KR20070003850A - Single pass drilling apparatus, use a one-piece drill bit, method and rock bolt for single pass rock bolting - Google Patents

Abstract

The present invention relates to a single pass drilling apparatus, a rock bolt, use of a drill bit and a method for single pass rock bolting for reinforcement and stabilization of excavations. The single pass drilling apparatus comprises an elongated drill steel (11) having a leading (12) and a trailing end (13) with reference to a drilling direction (F). The leading end (12) has a connection portion. A one-piece drill bit (16) is utilized having rock machining means (17,18;17'18'). The drill bit is connectable to the drill steel. The single pass drilling apparatus (10) further comprises a rock bolt (21;121,221;321) adapted to at least partially enclose the drill steel (11). The greatest diametrical dimension (DB) of the drill bit (16) is smaller than the smallest diametrical dimension (DI) of the rock bolt. ® KIPO & WIPO 2007

Description

SINGLE PASS DRILLING APPARATUS, USE A ONE-PIECE DRILL BIT, METHOD AND ROCK BOLT FOR SINGLE PASS ROCK BOLTING}

The present invention relates to the use of single pass drill devices, rock bolts, drill bits and single pass rock bolting methods according to the preamble of the independent claim in the areas of reinforcement, stabilization of excavation, rod bank drilling, bench drilling, pipe installation or case drilling. will be.

Installation of rock bolts to reinforce the excavation is generally carried out in two separate steps. Usually, the drill steel and the drill bit are extracted before the hole is drilled and the bolt is inserted into the hole and tightened or finished with a grout. Single pass lock bolting eliminates the removal of the drill steel for inserting the bolt to be removed so that these two steps are performed simultaneously. The advantages of single pass bolting minimize the time required for bolt installation, improve the safety of drilling machine operators when compared to manual or semi-manual bolting, and brighten the prospect for full automation of the process. An additional advantage is the improved quality and accuracy of rock bolt installation compared to manual or semi-manual bolting. The diameter of the hole is important for rock bolt performance, for example in terms of friction such as split-sets, bolts. An additional advantage of single pass bolting is that the hole cannot collapse when retrieving the drill bit because the bolt is already in the hole. These points will lead to a much better effect as the bolt is always installed, i.e. there will not be a hole to collapse.

Prior attempts at single pass bolting have focused on innovative rock bolts, which also serve as drill steel, with drill bits provided near the ends. Such devices are used in rotary drilling methods or rotary / hit drilling methods and are generally not suitable for solid ground conditions. Existing rigid ground blow rock bolts that do not reuse drill bits are costly. There are a wide variety of roof bolts, one particular type of which is tubular (eg, split set, Swellex, etc.) with a central bore formed through the entire length of the bolt. Drill bits suitable for extraction through the casing were complex and expensive. The cost competitiveness of the bit cost over the drilling speed of conventional single pass rockbolts has been difficult to understand due to the use of specialized rockbolts and the exclusive use of complex and recoverable bits. Nevertheless, the advantages of the installation of self drilling loop bolts overwhelm the non-self drilling type.

One object of the use and method of the drilling device, rock bolt, drill bit of the present invention is to substantially overcome, or at least provide an alternative to, the aforementioned problems associated with the prior art.

It is a further object of the present invention to provide a single pass drilling device for a loop bolt.

Another object of the present invention is to provide a tubular expandable magnetic drilling loop bolt.

It is a further object of the present invention to provide a single pass drilling device for a loop bolt that can be used more attractively in the mining industry because it is less expensive to use than the above mentioned kind of loop bolt.

It is a further object of the present invention to provide a single pass drilling apparatus optimized for loop bolts which allows for simpler and smaller mountings compared to today's mechanized systems.

It is a further object of the present invention to propose the use of a drill bit for use in a single pass drilling device for a loop bolt which is reusable.

Throughout the specification, unless otherwise required by context, the word "comprise" means that the word or variations thereof ("comprises" or "comprising") includes the stated entity or group of units; , Does not mean excluding any other monolith or group of monoliths.

The accompanying drawings show the foregoing embodiments of the invention. The specification of the drawings and related descriptions do not replace the generality of the broad description set forth below.

