JPH08144677A - Excavating tool and ring bit - Google Patents

Abstract

PURPOSE: To avoid troubles that the ground can not be excavated because sands and earth or fragments of rock accumulate between the inner wall surface of an excavated hole and an outer pipe is secured to the ground. CONSTITUTION: In an excavation tool 100, a through hole 57 is provided through a ring bit 50 attached to the forward end of an outer pipe 10, and hence sands and earth or fragments of rock accumulating between the inner wall surface 4 of an excavated hole 2 and the outer pipe 10 are drawn into a gap 43 between the outer pipe 10 and an inner pipe 20 through the hole 57 together with high pressure water fed through the inner pipe 20. As a result, sands and earth or fragments of rock are prevented from accumulating into between the inner wall surface 4 of the hole 2 and the pipe 10 so that a trouble that the outer pipe 10 is fixedly secured to the ground 1 and the ground 1 can not be excavated can be avoided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drilling tool for drilling holes by drilling ground or rock.
The present invention relates to improvement of a double pipe type drilling tool.

[0002]

2. Description of the Related Art Conventionally, various excavating tools have been used to excavate the ground or rock to make holes.
Among them, a bit for excavation is attached to each tip, and an inner pipe and an outer pipe which are coaxial with each other and which are adapted to excavate a hole by receiving a rotational force about an axis and a striking force in an axial direction are provided. In addition, the excavated earth and sand or debris is made to flow together with the fluid supplied through the inner pipe in the gap between the inner pipe and the outer pipe and discharged to the outside of the excavated hole. There is a so-called double pipe type drilling tool.

An example of such a double pipe type drilling tool is shown in FIG.
The double pipe type drilling tool 90 has an outer pipe 10 and an inner pipe 20 which are coaxial with each other. The outer tube 10
Is a tubular member in which a tubular ring bit 11 for excavating the ground 1, a tubular outer casing 12, and also a tubular casing coupling 13 are integrally screwed together, and the base end thereof is integrated with the cleaning adapter 30. Is screwed to. The inner pipe 20 has an inner bit 21.
And inner rod 22, and inner coupling 2
3 is a tubular member integrally screwed to the extension rod 24, which is coaxially arranged inside the outer tube 10 and whose base end is integrally screwed to the cleaning adapter 30. There is. The cleaning adapter 30 is integrally screwed with a shank rod 35 to which a rotational force about an axis and a striking force in an axial direction are applied by a driving device (not shown).
And the cleaning adapter 3 is attached to the inner pipe 20.
The rotational force about the axis C and the striking force in the direction of the axis C are applied via 0 respectively. This allows
The ring bit 11 and the inner bit 21 attached to the tips of the outer pipe 10 and the inner pipe 20, respectively.
However, the ground 1 is excavated by the rotational force around the axis C and the striking force in the direction of the axis C to form the hole 2.

A water swivel 40 is attached to the outer periphery of the cleaning adapter 30 so as to be rotatable relative to the axis C. The high-pressure water A introduced from the water inlet pipe 45 of the water swivel 40 passes through the passage 41 inside the water swivel 40 and the passage 42 inside the inner pipe 20 to excavate the ground 1 to form a hole. Two
It is designed to be ejected toward the bottom portion 3 of the. The high-pressure water jetted to the bottom portion 3 of the hole 2 mixes with the sand and debris generated by excavation, and is attached to the water swivel 40 through the gap 43 between the outer pipe 10 and the inner pipe 20. It reaches the inside of the drain pipe 46 and is discharged as the slime B to the outside of the hole 2.

