JP3115700B2 - Perforator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piercing device in which a casing is fitted around a piercing member such as an earth auger.

[0002]

2. Description of the Related Art FIG.
The following are known. The drilling device 1 is used for press-fitting a sheet pile PB into the ground G. The drilling device 1 is guided by a leader 3 erected on a front surface of a working machine main body 2 and vertically moved up and down by driving means (not shown) such as a hydraulic motor. Drive unit 4, an auger screw 5 which is suspended from the drive unit 4 and driven to rotate around an axis by a drive means (not shown) such as a hydraulic motor, and coaxially fitted on the outer peripheral side of the auger screw 5. And a casing 6 mounted at the upper end and fixed to the drive unit 4. And the casing 6
As shown in FIG. 15, a sheet pile PB having a substantially U-shaped cross section is mounted along the outer circumference of the casing 6. In order to press-in the sheet pile PB using the above-described drilling device 1, the drive unit 4 is lowered while rotating the auger screw 5, and as shown in FIG. At the same time, the casing 6 is pressed into the hole H formed by the auger screw 5 together with the sheet pile PB.
As a result, the sheet pile PB is guided by the casing 6 and pressed straight into the ground G without bending toward the center of the hole H. After the drilling to the desired depth is completed, the auger screw 5 and the casing 6 are pulled out leaving the sheet pile PB.
According to the above, after the ground G is drilled in advance, the casing 6
Since the sheet pile PB is press-fitted, the press-in resistance is smaller than when the sheet pile PB is driven alone, and the sheet pile PB can be press-fitted efficiently.

The auger screw 5 and the casing 6
The application of the punching device using the combination of the above is not limited to the press-fitting of the sheet pile PB. For example, in the construction of the foundation pile, as shown in FIG. 17, the casing 6 is press-fitted while the ground G is pierced with the auger screw 5 to protect the hole wall. In some cases, a foundation pile is formed by injecting a solidifying material such as cement into the hole while removing the casing 6 after the H steel 7 is erected.

[0004]

However, in the above-mentioned conventional drilling device 1, the cross-sectional shape of the hole H drilled by the auger screw 5 is limited to a circular shape, and thus has the following problems. When used for press-fitting of sheet pile PB, sheet pile P
Since the cross-sectional shape of B and the cross-sectional shape of the casing 6 do not match, even if the sheet pile PB is brought into close contact with the outer periphery of the casing 6 as shown in FIG. Occurs. The ground G located on the gap O is not excavated by the auger screw 5, but is crushed by the tip of the corner E of the sheet pile PB as shown in FIG. 16, so that the press-in resistance of the sheet pile PB is increased and the ground G is hard. In some cases, crushing can take a significant amount of time. In addition, sheet pile P
The earth and sand ES broken by B may enter the gap O, and the press-in resistance of the sheet pile PB may increase.

[0005] When used for the construction of a foundation pile, the diameter of the hole H needs to be larger than the diagonal dimension hmax of the H steel 7. Since the casing 6 must be prepared, the size of the apparatus is increased. In addition, if the diameter of the auger screw 5 is increased, the excavated volume is correspondingly increased and the amount of earth removed is increased. Furthermore, since a large gap remains between the H steel 7 and the hole wall, the amount of the solidified material necessary to solidify the periphery of the H steel 7 also increases. Incidentally, the minimum cross-sectional area A of the hole H with respect to the width h of the H steel 7 is A = (√2h) ² × π / 4 = 1.57h ² .

The above-described drilling device 1 may be used when a horizontally long hole _HL is formed in the ground G as shown in FIG. 18, but in such a case, a single hole drills a circular cross section. Since only the hole H can be formed, the previously formed hole H
_n-1 and allowed to partially overlap to form the following holes H _n, must still form a next hole H _{n + 1} with the hole H _n and is partially overlapped. For this reason, the number of perforations required until the hole _HL reaches the predetermined length is significantly increased, and the construction efficiency is reduced. Moreover, since the surplus soil G _R remains the border of the hole H between as shown in FIG hatched portion, it is necessary to work to remove it after the excavation.

[0007] It is an object of the present invention to provide a drilling device capable of forming a hole having a sectional shape according to the purpose of drilling.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1 showing an embodiment, the present invention is directed to a piercing member 5 for piercing the ground by rotating about an axis, and fitting around the outer periphery of the piercing member 5. The present invention is applied to a drilling device 10 including a hollow casing 20 that is mounted and pressed into the ground together with the drilling member 5.
The above-mentioned object is achieved by attaching the cutter 30 having the cutting edge 32a to the casing 20 such that the cutting edge 32a protrudes from the tip of the casing 20 in the axial direction and the radial direction.

