JP5357640B2 - Drilling rig - Google Patents

Description

  The present invention relates to an excavation apparatus for excavating the ground in order to form a mountain retaining wall, a water blocking wall, a foundation pile on the ground, or to improve the ground.

  Conventionally, it has been known to form a soil solidified body by mixing rocks and solidified material with excavated earth and sand on the ground in order to form mountain retaining walls, waterstop walls, foundation piles on the ground, or to improve the ground. ing. And as a conventional apparatus for forming a soil consolidated body, a plurality of excavation shafts are mounted so as to be movable up and down along a crawler crane leader installed on the ground, and a bit is provided at the tip of each excavation shaft and excavation is performed. A stirring means such as a stirring blade or a stirring blade is provided partially in the vertical direction of the shaft, and further, a jet part for jetting a solidified material such as cement milk is provided on a bit or a drilling shaft.

  However, since the above-mentioned conventional apparatus has the excavation shaft attached to the leader of a crawler crane installed on the ground so as to be movable up and down, a leader having a long vertical length is required on the ground, and Long excavation shafts move up and down along the way, so the stability is poor and there is a risk of falling. In addition, in a site where there are obstacles in the tunnel or above, there is a problem that the leader and excavation shaft that are long in the vertical direction cannot be arranged and cannot be used in such a place, Since the excavated soil for the volume of the inserted excavation shaft overflows on the ground, as the depth of the excavation shaft increases, the volume of the excavated shaft inserted into the ground increases proportionally and the amount of excavated soil overflowing on the ground increases. There is a problem of becoming.

  Further, in the above conventional example, in the case where a bit is provided at the tip of a plurality of excavating shafts that are long in the vertical direction, the positions of the bits at the lower end of the adjacent excavating shaft are shifted up and down and are adjacent in plan view. The rotation trajectory drawn by the bits is partly overlapped so that there is no left-over portion between adjacent bits. In this conventional example, the rotation drawn by the adjacent bits in plan view is used. The part where the trajectory partly overlaps is a part where the circle and the circle partly overlap in plan view, so that the excavation width is narrow and the excavation width cannot be excavated into a rectangular shape in plan view There is. Therefore, there is a problem that the width of each part in the plan view such as the mountain retaining wall, the water blocking wall, the foundation pile, etc. to be formed cannot be made constant, and the strength, water stoppage, etc. are not made constant.

  Also, relatively large stones that could not be crushed by the lower bits pass between the lower bits and between the lower bits and the intermediate bits located above the lower bits. Try to pass through the gap. By the way, the bit provided at the bottom end of the long excavating shaft has a blade structure that excavates the lower earth and sand, so there is a crushing action on the earth and sand under the bit. There is no crushing action on earth and sand located on the bit. Therefore, for a relatively large stone that tries to pass between a lower bit and an intermediate bit, only the intermediate bit located above it will crush and try to pass The lower bit against the stone does not crush. For this reason, relatively large stones that attempt to pass between the lower bit and the intermediate bit will pass without being crushed, or the clogged bit will rotate between the lower bit and the intermediate bit. The problem that it becomes impossible to occur.

  In addition, without using a long excavating shaft up and down, two rotating shafts are placed sideways at the bottom of the device body that is suspended from the ground by a linear material and inserted into the ground and descends or rises in the ground. Patent Documents 1 and 2 propose a drilling device in which rotating bodies with rotating blades are arranged side by side through a gap.

  In these conventional examples shown in Patent Documents 1 and 2, since the apparatus main body suspended from the ground by a linear material is inserted into the ground and excavated by a rotating body with a rotating blade, it is necessary to use a long excavating shaft vertically. There is no risk of overturning, and even if the depth of excavation is deep, there is no such thing as a proportional increase in the amount of excavated soil over the ground, as in the case of using a long excavating shaft. The amount of excavated soil that overflows is small, and a square excavation hole can be formed in plan view.

  However, when excavating the ground by rotating two rotating bodies with left and right rotating blades with the rotation axis turned sideways, if the gap between the rotating bodies with left and right rotating blades is small, the rotating body with rotating blades was provided. There is a problem that relatively large stones or the like that have not been excavated by the rotary blades are stuck in the right and left rotary bodies with the rotary blades and become unable to rotate. On the other hand, if the left and right rotating blades are passed through without being bitten, it is necessary to increase the gap between the left and right rotating blades. The gap between them is not excavated, and there is a problem that unremained digging occurs, and relatively large stones that have not been excavated by the rotating body with a rotating blade pass through without being crushed. There's a problem.

