WO1996008606A1

WO1996008606A1 - Process for setting roof bolts and adapter used for carrying out this process

Info

Publication number: WO1996008606A1
Application number: PCT/EP1995/003574
Authority: WO
Inventors: Heinz Gruber
Original assignee: Reburg-Patentverwertungsgesellschaft Mbh
Priority date: 1994-09-13
Filing date: 1995-09-12
Publication date: 1996-03-21
Also published as: TW288077B; DE4432472A1; DE4432472C2; AU3565895A; EP0803014A1

Abstract

A process for setting a roof bolt by using a self-drilling anchor is characterised in that the drilling anchor bar is coupled by an adapter to a drilling mechanism. A rinsing medium, for example water or air, or a setting medium, for example a mortar suspension, may be selectively guided through the adapter. The coupling between adapter, drilling mechanism and drilling anchor bar is maintained from the beginning of the drilling phase until the drilling hole is completely filled with setting medium. If required, the mixture of rinsing medium and mortar suspension that flows through the central cavity (5) and coupling section (3) of base body (1) into the drilling anchor bar may be continuously adjusted by means of the pipe connection (11) of the adapter, which is fixed in relation to the base body (1'). The adapter allows the roof bolt setting process to be significantly simplified, since it dispenses with numerous mounting and dismounting processes that are otherwise required in the area of the drilling mechanism at the end of the drilling phase.

Description

DESCRIPTION

Method of setting a rock bolt and adapter part for use in such a method

The invention relates to a method and an adapter part according to the respective preambles of claims 1 and 8.

Rock anchors as such are known to serve to stabilize slopes or the inner walls of cavities, in that several successive ones perpendicular to the plane of the slope or also the walls

Mountain strata to be connected. In the case of a self-drilling anchor, a drill rod, which is provided at one end with a drill bit and the other end of which is coupled with a drill drive, is used in a first phase like a drill rod, with the central one extending in the longitudinal direction a flushing medium, for example water or air, which is discharged in the area of the drill bit and the mountain particles loosened as a result of the drilling process, is guided in the cavity extending the drill rod rod, via the annular space between the drill rod rod and the inner walls of the borehole in the rearward direction, ie in the direction of the Drilled out the mouth of the borehole. In a second step, a hardenable medium, eg a mortar suspension or a synthetic resin is also introduced into the borehole, which after filling the borehole and after hardening produces a firm bond between the surrounding rock layers on the one hand and the drill rod rod on the other hand, so that the drill rod rod used remains in the bore as a lost tool and is subsequently used is braced by anchor plates in the area of the hole opening.

From DE 38 40 158 C2 a method for setting a rock anchor is known, in which a self-drilling anchor is used, a mortar suspension or the like being used as drilling medium during drilling, relatively smaller portions of the rock particles being flushed out and being relatively Coarse parts are washed around by the mortar suspension and incorporated into it during its hardening. This method can be used with particular advantage for use in low-cohesion to non-cohesive mountains, since in these cases it would otherwise be difficult to produce a secure bond between the anchor and the surrounding mountains that is suitable for absorbing sufficient tensile forces.

The usual use of a self-drilling anchor is characterized in that during the drilling phase the drilling drive provided with a flushing head is coupled to the anchor rod and remains in this state until the drilling process has been completed. To insert the hardenable medium, the drilling drive must be released from the anchor rod and then the latter must be coupled with a suitable head part for introducing the hardenable medium. This means that from drilling the hole to filling it with a hardenable medium, numerous assembly and disassembly processes are required. are necessary, which naturally adversely affect the cost balance of setting a rock anchor.

It is the object of the invention to design a method and an adapter part of the genera described at the outset in such a way that the process of setting a rock anchor can be accelerated in terms of time and can be designed at low cost. This object is achieved in a generic method by the features of the characterizing part of claim 1.

