JP7112122B2 - Underground drilling rig in all-casing construction method - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an underground hole drilling apparatus in an all-casing construction method for drilling an underground hole by drilling the inside of a casing while press-fitting the casing into the ground in order to drive a cast-in-place pile as a foundation pile.

In the all-casing construction method, a casing held by a casing driver device is rotated and pressed into the ground, the earth and sand in the casing are excavated by an excavator, and the earth is discharged to the ground to excavate the underground hole. Therefore, it is possible to construct cast-in-place piles with less soil and sand around the perimeter of the pile and greater bearing capacity.

Conventionally, the excavation of underground holes in the all-casing construction method is performed by dropping a hammer grab suspended from a crane onto the excavation surface in the casing by its own weight, and by the impact of the impact, the excavation is performed. The excavation drill and excavation bucket equipped in the casing are inserted into the excavation surface in the casing and driven to rotate to excavate. However, the former excavating means has the problem of vibration and noise due to the fall of its own weight, and also has the problem that the amount of earth and sand that can be grasped at one time is small. The latter drilling means also has a problem of noise because the rotary drive source of the kelly bar exists on the ground. It will become large-sized, and the noise will also be amplified.

Therefore, in order to reduce vibration and noise, and to reduce the size and weight of the device, the applicant of the present application excavates a digging bucket of an underground hole drilling device that is detachably fixed to the inner wall of the casing, as shown in Patent Document 1. There has already been provided a underground hole drilling device (hereinafter referred to as the "Document 1 invention") that excavates by rotating while pressing against a surface and takes the excavated earth and sand into an excavating bucket.

JP-A-2002-276273

In the invention of Document 1, a rotary hydraulic motor as a rotary drive source for a kelly bar that drives an excavating bucket and a pressing hydraulic cylinder that presses the excavating bucket are integrally installed in the underground hole drilling apparatus and positioned in a casing. Therefore, noise during excavation can be reduced, and since the excavation bucket is rotated and press-fitted, there is little vibration.

When drilling underground holes, it is possible to shorten the cycle time of the drilling work while maintaining the drilling accuracy, and improve the drilling pitch to increase the number of drilling times and the amount of soil drilled per unit time. Efficiency needs to be improved. Improvement in work efficiency is required regardless of the diameter and depth of excavation of underground holes. Pile diameter of 1,200 mm, which had been the norm, has been exceeded, and there is a demand for cast-in-place piles with a pile diameter of 1,500 mm and even a larger pile diameter of 2,000 mm. It has become a challenge.

In the underground hole drilling apparatus using the kelly bar of the invention of Document 1, etc., a direct means of improving the work efficiency, particularly the drilling pitch, is to increase the rotary torque of the drilling bucket to increase the drilling capacity. It is necessary to increase the number of rotations of the hydraulic motor for rotation and appropriately decelerate it to supply high-torque rotational force from the hydraulic motor for rotation to the kelly bar. In addition, the excavation cycle time and excavation pitch are greatly affected by the soil quality of the excavated ground, and even in the case of hard ground, it is necessary to supply a high torque rotational force to the kelly bar. On the other hand, kelly bars are required to withstand high torque, transmit rotational force to excavation buckets without being damaged by deformation or abnormal wear, and be robust and durable enough to be used stably as industrial machinery.

In the invention of Document 1, a hollow drive is formed on each surface of a kelly bar 300 which has a rectangular cross section and which is a driven shaft shown in FIG. A shaft 310 is fitted to transmit the rotational force of a hollow drive shaft 310 that is rotationally driven by a rotary hydraulic motor to the outer peripheral surface of the kelly bar 300 . As shown by arrow A in FIG. Four rotational force transmission surfaces are formed from part of the inner peripheral surface. Regardless of the invention of Document 1, all the kelly bars used as the rotational force transmission mechanism of the underground hole drilling equipment in the all-casing construction method have a rectangular cross section.

In addition, although the hollow drive shaft 310 has a substantially rectangular cross section, it has an arcuate bulge, while the kelly bar 300 has a rectangular cross section. In this state, a gap 330 is created between the hollow drive shaft 310 and the kelly bar 300 that does not contribute to the transmission of rotational force.

