JP2013151802A - Multi-spindle excavator and excavating equipment comprising the same, and excavation method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multi-spindle excavator which hardly causes the twisting and curving of an excavated hole while enabling the excavated hole for a diaphragm wall to be efficiently excavated even in a narrow section, and which can perform excavation by replacing a bit edge from a small-bore type to a large-bore type.SOLUTION: A multi-spindle excavator 1 includes: a body portion 20 fixed to a lower end of a rod 10 for being unrotatably supported on the ground; a center bit 53 pivotally supported in a rotatable manner on the body portion 20 and a plurality of side bits 36 and 36; and drive motors 32 and 32 arranged in the body portion 20 so as to be capable of driving the side bits 36 and 36, respectively. The center bit 53 is driven by making rotations of shaft portions 34 of the side bits 36 and 36 transmitted to a shaft portion 51 of the center bit 32 via gear groups (35, 41 and 52).

Description

  The present invention relates to a multi-axis excavator provided with a plurality of drill bits at the tip of a rod, and particularly suitable for constructing a shaft or continuous underground wall (for example, a width of 500 to 700 mm) in a formation in a narrow part. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shaft excavator, a drilling facility including the same, and a drilling method.

  Conventionally, a drill is provided with one or more drill bits at the tip of the rod, and a drive motor is provided on the ground part of the device or in the vicinity of the drill bit, and the rotation torque and load generated by the drive motor are transmitted to the drill bit to excavate the formation. The machine is known. When constructing a shaft or continuous underground wall in the formation with this type of excavator, the excavation hole is filled with a stabilizing liquid and the ground is excavated while protecting the hole wall, and muddy water mixed with earth and sand is added to the stabilizing liquid. In addition to recovering from the borehole, it is necessary to circulate the stable fluid by supplying an amount of stable liquid corresponding to the recovered portion into the borehole.

  As a method for circulating the stabilizing liquid in the excavation hole, a normal circulation method and a reverse circulation method are known. The normal circulation system discharges the stable liquid to the bottom of the drilling hole through the pipe in the rod of the excavator, collects the muddy water overflowing from the drilling hole into the pit, and stabilizes the sediment separated from the mud water In this method, the liquid is supplied again into the borehole. On the other hand, the reverse circulation method collects muddy water from the tip of the drill bit of the excavator through a pipe line in the rod, and supplies the separated muddy water from the collected muddy water as a stable liquid from the surface to the drill hole. It is a method to do. In this manner, the rod of the excavator functions as a conduit for supplying a stable liquid in the normal circulation system and collecting muddy water in the reverse circulation system, in addition to transmitting rotational torque and load to the drill bit.

By the way, for example, the construction of continuous underground walls such as retaining walls and water barriers in the case of undergrounding a railway station building or line or expanding or renovating a station building does not hinder the operation of the railway. Construction machinery must be kept out of contact with the overhead wires supplied. Therefore, it is widely known that the excavator is constructed using a single-axis BH excavator having a small ground portion as compared with a normal excavator.
The excavation method using the BH excavator is performed by rotating a rod connected to a drive motor provided on the ground and using one drill bit attached to the tip of the rod. And it excavates by the said normal circulation system simultaneously with rotation of this one drill bit.

  However, since the excavation method using the single-axis BH excavator is excavation by one bit, the excavation efficiency is low because the number of holes that can be excavated at one time is one. Therefore, there is a problem that the construction period is prolonged at a site where the working time is limited (for example, when construction is performed along the track within a short time from the end of the last train to the passage of the first generator car). In addition, since the BH excavator is smaller than a normal excavator, the rod inner diameter is small and the amount of water fed is small. Therefore, the earth and sand discharged by excavation cannot be sufficiently sent to the above-ground part, and there is a problem that high-concentration muddy water and gravel remain in the hole and become a low-quality pile. Furthermore, since it is small compared with a normal excavator, the rod is thin and the rotational torque is small. For this reason, hole bending is likely to occur, and there are problems such as deterioration in quality as earth retaining and insufficient load as piles.

  On the other hand, as a multi-axis excavator, a rod that is rotated by a ground drive motor, a main driving bit that is coaxially fixed to the tip of the rod, and a plurality of followers that are arranged on both sides of the main driving bit in parallel with the main driving bit. There is a type in which a gear is provided on the shaft portion of the main driving bit and the shaft portion of each driven bit, and the rotation of the rod is transmitted to each bit by meshing these gears with each other.

  In this excavation method using a rod rotation drive type multi-axis excavator, the rod is rotated by a ground drive motor, and the main driving bit and the plurality of driven bits at the tip of the rod are rotated simultaneously to perform excavation. Then, simultaneously with the rotation of the plurality of bits, a plurality of pile holes are opened by the reverse circulation method to construct a continuous underground wall. This multi-axis excavator can excavate efficiently because it uses multi-axis excavation. In addition, since the reverse circulation method is adopted, there is an advantage that the water-stopping property is high and no highly concentrated mud or gravel remains.

JP-A-10-140600 JP 59-185282 A JP-A-62-53675

  However, in the excavation method using the rod rotation drive type multi-axis excavator, when each bit rotates by rotating the rod, a rotational reaction force is generated in a direction opposite to the rotation direction of each bit. For this reason, the central axis in the longitudinal direction of the excavation hole is twisted with the progress of the excavation, thereby causing a problem that the bit cannot be pulled out from the excavation hole and the function as a continuous underground wall is not exhibited.

Therefore, in order to prevent the above-mentioned twist in the rod rotation drive type multi-axis excavator, a method of reducing the twist by providing a stabilizer so as to follow the hole wall along the axial direction of the bit has been proposed. (For example, refer to Patent Document 1).
However, even if a configuration in which a stabilizer is provided in a rod rotation drive type multi-axis excavator is used, the clearance between the stabilizer and the hole wall will increase if the hole diameter partially expands due to the formation conditions. There is a possibility of twisting phenomenon. In addition, since the stabilizer is provided along the bit, the excavator becomes larger by that amount, which is disadvantageous for excavation in a narrow place.

  As another multi-axis excavator, a revolution revolving excavator is known as one that drives a drill bit by providing a power device in the vicinity of a drill bit without providing a power device on the ground (for example, Patent Document 2). The self-revolving excavation apparatus disclosed in Patent Document 2 revolves the bit in the direction opposite to the rotation direction while rotating the bit. With such a configuration, the reaction force received by the bit can be offset by reversing the rotation direction of rotation and revolution, so that the torque balance of the bit can be achieved. There is also a self-revolving excavation apparatus that receives reaction force at the ground part with the same rotation direction of rotation and revolution (see, for example, Patent Document 3).

