JP2023102677A - Underground hole drilling apparatus - Google Patents

Abstract

To provide an underground hole drilling apparatus in an all-casing construction method capable of drilling an underground hole having a smaller diameter than conventional ones while solving problems of noise and vibration, and capable of being fixed to an inner wall of a casing in a state in which the center of the underground hole drilling apparatus is positioned on a center line of the casing and kept horizontal.SOLUTION: A underground hole drilling apparatus in an all-casing construction method, in which a plurality of fixing plates are extended and retracted simultaneously by moving a single fixing piston, is basically provided.SELECTED DRAWING: Figure 3

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a underground hole drilling apparatus that is fixed to the inner wall of a casing by a plurality of fixing plates that can be extended and retracted in an all-casing construction method for driving cast-in-place piles as foundation piles.

In the all-casing construction method, a casing held by a casing driver device is pressed into the ground while being rotated or rocked, and the earth and sand in the casing are excavated by an excavator and discharged to the ground, thereby excavating 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 has been carried out 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, or by inserting an excavation drill or excavation bucket equipped with a kelly bar, which is a means for transmitting rotational force suspended from the crane, to the excavation surface in the casing and rotating it 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 excavation means also has a problem of noise because the rotary drive source of the kelly bar exists on the ground. Moreover, the deeper the underground hole, the longer the distance between the drill and the rotary drive source.

Therefore, in order to reduce vibration and noise, the applicant of the present application has already provided an underground hole drilling apparatus (hereinafter referred to as "the invention of Document 1") in which the excavation bucket of the underground hole drilling apparatus detachably fixed to the inner wall of the casing shown in Patent Document 1 is rotated while being pressed against the excavation surface, and the excavated earth and sand are taken into the excavation bucket.

Japanese Patent Application Laid-Open No. 2002-276273

In the invention of Document 1, a rotary hydraulic motor as a rotary drive source for a kelly bar that drives the excavation bucket to rotate, and a hydraulic pressure cylinder that presses the excavation bucket are integrated with the underground hole excavator and positioned in the casing.

The diameter of the cast-in-place pile is determined by the scale of the building or structure, the soil quality, etc., and conventionally many piles with a diameter of about 1200 mm have been driven. However, in recent years, its use has become more versatile, and while the installation of cast-in-place piles with a larger diameter than before is required due to the increase in the height of buildings and structures, the increase in the required earthquake resistance strength, etc., on the other hand, the renewal work of buildings and structures of medium and smaller scales is also increasing. Therefore, there is a demand for an underground hole drilling apparatus capable of drilling an underground hole having a smaller diameter, for example, a diameter of about 1000 mm.

In the underground hole drilling apparatus, which opens and closes the above-described hammer grab dropped by its own weight from the ground and rotates the kelly bar equipped with the drilling drill and the drilling bucket by the rotary drive source on the ground, although it is possible to drill a hole with a diameter of about 1000 mm by adjusting the size of the drilling drill, etc., it is difficult to adopt it at present, especially in construction in urban areas and urban areas.

On the other hand, although the invention of Document 1 can solve the problems of noise and vibration, it requires a space outside the keliver in the radial direction for installing a plurality of fixation plates that can be freely extended and retracted for detachably fixing the underground hole drilling rig itself to the inner wall of the casing and a plurality of fixing hydraulic cylinders for individually operating the fixing plates. In addition, since the pressing hydraulic cylinder is installed in the hollow interior of the kelly bar and the drive shaft for transmitting the rotational force to the outer peripheral surface of the kelly bar is installed outside the kelly bar, a space for installing the drive shaft is required outside the kelly bar in the radial direction.

Therefore, in the invention of Document 1, there is a limit to reducing the radial dimension of the entire underground hole drilling apparatus. That is, the invention of Document 1 has limitations on the outer dimensions of the underground hole drilling apparatus due to the structure of the fixing plate and the fixing hydraulic cylinder for operating the plate, and the structure of the pressing hydraulic cylinder, the drive shaft, and the kelly bar.

Furthermore, in the invention of Document 1, a fixing means is adopted in which a plurality of fixing hydraulic cylinders are independently actuated by the hydraulic oil supplied collectively from the hydraulic circuit, and a plurality of fixing plates connected to the rods of the respective fixing hydraulic cylinders are pressed against the inner wall of the casing to be fixed. Therefore, during the fixing work, the fixing hydraulic cylinder is operated from the fixing hydraulic cylinder with the lightest load, and the plural fixing hydraulic cylinders do not expand and contract evenly, and depending on the working situation, the fixing plate connected to the rod of the fixing hydraulic cylinder via the link varies in protrusion. As a result, in the invention of Document 1, the center of the underground hole drilling rig may deviate from the center line of the casing and be fixed in an eccentric state, or may be fixed in an inclined state due to loss of horizontal during fixing work.

In order to perform the drilling work efficiently, it is desirable to position the underground hole drilling rig on the center line of the casing and fix it to the inner wall of the casing so as to keep it horizontal. If the underground hole drilling rig is fixed at an eccentric position away from the center of the casing, or if it is fixed in an inclined state due to loss of horizontality, the excavation bucket attached to the tip cannot operate in the center of the excavation surface, the optimum position cannot be excavated, and even excavation resistance cannot be obtained.

Therefore, it is an object of the present invention to solve the problems of noise and vibration, and to provide an underground hole drilling apparatus in an all-casing construction method that is capable of drilling an underground hole having a smaller diameter than conventional ones, for example, an underground hole with a pile diameter of about 1000 mm, and that can be fixed to the inner wall of the casing in a state in which the center of the underground hole drilling apparatus is positioned on the center line of the casing and kept horizontal.

