JP7015090B2

JP7015090B2 - Drilling rod with deformation detector

Info

Publication number: JP7015090B2
Application number: JP2018043192A
Authority: JP
Inventors: 好伸木谷; 隆男酒井; 茂樹北岡; 茂治郎清水
Original assignee: Mitani Sekisan Co Ltd
Current assignee: Mitani Sekisan Co Ltd
Priority date: 2018-03-09
Filing date: 2018-03-09
Publication date: 2022-02-02
Anticipated expiration: 2038-03-09
Also published as: JP2019157434A

Description

本発明は、既製杭などを埋設する抗穴を掘削するための変形検出器付き掘削ロッドに関する。 The present invention relates to an excavation rod with a deformation detector for excavating an anti-hole for burying a ready-made pile or the like.

抗穴を掘削するための掘削ロッドは特許文献１に記載されている。同文献の掘削ロッドは、掘削ヘッドと、端部に掘削ヘッドが取り付けられるロッド本体と、を有する。掘削ロッドにより杭穴を設ける際には、地上に配置した駆動装置によってロッド本体を当該ロッド本体の軸線回りに回転させて掘削ヘッドにより地面を掘削する。ロッド本体は、筒状である。ロッド本体は、その中空部分に、掘削した杭穴にセメントミルクを流し込むための流通管を同軸に備える場合がある。 An excavation rod for excavating a hole is described in Patent Document 1. The excavation rod of the same document has an excavation head and a rod body to which the excavation head is attached to an end. When a pile hole is provided by an excavation rod, the rod body is rotated around the axis of the rod body by a drive device arranged on the ground, and the ground is excavated by an excavation head. The rod body is tubular. The rod body may be coaxially provided with a flow pipe for pouring cement milk into the excavated pile hole in the hollow portion thereof.

特開２０１６－２２３０８０号公報Japanese Unexamined Patent Publication No. 2016-22380

掘削時に掘削ロッドにかかるトルクに関しては計測していないため、トルクが過剰となるとロッド本体に撓みや捩じれなどの変形が発生し、掘削ロッドの破損を招く可能性があった。 Since the torque applied to the excavation rod during excavation is not measured, if the torque is excessive, the rod body may be deformed such as bending or twisting, which may lead to damage to the excavation rod.

以上の問題点に鑑みて、本発明の課題は、ロッド本体の変形を検出できる掘削ロッドを提供することにある。 In view of the above problems, an object of the present invention is to provide an excavation rod capable of detecting deformation of the rod body.

上記課題を解決するために、本発明は、掘削ヘッドと、端部に前記掘削ヘッドが取り付けられた筒状のロッド本体と、を有し、前記ロッド本体を回転させて前記掘削ヘッドにより地面に抗穴を掘削する掘削ロッドにおいて、前記ロッド本体の内壁面に取り付けられて当該ロッド本体の変形を検出する変形検出器を有し、前記変形検出器は、前記内壁面から内周側に離間する位置を前記ロッド本体の軸線方向に延びる計測ロッドと、前記内壁面に固定された固定部材側固定部と、前記固定部材側固定部よりも内周側で前記計測ロッドが固定された計測ロッド固定部と、を有する固定部材と、前記内壁面に固定された支持部材側固定部と、前記支持部材側固定部よりも内周側で前記計測ロッドを当該計測ロッドの計測ロッド軸線方向に移動可能かつ当該ロッド軸線回りに回転可能に支持する計測ロッド支持部と、を有する支持部材と、を備え、前記計測ロッド固定部から前記軸線方向に離間する移動検出位置で前記内壁面と前記計測ロッドとが前記計測ロッド軸線方向で相対移動する移動量を検出する移動量検出器と、前記計測ロッド固定部から前記軸線方向に離間する回転検出位置で前記内壁面と前記計測ロッドとが前記計測ロッド軸線回りで相対回転する回転量を検出する回転量検出器と、を備えることを特徴とする。 In order to solve the above problems, the present invention has an excavation head and a tubular rod body to which the excavation head is attached at an end, and the rod body is rotated to be brought to the ground by the excavation head. An excavation rod for excavating a hole has a deformation detector attached to an inner wall surface of the rod body to detect deformation of the rod body, and the deformation detector is separated from the inner wall surface to the inner peripheral side. A measuring rod whose position extends in the axial direction of the rod body, a fixing member side fixing portion fixed to the inner wall surface, and a measuring rod fixing portion to which the measuring rod is fixed on the inner peripheral side of the fixing member side fixing portion. The measurement rod can be moved in the direction of the measurement rod axis of the measurement rod on the inner peripheral side of the fixing member having the portion, the support member side fixing portion fixed to the inner wall surface, and the support member side fixing portion. A support member having a measuring rod support portion that rotatably supports the rod axis around the rod axis, and the inner wall surface and the measuring rod at a movement detection position separated from the measuring rod fixing portion in the axial direction. The movement amount detector that detects the movement amount that moves relative to the measurement rod axis direction, and the inner wall surface and the measurement rod at the rotation detection position that is separated from the measurement rod fixing portion in the axis direction are the measurement rod axis line. It is characterized by including a rotation amount detector that detects a rotation amount that rotates relative to each other.

本発明によれば、ロッド本体には当該ロッド本体の変形を検出する変形検出器が取り付けられている。変形検出器は、ロッド本体の内周壁の内側を軸線方向に延びる計測ロッドを備える。また、計測ロッドは、計測ロッド軸線方向の一部分が固定部材を介してロッド本体（内壁面）に固定されている。従って、掘削ロッドに過剰なトルクが付与されてロッド本体が撓んだ場合には、計測ロッドとロッド本体との接続部となる固定部材の計測ロッド固定部から軸線方向に離間する移動検出位置において、計測ロッドとロッド本体（内周面）との軸線方向への相対移動を検出できる。また、掘削ロッドに過剰なトルクが付与されてロッド本体が捩じれた場合には、計測ロッドとロッド本体との接続部となる固定部材の計測ロッド固定部から軸線方向に離間する回転検出位置において、計測ロッドとロッド本体（内周面）との軸線回りの相対回転を検出できる。従って、変形検出器は、移動検出位置において計測ロッドとロッド本体（内周面）とが相対移動した移動量と、回転検出位置において計測ロッドとロッド本体（内周面）とが相対回転した回転量と、に基づいて、ロッド本体が撓んで捩じれる変形量を取得できる。ここで、変形検出器は筒状のロッド本体の内周側に位置するので、ロッド本体によって外部から保護される。従って、掘削時に、変形検出器が破損することがない。 According to the present invention, a deformation detector for detecting the deformation of the rod body is attached to the rod body. The deformation detector includes a measuring rod extending in the axial direction inside the inner peripheral wall of the rod body. Further, a part of the measuring rod in the axial direction of the measuring rod is fixed to the rod body (inner wall surface) via a fixing member. Therefore, when excessive torque is applied to the excavation rod and the rod body bends, at the movement detection position separated from the measurement rod fixing part of the fixing member which is the connection part between the measurement rod and the rod body in the axial direction. , The relative movement of the measuring rod and the rod body (inner peripheral surface) in the axial direction can be detected. In addition, when excessive torque is applied to the excavation rod and the rod body is twisted, at the rotation detection position separated from the measurement rod fixing part of the fixing member which is the connection part between the measurement rod and the rod body in the axial direction. Relative rotation around the axis between the measuring rod and the rod body (inner peripheral surface) can be detected. Therefore, in the deformation detector, the amount of movement in which the measuring rod and the rod body (inner peripheral surface) move relative to each other at the movement detection position and the rotation in which the measuring rod and the rod body (inner peripheral surface) rotate relative to each other at the rotation detection position. Based on the amount, the amount of deformation in which the rod body is bent and twisted can be obtained. Here, since the deformation detector is located on the inner peripheral side of the tubular rod body, it is protected from the outside by the rod body. Therefore, the deformation detector is not damaged during excavation.

本発明において、前記内壁面に固定されて前記軸線方向に延びる長尺状のベース部材を有し、前記固定部材側固定部および前記支持部材側固定部は、前記ベース部材に固定されて、前記ベース部材を介して、前記内壁面に固定されていることが望ましい。このようにすれば、固定部材および支持部材をロッド本体の内壁面に直接固定する場合と比較して、変形検出器をロッド本体の内周側に設置することが容易となる。 In the present invention, there is a long base member fixed to the inner wall surface and extending in the axial direction, and the fixing member side fixing portion and the support member side fixing portion are fixed to the base member and described as described above. It is desirable that the inner wall surface is fixed to the inner wall surface via the base member. In this way, it becomes easier to install the deformation detector on the inner peripheral side of the rod body as compared with the case where the fixing member and the support member are directly fixed to the inner wall surface of the rod body.

本発明において、前記移動量検出器は、前記計測ロッドおよび前記ベース部材の一方に固定された移動量検出用磁石と、他方に固定された移動量検出用磁気センサとを備え、前記回転量検出器は、前記計測ロッドおよび前記ベース部材の一方に固定された回転量検出用磁石と、他方に固定された回転量検出用磁気センサとを備えるものとすることができる。このようにすれば、移動量検出器は、計測ロッドとロッド本体（内周面）とが相対移動する移動量を非接触で検出できる。また、移動量検出器は計測ロッドとロッド本体（内周面）とが相対回転する回転量を非接触で検出できる。従って、ロッド本体に過大な撓みや捩じれが発生した場合でも移動量検出器や回転量検出器が破損することがない。 In the present invention, the movement amount detector includes a movement amount detection magnet fixed to one of the measurement rod and the base member, and a movement amount detection magnetic sensor fixed to the other, and the rotation amount detection. The device may include a rotation amount detection magnet fixed to one of the measurement rod and the base member, and a rotation amount detection magnetic sensor fixed to the other. In this way, the movement amount detector can detect the movement amount in which the measuring rod and the rod body (inner peripheral surface) move relative to each other in a non-contact manner. Further, the movement amount detector can detect the amount of rotation in which the measuring rod and the rod body (inner peripheral surface) rotate relative to each other in a non-contact manner. Therefore, even if the rod body is excessively bent or twisted, the movement amount detector and the rotation amount detector will not be damaged.

