EP4006298B1 - Drilling device - Google Patents

Description

The invention relates to a drilling device with a drill rod and a drill bit, the drill bit being arranged at the end of the drilling device on the drilling side in the longitudinal direction and the drill bit having a middle part and folding wings which move about a folding wing pivot axis, which runs orthogonally to the longitudinal axis of the drilling device, along lateral contact surfaces of the middle part can be pivoted outwards and inwards, with the folding wings pivoting outwards in the working direction of rotation when the drilling device rotates, thereby increasing the end face of the drill bit.

Various drilling methods for rock and soil are known from the prior art. Such drillings are used, for example, in civil engineering, for setting anchors that introduce tensile forces into the ground or rock, and in geothermal energy. In these drilling methods, the drill bit is typically set in a rotating and often beating movement. A further distinction is made between cased and uncased bores. During cased drilling, the drill bit with the drill pipe (inner pipe) is brought to the target position through an outer pipe in order to drill the drilling material there. The drill pipe with the drill bit, which forms the drilling end of the drilling device and therefore comes into contact with the drilling material, protrudes from the outer tube.

On the one hand, the outer tube should not exceed a certain diameter to make it easier to insert the outer tube. On the other hand, it may be desirable to drill a hole with a diameter larger than the diameter of the outer tube. For this In this case, it is already known to use opening drill bits. The drill bit has folding wings that are moved outwards by the centrifugal forces when the drill bit is rotated in the working direction, so that the drill diameter increases. In this context, the working direction of rotation is understood to be the direction of rotation in which the drill bit or the drilling device rotate in order to achieve the desired drilling effect. Such a drill bit is, for example, from EP 2 927 417 A2 known.

An opening drill bit must be able to pivot about an axis orthogonal to the longitudinal axis of the drilling device, but on the other hand the drill bit should be as rigid as possible when pressed against the drilling material. In addition, it is desirable to have a drill bit in which the pivoting of the folding wings can be easily controlled, if possible without the application of flushing water, which requires a high pumping capacity.

Based on the prior art described above, the task is to provide a corresponding drilling device.

The object is achieved according to the invention by a drilling device with a drill pipe and a drill bit, the drill bit being arranged at the end of the drilling device on the drilling side in the longitudinal direction and the drill bit having a middle part and folding wings which are about a folding wing pivot axis, which runs orthogonally to the longitudinal axis of the drilling device, along lateral contact surfaces of the middle part can be pivoted outwards and inwards, with the folding wings pivoting outwards in the working direction of rotation when the drilling device rotates, which increases the end face of the drill bit, with the folding wings each having a foot part with an elongated hole through which a pin or a screw runs the folding wing pivot axis runs, so that the folding wings can be moved along the elongated holes between a drilling position in which the end faces of the folding wings form a common plane with other frontal areas of the drill bit, and a pivoting position in which the folding wings protrude axially over the middle part and outwards can be pivoted on the inside, with the foot parts of the folding wings in the drilling position engaging positively in corresponding receptacles in the drill bit, the drill bit having a beveled surface for each folding wing pointing in the direction of the respective foot part The direction of the drilling-side end of the drilling device extends radially outwards, and the folding wings can be brought into an inwardly pivoted position by rotating the drilling device against the working direction of rotation, in which the beveled surfaces each form a stop for the foot parts of the folding wings.

The drilling device according to the invention has a drill pipe, also called inner pipe, at one end of which the drill bit is located. The drill pipe thus forms the drill bit carrier. When drilling, the drill bit points in the direction of the material to be drilled and is designed in such a way that it produces a drilling effect through rotational and/or impact movements. The drill bit has an end face facing the drilling material, which runs essentially perpendicular to the longitudinal axis of the drilling device, the drilling device longitudinal axis being understood to be the longitudinal axis which runs through the entire drill pipe. However, the drill bit can have lateral bevels, which also produce a drilling effect.

The drill bit has a base body with a non-pivoting middle part and folding wings that can be pivoted outwards and inwards about a folding wing pivot axis, with the folding wing pivot axis running perpendicular to the longitudinal axis of the drilling device. Both the middle part and the folding wings have end faces that face the material to be drilled when drilling, which create a drilling effect. When the folding wings are pivoted outwards, the folding wings increase the end face available for drilling, with the total diameter of the drill bit in this state normally exceeding the diameter of the outer tube. Accordingly, the drilling diameter is larger than the outside diameter of the piping. The outward pivoting occurs automatically due to the acting centrifugal forces when the drilling device is rotated in the working direction. As a rule, the drill bit has two folding wings, which rest pivotably on opposite sides of the middle part and, in the drilling position, are pivoted outwards in the opposite direction relative to the longitudinal axis of the drilling device. However, drilling devices with more than two folding wings are also conceivable, especially in the case of larger drill bits.

