JPS60126489A - Boring machine - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] The present invention relates to the creation of a boring machine that enables accurate poling to reach a sufficient depth using a relatively compact mechanism, and achieves efficient construction that is responsive to each poling situation. It was designed to tighten it.

With the recent development and spread of civil engineering work, many improvements have been made to boring machines, but with conventional boring machines, as the drilling depth increases, a correspondingly huge boring machine is required. Of course, regarding the drive mechanism for drilling holes, it is necessary to increase the output since the long drilling rod uses its own weight to drill and rotate the drilling rod. The required output for drilling a hole differs depending on the soil quality at the construction site, and also changes depending on the depth of the hole being drilled.The output of the drive mechanism described above and L2 are related to the soil resistance. It is necessary to design the machine based on the premise that the drilling depth will be the maximum in the maximum condition, which inevitably results in a hugely expensive machine.

Note that the purpose of poling construction as described above cannot usually be achieved by simply drilling holes; instead, piles are inserted into the hole that has been formed, and reinforcing steel, concrete IJ, etc. Further construction is indispensable for foundation work, etc., but conventional boring machines are generally used only for drilling, and after drilling as described above, subsequent construction during the drilling is necessary. In order to save money, it is necessary to bring in another crane and other equipment to carry out the construction, and the need for additional equipment in this way not only increases the required machinery cost but also makes it difficult to carry out the construction work. Even on site, after a hole is drilled, the boring machine must be completely moved and another machine brought in, and the drilling machine must be accurately aligned with the hole drilled before subsequent construction work can be carried out. Therefore, these work processes are disadvantageous in that they require considerable complexity and waste of time.

The present invention has been devised after repeated studies in view of the above-mentioned circumstances, and the specific embodiments thereof are shown in the attached drawings. First, the general outline of the boring machine according to the present invention will be explained. The structural relationship consists of a main body part A, a mass part B, a rotary head part C, and a Kelly rod part, and a swinging part E'z is appropriately employed for these parts. That is, the main body part A is provided with an upper frame 23 on the backhoe uniform flora 1 via the turning mechanism part 2, and the upper frame 2
3 is provided with a drive mechanism section 24 and a driver's cab 25, and a main arm 6 is attached to the side of the driver's cab 25 by a pivot portion 6a. A member 4 is provided. The mast section B is mainly composed of a mast 3 whose base end is attached to the front of the crawler 1, and a connecting link 61 is provided between a pivot section 60 provided below the middle of the mast 3 and the main arm 6 described above. A winch-like hoisting mechanism 7a, 7b is attached to the upper part of the mounting seat 40 and the main arm 6, respectively, and further lifts and lowers the rotary head part C downward from the upper end side of the mast 3. A hydraulic cylinder 33 for operation is provided, and an arm 30 bent forward at the upper end of the mast 3
A pulley 31 is disposed on the arm 30, and the wires drawn out from the hoisting mechanisms 7a and 7b are connected to a Kelly Ron door or the like via the pulley 31. The lower head part C is a triangular bracket 3
4 and a rotary head 8 attached to the apex side of the bracket 34, the bottom side of the bracket 34 engages with the mast 3 to guide its lifting and lowering operations, and its upper end is connected to the hydraulic cylinder 33. ing. The Kelly rod 7 to which the rotary head 8 is attached forms the main body of the Kelly rod portion mentioned above, and a hanging portion 70 for the wire from the hoisting mechanism 7a is provided at the upper end of the Kelly rod portion. The wire from the other hoisting mechanism 7b assists the work by the Kelly rod γ by appropriately suspending the pile members and other members and equipment necessary for construction.

In the configuration as described above, Kelly rod 7
This structural relationship is a main feature of the present invention, that is, as shown in FIG. Furthermore, a plurality of lock pockets 72 having a width approximately half the rail width are arranged at appropriate intervals in the drive rail 71 over a length range slightly larger than the length of the rotary head 8. ing. As shown in FIG. 3, this Kelly rod 7 is made up of a plurality of hollow rod members 7', 7", 7" having different diameters, and these rod members 7', 7", 7 II/
is hollow and inserted telescopically, and the base end of the smallest diameter rod body 7 is equipped with a swivel 73 for untwisting the wire (for example, a bearing is installed between the upper and lower bodies). The wire from the hoisting mechanism 7a as described above is connected via an internal intermediate body (1) in which the upper and lower bodies are mutually rotatable, and a digging tool is attached to the tip thereof. 79 is attached, and can be condensed as shown in FIG. 3a, or expanded as shown in the same figure. Furthermore, each rod body 7', T", as described above,
A groove 74 is vertically provided on the inner surface of the rod body 7', 7'' which should be located on the outside in order to engage and drive the rod parts 7' and 7' mutually, as shown in Fig. 4. A drive rail 71a, which is provided with a lock pocket 72 similarly to the drive rail 71, is provided protruding from the outer surface of the rod body 7'', 7〃.