Therefore, in the prior art in which the hollow drive shaft 310 has four rotational force transmission surfaces, the hollow drive shaft 310 has four drive points 320 and a gap 330 exists. The sense of unity and close contact between 310 and Keriba 300 was not sufficient. Although there was no particular problem with the torque used in conventional underground hole drilling, the rotational torque supplied from the rotary hydraulic motor was reduced by 1.0% from the conventional torque in order to improve the work efficiency of rotational force transmission and to cope with the increase in diameter. If the load is doubled or more, specifically, increased to 9 ton/m to 12 ton/m in the invention of Document 1, depending on the soil type, etc., excessive load may be applied, or repeated torsional load applied to the rotational force transmission surface during long-term use. As a result, the rotational force transmission surface of the kelly bar may be deformed or damaged due to abnormal wear, etc., and may become unusable. Therefore, in order to avoid interruption of work due to damage to the kelly bar, it is necessary to check for deformation and abnormal wear at any time, including daily inspections at the start and end of work. When an abnormality occurs in the work, the work may be interrupted and the excavation work interrupted for replacement of the kelly bar or maintenance.

Therefore, in order to increase the rotational torque of the excavation bucket, the present invention aims to supply a high torque rotational force from the hydraulic motor for rotation to the kelly bar. By providing a kelly bar that exhibits the robustness and durability required as an industrial machine without being subjected to damage, it is possible to improve work efficiency and provide a underground hole drilling rig in the all-casing construction method that can handle large diameters. It is an issue.

In order to achieve the object of the present invention, according to claim 1, the excavation bucket is detachably fixed to the inner wall of the casing, the excavation bucket is pressed against the excavation surface and rotated to excavate, and the excavated earth and sand are taken into the excavation bucket. An underground hole drilling rig in an all-casing construction method, in which a kelly bar for transmitting rotational force to the drilling bucket is slidably arranged on the outer circumference of a pressing hydraulic cylinder for pressing the drilling bucket, and is rotationally driven by a rotating hydraulic motor. The hollow drive shaft is fitted to the outer periphery of the kelly bar to rotate the kelly bar, and the rotating force transmission surface, which is composed of the outer peripheral surface of the kelly bar and the inner peripheral surface of the hollow drive shaft, has a hexagonal cross section, thereby reducing the power from the rotary hydraulic motor. To provide a underground hole drilling apparatus based on an all-casing construction method capable of supplying high-torque rotational force to a kelly bar via a hollow drive shaft .

More specifically, according to claim 2, the earth in the all-casing construction method is detachably fixed to the inner wall of the casing, the excavation bucket is pressed against the excavation surface and rotated to excavate, and the excavated earth and sand are taken into the excavation bucket. A hole drilling apparatus, wherein a first support and a second support are separated by a predetermined distance and connected by a support column, and a pressing bucket is pressed against the lower surface of the first support through the second support. A hydraulic cylinder is suspended, a kelly bar for transmitting rotational force to the excavation bucket is slidably arranged on the outer periphery of the pressing hydraulic cylinder, and a hollow drive shaft is rotated by a rotary hydraulic motor arranged on the second support. Rotating force generated by the outer peripheral surface of the kelly bar and the inner peripheral surface of the hollow drive shaft. Provided is an underground hole drilling apparatus in an all-casing construction method, in which high-torque rotational force can be supplied from a hydraulic motor for rotation to a kelly bar via a hollow drive shaft by forming a transmission surface with a hexagonal cross section.

Further, according to claim 3, the fixing plate is extended and retracted by extension and retraction of the fixing hydraulic cylinder mounted on the first support, and is detachably fixed at a predetermined position on the inner wall of the casing. Furthermore, according to claim 4, the rotational force transmitted from the rotary hydraulic motor to the kelly bar through the hollow drive shaft is dispersed and transmitted to the six surfaces of the rotational force transmission surface, respectively, thereby preventing deformation and abnormal wear of the kelly bar. To prevent. According to claim 5, there are six driving points for the rotational force transmission surface, and according to claim 6, the rod head is connected to the rod of the pressure hydraulic cylinder via a predetermined number of extension rods, and the rod head is provided with a bearing. By connecting the tool joint to which the excavation bucket is mounted through the joint, the excavation bucket can be moved up and down by the expansion and contraction of the pressing hydraulic cylinder.