  However, the excavation method by the self-rotating excavation apparatus disclosed in Patent Document 2 causes the bit to rotate and revolve the bit in the direction opposite to the rotation direction, so that the driving motor provided in the vicinity of the bit occupies a larger range. A bit rotates and excavates a wide range. For this reason, the excavation hole has a large diameter, which is unsuitable for excavation for the purpose of constructing a continuous underground wall in a single pile of about φ600 mm or a narrow part, for example. Here, in general, in the excavation method for circulating the stable liquid, the “small diameter” in the cast-in-place pile method is the excavation diameter up to about φ500 mm to φ800 mm that allows the earth and sand to be transported to the ground by the normal circulation method. Say. In addition, the “large diameter” refers to an excavation diameter of about φ800 mm to φ2000 mm, which is less likely to collapse inside the hole by the reverse circulation method.

  Therefore, the present invention has been made paying attention to such problems, and enables to efficiently excavate a drill hole for constructing a small-diameter standing pile or a continuous underground wall even in a narrow part. In addition, it is possible to provide a multi-axis excavator capable of excavating by exchanging a bit blade edge from a small diameter to a large diameter, and providing a drilling equipment and a drilling method that are less likely to cause twisting and bending of the drilling hole. Objective.

  In order to solve the above-mentioned problems, a multi-axis excavator according to the first aspect of the present invention includes a main body fixed to a lower end of an extendable rod that is non-rotatably supported on the ground, and a central portion of the main body. A central shaft that is pivotally supported only around its own axis and has a center bit attached to its lower end, and is disposed on the side of the main body parallel to the central axis and rotates only around its own axis. A plurality of side shafts that are pivotally supported and on which a side bit is mounted so that the lower end is positioned axially above the center bit, and at least one of the side shafts can be driven to the main body portion. A drive motor that is provided and disposed above the attached side shaft; and a gear group that is provided on the central shaft and the side shafts and meshes with each other, and the central shaft and the drive The side shaft without a motor is Serial rotational lateral shaft driving motor is attached to and drives by the driving force of the drive motor from being transmitted to itself via the gears.

  According to the multi-axis excavator according to the first aspect of the present invention, since each bit is rotationally driven by a drive motor attached to the main body fixed to the lower end of the rod, the upper end of the rod that can be added, Support became possible on the ground without rotation. Therefore, no power device or swivel for rotation is required on the ground part. Therefore, the facilities on the ground can be configured compactly. In addition, since excavation is performed using a plurality of bits, the number of holes that can be excavated at one time is plural, so that the excavation efficiency is high. Therefore, for example, the work period can be shortened compared to the excavation method using the BH excavator.

  Further, even if the excavation hole is made smaller (for example, about φ600 mm) than a normal excavator, the swivel equipment and the drive device are unnecessary, so the rod inner diameter is increased without being restricted by the swivel equipment and the drive device. be able to. Therefore, for example, compared to the excavation method using the BH excavator, a sufficient amount of the stable liquid can be secured. As a result, the rod inner diameter can be increased without being restricted by swivel equipment and drive devices. Therefore, when adopting a configuration in which a stable liquid is passed through the pipe in the rod, the normal circulation method and the reverse circulation method are appropriately used. It can be excavated together. Therefore, earth and sand discharged by excavation can be sent to the above-ground part, and high-concentration mud and gravel can be prevented, and high-quality shafts and continuous underground walls can be constructed efficiently even in narrow areas. Can do.

Further, according to the multi-axis excavator according to the first aspect of the present invention, since the main body is fixed to the non-rotatable rod, for example, in the multi-axis excavator provided with the stabilizer disclosed in Patent Document 1 above. In comparison, twisting of the excavation hole (rotation of the central axis in the longitudinal direction of the excavation hole) can be prevented without providing a stabilizer.
Furthermore, since the rotation of the rod can be restrained, confirmation of the vertical accuracy of the excavation hole can be easily measured at any time on the ground. In addition, since the rotation of the rod is restricted, electrical signals such as hoses and drive motor wiring, piping (pressure hoses and electricity transmission lines), gyro sensors, etc. for sending and draining stable liquid to the vicinity of the bit The wire can be easily attached to the rod.

Furthermore, according to the multi-axis excavator according to the first aspect of the present invention, the plurality of side bits are arranged in parallel with the center bit and above the center bit in the axial direction. By exchanging the center bit with various diameters, excavation from a small diameter to a large diameter can be easily performed.
Further, according to the multi-axis excavator according to the first aspect of the present invention, the drive motor is disposed above the shaft portion of each side bit, and the center bit and the side bit are rotatable only around the own axis. Therefore, for example, compared with the self-revolving excavation device disclosed in Patent Document 2, the excavation area of the side bit is reduced to a range occupied by the drive motor provided above the shaft portion of the side bit in plan view. be able to. Therefore, it is possible to excavate even in a construction site that is narrower and has a smaller head. Therefore, it is suitable for excavation for the purpose of excavating a small-diameter shaft or constructing a continuous underground wall in a narrow part.

  Further, the second aspect of the present invention is the multi-axis excavator according to the first aspect of the present invention, wherein the plurality of side axes are provided in a pair symmetrically with respect to the axis of the central axis, A drive motor is provided for each of the pair of side shafts. With such a configuration, it is preferable for excavation for the purpose of constructing a continuous underground wall in which an irregularly shaped excavation hole in which three holes overlap has a small diameter (for example, about 600 mm in the short direction).

  The third aspect of the present invention is the multi-axis excavator according to the second aspect of the present invention, wherein the center bit is mounted on the lower end of the central shaft, and the side bits are mounted on the lower ends of the plurality of side shafts. Each of the mounted side bits has the same or smaller diameter than the diameter of the drilled hole of the mounted center bit, and a part of each of the drilled holes overlaps. And Such a configuration is more suitable for excavation for the purpose of constructing a continuous underground wall in which an irregularly shaped excavation hole in which three excavation holes overlap has a small diameter (for example, about 600 mm in the short direction).

  Furthermore, the fourth aspect of the present invention is the multi-axis excavator according to the third aspect of the present invention, wherein the position of each mounted side bit in the left-right direction is a line obtained by extending the axis of each side bit, The center bit is located at a position intersecting with the circumference of the drilling hole diameter of the center bit or within the circumference of the drilling hole diameter of the center bit. With such a configuration, the center position where the digging force in each side bit is weak can be set in the digging hole of the center bit. Therefore, it is even more suitable for excavation for the purpose of constructing a continuous underground wall having a small-diameter hole (for example, about 600 mm in the short direction) where the three-shaped hole is overlapped.

  Here, when drilling in the reverse circulation method with a small-diameter bit, the mouth of the drilling hole may collapse due to water injection from the ground, but the hose for stable liquid water supply and drainage is supported by the rod. By installing a water inlet and a water inlet near the bit, the stable liquid is circulated only at the bottom of the hole, and the rapid flow of the stable liquid from the ground is suppressed. The excavation by the circulation method becomes possible (the bearing capacity performance as a permanent structure can be secured).