As shown in FIG. 4, the lower ends of the rod bodies 7' and 7'', which should be located on the outside as described above, have a diameter approximately equal to the outer diameter of the inner rod body fitted therein on their inner surfaces. A ring portion 75 having an inner diameter is attached, and the upper end of the rod member 7'', 7, which should be located inside, has an outer diameter approximately equal to the inner diameter of the outer rod member to be fitted thereon. A ring portion 76 is formed, and each rod portion body 7'
, 7" 7 // 1 is fully extended, these ring parts 75 and 76 are engaged so that the inserted inner rod part body 7 # or 7 // cannot be pulled out. A ring portion 77 having an outer diameter larger than the inner diameter of the rod member 7' is attached to the lower end of the rod member γII/ which should be located at the lowest end in this extended state. Define the condensation position of

The details of the structure of the rotary head 8 are as shown in FIG.
0.80 motor shaft 89 engages with the engagement gear 81 of the rotating shaft 82 provided parallel to the motor shaft 89, and the rotating shaft 8
An intermediate gear 83 is engaged with the small gear portion 82b of No. 2, and a large gear 84 attached to a hollow output shaft 85 is engaged with the intermediate gear 83, thereby transmitting rotational force to the output shaft 85. Kelly rod sliding parts 86 and 86 are attached to the upper and lower parts of the hollow output shaft 85, respectively, and these Kelly rod sliding parts 86 and the hollow output shaft 85 are inserted through the hollow output shaft 85 as described above. A Kelly rod γ is provided. The above-described Kelly rod sliding portion 86 is also engaged with the above-described drive rail 71 of the Kelly rod 7, as shown in FIG. 8.9 for the lower Kelly rod sliding portion 86. A plurality of sets of retaining grooves 86a are vertically arranged, and these retaining grooves 86
The drive rails 71, 71 are engaged with one of the opposing pairs of rails B. That is, the engagement groove 86a
It is clear that the rotational torque due to the clockwise rotation of the output shaft 85 is transmitted to the Kelly rod I in any case because the drive rail 71 is engaged with the trap, and the Kelly rod 7 is also engaged with the drive rail 71. It is clear that the fitting groove 86a engages and guides the slide in the axial direction as appropriate, but furthermore, either the Kelly rod I assembled in this way or the rotary head 8 (its output shaft 85) By sliding one or both of them in the axial direction, each sliding portion 86 is attached to the lock pocket (72).
The engagement groove 95a portion of the groove 95a automatically engages and its axial sliding is locked, and in such a locked state between the Kelly rod 7 and the rotary head 8, the axial push by the hydraulic cylinder 33 described above Force can be transmitted, and an excavating force that is a combination of the gravity of the Kelly rod 7 itself and the pushing force of the hydraulic cylinder 33 can be applied to the portion of the excavating tool 100 attached to the lower end of the Kelly rod 7. The locked state can be easily released from the lock pocket 72 by a slight rotation of the output shaft 85 in the opposite direction, and the Kelly rod 7 is again connected to the hydraulic cylinder 33.
It can slide regardless of the Incidentally, a casing pipe 101 is appropriately attached to the Kelly rod 7 together with the drilling tool 100, and the hole is similarly pushed in by the pushing force of the hydraulic cylinder 33 and the rotational force of the rotary head 8. The inside of the pipe 101 is drilled and discharged.

The above-mentioned swing part E is attached to the front of the crawler 1 and holds the casing vibrator 101 as described above, and when the above-mentioned drilling becomes difficult due to the resistance of earth and sand, it can be When pulling out, by adding rocking, the frictional resistance force on the surface of the casing pipe 1010 is reduced, making it easier to push in or pull out as described above.

