JP2024089407A - Drilling Method - Google Patents

Abstract

[Problem] To efficiently correct the bending of a hole when drilling the hole in the ground. [Solution] In the drilling method, a hole (drilling hole H) is drilled in the ground G by a rotating head (drilling blade 16) attached to the tip of a rod 12, if the rod 12 tilts during drilling, the rotating head is raised with an expansion bit 30 protruding radially outward from the rotating head, and the expansion bit 30 excavates the hole wall on the opposite side to the tilt direction of the rod 12. [Selected Figure] Figure 4

Description

The present invention relates to a hole drilling method.

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).

The drilling machine disclosed in Patent Document 1 includes a rod and a drilling head (drilling machine) attached to the tip of the rod. The outer periphery of the drilling head is provided with a protrusion for correcting the bending of the hole. If the hole bends during drilling, the drilling head is first raised to the position where the hole starts to bend. Next, the drilling head is rotated forward and backward with the protrusion of the drilling head inserted into the hole wall on the opposite side to the bending direction of the hole, and the hole wall is drilled to correct the bending of the hole.
JP 2021-063396 A JP 2000-073396 A JP 2012-107444 A

As mentioned above, the technology disclosed in Patent Document 1 can correct the bend in the hole, but there is room for further improvement in order to efficiently correct the bend in the hole.

Taking the above facts into consideration, the present invention aims to efficiently correct the curvature of a hole when drilling a hole in the ground.

The drilling method of claim 1 is a drilling method for drilling a hole in the ground with a rotating head attached to the tip of a rod, in which if the rod tilts during drilling of the hole, the rotating head is raised with an expansion bit protruding radially outward from the rotating head, and the expansion bit is used to excavate the hole wall on the opposite side to the tilt direction of the rod.

According to the drilling method of claim 1, if the rod tilts during drilling of the hole, the rotating head is raised with the expansion bit protruding radially outward from the rotating head, and the expansion bit is used to excavate the hole wall on the opposite side to the tilt direction of the rod.

In this way, the hole wall on the opposite side to the inclination direction of the rod (hereinafter referred to as the "opposite hole wall") is drilled with the expansion bit, thereby correcting the curvature of the hole.

In addition, by protruding the expansion bit radially outward from the rotating head while the rod is tilted, when the expansion bit is used to drill the opposite hole wall, the axial rigidity of the rod presses the expansion bit against the opposite hole wall. This allows the expansion bit to efficiently drill the opposite hole wall. Therefore, the present invention allows the curvature of the hole to be efficiently corrected.

The hole drilling method of claim 2 is the hole drilling method of claim 1, in which the rotating head is rotated forward and backward while the expansion bit is used to drill the hole wall on the opposite side to the inclination direction of the rod.

According to the drilling method of claim 2, the opposite hole wall is drilled with the expansion bit while the rotary head is rotated forward and backward. This allows the opposite hole wall to be drilled efficiently with the expansion bit. Therefore, the present invention allows the hole curvature to be corrected more efficiently.

The hole drilling method of claim 3 is the hole drilling method of claim 1 or claim 2, in which, when the inclination of the rod with respect to the drilling trajectory of the rotary head is equal to or greater than a predetermined value, the hole wall of the hole on the opposite side to the inclination direction of the rod is excavated by the expansion bit until the inclination becomes less than the predetermined value.

According to the drilling method of claim 3, when the inclination of the rod relative to the drilling trajectory of the rotary head is equal to or greater than a predetermined value, the expansion bit is used to drill the opposite hole wall until the inclination of the rod becomes less than the predetermined value.

In this way, the accuracy of correcting hole curvature can be improved by drilling the opposite hole wall based on the inclination of the rod relative to the drilling trajectory of the rotary head.

According to the present invention, when drilling a hole in the ground, it is possible to efficiently correct the curvature of the hole.

1 is an elevation view showing an overview of a hole-drilling device for carrying out a hole-drilling method according to an embodiment of the present invention. (A) is an elevational view showing the rod in an inclined state, and (B) is a top view showing an outline of the drilling wing. 1A is an elevational view showing the drilling wing rotated in reverse to protrude the expansion bit, and FIG. 1B is a top view of the drilling wing with the expansion bit protruding. 1A is an elevational view showing the rod being pulled up with the expansion bit protruding, and FIG. 1A is an elevation view showing the state in which the hole wall of a borehole is being drilled with an expansion bit, and FIG. 1B is a top view. 1A is an elevation view showing another state in which the hole wall of the borehole is being drilled by the expansion bit, and FIG. 1B is a top view. 1A is an elevational view showing the state after the inclination of the rod and the bending of the hole have been corrected, and FIG.