Japanese Patent Laid-Open No. 07-158055 JP 2006-57446 A

  The present invention was invented in view of the problems of the above-described conventional example, and a relatively large stone can be reliably obtained without clogging stones between the lower rotating bodies with rotating blades or leaving no digging. An object of the present invention is to provide an excavation apparatus that can excavate a square excavation hole in a plan view easily and accurately while being crushed.

  In order to solve the above problems, the present invention has the following configuration.

  The excavator of the present invention has a plurality of rotations in which a rotating shaft 4 is turned sideways at the lower part of an apparatus body 3 that is suspended from the ground by a wire 1 and inserted into the ground 2 and descends or rises in the ground 2. The lower rotary body 5 with a blade is juxtaposed via the first gap 6, and the intermediate rotary body 8 with the rotary blade with the rotary shaft 7 turned sideways is disposed above the first gap 6. A second gap 9 is formed between the lower rotary body 5 and the intermediate rotary body 8 with a rotary blade.

  By having such a configuration, the apparatus body 3 suspended from the ground by a wire 1 such as a wire, chain, chain, etc. is inserted into the ground 2 and excavated by the lower rotating body 5 with a rotary blade, By excavating the portion between the lower rotary body 5 with the rotary blade by the lower rotary body 5 with the rotary blade, the lower rotary body 5 with the rotary blade is lowered in the ground 2 by the above-described excavation and the own weight of the apparatus main body 3, and remains in a rectangular shape in plan view Can be drilled into. When the lower rotary body 5 with the rotary blade is rotated and excavated, the relatively large stone that could not be crushed small by the lower rotary body 5 with the rotary blade is the first gap between the lower rotary body 5 with the rotary blade. 6 at this time, since it passes between the rotary blades 5a provided in the lower rotating body 5 with the left and right rotary blades, the rotary blades 5a and 5a on both sides opposed to the left and right at the time of passing are used. The crushing action is performed from both the left and right sides. Here, the stone that has been crushed to some extent passes through the second gap 9 in which the lower rotary body 5 with the rotary blade and the intermediate rotary body 8 with the rotary blade face diagonally up and down. Since it passes between the rotary blade 5a provided in the lower rotary body 5 with the rotary blade and the rotary blade 8a provided in the intermediate rotary body 8 with the rotary blade, the rotary blades 5a, 8a facing diagonally up and down at the time of passage are used. The crushing action is performed from both sides in the diagonally up and down direction. Thus, the crushing action from both the left and right sides of the rotating blades 5a, 5a on both sides of the first gap 6 passes through a relatively large stone that has not been sufficiently crushed, or passes through the first gap 6 without being crushed. When the relatively large stone passes through the second gap 9, it can be crushed from both sides by the rotary blades 5a, 8a facing diagonally up and down. Therefore, even if the gap width of the first gap 6 is not extremely narrowed, a relatively large stone that could not be crushed at the time of excavation of the lower rotating body 5 with the rotating blade can be reliably crushed in the subsequent stage. It is possible to make the gap width such that a relatively large stone is not clogged in one gap 6.

  In addition, the gap width of the second gap 9 is preferably substantially the same as or narrower than the gap width of the first gap 6.

  By adopting such a configuration, a relatively large stone that could not be crushed small by the lower rotating body 5 with the rotating blade is first rotated from both the left and right sides when passing through the first gap 6 as the first stage. After being crushed by the blade 5a and then passing through the second gap 9 as the second stage, it is further finely crushed by the rotary blades 5a and 8a from both sides in the diagonally up and down direction.

  Moreover, it is preferable that the gap width of the second gap 9 is variable.

  By setting it as such a structure, according to the state of the ground 2 which is going to excavate, the clearance width of the 2nd clearance gap 9 can be varied, and it can be set as the clearance width corresponding to the ground 2. FIG.

  Further, the intermediate rotary member 8 with the rotary blade is movable in the direction in which the second gap 9 becomes wider from the position where the second gap 9 becomes the minimum width. It is preferable that a force to move in the direction that makes the minimum width is applied.

  By adopting such a configuration, when a relatively large stone passes through the second gap 9, it is not sufficiently crushed by the rotary blades 5 a and 8 a from both sides in the diagonally up and down direction, and clogs the second gap 9. In this case, the intermediate rotating body 8 with the rotary blade moves and the gap width of the second gap 9 becomes wider, so that a relatively large stone can be forced to pass through. As a result, a relatively large stone bites into the lower rotating body 5 with rotating blades on both sides and clogs the second gap 9, and the lower rotating body 5 with rotating blade and the intermediate rotating body 8 with rotating blade cannot be rotated. Can be avoided.

