JP6099955B2 - Nakabori excavator - Google Patents

Description

  The present invention is attached to the inside of an excavation casing used in an all-casing method for constructing cast-in-place piles after removing obstacles such as reinforced concrete structures buried in the ground. The present invention relates to an intermediate excavator used for expanding the bottom of a non-enclosed vertical hole or excavating the ground in an excavation casing. It can be installed at a position and excavation work can be performed at that position, while the torque can be increased and the number of rotations can be improved, and the excavation time can be shortened so that the bottom can be expanded on hard ground, the large diameter can be expanded, and rock can be excavated This is related to the Nakabori excavator.

  In recent years, with the redevelopment of cities and the aging of reinforced concrete structures, the rebuilding of structures has become frequent.

  By the way, when rebuilding this structure, in order to construct a pile according to the newly constructed structure, after removing obstacles such as reinforced concrete structures and existing piles buried in the ground, cast-in-place piles We are going to do the construction of.

  Conventionally, for the removal of obstacles buried in the ground and the construction of cast-in-place piles, an all-casing method that can construct high-quality piles regardless of the properties of the ground has been used (for example, non-patent literature) 1).

  That is, in the all casing method, while a cylindrical excavation casing is rotated or rocked and pressed into the ground, the earth and sand in the excavation casing is excavated and discharged with a hammer grab to excavate a vertical hole. After reaching the depth of the ground, after drilling the bottom of the hole, construct a pile by building a reinforcing steel cage, driving concrete with treme, and pulling out and collecting the excavation casing and treme as the concrete is driven Is the method.

  Moreover, in this all casing construction method, when making the support capacity of a pile larger, the bottom-expanded pile which formed the expanded bottom part expanded rather than the axial part in the part used as the bottom part of a pile is made | formed. In this case, the bottom expansion bucket inserted into the excavation casing is rotated by an earth drill machine, and the circumference of the bottom portion of the vertical hole is excavated to expand the diameter.

  However, when constructing an expanded bottom pile with an expanded diameter at the bottom of the pile, the all-casing method and earth drill method are used in combination, and in addition to the all-round rotary excavator and crawler crane used for the all-casing method, A drilling machine, a large mud plant, etc. were required, and there was a problem that the facilities were large.

  In addition, if the site of the construction site is small, not all equipment and materials can be placed on the site of the construction site, so the construction work must be performed separately from the obstacle removal process and pile construction process in the ground. There has been a problem that the number of process days is increased because it is necessary to backfill and re-drill the drilled hole.

  Furthermore, since the bottom expansion bucket attached to the earth drill machine is rotated through the kelly bar, it cannot be expected to have much strength, and the torque cannot be greatly increased, so that it takes a considerable time for excavation. There was a problem. In particular, in the case of strong ground, excavation might not be possible.

All casing expanded pile construction method in the Futaba Materials Co., Ltd. homepage, [searched on November 28, 2012], Internet <URL: http://www.futaba-311p.com/construction/sy_all.html

  The present invention has been made in view of such problems. The purpose of the present invention is to mount the Nakabori excavator at an arbitrary position inside the casing for excavation and perform excavation work at that position. It is an object of the present invention to provide an intermediate excavator capable of increasing the number of revolutions and improving the rotation speed, shortening excavation time, and capable of expanding a bottom in a hard ground, expanding a large diameter, and excavating a rock.

In order to achieve the above object, the invention according to claim 1 of the present invention is configured to press-fit the excavation casing into the ground while rotating or swinging the excavation casing and excavate and discharge the earth and sand in the excavation casing. An intermediate excavator to be mounted inside the excavation casing used in the all casing method for excavating the vertical hole, the intermediate excavator being detachably fixed to the inner side of the excavation casing. And a widening bucket that is linked to the driving device and expands the bottom of the vertical hole that is not surrounded by the excavating casing. The driving device includes a drum-shaped casing body and a center of the casing body. rotatable been and vertically movably disposed in a vertical posture in part, a driving shaft to a lower end 拡底bucket is connected, provided in the casing main body, the rotary drive unit for rotating the drive shaft A feeder device that is provided on the casing body and moves the drive shaft up and down; and a chuck device that is provided on the casing body and presses the inner wall surface of the excavation casing to fix the intermediate excavator itself to the inner wall surface of the excavation casing On the other hand, the bottom expansion bucket includes a cylindrical main body having a plurality of openings in the peripheral wall, an annular stabilizer provided at the upper end of the main body, a bottom lid provided at the lower end of the main body, and a main body And a transmission shaft that is detachably connected to the drive shaft of the drive device, and one side edge is rotatably connected to one side edge of the opening of the main body, and is connected to the other side edge. A plurality of widening blades provided with a plurality of excavation bits to open and close the opening of the main body, a closed position where each widening blade closes to the opening of the main body, and an open position where each widening blade opens the opening of the main body Widening wings A plurality of open / close hydraulic cylinders that swing freely openable and closable in the radial direction of the body, and provided with guide rods that slide and guide the inside of the excavation casing when the widened bucket is pulled up on the outer surface of each of the widening blades. It was in particular is characterized.

