JP2608022B2 - Earth auger - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a soil cement column in which excavated earth and sand and a hardening liquid such as cement milk are stirred and mixed in the ground, and in particular, one or a plurality of enlarged portions in the axial direction of the borehole. The present invention relates to an earth auger used for forming a soil cement column provided with a slab.

[0002]

2. Description of the Related Art In general,
When a cast-in-place pile or the like is formed on the ground, it is known to provide a plurality of enlarged portions in the pile axis direction, that is, in the depth direction, in order to increase the peripheral bearing capacity of the pile, but in the conventional construction method, It has the following disadvantages.

[0003] That is, a method of constructing a foundation pile by pouring ready-mixed concrete into the borehole after discharging the soil in the borehole.
Alternatively, after the cement milk is injected into the borehole, the existing pile is laid down to form the foundation pile. There is a possibility that the enlarged diameter portion in the borehole collapses before the concrete is poured or the cement milk is injected.

Further, an earth auger as a forming device used for this is a device in which a diameter expanding device is also used as a digging device provided at the tip of the auger, or provided on a part of a screw blade or the like. Therefore, even if it is suitable for an excavation hole, it is not suitable for excavation of an enlarged diameter portion, and it is not possible to form an enlarged diameter portion having a satisfactory shape.

[0005] In addition, even in a construction method in which excavated earth and sand and a hardening liquid such as cement milk are agitated in a borehole having an enlarged diameter portion to form a mixed soil cement column, the drilling hole and the construction work are not performed. When performed using the same device as described above, the stirring effect of the diameter expanding device is low,
It is not possible to sufficiently mix not only the main body portion of the soil cement column but also the enlarged diameter portion. If the mixing is not performed sufficiently, the enlarged diameter portion may collapse, and a sufficient supporting force cannot be obtained.

[0006] Also, in the case of forming a soil cement column having a plurality of enlarged diameter portions in the depth direction, the conventional device cannot simultaneously form the plurality of enlarged diameter portions.

[0007] Furthermore, there is no practice of changing the degree of diameter expansion of a plurality of diameter-expanded portions in various ways so as to obtain an optimum pile supporting force in accordance with the properties of the ground.

In order to solve the above problem, the present inventors use an earth auger provided with one or a plurality of enlarged blades which can protrude in a substantially radial direction by operating a cylinder mechanism on an auger shaft. That is, when digging a predetermined ground with this earth auger, the enlarging blade is projected substantially in the radial direction, and a hardening liquid such as cement milk is discharged from the auger tip to agitate the ground soil and the hardening liquid. By mixing, a soil cement pillar having a mixed enlarged diameter portion is formed and constructed.

In the earth auger used in the above-mentioned construction method, as a means for projecting (expanding the diameter) the radially expanding blade substantially in the radial direction, a conventional method of reversing the rotation direction of the auger shaft requires a digging operation. And the excavation and stirring of the expanded portion cannot be performed at the same time, and the degree of expansion cannot be changed or adjusted.

[0010] Therefore, it is preferable that the expanding blade is provided so as to protrude by using a cylinder mechanism that utilizes a liquid such as oil or the pressure of air.

In this case, apart from the feeding means for feeding a hardening liquid such as cement milk or water discharged from the tip of the auger, a liquid such as oil or air for operating the cylinder mechanism is supplied. It is necessary to provide a supply means on the auger shaft, and it is necessary to be able to supply a liquid such as a curing liquid, water or oil, or air to each of these supply means as required.

In particular, since the rotating operation of the earth auger and the excavation of the enlarged diameter portion and the stirring operation are simultaneously performed, a predetermined liquid is supplied to each of the two kinds of feeding means while the auger is rotating. Etc. must be able to be sent.

[0013]

SUMMARY OF THE INVENTION The present invention has been made in view of the above, and has been described as an earth auger used in the above-mentioned construction method, that is, an earth auger having a cylinder mechanism, and a hardening liquid discharged from an auger tip. It is intended to provide an auger capable of surely supplying water, liquid such as oil for operating a cylinder mechanism, and air even when the auger is rotating, and is further suitable for the above-described construction method. It is intended to provide an earth auger that can be used for.

[0014]

An earth auger according to the present invention for solving the above-mentioned problems is provided with means for feeding a hardening liquid such as cement milk or water discharged from an auger shaft to an auger shaft, and an auger shaft. And a means for supplying a liquid such as oil or air for operating a cylinder mechanism having
A double swivel device is provided above the auger shaft or on the rotation transmission shaft of the deceleration motor, and in a state where the auger shaft is rotating, each of the two kinds of feeding means is provided with a predetermined force via the double swivel device. It is characterized in that it is formed so as to be able to supply a liquid such as a curing liquid, water or oil, or air.