Further, according to claim 7, by fixing the tip of the kelly bar to a tool joint to which an excavation bucket is attached, the kelly bar can be moved up and down in conjunction with the expansion and contraction of the pressing hydraulic cylinder. To provide a structure in which a kelly bar slides in a hollow drive shaft as it moves up and down.

According to the present invention described above, the hollow drive shaft that is rotationally driven by the hydraulic motor for rotation is fitted to the outer periphery of the kelly bar, and the rotational force transmission surface formed by the outer peripheral surface of the kelly bar and the inner peripheral surface of the hollow drive shaft is shown in cross section. By using a hexagonal shape, the inner peripheral surface of the hollow drive shaft and the outer peripheral surface of the kelly bar have the same cross-sectional shape. There are six driving points for the rotational force applied. Therefore, by dispersing and transmitting the rotational force transmitted from the rotary hydraulic motor to the kelly bar through the hollow drive shaft to each of the six surfaces of the rotational force transmission surface, the hollow drive shaft and the kelly bar generate the rotational torque of the excavation bucket. It is possible to withstand the increase in the torque of the rotational force supplied to the kelly bar from the hydraulic motor for rotation for raising the torque. Specifically, it is possible to cope with a torque about 1.2 to 1.6 times higher than that of the invention of Document 1. As a result, the hollow drive shaft and kelly bars are not damaged by deformation or abnormal wear, and can exhibit the robustness and durability required for industrial machinery, and can be used for a long period of time.

As a result, it becomes possible to increase the rotational torque of the excavation bucket, shortening the excavation time and making it possible to cope with hard ground. It is also possible to cope with an increase in the diameter of underground holes.

Overall layout of the underground hole drilling equipment in the all-casing construction method. (A), (B), (C), (D), and (E) process schematic diagrams of the all-casing construction method. 1 is an overall perspective view of a borehole drilling rig; FIG. FIG. 2 is a cross-sectional view of the main part of the underground hole drilling rig. FIG. 2 is an explanatory diagram of a main part in the vicinity of a support; FIG. 4 is an explanatory diagram of the main part near the hollow drive shaft; (A) Central cross-sectional view of Keri bar, (B) Front view of Keri bar. A perspective view of a Keriba. FIG. 4 is a cross-sectional view of a key part showing a fitting state between a kelly bar and a hollow drive shaft; (A) Central cross-sectional view of the hollow drive shaft, (B) Front view of the hollow drive shaft. 1 is a perspective view of a hollow drive shaft; FIG. (A) Central cross-sectional view of a conventional kelly bar, (B) Front view of a conventional kelly bar. FIG. 4 is a cross-sectional view of a main part showing a fitting state between a conventional Kelly bar and a hollow drive shaft; (A) Central longitudinal sectional view of a conventional hollow drive shaft, (B) Bottom view of a conventional hollow drive shaft.

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is an overall layout diagram of a underground hole drilling rig in the all-casing construction method, and FIG. 2 is a schematic diagram of the process. As shown in FIG. 1, a casing 5 having a bit 5a at its tip is gripped and rotated by a casing driver device 200 installed at a location where an underground hole is excavated, and is pressed into the ground to remove earth and sand from the casing 5. The underground hole is excavated by excavating with the underground hole drilling device 1 and discharging the earth to the ground.

The underground hole drilling apparatus 1 has a support cable 220 such as a wire rope suspended from a sheave 215 arranged at the tip of a jib 210 erected on a self-propelled base machine 205 such as a crawler crane through a swivel through a swivel. 1 and 2(A), and is inserted into the casing 5 as shown in FIGS. 1 and 2(A). do. In the underground hole drilling rig 1, hydraulic oil as a power source is delivered from the ground into the casing 5 through a sheave 235 equipped on the base machine 205 with a hydraulic hose 230 wound around a hydraulic hose reel 225 to a predetermined length. supply. Similarly, electric power as a power source is supplied from the ground by feeding a cabtyre cable 245 wound around a cabtyre cable reel 240 to a predetermined length into the casing 5 through a sheave 235 provided on the base machine 205 . In FIG. 1, 250 is a hydraulic unit for supplying a predetermined working oil to the underground drilling rig 1 .