  That is, the excavation equipment according to the fifth aspect of the present invention can form an excavation hole by a rod that can be added so as to be formed in a long column shape along the excavation direction and a plurality of drill bits fixed to the tip of the rod. A multi-axis excavator, an elevating device for raising and lowering the multi-axis excavator at the above-ground portion of the rod and suspending in the excavation hole, and a stable liquid in the excavation hole by a normal circulation method or a reverse circulation method The multi-axis excavator is a multi-axis excavator according to any one of the first to fourth aspects, and the inside of the rod is the stable excavator. It is characterized by a conduit for circulating the liquid. With such a configuration, the function of a pipe line similar to that of a conventional rod can be easily adopted in the excavation equipment according to the present invention, and switching between the normal circulation method and the reverse circulation method is also easy. Of course, the multi-axis excavator according to any one of the first to fourth aspects exhibits the above-described effects.

  Further, a sixth aspect of the present invention is the excavation facility according to the fifth aspect of the present invention, wherein the rod is a double pipe having an inner pipe and an outer pipe surrounding the inner pipe, The annular portion between the outer tube and the inner tube is a conduit for circulating the stabilizing liquid. With such a configuration, a rod having both functions of a water absorption pipe and a water supply pipe can be obtained, and the rigidity of the rod becomes stronger, so that there is an advantage that hole bending is less likely to occur.

  According to a seventh aspect of the present invention, in the excavation equipment according to the fifth aspect of the present invention, the stabilizing liquid circulation facility circulates the stabilizing liquid in the excavation hole by a reverse circulation method. A water supply hose for supplying a stable liquid from the water to the excavation hole is supported along the rod. If it is such a structure, since a water supply hose is guide | induced to a drilling hole along a rod, a possibility that the inside of a hole may collapse | decrease by a reverse circulation system can be decreased.

  Further, according to an eighth aspect of the present invention, in the excavation equipment according to the seventh aspect of the present invention, a water absorption hose that sucks up the stabilizing liquid from the excavation hole and sends it to the stabilizing liquid treatment plant is supported along the rod, It is connected to the pipe line in the rod from the side of the rod. With such a configuration, a hose for feeding and draining a stable liquid (preferably having a flexibility such as a suction hose) is attached in communication with a pipe line in a rod whose rotation is restricted, Since it is arranged along the rod to the inside of the excavation hole, it is not necessary to stop the circulation of the stable liquid when adding the rod. Therefore, the excavation speed can be further improved.

Furthermore, the excavation method according to the ninth aspect of the present invention is a method of excavating a shaft excavation hole using a multi-axis excavator, wherein the multi-axis excavator is the first aspect or the second aspect of the present invention. The multi-axis excavator according to the aspect is used, and the center bit is attached to the lower end of the central shaft, and the side bits are attached to the lower ends of the plurality of side shafts. However, the drilling hole for the shaft is excavated using a drilling hole whose diameter is smaller than that of the attached center bit and within the diameter of the attached center bit. .
With such a configuration, excavation of a shaft excavation hole from a small diameter to a large diameter can be facilitated by variously changing the diameter of the center bit. Of course, the multi-axis excavator according to the first aspect or the second aspect of the present invention used in the excavation method according to the ninth aspect exhibits the above-described effects.

  The excavation method according to the tenth aspect of the present invention is a method for continuously excavating a drill hole for a continuous underground wall using a multi-axis excavator, wherein the multi-axis excavator is a third aspect. Alternatively, using the multi-axis excavator according to the fourth aspect, the subsequent excavation hole to be excavated is excavated so that the excavation holes by the side bits overlap with the adjacent previous excavation holes and excavation by the center bit. It is characterized by excavation so that the holes do not overlap.

  With such a configuration, the center bit positioned below in the axial direction drills prior to the drilling by the side bit without being affected by the adjacent preceding drilling hole, so the center bit functions as a pilot. . As a result, the side bit located in the axially upper direction is less likely to cause twisting or bending of the excavation hole. Therefore, it is suitable for excavation for the purpose of constructing a continuous underground wall in which the excavation hole in which the three holes overlap has a small diameter (for example, about 600 mm in the short direction). Needless to say, the multi-axis excavator according to the third aspect or the fourth aspect of the present invention used in the excavation method according to the tenth aspect exhibits the above-described effects.

  As described above, according to the present invention, it is possible to efficiently excavate a drill hole for constructing a small-diameter standing pile or a continuous underground wall even in a narrow part, while twisting or bending the drill hole. It is hard to get up, and it is possible to excavate by changing the bit blade edge from a small diameter to a large diameter.

It is a mimetic diagram explaining one embodiment of excavation equipment provided with a multi-axis excavator concerning one mode of the present invention. It is a front view which expands and shows the multi-axis excavator of FIG. 1, In this figure, one part is shown with the cross section along an axial direction. It is a figure explaining the example (example by the bit of the same diameter) of the mounting structure of a some bit, The figure (a) shows the external appearance of FIG. 2, (b) is the excavation hole (continuous underground) formed The plan view of (for wall) is shown. It is a figure explaining the other structural example of the raising / lowering apparatus which raises / lowers the multi-axis excavator which concerns on 1 aspect of this invention. It is a figure explaining the point which can perform wiring and piping easily along the rod with which rotation supporting the multi-axis excavator which concerns on 1 aspect of this invention was restrained. Another example of a multi-axis excavator according to one aspect of the present invention (in the configuration of the gear group, a configuration in which the side shaft gear of the side shaft and the center shaft gear of the center shaft are directly meshed without using an idle gear) ) Is a cross-sectional view seen from the front, showing a cross-section along the axis. The figure explaining the point which can excavate from a small diameter to a large diameter by changing the center bit with which the multi-axis excavator which concerns on 1 aspect of this invention is mounted | worn with various diameters ((a), (b)) It is. FIG. 7 is an enlarged view showing a water absorption and water supply portion of the stable liquid when the stable liquid circulation facility having the configuration shown in FIG. 1 is adopted in the multi-axis excavator shown in FIG. 6. It is a figure explaining the other structural example of the water absorption and water supply part of a stable liquid. It is a figure which shows the example of the cross-sectional shape of a rod, The figure (a) is an example of the rod shown in FIG. 1, (b), (c) and (d) are figures which show another example. It is a figure explaining one structural example of the multi-axis excavator using the double-pipe type rod shown in FIG.10 (d), The figure (a) shows the rod part in the cross section along an axial direction, FIG. 2B shows the rod portion in an exploded state. It is a figure explaining the formation example of the excavation hole in the case of constructing a continuous underground wall, The figure (a) and (b) is an example of the continuous wall in the conventional single pile, (c) is FIG. It is the example of this invention which constructs | assembles a continuous wall using the multi-axis excavator shown. It is a figure explaining the example of formation of the excavation hole in the case of constructing the continuous wall in the conventional single pile, The figure (a) is an example of a φ550mm excavation hole, The figure (b) is an example of an excavation hole of φ600mm is there. It is an example of the present invention which constructs a continuous wall using the multi-axis excavator shown in FIG. 6, wherein (a) is a plan view of the formed excavation hole, and (b) is a perspective view of the formed excavation hole. Is schematically shown.

