JP2002021460A - Drilling method and drill for use therein - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a drilling method for drilling a hole which is resistant to cave-in of its internal wall even in an area of brittle ground, to thereby enhance cost efficiency, and to obtain a drill for use in the drilling method. SOLUTION: The drill 10 includes a cylindrical cutting bit 12, a guide portion 32, and a taper coupler 36, and a rod 26 is penetrated through these component parts. Drilling is carried out by rotating the drill 10 and pressing the cutting bit 12 onto the ground so as to apply strikes onto the same. A through hole 20 is formed in the tip portion of the cutting bit 12 at a location decentered from its center. By jetting compressed air from the through hole 20, slime is raised to a side face of the drill 10. Since the through hole 20 is decentered from the center, the drill 10 is eccentrically rotated, and the slime is pressed onto an internal wall of the hole by a side face of the guide portion 32.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drilling method and a drilling tool used therefor, and more particularly to, for example, a drilling hole for inserting a bolt for fixing a net stretched to reinforce a slope of a mountain. The present invention relates to a method and a drill used therefor.

[0002]

2. Description of the Related Art In order to prevent landslides in mountains, there is a method of reinforcing the slopes of the mountains with concrete, for example. However, such a method requires a large amount of construction work, and it is necessary to cut down trees at the reinforcement. Therefore, such a method is not appropriate from the viewpoint of environmental protection. Therefore, as shown in FIG. 7, a method is adopted in which the net 1 is stretched and reinforced on the slope of the mountain to prevent landslides. In such a method, a bolt 2 is inserted into the ground to support the net 1, and the net 1 is
Is fixed.

In order to insert such a bolt, for example, a drilling tool as shown in FIG. 8 is used. In the drilling tool 3, a cutting bit 4 is formed at the tip, and a rod 5 on which a male screw is formed extends from the cutting bit 4. Each of the cutting bit 4 and the rod 5 has a through hole formed at the center thereof. The rod 5 of the drilling tool 3 is attached to a rock drill, and is pressed against the ground while rotating to form a hole in the ground. At this time, compressed air is sent through the through holes formed in the drilling tool 3. When the compressed air blows out from the tip of the cutting bit 4, slime, which is shavings, is discharged from the periphery of the rod 5 to the outside.

When a hole is drilled to a predetermined depth, the rod 5
Is used as a bolt for fixing the net as it is. At this time, mortar is injected from the through hole to fix the rod 5. The poured mortar is filled between the rod 5 and the inner wall of the hole from the tip of the cutting bit 4 and the rod 5 is fixed by solidifying the mortar.

[0005]

However, when the soil at the portion to be drilled is brittle, the inner wall of the formed hole collapses,
The injected mortar may not be sufficiently filled between the rod and the inner wall of the hole. In such a case, the rod is not sufficiently fixed, the support of the net becomes insufficient, and the effect of protecting the slope cannot be obtained. Further, in such a method, since the cutting bit is disposable, it is an economically disadvantageous method in a construction in which a large number of rods are used for fixing the net.

[0006] Therefore, a main object of the present invention is to provide a drilling method which is capable of drilling a hole whose inner wall is not easily collapsed even in a fragile soil site, and which is excellent in economical efficiency. It is to provide a drilling tool to be used.

[0007]

SUMMARY OF THE INVENTION The present invention relates to a drilling method for drilling a hole in the ground, wherein a slime is formed when a cylindrical drilling tool is pressed against the ground while rotating. Is pressed against the inner wall of the hole with the side surface of the drilling tool to increase the density of the inner wall of the hole. In such a drilling method, the drilling tool presses the slime against the inner wall of the hole on its side surface by eccentric rotation. Further, the present invention includes a cylindrical cutting bit having a cutting portion at the tip, and a cylindrical guide portion having substantially the same diameter as the cutting bit formed continuously with the cutting bit. A drilling tool in which a through hole for ejecting air is formed at a position deviated from a central portion at a tip end of the drilling tool. It is preferable that such a drilling tool further includes a taper coupler formed in connection with the guide portion and formed in a tapered shape so as to gradually decrease in diameter from the diameter of the guide portion. Further, the drilling tool may be formed to extend from the taper coupler and include a rod for connecting to a rock drill.