Next, as shown in FIG. 2(C), the excavation bucket 10 is pressed against the excavation surface and rotated to excavate, and the excavated soil is taken into the excavation bucket 10 . When a predetermined amount of earth and sand is taken into the excavating bucket 10, the underground hole drilling device 1 is released from the inner wall of the casing 5 as shown in FIG. Next, the excavated earth and sand are removed from the excavating bucket 10, and this operation is repeated until the underground hole reaches a predetermined depth. Although the underground hole drilling apparatus 1 shown in FIG. 2 is of a different type from the present embodiment, the work process is common, and the work process of the document 1 invention is also common.

FIG. 3 is an overall perspective view of an underground hole drilling apparatus 1 according to the present invention, and FIG. 4 is a cross-sectional view of its essential parts. The first support 20 and the second support 30 are both hollow cylindrical bodies for installing necessary equipment inside. Three struts 40 are circumferentially arranged at equal intervals and connected. The first support 20 is equipped with necessary devices for controlling hydraulic oil, electric power, and the like. In addition, in the drawing, only one support column 40 is shown in order to facilitate the explanation of the configuration. FIG. 5 is an explanatory diagram of a main part near the column 40. The column 40 has a support frame 43 having a window portion 42 of a predetermined area provided upright on a column substrate 41 fixed to the upper surface of the second support 30 to support the column. A pair of left and right rods 44 are erected on the upper surface of the frame 43 with a certain interval therebetween. A first connecting hole 45 is formed in the upper end of the rod portion 44, and a bulging piece 46 is formed in the vicinity of the upper end toward the center of the underground hole drilling rig 1, and the bulging piece 46 is connected to a second connecting hole. A hole 47 is drilled.

A support bracket 21 is suspended from the lower surface of the first support 20 . The support bracket 21 includes a central shaft portion 22, a predetermined number of arms 23 radially extending from the shaft portion 22 to the edge of the lower surface of the first support 20 in accordance with the arrangement of the support columns 40, and the arm portions 23 has a connecting hole 24 for a post formed at the tip thereof. In this embodiment, three arm portions 23 are provided. The first support 20 and the strut 40 are connected by aligning the positions of 45 and fixing with the strut connecting pin 25 .

A fixing plate 55 for detachably fixing the underground hole drilling device 1 to the inner wall of the casing 5 is provided in the window portion 42 so as to extend and retract in the horizontal direction. One end of the link 56 is connected to the back surface of the fixing plate 55, and the other end of the link 56 is connected to the connecting rod 51 attached to the rod (not shown) of the fixing hydraulic cylinder 50. and the connecting rod 51 are integrally fixed to the tuning brackets 61 arranged at equal intervals on the outer periphery of the overhanging tuning jig 60 with the connecting pins 62 for tuning. The head of the fixing hydraulic cylinder 50 is fixed by a fixing connecting pin 52 to the second connecting hole 47 formed in the protruding piece 46 of the rod portion 44 of the post 40 . Therefore, by extending the rod of the fixing hydraulic cylinder 50 , the link 56 and the overhang alignment jig 60 are pushed down (see the phantom line in FIG. 4 ), and the fixing plate 55 connected to the link 56 opens the window of the column 40 . The underground hole drilling device 1 is fixed to the inner wall of the casing 5 by projecting horizontally from the portion 42 and pressing against the inner wall of the casing 5 . Also, by contracting the rod of the fixing hydraulic cylinder 50 , the link 56 and the overhanging alignment jig 60 are pushed up, and the fixing plate 55 connected to the link 56 is moved from the window 42 to within the diameter of the second support 30 . to release the underground hole drilling device 1 from the inner wall of the casing 5.

A cross-shaped suspension support bracket 26 with a bulging central portion protrudes from the upper surface of the first support 20. By connecting a support cable 220 to a suspension support hole 26a drilled in the central portion, The underground hole drilling device 1 is suspended from the jib 210 of the base machine 205 in the casing 5 so as to be freely unwound and unwound.

