JP2013133627A - Widening and drilling device and drilling method using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that burdens during widening work of a large diameter part are large.SOLUTION: A widening and drilling device includes a base part 1 disposed at a distal end of a pipe P and a plurality of openable and closable widening bits 2, 2a... attached to the base part 1, has a water conducting hole 3 formed in a center longitudinal direction of the base part 1, has jet holes 4 and 4a that are communicated with the water conducting hole 3 and are capable of jetting water inside a drilling part H, is insertable into the drilling part H in the state of closing the widening bits 2, 2a..., and is capable of partially widening the drilling part H by opening the drilling bits 2, 2a... inside the drilling part H. After the widening and drilling device is inserted into the drilling part H formed in the soil in the state of closing the widening bits 2, 2a..., the widening bits 2, 2a... are opened at a widening part in the drilling part H, the widening and drilling device in the state of completely opening the widening bits 2, 2a... is repeatedly moved back and forth while being rotated, and a part of the drilling part H is widened to form a large diameter part Hb. Thus, by partially forming the large diameter part Hb while gradually scraping a hole wall of the drilling part H of a small diameter formed beforehand, burdens during the widening work are reduced.

Description

本発明は、地盤に形成された削孔部を部分的に拡径する掘削装置及び該拡径掘削装置を使用する削孔工法に関する。   The present invention relates to a drilling device for partially expanding a drilling portion formed in the ground and a drilling method using the diameter drilling device.

従来、地盤を削孔して、この削孔部内にグラウト材等を注入して杭体を形成する工法にあっては、引抜き方向の外力に対する耐力を向上させるべく、削孔部の末端部位を拡径することがある。   Conventionally, in the method of forming a pile body by drilling the ground and injecting grout material etc. into this drilled part, the end part of the drilled part is to be improved in order to improve the resistance to external force in the drawing direction. The diameter may be expanded.

具体的には、中空の掘削ロッドの先端に、互いに一側面を近接し合って掘削ロッドの前方に向かって突出する縮小位置から、９０度程度左右対称に互いに離れるように横向きに倒した拡大位置にかけて回転する左右一対の掘削ビットを設け、前記掘削ロッドの内部に進退自在に挿入した連結ロッドの先端に、前記掘削ビットの後端部を押し込んで前記縮小位置から前記拡大位置に回転するビット作動ロッドを設け、前記連結ロッドの後端を前記掘削ロッドの後端に設けたシリンダのピストンロッドに連結した掘削装置が見受けられ、該掘削装置の掘削ビットを縮小位置にした状態で前記掘削ロッドを回転しながら所要長掘進した後、前記シリンダのピストンロッドを前進作動してこれに連動する前記ビット作動ロッドにより前記掘削ビットの後端部を押し込んで拡大位置に回転させ、この状態で掘削ロッドを回転しながら掘進することにより、小径部位と大径部位とが段差部をもって連続した削孔部を形成することができ、該削孔部の外周面積の増大に伴う摩擦力の増大に加えて、段差部の支圧面の剪断耐力によって強力な引張抵抗を保持することで、杭体の長さを短くすることを可能にしている（例えば、特許文献１参照）。   Specifically, at the tip of the hollow excavation rod, from the reduced position where one side is close to each other and protrudes toward the front of the excavation rod, the enlarged position that is tilted sideways so as to be symmetrically separated from each other by about 90 degrees A pair of left and right excavation bits that rotate toward the end of the excavation rod, and a bit operation that rotates from the contraction position to the expansion position by pushing the rear end of the excavation bit into the front end of a connecting rod that is inserted into the excavation rod so as to freely advance and retract. A drilling device in which a rod is provided and a rear end of the connecting rod is connected to a piston rod of a cylinder provided at a rear end of the drilling rod can be seen, and the drilling rod is placed in a state where the drilling bit of the drilling device is in a contracted position. After the required length of excavation while rotating, the piston rod of the cylinder is moved forward and the bit operating rod interlocked therewith moves the drill bit. By pushing the end portion and rotating it to the enlarged position, and digging while rotating the excavating rod in this state, it is possible to form a drilling portion in which the small diameter portion and the large diameter portion are continuous with a stepped portion, and the cutting portion is formed. In addition to an increase in frictional force accompanying an increase in the outer peripheral area of the hole, it is possible to shorten the length of the pile body by maintaining a strong tensile resistance by the shear strength of the bearing surface of the stepped portion. (For example, refer to Patent Document 1).

特開２０００−６４７５９号公報JP 2000-64759 A

しかし、上記従来技術にあっては、小径部位と大径部位を同じ掘削装置で掘削することができるが、小径部位より先の未掘削部位を、掘削面を少しずつ削り取りながら掘進することになるため、回転数の割に掘進量が少なく、作業速度が遅くなってしまうなど、解決せねばならない課題があった。   However, in the above prior art, the small diameter part and the large diameter part can be excavated by the same excavator, but the unexcavated part ahead of the small diameter part is excavated while scraping the excavated surface little by little. For this reason, there are problems that must be solved, for example, the amount of excavation is small with respect to the number of rotations, and the working speed becomes slow.

本発明は、上記従来技術に基づく、拡径作業時の負担が大きい課題に鑑み、パイプの先端に配設された基体部と、該基体部に取り付けられた複数の開閉可能な拡径ビットを有し、前記基体部の中央長手方向に通水孔を形成すると共に、該通水孔に連通して削孔部内に水を噴出可能な噴出孔を有し、前記拡径ビットを閉じた状態で削孔部内に挿入可能にすると共に、該削孔部内で掘削ビットを開いて削孔部を部分的に拡径可能にした拡径掘削装置を、地盤に形成された削孔部内に、拡径ビットを閉じた状態で挿入した後、削孔部における拡径個所で拡径ビットを開き、該拡径ビットが完全に開いた状態の拡径掘削装置を回転させながら前後動させることを繰り返して、削孔部の一部を拡径することによって、小径な削孔部の掘削手段を抜いた後に本発明に係る拡径掘削装置を挿入し拡径ビットを開く作業が必要になるが、予め形成された小径な削孔部の孔壁を徐々に削り取りながら大径部位を部分的に形成することで、拡径作業時の負担を軽減する様にして、上記課題を解決する。   The present invention is based on the above-described prior art, and in view of the problem of a large burden during diameter expansion work, a base portion disposed at the tip of a pipe and a plurality of openable / closable diameter expansion bits attached to the base portion. A state in which a water passage hole is formed in the central longitudinal direction of the base portion, and has a jet hole that communicates with the water passage hole and is capable of jetting water into the drilling portion, and the diameter expansion bit is closed. The diameter expanding excavator, which can be inserted into the hole drilling part and opens the drilling bit in the hole drilling part to partially expand the hole drilling part, is expanded in the hole drilling part formed in the ground. After inserting the diameter bit in a closed state, open the diameter expansion bit at the diameter expansion portion in the drilling part, and repeatedly move the diameter expansion excavator with the diameter expansion bit fully open while moving back and forth. After removing the drilling means for the small-diameter hole by expanding a part of the hole Although it is necessary to insert the diameter expansion excavator according to the present invention and open the diameter expansion bit, the large diameter portion is partially formed while gradually removing the hole wall of the small diameter drilling portion formed in advance. Thus, the above-mentioned problems are solved by reducing the burden during the diameter expansion work.

