JP2024089408A - Curved hole drilling method and flexible hole drilling device - Google Patents

Abstract

[Problem] To improve the efficiency of curved hole drilling. [Solution] In the curved hole drilling method, a hole (drilling hole H) is drilled in the ground G by a rotary head (drilling blade 16) attached to the tip of a rod 12, and the curved hole is drilled in the ground G while rotating the rotary head relative to the guide bit 34 with the guide bit 34 protruding forward from the rotary head facing the drilling direction. [Selected Figure] Figure 3

Description

The present invention relates to a curved hole drilling method and a flexible hole drilling device.

For example, drilling machines such as earth augers are known that drill holes in the ground when constructing retaining walls or piles (see, for example, Patent Documents 1 to 3).

In addition, a free-drilling machine is known that can drill straight and curved holes in the ground. In a free-drilling machine, a tapered surface (pressure-receiving surface) is formed on the tip bit used to drill a hole in the ground. When drilling a straight hole in the ground, the tip bit is rotated as it advances.

On the other hand, when drilling a curved hole, the tip bit is fixed with the tapered surface facing a specific direction, and the tip bit is pushed into the ground without rotating. This causes the attitude of the tip bit to change due to the earth pressure acting on the tapered surface from the ground, and the excavation direction (advancement direction) of the tip bit is changed. In this state, the tip bit is rotated while advancing, and the ground is drilled in a curved shape.
JP 2021-063396 A JP 2000-073396 A JP 2012-107444 A

As mentioned above, although curved hole drilling is possible with free boring, there is room for further improvement in order to increase the efficiency of curved hole drilling.

Taking the above facts into consideration, the present invention aims to improve the drilling efficiency of curved holes.

The curved hole drilling method of claim 1 is a drilling method for drilling a hole in the ground using a rotating head attached to the tip of a rod, in which a guide bit protruding forward from the rotating head is oriented in the excavation direction, and the curved hole is drilled in the ground while rotating the rotating head relative to the guide bit.

According to the curved hole drilling method of claim 1, a curved hole is drilled in the ground while rotating the rotary head relative to the guide bit, with the guide bit protruding forward from the rotary head facing the excavation direction.

By orienting the guide bit protruding from the rotating head in the drilling direction in this way, the rotating head is guided in the drilling direction. Therefore, the rotating head can be used to drill curved holes.

In addition, in the present invention, curved holes are drilled into the ground by rotating the rotary head rather than by rotating the guide bit, which can increase the efficiency of curved hole drilling.

The flexible drilling device of claim 2 comprises a rod, a rotating head attached to the tip of the rod and drilling holes in the ground while rotating, a guide bit protruding forward from the rotating head and guiding the rotating head in a direction of travel according to the direction of the tip, and a direction changing mechanism that changes the direction of the tip of the guide bit, and the rotating head drills holes in the ground while rotating relative to the guide bit.

According to the flexible drilling device of claim 2, a rotating head is provided at the tip of the rod. The rotating head drills holes in the ground while rotating. The guide bit protrudes forward from the rotating head and guides the rotating head in a direction of travel that corresponds to the orientation of the tip. The orientation of the tip of this guide bit is changed by a direction change mechanism.

Here, by changing the direction of the tip of the guide bit using the direction change mechanism, the rotating head is guided in a direction that corresponds to the direction of the tip of the guide bit. Therefore, the rotating head can be used to drill a curved hole.

The rotary head also rotates relative to the guide bit while drilling the ground. In other words, in this invention, curved holes are drilled in the ground by rotating the rotary head, not the guide bit, which increases the efficiency of curved hole drilling.

The flexible drilling device of claim 3 is the flexible drilling device of claim 2, in which the orientation change mechanism has at least three jacks that each extend and retract in the axial direction of the rod and support the outer periphery of the guide bit against the rod.

According to the flexible drilling device of claim 3, the orientation change mechanism has at least three jacks. The at least three jacks each extend and retract in the axial direction of the rod and support the outer periphery of the guide bit relative to the rod. By adjusting the length of these jacks, the orientation of the tip of the guide bit can be easily changed.

The present invention can improve the efficiency of curved hole drilling.

1 is an elevational view showing an overview of a flexible drilling device for implementing a curved hole drilling method according to an embodiment of the present invention. FIG. 2 is an elevational view showing a state in which the direction of the tip of the guide bit coincides with the axial direction of the rod. FIG. 11 is an elevational view showing a state in which the tip of the guide bit is tilted with respect to the axial direction of the rod. FIG. 13 is an elevation view showing the state in which the inclination of the borehole is being corrected.

The curved hole drilling method and the flexible hole drilling device according to the embodiment of the present invention will be described below with reference to the drawings. Components indicated with the same reference numerals in each drawing are the same components. However, unless otherwise specified in the specification, each component is not limited to one, and there may be multiple components.

In addition, explanations of configurations and symbols that are duplicated in each drawing may be omitted. Note that the present disclosure is not limited to the following embodiments, and may be implemented with appropriate modifications, such as omitting configurations, replacing them with different configurations, or combining one embodiment with various modified examples, within the scope of the purpose of the present disclosure.