A pressure hydraulic cylinder 70 for vertically moving the excavation bucket 10 penetrates through the second support 30 and hangs from the center of the lower surface of the first support 20 . That is, a connecting male portion 71 formed on the head of a pressure hydraulic cylinder 70 is inserted into a connecting female portion 22a formed on the shaft portion 22 at the central portion of the support bracket 21 suspended from the lower surface of the first support 20. It is fixed by a connecting pin 72 for pressing and suspended from the first support 20 . Then, the pressure hydraulic cylinder 70 is inserted into the kelly bar 80, and the pressure hydraulic cylinder 70 and the kelly bar 80 are integrally penetrated through the through hole 63 formed in the central portion of the overhanging alignment jig 60. 2 through the support 30 . Therefore, the Kelly bar 80 can slide in the axial direction on the outer periphery of the cylinder tube 78 of the pressing hydraulic cylinder 70 and can move up and down in conjunction with the expansion and contraction of the pressing hydraulic cylinder 70 .

An enlarged diameter hat portion 81 having a diameter larger than that of the Kelly bar 80 is continuously provided at the tip of the Kelly bar 80 penetrating the second support 30, and a Kelly bar flange 81a projecting horizontally is provided on the outer periphery of the tip end of the enlarged diameter hat portion 81. forming. A bearing case 90 equipped with a bearing 92 is accommodated in the enlarged diameter hat portion 81, and a bearing case flange 90a projecting horizontally is formed on the outer periphery of the lower end thereof. In addition, 91 is a seal plate of the bearing case 90 . Reference numeral 15 denotes a tool joint for connecting the excavating bucket 10, and a tool joint flange 15a projecting horizontally is formed on the outer periphery of the upper end of the tool joint. The kelly bar flange 81a, the bearing case flange 90a, and the tool joint flange 15a have the same diameter, and are brought into close contact with each other and fixed integrally with connecting bolts 95. As shown in FIG. Therefore, the bearing case 90 and the tool joint 15 rotate integrally in conjunction with the rotation of the kelly bar 80, and the rotational force thereof is transmitted to the excavation bucket 10 attached to the tool joint 15 to rotate it.

The rod 73 of the pressing hydraulic cylinder 70 inserted into the kelly bar 80 enters the kelly bar 80, and a predetermined number of extension rods 74 of a predetermined length are connected to the distal end thereof and fixed with an extension rod fixing pin 75. A rod head 76 having a predetermined length is connected to the tip of the rod 74, and a rod head fixing pin 77 is inserted through the insertion hole 84 and fixed. The tip of the rod head 76 enters the bearing case 90 and is covered with a seal plate 91 for sealing. Since there is a gap between the kelly bar 80 and the cylinder tube 78 , the cylinder tube 78 does not rotate in conjunction with the rotation of the kelly bar 80 . However, if the rod head 76 is directly fixed to the tool joint 15 side, the rod head 76, the extension rod 74 and the rod 73 will rotate together with the keliver 80, and a piston member or the like for extending and retracting the rod 73 will be used. There is a risk of injury. Therefore, by interposing the bearing 92 between the rod head 76 and the kelly bar 80, the bearing 92 is always rotated when the kelly bar 80 rotates, absorbing the rotation of the kelly bar 80. It is kept from being transmitted to the rod 73 .

The excavation bucket 10 has a hollow portion with a predetermined capacity, and is equipped with an opening/closing lid 11 that has a bit 11a at its tip and can be opened and closed with an opening/closing shaft 12 as a fulcrum. , the bit 11a excavates the excavated surface at the bottom of the casing 5, and the excavated earth and sand can be taken into the hollow portion. The construction of this excavation bucket 10 is known.

Three rotary hydraulic motors 31 are circumferentially arranged on the upper surface of the second support 30 at regular intervals. is transmitted from the pinion gear 36 mounted on the hollow drive shaft 35 to the upper sun gear 37 and the lower sun gear 38 fitted with the needle bearing 34 as a bearing on the outer peripheral surface of the hollow drive shaft 35, and is appropriately decelerated and supplied to the hollow drive shaft 35 ( 4 and 6).

Four planetary gears 39 are circumferentially arranged at equal intervals on the upper surface of a hollow drive shaft flange 35b attached to the central portion of the hollow drive shaft 35, and mesh with the lower sun gear 38, and also serve as a second support. It meshes with an internal gear 33 arranged on the inner peripheral surface of an annular frame 32 that constitutes the body 30 . The planetary gear 39 is rotated by the torque transmitted from the lower sun gear 38 and revolves along the internal gear 33 in conjunction with the rotation of the hollow drive shaft 35 .