The hole-drilling method 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.

<Drilling equipment>
1 shows a drilling device 10 for carrying out a drilling method according to an embodiment of the present invention. The drilling device 10 is formed with a rod 12, a screw 14 provided on the outer circumferential surface of the rod 12, a drilling wing 16 provided at the tip of the rod 12, and a drilling wing 18 provided above the drilling wing 16.

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, the bit 16A of the drilling blade 16 scrapes away the ground G, and a drilling hole H is formed in the ground G. The bit 16A has a downward-facing blade.

On the other hand, the drilling wing 18 is an auxiliary wing provided to complement the drilling performance of the drilling wing 16, and is equipped with a bit 18A with a downward blade, just like the drilling wing 16. Thus, in this embodiment, the drilling wings are arranged in multiple stages.

The screw 14 is a discharge mechanism that sends the soil discharged from the ground G excavated by the excavation wings 16 and 18 to the surface.

In FIG. 1, the borehole H is formed approximately vertically, but 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 as the borehole H is drilled.

If drilling is performed with the rod 12 tilted, a bend will occur in the borehole H. For example, in the example shown in FIG. 2(A), the center line CL of the rod 12 is tilted at an angle θ with respect to the designed drilling trajectory H1 (for example, the vertical direction) of the drilling wing 16 shown by the dashed line. Therefore, the borehole H drilled with the tilted rod 12 is also formed with a bend at the angle θ.

To correct such bending of the drilled hole H, a tilt detection device 20 is attached to the rod 12. In addition, the drilling blade 16 is formed with an expansion bit 30 as shown in Figure 2 (B).

The expansion bit 30 can have a blade facing downward like the bit 16A, but it is preferable for the blade to face upward. It may also have a double-edged configuration with blades on both the top and bottom.

The drilling wing 18 also has an expansion bit 30 formed thereon. The expansion bit 30 provided on the drilling wing 18 has a similar configuration to the expansion bit 30 provided on the drilling wing 16, and detailed description thereof will be omitted.

The tilt sensor 20 is fixed to the tip and outer circumferential surface of the rod 12 and detects the angle θ of the rod 12 relative to the vertical direction. The worker operating the drilling device 10 can grasp the angle θ detected by the tilt sensor 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 angle θ has a different value depending on the rotation angle of the rod 12, but the tilt sensor 20 can also detect this rotation angle. This allows the worker to grasp in three dimensions the 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.

The expansion bit 30 is an expansion wing that can rotate around a rotation hinge 32, and is housed in the drilling wing 16 while the drilling wing 16 rotates in the direction indicated by the arrow N1 in FIG. 2(B) (hereinafter referred to as forward rotation).

On the other hand, when the drilling blade 16 rotates in the direction indicated by the arrow N2 in FIG. 3(B) (hereinafter referred to as reverse rotation), the tip of the expansion bit 30 catches on the wall of the drilling hole H, and the expansion bit 30 rotates around the rotating hinge 32 and protrudes in the radial direction of the drilling blade 16.

<Drilling method>
When drilling the borehole H, the drilling wings 16 and 18 are rotated in the direction indicated by the arrow N1 in Figures 2(A) and 2(B). As described above, during the forward rotation of the drilling wings 16, the ground G is excavated with the expansion bit 30 housed in the drilling wings 16.

When the rod 12 tilts during drilling of the borehole H, the drilling wings 16 and 18 are rotated in the reverse direction, as shown by the arrows N2 in Figures 3(A) and (B), causing the expansion bit 30 to protrude radially outward from the drilling wings 16 and 18. The expansion bit 30 gets caught on the wall of the borehole H and bites into the wall.

Here, "when the rod 12 is tilted" refers to a case where the tilt detection device 20 detects that the tilt of the rod 12 relative to the drilling trajectory H1 is equal to or greater than a predetermined value. Alternatively, it refers to a case where an operator checks the tilt of the rod 12 detected by the tilt detection device 20 and determines that the tilt is equal to or greater than a predetermined value.

