JPS61130527A - Boring machine - Google Patents

Abstract

PURPOSE:To excavate the ground below the cutting edge of a sunk well by means of the same bit by a method in which when the ground in the sunk well is excavated, the outer ring bit is contacted with the inner wall of the sunk well, and when the ground below the cutting edge of the sunk well is excavated, the outer ring bit is used in an expanded form. CONSTITUTION:When soil in a sunk well 2 is excavated, the second support arms 8 and 9 are bent toward the first support arm 5, and outer ring bits 12 and 13 are contacted with the inner wall of the sunk well 2. When a pipe 3 is turned while giving a downward propulsion to the pipe 3, the central part of the bottom of pit is excavated by a center bit 4, and the surrounding soil of the bit 4 is excavated by the bits 12 and 13 while being touched by the inner wall of the well 2. When the bits 12 and 13 reache the cutting edge of the well 2, the bits 12 and 13 are expanded outwards because of dergulation of the sunk well 2 to excavate the ground below the cutting edge of the wall 2. By more expanding the bits 12 and 13, the ground inside the wall 12 and below the cutting edge of the well 2 can be excavated by the same bits.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a hole drilling machine, and particularly to a drilling machine that is effective when depositing a well.

Generally, in the well sinking method, the well is suspended and supported, the ground at the bottom is excavated by an excavator inserted inside the well, and then the well is sunk into the ground. In order to sink a well, it is usually necessary to excavate not only the inside of the well, but also the ground below the cutting edge of the well. It had the disadvantage that it was easy to open the blade specifically for excavating the ground below the cutting edge.

This invention eliminates the drawbacks of the conventional ones as described above, and uses a simple mechanism to allow the ground inside the well and below the cutting edge to be excavated with the same bit, simplifying the overall structure and reducing the cost of the machine. The purpose of the present invention is to provide an excavation machine that can reduce the occurrence of trouble.

That is, in the present invention, a first support arm is pivoted near the tip of a vertical rotation shaft in a direction perpendicular to the rotation shaft and cannot be moved vertically, and a transmission shaft is attached to the end of the first support arm. The second support arm is parallel to the rotating shaft and is pivotally connected so as not to be vertically movable, and one end portion of the second support arm is perpendicular to the transmission shaft and is pivotally coupled to the transmission shaft so as not to be vertically movable. A bit shaft, with a bit attached to the lower end, is pivoted to the other end of the arm, parallel to the rotating shaft and immovable up and down, and between the rotating shaft and the transmission shaft, and between the transmission shaft and the bit shaft. A hole drilling machine characterized in that the two are connected by a rotation transmission member that transmits rotation in the same direction.

An embodiment shown in the drawings will be described below.

As shown in FIGS. 1 to 4, 1 is a hole excavated by an excavating machine according to the present invention, into which a cylindrical well 2 is sunk. The drilling machine includes a drill pipe 3 arranged vertically in a well 2, and this drill pipe 3 is rotated by, for example, a rotary table of a reverse circulation type drilling machine (not shown) installed on the ground surface, and is movable up and down 11. Also, muddy water accompanied by drilling debris is circulated inside the drill pipe 3. A center bit 4 is attached to the lower end of the drill pipe 3, and above it a first support arm 5 is oriented perpendicularly to the drill pipe 3 and is pivoted at the middle portion thereof so as not to be movable up and down. A transmission shaft 6 is provided at both ends of the first support arm 5,
7 is parallel to the drill pipe 3 and is pivoted so as not to be able to move up and down, and one end of the second support arm 8, 9 is oriented at right angles to the transmission shaft 6.7. The second support arm 8.9 is pivoted so as not to be able to move up and down, so that the second support arm 8.9 can be bent relative to the first support arm 5 on a horizontal plane. A bit shaft t is attached to the other end of the second support arms 8 and 9.
o and tt are parallel to the drill nozzle 3 and are pivotally connected so that they cannot move up and down, and outer ring bits 12 and 13 are attached to the lower ends of the bit shafts 10 and 11. As shown in FIG. 5, the outer ring bit 12 and 13 are inclined so that the cutting blade 23 cuts the ground laterally in steps.

between the outer sprocket (or gear) 14 fixed to one bit shaft 10 and the upper sprocket (of the pair of intermediate sprockets 15, 16) fixed to one transmission shaft 6; Fixed outer sprocket 1
7 and the lower sprocket 19 of a pair of intermediate sprockets 18 and 19 fixed to the other transmission shaft 7, and between the lower sprocket H6 of one transmission shaft 6 and the drill pipe 3.
Chains are connected between the lower sprocket 21 of the pair of center sprockets 20 and 21 fixed to 22 is wound, and the rotation in the same direction as the drill pipe 3 is transmitted to the transmission shaft 6,
7 to the pit axis 10.11.