It is essential to the invention that the drilling drive is coupled to the armature with the interposition of one of the optional or switchable guidance of a flushing medium or a hardenable medium and that this coupling state is used from the drilling phase to the complete filling of the borehole when a self-drilling armature is used the curable medium is maintained unchanged. This means that all assembly and dismantling processes which otherwise would be necessary at the end of the drilling phase in connection with the introduction of the hardenable medium are eliminated. This results in a significant saving in working time and thus labor costs which are otherwise associated with the setting of a single anchor. An adapter part is therefore used according to the invention, which can be switched, for example, by simply switching from the conveyance of a flushing medium to the conveyance of a hardenable medium, and without changes being made to the coupling state of the adapter part with the drill drive on the one hand and the drill anchor rod on the other hand have to. In the simplest case, activities at the end of the drilling phase are therefore limited to simply switching over the medium delivery. The method according to the invention is in accordance with

Features of claims 2 and 3 can in principle be used in conjunction with the flushing media which are usually used and curable media.

The features of claims 4 and 5 are directed to an advantageous embodiment of the method according to the invention. Corresponding to the cohesive state of the rock found in each case, which can also change in particular in sections - as viewed in the longitudinal direction of the borehole - an adapted nature of this mixing ratio can be expedient. This mixing ratio should preferably be infinitely variable so that an optimal adaptation to the mountain conditions found in each case is possible. Thus, in individual cases, a hardenable medium, namely a mortar suspension, can be used as a flushing agent during the drilling process, so that in the case of extremely low-cohesion rock a large penetration of loosened rock particles and mortar and thus a reliable bond between anchor rod and rock result. In the direction of the borehole axis, rock layers of different cohesion states can follow one another, so that these conditions can be achieved in the simplest way by simply adjusting the mixing ratio during the drilling phase, starting from the conveyance of a hardenable medium to the conveyance of a pure flushing medium , in particular can be taken into account in a manner adapted to the individual case, and without complicated assembly and disassembly processes in the area of the drill drive being necessary for these adjustment processes.

The method according to the invention is in accordance with Features of claim 7 can be used when the drilling drive is guided manually, but especially when the drilling drive has a guide, in particular a drilling carriage, a carriage or a comparable guide system. In the latter case in particular, time and thus cost savings are noticeable.

The object set out at the outset, insofar as it is a matter of developing an adapter part for use in the method according to the invention, is achieved by the features of the characterizing part of claim 8.

The basic body mentioned has a central cavity which is in continuous connection with only one coupling section, namely that which is intended for coupling the anchor rod. The other coupling section is intended for coupling the drilling drive, but has no function with regard to the guidance of a flushing medium. The fact that the anchor rod is held from the drilling phase until it is completely filled via the drill drive, which in turn is carried on a drill carriage, a carriage or a comparable guide system, gives the further advantage of a precise central guidance of the anchor rods, a uniform coverage of the mortar and thus also perfect corrosion protection.

According to the features of claim 9, the housing part of the adapter part is fixed axially on the base body using at least one elastic buffer member. In this way, the mechanical stresses of the housing part caused by the impact operation during the drilling process are strongly damped, so that the service life of the adapter part is increased. The Housing part is here opposite to the rotatable

Base body-fixed component provided with at least one pipe connection, the supply of either mortar suspension or a synthetic resin or also a flushing medium being carried out via the pipe connection.

The coupling sections are preferably designed as internal thread sections in accordance with the features of claim 10. However, other forms of training of the coupling section can also be considered, insofar as these are suitable for conveying media.

The features of claim 11 are aimed at dimensioning the flow paths for the hardenable medium and the flushing medium in such a way that the lowest possible pressure losses result. Since the adapter part is used both for guiding the flushing medium and for guiding the hardenable medium, there is the further advantage that an increase in the flushing medium supply and thus a significant increase in the drilling capacity is possible due to a large cross-sectional dimension.

Designing the adapter part in such a way that two flow control elements for controlling the inflows for the flushing medium and a hardenable medium are assigned to a uniform pipe connection. In principle, however, the said annular space of the adapter part can also be provided with two pipe connections , each feeding either a flushing medium or a curable. Serve medium.