In the rotary head 8, it is of course necessary to lubricate the interlocking system using the above-mentioned spur gears and the bearing parts, and as a forced lubrication mechanism for this purpose, a shaft hole 82a (11) is provided in the rotating shaft 82. A spiral shaft 87 is formed in the shaft hole 82a.
is inserted, and the lower end of the spiral shaft 87 is located in an oil reservoir 88 formed at the lower end of the rotating shaft 82. The lubricating oil is sent upward through the spiral shaft 87, that is, it acts as a screw type pump to forcibly transfer the lubricating oil and supply the lubricating oil to each part.

Regarding the drive using the plurality of hydraulic motors 80, 80 as described above, one characteristic operating relationship according to the present invention is formed, that is, a piping system as shown in FIG. 10 is adopted for this relationship. There is. In other words, for those hydraulic motors 80 and 80, the switching unit 1 is connected to the hydraulic power source 180.
Distribute valve 183 containing 81 and 182
The hydraulic motors 80 and 80 are operated in series or parallel by switching the pulp 183, and the switching section 182 is located between the pipes 184 and 185 (12). In this state, pressure oil from the hydraulic source 180 drives one motor 80 and then the switching unit 18
2 to conduit 185 to drive the other motor 80 and then return to tank 186. On the other hand, when the other switching section 181 is located at the pipe line 184 and 185, the pressure oil flowing through the pipe line 184 from one motor 80 is returned to the pipe line 186 via the pipe line 187. Moreover, the pressure oil from the pipe 188 returns to the tank 186 after driving the other motor 80 via the pipe 185. That is, when the switching section 181 is switched to the switching section 181 in this way, the hydraulic motors 80 and 80 are driven in parallel, and when the switching section 182 is switched to the pipe lines 184 and 185 as shown in the figure, each motor is driven in series. It is a matter of fact,
In the case of parallel drive, the torque is doubled, and in the case of series drive, rotation speed is doubled. In other words, the drive force for the Kelly rod γ via the output shaft 85 in the rotary head 8 can be adjusted based on either torque or speed in response to the work conditions such as the soil layer to be excavated or the depth of the excavation work. It is designed so that it can be switched as if it had been changed.

Kelly rod sliding part 8 at the bottom of the rotary head 8
Cardan joint 172 on the 6th part
The rotary cylinder 17 is connected via f. That is, regarding this Cardan universal joint 172, as shown in FIG.
In this way, the buffer body 170 protects against stress or shock caused by mistakes in mechanical operation, opening during drilling, opening and closing of the bottom cover of the packet 12, or winding up of the Kelly rod 7. Buffer. The above-mentioned casing pipe 101 is engaged with a retaining part 173 formed at the lower end of the rotary cylinder 17 by its engaging part 101B in the relationship shown in FIG. 11, and the bolts are inserted into the bolt holes 174 and 101b. The rotational force from the rotary head 8 is easily inserted and connected,
Effectively transmits pushing and pulling forces.

Specifically, the cylinder part 4 provided on the base end side of the mast 3 is a cylindrical part 43.4 as shown in FIG.
4 are slidably engaged, the proximal end of one cylindrical body 43 is pivotally connected to the main arm 6 by a pin 45, and the cylindrical body 43 is attached to the end side of the other cylindrical body 44. A horizontal cylinder 41 in the direction crossing the .44 is installed, and a rod 46 with a piston/4γ provided in the middle is inserted into the horizontal cylinder 41 to form a double-barrel type, and the rod 46
Both sides of the mast 3 are pivotally attached to both ends of the mast.

A vertical cylinder 42 is provided at the axial center of the above-mentioned cylindrical body 43, 44, and the piston rod 48 of the vertical cylinder 42 is fixed at a position corresponding to the intermediate part of the above-mentioned horizontal cylinder 41. ing.

That is, to explain the operation of such a cylinder part 4, by applying hydraulic pressure to one side of the piston/47 (15) in the horizontal cylinder 41, the mast 3 is moved to the other side in response to the sliding lid of the piston 47. By applying hydraulic pressure to the other side of the piston 47, the mast 3 is moved in one direction. In addition, the vertical cylinder 42 has oil filling holes 49 and 49a formed at its upper and lower ends, respectively, and by injecting pressure oil into the oil filling hole 49, the mast 3 tilts backward, and conversely, pressure is applied to the pouring hole 49a. By supplying oil, the mast 3 is tilted forward. In other words, as described above, the mast 3 can be tilted appropriately in the left-right direction and the front-back direction, allowing a wide range of work for hoisting and unwinding with the winch, and without removing the rotary head 8. Reinforcing bars and the like can be inserted or pulled into the hole without using any other work crane.

