと螺合可能な雄ねじ部６ａが形成され、中間の大径部６ｂに続く他端側が小径部６ｃとなっている。なお、大径部６ｂには、軸心を挟む対向位置にスパナ掛けのための平坦部６ｄが２個設けられている。この保護スリーブ６は、後述するアダプタ７に対して外管５の雌ねじ部５ａ側を直接嵌合させると、削孔中に肉厚の薄い雌ねじ部５ａが変形しやすいことから、これを保護するために使用するものである。
【００２８】
図７および図８は、アダプタ７の正面図と平面図であり、周壁７１には両端部を残して開口部７２がそのほぼ半周分の長さで設けられている。そして、両端の環状部分の端面には、図９から明らかなように、それぞれ保護スリーブ６と削孔機４２のねじ無し部４２ｃに嵌合する円形凹部７３，７４が形成されている。
【００２９】
次に、自穿孔ロックボルト３の施工方法について説明する。まず、図９に示すように、自穿孔ロックボルト３に対して、外管５をその端部が穿孔ビット１の後端側部分１３に嵌合する位置まで挿入し、外管５の他端側の雌ねじ部５ａに保護スリーブ６を螺合させる。続いて、アダプタ７を自穿孔ロックボルト３の突出部分に挿入し、その一端側に設けられている円形凹部７３を保護スリーブ６の小径部６ｃに嵌合する。そして、図１０に示すように、自穿孔ロックボルト３の中空ロッド２の他端側を削孔機４２のロッド結合部４２ａに螺入しながら、保護スリーブ６の反対側に設けられている円形凹部７４をロッド結合部４２ａのねじ無し部４２ｃに嵌合することにより、装着が完了する。このようにして自穿孔ロックボルト３が取り付けられた削孔装置４は、その支持フレーム４０を地山Ｇに宛がい、削孔機４２に連結されたコンプレッサー（図示せず）によりエアー等の加圧流体を自穿孔ロックボルト３に供給しながら削孔機４２を駆動し、その回転および打撃力により地山Ｇを掘削して外管５の端部が残る程度の深さまで削孔を行う。
【００３０】
１本分の中空ロッド２の削孔が終わると、図１１に示すように、アダプタ７の開口部７２にパイプレンチ等の工具（図示せず）を差し込んで中空ロッド２を逆方向に回転させ、自穿孔ロックボルト３を削孔機４２から取り外す。次に、図１２に示すように、アダプタ７を抜き取り、保護スリーブ６を外管５から外す。続いて、図１３に示すように、カプラー２０を介して別の中空ロッド２を継ぎ足し、さらに図１４に示すように、延長用外管５１を挿入する。この延長用外管５１は、一端側に雌ねじ部５１ａが形成され、他端側には雄ねじ部５１ｂが形成されたものである。そして、１本目と同様に保護スリーブ６およびアダプタ７を装着して削孔機４２に再結合して削孔を続ける。これらの作業を繰り返して所定の深さに到達するまで削孔を行う。
【００３１】
図１５は、削孔中に発生する繰り粉の排出状態を示している。すなわち、中空ロッド２の内部に供給された加圧流体は、穿孔ビット１の通孔１９から前方に噴出し、チップ１１ａ〜１１ｆで削られた繰り粉とともにビット本体１０の側面に設けられた溝１５を通過し、外管５の内面と中空ロッド２の外面との隙間Ｓ１を移動する。そして、繰り粉と加圧流体は、外管５の端部に取り付けられた保護スリーブ６も通過し、アダプタ７の開口部７２から外部に排出される。この場合、ビット本体１０の後端側部分１３に対して外管５が僅かな間隙で嵌合していても、両者の間には溝１５が存在することにより、繰り粉は確実に後方に移動して外部に排出される。このように、外管５がビット本体１０に僅かな間隙で嵌合しているから、穿孔ビット１の振れを有効に阻止しながら真直状態で穿孔することができる。このため、外管５の外径に近い穿孔ビット１の使用が可能になり、必要最低限の内径の孔を掘削すればよいので、削孔作業の合理化につながる。さらに、削孔時に外管５を回転するものではないから、比較的小さな回転トルクの削孔機を適用することができる。なお、本実施例では複数本の中空ロッド２および外管５，５１を継ぎ足しながら削孔する事例について説明したが、もちろん削孔深さによっては継ぎ足すことなく１本のみを対象としてもよい。また、例えば柔らかい表層部分については外管５を併用し、その下部の硬い地層部分には外管５等を挿入しない施工も可能である。
【００３２】
図１６は、保護スリーブの別の実施例である。図示の保護スリーブ６０は、前記実施例で用いた保護スリーブ６が外管５，５１との結合手段として雄ねじ部６ａが使用されるのに対して、雌ねじ部６０ａが設けられたものである。この保護スリーブ６０を使用すれば、外管５，５１との結合部分において、内面側に突出することはないので、中空ロッド２の外周面との間隙が他の部分と同じに確保され、繰り粉の排出性はさらに向上する。この場合には、外管５の一端側に設けるねじを雄ねじ部とするとともに、延長用の外管５１を前記実施例とは逆に連結し、内面に雌ねじが設けられている適宜のカプラーなどを介して削孔機４２に結合すればよい。
【００３３】
図１７および図１８は、繰り粉の排出経路が異なる実施例について示している。このような状況は、例えば外管５の外径よりもビット本体１０における先端側部分１２の外径が大き目で、外管５の周囲にある程度の隙間が形成される場合に生じる。すなわち、中空ロッド２の内部に供給された加圧流体は、穿孔ビット１の通孔１９から前方に噴出し、チップ１１ａ〜１１ｆで削られた繰り粉とともにビット本体１０の側面に設けられた溝１５を通過し、外管５の内面と中空ロッド２の外面との隙間Ｓ１を移動する経路と、外管５の外側の隙間Ｓ２を通過する経路とに別れる。そして、繰り粉と加圧流体は、外管５の端部に取り付けられた保護スリーブ６も通過し、アダプタ７の開口部７２から外部に排出されるとともに、地山Ｇの開口部からも排出されることになる。
【００３４】
ところで、繰り粉が上記のように外管５の外側の隙間Ｓ２を通過する場合において、地山Ｇが自立しなかったり、あるいは掘削孔の一部が崩れるような状況下では、隙間Ｓ２が部分的に閉塞される虞がある。このような場合には、繰り粉が隙間Ｓ２の途中で詰まりやすく、後述する定着作業に悪影響を及ぼす可能性がある。すなわち、閉塞部分よりも先端側では、外管５の外側に繰り粉が滞留し、外管５を引き抜いた後の掘削孔の内面に繰り粉の薄層が形成される。一方、セメントミルク等の定着材は、一般に粘性が高く浸透性は必ずしも良好とは言えない。このため、斯かる繰り粉の薄層が存在した場合には、その裏側（地山Ｇ）に定着材が十分に浸透せず、定着力低下の原因となる。したがって、削孔中あるいは削孔後に外管５の外側の隙間Ｓ２を清掃することが望ましい。
【００３５】
図１９および図２０は、孔内の清掃方法を示している。まず、削孔機４２から中空ロッド２とアダプタ７を外す。次に、後述する定着作業において用いる引抜き用アダプタ８Ｂの雄ねじ部を外管５１に螺合して連結するとともに、その他端側に形成された雌ねじ部を介して削孔機４２に結合する。そして、削孔機４２から加圧空気を送り込むと、加圧空気は外管５１，５と中空ロッド２の隙間Ｓ１および中空ロッド２の内部を通過し、それぞれがビット本体１０の側面に設けられた溝１５と通孔１９から前方に噴出する。噴出した加圧空気は、外管５，５１の外側の隙間Ｓ２を通過することにより、掘削孔の内面に残っている繰り粉を確実に外部に排出することができる。