The features of claim 13 have the advantage that the components of the adapter part which are exposed to considerable wear and tear are demon- are animal and interchangeable with new parts. Finally, the ring shoulder also offers considerable mechanical protection for these wearing parts during the drilling operation. The adapter part according to the invention is thus simultaneously designed as a robust and user-friendly component.

The features of claims 14 to 16 are directed to a specific embodiment of the mounting of the housing part on the base body of the adapter part. As is known, this mounting must be such that, on the one hand, there is radial guidance of the base body rotatable relative to the housing part, but that, at the same time, axial relative movements of the base body are possible which result from the percussion drilling operation. These bearing functions are then taken over by two running disks, which, for example, have a fixed but detachable connection to the housing part on the end face. After these components naturally form wear parts, they are releasably connected to the housing part. The running disks must have a high surface hardness and in particular a high resistance to abrasive stress. However, at the same time, they must have a high degree of elasticity in order to be able to dampen impact loads, so that the housing part is arranged to be largely insulated from the effects of a percussion drilling operation. In this way, these components can be formed particularly advantageously from a polyamide. In principle, however, any material, in particular plastic, can be considered which has comparable surface properties, damping properties and elastic properties.

Between the pulleys, which are in sliding contact stand with the outside of the body and the

Annulus of the housing part is at least one sealing ring according to the features of claim 17. An essential effect of the sealing ring is that the running disks are insulated from the hardenable medium, for example a mortar suspension flowing through the adapter part, so that the running disks are in any case not exposed to the abrasive effect of this medium.

Since the housing part has a symmetrical structure according to the features of claim 19, it can be pushed onto the base body with changing axial orientation relative to the ring shoulder 7.

The features of claims 20 to 22 are directed to a further embodiment of the adapter part. This adapter part is mounted on the outside of the base body via soft metal rings, which in turn are arranged in an insulated manner against the abrasive effects of a hardenable medium flowing through the adapter part via special sealing rings. An axial damping effect of the impact stresses transmitted from the percussion drilling operation to the housing part is prevented by the fact that the housing part is axially elastically supported on both sides by sealing rings, movements of the basic body acting in the axial direction due to deformation of these sealing rings be collected elastically, so that the housing part is protected against excessive mechanical stress.

According to the features of claim 23, the running disks, in addition to the radial bearing function, simultaneously fulfill the function of an axially acting damper. fυngskδrpers, which rests on the annular shoulder 7 of the basic body.

Two adapter parts suitable for use in the process according to the invention will be explained in more detail below with reference to drawings. Show it:

Figure 1 shows a first embodiment of an adapter part in axial section.

2 shows a second exemplary embodiment of an adapter part in axial section;

Fig. 3 is an end view of the adapter part of FIG. 2 according to arrow III.

1 in FIG. 1 denotes a tubular base body, the two end regions of which each form coupling sections 2, 3, which are equipped with an internal thread designed in the manner of a round thread. The coupling section 2 is used to couple a drill drive, while the coupling section 3 is used to couple an anchor rod. The coupling section 2 ends axially in the continuous partition 4.

5 designates a central cavity within the base body 1, which is located on the side of the partition 4 facing away from the coupling section 2 and is in continuous connection with the coupling section 3. The cavity 5 also has a number of continuous radial bores 6 uniformly distributed in the circumferential direction, the meaning of which is given below will be explained later.

7 denotes an annular shoulder projecting from the outer circumferential surface of the base body 1, which has a radially extending support surface on its side facing the coupling section 2. The

The meaning of this ring shoulder 7 will also be explained below.

The area of the bores 6 of the basic body 1 is surrounded by a ring-like housing part 8, which in its central area delimits an annular space 9 in the axial and radially outer direction, which surrounds the outside of the basic body 1. This annular space 9 is thus in continuous communication with the cavity 5 via the bore 6 / the bores 6. The annular space 5 is in continuous communication with a pipe connection 11 via a radial bore 10 of the housing part 8.