本発明において、前記計測ロッド固定部と前記移動検出位置との間の第２の移動検出位置で前記内壁面と前記計測ロッドとが前記計測ロッド軸線方向で相対移動する第２の移動量を検出する第２の前記移動量検出器と、前記計測ロッド固定部と前記回転検出位置との間の第２の回転検出位置で前記内壁面と前記計測ロッドとが前記計測ロッド軸線回りで相対回転する第２の回転量を検出する第２の前記回転量検出器と、を備えることが望ましい。このようにすれば、計測ロッドとロッド本体との相対的な移動量および回転量を異なる２つの感度で検出できる。すなわち、ロッド本体が撓んだ場合の移動量は、固定部材の計測ロッド固定部から移動検出位置までの軸線方向の距離の長さに比例して大きくなる。従って、移動検出位置よりも計測ロッド固定部からの距離が短い第２の移動検出位置では、掘削ロッドに過大な負荷が加わってロッド本体が撓んだ場合に発生するロッド本体と計測ロッドとの大きな相対移動を検出できる。一方、第２の移動検出位置よりも計測ロッド固定部からの距離が長い移動検出位置では、掘削ロッドに加わる負荷が小さくて、ロッド本体の撓みが小さい場合（ロッド本体と計測ロッドとの相対移動が小さい場合）でも、その移動量を検出できる。同様に、ロッド本体が捩じれた場合の回転量は、固定部材の計測ロッド固定部から回転検出位置までの軸線方向の距離の長さに比例して大きくなる。従って、回転検出位置よりも計測ロッド固定部からの距離が短い第２の回転検出位置では、掘削ロッドに過大な負荷が加わってロッド本体の捩じれが大きい場合に発生するロッド本体と計測ロッドとの大きな相対回転を検出できる。一方、第２の回転検出位置よりも計測ロッド固定部からの距離が長い回転検出位置では、掘削ロッドに加わる負荷が小さくてロッド本体の捩じれが小さい場合（ロッド本体と計測ロッドとの相対回転が小さい場合）でも、その回転量を検出できる。 In the present invention, the second movement amount in which the inner wall surface and the measurement rod move relative to each other in the axial direction of the measurement rod is detected at the second movement detection position between the measurement rod fixing portion and the movement detection position. At the second rotation detection position between the second movement amount detector and the measurement rod fixing portion and the rotation detection position, the inner wall surface and the measurement rod rotate relative to each other around the measurement rod axis. It is desirable to include the second rotation amount detector for detecting the second rotation amount. In this way, the relative movement amount and rotation amount between the measuring rod and the rod body can be detected with two different sensitivities. That is, the amount of movement when the rod body is bent increases in proportion to the length of the distance in the axial direction from the measurement rod fixing portion of the fixing member to the movement detection position. Therefore, in the second movement detection position where the distance from the measurement rod fixing portion is shorter than the movement detection position, the rod body and the measurement rod generated when the rod body bends due to an excessive load applied to the excavation rod. Large relative movement can be detected. On the other hand, at the movement detection position where the distance from the measurement rod fixing portion is longer than the second movement detection position, the load applied to the excavation rod is small and the bending of the rod body is small (relative movement between the rod body and the measurement rod). Even if is small), the amount of movement can be detected. Similarly, the amount of rotation when the rod body is twisted increases in proportion to the length of the axial distance from the measurement rod fixing portion of the fixing member to the rotation detection position. Therefore, in the second rotation detection position where the distance from the measurement rod fixing portion is shorter than the rotation detection position, the rod body and the measurement rod occur when an excessive load is applied to the excavation rod and the twist of the rod body is large. Large relative rotation can be detected. On the other hand, at the rotation detection position where the distance from the measurement rod fixing portion is longer than the second rotation detection position, the load applied to the excavation rod is small and the twist of the rod body is small (relative rotation between the rod body and the measurement rod is small). Even if it is small), the amount of rotation can be detected.

本発明において、前記変形検出器として、前記内壁面において前記軸線を間に挟んだ一方側および他方側にそれぞれ配置された２つの前記変形検出器を備えることが望ましい。このようにすれば、２つの変形検出器のそれぞれによって検出される移動量の差分に基づいて、ロッド本体がいずれの方向に撓んでいるかを取得できる。また、２つの変形検出器のそれぞれによって検出される移動量の差分に基づいて、ロッド本体の曲りの程度を把握できる。 In the present invention, it is desirable that the deformation detector includes two deformation detectors arranged on one side and the other side of the inner wall surface with the axis line sandwiched between them. In this way, it is possible to acquire in which direction the rod body is bent based on the difference in the amount of movement detected by each of the two deformation detectors. Further, the degree of bending of the rod body can be grasped based on the difference in the amount of movement detected by each of the two deformation detectors.

本発明において、前記変形検出器として、前記内壁面において前記軸線回りの等角度間隔に配置された４つの前記変形検出器を備えることが望ましい。このようにすれば、４つの変形検出器のそれぞれによって検出される移動量に基づいて、ロッド本体の軸線方向の伸縮を検出できる。また、４つの変形検出器のそれぞれによって検出される回転量に基づいて、ロッド本体の捩じれを精度よく検出できる。 In the present invention, it is desirable that the deformation detector includes four deformation detectors arranged at equal intervals around the axis on the inner wall surface. By doing so, it is possible to detect the expansion and contraction of the rod body in the axial direction based on the amount of movement detected by each of the four deformation detectors. Further, the twist of the rod body can be accurately detected based on the amount of rotation detected by each of the four deformation detectors.

本発明によれば、掘削ロッドのロッド本体が撓んで捩じれる変形量を、変形検出器が検出する移動量および回転量に基づいて取得できる。ここで、掘削ロッドのロッド本体の変形量を取得できれば、掘削ロッドにかかっている負荷（トルク）を取得できる。従って、掘削時に掘削ロッドにかかる負荷により掘削先端地盤の抵抗の大小が検出でき、ロッド本体が破損することを回避できる。
また、掘削ヘッド直上でロッドにかかる負荷と、掘削電流値及び積算電流値を比較検討することにより、地盤抵抗の変化がより正確に判断でき、支持地盤の出現深度を容易に確認できる。 According to the present invention, the amount of deformation in which the rod body of the excavation rod is bent and twisted can be obtained based on the amount of movement and the amount of rotation detected by the deformation detector. Here, if the amount of deformation of the rod body of the excavation rod can be acquired, the load (torque) applied to the excavation rod can be acquired. Therefore, it is possible to detect the magnitude of the resistance of the excavation tip ground due to the load applied to the excavation rod during excavation, and it is possible to avoid damaging the rod body.
Further, by comparing and examining the load applied to the rod directly above the excavation head and the excavation current value and the integrated current value, the change in the ground resistance can be determined more accurately, and the appearance depth of the supporting ground can be easily confirmed.

本発明を適用した掘削ロッドの使用状態を説明する概略図である。It is a schematic diagram explaining the use state of the excavation rod to which this invention is applied. 本発明の掘削ロッドに使用する変形検出器を説明する斜視図である。It is a perspective view explaining the deformation detector used for the excavation rod of this invention. 変形検出器が備える第１移動量検出器の説明図で、（ａ）は概略した断面図、（ｂ）は計測した信号の説明図である。It is explanatory drawing of the 1st movement amount detector included in the deformation detector, (a) is the schematic sectional view, (b) is the explanatory view of the measured signal. 変形検出器が備える第１回転量検出器の説明図で、（ａ）は概略した断面図、（ｂ）は計測した信号の説明図である。It is explanatory drawing of the 1st rotation amount detector included in the deformation detector, (a) is the schematic sectional view, (b) is the explanatory view of the measured signal. 変形検出器の信号伝送機構の説明図である。It is explanatory drawing of the signal transmission mechanism of a deformation detector. 他の実施形態の掘削ロッドの拡大断面図である。It is an enlarged sectional view of the excavation rod of another embodiment. 他の実施形態の掘削ロッドの拡大断面図である。It is an enlarged sectional view of the excavation rod of another embodiment.

以下に、図面を参照して、本発明を適用した掘削ロッドを説明する。 The excavation rod to which the present invention is applied will be described below with reference to the drawings.

１．掘削ロッド１の構成 1. 1. Configuration of excavation rod 1

図１は掘削ロッド１の説明図である。掘削ロッド１は、既製杭などを埋設する杭穴２を掘削する際に、杭打ち機３に取り付けられて用いられる。杭打ち機３は地上を鉛直方向に延びるマスト４と、マスト４に昇降自在に取り付けられたオーガー５を備える。掘削ロッド１はオーガー５に取り付けられている。 FIG. 1 is an explanatory diagram of the excavation rod 1. The excavation rod 1 is used by being attached to a pile driver 3 when excavating a pile hole 2 for burying a ready-made pile or the like. The pile driver 3 includes a mast 4 extending vertically on the ground and an auger 5 attached to the mast 4 so as to be vertically movable. The excavation rod 1 is attached to the auger 5.

掘削ロッド１は、掘削ヘッド１１と、端部に掘削ヘッド１１が取り付けられるロッド本体１２と、を有する。ロッド本体１２の軸線Ｌ方向において、掘削ヘッド１１が取り付けられている一方側とは反対の他方側の端部はオーガー５に接続されている。オーガー５に接続されたときに、掘削ヘッド１１は掘削ロッド１が下端に位置する掘削姿勢１Ａとされる。オーガー５が駆動されると、ロッド本体１２は軸線Ｌ回りに回転し、掘削ヘッド１１が地面７を掘削する。 The excavation rod 1 has an excavation head 11 and a rod body 12 to which the excavation head 11 is attached to an end portion. In the L direction of the axis of the rod body 12, the end of the other side opposite to the one on which the excavation head 11 is attached is connected to the auger 5. When connected to the auger 5, the excavation head 11 has an excavation posture 1A in which the excavation rod 1 is located at the lower end. When the auger 5 is driven, the rod body 12 rotates around the axis L, and the excavation head 11 excavates the ground 7.

ロッド本体１２は、円筒状である。ロッド本体１２の内壁面１２ａには当該ロッド本体１２の変形を検出する変形検出器１５が取り付けられている。図１で、変形検出器１５からみて、掘削ロッド１の下端側（すなわち掘削ヘッド１１側）をＹ１方向、掘削ロッド１の上端側（すなわちオーガー５側）をＹ２方向とする。
ここで、ロッド本体１２は、その中空部分に、掘削した杭穴２にセメントミルクを流し込むための小径円筒状の流通管１８を同軸に備える場合がある。この場合には、変形検出器１５は、ロッド本体１２の内壁面１２ａと流通管１８との間に構成される（図６）。 The rod body 12 has a cylindrical shape. A deformation detector 15 for detecting the deformation of the rod body 12 is attached to the inner wall surface 12a of the rod body 12. In FIG. 1, when viewed from the deformation detector 15, the lower end side of the excavation rod 1 (that is, the excavation head 11 side) is in the Y1 direction, and the upper end side of the excavation rod 1 (that is, the auger 5 side) is in the Y2 direction.
Here, the rod main body 12 may coaxially include a small-diameter cylindrical flow pipe 18 for pouring cement milk into the excavated pile hole 2 in the hollow portion thereof. In this case, the deformation detector 15 is configured between the inner wall surface 12a of the rod body 12 and the flow pipe 18 (FIG. 6).