具体的には、前記基体部は略円柱状で、先端面中央に突出部を設け、前記通水孔は基端側を前記基体部の基端側で開口させると共に、先端側が前記突出部に至る様に形成され、２個の前記噴出孔を、前記突出部の直径方向に配置し側面で開口する様に形成され、２枚の前記拡径ビットを、前記基体部の先端面で前記噴出孔の延長線上に配置し開閉可能に軸着した拡径掘削装置とする。   Specifically, the base portion has a substantially cylindrical shape, and a protruding portion is provided at the center of the front end surface. The water passage hole opens the base end side at the base end side of the base portion, and the front end side is at the protruding portion. Formed so that the two ejection holes are arranged in the diameter direction of the projecting portion and open at the side surface, and the two enlarged diameter bits are ejected from the distal end surface of the base portion. A diameter-excavating device that is arranged on the extended line of the hole and is pivotally mounted so as to be openable and closable.

或いは、基体部を中空丸棒状として、中空部を前記通水孔とし、２本のビット部材の先端同士を軸着して形成した屈伸可能な拡径ビットを、前記基体部の外周方向に等間隔に配置すると共に、一方のビット部材の基端部を、基体部の先端部に外嵌された固定リングに、他方のビット部材の基端部を、基体部の中間部に外嵌された可動リングに軸着し、前記基体部の外周面における少なくとの前記可動リングの移動範囲の部位にネジ溝を形成すると共に、該ネジ溝に噛み合う螺条を前記可動リングの内周面に形成した拡径掘削装置とする。   Or, the base part is formed into a hollow round bar shape, the hollow part is used as the water passage hole, and a bendable / extendable diameter expanding bit formed by axially attaching the tips of the two bit members in the outer peripheral direction of the base part, etc. The base end portion of one bit member was fitted to the fixing ring fitted to the tip portion of the base portion, and the base end portion of the other bit member was fitted to the intermediate portion of the base portion. Attached to the movable ring, a screw groove is formed at least at a position of the movable ring movement range on the outer peripheral surface of the base portion, and a thread that meshes with the screw groove is formed on the inner peripheral surface of the movable ring. The expanded diameter drilling device.

要するに本発明は、予め形成された所定長さの削孔部の一部を拡径する拡径掘削装置であって、パイプの先端に配設された基体部と、該基体部に取り付けられた複数の開閉可能な拡径ビットを有し、前記基体部の中央長手方向に通水孔を形成すると共に、該通水孔に連通して削孔部内に水を噴出可能な噴出孔を有し、前記拡径ビットを閉じた状態で削孔部内に挿入可能にすると共に、該削孔部内で掘削ビットを開いて削孔部を部分的に拡径可能にしたので、従来技術と同様に、小径部位と大径部位が連続した削孔部を形成することができ、且つ該削孔部の外周面積の増大に伴う摩擦力の増大に加えて、段差部の支圧面の剪断耐力によって強力な引張抵抗を保持することで、杭体の長さを短くすることが出来る他、小径部位に連続して拡径部位を掘削するのではなく、掘削された小径な削孔部の孔壁を徐々に削り取って部分的に拡径し、且つ開いた状態の各拡径ビットのビット部材間には隙間が形成されるため、拡径作業時に各拡径ビットに作用する負担を軽減すること出来る。   In short, the present invention is a diameter-expanding excavator that expands a part of a predetermined length of a drilled hole portion, a base portion disposed at the tip of a pipe, and attached to the base portion It has a plurality of openable diameter expanding bits, has a water passage hole in the central longitudinal direction of the base portion, and has an ejection hole that communicates with the water passage hole and can eject water into the drilling portion. The diameter expanding bit can be inserted into the drilling portion in a closed state, and the drilling bit is opened in the drilling portion to partially expand the drilling portion. It is possible to form a drilling portion where a small-diameter portion and a large-diameter portion are continuous, and in addition to an increase in frictional force accompanying an increase in the outer peripheral area of the drilling portion, it is possible to increase the strength by the shear strength of the bearing surface of the stepped portion. By maintaining the tensile resistance, the length of the pile body can be shortened, and the diameter-expanded part is continuous with the small-diameter part. Rather than excavating, the hole wall of the drilled small-diameter drilling part is gradually scraped to partially expand the diameter, and a gap is formed between the bit members of each expanded diameter bit in an open state. In addition, it is possible to reduce the load acting on each diameter expansion bit during diameter expansion work.

前記基体部は略円柱状で、先端面中央に突出部を設け、前記通水孔は基端側を前記基体部の基端側で開口させると共に、先端側が前記突出部に至る様に形成され、２個の前記噴出孔を、前記突出部の直径方向に配置し側面で開口する様に形成され、２枚の前記拡径ビットを、前記基体部の先端面で前記噴出孔の延長線上に配置し開閉可能に軸着したので、噴出孔から噴出した水により閉じた状態の拡径ビットを孔壁に当たるまで開くことが出来ると共に、単に後退させるだけで閉じることが出来るため、開閉のための機械的構成を講じずに拡径ビット開閉可能な拡径掘削装置を提供することが出来る。   The base portion is substantially cylindrical, and a protrusion is provided in the center of the tip surface. The water passage hole is formed so that the base end side is opened at the base end side of the base portion, and the tip end side reaches the protrusion. Two ejection holes are arranged in the diametrical direction of the projecting portion and are formed so as to open on the side surface, and the two enlarged diameter bits are placed on the extension line of the ejection hole at the distal end surface of the base portion. Since it is arranged and pivotally attached so that it can be opened and closed, the diameter-enlarged bit closed by the water ejected from the ejection hole can be opened until it hits the hole wall, and it can be closed simply by retreating, so it can be opened and closed A diameter expanding excavator capable of opening and closing a diameter expanding bit without taking a mechanical configuration can be provided.

前記拡径ビットの表面に突起を設け、該突起は拡径ビットが開いた状態で削孔部より外側に位置させたので、掘削面に先ず突起で溝を形成した後に拡径ビットで削ることが出来るため、該拡径ビットへの負荷が軽減され、効率よく拡径作業を行うことが出来る。   Since the protrusion is provided on the surface of the diameter expansion bit, and the protrusion is positioned outside the drilling portion with the diameter expansion bit opened, a groove is first formed on the excavation surface with a protrusion and then the diameter expansion bit is cut. Therefore, the load on the diameter expansion bit is reduced, and the diameter expansion operation can be performed efficiently.

前記突起の夫々を、基体部の先端面の中心に対する等間隔の同心円の夫々に１個ずつ配置したので、掘削面に各突起で形成される溝が重ならないため、更に効率よく拡径作業を行うことが出来る。   Since each of the projections is arranged one by one in concentric circles at equal intervals with respect to the center of the front end surface of the base portion, the grooves formed by the projections do not overlap with the excavation surface. Can be done.