In the drilling machine as described above, the distance between the drill pipe 3 and the transmission shaft 6 (or 7), the transmission shaft 6 (or 7)
The sum of the distance between the cutter shaft 10 (or 11) and the radius of the outer cutter 12 (t or 13) is equal to the outer diameter of the well 2, and therefore the drilling machine is inserted into the well 2. In this state, the second support arm 8.9 is bent relative to the first support arm 5, as shown in the first and second figures.

Next, the operation of the above embodiment will be explained.

The well 2 is held by a suspension device (not shown) so as not to scuttle during excavation. When excavating at the beginning of excavation or when soil has entered the well, the excavating machine is the first
, 2, the second support arms 8 and 9 are bent relative to the first support arm 5, and the outer ring bits 12 and 13 come into contact with the inner wall of the well. When the drill pipe 3 rotates while being given a downward thrust, the center bit 4 rotates and excavates the center of the bottom of the hole 1. On the other hand, the 30 rotations of the drill pipe are transmitted to the bit shaft 10°11 via rotation transmitting members such as the sprockets 14 to 21 and the chain 22, and thereby the outer ring bit at the lower end]
, 2, and l3 rotate and excavate the outside of the bottom of hole 1. As described above, the outer ring bit 12.13 is given the rotation (rotation) torque of the drill pipe 3 and the thrust via the first and second support arms 5, 8.9, so the outer ring bit 12. 13, a revolving torque is generated, and the outer ring pit 12
．． 13 revolves around the drill pipe 3 in the same direction as the rotation direction of the drill pipe 3 while rotating, and excavates around the center bit 4 while slidingly contacting the inner wall surface of the well 2. At this time, an outward expanding force acts on the outer ring bits 12 and 13, but since they are restricted by the well 2, they revolve while slidingly contacting the inner wall surface thereof. Furthermore, since the outer ring bit 12 and 13 have a structure in which the cutting blade 23 is inclined and cuts the ground laterally in a step-like manner, the phenomenon that the outer ring bit 12 and 13 only rotate and do not revolve occurs does not occur.

When the ground inside the well 2 is excavated as described above, and the outer ring pit) 12.13 reaches the cutting edge of the well 2, the outer ring pit) 12 and 13 are used to control the well 2 as shown in Figures 3 and 4. is released and expands outward. The outer rings 12 and 13 continue to revolve even in this state, thereby excavating the ground below the cutting edge of the well 2. After drilling to a predetermined size, the drill and R-build 3 are reversed while applying a slight thrust, thereby causing the outer ring to snap)12.
L3't--Reverse the operation to return to the state shown in the 1st and 2nd figures, pull up the excavation machine, and sink the well 2. Then, a new well is added to the surface of the earth and the above-mentioned excavation is performed again, and this operation is repeated to sink the well.

Here, based on the principle of revolution of the outer ring pit as described above □
This will be explained with reference to FIG. In FIG. 6, R is the radius of the center sprocket 20, and r is the outer sprocket 1.
4 and the radius of the intermediate sprocket 15, 16, P is the tensile force of the chain 22 acting on each sprocket.

When the center sprocket 20 rotates to the left (reverse rotation), the center of the drill pipe 3, that is, the center O of the first support arm, is fixed, so the revolving torque of the first support arm 5 is the force acting on the intermediate sprockets 15 and 16. It is obtained from the sum of moments around the zero point.

In other words, the clockwise moment is M, =P (R'+ r)...
The moment of ・・・・・・・・・(Rimata counterclockwise rotation) is M, =P(R+R')
......(2), so if the clockwise direction in Fig. 6 is positive, the revolution torque To is To = Ml - Ml ......
......It is expressed as (3). However, P-r is the sum of excavation resistance moments. (t+, (2) l (
From formula 33, To=-P (R-r) (0...
(4) Therefore, the first support arm 5
rotates to the left, and the outer ring bit 12 revolves to the left.