The above-described main arm cylinder 63 bears a large load to hold the mast 3, and in order to ensure that the mast 3 once assembled operates properly (16), it is divided into two parts as shown in Fig. 13. color 3
6, the piston front 4 is fixed in the axial direction of the clamping cylinder 63 from both sides thereof in a state of protruding to a predetermined length. That is, thus color 36.
The piston rod 64 clamped and fixed by the piston rod 36 is stable even under conditions where a large load is applied to the mast 3 by each of the hoisting mechanisms 7a and 7b, and prevents overturning and breakage even when the load exceeds the limit load. .

Regarding the above-mentioned swinging part E, specifically, from FIG. 14 to FIG.
It is preferable to adopt a configuration as shown in FIG. That is, a shaft support 130 is attached to mounting portions 131 and 131 that project toward the crawler 1, and a base body 138 projects from the shaft support 130 toward the front lower part. The base body 138
As shown in FIG. 14, mounting portions 142 and 142 are provided oppositely in front of both sides of the holder 130, and swing cylinders 134. Chuck member bodies 137 pivotally attached to the ends of the rods 134 are supported, and a chuck cylinder 136 is provided between the ends of the chuck members 137 and 137, as shown in FIG. 15.

The above-mentioned swing cylinder 134 has its base end pivotally connected to the rotating shaft 133 in the pivot seat 130, and a center rod 143 is connected to the base body 13 at the pivot point.
A retaining ring 144 is attached to the tip of the center rod 143 so as to be positioned at a predetermined height with a supporting part 145, and the casing The upper part of the pipe 101 is rotatably held. A push/pull cylinder 135 is provided between the above-mentioned mounting portion 142 and the chuck body 137.
, 137, and a pair of insertion bars 132 are provided on both sides of the middle part of the pace body 138.
are arranged oppositely, and these insertion bars 132 are connected to the 17th
As shown in the figure, by pulling the crawler 1 toward the chassis lateral groove 146 and engaging it, the weight of the entire machine is absorbed by the reaction force when the machine is pushed in as described above. Note that the rotational reaction force accompanying the swinging operation is the same (for the entire machine) by inserting the rond-shaped mounting portion 131 into the engagement hole 147, 147 as shown in FIG. 17 in the chassis 1a of the crawler 1. You can take it on your own. A spherical joint or the like is used at the connecting portion between the swing cylinder 134 and the chuck member 137, so that the two members 134, 137 can freely take any direction relative to each other. Furthermore, a switching member 139 is attached to the inside of the swing cylinder 134 as shown in FIG. As shown in Fig. 16, the middle part of the holder is slidably held by a locking part 140 attached to the swing cylinder 134 (19), and a locking part 141 is provided on the distal end thereof. As shown in enlarged view. In other words, the operating relationship regarding the switching member 139 is to mechanically switch the operating range of the hydraulic swing cylinder 134, and such switching may be electrical, but the illustrated mechanical An example of switching is as follows.

Swing cylinders 13 are installed oppositely on both sides as shown in Fig. 15.
It is clear that when one of the cylinders 4.134 is in the pushing stroke, the other is in the pulling stroke, thereby giving the casing vibrator 101 a rocking action, and each cylinder 134, 134 is designed so that such an operating relationship can be obtained. Also, each cylinder is provided with a switching member 139, and the locking portion 1 is switched in and out by moving the cylinder 134 in and out.
By connecting the engaging portion 141 to the cylinder 40, the excessive pressure oil for each cylinder 134 is switched (20), and the push stroke becomes the pull stroke, and the pull stroke shifts to the push stroke. , thus both cylinders 134, 134 alternately repeat opposite working strokes. Therefore, if the pivot points 14B, 148, and 149 of the chuck body 137, 137, cylinder 134, 134, and base body 138, which make a rocking motion, are in the neutral position as shown in FIG. 14
8. An isosceles triangle is formed between 148 and 149, and the straight line connecting the center of the casing vibe 101 held by the chuck body 137 and 137 and the pivot point 149 is orthogonal to the straight line connecting the pivot points 148 and 148. Therefore, at this time, the distance between the locking portion 140 and the engaging portion 141 is equal for each switching member 139 provided in each cylinder 134, 134. Further, the pushing and pulling operation interval (stroke) of each cylinder 134, 134 is regulated by the interval between the locking part 140 and the engaging part 141 in this state. By the way, when each cylinder 134.134 goes from a horizontal position to an upwardly inclined position as shown in FIG. 14, the distance between pivot points 148 and 149 becomes the first
It is clear that the distance between the locking part 140 and the engaging part 141 becomes longer in this state, as compared to the state shown in FIG. 4, depending on the inclination angle. The stroke is shortened by an amount corresponding to the distance between the pivot points 148 and 149, and if the stroke is shortened in this way, the push/pull stroke will be switched.