[0005]

By the way, the above-mentioned 2
In the heavy pipe type drilling tool 90, the outer diameter of the ring bit 11 attached to the tip of the outer pipe 10 is larger than the outer diameter of the outer casing 12 constituting the outer pipe 10. The outer peripheral surface is designed not to contact the inner wall surface 4 of the excavated hole 2. However, when the ground 1 to be excavated is likely to collapse, the inner wall surface 4 of the hole 2 drilled due to vibration of the excavation and the like gradually collapses, and the earth and sand are deposited between the inner wall surface 4 of the hole 2 and the outer peripheral surface of the outer pipe 10. And debris 5 gradually accumulates. Since the earth and sand and debris 5 do not move around the tip of the ring bit 11 into the gap 43 between the outer pipe 10 and the inner pipe 20, they are supplied through the inner pipe 20. It cannot be removed with high pressure water A. Also, these sediments and debris 5
Is trying to adhere to the outer peripheral surface of the outer tube 10 due to the pressure of the ground 1, so most of the rotational force around the axis C and the impact force in the direction of the axis C applied to the outer tube 10 are mostly the outer tube 10 and the earth and sand or debris. 5
Is consumed by friction with the outer pipe 10, and in the worst case, the outer pipe 10 sticks to the ground 1 and the ground 1 cannot be excavated.

Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to deposit sediment or debris between the inner wall surface of the bored hole and the outer pipe. Another object of the present invention is to provide an excavating tool in which the outer pipe is fixed to the ground and the ground cannot be excavated.

[0007]

The above object of the present invention is to excavate a hole in which bits for excavation are attached to the tips of the present invention, and a rotational force about an axis and a striking force in an axial direction are received. The inner pipe and the outer pipe are coaxial with each other, and earth and sand or debris generated by excavation, between the inner pipe and the outer pipe together with the fluid supplied through the inner pipe. A drilling tool that is adapted to flow in a gap and be discharged to the outside of a drilled hole, in an annular ring bit attached to the tip of the outer pipe,
This can be achieved by a drilling tool characterized in that a through hole extending between an outer peripheral surface facing the inner wall surface of the hole to be drilled and an inner peripheral surface facing the inner pipe is provided.

[0008]

In the excavating tool of the present invention, the earth and sand and debris accumulated between the inner wall surface of the excavated hole and the outer pipe penetrates the ring bit together with the fluid supplied through the inner pipe. It flows into the gap between the outer pipe and the inner pipe through the through hole and is discharged to the outside of the drilled hole. As a result, sediment and debris can be prevented from accumulating between the inner wall surface of the excavated hole and the outer pipe, so that the rotational force around the axis and the impact force in the axial direction applied to the outer pipe can be prevented. It is not consumed by friction between the pipe and the earth and sand or debris, which reduces the excavation speed or makes it impossible to excavate.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a drilling tool according to the present invention will be described in detail below with reference to the drawings. Here, FIG. 1 is a half cross-sectional side view for explaining the operation of the drilling tool according to the present invention, and FIG. 2 is a half cross-sectional side view of the ring bit shown in FIG. In addition,
The drilling tool of the present embodiment is characterized in that a through hole is provided through the ring bit, and the configuration of the other parts is the same as that of the conventional drilling tool described above, and therefore, a characteristic part in the following description. Will be described in detail. Further, the same parts as those of the conventional excavating tool are designated by the same reference numerals, and the description thereof will be omitted.

As shown in FIG. 1, a drilling tool 1 according to the present embodiment.
00 includes an outer tube 10 and an inner tube 20 which are coaxial with each other, and a ring bit 50 is provided at a tip portion of the outer tube 10.
Is attached.

As shown in FIG. 2, the ring bit 50 has a small diameter portion 5 on which an external thread 52 is screwed on the outer peripheral surface thereof.
1 and a large diameter portion 56 in which a plurality of button tips 54 are planted on the tip surface thereof. And the large diameter portion 5
3, a plurality of through holes 57 extending between the outer peripheral surface 56 and the inner peripheral surface 57 are provided at equal intervals in the circumferential direction. The through hole 57 is provided so as to be inclined with respect to the axis C so that the opening on the outer peripheral surface side approaches the tip side of the large diameter portion 53. Further, the through hole 5 is formed in the outer peripheral surface 56.
A concave groove 58 extending in the axial direction toward 7 is provided.