In the punching device 10 according to the second aspect, the cutter 30
In order to improve the discharge performance of the soil ES that is disintegrated, the inner side surface 32 b of the side surface of the cutter 30 protruding from the tip of the casing 20 and facing the radial center side of the casing 20.
The closer to the center of the casing 20 in the radial direction, the farther it is retracted from the tip of the cutter 32 to the tip of the casing 20.
The punching device 10 according to claim 3 is suitable for press-fitting the sheet pile PB, and the cutter 30 closes a gap O generated between the sheet pile PB mounted on the outer periphery of the casing 20 and the casing 20, and the cutting edge thereof. The ridge 32a is provided so as to protrude from the gap O in the axial direction of the casing 20 beyond the tip of the sheet pile PB. The drilling device according to claim 4 is suitable for the construction of a foundation pile, and the cutter 60 is provided so as to draw a rectangular outer contour S around the casing 60 as shown in FIG. I do.

[0010]

In the punching device according to the first aspect, the casing 20 is provided.
At the time of press-fitting, the cutting edge 32a of the cutter 30 is cut into the hole wall of the hole H drilled by the drilling member 5, and a part of the hole wall is cut off. Spread according to. In the punching device 10 according to the second aspect, the cutter 30 is used.
The earth and sand collapsed by the above is guided into the inside of the casing 20 along the inner side surface 32b of the cutter 30. The drilling device 1 according to claim 3.
0, the cutter 30 provided to close the gap O between the sheet pile PB and the casing 20 causes the perforating member 5 to be closed.
The hole H having a circular cross section formed by is expanded along the cross-sectional shape of the sheet pile PB. In the piercing device 40 of the fourth aspect, the hole H having a circular cross section formed by the piercing member 5 is expanded in a rectangular cross section.

In the means and means for solving the above problems which explain the constitution of the present invention, the drawings of the embodiments are used to make the present invention easy to understand. However, the present invention is not limited to this.

[0012]

Embodiments of the present invention will be described below in detail with reference to the drawings. Components common to the above-described conventional example are denoted by the same reference numerals, and a description thereof will be partially omitted.

-First Embodiment- As shown in FIGS. 1 and 2, a punching device 10 of the present embodiment is provided.
Is used for press-fitting the sheet pile PB into the ground G. The auger screw 5 is rotated around an axis and pierces the ground G. The auger screw 5 is fitted coaxially around the outer periphery of the auger screw 5. And a hollow casing 20 that is pressed into the ground. As shown in FIG. 3, in the auger screw 5, a plurality of spiral guide plates 5b are arranged on the outer periphery of a core 5a extending along the axis, and a bit 5c for breaking the ground is provided at the tips of the core 5a and the guide plate 5b. It is attached and is hung down from a drive unit 4 that moves up and down along the reader 3 of the work machine, and is driven around an axis by a hydraulic motor in the drive unit 4 (FIG. 1).
4). As shown in FIG. 4, the casing 20 has a flange 21 at an upper end thereof, and the flange 21 is fixed to a lower end of the drive unit 4 so that the casing 20 can be moved up and down in synchronization with the auger screw 5.

As shown in FIGS.
A sheet pile engaging portion 22 is provided on the outer periphery of the tip of the sheet. The sheet pile engaging portion 22 includes a pair of push plates 22a protruding from the outer peripheral surface 20a of the casing 20, and a pair of insertion shafts 22b attached to the distal end of the push plate 22a and extending in the axial direction of the casing 20. Inserting the insertion shaft 22b into the gap between the beam B of the sheet pile PB and the corner E of the sheet pile arranged along the outer circumference of the sheet 20 and engaging the lower end of the push plate 22a with the beam B, The beam B of the sheet pile PB is pressed by the push plate 22a with the press-fitting operation to the ground, and the entire sheet pile PB can be drawn into the ground.

As shown in FIGS. 4, 5 and 7, a pair of cutters 30 are attached to the tip of the casing 20. These cutters 30 are provided on the outer peripheral surface 2 of the casing 20.
It has a mounting portion 31 to be welded to Oa and a digging portion 32 protruding from the tip of the casing 20. The mounting part 31
It has a substantially triangular pyramid shape in which the amount of protrusion from the casing outer peripheral surface 20a in the radial direction increases toward the tip of the casing 20. The excavated portion 32 has a substantially triangular pyramid shape that protrudes sharply in the axial direction of the casing 20, and the amount of protrusion in the radial direction from the casing outer peripheral surface 20a is constant. On both sides of the excavated portion 32, cutting edge ridges 32a extending from the distal end of the excavated portion 32 toward the base end are formed.

As shown in FIG. 1 and FIG.
The inner side surface 32b connected to a has a concave curved surface approaching the radial center side of the casing 20 from the tip of the cutter 30 toward the tip of the casing 20, and the radius of curvature R impairs the strength of the excavated portion 32. It is set large enough so that there is no. The inner surface 32b has a radius of curvature R of zero,
That is, it may be formed on a slope having a constant gradient.