1A-1G schematically illustrate the procedure of single pass loop bolting using the device according to the invention.

FIG. 1H shows a cross section of the drilling device in a hole similar to FIG. 1D.

FIG. 1K shows a cross section of the drilling device in a hole similar to FIG. 1E.

1l shows an exploded view of a drilling device according to the invention.

2a and 2b show a side view of a drilling device according to FIG. 1c and an end view of a drill bit according to the invention.

3A and 3B show an alternative embodiment of a drilling apparatus for single pass bolting in a similar manner to FIGS. 1H and 1K.

4a and 4b show an alternative embodiment of a drilling apparatus for single pass bolting according to the invention in a manner similar to FIGS. 1h and 1k.

5a and 5b show an alternative embodiment of a drilling apparatus for single pass bolting according to the invention in a similar manner to FIGS. 1h and 1k.

1a to 1g show a single pass drilling apparatus 10 according to the invention. The single pass drilling apparatus 10 includes several parts. The elongated drill steel 11 has a front end 12 and a rear end 13 on the basis of the drilling direction F. The front end 12 comprises a connection including a screw 15, a taper or bayonet connection (not shown). The integral drill bit 16 has machining means 17, 18. The drill bit 16 may be connected to the drill steel via a connection including a screw 20, tapered or bayonet connection (not shown). The single pass drilling device 20 also comprises a lock bolt 21 at least partially surrounding the drill steel 11. The maximum diameter dimension of the drill bit is smaller than the minimum diameter of the rock bolts.

The basic idea of the single pass drilling apparatus 10 according to the present invention is to recover the bit without problems after drilling using bolts surrounding the drill steel. There is no loss of bit part.

The drill bit 16 can be constructed as in the reference figure FIGS. 1K or 2A and 2B. The integral drill bit 16 has two integral parts, i.e., where the shaft CL1 of the pilot portion 14 coincides with the shaft CL2 of the hole 22, so as to adequately guide the entire apparatus 10. There is an elongate pilot section 14 and a reamer section 19. The center axis or center line CL1 of the pilot portion 14 substantially coincides with the center axis of the rockbolt during drilling, but not during withdrawal of the drill bit. The center axis of the reamer portion 19 or the axis of the center line CL2 and the drill steel 11 coincide, but are substantially spaced apart from the axis CL3 of the hole 22. Since the cross section of the pilot part and the reamer part does not necessarily need to be circular, it should be understood that the axes CL1 and CL2 represent the average center line of each part.

The integral lock drill bit 16 comprises a body 25 and a cemented carbide means, ie a chisel and / or buttons 17, 18 and 17 ′, 18 ′. The body of the drill bit is made of steel. The body 25 comprises a substantially conical pilot portion 14 and a substantially conical reamer portion 19. The pilot portion 14 can have a circular cross section as can be seen in FIG. 2B. The pilot section has a front section carrying a chisel 17 extending radially or two front facing buttons 17 'facing in the radial direction. The reamer 19 may have a circular cross section as can be seen in FIG. 2B. The reamer section has a front section supporting three front buttons 18 or four front buttons 18 '. The front face may be convex or substantially planar. The buttons 18, 18 ′ may form a peripheral arch on the reamer. The buttons 18, 18 ′ may penetrate the outer periphery of the reamer part to some extent to machine a hole of a somewhat larger diameter than the steel body during drilling. A chipway or recess may be provided in the area between adjacent reamer buttons through which a flush medium can pass. The lock drill bit is connected to the drill steel 11 by a connection (not shown), or to a driver sub of a down-the-hole hammer (not shown), so that the rotary motion Is delivered in the usual way. The drill steel 11 comprises a channel for carrying a flush medium. The main channel for the flush medium is provided inside the drill bit. This main channel communicates with a number of branch channels exiting from the front end to the front. The flush medium can actually be water, cement or air. The pilot portion makes a pilot hole 22A of smaller diameter and length compared to the hole 22. Important dimensions are as follows.