The base body 1 is mounted rotatably relative to the housing part 8 and for this purpose soft metal rings 12 are arranged on both sides of the bore 6 / the bores 6, which are made of brass, for example, and which are in sliding contact with the outside of the base body 1. The soft metal rings 12 have an approximately square cross section and are inserted in the radially inner recesses of the housing part 8 in such a way that their outer end faces each lie in a common plane with the remaining end face of the housing part. These soft metal rings thus serve to support the base body 1 within the housing part 8.

13 each denote sealing rings which are inserted in the ring grooves of the outer end faces of the housing part 8. sets are. The sealing rings 13 are in the installed state under elastic tension, with a slight gap between the facing end face of a cover ring 14 or the ring shoulder 7 and the facing end faces of the housing part 8, which gap is bridged by the sealing ring 13.

With 15, two further sealing rings or wiper rings located on both sides of the bore 10 are designated, which are inserted into the ring grooves of the housing part 8, on the radial inside thereof. These sealing rings 15 are thus in radially inside contact with the outside of the base body 1. The cover ring 14 is in turn connected to the base body 1 via a locking pin 16 in a rotational connection. For the rest, it is axially supported on its side facing away from the housing part 8 with the interposition of an elastic buffer member 17, here a round cord ring on an intermediate disk 18, which in turn axially on its side facing away from the buffer member 17 axially via a releasable locking disk 19 is set.

The locking washer 19, the intermediate washer 18, the buffer member 17 and the cover ring 14 are connected in a torsionally rigid manner to the base body 1. After the coupling section 2 is connected to the drill drive, a torque, but also axial forces, are transmitted via the latter, but the latter is only strongly damped due to the action of the buffer member 17 and the sealing rings 13 in connection with the slight axial gaps on both sides of the housing part 18 the housing part 8 are transmitted. These axial forces result in slight axial movements of the housing part 8 on the base body 1 and they are mentioned column dimensioned accordingly on both sides of the housing part 8. In order to ensure in the area of the bore 10 that in the transition area to the bore 6 of the base body 1, axial relative movements only take place in the area of the sealing surface, the bore 10 has a slightly conical design in the area of the axially relatively moving surface and is shown in the drawing indicated extensions 20 on.

The pipe connection 11 can optionally be operated with a flushing medium, for example, via a corresponding switching device (not shown in the drawing) when the adapter part is in operation Water or air or with a curable medium, e.g. a mortar suspension or a synthetic resin are applied, these media being transferred via the bores 10, 6, the cavity 5 and the coupling part 3 into an anchor rod of a self-drilling anchor.

As an alternative to the embodiment shown, the housing part 8 can also be provided with two pipe connections 11, for example diametrically opposite one another, each of which is supplied with a flushing medium or with a hardenable medium with the interposition of flow control elements.

In the following, reference is made to the exemplary embodiment shown in FIGS. 2 and 3, in which

Functional elements which correspond to those of the adapter part according to FIG. 1 are also correspondingly numbered, so that a repeated description in this regard can be dispensed with.

1 'denotes a tubular base body which is provided at the end with coupling sections 2, 3 and which is surrounded by an annular housing part 20 in an approximately central region. The housing part 20 in turn encloses an annular space 21 in the axial direction and in the radially outward direction, which is in continuous connection with the central cavity 5 via at least one radial bore 6 of the base body 1 '. This annular space 21 is also in continuous connection with the pipe connection 11 via a radial bore 22, the radial bore 22 extending coaxially with the inner cross section of the pipe connection 11. In principle, several pipe connections 11 can also be provided, which are connected to the annular space 21 via corresponding bores 22. The bore 6 is designed as an elongated hole, the relatively larger cross-sectional axis of which extends parallel to the axis of the housing part 20. Two or more such holes 6 are expediently provided in a uniform circumferential distribution.

The pipe connection 11 is supported on the housing part 20 via a gusset plate 23.

24 each designate two sealing rings, which are axially adjacent to one another and at a slight distance from one another, are inserted in the internal grooves of the housing part 20 and are in sliding contact with the outside 25 of the base body 1 ', a pair of these sealing rings being located on both sides of the annular space 21 . This annular space 21 extends axially on both sides considerably beyond the dimensions of the bore 6. Since the outside 25 of the base body 1 'is a sealing surface, it is ensured in this way that axial relative movements between the base body 1' and the housing part 20, which are caused by a percussion drilling operation, occur exclusively in the area of the sealing means. area.