Therefore, the hollow drive shaft 35 is rotationally driven within the second support 30 with a predetermined torque by the upper sun gear 37 and the lower sun gear 38 which receive the rotational force from the rotary hydraulic motor 31 from the pinion gear 36 . Since the planetary gear 39 is meshed with both the lower sun gear 38 and the internal gear 33 of the annular frame 32, the hollow drive shaft 35 is stably rotationally driven while being vertically supported. Incidentally, the numbers of the rotary hydraulic motor 31 and the number of the planetary gears 39 are not limited to 3 and 4, respectively, and an appropriate number can be installed.

The hollow drive shaft 35 is fitted to the outer periphery of the kelly bar 80, and when the hollow drive shaft 35 is rotationally driven by the rotary hydraulic motor 31, it becomes a drive shaft and rotates the kelly bar 80 as a driven shaft. Therefore, in conjunction with the rotation of the kelly bar 80 , the excavating bucket 10 attached to the tool joint 15 fixed to the tip of the kelly bar 80 is rotationally driven, and the earth and sand are excavated on the bottom surface of the casing 5 .

Since the bearing 92 is interposed between the rod head 76 of the pressing hydraulic cylinder 70 and the kelly bar 80, even if the kelly bar 80 is rotationally driven, the rotational force is absorbed by the bearing 92 and is not transmitted to the rod head 76. . Therefore, even if the kelly bar 80 rotates, the pressing hydraulic cylinder 70 does not rotate.

Therefore, when the underground hole is excavated, the rod 73 of the pressing hydraulic cylinder 70 is extended to constantly press the excavation bucket 10 against the excavation surface, and the rotating hydraulic motor 31 is driven to reduce the rotational force. The excavation bucket 10 is rotated by transmitting the force to the hollow drive shaft 35 to rotate the kelly bar 80 , excavate the earth and sand, and take the excavated earth and sand into the excavation bucket 10 .

An object of the present invention is to provide a novel torque transmission mechanism to the excavating bucket 10 in order to increase the torque of the excavating bucket 10 . As a characteristic configuration for this purpose, in the present invention, the rotational force transmission surface from the hollow drive shaft 35 to the kelly bar 80 has a hexagonal cross section. This characteristic configuration will be described with reference to FIGS. 7 to 11. FIG. FIG. 7(A) is a central cross-sectional view of the kelly bar 80, (B) is its front view, and FIG. 8 is its perspective view. 10(A) is a central cross-sectional view of the hollow drive shaft 35, (B) is its front view, and FIG. 11 is its perspective view.

As shown in FIGS. 7 and 8, the kelly bar 80 is a hollow cylindrical body having a predetermined length, and its inner peripheral surface 82 is slidably arranged on the outer peripheral surface of the cylinder tube 78 of the pressing hydraulic cylinder 70. Therefore, like the cross-sectional shape of the outer peripheral surface of the cylinder tube 78, it has a circular cross-section. On the other hand, the outer peripheral surface 83 of the kelly bar 80 and the inner peripheral surface 35a of the hollow drive shaft 35, which serve as surfaces for transmitting torque from the hollow drive shaft 35 to the kelly bar 80, both have a hexagonal cross-sectional shape.

As shown in FIG. 9, the kelly bar 80 fitted to the inner peripheral surface 35a of the hollow drive shaft 35 increases the rotational force transmission surface from the conventional four surfaces to six surfaces. The rotational force transmitted to the Kelly bar 80 via 35 can be distributed and transmitted to each of the six rotational force transmission surfaces. That is, as shown by arrow A in FIG. 9, the driving points 85 of the clockwise rotational force transmitted from the hollow drive shaft 35 are six points at the corners of the kelly bar 80. Six rotational force transmission surfaces are formed from the inner peripheral surface 35a of the shaft 35 as well. As a result, it is possible to withstand higher torque than in the past, and to exhibit the robustness and durability required for industrial machinery without being damaged by deformation of the kelly bar 80 or abnormal wear. Therefore, compared to the conventional example in which the torque is transmitted to the excavating bucket 10 using a kelly bar 300 having a rectangular cross section shown in FIG. It is possible to improve work efficiency by increasing the amount of soil excavated and the amount of soil excavated, and it is also possible to respond to the recent demand for large diameter underground holes.