The outline of the operation of the device according to the present invention as described above is shown step by step in FIG. 31 and is suspended by a wire, and the rond portion bodies 7' to 7111 are in a sufficiently contracted state. In other words, it is clear that a relatively short or short mast allows the Kelly rod, which can be increased in length as appropriate, to rotate and drill holes. FIG. 6(b) shows a state in which drilling is started, in which the rotary head 8 is operated, for example, to rotate clockwise, and the rotary head 8 and the rod body 7tp are locked, wound, and released from the mechanism 7a. As the wire is fed out, the rod body 7' descends downward, touches the ground, and starts drilling work. 6th
Figure (C) shows a state in the middle of drilling, and by appropriately extending the hydraulic cylinder 3, a downward driving force can be applied to the drilling tool 100 via the bracket 34 to advance the drilling. Note that this hole Vζ can be drilled using the casing pipe 101 if necessary, and the soil removed from the hole thus formed is as shown in FIG. 6(d). Then, while rotating the rotary head 8 in the opposite direction (for example, counterclockwise rotation), the locking state between each of the rod parts 7' to 7 and the rotary head 8 is released, and the wire is wound by the winding mechanism 7a. When raised, the rad member 7 is housed in the outer rod member, and by further retracting the hydraulic cylinder 33, the excavating tool 100 is pulled out to the ground together with the excavated earth and sand, and the earth is discharged. When excavating in this way and increasing the depth, Figure 6 (e
), the rotary head 8 and the outer rod body 7'
and each rod body 7" 711/, the locking lock can be released as appropriate when rotating in the drilling direction, and the lock can be locked at each length state, so the longest length when all the rod bodies are extended is Drilling up to this point can be carried out smoothly.

According to the present invention as described above, a mast section is provided in the machine body, and a Kelly rod is provided which is operated up and down by a hoisting mechanism, and an excavating tool is attached to the Kelly rod and is guided by the mast section. A rotary head that is raised and lowered by a rotary head is provided, and the rotational force for drilling is transmitted to the Kelly rod and the drilling tool by the rotary head. The rotary head is formed of a plurality of hollow rod bodies inserted into the rotary head, and a drive rail is provided vertically on the outer surface of each rod body, and the drive rail and the drive rail are installed on the rotary head and the rod body to be inserted on the outside. Since the fitting groove is formed, the plurality of rod members as described above can expand and contract as appropriate to perform drilling work, and a relatively compact mechanism can accurately perform poling drilling to reach a sufficient depth. It is obvious that this can be done, and in addition, the drive rail is provided with a lock pocket for transmitting an axial operating force, and the mast section is provided with a cylinder for applying an axial force to the rotary head. As a result, depending on the depth of the hole and the soil quality of the construction site, it is possible to perform drilling with the axial pushing force of the cylinder acting in addition to the weight of the excavator and Kelly rod, as described above. Even with such a concise machine, it is possible to realize efficient drilling that corresponds to each work condition, and from all these points of view, it is an invention that has great industrial effects.

