EP0352215B1 - Drilling tool - Google Patents

Description

The invention relates to a drilling tool according to the preamble of claim 1.

When drilling in rock or concrete, the resulting drilling dust or cuttings must be transported out of the borehole using the spiral shaft.
Fastening regulations for anchoring using dowels stipulate that the drilling dust must be completely removed from the borehole. However, this can pose difficulties since, on the one hand, the drilling dust can be baked in the borehole and, on the other hand, suitable means for removing the drilling dust, such as compressed air or the like, are not always available. Anchoring using a dowel screw connection, however, essentially depends on the removal of drilling dust from the borehole.

The outside diameter of the spiral shank of a conventional rock drill is always below the nominal diameter of the drilling tool, which is formed by the outside diameter of the hard metal cutting edge. As a result, the spiral shaft cannot completely ensure that the drilling dust is properly scraped off the inner wall of the borehole.

From FR-A-22 15 285 a drilling tool has become known which has a slide-on conveying helix which consists of a screw-shaped wire part made of rubber, synthetic rubber, pressed material or is provided with bristles, the outer edge the helix is narrow and flexible, so that a certain brush effect and thus cleaning of the borehole is to be achieved through these areas.

A disadvantage of this known drilling tool is the structure of these brushing elements, which is to be formed by simply reducing the wall thickness of an otherwise conventional conveying spiral or by gluing the brushing elements. In practice, this should lead to rapid wear of these areas in the first-mentioned training, since these are not actual brush-like organs, but rather means which at most exert a certain scraping effect.

From US-A-38 24 646 a rotating and brushing tool for use in a pipe cleaning machine has also become known. A front, rotating plate is used for material removal, similar to a drilling tool within a pipe to be cleaned. In addition, bristle bundles leading radially outwards are arranged on the shaft and have a cleaning effect on the pipe to be cleaned. This tool is not a drilling tool to be used specifically for the use of stone work, in which the transport of drilling dust plays an essential role.

The invention is based on the object of proposing a drilling tool, in particular a rock drill, which ensures problem-free discharge of the drilling dust from the borehole during the manufacturing process and has a high durability or resistance.

This object is achieved on the basis of a drilling tool of the type described in the introduction by the characterizing features of claim 1.

The measures listed in the subclaims allow advantageous and expedient developments of the drilling tool according to the invention.

The invention is based on the knowledge that only one Wholesome brush element made of bristles can bring about a satisfactory and absolutely safe cleaning of a borehole, ie the arrangement according to the prior art is not very suitable for reliable removal of the drilling dust, in particular under difficult conditions. In contrast, the invention provides full-fledged brush elements with a large number of individual bristles, which process every area of the borehole with a large effective brushing surface. This ensures an absolutely safe removal of the drilling dust from the borehole.

The invention further provides that, in addition to the function of cleaning the inner wall of the borehole, the brush elements also serve as a conveyor helix due to a corresponding helical arrangement of these brush elements. Either individual bristle bundles or elongated strip brushes are used as brush elements, as are known per se from other fields of application.

The basic idea according to the invention is realized particularly advantageously on a one-piece drilling tool or on a drilling tool provided with a plug-on helix. The brush elements can either be inserted directly into the existing grooves of a conventional drilling tool or into grooves or recesses in a cylindrical shaft. In the latter case, the brush elements alone form the spiral gear. The same applies if you make this arrangement on a plug-on conveyor spiral.

In a development of the invention it is provided that the brush elements in bores or in grooves glued in or, if necessary, fastened in a form-fitting manner by means of a snap connection. Using a suitable foot or carrier tape, the brush elements can also be soldered in or screwed in with a cylindrical brush foot. As a result, the brush elements can be designed as replaceable elements. The bristle or brush elements can also be fixed by means of material flanging.

In a preferred embodiment of the invention, the bristle bundles are arranged in the groove base of the spiral shaft in such a way that they overlap in the axial direction or that they are also arranged spirally in the groove base. The axial overlap ensures that every inner surface area of the borehole is covered.