  According to a second aspect of the present invention, in the first aspect of the present invention, the rotational drive unit includes a plurality of hydraulic motors, an output shaft of each hydraulic motor coupled to the drive shaft, and an output shaft. And a gear reducer that transmits the rotation of the motor to the drive shaft.

  According to a third aspect of the present invention, there is provided a plurality of feeders according to the first aspect, wherein the feeder device is disposed around the drive shaft at equal angles and fixed to the casing body in a vertical posture. The lifting / lowering hydraulic cylinder is disposed at a position below the driving shaft, the driving shaft is rotatably supported, and a lifting / lowering plate to which the rod of the lifting / lowering hydraulic cylinder is connected. It is characterized in that the drive shaft moves up and down via the lifting plate as it expands and contracts.

  According to a fourth aspect of the present invention, in the first aspect of the present invention, the chuck device is disposed on the casing body so as to be reciprocally movable at equal angles and in the radial direction, and the inner surface is formed as an inclined surface. A plurality of chuck members formed with curved surfaces whose outer surfaces are in close contact with the inner wall surface of the excavation casing, a plurality of wedge bodies having inclined surfaces slidable on the inclined surfaces of the chuck members, and a casing body The chuck member is arranged at equal angles and moves up and down each wedge body. Each chuck member reciprocates in the radial direction of the casing body through each wedge body as the chuck cylinder expands and contracts. It is characterized by a configuration that moves.

  The invention of claim 5 of the present invention is characterized in that, in the invention of claim 4, a liner is detachably provided on the outer surface of the chuck member.

The Nakahori excavator of the present invention comprises a drive device that is detachably fixed to the inside of the excavation casing, and a bottom expansion bucket that is linked to the drive device. The drive device includes a drum-shaped casing body, a casing A driving shaft which is disposed in a vertical position at a central portion of the main body so as to be rotatable and movable up and down, and a bottom expansion bucket is connected to a lower end portion ; a rotation driving portion which is provided in the casing main body and which rotationally drives the driving shaft; A feeder device that is provided on the casing body and moves the drive shaft up and down; and a chuck device that is provided on the casing body and presses the inner wall surface of the excavating casing to fix the intermediate excavator itself to the inner wall surface of the excavating casing; It includes a drive device is fixed at an arbitrary position on the inside of the drill casing, to drill by rotating the 拡底bucket by a drive device Because you are done, it is possible to achieve excellent effects as follows.

(1) Since the Nakabori excavator of the present invention can perform excavation work with the excavator casing mounted inside, the installation space for the excavator on the ground is not required, and muddy water mixed with bentonite (stable The amount of liquid) can be reduced, and the mud plant can be reduced compared to the mud plant used in the earth drill method.
(2) The Nakabori excavator of the present invention can be mounted at any position on the excavating casing because the drive device includes the chuck device.
(3) The Nakabori excavator of the present invention includes a rotary drive unit and a feeder device, so that the excavation work is performed even when the crawler crane is separated from the crawler crane when the drive device is mounted inside the excavation casing. Can be done.
(4) In the Nakabori excavator of the present invention, the bottom expansion bucket is directly attached to the drive shaft of the drive device, and the drive shaft is rotationally driven by the rotation drive portion of the drive device. As a result, the excavation time can be shortened, and the bottom can be expanded on hard ground, can be expanded to a large diameter, and rock can be excavated.
(5) Since the Nakabori excavator of the present invention attaches the bottom expansion bucket directly to the drive shaft of the drive device and does not use a kelly bar , the attachment portion of the bottom expansion bucket to the drive device becomes strong, and the torque and rotation speed Raising the value will not cause any problems.
(6) The Nakabori excavator of the present invention includes a feeder device that moves the drive shaft up and down, so that excavation can be performed with an appropriate pressure without relying on the press-fitting of the all-around rotary excavator.
(7) In the Nakabori excavator of the present invention, since the drive device is provided with a wedge-shaped chuck device, it can be securely and firmly fixed to the inner wall surface of the excavation casing, and a large reaction force can be obtained. Even if the number of rotations is increased, the excavation casing does not fall off.
(8) Since the Nakabori excavator of the present invention has a configuration in which the liner is detachably provided on the chuck member of the chuck device, the excavator can accommodate several types of excavation casings having different diameters.