<Free-drilling device>
1 shows a flexible drilling device 10 for carrying out a curved hole drilling method according to one embodiment of the present invention. The flexible drilling device 10 is formed with a rod 12, a screw 14 provided on the outer circumferential surface of the rod 12, and a drilling blade 16 provided at the tip of the rod 12.

The drilling blade 16 is an example of a rotating head in the present invention, and is also called an auger head. By rotating the drilling blade 16 relative to the rod 12, the bit 16A of the drilling blade 16 scrapes away the ground G, forming a drilling hole H in the ground G. The bit 16A has a downward-facing blade.

The screw 14 is a discharge mechanism that sends the discharged soil from the ground G excavated by the excavation blade 16 to the surface.

In Figure 1, the ground G is shown to be drilled in a straight line diagonally downward, but the ground G may also be drilled in a curved line. For example, the ground G may be excavated laterally to improve the ground below an existing building BL. In this case, a specified section is drilled in a curved line, as shown by area L, to change the drilling angle.

To achieve this type of curved drilling, as shown in Figure 2, a tilt detection device 20 is attached to the rod 12. In addition, a guidance device 30 is provided on the drilling wing 16.

(Tilt detection device)
The inclination detection device 20 is fixed to the tip and outer peripheral surface of the rod 12, and detects the inclination angle of the rod 12 with respect to the vertical (or horizontal) direction. The worker operating the flexible drilling device 10 can grasp the inclination angle detected by the inclination detection device 20 on the ground via a monitor or the like.

The tilt sensor 20 is positioned at different positions around the circumference of the rod 12 depending on the rotation angle of the rod 12. Therefore, the tilt angle has a different value depending on the rotation angle of the rod 12, but the tilt sensor 20 can also detect the rotation angle. This allows the worker to grasp in three dimensions in which direction and how much the rod 12 is tilted.

The rotation angle of the rod 12 does not necessarily have to be detected by the tilt detection device 20. For example, a mark can be placed on the upper end of the rod 12. It is preferable to place the mark at the same position where the tilt detection device 20 is fixed (the position in the circumferential direction of the rod 12). By having an operator visually check the mark, the rotation angle of the rod 12 can be ascertained.

(Guidance device)
The guide device 30 is formed to include a main body portion 32 , a guide bit 34 and a direction changing mechanism 36 .

The main body 32 is a cylindrical member fixed to the rod 12 and fixed to the inside of the drilling wing 16 via a bearing J such as a ball bearing. The bearing J creates a swivel mechanism in which the guide device 30 does not rotate even when the drilling wing 16 rotates in the circumferential direction. In other words, the drilling wing 16 can drill a hole in the ground G while rotating around its axis relative to the guide device 30 and guide bit 34, which are not rotating.

The guide bit 34 is a cone-shaped positioning member that is positioned to protrude forward from the drilling wing 16. "Forward" means forward of the bit 16A of the drilling wing 16 and forward in the direction of travel of the drilling wing 16.

The direction change mechanism 36 is a mechanism that changes the direction of the tip of the guide bit 34. The "direction of the tip of the guide bit 34" is the direction along the height direction of the cone that forms the guide bit 34. The direction change mechanism 36 includes a hydraulic cable 36A, a hydraulic jack 36B, and a covering material 36C.

The hydraulic cable 36A is a transport pipe that is connected from the ground to the hydraulic jack 36B via the inner tube 12A of the rod 12. A worker can inject oil into the hydraulic jack 36B or drain oil from the hydraulic jack 36B by operating it from the ground.

The hydraulic jack 36B is a support member that supports the outer periphery of the guide bit 34 relative to the rod 12. In other words, one end of the hydraulic jack 36B is fixed to the main body 32 of the guide device 30, and the other end is fixed to the outer periphery of the guide bit 34, thereby fixing the guide bit 34 to the tip of the rod 12.

Multiple hydraulic jacks 36B are provided around the circumferential direction of the guide bit 34. In this embodiment, three hydraulic jacks 36B are provided around the circumferential direction of the guide bit 34.

The hydraulic jack 36B expands and contracts along the material axis direction C1 of the rod 12 according to the amount of oil supplied from the hydraulic cable 36A. A different hydraulic cable 36A is connected to each hydraulic jack 36B. Therefore, the amount of expansion and contraction of each of the multiple hydraulic jacks 36B can be controlled individually. This allows the orientation of the tip of the guide bit 34 to be adjusted.

The covering material 36C is a partition material that prevents the hydraulic jack 36B from being exposed to sludge or cement milk, and displaces or deforms in response to the expansion and contraction of the hydraulic jack 36B. In addition, a cable gland CG is arranged above the main body 32 of the guide device 30, which prevents the cement milk flowing through the inner tube 12A of the rod 12 from flowing into the inside of the covering material 36C where the hydraulic jack 36B is arranged.

<Curved hole drilling method>
As shown by the arrow N1 in FIG. 2, by pressing the tip of the guide bit 34 against the bottom of the drilling hole H, the drilling wing 16 is guided in a direction according to the direction of the tip of the guide bit 34.