Hereinafter, an embodiment of a multi-axis excavator according to an aspect of the present invention will be described with reference to the drawings as appropriate.
The excavation facility shown in FIG. 1 is a multi-axis excavator 1 for excavating an excavation hole H, and a crawler crane that is an elevator device for raising and lowering the multi-axis excavator 1 in the excavation hole H to perform hanging excavation. 2 and a stabilizing liquid circulation facility 3 that circulates the stabilizing liquid in the excavation hole H (note that the arrows in the figure indicate the direction of circulation of the stabilizing liquid).

  In the multi-axis excavator 1, the tip of a steel rod 10 is fixed to the upper center of the main body 20. The rod 10 is formed in a long column shape along the excavation direction by connecting a plurality of rods 10 ′ that can be added by a flange at the end. The rod 10 'has a cylindrical pipe and a flange formed at the end thereof. A plurality of through holes are formed in the flange along the circumferential direction so that bolts and nuts can be coupled to each other with respect to other flanges. Further, a plurality of, for example, convex splines are formed on the outer peripheral surface of the rod 10 ′ along the axial direction.

  And the rod 10 is fitted so that this spline may become a slip pair with respect to the recessed part of the reaction force receiving table 111 fixed to the ground part. The reaction force receiving table 111 is fixed to a ground structure (for example, a steel material constituting a pit) with a clamp (for example, Bullman (registered trademark)) or the like. As a result, the rod 10 is supported so as not to rotate around the axis, although movement in the axial direction is allowed.

  A rod suspension 12 is attached to the upper end of the rod 10. The rod hanger 12 supports the rod 10 through itself by connecting the upper end of the rod 10 below and engaging the hook of the crawler crane 2 on the upper side. As a result, the crawler crane 2 hangs the multi-axis excavator 1 at the tip of the rod 10 into the excavation hole H via the rod hoist 12 and moves the excavated surface such as the ground downward in the vertical direction. Can be suspended.

  The stabilizing liquid circulation facility 3 is constituted by a series of pipes and pumps indicated by reference numerals 10, 12, 121, 120, 123, 130, 131, 132, 122 and the like in the figure. Specifically, the rod 10 is formed into a pipe line by making the inside of the cylindrical pipe hollow, and this pipe line communicates with an opening that opens at the tip of a center bit 53 described later. Further, the rod suspension 12 has a hollow pipe line inside, and the pipe line communicates with a pipe line inside the rod 10 and also communicates with a water absorption hose 121 connected to the upper part thereof. The water absorption hose 121 is connected to the suction pump 120. A drainage hose 123 is connected to the discharge side of the suction pump 120, and the drainage hose 123 is piped to the stable liquid treatment plant 130 via an earth and sand separator (for example, a mud screen) 124. A sand pump 131 is disposed in the stable liquid treatment plant 130, and discharge pipes 132 of the sand pump 131 are supported at a plurality of positions along the rod 10 and are supplied to the inside of the excavation hole H. Connected to the upper end of the hose 122.

  As a result, the stable liquid circulation facility 3 allows the muddy water in the excavation hole H to flow from the tip of the center bit 53 of the multi-axis excavator 1 to the conduit in the rod 10 to the conduit in the rod suspension 12 to the water absorption hose 121. -Through the suction pump 120 in order, the muddy water separated by the earth and sand separator 124 (or may be naturally subsidized) is recovered in the stable liquid treatment plant 130 as a stable liquid. Then, the recovered stable liquid is circulated through the reverse circulation system in which the recovered stable liquid is supplied again from the water supply hose 122 to the vicinity of the multi-axis excavator 1 in the excavation hole H via the discharge pipe 132 of the sand pump 131. It is possible.

  Here, the multi-axis excavator 1 has a central shaft 51 coaxially with the rod 10 at the left and right center of the main body 20 fixed to the lower end of the rod 10 as shown in FIG. Has been placed. The central shaft 51 is pivotally supported only around its own axis by being supported by the main body 20 via the bearing 50 at the top and bottom. Further, a flange 51f is provided at the lower end of the central shaft 51, and a mounting portion 54 for the center bit 53 is mounted on the flange 51f. The central shaft 51 has a hollow cylindrical shape, and the inside communicates with a pipe line in the rod 10 in the stable liquid circulation facility 3. Also, the center bit 53 to be mounted has a pipe line penetrating from the tip to the mounting part 54 in the center, and guides muddy water from the opening at the tip to the pipe in the rod 10. Can be done.

  Further, a pair of (two) side shafts 34, 34 are arranged on the left and right sides of the main body 20 in parallel with the central shaft 51 and symmetrically with respect to the axis of the central shaft 51. Each of the side shafts 34 and 34 is supported by the main body portion 20 via the bearing 50 so that the side shafts 34 and 34 are pivotally supported only around their own axes. Further, flanges 34f and 34f are provided at the lower ends of the side shafts 34 and 34, respectively, and the mounting portions 37 and 37 of the side bits 36 and 36 are mounted on the flanges 34f and 34f, respectively. ing.

  Here, the left and right side bits 36 and 36 are positioned axially above the center bit 53 so that the center bit 53 at the center of the main body 20 and the left and right side bits 36 and 36 do not interfere with each other. The positions in the axial direction are made different. In the present embodiment, the length of the shaft portion of the mounting portions 37, 37 of the left and right side bits 36, 36 is made shorter than the length of the shaft portion of the mounting portion 54 of the center bit 53, thereby making the shaft more than the center bit 53. Left and right side bits 36, 36 are mounted so as to be positioned upward in the direction. In the present embodiment, the center center bit 53 and the left and right side bits 36, 36 both use bits having the same diameter as the drill holes, so that three drill holes having the same diameter overlap. It is a structural example which can form a shape excavation hole (refer FIG.3 (b)). In addition, each bit diameter (excavation hole diameter) is the same diameter in the case of a continuous column pile, and the bit diameter is about φ500 mm to φ700 mm.

  Each of the side bits 36 is driven by an electric motor 32 that is a drive motor attached to the main body 20. Each electric motor 32 is attached to the main body 20 at a position coaxial with the side shafts 34 and 34 of the side bits 36 and 36 and above the shafts of the side shafts 34 and 34. In the example of the present embodiment, the electric motor 32 is connected to a ground power source via an unillustrated electric wire (for example, a captyre cable), and necessary power is supplied from the power source. The output shaft of the electric motor 32 is connected to the side shafts 34 and 34 via the speed reducer 33. When the electric motor 32 rotates, the driving force decelerated by the speed reducer 33 is applied to the side shafts 34 and 34. As a result, the left and right side bits 36 and 36 are rotated at their intended torques. In the example of this embodiment, the center bit 53 and the left and right side bits 36, 36 constitute a “plurality of drill bits”.

