JPH1122358A - Diameter enlarging excavator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a locking means in place of a conventional guide cutter to prevent an enlarging cutter from spreading radially. SOLUTION: The enlarging excavator is structured so as to make an excavation head 3 connected to the lower end of an excavation rod 2 and inserted into a pipe casing 1 that is forced out from the pipe casing by normal rotation and axial force fitting and the enlarging cutter 11 of the excavation head 3 spreads radially in the enlargement direction. In such case, it is structured by providing locking hardware 15 to prevent the enlarging cutter 11 from spreading in the excavation head 3 when the excavation head 3 is in the pipe casing 1, and by fixing a shear ring 16 to take out the locking hardware 15 from the excavation head 3 to the inside perimeter of the lower end of the pipe casing 1 when the excavation head 3 is pushed out from the lower end portion of the pipe casing 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drilling device for drilling a hole, and more particularly to a drilling device for drilling an underground hole having a bottom hole for constructing a foundation steel pipe pile or a concrete pile having a bulb portion in civil engineering work. It relates to a hole drilling device.

[0002]

2. Description of the Related Art Generally, in order to construct a foundation steel pipe pile or a concrete pile, an underground hole is drilled with an earth drill or the like. Then, in order to increase the bearing capacity of the foundation pile, the lower end of the foundation pile is widened in a bulb shape. For this purpose, the bottom of the underground hole is excavated at a required depth.

An apparatus for excavating the bottom of a hole with a diameter is disclosed, for example, in Japanese Unexamined Utility Model Publication No. 1-75194, entitled "Enlarged Hole Drilling Apparatus". In this enlarged hole drilling device, a bit body having drilling blades mounted on the outer periphery is rotatably mounted on a lower end of a joint rod by a predetermined angle, and an intermediate portion is rotated by a predetermined angle on a pivot supported on upper and lower brackets on the outer circumference of the bit body. An expanding blade freely attached is provided, and a pressing knock is provided in which a distal end portion protrudes toward a rear end portion of the expanding blade and a base end portion is fixed to an outer periphery of the joint rod. After restricting the rotation, the excavating rod is reversed, the tip of the pressing knock is protruded toward the rear end of the magnifying blade and pressed, thereby forcibly rotating the magnifying blade outward, The excavation is expanded by the enlarged blade.

However, according to the above-mentioned conventional enlarged hole drilling apparatus, the drilling rod must be reversely rotated in order to forcibly rotate the enlarged blade outward. Therefore,
An operation procedure of temporarily rotating the excavating blade with the excavating rod to excavate and temporarily excavating, excavating the excavating blade into the ground, and rotating the excavating rod in the reverse direction is required. Operation procedure is complicated, and there is an inconvenience of lowering work efficiency.

Therefore, the applicant has proposed that the excavating head connected to the lower end of the excavating rod and inserted into the pipe casing is extruded from the pipe casing by forward rotation and axial press-fitting during excavation. A large-diameter hole excavation device in which the enlarged blade of the head for use expands in the radial direction is provided (Japanese Patent Application No. 7-10240). In this device, when the enlarged blade is in the pipe casing, a guide blade to be locked so as not to open in the radially expanding direction is disposed so as to be able to slide on the inner peripheral surface of the pipe casing. The guide blade and the magnifying blade are operatively connected by a connecting member.

[0006]

However, a large-diameter hole excavator (Japanese Patent Application No. 7-10240) in which the enlarged blade of the excavating head extruded from the pipe casing expands in the radial direction is disclosed. When drilling while the guide blade is in the pipe casing and the drilling head is driven forward, the guide blade slides against the inner peripheral surface of the pipe casing to prevent the expansion blade from expanding. The guide blade is pressed against the inner peripheral surface of the pipe casing to increase the sliding resistance, causing a torque loss in the forward rotation of the excavating rod and damaging the pipe casing itself.

Accordingly, the present invention provides an enlarged-diameter hole excavator provided with a lock means in place of the guide blade for preventing the enlarged blade from opening in the diameter-enlarging direction.

[0008]

According to a first aspect of the present invention, there is provided an enlarged-diameter hole drilling apparatus in which a drilling head connected to a lower end portion of a drilling rod and inserted into a pipe casing is driven in a forward rotation and a axial direction during drilling. In the diameter increasing hole excavator in which the enlarged blade of the excavating head extruded from the pipe casing expands in the diameter increasing direction by press-fitting, when the excavating head is inside the pipe casing, the enlarging is performed. A stopper for preventing the blade from expanding is provided on the excavating head, and when the excavating head is pushed out from the lower end of the pipe casing, the shearing for removing the stopper from the excavating head is provided on the pipe casing. Characterized by being fixed to the inner peripheral surface at the lower end.