Also, at that time, the outer sprocket 14 and the intermediate sprocket)
15 and 16 have the same diameter, no revolution torque is generated in the second support arm 8 between them, and the outer ring pit 12 moves in the direction approaching the center O of the drill pipe 3, that is, in the closing direction.

Contrary to the above, the center sprocket 20 rotates clockwise (normal rotation)
In this case, the outer ring 12 revolves in the right direction and simultaneously moves away from the center O of the drill pipe 3, that is, in the direction of expansion, and excavates below the cutting edge of the well while colliding with the drilling resistance. Note that the second support arm 5 is
7 in which the support arm 8 is oriented in one direction (rightward in FIG. 6).
) By making the outer ring pit 12 bendable, a phenomenon in which the outer ring pit 12 expands to the maximum extent and then moves in the closing direction does not occur.

In the above explanation, the outer sprocket 14 and the intermediate sprocket 15.16 were made to have the same diameter, but in this case, the diameter of the outer sprocket 14 is larger than the diameter of the intermediate sprocket 15.16. If the diameter of the outer sprocket 14 is smaller than the diameter of the intermediate sprockets 15 and 16, the opening and closing of the outer ring bit 12 will not be smooth due to drive transmission resistance. Transmission of rotation is not limited to the combination of sprockets and chains, but may also be achieved by meshing gears or using a combination of them. For example, rotation is transmitted between the drill nosop 3 and the transmission shaft 7 by meshing gears, and the transmission shaft It will be more effective if the rotation is transmitted between 7 and the bit shaft 11 by a combination of a sprocket and a chain.

In the above embodiment, two outer ring bits are provided, but one or three or more may be provided, and the center bit may not necessarily be provided, in which case the outer ring pit may have a large diameter.

The hole drilling machine of the present invention is applicable not only to the construction of sinking wells, but also to drilling holes for enlarged piles with enlarged lower ends.