  A gear group is provided inside the main body 20. The gear groups are provided on the central shaft 51 and the side shafts 34 and 34, respectively, and mesh with each other so that gears can be driven in conjunction with each other. That is, the central shaft 51 is driven by the driving force of each electric motor 32 by transmitting the rotation of the left and right side shafts 34 to itself via the gear group. The gear group of this embodiment is an example in which the side shaft gears 35 and 35 of the two side shafts 34 and 34 rotated by the respective electric motors 32 and the central shaft gear 52 are linked via the idle gears 41 and 41. . Thereby, the center bit 53 is rotated by the driving force of the electric motor 32 by transmitting the rotation of the side shafts 34, 34 driving the side bits 36, 36 to the central shaft 51 through the gear group. It has become.

Next, the excavation method by the excavation equipment provided with the multi-axis excavator 1 and the operation and effect thereof will be described.
In the excavation work by the excavation facility, the crawler crane 2 is used as a lifting device, and the above-described multi-axis excavator 1 is suspended in the excavation hole H through the rod lifting tool 12 and the rod 10. And by driving the electric motor 32 provided in the main body part 20 of the multi-axis excavator 1, the three drill bits 53, 36, and 36 are simultaneously rotated to excavate. Simultaneously with the rotation of the three drill bits 53, 36, 36, the stabilizing liquid circulating equipment 3 guides muddy water from the opening at the tip of the center bit 53 to the sediment separator 124 through the pipe line in the rod 10. The earth and sand separator 124 collects the earth and sand separated from the muddy water (or may be spontaneously subsidized) as a stable liquid in the stable liquid treatment plant 130. Then, the recovered stable liquid is excavated by a reverse circulation method in which the recovered stable liquid is supplied again from the water supply hose 122 to the vicinity of the multi-axis excavator 1 in the excavation hole H.

  In such excavation work, according to the multi-axis excavator 1 described above, excavation is performed in a shape in which three excavation holes are overlapped by two side bits 36 and 36 and one center bit 53 for a continuous column pile. (See FIG. 3B). Therefore, since the excavation is performed using the plurality of bits 53, 36, and 36, the number of holes that can be excavated at one time is plural, so that the excavation efficiency is high. Therefore, for example, the work period can be shortened compared to the excavation method using the BH excavator.

  In particular, according to the multi-axis excavator 1, the rod 10 that can be added is supported at the upper end thereof by the ground reaction force receiving table 111 so as not to rotate, and the main body 20 is fixed to the lower end of the rod 10. Since the electric motor 32 is attached to the part 20 and the respective bits 53, 36, 36 are rotationally driven, a power device or swivel for rotation is not required on the ground part. Therefore, according to the multi-axis excavator 1, since the main body 20 is fixed to the non-rotatable rod 10, the excavation hole H is prevented from being twisted.

  Moreover, since the power unit and swivel for rotation are not required on the ground part, the ground part facility is small. Therefore, it is possible to excavate even in a narrow and empty construction site. In other words, the above-described features of the multi-axis excavator 1 greatly increase the degree of freedom in the configuration of the ground equipment. Thus, for example, in the above-described embodiment, the example in which the rod suspension 12 and the crawler crane 2 are used as the lifting device has been described. However, as in the other configuration example illustrated in FIG. 4, the rod suspension 12 and the crawler crane are used. 2 may be excavated by supporting the multi-axis excavator 1 in a suspended manner by a lifting device using a hydraulic cylinder 140, a pulley (for example, using ball bearings) 150, or the like.

  Specifically, in the example of the figure, a rod suspension 13 is fixed to the upper end portion of the rod 10, and a pair of hydraulic cylinders 140 are arranged on both sides of the rod suspension 13. The rod suspension 13 has a two-sided width portion 13 a that is slidably guided at both right and left ends, and the two-sided width portion 13 a is sandwiched between slide guide surfaces 15 formed on the tower 111. As a result, the rod suspension 13 is slidable in the axial direction of the rod 10, but cannot rotate about the axis. Each hydraulic cylinder 140 has a rotatable pulley 150 fixed to the tip of a vertically extendable rod, and a wire 14 is wound around the pulley 150. One end of the wire 14 is fixed to the tower 111 and the other end is fixed to the rod suspension 13. As a result, the rod suspension 13 moves up and down along the slide guide surface 15 via the wound wire 14 by synchronizing the pair of hydraulic cylinders 140 to expand and contract the rod. Therefore, the rod 10 fixed to the rod suspension 13 is moved up and down, and the multi-axis excavator 1 at the lower end of the rod 10 can be moved in the vertical direction while restricting the rotation. Accordingly, since the ground equipment can be made compact with such a configuration, it is suitable as ground equipment (elevating device) for excavation in a construction site that is narrow and has a small sky head.

  Further, according to the multi-axis excavator 1, since the rotation of the rod 10 is constrained, the wiring 9 for the electric motor 32 and the piping for the hydraulic motor are provided along the rod 10 as shown in FIG. Moreover, confirmation of the vertical accuracy of the excavation hole H can be measured at any time on the ground. That is, as shown in the figure, for confirmation of the vertical accuracy of the excavation hole H, it is possible to easily attach a signal line 8 for sending a signal of a sensor 7 such as a gyro sensor to the rod 10.

  Further, according to the multi-axis excavator 1, since the swivel equipment and the drive device are unnecessary, the inner diameter of the rod 10 can be increased without being restricted by the swivel equipment and the drive device. For example, compared to a normal excavator, the inner diameter of the rod 10 can be increased even if the excavation hole H is reduced to about 600 mm in the short direction of the excavation hole H where three excavation holes overlap. Therefore, when adopting the configuration in which the stabilizing liquid is passed through the pipe line in the rod 10 as in the above-described embodiment, excavation can be performed by appropriately combining the normal circulation method and the reverse circulation method. Therefore, for example, compared to the excavation method using the BH excavator, a sufficient amount of the stable liquid can be secured. Therefore, since the earth and sand discharged by excavation can be sent to the above-ground part, high-concentration muddy water and gravel can be prevented from remaining, and a high-quality continuous underground wall can be constructed efficiently even in a narrow part. .

Here, when excavating by a reverse circulation method using a small-diameter bit, the mouth of the excavation hole H may collapse due to water injection from the ground. However, according to the multi-axis excavator 1, since the rotation of the rod 10 is constrained, it is easy to make the rod 10 feed a stable liquid water supply hose or a drain hose.
The multi-axis excavator according to the present invention, the excavation equipment provided with the same, and the excavation method are not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention. It is.

  For example, in the embodiment shown in FIG. 2, when the side shafts 34, 34 are rotated by the drive motor such as the electric motor 32, the side shaft gears 35, 35 are interlocked via the idle gears 41, 41. In this example, the gear group that is driven by rotating is described. However, the present invention is not limited to this. For example, the modification shown in FIG. 6 has a configuration in which the side shaft gears 35 and 35 of the side shafts 34 and 34 and the center shaft gear 52 of the center shaft 51 are directly meshed without using the idle gears 41 and 41. It is an example of a gear group.