Therefore, the drilling rod is driven forward in a state where the drilling head is housed in the pipe casing to such an extent that the bit is exposed from the pipe,
The pipe casing and the drilling rod are pierced to a predetermined depth while being pushed into the ground at the same time. In this state, the protruding portion of the subshaft abuts against the stopper, the stopper abuts the lock seat, and the lock seat is fixed to the excavating head, so that the subshaft itself can rotate. Since it cannot be performed, the diameter of the expanding blade does not increase.

When the pipe casing is stopped from being pushed into the ground at the stage where the drilling is performed at a predetermined depth, and is pushed into the ground while rotating the drill rod forward, the drilling head is completely exposed from the pipe casing, At this time, the stopper comes into contact with the shearing, falls off between the lock seat and the projection of the sub-shaft and is removed, and the sub-shaft is free to rotate, so that the enlarged blade can rotate in the radially expanding direction. Then, it expands due to the centrifugal force and the resistance of the excavated soil and excavates the enlarged diameter hole.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. As shown in FIGS. 1 and 2, a drilling head 3 is connected to a lower end of a drilling rod 2 inserted into a pipe casing 1. The excavating head 3 is configured to be able to be taken in and out of the pipe casing 1 by moving the excavating rod 2 in the vertical direction. Pipe casing 1
A friction pipe 20 is fitted to the outer periphery of the lower end portion by a usual method of the construction method.

The drilling head 3 has a drilling rod 2 at the upper end.
A lower support plate 7 having a center portion of upper support plates 6 and 6 fixed horizontally above a main shaft 5 formed with a head 4 having a polygonal cross section for fitting a plurality of bits 8 at a lower portion. The center is fixed. The upper support plate 6 is a non-circular, rectangular or oval plate. Between the upper support plate 6 and the lower support plate 7, a pair of spiral-shaped excavating blades 9,
Reference numeral 9 is attached to the main shaft 5 by being wound about the center of the axis thereof and divided into upper and lower parts. A pair of left and right sub-shafts 10 and 1 are arranged at equal distances in the radial direction about the main shaft 5 and are parallel to each other.
0 are rotatably supported by the upper support plate 6 and the lower support plate 7, respectively, and enlarged blades 11, 11 are detachably attached to the lower ends of the sub-shafts 10, 10 by brackets 12, respectively. It protrudes in the radial direction. The magnifying blade 11 can be detachably attached to a bracket 12 fixed perpendicular to the sub shaft 10 with a pin or the like.

In the vicinity of the upper support plate 6, a lock seat 13 having an angled cross section is provided on the lower surface of the excavating blade 9 corresponding to the sub shaft 10, and the enlarged blade 11 is turned in the opening direction. The sub shafts 10 are provided with projections 14 that abut against the lock seats 13. on the other hand,
One end of an L-shaped lock fitting 15 is provided so as to be insertable and removable as a stopper fitted between the projection 14 and the lock seat 13, and a shearing 16 with which the other end of the lock fitting 15 abuts is connected to a pipe casing. 1 is fixedly disposed on the inner peripheral surface at the lower end. The shearing 16 has a protruding height in the radial direction that can abut the horizontal end portion 17 (see FIG. 3) of the lock fitting 15 within a range that does not hinder the rotation of the excavating head 3.

The lock seat 13 is fixed to the lower surface of the excavating blade 7 by welding or the like by welding or the like, and hangs at a predetermined length in parallel with the main shaft 5 and the sub shaft 10. Although the lock seat 13 is fixed to the lower surface of the excavating blade 9, it may be fixed to the main shaft 5 or both of the main shaft 5 and the lower surface of the excavating blade 9. Lock fitting 15
Is an L-shaped plate as shown in FIG.
It has a vertically lower end portion 18 that can be inserted and removed in the vertical direction between the lock seat 13 and the sub shaft 10, and a horizontal end portion 17 that projects horizontally in the outer peripheral direction of the excavating head 3. Since this lock fitting 15 is a single unit independent of the excavating head 3,
It is preferable that the digging head 3 is always attached to the digging head 3 via a connecting tool such as a chain having an appropriate length so as not to be separated from the digging head 3. The lock fitting 15 may have a tapered portion 19 inclined at a slight angle (about 10 degrees) inside the hanging lower end portion 18.

