JPH05321554A - Horizontal hole drilling device - Google Patents

Abstract

PURPOSE:To make a straight horizontal hole in orderly manner by deviating to center of a drilling bit from the center of a sleeve pipe and rotating a rotary shaft supported rotatively in the sleeve pipe and shielding forward. CONSTITUTION:Each roller 17 is designed to be different in diameter so that the diameter of the roller 17 located in the lower part L of a sleeve 12 which is pushed into a horizontal hole C drilled and formed with a bit 13, thereby forming a primary inner wall which may be larger than the diameter of the roller 17 located on the upper part H. The center of a circle formed on a receiving plane of each roller 17 is slightly upwardly deviated from the center P2 of the sleeve 12 and supported rotatively under this slightly deviated condition. When a central axis 11 is rotated, a rotary center P1 of the bit 13 is deviated from the center P2 of the sleeve pipe. The bottom side of the sleeve is virtually equivalent to the outside diameter of the sleeve. Further-more, a disk-shaped horizontal hole, which is deviated from the sleeve pipe, is straightly excavated so that the other parts may be slightly larger-sized than the outside diameter of the sleeve pipe.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a horizontal hole excavating device for excavating ground, rock, etc. to make a horizontal hole in the ground.

[0002]

2. Description of the Related Art Conventionally, as one of the methods for digging a horizontal hole in the ground, a horizontal hole is formed by excavating the ground etc. with an excavating bit.
A method of pushing the sheath tube while adding the sheath tube into the hole is generally adopted.

As a conventional horizontal hole excavating device of this type, for example, a device as shown in FIG. 9 is known. As shown in the same figure, this conventional device has a cylindrical rotary shaft 1 rotated by an actuator (not shown), a drill bit 2 attached to the tip of the rotary shaft 1, and a rotary shaft 1 fitted on the rotary shaft 1. It has a sheath tube 4 (also referred to as a casing) rotatably supported by a bearing 3 provided on the outer peripheral surface of the rotating shaft 1, and an arbitrary number of excavating claws 5 are attached to the front surface of the bit 2. Then, the rotary shaft 1 is rotated to excavate the ground, and the sheath pipe 4 is pushed into the excavated lateral hole for construction. Further, the rotary shaft 1 and the sheath tube 4 are constructed in a replenishing type. Also, the claw 5 of the bit 2
Of these, the outermost excavation claw 5a is configured to rotate with a diameter slightly larger than that of the sheath tube 4 for excavation and to facilitate pushing of the sheath tube 4. Furthermore, in the conventional device, the sheath tube 4 is attached to the rotary shaft 3
It is fitted concentrically with.

[0004]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention The above-mentioned conventional device is a sheath tube 4
Since the rotating shaft 3 is fitted concentrically with the rotating shaft 3, when the bit 2 is rotated by the rotating shaft 3, as shown in FIG. The lateral hole A will be formed. Then, as described above, the sheath tube 4
Further, the rotating shaft 1 is sequentially added and pushed into the hole A, but the weight of the sheath pipe 4 and the rotating shaft 1 causes the sheath pipe 4 to come into contact with the bottom surface of the inner wall of the hole. Therefore, when excavating in this state, as shown in FIG.
The stepped portion B is formed at the boundary between the newly formed hole A ₁ and the newly formed hole A _1, and as a result, the lateral hole A is not constructed straight. Therefore, in the past, various modifications were made so that the holes would be straight, and the work was carried out while making corrections, but it was virtually impossible to correct the holes so that they were completely straight.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a horizontal hole excavating device which can dig a straight horizontal hole in an orderly manner without any correction work.

[0006]

In order to achieve the above object, a horizontal hole excavating device according to the present invention has a cylindrical rotating shaft, an excavating bit attached to the tip of the cylindrical rotating shaft, and a rotary shaft fitted to the rotating shaft. A sheath pipe, and the rotation center of the drill bit is eccentric with the center of the sheath pipe, and the rotation shaft is rotatably supported in the sheath pipe. ..