【００３６】
図２１および図２２は、外管の異なる実施例を示している。この外管５５は、先端側に６個の切欠５５ａが形成されたものである。この場合、切欠５５ａは周方向に６０度間隔で設けられ、穿孔ビット１の側面に設けられた溝１５に対向するようになっている。このような切欠５５ａを設ければ、削られた繰り粉が外管５５の内部に入る際に入り口を大きく確保できることから、繰り粉の排出がより良好となり、特に粘土質の地山などに適用するのに好適である。なお、図２３に示す穿孔ビット１００のように、側面に設ける溝１０１の数を少なくする代わりに個々の幅を大きくすることも繰り粉の排出を促進する上では有効な手段である。
【００３７】
次に、図２４ないし図２６は、削孔が終了した後の定着作業を示している。削孔が完了したら、上記のような方法で孔内を清掃した後、図２４に示すように、削孔機から外した中空ロッド２の端部に注入用アダプタ８Ａを取り付け、セメントミルク等の定着材を注入する。定着材の流れは加圧流体と同じであり、中空ロッド２の内部を通って先端の穿孔ビット１の通孔１９から前方に噴出され、ビット本体１０の側面に設けられた溝１５を通過し、外管５の内面と中空ロッド２の外面との隙間Ｓ１、および掘削孔の内面と外管５の外面との隙間Ｓ２をそれぞれ流れる。そして、外部側に配置された外管５１の端部の内外から溢れ出るのを確認する。なお、外管５１の外側の隙間Ｓ２がごく少ない場合には、外管５１の内側からの溢れ出しで確認すればよい。
【００３８】
次に、図２５に示すように、外管５１の端部の雌ねじ部５１ａに引抜き用アダプタ８Ｂの雄ねじ部を螺合して連結するとともに、その他端側に形成された雌ねじ部を介して削孔機４２に結合する。この状態で削孔機４２を後退させることにより、外管５，５１をすべて引き抜くことができる。外管５，５１を引き抜いた後、定着材の表面が沈下した場合には、追加注入を行う。そして、図２６に示すように、地山Ｇから突出する自穿孔ロックボルト１の端部に座板９Ａを挿通し、締結ナット９Ｂにより締め付けることにより、定着作業が完了する。
【００３９】
図２７と図２８は、施工方法の他の実施例である。この場合、削孔作業が完了した後、図２７に示すように、外管５，５１の内部に適宜の素材からなるコルゲートシース管５Ａを挿入する。そして、図２８に示すように、外管５１等を引き抜き、その後は前記実施例における図２４以降に示す工程に準じて定着作業を行うことになる。すなわち、コルゲートシース管５Ａはそのまま残置され、定着材がコルゲートシース管５Ａの内外に充填されることになる。この施工方法によれば、外管５，５１を削孔終了後に直ちに引き抜いて次の場所に適用することを繰り返せば、定着材の注入作業をまとめて行うことができるので作業性の向上につながる。
【００４０】
上記実施例の自穿孔ロックボルト１において、中空ロッド２には全ねじボルトが適用されているが、もちろんこれに限定されるものではなく、端部のみをねじ状としたものであっても何ら問題はない。また、穿孔ビット自体についてもビット本体の形状、チップの形状とその数、通孔の位置の変更などは可能である。すなわち、自穿孔ロックボルトとしての使用か、あるいは削孔機への適用など、その使用条件等に応じてこれらを適宜選択すればよく、この発明の技術思想内での種々の変更実施はもちろん可能である。
【００４１】
【発明の効果】
以上説明したように、本発明に係る穿孔ビット及びこれを用いた自穿孔ロックボルト並びにその施工方法は、ビット本体の外周面に先端側から後端側に連続する流路を設け、この流路を先端側で発生する繰り粉の排出路として活用することにより、例えば掘削孔が自立しないような地山において、外管を自穿孔ロックボルトに被せて削孔する場合でも効率よく行うことができ、直進性も大幅に向上するので、削孔径を外管に合わせた必要最低限にすることができる。しかも、回転トルクの小さい削孔機も使用できるなど、その実用上の効果はきわめて大である。
【図面の簡単な説明】
【図１】本発明による穿孔ビットの一例を示す正面図である。
【図２】上記穿孔ビットの平面図である。
【図３】上記穿孔ビットの断面図である。
【図４】上記穿孔ビットが装着された自穿孔ロックボルトを削孔装置に取り付けた状態を示す説明図である。
【図５】本発明の施工方法で使用する外管の部分断面図である。
【図６】本発明の施工方法で使用する保護スリーブの部分断面図である。
【図７】本発明の施工方法で使用するアダプタの正面図である。
【図８】上記アダプタの平面図である。
【図９】上記保護スリーブおよびアダプタの装着方法を示す説明図である。
【図１０】削孔を開始する前の状態を示す説明図である。
【図１１】中空ロッドの継足し工程を示す説明図である。
【図１２】中空ロッドの継足し工程を示す説明図である。
【図１３】中空ロッドの継足し工程を示す説明図である。
【図１４】中空ロッドの継足し工程を示す説明図である。
【図１５】繰り粉の排出状態を示す説明図である。
【図１６】本発明の施工方法で使用するアダプタの他の例を示す部分断面図である。
【図１７】繰り粉の排出状態の他の実施例を示す説明図である。
【図１８】図１７の部分拡大図である。
【図１９】清掃作業を示す説明図である。
【図２０】図１９の部分拡大図である。
【図２１】本発明の施工方法で使用する外管の他の例を示す正面図である。
【図２２】図２１に示す外管を自穿孔ロックボルトに取り付けた状態を示す説明図である。
【図２３】本発明による穿孔ビットの他の実施例であり、外管と組み合わせたを示す状態を示す説明図である。
【図２４】定着材の注入作業を示す説明図である。
【図２５】外管の引抜き作業を示す説明図である。
【図２６】定着が完了した状態を示す説明図である。
【図２７】本発明に係る施工方法の他の実施例において、その要部を示す説明図である。
【図２８】本発明に係る施工方法の他の実施例において、その要部を示す説明図である。
【符号の説明】
１，１００…穿孔ビット、２…中空ロッド、３…自穿孔ロックボルト、４…削孔装置，５，５１，５５…外管、６，６０…保護スリーブ、７…アダプタ、８Ａ…注入用アダプタ、８Ｂ…引抜き用アダプタ、９Ａ…座板、９Ｂ…締結ナット、１０…ビット本体、１１ａ〜１１ｆ…チップ、１２…先端側部分、１３…後端側部分、１４…段差部、１５，１０１…溝、１９…通孔、４０…支持フレーム、４２…削孔機[0001]
BACKGROUND OF THE INVENTION
The present invention provides, for example, a drill bit to be attached to the tip of a rotary rod or a self-drilling lock bolt of a drilling machine, a self-drilling lock bolt having this drill bit attached to a tip part of a hollow rod, and the self-drilling lock bolt. It relates to the construction method.