Each of the cutters 30 is connected to the casing 20.
Sheet PB engaged with the sheet pile engaging portion 22 and the casing 20
And the mounting position, cross-sectional shape and dimensions thereof are determined such that the gap O generated between the excavation portion 32 and the tip of the excavated portion 32 projects from the gap O beyond the tip of the sheet pile PB to the tip of the casing 20 in the axial direction. Have been.

Using the drilling device 10 of this embodiment, the ground G
In order to press-fit the sheet pile PB into the casing 20, the sheet pile PB is arranged on the outer periphery of the casing 20 and the tip end thereof is engaged with the sheet pile engaging portion 22, and as shown in FIG.
Is pressed into the hole H formed by the auger screw 5. Thereby, the sheet pile PB is pressed by the push plate 22a of the sheet pile engaging portion 22 of the casing 20, and is pressed into the ground G together with the casing 20. After the drilling is completed to a desired depth, the auger screw 5 and the casing 20 are pulled out to release the engagement between the sheet pile PB and the sheet pile engaging portion 22 of the casing 20 to remove the sheet pile PB.
Only in hole H.

In the above procedure, the cutting edge 32a of the cutter 30 breaks down the ground G prior to the press-fitting of the casing 20, whereby the hole H having a circular cross section formed by the auger screw 5 is formed between the sheet pile PB and the casing 20. Are radially widened along the shape of the gap O between them. For this reason, the amount by which the ground G breaks down at the tip of the sheet pile PB is extremely small. In addition, the resistance when the cutter 30 cuts through the ground G is much smaller than the resistance when the sheet pile PB having no cutting edge crushes the ground G. Therefore, the press-in resistance of the sheet pile PB is remarkably reduced as compared with the related art, and the sheet pile P is easily formed even on the hard ground G.
The work can be completed in a short time by press-fitting B. In the present embodiment, since the gap O is closed by the cutter 30,
There is no possibility that the earth and sand ES broken down by the cutter 30 enters the gap O to increase the press-in resistance. The earth and sand ES is smoothly guided into the inside of the casing 20 along the inner side surface 32b of the cutter 30, and is quickly discharged to the ground by the auger screw 5, so that the earth and sand ES can be easily discharged.

-Second Embodiment-Next, an embodiment in which the present invention is applied to a drilling device for foundation pile construction will be described. Note that components common to the first embodiment are denoted by the same reference numerals, and description thereof will be omitted. As shown in FIGS. 8 and 9, the difference between the punching device 40 of the present embodiment and the first embodiment is that the sheet pile engaging portion is removed from the outer periphery of the casing 50 fitted on the outer peripheral side of the auger screw 5. In addition, at the point where a total of four cutters 60 each having a substantially triangular pyramid shape having a pair of cutting edge ridges 60a are attached to the front end of the casing 50, one at a time dividing the casing 50 into four equal parts in the circumferential direction. is there. The cross-sectional shape and dimensions of these cutters 60 are determined so as to draw a square outer peripheral contour S around the casing 50 in a plan view (FIG. 9) from the axial direction of the casing 50. The inner surface 60b of the cutter 60 facing the center of the casing is closer to the radial center of the casing 50 as it retracts from the tip of the cutter 60 to the tip of the casing 50 as in the first embodiment. .

In this embodiment, the casing 50 is pressed into the ground following the perforation by the auger screw 5, so that a hole H _O having a circular cross section formed by the auger screw 5 is formed as shown in FIG. is enlarged in accordance with the outer peripheral profile S of the cutter 60, the sectional shape of the finally obtained hole H _S is a square. Therefore, the H steel 7 built in the hole H _S
The auger screw 5 and the casing 50 having a smaller diameter than the diagonal dimension hmax can be used, and the size of the apparatus can be reduced. In addition, since the cross-sectional area of the hole H _S becomes smaller than before, the amount of earth removed is reduced, and the amount of the solidified material injected into the hole H _S is also small. Incidentally, the minimum sectional area of the hole H _S is h ^2, which is 36% as compared with the conventional minimum sectional area.
To a degree.

In this embodiment, since a hole H _S having a square cross section can be formed, a plurality of holes H _S can be formed such that their boundaries are in contact with each other even when forming a horizontally long hole _HL as shown in FIG. It is only necessary to repeat the formation, the number of drilling times is remarkably reduced, and it is not necessary to remove the residual soil at the boundary between the holes H _S after drilling, so that the construction efficiency is greatly improved. further,
Since the hole wall of each pore H _S is planar, the finish of the hole wall may be compared when the cut through the plane subsequently to form a circular cross section bore. In the case where the horizontally long hole _HL is formed as described above, as shown in FIGS.
By piercing at the same time by connecting two or more 0
Construction efficiency can be further improved.