In order to solve the above-mentioned problems, as a result of intensive research on the structure of the fixing plate and the fixing hydraulic cylinder, the structure of the kelly bar, the drive shaft and the pressing hydraulic cylinder, etc. in the invention of Document 1, the conditions to be satisfied in order to solve the above-mentioned problems were clarified.
Condition 1: To reduce the influence of the extension/retraction mechanism of the fixing plate on the radial dimension of the underground drilling rig.
Condition 2: Synchronize the extending and retracting operations of a plurality of fixing plates.
Condition 3: Review the structure in which the extension and retraction operations of a plurality of fixing plates are operated by dedicated fixing hydraulic cylinders.
Condition 4: It is necessary to review the positional relationship between the conventional kelly bar and the drive shaft that rotates the kelly bar.
Condition 5: The outer diameter and inner diameter of the drive shaft should not be affected by the existence of the kelly bar.
Condition 6: The presence of the drive shaft should not affect the outer diameter and inner diameter of the kelly bar.
Condition 7: Do not let the drive shaft and kelly bar be on the same horizontal plane.
Condition 8: When reviewing the positional relationship between the kelly bar and the drive shaft, ensure that the kelly bar can be extended and retracted by the pressing hydraulic cylinder.

The inventor of the present invention is based on the premise that a plurality of fixing plates are used to stably fix the underground hole drilling device to the casing, and in order to satisfy the conditions 1 to 8 described above, the present inventors have focused on the fact that if the extension and retraction operations of the plurality of fixing plates can be performed at the same time, there is no need for a dedicated fixing hydraulic cylinder for each fixing plate, and since the underground hole digs through the casing toward the ground, there is no restriction on the vertical dimension for excavating the underground hole. Following these focus, the idea of performing the control and returning operation of multiple fixed plates at the same time by one mechanism, and arranging the drive axis and the drive axis and the keliver in the conventional diameter direction, in the track hole, or vertically, reduces the dimensions of the pile diameter of the subfole drilling device. The invention came to the present invention, gaining the idea of using the pressurized hydraulic cylinder device, which was unrelated to the rotation of Keliva, for the rotation of Keliva.

In order to solve the problem, according to claim 1, a plurality of fixing plates installed at predetermined intervals are radially extended and retracted to be detachably fixed to the inner wall of the casing, and the excavation bucket is rotated while being pressed against the excavation surface in the casing for excavation, and the excavated earth and sand are taken into the excavation bucket. provided as a basis.

According to claim 2, there is provided a configuration in which a plurality of fixing plates are arranged circumferentially at equal intervals. According to claim 3, sliding slopes formed on a plurality of sliding bodies fixed to a fixing piston made of hollow annular bodies are slidably fitted to holder slopes formed on the rear end surface of a fixing plate holder consisting of a plurality of cylindrical bodies having fixing plates fixed to their tip surfaces. To provide a configuration for extending and retracting a fixing plate by extending and retracting the fixing plate.

Further, according to claim 4, there is provided a configuration in which the lower surface of the horizontal stepped portion formed in the intermediate portion of the fixing piston is brought into close contact with the upper surface of the sliding body, according to claim 5, there is provided a configuration in which sliding projections formed on both sides of the sliding slope are fitted into holder recesses formed on both sides of the holder slope, and according to claim 6, there is provided a configuration in which a plurality of fixing plates are synchronously extended and retracted.

Further, according to claim 7, there is provided a configuration in which a cylinder tube of a pressing hydraulic cylinder that presses the excavation bucket is rotatable by a rotating hydraulic motor, and a kelly bar that transmits rotational force to the excavation bucket is fitted to the outer peripheral surface of the cylinder tube so as to be slidable and rotatable in conjunction with the rotation of the cylinder tube. do.

In addition, according to claim 10, the first support and the second support are connected by a support with a predetermined distance therebetween, a drive shaft which is rotated by a rotary hydraulic motor arranged on the second support is vertically provided from the lower surface of the second support, a cylinder tube of a pressing hydraulic cylinder for pressing the excavation bucket is rotatably connected to the tip of the drive shaft in conjunction with the rotation of the drive shaft, and a kelly bar connected to the excavation bucket is slidably and rotatably fitted to the outer peripheral surface of the cylinder tube in conjunction with the cylinder tube. Provide configuration.

According to claim 11, a hollow annular outer cylinder is fixed to the outer circumference of the lower surface of the second support, and a hollow annular inner cylinder is fixed to the inner circumference of the lower surface of the second support, and the lower surface of the outer cylinder and the lower surface of the inner cylinder are covered with a hollow bottom cover. A configuration is provided in which the rotational force transmission surface formed by the inner peripheral surface of the kelly bar is rectangular, and the rotational force of the rotary hydraulic motor is transmitted to the cylinder tube via the drive shaft and transmitted from the outer peripheral surface of the cylinder tube to the excavation bucket via the inner peripheral surface of the kelly bar.

Further, according to claim 14, there is provided a configuration in which a rotational force transmission plate is attached to the outer peripheral surface of the cylinder tube to transmit the rotational force to the inner peripheral surface of the kelly bar. According to claim 15, there is provided a configuration in which the rod of the pressing hydraulic cylinder is connected to the tip of the kelly bar. do. Furthermore, according to claim 17, there is provided a structure in which the kelly bar slides on the outer peripheral surface of the cylinder tube as the kelly bar expands and contracts.

According to the present invention described above, since the plurality of fixing plates fixed to the plurality of fixing plate holders are simultaneously expanded and retracted by moving one fixing piston in the vertical direction, the amount of protrusion and retraction of the fixing plates is equally controlled, and the plurality of fixing plates are synchronously extended and retracted. Therefore, the extension and retraction of a plurality of fixing plates are performed in synchronism, and it is possible to fix the underground hole drilling device to the inner wall of the casing in a state in which the center is always positioned on the center line of the casing and kept horizontal. Therefore, the excavating bucket mounted at the center of the tip of the underground hole drilling device can be operated at the center of the excavation surface, and the optimum location can be efficiently excavated.