When the ground is drilled, slime, which is shavings, is generated. The slime is pressed against the inner wall of the hole by the side surface of the cylindrical drilling tool, thereby increasing the density of the inner wall of the hole. This makes the formed holes less likely to collapse. By the eccentric rotation of the drilling tool inside the hole, the side surface of the cylindrical drilling tool hits the inner wall of the hole, and slime generated by drilling is pressed against the inner wall of the hole. Thereby, the density of the inner wall of the hole is increased. In order to realize such a drilling method, a drilling tool including a cylindrical cutting bit and a cylindrical guide having substantially the same diameter as the cutting bit is used. In such a drilling tool, the ground is cut by the cutting portion at the tip, and a hole is formed. At this time, slime is pushed up between the drilling tool and the inner wall of the hole by ejecting compressed air from the tip of the cutting bit. Here, by forming a through hole for ejecting compressed air at a position deviated from the center of the tip of the cutting bit, the center of gravity of the cutting bit is positioned at a position deviated from the center line of the drilling tool. become. Therefore, when the drilling tool is rotated, the drilling tool is blurred and eccentrically rotates,
The side of the guide hits the inner wall of the hole. Thereby, the slime is pressed against the inner wall of the hole, and the density of the inner wall of the hole is increased. Furthermore, when the drilling tool is pulled out after the drilling is performed, the resistance in the pulling-out direction can be reduced due to the presence of the taper coupler. In addition, a rod is formed to extend from the taper coupler for attaching the drilling tool to the rock drill.

The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description of embodiments of the present invention with reference to the accompanying drawings.

[0010]

FIG. 1 is a plan view showing an example of a drilling tool according to the present invention, and FIG. 2 is an illustrative view showing the inside thereof. The drilling tool 10 includes a cylindrical cutting bit 12.
As shown in FIG. 3, a plurality of projecting cutting portions 14 are formed at the tip of the cutting bit 12. Cutting bit 12
Is formed of iron or the like, but the cutting portion 14 is formed of a cemented carbide. Further, a plurality of grooves 16 extending in the longitudinal direction are formed on the side surface of the cutting portion 14. A cavity 18 is formed inside the cutting bit 12, and a through hole 20 is formed from the cavity 18 toward the tip of the cutting bit 12. The through hole 20 is formed at a position off the center axis of the cutting bit 12.

A female screw portion 22 is formed in the hollow portion 18 of the cutting bit 12, and the female screw portion 22 is formed in the female screw portion 22.
The rod 26 formed with 4 is screwed. A through hole 28 is formed at the center of the rod 26, and compressed air is sent into the hollow portion 18 of the cutting bit 12 from the through hole 28 of the rod 26. Then, the compressed air sent into the cavity 18 is jetted from the through hole 20 of the cutting bit 12.

Further, the female screw portion 22 of the cutting bit 12
With this step, another female screw portion 30 is formed. The female screw portion 30 is formed to have an inner diameter larger than that of the female screw portion 22. A male screw part 34 formed on a cylindrical guide part 32 is screwed into the female screw part 30. The diameter of the guide portion 32 is formed to be substantially the same as the diameter of the cutting bit 12. A taper coupler 36 is attached so as to be continuous with the guide portion 32. The taper coupler 34 is formed in a tapered shape so as to gradually decrease in diameter from substantially the same diameter as the diameter of the guide portion 32. Inside the taper coupler 36, the female screw 3
8 is formed, and the female screw portion 38 is screwed into the male screw portion 24 of the rod 26. Thus, the cutting bit 1
2. The guide portion 32 and the taper coupler 36 are integrated, and the rod 26 is attached so as to penetrate them.

When drilling using this drilling tool 10, a rod 26 is attached to a rock drill. Then, while rotating the drilling tool 10, the tip of the cutting bit 12 is pressed against the ground so as to apply a blow,
As shown in FIG. 4, the hole is cut by the cutting unit 14. The compressed air is ejected from the through-holes 20 so that the slime, which is shavings, passes through the groove 16 and the drilling tool 10.
And the inner wall of the hole.

In the drilling tool 10, since the through hole 20 of the cutting bit 12 is formed at a position off the center, the center of gravity of the drilling tool 10 exists outside the center axis. Therefore, when the drilling tool 10 is rotated, blurring occurs, and the drilling tool 10 rotates eccentrically. Thereby, the slime that has risen between the guide portion 32 and the inner wall of the hole is pressed against the inner wall of the hole by the side surface of the guide portion 32. Thereby, the density of the inner wall of the hole is increased, and it is possible to prevent the inner wall of the hole from collapsing later.