２．変形検出器１５の構成 2. 2. Configuration of deformation detector 15

図２は変形検出器１５の説明図である。図２では、変形検出器１５の構成が分かるように、ロッド本体１２を、点線で示す。図３（ａ）は、第１移動量検出器３１の構成の説明図であり、図３（ｂ）は第１移動量検出器３１から出力される信号の説明図である。図３(ａ)では、第１移動量検出器３１を計測ロッド２１の計測ロッド軸線Ｌ１と直交する方向から見ている。図４（ａ）は第１回転量検出器３２の構成の説明図であり、図４（ｂ）は第１回転量検出器３２から出力される信号の説明図である。図４(ａ)では、第１回転量検出器３２を計測ロッド２１の計測ロッド軸線Ｌ１方向から見ている。図５は変形検出器１５からの信号を地上に送信する伝送機構の説明図である。 FIG. 2 is an explanatory diagram of the deformation detector 15. In FIG. 2, the rod body 12 is shown by a dotted line so that the configuration of the deformation detector 15 can be understood. FIG. 3A is an explanatory diagram of the configuration of the first movement amount detector 31, and FIG. 3B is an explanatory diagram of a signal output from the first movement amount detector 31. In FIG. 3A, the first movement amount detector 31 is viewed from a direction orthogonal to the measurement rod axis L1 of the measurement rod 21. FIG. 4A is an explanatory diagram of the configuration of the first rotation amount detector 32, and FIG. 4B is an explanatory diagram of a signal output from the first rotation amount detector 32. In FIG. 4A, the first rotation amount detector 32 is viewed from the measurement rod axis L1 direction of the measurement rod 21. FIG. 5 is an explanatory diagram of a transmission mechanism that transmits a signal from the deformation detector 15 to the ground.

図２に示すように、変形検出器１５は、ロッド本体１２の内壁面１２ａから内周側に離間する位置を軸線Ｌ方向に延びる計測ロッド２１と、計測ロッド２１の軸線Ｌ１方向（すなわち、軸線Ｌ方向）に離間する位置で計測ロッド２１を支持する固定部材２２および複数の支持部材２３、２３を備える。計測ロッド２１はロッド本体１２よりも十分に細い。また、変形検出器１５は軸線Ｌ１方向に延びる長尺状のベース部材２４を有する。ベース部材２４は、ロッド本体１２の内壁面１２ａにおいて、軸線Ｌ１方向（＝軸線Ｌ方向）と直交する径方向で計測ロッド２１と重なる位置に固定されている。ベース部材２４の外側面２４ａ（軸線Ｌ１とは反対側に位置する面）はロッド本体１２の内壁面１２ａの形状に対応する円弧形状を備える曲面である。ベース部材２４の外側面２４ａは、ロッド本体１２の内壁面１２ａに密着する状態で固定されている。ベース部材２４の内側面２４ｂ（軸線Ｌ１の側の面）は径方向と直交する平面である。固定部材２２および複数の支持部材２３は、ベース部材２４を介して、内壁面１２ａに固定されている。なお、変形検出器１５の計測ロッド２１は、ロッド本体１２の内側面１２ａの変形を計測するので、できるだけロッド本体１２の内側面１２ａに近い位置に配置することが望ましい。 As shown in FIG. 2, the deformation detector 15 has a measuring rod 21 extending in the axis L direction at a position separated from the inner wall surface 12a of the rod body 12 toward the inner peripheral side, and the axis L1 direction (that is, the axis) of the measuring rod 21. A fixing member 22 for supporting the measurement rod 21 and a plurality of support members 23, 23 are provided at positions separated from each other in the L direction. The measuring rod 21 is sufficiently thinner than the rod body 12. Further, the deformation detector 15 has a long base member 24 extending in the axis L1 direction. The base member 24 is fixed at a position on the inner wall surface 12a of the rod main body 12 so as to overlap the measuring rod 21 in the radial direction orthogonal to the axis L1 direction (= axis L direction). The outer surface 24a (the surface located on the side opposite to the axis L1) of the base member 24 is a curved surface having an arc shape corresponding to the shape of the inner wall surface 12a of the rod body 12. The outer surface 24a of the base member 24 is fixed in close contact with the inner wall surface 12a of the rod body 12. The inner side surface 24b (the surface on the side of the axis L1) of the base member 24 is a plane orthogonal to the radial direction. The fixing member 22 and the plurality of support members 23 are fixed to the inner wall surface 12a via the base member 24. Since the measuring rod 21 of the deformation detector 15 measures the deformation of the inner side surface 12a of the rod body 12, it is desirable to arrange it at a position as close as possible to the inner side surface 12a of the rod body 12.

ここで、図１に示すように、掘削ロッド１を掘削姿勢１Ａとしたとき（すなわち、略鉛直方向に配置してＹ１方向、Ｙ２方向が略鉛直方向となったとき）に、固定部材２２は、ロッド本体１２の下端部分（すなわち、Ｙ２方向の端）に位置する（図２）。すなわち、固定部材２２は、掘削ヘッド１１に近い位置に配置されている。複数の支持部材２３、２３は固定部材２２から上方に離間する位置にある。複数の支持部材２３、２３は軸線Ｌ１方向で互いに離間している。 Here, as shown in FIG. 1, when the excavation rod 1 is set to the excavation posture 1A (that is, when the excavation rod 1 is arranged in the substantially vertical direction and the Y1 direction and the Y2 direction are in the substantially vertical direction), the fixing member 22 is , Located at the lower end of the rod body 12 (that is, the end in the Y2 direction) (FIG. 2). That is, the fixing member 22 is arranged at a position close to the excavation head 11. The plurality of support members 23, 23 are located at positions separated upward from the fixing member 22. The plurality of support members 23, 23 are separated from each other in the axis L1 direction.

固定部材２２は、ベース部材２４に固定された固定部材側固定部２５と、固定部材側固定部２５よりも内周側（ロッド本体１２の軸線Ｌ側）で計測ロッド２１が固定された計測ロッド固定部２６とを備える。固定部材２２は、ベース部材２４を介して、内壁面１２ａに固定されている。また、計測ロッド２１は、計測ロッド軸線Ｌ１方向の先端部（掘削姿勢１Ａとしたときの下端部）が、固定部材２２およびベース部材２４を介して、ロッド本体１２の内壁面１２ａに固定されている。 The fixing member 22 is a measuring rod in which the fixing member side fixing portion 25 fixed to the base member 24 and the measuring rod 21 are fixed on the inner peripheral side (axis line L side of the rod body 12) of the fixing member side fixing portion 25. A fixing portion 26 is provided. The fixing member 22 is fixed to the inner wall surface 12a via the base member 24. Further, in the measuring rod 21, the tip end portion (the lower end portion when the excavation posture is 1A) in the measurement rod axis L1 direction is fixed to the inner wall surface 12a of the rod body 12 via the fixing member 22 and the base member 24. There is.

各支持部材２３、２３は、ベース部材２４に固定された支持部材側固定部２８と、支持部材側固定部２８よりも内周側（ロッド本体１２の軸線Ｌ側）で計測ロッド２１を当該計測ロッド２１の計測ロッド軸線Ｌ１方向に移動可能、かつ、計測ロッド軸線Ｌ１回りに回転可能に支持する計測ロッド支持部２９と、を備える。支持部材側固定部２８は、ベース部材２４を介して、ロッド本体１２の内壁面１２ａに固定されている。計測ロッド支持部２９は、軸線Ｌ１方向に貫通する貫通穴２９ａを備える。貫通穴２９ａの直径は計測ロッド２１の直径よりも大きく設定されており、これにより、支持部材２３は、計測ロッド支持部２９によって計測ロッド２１を移動可能かつ回転可能に支持する。 Each of the support members 23, 23 measures the measurement rod 21 on the inner peripheral side (axis line L side of the rod body 12) of the support member side fixing portion 28 fixed to the base member 24 and the support member side fixing portion 28. A measuring rod support portion 29 that can move in the direction of the measuring rod axis L1 of the rod 21 and rotatably supports around the measuring rod axis L1 is provided. The support member side fixing portion 28 is fixed to the inner wall surface 12a of the rod main body 12 via the base member 24. The measuring rod support portion 29 includes a through hole 29a penetrating in the axis L1 direction. The diameter of the through hole 29a is set to be larger than the diameter of the measuring rod 21, whereby the support member 23 movably and rotatably supports the measuring rod 21 by the measuring rod supporting portion 29.

固定部材２２における固定部材側固定部２５から計測ロッド固定部２６までの寸法Ｈ１と、支持部材２３における支持部材側固定部２８から計測ロッド支持部２９までの寸法Ｈ２とは同一である。これにより、計測ロッド２１はベース部材２２の内側面２４ｂから距離Ｈ１（＝Ｈ２）で略平行に配置されるので（図２）、固定部材２２および複数の支持部材２３は計測ロッド２１を全長に亘り、内壁面１２ａから一定距離だけ離間する位置に支持する。 The dimension H1 from the fixing member side fixing portion 25 to the measuring rod fixing portion 26 in the fixing member 22 and the dimension H2 from the supporting member side fixing portion 28 to the measuring rod supporting portion 29 in the supporting member 23 are the same. As a result, the measuring rod 21 is arranged substantially parallel to the inner side surface 24b of the base member 22 at a distance H1 (= H2) (FIG. 2). It is supported at a position separated from the inner wall surface 12a by a certain distance.