In addition, since a dedicated fixing hydraulic cylinder is not required for each of the plurality of fixing plates, it is possible to reduce the influence of the extension and retraction of the fixing plates on the radial dimension of the underground hole drilling rig, which contributes to the drilling of small-diameter underground holes.

Furthermore, the kelly bar that transmits the torque to the excavation bucket and the drive shaft that transmits the torque of the hydraulic motor for rotation to the kelly bar are arranged in series on the same vertical line, so that the radial dimension of the underground hole drilling rig can be reduced. In addition, the pressing hydraulic cylinder has two functions of pressing the excavation bucket against the excavation surface and rotating the cylinder tube by the rotational force from the drive shaft, transmitting the rotational force to the kelly bar to drive the excavation bucket in rotation. Therefore, the torque can be transmitted from the drive shaft to the kelly bar via the cylinder tube of the pressing hydraulic cylinder, and the kelly bar can be extended and retracted in conjunction with the extension and retraction of the rod of the pressing hydraulic cylinder, thereby pressing the excavator against the excavation surface.

Therefore, as the use of cast-in-place piles becomes more versatile, an underground hole for driving a cast-in-place pile with a smaller diameter than a conventional pile diameter, for example, a diameter of about 1000 mm, which is smaller than a conventional pile diameter of about 1200 mm.

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. An assembly diagram of the main parts of the underground hole drilling rig. FIG. 4 is an external perspective view of a fixing portion; FIG. 3 is a perspective view of a fixing piston; The perspective view of a sliding body. The top view of a sliding body. The bottom view of a sliding body. The right side view of a sliding body. 4 is a perspective view of a fixed plate holder; FIG. FIG. 4 is a perspective view of a main part in which a sliding body is fitted in a fixed plate holder; FIG. 4 is a perspective view of a principal portion of a fixing piston to which a sliding body is fixed; FIG. 4 is a perspective view of a main part in which a sliding body fixed to a fixing piston is fitted to a fixing plate holder; FIG. 4 is a cross-sectional view of a main part of a fixing portion when extended. FIG. 11 is an explanatory view of the operation of the fixing plate during overhanging; FIG. 4 is a cross-sectional view of the main part of the fixing portion during unstretching; FIG. 11 is an explanatory view of the operation of the fixing plate at the time of stretching. Front view of the drive shaft. A perspective view of a drive shaft. (A) Perspective view of the output joint, (B) its central longitudinal sectional view. (A) Perspective view of a cylinder joint, (B) its central longitudinal sectional view. (A) A perspective view of a pressing hydraulic cylinder, (B) a partial perspective view of the head side, and (C) a vertical cross-sectional perspective view of a cylinder tube. A perspective view of a Keriba. (A) Central cross-sectional view of Keri bar, (B) Front view of Keri bar. FIG. 4 is a cross-sectional view of a main part showing a fitting state between a Kelly bar and a cylinder tube;

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 an excavation point of an underground hole, and the casing 5 is pressed into the ground while being rotated.

The underground hole drilling apparatus 1 is suspended via a swivel on a support cable 220 such as a wire rope suspended from a sheave 215 arranged at the tip of a jib 210 arranged on a self-propellable base machine 205 such as a crawler crane, inserted into the casing 5 as shown in FIGS. Hydraulic oil as a power source is supplied from the ground to the underground hole drilling rig 1 by feeding a hydraulic hose 230 wound to a predetermined length around a hydraulic hose reel 225 into the casing 5 via a sheave 235 provided on the base machine 205 . Similarly, electric power as a power source is supplied from the ground by letting out 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 excavating apparatus 1 is opened from the inner wall of the casing 5 and taken out to the ground as shown in FIG.

3 is an overall perspective view of the underground hole drilling apparatus 1 according to the present invention, FIG. 4 is a cross-sectional view of its essential parts, FIG. 5 is an assembly drawing of its essential parts, FIG. Both the first supporting body 20 and the second supporting body 30 are hollow cylindrical bodies for installing necessary equipment inside, and are spaced apart by a predetermined distance, and a predetermined number of pillars 40, in this embodiment, three pillars 40, are arranged circumferentially at equal intervals and connected. The first support 20 is equipped with necessary devices for controlling hydraulic oil, electric power, and the like. The support 40 is erected on the upper surface of the second support 30 and is fixed to a support bracket 21 formed on the lower surface of the first support 20 at its tip by a support connecting pin 22 .

A cross-shaped suspending support bracket 26 with a bulging central portion is protruded from the upper surface of the first support 20, and by connecting a supporting cable 220 to a suspending support hole 26a drilled in the central portion, the underground hole drilling apparatus 1 is suspended from the jib 210 of the base machine 205 into the casing 5 so as to be unwound and unwound.

Three rotary hydraulic motors 31 are arranged at equal intervals on the upper surface of the second support 30, and the rotational force output from each rotary hydraulic motor 31 is transmitted to three pinion gears 32 meshed with the respective output shafts, as shown in FIGS. Each pinion gear 32 meshes with a single hollow annular rotary gear 33 rotatably mounted on the inner peripheral surface of an annular frame 34 of the second support 30. The upper end surface of a rotating disk 36 having the same diameter is fixed to the lower end surface of the rotary gear 33 by appropriate means such as a connecting bolt 42. A hollow annular joint cylinder portion 37 having the same diameter is fixed to the lower end surface of the annular frame 34 by appropriate means such as a connecting bolt 43 to constitute the second support 30 .