[0002]
[Prior art]
Conventionally, a drill bit made by implanting multiple tips (blade) made of cemented carbide such as tungsten carbide on the front end face of the bit body is a lock bolt body as a rotary rod of a drilling machine or a self-drilling lock bolt. It is attached to the tip part of the ground and used for excavation of the ground. By the way, for example, in a soft topsoil or sandy ground where trees are overgrown, the hole wall tends to collapse even if the drilling soil (flour) is discharged to the outside while drilling, and the drilling hole does not stand up easily. There are many. Under such construction conditions, a self-drilling lock bolt is generally applied. However, if the dusting is not discharged due to the collapse of the excavation hole, further drilling is difficult. In addition, the self-drilling lock bolt is tightened from the surrounding ground, which leads to insufficient rotational torque of the drilling machine. Moreover, even if somehow drilling is possible, the inside of the excavation hole is often partially blocked with earth and sand, so that injection of fixing material (grouting material) such as cement milk is hindered, Lock bolt fixing failure and insufficient cover thickness are likely to occur.
[0003]
For this reason, as a method of installing the lock bolt on the collapsible ground, a conventionally known double pipe drilling method is applied to the self-drilling lock bolt (for example, see Patent Documents 1 and 2). . In other words, the self-drilling lock bolt with a drill bit attached to the tip is covered with an outer pipe such as a steel pipe so that the drill bit protrudes from the end, and the inner self-drilling lock bolt is rotated and hammered. After drilling, injecting cement milk etc. through the hollow part of the self-drilling lock bolt or between its outer peripheral surface and the outer peripheral surface of the outer pipe, or pulling out the outer pipe after injection and fixing the self-drilled lock bolt in the excavation hole To do.
[0004]
[Patent Document 1]
JP 2002-38865 A (Gazette page 3, column 5, line 37-page 4, column 8, line 29, FIGS. 1 to 3)
[Patent Document 2]
JP 2002-129899 A (publication page 3, column 3, line 21-page 4, column 5, line 42, FIG. 1)
[0005]
[Problems to be solved by the invention]
In the above-mentioned Patent Document 1, there is a relatively large gap between the outer peripheral surface of the drill bit base and the inner peripheral surface of the outer tube end on the tip side of the self-piercing lock bolt, and these portions are mutually connected. The structure is not constrained. This gap is set so that the eccentric drill bit at the tip of the self-drilling lock bolt can pass through the outer pipe, and the shavings (dusting) accompanying the drilling are also discharged outside through the inner side of the outer pipe. It is like that. For this reason, the longer the length, the more the core blur occurs between the two, which is one of the causes of reducing the straightness of the drilling hole in combination with the use of the eccentric bit. Therefore, in order to insert an outer tube with a self-drilling lock bolt into a drilling hole with poor rectilinearity, it is necessary to drill a hole with a relatively large drilling bit in consideration of this, cost and workability. There is still room for improvement.
[0006]
Moreover, since the thing of patent document 2 is a structure which rotates an outer tube | pipe with a self-drilling lock bolt, core blur like the former does not arise. However, in this case, since the contact area with the hole wall increases, the frictional resistance also increases, and a large drilling machine with a large rotational torque is required. Further, when the hole wall collapses or the hole is bent, the frictional resistance is further increased. This tendency becomes more prominent as the drilling depth increases. Therefore, this has a big problem that it cannot be applied to a hand-held small hole drill such as a leg hammer.
[0007]
The present invention has been made in view of these problems of the prior art, and is optimal for a drilling method using an outer tube in combination. Even in such a case, the drilling diameter does not become larger than necessary, and the rotational torque is reduced. The purpose of the present invention is to provide a drilling bit that can be applied to a small and small-sized drilling machine, a self-drilling lock bolt using the bit, and a self-drilling lock bolt construction method.
[0008]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, in the invention according to claim 1 of the present application, an inner space portion that is open on the rear end side of a bit body having a tip implanted therein, and a bit body that communicates with the inner space portion. A through hole that opens in a part of the hollow hole, and drilling is performed while the pressurized fluid supplied from the other end side of the hollow rod that is fitted and connected to the inner space portion at one end side is ejected from the through hole. In the perforated bit, the bit main body is formed such that the rear end side portion has a smaller diameter than the front end side portion with the stepped portion interposed therebetween, and both ends of the outer peripheral surface guide the pressurized fluid jetted to the front end side to the rear end side. It is characterized by having a continuous flow path.
[0009]
In the perforated bit according to the present invention, the outer peripheral surface of the bit body is provided with a continuous flow path on both end sides such as a groove parallel to the axial center, and the pressurized fluid ejected to the front end side of the bit body at the time of drilling is It passes through the flow path and is guided to the rear end side. With such a configuration, the drilling bit according to the present invention is applied to a lock bolt or a drilling machine, such as drilling in a natural ground where the drilling hole is difficult to stand by itself, and the hollow rod (lock bolt body, rotating rod). Etc.) is suitable for drilling in a state surrounded by an outer pipe such as a steel pipe. That is, when drilling the hollow rod having the perforated bit at the tip thereof with the outer tube covered with the tip side portion of the perforated bit in which the tip is implanted, the tip side of the bit body In this case, the flour that has been scraped off by the tip passes through the flow path existing on the outer peripheral surface of the bit body together with the jetted pressurized fluid. Here, even if the clearance between the inner peripheral surface of the outer tube and the outer peripheral surface of the bit body is small, the flour is surely moved rearward through the flow path and discharged to the outside. Depending on the condition of the natural ground and the ratio of the outer diameter of the outer pipe to the outer diameter of the drilled bit applied, in addition to discharging from the inner side of the outer pipe through the flow path, the outer side of the outer pipe also becomes a discharge path .