  Further, the intermediate rotating body 8 with the rotary blade becomes movable in the direction in which the width of the second gap 2 becomes wider from the position where the second gap 9 becomes the minimum width, and the moving position of the intermediate rotating body 8 with the rotary blade is adjusted. It is preferable that the moving position adjusting means 10 is provided and the second gap 9 width is adjustable by adjusting the movement of the intermediate rotating body 8 with the rotary blade.

  By adopting such a configuration, the gap width of the second gap 9 is adjusted by the movement position adjusting means 10 according to the state of the ground 2 to be excavated, and the optimum gap width corresponding to the ground 2 is obtained. Can do.

  Since the present invention is configured as described above, the ground between the lower rotating bodies with the rotating blades can be excavated by the intermediate rotating body with the rotating blades, so that a square excavation hole in plan view can be accurately formed without leaving an excavation. Moreover, since the ground between the lower rotating bodies with rotating blades can be excavated with an intermediate rotating body with rotating blades, the gap width of the first gap is sufficiently crushed when excavating the ground with the lower rotating body with rotating blades. It becomes possible to make the gap width so that relatively large stones that could not be bitten are stuck. In addition, when excavating the ground with a lower rotating body with a rotating blade, relatively large stones that could not be sufficiently crushed can be finely crushed by rotating blades from both sides when passing through the first gap and the second gap. it can. In this way, the present invention provides a rectangular excavation hole in a simple and accurate plan view while reliably crushing relatively large stones without clogging stones between the lower rotating bodies with rotating blades or leaving no digging. Can drill

It is a schematic front view of one Embodiment of this invention. It is a schematic side view same as the above. It is a schematic sectional drawing which shows the state which excavates the ground same as the above. It is a schematic front view of other embodiment same as the above. It is a schematic front view of other embodiment same as the above. It is a schematic front view of other embodiment same as the above. It is a schematic front view of other embodiment same as the above.

  Hereinafter, the present invention will be described based on embodiments shown in the accompanying drawings.

  1 and 2 show an example of an apparatus used in the present invention.

  At the lowermost end of the apparatus main body 3, a plurality of lower rotating bodies 5 with rotating blades whose rotating shafts 4 are oriented horizontally are arranged side by side through a first gap 6.

  In the embodiment shown in the accompanying drawings, the lower rotary body 5 with a rotary blade in which the rotary shaft 4 is laterally arranged on both the left and right sides of the lowermost end of the apparatus main body 3 is juxtaposed via a first gap 6.

  A plurality of rotary blades 5a project from the outer peripheral portion of the lower rotary body 5 with rotary blades. A plurality of the rotary blades 5a project in the circumferential direction and the axial direction.

  The apparatus main body 3 is further provided with an intermediate rotary body 8 with a rotary blade in which the rotary shaft 7 is in a horizontal direction above the first gap 6 formed between the lower rotary bodies 5 with the rotary blade.

  A plurality of rotary blades 8a project from the outer peripheral portion of the intermediate rotary member 8 with rotary blades. A plurality of the rotary blades 8a project in the circumferential direction and the axial direction.

  As described above, by providing the intermediate rotating body 8 with the rotary blade at the upper position of the first gap 6, the second rotating body 5 with the rotary blade on both the left and right sides and the intermediate rotating body 8 with the rotary blade are second. A gap 9 is formed. That is, the lower rotary body 5 with the rotary blades and the intermediate rotary body 8 with the rotary blades face each other in the diagonally up and down direction via the second gap 9. That is, the center of each rotating shaft 4 of the lower rotating body 5 with the left and right rotating blades and the center of the rotating shaft 7 of the intermediate rotating body 8 with the rotating blade are located at the apex of the triangle.

  The lower rotary body 5 with a rotary blade and the intermediate rotary body 8 with a rotary blade are both driven by a rotation driving means. The rotation driving means is provided in the lower rotary body 5 with a rotary blade or the intermediate rotary body 8 with a rotary blade, or provided in the apparatus main body 3.

  By excavating the ground 2 while rotating the lower rotating body 5 with left and right rotating blades and the intermediate rotating body 8 with intermediate rotating blades, a rectangular excavation hole 14 is excavated in a plan view.