With 26 are designated pulleys, which have an angular shape in cross-section, cover the respective end faces of the housing part 20 and the inside circumference in a corresponding recess

Protrude housing part 20. The running disks 26 are screwed to the housing part 20 and are preferably made of polyamide or a comparable material, in particular plastic. It is essential in this connection that the material used here has damping properties and at the same time a high wear resistance, in particular in the surface area.

When this adapter is in operation, the base body 1 'is in turn rotatably mounted with respect to the housing part 20, there being a sliding contact between the surfaces of the running disks 26, the sealing rings 24 and the surface sections of the base body 1' facing them. The forces transmitted via the radial support surface 7 'of the ring shoulder 7 during percussion drilling operation are transmitted to the housing part 20 in a strongly damped manner via the running disks 26, so that there is no excessive stress on the latter. The gusset plate 23 provides a particularly reliable fixation of the pipe connection 11, which also takes account of the axial stresses mentioned.

The housing part 20 is symmetrical with respect to a central plane 27 which extends perpendicular to its longitudinal axis.

Using an injection drill anchor known per se, which has an adapter part described above is connected to a drilling drive, the drilling method according to the mountain conditions found in a conventional manner using a customary flushing medium or, in deviation from this, using a mixture, consist of a flushing medium and a hardenable medium or else directly and carried out exclusively using a hardenable medium, the choice of the medium guided over the injection drill anchor during the drilling phase being made dependent on the rock conditions found. The drilling drive is arranged on a guide which is used to support the anchor, starting with the drilling phase, until the borehole is completely filled. The latter brings with it a considerable simplification of otherwise necessary manual activities in connection with the setting of a rock anchor. A drilling mount is used as a guide, which is supported, for example, on a vehicle or in some other way.

The housing part of the adapter is always connected to structural elements of the base body with an intermediate arrangement of elastically deformable intermediate bodies such as sealing rings, thrust washers, buffer bodies or the like, so that axial movements of the base body can be absorbed with elastic deformation of the intermediate bodies mentioned, without one there is excessive mechanical stress on the housing part. The housing part can also be removed in a very simple manner on one side of the base body, so that parts of the adapter part which are susceptible to wear are arranged so that they can be replaced easily.

Claims

PATENT CLAIMS

1. Method for setting a rock anchor, wherein in addition to a drill drive, at least one self-drilling anchor is used,

characterized,

that the drilling drive is coupled to the anchor with the interposition of an adapter part suitable for the optional guidance of a flushing medium or a hardenable medium,

that the anchor is held by the drill drive until the borehole is filled with the hardenable medium mentioned,

- Wherein after completion of the drilling process without decoupling the drilling drive said medium is introduced into the borehole via the adapter part.

2. The method according to claim 1, characterized in that

- That water or air is used as the flushing medium and

- That a mortar suspension is used as the hardenable medium.

3. The method according to claim 1, characterized in

- That water or air is used as the flushing medium and

- That a synthetic resin is used as the hardenable medium.

4. The method according to claim 1 or 2, characterized gekenn¬,

- That at least the drilling process is carried out in accordance with an adjustable mixing ratio between the rinsing medium and the hardenable medium.

5. The method according to any one of the preceding claims 1, 2 or 4, characterized in

- That the drilling process is carried out in sections with a flushing medium, a hardenable medium or a mixture of these media in accordance with the state of cohesion of the mountains found.

6. The method according to any one of the preceding claims 1 to 5, characterized in that

- That an introduction of a curable medium takes place while rotating the armature.

7. The method according to any one of the preceding claims 1 to 6, characterized in that - That the drill drive and the anchor are held by a guide until the borehole is filled.