Since this invention is constructed as described above, the bit attached to the bit shaft rotated in the same direction by the rotary shaft rotates on its own axis and revolves around the rotary shaft during excavation, and the bit rotates in the same direction as the rotary shaft. When it reaches the cutting edge, it expands, so the same pit can be used to excavate the ground inside the well and below the cutting edge, eliminating the need for a conventional expansion bit that mainly excavates the ground below the cutting edge. The overall structure is simplified and the cost of the machine can be reduced.
The occurrence of trouble can also be reduced. In addition, since the method uses a small-diameter bit to drill a large-diameter hole, the thrust and drilling horsepower are small, reducing construction costs.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention; FIG. 1 is a longitudinal cross-sectional view showing the state of excavation of the ground inside the well, FIG. 2 is a cross-sectional view of the same, and FIG. 3 is a diagram showing the ground below the cutting edge of the well FIG. 4 is a longitudinal cross-sectional view showing the state of excavation, FIG. 4 is a cross-sectional view of the same as above, FIG. 5 is a side view showing the cutting blade of the pit, and FIG. 6 is an explanatory diagram of the principle of revolution of the outer ring bit. 1...Hole 2...Izutsu 3...Drill nozzle 4...Center pit 5...
・First support arm 6.7...Transmission shaft 8.9...Second support arm 10.11...Cutter shaft 12.13...
・Outer ring bit 14-21...Sprocket 22...
・Chain 23...Cutting blade patent applicant Tokyo Seisakusho Co., Ltd. 1 Figure 2 Figure 3 Figure Atsushi 4 Figure 'pf55 Procedural amendment 6゜Showa 6θ August 3Q (■, Indication of the incident
7゜3. Relationship with the case of the person making the amendment Patent applicant: 4-12-9 Hokuei, Urayasu City, Chiba Prefecture, Tokyo Seisakusho Co., Ltd. Representative: Inouehebu 4, Agent: 4-5 Kojimachi, Chiyoda-ku, Tokyo (Address: 102) Contents of amendment 1) The entire specification shall be amended as attached. 2) Amend Figure 2.4.6 of the drawings as attached. List of attached documents 1M 2:
1 Drawing surface (Fig. 2.4.6) 1 Specification ■6 Name of the invention Hole drilling machine 2, Claim 1, A first support arm is placed near the tip of a rotating shaft at right angles to the rotating shaft. oriented and pivoted so as to be immovable in the axial direction,
A transmission shaft is pivoted to the end of the first support arm so as to be parallel to the rotating shaft and cannot be moved in the axial direction, and one end of the second support arm is connected to the transmission shaft in a direction perpendicular to the transmission shaft. a bit shaft having a bit attached to the lower end thereof is pivoted to the other end of the second support arm so as to be immovable in the axial direction and parallel to the rotating shaft; A drilling machine characterized in that the rotation shaft and the transmission shaft and the transmission shaft and the bit shaft are connected by a rotation transmission member. 2. The hole drilling machine according to claim 1, wherein a bit is attached to the tip of the rotating shaft. 3. The hole drilling machine according to any one of claims 1 to 2, wherein the rotating shaft is a drill pipe through which muddy water circulates. 3. Detailed Description of the Invention The present invention relates to a hole drilling machine, and is particularly effective for press-fitting cylindrical bodies such as wells, caissons, and shields into the ground. Generally, in the well sinking method, the well is suspended and supported, and after excavating the ground at the bottom with an excavator inserted inside the well, the well is sunk into the ground. In order to sink a well, it is usually necessary to excavate not only the inside of the well, but also the ground below the cutting edge of the well. A dedicated expansion bit is provided to excavate the ground below the cutting edge, which increases the number of bits, making the whole machine bulky, and the expansion mechanism of the expansion bit becomes complicated, which only increases the cost of the machine. However, there was a drawback that troubles were likely to occur. This invention eliminates the drawbacks of the conventional ones as described above, and allows the excavation radius to be varied even during excavation, making it possible to excavate, for example, the ground inside the well and below the cutting edge with the same bit, and the overall structure is simple. It is an object of the present invention to provide an excavating machine that is inexpensive and can reduce the occurrence of trouble. That is, in the present invention, a first support arm is pivotally mounted near the tip of a rotating shaft in a direction perpendicular to the rotating shaft and cannot be moved in the axial direction, and a transmission shaft is attached to the end of the first supporting arm. The second support arm is parallel to the rotation axis and is pivoted so as not to move in the axial direction, and one end of the second support arm is pivoted to the transmission shaft in a direction perpendicular to the transmission shaft and cannot be moved in the axial direction. Second