前記基体部を中空丸棒状としてこの中空部を前記通水孔とし、前記噴出孔を基体部の先端側に形成し、２本のビット部材の先端同士を軸着して形成した屈伸可能な拡径ビットを、前記基体部の外周方向に等間隔に配置すると共に、一方のビット部材の基端部を、基体部の先端部に外嵌された固定リングに、他方のビット部材の基端部を、基体部の中間部に外嵌された可動リングに軸着し、前記基体部の外周面における少なくとの前記可動リングの移動範囲の部位にネジ溝を形成すると共に、該ネジ溝に噛み合う螺条を前記可動リングの内周面に形成したので、基体部が設けられたパイプを正逆回転させる簡単な操作で、可動リングを進退させて拡径ビットを簡単に開閉させることが出来る。   The base portion is formed as a hollow round bar, the hollow portion is used as the water passage hole, the ejection hole is formed on the tip end side of the base portion, and the tip portions of the two bit members are axially attached to each other. The radial bits are arranged at equal intervals in the outer peripheral direction of the base portion, and the base end portion of one bit member is fixed to the fixing ring externally fitted to the tip end portion of the base portion, and the base end portion of the other bit member Is pivotally attached to a movable ring that is externally fitted to the intermediate portion of the base portion, and a screw groove is formed at a portion of the outer peripheral surface of the base portion at least within the movable range of the movable ring, and meshes with the screw groove. Since the thread is formed on the inner peripheral surface of the movable ring, the movable ring can be advanced and retracted by a simple operation of rotating the pipe provided with the base portion in the forward and reverse directions to easily open and close the diameter expansion bit.

固定リングに、基体部先端面より先に突出する固定突起を設けたので、拡径ビットの開閉作業に固定突起を削孔部の末端面に差し込んで、地盤側に対し固定リングを固定すれば、基体部を回転させても、固定リング及び可動リングが基体部と一緒に回転しないため、可動リングを確実に進退させて拡径ビットを開閉させることが出来る。   Since the fixing ring is provided on the fixing ring that protrudes beyond the front end surface of the base part, if the fixing ring is fixed to the ground side by inserting the fixing protrusion into the end face of the drilling part for opening and closing the diameter expanding bit Even if the base portion is rotated, the fixed ring and the movable ring do not rotate together with the base portion, so that the movable ring can be reliably advanced and retracted to open and close the diameter expanding bit.

２本のビット部材の先端に尖端部を形成したので、屈曲状態の拡径の屈曲部位に尖端部が突出することから、削孔部の孔壁を削り取り易くなるため、作業効率の向上を図ることが出来る。   Since the pointed portion is formed at the tip of the two bit members, the pointed portion protrudes from the bent portion of the expanded diameter in the bent state, so that it becomes easy to scrape the hole wall of the drilled portion, thereby improving work efficiency. I can do it.

前記噴出孔を、前記可動リングが最前進した状態で前記固定リング及び基体部を貫通して前記通水孔に連通可能に形成したので、かかる拡径掘削装置の先端側から拡径作業時に水を削孔部内に供給することが出来る。   Since the ejection hole is formed so as to be able to communicate with the water passage hole through the fixed ring and the base portion in a state where the movable ring is most advanced, the water is discharged from the distal end side of the diameter expansion excavator during the diameter expansion operation. Can be fed into the drilling section.

前記基体部の基端側の側面に、基体部の長手方向に長く、且つ前記通水孔に連通するスリットを形成したので、閉鎖時において基体部と拡径ビットとの間の土砂を除去することが出来るため、拡径ビットを確実に完全閉鎖することが出来る。   Since a slit which is long in the longitudinal direction of the base portion and communicates with the water passage hole is formed on the side surface on the base end side of the base portion, earth and sand between the base portion and the diameter expansion bit are removed when closed. Therefore, the expanded bit can be completely closed reliably.

地盤に形成された削孔部内に請求項１〜９のいずれか１項に記載の拡径掘削装置を、地盤に形成された削孔部内に、拡径ビットを閉じた状態で挿入する工程と、削孔部における拡径部位の形成個所で拡径ビットを開く工程と、この状態の拡径掘削装置を回転させながら前後動させることを繰り返して、削孔部の一部を拡径する工程と、を有しているので、かかる工法によれば、削孔部の末端部はもとより、任意位置に大径部位を形成することが出来、杭体の長さを短くすることが可能な削孔部を形成することが出来る等その実用的効果甚だ大である。   A step of inserting the enlarged diameter drilling device according to any one of claims 1 to 9 into the drilled portion formed in the ground in a state where the expanded diameter bit is closed into the drilled portion formed in the ground; The step of expanding the diameter of a part of the hole-drilling part by repeatedly opening the diameter-expansion bit at the formation part of the diameter-expansion part in the hole-drilling part and moving the diameter-expansion excavator in this state while rotating. Therefore, according to such a construction method, it is possible to form a large-diameter portion at an arbitrary position as well as the end portion of the drilling portion, and to reduce the length of the pile body. The practical effect such as being able to form a hole is very large.

本発明に係る拡径掘削装置（実施例１）の拡径ビットを開いた状態を示す側面図である。It is a side view which shows the state which opened the diameter expansion bit of the diameter expansion excavation apparatus (Example 1) which concerns on this invention. 図１の拡径掘削装置の正面図である。It is a front view of the diameter expansion excavator of FIG. 図２のＸ１−Ｘ１断面図である。It is X1-X1 sectional drawing of FIG. 図１の拡径掘削装置の拡径ビットを閉じた状態を示す側面図である。It is a side view which shows the state which closed the diameter expansion bit of the diameter expansion excavation apparatus of FIG. 削孔部内に拡径掘削装置を挿入した状態を示す断面図である。It is sectional drawing which shows the state which inserted the diameter expansion excavator in the drilling part. 削孔部内で拡径掘削装置の拡径ビットを孔壁に当たるまで開いた状態を示す断面図である。It is sectional drawing which shows the state opened until the diameter expansion bit of the diameter expansion excavation apparatus hits a hole wall within a drilling part. 削孔部内で拡径掘削装置の拡径ビットを完全に開いた状態を示す断面図である。It is sectional drawing which shows the state which opened the diameter expansion bit of the diameter expansion excavation apparatus completely in the drilling part. 削孔部内で拡径ビットを開いた拡径掘削装置を進退させた状態を示す断面図である。It is sectional drawing which shows the state which advanced / retreated the diameter expansion excavation apparatus which opened the diameter expansion bit in the drilling part. 拡径ビットを閉じた拡径掘削装置をケーシング内に収容した状態を示す断面図である。It is sectional drawing which shows the state which accommodated the diameter expansion excavation apparatus which closed the diameter expansion bit in the casing. 拡径掘削装置を引き抜いた状態を示す断面図である。It is sectional drawing which shows the state which pulled out the diameter expansion excavation apparatus. 拡径掘削装置による削孔方法を利用した施工例を示す断面図である。It is sectional drawing which shows the construction example using the drilling method by a diameter expansion excavation apparatus. 本発明に係る拡径掘削装置（実施例２）の拡径ビットを閉じた状態を示す側面図である。It is a side view which shows the state which closed the diameter expansion bit of the diameter expansion excavation apparatus (Example 2) which concerns on this invention. 図１２の拡径掘削装置の拡径ビットを開いた状態を示す側面図である。It is a side view which shows the state which opened the diameter expansion bit of the diameter expansion excavation apparatus of FIG. 図１３の正面図である。FIG. 14 is a front view of FIG. 13. 図１４のＸ２−Ｘ２断面図である。It is X2-X2 sectional drawing of FIG. 図１３のＹ−Ｙ断面図である。It is YY sectional drawing of FIG. 図１３のＺ−Ｚ断面図である。It is ZZ sectional drawing of FIG. 固定リング側のストッパーと可動リング側のストッパーの係合状態を示す部分概略斜視図である。It is a partial schematic perspective view which shows the engagement state of the stopper by the side of a fixed ring, and the stopper by the side of a movable ring. 削孔部内に拡径掘削装置を挿入した状態を示す断面図である。It is sectional drawing which shows the state which inserted the diameter expansion excavator in the drilling part. 削孔部内で拡径掘削装置の拡径ビットを開いた状態を示す断面図である。It is sectional drawing which shows the state which opened the diameter expansion bit of the diameter expansion excavation apparatus in the drilling part. 削孔部内で拡径ビットを開いた拡径掘削装置を押し込んだ状態を示す断面図である。It is sectional drawing which shows the state which pushed in the diameter expansion drilling apparatus which opened the diameter expansion bit in the drilling part. 削孔部内で拡径ビットを開いた拡径掘削装置を引いた状態を示す断面図である。It is sectional drawing which shows the state which pulled the diameter expansion excavation apparatus which opened the diameter expansion bit in the drilling part. 削孔部内で拡径掘削装置の拡径ビットを閉じた状態を示す断面図である。It is sectional drawing which shows the state which closed the diameter expansion bit of the diameter expansion excavation apparatus in the drilling part. 拡径掘削装置を引き抜いた状態を示す断面図である。It is sectional drawing which shows the state which pulled out the diameter expansion excavation apparatus. 拡径掘削装置による削孔方法を利用した施工例を示す断面図である。It is sectional drawing which shows the construction example using the drilling method by a diameter expansion excavation apparatus.