RP is the maximum radius of the pilot portion 14 compared to the axis CL3 of the hole. RR is the maximum radius of the reamer portion 19. 1/2 (RP + RR) is the radius of the reamer portion 19 compared with the axis CL2 of the drill steel 11. DH is the diameter of the hole 22 equal to the 2 × RR value. The thickness of the tube 21 is shown by E. OFF is an offset of the axis CL3 of the hole 22 and the axis CL2 of the drill steel 11. DD is the diameter of the drill steel 11. DI is the minimum diameter through which the drill bit 16 can move freely. DB is the maximum diameter dimension of the drill bit 16. OD is the outer diameter of the rock bolt. The following equation can be applied.

RR = 1 / 2DH,

RP <OD-RR-2E (applicable to rock bolts 21, 121) or

2RR-E ≦ DI ≦ 2RR-2E (applicable to rockbolt 221 to retrieve drill bit 16 through rockbolt),

DD <RR + RP-2E (so that the drill steel 11 deflects in the bolt 21),

DB = RP + RR.

Example: The following dimensions may be suitable for bolting use. RR = 19 mm, RP = 14 mm, OFF = 2.5 mm and 10 mm <L <60 mm.

The operation of the single pass lock bolting device 10 is shown in FIGS. 1A-1G. The drill bit 16 is connected, for example screwed, to the drill steel 11. Drilling machines, for example standard drill jumbo, hold the drill steel. Preferably, the bolt 21 is fed automatically around the drill steel and is located behind the drill bit 16 in the drilling direction F. In FIG. 1A, the pilot portion 14 will be in contact with the rock first for a short period of time to machine the rock surface during circular interpolation. Next, the pilot portion 14 will find the exact center and start drilling around, and at the same time the drill steel 11 will start to swing around the axis CL1 of the pilot portion (see FIG. 1B). Next, the reamer portion 19 will contact the rock surface and begin to expand the hole made by the pilot portion 14. After a while, the bolt 21 reaches the hole and is inserted into the hole as shown in Figs. 1C and 1H. Usually, the bolts 21 are axially spaced apart from the drill bit 16. The split bolt 21 can support the diameter of the hole 22 through compression. The drill bit 16 will continue to excavate and expand the hole 22, wherein the bolt is advanced by the coupling sleeve 26 of the drilling device (see FIG. 1D) until the supply of the other part is stopped. something to do. The depth of the hole 22 is substantially determined by the length of the bolt 21, which means that the washer 23 located at the rear end of the bolt reaches the rock surface or the entrance of the hole and stops further feeding. (See FIG. 1E). The drilling device has a rock bolt pusher. The bolt pusher is a dolly tool 27 driven by a coupling sleeve 26 or drill steel (see FIG. 1L). The dolly tool 27 usually rotates with the drill steel and the bolt upon insertion. However, during the insertion, i.e. in the case of mechanical anchor bolts, the bolt can remain unrotated, for example, in order to avoid undesired expansion of the shell during drilling. The dolly tool can torque the expansion shell rock bolt when fully inserted. The dolly tool may also slide along the drill steel for easy installation of mechanical shell bolts and grouted bolts. Figure 1e shows a fully inserted rock bolt, with the drill steel and drill bits fully inserted and the pusher pushing the plate to the rock surface. The washer is a loose conventional plate with a central hole that interacts with a bulge 24 at the rear end of the bolt. Next, the drill bit is recovered from the pilot hole 22A (see FIGS. 1F and 1K). It is preferable that the axial spacing between the bolt and the drill bit is greater than the depth of the pilot hole 22A so that the front end of the bolt does not interfere with the number of drill bits. The drill bit and drill steel can be fully recovered and reused for repeated drilling operations. In other words, the single pass lock bolting method consists of the following steps.

Providing a single pass drilling device 10, the drilling device 10 being elongated with a front end 12 and a rear end 13 with a connection 15 in relation to the drilling direction F; Configured to include a drill steel 11 and a rock drill means 17, 18 or 17 ′, 18 ′ and an integral drill bit 16 connectable to the drill steel 11,

Enclosing the drill steel 11 at least partially with a rock bolt 21, wherein the drill bit 16 and the rock bolt 21 are provided with a lock bolt 16 at the time of withdrawal of the drill bit. 21) configured to pass through,

Drilling the hole in the rock while pushing the rock bolt into the hole (22),

Withdrawing the drill steel (11) and the drill bit (16) through a rock bolt (21).