また、変形検出器１５は、計測ロッド固定部２６から軸線Ｌ１方向に離間する移動検出位置Ａで、ロッド本体１２の内壁面１２ａと計測ロッド２１とが計測ロッド軸線Ｌ１方向で相対移動する移動量を検出する第１移動量検出器３１を備える。さらに、変形検出器１５は、計測ロッド固定部２６から軸線Ｌ１方向に離間する第１回転検出位置Ｂで、ロッド本体１２の内壁面１２ａと計測ロッド２１とが計測ロッド軸線Ｌ１回りで相対回転する回転量を検出する第１回転量検出器３２を備える。また、変形検出器１５は、計測ロッド固定部２６と移動検出位置Ａとの間の第２移動検出位置Ｃで、ロッド本体１２の内壁面１２ａと計測ロッド２１とが計測ロッド軸線Ｌ１方向で相対移動する第２移動量を検出する第２移動量検出器３３を備える。さらに変形検出器１５は、計測ロッド固定部２６と回転検出位置Ｂとの間の第２回転検出位置Ｄで、ロッド本体１２の内壁面１２ａと計測ロッド２１とが計測ロッド軸線Ｌ１回りで相対回転する第２回転量を検出する第２回転量検出器３４とを備える。 Further, the deformation detector 15 is a movement detection position A separated from the measurement rod fixing portion 26 in the axis L1 direction, and the movement amount in which the inner wall surface 12a of the rod body 12 and the measurement rod 21 move relative to each other in the measurement rod axis L1 direction. A first movement amount detector 31 for detecting the above is provided. Further, in the deformation detector 15, at the first rotation detection position B separated from the measurement rod fixing portion 26 in the axis L1 direction, the inner wall surface 12a of the rod body 12 and the measurement rod 21 rotate relative to each other around the measurement rod axis L1. A first rotation amount detector 32 for detecting the rotation amount is provided. Further, in the deformation detector 15, at the second movement detection position C between the measurement rod fixing portion 26 and the movement detection position A, the inner wall surface 12a of the rod body 12 and the measurement rod 21 are relative to each other in the measurement rod axis L1 direction. A second movement amount detector 33 for detecting the second movement amount to be moved is provided. Further, in the deformation detector 15, at the second rotation detection position D between the measurement rod fixing portion 26 and the rotation detection position B, the inner wall surface 12a of the rod body 12 and the measurement rod 21 rotate relative to each other around the measurement rod axis L1. A second rotation amount detector 34 for detecting the second rotation amount to be performed is provided.

ここで、第１移動量検出器３１と第２移動量検出器３３とは、軸線Ｌ１方向における設置位置は相違するが、それらの構成は同一である。また、第１回転量検出器３２と第２回転量検出器３４とは、軸線Ｌ１方向における設置位置は相違するが、それらの構成は同一である。従って、以下では、第１移動量検出器３１を説明して、第２移動量検出器３３の説明を省略する。また、第１回転量検出器３２を説明して、第２回転量検出器３４の説明は省略する。 Here, the first movement amount detector 31 and the second movement amount detector 33 are different in the installation position in the axis L1 direction, but their configurations are the same. Further, the first rotation amount detector 32 and the second rotation amount detector 34 are different in the installation position in the axis L1 direction, but their configurations are the same. Therefore, in the following, the first movement amount detector 31 will be described, and the description of the second movement amount detector 33 will be omitted. Further, the first rotation amount detector 32 will be described, and the description of the second rotation amount detector 34 will be omitted.

図３（ａ）に示すように、第１移動量検出器３１は、計測ロッド２１に固定された移動量検出用磁石４１と、ベース部材２４の内側面２４ｂに固定された移動量検出用磁気センサ４２と、を備える。移動量検出用磁石４１と移動量検出用磁気センサ４２とは計測ロッド軸線Ｌ１と直交する計測ロッド２１の径方向でギャップ３７を開けて対向する。移動量検出用磁石４１は環状であり、その中心孔４１を計測ロッド２１が貫通した状態で計測ロッド２１に固定されている。移動量検出用磁石４１は計測ロッド軸線Ｌ１方向で、着磁分極線４１ａからＳ極とＮ極との２極に分割着磁されている。移動量検出用磁気センサ４２は、当該移動量検出用磁気センサ４２のセンサ面４２ａと移動量検出用磁石４１の着磁分極線４１ａとが計測ロッド軸線Ｌ１方向で相対移動すると、その移動量に対応する信号Ｓ１を出力する。 As shown in FIG. 3A, the first movement amount detector 31 has a movement amount detection magnet 41 fixed to the measuring rod 21 and a movement amount detection magnet fixed to the inner side surface 24b of the base member 24. A sensor 42 is provided. The movement amount detection magnet 41 and the movement amount detection magnetic sensor 42 face each other with a gap 37 opened in the radial direction of the measurement rod 21 orthogonal to the measurement rod axis L1. The movement amount detection magnet 41 has an annular shape, and is fixed to the measuring rod 21 with the measuring rod 21 penetrating the central hole 41 thereof. The moving amount detection magnet 41 is divided and magnetized from the magnetizing polarization line 41a into two poles, an S pole and an N pole, in the direction of the measurement rod axis L1. When the sensor surface 42a of the movement amount detection magnetic sensor 42 and the magnetizing polarization line 41a of the movement amount detection magnet 41 move relative to each other in the measurement rod axis L1 direction, the movement amount detection magnetic sensor 42 changes the movement amount. The corresponding signal S1 is output.

例えば、図３（ａ）に示すように、移動量検出用磁石４１の着磁分極線４１ａが、移動量検出用磁気センサ４２のセンサ面４２ａと正対する位置では、移動量検出用磁気センサ４２からの信号Ｓ１はゼロとなる。計測ロッド２１が計測ロッド軸線Ｌ１方向の一方側Ｑ１に移動して着磁分極線４１ａが計測ロッド軸線Ｌ１の一方側Ｑ１に移動すると（図２）、図３（ｂ）に示すように、その移動量に応じて、移動量検出用磁気センサ４２からの信号Ｓ１はプラス側に増大する。その後、着磁分極線４１ａのセンサ面４２ａからの離間が所定の距離を超えると、移動量検出用磁気センサ４２からの信号Ｓ１は減少に転じる。
一方、計測ロッド２１が計測ロッド軸線Ｌ１方向の他方側Ｑ２に移動して着磁分極線４１ａが計測ロッド軸線Ｌ１の他方側Ｑ２に移動すると（図２）、その移動量に応じて、移動量検出用磁気センサ４２からの信号Ｓ１はマイナス側に増大する。その後、着磁分極線４１ａのセンサ面４２ａからの離間が所定の距離を超えると、移動量検出用磁気センサ４２からの信号Ｓ１は減少に転じる。
ここで、計測ロッド２１の移動量を検出する第１移動量検出器３１の検出範囲は、移動量検出用磁石４１の着磁分極線４１ａがセンサ面４２ａと正対する位置にある計測ロッド２１が、計測ロッド軸線Ｌ１方向の一方側Ｑ１および他方側Ｑ２に所定の距離だけ移動する範囲である。なお、ここでは、Ｑ１方向はＹ１方向と同じであり、計測ロッド２１が相対的に原長さを保った状態（移動量検出磁石４１が定位置を保った状態）で、ロッド本体１２が移動量磁気センサ４２と共に伸びた状態である。また、Ｑ２方向はＹ２方向と同じであり、同様にロッド本体１２が移動量磁気センサ４２と共に縮んだ状態である（図２）。 For example, as shown in FIG. 3A, at a position where the magnetizing polarization line 41a of the movement amount detection magnet 41 faces the sensor surface 42a of the movement amount detection magnetic sensor 42, the movement amount detection magnetic sensor 42 The signal S1 from is zero. When the measuring rod 21 moves to one side Q1 in the measurement rod axis L1 direction and the magnetizing polarization line 41a moves to one side Q1 of the measuring rod axis L1 (FIG. 2), as shown in FIG. 3 (b), the magnetizing rod 21 moves to one side Q1. The signal S1 from the magnetic sensor 42 for detecting the movement amount increases to the plus side according to the movement amount. After that, when the distance of the magnetizing polarization line 41a from the sensor surface 42a exceeds a predetermined distance, the signal S1 from the magnetic sensor 42 for detecting the amount of movement starts to decrease.
On the other hand, when the measurement rod 21 moves to the other side Q2 in the measurement rod axis L1 direction and the magnetizing polarization line 41a moves to the other side Q2 of the measurement rod axis L1 (FIG. 2), the movement amount corresponds to the movement amount. The signal S1 from the detection magnetic sensor 42 increases to the minus side. After that, when the distance of the magnetizing polarization line 41a from the sensor surface 42a exceeds a predetermined distance, the signal S1 from the magnetic sensor 42 for detecting the amount of movement starts to decrease.
Here, the detection range of the first movement amount detector 31 that detects the movement amount of the measurement rod 21 is that the measurement rod 21 at a position where the magnetizing polarization line 41a of the movement amount detection magnet 41 faces the sensor surface 42a. , Is a range in which the measurement rod moves to one side Q1 and the other side Q2 in the L1 direction by a predetermined distance. Here, the Q1 direction is the same as the Y1 direction, and the rod body 12 moves in a state where the measurement rod 21 keeps its original length relatively (a state in which the movement amount detection magnet 41 keeps a fixed position). It is in a stretched state together with the quantitative magnetic sensor 42. Further, the Q2 direction is the same as the Y2 direction, and the rod body 12 is similarly contracted together with the movement amount magnetic sensor 42 (FIG. 2).

図４（ａ）に示すように、第１回転量検出器３２は、ホルダ４５を介して計測ロッド２１固定された回転量検出用磁石４６と、ベース部材２４の内側面２４ｂに固定された回転量検出用磁気センサ４７と、を備える。回転量検出用磁石４６は、計測ロッド軸線Ｌ１回りの周方向で、着磁分極線４６ａからＮ極とＳ極との２極に分割着磁されている。回転量検出用磁気センサ４７は、当該回転量検出用磁気センサ４７のセンサ面４７ａと回転量検出用磁石４６の着磁分極線４６ａとが周方向で相対回転すると、その回転量に対応する信号Ｓ２を出力する。 As shown in FIG. 4A, the first rotation amount detector 32 includes a rotation amount detection magnet 46 fixed to the measuring rod 21 via a holder 45, and rotation fixed to the inner side surface 24b of the base member 24. A magnetic sensor 47 for quantity detection is provided. The rotation amount detection magnet 46 is divided and magnetized from the magnetizing polarization line 46a into two poles, an N pole and an S pole, in the circumferential direction around the measurement rod axis L1. The rotation amount detection magnetic sensor 47 is a signal corresponding to the rotation amount when the sensor surface 47a of the rotation amount detection magnetic sensor 47 and the magnetizing polarization line 46a of the rotation amount detection magnet 46 rotate relative to each other in the circumferential direction. Output S2.