[0007]

According to the present invention, since the center of the rotary shaft and the center of the sheath pipe are eccentric, when the rotary shaft is rotated, the lower surface side of the sheath pipe substantially coincides with the outer diameter of the sheath pipe, and A circular lateral hole eccentric to the sheath pipe is excavated so that the diameter of the other portion is slightly larger than the outer diameter of the sheath pipe (see FIGS. 3 and 7). Therefore, as shown in FIG. 8B, the holes are dug in an orderly and straight manner.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a horizontal hole excavating device according to the present invention will be described below with reference to the drawings. FIG. 1 is a vertical cross-sectional view of the excavating device according to this embodiment, showing a state in which a cylindrical body to which the outermost excavating claw is attached is opened, and FIG. 2 is a vertical sectional view of the same device. The figure which shows the state which closed the cylindrical body of the outermost excavation nail, FIG. 3 is the sectional view on the I-I line of FIG. 1, and is a figure which shows the positional relationship of a sheath tube and a cylindrical rotating shaft, FIG. 1 is a cross-sectional view taken along line BB of FIG. 1, FIG. 5 is a longitudinal side view of the sheath pipe, FIG. 6 is a front view showing a part of the sheath pipe in an enlarged manner, and FIG. FIG. 8 is an explanatory diagram showing the relationship between the present invention device and the conventional device in comparison with the state of formation of a lateral hole to be excavated.

1 to 8, the horizontal hole excavating device of this embodiment includes a cylindrical rotary shaft 11 rotated by an actuator (not shown), and a drill bit 13 attached to the tip of the rotary shaft 11. , And a sheath tube 12 (casing) fitted to the rotary shaft 11.

The cylindrical rotary shaft 11 rotates the excavating bit 13 attached to the tip thereof together with the rotary shaft 11, is formed to have a desired diameter and length, and is constructed as an addition type. The earth and sand and crushed stones excavated by the bit 13 are
In the embodiment, a round bar spiral 14 is provided on the inner wall surface of the rotary shaft 11 as the discharging means so that earth and sand or the like can be transferred backward by the conveyor action of the spiral 14. Configured. In addition,
This discharging means can be changed to a screw blade or any other structure.

The sheath tube 12 is for being pushed into a lateral hole C formed by excavating with a bit 13 to construct a primary inner wall of the lateral hole C. The sheath tube 12 is formed to have a length corresponding to that of the rotating shaft 11, and is rotated. Similar to the shaft 11, it is configured to be an extension type. Therefore, in the present invention, the rotation center P ₁ of the bit 13 is eccentric with the center P ₂ of the sheath tube (see FIGS. 3 and 7) so that the rotary shaft 11 is rotatable in the sheath tube 12. It is configured to be supported by the sheath tube 12 in the embodiment.
A roller bearing 15 in which a plurality (16 in the figure) of rollers 17 are rotatably mounted between a pair of annular bearing plates 16 and 16 fitted in each other. Fixed to the inner wall surface of both ends of the sheath tube 12 by means,
Each of the rollers 17 has a diameter difference. That is, as shown in FIG. 3, the roller 17 located on the lower L side of the sheath tube 12 and the roller 17 located on the upper H side of the sheath tube 12.
The diameter of each roller 17 is set to be lower> upper, so that each roller 17 has a diameter difference so that the center of the circle formed by the receiving surface of each roller 17 is located slightly above the center P _{2 of the} sheath tube 12. It is eccentric. As a result, the rotary shaft 11 is rotatably supported with its center slightly eccentric to the center of the sheath tube. Therefore, when the rotary shaft 11 is rotated, the rotation center P ₁ of the bit 13 is eccentric with the center P _{2 of the} sheath tube 12.

