EP1415065B1 - Drill crown - Google Patents

Description

The present invention relates to a drill bit for drilling, in particular rotary impact drilling, of a hole, in particular a sting hole of a blast furnace, wherein the Drilling bit from a drill head with a plurality of Eartmaterial- or carbide inserts and a base body for Connection with a drive element etc. for driving or applying the drill bit, wherein the hard material or carbide inserts in holes or openings of the drill head, wherein the hard material or carbide inserts in holes or openings of the drill head are received, wherein at least a Hartmaterial- or carbide insert on the in the drill head received end at least partially with a curved or curved surface contour is formed, which with a complementary, curved or curved Surface of the drill head and / or the body cooperates.

In connection with drill bits it is known to increase the drilling power in a head a plurality of Hartmaterial- or cemented carbide inserts, such a For example, using sleeve-shaped Inserts can be made, like this For example, from EP-B 0 581 534, US-A 4,951,672, EP-A 0 573 135, EP-A 0 943 708 or EP-A 0 353 214 can be seen. In addition, it is known such Hartmaterial- or hard metal inserts, for example with the base material of a drill head to solder to a To avoid falling out of the hard material inserts, such as this example, the DF-A 34 08 225 can be seen. Known hard material or carbide inserts in connection with the production of a drill bit usually have at the projecting from the drill head cutting part a substantially normal to the longitudinal axis of the insert Level up, whichever is possible for a power transmission on a correspondingly flat surface of the Base material rests, while in DE-A 34 08 225 a recess provided below the end of the inserts is, so that no immediate attachment between the insert and the bore is provided. Under consideration of rough. Operating conditions and in particular at a Drehschlagbohren applied forces and by a usually not completely uniform load of Drill bit and in particular the hard material or hard metal inserts, which to sweep over a corresponding Drilling surface partially at an angle to the longitudinal axis of Are arranged drill bit, takes place off-center or uneven loading of the hard material inserts, so that a proper power transmission from the drill head or the base material on the Hartmaterial- or carbide inserts especially as the service life progresses due to wear. Not easily guaranteed is.

An embodiment of the type mentioned is, for example to see US-A 5 558 170, wherein with a special Tool receiving openings for the hard material or hard metal inserts must be formed in the drill head.

The present invention now aims at providing or arranging hard material or hard metal inserts a drill bit of a drill bit ensure that itself at uneven stress or wear of such Hartmaterial- or hard metal inserts a corresponding large area or a large and substantially constant Surface area for the 'transfer of the Impact energy to achieve a 'correspondingly fast Drilling progress is provided and even if necessary loosened insert avoided falling out becomes.

To solve these problems is the drill bit according to the invention starting from a drill bit of the aforementioned Art essentially characterized in that the with the curved or curved surface contour formed End of hard material or Carbide insert one opposite the end of the hard material projecting from the drill head or carbide insert enlarged external dimensions having. This can be done even with a slightly relaxed Hard material or carbide insert falling out the same avoided from the drill head or the main body become. By such inventively proposed, Enlarged external dimensions can be the Hartmaterialeinsatz safely in a corresponding receiving opening store in the drill bit and it can further be a corresponding large surface for safe transmission of the Provide impact energy.

Since at least one Hartmaterial- or carbide insert the end received in the drill head with at least partially a curved or curved surface contour formed. which is with a complementary, curved or curved surface of the drill head and / or the base body It will ensure that, even in the case of uneven Strain or wear of such Hard material or .. carbide insert and one if necessary resulting loosening of the same in the receiving opening Nevertheless, the complete reliable in the drill head Dissolving energy or in particular impact energy of the Basic body of the drill bit over the respective hard material insert or all hard material inserts in the treated Material can be introduced or transferred. By providing appropriately curved or arched Surface contours both at the end received in the drill head the respective Hartmaterialeinsatzes as well as the cooperating surface of the drill head and the base body This results in a large and. substantially constant area for transfer to the base body the drill bit through a drill pipe and on it acting impact element applied impact energy.

According to a particularly preferred embodiment, it is proposed that the curved surface contour of the end of hard material or cemented carbide insert from a spherical one Surface or a spherical layer is formed, whereby by such a spherical surface or Ball layer a cost-effective and simple production with the greatest possible adaptation of the positioning of an optionally loosened hard material insert in the drill head or the corresponding receiving opening can be achieved.