In order to insert the drilling device into the outer tube or, after completion of the drilling, to pull it back into the outer tube, the folding wings are pivoted inwards, whereby the overall cross section of the drill bit decreases to such an extent that its diameter is smaller than the inner diameter of the outer tube. This inward pivoting can be done manually from the outside, but it can also be brought about by rotating the drilling device against the working direction of rotation.

The folding wings each have a foot part, which can be inserted positively into a corresponding holder in the drill bit. The foot part and receptacle each have an extension in the longitudinal direction corresponding to the longitudinal axis of the drilling device, i.e. by exerting a force on the end face of the drill bit, the foot parts are pressed into the corresponding receptacles. This happens due to the counter pressure exerted by the drilling material or the surface on which the drill bit is placed. The base parts of the folding wings are usually narrower than the areas of the folding wings that are further away from the drilling side. The receptacles for the foot parts are correspondingly narrow, so that the foot parts can be accommodated in the receptacles in a form-fitting manner. The term “narrow” in this context refers to the extent orthogonal to the longitudinal direction of the drilling device. The foot parts can also be arranged radially offset from the areas of the folding wings located further on the drilling side.

When the foot parts are fully inserted into the receptacles, the end faces of the folding wings form a common end face for drilling with the end faces of the middle part. In this position, the folding wings are fixed with regard to pivoting inwards or outwards, ie the drill bit forms a rigid unit as a whole that can withstand the mechanical loads during drilling. To make it possible to move the folding wings in the longitudinal direction, the foot parts each have an elongated hole through which a pin runs, which connects the folding wing to the middle part. The head of the pin must have a diameter that prevents it from slipping out of the slot. The term pin is interpreted broadly in this context; a bolt or a screw is also considered a pin in the sense of the invention, that is, in particular, a screw can also be used. As an equivalent to providing an elongated hole in the foot part, one is also used Reverse design is considered, in which the drill bit for each folding wing has an elongated hole into which a pin/screw extending from the foot part can engage.

After the drilling process has been completed, the drill pipe is raised so that the foot parts of the folding wings slip out of the holders and the folding wings move into the swivel position.

Another important feature of the drilling device according to the invention are the beveled surfaces in the drill bit, which serve as a stop for the foot part of the respective folding wing when the folding wing is pivoted inwards. The beveled surfaces can also be referred to as angular bevels. A beveled surface in the sense of the invention is also a slightly rounded surface, which also fulfills the function of the beveled surface described. Such a beveled surface is provided for each folding wing. This beveled surface points in the direction of a longitudinal edge of the respective foot part when the foot part does not engage in the corresponding receptacle, in other words the folding wing is in the pivoting position in which pivoting outwards or inwards is possible. The beveled surface is designed such that the recess created by it widens in the direction of the drilling end, ie the beveled surface extends radially outwards in the direction of the drilling end of the drilling device. In the opposite direction, ie at the end facing away from the drilling side, the beveled surface merges into the receptacle for the foot part of the folding sash, so that the foot part of the folding sash can slide along the beveled surface into the receptacle. Viewed in the longitudinal section of the drilling device, the beveled surface, which is intended to limit the inwardly pivoted position of the respective folding wing, is normally one-sided, that is, it extends on one side from the drilling-side end of the receptacle over a certain distance further towards the drilling-side end of the drilling device radially outwards. In this way, the beveled surface on one side forms a stop for the folding wing when it is pivoted inwards, and also allows the foot part of the folding wing to slide along the beveled surface into the receptacle when the drill head is brought into the drilling position.

If the drilling device is rotated in the opposite direction to the working direction, the folding wings pivot inwards. The beveled surfaces form a stop for the foot parts of the folding sashes, thus limiting the pivoting movement of the folding sashes. In this way it is also ensured that the overall diameter of the drilling device after the folding wings have been pivoted inwards is such that it can be inserted or withdrawn into the outer tube. To insert it into the outer tube, the drilling device is rotated as described and then guided into the outer tube by lowering the drill pipe.

Even if the folding wings are not completely pivoted inwards by rotating against the working direction of rotation, the beveled surfaces help to pull the drilling device back into the outer tube, namely as a threading bevel. The folding wings thus touch the edge of the outer tube when retracted and are folded inwards until they abut the beveled surfaces, so that they overall assume a position in which retraction into the outer tube is possible.

Another function of the beveled surfaces is the function of centering, i.e. H. The beveled surfaces ensure that the foot parts of the folding sashes slide into the receptacles provided in drilling mode and assume the fixed position described above.