例えば、図４（ａ）に示すように、回転量検出用磁石４６の着磁分極線４６ａがセンサ面４７ａと正対する位置では、回転量検出用磁気センサ４７からの信号Ｓ２はゼロとなる。計測ロッド２１が、計測ロッド軸線Ｌ１回りの一方側Ｒ１に回転して（図２）、着磁分極線４６ａが計測ロッド軸線Ｌ１回りの一方側Ｒ１に回転すると、図４（ｂ）に示すように、その回転量に応じて、回転量検出用磁気センサ４７からの信号Ｓ２はプラス側に増大する。その後、着磁分極線４６ａのロッド軸線Ｌ１回りの角度位置が所定の角度位置を超えると、回転量検出用磁気センサ４７からの信号Ｓ２は減少に転じる。
一方、計測ロッド２１が計測ロッド軸線Ｌ１回りの他方側Ｒ２に回転して（図２）、着磁分極線４６ａが計測ロッド軸線Ｌ１回りの他方側Ｒ２に回転すると、その回転量に応じて、回転量検出用磁気センサ４７からの信号Ｓ２はマイナス側に増大する。その後、着磁分極線４６ａのロッド軸線Ｌ１回りの角度位置が所定の角度位置を超えると、回転量検出用磁気センサ４７からの信号Ｓ２は減少に転じる。
ここで、計測ロッド２１の回転量を検出する第１回転量検出器３２の検出範囲は、回転量検出用磁石４６の着磁分極線４６ａがセンサ面４７ａと正対する位置にある計測ロッド２１が、計測ロッド軸線Ｌ１回りの一方側Ｒ１および他方側Ｒ２で所定の角度位置まで回転する範囲である。 For example, as shown in FIG. 4A, the signal S2 from the rotation amount detection magnetic sensor 47 becomes zero at the position where the magnetizing polarization line 46a of the rotation amount detection magnet 46 faces the sensor surface 47a. When the measuring rod 21 rotates to one side R1 around the measuring rod axis L1 (FIG. 2) and the magnetizing polarization line 46a rotates to one side R1 around the measuring rod axis L1, as shown in FIG. 4 (b). In addition, the signal S2 from the rotation amount detection magnetic sensor 47 increases to the plus side according to the rotation amount. After that, when the angular position around the rod axis L1 of the magnetizing polarization line 46a exceeds a predetermined angular position, the signal S2 from the rotation amount detection magnetic sensor 47 starts to decrease.
On the other hand, when the measuring rod 21 rotates to the other side R2 around the measuring rod axis L1 (FIG. 2) and the magnetizing polarization line 46a rotates to the other side R2 around the measuring rod axis L1, depending on the amount of rotation, The signal S2 from the rotation amount detection magnetic sensor 47 increases to the minus side. After that, when the angular position around the rod axis L1 of the magnetizing polarization line 46a exceeds a predetermined angular position, the signal S2 from the rotation amount detection magnetic sensor 47 starts to decrease.
Here, the detection range of the first rotation amount detector 32 that detects the rotation amount of the measurement rod 21 is that the measurement rod 21 at a position where the magnetizing polarization line 46a of the rotation amount detection magnet 46 faces the sensor surface 47a. , It is a range of rotation to a predetermined angle position on one side R1 and the other side R2 around the measurement rod axis L1.

次に、変形検出器１５は、図２および図５に示すように、第１移動量検出器３１からの信号Ｓ１、第１回転量検出器３２からの信号Ｓ２、第２移動量検出器３３からの信号Ｓ１´、第２回転量検出器３４からの信号Ｓ２´、を地上の上位機器に送信するための信号伝送機構５１を備える。図５に示すように、信号伝送機構５１は、デジタル通信線５２と、第１移動量検出器３１からの信号Ｓ１および第１回転量検出器３２からの信号Ｓ２を、デジタル通信線５２を介して送信する第１通信部５３と、第２移動量検出器３３からの信号Ｓ１´および第２回転量検出器３４からの信号Ｓ２´を、デジタル通信線５２を介して送信する第２通信部５４とを備える。第１通信部５３および第２通信部５４のそれぞれは、Ａ/Ｄ変換器５５とデジタル通信制御部５６を備える（図５）。 Next, as shown in FIGS. 2 and 5, the deformation detector 15 has a signal S1 from the first movement amount detector 31, a signal S2 from the first rotation amount detector 32, and a second movement amount detector 33. The signal transmission mechanism 51 for transmitting the signal S1'from the above and the signal S2' from the second rotation amount detector 34 to a higher-level device on the ground is provided. As shown in FIG. 5, the signal transmission mechanism 51 transmits the digital communication line 52, the signal S1 from the first movement amount detector 31 and the signal S2 from the first rotation amount detector 32 via the digital communication line 52. The second communication unit 53 that transmits the signal S1'from the second movement amount detector 33 and the signal S2'from the second rotation amount detector 34 via the digital communication line 52. It is equipped with 54. Each of the first communication unit 53 and the second communication unit 54 includes an A / D converter 55 and a digital communication control unit 56 (FIG. 5).

第１移動量検出器３１からの信号Ｓ１、第１回転量検出器３２からの信号Ｓ２は、第１通信部５３において、Ａ/Ｄ変換器５５に入力されて、アナログ信号Ｓ１からデジタル信号に変換される。Ａ/Ｄ変換器５５から出力されるデジタル信号はデジタル通信制御部５６に入力され、デジタル通信制御部５６から、デジタル通信線５２を介して地上の上位機器に送信される。第２移動量検出器３３からの信号Ｓ１´、第２回転量検出器３４からの信号Ｓ２´は、第２通信部５４において、Ａ/Ｄ変換器５５に入力されて、アナログ信号Ｓ１からデジタル信号に変換される。Ａ/Ｄ変換器５５から出力されるデジタル信号はデジタル通信制御部５６に入力され、デジタル通信制御部５６から、デジタル通信線５２を介して地上の上位機器に送信される（図５）。 The signal S1 from the first movement amount detector 31 and the signal S2 from the first rotation amount detector 32 are input to the A / D converter 55 in the first communication unit 53, and are converted from the analog signal S1 to the digital signal. Will be converted. The digital signal output from the A / D converter 55 is input to the digital communication control unit 56, and is transmitted from the digital communication control unit 56 to a higher-level device on the ground via the digital communication line 52. The signal S1'from the second movement amount detector 33 and the signal S2'from the second rotation amount detector 34 are input to the A / D converter 55 in the second communication unit 54, and are digitally transmitted from the analog signal S1. Converted to a signal. The digital signal output from the A / D converter 55 is input to the digital communication control unit 56, and is transmitted from the digital communication control unit 56 to a higher-level device on the ground via the digital communication line 52 (FIG. 5).

第１通信部５３のデジタル通信制御部５６は、第１移動量検出器３１（移動量検出用磁気センサ４２）からの信号Ｓ１に基づくデジタル信号、および、第１回転量検出器３２（回転量検出用磁気センサ４７からの信号Ｓ２）に基づくデジタル信号のそれぞれに識別情報を付与して、上位機器に送信する。同様に、第２通信部５４のデジタル通信制御部５６は、第２移動量検出器３３（移動量検出用磁気センサ４２）からの信号Ｓ１´に基づくデジタル信号、および、第１回転量検出器３４（回転量検出用磁気センサ４７からの信号Ｓ２´）に基づくデジタル信号のそれぞれに識別情報を付与して、上位機器に送信する。 The digital communication control unit 56 of the first communication unit 53 includes a digital signal based on the signal S1 from the first movement amount detector 31 (movement amount detection magnetic sensor 42) and the first rotation amount detector 32 (rotation amount). Identification information is added to each of the digital signals based on the signal S2) from the detection magnetic sensor 47, and the signal is transmitted to a higher-level device. Similarly, the digital communication control unit 56 of the second communication unit 54 is a digital signal based on the signal S1'from the second movement amount detector 33 (movement amount detection magnetic sensor 42), and the first rotation amount detector. Identification information is added to each of the digital signals based on 34 (signal S2'from the rotation amount detection magnetic sensor 47) and transmitted to a higher-level device.

本例では、第１通信部５３のデジタル通信制御部５６は、第１移動量検出器３１からの信号Ｓ１に基づくデジタル信号にＣＨ１という識別情報を付加し、第１回転量検出器３２からの信号Ｓ２に基づくデジタル信号にＣＨ２という識別情報を付加する。また、第２通信部５４のデジタル通信制御部５６は、第２移動量検出器３３からの信号Ｓ１´に基づくデジタル信号にＣＨ３という識別情報を付加し、第２回転量検出器３４からの信号Ｓ２´´に基づくデジタル信号にＣＨ４という識別情報を付加する。従って、デジタル通信線５２を介して信号を受信した上位機器では、受信した信号が第１移動量検出器３１、第１回転量検出器３２、第２移動量検出器３３、第２回転量検出器３４のいずれから出力された信号に基づくデジタル信号であるかを識別できる。 In this example, the digital communication control unit 56 of the first communication unit 53 adds the identification information CH1 to the digital signal based on the signal S1 from the first movement amount detector 31, and from the first rotation amount detector 32. The identification information CH2 is added to the digital signal based on the signal S2. Further, the digital communication control unit 56 of the second communication unit 54 adds the identification information CH3 to the digital signal based on the signal S1'from the second movement amount detector 33, and the signal from the second rotation amount detector 34. The identification information CH4 is added to the digital signal based on S2 ″. Therefore, in the host device that received the signal via the digital communication line 52, the received signal is the first movement amount detector 31, the first rotation amount detector 32, the second movement amount detector 33, and the second rotation amount detection. It is possible to identify which of the devices 34 is the digital signal based on the output signal.

なお、デジタル通信線５２はロッド本体１１内を配線して、地面７上の上位機器に接続される。一般に、掘削ロッド１は、所定長さのロッド本体１２の複数本をつないで、地盤の深い位置まで掘削する。したがって、ロッド本体１２を上下に連結する際に、簡易に接続できるジョイント（カプラー）で上下のデジタル通信線５２、５２をつなぐことが望ましい。 The digital communication line 52 is wired inside the rod body 11 and connected to a higher-level device on the ground 7. Generally, the excavation rod 1 connects a plurality of rod main bodies 12 having a predetermined length to excavate to a deep position in the ground. Therefore, when connecting the rod body 12 vertically, it is desirable to connect the upper and lower digital communication lines 52 and 52 with a joint (coupler) that can be easily connected.

３．変形検出器１５の動作原理 3. 3. Operating principle of the deformation detector 15

次に、変形検出器１５の動作原理を説明する。図２に示すように、変形検出器１５は、ロッド本体１２の内周壁面１２ａの内側（軸線Ｌ側）を軸線Ｌ方向に延びる計測ロッド２１を備える。また、計測ロッド２１は、計測ロッド軸線Ｌ１方向の端部が、固定部材２２およびベース部材２４を介して、ロッド本体１２（内壁面１２ａ）に固定されている。 Next, the operating principle of the deformation detector 15 will be described. As shown in FIG. 2, the deformation detector 15 includes a measuring rod 21 that extends in the axis L direction inside the inner peripheral wall surface 12a of the rod body 12 (axis L side). Further, the end of the measuring rod 21 in the direction of the measuring rod axis L1 is fixed to the rod main body 12 (inner wall surface 12a) via the fixing member 22 and the base member 24.