For example, when one or two of the three hydraulic jacks 36B are extended, the orientation of the tip of the guide bit 34 changes as shown in FIG. 3. More specifically, the orientation C2 of the tip of the guide bit 34 is inclined with respect to the material axis direction C1 of the rod 12.

In this state, by pressing the tip of the guide bit 34 against the bottom of the borehole H, the drilling blade 16 is guided in the direction of travel that corresponds to the direction of the tip of the guide bit 34, as shown by arrow N2. This allows the borehole H to bend.

When the drilling blade 16 is rotated to drill a borehole H while maintaining the direction C2 of the tip of the guide bit 34 inclined relative to the material axis direction C1 of the rod 12, the borehole H can be drilled in a curved line as shown by the dashed line H1. The curvature of the drilled hole is determined according to the direction C2 of the tip of the guide bit 34.

On the other hand, after bending the drilling hole H, the hydraulic jack 36B can be operated to align the direction C2 of the tip of the guide bit 34 with the material axis direction C1 of the rod 12. In this case, as shown by the dashed line H2, the drilling hole H can be drilled in a straight line in a direction inclined relative to the original drilling direction.

<Action and Effects>
According to the curved hole drilling method of the embodiment of the present invention, as shown in Figure 3, with the guide bit 34 protruding forward from the drilling wing 16 as a rotating head facing the drilling direction, the drilling wing 16 is rotated relative to the guide bit 34 to drill a curved hole H in the ground G.

In this way, the drilling wing 16 is guided in the drilling direction by orienting the guide bit 34 protruding from the drilling wing 16 in the drilling direction. Therefore, the drilling wing 16 can drill a curved drill hole H as shown by the dashed line H2.

In addition, according to the flexible drilling device 10 of the embodiment of the present invention, a drilling wing 16 is provided at the tip of the rod 12. The drilling wing 16 drills a hole in the ground G while rotating. The guide bit 34 protrudes forward from the drilling wing 16 and guides the drilling wing 16 in a direction of travel that corresponds to the direction of the tip. The direction of the tip of this drilling wing 16 is changed by a direction changing mechanism 36.

Here, by changing the direction of the tip of the guide bit 34 using the direction change mechanism 36, the drilling blade 16 is guided in a direction of travel that corresponds to the direction of the tip of the guide bit 34. Therefore, the drilling blade 16 can excavate a curved borehole H as shown by the dashed line H2.

The drilling blade 16 also drills the ground G while rotating relative to the guide bit 34. In other words, in the present invention, curved drilling is performed in the ground G by rotating the drilling blade 16, not by rotating the guide bit 34, and therefore the drilling efficiency of the curved drilling can be improved.

In addition, according to the flexible drilling device 10 according to an embodiment of the present invention, the direction changing mechanism 36 has three hydraulic jacks 36B. The three hydraulic jacks 36B each extend and retract in the axial direction of the rod 12 and support the outer periphery of the guide bit 34 relative to the rod 12. By adjusting the length of these hydraulic jacks 36B, the direction of the tip of the guide bit 34 can be easily changed.

Four or more hydraulic jacks 36B may be provided depending on the precision with which the tip of the guide bit 34 needs to be adjusted.

<Other embodiments>
In the above embodiment, a method for curved drilling of the ground G using the flexible drilling device 10 has been described, but the flexible drilling device 10 can also correct the curvature of the borehole H.

For example, there are cases where it is desired to form the borehole H along the vertical direction. However, if the soil quality of the ground G is uneven and there are hard areas in the direction of excavation, the rod 12 may tilt relative to the vertical direction as the borehole H is drilled, as shown in Figure 4.

In such a case, the hydraulic jack 36B is operated to adjust the direction of the guide bit 34 to the opposite direction to the inclination direction of the rod 12. At this time, the direction C2 of the guide bit 34 is adjusted so that it is aligned with the vertical direction.

In this state, by pressing the tip of the guide bit 34 against the bottom of the drilling hole H, the drilling blade 16 is guided in the direction of travel that corresponds to the orientation of the tip of the guide bit 34, i.e., the vertical direction, as shown by the arrow N3. This makes it possible to correct the curvature of the drilling hole H, as shown by the dashed line H3.

10 Flexible drilling device 12 Rod 16 Drilling blade (rotating head)
34 Guide bit 36 Direction change mechanism H Drilling hole (hole)

Claims (3)

A drilling method for drilling a hole in the ground by using a rotary head provided at the tip of a rod,
With the guide bit protruding forward from the rotary head facing the excavation direction, the rotary head is rotated relative to the guide bit to drill the curved hole in the ground.
Curved drilling method. Rod and
A rotary head is provided at the tip of the rod and rotates to drill a hole in the ground;
A guide bit that protrudes forward from the rotary head and guides the rotary head in a direction of travel according to the direction of the tip of the guide bit;
A direction changing mechanism for changing the direction of the tip of the guide bit;
Equipped with
The rotary head drills the ground while rotating relative to the guide bit.
Flexible drilling device. The direction changing mechanism has at least three jacks that extend and retract in the material axis direction of the rod and support an outer periphery of the guide bit with respect to the rod.
3. The flexible drilling device according to claim 2.