[Brief explanation of the drawing]

The drawings show embodiments of the present invention, and FIG. 1 is a side view showing the general structural relationship of a boring machine according to the present invention, and FIG. 2 is a partial side view and plan view of a Kelly rod. Figure 3 is a cross-sectional explanatory view showing the telescopically assembled Kelly rod's expansion and contraction operation, and Figure 4 is a drive rail provided on the outside and a groove formed on the inside. 5 is an explanatory diagram showing the engagement relationship for transmitting axial force, and FIG. 6 is a step-by-step diagram showing the excavation work state of the present invention. 7 is a cross-sectional view showing the specific structural relationship of the rotary head, FIG. 8 is a cross-sectional view of the cardan joint of the Kelly rod sliding part, and FIG. 9 is a plan view thereof. , 1st
Fig. 0 is an explanatory diagram showing the hydraulic piping for a plurality of hydraulic motors provided in the rotary head and their switching operation relationship, Fig. 11 is a side view showing the attachment relation of the casing pipe to the rotary head, and Fig. 12 is A concrete example of a cylinder part is shown in a conceptual sectional view, FIG. 13 is a side view of a collar part with respect to the main arm cylinder, FIG. 14 is a side view of the swinging part, and FIG. 15 is a plan view thereof. FIG. 16 is an enlarged plan view of portion m in FIG. 15, and FIG. 17 is a front view of the machine main body. However, in these drawings, A is the main body part, B is the mast part, C is the rotary head part, DII'i Kelly rod part, E is the swing part, 1 is the crawler, 2-piece rotation mechanism part, 3 is the mast, and 4Fi is the swing part. One part of the cylinder, 6 is the main arm, 6a is its pivot part, 7 is a Kelly rod, 71Ll 7b is a hoisting mechanism, γ/, 7// and 1111 are rod parts, 8 is a rotary head, 23 is an upper part frame, 24 is a drive mechanism, 25
is a driver's cab, 31 is a pulley, 34 is a bracket, 40 and 49 are oil holes, 41 is a horizontal cylinder (27), 42 is a vertical cylinder, 43 and 44 are cylindrical parts, 45 is a bottle, 46 is a rod, 47 is a piston, 4
8 is a piston rod, 60 installation chambers, 61 is a connecting link, 63 is a main arm cylinder such as a hydraulic type, γIU drive 1iNz-le, 72 is a lock box, 73 is a swivel, 74 is a groove, 75 to 77 ring parts , 8° is a hydraulic motor, 81 is an engagement gear, 82 is a rotating shaft, 82a is a shaft hole, 82
bU small gear part, 83 is intermediate gear, 84 is large gear, 85 is hollow output shaft, 86 is Kelly rod sliding part, 86a
87 is the spiral shaft, 88 is the oil sump portion, 8 is the engagement groove.
9 is a motor shaft, 1oo is a drilling tool, 101 is a casing pipe, 13o is a shaft support, 132 is an insertion bar, 133 is a rotating shaft, 134 is a swing cylinder, 135 is a push/pull cylinder, 136 is a chuck cylinder, 131 138 is the chuck part body, 138 is the base part body, 139 is the switching member, 140 is the locking part, 141 is the engaging part, 143 is the center rod, 144 (28) is the retaining ring, 145 is the support part, 146 is the lateral groove, 147 engagement holes, 148 and 149 pivot points, 170 buffer bodies, 1
71 is a flange, 180 is a hydraulic power source, 181.182 is a switching unit, 183 is a destroy valve, 184.
185, 187 and 188 are pipe lines, and 186 is a tank. Patent applicant New Technology Development Co., Ltd. Inventor Karl Heisotz Bauer Hens Barbara (29) Edict P No. 16 En No. 17 Amendment to En procedure (Mr. Oh) Showa 5, etc. 4. Mr. Kazuo Sugi, Commissioner of the Japan Patent Office1, Indication of the case, Showa F2 Patent Application No. 2544 Bay No. 2, Title of the invention 4 parts> Relation to the case 3, Person making the amendment Relationship with the case yiB Applicant Name (Name) Maso Yakuji Closed Co., Ltd. 4, Agent: 1933 Y month, 2 Z day shipping 6, Subject to amendment

Claims (1)

[Claims] A machine main body is provided with a mast section and a kelly rod that is lifted and lowered by a hoisting mechanism, and an excavator is attached to the kelly rod and the excavator is guided by the mast section and lifted and lowered. A rotary head is provided, and the rotational force for drilling is transmitted to the Kelly rod and the drilling tool by the rotary head, and a seven-layer drive rail is vertically installed on the outer surface of the Kelly rod. At the same time, a groove portion for fitting the drive rail is formed in the rotary head sink, and a lock pocket for transmitting the axial operating force is provided in the drive rail, and a lock pocket is provided in the mast portion. A boring machine characterized in that a cylinder is provided for applying an axial force to the rotary head.