以下、本発明を実施するための形態を図面に基づき説明する。
本発明に係る拡径掘削装置にあっては、ボーリングマシン等の削孔機械により地盤に予め形成された削孔部Ｈ内に挿入して該削孔部Ｈを部分的に拡径する、具体的には末端部を拡径するものであって、削孔部Ｈ内に正逆回転可能に挿入される長尺なパイプＰの先端に配設された、削孔部Ｈより小径な基体部１と、該基体部１に設けた複数の開閉可能な拡径ビット２、2a…とを有しており、該拡径ビット２、2a…を閉じた状態で削孔部Ｈ内に挿入可能にすると共に、該削孔部Ｈ内で掘削ビット２、2a…を開いて削孔部Ｈを部分的に拡径可能にしている。
又、基体部１の中央長手方向に通水孔３を形成すると共に、該通水孔３に連通する複数個の噴出孔４、4a…を開口形成している。
そして、この拡径掘削装置を、地盤に形成された削孔部Ｈ内に、拡径ビット２、2a…を閉じた状態で挿入し、削孔部Ｈにおける大径部位Ｈｂの形成個所で拡径ビット２、2a…を開いｔ後、この状態のまま拡径掘削装置を回転させながら前後動させることを繰り返して、削孔部Ｈの一部を拡径し大径部位Ｈｂ、残りを小径部位Ｈａとする様にしている。
以下、詳細に説明する。 Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.
In the diameter-expanded excavator according to the present invention, the hole-drilling part H is partially expanded by inserting the hole-drilling part H into a hole-drilled part H previously formed in the ground by a drilling machine such as a boring machine. Specifically, the base portion having a diameter smaller than that of the drilling portion H, which expands the diameter of the end portion and is disposed at the tip of a long pipe P which is inserted into the drilling portion H so as to be able to rotate forward and backward. 1 and a plurality of openable / closable diameter expanding bits 2, 2 a provided on the base body 1, and can be inserted into the drilled hole H with the diameter expanding bits 2, 2 a. In addition, the excavation bits 2, 2a,...
Further, the water passage hole 3 is formed in the central longitudinal direction of the base portion 1, and a plurality of ejection holes 4, 4 a... Communicating with the water passage hole 3 are formed.
And this diameter-expanded excavator is inserted into the drilling hole H formed in the ground with the diameter-expanding bits 2, 2a, etc. closed, and is expanded at the location where the large-diameter portion Hb in the drilling hole H is formed. After opening the diameter bit 2, 2a, etc., it is repeatedly moved back and forth while rotating the enlarged diameter excavator in this state, and a part of the drilling hole H is enlarged to increase the diameter of the large diameter portion Hb, and the rest is reduced to the diameter. It is set as the site | part Ha.
Details will be described below.

図１〜４は、本発明に係る拡径掘削装置の実施例１の拡径ビットを開いた状態を示す側面図、正面図、図２のＸ１−Ｘ１断面図、図１の拡径掘削装置の拡径ビットを閉じた状態を示す側面図であり、基体部１は略円柱状で上記パイプＰに対し着脱自在とし、先端面中央に突出部５を設け、通水孔３は基端側を基体部１の基端側で開口させると共に、先端側が突出部５に至る様に形成され、２個の噴出孔４、4aを、通水孔３に対し直角且つ突出部５の直径方向に配置して、突出部５の側面で開口する様に形成され、２枚の拡径ビット２、2aを、基体部１の先端面で噴出孔４、4aの延長線上に配置すると共に、開閉可能に軸着し、閉じた状態の拡径ビット２、2aは基体部１の前方で先端どうしが当接し、開いた状態の拡径ビット２、2aは基体部１の軸線に対し直角となる様に基体部１に軸着されている。   1 to 4 are a side view, a front view, a cross-sectional view taken along line X1-X1 of FIG. 2, and a diameter expansion excavator of FIG. FIG. 2 is a side view showing a closed state of the diameter expansion bit, the base portion 1 is substantially cylindrical and can be attached to and detached from the pipe P, and a protruding portion 5 is provided at the center of the distal end surface. Is opened at the base end side of the base portion 1 and the tip end side is formed so as to reach the protruding portion 5, and the two ejection holes 4, 4 a are perpendicular to the water passage hole 3 and in the diameter direction of the protruding portion 5. Arranged and formed so as to open on the side surface of the protruding portion 5, the two enlarged diameter bits 2, 2 a are arranged on the extended line of the ejection holes 4, 4 a on the tip surface of the base portion 1 and can be opened and closed The enlarged diameter bits 2 and 2a in the closed state are in contact with the front ends of the base portion 1, and the enlarged diameter bits 2 and 2a in the opened state are the shafts of the base portion 1. It is pivotally attached to the base portion 1 so as to be perpendicular to the line.

拡径ビット２、2aの表面に突起６、6a…を設け、該突起６、6a…は拡径ビット２、2aが開いた状態で削孔部Ｈより外側に位置し、具体的には、基体部１の先端面の中心に対する等間隔の同心円の夫々に突起６、6a…を１個ずつ配置し、且つ内側から奇数番目の円の突起６、6b、6d、6f、6hが一方の拡径ビット２に、偶数番目の円の突起6a、6c、6e、6gが他方の拡径ビット2aに、拡径ビット２、2aの長手方向に対し斜め方向に直列配置されている。   Protrusions 6, 6 a... Are provided on the surface of the diameter-enlarged bits 2, 2 a, and the protrusions 6, 6 a. One protrusion 6, 6 a... Is arranged on each of concentric circles at equal intervals with respect to the center of the front end surface of the base portion 1, and odd-numbered circular protrusions 6, 6 b, 6 d, 6 f, 6 h from the inside are expanded on one side. On the diameter bit 2, even-numbered circular protrusions 6a, 6c, 6e, 6g are arranged in series on the other diameter expansion bit 2a in an oblique direction with respect to the longitudinal direction of the diameter expansion bits 2, 2a.