ここで、ロッド本体１２は、一般に機械構造用炭素鋼鋼管鋼製（ＳＴＫＭ１３Ａ）であり、機械的な特性として若干の弾性を備えるものである。従って、掘削ロッド１にトルクが付与されてロッド本体１２が撓んだ場合には、計測ロッド２１とロッド本体１２との接続部となる固定部材２２の計測ロッド固定部２６から軸線Ｌ１方向（＝軸線Ｌ方向）に離間する移動検出位置Ａにおいて、計測ロッド２１とロッド本体１２（内周面）との軸線Ｌ１方向への相対移動が検出される。また、掘削ロッド１に過剰なトルクが付与されてロッド本体１２が捩じれた場合には、計測ロッド２１とロッド本体１２との接続部となる固定部材２２の計測ロッド固定部２６から軸線Ｌ１方向に離間する回転検出位置Ｂにおいて、計測ロッド２１とロッド本体１２（内周面）との軸線Ｌ１回りの相対回転を検出される。従って、変形検出器１５は、移動検出位置Ａにおいて計測ロッド２１とロッド本体１２（内周面１２ａ）とが相対移動した移動量と、回転検出位置Ｂにおいて計測ロッド２１とロッド本体１２（内周面１２ａ）とが相対回転した回転量と、を検出できる。また、上位機器では、変形検出器１５が検出した移動量と回転量とに基づいて、ロッド本体１２が撓んで捩じれる変形量を取得できる。 Here, the rod main body 12 is generally made of carbon steel pipe steel for mechanical structure (STKM13A), and has some elasticity as a mechanical characteristic. Therefore, when torque is applied to the excavation rod 1 and the rod body 12 bends, the axis L1 direction (=) from the measurement rod fixing portion 26 of the fixing member 22 which is the connecting portion between the measuring rod 21 and the rod body 12. At the movement detection position A separated from the axis L direction, the relative movement of the measuring rod 21 and the rod body 12 (inner peripheral surface) in the axis L1 direction is detected. Further, when an excessive torque is applied to the excavation rod 1 and the rod body 12 is twisted, the measuring rod fixing portion 26 of the fixing member 22 which is a connecting portion between the measuring rod 21 and the rod body 12 is directed toward the axis L1. At the separated rotation detection position B, the relative rotation of the measuring rod 21 and the rod body 12 (inner peripheral surface) around the axis L1 is detected. Therefore, the deformation detector 15 has a movement amount in which the measurement rod 21 and the rod body 12 (inner peripheral surface 12a) have moved relative to each other at the movement detection position A, and the measurement rod 21 and the rod body 12 (inner circumference) at the rotation detection position B. The amount of rotation relative to the surface 12a) can be detected. Further, in the host device, the amount of deformation in which the rod body 12 is bent and twisted can be acquired based on the amount of movement and the amount of rotation detected by the deformation detector 15.

また、変形検出器１５は、第１移動検出位置Ａで移動量を検出する第１移動量検出器３１と、軸線Ｌ方向で第１移動検出位置Ａと計測ロッド固定部２６との間に位置する第２移動検出位置Ｃで移動量を検出する第２移動量検出器３３とを備える。従って、計測ロッド２１とロッド本体１２と相対的な移動量を異なる２つの感度で検出できる。さらに、変形検出器１５は、第１回転検出位置Ｂで回転量を検出する第１回転量検出器３２と、軸線Ｌ方向で第１回転検出位置Ｂと計測ロッド固定部２６との間に位置する第２回転検出位置Ｄで回転量を検出する第２回転量検出器３４とを備える。従って、計測ロッド２１とロッド本体１２と相対的な回転量を異なる２つの感度で検出できる。 Further, the deformation detector 15 is located between the first movement amount detector 31 that detects the movement amount at the first movement detection position A, the first movement detection position A in the axis L direction, and the measurement rod fixing portion 26. A second movement amount detector 33 that detects the movement amount at the second movement detection position C is provided. Therefore, the amount of movement relative to the measuring rod 21 and the rod body 12 can be detected with two different sensitivities. Further, the deformation detector 15 is located between the first rotation amount detector 32 that detects the rotation amount at the first rotation detection position B, the first rotation detection position B in the axis L direction, and the measurement rod fixing portion 26. A second rotation amount detector 34 for detecting the rotation amount at the second rotation detection position D is provided. Therefore, the amount of rotation relative to the measuring rod 21 and the rod body 12 can be detected with two different sensitivities.

すなわち、ロッド本体１２が撓んだ場合の計測ロッド２１とロッド本体１２との相対的な移動量は、固定部材２２の計測ロッド固定部２６から移動検出位置までの軸線Ｌ方向の距離の長さに比例して大きくなる。従って、移動検出位置Ａよりも計測ロッド固定部２６からの距離が短い第２移動検出位置Ｃに配置した第２移動量検出器３３が移動量を検出する感度は、第１移動検出位置Ａに配置した第１移動量検出器３１が移動量を検出する検出感度よりも低い。これにより、第２移動検出位置Ｃに配置した第２移動量検出器３３では、掘削ロッド１に過大な負荷が加わってロッド本体１２が撓んだ場合に発生するロッド本体１２と計測ロッド２１との大きな相対移動を検出できる。一方、第２移動検出位置Ｃよりも計測ロッド固定部２６からの距離が長い移動検出位置Ａに配置した第１移動量検出器３１では、掘削ロッド１に加わる負荷が小さくてロッド本体１２の撓みが小さい場合（ロッド本体１２と計測ロッド２１との相対移動が小さい場合）でも、その移動量を検出できる。 That is, the relative movement amount between the measurement rod 21 and the rod body 12 when the rod body 12 is bent is the length of the distance in the axis L direction from the measurement rod fixing portion 26 of the fixing member 22 to the movement detection position. It increases in proportion to. Therefore, the sensitivity of the second movement amount detector 33 arranged at the second movement detection position C, which is shorter than the movement detection position A from the measurement rod fixing portion 26, to detect the movement amount is set to the first movement detection position A. The first movement amount detector 31 arranged is lower than the detection sensitivity for detecting the movement amount. As a result, in the second movement amount detector 33 arranged at the second movement detection position C, the rod body 12 and the measurement rod 21 generated when the rod body 12 is bent due to an excessive load applied to the excavation rod 1 Large relative movement of can be detected. On the other hand, in the first movement amount detector 31 arranged at the movement detection position A where the distance from the measurement rod fixing portion 26 is longer than the second movement detection position C, the load applied to the excavation rod 1 is small and the rod body 12 bends. Even when is small (when the relative movement between the rod body 12 and the measuring rod 21 is small), the movement amount can be detected.

同様に、ロッド本体１２が捩じれた場合の回転量は、固定部材２２の計測ロッド固定部２６から回転検出位置までの軸線Ｌ方向の距離の長さに比例して大きくなる。従って、第１回転検出位置Ｂよりも計測ロッド固定部２６からの距離が短い第２回転検出位置Ｄに配置した第２回転量検出器３４が回転量を検出する感度は、第１回転検出位置Ｂに配置した第１回転量検出器３２が回転量を検出する検出感度よりも低い。これにより、第２回転検出位置Ｄでは、掘削ロッド１に過大な負荷が加わってロッド本体１２が捩じれた場合に発生するロッド本体１２と計測ロッド２１との大きな相対回転を検出できる。一方、第２回転検出位置Ｄよりも計測ロッド固定部２６からの距離が長い第１回転検出位置Ｂでは、掘削ロッド１に加わる負荷が小さくてロッド本体１２の捩じれが小さい場合（ロッド本体１２と計測ロッド２１との相対回転が小さい場合）でも、その回転量を検出できる。 Similarly, the amount of rotation when the rod body 12 is twisted increases in proportion to the length of the distance in the axis L direction from the measurement rod fixing portion 26 of the fixing member 22 to the rotation detection position. Therefore, the sensitivity of the second rotation amount detector 34 arranged at the second rotation detection position D, which is shorter than the first rotation detection position B from the measurement rod fixing portion 26, to detect the rotation amount is the first rotation detection position. The first rotation amount detector 32 arranged in B is lower than the detection sensitivity for detecting the rotation amount. As a result, at the second rotation detection position D, it is possible to detect a large relative rotation between the rod body 12 and the measuring rod 21 that occurs when the rod body 12 is twisted due to an excessive load applied to the excavation rod 1. On the other hand, at the first rotation detection position B, where the distance from the measurement rod fixing portion 26 is longer than the second rotation detection position D, the load applied to the excavation rod 1 is small and the twist of the rod body 12 is small (with the rod body 12). Even when the relative rotation with the measuring rod 21 is small), the rotation amount can be detected.

４．掘削ロッド１の作動と作用効果 4. Operation and action effect of excavation rod 1

通常の杭穴掘削と同様に、掘削ロッド１を使用して、地面７から掘削ヘッド１１で杭穴２を掘削する（図１）。この際、掘削ロッド１の上端であるオーガー５の回転および下降が、掘削ロッド１の下端で掘削ヘッド１１に伝わり、掘削ヘッド１１は地盤の抵抗を受ける。したがって、地盤によっては（固い地盤や転石など）、掘削ロッド１は、上端と下端との間で、撓みや捻りや圧縮引張などの変形を受けることになる。 Similar to normal pile hole excavation, the pile hole 2 is excavated from the ground 7 with the excavation head 11 using the excavation rod 1 (FIG. 1). At this time, the rotation and descent of the auger 5, which is the upper end of the excavation rod 1, is transmitted to the excavation head 11 at the lower end of the excavation rod 1, and the excavation head 11 receives the resistance of the ground. Therefore, depending on the ground (hard ground, boulders, etc.), the excavation rod 1 is subject to deformation such as bending, twisting, and compressive tension between the upper end and the lower end.

本例では、ロッド本体１２に第１変形検出器１５および第２変形検出器１５を備えるので、第１移動検出位置Ａおよび第２検出位置のそれぞれにおいて計測ロッド２１とロッド本体１２（内周面）とが相対移動した移動量と、回転検出位置Ｂにおいて計測ロッド２１とロッド本体１２（内周面）とが相対回転した回転量とを検出できる。従って、これらの移動量および回転量に基づいて、ロッド本体１２が撓んで捩じれる変形量を取得できる。 In this example, since the rod body 12 is provided with the first deformation detector 15 and the second deformation detector 15, the measuring rod 21 and the rod body 12 (inner peripheral surface) are provided at the first movement detection position A and the second detection position, respectively. ) And the relative movement amount, and the rotation amount in which the measuring rod 21 and the rod body 12 (inner peripheral surface) rotate relative to each other at the rotation detection position B can be detected. Therefore, the amount of deformation in which the rod body 12 is bent and twisted can be obtained based on the amount of movement and the amount of rotation.