The joint tube portion 37 on the lower surface of the second support 30 is equipped with a fixing portion 50 for detachably fixing the underground hole drilling device 1 to the inner wall of the casing 5 . The configuration of this fixing portion 50 is one of the characteristic configurations for solving the problems of the present invention. A hollow annular outer cylinder portion 53 is fixed to the outer periphery of the lower surface of the joint cylinder portion 37, and a hollow annular inner cylinder portion 54 is fixed to the inner periphery of the lower surface of the joint cylinder portion 37 by appropriate means such as connecting bolts 44 and 45, respectively. cover. The space surrounded by the outer cylindrical portion 53, the inner cylindrical portion 54, and the hollow bottom lid portion 59 is equipped with the fixing piston 51, the sliding body 56, and the fixing plate holder 52, and is formed with a hydraulic pipeline for supplying and discharging necessary hydraulic oil.

As shown in FIG. 7, the fixing piston 51 is a hollow annular body having a horizontal stepped portion 51a formed in the middle thereof, and a plurality of (six in this embodiment) sliding body recesses 51b for fitting and fixing sliding bodies 56 are formed at equal intervals in the circumferential direction from the lower surface of the horizontal stepped portion 51a toward the lower end thereof, and can be moved in the vertical direction by hydraulic pressure.

8 is a perspective view of the sliding member 56, FIG. 9 is its plan view, FIG. 10 is its bottom view, and FIG. 11 is its right side view. As shown in the figure, the sliding body 56 is a member having a substantially wedge-shaped vertical cross section, and one side surface thereof is formed as a sliding slope 56a having an inclination that is in close contact with the holder slope 52a of the fixed plate holder 52, and on both sides thereof, a continuous sliding convex portion 56b having the same inclination as the sliding slope 56a is projected. Further, the upper surface 56c of the sliding body 56 is formed as a flat surface.

FIG. 14 is a perspective view of a main portion of the fixing piston 51 to which one sliding member 56 is fixed. As shown in the figure, the sliding member 56 is closely fitted with the opposite surface of the sliding slope 56a facing the sliding member concave portion 51b of the fixing piston 51, and fixed by an appropriate means such as a connecting bolt. As a result, the sliding body 56 opens the sliding slope 56a in the radial direction of the fixing piston 51, and is fixed to the fixing piston 51 in a state in which the upper surface 56c of the sliding body 56 is in close contact with the lower surface of the horizontal stepped portion 51a of the fixing piston 51.

FIG. 12 is a perspective view of the fixed plate holder 52, and FIG. 13 is a perspective view of the main part of the fixed plate holder 52 with the sliding body 56 fitted thereto. As shown in the drawing, the fixed plate holder 52 is a cylindrical body having a predetermined length, and a plurality (in this embodiment, six at equal intervals) are arranged in the circumferential direction so as to extend and retract horizontally from the outer cylindrical portion 53 . Each of the fixed plate holders 52 has a holder hole 52c of a predetermined depth formed in the tip surface thereof, and penetrates the outer cylindrical portion 53 to face the outside. The rear end surface of the fixed plate holder 52 is formed as a holder slope 52a inclined toward the fixing piston 51 side, and continuous holder recesses 52b having the same slope as the holder slope 52a are formed on both sides thereof.

Therefore, as shown in FIG. 13, the sliding convex portion 56b of the sliding body 56 can be slidably brought into close contact with the holder concave portion 52b of the fixed plate holder 52, and the holder inclined surface 52a and the sliding inclined surface 56a are slidably brought into close contact. Since the sliding bodies 56 are fixed to the fixing piston 51 as described above, as shown in FIG. 15, a plurality of (six in this embodiment) sliding bodies 56 fixed to the fixing piston 51 are fitted with respective fixing plate holders 52 and protrude in the radial direction.

As a result, by supplying hydraulic oil to the fixing piston 51 and moving it downward, the upper surface 56c of the sliding body 56 is pushed down by the horizontal stepped portion 51a and acts on the holder inclined surface 52a of the fixed plate holder 52 which is in close contact with the sliding inclined surface 56a. The fixed plate holder 52 is supported by the outer cylindrical portion 53 so as not to move in the vertical direction, and the front end surface of the fixed plate holder 52 is open facing the outside from the outer cylindrical portion 53. Therefore, the fixed plate holder 52 extends in the radial direction, and the sliding slope 56a slides in the vertical direction along the holder slope 52a while being in close contact with the holder slope 52a. As a result, the fixing plate 55 fixed to the tip end surface of the fixing plate holder 52 also extends in the radial direction and presses against the inner wall of the casing 5. By maintaining this state, the underground hole drilling rig 1 is fixed to the casing 5.

On the other hand, from the state in which the fixing plate 55 is protruding and the underground hole drilling device 1 is fixed to the inner wall of the casing 5, the fixing piston 51 is discharged from the fixing piston 51 and moved upward, so that the fixing piston 51 and the sliding body 56 rise in the vertical direction. Due to this operation, the slide slope 56a and the holder slope 52a are fitted through the slide protrusion 56b and the holder recess 52b, respectively. As a result, the fixing plate 55 fixed to the tip surface of the fixing plate holder 52 is also contracted in the radial direction and stretched back, and is released from the inner wall of the casing 5, thereby releasing the underground hole drilling device 1 from the casing 5 and maintaining the state.

The extension/retraction operation of the fixing plate 55 will be described with reference to FIGS. 16 to 19. FIG. 16 is a cross-sectional view of the main part of the fixing part 50 when it is extended, FIG. 17 is a diagram illustrating the operation of the fixing plate 55 when it is extended, FIG. 18 is a cross-sectional view of the main part of the fixing part 50 when it is unrolled, and FIG. As shown in FIGS. 16 and 17, by supplying hydraulic oil to the fixing piston 51 to move it in the vertical direction and keep it in that state, the fixing plate holder 52 fitted to the sliding body 56 also protrudes in the radial direction as indicated by the arrow α. Since this fixing operation is performed by the movement of one fixing piston 51 consisting of a hollow annular body, the plurality of fixing plates 55 fixed to the plurality of fixing plate holders 52 are synchronously protruded, and the underground hole drilling rig 1 can be fixed to the inner wall of the casing 5 in a state in which the center is positioned on the center line of the casing 5 and kept horizontal. Therefore, the excavation bucket 10 equipped at the center of the tip of the underground hole excavator 1 suspended from the base machine 205 by the support rope 220 can be operated at the center of the excavation surface, and the optimum location can be efficiently excavated.