基体部１の先端面における突出部５の両側部位に形成された、該突出部５の外周面に至る凹部７、7a内に拡径ビット２、2aの基端部を収容すると共に、ボルト８、8aにより基体部１に開閉可能に取り付けられており、開いた状態の拡径ビット２、2aの背面が凹部７、7aの底面に当接可能にしている。   The base end portions of the diameter-enlarged bits 2 and 2a are accommodated in the concave portions 7 and 7a formed on both side portions of the projecting portion 5 on the distal end surface of the base portion 1 and reaching the outer peripheral surface of the projecting portion 5, and the bolt 8 , 8a are attached to the base portion 1 so as to be openable and closable, and the back surfaces of the opened diameter expanding bits 2 and 2a can contact the bottom surfaces of the recesses 7 and 7a.

尚、基体部１は、先端部位1aと、該先端部位1aより小径な中間部位1bと、上記パイプＰへのジョイント部位1bとを有し、先端部位1aの外側面に溝９、9aを形成し、該溝９、9aは基体部１の先端面に至る様に形成されている。
又、基端部位1bの外周面に、通水孔３に連通する噴出孔10、10a を形成し、該噴出孔10、10a は後方側へ指向する様に傾斜させて形成されている。 The base portion 1 has a tip portion 1a, an intermediate portion 1b having a smaller diameter than the tip portion 1a, and a joint portion 1b to the pipe P, and grooves 9 and 9a are formed on the outer surface of the tip portion 1a. The grooves 9 and 9a are formed so as to reach the front end surface of the base portion 1.
Further, jet holes 10 and 10a communicating with the water passage hole 3 are formed on the outer peripheral surface of the base end portion 1b, and the jet holes 10 and 10a are formed so as to be inclined rearward.

次に、本発明に係る拡径掘削装置の実施例１を使用する削孔工法について説明する。
先ず、拡径ビット４、4a…が完全に閉じた状態の拡径掘削装置を、削孔部Ｈ内に挿設状態のケーシングＣ内に挿入し（図５参照）、次にケーシングＣの末端から削孔部Ｈ内に拡径掘削装置を送り込んだ後、噴出孔４、4aから水を噴出させ拡径ビット２、2aに当てて、該拡径ビット２、2aを、先端が孔壁に当たるまで開かせ（図６参照）、次に拡径掘削装置を更に押し込んで、拡径ビット２、2aを地盤側に食い込ませながら完全に開かせ（図７参照）、次に拡径掘削装置を正回転させながら前後動させることを繰り返して、削孔部Ｈの末端部位を拡径し（図８参照）、次に拡径掘削装置を引き抜くと、ケーシングＣの口縁部に拡径ビット２、2aの背面が当接して該拡径ビット２、2aが徐々に閉じられ、拡径掘削装置がケーシングＣ内に収容され（図９参照）、最後に拡径掘削装置及びケーシングＣを削孔部Ｈから引き抜いて、小径部位Ｈａと大径部位Ｈｂからなる削孔部Ｈを形成する（図１０参照）。 Next, a drilling method using the first embodiment of the diameter expanding excavator according to the present invention will be described.
First, the diameter-expanded excavator with the diameter-expanded bits 4, 4 a... Completely closed is inserted into the casing C inserted in the hole H (see FIG. 5). After the diameter expanding excavator is fed into the drilling hole H, water is ejected from the ejection holes 4 and 4a and applied to the diameter expanding bits 2 and 2a so that the tips of the diameter expanding bits 2 and 2a hit the hole wall. (See Fig. 6), and then push the diameter-expanding drilling device further into it, fully opening it while biting the diameter-expanding bits 2 and 2a into the ground (see Fig. 7). By repeating the forward and backward movement while rotating in the forward direction, the diameter of the end portion of the hole drilling portion H is increased (see FIG. 8), and then when the diameter-expanding excavator is pulled out, , 2a come into contact with each other and the diameter-expanding bits 2 and 2a are gradually closed, and the diameter-expanded excavator is accommodated in the casing C (see FIG. See), and finally pulling the enlarged diameter drilling equipment and casing C from drilling unit H, to form a drilling portion H composed of the small diameter portion Ha and a large diameter portion position Hb (see FIG. 10).

上記拡径工程時に、先ず突起６、6a…で被掘削面に溝を掘って掘削し易くした後に回転進行する拡径ビット２、2aのエッジで徐々に削り取られて大径部位Ｈｂが形成されるため、掘削効率が良好で、而も被掘削面に形成される溝が重ならないため、掘削容易性が更に向上する。   At the time of the above-mentioned diameter expansion process, first, a groove is formed on the surface to be excavated by the protrusions 6, 6a, etc., and then the edge of the diameter expansion bits 2 and 2a that rotate is gradually scraped off to form a large diameter portion Hb. Therefore, excavation efficiency is good, and since the grooves formed on the excavated surface do not overlap, excavation easiness is further improved.

拡径掘削装置の前後動の際に、後退時には障害があれば拡径ビット２、2aは自動的に閉じ、前進時には噴出孔４、4aから噴出させた水の勢いにより拡径ビット２、2aの先端が拡径孔壁部に当たり更に前進することで完全に開く。   During forward and backward movement of the diameter expansion drilling device, if there is a failure during retraction, the diameter expansion bits 2 and 2a are automatically closed. When the tip of the nozzle hits the enlarged-diameter hole wall portion and further advances, it opens completely.

噴出孔４、4a、10、10a から水を噴出させることで、この水と共に削り取られた掘削土砂が溝９、9aからケーシングＣ内を経て外部に排出される。   By ejecting water from the ejection holes 4, 4 a, 10, 10 a, excavated earth and sand shaved off together with the water is discharged from the grooves 9, 9 a through the casing C to the outside.

図１２〜１５図１２〜１５は、本発明に係る拡径掘削装置の実施例２の拡径ビットを閉じた状態を示す側面図、拡径掘削装置の拡径ビットを開いた状態を示す側面図、図１３の正面図、図１４のＸ２−Ｘ２断面図であり、基体部１は丸棒状で上記パイプＰに対し着脱自在とし、３個の拡径ビット２、2a、2bを基体部１の外周方向に等間隔に配置し、該拡径ビット２、2a、2bは屈伸可能で、一端を基体部１の先端部に外嵌された固定リング11に、他端を基体部１のにおける固定リング11より基端側に外嵌された、基体部１の軸芯方向に移動可能な可動リング12に夫々軸着されている。   FIGS. 12-15 FIGS. 12-15 are side views showing a state in which the diameter expansion bit of Example 2 of the diameter expansion excavation apparatus according to the present invention is closed, and a side surface showing a state in which the diameter expansion bit of the diameter expansion excavation apparatus is opened. FIG. 13 is a front view of FIG. 13 and a cross-sectional view taken along line X2-X2 of FIG. 14. The base portion 1 has a round bar shape and is attachable to and detachable from the pipe P, and three enlarged diameter bits 2, 2a and 2b are provided. The diameter expansion bits 2, 2 a, 2 b can be bent and extended, one end is fixed to the fixing ring 11 fitted on the tip of the base portion 1, and the other end of the base portion 1. The movable ring 12 is fitted on the movable ring 12 which is fitted on the base end side of the fixed ring 11 and is movable in the axial direction of the base portion 1.