The hole wall into which the expansion bit 30 protrudes and bites is the hole wall (opposite hole wall) on the opposite side to the inclination direction of the rod 12 (i.e., the direction in which the inclination is equal to or greater than a predetermined value).

In FIG. 3(B), the direction indicated by the arrow M when viewed from the center O of the rod 12 (direction when viewed from a plan view) is the inclination direction of the rod 12. Also, the hole wall in the direction rotated 180° from the center O of the rod 12 in the direction indicated by the arrow M and the hole walls around it are the opposite hole walls.

In this figure, the expansion bit 30 is biting into the hole wall in the direction of the arrow M rotated 180° when viewed from the center O of the rod 12. The position on the plane where the expansion bit 30 is biting into is referred to as position K1 in the following explanation.

Next, as shown by arrow N4 in Figures 4(A) and (B), the drilling wings 16 and 18 are raised while the expansion bit 30 is biting into the wall of the borehole H. At this time, the drilling wings 16 and 18 are raised without rotating. As a result, the expansion bit 30 is also raised as shown by arrow N5, and the wall of the borehole H is drilled.

Although the tip of the rod 12 is inclined with respect to the drilling trajectory H1, the angle is adjusted so that the rod 12 is aligned vertically near the ground surface. As a result, a bending force acts on the rod 12, and at the tip, a bending back force P acts in the opposite direction to the inclination direction due to the axial rigidity of the rod 12.

This bending back force P causes the expansion bit 30 to drill the wall of the borehole H while being pressed against the wall of the borehole H. Position K1 is at an angle of 180° to the inclination direction of the rod 12, so the largest bending back force P acts on position K1.

Next, the drilling wings 16 and 18 are pushed down again as shown by the arrows N6 in Figures 5(A) and (B). Then, the drilling wings 16 and 18 are rotated in the reverse direction as shown by the arrows N7, and then the drilling wings 16 and 18 are raised with the expansion bit 30 biting into the wall of the drilled hole H, in the same manner as described in Figure 4(A).

In this way, by repeating the operations shown in Figures 3 to 5, the wall of the borehole H (the region from position K1 to K2) is drilled in the "reverse rotation" direction of the drilling wings 16 and 18 from position K1 where the expansion bit 30 was first inserted. The rod 12 moves toward the drilled region V1, and the inclination is corrected.

On the other hand, the wall of the borehole H can also be drilled in the "forward rotation" direction of the drilling wings 16 and 18 from the position K1 where the expansion bit 30 is first inserted.

In this case, as shown in Figures 6(A) and (B), the drilling wings 16 and 18 are "forward rotated" as indicated by the arrow N8, and then, similar to the procedure described in Figure 4(A), the drilling wings 16 and 18 are raised with the expansion bit 30 biting into the wall of the drilled hole H. This allows the formation of the excavated area V2 (the area from position K1 to K3). The rod 12 moves toward the excavated areas V1 and V2, correcting the inclination.

As described above, the forward and reverse rotation of the drilling wings 16 and 18, the penetration of the expansion bit 30 into the hole wall associated with the reverse rotation, the downward and upward movement of the drilling wings 16 and 18, and the drilling of the hole wall by the expansion bit 30 associated with the upward movement are carried out multiple times in an appropriate combination.

As a result, as shown in Figures 7(A) and (B), the hole wall on the opposite side to the inclination direction of the rod 12 is excavated in stages, and the rod 12 moves to the excavated area, correcting the inclination. As a result, the bending of the rod 12 is corrected.

<Action and Effects>
According to the drilling method according to the embodiment of the present invention, when the rod 12 tilts during drilling of the borehole H as shown in Fig. 2(A), the expansion bit 30 is protruded radially outward from the drilling wings 16 and 18 as rotary heads as shown in Fig. 3(A) and (B). Then, as shown in Fig. 4(A), the expansion bit 30 is used to drill the wall of the borehole H on the opposite side to the tilt direction of the rod 12 while the drilling wings 16 and 18 are being pulled up.

In this way, the expansion bit 30 is used to drill the hole wall on the opposite side to the inclination direction of the rod 12, thereby correcting the curvature of the drilled hole H.