It is a front view of the Nakabori excavator in the state where the Nakabori excavator according to the embodiment of the present invention is mounted in the excavation casing and the bottom expansion bucket is closed. It is a front view of the Nakabori excavator in a state where the bottomed bucket is also opened. It is a partially omitted front view of the drive device of the Nakabori excavator. It is a top view of a drive device. It is a bottom view of a drive device. It is a partially-omission front view of the state which the feeder apparatus of the drive device act | operated. It is a partially omitted side view of the state in which the feeder device of the drive device is activated. FIG. 4 is a sectional view taken along line AA in FIG. 3. FIG. 4 is a sectional view taken along line BB in FIG. 3. It is a front view of the state where the bottom expansion bucket of the Nakabori excavator is shown and the bottom expansion bucket is closed. It is a front view in the state where the bottom expansion bucket was opened. It is a cross-sectional view of an expanded bottom bucket. It is a front view of the Nakabori excavator in a state where the auger excavator according to another embodiment of the present invention is shown, the auger is attached to the drive device and the auger is mounted in the excavation casing. FIG. 11 is a front view of the Nakahori excavator in a state where a drilling excavator according to still another embodiment of the present invention is shown, a drilling bucket is attached to a drive device, and the drilling bucket is mounted in a casing for excavation.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIGS. 1-12 shows the Nakahori excavator 1 according to the embodiment of the present invention. The Nakahori excavator 1 is mounted inside the excavating casing 4 used in the all casing construction method. It is used to expand the diameter of the bottom of the vertical hole that is not enclosed. The drive device 2 is detachably fixed to the inside of the excavation casing 4, and is linked to the drive device 2. It is comprised from the bottom expansion bucket 3 which expands the diameter of the bottom part of the vertical hole which is not enclosed in a truncated cone shape.

  The excavating casing 4 includes a lower casing having a plurality of excavating bits at the lower end and a plurality of additional casings sequentially connected to the upper end of the lower casing. It is rotationally press-fitted into the ground or rocked and pressed into the ground by a rocking excavator (not shown).

  As shown in FIGS. 1 to 3, the driving device 2 is arranged in a drum-like casing main body 5 and in a central portion of the casing main body so as to be rotatable and movable up and down in a vertical posture, and a bottom expansion bucket 3 is connected to a lower end portion. A driving shaft 6 that is provided, a rotational drive unit 7 that is provided on the casing body 5 and rotationally drives the driving shaft 6, a feeder device 8 that is provided on the casing body 5 and moves the driving shaft 6 up and down, and a casing A chuck device 9 is provided on the main body 5 and presses the inner wall surface of the excavation casing 4 to fix the intermediate excavator 1 itself to the inner wall surface of the excavation casing 4.

  Specifically, as shown in FIGS. 6 to 8, the casing body 5 is formed in a drum shape having flanges at the upper and lower ends, and has a cylindrical body 5 a and an upper portion fixed to the upper end of the body 5 a. A flange 5b, a lower flange 5c fixed to the lower end of the main body 5a, a cylindrical skirt portion 5d fixed to the lower end of the outer peripheral edge of the upper flange 5b, and a plurality of reinforcements disposed and fixed on the outer peripheral surface of the main body 5a And plate 5e.

As shown in FIG. 3, the drive shaft 6 is formed in a cylindrical shape, and a plurality of keys 6 a are provided at equal angles on the outer peripheral surface of the upper end portion. A fitting hole 6b is provided which is detachably fitted in a state where the upper end portion of the transmission shaft 14 of the bucket 3 is prevented from rotating and is prevented from being detached by a pin.
The drive shaft 6 is disposed at the center position of the casing body 5, and the lower end portion thereof is rotatably supported by the center portion of the lifting plate 8 b of the feeder device 8 via the bearing device 10, and together with the lifting plate 8 b. It is designed to move up and down.