For a proper and simple definition of a hard material or carbide insert is in accordance with a weiters preferred embodiment proposed that the light Width of a hole or .. opening for receiving the Hard material or carbide insert the outer dimensions of the end of the hard material to be received in the drill head or Carbide insert at least slightly exceeds and that the Hartmaterial- or carbide insert in the in the Bore received portion surrounded by a sleeve is, the outer dimensions of the clear width of the bore adapted to the drill head, wherein, as stated in the introduction, the use of appropriate pods laying down Hard material or carbide inserts for themselves seen is known.

For a secure fixing of such hard material or cemented carbide insert using a sleeve according to a further preferred embodiment, that surrounding the Hartmaterial- or carbide insert Sleeve weldable with the material of the drill head is. While in known embodiments hard material or carbide inserts usually directly with the material were soldered to the drill head or the base body, can be welded by the use of a sleeve between the sleeve material and the material of the Make body or the drill head, while usually a welding of the Hartmaterial- or Carbide inserts used materials not possible is. By providing a weld for fixing a hard material or cemented carbide insert on the drill head or the body is further ensured that when using a drill bit according to the invention under increased Temperatures, for example for the production of a Sting hole of a blast furnace, despite the prevailing, if necessary, high temperatures the welded joint to Determination of Hartmaterial- or carbide insert the drill bit is not loosened or loosened.

Alternatively to the provision of insert sleeves, which a Determination of hard material or carbide inserts in allow correspondingly larger openings having openings is according to a further preferred embodiment proposed that the Hartmaterial- or carbide inserts from the body of the drill bit turned Side of the drill head in the holes or passage openings are fit and that the drill head after recording the Hartmaterial- or hard metal inserts with the body connectable, in particular weldable, is. After one Fitting the hard material or carbide inserts in the Boring head, wherein the hard material inserts, for example against falling out by providing accordingly larger outer dimensions having partial areas are secured, can be subsequently the drill head connect directly to the main body of the drill bit, in particular, so that in turn a reliable Definition of hard material or carbide inserts is achievable.

As a substantially hood or cap-shaped drill head, which surrounds the body of the drill bit, if necessary requires an increased manufacturing effort is according to a further preferred embodiment, that the drill head in particular at positions or lines for receiving in each case a plurality of hard material or carbide inserts is formed divided and that the subregions of the drill head after receiving the hard material or carbide inserts in the holes or openings connectable to each other and / or to the base body, in particular welded, are. Such subareas or sections of the drill head can be also correspondingly simple and exactly matched to each other which, in turn, the individual elements of the drill head after a recording of hard material or Carbide inserts also connected to the main body, in particular welded.

To further increase the security of the determination of Hard material or carbide inserts in the corresponding Receiving openings of the drill bit is according to a weiters preferred embodiment proposed that the holes or perforations of the drill head to a Outer surface of the drill head tapering cross-section and / or in from the outer surface of the drill head remote end region discontinued or with extended Cross section are formed. Such rejuvenating Recording openings can be correspondingly easy with correspondingly offset areas, which, for example, on increasing external dimensions the hard material or tungsten carbide inserts tuned can also be easily produced.

Fig. 1 einen Schnitt durch eine erste Ausführungsform einer erfindungsgemäßen Bohrkrone;

Fig. 2 eine Draufsicht auf die in Fig. 1 dargestellte Bohrkrone gemäß Pfeil II, wobei Fig. 1 einen Schnitt nach der Linie I-I der Fig. 2 darstellt;

Fig. 3 in einer zu Fig. 1 ähnlichen Darstellung einen Schnitt durch eine abgewandelte Ausführungsform einer erfindungsgemäßen Bohrkrone;

Fig. 4 eine Draufsicht auf die in Fig. 3 dargestellte Bohrkrone gemäß Pfeil IV, wobei Fig. 3 einen Schnitt nach der Linie III-III der Fig. 4 darstellt;

Fig. 5 wiederum in einer zu Fig. 1 ähnlichen Darstellung einen Schnitt durch eine weitere abgewandelte Ausführungsform einer erfindungsgemäßen Bohrkrone; und

Fig. 6 eine Draufsicht auf die in Fig. 5 dargestellte Bohrkrone gemäß Pfeil VI, wobei Fig. 5 einen Schnitt nach der Linie V-V der Fig. 6 darstellt.