In addition, by protruding the expansion bit 30 radially outward from the drilling wings 16 and 18 while the rod 12 is tilted, when the expansion bit 30 is used to drill the opposite hole wall, the axial rigidity of the rod 12 presses the expansion bit 30 against the opposite hole wall. This allows the expansion bit 30 to efficiently drill the opposite hole wall. Therefore, in the present invention, the curvature of the drilled hole H can be efficiently corrected.

In addition, according to the drilling method of the embodiment of the present invention, the drilling blades 16 and 18 are rotated forward and backward while drilling the opposite hole wall with the expansion bit 30. This allows the opposite hole wall to be drilled efficiently with the expansion bit 30.

Specifically, according to this drilling method, position K1, which is 180° from the inclination direction of the rod 12, is first drilled on the hole wall opposite the inclination direction of the rod 12. After drilling from position K1 to position K2, the drilling blade 16 is rotated forward and drilling from position K3 to position K2 is performed.

This allows the wall of the borehole H to be drilled from the position where the bending back force of the rod 12 is the greatest, resulting in high drilling efficiency. Therefore, in this embodiment, the bending of the borehole H can be corrected even more efficiently.

<Other embodiments>
In the above embodiment, as shown in Fig. 7A, the hole wall of the drilling hole H is drilled until the inclination of the rod 12 becomes 0° with respect to the drilling trajectory H1 of the drilling wing 16, that is, until the rod 12 is aligned vertically, but the embodiment of the present invention is not limited to this. For example, the hole wall of the drilling hole H may be drilled until the inclination of the rod 12 becomes an angle less than a predetermined value with respect to the drilling trajectory H1.

This "predetermined value" can be set appropriately depending on the use of the borehole H. For example, when a prefabricated pile (such as a PHC pile) is to be inserted into the borehole H, the borehole H may have an inclination that ensures the necessary vertical accuracy for the prefabricated pile to be inserted. Therefore, the rod 12 may also be inclined according to the allowable inclination of the borehole H.

In this way, the accuracy of correcting the curvature of the drilled hole H can be improved by drilling the opposite hole wall based on the inclination of the rod 12 relative to the drilling trajectory H1 of the drilling wing 16.

In addition, in the above embodiment, the drilling wing as the rotating head is a multi-stage drilling wing equipped with drilling wings 16 and 18, but the embodiment of the present invention is not limited to this. For example, the drilling wing 18 may be omitted. Or, even if the drilling wing 18 is present, the expansion bit 30 may be omitted from this drilling wing. Also, a spreading wing may be arranged in place of the drilling wing 18. The expansion bit 30 may or may not be provided for this spreading wing.

In other words, in the present invention, it is sufficient to form an expansion bit 30 on at least the drilling wing 16 located at the tip of the rod 12. By forming an expansion bit 30 on the drilling wing 16, the curvature of the drilled hole H can be efficiently corrected by the above-mentioned drilling method.

In the above embodiment, after drilling the opposite hole wall relative to the inclination direction of the rod 12 from position K1 to position K2, which is 180° relative to the inclination direction, the drilling blade 16 is rotated forward to drill from position K3 to position K2 (reverse rotation → forward rotation → reverse rotation). This procedure is then repeated to drill the opposite hole wall in stages, but the drilling order of the opposite hole wall is not particularly limited.

For example, after drilling from position K3 to position K2, the drilling blade 16 can be rotated forward and this procedure can be repeated to drill the opposite hole wall in stages. Even with this drilling sequence, the curvature of the drilled hole H can be efficiently corrected.

12 Rod 16 Drilling wing (rotating head)
18 Drilling wing (rotating head)
30: expansion bit 32: rotation hinge 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,
When the rod is tilted due to drilling of the hole, the rotary head is raised with an expansion bit protruding radially outward from the rotary head, and the hole wall of the hole on the opposite side to the inclination direction of the rod is excavated by the expansion bit.
Drilling method. While rotating the rotary head forward and backward, the hole wall of the hole on the opposite side to the inclination direction of the rod is drilled by the expansion bit.
The method of drilling a hole according to claim 1. When the inclination of the rod with respect to the drilling trajectory of the rotary head is equal to or greater than a predetermined value, the hole wall of the hole on the opposite side to the inclination direction of the rod is drilled by the expansion bit until the inclination becomes less than the predetermined value.
The hole drilling method according to claim 1 or 2.