As shown in FIGS. 3 and 4, the rotation drive unit 7 includes four hydraulic motors 7 ′, the output shafts of the respective hydraulic motors 7 ′, and the drive shaft 6, which are coupled to each other to rotate the output shaft. And a gear reducer 7 ″ that transmits to 6.
Each hydraulic motor 7 'is arranged and fixed at a 90 degree angular interval on a circular gear case 7a of the gear reducer 7 ", and its output shaft is arranged in four pieces in the gear case 7a of the gear reducer 7". Are respectively fitted and fixed to the drive gear 7b.
The gear reducer 7 ″ is fixed to the upper flange 5b of the casing body 5, and includes four drive gears 7b and one driven gear 7c that meshes with each drive gear 7b inside the gear case 7a. In the central portion of the driven gear 7c of the gear reducer 7 ″, a portion provided with the key 6a of the drive shaft 6 is inserted and supported so as to be slidable in the axial direction and not relatively rotatable. Therefore, when the driven gear 7c is rotated by the driving gear 7b, the driving shaft 6 is rotated.

As shown in FIG. 6, the feeder device 8 is arranged around the drive shaft 6 at an angular interval of 180 degrees and is fixed to the lower flange 5 c of the casing body 5 in a vertical posture in two vertical lifting hydraulic cylinders 8 a. And an elevating plate 8b provided at the lower end of the driving shaft 6 and connected to the rod of the elevating hydraulic cylinder 8a via a bracket 8c. When the elevating hydraulic cylinder 8a expands and contracts, the driving shaft 6 is It moves up and down via the lift plate 8b.
Further, as shown in FIG. 7, the lifting plate 8b of the feeder device 8 includes a guide pipe 8d provided at a lower flange 5c of the casing body 5 at an angular interval of 180 degrees, and an angular interval of 180 degrees at the outer edge of the lifting plate 8b. And is moved up and down in a state of being prevented from rotating by a cylindrical guide shaft 8e slidably inserted into and supported by the guide pipe 8d.

3 and 8, the chuck device 9 is disposed in the skirt portion 5d of the casing body 5 so as to be reciprocally movable in the radial direction at an angular interval of 90 degrees, and an inclined surface whose inner surface extends downward. And four chuck members 9a formed on the curved surface whose outer surface is in close contact with the inner wall surface of the excavation casing 4, and inclined surfaces slidable on the inclined surfaces of the chuck members 9a (the outer surface is upward). Four wedge bodies 9b having sloping surfaces narrowing toward the bottom, and four vertical postures supported by the lower flange 5c of the casing body 5 via a bracket 9d and connected to the wedge body 9b to move the wedge body 9b up and down. When the chuck cylinder 9c is extended, the wedge body 9b is lifted, and each chuck member 9a is moved radially outward of the casing body 5 by the wedge action of the wedge body 9b. Each chuck member 9a is pressed against the inner wall surface of the excavating casing 4 to fix the intermediate excavator 1 itself to the inner wall surface of the excavating casing 4, and when the chuck cylinder 9c is shortened, the wedge body 9b is lowered. Then, the pressure contact state of the chuck member 9 a is released, and the Nakabori excavator 1 itself can move in the vertical direction within the excavation casing 4.
Further, arc-shaped liners 9e are detachably attached to the outer surfaces of the respective chuck members 9a as shown by a one-dot chain line in FIG. By attaching the liner 9e to the chuck member 9a, several types of excavation casings 4 having different diameters can be handled.

  Table 1 below shows the specifications of the drive device 2 described above.