[0010]
In this way, when an outer tube with an inner diameter close to the outer diameter of the rear end side portion of the bit body is used in combination, the bit body and the outer tube are almost fitted on the rear end side of the stepped portion of the bit body, and the rotation is performed. Since the hollow rod to be held is substantially held even at the tip side, both are always maintained in the coaxial state during drilling, and the core blur is reduced, and the straightness is improved as compared with the conventional unconstrained state. . For this reason, since the hole diameter may be close to the outer diameter of the outer tube, the outer diameter of the drill bit can be minimized, which greatly contributes to the rationalization of the hole drilling operation.
[0011]
According to a second aspect of the present invention, in the invention according to the first aspect, the plurality of flow paths are provided at equal intervals in the circumferential direction of the bit body and parallel to the axis. In this case, since the flour is dispersed in each flow path and passes through the flow path at the shortest distance, the discharge can be performed more efficiently.
[0012]
According to a third aspect of the present invention, the perforated bit according to the first aspect of the present invention is characterized in that the outer peripheral surface of the rear end portion of the bit body is formed as a tapered surface whose diameter decreases toward the rear. It is. In this case, in the rear end portion of the bit body, the portion closest to the stepped portion has the maximum diameter, and if the dimensions are close to the inner diameter of the outer tube, the gap between the two in the fitted state is further reduced. Therefore, it leads to the reduction of the core blur at the time of drilling, and the straightness is further improved. Furthermore, since the friction between the inner surface of the outer tube and the outer surface of the bit body is smaller than that in which the outer diameter of the rear end side portion is constant in the axial direction, it can be applied to a drilling machine with a small rotational torque. .
[0013]
According to a fourth aspect of the present invention, there is provided the perforated bit according to the first aspect of the present invention, wherein the through hole opens in the flow path. In this case, since parts other than the channel can be used freely, there is an advantage that there are few restrictions on the chip shape and its arrangement state.
[0014]
Further, in the invention according to claim 5, the inner space portion is opened at the rear end side of the bit body in which the tip is implanted on the tip side, and the through hole is formed in a part of the bit body so as to communicate with the inner space portion. It consists of a perforated bit that opens and a hollow rod whose one end is fitted and connected to the inner space of this perforated bit, and the pressurized fluid supplied from the other end of the hollow rod is ejected from the through hole of the perforated bit In the self-drilling lock bolt that performs drilling, the bit main body is formed such that the rear end portion has a smaller diameter than the front end portion with the stepped portion interposed therebetween, and pressure applied to the outer peripheral surface is ejected to the front end side. It is characterized by having continuous flow paths at both ends for guiding the fluid to the rear end side.
[0015]
That is, since the self-drilling lock bolt has a configuration in which the drill bit according to claim 1 is mounted on the tip of the hollow rod, it cannot be used alone as it is, and drilling is performed by covering the outer tube. Is particularly suitable. Even in the usage mode where an outer tube is used in combination, the flour will pass through the side of the bit body and move backward in the outer tube, or in addition to the outer tube, the outside of the outer tube will also be a discharge path , Surely discharged to the outside. Furthermore, if this self-drilling lock bolt is used, the diameter of the drilling hole can be reduced and the straightness is excellent.
[0016]
Furthermore, the invention according to claim 6 is a construction method of the self-drilling lock bolt according to claim 5, wherein the inner space portion is opened on the rear end side of the bit body in which the tip is implanted on the tip side, A perforated bit that communicates with the inner space and has a through hole in a part of the bit body, and a hollow rod that is fitted and connected to the inner space of the perforated bit. Self-drilling lock with end-side portions formed smaller in diameter than the front-end side portion with the stepped portion interposed therebetween, and a flow path continuous to both ends for guiding the pressurized fluid ejected to the front-end side to the rear-end side on those outer peripheral surfaces The outer tube is loosely inserted into the bolt leaving the tip side portion and connected to the drilling machine via the adapter on the other end side of the hollow rod, and the outer tube is connected to the step portion of the drill bit and the adapter. In a state where it can be idled against the hollow rod during Pressurized fluid supplied from the other end of the hollow rod is ejected from the through-hole of the perforation bit, and the pressurized fluid ejected to the front end is passed through the outer tube together with the flour through at least the passage of the perforation bit. After drilling while discharging to the outside, the fixing material is injected through the hollow rod and the outer tube is removed, and the self-drilling lock bolt is fixed by the fixing material filled between the inner surface of the hole wall. It is characterized by this.
[0017]
According to this construction method, drilling is performed in a state in which the self-drilling lock bolt is surrounded by the outer tube, and therefore it is possible to reliably drill even in a natural mountain where the hole wall tends to collapse. Further, since the hole is drilled without substantially rotating the outer tube, the frictional resistance generated when the rotating outer tube contacts the hole wall as in the conventional case can be minimized. Therefore, it is possible to use a small hole drill having a small rotational torque. Furthermore, by using the self-drilling lock bolt having the structure according to claim 5, even if it is surrounded by the outer tube, the dust is surely discharged to the outside through at least the inside of the outer tube, and the core blur in the outer tube is discharged. Can also be greatly reduced. For this reason, straightness is improved and insertion of the outer tube is not hindered. Therefore, the hole drilling diameter is set to the minimum necessary size according to the outer diameter of the outer tube to be used. Significantly streamlined. In addition, the self-drilling lock bolt and the outer tube are arranged substantially coaxially, and the self-drilling lock bolt is located at the axial center of the excavation hole and is filled with the fixing material at substantially the same thickness. A sufficient covering thickness can be secured, and the fixing force is also stabilized. Depending on the condition of the natural ground and the ratio of the outer diameter of the outer pipe to the outer diameter of the drilled bit applied, in addition to discharging from the inner side of the outer pipe through the flow path, the outer side of the outer pipe also becomes a discharge path .
[0018]
And the construction method which concerns on Claim 7 has an inner space part opened in the rear-end side of the bit main body by which the chip | tip was planted by the front end side, and connected to the said inner space part, and it penetrated a part of bit main body. And a hollow rod connected at one end to the inner space of the drill bit, the rear end portion of the bit body having a smaller diameter than the front end portion across the stepped portion. The outer tube is loosely inserted into the self-drilling lock bolt which is formed and has a flow path continuous to both ends for guiding the pressurized fluid jetted to the distal end side to the rear end side on the outer peripheral surfaces, leaving the distal end side portion. In addition, the other end of the hollow rod is connected to a drilling machine through an adapter, and the outer tube is held between the stepped portion of the drill bit and the adapter so as to be able to idle with respect to the hollow rod. The pressurized fluid supplied from the other end of the hollow rod After drilling through the outer tube and discharging the pressurized fluid ejected to the tip side through the outer tube through at least the flow path of the perforated bit together with the flour, Instead, a corrugated sheath tube is inserted, a fixing material is injected through a hollow rod, and a self-drilling lock bolt is fixed by a fixing material filled inside and outside the corrugated sheath tube.