  The apparatus main body 3 is suspended by a linear material 1 such as a wire, a chain, or a chain, and the apparatus main body 3 is provided with a consolidated material injection portion 15 for injecting the consolidated material. Further, a consolidated material supply hose (not shown) for supplying the consolidated material is connected to the consolidated material injection unit 15, and is connected to a consolidated material supply device (not shown) installed on the ground. Connected. The consolidated material supply hose is attached along the linear material 1. The linear material 1 is suspended from the ground by a construction machine installed on the ground, and the linear material 1 is wound around a drum provided in the construction machine.

  In order to form the excavation hole 14 in which the soil 2 is excavated by excavating the ground 2 using the apparatus as described above, the following process is performed.

  With the apparatus main body 3 suspended from the construction machine installed on the ground with the wire 1, as shown in FIG. 3, the lower rotary body 5 with both rotary blades and the intermediate rotary body 8 with rotary blades are rotated. While excavating the ground, the apparatus main body 3 is inserted into the ground by the excavation and the weight of the apparatus main body 3.

  In this case, the excavation is performed while injecting a cemented material such as cement milk, a mixture containing cement milk as a main material, a synthetic resin solution, or a mixture of a synthetic resin solution and another material from the consolidated material injection unit 15. . Therefore, at the same time as excavation, the agitation and mixing of the excavated sediment and the caking agent is performed.

  In excavation of the ground 2, first, the ground 2 is excavated by the lower rotating bodies 5 with rotating blades on the left and right sides located at the lowermost end, and then the ground 2 between the lower rotating bodies 5 with the left and right rotating blades is rotated. Excavation is performed with the intermediate rotating body 8 attached. As a result, it is possible to excavate the excavation hole 14 having a square shape in plan view with the lower rotary body 5 with the rotary blades on the left and right sides and the intermediate rotary body 8 with the rotary blades without leaving a dug.

  Further, the ground 2 is first excavated by the lower rotating body 5 with rotating blades on the left and right sides at the bottom as described above, and stones and the like contained in the ground 2 are crushed by the lower rotating body 5 with rotating blades at the time of excavation. .

  However, the stones that could not be sufficiently crushed during excavation of the ground 2 by the lower rotary body 5 with the rotary blade try to pass through the first gap 6 between the lower rotary bodies 5 with the rotary blade.

  Here, if the gap width of the first gap 6 of the lower rotary body 5 with the rotary blade is too narrow, there is no fear of digging, but since the gap width is too narrow, the lower rotary body 5 with the rotary blade can be sufficiently crushed. The stone that did not exist bites into the lower rotating body 5 with the left and right rotating blades.

  Therefore, in the present invention, the first gap 6 is prevented from biting into the relatively large lower rotary body 5 with both rotary blades that could not be crushed small by the lower rotary body 5 with rotary blades. The gap dimension between them is secured to some extent, and even if a digging remains is generated between the left and right lower rotating bodies 5 with rotating blades, the intermediate rotating body 8 with rotating blades is excavated so that no digging remains.

  Since the gap between the first gaps 6 is secured to a certain extent in this way, the stone that could not be sufficiently crushed by the lower rotary body 5 with rotary blades is bitten into the lower rotary body 5 with both rotary blades and The first gap 6 between the lower rotary bodies 5 with both rotary blades passes through without being clogged with one gap 6 or the crushing action is applied by the rotary blades 5a and 5a from both sides when passing. It is crushed into small pieces.

  The stone that passes through the first gap 6 between the lower rotating bodies 5 with both rotary blades as described above, or is crushed by the rotary blades 5a and 5a from both the left and right sides when passing, 2 The gap 9 is reached.

  In this second gap 9, since it passes between the rotary blade 5 a provided in the lower rotary body 5 with the rotary blade and the rotary blade 8 a provided in the intermediate rotary body 8 with the rotary blade that are opposed diagonally up and down, The crushing action is performed from both sides in the diagonally up and down direction by the rotary blades 5a and 8a facing diagonally up and down, and further crushed into small pieces.

  The gap width of the second gap 9 is preferably set to be substantially the same as or narrower than the gap width of the first gap 6. Thereby, the relatively large stone that could not be crushed small by the lower rotary body 5 with the rotary blade is first crushed by the rotary blade 5a from the left and right sides when passing through the first gap 6 as the first stage, Next, when passing through the second gap 9 as the second stage, the rotary blades 5a and 8a are more effectively and finely crushed from both sides in the diagonally up and down direction.