The folding wings of the drill bit can be easily controlled in the pivoting position mechanically or by setting them in a rotational movement in or against the working direction of rotation. The use of flushing fluid to control the drill bit is not necessary. Accordingly, no energy has to be invested in additional pumping power to control the drill bit.

Overall, in the front plan view of the drilling or end face, the drill bit typically has a substantially circular shape, from which individual areas protrude in order to bring about a sufficient drilling effect via the rotary movement. The protruding areas can in particular be parts of the folding wings. Apart from the protruding areas, they fit together However, folding wings fit into the basic shape of the drill bit, ie the free spaces on the side of the middle part are filled by the folding wings. In other words, the drill bit has recesses on the front side, between which the middle part is located, the recesses being completely or completely filled by the folding wings. When viewed from above, the folding wings themselves preferably form a segment of a circle or part of a segment of a circle. The end face of the drill bit can have a beveled edge.

As a rule, the drilling device according to the invention has two folding wings. These are located on both sides of the middle part in recesses provided for this purpose in the drill bit. The middle part therefore has two lateral, normally parallel contact surfaces over which the folding wings can slide past inwards and outwards. Both when pivoting outwards and inwards, the folding wings move in the opposite direction, so that the protruding areas of the folding wings protrude in the opposite direction over the circular base of the drill bit after pivoting outwards into the drilling position.

In the inwardly pivoted position, which is intended to insert or retract the drilling device into the outer tube, the folding wings should not protrude radially beyond the other areas of the drill bit or only protrude so insignificantly that the insertion/retraction into the outer tube is not hindered becomes.

In order to achieve a sufficient drilling effect, especially when the drive is impacting, the drill bit can have cutting elements on the front side which protrude beyond the other end face of the drill bit. Such cutting elements are in particular hard metal objects, for example hard metal balls, hard metal plates or hard metal pins, which can be embedded in the drill bit. Hard metals are metal matrix composite materials in which hard materials such as tungsten carbide are embedded in a metal matrix. If the end face of the drill bit has a beveled edge, this should also be provided with appropriate cutting elements.

The drill pipe is typically coupled or can be coupled to a drive shaft. In particular, the drill pipe can have coupling pieces at its end facing away from the drilling side, via which it can be coupled to a drive for the drilling device.

The drive can be a rotating and/or beating drive. A rotating and beating drive is preferred. In particular, the drilling device can be driven via a hydraulic hammer or down-the-hole hammer. The drilling device can be used in various known drilling processes, for example in ram drilling processes, auger drilling processes, double-head drilling processes or overburden drilling processes.

The drilling device according to the invention can be used in drilling processes with or without mud. In the case of drilling methods with flushing, flushing channels are provided in the drill bit, through which flushing fluid is brought to the end face of the drill bit. In this context, the rinsing liquid usually has different functions. On the one hand, it is used to remove the drill cuttings, and on the other hand, the drill bit is cooled in this way. Another task of the flushing fluid is to clean the seat of the folding sashes and to ensure that the folding or pivoting mechanism functions properly. In order to achieve the latter, it makes sense to provide holes for the flushing channels in the area of the holder for the foot parts of the folding wings, so that the fixation of the folding wings for the drilling position is not hindered by contamination.

Furthermore, the invention also relates to a combination of a drilling device as described above and an outer tube through which the drilling device is brought to the drilling position, the drill bit protruding beyond the outer tube in the drilling position.

The invention is explained in more detail using the figures as an example. It should be noted that the figures show preferred embodiment variants of the invention, but the invention is not limited to this. In particular, the invention includes, as far as it makes technical sense, any combinations of technical features that are listed in the claims or described in the description as relevant to the invention.

Fig. 1

die erfindungsgemäße Bohrvorrichtung in der Seitenansicht ohne Klappflügel;

Fig. 2

einen Klappflügel in der Seitenansicht;

Fig. 3

die erfindungsgemäße Bohrvorrichtung in der Seitenansicht mit eingeklappten Klappflügeln;

Fig. 4

eine Draufsicht auf die Stirnseite der Bohrkrone mit eingeklappten Klappflügeln;

Fig. 5

die erfindungsgemäße Bohrvorrichtung in der Seitenansicht mit ausgeklappten Klappflügeln;

Fig. 6

eine Draufsicht auf die Stirnseite der Bohrkrone mit ausgeklappten Klappflügeln;

Fig. 7

die erfindungsgemäße Bohrvorrichtung in der Seitenansicht im Außenrohr mit eingeklappten Klappflügeln und

Fig. 8

die erfindungsgemäße Bohrvorrichtung in der Seitenansicht im Außenrohr mit ausgeklappten Klappflügeln.