In the embodiment, as described above, the roller bearing 1
Although the structure in which the rotary shaft 11 is rotatably supported is disclosed in 5, the bearing means for rotatably supporting the rotary shaft 11 is not limited to the roller bearing 15. The rollers 17 are formed to have the same diameter,
The shaft mounting position of each roller 17 with respect to the bearing plates 16 and 16 is displaced so that the center of the circle formed by the receiving surface of each roller 17 is eccentric with the center P _{2 of the} sheath tube 12, or a roller bearing. The bearing bush (metal) may be provided in place of 15, and the configuration can be changed to any configuration. The point is that the center of the rotary shaft 11 and the center of the sheath pipe 12 are eccentric so that the rotary shaft 11 is placed inside the sheath pipe 12. It may be configured so as to be rotatably supported. Reference numeral 19 is a ring fixed to the tip of the sheath tube 12, and a conical surface 20 is formed on the inner wall surface of the tip of the ring 19. The ring 19 is provided to move the divided cylinder unit to which the outermost claw of the drill bit 13 is attached in the closing (diameter reducing) direction, and the details will be described later. Further, the ring 19 is provided on the sheath tube 12 fitted to the rotary shaft 11 to which the bit 13 is attached, and does not need to be provided on the additional sheath tube.

Drilling bit 1 attached to the tip of the rotating shaft 11.
Reference numeral 3 is for integrally excavating the ground or the like on the excavation surface by rotating integrally with the rotary shaft 11, and the type and structure of the bit 13 are not particularly limited and can be freely designed, but the horizontal hole to be excavated. Since the sheath tube 12 is pushed into C, the rotation circular locus of the outermost drilling claw, that is, the diameter of the hole C is set to be slightly larger than the outer diameter of the sheath tube, and the sheath tube is inserted. To facilitate. The excavating bit 13 of the embodiment has a central cylindrical body 21 provided at the center of the tip of the cylindrical rotary shaft 11 and an arbitrary number (two in the figure) of cylindrical bodies fitted with a gap 22 formed in the cylindrical body 21. 23 and 24 and a cylindrical body 25 fitted to the cylindrical body 24
The central cylindrical body 21 and the cylindrical bodies 23, 24 are welded to each other through the mounting plates 26, 27 arranged radially, and are fixed to the inner wall surface of the rotary shaft 11, and the cylindrical bodies 23, 24 Arbitrary numbers of excavating claws 28, 29 are detachably attached to the tip end side of the with bolts (not shown). Then, the gap 22
This constitutes a transfer passage for sending earth and crushed stones later.

As shown in detail in FIG. 4, the outermost cylindrical body 25 is composed of a divided cylinder single body 25a obtained by dividing the cylindrical body 25 into a plurality (six in the figure), and each cylinder single body 25a is a center. Six sliding plates 31 which are slidable through the through holes 30 provided in the cylindrical body 21 and the cylindrical body 24 and are radially arranged.
The diameter of the cylindrical body 25 is fixed by welding or the like to the distal end of the cylindrical body 25, and the diameter of the cylindrical body 25 is enlarged or reduced. And the cylindrical bodies 24, 25 when enlarged
A gap 32 for the transfer passage is formed therebetween. Of the divided cylinders 25a constituting the cylindrical body 25, an excavation claw 33 is detachably attached to the tip side of any number of the cylinders 25a by bolts, and during excavation rotation, that is, when the cylindrical body 25 is expanded. When the rotary shaft 11 is rotated in the above, the rotation circular locus (diameter of the hole C) of the excavation claw 33 is changed to the sheath tube 12.
The outer diameter is substantially the same as the outer diameter on the lower L side, and the other portions are set to have a diameter slightly larger than the outer diameter of the sheath tube. With this configuration, when the diameter of the cylindrical body 25 is expanded and rotated, the sheath tube 12
Since the horizontal hole C is excavated without forming a gap on the lower side of the sheath tube, the sheath tube does not lower due to the weight of the sheath tube 12 and the rotary shaft 11 unlike the conventional device. Therefore, FIG.
As shown in, the straight lateral hole C is dug while advancing the sheath tube.