The invention will be explained in more detail with reference to embodiments schematically illustrated in the accompanying drawings. In this show:

1 shows a section through a first embodiment of a drill bit according to the invention;

Fig. 2 is a plan view of the drill bit shown in Figure 1 according to arrow II, wherein Figure 1 is a section along the line II of Figure 2 ..;

FIG. 3 shows a section similar to FIG. 1 through a modified embodiment of a drill bit according to the invention; FIG.

FIG. 4 shows a plan view of the drill bit according to arrow IV shown in FIG. 3, whereby FIG. 3 shows a section along the line III-III of FIG. 4;

Fig. 5 in turn, in a similar to Figure 1 representation a section through a further modified embodiment of a drill bit according to the invention. and

Fig. 6 is a plan view of the drill bit shown in Fig. 5 according to arrow VI, wherein Fig. 5 shows a section along the line VV of Fig. 6.

In Fig. 1 and 2 is generally designated 1 a drill bit, wherein a base body 2, to which a not closer illustrated drill pipe, for example via a schematic indicated screw 3 connects, in one piece is formed with a drill head 4. The drill head 4 has a plurality of receiving openings 5, in each of which Hard material or carbide inserts 6 arranged are.

Furthermore, it can be seen from the plan view of FIG. 2, that in the drill head, for example, two flushing holes 7 for Introducing a flushing fluid in the range of degradation or Drilling surface open, with such a flushing fluid also introduced via the drill pipe not shown becomes.

The determination of hard material or carbide inserts 6 takes place in the embodiment shown in FIGS. 1 and 2 using sleeves 8 containing the hard material or hard metal inserts 6 over a partial area surrounded by their longitudinal extent, the sleeves 8 with the Material of the drill head 4 via schematically indicated Welds or welds 9 are welded.

Each hard material or hard metal insert 6 has on the facing away from the drill head projecting end, in the drill head 4 recorded end on an area 10, which a For example, spherical shaped surface 11 has. The receiving opening 5 is also with a corresponding curved or curved, complementary surface formed.

By providing the coordinated, curved or curved surface contours 11 of both hard material or carbide insert 6 and the receiving opening 5 can be ensured that, in particular, as the Stress of hard material or carbide inserts 6, which, for example, a relaxation in the individual receiving openings 5 can lead reliably even with a slight inclination in the respective Receiving opening 5 a corresponding power transmission from Base 2 or drill head 4 on the hard material or Carbide inserts 6 can be done.

The Hartmaterial- or carbide inserts 6 have hiebei in the end region 10 a stepped portion 13, wherein the end region 10 with respect to the projecting from the drill head 4 End of the hard material or cemented carbide insert 6 Has enlarged outer dimensions, so that through the Use of the sleeve 8 every Hartmaterial- or carbide insert securely held in the drill head 4. Because the Sleeve 8 usually from a compared to the Hartmaterial- or hard metal insert 6 softer or less solid Material is, can be particularly off-centered Stress of Hard Material or Carbide Inserts 6 expect a loosening of the same, but by the remote Area or the shoulder 13 falling out of the Hard material insert 6 from the receiving opening 5 avoided can be.

It was also found that after a relaxation of the Hard material or carbide inserts 6 in the mounting holes or openings 5 through the in a rotary impact drilling occurring, combined and alternating Schlagund Rotational stress also a rotational movement of hard material or hard metal inserts 6 in the respective mounting holes 5 takes place about its longitudinal axis, resulting in a self-sharpening effect of protruding from the drill head 4 Achieve tips or end portions of the hard material inserts 6 leaves.

In the illustrated in Figs. 3 and 4, modified Embodiment is again denoted by 2 main body is formed separately from the drill head 4 and it is Further, the drill head 4 divided into two halves, which in particular in Fig. 4 with 4 'and 4 "are designated.