As shown in FIG. 4, the lock brackets 13 and 13 and the lock brackets 14 and 14 have a lock bracket 15 in contact with the inside of the lock bracket 13 and the lock brackets 15 have projections 14 respectively. The rotation of the enlarged blades 11, 11 in the direction in which the diameter of the enlarged blades 11 is increased is prevented by the rotation of the sub shaft 10 being stopped by contact. Then, when the lock fittings 15, 15 are detached from the lock seats 13, 13, as shown in FIG. 5, the sub-shafts 10, 10 rotate, respectively, and the projections 14, 14 become the lock seats 13, 1, respectively.
The enlarged blades 11 and 11 expand in a state where the rotation is stopped by abutting the other inner side of the blade 3.

As shown in FIGS. 10 and 11, the structure of the drive unit for moving the excavating head 3 in and out of the pipe casing 1 and rotating the excavating rod 2 is provided at the upper end of the pipe casing 1 as shown in FIGS. And the outer tube 2
A drive 21 such as a hydraulic motor is mounted and fixed to the base 21 at the upper end of the shaft 0, and an output shaft 23 of the drive 22 is connected to the excavating rod 2. On the other hand, at least a pair of hydraulic cylinders 24 diametrically opposed to each other in the diametrical direction of the outer tube 20 are suspended from the base 21, and the lower end of the piston rod 25 engaging with the cylinder 24 is fixed to the outer peripheral portion of the pipe casing 1. To the pedestal 26 via a bracket 27. Therefore, when the drive unit 22 is rotated, the excavating rod 2 is rotated, and when the piston rod 25 is pushed out from the hydraulic cylinder 24, the pipe casing 1 is pushed into the ground. Therefore, when pushing out the excavating head 3 from the pipe casing 1, the piston rod 25 may be retracted into the hydraulic cylinder 24 as shown in FIG.

Next, the operation of the above embodiment will be described. As shown in FIG. 6, the excavating head 3 is housed in the pipe casing 1 and only a part of the bit 8 and the excavating blade 9 are exposed to excavate. While being driven to rotate by the rod 2, it is pushed into the ground together with the pipe casing 1 to drill an underground hole 21 having a predetermined depth. At this time, since the enlarged blade 11 is in the pipe casing 1 and the projection 14 of the sub-shaft 10 is in contact with the lock fitting 15, the sub-shaft 10 rotates even if it tries to rotate in the direction in which the enlarged blade 11 expands. It is not possible (see FIG. 4).

When the drilling reaches a predetermined depth, the pushing of the pipe casing 1 is stopped and the drilling rod 2 is rotated, while the piston rod is inserted into the hydraulic cylinder 24 attached to the drive unit 22 shown in FIGS. 25 can be pushed further deeply by pulling
As shown in (1), the entire excavating head 3 comes out of the pipe casing 1. At this time, the horizontal end 1 of the lock fitting 15
7 comes in contact with the shearing 16 and falls off between the lock seat 13 and the projection 14 of the sub-shaft 10 and is removed. The sub-shaft 10 is free to rotate. It can be moved.

Therefore, the continuous rotation of the excavating rod 2 causes the enlarged blade 11 to extend radially by centrifugal force, and
It expands due to the resistance of the inner wall of the underground hole 21 (see FIG. 5),
The rotation of the sub-shafts 10, 10 is restricted by the projections 14, 14 of the sub-shafts 10, 10 abutting against the other inner sides of the lock seats 13, 13, respectively. The enlarged bottom hole 22 is drilled. Note that the dropped lock fitting 15 is held by a chain or the like so as not to separate from the excavating head 3. However, if the lock fittings 15, 15 hung by the chain interfere with the rotation of the excavating head 3, there is no need to connect them with a chain or the like. The lock fitting 15 is the excavating head 3
, It can be discharged from the upper end of the pipe casing 1 by being carried to the excavated earth and sand rising by the excavating blades 7.

After drilling a widening hole with a predetermined depth, when the drilling rod 2 is lifted upward while rotating in the reverse direction, the expanding blades 11, 11 rotate around the sub shafts 10, 10 toward the main body. The protrusions 14, 14 are lock seats 13, 13.
Away from the other inner side, whereby the diameters of the enlarged blades 11 and 11 are reduced, and the excavating head 3 is housed in the pipe casing 1 as shown in FIG.

[0021]

According to the present invention described above, when the excavating head is in the pipe casing, the stopper (lock fitting) makes the rotation of the enlarged blade in the radially expanding direction independent of the inner peripheral surface of the pipe casing. On the other hand, when the excavating head is pushed out of the pipe casing, the shearing removes the stopper so that the expanding blade can rotate in the direction of expanding the diameter, so there is no need for the conventional guide blade. And the disadvantage that it damages the pipe casing does not occur.