[0019]
That is, the difference between this construction method and the construction method according to claim 6 is that a corrugated sheath pipe is inserted in place of the outer pipe and the fixing material is filled inside and outside after drilling. As a result, the outer tube can be immediately pulled out and used for drilling work at other locations. In addition, since it is more convenient to inject a curable fixing material such as cement milk, it is more convenient to fill many places at a time.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
The perforated bit according to the present invention and a self-piercing lock bolt using the perforated bit are provided with a flow path that continues from the front end side to the rear end side on the outer peripheral surface of the bit body, and discharge of the dust that is generated on the front end side of the flow path. It is a technical feature that it is used as a road. As a result, for example, in a natural ground where the excavation hole is not self-supporting, it is possible to efficiently carry out drilling by covering the outer tube with a self-drilling lock bolt, and reducing the diameter of the drilling hole as the straightness improves. Can do.
[0021]
The shape of the cemented carbide tip in the perforated bit is, for example, a two-stage conical shape with the most advanced portion as a plane, a hemispherical shape, a tapered shape with only the most advanced portion rounded, or a pyramid shape with the most advanced portion as a plane. There is no particular limitation on the shape, such as a button bit type or a cross bit type, and the shape is appropriately selected according to use conditions. In addition, the drill bit according to each claim of the present invention is not limited to the self-drilling lock bolt, and after drilling with the drill bit of the present invention attached to the drilling rod, the drill bit and drilling rod are withdrawn and re-examined. The present invention can also be applied to a pre-boring method in which a lock bolt is inserted. Furthermore, this self-drilling lock bolt can of course be used alone without using an outer tube at the time of drilling.
[0022]
【Example】
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. 1 to 3 show an embodiment of a drill bit according to the present invention, which are a front view, a plan view, and a cross-sectional view, respectively. The perforated bit 1 shown in the figure has a bit body 10 cast into a bottomed cylindrical shape, and six buttons 11a, 11b, 11c, which are substantially button-shaped and made of cemented carbide planted on the tip surface of the bit body. 11d, 11e, and 11f.
[0023]
The bit main body 10 has a rear end side portion 13 having a small diameter with a stepped portion 14 in between the front end side portion 12 in which six chips 11a to 11f are implanted. And in those outer peripheral surfaces, six grooves 15 parallel to the axial center at equal intervals in the circumferential direction are provided as flow paths for dusting etc., and the outer peripheral surfaces straddling the front end side portion 12 and the rear end side portion 13. It is provided over the entire length. On the other hand, as is apparent from FIG. 3, a rope screw 17 is formed on the inner surface of the inner space portion 16 with a length of about half from the rear end side opening portion toward the front end surface side. A concave portion 18 having a smaller diameter than that is provided on the distal end side of the rope screw 17, and two through holes 19 penetrate the wall surface obliquely forward from the concave portion 18 with respect to the axial center. The groove 15 is open. These two through-holes 19 are provided at opposing positions across the axis. The rear end portion 13 of the bit body 10 has the same outer diameter in the embodiment, but when formed on a tapered surface that is reduced in diameter toward the rear, in the fitting with the outer tube described later. Convenient.
[0024]
As can be seen from FIG. 2, the chips 11a to 11f of the six chips are arranged at a position slightly deviated from the center of the flat portion 12a formed at the center of the front end surface, that is, the axis of the bit body 2. The other chips 11b to 11e are implanted so as to be sequentially separated clockwise from the axis of the bit body 10 on the inclined surface portion 12b, and at opposite positions sandwiching the axis of the chip 11e located on the outermost periphery. A chip 11f is provided. Thereby, the positions of the tip portions of the chips 11a to 11e are sequentially retreated in the direction of the rear end surface of the bit body 10, and the trajectories of the two chips 11e and 11f overlap only at the outermost periphery. In the embodiment, the six chips 11 a to 11 f are arranged in a clockwise spiral shape, and this direction is the same as the rotation direction of the drill bit 1. Therefore, when the drilling bit 1 is applied to a counterclockwise drilling machine, it is necessary to arrange each chip counterclockwise. Thus, since each chip | tip 11a-11f is helically arrange | positioned in the same direction as the rotation direction of the drill bit 1, smooth rotation is performed even with a small number of chips. In addition, by forming a step in the axial direction at the tip position between adjacent chips, especially when drilling in places where tree roots are present, the roots are reliably cut and drilled. be able to.
[0025]
In the above embodiment, two chips 11e and 11f that draw the same locus only at the outermost peripheral position are provided. Such an arrangement is based on the spiral arrangement of the inner chip groups 11a to 11d that are implanted inward due to the presence of a plurality of chips in the outermost peripheral part where the work is the most burdensome and burdensome when drilling. It is suitable for increasing the diameter of the drill bit while maintaining the cost reduction effect (reduction of the number of chips). Further, the five chips 11b to 11f other than the chip 11a provided on the flat portion 12a are all planted so that the respective axes are substantially perpendicular to the inclined surface portion 12b. That is, since five chips rotate with the axis of the bit body 10 tilted outward, the locus increases by the tilted amount, and a large amount of work can be obtained even with a small-diameter chip. The two chips 11e and 11f located on the outermost periphery are planted in a place very close to the outer peripheral edge of the inclined surface portion 12b, and thus protrude slightly outward from the maximum diameter portion of the bit body 10. It becomes a state. The presence of these tips 11e and 11f makes it difficult for the outer peripheral surface of the distal end portion 12 of the bit body 10 to come into contact with the hole wall during drilling. A small drilling machine can be used.