ここで、掘削ロッド１のロッド本体１２の変形量を取得できれば、掘削ロッド１にかかっている負荷（トルク）を取得できる。従って、掘削時に掘削ロッド１にかかる負荷によりロッド本体１２が破損することを回避できる。また、掘削ロッド１にかかる負荷を積算しておけば、掘削ロッド１の交換時期などを推定できる。
さらに、掘削時に掘削ロッド１にかかっている負荷（トルク）を取得すれば、掘削ロッド１が掘削している地盤の粘度や比重を取得することも可能となる。 Here, if the amount of deformation of the rod body 12 of the excavation rod 1 can be acquired, the load (torque) applied to the excavation rod 1 can be acquired. Therefore, it is possible to prevent the rod body 12 from being damaged by the load applied to the excavation rod 1 during excavation. Further, if the load applied to the excavation rod 1 is integrated, the replacement time of the excavation rod 1 can be estimated.
Further, if the load (torque) applied to the excavation rod 1 at the time of excavation is acquired, it is possible to acquire the viscosity and the specific gravity of the ground excavated by the excavation rod 1.

また、本例では、変形検出器１５は筒状のロッド本体１２の内周側に取り付けられている。従って、第１変形検出器１５および第２変形検出器１５はロッド本体１２により外側から保護される。よって、掘削時に、変形検出器１５が破損することがない。 Further, in this example, the deformation detector 15 is attached to the inner peripheral side of the tubular rod body 12. Therefore, the first deformation detector 15 and the second deformation detector 15 are protected from the outside by the rod body 12. Therefore, the deformation detector 15 is not damaged during excavation.

さらに、本例では、第１移動量検出器３１および第２移動量検出器３３は、計測ロッド２１に固定された移動量検出用磁石４１と、ベース部材２４に固定された移動量検出用磁気センサ４２とを備える。第１回転量検出器３２および第２回転量検出器３４は、計測ロッド２１に固定された回転量検出用磁石４６と、ベース部材２４に固定された回転量検出用磁気センサ４７とを備える。これにより、第１移動量検出器３１および第２移動量検出器３３は、計測ロッド２１とロッド本体１２（内周面）とが相対移動する移動量を非接触で検出できる。また、第１回転量検出器３２および第２回転量検出器３４は、計測ロッド２１とロッド本体１２（内周面）とが相対回転する回転量を非接触で検出できる。従って、ロッド本体１２に過大な撓みや捩じれが発生した場合でも第１移動量検出器３１、第２移動量検出器３３、第１回転量検出器３２および第２回転量検出器３４が破損することがない。 Further, in this example, the first movement amount detector 31 and the second movement amount detector 33 have a movement amount detection magnet 41 fixed to the measuring rod 21 and a movement amount detection magnet fixed to the base member 24. It is equipped with a sensor 42. The first rotation amount detector 32 and the second rotation amount detector 34 include a rotation amount detection magnet 46 fixed to the measuring rod 21 and a rotation amount detection magnetic sensor 47 fixed to the base member 24. As a result, the first movement amount detector 31 and the second movement amount detector 33 can detect the movement amount in which the measuring rod 21 and the rod body 12 (inner peripheral surface) move relative to each other in a non-contact manner. Further, the first rotation amount detector 32 and the second rotation amount detector 34 can detect the rotation amount in which the measuring rod 21 and the rod body 12 (inner peripheral surface) rotate relative to each other in a non-contact manner. Therefore, even if excessive bending or twisting occurs in the rod body 12, the first movement amount detector 31, the second movement amount detector 33, the first rotation amount detector 32, and the second rotation amount detector 34 are damaged. Never.

また、本例では、第１移動検出位置Ａで移動量を検出する第１移動量検出器３１と、第２移動検出位置Ｃで移動量を検出する第２移動量検出器３３とを備え、これら２つの移動量検出器３１、３３が検出する計測ロッド２１とロッド本体１２と相対的な移動量の感度が異なる。従って、一つの移動量検出器を設置して、移動量検出器から出力される信号Ｓ１のゲインを変化させて感度調整を行う場合と比較して、ＳＮ比を大きくすることが容易であり、移動量を精度よく検出できる。 Further, in this example, a first movement amount detector 31 that detects the movement amount at the first movement detection position A and a second movement amount detector 33 that detects the movement amount at the second movement detection position C are provided. The sensitivity of the movement amount relative to the measurement rod 21 and the rod body 12 detected by these two movement amount detectors 31 and 33 is different. Therefore, it is easy to increase the SN ratio as compared with the case where one movement amount detector is installed and the gain of the signal S1 output from the movement amount detector is changed to adjust the sensitivity. The amount of movement can be detected accurately.

同様に、本例では、第１回転検出位置Ｂで回転量を検出する第１回転量検出器３２と、第２回転検出位置Ｄで回転量を検出する第２回転量検出器３４とを備え、これら２つの回転量検出器３２、３４が検出する計測ロッド２１とロッド本体１２と相対的な回転量の感度が異なる。従って、一つの回転量検出器を設置して、回転量検出器から出力される信号Ｓ２のゲインを変化させて感度調整を行う場合と比較して、ＳＮ比を大きくすることが容易であり、回転量を精度よく検出できる。 Similarly, in this example, the first rotation amount detector 32 that detects the rotation amount at the first rotation detection position B and the second rotation amount detector 34 that detects the rotation amount at the second rotation detection position D are provided. The sensitivity of the relative rotation amount is different between the measuring rod 21 detected by these two rotation amount detectors 32 and 34 and the rod body 12. Therefore, it is easy to increase the SN ratio as compared with the case where one rotation amount detector is installed and the gain of the signal S2 output from the rotation amount detector is changed to adjust the sensitivity. The amount of rotation can be detected accurately.

また、既製杭を施工する場合、杭先端を設置する支持地盤の出現深度を確認する必要がある。現状は、地上に配置したオーガー５（駆動装置）によって、掘削ロッド１を当該ロッド本体１２の軸線Ｌ回りに回転させて掘削ヘッド１１により地面７から地盤を掘削するときのオーガー５にかかる掘削抵抗の電流値の変化（地盤が硬くなると電流値は大きくなる）や区間毎の電流値の積算値の変化（地盤が硬くなると積算電流値は大きくなる）により、支持層の到達を判断している。この場合、掘削深度が深くなると、掘削ロッド１の重量が増えたり、掘削ロッド１の全長にかかる摩擦抵抗が大きくなってしまい、これらにより地上７に配置したオーガー５によってロッド本体１２を当該ロッド本体１２の軸線Ｌ回りに回転させるための電流値が大きくなり、先端地盤の掘削に要する電流値等が微妙に変化する場合もあった。このような場合に、ロッド１２の変形データ（、第１第２移動量検出器３１、３３、第１第２回転量検出器３２、３４からのデータ）を、上記の電流値などと比較検討して、総合的に判断して、より正確に支持地盤を特定できる。 In addition, when constructing ready-made piles, it is necessary to confirm the depth of appearance of the supporting ground on which the tip of the pile is installed. Currently, the excavation resistance applied to the auger 5 when the excavation rod 1 is rotated around the axis L of the rod body 12 by the auger 5 (driving device) arranged on the ground and the ground is excavated from the ground 7 by the excavation head 11. The arrival of the support layer is judged by the change of the current value of (the current value increases when the ground becomes hard) and the change of the integrated value of the current value for each section (the integrated current value increases when the ground becomes hard). .. In this case, as the excavation depth becomes deeper, the weight of the excavation rod 1 increases and the frictional resistance applied to the entire length of the excavation rod 1 increases. The current value for rotating around the axis L of 12 becomes large, and the current value required for excavation of the tip ground may change slightly. In such a case, the deformation data of the rod 12 (data from the first and second movement amount detectors 31, 33 and the first and second rotation amount detectors 32 and 34) is compared and examined with the above current value and the like. Then, it is possible to make a comprehensive judgment and identify the supporting ground more accurately.

５．他の実施形態 5. Other embodiments

前記実施形態において、第１移動量検出器３１および第２移動量検出器３３は、ベース部材２４に固定された移動量検出用磁石４１と、計測ロッド２１に固定された移動量検出用磁気センサ４２とを備えてもよい。また、第１回転量検出器３２および第１回転量検出器３４は、ベース部材２４に固定された回転量検出用磁石４６と、計測ロッド２１に固定された回転量検出用磁気センサ４７とを備えてもよい。このようにしても、計測ロッド２１とロッド本体１２（内周面）とが相対移動する移動量を非接触で検出できる。また、計測ロッド２１とロッド本体１２（内周面）とが相対回転する回転量を非接触で検出できる。従って、ロッド本体１２に過大な撓みや捩じれが発生した場合でも第１移動量検出器３１、第１回転量検出器３２、第２移動量検出器３３、第２回転量検出器３４が破損することがない。 In the above embodiment, the first movement amount detector 31 and the second movement amount detector 33 are a movement amount detection magnet 41 fixed to the base member 24 and a movement amount detection magnetic sensor fixed to the measuring rod 21. 42 may be provided. Further, the first rotation amount detector 32 and the first rotation amount detector 34 have a rotation amount detection magnet 46 fixed to the base member 24 and a rotation amount detection magnetic sensor 47 fixed to the measuring rod 21. You may prepare. Even in this way, the amount of movement between the measuring rod 21 and the rod body 12 (inner peripheral surface) can be detected in a non-contact manner. Further, the amount of rotation in which the measuring rod 21 and the rod body 12 (inner peripheral surface) rotate relative to each other can be detected in a non-contact manner. Therefore, even if excessive bending or twisting occurs in the rod body 12, the first movement amount detector 31, the first rotation amount detector 32, the second movement amount detector 33, and the second rotation amount detector 34 are damaged. Never.

また、前記実施形態において、ベース部材２４を省略して、固定部材２２および複数の支持部材２３を直接ロータ本体の内壁面１２ａに固定してもよい。但し、上記の例のように、固定部材２２および複数の支持部材２３をベース部材２４に固定して、ベース部材２４を介して内壁面１２ａに固定すれば、変形検出器１５をロッド本体１２の内周側に設置することが容易となる。 Further, in the above embodiment, the base member 24 may be omitted, and the fixing member 22 and the plurality of support members 23 may be directly fixed to the inner wall surface 12a of the rotor main body. However, as in the above example, if the fixing member 22 and the plurality of support members 23 are fixed to the base member 24 and fixed to the inner wall surface 12a via the base member 24, the deformation detector 15 can be attached to the rod body 12. It will be easy to install on the inner circumference side.