Show it:

Fig. 1

The drilling device according to the invention in a side view without folding wings;

Fig. 2

a folding wing in side view;

Fig. 3

The drilling device according to the invention in a side view with the folding wings folded in;

Fig. 4

a top view of the face of the drill bit with the folding wings folded in;

Fig. 5

The drilling device according to the invention in a side view with the folding wings folded out;

Fig. 6

a top view of the front side of the drill bit with the folding wings unfolded;

Fig. 7

The drilling device according to the invention in a side view in the outer tube with the folding wings folded in and

Fig. 8

The drilling device according to the invention in a side view in the outer tube with unfolded folding wings.

In Fig. 1 the drilling device 1 according to the invention is shown in a side view, but only the base body, ie without folding wings. The drilling device has a drill pipe 2 and a drill bit 3 at the drilling end 13, ie the end that comes into contact with the drilling material. The drill bit 3 has various cutting elements 14 on its end face 7, which are in particular hard metal objects.

The base body has indented lateral contact surfaces 6 on both sides of the drill bit 3 at the drilling end, on which they are not present here shown folding wing 5 can slide along when pivoting outwards or inwards. In addition, a receptacle 11 for the foot part 8 of the folding wing 5 is provided on both sides. In the drilling position, the foot part 8 can engage in the receptacle 11 so that the folding wing 5 is fixed. A pin 10 engages in the pin receptacle 17, via which the folding wing 5 is fastened to the base body by means of its elongated hole 9, so that the folding wing 5 can be moved and pivoted about the pin 10. A screw can also be used as the pin 10, which otherwise fulfills the same function. Furthermore, a flushing channel 15 is provided in the area of the receptacle 11, through which flushing liquid can emerge and clean the mechanics of the drill bit 3.

Another feature that is significant according to the invention is the beveled surface 12, which serves as a stop when the folding wing 5 is folded inwards. In addition, the beveled surface 12 also serves to allow the foot part 8 of the folding wing 5 to slide into the receptacle 11 provided for it when the drill bit 3 is transferred into the drilling position by the frontal pressure of the drilling material. Finally, the beveled surface 12 also serves as a threading bevel when the folding wings 5 have to be folded to such an extent that they can be pulled back into the outer tube.

In Fig. 2 a folding wing 5 is shown. Like the non-pivoting areas 4 of the drill bit 3, this has cutting elements 14 on the front side. At the end opposite the end face, the drill bit 3 has a significantly narrower foot part 8 with an elongated hole 9. Via this elongated hole 9, the folding wing 5 is attached to the drill bit 3 by means of a pin 10 in such a way that, on the one hand, the folding wing 5 can be pivoted about the pin 10 and, on the other hand, the elongated hole 9 can be moved around the pin 10.

Fig. 3 shows the drilling device 1 according to the invention in a side view with folded folding wings 5. A folding wing 5 is now attached to both sides of the drill bit 3. The folding wings 5 are in the pivoting position, ie the folding wings 5 can be folded or pivoted around the pin 10 outwards or inwards. When pivoting inwards, the beveled surface 12, which is hidden here, serves as a stop. In the pivoting position, the folding wings 5 do not protrude laterally beyond the other areas of the drill bit 3, which is why insertion or retraction occurs in this position into an outer pipe is possible without any problems. When the folding wings 5 are pivoted, they slide past the side contact surfaces 6 of the middle part 4 of the drill bit 3. In the longitudinal direction, however, the folding wings 5 protrude significantly beyond the adjacent areas of the drill bit 3.

The situation Fig. 3 is in Fig. 4 shown in the front top view. The folding wings 5 do not protrude beyond the circumference of the drill bit 3, rather the drill bit 3 has a circular cross-section overall in this position. The drill bit 3 has a middle part 4 that cannot be folded or pivoted. On the side of it, the drill bit has 3 recesses in which the folding wings 5 come to rest. The folding wings 5 can be pivoted along the side contact surfaces 6 of the middle part 4.

Both the middle part 4 and the folding wings 5 have a large number of cutting elements 14 made of hard metal on the front, with which a sufficient drilling effect can be achieved even in rock or the like. Finally, mouths of the rinsing channels 15 are provided on the front side of the drill bit 3, through which rinsing liquid can be brought to the front side 7 to remove the cuttings and to cool the drill bit 3.