基体部１は、内部を通水孔３とする金属製の中空丸棒とし、少なくとも可動リング12の移動範囲の部位にネジ部13を形成している。   The base portion 1 is a metal hollow round bar having a water passage 3 therein, and a screw portion 13 is formed at least in a region where the movable ring 12 moves.

固定リング11は、金属製の丸筒で先端側に設けた蓋部14の中央に、基体部１の先端に一体形成された軸棒15を貫通させて、基体部１に対する位置を固定し、且つ基体部１に対し正逆回転自在としている。
固定リング11に、基体部１の先端面より先に突出する固定突起16、16a …を設け、該固定突起16、16a …は、蓋部14の前面に一体化されている。 The fixing ring 11 is a metal round tube, and a shaft bar 15 integrally formed at the tip of the base body 1 is passed through the center of the lid part 14 provided on the tip side to fix the position relative to the base body 1. In addition, it can rotate forward and backward with respect to the base body 1.
The fixing ring 11 is provided with fixing protrusions 16, 16 a... That protrude beyond the front end surface of the base body 1, and the fixing protrusions 16, 16 a.

可動リング12は、金属製の丸筒で、内周面に基体部１のネジ部13に噛み合う螺条17を形成している。   The movable ring 12 is a metal round tube, and a thread 17 that meshes with the screw portion 13 of the base portion 1 is formed on the inner peripheral surface.

拡径ビット２、2a、2bは、基体部１の外周方向に等間隔に配置し、各拡径ビット２、2a、2bは２本のビット部材18、18a で構成され、該ビット部材18、18a の基端部を固定リング11と可動リング12に起伏可能に軸着すると共に、ビット部材18、18a の先端部同士を軸着している。   The enlarged diameter bits 2, 2a, 2b are arranged at equal intervals in the outer peripheral direction of the base body 1, and each enlarged diameter bit 2, 2a, 2b is composed of two bit members 18, 18a. The base end portion of 18a is pivotally attached to the fixed ring 11 and the movable ring 12, and the tip portions of the bit members 18, 18a are axially attached.

各拡径ビット２、2a、2bにおけるビット部材18、18a の軸着部より先端部位を尖端部19、19a とし、具体的には、ビット部材18、18a は、各ビット部材18、18a の先端側を突出部位20、20a と切欠部位21、21a を交互に有する櫛歯状に形成し噛み合わせて軸着され、突出部位20、20a の先端部に基端側且つ内方側への傾斜面22、22a を形成して尖端部19、19a とし、切欠部位21、21a に、突出部位20、20a の傾斜面22、22a の受承傾斜面23、23a を形成している。   The tip portions of the diameter-enlarged bits 2, 2a and 2b are pointed portions 19 and 19a from the axially attached portions of the bit members 18 and 18a. Specifically, the bit members 18 and 18a are the tips of the bit members 18 and 18a. The side is formed in a comb-like shape having protruding portions 20, 20a and notch portions 21, 21a alternately, and meshed with each other, and is pivotally attached to the distal end of the protruding portions 20, 20a. 22 and 22a are formed as the tip portions 19 and 19a, and the receiving inclined surfaces 23 and 23a of the inclined surfaces 22 and 22a of the projecting portions 20 and 20a are formed in the notch portions 21 and 21a.

各拡径ビット２、2a、2bにおけるビット部材18、18a の基端側内面に、各拡径ビット２、2a、2bが完全に閉じた状態で固定リング11と可動リング12の該側面に当接するストッパ24、24a を固設している。   The diameter-enlarged bits 2, 2a, 2b are in contact with the side surfaces of the fixed ring 11 and the movable ring 12 with the diameter-enlarged bits 2, 2a, 2b completely closed on the inner surface of the base end side of the bit members 18, 18a of the diameter-enlarged bits 2, 2a, 2b. Stopping stoppers 24 and 24a are fixed.

図１６に示す様に、固定リング11の後部に円筒状のスペーサ25を有し、噴出孔４、4aを、可動リング12が最前進した状態でスペーサ25及び基体部１を貫通して通水孔３に連通可能に形成している。   As shown in FIG. 16, a cylindrical spacer 25 is provided at the rear portion of the fixed ring 11, and water is passed through the ejection holes 4 and 4a through the spacer 25 and the base portion 1 with the movable ring 12 being most advanced. It is formed so as to be able to communicate with the hole 3.

図１７に示す様に、基体部１の基端側の側面に、該基体部１の長手方向に長く、且つ通水孔３に連通するスリット26、26a を形成している。   As shown in FIG. 17, slits 26, 26 a that are long in the longitudinal direction of the base body 1 and communicate with the water passage hole 3 are formed on the side surface on the base end side of the base body 1.

図１８に示す様に、固定リング11及び可動リング12に、可動リング12が最前進した状態で基体部１に対する回転を防止可能なストッパー27、28を設けている。   As shown in FIG. 18, the fixed ring 11 and the movable ring 12 are provided with stoppers 27 and 28 that can prevent rotation with respect to the base portion 1 when the movable ring 12 is in the most advanced state.

又、基体部１は、基体部本体30と、該基体部本体30の基端側に一体形成された、パイプＰとのジョイント部31とを有している。   The base portion 1 includes a base portion main body 30 and a joint portion 31 with the pipe P that is integrally formed on the base end side of the base portion main body 30.

次に、本発明に係る拡径掘削装置の実施例２を使用する削孔工法について説明する。
先ず、拡径ビット２、2a、2bが完全に閉じた状態の拡径掘削装置を削孔部Ｈに、その先端が削孔部Ｈの末端に当たり固定突起16、16a …が末端面に差し込まれ固定リング11が固定されるまで挿入し（図１９参照）、次に基体部１を正回転させ可動リング12を前進させて、拡径ビット２、2a、2bにおける２本のビット部材18、18a を起こして拡径ビット２、2a、2bを徐々に屈曲させて開き、拡径ビット２、2a、2bにおける２本のビット部材18、18a を最大に起こして、拡径ビット２、2a、2bを完全に開いた状態にし（図２０参照）、次に基体部１を正回転させながら拡径掘削装置をケーシングＣと共に前後動させることを繰り返して、削孔部Ｈの末端部位を拡径し（図２１、２２参照）、次に基体部１を逆回転させ可動リング12を後退させて、屈曲状態の拡径ビット２、2a、2bにおける２本のビット部材18、18a を徐々に倒して閉じ、可動リング12を最後退位置まで後退させて拡径ビット２、2a、2bにおける２本のビット部材18、18a を真っ直ぐな状態にし（図２３参照）、最後に拡径掘削装置を削孔部Ｈから引き抜いて、小径部位Ｈａと大径部位Ｈｂからなる削孔部Ｈを形成する（図２４参照）。 Next, a drilling method using the second embodiment of the diameter expanding excavator according to the present invention will be described.
First, the diameter-extended drilling device with the diameter-enlarged bits 2, 2a, 2b completely closed is brought into the drilling part H, the tip of the drilling part H hits the end of the drilling part H, and the fixed projections 16, 16a. The fixing ring 11 is inserted until it is fixed (see FIG. 19), and then the base 1 is rotated forward to move the movable ring 12 forward, so that the two bit members 18, 18a in the enlarged diameter bits 2, 2a, 2b are obtained. The diameter-expanded bits 2, 2a, 2b are gradually bent and opened, and the two bit members 18, 18a in the diameter-expanded bits 2, 2a, 2b are maximally raised to expand the diameter-expanded bits 2, 2a, 2b. Is opened completely (see FIG. 20), and then the diameter expanding excavator is moved back and forth together with the casing C while the base body 1 is rotated forward to increase the diameter of the end portion of the drilled hole H. (Refer to FIGS. 21 and 22) Next, the base portion 1 is rotated in the reverse direction, and the movable ring 12 is retracted to expand the bent state. The two bit members 18 and 18a in the nuts 2, 2a and 2b are gradually tilted and closed, and the movable ring 12 is retracted to the last retracted position, and the two bit members 18 in the enlarged diameter bits 2, 2a and 2b, 18a is set in a straight state (see FIG. 23), and finally, the diameter-excavated excavator is pulled out from the hole portion H to form a hole portion H composed of a small diameter portion Ha and a large diameter portion Hb (see FIG. 24).