On the other hand, in order to separate the underground hole drilling rig 1 from the inner wall of the casing 5, as shown in FIGS. 18 and 19, the working oil is discharged from the fixing piston 51 to reduce the vertical direction, and this state is maintained. Therefore, the underground hole drilling device 1 suspended from the base machine 205 by the support ropes 220 can freely move up and down on the ground and inside the casing 5 . It should be noted that the hydraulic oil supply/discharge means and route may be appropriately selected from well-known configurations, and illustration in the description and each drawing is omitted. The same applies to the following description.

The upper end surface 35a of the drive shaft 35, which has a diameter smaller than that of the rotary disc 36, is fixed to the lower surface of the rotary disc 36 of the second support 30 by an appropriate means such as a connecting bolt 46, so that the drive shaft 35 passes through the fixing portion 50, specifically, the inner cylindrical portion 54, and hangs down in the vertical direction. Therefore, the rotational force output from the rotary hydraulic motor 31 is transmitted from the pinion gear 32 to the rotary gear 33, rotates the rotary gear 33 on the inner peripheral surface of the annular frame 34, and is transmitted to the drive shaft 35 via the rotating disk 36 connected to the rotary gear 33, causing the drive shaft 35 to rotate forward or backward with a predetermined rotational torque. An encoder 38 is installed to measure the number of revolutions of the drive shaft 35 .

As shown in FIGS. 20 and 21, the tip adjoining portion of the drive shaft 35 adjacent to the cylindrical circular tip portion 35b is formed into a hexagonal portion 35c having a hexagonal cross-section and protrudes from the inner cylindrical portion 54 of the fixing portion 50. As shown in FIGS. 22, an output joint 57 has a circular through hole 57a with a circular cross section and a hexagonal through hole 57b with a hexagonal cross section. The drive shaft 35 protruding from the inner cylindrical portion 54 is inserted into the continuous circular through hole 57 a and the hexagonal through hole 57 b, and the hexagonal portion 35 c having a hexagonal cross section formed adjacent to the tip of the drive shaft 35 is fitted into the hexagonal through hole 57 b having a hexagonal cross section, and the circular tip portion 35 b protrudes from the output joint 57 .

Reference numeral 58 denotes a cylinder joint which, as shown in FIG. 23, has a circular through hole 58a with a circular cross section on one side and a rectangular through hole 58b with a rectangular cross section on the other side. The drive shaft 35 protruding from the output joint 57 is inserted into the circular through-hole 58a and fixed by an appropriate means such as a connecting bolt 47. At the same time, the output joint flange 57c protruding from the end face of the output joint 57 on the hexagonal through-hole 57b side and the cylinder joint flange 58c protruding from the end face of the cylinder joint 58 on the circular through-hole 58a side are brought into close contact with each other and their peripheral surfaces are integrally fixed by appropriate means such as the connecting bolt 63. Therefore, the output joint 57 and the cylinder joint 58 also rotate integrally in conjunction with the rotation of the drive shaft 35 .

By connecting the cylinder tube 65 of the pressing hydraulic cylinder 60 to the cylinder joint 58 configured as described above, the cylinder tube 65 is rotated in conjunction with the rotation of the drive shaft 35 . 24A is a perspective view of the pressing hydraulic cylinder 60, FIG. 24B is a partial perspective view of the head side, and FIG. The cylinder tube 65 is formed in a hollow cylindrical shape, and the inner peripheral surface thereof has a circular cross section. The rod 70 can extend and contract from the cylinder tube 65 by supplying and discharging hydraulic oil into and from the cylinder tube 65 from a hydraulic port 69 formed in the head-side end portion 65a shown in FIG. 24(B). On the other hand, the outer peripheral surface 65b of the cylinder tube 65 is formed to have a rectangular cross section, and one of the features of the present invention is that the outer peripheral surface 65b is used to transmit the rotational force to the Kelly bar 80. FIG.

A head-side end portion 65a of the cylinder tube 65 shown in FIG. 24B has a cross-sectional shape that is smaller than the outer peripheral surface 65b of the other portion and has a stepped portion. As a result, the cylinder tube 65 of the pressing hydraulic cylinder 60 rotates in conjunction with the rotation of the drive shaft 35 . A rectangular parallelepiped rotational force transmission plate 66 having a predetermined thickness and area on each surface is fixed to the outer peripheral surface 65b of the cylinder tube 65 in the vicinity of the rod-side tip so as to protrude from the outer peripheral surface 65b.

A kelly bar 80 that transmits rotational force to the excavation bucket 10 is slidably fitted to the outer peripheral surface 65 b of the cylinder tube 65 and rotatably through the rotation of the cylinder tube 65 . That is, when the cylinder tube 65 rotates, the rotational force is transmitted to the inner peripheral surface 82 of the kelly bar 80 via the rotational force transmission plate 66 (see FIGS. 25 and 26). Therefore, as shown by arrow A in FIG. 27, the kelly bar 80 is rotationally driven at an arbitrary position sliding on the outer peripheral surface 65b of the cylinder tube 65 by the driving point 85 of the clockwise or counterclockwise rotational force transmitted from the drive shaft 35 through the rotational force transmission plate 66 of the cylinder tube 65.