  In this way, by passing the first gap 6 and the second gap 9 continuously, the crushing action is applied from both the left and right sides by the rotary blades 5a and 5a, and the rotary blade 5a and the rotary blade are subsequently applied obliquely from above and below. In the crushing action by 8a and fine crushing continuously in two stages, in the present invention, three rotations of the lower rotary body 5 with both rotary blades arranged side by side and the intermediate rotary body 8 with rotary blades are arranged side by side. Since the rotary body with blades is arranged in the above positional relationship, the number of members is small and the configuration is simplified.

  As described above, when a relatively large stone passes through the first gap 6 and the second gap 9 continuously, it is gradually crushed and filled with a mixture mixed with other excavated sediment and consolidated material. The excavation hole 14 is dug to a predetermined depth. When the apparatus main body 3 is lowered to a predetermined depth, the apparatus main body 3 is raised by pulling up the wire 1. In this way, by pulling up the apparatus main body 3 with the wire 1, the excavation hole 14 filled with the mixture 18 of excavation earth and sand having a square or rectangular cross section in the ground is formed. Become.

  During the above-described process, the mixture 18 of excavated soil and consolidated material overflowing the ground is approximately the sum of the amount of bulge of the excavated soil, the amount of injected consolidated material, and the volume of the apparatus main body 3. Thus, there is no fear that the volume of the inserted excavation shaft will increase proportionally as the insertion depth increases, as in the case of inserting a conventional excavation shaft.

  The mixture 18 of the excavated earth and the filling liquid filled in the excavation hole 14 is solidified, so that a soil solidified body is formed in the ground, and the soil solidified body formed in the ground forms a mountain. A stop wall, a water stop wall, foundation pile, or improved ground is formed.

  In the present invention, the gap width of the second gap 9 may be variable.

  FIG. 4 is a schematic configuration diagram of an embodiment in which the second gap 9 is variable. In the present embodiment, an intermediate rotating body 8 with a rotary blade is attached to the apparatus main body 3 so as to be movable in the vertical direction. Specifically, a vertically long guide 16 like a vertically long hole is formed in the apparatus main body 3, and a guided portion 17 provided on the intermediate rotating body 8 with a rotating blade is vertically aligned with respect to the vertically long guide 16. It is mounted movably. A spring force by the spring material 11 is applied downward to the intermediate rotating body 8 with a rotating blade. Normally, the intermediate rotating body 8 with the rotating blade is positioned at the lowermost end of the vertically long guide 16 by the spring force. . That is, this state is the minimum gap width of the second gap 9.

  Normally, excavated soil and relatively large stones pass through the second gap 9 while being crushed from both sides by the rotary blades 5a and 8a, but the load is too large to be crushed and into the second gap 9. When the clogging occurs, the intermediate rotating body 8 with the rotating blade moves upward along the longitudinal guide 16 against the spring force of the spring material 11, and the gap width of the second gap 9 becomes wider, thereby passing In addition, since the gap width is slightly increased, crushing from both sides by the rotary blades 5a and 8a can be easily performed. When the load becomes small, the intermediate rotating body 8 with the rotary blade moves downward along the longitudinal guide 16 again by the spring force of the spring material 11, and the second gap 9 becomes narrow.

  As a result, it is possible to avoid a situation in which the second gap 9 is clogged with stones that cannot be crushed and the lower rotary body 5 with the rotary blade and the intermediate rotary body 8 with the rotary blade cannot be rotated.

  FIG. 5 shows a schematic configuration diagram of another embodiment in which the second gap 9 is variable. In the present embodiment, the intermediate rotary member 8 with a rotary blade is movable in a direction in which the gap width becomes wider from a position where the gap width of the second gap 9 is the minimum width. A moving position adjusting means 10 for adjusting the moving position of the rotating body 8 is provided. Specifically, a vertically long guide 16 like a vertically long hole is formed in the apparatus main body 3, and a guided portion 17 provided on the intermediate rotating body 8 with a rotating blade is vertically aligned with respect to the vertically long guide 16. It is free to move. As described above, the intermediate rotating body 8 with the rotary blade is movable along the longitudinal guide 16, but the intermediate rotating body 8 with the rotary blade is driven by, for example, a hydraulic cylinder, an air cylinder, or the like, which serves as the movement position adjusting means 10. By moving and adjusting the moving position, it can be fixed so as not to move at an arbitrary stop position of the longitudinal guide 16. Thus, the clearance width of the 2nd clearance gap 9 can be adjusted by adjusting the movement position of the intermediate rotary body 8 with a rotary blade. Therefore, according to the state of the ground 2 to be excavated, it is possible to adjust the gap width of the second gap 9 by the movement position adjusting means 10 to obtain an optimum gap width corresponding to the ground 2.