In the above, it is preferable that the auger shaft is provided with one or a plurality of diameter-enlarging blades that are operated by a cylinder mechanism to increase the diameter, and that the auger shaft is provided with an electromagnetic valve for adjusting and controlling the operation of the cylinder mechanism.

Further, it is preferable that the adjustment control of the electromagnetic valve provided on the auger shaft is made controllable via a slip ring provided on the upper portion of the auger shaft or on the rotation transmission shaft of the reduction motor.

Further, it is desirable that the cylinder mechanism is provided with a position sensor for measuring and controlling the extension of the rod of the cylinder mechanism.

[0018]

According to the above-mentioned earth auger, the soil cement column is formed by rotating the borehole in the predetermined ground, discharging a hardening liquid such as cement milk from the tip of the auger, mixing with the excavated earth and sand, and mixing. Can be created. In particular, when the earth auger is rotating, the curing liquid or the like can be supplied to the feeding means via a double swivel device provided above the auger shaft or on the rotation transmission shaft of the reduction motor. Also, liquid such as oil or air for operating the cylinder mechanism can be supplied, and the cylinder mechanism can be operated and operated while the auger is rotating.

For example, if one or more expanding blades are provided on the auger shaft for operating and expanding by the cylinder mechanism, the auger shaft can be used when the earth auger is used to construct a rotary excavation hole. By operating the cylinder mechanism as described above and projecting the enlarged diameter blade, the enlarged diameter portion can be excavated, and in this state, a hardening liquid such as cement milk is discharged from the auger tip to agitate and mix with the excavated earth and sand. As a result, even in the case of one or a plurality of enlarged diameter portions, the outer peripheral portion can be sufficiently and reliably stirred and mixed by the enlarged diameter blade, thereby forming a soil cement column having an enlarged enlarged diameter portion in a good mixing state. it can.

If an electromagnetic valve for adjusting and controlling the operation of the cylinder mechanism is provided on the auger shaft, the enlarged blade can be appropriately protruded or retracted from the ground by an electric signal to the electromagnetic valve. Also, it is possible to easily adjust the degree of expansion of the expanded portion.

In this case, if the electromagnetic valve is formed so as to be capable of transmission control via a slip ring, the above-mentioned adjustment control can be performed without any problem even during rotation of the auger.

Further, if the cylinder mechanism is provided with a position sensor for measuring and controlling the amount of extension of the rod of the cylinder mechanism, the diameter of the cylinder is increased by adjusting the amount of extension of the rod. Easy adjustment of blade expansion
It can be changed, a soil cement column having enlarged portions having different diameters in the pile axis direction can be formed, and a plurality of upper and lower enlarged portions can be simultaneously formed.

[0023]

Embodiments of the present invention will be described below with reference to the drawings.

The earth auger (A) of the embodiment is used for a method of forming a soil cement column. FIG. 1 shows the entire earth auger (A), and a well-known structure is provided at the tip of the auger shaft (1). A drilling head (H) is provided. In the axial direction of the auger shaft (1), a plurality of screw blades (7), a stirring blade (2) and a plurality of expanding stirrers (K) are provided at appropriate positions at appropriate intervals in the axial direction. I have.

The screw blade (7) is for excavation, and is provided with a part of the auger shaft (1) wound several turns. The stirring blade (2) comprises a rod-shaped projection protruding in the radial direction, and is provided with a drill bit (8) and the like.

In the above-described diameter-enlargement stirring device (K), the diameter-enlargement blade (3) is advanced and retracted into a cylindrical stirring blade (2a) projecting substantially radially from the auger shaft (1). It has a structure inserted as possible. Inside the agitating blade (2a), a cylinder mechanism (6) such as hydraulic pressure or hydraulic pressure or air pressure penetrates the auger shaft (1) in the diametric direction as a means for operating the expanding blade (3). Rod (6a) in this cylinder
The expanding blade (3) is connected to the shaft, and the expanding and contracting action of the rod (6a) causes the expanding blade (3) to slide in the stirring blade (2a) and protrude and retreat in the radial direction. Then, the diameter is appropriately increased and decreased.

The cross-sectional shape of the stirring blade (2a) is a round or square pipe, and a diameter-enlarging blade (3) inserted into the pipe.
Is also formed in a corresponding round or square shape.

The number of the expanding blades (3) inserted into one expanding agitating device (K) is usually one or two, and the length of the expanding blade (3) depends on the diameter of the drilling hole and the degree of expansion. The stroke of the cylinder mechanism (6) is appropriately selected and used.