  On the other hand, as shown in FIGS. 10 to 12, the widened bucket 3 includes a cylindrical main body 11 having two openings 11 a in the peripheral wall, an annular stabilizer 12 provided at the upper end of the main body 11, and a main body 11. A bottom cover 13 provided at the lower end of the main body 11, a transmission shaft 14 which is disposed at the center of the main body 11 and is detachably connected to the driving shaft 6 of the driving device 2, and one side edge is an opening of the main body 11. Two widening blades 15 that are pivotally connected to one side edge of the portion 11a and that are provided with a plurality of excavation bits 15a on the other side edge to open and close the opening 11a of the main body 11, and the main body 11 and each widening width A closed position (a one-dot chain line position in FIG. 12) where each widening blade 15 closes the opening 11 a of the main body 11 and an open position where each widening blade 15 opens the opening 11 a of the main body 11. (Wide line position in FIG. 12) And two open / close hydraulic cylinders 16 that swing freely open and close in the radial direction of the main body 11, and the widening blade 15 is moved by the extension of the open / close hydraulic cylinder 16 while rotating by the driving device 2. The diameter of the bottom of the vertical hole is increased by excavating the earth and sand while expanding the diameter, and by pulling up the excavated earth and sand while accommodating the inside of the main body 11 by reducing the diameter of the widening blade 15 by shortening the opening and closing hydraulic cylinder 16. Is.

Specifically, the main body 11 is formed in a cylindrical shape, and two openings 11a are formed on the peripheral wall of the main body 11 with an angular interval of 180 degrees.
The opening 11a has a substantially triangular shape with a width extending toward the lower end of the main body 11. One side edge of the opening 11a is parallel to the axis of the main body 11, and the other side of the opening 11a. The edge is inclined.
In addition, two reinforcing inner walls 17 and four reinforcing frames 18 for connecting and fixing the two reinforcing inner walls 17 are provided inside the main body 11.
Further, an annular stabilizer 12 having an outer diameter that is slightly smaller than the inner diameter of the excavation casing 4 is attached to the upper end portion of the main body 11, and a disc on which the excavated earth and sand are placed on the lower end portion of the main body 11. A shaped bottom lid 13 is provided.

The transmission shaft 14 is disposed at the center position of the main body 11, the upper end portion is fixedly supported on the inner surface of the stabilizer 12 via four beam members 25, and the lower end portion is a reinforcement in the main body 11. The frame 18 is fixed.
A fitting shaft 14a is provided at the upper end of the transmission shaft 14 so as to be detachably fitted in a state of being prevented from turning around the fitting hole 6b of the driving shaft 6 and to be prevented from coming off by a pin.

The two widened blades 15 are curved arc-shaped plates having substantially the same curvature as the main body 11, and are formed in a shape similar to the shape of the opening 11 a of the main body 11 as a whole.
That is, the two widened wings 15 are formed in a substantially triangular shape with one side edge parallel to the axis of the main body 11 and the other side edge inclined, with the width expanding toward the lower end. ing.
In addition, each widening blade 15 has one side edge parallel to the axis of the main body 11 at one side edge (one side edge parallel to the axis of the main body 10) of the opening 11 a of the main body 11 by the hinge 19. The opening 11a of the main body 11 can be opened and closed.
Further, excavation bits 15 a are provided at regular intervals on the inclined other side edges of the widening blades 15, and excavation is performed on the outer surface of the widening blades 15 when the bottom expansion bucket 3 is pulled up. A guide bar 20 that slides and guides the inside of the casing 4 is provided along the longitudinal direction of the widened blade 15.

  The open / close hydraulic cylinder 16 has one end connected to a bracket 21 provided on the reinforcing frame 18 of the main body 11 via a universal joint (not shown), and the other end connected to the inner surface of the lower end of the widening blade 15. When the opening / closing hydraulic cylinder 16 is shortened, the widening blade 15 rotates to the main body 11 side to close the opening 11a of the main body 11, and is connected to the provided bracket 22 via a universal joint (not shown). Further, when the opening / closing hydraulic cylinder 16 is extended, the widening blade 15 is rotated outwardly of the main body 11 to open the opening 11 a of the main body 11.

  Next, the case where a bottom expansion part is formed in the bottom part of the vertical hole formed with the casing 4 for excavation using the above-mentioned Nakabori excavator 1 is demonstrated.

  First, excavating the earth and sand in the excavating casing 4 with a hammer grab suspended by a crawler crane while excavating and excavating the excavating casing 4 into the ground by an all-round rotary excavator installed on the ground, Subsequently, the excavating casing 4 is press-fitted to a depth necessary for the construction of the expanded pile while sequentially connecting the additional casings, and a vertical hole having the same diameter as the excavating casing 4 is excavated.

  Next, the excavating casing 4 is pulled up by a predetermined length (approximately the same length as the height of the widening blade 15) by an all-round rotary excavator, and muddy water mixed with bentonite or the like to prevent the bottom of the vertical hole from collapsing (stable Pour liquid) into the bottom of the vertical hole. At this time, the muddy water only needs to be filled in the bottom of the vertical hole in which the excavating casing 4 is pulled up, so that the muddy water plant can be reduced.