[0026]
FIG. 4 shows a state where a self-drilling lock bolt 3 formed by mounting the drill bit 1 on the end of the hollow rod 2 is attached to the drilling device 4. The hole drilling device 4 used here is filed by the present applicant as Japanese Patent Application No. 2002-323087, and the hole drilling machine 42 is attached to a movable body 41 slidably attached to a support frame 40 having a cross beam shape. They are coupled and guided by the support frame 40 so as to advance and retreat. The moving body 41 includes a driving body 43, engages with a chain 44 disposed in the longitudinal direction of the support frame 40, and moves as a guide. The hollow rod 2 is formed with a rope screw over the entire length of the outer peripheral surface thereof, and is coupled by screwing with a rope screw 17 formed in the inner space 16 of the bit body 10 of the drill bit 1. Then, the outer pipe 5 such as a steel pipe into which the protective sleeve 6 is screwed on one end side is externally fitted to the self-piercing lock bolt 3 in such a direction that the protective sleeve 6 is located on the rear side. Here, in the state where the other end side of the outer tube 5 is fitted to the rear end side portion 13 of the perforated bit 1 and the opposite end portion of the protective sleeve 6 is fitted to a circular recess provided on the end face of the adapter 7. The self-drilling lock bolt 3 is screwed into the rod coupling portion 42a of the hole drilling machine 42. The rod coupling portion 42a has a female screw portion formed on the inner surface, a male screw portion 42b formed on the outer surface, and a non-threaded portion 42c provided on the distal end side of the male screw portion 42b. The adapter 7 is in a fitting state with respect to the unthreaded portion 42c in the same manner as the relationship between the outer tube 5 and the drill bit 1, but a large amount of friction is generated between the self-drilled lock bolt 3 and the non-rotating portion. It is desirable to fit with an appropriate gap that does not cause the occurrence of core blurring.
[0027]
5 and 6 are partial sectional views of the outer tube 5 and the protective sleeve 6, respectively. In FIG. 5, the outer tube 5 has an inner diameter slightly larger than the outer diameter of the rear end side portion 13 of the bit body 10 in the self-piercing lock bolt 3, and a protective sleeve 6 described later is provided on the inner surface of one end portion. The internal thread part 5a provided for the coupling | bonding is formed. As is apparent from FIG. 6, the protective sleeve 6 has a male screw portion 6a that can be screwed with the female screw portion 5a of the outer tube 5 at one end side, and the other end side following the intermediate large-diameter portion 6b is a small-diameter portion 6c. It has become. The large-diameter portion 6b is provided with two flat portions 6d for hanging a spanner at opposing positions across the axis. The protective sleeve 6 protects the thin female screw portion 5a from being easily deformed during drilling when the female screw portion 5a side of the outer tube 5 is directly fitted to an adapter 7 described later. It is intended for use.
[0028]
7 and 8 are a front view and a plan view of the adapter 7, and an opening 72 is provided on the peripheral wall 71 with a length corresponding to almost a half of the circumference, leaving both ends. Further, as is apparent from FIG. 9, circular recesses 73 and 74 are formed on the end surfaces of the annular portions at both ends, respectively, which fit into the protective sleeve 6 and the unthreaded portion 42 c of the hole drilling machine 42.
[0029]
Next, the construction method of the self-piercing lock bolt 3 will be described. First, as shown in FIG. 9, the outer tube 5 is inserted into the self-piercing lock bolt 3 until the end of the outer tube 5 is fitted to the rear end side portion 13 of the drilling bit 1. The protective sleeve 6 is screwed into the female screw portion 5a on the side. Subsequently, the adapter 7 is inserted into the protruding portion of the self-piercing lock bolt 3, and the circular recess 73 provided on one end side thereof is fitted into the small diameter portion 6 c of the protective sleeve 6. Then, as shown in FIG. 10, the other end side of the hollow rod 2 of the self-drilling lock bolt 3 is screwed into the rod coupling portion 42 a of the hole drilling machine 42 and is provided on the opposite side of the protective sleeve 6. The fitting is completed by fitting the recess 74 to the unthreaded portion 42c of the rod coupling portion 42a. The hole drilling device 4 to which the self-drilling lock bolt 3 is attached in this way has its support frame 40 directed to the natural ground G, and air or the like is added by a compressor (not shown) connected to the hole drilling machine 42. The hole drilling machine 42 is driven while the pressurized fluid is supplied to the self-drilling lock bolt 3, and the ground G is excavated by the rotation and striking force, and drilling is performed to such a depth that the end of the outer pipe 5 remains.
[0030]
When the drilling of one hollow rod 2 is finished, as shown in FIG. 11, a tool (not shown) such as a pipe wrench is inserted into the opening 72 of the adapter 7 to rotate the hollow rod 2 in the reverse direction. The self-drilling lock bolt 3 is removed from the drilling machine 42. Next, as shown in FIG. 12, the adapter 7 is removed, and the protective sleeve 6 is removed from the outer tube 5. Subsequently, another hollow rod 2 is added via the coupler 20 as shown in FIG. 13, and the extension outer tube 51 is inserted as shown in FIG. The extension outer tube 51 is formed with a female screw portion 51a on one end side and a male screw portion 51b on the other end side. Then, similarly to the first case, the protective sleeve 6 and the adapter 7 are attached, and the hole is reconnected to the hole drilling machine 42 to continue drilling. These operations are repeated until a predetermined depth is reached.
[0031]
FIG. 15 shows a discharge state of the dusting generated in the hole drilling. That is, the pressurized fluid supplied to the inside of the hollow rod 2 is ejected forward from the through-hole 19 of the perforated bit 1, and the groove provided on the side surface of the bit main body 10 together with the dust that has been shaved by the tips 11 a to 11 f. 15, the gap S <b> 1 between the inner surface of the outer tube 5 and the outer surface of the hollow rod 2 is moved. The dusting and the pressurized fluid also pass through the protective sleeve 6 attached to the end of the outer tube 5 and are discharged from the opening 72 of the adapter 7 to the outside. In this case, even if the outer tube 5 is fitted to the rear end side portion 13 of the bit body 10 with a slight gap, the presence of the groove 15 between the two ensures that the dusting is made backward. It moves and is discharged outside. In this way, since the outer tube 5 is fitted to the bit body 10 with a slight gap, it is possible to drill in a straight state while effectively preventing the drill bit 1 from swinging. For this reason, the drill bit 1 close to the outer diameter of the outer tube 5 can be used, and a hole with the minimum necessary inner diameter can be excavated, leading to rationalization of the drilling operation. Furthermore, since the outer tube 5 is not rotated at the time of drilling, a drilling machine having a relatively small rotational torque can be applied. In the present embodiment, the case of drilling while adding a plurality of hollow rods 2 and outer tubes 5 and 51 has been described. Of course, depending on the drilling depth, only one may be targeted without adding. Further, for example, the outer tube 5 may be used in combination with the soft surface layer portion, and the outer tube 5 or the like may not be inserted into the hard ground layer portion below.