In the case where the number of the diameter-enlarging blades (3) is one, as shown in FIG. 4, it is provided so as to protrude only in one direction by a single rod type cylinder mechanism (6). In this case, it is desirable that the upper and lower diameter agitating devices (K) are provided with their protruding directions displaced sequentially, for example, at right angles to each other.

When the number of the expanding blades (3) is two, as shown in FIG. 5, the two expanding blades (3) and (3) are projected by the cylinder mechanism (6) in two opposite directions. A double rod type cylinder or two cylinders are used.

(4) is a feed pipe as a means for feeding a liquid such as oil or air to the cylinder mechanism (6), and is composed of a pair of feed and return pipes. The cylinder mechanism (6) is operated by hydraulic pressure or air pressure, such as hydraulic pressure, sent by the feed pipe (4), whereby the enlarged diameter blade (3) projects and retracts.

In the embodiment shown in FIG. 6 as means for supplying a liquid such as oil or air to the supply pipe (4), FIG.
As shown in, the auger shaft (1) is provided with a feed pipe (4) and the pump installed on the ground or on a construction machine
(Y) is connected to the rotation transmission shaft (1b) of the reduction motor (M) or the double swivel device (B) provided on the upper portion (1a) of the auger shaft (1). It is connected to the feeding pipe (4) and provided so as to be able to feed.

In the case of the figure, the above-mentioned double swivel device (B)
Is a column (13) suspended from the deceleration motor (M) and the column (1
3) It is provided on the upper part (1a) of the auger shaft (1) which is supported by the fixed arm (11) protruding from it and connected to the rotation transmitting shaft (1b). The structure is, for example, as shown in FIG.
An annular main part (B1) having a hollow inner peripheral side is provided on the outer periphery of the upper part (1a) formed of a double pipe through the sealing means (B2) such as an O-ring and the hollow part (B3). The main part (B1) is connected to the hose (10) while maintaining the sealed state and allowing rotation of the upper part (1a).
The outer pipe of (a) is provided with one or a plurality of flow holes (B4) at a portion corresponding to the hollow portion (B3), and is connected to the feed pipe (4) through this pipe.

In this case, a liquid such as oil or air can be fed from the hose (10) to the feed pipe (4) while the auger shaft (1) is kept rotating. The same applies when the double swivel device (B) is provided on the rotation transmission shaft (1b) from the speed reduction motor (M).

The upper part (1a) of the auger shaft (1) and the inner pipe of the rotation transmitting shaft (1b) are provided with a pressure feed hole (1c) serving as a means for feeding a hardening liquid such as cement milk and water at the time of digging. ) As part of the nozzle hole of the auger shaft (1) tip drilling head (H)
(1n). In particular, it is not always necessary to connect the pressure-feeding hole (1b) and the nozzle hole (1n) through the inner hole of the auger shaft (1) or the pipe disposed in the inner hole, as shown in FIGS. In the upper part (1a), once pulled out by the pressure pipe (5), attached to the auger shaft (1) near the tip, and pulled into the auger shaft (1) near the tip, and inserted into the shaft hole of the drilling head (H). It can be configured to guide and connect to the tip nozzle hole (1n).

As means for supplying a liquid such as oil or air to the supply pipe (4), a hose (10) connected to a pump device (Y) installed on the ground or on a construction machine is directly supplied. It can also be connected to the service pipe (4). In this case, after excavating the ground to a predetermined depth with the earth auger (A), the rotation of the auger (A) is stopped, a liquid such as oil or air is supplied, and the cylinder mechanism (6) is operated to expand the ground. It is necessary to make the diameter blade (3) protrude, and after expanding the diameter by this protrusion, disconnect the connection and perform the diameter excavation. To reduce the diameter of the expanding blade (3), the reverse operation is performed.

Also, as in the illustrated embodiment, a solenoid valve (9) is provided in a part of a pressure sending circuit for oil or the like from the feeding pipe (4) to the portion of the diameter expanding agitator (K). At the same time, if each solenoid valve (9) can be opened and closed by the control unit (L) installed on the ground, the diameter expansion, diameter reduction, and degree of diameter expansion for each diameter stirrer (K) can be adjusted. You will be able to control it.

In this case, in order to remotely control each solenoid valve (9) from the control device (L), the rotation transmission shaft (1) of the reduction motor (M) is used.
The control device (L) and the respective solenoid valves (9) may be electrically connected to each other via the slip ring (S) provided on the b) or on the upper part (1a) of the auger shaft (1).