The machine driving the drilling device 10 may be a tower hammer drilling machine, a rotary machine or a down-the-hole facility. In order to prevent abrasion or reduction in the hole diameter due to radial force from the pilot's reamer, i.e. deflection, an angle formed in the radially opposite side of the reamer to the pilot top is given to the radial Try to oppose the force. The force opposite the reamer will help the reamer to keep working in the radially outermost part and also cause the opposite side of the reamer to be worn away rather than too much on the opposite side away from the reamer. Wear pads may be provided on opposite sides of the pilot portion away from the reamer portion. Such wear of the pilot portion on the reamer side may also be advantageous to maintain the hole diameter and partially compensate for the peripheral wear of the reamer portion. This shape will provide a self-polishing drill bit.

3A and 3B show an alternative embodiment of a drilling device for single pass bolting in a shape similar to that of FIGS. 1H and 1K. This embodiment differs from the previously disclosed embodiment in that the bolt 121 has a different configuration. The lock bolt 121 is made from a steel pipe without a longitudinal slot. The rock bolt 121 has a diameter smaller than the drilled hole. As described above, when the hole is drilled, the drill bit and the drill steel are recovered with the bolt 121 remaining in the hole (see FIG. 3B). The maximum diameter dimension of the drill bit 16 is smaller than the minimum diameter dimension DI of the lock bolt 121. Because of the loose parachute or the integral parachute of the rock bolt itself, the bolt remains in the hole with the help of an external system connected to the drilling device.

Next, the grout or resin is filled in or out of the bolt, which can be cured or set by filling. The washer is preferably used to cover the inlet of the hole as described above.

4A and 4B show an alternative embodiment of a drilling device for single pass bolting in a shape similar to that of FIGS. 1H and 1K. This embodiment differs from the previously disclosed embodiment in that the bolt 121 has a different configuration. The rockbolt 221 is made from a steel pipe that has been modified to have a deep depression that substantially reduces its diameter, with dimensions substantially reduced to one half of the cylindrical pipe. The fluid expandable tube forming the rock bolt 221 has an internal elongated pressure fluid supply chamber with both ends closed but with a fluid inlet. The sleeve is pressed against the outer end of the chamber sealed with welding or mechanical closure means. The bolt is of a general U-shape for the drill bit 16 to pass through. In the radial section of FIG. 4B, the ends 221A, 221B are located substantially radially opposite each other, with the bolts being substantially semicircular. The lock bolt 221 is suitable to at least partially surround the drill steel 11. The maximum diameter dimension DB of the drill bit 16 is smaller than the minimum spacing or minimum diameter dimension between the rock bolt and the hole 22.

Drilling operations are performed as described above. As described above, when the lock bolt is automatically inserted into the borehole and the drill bit 16 and the drill steel are recovered, the high pressure liquid is moved through the passage and into the hole leading through the sleeve into the inner chamber of the tube. The tube is plastically deformed and expanded, thereby anchoring the rock bolt inside the bore hole. Next, the rock bolt is fixed by decreasing the pressure. The main function of pressurizing the fluid chamber is described in more detail in US-A-4,423,986. The washer is preferably used to cover the inlet of the hole as described above.

5A and 5B show an alternative embodiment of a drilling device for single pass bolting in a shape similar to that of FIGS. 1H and 1K. This embodiment differs from the previously disclosed embodiment in that the bolt 221 has a different configuration. The lock cable bolt 321 is made from a multistrand steel cable. The drill bit 16 drills and reams in one drilling operation. When the hole is drilled as described above, the drill bit and the drill steel are recovered with the bolt 321 remaining in the hole (see FIG. 3B). The maximum dimension DI associated with the cable bolt 321 is the useful spacing between the cable and the radially opposite hole wall when pressed into the hole.

Thereafter, the grout or resin is filled inside or outside of the bolt and cured or fixed by filling. Cable bolting is an established technique and is widely used for the reinforcement of rock mass near the excavation of a surface or underground rock. The cable bolt is a long, fully grouted, untensioned reinforcement element. The purpose of cable bolting is to improve the shear and tensile strength of the rock mass.