上記拡径ビット２、2a、2bの開き工程（図２０参照）において、拡径ビット２、2a、2bが完全に開いた状態となれば、基体部１を正回転させてもそれ以上屈曲せず、基体部１と共に固定リング11、可動リング12及び拡径ビット２、2a、2bも回転して、拡径ビット２、2a、2bの屈曲部位で削孔部Ｈの孔壁を削り取ることが可能になり、この完全に開いた状態は、可動リング12がスペーサ25に当接した時点の状態のことである。   In the step of opening the diameter-enlarged bits 2, 2a, 2b (refer to FIG. 20), if the diameter-enlarged bits 2, 2a, 2b are completely opened, the base portion 1 can be bent further even if it is rotated forward. First, the fixed ring 11, the movable ring 12, and the enlarged diameter bits 2, 2a, 2b are rotated together with the base part 1, and the hole wall of the drilled portion H is scraped off at the bent portions of the enlarged diameter bits 2, 2a, 2b. This fully open state is the state when the movable ring 12 contacts the spacer 25.

上記拡径工程（図２１、２２参照）において、屈曲状態の各拡径ビット２、2a、2bの屈曲部位に、ビット部材18、18a の尖端部19、19a が突出するため、削孔部Ｈの孔壁を削り取り易くなる。   In the diameter expansion step (see FIGS. 21 and 22), the sharpened portions 19 and 19a of the bit members 18 and 18a protrude from the bent portions of the diameter-expanded bits 2, 2a and 2b in the bent state, so It becomes easy to scrape off the hole wall.

完全に閉じた状態の拡径ビット２、2a、2bは、ストッパ24、24a が固定リング11と可動リング12に当接するか、ビット部材18、18a における突出部位20、20a の傾斜面22、22a が切欠部位21、21a の受承傾斜面23、23a に当接することで、内側へ折れない様に成っているため、完全に閉じた状態の拡径ビット２、2a、2bを開く際に確実に外側へ屈曲させることが可能となる。   The diameter-enlarged bits 2, 2a, 2b in the completely closed state are such that the stoppers 24, 24a abut against the fixed ring 11 and the movable ring 12, or the inclined surfaces 22, 22a of the protruding portions 20, 20a of the bit members 18, 18a. Since it does not fold inward by abutting against the receiving inclined surfaces 23 and 23a of the notch portions 21 and 21a, it is sure to open the diameter-enlarged bits 2, 2a and 2b in the completely closed state. Can be bent outward.

尚、拡径ビット２、2a、2bを開閉する場合、単に挿入した状態で拡径ビット２、2a、2bが孔壁に当たって固定リング11及び可動リング12が基体部１と共に回転することが抑止されることから、基体部１を単に正逆回転させれば、拡径ビット２、2a、2bは開閉するが、図１９、２０と図２２、２３に示す様に、固定リング11の固定突起16、16a …を末端面に差し込んで固定リング11を固定すればより確実に行える。
又、図１９〜２３には、削孔部ＨにケーシングＣが挿入され、拡径作業時に拡径掘削装置と共に前後動させているが、無くても良い。 When opening and closing the diameter-enlarged bits 2, 2 a, 2 b, it is possible to prevent the diameter-enlarged bits 2, 2 a, 2 b from striking against the hole wall and simply rotating the fixed ring 11 and the movable ring 12 together with the base portion 1. Therefore, if the base body 1 is simply rotated forward and reverse, the diameter-expanding bits 2, 2a, 2b open and close, but as shown in FIGS. 19, 20 and 22, 23, the fixing protrusion 16 of the fixing ring 11 , 16a... Are inserted into the end face and the fixing ring 11 is fixed.
In FIGS. 19 to 23, the casing C is inserted into the drilled hole H and moved back and forth together with the diameter expanding excavator during the diameter expanding operation.

本発明に係る拡径掘削装置により形成した削孔部内にグラウト材を注入して杭体を形成する工法の一例として、例えば図１１、２５に示す様な、プレキャストコンクリート板Ｗによる斜面安定工法があり、斜面Ｓに設置したプレキャスト板Ｗの裏面と斜面Ｓとの隙間に裏込め層Ａを形成し、各プレキャスト板Ｗ、裏込め層Ａを貫通して斜面Ｓ側に形成した削孔部Ｈ内に棒状補強材Ｒを挿入しグラウト材Ｇを注入し、該グラウト材Ｇを養生硬化させて杭体Ｔとした後に、棒状補強材Ｒのプレキャスト板Ｗからの突端部にナット螺嵌緊締して斜面Ｓを補強するのであるが、この工法における削孔工程で拡径掘削装置を使用して削孔部Ｈの末端部を大径部位としている。   As an example of a method for forming a pile body by injecting a grout material into a drilling portion formed by a diameter expanding excavator according to the present invention, for example, a slope stabilization method using a precast concrete plate W as shown in FIGS. Yes, a backfill layer A is formed in the gap between the back surface of the precast plate W installed on the slope S and the slope S, and a drilling portion H formed on the slope S side through each precast plate W and the backfill layer A After inserting the rod-shaped reinforcing material R and injecting the grout material G, curing and hardening the grout material G to form the pile body T, the nut-fitting and tightening of the rod-shaped reinforcing material R to the protruding end portion from the precast plate W is performed. The slope S is reinforced, and the end portion of the drilled portion H is made a large-diameter portion by using a diameter expanding excavator in the drilling step in this construction method.

尚、本発明に係る拡径掘削装置を使用する工法は上記のものに限定されず、線材や棒材を挿入しグラウト材を注入する所謂アンカー工法の削孔工程で使用するのが一般的であるが、要するに地盤に形成する削孔部の一部を拡径して大径部位を形成する必要がある工法であれば使用可能である。   In addition, the construction method using the diameter-expanded excavator according to the present invention is not limited to the above-described one, and is generally used in a drilling process of a so-called anchor construction method in which a wire or a rod is inserted and a grout material is injected. In short, any method can be used as long as it is necessary to enlarge a part of a hole formed in the ground to form a large diameter portion.