A bit shaft with a bit attached to the lower end is pivoted to the other end of the support arm so as to be parallel to the rotating shaft and immovable in the axial direction, and between the rotating shaft and the transmission shaft and the transmission shaft. and a bit shaft are connected by a rotation transmission member. An embodiment shown in the drawings will be described below. As shown in FIGS. 1 to 4, reference numeral 1 denotes a hole excavated by the excavating machine according to the present invention, and in the case of a well sinking construction, a cylindrical well 2 is sunk into this hole 1. The drilling machine includes a drill pipe 3 arranged vertically in a well 2, and this drill pipe 3 is rotated by, for example, a rotary table of a reverse circulation type drilling machine (not shown) installed on the ground surface, and can also be moved up and down. In addition, muddy water accompanied by drilling debris is circulated inside the drill pipe 3. A center bit 4 is attached to the lower end of the drill pipe 3, and a first support arm 5 is attached above the center bit 4.
is oriented perpendicularly to the drill pipe 3 and is pivotally connected at the intermediate portion so as not to be vertically movable. Transmission shafts 6 and 7 are parallel to the drill pipe 3 and are pivotally connected to both ends of the first support arm 5 so as not to be vertically movable.
One end of the support arm 8.9 is perpendicular to the transmission shafts 6, 7 and is pivotally connected to the transmission shaft 6, 7 so as not to be movable up and down. It is bendable. A bit shaft 10.11 is parallel to the drill pipe 3 and pivoted to the other ends of the second support arms 8, 9 so as not to be able to move up and down.
Outer ring bits 12 and 13 are attached to the lower end of 1. As shown in FIG. 5, this outer ring bit 12, 13 has a cutting blade 23 attached to its outer periphery that is inclined so as to cut the ground laterally in a stepped manner. An outer sprocket 14 fixed to one bit shaft 10 and a pair of intermediate sprockets 15 fixed to one transmission shaft 6.
between the outer sprocket 17 fixed to the other bit shaft 11 and the lower sprocket 19 of the pair of intermediate sprockets 18 and 19 fixed to the other transmission shaft 7; Between the lower sprocket 16 of one transmission shaft 6 and the lower sprocket 21 of the pair of center sprockets 20 and 21 fixed to the drill pipe 3, and between the upper sprocket 18 of the other transmission shaft 7 and the drill pipe. Sprocket 2 above 3
A chain 22 is wound between each bit shaft to and tt, so that rotation in the same direction as the drill pipe 3 is transmitted to the bit shafts to and tt via transmission shafts 6 and 7. Rotation transmission is not limited to the combination of sprockets and chains, but may also be performed by meshing gears. Next, the operation of the above embodiment will be explained. The well 2 is held by a suspension device (not shown) so as not to scuttle during excavation. When excavating at the beginning of excavation or when soil has entered the well, the excavating machine is the first
, 2, the second support arms 8 and 9 are bent relatively greatly with respect to the first support arm 5, and the outer ring bit 12
゜13 is in contact with the inner wall of the well. When the drill pipe 3 rotates while being given a downward thrust, the center bit 4 rotates and excavates the center of the bottom of the hole 1. On the other hand, the rotation of the drill pipe 3 is transmitted to the focus shaft 10°11 via the transmission shafts 6 and 7 through rotation transmitting members such as the sprockets 14 to 21 and the chain 22, thereby causing the outer ring bit 12°13 at the lower end to rotate. and drill outside the bottom above the hole. As described above, the outer ring bits 12 and 13 receive rotation (rotation) torque from the drill pipe 3 and the first. Since a thrust force is applied via the second support arm 5, 8.9, a revolving torque due to digging resistance is generated in the outer ring bit 12.13.
The outer ring bits 12 and 13 revolve around the drill pipe 3 in the same direction as the rotational direction of the drill pipe while rotating, and excavate around the center bit 4 while slidingly contacting the inner wall surface of the well 2. At this time, outer ring bit 12.1
Although an outward expansion force acts on Izutsu 3, since it is restricted by Izutsu 2, it revolves while sliding against the inner wall surface of Izutsu 2. As described above, when the ground inside the well 2 is excavated and the outer ring bit 1.2.13 reaches the cutting edge of the well 2, the outer shaft bit 12.13 is inserted into the well 2 as shown in Figure 3.4. The six external shaft bits 12 and 13, which expand outward as the restriction is lifted, continue to revolve even in this state, thereby excavating the ground below the cutting edge of the well 2. After drilling to a predetermined size, the drill pipe 3 is reversed while applying a slight thrust to the outer ring bit 12.
13 is reversed to return to the state shown in Figure 1.2, the excavation machine is pulled up, and the well 2 is sunk. Then, a new well is added to the surface of the earth and the above-mentioned excavation is performed again, and this operation is repeated to sink the well. Note that the second support arm 8.9 is different from the first support arm 5.
By allowing the outer shaft bits 12 and 13 to be bent only in one direction (to the left in FIGS. 2 and 4) (for example, by providing a stopper at the pivot joint of the second support arms 8 and 9), the maximum expansion of the outer shaft bits 12 and 13 is achieved. You can set limits. Next, the principle of revolution of the outer ring bit will be explained based on FIG. The following explanation deals with the case where rotation is transmitted by meshing gears, but similar results can be obtained with a combination of sprockets and chains. In the figure, re, rlP and R2 are gears A, respectively. These are the radii of B and C, and Ro is the center of the drill pipe 3. and the center 02 of the bit shaft 10, R1 is the length of the first support arm 5 between Oo and the center ○ of the transmission shaft 6, and R2 is the length of the second support arm 8. Outer circumference C' of the outer ring bit 12 at an angle φ from the second support arm 8