ここで、上記の例では、変形検出器１５は、軸線Ｌ方向で離間する第１移動量検出器３１および第２移動量検出器３３を備えるが、いずれか一方の移動量検出器を省略して、移動量検出器を一つにしてもよい。また、移動量検出器の数を増やして、３以上としてもよい。この場合には、例えば、軸線Ｌ方向で第１移動検出位置Ａと第２移動検出位置Ｃとの間に第３移動検出位置を設定して第３第動量検出器を配置する。同様に、変形検出器１５は、軸線Ｌ方向で離間する第１回転量検出器３２および第２回転量検出器３４を備えるが、いずれか一方の回転量検出器を省略して、回転量検出器を一つにしてもよい。また、回転量検出器の数を増やして、３以上としてもよい。この場合には、例えば、軸線Ｌ方向で第１回転検出位置Ｂと第２回転検出位置Ｄとの間に第３回転検出位置を設定して、第３移動量検出器を配置する。ここで、移動量検出器および移動量検出器の組を増加させた場合には、信号伝送機構５１は、移動量検出器および移動量検出器の組の数に対応する数の通信部を備えるものとする。 Here, in the above example, the deformation detector 15 includes a first movement amount detector 31 and a second movement amount detector 33 that are separated in the axis L direction, but one of the movement amount detectors is omitted. Therefore, one movement amount detector may be used. Further, the number of movement amount detectors may be increased to 3 or more. In this case, for example, a third movement detection position is set between the first movement detection position A and the second movement detection position C in the axis L direction, and the third momentum detector is arranged. Similarly, the deformation detector 15 includes a first rotation amount detector 32 and a second rotation amount detector 34 that are separated in the axis L direction, but the rotation amount detection is omitted by omitting one of the rotation amount detectors. You may have one vessel. Further, the number of rotation amount detectors may be increased to 3 or more. In this case, for example, the third rotation detection position is set between the first rotation detection position B and the second rotation detection position D in the axis L direction, and the third movement amount detector is arranged. Here, when the number of sets of the movement amount detector and the movement amount detector is increased, the signal transmission mechanism 51 includes a number of communication units corresponding to the number of sets of the movement amount detector and the movement amount detector. It shall be.

また、前記実施形態において、変形検出器１５として、内壁面１２ａにおいて軸線Ｌを間に挟んだ一方側および他方側にそれぞれ配置された２つの変形検出器１５を備えるものとすることができる。例えば、軸線Ｌ回りで１８０°離間する位置に２つの変形検出器１５を配置することができる。このようにすれば、２つの変形検出器１５のそれぞれによって検出される移動量の差分に基づいて、ロッド本体１２がいずれの方向に撓んでいるかを取得できる。また、２つの変形検出器１５のそれぞれによって検出される移動量の差分に基づいて、ロッド本体１２の曲りの程度を把握できる。 Further, in the above-described embodiment, the deformation detector 15 may be provided with two deformation detectors 15 arranged on one side and the other side of the inner wall surface 12a with the axis L sandwiched between them. For example, two deformation detectors 15 can be arranged at positions separated by 180 ° around the axis L. In this way, it is possible to acquire in which direction the rod body 12 is bent based on the difference in the amount of movement detected by each of the two deformation detectors 15. Further, the degree of bending of the rod body 12 can be grasped based on the difference in the amount of movement detected by each of the two deformation detectors 15.

また、前記実施形態において、変形検出器１５として、内壁面１２ａにおいて軸線Ｌ回りの等角度間隔に配置された４つの変形検出器１５を備えるものとすることができる。図７は４つの変形検出器１５を備える変形例の掘削ロッド６０の説明図である。図７では、ロッド本体１２を軸線Ｌ方向から見ている。また、ロッド本体１２を掘削ヘッド１１が取り付けられる端部の側から見ている。変形例の掘削ロッド６０によれば、４つの変形検出器１５のそれぞれによって検出される移動量に基づいて、ロッド本体１２の軸線Ｌ方向の伸縮を検出できる。また、４つの変形検出器１５のそれぞれによって検出される回転量に基づいて、ロッド本体１２の捩じれを精度よく検出できる。例えば、４つの変形検出器１５のそれぞれによって検出される回転量の平均を取得することにより、ロッド本体１２の捩じれを精度よく検出できる。 Further, in the above-described embodiment, the deformation detector 15 may be provided with four deformation detectors 15 arranged at equal intervals around the axis L on the inner wall surface 12a. FIG. 7 is an explanatory diagram of a deformation example excavation rod 60 including four deformation detectors 15. In FIG. 7, the rod body 12 is viewed from the axis L direction. Further, the rod body 12 is viewed from the side of the end to which the excavation head 11 is attached. According to the excavation rod 60 of the deformation example, expansion and contraction of the rod body 12 in the axis L direction can be detected based on the movement amount detected by each of the four deformation detectors 15. Further, the twist of the rod body 12 can be accurately detected based on the amount of rotation detected by each of the four deformation detectors 15. For example, by acquiring the average of the amount of rotation detected by each of the four deformation detectors 15, the twist of the rod body 12 can be detected with high accuracy.

また、前記実施形態において、第１第２移動検出器３１、３３、第１第２回転量検出器３２、３４、固定部材２２、支持部材２３の構成は他の構成とすることもできる（図示していない）。 Further, in the above-described embodiment, the configurations of the first and second movement detectors 31, 33, the first second rotation amount detectors 32, 34, the fixing member 22, and the support member 23 may be other configurations (FIG. Not shown).

１、６０掘削ロッド
１Ａ掘削ロッドの掘削姿勢
２杭穴
３杭打ち機
４マスト
５オーガー
７地面
１１掘削ヘッド
１２ロッド本体
１２ａロッド本体の内壁面
１５変形検出器
１８流通管
２１計測ロッド
２１、２２固定部材
２３支持部材
２４ベース部材
２４ａベース部材の外側面
２４ｂベース部材の内側面
２５固定部材側固定部
２６計測ロッド固定部
２８支持部材側固定部
２９計測ロッド支持部
２９ａ貫通穴
３１第１移動量検出器
３２第１回転量検出器
３３第２移動量検出器
３４第２回転量検出器
３７ギャップ
４１移動量検出用磁石
４１ａ着磁分極線
４２移動量検出用磁気センサ
４２ａセンサ面
４３中心孔（移動量検出用磁石）
４５ホルダ
４６回転量検出用磁石
４６ａ着磁分極線
４７回転量検出用磁気センサ
４７ａセンサ面
５１信号伝送機構
５２デジタル通信線
５３第１通信部
５４第２通信部
５５Ａ／Ｄ変換器
５６デジタル通信制御部
Ａ第１移動検出位置
Ｂ第１回転検出位置
Ｃ第２移動検出位置
Ｄ第２回転検出位置
Ｌ軸線（ロッド本体軸線）
Ｌ１軸線（計測ロッド軸線）
Ｓ１移動量検出器からの信号
Ｓ２回転量検出器からの信号 1,60 Excavation rod 1A Excavation posture of excavation rod 2 Pile hole 3 Pile driving machine 4 Mast 5 Auger 7 Ground 11 Excavation head 12 Rod body 12a Inner wall surface of rod body 15 Deformation detector 18 Flow pipe 21 Measuring rod 21, 22 Fixed Member 23 Support member 24 Base member 24a Outer surface of base member 24b Inner side surface of base member 25 Fixing member side fixing part 26 Measuring rod fixing part 28 Supporting member side fixing part 29 Measuring rod support part 29a Through hole 31 First movement amount detection Instrument 32 1st rotation amount detector 33 2nd movement amount detector 34 2nd rotation amount detector 37 Gap 41 Movement amount detection magnet 41a Magnetization polarization line 42 Movement amount detection magnetic sensor 42a Sensor surface 43 Center hole (movement) Magnet for quantity detection)
45 Holder 46 Rotation amount detection magnet 46a Magnetization polarization line 47 Rotation amount detection magnetic sensor 47a Sensor surface 51 Signal transmission mechanism 52 Digital communication line 53 First communication unit 54 Second communication unit 55 A / D converter 56 Digital communication Control unit A 1st movement detection position B 1st rotation detection position C 2nd movement detection position D 2nd rotation detection position L Axis line (rod body axis)
L1 axis (measurement rod axis)
S1 Signal from the movement amount detector S2 Signal from the rotation amount detector

Claims

In an excavation rod having an excavation head and a cylindrical rod body to which the excavation head is attached at a lower end portion, the rod body is rotated to excavate a pile hole in the ground by the excavation head.
The rod body has a deformation detector attached to an inner wall surface to detect deformation of the rod body.
The deformation detector is
A measuring rod arranged on the inner wall surface side of the rod body and extending in the axial direction of the rod body,
A fixing member having a fixing member-side fixing portion fixed to the inner wall surface and a measuring rod fixing portion to which the measuring rod is fixed on the inner peripheral side of the fixing member-side fixing portion.
The measurement rod can be moved in the direction of the measurement rod axis of the measurement rod and can be rotated around the rod axis on the inner peripheral side of the support member side fixing portion fixed to the inner wall surface and the support member side fixing portion. A support member having a measuring rod support portion to support,
A movement amount detector that detects a movement amount in which the inner wall surface and the measurement rod move relative to each other in the measurement rod axial direction at a movement detection position separated from the measurement rod fixing portion in the axial direction.
A rotation amount detector that detects the amount of rotation in which the inner wall surface and the measurement rod rotate relative to each other around the measurement rod axis at a rotation detection position separated from the measurement rod fixing portion in the axial direction.
A drilling rod with a deformation detector, characterized by being equipped with.

It has a long base member that is fixed to the inner wall surface of the rod body and extends in the axial direction of the rod body.
The deformation detector according to claim 1, wherein the fixing portion on the fixing member side and the fixing portion on the support member side are fixed to the base member and fixed to the inner wall surface via the base member. With excavation rod.

The movement amount detector includes a movement amount detection magnet fixed to one of the measuring rod and the base member, and a movement amount detection magnetic sensor fixed to the other.
The second aspect of claim 2, wherein the rotation amount detector includes a rotation amount detection magnet fixed to one of the measuring rod and the base member, and a rotation amount detection magnetic sensor fixed to the other. Drilling rod with deformation detector.

A second movement that detects a second movement amount in which the inner wall surface of the rod body and the measurement rod move relative to each other in the measurement rod axial direction at the second movement detection position between the measurement rod fixing portion and the movement detection position. With a quantity detector,
At the second rotation detection position between the measurement rod fixing portion and the rotation detection position, the second rotation amount in which the inner wall surface of the rod body and the measurement rod rotate relative to each other around the measurement rod axis is detected. The excavation rod with a deformation detector according to any one of claims 1 to 3, further comprising a rotation amount detector (2).

The invention according to any one of claims 1 to 4, wherein the deformation detector includes a plurality of the deformation detectors arranged on one side and the other side of the inner wall surface with an axis sandwiched between them. Excavation rod with the described deformation detector.