又、本発明に係る拡径掘削装置における基体部１は、上記実施例１、２の様にパイプＰに対し着脱自在であるのがメンテナンス上好ましいが、パイプＰに対し一体化されていても良い。   In addition, it is preferable for maintenance that the base portion 1 in the diameter expanding excavator according to the present invention is detachable from the pipe P as in the first and second embodiments. good.

１ 基体部
２、2a、2b 拡径ビット
３ 通水孔
４、4a… 噴出孔
５ 突出部
６、6a… 突起
11 固定リング
12 可動リング
13 ネジ部
16、16a … 固定突起
17 螺条
18、18a ビット部材
19、19a 尖端部
26 スリット
Ｈ 削孔部 DESCRIPTION OF SYMBOLS 1 Base part 2, 2a, 2b Diameter expansion bit 3 Water flow hole 4, 4a ... Injection hole 5 Protrusion part 6, 6a ... Protrusion
11 Retaining ring
12 Movable ring
13 Screw part
16, 16a… Fixing protrusion
17 Screw
18, 18a Bit member
19, 19a Tip
26 Slit H Drilling part

Claims (10)

予め形成された所定長さの削孔部の一部を拡径する拡径掘削装置であって、パイプの先端に配設された基体部と、該基体部に取り付けられた複数の開閉可能な拡径ビットを有し、前記基体部の中央長手方向に通水孔を形成すると共に、該通水孔に連通して削孔部内に水を噴出可能な噴出孔を有し、前記拡径ビットを閉じた状態で削孔部内に挿入可能にすると共に、該削孔部内で掘削ビットを開いて削孔部を部分的に拡径可能にしたことを特徴とする拡径掘削装置。   A diameter-excavating apparatus for expanding a part of a predetermined length of a drilled hole, a base part disposed at a tip of a pipe, and a plurality of openable / closable parts attached to the base part The diameter-enlarged bit has a diameter-enlarged bit, a water-permeable hole is formed in the central longitudinal direction of the base portion, and an ejection hole that communicates with the water-flow hole and is capable of ejecting water into the drilled portion. A diameter expanding excavator characterized in that it can be inserted into a drilling portion in a closed state, and the drilling bit is opened in the drilling portion to partially expand the drilling portion. 前記基体部は略円柱状で、先端面中央に突出部を設け、前記通水孔は基端側を前記基体部の基端側で開口させると共に、先端側が前記突出部に至る様に形成され、２個の前記噴出孔を、前記突出部の直径方向に配置し側面で開口する様に形成され、２枚の前記拡径ビットを、前記基体部の先端面で前記噴出孔の延長線上に配置し開閉可能に軸着したことを特徴とする請求項１記載の拡径掘削装置。   The base portion is substantially cylindrical, and a protrusion is provided in the center of the tip surface. The water passage hole is formed so that the base end side is opened at the base end side of the base portion, and the tip end side reaches the protrusion. Two ejection holes are arranged in the diametrical direction of the projecting portion and are formed so as to open on the side surface, and the two enlarged diameter bits are placed on the extension line of the ejection hole at the distal end surface of the base portion. The diameter-extended excavator according to claim 1, wherein the excavator is arranged and attached so as to be openable and closable. 拡径ビットの表面に突起を設け、該突起は拡径ビットが開いた状態で削孔部より外側に位置させたことを特徴とする請求項２記載の拡径掘削装置。   3. A diameter expanding excavator according to claim 2, wherein a protrusion is provided on the surface of the diameter expanding bit, and the protrusion is positioned outside the drilling portion in a state where the diameter expanding bit is opened. 前記突起の夫々を、基体部の先端面の中心に対する等間隔の同心円の夫々に１個ずつ配置したことを特徴とする請求項３記載の拡径掘削装置。   4. The diameter-expanded excavator according to claim 3, wherein each of the protrusions is arranged in a concentric circle at regular intervals with respect to the center of the front end surface of the base portion. 前記基体部を中空丸棒状としてこの中空部を前記通水孔とし、前記噴出孔を基体部の先端側に形成し、２本のビット部材の先端同士を軸着して形成した屈伸可能な拡径ビットを、前記基体部の外周方向に等間隔に配置すると共に、一方のビット部材の基端部を、基体部の先端部に外嵌された固定リングに、他方のビット部材の基端部を、基体部の中間部に外嵌された可動リングに軸着し、前記基体部の外周面における少なくとの前記可動リングの移動範囲の部位にネジ溝を形成すると共に、該ネジ溝に噛み合う螺条を前記可動リングの内周面に形成したことを特徴とする請求項１記載の拡径掘削装置。   The base portion is formed as a hollow round bar, the hollow portion is used as the water passage hole, the ejection hole is formed on the tip end side of the base portion, and the tip portions of the two bit members are axially attached to each other. The radial bits are arranged at equal intervals in the outer peripheral direction of the base portion, and the base end portion of one bit member is fixed to the fixing ring externally fitted to the tip end portion of the base portion, and the base end portion of the other bit member Is pivotally attached to a movable ring that is externally fitted to the intermediate portion of the base portion, and a screw groove is formed at a portion of the outer peripheral surface of the base portion at least within the movable range of the movable ring, and meshes with the screw groove. The diameter-extended excavator according to claim 1, wherein a thread is formed on an inner peripheral surface of the movable ring. 前記固定リングに、前記基体部先端面より先に突出する固定突起を設けたことを特徴とする請求項５記載の拡径掘削装置。   The diameter expansion excavation device according to claim 5, wherein the fixing ring is provided with a fixing protrusion that protrudes ahead of the tip surface of the base portion. 前記２本のビット部材の先端に尖端部を形成したことを特徴とする請求項５又は６記載の拡径掘削装置。   The diameter-extended excavator according to claim 5 or 6, wherein a tip portion is formed at the tip of the two bit members. 前記噴出孔を、前記可動リングが最前進した状態で前記固定リング及び基体部を貫通して前記通水孔に連通可能に形成したことを特徴とする請求項５、６又は７記載の拡径掘削装置。   8. The diameter expansion according to claim 5, wherein the ejection hole is formed so as to be able to communicate with the water passage hole through the fixed ring and the base portion in a state where the movable ring is most advanced. Drilling rig. 前記基体部の基端側の側面に、基体部の長手方向に長く、且つ前記通水孔に連通するスリットを形成したことを特徴とする請求項８記載の拡径掘削装置。   The diameter-expanded excavator according to claim 8, wherein a slit that is long in a longitudinal direction of the base portion and communicates with the water passage hole is formed on a side surface on a base end side of the base portion. 請求項１、２、３、４、５、６、７、８又は９のいずれか１項に記載の拡径掘削装置を、地盤に形成された削孔部内に、拡径ビットを閉じた状態で挿入する工程と、削孔部における拡径部位の形成個所で拡径ビットを開く工程と、この状態の拡径掘削装置を回転させながら前後動させることを繰り返して、削孔部の一部を拡径する工程と、を有していることを特徴とする削孔方法。   The state in which the diameter expansion bit is closed in the hole drilling part formed in the ground in the diameter expansion excavation apparatus according to any one of claims 1, 2, 3, 4, 5, 6, 7, 8, or 9. A part of the hole drilling part by repeating the step of inserting in the drilling step, the step of opening the diameter expanding bit at the formation part of the hole expanding part in the hole drilling part, and the forward and backward movement while rotating the diameter expanding excavator in this state. And a step of expanding the diameter.

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