Next, the operation of the excavating tool 100 of this embodiment will be described with reference to FIG. The rotating force around the axis C and the striking force in the direction of the axis C are transmitted to the ring bit 50 of the outer pipe 10 of the excavating tool 100 via the outer casing 12 that is integrally screwed by the male screw 52. As a result, the ring bit 50 excavates the ground 1 with the plurality of button tips 54 attached to the tip. Similarly, the rotating force around the axis C and the striking force in the axis C direction are transmitted to the inner bit 21 attached to the tip of the inner tube 20 via the inner rod 22 that is integrally screwed, Therefore, the inner bit 21 is grounded by a plurality of chips 21a attached to the tip.
To drill.

The high-pressure water supplied into the passage 42 provided inside the inner pipe 20 flows as shown by an arrow C in FIG. 1 and is jetted to the bottom 3 of the hole 2 to be excavated. Bottom 3
The high-pressure water ejected inside flows radially outward between the tips 21a of the inner bit 21 and becomes integrated with the earth and sand, debris, etc. excavated by the inner bit 21 and the ring bit 50. Outer tube 10 and inner tube 20
Flows into the passage 43 between. And the passage 43
It flows through the inside in the axial direction upward in the figure, and is eventually discharged to the outside of the hole 2.

On the other hand, a part of the high pressure water jetted into the bottom portion 3 of the hole 2 is inserted between the button tip 54 planted at the tip of the ring bit 50 and the inner wall surface 4 of the hole 2 and the ring bit 50. Between the inner wall surface 4 of the hole 2 and the ring bit 50 and the outer casing 12, and mixes with earth and sand and debris. Then, it flows out into the passage 43 through the through hole 57 penetrating the ring bit 50. At this time, a negative pressure is generated in the through hole 57 of the ring bit 50 due to the high-pressure water flowing through the passage 43, so that a negative pressure is accumulated between the inner wall surface 4 of the hole 2 and the ring bit 50 and the outer casing 12. The earth and sand and debris that have accumulated are surely sucked into the passage 43 through the through hole 57. In addition, in the ring bit 50 of the present embodiment, the through hole 57 has an opening on the outer peripheral surface side that is the large diameter portion 53.
Of the ring bit 50 and the outer peripheral surface 5 of the ring bit 50.
6 has a groove 58 extending in the axial direction toward the through hole 57.
Is recessed. As a result, the earth and sand and debris accumulated between the inner wall surface 4 of the hole 2 and the outer peripheral surface 56 of the ring bit 50 smoothly flow into the through hole 57 and the passage 43
Spills in.

That is, in the excavating tool 100 of this embodiment, the earth and sand and debris accumulated between the inner wall surface 4 of the hole 2 and the ring bit 50 and the outer casing 12 are pierced by the ring bit 50. Through the through hole 57,
It flows out into the passage 43 between the outer pipe 10 and the inner pipe 20, and is discharged to the outside of the hole 2 together with the high-pressure water supplied via the inner pipe 20. As a result, it is possible to prevent sediment and debris from accumulating between the inner wall surface 4 of the hole 2 and the outer pipe 10, so that the rotational force about the axis and the impact force in the axial direction applied to the outer pipe are applied. It is not consumed by friction between the outer pipe and the earth and sand or debris, and the excavation speed is not reduced or the excavation cannot be stopped.

It is needless to say that the excavating tool 100 of the present invention is not limited to the above-mentioned embodiment and various modifications can be made based on the gist of the present invention. For example, in the above-described embodiment, the inner wall surface 4 of the hole 2 is formed by forming the through hole 57 in the ring bit 50.
The sand and debris between the outer pipe 10 and the outer pipe 10 are discharged into the passage 43 between the outer pipe 10 and the inner pipe 20, but the ring bit 50 constituting the outer pipe 10 such as the outer casing 12 is used. If the through holes are provided in other members as well, the earth and sand and debris between the inner wall surface 4 of the hole 2 and the outer pipe 10 can be discharged more efficiently. Further, it is easy for those skilled in the art to appropriately set the shape, the number, the position, etc. of the through holes penetrating the ring bit 50, the outer casing 12, and the like.