  Then, the intermediate excavator 1 with the bottom expansion bucket 3 closed by the crawler crane is suspended and inserted into the excavating casing 4, and the chuck device 9 of the driving device 2 is operated to move the tip of the excavating casing 4 inward. Fix it. At this time, the mounting position of the Nakabori excavator 1 to the excavation casing 4 is set so that the entire widening blade 15 of the bottom expansion bucket 3 is located in the bottom of the vertical hole not surrounded by the excavation casing 4.

  Thereafter, while rotating the bottom expansion bucket 3 by the rotation drive unit 7, the widening blade 15 of the bottom expansion bucket 3 is gradually expanded by the opening / closing hydraulic cylinder 16 and the bottom inner periphery of the vertical hole not surrounded by the excavation casing 4 The ground of the surface is excavated by the excavation bit 15a of the widening wing 15 to form a truncated conical expanded bottom space at the bottom of the vertical hole.

  The excavated earth and sand are taken into the main body 11 along the inner surface of the widening blade 15. The earth and sand taken into the main body 11 is discharged to the ground without spilling by lifting the Nakabori excavator 1 to the ground with the bottom expansion bucket 3 closed.

Since the Nakabori excavator 1 is mounted and fixed inside the excavating casing 4 and includes the drive device 2 that rotationally drives the bottom expansion bucket 3, it is possible to increase the torque and improve the rotational speed. The excavation time can be shortened, and the bottom can be expanded on hard ground, large-diameter, and rock excavation. Moreover, since the Nakabori excavator 1 directly attaches the widened bucket 3 to the drive shaft 6 of the drive device 2 and does not use a kelly bar, the attachment portion of the widened bucket 3 to the drive device 2 becomes stronger, torque and Even if the number of revolutions is increased, no problem occurs.
Further, since the driving device 2 includes the chuck device 9 and the rotation driving unit 7, the Nakabori excavator 1 can be mounted at an arbitrary position of the excavating casing 4 and is separated from the crawler crane. However, excavation work can be performed by the rotation drive unit 7 and the bottomed bucket 3.
Further, the Nakabori excavator 1 can be securely and firmly fixed to the inner wall surface of the excavating casing 4 because the drive device 2 includes the wedge-shaped chuck device 9, and even if the torque and the number of rotations are increased. It does not fall off from the excavation casing 4.

  In the above embodiment, the bottomed bucket 3 is attached to the driving shaft 6 of the driving device 2, but in other embodiments, as shown in FIGS. The auger 23 or the drilling bucket 24 may be detachably attached to the drive shaft 6 of the drive device 2.

  The Nakabori excavator 1 shown in FIGS. 13 and 14 is used for excavating the ground in the excavating casing 4. The auger 23 or the drilling bucket 24 is rotated by the rotation drive unit 7, and the auger 23 is rotated by the feeder device 8. 23 or drilling bucket 24 is pressed into the ground in the excavating casing 4 to excavate the ground.

The Nakabori excavator 1 shown in FIGS. 13 and 14 can also achieve the same operational effects as the Nakabori excavator 1 shown in FIG.
Further, since the Nakabori excavator 1 includes the feeder device 8 in which the drive device 2 moves the drive shaft 6 up and down, excavation can be performed at an appropriate pressure without relying on the press-fitting of the all-around rotary excavator. .

DESCRIPTION OF SYMBOLS 1 is Nakabori excavator, 2 is a drive device, 3 is a bottom expansion bucket, 4 is a casing for excavation, 5 is a casing main body, 5a is a cylindrical main body, 5b is an upper flange, 5c is a lower flange, 5d is a skirt portion, 5e Is a reinforcing plate, 6 is a drive shaft, 6a is a key, 6b is a fitting hole, 7 is a rotary drive unit, 7 'is a hydraulic motor, 7 "is a gear reducer, 7a is a gear case, 7b is a drive gear, 7c is The driven gear, 8 is a feeder device, 8a is a lifting hydraulic cylinder, 8b is a lifting plate, 8c is a bracket, 8d is a guide pipe, 8e is a guide shaft, 9 is a chuck device, 9a is a chuck member 9b is a wedge body, 9c is Chuck cylinder, 9d is a bracket, 9e is a liner, 10 is a bearing device, 11 is a main body, 11a is an opening, 12 is a stabilizer, 13 is a bottom cover, 14 is a transmission shaft, 14a is a fitting shaft, Is a widening wing, 15a is a drilling bit, 16 is a hydraulic cylinder for opening and closing, 17 is a reinforcing inner wall, 18 is a reinforcing frame, 19 is a hinge, 20 is a guide rod, 21 is a bracket, 22 is a bracket, 23 is an auger, 24 Is a drilling bucket, 25 is a beam member.