In Fig. 5 the drilling device 1 according to the invention is shown in a side view with the folding wings 5 folded out. This is the drilling position, in which the foot parts 8 of the folding wings 5 are retracted into the corresponding receptacles 11 and are therefore fixed laterally. The foot parts 8 are inserted into the receptacles 11 by moving the pin 10 against each other relative to the elongated hole 9. The end faces of the folding wings 5 and the end faces of the non-pivoting middle part 4 of the drill bit 3 form a common plane on which there are a large number of cutting elements 14 recognizes. Since the folding wings 5 protrude radially, the end face 7 is correspondingly enlarged during drilling and a borehole with a larger diameter is obtained.

The situation Fig. 5 is in Fig. 6 shown in the front top view. The folding wings 5 now protrude significantly beyond the circumference of the drill bit 3 and can bring about a cutting effect with their protruding edges. Otherwise the representation corresponds to that from Fig. 4 .

In Fig. 7 is the drilling device 1 with folded folding wings 5 accordingly Fig. 3 shown in the outer tube 16. By folding the folding wings 5, the overall diameter is such that insertion into and through the outer tube 16 is possible without any problems.

Fig. 8 shows the drilling device 1 Fig. 7 , whereby the drill bit 3 was partially pushed out of the outer tube 16 towards the drilling side. By pressing on the material to be drilled or the drilling surface, the foot parts 8 of the folding wings 5 slide into the receptacles 11, ie the folding wings 5 reach the drilling position. In this position, the folding wings 5 protrude laterally over the remaining areas of the drill bit 3 and also over the outer tube 16. In order to be able to pull the drill bit 3 back into the outer tube 16 after the drilling process has ended, the folding wings 5 must first be folded in, which reduces the diameter. This happens, for example, by rotating the drilling device 1 counter to the working direction of rotation.

Claims (11)

1. Drilling device having a drill rod (2) and a drill bit (3), wherein the drill bit (3) is arranged at the end of the drilling device (1) that is on the drilling side in the longitudinal direction and the drill bit (3) has a middle portion (4) and folding wings (5) which are pivotable outwards and inwards along lateral contact faces (6) of the middle portion (4) about a folding wing pivot axis which runs orthogonal to the drilling device longitudinal axis, wherein the folding wings (5) pivot outwards when the drilling device (1) rotates in the working rotational direction, whereby the end face (7) of the drill bit (3) becomes larger,
   characterised in that
   the folding wings (5) each have a foot portion (8) having an elongate hole (9) through which a pin or a screw (10) runs along the folding wing pivot axis, so that the folding wings (5) are displaceable along the elongate holes (9) between a drilling position, in which the end faces of the folding wings (5) form a common plane with further end regions of the drill bit (3), and a pivot position, in which the folding wings (5) project axially beyond the middle portion (4) and are pivotable outwards and inwards, wherein in the drilling position the foot portions (8) of the folding wings (5) engage in an interlocking manner into corresponding receivers (11) in the drill bit (3), wherein the drill bit (3) has for each folding wing (5) a bevelled surface (12) which faces in the direction of the respective foot portion (8) and which runs radially outwards in the direction of the drilling-side end of the drilling device (1), and wherein, by rotation of the drilling device (1) contrary to the working rotational direction, the folding wings (5) can be brought into an inwardly pivot position in which the bevelled surfaces (12) each form a stop for the foot portions (8) of the folding wings (5).
2. Drilling device according to claim 1, characterised in that the drilling device (1) has two folding wings (5).
3. Drilling device according to claim 1 or 2, characterised in that the folding wings (5) do not project radially beyond the further regions of the drill bit (3) in the inwardly pivot position.
4. Drilling device according to any one of claims 1 to 3, characterised in that the drill bit (3) has projecting cutting elements (14) on its end face.
5. Drilling device according to claim 4, characterised in that the cutting elements (14) are carbide objects, in particular carbide pins.
6. Drilling device according to any one of claims 1 to 5, characterised in that the drill rod (2) is coupled or couplable with a drive shaft by way of coupling elements.
7. Drilling device according to claim 6, characterised in that the drive is a rotating and/or percussive drive.
8. Drilling device according to any one of claims 1 to 7, characterised in that the drilling device (1) is driven by way of a hydraulic hammer or down-the-hole hammer.
9. Drilling device according to any one of claims 1 to 8, characterised by flushing channels (15) in the drill bit (3), through which flushing channels flushing liquid can be supplied to the end face of the drill bit (3).
10. Drilling device according to claim 9, characterised by bores for the flushing channels (15) in the region of the receivers (11) for the foot portions (8) of the folding wings (5).
11. Combination of a drilling device (1) according to any one of claims 1 to 10 and an outer tube (16) through which the drilling device (1) is brought to the drilling position, wherein the drill bit (3) projects beyond the outer tube (16) in the drilling position.

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