After drilling, the drilling tool 10 is pulled out of the hole. At this time, the presence of the taper coupler 36 can reduce the resistance of the drilling tool 10 in the pulling-out direction, and facilitates pulling out. Since the hole formed by such a method has a high inner wall density and is strong, the hole is unlikely to collapse even when the drilling tool 10 is pulled out. Then, as shown in FIG. 5, a steel bar 50 having a male screw formed on the outer peripheral surface is inserted into the hole. Then, mortar is injected between the steel bar 50 and the inner wall of the hole, and the mortar is solidified, whereby the steel bar 50 is fixed. A net is fixed to the steel bar 50, and the slope of the mountain is reinforced. In addition, steel bar 5
If necessary, a support plate for holding down the ground may be attached to 0, and the support plate may be fixed with a nut, or a cap may be further covered to cover the tip of the steel bar 50.

As described above, according to the drilling method using the drilling tool 10, the inner wall of the hole can be made strong even in a fragile soil. Therefore, if the mortar is injected by inserting the steel bar 50, the mortar can be reliably poured around the steel bar 50, and the steel bar can be firmly fixed.
Further, if the drilling tool 10 is used, the drilling tool 1 is drilled after drilling.
0 can be extracted, which is more economical than the conventional method in which the cutting bit is disposable. Further, the drilling tool 10 can be used by attaching the rod 26 to a small rock drill, and it is not necessary to form a scaffold as in the case of using a large rock drill, and the surrounding trees are cut down. No need. Therefore, it can also help protect forest resources.

In this cutting tool 10, a through hole 20 is formed at a position deviated from the center of the cutting bit 12 in order to eccentrically rotate the drilling tool 10, whereby the through hole 20 is always formed. It is possible to obtain the effect that the slime is hardly clogged in the through hole 20 because of the movement. Also,
The configuration of each part can also be changed according to the conditions of the place to be drilled. For example, in a place where the soil is brittle, by increasing the length of the guide portion 32, the slime can be pressed against the inner wall of the hole in a wide range, and a strong inner wall can be obtained. Also, in places where the soil is relatively hard,
As shown in (1), the shape of the cutting portion 14 of the cutting bit 12 can be made cross-shaped or the like to facilitate drilling. Further, in a place where there is a root of a tree, the drilling can be efficiently performed by forming the cutting portion 14 that cuts the root.

[0018]

According to the present invention, a hole having a strong inner wall can be formed even in a soil fragile place. Therefore, if a bar is inserted into a hole formed by using this drilling tool and mortar is injected, the bar can be securely fixed. Moreover, the drilling tool can be pulled out without collapsing the hole, and there is no need to dispose of the drilling tool, which is excellent in economical efficiency. Furthermore, the length of the guide portion and the type of cutting bit can be changed in accordance with the soil properties, so that it can be adapted to drilling on any land.

[Brief description of the drawings]

FIG. 1 is a plan view showing an example of a drilling tool of the present invention.

FIG. 2 is an illustrative view showing the inside of the drilling tool shown in FIG. 1;

FIG. 3 is a perspective view showing an example of a cutting bit used in the drilling tool shown in FIG.

FIG. 4 is an illustrative view showing a state of drilling using the drilling tool shown in FIG. 1;

FIG. 5 is an illustrative view showing a state where a steel bar is inserted into a hole formed by the drilling method of the present invention.

FIG. 6 is a perspective view showing another example of a cutting bit used in the drilling tool of the present invention.

FIG. 7 is an illustrative view showing slope reinforcement of a mountain;

FIG. 8 is an illustrative view showing a state of drilling using a conventional drilling tool.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Drilling tool 12 Cutting bit 14 Cutting part 16 Groove 18 Cavity part 20 Through hole 26 Rod 32 Guide part 36 Taper coupler

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Koichi Ogura, Inventor Daiichi Co., Ltd. 2-3-9 Koraibashi, Chuo-ku, Osaka-shi

Claims (5)

[Claims] 1. A boring method for boring a ground, wherein a slime is applied to a side surface of the boring tool when the boring tool is pressed against the ground while rotating a cylindrical boring tool. A drilling method in which the density of the inner wall of the hole is increased by pressing the inner wall of the hole. 2. The drilling tool according to claim 1, wherein the slime is pressed against the inner wall of the hole by eccentric rotation.
3. The drilling method according to 1. 3. A cutting tool comprising: a cylindrical cutting bit having a cutting portion at a tip; and a cylindrical guide portion having a diameter substantially equal to that of the cutting bit formed continuously with the cutting bit; A drilling tool in which a through hole for ejecting air is formed at a position deviated from a central portion of a tip end of a drill bit. 4. The drilling tool according to claim 3, further comprising a taper coupler formed to be continuous with the guide portion and tapered so as to gradually decrease in diameter from the diameter of the guide portion. . 5. The drilling tool according to claim 4, further comprising a rod formed to extend from the taper coupler and connecting to a rock drill.