  FIG. 6 shows a schematic configuration diagram of another embodiment of the present invention.

  In the present embodiment, as described above, a plurality of lower rotating bodies 5 with rotating blades with the rotating shaft 4 turned sideways are arranged side by side through the first gap 6 at the lower portion of the apparatus main body 3. An intermediate rotating body 8 with a rotary blade in which the rotary shaft 7 is in a horizontal direction is disposed at an upper position, and a second gap 9 is formed between the lower rotating body 5 with the rotary blade and the intermediate rotary body 8 with the rotary blade. In addition, in addition to this, an example in which a plurality of upper rotating bodies 20 with rotating blades in which the rotating shaft 23 is in the horizontal direction is provided on the upper portion of the apparatus main body 3 is shown. In this example, when the apparatus main body 3 is lowered, the mixture of the earth and sand or finely crushed stone and the caking material that has passed through the second gap 9 as described above is the upper rotating body with a rotating blade in the upper part of the apparatus main body 3. Rotating blades provided on the upper rotating body 20 with rotating blades on both the left and right sides when passing through the third gap 19 which is a gap between the upper rotating bodies 20 with rotating blades. The above mixture is further crushed from both sides by the rotary blades 20a and 20a and stirred and mixed to form a homogeneous mixture.

  Here, with the rotary blade with the rotary shaft 24 turned sideways as shown in FIG. 7 at the lower position or the upper position of the third gap 19 between the upper rotary bodies 20 with the rotary blade arranged side by side on the upper part of the apparatus main body 3. An upper intermediate rotator 21 may be provided. By providing the upper intermediate rotator 21 with the rotary blade in this way, the fourth gap 22 can be formed between the upper rotator 20 with the rotary blade and the upper intermediate rotator 21 with the rotary blade.

  Therefore, when excavated earth and sand or stone passes through the fourth gap 22, the crushing action is performed from both sides by the rotary blade 20a provided on the upper rotary body 20 with the rotary blade and the rotary blade 21a provided on the upper intermediate rotary body 21 with the rotary blade. Is done.

  Of course, also in the embodiment shown in FIGS. 6 and 7, the intermediate rotor 8 with a rotary blade can be moved up and down as shown in FIGS. 4 and 5, and the gap width of the second gap 9 can be made variable. . In addition to this, in the embodiment shown in FIG. 7, the upper intermediate rotating body 21 with a rotating blade may be movable in the vertical direction, and the gap width of the fourth gap 22 may be variable.

DESCRIPTION OF SYMBOLS 1 Linear material 2 Ground 3 Apparatus main body 4 Rotating shaft 5 Lower rotary body with a rotary blade 6 1st clearance 7 Rotary shaft 8 Intermediate rotary body with a rotary blade 9 2nd clearance 10 Moving position adjustment means

Claims (5)

  A plurality of lower rotating bodies with rotating blades having rotating shafts in the lower side of the apparatus main body suspended from the ground by a linear material and inserted into the ground to descend or rise in the ground via the first gap An intermediate rotary body with a rotary blade that is arranged side by side and whose rotation axis is in a lateral direction is disposed above the first gap, and a second gap is provided between the lower rotary body with the rotary blade and the intermediate rotary body with the rotary blade. An excavator characterized in that it is formed.   The excavator according to claim 1, wherein a gap width of the second gap is substantially the same as or narrower than a gap width of the first gap.   The excavator according to claim 1 or 2, wherein the gap width of the second gap is variable.   The intermediate rotary member with a rotary blade is movable in the direction in which the width of the second gap becomes wider from the position where the second gap becomes the minimum width, and the second gap width becomes the minimum width in the intermediate rotary member with the rotary blade. The excavation apparatus according to claim 3, wherein a force to move the drill is applied. An intermediate rotating body with a rotary blade is movable in a direction in which the second gap width is widened from a position where the second gap is the minimum width, and a moving position adjusting means for adjusting the moving position of the intermediate rotating body with the rotary blade is provided, 4. The excavator according to claim 3, wherein the second gap width is adjustable by adjusting the movement of the intermediate rotary member with a rotary blade.

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