Also in the multi-axis excavator 1 of this modification, the electric motor 32 is arranged coaxially with the side shafts 34 and 34 for driving the side bits 36 and 36 and above the shaft portion, and further, the center bit. 53 and the side bits 36 and 36 are rotatable only around their own axes, so that the side bits 36 and 36 are excavated to the extent occupied by the electric motor 32 provided above the side bits 36 and 36 in plan view. The area can be reduced in diameter.
Further, according to the multi-axis excavator 1 of this modification, the left and right side bits 36, 36 are parallel to the center bit 53 and more axial than the center bit 53, as in the multi-axis excavator 1 of the above embodiment. As shown in FIG. 7, excavation from a small diameter to a large diameter can be easily performed by replacing the center bit 53 with various diameters as shown in FIG.

  In particular, according to the multi-axis excavator 1 of this modified example, the side shaft gears 35, 35 of the side shafts 34, 34 without the idle gears 41, 41 are compared with the embodiment shown in FIG. And the central shaft gear 52 of the central shaft 51 are directly meshed with each other, so that the distance between the left and right side bits 36 can be made more compact. Therefore, it is more suitable for excavation in a construction site that is narrow and has a small head. That is, as shown in FIG. 7A, if the bit configuration is such that the three bits 53, 36, and 36 overlap in a plan view, an irregularly shaped excavation hole in which the three excavation holes overlap each other has a small diameter (for example, in the short direction). It is more suitable for excavation for the purpose of constructing a continuous underground wall of about 600 mm). Here, the example shown in FIG. 6 (FIG. 7A) is an example in which a bit having a size in which the drilling hole diameter D of the center bit 53 is positioned on the axis line CL of the left and right side bits 36, 36 is mounted. With such a configuration, since the center position where the digging force at each side bit 36, 36 is weak is located on the diameter of the digging hole of the center bit 53, the position where the digging force at each side bit 36, 36 is weak. It is more suitable for excavation for the purpose of constructing a continuous underground wall with a small diameter (for example, about 600 mm in the short direction) while assisting, with an irregularly shaped excavated hole in which three excavated holes overlap. This effect can also be achieved by setting the center position where the excavation force at each side bit 36, 36 is weak within the excavation hole diameter of the center bit 53. FIG. 2B is an example in which the entire drilling hole diameters of the left and right side bits 36 and 36 are located within the drilling hole diameter of the center bit 53. Such a configuration is suitable for excavating a single shaft.

  Further, similarly to the multi-axis excavator 1 of the above-described embodiment, in this modified example, since the rotation of the rod 10 is restricted, it is easy to make the rod 10 feed a stable liquid water supply hose or a drain hose. It is. Specifically, as shown in an enlarged view of the main part in FIG. 8, the water inlet 53 a is an opening at the tip of the center bit 53, and the vicinity of the main body 20 of the multi-axis excavator 1 (in the example of FIG. A stable liquid water supply hose 122 can be supported along the rod 10 up to a position directly above the motor 32 and disposed in the excavation hole H. As a result, the water supply port 122a is provided in the vicinity of the bit, and the water suction port 53a is used as the tip of the bit, so that the stable liquid can be recovered through the conduit in the rod 10. Therefore, it is possible to circulate the stable liquid only at the bottom of the excavation hole H and eliminate the rapid flow of the stable liquid from the ground. Therefore, even if the excavation hole H has a small diameter, excavation by the reverse circulation method can be performed (supporting performance as a permanent structure can be ensured).

  Furthermore, in this modified example (same for the multi-axis excavator 1 of the above embodiment), since the rotation of the rod 10 is constrained, as shown in FIG. 9, a stable water supply hose 122 (such as a suction hose) is used. A material having flexibility and flexibility is preferably supported along the rod 10 and disposed in the excavation hole H. Then, a water absorption hose 121 (preferably a suction hose or the like having flexibility and flexibility) that sucks up the stable liquid from the excavation hole H and sends it to the stable liquid treatment plant (130) is supported along the rod 10. Thereby, while arrange | positioning to the inside of the excavation hole H, it can pipe so that it may communicate with the pipe line in the rod 10 from the side surface of the rod 10 located in the excavation hole H. With such a configuration, the supply of the stabilizing liquid to be circulated is stopped when the rod 10 is added by attaching the hoses 121 and 122 for feeding and discharging the stabilizing liquid to the rod 10 whose rotation is restricted. Is unnecessary, so the excavation speed can be improved. In this example, the upper end of the rod 10 is suspended directly into the excavation hole H by the crawler crane 2 without using the rod lifting tool 12.

  Further, for example, in the multi-axis excavator 1 of the above-described embodiment, the rod 10 has a plurality of strips (in the figure, along the axial direction of the pipe (pipe) 10c, as shown in a cross-sectional view in FIG. 10A). 4), the spline 10a is formed and the flange 10b is attached to the rod end. However, the present invention is not limited to this, and the rod that can be used in the multi-axis excavator according to the present invention includes If the side can be supported in a non-rotatable manner (supported in a state where rotation is constrained), various configurations can be adopted.

  For example, as shown in FIG. 5B, a configuration in which a flange 10b is attached to an end of an annular pipe 10c may be adopted. In addition, if the hose for water supply or water supply is supported along the outside of the rod 10 that is non-rotatably supported (for example, connected at each predetermined distance) (for example, see FIG. 9 illustrated above), the rod 10 It does not have to be tubular. Specifically, the rod 10 may be configured by combining a plurality of plate members 10t in a radial shape (a cross shape in the example shown in the figure) as in the example shown in FIG.

  Further, for example, the rod 10 may be constituted by a double pipe having both functions of a water absorption pipe and a water supply pipe. Specifically, as shown in FIG. 4D, the rod 10 has an inner tube 10c and an outer tube 10d surrounding the inner tube 10c. In the double pipe of this example, the inner pipe 10c is a water absorption pipe (a shape through which earth and sand and gravel can pass), and the space between the outer pipe 10d and the inner pipe 10c (the annular portion) is a water supply pipe. The inner tube 10c having a diameter of about 200 mm is coaxially included in the outer tube 10d having a diameter of about 250 mm. The inner tube 10c and the outer tube 10d are connected to each other at a plurality of locations in the circumferential direction by a connecting member 10e. Around the end of the outer tube 10d, there is provided a flange 10b that can be coupled with a bolt and a nut. And this double tube | pipe type rod 10 is connected with respect to the above-mentioned multi-axis excavator 1 as shown, for example in FIG.

