JPH0433358B2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field] This invention relates to a drilling device, and in particular to a drilling device used for driving steel pipes for reinforcing the ground such as tunnels. By drilling a hole with a diameter larger than that of the pipe, drilling the hole and inserting the pipe at the same time, and making the diameter of the drilling bit smaller than the inner diameter of the pipe when the hole is finished. This relates to a drilling device whose main purpose is to make it possible to pull out only the drilling device (bit rod, etc.) from the inside of the pipe, leaving the pipe.

[Prior art] When excavating tunnels in poor ground, the top of the face was protected using seamed sheet piles, but in recent years the top of the face has been protected by driving lock bolts or steel pipes. This is done by

By the way, when driving a steel pipe, as shown in FIG. The second bit 5 has a larger diameter than the steel pipe.
With the steel pipe 3 fitted around the outer periphery of the drilling rod 2, the ground 6 is excavated, and when the steel pipe 3 is inserted into the ground, the second bit 5 is deformed so as to reduce its outer diameter. A method of working in which a drilling rod with the first and second bits attached to the tip is pulled out while the steel pipe is left in the pile, i.e., the drilling rod is inserted into the steel pipe during excavation and the diameter of the steel pipe is larger than the outer diameter of the steel pipe. A drilling method that is capable of drilling a hole and simultaneously drilling the hole and inserting the steel pipe by pulling out the drilling rod from the steel pipe at the end of drilling has been considered, but there is no equipment that can reliably perform this method. The current situation is that it cannot be found.

[Problems to be solved by the invention] This drilling device is a device that drills holes by impact and rotation, and the diameter of the hole is approximately 50 mm. is several 10Kgf/ ^mm2 , and the rotational force is also several 10Kgf
In addition, crushed rock particles (hereinafter referred to as chips) flow violently together with water, so each member is required to withstand these forces and function reliably.

[Means for Solving the Problems] The present invention solves the above-mentioned problems, and the drilling device of the present invention has a rod sleeve.
It consists of a first bit and a second bit, each of which is configured as follows.

(1) Rod The front part of the rod has a tsuba, and the cross section at the tip of the tsuba is square (triangular, polygonal, or spline).
A slit is provided at the tip of the square cross section, and a hook is provided at the tip of the slit.

(2) Sleeve The sleeve that fits into the polygons of the rod, cannot rotate mutually, and can move forward in the axial direction is provided with a slit opposite to the slit of the rod, and the outer periphery of the rear end surface of the slit is provided with a slit. Protrusions are provided,
There is an external thread at the tip of the sleeve.

(3) 1st bit The 1st bit for drilling the center hole has an internal thread that engages with the thread at the tip of the sleeve, and a relief part without a thread is provided at the entrance of the thread.

(4) Second bit The second bit for hole expansion is plate-shaped and has a protrusion with a slope in front of the blade surface.

It is an object of the present invention to provide a drilling device having the above-mentioned configuration, which can simultaneously perform drilling and inserting a steel pipe, and also ensure that the drilling rod can be pulled out from the steel pipe after drilling. It is.

[Examples] The present invention will be explained below using examples shown in the drawings. FIG. 1 is a sectional view showing the configuration of the tip portion of the drilling device according to the present invention, and FIGS. 2 a, b, and c are sectional views taken along lines AA, BB, and C-C in FIG. 1, respectively. , Fig. 3 is a view similar to Fig. 1, and is a cross-sectional view showing a state in which the tip portion is reduced so that the drilling bit can pass through the steel pipe, and Fig. 4 is a cross-sectional view showing the state in which the drilling bit can pass through the steel pipe.
It is a sectional view taken along the line B'.

In the drawing, the description of the rock drill body is omitted, but this rock drill body is constructed to impact and rotate the drilling rod 7 in the same way as the conventional rock drill body shown in FIG. . In this embodiment, the drilling rod 7 has a hexagonal cross section, and a circular flange 8 is formed near the tip, which serves as a positioning member behind the sleeve 9 that is fitted into the tip. A sleeve 9 is supported in which a groove 12 is provided so that the tip of a hook plate 11 fixed to a slit 10 at the tip of the drilling rod 7 can pass therethrough.

The sleeve 9 is provided with a slit 13 similar to the slit 10 of the drilling rod.
3 is longer than the slit 10 of the drilling rod, and a plate-shaped second bit 5 can be inserted into this slit 13. Furthermore, an external thread 14 is formed at the small-diameter tip of the sleeve 9, into which a first bit 4 having an outer diameter approximately the same as the base of the sleeve 9 is screwed and fixed. The second bit 5 is the slit 13 of the sleeve 9.
As shown in FIGS. 1 and 2b, the projection 15 provided on the bottom surface of the drill rod 7 and the cylindrical surface 4b, which is a non-threaded relief part on the inner surface of the inner cylinder at the rear end of the first bit 4, allow the top of the drilling rod 7. The hold is fixed. That is, the second
The bit 5 is plate-shaped, and when inserted into the slit 13 of the sleeve 9, its rear end is supported by the slit bottom protrusion 15 provided on the sleeve, and its tip is held down by the cylindrical inner surface of the rear end of the first bit. It is mounted on the drilling rod 7, and a cutting edge tip 5a is provided on the front side of the protruding end of the outer periphery.