The present invention is characterized in that the outer peripheral surface 83 of the kelly bar 80 and the inner peripheral surface 35a of the hollow drive shaft 35 have a hexagonal cross-section, thereby forming a six-sided rotational force transmission surface. In order to improve work efficiency and cope with large-diameter underground holes, it is required to rotate the kelly bar with a torque higher than that of conventional underground hole drilling equipment. With the conventional four-sided rotational force transmission surface, deformation and abnormal wear of the rotational force transmission surface occur when used for a long period of time or when the load becomes excessive. However, it was difficult to achieve high torque because sometimes the underground drilling equipment had to be replaced. Therefore, by dispersing the rotational force transmission surfaces that receive the rotational force supplied to the Kelly bar 80 from four to six surfaces to reduce the rotational force received by each rotational force transmission surface, deformation and abnormal wear of the Kelly bar 80 can be prevented. It is possible to prevent it and respond to high torque. Specifically, the maximum torque was about 12 tons/m in the invention of Document 1, but by adopting the present invention, it was possible to increase it to 15.35 tons/m without causing wear or damage.

In addition, if the rotational force is to be dispersed, it is conceivable to increase the number of rotational force transmission surfaces to eight, ten, etc., rather than six, but increasing the number of rotational force transmission surfaces to eight or more is closer to a circle. As a result, the angle between the torque transmission direction and the transmission surface becomes smaller, the slipping force on the torque transmission surface increases when the rotation is locked, and idling occurs, resulting in loss of torque to be transmitted. Therefore, as a result of trial and error, we came up with six aspects. With six faces, it was possible to double the torque of the rotational force with the same material as the conventional one. In addition, if the rotational force transmission surface is an odd number of five or seven surfaces, the various members arranged inside the kelly bar cannot be perpendicular to each other, and the efficiency of rotational force transmission is poor, resulting in deformation and abnormal wear. , did not adopt.

According to the present invention described above, the hollow drive shaft that is rotationally driven by the hydraulic motor for rotation is fitted to the outer periphery of the kelly bar, and the rotational force transmission surface formed by the outer peripheral surface of the kelly bar and the inner peripheral surface of the hollow drive shaft is shown in cross section. By using a hexagonal shape, the inner peripheral surface of the hollow drive shaft and the outer peripheral surface of the kelly bar have the same cross-sectional shape. There are six driving points for the rotational force applied. Therefore, by dispersing and transmitting the rotational force transmitted from the rotary hydraulic motor to the kelly bar through the hollow drive shaft to each of the six surfaces of the rotational force transmission surface, the hollow drive shaft and the kelly bar generate the rotational torque of the excavation bucket. It is possible to withstand the increase in the torque of the rotational force supplied to the kelly bar from the hydraulic motor for rotation for raising the torque. Specifically, it is possible to cope with a torque about 1.2 to 1.6 times higher than that of the invention of Document 1. As a result, the hollow drive shaft and kelly bars are not damaged by deformation or abnormal wear, and can exhibit the robustness and durability required for industrial machinery, and can be used for a long period of time.

As a result, it becomes possible to increase the rotational torque of the excavation bucket, shortening the excavation time and making it possible to cope with hard ground. It is also possible to cope with an increase in the diameter of underground holes.

REFERENCE SIGNS LIST 1 underground hole drilling device 5 casing 5a bit 10 excavation bucket 11 opening/closing lid 11a bit 12 opening/closing shaft 15 tool joint 15a tool joint flange 20 first support 21 support bracket 22 shaft Portion 22a Connecting female portion 23 Arm 24 Post connection hole 25 Support post connection pin 26 Suspension support bracket 26a Suspension support hole 30 Second support 31 Hydraulic motor for rotation 32 Annular frame 33 Internal gear 34 Needle bearing 35 Hollow drive shaft 35a Inner peripheral surface 35b Hollow drive shaft flange 36 Pinion gear 37 Upper sun gear 38 Lower sun gear 39 Planetary gear 40 Strut 41 Strut substrate 42 Window 43... Support frame 44... Rod portion 45... First connecting hole 46... Swelling piece 47... Second connecting hole 50... Hydraulic cylinder for fixing 51... Connecting rod 52... Connecting pin for fixing 55... Fixing plate 56... Link 60... Projection tuning jig 61 tuning bracket 62 tuning connecting pin 63 through hole 70 pressing hydraulic cylinder 71 connecting male part 72 pressing connecting pin 73 rod 74 extension rod 75 extension rod fixing pin 76 Rod head 77 Rod head fixing pin 78 Cylinder tube 80 Kelly bar 81 Expanded hat portion 81a Kelly bar flange 82 Inner peripheral surface 83 Outer peripheral surface 85 Driving point 90 Bearing case 90a Bearing case flange 91 Seal plate 92 Bearing 200 Casing driver device 205 Base machine 210 Jib 215, 235 Sheave 220 Support rope 225 Hydraulic hose reel 230 Hydraulic hose 240 Cabtire cable reel 245 Cabtire cable 250 Hydraulic unit