An advantageous development according to the invention provides that the strip brushes are arranged on a flexible carrier tape made of plastic or metal, this tape in turn being spirally wound up in grooves. It is advantageous if the carrier tape is completely embedded in a groove so that the brushes cannot be sheared off.

It is also expedient if the strip brushes are arranged asymmetrically in the grooves in such a way that an additional drilling dust space results from the groove.

It is also particularly advantageous that the brushes are welded onto the plastic carrier tape or directly onto a tubular slip-on helix, the individual brushes penetrating approximately 5/10 mm into the base material.

When using strip brushes, it is also advantageous if they are arranged spirally in segment sections, wherein metal webs can preferably be provided as supporting conveyor spiral sections between the segment sections.

In the case of a two-start spiral shaft, in a preferred embodiment of the invention, a conveying helix can be formed in a conventional manner with a metal web or, in the case of an attachable helix, also with a plastic web and the second conveying helix can be formed by brush elements.

The spiral shaft or the conveying helix can be produced from a twisted or twisted base material, the base material having axial longitudinal grooves or axially arranged bores for receiving the brush elements before the twist, which form a spiral after the twist.

In certain cases it may be sufficient if the brush elements are only arranged in the upper third of the spiral shaft, since this can be sufficient for cleaning the borehole. In principle, however, it is possible to equip the spiral shaft with brush elements.

If the brush elements themselves are designed as conveying coils or sections of conveying coils, the task of conveying the drilling dust is carried out by the brush elements themselves and possibly by the additional grooves for the strip brushes. Depending on the application, the individual bristle bundles or the strip-shaped strip brushes are suitable.

Fig. 1

einen herkömmlichen Gesteinsbohrer mit Metallförderwendel und im oberen Bereich in den Bohrmehlnuten angeordneten Borstenbündel,

Fig. 2

eine spiralförmige Anordnung von Borstenbündel auf einen zylindrischen Förderwendelschaft,

Fig. 3

einen Ausschnitt über alternative Möglichkeiten der Befestigungsart von Borstenbündel in Bohrungen,

Fig. 4

eine auf einen zylindrischen Schaft aufsteckbare Aufsteckwendel mit Borstenbündel im oberen Bereich,

Fig. 5

eine alternative Ausführungsform zu Fig. 2 mit Streifenbürsten anstelle von Borstenbündel und

Fig. 6a, b, c

einen Horizontalschnitt durch Fig.2 oder 5 mit verschiedenen Möglichkeiten der Nutenausbildung für die Bürstenelemente.

Advantageous and practical embodiments of the invention are shown in the drawing and explained in more detail in the following description. Show it

Fig. 1

a conventional rock drill with metal feed helix and bristle bundles arranged in the upper area in the drilling dust grooves,

Fig. 2

a spiral arrangement of bristle bundles on a cylindrical conveyor spiral shaft,

Fig. 3

a section of alternative possibilities of the type of attachment of bristle bundles in bores,

Fig. 4

a slip-on helix with a bristle bundle in the upper area, which can be plugged onto a cylindrical shaft,

Fig. 5

an alternative embodiment to FIG. 2 with strip brushes instead of bundles of bristles and

6a, b, c

a horizontal section through Fig.2 or 5 with different ways of forming grooves for the brush elements.

The rock drill 1 shown in FIG. 1 consists of a drill head 2, a clamping shaft 3 and a spiral shaft or a conveying helix 4 located in between. In such a conventional drilling tool, in the embodiment according to FIG serve to clean the borehole of drilling dust. The Individual bundles of bristles are attached in the groove base of the spiral shaft in such a way that they do not or only insignificantly impair the conveying of drilling dust from the helix.

As shown in Fig. 3, the individual bristle bundles are introduced into bores 7 in the groove base 5 of the spiral shaft 4, the upper bristle bundle 6 in Fig. 3 glued into the bore 7 and the lower bristle bundle 6 'by means of a snap connection 8 in the bore 7th is introduced. Instead of the snap connection 8, a threaded connection can also be provided.

The bristle bundle 6 consists of a one-piece, brush-like round or conical bristle element made of a plastic or metal with an optionally molded foot as a fastening element, such as. B. screw head or snap connection 8 or soldering or adhesive sleeve 12. Such elements are shown for example in the brochure of Pedex & Co. GmbH in 6948 Wald-Michelbach.