Claims (5)

An all-casing method in which the excavating casing (4) is pressed into the ground while rotating or swinging, and the sediment in the excavating casing (4) that has been pressed into the ground is excavated and discharged to excavate a vertical hole. Nakabori excavator (1) mounted inside the excavating casing (4) for use in the excavation casing (4), which is detachably fixed to the inner side of the excavating casing (4). And a widening bucket (3) connected to the driving device (2) and enlarging the bottom of the vertical hole not surrounded by the excavating casing (4). 2) A drum-shaped casing main body (5), and a driving mechanism in which a bottom- up bucket (3) is connected to a lower end portion of the casing main body (5), which is arranged in a vertical position so as to be rotatable and movable up and down. Provided on shaft (6) and casing body (5) A rotational drive unit (7) for rotationally driving the drive shaft (6), a feeder device (8) provided on the casing body (5) for moving the drive shaft (6) up and down, and a casing body (5 ) And a chuck device (9) that presses the inner wall surface of the excavating casing (4) and fixes the intermediate excavator (1) itself to the inner wall surface of the excavating casing (4) , The widened bucket (3) includes a cylindrical main body (11) having a plurality of openings (11a) in the peripheral wall, an annular stabilizer (12) provided at the upper end of the main body (11), and a main body (11). A bottom cover (13) provided at the lower end of the main body (11) and a transmission shaft (14) which is detachably connected to the drive shaft (6) of the drive device (2). And one side edge of the opening (11a) of the main body (11) A plurality of widening blades (15) that are pivotally connected to a side edge and provided with a plurality of excavation bits (15a) on the other side edge to open and close the opening (11a) of the main body (11); The widening wing spans between a closed position where the widening wing (15) closes to the opening (11a) of the main body (11) and an open position where each widening wing (15) opens the opening (11a) of the main body (11). A plurality of open / close hydraulic cylinders (16) swingably swingable in the radial direction of the main body (11), and pull up the bottom expansion bucket (3) on the outer surface of each of the widening blades (15). A Nakabori excavator provided with guide rods (20) for slidingly guiding the inside of the excavation casing (4) .   The rotation drive unit (7) is configured to link a plurality of hydraulic motors (7 '), the output shafts of the respective hydraulic motors (7') and the drive shafts (6) to rotate the output shafts. The intermediate excavator according to claim 1, characterized in that it comprises a gear reducer (7 ") that transmits to 6).   The feeder device (8) includes a plurality of lifting hydraulic cylinders (8a) disposed at equal angles around the driving shaft (6) and fixed in a vertical posture to the casing body (5), and a driving shaft. It is arranged at a position below (6), and comprises a lift plate (8b) to which a drive shaft (6) is rotatably supported and to which a rod of a lift hydraulic cylinder (8a) is connected. 2. The Nakahori excavator according to claim 1, wherein the drive shaft (6) moves up and down via the lifting plate (8 b) as the hydraulic cylinder (8 a) expands and contracts.   The chuck device (9) is disposed on the casing body (5) so as to be reciprocally movable at equal angles and in the radial direction, and has an inner surface formed as an inclined surface and an outer surface within the excavating casing (4). A plurality of chuck members (9a) formed on a curved surface in close contact with the wall surface, a plurality of wedge bodies (9b) having inclined surfaces slidable on the inclined surfaces of the chuck members (9a), and a casing body (5) And a hydraulic chuck cylinder (9c) that moves up and down each wedge body (9b). Each chuck member (9a) is moved to each wedge as the chuck cylinder (9c) expands and contracts. The Nakabori excavator according to claim 1, wherein the excavator is configured to reciprocate in the radial direction of the casing body (5) via the body (9b).   The Nakabori excavator according to claim 4, wherein a liner (9e) is detachably provided on an outer surface of the chuck member (9a).

Images