[0032]
FIG. 16 is another embodiment of a protective sleeve. The protective sleeve 60 shown in the figure is provided with a female screw portion 60a, whereas the protective sleeve 6 used in the above embodiment uses the male screw portion 6a as a coupling means with the outer tubes 5 and 51. If this protective sleeve 60 is used, the joint with the outer tubes 5 and 51 does not protrude toward the inner surface side, so that the gap with the outer peripheral surface of the hollow rod 2 is ensured to be the same as that of the other portions. The powder discharge is further improved. In this case, a screw provided on one end side of the outer tube 5 is used as a male screw part, and an extension outer tube 51 is connected in the opposite direction to the above-described embodiment, and a suitable coupler having a female screw on the inner surface. May be coupled to the drilling machine 42 via
[0033]
FIG. 17 and FIG. 18 show an embodiment in which the discharge path of the flouring is different. Such a situation occurs, for example, when the outer diameter of the distal end portion 12 of the bit body 10 is larger than the outer diameter of the outer tube 5 and a certain gap is formed around the outer tube 5. That is, the pressurized fluid supplied to the inside of the hollow rod 2 is ejected forward from the through-hole 19 of the perforated bit 1, and the groove provided on the side surface of the bit main body 10 together with the dust that has been shaved by the tips 11 a to 11 f. 15 is divided into a path that moves through the gap S1 between the inner surface of the outer tube 5 and the outer surface of the hollow rod 2, and a path that passes through the gap S2 outside the outer tube 5. The dust and the pressurized fluid also pass through the protective sleeve 6 attached to the end of the outer tube 5 and are discharged to the outside from the opening 72 of the adapter 7 and also from the opening of the natural ground G. Will be.
[0034]
By the way, when dusting passes through the gap S2 outside the outer tube 5 as described above, the gap S2 is a partial area under circumstances where the natural ground G does not stand on its own or a part of the excavation hole collapses. There is a risk of being blocked. In such a case, dusting is likely to be clogged in the middle of the gap S2, which may adversely affect the fixing operation described later. That is, at the tip side of the closed portion, the dust is retained outside the outer tube 5, and a thin layer of the dust is formed on the inner surface of the excavation hole after the outer tube 5 is pulled out. On the other hand, fixing materials such as cement milk generally have a high viscosity and do not necessarily have good permeability. For this reason, when such a thin layer of flour is present, the fixing material does not sufficiently permeate the back side (natural ground G), which causes a reduction in fixing power. Therefore, it is desirable to clean the gap S2 outside the outer tube 5 during or after drilling.
[0035]
19 and 20 show a cleaning method for the inside of the hole. First, the hollow rod 2 and the adapter 7 are removed from the hole drilling machine 42. Next, a male thread portion of a drawing adapter 8B used in a fixing operation to be described later is screwed and connected to the outer tube 51, and is coupled to the hole drilling machine 42 via a female thread portion formed on the other end side. When pressurized air is fed from the hole drilling machine 42, the pressurized air passes through the gaps S1 between the outer tubes 51 and 5 and the hollow rod 2 and the inside of the hollow rod 2, and each is provided on the side surface of the bit body 10. It ejects forward from the groove 15 and the through hole 19. The jetted compressed air passes through the gap S2 outside the outer tubes 5 and 51, so that the dust that remains on the inner surface of the excavation hole can be reliably discharged to the outside.
[0036]
21 and 22 show different embodiments of the outer tube. The outer tube 55 has six notches 55a formed on the tip side. In this case, the notches 55a are provided at intervals of 60 degrees in the circumferential direction, and are opposed to the grooves 15 provided on the side surface of the drill bit 1. If such a cutout 55a is provided, a large entrance can be secured when the milled flour enters the outer tube 55, so that the discharge of the flour is better, especially for clayey grounds. It is suitable for doing. It is to be noted that increasing the individual widths instead of reducing the number of grooves 101 provided on the side surfaces as in the perforated bit 100 shown in FIG. 23 is also an effective means for promoting the discharge of flour.
[0037]
Next, FIG. 24 to FIG. 26 show the fixing work after the drilling is completed. When the drilling is completed, the inside of the hole is cleaned by the above method, and then, as shown in FIG. 24, an injection adapter 8A is attached to the end of the hollow rod 2 removed from the drilling machine, Inject the fixing material. The flow of the fixing material is the same as that of the pressurized fluid, and is ejected forward from the through hole 19 of the drill bit 1 at the tip through the inside of the hollow rod 2 and passes through the groove 15 provided on the side surface of the bit body 10. Then, the gas flows through a gap S1 between the inner surface of the outer tube 5 and the outer surface of the hollow rod 2 and a gap S2 between the inner surface of the excavation hole and the outer surface of the outer tube 5. And it checks that it overflows from the inside and outside of the edge part of the outer pipe | tube 51 arrange | positioned on the exterior side. In addition, when the gap S2 outside the outer tube 51 is very small, it may be confirmed by the overflow from the inner side of the outer tube 51.
[0038]
Next, as shown in FIG. 25, the male threaded portion of the extraction adapter 8B is screwed into and coupled to the female threaded portion 51a at the end of the outer tube 51, and the external threaded portion formed on the other end is ground. Connect to the perforator 42. By retracting the hole drilling machine 42 in this state, all the outer tubes 5 and 51 can be pulled out. If the surface of the fixing material sinks after the outer tubes 5 and 51 are pulled out, additional injection is performed. Then, as shown in FIG. 26, the fixing work is completed by inserting the seat plate 9A through the end of the self-drilling lock bolt 1 protruding from the natural ground G and tightening it with the fastening nut 9B.
[0039]
27 and 28 show another embodiment of the construction method. In this case, after the drilling operation is completed, as shown in FIG. 27, the corrugated sheath tube 5A made of an appropriate material is inserted into the outer tubes 5 and 51. Then, as shown in FIG. 28, the outer tube 51 and the like are pulled out, and thereafter the fixing work is performed according to the steps shown in FIG. That is, the corrugated sheath tube 5A is left as it is, and the fixing material is filled inside and outside the corrugated sheath tube 5A. According to this construction method, if the outer pipes 5 and 51 are pulled out immediately after the end of the drilling and are repeatedly applied to the next place, the fixing material injection work can be performed collectively, leading to improved workability. .
[0040]
In the self-drilling lock bolt 1 of the above embodiment, a full screw bolt is applied to the hollow rod 2, but of course it is not limited to this. No problem. Further, the shape of the bit body, the shape and number of chips, the position of the through hole, etc. can be changed for the perforated bit itself. That is, it is only necessary to appropriately select these according to the use conditions such as use as a self-drilling lock bolt or application to a drilling machine, and various modifications can be made within the technical idea of the present invention. It is.
[0041]
【The invention's effect】
As described above, the perforated bit according to the present invention, the self-drilling lock bolt using the perforated bit, and the construction method thereof are provided on the outer peripheral surface of the bit body with a continuous channel from the front end side to the rear end side. Can be efficiently used even when drilling holes by covering the outer pipe with a self-drilling lock bolt in a ground where the excavation hole does not stand on its own. Also, since the straight running performance is greatly improved, it is possible to minimize the drilling diameter according to the outer pipe. Moreover, the practical effect is extremely great, such as the use of a drilling machine with a small rotational torque.
