JPS62248792A - Bit for drill for forming slot to base rock, etc. - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a bit for a drilling machine for forming slots in rock, concrete, etc. This slot is in the form of an elongated groove, and is formed by a plurality of holes connected laterally.

[Conventional technology]

When excavating tunnels or shafts in bedrock, it is common to use the blasting method, but this method causes pollution problems such as vibration and noise, so in recent years, depending on the construction site, non-blasting methods have become socially acceptable. It has been requested. One of the non-blasting excavation methods is the so-called O3D method (Okumur).
a 5lot Drilling) is known. In this method, a free surface corresponding to the coring of the blasting method is formed on the face, and a large number of crushing holes are formed between or near this free surface, and a hydrocracker, expansive crushing agent, hydraulic (Basically, the rock is crushed by inserting and filling rust etc. to generate cracks between the fracture hole and the free surface.

In this O3D construction method, a major point is how to form a free surface, which corresponds to the coring in the blasting method. The free surface can be roughly divided into large-diameter circular holes and long, narrow groove-shaped slots. The free surface must be easily deformed and destroyed by the crushing force applied to its vicinity, so from the viewpoint of ease of destruction,
It is clear that slots in the form of elongated grooves are superior to circular holes.

However, while large-diameter circular holes can be easily formed using drilling or boring machines, slots are difficult to form using current machines.

This slot, in the form of an elongated groove, is formed by a series of small holes laterally. In this case, when drilling a subsequent hole next to the preceding hole, even if the guide cell is held parallel to the preceding hole and the subsequent hole is drilled, the subsequent hole will gradually move toward the preceding hole as the drilling progresses. It becomes biased and eventually becomes coaxial with the preceding hole. Therefore, the width of the slot becomes tapered, which is not preferable as a free surface for rock crushing.

[Purpose of the invention]

The object of the present invention is to provide a drilling machine bit which does not have the above-mentioned drawbacks, ie a drilling machine bit which can form a slot in which the hole is not biased.

〔Example〕

First, an example of a drilling machine to which the bit of the present invention is mounted will be briefly explained based on FIG.

The drilling machine shown in FIG.
It is attached to the boom of a mobile trolley, for example a drill jumbo, via the. This drilling machine essentially has a guide shell 2 with a U-shape and an inverted U-shape placed back to back.
It consists of a drifter 3 movable along this guide shell, and a rod 5 equipped with a bit 4 at its tip, which is rotated by impact by this drifter. Note that the frame 1 may be provided with a parallel movement mechanism that moves the guide shell 2 laterally in parallel.

One end of a hydraulic jack 6 is fixed to the guide shell 2, and the other end of the jack is fixed to the frame 1. This hydraulic jack 6 serves to hold the guide shell 2 fixed to the rock 7 before the drilling operation. That is, by extending the hydraulic jack, the guide shell 2 moves forward relative to the frame 1, and its tip 8 pierces the rock 7, so that the guide shell 2 is fixedly held.

The drifter 3 is movable along the guide shell 2 by a slider 9 having a U-shaped cross section.

This movement is effected by a chain 13, shown in dashed lines, guided via sprockets 10, 11, 12 and fixed at both ends to the drifter 3, a sprocket 14 driving this chain, and a hydraulic motor 15. The drifter 3 has a built-in mechanism for striking and rotating the rod 5.

Next, the bit 4 of the present invention, which is attached to the tip of the rod 5, will be explained. The bit according to the first embodiment shown in FIGS. 1 to 3 includes guide rods 17 on both sides of a bit body 16. This guide rod is held in the bit body 16 via a holder 18. In this case, the bit body 16
The holder 18 and the bit body 16 have radial and axial play between them to allow percussive rotation of the bit.

The bit body 16 has a hard blade 19 at the tip, and a screw hole 20 at the rear for connecting the bit body to the rod 5.
is formed.

The holder 18 formed as a half member surrounds the bit body 16 and the small diameter portion of the guide rod 17, and holds the bolt 21.
are fixedly connected to each other by.