As shown in FIG. 3, the bristle bundles 6 can be arranged off-center in the drilling dust groove or the groove base 5 of a conventional drilling tool. In particular, the distance a pointing towards the drill head in the groove base is made larger than the remaining distance b, since this area serves to hold the drilling dust.

In the exemplary embodiment according to FIG. 2, the individual bristle bundles 6 are arranged spirally on a smooth cylindrical conveyor helix shaft 9, so that they are arranged in the manner of a separate conveyor helix 10 with the pitch angle α. The outer effective The diameter (d) of the conveying helix 10 formed by the bristle bundles 6 is the same size or slightly larger than the nominal diameter (D) of the drilling tool, the nominal diameter being formed by the hard metal cutting element 11 on the drill head 2. This ensures that the inner wall of the borehole is always reached by the brushes of the individual bristle bundles. This also applies to the exemplary embodiment according to FIG. 1.

In the exemplary embodiment according to FIG. 4, the bristle bundles 6 are introduced into bores in the wall 14 of a hollow helix 15 which is hollow in the inner region. The bristle bundles 6 are in turn arranged spirally to form a conveyor helix 10 with the pitch angle α. This plug-on helix 15 can then be pushed onto a cylindrical drill shaft in a conventional manner.

To insert the strip brush, continuous grooves 18 are made in the wall 14 of the plug-on helix 15 (FIG. 4), as is also shown in the exemplary embodiment according to FIG. 5 for a solid material for a drill spiral shaft 9. The strip brushes thus form a separate conveyor helix 19, similar to the conveyor helix 10 in FIG. 2, formed from the individual bristle bundles 6. This conveyor helix then also has the task of transporting the drilling dust out of the borehole and cleaning the borehole wall of drilling dust.

5, the cylindrical drill shaft is also provided with grooves 18 for receiving the strip brushes 17, possibly with additional gaps 20 'or webs 21'. The outer diameter (d) of the strip brushes 17 is, as in the examples described above, of the same size or slightly larger than the nominal diameter (D) of the drilling tool.

The representations in FIGS. 6a to c show a horizontal section through the spiral shaft according to FIG. 3 or 5 with different types of fastening of the bristle bundles or the strip brushes. It must be ensured here that the individual bristles are firmly clamped to the conveyor helix shaft or are otherwise fastened. 6a to c, undercuts 22 are provided for this purpose, which allow the rear part of the bristles to expand and thus to strengthen the connection. Furthermore, edging 23 or other form-fitting connections can be provided.

If the helical feed shaft is produced by twisting the drill shaft (not shown in detail), the initially axially extending longitudinal grooves for receiving the strip brushes can also be produced with an undercut 22 according to FIG. 6 and the receiving base of the strip brushes can be shaped accordingly.

The strip brush can then be inserted into this guide groove in an axial feed movement before or after the drill shaft is twisted.

If the rock drill is designed as a two-start conveyor helix, the conveyor helix 10 formed from the bristle bundles 6 or the conveyor helix 19 formed from the strip brushes 17 can form one of the two conveyor helices, while the second conveyor helix is retained as a conventional metal web.

, wobei b die Breite der Borsten 25 ist. Hierdurch ist gewährleistet, daß die Flexibilität der Borsten 25 in der Nut 18 stets gewährleistet ist, d. h. durch die Einbettung in der Nut bzw. in der Tasche 18 wird ein Abscheren der Borsten 25 am Bohrlochrand durch Verkantung der Maschine vermieden. Hierzu ist es zweckmäßig, daß die ECk-Kanten 26 der Nuten 18 abgerundet sind.In Fig. 7, the winding process of a strip brush 17 on a slip-on coil 15 is shown again. For this purpose, the strip brush 17 has a carrier tape 24 made of plastic or metal, in which the bristles 25 are anchored. In the exemplary embodiment according to FIG. 7, deep puncture grooves 18 are provided, into which the carrier tape 24 is completely sunk. The depth t of the sinking of the carrier tape 24 into the groove 18 should be approximately two times b $\text{(t ∼ 2 xb)}$

, where b is the width of the bristles 25. This ensures that the flexibility of the bristles 25 in the groove 18 is always guaranteed, that is, by embedding in the groove or in the pocket 18, shearing of the bristles 25 at the edge of the borehole is avoided by tilting the machine. For this purpose, it is expedient that the corner edges 26 of the grooves 18 are rounded.