Instead of using sleeves to fix the hard material inserts 6 in the drill head 4 become the hard material inserts 6 in the receiving openings 5 before a down of the drill head 4 on the base body 2 by insertion from the back or to the main body 2 facing side the drill head 4 is inserted into the respective receiving openings 5, whereupon subsequently the subregions 4 'and 4 "of the drill head are welded to the base body 2, with corresponding welds with 14 and 15 in Fig. 3rd are indicated.

As in the embodiment of FIGS. 1 and 2 show both the hard material or carbide inserts 6 as well the receiving openings 5 each complementary, domed or curved surfaces 11. Furthermore, one is again remote area or a shoulder 13 on the in the drill head 4 received end of each hard material or carbide insert 6 as a safeguard against falling out the respective receiving opening 5 of the drill head 4 is provided.

Also in the illustration shown in Figs. 5 and 6 finds a separate from the main body 2 of the drill bit 1 drill head 4 use, in which again before joining of the base body 2 with the drill head 4 hard material inserts 6 are received in corresponding receiving openings 5.

In contrast to the embodiment according to FIGS. 3 and 4 is in the embodiment shown in FIGS. 5 and 6 the drill head 4 integrally formed and it takes place a connection with the main body 2 by a turn with 14 indicated weld.

For proper power transmission even after a Loosening or wear of the hard material or carbide inserts 6 are also in this embodiment both recorded in the drill head 4 end of hard material or Carbide insert 6 as well as the receiving area in the Basic body 2 with a curved or curved surface educated.

Instead of training all Hartmaterialeinsätze 6 with a curved or curved surface could accordingly For example, the application only particularly stressed, individual hard material inserts 6 are formed be reliable to the required release energy to bring in the hole.

Claims (7)

1. A drill bit (1) for drilling and, in particular, rotary percussion drilling a hole and, in particular, a tap hole of a blast furnace, wherein the drill bit (1) is comprised of a drill head (4) including a plurality of hard-material or hard-metal inserts (6) and a base body (2) to be connected with a driving element or the like for actuating or powering the drill bit (1), said hard-material or hard-metal inserts (6) being received in bores or openings (5) of the drill head (4), wherein at least one hard-material or hard-metal insert (6), on its end received within the drill head (4), is at least partially designed with a curved or cambered surface contour (11) that cooperates with a complementary, cambered or curved surface of the drill head (4) and/or the base body (2), characterized in that the end (10) of the hard-material or hard-metal insert (6), which is designed with said cambered or curved surface contour (11) has external dimensions (13) larger than those of the end of the hard-material or hard-metal insert (6) projecting out of the drill head (4).
2. A drill bit according to claim 1, characterized in that the cambered surface contour (11) of the end (10) of the hard-material or hard-metal insert (6) is formed by a spherical surface or spherical layer.
3. A drill bit according to claim 1 or 2, characterized in that the clear width of a bore or opening (5) for receiving the hard-material or hard-metal insert (6) at least slightly exceeds the external dimensions of the end of the hard-material or hard-metal insert (6), to be received within the drill head (4), and that the hard-material or hard-metal insert (6) in its partial region received within the bore (5) is surrounded by a sleeve (8) whose external dimensions are adapted to the clear width of the bore (5) of the drill head (4).
4. A drill bit according to claim 3, characterized in that the sleeve (8) surrounding the hard-material or hard-metal insert (6) is weldable with the material of the drill head (4).
5. A drill bit according to any of the claims 1 to 4, characterized in that the hard-material or hard-metal inserts (6) are capable of being fitted into the bores or passage openings (5) from the drill head side facing the base body (2) of the drill bit (1), and that the drill head (4) is capable of being connected and, in particular, welded with the base body (2) upon reception of the hard-material or hard-metal inserts (6).
6. A drill bit according to claim 5, characterized in that the drill head (4) is dividedly designed, particularly on places or lines intended to each receive a plurality of hard-material or hard-metal inserts (6), and that the partial regions (4', 4") of the drill head (4) upon reception of the hard-material or hard-metal inserts (6) within the bores or openings (5) are capable of being connected and, in particular, welded with one another and/or with the base body (2).
7. A drill bit according to claim 5 or 6, characterized in that the bores or openings (5) of the drill head (4) have cross sections tapering towards the outer surface of the drill head (4) and/or are designed to be offset or have widening cross sections in the end regions facing away from the outer surface of the drill head (4).

Images