The bit according to the second embodiment shown in FIG. 4 is provided with a guide rod 17' only on one side of the bit body 16. The rest is the same as the first embodiment.

Next, a method of forming slots using the bits shown in FIGS. 1 to 3 will be described with reference to FIGS. 6 to 10. First, a plurality of holes 23 are drilled at a constant pitch in the rock 7 using a known bit 22 (see Fig. 6.7).

The diameter of this hole 23 is indicated by d, and the pitch is indicated by p.

Next, replace bit 22 with bit 4 in Figures 1 to 3,
A hole 24 of the same diameter d is bored between the preceding holes 23 (see FIG. 8). At this time, the hole is drilled while being guided by the guide rod 17. Since the guide rod 17 moves along the leading hole 23, the trailing hole 24 is drilled without being biased towards the leading hole 23.

When the subsequent hole 24 is drilled, as shown in Fig. 9, the shape is theoretically that the circles touch each other, but due to the runout of the bit 4 and the extra cutting of the rock, it becomes continuous in the lateral direction as shown in Fig. 10. A slot 25 is formed. The height b of the narrowest part of the slot 25 depends on the type of rock, but empirically it is 2/3.
d or more.

When drilling the pilot hole 23 with the known bit 22 (see FIG. 7), the pitch p is adjusted by the boom of the drill jumbo to which the drilling machine is attached, and the pilot hole 23 is kept parallel. In addition, when the drilling machine is equipped with a parallel movement mechanism for moving the guide shell in parallel, the drilling machine itself makes the holes 23 parallel to each other. in this case,
If two guide shells 2 are provided and the interval between them can be adjusted, drilling can be performed even more quickly and easily.

FIG. 11 shows a method of forming slots using the bits shown in FIG. In this case, the subsequent hole 24 is drilled while being guided by one guide rod 17'. Also in this method, the trailing hole 24 is not biased toward the leading hole 23.

The bit of the present invention can be used not only for excavating tunnels and shafts.
It can also be used for breaking concrete, drilling holes, etc.

〔Effect of the invention〕

As explained above, in the present invention, since the bit body 16 is provided with the guide rods 17 and 17' that are inserted into the adjacent holes 23, the trailing hole is not biased toward the leading hole, and the width is reduced. This has the effect of forming a fixed slot.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway plan view of a bit according to a first embodiment of the present invention, FIG. 2 is a view of the bit in FIG. 1 seen in the direction of the arrow ■, and FIG. - Figure 4 is a plan view of a bit according to the second embodiment of the present invention, Figure 5 is a side view of a drilling machine in which the bit is installed, Figures 6-
FIG. 10 is a diagram showing a method of forming a slot with a bit according to the first embodiment, and FIG. 6 is a front view of a leading hole;
FIG. 7 is a sectional view showing the drilling state of the preceding hole, FIG. 8 is a sectional view showing the drilling state of the succeeding hole, and FIG. 9 is a front view showing the theoretical state of the preceding hole and the following hole after the preceding hole. FIG. 10 is a front view of the formed slot, and FIG. 11 is a diagram showing the state of drilling a subsequent hole with a bit according to the second embodiment. 4 ... Bit 5 ... Rod door ... Rock 16 ... Bit body 17.17' ... Guide rod 23 ... Leading hole 24 ... Following hole

Claims (1)

[Claims] 1. A plurality of holes (2
In a bit for forming a slot (25) consisting of a hole (3, 24) in a rock (7) or the like, the bit body (16) is connected to a guide rod (17, 17') inserted into an adjacent hole (23).
). 2. The bit according to claim 1, wherein the guide rods (17, 17') protrude forward beyond the tip of the bit body (16). 3. The guide rod (17) is placed on both sides of the bit body (16).
The bit according to claim 1 or 2, characterized in that each bit is provided in one book. 4. The bit according to claim 1 or 2, characterized in that the guide rod (17') is provided only on one side of the bit body (16).