As shown in the uppermost part of Fig. 8, the bristles 25 can be arranged asymmetrically in the groove 18, ie the upper region x 1 is larger than the lower region x 2, whereby an additional drilling dust space 27 is created above the bristles 25. This arrangement can also be transferred to FIG. 7.

8 shows a strip brush 17 in the upper area corresponding to the description in FIG. 7, but without carrier tape 24. In the lower area, an arrangement of bristle bundles 28 in a groove 18 is shown. These bristle bundles can, however, also be welded onto a carrier tape 24 ', similar to the carrier tape 24 according to FIG. 7, and thus form a strip brush with individual bristle bundles 6 that can be wound up.

It is also possible that both a strip brush 17 and a bristle bundle strip 28 are applied to a conveyor spiral in corresponding grooves 18 or directly on the conveyor spiral shaft without grooves, the arrangement being able to be carried out one after the other in the axial direction or - in the case of a two-start spiral - the one spiral path consists of a strip brush 17 and the other spiral path consists of a strip-shaped bristle bundle 28.

Claims (10)

1. Drilling tool for hammer or impact drilling machines for drilling rock, with a drill head (2), a drill shank (3) and a transport spiral shaft (9, 14) positioned between them having a single or double transport spiral, wherein brushing members (6, 17) for cleaning the drilled hole are provided in helical or spiral form on an integral drilling tool (1) or on an attachment spiral (15) for a drilling tool, the active outside diameter (d) of which extends at least to the nominal diameter (D) of the drill, characterised in that said brushing members (6, 17) are provided in the form of cylindrical or angular bundles of bristles (6) or elongated brush strips (17), said bundles of bristles (6) being inserted in recesses (7) in said transport spiral shaft (5, 9) or said attachment spiral (15) and said brush strips (17) being inserted into grooves (18) in said transport spiral shaft (5, 9) or said attachment spiral.
2. Drilling tool according to Claim 1, characterised in that the brushing members (6, 17) are glued into the recesses (7) or the grooves (18).
3. Drilling tool according to either Claim 1 or 2, characterised in that the individual bundles of bristles (6) are arranged in the groove base (5) of a conventional metal or plastic transport spiral (4) so as to overlap axially in the form of a spiral.
4. Drilling tool according to Claim 1, characterised in that the brushing members are provided in the form of elongated brush strips (17) or as strips (28) of bristle bundles arranged on a flexible, plastic or metal support band (24, 24'), which may be glued or soldered and is inserted into grooves (18) in the transport spiral section.
5. Drilling tool according to Claim 4, characterised in that the support band (24, 24') for the brush strips (17, 28) is embedded in the transport spiral core (14) over its entire radial width (s).
6. Drilling tool according to either Claim 4 or 5, characterised in that the support band (24) with brush strips (17) is arranged asymmetrically in the grooves (18) in such a way that the groove forms an additional upper area (27) for drill dust.
7. Drilling tool according to one of Claims 4 to 6, characterised in that the brush strips (17) are arranged in a spiral in segments (17', 17''), whereby metal webs (21) are preferably provided as transport spiral sections in the gap (20) between the brush strip segments (17', 17'').
8. Drilling tool according to one of Claims 1 to 7, characterised in that, in a double transport spiral (4), a conventional metal or plastic web forms the first transport spiral and the brushing members (6, 17) form the second transport spiral (10, 19).
9. Drilling tool according to one of Claims 1 to 8, characterised in that the transport spiral (4) is made of a twisted base material, which prior to twisting is provided with at least one axial longitudinal groove or with axially arranged holes to accommodate the brushing members (6, 17).
10. Drilling tool according to one of the preceding claims, characterised in that the brushing members (6, 17) are arranged in the upper third of the transport spiral (4) facing the drill head (2).

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