8. adapter part for use in a method according to any one of claims 1 to 7, characterized by

a tubular base body (1, 1 '), which is provided at the end with coupling sections (2, 3) for coupling an anchor rod or a drill drive,

- The basic body (1, 1 ') has a central cavity (5) which is in continuous connection on the one hand with the coupling section (3) serving to couple an anchor rod and on the other hand via radial bores (6) with an annular space (9 , 21), which is provided with at least one pipe connection (11),

- The annular space (9, 21) is delimited on the inside by the base body (1, 1 ') and otherwise by a housing part (8, 20) carrying the pipe connection (11).

9. Adapter part according to claim 8, characterized in

- that the housing part (8, 20) containing the annular space (9, 21) is designed as a cylindrical component provided with the pipe connection (11),

- That the base body (1, 1 ') is rotatably arranged with respect to the housing part (8, 20) and

- That the housing part (8,20) with the interposition of at least one elastic buffer member on the Base body (1,1 ') is fixed axially.

10. Adapter part according to claim 8 or 9, characterized in

- That the coupling sections (2, 3) are designed as plug-on sections provided with internal threads, which are designed and dimensioned for coupling the drill drive or the anchor rod.

11. Adapter part according to claim 10, characterized in

- That the internal cross-sections of the pipe connection (11), the radial bore (6) of the base body (1,1 ') and (10,22) of the housing part (8,20) are dimensioned the same with each other,

- That in the area of the relatively movable surfaces of the base body (1, 1 ') on the one hand and the housing part (8, 20) on the other hand, at least one labyrinth seal is arranged and

- That the inner cross section of the coupling section (3) for the anchor rod is dimensioned such that, starting from the cavity (5), there is a continuous cross-sectional profile for the flow of the flushing medium or the hardenable medium.

12. Adapter part according to one of claims 8 to 11, ge indicates by separate pipe connections for supplying a curable medium and a flushing medium, which are in continuous connection with the cavity (5).

13. Adapter part according to one of the preceding claims 8 to 12, characterized in that

- That the base body (1, 1 ') is axially fixed on one side with the interposition of at least one elastic buffer member on an annular shoulder (7) of the base body (1, 1').

14. Adapter part according to one of the preceding claims 8 to 13,

characterized,

- That two bearing disks (26) are provided for supporting the housing part (20) on the base body (1 '),

- That the running disks (26) are axially on both sides of the annular space (21) with the outside (25) of the base body (1 ') in contact and

- That the running disks (26) with the housing part (20) are in firm connection.

15. adapter part according to claim 14,

characterized in that - the running disks (26) are screwed to the housing part (20).

16. Adapter part according to claim 14 or 15,

characterized,

- That the discs (26) made of polyamide or Material, in particular plastic with comparable elastic and surface properties.

17. Adapter part according to one of the preceding claims 14 to 16,

characterized,

- That between the running disc (26) and the ring groove (21) - inserted in the grooves of the housing part (20) - at least one sealing ring (24) is arranged, which is in contact with the outside (25) of the base body (1 ') .

18. Adapter part according to one of the preceding claims 14 to 17,

characterized,

- That the annular space (21) forms a flow cross-section extension for a flowable medium between the bores (6, 22).

19. Adapter part according to one of the preceding claims 14 to 18,

characterized,

- That the housing part (20) has a symmetrical structure with respect to a central plane (27).

20. adapter part according to one of claims 8 to 13,

characterized, - That two soft metal rings (12) are provided for supporting the housing part (8) on the base body (1), and

- That the soft metal rings (12) on both sides of the annular space (9) with the outside of the base body (1) are in contact.

21. Adapter part according to claim 20,

characterized,

- That between the soft metal rings (12) and the annular space (9) - inserted in the grooves of the housing part (8) - at least one sealing ring (15) is arranged, which is in contact with the outer surface of the base body (1) .

22. Adapter part according to claim 20 or 21,

characterized,

- That the housing part (8) is supported axially on both sides via sealing rings (13) on the annular shoulder (7) and a component connected to the base body (1) in a rotationally locking manner.

23. adapter part according to one of claims 14 to 19,

characterized,

- That the housing part (23) is axially supported via a running disk (26) on the annular shoulder (7) of the base body (1 ').