[Brief description of the drawings]
FIG. 1 is a front view showing an example of a perforated bit according to the present invention.
FIG. 2 is a plan view of the drill bit.
FIG. 3 is a cross-sectional view of the drill bit.
FIG. 4 is an explanatory view showing a state in which a self-drilling lock bolt equipped with the drill bit is attached to a drilling device.
FIG. 5 is a partial cross-sectional view of an outer tube used in the construction method of the present invention.
FIG. 6 is a partial cross-sectional view of a protective sleeve used in the construction method of the present invention.
FIG. 7 is a front view of an adapter used in the construction method of the present invention.
FIG. 8 is a plan view of the adapter.
FIG. 9 is an explanatory view showing a method for attaching the protective sleeve and the adapter.
FIG. 10 is an explanatory view showing a state before starting drilling.
FIG. 11 is an explanatory view showing a process of adding a hollow rod.
FIG. 12 is an explanatory view showing a process of adding a hollow rod.
FIG. 13 is an explanatory view showing a process of adding a hollow rod.
FIG. 14 is an explanatory view showing a process of adding a hollow rod.
FIG. 15 is an explanatory view showing a discharge state of the dusting.
FIG. 16 is a partial cross-sectional view showing another example of an adapter used in the construction method of the present invention.
FIG. 17 is an explanatory view showing another embodiment of the dusting discharge state.
18 is a partially enlarged view of FIG.
FIG. 19 is an explanatory diagram showing a cleaning operation.
20 is a partially enlarged view of FIG. 19;
FIG. 21 is a front view showing another example of the outer tube used in the construction method of the present invention.
22 is an explanatory view showing a state in which the outer tube shown in FIG. 21 is attached to a self-drilling lock bolt.
FIG. 23 is an explanatory view showing a state in which a perforated bit according to another embodiment of the present invention is combined with an outer tube.
FIG. 24 is an explanatory diagram showing a fixing material injection operation;
FIG. 25 is an explanatory view showing a drawing operation of the outer tube.
FIG. 26 is an explanatory diagram showing a state in which fixing is completed.
FIG. 27 is an explanatory view showing the main part of another embodiment of the construction method according to the present invention.
FIG. 28 is an explanatory view showing the main part of another embodiment of the construction method according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1,100 ... Drilling bit, 2 ... Hollow rod, 3 ... Self-drilling lock bolt, 4 ... Drilling device, 5, 51, 55 ... Outer pipe, 6,60 ... Protection sleeve, 7 ... Adapter, 8A ... Adapter for injection , 8B ... Adapter for extraction, 9A ... Seat plate, 9B ... Fastening nut, 10 ... Bit body, 11a to 11f ... Tip, 12 ... Tip side portion, 13 ... Rear end side portion, 14 ... Stepped portion, 15, 101 ... Groove, 19 ... through hole, 40 ... support frame, 42 ... hole drilling machine

Claims

Provided with an inner space that opens to the rear end side of the bit body with the tip implanted in the tip side, and a through hole that communicates with the inner space and opens in a part of the bit body. In the drill bit that performs drilling while ejecting the pressurized fluid supplied from the other end side of the hollow rod to which the sides are fitted and connected from the through hole, the bit body has a stepped portion at the rear end side portion. A perforation bit, characterized in that it is formed with a smaller diameter than the front end portion, and has a continuous flow path at both ends that guides the pressurized fluid ejected to the front end side to the rear end side.

2. The perforated bit according to claim 1, wherein a plurality of the flow paths are provided in parallel with the axial center at equal intervals in the circumferential direction.

The perforated bit according to claim 1 or 2, wherein an outer peripheral surface of a rear end side portion of the bit body is formed as a tapered surface having a diameter reduced toward the rear.

The perforation bit according to any one of claims 1 to 3, wherein the through hole is open to the flow path.

A perforated bit having an inner space opened on the rear end side of the bit body in which a chip is implanted on the front end side, and a through hole opened in a part of the bit body in communication with the inner space. A self-drilling lock bolt comprising a hollow rod whose one end is fitted and connected to the inner space, and drilling while the pressurized fluid supplied from the other end of the hollow rod is ejected from the through-hole of the drilling bit The bit body is formed such that the rear end portion has a smaller diameter than the front end portion with the stepped portion interposed therebetween, and the outer peripheral surface thereof is continuous with both ends leading the pressurized fluid ejected to the front end side to the rear end side. A self-drilling lock bolt characterized by comprising a flow path.

A perforated bit having an inner space opened on the rear end side of the bit body in which a chip is implanted on the front end side, and a through hole opened in a part of the bit body in communication with the inner space. It consists of a hollow rod with one end fitted and connected to the inner space, and the rear end portion of the bit body is formed with a smaller diameter than the front end portion across the step portion, A self-drilling lock bolt having a continuous flow path at both ends for guiding the jetted pressurized fluid to the rear end side is loosely inserted into the outer tube while leaving the tip side portion, and an adapter is connected to the other end side of the hollow rod. The outer tube is supplied from the other end side of the hollow rod in a state in which the outer tube is held between the stepped portion of the drill bit and the adapter so as to be idled with respect to the hollow rod. Pressurized fluid is ejected from the through hole of the drill bit and ejected to the tip side Drilling the pressurized fluid together with the powdered powder through the outer tube through at least the flow path of the drilling bit and discharging it to the outside, and then injecting the fixing material through the hollow rod and removing the outer tube A self-drilling lock bolt construction method, wherein the self-drilling lock bolt is fixed by a fixing material that is removed and filled between the inner surface of the hole wall.

A perforated bit having an inner space opened on the rear end side of the bit body in which a chip is implanted on the front end side, and a through hole opened in a part of the bit body in communication with the inner space. It consists of a hollow rod with one end fitted and connected to the inner space, and the rear end portion of the bit body is formed with a smaller diameter than the front end portion across the step portion, A self-drilling lock bolt having a continuous flow path at both ends for guiding the jetted pressurized fluid to the rear end side is loosely inserted into the outer tube while leaving the tip side portion, and an adapter is connected to the other end side of the hollow rod. The outer tube is supplied from the other end side of the hollow rod in a state in which the outer tube is held between the stepped portion of the drill bit and the adapter so as to be idled with respect to the hollow rod. Pressurized fluid is ejected from the through hole of the drill bit and ejected to the tip side After drilling the pressurized fluid together with the powdered powder through the outer tube through at least the passage of the perforated bit and discharging it to the outside, a corrugated sheath tube is inserted instead of the outer tube and a hollow rod A self-drilling lock bolt is fixed by injecting a fixing material through the fixing member and fixing the self-drilling lock bolt with the fixing material filled inside and outside the corrugated sheath tube.