Then, when the drilling rod 7 is moved in the pulling direction, the hook plate 11 at the tip of the drilling rod 7 engages with the tip 5b of the second bit 5, as shown in FIG. The second bit 5 is displaced to be drawn into the slit 10. Note that a triangular notch 5c is provided on the lower surface of the second bit 5, and as shown in FIGS. The outer periphery of the sleeve 9 is shaped so that it can be inserted into the slit 13 of the sleeve 9.

In the figure, reference numeral 4a is a cutting edge tip, 16 is a water injection hole, and 7a is a rib guide for the steel pipe 3.

With the structure described above, in the state shown in FIG. 1, when the drilling rod 7 is pressed and rotated by impact, the steel pipe 3 is simultaneously inserted into the drilling hole by the first bit 4 and the second bit 5. Ground drilling work will be carried out.

When the drilling rod 7 is retreated after completing the drilling work, the lower surface of the tip side of the second bit 5 is not supported by the drilling rod, and the hook plate 11 at the tip of the drilling rod is attached to the tip of the second bit 5. It engages with the provided protrusion 5b and acts to displace it inward. At this time, the rear end portion of the second bit is supported on the upper surface of the drilling rod 7, but the outer edge portion of the second bit is completely recessed into the slit 13 of the sleeve 9, as shown in FIGS. 3 and 4. state.

[Effects of the Invention] The drilling device according to the present invention does not have any uncertain parts such as springs, and the second bit in the drilling is reliably restrained in all three axial directions, and is free from stress caused by strong impact, rotational force,
It can withstand the flow of flour, and when it is pulled out, it is forcibly retracted by the hook plate at the tip of the rod, so it is less affected by the flow of flour.
As mentioned above, it is of course effective in realizing the method of drilling a hole and inserting a steel pipe at the same time, but in areas where the ground is prone to collapse, even if the hole is drilled, the hole wall may collapse or powder may accumulate. In many cases, the rod bit would not come out and drilling would become impossible, and drilling into such ground had to be done by boring, which was several tens of times more time-consuming and costly. Therefore, it is possible to provide an epoch-making device that makes it possible to easily drill holes in bad ground using a rock drilling machine.

In addition, it will also become possible to implement the wide-bottom blasting method, which has been desired for a long time and has been devised in various ways, in which the diameter of the bottom of the hole is expanded and a large amount of explosives is filled at the bottom of the hole to efficiently blast the hole.

Furthermore, by enlarging only the bottom of the hole, inserting a steel rod, etc., and fixing it with cement, a highly reliable and strong anchor method (for retaining walls, etc.) becomes possible.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing the configuration of the tip of the drilling device according to the present invention, and FIGS. 2 a, b, and c are sectional views taken along lines AA, BB, and C-C in FIG. 1, respectively. , Fig. 3 is a view similar to Fig. 1, and is a sectional view showing a state in which the tip is reduced so that the drilling bit can pass through the steel pipe, and Fig. 4 is a cross-sectional view taken from B'-B in Fig. 3. FIG. 5 is a cross-sectional view of a schematic configuration of a conventional example of a drilling device. 1...Rock rock machine body, 3...Steel pipe, 4...1st
Bit, 5...2nd bit, 6...Rock, 7...
Drilling rod, 8...Brim part, 9...Sleeve, 1
0...Slit, 11...Hook plate, 12...Groove, 1
3...Slit, 14...External thread, 15...Protrusion.

Claims (1)

[Scope of Claims] 1. A drilling rod having a slit at its tip, a hook plate attached to the tip of the slit, and a flange provided at a distance from the rear end of the slit, which moves forward beyond the flange of the drilling rod. It has a slit that corresponds to the slit, a protrusion is provided on the outer periphery of the rear end of the slit, a sleeve with an external thread is provided on the tip, and a cutting tip is provided on the front surface. , the first bit has an internal thread with a cylindrical surface at the entrance, and is attached by screwing into the external thread of the sleeve.The first bit fits into the slit of the sleeve, and the front end has a surface that touches the cylindrical surface of the first bit, and the tip thereof. A protrusion with a sloped surface is provided, and the rear end is housed inside the protrusion on the rear end surface of the slit of the sleeve, and when the rod is retracted, the inner surface of the rear end is supported on the surface of the rod. A notch is provided so that the rod can be inserted into the slit of the sleeve, and a plate-shaped second bit with a cutting tip is provided on the front of the outwardly protruding portion near the center. When drilling a hole by pressing the rod, the second bit is restrained in a state of protruding toward the outer circumference and drills a hole with a larger diameter than the first bit, and when the rod is pulled out, the second bit is pressed against the hook plate of the rod. Forcibly drawn inward by
A drilling device characterized by being inserted into a slit between a rod and a sleeve and housed within the outer diameter of a first bit.