As shown in FIGS. 6 and 9, for example, as shown in FIGS. 6 and 9, an outer ring (14) supported by a fixed arm (12) extending inward from the support (13) has an upper part (1a). ) Is loosely fitted at a predetermined position on the outer periphery of the outer ring (14), and the transmission ring (17) from the control unit (L) is connected to the inner periphery of the outer ring (14).
On the other hand, a plurality of contact brushes (15) connected to the respective solenoid valves (9) are provided on the outer periphery of the corresponding shaft (1a). (15) The ring (1
6) is externally connected, and is configured to always maintain the connected state even when the auger shaft (1) rotates. Ring contrary to the above
(16) may be provided on the shaft (1a), and the brush (15) may be provided on the outer ring (14).

In addition to the above, the solenoid valve (9) is arranged in a part of the circuit by the pipe (4) for supplying hydraulic pressure or the like, and is supplied to the expanding stirrer (K) at that position. , It may be provided to control whether to send it downward by an electric signal.

In order to measure and control the amount of extension of the rod of each cylinder mechanism (6), that is, the degree of diameter expansion, etc.
Cylinder mechanism equipped with a position sensor such as a differential transformer
(6) may be used, or the amount of oil sent to the cylinder mechanism (6) may be measured with a flow meter such as oil provided in the pump (Y), and the extension of the rod of the cylinder mechanism (6) may be measured. You may ask.

As described above, the extension of the rod of the cylinder mechanism (6) is adjusted, and the diameters of the expanding blades (3) in the plurality of expanding stirrers (K) are made different to increase the degree of expansion. It is possible to construct a soil cement column having enlarged portions with different degrees of enlargement in the pile axis direction, and it is also possible to simultaneously construct a plurality of upper and lower enlarged portions.

Using the earth auger of the present invention described above,
Next, a case where the soil cement column construction method is implemented will be described.

As shown in FIG.
The earth auger (A) provided with (K) is connected to the deceleration motor (M), and the predetermined ground is drilled.

In this case, a hardening liquid such as water or cement milk is supplied through a double swivel device (B) while rotating and excavating, and discharged from a drilling head (H) at the tip of the auger.
In some cases, drilling is performed while mixing and mixing the soil and hardening liquid.

When the predetermined depth is reached, FIG.
As described above, the expanding blade (3) of the expanding stirrer (K) is protruded by the operation of the cylinder mechanism (6) to expand the diameter, and the expanded portion is excavated, and the nozzle hole (1n) at the tip of the auger is formed. )
A hardening liquid such as cement milk is discharged, and the ground earth and sand and the hardening liquid are stirred and mixed. In particular, in the enlarged diameter portion, the above-described enlarged diameter blade (3) can sufficiently and reliably stir and mix the outer peripheral portion.

At this time, if the degree of expansion of the expanding blade (3) is adjusted by the length of the expanding blade (3), the stroke of the cylinder mechanism (6), and the amount of rod elongation, the degree of expansion differs. Expanded part (5
A soil cement column (50) having 1) can be formed. In particular, a double swivel device provided on the upper part (1a) of the auger shaft (1) or the rotation transmission shaft (1b) of the reduction motor (M)
According to (B), while rotating, the liquid such as oil or air for operating the cylinder mechanism (6) can be supplied, and the cylinder mechanism (6) can be operated while being rotated. .

After the injection and mixing of the predetermined curing liquid are completed, the auger (A) is retracted with the diameter-enlarging blade (3) retracted into the stirring blade (2a) of the diameter-expanding agitator (K). Is lifted to the ground [FIG. 10 (c)], and a soil cement column (50) having one or a plurality of enlarged diameter portions is formed. If the injection and mixing are carried out even during the above-mentioned auger augmentation, a more uniform and high-strength soil cement column (50) is formed.

By operating the solenoid valve (9), the diameter expanding blade (3) can appropriately adjust the diameter expansion, diameter reduction, and degree of diameter expansion for each diameter expansion stirring device (K). In this case, a plurality of upper and lower diameter expanding portions (51) can be simultaneously formed, and further, as shown in FIG. 11A, a soil cement column having expanded diameter portions (51) having different expansion degrees in the pile axis direction. (50) can be created.

Normally, a steel cage (F) is inserted into the soil cement column (50) while it is not yet cured, as shown in FIG. 11 (a), or a steel pipe as shown in FIG. 11 (b). By inserting a pile or concrete pile (P), or by inserting a concrete knotted pile (Pa) or the like in the column (50) as shown in FIG. Create

When a knotted concrete pile (Pa) is installed, if the knot portion of the pile and the expanded portion of the soil column coincide with each other in the depth direction, a solid foundation having a larger bearing capacity is provided. Piles are built.