Focusing on the cutting edge at the point, let its digging resistance be f′,
As a result, when it is assumed that excavation resistance f acts on point C on gear C, a resultant force P2 is generated at the center 02 of the bit shaft 10 in a direction that bisects the angle φ. If this is found from the balance of the moment around point C, (R2-r2Cogφ)・f=r2sinφ/2・P,
- Because (1). is obtained. In this case, the support arm 8 is at point 02 in the opening direction, P, si
Receives a force of n φ/2. If this is P2X, then (2
) From the formula, PBX = (1-cosφ) ・f
−(3). The center of the drill pipe 3 at this time is 0
The revolving moment M2 around ° is M, = R2・sin (φ/2+γ)・round
...(4) Here, in Fig. 4, Rosinβ=R, sinθ −(5)
R, cosβ=R, +R, cosθ ・(6
), so from equations (5) and (6), equation (4) becomes M2= (1-cosφ) f (R, +R1 cos
It can be expressed as θ') - (7). On the other hand, the excavation power is transmitted from gear A to gear C via points a and b.
Therefore, the center o0 of the transmission shaft 6 has an angle a, OL
, b is generated in the direction that bisects it. This is b
If we find it from the balance around the point, we get . The component Pi in the direction perpendicular to the R of Pl is P,, x
=p1 cos α= (1+ cos θ)−f
-(10), therefore, the moment M□ around which Pl acts on the 0□ point is M+, = -(1+ cosθ) -j -R1-,
(1, 1). Therefore, ○ of the entire system due to the excavation resistance f'. The moment around a point is expressed by the following equation. M=M
θ) ・cosφ - (12) When this is integrated over the entire circumference of gear C, the total revolution moment, that is, revolution torque T is = 2πf (R1 - R1) = 2tc f (ro p, )
−(13). This means that when the distribution of excavation resistance is equal, the direction of revolution is the length R of the support arm.
1, R2 or gear radius r. , differs depending on the rl
r. >r2 means right revolution in FIG. 6, and ro<rz means left revolution. The above case is a case where the distribution of excavation resistance is equal. For example, when a part of the outer ring bit 12 is overlapped on the center bit 4 as shown in FIGS. 2 and 4, the outer ring bit 12
The distribution of the excavation resistance acting on the surface becomes uneven, and under these conditions r. ;P, but revolution can occur. Rotation may be transmitted by a combination of gear meshing, sprockets, and chains; for example, drill pipe 3
It is more effective if the rotation is transmitted between the transmission shafts 6, 7 and the bit shaft 10.11 by gear meshing, and the rotation is transmitted between the transmission shafts 6, 7 and the bit shaft 10.11 by a combination of a sprocket and a chain. become. In the above embodiment, two outer ring bits are provided, but one or three or more may be provided, and a center focus may not necessarily be provided, in which case the outer ring bit may have a large diameter. The hole drilling machine of the present invention is applicable not only to the construction of sinking wells, but also to drilling holes for enlarged piles with enlarged lower ends. Since this invention is configured as described above, the bit attached to the bit shaft rotated by the rotary shaft rotates on its own axis and revolves around the rotary shaft during excavation, and the bit expands to increase the digging radius. is variable, and therefore the same bit can be used to excavate the ground inside the well and below the cutting edge, for example, in well drilling, eliminating the need for a conventional expansion bit that excavates the ground below the cutting edge, and improving the overall structure. It is simplified, the cost of the machine can be lowered, and the occurrence of trouble can be reduced. In addition, since the method uses a small-diameter bit to drill a large-diameter hole, the thrust and drilling horsepower are small, and construction costs can be reduced. 4. Brief description of the drawings The drawings show one embodiment of the present invention. Fig. 1 is a vertical cross-sectional view showing the state of excavation of the ground inside the well, Fig. 2 is a cross-sectional view of the same as above, and Fig. 3 is a cross-sectional view of the same. Fig. 4 is a cross-sectional view of the same as above, Fig. 5 is a side view showing the cutting edge of the bit, and Fig. 6 is an explanatory diagram of the principle of revolution of the outer ring bit. .

Claims (1)

[Scope of Claims] 1. A first support arm is pivotally mounted near the tip of a vertically oriented rotating shaft so as to be perpendicular to the rotating shaft and cannot move vertically;
A transmission shaft is pivoted to the end of the first support arm so as to be parallel to the rotating shaft and cannot move up and down, and one end of the second support arm is connected to the transmission shaft in a direction perpendicular to the transmission shaft. A bit shaft having a bit attached to the lower end is pivoted to the other end of the second support arm so as not to be movable up and down, and is parallel to the rotation shaft and not movable up and down. A hole drilling machine characterized in that the transmission shaft and the bit shaft are connected by a rotation transmission member that transmits rotation in the same direction. 2. The excavating machine according to claim 1, wherein a bit is attached to the tip of the rotating shaft. 3. The excavating machine according to claim 1 or 2, wherein the rotating shaft is a drill pipe through which muddy water circulates.