  That is, as shown in the figure, a double pipe type connecting portion 17 is attached to the center upper portion of the main body portion 20 of the multi-axis excavator 1. The cross section of the connecting portion 17 has the same shape as that shown in FIG. 10 (d), and is connected by bolts and nuts by mutual flanges. An annular coupling packing 16 is fitted into a joint portion between the coupling portion 17 and the rod 10, and thereby, between the inner tube 10 c serving as a water absorption tube and the outer tube 10 d serving as a water supply tube and the inner tube 10 c (annular). Leakage of the stable liquid between these parts is prevented. A double pipe type connecting pipe 18 is also attached to the upper end portion of the connected double pipe type rod 10. The cross-section of the connecting pipe 18 is basically the same as that shown in FIG. 10D, but the end of the outer tube 18d is a blind hole, and the opening 18k on the side surface of the outer tube 18d is formed. The discharge pipe 132 is connected to the tip. On the other hand, the inner pipe 18 c of the connecting pipe 18 is also opened at the end, and is connected to the tip of the water absorption hose 121.

  With such a configuration, in addition to the effects of the other pipes described above, the rigidity of the rod 10 becomes stronger, so that there is an advantage that hole bending is less likely to occur. In addition, even if the diameter of the rod 10 is increased by adopting a double tube type, as described in the operation effect of the multi-axis excavator 1 described above, a ground unit (a driving device or a swivel) is unnecessary. The machine does not become large even if it is a double pipe type. In the conventional reverse circulation method, when the rod diameter is increased, the flow velocity outside the pipe increases, and there is a risk of mud loss. On the other hand, the drilling hole using the multi-axis excavator 1 according to the present invention has a bottom of the drilling hole. This is not a problem because the dynamic circulation of the stabilizing liquid is performed.

  Here, in the multi-axis excavator 1 of the modified example shown in FIG. 6, the two side bits 36, 36 and the center bit 53 overlap each other in plan view. The side bits 36 and 36 are rearward of the center bit 53 in the direction, and the circumference of the side bits 36 and 36 protrudes on the opposite side of the center shaft 51 from the circumference of the center bit 53.

  Accordingly, according to the modified multi-axis excavator 1 shown in FIG. 6, the central excavation hole excavated by the center bit 53 at the tip of the central shaft gear 52 and the central excavation hole are arranged side by side at the same time. It is possible to excavate an irregularly shaped excavation hole H composed of two parallel holes to be excavated. And if it is such a structure, when building a continuous wall using the bit shown in FIG. 6 (or FIG. 7 (a)), as shown in FIG. Compared with the continuous wall in (a) and (b)), the speed of constructing the continuous wall is high (see (c) in the same figure), the amount of mud soil is small, and there is an advantage that hole bending hardly occurs. The example shown in FIG. 12 includes a single-axis φ550 mm drill bit, a single-axis φ600 mm drill bit, and a three-axis drill bit (center bit φ600 mm, left and right) shown in FIG. 6 (or FIG. 7A). It is a comparison figure at the time of constructing | assembling a continuous underground wall using the side bit (phi) of 320 mm and the horizontal direction total length of 920 mm.

  That is, when a continuous underground wall is constructed by a single pile, as shown in FIGS. 13A and 13B, a shaft Hs (shown by a solid line in the figure) is first excavated and an H-shaped steel material is excavated. It is inserted into the hole Hs and filled with a solidifying agent to be solidified (or a core material is inserted after injecting the solidifying agent). Next, the succeeding excavation hole Hk (the same as the excavation hole Hs) overlapped with a part of the excavation hole diameter between the two single piles (excavation hole Hs) and the single pile (excavation hole Hs) constructed in advance. Excavate (shown in broken line in figure). Here, the reason why the subsequent excavation hole Hk is excavated by duplicating a part of the excavation hole is for the purpose of earth retaining and water stopping, but conventionally, two preceding piles (excavation holes Hs) ) The solidification strength is not the same due to the difference in solidification time, and the pile core of the succeeding pile (excavation hole Hk) is displaced due to the difference in hardness between the ground and the solidifying agent of the preceding pile (excavation hole Hs). As a result, there was a problem that it did not function as a soil retaining or water stop.

  On the other hand, according to the bit configuration of the multi-axis excavator 1 shown in FIG. 6 (or FIG. 7A), as shown in the schematic diagram of FIG. A subsequent excavation hole Hk (shown by a broken line in the figure) is excavated while overlapping part of the excavation hole diameters of the left and right side bits 36, 36 between the excavation holes Hs). At this time, first, the center bit 53 excavates the ground between the left and right preceding piles (excavation holes Hs), and the left and right side bits 36, 36 are rearward of the center bit 53 in the axial direction (upward in the vertical direction). Therefore, excavation is performed after the preceding pile (excavation hole Hs). Therefore, even if a force deviating from the pile core acts on the side bits 36, 36, the preceding center bit 53 serves as a pilot, so that the pile core is prevented from shifting. Further, twisting of the pile core in the rotation direction is prevented because the rod 10 is supported so as not to rotate on the ground portion.

  Furthermore, in FIG. 12, the lengths of the continuous underground walls that can be constructed by the ten excavation holes H are 4500 mm (same figure (a)), 5100 mm (same figure (b)), 7760 mm (same figure (c)). ) And the construction speed of the continuous underground wall is the fastest in the three-axis drill bit of the present invention shown in FIG. 6 (or FIG. 7A). The circumferential lengths of the overlapping portions of adjacent excavation holes H are almost the same as 336 mm (Fig. (A)), 350 mm (Fig. (B)), and 335 mm (Fig. (C)). Water performance does not change.

Moreover, the area of the excavation hole per one excavation hole H is 0.238m < ² > (the figure (a)), 0.283m < ² > (the figure (b)), 0.378m < ² > (the figure (c) )) Therefore, although the amount of mud soil per drilling hole is large for the three-axis drill bit of the present invention, the amount of mud soil relative to the total construction length of the continuous underground wall is 10 drill bits of the present invention (total length: 7760 mm) As shown in the figure, the uniaxial φ550 mm drill bit is 4.046 m ² for 17 uniaxial φ600 mm drill bits, and it is 4.245 m ² for 15 uniaxial φ600 mm drill bits. On the other hand, in the case of the 3-axis drill bit of the present invention, the number of 10 drills is 3.78 m ² , and the amount of mud is the smallest for the 3-axis bit of the present invention.

  Here, the three-axis drill bit shown in FIG. 2 is a configuration example in which three drill holes having the same diameter can be formed to overlap each other (see FIG. 3B). However, in the case of a continuous column pile, since the diameter is generally about φ500 mm to φ700 mm, the area of the excavation hole H is a “large diameter” level. Therefore, since it is difficult to raise earth and sand to the ground in the normal circulation method, it is limited to the reverse circulation method.

  On the other hand, in the multi-axis excavator 1 of the modified example shown in FIG. 6 (or FIG. 7A), compared to the embodiment shown in FIG. The side shaft gears 35 and 35 of the 34 and 34 and the central shaft gear 52 of the central shaft 51 are directly meshed with each other, and the three-axis drill bit has a circumference (diameter D) of the center bit 53 on the left and right sides. Since the bit 36, 36 having a size located on the axis CL is mounted, the area of the excavation hole H can be set to the size of the “small diameter” level. Therefore, excavation not only by the reverse circulation method but also by the normal circulation method can be performed.