The excavating head is inserted into and taken out of the pipe casing through a hydraulic cylinder, whereby the excavating head is housed in the pipe casing to regulate the enlarged blade, while being extruded from the pipe casing and radially excavated by centrifugal force or centrifugal force. The excavation is controlled by controlling the enlarging blade necessary for excavating the excavation hole, so that the excavation hole can be continuously excavated without interrupting the excavation work by the forward rotation of the excavation rod. It goes without saying that the work efficiency is improved.

[Brief description of the drawings]

FIG. 1 is a front view showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along line SA-SA of FIG.

FIGS. 3A and 3B are a front view (A) and an SB-SB sectional view (B) of the lock fitting.

FIG. 4 is an enlarged view of a main part of FIG. 2;

FIG. 5 is an operation explanatory view of FIG. 2;

6 (A) is a sectional view similar to FIG. 2 and FIG. 6 (B) is a front view similar to FIG. 1;

FIGS. 7A and 7B are explanatory views of the operation of the excavating head when excavating the enlarged diameter hole, in which FIG. 7A is a sectional view similar to FIG. 2 and FIG. 7B is a front view similar to FIG.

8 (A) is a sectional view similar to FIG. 2 and FIG. 8 (B) is a front view similar to FIG. 1;

9 (A) is a sectional view similar to FIG. 2 and FIG. 9 (B) is a front view similar to FIG. 1; FIG.

FIG. 10 is a front view of a driving unit according to the embodiment of the present invention.

FIG. 11 is a side view of FIG. 6;

[Description of Signs] 1 ... Pipe casing 2 ... Drilling rod 3 ... Drilling head 5 ... Main shaft 6 ... Upper support plate 7 ... Lower support plate 8 ... Bit 9 ... Drilling blade 10 ... Sub shaft 11 ... Enlarged blade 13 ... Receiver Seat 14 ... Protrusion 15 ... Lock fitting (stopper) 16 ... Shearing

Claims (4)

[Claims] 1. An enlargement of the excavating head, which is connected to the lower end of the excavating rod and inserted into the pipe casing, is extruded from the pipe casing by forward rotation and axial press-fitting during excavation. In the drilling apparatus in which the blade expands in the radially expanding direction, when the drilling head is in the pipe casing, a stopper for preventing the expansion blade from expanding is provided in the drilling head. And, when the excavating head is pushed out from the lower end of the pipe casing, a shearing for removing the stopper from the excavating head is provided fixedly on the inner peripheral surface of the lower end of the pipe casing. Hole drilling rig. 2. The excavating head horizontally fixes an upper support plate to an upper end of a main shaft of a predetermined length detachably connected to a lower end of the excavating rod, and a plurality of bits at a lower end. The fixed lower support plate is fixed horizontally, and spiral blades are provided between the upper support plate and the lower support plate by being wound around the main shaft, and at equal distances in the radial direction about the main shaft. A pair of left and right sub-shafts that are aligned and parallel are rotatably supported at the lower support plate and the upper support plate at both ends thereof so that the enlarged blades can rotate at the lower end of the sub-shaft, respectively. 2. The drilling device according to claim 1, wherein the drilling device is detachably protruded in a radial direction. 3. The stopper is provided with a projection on a shaft that rotatably supports the enlarged blade, and an angle-shaped lock seat against which the projection abuts is fixedly provided on the excavating head. An L-shaped lock fitting which stops rotation of the sub-shaft by contacting the lock seat and the protruding portion, one end of which can be inserted and removed between the lock seat and the protruding portion, and the other end thereof The large-diameter excavating device according to claim 1, wherein a portion is arranged so as to be able to abut on the shearing. 4. An upper support plate is horizontally fixed to an upper end portion of a main shaft of a predetermined length detachably connected to a lower end portion of a drilling rod, and a lower support plate having a plurality of bits fixed to a lower end portion is horizontally fixed. And a spiral blade is provided between the upper support plate and the lower support plate so as to be wound around the main shaft, and a pair of left and right parallel and aligned at equal distances in the radial direction about the main shaft. The lower shaft is rotatably supported on the lower support plate and the upper support plate at both ends thereof, and the enlarged blade is rotatably and detachably protruded radially at the lower end of the sub shaft. To form an excavating head, and, in the vicinity of the upper support plate, a lock seat having an angled cross section is provided to the excavating head in a manner corresponding to the sub shaft, and One end of an L-shaped lock fitting is provided between the projection and the lock receiving seat, while a projection is provided on the sub-shaft so that the enlarged blade rotates in the expanding direction and abuts on the lock receiving seat. And can be inserted and removed.
A large-diameter hole drilling apparatus, wherein a shearing ring with which the other end of the lock fitting abuts is disposed on an inner peripheral surface of a lower end portion of a pipe casing into which the drilling head is inserted.