[0052]

As described above, according to the earth auger of the present invention, in a state where the earth auger is rotating, via the double swivel device provided above the auger shaft or on the rotation transmission shaft of the reduction motor. In addition to supplying hardening liquid such as cement milk and water to the feeding means, it is also possible to feed liquid such as oil and air for operating the cylinder mechanism and air to the feeding means. The cylinder mechanism can be operated while being rotated.

Therefore, if one or a plurality of diameter-enlarging blades, which are operated by the cylinder mechanism to expand the diameter, are provided,
At the time of rotary drilling by this earth auger, the cylinder mechanism can be operated to protrude the diameter-enlarging blade to excavate the diameter-expanded portion, and in this state, a hardening liquid such as cement milk is discharged from the auger tip to excavate the excavated earth and sand. By stirring and mixing, it is possible to sufficiently and surely agitate and mix the outer peripheral portion with the expanding blade at the same time, particularly in the expanded portion, thereby having one or more expanded portions having sufficient strength. A safe and secure soil cement column can be created.

Further, by making the diameter expansion degrees of the plurality of diameter expansion blades different, it is possible to excavate a plurality of diameter expansion portions at the same time and to form the holes with different diameters. A ground improvement pile can be obtained. In particular, when an electromagnetic valve for adjusting and controlling the operation of the cylinder mechanism is provided, by adjusting the operation of the cylinder mechanism by transmission to the electromagnetic valve from the ground, the expanding blade is appropriately protruded and retracted. The diameter expansion and diameter reduction can be adjusted, and the degree of diameter expansion of the diameter expanding portion can be freely selected.

Further, it is easy to adjust the projecting speed of the enlarged diameter blade. For example, if the enlarged diameter blade is gradually projected, the rotational load of the earth auger due to the increased diameter can be reduced, and a good enlarged diameter portion can be obtained. Can be created.

If the cylinder mechanism can be operated even when the auger is rotating through the double swivel device, it is not necessary to stop the rotation at the time of expanding the diameter, so that the expanding excavation and mixing can be performed. It can be performed smoothly and efficiently.

[Brief description of the drawings]

FIG. 1 is a front view of an earth auger according to the present invention.

FIG. 2 is an enlarged front view of a portion of a large-diameter stirring device provided with a large-diameter blade protruded by operation of a cylinder mechanism.

FIG. 3 is an enlarged front view of a digging head portion.

FIG. 4 is a partial cross-sectional view illustrating an example of a diameter expanding stirring device.

FIG. 5 is a partial cross-sectional view illustrating another example of a large-diameter stirring device.

FIG. 6 is a front view of the upper part of the auger.

FIG. 7 is a sectional view showing the structure of the double swivel device.

FIG. 8 is a sectional view showing a partially modified example of the preceding figure.

FIG. 9 is a cross-sectional view illustrating the structure of a slip ring.

FIGS. 10 (a), (b) and (c) are explanatory views of a construction state by the earth auger of the present invention.

11 (a), (b) and (c) are cross-sectional views illustrating a foundation pile made of a soil cement column formed using the earth auger of the present invention.

[Explanation of symbols]

 (A) ... Earth auger (H) ... Drilling head (1) ... Auger shaft (K) ... Expansion stirrer (2a) ... Stirring blade (3) ... Expansion blade (6) ... Cylinder mechanism (M) ... Deceleration Motor (B) ... Double swivel device (1a) ... Connecting shaft (S) ... Slip ring (50) ... Soil cement column (51) ... Expanded part

Claims (4)

(57) [Claims] 1. Discharge from the auger tip to the auger shaft
Means for supplying a hardening liquid such as cement milk or water, etc.
Oil and other liquids that operate the cylinder mechanism of the logger shaft
And air supply means, and auger shaft
Double swivel device on top or rotation transmission shaft of deceleration motor
In the state where the auger shaft is rotating,
The double swivel device is provided for each of the two types of feeding means.
It is formed so that a predetermined liquid etc. can be fed through
Earth Auger 2. The auger shaft is operated by a cylinder mechanism.
Provide one or more blades for expanding the diameter, and
Solenoid valve for adjusting and controlling the operation of the
An earth auger characterized by being provided . 3. An adjustment control of a solenoid valve provided on an auger shaft,
Provided above the auger shaft or on the rotation transmission shaft of the reduction motor
That transmission control is possible via the slip ring
The earth auger according to claim 2, characterized in that: 4. The cylinder mechanism lock is attached to the cylinder mechanism.
A position sensor to measure and control the elongation of the
The earth auger according to claim 1 or 2, wherein
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