As shown in FIGS. 25 and 26, the kelly bar 80 has an inner peripheral surface 82 with a rectangular cross section, and when fitted to the outer peripheral surface of the cylinder tube 65, the rotational force transmission plate 66 is in close contact with the inner peripheral surface 82, and rotates in conjunction with the rotation of the cylinder tube 65. 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 fitted to the cylinder tube 65, and a horizontally projecting Kelly bar flange 81a is formed on the outer periphery of the tip end of the enlarged diameter hat portion 81. 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. These kelly bar flange 81a, bearing case flange 90a, and tool joint flange 15a have the same diameter, and are brought into close contact with each other and integrally fixed by appropriate means such as 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 head 71 is connected to the tip of the rod 70 of the pressing hydraulic cylinder 60, and the rod head fixing pin 77 is inserted through the insertion hole 84 and fixed. The tip of the rod head 71 is inserted into the bearing case 90 and covered with a seal plate 91 for sealing. The rod 70 rotates in the same manner as the cylinder tube 65, but since there is a slight clearance between the rotational force transmission plate 66 of the cylinder tube 65 and the kelly bar 80, a time lag occurs before the rotation of the cylinder tube 65 is transmitted to the kelly bar 80. As described above, since the kelly bar flange 81a, the bearing case flange 90a, and the tool joint flange 15a are integrally fixed, the rod 70 of the pressing hydraulic cylinder 60 is supported on the tool joint 15 side. Therefore, by interposing the bearing 92 between the rod head 71 and the kelly bar 80, the bearing 92 rotates at the initial stage of rotation of the cylinder tube 65, thereby preventing the rod 70 from rotating due to the rotational difference between the cylinder tube 65 and the kelly bar 80.

The excavation bucket 10 has a hollow portion with a predetermined capacity, and has a bit 11a at its tip and is equipped with an opening/closing lid 11 that can be freely opened and closed with an opening/closing shaft 12 as a fulcrum. The construction of this excavation bucket 10 is known.

SUMMARY OF THE INVENTION An object of the present invention is to solve the problems of noise and vibration and to provide an underground hole drilling apparatus capable of drilling a smaller diameter underground hole than conventional ones. For this reason, focusing on the fact that there are no restrictions on the vertical dimension of the underground hole drilling device 1 that is detachably fixed to the inner wall of the casing 5, as a characteristic configuration, the drive shaft 35 and the kelly bar 80 are arranged in series on a vertical line to reduce the diameter. I decided to equip it. Therefore, the pressing hydraulic cylinder 60 exerts two functions of pressing the excavation bucket 10 against the excavation surface and rotating the cylinder tube 65 by the rotational force from the drive shaft 35, thereby transmitting the rotational force to the kelly bar 80 and rotationally driving the excavation bucket 10.

In this manner, the drive shaft 35 and the kelly bar 80 are arranged vertically in series, and the cylinder tube 65 of the pressing hydraulic cylinder 60 is rotated by the drive shaft 35 to transmit the rotational force to the kelly bar 80, which is a characteristic configuration of the present invention.

When the underground hole is excavated, the rod 70 of the pressing hydraulic cylinder 60 is moved to constantly press the excavating bucket 10 against the excavation surface while driving the rotating hydraulic motor 31 to decelerate its rotational force and transmit it to the drive shaft 35 to rotate the cylinder tube 65 of the pressing hydraulic cylinder 60 to rotate the kelly bar 80, thereby rotating the excavating bucket 10, excavating the earth and sand, and taking the excavated earth and sand into the excavating bucket 10.

According to the present invention described above, since the plurality of fixing plates fixed to the plurality of fixing plate holders are simultaneously expanded and retracted by moving one fixing piston in the vertical direction, the amount of protrusion and retraction of the fixing plates is equally controlled, and the plurality of fixing plates are synchronously extended and retracted. Therefore, the extension and retraction of a plurality of fixing plates are performed in synchronism, and it is possible to fix the underground hole drilling device to the inner wall of the casing in a state in which the center is always positioned on the center line of the casing and kept horizontal. Therefore, the excavating bucket mounted at the center of the tip of the underground hole drilling device can be operated at the center of the excavation surface, and the optimum location can be efficiently excavated.

In addition, since a dedicated fixing hydraulic cylinder is not required for each of the plurality of fixing plates, it is possible to reduce the influence of the extension and retraction of the fixing plates on the radial dimension of the underground hole drilling rig, which contributes to the drilling of small-diameter underground holes.

Furthermore, the kelly bar that transmits the torque to the excavation bucket and the drive shaft that transmits the torque of the hydraulic motor for rotation to the kelly bar are arranged in series on the same vertical line, so that the radial dimension of the underground hole drilling rig can be reduced. In addition, the pressing hydraulic cylinder has two functions of pressing the excavation bucket against the excavation surface and rotating the cylinder tube by the rotational force from the drive shaft, transmitting the rotational force to the kelly bar to drive the excavation bucket in rotation. Therefore, the torque can be transmitted from the drive shaft to the kelly bar via the cylinder tube of the pressing hydraulic cylinder, and the kelly bar can be extended and retracted in conjunction with the extension and retraction of the rod of the pressing hydraulic cylinder, thereby pressing the excavator against the excavation surface.

Therefore, as the use of cast-in-place piles becomes more versatile, an underground hole for driving a cast-in-place pile with a smaller diameter than a conventional pile diameter, for example, a diameter of about 1000 mm, which is smaller than a conventional pile diameter of about 1200 mm.