  Then, according to the modified multi-axis excavator 1 shown in FIG. 6 (or FIG. 7A), as shown in FIG. 8, the water supply hose 122 is put on the rod 10 which cannot be rotated. By providing the water supply port and the water intake port in the vicinity of the bit and circulating the stabilizing liquid at the bottom of the hole, a rapid flow from the ground toward the bottom of the hole can be suppressed even in the reverse circulation system. Therefore, the excavation hole H is prevented from collapsing and excavation by the reverse circulation method can be performed even with a small diameter.

  In addition, the multi-axis excavator according to the present invention, the excavation equipment provided with the multi-axis excavator, and the excavation method are not limited to the above-described embodiment or modification. For example, in the illustrated multi-axis excavator 1, Although the example in which the side shaft 34 (and the side bit 36) is provided as a pair (two sets) on the left and right sides of the central shaft 51 has been described, the present invention is not limited to this. For example, the side bit 36 has three or four sets. In addition, a “plurality of drill bits” may be configured together with the center center bit 53. However, for the purpose of constructing a continuous underground wall and for use in excavation at a narrow construction site with a small sky head, a plurality of side shafts 34 (and side bits 36) are paired on the left and right of the central shaft 51 ( 2 sets) are preferably provided.

For example, in the above-described embodiment, the example in which the electric motor 32 is used as the drive motor has been described. However, the present invention is not limited thereto, and various motors can be used as long as the side shaft 34 can be driven. For example, a hydraulic motor may be used.
Further, for example, in the above-described embodiment, the example in which the drive motor (electric motor 32) is arranged on each side shaft 34 has been described. However, the present invention is not limited to this, and the drive motor has at least one of the side shafts 34. What is necessary is just to be arrange | positioned to the said main part 20 so that it can drive, and to be arrange | positioned coaxially with the said side axis 34 and the upper side of the said side axis 34 attached. However, in order to obtain a necessary and sufficient torque while distributing the driving force equally and balance the reaction force of the entire multi-axis excavator 1, it is preferable to dispose a driving motor on each side shaft 34. When the side shaft 34 not provided with a drive motor is provided, the side shaft 34 provided with no drive motor is rotated by the rotation of the side shaft provided with the drive motor through the gear group described above. It can be configured to be driven by the driving force of the drive motor.

  Further, for example, in the excavation equipment and the excavation method described in the above embodiment or modification, the reverse circulation method has been described as the method for circulating the stabilizing liquid in the excavation hole H. Of course, it is possible to adopt a circulation method, and the mutual circulation method may be switched as appropriate.

1 Multi-axis excavator 2 Crawler crane (lifting device)
3 Stabilizing liquid circulation equipment 10 Rod 20 Main body 32 Electric motor (drive motor)
34 Side shaft 35 Side shaft gear (gears constituting “gear group”)
36 Side Bit 41 Idle Gear (Gear that constitutes "Gear Group")
51 Center shaft 52 Center shaft gear (gears constituting “gear group”)
53 Center bit

Claims (10)

  A main body fixed to the lower end of an extendable rod that is supported non-rotatably on the ground, and a center that is pivotally supported around the axis of the main body so as to be rotatable about its own axis, and a center bit is attached to the lower end. A side of the main body that is disposed in parallel to the shaft and parallel to the central shaft and is pivotally supported only around the shaft so that the lower end is positioned above the center bit in the axial direction. A plurality of side shafts to which a bit is mounted, a drive motor that is attached to the main body so as to be able to drive at least one of the side shafts, and that is disposed above the attached side shaft; A central axis and a gear group provided on each side axis and meshing with each other, and the side axis not provided with the central axis and the drive motor rotates the side axis provided with the drive motor. Through the gear group Multi-axis drilling machine, characterized in that the driving by the driving force of the drive motor from being transmitted.   The plurality of side shafts are provided in only one pair symmetrically with respect to the axis of the central axis, and the drive motor is provided for each of the pair of side shafts. The multi-axis excavator according to claim 1.   The center bit is attached to the lower end of the central shaft, and the side bits are attached to the lower ends of the plurality of side shafts. Each of the attached side bits has a center where the diameter of the excavation hole is attached. The multi-axis excavator according to claim 2, wherein the drilling hole diameter of the bit is equal to or smaller than that of the bit and a part of the mutual drilling holes is overlapped.   The position of each mounted side bit in the left-right direction is such that the line extending the axis of each side bit intersects the circumference of the drilling hole diameter of the center bit or within the circumference of the drilling hole diameter of the center bit. The multi-axis excavator according to claim 3, wherein the multi-axis excavator is located. A rod that can be added so as to be formed in a long column shape along the excavation direction, a multi-axis excavator capable of forming a drill hole by a plurality of drill bits fixed to the tip of the rod, and the multi-axis excavator An excavation facility comprising an elevating device for lifting and lowering in the excavation hole by raising and lowering the rod above the ground, and a stable liquid circulation facility for circulating a stable liquid in the excavation hole by a normal circulation method or a reverse circulation method. And
The multi-axis excavator is the multi-axis excavator according to any one of claims 1 to 4, wherein the rod has a conduit for circulating the stabilizing liquid. Facility.   The rod is a double tube having an inner tube and an outer tube surrounding the inner tube, and an annular portion in the inner tube and between the outer tube and the inner tube circulates the stabilizing liquid, respectively. 6. The excavation facility according to claim 5, wherein the excavation facility is a pipeline.   The stabilizing liquid circulation facility circulates the stabilizing liquid in the excavation hole by a reverse circulation method, and a water supply hose for supplying the stabilizing liquid from the stabilizing liquid treatment plant to the excavation hole is supported along the rod. The excavation equipment according to claim 5, wherein   A water absorption hose that sucks up the stabilizing liquid from the excavation hole and sends it to the stabilizing liquid treatment plant is supported along the rod and communicated with a pipe line in the rod from a side surface of the rod. Item 8. The excavation equipment according to item 7. A method of drilling a shaft hole using a multi-axis excavator,
Using the multi-axis excavator according to claim 1 or 2 as the multi-axis excavator, mounting the center bit at the lower end of the central shaft, and mounting the side bits at the lower ends of the plurality of side shafts, In the mounted state, each mounted side bit is a vertical shaft using the one whose drilling hole diameter is smaller than the drilling hole diameter of the mounted center bit and within the drilling hole diameter of the mounted center bit. An excavation method characterized in that an excavation hole is excavated. A method of continuously excavating a drill hole for a continuous underground wall using a multi-axis excavator,
The multi-axis excavator according to claim 3 or 4 is used as the multi-axis excavator, and the subsequent excavation hole to be actually excavated is overlapped with the adjacent previous excavation hole by the side bit. The excavation method is characterized in that excavation is performed such that the excavation holes formed by the center bit do not overlap each other.

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