Claims (8)

A underground hole drilling apparatus in an all-casing construction method in which the drilling bucket is detachably fixed to the inner wall of the casing, the drilling bucket is pressed against the drilling surface and rotated to drill, and the drilling bucket is loaded with the excavated earth and sand,
a kelly bar for transmitting rotational force to the excavation bucket is slidably arranged on the outer periphery of the pressing hydraulic cylinder that presses the excavation bucket;
A hollow drive shaft that is rotationally driven by a rotating hydraulic motor is fitted to the outer circumference of the kelly bar to rotate the kelly bar ,
By making the rotational force transmission surface consisting of the outer peripheral surface of the kelly bar and the inner peripheral surface of the hollow drive shaft a hexagonal cross section ,
An underground hole drilling apparatus in an all-casing construction method, characterized in that high-torque rotational force can be supplied to the kelly bar from a rotary hydraulic motor through a hollow drive shaft . A underground hole drilling apparatus in an all-casing construction method in which the drilling bucket is detachably fixed to the inner wall of the casing, the drilling bucket is pressed against the drilling surface and rotated to drill, and the drilling bucket is loaded with the excavated earth and sand,
The first support and the second support are separated by a predetermined distance and connected with a support,
A pressing hydraulic cylinder that penetrates the second support and presses the excavation bucket is suspended from the lower surface of the first support,
A kelly bar for transmitting rotational force to the excavation bucket is slidably arranged on the outer circumference of the pressing hydraulic cylinder,
A hollow drive shaft that is rotationally driven by a rotary hydraulic motor disposed on the second support is fitted to the outer periphery of the kelly bar to rotate the kelly bar,
The post is equipped with a fixing plate that can be extended and retracted horizontally,
By making the rotational force transmission surface consisting of the outer peripheral surface of the kelly bar and the inner peripheral surface of the hollow drive shaft a hexagonal cross section ,
An underground hole drilling apparatus in an all-casing construction method, characterized in that high-torque rotational force can be supplied to the kelly bar from a rotary hydraulic motor through a hollow drive shaft . 3. Underground in the all-casing construction method according to claim 2, wherein the fixing plate is extended and retracted by expansion and contraction of a fixing hydraulic cylinder mounted on the first support, and is detachably fixed to a predetermined position on the inner wall of the casing. hole drilling equipment. Claims 1 and 2 for preventing deformation and abnormal wear of the kelly bar by dispersing and transmitting the rotational force transmitted from the hydraulic motor for rotation to the kelly bar through the hollow drive shaft to the six surfaces of the rotational force transmission surface. Or the underground hole drilling apparatus in the all-casing construction method according to 3. 5. The underground hole drilling apparatus in the all-casing construction method according to claim 1, 2, 3 or 4, wherein the rotational force transmission surface has six driving points. A rod head is connected to the rod of the pressing hydraulic cylinder via a predetermined number of extension rods, and a tool joint to which the excavation bucket is mounted is connected to the rod head via a bearing. 6. The underground hole drilling apparatus in the all-casing construction method according to claim 1, 2, 3, 4 or 5, wherein the drilling bucket is vertically movable . 7. The underground hole drilling apparatus according to claim 6, wherein the tip of the kelly bar is fixed to a tool joint to which an excavating bucket is attached, so that the kelly bar can be moved up and down in conjunction with the expansion and contraction of the pressing hydraulic cylinder. 8. The underground hole drilling apparatus according to claim 7, wherein the kelly bar slides within the hollow drive shaft as the kelly bar moves up and down.

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