REFERENCE SIGNS LIST 1 underground hole drilling device 5 casing 5a bit 10 excavation bucket 11 open/close lid 11a bit 12 open/close shaft 15 tool joint 15a tool joint flange 20 first support 21 support bracket 22 post connection pin 26 suspension bracket 26a suspension hole 30 second support 31 hydraulic motor for rotation 32 pinion gear 33 rotary Gear 34 Annular frame 35 Drive shaft 35a Upper end surface 35b Circular tip 35c Hexagonal portion 36 Rotating disc 37 Joint tubular portion 38 Encoder 40 Post 41, 42, 43, 44, 45, 46, 47, 48, 49 Connection bolt 50 Fixing portion 51 Fixing piston 51a Horizontal step 51b Sliding body concave portion 52 Fixed plate holder 52a Holder slope 52b Holder concave portion 52c Holder hole 53 Outer cylindrical portion 54 Inner cylindrical portion 55 Fixed plate 56 Sliding body 56a Sliding slope 56b Sliding convex portion 56c Upper surface 57 Output joint 57a Circular through hole 57b Hexagonal through hole 57c Output joint flange 58 Cylinder 58a Circular through hole 58b Rectangular through hole Hole 58c... Cylinder joint flange 59... Hollow bottom lid portion 60... Hydraulic cylinder for pressing 63, 95... Connection bolt 65... Cylinder tube 65a... Head side end 65b... Outer peripheral surface 66... Torque force transmission plate 69... Hydraulic port 70... Rod 77... Rod head fixing pin 80... Kelly bar 81... Enlarged hat part 81a... Kelly bar flange 82... Inner 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

In order to solve the problem, according to claim 1, a plurality of fixing plates installed at predetermined intervals are radially extended and retracted to be detachably fixed to the inner wall of the casing, and the excavation bucket is rotated while being pressed against the excavation surface in the casing to excavate and take in the excavated earth and sand in the excavation bucket.Sliding slopes formed on a plurality of sliding bodies fixed to a fixing piston made of a hollow annular body are slidably fitted to holder slopes formed on a rear end surface of a fixing plate holder consisting of a plurality of cylindrical bodies having a fixing plate fixed to a front end face thereof, and in conjunction with the vertical movement of the fixing piston, the sliding bodies slide vertically along the holder slopes, and the fixing plate holder expands and contracts in the radial direction.Extending and retracting multiple fixing platesofThe underground hole drilling rig in simultaneous all-casing construction method is provided on the basis.

According to claim 2, there is provided a configuration in which a plurality of fixing plates are circumferentially arranged at regular intervals .

Further, according to claim 3 , there is provided a configuration in which the lower surface of the horizontal stepped portion formed in the intermediate portion of the fixing piston is brought into close contact with the upper surface of the sliding body, according to claim 4 , there is provided a configuration in which sliding projections formed on both sides of the sliding slope are fitted into holder recesses formed on both sides of the holder slope, and according to claim 5 , there is provided a configuration in which a plurality of fixing plates are synchronously extended and retracted.

Further, according to claim 6 , the cylinder tube of the pressing hydraulic cylinder that presses the excavation bucket can be rotated by the rotating hydraulic motor, and a kelly bar that transmits rotational force to the excavation bucket is slidably fitted to the outer peripheral surface of the cylinder tube and rotatably interlocked with the rotation of the cylinder tube.

According to claim 7 , the first support and the second support are separated by a predetermined distance and connected by a support column, a drive shaft that is rotatably driven by a rotary hydraulic motor arranged on the second support is vertically provided from the lower surface of the second support, a cylinder tube of a pressing hydraulic cylinder that presses the excavation bucket is rotatably connected to the tip of the drive shaft in conjunction with the rotation of the drive shaft, and a kelly bar that is connected to the excavation bucket is slidably and rotatably fitted to the outer peripheral surface of the cylinder tube in conjunction with the cylinder tube. provide.

and claims8The hollow annular outer cylinder is fixed to the outer circumference of the lower surface of the second support, and the hollow annular inner cylinder is fixed to the inner circumference of the lower surface of the second support.death,The lower surface of the outer cylinder part and the lower surface of the inner cylinder part are covered with a hollow bottom lid part, and a fixing piston movable in the vertical direction by hydraulic pressure is provided in a space surrounded by the outer cylinder part, the inner cylinder part and the hollow bottom lid part, and claiming9provides a configuration in which the rotational force transmission surface consisting of the outer peripheral surface of the cylinder tube and the inner peripheral surface of the Kelly bar is rectangular, and claim10provides a configuration in which the rotational force of the hydraulic motor for rotation is transmitted to the cylinder tube via the drive shaft and transmitted from the outer peripheral surface of the cylinder tube to the excavation bucket via the inner peripheral surface of the kelly bar.

Further, according to claim 11 , there is provided a configuration in which a torque transmission plate for transmitting torque to the inner peripheral surface of the kelly bar is attached to the outer peripheral surface of the cylinder tube, according to claim 12 , there is provided a configuration in which the rod of the pressing hydraulic cylinder is connected to the tip of the kelly bar, and according to claim 13 , by fixing the tip of the kelly bar to a tool joint to which an excavation bucket is joined, the kelly bar can be expanded and contracted in conjunction with the expansion and contraction of the pressing hydraulic cylinder by the expansion and contraction of the pressure hydraulic cylinder. do. Furthermore, according to claim 14 , there is provided a configuration in which the kelly bar slides on the outer peripheral surface of the cylinder tube as the kelly bar expands and contracts.

According to the present invention described above, a plurality of fixing plates fixed to a plurality of fixing plate holders are simultaneously extended and retracted by moving one fixing piston composed of a hollow annular body in the vertical direction. Therefore, the extension and retraction of a plurality of fixing plates are performed in synchronism, so that the center of the underground hole drilling rig can always be positioned on the center line of the casing and fixed to the inner wall of the casing in a horizontal state. Therefore, the excavating bucket mounted at the center of the tip of the underground hole drilling device can be operated at the center of the excavation surface, and the optimum location can be efficiently excavated.