[0017]

That is, the excavating tool of the present invention has a bit for excavation attached to the tip thereof and is coaxial with each other so as to excavate by receiving a rotational force about the axis and a striking force in the axial direction. A hole having an inner pipe and an outer pipe, excavated earth and sand or debris, etc. by flowing in the gap between the inner pipe and the outer pipe together with the fluid supplied through the inner pipe. Of an excavating tool that is adapted to be discharged to the outside of the outer pipe, the annular ring bit being attached to the tip of the outer pipe, the outer peripheral face facing the inner wall surface of the hole to be excavated, and the inner pipe facing the inner pipe. Since a through hole extending between the inner surface and the inner surface is provided, the sediment and debris accumulated between the inner wall surface of the excavated hole and the outer pipe will not be discharged along with the fluid supplied through the inner pipe. The outer pipe and the inner pipe are connected to each other through the through holes that are provided in the ring bit. Sucked into the gap between, it is discharged to the outside of the drilled hole. As a result, sediment and debris do not accumulate between the inner wall surface of the excavated hole and the outer pipe, so the rotational force about the axis and the impact force in the axial direction applied to the outer pipe accumulate with the outer pipe. It is not consumed by sand, debris, or friction with the ground. Therefore, the rotational force around the axis and the striking force in the axial direction applied to the outer pipe are surely transmitted to the ring bit attached to the tip of the outer pipe, so that the ground can be efficiently ground without reducing the excavation speed. Holes can be drilled and drilled.

[Brief description of drawings]

FIG. 1 is a half sectional side view for explaining the operation of an excavating tool according to one embodiment of the present invention.

2 is a half sectional side view of the ring bit shown in FIG. 1. FIG.

FIG. 3 is a side view of an entire half section of a conventional drilling tool.

FIG. 4 is a half sectional side view showing an enlarged main part of the excavating tool shown in FIG.

[Explanation of symbols]

 1 Ground 2 Holes 3 Bottom of Hole 4 Inner Wall Surface of Hole 5 Sediment or Rock Debris 10 Outer Tube 11 Ring Bit 12 Casing 13 Casing Coupling 20 Inner Tube 21 Inner Bit 22 Inner Rod 23 Inner Coupling 24 Extension Rod 30 Cleaning Adapter 35 shank rod 40 water swivel 41 water swivel inner passage 42 inner pipe inner passage 43 gap between outer pipe and inner pipe 45 water inlet pipe 46 drainage pipe 50 ring bit 51 according to the present invention small diameter portion 52 male screw 53 large diameter portion 54 button tip 55 Inner peripheral surface 56 Outer peripheral surface 57 Through hole 90 Conventional drilling tool 100 Drilling tool according to the present invention

Claims (4)

[Claims] 1. An inner pipe and an outer pipe, which are coaxial with each other, having a bit for excavation attached to the tip thereof and adapted to excavate a hole by receiving a rotational force about an axis and a striking force in an axial direction. And discharges the earth and sand or debris generated by excavation to the outside of the excavated hole by causing the fluid supplied through the inner pipe to flow in the gap between the inner pipe and the outer pipe. In the drilling tool that is made, in the annular ring bit attached to the tip of the outer pipe,
A drilling tool, wherein a through hole extending between an outer peripheral surface facing an inner wall surface of a hole to be drilled and an inner peripheral surface facing the inner pipe is provided. 2. An inner tube and an outer tube which are coaxial with each other and have a bit for excavation attached to the tip thereof and are adapted to excavate a hole by receiving a rotational force about an axis and a striking force in an axial direction. And discharges the earth and sand or debris generated by excavation to the outside of the excavated hole by causing the fluid supplied through the inner pipe to flow in the gap between the inner pipe and the outer pipe. In the drilling tool as described above, a through hole is provided through the outer pipe. 3. The excavating tool according to claim 1, wherein the rotation directions of the inner pipe and the outer pipe about the axis line are different from each other. 4. An annular ring bit used for the drilling tool according to claim 1, wherein the through hole extends between the inner peripheral surface of the outer peripheral surface of the hole facing the inner wall surface of the hole to be drilled. A ring bit characterized by being pierced.