The conical surface 20 of the ring 19 of the sheath tube 12 is provided on the outer wall surface of the rear end of each of the divided cylinders 25a of the cylindrical body 25.
A taper acting surface 34 that engages with is formed. As a result, when the rotary shaft 11 is pulled rearward in a state where the cylindrical body 25 is enlarged (the state shown in FIG. 1), each single cylinder 25a moves in a direction in which the taper acting surface 34 slides on the conical acting surface 20 and contracts. Therefore, the sliding plate 31 integrated with this also slides in synchronization (see FIG. 2).

The actuating rod 35 is non-rotatably and axially slidably fitted into the central cylindrical body 21, and the rear end of the actuating rod 35 is formed into a conical surface 36. 36 is abutted against the inclined surface 37 formed at the base end of each sliding plate 31. In the embodiment, the inner wall surface of the central tubular body 21 and the outer wall surface of the operating rod 35 are polygonal (hexagonal in the figure, see FIG. 4).
It is formed so as to be engaged with each other to prevent movement of the operating rod 35 in the rotational direction. A mounting cylinder 38 is fixed to the tip of the operating rod 35 by welding or the like, and an excavating claw 39 is detachably mounted to the tip of the cylinder 38 with a bolt. Reference numeral 40 denotes a stopper member provided at the base end of each sliding plate 31, and this stopper member 40 is provided to limit the movement of the sliding plate 31 in the expanding direction. With the above configuration, when the rotary shaft 11 is pushed while rotating the cylindrical body 25 in a reduced diameter state, the excavation claw 39 at the center collides with the excavation surface and retracts due to the reaction force, so that each sliding plate 31 is moved. Is pressed by the conical surface 36 of the operating rod 35 and slides in the expanding direction to expand the diameter of the cylindrical body 25.

When the drill bit 13 is constructed as in the embodiment, the outermost cylindrical body 25 is reduced in diameter so that the sheath tube 1
Although it is possible to pull out the rotary shaft 11 and the excavation bit 13 by leaving 2 in the hole C, the cylindrical body 25 may be configured as a fixed type (impossible to expand / reduce diameter), and as described above. As described above, the configuration itself of the bit 13 can be freely changed.

[0018]

According to the present invention, the holes can be prevented from being bent irregularly, and a straight lateral hole can be dug in an orderly manner.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an embodiment of a horizontal hole excavating device according to the present invention, showing a state in which a cylindrical body having an outermost excavating claw attached thereto is used.

FIG. 2 is a vertical cross-sectional view of the same apparatus, showing a state in which the cylindrical body to which the outermost excavating claw is attached is closed.

3 is a cross-sectional view taken along the line I-I of FIG. 1, showing the positional relationship between the sheath tube and the cylindrical rotation shaft.

FIG. 4 is a sectional view taken along line BB of FIG.

FIG. 5 is a vertical sectional side view of a sheath tube.

FIG. 6 is a front view showing a part of the sheath tube in an enlarged manner.

FIG. 7 is an explanatory view showing a relationship between a lateral hole to be drilled by a drill bit and a sheath pipe.

FIG. 8 is an explanatory view showing the state of formation of a lateral hole excavated by the device of the present invention and the conventional device in comparison.

FIG. 9 is a vertical sectional view showing a conventional horizontal hole excavating device.

FIG. 10 is an explanatory view showing a lateral hole to be excavated by a conventional device in association with a sheath pipe.

[Explanation of symbols]

11 Cylindrical Rotation Shaft 12 Sheath Pipe 13 Excavation Bit 15 Roller Bearing 28, 29, 33, 39 Excavation Claw C Side Hole P ₁ Center of Rotation of Excavation Bit P ₂ Center of Sheath Pipe

Claims (1)

[Claims] 1. A cylindrical rotating shaft, an excavating bit attached to the tip of the cylindrical rotating shaft, and a sheath pipe fitted to the rotating shaft, wherein the center of rotation of the excavating bit is eccentric with the center of the sheath pipe. The horizontal hole excavating device is characterized in that the rotating shaft is rotatably supported in the sheath pipe.