According to the present invention described above, since the plurality of fixing plates fixed to the plurality of fixing plate holders are simultaneously extended and retracted by moving one fixing piston formed of a hollow annular body in the vertical direction, the amount of protrusion and retraction of the fixing plates is equally controlled, and the plurality of fixing plates are synchronously extended and retracted. Therefore, the extension and retraction of a plurality of fixing plates are performed in synchronism, and it is possible to fix the underground hole drilling device to the inner wall of the casing in a state in which the center is always positioned on the center line of the casing and kept horizontal. Therefore, the excavating bucket mounted at the center of the tip of the underground hole drilling device can be operated at the center of the excavation surface, and the optimum location can be efficiently excavated.

Claims (17)

A underground hole drilling apparatus in an all-casing construction method in which a plurality of fixing plates are radially extended and retracted at predetermined intervals to be detachably fixed to the inner wall of a casing, and an excavation bucket is pressed against an excavation surface in the casing and rotated to excavate, and the earth and sand excavated into the excavation bucket are taken into the excavation bucket,
An underground hole drilling apparatus in an all-casing construction method characterized in that the extension and retraction of a plurality of fixing plates are simultaneously performed by moving one fixing piston in the vertical direction. 2. The underground hole drilling apparatus in the all-casing construction method according to claim 1, wherein a plurality of fixing plates are circumferentially arranged at regular intervals. Sliding slopes formed on a plurality of sliding bodies fixed to a fixing piston consisting of a hollow annular body,
slidably fitted to the holder slope formed on the rear end surface of the fixed plate holder composed of a plurality of cylindrical bodies with the fixed plate fixed to the front end surface;
In conjunction with the vertical movement of the fixing piston, the sliding body slides vertically along the oblique surface of the holder, causing the fixing plate holder to expand and contract in the radial direction.
3. The underground hole drilling apparatus in the all-casing construction method according to claim 1 or 2, wherein the fixing plate is extended and retracted. 4. The underground hole drilling apparatus in the all-casing construction method according to claim 3, wherein the lower surface of the horizontal step formed in the intermediate portion of the fixing piston is in close contact with the upper surface of the sliding member. 5. The underground hole excavating apparatus according to claim 3 or 4, wherein the slide projections formed on both sides of the sliding slope are fitted into the holder recesses formed on both sides of the holder slope. 6. An underground hole drilling apparatus in an all-casing construction method according to claim 3, 4 or 5, wherein the extension and retraction of a plurality of fixing plates are performed synchronously. The underground hole excavating apparatus according to claim 3, 4, 5, or 6, wherein a cylinder tube of a pressing hydraulic cylinder for pressing the excavation bucket is rotatable by a rotating hydraulic motor, and a kelly bar for transmitting rotational force to the excavation bucket is slidably fitted to the outer peripheral surface of the cylinder tube and rotatably interlocked with the rotation of the cylinder tube. 8. The underground hole drilling apparatus in the all-casing construction method according to claim 3, 4, 5, 6, or 7, wherein the fixed plate holder penetrates the outer cylindrical portion and is radially expandable. 9. The underground hole drilling apparatus in the all-casing construction method according to claim 8, wherein the fixed plate can be extended outwardly and retracted from the outer cylindrical portion. The first support and the second support are separated by a predetermined distance and connected with a support,
a drive shaft driven to rotate by a hydraulic motor for rotation arranged on the second support is provided vertically from the lower surface of the second support;
A cylinder tube of a pressing hydraulic cylinder for pressing the excavation bucket is rotatably connected to the tip of the drive shaft in conjunction with the rotation of the drive shaft,
10. The underground hole drilling apparatus according to claim 3, 4, 5, 6, 7, 8 or 9, wherein a kelly bar connected to the excavation bucket is slidably fitted to the outer peripheral surface of the cylinder tube and rotatably interlocked with the cylinder tube. A hollow annular outer cylinder is fixed to the outer circumference of the lower surface of the second support, and a hollow annular inner cylinder is fixed to the inner circumference of the lower surface of the second support, and the lower surface of the outer cylinder and the lower surface of the inner cylinder are covered with a hollow bottom cover,
11. The underground hole drilling apparatus in the all-casing construction method according to claim 10, wherein a fixing piston movable in the vertical direction by hydraulic pressure is provided in the space surrounded by the outer cylindrical portion, the inner cylindrical portion and the hollow bottom cover portion. 12. The underground hole drilling apparatus according to claim 10 or 11, wherein the rotational force transmission surface comprising the outer peripheral surface of the cylinder tube and the inner peripheral surface of the kelly bar is rectangular. 13. The underground hole drilling apparatus in the all-casing construction method according to claim 10, 11 or 12, wherein the rotational force of the rotary hydraulic motor is transmitted to the cylinder tube through the drive shaft and transmitted from the outer peripheral surface of the cylinder tube to the excavating bucket through the inner peripheral surface of the kelly bar. 14. The underground hole drilling apparatus in the all-casing construction method according to claim 10, 11, 12 or 13, wherein a rotational force transmission plate for transmitting rotational force to the inner peripheral surface of the kelly bar is attached to the outer peripheral surface of the cylinder tube. 15. The underground hole drilling apparatus in the all-casing construction method according to claim 10, 11, 12, 13 or 14, wherein the rod of the pressing hydraulic cylinder is connected to the tip of the kelly bar. 16. The underground hole drilling apparatus in the all-casing construction method according to claim 10, 11, 12, 13, 14, or 15, wherein the tip of the kelly bar is fixed to a tool joint to which the excavation bucket is joined, so that the kelly bar can be expanded and contracted in conjunction with the expansion and contraction of the hydraulic pressure cylinder by the expansion and contraction of the hydraulic pressure cylinder. 17. The underground hole drilling apparatus according to claim 10, 11, 12, 13, 14, 15 or 16, wherein the kelly bar slides on the outer peripheral surface of the cylinder tube as the kelly bar expands and contracts.

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