The cutters 30, 60 described in the above embodiments
The arrangement and shape of the cutter are merely examples, and the shape and arrangement of the cutter in the present invention are variously changed according to the purpose of drilling. For example, in the first embodiment, the cross-sectional shape and the arrangement of the cutter 30 are appropriately changed according to the change in the cross-sectional shape of the sheet pile PB. In the second embodiment, an arbitrary polygonal cross section can be obtained according to the arrangement and dimensions of the cutter 60, such as forming three or five or more cutters 60 and forming a hole having a triangular or pentagonal cross section.

[0024]

As described in detail above, according to the present invention, the hole wall of the hole drilled by the drilling member is widened according to the sectional shape of the cutter.
By appropriately selecting the dimensions, an excellent effect that a hole having a sectional shape suitable for the purpose of drilling can be easily formed can be obtained. According to the second aspect of the present invention, the earth and sand broken by the cutter is smoothly guided into the inside of the casing. In the punching device according to the third aspect, the hole wall formed by the punching member is widened by the cutter along the cross-sectional shape of the sheet pile, so that the press-in resistance of the sheet pile is reduced and the efficiency of the sheet pile press-in operation is improved. In the drilling device according to claim 4, since the hole wall formed by the drilling member is expanded in a rectangular cross section, the diameter of the drilling member and the casing can be reduced when the foundation pile is constructed, and the device can be downsized. And the amount of solidified material injected into the hole after drilling can be reduced.

[Brief description of the drawings]

FIG. 1 is a diagram showing a state in which a sheet pile is being press-fitted while piercing the ground with a drilling device according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II in FIG.

FIG. 3 is an enlarged view showing a tip portion of an auger screw of the drilling device of FIG. 1;

FIG. 4 is a side view of a casing of the punching device of FIG. 1;

FIG. 5 is a diagram showing a state in which a distal end portion of the casing of FIG. 4 is viewed from a direction V in FIG.

6 is a view showing a sheet pile engaging portion of the casing of FIG. 5,
FIG. 6A is a cross-sectional view taken along the line VI-VI of FIG.
Sectional view taken along VI _B -VI _B line (A)

FIG. 7 is a diagram showing a state in which the distal end portion of the casing in FIG. 5 is viewed from the VII direction in FIG. 5;

FIG. 8 is a perspective view showing a distal end portion of a casing of a punching device according to a second embodiment of the present invention.

FIG. 9 is a diagram showing a state in which the casing of FIG. 8 is viewed from a direction IX in FIG. 8;

FIG. 10 is a view showing a state in which H steel is installed in a hole formed by the drilling device of FIG. 8;

FIG. 11 is a view showing a state in which a horizontally long hole is formed by the punching device of FIG. 8;

FIG. 12 is a view showing a modification of the punching device of FIG. 8;

FIG. 13 is a view showing a state in which the punching device of FIG. 12 is viewed from the XIII direction in FIG.

FIG. 14 is a diagram showing a state in which a punching device is attached to a work machine to perform a punching operation.

FIG. 15 is a sectional view taken along line XVI-XVI in FIG. 14;

FIG. 16 is a diagram showing a state in which a sheet pile is being pressed in while piercing the ground using a conventional piercing device.

FIG. 17 is a view showing a state in which H steel is erected in a hole formed by a conventional drilling device.

FIG. 18 is a view showing a state in which a horizontally long hole is formed by a conventional punching device.

[Explanation of symbols]

 5 Auger screw 10, 40 Drilling device 20, 50 Casing 30, 60 Cutter 32a, 60a Cutting edge 32b, 60b Inner surface of cutter G Ground H Hole O Gap between sheet pile and auger screw PB Sheet pile S Outer contour of cutter

Claims (4)

(57) [Claims] 1. A piercing device comprising: a piercing member that rotates around an axis to pierce the ground; and a hollow casing that is fitted around the piercing member and pressed into the ground together with the piercing member. A perforation device, wherein a cutter having a cutting edge is attached to the casing such that the cutting edge protrudes from a tip end of the casing in an axial direction and a radial direction. 2. The side surface of the cutter, the inner surface of the casing projecting from the tip of the casing and facing the radial center of the casing retreats from the tip of the cutter to the tip of the casing in the radial direction of the casing. The perforation apparatus according to claim 1, wherein the perforation apparatus is close to a center side. 3. The casing according to claim 1, wherein the cutter closes a gap formed between the sheet pile mounted on the outer periphery of the casing and the casing, and a cutting edge of the cutter extends from a tip of the sheet pile through the gap. The drilling device according to claim 1, wherein the punching device is provided so as to protrude in an axial direction. 4. The perforating apparatus according to claim 1, wherein the cutter is provided so as to draw a rectangular outer contour around the casing.