The single pass drilling apparatus according to various embodiments of the present invention comprises a rock bolt suitable for at least partially enveloping the drill steel during drilling, the maximum diameter dimension of the drill bit being smaller than the minimum diameter dimension of the rock bolt.

The advantages of using a self drilling bolt are as follows.

-Drilling and setting are carried out simultaneously.

-Fast and easy installation reduces bolting costs.

-Excellent for difficult geographic conditions (especially unstable drilling holes).

-Strengthening rock during grouting.

-Selection of bolts according to terrain conditions.

-Drilling and setting with standard drill jumbo.

-No special equipment is required.

Drill bits can be used to drill several holes.

The drill bit does not need to key into position before retrieval begins.

Since the invention described herein has many modifications, adaptations, and / or additional features than those specifically described, it is understood that the present invention includes all such modifications, adaptations, and / or additions included in the technical spirit of the claims. shall. Not limited to rotary impact tower hammers. The concept is valid for pure rotary drilling, as well as for DTH rock drills. The number of cemented carbide buttons in the pilot and reamer sections may vary depending on how large the diameter of the drill bit is. The reamer may be provided with a rigid sleeve or insert on a surface substantially the same as the jacket surface to maintain the reamer diameter and improve the quality of the hole walls. It is also to be understood that when deeper holes are drilled, the drill steel and rock bolts can be stretched into more than one component.

Claims (9)

An elongated drill steel 11 having a front end 12 and a rear end 13 having a connection with respect to the drilling direction F, and In a single pass drilling apparatus having rock machining means (17, 18; 17 ', 18') and comprising a drill bit (16) securely connected to the drill steel, The single pass drilling apparatus 10 further comprises rock bolts 21; 121, 221; 321 suitable for at least partially enclosing the drill steel 11, wherein the drill bit 16 and the rock bolt ( 21; 121, 221; 321, characterized in that the drill bit is configured to pass through the rock bolt (21; 121, 221; 321) while the drill bit is withdrawn. 2. The maximum diameter dimension (DB) of the drill bit (16) is smaller than the minimum diameter dimension (DI) of the rock bolt, and the integral drill bit (16) has a spaced center line (CL1) and a center line (CL2). And a pilot portion (14) and a reamer portion (19) each having: A single pass drilling apparatus according to claim 2, wherein the center line (CL1) of the pilot portion (14) substantially coincides with the central axis of the rockbolt during drilling. The single pass drilling apparatus according to claim 2, wherein the center line (CL2) of the reamer portion (19) substantially coincides with the axis of rotation of the front end portion (12) of the drill steel (11). Use of the integral drill bit 16 comprising a pilot portion 14 and a reamer portion 19, each having a spaced center line CL1 and a center line CL2, for use in a single pass drilling apparatus according to claim 1. . In the single pass lock bolting method, With an elongated drill steel 11 having a front end 12 and a rear end 13 with a connection in the drilling direction F, and rock machining means 17, 18; 17 ', 18'. Providing a single pass drilling device (10) comprising a drill bit (16) securely connected to the drill steel, At least partially enclosing the drill steel with rock bolts 21; 121, 221; 321, wherein the drill bit 16 and the lock bolts 21; 121, 221; 321 are at the time of withdrawal of the drill bit; The drill bit 16 is configured to pass through the rock bolts 21; 121, 221; 321, Drilling the hole in the rock while pushing the rock bolt into the hole, and -Recovering the drill steel and the drill bit through a lock bolt. 7. The method of claim 6, wherein the method further comprises providing the drill bit 16 as an integral drill bit comprising a pilot portion 14 and a reamer portion 19 having spaced center lines (CL1 and CL2, respectively). Single pass lock bolting method, characterized in that. A rock bolt for a single pass drilling apparatus according to claim 1, wherein the rock bolt 221 has a partially tubular body having a front end and a rear end, the rear end having a washer and a washer stop means, the rock bolt 221 is a rock bolt for a fluid expandable single pass drilling apparatus, Rock bolt (221) is substantially semi-circular, rock bolt for single pass drilling device, characterized in that the general U-shape to allow the drill bit connected to the drill steel to pass through. 9. The rock bolt of claim 8, wherein the ends (221A, 221B) of the radial cross section of the rock bolt are located substantially radially opposite each other.

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